Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

23 files changed, 23640 insertions, 0 deletions

diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig
new file mode 100644
index 000000000..9ac7574e3
--- /dev/null
+++ b/drivers/s390/block/Kconfig
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0
+comment "S/390 block device drivers"
+	depends on S390 && BLOCK
+
+config BLK_DEV_XPRAM
+	def_tristate m
+	prompt "XPRAM disk support"
+	depends on S390 && BLOCK
+	help
+	  Select this option if you want to use your expanded storage on S/390
+	  or zSeries as a disk.  This is useful as a _fast_ swap device if you
+	  want to access more than 2G of memory when running in 31 bit mode.
+	  This option is also available as a module which will be called
+	  xpram.  If unsure, say "N".
+
+config DCSSBLK
+	def_tristate m
+	select FS_DAX_LIMITED
+	select DAX_DRIVER
+	prompt "DCSSBLK support"
+	depends on S390 && BLOCK
+	help
+	  Support for dcss block device
+
+config DASD
+	def_tristate y
+	prompt "Support for DASD devices"
+	depends on CCW && BLOCK
+	select IOSCHED_DEADLINE
+	help
+	  Enable this option if you want to access DASDs directly utilizing
+	  S/390s channel subsystem commands. This is necessary for running
+	  natively on a single image or an LPAR.
+
+config DASD_PROFILE
+	def_bool y
+	prompt "Profiling support for dasd devices"
+	depends on DASD
+	help
+	  Enable this option if you want to see profiling information
+          in /proc/dasd/statistics.
+
+config DASD_ECKD
+	def_tristate y
+	prompt "Support for ECKD Disks"
+	depends on DASD
+	help
+	  ECKD devices are the most commonly used devices. You should enable
+	  this option unless you are very sure to have no ECKD device.
+
+config DASD_FBA
+	def_tristate y
+	prompt "Support for FBA  Disks"
+	depends on DASD
+	help
+	  Select this option to be able to access FBA devices. It is safe to
+	  say "Y".
+
+config DASD_DIAG
+	def_tristate y
+	prompt "Support for DIAG access to Disks"
+	depends on DASD
+	help
+	  Select this option if you want to use Diagnose250 command to access
+	  Disks under VM.  If you are not running under VM or unsure what it is,
+	  say "N".
+
+config DASD_EER
+	def_bool y
+	prompt "Extended error reporting (EER)"
+	depends on DASD
+	help
+	  This driver provides a character device interface to the
+	  DASD extended error reporting. This is only needed if you want to
+	  use applications written for the EER facility.
+
+config SCM_BLOCK
+	def_tristate m
+	prompt "Support for Storage Class Memory"
+	depends on S390 && BLOCK && EADM_SCH && SCM_BUS
+	help
+	  Block device driver for Storage Class Memory (SCM). This driver
+	  provides a block device interface for each available SCM increment.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called scm_block.
diff --git a/drivers/s390/block/Makefile b/drivers/s390/block/Makefile
new file mode 100644
index 000000000..60c85cff5
--- /dev/null
+++ b/drivers/s390/block/Makefile
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# S/390 block devices
+#
+
+dasd_eckd_mod-objs := dasd_eckd.o dasd_3990_erp.o dasd_alias.o
+dasd_fba_mod-objs  := dasd_fba.o
+dasd_diag_mod-objs := dasd_diag.o
+dasd_mod-objs      := dasd.o dasd_ioctl.o dasd_proc.o dasd_devmap.o \
+			dasd_genhd.o dasd_erp.o
+ifdef CONFIG_DASD_EER
+dasd_mod-objs      += dasd_eer.o
+endif
+
+obj-$(CONFIG_DASD) += dasd_mod.o
+obj-$(CONFIG_DASD_DIAG) += dasd_diag_mod.o
+obj-$(CONFIG_DASD_ECKD) += dasd_eckd_mod.o
+obj-$(CONFIG_DASD_FBA)  += dasd_fba_mod.o
+obj-$(CONFIG_BLK_DEV_XPRAM) += xpram.o
+obj-$(CONFIG_DCSSBLK) += dcssblk.o
+
+scm_block-objs := scm_drv.o scm_blk.o
+obj-$(CONFIG_SCM_BLOCK) += scm_block.o
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
new file mode 100644
index 000000000..7beda20cf
--- /dev/null
+++ b/drivers/s390/block/dasd.c
@@ -0,0 +1,4149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ */
+
+#define KMSG_COMPONENT "dasd"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ctype.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/hdreg.h>
+#include <linux/async.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+
+#include <asm/ccwdev.h>
+#include <asm/ebcdic.h>
+#include <asm/idals.h>
+#include <asm/itcw.h>
+#include <asm/diag.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd:"
+
+#include "dasd_int.h"
+/*
+ * SECTION: Constant definitions to be used within this file
+ */
+#define DASD_CHANQ_MAX_SIZE 4
+
+#define DASD_DIAG_MOD		"dasd_diag_mod"
+
+static unsigned int queue_depth = 32;
+static unsigned int nr_hw_queues = 4;
+
+module_param(queue_depth, uint, 0444);
+MODULE_PARM_DESC(queue_depth, "Default queue depth for new DASD devices");
+
+module_param(nr_hw_queues, uint, 0444);
+MODULE_PARM_DESC(nr_hw_queues, "Default number of hardware queues for new DASD devices");
+
+/*
+ * SECTION: exported variables of dasd.c
+ */
+debug_info_t *dasd_debug_area;
+EXPORT_SYMBOL(dasd_debug_area);
+static struct dentry *dasd_debugfs_root_entry;
+struct dasd_discipline *dasd_diag_discipline_pointer;
+EXPORT_SYMBOL(dasd_diag_discipline_pointer);
+void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
+
+MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
+MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
+		   " Copyright IBM Corp. 2000");
+MODULE_SUPPORTED_DEVICE("dasd");
+MODULE_LICENSE("GPL");
+
+/*
+ * SECTION: prototypes for static functions of dasd.c
+ */
+static int  dasd_alloc_queue(struct dasd_block *);
+static void dasd_setup_queue(struct dasd_block *);
+static void dasd_free_queue(struct dasd_block *);
+static int dasd_flush_block_queue(struct dasd_block *);
+static void dasd_device_tasklet(unsigned long);
+static void dasd_block_tasklet(unsigned long);
+static void do_kick_device(struct work_struct *);
+static void do_restore_device(struct work_struct *);
+static void do_reload_device(struct work_struct *);
+static void do_requeue_requests(struct work_struct *);
+static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
+static void dasd_device_timeout(struct timer_list *);
+static void dasd_block_timeout(struct timer_list *);
+static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
+static void dasd_profile_init(struct dasd_profile *, struct dentry *);
+static void dasd_profile_exit(struct dasd_profile *);
+static void dasd_hosts_init(struct dentry *, struct dasd_device *);
+static void dasd_hosts_exit(struct dasd_device *);
+
+/*
+ * SECTION: Operations on the device structure.
+ */
+static wait_queue_head_t dasd_init_waitq;
+static wait_queue_head_t dasd_flush_wq;
+static wait_queue_head_t generic_waitq;
+static wait_queue_head_t shutdown_waitq;
+
+/*
+ * Allocate memory for a new device structure.
+ */
+struct dasd_device *dasd_alloc_device(void)
+{
+	struct dasd_device *device;
+
+	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
+	if (!device)
+		return ERR_PTR(-ENOMEM);
+
+	/* Get two pages for normal block device operations. */
+	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
+	if (!device->ccw_mem) {
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+	/* Get one page for error recovery. */
+	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
+	if (!device->erp_mem) {
+		free_pages((unsigned long) device->ccw_mem, 1);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
+	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
+	spin_lock_init(&device->mem_lock);
+	atomic_set(&device->tasklet_scheduled, 0);
+	tasklet_init(&device->tasklet, dasd_device_tasklet,
+		     (unsigned long) device);
+	INIT_LIST_HEAD(&device->ccw_queue);
+	timer_setup(&device->timer, dasd_device_timeout, 0);
+	INIT_WORK(&device->kick_work, do_kick_device);
+	INIT_WORK(&device->restore_device, do_restore_device);
+	INIT_WORK(&device->reload_device, do_reload_device);
+	INIT_WORK(&device->requeue_requests, do_requeue_requests);
+	device->state = DASD_STATE_NEW;
+	device->target = DASD_STATE_NEW;
+	mutex_init(&device->state_mutex);
+	spin_lock_init(&device->profile.lock);
+	return device;
+}
+
+/*
+ * Free memory of a device structure.
+ */
+void dasd_free_device(struct dasd_device *device)
+{
+	kfree(device->private);
+	free_page((unsigned long) device->erp_mem);
+	free_pages((unsigned long) device->ccw_mem, 1);
+	kfree(device);
+}
+
+/*
+ * Allocate memory for a new device structure.
+ */
+struct dasd_block *dasd_alloc_block(void)
+{
+	struct dasd_block *block;
+
+	block = kzalloc(sizeof(*block), GFP_ATOMIC);
+	if (!block)
+		return ERR_PTR(-ENOMEM);
+	/* open_count = 0 means device online but not in use */
+	atomic_set(&block->open_count, -1);
+
+	atomic_set(&block->tasklet_scheduled, 0);
+	tasklet_init(&block->tasklet, dasd_block_tasklet,
+		     (unsigned long) block);
+	INIT_LIST_HEAD(&block->ccw_queue);
+	spin_lock_init(&block->queue_lock);
+	timer_setup(&block->timer, dasd_block_timeout, 0);
+	spin_lock_init(&block->profile.lock);
+
+	return block;
+}
+EXPORT_SYMBOL_GPL(dasd_alloc_block);
+
+/*
+ * Free memory of a device structure.
+ */
+void dasd_free_block(struct dasd_block *block)
+{
+	kfree(block);
+}
+EXPORT_SYMBOL_GPL(dasd_free_block);
+
+/*
+ * Make a new device known to the system.
+ */
+static int dasd_state_new_to_known(struct dasd_device *device)
+{
+	int rc;
+
+	/*
+	 * As long as the device is not in state DASD_STATE_NEW we want to
+	 * keep the reference count > 0.
+	 */
+	dasd_get_device(device);
+
+	if (device->block) {
+		rc = dasd_alloc_queue(device->block);
+		if (rc) {
+			dasd_put_device(device);
+			return rc;
+		}
+	}
+	device->state = DASD_STATE_KNOWN;
+	return 0;
+}
+
+/*
+ * Let the system forget about a device.
+ */
+static int dasd_state_known_to_new(struct dasd_device *device)
+{
+	/* Disable extended error reporting for this device. */
+	dasd_eer_disable(device);
+	device->state = DASD_STATE_NEW;
+
+	if (device->block)
+		dasd_free_queue(device->block);
+
+	/* Give up reference we took in dasd_state_new_to_known. */
+	dasd_put_device(device);
+	return 0;
+}
+
+static struct dentry *dasd_debugfs_setup(const char *name,
+					 struct dentry *base_dentry)
+{
+	struct dentry *pde;
+
+	if (!base_dentry)
+		return NULL;
+	pde = debugfs_create_dir(name, base_dentry);
+	if (!pde || IS_ERR(pde))
+		return NULL;
+	return pde;
+}
+
+/*
+ * Request the irq line for the device.
+ */
+static int dasd_state_known_to_basic(struct dasd_device *device)
+{
+	struct dasd_block *block = device->block;
+	int rc = 0;
+
+	/* Allocate and register gendisk structure. */
+	if (block) {
+		rc = dasd_gendisk_alloc(block);
+		if (rc)
+			return rc;
+		block->debugfs_dentry =
+			dasd_debugfs_setup(block->gdp->disk_name,
+					   dasd_debugfs_root_entry);
+		dasd_profile_init(&block->profile, block->debugfs_dentry);
+		if (dasd_global_profile_level == DASD_PROFILE_ON)
+			dasd_profile_on(&device->block->profile);
+	}
+	device->debugfs_dentry =
+		dasd_debugfs_setup(dev_name(&device->cdev->dev),
+				   dasd_debugfs_root_entry);
+	dasd_profile_init(&device->profile, device->debugfs_dentry);
+	dasd_hosts_init(device->debugfs_dentry, device);
+
+	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
+	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
+					    8 * sizeof(long));
+	debug_register_view(device->debug_area, &debug_sprintf_view);
+	debug_set_level(device->debug_area, DBF_WARNING);
+	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
+
+	device->state = DASD_STATE_BASIC;
+
+	return rc;
+}
+
+/*
+ * Release the irq line for the device. Terminate any running i/o.
+ */
+static int dasd_state_basic_to_known(struct dasd_device *device)
+{
+	int rc;
+
+	if (device->discipline->basic_to_known) {
+		rc = device->discipline->basic_to_known(device);
+		if (rc)
+			return rc;
+	}
+
+	if (device->block) {
+		dasd_profile_exit(&device->block->profile);
+		debugfs_remove(device->block->debugfs_dentry);
+		dasd_gendisk_free(device->block);
+		dasd_block_clear_timer(device->block);
+	}
+	rc = dasd_flush_device_queue(device);
+	if (rc)
+		return rc;
+	dasd_device_clear_timer(device);
+	dasd_profile_exit(&device->profile);
+	dasd_hosts_exit(device);
+	debugfs_remove(device->debugfs_dentry);
+	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
+	if (device->debug_area != NULL) {
+		debug_unregister(device->debug_area);
+		device->debug_area = NULL;
+	}
+	device->state = DASD_STATE_KNOWN;
+	return 0;
+}
+
+/*
+ * Do the initial analysis. The do_analysis function may return
+ * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
+ * until the discipline decides to continue the startup sequence
+ * by calling the function dasd_change_state. The eckd disciplines
+ * uses this to start a ccw that detects the format. The completion
+ * interrupt for this detection ccw uses the kernel event daemon to
+ * trigger the call to dasd_change_state. All this is done in the
+ * discipline code, see dasd_eckd.c.
+ * After the analysis ccw is done (do_analysis returned 0) the block
+ * device is setup.
+ * In case the analysis returns an error, the device setup is stopped
+ * (a fake disk was already added to allow formatting).
+ */
+static int dasd_state_basic_to_ready(struct dasd_device *device)
+{
+	int rc;
+	struct dasd_block *block;
+	struct gendisk *disk;
+
+	rc = 0;
+	block = device->block;
+	/* make disk known with correct capacity */
+	if (block) {
+		if (block->base->discipline->do_analysis != NULL)
+			rc = block->base->discipline->do_analysis(block);
+		if (rc) {
+			if (rc != -EAGAIN) {
+				device->state = DASD_STATE_UNFMT;
+				disk = device->block->gdp;
+				kobject_uevent(&disk_to_dev(disk)->kobj,
+					       KOBJ_CHANGE);
+				goto out;
+			}
+			return rc;
+		}
+		dasd_setup_queue(block);
+		set_capacity(block->gdp,
+			     block->blocks << block->s2b_shift);
+		device->state = DASD_STATE_READY;
+		rc = dasd_scan_partitions(block);
+		if (rc) {
+			device->state = DASD_STATE_BASIC;
+			return rc;
+		}
+	} else {
+		device->state = DASD_STATE_READY;
+	}
+out:
+	if (device->discipline->basic_to_ready)
+		rc = device->discipline->basic_to_ready(device);
+	return rc;
+}
+
+static inline
+int _wait_for_empty_queues(struct dasd_device *device)
+{
+	if (device->block)
+		return list_empty(&device->ccw_queue) &&
+			list_empty(&device->block->ccw_queue);
+	else
+		return list_empty(&device->ccw_queue);
+}
+
+/*
+ * Remove device from block device layer. Destroy dirty buffers.
+ * Forget format information. Check if the target level is basic
+ * and if it is create fake disk for formatting.
+ */
+static int dasd_state_ready_to_basic(struct dasd_device *device)
+{
+	int rc;
+
+	device->state = DASD_STATE_BASIC;
+	if (device->block) {
+		struct dasd_block *block = device->block;
+		rc = dasd_flush_block_queue(block);
+		if (rc) {
+			device->state = DASD_STATE_READY;
+			return rc;
+		}
+		dasd_destroy_partitions(block);
+		block->blocks = 0;
+		block->bp_block = 0;
+		block->s2b_shift = 0;
+	}
+	return 0;
+}
+
+/*
+ * Back to basic.
+ */
+static int dasd_state_unfmt_to_basic(struct dasd_device *device)
+{
+	device->state = DASD_STATE_BASIC;
+	return 0;
+}
+
+/*
+ * Make the device online and schedule the bottom half to start
+ * the requeueing of requests from the linux request queue to the
+ * ccw queue.
+ */
+static int
+dasd_state_ready_to_online(struct dasd_device * device)
+{
+	struct gendisk *disk;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+
+	device->state = DASD_STATE_ONLINE;
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if ((device->features & DASD_FEATURE_USERAW)) {
+			disk = device->block->gdp;
+			kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+			return 0;
+		}
+		disk = device->block->bdev->bd_disk;
+		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+		while ((part = disk_part_iter_next(&piter)))
+			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+		disk_part_iter_exit(&piter);
+	}
+	return 0;
+}
+
+/*
+ * Stop the requeueing of requests again.
+ */
+static int dasd_state_online_to_ready(struct dasd_device *device)
+{
+	int rc;
+	struct gendisk *disk;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+
+	if (device->discipline->online_to_ready) {
+		rc = device->discipline->online_to_ready(device);
+		if (rc)
+			return rc;
+	}
+
+	device->state = DASD_STATE_READY;
+	if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
+		disk = device->block->bdev->bd_disk;
+		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+		while ((part = disk_part_iter_next(&piter)))
+			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+		disk_part_iter_exit(&piter);
+	}
+	return 0;
+}
+
+/*
+ * Device startup state changes.
+ */
+static int dasd_increase_state(struct dasd_device *device)
+{
+	int rc;
+
+	rc = 0;
+	if (device->state == DASD_STATE_NEW &&
+	    device->target >= DASD_STATE_KNOWN)
+		rc = dasd_state_new_to_known(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_KNOWN &&
+	    device->target >= DASD_STATE_BASIC)
+		rc = dasd_state_known_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_BASIC &&
+	    device->target >= DASD_STATE_READY)
+		rc = dasd_state_basic_to_ready(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_UNFMT &&
+	    device->target > DASD_STATE_UNFMT)
+		rc = -EPERM;
+
+	if (!rc &&
+	    device->state == DASD_STATE_READY &&
+	    device->target >= DASD_STATE_ONLINE)
+		rc = dasd_state_ready_to_online(device);
+
+	return rc;
+}
+
+/*
+ * Device shutdown state changes.
+ */
+static int dasd_decrease_state(struct dasd_device *device)
+{
+	int rc;
+
+	rc = 0;
+	if (device->state == DASD_STATE_ONLINE &&
+	    device->target <= DASD_STATE_READY)
+		rc = dasd_state_online_to_ready(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_READY &&
+	    device->target <= DASD_STATE_BASIC)
+		rc = dasd_state_ready_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_UNFMT &&
+	    device->target <= DASD_STATE_BASIC)
+		rc = dasd_state_unfmt_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_BASIC &&
+	    device->target <= DASD_STATE_KNOWN)
+		rc = dasd_state_basic_to_known(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_KNOWN &&
+	    device->target <= DASD_STATE_NEW)
+		rc = dasd_state_known_to_new(device);
+
+	return rc;
+}
+
+/*
+ * This is the main startup/shutdown routine.
+ */
+static void dasd_change_state(struct dasd_device *device)
+{
+	int rc;
+
+	if (device->state == device->target)
+		/* Already where we want to go today... */
+		return;
+	if (device->state < device->target)
+		rc = dasd_increase_state(device);
+	else
+		rc = dasd_decrease_state(device);
+	if (rc == -EAGAIN)
+		return;
+	if (rc)
+		device->target = device->state;
+
+	/* let user-space know that the device status changed */
+	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
+
+	if (device->state == device->target)
+		wake_up(&dasd_init_waitq);
+}
+
+/*
+ * Kick starter for devices that did not complete the startup/shutdown
+ * procedure or were sleeping because of a pending state.
+ * dasd_kick_device will schedule a call do do_kick_device to the kernel
+ * event daemon.
+ */
+static void do_kick_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
+	mutex_lock(&device->state_mutex);
+	dasd_change_state(device);
+	mutex_unlock(&device->state_mutex);
+	dasd_schedule_device_bh(device);
+	dasd_put_device(device);
+}
+
+void dasd_kick_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_kick_device to the kernel event daemon. */
+	if (!schedule_work(&device->kick_work))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_kick_device);
+
+/*
+ * dasd_reload_device will schedule a call do do_reload_device to the kernel
+ * event daemon.
+ */
+static void do_reload_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  reload_device);
+	device->discipline->reload(device);
+	dasd_put_device(device);
+}
+
+void dasd_reload_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_reload_device to the kernel event daemon. */
+	if (!schedule_work(&device->reload_device))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_reload_device);
+
+/*
+ * dasd_restore_device will schedule a call do do_restore_device to the kernel
+ * event daemon.
+ */
+static void do_restore_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  restore_device);
+	device->cdev->drv->restore(device->cdev);
+	dasd_put_device(device);
+}
+
+void dasd_restore_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_restore_device to the kernel event daemon. */
+	if (!schedule_work(&device->restore_device))
+		dasd_put_device(device);
+}
+
+/*
+ * Set the target state for a device and starts the state change.
+ */
+void dasd_set_target_state(struct dasd_device *device, int target)
+{
+	dasd_get_device(device);
+	mutex_lock(&device->state_mutex);
+	/* If we are in probeonly mode stop at DASD_STATE_READY. */
+	if (dasd_probeonly && target > DASD_STATE_READY)
+		target = DASD_STATE_READY;
+	if (device->target != target) {
+		if (device->state == target)
+			wake_up(&dasd_init_waitq);
+		device->target = target;
+	}
+	if (device->state != device->target)
+		dasd_change_state(device);
+	mutex_unlock(&device->state_mutex);
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_set_target_state);
+
+/*
+ * Enable devices with device numbers in [from..to].
+ */
+static inline int _wait_for_device(struct dasd_device *device)
+{
+	return (device->state == device->target);
+}
+
+void dasd_enable_device(struct dasd_device *device)
+{
+	dasd_set_target_state(device, DASD_STATE_ONLINE);
+	if (device->state <= DASD_STATE_KNOWN)
+		/* No discipline for device found. */
+		dasd_set_target_state(device, DASD_STATE_NEW);
+	/* Now wait for the devices to come up. */
+	wait_event(dasd_init_waitq, _wait_for_device(device));
+
+	dasd_reload_device(device);
+	if (device->discipline->kick_validate)
+		device->discipline->kick_validate(device);
+}
+EXPORT_SYMBOL(dasd_enable_device);
+
+/*
+ * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
+ */
+
+unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
+
+#ifdef CONFIG_DASD_PROFILE
+struct dasd_profile dasd_global_profile = {
+	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
+};
+static struct dentry *dasd_debugfs_global_entry;
+
+/*
+ * Add profiling information for cqr before execution.
+ */
+static void dasd_profile_start(struct dasd_block *block,
+			       struct dasd_ccw_req *cqr,
+			       struct request *req)
+{
+	struct list_head *l;
+	unsigned int counter;
+	struct dasd_device *device;
+
+	/* count the length of the chanq for statistics */
+	counter = 0;
+	if (dasd_global_profile_level || block->profile.data)
+		list_for_each(l, &block->ccw_queue)
+			if (++counter >= 31)
+				break;
+
+	spin_lock(&dasd_global_profile.lock);
+	if (dasd_global_profile.data) {
+		dasd_global_profile.data->dasd_io_nr_req[counter]++;
+		if (rq_data_dir(req) == READ)
+			dasd_global_profile.data->dasd_read_nr_req[counter]++;
+	}
+	spin_unlock(&dasd_global_profile.lock);
+
+	spin_lock(&block->profile.lock);
+	if (block->profile.data) {
+		block->profile.data->dasd_io_nr_req[counter]++;
+		if (rq_data_dir(req) == READ)
+			block->profile.data->dasd_read_nr_req[counter]++;
+	}
+	spin_unlock(&block->profile.lock);
+
+	/*
+	 * We count the request for the start device, even though it may run on
+	 * some other device due to error recovery. This way we make sure that
+	 * we count each request only once.
+	 */
+	device = cqr->startdev;
+	if (device->profile.data) {
+		counter = 1; /* request is not yet queued on the start device */
+		list_for_each(l, &device->ccw_queue)
+			if (++counter >= 31)
+				break;
+	}
+	spin_lock(&device->profile.lock);
+	if (device->profile.data) {
+		device->profile.data->dasd_io_nr_req[counter]++;
+		if (rq_data_dir(req) == READ)
+			device->profile.data->dasd_read_nr_req[counter]++;
+	}
+	spin_unlock(&device->profile.lock);
+}
+
+/*
+ * Add profiling information for cqr after execution.
+ */
+
+#define dasd_profile_counter(value, index)			   \
+{								   \
+	for (index = 0; index < 31 && value >> (2+index); index++) \
+		;						   \
+}
+
+static void dasd_profile_end_add_data(struct dasd_profile_info *data,
+				      int is_alias,
+				      int is_tpm,
+				      int is_read,
+				      long sectors,
+				      int sectors_ind,
+				      int tottime_ind,
+				      int tottimeps_ind,
+				      int strtime_ind,
+				      int irqtime_ind,
+				      int irqtimeps_ind,
+				      int endtime_ind)
+{
+	/* in case of an overflow, reset the whole profile */
+	if (data->dasd_io_reqs == UINT_MAX) {
+			memset(data, 0, sizeof(*data));
+			ktime_get_real_ts64(&data->starttod);
+	}
+	data->dasd_io_reqs++;
+	data->dasd_io_sects += sectors;
+	if (is_alias)
+		data->dasd_io_alias++;
+	if (is_tpm)
+		data->dasd_io_tpm++;
+
+	data->dasd_io_secs[sectors_ind]++;
+	data->dasd_io_times[tottime_ind]++;
+	data->dasd_io_timps[tottimeps_ind]++;
+	data->dasd_io_time1[strtime_ind]++;
+	data->dasd_io_time2[irqtime_ind]++;
+	data->dasd_io_time2ps[irqtimeps_ind]++;
+	data->dasd_io_time3[endtime_ind]++;
+
+	if (is_read) {
+		data->dasd_read_reqs++;
+		data->dasd_read_sects += sectors;
+		if (is_alias)
+			data->dasd_read_alias++;
+		if (is_tpm)
+			data->dasd_read_tpm++;
+		data->dasd_read_secs[sectors_ind]++;
+		data->dasd_read_times[tottime_ind]++;
+		data->dasd_read_time1[strtime_ind]++;
+		data->dasd_read_time2[irqtime_ind]++;
+		data->dasd_read_time3[endtime_ind]++;
+	}
+}
+
+static void dasd_profile_end(struct dasd_block *block,
+			     struct dasd_ccw_req *cqr,
+			     struct request *req)
+{
+	unsigned long strtime, irqtime, endtime, tottime;
+	unsigned long tottimeps, sectors;
+	struct dasd_device *device;
+	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
+	int irqtime_ind, irqtimeps_ind, endtime_ind;
+	struct dasd_profile_info *data;
+
+	device = cqr->startdev;
+	if (!(dasd_global_profile_level ||
+	      block->profile.data ||
+	      device->profile.data))
+		return;
+
+	sectors = blk_rq_sectors(req);
+	if (!cqr->buildclk || !cqr->startclk ||
+	    !cqr->stopclk || !cqr->endclk ||
+	    !sectors)
+		return;
+
+	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
+	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
+	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
+	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
+	tottimeps = tottime / sectors;
+
+	dasd_profile_counter(sectors, sectors_ind);
+	dasd_profile_counter(tottime, tottime_ind);
+	dasd_profile_counter(tottimeps, tottimeps_ind);
+	dasd_profile_counter(strtime, strtime_ind);
+	dasd_profile_counter(irqtime, irqtime_ind);
+	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
+	dasd_profile_counter(endtime, endtime_ind);
+
+	spin_lock(&dasd_global_profile.lock);
+	if (dasd_global_profile.data) {
+		data = dasd_global_profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(dasd_global_profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&dasd_global_profile.lock);
+
+	spin_lock(&block->profile.lock);
+	if (block->profile.data) {
+		data = block->profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(block->profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&block->profile.lock);
+
+	spin_lock(&device->profile.lock);
+	if (device->profile.data) {
+		data = device->profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(device->profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&device->profile.lock);
+}
+
+void dasd_profile_reset(struct dasd_profile *profile)
+{
+	struct dasd_profile_info *data;
+
+	spin_lock_bh(&profile->lock);
+	data = profile->data;
+	if (!data) {
+		spin_unlock_bh(&profile->lock);
+		return;
+	}
+	memset(data, 0, sizeof(*data));
+	ktime_get_real_ts64(&data->starttod);
+	spin_unlock_bh(&profile->lock);
+}
+
+int dasd_profile_on(struct dasd_profile *profile)
+{
+	struct dasd_profile_info *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	spin_lock_bh(&profile->lock);
+	if (profile->data) {
+		spin_unlock_bh(&profile->lock);
+		kfree(data);
+		return 0;
+	}
+	ktime_get_real_ts64(&data->starttod);
+	profile->data = data;
+	spin_unlock_bh(&profile->lock);
+	return 0;
+}
+
+void dasd_profile_off(struct dasd_profile *profile)
+{
+	spin_lock_bh(&profile->lock);
+	kfree(profile->data);
+	profile->data = NULL;
+	spin_unlock_bh(&profile->lock);
+}
+
+char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
+{
+	char *buffer;
+
+	buffer = vmalloc(user_len + 1);
+	if (buffer == NULL)
+		return ERR_PTR(-ENOMEM);
+	if (copy_from_user(buffer, user_buf, user_len) != 0) {
+		vfree(buffer);
+		return ERR_PTR(-EFAULT);
+	}
+	/* got the string, now strip linefeed. */
+	if (buffer[user_len - 1] == '\n')
+		buffer[user_len - 1] = 0;
+	else
+		buffer[user_len] = 0;
+	return buffer;
+}
+
+static ssize_t dasd_stats_write(struct file *file,
+				const char __user *user_buf,
+				size_t user_len, loff_t *pos)
+{
+	char *buffer, *str;
+	int rc;
+	struct seq_file *m = (struct seq_file *)file->private_data;
+	struct dasd_profile *prof = m->private;
+
+	if (user_len > 65536)
+		user_len = 65536;
+	buffer = dasd_get_user_string(user_buf, user_len);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	str = skip_spaces(buffer);
+	rc = user_len;
+	if (strncmp(str, "reset", 5) == 0) {
+		dasd_profile_reset(prof);
+	} else if (strncmp(str, "on", 2) == 0) {
+		rc = dasd_profile_on(prof);
+		if (rc)
+			goto out;
+		rc = user_len;
+		if (prof == &dasd_global_profile) {
+			dasd_profile_reset(prof);
+			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
+		}
+	} else if (strncmp(str, "off", 3) == 0) {
+		if (prof == &dasd_global_profile)
+			dasd_global_profile_level = DASD_PROFILE_OFF;
+		dasd_profile_off(prof);
+	} else
+		rc = -EINVAL;
+out:
+	vfree(buffer);
+	return rc;
+}
+
+static void dasd_stats_array(struct seq_file *m, unsigned int *array)
+{
+	int i;
+
+	for (i = 0; i < 32; i++)
+		seq_printf(m, "%u ", array[i]);
+	seq_putc(m, '\n');
+}
+
+static void dasd_stats_seq_print(struct seq_file *m,
+				 struct dasd_profile_info *data)
+{
+	seq_printf(m, "start_time %lld.%09ld\n",
+		   (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
+	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
+	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
+	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
+	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
+	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
+	seq_puts(m, "histogram_sectors ");
+	dasd_stats_array(m, data->dasd_io_secs);
+	seq_puts(m, "histogram_io_times ");
+	dasd_stats_array(m, data->dasd_io_times);
+	seq_puts(m, "histogram_io_times_weighted ");
+	dasd_stats_array(m, data->dasd_io_timps);
+	seq_puts(m, "histogram_time_build_to_ssch ");
+	dasd_stats_array(m, data->dasd_io_time1);
+	seq_puts(m, "histogram_time_ssch_to_irq ");
+	dasd_stats_array(m, data->dasd_io_time2);
+	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
+	dasd_stats_array(m, data->dasd_io_time2ps);
+	seq_puts(m, "histogram_time_irq_to_end ");
+	dasd_stats_array(m, data->dasd_io_time3);
+	seq_puts(m, "histogram_ccw_queue_length ");
+	dasd_stats_array(m, data->dasd_io_nr_req);
+	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
+	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
+	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
+	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
+	seq_puts(m, "histogram_read_sectors ");
+	dasd_stats_array(m, data->dasd_read_secs);
+	seq_puts(m, "histogram_read_times ");
+	dasd_stats_array(m, data->dasd_read_times);
+	seq_puts(m, "histogram_read_time_build_to_ssch ");
+	dasd_stats_array(m, data->dasd_read_time1);
+	seq_puts(m, "histogram_read_time_ssch_to_irq ");
+	dasd_stats_array(m, data->dasd_read_time2);
+	seq_puts(m, "histogram_read_time_irq_to_end ");
+	dasd_stats_array(m, data->dasd_read_time3);
+	seq_puts(m, "histogram_read_ccw_queue_length ");
+	dasd_stats_array(m, data->dasd_read_nr_req);
+}
+
+static int dasd_stats_show(struct seq_file *m, void *v)
+{
+	struct dasd_profile *profile;
+	struct dasd_profile_info *data;
+
+	profile = m->private;
+	spin_lock_bh(&profile->lock);
+	data = profile->data;
+	if (!data) {
+		spin_unlock_bh(&profile->lock);
+		seq_puts(m, "disabled\n");
+		return 0;
+	}
+	dasd_stats_seq_print(m, data);
+	spin_unlock_bh(&profile->lock);
+	return 0;
+}
+
+static int dasd_stats_open(struct inode *inode, struct file *file)
+{
+	struct dasd_profile *profile = inode->i_private;
+	return single_open(file, dasd_stats_show, profile);
+}
+
+static const struct file_operations dasd_stats_raw_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= dasd_stats_write,
+};
+
+static void dasd_profile_init(struct dasd_profile *profile,
+			      struct dentry *base_dentry)
+{
+	umode_t mode;
+	struct dentry *pde;
+
+	if (!base_dentry)
+		return;
+	profile->dentry = NULL;
+	profile->data = NULL;
+	mode = (S_IRUSR | S_IWUSR | S_IFREG);
+	pde = debugfs_create_file("statistics", mode, base_dentry,
+				  profile, &dasd_stats_raw_fops);
+	if (pde && !IS_ERR(pde))
+		profile->dentry = pde;
+	return;
+}
+
+static void dasd_profile_exit(struct dasd_profile *profile)
+{
+	dasd_profile_off(profile);
+	debugfs_remove(profile->dentry);
+	profile->dentry = NULL;
+}
+
+static void dasd_statistics_removeroot(void)
+{
+	dasd_global_profile_level = DASD_PROFILE_OFF;
+	dasd_profile_exit(&dasd_global_profile);
+	debugfs_remove(dasd_debugfs_global_entry);
+	debugfs_remove(dasd_debugfs_root_entry);
+}
+
+static void dasd_statistics_createroot(void)
+{
+	struct dentry *pde;
+
+	dasd_debugfs_root_entry = NULL;
+	pde = debugfs_create_dir("dasd", NULL);
+	if (!pde || IS_ERR(pde))
+		goto error;
+	dasd_debugfs_root_entry = pde;
+	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
+	if (!pde || IS_ERR(pde))
+		goto error;
+	dasd_debugfs_global_entry = pde;
+	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
+	return;
+
+error:
+	DBF_EVENT(DBF_ERR, "%s",
+		  "Creation of the dasd debugfs interface failed");
+	dasd_statistics_removeroot();
+	return;
+}
+
+#else
+#define dasd_profile_start(block, cqr, req) do {} while (0)
+#define dasd_profile_end(block, cqr, req) do {} while (0)
+
+static void dasd_statistics_createroot(void)
+{
+	return;
+}
+
+static void dasd_statistics_removeroot(void)
+{
+	return;
+}
+
+int dasd_stats_generic_show(struct seq_file *m, void *v)
+{
+	seq_puts(m, "Statistics are not activated in this kernel\n");
+	return 0;
+}
+
+static void dasd_profile_init(struct dasd_profile *profile,
+			      struct dentry *base_dentry)
+{
+	return;
+}
+
+static void dasd_profile_exit(struct dasd_profile *profile)
+{
+	return;
+}
+
+int dasd_profile_on(struct dasd_profile *profile)
+{
+	return 0;
+}
+
+#endif				/* CONFIG_DASD_PROFILE */
+
+static int dasd_hosts_show(struct seq_file *m, void *v)
+{
+	struct dasd_device *device;
+	int rc = -EOPNOTSUPP;
+
+	device = m->private;
+	dasd_get_device(device);
+
+	if (device->discipline->hosts_print)
+		rc = device->discipline->hosts_print(device, m);
+
+	dasd_put_device(device);
+	return rc;
+}
+
+static int dasd_hosts_open(struct inode *inode, struct file *file)
+{
+	struct dasd_device *device = inode->i_private;
+
+	return single_open(file, dasd_hosts_show, device);
+}
+
+static const struct file_operations dasd_hosts_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_hosts_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void dasd_hosts_exit(struct dasd_device *device)
+{
+	debugfs_remove(device->hosts_dentry);
+	device->hosts_dentry = NULL;
+}
+
+static void dasd_hosts_init(struct dentry *base_dentry,
+			    struct dasd_device *device)
+{
+	struct dentry *pde;
+	umode_t mode;
+
+	if (!base_dentry)
+		return;
+
+	mode = S_IRUSR | S_IFREG;
+	pde = debugfs_create_file("host_access_list", mode, base_dentry,
+				  device, &dasd_hosts_fops);
+	if (pde && !IS_ERR(pde))
+		device->hosts_dentry = pde;
+}
+
+struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
+					  struct dasd_device *device,
+					  struct dasd_ccw_req *cqr)
+{
+	unsigned long flags;
+	char *data, *chunk;
+	int size = 0;
+
+	if (cplength > 0)
+		size += cplength * sizeof(struct ccw1);
+	if (datasize > 0)
+		size += datasize;
+	if (!cqr)
+		size += (sizeof(*cqr) + 7L) & -8L;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	if (!chunk)
+		return ERR_PTR(-ENOMEM);
+	if (!cqr) {
+		cqr = (void *) data;
+		data += (sizeof(*cqr) + 7L) & -8L;
+	}
+	memset(cqr, 0, sizeof(*cqr));
+	cqr->mem_chunk = chunk;
+	if (cplength > 0) {
+		cqr->cpaddr = data;
+		data += cplength * sizeof(struct ccw1);
+		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
+	}
+	if (datasize > 0) {
+		cqr->data = data;
+ 		memset(cqr->data, 0, datasize);
+	}
+	cqr->magic = magic;
+	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	dasd_get_device(device);
+	return cqr;
+}
+EXPORT_SYMBOL(dasd_smalloc_request);
+
+void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_sfree_request);
+
+/*
+ * Check discipline magic in cqr.
+ */
+static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+
+	if (cqr == NULL)
+		return -EINVAL;
+	device = cqr->startdev;
+	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			    " dasd_ccw_req 0x%08x magic doesn't match"
+			    " discipline 0x%08x",
+			    cqr->magic,
+			    *(unsigned int *) device->discipline->name);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * Terminate the current i/o and set the request to clear_pending.
+ * Timer keeps device runnig.
+ * ccw_device_clear can fail if the i/o subsystem
+ * is in a bad mood.
+ */
+int dasd_term_IO(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int retries, rc;
+	char errorstring[ERRORLENGTH];
+
+	/* Check the cqr */
+	rc = dasd_check_cqr(cqr);
+	if (rc)
+		return rc;
+	retries = 0;
+	device = (struct dasd_device *) cqr->startdev;
+	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
+		rc = ccw_device_clear(device->cdev, (long) cqr);
+		switch (rc) {
+		case 0:	/* termination successful */
+			cqr->status = DASD_CQR_CLEAR_PENDING;
+			cqr->stopclk = get_tod_clock();
+			cqr->starttime = 0;
+			DBF_DEV_EVENT(DBF_DEBUG, device,
+				      "terminate cqr %p successful",
+				      cqr);
+			break;
+		case -ENODEV:
+			DBF_DEV_EVENT(DBF_ERR, device, "%s",
+				      "device gone, retry");
+			break;
+		case -EINVAL:
+			/*
+			 * device not valid so no I/O could be running
+			 * handle CQR as termination successful
+			 */
+			cqr->status = DASD_CQR_CLEARED;
+			cqr->stopclk = get_tod_clock();
+			cqr->starttime = 0;
+			/* no retries for invalid devices */
+			cqr->retries = -1;
+			DBF_DEV_EVENT(DBF_ERR, device, "%s",
+				      "EINVAL, handle as terminated");
+			/* fake rc to success */
+			rc = 0;
+			break;
+		default:
+			/* internal error 10 - unknown rc*/
+			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
+			dev_err(&device->cdev->dev, "An error occurred in the "
+				"DASD device driver, reason=%s\n", errorstring);
+			BUG();
+			break;
+		}
+		retries++;
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+EXPORT_SYMBOL(dasd_term_IO);
+
+/*
+ * Start the i/o. This start_IO can fail if the channel is really busy.
+ * In that case set up a timer to start the request later.
+ */
+int dasd_start_IO(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+	char errorstring[ERRORLENGTH];
+
+	/* Check the cqr */
+	rc = dasd_check_cqr(cqr);
+	if (rc) {
+		cqr->intrc = rc;
+		return rc;
+	}
+	device = (struct dasd_device *) cqr->startdev;
+	if (((cqr->block &&
+	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
+	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
+	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
+			      "because of stolen lock", cqr);
+		cqr->status = DASD_CQR_ERROR;
+		cqr->intrc = -EPERM;
+		return -EPERM;
+	}
+	if (cqr->retries < 0) {
+		/* internal error 14 - start_IO run out of retries */
+		sprintf(errorstring, "14 %p", cqr);
+		dev_err(&device->cdev->dev, "An error occurred in the DASD "
+			"device driver, reason=%s\n", errorstring);
+		cqr->status = DASD_CQR_ERROR;
+		return -EIO;
+	}
+	cqr->startclk = get_tod_clock();
+	cqr->starttime = jiffies;
+	cqr->retries--;
+	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+		cqr->lpm &= dasd_path_get_opm(device);
+		if (!cqr->lpm)
+			cqr->lpm = dasd_path_get_opm(device);
+	}
+	if (cqr->cpmode == 1) {
+		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
+					 (long) cqr, cqr->lpm);
+	} else {
+		rc = ccw_device_start(device->cdev, cqr->cpaddr,
+				      (long) cqr, cqr->lpm, 0);
+	}
+	switch (rc) {
+	case 0:
+		cqr->status = DASD_CQR_IN_IO;
+		break;
+	case -EBUSY:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: device busy, retry later");
+		break;
+	case -EACCES:
+		/* -EACCES indicates that the request used only a subset of the
+		 * available paths and all these paths are gone. If the lpm of
+		 * this request was only a subset of the opm (e.g. the ppm) then
+		 * we just do a retry with all available paths.
+		 * If we already use the full opm, something is amiss, and we
+		 * need a full path verification.
+		 */
+		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			DBF_DEV_EVENT(DBF_WARNING, device,
+				      "start_IO: selected paths gone (%x)",
+				      cqr->lpm);
+		} else if (cqr->lpm != dasd_path_get_opm(device)) {
+			cqr->lpm = dasd_path_get_opm(device);
+			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+				      "start_IO: selected paths gone,"
+				      " retry on all paths");
+		} else {
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "start_IO: all paths in opm gone,"
+				      " do path verification");
+			dasd_generic_last_path_gone(device);
+			dasd_path_no_path(device);
+			dasd_path_set_tbvpm(device,
+					  ccw_device_get_path_mask(
+						  device->cdev));
+		}
+		break;
+	case -ENODEV:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -ENODEV device gone, retry");
+		break;
+	case -EIO:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -EIO device gone, retry");
+		break;
+	case -EINVAL:
+		/* most likely caused in power management context */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -EINVAL device currently "
+			      "not accessible");
+		break;
+	default:
+		/* internal error 11 - unknown rc */
+		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
+		dev_err(&device->cdev->dev,
+			"An error occurred in the DASD device driver, "
+			"reason=%s\n", errorstring);
+		BUG();
+		break;
+	}
+	cqr->intrc = rc;
+	return rc;
+}
+EXPORT_SYMBOL(dasd_start_IO);
+
+/*
+ * Timeout function for dasd devices. This is used for different purposes
+ *  1) missing interrupt handler for normal operation
+ *  2) delayed start of request where start_IO failed with -EBUSY
+ *  3) timeout for missing state change interrupts
+ * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
+ * DASD_CQR_QUEUED for 2) and 3).
+ */
+static void dasd_device_timeout(struct timer_list *t)
+{
+	unsigned long flags;
+	struct dasd_device *device;
+
+	device = from_timer(device, t, timer);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	/* re-activate request queue */
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	dasd_schedule_device_bh(device);
+}
+
+/*
+ * Setup timeout for a device in jiffies.
+ */
+void dasd_device_set_timer(struct dasd_device *device, int expires)
+{
+	if (expires == 0)
+		del_timer(&device->timer);
+	else
+		mod_timer(&device->timer, jiffies + expires);
+}
+EXPORT_SYMBOL(dasd_device_set_timer);
+
+/*
+ * Clear timeout for a device.
+ */
+void dasd_device_clear_timer(struct dasd_device *device)
+{
+	del_timer(&device->timer);
+}
+EXPORT_SYMBOL(dasd_device_clear_timer);
+
+static void dasd_handle_killed_request(struct ccw_device *cdev,
+				       unsigned long intparm)
+{
+	struct dasd_ccw_req *cqr;
+	struct dasd_device *device;
+
+	if (!intparm)
+		return;
+	cqr = (struct dasd_ccw_req *) intparm;
+	if (cqr->status != DASD_CQR_IN_IO) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
+				"invalid status in handle_killed_request: "
+				"%02x", cqr->status);
+		return;
+	}
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"unable to get device from cdev");
+		return;
+	}
+
+	if (!cqr->startdev ||
+	    device != cqr->startdev ||
+	    strncmp(cqr->startdev->discipline->ebcname,
+		    (char *) &cqr->magic, 4)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"invalid device in request");
+		dasd_put_device(device);
+		return;
+	}
+
+	/* Schedule request to be retried. */
+	cqr->status = DASD_CQR_QUEUED;
+
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+	dasd_put_device(device);
+}
+
+void dasd_generic_handle_state_change(struct dasd_device *device)
+{
+	/* First of all start sense subsystem status request. */
+	dasd_eer_snss(device);
+
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
+	dasd_schedule_device_bh(device);
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->request_queue)
+			blk_mq_run_hw_queues(device->block->request_queue,
+					     true);
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
+
+static int dasd_check_hpf_error(struct irb *irb)
+{
+	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
+	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
+	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
+}
+
+/*
+ * Interrupt handler for "normal" ssch-io based dasd devices.
+ */
+void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
+		      struct irb *irb)
+{
+	struct dasd_ccw_req *cqr, *next;
+	struct dasd_device *device;
+	unsigned long now;
+	int nrf_suppressed = 0;
+	int fp_suppressed = 0;
+	u8 *sense = NULL;
+	int expires;
+
+	cqr = (struct dasd_ccw_req *) intparm;
+	if (IS_ERR(irb)) {
+		switch (PTR_ERR(irb)) {
+		case -EIO:
+			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
+				device = cqr->startdev;
+				cqr->status = DASD_CQR_CLEARED;
+				dasd_device_clear_timer(device);
+				wake_up(&dasd_flush_wq);
+				dasd_schedule_device_bh(device);
+				return;
+			}
+			break;
+		case -ETIMEDOUT:
+			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
+					"request timed out\n", __func__);
+			break;
+		default:
+			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
+					"unknown error %ld\n", __func__,
+					PTR_ERR(irb));
+		}
+		dasd_handle_killed_request(cdev, intparm);
+		return;
+	}
+
+	now = get_tod_clock();
+	/* check for conditions that should be handled immediately */
+	if (!cqr ||
+	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+	      scsw_cstat(&irb->scsw) == 0)) {
+		if (cqr)
+			memcpy(&cqr->irb, irb, sizeof(*irb));
+		device = dasd_device_from_cdev_locked(cdev);
+		if (IS_ERR(device))
+			return;
+		/* ignore unsolicited interrupts for DIAG discipline */
+		if (device->discipline == dasd_diag_discipline_pointer) {
+			dasd_put_device(device);
+			return;
+		}
+
+		/*
+		 * In some cases 'File Protected' or 'No Record Found' errors
+		 * might be expected and debug log messages for the
+		 * corresponding interrupts shouldn't be written then.
+		 * Check if either of the according suppress bits is set.
+		 */
+		sense = dasd_get_sense(irb);
+		if (sense) {
+			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
+				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
+			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
+				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+		}
+		if (!(fp_suppressed || nrf_suppressed))
+			device->discipline->dump_sense_dbf(device, irb, "int");
+
+		if (device->features & DASD_FEATURE_ERPLOG)
+			device->discipline->dump_sense(device, cqr, irb);
+		device->discipline->check_for_device_change(device, cqr, irb);
+		dasd_put_device(device);
+	}
+
+	/* check for for attention message */
+	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
+		device = dasd_device_from_cdev_locked(cdev);
+		if (!IS_ERR(device)) {
+			device->discipline->check_attention(device,
+							    irb->esw.esw1.lpum);
+			dasd_put_device(device);
+		}
+	}
+
+	if (!cqr)
+		return;
+
+	device = (struct dasd_device *) cqr->startdev;
+	if (!device ||
+	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"invalid device in request");
+		return;
+	}
+
+	/* Check for clear pending */
+	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
+	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
+		cqr->status = DASD_CQR_CLEARED;
+		dasd_device_clear_timer(device);
+		wake_up(&dasd_flush_wq);
+		dasd_schedule_device_bh(device);
+		return;
+	}
+
+	/* check status - the request might have been killed by dyn detach */
+	if (cqr->status != DASD_CQR_IN_IO) {
+		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
+			      "status %02x", dev_name(&cdev->dev), cqr->status);
+		return;
+	}
+
+	next = NULL;
+	expires = 0;
+	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+	    scsw_cstat(&irb->scsw) == 0) {
+		/* request was completed successfully */
+		cqr->status = DASD_CQR_SUCCESS;
+		cqr->stopclk = now;
+		/* Start first request on queue if possible -> fast_io. */
+		if (cqr->devlist.next != &device->ccw_queue) {
+			next = list_entry(cqr->devlist.next,
+					  struct dasd_ccw_req, devlist);
+		}
+	} else {  /* error */
+		/* check for HPF error
+		 * call discipline function to requeue all requests
+		 * and disable HPF accordingly
+		 */
+		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
+		    device->discipline->handle_hpf_error)
+			device->discipline->handle_hpf_error(device, irb);
+		/*
+		 * If we don't want complex ERP for this request, then just
+		 * reset this and retry it in the fastpath
+		 */
+		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
+		    cqr->retries > 0) {
+			if (cqr->lpm == dasd_path_get_opm(device))
+				DBF_DEV_EVENT(DBF_DEBUG, device,
+					      "default ERP in fastpath "
+					      "(%i retries left)",
+					      cqr->retries);
+			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
+				cqr->lpm = dasd_path_get_opm(device);
+			cqr->status = DASD_CQR_QUEUED;
+			next = cqr;
+		} else
+			cqr->status = DASD_CQR_ERROR;
+	}
+	if (next && (next->status == DASD_CQR_QUEUED) &&
+	    (!device->stopped)) {
+		if (device->discipline->start_IO(next) == 0)
+			expires = next->expires;
+	}
+	if (expires != 0)
+		dasd_device_set_timer(device, expires);
+	else
+		dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+}
+EXPORT_SYMBOL(dasd_int_handler);
+
+enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
+{
+	struct dasd_device *device;
+
+	device = dasd_device_from_cdev_locked(cdev);
+
+	if (IS_ERR(device))
+		goto out;
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
+	   device->state != device->target ||
+	   !device->discipline->check_for_device_change){
+		dasd_put_device(device);
+		goto out;
+	}
+	if (device->discipline->dump_sense_dbf)
+		device->discipline->dump_sense_dbf(device, irb, "uc");
+	device->discipline->check_for_device_change(device, NULL, irb);
+	dasd_put_device(device);
+out:
+	return UC_TODO_RETRY;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
+
+/*
+ * If we have an error on a dasd_block layer request then we cancel
+ * and return all further requests from the same dasd_block as well.
+ */
+static void __dasd_device_recovery(struct dasd_device *device,
+				   struct dasd_ccw_req *ref_cqr)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+
+	/*
+	 * only requeue request that came from the dasd_block layer
+	 */
+	if (!ref_cqr->block)
+		return;
+
+	list_for_each_safe(l, n, &device->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+		if (cqr->status == DASD_CQR_QUEUED &&
+		    ref_cqr->block == cqr->block) {
+			cqr->status = DASD_CQR_CLEARED;
+		}
+	}
+};
+
+/*
+ * Remove those ccw requests from the queue that need to be returned
+ * to the upper layer.
+ */
+static void __dasd_device_process_ccw_queue(struct dasd_device *device,
+					    struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+
+	/* Process request with final status. */
+	list_for_each_safe(l, n, &device->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+
+		/* Skip any non-final request. */
+		if (cqr->status == DASD_CQR_QUEUED ||
+		    cqr->status == DASD_CQR_IN_IO ||
+		    cqr->status == DASD_CQR_CLEAR_PENDING)
+			continue;
+		if (cqr->status == DASD_CQR_ERROR) {
+			__dasd_device_recovery(device, cqr);
+		}
+		/* Rechain finished requests to final queue */
+		list_move_tail(&cqr->devlist, final_queue);
+	}
+}
+
+static void __dasd_process_cqr(struct dasd_device *device,
+			       struct dasd_ccw_req *cqr)
+{
+	char errorstring[ERRORLENGTH];
+
+	switch (cqr->status) {
+	case DASD_CQR_SUCCESS:
+		cqr->status = DASD_CQR_DONE;
+		break;
+	case DASD_CQR_ERROR:
+		cqr->status = DASD_CQR_NEED_ERP;
+		break;
+	case DASD_CQR_CLEARED:
+		cqr->status = DASD_CQR_TERMINATED;
+		break;
+	default:
+		/* internal error 12 - wrong cqr status*/
+		snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
+		dev_err(&device->cdev->dev,
+			"An error occurred in the DASD device driver, "
+			"reason=%s\n", errorstring);
+		BUG();
+	}
+	if (cqr->callback)
+		cqr->callback(cqr, cqr->callback_data);
+}
+
+/*
+ * the cqrs from the final queue are returned to the upper layer
+ * by setting a dasd_block state and calling the callback function
+ */
+static void __dasd_device_process_final_queue(struct dasd_device *device,
+					      struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	struct dasd_block *block;
+
+	list_for_each_safe(l, n, final_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+		list_del_init(&cqr->devlist);
+		block = cqr->block;
+		if (!block) {
+			__dasd_process_cqr(device, cqr);
+		} else {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_cqr(device, cqr);
+			spin_unlock_bh(&block->queue_lock);
+		}
+	}
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it reached its expire time. If so, terminate the IO.
+ */
+static void __dasd_device_check_expire(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+
+	if (list_empty(&device->ccw_queue))
+		return;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
+	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
+		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			/*
+			 * IO in safe offline processing should not
+			 * run out of retries
+			 */
+			cqr->retries++;
+		}
+		if (device->discipline->term_IO(cqr) != 0) {
+			/* Hmpf, try again in 5 sec */
+			dev_err(&device->cdev->dev,
+				"cqr %p timed out (%lus) but cannot be "
+				"ended, retrying in 5 s\n",
+				cqr, (cqr->expires/HZ));
+			cqr->expires += 5*HZ;
+			dasd_device_set_timer(device, 5*HZ);
+		} else {
+			dev_err(&device->cdev->dev,
+				"cqr %p timed out (%lus), %i retries "
+				"remaining\n", cqr, (cqr->expires/HZ),
+				cqr->retries);
+		}
+	}
+}
+
+/*
+ * return 1 when device is not eligible for IO
+ */
+static int __dasd_device_is_unusable(struct dasd_device *device,
+				     struct dasd_ccw_req *cqr)
+{
+	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
+
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
+	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/*
+		 * dasd is being set offline
+		 * but it is no safe offline where we have to allow I/O
+		 */
+		return 1;
+	}
+	if (device->stopped) {
+		if (device->stopped & mask) {
+			/* stopped and CQR will not change that. */
+			return 1;
+		}
+		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			/* CQR is not able to change device to
+			 * operational. */
+			return 1;
+		}
+		/* CQR required to get device operational. */
+	}
+	return 0;
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it needs to be started.
+ */
+static void __dasd_device_start_head(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+
+	if (list_empty(&device->ccw_queue))
+		return;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	if (cqr->status != DASD_CQR_QUEUED)
+		return;
+	/* if device is not usable return request to upper layer */
+	if (__dasd_device_is_unusable(device, cqr)) {
+		cqr->intrc = -EAGAIN;
+		cqr->status = DASD_CQR_CLEARED;
+		dasd_schedule_device_bh(device);
+		return;
+	}
+
+	rc = device->discipline->start_IO(cqr);
+	if (rc == 0)
+		dasd_device_set_timer(device, cqr->expires);
+	else if (rc == -EACCES) {
+		dasd_schedule_device_bh(device);
+	} else
+		/* Hmpf, try again in 1/2 sec */
+		dasd_device_set_timer(device, 50);
+}
+
+static void __dasd_device_check_path_events(struct dasd_device *device)
+{
+	int rc;
+
+	if (!dasd_path_get_tbvpm(device))
+		return;
+
+	if (device->stopped &
+	    ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
+		return;
+	rc = device->discipline->verify_path(device,
+					     dasd_path_get_tbvpm(device));
+	if (rc)
+		dasd_device_set_timer(device, 50);
+	else
+		dasd_path_clear_all_verify(device);
+};
+
+/*
+ * Go through all request on the dasd_device request queue,
+ * terminate them on the cdev if necessary, and return them to the
+ * submitting layer via callback.
+ * Note:
+ * Make sure that all 'submitting layers' still exist when
+ * this function is called!. In other words, when 'device' is a base
+ * device then all block layer requests must have been removed before
+ * via dasd_flush_block_queue.
+ */
+int dasd_flush_device_queue(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr, *n;
+	int rc;
+	struct list_head flush_queue;
+
+	INIT_LIST_HEAD(&flush_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = 0;
+	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
+		/* Check status and move request to flush_queue */
+		switch (cqr->status) {
+		case DASD_CQR_IN_IO:
+			rc = device->discipline->term_IO(cqr);
+			if (rc) {
+				/* unable to terminate requeust */
+				dev_err(&device->cdev->dev,
+					"Flushing the DASD request queue "
+					"failed for request %p\n", cqr);
+				/* stop flush processing */
+				goto finished;
+			}
+			break;
+		case DASD_CQR_QUEUED:
+			cqr->stopclk = get_tod_clock();
+			cqr->status = DASD_CQR_CLEARED;
+			break;
+		default: /* no need to modify the others */
+			break;
+		}
+		list_move_tail(&cqr->devlist, &flush_queue);
+	}
+finished:
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	/*
+	 * After this point all requests must be in state CLEAR_PENDING,
+	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
+	 * one of the others.
+	 */
+	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
+		wait_event(dasd_flush_wq,
+			   (cqr->status != DASD_CQR_CLEAR_PENDING));
+	/*
+	 * Now set each request back to TERMINATED, DONE or NEED_ERP
+	 * and call the callback function of flushed requests
+	 */
+	__dasd_device_process_final_queue(device, &flush_queue);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
+
+/*
+ * Acquire the device lock and process queues for the device.
+ */
+static void dasd_device_tasklet(unsigned long data)
+{
+	struct dasd_device *device = (struct dasd_device *) data;
+	struct list_head final_queue;
+
+	atomic_set (&device->tasklet_scheduled, 0);
+	INIT_LIST_HEAD(&final_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	/* Check expire time of first request on the ccw queue. */
+	__dasd_device_check_expire(device);
+	/* find final requests on ccw queue */
+	__dasd_device_process_ccw_queue(device, &final_queue);
+	__dasd_device_check_path_events(device);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	/* Now call the callback function of requests with final status */
+	__dasd_device_process_final_queue(device, &final_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	/* Now check if the head of the ccw queue needs to be started. */
+	__dasd_device_start_head(device);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	if (waitqueue_active(&shutdown_waitq))
+		wake_up(&shutdown_waitq);
+	dasd_put_device(device);
+}
+
+/*
+ * Schedules a call to dasd_tasklet over the device tasklet.
+ */
+void dasd_schedule_device_bh(struct dasd_device *device)
+{
+	/* Protect against rescheduling. */
+	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
+		return;
+	dasd_get_device(device);
+	tasklet_hi_schedule(&device->tasklet);
+}
+EXPORT_SYMBOL(dasd_schedule_device_bh);
+
+void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
+{
+	device->stopped |= bits;
+}
+EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
+
+void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
+{
+	device->stopped &= ~bits;
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
+
+/*
+ * Queue a request to the head of the device ccw_queue.
+ * Start the I/O if possible.
+ */
+void dasd_add_request_head(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+
+	device = cqr->startdev;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	cqr->status = DASD_CQR_QUEUED;
+	list_add(&cqr->devlist, &device->ccw_queue);
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+EXPORT_SYMBOL(dasd_add_request_head);
+
+/*
+ * Queue a request to the tail of the device ccw_queue.
+ * Start the I/O if possible.
+ */
+void dasd_add_request_tail(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+
+	device = cqr->startdev;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	cqr->status = DASD_CQR_QUEUED;
+	list_add_tail(&cqr->devlist, &device->ccw_queue);
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+EXPORT_SYMBOL(dasd_add_request_tail);
+
+/*
+ * Wakeup helper for the 'sleep_on' functions.
+ */
+void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	cqr->callback_data = DASD_SLEEPON_END_TAG;
+	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
+
+static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+
+	device = cqr->startdev;
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	return rc;
+}
+
+/*
+ * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
+ */
+static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	dasd_erp_fn_t erp_fn;
+
+	if (cqr->status == DASD_CQR_FILLED)
+		return 0;
+	device = cqr->startdev;
+	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
+		if (cqr->status == DASD_CQR_TERMINATED) {
+			device->discipline->handle_terminated_request(cqr);
+			return 1;
+		}
+		if (cqr->status == DASD_CQR_NEED_ERP) {
+			erp_fn = device->discipline->erp_action(cqr);
+			erp_fn(cqr);
+			return 1;
+		}
+		if (cqr->status == DASD_CQR_FAILED)
+			dasd_log_sense(cqr, &cqr->irb);
+		if (cqr->refers) {
+			__dasd_process_erp(device, cqr);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
+{
+	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
+		if (cqr->refers) /* erp is not done yet */
+			return 1;
+		return ((cqr->status != DASD_CQR_DONE) &&
+			(cqr->status != DASD_CQR_FAILED));
+	} else
+		return (cqr->status == DASD_CQR_FILLED);
+}
+
+static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
+{
+	struct dasd_device *device;
+	int rc;
+	struct list_head ccw_queue;
+	struct dasd_ccw_req *cqr;
+
+	INIT_LIST_HEAD(&ccw_queue);
+	maincqr->status = DASD_CQR_FILLED;
+	device = maincqr->startdev;
+	list_add(&maincqr->blocklist, &ccw_queue);
+	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
+	     cqr = list_first_entry(&ccw_queue,
+				    struct dasd_ccw_req, blocklist)) {
+
+		if (__dasd_sleep_on_erp(cqr))
+			continue;
+		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
+			continue;
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			continue;
+		}
+		/* Non-temporary stop condition will trigger fail fast */
+		if (device->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    (!dasd_eer_enabled(device))) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENOLINK;
+			continue;
+		}
+		/*
+		 * Don't try to start requests if device is in
+		 * offline processing, it might wait forever
+		 */
+		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENODEV;
+			continue;
+		}
+		/*
+		 * Don't try to start requests if device is stopped
+		 * except path verification requests
+		 */
+		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			if (interruptible) {
+				rc = wait_event_interruptible(
+					generic_waitq, !(device->stopped));
+				if (rc == -ERESTARTSYS) {
+					cqr->status = DASD_CQR_FAILED;
+					maincqr->intrc = rc;
+					continue;
+				}
+			} else
+				wait_event(generic_waitq, !(device->stopped));
+		}
+		if (!cqr->callback)
+			cqr->callback = dasd_wakeup_cb;
+
+		cqr->callback_data = DASD_SLEEPON_START_TAG;
+		dasd_add_request_tail(cqr);
+		if (interruptible) {
+			rc = wait_event_interruptible(
+				generic_waitq, _wait_for_wakeup(cqr));
+			if (rc == -ERESTARTSYS) {
+				dasd_cancel_req(cqr);
+				/* wait (non-interruptible) for final status */
+				wait_event(generic_waitq,
+					   _wait_for_wakeup(cqr));
+				cqr->status = DASD_CQR_FAILED;
+				maincqr->intrc = rc;
+				continue;
+			}
+		} else
+			wait_event(generic_waitq, _wait_for_wakeup(cqr));
+	}
+
+	maincqr->endclk = get_tod_clock();
+	if ((maincqr->status != DASD_CQR_DONE) &&
+	    (maincqr->intrc != -ERESTARTSYS))
+		dasd_log_sense(maincqr, &maincqr->irb);
+	if (maincqr->status == DASD_CQR_DONE)
+		rc = 0;
+	else if (maincqr->intrc)
+		rc = maincqr->intrc;
+	else
+		rc = -EIO;
+	return rc;
+}
+
+static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
+{
+	struct dasd_ccw_req *cqr;
+
+	list_for_each_entry(cqr, ccw_queue, blocklist) {
+		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
+			return 0;
+	}
+
+	return 1;
+}
+
+static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
+{
+	struct dasd_device *device;
+	struct dasd_ccw_req *cqr, *n;
+	u8 *sense = NULL;
+	int rc;
+
+retry:
+	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
+		device = cqr->startdev;
+		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
+			continue;
+
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			continue;
+		}
+		/*Non-temporary stop condition will trigger fail fast*/
+		if (device->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    !dasd_eer_enabled(device)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EAGAIN;
+			continue;
+		}
+
+		/*Don't try to start requests if device is stopped*/
+		if (interruptible) {
+			rc = wait_event_interruptible(
+				generic_waitq, !device->stopped);
+			if (rc == -ERESTARTSYS) {
+				cqr->status = DASD_CQR_FAILED;
+				cqr->intrc = rc;
+				continue;
+			}
+		} else
+			wait_event(generic_waitq, !(device->stopped));
+
+		if (!cqr->callback)
+			cqr->callback = dasd_wakeup_cb;
+		cqr->callback_data = DASD_SLEEPON_START_TAG;
+		dasd_add_request_tail(cqr);
+	}
+
+	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
+
+	rc = 0;
+	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
+		/*
+		 * In some cases the 'File Protected' or 'Incorrect Length'
+		 * error might be expected and error recovery would be
+		 * unnecessary in these cases.	Check if the according suppress
+		 * bit is set.
+		 */
+		sense = dasd_get_sense(&cqr->irb);
+		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
+		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
+			continue;
+		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
+		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
+			continue;
+
+		/*
+		 * for alias devices simplify error recovery and
+		 * return to upper layer
+		 * do not skip ERP requests
+		 */
+		if (cqr->startdev != cqr->basedev && !cqr->refers &&
+		    (cqr->status == DASD_CQR_TERMINATED ||
+		     cqr->status == DASD_CQR_NEED_ERP))
+			return -EAGAIN;
+
+		/* normal recovery for basedev IO */
+		if (__dasd_sleep_on_erp(cqr))
+			/* handle erp first */
+			goto retry;
+	}
+
+	return 0;
+}
+
+/*
+ * Queue a request to the tail of the device ccw_queue and wait for
+ * it's completion.
+ */
+int dasd_sleep_on(struct dasd_ccw_req *cqr)
+{
+	return _dasd_sleep_on(cqr, 0);
+}
+EXPORT_SYMBOL(dasd_sleep_on);
+
+/*
+ * Start requests from a ccw_queue and wait for their completion.
+ */
+int dasd_sleep_on_queue(struct list_head *ccw_queue)
+{
+	return _dasd_sleep_on_queue(ccw_queue, 0);
+}
+EXPORT_SYMBOL(dasd_sleep_on_queue);
+
+/*
+ * Queue a request to the tail of the device ccw_queue and wait
+ * interruptible for it's completion.
+ */
+int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
+{
+	return _dasd_sleep_on(cqr, 1);
+}
+EXPORT_SYMBOL(dasd_sleep_on_interruptible);
+
+/*
+ * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
+ * for eckd devices) the currently running request has to be terminated
+ * and be put back to status queued, before the special request is added
+ * to the head of the queue. Then the special request is waited on normally.
+ */
+static inline int _dasd_term_running_cqr(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+
+	if (list_empty(&device->ccw_queue))
+		return 0;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	rc = device->discipline->term_IO(cqr);
+	if (!rc)
+		/*
+		 * CQR terminated because a more important request is pending.
+		 * Undo decreasing of retry counter because this is
+		 * not an error case.
+		 */
+		cqr->retries++;
+	return rc;
+}
+
+int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+
+	device = cqr->startdev;
+	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+		cqr->status = DASD_CQR_FAILED;
+		cqr->intrc = -EPERM;
+		return -EIO;
+	}
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = _dasd_term_running_cqr(device);
+	if (rc) {
+		spin_unlock_irq(get_ccwdev_lock(device->cdev));
+		return rc;
+	}
+	cqr->callback = dasd_wakeup_cb;
+	cqr->callback_data = DASD_SLEEPON_START_TAG;
+	cqr->status = DASD_CQR_QUEUED;
+	/*
+	 * add new request as second
+	 * first the terminated cqr needs to be finished
+	 */
+	list_add(&cqr->devlist, device->ccw_queue.next);
+
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+	wait_event(generic_waitq, _wait_for_wakeup(cqr));
+
+	if (cqr->status == DASD_CQR_DONE)
+		rc = 0;
+	else if (cqr->intrc)
+		rc = cqr->intrc;
+	else
+		rc = -EIO;
+
+	/* kick tasklets */
+	dasd_schedule_device_bh(device);
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+
+	return rc;
+}
+EXPORT_SYMBOL(dasd_sleep_on_immediatly);
+
+/*
+ * Cancels a request that was started with dasd_sleep_on_req.
+ * This is useful to timeout requests. The request will be
+ * terminated if it is currently in i/o.
+ * Returns 0 if request termination was successful
+ *	   negative error code if termination failed
+ * Cancellation of a request is an asynchronous operation! The calling
+ * function has to wait until the request is properly returned via callback.
+ */
+static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device = cqr->startdev;
+	int rc = 0;
+
+	switch (cqr->status) {
+	case DASD_CQR_QUEUED:
+		/* request was not started - just set to cleared */
+		cqr->status = DASD_CQR_CLEARED;
+		break;
+	case DASD_CQR_IN_IO:
+		/* request in IO - terminate IO and release again */
+		rc = device->discipline->term_IO(cqr);
+		if (rc) {
+			dev_err(&device->cdev->dev,
+				"Cancelling request %p failed with rc=%d\n",
+				cqr, rc);
+		} else {
+			cqr->stopclk = get_tod_clock();
+		}
+		break;
+	default: /* already finished or clear pending - do nothing */
+		break;
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+
+int dasd_cancel_req(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device = cqr->startdev;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	rc = __dasd_cancel_req(cqr);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	return rc;
+}
+
+/*
+ * SECTION: Operations of the dasd_block layer.
+ */
+
+/*
+ * Timeout function for dasd_block. This is used when the block layer
+ * is waiting for something that may not come reliably, (e.g. a state
+ * change interrupt)
+ */
+static void dasd_block_timeout(struct timer_list *t)
+{
+	unsigned long flags;
+	struct dasd_block *block;
+
+	block = from_timer(block, t, timer);
+	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
+	/* re-activate request queue */
+	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
+	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
+	dasd_schedule_block_bh(block);
+	blk_mq_run_hw_queues(block->request_queue, true);
+}
+
+/*
+ * Setup timeout for a dasd_block in jiffies.
+ */
+void dasd_block_set_timer(struct dasd_block *block, int expires)
+{
+	if (expires == 0)
+		del_timer(&block->timer);
+	else
+		mod_timer(&block->timer, jiffies + expires);
+}
+EXPORT_SYMBOL(dasd_block_set_timer);
+
+/*
+ * Clear timeout for a dasd_block.
+ */
+void dasd_block_clear_timer(struct dasd_block *block)
+{
+	del_timer(&block->timer);
+}
+EXPORT_SYMBOL(dasd_block_clear_timer);
+
+/*
+ * Process finished error recovery ccw.
+ */
+static void __dasd_process_erp(struct dasd_device *device,
+			       struct dasd_ccw_req *cqr)
+{
+	dasd_erp_fn_t erp_fn;
+
+	if (cqr->status == DASD_CQR_DONE)
+		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
+	else
+		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
+	erp_fn = device->discipline->erp_postaction(cqr);
+	erp_fn(cqr);
+}
+
+static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
+{
+	struct request *req;
+	blk_status_t error = BLK_STS_OK;
+	int status;
+
+	req = (struct request *) cqr->callback_data;
+	dasd_profile_end(cqr->block, cqr, req);
+
+	status = cqr->block->base->discipline->free_cp(cqr, req);
+	if (status < 0)
+		error = errno_to_blk_status(status);
+	else if (status == 0) {
+		switch (cqr->intrc) {
+		case -EPERM:
+			error = BLK_STS_NEXUS;
+			break;
+		case -ENOLINK:
+			error = BLK_STS_TRANSPORT;
+			break;
+		case -ETIMEDOUT:
+			error = BLK_STS_TIMEOUT;
+			break;
+		default:
+			error = BLK_STS_IOERR;
+			break;
+		}
+	}
+
+	/*
+	 * We need to take care for ETIMEDOUT errors here since the
+	 * complete callback does not get called in this case.
+	 * Take care of all errors here and avoid additional code to
+	 * transfer the error value to the complete callback.
+	 */
+	if (error) {
+		blk_mq_end_request(req, error);
+		blk_mq_run_hw_queues(req->q, true);
+	} else {
+		blk_mq_complete_request(req);
+	}
+}
+
+/*
+ * Process ccw request queue.
+ */
+static void __dasd_process_block_ccw_queue(struct dasd_block *block,
+					   struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	dasd_erp_fn_t erp_fn;
+	unsigned long flags;
+	struct dasd_device *base = block->base;
+
+restart:
+	/* Process request with final status. */
+	list_for_each_safe(l, n, &block->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
+		if (cqr->status != DASD_CQR_DONE &&
+		    cqr->status != DASD_CQR_FAILED &&
+		    cqr->status != DASD_CQR_NEED_ERP &&
+		    cqr->status != DASD_CQR_TERMINATED)
+			continue;
+
+		if (cqr->status == DASD_CQR_TERMINATED) {
+			base->discipline->handle_terminated_request(cqr);
+			goto restart;
+		}
+
+		/*  Process requests that may be recovered */
+		if (cqr->status == DASD_CQR_NEED_ERP) {
+			erp_fn = base->discipline->erp_action(cqr);
+			if (IS_ERR(erp_fn(cqr)))
+				continue;
+			goto restart;
+		}
+
+		/* log sense for fatal error */
+		if (cqr->status == DASD_CQR_FAILED) {
+			dasd_log_sense(cqr, &cqr->irb);
+		}
+
+		/* First of all call extended error reporting. */
+		if (dasd_eer_enabled(base) &&
+		    cqr->status == DASD_CQR_FAILED) {
+			dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
+
+			/* restart request  */
+			cqr->status = DASD_CQR_FILLED;
+			cqr->retries = 255;
+			spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
+			dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
+			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
+					       flags);
+			goto restart;
+		}
+
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			__dasd_process_erp(base, cqr);
+			goto restart;
+		}
+
+		/* Rechain finished requests to final queue */
+		cqr->endclk = get_tod_clock();
+		list_move_tail(&cqr->blocklist, final_queue);
+	}
+}
+
+static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	dasd_schedule_block_bh(cqr->block);
+}
+
+static void __dasd_block_start_head(struct dasd_block *block)
+{
+	struct dasd_ccw_req *cqr;
+
+	if (list_empty(&block->ccw_queue))
+		return;
+	/* We allways begin with the first requests on the queue, as some
+	 * of previously started requests have to be enqueued on a
+	 * dasd_device again for error recovery.
+	 */
+	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
+		if (cqr->status != DASD_CQR_FILLED)
+			continue;
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			dasd_schedule_block_bh(block);
+			continue;
+		}
+		/* Non-temporary stop condition will trigger fail fast */
+		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    (!dasd_eer_enabled(block->base))) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENOLINK;
+			dasd_schedule_block_bh(block);
+			continue;
+		}
+		/* Don't try to start requests if device is stopped */
+		if (block->base->stopped)
+			return;
+
+		/* just a fail safe check, should not happen */
+		if (!cqr->startdev)
+			cqr->startdev = block->base;
+
+		/* make sure that the requests we submit find their way back */
+		cqr->callback = dasd_return_cqr_cb;
+
+		dasd_add_request_tail(cqr);
+	}
+}
+
+/*
+ * Central dasd_block layer routine. Takes requests from the generic
+ * block layer request queue, creates ccw requests, enqueues them on
+ * a dasd_device and processes ccw requests that have been returned.
+ */
+static void dasd_block_tasklet(unsigned long data)
+{
+	struct dasd_block *block = (struct dasd_block *) data;
+	struct list_head final_queue;
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	struct dasd_queue *dq;
+
+	atomic_set(&block->tasklet_scheduled, 0);
+	INIT_LIST_HEAD(&final_queue);
+	spin_lock_irq(&block->queue_lock);
+	/* Finish off requests on ccw queue */
+	__dasd_process_block_ccw_queue(block, &final_queue);
+	spin_unlock_irq(&block->queue_lock);
+
+	/* Now call the callback function of requests with final status */
+	list_for_each_safe(l, n, &final_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
+		dq = cqr->dq;
+		spin_lock_irq(&dq->lock);
+		list_del_init(&cqr->blocklist);
+		__dasd_cleanup_cqr(cqr);
+		spin_unlock_irq(&dq->lock);
+	}
+
+	spin_lock_irq(&block->queue_lock);
+	/* Now check if the head of the ccw queue needs to be started. */
+	__dasd_block_start_head(block);
+	spin_unlock_irq(&block->queue_lock);
+
+	if (waitqueue_active(&shutdown_waitq))
+		wake_up(&shutdown_waitq);
+	dasd_put_device(block->base);
+}
+
+static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	wake_up(&dasd_flush_wq);
+}
+
+/*
+ * Requeue a request back to the block request queue
+ * only works for block requests
+ */
+static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
+{
+	struct dasd_block *block = cqr->block;
+	struct request *req;
+
+	if (!block)
+		return -EINVAL;
+	/*
+	 * If the request is an ERP request there is nothing to requeue.
+	 * This will be done with the remaining original request.
+	 */
+	if (cqr->refers)
+		return 0;
+	spin_lock_irq(&cqr->dq->lock);
+	req = (struct request *) cqr->callback_data;
+	blk_mq_requeue_request(req, false);
+	spin_unlock_irq(&cqr->dq->lock);
+
+	return 0;
+}
+
+/*
+ * Go through all request on the dasd_block request queue, cancel them
+ * on the respective dasd_device, and return them to the generic
+ * block layer.
+ */
+static int dasd_flush_block_queue(struct dasd_block *block)
+{
+	struct dasd_ccw_req *cqr, *n;
+	int rc, i;
+	struct list_head flush_queue;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&flush_queue);
+	spin_lock_bh(&block->queue_lock);
+	rc = 0;
+restart:
+	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
+		/* if this request currently owned by a dasd_device cancel it */
+		if (cqr->status >= DASD_CQR_QUEUED)
+			rc = dasd_cancel_req(cqr);
+		if (rc < 0)
+			break;
+		/* Rechain request (including erp chain) so it won't be
+		 * touched by the dasd_block_tasklet anymore.
+		 * Replace the callback so we notice when the request
+		 * is returned from the dasd_device layer.
+		 */
+		cqr->callback = _dasd_wake_block_flush_cb;
+		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
+			list_move_tail(&cqr->blocklist, &flush_queue);
+		if (i > 1)
+			/* moved more than one request - need to restart */
+			goto restart;
+	}
+	spin_unlock_bh(&block->queue_lock);
+	/* Now call the callback function of flushed requests */
+restart_cb:
+	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
+		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_erp(block->base, cqr);
+			spin_unlock_bh(&block->queue_lock);
+			/* restart list_for_xx loop since dasd_process_erp
+			 * might remove multiple elements */
+			goto restart_cb;
+		}
+		/* call the callback function */
+		spin_lock_irqsave(&cqr->dq->lock, flags);
+		cqr->endclk = get_tod_clock();
+		list_del_init(&cqr->blocklist);
+		__dasd_cleanup_cqr(cqr);
+		spin_unlock_irqrestore(&cqr->dq->lock, flags);
+	}
+	return rc;
+}
+
+/*
+ * Schedules a call to dasd_tasklet over the device tasklet.
+ */
+void dasd_schedule_block_bh(struct dasd_block *block)
+{
+	/* Protect against rescheduling. */
+	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
+		return;
+	/* life cycle of block is bound to it's base device */
+	dasd_get_device(block->base);
+	tasklet_hi_schedule(&block->tasklet);
+}
+EXPORT_SYMBOL(dasd_schedule_block_bh);
+
+
+/*
+ * SECTION: external block device operations
+ * (request queue handling, open, release, etc.)
+ */
+
+/*
+ * Dasd request queue function. Called from ll_rw_blk.c
+ */
+static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
+				    const struct blk_mq_queue_data *qd)
+{
+	struct dasd_block *block = hctx->queue->queuedata;
+	struct dasd_queue *dq = hctx->driver_data;
+	struct request *req = qd->rq;
+	struct dasd_device *basedev;
+	struct dasd_ccw_req *cqr;
+	blk_status_t rc = BLK_STS_OK;
+
+	basedev = block->base;
+	spin_lock_irq(&dq->lock);
+	if (basedev->state < DASD_STATE_READY ||
+	    test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "device not ready for request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	/*
+	 * if device is stopped do not fetch new requests
+	 * except failfast is active which will let requests fail
+	 * immediately in __dasd_block_start_head()
+	 */
+	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "device stopped request %p", req);
+		rc = BLK_STS_RESOURCE;
+		goto out;
+	}
+
+	if (basedev->features & DASD_FEATURE_READONLY &&
+	    rq_data_dir(req) == WRITE) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "Rejecting write request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
+	    (basedev->features & DASD_FEATURE_FAILFAST ||
+	     blk_noretry_request(req))) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "Rejecting failfast request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	cqr = basedev->discipline->build_cp(basedev, block, req);
+	if (IS_ERR(cqr)) {
+		if (PTR_ERR(cqr) == -EBUSY ||
+		    PTR_ERR(cqr) == -ENOMEM ||
+		    PTR_ERR(cqr) == -EAGAIN) {
+			rc = BLK_STS_RESOURCE;
+			goto out;
+		}
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "CCW creation failed (rc=%ld) on request %p",
+			      PTR_ERR(cqr), req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+	/*
+	 *  Note: callback is set to dasd_return_cqr_cb in
+	 * __dasd_block_start_head to cover erp requests as well
+	 */
+	cqr->callback_data = req;
+	cqr->status = DASD_CQR_FILLED;
+	cqr->dq = dq;
+
+	blk_mq_start_request(req);
+	spin_lock(&block->queue_lock);
+	list_add_tail(&cqr->blocklist, &block->ccw_queue);
+	INIT_LIST_HEAD(&cqr->devlist);
+	dasd_profile_start(block, cqr, req);
+	dasd_schedule_block_bh(block);
+	spin_unlock(&block->queue_lock);
+
+out:
+	spin_unlock_irq(&dq->lock);
+	return rc;
+}
+
+/*
+ * Block timeout callback, called from the block layer
+ *
+ * Return values:
+ * BLK_EH_RESET_TIMER if the request should be left running
+ * BLK_EH_DONE if the request is handled or terminated
+ *		      by the driver.
+ */
+enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
+{
+	struct dasd_block *block = req->q->queuedata;
+	struct dasd_device *device;
+	struct dasd_ccw_req *cqr;
+	unsigned long flags;
+	int rc = 0;
+
+	cqr = blk_mq_rq_to_pdu(req);
+	if (!cqr)
+		return BLK_EH_DONE;
+
+	spin_lock_irqsave(&cqr->dq->lock, flags);
+	device = cqr->startdev ? cqr->startdev : block->base;
+	if (!device->blk_timeout) {
+		spin_unlock_irqrestore(&cqr->dq->lock, flags);
+		return BLK_EH_RESET_TIMER;
+	}
+	DBF_DEV_EVENT(DBF_WARNING, device,
+		      " dasd_times_out cqr %p status %x",
+		      cqr, cqr->status);
+
+	spin_lock(&block->queue_lock);
+	spin_lock(get_ccwdev_lock(device->cdev));
+	cqr->retries = -1;
+	cqr->intrc = -ETIMEDOUT;
+	if (cqr->status >= DASD_CQR_QUEUED) {
+		rc = __dasd_cancel_req(cqr);
+	} else if (cqr->status == DASD_CQR_FILLED ||
+		   cqr->status == DASD_CQR_NEED_ERP) {
+		cqr->status = DASD_CQR_TERMINATED;
+	} else if (cqr->status == DASD_CQR_IN_ERP) {
+		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
+
+		list_for_each_entry_safe(searchcqr, nextcqr,
+					 &block->ccw_queue, blocklist) {
+			tmpcqr = searchcqr;
+			while (tmpcqr->refers)
+				tmpcqr = tmpcqr->refers;
+			if (tmpcqr != cqr)
+				continue;
+			/* searchcqr is an ERP request for cqr */
+			searchcqr->retries = -1;
+			searchcqr->intrc = -ETIMEDOUT;
+			if (searchcqr->status >= DASD_CQR_QUEUED) {
+				rc = __dasd_cancel_req(searchcqr);
+			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
+				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
+				searchcqr->status = DASD_CQR_TERMINATED;
+				rc = 0;
+			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
+				/*
+				 * Shouldn't happen; most recent ERP
+				 * request is at the front of queue
+				 */
+				continue;
+			}
+			break;
+		}
+	}
+	spin_unlock(get_ccwdev_lock(device->cdev));
+	dasd_schedule_block_bh(block);
+	spin_unlock(&block->queue_lock);
+	spin_unlock_irqrestore(&cqr->dq->lock, flags);
+
+	return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
+}
+
+static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+			  unsigned int idx)
+{
+	struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
+
+	if (!dq)
+		return -ENOMEM;
+
+	spin_lock_init(&dq->lock);
+	hctx->driver_data = dq;
+
+	return 0;
+}
+
+static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
+{
+	kfree(hctx->driver_data);
+	hctx->driver_data = NULL;
+}
+
+static void dasd_request_done(struct request *req)
+{
+	blk_mq_end_request(req, 0);
+	blk_mq_run_hw_queues(req->q, true);
+}
+
+static struct blk_mq_ops dasd_mq_ops = {
+	.queue_rq = do_dasd_request,
+	.complete = dasd_request_done,
+	.timeout = dasd_times_out,
+	.init_hctx = dasd_init_hctx,
+	.exit_hctx = dasd_exit_hctx,
+};
+
+/*
+ * Allocate and initialize request queue and default I/O scheduler.
+ */
+static int dasd_alloc_queue(struct dasd_block *block)
+{
+	int rc;
+
+	block->tag_set.ops = &dasd_mq_ops;
+	block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
+	block->tag_set.nr_hw_queues = nr_hw_queues;
+	block->tag_set.queue_depth = queue_depth;
+	block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+	block->tag_set.numa_node = NUMA_NO_NODE;
+
+	rc = blk_mq_alloc_tag_set(&block->tag_set);
+	if (rc)
+		return rc;
+
+	block->request_queue = blk_mq_init_queue(&block->tag_set);
+	if (IS_ERR(block->request_queue))
+		return PTR_ERR(block->request_queue);
+
+	block->request_queue->queuedata = block;
+
+	return 0;
+}
+
+/*
+ * Allocate and initialize request queue.
+ */
+static void dasd_setup_queue(struct dasd_block *block)
+{
+	unsigned int logical_block_size = block->bp_block;
+	struct request_queue *q = block->request_queue;
+	unsigned int max_bytes, max_discard_sectors;
+	int max;
+
+	if (block->base->features & DASD_FEATURE_USERAW) {
+		/*
+		 * the max_blocks value for raw_track access is 256
+		 * it is higher than the native ECKD value because we
+		 * only need one ccw per track
+		 * so the max_hw_sectors are
+		 * 2048 x 512B = 1024kB = 16 tracks
+		 */
+		max = 2048;
+	} else {
+		max = block->base->discipline->max_blocks << block->s2b_shift;
+	}
+	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
+	q->limits.max_dev_sectors = max;
+	blk_queue_logical_block_size(q, logical_block_size);
+	blk_queue_max_hw_sectors(q, max);
+	blk_queue_max_segments(q, USHRT_MAX);
+	/* with page sized segments we can translate each segement into
+	 * one idaw/tidaw
+	 */
+	blk_queue_max_segment_size(q, PAGE_SIZE);
+	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
+
+	/* Only activate blocklayer discard support for devices that support it */
+	if (block->base->features & DASD_FEATURE_DISCARD) {
+		q->limits.discard_granularity = logical_block_size;
+		q->limits.discard_alignment = PAGE_SIZE;
+
+		/* Calculate max_discard_sectors and make it PAGE aligned */
+		max_bytes = USHRT_MAX * logical_block_size;
+		max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
+		max_discard_sectors = max_bytes / logical_block_size;
+
+		blk_queue_max_discard_sectors(q, max_discard_sectors);
+		blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
+		blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
+	}
+}
+
+/*
+ * Deactivate and free request queue.
+ */
+static void dasd_free_queue(struct dasd_block *block)
+{
+	if (block->request_queue) {
+		blk_cleanup_queue(block->request_queue);
+		blk_mq_free_tag_set(&block->tag_set);
+		block->request_queue = NULL;
+	}
+}
+
+static int dasd_open(struct block_device *bdev, fmode_t mode)
+{
+	struct dasd_device *base;
+	int rc;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+
+	atomic_inc(&base->block->open_count);
+	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	if (!try_module_get(base->discipline->owner)) {
+		rc = -EINVAL;
+		goto unlock;
+	}
+
+	if (dasd_probeonly) {
+		dev_info(&base->cdev->dev,
+			 "Accessing the DASD failed because it is in "
+			 "probeonly mode\n");
+		rc = -EPERM;
+		goto out;
+	}
+
+	if (base->state <= DASD_STATE_BASIC) {
+		DBF_DEV_EVENT(DBF_ERR, base, " %s",
+			      " Cannot open unrecognized device");
+		rc = -ENODEV;
+		goto out;
+	}
+
+	if ((mode & FMODE_WRITE) &&
+	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
+	     (base->features & DASD_FEATURE_READONLY))) {
+		rc = -EROFS;
+		goto out;
+	}
+
+	dasd_put_device(base);
+	return 0;
+
+out:
+	module_put(base->discipline->owner);
+unlock:
+	atomic_dec(&base->block->open_count);
+	dasd_put_device(base);
+	return rc;
+}
+
+static void dasd_release(struct gendisk *disk, fmode_t mode)
+{
+	struct dasd_device *base = dasd_device_from_gendisk(disk);
+	if (base) {
+		atomic_dec(&base->block->open_count);
+		module_put(base->discipline->owner);
+		dasd_put_device(base);
+	}
+}
+
+/*
+ * Return disk geometry.
+ */
+static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	struct dasd_device *base;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+
+	if (!base->discipline ||
+	    !base->discipline->fill_geometry) {
+		dasd_put_device(base);
+		return -EINVAL;
+	}
+	base->discipline->fill_geometry(base->block, geo);
+	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
+	dasd_put_device(base);
+	return 0;
+}
+
+const struct block_device_operations
+dasd_device_operations = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_open,
+	.release	= dasd_release,
+	.ioctl		= dasd_ioctl,
+	.compat_ioctl	= dasd_ioctl,
+	.getgeo		= dasd_getgeo,
+};
+
+/*******************************************************************************
+ * end of block device operations
+ */
+
+static void
+dasd_exit(void)
+{
+#ifdef CONFIG_PROC_FS
+	dasd_proc_exit();
+#endif
+	dasd_eer_exit();
+        if (dasd_page_cache != NULL) {
+		kmem_cache_destroy(dasd_page_cache);
+		dasd_page_cache = NULL;
+	}
+	dasd_gendisk_exit();
+	dasd_devmap_exit();
+	if (dasd_debug_area != NULL) {
+		debug_unregister(dasd_debug_area);
+		dasd_debug_area = NULL;
+	}
+	dasd_statistics_removeroot();
+}
+
+/*
+ * SECTION: common functions for ccw_driver use
+ */
+
+/*
+ * Is the device read-only?
+ * Note that this function does not report the setting of the
+ * readonly device attribute, but how it is configured in z/VM.
+ */
+int dasd_device_is_ro(struct dasd_device *device)
+{
+	struct ccw_dev_id dev_id;
+	struct diag210 diag_data;
+	int rc;
+
+	if (!MACHINE_IS_VM)
+		return 0;
+	ccw_device_get_id(device->cdev, &dev_id);
+	memset(&diag_data, 0, sizeof(diag_data));
+	diag_data.vrdcdvno = dev_id.devno;
+	diag_data.vrdclen = sizeof(diag_data);
+	rc = diag210(&diag_data);
+	if (rc == 0 || rc == 2) {
+		return diag_data.vrdcvfla & 0x80;
+	} else {
+		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
+			  dev_id.devno, rc);
+		return 0;
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_device_is_ro);
+
+static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
+{
+	struct ccw_device *cdev = data;
+	int ret;
+
+	ret = ccw_device_set_online(cdev);
+	if (ret)
+		pr_warn("%s: Setting the DASD online failed with rc=%d\n",
+			dev_name(&cdev->dev), ret);
+}
+
+/*
+ * Initial attempt at a probe function. this can be simplified once
+ * the other detection code is gone.
+ */
+int dasd_generic_probe(struct ccw_device *cdev,
+		       struct dasd_discipline *discipline)
+{
+	int ret;
+
+	ret = dasd_add_sysfs_files(cdev);
+	if (ret) {
+		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
+				"dasd_generic_probe: could not add "
+				"sysfs entries");
+		return ret;
+	}
+	cdev->handler = &dasd_int_handler;
+
+	/*
+	 * Automatically online either all dasd devices (dasd_autodetect)
+	 * or all devices specified with dasd= parameters during
+	 * initial probe.
+	 */
+	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
+	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
+		async_schedule(dasd_generic_auto_online, cdev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_probe);
+
+void dasd_generic_free_discipline(struct dasd_device *device)
+{
+	/* Forget the discipline information. */
+	if (device->discipline) {
+		if (device->discipline->uncheck_device)
+			device->discipline->uncheck_device(device);
+		module_put(device->discipline->owner);
+		device->discipline = NULL;
+	}
+	if (device->base_discipline) {
+		module_put(device->base_discipline->owner);
+		device->base_discipline = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
+
+/*
+ * This will one day be called from a global not_oper handler.
+ * It is also used by driver_unregister during module unload.
+ */
+void dasd_generic_remove(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+	struct dasd_block *block;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device)) {
+		dasd_remove_sysfs_files(cdev);
+		return;
+	}
+	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
+	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/* Already doing offline processing */
+		dasd_put_device(device);
+		dasd_remove_sysfs_files(cdev);
+		return;
+	}
+	/*
+	 * This device is removed unconditionally. Set offline
+	 * flag to prevent dasd_open from opening it while it is
+	 * no quite down yet.
+	 */
+	dasd_set_target_state(device, DASD_STATE_NEW);
+	cdev->handler = NULL;
+	/* dasd_delete_device destroys the device reference. */
+	block = device->block;
+	dasd_delete_device(device);
+	/*
+	 * life cycle of block is bound to device, so delete it after
+	 * device was safely removed
+	 */
+	if (block)
+		dasd_free_block(block);
+
+	dasd_remove_sysfs_files(cdev);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_remove);
+
+/*
+ * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
+ * the device is detected for the first time and is supposed to be used
+ * or the user has started activation through sysfs.
+ */
+int dasd_generic_set_online(struct ccw_device *cdev,
+			    struct dasd_discipline *base_discipline)
+{
+	struct dasd_discipline *discipline;
+	struct dasd_device *device;
+	int rc;
+
+	/* first online clears initial online feature flag */
+	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
+	device = dasd_create_device(cdev);
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	discipline = base_discipline;
+	if (device->features & DASD_FEATURE_USEDIAG) {
+	  	if (!dasd_diag_discipline_pointer) {
+			/* Try to load the required module. */
+			rc = request_module(DASD_DIAG_MOD);
+			if (rc) {
+				pr_warn("%s Setting the DASD online failed "
+					"because the required module %s "
+					"could not be loaded (rc=%d)\n",
+					dev_name(&cdev->dev), DASD_DIAG_MOD,
+					rc);
+				dasd_delete_device(device);
+				return -ENODEV;
+			}
+		}
+		/* Module init could have failed, so check again here after
+		 * request_module(). */
+		if (!dasd_diag_discipline_pointer) {
+			pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
+				dev_name(&cdev->dev));
+			dasd_delete_device(device);
+			return -ENODEV;
+		}
+		discipline = dasd_diag_discipline_pointer;
+	}
+	if (!try_module_get(base_discipline->owner)) {
+		dasd_delete_device(device);
+		return -EINVAL;
+	}
+	if (!try_module_get(discipline->owner)) {
+		module_put(base_discipline->owner);
+		dasd_delete_device(device);
+		return -EINVAL;
+	}
+	device->base_discipline = base_discipline;
+	device->discipline = discipline;
+
+	/* check_device will allocate block device if necessary */
+	rc = discipline->check_device(device);
+	if (rc) {
+		pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
+			dev_name(&cdev->dev), discipline->name, rc);
+		module_put(discipline->owner);
+		module_put(base_discipline->owner);
+		dasd_delete_device(device);
+		return rc;
+	}
+
+	dasd_set_target_state(device, DASD_STATE_ONLINE);
+	if (device->state <= DASD_STATE_KNOWN) {
+		pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
+			dev_name(&cdev->dev));
+		rc = -ENODEV;
+		dasd_set_target_state(device, DASD_STATE_NEW);
+		if (device->block)
+			dasd_free_block(device->block);
+		dasd_delete_device(device);
+	} else
+		pr_debug("dasd_generic device %s found\n",
+				dev_name(&cdev->dev));
+
+	wait_event(dasd_init_waitq, _wait_for_device(device));
+
+	dasd_put_device(device);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_set_online);
+
+int dasd_generic_set_offline(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+	struct dasd_block *block;
+	int max_count, open_count, rc;
+	unsigned long flags;
+
+	rc = 0;
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device)) {
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		return PTR_ERR(device);
+	}
+
+	/*
+	 * We must make sure that this device is currently not in use.
+	 * The open_count is increased for every opener, that includes
+	 * the blkdev_get in dasd_scan_partitions. We are only interested
+	 * in the other openers.
+	 */
+	if (device->block) {
+		max_count = device->block->bdev ? 0 : -1;
+		open_count = atomic_read(&device->block->open_count);
+		if (open_count > max_count) {
+			if (open_count > 0)
+				pr_warn("%s: The DASD cannot be set offline with open count %i\n",
+					dev_name(&cdev->dev), open_count);
+			else
+				pr_warn("%s: The DASD cannot be set offline while it is in use\n",
+					dev_name(&cdev->dev));
+			rc = -EBUSY;
+			goto out_err;
+		}
+	}
+
+	/*
+	 * Test if the offline processing is already running and exit if so.
+	 * If a safe offline is being processed this could only be a normal
+	 * offline that should be able to overtake the safe offline and
+	 * cancel any I/O we do not want to wait for any longer
+	 */
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
+				  &device->flags);
+		} else {
+			rc = -EBUSY;
+			goto out_err;
+		}
+	}
+	set_bit(DASD_FLAG_OFFLINE, &device->flags);
+
+	/*
+	 * if safe_offline is called set safe_offline_running flag and
+	 * clear safe_offline so that a call to normal offline
+	 * can overrun safe_offline processing
+	 */
+	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
+	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/* need to unlock here to wait for outstanding I/O */
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		/*
+		 * If we want to set the device safe offline all IO operations
+		 * should be finished before continuing the offline process
+		 * so sync bdev first and then wait for our queues to become
+		 * empty
+		 */
+		if (device->block) {
+			rc = fsync_bdev(device->block->bdev);
+			if (rc != 0)
+				goto interrupted;
+		}
+		dasd_schedule_device_bh(device);
+		rc = wait_event_interruptible(shutdown_waitq,
+					      _wait_for_empty_queues(device));
+		if (rc != 0)
+			goto interrupted;
+
+		/*
+		 * check if a normal offline process overtook the offline
+		 * processing in this case simply do nothing beside returning
+		 * that we got interrupted
+		 * otherwise mark safe offline as not running any longer and
+		 * continue with normal offline
+		 */
+		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			rc = -ERESTARTSYS;
+			goto out_err;
+		}
+		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
+	}
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	dasd_set_target_state(device, DASD_STATE_NEW);
+	/* dasd_delete_device destroys the device reference. */
+	block = device->block;
+	dasd_delete_device(device);
+	/*
+	 * life cycle of block is bound to device, so delete it after
+	 * device was safely removed
+	 */
+	if (block)
+		dasd_free_block(block);
+
+	return 0;
+
+interrupted:
+	/* interrupted by signal */
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
+	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
+out_err:
+	dasd_put_device(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
+
+int dasd_generic_last_path_gone(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+
+	dev_warn(&device->cdev->dev, "No operational channel path is left "
+		 "for the device\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
+	/* First of all call extended error reporting. */
+	dasd_eer_write(device, NULL, DASD_EER_NOPATH);
+
+	if (device->state < DASD_STATE_BASIC)
+		return 0;
+	/* Device is active. We want to keep it. */
+	list_for_each_entry(cqr, &device->ccw_queue, devlist)
+		if ((cqr->status == DASD_CQR_IN_IO) ||
+		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
+			cqr->status = DASD_CQR_QUEUED;
+			cqr->retries++;
+		}
+	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
+
+int dasd_generic_path_operational(struct dasd_device *device)
+{
+	dev_info(&device->cdev->dev, "A channel path to the device has become "
+		 "operational\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
+	if (device->stopped & DASD_UNRESUMED_PM) {
+		dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
+		dasd_restore_device(device);
+		return 1;
+	}
+	dasd_schedule_device_bh(device);
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->request_queue)
+			blk_mq_run_hw_queues(device->block->request_queue,
+					     true);
+		}
+
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
+
+int dasd_generic_notify(struct ccw_device *cdev, int event)
+{
+	struct dasd_device *device;
+	int ret;
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device))
+		return 0;
+	ret = 0;
+	switch (event) {
+	case CIO_GONE:
+	case CIO_BOXED:
+	case CIO_NO_PATH:
+		dasd_path_no_path(device);
+		ret = dasd_generic_last_path_gone(device);
+		break;
+	case CIO_OPER:
+		ret = 1;
+		if (dasd_path_get_opm(device))
+			ret = dasd_generic_path_operational(device);
+		break;
+	}
+	dasd_put_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_notify);
+
+void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
+{
+	struct dasd_device *device;
+	int chp, oldopm, hpfpm, ifccpm;
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device))
+		return;
+
+	oldopm = dasd_path_get_opm(device);
+	for (chp = 0; chp < 8; chp++) {
+		if (path_event[chp] & PE_PATH_GONE) {
+			dasd_path_notoper(device, chp);
+		}
+		if (path_event[chp] & PE_PATH_AVAILABLE) {
+			dasd_path_available(device, chp);
+			dasd_schedule_device_bh(device);
+		}
+		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
+			if (!dasd_path_is_operational(device, chp) &&
+			    !dasd_path_need_verify(device, chp)) {
+				/*
+				 * we can not establish a pathgroup on an
+				 * unavailable path, so trigger a path
+				 * verification first
+				 */
+			dasd_path_available(device, chp);
+			dasd_schedule_device_bh(device);
+			}
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "Pathgroup re-established\n");
+			if (device->discipline->kick_validate)
+				device->discipline->kick_validate(device);
+		}
+	}
+	hpfpm = dasd_path_get_hpfpm(device);
+	ifccpm = dasd_path_get_ifccpm(device);
+	if (!dasd_path_get_opm(device) && hpfpm) {
+		/*
+		 * device has no operational paths but at least one path is
+		 * disabled due to HPF errors
+		 * disable HPF at all and use the path(s) again
+		 */
+		if (device->discipline->disable_hpf)
+			device->discipline->disable_hpf(device);
+		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
+		dasd_path_set_tbvpm(device, hpfpm);
+		dasd_schedule_device_bh(device);
+		dasd_schedule_requeue(device);
+	} else if (!dasd_path_get_opm(device) && ifccpm) {
+		/*
+		 * device has no operational paths but at least one path is
+		 * disabled due to IFCC errors
+		 * trigger path verification on paths with IFCC errors
+		 */
+		dasd_path_set_tbvpm(device, ifccpm);
+		dasd_schedule_device_bh(device);
+	}
+	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
+		dev_warn(&device->cdev->dev,
+			 "No verified channel paths remain for the device\n");
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			      "%s", "last verified path gone");
+		dasd_eer_write(device, NULL, DASD_EER_NOPATH);
+		dasd_device_set_stop_bits(device,
+					  DASD_STOPPED_DC_WAIT);
+	}
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_event);
+
+int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
+{
+	if (!dasd_path_get_opm(device) && lpm) {
+		dasd_path_set_opm(device, lpm);
+		dasd_generic_path_operational(device);
+	} else
+		dasd_path_add_opm(device, lpm);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
+
+/*
+ * clear active requests and requeue them to block layer if possible
+ */
+static int dasd_generic_requeue_all_requests(struct dasd_device *device)
+{
+	struct list_head requeue_queue;
+	struct dasd_ccw_req *cqr, *n;
+	struct dasd_ccw_req *refers;
+	int rc;
+
+	INIT_LIST_HEAD(&requeue_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = 0;
+	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
+		/* Check status and move request to flush_queue */
+		if (cqr->status == DASD_CQR_IN_IO) {
+			rc = device->discipline->term_IO(cqr);
+			if (rc) {
+				/* unable to terminate requeust */
+				dev_err(&device->cdev->dev,
+					"Unable to terminate request %p "
+					"on suspend\n", cqr);
+				spin_unlock_irq(get_ccwdev_lock(device->cdev));
+				dasd_put_device(device);
+				return rc;
+			}
+		}
+		list_move_tail(&cqr->devlist, &requeue_queue);
+	}
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+	list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
+		wait_event(dasd_flush_wq,
+			   (cqr->status != DASD_CQR_CLEAR_PENDING));
+
+		/*
+		 * requeue requests to blocklayer will only work
+		 * for block device requests
+		 */
+		if (_dasd_requeue_request(cqr))
+			continue;
+
+		/* remove requests from device and block queue */
+		list_del_init(&cqr->devlist);
+		while (cqr->refers != NULL) {
+			refers = cqr->refers;
+			/* remove the request from the block queue */
+			list_del(&cqr->blocklist);
+			/* free the finished erp request */
+			dasd_free_erp_request(cqr, cqr->memdev);
+			cqr = refers;
+		}
+
+		/*
+		 * _dasd_requeue_request already checked for a valid
+		 * blockdevice, no need to check again
+		 * all erp requests (cqr->refers) have a cqr->block
+		 * pointer copy from the original cqr
+		 */
+		list_del_init(&cqr->blocklist);
+		cqr->block->base->discipline->free_cp(
+			cqr, (struct request *) cqr->callback_data);
+	}
+
+	/*
+	 * if requests remain then they are internal request
+	 * and go back to the device queue
+	 */
+	if (!list_empty(&requeue_queue)) {
+		/* move freeze_queue to start of the ccw_queue */
+		spin_lock_irq(get_ccwdev_lock(device->cdev));
+		list_splice_tail(&requeue_queue, &device->ccw_queue);
+		spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+
+static void do_requeue_requests(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  requeue_requests);
+	dasd_generic_requeue_all_requests(device);
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+	dasd_put_device(device);
+}
+
+void dasd_schedule_requeue(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_reload_device to the kernel event daemon. */
+	if (!schedule_work(&device->requeue_requests))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_schedule_requeue);
+
+int dasd_generic_pm_freeze(struct ccw_device *cdev)
+{
+	struct dasd_device *device = dasd_device_from_cdev(cdev);
+
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	/* mark device as suspended */
+	set_bit(DASD_FLAG_SUSPENDED, &device->flags);
+
+	if (device->discipline->freeze)
+		device->discipline->freeze(device);
+
+	/* disallow new I/O  */
+	dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
+
+	return dasd_generic_requeue_all_requests(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
+
+int dasd_generic_restore_device(struct ccw_device *cdev)
+{
+	struct dasd_device *device = dasd_device_from_cdev(cdev);
+	int rc = 0;
+
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	/* allow new IO again */
+	dasd_device_remove_stop_bits(device,
+				     (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
+
+	dasd_schedule_device_bh(device);
+
+	/*
+	 * call discipline restore function
+	 * if device is stopped do nothing e.g. for disconnected devices
+	 */
+	if (device->discipline->restore && !(device->stopped))
+		rc = device->discipline->restore(device);
+	if (rc || device->stopped)
+		/*
+		 * if the resume failed for the DASD we put it in
+		 * an UNRESUMED stop state
+		 */
+		device->stopped |= DASD_UNRESUMED_PM;
+
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->request_queue)
+			blk_mq_run_hw_queues(device->block->request_queue,
+					     true);
+	}
+
+	clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
+	dasd_put_device(device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
+
+static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
+						   void *rdc_buffer,
+						   int rdc_buffer_size,
+						   int magic)
+{
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	unsigned long *idaw;
+
+	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
+				   NULL);
+
+	if (IS_ERR(cqr)) {
+		/* internal error 13 - Allocating the RDC request failed*/
+		dev_err(&device->cdev->dev,
+			 "An error occurred in the DASD device driver, "
+			 "reason=%s\n", "13");
+		return cqr;
+	}
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = CCW_CMD_RDC;
+	if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
+		idaw = (unsigned long *) (cqr->data);
+		ccw->cda = (__u32)(addr_t) idaw;
+		ccw->flags = CCW_FLAG_IDA;
+		idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
+	} else {
+		ccw->cda = (__u32)(addr_t) rdc_buffer;
+		ccw->flags = 0;
+	}
+
+	ccw->count = rdc_buffer_size;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->expires = 10*HZ;
+	cqr->retries = 256;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+
+int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
+				void *rdc_buffer, int rdc_buffer_size)
+{
+	int ret;
+	struct dasd_ccw_req *cqr;
+
+	cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
+				     magic);
+	if (IS_ERR(cqr))
+		return PTR_ERR(cqr);
+
+	ret = dasd_sleep_on(cqr);
+	dasd_sfree_request(cqr, cqr->memdev);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
+
+/*
+ *   In command mode and transport mode we need to look for sense
+ *   data in different places. The sense data itself is allways
+ *   an array of 32 bytes, so we can unify the sense data access
+ *   for both modes.
+ */
+char *dasd_get_sense(struct irb *irb)
+{
+	struct tsb *tsb = NULL;
+	char *sense = NULL;
+
+	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
+		if (irb->scsw.tm.tcw)
+			tsb = tcw_get_tsb((struct tcw *)(unsigned long)
+					  irb->scsw.tm.tcw);
+		if (tsb && tsb->length == 64 && tsb->flags)
+			switch (tsb->flags & 0x07) {
+			case 1:	/* tsa_iostat */
+				sense = tsb->tsa.iostat.sense;
+				break;
+			case 2: /* tsa_ddpc */
+				sense = tsb->tsa.ddpc.sense;
+				break;
+			default:
+				/* currently we don't use interrogate data */
+				break;
+			}
+	} else if (irb->esw.esw0.erw.cons) {
+		sense = irb->ecw;
+	}
+	return sense;
+}
+EXPORT_SYMBOL_GPL(dasd_get_sense);
+
+void dasd_generic_shutdown(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device))
+		return;
+
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+
+	dasd_schedule_device_bh(device);
+
+	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
+}
+EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
+
+static int __init dasd_init(void)
+{
+	int rc;
+
+	init_waitqueue_head(&dasd_init_waitq);
+	init_waitqueue_head(&dasd_flush_wq);
+	init_waitqueue_head(&generic_waitq);
+	init_waitqueue_head(&shutdown_waitq);
+
+	/* register 'common' DASD debug area, used for all DBF_XXX calls */
+	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
+	if (dasd_debug_area == NULL) {
+		rc = -ENOMEM;
+		goto failed;
+	}
+	debug_register_view(dasd_debug_area, &debug_sprintf_view);
+	debug_set_level(dasd_debug_area, DBF_WARNING);
+
+	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
+
+	dasd_diag_discipline_pointer = NULL;
+
+	dasd_statistics_createroot();
+
+	rc = dasd_devmap_init();
+	if (rc)
+		goto failed;
+	rc = dasd_gendisk_init();
+	if (rc)
+		goto failed;
+	rc = dasd_parse();
+	if (rc)
+		goto failed;
+	rc = dasd_eer_init();
+	if (rc)
+		goto failed;
+#ifdef CONFIG_PROC_FS
+	rc = dasd_proc_init();
+	if (rc)
+		goto failed;
+#endif
+
+	return 0;
+failed:
+	pr_info("The DASD device driver could not be initialized\n");
+	dasd_exit();
+	return rc;
+}
+
+module_init(dasd_init);
+module_exit(dasd_exit);
diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c
new file mode 100644
index 000000000..ee73b0607
--- /dev/null
+++ b/drivers/s390/block/dasd_3990_erp.c
@@ -0,0 +1,2854 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Horst  Hummel    <Horst.Hummel@de.ibm.com>
+ *		    Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 2000, 2001
+ *
+ */
+
+#define KMSG_COMPONENT "dasd-eckd"
+
+#include <linux/timer.h>
+#include <asm/idals.h>
+
+#define PRINTK_HEADER "dasd_erp(3990): "
+
+#include "dasd_int.h"
+#include "dasd_eckd.h"
+
+
+struct DCTL_data {
+	unsigned char subcommand;  /* e.g Inhibit Write, Enable Write,... */
+	unsigned char modifier;	   /* Subcommand modifier */
+	unsigned short res;	   /* reserved */
+} __attribute__ ((packed));
+
+/*
+ *****************************************************************************
+ * SECTION ERP HANDLING
+ *****************************************************************************
+ */
+/*
+ *****************************************************************************
+ * 24 and 32 byte sense ERP functions
+ *****************************************************************************
+ */
+
+/*
+ * DASD_3990_ERP_CLEANUP
+ *
+ * DESCRIPTION
+ *   Removes the already build but not necessary ERP request and sets
+ *   the status of the original cqr / erp to the given (final) status
+ *
+ *  PARAMETER
+ *   erp		request to be blocked
+ *   final_status	either DASD_CQR_DONE or DASD_CQR_FAILED
+ *
+ * RETURN VALUES
+ *   cqr		original cqr
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_cleanup(struct dasd_ccw_req * erp, char final_status)
+{
+	struct dasd_ccw_req *cqr = erp->refers;
+
+	dasd_free_erp_request(erp, erp->memdev);
+	cqr->status = final_status;
+	return cqr;
+
+}				/* end dasd_3990_erp_cleanup */
+
+/*
+ * DASD_3990_ERP_BLOCK_QUEUE
+ *
+ * DESCRIPTION
+ *   Block the given device request queue to prevent from further
+ *   processing until the started timer has expired or an related
+ *   interrupt was received.
+ */
+static void dasd_3990_erp_block_queue(struct dasd_ccw_req *erp, int expires)
+{
+
+	struct dasd_device *device = erp->startdev;
+	unsigned long flags;
+
+	DBF_DEV_EVENT(DBF_INFO, device,
+		    "blocking request queue for %is", expires/HZ);
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	dasd_device_set_stop_bits(device, DASD_STOPPED_PENDING);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	erp->status = DASD_CQR_FILLED;
+	if (erp->block)
+		dasd_block_set_timer(erp->block, expires);
+	else
+		dasd_device_set_timer(device, expires);
+}
+
+/*
+ * DASD_3990_ERP_INT_REQ
+ *
+ * DESCRIPTION
+ *   Handles 'Intervention Required' error.
+ *   This means either device offline or not installed.
+ *
+ * PARAMETER
+ *   erp		current erp
+ * RETURN VALUES
+ *   erp		modified erp
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_int_req(struct dasd_ccw_req * erp)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	/* first time set initial retry counter and erp_function */
+	/* and retry once without blocking queue		 */
+	/* (this enables easier enqueing of the cqr)		 */
+	if (erp->function != dasd_3990_erp_int_req) {
+
+		erp->retries = 256;
+		erp->function = dasd_3990_erp_int_req;
+
+	} else {
+
+		/* issue a message and wait for 'device ready' interrupt */
+		dev_err(&device->cdev->dev,
+			    "is offline or not installed - "
+			    "INTERVENTION REQUIRED!!\n");
+
+		dasd_3990_erp_block_queue(erp, 60*HZ);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_int_req */
+
+/*
+ * DASD_3990_ERP_ALTERNATE_PATH
+ *
+ * DESCRIPTION
+ *   Repeat the operation on a different channel path.
+ *   If all alternate paths have been tried, the request is posted with a
+ *   permanent error.
+ *
+ *  PARAMETER
+ *   erp		pointer to the current ERP
+ *
+ * RETURN VALUES
+ *   erp		modified pointer to the ERP
+ */
+static void
+dasd_3990_erp_alternate_path(struct dasd_ccw_req * erp)
+{
+	struct dasd_device *device = erp->startdev;
+	__u8 opm;
+	unsigned long flags;
+
+	/* try alternate valid path */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	opm = ccw_device_get_path_mask(device->cdev);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	if (erp->lpm == 0)
+		erp->lpm = dasd_path_get_opm(device) &
+			~(erp->irb.esw.esw0.sublog.lpum);
+	else
+		erp->lpm &= ~(erp->irb.esw.esw0.sublog.lpum);
+
+	if ((erp->lpm & opm) != 0x00) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			    "try alternate lpm=%x (lpum=%x / opm=%x)",
+			    erp->lpm, erp->irb.esw.esw0.sublog.lpum, opm);
+
+		/* reset status to submit the request again... */
+		erp->status = DASD_CQR_FILLED;
+		erp->retries = 10;
+	} else {
+		dev_err(&device->cdev->dev,
+			"The DASD cannot be reached on any path (lpum=%x"
+			"/opm=%x)\n", erp->irb.esw.esw0.sublog.lpum, opm);
+
+		/* post request with permanent error */
+		erp->status = DASD_CQR_FAILED;
+	}
+}				/* end dasd_3990_erp_alternate_path */
+
+/*
+ * DASD_3990_ERP_DCTL
+ *
+ * DESCRIPTION
+ *   Setup cqr to do the Diagnostic Control (DCTL) command with an
+ *   Inhibit Write subcommand (0x20) and the given modifier.
+ *
+ *  PARAMETER
+ *   erp		pointer to the current (failed) ERP
+ *   modifier		subcommand modifier
+ *
+ * RETURN VALUES
+ *   dctl_cqr		pointer to NEW dctl_cqr
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_DCTL(struct dasd_ccw_req * erp, char modifier)
+{
+
+	struct dasd_device *device = erp->startdev;
+	struct DCTL_data *DCTL_data;
+	struct ccw1 *ccw;
+	struct dasd_ccw_req *dctl_cqr;
+
+	dctl_cqr = dasd_alloc_erp_request((char *) &erp->magic, 1,
+					  sizeof(struct DCTL_data),
+					  device);
+	if (IS_ERR(dctl_cqr)) {
+		dev_err(&device->cdev->dev,
+			    "Unable to allocate DCTL-CQR\n");
+		erp->status = DASD_CQR_FAILED;
+		return erp;
+	}
+
+	DCTL_data = dctl_cqr->data;
+
+	DCTL_data->subcommand = 0x02;	/* Inhibit Write */
+	DCTL_data->modifier = modifier;
+
+	ccw = dctl_cqr->cpaddr;
+	memset(ccw, 0, sizeof(struct ccw1));
+	ccw->cmd_code = CCW_CMD_DCTL;
+	ccw->count = 4;
+	ccw->cda = (__u32)(addr_t) DCTL_data;
+	dctl_cqr->flags = erp->flags;
+	dctl_cqr->function = dasd_3990_erp_DCTL;
+	dctl_cqr->refers = erp;
+	dctl_cqr->startdev = device;
+	dctl_cqr->memdev = device;
+	dctl_cqr->magic = erp->magic;
+	dctl_cqr->expires = 5 * 60 * HZ;
+	dctl_cqr->retries = 2;
+
+	dctl_cqr->buildclk = get_tod_clock();
+
+	dctl_cqr->status = DASD_CQR_FILLED;
+
+	return dctl_cqr;
+
+}				/* end dasd_3990_erp_DCTL */
+
+/*
+ * DASD_3990_ERP_ACTION_1
+ *
+ * DESCRIPTION
+ *   Setup ERP to do the ERP action 1 (see Reference manual).
+ *   Repeat the operation on a different channel path.
+ *   As deviation from the recommended recovery action, we reset the path mask
+ *   after we have tried each path and go through all paths a second time.
+ *   This will cover situations where only one path at a time is actually down,
+ *   but all paths fail and recover just with the same sequence and timing as
+ *   we try to use them (flapping links).
+ *   If all alternate paths have been tried twice, the request is posted with
+ *   a permanent error.
+ *
+ *  PARAMETER
+ *   erp		pointer to the current ERP
+ *
+ * RETURN VALUES
+ *   erp		pointer to the ERP
+ *
+ */
+static struct dasd_ccw_req *dasd_3990_erp_action_1_sec(struct dasd_ccw_req *erp)
+{
+	erp->function = dasd_3990_erp_action_1_sec;
+	dasd_3990_erp_alternate_path(erp);
+	return erp;
+}
+
+static struct dasd_ccw_req *dasd_3990_erp_action_1(struct dasd_ccw_req *erp)
+{
+	erp->function = dasd_3990_erp_action_1;
+	dasd_3990_erp_alternate_path(erp);
+	if (erp->status == DASD_CQR_FAILED &&
+	    !test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
+		erp->status = DASD_CQR_FILLED;
+		erp->retries = 10;
+		erp->lpm = dasd_path_get_opm(erp->startdev);
+		erp->function = dasd_3990_erp_action_1_sec;
+	}
+	return erp;
+}				/* end dasd_3990_erp_action_1(b) */
+
+/*
+ * DASD_3990_ERP_ACTION_4
+ *
+ * DESCRIPTION
+ *   Setup ERP to do the ERP action 4 (see Reference manual).
+ *   Set the current request to PENDING to block the CQR queue for that device
+ *   until the state change interrupt appears.
+ *   Use a timer (20 seconds) to retry the cqr if the interrupt is still
+ *   missing.
+ *
+ *  PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the current ERP
+ *
+ * RETURN VALUES
+ *   erp		pointer to the ERP
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_action_4(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	/* first time set initial retry counter and erp_function    */
+	/* and retry once without waiting for state change pending  */
+	/* interrupt (this enables easier enqueing of the cqr)	    */
+	if (erp->function != dasd_3990_erp_action_4) {
+
+		DBF_DEV_EVENT(DBF_INFO, device, "%s",
+			    "dasd_3990_erp_action_4: first time retry");
+
+		erp->retries = 256;
+		erp->function = dasd_3990_erp_action_4;
+
+	} else {
+		if (sense && (sense[25] == 0x1D)) { /* state change pending */
+
+			DBF_DEV_EVENT(DBF_INFO, device,
+				    "waiting for state change pending "
+				    "interrupt, %d retries left",
+				    erp->retries);
+
+			dasd_3990_erp_block_queue(erp, 30*HZ);
+
+		} else if (sense && (sense[25] == 0x1E)) {	/* busy */
+			DBF_DEV_EVENT(DBF_INFO, device,
+				    "busy - redriving request later, "
+				    "%d retries left",
+				    erp->retries);
+                        dasd_3990_erp_block_queue(erp, HZ);
+		} else {
+			/* no state change pending - retry */
+			DBF_DEV_EVENT(DBF_INFO, device,
+				     "redriving request immediately, "
+				     "%d retries left",
+				     erp->retries);
+			erp->status = DASD_CQR_FILLED;
+		}
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_action_4 */
+
+/*
+ *****************************************************************************
+ * 24 byte sense ERP functions (only)
+ *****************************************************************************
+ */
+
+/*
+ * DASD_3990_ERP_ACTION_5
+ *
+ * DESCRIPTION
+ *   Setup ERP to do the ERP action 5 (see Reference manual).
+ *   NOTE: Further handling is done in xxx_further_erp after the retries.
+ *
+ *  PARAMETER
+ *   erp		pointer to the current ERP
+ *
+ * RETURN VALUES
+ *   erp		pointer to the ERP
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_action_5(struct dasd_ccw_req * erp)
+{
+
+	/* first of all retry */
+	erp->retries = 10;
+	erp->function = dasd_3990_erp_action_5;
+
+	return erp;
+
+}				/* end dasd_3990_erp_action_5 */
+
+/*
+ * DASD_3990_HANDLE_ENV_DATA
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Environmental data present'.
+ *   Does a analysis of the sense data (message Format)
+ *   and prints the error messages.
+ *
+ * PARAMETER
+ *   sense		current sense data
+ *
+ * RETURN VALUES
+ *   void
+ */
+static void
+dasd_3990_handle_env_data(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+	char msg_format = (sense[7] & 0xF0);
+	char msg_no = (sense[7] & 0x0F);
+	char errorstring[ERRORLENGTH];
+
+	switch (msg_format) {
+	case 0x00:		/* Format 0 - Program or System Checks */
+
+		if (sense[1] & 0x10) {	/* check message to operator bit */
+
+			switch (msg_no) {
+			case 0x00:	/* No Message */
+				break;
+			case 0x01:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Invalid Command\n");
+				break;
+			case 0x02:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Invalid Command "
+					    "Sequence\n");
+				break;
+			case 0x03:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - CCW Count less than "
+					    "required\n");
+				break;
+			case 0x04:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Invalid Parameter\n");
+				break;
+			case 0x05:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Diagnostic of Special"
+					    " Command Violates File Mask\n");
+				break;
+			case 0x07:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Channel Returned with "
+					    "Incorrect retry CCW\n");
+				break;
+			case 0x08:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Reset Notification\n");
+				break;
+			case 0x09:
+				dev_warn(&device->cdev->dev,
+					 "FORMAT 0 - Storage Path Restart\n");
+				break;
+			case 0x0A:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Channel requested "
+					    "... %02x\n", sense[8]);
+				break;
+			case 0x0B:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Invalid Defective/"
+					    "Alternate Track Pointer\n");
+				break;
+			case 0x0C:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - DPS Installation "
+					    "Check\n");
+				break;
+			case 0x0E:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Command Invalid on "
+					    "Secondary Address\n");
+				break;
+			case 0x0F:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Status Not As "
+					    "Required: reason %02x\n",
+					 sense[8]);
+				break;
+			default:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Reserved\n");
+			}
+		} else {
+			switch (msg_no) {
+			case 0x00:	/* No Message */
+				break;
+			case 0x01:
+				dev_warn(&device->cdev->dev,
+					 "FORMAT 0 - Device Error "
+					 "Source\n");
+				break;
+			case 0x02:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Reserved\n");
+				break;
+			case 0x03:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Device Fenced - "
+					    "device = %02x\n", sense[4]);
+				break;
+			case 0x04:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Data Pinned for "
+					    "Device\n");
+				break;
+			default:
+				dev_warn(&device->cdev->dev,
+					    "FORMAT 0 - Reserved\n");
+			}
+		}
+		break;
+
+	case 0x10:		/* Format 1 - Device Equipment Checks */
+		switch (msg_no) {
+		case 0x00:	/* No Message */
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Device Status 1 not as "
+				    "expected\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Index missing\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				 "FORMAT 1 - Interruption cannot be "
+				 "reset\n");
+			break;
+		case 0x05:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Device did not respond to "
+				    "selection\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Device check-2 error or Set "
+				    "Sector is not complete\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Head address does not "
+				    "compare\n");
+			break;
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Device status 1 not valid\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Device not ready\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Track physical address did "
+				    "not compare\n");
+			break;
+		case 0x0B:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Missing device address bit\n");
+			break;
+		case 0x0C:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Drive motor switch is off\n");
+			break;
+		case 0x0D:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Seek incomplete\n");
+			break;
+		case 0x0E:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Cylinder address did not "
+				    "compare\n");
+			break;
+		case 0x0F:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Offset active cannot be "
+				    "reset\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 1 - Reserved\n");
+		}
+		break;
+
+	case 0x20:		/* Format 2 - 3990 Equipment Checks */
+		switch (msg_no) {
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 2 - 3990 check-2 error\n");
+			break;
+		case 0x0E:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 2 - Support facility errors\n");
+			break;
+		case 0x0F:
+			dev_warn(&device->cdev->dev,
+				 "FORMAT 2 - Microcode detected error "
+				 "%02x\n",
+				 sense[8]);
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 2 - Reserved\n");
+		}
+		break;
+
+	case 0x30:		/* Format 3 - 3990 Control Checks */
+		switch (msg_no) {
+		case 0x0F:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 3 - Allegiance terminated\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 3 - Reserved\n");
+		}
+		break;
+
+	case 0x40:		/* Format 4 - Data Checks */
+		switch (msg_no) {
+		case 0x00:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Home address area error\n");
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Count area error\n");
+			break;
+		case 0x02:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Key area error\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Data area error\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in home address "
+				    "area\n");
+			break;
+		case 0x05:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in count address "
+				    "area\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in key area\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in data area\n");
+			break;
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Home address area error; "
+				    "offset active\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Count area error; offset "
+				    "active\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Key area error; offset "
+				    "active\n");
+			break;
+		case 0x0B:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Data area error; "
+				    "offset active\n");
+			break;
+		case 0x0C:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in home "
+				    "address area; offset active\n");
+			break;
+		case 0x0D:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in count "
+				    "address area; offset active\n");
+			break;
+		case 0x0E:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in key area; "
+				    "offset active\n");
+			break;
+		case 0x0F:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - No sync byte in data area; "
+				    "offset active\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 4 - Reserved\n");
+		}
+		break;
+
+	case 0x50:  /* Format 5 - Data Check with displacement information */
+		switch (msg_no) {
+		case 0x00:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the "
+				    "home address area\n");
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				 "FORMAT 5 - Data Check in the count "
+				 "area\n");
+			break;
+		case 0x02:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the key area\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				 "FORMAT 5 - Data Check in the data "
+				 "area\n");
+			break;
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the "
+				    "home address area; offset active\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the count area; "
+				    "offset active\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the key area; "
+				    "offset active\n");
+			break;
+		case 0x0B:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Data Check in the data area; "
+				    "offset active\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 5 - Reserved\n");
+		}
+		break;
+
+	case 0x60:  /* Format 6 - Usage Statistics/Overrun Errors */
+		switch (msg_no) {
+		case 0x00:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel A\n");
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel B\n");
+			break;
+		case 0x02:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel C\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel D\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel E\n");
+			break;
+		case 0x05:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel F\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel G\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Overrun on channel H\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 6 - Reserved\n");
+		}
+		break;
+
+	case 0x70:  /* Format 7 - Device Connection Control Checks */
+		switch (msg_no) {
+		case 0x00:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - RCC initiated by a connection "
+				    "check alert\n");
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - RCC 1 sequence not "
+				    "successful\n");
+			break;
+		case 0x02:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - RCC 1 and RCC 2 sequences not "
+				    "successful\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Invalid tag-in during "
+				    "selection sequence\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - extra RCC required\n");
+			break;
+		case 0x05:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Invalid DCC selection "
+				    "response or timeout\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Missing end operation; device "
+				    "transfer complete\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Missing end operation; device "
+				    "transfer incomplete\n");
+			break;
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Invalid tag-in for an "
+				    "immediate command sequence\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Invalid tag-in for an "
+				    "extended command sequence\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - 3990 microcode time out when "
+				    "stopping selection\n");
+			break;
+		case 0x0B:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - No response to selection "
+				    "after a poll interruption\n");
+			break;
+		case 0x0C:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Permanent path error (DASD "
+				    "controller not available)\n");
+			break;
+		case 0x0D:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - DASD controller not available"
+				    " on disconnected command chain\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 7 - Reserved\n");
+		}
+		break;
+
+	case 0x80:  /* Format 8 - Additional Device Equipment Checks */
+		switch (msg_no) {
+		case 0x00:	/* No Message */
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - Error correction code "
+				    "hardware fault\n");
+			break;
+		case 0x03:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - Unexpected end operation "
+				    "response code\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - End operation with transfer "
+				    "count not zero\n");
+			break;
+		case 0x05:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - End operation with transfer "
+				    "count zero\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - DPS checks after a system "
+				    "reset or selective reset\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - DPS cannot be filled\n");
+			break;
+		case 0x08:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - Short busy time-out during "
+				    "device selection\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - DASD controller failed to "
+				    "set or reset the long busy latch\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - No interruption from device "
+				    "during a command chain\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 8 - Reserved\n");
+		}
+		break;
+
+	case 0x90:  /* Format 9 - Device Read, Write, and Seek Checks */
+		switch (msg_no) {
+		case 0x00:
+			break;	/* No Message */
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 9 - Device check-2 error\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				 "FORMAT 9 - Head address did not "
+				 "compare\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 9 - Track physical address did "
+				    "not compare while oriented\n");
+			break;
+		case 0x0E:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 9 - Cylinder address did not "
+				    "compare\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT 9 - Reserved\n");
+		}
+		break;
+
+	case 0xF0:		/* Format F - Cache Storage Checks */
+		switch (msg_no) {
+		case 0x00:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Operation Terminated\n");
+			break;
+		case 0x01:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Subsystem Processing Error\n");
+			break;
+		case 0x02:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Cache or nonvolatile storage "
+				    "equipment failure\n");
+			break;
+		case 0x04:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Caching terminated\n");
+			break;
+		case 0x06:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Cache fast write access not "
+				    "authorized\n");
+			break;
+		case 0x07:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Track format incorrect\n");
+			break;
+		case 0x09:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Caching reinitiated\n");
+			break;
+		case 0x0A:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Nonvolatile storage "
+				    "terminated\n");
+			break;
+		case 0x0B:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Volume is suspended duplex\n");
+			/* call extended error reporting (EER) */
+			dasd_eer_write(device, erp->refers,
+				       DASD_EER_PPRCSUSPEND);
+			break;
+		case 0x0C:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Subsystem status cannot be "
+				    "determined\n");
+			break;
+		case 0x0D:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Caching status reset to "
+				    "default\n");
+			break;
+		case 0x0E:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - DASD Fast Write inhibited\n");
+			break;
+		default:
+			dev_warn(&device->cdev->dev,
+				    "FORMAT F - Reserved\n");
+		}
+		break;
+
+	default:	/* unknown message format - should not happen
+			   internal error 03 - unknown message format */
+		snprintf(errorstring, ERRORLENGTH, "03 %x02", msg_format);
+		dev_err(&device->cdev->dev,
+			 "An error occurred in the DASD device driver, "
+			 "reason=%s\n", errorstring);
+		break;
+	}			/* end switch message format */
+
+}				/* end dasd_3990_handle_env_data */
+
+/*
+ * DASD_3990_ERP_COM_REJ
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Command Reject' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ *   sense		current sense data
+ *
+ * RETURN VALUES
+ *   erp		'new' erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_com_rej(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_com_rej;
+
+	/* env data present (ACTION 10 - retry should work) */
+	if (sense[2] & SNS2_ENV_DATA_PRESENT) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Command Reject - environmental data present");
+
+		dasd_3990_handle_env_data(erp, sense);
+
+		erp->retries = 5;
+
+	} else if (sense[1] & SNS1_WRITE_INHIBITED) {
+		dev_err(&device->cdev->dev, "An I/O request was rejected"
+			" because writing is inhibited\n");
+		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+	} else {
+		/* fatal error -  set status to FAILED
+		   internal error 09 - Command Reject */
+		if (!test_bit(DASD_CQR_SUPPRESS_CR, &erp->flags))
+			dev_err(&device->cdev->dev,
+				"An error occurred in the DASD device driver, reason=09\n");
+
+		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_com_rej */
+
+/*
+ * DASD_3990_ERP_BUS_OUT
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Bus Out Parity Check' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_bus_out(struct dasd_ccw_req * erp)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	/* first time set initial retry counter and erp_function */
+	/* and retry once without blocking queue		 */
+	/* (this enables easier enqueing of the cqr)		 */
+	if (erp->function != dasd_3990_erp_bus_out) {
+		erp->retries = 256;
+		erp->function = dasd_3990_erp_bus_out;
+
+	} else {
+
+		/* issue a message and wait for 'device ready' interrupt */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "bus out parity error or BOPC requested by "
+			    "channel");
+
+		dasd_3990_erp_block_queue(erp, 60*HZ);
+
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_bus_out */
+
+/*
+ * DASD_3990_ERP_EQUIP_CHECK
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Equipment Check' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_equip_check(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_equip_check;
+
+	if (sense[1] & SNS1_WRITE_INHIBITED) {
+		dev_info(&device->cdev->dev,
+			    "Write inhibited path encountered\n");
+
+		/* vary path offline
+		   internal error 04 - Path should be varied off-line.*/
+		dev_err(&device->cdev->dev, "An error occurred in the DASD "
+			"device driver, reason=%s\n", "04");
+
+		erp = dasd_3990_erp_action_1(erp);
+
+	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Equipment Check - " "environmental data present");
+
+		dasd_3990_handle_env_data(erp, sense);
+
+		erp = dasd_3990_erp_action_4(erp, sense);
+
+	} else if (sense[1] & SNS1_PERM_ERR) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Equipment Check - retry exhausted or "
+			    "undesirable");
+
+		erp = dasd_3990_erp_action_1(erp);
+
+	} else {
+		/* all other equipment checks - Action 5 */
+		/* rest is done when retries == 0 */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Equipment check or processing error");
+
+		erp = dasd_3990_erp_action_5(erp);
+	}
+	return erp;
+
+}				/* end dasd_3990_erp_equip_check */
+
+/*
+ * DASD_3990_ERP_DATA_CHECK
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Data Check' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_data_check(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_data_check;
+
+	if (sense[2] & SNS2_CORRECTABLE) {	/* correctable data check */
+
+		/* issue message that the data has been corrected */
+		dev_emerg(&device->cdev->dev,
+			    "Data recovered during retry with PCI "
+			    "fetch mode active\n");
+
+		/* not possible to handle this situation in Linux */
+		panic("No way to inform application about the possibly "
+		      "incorrect data");
+
+	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Uncorrectable data check recovered secondary "
+			    "addr of duplex pair");
+
+		erp = dasd_3990_erp_action_4(erp, sense);
+
+	} else if (sense[1] & SNS1_PERM_ERR) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Uncorrectable data check with internal "
+			    "retry exhausted");
+
+		erp = dasd_3990_erp_action_1(erp);
+
+	} else {
+		/* all other data checks */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Uncorrectable data check with retry count "
+			    "exhausted...");
+
+		erp = dasd_3990_erp_action_5(erp);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_data_check */
+
+/*
+ * DASD_3990_ERP_OVERRUN
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Overrun' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_overrun(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_overrun;
+
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+		    "Overrun - service overrun or overrun"
+		    " error requested by channel");
+
+	erp = dasd_3990_erp_action_5(erp);
+
+	return erp;
+
+}				/* end dasd_3990_erp_overrun */
+
+/*
+ * DASD_3990_ERP_INV_FORMAT
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Invalid Track Format' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_inv_format(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_inv_format;
+
+	if (sense[2] & SNS2_ENV_DATA_PRESENT) {
+
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Track format error when destaging or "
+			    "staging data");
+
+		dasd_3990_handle_env_data(erp, sense);
+
+		erp = dasd_3990_erp_action_4(erp, sense);
+
+	} else {
+		/* internal error 06 - The track format is not valid*/
+		dev_err(&device->cdev->dev,
+			"An error occurred in the DASD device driver, "
+			"reason=%s\n", "06");
+
+		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_inv_format */
+
+/*
+ * DASD_3990_ERP_EOC
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'End-of-Cylinder' error.
+ *
+ * PARAMETER
+ *   erp		already added default erp
+ * RETURN VALUES
+ *   erp		pointer to original (failed) cqr.
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_EOC(struct dasd_ccw_req * default_erp, char *sense)
+{
+
+	struct dasd_device *device = default_erp->startdev;
+
+	dev_err(&device->cdev->dev,
+		"The cylinder data for accessing the DASD is inconsistent\n");
+
+	/* implement action 7 - BUG */
+	return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
+
+}				/* end dasd_3990_erp_EOC */
+
+/*
+ * DASD_3990_ERP_ENV_DATA
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'Environmental-Data Present' error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_env_data(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_env_data;
+
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "Environmental data present");
+
+	dasd_3990_handle_env_data(erp, sense);
+
+	/* don't retry on disabled interface */
+	if (sense[7] != 0x0F) {
+		erp = dasd_3990_erp_action_4(erp, sense);
+	} else {
+		erp->status = DASD_CQR_FILLED;
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_env_data */
+
+/*
+ * DASD_3990_ERP_NO_REC
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'No Record Found' error.
+ *
+ * PARAMETER
+ *   erp		already added default ERP
+ *
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_no_rec(struct dasd_ccw_req * default_erp, char *sense)
+{
+
+	struct dasd_device *device = default_erp->startdev;
+
+	/*
+	 * In some cases the 'No Record Found' error might be expected and
+	 * log messages shouldn't be written then.
+	 * Check if the according suppress bit is set.
+	 */
+	if (!test_bit(DASD_CQR_SUPPRESS_NRF, &default_erp->flags))
+		dev_err(&device->cdev->dev,
+			"The specified record was not found\n");
+
+	return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
+
+}				/* end dasd_3990_erp_no_rec */
+
+/*
+ * DASD_3990_ERP_FILE_PROT
+ *
+ * DESCRIPTION
+ *   Handles 24 byte 'File Protected' error.
+ *   Note: Seek related recovery is not implemented because
+ *	   wee don't use the seek command yet.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ * RETURN VALUES
+ *   erp		new erp_head - pointer to new ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_file_prot(struct dasd_ccw_req * erp)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	/*
+	 * In some cases the 'File Protected' error might be expected and
+	 * log messages shouldn't be written then.
+	 * Check if the according suppress bit is set.
+	 */
+	if (!test_bit(DASD_CQR_SUPPRESS_FP, &erp->flags))
+		dev_err(&device->cdev->dev,
+			"Accessing the DASD failed because of a hardware error\n");
+
+	return dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+
+}				/* end dasd_3990_erp_file_prot */
+
+/*
+ * DASD_3990_ERP_INSPECT_ALIAS
+ *
+ * DESCRIPTION
+ *   Checks if the original request was started on an alias device.
+ *   If yes, it modifies the original and the erp request so that
+ *   the erp request can be started on a base device.
+ *
+ * PARAMETER
+ *   erp		pointer to the currently created default ERP
+ *
+ * RETURN VALUES
+ *   erp		pointer to the modified ERP, or NULL
+ */
+
+static struct dasd_ccw_req *dasd_3990_erp_inspect_alias(
+						struct dasd_ccw_req *erp)
+{
+	struct dasd_ccw_req *cqr = erp->refers;
+	char *sense;
+
+	if (cqr->block &&
+	    (cqr->block->base != cqr->startdev)) {
+
+		sense = dasd_get_sense(&erp->refers->irb);
+		/*
+		 * dynamic pav may have changed base alias mapping
+		 */
+		if (!test_bit(DASD_FLAG_OFFLINE, &cqr->startdev->flags) && sense
+		    && (sense[0] == 0x10) && (sense[7] == 0x0F)
+		    && (sense[8] == 0x67)) {
+			/*
+			 * remove device from alias handling to prevent new
+			 * requests from being scheduled on the
+			 * wrong alias device
+			 */
+			dasd_alias_remove_device(cqr->startdev);
+
+			/* schedule worker to reload device */
+			dasd_reload_device(cqr->startdev);
+		}
+
+		if (cqr->startdev->features & DASD_FEATURE_ERPLOG) {
+			DBF_DEV_EVENT(DBF_ERR, cqr->startdev,
+				    "ERP on alias device for request %p,"
+				    " recover on base device %s", cqr,
+				    dev_name(&cqr->block->base->cdev->dev));
+		}
+		dasd_eckd_reset_ccw_to_base_io(cqr);
+		erp->startdev = cqr->block->base;
+		erp->function = dasd_3990_erp_inspect_alias;
+		return erp;
+	} else
+		return NULL;
+}
+
+
+/*
+ * DASD_3990_ERP_INSPECT_24
+ *
+ * DESCRIPTION
+ *   Does a detailed inspection of the 24 byte sense data
+ *   and sets up a related error recovery action.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created default ERP
+ *
+ * RETURN VALUES
+ *   erp		pointer to the (addtitional) ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_inspect_24(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_ccw_req *erp_filled = NULL;
+
+	/* Check sense for ....	   */
+	/* 'Command Reject'	   */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_CMD_REJECT)) {
+		erp_filled = dasd_3990_erp_com_rej(erp, sense);
+	}
+	/* 'Intervention Required' */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_INTERVENTION_REQ)) {
+		erp_filled = dasd_3990_erp_int_req(erp);
+	}
+	/* 'Bus Out Parity Check'  */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_BUS_OUT_CHECK)) {
+		erp_filled = dasd_3990_erp_bus_out(erp);
+	}
+	/* 'Equipment Check'	   */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_EQUIPMENT_CHECK)) {
+		erp_filled = dasd_3990_erp_equip_check(erp, sense);
+	}
+	/* 'Data Check'		   */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_DATA_CHECK)) {
+		erp_filled = dasd_3990_erp_data_check(erp, sense);
+	}
+	/* 'Overrun'		   */
+	if ((erp_filled == NULL) && (sense[0] & SNS0_OVERRUN)) {
+		erp_filled = dasd_3990_erp_overrun(erp, sense);
+	}
+	/* 'Invalid Track Format'  */
+	if ((erp_filled == NULL) && (sense[1] & SNS1_INV_TRACK_FORMAT)) {
+		erp_filled = dasd_3990_erp_inv_format(erp, sense);
+	}
+	/* 'End-of-Cylinder'	   */
+	if ((erp_filled == NULL) && (sense[1] & SNS1_EOC)) {
+		erp_filled = dasd_3990_erp_EOC(erp, sense);
+	}
+	/* 'Environmental Data'	   */
+	if ((erp_filled == NULL) && (sense[2] & SNS2_ENV_DATA_PRESENT)) {
+		erp_filled = dasd_3990_erp_env_data(erp, sense);
+	}
+	/* 'No Record Found'	   */
+	if ((erp_filled == NULL) && (sense[1] & SNS1_NO_REC_FOUND)) {
+		erp_filled = dasd_3990_erp_no_rec(erp, sense);
+	}
+	/* 'File Protected'	   */
+	if ((erp_filled == NULL) && (sense[1] & SNS1_FILE_PROTECTED)) {
+		erp_filled = dasd_3990_erp_file_prot(erp);
+	}
+	/* other (unknown) error - do default ERP */
+	if (erp_filled == NULL) {
+
+		erp_filled = erp;
+	}
+
+	return erp_filled;
+
+}				/* END dasd_3990_erp_inspect_24 */
+
+/*
+ *****************************************************************************
+ * 32 byte sense ERP functions (only)
+ *****************************************************************************
+ */
+
+/*
+ * DASD_3990_ERPACTION_10_32
+ *
+ * DESCRIPTION
+ *   Handles 32 byte 'Action 10' of Single Program Action Codes.
+ *   Just retry and if retry doesn't work, return with error.
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ *   sense		current sense data
+ * RETURN VALUES
+ *   erp		modified erp_head
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_action_10_32(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->retries = 256;
+	erp->function = dasd_3990_erp_action_10_32;
+
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "Perform logging requested");
+
+	return erp;
+
+}				/* end dasd_3990_erp_action_10_32 */
+
+/*
+ * DASD_3990_ERP_ACTION_1B_32
+ *
+ * DESCRIPTION
+ *   Handles 32 byte 'Action 1B' of Single Program Action Codes.
+ *   A write operation could not be finished because of an unexpected
+ *   condition.
+ *   The already created 'default erp' is used to get the link to
+ *   the erp chain, but it can not be used for this recovery
+ *   action because it contains no DE/LO data space.
+ *
+ * PARAMETER
+ *   default_erp	already added default erp.
+ *   sense		current sense data
+ *
+ * RETURN VALUES
+ *   erp		new erp or
+ *			default_erp in case of imprecise ending or error
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_action_1B_32(struct dasd_ccw_req * default_erp, char *sense)
+{
+
+	struct dasd_device *device = default_erp->startdev;
+	__u32 cpa = 0;
+	struct dasd_ccw_req *cqr;
+	struct dasd_ccw_req *erp;
+	struct DE_eckd_data *DE_data;
+	struct PFX_eckd_data *PFX_data;
+	char *LO_data;		/* LO_eckd_data_t */
+	struct ccw1 *ccw, *oldccw;
+
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+		    "Write not finished because of unexpected condition");
+
+	default_erp->function = dasd_3990_erp_action_1B_32;
+
+	/* determine the original cqr */
+	cqr = default_erp;
+
+	while (cqr->refers != NULL) {
+		cqr = cqr->refers;
+	}
+
+	if (scsw_is_tm(&cqr->irb.scsw)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "32 bit sense, action 1B is not defined"
+			      " in transport mode - just retry");
+		return default_erp;
+	}
+
+	/* for imprecise ending just do default erp */
+	if (sense[1] & 0x01) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Imprecise ending is set - just retry");
+
+		return default_erp;
+	}
+
+	/* determine the address of the CCW to be restarted */
+	/* Imprecise ending is not set -> addr from IRB-SCSW */
+	cpa = default_erp->refers->irb.scsw.cmd.cpa;
+
+	if (cpa == 0) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Unable to determine address of the CCW "
+			    "to be restarted");
+
+		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
+	}
+
+	/* Build new ERP request including DE/LO */
+	erp = dasd_alloc_erp_request((char *) &cqr->magic,
+				     2 + 1,/* DE/LO + TIC */
+				     sizeof(struct DE_eckd_data) +
+				     sizeof(struct LO_eckd_data), device);
+
+	if (IS_ERR(erp)) {
+		/* internal error 01 - Unable to allocate ERP */
+		dev_err(&device->cdev->dev, "An error occurred in the DASD "
+			"device driver, reason=%s\n", "01");
+		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
+	}
+
+	/* use original DE */
+	DE_data = erp->data;
+	oldccw = cqr->cpaddr;
+	if (oldccw->cmd_code == DASD_ECKD_CCW_PFX) {
+		PFX_data = cqr->data;
+		memcpy(DE_data, &PFX_data->define_extent,
+		       sizeof(struct DE_eckd_data));
+	} else
+		memcpy(DE_data, cqr->data, sizeof(struct DE_eckd_data));
+
+	/* create LO */
+	LO_data = erp->data + sizeof(struct DE_eckd_data);
+
+	if ((sense[3] == 0x01) && (LO_data[1] & 0x01)) {
+		/* should not */
+		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
+	}
+
+	if ((sense[7] & 0x3F) == 0x01) {
+		/* operation code is WRITE DATA -> data area orientation */
+		LO_data[0] = 0x81;
+
+	} else if ((sense[7] & 0x3F) == 0x03) {
+		/* operation code is FORMAT WRITE -> index orientation */
+		LO_data[0] = 0xC3;
+
+	} else {
+		LO_data[0] = sense[7];	/* operation */
+	}
+
+	LO_data[1] = sense[8];	/* auxiliary */
+	LO_data[2] = sense[9];
+	LO_data[3] = sense[3];	/* count */
+	LO_data[4] = sense[29];	/* seek_addr.cyl */
+	LO_data[5] = sense[30];	/* seek_addr.cyl 2nd byte */
+	LO_data[7] = sense[31];	/* seek_addr.head 2nd byte */
+
+	memcpy(&(LO_data[8]), &(sense[11]), 8);
+
+	/* create DE ccw */
+	ccw = erp->cpaddr;
+	memset(ccw, 0, sizeof(struct ccw1));
+	ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
+	ccw->flags = CCW_FLAG_CC;
+	ccw->count = 16;
+	ccw->cda = (__u32)(addr_t) DE_data;
+
+	/* create LO ccw */
+	ccw++;
+	memset(ccw, 0, sizeof(struct ccw1));
+	ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
+	ccw->flags = CCW_FLAG_CC;
+	ccw->count = 16;
+	ccw->cda = (__u32)(addr_t) LO_data;
+
+	/* TIC to the failed ccw */
+	ccw++;
+	ccw->cmd_code = CCW_CMD_TIC;
+	ccw->cda = cpa;
+
+	/* fill erp related fields */
+	erp->flags = default_erp->flags;
+	erp->function = dasd_3990_erp_action_1B_32;
+	erp->refers = default_erp->refers;
+	erp->startdev = device;
+	erp->memdev = device;
+	erp->magic = default_erp->magic;
+	erp->expires = default_erp->expires;
+	erp->retries = 256;
+	erp->buildclk = get_tod_clock();
+	erp->status = DASD_CQR_FILLED;
+
+	/* remove the default erp */
+	dasd_free_erp_request(default_erp, device);
+
+	return erp;
+
+}				/* end dasd_3990_erp_action_1B_32 */
+
+/*
+ * DASD_3990_UPDATE_1B
+ *
+ * DESCRIPTION
+ *   Handles the update to the 32 byte 'Action 1B' of Single Program
+ *   Action Codes in case the first action was not successful.
+ *   The already created 'previous_erp' is the currently not successful
+ *   ERP.
+ *
+ * PARAMETER
+ *   previous_erp	already created previous erp.
+ *   sense		current sense data
+ * RETURN VALUES
+ *   erp		modified erp
+ */
+static struct dasd_ccw_req *
+dasd_3990_update_1B(struct dasd_ccw_req * previous_erp, char *sense)
+{
+
+	struct dasd_device *device = previous_erp->startdev;
+	__u32 cpa = 0;
+	struct dasd_ccw_req *cqr;
+	struct dasd_ccw_req *erp;
+	char *LO_data;		/* struct LO_eckd_data */
+	struct ccw1 *ccw;
+
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+		    "Write not finished because of unexpected condition"
+		    " - follow on");
+
+	/* determine the original cqr */
+	cqr = previous_erp;
+
+	while (cqr->refers != NULL) {
+		cqr = cqr->refers;
+	}
+
+	if (scsw_is_tm(&cqr->irb.scsw)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "32 bit sense, action 1B, update,"
+			      " in transport mode - just retry");
+		return previous_erp;
+	}
+
+	/* for imprecise ending just do default erp */
+	if (sense[1] & 0x01) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Imprecise ending is set - just retry");
+
+		previous_erp->status = DASD_CQR_FILLED;
+
+		return previous_erp;
+	}
+
+	/* determine the address of the CCW to be restarted */
+	/* Imprecise ending is not set -> addr from IRB-SCSW */
+	cpa = previous_erp->irb.scsw.cmd.cpa;
+
+	if (cpa == 0) {
+		/* internal error 02 -
+		   Unable to determine address of the CCW to be restarted */
+		dev_err(&device->cdev->dev, "An error occurred in the DASD "
+			"device driver, reason=%s\n", "02");
+
+		previous_erp->status = DASD_CQR_FAILED;
+
+		return previous_erp;
+	}
+
+	erp = previous_erp;
+
+	/* update the LO with the new returned sense data  */
+	LO_data = erp->data + sizeof(struct DE_eckd_data);
+
+	if ((sense[3] == 0x01) && (LO_data[1] & 0x01)) {
+		/* should not happen */
+		previous_erp->status = DASD_CQR_FAILED;
+
+		return previous_erp;
+	}
+
+	if ((sense[7] & 0x3F) == 0x01) {
+		/* operation code is WRITE DATA -> data area orientation */
+		LO_data[0] = 0x81;
+
+	} else if ((sense[7] & 0x3F) == 0x03) {
+		/* operation code is FORMAT WRITE -> index orientation */
+		LO_data[0] = 0xC3;
+
+	} else {
+		LO_data[0] = sense[7];	/* operation */
+	}
+
+	LO_data[1] = sense[8];	/* auxiliary */
+	LO_data[2] = sense[9];
+	LO_data[3] = sense[3];	/* count */
+	LO_data[4] = sense[29];	/* seek_addr.cyl */
+	LO_data[5] = sense[30];	/* seek_addr.cyl 2nd byte */
+	LO_data[7] = sense[31];	/* seek_addr.head 2nd byte */
+
+	memcpy(&(LO_data[8]), &(sense[11]), 8);
+
+	/* TIC to the failed ccw */
+	ccw = erp->cpaddr;	/* addr of DE ccw */
+	ccw++;			/* addr of LE ccw */
+	ccw++;			/* addr of TIC ccw */
+	ccw->cda = cpa;
+
+	erp->status = DASD_CQR_FILLED;
+
+	return erp;
+
+}				/* end dasd_3990_update_1B */
+
+/*
+ * DASD_3990_ERP_COMPOUND_RETRY
+ *
+ * DESCRIPTION
+ *   Handles the compound ERP action retry code.
+ *   NOTE: At least one retry is done even if zero is specified
+ *	   by the sense data. This makes enqueueing of the request
+ *	   easier.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created ERP
+ *
+ * RETURN VALUES
+ *   erp		modified ERP pointer
+ *
+ */
+static void
+dasd_3990_erp_compound_retry(struct dasd_ccw_req * erp, char *sense)
+{
+
+	switch (sense[25] & 0x03) {
+	case 0x00:		/* no not retry */
+		erp->retries = 1;
+		break;
+
+	case 0x01:		/* retry 2 times */
+		erp->retries = 2;
+		break;
+
+	case 0x02:		/* retry 10 times */
+		erp->retries = 10;
+		break;
+
+	case 0x03:		/* retry 256 times */
+		erp->retries = 256;
+		break;
+
+	default:
+		BUG();
+	}
+
+	erp->function = dasd_3990_erp_compound_retry;
+
+}				/* end dasd_3990_erp_compound_retry */
+
+/*
+ * DASD_3990_ERP_COMPOUND_PATH
+ *
+ * DESCRIPTION
+ *   Handles the compound ERP action for retry on alternate
+ *   channel path.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created ERP
+ *
+ * RETURN VALUES
+ *   erp		modified ERP pointer
+ *
+ */
+static void
+dasd_3990_erp_compound_path(struct dasd_ccw_req * erp, char *sense)
+{
+	if (sense[25] & DASD_SENSE_BIT_3) {
+		dasd_3990_erp_alternate_path(erp);
+
+		if (erp->status == DASD_CQR_FAILED &&
+		    !test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
+			/* reset the lpm and the status to be able to
+			 * try further actions. */
+			erp->lpm = dasd_path_get_opm(erp->startdev);
+			erp->status = DASD_CQR_NEED_ERP;
+		}
+	}
+
+	erp->function = dasd_3990_erp_compound_path;
+
+}				/* end dasd_3990_erp_compound_path */
+
+/*
+ * DASD_3990_ERP_COMPOUND_CODE
+ *
+ * DESCRIPTION
+ *   Handles the compound ERP action for retry code.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created ERP
+ *
+ * RETURN VALUES
+ *   erp		NEW ERP pointer
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_compound_code(struct dasd_ccw_req * erp, char *sense)
+{
+
+	if (sense[25] & DASD_SENSE_BIT_2) {
+
+		switch (sense[28]) {
+		case 0x17:
+			/* issue a Diagnostic Control command with an
+			 * Inhibit Write subcommand and controller modifier */
+			erp = dasd_3990_erp_DCTL(erp, 0x20);
+			break;
+
+		case 0x25:
+			/* wait for 5 seconds and retry again */
+			erp->retries = 1;
+
+			dasd_3990_erp_block_queue (erp, 5*HZ);
+			break;
+
+		default:
+			/* should not happen - continue */
+			break;
+		}
+	}
+
+	erp->function = dasd_3990_erp_compound_code;
+
+	return erp;
+
+}				/* end dasd_3990_erp_compound_code */
+
+/*
+ * DASD_3990_ERP_COMPOUND_CONFIG
+ *
+ * DESCRIPTION
+ *   Handles the compound ERP action for configruation
+ *   dependent error.
+ *   Note: duplex handling is not implemented (yet).
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created ERP
+ *
+ * RETURN VALUES
+ *   erp		modified ERP pointer
+ *
+ */
+static void
+dasd_3990_erp_compound_config(struct dasd_ccw_req * erp, char *sense)
+{
+
+	if ((sense[25] & DASD_SENSE_BIT_1) && (sense[26] & DASD_SENSE_BIT_2)) {
+
+		/* set to suspended duplex state then restart
+		   internal error 05 - Set device to suspended duplex state
+		   should be done */
+		struct dasd_device *device = erp->startdev;
+		dev_err(&device->cdev->dev,
+			"An error occurred in the DASD device driver, "
+			"reason=%s\n", "05");
+
+	}
+
+	erp->function = dasd_3990_erp_compound_config;
+
+}				/* end dasd_3990_erp_compound_config */
+
+/*
+ * DASD_3990_ERP_COMPOUND
+ *
+ * DESCRIPTION
+ *   Does the further compound program action if
+ *   compound retry was not successful.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the current (failed) ERP
+ *
+ * RETURN VALUES
+ *   erp		(additional) ERP pointer
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_compound(struct dasd_ccw_req * erp, char *sense)
+{
+
+	if ((erp->function == dasd_3990_erp_compound_retry) &&
+	    (erp->status == DASD_CQR_NEED_ERP)) {
+
+		dasd_3990_erp_compound_path(erp, sense);
+	}
+
+	if ((erp->function == dasd_3990_erp_compound_path) &&
+	    (erp->status == DASD_CQR_NEED_ERP)) {
+
+		erp = dasd_3990_erp_compound_code(erp, sense);
+	}
+
+	if ((erp->function == dasd_3990_erp_compound_code) &&
+	    (erp->status == DASD_CQR_NEED_ERP)) {
+
+		dasd_3990_erp_compound_config(erp, sense);
+	}
+
+	/* if no compound action ERP specified, the request failed */
+	if (erp->status == DASD_CQR_NEED_ERP)
+		erp->status = DASD_CQR_FAILED;
+
+	return erp;
+
+}				/* end dasd_3990_erp_compound */
+
+/*
+ *DASD_3990_ERP_HANDLE_SIM
+ *
+ *DESCRIPTION
+ *  inspects the SIM SENSE data and starts an appropriate action
+ *
+ * PARAMETER
+ *   sense	   sense data of the actual error
+ *
+ * RETURN VALUES
+ *   none
+ */
+void
+dasd_3990_erp_handle_sim(struct dasd_device *device, char *sense)
+{
+	/* print message according to log or message to operator mode */
+	if ((sense[24] & DASD_SIM_MSG_TO_OP) || (sense[1] & 0x10)) {
+		/* print SIM SRC from RefCode */
+		dev_err(&device->cdev->dev, "SIM - SRC: "
+			    "%02x%02x%02x%02x\n", sense[22],
+			    sense[23], sense[11], sense[12]);
+	} else if (sense[24] & DASD_SIM_LOG) {
+		/* print SIM SRC Refcode */
+		dev_warn(&device->cdev->dev, "log SIM - SRC: "
+			    "%02x%02x%02x%02x\n", sense[22],
+			    sense[23], sense[11], sense[12]);
+	}
+}
+
+/*
+ * DASD_3990_ERP_INSPECT_32
+ *
+ * DESCRIPTION
+ *   Does a detailed inspection of the 32 byte sense data
+ *   and sets up a related error recovery action.
+ *
+ * PARAMETER
+ *   sense		sense data of the actual error
+ *   erp		pointer to the currently created default ERP
+ *
+ * RETURN VALUES
+ *   erp_filled		pointer to the ERP
+ *
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_inspect_32(struct dasd_ccw_req * erp, char *sense)
+{
+
+	struct dasd_device *device = erp->startdev;
+
+	erp->function = dasd_3990_erp_inspect_32;
+
+	/* check for SIM sense data */
+	if ((sense[6] & DASD_SIM_SENSE) == DASD_SIM_SENSE)
+		dasd_3990_erp_handle_sim(device, sense);
+
+	if (sense[25] & DASD_SENSE_BIT_0) {
+
+		/* compound program action codes (byte25 bit 0 == '1') */
+		dasd_3990_erp_compound_retry(erp, sense);
+
+	} else {
+
+		/* single program action codes (byte25 bit 0 == '0') */
+		switch (sense[25]) {
+
+		case 0x00:	/* success - use default ERP for retries */
+			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+				    "ERP called for successful request"
+				    " - just retry");
+			break;
+
+		case 0x01:	/* fatal error */
+			dev_err(&device->cdev->dev,
+				    "ERP failed for the DASD\n");
+
+			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+			break;
+
+		case 0x02:	/* intervention required */
+		case 0x03:	/* intervention required during dual copy */
+			erp = dasd_3990_erp_int_req(erp);
+			break;
+
+		case 0x0F:  /* length mismatch during update write command
+			       internal error 08 - update write command error*/
+			dev_err(&device->cdev->dev, "An error occurred in the "
+				"DASD device driver, reason=%s\n", "08");
+
+			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+			break;
+
+		case 0x10:  /* logging required for other channel program */
+			erp = dasd_3990_erp_action_10_32(erp, sense);
+			break;
+
+		case 0x15:	/* next track outside defined extend
+				   internal error 07 - The next track is not
+				   within the defined storage extent */
+			dev_err(&device->cdev->dev,
+				"An error occurred in the DASD device driver, "
+				"reason=%s\n", "07");
+
+			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
+			break;
+
+		case 0x1B:	/* unexpected condition during write */
+
+			erp = dasd_3990_erp_action_1B_32(erp, sense);
+			break;
+
+		case 0x1C:	/* invalid data */
+			dev_emerg(&device->cdev->dev,
+				    "Data recovered during retry with PCI "
+				    "fetch mode active\n");
+
+			/* not possible to handle this situation in Linux */
+			panic
+			    ("Invalid data - No way to inform application "
+			     "about the possibly incorrect data");
+			break;
+
+		case 0x1D:	/* state-change pending */
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				    "A State change pending condition exists "
+				    "for the subsystem or device");
+
+			erp = dasd_3990_erp_action_4(erp, sense);
+			break;
+
+		case 0x1E:	/* busy */
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				    "Busy condition exists "
+				    "for the subsystem or device");
+                        erp = dasd_3990_erp_action_4(erp, sense);
+			break;
+
+		default:	/* all others errors - default erp  */
+			break;
+		}
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_inspect_32 */
+
+static void dasd_3990_erp_disable_path(struct dasd_device *device, __u8 lpum)
+{
+	int pos = pathmask_to_pos(lpum);
+
+	if (!(device->features & DASD_FEATURE_PATH_AUTODISABLE)) {
+		dev_err(&device->cdev->dev,
+			"Path %x.%02x (pathmask %02x) is operational despite excessive IFCCs\n",
+			device->path[pos].cssid, device->path[pos].chpid, lpum);
+		goto out;
+	}
+
+	/* no remaining path, cannot disable */
+	if (!(dasd_path_get_opm(device) & ~lpum)) {
+		dev_err(&device->cdev->dev,
+			"Last path %x.%02x (pathmask %02x) is operational despite excessive IFCCs\n",
+			device->path[pos].cssid, device->path[pos].chpid, lpum);
+		goto out;
+	}
+
+	dev_err(&device->cdev->dev,
+		"Path %x.%02x (pathmask %02x) is disabled - IFCC threshold exceeded\n",
+		device->path[pos].cssid, device->path[pos].chpid, lpum);
+	dasd_path_remove_opm(device, lpum);
+	dasd_path_add_ifccpm(device, lpum);
+
+out:
+	device->path[pos].errorclk = 0;
+	atomic_set(&device->path[pos].error_count, 0);
+}
+
+static void dasd_3990_erp_account_error(struct dasd_ccw_req *erp)
+{
+	struct dasd_device *device = erp->startdev;
+	__u8 lpum = erp->refers->irb.esw.esw1.lpum;
+	int pos = pathmask_to_pos(lpum);
+	unsigned long clk;
+
+	if (!device->path_thrhld)
+		return;
+
+	clk = get_tod_clock();
+	/*
+	 * check if the last error is longer ago than the timeout,
+	 * if so reset error state
+	 */
+	if ((tod_to_ns(clk - device->path[pos].errorclk) / NSEC_PER_SEC)
+	    >= device->path_interval) {
+		atomic_set(&device->path[pos].error_count, 0);
+		device->path[pos].errorclk = 0;
+	}
+	atomic_inc(&device->path[pos].error_count);
+	device->path[pos].errorclk = clk;
+	/* threshold exceeded disable path if possible */
+	if (atomic_read(&device->path[pos].error_count) >=
+	    device->path_thrhld)
+		dasd_3990_erp_disable_path(device, lpum);
+}
+
+/*
+ *****************************************************************************
+ * main ERP control functions (24 and 32 byte sense)
+ *****************************************************************************
+ */
+
+/*
+ * DASD_3990_ERP_CONTROL_CHECK
+ *
+ * DESCRIPTION
+ *   Does a generic inspection if a control check occurred and sets up
+ *   the related error recovery procedure
+ *
+ * PARAMETER
+ *   erp		pointer to the currently created default ERP
+ *
+ * RETURN VALUES
+ *   erp_filled		pointer to the erp
+ */
+
+static struct dasd_ccw_req *
+dasd_3990_erp_control_check(struct dasd_ccw_req *erp)
+{
+	struct dasd_device *device = erp->startdev;
+
+	if (scsw_cstat(&erp->refers->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK
+					   | SCHN_STAT_CHN_CTRL_CHK)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "channel or interface control check");
+		dasd_3990_erp_account_error(erp);
+		erp = dasd_3990_erp_action_4(erp, NULL);
+	}
+	return erp;
+}
+
+/*
+ * DASD_3990_ERP_INSPECT
+ *
+ * DESCRIPTION
+ *   Does a detailed inspection for sense data by calling either
+ *   the 24-byte or the 32-byte inspection routine.
+ *
+ * PARAMETER
+ *   erp		pointer to the currently created default ERP
+ * RETURN VALUES
+ *   erp_new		contens was possibly modified
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_inspect(struct dasd_ccw_req *erp)
+{
+
+	struct dasd_ccw_req *erp_new = NULL;
+	char *sense;
+
+	/* if this problem occurred on an alias retry on base */
+	erp_new = dasd_3990_erp_inspect_alias(erp);
+	if (erp_new)
+		return erp_new;
+
+	/* sense data are located in the refers record of the
+	 * already set up new ERP !
+	 * check if concurrent sens is available
+	 */
+	sense = dasd_get_sense(&erp->refers->irb);
+	if (!sense)
+		erp_new = dasd_3990_erp_control_check(erp);
+	/* distinguish between 24 and 32 byte sense data */
+	else if (sense[27] & DASD_SENSE_BIT_0) {
+
+		/* inspect the 24 byte sense data */
+		erp_new = dasd_3990_erp_inspect_24(erp, sense);
+
+	} else {
+
+		/* inspect the 32 byte sense data */
+		erp_new = dasd_3990_erp_inspect_32(erp, sense);
+
+	}	/* end distinguish between 24 and 32 byte sense data */
+
+	return erp_new;
+}
+
+/*
+ * DASD_3990_ERP_ADD_ERP
+ *
+ * DESCRIPTION
+ *   This function adds an additional request block (ERP) to the head of
+ *   the given cqr (or erp).
+ *   For a command mode cqr the erp is initialized as an default erp
+ *   (retry TIC).
+ *   For transport mode we make a copy of the original TCW (points to
+ *   the original TCCB, TIDALs, etc.) but give it a fresh
+ *   TSB so the original sense data will not be changed.
+ *
+ * PARAMETER
+ *   cqr		head of the current ERP-chain (or single cqr if
+ *			first error)
+ * RETURN VALUES
+ *   erp		pointer to new ERP-chain head
+ */
+static struct dasd_ccw_req *dasd_3990_erp_add_erp(struct dasd_ccw_req *cqr)
+{
+
+	struct dasd_device *device = cqr->startdev;
+	struct ccw1 *ccw;
+	struct dasd_ccw_req *erp;
+	int cplength, datasize;
+	struct tcw *tcw;
+	struct tsb *tsb;
+
+	if (cqr->cpmode == 1) {
+		cplength = 0;
+		/* TCW needs to be 64 byte aligned, so leave enough room */
+		datasize = 64 + sizeof(struct tcw) + sizeof(struct tsb);
+	} else {
+		cplength = 2;
+		datasize = 0;
+	}
+
+	/* allocate additional request block */
+	erp = dasd_alloc_erp_request((char *) &cqr->magic,
+				     cplength, datasize, device);
+	if (IS_ERR(erp)) {
+                if (cqr->retries <= 0) {
+			DBF_DEV_EVENT(DBF_ERR, device, "%s",
+				    "Unable to allocate ERP request");
+			cqr->status = DASD_CQR_FAILED;
+			cqr->stopclk = get_tod_clock();
+		} else {
+			DBF_DEV_EVENT(DBF_ERR, device,
+                                     "Unable to allocate ERP request "
+				     "(%i retries left)",
+                                     cqr->retries);
+			dasd_block_set_timer(device->block, (HZ << 3));
+                }
+		return erp;
+	}
+
+	ccw = cqr->cpaddr;
+	if (cqr->cpmode == 1) {
+		/* make a shallow copy of the original tcw but set new tsb */
+		erp->cpmode = 1;
+		erp->cpaddr = PTR_ALIGN(erp->data, 64);
+		tcw = erp->cpaddr;
+		tsb = (struct tsb *) &tcw[1];
+		*tcw = *((struct tcw *)cqr->cpaddr);
+		tcw->tsb = (long)tsb;
+	} else if (ccw->cmd_code == DASD_ECKD_CCW_PSF) {
+		/* PSF cannot be chained from NOOP/TIC */
+		erp->cpaddr = cqr->cpaddr;
+	} else {
+		/* initialize request with default TIC to current ERP/CQR */
+		ccw = erp->cpaddr;
+		ccw->cmd_code = CCW_CMD_NOOP;
+		ccw->flags = CCW_FLAG_CC;
+		ccw++;
+		ccw->cmd_code = CCW_CMD_TIC;
+		ccw->cda      = (long)(cqr->cpaddr);
+	}
+
+	erp->flags = cqr->flags;
+	erp->function = dasd_3990_erp_add_erp;
+	erp->refers   = cqr;
+	erp->startdev = device;
+	erp->memdev   = device;
+	erp->block    = cqr->block;
+	erp->magic    = cqr->magic;
+	erp->expires  = cqr->expires;
+	erp->retries  = 256;
+	erp->buildclk = get_tod_clock();
+	erp->status = DASD_CQR_FILLED;
+
+	return erp;
+}
+
+/*
+ * DASD_3990_ERP_ADDITIONAL_ERP
+ *
+ * DESCRIPTION
+ *   An additional ERP is needed to handle the current error.
+ *   Add ERP to the head of the ERP-chain containing the ERP processing
+ *   determined based on the sense data.
+ *
+ * PARAMETER
+ *   cqr		head of the current ERP-chain (or single cqr if
+ *			first error)
+ *
+ * RETURN VALUES
+ *   erp		pointer to new ERP-chain head
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_additional_erp(struct dasd_ccw_req * cqr)
+{
+
+	struct dasd_ccw_req *erp = NULL;
+
+	/* add erp and initialize with default TIC */
+	erp = dasd_3990_erp_add_erp(cqr);
+
+	if (IS_ERR(erp))
+		return erp;
+
+	/* inspect sense, determine specific ERP if possible */
+	if (erp != cqr) {
+
+		erp = dasd_3990_erp_inspect(erp);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_additional_erp */
+
+/*
+ * DASD_3990_ERP_ERROR_MATCH
+ *
+ * DESCRIPTION
+ *   Check if the device status of the given cqr is the same.
+ *   This means that the failed CCW and the relevant sense data
+ *   must match.
+ *   I don't distinguish between 24 and 32 byte sense because in case of
+ *   24 byte sense byte 25 and 27 is set as well.
+ *
+ * PARAMETER
+ *   cqr1		first cqr, which will be compared with the
+ *   cqr2		second cqr.
+ *
+ * RETURN VALUES
+ *   match		'boolean' for match found
+ *			returns 1 if match found, otherwise 0.
+ */
+static int dasd_3990_erp_error_match(struct dasd_ccw_req *cqr1,
+				     struct dasd_ccw_req *cqr2)
+{
+	char *sense1, *sense2;
+
+	if (cqr1->startdev != cqr2->startdev)
+		return 0;
+
+	sense1 = dasd_get_sense(&cqr1->irb);
+	sense2 = dasd_get_sense(&cqr2->irb);
+
+	/* one request has sense data, the other not -> no match, return 0 */
+	if (!sense1 != !sense2)
+		return 0;
+	/* no sense data in both cases -> check cstat for IFCC */
+	if (!sense1 && !sense2)	{
+		if ((scsw_cstat(&cqr1->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK |
+						    SCHN_STAT_CHN_CTRL_CHK)) ==
+		    (scsw_cstat(&cqr2->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK |
+						    SCHN_STAT_CHN_CTRL_CHK)))
+			return 1; /* match with ifcc*/
+	}
+	/* check sense data; byte 0-2,25,27 */
+	if (!(sense1 && sense2 &&
+	      (memcmp(sense1, sense2, 3) == 0) &&
+	      (sense1[27] == sense2[27]) &&
+	      (sense1[25] == sense2[25]))) {
+
+		return 0;	/* sense doesn't match */
+	}
+
+	return 1;		/* match */
+
+}				/* end dasd_3990_erp_error_match */
+
+/*
+ * DASD_3990_ERP_IN_ERP
+ *
+ * DESCRIPTION
+ *   check if the current error already happened before.
+ *   quick exit if current cqr is not an ERP (cqr->refers=NULL)
+ *
+ * PARAMETER
+ *   cqr		failed cqr (either original cqr or already an erp)
+ *
+ * RETURN VALUES
+ *   erp		erp-pointer to the already defined error
+ *			recovery procedure OR
+ *			NULL if a 'new' error occurred.
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_in_erp(struct dasd_ccw_req *cqr)
+{
+
+	struct dasd_ccw_req *erp_head = cqr,	/* save erp chain head */
+	*erp_match = NULL;	/* save erp chain head */
+	int match = 0;		/* 'boolean' for matching error found */
+
+	if (cqr->refers == NULL) {	/* return if not in erp */
+		return NULL;
+	}
+
+	/* check the erp/cqr chain for current error */
+	do {
+		match = dasd_3990_erp_error_match(erp_head, cqr->refers);
+		erp_match = cqr;	/* save possible matching erp  */
+		cqr = cqr->refers;	/* check next erp/cqr in queue */
+
+	} while ((cqr->refers != NULL) && (!match));
+
+	if (!match) {
+		return NULL;	/* no match was found */
+	}
+
+	return erp_match;	/* return address of matching erp */
+
+}				/* END dasd_3990_erp_in_erp */
+
+/*
+ * DASD_3990_ERP_FURTHER_ERP (24 & 32 byte sense)
+ *
+ * DESCRIPTION
+ *   No retry is left for the current ERP. Check what has to be done
+ *   with the ERP.
+ *     - do further defined ERP action or
+ *     - wait for interrupt or
+ *     - exit with permanent error
+ *
+ * PARAMETER
+ *   erp		ERP which is in progress with no retry left
+ *
+ * RETURN VALUES
+ *   erp		modified/additional ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_further_erp(struct dasd_ccw_req *erp)
+{
+
+	struct dasd_device *device = erp->startdev;
+	char *sense = dasd_get_sense(&erp->irb);
+
+	/* check for 24 byte sense ERP */
+	if ((erp->function == dasd_3990_erp_bus_out) ||
+	    (erp->function == dasd_3990_erp_action_1) ||
+	    (erp->function == dasd_3990_erp_action_4)) {
+
+		erp = dasd_3990_erp_action_1(erp);
+
+	} else if (erp->function == dasd_3990_erp_action_1_sec) {
+		erp = dasd_3990_erp_action_1_sec(erp);
+	} else if (erp->function == dasd_3990_erp_action_5) {
+
+		/* retries have not been successful */
+		/* prepare erp for retry on different channel path */
+		erp = dasd_3990_erp_action_1(erp);
+
+		if (sense && !(sense[2] & DASD_SENSE_BIT_0)) {
+
+			/* issue a Diagnostic Control command with an
+			 * Inhibit Write subcommand */
+
+			switch (sense[25]) {
+			case 0x17:
+			case 0x57:{	/* controller */
+					erp = dasd_3990_erp_DCTL(erp, 0x20);
+					break;
+				}
+			case 0x18:
+			case 0x58:{	/* channel path */
+					erp = dasd_3990_erp_DCTL(erp, 0x40);
+					break;
+				}
+			case 0x19:
+			case 0x59:{	/* storage director */
+					erp = dasd_3990_erp_DCTL(erp, 0x80);
+					break;
+				}
+			default:
+				DBF_DEV_EVENT(DBF_WARNING, device,
+					    "invalid subcommand modifier 0x%x "
+					    "for Diagnostic Control Command",
+					    sense[25]);
+			}
+		}
+
+		/* check for 32 byte sense ERP */
+	} else if (sense &&
+		   ((erp->function == dasd_3990_erp_compound_retry) ||
+		    (erp->function == dasd_3990_erp_compound_path) ||
+		    (erp->function == dasd_3990_erp_compound_code) ||
+		    (erp->function == dasd_3990_erp_compound_config))) {
+
+		erp = dasd_3990_erp_compound(erp, sense);
+
+	} else {
+		/*
+		 * No retry left and no additional special handling
+		 * necessary
+		 */
+		dev_err(&device->cdev->dev,
+			"ERP %p has run out of retries and failed\n", erp);
+
+		erp->status = DASD_CQR_FAILED;
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_further_erp */
+
+/*
+ * DASD_3990_ERP_HANDLE_MATCH_ERP
+ *
+ * DESCRIPTION
+ *   An error occurred again and an ERP has been detected which is already
+ *   used to handle this error (e.g. retries).
+ *   All prior ERP's are asumed to be successful and therefore removed
+ *   from queue.
+ *   If retry counter of matching erp is already 0, it is checked if further
+ *   action is needed (besides retry) or if the ERP has failed.
+ *
+ * PARAMETER
+ *   erp_head		first ERP in ERP-chain
+ *   erp		ERP that handles the actual error.
+ *			(matching erp)
+ *
+ * RETURN VALUES
+ *   erp		modified/additional ERP
+ */
+static struct dasd_ccw_req *
+dasd_3990_erp_handle_match_erp(struct dasd_ccw_req *erp_head,
+			       struct dasd_ccw_req *erp)
+{
+
+	struct dasd_device *device = erp_head->startdev;
+	struct dasd_ccw_req *erp_done = erp_head;	/* finished req */
+	struct dasd_ccw_req *erp_free = NULL;	/* req to be freed */
+
+	/* loop over successful ERPs and remove them from chanq */
+	while (erp_done != erp) {
+
+		if (erp_done == NULL)	/* end of chain reached */
+			panic(PRINTK_HEADER "Programming error in ERP! The "
+			      "original request was lost\n");
+
+		/* remove the request from the device queue */
+		list_del(&erp_done->blocklist);
+
+		erp_free = erp_done;
+		erp_done = erp_done->refers;
+
+		/* free the finished erp request */
+		dasd_free_erp_request(erp_free, erp_free->memdev);
+
+	}			/* end while */
+
+	if (erp->retries > 0) {
+
+		char *sense = dasd_get_sense(&erp->refers->irb);
+
+		/* check for special retries */
+		if (sense && erp->function == dasd_3990_erp_action_4) {
+
+			erp = dasd_3990_erp_action_4(erp, sense);
+
+		} else if (sense &&
+			   erp->function == dasd_3990_erp_action_1B_32) {
+
+			erp = dasd_3990_update_1B(erp, sense);
+
+		} else if (sense && erp->function == dasd_3990_erp_int_req) {
+
+			erp = dasd_3990_erp_int_req(erp);
+
+		} else {
+			/* simple retry	  */
+			DBF_DEV_EVENT(DBF_DEBUG, device,
+				    "%i retries left for erp %p",
+				    erp->retries, erp);
+
+			/* handle the request again... */
+			erp->status = DASD_CQR_FILLED;
+		}
+
+	} else {
+		/* no retry left - check for further necessary action	 */
+		/* if no further actions, handle rest as permanent error */
+		erp = dasd_3990_erp_further_erp(erp);
+	}
+
+	return erp;
+
+}				/* end dasd_3990_erp_handle_match_erp */
+
+/*
+ * DASD_3990_ERP_ACTION
+ *
+ * DESCRIPTION
+ *   control routine for 3990 erp actions.
+ *   Has to be called with the queue lock (namely the s390_irq_lock) acquired.
+ *
+ * PARAMETER
+ *   cqr		failed cqr (either original cqr or already an erp)
+ *
+ * RETURN VALUES
+ *   erp		erp-pointer to the head of the ERP action chain.
+ *			This means:
+ *			 - either a ptr to an additional ERP cqr or
+ *			 - the original given cqr (which's status might
+ *			   be modified)
+ */
+struct dasd_ccw_req *
+dasd_3990_erp_action(struct dasd_ccw_req * cqr)
+{
+	struct dasd_ccw_req *erp = NULL;
+	struct dasd_device *device = cqr->startdev;
+	struct dasd_ccw_req *temp_erp = NULL;
+
+	if (device->features & DASD_FEATURE_ERPLOG) {
+		/* print current erp_chain */
+		dev_err(&device->cdev->dev,
+			    "ERP chain at BEGINNING of ERP-ACTION\n");
+		for (temp_erp = cqr;
+		     temp_erp != NULL; temp_erp = temp_erp->refers) {
+
+			dev_err(&device->cdev->dev,
+				    "ERP %p (%02x) refers to %p\n",
+				    temp_erp, temp_erp->status,
+				    temp_erp->refers);
+		}
+	}
+
+	/* double-check if current erp/cqr was successful */
+	if ((scsw_cstat(&cqr->irb.scsw) == 0x00) &&
+	    (scsw_dstat(&cqr->irb.scsw) ==
+	     (DEV_STAT_CHN_END | DEV_STAT_DEV_END))) {
+
+		DBF_DEV_EVENT(DBF_DEBUG, device,
+			    "ERP called for successful request %p"
+			    " - NO ERP necessary", cqr);
+
+		cqr->status = DASD_CQR_DONE;
+
+		return cqr;
+	}
+
+	/* check if error happened before */
+	erp = dasd_3990_erp_in_erp(cqr);
+
+	if (erp == NULL) {
+		/* no matching erp found - set up erp */
+		erp = dasd_3990_erp_additional_erp(cqr);
+		if (IS_ERR(erp))
+			return erp;
+	} else {
+		/* matching erp found - set all leading erp's to DONE */
+		erp = dasd_3990_erp_handle_match_erp(cqr, erp);
+	}
+
+
+	/*
+	 * For path verification work we need to stick with the path that was
+	 * originally chosen so that the per path configuration data is
+	 * assigned correctly.
+	 */
+	if (test_bit(DASD_CQR_VERIFY_PATH, &erp->flags) && cqr->lpm) {
+		erp->lpm = cqr->lpm;
+	}
+
+	if (device->features & DASD_FEATURE_ERPLOG) {
+		/* print current erp_chain */
+		dev_err(&device->cdev->dev,
+			    "ERP chain at END of ERP-ACTION\n");
+		for (temp_erp = erp;
+		     temp_erp != NULL; temp_erp = temp_erp->refers) {
+
+			dev_err(&device->cdev->dev,
+				    "ERP %p (%02x) refers to %p\n",
+				    temp_erp, temp_erp->status,
+				    temp_erp->refers);
+		}
+	}
+
+	/* enqueue ERP request if it's a new one */
+	if (list_empty(&erp->blocklist)) {
+		cqr->status = DASD_CQR_IN_ERP;
+		/* add erp request before the cqr */
+		list_add_tail(&erp->blocklist, &cqr->blocklist);
+	}
+
+
+
+	return erp;
+
+}				/* end dasd_3990_erp_action */
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
new file mode 100644
index 000000000..dc78a523a
--- /dev/null
+++ b/drivers/s390/block/dasd_alias.c
@@ -0,0 +1,976 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PAV alias management for the DASD ECKD discipline
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Stefan Weinhuber <wein@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "dasd-eckd"
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <asm/ebcdic.h>
+#include "dasd_int.h"
+#include "dasd_eckd.h"
+
+#ifdef PRINTK_HEADER
+#undef PRINTK_HEADER
+#endif				/* PRINTK_HEADER */
+#define PRINTK_HEADER "dasd(eckd):"
+
+
+/*
+ * General concept of alias management:
+ * - PAV and DASD alias management is specific to the eckd discipline.
+ * - A device is connected to an lcu as long as the device exists.
+ *   dasd_alias_make_device_known_to_lcu will be called wenn the
+ *   device is checked by the eckd discipline and
+ *   dasd_alias_disconnect_device_from_lcu will be called
+ *   before the device is deleted.
+ * - The dasd_alias_add_device / dasd_alias_remove_device
+ *   functions mark the point when a device is 'ready for service'.
+ * - A summary unit check is a rare occasion, but it is mandatory to
+ *   support it. It requires some complex recovery actions before the
+ *   devices can be used again (see dasd_alias_handle_summary_unit_check).
+ * - dasd_alias_get_start_dev will find an alias device that can be used
+ *   instead of the base device and does some (very simple) load balancing.
+ *   This is the function that gets called for each I/O, so when improving
+ *   something, this function should get faster or better, the rest has just
+ *   to be correct.
+ */
+
+
+static void summary_unit_check_handling_work(struct work_struct *);
+static void lcu_update_work(struct work_struct *);
+static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
+
+static struct alias_root aliastree = {
+	.serverlist = LIST_HEAD_INIT(aliastree.serverlist),
+	.lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
+};
+
+static struct alias_server *_find_server(struct dasd_uid *uid)
+{
+	struct alias_server *pos;
+	list_for_each_entry(pos, &aliastree.serverlist, server) {
+		if (!strncmp(pos->uid.vendor, uid->vendor,
+			     sizeof(uid->vendor))
+		    && !strncmp(pos->uid.serial, uid->serial,
+				sizeof(uid->serial)))
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_lcu *_find_lcu(struct alias_server *server,
+				   struct dasd_uid *uid)
+{
+	struct alias_lcu *pos;
+	list_for_each_entry(pos, &server->lculist, lcu) {
+		if (pos->uid.ssid == uid->ssid)
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
+					   struct dasd_uid *uid)
+{
+	struct alias_pav_group *pos;
+	__u8 search_unit_addr;
+
+	/* for hyper pav there is only one group */
+	if (lcu->pav == HYPER_PAV) {
+		if (list_empty(&lcu->grouplist))
+			return NULL;
+		else
+			return list_first_entry(&lcu->grouplist,
+						struct alias_pav_group, group);
+	}
+
+	/* for base pav we have to find the group that matches the base */
+	if (uid->type == UA_BASE_DEVICE)
+		search_unit_addr = uid->real_unit_addr;
+	else
+		search_unit_addr = uid->base_unit_addr;
+	list_for_each_entry(pos, &lcu->grouplist, group) {
+		if (pos->uid.base_unit_addr == search_unit_addr &&
+		    !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_server *_allocate_server(struct dasd_uid *uid)
+{
+	struct alias_server *server;
+
+	server = kzalloc(sizeof(*server), GFP_KERNEL);
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+	memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
+	memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
+	INIT_LIST_HEAD(&server->server);
+	INIT_LIST_HEAD(&server->lculist);
+	return server;
+}
+
+static void _free_server(struct alias_server *server)
+{
+	kfree(server);
+}
+
+static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
+{
+	struct alias_lcu *lcu;
+
+	lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
+	if (!lcu)
+		return ERR_PTR(-ENOMEM);
+	lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
+	if (!lcu->uac)
+		goto out_err1;
+	lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr)
+		goto out_err2;
+	lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
+				       GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr->cpaddr)
+		goto out_err3;
+	lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr->data)
+		goto out_err4;
+
+	memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
+	memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
+	lcu->uid.ssid = uid->ssid;
+	lcu->pav = NO_PAV;
+	lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
+	INIT_LIST_HEAD(&lcu->lcu);
+	INIT_LIST_HEAD(&lcu->inactive_devices);
+	INIT_LIST_HEAD(&lcu->active_devices);
+	INIT_LIST_HEAD(&lcu->grouplist);
+	INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
+	INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
+	spin_lock_init(&lcu->lock);
+	init_completion(&lcu->lcu_setup);
+	return lcu;
+
+out_err4:
+	kfree(lcu->rsu_cqr->cpaddr);
+out_err3:
+	kfree(lcu->rsu_cqr);
+out_err2:
+	kfree(lcu->uac);
+out_err1:
+	kfree(lcu);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void _free_lcu(struct alias_lcu *lcu)
+{
+	kfree(lcu->rsu_cqr->data);
+	kfree(lcu->rsu_cqr->cpaddr);
+	kfree(lcu->rsu_cqr);
+	kfree(lcu->uac);
+	kfree(lcu);
+}
+
+/*
+ * This is the function that will allocate all the server and lcu data,
+ * so this function must be called first for a new device.
+ * If the return value is 1, the lcu was already known before, if it
+ * is 0, this is a new lcu.
+ * Negative return code indicates that something went wrong (e.g. -ENOMEM)
+ */
+int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+	struct alias_server *server, *newserver;
+	struct alias_lcu *lcu, *newlcu;
+	struct dasd_uid uid;
+
+	device->discipline->get_uid(device, &uid);
+	spin_lock_irqsave(&aliastree.lock, flags);
+	server = _find_server(&uid);
+	if (!server) {
+		spin_unlock_irqrestore(&aliastree.lock, flags);
+		newserver = _allocate_server(&uid);
+		if (IS_ERR(newserver))
+			return PTR_ERR(newserver);
+		spin_lock_irqsave(&aliastree.lock, flags);
+		server = _find_server(&uid);
+		if (!server) {
+			list_add(&newserver->server, &aliastree.serverlist);
+			server = newserver;
+		} else {
+			/* someone was faster */
+			_free_server(newserver);
+		}
+	}
+
+	lcu = _find_lcu(server, &uid);
+	if (!lcu) {
+		spin_unlock_irqrestore(&aliastree.lock, flags);
+		newlcu = _allocate_lcu(&uid);
+		if (IS_ERR(newlcu))
+			return PTR_ERR(newlcu);
+		spin_lock_irqsave(&aliastree.lock, flags);
+		lcu = _find_lcu(server, &uid);
+		if (!lcu) {
+			list_add(&newlcu->lcu, &server->lculist);
+			lcu = newlcu;
+		} else {
+			/* someone was faster */
+			_free_lcu(newlcu);
+		}
+	}
+	spin_lock(&lcu->lock);
+	list_add(&device->alias_list, &lcu->inactive_devices);
+	private->lcu = lcu;
+	spin_unlock(&lcu->lock);
+	spin_unlock_irqrestore(&aliastree.lock, flags);
+
+	return 0;
+}
+
+/*
+ * This function removes a device from the scope of alias management.
+ * The complicated part is to make sure that it is not in use by
+ * any of the workers. If necessary cancel the work.
+ */
+void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+	struct alias_lcu *lcu;
+	struct alias_server *server;
+	int was_pending;
+	struct dasd_uid uid;
+
+	lcu = private->lcu;
+	/* nothing to do if already disconnected */
+	if (!lcu)
+		return;
+	device->discipline->get_uid(device, &uid);
+	spin_lock_irqsave(&lcu->lock, flags);
+	/* make sure that the workers don't use this device */
+	if (device == lcu->suc_data.device) {
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		cancel_work_sync(&lcu->suc_data.worker);
+		spin_lock_irqsave(&lcu->lock, flags);
+		if (device == lcu->suc_data.device) {
+			dasd_put_device(device);
+			lcu->suc_data.device = NULL;
+		}
+	}
+	was_pending = 0;
+	if (device == lcu->ruac_data.device) {
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		was_pending = 1;
+		cancel_delayed_work_sync(&lcu->ruac_data.dwork);
+		spin_lock_irqsave(&lcu->lock, flags);
+		if (device == lcu->ruac_data.device) {
+			dasd_put_device(device);
+			lcu->ruac_data.device = NULL;
+		}
+	}
+	private->lcu = NULL;
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	spin_lock_irqsave(&aliastree.lock, flags);
+	spin_lock(&lcu->lock);
+	list_del_init(&device->alias_list);
+	if (list_empty(&lcu->grouplist) &&
+	    list_empty(&lcu->active_devices) &&
+	    list_empty(&lcu->inactive_devices)) {
+		list_del(&lcu->lcu);
+		spin_unlock(&lcu->lock);
+		_free_lcu(lcu);
+		lcu = NULL;
+	} else {
+		if (was_pending)
+			_schedule_lcu_update(lcu, NULL);
+		spin_unlock(&lcu->lock);
+	}
+	server = _find_server(&uid);
+	if (server && list_empty(&server->lculist)) {
+		list_del(&server->server);
+		_free_server(server);
+	}
+	spin_unlock_irqrestore(&aliastree.lock, flags);
+}
+
+/*
+ * This function assumes that the unit address configuration stored
+ * in the lcu is up to date and will update the device uid before
+ * adding it to a pav group.
+ */
+
+static int _add_device_to_lcu(struct alias_lcu *lcu,
+			      struct dasd_device *device,
+			      struct dasd_device *pos)
+{
+
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *group;
+	struct dasd_uid uid;
+
+	spin_lock(get_ccwdev_lock(device->cdev));
+	private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
+	private->uid.base_unit_addr =
+		lcu->uac->unit[private->uid.real_unit_addr].base_ua;
+	uid = private->uid;
+	spin_unlock(get_ccwdev_lock(device->cdev));
+	/* if we have no PAV anyway, we don't need to bother with PAV groups */
+	if (lcu->pav == NO_PAV) {
+		list_move(&device->alias_list, &lcu->active_devices);
+		return 0;
+	}
+	group = _find_group(lcu, &uid);
+	if (!group) {
+		group = kzalloc(sizeof(*group), GFP_ATOMIC);
+		if (!group)
+			return -ENOMEM;
+		memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
+		memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
+		group->uid.ssid = uid.ssid;
+		if (uid.type == UA_BASE_DEVICE)
+			group->uid.base_unit_addr = uid.real_unit_addr;
+		else
+			group->uid.base_unit_addr = uid.base_unit_addr;
+		memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
+		INIT_LIST_HEAD(&group->group);
+		INIT_LIST_HEAD(&group->baselist);
+		INIT_LIST_HEAD(&group->aliaslist);
+		list_add(&group->group, &lcu->grouplist);
+	}
+	if (uid.type == UA_BASE_DEVICE)
+		list_move(&device->alias_list, &group->baselist);
+	else
+		list_move(&device->alias_list, &group->aliaslist);
+	private->pavgroup = group;
+	return 0;
+};
+
+static void _remove_device_from_lcu(struct alias_lcu *lcu,
+				    struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *group;
+
+	list_move(&device->alias_list, &lcu->inactive_devices);
+	group = private->pavgroup;
+	if (!group)
+		return;
+	private->pavgroup = NULL;
+	if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
+		list_del(&group->group);
+		kfree(group);
+		return;
+	}
+	if (group->next == device)
+		group->next = NULL;
+};
+
+static int
+suborder_not_supported(struct dasd_ccw_req *cqr)
+{
+	char *sense;
+	char reason;
+	char msg_format;
+	char msg_no;
+
+	/*
+	 * intrc values ENODEV, ENOLINK and EPERM
+	 * will be optained from sleep_on to indicate that no
+	 * IO operation can be started
+	 */
+	if (cqr->intrc == -ENODEV)
+		return 1;
+
+	if (cqr->intrc == -ENOLINK)
+		return 1;
+
+	if (cqr->intrc == -EPERM)
+		return 1;
+
+	sense = dasd_get_sense(&cqr->irb);
+	if (!sense)
+		return 0;
+
+	reason = sense[0];
+	msg_format = (sense[7] & 0xF0);
+	msg_no = (sense[7] & 0x0F);
+
+	/* command reject, Format 0 MSG 4 - invalid parameter */
+	if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04))
+		return 1;
+
+	return 0;
+}
+
+static int read_unit_address_configuration(struct dasd_device *device,
+					   struct alias_lcu *lcu)
+{
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+	unsigned long flags;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
+				   (sizeof(struct dasd_psf_prssd_data)),
+				   device, NULL);
+	if (IS_ERR(cqr))
+		return PTR_ERR(cqr);
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->retries = 10;
+	cqr->expires = 20 * HZ;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = 0x0e;	/* Read unit address configuration */
+	/* all other bytes of prssdp must be zero */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->cda = (__u32)(addr_t) prssdp;
+
+	/* Read Subsystem Data - feature codes */
+	memset(lcu->uac, 0, sizeof(*(lcu->uac)));
+
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(*(lcu->uac));
+	ccw->cda = (__u32)(addr_t) lcu->uac;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	/* need to unset flag here to detect race with summary unit check */
+	spin_lock_irqsave(&lcu->lock, flags);
+	lcu->flags &= ~NEED_UAC_UPDATE;
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	rc = dasd_sleep_on(cqr);
+	if (!rc)
+		goto out;
+
+	if (suborder_not_supported(cqr)) {
+		/* suborder not supported or device unusable for IO */
+		rc = -EOPNOTSUPP;
+	} else {
+		/* IO failed but should be retried */
+		spin_lock_irqsave(&lcu->lock, flags);
+		lcu->flags |= NEED_UAC_UPDATE;
+		spin_unlock_irqrestore(&lcu->lock, flags);
+	}
+out:
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
+{
+	unsigned long flags;
+	struct alias_pav_group *pavgroup, *tempgroup;
+	struct dasd_device *device, *tempdev;
+	int i, rc;
+	struct dasd_eckd_private *private;
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
+		list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
+					 alias_list) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+		list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist,
+					 alias_list) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+		list_del(&pavgroup->group);
+		kfree(pavgroup);
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	rc = read_unit_address_configuration(refdev, lcu);
+	if (rc)
+		return rc;
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	/*
+	 * there is another update needed skip the remaining handling
+	 * the data might already be outdated
+	 * but especially do not add the device to an LCU with pending
+	 * update
+	 */
+	if (lcu->flags & NEED_UAC_UPDATE)
+		goto out;
+	lcu->pav = NO_PAV;
+	for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
+		switch (lcu->uac->unit[i].ua_type) {
+		case UA_BASE_PAV_ALIAS:
+			lcu->pav = BASE_PAV;
+			break;
+		case UA_HYPER_PAV_ALIAS:
+			lcu->pav = HYPER_PAV;
+			break;
+		}
+		if (lcu->pav != NO_PAV)
+			break;
+	}
+
+	list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
+				 alias_list) {
+		_add_device_to_lcu(lcu, device, refdev);
+	}
+out:
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return 0;
+}
+
+static void lcu_update_work(struct work_struct *work)
+{
+	struct alias_lcu *lcu;
+	struct read_uac_work_data *ruac_data;
+	struct dasd_device *device;
+	unsigned long flags;
+	int rc;
+
+	ruac_data = container_of(work, struct read_uac_work_data, dwork.work);
+	lcu = container_of(ruac_data, struct alias_lcu, ruac_data);
+	device = ruac_data->device;
+	rc = _lcu_update(device, lcu);
+	/*
+	 * Need to check flags again, as there could have been another
+	 * prepare_update or a new device a new device while we were still
+	 * processing the data
+	 */
+	spin_lock_irqsave(&lcu->lock, flags);
+	if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
+			    " alias data in lcu (rc = %d), retry later", rc);
+		if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ))
+			dasd_put_device(device);
+	} else {
+		dasd_put_device(device);
+		lcu->ruac_data.device = NULL;
+		lcu->flags &= ~UPDATE_PENDING;
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+static int _schedule_lcu_update(struct alias_lcu *lcu,
+				struct dasd_device *device)
+{
+	struct dasd_device *usedev = NULL;
+	struct alias_pav_group *group;
+
+	lcu->flags |= NEED_UAC_UPDATE;
+	if (lcu->ruac_data.device) {
+		/* already scheduled or running */
+		return 0;
+	}
+	if (device && !list_empty(&device->alias_list))
+		usedev = device;
+
+	if (!usedev && !list_empty(&lcu->grouplist)) {
+		group = list_first_entry(&lcu->grouplist,
+					 struct alias_pav_group, group);
+		if (!list_empty(&group->baselist))
+			usedev = list_first_entry(&group->baselist,
+						  struct dasd_device,
+						  alias_list);
+		else if (!list_empty(&group->aliaslist))
+			usedev = list_first_entry(&group->aliaslist,
+						  struct dasd_device,
+						  alias_list);
+	}
+	if (!usedev && !list_empty(&lcu->active_devices)) {
+		usedev = list_first_entry(&lcu->active_devices,
+					  struct dasd_device, alias_list);
+	}
+	/*
+	 * if we haven't found a proper device yet, give up for now, the next
+	 * device that will be set active will trigger an lcu update
+	 */
+	if (!usedev)
+		return -EINVAL;
+	dasd_get_device(usedev);
+	lcu->ruac_data.device = usedev;
+	if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0))
+		dasd_put_device(usedev);
+	return 0;
+}
+
+int dasd_alias_add_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	__u8 uaddr = private->uid.real_unit_addr;
+	struct alias_lcu *lcu = private->lcu;
+	unsigned long flags;
+	int rc;
+
+	rc = 0;
+	spin_lock_irqsave(&lcu->lock, flags);
+	/*
+	 * Check if device and lcu type differ. If so, the uac data may be
+	 * outdated and needs to be updated.
+	 */
+	if (private->uid.type !=  lcu->uac->unit[uaddr].ua_type) {
+		lcu->flags |= UPDATE_PENDING;
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "uid type mismatch - trigger rescan");
+	}
+	if (!(lcu->flags & UPDATE_PENDING)) {
+		rc = _add_device_to_lcu(lcu, device, device);
+		if (rc)
+			lcu->flags |= UPDATE_PENDING;
+	}
+	if (lcu->flags & UPDATE_PENDING) {
+		list_move(&device->alias_list, &lcu->active_devices);
+		private->pavgroup = NULL;
+		_schedule_lcu_update(lcu, device);
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return rc;
+}
+
+int dasd_alias_update_add_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	private->lcu->flags |= UPDATE_PENDING;
+	return dasd_alias_add_device(device);
+}
+
+int dasd_alias_remove_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_lcu *lcu = private->lcu;
+	unsigned long flags;
+
+	/* nothing to do if already removed */
+	if (!lcu)
+		return 0;
+	spin_lock_irqsave(&lcu->lock, flags);
+	_remove_device_from_lcu(lcu, device);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return 0;
+}
+
+struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device)
+{
+	struct dasd_eckd_private *alias_priv, *private = base_device->private;
+	struct alias_pav_group *group = private->pavgroup;
+	struct alias_lcu *lcu = private->lcu;
+	struct dasd_device *alias_device;
+	unsigned long flags;
+
+	if (!group || !lcu)
+		return NULL;
+	if (lcu->pav == NO_PAV ||
+	    lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING))
+		return NULL;
+	if (unlikely(!(private->features.feature[8] & 0x01))) {
+		/*
+		 * PAV enabled but prefix not, very unlikely
+		 * seems to be a lost pathgroup
+		 * use base device to do IO
+		 */
+		DBF_DEV_EVENT(DBF_ERR, base_device, "%s",
+			      "Prefix not enabled with PAV enabled\n");
+		return NULL;
+	}
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	alias_device = group->next;
+	if (!alias_device) {
+		if (list_empty(&group->aliaslist)) {
+			spin_unlock_irqrestore(&lcu->lock, flags);
+			return NULL;
+		} else {
+			alias_device = list_first_entry(&group->aliaslist,
+							struct dasd_device,
+							alias_list);
+		}
+	}
+	if (list_is_last(&alias_device->alias_list, &group->aliaslist))
+		group->next = list_first_entry(&group->aliaslist,
+					       struct dasd_device, alias_list);
+	else
+		group->next = list_first_entry(&alias_device->alias_list,
+					       struct dasd_device, alias_list);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	alias_priv = alias_device->private;
+	if ((alias_priv->count < private->count) && !alias_device->stopped &&
+	    !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags))
+		return alias_device;
+	else
+		return NULL;
+}
+
+/*
+ * Summary unit check handling depends on the way alias devices
+ * are handled so it is done here rather then in dasd_eckd.c
+ */
+static int reset_summary_unit_check(struct alias_lcu *lcu,
+				    struct dasd_device *device,
+				    char reason)
+{
+	struct dasd_ccw_req *cqr;
+	int rc = 0;
+	struct ccw1 *ccw;
+
+	cqr = lcu->rsu_cqr;
+	memcpy((char *) &cqr->magic, "ECKD", 4);
+	ASCEBC((char *) &cqr->magic, 4);
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_RSCK;
+	ccw->flags = CCW_FLAG_SLI;
+	ccw->count = 16;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+	((char *)cqr->data)[0] = reason;
+
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->retries = 255;	/* set retry counter to enable basic ERP */
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->expires = 5 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	return rc;
+}
+
+static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+	struct dasd_eckd_private *private;
+
+	/* active and inactive list can contain alias as well as base devices */
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		private = device->private;
+		if (private->uid.type != UA_BASE_DEVICE)
+			continue;
+		dasd_schedule_block_bh(device->block);
+		dasd_schedule_device_bh(device);
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		private = device->private;
+		if (private->uid.type != UA_BASE_DEVICE)
+			continue;
+		dasd_schedule_block_bh(device->block);
+		dasd_schedule_device_bh(device);
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			dasd_schedule_block_bh(device->block);
+			dasd_schedule_device_bh(device);
+		}
+	}
+}
+
+static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device, *temp;
+	struct dasd_eckd_private *private;
+	unsigned long flags;
+	LIST_HEAD(active);
+
+	/*
+	 * Problem here ist that dasd_flush_device_queue may wait
+	 * for termination of a request to complete. We can't keep
+	 * the lcu lock during that time, so we must assume that
+	 * the lists may have changed.
+	 * Idea: first gather all active alias devices in a separate list,
+	 * then flush the first element of this list unlocked, and afterwards
+	 * check if it is still on the list before moving it to the
+	 * active_devices list.
+	 */
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	list_for_each_entry_safe(device, temp, &lcu->active_devices,
+				 alias_list) {
+		private = device->private;
+		if (private->uid.type == UA_BASE_DEVICE)
+			continue;
+		list_move(&device->alias_list, &active);
+	}
+
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_splice_init(&pavgroup->aliaslist, &active);
+	}
+	while (!list_empty(&active)) {
+		device = list_first_entry(&active, struct dasd_device,
+					  alias_list);
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		dasd_flush_device_queue(device);
+		spin_lock_irqsave(&lcu->lock, flags);
+		/*
+		 * only move device around if it wasn't moved away while we
+		 * were waiting for the flush
+		 */
+		if (device == list_first_entry(&active,
+					       struct dasd_device, alias_list)) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+static void _stop_all_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+		list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+	}
+}
+
+static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+		list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+	}
+}
+
+static void summary_unit_check_handling_work(struct work_struct *work)
+{
+	struct alias_lcu *lcu;
+	struct summary_unit_check_work_data *suc_data;
+	unsigned long flags;
+	struct dasd_device *device;
+
+	suc_data = container_of(work, struct summary_unit_check_work_data,
+				worker);
+	lcu = container_of(suc_data, struct alias_lcu, suc_data);
+	device = suc_data->device;
+
+	/* 1. flush alias devices */
+	flush_all_alias_devices_on_lcu(lcu);
+
+	/* 2. reset summary unit check */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	dasd_device_remove_stop_bits(device,
+				     (DASD_STOPPED_SU | DASD_STOPPED_PENDING));
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	reset_summary_unit_check(lcu, device, suc_data->reason);
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	_unstop_all_devices_on_lcu(lcu);
+	_restart_all_base_devices_on_lcu(lcu);
+	/* 3. read new alias configuration */
+	_schedule_lcu_update(lcu, device);
+	lcu->suc_data.device = NULL;
+	dasd_put_device(device);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+void dasd_alias_handle_summary_unit_check(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  suc_work);
+	struct dasd_eckd_private *private = device->private;
+	struct alias_lcu *lcu;
+	unsigned long flags;
+
+	lcu = private->lcu;
+	if (!lcu) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "device not ready to handle summary"
+			    " unit check (no lcu structure)");
+		goto out;
+	}
+	spin_lock_irqsave(&lcu->lock, flags);
+	/* If this device is about to be removed just return and wait for
+	 * the next interrupt on a different device
+	 */
+	if (list_empty(&device->alias_list)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "device is in offline processing,"
+			    " don't do summary unit check handling");
+		goto out_unlock;
+	}
+	if (lcu->suc_data.device) {
+		/* already scheduled or running */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "previous instance of summary unit check worker"
+			    " still pending");
+		goto out_unlock;
+	}
+	_stop_all_devices_on_lcu(lcu);
+	/* prepare for lcu_update */
+	lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
+	lcu->suc_data.reason = private->suc_reason;
+	lcu->suc_data.device = device;
+	dasd_get_device(device);
+	if (!schedule_work(&lcu->suc_data.worker))
+		dasd_put_device(device);
+out_unlock:
+	spin_unlock_irqrestore(&lcu->lock, flags);
+out:
+	clear_bit(DASD_FLAG_SUC, &device->flags);
+	dasd_put_device(device);
+};
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
new file mode 100644
index 000000000..fab35c617
--- /dev/null
+++ b/drivers/s390/block/dasd_devmap.c
@@ -0,0 +1,1747 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999,2001
+ *
+ * Device mapping and dasd= parameter parsing functions. All devmap
+ * functions may not be called from interrupt context. In particular
+ * dasd_get_device is a no-no from interrupt context.
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <asm/debug.h>
+#include <linux/uaccess.h>
+#include <asm/ipl.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_devmap:"
+#define DASD_BUS_ID_SIZE 20
+#define DASD_MAX_PARAMS 256
+
+#include "dasd_int.h"
+
+struct kmem_cache *dasd_page_cache;
+EXPORT_SYMBOL_GPL(dasd_page_cache);
+
+/*
+ * dasd_devmap_t is used to store the features and the relation
+ * between device number and device index. To find a dasd_devmap_t
+ * that corresponds to a device number of a device index each
+ * dasd_devmap_t is added to two linked lists, one to search by
+ * the device number and one to search by the device index. As
+ * soon as big minor numbers are available the device index list
+ * can be removed since the device number will then be identical
+ * to the device index.
+ */
+struct dasd_devmap {
+	struct list_head list;
+	char bus_id[DASD_BUS_ID_SIZE];
+        unsigned int devindex;
+        unsigned short features;
+	struct dasd_device *device;
+};
+
+/*
+ * Parameter parsing functions for dasd= parameter. The syntax is:
+ *   <devno>		: (0x)?[0-9a-fA-F]+
+ *   <busid>		: [0-0a-f]\.[0-9a-f]\.(0x)?[0-9a-fA-F]+
+ *   <feature>		: ro
+ *   <feature_list>	: \(<feature>(:<feature>)*\)
+ *   <devno-range>	: <devno>(-<devno>)?<feature_list>?
+ *   <busid-range>	: <busid>(-<busid>)?<feature_list>?
+ *   <devices>		: <devno-range>|<busid-range>
+ *   <dasd_module>	: dasd_diag_mod|dasd_eckd_mod|dasd_fba_mod
+ *
+ *   <dasd>		: autodetect|probeonly|<devices>(,<devices>)*
+ */
+
+int dasd_probeonly =  0;	/* is true, when probeonly mode is active */
+int dasd_autodetect = 0;	/* is true, when autodetection is active */
+int dasd_nopav = 0;		/* is true, when PAV is disabled */
+EXPORT_SYMBOL_GPL(dasd_nopav);
+int dasd_nofcx;			/* disable High Performance Ficon */
+EXPORT_SYMBOL_GPL(dasd_nofcx);
+
+/*
+ * char *dasd[] is intended to hold the ranges supplied by the dasd= statement
+ * it is named 'dasd' to directly be filled by insmod with the comma separated
+ * strings when running as a module.
+ */
+static char *dasd[DASD_MAX_PARAMS];
+module_param_array(dasd, charp, NULL, S_IRUGO);
+
+/*
+ * Single spinlock to protect devmap and servermap structures and lists.
+ */
+static DEFINE_SPINLOCK(dasd_devmap_lock);
+
+/*
+ * Hash lists for devmap structures.
+ */
+static struct list_head dasd_hashlists[256];
+int dasd_max_devindex;
+
+static struct dasd_devmap *dasd_add_busid(const char *, int);
+
+static inline int
+dasd_hash_busid(const char *bus_id)
+{
+	int hash, i;
+
+	hash = 0;
+	for (i = 0; (i < DASD_BUS_ID_SIZE) && *bus_id; i++, bus_id++)
+		hash += *bus_id;
+	return hash & 0xff;
+}
+
+#ifndef MODULE
+static int __init dasd_call_setup(char *opt)
+{
+	static int i __initdata;
+	char *tmp;
+
+	while (i < DASD_MAX_PARAMS) {
+		tmp = strsep(&opt, ",");
+		if (!tmp)
+			break;
+
+		dasd[i++] = tmp;
+	}
+
+	return 1;
+}
+
+__setup ("dasd=", dasd_call_setup);
+#endif	/* #ifndef MODULE */
+
+#define	DASD_IPLDEV	"ipldev"
+
+/*
+ * Read a device busid/devno from a string.
+ */
+static int __init dasd_busid(char *str, int *id0, int *id1, int *devno)
+{
+	unsigned int val;
+	char *tok;
+
+	/* Interpret ipldev busid */
+	if (strncmp(DASD_IPLDEV, str, strlen(DASD_IPLDEV)) == 0) {
+		if (ipl_info.type != IPL_TYPE_CCW) {
+			pr_err("The IPL device is not a CCW device\n");
+			return -EINVAL;
+		}
+		*id0 = 0;
+		*id1 = ipl_info.data.ccw.dev_id.ssid;
+		*devno = ipl_info.data.ccw.dev_id.devno;
+
+		return 0;
+	}
+
+	/* Old style 0xXXXX or XXXX */
+	if (!kstrtouint(str, 16, &val)) {
+		*id0 = *id1 = 0;
+		if (val > 0xffff)
+			return -EINVAL;
+		*devno = val;
+		return 0;
+	}
+
+	/* New style x.y.z busid */
+	tok = strsep(&str, ".");
+	if (kstrtouint(tok, 16, &val) || val > 0xff)
+		return -EINVAL;
+	*id0 = val;
+
+	tok = strsep(&str, ".");
+	if (kstrtouint(tok, 16, &val) || val > 0xff)
+		return -EINVAL;
+	*id1 = val;
+
+	tok = strsep(&str, ".");
+	if (kstrtouint(tok, 16, &val) || val > 0xffff)
+		return -EINVAL;
+	*devno = val;
+
+	return 0;
+}
+
+/*
+ * Read colon separated list of dasd features.
+ */
+static int __init dasd_feature_list(char *str)
+{
+	int features, len, rc;
+
+	features = 0;
+	rc = 0;
+
+	if (!str)
+		return DASD_FEATURE_DEFAULT;
+
+	while (1) {
+		for (len = 0;
+		     str[len] && str[len] != ':' && str[len] != ')'; len++);
+		if (len == 2 && !strncmp(str, "ro", 2))
+			features |= DASD_FEATURE_READONLY;
+		else if (len == 4 && !strncmp(str, "diag", 4))
+			features |= DASD_FEATURE_USEDIAG;
+		else if (len == 3 && !strncmp(str, "raw", 3))
+			features |= DASD_FEATURE_USERAW;
+		else if (len == 6 && !strncmp(str, "erplog", 6))
+			features |= DASD_FEATURE_ERPLOG;
+		else if (len == 8 && !strncmp(str, "failfast", 8))
+			features |= DASD_FEATURE_FAILFAST;
+		else {
+			pr_warn("%*s is not a supported device option\n",
+				len, str);
+			rc = -EINVAL;
+		}
+		str += len;
+		if (*str != ':')
+			break;
+		str++;
+	}
+
+	return rc ? : features;
+}
+
+/*
+ * Try to match the first element on the comma separated parse string
+ * with one of the known keywords. If a keyword is found, take the approprate
+ * action and return a pointer to the residual string. If the first element
+ * could not be matched to any keyword then return an error code.
+ */
+static int __init dasd_parse_keyword(char *keyword)
+{
+	int length = strlen(keyword);
+
+	if (strncmp("autodetect", keyword, length) == 0) {
+		dasd_autodetect = 1;
+		pr_info("The autodetection mode has been activated\n");
+		return 0;
+        }
+	if (strncmp("probeonly", keyword, length) == 0) {
+		dasd_probeonly = 1;
+		pr_info("The probeonly mode has been activated\n");
+		return 0;
+        }
+	if (strncmp("nopav", keyword, length) == 0) {
+		if (MACHINE_IS_VM)
+			pr_info("'nopav' is not supported on z/VM\n");
+		else {
+			dasd_nopav = 1;
+			pr_info("PAV support has be deactivated\n");
+		}
+		return 0;
+	}
+	if (strncmp("nofcx", keyword, length) == 0) {
+		dasd_nofcx = 1;
+		pr_info("High Performance FICON support has been "
+			"deactivated\n");
+		return 0;
+	}
+	if (strncmp("fixedbuffers", keyword, length) == 0) {
+		if (dasd_page_cache)
+			return 0;
+		dasd_page_cache =
+			kmem_cache_create("dasd_page_cache", PAGE_SIZE,
+					  PAGE_SIZE, SLAB_CACHE_DMA,
+					  NULL);
+		if (!dasd_page_cache)
+			DBF_EVENT(DBF_WARNING, "%s", "Failed to create slab, "
+				"fixed buffer mode disabled.");
+		else
+			DBF_EVENT(DBF_INFO, "%s",
+				 "turning on fixed buffer mode");
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Split a string of a device range into its pieces and return the from, to, and
+ * feature parts separately.
+ * e.g.:
+ * 0.0.1234-0.0.5678(ro:erplog) -> from: 0.0.1234 to: 0.0.5678 features: ro:erplog
+ * 0.0.8765(raw) -> from: 0.0.8765 to: null features: raw
+ * 0x4321 -> from: 0x4321 to: null features: null
+ */
+static int __init dasd_evaluate_range_param(char *range, char **from_str,
+					    char **to_str, char **features_str)
+{
+	int rc = 0;
+
+	/* Do we have a range or a single device? */
+	if (strchr(range, '-')) {
+		*from_str = strsep(&range, "-");
+		*to_str = strsep(&range, "(");
+		*features_str = strsep(&range, ")");
+	} else {
+		*from_str = strsep(&range, "(");
+		*features_str = strsep(&range, ")");
+	}
+
+	if (*features_str && !range) {
+		pr_warn("A closing parenthesis ')' is missing in the dasd= parameter\n");
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+/*
+ * Try to interprete the range string as a device number or a range of devices.
+ * If the interpretation is successful, create the matching dasd_devmap entries.
+ * If interpretation fails or in case of an error, return an error code.
+ */
+static int __init dasd_parse_range(const char *range)
+{
+	struct dasd_devmap *devmap;
+	int from, from_id0, from_id1;
+	int to, to_id0, to_id1;
+	int features;
+	char bus_id[DASD_BUS_ID_SIZE + 1];
+	char *features_str = NULL;
+	char *from_str = NULL;
+	char *to_str = NULL;
+	int rc = 0;
+	char *tmp;
+
+	tmp = kstrdup(range, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	if (dasd_evaluate_range_param(tmp, &from_str, &to_str, &features_str)) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (dasd_busid(from_str, &from_id0, &from_id1, &from)) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	to = from;
+	to_id0 = from_id0;
+	to_id1 = from_id1;
+	if (to_str) {
+		if (dasd_busid(to_str, &to_id0, &to_id1, &to)) {
+			rc = -EINVAL;
+			goto out;
+		}
+		if (from_id0 != to_id0 || from_id1 != to_id1 || from > to) {
+			pr_err("%s is not a valid device range\n", range);
+			rc = -EINVAL;
+			goto out;
+		}
+	}
+
+	features = dasd_feature_list(features_str);
+	if (features < 0) {
+		rc = -EINVAL;
+		goto out;
+	}
+	/* each device in dasd= parameter should be set initially online */
+	features |= DASD_FEATURE_INITIAL_ONLINE;
+	while (from <= to) {
+		sprintf(bus_id, "%01x.%01x.%04x", from_id0, from_id1, from++);
+		devmap = dasd_add_busid(bus_id, features);
+		if (IS_ERR(devmap)) {
+			rc = PTR_ERR(devmap);
+			goto out;
+		}
+	}
+
+out:
+	kfree(tmp);
+
+	return rc;
+}
+
+/*
+ * Parse parameters stored in dasd[]
+ * The 'dasd=...' parameter allows to specify a comma separated list of
+ * keywords and device ranges. The parameters in that list will be stored as
+ * separate elementes in dasd[].
+ */
+int __init dasd_parse(void)
+{
+	int rc, i;
+	char *cur;
+
+	rc = 0;
+	for (i = 0; i < DASD_MAX_PARAMS; i++) {
+		cur = dasd[i];
+		if (!cur)
+			break;
+		if (*cur == '\0')
+			continue;
+
+		rc = dasd_parse_keyword(cur);
+		if (rc)
+			rc = dasd_parse_range(cur);
+
+		if (rc)
+			break;
+	}
+
+	return rc;
+}
+
+/*
+ * Add a devmap for the device specified by busid. It is possible that
+ * the devmap already exists (dasd= parameter). The order of the devices
+ * added through this function will define the kdevs for the individual
+ * devices.
+ */
+static struct dasd_devmap *
+dasd_add_busid(const char *bus_id, int features)
+{
+	struct dasd_devmap *devmap, *new, *tmp;
+	int hash;
+
+	new = kzalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+	spin_lock(&dasd_devmap_lock);
+	devmap = NULL;
+	hash = dasd_hash_busid(bus_id);
+	list_for_each_entry(tmp, &dasd_hashlists[hash], list)
+		if (strncmp(tmp->bus_id, bus_id, DASD_BUS_ID_SIZE) == 0) {
+			devmap = tmp;
+			break;
+		}
+	if (!devmap) {
+		/* This bus_id is new. */
+		new->devindex = dasd_max_devindex++;
+		strlcpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);
+		new->features = features;
+		new->device = NULL;
+		list_add(&new->list, &dasd_hashlists[hash]);
+		devmap = new;
+		new = NULL;
+	}
+	spin_unlock(&dasd_devmap_lock);
+	kfree(new);
+	return devmap;
+}
+
+/*
+ * Find devmap for device with given bus_id.
+ */
+static struct dasd_devmap *
+dasd_find_busid(const char *bus_id)
+{
+	struct dasd_devmap *devmap, *tmp;
+	int hash;
+
+	spin_lock(&dasd_devmap_lock);
+	devmap = ERR_PTR(-ENODEV);
+	hash = dasd_hash_busid(bus_id);
+	list_for_each_entry(tmp, &dasd_hashlists[hash], list) {
+		if (strncmp(tmp->bus_id, bus_id, DASD_BUS_ID_SIZE) == 0) {
+			devmap = tmp;
+			break;
+		}
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return devmap;
+}
+
+/*
+ * Check if busid has been added to the list of dasd ranges.
+ */
+int
+dasd_busid_known(const char *bus_id)
+{
+	return IS_ERR(dasd_find_busid(bus_id)) ? -ENOENT : 0;
+}
+
+/*
+ * Forget all about the device numbers added so far.
+ * This may only be called at module unload or system shutdown.
+ */
+static void
+dasd_forget_ranges(void)
+{
+	struct dasd_devmap *devmap, *n;
+	int i;
+
+	spin_lock(&dasd_devmap_lock);
+	for (i = 0; i < 256; i++) {
+		list_for_each_entry_safe(devmap, n, &dasd_hashlists[i], list) {
+			BUG_ON(devmap->device != NULL);
+			list_del(&devmap->list);
+			kfree(devmap);
+		}
+	}
+	spin_unlock(&dasd_devmap_lock);
+}
+
+/*
+ * Find the device struct by its device index.
+ */
+struct dasd_device *
+dasd_device_from_devindex(int devindex)
+{
+	struct dasd_devmap *devmap, *tmp;
+	struct dasd_device *device;
+	int i;
+
+	spin_lock(&dasd_devmap_lock);
+	devmap = NULL;
+	for (i = 0; (i < 256) && !devmap; i++)
+		list_for_each_entry(tmp, &dasd_hashlists[i], list)
+			if (tmp->devindex == devindex) {
+				/* Found the devmap for the device. */
+				devmap = tmp;
+				break;
+			}
+	if (devmap && devmap->device) {
+		device = devmap->device;
+		dasd_get_device(device);
+	} else
+		device = ERR_PTR(-ENODEV);
+	spin_unlock(&dasd_devmap_lock);
+	return device;
+}
+
+/*
+ * Return devmap for cdev. If no devmap exists yet, create one and
+ * connect it to the cdev.
+ */
+static struct dasd_devmap *
+dasd_devmap_from_cdev(struct ccw_device *cdev)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(dev_name(&cdev->dev));
+	if (IS_ERR(devmap))
+		devmap = dasd_add_busid(dev_name(&cdev->dev),
+					DASD_FEATURE_DEFAULT);
+	return devmap;
+}
+
+/*
+ * Create a dasd device structure for cdev.
+ */
+struct dasd_device *
+dasd_create_device(struct ccw_device *cdev)
+{
+	struct dasd_devmap *devmap;
+	struct dasd_device *device;
+	unsigned long flags;
+	int rc;
+
+	devmap = dasd_devmap_from_cdev(cdev);
+	if (IS_ERR(devmap))
+		return (void *) devmap;
+
+	device = dasd_alloc_device();
+	if (IS_ERR(device))
+		return device;
+	atomic_set(&device->ref_count, 3);
+
+	spin_lock(&dasd_devmap_lock);
+	if (!devmap->device) {
+		devmap->device = device;
+		device->devindex = devmap->devindex;
+		device->features = devmap->features;
+		get_device(&cdev->dev);
+		device->cdev = cdev;
+		rc = 0;
+	} else
+		/* Someone else was faster. */
+		rc = -EBUSY;
+	spin_unlock(&dasd_devmap_lock);
+
+	if (rc) {
+		dasd_free_device(device);
+		return ERR_PTR(rc);
+	}
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	dev_set_drvdata(&cdev->dev, device);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	return device;
+}
+
+/*
+ * Wait queue for dasd_delete_device waits.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(dasd_delete_wq);
+
+/*
+ * Remove a dasd device structure. The passed referenced
+ * is destroyed.
+ */
+void
+dasd_delete_device(struct dasd_device *device)
+{
+	struct ccw_device *cdev;
+	struct dasd_devmap *devmap;
+	unsigned long flags;
+
+	/* First remove device pointer from devmap. */
+	devmap = dasd_find_busid(dev_name(&device->cdev->dev));
+	BUG_ON(IS_ERR(devmap));
+	spin_lock(&dasd_devmap_lock);
+	if (devmap->device != device) {
+		spin_unlock(&dasd_devmap_lock);
+		dasd_put_device(device);
+		return;
+	}
+	devmap->device = NULL;
+	spin_unlock(&dasd_devmap_lock);
+
+	/* Disconnect dasd_device structure from ccw_device structure. */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	dev_set_drvdata(&device->cdev->dev, NULL);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+	/*
+	 * Drop ref_count by 3, one for the devmap reference, one for
+	 * the cdev reference and one for the passed reference.
+	 */
+	atomic_sub(3, &device->ref_count);
+
+	/* Wait for reference counter to drop to zero. */
+	wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
+
+	dasd_generic_free_discipline(device);
+	/* Disconnect dasd_device structure from ccw_device structure. */
+	cdev = device->cdev;
+	device->cdev = NULL;
+
+	/* Put ccw_device structure. */
+	put_device(&cdev->dev);
+
+	/* Now the device structure can be freed. */
+	dasd_free_device(device);
+}
+
+/*
+ * Reference counter dropped to zero. Wake up waiter
+ * in dasd_delete_device.
+ */
+void
+dasd_put_device_wake(struct dasd_device *device)
+{
+	wake_up(&dasd_delete_wq);
+}
+EXPORT_SYMBOL_GPL(dasd_put_device_wake);
+
+/*
+ * Return dasd_device structure associated with cdev.
+ * This function needs to be called with the ccw device
+ * lock held. It can be used from interrupt context.
+ */
+struct dasd_device *
+dasd_device_from_cdev_locked(struct ccw_device *cdev)
+{
+	struct dasd_device *device = dev_get_drvdata(&cdev->dev);
+
+	if (!device)
+		return ERR_PTR(-ENODEV);
+	dasd_get_device(device);
+	return device;
+}
+
+/*
+ * Return dasd_device structure associated with cdev.
+ */
+struct dasd_device *
+dasd_device_from_cdev(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	device = dasd_device_from_cdev_locked(cdev);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+	return device;
+}
+
+void dasd_add_link_to_gendisk(struct gendisk *gdp, struct dasd_device *device)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(dev_name(&device->cdev->dev));
+	if (IS_ERR(devmap))
+		return;
+	spin_lock(&dasd_devmap_lock);
+	gdp->private_data = devmap;
+	spin_unlock(&dasd_devmap_lock);
+}
+
+struct dasd_device *dasd_device_from_gendisk(struct gendisk *gdp)
+{
+	struct dasd_device *device;
+	struct dasd_devmap *devmap;
+
+	if (!gdp->private_data)
+		return NULL;
+	device = NULL;
+	spin_lock(&dasd_devmap_lock);
+	devmap = gdp->private_data;
+	if (devmap && devmap->device) {
+		device = devmap->device;
+		dasd_get_device(device);
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return device;
+}
+
+/*
+ * SECTION: files in sysfs
+ */
+
+/*
+ * failfast controls the behaviour, if no path is available
+ */
+static ssize_t dasd_ff_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct dasd_devmap *devmap;
+	int ff_flag;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap))
+		ff_flag = (devmap->features & DASD_FEATURE_FAILFAST) != 0;
+	else
+		ff_flag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_FAILFAST) != 0;
+	return snprintf(buf, PAGE_SIZE, ff_flag ? "1\n" : "0\n");
+}
+
+static ssize_t dasd_ff_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	unsigned int val;
+	int rc;
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	rc = dasd_set_feature(to_ccwdev(dev), DASD_FEATURE_FAILFAST, val);
+
+	return rc ? : count;
+}
+
+static DEVICE_ATTR(failfast, 0644, dasd_ff_show, dasd_ff_store);
+
+/*
+ * readonly controls the readonly status of a dasd
+ */
+static ssize_t
+dasd_ro_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	struct dasd_device *device;
+	int ro_flag = 0;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (IS_ERR(devmap))
+		goto out;
+
+	ro_flag = !!(devmap->features & DASD_FEATURE_READONLY);
+
+	spin_lock(&dasd_devmap_lock);
+	device = devmap->device;
+	if (device)
+		ro_flag |= test_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+	spin_unlock(&dasd_devmap_lock);
+
+out:
+	return snprintf(buf, PAGE_SIZE, ro_flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_ro_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	struct ccw_device *cdev = to_ccwdev(dev);
+	struct dasd_device *device;
+	unsigned long flags;
+	unsigned int val;
+	int rc;
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	rc = dasd_set_feature(cdev, DASD_FEATURE_READONLY, val);
+	if (rc)
+		return rc;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device))
+		return count;
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	val = val || test_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+
+	if (!device->block || !device->block->gdp ||
+	    test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		goto out;
+	}
+	/* Increase open_count to avoid losing the block device */
+	atomic_inc(&device->block->open_count);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	set_disk_ro(device->block->gdp, val);
+	atomic_dec(&device->block->open_count);
+
+out:
+	dasd_put_device(device);
+
+	return count;
+}
+
+static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_store);
+/*
+ * erplog controls the logging of ERP related data
+ * (e.g. failing channel programs).
+ */
+static ssize_t
+dasd_erplog_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int erplog;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap))
+		erplog = (devmap->features & DASD_FEATURE_ERPLOG) != 0;
+	else
+		erplog = (DASD_FEATURE_DEFAULT & DASD_FEATURE_ERPLOG) != 0;
+	return snprintf(buf, PAGE_SIZE, erplog ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_erplog_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	unsigned int val;
+	int rc;
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	rc = dasd_set_feature(to_ccwdev(dev), DASD_FEATURE_ERPLOG, val);
+
+	return rc ? : count;
+}
+
+static DEVICE_ATTR(erplog, 0644, dasd_erplog_show, dasd_erplog_store);
+
+/*
+ * use_diag controls whether the driver should use diag rather than ssch
+ * to talk to the device
+ */
+static ssize_t
+dasd_use_diag_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int use_diag;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap))
+		use_diag = (devmap->features & DASD_FEATURE_USEDIAG) != 0;
+	else
+		use_diag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USEDIAG) != 0;
+	return sprintf(buf, use_diag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_use_diag_store(struct device *dev, struct device_attribute *attr,
+		    const char *buf, size_t count)
+{
+	struct dasd_devmap *devmap;
+	unsigned int val;
+	ssize_t rc;
+
+	devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	spin_lock(&dasd_devmap_lock);
+	/* Changing diag discipline flag is only allowed in offline state. */
+	rc = count;
+	if (!devmap->device && !(devmap->features & DASD_FEATURE_USERAW)) {
+		if (val)
+			devmap->features |= DASD_FEATURE_USEDIAG;
+		else
+			devmap->features &= ~DASD_FEATURE_USEDIAG;
+	} else
+		rc = -EPERM;
+	spin_unlock(&dasd_devmap_lock);
+	return rc;
+}
+
+static DEVICE_ATTR(use_diag, 0644, dasd_use_diag_show, dasd_use_diag_store);
+
+/*
+ * use_raw controls whether the driver should give access to raw eckd data or
+ * operate in standard mode
+ */
+static ssize_t
+dasd_use_raw_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int use_raw;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap))
+		use_raw = (devmap->features & DASD_FEATURE_USERAW) != 0;
+	else
+		use_raw = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USERAW) != 0;
+	return sprintf(buf, use_raw ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_use_raw_store(struct device *dev, struct device_attribute *attr,
+		    const char *buf, size_t count)
+{
+	struct dasd_devmap *devmap;
+	ssize_t rc;
+	unsigned long val;
+
+	devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+
+	if ((kstrtoul(buf, 10, &val) != 0) || val > 1)
+		return -EINVAL;
+
+	spin_lock(&dasd_devmap_lock);
+	/* Changing diag discipline flag is only allowed in offline state. */
+	rc = count;
+	if (!devmap->device && !(devmap->features & DASD_FEATURE_USEDIAG)) {
+		if (val)
+			devmap->features |= DASD_FEATURE_USERAW;
+		else
+			devmap->features &= ~DASD_FEATURE_USERAW;
+	} else
+		rc = -EPERM;
+	spin_unlock(&dasd_devmap_lock);
+	return rc;
+}
+
+static DEVICE_ATTR(raw_track_access, 0644, dasd_use_raw_show,
+		   dasd_use_raw_store);
+
+static ssize_t
+dasd_safe_offline_store(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct ccw_device *cdev = to_ccwdev(dev);
+	struct dasd_device *device;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device)) {
+		rc = PTR_ERR(device);
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		goto out;
+	}
+
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
+	    test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/* Already doing offline processing */
+		dasd_put_device(device);
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		rc = -EBUSY;
+		goto out;
+	}
+
+	set_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
+	dasd_put_device(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	rc = ccw_device_set_offline(cdev);
+
+out:
+	return rc ? rc : count;
+}
+
+static DEVICE_ATTR(safe_offline, 0200, NULL, dasd_safe_offline_store);
+
+static ssize_t
+dasd_access_show(struct device *dev, struct device_attribute *attr,
+		 char *buf)
+{
+	struct ccw_device *cdev = to_ccwdev(dev);
+	struct dasd_device *device;
+	int count;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	if (!device->discipline)
+		count = -ENODEV;
+	else if (!device->discipline->host_access_count)
+		count = -EOPNOTSUPP;
+	else
+		count = device->discipline->host_access_count(device);
+
+	dasd_put_device(device);
+	if (count < 0)
+		return count;
+
+	return sprintf(buf, "%d\n", count);
+}
+
+static DEVICE_ATTR(host_access_count, 0444, dasd_access_show, NULL);
+
+static ssize_t
+dasd_discipline_show(struct device *dev, struct device_attribute *attr,
+		     char *buf)
+{
+	struct dasd_device *device;
+	ssize_t len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		goto out;
+	else if (!device->discipline) {
+		dasd_put_device(device);
+		goto out;
+	} else {
+		len = snprintf(buf, PAGE_SIZE, "%s\n",
+			       device->discipline->name);
+		dasd_put_device(device);
+		return len;
+	}
+out:
+	len = snprintf(buf, PAGE_SIZE, "none\n");
+	return len;
+}
+
+static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);
+
+static ssize_t
+dasd_device_status_show(struct device *dev, struct device_attribute *attr,
+		     char *buf)
+{
+	struct dasd_device *device;
+	ssize_t len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (!IS_ERR(device)) {
+		switch (device->state) {
+		case DASD_STATE_NEW:
+			len = snprintf(buf, PAGE_SIZE, "new\n");
+			break;
+		case DASD_STATE_KNOWN:
+			len = snprintf(buf, PAGE_SIZE, "detected\n");
+			break;
+		case DASD_STATE_BASIC:
+			len = snprintf(buf, PAGE_SIZE, "basic\n");
+			break;
+		case DASD_STATE_UNFMT:
+			len = snprintf(buf, PAGE_SIZE, "unformatted\n");
+			break;
+		case DASD_STATE_READY:
+			len = snprintf(buf, PAGE_SIZE, "ready\n");
+			break;
+		case DASD_STATE_ONLINE:
+			len = snprintf(buf, PAGE_SIZE, "online\n");
+			break;
+		default:
+			len = snprintf(buf, PAGE_SIZE, "no stat\n");
+			break;
+		}
+		dasd_put_device(device);
+	} else
+		len = snprintf(buf, PAGE_SIZE, "unknown\n");
+	return len;
+}
+
+static DEVICE_ATTR(status, 0444, dasd_device_status_show, NULL);
+
+static ssize_t dasd_alias_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	struct dasd_uid uid;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return sprintf(buf, "0\n");
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid)) {
+		if (uid.type == UA_BASE_PAV_ALIAS ||
+		    uid.type == UA_HYPER_PAV_ALIAS) {
+			dasd_put_device(device);
+			return sprintf(buf, "1\n");
+		}
+	}
+	dasd_put_device(device);
+
+	return sprintf(buf, "0\n");
+}
+
+static DEVICE_ATTR(alias, 0444, dasd_alias_show, NULL);
+
+static ssize_t dasd_vendor_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	struct dasd_uid uid;
+	char *vendor;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	vendor = "";
+	if (IS_ERR(device))
+		return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid))
+			vendor = uid.vendor;
+
+	dasd_put_device(device);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
+}
+
+static DEVICE_ATTR(vendor, 0444, dasd_vendor_show, NULL);
+
+#define UID_STRLEN ( /* vendor */ 3 + 1 + /* serial    */ 14 + 1 +\
+		     /* SSID   */ 4 + 1 + /* unit addr */ 2 + 1 +\
+		     /* vduit */ 32 + 1)
+
+static ssize_t
+dasd_uid_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	struct dasd_uid uid;
+	char uid_string[UID_STRLEN];
+	char ua_string[3];
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	uid_string[0] = 0;
+	if (IS_ERR(device))
+		return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);
+
+	if (device->discipline && device->discipline->get_uid &&
+	    !device->discipline->get_uid(device, &uid)) {
+		switch (uid.type) {
+		case UA_BASE_DEVICE:
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.real_unit_addr);
+			break;
+		case UA_BASE_PAV_ALIAS:
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.base_unit_addr);
+			break;
+		case UA_HYPER_PAV_ALIAS:
+			snprintf(ua_string, sizeof(ua_string), "xx");
+			break;
+		default:
+			/* should not happen, treat like base device */
+			snprintf(ua_string, sizeof(ua_string), "%02x",
+				 uid.real_unit_addr);
+			break;
+		}
+
+		if (strlen(uid.vduit) > 0)
+			snprintf(uid_string, sizeof(uid_string),
+				 "%s.%s.%04x.%s.%s",
+				 uid.vendor, uid.serial, uid.ssid, ua_string,
+				 uid.vduit);
+		else
+			snprintf(uid_string, sizeof(uid_string),
+				 "%s.%s.%04x.%s",
+				 uid.vendor, uid.serial, uid.ssid, ua_string);
+	}
+	dasd_put_device(device);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);
+}
+static DEVICE_ATTR(uid, 0444, dasd_uid_show, NULL);
+
+/*
+ * extended error-reporting
+ */
+static ssize_t
+dasd_eer_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int eer_flag;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap) && devmap->device)
+		eer_flag = dasd_eer_enabled(devmap->device);
+	else
+		eer_flag = 0;
+	return snprintf(buf, PAGE_SIZE, eer_flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_eer_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned int val;
+	int rc = 0;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	if (val)
+		rc = dasd_eer_enable(device);
+	else
+		dasd_eer_disable(device);
+
+	dasd_put_device(device);
+
+	return rc ? : count;
+}
+
+static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);
+
+/*
+ * expiration time for default requests
+ */
+static ssize_t
+dasd_expires_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_expires);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_expires_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if ((kstrtoul(buf, 10, &val) != 0) ||
+	    (val > DASD_EXPIRES_MAX) || val == 0) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+
+	if (val)
+		device->default_expires = val;
+
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(expires, 0644, dasd_expires_show, dasd_expires_store);
+
+static ssize_t
+dasd_retries_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_retries);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_retries_store(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if ((kstrtoul(buf, 10, &val) != 0) ||
+	    (val > DASD_RETRIES_MAX)) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+
+	if (val)
+		device->default_retries = val;
+
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(retries, 0644, dasd_retries_show, dasd_retries_store);
+
+static ssize_t
+dasd_timeout_show(struct device *dev, struct device_attribute *attr,
+		  char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->blk_timeout);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_timeout_store(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	struct request_queue *q;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device) || !device->block)
+		return -ENODEV;
+
+	if ((kstrtoul(buf, 10, &val) != 0) ||
+	    val > UINT_MAX / HZ) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+	q = device->block->request_queue;
+	if (!q) {
+		dasd_put_device(device);
+		return -ENODEV;
+	}
+
+	device->blk_timeout = val;
+
+	blk_queue_rq_timeout(q, device->blk_timeout * HZ);
+
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(timeout, 0644,
+		   dasd_timeout_show, dasd_timeout_store);
+
+
+static ssize_t
+dasd_path_reset_store(struct device *dev, struct device_attribute *attr,
+		      const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned int val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if ((kstrtouint(buf, 16, &val) != 0) || val > 0xff)
+		val = 0;
+
+	if (device->discipline && device->discipline->reset_path)
+		device->discipline->reset_path(device, (__u8) val);
+
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(path_reset, 0200, NULL, dasd_path_reset_store);
+
+static ssize_t dasd_hpf_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct dasd_device *device;
+	int hpf;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	if (!device->discipline || !device->discipline->hpf_enabled) {
+		dasd_put_device(device);
+		return snprintf(buf, PAGE_SIZE, "%d\n", dasd_nofcx);
+	}
+	hpf = device->discipline->hpf_enabled(device);
+	dasd_put_device(device);
+	return snprintf(buf, PAGE_SIZE, "%d\n", hpf);
+}
+
+static DEVICE_ATTR(hpf, 0444, dasd_hpf_show, NULL);
+
+static ssize_t dasd_reservation_policy_show(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf)
+{
+	struct dasd_devmap *devmap;
+	int rc = 0;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (IS_ERR(devmap)) {
+		rc = snprintf(buf, PAGE_SIZE, "ignore\n");
+	} else {
+		spin_lock(&dasd_devmap_lock);
+		if (devmap->features & DASD_FEATURE_FAILONSLCK)
+			rc = snprintf(buf, PAGE_SIZE, "fail\n");
+		else
+			rc = snprintf(buf, PAGE_SIZE, "ignore\n");
+		spin_unlock(&dasd_devmap_lock);
+	}
+	return rc;
+}
+
+static ssize_t dasd_reservation_policy_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	struct ccw_device *cdev = to_ccwdev(dev);
+	int rc;
+
+	if (sysfs_streq("ignore", buf))
+		rc = dasd_set_feature(cdev, DASD_FEATURE_FAILONSLCK, 0);
+	else if (sysfs_streq("fail", buf))
+		rc = dasd_set_feature(cdev, DASD_FEATURE_FAILONSLCK, 1);
+	else
+		rc = -EINVAL;
+
+	return rc ? : count;
+}
+
+static DEVICE_ATTR(reservation_policy, 0644,
+		   dasd_reservation_policy_show, dasd_reservation_policy_store);
+
+static ssize_t dasd_reservation_state_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct dasd_device *device;
+	int rc = 0;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return snprintf(buf, PAGE_SIZE, "none\n");
+
+	if (test_bit(DASD_FLAG_IS_RESERVED, &device->flags))
+		rc = snprintf(buf, PAGE_SIZE, "reserved\n");
+	else if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags))
+		rc = snprintf(buf, PAGE_SIZE, "lost\n");
+	else
+		rc = snprintf(buf, PAGE_SIZE, "none\n");
+	dasd_put_device(device);
+	return rc;
+}
+
+static ssize_t dasd_reservation_state_store(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	int rc = 0;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	if (sysfs_streq("reset", buf))
+		clear_bit(DASD_FLAG_LOCK_STOLEN, &device->flags);
+	else
+		rc = -EINVAL;
+	dasd_put_device(device);
+
+	if (rc)
+		return rc;
+	else
+		return count;
+}
+
+static DEVICE_ATTR(last_known_reservation_state, 0644,
+		   dasd_reservation_state_show, dasd_reservation_state_store);
+
+static ssize_t dasd_pm_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	u8 opm, nppm, cablepm, cuirpm, hpfpm, ifccpm;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return sprintf(buf, "0\n");
+
+	opm = dasd_path_get_opm(device);
+	nppm = dasd_path_get_nppm(device);
+	cablepm = dasd_path_get_cablepm(device);
+	cuirpm = dasd_path_get_cuirpm(device);
+	hpfpm = dasd_path_get_hpfpm(device);
+	ifccpm = dasd_path_get_ifccpm(device);
+	dasd_put_device(device);
+
+	return sprintf(buf, "%02x %02x %02x %02x %02x %02x\n", opm, nppm,
+		       cablepm, cuirpm, hpfpm, ifccpm);
+}
+
+static DEVICE_ATTR(path_masks, 0444, dasd_pm_show, NULL);
+
+/*
+ * threshold value for IFCC/CCC errors
+ */
+static ssize_t
+dasd_path_threshold_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->path_thrhld);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_path_threshold_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if (kstrtoul(buf, 10, &val) != 0 || val > DASD_THRHLD_MAX) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+	spin_lock_irqsave(get_ccwdev_lock(to_ccwdev(dev)), flags);
+	device->path_thrhld = val;
+	spin_unlock_irqrestore(get_ccwdev_lock(to_ccwdev(dev)), flags);
+	dasd_put_device(device);
+	return count;
+}
+static DEVICE_ATTR(path_threshold, 0644, dasd_path_threshold_show,
+		   dasd_path_threshold_store);
+
+/*
+ * configure if path is disabled after IFCC/CCC error threshold is
+ * exceeded
+ */
+static ssize_t
+dasd_path_autodisable_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int flag;
+
+	devmap = dasd_find_busid(dev_name(dev));
+	if (!IS_ERR(devmap))
+		flag = (devmap->features & DASD_FEATURE_PATH_AUTODISABLE) != 0;
+	else
+		flag = (DASD_FEATURE_DEFAULT &
+			DASD_FEATURE_PATH_AUTODISABLE) != 0;
+	return snprintf(buf, PAGE_SIZE, flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_path_autodisable_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	unsigned int val;
+	int rc;
+
+	if (kstrtouint(buf, 0, &val) || val > 1)
+		return -EINVAL;
+
+	rc = dasd_set_feature(to_ccwdev(dev),
+			      DASD_FEATURE_PATH_AUTODISABLE, val);
+
+	return rc ? : count;
+}
+
+static DEVICE_ATTR(path_autodisable, 0644,
+		   dasd_path_autodisable_show,
+		   dasd_path_autodisable_store);
+/*
+ * interval for IFCC/CCC checks
+ * meaning time with no IFCC/CCC error before the error counter
+ * gets reset
+ */
+static ssize_t
+dasd_path_interval_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	int len;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	len = snprintf(buf, PAGE_SIZE, "%lu\n", device->path_interval);
+	dasd_put_device(device);
+	return len;
+}
+
+static ssize_t
+dasd_path_interval_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+	unsigned long val;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+
+	if ((kstrtoul(buf, 10, &val) != 0) ||
+	    (val > DASD_INTERVAL_MAX) || val == 0) {
+		dasd_put_device(device);
+		return -EINVAL;
+	}
+	spin_lock_irqsave(get_ccwdev_lock(to_ccwdev(dev)), flags);
+	if (val)
+		device->path_interval = val;
+	spin_unlock_irqrestore(get_ccwdev_lock(to_ccwdev(dev)), flags);
+	dasd_put_device(device);
+	return count;
+}
+
+static DEVICE_ATTR(path_interval, 0644, dasd_path_interval_show,
+		   dasd_path_interval_store);
+
+
+static struct attribute * dasd_attrs[] = {
+	&dev_attr_readonly.attr,
+	&dev_attr_discipline.attr,
+	&dev_attr_status.attr,
+	&dev_attr_alias.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_uid.attr,
+	&dev_attr_use_diag.attr,
+	&dev_attr_raw_track_access.attr,
+	&dev_attr_eer_enabled.attr,
+	&dev_attr_erplog.attr,
+	&dev_attr_failfast.attr,
+	&dev_attr_expires.attr,
+	&dev_attr_retries.attr,
+	&dev_attr_timeout.attr,
+	&dev_attr_reservation_policy.attr,
+	&dev_attr_last_known_reservation_state.attr,
+	&dev_attr_safe_offline.attr,
+	&dev_attr_host_access_count.attr,
+	&dev_attr_path_masks.attr,
+	&dev_attr_path_threshold.attr,
+	&dev_attr_path_autodisable.attr,
+	&dev_attr_path_interval.attr,
+	&dev_attr_path_reset.attr,
+	&dev_attr_hpf.attr,
+	NULL,
+};
+
+static const struct attribute_group dasd_attr_group = {
+	.attrs = dasd_attrs,
+};
+
+/*
+ * Return value of the specified feature.
+ */
+int
+dasd_get_feature(struct ccw_device *cdev, int feature)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(dev_name(&cdev->dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+
+	return ((devmap->features & feature) != 0);
+}
+
+/*
+ * Set / reset given feature.
+ * Flag indicates whether to set (!=0) or the reset (=0) the feature.
+ */
+int
+dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_devmap_from_cdev(cdev);
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+
+	spin_lock(&dasd_devmap_lock);
+	if (flag)
+		devmap->features |= feature;
+	else
+		devmap->features &= ~feature;
+	if (devmap->device)
+		devmap->device->features = devmap->features;
+	spin_unlock(&dasd_devmap_lock);
+	return 0;
+}
+EXPORT_SYMBOL(dasd_set_feature);
+
+
+int
+dasd_add_sysfs_files(struct ccw_device *cdev)
+{
+	return sysfs_create_group(&cdev->dev.kobj, &dasd_attr_group);
+}
+
+void
+dasd_remove_sysfs_files(struct ccw_device *cdev)
+{
+	sysfs_remove_group(&cdev->dev.kobj, &dasd_attr_group);
+}
+
+
+int
+dasd_devmap_init(void)
+{
+	int i;
+
+	/* Initialize devmap structures. */
+	dasd_max_devindex = 0;
+	for (i = 0; i < 256; i++)
+		INIT_LIST_HEAD(&dasd_hashlists[i]);
+	return 0;
+}
+
+void
+dasd_devmap_exit(void)
+{
+	dasd_forget_ranges();
+}
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
new file mode 100644
index 000000000..e1fe02477
--- /dev/null
+++ b/drivers/s390/block/dasd_diag.c
@@ -0,0 +1,662 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Based on.......: linux/drivers/s390/block/mdisk.c
+ * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2000
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/kernel_stat.h>
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/hdreg.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+
+#include <asm/dasd.h>
+#include <asm/debug.h>
+#include <asm/diag.h>
+#include <asm/ebcdic.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/vtoc.h>
+
+#include "dasd_int.h"
+#include "dasd_diag.h"
+
+#define PRINTK_HEADER "dasd(diag):"
+
+MODULE_LICENSE("GPL");
+
+/* The maximum number of blocks per request (max_blocks) is dependent on the
+ * amount of storage that is available in the static I/O buffer for each
+ * device. Currently each device gets 2 pages. We want to fit two requests
+ * into the available memory so that we can immediately start the next if one
+ * finishes. */
+#define DIAG_MAX_BLOCKS	(((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
+			   sizeof(struct dasd_diag_req)) / \
+		           sizeof(struct dasd_diag_bio)) / 2)
+#define DIAG_MAX_RETRIES	32
+#define DIAG_TIMEOUT		50
+
+static struct dasd_discipline dasd_diag_discipline;
+
+struct dasd_diag_private {
+	struct dasd_diag_characteristics rdc_data;
+	struct dasd_diag_rw_io iob;
+	struct dasd_diag_init_io iib;
+	blocknum_t pt_block;
+	struct ccw_dev_id dev_id;
+};
+
+struct dasd_diag_req {
+	unsigned int block_count;
+	struct dasd_diag_bio bio[0];
+};
+
+static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
+
+/* Perform DIAG250 call with block I/O parameter list iob (input and output)
+ * and function code cmd.
+ * In case of an exception return 3. Otherwise return result of bitwise OR of
+ * resulting condition code and DIAG return code. */
+static inline int __dia250(void *iob, int cmd)
+{
+	register unsigned long reg2 asm ("2") = (unsigned long) iob;
+	typedef union {
+		struct dasd_diag_init_io init_io;
+		struct dasd_diag_rw_io rw_io;
+	} addr_type;
+	int rc;
+
+	rc = 3;
+	asm volatile(
+		"	diag	2,%2,0x250\n"
+		"0:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"	or	%0,3\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+d" (rc), "=m" (*(addr_type *) iob)
+		: "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
+		: "3", "cc");
+	return rc;
+}
+
+static inline int dia250(void *iob, int cmd)
+{
+	diag_stat_inc(DIAG_STAT_X250);
+	return __dia250(iob, cmd);
+}
+
+/* Initialize block I/O to DIAG device using the specified blocksize and
+ * block offset. On success, return zero and set end_block to contain the
+ * number of blocks on the device minus the specified offset. Return non-zero
+ * otherwise. */
+static inline int
+mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
+	     blocknum_t offset, blocknum_t *end_block)
+{
+	struct dasd_diag_private *private = device->private;
+	struct dasd_diag_init_io *iib = &private->iib;
+	int rc;
+
+	memset(iib, 0, sizeof (struct dasd_diag_init_io));
+
+	iib->dev_nr = private->dev_id.devno;
+	iib->block_size = blocksize;
+	iib->offset = offset;
+	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
+
+	rc = dia250(iib, INIT_BIO);
+
+	if ((rc & 3) == 0 && end_block)
+		*end_block = iib->end_block;
+
+	return rc;
+}
+
+/* Remove block I/O environment for device. Return zero on success, non-zero
+ * otherwise. */
+static inline int
+mdsk_term_io(struct dasd_device * device)
+{
+	struct dasd_diag_private *private = device->private;
+	struct dasd_diag_init_io *iib = &private->iib;
+	int rc;
+
+	memset(iib, 0, sizeof (struct dasd_diag_init_io));
+	iib->dev_nr = private->dev_id.devno;
+	rc = dia250(iib, TERM_BIO);
+	return rc;
+}
+
+/* Error recovery for failed DIAG requests - try to reestablish the DIAG
+ * environment. */
+static void
+dasd_diag_erp(struct dasd_device *device)
+{
+	int rc;
+
+	mdsk_term_io(device);
+	rc = mdsk_init_io(device, device->block->bp_block, 0, NULL);
+	if (rc == 4) {
+		if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
+			pr_warn("%s: The access mode of a DIAG device changed to read-only\n",
+				dev_name(&device->cdev->dev));
+		rc = 0;
+	}
+	if (rc)
+		pr_warn("%s: DIAG ERP failed with rc=%d\n",
+			dev_name(&device->cdev->dev), rc);
+}
+
+/* Start a given request at the device. Return zero on success, non-zero
+ * otherwise. */
+static int
+dasd_start_diag(struct dasd_ccw_req * cqr)
+{
+	struct dasd_device *device;
+	struct dasd_diag_private *private;
+	struct dasd_diag_req *dreq;
+	int rc;
+
+	device = cqr->startdev;
+	if (cqr->retries < 0) {
+		DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
+			    "- no retry left)", cqr);
+		cqr->status = DASD_CQR_ERROR;
+		return -EIO;
+	}
+	private = device->private;
+	dreq = cqr->data;
+
+	private->iob.dev_nr = private->dev_id.devno;
+	private->iob.key = 0;
+	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
+	private->iob.block_count = dreq->block_count;
+	private->iob.interrupt_params = (addr_t) cqr;
+	private->iob.bio_list = dreq->bio;
+	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
+
+	cqr->startclk = get_tod_clock();
+	cqr->starttime = jiffies;
+	cqr->retries--;
+
+	rc = dia250(&private->iob, RW_BIO);
+	switch (rc) {
+	case 0: /* Synchronous I/O finished successfully */
+		cqr->stopclk = get_tod_clock();
+		cqr->status = DASD_CQR_SUCCESS;
+		/* Indicate to calling function that only a dasd_schedule_bh()
+		   and no timer is needed */
+                rc = -EACCES;
+		break;
+	case 8: /* Asynchronous I/O was started */
+		cqr->status = DASD_CQR_IN_IO;
+		rc = 0;
+		break;
+	default: /* Error condition */
+		cqr->status = DASD_CQR_QUEUED;
+		DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
+		dasd_diag_erp(device);
+		rc = -EIO;
+		break;
+	}
+	cqr->intrc = rc;
+	return rc;
+}
+
+/* Terminate given request at the device. */
+static int
+dasd_diag_term_IO(struct dasd_ccw_req * cqr)
+{
+	struct dasd_device *device;
+
+	device = cqr->startdev;
+	mdsk_term_io(device);
+	mdsk_init_io(device, device->block->bp_block, 0, NULL);
+	cqr->status = DASD_CQR_CLEAR_PENDING;
+	cqr->stopclk = get_tod_clock();
+	dasd_schedule_device_bh(device);
+	return 0;
+}
+
+/* Handle external interruption. */
+static void dasd_ext_handler(struct ext_code ext_code,
+			     unsigned int param32, unsigned long param64)
+{
+	struct dasd_ccw_req *cqr, *next;
+	struct dasd_device *device;
+	unsigned long expires;
+	unsigned long flags;
+	addr_t ip;
+	int rc;
+
+	switch (ext_code.subcode >> 8) {
+	case DASD_DIAG_CODE_31BIT:
+		ip = (addr_t) param32;
+		break;
+	case DASD_DIAG_CODE_64BIT:
+		ip = (addr_t) param64;
+		break;
+	default:
+		return;
+	}
+	inc_irq_stat(IRQEXT_DSD);
+	if (!ip) {		/* no intparm: unsolicited interrupt */
+		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
+			      "interrupt");
+		return;
+	}
+	cqr = (struct dasd_ccw_req *) ip;
+	device = (struct dasd_device *) cqr->startdev;
+	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			    " magic number of dasd_ccw_req 0x%08X doesn't"
+			    " match discipline 0x%08X",
+			    cqr->magic, *(int *) (&device->discipline->name));
+		return;
+	}
+
+	/* get irq lock to modify request queue */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+
+	/* Check for a pending clear operation */
+	if (cqr->status == DASD_CQR_CLEAR_PENDING) {
+		cqr->status = DASD_CQR_CLEARED;
+		dasd_device_clear_timer(device);
+		dasd_schedule_device_bh(device);
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+		return;
+	}
+
+	cqr->stopclk = get_tod_clock();
+
+	expires = 0;
+	if ((ext_code.subcode & 0xff) == 0) {
+		cqr->status = DASD_CQR_SUCCESS;
+		/* Start first request on queue if possible -> fast_io. */
+		if (!list_empty(&device->ccw_queue)) {
+			next = list_entry(device->ccw_queue.next,
+					  struct dasd_ccw_req, devlist);
+			if (next->status == DASD_CQR_QUEUED) {
+				rc = dasd_start_diag(next);
+				if (rc == 0)
+					expires = next->expires;
+			}
+		}
+	} else {
+		cqr->status = DASD_CQR_QUEUED;
+		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
+			      "request %p was %d (%d retries left)", cqr,
+			      ext_code.subcode & 0xff, cqr->retries);
+		dasd_diag_erp(device);
+	}
+
+	if (expires != 0)
+		dasd_device_set_timer(device, expires);
+	else
+		dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+
+/* Check whether device can be controlled by DIAG discipline. Return zero on
+ * success, non-zero otherwise. */
+static int
+dasd_diag_check_device(struct dasd_device *device)
+{
+	struct dasd_diag_private *private = device->private;
+	struct dasd_diag_characteristics *rdc_data;
+	struct vtoc_cms_label *label;
+	struct dasd_block *block;
+	struct dasd_diag_bio bio;
+	unsigned int sb, bsize;
+	blocknum_t end_block;
+	int rc;
+
+	if (private == NULL) {
+		private = kzalloc(sizeof(*private), GFP_KERNEL);
+		if (private == NULL) {
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				"Allocating memory for private DASD data "
+				      "failed\n");
+			return -ENOMEM;
+		}
+		ccw_device_get_id(device->cdev, &private->dev_id);
+		device->private = private;
+	}
+	block = dasd_alloc_block();
+	if (IS_ERR(block)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "could not allocate dasd block structure");
+		device->private = NULL;
+		kfree(private);
+		return PTR_ERR(block);
+	}
+	device->block = block;
+	block->base = device;
+
+	/* Read Device Characteristics */
+	rdc_data = &private->rdc_data;
+	rdc_data->dev_nr = private->dev_id.devno;
+	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
+
+	rc = diag210((struct diag210 *) rdc_data);
+	if (rc) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
+			    "information (rc=%d)", rc);
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	device->default_expires = DIAG_TIMEOUT;
+	device->default_retries = DIAG_MAX_RETRIES;
+
+	/* Figure out position of label block */
+	switch (private->rdc_data.vdev_class) {
+	case DEV_CLASS_FBA:
+		private->pt_block = 1;
+		break;
+	case DEV_CLASS_ECKD:
+		private->pt_block = 2;
+		break;
+	default:
+		pr_warn("%s: Device type %d is not supported in DIAG mode\n",
+			dev_name(&device->cdev->dev),
+			private->rdc_data.vdev_class);
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	DBF_DEV_EVENT(DBF_INFO, device,
+		      "%04X: %04X on real %04X/%02X",
+		      rdc_data->dev_nr,
+		      rdc_data->vdev_type,
+		      rdc_data->rdev_type, rdc_data->rdev_model);
+
+	/* terminate all outstanding operations */
+	mdsk_term_io(device);
+
+	/* figure out blocksize of device */
+	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
+	if (label == NULL)  {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "No memory to allocate initialization request");
+		rc = -ENOMEM;
+		goto out;
+	}
+	rc = 0;
+	end_block = 0;
+	/* try all sizes - needed for ECKD devices */
+	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
+		mdsk_init_io(device, bsize, 0, &end_block);
+		memset(&bio, 0, sizeof (struct dasd_diag_bio));
+		bio.type = MDSK_READ_REQ;
+		bio.block_number = private->pt_block + 1;
+		bio.buffer = label;
+		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
+		private->iob.dev_nr = rdc_data->dev_nr;
+		private->iob.key = 0;
+		private->iob.flags = 0;	/* do synchronous io */
+		private->iob.block_count = 1;
+		private->iob.interrupt_params = 0;
+		private->iob.bio_list = &bio;
+		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
+		rc = dia250(&private->iob, RW_BIO);
+		if (rc == 3) {
+			pr_warn("%s: A 64-bit DIAG call failed\n",
+				dev_name(&device->cdev->dev));
+			rc = -EOPNOTSUPP;
+			goto out_label;
+		}
+		mdsk_term_io(device);
+		if (rc == 0)
+			break;
+	}
+	if (bsize > PAGE_SIZE) {
+		pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n",
+			dev_name(&device->cdev->dev), rc);
+		rc = -EIO;
+		goto out_label;
+	}
+	/* check for label block */
+	if (memcmp(label->label_id, DASD_DIAG_CMS1,
+		  sizeof(DASD_DIAG_CMS1)) == 0) {
+		/* get formatted blocksize from label block */
+		bsize = (unsigned int) label->block_size;
+		block->blocks = (unsigned long) label->block_count;
+	} else
+		block->blocks = end_block;
+	block->bp_block = bsize;
+	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
+	for (sb = 512; sb < bsize; sb = sb << 1)
+		block->s2b_shift++;
+	rc = mdsk_init_io(device, block->bp_block, 0, NULL);
+	if (rc && (rc != 4)) {
+		pr_warn("%s: DIAG initialization failed with rc=%d\n",
+			dev_name(&device->cdev->dev), rc);
+		rc = -EIO;
+	} else {
+		if (rc == 4)
+			set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+		pr_info("%s: New DASD with %ld byte/block, total size %ld "
+			"KB%s\n", dev_name(&device->cdev->dev),
+			(unsigned long) block->bp_block,
+			(unsigned long) (block->blocks <<
+					 block->s2b_shift) >> 1,
+			(rc == 4) ? ", read-only device" : "");
+		rc = 0;
+	}
+out_label:
+	free_page((long) label);
+out:
+	if (rc) {
+		device->block = NULL;
+		dasd_free_block(block);
+		device->private = NULL;
+		kfree(private);
+	}
+	return rc;
+}
+
+/* Fill in virtual disk geometry for device. Return zero on success, non-zero
+ * otherwise. */
+static int
+dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
+{
+	if (dasd_check_blocksize(block->bp_block) != 0)
+		return -EINVAL;
+	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
+	geo->heads = 16;
+	geo->sectors = 128 >> block->s2b_shift;
+	return 0;
+}
+
+static dasd_erp_fn_t
+dasd_diag_erp_action(struct dasd_ccw_req * cqr)
+{
+	return dasd_default_erp_action;
+}
+
+static dasd_erp_fn_t
+dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
+{
+	return dasd_default_erp_postaction;
+}
+
+/* Create DASD request from block device request. Return pointer to new
+ * request on success, ERR_PTR otherwise. */
+static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
+					       struct dasd_block *block,
+					       struct request *req)
+{
+	struct dasd_ccw_req *cqr;
+	struct dasd_diag_req *dreq;
+	struct dasd_diag_bio *dbio;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst;
+	unsigned int count, datasize;
+	sector_t recid, first_rec, last_rec;
+	unsigned int blksize, off;
+	unsigned char rw_cmd;
+
+	if (rq_data_dir(req) == READ)
+		rw_cmd = MDSK_READ_REQ;
+	else if (rq_data_dir(req) == WRITE)
+		rw_cmd = MDSK_WRITE_REQ;
+	else
+		return ERR_PTR(-EINVAL);
+	blksize = block->bp_block;
+	/* Calculate record id of first and last block. */
+	first_rec = blk_rq_pos(req) >> block->s2b_shift;
+	last_rec =
+		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
+	/* Check struct bio and count the number of blocks for the request. */
+	count = 0;
+	rq_for_each_segment(bv, req, iter) {
+		if (bv.bv_len & (blksize - 1))
+			/* Fba can only do full blocks. */
+			return ERR_PTR(-EINVAL);
+		count += bv.bv_len >> (block->s2b_shift + 9);
+	}
+	/* Paranoia. */
+	if (count != last_rec - first_rec + 1)
+		return ERR_PTR(-EINVAL);
+	/* Build the request */
+	datasize = sizeof(struct dasd_diag_req) +
+		count*sizeof(struct dasd_diag_bio);
+	cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev,
+				   blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+
+	dreq = (struct dasd_diag_req *) cqr->data;
+	dreq->block_count = count;
+	dbio = dreq->bio;
+	recid = first_rec;
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
+			memset(dbio, 0, sizeof (struct dasd_diag_bio));
+			dbio->type = rw_cmd;
+			dbio->block_number = recid + 1;
+			dbio->buffer = dst;
+			dbio++;
+			dst += blksize;
+			recid++;
+		}
+	}
+	cqr->retries = memdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->startdev = memdev;
+	cqr->memdev = memdev;
+	cqr->block = block;
+	cqr->expires = memdev->default_expires * HZ;
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+/* Release DASD request. Return non-zero if request was successful, zero
+ * otherwise. */
+static int
+dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
+{
+	int status;
+
+	status = cqr->status == DASD_CQR_DONE;
+	dasd_sfree_request(cqr, cqr->memdev);
+	return status;
+}
+
+static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
+{
+	if (cqr->retries < 0)
+		cqr->status = DASD_CQR_FAILED;
+	else
+		cqr->status = DASD_CQR_FILLED;
+};
+
+/* Fill in IOCTL data for device. */
+static int
+dasd_diag_fill_info(struct dasd_device * device,
+		    struct dasd_information2_t * info)
+{
+	struct dasd_diag_private *private = device->private;
+
+	info->label_block = (unsigned int) private->pt_block;
+	info->FBA_layout = 1;
+	info->format = DASD_FORMAT_LDL;
+	info->characteristics_size = sizeof(private->rdc_data);
+	memcpy(info->characteristics, &private->rdc_data,
+	       sizeof(private->rdc_data));
+	info->confdata_size = 0;
+	return 0;
+}
+
+static void
+dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
+		     struct irb *stat)
+{
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+		    "dump sense not available for DIAG data");
+}
+
+static struct dasd_discipline dasd_diag_discipline = {
+	.owner = THIS_MODULE,
+	.name = "DIAG",
+	.ebcname = "DIAG",
+	.max_blocks = DIAG_MAX_BLOCKS,
+	.check_device = dasd_diag_check_device,
+	.verify_path = dasd_generic_verify_path,
+	.fill_geometry = dasd_diag_fill_geometry,
+	.start_IO = dasd_start_diag,
+	.term_IO = dasd_diag_term_IO,
+	.handle_terminated_request = dasd_diag_handle_terminated_request,
+	.erp_action = dasd_diag_erp_action,
+	.erp_postaction = dasd_diag_erp_postaction,
+	.build_cp = dasd_diag_build_cp,
+	.free_cp = dasd_diag_free_cp,
+	.dump_sense = dasd_diag_dump_sense,
+	.fill_info = dasd_diag_fill_info,
+};
+
+static int __init
+dasd_diag_init(void)
+{
+	if (!MACHINE_IS_VM) {
+		pr_info("Discipline %s cannot be used without z/VM\n",
+			dasd_diag_discipline.name);
+		return -ENODEV;
+	}
+	ASCEBC(dasd_diag_discipline.ebcname, 4);
+
+	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
+	register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
+	dasd_diag_discipline_pointer = &dasd_diag_discipline;
+	return 0;
+}
+
+static void __exit
+dasd_diag_cleanup(void)
+{
+	unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
+	irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
+	dasd_diag_discipline_pointer = NULL;
+}
+
+module_init(dasd_diag_init);
+module_exit(dasd_diag_cleanup);
diff --git a/drivers/s390/block/dasd_diag.h b/drivers/s390/block/dasd_diag.h
new file mode 100644
index 000000000..405b6feed
--- /dev/null
+++ b/drivers/s390/block/dasd_diag.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Based on.......: linux/drivers/s390/block/mdisk.h
+ * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2000
+ *
+ */
+
+#define MDSK_WRITE_REQ 0x01
+#define MDSK_READ_REQ  0x02
+
+#define INIT_BIO	0x00
+#define RW_BIO		0x01
+#define TERM_BIO	0x02
+
+#define DEV_CLASS_FBA	0x01
+#define DEV_CLASS_ECKD	0x04
+
+#define DASD_DIAG_CODE_31BIT		0x03
+#define DASD_DIAG_CODE_64BIT		0x07
+
+#define DASD_DIAG_RWFLAG_ASYNC		0x02
+#define DASD_DIAG_RWFLAG_NOCACHE	0x01
+
+#define DASD_DIAG_FLAGA_FORMAT_64BIT	0x80
+
+struct dasd_diag_characteristics {
+	u16 dev_nr;
+	u16 rdc_len;
+	u8 vdev_class;
+	u8 vdev_type;
+	u8 vdev_status;
+	u8 vdev_flags;
+	u8 rdev_class;
+	u8 rdev_type;
+	u8 rdev_model;
+	u8 rdev_features;
+} __attribute__ ((packed, aligned(4)));
+
+#define DASD_DIAG_FLAGA_DEFAULT		DASD_DIAG_FLAGA_FORMAT_64BIT
+
+typedef u64 blocknum_t;
+typedef s64 sblocknum_t;
+
+struct dasd_diag_bio {
+	u8 type;
+	u8 status;
+	u8 spare1[2];
+	u32 alet;
+	blocknum_t block_number;
+	void *buffer;
+} __attribute__ ((packed, aligned(8)));
+
+struct dasd_diag_init_io {
+	u16 dev_nr;
+	u8 flaga;
+	u8 spare1[21];
+	u32 block_size;
+	u8 spare2[4];
+	blocknum_t offset;
+	sblocknum_t start_block;
+	blocknum_t end_block;
+	u8  spare3[8];
+} __attribute__ ((packed, aligned(8)));
+
+struct dasd_diag_rw_io {
+	u16 dev_nr;
+	u8  flaga;
+	u8  spare1[21];
+	u8  key;
+	u8  flags;
+	u8  spare2[2];
+	u32 block_count;
+	u32 alet;
+	u8  spare3[4];
+	u64 interrupt_params;
+	struct dasd_diag_bio *bio_list;
+	u8  spare4[8];
+} __attribute__ ((packed, aligned(8)));
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
new file mode 100644
index 000000000..a2e34c853
--- /dev/null
+++ b/drivers/s390/block/dasd_eckd.c
@@ -0,0 +1,5840 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
+ * Author.........: Nigel Hislop <hislop_nigel@emc.com>
+ */
+
+#define KMSG_COMPONENT "dasd-eckd"
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/hdreg.h>	/* HDIO_GETGEO			    */
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/compat.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+
+#include <asm/css_chars.h>
+#include <asm/debug.h>
+#include <asm/idals.h>
+#include <asm/ebcdic.h>
+#include <asm/io.h>
+#include <linux/uaccess.h>
+#include <asm/cio.h>
+#include <asm/ccwdev.h>
+#include <asm/itcw.h>
+#include <asm/schid.h>
+#include <asm/chpid.h>
+
+#include "dasd_int.h"
+#include "dasd_eckd.h"
+
+#ifdef PRINTK_HEADER
+#undef PRINTK_HEADER
+#endif				/* PRINTK_HEADER */
+#define PRINTK_HEADER "dasd(eckd):"
+
+#define ECKD_C0(i) (i->home_bytes)
+#define ECKD_F(i) (i->formula)
+#define ECKD_F1(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f1):\
+		    (i->factors.f_0x02.f1))
+#define ECKD_F2(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f2):\
+		    (i->factors.f_0x02.f2))
+#define ECKD_F3(i) (ECKD_F(i)==0x01?(i->factors.f_0x01.f3):\
+		    (i->factors.f_0x02.f3))
+#define ECKD_F4(i) (ECKD_F(i)==0x02?(i->factors.f_0x02.f4):0)
+#define ECKD_F5(i) (ECKD_F(i)==0x02?(i->factors.f_0x02.f5):0)
+#define ECKD_F6(i) (i->factor6)
+#define ECKD_F7(i) (i->factor7)
+#define ECKD_F8(i) (i->factor8)
+
+/*
+ * raw track access always map to 64k in memory
+ * so it maps to 16 blocks of 4k per track
+ */
+#define DASD_RAW_BLOCK_PER_TRACK 16
+#define DASD_RAW_BLOCKSIZE 4096
+/* 64k are 128 x 512 byte sectors  */
+#define DASD_RAW_SECTORS_PER_TRACK 128
+
+MODULE_LICENSE("GPL");
+
+static struct dasd_discipline dasd_eckd_discipline;
+
+/* The ccw bus type uses this table to find devices that it sends to
+ * dasd_eckd_probe */
+static struct ccw_device_id dasd_eckd_ids[] = {
+	{ CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3390, 0), .driver_info = 0x1},
+	{ CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3390, 0), .driver_info = 0x2},
+	{ CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3380, 0), .driver_info = 0x3},
+	{ CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3380, 0), .driver_info = 0x4},
+	{ CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3380, 0), .driver_info = 0x5},
+	{ CCW_DEVICE_DEVTYPE (0x9343, 0, 0x9345, 0), .driver_info = 0x6},
+	{ CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3390, 0), .driver_info = 0x7},
+	{ CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3380, 0), .driver_info = 0x8},
+	{ CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3390, 0), .driver_info = 0x9},
+	{ CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3380, 0), .driver_info = 0xa},
+	{ /* end of list */ },
+};
+
+MODULE_DEVICE_TABLE(ccw, dasd_eckd_ids);
+
+static struct ccw_driver dasd_eckd_driver; /* see below */
+
+static void *rawpadpage;
+
+#define INIT_CQR_OK 0
+#define INIT_CQR_UNFORMATTED 1
+#define INIT_CQR_ERROR 2
+
+/* emergency request for reserve/release */
+static struct {
+	struct dasd_ccw_req cqr;
+	struct ccw1 ccw;
+	char data[32];
+} *dasd_reserve_req;
+static DEFINE_MUTEX(dasd_reserve_mutex);
+
+/* definitions for the path verification worker */
+struct path_verification_work_data {
+	struct work_struct worker;
+	struct dasd_device *device;
+	struct dasd_ccw_req cqr;
+	struct ccw1 ccw;
+	__u8 rcd_buffer[DASD_ECKD_RCD_DATA_SIZE];
+	int isglobal;
+	__u8 tbvpm;
+};
+static struct path_verification_work_data *path_verification_worker;
+static DEFINE_MUTEX(dasd_path_verification_mutex);
+
+struct check_attention_work_data {
+	struct work_struct worker;
+	struct dasd_device *device;
+	__u8 lpum;
+};
+
+static int prepare_itcw(struct itcw *, unsigned int, unsigned int, int,
+			struct dasd_device *, struct dasd_device *,
+			unsigned int, int, unsigned int, unsigned int,
+			unsigned int, unsigned int);
+
+/* initial attempt at a probe function. this can be simplified once
+ * the other detection code is gone */
+static int
+dasd_eckd_probe (struct ccw_device *cdev)
+{
+	int ret;
+
+	/* set ECKD specific ccw-device options */
+	ret = ccw_device_set_options(cdev, CCWDEV_ALLOW_FORCE |
+				     CCWDEV_DO_PATHGROUP | CCWDEV_DO_MULTIPATH);
+	if (ret) {
+		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
+				"dasd_eckd_probe: could not set "
+				"ccw-device options");
+		return ret;
+	}
+	ret = dasd_generic_probe(cdev, &dasd_eckd_discipline);
+	return ret;
+}
+
+static int
+dasd_eckd_set_online(struct ccw_device *cdev)
+{
+	return dasd_generic_set_online(cdev, &dasd_eckd_discipline);
+}
+
+static const int sizes_trk0[] = { 28, 148, 84 };
+#define LABEL_SIZE 140
+
+/* head and record addresses of count_area read in analysis ccw */
+static const int count_area_head[] = { 0, 0, 0, 0, 2 };
+static const int count_area_rec[] = { 1, 2, 3, 4, 1 };
+
+static inline unsigned int
+round_up_multiple(unsigned int no, unsigned int mult)
+{
+	int rem = no % mult;
+	return (rem ? no - rem + mult : no);
+}
+
+static inline unsigned int
+ceil_quot(unsigned int d1, unsigned int d2)
+{
+	return (d1 + (d2 - 1)) / d2;
+}
+
+static unsigned int
+recs_per_track(struct dasd_eckd_characteristics * rdc,
+	       unsigned int kl, unsigned int dl)
+{
+	int dn, kn;
+
+	switch (rdc->dev_type) {
+	case 0x3380:
+		if (kl)
+			return 1499 / (15 + 7 + ceil_quot(kl + 12, 32) +
+				       ceil_quot(dl + 12, 32));
+		else
+			return 1499 / (15 + ceil_quot(dl + 12, 32));
+	case 0x3390:
+		dn = ceil_quot(dl + 6, 232) + 1;
+		if (kl) {
+			kn = ceil_quot(kl + 6, 232) + 1;
+			return 1729 / (10 + 9 + ceil_quot(kl + 6 * kn, 34) +
+				       9 + ceil_quot(dl + 6 * dn, 34));
+		} else
+			return 1729 / (10 + 9 + ceil_quot(dl + 6 * dn, 34));
+	case 0x9345:
+		dn = ceil_quot(dl + 6, 232) + 1;
+		if (kl) {
+			kn = ceil_quot(kl + 6, 232) + 1;
+			return 1420 / (18 + 7 + ceil_quot(kl + 6 * kn, 34) +
+				       ceil_quot(dl + 6 * dn, 34));
+		} else
+			return 1420 / (18 + 7 + ceil_quot(dl + 6 * dn, 34));
+	}
+	return 0;
+}
+
+static void set_ch_t(struct ch_t *geo, __u32 cyl, __u8 head)
+{
+	geo->cyl = (__u16) cyl;
+	geo->head = cyl >> 16;
+	geo->head <<= 4;
+	geo->head |= head;
+}
+
+static int set_timestamp(struct ccw1 *ccw, struct DE_eckd_data *data,
+		     struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	int rc;
+
+	rc = get_phys_clock(&data->ep_sys_time);
+	/*
+	 * Ignore return code if XRC is not supported or
+	 * sync clock is switched off
+	 */
+	if ((rc && !private->rdc_data.facilities.XRC_supported) ||
+	    rc == -EOPNOTSUPP || rc == -EACCES)
+		return 0;
+
+	/* switch on System Time Stamp - needed for XRC Support */
+	data->ga_extended |= 0x08; /* switch on 'Time Stamp Valid'   */
+	data->ga_extended |= 0x02; /* switch on 'Extended Parameter' */
+
+	if (ccw) {
+		ccw->count = sizeof(struct DE_eckd_data);
+		ccw->flags |= CCW_FLAG_SLI;
+	}
+
+	return rc;
+}
+
+static int
+define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
+	      unsigned int totrk, int cmd, struct dasd_device *device,
+	      int blksize)
+{
+	struct dasd_eckd_private *private = device->private;
+	u16 heads, beghead, endhead;
+	u32 begcyl, endcyl;
+	int rc = 0;
+
+	if (ccw) {
+		ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
+		ccw->flags = 0;
+		ccw->count = 16;
+		ccw->cda = (__u32)__pa(data);
+	}
+
+	memset(data, 0, sizeof(struct DE_eckd_data));
+	switch (cmd) {
+	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
+	case DASD_ECKD_CCW_READ_RECORD_ZERO:
+	case DASD_ECKD_CCW_READ:
+	case DASD_ECKD_CCW_READ_MT:
+	case DASD_ECKD_CCW_READ_CKD:
+	case DASD_ECKD_CCW_READ_CKD_MT:
+	case DASD_ECKD_CCW_READ_KD:
+	case DASD_ECKD_CCW_READ_KD_MT:
+		data->mask.perm = 0x1;
+		data->attributes.operation = private->attrib.operation;
+		break;
+	case DASD_ECKD_CCW_READ_COUNT:
+		data->mask.perm = 0x1;
+		data->attributes.operation = DASD_BYPASS_CACHE;
+		break;
+	case DASD_ECKD_CCW_READ_TRACK:
+	case DASD_ECKD_CCW_READ_TRACK_DATA:
+		data->mask.perm = 0x1;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = 0;
+		break;
+	case DASD_ECKD_CCW_WRITE:
+	case DASD_ECKD_CCW_WRITE_MT:
+	case DASD_ECKD_CCW_WRITE_KD:
+	case DASD_ECKD_CCW_WRITE_KD_MT:
+		data->mask.perm = 0x02;
+		data->attributes.operation = private->attrib.operation;
+		rc = set_timestamp(ccw, data, device);
+		break;
+	case DASD_ECKD_CCW_WRITE_CKD:
+	case DASD_ECKD_CCW_WRITE_CKD_MT:
+		data->attributes.operation = DASD_BYPASS_CACHE;
+		rc = set_timestamp(ccw, data, device);
+		break;
+	case DASD_ECKD_CCW_ERASE:
+	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
+	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
+		data->mask.perm = 0x3;
+		data->mask.auth = 0x1;
+		data->attributes.operation = DASD_BYPASS_CACHE;
+		rc = set_timestamp(ccw, data, device);
+		break;
+	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
+		data->mask.perm = 0x03;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = 0;
+		break;
+	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
+		data->mask.perm = 0x02;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = blksize;
+		rc = set_timestamp(ccw, data, device);
+		break;
+	default:
+		dev_err(&device->cdev->dev,
+			"0x%x is not a known command\n", cmd);
+		break;
+	}
+
+	data->attributes.mode = 0x3;	/* ECKD */
+
+	if ((private->rdc_data.cu_type == 0x2105 ||
+	     private->rdc_data.cu_type == 0x2107 ||
+	     private->rdc_data.cu_type == 0x1750)
+	    && !(private->uses_cdl && trk < 2))
+		data->ga_extended |= 0x40; /* Regular Data Format Mode */
+
+	heads = private->rdc_data.trk_per_cyl;
+	begcyl = trk / heads;
+	beghead = trk % heads;
+	endcyl = totrk / heads;
+	endhead = totrk % heads;
+
+	/* check for sequential prestage - enhance cylinder range */
+	if (data->attributes.operation == DASD_SEQ_PRESTAGE ||
+	    data->attributes.operation == DASD_SEQ_ACCESS) {
+
+		if (endcyl + private->attrib.nr_cyl < private->real_cyl)
+			endcyl += private->attrib.nr_cyl;
+		else
+			endcyl = (private->real_cyl - 1);
+	}
+
+	set_ch_t(&data->beg_ext, begcyl, beghead);
+	set_ch_t(&data->end_ext, endcyl, endhead);
+	return rc;
+}
+
+
+static void locate_record_ext(struct ccw1 *ccw, struct LRE_eckd_data *data,
+			      unsigned int trk, unsigned int rec_on_trk,
+			      int count, int cmd, struct dasd_device *device,
+			      unsigned int reclen, unsigned int tlf)
+{
+	struct dasd_eckd_private *private = device->private;
+	int sector;
+	int dn, d;
+
+	if (ccw) {
+		ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD_EXT;
+		ccw->flags = 0;
+		if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
+			ccw->count = 22;
+		else
+			ccw->count = 20;
+		ccw->cda = (__u32)__pa(data);
+	}
+
+	memset(data, 0, sizeof(*data));
+	sector = 0;
+	if (rec_on_trk) {
+		switch (private->rdc_data.dev_type) {
+		case 0x3390:
+			dn = ceil_quot(reclen + 6, 232);
+			d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
+			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
+			break;
+		case 0x3380:
+			d = 7 + ceil_quot(reclen + 12, 32);
+			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
+			break;
+		}
+	}
+	data->sector = sector;
+	/* note: meaning of count depends on the operation
+	 *	 for record based I/O it's the number of records, but for
+	 *	 track based I/O it's the number of tracks
+	 */
+	data->count = count;
+	switch (cmd) {
+	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x03;
+		break;
+	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x16;
+		break;
+	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
+		data->operation.orientation = 0x1;
+		data->operation.operation = 0x03;
+		data->count++;
+		break;
+	case DASD_ECKD_CCW_READ_RECORD_ZERO:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x16;
+		data->count++;
+		break;
+	case DASD_ECKD_CCW_WRITE:
+	case DASD_ECKD_CCW_WRITE_MT:
+	case DASD_ECKD_CCW_WRITE_KD:
+	case DASD_ECKD_CCW_WRITE_KD_MT:
+		data->auxiliary.length_valid = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x01;
+		break;
+	case DASD_ECKD_CCW_WRITE_CKD:
+	case DASD_ECKD_CCW_WRITE_CKD_MT:
+		data->auxiliary.length_valid = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x03;
+		break;
+	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
+		data->operation.orientation = 0x0;
+		data->operation.operation = 0x3F;
+		data->extended_operation = 0x11;
+		data->length = 0;
+		data->extended_parameter_length = 0x02;
+		if (data->count > 8) {
+			data->extended_parameter[0] = 0xFF;
+			data->extended_parameter[1] = 0xFF;
+			data->extended_parameter[1] <<= (16 - count);
+		} else {
+			data->extended_parameter[0] = 0xFF;
+			data->extended_parameter[0] <<= (8 - count);
+			data->extended_parameter[1] = 0x00;
+		}
+		data->sector = 0xFF;
+		break;
+	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
+		data->auxiliary.length_valid = 0x1;
+		data->length = reclen;	/* not tlf, as one might think */
+		data->operation.operation = 0x3F;
+		data->extended_operation = 0x23;
+		break;
+	case DASD_ECKD_CCW_READ:
+	case DASD_ECKD_CCW_READ_MT:
+	case DASD_ECKD_CCW_READ_KD:
+	case DASD_ECKD_CCW_READ_KD_MT:
+		data->auxiliary.length_valid = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x06;
+		break;
+	case DASD_ECKD_CCW_READ_CKD:
+	case DASD_ECKD_CCW_READ_CKD_MT:
+		data->auxiliary.length_valid = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x16;
+		break;
+	case DASD_ECKD_CCW_READ_COUNT:
+		data->operation.operation = 0x06;
+		break;
+	case DASD_ECKD_CCW_READ_TRACK:
+		data->operation.orientation = 0x1;
+		data->operation.operation = 0x0C;
+		data->extended_parameter_length = 0;
+		data->sector = 0xFF;
+		break;
+	case DASD_ECKD_CCW_READ_TRACK_DATA:
+		data->auxiliary.length_valid = 0x1;
+		data->length = tlf;
+		data->operation.operation = 0x0C;
+		break;
+	case DASD_ECKD_CCW_ERASE:
+		data->length = reclen;
+		data->auxiliary.length_valid = 0x1;
+		data->operation.operation = 0x0b;
+		break;
+	default:
+		DBF_DEV_EVENT(DBF_ERR, device,
+			    "fill LRE unknown opcode 0x%x", cmd);
+		BUG();
+	}
+	set_ch_t(&data->seek_addr,
+		 trk / private->rdc_data.trk_per_cyl,
+		 trk % private->rdc_data.trk_per_cyl);
+	data->search_arg.cyl = data->seek_addr.cyl;
+	data->search_arg.head = data->seek_addr.head;
+	data->search_arg.record = rec_on_trk;
+}
+
+static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
+		      unsigned int trk, unsigned int totrk, int cmd,
+		      struct dasd_device *basedev, struct dasd_device *startdev,
+		      unsigned int format, unsigned int rec_on_trk, int count,
+		      unsigned int blksize, unsigned int tlf)
+{
+	struct dasd_eckd_private *basepriv, *startpriv;
+	struct LRE_eckd_data *lredata;
+	struct DE_eckd_data *dedata;
+	int rc = 0;
+
+	basepriv = basedev->private;
+	startpriv = startdev->private;
+	dedata = &pfxdata->define_extent;
+	lredata = &pfxdata->locate_record;
+
+	ccw->cmd_code = DASD_ECKD_CCW_PFX;
+	ccw->flags = 0;
+	if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK) {
+		ccw->count = sizeof(*pfxdata) + 2;
+		ccw->cda = (__u32) __pa(pfxdata);
+		memset(pfxdata, 0, sizeof(*pfxdata) + 2);
+	} else {
+		ccw->count = sizeof(*pfxdata);
+		ccw->cda = (__u32) __pa(pfxdata);
+		memset(pfxdata, 0, sizeof(*pfxdata));
+	}
+
+	/* prefix data */
+	if (format > 1) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "PFX LRE unknown format 0x%x", format);
+		BUG();
+		return -EINVAL;
+	}
+	pfxdata->format = format;
+	pfxdata->base_address = basepriv->ned->unit_addr;
+	pfxdata->base_lss = basepriv->ned->ID;
+	pfxdata->validity.define_extent = 1;
+
+	/* private uid is kept up to date, conf_data may be outdated */
+	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
+		pfxdata->validity.verify_base = 1;
+
+	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
+		pfxdata->validity.verify_base = 1;
+		pfxdata->validity.hyper_pav = 1;
+	}
+
+	rc = define_extent(NULL, dedata, trk, totrk, cmd, basedev, blksize);
+
+	/*
+	 * For some commands the System Time Stamp is set in the define extent
+	 * data when XRC is supported. The validity of the time stamp must be
+	 * reflected in the prefix data as well.
+	 */
+	if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
+		pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid'   */
+
+	if (format == 1) {
+		locate_record_ext(NULL, lredata, trk, rec_on_trk, count, cmd,
+				  basedev, blksize, tlf);
+	}
+
+	return rc;
+}
+
+static int prefix(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
+		  unsigned int trk, unsigned int totrk, int cmd,
+		  struct dasd_device *basedev, struct dasd_device *startdev)
+{
+	return prefix_LRE(ccw, pfxdata, trk, totrk, cmd, basedev, startdev,
+			  0, 0, 0, 0, 0);
+}
+
+static void
+locate_record(struct ccw1 *ccw, struct LO_eckd_data *data, unsigned int trk,
+	      unsigned int rec_on_trk, int no_rec, int cmd,
+	      struct dasd_device * device, int reclen)
+{
+	struct dasd_eckd_private *private = device->private;
+	int sector;
+	int dn, d;
+
+	DBF_DEV_EVENT(DBF_INFO, device,
+		  "Locate: trk %d, rec %d, no_rec %d, cmd %d, reclen %d",
+		  trk, rec_on_trk, no_rec, cmd, reclen);
+
+	ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
+	ccw->flags = 0;
+	ccw->count = 16;
+	ccw->cda = (__u32) __pa(data);
+
+	memset(data, 0, sizeof(struct LO_eckd_data));
+	sector = 0;
+	if (rec_on_trk) {
+		switch (private->rdc_data.dev_type) {
+		case 0x3390:
+			dn = ceil_quot(reclen + 6, 232);
+			d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
+			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
+			break;
+		case 0x3380:
+			d = 7 + ceil_quot(reclen + 12, 32);
+			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
+			break;
+		}
+	}
+	data->sector = sector;
+	data->count = no_rec;
+	switch (cmd) {
+	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x03;
+		break;
+	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x16;
+		break;
+	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
+		data->operation.orientation = 0x1;
+		data->operation.operation = 0x03;
+		data->count++;
+		break;
+	case DASD_ECKD_CCW_READ_RECORD_ZERO:
+		data->operation.orientation = 0x3;
+		data->operation.operation = 0x16;
+		data->count++;
+		break;
+	case DASD_ECKD_CCW_WRITE:
+	case DASD_ECKD_CCW_WRITE_MT:
+	case DASD_ECKD_CCW_WRITE_KD:
+	case DASD_ECKD_CCW_WRITE_KD_MT:
+		data->auxiliary.last_bytes_used = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x01;
+		break;
+	case DASD_ECKD_CCW_WRITE_CKD:
+	case DASD_ECKD_CCW_WRITE_CKD_MT:
+		data->auxiliary.last_bytes_used = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x03;
+		break;
+	case DASD_ECKD_CCW_READ:
+	case DASD_ECKD_CCW_READ_MT:
+	case DASD_ECKD_CCW_READ_KD:
+	case DASD_ECKD_CCW_READ_KD_MT:
+		data->auxiliary.last_bytes_used = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x06;
+		break;
+	case DASD_ECKD_CCW_READ_CKD:
+	case DASD_ECKD_CCW_READ_CKD_MT:
+		data->auxiliary.last_bytes_used = 0x1;
+		data->length = reclen;
+		data->operation.operation = 0x16;
+		break;
+	case DASD_ECKD_CCW_READ_COUNT:
+		data->operation.operation = 0x06;
+		break;
+	case DASD_ECKD_CCW_ERASE:
+		data->length = reclen;
+		data->auxiliary.last_bytes_used = 0x1;
+		data->operation.operation = 0x0b;
+		break;
+	default:
+		DBF_DEV_EVENT(DBF_ERR, device, "unknown locate record "
+			      "opcode 0x%x", cmd);
+	}
+	set_ch_t(&data->seek_addr,
+		 trk / private->rdc_data.trk_per_cyl,
+		 trk % private->rdc_data.trk_per_cyl);
+	data->search_arg.cyl = data->seek_addr.cyl;
+	data->search_arg.head = data->seek_addr.head;
+	data->search_arg.record = rec_on_trk;
+}
+
+/*
+ * Returns 1 if the block is one of the special blocks that needs
+ * to get read/written with the KD variant of the command.
+ * That is DASD_ECKD_READ_KD_MT instead of DASD_ECKD_READ_MT and
+ * DASD_ECKD_WRITE_KD_MT instead of DASD_ECKD_WRITE_MT.
+ * Luckily the KD variants differ only by one bit (0x08) from the
+ * normal variant. So don't wonder about code like:
+ * if (dasd_eckd_cdl_special(blk_per_trk, recid))
+ *         ccw->cmd_code |= 0x8;
+ */
+static inline int
+dasd_eckd_cdl_special(int blk_per_trk, int recid)
+{
+	if (recid < 3)
+		return 1;
+	if (recid < blk_per_trk)
+		return 0;
+	if (recid < 2 * blk_per_trk)
+		return 1;
+	return 0;
+}
+
+/*
+ * Returns the record size for the special blocks of the cdl format.
+ * Only returns something useful if dasd_eckd_cdl_special is true
+ * for the recid.
+ */
+static inline int
+dasd_eckd_cdl_reclen(int recid)
+{
+	if (recid < 3)
+		return sizes_trk0[recid];
+	return LABEL_SIZE;
+}
+/* create unique id from private structure. */
+static void create_uid(struct dasd_eckd_private *private)
+{
+	int count;
+	struct dasd_uid *uid;
+
+	uid = &private->uid;
+	memset(uid, 0, sizeof(struct dasd_uid));
+	memcpy(uid->vendor, private->ned->HDA_manufacturer,
+	       sizeof(uid->vendor) - 1);
+	EBCASC(uid->vendor, sizeof(uid->vendor) - 1);
+	memcpy(uid->serial, private->ned->HDA_location,
+	       sizeof(uid->serial) - 1);
+	EBCASC(uid->serial, sizeof(uid->serial) - 1);
+	uid->ssid = private->gneq->subsystemID;
+	uid->real_unit_addr = private->ned->unit_addr;
+	if (private->sneq) {
+		uid->type = private->sneq->sua_flags;
+		if (uid->type == UA_BASE_PAV_ALIAS)
+			uid->base_unit_addr = private->sneq->base_unit_addr;
+	} else {
+		uid->type = UA_BASE_DEVICE;
+	}
+	if (private->vdsneq) {
+		for (count = 0; count < 16; count++) {
+			sprintf(uid->vduit+2*count, "%02x",
+				private->vdsneq->uit[count]);
+		}
+	}
+}
+
+/*
+ * Generate device unique id that specifies the physical device.
+ */
+static int dasd_eckd_generate_uid(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+
+	if (!private)
+		return -ENODEV;
+	if (!private->ned || !private->gneq)
+		return -ENODEV;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	create_uid(private);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	return 0;
+}
+
+static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+
+	if (private) {
+		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+		*uid = private->uid;
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+/*
+ * compare device UID with data of a given dasd_eckd_private structure
+ * return 0 for match
+ */
+static int dasd_eckd_compare_path_uid(struct dasd_device *device,
+				      struct dasd_eckd_private *private)
+{
+	struct dasd_uid device_uid;
+
+	create_uid(private);
+	dasd_eckd_get_uid(device, &device_uid);
+
+	return memcmp(&device_uid, &private->uid, sizeof(struct dasd_uid));
+}
+
+static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
+				   struct dasd_ccw_req *cqr,
+				   __u8 *rcd_buffer,
+				   __u8 lpm)
+{
+	struct ccw1 *ccw;
+	/*
+	 * buffer has to start with EBCDIC "V1.0" to show
+	 * support for virtual device SNEQ
+	 */
+	rcd_buffer[0] = 0xE5;
+	rcd_buffer[1] = 0xF1;
+	rcd_buffer[2] = 0x4B;
+	rcd_buffer[3] = 0xF0;
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_RCD;
+	ccw->flags = 0;
+	ccw->cda = (__u32)(addr_t)rcd_buffer;
+	ccw->count = DASD_ECKD_RCD_DATA_SIZE;
+	cqr->magic = DASD_ECKD_MAGIC;
+
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->expires = 10*HZ;
+	cqr->lpm = lpm;
+	cqr->retries = 256;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
+}
+
+/*
+ * Wakeup helper for read_conf
+ * if the cqr is not done and needs some error recovery
+ * the buffer has to be re-initialized with the EBCDIC "V1.0"
+ * to show support for virtual device SNEQ
+ */
+static void read_conf_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	struct ccw1 *ccw;
+	__u8 *rcd_buffer;
+
+	if (cqr->status !=  DASD_CQR_DONE) {
+		ccw = cqr->cpaddr;
+		rcd_buffer = (__u8 *)((addr_t) ccw->cda);
+		memset(rcd_buffer, 0, sizeof(*rcd_buffer));
+
+		rcd_buffer[0] = 0xE5;
+		rcd_buffer[1] = 0xF1;
+		rcd_buffer[2] = 0x4B;
+		rcd_buffer[3] = 0xF0;
+	}
+	dasd_wakeup_cb(cqr, data);
+}
+
+static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
+					   struct dasd_ccw_req *cqr,
+					   __u8 *rcd_buffer,
+					   __u8 lpm)
+{
+	struct ciw *ciw;
+	int rc;
+	/*
+	 * sanity check: scan for RCD command in extended SenseID data
+	 * some devices do not support RCD
+	 */
+	ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
+	if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD)
+		return -EOPNOTSUPP;
+
+	dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buffer, lpm);
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
+	cqr->retries = 5;
+	cqr->callback = read_conf_cb;
+	rc = dasd_sleep_on_immediatly(cqr);
+	return rc;
+}
+
+static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
+				   void **rcd_buffer,
+				   int *rcd_buffer_size, __u8 lpm)
+{
+	struct ciw *ciw;
+	char *rcd_buf = NULL;
+	int ret;
+	struct dasd_ccw_req *cqr;
+
+	/*
+	 * sanity check: scan for RCD command in extended SenseID data
+	 * some devices do not support RCD
+	 */
+	ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
+	if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD) {
+		ret = -EOPNOTSUPP;
+		goto out_error;
+	}
+	rcd_buf = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL | GFP_DMA);
+	if (!rcd_buf) {
+		ret = -ENOMEM;
+		goto out_error;
+	}
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */,
+				   0, /* use rcd_buf as data ara */
+				   device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "Could not allocate RCD request");
+		ret = -ENOMEM;
+		goto out_error;
+	}
+	dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
+	cqr->callback = read_conf_cb;
+	ret = dasd_sleep_on(cqr);
+	/*
+	 * on success we update the user input parms
+	 */
+	dasd_sfree_request(cqr, cqr->memdev);
+	if (ret)
+		goto out_error;
+
+	*rcd_buffer_size = DASD_ECKD_RCD_DATA_SIZE;
+	*rcd_buffer = rcd_buf;
+	return 0;
+out_error:
+	kfree(rcd_buf);
+	*rcd_buffer = NULL;
+	*rcd_buffer_size = 0;
+	return ret;
+}
+
+static int dasd_eckd_identify_conf_parts(struct dasd_eckd_private *private)
+{
+
+	struct dasd_sneq *sneq;
+	int i, count;
+
+	private->ned = NULL;
+	private->sneq = NULL;
+	private->vdsneq = NULL;
+	private->gneq = NULL;
+	count = private->conf_len / sizeof(struct dasd_sneq);
+	sneq = (struct dasd_sneq *)private->conf_data;
+	for (i = 0; i < count; ++i) {
+		if (sneq->flags.identifier == 1 && sneq->format == 1)
+			private->sneq = sneq;
+		else if (sneq->flags.identifier == 1 && sneq->format == 4)
+			private->vdsneq = (struct vd_sneq *)sneq;
+		else if (sneq->flags.identifier == 2)
+			private->gneq = (struct dasd_gneq *)sneq;
+		else if (sneq->flags.identifier == 3 && sneq->res1 == 1)
+			private->ned = (struct dasd_ned *)sneq;
+		sneq++;
+	}
+	if (!private->ned || !private->gneq) {
+		private->ned = NULL;
+		private->sneq = NULL;
+		private->vdsneq = NULL;
+		private->gneq = NULL;
+		return -EINVAL;
+	}
+	return 0;
+
+};
+
+static unsigned char dasd_eckd_path_access(void *conf_data, int conf_len)
+{
+	struct dasd_gneq *gneq;
+	int i, count, found;
+
+	count = conf_len / sizeof(*gneq);
+	gneq = (struct dasd_gneq *)conf_data;
+	found = 0;
+	for (i = 0; i < count; ++i) {
+		if (gneq->flags.identifier == 2) {
+			found = 1;
+			break;
+		}
+		gneq++;
+	}
+	if (found)
+		return ((char *)gneq)[18] & 0x07;
+	else
+		return 0;
+}
+
+static void dasd_eckd_clear_conf_data(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	int i;
+
+	private->conf_data = NULL;
+	private->conf_len = 0;
+	for (i = 0; i < 8; i++) {
+		kfree(device->path[i].conf_data);
+		device->path[i].conf_data = NULL;
+		device->path[i].cssid = 0;
+		device->path[i].ssid = 0;
+		device->path[i].chpid = 0;
+	}
+}
+
+
+static int dasd_eckd_read_conf(struct dasd_device *device)
+{
+	void *conf_data;
+	int conf_len, conf_data_saved;
+	int rc, path_err, pos;
+	__u8 lpm, opm;
+	struct dasd_eckd_private *private, path_private;
+	struct dasd_uid *uid;
+	char print_path_uid[60], print_device_uid[60];
+	struct channel_path_desc_fmt0 *chp_desc;
+	struct subchannel_id sch_id;
+
+	private = device->private;
+	opm = ccw_device_get_path_mask(device->cdev);
+	ccw_device_get_schid(device->cdev, &sch_id);
+	conf_data_saved = 0;
+	path_err = 0;
+	/* get configuration data per operational path */
+	for (lpm = 0x80; lpm; lpm>>= 1) {
+		if (!(lpm & opm))
+			continue;
+		rc = dasd_eckd_read_conf_lpm(device, &conf_data,
+					     &conf_len, lpm);
+		if (rc && rc != -EOPNOTSUPP) {	/* -EOPNOTSUPP is ok */
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+					"Read configuration data returned "
+					"error %d", rc);
+			return rc;
+		}
+		if (conf_data == NULL) {
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+					"No configuration data "
+					"retrieved");
+			/* no further analysis possible */
+			dasd_path_add_opm(device, opm);
+			continue;	/* no error */
+		}
+		/* save first valid configuration data */
+		if (!conf_data_saved) {
+			/* initially clear previously stored conf_data */
+			dasd_eckd_clear_conf_data(device);
+			private->conf_data = conf_data;
+			private->conf_len = conf_len;
+			if (dasd_eckd_identify_conf_parts(private)) {
+				private->conf_data = NULL;
+				private->conf_len = 0;
+				kfree(conf_data);
+				continue;
+			}
+			pos = pathmask_to_pos(lpm);
+			/* store per path conf_data */
+			device->path[pos].conf_data = conf_data;
+			device->path[pos].cssid = sch_id.cssid;
+			device->path[pos].ssid = sch_id.ssid;
+			chp_desc = ccw_device_get_chp_desc(device->cdev, pos);
+			if (chp_desc)
+				device->path[pos].chpid = chp_desc->chpid;
+			kfree(chp_desc);
+			/*
+			 * build device UID that other path data
+			 * can be compared to it
+			 */
+			dasd_eckd_generate_uid(device);
+			conf_data_saved++;
+		} else {
+			path_private.conf_data = conf_data;
+			path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
+			if (dasd_eckd_identify_conf_parts(
+				    &path_private)) {
+				path_private.conf_data = NULL;
+				path_private.conf_len = 0;
+				kfree(conf_data);
+				continue;
+			}
+			if (dasd_eckd_compare_path_uid(
+				    device, &path_private)) {
+				uid = &path_private.uid;
+				if (strlen(uid->vduit) > 0)
+					snprintf(print_path_uid,
+						 sizeof(print_path_uid),
+						 "%s.%s.%04x.%02x.%s",
+						 uid->vendor, uid->serial,
+						 uid->ssid, uid->real_unit_addr,
+						 uid->vduit);
+				else
+					snprintf(print_path_uid,
+						 sizeof(print_path_uid),
+						 "%s.%s.%04x.%02x",
+						 uid->vendor, uid->serial,
+						 uid->ssid,
+						 uid->real_unit_addr);
+				uid = &private->uid;
+				if (strlen(uid->vduit) > 0)
+					snprintf(print_device_uid,
+						 sizeof(print_device_uid),
+						 "%s.%s.%04x.%02x.%s",
+						 uid->vendor, uid->serial,
+						 uid->ssid, uid->real_unit_addr,
+						 uid->vduit);
+				else
+					snprintf(print_device_uid,
+						 sizeof(print_device_uid),
+						 "%s.%s.%04x.%02x",
+						 uid->vendor, uid->serial,
+						 uid->ssid,
+						 uid->real_unit_addr);
+				dev_err(&device->cdev->dev,
+					"Not all channel paths lead to "
+					"the same device, path %02X leads to "
+					"device %s instead of %s\n", lpm,
+					print_path_uid, print_device_uid);
+				path_err = -EINVAL;
+				dasd_path_add_cablepm(device, lpm);
+				continue;
+			}
+			pos = pathmask_to_pos(lpm);
+			/* store per path conf_data */
+			device->path[pos].conf_data = conf_data;
+			device->path[pos].cssid = sch_id.cssid;
+			device->path[pos].ssid = sch_id.ssid;
+			chp_desc = ccw_device_get_chp_desc(device->cdev, pos);
+			if (chp_desc)
+				device->path[pos].chpid = chp_desc->chpid;
+			kfree(chp_desc);
+			path_private.conf_data = NULL;
+			path_private.conf_len = 0;
+		}
+		switch (dasd_eckd_path_access(conf_data, conf_len)) {
+		case 0x02:
+			dasd_path_add_nppm(device, lpm);
+			break;
+		case 0x03:
+			dasd_path_add_ppm(device, lpm);
+			break;
+		}
+		if (!dasd_path_get_opm(device)) {
+			dasd_path_set_opm(device, lpm);
+			dasd_generic_path_operational(device);
+		} else {
+			dasd_path_add_opm(device, lpm);
+		}
+	}
+
+	return path_err;
+}
+
+static u32 get_fcx_max_data(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	int fcx_in_css, fcx_in_gneq, fcx_in_features;
+	unsigned int mdc;
+	int tpm;
+
+	if (dasd_nofcx)
+		return 0;
+	/* is transport mode supported? */
+	fcx_in_css = css_general_characteristics.fcx;
+	fcx_in_gneq = private->gneq->reserved2[7] & 0x04;
+	fcx_in_features = private->features.feature[40] & 0x80;
+	tpm = fcx_in_css && fcx_in_gneq && fcx_in_features;
+
+	if (!tpm)
+		return 0;
+
+	mdc = ccw_device_get_mdc(device->cdev, 0);
+	if (mdc == 0) {
+		dev_warn(&device->cdev->dev, "Detecting the maximum supported data size for zHPF requests failed\n");
+		return 0;
+	} else {
+		return (u32)mdc * FCX_MAX_DATA_FACTOR;
+	}
+}
+
+static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned int mdc;
+	u32 fcx_max_data;
+
+	if (private->fcx_max_data) {
+		mdc = ccw_device_get_mdc(device->cdev, lpm);
+		if (mdc == 0) {
+			dev_warn(&device->cdev->dev,
+				 "Detecting the maximum data size for zHPF "
+				 "requests failed (rc=%d) for a new path %x\n",
+				 mdc, lpm);
+			return mdc;
+		}
+		fcx_max_data = (u32)mdc * FCX_MAX_DATA_FACTOR;
+		if (fcx_max_data < private->fcx_max_data) {
+			dev_warn(&device->cdev->dev,
+				 "The maximum data size for zHPF requests %u "
+				 "on a new path %x is below the active maximum "
+				 "%u\n", fcx_max_data, lpm,
+				 private->fcx_max_data);
+			return -EACCES;
+		}
+	}
+	return 0;
+}
+
+static int rebuild_device_uid(struct dasd_device *device,
+			      struct path_verification_work_data *data)
+{
+	struct dasd_eckd_private *private = device->private;
+	__u8 lpm, opm = dasd_path_get_opm(device);
+	int rc = -ENODEV;
+
+	for (lpm = 0x80; lpm; lpm >>= 1) {
+		if (!(lpm & opm))
+			continue;
+		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
+		memset(&data->cqr, 0, sizeof(data->cqr));
+		data->cqr.cpaddr = &data->ccw;
+		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
+						     data->rcd_buffer,
+						     lpm);
+
+		if (rc) {
+			if (rc == -EOPNOTSUPP) /* -EOPNOTSUPP is ok */
+				continue;
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+					"Read configuration data "
+					"returned error %d", rc);
+			break;
+		}
+		memcpy(private->conf_data, data->rcd_buffer,
+		       DASD_ECKD_RCD_DATA_SIZE);
+		if (dasd_eckd_identify_conf_parts(private)) {
+			rc = -ENODEV;
+		} else /* first valid path is enough */
+			break;
+	}
+
+	if (!rc)
+		rc = dasd_eckd_generate_uid(device);
+
+	return rc;
+}
+
+static void do_path_verification_work(struct work_struct *work)
+{
+	struct path_verification_work_data *data;
+	struct dasd_device *device;
+	struct dasd_eckd_private path_private;
+	struct dasd_uid *uid;
+	__u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];
+	__u8 lpm, opm, npm, ppm, epm, hpfpm, cablepm;
+	unsigned long flags;
+	char print_uid[60];
+	int rc;
+
+	data = container_of(work, struct path_verification_work_data, worker);
+	device = data->device;
+
+	/* delay path verification until device was resumed */
+	if (test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
+		schedule_work(work);
+		return;
+	}
+	/* check if path verification already running and delay if so */
+	if (test_and_set_bit(DASD_FLAG_PATH_VERIFY, &device->flags)) {
+		schedule_work(work);
+		return;
+	}
+	opm = 0;
+	npm = 0;
+	ppm = 0;
+	epm = 0;
+	hpfpm = 0;
+	cablepm = 0;
+
+	for (lpm = 0x80; lpm; lpm >>= 1) {
+		if (!(lpm & data->tbvpm))
+			continue;
+		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
+		memset(&data->cqr, 0, sizeof(data->cqr));
+		data->cqr.cpaddr = &data->ccw;
+		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
+						     data->rcd_buffer,
+						     lpm);
+		if (!rc) {
+			switch (dasd_eckd_path_access(data->rcd_buffer,
+						      DASD_ECKD_RCD_DATA_SIZE)
+				) {
+			case 0x02:
+				npm |= lpm;
+				break;
+			case 0x03:
+				ppm |= lpm;
+				break;
+			}
+			opm |= lpm;
+		} else if (rc == -EOPNOTSUPP) {
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+					"path verification: No configuration "
+					"data retrieved");
+			opm |= lpm;
+		} else if (rc == -EAGAIN) {
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+					"path verification: device is stopped,"
+					" try again later");
+			epm |= lpm;
+		} else {
+			dev_warn(&device->cdev->dev,
+				 "Reading device feature codes failed "
+				 "(rc=%d) for new path %x\n", rc, lpm);
+			continue;
+		}
+		if (verify_fcx_max_data(device, lpm)) {
+			opm &= ~lpm;
+			npm &= ~lpm;
+			ppm &= ~lpm;
+			hpfpm |= lpm;
+			continue;
+		}
+
+		/*
+		 * save conf_data for comparison after
+		 * rebuild_device_uid may have changed
+		 * the original data
+		 */
+		memcpy(&path_rcd_buf, data->rcd_buffer,
+		       DASD_ECKD_RCD_DATA_SIZE);
+		path_private.conf_data = (void *) &path_rcd_buf;
+		path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
+		if (dasd_eckd_identify_conf_parts(&path_private)) {
+			path_private.conf_data = NULL;
+			path_private.conf_len = 0;
+			continue;
+		}
+
+		/*
+		 * compare path UID with device UID only if at least
+		 * one valid path is left
+		 * in other case the device UID may have changed and
+		 * the first working path UID will be used as device UID
+		 */
+		if (dasd_path_get_opm(device) &&
+		    dasd_eckd_compare_path_uid(device, &path_private)) {
+			/*
+			 * the comparison was not successful
+			 * rebuild the device UID with at least one
+			 * known path in case a z/VM hyperswap command
+			 * has changed the device
+			 *
+			 * after this compare again
+			 *
+			 * if either the rebuild or the recompare fails
+			 * the path can not be used
+			 */
+			if (rebuild_device_uid(device, data) ||
+			    dasd_eckd_compare_path_uid(
+				    device, &path_private)) {
+				uid = &path_private.uid;
+				if (strlen(uid->vduit) > 0)
+					snprintf(print_uid, sizeof(print_uid),
+						 "%s.%s.%04x.%02x.%s",
+						 uid->vendor, uid->serial,
+						 uid->ssid, uid->real_unit_addr,
+						 uid->vduit);
+				else
+					snprintf(print_uid, sizeof(print_uid),
+						 "%s.%s.%04x.%02x",
+						 uid->vendor, uid->serial,
+						 uid->ssid,
+						 uid->real_unit_addr);
+				dev_err(&device->cdev->dev,
+					"The newly added channel path %02X "
+					"will not be used because it leads "
+					"to a different device %s\n",
+					lpm, print_uid);
+				opm &= ~lpm;
+				npm &= ~lpm;
+				ppm &= ~lpm;
+				cablepm |= lpm;
+				continue;
+			}
+		}
+
+		/*
+		 * There is a small chance that a path is lost again between
+		 * above path verification and the following modification of
+		 * the device opm mask. We could avoid that race here by using
+		 * yet another path mask, but we rather deal with this unlikely
+		 * situation in dasd_start_IO.
+		 */
+		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+		if (!dasd_path_get_opm(device) && opm) {
+			dasd_path_set_opm(device, opm);
+			dasd_generic_path_operational(device);
+		} else {
+			dasd_path_add_opm(device, opm);
+		}
+		dasd_path_add_nppm(device, npm);
+		dasd_path_add_ppm(device, ppm);
+		dasd_path_add_tbvpm(device, epm);
+		dasd_path_add_cablepm(device, cablepm);
+		dasd_path_add_nohpfpm(device, hpfpm);
+		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	}
+	clear_bit(DASD_FLAG_PATH_VERIFY, &device->flags);
+	dasd_put_device(device);
+	if (data->isglobal)
+		mutex_unlock(&dasd_path_verification_mutex);
+	else
+		kfree(data);
+}
+
+static int dasd_eckd_verify_path(struct dasd_device *device, __u8 lpm)
+{
+	struct path_verification_work_data *data;
+
+	data = kmalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
+	if (!data) {
+		if (mutex_trylock(&dasd_path_verification_mutex)) {
+			data = path_verification_worker;
+			data->isglobal = 1;
+		} else
+			return -ENOMEM;
+	} else {
+		memset(data, 0, sizeof(*data));
+		data->isglobal = 0;
+	}
+	INIT_WORK(&data->worker, do_path_verification_work);
+	dasd_get_device(device);
+	data->device = device;
+	data->tbvpm = lpm;
+	schedule_work(&data->worker);
+	return 0;
+}
+
+static void dasd_eckd_reset_path(struct dasd_device *device, __u8 pm)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+
+	if (!private->fcx_max_data)
+		private->fcx_max_data = get_fcx_max_data(device);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	dasd_path_set_tbvpm(device, pm ? : dasd_path_get_notoperpm(device));
+	dasd_schedule_device_bh(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+
+static int dasd_eckd_read_features(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_rssd_features *features;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+
+	memset(&private->features, 0, sizeof(struct dasd_rssd_features));
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
+				   (sizeof(struct dasd_psf_prssd_data) +
+				    sizeof(struct dasd_rssd_features)),
+				   device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s", "Could not "
+				"allocate initialization request");
+		return PTR_ERR(cqr);
+	}
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->retries = 256;
+	cqr->expires = 10 * HZ;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = 0x41;	/* Read Feature Codes */
+	/* all other bytes of prssdp must be zero */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->cda = (__u32)(addr_t) prssdp;
+
+	/* Read Subsystem Data - feature codes */
+	features = (struct dasd_rssd_features *) (prssdp + 1);
+	memset(features, 0, sizeof(struct dasd_rssd_features));
+
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(struct dasd_rssd_features);
+	ccw->cda = (__u32)(addr_t) features;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	rc = dasd_sleep_on(cqr);
+	if (rc == 0) {
+		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+		features = (struct dasd_rssd_features *) (prssdp + 1);
+		memcpy(&private->features, features,
+		       sizeof(struct dasd_rssd_features));
+	} else
+		dev_warn(&device->cdev->dev, "Reading device feature codes"
+			 " failed with rc=%d\n", rc);
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+
+/*
+ * Build CP for Perform Subsystem Function - SSC.
+ */
+static struct dasd_ccw_req *dasd_eckd_build_psf_ssc(struct dasd_device *device,
+						    int enable_pav)
+{
+	struct dasd_ccw_req *cqr;
+	struct dasd_psf_ssc_data *psf_ssc_data;
+	struct ccw1 *ccw;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
+				  sizeof(struct dasd_psf_ssc_data),
+				   device, NULL);
+
+	if (IS_ERR(cqr)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			   "Could not allocate PSF-SSC request");
+		return cqr;
+	}
+	psf_ssc_data = (struct dasd_psf_ssc_data *)cqr->data;
+	psf_ssc_data->order = PSF_ORDER_SSC;
+	psf_ssc_data->suborder = 0xc0;
+	if (enable_pav) {
+		psf_ssc_data->suborder |= 0x08;
+		psf_ssc_data->reserved[0] = 0x88;
+	}
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->cda = (__u32)(addr_t)psf_ssc_data;
+	ccw->count = 66;
+
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->retries = 256;
+	cqr->expires = 10*HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+/*
+ * Perform Subsystem Function.
+ * It is necessary to trigger CIO for channel revalidation since this
+ * call might change behaviour of DASD devices.
+ */
+static int
+dasd_eckd_psf_ssc(struct dasd_device *device, int enable_pav,
+		  unsigned long flags)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+
+	cqr = dasd_eckd_build_psf_ssc(device, enable_pav);
+	if (IS_ERR(cqr))
+		return PTR_ERR(cqr);
+
+	/*
+	 * set flags e.g. turn on failfast, to prevent blocking
+	 * the calling function should handle failed requests
+	 */
+	cqr->flags |= flags;
+
+	rc = dasd_sleep_on(cqr);
+	if (!rc)
+		/* trigger CIO to reprobe devices */
+		css_schedule_reprobe();
+	else if (cqr->intrc == -EAGAIN)
+		rc = -EAGAIN;
+
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * Valide storage server of current device.
+ */
+static int dasd_eckd_validate_server(struct dasd_device *device,
+				     unsigned long flags)
+{
+	struct dasd_eckd_private *private = device->private;
+	int enable_pav, rc;
+
+	if (private->uid.type == UA_BASE_PAV_ALIAS ||
+	    private->uid.type == UA_HYPER_PAV_ALIAS)
+		return 0;
+	if (dasd_nopav || MACHINE_IS_VM)
+		enable_pav = 0;
+	else
+		enable_pav = 1;
+	rc = dasd_eckd_psf_ssc(device, enable_pav, flags);
+
+	/* may be requested feature is not available on server,
+	 * therefore just report error and go ahead */
+	DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "PSF-SSC for SSID %04x "
+			"returned rc=%d", private->uid.ssid, rc);
+	return rc;
+}
+
+/*
+ * worker to do a validate server in case of a lost pathgroup
+ */
+static void dasd_eckd_do_validate_server(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  kick_validate);
+	unsigned long flags = 0;
+
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &flags);
+	if (dasd_eckd_validate_server(device, flags)
+	    == -EAGAIN) {
+		/* schedule worker again if failed */
+		schedule_work(&device->kick_validate);
+		return;
+	}
+
+	dasd_put_device(device);
+}
+
+static void dasd_eckd_kick_validate_server(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* exit if device not online or in offline processing */
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
+	   device->state < DASD_STATE_ONLINE) {
+		dasd_put_device(device);
+		return;
+	}
+	/* queue call to do_validate_server to the kernel event daemon. */
+	if (!schedule_work(&device->kick_validate))
+		dasd_put_device(device);
+}
+
+/*
+ * Check device characteristics.
+ * If the device is accessible using ECKD discipline, the device is enabled.
+ */
+static int
+dasd_eckd_check_characteristics(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct dasd_block *block;
+	struct dasd_uid temp_uid;
+	int rc, i;
+	int readonly;
+	unsigned long value;
+
+	/* setup work queue for validate server*/
+	INIT_WORK(&device->kick_validate, dasd_eckd_do_validate_server);
+	/* setup work queue for summary unit check */
+	INIT_WORK(&device->suc_work, dasd_alias_handle_summary_unit_check);
+
+	if (!ccw_device_is_pathgroup(device->cdev)) {
+		dev_warn(&device->cdev->dev,
+			 "A channel path group could not be established\n");
+		return -EIO;
+	}
+	if (!ccw_device_is_multipath(device->cdev)) {
+		dev_info(&device->cdev->dev,
+			 "The DASD is not operating in multipath mode\n");
+	}
+	if (!private) {
+		private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
+		if (!private) {
+			dev_warn(&device->cdev->dev,
+				 "Allocating memory for private DASD data "
+				 "failed\n");
+			return -ENOMEM;
+		}
+		device->private = private;
+	} else {
+		memset(private, 0, sizeof(*private));
+	}
+	/* Invalidate status of initial analysis. */
+	private->init_cqr_status = -1;
+	/* Set default cache operations. */
+	private->attrib.operation = DASD_NORMAL_CACHE;
+	private->attrib.nr_cyl = 0;
+
+	/* Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc)
+		goto out_err1;
+
+	/* set some default values */
+	device->default_expires = DASD_EXPIRES;
+	device->default_retries = DASD_RETRIES;
+	device->path_thrhld = DASD_ECKD_PATH_THRHLD;
+	device->path_interval = DASD_ECKD_PATH_INTERVAL;
+
+	if (private->gneq) {
+		value = 1;
+		for (i = 0; i < private->gneq->timeout.value; i++)
+			value = 10 * value;
+		value = value * private->gneq->timeout.number;
+		/* do not accept useless values */
+		if (value != 0 && value <= DASD_EXPIRES_MAX)
+			device->default_expires = value;
+	}
+
+	dasd_eckd_get_uid(device, &temp_uid);
+	if (temp_uid.type == UA_BASE_DEVICE) {
+		block = dasd_alloc_block();
+		if (IS_ERR(block)) {
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+					"could not allocate dasd "
+					"block structure");
+			rc = PTR_ERR(block);
+			goto out_err1;
+		}
+		device->block = block;
+		block->base = device;
+	}
+
+	/* register lcu with alias handling, enable PAV */
+	rc = dasd_alias_make_device_known_to_lcu(device);
+	if (rc)
+		goto out_err2;
+
+	dasd_eckd_validate_server(device, 0);
+
+	/* device may report different configuration data after LCU setup */
+	rc = dasd_eckd_read_conf(device);
+	if (rc)
+		goto out_err3;
+
+	/* Read Feature Codes */
+	dasd_eckd_read_features(device);
+
+	/* Read Device Characteristics */
+	rc = dasd_generic_read_dev_chars(device, DASD_ECKD_MAGIC,
+					 &private->rdc_data, 64);
+	if (rc) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+				"Read device characteristic failed, rc=%d", rc);
+		goto out_err3;
+	}
+
+	if ((device->features & DASD_FEATURE_USERAW) &&
+	    !(private->rdc_data.facilities.RT_in_LR)) {
+		dev_err(&device->cdev->dev, "The storage server does not "
+			"support raw-track access\n");
+		rc = -EINVAL;
+		goto out_err3;
+	}
+
+	/* find the valid cylinder size */
+	if (private->rdc_data.no_cyl == LV_COMPAT_CYL &&
+	    private->rdc_data.long_no_cyl)
+		private->real_cyl = private->rdc_data.long_no_cyl;
+	else
+		private->real_cyl = private->rdc_data.no_cyl;
+
+	private->fcx_max_data = get_fcx_max_data(device);
+
+	readonly = dasd_device_is_ro(device);
+	if (readonly)
+		set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+
+	dev_info(&device->cdev->dev, "New DASD %04X/%02X (CU %04X/%02X) "
+		 "with %d cylinders, %d heads, %d sectors%s\n",
+		 private->rdc_data.dev_type,
+		 private->rdc_data.dev_model,
+		 private->rdc_data.cu_type,
+		 private->rdc_data.cu_model.model,
+		 private->real_cyl,
+		 private->rdc_data.trk_per_cyl,
+		 private->rdc_data.sec_per_trk,
+		 readonly ? ", read-only device" : "");
+	return 0;
+
+out_err3:
+	dasd_alias_disconnect_device_from_lcu(device);
+out_err2:
+	dasd_free_block(device->block);
+	device->block = NULL;
+out_err1:
+	dasd_eckd_clear_conf_data(device);
+	kfree(device->private);
+	device->private = NULL;
+	return rc;
+}
+
+static void dasd_eckd_uncheck_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	if (!private)
+		return;
+
+	dasd_alias_disconnect_device_from_lcu(device);
+	private->ned = NULL;
+	private->sneq = NULL;
+	private->vdsneq = NULL;
+	private->gneq = NULL;
+	dasd_eckd_clear_conf_data(device);
+}
+
+static struct dasd_ccw_req *
+dasd_eckd_analysis_ccw(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct eckd_count *count_data;
+	struct LO_eckd_data *LO_data;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int cplength, datasize;
+	int i;
+
+	cplength = 8;
+	datasize = sizeof(struct DE_eckd_data) + 2*sizeof(struct LO_eckd_data);
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize, device,
+				   NULL);
+	if (IS_ERR(cqr))
+		return cqr;
+	ccw = cqr->cpaddr;
+	/* Define extent for the first 3 tracks. */
+	define_extent(ccw++, cqr->data, 0, 2,
+		      DASD_ECKD_CCW_READ_COUNT, device, 0);
+	LO_data = cqr->data + sizeof(struct DE_eckd_data);
+	/* Locate record for the first 4 records on track 0. */
+	ccw[-1].flags |= CCW_FLAG_CC;
+	locate_record(ccw++, LO_data++, 0, 0, 4,
+		      DASD_ECKD_CCW_READ_COUNT, device, 0);
+
+	count_data = private->count_area;
+	for (i = 0; i < 4; i++) {
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
+		ccw->flags = 0;
+		ccw->count = 8;
+		ccw->cda = (__u32)(addr_t) count_data;
+		ccw++;
+		count_data++;
+	}
+
+	/* Locate record for the first record on track 2. */
+	ccw[-1].flags |= CCW_FLAG_CC;
+	locate_record(ccw++, LO_data++, 2, 0, 1,
+		      DASD_ECKD_CCW_READ_COUNT, device, 0);
+	/* Read count ccw. */
+	ccw[-1].flags |= CCW_FLAG_CC;
+	ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
+	ccw->flags = 0;
+	ccw->count = 8;
+	ccw->cda = (__u32)(addr_t) count_data;
+
+	cqr->block = NULL;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->retries = 255;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+/* differentiate between 'no record found' and any other error */
+static int dasd_eckd_analysis_evaluation(struct dasd_ccw_req *init_cqr)
+{
+	char *sense;
+	if (init_cqr->status == DASD_CQR_DONE)
+		return INIT_CQR_OK;
+	else if (init_cqr->status == DASD_CQR_NEED_ERP ||
+		 init_cqr->status == DASD_CQR_FAILED) {
+		sense = dasd_get_sense(&init_cqr->irb);
+		if (sense && (sense[1] & SNS1_NO_REC_FOUND))
+			return INIT_CQR_UNFORMATTED;
+		else
+			return INIT_CQR_ERROR;
+	} else
+		return INIT_CQR_ERROR;
+}
+
+/*
+ * This is the callback function for the init_analysis cqr. It saves
+ * the status of the initial analysis ccw before it frees it and kicks
+ * the device to continue the startup sequence. This will call
+ * dasd_eckd_do_analysis again (if the devices has not been marked
+ * for deletion in the meantime).
+ */
+static void dasd_eckd_analysis_callback(struct dasd_ccw_req *init_cqr,
+					void *data)
+{
+	struct dasd_device *device = init_cqr->startdev;
+	struct dasd_eckd_private *private = device->private;
+
+	private->init_cqr_status = dasd_eckd_analysis_evaluation(init_cqr);
+	dasd_sfree_request(init_cqr, device);
+	dasd_kick_device(device);
+}
+
+static int dasd_eckd_start_analysis(struct dasd_block *block)
+{
+	struct dasd_ccw_req *init_cqr;
+
+	init_cqr = dasd_eckd_analysis_ccw(block->base);
+	if (IS_ERR(init_cqr))
+		return PTR_ERR(init_cqr);
+	init_cqr->callback = dasd_eckd_analysis_callback;
+	init_cqr->callback_data = NULL;
+	init_cqr->expires = 5*HZ;
+	/* first try without ERP, so we can later handle unformatted
+	 * devices as special case
+	 */
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &init_cqr->flags);
+	init_cqr->retries = 0;
+	dasd_add_request_head(init_cqr);
+	return -EAGAIN;
+}
+
+static int dasd_eckd_end_analysis(struct dasd_block *block)
+{
+	struct dasd_device *device = block->base;
+	struct dasd_eckd_private *private = device->private;
+	struct eckd_count *count_area;
+	unsigned int sb, blk_per_trk;
+	int status, i;
+	struct dasd_ccw_req *init_cqr;
+
+	status = private->init_cqr_status;
+	private->init_cqr_status = -1;
+	if (status == INIT_CQR_ERROR) {
+		/* try again, this time with full ERP */
+		init_cqr = dasd_eckd_analysis_ccw(device);
+		dasd_sleep_on(init_cqr);
+		status = dasd_eckd_analysis_evaluation(init_cqr);
+		dasd_sfree_request(init_cqr, device);
+	}
+
+	if (device->features & DASD_FEATURE_USERAW) {
+		block->bp_block = DASD_RAW_BLOCKSIZE;
+		blk_per_trk = DASD_RAW_BLOCK_PER_TRACK;
+		block->s2b_shift = 3;
+		goto raw;
+	}
+
+	if (status == INIT_CQR_UNFORMATTED) {
+		dev_warn(&device->cdev->dev, "The DASD is not formatted\n");
+		return -EMEDIUMTYPE;
+	} else if (status == INIT_CQR_ERROR) {
+		dev_err(&device->cdev->dev,
+			"Detecting the DASD disk layout failed because "
+			"of an I/O error\n");
+		return -EIO;
+	}
+
+	private->uses_cdl = 1;
+	/* Check Track 0 for Compatible Disk Layout */
+	count_area = NULL;
+	for (i = 0; i < 3; i++) {
+		if (private->count_area[i].kl != 4 ||
+		    private->count_area[i].dl != dasd_eckd_cdl_reclen(i) - 4 ||
+		    private->count_area[i].cyl != 0 ||
+		    private->count_area[i].head != count_area_head[i] ||
+		    private->count_area[i].record != count_area_rec[i]) {
+			private->uses_cdl = 0;
+			break;
+		}
+	}
+	if (i == 3)
+		count_area = &private->count_area[4];
+
+	if (private->uses_cdl == 0) {
+		for (i = 0; i < 5; i++) {
+			if ((private->count_area[i].kl != 0) ||
+			    (private->count_area[i].dl !=
+			     private->count_area[0].dl) ||
+			    private->count_area[i].cyl !=  0 ||
+			    private->count_area[i].head != count_area_head[i] ||
+			    private->count_area[i].record != count_area_rec[i])
+				break;
+		}
+		if (i == 5)
+			count_area = &private->count_area[0];
+	} else {
+		if (private->count_area[3].record == 1)
+			dev_warn(&device->cdev->dev,
+				 "Track 0 has no records following the VTOC\n");
+	}
+
+	if (count_area != NULL && count_area->kl == 0) {
+		/* we found notthing violating our disk layout */
+		if (dasd_check_blocksize(count_area->dl) == 0)
+			block->bp_block = count_area->dl;
+	}
+	if (block->bp_block == 0) {
+		dev_warn(&device->cdev->dev,
+			 "The disk layout of the DASD is not supported\n");
+		return -EMEDIUMTYPE;
+	}
+	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
+	for (sb = 512; sb < block->bp_block; sb = sb << 1)
+		block->s2b_shift++;
+
+	blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);
+
+raw:
+	block->blocks = ((unsigned long) private->real_cyl *
+			  private->rdc_data.trk_per_cyl *
+			  blk_per_trk);
+
+	dev_info(&device->cdev->dev,
+		 "DASD with %u KB/block, %lu KB total size, %u KB/track, "
+		 "%s\n", (block->bp_block >> 10),
+		 (((unsigned long) private->real_cyl *
+		   private->rdc_data.trk_per_cyl *
+		   blk_per_trk * (block->bp_block >> 9)) >> 1),
+		 ((blk_per_trk * block->bp_block) >> 10),
+		 private->uses_cdl ?
+		 "compatible disk layout" : "linux disk layout");
+
+	return 0;
+}
+
+static int dasd_eckd_do_analysis(struct dasd_block *block)
+{
+	struct dasd_eckd_private *private = block->base->private;
+
+	if (private->init_cqr_status < 0)
+		return dasd_eckd_start_analysis(block);
+	else
+		return dasd_eckd_end_analysis(block);
+}
+
+static int dasd_eckd_basic_to_ready(struct dasd_device *device)
+{
+	return dasd_alias_add_device(device);
+};
+
+static int dasd_eckd_online_to_ready(struct dasd_device *device)
+{
+	if (cancel_work_sync(&device->reload_device))
+		dasd_put_device(device);
+	if (cancel_work_sync(&device->kick_validate))
+		dasd_put_device(device);
+
+	return 0;
+};
+
+static int dasd_eckd_basic_to_known(struct dasd_device *device)
+{
+	return dasd_alias_remove_device(device);
+};
+
+static int
+dasd_eckd_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
+{
+	struct dasd_eckd_private *private = block->base->private;
+
+	if (dasd_check_blocksize(block->bp_block) == 0) {
+		geo->sectors = recs_per_track(&private->rdc_data,
+					      0, block->bp_block);
+	}
+	geo->cylinders = private->rdc_data.no_cyl;
+	geo->heads = private->rdc_data.trk_per_cyl;
+	return 0;
+}
+
+/*
+ * Build the TCW request for the format check
+ */
+static struct dasd_ccw_req *
+dasd_eckd_build_check_tcw(struct dasd_device *base, struct format_data_t *fdata,
+			  int enable_pav, struct eckd_count *fmt_buffer,
+			  int rpt)
+{
+	struct dasd_eckd_private *start_priv;
+	struct dasd_device *startdev = NULL;
+	struct tidaw *last_tidaw = NULL;
+	struct dasd_ccw_req *cqr;
+	struct itcw *itcw;
+	int itcw_size;
+	int count;
+	int rc;
+	int i;
+
+	if (enable_pav)
+		startdev = dasd_alias_get_start_dev(base);
+
+	if (!startdev)
+		startdev = base;
+
+	start_priv = startdev->private;
+
+	count = rpt * (fdata->stop_unit - fdata->start_unit + 1);
+
+	/*
+	 * we're adding 'count' amount of tidaw to the itcw.
+	 * calculate the corresponding itcw_size
+	 */
+	itcw_size = itcw_calc_size(0, count, 0);
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
+				   NULL);
+	if (IS_ERR(cqr))
+		return cqr;
+
+	start_priv->count++;
+
+	itcw = itcw_init(cqr->data, itcw_size, ITCW_OP_READ, 0, count, 0);
+	if (IS_ERR(itcw)) {
+		rc = -EINVAL;
+		goto out_err;
+	}
+
+	cqr->cpaddr = itcw_get_tcw(itcw);
+	rc = prepare_itcw(itcw, fdata->start_unit, fdata->stop_unit,
+			  DASD_ECKD_CCW_READ_COUNT_MT, base, startdev, 0, count,
+			  sizeof(struct eckd_count),
+			  count * sizeof(struct eckd_count), 0, rpt);
+	if (rc)
+		goto out_err;
+
+	for (i = 0; i < count; i++) {
+		last_tidaw = itcw_add_tidaw(itcw, 0, fmt_buffer++,
+					    sizeof(struct eckd_count));
+		if (IS_ERR(last_tidaw)) {
+			rc = -EINVAL;
+			goto out_err;
+		}
+	}
+
+	last_tidaw->flags |= TIDAW_FLAGS_LAST;
+	itcw_finalize(itcw);
+
+	cqr->cpmode = 1;
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->basedev = base;
+	cqr->retries = startdev->default_retries;
+	cqr->expires = startdev->default_expires * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	/* Set flags to suppress output for expected errors */
+	set_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
+	set_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags);
+
+	return cqr;
+
+out_err:
+	dasd_sfree_request(cqr, startdev);
+
+	return ERR_PTR(rc);
+}
+
+/*
+ * Build the CCW request for the format check
+ */
+static struct dasd_ccw_req *
+dasd_eckd_build_check(struct dasd_device *base, struct format_data_t *fdata,
+		      int enable_pav, struct eckd_count *fmt_buffer, int rpt)
+{
+	struct dasd_eckd_private *start_priv;
+	struct dasd_eckd_private *base_priv;
+	struct dasd_device *startdev = NULL;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	void *data;
+	int cplength, datasize;
+	int use_prefix;
+	int count;
+	int i;
+
+	if (enable_pav)
+		startdev = dasd_alias_get_start_dev(base);
+
+	if (!startdev)
+		startdev = base;
+
+	start_priv = startdev->private;
+	base_priv = base->private;
+
+	count = rpt * (fdata->stop_unit - fdata->start_unit + 1);
+
+	use_prefix = base_priv->features.feature[8] & 0x01;
+
+	if (use_prefix) {
+		cplength = 1;
+		datasize = sizeof(struct PFX_eckd_data);
+	} else {
+		cplength = 2;
+		datasize = sizeof(struct DE_eckd_data) +
+			sizeof(struct LO_eckd_data);
+	}
+	cplength += count;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
+				   startdev, NULL);
+	if (IS_ERR(cqr))
+		return cqr;
+
+	start_priv->count++;
+	data = cqr->data;
+	ccw = cqr->cpaddr;
+
+	if (use_prefix) {
+		prefix_LRE(ccw++, data, fdata->start_unit, fdata->stop_unit,
+			   DASD_ECKD_CCW_READ_COUNT, base, startdev, 1, 0,
+			   count, 0, 0);
+	} else {
+		define_extent(ccw++, data, fdata->start_unit, fdata->stop_unit,
+			      DASD_ECKD_CCW_READ_COUNT, startdev, 0);
+
+		data += sizeof(struct DE_eckd_data);
+		ccw[-1].flags |= CCW_FLAG_CC;
+
+		locate_record(ccw++, data, fdata->start_unit, 0, count,
+			      DASD_ECKD_CCW_READ_COUNT, base, 0);
+	}
+
+	for (i = 0; i < count; i++) {
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
+		ccw->flags = CCW_FLAG_SLI;
+		ccw->count = 8;
+		ccw->cda = (__u32)(addr_t) fmt_buffer;
+		ccw++;
+		fmt_buffer++;
+	}
+
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->basedev = base;
+	cqr->retries = DASD_RETRIES;
+	cqr->expires = startdev->default_expires * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	/* Set flags to suppress output for expected errors */
+	set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+
+	return cqr;
+}
+
+static struct dasd_ccw_req *
+dasd_eckd_build_format(struct dasd_device *base,
+		       struct format_data_t *fdata,
+		       int enable_pav)
+{
+	struct dasd_eckd_private *base_priv;
+	struct dasd_eckd_private *start_priv;
+	struct dasd_device *startdev = NULL;
+	struct dasd_ccw_req *fcp;
+	struct eckd_count *ect;
+	struct ch_t address;
+	struct ccw1 *ccw;
+	void *data;
+	int rpt;
+	int cplength, datasize;
+	int i, j;
+	int intensity = 0;
+	int r0_perm;
+	int nr_tracks;
+	int use_prefix;
+
+	if (enable_pav)
+		startdev = dasd_alias_get_start_dev(base);
+
+	if (!startdev)
+		startdev = base;
+
+	start_priv = startdev->private;
+	base_priv = base->private;
+
+	rpt = recs_per_track(&base_priv->rdc_data, 0, fdata->blksize);
+
+	nr_tracks = fdata->stop_unit - fdata->start_unit + 1;
+
+	/*
+	 * fdata->intensity is a bit string that tells us what to do:
+	 *   Bit 0: write record zero
+	 *   Bit 1: write home address, currently not supported
+	 *   Bit 2: invalidate tracks
+	 *   Bit 3: use OS/390 compatible disk layout (cdl)
+	 *   Bit 4: do not allow storage subsystem to modify record zero
+	 * Only some bit combinations do make sense.
+	 */
+	if (fdata->intensity & 0x10) {
+		r0_perm = 0;
+		intensity = fdata->intensity & ~0x10;
+	} else {
+		r0_perm = 1;
+		intensity = fdata->intensity;
+	}
+
+	use_prefix = base_priv->features.feature[8] & 0x01;
+
+	switch (intensity) {
+	case 0x00:	/* Normal format */
+	case 0x08:	/* Normal format, use cdl. */
+		cplength = 2 + (rpt*nr_tracks);
+		if (use_prefix)
+			datasize = sizeof(struct PFX_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				rpt * nr_tracks * sizeof(struct eckd_count);
+		else
+			datasize = sizeof(struct DE_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				rpt * nr_tracks * sizeof(struct eckd_count);
+		break;
+	case 0x01:	/* Write record zero and format track. */
+	case 0x09:	/* Write record zero and format track, use cdl. */
+		cplength = 2 + rpt * nr_tracks;
+		if (use_prefix)
+			datasize = sizeof(struct PFX_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				sizeof(struct eckd_count) +
+				rpt * nr_tracks * sizeof(struct eckd_count);
+		else
+			datasize = sizeof(struct DE_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				sizeof(struct eckd_count) +
+				rpt * nr_tracks * sizeof(struct eckd_count);
+		break;
+	case 0x04:	/* Invalidate track. */
+	case 0x0c:	/* Invalidate track, use cdl. */
+		cplength = 3;
+		if (use_prefix)
+			datasize = sizeof(struct PFX_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				sizeof(struct eckd_count);
+		else
+			datasize = sizeof(struct DE_eckd_data) +
+				sizeof(struct LO_eckd_data) +
+				sizeof(struct eckd_count);
+		break;
+	default:
+		dev_warn(&startdev->cdev->dev,
+			 "An I/O control call used incorrect flags 0x%x\n",
+			 fdata->intensity);
+		return ERR_PTR(-EINVAL);
+	}
+	/* Allocate the format ccw request. */
+	fcp = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
+				   datasize, startdev, NULL);
+	if (IS_ERR(fcp))
+		return fcp;
+
+	start_priv->count++;
+	data = fcp->data;
+	ccw = fcp->cpaddr;
+
+	switch (intensity & ~0x08) {
+	case 0x00: /* Normal format. */
+		if (use_prefix) {
+			prefix(ccw++, (struct PFX_eckd_data *) data,
+			       fdata->start_unit, fdata->stop_unit,
+			       DASD_ECKD_CCW_WRITE_CKD, base, startdev);
+			/* grant subsystem permission to format R0 */
+			if (r0_perm)
+				((struct PFX_eckd_data *)data)
+					->define_extent.ga_extended |= 0x04;
+			data += sizeof(struct PFX_eckd_data);
+		} else {
+			define_extent(ccw++, (struct DE_eckd_data *) data,
+				      fdata->start_unit, fdata->stop_unit,
+				      DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
+			/* grant subsystem permission to format R0 */
+			if (r0_perm)
+				((struct DE_eckd_data *) data)
+					->ga_extended |= 0x04;
+			data += sizeof(struct DE_eckd_data);
+		}
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, (struct LO_eckd_data *) data,
+			      fdata->start_unit, 0, rpt*nr_tracks,
+			      DASD_ECKD_CCW_WRITE_CKD, base,
+			      fdata->blksize);
+		data += sizeof(struct LO_eckd_data);
+		break;
+	case 0x01: /* Write record zero + format track. */
+		if (use_prefix) {
+			prefix(ccw++, (struct PFX_eckd_data *) data,
+			       fdata->start_unit, fdata->stop_unit,
+			       DASD_ECKD_CCW_WRITE_RECORD_ZERO,
+			       base, startdev);
+			data += sizeof(struct PFX_eckd_data);
+		} else {
+			define_extent(ccw++, (struct DE_eckd_data *) data,
+			       fdata->start_unit, fdata->stop_unit,
+			       DASD_ECKD_CCW_WRITE_RECORD_ZERO, startdev, 0);
+			data += sizeof(struct DE_eckd_data);
+		}
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, (struct LO_eckd_data *) data,
+			      fdata->start_unit, 0, rpt * nr_tracks + 1,
+			      DASD_ECKD_CCW_WRITE_RECORD_ZERO, base,
+			      base->block->bp_block);
+		data += sizeof(struct LO_eckd_data);
+		break;
+	case 0x04: /* Invalidate track. */
+		if (use_prefix) {
+			prefix(ccw++, (struct PFX_eckd_data *) data,
+			       fdata->start_unit, fdata->stop_unit,
+			       DASD_ECKD_CCW_WRITE_CKD, base, startdev);
+			data += sizeof(struct PFX_eckd_data);
+		} else {
+			define_extent(ccw++, (struct DE_eckd_data *) data,
+			       fdata->start_unit, fdata->stop_unit,
+			       DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
+			data += sizeof(struct DE_eckd_data);
+		}
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, (struct LO_eckd_data *) data,
+			      fdata->start_unit, 0, 1,
+			      DASD_ECKD_CCW_WRITE_CKD, base, 8);
+		data += sizeof(struct LO_eckd_data);
+		break;
+	}
+
+	for (j = 0; j < nr_tracks; j++) {
+		/* calculate cylinder and head for the current track */
+		set_ch_t(&address,
+			 (fdata->start_unit + j) /
+			 base_priv->rdc_data.trk_per_cyl,
+			 (fdata->start_unit + j) %
+			 base_priv->rdc_data.trk_per_cyl);
+		if (intensity & 0x01) {	/* write record zero */
+			ect = (struct eckd_count *) data;
+			data += sizeof(struct eckd_count);
+			ect->cyl = address.cyl;
+			ect->head = address.head;
+			ect->record = 0;
+			ect->kl = 0;
+			ect->dl = 8;
+			ccw[-1].flags |= CCW_FLAG_CC;
+			ccw->cmd_code = DASD_ECKD_CCW_WRITE_RECORD_ZERO;
+			ccw->flags = CCW_FLAG_SLI;
+			ccw->count = 8;
+			ccw->cda = (__u32)(addr_t) ect;
+			ccw++;
+		}
+		if ((intensity & ~0x08) & 0x04) {	/* erase track */
+			ect = (struct eckd_count *) data;
+			data += sizeof(struct eckd_count);
+			ect->cyl = address.cyl;
+			ect->head = address.head;
+			ect->record = 1;
+			ect->kl = 0;
+			ect->dl = 0;
+			ccw[-1].flags |= CCW_FLAG_CC;
+			ccw->cmd_code = DASD_ECKD_CCW_WRITE_CKD;
+			ccw->flags = CCW_FLAG_SLI;
+			ccw->count = 8;
+			ccw->cda = (__u32)(addr_t) ect;
+		} else {		/* write remaining records */
+			for (i = 0; i < rpt; i++) {
+				ect = (struct eckd_count *) data;
+				data += sizeof(struct eckd_count);
+				ect->cyl = address.cyl;
+				ect->head = address.head;
+				ect->record = i + 1;
+				ect->kl = 0;
+				ect->dl = fdata->blksize;
+				/*
+				 * Check for special tracks 0-1
+				 * when formatting CDL
+				 */
+				if ((intensity & 0x08) &&
+				    address.cyl == 0 && address.head == 0) {
+					if (i < 3) {
+						ect->kl = 4;
+						ect->dl = sizes_trk0[i] - 4;
+					}
+				}
+				if ((intensity & 0x08) &&
+				    address.cyl == 0 && address.head == 1) {
+					ect->kl = 44;
+					ect->dl = LABEL_SIZE - 44;
+				}
+				ccw[-1].flags |= CCW_FLAG_CC;
+				if (i != 0 || j == 0)
+					ccw->cmd_code =
+						DASD_ECKD_CCW_WRITE_CKD;
+				else
+					ccw->cmd_code =
+						DASD_ECKD_CCW_WRITE_CKD_MT;
+				ccw->flags = CCW_FLAG_SLI;
+				ccw->count = 8;
+				ccw->cda = (__u32)(addr_t) ect;
+				ccw++;
+			}
+		}
+	}
+
+	fcp->startdev = startdev;
+	fcp->memdev = startdev;
+	fcp->basedev = base;
+	fcp->retries = 256;
+	fcp->expires = startdev->default_expires * HZ;
+	fcp->buildclk = get_tod_clock();
+	fcp->status = DASD_CQR_FILLED;
+
+	return fcp;
+}
+
+/*
+ * Wrapper function to build a CCW request depending on input data
+ */
+static struct dasd_ccw_req *
+dasd_eckd_format_build_ccw_req(struct dasd_device *base,
+			       struct format_data_t *fdata, int enable_pav,
+			       int tpm, struct eckd_count *fmt_buffer, int rpt)
+{
+	struct dasd_ccw_req *ccw_req;
+
+	if (!fmt_buffer) {
+		ccw_req = dasd_eckd_build_format(base, fdata, enable_pav);
+	} else {
+		if (tpm)
+			ccw_req = dasd_eckd_build_check_tcw(base, fdata,
+							    enable_pav,
+							    fmt_buffer, rpt);
+		else
+			ccw_req = dasd_eckd_build_check(base, fdata, enable_pav,
+							fmt_buffer, rpt);
+	}
+
+	return ccw_req;
+}
+
+/*
+ * Sanity checks on format_data
+ */
+static int dasd_eckd_format_sanity_checks(struct dasd_device *base,
+					  struct format_data_t *fdata)
+{
+	struct dasd_eckd_private *private = base->private;
+
+	if (fdata->start_unit >=
+	    (private->real_cyl * private->rdc_data.trk_per_cyl)) {
+		dev_warn(&base->cdev->dev,
+			 "Start track number %u used in formatting is too big\n",
+			 fdata->start_unit);
+		return -EINVAL;
+	}
+	if (fdata->stop_unit >=
+	    (private->real_cyl * private->rdc_data.trk_per_cyl)) {
+		dev_warn(&base->cdev->dev,
+			 "Stop track number %u used in formatting is too big\n",
+			 fdata->stop_unit);
+		return -EINVAL;
+	}
+	if (fdata->start_unit > fdata->stop_unit) {
+		dev_warn(&base->cdev->dev,
+			 "Start track %u used in formatting exceeds end track\n",
+			 fdata->start_unit);
+		return -EINVAL;
+	}
+	if (dasd_check_blocksize(fdata->blksize) != 0) {
+		dev_warn(&base->cdev->dev,
+			 "The DASD cannot be formatted with block size %u\n",
+			 fdata->blksize);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * This function will process format_data originally coming from an IOCTL
+ */
+static int dasd_eckd_format_process_data(struct dasd_device *base,
+					 struct format_data_t *fdata,
+					 int enable_pav, int tpm,
+					 struct eckd_count *fmt_buffer, int rpt,
+					 struct irb *irb)
+{
+	struct dasd_eckd_private *private = base->private;
+	struct dasd_ccw_req *cqr, *n;
+	struct list_head format_queue;
+	struct dasd_device *device;
+	char *sense = NULL;
+	int old_start, old_stop, format_step;
+	int step, retry;
+	int rc;
+
+	rc = dasd_eckd_format_sanity_checks(base, fdata);
+	if (rc)
+		return rc;
+
+	INIT_LIST_HEAD(&format_queue);
+
+	old_start = fdata->start_unit;
+	old_stop = fdata->stop_unit;
+
+	if (!tpm && fmt_buffer != NULL) {
+		/* Command Mode / Format Check */
+		format_step = 1;
+	} else if (tpm && fmt_buffer != NULL) {
+		/* Transport Mode / Format Check */
+		format_step = DASD_CQR_MAX_CCW / rpt;
+	} else {
+		/* Normal Formatting */
+		format_step = DASD_CQR_MAX_CCW /
+			recs_per_track(&private->rdc_data, 0, fdata->blksize);
+	}
+
+	do {
+		retry = 0;
+		while (fdata->start_unit <= old_stop) {
+			step = fdata->stop_unit - fdata->start_unit + 1;
+			if (step > format_step) {
+				fdata->stop_unit =
+					fdata->start_unit + format_step - 1;
+			}
+
+			cqr = dasd_eckd_format_build_ccw_req(base, fdata,
+							     enable_pav, tpm,
+							     fmt_buffer, rpt);
+			if (IS_ERR(cqr)) {
+				rc = PTR_ERR(cqr);
+				if (rc == -ENOMEM) {
+					if (list_empty(&format_queue))
+						goto out;
+					/*
+					 * not enough memory available, start
+					 * requests retry after first requests
+					 * were finished
+					 */
+					retry = 1;
+					break;
+				}
+				goto out_err;
+			}
+			list_add_tail(&cqr->blocklist, &format_queue);
+
+			if (fmt_buffer) {
+				step = fdata->stop_unit - fdata->start_unit + 1;
+				fmt_buffer += rpt * step;
+			}
+			fdata->start_unit = fdata->stop_unit + 1;
+			fdata->stop_unit = old_stop;
+		}
+
+		rc = dasd_sleep_on_queue(&format_queue);
+
+out_err:
+		list_for_each_entry_safe(cqr, n, &format_queue, blocklist) {
+			device = cqr->startdev;
+			private = device->private;
+
+			if (cqr->status == DASD_CQR_FAILED) {
+				/*
+				 * Only get sense data if called by format
+				 * check
+				 */
+				if (fmt_buffer && irb) {
+					sense = dasd_get_sense(&cqr->irb);
+					memcpy(irb, &cqr->irb, sizeof(*irb));
+				}
+				rc = -EIO;
+			}
+			list_del_init(&cqr->blocklist);
+			dasd_sfree_request(cqr, device);
+			private->count--;
+		}
+
+		if (rc && rc != -EIO)
+			goto out;
+		if (rc == -EIO) {
+			/*
+			 * In case fewer than the expected records are on the
+			 * track, we will most likely get a 'No Record Found'
+			 * error (in command mode) or a 'File Protected' error
+			 * (in transport mode). Those particular cases shouldn't
+			 * pass the -EIO to the IOCTL, therefore reset the rc
+			 * and continue.
+			 */
+			if (sense &&
+			    (sense[1] & SNS1_NO_REC_FOUND ||
+			     sense[1] & SNS1_FILE_PROTECTED))
+				retry = 1;
+			else
+				goto out;
+		}
+
+	} while (retry);
+
+out:
+	fdata->start_unit = old_start;
+	fdata->stop_unit = old_stop;
+
+	return rc;
+}
+
+static int dasd_eckd_format_device(struct dasd_device *base,
+				   struct format_data_t *fdata, int enable_pav)
+{
+	return dasd_eckd_format_process_data(base, fdata, enable_pav, 0, NULL,
+					     0, NULL);
+}
+
+/*
+ * Helper function to count consecutive records of a single track.
+ */
+static int dasd_eckd_count_records(struct eckd_count *fmt_buffer, int start,
+				   int max)
+{
+	int head;
+	int i;
+
+	head = fmt_buffer[start].head;
+
+	/*
+	 * There are 3 conditions where we stop counting:
+	 * - if data reoccurs (same head and record may reoccur), which may
+	 *   happen due to the way DASD_ECKD_CCW_READ_COUNT works
+	 * - when the head changes, because we're iterating over several tracks
+	 *   then (DASD_ECKD_CCW_READ_COUNT_MT)
+	 * - when we've reached the end of sensible data in the buffer (the
+	 *   record will be 0 then)
+	 */
+	for (i = start; i < max; i++) {
+		if (i > start) {
+			if ((fmt_buffer[i].head == head &&
+			    fmt_buffer[i].record == 1) ||
+			    fmt_buffer[i].head != head ||
+			    fmt_buffer[i].record == 0)
+				break;
+		}
+	}
+
+	return i - start;
+}
+
+/*
+ * Evaluate a given range of tracks. Data like number of records, blocksize,
+ * record ids, and key length are compared with expected data.
+ *
+ * If a mismatch occurs, the corresponding error bit is set, as well as
+ * additional information, depending on the error.
+ */
+static void dasd_eckd_format_evaluate_tracks(struct eckd_count *fmt_buffer,
+					     struct format_check_t *cdata,
+					     int rpt_max, int rpt_exp,
+					     int trk_per_cyl, int tpm)
+{
+	struct ch_t geo;
+	int max_entries;
+	int count = 0;
+	int trkcount;
+	int blksize;
+	int pos = 0;
+	int i, j;
+	int kl;
+
+	trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
+	max_entries = trkcount * rpt_max;
+
+	for (i = cdata->expect.start_unit; i <= cdata->expect.stop_unit; i++) {
+		/* Calculate the correct next starting position in the buffer */
+		if (tpm) {
+			while (fmt_buffer[pos].record == 0 &&
+			       fmt_buffer[pos].dl == 0) {
+				if (pos++ > max_entries)
+					break;
+			}
+		} else {
+			if (i != cdata->expect.start_unit)
+				pos += rpt_max - count;
+		}
+
+		/* Calculate the expected geo values for the current track */
+		set_ch_t(&geo, i / trk_per_cyl, i % trk_per_cyl);
+
+		/* Count and check number of records */
+		count = dasd_eckd_count_records(fmt_buffer, pos, pos + rpt_max);
+
+		if (count < rpt_exp) {
+			cdata->result = DASD_FMT_ERR_TOO_FEW_RECORDS;
+			break;
+		}
+		if (count > rpt_exp) {
+			cdata->result = DASD_FMT_ERR_TOO_MANY_RECORDS;
+			break;
+		}
+
+		for (j = 0; j < count; j++, pos++) {
+			blksize = cdata->expect.blksize;
+			kl = 0;
+
+			/*
+			 * Set special values when checking CDL formatted
+			 * devices.
+			 */
+			if ((cdata->expect.intensity & 0x08) &&
+			    geo.cyl == 0 && geo.head == 0) {
+				if (j < 3) {
+					blksize = sizes_trk0[j] - 4;
+					kl = 4;
+				}
+			}
+			if ((cdata->expect.intensity & 0x08) &&
+			    geo.cyl == 0 && geo.head == 1) {
+				blksize = LABEL_SIZE - 44;
+				kl = 44;
+			}
+
+			/* Check blocksize */
+			if (fmt_buffer[pos].dl != blksize) {
+				cdata->result = DASD_FMT_ERR_BLKSIZE;
+				goto out;
+			}
+			/* Check if key length is 0 */
+			if (fmt_buffer[pos].kl != kl) {
+				cdata->result = DASD_FMT_ERR_KEY_LENGTH;
+				goto out;
+			}
+			/* Check if record_id is correct */
+			if (fmt_buffer[pos].cyl != geo.cyl ||
+			    fmt_buffer[pos].head != geo.head ||
+			    fmt_buffer[pos].record != (j + 1)) {
+				cdata->result = DASD_FMT_ERR_RECORD_ID;
+				goto out;
+			}
+		}
+	}
+
+out:
+	/*
+	 * In case of no errors, we need to decrease by one
+	 * to get the correct positions.
+	 */
+	if (!cdata->result) {
+		i--;
+		pos--;
+	}
+
+	cdata->unit = i;
+	cdata->num_records = count;
+	cdata->rec = fmt_buffer[pos].record;
+	cdata->blksize = fmt_buffer[pos].dl;
+	cdata->key_length = fmt_buffer[pos].kl;
+}
+
+/*
+ * Check the format of a range of tracks of a DASD.
+ */
+static int dasd_eckd_check_device_format(struct dasd_device *base,
+					 struct format_check_t *cdata,
+					 int enable_pav)
+{
+	struct dasd_eckd_private *private = base->private;
+	struct eckd_count *fmt_buffer;
+	struct irb irb;
+	int rpt_max, rpt_exp;
+	int fmt_buffer_size;
+	int trk_per_cyl;
+	int trkcount;
+	int tpm = 0;
+	int rc;
+
+	trk_per_cyl = private->rdc_data.trk_per_cyl;
+
+	/* Get maximum and expected amount of records per track */
+	rpt_max = recs_per_track(&private->rdc_data, 0, 512) + 1;
+	rpt_exp = recs_per_track(&private->rdc_data, 0, cdata->expect.blksize);
+
+	trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
+	fmt_buffer_size = trkcount * rpt_max * sizeof(struct eckd_count);
+
+	fmt_buffer = kzalloc(fmt_buffer_size, GFP_KERNEL | GFP_DMA);
+	if (!fmt_buffer)
+		return -ENOMEM;
+
+	/*
+	 * A certain FICON feature subset is needed to operate in transport
+	 * mode. Additionally, the support for transport mode is implicitly
+	 * checked by comparing the buffer size with fcx_max_data. As long as
+	 * the buffer size is smaller we can operate in transport mode and
+	 * process multiple tracks. If not, only one track at once is being
+	 * processed using command mode.
+	 */
+	if ((private->features.feature[40] & 0x04) &&
+	    fmt_buffer_size <= private->fcx_max_data)
+		tpm = 1;
+
+	rc = dasd_eckd_format_process_data(base, &cdata->expect, enable_pav,
+					   tpm, fmt_buffer, rpt_max, &irb);
+	if (rc && rc != -EIO)
+		goto out;
+	if (rc == -EIO) {
+		/*
+		 * If our first attempt with transport mode enabled comes back
+		 * with an incorrect length error, we're going to retry the
+		 * check with command mode.
+		 */
+		if (tpm && scsw_cstat(&irb.scsw) == 0x40) {
+			tpm = 0;
+			rc = dasd_eckd_format_process_data(base, &cdata->expect,
+							   enable_pav, tpm,
+							   fmt_buffer, rpt_max,
+							   &irb);
+			if (rc)
+				goto out;
+		} else {
+			goto out;
+		}
+	}
+
+	dasd_eckd_format_evaluate_tracks(fmt_buffer, cdata, rpt_max, rpt_exp,
+					 trk_per_cyl, tpm);
+
+out:
+	kfree(fmt_buffer);
+
+	return rc;
+}
+
+static void dasd_eckd_handle_terminated_request(struct dasd_ccw_req *cqr)
+{
+	if (cqr->retries < 0) {
+		cqr->status = DASD_CQR_FAILED;
+		return;
+	}
+	cqr->status = DASD_CQR_FILLED;
+	if (cqr->block && (cqr->startdev != cqr->block->base)) {
+		dasd_eckd_reset_ccw_to_base_io(cqr);
+		cqr->startdev = cqr->block->base;
+		cqr->lpm = dasd_path_get_opm(cqr->block->base);
+	}
+};
+
+static dasd_erp_fn_t
+dasd_eckd_erp_action(struct dasd_ccw_req * cqr)
+{
+	struct dasd_device *device = (struct dasd_device *) cqr->startdev;
+	struct ccw_device *cdev = device->cdev;
+
+	switch (cdev->id.cu_type) {
+	case 0x3990:
+	case 0x2105:
+	case 0x2107:
+	case 0x1750:
+		return dasd_3990_erp_action;
+	case 0x9343:
+	case 0x3880:
+	default:
+		return dasd_default_erp_action;
+	}
+}
+
+static dasd_erp_fn_t
+dasd_eckd_erp_postaction(struct dasd_ccw_req * cqr)
+{
+	return dasd_default_erp_postaction;
+}
+
+static void dasd_eckd_check_for_device_change(struct dasd_device *device,
+					      struct dasd_ccw_req *cqr,
+					      struct irb *irb)
+{
+	char mask;
+	char *sense = NULL;
+	struct dasd_eckd_private *private = device->private;
+
+	/* first of all check for state change pending interrupt */
+	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
+	if ((scsw_dstat(&irb->scsw) & mask) == mask) {
+		/*
+		 * for alias only, not in offline processing
+		 * and only if not suspended
+		 */
+		if (!device->block && private->lcu &&
+		    device->state == DASD_STATE_ONLINE &&
+		    !test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
+		    !test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
+			/* schedule worker to reload device */
+			dasd_reload_device(device);
+		}
+		dasd_generic_handle_state_change(device);
+		return;
+	}
+
+	sense = dasd_get_sense(irb);
+	if (!sense)
+		return;
+
+	/* summary unit check */
+	if ((sense[27] & DASD_SENSE_BIT_0) && (sense[7] == 0x0D) &&
+	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK)) {
+		if (test_and_set_bit(DASD_FLAG_SUC, &device->flags)) {
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "eckd suc: device already notified");
+			return;
+		}
+		sense = dasd_get_sense(irb);
+		if (!sense) {
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "eckd suc: no reason code available");
+			clear_bit(DASD_FLAG_SUC, &device->flags);
+			return;
+
+		}
+		private->suc_reason = sense[8];
+		DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x",
+			      "eckd handle summary unit check: reason",
+			      private->suc_reason);
+		dasd_get_device(device);
+		if (!schedule_work(&device->suc_work))
+			dasd_put_device(device);
+
+		return;
+	}
+
+	/* service information message SIM */
+	if (!cqr && !(sense[27] & DASD_SENSE_BIT_0) &&
+	    ((sense[6] & DASD_SIM_SENSE) == DASD_SIM_SENSE)) {
+		dasd_3990_erp_handle_sim(device, sense);
+		return;
+	}
+
+	/* loss of device reservation is handled via base devices only
+	 * as alias devices may be used with several bases
+	 */
+	if (device->block && (sense[27] & DASD_SENSE_BIT_0) &&
+	    (sense[7] == 0x3F) &&
+	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
+	    test_bit(DASD_FLAG_IS_RESERVED, &device->flags)) {
+		if (device->features & DASD_FEATURE_FAILONSLCK)
+			set_bit(DASD_FLAG_LOCK_STOLEN, &device->flags);
+		clear_bit(DASD_FLAG_IS_RESERVED, &device->flags);
+		dev_err(&device->cdev->dev,
+			"The device reservation was lost\n");
+	}
+}
+
+static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
+					       struct dasd_device *startdev,
+					       struct dasd_block *block,
+					       struct request *req,
+					       sector_t first_rec,
+					       sector_t last_rec,
+					       sector_t first_trk,
+					       sector_t last_trk,
+					       unsigned int first_offs,
+					       unsigned int last_offs,
+					       unsigned int blk_per_trk,
+					       unsigned int blksize)
+{
+	struct dasd_eckd_private *private;
+	unsigned long *idaws;
+	struct LO_eckd_data *LO_data;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst;
+	unsigned int off;
+	int count, cidaw, cplength, datasize;
+	sector_t recid;
+	unsigned char cmd, rcmd;
+	int use_prefix;
+	struct dasd_device *basedev;
+
+	basedev = block->base;
+	private = basedev->private;
+	if (rq_data_dir(req) == READ)
+		cmd = DASD_ECKD_CCW_READ_MT;
+	else if (rq_data_dir(req) == WRITE)
+		cmd = DASD_ECKD_CCW_WRITE_MT;
+	else
+		return ERR_PTR(-EINVAL);
+
+	/* Check struct bio and count the number of blocks for the request. */
+	count = 0;
+	cidaw = 0;
+	rq_for_each_segment(bv, req, iter) {
+		if (bv.bv_len & (blksize - 1))
+			/* Eckd can only do full blocks. */
+			return ERR_PTR(-EINVAL);
+		count += bv.bv_len >> (block->s2b_shift + 9);
+		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
+			cidaw += bv.bv_len >> (block->s2b_shift + 9);
+	}
+	/* Paranoia. */
+	if (count != last_rec - first_rec + 1)
+		return ERR_PTR(-EINVAL);
+
+	/* use the prefix command if available */
+	use_prefix = private->features.feature[8] & 0x01;
+	if (use_prefix) {
+		/* 1x prefix + number of blocks */
+		cplength = 2 + count;
+		/* 1x prefix + cidaws*sizeof(long) */
+		datasize = sizeof(struct PFX_eckd_data) +
+			sizeof(struct LO_eckd_data) +
+			cidaw * sizeof(unsigned long);
+	} else {
+		/* 1x define extent + 1x locate record + number of blocks */
+		cplength = 2 + count;
+		/* 1x define extent + 1x locate record + cidaws*sizeof(long) */
+		datasize = sizeof(struct DE_eckd_data) +
+			sizeof(struct LO_eckd_data) +
+			cidaw * sizeof(unsigned long);
+	}
+	/* Find out the number of additional locate record ccws for cdl. */
+	if (private->uses_cdl && first_rec < 2*blk_per_trk) {
+		if (last_rec >= 2*blk_per_trk)
+			count = 2*blk_per_trk - first_rec;
+		cplength += count;
+		datasize += count*sizeof(struct LO_eckd_data);
+	}
+	/* Allocate the ccw request. */
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
+				   startdev, blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+	ccw = cqr->cpaddr;
+	/* First ccw is define extent or prefix. */
+	if (use_prefix) {
+		if (prefix(ccw++, cqr->data, first_trk,
+			   last_trk, cmd, basedev, startdev) == -EAGAIN) {
+			/* Clock not in sync and XRC is enabled.
+			 * Try again later.
+			 */
+			dasd_sfree_request(cqr, startdev);
+			return ERR_PTR(-EAGAIN);
+		}
+		idaws = (unsigned long *) (cqr->data +
+					   sizeof(struct PFX_eckd_data));
+	} else {
+		if (define_extent(ccw++, cqr->data, first_trk,
+				  last_trk, cmd, basedev, 0) == -EAGAIN) {
+			/* Clock not in sync and XRC is enabled.
+			 * Try again later.
+			 */
+			dasd_sfree_request(cqr, startdev);
+			return ERR_PTR(-EAGAIN);
+		}
+		idaws = (unsigned long *) (cqr->data +
+					   sizeof(struct DE_eckd_data));
+	}
+	/* Build locate_record+read/write/ccws. */
+	LO_data = (struct LO_eckd_data *) (idaws + cidaw);
+	recid = first_rec;
+	if (private->uses_cdl == 0 || recid > 2*blk_per_trk) {
+		/* Only standard blocks so there is just one locate record. */
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, LO_data++, first_trk, first_offs + 1,
+			      last_rec - recid + 1, cmd, basedev, blksize);
+	}
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		if (dasd_page_cache) {
+			char *copy = kmem_cache_alloc(dasd_page_cache,
+						      GFP_DMA | __GFP_NOWARN);
+			if (copy && rq_data_dir(req) == WRITE)
+				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
+			if (copy)
+				dst = copy + bv.bv_offset;
+		}
+		for (off = 0; off < bv.bv_len; off += blksize) {
+			sector_t trkid = recid;
+			unsigned int recoffs = sector_div(trkid, blk_per_trk);
+			rcmd = cmd;
+			count = blksize;
+			/* Locate record for cdl special block ? */
+			if (private->uses_cdl && recid < 2*blk_per_trk) {
+				if (dasd_eckd_cdl_special(blk_per_trk, recid)){
+					rcmd |= 0x8;
+					count = dasd_eckd_cdl_reclen(recid);
+					if (count < blksize &&
+					    rq_data_dir(req) == READ)
+						memset(dst + count, 0xe5,
+						       blksize - count);
+				}
+				ccw[-1].flags |= CCW_FLAG_CC;
+				locate_record(ccw++, LO_data++,
+					      trkid, recoffs + 1,
+					      1, rcmd, basedev, count);
+			}
+			/* Locate record for standard blocks ? */
+			if (private->uses_cdl && recid == 2*blk_per_trk) {
+				ccw[-1].flags |= CCW_FLAG_CC;
+				locate_record(ccw++, LO_data++,
+					      trkid, recoffs + 1,
+					      last_rec - recid + 1,
+					      cmd, basedev, count);
+			}
+			/* Read/write ccw. */
+			ccw[-1].flags |= CCW_FLAG_CC;
+			ccw->cmd_code = rcmd;
+			ccw->count = count;
+			if (idal_is_needed(dst, blksize)) {
+				ccw->cda = (__u32)(addr_t) idaws;
+				ccw->flags = CCW_FLAG_IDA;
+				idaws = idal_create_words(idaws, dst, blksize);
+			} else {
+				ccw->cda = (__u32)(addr_t) dst;
+				ccw->flags = 0;
+			}
+			ccw++;
+			dst += blksize;
+			recid++;
+		}
+	}
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->block = block;
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
+	cqr->lpm = dasd_path_get_ppm(startdev);
+	cqr->retries = startdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
+					       struct dasd_device *startdev,
+					       struct dasd_block *block,
+					       struct request *req,
+					       sector_t first_rec,
+					       sector_t last_rec,
+					       sector_t first_trk,
+					       sector_t last_trk,
+					       unsigned int first_offs,
+					       unsigned int last_offs,
+					       unsigned int blk_per_trk,
+					       unsigned int blksize)
+{
+	unsigned long *idaws;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst, *idaw_dst;
+	unsigned int cidaw, cplength, datasize;
+	unsigned int tlf;
+	sector_t recid;
+	unsigned char cmd;
+	struct dasd_device *basedev;
+	unsigned int trkcount, count, count_to_trk_end;
+	unsigned int idaw_len, seg_len, part_len, len_to_track_end;
+	unsigned char new_track, end_idaw;
+	sector_t trkid;
+	unsigned int recoffs;
+
+	basedev = block->base;
+	if (rq_data_dir(req) == READ)
+		cmd = DASD_ECKD_CCW_READ_TRACK_DATA;
+	else if (rq_data_dir(req) == WRITE)
+		cmd = DASD_ECKD_CCW_WRITE_TRACK_DATA;
+	else
+		return ERR_PTR(-EINVAL);
+
+	/* Track based I/O needs IDAWs for each page, and not just for
+	 * 64 bit addresses. We need additional idals for pages
+	 * that get filled from two tracks, so we use the number
+	 * of records as upper limit.
+	 */
+	cidaw = last_rec - first_rec + 1;
+	trkcount = last_trk - first_trk + 1;
+
+	/* 1x prefix + one read/write ccw per track */
+	cplength = 1 + trkcount;
+
+	datasize = sizeof(struct PFX_eckd_data) + cidaw * sizeof(unsigned long);
+
+	/* Allocate the ccw request. */
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
+				   startdev, blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+	ccw = cqr->cpaddr;
+	/* transfer length factor: how many bytes to read from the last track */
+	if (first_trk == last_trk)
+		tlf = last_offs - first_offs + 1;
+	else
+		tlf = last_offs + 1;
+	tlf *= blksize;
+
+	if (prefix_LRE(ccw++, cqr->data, first_trk,
+		       last_trk, cmd, basedev, startdev,
+		       1 /* format */, first_offs + 1,
+		       trkcount, blksize,
+		       tlf) == -EAGAIN) {
+		/* Clock not in sync and XRC is enabled.
+		 * Try again later.
+		 */
+		dasd_sfree_request(cqr, startdev);
+		return ERR_PTR(-EAGAIN);
+	}
+
+	/*
+	 * The translation of request into ccw programs must meet the
+	 * following conditions:
+	 * - all idaws but the first and the last must address full pages
+	 *   (or 2K blocks on 31-bit)
+	 * - the scope of a ccw and it's idal ends with the track boundaries
+	 */
+	idaws = (unsigned long *) (cqr->data + sizeof(struct PFX_eckd_data));
+	recid = first_rec;
+	new_track = 1;
+	end_idaw = 0;
+	len_to_track_end = 0;
+	idaw_dst = NULL;
+	idaw_len = 0;
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		seg_len = bv.bv_len;
+		while (seg_len) {
+			if (new_track) {
+				trkid = recid;
+				recoffs = sector_div(trkid, blk_per_trk);
+				count_to_trk_end = blk_per_trk - recoffs;
+				count = min((last_rec - recid + 1),
+					    (sector_t)count_to_trk_end);
+				len_to_track_end = count * blksize;
+				ccw[-1].flags |= CCW_FLAG_CC;
+				ccw->cmd_code = cmd;
+				ccw->count = len_to_track_end;
+				ccw->cda = (__u32)(addr_t)idaws;
+				ccw->flags = CCW_FLAG_IDA;
+				ccw++;
+				recid += count;
+				new_track = 0;
+				/* first idaw for a ccw may start anywhere */
+				if (!idaw_dst)
+					idaw_dst = dst;
+			}
+			/* If we start a new idaw, we must make sure that it
+			 * starts on an IDA_BLOCK_SIZE boundary.
+			 * If we continue an idaw, we must make sure that the
+			 * current segment begins where the so far accumulated
+			 * idaw ends
+			 */
+			if (!idaw_dst) {
+				if (__pa(dst) & (IDA_BLOCK_SIZE-1)) {
+					dasd_sfree_request(cqr, startdev);
+					return ERR_PTR(-ERANGE);
+				} else
+					idaw_dst = dst;
+			}
+			if ((idaw_dst + idaw_len) != dst) {
+				dasd_sfree_request(cqr, startdev);
+				return ERR_PTR(-ERANGE);
+			}
+			part_len = min(seg_len, len_to_track_end);
+			seg_len -= part_len;
+			dst += part_len;
+			idaw_len += part_len;
+			len_to_track_end -= part_len;
+			/* collected memory area ends on an IDA_BLOCK border,
+			 * -> create an idaw
+			 * idal_create_words will handle cases where idaw_len
+			 * is larger then IDA_BLOCK_SIZE
+			 */
+			if (!(__pa(idaw_dst + idaw_len) & (IDA_BLOCK_SIZE-1)))
+				end_idaw = 1;
+			/* We also need to end the idaw at track end */
+			if (!len_to_track_end) {
+				new_track = 1;
+				end_idaw = 1;
+			}
+			if (end_idaw) {
+				idaws = idal_create_words(idaws, idaw_dst,
+							  idaw_len);
+				idaw_dst = NULL;
+				idaw_len = 0;
+				end_idaw = 0;
+			}
+		}
+	}
+
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->block = block;
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
+	cqr->lpm = dasd_path_get_ppm(startdev);
+	cqr->retries = startdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+static int prepare_itcw(struct itcw *itcw,
+			unsigned int trk, unsigned int totrk, int cmd,
+			struct dasd_device *basedev,
+			struct dasd_device *startdev,
+			unsigned int rec_on_trk, int count,
+			unsigned int blksize,
+			unsigned int total_data_size,
+			unsigned int tlf,
+			unsigned int blk_per_trk)
+{
+	struct PFX_eckd_data pfxdata;
+	struct dasd_eckd_private *basepriv, *startpriv;
+	struct DE_eckd_data *dedata;
+	struct LRE_eckd_data *lredata;
+	struct dcw *dcw;
+
+	u32 begcyl, endcyl;
+	u16 heads, beghead, endhead;
+	u8 pfx_cmd;
+
+	int rc = 0;
+	int sector = 0;
+	int dn, d;
+
+
+	/* setup prefix data */
+	basepriv = basedev->private;
+	startpriv = startdev->private;
+	dedata = &pfxdata.define_extent;
+	lredata = &pfxdata.locate_record;
+
+	memset(&pfxdata, 0, sizeof(pfxdata));
+	pfxdata.format = 1; /* PFX with LRE */
+	pfxdata.base_address = basepriv->ned->unit_addr;
+	pfxdata.base_lss = basepriv->ned->ID;
+	pfxdata.validity.define_extent = 1;
+
+	/* private uid is kept up to date, conf_data may be outdated */
+	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
+		pfxdata.validity.verify_base = 1;
+
+	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
+		pfxdata.validity.verify_base = 1;
+		pfxdata.validity.hyper_pav = 1;
+	}
+
+	switch (cmd) {
+	case DASD_ECKD_CCW_READ_TRACK_DATA:
+		dedata->mask.perm = 0x1;
+		dedata->attributes.operation = basepriv->attrib.operation;
+		dedata->blk_size = blksize;
+		dedata->ga_extended |= 0x42;
+		lredata->operation.orientation = 0x0;
+		lredata->operation.operation = 0x0C;
+		lredata->auxiliary.check_bytes = 0x01;
+		pfx_cmd = DASD_ECKD_CCW_PFX_READ;
+		break;
+	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
+		dedata->mask.perm = 0x02;
+		dedata->attributes.operation = basepriv->attrib.operation;
+		dedata->blk_size = blksize;
+		rc = set_timestamp(NULL, dedata, basedev);
+		dedata->ga_extended |= 0x42;
+		lredata->operation.orientation = 0x0;
+		lredata->operation.operation = 0x3F;
+		lredata->extended_operation = 0x23;
+		lredata->auxiliary.check_bytes = 0x2;
+		/*
+		 * If XRC is supported the System Time Stamp is set. The
+		 * validity of the time stamp must be reflected in the prefix
+		 * data as well.
+		 */
+		if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
+			pfxdata.validity.time_stamp = 1; /* 'Time Stamp Valid' */
+		pfx_cmd = DASD_ECKD_CCW_PFX;
+		break;
+	case DASD_ECKD_CCW_READ_COUNT_MT:
+		dedata->mask.perm = 0x1;
+		dedata->attributes.operation = DASD_BYPASS_CACHE;
+		dedata->ga_extended |= 0x42;
+		dedata->blk_size = blksize;
+		lredata->operation.orientation = 0x2;
+		lredata->operation.operation = 0x16;
+		lredata->auxiliary.check_bytes = 0x01;
+		pfx_cmd = DASD_ECKD_CCW_PFX_READ;
+		break;
+	default:
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "prepare itcw, unknown opcode 0x%x", cmd);
+		BUG();
+		break;
+	}
+	if (rc)
+		return rc;
+
+	dedata->attributes.mode = 0x3;	/* ECKD */
+
+	heads = basepriv->rdc_data.trk_per_cyl;
+	begcyl = trk / heads;
+	beghead = trk % heads;
+	endcyl = totrk / heads;
+	endhead = totrk % heads;
+
+	/* check for sequential prestage - enhance cylinder range */
+	if (dedata->attributes.operation == DASD_SEQ_PRESTAGE ||
+	    dedata->attributes.operation == DASD_SEQ_ACCESS) {
+
+		if (endcyl + basepriv->attrib.nr_cyl < basepriv->real_cyl)
+			endcyl += basepriv->attrib.nr_cyl;
+		else
+			endcyl = (basepriv->real_cyl - 1);
+	}
+
+	set_ch_t(&dedata->beg_ext, begcyl, beghead);
+	set_ch_t(&dedata->end_ext, endcyl, endhead);
+
+	dedata->ep_format = 0x20; /* records per track is valid */
+	dedata->ep_rec_per_track = blk_per_trk;
+
+	if (rec_on_trk) {
+		switch (basepriv->rdc_data.dev_type) {
+		case 0x3390:
+			dn = ceil_quot(blksize + 6, 232);
+			d = 9 + ceil_quot(blksize + 6 * (dn + 1), 34);
+			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
+			break;
+		case 0x3380:
+			d = 7 + ceil_quot(blksize + 12, 32);
+			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
+			break;
+		}
+	}
+
+	if (cmd == DASD_ECKD_CCW_READ_COUNT_MT) {
+		lredata->auxiliary.length_valid = 0;
+		lredata->auxiliary.length_scope = 0;
+		lredata->sector = 0xff;
+	} else {
+		lredata->auxiliary.length_valid = 1;
+		lredata->auxiliary.length_scope = 1;
+		lredata->sector = sector;
+	}
+	lredata->auxiliary.imbedded_ccw_valid = 1;
+	lredata->length = tlf;
+	lredata->imbedded_ccw = cmd;
+	lredata->count = count;
+	set_ch_t(&lredata->seek_addr, begcyl, beghead);
+	lredata->search_arg.cyl = lredata->seek_addr.cyl;
+	lredata->search_arg.head = lredata->seek_addr.head;
+	lredata->search_arg.record = rec_on_trk;
+
+	dcw = itcw_add_dcw(itcw, pfx_cmd, 0,
+		     &pfxdata, sizeof(pfxdata), total_data_size);
+	return PTR_ERR_OR_ZERO(dcw);
+}
+
+static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
+					       struct dasd_device *startdev,
+					       struct dasd_block *block,
+					       struct request *req,
+					       sector_t first_rec,
+					       sector_t last_rec,
+					       sector_t first_trk,
+					       sector_t last_trk,
+					       unsigned int first_offs,
+					       unsigned int last_offs,
+					       unsigned int blk_per_trk,
+					       unsigned int blksize)
+{
+	struct dasd_ccw_req *cqr;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst;
+	unsigned int trkcount, ctidaw;
+	unsigned char cmd;
+	struct dasd_device *basedev;
+	unsigned int tlf;
+	struct itcw *itcw;
+	struct tidaw *last_tidaw = NULL;
+	int itcw_op;
+	size_t itcw_size;
+	u8 tidaw_flags;
+	unsigned int seg_len, part_len, len_to_track_end;
+	unsigned char new_track;
+	sector_t recid, trkid;
+	unsigned int offs;
+	unsigned int count, count_to_trk_end;
+	int ret;
+
+	basedev = block->base;
+	if (rq_data_dir(req) == READ) {
+		cmd = DASD_ECKD_CCW_READ_TRACK_DATA;
+		itcw_op = ITCW_OP_READ;
+	} else if (rq_data_dir(req) == WRITE) {
+		cmd = DASD_ECKD_CCW_WRITE_TRACK_DATA;
+		itcw_op = ITCW_OP_WRITE;
+	} else
+		return ERR_PTR(-EINVAL);
+
+	/* trackbased I/O needs address all memory via TIDAWs,
+	 * not just for 64 bit addresses. This allows us to map
+	 * each segment directly to one tidaw.
+	 * In the case of write requests, additional tidaws may
+	 * be needed when a segment crosses a track boundary.
+	 */
+	trkcount = last_trk - first_trk + 1;
+	ctidaw = 0;
+	rq_for_each_segment(bv, req, iter) {
+		++ctidaw;
+	}
+	if (rq_data_dir(req) == WRITE)
+		ctidaw += (last_trk - first_trk);
+
+	/* Allocate the ccw request. */
+	itcw_size = itcw_calc_size(0, ctidaw, 0);
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
+				   blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+
+	/* transfer length factor: how many bytes to read from the last track */
+	if (first_trk == last_trk)
+		tlf = last_offs - first_offs + 1;
+	else
+		tlf = last_offs + 1;
+	tlf *= blksize;
+
+	itcw = itcw_init(cqr->data, itcw_size, itcw_op, 0, ctidaw, 0);
+	if (IS_ERR(itcw)) {
+		ret = -EINVAL;
+		goto out_error;
+	}
+	cqr->cpaddr = itcw_get_tcw(itcw);
+	if (prepare_itcw(itcw, first_trk, last_trk,
+			 cmd, basedev, startdev,
+			 first_offs + 1,
+			 trkcount, blksize,
+			 (last_rec - first_rec + 1) * blksize,
+			 tlf, blk_per_trk) == -EAGAIN) {
+		/* Clock not in sync and XRC is enabled.
+		 * Try again later.
+		 */
+		ret = -EAGAIN;
+		goto out_error;
+	}
+	len_to_track_end = 0;
+	/*
+	 * A tidaw can address 4k of memory, but must not cross page boundaries
+	 * We can let the block layer handle this by setting
+	 * blk_queue_segment_boundary to page boundaries and
+	 * blk_max_segment_size to page size when setting up the request queue.
+	 * For write requests, a TIDAW must not cross track boundaries, because
+	 * we have to set the CBC flag on the last tidaw for each track.
+	 */
+	if (rq_data_dir(req) == WRITE) {
+		new_track = 1;
+		recid = first_rec;
+		rq_for_each_segment(bv, req, iter) {
+			dst = page_address(bv.bv_page) + bv.bv_offset;
+			seg_len = bv.bv_len;
+			while (seg_len) {
+				if (new_track) {
+					trkid = recid;
+					offs = sector_div(trkid, blk_per_trk);
+					count_to_trk_end = blk_per_trk - offs;
+					count = min((last_rec - recid + 1),
+						    (sector_t)count_to_trk_end);
+					len_to_track_end = count * blksize;
+					recid += count;
+					new_track = 0;
+				}
+				part_len = min(seg_len, len_to_track_end);
+				seg_len -= part_len;
+				len_to_track_end -= part_len;
+				/* We need to end the tidaw at track end */
+				if (!len_to_track_end) {
+					new_track = 1;
+					tidaw_flags = TIDAW_FLAGS_INSERT_CBC;
+				} else
+					tidaw_flags = 0;
+				last_tidaw = itcw_add_tidaw(itcw, tidaw_flags,
+							    dst, part_len);
+				if (IS_ERR(last_tidaw)) {
+					ret = -EINVAL;
+					goto out_error;
+				}
+				dst += part_len;
+			}
+		}
+	} else {
+		rq_for_each_segment(bv, req, iter) {
+			dst = page_address(bv.bv_page) + bv.bv_offset;
+			last_tidaw = itcw_add_tidaw(itcw, 0x00,
+						    dst, bv.bv_len);
+			if (IS_ERR(last_tidaw)) {
+				ret = -EINVAL;
+				goto out_error;
+			}
+		}
+	}
+	last_tidaw->flags |= TIDAW_FLAGS_LAST;
+	last_tidaw->flags &= ~TIDAW_FLAGS_INSERT_CBC;
+	itcw_finalize(itcw);
+
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->cpmode = 1;
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->block = block;
+	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
+	cqr->lpm = dasd_path_get_ppm(startdev);
+	cqr->retries = startdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+out_error:
+	dasd_sfree_request(cqr, startdev);
+	return ERR_PTR(ret);
+}
+
+static struct dasd_ccw_req *dasd_eckd_build_cp(struct dasd_device *startdev,
+					       struct dasd_block *block,
+					       struct request *req)
+{
+	int cmdrtd, cmdwtd;
+	int use_prefix;
+	int fcx_multitrack;
+	struct dasd_eckd_private *private;
+	struct dasd_device *basedev;
+	sector_t first_rec, last_rec;
+	sector_t first_trk, last_trk;
+	unsigned int first_offs, last_offs;
+	unsigned int blk_per_trk, blksize;
+	int cdlspecial;
+	unsigned int data_size;
+	struct dasd_ccw_req *cqr;
+
+	basedev = block->base;
+	private = basedev->private;
+
+	/* Calculate number of blocks/records per track. */
+	blksize = block->bp_block;
+	blk_per_trk = recs_per_track(&private->rdc_data, 0, blksize);
+	if (blk_per_trk == 0)
+		return ERR_PTR(-EINVAL);
+	/* Calculate record id of first and last block. */
+	first_rec = first_trk = blk_rq_pos(req) >> block->s2b_shift;
+	first_offs = sector_div(first_trk, blk_per_trk);
+	last_rec = last_trk =
+		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
+	last_offs = sector_div(last_trk, blk_per_trk);
+	cdlspecial = (private->uses_cdl && first_rec < 2*blk_per_trk);
+
+	fcx_multitrack = private->features.feature[40] & 0x20;
+	data_size = blk_rq_bytes(req);
+	if (data_size % blksize)
+		return ERR_PTR(-EINVAL);
+	/* tpm write request add CBC data on each track boundary */
+	if (rq_data_dir(req) == WRITE)
+		data_size += (last_trk - first_trk) * 4;
+
+	/* is read track data and write track data in command mode supported? */
+	cmdrtd = private->features.feature[9] & 0x20;
+	cmdwtd = private->features.feature[12] & 0x40;
+	use_prefix = private->features.feature[8] & 0x01;
+
+	cqr = NULL;
+	if (cdlspecial || dasd_page_cache) {
+		/* do nothing, just fall through to the cmd mode single case */
+	} else if ((data_size <= private->fcx_max_data)
+		   && (fcx_multitrack || (first_trk == last_trk))) {
+		cqr = dasd_eckd_build_cp_tpm_track(startdev, block, req,
+						    first_rec, last_rec,
+						    first_trk, last_trk,
+						    first_offs, last_offs,
+						    blk_per_trk, blksize);
+		if (IS_ERR(cqr) && (PTR_ERR(cqr) != -EAGAIN) &&
+		    (PTR_ERR(cqr) != -ENOMEM))
+			cqr = NULL;
+	} else if (use_prefix &&
+		   (((rq_data_dir(req) == READ) && cmdrtd) ||
+		    ((rq_data_dir(req) == WRITE) && cmdwtd))) {
+		cqr = dasd_eckd_build_cp_cmd_track(startdev, block, req,
+						   first_rec, last_rec,
+						   first_trk, last_trk,
+						   first_offs, last_offs,
+						   blk_per_trk, blksize);
+		if (IS_ERR(cqr) && (PTR_ERR(cqr) != -EAGAIN) &&
+		    (PTR_ERR(cqr) != -ENOMEM))
+			cqr = NULL;
+	}
+	if (!cqr)
+		cqr = dasd_eckd_build_cp_cmd_single(startdev, block, req,
+						    first_rec, last_rec,
+						    first_trk, last_trk,
+						    first_offs, last_offs,
+						    blk_per_trk, blksize);
+	return cqr;
+}
+
+static struct dasd_ccw_req *dasd_eckd_build_cp_raw(struct dasd_device *startdev,
+						   struct dasd_block *block,
+						   struct request *req)
+{
+	sector_t start_padding_sectors, end_sector_offset, end_padding_sectors;
+	unsigned int seg_len, len_to_track_end;
+	unsigned int cidaw, cplength, datasize;
+	sector_t first_trk, last_trk, sectors;
+	struct dasd_eckd_private *base_priv;
+	struct dasd_device *basedev;
+	struct req_iterator iter;
+	struct dasd_ccw_req *cqr;
+	unsigned int first_offs;
+	unsigned int trkcount;
+	unsigned long *idaws;
+	unsigned int size;
+	unsigned char cmd;
+	struct bio_vec bv;
+	struct ccw1 *ccw;
+	int use_prefix;
+	void *data;
+	char *dst;
+
+	/*
+	 * raw track access needs to be mutiple of 64k and on 64k boundary
+	 * For read requests we can fix an incorrect alignment by padding
+	 * the request with dummy pages.
+	 */
+	start_padding_sectors = blk_rq_pos(req) % DASD_RAW_SECTORS_PER_TRACK;
+	end_sector_offset = (blk_rq_pos(req) + blk_rq_sectors(req)) %
+		DASD_RAW_SECTORS_PER_TRACK;
+	end_padding_sectors = (DASD_RAW_SECTORS_PER_TRACK - end_sector_offset) %
+		DASD_RAW_SECTORS_PER_TRACK;
+	basedev = block->base;
+	if ((start_padding_sectors || end_padding_sectors) &&
+	    (rq_data_dir(req) == WRITE)) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "raw write not track aligned (%lu,%lu) req %p",
+			      start_padding_sectors, end_padding_sectors, req);
+		return ERR_PTR(-EINVAL);
+	}
+
+	first_trk = blk_rq_pos(req) / DASD_RAW_SECTORS_PER_TRACK;
+	last_trk = (blk_rq_pos(req) + blk_rq_sectors(req) - 1) /
+		DASD_RAW_SECTORS_PER_TRACK;
+	trkcount = last_trk - first_trk + 1;
+	first_offs = 0;
+
+	if (rq_data_dir(req) == READ)
+		cmd = DASD_ECKD_CCW_READ_TRACK;
+	else if (rq_data_dir(req) == WRITE)
+		cmd = DASD_ECKD_CCW_WRITE_FULL_TRACK;
+	else
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * Raw track based I/O needs IDAWs for each page,
+	 * and not just for 64 bit addresses.
+	 */
+	cidaw = trkcount * DASD_RAW_BLOCK_PER_TRACK;
+
+	/*
+	 * struct PFX_eckd_data and struct LRE_eckd_data can have up to 2 bytes
+	 * of extended parameter. This is needed for write full track.
+	 */
+	base_priv = basedev->private;
+	use_prefix = base_priv->features.feature[8] & 0x01;
+	if (use_prefix) {
+		cplength = 1 + trkcount;
+		size = sizeof(struct PFX_eckd_data) + 2;
+	} else {
+		cplength = 2 + trkcount;
+		size = sizeof(struct DE_eckd_data) +
+			sizeof(struct LRE_eckd_data) + 2;
+	}
+	size = ALIGN(size, 8);
+
+	datasize = size + cidaw * sizeof(unsigned long);
+
+	/* Allocate the ccw request. */
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
+				   datasize, startdev, blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+
+	ccw = cqr->cpaddr;
+	data = cqr->data;
+
+	if (use_prefix) {
+		prefix_LRE(ccw++, data, first_trk, last_trk, cmd, basedev,
+			   startdev, 1, first_offs + 1, trkcount, 0, 0);
+	} else {
+		define_extent(ccw++, data, first_trk, last_trk, cmd, basedev, 0);
+		ccw[-1].flags |= CCW_FLAG_CC;
+
+		data += sizeof(struct DE_eckd_data);
+		locate_record_ext(ccw++, data, first_trk, first_offs + 1,
+				  trkcount, cmd, basedev, 0, 0);
+	}
+
+	idaws = (unsigned long *)(cqr->data + size);
+	len_to_track_end = 0;
+	if (start_padding_sectors) {
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw->cmd_code = cmd;
+		/* maximum 3390 track size */
+		ccw->count = 57326;
+		/* 64k map to one track */
+		len_to_track_end = 65536 - start_padding_sectors * 512;
+		ccw->cda = (__u32)(addr_t)idaws;
+		ccw->flags |= CCW_FLAG_IDA;
+		ccw->flags |= CCW_FLAG_SLI;
+		ccw++;
+		for (sectors = 0; sectors < start_padding_sectors; sectors += 8)
+			idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
+	}
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		seg_len = bv.bv_len;
+		if (cmd == DASD_ECKD_CCW_READ_TRACK)
+			memset(dst, 0, seg_len);
+		if (!len_to_track_end) {
+			ccw[-1].flags |= CCW_FLAG_CC;
+			ccw->cmd_code = cmd;
+			/* maximum 3390 track size */
+			ccw->count = 57326;
+			/* 64k map to one track */
+			len_to_track_end = 65536;
+			ccw->cda = (__u32)(addr_t)idaws;
+			ccw->flags |= CCW_FLAG_IDA;
+			ccw->flags |= CCW_FLAG_SLI;
+			ccw++;
+		}
+		len_to_track_end -= seg_len;
+		idaws = idal_create_words(idaws, dst, seg_len);
+	}
+	for (sectors = 0; sectors < end_padding_sectors; sectors += 8)
+		idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->startdev = startdev;
+	cqr->memdev = startdev;
+	cqr->block = block;
+	cqr->expires = startdev->default_expires * HZ;
+	cqr->lpm = dasd_path_get_ppm(startdev);
+	cqr->retries = startdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	return cqr;
+}
+
+
+static int
+dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req)
+{
+	struct dasd_eckd_private *private;
+	struct ccw1 *ccw;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst, *cda;
+	unsigned int blksize, blk_per_trk, off;
+	sector_t recid;
+	int status;
+
+	if (!dasd_page_cache)
+		goto out;
+	private = cqr->block->base->private;
+	blksize = cqr->block->bp_block;
+	blk_per_trk = recs_per_track(&private->rdc_data, 0, blksize);
+	recid = blk_rq_pos(req) >> cqr->block->s2b_shift;
+	ccw = cqr->cpaddr;
+	/* Skip over define extent & locate record. */
+	ccw++;
+	if (private->uses_cdl == 0 || recid > 2*blk_per_trk)
+		ccw++;
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
+			/* Skip locate record. */
+			if (private->uses_cdl && recid <= 2*blk_per_trk)
+				ccw++;
+			if (dst) {
+				if (ccw->flags & CCW_FLAG_IDA)
+					cda = *((char **)((addr_t) ccw->cda));
+				else
+					cda = (char *)((addr_t) ccw->cda);
+				if (dst != cda) {
+					if (rq_data_dir(req) == READ)
+						memcpy(dst, cda, bv.bv_len);
+					kmem_cache_free(dasd_page_cache,
+					    (void *)((addr_t)cda & PAGE_MASK));
+				}
+				dst = NULL;
+			}
+			ccw++;
+			recid++;
+		}
+	}
+out:
+	status = cqr->status == DASD_CQR_DONE;
+	dasd_sfree_request(cqr, cqr->memdev);
+	return status;
+}
+
+/*
+ * Modify ccw/tcw in cqr so it can be started on a base device.
+ *
+ * Note that this is not enough to restart the cqr!
+ * Either reset cqr->startdev as well (summary unit check handling)
+ * or restart via separate cqr (as in ERP handling).
+ */
+void dasd_eckd_reset_ccw_to_base_io(struct dasd_ccw_req *cqr)
+{
+	struct ccw1 *ccw;
+	struct PFX_eckd_data *pfxdata;
+	struct tcw *tcw;
+	struct tccb *tccb;
+	struct dcw *dcw;
+
+	if (cqr->cpmode == 1) {
+		tcw = cqr->cpaddr;
+		tccb = tcw_get_tccb(tcw);
+		dcw = (struct dcw *)&tccb->tca[0];
+		pfxdata = (struct PFX_eckd_data *)&dcw->cd[0];
+		pfxdata->validity.verify_base = 0;
+		pfxdata->validity.hyper_pav = 0;
+	} else {
+		ccw = cqr->cpaddr;
+		pfxdata = cqr->data;
+		if (ccw->cmd_code == DASD_ECKD_CCW_PFX) {
+			pfxdata->validity.verify_base = 0;
+			pfxdata->validity.hyper_pav = 0;
+		}
+	}
+}
+
+#define DASD_ECKD_CHANQ_MAX_SIZE 4
+
+static struct dasd_ccw_req *dasd_eckd_build_alias_cp(struct dasd_device *base,
+						     struct dasd_block *block,
+						     struct request *req)
+{
+	struct dasd_eckd_private *private;
+	struct dasd_device *startdev;
+	unsigned long flags;
+	struct dasd_ccw_req *cqr;
+
+	startdev = dasd_alias_get_start_dev(base);
+	if (!startdev)
+		startdev = base;
+	private = startdev->private;
+	if (private->count >= DASD_ECKD_CHANQ_MAX_SIZE)
+		return ERR_PTR(-EBUSY);
+
+	spin_lock_irqsave(get_ccwdev_lock(startdev->cdev), flags);
+	private->count++;
+	if ((base->features & DASD_FEATURE_USERAW))
+		cqr = dasd_eckd_build_cp_raw(startdev, block, req);
+	else
+		cqr = dasd_eckd_build_cp(startdev, block, req);
+	if (IS_ERR(cqr))
+		private->count--;
+	spin_unlock_irqrestore(get_ccwdev_lock(startdev->cdev), flags);
+	return cqr;
+}
+
+static int dasd_eckd_free_alias_cp(struct dasd_ccw_req *cqr,
+				   struct request *req)
+{
+	struct dasd_eckd_private *private;
+	unsigned long flags;
+
+	spin_lock_irqsave(get_ccwdev_lock(cqr->memdev->cdev), flags);
+	private = cqr->memdev->private;
+	private->count--;
+	spin_unlock_irqrestore(get_ccwdev_lock(cqr->memdev->cdev), flags);
+	return dasd_eckd_free_cp(cqr, req);
+}
+
+static int
+dasd_eckd_fill_info(struct dasd_device * device,
+		    struct dasd_information2_t * info)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	info->label_block = 2;
+	info->FBA_layout = private->uses_cdl ? 0 : 1;
+	info->format = private->uses_cdl ? DASD_FORMAT_CDL : DASD_FORMAT_LDL;
+	info->characteristics_size = sizeof(private->rdc_data);
+	memcpy(info->characteristics, &private->rdc_data,
+	       sizeof(private->rdc_data));
+	info->confdata_size = min((unsigned long)private->conf_len,
+				  sizeof(info->configuration_data));
+	memcpy(info->configuration_data, private->conf_data,
+	       info->confdata_size);
+	return 0;
+}
+
+/*
+ * SECTION: ioctl functions for eckd devices.
+ */
+
+/*
+ * Release device ioctl.
+ * Buils a channel programm to releases a prior reserved
+ * (see dasd_eckd_reserve) device.
+ */
+static int
+dasd_eckd_release(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+	struct ccw1 *ccw;
+	int useglobal;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	useglobal = 0;
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
+	if (IS_ERR(cqr)) {
+		mutex_lock(&dasd_reserve_mutex);
+		useglobal = 1;
+		cqr = &dasd_reserve_req->cqr;
+		memset(cqr, 0, sizeof(*cqr));
+		memset(&dasd_reserve_req->ccw, 0,
+		       sizeof(dasd_reserve_req->ccw));
+		cqr->cpaddr = &dasd_reserve_req->ccw;
+		cqr->data = &dasd_reserve_req->data;
+		cqr->magic = DASD_ECKD_MAGIC;
+	}
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_RELEASE;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = 32;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
+	cqr->expires = 2 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	if (!rc)
+		clear_bit(DASD_FLAG_IS_RESERVED, &device->flags);
+
+	if (useglobal)
+		mutex_unlock(&dasd_reserve_mutex);
+	else
+		dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * Reserve device ioctl.
+ * Options are set to 'synchronous wait for interrupt' and
+ * 'timeout the request'. This leads to a terminate IO if
+ * the interrupt is outstanding for a certain time.
+ */
+static int
+dasd_eckd_reserve(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+	struct ccw1 *ccw;
+	int useglobal;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	useglobal = 0;
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
+	if (IS_ERR(cqr)) {
+		mutex_lock(&dasd_reserve_mutex);
+		useglobal = 1;
+		cqr = &dasd_reserve_req->cqr;
+		memset(cqr, 0, sizeof(*cqr));
+		memset(&dasd_reserve_req->ccw, 0,
+		       sizeof(dasd_reserve_req->ccw));
+		cqr->cpaddr = &dasd_reserve_req->ccw;
+		cqr->data = &dasd_reserve_req->data;
+		cqr->magic = DASD_ECKD_MAGIC;
+	}
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_RESERVE;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = 32;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
+	cqr->expires = 2 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	if (!rc)
+		set_bit(DASD_FLAG_IS_RESERVED, &device->flags);
+
+	if (useglobal)
+		mutex_unlock(&dasd_reserve_mutex);
+	else
+		dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * Steal lock ioctl - unconditional reserve device.
+ * Buils a channel programm to break a device's reservation.
+ * (unconditional reserve)
+ */
+static int
+dasd_eckd_steal_lock(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+	struct ccw1 *ccw;
+	int useglobal;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	useglobal = 0;
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
+	if (IS_ERR(cqr)) {
+		mutex_lock(&dasd_reserve_mutex);
+		useglobal = 1;
+		cqr = &dasd_reserve_req->cqr;
+		memset(cqr, 0, sizeof(*cqr));
+		memset(&dasd_reserve_req->ccw, 0,
+		       sizeof(dasd_reserve_req->ccw));
+		cqr->cpaddr = &dasd_reserve_req->ccw;
+		cqr->data = &dasd_reserve_req->data;
+		cqr->magic = DASD_ECKD_MAGIC;
+	}
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_SLCK;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = 32;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
+	cqr->expires = 2 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	if (!rc)
+		set_bit(DASD_FLAG_IS_RESERVED, &device->flags);
+
+	if (useglobal)
+		mutex_unlock(&dasd_reserve_mutex);
+	else
+		dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * SNID - Sense Path Group ID
+ * This ioctl may be used in situations where I/O is stalled due to
+ * a reserve, so if the normal dasd_smalloc_request fails, we use the
+ * preallocated dasd_reserve_req.
+ */
+static int dasd_eckd_snid(struct dasd_device *device,
+			  void __user *argp)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+	struct ccw1 *ccw;
+	int useglobal;
+	struct dasd_snid_ioctl_data usrparm;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
+		return -EFAULT;
+
+	useglobal = 0;
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1,
+				   sizeof(struct dasd_snid_data), device,
+				   NULL);
+	if (IS_ERR(cqr)) {
+		mutex_lock(&dasd_reserve_mutex);
+		useglobal = 1;
+		cqr = &dasd_reserve_req->cqr;
+		memset(cqr, 0, sizeof(*cqr));
+		memset(&dasd_reserve_req->ccw, 0,
+		       sizeof(dasd_reserve_req->ccw));
+		cqr->cpaddr = &dasd_reserve_req->ccw;
+		cqr->data = &dasd_reserve_req->data;
+		cqr->magic = DASD_ECKD_MAGIC;
+	}
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_SNID;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = 12;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
+	cqr->retries = 5;
+	cqr->expires = 10 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	cqr->lpm = usrparm.path_mask;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	/* verify that I/O processing didn't modify the path mask */
+	if (!rc && usrparm.path_mask && (cqr->lpm != usrparm.path_mask))
+		rc = -EIO;
+	if (!rc) {
+		usrparm.data = *((struct dasd_snid_data *)cqr->data);
+		if (copy_to_user(argp, &usrparm, sizeof(usrparm)))
+			rc = -EFAULT;
+	}
+
+	if (useglobal)
+		mutex_unlock(&dasd_reserve_mutex);
+	else
+		dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * Read performance statistics
+ */
+static int
+dasd_eckd_performance(struct dasd_device *device, void __user *argp)
+{
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_rssd_perf_stats_t *stats;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */  + 1 /* RSSD */,
+				   (sizeof(struct dasd_psf_prssd_data) +
+				    sizeof(struct dasd_rssd_perf_stats_t)),
+				   device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "Could not allocate initialization request");
+		return PTR_ERR(cqr);
+	}
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->retries = 0;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->expires = 10 * HZ;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = 0x01;	/* Performance Statistics */
+	prssdp->varies[1] = 0x01;	/* Perf Statistics for the Subsystem */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->cda = (__u32)(addr_t) prssdp;
+
+	/* Read Subsystem Data - Performance Statistics */
+	stats = (struct dasd_rssd_perf_stats_t *) (prssdp + 1);
+	memset(stats, 0, sizeof(struct dasd_rssd_perf_stats_t));
+
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(struct dasd_rssd_perf_stats_t);
+	ccw->cda = (__u32)(addr_t) stats;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	rc = dasd_sleep_on(cqr);
+	if (rc == 0) {
+		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+		stats = (struct dasd_rssd_perf_stats_t *) (prssdp + 1);
+		if (copy_to_user(argp, stats,
+				 sizeof(struct dasd_rssd_perf_stats_t)))
+			rc = -EFAULT;
+	}
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * Get attributes (cache operations)
+ * Returnes the cache attributes used in Define Extend (DE).
+ */
+static int
+dasd_eckd_get_attrib(struct dasd_device *device, void __user *argp)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct attrib_data_t attrib = private->attrib;
+	int rc;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+	if (!argp)
+                return -EINVAL;
+
+	rc = 0;
+	if (copy_to_user(argp, (long *) &attrib,
+			 sizeof(struct attrib_data_t)))
+		rc = -EFAULT;
+
+	return rc;
+}
+
+/*
+ * Set attributes (cache operations)
+ * Stores the attributes for cache operation to be used in Define Extend (DE).
+ */
+static int
+dasd_eckd_set_attrib(struct dasd_device *device, void __user *argp)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct attrib_data_t attrib;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (!argp)
+		return -EINVAL;
+
+	if (copy_from_user(&attrib, argp, sizeof(struct attrib_data_t)))
+		return -EFAULT;
+	private->attrib = attrib;
+
+	dev_info(&device->cdev->dev,
+		 "The DASD cache mode was set to %x (%i cylinder prestage)\n",
+		 private->attrib.operation, private->attrib.nr_cyl);
+	return 0;
+}
+
+/*
+ * Issue syscall I/O to EMC Symmetrix array.
+ * CCWs are PSF and RSSD
+ */
+static int dasd_symm_io(struct dasd_device *device, void __user *argp)
+{
+	struct dasd_symmio_parms usrparm;
+	char *psf_data, *rssd_result;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	char psf0, psf1;
+	int rc;
+
+	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+		return -EACCES;
+	psf0 = psf1 = 0;
+
+	/* Copy parms from caller */
+	rc = -EFAULT;
+	if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
+		goto out;
+	if (is_compat_task()) {
+		/* Make sure pointers are sane even on 31 bit. */
+		rc = -EINVAL;
+		if ((usrparm.psf_data >> 32) != 0)
+			goto out;
+		if ((usrparm.rssd_result >> 32) != 0)
+			goto out;
+		usrparm.psf_data &= 0x7fffffffULL;
+		usrparm.rssd_result &= 0x7fffffffULL;
+	}
+	/* at least 2 bytes are accessed and should be allocated */
+	if (usrparm.psf_data_len < 2) {
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			      "Symmetrix ioctl invalid data length %d",
+			      usrparm.psf_data_len);
+		rc = -EINVAL;
+		goto out;
+	}
+	/* alloc I/O data area */
+	psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA);
+	rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA);
+	if (!psf_data || !rssd_result) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
+
+	/* get syscall header from user space */
+	rc = -EFAULT;
+	if (copy_from_user(psf_data,
+			   (void __user *)(unsigned long) usrparm.psf_data,
+			   usrparm.psf_data_len))
+		goto out_free;
+	psf0 = psf_data[0];
+	psf1 = psf_data[1];
+
+	/* setup CCWs for PSF + RSSD */
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2, 0, device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			"Could not allocate initialization request");
+		rc = PTR_ERR(cqr);
+		goto out_free;
+	}
+
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->retries = 3;
+	cqr->expires = 10 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	/* Build the ccws */
+	ccw = cqr->cpaddr;
+
+	/* PSF ccw */
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = usrparm.psf_data_len;
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->cda = (__u32)(addr_t) psf_data;
+
+	ccw++;
+
+	/* RSSD ccw  */
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = usrparm.rssd_result_len;
+	ccw->flags = CCW_FLAG_SLI ;
+	ccw->cda = (__u32)(addr_t) rssd_result;
+
+	rc = dasd_sleep_on(cqr);
+	if (rc)
+		goto out_sfree;
+
+	rc = -EFAULT;
+	if (copy_to_user((void __user *)(unsigned long) usrparm.rssd_result,
+			   rssd_result, usrparm.rssd_result_len))
+		goto out_sfree;
+	rc = 0;
+
+out_sfree:
+	dasd_sfree_request(cqr, cqr->memdev);
+out_free:
+	kfree(rssd_result);
+	kfree(psf_data);
+out:
+	DBF_DEV_EVENT(DBF_WARNING, device,
+		      "Symmetrix ioctl (0x%02x 0x%02x): rc=%d",
+		      (int) psf0, (int) psf1, rc);
+	return rc;
+}
+
+static int
+dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp)
+{
+	struct dasd_device *device = block->base;
+
+	switch (cmd) {
+	case BIODASDGATTR:
+		return dasd_eckd_get_attrib(device, argp);
+	case BIODASDSATTR:
+		return dasd_eckd_set_attrib(device, argp);
+	case BIODASDPSRD:
+		return dasd_eckd_performance(device, argp);
+	case BIODASDRLSE:
+		return dasd_eckd_release(device);
+	case BIODASDRSRV:
+		return dasd_eckd_reserve(device);
+	case BIODASDSLCK:
+		return dasd_eckd_steal_lock(device);
+	case BIODASDSNID:
+		return dasd_eckd_snid(device, argp);
+	case BIODASDSYMMIO:
+		return dasd_symm_io(device, argp);
+	default:
+		return -ENOTTY;
+	}
+}
+
+/*
+ * Dump the range of CCWs into 'page' buffer
+ * and return number of printed chars.
+ */
+static int
+dasd_eckd_dump_ccw_range(struct ccw1 *from, struct ccw1 *to, char *page)
+{
+	int len, count;
+	char *datap;
+
+	len = 0;
+	while (from <= to) {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " CCW %p: %08X %08X DAT:",
+			       from, ((int *) from)[0], ((int *) from)[1]);
+
+		/* get pointer to data (consider IDALs) */
+		if (from->flags & CCW_FLAG_IDA)
+			datap = (char *) *((addr_t *) (addr_t) from->cda);
+		else
+			datap = (char *) ((addr_t) from->cda);
+
+		/* dump data (max 32 bytes) */
+		for (count = 0; count < from->count && count < 32; count++) {
+			if (count % 8 == 0) len += sprintf(page + len, " ");
+			if (count % 4 == 0) len += sprintf(page + len, " ");
+			len += sprintf(page + len, "%02x", datap[count]);
+		}
+		len += sprintf(page + len, "\n");
+		from++;
+	}
+	return len;
+}
+
+static void
+dasd_eckd_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
+			 char *reason)
+{
+	u64 *sense;
+	u64 *stat;
+
+	sense = (u64 *) dasd_get_sense(irb);
+	stat = (u64 *) &irb->scsw;
+	if (sense) {
+		DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : "
+			      "%016llx %016llx %016llx %016llx",
+			      reason, *stat, *((u32 *) (stat + 1)),
+			      sense[0], sense[1], sense[2], sense[3]);
+	} else {
+		DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : %s",
+			      reason, *stat, *((u32 *) (stat + 1)),
+			      "NO VALID SENSE");
+	}
+}
+
+/*
+ * Print sense data and related channel program.
+ * Parts are printed because printk buffer is only 1024 bytes.
+ */
+static void dasd_eckd_dump_sense_ccw(struct dasd_device *device,
+				 struct dasd_ccw_req *req, struct irb *irb)
+{
+	char *page;
+	struct ccw1 *first, *last, *fail, *from, *to;
+	int len, sl, sct;
+
+	page = (char *) get_zeroed_page(GFP_ATOMIC);
+	if (page == NULL) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "No memory to dump sense data\n");
+		return;
+	}
+	/* dump the sense data */
+	len = sprintf(page, PRINTK_HEADER
+		      " I/O status report for device %s:\n",
+		      dev_name(&device->cdev->dev));
+	len += sprintf(page + len, PRINTK_HEADER
+		       " in req: %p CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X "
+		       "CS:%02X RC:%d\n",
+		       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
+		       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
+		       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
+		       req ? req->intrc : 0);
+	len += sprintf(page + len, PRINTK_HEADER
+		       " device %s: Failing CCW: %p\n",
+		       dev_name(&device->cdev->dev),
+		       (void *) (addr_t) irb->scsw.cmd.cpa);
+	if (irb->esw.esw0.erw.cons) {
+		for (sl = 0; sl < 4; sl++) {
+			len += sprintf(page + len, PRINTK_HEADER
+				       " Sense(hex) %2d-%2d:",
+				       (8 * sl), ((8 * sl) + 7));
+
+			for (sct = 0; sct < 8; sct++) {
+				len += sprintf(page + len, " %02x",
+					       irb->ecw[8 * sl + sct]);
+			}
+			len += sprintf(page + len, "\n");
+		}
+
+		if (irb->ecw[27] & DASD_SENSE_BIT_0) {
+			/* 24 Byte Sense Data */
+			sprintf(page + len, PRINTK_HEADER
+				" 24 Byte: %x MSG %x, "
+				"%s MSGb to SYSOP\n",
+				irb->ecw[7] >> 4, irb->ecw[7] & 0x0f,
+				irb->ecw[1] & 0x10 ? "" : "no");
+		} else {
+			/* 32 Byte Sense Data */
+			sprintf(page + len, PRINTK_HEADER
+				" 32 Byte: Format: %x "
+				"Exception class %x\n",
+				irb->ecw[6] & 0x0f, irb->ecw[22] >> 4);
+		}
+	} else {
+		sprintf(page + len, PRINTK_HEADER
+			" SORRY - NO VALID SENSE AVAILABLE\n");
+	}
+	printk(KERN_ERR "%s", page);
+
+	if (req) {
+		/* req == NULL for unsolicited interrupts */
+		/* dump the Channel Program (max 140 Bytes per line) */
+		/* Count CCW and print first CCWs (maximum 1024 % 140 = 7) */
+		first = req->cpaddr;
+		for (last = first; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
+		to = min(first + 6, last);
+		len = sprintf(page, PRINTK_HEADER
+			      " Related CP in req: %p\n", req);
+		dasd_eckd_dump_ccw_range(first, to, page + len);
+		printk(KERN_ERR "%s", page);
+
+		/* print failing CCW area (maximum 4) */
+		/* scsw->cda is either valid or zero  */
+		len = 0;
+		from = ++to;
+		fail = (struct ccw1 *)(addr_t)
+				irb->scsw.cmd.cpa; /* failing CCW */
+		if (from <  fail - 2) {
+			from = fail - 2;     /* there is a gap - print header */
+			len += sprintf(page, PRINTK_HEADER "......\n");
+		}
+		to = min(fail + 1, last);
+		len += dasd_eckd_dump_ccw_range(from, to, page + len);
+
+		/* print last CCWs (maximum 2) */
+		from = max(from, ++to);
+		if (from < last - 1) {
+			from = last - 1;     /* there is a gap - print header */
+			len += sprintf(page + len, PRINTK_HEADER "......\n");
+		}
+		len += dasd_eckd_dump_ccw_range(from, last, page + len);
+		if (len > 0)
+			printk(KERN_ERR "%s", page);
+	}
+	free_page((unsigned long) page);
+}
+
+
+/*
+ * Print sense data from a tcw.
+ */
+static void dasd_eckd_dump_sense_tcw(struct dasd_device *device,
+				 struct dasd_ccw_req *req, struct irb *irb)
+{
+	char *page;
+	int len, sl, sct, residual;
+	struct tsb *tsb;
+	u8 *sense, *rcq;
+
+	page = (char *) get_zeroed_page(GFP_ATOMIC);
+	if (page == NULL) {
+		DBF_DEV_EVENT(DBF_WARNING, device, " %s",
+			    "No memory to dump sense data");
+		return;
+	}
+	/* dump the sense data */
+	len = sprintf(page, PRINTK_HEADER
+		      " I/O status report for device %s:\n",
+		      dev_name(&device->cdev->dev));
+	len += sprintf(page + len, PRINTK_HEADER
+		       " in req: %p CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X "
+		       "CS:%02X fcxs:%02X schxs:%02X RC:%d\n",
+		       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
+		       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
+		       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
+		       irb->scsw.tm.fcxs,
+		       (irb->scsw.tm.ifob << 7) | irb->scsw.tm.sesq,
+		       req ? req->intrc : 0);
+	len += sprintf(page + len, PRINTK_HEADER
+		       " device %s: Failing TCW: %p\n",
+		       dev_name(&device->cdev->dev),
+		       (void *) (addr_t) irb->scsw.tm.tcw);
+
+	tsb = NULL;
+	sense = NULL;
+	if (irb->scsw.tm.tcw && (irb->scsw.tm.fcxs & 0x01))
+		tsb = tcw_get_tsb(
+			(struct tcw *)(unsigned long)irb->scsw.tm.tcw);
+
+	if (tsb) {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->length %d\n", tsb->length);
+		len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->flags %x\n", tsb->flags);
+		len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->dcw_offset %d\n", tsb->dcw_offset);
+		len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->count %d\n", tsb->count);
+		residual = tsb->count - 28;
+		len += sprintf(page + len, PRINTK_HEADER
+			       " residual %d\n", residual);
+
+		switch (tsb->flags & 0x07) {
+		case 1:	/* tsa_iostat */
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.iostat.dev_time %d\n",
+				       tsb->tsa.iostat.dev_time);
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.iostat.def_time %d\n",
+				       tsb->tsa.iostat.def_time);
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.iostat.queue_time %d\n",
+				       tsb->tsa.iostat.queue_time);
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.iostat.dev_busy_time %d\n",
+				       tsb->tsa.iostat.dev_busy_time);
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.iostat.dev_act_time %d\n",
+				       tsb->tsa.iostat.dev_act_time);
+			sense = tsb->tsa.iostat.sense;
+			break;
+		case 2: /* ts_ddpc */
+			len += sprintf(page + len, PRINTK_HEADER
+			       " tsb->tsa.ddpc.rc %d\n", tsb->tsa.ddpc.rc);
+			for (sl = 0; sl < 2; sl++) {
+				len += sprintf(page + len, PRINTK_HEADER
+					       " tsb->tsa.ddpc.rcq %2d-%2d: ",
+					       (8 * sl), ((8 * sl) + 7));
+				rcq = tsb->tsa.ddpc.rcq;
+				for (sct = 0; sct < 8; sct++) {
+					len += sprintf(page + len, " %02x",
+						       rcq[8 * sl + sct]);
+				}
+				len += sprintf(page + len, "\n");
+			}
+			sense = tsb->tsa.ddpc.sense;
+			break;
+		case 3: /* tsa_intrg */
+			len += sprintf(page + len, PRINTK_HEADER
+				      " tsb->tsa.intrg.: not supported yet\n");
+			break;
+		}
+
+		if (sense) {
+			for (sl = 0; sl < 4; sl++) {
+				len += sprintf(page + len, PRINTK_HEADER
+					       " Sense(hex) %2d-%2d:",
+					       (8 * sl), ((8 * sl) + 7));
+				for (sct = 0; sct < 8; sct++) {
+					len += sprintf(page + len, " %02x",
+						       sense[8 * sl + sct]);
+				}
+				len += sprintf(page + len, "\n");
+			}
+
+			if (sense[27] & DASD_SENSE_BIT_0) {
+				/* 24 Byte Sense Data */
+				sprintf(page + len, PRINTK_HEADER
+					" 24 Byte: %x MSG %x, "
+					"%s MSGb to SYSOP\n",
+					sense[7] >> 4, sense[7] & 0x0f,
+					sense[1] & 0x10 ? "" : "no");
+			} else {
+				/* 32 Byte Sense Data */
+				sprintf(page + len, PRINTK_HEADER
+					" 32 Byte: Format: %x "
+					"Exception class %x\n",
+					sense[6] & 0x0f, sense[22] >> 4);
+			}
+		} else {
+			sprintf(page + len, PRINTK_HEADER
+				" SORRY - NO VALID SENSE AVAILABLE\n");
+		}
+	} else {
+		sprintf(page + len, PRINTK_HEADER
+			" SORRY - NO TSB DATA AVAILABLE\n");
+	}
+	printk(KERN_ERR "%s", page);
+	free_page((unsigned long) page);
+}
+
+static void dasd_eckd_dump_sense(struct dasd_device *device,
+				 struct dasd_ccw_req *req, struct irb *irb)
+{
+	u8 *sense = dasd_get_sense(irb);
+
+	if (scsw_is_tm(&irb->scsw)) {
+		/*
+		 * In some cases the 'File Protected' or 'Incorrect Length'
+		 * error might be expected and log messages shouldn't be written
+		 * then. Check if the according suppress bit is set.
+		 */
+		if (sense && (sense[1] & SNS1_FILE_PROTECTED) &&
+		    test_bit(DASD_CQR_SUPPRESS_FP, &req->flags))
+			return;
+		if (scsw_cstat(&irb->scsw) == 0x40 &&
+		    test_bit(DASD_CQR_SUPPRESS_IL, &req->flags))
+			return;
+
+		dasd_eckd_dump_sense_tcw(device, req, irb);
+	} else {
+		/*
+		 * In some cases the 'Command Reject' or 'No Record Found'
+		 * error might be expected and log messages shouldn't be
+		 * written then. Check if the according suppress bit is set.
+		 */
+		if (sense && sense[0] & SNS0_CMD_REJECT &&
+		    test_bit(DASD_CQR_SUPPRESS_CR, &req->flags))
+			return;
+
+		if (sense && sense[1] & SNS1_NO_REC_FOUND &&
+		    test_bit(DASD_CQR_SUPPRESS_NRF, &req->flags))
+			return;
+
+		dasd_eckd_dump_sense_ccw(device, req, irb);
+	}
+}
+
+static int dasd_eckd_pm_freeze(struct dasd_device *device)
+{
+	/*
+	 * the device should be disconnected from our LCU structure
+	 * on restore we will reconnect it and reread LCU specific
+	 * information like PAV support that might have changed
+	 */
+	dasd_alias_remove_device(device);
+	dasd_alias_disconnect_device_from_lcu(device);
+
+	return 0;
+}
+
+static int dasd_eckd_restore_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct dasd_eckd_characteristics temp_rdc_data;
+	int rc;
+	struct dasd_uid temp_uid;
+	unsigned long flags;
+	unsigned long cqr_flags = 0;
+
+	/* Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+				"Read configuration data failed, rc=%d", rc);
+		goto out_err;
+	}
+
+	dasd_eckd_get_uid(device, &temp_uid);
+	/* Generate device unique id */
+	rc = dasd_eckd_generate_uid(device);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	if (memcmp(&private->uid, &temp_uid, sizeof(struct dasd_uid)) != 0)
+		dev_err(&device->cdev->dev, "The UID of the DASD has "
+			"changed\n");
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	if (rc)
+		goto out_err;
+
+	/* register lcu with alias handling, enable PAV if this is a new lcu */
+	rc = dasd_alias_make_device_known_to_lcu(device);
+	if (rc)
+		goto out_err;
+
+	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr_flags);
+	dasd_eckd_validate_server(device, cqr_flags);
+
+	/* RE-Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+			"Read configuration data failed, rc=%d", rc);
+		goto out_err2;
+	}
+
+	/* Read Feature Codes */
+	dasd_eckd_read_features(device);
+
+	/* Read Device Characteristics */
+	rc = dasd_generic_read_dev_chars(device, DASD_ECKD_MAGIC,
+					 &temp_rdc_data, 64);
+	if (rc) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+				"Read device characteristic failed, rc=%d", rc);
+		goto out_err2;
+	}
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	memcpy(&private->rdc_data, &temp_rdc_data, sizeof(temp_rdc_data));
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+	/* add device to alias management */
+	dasd_alias_add_device(device);
+
+	return 0;
+
+out_err2:
+	dasd_alias_disconnect_device_from_lcu(device);
+out_err:
+	return -1;
+}
+
+static int dasd_eckd_reload_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	int rc, old_base;
+	char print_uid[60];
+	struct dasd_uid uid;
+	unsigned long flags;
+
+	/*
+	 * remove device from alias handling to prevent new requests
+	 * from being scheduled on the wrong alias device
+	 */
+	dasd_alias_remove_device(device);
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	old_base = private->uid.base_unit_addr;
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+	/* Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc)
+		goto out_err;
+
+	rc = dasd_eckd_generate_uid(device);
+	if (rc)
+		goto out_err;
+	/*
+	 * update unit address configuration and
+	 * add device to alias management
+	 */
+	dasd_alias_update_add_device(device);
+
+	dasd_eckd_get_uid(device, &uid);
+
+	if (old_base != uid.base_unit_addr) {
+		if (strlen(uid.vduit) > 0)
+			snprintf(print_uid, sizeof(print_uid),
+				 "%s.%s.%04x.%02x.%s", uid.vendor, uid.serial,
+				 uid.ssid, uid.base_unit_addr, uid.vduit);
+		else
+			snprintf(print_uid, sizeof(print_uid),
+				 "%s.%s.%04x.%02x", uid.vendor, uid.serial,
+				 uid.ssid, uid.base_unit_addr);
+
+		dev_info(&device->cdev->dev,
+			 "An Alias device was reassigned to a new base device "
+			 "with UID: %s\n", print_uid);
+	}
+	return 0;
+
+out_err:
+	return -1;
+}
+
+static int dasd_eckd_read_message_buffer(struct dasd_device *device,
+					 struct dasd_rssd_messages *messages,
+					 __u8 lpum)
+{
+	struct dasd_rssd_messages *message_buf;
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
+				   (sizeof(struct dasd_psf_prssd_data) +
+				    sizeof(struct dasd_rssd_messages)),
+				   device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate read message buffer request");
+		return PTR_ERR(cqr);
+	}
+
+	cqr->lpm = lpum;
+retry:
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->expires = 10 * HZ;
+	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
+	/* dasd_sleep_on_immediatly does not do complex error
+	 * recovery so clear erp flag and set retry counter to
+	 * do basic erp */
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->retries = 256;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = 0x03;	/* Message Buffer */
+	/* all other bytes of prssdp must be zero */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->cda = (__u32)(addr_t) prssdp;
+
+	/* Read Subsystem Data - message buffer */
+	message_buf = (struct dasd_rssd_messages *) (prssdp + 1);
+	memset(message_buf, 0, sizeof(struct dasd_rssd_messages));
+
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(struct dasd_rssd_messages);
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->cda = (__u32)(addr_t) message_buf;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	rc = dasd_sleep_on_immediatly(cqr);
+	if (rc == 0) {
+		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+		message_buf = (struct dasd_rssd_messages *)
+			(prssdp + 1);
+		memcpy(messages, message_buf,
+		       sizeof(struct dasd_rssd_messages));
+	} else if (cqr->lpm) {
+		/*
+		 * on z/VM we might not be able to do I/O on the requested path
+		 * but instead we get the required information on any path
+		 * so retry with open path mask
+		 */
+		cqr->lpm = 0;
+		goto retry;
+	} else
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+				"Reading messages failed with rc=%d\n"
+				, rc);
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+static int dasd_eckd_query_host_access(struct dasd_device *device,
+				       struct dasd_psf_query_host_access *data)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct dasd_psf_query_host_access *host_access;
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+
+	/* not available for HYPER PAV alias devices */
+	if (!device->block && private->lcu->pav == HYPER_PAV)
+		return -EOPNOTSUPP;
+
+	/* may not be supported by the storage server */
+	if (!(private->features.feature[14] & 0x80))
+		return -EOPNOTSUPP;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
+				   sizeof(struct dasd_psf_prssd_data) + 1,
+				   device, NULL);
+	if (IS_ERR(cqr)) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate read message buffer request");
+		return PTR_ERR(cqr);
+	}
+	host_access = kzalloc(sizeof(*host_access), GFP_KERNEL | GFP_DMA);
+	if (!host_access) {
+		dasd_sfree_request(cqr, device);
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate host_access buffer");
+		return -ENOMEM;
+	}
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->retries = 256;
+	cqr->expires = 10 * HZ;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = PSF_SUBORDER_QHA;	/* query host access */
+	/* LSS and Volume that will be queried */
+	prssdp->lss = private->ned->ID;
+	prssdp->volume = private->ned->unit_addr;
+	/* all other bytes of prssdp must be zero */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->cda = (__u32)(addr_t) prssdp;
+
+	/* Read Subsystem Data - query host access */
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(struct dasd_psf_query_host_access);
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->cda = (__u32)(addr_t) host_access;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	/* the command might not be supported, suppress error message */
+	__set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);
+	rc = dasd_sleep_on_interruptible(cqr);
+	if (rc == 0) {
+		*data = *host_access;
+	} else {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+				"Reading host access data failed with rc=%d\n",
+				rc);
+		rc = -EOPNOTSUPP;
+	}
+
+	dasd_sfree_request(cqr, cqr->memdev);
+	kfree(host_access);
+	return rc;
+}
+/*
+ * return number of grouped devices
+ */
+static int dasd_eckd_host_access_count(struct dasd_device *device)
+{
+	struct dasd_psf_query_host_access *access;
+	struct dasd_ckd_path_group_entry *entry;
+	struct dasd_ckd_host_information *info;
+	int count = 0;
+	int rc, i;
+
+	access = kzalloc(sizeof(*access), GFP_NOIO);
+	if (!access) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate access buffer");
+		return -ENOMEM;
+	}
+	rc = dasd_eckd_query_host_access(device, access);
+	if (rc) {
+		kfree(access);
+		return rc;
+	}
+
+	info = (struct dasd_ckd_host_information *)
+		access->host_access_information;
+	for (i = 0; i < info->entry_count; i++) {
+		entry = (struct dasd_ckd_path_group_entry *)
+			(info->entry + i * info->entry_size);
+		if (entry->status_flags & DASD_ECKD_PG_GROUPED)
+			count++;
+	}
+
+	kfree(access);
+	return count;
+}
+
+/*
+ * write host access information to a sequential file
+ */
+static int dasd_hosts_print(struct dasd_device *device, struct seq_file *m)
+{
+	struct dasd_psf_query_host_access *access;
+	struct dasd_ckd_path_group_entry *entry;
+	struct dasd_ckd_host_information *info;
+	char sysplex[9] = "";
+	int rc, i;
+
+	access = kzalloc(sizeof(*access), GFP_NOIO);
+	if (!access) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate access buffer");
+		return -ENOMEM;
+	}
+	rc = dasd_eckd_query_host_access(device, access);
+	if (rc) {
+		kfree(access);
+		return rc;
+	}
+
+	info = (struct dasd_ckd_host_information *)
+		access->host_access_information;
+	for (i = 0; i < info->entry_count; i++) {
+		entry = (struct dasd_ckd_path_group_entry *)
+			(info->entry + i * info->entry_size);
+		/* PGID */
+		seq_printf(m, "pgid %*phN\n", 11, entry->pgid);
+		/* FLAGS */
+		seq_printf(m, "status_flags %02x\n", entry->status_flags);
+		/* SYSPLEX NAME */
+		memcpy(&sysplex, &entry->sysplex_name, sizeof(sysplex) - 1);
+		EBCASC(sysplex, sizeof(sysplex));
+		seq_printf(m, "sysplex_name %8s\n", sysplex);
+		/* SUPPORTED CYLINDER */
+		seq_printf(m, "supported_cylinder %d\n", entry->cylinder);
+		/* TIMESTAMP */
+		seq_printf(m, "timestamp %lu\n", (unsigned long)
+			   entry->timestamp);
+	}
+	kfree(access);
+
+	return 0;
+}
+
+/*
+ * Perform Subsystem Function - CUIR response
+ */
+static int
+dasd_eckd_psf_cuir_response(struct dasd_device *device, int response,
+			    __u32 message_id, __u8 lpum)
+{
+	struct dasd_psf_cuir_response *psf_cuir;
+	int pos = pathmask_to_pos(lpum);
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
+				   sizeof(struct dasd_psf_cuir_response),
+				   device, NULL);
+
+	if (IS_ERR(cqr)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			   "Could not allocate PSF-CUIR request");
+		return PTR_ERR(cqr);
+	}
+
+	psf_cuir = (struct dasd_psf_cuir_response *)cqr->data;
+	psf_cuir->order = PSF_ORDER_CUIR_RESPONSE;
+	psf_cuir->cc = response;
+	psf_cuir->chpid = device->path[pos].chpid;
+	psf_cuir->message_id = message_id;
+	psf_cuir->cssid = device->path[pos].cssid;
+	psf_cuir->ssid = device->path[pos].ssid;
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->cda = (__u32)(addr_t)psf_cuir;
+	ccw->flags = CCW_FLAG_SLI;
+	ccw->count = sizeof(struct dasd_psf_cuir_response);
+
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->retries = 256;
+	cqr->expires = 10*HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
+
+	rc = dasd_sleep_on(cqr);
+
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+/*
+ * return configuration data that is referenced by record selector
+ * if a record selector is specified or per default return the
+ * conf_data pointer for the path specified by lpum
+ */
+static struct dasd_conf_data *dasd_eckd_get_ref_conf(struct dasd_device *device,
+						     __u8 lpum,
+						     struct dasd_cuir_message *cuir)
+{
+	struct dasd_conf_data *conf_data;
+	int path, pos;
+
+	if (cuir->record_selector == 0)
+		goto out;
+	for (path = 0x80, pos = 0; path; path >>= 1, pos++) {
+		conf_data = device->path[pos].conf_data;
+		if (conf_data->gneq.record_selector ==
+		    cuir->record_selector)
+			return conf_data;
+	}
+out:
+	return device->path[pathmask_to_pos(lpum)].conf_data;
+}
+
+/*
+ * This function determines the scope of a reconfiguration request by
+ * analysing the path and device selection data provided in the CUIR request.
+ * Returns a path mask containing CUIR affected paths for the give device.
+ *
+ * If the CUIR request does not contain the required information return the
+ * path mask of the path the attention message for the CUIR request was reveived
+ * on.
+ */
+static int dasd_eckd_cuir_scope(struct dasd_device *device, __u8 lpum,
+				struct dasd_cuir_message *cuir)
+{
+	struct dasd_conf_data *ref_conf_data;
+	unsigned long bitmask = 0, mask = 0;
+	struct dasd_conf_data *conf_data;
+	unsigned int pos, path;
+	char *ref_gneq, *gneq;
+	char *ref_ned, *ned;
+	int tbcpm = 0;
+
+	/* if CUIR request does not specify the scope use the path
+	   the attention message was presented on */
+	if (!cuir->ned_map ||
+	    !(cuir->neq_map[0] | cuir->neq_map[1] | cuir->neq_map[2]))
+		return lpum;
+
+	/* get reference conf data */
+	ref_conf_data = dasd_eckd_get_ref_conf(device, lpum, cuir);
+	/* reference ned is determined by ned_map field */
+	pos = 8 - ffs(cuir->ned_map);
+	ref_ned = (char *)&ref_conf_data->neds[pos];
+	ref_gneq = (char *)&ref_conf_data->gneq;
+	/* transfer 24 bit neq_map to mask */
+	mask = cuir->neq_map[2];
+	mask |= cuir->neq_map[1] << 8;
+	mask |= cuir->neq_map[0] << 16;
+
+	for (path = 0; path < 8; path++) {
+		/* initialise data per path */
+		bitmask = mask;
+		conf_data = device->path[path].conf_data;
+		pos = 8 - ffs(cuir->ned_map);
+		ned = (char *) &conf_data->neds[pos];
+		/* compare reference ned and per path ned */
+		if (memcmp(ref_ned, ned, sizeof(*ned)) != 0)
+			continue;
+		gneq = (char *)&conf_data->gneq;
+		/* compare reference gneq and per_path gneq under
+		   24 bit mask where mask bit 0 equals byte 7 of
+		   the gneq and mask bit 24 equals byte 31 */
+		while (bitmask) {
+			pos = ffs(bitmask) - 1;
+			if (memcmp(&ref_gneq[31 - pos], &gneq[31 - pos], 1)
+			    != 0)
+				break;
+			clear_bit(pos, &bitmask);
+		}
+		if (bitmask)
+			continue;
+		/* device and path match the reference values
+		   add path to CUIR scope */
+		tbcpm |= 0x80 >> path;
+	}
+	return tbcpm;
+}
+
+static void dasd_eckd_cuir_notify_user(struct dasd_device *device,
+				       unsigned long paths, int action)
+{
+	int pos;
+
+	while (paths) {
+		/* get position of bit in mask */
+		pos = 8 - ffs(paths);
+		/* get channel path descriptor from this position */
+		if (action == CUIR_QUIESCE)
+			pr_warn("Service on the storage server caused path %x.%02x to go offline",
+				device->path[pos].cssid,
+				device->path[pos].chpid);
+		else if (action == CUIR_RESUME)
+			pr_info("Path %x.%02x is back online after service on the storage server",
+				device->path[pos].cssid,
+				device->path[pos].chpid);
+		clear_bit(7 - pos, &paths);
+	}
+}
+
+static int dasd_eckd_cuir_remove_path(struct dasd_device *device, __u8 lpum,
+				      struct dasd_cuir_message *cuir)
+{
+	unsigned long tbcpm;
+
+	tbcpm = dasd_eckd_cuir_scope(device, lpum, cuir);
+	/* nothing to do if path is not in use */
+	if (!(dasd_path_get_opm(device) & tbcpm))
+		return 0;
+	if (!(dasd_path_get_opm(device) & ~tbcpm)) {
+		/* no path would be left if the CUIR action is taken
+		   return error */
+		return -EINVAL;
+	}
+	/* remove device from operational path mask */
+	dasd_path_remove_opm(device, tbcpm);
+	dasd_path_add_cuirpm(device, tbcpm);
+	return tbcpm;
+}
+
+/*
+ * walk through all devices and build a path mask to quiesce them
+ * return an error if the last path to a device would be removed
+ *
+ * if only part of the devices are quiesced and an error
+ * occurs no onlining necessary, the storage server will
+ * notify the already set offline devices again
+ */
+static int dasd_eckd_cuir_quiesce(struct dasd_device *device, __u8 lpum,
+				  struct dasd_cuir_message *cuir)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *pavgroup, *tempgroup;
+	struct dasd_device *dev, *n;
+	unsigned long paths = 0;
+	unsigned long flags;
+	int tbcpm;
+
+	/* active devices */
+	list_for_each_entry_safe(dev, n, &private->lcu->active_devices,
+				 alias_list) {
+		spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
+		tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
+		spin_unlock_irqrestore(get_ccwdev_lock(dev->cdev), flags);
+		if (tbcpm < 0)
+			goto out_err;
+		paths |= tbcpm;
+	}
+	/* inactive devices */
+	list_for_each_entry_safe(dev, n, &private->lcu->inactive_devices,
+				 alias_list) {
+		spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
+		tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
+		spin_unlock_irqrestore(get_ccwdev_lock(dev->cdev), flags);
+		if (tbcpm < 0)
+			goto out_err;
+		paths |= tbcpm;
+	}
+	/* devices in PAV groups */
+	list_for_each_entry_safe(pavgroup, tempgroup,
+				 &private->lcu->grouplist, group) {
+		list_for_each_entry_safe(dev, n, &pavgroup->baselist,
+					 alias_list) {
+			spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
+			tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
+			spin_unlock_irqrestore(
+				get_ccwdev_lock(dev->cdev), flags);
+			if (tbcpm < 0)
+				goto out_err;
+			paths |= tbcpm;
+		}
+		list_for_each_entry_safe(dev, n, &pavgroup->aliaslist,
+					 alias_list) {
+			spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
+			tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
+			spin_unlock_irqrestore(
+				get_ccwdev_lock(dev->cdev), flags);
+			if (tbcpm < 0)
+				goto out_err;
+			paths |= tbcpm;
+		}
+	}
+	/* notify user about all paths affected by CUIR action */
+	dasd_eckd_cuir_notify_user(device, paths, CUIR_QUIESCE);
+	return 0;
+out_err:
+	return tbcpm;
+}
+
+static int dasd_eckd_cuir_resume(struct dasd_device *device, __u8 lpum,
+				 struct dasd_cuir_message *cuir)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *pavgroup, *tempgroup;
+	struct dasd_device *dev, *n;
+	unsigned long paths = 0;
+	int tbcpm;
+
+	/*
+	 * the path may have been added through a generic path event before
+	 * only trigger path verification if the path is not already in use
+	 */
+	list_for_each_entry_safe(dev, n,
+				 &private->lcu->active_devices,
+				 alias_list) {
+		tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
+		paths |= tbcpm;
+		if (!(dasd_path_get_opm(dev) & tbcpm)) {
+			dasd_path_add_tbvpm(dev, tbcpm);
+			dasd_schedule_device_bh(dev);
+		}
+	}
+	list_for_each_entry_safe(dev, n,
+				 &private->lcu->inactive_devices,
+				 alias_list) {
+		tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
+		paths |= tbcpm;
+		if (!(dasd_path_get_opm(dev) & tbcpm)) {
+			dasd_path_add_tbvpm(dev, tbcpm);
+			dasd_schedule_device_bh(dev);
+		}
+	}
+	/* devices in PAV groups */
+	list_for_each_entry_safe(pavgroup, tempgroup,
+				 &private->lcu->grouplist,
+				 group) {
+		list_for_each_entry_safe(dev, n,
+					 &pavgroup->baselist,
+					 alias_list) {
+			tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
+			paths |= tbcpm;
+			if (!(dasd_path_get_opm(dev) & tbcpm)) {
+				dasd_path_add_tbvpm(dev, tbcpm);
+				dasd_schedule_device_bh(dev);
+			}
+		}
+		list_for_each_entry_safe(dev, n,
+					 &pavgroup->aliaslist,
+					 alias_list) {
+			tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
+			paths |= tbcpm;
+			if (!(dasd_path_get_opm(dev) & tbcpm)) {
+				dasd_path_add_tbvpm(dev, tbcpm);
+				dasd_schedule_device_bh(dev);
+			}
+		}
+	}
+	/* notify user about all paths affected by CUIR action */
+	dasd_eckd_cuir_notify_user(device, paths, CUIR_RESUME);
+	return 0;
+}
+
+static void dasd_eckd_handle_cuir(struct dasd_device *device, void *messages,
+				 __u8 lpum)
+{
+	struct dasd_cuir_message *cuir = messages;
+	int response;
+
+	DBF_DEV_EVENT(DBF_WARNING, device,
+		      "CUIR request: %016llx %016llx %016llx %08x",
+		      ((u64 *)cuir)[0], ((u64 *)cuir)[1], ((u64 *)cuir)[2],
+		      ((u32 *)cuir)[3]);
+
+	if (cuir->code == CUIR_QUIESCE) {
+		/* quiesce */
+		if (dasd_eckd_cuir_quiesce(device, lpum, cuir))
+			response = PSF_CUIR_LAST_PATH;
+		else
+			response = PSF_CUIR_COMPLETED;
+	} else if (cuir->code == CUIR_RESUME) {
+		/* resume */
+		dasd_eckd_cuir_resume(device, lpum, cuir);
+		response = PSF_CUIR_COMPLETED;
+	} else
+		response = PSF_CUIR_NOT_SUPPORTED;
+
+	dasd_eckd_psf_cuir_response(device, response,
+				    cuir->message_id, lpum);
+	DBF_DEV_EVENT(DBF_WARNING, device,
+		      "CUIR response: %d on message ID %08x", response,
+		      cuir->message_id);
+	/* to make sure there is no attention left schedule work again */
+	device->discipline->check_attention(device, lpum);
+}
+
+static void dasd_eckd_check_attention_work(struct work_struct *work)
+{
+	struct check_attention_work_data *data;
+	struct dasd_rssd_messages *messages;
+	struct dasd_device *device;
+	int rc;
+
+	data = container_of(work, struct check_attention_work_data, worker);
+	device = data->device;
+	messages = kzalloc(sizeof(*messages), GFP_KERNEL);
+	if (!messages) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "Could not allocate attention message buffer");
+		goto out;
+	}
+	rc = dasd_eckd_read_message_buffer(device, messages, data->lpum);
+	if (rc)
+		goto out;
+	if (messages->length == ATTENTION_LENGTH_CUIR &&
+	    messages->format == ATTENTION_FORMAT_CUIR)
+		dasd_eckd_handle_cuir(device, messages, data->lpum);
+out:
+	dasd_put_device(device);
+	kfree(messages);
+	kfree(data);
+}
+
+static int dasd_eckd_check_attention(struct dasd_device *device, __u8 lpum)
+{
+	struct check_attention_work_data *data;
+
+	data = kzalloc(sizeof(*data), GFP_ATOMIC);
+	if (!data)
+		return -ENOMEM;
+	INIT_WORK(&data->worker, dasd_eckd_check_attention_work);
+	dasd_get_device(device);
+	data->device = device;
+	data->lpum = lpum;
+	schedule_work(&data->worker);
+	return 0;
+}
+
+static int dasd_eckd_disable_hpf_path(struct dasd_device *device, __u8 lpum)
+{
+	if (~lpum & dasd_path_get_opm(device)) {
+		dasd_path_add_nohpfpm(device, lpum);
+		dasd_path_remove_opm(device, lpum);
+		dev_err(&device->cdev->dev,
+			"Channel path %02X lost HPF functionality and is disabled\n",
+			lpum);
+		return 1;
+	}
+	return 0;
+}
+
+static void dasd_eckd_disable_hpf_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	dev_err(&device->cdev->dev,
+		"High Performance FICON disabled\n");
+	private->fcx_max_data = 0;
+}
+
+static int dasd_eckd_hpf_enabled(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	return private->fcx_max_data ? 1 : 0;
+}
+
+static void dasd_eckd_handle_hpf_error(struct dasd_device *device,
+				       struct irb *irb)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	if (!private->fcx_max_data) {
+		/* sanity check for no HPF, the error makes no sense */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "Trying to disable HPF for a non HPF device");
+		return;
+	}
+	if (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX) {
+		dasd_eckd_disable_hpf_device(device);
+	} else if (irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX) {
+		if (dasd_eckd_disable_hpf_path(device, irb->esw.esw1.lpum))
+			return;
+		dasd_eckd_disable_hpf_device(device);
+		dasd_path_set_tbvpm(device,
+				  dasd_path_get_hpfpm(device));
+	}
+	/*
+	 * prevent that any new I/O ist started on the device and schedule a
+	 * requeue of existing requests
+	 */
+	dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
+	dasd_schedule_requeue(device);
+}
+
+static struct ccw_driver dasd_eckd_driver = {
+	.driver = {
+		.name	= "dasd-eckd",
+		.owner	= THIS_MODULE,
+	},
+	.ids	     = dasd_eckd_ids,
+	.probe	     = dasd_eckd_probe,
+	.remove      = dasd_generic_remove,
+	.set_offline = dasd_generic_set_offline,
+	.set_online  = dasd_eckd_set_online,
+	.notify      = dasd_generic_notify,
+	.path_event  = dasd_generic_path_event,
+	.shutdown    = dasd_generic_shutdown,
+	.freeze      = dasd_generic_pm_freeze,
+	.thaw	     = dasd_generic_restore_device,
+	.restore     = dasd_generic_restore_device,
+	.uc_handler  = dasd_generic_uc_handler,
+	.int_class   = IRQIO_DAS,
+};
+
+/*
+ * max_blocks is dependent on the amount of storage that is available
+ * in the static io buffer for each device. Currently each device has
+ * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
+ * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
+ * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
+ * addition we have one define extent ccw + 16 bytes of data and one
+ * locate record ccw + 16 bytes of data. That makes:
+ * (8192 - 24 - 136 - 8 - 16 - 8 - 16) / 16 = 499 blocks at maximum.
+ * We want to fit two into the available memory so that we can immediately
+ * start the next request if one finishes off. That makes 249.5 blocks
+ * for one request. Give a little safety and the result is 240.
+ */
+static struct dasd_discipline dasd_eckd_discipline = {
+	.owner = THIS_MODULE,
+	.name = "ECKD",
+	.ebcname = "ECKD",
+	.max_blocks = 190,
+	.check_device = dasd_eckd_check_characteristics,
+	.uncheck_device = dasd_eckd_uncheck_device,
+	.do_analysis = dasd_eckd_do_analysis,
+	.verify_path = dasd_eckd_verify_path,
+	.basic_to_ready = dasd_eckd_basic_to_ready,
+	.online_to_ready = dasd_eckd_online_to_ready,
+	.basic_to_known = dasd_eckd_basic_to_known,
+	.fill_geometry = dasd_eckd_fill_geometry,
+	.start_IO = dasd_start_IO,
+	.term_IO = dasd_term_IO,
+	.handle_terminated_request = dasd_eckd_handle_terminated_request,
+	.format_device = dasd_eckd_format_device,
+	.check_device_format = dasd_eckd_check_device_format,
+	.erp_action = dasd_eckd_erp_action,
+	.erp_postaction = dasd_eckd_erp_postaction,
+	.check_for_device_change = dasd_eckd_check_for_device_change,
+	.build_cp = dasd_eckd_build_alias_cp,
+	.free_cp = dasd_eckd_free_alias_cp,
+	.dump_sense = dasd_eckd_dump_sense,
+	.dump_sense_dbf = dasd_eckd_dump_sense_dbf,
+	.fill_info = dasd_eckd_fill_info,
+	.ioctl = dasd_eckd_ioctl,
+	.freeze = dasd_eckd_pm_freeze,
+	.restore = dasd_eckd_restore_device,
+	.reload = dasd_eckd_reload_device,
+	.get_uid = dasd_eckd_get_uid,
+	.kick_validate = dasd_eckd_kick_validate_server,
+	.check_attention = dasd_eckd_check_attention,
+	.host_access_count = dasd_eckd_host_access_count,
+	.hosts_print = dasd_hosts_print,
+	.handle_hpf_error = dasd_eckd_handle_hpf_error,
+	.disable_hpf = dasd_eckd_disable_hpf_device,
+	.hpf_enabled = dasd_eckd_hpf_enabled,
+	.reset_path = dasd_eckd_reset_path,
+};
+
+static int __init
+dasd_eckd_init(void)
+{
+	int ret;
+
+	ASCEBC(dasd_eckd_discipline.ebcname, 4);
+	dasd_reserve_req = kmalloc(sizeof(*dasd_reserve_req),
+				   GFP_KERNEL | GFP_DMA);
+	if (!dasd_reserve_req)
+		return -ENOMEM;
+	path_verification_worker = kmalloc(sizeof(*path_verification_worker),
+				   GFP_KERNEL | GFP_DMA);
+	if (!path_verification_worker) {
+		kfree(dasd_reserve_req);
+		return -ENOMEM;
+	}
+	rawpadpage = (void *)__get_free_page(GFP_KERNEL);
+	if (!rawpadpage) {
+		kfree(path_verification_worker);
+		kfree(dasd_reserve_req);
+		return -ENOMEM;
+	}
+	ret = ccw_driver_register(&dasd_eckd_driver);
+	if (!ret)
+		wait_for_device_probe();
+	else {
+		kfree(path_verification_worker);
+		kfree(dasd_reserve_req);
+		free_page((unsigned long)rawpadpage);
+	}
+	return ret;
+}
+
+static void __exit
+dasd_eckd_cleanup(void)
+{
+	ccw_driver_unregister(&dasd_eckd_driver);
+	kfree(path_verification_worker);
+	kfree(dasd_reserve_req);
+	free_page((unsigned long)rawpadpage);
+}
+
+module_init(dasd_eckd_init);
+module_exit(dasd_eckd_cleanup);
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
new file mode 100644
index 000000000..5869d2fed
--- /dev/null
+++ b/drivers/s390/block/dasd_eckd.h
@@ -0,0 +1,578 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2000
+ *
+ */
+
+#ifndef DASD_ECKD_H
+#define DASD_ECKD_H
+
+/*****************************************************************************
+ * SECTION: CCW Definitions
+ ****************************************************************************/
+#define DASD_ECKD_CCW_WRITE		 0x05
+#define DASD_ECKD_CCW_READ		 0x06
+#define DASD_ECKD_CCW_WRITE_HOME_ADDRESS 0x09
+#define DASD_ECKD_CCW_READ_HOME_ADDRESS	 0x0a
+#define DASD_ECKD_CCW_WRITE_KD		 0x0d
+#define DASD_ECKD_CCW_READ_KD		 0x0e
+#define DASD_ECKD_CCW_ERASE		 0x11
+#define DASD_ECKD_CCW_READ_COUNT	 0x12
+#define DASD_ECKD_CCW_SLCK		 0x14
+#define DASD_ECKD_CCW_WRITE_RECORD_ZERO	 0x15
+#define DASD_ECKD_CCW_READ_RECORD_ZERO	 0x16
+#define DASD_ECKD_CCW_WRITE_CKD		 0x1d
+#define DASD_ECKD_CCW_READ_CKD		 0x1e
+#define DASD_ECKD_CCW_PSF		 0x27
+#define DASD_ECKD_CCW_SNID		 0x34
+#define DASD_ECKD_CCW_RSSD		 0x3e
+#define DASD_ECKD_CCW_LOCATE_RECORD	 0x47
+#define DASD_ECKD_CCW_LOCATE_RECORD_EXT	 0x4b
+#define DASD_ECKD_CCW_SNSS		 0x54
+#define DASD_ECKD_CCW_DEFINE_EXTENT	 0x63
+#define DASD_ECKD_CCW_WRITE_MT		 0x85
+#define DASD_ECKD_CCW_READ_MT		 0x86
+#define DASD_ECKD_CCW_WRITE_KD_MT	 0x8d
+#define DASD_ECKD_CCW_READ_KD_MT	 0x8e
+#define DASD_ECKD_CCW_READ_COUNT_MT	 0x92
+#define DASD_ECKD_CCW_RELEASE		 0x94
+#define DASD_ECKD_CCW_WRITE_FULL_TRACK	 0x95
+#define DASD_ECKD_CCW_READ_CKD_MT	 0x9e
+#define DASD_ECKD_CCW_WRITE_CKD_MT	 0x9d
+#define DASD_ECKD_CCW_WRITE_TRACK_DATA	 0xA5
+#define DASD_ECKD_CCW_READ_TRACK_DATA	 0xA6
+#define DASD_ECKD_CCW_RESERVE		 0xB4
+#define DASD_ECKD_CCW_READ_TRACK	 0xDE
+#define DASD_ECKD_CCW_PFX		 0xE7
+#define DASD_ECKD_CCW_PFX_READ		 0xEA
+#define DASD_ECKD_CCW_RSCK		 0xF9
+#define DASD_ECKD_CCW_RCD		 0xFA
+
+/*
+ * Perform Subsystem Function / Sub-Orders
+ */
+#define PSF_ORDER_PRSSD			 0x18
+#define PSF_ORDER_CUIR_RESPONSE		 0x1A
+#define PSF_SUBORDER_QHA		 0x1C
+#define PSF_ORDER_SSC			 0x1D
+
+/*
+ * CUIR response condition codes
+ */
+#define PSF_CUIR_INVALID		 0x00
+#define PSF_CUIR_COMPLETED		 0x01
+#define PSF_CUIR_NOT_SUPPORTED		 0x02
+#define PSF_CUIR_ERROR_IN_REQ		 0x03
+#define PSF_CUIR_DENIED			 0x04
+#define PSF_CUIR_LAST_PATH		 0x05
+#define PSF_CUIR_DEVICE_ONLINE		 0x06
+#define PSF_CUIR_VARY_FAILURE		 0x07
+#define PSF_CUIR_SOFTWARE_FAILURE	 0x08
+#define PSF_CUIR_NOT_RECOGNIZED		 0x09
+
+/*
+ * CUIR codes
+ */
+#define CUIR_QUIESCE			 0x01
+#define CUIR_RESUME			 0x02
+
+/*
+ * attention message definitions
+ */
+#define ATTENTION_LENGTH_CUIR		 0x0e
+#define ATTENTION_FORMAT_CUIR		 0x01
+
+#define DASD_ECKD_PG_GROUPED		 0x10
+
+/*
+ * Size that is reportet for large volumes in the old 16-bit no_cyl field
+ */
+#define LV_COMPAT_CYL 0xFFFE
+
+
+#define FCX_MAX_DATA_FACTOR 65536
+#define DASD_ECKD_RCD_DATA_SIZE 256
+
+#define DASD_ECKD_PATH_THRHLD		 256
+#define DASD_ECKD_PATH_INTERVAL		 300
+
+/*****************************************************************************
+ * SECTION: Type Definitions
+ ****************************************************************************/
+
+struct eckd_count {
+	__u16 cyl;
+	__u16 head;
+	__u8 record;
+	__u8 kl;
+	__u16 dl;
+} __attribute__ ((packed));
+
+struct ch_t {
+	__u16 cyl;
+	__u16 head;
+} __attribute__ ((packed));
+
+struct chs_t {
+	__u16 cyl;
+	__u16 head;
+	__u32 sector;
+} __attribute__ ((packed));
+
+struct chr_t {
+	__u16 cyl;
+	__u16 head;
+	__u8 record;
+} __attribute__ ((packed));
+
+struct geom_t {
+	__u16 cyl;
+	__u16 head;
+	__u32 sector;
+} __attribute__ ((packed));
+
+struct eckd_home {
+	__u8 skip_control[14];
+	__u16 cell_number;
+	__u8 physical_addr[3];
+	__u8 flag;
+	struct ch_t track_addr;
+	__u8 reserved;
+	__u8 key_length;
+	__u8 reserved2[2];
+} __attribute__ ((packed));
+
+struct DE_eckd_data {
+	struct {
+		unsigned char perm:2;	/* Permissions on this extent */
+		unsigned char reserved:1;
+		unsigned char seek:2;	/* Seek control */
+		unsigned char auth:2;	/* Access authorization */
+		unsigned char pci:1;	/* PCI Fetch mode */
+	} __attribute__ ((packed)) mask;
+	struct {
+		unsigned char mode:2;	/* Architecture mode */
+		unsigned char ckd:1;	/* CKD Conversion */
+		unsigned char operation:3;	/* Operation mode */
+		unsigned char cfw:1;	/* Cache fast write */
+		unsigned char dfw:1;	/* DASD fast write */
+	} __attribute__ ((packed)) attributes;
+	__u16 blk_size;		/* Blocksize */
+	__u16 fast_write_id;
+	__u8 ga_additional;	/* Global Attributes Additional */
+	__u8 ga_extended;	/* Global Attributes Extended	*/
+	struct ch_t beg_ext;
+	struct ch_t end_ext;
+	unsigned long ep_sys_time; /* Ext Parameter - System Time Stamp */
+	__u8 ep_format;        /* Extended Parameter format byte       */
+	__u8 ep_prio;          /* Extended Parameter priority I/O byte */
+	__u8 ep_reserved1;     /* Extended Parameter Reserved	       */
+	__u8 ep_rec_per_track; /* Number of records on a track	       */
+	__u8 ep_reserved[4];   /* Extended Parameter Reserved	       */
+} __attribute__ ((packed));
+
+struct LO_eckd_data {
+	struct {
+		unsigned char orientation:2;
+		unsigned char operation:6;
+	} __attribute__ ((packed)) operation;
+	struct {
+		unsigned char last_bytes_used:1;
+		unsigned char reserved:6;
+		unsigned char read_count_suffix:1;
+	} __attribute__ ((packed)) auxiliary;
+	__u8 unused;
+	__u8 count;
+	struct ch_t seek_addr;
+	struct chr_t search_arg;
+	__u8 sector;
+	__u16 length;
+} __attribute__ ((packed));
+
+struct LRE_eckd_data {
+	struct {
+		unsigned char orientation:2;
+		unsigned char operation:6;
+	} __attribute__ ((packed)) operation;
+	struct {
+		unsigned char length_valid:1;
+		unsigned char length_scope:1;
+		unsigned char imbedded_ccw_valid:1;
+		unsigned char check_bytes:2;
+		unsigned char imbedded_count_valid:1;
+		unsigned char reserved:1;
+		unsigned char read_count_suffix:1;
+	} __attribute__ ((packed)) auxiliary;
+	__u8 imbedded_ccw;
+	__u8 count;
+	struct ch_t seek_addr;
+	struct chr_t search_arg;
+	__u8 sector;
+	__u16 length;
+	__u8 imbedded_count;
+	__u8 extended_operation;
+	__u16 extended_parameter_length;
+	__u8 extended_parameter[0];
+} __attribute__ ((packed));
+
+/* Prefix data for format 0x00 and 0x01 */
+struct PFX_eckd_data {
+	unsigned char format;
+	struct {
+		unsigned char define_extent:1;
+		unsigned char time_stamp:1;
+		unsigned char verify_base:1;
+		unsigned char hyper_pav:1;
+		unsigned char reserved:4;
+	} __attribute__ ((packed)) validity;
+	__u8 base_address;
+	__u8 aux;
+	__u8 base_lss;
+	__u8 reserved[7];
+	struct DE_eckd_data define_extent;
+	struct LRE_eckd_data locate_record;
+} __attribute__ ((packed));
+
+struct dasd_eckd_characteristics {
+	__u16 cu_type;
+	struct {
+		unsigned char support:2;
+		unsigned char async:1;
+		unsigned char reserved:1;
+		unsigned char cache_info:1;
+		unsigned char model:3;
+	} __attribute__ ((packed)) cu_model;
+	__u16 dev_type;
+	__u8 dev_model;
+	struct {
+		unsigned char mult_burst:1;
+		unsigned char RT_in_LR:1;
+		unsigned char reserved1:1;
+		unsigned char RD_IN_LR:1;
+		unsigned char reserved2:4;
+		unsigned char reserved3:8;
+		unsigned char defect_wr:1;
+		unsigned char XRC_supported:1;
+		unsigned char reserved4:1;
+		unsigned char striping:1;
+		unsigned char reserved5:4;
+		unsigned char cfw:1;
+		unsigned char reserved6:2;
+		unsigned char cache:1;
+		unsigned char dual_copy:1;
+		unsigned char dfw:1;
+		unsigned char reset_alleg:1;
+		unsigned char sense_down:1;
+	} __attribute__ ((packed)) facilities;
+	__u8 dev_class;
+	__u8 unit_type;
+	__u16 no_cyl;
+	__u16 trk_per_cyl;
+	__u8 sec_per_trk;
+	__u8 byte_per_track[3];
+	__u16 home_bytes;
+	__u8 formula;
+	union {
+		struct {
+			__u8 f1;
+			__u16 f2;
+			__u16 f3;
+		} __attribute__ ((packed)) f_0x01;
+		struct {
+			__u8 f1;
+			__u8 f2;
+			__u8 f3;
+			__u8 f4;
+			__u8 f5;
+		} __attribute__ ((packed)) f_0x02;
+	} __attribute__ ((packed)) factors;
+	__u16 first_alt_trk;
+	__u16 no_alt_trk;
+	__u16 first_dia_trk;
+	__u16 no_dia_trk;
+	__u16 first_sup_trk;
+	__u16 no_sup_trk;
+	__u8 MDR_ID;
+	__u8 OBR_ID;
+	__u8 director;
+	__u8 rd_trk_set;
+	__u16 max_rec_zero;
+	__u8 reserved1;
+	__u8 RWANY_in_LR;
+	__u8 factor6;
+	__u8 factor7;
+	__u8 factor8;
+	__u8 reserved2[3];
+	__u8 reserved3[6];
+	__u32 long_no_cyl;
+} __attribute__ ((packed));
+
+/* elements of the configuration data */
+struct dasd_ned {
+	struct {
+		__u8 identifier:2;
+		__u8 token_id:1;
+		__u8 sno_valid:1;
+		__u8 subst_sno:1;
+		__u8 recNED:1;
+		__u8 emuNED:1;
+		__u8 reserved:1;
+	} __attribute__ ((packed)) flags;
+	__u8 descriptor;
+	__u8 dev_class;
+	__u8 reserved;
+	__u8 dev_type[6];
+	__u8 dev_model[3];
+	__u8 HDA_manufacturer[3];
+	__u8 HDA_location[2];
+	__u8 HDA_seqno[12];
+	__u8 ID;
+	__u8 unit_addr;
+} __attribute__ ((packed));
+
+struct dasd_sneq {
+	struct {
+		__u8 identifier:2;
+		__u8 reserved:6;
+	} __attribute__ ((packed)) flags;
+	__u8 res1;
+	__u16 format;
+	__u8 res2[4];		/* byte  4- 7 */
+	__u8 sua_flags;		/* byte  8    */
+	__u8 base_unit_addr;	/* byte  9    */
+	__u8 res3[22];		/* byte 10-31 */
+} __attribute__ ((packed));
+
+struct vd_sneq {
+	struct {
+		__u8 identifier:2;
+		__u8 reserved:6;
+	} __attribute__ ((packed)) flags;
+	__u8 res1;
+	__u16 format;
+	__u8 res2[4];	/* byte  4- 7 */
+	__u8 uit[16];	/* byte  8-23 */
+	__u8 res3[8];	/* byte 24-31 */
+} __attribute__ ((packed));
+
+struct dasd_gneq {
+	struct {
+		__u8 identifier:2;
+		__u8 reserved:6;
+	} __attribute__ ((packed)) flags;
+	__u8 record_selector;
+	__u8 reserved[4];
+	struct {
+		__u8 value:2;
+		__u8 number:6;
+	} __attribute__ ((packed)) timeout;
+	__u8 reserved3;
+	__u16 subsystemID;
+	__u8 reserved2[22];
+} __attribute__ ((packed));
+
+struct dasd_rssd_features {
+	char feature[256];
+} __attribute__((packed));
+
+struct dasd_rssd_messages {
+	__u16 length;
+	__u8 format;
+	__u8 code;
+	__u32 message_id;
+	__u8 flags;
+	char messages[4087];
+} __packed;
+
+struct dasd_cuir_message {
+	__u16 length;
+	__u8 format;
+	__u8 code;
+	__u32 message_id;
+	__u8 flags;
+	__u8 neq_map[3];
+	__u8 ned_map;
+	__u8 record_selector;
+} __packed;
+
+struct dasd_psf_cuir_response {
+	__u8 order;
+	__u8 flags;
+	__u8 cc;
+	__u8 chpid;
+	__u16 device_nr;
+	__u16 reserved;
+	__u32 message_id;
+	__u64 system_id;
+	__u8 cssid;
+	__u8 ssid;
+} __packed;
+
+struct dasd_ckd_path_group_entry {
+	__u8 status_flags;
+	__u8 pgid[11];
+	__u8 sysplex_name[8];
+	__u32 timestamp;
+	__u32 cylinder;
+	__u8 reserved[4];
+} __packed;
+
+struct dasd_ckd_host_information {
+	__u8 access_flags;
+	__u8 entry_size;
+	__u16 entry_count;
+	__u8 entry[16390];
+} __packed;
+
+struct dasd_psf_query_host_access {
+	__u8 access_flag;
+	__u8 version;
+	__u16 CKD_length;
+	__u16 SCSI_length;
+	__u8 unused[10];
+	__u8 host_access_information[16394];
+} __packed;
+
+/*
+ * Perform Subsystem Function - Prepare for Read Subsystem Data
+ */
+struct dasd_psf_prssd_data {
+	unsigned char order;
+	unsigned char flags;
+	unsigned char reserved1;
+	unsigned char reserved2;
+	unsigned char lss;
+	unsigned char volume;
+	unsigned char suborder;
+	unsigned char varies[5];
+} __attribute__ ((packed));
+
+/*
+ * Perform Subsystem Function - Set Subsystem Characteristics
+ */
+struct dasd_psf_ssc_data {
+	unsigned char order;
+	unsigned char flags;
+	unsigned char cu_type[4];
+	unsigned char suborder;
+	unsigned char reserved[59];
+} __attribute__((packed));
+
+
+/*
+ * some structures and definitions for alias handling
+ */
+struct dasd_unit_address_configuration {
+	struct {
+		char ua_type;
+		char base_ua;
+	} unit[256];
+} __attribute__((packed));
+
+
+#define MAX_DEVICES_PER_LCU 256
+
+/* flags on the LCU  */
+#define NEED_UAC_UPDATE  0x01
+#define UPDATE_PENDING	0x02
+
+enum pavtype {NO_PAV, BASE_PAV, HYPER_PAV};
+
+
+struct alias_root {
+	struct list_head serverlist;
+	spinlock_t lock;
+};
+
+struct alias_server {
+	struct list_head server;
+	struct dasd_uid uid;
+	struct list_head lculist;
+};
+
+struct summary_unit_check_work_data {
+	char reason;
+	struct dasd_device *device;
+	struct work_struct worker;
+};
+
+struct read_uac_work_data {
+	struct dasd_device *device;
+	struct delayed_work dwork;
+};
+
+struct alias_lcu {
+	struct list_head lcu;
+	struct dasd_uid uid;
+	enum pavtype pav;
+	char flags;
+	spinlock_t lock;
+	struct list_head grouplist;
+	struct list_head active_devices;
+	struct list_head inactive_devices;
+	struct dasd_unit_address_configuration *uac;
+	struct summary_unit_check_work_data suc_data;
+	struct read_uac_work_data ruac_data;
+	struct dasd_ccw_req *rsu_cqr;
+	struct completion lcu_setup;
+};
+
+struct alias_pav_group {
+	struct list_head group;
+	struct dasd_uid uid;
+	struct alias_lcu *lcu;
+	struct list_head baselist;
+	struct list_head aliaslist;
+	struct dasd_device *next;
+};
+
+struct dasd_conf_data {
+	struct dasd_ned neds[5];
+	u8 reserved[64];
+	struct dasd_gneq gneq;
+} __packed;
+
+struct dasd_eckd_private {
+	struct dasd_eckd_characteristics rdc_data;
+	u8 *conf_data;
+	int conf_len;
+
+	/* pointers to specific parts in the conf_data */
+	struct dasd_ned *ned;
+	struct dasd_sneq *sneq;
+	struct vd_sneq *vdsneq;
+	struct dasd_gneq *gneq;
+
+	struct eckd_count count_area[5];
+	int init_cqr_status;
+	int uses_cdl;
+	struct attrib_data_t attrib;	/* e.g. cache operations */
+	struct dasd_rssd_features features;
+	u32 real_cyl;
+
+	/* alias managemnet */
+	struct dasd_uid uid;
+	struct alias_pav_group *pavgroup;
+	struct alias_lcu *lcu;
+	int count;
+
+	u32 fcx_max_data;
+	char suc_reason;
+};
+
+
+
+int dasd_alias_make_device_known_to_lcu(struct dasd_device *);
+void dasd_alias_disconnect_device_from_lcu(struct dasd_device *);
+int dasd_alias_add_device(struct dasd_device *);
+int dasd_alias_remove_device(struct dasd_device *);
+struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *);
+void dasd_alias_handle_summary_unit_check(struct work_struct *);
+void dasd_eckd_reset_ccw_to_base_io(struct dasd_ccw_req *);
+void dasd_alias_lcu_setup_complete(struct dasd_device *);
+void dasd_alias_wait_for_lcu_setup(struct dasd_device *);
+int dasd_alias_update_add_device(struct dasd_device *);
+#endif				/* DASD_ECKD_H */
diff --git a/drivers/s390/block/dasd_eer.c b/drivers/s390/block/dasd_eer.c
new file mode 100644
index 000000000..93bb09da7
--- /dev/null
+++ b/drivers/s390/block/dasd_eer.c
@@ -0,0 +1,723 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Character device driver for extended error reporting.
+ *
+ *  Copyright IBM Corp. 2005
+ *  extended error reporting for DASD ECKD devices
+ *  Author(s): Stefan Weinhuber <wein@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "dasd-eckd"
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#include <linux/uaccess.h>
+#include <linux/atomic.h>
+#include <asm/ebcdic.h>
+
+#include "dasd_int.h"
+#include "dasd_eckd.h"
+
+#ifdef PRINTK_HEADER
+#undef PRINTK_HEADER
+#endif				/* PRINTK_HEADER */
+#define PRINTK_HEADER "dasd(eer):"
+
+/*
+ * SECTION: the internal buffer
+ */
+
+/*
+ * The internal buffer is meant to store obaque blobs of data, so it does
+ * not know of higher level concepts like triggers.
+ * It consists of a number of pages that are used as a ringbuffer. Each data
+ * blob is stored in a simple record that consists of an integer, which
+ * contains the size of the following data, and the data bytes themselfes.
+ *
+ * To allow for multiple independent readers we create one internal buffer
+ * each time the device is opened and destroy the buffer when the file is
+ * closed again. The number of pages used for this buffer is determined by
+ * the module parmeter eer_pages.
+ *
+ * One record can be written to a buffer by using the functions
+ * - dasd_eer_start_record (one time per record to write the size to the
+ *                          buffer and reserve the space for the data)
+ * - dasd_eer_write_buffer (one or more times per record to write the data)
+ * The data can be written in several steps but you will have to compute
+ * the total size up front for the invocation of dasd_eer_start_record.
+ * If the ringbuffer is full, dasd_eer_start_record will remove the required
+ * number of old records.
+ *
+ * A record is typically read in two steps, first read the integer that
+ * specifies the size of the following data, then read the data.
+ * Both can be done by
+ * - dasd_eer_read_buffer
+ *
+ * For all mentioned functions you need to get the bufferlock first and keep
+ * it until a complete record is written or read.
+ *
+ * All information necessary to keep track of an internal buffer is kept in
+ * a struct eerbuffer. The buffer specific to a file pointer is strored in
+ * the private_data field of that file. To be able to write data to all
+ * existing buffers, each buffer is also added to the bufferlist.
+ * If the user does not want to read a complete record in one go, we have to
+ * keep track of the rest of the record. residual stores the number of bytes
+ * that are still to deliver. If the rest of the record is invalidated between
+ * two reads then residual will be set to -1 so that the next read will fail.
+ * All entries in the eerbuffer structure are protected with the bufferlock.
+ * To avoid races between writing to a buffer on the one side and creating
+ * and destroying buffers on the other side, the bufferlock must also be used
+ * to protect the bufferlist.
+ */
+
+static int eer_pages = 5;
+module_param(eer_pages, int, S_IRUGO|S_IWUSR);
+
+struct eerbuffer {
+	struct list_head list;
+	char **buffer;
+	int buffersize;
+	int buffer_page_count;
+	int head;
+        int tail;
+	int residual;
+};
+
+static LIST_HEAD(bufferlist);
+static DEFINE_SPINLOCK(bufferlock);
+static DECLARE_WAIT_QUEUE_HEAD(dasd_eer_read_wait_queue);
+
+/*
+ * How many free bytes are available on the buffer.
+ * Needs to be called with bufferlock held.
+ */
+static int dasd_eer_get_free_bytes(struct eerbuffer *eerb)
+{
+	if (eerb->head < eerb->tail)
+		return eerb->tail - eerb->head - 1;
+	return eerb->buffersize - eerb->head + eerb->tail -1;
+}
+
+/*
+ * How many bytes of buffer space are used.
+ * Needs to be called with bufferlock held.
+ */
+static int dasd_eer_get_filled_bytes(struct eerbuffer *eerb)
+{
+
+	if (eerb->head >= eerb->tail)
+		return eerb->head - eerb->tail;
+	return eerb->buffersize - eerb->tail + eerb->head;
+}
+
+/*
+ * The dasd_eer_write_buffer function just copies count bytes of data
+ * to the buffer. Make sure to call dasd_eer_start_record first, to
+ * make sure that enough free space is available.
+ * Needs to be called with bufferlock held.
+ */
+static void dasd_eer_write_buffer(struct eerbuffer *eerb,
+				  char *data, int count)
+{
+
+	unsigned long headindex,localhead;
+	unsigned long rest, len;
+	char *nextdata;
+
+	nextdata = data;
+	rest = count;
+	while (rest > 0) {
+ 		headindex = eerb->head / PAGE_SIZE;
+ 		localhead = eerb->head % PAGE_SIZE;
+		len = min(rest, PAGE_SIZE - localhead);
+		memcpy(eerb->buffer[headindex]+localhead, nextdata, len);
+		nextdata += len;
+		rest -= len;
+		eerb->head += len;
+		if (eerb->head == eerb->buffersize)
+			eerb->head = 0; /* wrap around */
+		BUG_ON(eerb->head > eerb->buffersize);
+	}
+}
+
+/*
+ * Needs to be called with bufferlock held.
+ */
+static int dasd_eer_read_buffer(struct eerbuffer *eerb, char *data, int count)
+{
+
+	unsigned long tailindex,localtail;
+	unsigned long rest, len, finalcount;
+	char *nextdata;
+
+	finalcount = min(count, dasd_eer_get_filled_bytes(eerb));
+	nextdata = data;
+	rest = finalcount;
+	while (rest > 0) {
+ 		tailindex = eerb->tail / PAGE_SIZE;
+ 		localtail = eerb->tail % PAGE_SIZE;
+		len = min(rest, PAGE_SIZE - localtail);
+		memcpy(nextdata, eerb->buffer[tailindex] + localtail, len);
+		nextdata += len;
+		rest -= len;
+		eerb->tail += len;
+		if (eerb->tail == eerb->buffersize)
+			eerb->tail = 0; /* wrap around */
+		BUG_ON(eerb->tail > eerb->buffersize);
+	}
+	return finalcount;
+}
+
+/*
+ * Whenever you want to write a blob of data to the internal buffer you
+ * have to start by using this function first. It will write the number
+ * of bytes that will be written to the buffer. If necessary it will remove
+ * old records to make room for the new one.
+ * Needs to be called with bufferlock held.
+ */
+static int dasd_eer_start_record(struct eerbuffer *eerb, int count)
+{
+	int tailcount;
+
+	if (count + sizeof(count) > eerb->buffersize)
+		return -ENOMEM;
+	while (dasd_eer_get_free_bytes(eerb) < count + sizeof(count)) {
+		if (eerb->residual > 0) {
+			eerb->tail += eerb->residual;
+			if (eerb->tail >= eerb->buffersize)
+				eerb->tail -= eerb->buffersize;
+			eerb->residual = -1;
+		}
+		dasd_eer_read_buffer(eerb, (char *) &tailcount,
+				     sizeof(tailcount));
+		eerb->tail += tailcount;
+		if (eerb->tail >= eerb->buffersize)
+			eerb->tail -= eerb->buffersize;
+	}
+	dasd_eer_write_buffer(eerb, (char*) &count, sizeof(count));
+
+	return 0;
+};
+
+/*
+ * Release pages that are not used anymore.
+ */
+static void dasd_eer_free_buffer_pages(char **buf, int no_pages)
+{
+	int i;
+
+	for (i = 0; i < no_pages; i++)
+		free_page((unsigned long) buf[i]);
+}
+
+/*
+ * Allocate a new set of memory pages.
+ */
+static int dasd_eer_allocate_buffer_pages(char **buf, int no_pages)
+{
+	int i;
+
+	for (i = 0; i < no_pages; i++) {
+		buf[i] = (char *) get_zeroed_page(GFP_KERNEL);
+		if (!buf[i]) {
+			dasd_eer_free_buffer_pages(buf, i);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+/*
+ * SECTION: The extended error reporting functionality
+ */
+
+/*
+ * When a DASD device driver wants to report an error, it calls the
+ * function dasd_eer_write and gives the respective trigger ID as
+ * parameter. Currently there are four kinds of triggers:
+ *
+ * DASD_EER_FATALERROR:  all kinds of unrecoverable I/O problems
+ * DASD_EER_PPRCSUSPEND: PPRC was suspended
+ * DASD_EER_NOPATH:      There is no path to the device left.
+ * DASD_EER_STATECHANGE: The state of the device has changed.
+ *
+ * For the first three triggers all required information can be supplied by
+ * the caller. For these triggers a record is written by the function
+ * dasd_eer_write_standard_trigger.
+ *
+ * The DASD_EER_STATECHANGE trigger is special since a sense subsystem
+ * status ccw need to be executed to gather the necessary sense data first.
+ * The dasd_eer_snss function will queue the SNSS request and the request
+ * callback will then call dasd_eer_write with the DASD_EER_STATCHANGE
+ * trigger.
+ *
+ * To avoid memory allocations at runtime, the necessary memory is allocated
+ * when the extended error reporting is enabled for a device (by
+ * dasd_eer_probe). There is one sense subsystem status request for each
+ * eer enabled DASD device. The presence of the cqr in device->eer_cqr
+ * indicates that eer is enable for the device. The use of the snss request
+ * is protected by the DASD_FLAG_EER_IN_USE bit. When this flag indicates
+ * that the cqr is currently in use, dasd_eer_snss cannot start a second
+ * request but sets the DASD_FLAG_EER_SNSS flag instead. The callback of
+ * the SNSS request will check the bit and call dasd_eer_snss again.
+ */
+
+#define SNSS_DATA_SIZE 44
+
+#define DASD_EER_BUSID_SIZE 10
+struct dasd_eer_header {
+	__u32 total_size;
+	__u32 trigger;
+	__u64 tv_sec;
+	__u64 tv_usec;
+	char busid[DASD_EER_BUSID_SIZE];
+} __attribute__ ((packed));
+
+/*
+ * The following function can be used for those triggers that have
+ * all necessary data available when the function is called.
+ * If the parameter cqr is not NULL, the chain of requests will be searched
+ * for valid sense data, and all valid sense data sets will be added to
+ * the triggers data.
+ */
+static void dasd_eer_write_standard_trigger(struct dasd_device *device,
+					    struct dasd_ccw_req *cqr,
+					    int trigger)
+{
+	struct dasd_ccw_req *temp_cqr;
+	int data_size;
+	struct timespec64 ts;
+	struct dasd_eer_header header;
+	unsigned long flags;
+	struct eerbuffer *eerb;
+	char *sense;
+
+	/* go through cqr chain and count the valid sense data sets */
+	data_size = 0;
+	for (temp_cqr = cqr; temp_cqr; temp_cqr = temp_cqr->refers)
+		if (dasd_get_sense(&temp_cqr->irb))
+			data_size += 32;
+
+	header.total_size = sizeof(header) + data_size + 4; /* "EOR" */
+	header.trigger = trigger;
+	ktime_get_real_ts64(&ts);
+	header.tv_sec = ts.tv_sec;
+	header.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+	strlcpy(header.busid, dev_name(&device->cdev->dev),
+		DASD_EER_BUSID_SIZE);
+
+	spin_lock_irqsave(&bufferlock, flags);
+	list_for_each_entry(eerb, &bufferlist, list) {
+		dasd_eer_start_record(eerb, header.total_size);
+		dasd_eer_write_buffer(eerb, (char *) &header, sizeof(header));
+		for (temp_cqr = cqr; temp_cqr; temp_cqr = temp_cqr->refers) {
+			sense = dasd_get_sense(&temp_cqr->irb);
+			if (sense)
+				dasd_eer_write_buffer(eerb, sense, 32);
+		}
+		dasd_eer_write_buffer(eerb, "EOR", 4);
+	}
+	spin_unlock_irqrestore(&bufferlock, flags);
+	wake_up_interruptible(&dasd_eer_read_wait_queue);
+}
+
+/*
+ * This function writes a DASD_EER_STATECHANGE trigger.
+ */
+static void dasd_eer_write_snss_trigger(struct dasd_device *device,
+					struct dasd_ccw_req *cqr,
+					int trigger)
+{
+	int data_size;
+	int snss_rc;
+	struct timespec64 ts;
+	struct dasd_eer_header header;
+	unsigned long flags;
+	struct eerbuffer *eerb;
+
+	snss_rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
+	if (snss_rc)
+		data_size = 0;
+	else
+		data_size = SNSS_DATA_SIZE;
+
+	header.total_size = sizeof(header) + data_size + 4; /* "EOR" */
+	header.trigger = DASD_EER_STATECHANGE;
+	ktime_get_real_ts64(&ts);
+	header.tv_sec = ts.tv_sec;
+	header.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+	strlcpy(header.busid, dev_name(&device->cdev->dev),
+		DASD_EER_BUSID_SIZE);
+
+	spin_lock_irqsave(&bufferlock, flags);
+	list_for_each_entry(eerb, &bufferlist, list) {
+		dasd_eer_start_record(eerb, header.total_size);
+		dasd_eer_write_buffer(eerb, (char *) &header , sizeof(header));
+		if (!snss_rc)
+			dasd_eer_write_buffer(eerb, cqr->data, SNSS_DATA_SIZE);
+		dasd_eer_write_buffer(eerb, "EOR", 4);
+	}
+	spin_unlock_irqrestore(&bufferlock, flags);
+	wake_up_interruptible(&dasd_eer_read_wait_queue);
+}
+
+/*
+ * This function is called for all triggers. It calls the appropriate
+ * function that writes the actual trigger records.
+ */
+void dasd_eer_write(struct dasd_device *device, struct dasd_ccw_req *cqr,
+		    unsigned int id)
+{
+	if (!device->eer_cqr)
+		return;
+	switch (id) {
+	case DASD_EER_FATALERROR:
+	case DASD_EER_PPRCSUSPEND:
+		dasd_eer_write_standard_trigger(device, cqr, id);
+		break;
+	case DASD_EER_NOPATH:
+		dasd_eer_write_standard_trigger(device, NULL, id);
+		break;
+	case DASD_EER_STATECHANGE:
+		dasd_eer_write_snss_trigger(device, cqr, id);
+		break;
+	default: /* unknown trigger, so we write it without any sense data */
+		dasd_eer_write_standard_trigger(device, NULL, id);
+		break;
+	}
+}
+EXPORT_SYMBOL(dasd_eer_write);
+
+/*
+ * Start a sense subsystem status request.
+ * Needs to be called with the device held.
+ */
+void dasd_eer_snss(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+
+	cqr = device->eer_cqr;
+	if (!cqr)	/* Device not eer enabled. */
+		return;
+	if (test_and_set_bit(DASD_FLAG_EER_IN_USE, &device->flags)) {
+		/* Sense subsystem status request in use. */
+		set_bit(DASD_FLAG_EER_SNSS, &device->flags);
+		return;
+	}
+	/* cdev is already locked, can't use dasd_add_request_head */
+	clear_bit(DASD_FLAG_EER_SNSS, &device->flags);
+	cqr->status = DASD_CQR_QUEUED;
+	list_add(&cqr->devlist, &device->ccw_queue);
+	dasd_schedule_device_bh(device);
+}
+
+/*
+ * Callback function for use with sense subsystem status request.
+ */
+static void dasd_eer_snss_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	struct dasd_device *device = cqr->startdev;
+	unsigned long flags;
+
+	dasd_eer_write(device, cqr, DASD_EER_STATECHANGE);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	if (device->eer_cqr == cqr) {
+		clear_bit(DASD_FLAG_EER_IN_USE, &device->flags);
+		if (test_bit(DASD_FLAG_EER_SNSS, &device->flags))
+			/* Another SNSS has been requested in the meantime. */
+			dasd_eer_snss(device);
+		cqr = NULL;
+	}
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	if (cqr)
+		/*
+		 * Extended error recovery has been switched off while
+		 * the SNSS request was running. It could even have
+		 * been switched off and on again in which case there
+		 * is a new ccw in device->eer_cqr. Free the "old"
+		 * snss request now.
+		 */
+		dasd_sfree_request(cqr, device);
+}
+
+/*
+ * Enable error reporting on a given device.
+ */
+int dasd_eer_enable(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr = NULL;
+	unsigned long flags;
+	struct ccw1 *ccw;
+	int rc = 0;
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	if (device->eer_cqr)
+		goto out;
+	else if (!device->discipline ||
+		 strcmp(device->discipline->name, "ECKD"))
+		rc = -EMEDIUMTYPE;
+	else if (test_bit(DASD_FLAG_OFFLINE, &device->flags))
+		rc = -EBUSY;
+
+	if (rc)
+		goto out;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* SNSS */,
+				   SNSS_DATA_SIZE, device, NULL);
+	if (IS_ERR(cqr)) {
+		rc = -ENOMEM;
+		cqr = NULL;
+		goto out;
+	}
+
+	cqr->startdev = device;
+	cqr->retries = 255;
+	cqr->expires = 10 * HZ;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_SNSS;
+	ccw->count = SNSS_DATA_SIZE;
+	ccw->flags = 0;
+	ccw->cda = (__u32)(addr_t) cqr->data;
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	cqr->callback = dasd_eer_snss_cb;
+
+	if (!device->eer_cqr) {
+		device->eer_cqr = cqr;
+		cqr = NULL;
+	}
+
+out:
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+	if (cqr)
+		dasd_sfree_request(cqr, device);
+
+	return rc;
+}
+
+/*
+ * Disable error reporting on a given device.
+ */
+void dasd_eer_disable(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	unsigned long flags;
+	int in_use;
+
+	if (!device->eer_cqr)
+		return;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	cqr = device->eer_cqr;
+	device->eer_cqr = NULL;
+	clear_bit(DASD_FLAG_EER_SNSS, &device->flags);
+	in_use = test_and_clear_bit(DASD_FLAG_EER_IN_USE, &device->flags);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	if (cqr && !in_use)
+		dasd_sfree_request(cqr, device);
+}
+
+/*
+ * SECTION: the device operations
+ */
+
+/*
+ * On the one side we need a lock to access our internal buffer, on the
+ * other side a copy_to_user can sleep. So we need to copy the data we have
+ * to transfer in a readbuffer, which is protected by the readbuffer_mutex.
+ */
+static char readbuffer[PAGE_SIZE];
+static DEFINE_MUTEX(readbuffer_mutex);
+
+static int dasd_eer_open(struct inode *inp, struct file *filp)
+{
+	struct eerbuffer *eerb;
+	unsigned long flags;
+
+	eerb = kzalloc(sizeof(struct eerbuffer), GFP_KERNEL);
+	if (!eerb)
+		return -ENOMEM;
+	eerb->buffer_page_count = eer_pages;
+	if (eerb->buffer_page_count < 1 ||
+	    eerb->buffer_page_count > INT_MAX / PAGE_SIZE) {
+		kfree(eerb);
+		DBF_EVENT(DBF_WARNING, "can't open device since module "
+			"parameter eer_pages is smaller than 1 or"
+			" bigger than %d", (int)(INT_MAX / PAGE_SIZE));
+		return -EINVAL;
+	}
+	eerb->buffersize = eerb->buffer_page_count * PAGE_SIZE;
+	eerb->buffer = kmalloc_array(eerb->buffer_page_count, sizeof(char *),
+				     GFP_KERNEL);
+        if (!eerb->buffer) {
+		kfree(eerb);
+                return -ENOMEM;
+	}
+	if (dasd_eer_allocate_buffer_pages(eerb->buffer,
+					   eerb->buffer_page_count)) {
+		kfree(eerb->buffer);
+		kfree(eerb);
+		return -ENOMEM;
+	}
+	filp->private_data = eerb;
+	spin_lock_irqsave(&bufferlock, flags);
+	list_add(&eerb->list, &bufferlist);
+	spin_unlock_irqrestore(&bufferlock, flags);
+
+	return nonseekable_open(inp,filp);
+}
+
+static int dasd_eer_close(struct inode *inp, struct file *filp)
+{
+	struct eerbuffer *eerb;
+	unsigned long flags;
+
+	eerb = (struct eerbuffer *) filp->private_data;
+	spin_lock_irqsave(&bufferlock, flags);
+	list_del(&eerb->list);
+	spin_unlock_irqrestore(&bufferlock, flags);
+	dasd_eer_free_buffer_pages(eerb->buffer, eerb->buffer_page_count);
+	kfree(eerb->buffer);
+	kfree(eerb);
+
+	return 0;
+}
+
+static ssize_t dasd_eer_read(struct file *filp, char __user *buf,
+			     size_t count, loff_t *ppos)
+{
+	int tc,rc;
+	int tailcount,effective_count;
+        unsigned long flags;
+	struct eerbuffer *eerb;
+
+	eerb = (struct eerbuffer *) filp->private_data;
+	if (mutex_lock_interruptible(&readbuffer_mutex))
+		return -ERESTARTSYS;
+
+	spin_lock_irqsave(&bufferlock, flags);
+
+	if (eerb->residual < 0) { /* the remainder of this record */
+		                  /* has been deleted             */
+		eerb->residual = 0;
+		spin_unlock_irqrestore(&bufferlock, flags);
+		mutex_unlock(&readbuffer_mutex);
+		return -EIO;
+	} else if (eerb->residual > 0) {
+		/* OK we still have a second half of a record to deliver */
+		effective_count = min(eerb->residual, (int) count);
+		eerb->residual -= effective_count;
+	} else {
+		tc = 0;
+		while (!tc) {
+			tc = dasd_eer_read_buffer(eerb, (char *) &tailcount,
+						  sizeof(tailcount));
+			if (!tc) {
+				/* no data available */
+				spin_unlock_irqrestore(&bufferlock, flags);
+				mutex_unlock(&readbuffer_mutex);
+				if (filp->f_flags & O_NONBLOCK)
+					return -EAGAIN;
+				rc = wait_event_interruptible(
+					dasd_eer_read_wait_queue,
+					eerb->head != eerb->tail);
+				if (rc)
+					return rc;
+				if (mutex_lock_interruptible(&readbuffer_mutex))
+					return -ERESTARTSYS;
+				spin_lock_irqsave(&bufferlock, flags);
+			}
+		}
+		WARN_ON(tc != sizeof(tailcount));
+		effective_count = min(tailcount,(int)count);
+		eerb->residual = tailcount - effective_count;
+	}
+
+	tc = dasd_eer_read_buffer(eerb, readbuffer, effective_count);
+	WARN_ON(tc != effective_count);
+
+	spin_unlock_irqrestore(&bufferlock, flags);
+
+	if (copy_to_user(buf, readbuffer, effective_count)) {
+		mutex_unlock(&readbuffer_mutex);
+		return -EFAULT;
+	}
+
+	mutex_unlock(&readbuffer_mutex);
+	return effective_count;
+}
+
+static __poll_t dasd_eer_poll(struct file *filp, poll_table *ptable)
+{
+	__poll_t mask;
+	unsigned long flags;
+	struct eerbuffer *eerb;
+
+	eerb = (struct eerbuffer *) filp->private_data;
+	poll_wait(filp, &dasd_eer_read_wait_queue, ptable);
+	spin_lock_irqsave(&bufferlock, flags);
+	if (eerb->head != eerb->tail)
+		mask = EPOLLIN | EPOLLRDNORM ;
+	else
+		mask = 0;
+	spin_unlock_irqrestore(&bufferlock, flags);
+	return mask;
+}
+
+static const struct file_operations dasd_eer_fops = {
+	.open		= &dasd_eer_open,
+	.release	= &dasd_eer_close,
+	.read		= &dasd_eer_read,
+	.poll		= &dasd_eer_poll,
+	.owner		= THIS_MODULE,
+	.llseek		= noop_llseek,
+};
+
+static struct miscdevice *dasd_eer_dev = NULL;
+
+int __init dasd_eer_init(void)
+{
+	int rc;
+
+	dasd_eer_dev = kzalloc(sizeof(*dasd_eer_dev), GFP_KERNEL);
+	if (!dasd_eer_dev)
+		return -ENOMEM;
+
+	dasd_eer_dev->minor = MISC_DYNAMIC_MINOR;
+	dasd_eer_dev->name  = "dasd_eer";
+	dasd_eer_dev->fops  = &dasd_eer_fops;
+
+	rc = misc_register(dasd_eer_dev);
+	if (rc) {
+		kfree(dasd_eer_dev);
+		dasd_eer_dev = NULL;
+		DBF_EVENT(DBF_ERR, "%s", "dasd_eer_init could not "
+		       "register misc device");
+		return rc;
+	}
+
+	return 0;
+}
+
+void dasd_eer_exit(void)
+{
+	if (dasd_eer_dev) {
+		misc_deregister(dasd_eer_dev);
+		kfree(dasd_eer_dev);
+		dasd_eer_dev = NULL;
+	}
+}
diff --git a/drivers/s390/block/dasd_erp.c b/drivers/s390/block/dasd_erp.c
new file mode 100644
index 000000000..ba4fa372d
--- /dev/null
+++ b/drivers/s390/block/dasd_erp.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2001
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/ctype.h>
+#include <linux/init.h>
+
+#include <asm/debug.h>
+#include <asm/ebcdic.h>
+#include <linux/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_erp:"
+
+#include "dasd_int.h"
+
+struct dasd_ccw_req *
+dasd_alloc_erp_request(char *magic, int cplength, int datasize,
+		       struct dasd_device * device)
+{
+	unsigned long flags;
+	struct dasd_ccw_req *cqr;
+	char *data;
+	int size;
+
+	/* Sanity checks */
+	BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
+	     (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
+
+	size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
+	if (cplength > 0)
+		size += cplength * sizeof(struct ccw1);
+	if (datasize > 0)
+		size += datasize;
+	spin_lock_irqsave(&device->mem_lock, flags);
+	cqr = (struct dasd_ccw_req *)
+		dasd_alloc_chunk(&device->erp_chunks, size);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	if (cqr == NULL)
+		return ERR_PTR(-ENOMEM);
+	memset(cqr, 0, sizeof(struct dasd_ccw_req));
+	INIT_LIST_HEAD(&cqr->devlist);
+	INIT_LIST_HEAD(&cqr->blocklist);
+	data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
+	cqr->cpaddr = NULL;
+	if (cplength > 0) {
+		cqr->cpaddr = (struct ccw1 *) data;
+		data += cplength*sizeof(struct ccw1);
+		memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
+	}
+	cqr->data = NULL;
+	if (datasize > 0) {
+		cqr->data = data;
+ 		memset(cqr->data, 0, datasize);
+	}
+	strncpy((char *) &cqr->magic, magic, 4);
+	ASCEBC((char *) &cqr->magic, 4);
+	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	dasd_get_device(device);
+	return cqr;
+}
+
+void
+dasd_free_erp_request(struct dasd_ccw_req *cqr, struct dasd_device * device)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	dasd_free_chunk(&device->erp_chunks, cqr);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	atomic_dec(&device->ref_count);
+}
+
+
+/*
+ * dasd_default_erp_action just retries the current cqr
+ */
+struct dasd_ccw_req *
+dasd_default_erp_action(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+
+	device = cqr->startdev;
+
+        /* just retry - there is nothing to save ... I got no sense data.... */
+        if (cqr->retries > 0) {
+		DBF_DEV_EVENT(DBF_DEBUG, device,
+                             "default ERP called (%i retries left)",
+                             cqr->retries);
+		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
+			cqr->lpm = dasd_path_get_opm(device);
+		cqr->status = DASD_CQR_FILLED;
+        } else {
+		pr_err("%s: default ERP has run out of retries and failed\n",
+		       dev_name(&device->cdev->dev));
+		cqr->status = DASD_CQR_FAILED;
+		cqr->stopclk = get_tod_clock();
+        }
+        return cqr;
+}				/* end dasd_default_erp_action */
+
+/*
+ * DESCRIPTION
+ *   Frees all ERPs of the current ERP Chain and set the status
+ *   of the original CQR either to DASD_CQR_DONE if ERP was successful
+ *   or to DASD_CQR_FAILED if ERP was NOT successful.
+ *   NOTE: This function is only called if no discipline postaction
+ *	   is available
+ *
+ * PARAMETER
+ *   erp		current erp_head
+ *
+ * RETURN VALUES
+ *   cqr		pointer to the original CQR
+ */
+struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *cqr)
+{
+	int success;
+	unsigned long startclk, stopclk;
+	struct dasd_device *startdev;
+
+	BUG_ON(cqr->refers == NULL || cqr->function == NULL);
+
+	success = cqr->status == DASD_CQR_DONE;
+	startclk = cqr->startclk;
+	stopclk = cqr->stopclk;
+	startdev = cqr->startdev;
+
+	/* free all ERPs - but NOT the original cqr */
+	while (cqr->refers != NULL) {
+		struct dasd_ccw_req *refers;
+
+		refers = cqr->refers;
+		/* remove the request from the block queue */
+		list_del(&cqr->blocklist);
+		/* free the finished erp request */
+		dasd_free_erp_request(cqr, cqr->memdev);
+		cqr = refers;
+	}
+
+	/* set corresponding status to original cqr */
+	cqr->startclk = startclk;
+	cqr->stopclk = stopclk;
+	cqr->startdev = startdev;
+	if (success)
+		cqr->status = DASD_CQR_DONE;
+	else {
+		cqr->status = DASD_CQR_FAILED;
+		cqr->stopclk = get_tod_clock();
+	}
+
+	return cqr;
+
+}				/* end default_erp_postaction */
+
+void
+dasd_log_sense(struct dasd_ccw_req *cqr, struct irb *irb)
+{
+	struct dasd_device *device;
+
+	device = cqr->startdev;
+	if (cqr->intrc == -ETIMEDOUT) {
+		dev_err(&device->cdev->dev,
+			"A timeout error occurred for cqr %p\n", cqr);
+		return;
+	}
+	if (cqr->intrc == -ENOLINK) {
+		dev_err(&device->cdev->dev,
+			"A transport error occurred for cqr %p\n", cqr);
+		return;
+	}
+	/* dump sense data */
+	if (device->discipline && device->discipline->dump_sense)
+		device->discipline->dump_sense(device, cqr, irb);
+}
+
+void
+dasd_log_sense_dbf(struct dasd_ccw_req *cqr, struct irb *irb)
+{
+	struct dasd_device *device;
+
+	device = cqr->startdev;
+	/* dump sense data to s390 debugfeature*/
+	if (device->discipline && device->discipline->dump_sense_dbf)
+		device->discipline->dump_sense_dbf(device, irb, "log");
+}
+EXPORT_SYMBOL(dasd_log_sense_dbf);
+
+EXPORT_SYMBOL(dasd_default_erp_action);
+EXPORT_SYMBOL(dasd_default_erp_postaction);
+EXPORT_SYMBOL(dasd_alloc_erp_request);
+EXPORT_SYMBOL(dasd_free_erp_request);
+EXPORT_SYMBOL(dasd_log_sense);
+
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
new file mode 100644
index 000000000..fab09455b
--- /dev/null
+++ b/drivers/s390/block/dasd_fba.c
@@ -0,0 +1,835 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ */
+
+#define KMSG_COMPONENT "dasd-fba"
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <asm/debug.h>
+
+#include <linux/slab.h>
+#include <linux/hdreg.h>	/* HDIO_GETGEO			    */
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <asm/idals.h>
+#include <asm/ebcdic.h>
+#include <asm/io.h>
+#include <asm/ccwdev.h>
+
+#include "dasd_int.h"
+#include "dasd_fba.h"
+
+#ifdef PRINTK_HEADER
+#undef PRINTK_HEADER
+#endif				/* PRINTK_HEADER */
+#define PRINTK_HEADER "dasd(fba):"
+
+#define FBA_DEFAULT_RETRIES 32
+
+#define DASD_FBA_CCW_WRITE 0x41
+#define DASD_FBA_CCW_READ 0x42
+#define DASD_FBA_CCW_LOCATE 0x43
+#define DASD_FBA_CCW_DEFINE_EXTENT 0x63
+
+MODULE_LICENSE("GPL");
+
+static struct dasd_discipline dasd_fba_discipline;
+static void *dasd_fba_zero_page;
+
+struct dasd_fba_private {
+	struct dasd_fba_characteristics rdc_data;
+};
+
+static struct ccw_device_id dasd_fba_ids[] = {
+	{ CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
+	{ CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
+	{ /* end of list */ },
+};
+
+MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);
+
+static struct ccw_driver dasd_fba_driver; /* see below */
+static int
+dasd_fba_probe(struct ccw_device *cdev)
+{
+	return dasd_generic_probe(cdev, &dasd_fba_discipline);
+}
+
+static int
+dasd_fba_set_online(struct ccw_device *cdev)
+{
+	return dasd_generic_set_online(cdev, &dasd_fba_discipline);
+}
+
+static struct ccw_driver dasd_fba_driver = {
+	.driver = {
+		.name	= "dasd-fba",
+		.owner	= THIS_MODULE,
+	},
+	.ids         = dasd_fba_ids,
+	.probe       = dasd_fba_probe,
+	.remove      = dasd_generic_remove,
+	.set_offline = dasd_generic_set_offline,
+	.set_online  = dasd_fba_set_online,
+	.notify      = dasd_generic_notify,
+	.path_event  = dasd_generic_path_event,
+	.freeze      = dasd_generic_pm_freeze,
+	.thaw	     = dasd_generic_restore_device,
+	.restore     = dasd_generic_restore_device,
+	.int_class   = IRQIO_DAS,
+};
+
+static void
+define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
+	      int blksize, int beg, int nr)
+{
+	ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
+	ccw->flags = 0;
+	ccw->count = 16;
+	ccw->cda = (__u32) __pa(data);
+	memset(data, 0, sizeof (struct DE_fba_data));
+	if (rw == WRITE)
+		(data->mask).perm = 0x0;
+	else if (rw == READ)
+		(data->mask).perm = 0x1;
+	else
+		data->mask.perm = 0x2;
+	data->blk_size = blksize;
+	data->ext_loc = beg;
+	data->ext_end = nr - 1;
+}
+
+static void
+locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
+	      int block_nr, int block_ct)
+{
+	ccw->cmd_code = DASD_FBA_CCW_LOCATE;
+	ccw->flags = 0;
+	ccw->count = 8;
+	ccw->cda = (__u32) __pa(data);
+	memset(data, 0, sizeof (struct LO_fba_data));
+	if (rw == WRITE)
+		data->operation.cmd = 0x5;
+	else if (rw == READ)
+		data->operation.cmd = 0x6;
+	else
+		data->operation.cmd = 0x8;
+	data->blk_nr = block_nr;
+	data->blk_ct = block_ct;
+}
+
+static int
+dasd_fba_check_characteristics(struct dasd_device *device)
+{
+	struct dasd_fba_private *private = device->private;
+	struct ccw_device *cdev = device->cdev;
+	struct dasd_block *block;
+	int readonly, rc;
+
+	if (!private) {
+		private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
+		if (!private) {
+			dev_warn(&device->cdev->dev,
+				 "Allocating memory for private DASD "
+				 "data failed\n");
+			return -ENOMEM;
+		}
+		device->private = private;
+	} else {
+		memset(private, 0, sizeof(*private));
+	}
+	block = dasd_alloc_block();
+	if (IS_ERR(block)) {
+		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s", "could not allocate "
+				"dasd block structure");
+		device->private = NULL;
+		kfree(private);
+		return PTR_ERR(block);
+	}
+	device->block = block;
+	block->base = device;
+
+	/* Read Device Characteristics */
+	rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
+					 &private->rdc_data, 32);
+	if (rc) {
+		DBF_EVENT_DEVID(DBF_WARNING, cdev, "Read device "
+				"characteristics returned error %d", rc);
+		device->block = NULL;
+		dasd_free_block(block);
+		device->private = NULL;
+		kfree(private);
+		return rc;
+	}
+
+	device->default_expires = DASD_EXPIRES;
+	device->default_retries = FBA_DEFAULT_RETRIES;
+	dasd_path_set_opm(device, LPM_ANYPATH);
+
+	readonly = dasd_device_is_ro(device);
+	if (readonly)
+		set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+
+	/* FBA supports discard, set the according feature bit */
+	dasd_set_feature(cdev, DASD_FEATURE_DISCARD, 1);
+
+	dev_info(&device->cdev->dev,
+		 "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
+		 "and %d B/blk%s\n",
+		 cdev->id.dev_type,
+		 cdev->id.dev_model,
+		 cdev->id.cu_type,
+		 cdev->id.cu_model,
+		 ((private->rdc_data.blk_bdsa *
+		   (private->rdc_data.blk_size >> 9)) >> 11),
+		 private->rdc_data.blk_size,
+		 readonly ? ", read-only device" : "");
+	return 0;
+}
+
+static int dasd_fba_do_analysis(struct dasd_block *block)
+{
+	struct dasd_fba_private *private = block->base->private;
+	int sb, rc;
+
+	rc = dasd_check_blocksize(private->rdc_data.blk_size);
+	if (rc) {
+		DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
+			    private->rdc_data.blk_size);
+		return rc;
+	}
+	block->blocks = private->rdc_data.blk_bdsa;
+	block->bp_block = private->rdc_data.blk_size;
+	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
+	for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
+		block->s2b_shift++;
+	return 0;
+}
+
+static int dasd_fba_fill_geometry(struct dasd_block *block,
+				  struct hd_geometry *geo)
+{
+	if (dasd_check_blocksize(block->bp_block) != 0)
+		return -EINVAL;
+	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
+	geo->heads = 16;
+	geo->sectors = 128 >> block->s2b_shift;
+	return 0;
+}
+
+static dasd_erp_fn_t
+dasd_fba_erp_action(struct dasd_ccw_req * cqr)
+{
+	return dasd_default_erp_action;
+}
+
+static dasd_erp_fn_t
+dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
+{
+	if (cqr->function == dasd_default_erp_action)
+		return dasd_default_erp_postaction;
+
+	DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
+		    cqr->function);
+	return NULL;
+}
+
+static void dasd_fba_check_for_device_change(struct dasd_device *device,
+					     struct dasd_ccw_req *cqr,
+					     struct irb *irb)
+{
+	char mask;
+
+	/* first of all check for state change pending interrupt */
+	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
+	if ((irb->scsw.cmd.dstat & mask) == mask)
+		dasd_generic_handle_state_change(device);
+};
+
+
+/*
+ * Builds a CCW with no data payload
+ */
+static void ccw_write_no_data(struct ccw1 *ccw)
+{
+	ccw->cmd_code = DASD_FBA_CCW_WRITE;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = 0;
+}
+
+/*
+ * Builds a CCW that writes only zeroes.
+ */
+static void ccw_write_zero(struct ccw1 *ccw, int count)
+{
+	ccw->cmd_code = DASD_FBA_CCW_WRITE;
+	ccw->flags |= CCW_FLAG_SLI;
+	ccw->count = count;
+	ccw->cda = (__u32) (addr_t) dasd_fba_zero_page;
+}
+
+/*
+ * Helper function to count the amount of necessary CCWs within a given range
+ * with 4k alignment and command chaining in mind.
+ */
+static int count_ccws(sector_t first_rec, sector_t last_rec,
+		      unsigned int blocks_per_page)
+{
+	sector_t wz_stop = 0, d_stop = 0;
+	int cur_pos = 0;
+	int count = 0;
+
+	if (first_rec % blocks_per_page != 0) {
+		wz_stop = first_rec + blocks_per_page -
+			(first_rec % blocks_per_page) - 1;
+		if (wz_stop > last_rec)
+			wz_stop = last_rec;
+		cur_pos = wz_stop - first_rec + 1;
+		count++;
+	}
+
+	if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) {
+		if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0)
+			d_stop = last_rec - ((last_rec - blocks_per_page + 1) %
+					     blocks_per_page);
+		else
+			d_stop = last_rec;
+
+		cur_pos += d_stop - (first_rec + cur_pos) + 1;
+		count++;
+	}
+
+	if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec)
+		count++;
+
+	return count;
+}
+
+/*
+ * This function builds a CCW request for block layer discard requests.
+ * Each page in the z/VM hypervisor that represents certain records of an FBA
+ * device will be padded with zeros. This is a special behaviour of the WRITE
+ * command which is triggered when no data payload is added to the CCW.
+ *
+ * Note: Due to issues in some z/VM versions, we can't fully utilise this
+ * special behaviour. We have to keep a 4k (or 8 block) alignment in mind to
+ * work around those issues and write actual zeroes to the unaligned parts in
+ * the request. This workaround might be removed in the future.
+ */
+static struct dasd_ccw_req *dasd_fba_build_cp_discard(
+						struct dasd_device *memdev,
+						struct dasd_block *block,
+						struct request *req)
+{
+	struct LO_fba_data *LO_data;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+
+	sector_t wz_stop = 0, d_stop = 0;
+	sector_t first_rec, last_rec;
+
+	unsigned int blksize = block->bp_block;
+	unsigned int blocks_per_page;
+	int wz_count = 0;
+	int d_count = 0;
+	int cur_pos = 0; /* Current position within the extent */
+	int count = 0;
+	int cplength;
+	int datasize;
+	int nr_ccws;
+
+	first_rec = blk_rq_pos(req) >> block->s2b_shift;
+	last_rec =
+		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
+	count = last_rec - first_rec + 1;
+
+	blocks_per_page = BLOCKS_PER_PAGE(blksize);
+	nr_ccws = count_ccws(first_rec, last_rec, blocks_per_page);
+
+	/* define extent + nr_ccws * locate record + nr_ccws * single CCW */
+	cplength = 1 + 2 * nr_ccws;
+	datasize = sizeof(struct DE_fba_data) +
+		nr_ccws * (sizeof(struct LO_fba_data) + sizeof(struct ccw1));
+
+	cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
+				   blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+
+	ccw = cqr->cpaddr;
+
+	define_extent(ccw++, cqr->data, WRITE, blksize, first_rec, count);
+	LO_data = cqr->data + sizeof(struct DE_fba_data);
+
+	/* First part is not aligned. Calculate range to write zeroes. */
+	if (first_rec % blocks_per_page != 0) {
+		wz_stop = first_rec + blocks_per_page -
+			(first_rec % blocks_per_page) - 1;
+		if (wz_stop > last_rec)
+			wz_stop = last_rec;
+		wz_count = wz_stop - first_rec + 1;
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count);
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw_write_zero(ccw++, wz_count * blksize);
+
+		cur_pos = wz_count;
+	}
+
+	/* We can do proper discard when we've got at least blocks_per_page blocks. */
+	if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) {
+		/* is last record at page boundary? */
+		if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0)
+			d_stop = last_rec - ((last_rec - blocks_per_page + 1) %
+					     blocks_per_page);
+		else
+			d_stop = last_rec;
+
+		d_count = d_stop - (first_rec + cur_pos) + 1;
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, LO_data++, WRITE, cur_pos, d_count);
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw_write_no_data(ccw++);
+
+		cur_pos += d_count;
+	}
+
+	/* We might still have some bits left which need to be zeroed. */
+	if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec) {
+		if (d_stop != 0)
+			wz_count = last_rec - d_stop;
+		else if (wz_stop != 0)
+			wz_count = last_rec - wz_stop;
+		else
+			wz_count = count;
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count);
+
+		ccw[-1].flags |= CCW_FLAG_CC;
+		ccw_write_zero(ccw++, wz_count * blksize);
+	}
+
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+
+	cqr->startdev = memdev;
+	cqr->memdev = memdev;
+	cqr->block = block;
+	cqr->expires = memdev->default_expires * HZ;	/* default 5 minutes */
+	cqr->retries = memdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	return cqr;
+}
+
+static struct dasd_ccw_req *dasd_fba_build_cp_regular(
+						struct dasd_device *memdev,
+						struct dasd_block *block,
+						struct request *req)
+{
+	struct dasd_fba_private *private = block->base->private;
+	unsigned long *idaws;
+	struct LO_fba_data *LO_data;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst;
+	int count, cidaw, cplength, datasize;
+	sector_t recid, first_rec, last_rec;
+	unsigned int blksize, off;
+	unsigned char cmd;
+
+	if (rq_data_dir(req) == READ) {
+		cmd = DASD_FBA_CCW_READ;
+	} else if (rq_data_dir(req) == WRITE) {
+		cmd = DASD_FBA_CCW_WRITE;
+	} else
+		return ERR_PTR(-EINVAL);
+	blksize = block->bp_block;
+	/* Calculate record id of first and last block. */
+	first_rec = blk_rq_pos(req) >> block->s2b_shift;
+	last_rec =
+		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
+	/* Check struct bio and count the number of blocks for the request. */
+	count = 0;
+	cidaw = 0;
+	rq_for_each_segment(bv, req, iter) {
+		if (bv.bv_len & (blksize - 1))
+			/* Fba can only do full blocks. */
+			return ERR_PTR(-EINVAL);
+		count += bv.bv_len >> (block->s2b_shift + 9);
+		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
+			cidaw += bv.bv_len / blksize;
+	}
+	/* Paranoia. */
+	if (count != last_rec - first_rec + 1)
+		return ERR_PTR(-EINVAL);
+	/* 1x define extent + 1x locate record + number of blocks */
+	cplength = 2 + count;
+	/* 1x define extent + 1x locate record */
+	datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
+		cidaw * sizeof(unsigned long);
+	/*
+	 * Find out number of additional locate record ccws if the device
+	 * can't do data chaining.
+	 */
+	if (private->rdc_data.mode.bits.data_chain == 0) {
+		cplength += count - 1;
+		datasize += (count - 1)*sizeof(struct LO_fba_data);
+	}
+	/* Allocate the ccw request. */
+	cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
+				   blk_mq_rq_to_pdu(req));
+	if (IS_ERR(cqr))
+		return cqr;
+	ccw = cqr->cpaddr;
+	/* First ccw is define extent. */
+	define_extent(ccw++, cqr->data, rq_data_dir(req),
+		      block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
+	/* Build locate_record + read/write ccws. */
+	idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
+	LO_data = (struct LO_fba_data *) (idaws + cidaw);
+	/* Locate record for all blocks for smart devices. */
+	if (private->rdc_data.mode.bits.data_chain != 0) {
+		ccw[-1].flags |= CCW_FLAG_CC;
+		locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
+	}
+	recid = first_rec;
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		if (dasd_page_cache) {
+			char *copy = kmem_cache_alloc(dasd_page_cache,
+						      GFP_DMA | __GFP_NOWARN);
+			if (copy && rq_data_dir(req) == WRITE)
+				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
+			if (copy)
+				dst = copy + bv.bv_offset;
+		}
+		for (off = 0; off < bv.bv_len; off += blksize) {
+			/* Locate record for stupid devices. */
+			if (private->rdc_data.mode.bits.data_chain == 0) {
+				ccw[-1].flags |= CCW_FLAG_CC;
+				locate_record(ccw, LO_data++,
+					      rq_data_dir(req),
+					      recid - first_rec, 1);
+				ccw->flags = CCW_FLAG_CC;
+				ccw++;
+			} else {
+				if (recid > first_rec)
+					ccw[-1].flags |= CCW_FLAG_DC;
+				else
+					ccw[-1].flags |= CCW_FLAG_CC;
+			}
+			ccw->cmd_code = cmd;
+			ccw->count = block->bp_block;
+			if (idal_is_needed(dst, blksize)) {
+				ccw->cda = (__u32)(addr_t) idaws;
+				ccw->flags = CCW_FLAG_IDA;
+				idaws = idal_create_words(idaws, dst, blksize);
+			} else {
+				ccw->cda = (__u32)(addr_t) dst;
+				ccw->flags = 0;
+			}
+			ccw++;
+			dst += blksize;
+			recid++;
+		}
+	}
+	if (blk_noretry_request(req) ||
+	    block->base->features & DASD_FEATURE_FAILFAST)
+		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+	cqr->startdev = memdev;
+	cqr->memdev = memdev;
+	cqr->block = block;
+	cqr->expires = memdev->default_expires * HZ;	/* default 5 minutes */
+	cqr->retries = memdev->default_retries;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device *memdev,
+					      struct dasd_block *block,
+					      struct request *req)
+{
+	if (req_op(req) == REQ_OP_DISCARD || req_op(req) == REQ_OP_WRITE_ZEROES)
+		return dasd_fba_build_cp_discard(memdev, block, req);
+	else
+		return dasd_fba_build_cp_regular(memdev, block, req);
+}
+
+static int
+dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
+{
+	struct dasd_fba_private *private = cqr->block->base->private;
+	struct ccw1 *ccw;
+	struct req_iterator iter;
+	struct bio_vec bv;
+	char *dst, *cda;
+	unsigned int blksize, off;
+	int status;
+
+	if (!dasd_page_cache)
+		goto out;
+	blksize = cqr->block->bp_block;
+	ccw = cqr->cpaddr;
+	/* Skip over define extent & locate record. */
+	ccw++;
+	if (private->rdc_data.mode.bits.data_chain != 0)
+		ccw++;
+	rq_for_each_segment(bv, req, iter) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
+			/* Skip locate record. */
+			if (private->rdc_data.mode.bits.data_chain == 0)
+				ccw++;
+			if (dst) {
+				if (ccw->flags & CCW_FLAG_IDA)
+					cda = *((char **)((addr_t) ccw->cda));
+				else
+					cda = (char *)((addr_t) ccw->cda);
+				if (dst != cda) {
+					if (rq_data_dir(req) == READ)
+						memcpy(dst, cda, bv.bv_len);
+					kmem_cache_free(dasd_page_cache,
+					    (void *)((addr_t)cda & PAGE_MASK));
+				}
+				dst = NULL;
+			}
+			ccw++;
+		}
+	}
+out:
+	status = cqr->status == DASD_CQR_DONE;
+	dasd_sfree_request(cqr, cqr->memdev);
+	return status;
+}
+
+static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
+{
+	if (cqr->retries < 0)
+		cqr->status = DASD_CQR_FAILED;
+	else
+		cqr->status = DASD_CQR_FILLED;
+};
+
+static int
+dasd_fba_fill_info(struct dasd_device * device,
+		   struct dasd_information2_t * info)
+{
+	struct dasd_fba_private *private = device->private;
+
+	info->label_block = 1;
+	info->FBA_layout = 1;
+	info->format = DASD_FORMAT_LDL;
+	info->characteristics_size = sizeof(private->rdc_data);
+	memcpy(info->characteristics, &private->rdc_data,
+	       sizeof(private->rdc_data));
+	info->confdata_size = 0;
+	return 0;
+}
+
+static void
+dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
+			char *reason)
+{
+	u64 *sense;
+
+	sense = (u64 *) dasd_get_sense(irb);
+	if (sense) {
+		DBF_DEV_EVENT(DBF_EMERG, device,
+			      "%s: %s %02x%02x%02x %016llx %016llx %016llx "
+			      "%016llx", reason,
+			      scsw_is_tm(&irb->scsw) ? "t" : "c",
+			      scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
+			      scsw_dstat(&irb->scsw), sense[0], sense[1],
+			      sense[2], sense[3]);
+	} else {
+		DBF_DEV_EVENT(DBF_EMERG, device, "%s",
+			      "SORRY - NO VALID SENSE AVAILABLE\n");
+	}
+}
+
+
+static void
+dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
+		    struct irb *irb)
+{
+	char *page;
+	struct ccw1 *act, *end, *last;
+	int len, sl, sct, count;
+
+	page = (char *) get_zeroed_page(GFP_ATOMIC);
+	if (page == NULL) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "No memory to dump sense data");
+		return;
+	}
+	len = sprintf(page, PRINTK_HEADER
+		      " I/O status report for device %s:\n",
+		      dev_name(&device->cdev->dev));
+	len += sprintf(page + len, PRINTK_HEADER
+		       " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
+		       irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
+	len += sprintf(page + len, PRINTK_HEADER
+		       " device %s: Failing CCW: %p\n",
+		       dev_name(&device->cdev->dev),
+		       (void *) (addr_t) irb->scsw.cmd.cpa);
+	if (irb->esw.esw0.erw.cons) {
+		for (sl = 0; sl < 4; sl++) {
+			len += sprintf(page + len, PRINTK_HEADER
+				       " Sense(hex) %2d-%2d:",
+				       (8 * sl), ((8 * sl) + 7));
+
+			for (sct = 0; sct < 8; sct++) {
+				len += sprintf(page + len, " %02x",
+					       irb->ecw[8 * sl + sct]);
+			}
+			len += sprintf(page + len, "\n");
+		}
+	} else {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " SORRY - NO VALID SENSE AVAILABLE\n");
+	}
+	printk(KERN_ERR "%s", page);
+
+	/* dump the Channel Program */
+	/* print first CCWs (maximum 8) */
+	act = req->cpaddr;
+        for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
+	end = min(act + 8, last);
+	len = sprintf(page, PRINTK_HEADER " Related CP in req: %p\n", req);
+	while (act <= end) {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " CCW %p: %08X %08X DAT:",
+			       act, ((int *) act)[0], ((int *) act)[1]);
+		for (count = 0; count < 32 && count < act->count;
+		     count += sizeof(int))
+			len += sprintf(page + len, " %08X",
+				       ((int *) (addr_t) act->cda)
+				       [(count>>2)]);
+		len += sprintf(page + len, "\n");
+		act++;
+	}
+	printk(KERN_ERR "%s", page);
+
+
+	/* print failing CCW area */
+	len = 0;
+	if (act <  ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
+		act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
+		len += sprintf(page + len, PRINTK_HEADER "......\n");
+	}
+	end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
+	while (act <= end) {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " CCW %p: %08X %08X DAT:",
+			       act, ((int *) act)[0], ((int *) act)[1]);
+		for (count = 0; count < 32 && count < act->count;
+		     count += sizeof(int))
+			len += sprintf(page + len, " %08X",
+				       ((int *) (addr_t) act->cda)
+				       [(count>>2)]);
+		len += sprintf(page + len, "\n");
+		act++;
+	}
+
+	/* print last CCWs */
+	if (act <  last - 2) {
+		act = last - 2;
+		len += sprintf(page + len, PRINTK_HEADER "......\n");
+	}
+	while (act <= last) {
+		len += sprintf(page + len, PRINTK_HEADER
+			       " CCW %p: %08X %08X DAT:",
+			       act, ((int *) act)[0], ((int *) act)[1]);
+		for (count = 0; count < 32 && count < act->count;
+		     count += sizeof(int))
+			len += sprintf(page + len, " %08X",
+				       ((int *) (addr_t) act->cda)
+				       [(count>>2)]);
+		len += sprintf(page + len, "\n");
+		act++;
+	}
+	if (len > 0)
+		printk(KERN_ERR "%s", page);
+	free_page((unsigned long) page);
+}
+
+/*
+ * max_blocks is dependent on the amount of storage that is available
+ * in the static io buffer for each device. Currently each device has
+ * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
+ * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
+ * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
+ * addition we have one define extent ccw + 16 bytes of data and a
+ * locate record ccw for each block (stupid devices!) + 16 bytes of data.
+ * That makes:
+ * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
+ * We want to fit two into the available memory so that we can immediately
+ * start the next request if one finishes off. That makes 100.1 blocks
+ * for one request. Give a little safety and the result is 96.
+ */
+static struct dasd_discipline dasd_fba_discipline = {
+	.owner = THIS_MODULE,
+	.name = "FBA ",
+	.ebcname = "FBA ",
+	.max_blocks = 96,
+	.check_device = dasd_fba_check_characteristics,
+	.do_analysis = dasd_fba_do_analysis,
+	.verify_path = dasd_generic_verify_path,
+	.fill_geometry = dasd_fba_fill_geometry,
+	.start_IO = dasd_start_IO,
+	.term_IO = dasd_term_IO,
+	.handle_terminated_request = dasd_fba_handle_terminated_request,
+	.erp_action = dasd_fba_erp_action,
+	.erp_postaction = dasd_fba_erp_postaction,
+	.check_for_device_change = dasd_fba_check_for_device_change,
+	.build_cp = dasd_fba_build_cp,
+	.free_cp = dasd_fba_free_cp,
+	.dump_sense = dasd_fba_dump_sense,
+	.dump_sense_dbf = dasd_fba_dump_sense_dbf,
+	.fill_info = dasd_fba_fill_info,
+};
+
+static int __init
+dasd_fba_init(void)
+{
+	int ret;
+
+	ASCEBC(dasd_fba_discipline.ebcname, 4);
+
+	dasd_fba_zero_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!dasd_fba_zero_page)
+		return -ENOMEM;
+
+	ret = ccw_driver_register(&dasd_fba_driver);
+	if (!ret)
+		wait_for_device_probe();
+
+	return ret;
+}
+
+static void __exit
+dasd_fba_cleanup(void)
+{
+	ccw_driver_unregister(&dasd_fba_driver);
+	free_page((unsigned long)dasd_fba_zero_page);
+}
+
+module_init(dasd_fba_init);
+module_exit(dasd_fba_cleanup);
diff --git a/drivers/s390/block/dasd_fba.h b/drivers/s390/block/dasd_fba.h
new file mode 100644
index 000000000..b14bf1b2c
--- /dev/null
+++ b/drivers/s390/block/dasd_fba.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Coypright IBM Corp. 1999, 2000
+ *
+ */
+
+#ifndef DASD_FBA_H
+#define DASD_FBA_H
+
+struct DE_fba_data {
+	struct {
+		unsigned char perm:2;	/* Permissions on this extent */
+		unsigned char zero:2;	/* Must be zero */
+		unsigned char da:1;	/* usually zero */
+		unsigned char diag:1;	/* allow diagnose */
+		unsigned char zero2:2;	/* zero */
+	} __attribute__ ((packed)) mask;
+	__u8 zero;		/* Must be zero */
+	__u16 blk_size;		/* Blocksize */
+	__u32 ext_loc;		/* Extent locator */
+	__u32 ext_beg;		/* logical number of block 0 in extent */
+	__u32 ext_end;		/* logocal number of last block in extent */
+} __attribute__ ((packed));
+
+struct LO_fba_data {
+	struct {
+		unsigned char zero:4;
+		unsigned char cmd:4;
+	} __attribute__ ((packed)) operation;
+	__u8 auxiliary;
+	__u16 blk_ct;
+	__u32 blk_nr;
+} __attribute__ ((packed));
+
+struct dasd_fba_characteristics {
+	union {
+		__u8 c;
+		struct {
+			unsigned char reserved:1;
+			unsigned char overrunnable:1;
+			unsigned char burst_byte:1;
+			unsigned char data_chain:1;
+			unsigned char zeros:4;
+		} __attribute__ ((packed)) bits;
+	} __attribute__ ((packed)) mode;
+	union {
+		__u8 c;
+		struct {
+			unsigned char zero0:1;
+			unsigned char removable:1;
+			unsigned char shared:1;
+			unsigned char zero1:1;
+			unsigned char mam:1;
+			unsigned char zeros:3;
+		} __attribute__ ((packed)) bits;
+	} __attribute__ ((packed)) features;
+	__u8 dev_class;
+	__u8 unit_type;
+	__u16 blk_size;
+	__u32 blk_per_cycl;
+	__u32 blk_per_bound;
+	__u32 blk_bdsa;
+	__u32 reserved0;
+	__u16 reserved1;
+	__u16 blk_ce;
+	__u32 reserved2;
+	__u16 reserved3;
+} __attribute__ ((packed));
+
+#endif				/* DASD_FBA_H */
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
new file mode 100644
index 000000000..5542d9ead
--- /dev/null
+++ b/drivers/s390/block/dasd_genhd.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2001
+ *
+ * gendisk related functions for the dasd driver.
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/blkpg.h>
+
+#include <linux/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_gendisk:"
+
+#include "dasd_int.h"
+
+/*
+ * Allocate and register gendisk structure for device.
+ */
+int dasd_gendisk_alloc(struct dasd_block *block)
+{
+	struct gendisk *gdp;
+	struct dasd_device *base;
+	int len;
+
+	/* Make sure the minor for this device exists. */
+	base = block->base;
+	if (base->devindex >= DASD_PER_MAJOR)
+		return -EBUSY;
+
+	gdp = alloc_disk(1 << DASD_PARTN_BITS);
+	if (!gdp)
+		return -ENOMEM;
+
+	/* Initialize gendisk structure. */
+	gdp->major = DASD_MAJOR;
+	gdp->first_minor = base->devindex << DASD_PARTN_BITS;
+	gdp->fops = &dasd_device_operations;
+
+	/*
+	 * Set device name.
+	 *   dasda - dasdz : 26 devices
+	 *   dasdaa - dasdzz : 676 devices, added up = 702
+	 *   dasdaaa - dasdzzz : 17576 devices, added up = 18278
+	 *   dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
+	 */
+	len = sprintf(gdp->disk_name, "dasd");
+	if (base->devindex > 25) {
+		if (base->devindex > 701) {
+			if (base->devindex > 18277)
+			        len += sprintf(gdp->disk_name + len, "%c",
+					       'a'+(((base->devindex-18278)
+						     /17576)%26));
+			len += sprintf(gdp->disk_name + len, "%c",
+				       'a'+(((base->devindex-702)/676)%26));
+		}
+		len += sprintf(gdp->disk_name + len, "%c",
+			       'a'+(((base->devindex-26)/26)%26));
+	}
+	len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
+
+	if (base->features & DASD_FEATURE_READONLY ||
+	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
+		set_disk_ro(gdp, 1);
+	dasd_add_link_to_gendisk(gdp, base);
+	gdp->queue = block->request_queue;
+	block->gdp = gdp;
+	set_capacity(block->gdp, 0);
+	device_add_disk(&base->cdev->dev, block->gdp, NULL);
+	return 0;
+}
+
+/*
+ * Unregister and free gendisk structure for device.
+ */
+void dasd_gendisk_free(struct dasd_block *block)
+{
+	if (block->gdp) {
+		del_gendisk(block->gdp);
+		block->gdp->private_data = NULL;
+		put_disk(block->gdp);
+		block->gdp = NULL;
+	}
+}
+
+/*
+ * Trigger a partition detection.
+ */
+int dasd_scan_partitions(struct dasd_block *block)
+{
+	struct block_device *bdev;
+	int rc;
+
+	bdev = bdget_disk(block->gdp, 0);
+	if (!bdev) {
+		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
+			      "scan partitions error, bdget returned NULL");
+		return -ENODEV;
+	}
+
+	rc = blkdev_get(bdev, FMODE_READ, NULL);
+	if (rc < 0) {
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+			      "scan partitions error, blkdev_get returned %d",
+			      rc);
+		return -ENODEV;
+	}
+
+	rc = blkdev_reread_part(bdev);
+	if (rc)
+		DBF_DEV_EVENT(DBF_ERR, block->base,
+				"scan partitions error, rc %d", rc);
+
+	/*
+	 * Since the matching blkdev_put call to the blkdev_get in
+	 * this function is not called before dasd_destroy_partitions
+	 * the offline open_count limit needs to be increased from
+	 * 0 to 1. This is done by setting device->bdev (see
+	 * dasd_generic_set_offline). As long as the partition
+	 * detection is running no offline should be allowed. That
+	 * is why the assignment to device->bdev is done AFTER
+	 * the BLKRRPART ioctl.
+	 */
+	block->bdev = bdev;
+	return 0;
+}
+
+/*
+ * Remove all inodes in the system for a device, delete the
+ * partitions and make device unusable by setting its size to zero.
+ */
+void dasd_destroy_partitions(struct dasd_block *block)
+{
+	/* The two structs have 168/176 byte on 31/64 bit. */
+	struct blkpg_partition bpart;
+	struct blkpg_ioctl_arg barg;
+	struct block_device *bdev;
+
+	/*
+	 * Get the bdev pointer from the device structure and clear
+	 * device->bdev to lower the offline open_count limit again.
+	 */
+	bdev = block->bdev;
+	block->bdev = NULL;
+
+	/*
+	 * See fs/partition/check.c:delete_partition
+	 * Can't call delete_partitions directly. Use ioctl.
+	 * The ioctl also does locking and invalidation.
+	 */
+	memset(&bpart, 0, sizeof(struct blkpg_partition));
+	memset(&barg, 0, sizeof(struct blkpg_ioctl_arg));
+	barg.data = (void __force __user *) &bpart;
+	barg.op = BLKPG_DEL_PARTITION;
+	for (bpart.pno = block->gdp->minors - 1; bpart.pno > 0; bpart.pno--)
+		ioctl_by_bdev(bdev, BLKPG, (unsigned long) &barg);
+
+	invalidate_partition(block->gdp, 0);
+	/* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
+	blkdev_put(bdev, FMODE_READ);
+	set_capacity(block->gdp, 0);
+}
+
+int dasd_gendisk_init(void)
+{
+	int rc;
+
+	/* Register to static dasd major 94 */
+	rc = register_blkdev(DASD_MAJOR, "dasd");
+	if (rc != 0) {
+		pr_warn("Registering the device driver with major number %d failed\n",
+			DASD_MAJOR);
+		return rc;
+	}
+	return 0;
+}
+
+void dasd_gendisk_exit(void)
+{
+	unregister_blkdev(DASD_MAJOR, "dasd");
+}
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
new file mode 100644
index 000000000..de6b96036
--- /dev/null
+++ b/drivers/s390/block/dasd_int.h
@@ -0,0 +1,1254 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ */
+
+#ifndef DASD_INT_H
+#define DASD_INT_H
+
+/* we keep old device allocation scheme; IOW, minors are still in 0..255 */
+#define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
+#define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
+
+/*
+ * States a dasd device can have:
+ *   new: the dasd_device structure is allocated.
+ *   known: the discipline for the device is identified.
+ *   basic: the device can do basic i/o.
+ *   unfmt: the device could not be analyzed (format is unknown).
+ *   ready: partition detection is done and the device is can do block io.
+ *   online: the device accepts requests from the block device queue.
+ *
+ * Things to do for startup state transitions:
+ *   new -> known: find discipline for the device and create devfs entries.
+ *   known -> basic: request irq line for the device.
+ *   basic -> ready: do the initial analysis, e.g. format detection,
+ *                   do block device setup and detect partitions.
+ *   ready -> online: schedule the device tasklet.
+ * Things to do for shutdown state transitions:
+ *   online -> ready: just set the new device state.
+ *   ready -> basic: flush requests from the block device layer, clear
+ *                   partition information and reset format information.
+ *   basic -> known: terminate all requests and free irq.
+ *   known -> new: remove devfs entries and forget discipline.
+ */
+
+#define DASD_STATE_NEW	  0
+#define DASD_STATE_KNOWN  1
+#define DASD_STATE_BASIC  2
+#define DASD_STATE_UNFMT  3
+#define DASD_STATE_READY  4
+#define DASD_STATE_ONLINE 5
+
+#include <linux/module.h>
+#include <linux/wait.h>
+#include <linux/blkdev.h>
+#include <linux/genhd.h>
+#include <linux/hdreg.h>
+#include <linux/interrupt.h>
+#include <linux/log2.h>
+#include <asm/ccwdev.h>
+#include <linux/workqueue.h>
+#include <asm/debug.h>
+#include <asm/dasd.h>
+#include <asm/idals.h>
+#include <linux/bitops.h>
+#include <linux/blk-mq.h>
+
+/* DASD discipline magic */
+#define DASD_ECKD_MAGIC 0xC5C3D2C4
+#define DASD_DIAG_MAGIC 0xC4C9C1C7
+#define DASD_FBA_MAGIC 0xC6C2C140
+
+/*
+ * SECTION: Type definitions
+ */
+struct dasd_device;
+struct dasd_block;
+
+/* BIT DEFINITIONS FOR SENSE DATA */
+#define DASD_SENSE_BIT_0 0x80
+#define DASD_SENSE_BIT_1 0x40
+#define DASD_SENSE_BIT_2 0x20
+#define DASD_SENSE_BIT_3 0x10
+
+/* BIT DEFINITIONS FOR SIM SENSE */
+#define DASD_SIM_SENSE 0x0F
+#define DASD_SIM_MSG_TO_OP 0x03
+#define DASD_SIM_LOG 0x0C
+
+/* lock class for nested cdev lock */
+#define CDEV_NESTED_FIRST 1
+#define CDEV_NESTED_SECOND 2
+
+/*
+ * SECTION: MACROs for klogd and s390 debug feature (dbf)
+ */
+#define DBF_DEV_EVENT(d_level, d_device, d_str, d_data...) \
+do { \
+	debug_sprintf_event(d_device->debug_area, \
+			    d_level, \
+			    d_str "\n", \
+			    d_data); \
+} while(0)
+
+#define DBF_EVENT(d_level, d_str, d_data...)\
+do { \
+	debug_sprintf_event(dasd_debug_area, \
+			    d_level,\
+			    d_str "\n", \
+			    d_data); \
+} while(0)
+
+#define DBF_EVENT_DEVID(d_level, d_cdev, d_str, d_data...)	\
+do { \
+	struct ccw_dev_id __dev_id;			\
+	ccw_device_get_id(d_cdev, &__dev_id);		\
+	debug_sprintf_event(dasd_debug_area,		\
+			    d_level,					\
+			    "0.%x.%04x " d_str "\n",			\
+			    __dev_id.ssid, __dev_id.devno, d_data);	\
+} while (0)
+
+/* limit size for an errorstring */
+#define ERRORLENGTH 30
+
+/* definition of dbf debug levels */
+#define	DBF_EMERG	0	/* system is unusable			*/
+#define	DBF_ALERT	1	/* action must be taken immediately	*/
+#define	DBF_CRIT	2	/* critical conditions			*/
+#define	DBF_ERR		3	/* error conditions			*/
+#define	DBF_WARNING	4	/* warning conditions			*/
+#define	DBF_NOTICE	5	/* normal but significant condition	*/
+#define	DBF_INFO	6	/* informational			*/
+#define	DBF_DEBUG	6	/* debug-level messages			*/
+
+/* messages to be written via klogd and dbf */
+#define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
+do { \
+	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
+	       dev_name(&d_device->cdev->dev), d_args); \
+	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
+} while(0)
+
+#define MESSAGE(d_loglevel,d_string,d_args...)\
+do { \
+	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
+	DBF_EVENT(DBF_ALERT, d_string, d_args); \
+} while(0)
+
+/* messages to be written via klogd only */
+#define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
+do { \
+	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
+	       dev_name(&d_device->cdev->dev), d_args); \
+} while(0)
+
+#define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
+do { \
+	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
+} while(0)
+
+/* Macro to calculate number of blocks per page */
+#define BLOCKS_PER_PAGE(blksize) (PAGE_SIZE / blksize)
+
+struct dasd_ccw_req {
+	unsigned int magic;		/* Eye catcher */
+	int intrc;			/* internal error, e.g. from start_IO */
+	struct list_head devlist;	/* for dasd_device request queue */
+	struct list_head blocklist;	/* for dasd_block request queue */
+	struct dasd_block *block;	/* the originating block device */
+	struct dasd_device *memdev;	/* the device used to allocate this */
+	struct dasd_device *startdev;	/* device the request is started on */
+	struct dasd_device *basedev;	/* base device if no block->base */
+	void *cpaddr;			/* address of ccw or tcw */
+	short retries;			/* A retry counter */
+	unsigned char cpmode;		/* 0 = cmd mode, 1 = itcw */
+	char status;			/* status of this request */
+	char lpm;			/* logical path mask */
+	unsigned long flags;        	/* flags of this request */
+	struct dasd_queue *dq;
+	unsigned long starttime;	/* jiffies time of request start */
+	unsigned long expires;		/* expiration period in jiffies */
+	void *data;			/* pointer to data area */
+	struct irb irb;			/* device status in case of an error */
+	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
+	void *function; 		/* originating ERP action */
+	void *mem_chunk;
+
+	unsigned long buildclk;		/* TOD-clock of request generation */
+	unsigned long startclk;		/* TOD-clock of request start */
+	unsigned long stopclk;		/* TOD-clock of request interrupt */
+	unsigned long endclk;		/* TOD-clock of request termination */
+
+	void (*callback)(struct dasd_ccw_req *, void *data);
+	void *callback_data;
+};
+
+/*
+ * dasd_ccw_req -> status can be:
+ */
+#define DASD_CQR_FILLED 	0x00	/* request is ready to be processed */
+#define DASD_CQR_DONE		0x01	/* request is completed successfully */
+#define DASD_CQR_NEED_ERP	0x02	/* request needs recovery action */
+#define DASD_CQR_IN_ERP 	0x03	/* request is in recovery */
+#define DASD_CQR_FAILED 	0x04	/* request is finally failed */
+#define DASD_CQR_TERMINATED	0x05	/* request was stopped by driver */
+
+#define DASD_CQR_QUEUED 	0x80	/* request is queued to be processed */
+#define DASD_CQR_IN_IO		0x81	/* request is currently in IO */
+#define DASD_CQR_ERROR		0x82	/* request is completed with error */
+#define DASD_CQR_CLEAR_PENDING	0x83	/* request is clear pending */
+#define DASD_CQR_CLEARED	0x84	/* request was cleared */
+#define DASD_CQR_SUCCESS	0x85	/* request was successful */
+
+/* default expiration time*/
+#define DASD_EXPIRES	  300
+#define DASD_EXPIRES_MAX  40000000
+#define DASD_RETRIES	  256
+#define DASD_RETRIES_MAX  32768
+
+/* per dasd_ccw_req flags */
+#define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
+#define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
+#define DASD_CQR_VERIFY_PATH	 2	/* path verification request */
+#define DASD_CQR_ALLOW_SLOCK	 3	/* Try this request even when lock was
+					 * stolen. Should not be combined with
+					 * DASD_CQR_FLAGS_USE_ERP
+					 */
+/*
+ * The following flags are used to suppress output of certain errors.
+ */
+#define DASD_CQR_SUPPRESS_NRF	4	/* Suppress 'No Record Found' error */
+#define DASD_CQR_SUPPRESS_FP	5	/* Suppress 'File Protected' error*/
+#define DASD_CQR_SUPPRESS_IL	6	/* Suppress 'Incorrect Length' error */
+#define DASD_CQR_SUPPRESS_CR	7	/* Suppress 'Command Reject' error */
+
+#define DASD_REQ_PER_DEV 4
+
+/* Signature for error recovery functions. */
+typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
+
+/*
+ * A single CQR can only contain a maximum of 255 CCWs. It is limited by
+ * the locate record and locate record extended count value which can only hold
+ * 1 Byte max.
+ */
+#define DASD_CQR_MAX_CCW 255
+
+/*
+ * Unique identifier for dasd device.
+ */
+#define UA_NOT_CONFIGURED  0x00
+#define UA_BASE_DEVICE	   0x01
+#define UA_BASE_PAV_ALIAS  0x02
+#define UA_HYPER_PAV_ALIAS 0x03
+
+struct dasd_uid {
+	__u8 type;
+	char vendor[4];
+	char serial[15];
+	__u16 ssid;
+	__u8 real_unit_addr;
+	__u8 base_unit_addr;
+	char vduit[33];
+};
+
+/*
+ * the struct dasd_discipline is
+ * sth like a table of virtual functions, if you think of dasd_eckd
+ * inheriting dasd...
+ * no, currently we are not planning to reimplement the driver in C++
+ */
+struct dasd_discipline {
+	struct module *owner;
+	char ebcname[8];	/* a name used for tagging and printks */
+	char name[8];		/* a name used for tagging and printks */
+	int max_blocks;		/* maximum number of blocks to be chained */
+
+	struct list_head list;	/* used for list of disciplines */
+
+	/*
+	 * Device recognition functions. check_device is used to verify
+	 * the sense data and the information returned by read device
+	 * characteristics. It returns 0 if the discipline can be used
+	 * for the device in question. uncheck_device is called during
+	 * device shutdown to deregister a device from its discipline.
+	 */
+	int (*check_device) (struct dasd_device *);
+	void (*uncheck_device) (struct dasd_device *);
+
+	/*
+	 * do_analysis is used in the step from device state "basic" to
+	 * state "accept". It returns 0 if the device can be made ready,
+	 * it returns -EMEDIUMTYPE if the device can't be made ready or
+	 * -EAGAIN if do_analysis started a ccw that needs to complete
+	 * before the analysis may be repeated.
+	 */
+	int (*do_analysis) (struct dasd_block *);
+
+	/*
+	 * This function is called, when new paths become available.
+	 * Disciplins may use this callback to do necessary setup work,
+	 * e.g. verify that new path is compatible with the current
+	 * configuration.
+	 */
+	int (*verify_path)(struct dasd_device *, __u8);
+
+	/*
+	 * Last things to do when a device is set online, and first things
+	 * when it is set offline.
+	 */
+	int (*basic_to_ready) (struct dasd_device *);
+	int (*online_to_ready) (struct dasd_device *);
+	int (*basic_to_known)(struct dasd_device *);
+
+	/* (struct dasd_device *);
+	 * Device operation functions. build_cp creates a ccw chain for
+	 * a block device request, start_io starts the request and
+	 * term_IO cancels it (e.g. in case of a timeout). format_device
+	 * formats the device and check_device_format compares the format of
+	 * a device with the expected format_data.
+	 * handle_terminated_request allows to examine a cqr and prepare
+	 * it for retry.
+	 */
+	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
+					  struct dasd_block *,
+					  struct request *);
+	int (*start_IO) (struct dasd_ccw_req *);
+	int (*term_IO) (struct dasd_ccw_req *);
+	void (*handle_terminated_request) (struct dasd_ccw_req *);
+	int (*format_device) (struct dasd_device *,
+			      struct format_data_t *, int);
+	int (*check_device_format)(struct dasd_device *,
+				   struct format_check_t *, int);
+	int (*free_cp) (struct dasd_ccw_req *, struct request *);
+
+	/*
+	 * Error recovery functions. examine_error() returns a value that
+	 * indicates what to do for an error condition. If examine_error()
+	 * returns 'dasd_era_recover' erp_action() is called to create a
+	 * special error recovery ccw. erp_postaction() is called after
+	 * an error recovery ccw has finished its execution. dump_sense
+	 * is called for every error condition to print the sense data
+	 * to the console.
+	 */
+	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
+	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
+	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
+			    struct irb *);
+	void (*dump_sense_dbf) (struct dasd_device *, struct irb *, char *);
+	void (*check_for_device_change) (struct dasd_device *,
+					 struct dasd_ccw_req *,
+					 struct irb *);
+
+        /* i/o control functions. */
+	int (*fill_geometry) (struct dasd_block *, struct hd_geometry *);
+	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
+	int (*ioctl) (struct dasd_block *, unsigned int, void __user *);
+
+	/* suspend/resume functions */
+	int (*freeze) (struct dasd_device *);
+	int (*restore) (struct dasd_device *);
+
+	/* reload device after state change */
+	int (*reload) (struct dasd_device *);
+
+	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
+	void (*kick_validate) (struct dasd_device *);
+	int (*check_attention)(struct dasd_device *, __u8);
+	int (*host_access_count)(struct dasd_device *);
+	int (*hosts_print)(struct dasd_device *, struct seq_file *);
+	void (*handle_hpf_error)(struct dasd_device *, struct irb *);
+	void (*disable_hpf)(struct dasd_device *);
+	int (*hpf_enabled)(struct dasd_device *);
+	void (*reset_path)(struct dasd_device *, __u8);
+};
+
+extern struct dasd_discipline *dasd_diag_discipline_pointer;
+
+/*
+ * Notification numbers for extended error reporting notifications:
+ * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
+ * eer pointer) is freed. The error reporting module needs to do all necessary
+ * cleanup steps.
+ * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
+ */
+#define DASD_EER_DISABLE 0
+#define DASD_EER_TRIGGER 1
+
+/* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
+#define DASD_EER_FATALERROR  1
+#define DASD_EER_NOPATH      2
+#define DASD_EER_STATECHANGE 3
+#define DASD_EER_PPRCSUSPEND 4
+
+/* DASD path handling */
+
+#define DASD_PATH_OPERATIONAL  1
+#define DASD_PATH_TBV	       2
+#define DASD_PATH_PP	       3
+#define DASD_PATH_NPP	       4
+#define DASD_PATH_MISCABLED    5
+#define DASD_PATH_NOHPF        6
+#define DASD_PATH_CUIR	       7
+#define DASD_PATH_IFCC	       8
+
+#define DASD_THRHLD_MAX		4294967295U
+#define DASD_INTERVAL_MAX	4294967295U
+
+struct dasd_path {
+	unsigned long flags;
+	u8 cssid;
+	u8 ssid;
+	u8 chpid;
+	struct dasd_conf_data *conf_data;
+	atomic_t error_count;
+	unsigned long errorclk;
+};
+
+
+struct dasd_profile_info {
+	/* legacy part of profile data, as in dasd_profile_info_t */
+	unsigned int dasd_io_reqs;	 /* number of requests processed */
+	unsigned int dasd_io_sects;	 /* number of sectors processed */
+	unsigned int dasd_io_secs[32];	 /* histogram of request's sizes */
+	unsigned int dasd_io_times[32];	 /* histogram of requests's times */
+	unsigned int dasd_io_timps[32];	 /* h. of requests's times per sector */
+	unsigned int dasd_io_time1[32];	 /* hist. of time from build to start */
+	unsigned int dasd_io_time2[32];	 /* hist. of time from start to irq */
+	unsigned int dasd_io_time2ps[32]; /* hist. of time from start to irq */
+	unsigned int dasd_io_time3[32];	 /* hist. of time from irq to end */
+	unsigned int dasd_io_nr_req[32]; /* hist. of # of requests in chanq */
+
+	/* new data */
+	struct timespec64 starttod;	   /* time of start or last reset */
+	unsigned int dasd_io_alias;	   /* requests using an alias */
+	unsigned int dasd_io_tpm;	   /* requests using transport mode */
+	unsigned int dasd_read_reqs;	   /* total number of read  requests */
+	unsigned int dasd_read_sects;	   /* total number read sectors */
+	unsigned int dasd_read_alias;	   /* read request using an alias */
+	unsigned int dasd_read_tpm;	   /* read requests in transport mode */
+	unsigned int dasd_read_secs[32];   /* histogram of request's sizes */
+	unsigned int dasd_read_times[32];  /* histogram of requests's times */
+	unsigned int dasd_read_time1[32];  /* hist. time from build to start */
+	unsigned int dasd_read_time2[32];  /* hist. of time from start to irq */
+	unsigned int dasd_read_time3[32];  /* hist. of time from irq to end */
+	unsigned int dasd_read_nr_req[32]; /* hist. of # of requests in chanq */
+	unsigned long dasd_sum_times;	   /* sum of request times */
+	unsigned long dasd_sum_time_str;   /* sum of time from build to start */
+	unsigned long dasd_sum_time_irq;   /* sum of time from start to irq */
+	unsigned long dasd_sum_time_end;   /* sum of time from irq to end */
+};
+
+struct dasd_profile {
+	struct dentry *dentry;
+	struct dasd_profile_info *data;
+	spinlock_t lock;
+};
+
+struct dasd_device {
+	/* Block device stuff. */
+	struct dasd_block *block;
+
+        unsigned int devindex;
+	unsigned long flags;	   /* per device flags */
+	unsigned short features;   /* copy of devmap-features (read-only!) */
+
+	/* extended error reporting stuff (eer) */
+	struct dasd_ccw_req *eer_cqr;
+
+	/* Device discipline stuff. */
+	struct dasd_discipline *discipline;
+	struct dasd_discipline *base_discipline;
+	void *private;
+	struct dasd_path path[8];
+	__u8 opm;
+
+	/* Device state and target state. */
+	int state, target;
+	struct mutex state_mutex;
+	int stopped;		/* device (ccw_device_start) was stopped */
+
+	/* reference count. */
+        atomic_t ref_count;
+
+	/* ccw queue and memory for static ccw/erp buffers. */
+	struct list_head ccw_queue;
+	spinlock_t mem_lock;
+	void *ccw_mem;
+	void *erp_mem;
+	struct list_head ccw_chunks;
+	struct list_head erp_chunks;
+
+	atomic_t tasklet_scheduled;
+        struct tasklet_struct tasklet;
+	struct work_struct kick_work;
+	struct work_struct restore_device;
+	struct work_struct reload_device;
+	struct work_struct kick_validate;
+	struct work_struct suc_work;
+	struct work_struct requeue_requests;
+	struct timer_list timer;
+
+	debug_info_t *debug_area;
+
+	struct ccw_device *cdev;
+
+	/* hook for alias management */
+	struct list_head alias_list;
+
+	/* default expiration time in s */
+	unsigned long default_expires;
+	unsigned long default_retries;
+
+	unsigned long blk_timeout;
+
+	unsigned long path_thrhld;
+	unsigned long path_interval;
+
+	struct dentry *debugfs_dentry;
+	struct dentry *hosts_dentry;
+	struct dasd_profile profile;
+};
+
+struct dasd_block {
+	/* Block device stuff. */
+	struct gendisk *gdp;
+	struct request_queue *request_queue;
+	spinlock_t request_queue_lock;
+	struct blk_mq_tag_set tag_set;
+	struct block_device *bdev;
+	atomic_t open_count;
+
+	unsigned long blocks;	   /* size of volume in blocks */
+	unsigned int bp_block;	   /* bytes per block */
+	unsigned int s2b_shift;	   /* log2 (bp_block/512) */
+
+	struct dasd_device *base;
+	struct list_head ccw_queue;
+	spinlock_t queue_lock;
+
+	atomic_t tasklet_scheduled;
+	struct tasklet_struct tasklet;
+	struct timer_list timer;
+
+	struct dentry *debugfs_dentry;
+	struct dasd_profile profile;
+};
+
+struct dasd_attention_data {
+	struct dasd_device *device;
+	__u8 lpum;
+};
+
+struct dasd_queue {
+	spinlock_t lock;
+};
+
+/* reasons why device (ccw_device_start) was stopped */
+#define DASD_STOPPED_NOT_ACC 1         /* not accessible */
+#define DASD_STOPPED_QUIESCE 2         /* Quiesced */
+#define DASD_STOPPED_PENDING 4         /* long busy */
+#define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
+#define DASD_STOPPED_SU      16        /* summary unit check handling */
+#define DASD_STOPPED_PM      32        /* pm state transition */
+#define DASD_UNRESUMED_PM    64        /* pm resume failed state */
+
+/* per device flags */
+#define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
+#define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
+#define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
+#define DASD_FLAG_DEVICE_RO	6	/* The device itself is read-only. Don't
+					 * confuse this with the user specified
+					 * read-only feature.
+					 */
+#define DASD_FLAG_IS_RESERVED	7	/* The device is reserved */
+#define DASD_FLAG_LOCK_STOLEN	8	/* The device lock was stolen */
+#define DASD_FLAG_SUSPENDED	9	/* The device was suspended */
+#define DASD_FLAG_SAFE_OFFLINE	10	/* safe offline processing requested*/
+#define DASD_FLAG_SAFE_OFFLINE_RUNNING	11	/* safe offline running */
+#define DASD_FLAG_ABORTALL	12	/* Abort all noretry requests */
+#define DASD_FLAG_PATH_VERIFY	13	/* Path verification worker running */
+#define DASD_FLAG_SUC		14	/* unhandled summary unit check */
+
+#define DASD_SLEEPON_START_TAG	((void *) 1)
+#define DASD_SLEEPON_END_TAG	((void *) 2)
+
+void dasd_put_device_wake(struct dasd_device *);
+
+/*
+ * Reference count inliners
+ */
+static inline void
+dasd_get_device(struct dasd_device *device)
+{
+	atomic_inc(&device->ref_count);
+}
+
+static inline void
+dasd_put_device(struct dasd_device *device)
+{
+	if (atomic_dec_return(&device->ref_count) == 0)
+		dasd_put_device_wake(device);
+}
+
+/*
+ * The static memory in ccw_mem and erp_mem is managed by a sorted
+ * list of free memory chunks.
+ */
+struct dasd_mchunk
+{
+	struct list_head list;
+	unsigned long size;
+} __attribute__ ((aligned(8)));
+
+static inline void
+dasd_init_chunklist(struct list_head *chunk_list, void *mem,
+		    unsigned long size)
+{
+	struct dasd_mchunk *chunk;
+
+	INIT_LIST_HEAD(chunk_list);
+	chunk = (struct dasd_mchunk *) mem;
+	chunk->size = size - sizeof(struct dasd_mchunk);
+	list_add(&chunk->list, chunk_list);
+}
+
+static inline void *
+dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
+{
+	struct dasd_mchunk *chunk, *tmp;
+
+	size = (size + 7L) & -8L;
+	list_for_each_entry(chunk, chunk_list, list) {
+		if (chunk->size < size)
+			continue;
+		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
+			char *endaddr = (char *) (chunk + 1) + chunk->size;
+			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
+			tmp->size = size;
+			chunk->size -= size + sizeof(struct dasd_mchunk);
+			chunk = tmp;
+		} else
+			list_del(&chunk->list);
+		return (void *) (chunk + 1);
+	}
+	return NULL;
+}
+
+static inline void
+dasd_free_chunk(struct list_head *chunk_list, void *mem)
+{
+	struct dasd_mchunk *chunk, *tmp;
+	struct list_head *p, *left;
+
+	chunk = (struct dasd_mchunk *)
+		((char *) mem - sizeof(struct dasd_mchunk));
+	/* Find out the left neighbour in chunk_list. */
+	left = chunk_list;
+	list_for_each(p, chunk_list) {
+		if (list_entry(p, struct dasd_mchunk, list) > chunk)
+			break;
+		left = p;
+	}
+	/* Try to merge with right neighbour = next element from left. */
+	if (left->next != chunk_list) {
+		tmp = list_entry(left->next, struct dasd_mchunk, list);
+		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
+			list_del(&tmp->list);
+			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
+		}
+	}
+	/* Try to merge with left neighbour. */
+	if (left != chunk_list) {
+		tmp = list_entry(left, struct dasd_mchunk, list);
+		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
+			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
+			return;
+		}
+	}
+	__list_add(&chunk->list, left, left->next);
+}
+
+/*
+ * Check if bsize is in { 512, 1024, 2048, 4096 }
+ */
+static inline int
+dasd_check_blocksize(int bsize)
+{
+	if (bsize < 512 || bsize > 4096 || !is_power_of_2(bsize))
+		return -EMEDIUMTYPE;
+	return 0;
+}
+
+/* externals in dasd.c */
+#define DASD_PROFILE_OFF	 0
+#define DASD_PROFILE_ON 	 1
+#define DASD_PROFILE_GLOBAL_ONLY 2
+
+extern debug_info_t *dasd_debug_area;
+extern struct dasd_profile dasd_global_profile;
+extern unsigned int dasd_global_profile_level;
+extern const struct block_device_operations dasd_device_operations;
+
+extern struct kmem_cache *dasd_page_cache;
+
+struct dasd_ccw_req *
+dasd_smalloc_request(int, int, int, struct dasd_device *, struct dasd_ccw_req *);
+void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
+void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
+
+struct dasd_device *dasd_alloc_device(void);
+void dasd_free_device(struct dasd_device *);
+
+struct dasd_block *dasd_alloc_block(void);
+void dasd_free_block(struct dasd_block *);
+
+enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved);
+
+void dasd_enable_device(struct dasd_device *);
+void dasd_set_target_state(struct dasd_device *, int);
+void dasd_kick_device(struct dasd_device *);
+void dasd_restore_device(struct dasd_device *);
+void dasd_reload_device(struct dasd_device *);
+void dasd_schedule_requeue(struct dasd_device *);
+
+void dasd_add_request_head(struct dasd_ccw_req *);
+void dasd_add_request_tail(struct dasd_ccw_req *);
+int  dasd_start_IO(struct dasd_ccw_req *);
+int  dasd_term_IO(struct dasd_ccw_req *);
+void dasd_schedule_device_bh(struct dasd_device *);
+void dasd_schedule_block_bh(struct dasd_block *);
+int  dasd_sleep_on(struct dasd_ccw_req *);
+int  dasd_sleep_on_queue(struct list_head *);
+int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
+int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
+void dasd_device_set_timer(struct dasd_device *, int);
+void dasd_device_clear_timer(struct dasd_device *);
+void dasd_block_set_timer(struct dasd_block *, int);
+void dasd_block_clear_timer(struct dasd_block *);
+int  dasd_cancel_req(struct dasd_ccw_req *);
+int dasd_flush_device_queue(struct dasd_device *);
+int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
+void dasd_generic_free_discipline(struct dasd_device *);
+void dasd_generic_remove (struct ccw_device *cdev);
+int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
+int dasd_generic_set_offline (struct ccw_device *cdev);
+int dasd_generic_notify(struct ccw_device *, int);
+int dasd_generic_last_path_gone(struct dasd_device *);
+int dasd_generic_path_operational(struct dasd_device *);
+void dasd_generic_shutdown(struct ccw_device *);
+
+void dasd_generic_handle_state_change(struct dasd_device *);
+int dasd_generic_pm_freeze(struct ccw_device *);
+int dasd_generic_restore_device(struct ccw_device *);
+enum uc_todo dasd_generic_uc_handler(struct ccw_device *, struct irb *);
+void dasd_generic_path_event(struct ccw_device *, int *);
+int dasd_generic_verify_path(struct dasd_device *, __u8);
+
+int dasd_generic_read_dev_chars(struct dasd_device *, int, void *, int);
+char *dasd_get_sense(struct irb *);
+
+void dasd_device_set_stop_bits(struct dasd_device *, int);
+void dasd_device_remove_stop_bits(struct dasd_device *, int);
+
+int dasd_device_is_ro(struct dasd_device *);
+
+void dasd_profile_reset(struct dasd_profile *);
+int dasd_profile_on(struct dasd_profile *);
+void dasd_profile_off(struct dasd_profile *);
+char *dasd_get_user_string(const char __user *, size_t);
+
+/* externals in dasd_devmap.c */
+extern int dasd_max_devindex;
+extern int dasd_probeonly;
+extern int dasd_autodetect;
+extern int dasd_nopav;
+extern int dasd_nofcx;
+
+int dasd_devmap_init(void);
+void dasd_devmap_exit(void);
+
+struct dasd_device *dasd_create_device(struct ccw_device *);
+void dasd_delete_device(struct dasd_device *);
+
+int dasd_get_feature(struct ccw_device *, int);
+int dasd_set_feature(struct ccw_device *, int, int);
+
+int dasd_add_sysfs_files(struct ccw_device *);
+void dasd_remove_sysfs_files(struct ccw_device *);
+
+struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
+struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
+struct dasd_device *dasd_device_from_devindex(int);
+
+void dasd_add_link_to_gendisk(struct gendisk *, struct dasd_device *);
+struct dasd_device *dasd_device_from_gendisk(struct gendisk *);
+
+int dasd_parse(void) __init;
+int dasd_busid_known(const char *);
+
+/* externals in dasd_gendisk.c */
+int  dasd_gendisk_init(void);
+void dasd_gendisk_exit(void);
+int dasd_gendisk_alloc(struct dasd_block *);
+void dasd_gendisk_free(struct dasd_block *);
+int dasd_scan_partitions(struct dasd_block *);
+void dasd_destroy_partitions(struct dasd_block *);
+
+/* externals in dasd_ioctl.c */
+int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
+
+/* externals in dasd_proc.c */
+int dasd_proc_init(void);
+void dasd_proc_exit(void);
+
+/* externals in dasd_erp.c */
+struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
+struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
+struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
+					    struct dasd_device *);
+void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
+void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
+void dasd_log_sense_dbf(struct dasd_ccw_req *cqr, struct irb *irb);
+
+/* externals in dasd_3990_erp.c */
+struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
+void dasd_3990_erp_handle_sim(struct dasd_device *, char *);
+
+/* externals in dasd_eer.c */
+#ifdef CONFIG_DASD_EER
+int dasd_eer_init(void);
+void dasd_eer_exit(void);
+int dasd_eer_enable(struct dasd_device *);
+void dasd_eer_disable(struct dasd_device *);
+void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
+		    unsigned int id);
+void dasd_eer_snss(struct dasd_device *);
+
+static inline int dasd_eer_enabled(struct dasd_device *device)
+{
+	return device->eer_cqr != NULL;
+}
+#else
+#define dasd_eer_init()		(0)
+#define dasd_eer_exit()		do { } while (0)
+#define dasd_eer_enable(d)	(0)
+#define dasd_eer_disable(d)	do { } while (0)
+#define dasd_eer_write(d,c,i)	do { } while (0)
+#define dasd_eer_snss(d)	do { } while (0)
+#define dasd_eer_enabled(d)	(0)
+#endif	/* CONFIG_DASD_ERR */
+
+
+/* DASD path handling functions */
+
+/*
+ * helper functions to modify bit masks for a given channel path for a device
+ */
+static inline int dasd_path_is_operational(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_OPERATIONAL, &device->path[chp].flags);
+}
+
+static inline int dasd_path_need_verify(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_TBV, &device->path[chp].flags);
+}
+
+static inline void dasd_path_verify(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_TBV, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_verify(struct dasd_device *device, int chp)
+{
+	__clear_bit(DASD_PATH_TBV, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_all_verify(struct dasd_device *device)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		dasd_path_clear_verify(device, chp);
+}
+
+static inline void dasd_path_operational(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_OPERATIONAL, &device->path[chp].flags);
+	device->opm |= (0x80 >> chp);
+}
+
+static inline void dasd_path_nonpreferred(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_NPP, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_nonpreferred(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_NPP, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_nonpreferred(struct dasd_device *device,
+						int chp)
+{
+	__clear_bit(DASD_PATH_NPP, &device->path[chp].flags);
+}
+
+static inline void dasd_path_preferred(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_PP, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_preferred(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_PP, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_preferred(struct dasd_device *device,
+					     int chp)
+{
+	__clear_bit(DASD_PATH_PP, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_oper(struct dasd_device *device, int chp)
+{
+	__clear_bit(DASD_PATH_OPERATIONAL, &device->path[chp].flags);
+	device->opm &= ~(0x80 >> chp);
+}
+
+static inline void dasd_path_clear_cable(struct dasd_device *device, int chp)
+{
+	__clear_bit(DASD_PATH_MISCABLED, &device->path[chp].flags);
+}
+
+static inline void dasd_path_cuir(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_CUIR, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_cuir(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_CUIR, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_cuir(struct dasd_device *device, int chp)
+{
+	__clear_bit(DASD_PATH_CUIR, &device->path[chp].flags);
+}
+
+static inline void dasd_path_ifcc(struct dasd_device *device, int chp)
+{
+	set_bit(DASD_PATH_IFCC, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_ifcc(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_IFCC, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_ifcc(struct dasd_device *device, int chp)
+{
+	clear_bit(DASD_PATH_IFCC, &device->path[chp].flags);
+}
+
+static inline void dasd_path_clear_nohpf(struct dasd_device *device, int chp)
+{
+	__clear_bit(DASD_PATH_NOHPF, &device->path[chp].flags);
+}
+
+static inline void dasd_path_miscabled(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_MISCABLED, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_miscabled(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_MISCABLED, &device->path[chp].flags);
+}
+
+static inline void dasd_path_nohpf(struct dasd_device *device, int chp)
+{
+	__set_bit(DASD_PATH_NOHPF, &device->path[chp].flags);
+}
+
+static inline int dasd_path_is_nohpf(struct dasd_device *device, int chp)
+{
+	return test_bit(DASD_PATH_NOHPF, &device->path[chp].flags);
+}
+
+/*
+ * get functions for path masks
+ * will return a path masks for the given device
+ */
+
+static inline __u8 dasd_path_get_opm(struct dasd_device *device)
+{
+	return device->opm;
+}
+
+static inline __u8 dasd_path_get_tbvpm(struct dasd_device *device)
+{
+	int chp;
+	__u8 tbvpm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_need_verify(device, chp))
+			tbvpm |= 0x80 >> chp;
+	return tbvpm;
+}
+
+static inline __u8 dasd_path_get_nppm(struct dasd_device *device)
+{
+	int chp;
+	__u8 npm = 0x00;
+
+	for (chp = 0; chp < 8; chp++) {
+		if (dasd_path_is_nonpreferred(device, chp))
+			npm |= 0x80 >> chp;
+	}
+	return npm;
+}
+
+static inline __u8 dasd_path_get_ppm(struct dasd_device *device)
+{
+	int chp;
+	__u8 ppm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_preferred(device, chp))
+			ppm |= 0x80 >> chp;
+	return ppm;
+}
+
+static inline __u8 dasd_path_get_cablepm(struct dasd_device *device)
+{
+	int chp;
+	__u8 cablepm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_miscabled(device, chp))
+			cablepm |= 0x80 >> chp;
+	return cablepm;
+}
+
+static inline __u8 dasd_path_get_cuirpm(struct dasd_device *device)
+{
+	int chp;
+	__u8 cuirpm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_cuir(device, chp))
+			cuirpm |= 0x80 >> chp;
+	return cuirpm;
+}
+
+static inline __u8 dasd_path_get_ifccpm(struct dasd_device *device)
+{
+	int chp;
+	__u8 ifccpm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_ifcc(device, chp))
+			ifccpm |= 0x80 >> chp;
+	return ifccpm;
+}
+
+static inline __u8 dasd_path_get_hpfpm(struct dasd_device *device)
+{
+	int chp;
+	__u8 hpfpm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_nohpf(device, chp))
+			hpfpm |= 0x80 >> chp;
+	return hpfpm;
+}
+
+/*
+ * add functions for path masks
+ * the existing path mask will be extended by the given path mask
+ */
+static inline void dasd_path_add_tbvpm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_verify(device, chp);
+}
+
+static inline __u8 dasd_path_get_notoperpm(struct dasd_device *device)
+{
+	int chp;
+	__u8 nopm = 0x00;
+
+	for (chp = 0; chp < 8; chp++)
+		if (dasd_path_is_nohpf(device, chp) ||
+		    dasd_path_is_ifcc(device, chp) ||
+		    dasd_path_is_cuir(device, chp) ||
+		    dasd_path_is_miscabled(device, chp))
+			nopm |= 0x80 >> chp;
+	return nopm;
+}
+
+static inline void dasd_path_add_opm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp)) {
+			dasd_path_operational(device, chp);
+			/*
+			 * if the path is used
+			 * it should not be in one of the negative lists
+			 */
+			dasd_path_clear_nohpf(device, chp);
+			dasd_path_clear_cuir(device, chp);
+			dasd_path_clear_cable(device, chp);
+			dasd_path_clear_ifcc(device, chp);
+		}
+}
+
+static inline void dasd_path_add_cablepm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_miscabled(device, chp);
+}
+
+static inline void dasd_path_add_cuirpm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_cuir(device, chp);
+}
+
+static inline void dasd_path_add_ifccpm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_ifcc(device, chp);
+}
+
+static inline void dasd_path_add_nppm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_nonpreferred(device, chp);
+}
+
+static inline void dasd_path_add_nohpfpm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_nohpf(device, chp);
+}
+
+static inline void dasd_path_add_ppm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_preferred(device, chp);
+}
+
+/*
+ * set functions for path masks
+ * the existing path mask will be replaced by the given path mask
+ */
+static inline void dasd_path_set_tbvpm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		if (pm & (0x80 >> chp))
+			dasd_path_verify(device, chp);
+		else
+			dasd_path_clear_verify(device, chp);
+}
+
+static inline void dasd_path_set_opm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++) {
+		dasd_path_clear_oper(device, chp);
+		if (pm & (0x80 >> chp)) {
+			dasd_path_operational(device, chp);
+			/*
+			 * if the path is used
+			 * it should not be in one of the negative lists
+			 */
+			dasd_path_clear_nohpf(device, chp);
+			dasd_path_clear_cuir(device, chp);
+			dasd_path_clear_cable(device, chp);
+			dasd_path_clear_ifcc(device, chp);
+		}
+	}
+}
+
+/*
+ * remove functions for path masks
+ * the existing path mask will be cleared with the given path mask
+ */
+static inline void dasd_path_remove_opm(struct dasd_device *device, __u8 pm)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++) {
+		if (pm & (0x80 >> chp))
+			dasd_path_clear_oper(device, chp);
+	}
+}
+
+/*
+ * add the newly available path to the to be verified pm and remove it from
+ * normal operation until it is verified
+ */
+static inline void dasd_path_available(struct dasd_device *device, int chp)
+{
+	dasd_path_clear_oper(device, chp);
+	dasd_path_verify(device, chp);
+}
+
+static inline void dasd_path_notoper(struct dasd_device *device, int chp)
+{
+	dasd_path_clear_oper(device, chp);
+	dasd_path_clear_preferred(device, chp);
+	dasd_path_clear_nonpreferred(device, chp);
+}
+
+/*
+ * remove all paths from normal operation
+ */
+static inline void dasd_path_no_path(struct dasd_device *device)
+{
+	int chp;
+
+	for (chp = 0; chp < 8; chp++)
+		dasd_path_notoper(device, chp);
+
+	dasd_path_clear_all_verify(device);
+}
+
+/* end - path handling */
+
+#endif				/* DASD_H */
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
new file mode 100644
index 000000000..2016e0ed5
--- /dev/null
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -0,0 +1,618 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2001
+ *
+ * i/o controls for the dasd driver.
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/interrupt.h>
+#include <linux/compat.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/blkpg.h>
+#include <linux/slab.h>
+#include <asm/ccwdev.h>
+#include <asm/schid.h>
+#include <asm/cmb.h>
+#include <linux/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_ioctl:"
+
+#include "dasd_int.h"
+
+
+static int
+dasd_ioctl_api_version(void __user *argp)
+{
+	int ver = DASD_API_VERSION;
+	return put_user(ver, (int __user *)argp);
+}
+
+/*
+ * Enable device.
+ * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
+ */
+static int
+dasd_ioctl_enable(struct block_device *bdev)
+{
+	struct dasd_device *base;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+
+	dasd_enable_device(base);
+	/* Formatting the dasd device can change the capacity. */
+	mutex_lock(&bdev->bd_mutex);
+	i_size_write(bdev->bd_inode,
+		     (loff_t)get_capacity(base->block->gdp) << 9);
+	mutex_unlock(&bdev->bd_mutex);
+	dasd_put_device(base);
+	return 0;
+}
+
+/*
+ * Disable device.
+ * Used by dasdfmt. Disable I/O operations but allow ioctls.
+ */
+static int
+dasd_ioctl_disable(struct block_device *bdev)
+{
+	struct dasd_device *base;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	/*
+	 * Man this is sick. We don't do a real disable but only downgrade
+	 * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
+	 * BIODASDDISABLE to disable accesses to the device via the block
+	 * device layer but it still wants to do i/o on the device by
+	 * using the BIODASDFMT ioctl. Therefore the correct state for the
+	 * device is DASD_STATE_BASIC that allows to do basic i/o.
+	 */
+	dasd_set_target_state(base, DASD_STATE_BASIC);
+	/*
+	 * Set i_size to zero, since read, write, etc. check against this
+	 * value.
+	 */
+	mutex_lock(&bdev->bd_mutex);
+	i_size_write(bdev->bd_inode, 0);
+	mutex_unlock(&bdev->bd_mutex);
+	dasd_put_device(base);
+	return 0;
+}
+
+/*
+ * Quiesce device.
+ */
+static int dasd_ioctl_quiesce(struct dasd_block *block)
+{
+	unsigned long flags;
+	struct dasd_device *base;
+
+	base = block->base;
+	if (!capable (CAP_SYS_ADMIN))
+		return -EACCES;
+
+	pr_info("%s: The DASD has been put in the quiesce "
+		"state\n", dev_name(&base->cdev->dev));
+	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
+	dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
+	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
+	return 0;
+}
+
+
+/*
+ * Resume device.
+ */
+static int dasd_ioctl_resume(struct dasd_block *block)
+{
+	unsigned long flags;
+	struct dasd_device *base;
+
+	base = block->base;
+	if (!capable (CAP_SYS_ADMIN))
+		return -EACCES;
+
+	pr_info("%s: I/O operations have been resumed "
+		"on the DASD\n", dev_name(&base->cdev->dev));
+	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
+	dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
+	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
+
+	dasd_schedule_block_bh(block);
+	return 0;
+}
+
+/*
+ * Abort all failfast I/O on a device.
+ */
+static int dasd_ioctl_abortio(struct dasd_block *block)
+{
+	unsigned long flags;
+	struct dasd_device *base;
+	struct dasd_ccw_req *cqr, *n;
+
+	base = block->base;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
+		return 0;
+	DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
+
+	spin_lock_irqsave(&block->request_queue_lock, flags);
+	spin_lock(&block->queue_lock);
+	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
+		if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    cqr->callback_data &&
+		    cqr->callback_data != DASD_SLEEPON_START_TAG &&
+		    cqr->callback_data != DASD_SLEEPON_END_TAG) {
+			spin_unlock(&block->queue_lock);
+			blk_abort_request(cqr->callback_data);
+			spin_lock(&block->queue_lock);
+		}
+	}
+	spin_unlock(&block->queue_lock);
+	spin_unlock_irqrestore(&block->request_queue_lock, flags);
+
+	dasd_schedule_block_bh(block);
+	return 0;
+}
+
+/*
+ * Allow I/O on a device
+ */
+static int dasd_ioctl_allowio(struct dasd_block *block)
+{
+	struct dasd_device *base;
+
+	base = block->base;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
+		DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
+
+	return 0;
+}
+
+/*
+ * performs formatting of _device_ according to _fdata_
+ * Note: The discipline's format_function is assumed to deliver formatting
+ * commands to format multiple units of the device. In terms of the ECKD
+ * devices this means CCWs are generated to format multiple tracks.
+ */
+static int
+dasd_format(struct dasd_block *block, struct format_data_t *fdata)
+{
+	struct dasd_device *base;
+	int rc;
+
+	base = block->base;
+	if (base->discipline->format_device == NULL)
+		return -EPERM;
+
+	if (base->state != DASD_STATE_BASIC) {
+		pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
+			dev_name(&base->cdev->dev));
+		return -EBUSY;
+	}
+
+	DBF_DEV_EVENT(DBF_NOTICE, base,
+		      "formatting units %u to %u (%u B blocks) flags %u",
+		      fdata->start_unit,
+		      fdata->stop_unit, fdata->blksize, fdata->intensity);
+
+	/* Since dasdfmt keeps the device open after it was disabled,
+	 * there still exists an inode for this device.
+	 * We must update i_blkbits, otherwise we might get errors when
+	 * enabling the device later.
+	 */
+	if (fdata->start_unit == 0) {
+		struct block_device *bdev = bdget_disk(block->gdp, 0);
+		bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
+		bdput(bdev);
+	}
+
+	rc = base->discipline->format_device(base, fdata, 1);
+	if (rc == -EAGAIN)
+		rc = base->discipline->format_device(base, fdata, 0);
+
+	return rc;
+}
+
+static int dasd_check_format(struct dasd_block *block,
+			     struct format_check_t *cdata)
+{
+	struct dasd_device *base;
+	int rc;
+
+	base = block->base;
+	if (!base->discipline->check_device_format)
+		return -ENOTTY;
+
+	rc = base->discipline->check_device_format(base, cdata, 1);
+	if (rc == -EAGAIN)
+		rc = base->discipline->check_device_format(base, cdata, 0);
+
+	return rc;
+}
+
+/*
+ * Format device.
+ */
+static int
+dasd_ioctl_format(struct block_device *bdev, void __user *argp)
+{
+	struct dasd_device *base;
+	struct format_data_t fdata;
+	int rc;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (!argp)
+		return -EINVAL;
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (base->features & DASD_FEATURE_READONLY ||
+	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
+		dasd_put_device(base);
+		return -EROFS;
+	}
+	if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
+		dasd_put_device(base);
+		return -EFAULT;
+	}
+	if (bdev != bdev->bd_contains) {
+		pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
+			dev_name(&base->cdev->dev));
+		dasd_put_device(base);
+		return -EINVAL;
+	}
+	rc = dasd_format(base->block, &fdata);
+	dasd_put_device(base);
+
+	return rc;
+}
+
+/*
+ * Check device format
+ */
+static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
+{
+	struct format_check_t cdata;
+	struct dasd_device *base;
+	int rc = 0;
+
+	if (!argp)
+		return -EINVAL;
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (bdev != bdev->bd_contains) {
+		pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
+			dev_name(&base->cdev->dev));
+		rc = -EINVAL;
+		goto out_err;
+	}
+
+	if (copy_from_user(&cdata, argp, sizeof(cdata))) {
+		rc = -EFAULT;
+		goto out_err;
+	}
+
+	rc = dasd_check_format(base->block, &cdata);
+	if (rc)
+		goto out_err;
+
+	if (copy_to_user(argp, &cdata, sizeof(cdata)))
+		rc = -EFAULT;
+
+out_err:
+	dasd_put_device(base);
+
+	return rc;
+}
+
+#ifdef CONFIG_DASD_PROFILE
+/*
+ * Reset device profile information
+ */
+static int dasd_ioctl_reset_profile(struct dasd_block *block)
+{
+	dasd_profile_reset(&block->profile);
+	return 0;
+}
+
+/*
+ * Return device profile information
+ */
+static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
+{
+	struct dasd_profile_info_t *data;
+	int rc = 0;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_bh(&block->profile.lock);
+	if (block->profile.data) {
+		data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
+		data->dasd_io_sects = block->profile.data->dasd_io_sects;
+		memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
+		       sizeof(data->dasd_io_secs));
+		memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
+		       sizeof(data->dasd_io_times));
+		memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
+		       sizeof(data->dasd_io_timps));
+		memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
+		       sizeof(data->dasd_io_time1));
+		memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
+		       sizeof(data->dasd_io_time2));
+		memcpy(data->dasd_io_time2ps,
+		       block->profile.data->dasd_io_time2ps,
+		       sizeof(data->dasd_io_time2ps));
+		memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
+		       sizeof(data->dasd_io_time3));
+		memcpy(data->dasd_io_nr_req,
+		       block->profile.data->dasd_io_nr_req,
+		       sizeof(data->dasd_io_nr_req));
+		spin_unlock_bh(&block->profile.lock);
+	} else {
+		spin_unlock_bh(&block->profile.lock);
+		rc = -EIO;
+		goto out;
+	}
+	if (copy_to_user(argp, data, sizeof(*data)))
+		rc = -EFAULT;
+out:
+	kfree(data);
+	return rc;
+}
+#else
+static int dasd_ioctl_reset_profile(struct dasd_block *block)
+{
+	return -ENOTTY;
+}
+
+static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
+{
+	return -ENOTTY;
+}
+#endif
+
+/*
+ * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
+ */
+static int dasd_ioctl_information(struct dasd_block *block,
+				  unsigned int cmd, void __user *argp)
+{
+	struct dasd_information2_t *dasd_info;
+	struct subchannel_id sch_id;
+	struct ccw_dev_id dev_id;
+	struct dasd_device *base;
+	struct ccw_device *cdev;
+	unsigned long flags;
+	int rc;
+
+	base = block->base;
+	if (!base->discipline || !base->discipline->fill_info)
+		return -EINVAL;
+
+	dasd_info = kzalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
+	if (dasd_info == NULL)
+		return -ENOMEM;
+
+	rc = base->discipline->fill_info(base, dasd_info);
+	if (rc) {
+		kfree(dasd_info);
+		return rc;
+	}
+
+	cdev = base->cdev;
+	ccw_device_get_id(cdev, &dev_id);
+	ccw_device_get_schid(cdev, &sch_id);
+
+	dasd_info->devno = dev_id.devno;
+	dasd_info->schid = sch_id.sch_no;
+	dasd_info->cu_type = cdev->id.cu_type;
+	dasd_info->cu_model = cdev->id.cu_model;
+	dasd_info->dev_type = cdev->id.dev_type;
+	dasd_info->dev_model = cdev->id.dev_model;
+	dasd_info->status = base->state;
+	/*
+	 * The open_count is increased for every opener, that includes
+	 * the blkdev_get in dasd_scan_partitions.
+	 * This must be hidden from user-space.
+	 */
+	dasd_info->open_count = atomic_read(&block->open_count);
+	if (!block->bdev)
+		dasd_info->open_count++;
+
+	/*
+	 * check if device is really formatted
+	 * LDL / CDL was returned by 'fill_info'
+	 */
+	if ((base->state < DASD_STATE_READY) ||
+	    (dasd_check_blocksize(block->bp_block)))
+		dasd_info->format = DASD_FORMAT_NONE;
+
+	dasd_info->features |=
+		((base->features & DASD_FEATURE_READONLY) != 0);
+
+	memcpy(dasd_info->type, base->discipline->name, 4);
+
+	if (block->request_queue->request_fn) {
+		struct list_head *l;
+#ifdef DASD_EXTENDED_PROFILING
+		{
+			struct list_head *l;
+			spin_lock_irqsave(&block->lock, flags);
+			list_for_each(l, &block->request_queue->queue_head)
+				dasd_info->req_queue_len++;
+			spin_unlock_irqrestore(&block->lock, flags);
+		}
+#endif				/* DASD_EXTENDED_PROFILING */
+		spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
+		list_for_each(l, &base->ccw_queue)
+			dasd_info->chanq_len++;
+		spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
+				       flags);
+	}
+
+	rc = 0;
+	if (copy_to_user(argp, dasd_info,
+			 ((cmd == (unsigned int) BIODASDINFO2) ?
+			  sizeof(struct dasd_information2_t) :
+			  sizeof(struct dasd_information_t))))
+		rc = -EFAULT;
+	kfree(dasd_info);
+	return rc;
+}
+
+/*
+ * Set read only
+ */
+static int
+dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
+{
+	struct dasd_device *base;
+	int intval, rc;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (bdev != bdev->bd_contains)
+		// ro setting is not allowed for partitions
+		return -EINVAL;
+	if (get_user(intval, (int __user *)argp))
+		return -EFAULT;
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
+		dasd_put_device(base);
+		return -EROFS;
+	}
+	set_disk_ro(bdev->bd_disk, intval);
+	rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
+	dasd_put_device(base);
+	return rc;
+}
+
+static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
+				  struct cmbdata __user *argp)
+{
+	size_t size = _IOC_SIZE(cmd);
+	struct cmbdata data;
+	int ret;
+
+	ret = cmf_readall(block->base->cdev, &data);
+	if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
+		return -EFAULT;
+	return ret;
+}
+
+int dasd_ioctl(struct block_device *bdev, fmode_t mode,
+	       unsigned int cmd, unsigned long arg)
+{
+	struct dasd_block *block;
+	struct dasd_device *base;
+	void __user *argp;
+	int rc;
+
+	if (is_compat_task())
+		argp = compat_ptr(arg);
+	else
+		argp = (void __user *)arg;
+
+	if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
+		PRINT_DEBUG("empty data ptr");
+		return -EINVAL;
+	}
+
+	base = dasd_device_from_gendisk(bdev->bd_disk);
+	if (!base)
+		return -ENODEV;
+	block = base->block;
+	rc = 0;
+	switch (cmd) {
+	case BIODASDDISABLE:
+		rc = dasd_ioctl_disable(bdev);
+		break;
+	case BIODASDENABLE:
+		rc = dasd_ioctl_enable(bdev);
+		break;
+	case BIODASDQUIESCE:
+		rc = dasd_ioctl_quiesce(block);
+		break;
+	case BIODASDRESUME:
+		rc = dasd_ioctl_resume(block);
+		break;
+	case BIODASDABORTIO:
+		rc = dasd_ioctl_abortio(block);
+		break;
+	case BIODASDALLOWIO:
+		rc = dasd_ioctl_allowio(block);
+		break;
+	case BIODASDFMT:
+		rc = dasd_ioctl_format(bdev, argp);
+		break;
+	case BIODASDCHECKFMT:
+		rc = dasd_ioctl_check_format(bdev, argp);
+		break;
+	case BIODASDINFO:
+		rc = dasd_ioctl_information(block, cmd, argp);
+		break;
+	case BIODASDINFO2:
+		rc = dasd_ioctl_information(block, cmd, argp);
+		break;
+	case BIODASDPRRD:
+		rc = dasd_ioctl_read_profile(block, argp);
+		break;
+	case BIODASDPRRST:
+		rc = dasd_ioctl_reset_profile(block);
+		break;
+	case BLKROSET:
+		rc = dasd_ioctl_set_ro(bdev, argp);
+		break;
+	case DASDAPIVER:
+		rc = dasd_ioctl_api_version(argp);
+		break;
+	case BIODASDCMFENABLE:
+		rc = enable_cmf(base->cdev);
+		break;
+	case BIODASDCMFDISABLE:
+		rc = disable_cmf(base->cdev);
+		break;
+	case BIODASDREADALLCMB:
+		rc = dasd_ioctl_readall_cmb(block, cmd, argp);
+		break;
+	default:
+		/* if the discipline has an ioctl method try it. */
+		rc = -ENOTTY;
+		if (base->discipline->ioctl)
+			rc = base->discipline->ioctl(block, cmd, argp);
+	}
+	dasd_put_device(base);
+	return rc;
+}
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
new file mode 100644
index 000000000..5cb80c645
--- /dev/null
+++ b/drivers/s390/block/dasd_proc.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Coypright IBM Corp. 1999, 2002
+ *
+ * /proc interface for the dasd driver.
+ *
+ */
+
+#define KMSG_COMPONENT "dasd"
+
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+
+#include <asm/debug.h>
+#include <linux/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_proc:"
+
+#include "dasd_int.h"
+
+static struct proc_dir_entry *dasd_proc_root_entry = NULL;
+static struct proc_dir_entry *dasd_devices_entry = NULL;
+static struct proc_dir_entry *dasd_statistics_entry = NULL;
+
+static int
+dasd_devices_show(struct seq_file *m, void *v)
+{
+	struct dasd_device *device;
+	struct dasd_block *block;
+	char *substr;
+
+	device = dasd_device_from_devindex((unsigned long) v - 1);
+	if (IS_ERR(device))
+		return 0;
+	if (device->block)
+		block = device->block;
+	else {
+		dasd_put_device(device);
+		return 0;
+	}
+	/* Print device number. */
+	seq_printf(m, "%s", dev_name(&device->cdev->dev));
+	/* Print discipline string. */
+	if (device->discipline != NULL)
+		seq_printf(m, "(%s)", device->discipline->name);
+	else
+		seq_printf(m, "(none)");
+	/* Print kdev. */
+	if (block->gdp)
+		seq_printf(m, " at (%3d:%6d)",
+			   MAJOR(disk_devt(block->gdp)),
+			   MINOR(disk_devt(block->gdp)));
+	else
+		seq_printf(m, "  at (???:??????)");
+	/* Print device name. */
+	if (block->gdp)
+		seq_printf(m, " is %-8s", block->gdp->disk_name);
+	else
+		seq_printf(m, " is ????????");
+	/* Print devices features. */
+	substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
+	seq_printf(m, "%4s: ", substr);
+	/* Print device status information. */
+	switch (device->state) {
+	case DASD_STATE_NEW:
+		seq_printf(m, "new");
+		break;
+	case DASD_STATE_KNOWN:
+		seq_printf(m, "detected");
+		break;
+	case DASD_STATE_BASIC:
+		seq_printf(m, "basic");
+		break;
+	case DASD_STATE_UNFMT:
+		seq_printf(m, "unformatted");
+		break;
+	case DASD_STATE_READY:
+	case DASD_STATE_ONLINE:
+		seq_printf(m, "active ");
+		if (dasd_check_blocksize(block->bp_block))
+			seq_printf(m, "n/f	 ");
+		else
+			seq_printf(m,
+				   "at blocksize: %u, %lu blocks, %lu MB",
+				   block->bp_block, block->blocks,
+				   ((block->bp_block >> 9) *
+				    block->blocks) >> 11);
+		break;
+	default:
+		seq_printf(m, "no stat");
+		break;
+	}
+	dasd_put_device(device);
+	if (dasd_probeonly)
+		seq_printf(m, "(probeonly)");
+	seq_printf(m, "\n");
+	return 0;
+}
+
+static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
+{
+	if (*pos >= dasd_max_devindex)
+		return NULL;
+	return (void *)((unsigned long) *pos + 1);
+}
+
+static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return dasd_devices_start(m, pos);
+}
+
+static void dasd_devices_stop(struct seq_file *m, void *v)
+{
+}
+
+static const struct seq_operations dasd_devices_seq_ops = {
+	.start		= dasd_devices_start,
+	.next		= dasd_devices_next,
+	.stop		= dasd_devices_stop,
+	.show		= dasd_devices_show,
+};
+
+#ifdef CONFIG_DASD_PROFILE
+static int dasd_stats_all_block_on(void)
+{
+	int i, rc;
+	struct dasd_device *device;
+
+	rc = 0;
+	for (i = 0; i < dasd_max_devindex; ++i) {
+		device = dasd_device_from_devindex(i);
+		if (IS_ERR(device))
+			continue;
+		if (device->block)
+			rc = dasd_profile_on(&device->block->profile);
+		dasd_put_device(device);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+static void dasd_stats_all_block_off(void)
+{
+	int i;
+	struct dasd_device *device;
+
+	for (i = 0; i < dasd_max_devindex; ++i) {
+		device = dasd_device_from_devindex(i);
+		if (IS_ERR(device))
+			continue;
+		if (device->block)
+			dasd_profile_off(&device->block->profile);
+		dasd_put_device(device);
+	}
+}
+
+static void dasd_stats_all_block_reset(void)
+{
+	int i;
+	struct dasd_device *device;
+
+	for (i = 0; i < dasd_max_devindex; ++i) {
+		device = dasd_device_from_devindex(i);
+		if (IS_ERR(device))
+			continue;
+		if (device->block)
+			dasd_profile_reset(&device->block->profile);
+		dasd_put_device(device);
+	}
+}
+
+static void dasd_statistics_array(struct seq_file *m, unsigned int *array, int factor)
+{
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		seq_printf(m, "%7d ", array[i] / factor);
+		if (i == 15)
+			seq_putc(m, '\n');
+	}
+	seq_putc(m, '\n');
+}
+#endif /* CONFIG_DASD_PROFILE */
+
+static int dasd_stats_proc_show(struct seq_file *m, void *v)
+{
+#ifdef CONFIG_DASD_PROFILE
+	struct dasd_profile_info *prof;
+	int factor;
+
+	spin_lock_bh(&dasd_global_profile.lock);
+	prof = dasd_global_profile.data;
+	if (!prof) {
+		spin_unlock_bh(&dasd_global_profile.lock);
+		seq_printf(m, "Statistics are off - they might be "
+				    "switched on using 'echo set on > "
+				    "/proc/dasd/statistics'\n");
+		return 0;
+	}
+
+	/* prevent counter 'overflow' on output */
+	for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
+	     factor *= 10);
+
+	seq_printf(m, "%d dasd I/O requests\n", prof->dasd_io_reqs);
+	seq_printf(m, "with %u sectors(512B each)\n",
+		       prof->dasd_io_sects);
+	seq_printf(m, "Scale Factor is  %d\n", factor);
+	seq_printf(m,
+		       "   __<4	   ___8	   __16	   __32	   __64	   _128	"
+		       "   _256	   _512	   __1k	   __2k	   __4k	   __8k	"
+		       "   _16k	   _32k	   _64k	   128k\n");
+	seq_printf(m,
+		       "   _256	   _512	   __1M	   __2M	   __4M	   __8M	"
+		       "   _16M	   _32M	   _64M	   128M	   256M	   512M	"
+		       "   __1G	   __2G	   __4G " "   _>4G\n");
+
+	seq_printf(m, "Histogram of sizes (512B secs)\n");
+	dasd_statistics_array(m, prof->dasd_io_secs, factor);
+	seq_printf(m, "Histogram of I/O times (microseconds)\n");
+	dasd_statistics_array(m, prof->dasd_io_times, factor);
+	seq_printf(m, "Histogram of I/O times per sector\n");
+	dasd_statistics_array(m, prof->dasd_io_timps, factor);
+	seq_printf(m, "Histogram of I/O time till ssch\n");
+	dasd_statistics_array(m, prof->dasd_io_time1, factor);
+	seq_printf(m, "Histogram of I/O time between ssch and irq\n");
+	dasd_statistics_array(m, prof->dasd_io_time2, factor);
+	seq_printf(m, "Histogram of I/O time between ssch "
+			    "and irq per sector\n");
+	dasd_statistics_array(m, prof->dasd_io_time2ps, factor);
+	seq_printf(m, "Histogram of I/O time between irq and end\n");
+	dasd_statistics_array(m, prof->dasd_io_time3, factor);
+	seq_printf(m, "# of req in chanq at enqueuing (1..32) \n");
+	dasd_statistics_array(m, prof->dasd_io_nr_req, factor);
+	spin_unlock_bh(&dasd_global_profile.lock);
+#else
+	seq_printf(m, "Statistics are not activated in this kernel\n");
+#endif
+	return 0;
+}
+
+static int dasd_stats_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dasd_stats_proc_show, NULL);
+}
+
+static ssize_t dasd_stats_proc_write(struct file *file,
+		const char __user *user_buf, size_t user_len, loff_t *pos)
+{
+#ifdef CONFIG_DASD_PROFILE
+	char *buffer, *str;
+	int rc;
+
+	if (user_len > 65536)
+		user_len = 65536;
+	buffer = dasd_get_user_string(user_buf, user_len);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	/* check for valid verbs */
+	str = skip_spaces(buffer);
+	if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
+		/* 'set xxx' was given */
+		str = skip_spaces(str + 4);
+		if (strcmp(str, "on") == 0) {
+			/* switch on statistics profiling */
+			rc = dasd_stats_all_block_on();
+			if (rc) {
+				dasd_stats_all_block_off();
+				goto out_error;
+			}
+			rc = dasd_profile_on(&dasd_global_profile);
+			if (rc) {
+				dasd_stats_all_block_off();
+				goto out_error;
+			}
+			dasd_profile_reset(&dasd_global_profile);
+			dasd_global_profile_level = DASD_PROFILE_ON;
+			pr_info("The statistics feature has been switched "
+				"on\n");
+		} else if (strcmp(str, "off") == 0) {
+			/* switch off statistics profiling */
+			dasd_global_profile_level = DASD_PROFILE_OFF;
+			dasd_profile_off(&dasd_global_profile);
+			dasd_stats_all_block_off();
+			pr_info("The statistics feature has been switched "
+				"off\n");
+		} else
+			goto out_parse_error;
+	} else if (strncmp(str, "reset", 5) == 0) {
+		/* reset the statistics */
+		dasd_profile_reset(&dasd_global_profile);
+		dasd_stats_all_block_reset();
+		pr_info("The statistics have been reset\n");
+	} else
+		goto out_parse_error;
+	vfree(buffer);
+	return user_len;
+out_parse_error:
+	rc = -EINVAL;
+	pr_warn("%s is not a supported value for /proc/dasd/statistics\n", str);
+out_error:
+	vfree(buffer);
+	return rc;
+#else
+	pr_warn("/proc/dasd/statistics: is not activated in this kernel\n");
+	return user_len;
+#endif				/* CONFIG_DASD_PROFILE */
+}
+
+static const struct file_operations dasd_stats_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_stats_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= dasd_stats_proc_write,
+};
+
+/*
+ * Create dasd proc-fs entries.
+ * In case creation failed, cleanup and return -ENOENT.
+ */
+int
+dasd_proc_init(void)
+{
+	dasd_proc_root_entry = proc_mkdir("dasd", NULL);
+	if (!dasd_proc_root_entry)
+		goto out_nodasd;
+	dasd_devices_entry = proc_create_seq("devices",
+					 S_IFREG | S_IRUGO | S_IWUSR,
+					 dasd_proc_root_entry,
+					 &dasd_devices_seq_ops);
+	if (!dasd_devices_entry)
+		goto out_nodevices;
+	dasd_statistics_entry = proc_create("statistics",
+					    S_IFREG | S_IRUGO | S_IWUSR,
+					    dasd_proc_root_entry,
+					    &dasd_stats_proc_fops);
+	if (!dasd_statistics_entry)
+		goto out_nostatistics;
+	return 0;
+
+ out_nostatistics:
+	remove_proc_entry("devices", dasd_proc_root_entry);
+ out_nodevices:
+	remove_proc_entry("dasd", NULL);
+ out_nodasd:
+	return -ENOENT;
+}
+
+void
+dasd_proc_exit(void)
+{
+	remove_proc_entry("devices", dasd_proc_root_entry);
+	remove_proc_entry("statistics", dasd_proc_root_entry);
+	remove_proc_entry("dasd", NULL);
+}
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
new file mode 100644
index 000000000..4e8aedd50
--- /dev/null
+++ b/drivers/s390/block/dcssblk.c
@@ -0,0 +1,1136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dcssblk.c -- the S/390 block driver for dcss memory
+ *
+ * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer
+ */
+
+#define KMSG_COMPONENT "dcssblk"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pfn_t.h>
+#include <linux/uio.h>
+#include <linux/dax.h>
+#include <asm/extmem.h>
+#include <asm/io.h>
+
+#define DCSSBLK_NAME "dcssblk"
+#define DCSSBLK_MINORS_PER_DISK 1
+#define DCSSBLK_PARM_LEN 400
+#define DCSS_BUS_ID_SIZE 20
+
+static int dcssblk_open(struct block_device *bdev, fmode_t mode);
+static void dcssblk_release(struct gendisk *disk, fmode_t mode);
+static blk_qc_t dcssblk_make_request(struct request_queue *q,
+						struct bio *bio);
+static long dcssblk_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
+		long nr_pages, void **kaddr, pfn_t *pfn);
+
+static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
+
+static int dcssblk_major;
+static const struct block_device_operations dcssblk_devops = {
+	.owner   	= THIS_MODULE,
+	.open    	= dcssblk_open,
+	.release 	= dcssblk_release,
+};
+
+static size_t dcssblk_dax_copy_from_iter(struct dax_device *dax_dev,
+		pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter(addr, bytes, i);
+}
+
+static size_t dcssblk_dax_copy_to_iter(struct dax_device *dax_dev,
+		pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_to_iter(addr, bytes, i);
+}
+
+static const struct dax_operations dcssblk_dax_ops = {
+	.direct_access = dcssblk_dax_direct_access,
+	.copy_from_iter = dcssblk_dax_copy_from_iter,
+	.copy_to_iter = dcssblk_dax_copy_to_iter,
+};
+
+struct dcssblk_dev_info {
+	struct list_head lh;
+	struct device dev;
+	char segment_name[DCSS_BUS_ID_SIZE];
+	atomic_t use_count;
+	struct gendisk *gd;
+	unsigned long start;
+	unsigned long end;
+	int segment_type;
+	unsigned char save_pending;
+	unsigned char is_shared;
+	struct request_queue *dcssblk_queue;
+	int num_of_segments;
+	struct list_head seg_list;
+	struct dax_device *dax_dev;
+};
+
+struct segment_info {
+	struct list_head lh;
+	char segment_name[DCSS_BUS_ID_SIZE];
+	unsigned long start;
+	unsigned long end;
+	int segment_type;
+};
+
+static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
+				  size_t count);
+static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
+				  size_t count);
+
+static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
+static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
+
+static struct device *dcssblk_root_dev;
+
+static LIST_HEAD(dcssblk_devices);
+static struct rw_semaphore dcssblk_devices_sem;
+
+/*
+ * release function for segment device.
+ */
+static void
+dcssblk_release_segment(struct device *dev)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry, *temp;
+
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+	list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
+		list_del(&entry->lh);
+		kfree(entry);
+	}
+	kfree(dev_info);
+	module_put(THIS_MODULE);
+}
+
+/*
+ * get a minor number. needs to be called with
+ * down_write(&dcssblk_devices_sem) and the
+ * device needs to be enqueued before the semaphore is
+ * freed.
+ */
+static int
+dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
+{
+	int minor, found;
+	struct dcssblk_dev_info *entry;
+
+	if (dev_info == NULL)
+		return -EINVAL;
+	for (minor = 0; minor < (1<<MINORBITS); minor++) {
+		found = 0;
+		// test if minor available
+		list_for_each_entry(entry, &dcssblk_devices, lh)
+			if (minor == entry->gd->first_minor)
+				found++;
+		if (!found) break; // got unused minor
+	}
+	if (found)
+		return -EBUSY;
+	dev_info->gd->first_minor = minor;
+	return 0;
+}
+
+/*
+ * get the struct dcssblk_dev_info from dcssblk_devices
+ * for the given name.
+ * down_read(&dcssblk_devices_sem) must be held.
+ */
+static struct dcssblk_dev_info *
+dcssblk_get_device_by_name(char *name)
+{
+	struct dcssblk_dev_info *entry;
+
+	list_for_each_entry(entry, &dcssblk_devices, lh) {
+		if (!strcmp(name, entry->segment_name)) {
+			return entry;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * get the struct segment_info from seg_list
+ * for the given name.
+ * down_read(&dcssblk_devices_sem) must be held.
+ */
+static struct segment_info *
+dcssblk_get_segment_by_name(char *name)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry;
+
+	list_for_each_entry(dev_info, &dcssblk_devices, lh) {
+		list_for_each_entry(entry, &dev_info->seg_list, lh) {
+			if (!strcmp(name, entry->segment_name))
+				return entry;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * get the highest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
+{
+	unsigned long highest_addr;
+	struct segment_info *entry;
+
+	highest_addr = 0;
+	list_for_each_entry(entry, &dev_info->seg_list, lh) {
+		if (highest_addr < entry->end)
+			highest_addr = entry->end;
+	}
+	return highest_addr;
+}
+
+/*
+ * get the lowest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
+{
+	int set_first;
+	unsigned long lowest_addr;
+	struct segment_info *entry;
+
+	set_first = 0;
+	lowest_addr = 0;
+	list_for_each_entry(entry, &dev_info->seg_list, lh) {
+		if (set_first == 0) {
+			lowest_addr = entry->start;
+			set_first = 1;
+		} else {
+			if (lowest_addr > entry->start)
+				lowest_addr = entry->start;
+		}
+	}
+	return lowest_addr;
+}
+
+/*
+ * Check continuity of segments.
+ */
+static int
+dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
+{
+	int i, j, rc;
+	struct segment_info *sort_list, *entry, temp;
+
+	if (dev_info->num_of_segments <= 1)
+		return 0;
+
+	sort_list = kcalloc(dev_info->num_of_segments,
+			    sizeof(struct segment_info),
+			    GFP_KERNEL);
+	if (sort_list == NULL)
+		return -ENOMEM;
+	i = 0;
+	list_for_each_entry(entry, &dev_info->seg_list, lh) {
+		memcpy(&sort_list[i], entry, sizeof(struct segment_info));
+		i++;
+	}
+
+	/* sort segments */
+	for (i = 0; i < dev_info->num_of_segments; i++)
+		for (j = 0; j < dev_info->num_of_segments; j++)
+			if (sort_list[j].start > sort_list[i].start) {
+				memcpy(&temp, &sort_list[i],
+					sizeof(struct segment_info));
+				memcpy(&sort_list[i], &sort_list[j],
+					sizeof(struct segment_info));
+				memcpy(&sort_list[j], &temp,
+					sizeof(struct segment_info));
+			}
+
+	/* check continuity */
+	for (i = 0; i < dev_info->num_of_segments - 1; i++) {
+		if ((sort_list[i].end + 1) != sort_list[i+1].start) {
+			pr_err("Adjacent DCSSs %s and %s are not "
+			       "contiguous\n", sort_list[i].segment_name,
+			       sort_list[i+1].segment_name);
+			rc = -EINVAL;
+			goto out;
+		}
+		/* EN and EW are allowed in a block device */
+		if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
+			if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
+				(sort_list[i].segment_type == SEG_TYPE_ER) ||
+				!(sort_list[i+1].segment_type &
+				SEGMENT_EXCLUSIVE) ||
+				(sort_list[i+1].segment_type == SEG_TYPE_ER)) {
+				pr_err("DCSS %s and DCSS %s have "
+				       "incompatible types\n",
+				       sort_list[i].segment_name,
+				       sort_list[i+1].segment_name);
+				rc = -EINVAL;
+				goto out;
+			}
+		}
+	}
+	rc = 0;
+out:
+	kfree(sort_list);
+	return rc;
+}
+
+/*
+ * Load a segment
+ */
+static int
+dcssblk_load_segment(char *name, struct segment_info **seg_info)
+{
+	int rc;
+
+	/* already loaded? */
+	down_read(&dcssblk_devices_sem);
+	*seg_info = dcssblk_get_segment_by_name(name);
+	up_read(&dcssblk_devices_sem);
+	if (*seg_info != NULL)
+		return -EEXIST;
+
+	/* get a struct segment_info */
+	*seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
+	if (*seg_info == NULL)
+		return -ENOMEM;
+
+	strcpy((*seg_info)->segment_name, name);
+
+	/* load the segment */
+	rc = segment_load(name, SEGMENT_SHARED,
+			&(*seg_info)->start, &(*seg_info)->end);
+	if (rc < 0) {
+		segment_warning(rc, (*seg_info)->segment_name);
+		kfree(*seg_info);
+	} else {
+		INIT_LIST_HEAD(&(*seg_info)->lh);
+		(*seg_info)->segment_type = rc;
+	}
+	return rc;
+}
+
+/*
+ * device attribute for switching shared/nonshared (exclusive)
+ * operation (show + store)
+ */
+static ssize_t
+dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dcssblk_dev_info *dev_info;
+
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+	return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
+}
+
+static ssize_t
+dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry, *temp;
+	int rc;
+
+	if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
+		return -EINVAL;
+	down_write(&dcssblk_devices_sem);
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+	if (atomic_read(&dev_info->use_count)) {
+		rc = -EBUSY;
+		goto out;
+	}
+	if (inbuf[0] == '1') {
+		/* reload segments in shared mode */
+		list_for_each_entry(entry, &dev_info->seg_list, lh) {
+			rc = segment_modify_shared(entry->segment_name,
+						SEGMENT_SHARED);
+			if (rc < 0) {
+				BUG_ON(rc == -EINVAL);
+				if (rc != -EAGAIN)
+					goto removeseg;
+			}
+		}
+		dev_info->is_shared = 1;
+		switch (dev_info->segment_type) {
+		case SEG_TYPE_SR:
+		case SEG_TYPE_ER:
+		case SEG_TYPE_SC:
+			set_disk_ro(dev_info->gd, 1);
+		}
+	} else if (inbuf[0] == '0') {
+		/* reload segments in exclusive mode */
+		if (dev_info->segment_type == SEG_TYPE_SC) {
+			pr_err("DCSS %s is of type SC and cannot be "
+			       "loaded as exclusive-writable\n",
+			       dev_info->segment_name);
+			rc = -EINVAL;
+			goto out;
+		}
+		list_for_each_entry(entry, &dev_info->seg_list, lh) {
+			rc = segment_modify_shared(entry->segment_name,
+						   SEGMENT_EXCLUSIVE);
+			if (rc < 0) {
+				BUG_ON(rc == -EINVAL);
+				if (rc != -EAGAIN)
+					goto removeseg;
+			}
+		}
+		dev_info->is_shared = 0;
+		set_disk_ro(dev_info->gd, 0);
+	} else {
+		rc = -EINVAL;
+		goto out;
+	}
+	rc = count;
+	goto out;
+
+removeseg:
+	pr_err("DCSS device %s is removed after a failed access mode "
+	       "change\n", dev_info->segment_name);
+	temp = entry;
+	list_for_each_entry(entry, &dev_info->seg_list, lh) {
+		if (entry != temp)
+			segment_unload(entry->segment_name);
+	}
+	list_del(&dev_info->lh);
+
+	kill_dax(dev_info->dax_dev);
+	put_dax(dev_info->dax_dev);
+	del_gendisk(dev_info->gd);
+	blk_cleanup_queue(dev_info->dcssblk_queue);
+	dev_info->gd->queue = NULL;
+	put_disk(dev_info->gd);
+	up_write(&dcssblk_devices_sem);
+
+	if (device_remove_file_self(dev, attr)) {
+		device_unregister(dev);
+		put_device(dev);
+	}
+	return rc;
+out:
+	up_write(&dcssblk_devices_sem);
+	return rc;
+}
+static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
+		   dcssblk_shared_store);
+
+/*
+ * device attribute for save operation on current copy
+ * of the segment. If the segment is busy, saving will
+ * become pending until it gets released, which can be
+ * undone by storing a non-true value to this entry.
+ * (show + store)
+ */
+static ssize_t
+dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dcssblk_dev_info *dev_info;
+
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+	return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
+}
+
+static ssize_t
+dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry;
+
+	if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
+		return -EINVAL;
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+
+	down_write(&dcssblk_devices_sem);
+	if (inbuf[0] == '1') {
+		if (atomic_read(&dev_info->use_count) == 0) {
+			// device is idle => we save immediately
+			pr_info("All DCSSs that map to device %s are "
+				"saved\n", dev_info->segment_name);
+			list_for_each_entry(entry, &dev_info->seg_list, lh) {
+				if (entry->segment_type == SEG_TYPE_EN ||
+				    entry->segment_type == SEG_TYPE_SN)
+					pr_warn("DCSS %s is of type SN or EN"
+						" and cannot be saved\n",
+						entry->segment_name);
+				else
+					segment_save(entry->segment_name);
+			}
+		}  else {
+			// device is busy => we save it when it becomes
+			// idle in dcssblk_release
+			pr_info("Device %s is in use, its DCSSs will be "
+				"saved when it becomes idle\n",
+				dev_info->segment_name);
+			dev_info->save_pending = 1;
+		}
+	} else if (inbuf[0] == '0') {
+		if (dev_info->save_pending) {
+			// device is busy & the user wants to undo his save
+			// request
+			dev_info->save_pending = 0;
+			pr_info("A pending save request for device %s "
+				"has been canceled\n",
+				dev_info->segment_name);
+		}
+	} else {
+		up_write(&dcssblk_devices_sem);
+		return -EINVAL;
+	}
+	up_write(&dcssblk_devices_sem);
+	return count;
+}
+static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
+		   dcssblk_save_store);
+
+/*
+ * device attribute for showing all segments in a device
+ */
+static ssize_t
+dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	int i;
+
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry;
+
+	down_read(&dcssblk_devices_sem);
+	dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+	i = 0;
+	buf[0] = '\0';
+	list_for_each_entry(entry, &dev_info->seg_list, lh) {
+		strcpy(&buf[i], entry->segment_name);
+		i += strlen(entry->segment_name);
+		buf[i] = '\n';
+		i++;
+	}
+	up_read(&dcssblk_devices_sem);
+	return i;
+}
+static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
+
+static struct attribute *dcssblk_dev_attrs[] = {
+	&dev_attr_shared.attr,
+	&dev_attr_save.attr,
+	&dev_attr_seglist.attr,
+	NULL,
+};
+static struct attribute_group dcssblk_dev_attr_group = {
+	.attrs = dcssblk_dev_attrs,
+};
+static const struct attribute_group *dcssblk_dev_attr_groups[] = {
+	&dcssblk_dev_attr_group,
+	NULL,
+};
+
+/*
+ * device attribute for adding devices
+ */
+static ssize_t
+dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+	int rc, i, j, num_of_segments;
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *seg_info, *temp;
+	char *local_buf;
+	unsigned long seg_byte_size;
+
+	dev_info = NULL;
+	seg_info = NULL;
+	if (dev != dcssblk_root_dev) {
+		rc = -EINVAL;
+		goto out_nobuf;
+	}
+	if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
+		rc = -ENAMETOOLONG;
+		goto out_nobuf;
+	}
+
+	local_buf = kmalloc(count + 1, GFP_KERNEL);
+	if (local_buf == NULL) {
+		rc = -ENOMEM;
+		goto out_nobuf;
+	}
+
+	/*
+	 * parse input
+	 */
+	num_of_segments = 0;
+	for (i = 0; (i < count && (buf[i] != '\0') && (buf[i] != '\n')); i++) {
+		for (j = i; j < count &&
+			(buf[j] != ':') &&
+			(buf[j] != '\0') &&
+			(buf[j] != '\n'); j++) {
+			local_buf[j-i] = toupper(buf[j]);
+		}
+		local_buf[j-i] = '\0';
+		if (((j - i) == 0) || ((j - i) > 8)) {
+			rc = -ENAMETOOLONG;
+			goto seg_list_del;
+		}
+
+		rc = dcssblk_load_segment(local_buf, &seg_info);
+		if (rc < 0)
+			goto seg_list_del;
+		/*
+		 * get a struct dcssblk_dev_info
+		 */
+		if (num_of_segments == 0) {
+			dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
+					GFP_KERNEL);
+			if (dev_info == NULL) {
+				rc = -ENOMEM;
+				goto out;
+			}
+			strcpy(dev_info->segment_name, local_buf);
+			dev_info->segment_type = seg_info->segment_type;
+			INIT_LIST_HEAD(&dev_info->seg_list);
+		}
+		list_add_tail(&seg_info->lh, &dev_info->seg_list);
+		num_of_segments++;
+		i = j;
+
+		if ((buf[j] == '\0') || (buf[j] == '\n'))
+			break;
+	}
+
+	/* no trailing colon at the end of the input */
+	if ((i > 0) && (buf[i-1] == ':')) {
+		rc = -ENAMETOOLONG;
+		goto seg_list_del;
+	}
+	strlcpy(local_buf, buf, i + 1);
+	dev_info->num_of_segments = num_of_segments;
+	rc = dcssblk_is_continuous(dev_info);
+	if (rc < 0)
+		goto seg_list_del;
+
+	dev_info->start = dcssblk_find_lowest_addr(dev_info);
+	dev_info->end = dcssblk_find_highest_addr(dev_info);
+
+	dev_set_name(&dev_info->dev, "%s", dev_info->segment_name);
+	dev_info->dev.release = dcssblk_release_segment;
+	dev_info->dev.groups = dcssblk_dev_attr_groups;
+	INIT_LIST_HEAD(&dev_info->lh);
+	dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
+	if (dev_info->gd == NULL) {
+		rc = -ENOMEM;
+		goto seg_list_del;
+	}
+	dev_info->gd->major = dcssblk_major;
+	dev_info->gd->fops = &dcssblk_devops;
+	dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
+	dev_info->gd->queue = dev_info->dcssblk_queue;
+	dev_info->gd->private_data = dev_info;
+	blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
+	blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
+	blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->dcssblk_queue);
+
+	seg_byte_size = (dev_info->end - dev_info->start + 1);
+	set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
+	pr_info("Loaded %s with total size %lu bytes and capacity %lu "
+		"sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9);
+
+	dev_info->save_pending = 0;
+	dev_info->is_shared = 1;
+	dev_info->dev.parent = dcssblk_root_dev;
+
+	/*
+	 *get minor, add to list
+	 */
+	down_write(&dcssblk_devices_sem);
+	if (dcssblk_get_segment_by_name(local_buf)) {
+		rc = -EEXIST;
+		goto release_gd;
+	}
+	rc = dcssblk_assign_free_minor(dev_info);
+	if (rc)
+		goto release_gd;
+	sprintf(dev_info->gd->disk_name, "dcssblk%d",
+		dev_info->gd->first_minor);
+	list_add_tail(&dev_info->lh, &dcssblk_devices);
+
+	if (!try_module_get(THIS_MODULE)) {
+		rc = -ENODEV;
+		goto dev_list_del;
+	}
+	/*
+	 * register the device
+	 */
+	rc = device_register(&dev_info->dev);
+	if (rc)
+		goto put_dev;
+
+	dev_info->dax_dev = alloc_dax(dev_info, dev_info->gd->disk_name,
+			&dcssblk_dax_ops);
+	if (!dev_info->dax_dev) {
+		rc = -ENOMEM;
+		goto put_dev;
+	}
+
+	get_device(&dev_info->dev);
+	device_add_disk(&dev_info->dev, dev_info->gd, NULL);
+
+	switch (dev_info->segment_type) {
+		case SEG_TYPE_SR:
+		case SEG_TYPE_ER:
+		case SEG_TYPE_SC:
+			set_disk_ro(dev_info->gd,1);
+			break;
+		default:
+			set_disk_ro(dev_info->gd,0);
+			break;
+	}
+	up_write(&dcssblk_devices_sem);
+	rc = count;
+	goto out;
+
+put_dev:
+	list_del(&dev_info->lh);
+	blk_cleanup_queue(dev_info->dcssblk_queue);
+	dev_info->gd->queue = NULL;
+	put_disk(dev_info->gd);
+	list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
+		segment_unload(seg_info->segment_name);
+	}
+	put_device(&dev_info->dev);
+	up_write(&dcssblk_devices_sem);
+	goto out;
+dev_list_del:
+	list_del(&dev_info->lh);
+release_gd:
+	blk_cleanup_queue(dev_info->dcssblk_queue);
+	dev_info->gd->queue = NULL;
+	put_disk(dev_info->gd);
+	up_write(&dcssblk_devices_sem);
+seg_list_del:
+	if (dev_info == NULL)
+		goto out;
+	list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
+		list_del(&seg_info->lh);
+		segment_unload(seg_info->segment_name);
+		kfree(seg_info);
+	}
+	kfree(dev_info);
+out:
+	kfree(local_buf);
+out_nobuf:
+	return rc;
+}
+
+/*
+ * device attribute for removing devices
+ */
+static ssize_t
+dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry;
+	int rc, i;
+	char *local_buf;
+
+	if (dev != dcssblk_root_dev) {
+		return -EINVAL;
+	}
+	local_buf = kmalloc(count + 1, GFP_KERNEL);
+	if (local_buf == NULL) {
+		return -ENOMEM;
+	}
+	/*
+	 * parse input
+	 */
+	for (i = 0; (i < count && (*(buf+i)!='\0') && (*(buf+i)!='\n')); i++) {
+		local_buf[i] = toupper(buf[i]);
+	}
+	local_buf[i] = '\0';
+	if ((i == 0) || (i > 8)) {
+		rc = -ENAMETOOLONG;
+		goto out_buf;
+	}
+
+	down_write(&dcssblk_devices_sem);
+	dev_info = dcssblk_get_device_by_name(local_buf);
+	if (dev_info == NULL) {
+		up_write(&dcssblk_devices_sem);
+		pr_warn("Device %s cannot be removed because it is not a known device\n",
+			local_buf);
+		rc = -ENODEV;
+		goto out_buf;
+	}
+	if (atomic_read(&dev_info->use_count) != 0) {
+		up_write(&dcssblk_devices_sem);
+		pr_warn("Device %s cannot be removed while it is in use\n",
+			local_buf);
+		rc = -EBUSY;
+		goto out_buf;
+	}
+
+	list_del(&dev_info->lh);
+	kill_dax(dev_info->dax_dev);
+	put_dax(dev_info->dax_dev);
+	del_gendisk(dev_info->gd);
+	blk_cleanup_queue(dev_info->dcssblk_queue);
+	dev_info->gd->queue = NULL;
+	put_disk(dev_info->gd);
+
+	/* unload all related segments */
+	list_for_each_entry(entry, &dev_info->seg_list, lh)
+		segment_unload(entry->segment_name);
+
+	up_write(&dcssblk_devices_sem);
+
+	device_unregister(&dev_info->dev);
+	put_device(&dev_info->dev);
+
+	rc = count;
+out_buf:
+	kfree(local_buf);
+	return rc;
+}
+
+static int
+dcssblk_open(struct block_device *bdev, fmode_t mode)
+{
+	struct dcssblk_dev_info *dev_info;
+	int rc;
+
+	dev_info = bdev->bd_disk->private_data;
+	if (NULL == dev_info) {
+		rc = -ENODEV;
+		goto out;
+	}
+	atomic_inc(&dev_info->use_count);
+	bdev->bd_block_size = 4096;
+	rc = 0;
+out:
+	return rc;
+}
+
+static void
+dcssblk_release(struct gendisk *disk, fmode_t mode)
+{
+	struct dcssblk_dev_info *dev_info = disk->private_data;
+	struct segment_info *entry;
+
+	if (!dev_info) {
+		WARN_ON(1);
+		return;
+	}
+	down_write(&dcssblk_devices_sem);
+	if (atomic_dec_and_test(&dev_info->use_count)
+	    && (dev_info->save_pending)) {
+		pr_info("Device %s has become idle and is being saved "
+			"now\n", dev_info->segment_name);
+		list_for_each_entry(entry, &dev_info->seg_list, lh) {
+			if (entry->segment_type == SEG_TYPE_EN ||
+			    entry->segment_type == SEG_TYPE_SN)
+				pr_warn("DCSS %s is of type SN or EN and cannot"
+					" be saved\n", entry->segment_name);
+			else
+				segment_save(entry->segment_name);
+		}
+		dev_info->save_pending = 0;
+	}
+	up_write(&dcssblk_devices_sem);
+}
+
+static blk_qc_t
+dcssblk_make_request(struct request_queue *q, struct bio *bio)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	unsigned long index;
+	unsigned long page_addr;
+	unsigned long source_addr;
+	unsigned long bytes_done;
+
+	blk_queue_split(q, &bio);
+
+	bytes_done = 0;
+	dev_info = bio->bi_disk->private_data;
+	if (dev_info == NULL)
+		goto fail;
+	if ((bio->bi_iter.bi_sector & 7) != 0 ||
+	    (bio->bi_iter.bi_size & 4095) != 0)
+		/* Request is not page-aligned. */
+		goto fail;
+	if (bio_end_sector(bio) > get_capacity(bio->bi_disk)) {
+		/* Request beyond end of DCSS segment. */
+		goto fail;
+	}
+	/* verify data transfer direction */
+	if (dev_info->is_shared) {
+		switch (dev_info->segment_type) {
+		case SEG_TYPE_SR:
+		case SEG_TYPE_ER:
+		case SEG_TYPE_SC:
+			/* cannot write to these segments */
+			if (bio_data_dir(bio) == WRITE) {
+				pr_warn("Writing to %s failed because it is a read-only device\n",
+					dev_name(&dev_info->dev));
+				goto fail;
+			}
+		}
+	}
+
+	index = (bio->bi_iter.bi_sector >> 3);
+	bio_for_each_segment(bvec, bio, iter) {
+		page_addr = (unsigned long)
+			page_address(bvec.bv_page) + bvec.bv_offset;
+		source_addr = dev_info->start + (index<<12) + bytes_done;
+		if (unlikely((page_addr & 4095) != 0) || (bvec.bv_len & 4095) != 0)
+			// More paranoia.
+			goto fail;
+		if (bio_data_dir(bio) == READ) {
+			memcpy((void*)page_addr, (void*)source_addr,
+				bvec.bv_len);
+		} else {
+			memcpy((void*)source_addr, (void*)page_addr,
+				bvec.bv_len);
+		}
+		bytes_done += bvec.bv_len;
+	}
+	bio_endio(bio);
+	return BLK_QC_T_NONE;
+fail:
+	bio_io_error(bio);
+	return BLK_QC_T_NONE;
+}
+
+static long
+__dcssblk_direct_access(struct dcssblk_dev_info *dev_info, pgoff_t pgoff,
+		long nr_pages, void **kaddr, pfn_t *pfn)
+{
+	resource_size_t offset = pgoff * PAGE_SIZE;
+	unsigned long dev_sz;
+
+	dev_sz = dev_info->end - dev_info->start + 1;
+	if (kaddr)
+		*kaddr = (void *) dev_info->start + offset;
+	if (pfn)
+		*pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset),
+				PFN_DEV|PFN_SPECIAL);
+
+	return (dev_sz - offset) / PAGE_SIZE;
+}
+
+static long
+dcssblk_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
+		long nr_pages, void **kaddr, pfn_t *pfn)
+{
+	struct dcssblk_dev_info *dev_info = dax_get_private(dax_dev);
+
+	return __dcssblk_direct_access(dev_info, pgoff, nr_pages, kaddr, pfn);
+}
+
+static void
+dcssblk_check_params(void)
+{
+	int rc, i, j, k;
+	char buf[DCSSBLK_PARM_LEN + 1];
+	struct dcssblk_dev_info *dev_info;
+
+	for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
+	     i++) {
+		for (j = i; (j < DCSSBLK_PARM_LEN) &&
+			    (dcssblk_segments[j] != ',')  &&
+			    (dcssblk_segments[j] != '\0') &&
+			    (dcssblk_segments[j] != '('); j++)
+		{
+			buf[j-i] = dcssblk_segments[j];
+		}
+		buf[j-i] = '\0';
+		rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
+		if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
+			for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
+				buf[k] = toupper(buf[k]);
+			buf[k] = '\0';
+			if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
+				down_read(&dcssblk_devices_sem);
+				dev_info = dcssblk_get_device_by_name(buf);
+				up_read(&dcssblk_devices_sem);
+				if (dev_info)
+					dcssblk_shared_store(&dev_info->dev,
+							     NULL, "0\n", 2);
+			}
+		}
+		while ((dcssblk_segments[j] != ',') &&
+		       (dcssblk_segments[j] != '\0'))
+		{
+			j++;
+		}
+		if (dcssblk_segments[j] == '\0')
+			break;
+		i = j;
+	}
+}
+
+/*
+ * Suspend / Resume
+ */
+static int dcssblk_freeze(struct device *dev)
+{
+	struct dcssblk_dev_info *dev_info;
+	int rc = 0;
+
+	list_for_each_entry(dev_info, &dcssblk_devices, lh) {
+		switch (dev_info->segment_type) {
+			case SEG_TYPE_SR:
+			case SEG_TYPE_ER:
+			case SEG_TYPE_SC:
+				if (!dev_info->is_shared)
+					rc = -EINVAL;
+				break;
+			default:
+				rc = -EINVAL;
+				break;
+		}
+		if (rc)
+			break;
+	}
+	if (rc)
+		pr_err("Suspending the system failed because DCSS device %s "
+		       "is writable\n",
+		       dev_info->segment_name);
+	return rc;
+}
+
+static int dcssblk_restore(struct device *dev)
+{
+	struct dcssblk_dev_info *dev_info;
+	struct segment_info *entry;
+	unsigned long start, end;
+	int rc = 0;
+
+	list_for_each_entry(dev_info, &dcssblk_devices, lh) {
+		list_for_each_entry(entry, &dev_info->seg_list, lh) {
+			segment_unload(entry->segment_name);
+			rc = segment_load(entry->segment_name, SEGMENT_SHARED,
+					  &start, &end);
+			if (rc < 0) {
+// TODO in_use check ?
+				segment_warning(rc, entry->segment_name);
+				goto out_panic;
+			}
+			if (start != entry->start || end != entry->end) {
+				pr_err("The address range of DCSS %s changed "
+				       "while the system was suspended\n",
+				       entry->segment_name);
+				goto out_panic;
+			}
+		}
+	}
+	return 0;
+out_panic:
+	panic("fatal dcssblk resume error\n");
+}
+
+static int dcssblk_thaw(struct device *dev)
+{
+	return 0;
+}
+
+static const struct dev_pm_ops dcssblk_pm_ops = {
+	.freeze		= dcssblk_freeze,
+	.thaw		= dcssblk_thaw,
+	.restore	= dcssblk_restore,
+};
+
+static struct platform_driver dcssblk_pdrv = {
+	.driver = {
+		.name	= "dcssblk",
+		.pm	= &dcssblk_pm_ops,
+	},
+};
+
+static struct platform_device *dcssblk_pdev;
+
+
+/*
+ * The init/exit functions.
+ */
+static void __exit
+dcssblk_exit(void)
+{
+	platform_device_unregister(dcssblk_pdev);
+	platform_driver_unregister(&dcssblk_pdrv);
+	root_device_unregister(dcssblk_root_dev);
+	unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
+}
+
+static int __init
+dcssblk_init(void)
+{
+	int rc;
+
+	rc = platform_driver_register(&dcssblk_pdrv);
+	if (rc)
+		return rc;
+
+	dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL,
+							0);
+	if (IS_ERR(dcssblk_pdev)) {
+		rc = PTR_ERR(dcssblk_pdev);
+		goto out_pdrv;
+	}
+
+	dcssblk_root_dev = root_device_register("dcssblk");
+	if (IS_ERR(dcssblk_root_dev)) {
+		rc = PTR_ERR(dcssblk_root_dev);
+		goto out_pdev;
+	}
+	rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
+	if (rc)
+		goto out_root;
+	rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
+	if (rc)
+		goto out_root;
+	rc = register_blkdev(0, DCSSBLK_NAME);
+	if (rc < 0)
+		goto out_root;
+	dcssblk_major = rc;
+	init_rwsem(&dcssblk_devices_sem);
+
+	dcssblk_check_params();
+	return 0;
+
+out_root:
+	root_device_unregister(dcssblk_root_dev);
+out_pdev:
+	platform_device_unregister(dcssblk_pdev);
+out_pdrv:
+	platform_driver_unregister(&dcssblk_pdrv);
+	return rc;
+}
+
+module_init(dcssblk_init);
+module_exit(dcssblk_exit);
+
+module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
+MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
+		 "comma-separated list, names in each set separated "
+		 "by commas are separated by colons, each set contains "
+		 "names of contiguous segments and each name max. 8 chars.\n"
+		 "Adding \"(local)\" to the end of each set equals echoing 0 "
+		 "to /sys/devices/dcssblk/<device name>/shared after loading "
+		 "the contiguous segments - \n"
+		 "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
new file mode 100644
index 000000000..e01889394
--- /dev/null
+++ b/drivers/s390/block/scm_blk.c
@@ -0,0 +1,591 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Block driver for s390 storage class memory.
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
+ */
+
+#define KMSG_COMPONENT "scm_block"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/genhd.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <asm/eadm.h>
+#include "scm_blk.h"
+
+debug_info_t *scm_debug;
+static int scm_major;
+static mempool_t *aidaw_pool;
+static DEFINE_SPINLOCK(list_lock);
+static LIST_HEAD(inactive_requests);
+static unsigned int nr_requests = 64;
+static unsigned int nr_requests_per_io = 8;
+static atomic_t nr_devices = ATOMIC_INIT(0);
+module_param(nr_requests, uint, S_IRUGO);
+MODULE_PARM_DESC(nr_requests, "Number of parallel requests.");
+
+module_param(nr_requests_per_io, uint, S_IRUGO);
+MODULE_PARM_DESC(nr_requests_per_io, "Number of requests per IO.");
+
+MODULE_DESCRIPTION("Block driver for s390 storage class memory.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("scm:scmdev*");
+
+static void __scm_free_rq(struct scm_request *scmrq)
+{
+	struct aob_rq_header *aobrq = to_aobrq(scmrq);
+
+	free_page((unsigned long) scmrq->aob);
+	kfree(scmrq->request);
+	kfree(aobrq);
+}
+
+static void scm_free_rqs(void)
+{
+	struct list_head *iter, *safe;
+	struct scm_request *scmrq;
+
+	spin_lock_irq(&list_lock);
+	list_for_each_safe(iter, safe, &inactive_requests) {
+		scmrq = list_entry(iter, struct scm_request, list);
+		list_del(&scmrq->list);
+		__scm_free_rq(scmrq);
+	}
+	spin_unlock_irq(&list_lock);
+
+	mempool_destroy(aidaw_pool);
+}
+
+static int __scm_alloc_rq(void)
+{
+	struct aob_rq_header *aobrq;
+	struct scm_request *scmrq;
+
+	aobrq = kzalloc(sizeof(*aobrq) + sizeof(*scmrq), GFP_KERNEL);
+	if (!aobrq)
+		return -ENOMEM;
+
+	scmrq = (void *) aobrq->data;
+	scmrq->aob = (void *) get_zeroed_page(GFP_DMA);
+	if (!scmrq->aob)
+		goto free;
+
+	scmrq->request = kcalloc(nr_requests_per_io, sizeof(scmrq->request[0]),
+				 GFP_KERNEL);
+	if (!scmrq->request)
+		goto free;
+
+	INIT_LIST_HEAD(&scmrq->list);
+	spin_lock_irq(&list_lock);
+	list_add(&scmrq->list, &inactive_requests);
+	spin_unlock_irq(&list_lock);
+
+	return 0;
+free:
+	__scm_free_rq(scmrq);
+	return -ENOMEM;
+}
+
+static int scm_alloc_rqs(unsigned int nrqs)
+{
+	int ret = 0;
+
+	aidaw_pool = mempool_create_page_pool(max(nrqs/8, 1U), 0);
+	if (!aidaw_pool)
+		return -ENOMEM;
+
+	while (nrqs-- && !ret)
+		ret = __scm_alloc_rq();
+
+	return ret;
+}
+
+static struct scm_request *scm_request_fetch(void)
+{
+	struct scm_request *scmrq = NULL;
+
+	spin_lock_irq(&list_lock);
+	if (list_empty(&inactive_requests))
+		goto out;
+	scmrq = list_first_entry(&inactive_requests, struct scm_request, list);
+	list_del(&scmrq->list);
+out:
+	spin_unlock_irq(&list_lock);
+	return scmrq;
+}
+
+static void scm_request_done(struct scm_request *scmrq)
+{
+	unsigned long flags;
+	struct msb *msb;
+	u64 aidaw;
+	int i;
+
+	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
+		msb = &scmrq->aob->msb[i];
+		aidaw = msb->data_addr;
+
+		if ((msb->flags & MSB_FLAG_IDA) && aidaw &&
+		    IS_ALIGNED(aidaw, PAGE_SIZE))
+			mempool_free(virt_to_page(aidaw), aidaw_pool);
+	}
+
+	spin_lock_irqsave(&list_lock, flags);
+	list_add(&scmrq->list, &inactive_requests);
+	spin_unlock_irqrestore(&list_lock, flags);
+}
+
+static bool scm_permit_request(struct scm_blk_dev *bdev, struct request *req)
+{
+	return rq_data_dir(req) != WRITE || bdev->state != SCM_WR_PROHIBIT;
+}
+
+static inline struct aidaw *scm_aidaw_alloc(void)
+{
+	struct page *page = mempool_alloc(aidaw_pool, GFP_ATOMIC);
+
+	return page ? page_address(page) : NULL;
+}
+
+static inline unsigned long scm_aidaw_bytes(struct aidaw *aidaw)
+{
+	unsigned long _aidaw = (unsigned long) aidaw;
+	unsigned long bytes = ALIGN(_aidaw, PAGE_SIZE) - _aidaw;
+
+	return (bytes / sizeof(*aidaw)) * PAGE_SIZE;
+}
+
+struct aidaw *scm_aidaw_fetch(struct scm_request *scmrq, unsigned int bytes)
+{
+	struct aidaw *aidaw;
+
+	if (scm_aidaw_bytes(scmrq->next_aidaw) >= bytes)
+		return scmrq->next_aidaw;
+
+	aidaw = scm_aidaw_alloc();
+	if (aidaw)
+		memset(aidaw, 0, PAGE_SIZE);
+	return aidaw;
+}
+
+static int scm_request_prepare(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+	struct scm_device *scmdev = bdev->gendisk->private_data;
+	int pos = scmrq->aob->request.msb_count;
+	struct msb *msb = &scmrq->aob->msb[pos];
+	struct request *req = scmrq->request[pos];
+	struct req_iterator iter;
+	struct aidaw *aidaw;
+	struct bio_vec bv;
+
+	aidaw = scm_aidaw_fetch(scmrq, blk_rq_bytes(req));
+	if (!aidaw)
+		return -ENOMEM;
+
+	msb->bs = MSB_BS_4K;
+	scmrq->aob->request.msb_count++;
+	msb->scm_addr = scmdev->address + ((u64) blk_rq_pos(req) << 9);
+	msb->oc = (rq_data_dir(req) == READ) ? MSB_OC_READ : MSB_OC_WRITE;
+	msb->flags |= MSB_FLAG_IDA;
+	msb->data_addr = (u64) aidaw;
+
+	rq_for_each_segment(bv, req, iter) {
+		WARN_ON(bv.bv_offset);
+		msb->blk_count += bv.bv_len >> 12;
+		aidaw->data_addr = (u64) page_address(bv.bv_page);
+		aidaw++;
+	}
+
+	scmrq->next_aidaw = aidaw;
+	return 0;
+}
+
+static inline void scm_request_set(struct scm_request *scmrq,
+				   struct request *req)
+{
+	scmrq->request[scmrq->aob->request.msb_count] = req;
+}
+
+static inline void scm_request_init(struct scm_blk_dev *bdev,
+				    struct scm_request *scmrq)
+{
+	struct aob_rq_header *aobrq = to_aobrq(scmrq);
+	struct aob *aob = scmrq->aob;
+
+	memset(scmrq->request, 0,
+	       nr_requests_per_io * sizeof(scmrq->request[0]));
+	memset(aob, 0, sizeof(*aob));
+	aobrq->scmdev = bdev->scmdev;
+	aob->request.cmd_code = ARQB_CMD_MOVE;
+	aob->request.data = (u64) aobrq;
+	scmrq->bdev = bdev;
+	scmrq->retries = 4;
+	scmrq->error = BLK_STS_OK;
+	/* We don't use all msbs - place aidaws at the end of the aob page. */
+	scmrq->next_aidaw = (void *) &aob->msb[nr_requests_per_io];
+}
+
+static void scm_request_requeue(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+	int i;
+
+	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)
+		blk_mq_requeue_request(scmrq->request[i], false);
+
+	atomic_dec(&bdev->queued_reqs);
+	scm_request_done(scmrq);
+	blk_mq_kick_requeue_list(bdev->rq);
+}
+
+static void scm_request_finish(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+	blk_status_t *error;
+	int i;
+
+	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
+		error = blk_mq_rq_to_pdu(scmrq->request[i]);
+		*error = scmrq->error;
+		blk_mq_complete_request(scmrq->request[i]);
+	}
+
+	atomic_dec(&bdev->queued_reqs);
+	scm_request_done(scmrq);
+}
+
+static void scm_request_start(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+
+	atomic_inc(&bdev->queued_reqs);
+	if (eadm_start_aob(scmrq->aob)) {
+		SCM_LOG(5, "no subchannel");
+		scm_request_requeue(scmrq);
+	}
+}
+
+struct scm_queue {
+	struct scm_request *scmrq;
+	spinlock_t lock;
+};
+
+static blk_status_t scm_blk_request(struct blk_mq_hw_ctx *hctx,
+			   const struct blk_mq_queue_data *qd)
+{
+	struct scm_device *scmdev = hctx->queue->queuedata;
+	struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
+	struct scm_queue *sq = hctx->driver_data;
+	struct request *req = qd->rq;
+	struct scm_request *scmrq;
+
+	spin_lock(&sq->lock);
+	if (!scm_permit_request(bdev, req)) {
+		spin_unlock(&sq->lock);
+		return BLK_STS_RESOURCE;
+	}
+
+	scmrq = sq->scmrq;
+	if (!scmrq) {
+		scmrq = scm_request_fetch();
+		if (!scmrq) {
+			SCM_LOG(5, "no request");
+			spin_unlock(&sq->lock);
+			return BLK_STS_RESOURCE;
+		}
+		scm_request_init(bdev, scmrq);
+		sq->scmrq = scmrq;
+	}
+	scm_request_set(scmrq, req);
+
+	if (scm_request_prepare(scmrq)) {
+		SCM_LOG(5, "aidaw alloc failed");
+		scm_request_set(scmrq, NULL);
+
+		if (scmrq->aob->request.msb_count)
+			scm_request_start(scmrq);
+
+		sq->scmrq = NULL;
+		spin_unlock(&sq->lock);
+		return BLK_STS_RESOURCE;
+	}
+	blk_mq_start_request(req);
+
+	if (qd->last || scmrq->aob->request.msb_count == nr_requests_per_io) {
+		scm_request_start(scmrq);
+		sq->scmrq = NULL;
+	}
+	spin_unlock(&sq->lock);
+	return BLK_STS_OK;
+}
+
+static int scm_blk_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+			     unsigned int idx)
+{
+	struct scm_queue *qd = kzalloc(sizeof(*qd), GFP_KERNEL);
+
+	if (!qd)
+		return -ENOMEM;
+
+	spin_lock_init(&qd->lock);
+	hctx->driver_data = qd;
+
+	return 0;
+}
+
+static void scm_blk_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
+{
+	struct scm_queue *qd = hctx->driver_data;
+
+	WARN_ON(qd->scmrq);
+	kfree(hctx->driver_data);
+	hctx->driver_data = NULL;
+}
+
+static void __scmrq_log_error(struct scm_request *scmrq)
+{
+	struct aob *aob = scmrq->aob;
+
+	if (scmrq->error == BLK_STS_TIMEOUT)
+		SCM_LOG(1, "Request timeout");
+	else {
+		SCM_LOG(1, "Request error");
+		SCM_LOG_HEX(1, &aob->response, sizeof(aob->response));
+	}
+	if (scmrq->retries)
+		SCM_LOG(1, "Retry request");
+	else
+		pr_err("An I/O operation to SCM failed with rc=%d\n",
+		       scmrq->error);
+}
+
+static void scm_blk_handle_error(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+	unsigned long flags;
+
+	if (scmrq->error != BLK_STS_IOERR)
+		goto restart;
+
+	/* For -EIO the response block is valid. */
+	switch (scmrq->aob->response.eqc) {
+	case EQC_WR_PROHIBIT:
+		spin_lock_irqsave(&bdev->lock, flags);
+		if (bdev->state != SCM_WR_PROHIBIT)
+			pr_info("%lx: Write access to the SCM increment is suspended\n",
+				(unsigned long) bdev->scmdev->address);
+		bdev->state = SCM_WR_PROHIBIT;
+		spin_unlock_irqrestore(&bdev->lock, flags);
+		goto requeue;
+	default:
+		break;
+	}
+
+restart:
+	if (!eadm_start_aob(scmrq->aob))
+		return;
+
+requeue:
+	scm_request_requeue(scmrq);
+}
+
+void scm_blk_irq(struct scm_device *scmdev, void *data, blk_status_t error)
+{
+	struct scm_request *scmrq = data;
+
+	scmrq->error = error;
+	if (error) {
+		__scmrq_log_error(scmrq);
+		if (scmrq->retries-- > 0) {
+			scm_blk_handle_error(scmrq);
+			return;
+		}
+	}
+
+	scm_request_finish(scmrq);
+}
+
+static void scm_blk_request_done(struct request *req)
+{
+	blk_status_t *error = blk_mq_rq_to_pdu(req);
+
+	blk_mq_end_request(req, *error);
+}
+
+static const struct block_device_operations scm_blk_devops = {
+	.owner = THIS_MODULE,
+};
+
+static const struct blk_mq_ops scm_mq_ops = {
+	.queue_rq = scm_blk_request,
+	.complete = scm_blk_request_done,
+	.init_hctx = scm_blk_init_hctx,
+	.exit_hctx = scm_blk_exit_hctx,
+};
+
+int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
+{
+	unsigned int devindex, nr_max_blk;
+	struct request_queue *rq;
+	int len, ret;
+
+	devindex = atomic_inc_return(&nr_devices) - 1;
+	/* scma..scmz + scmaa..scmzz */
+	if (devindex > 701) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	bdev->scmdev = scmdev;
+	bdev->state = SCM_OPER;
+	spin_lock_init(&bdev->lock);
+	atomic_set(&bdev->queued_reqs, 0);
+
+	bdev->tag_set.ops = &scm_mq_ops;
+	bdev->tag_set.cmd_size = sizeof(blk_status_t);
+	bdev->tag_set.nr_hw_queues = nr_requests;
+	bdev->tag_set.queue_depth = nr_requests_per_io * nr_requests;
+	bdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+	bdev->tag_set.numa_node = NUMA_NO_NODE;
+
+	ret = blk_mq_alloc_tag_set(&bdev->tag_set);
+	if (ret)
+		goto out;
+
+	rq = blk_mq_init_queue(&bdev->tag_set);
+	if (IS_ERR(rq)) {
+		ret = PTR_ERR(rq);
+		goto out_tag;
+	}
+	bdev->rq = rq;
+	nr_max_blk = min(scmdev->nr_max_block,
+			 (unsigned int) (PAGE_SIZE / sizeof(struct aidaw)));
+
+	blk_queue_logical_block_size(rq, 1 << 12);
+	blk_queue_max_hw_sectors(rq, nr_max_blk << 3); /* 8 * 512 = blk_size */
+	blk_queue_max_segments(rq, nr_max_blk);
+	blk_queue_flag_set(QUEUE_FLAG_NONROT, rq);
+	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, rq);
+
+	bdev->gendisk = alloc_disk(SCM_NR_PARTS);
+	if (!bdev->gendisk) {
+		ret = -ENOMEM;
+		goto out_queue;
+	}
+	rq->queuedata = scmdev;
+	bdev->gendisk->private_data = scmdev;
+	bdev->gendisk->fops = &scm_blk_devops;
+	bdev->gendisk->queue = rq;
+	bdev->gendisk->major = scm_major;
+	bdev->gendisk->first_minor = devindex * SCM_NR_PARTS;
+
+	len = snprintf(bdev->gendisk->disk_name, DISK_NAME_LEN, "scm");
+	if (devindex > 25) {
+		len += snprintf(bdev->gendisk->disk_name + len,
+				DISK_NAME_LEN - len, "%c",
+				'a' + (devindex / 26) - 1);
+		devindex = devindex % 26;
+	}
+	snprintf(bdev->gendisk->disk_name + len, DISK_NAME_LEN - len, "%c",
+		 'a' + devindex);
+
+	/* 512 byte sectors */
+	set_capacity(bdev->gendisk, scmdev->size >> 9);
+	device_add_disk(&scmdev->dev, bdev->gendisk, NULL);
+	return 0;
+
+out_queue:
+	blk_cleanup_queue(rq);
+out_tag:
+	blk_mq_free_tag_set(&bdev->tag_set);
+out:
+	atomic_dec(&nr_devices);
+	return ret;
+}
+
+void scm_blk_dev_cleanup(struct scm_blk_dev *bdev)
+{
+	del_gendisk(bdev->gendisk);
+	blk_cleanup_queue(bdev->gendisk->queue);
+	blk_mq_free_tag_set(&bdev->tag_set);
+	put_disk(bdev->gendisk);
+}
+
+void scm_blk_set_available(struct scm_blk_dev *bdev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&bdev->lock, flags);
+	if (bdev->state == SCM_WR_PROHIBIT)
+		pr_info("%lx: Write access to the SCM increment is restored\n",
+			(unsigned long) bdev->scmdev->address);
+	bdev->state = SCM_OPER;
+	spin_unlock_irqrestore(&bdev->lock, flags);
+}
+
+static bool __init scm_blk_params_valid(void)
+{
+	if (!nr_requests_per_io || nr_requests_per_io > 64)
+		return false;
+
+	return true;
+}
+
+static int __init scm_blk_init(void)
+{
+	int ret = -EINVAL;
+
+	if (!scm_blk_params_valid())
+		goto out;
+
+	ret = register_blkdev(0, "scm");
+	if (ret < 0)
+		goto out;
+
+	scm_major = ret;
+	ret = scm_alloc_rqs(nr_requests);
+	if (ret)
+		goto out_free;
+
+	scm_debug = debug_register("scm_log", 16, 1, 16);
+	if (!scm_debug) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	debug_register_view(scm_debug, &debug_hex_ascii_view);
+	debug_set_level(scm_debug, 2);
+
+	ret = scm_drv_init();
+	if (ret)
+		goto out_dbf;
+
+	return ret;
+
+out_dbf:
+	debug_unregister(scm_debug);
+out_free:
+	scm_free_rqs();
+	unregister_blkdev(scm_major, "scm");
+out:
+	return ret;
+}
+module_init(scm_blk_init);
+
+static void __exit scm_blk_cleanup(void)
+{
+	scm_drv_cleanup();
+	debug_unregister(scm_debug);
+	scm_free_rqs();
+	unregister_blkdev(scm_major, "scm");
+}
+module_exit(scm_blk_cleanup);
diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h
new file mode 100644
index 000000000..a05a4297c
--- /dev/null
+++ b/drivers/s390/block/scm_blk.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef SCM_BLK_H
+#define SCM_BLK_H
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/genhd.h>
+#include <linux/list.h>
+
+#include <asm/debug.h>
+#include <asm/eadm.h>
+
+#define SCM_NR_PARTS 8
+#define SCM_QUEUE_DELAY 5
+
+struct scm_blk_dev {
+	struct request_queue *rq;
+	struct gendisk *gendisk;
+	struct blk_mq_tag_set tag_set;
+	struct scm_device *scmdev;
+	spinlock_t lock;
+	atomic_t queued_reqs;
+	enum {SCM_OPER, SCM_WR_PROHIBIT} state;
+	struct list_head finished_requests;
+};
+
+struct scm_request {
+	struct scm_blk_dev *bdev;
+	struct aidaw *next_aidaw;
+	struct request **request;
+	struct aob *aob;
+	struct list_head list;
+	u8 retries;
+	blk_status_t error;
+};
+
+#define to_aobrq(rq) container_of((void *) rq, struct aob_rq_header, data)
+
+int scm_blk_dev_setup(struct scm_blk_dev *, struct scm_device *);
+void scm_blk_dev_cleanup(struct scm_blk_dev *);
+void scm_blk_set_available(struct scm_blk_dev *);
+void scm_blk_irq(struct scm_device *, void *, blk_status_t);
+
+struct aidaw *scm_aidaw_fetch(struct scm_request *scmrq, unsigned int bytes);
+
+int scm_drv_init(void);
+void scm_drv_cleanup(void);
+
+extern debug_info_t *scm_debug;
+
+#define SCM_LOG(imp, txt) do {					\
+		debug_text_event(scm_debug, imp, txt);		\
+	} while (0)
+
+static inline void SCM_LOG_HEX(int level, void *data, int length)
+{
+	debug_event(scm_debug, level, data, length);
+}
+
+static inline void SCM_LOG_STATE(int level, struct scm_device *scmdev)
+{
+	struct {
+		u64 address;
+		u8 oper_state;
+		u8 rank;
+	} __packed data = {
+		.address = scmdev->address,
+		.oper_state = scmdev->attrs.oper_state,
+		.rank = scmdev->attrs.rank,
+	};
+
+	SCM_LOG_HEX(level, &data, sizeof(data));
+}
+
+#endif /* SCM_BLK_H */
diff --git a/drivers/s390/block/scm_drv.c b/drivers/s390/block/scm_drv.c
new file mode 100644
index 000000000..3134fd6e0
--- /dev/null
+++ b/drivers/s390/block/scm_drv.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device driver for s390 storage class memory.
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
+ */
+
+#define KMSG_COMPONENT "scm_block"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/eadm.h>
+#include "scm_blk.h"
+
+static void scm_notify(struct scm_device *scmdev, enum scm_event event)
+{
+	struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
+
+	switch (event) {
+	case SCM_CHANGE:
+		pr_info("%lx: The capabilities of the SCM increment changed\n",
+			(unsigned long) scmdev->address);
+		SCM_LOG(2, "State changed");
+		SCM_LOG_STATE(2, scmdev);
+		break;
+	case SCM_AVAIL:
+		SCM_LOG(2, "Increment available");
+		SCM_LOG_STATE(2, scmdev);
+		scm_blk_set_available(bdev);
+		break;
+	}
+}
+
+static int scm_probe(struct scm_device *scmdev)
+{
+	struct scm_blk_dev *bdev;
+	int ret;
+
+	SCM_LOG(2, "probe");
+	SCM_LOG_STATE(2, scmdev);
+
+	if (scmdev->attrs.oper_state != OP_STATE_GOOD)
+		return -EINVAL;
+
+	bdev = kzalloc(sizeof(*bdev), GFP_KERNEL);
+	if (!bdev)
+		return -ENOMEM;
+
+	dev_set_drvdata(&scmdev->dev, bdev);
+	ret = scm_blk_dev_setup(bdev, scmdev);
+	if (ret) {
+		dev_set_drvdata(&scmdev->dev, NULL);
+		kfree(bdev);
+		goto out;
+	}
+
+out:
+	return ret;
+}
+
+static int scm_remove(struct scm_device *scmdev)
+{
+	struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
+
+	scm_blk_dev_cleanup(bdev);
+	dev_set_drvdata(&scmdev->dev, NULL);
+	kfree(bdev);
+
+	return 0;
+}
+
+static struct scm_driver scm_drv = {
+	.drv = {
+		.name = "scm_block",
+		.owner = THIS_MODULE,
+	},
+	.notify = scm_notify,
+	.probe = scm_probe,
+	.remove = scm_remove,
+	.handler = scm_blk_irq,
+};
+
+int __init scm_drv_init(void)
+{
+	return scm_driver_register(&scm_drv);
+}
+
+void scm_drv_cleanup(void)
+{
+	scm_driver_unregister(&scm_drv);
+}
diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
new file mode 100644
index 000000000..3df5d68d0
--- /dev/null
+++ b/drivers/s390/block/xpram.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xpram.c -- the S/390 expanded memory RAM-disk
+ *           
+ * significant parts of this code are based on
+ * the sbull device driver presented in
+ * A. Rubini: Linux Device Drivers
+ *
+ * Author of XPRAM specific coding: Reinhard Buendgen
+ *                                  buendgen@de.ibm.com
+ * Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *
+ * External interfaces:
+ *   Interfaces to linux kernel
+ *        xpram_setup: read kernel parameters
+ *   Device specific file operations
+ *        xpram_iotcl
+ *        xpram_open
+ *
+ * "ad-hoc" partitioning:
+ *    the expanded memory can be partitioned among several devices 
+ *    (with different minors). The partitioning set up can be
+ *    set by kernel or module parameters (int devs & int sizes[])
+ *
+ * Potential future improvements:
+ *   generic hard disk support to replace ad-hoc partitioning
+ */
+
+#define KMSG_COMPONENT "xpram"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ctype.h>  /* isdigit, isxdigit */
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/hdreg.h>  /* HDIO_GETGEO */
+#include <linux/device.h>
+#include <linux/bio.h>
+#include <linux/suspend.h>
+#include <linux/platform_device.h>
+#include <linux/gfp.h>
+#include <linux/uaccess.h>
+
+#define XPRAM_NAME	"xpram"
+#define XPRAM_DEVS	1	/* one partition */
+#define XPRAM_MAX_DEVS	32	/* maximal number of devices (partitions) */
+
+typedef struct {
+	unsigned int	size;		/* size of xpram segment in pages */
+	unsigned int	offset;		/* start page of xpram segment */
+} xpram_device_t;
+
+static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
+static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
+static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
+static struct request_queue *xpram_queues[XPRAM_MAX_DEVS];
+static unsigned int xpram_pages;
+static int xpram_devs;
+
+/*
+ * Parameter parsing functions.
+ */
+static int devs = XPRAM_DEVS;
+static char *sizes[XPRAM_MAX_DEVS];
+
+module_param(devs, int, 0);
+module_param_array(sizes, charp, NULL, 0);
+
+MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
+		 "the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
+MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
+		 "the defaults are 0s \n" \
+		 "All devices with size 0 equally partition the "
+		 "remaining space on the expanded strorage not "
+		 "claimed by explicit sizes\n");
+MODULE_LICENSE("GPL");
+
+/*
+ * Copy expanded memory page (4kB) into main memory                  
+ * Arguments                                                         
+ *           page_addr:    address of target page                    
+ *           xpage_index:  index of expandeded memory page           
+ * Return value                                                      
+ *           0:            if operation succeeds
+ *           -EIO:         if pgin failed
+ *           -ENXIO:       if xpram has vanished
+ */
+static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
+{
+	int cc = 2;	/* return unused cc 2 if pgin traps */
+
+	asm volatile(
+		"	.insn	rre,0xb22e0000,%1,%2\n"  /* pgin %1,%2 */
+		"0:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
+	if (cc == 3)
+		return -ENXIO;
+	if (cc == 2)
+		return -ENXIO;
+	if (cc == 1)
+		return -EIO;
+	return 0;
+}
+
+/*
+ * Copy a 4kB page of main memory to an expanded memory page          
+ * Arguments                                                          
+ *           page_addr:    address of source page                     
+ *           xpage_index:  index of expandeded memory page            
+ * Return value                                                       
+ *           0:            if operation succeeds
+ *           -EIO:         if pgout failed
+ *           -ENXIO:       if xpram has vanished
+ */
+static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
+{
+	int cc = 2;	/* return unused cc 2 if pgin traps */
+
+	asm volatile(
+		"	.insn	rre,0xb22f0000,%1,%2\n"  /* pgout %1,%2 */
+		"0:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
+	if (cc == 3)
+		return -ENXIO;
+	if (cc == 2)
+		return -ENXIO;
+	if (cc == 1)
+		return -EIO;
+	return 0;
+}
+
+/*
+ * Check if xpram is available.
+ */
+static int xpram_present(void)
+{
+	unsigned long mem_page;
+	int rc;
+
+	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
+	if (!mem_page)
+		return -ENOMEM;
+	rc = xpram_page_in(mem_page, 0);
+	free_page(mem_page);
+	return rc ? -ENXIO : 0;
+}
+
+/*
+ * Return index of the last available xpram page.
+ */
+static unsigned long xpram_highest_page_index(void)
+{
+	unsigned int page_index, add_bit;
+	unsigned long mem_page;
+
+	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
+	if (!mem_page)
+		return 0;
+
+	page_index = 0;
+	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
+	while (add_bit > 0) {
+		if (xpram_page_in(mem_page, page_index | add_bit) == 0)
+			page_index |= add_bit;
+		add_bit >>= 1;
+	}
+
+	free_page (mem_page);
+
+	return page_index;
+}
+
+/*
+ * Block device make request function.
+ */
+static blk_qc_t xpram_make_request(struct request_queue *q, struct bio *bio)
+{
+	xpram_device_t *xdev = bio->bi_disk->private_data;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	unsigned int index;
+	unsigned long page_addr;
+	unsigned long bytes;
+
+	blk_queue_split(q, &bio);
+
+	if ((bio->bi_iter.bi_sector & 7) != 0 ||
+	    (bio->bi_iter.bi_size & 4095) != 0)
+		/* Request is not page-aligned. */
+		goto fail;
+	if ((bio->bi_iter.bi_size >> 12) > xdev->size)
+		/* Request size is no page-aligned. */
+		goto fail;
+	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
+		goto fail;
+	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
+	bio_for_each_segment(bvec, bio, iter) {
+		page_addr = (unsigned long)
+			kmap(bvec.bv_page) + bvec.bv_offset;
+		bytes = bvec.bv_len;
+		if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
+			/* More paranoia. */
+			goto fail;
+		while (bytes > 0) {
+			if (bio_data_dir(bio) == READ) {
+				if (xpram_page_in(page_addr, index) != 0)
+					goto fail;
+			} else {
+				if (xpram_page_out(page_addr, index) != 0)
+					goto fail;
+			}
+			page_addr += 4096;
+			bytes -= 4096;
+			index++;
+		}
+	}
+	bio_endio(bio);
+	return BLK_QC_T_NONE;
+fail:
+	bio_io_error(bio);
+	return BLK_QC_T_NONE;
+}
+
+static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	unsigned long size;
+
+	/*
+	 * get geometry: we have to fake one...  trim the size to a
+	 * multiple of 64 (32k): tell we have 16 sectors, 4 heads,
+	 * whatever cylinders. Tell also that data starts at sector. 4.
+	 */
+	size = (xpram_pages * 8) & ~0x3f;
+	geo->cylinders = size >> 6;
+	geo->heads = 4;
+	geo->sectors = 16;
+	geo->start = 4;
+	return 0;
+}
+
+static const struct block_device_operations xpram_devops =
+{
+	.owner	= THIS_MODULE,
+	.getgeo	= xpram_getgeo,
+};
+
+/*
+ * Setup xpram_sizes array.
+ */
+static int __init xpram_setup_sizes(unsigned long pages)
+{
+	unsigned long mem_needed;
+	unsigned long mem_auto;
+	unsigned long long size;
+	char *sizes_end;
+	int mem_auto_no;
+	int i;
+
+	/* Check number of devices. */
+	if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
+		pr_err("%d is not a valid number of XPRAM devices\n",devs);
+		return -EINVAL;
+	}
+	xpram_devs = devs;
+
+	/*
+	 * Copy sizes array to xpram_sizes and align partition
+	 * sizes to page boundary.
+	 */
+	mem_needed = 0;
+	mem_auto_no = 0;
+	for (i = 0; i < xpram_devs; i++) {
+		if (sizes[i]) {
+			size = simple_strtoull(sizes[i], &sizes_end, 0);
+			switch (*sizes_end) {
+			case 'g':
+			case 'G':
+				size <<= 20;
+				break;
+			case 'm':
+			case 'M':
+				size <<= 10;
+			}
+			xpram_sizes[i] = (size + 3) & -4UL;
+		}
+		if (xpram_sizes[i])
+			mem_needed += xpram_sizes[i];
+		else
+			mem_auto_no++;
+	}
+	
+	pr_info("  number of devices (partitions): %d \n", xpram_devs);
+	for (i = 0; i < xpram_devs; i++) {
+		if (xpram_sizes[i])
+			pr_info("  size of partition %d: %u kB\n",
+				i, xpram_sizes[i]);
+		else
+			pr_info("  size of partition %d to be set "
+				"automatically\n",i);
+	}
+	pr_info("  memory needed (for sized partitions): %lu kB\n",
+		mem_needed);
+	pr_info("  partitions to be sized automatically: %d\n",
+		mem_auto_no);
+
+	if (mem_needed > pages * 4) {
+		pr_err("Not enough expanded memory available\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * partitioning:
+	 * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
+	 * else:             ; all partitions with zero xpram_sizes[i]
+	 *                     partition equally the remaining space
+	 */
+	if (mem_auto_no) {
+		mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
+		pr_info("  automatically determined "
+			"partition size: %lu kB\n", mem_auto);
+		for (i = 0; i < xpram_devs; i++)
+			if (xpram_sizes[i] == 0)
+				xpram_sizes[i] = mem_auto;
+	}
+	return 0;
+}
+
+static int __init xpram_setup_blkdev(void)
+{
+	unsigned long offset;
+	int i, rc = -ENOMEM;
+
+	for (i = 0; i < xpram_devs; i++) {
+		xpram_disks[i] = alloc_disk(1);
+		if (!xpram_disks[i])
+			goto out;
+		xpram_queues[i] = blk_alloc_queue(GFP_KERNEL);
+		if (!xpram_queues[i]) {
+			put_disk(xpram_disks[i]);
+			goto out;
+		}
+		blk_queue_flag_set(QUEUE_FLAG_NONROT, xpram_queues[i]);
+		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, xpram_queues[i]);
+		blk_queue_make_request(xpram_queues[i], xpram_make_request);
+		blk_queue_logical_block_size(xpram_queues[i], 4096);
+	}
+
+	/*
+	 * Register xpram major.
+	 */
+	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+	if (rc < 0)
+		goto out;
+
+	/*
+	 * Setup device structures.
+	 */
+	offset = 0;
+	for (i = 0; i < xpram_devs; i++) {
+		struct gendisk *disk = xpram_disks[i];
+
+		xpram_devices[i].size = xpram_sizes[i] / 4;
+		xpram_devices[i].offset = offset;
+		offset += xpram_devices[i].size;
+		disk->major = XPRAM_MAJOR;
+		disk->first_minor = i;
+		disk->fops = &xpram_devops;
+		disk->private_data = &xpram_devices[i];
+		disk->queue = xpram_queues[i];
+		sprintf(disk->disk_name, "slram%d", i);
+		set_capacity(disk, xpram_sizes[i] << 1);
+		add_disk(disk);
+	}
+
+	return 0;
+out:
+	while (i--) {
+		blk_cleanup_queue(xpram_queues[i]);
+		put_disk(xpram_disks[i]);
+	}
+	return rc;
+}
+
+/*
+ * Resume failed: Print error message and call panic.
+ */
+static void xpram_resume_error(const char *message)
+{
+	pr_err("Resuming the system failed: %s\n", message);
+	panic("xpram resume error\n");
+}
+
+/*
+ * Check if xpram setup changed between suspend and resume.
+ */
+static int xpram_restore(struct device *dev)
+{
+	if (!xpram_pages)
+		return 0;
+	if (xpram_present() != 0)
+		xpram_resume_error("xpram disappeared");
+	if (xpram_pages != xpram_highest_page_index() + 1)
+		xpram_resume_error("Size of xpram changed");
+	return 0;
+}
+
+static const struct dev_pm_ops xpram_pm_ops = {
+	.restore	= xpram_restore,
+};
+
+static struct platform_driver xpram_pdrv = {
+	.driver = {
+		.name	= XPRAM_NAME,
+		.pm	= &xpram_pm_ops,
+	},
+};
+
+static struct platform_device *xpram_pdev;
+
+/*
+ * Finally, the init/exit functions.
+ */
+static void __exit xpram_exit(void)
+{
+	int i;
+	for (i = 0; i < xpram_devs; i++) {
+		del_gendisk(xpram_disks[i]);
+		blk_cleanup_queue(xpram_queues[i]);
+		put_disk(xpram_disks[i]);
+	}
+	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+	platform_device_unregister(xpram_pdev);
+	platform_driver_unregister(&xpram_pdrv);
+}
+
+static int __init xpram_init(void)
+{
+	int rc;
+
+	/* Find out size of expanded memory. */
+	if (xpram_present() != 0) {
+		pr_err("No expanded memory available\n");
+		return -ENODEV;
+	}
+	xpram_pages = xpram_highest_page_index() + 1;
+	pr_info("  %u pages expanded memory found (%lu KB).\n",
+		xpram_pages, (unsigned long) xpram_pages*4);
+	rc = xpram_setup_sizes(xpram_pages);
+	if (rc)
+		return rc;
+	rc = platform_driver_register(&xpram_pdrv);
+	if (rc)
+		return rc;
+	xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
+	if (IS_ERR(xpram_pdev)) {
+		rc = PTR_ERR(xpram_pdev);
+		goto fail_platform_driver_unregister;
+	}
+	rc = xpram_setup_blkdev();
+	if (rc)
+		goto fail_platform_device_unregister;
+	return 0;
+
+fail_platform_device_unregister:
+	platform_device_unregister(xpram_pdev);
+fail_platform_driver_unregister:
+	platform_driver_unregister(&xpram_pdrv);
+	return rc;
+}
+
+module_init(xpram_init);
+module_exit(xpram_exit);