Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 1747 insertions, 0 deletions

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();
+}