Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 652 insertions, 0 deletions

diff --git a/drivers/s390/char/monreader.c b/drivers/s390/char/monreader.c
new file mode 100644
index 000000000..7bc616b25
--- /dev/null
+++ b/drivers/s390/char/monreader.c
@@ -0,0 +1,652 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Character device driver for reading z/VM *MONITOR service records.
+ *
+ * Copyright IBM Corp. 2004, 2009
+ *
+ * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "monreader"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/ctype.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <net/iucv/iucv.h>
+#include <linux/uaccess.h>
+#include <asm/ebcdic.h>
+#include <asm/extmem.h>
+
+
+#define MON_COLLECT_SAMPLE 0x80
+#define MON_COLLECT_EVENT  0x40
+#define MON_SERVICE	   "*MONITOR"
+#define MON_IN_USE	   0x01
+#define MON_MSGLIM	   255
+
+static char mon_dcss_name[9] = "MONDCSS\0";
+
+struct mon_msg {
+	u32 pos;
+	u32 mca_offset;
+	struct iucv_message msg;
+	char msglim_reached;
+	char replied_msglim;
+};
+
+struct mon_private {
+	struct iucv_path *path;
+	struct mon_msg *msg_array[MON_MSGLIM];
+	unsigned int   write_index;
+	unsigned int   read_index;
+	atomic_t msglim_count;
+	atomic_t read_ready;
+	atomic_t iucv_connected;
+	atomic_t iucv_severed;
+};
+
+static unsigned long mon_in_use = 0;
+
+static unsigned long mon_dcss_start;
+static unsigned long mon_dcss_end;
+
+static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue);
+static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue);
+
+static u8 user_data_connect[16] = {
+	/* Version code, must be 0x01 for shared mode */
+	0x01,
+	/* what to collect */
+	MON_COLLECT_SAMPLE | MON_COLLECT_EVENT,
+	/* DCSS name in EBCDIC, 8 bytes padded with blanks */
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+};
+
+static u8 user_data_sever[16] = {
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+};
+
+static struct device *monreader_device;
+
+/******************************************************************************
+ *                             helper functions                               *
+ *****************************************************************************/
+/*
+ * Create the 8 bytes EBCDIC DCSS segment name from
+ * an ASCII name, incl. padding
+ */
+static void dcss_mkname(char *ascii_name, char *ebcdic_name)
+{
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		if (ascii_name[i] == '\0')
+			break;
+		ebcdic_name[i] = toupper(ascii_name[i]);
+	}
+	for (; i < 8; i++)
+		ebcdic_name[i] = ' ';
+	ASCEBC(ebcdic_name, 8);
+}
+
+static inline unsigned long mon_mca_start(struct mon_msg *monmsg)
+{
+	return *(u32 *) &monmsg->msg.rmmsg;
+}
+
+static inline unsigned long mon_mca_end(struct mon_msg *monmsg)
+{
+	return *(u32 *) &monmsg->msg.rmmsg[4];
+}
+
+static inline u8 mon_mca_type(struct mon_msg *monmsg, u8 index)
+{
+	return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index);
+}
+
+static inline u32 mon_mca_size(struct mon_msg *monmsg)
+{
+	return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1;
+}
+
+static inline u32 mon_rec_start(struct mon_msg *monmsg)
+{
+	return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4));
+}
+
+static inline u32 mon_rec_end(struct mon_msg *monmsg)
+{
+	return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8));
+}
+
+static int mon_check_mca(struct mon_msg *monmsg)
+{
+	if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) ||
+	    (mon_rec_start(monmsg) < mon_dcss_start) ||
+	    (mon_rec_end(monmsg) > mon_dcss_end) ||
+	    (mon_mca_type(monmsg, 0) == 0) ||
+	    (mon_mca_size(monmsg) % 12 != 0) ||
+	    (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) ||
+	    (mon_mca_end(monmsg) > mon_dcss_end) ||
+	    (mon_mca_start(monmsg) < mon_dcss_start) ||
+	    ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0)))
+		return -EINVAL;
+	return 0;
+}
+
+static int mon_send_reply(struct mon_msg *monmsg,
+			  struct mon_private *monpriv)
+{
+	int rc;
+
+	rc = iucv_message_reply(monpriv->path, &monmsg->msg,
+				IUCV_IPRMDATA, NULL, 0);
+	atomic_dec(&monpriv->msglim_count);
+	if (likely(!monmsg->msglim_reached)) {
+		monmsg->pos = 0;
+		monmsg->mca_offset = 0;
+		monpriv->read_index = (monpriv->read_index + 1) %
+				      MON_MSGLIM;
+		atomic_dec(&monpriv->read_ready);
+	} else
+		monmsg->replied_msglim = 1;
+	if (rc) {
+		pr_err("Reading monitor data failed with rc=%i\n", rc);
+		return -EIO;
+	}
+	return 0;
+}
+
+static void mon_free_mem(struct mon_private *monpriv)
+{
+	int i;
+
+	for (i = 0; i < MON_MSGLIM; i++)
+		kfree(monpriv->msg_array[i]);
+	kfree(monpriv);
+}
+
+static struct mon_private *mon_alloc_mem(void)
+{
+	int i;
+	struct mon_private *monpriv;
+
+	monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
+	if (!monpriv)
+		return NULL;
+	for (i = 0; i < MON_MSGLIM; i++) {
+		monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg),
+						    GFP_KERNEL);
+		if (!monpriv->msg_array[i]) {
+			mon_free_mem(monpriv);
+			return NULL;
+		}
+	}
+	return monpriv;
+}
+
+static inline void mon_next_mca(struct mon_msg *monmsg)
+{
+	if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
+		return;
+	monmsg->mca_offset += 12;
+	monmsg->pos = 0;
+}
+
+static struct mon_msg *mon_next_message(struct mon_private *monpriv)
+{
+	struct mon_msg *monmsg;
+
+	if (!atomic_read(&monpriv->read_ready))
+		return NULL;
+	monmsg = monpriv->msg_array[monpriv->read_index];
+	if (unlikely(monmsg->replied_msglim)) {
+		monmsg->replied_msglim = 0;
+		monmsg->msglim_reached = 0;
+		monmsg->pos = 0;
+		monmsg->mca_offset = 0;
+		monpriv->read_index = (monpriv->read_index + 1) %
+				      MON_MSGLIM;
+		atomic_dec(&monpriv->read_ready);
+		return ERR_PTR(-EOVERFLOW);
+	}
+	return monmsg;
+}
+
+
+/******************************************************************************
+ *                               IUCV handler                                 *
+ *****************************************************************************/
+static void mon_iucv_path_complete(struct iucv_path *path, u8 *ipuser)
+{
+	struct mon_private *monpriv = path->private;
+
+	atomic_set(&monpriv->iucv_connected, 1);
+	wake_up(&mon_conn_wait_queue);
+}
+
+static void mon_iucv_path_severed(struct iucv_path *path, u8 *ipuser)
+{
+	struct mon_private *monpriv = path->private;
+
+	pr_err("z/VM *MONITOR system service disconnected with rc=%i\n",
+	       ipuser[0]);
+	iucv_path_sever(path, NULL);
+	atomic_set(&monpriv->iucv_severed, 1);
+	wake_up(&mon_conn_wait_queue);
+	wake_up_interruptible(&mon_read_wait_queue);
+}
+
+static void mon_iucv_message_pending(struct iucv_path *path,
+				     struct iucv_message *msg)
+{
+	struct mon_private *monpriv = path->private;
+
+	memcpy(&monpriv->msg_array[monpriv->write_index]->msg,
+	       msg, sizeof(*msg));
+	if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
+		pr_warn("The read queue for monitor data is full\n");
+		monpriv->msg_array[monpriv->write_index]->msglim_reached = 1;
+	}
+	monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM;
+	atomic_inc(&monpriv->read_ready);
+	wake_up_interruptible(&mon_read_wait_queue);
+}
+
+static struct iucv_handler monreader_iucv_handler = {
+	.path_complete	 = mon_iucv_path_complete,
+	.path_severed	 = mon_iucv_path_severed,
+	.message_pending = mon_iucv_message_pending,
+};
+
+/******************************************************************************
+ *                               file operations                              *
+ *****************************************************************************/
+static int mon_open(struct inode *inode, struct file *filp)
+{
+	struct mon_private *monpriv;
+	int rc;
+
+	/*
+	 * only one user allowed
+	 */
+	rc = -EBUSY;
+	if (test_and_set_bit(MON_IN_USE, &mon_in_use))
+		goto out;
+
+	rc = -ENOMEM;
+	monpriv = mon_alloc_mem();
+	if (!monpriv)
+		goto out_use;
+
+	/*
+	 * Connect to *MONITOR service
+	 */
+	monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
+	if (!monpriv->path)
+		goto out_priv;
+	rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
+			       MON_SERVICE, NULL, user_data_connect, monpriv);
+	if (rc) {
+		pr_err("Connecting to the z/VM *MONITOR system service "
+		       "failed with rc=%i\n", rc);
+		rc = -EIO;
+		goto out_path;
+	}
+	/*
+	 * Wait for connection confirmation
+	 */
+	wait_event(mon_conn_wait_queue,
+		   atomic_read(&monpriv->iucv_connected) ||
+		   atomic_read(&monpriv->iucv_severed));
+	if (atomic_read(&monpriv->iucv_severed)) {
+		atomic_set(&monpriv->iucv_severed, 0);
+		atomic_set(&monpriv->iucv_connected, 0);
+		rc = -EIO;
+		goto out_path;
+	}
+	filp->private_data = monpriv;
+	dev_set_drvdata(monreader_device, monpriv);
+	return nonseekable_open(inode, filp);
+
+out_path:
+	iucv_path_free(monpriv->path);
+out_priv:
+	mon_free_mem(monpriv);
+out_use:
+	clear_bit(MON_IN_USE, &mon_in_use);
+out:
+	return rc;
+}
+
+static int mon_close(struct inode *inode, struct file *filp)
+{
+	int rc, i;
+	struct mon_private *monpriv = filp->private_data;
+
+	/*
+	 * Close IUCV connection and unregister
+	 */
+	if (monpriv->path) {
+		rc = iucv_path_sever(monpriv->path, user_data_sever);
+		if (rc)
+			pr_warn("Disconnecting the z/VM *MONITOR system service failed with rc=%i\n",
+				rc);
+		iucv_path_free(monpriv->path);
+	}
+
+	atomic_set(&monpriv->iucv_severed, 0);
+	atomic_set(&monpriv->iucv_connected, 0);
+	atomic_set(&monpriv->read_ready, 0);
+	atomic_set(&monpriv->msglim_count, 0);
+	monpriv->write_index  = 0;
+	monpriv->read_index   = 0;
+	dev_set_drvdata(monreader_device, NULL);
+
+	for (i = 0; i < MON_MSGLIM; i++)
+		kfree(monpriv->msg_array[i]);
+	kfree(monpriv);
+	clear_bit(MON_IN_USE, &mon_in_use);
+	return 0;
+}
+
+static ssize_t mon_read(struct file *filp, char __user *data,
+			size_t count, loff_t *ppos)
+{
+	struct mon_private *monpriv = filp->private_data;
+	struct mon_msg *monmsg;
+	int ret;
+	u32 mce_start;
+
+	monmsg = mon_next_message(monpriv);
+	if (IS_ERR(monmsg))
+		return PTR_ERR(monmsg);
+
+	if (!monmsg) {
+		if (filp->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+		ret = wait_event_interruptible(mon_read_wait_queue,
+					atomic_read(&monpriv->read_ready) ||
+					atomic_read(&monpriv->iucv_severed));
+		if (ret)
+			return ret;
+		if (unlikely(atomic_read(&monpriv->iucv_severed)))
+			return -EIO;
+		monmsg = monpriv->msg_array[monpriv->read_index];
+	}
+
+	if (!monmsg->pos)
+		monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset;
+	if (mon_check_mca(monmsg))
+		goto reply;
+
+	/* read monitor control element (12 bytes) first */
+	mce_start = mon_mca_start(monmsg) + monmsg->mca_offset;
+	if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) {
+		count = min(count, (size_t) mce_start + 12 - monmsg->pos);
+		ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
+				   count);
+		if (ret)
+			return -EFAULT;
+		monmsg->pos += count;
+		if (monmsg->pos == mce_start + 12)
+			monmsg->pos = mon_rec_start(monmsg);
+		goto out_copy;
+	}
+
+	/* read records */
+	if (monmsg->pos <= mon_rec_end(monmsg)) {
+		count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos
+					    + 1);
+		ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
+				   count);
+		if (ret)
+			return -EFAULT;
+		monmsg->pos += count;
+		if (monmsg->pos > mon_rec_end(monmsg))
+			mon_next_mca(monmsg);
+		goto out_copy;
+	}
+reply:
+	ret = mon_send_reply(monmsg, monpriv);
+	return ret;
+
+out_copy:
+	*ppos += count;
+	return count;
+}
+
+static __poll_t mon_poll(struct file *filp, struct poll_table_struct *p)
+{
+	struct mon_private *monpriv = filp->private_data;
+
+	poll_wait(filp, &mon_read_wait_queue, p);
+	if (unlikely(atomic_read(&monpriv->iucv_severed)))
+		return EPOLLERR;
+	if (atomic_read(&monpriv->read_ready))
+		return EPOLLIN | EPOLLRDNORM;
+	return 0;
+}
+
+static const struct file_operations mon_fops = {
+	.owner   = THIS_MODULE,
+	.open    = &mon_open,
+	.release = &mon_close,
+	.read    = &mon_read,
+	.poll    = &mon_poll,
+	.llseek  = noop_llseek,
+};
+
+static struct miscdevice mon_dev = {
+	.name       = "monreader",
+	.fops       = &mon_fops,
+	.minor      = MISC_DYNAMIC_MINOR,
+};
+
+
+/******************************************************************************
+ *				suspend / resume			      *
+ *****************************************************************************/
+static int monreader_freeze(struct device *dev)
+{
+	struct mon_private *monpriv = dev_get_drvdata(dev);
+	int rc;
+
+	if (!monpriv)
+		return 0;
+	if (monpriv->path) {
+		rc = iucv_path_sever(monpriv->path, user_data_sever);
+		if (rc)
+			pr_warn("Disconnecting the z/VM *MONITOR system service failed with rc=%i\n",
+				rc);
+		iucv_path_free(monpriv->path);
+	}
+	atomic_set(&monpriv->iucv_severed, 0);
+	atomic_set(&monpriv->iucv_connected, 0);
+	atomic_set(&monpriv->read_ready, 0);
+	atomic_set(&monpriv->msglim_count, 0);
+	monpriv->write_index  = 0;
+	monpriv->read_index   = 0;
+	monpriv->path = NULL;
+	return 0;
+}
+
+static int monreader_thaw(struct device *dev)
+{
+	struct mon_private *monpriv = dev_get_drvdata(dev);
+	int rc;
+
+	if (!monpriv)
+		return 0;
+	rc = -ENOMEM;
+	monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
+	if (!monpriv->path)
+		goto out;
+	rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
+			       MON_SERVICE, NULL, user_data_connect, monpriv);
+	if (rc) {
+		pr_err("Connecting to the z/VM *MONITOR system service "
+		       "failed with rc=%i\n", rc);
+		goto out_path;
+	}
+	wait_event(mon_conn_wait_queue,
+		   atomic_read(&monpriv->iucv_connected) ||
+		   atomic_read(&monpriv->iucv_severed));
+	if (atomic_read(&monpriv->iucv_severed))
+		goto out_path;
+	return 0;
+out_path:
+	rc = -EIO;
+	iucv_path_free(monpriv->path);
+	monpriv->path = NULL;
+out:
+	atomic_set(&monpriv->iucv_severed, 1);
+	return rc;
+}
+
+static int monreader_restore(struct device *dev)
+{
+	int rc;
+
+	segment_unload(mon_dcss_name);
+	rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
+			  &mon_dcss_start, &mon_dcss_end);
+	if (rc < 0) {
+		segment_warning(rc, mon_dcss_name);
+		panic("fatal monreader resume error: no monitor dcss\n");
+	}
+	return monreader_thaw(dev);
+}
+
+static const struct dev_pm_ops monreader_pm_ops = {
+	.freeze  = monreader_freeze,
+	.thaw	 = monreader_thaw,
+	.restore = monreader_restore,
+};
+
+static struct device_driver monreader_driver = {
+	.name = "monreader",
+	.bus  = &iucv_bus,
+	.pm   = &monreader_pm_ops,
+};
+
+
+/******************************************************************************
+ *                              module init/exit                              *
+ *****************************************************************************/
+static int __init mon_init(void)
+{
+	int rc;
+
+	if (!MACHINE_IS_VM) {
+		pr_err("The z/VM *MONITOR record device driver cannot be "
+		       "loaded without z/VM\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Register with IUCV and connect to *MONITOR service
+	 */
+	rc = iucv_register(&monreader_iucv_handler, 1);
+	if (rc) {
+		pr_err("The z/VM *MONITOR record device driver failed to "
+		       "register with IUCV\n");
+		return rc;
+	}
+
+	rc = driver_register(&monreader_driver);
+	if (rc)
+		goto out_iucv;
+	monreader_device = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!monreader_device) {
+		rc = -ENOMEM;
+		goto out_driver;
+	}
+
+	dev_set_name(monreader_device, "monreader-dev");
+	monreader_device->bus = &iucv_bus;
+	monreader_device->parent = iucv_root;
+	monreader_device->driver = &monreader_driver;
+	monreader_device->release = (void (*)(struct device *))kfree;
+	rc = device_register(monreader_device);
+	if (rc) {
+		put_device(monreader_device);
+		goto out_driver;
+	}
+
+	rc = segment_type(mon_dcss_name);
+	if (rc < 0) {
+		segment_warning(rc, mon_dcss_name);
+		goto out_device;
+	}
+	if (rc != SEG_TYPE_SC) {
+		pr_err("The specified *MONITOR DCSS %s does not have the "
+		       "required type SC\n", mon_dcss_name);
+		rc = -EINVAL;
+		goto out_device;
+	}
+
+	rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
+			  &mon_dcss_start, &mon_dcss_end);
+	if (rc < 0) {
+		segment_warning(rc, mon_dcss_name);
+		rc = -EINVAL;
+		goto out_device;
+	}
+	dcss_mkname(mon_dcss_name, &user_data_connect[8]);
+
+	/*
+	 * misc_register() has to be the last action in module_init(), because
+	 * file operations will be available right after this.
+	 */
+	rc = misc_register(&mon_dev);
+	if (rc < 0 )
+		goto out;
+	return 0;
+
+out:
+	segment_unload(mon_dcss_name);
+out_device:
+	device_unregister(monreader_device);
+out_driver:
+	driver_unregister(&monreader_driver);
+out_iucv:
+	iucv_unregister(&monreader_iucv_handler, 1);
+	return rc;
+}
+
+static void __exit mon_exit(void)
+{
+	segment_unload(mon_dcss_name);
+	misc_deregister(&mon_dev);
+	device_unregister(monreader_device);
+	driver_unregister(&monreader_driver);
+	iucv_unregister(&monreader_iucv_handler, 1);
+	return;
+}
+
+
+module_init(mon_init);
+module_exit(mon_exit);
+
+module_param_string(mondcss, mon_dcss_name, 9, 0444);
+MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR "
+		 "service, max. 8 chars. Default is MONDCSS");
+
+MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>");
+MODULE_DESCRIPTION("Character device driver for reading z/VM "
+		   "monitor service records.");
+MODULE_LICENSE("GPL");