[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / s390 / char / monreader.c

/*
 * 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 <asm/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[16])
{
	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[16])
{
	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_warning("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_warning("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 unsigned int 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 POLLERR;
	if (atomic_read(&monpriv->read_ready))
		return POLLIN | POLLRDNORM;
	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_warning("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");
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* Character device driver for reading z/VM *MONITOR service records.
1da177e4 LT	3	*
2b1e3e55 GS	4	* Copyright IBM Corp. 2004, 2009
	5	*
	6	* Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
1da177e4 LT	7	*/
1da177e4 LT	8
a4f5a299 GS	9	#define KMSG_COMPONENT "monreader"
	10	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	11
1da177e4 LT	12	#include <linux/module.h>
	13	#include <linux/moduleparam.h>
	14	#include <linux/init.h>
	15	#include <linux/errno.h>
	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
	18	#include <linux/miscdevice.h>
	19	#include <linux/ctype.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/interrupt.h>
2ca5b6e2	22	#include <linux/poll.h>
2b1e3e55	23	#include <linux/device.h>
5a0e3ad6	24	#include <linux/slab.h>
2ca5b6e2	25	#include <net/iucv/iucv.h>
1da177e4 LT	26	#include <asm/uaccess.h>
	27	#include <asm/ebcdic.h>
	28	#include <asm/extmem.h>
1da177e4	29
1da177e4 LT	30
	31	#define MON_COLLECT_SAMPLE 0x80
	32	#define MON_COLLECT_EVENT 0x40
	33	#define MON_SERVICE "*MONITOR"
	34	#define MON_IN_USE 0x01
	35	#define MON_MSGLIM 255
	36
	37	static char mon_dcss_name[9] = "MONDCSS\0";
	38
	39	struct mon_msg {
	40	u32 pos;
	41	u32 mca_offset;
c667aac8	42	struct iucv_message msg;
1da177e4 LT	43	char msglim_reached;
	44	char replied_msglim;
	45	};
	46
	47	struct mon_private {
c667aac8	48	struct iucv_path *path;
1da177e4 LT	49	struct mon_msg *msg_array[MON_MSGLIM];
	50	unsigned int write_index;
	51	unsigned int read_index;
	52	atomic_t msglim_count;
	53	atomic_t read_ready;
	54	atomic_t iucv_connected;
	55	atomic_t iucv_severed;
	56	};
	57
	58	static unsigned long mon_in_use = 0;
	59
	60	static unsigned long mon_dcss_start;
	61	static unsigned long mon_dcss_end;
	62
	63	static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue);
	64	static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue);
	65
1da177e4 LT	66	static u8 user_data_connect[16] = {
	67	/* Version code, must be 0x01 for shared mode */
	68	0x01,
	69	/* what to collect */
	70	MON_COLLECT_SAMPLE \| MON_COLLECT_EVENT,
	71	/* DCSS name in EBCDIC, 8 bytes padded with blanks */
	72	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	73	0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	74	};
	75
	76	static u8 user_data_sever[16] = {
	77	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	78	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	79	};
	80
2b1e3e55	81	static struct device *monreader_device;
1da177e4 LT	82
	83	/******************************************************************************
	84	* helper functions *
	85	*****************************************************************************/
	86	/*
	87	* Create the 8 bytes EBCDIC DCSS segment name from
	88	* an ASCII name, incl. padding
	89	*/
9b0c455a	90	static void dcss_mkname(char ascii_name, char ebcdic_name)
1da177e4 LT	91	{
	92	int i;
	93
	94	for (i = 0; i < 8; i++) {
	95	if (ascii_name[i] == '\0')
	96	break;
	97	ebcdic_name[i] = toupper(ascii_name[i]);
	98	};
	99	for (; i < 8; i++)
	100	ebcdic_name[i] = ' ';
	101	ASCEBC(ebcdic_name, 8);
	102	}
	103
c667aac8	104	static inline unsigned long mon_mca_start(struct mon_msg *monmsg)
1da177e4	105	{
c667aac8	106	return (u32 ) &monmsg->msg.rmmsg;
1da177e4 LT	107	}
1da177e4 LT	108
c667aac8	109	static inline unsigned long mon_mca_end(struct mon_msg *monmsg)
1da177e4	110	{
c667aac8	111	return (u32 ) &monmsg->msg.rmmsg[4];
1da177e4 LT	112	}
1da177e4 LT	113
c667aac8	114	static inline u8 mon_mca_type(struct mon_msg *monmsg, u8 index)
1da177e4 LT	115	{
	116	return ((u8 ) mon_mca_start(monmsg) + monmsg->mca_offset + index);
	117	}
	118
c667aac8	119	static inline u32 mon_mca_size(struct mon_msg *monmsg)
1da177e4 LT	120	{
	121	return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1;
	122	}
	123
c667aac8	124	static inline u32 mon_rec_start(struct mon_msg *monmsg)
1da177e4 LT	125	{
	126	return ((u32 ) (mon_mca_start(monmsg) + monmsg->mca_offset + 4));
	127	}
	128
c667aac8	129	static inline u32 mon_rec_end(struct mon_msg *monmsg)
1da177e4 LT	130	{
	131	return ((u32 ) (mon_mca_start(monmsg) + monmsg->mca_offset + 8));
	132	}
	133
9b0c455a	134	static int mon_check_mca(struct mon_msg *monmsg)
1da177e4 LT	135	{
	136	if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) \|\|
	137	(mon_rec_start(monmsg) < mon_dcss_start) \|\|
	138	(mon_rec_end(monmsg) > mon_dcss_end) \|\|
	139	(mon_mca_type(monmsg, 0) == 0) \|\|
	140	(mon_mca_size(monmsg) % 12 != 0) \|\|
	141	(mon_mca_end(monmsg) <= mon_mca_start(monmsg)) \|\|
	142	(mon_mca_end(monmsg) > mon_dcss_end) \|\|
	143	(mon_mca_start(monmsg) < mon_dcss_start) \|\|
	144	((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0)))
1da177e4	145	return -EINVAL;
1da177e4 LT	146	return 0;
	147	}
	148
9b0c455a MS	149	static int mon_send_reply(struct mon_msg *monmsg,
9b0c455a MS	150	struct mon_private *monpriv)
1da177e4	151	{
1da177e4 LT	152	int rc;
1da177e4 LT	153
c667aac8 MS	154	rc = iucv_message_reply(monpriv->path, &monmsg->msg,
c667aac8 MS	155	IUCV_IPRMDATA, NULL, 0);
1da177e4 LT	156	atomic_dec(&monpriv->msglim_count);
	157	if (likely(!monmsg->msglim_reached)) {
	158	monmsg->pos = 0;
	159	monmsg->mca_offset = 0;
	160	monpriv->read_index = (monpriv->read_index + 1) %
	161	MON_MSGLIM;
	162	atomic_dec(&monpriv->read_ready);
	163	} else
	164	monmsg->replied_msglim = 1;
	165	if (rc) {
a4f5a299	166	pr_err("Reading monitor data failed with rc=%i\n", rc);
1da177e4 LT	167	return -EIO;
	168	}
	169	return 0;
	170	}
	171
9b0c455a	172	static void mon_free_mem(struct mon_private *monpriv)
c667aac8 MS	173	{
	174	int i;
	175
	176	for (i = 0; i < MON_MSGLIM; i++)
a75a282d	177	kfree(monpriv->msg_array[i]);
c667aac8 MS	178	kfree(monpriv);
	179	}
	180
9b0c455a	181	static struct mon_private *mon_alloc_mem(void)
1da177e4	182	{
c667aac8	183	int i;
1da177e4 LT	184	struct mon_private *monpriv;
1da177e4 LT	185
88abaab4	186	monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
2ca5b6e2	187	if (!monpriv)
1da177e4	188	return NULL;
1da177e4	189	for (i = 0; i < MON_MSGLIM; i++) {
88abaab4	190	monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg),
1da177e4 LT	191	GFP_KERNEL);
1da177e4 LT	192	if (!monpriv->msg_array[i]) {
c667aac8	193	mon_free_mem(monpriv);
1da177e4 LT	194	return NULL;
1da177e4 LT	195	}
1da177e4 LT	196	}
	197	return monpriv;
	198	}
	199
c667aac8	200	static inline void mon_next_mca(struct mon_msg *monmsg)
1da177e4 LT	201	{
	202	if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
	203	return;
1da177e4 LT	204	monmsg->mca_offset += 12;
	205	monmsg->pos = 0;
	206	}
	207
9b0c455a	208	static struct mon_msg mon_next_message(struct mon_private monpriv)
1da177e4 LT	209	{
	210	struct mon_msg *monmsg;
	211
	212	if (!atomic_read(&monpriv->read_ready))
	213	return NULL;
	214	monmsg = monpriv->msg_array[monpriv->read_index];
	215	if (unlikely(monmsg->replied_msglim)) {
	216	monmsg->replied_msglim = 0;
	217	monmsg->msglim_reached = 0;
	218	monmsg->pos = 0;
	219	monmsg->mca_offset = 0;
1da177e4 LT	220	monpriv->read_index = (monpriv->read_index + 1) %
	221	MON_MSGLIM;
	222	atomic_dec(&monpriv->read_ready);
	223	return ERR_PTR(-EOVERFLOW);
	224	}
	225	return monmsg;
	226	}
	227
	228
	229	/******************************************************************************
	230	* IUCV handler *
	231	*****************************************************************************/
c667aac8	232	static void mon_iucv_path_complete(struct iucv_path *path, u8 ipuser[16])
1da177e4	233	{
c667aac8	234	struct mon_private *monpriv = path->private;
1da177e4	235
1da177e4 LT	236	atomic_set(&monpriv->iucv_connected, 1);
	237	wake_up(&mon_conn_wait_queue);
	238	}
	239
c667aac8	240	static void mon_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
1da177e4	241	{
c667aac8	242	struct mon_private *monpriv = path->private;
1da177e4	243
a4f5a299 GS	244	pr_err("z/VM *MONITOR system service disconnected with rc=%i\n",
a4f5a299 GS	245	ipuser[0]);
c667aac8	246	iucv_path_sever(path, NULL);
1da177e4 LT	247	atomic_set(&monpriv->iucv_severed, 1);
	248	wake_up(&mon_conn_wait_queue);
	249	wake_up_interruptible(&mon_read_wait_queue);
	250	}
	251
c667aac8 MS	252	static void mon_iucv_message_pending(struct iucv_path *path,
c667aac8 MS	253	struct iucv_message *msg)
1da177e4	254	{
c667aac8	255	struct mon_private *monpriv = path->private;
1da177e4	256
c667aac8 MS	257	memcpy(&monpriv->msg_array[monpriv->write_index]->msg,
c667aac8 MS	258	msg, sizeof(*msg));
1da177e4	259	if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
a4f5a299	260	pr_warning("The read queue for monitor data is full\n");
1da177e4 LT	261	monpriv->msg_array[monpriv->write_index]->msglim_reached = 1;
	262	}
	263	monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM;
	264	atomic_inc(&monpriv->read_ready);
	265	wake_up_interruptible(&mon_read_wait_queue);
	266	}
	267
c667aac8 MS	268	static struct iucv_handler monreader_iucv_handler = {
	269	.path_complete = mon_iucv_path_complete,
	270	.path_severed = mon_iucv_path_severed,
	271	.message_pending = mon_iucv_message_pending,
1da177e4 LT	272	};
	273
	274	/******************************************************************************
	275	* file operations *
	276	*****************************************************************************/
c667aac8	277	static int mon_open(struct inode inode, struct file filp)
1da177e4	278	{
1da177e4	279	struct mon_private *monpriv;
c667aac8	280	int rc;
1da177e4 LT	281
	282	/*
	283	* only one user allowed
	284	*/
c667aac8	285	rc = -EBUSY;
1da177e4	286	if (test_and_set_bit(MON_IN_USE, &mon_in_use))
c667aac8	287	goto out;
1da177e4	288
c667aac8	289	rc = -ENOMEM;
1da177e4 LT	290	monpriv = mon_alloc_mem();
1da177e4 LT	291	if (!monpriv)
c667aac8	292	goto out_use;
1da177e4 LT	293
1da177e4 LT	294	/*
c667aac8	295	* Connect to *MONITOR service
1da177e4	296	*/
c667aac8 MS	297	monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
	298	if (!monpriv->path)
	299	goto out_priv;
	300	rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
	301	MON_SERVICE, NULL, user_data_connect, monpriv);
1da177e4	302	if (rc) {
a4f5a299 GS	303	pr_err("Connecting to the z/VM *MONITOR system service "
a4f5a299 GS	304	"failed with rc=%i\n", rc);
1da177e4	305	rc = -EIO;
c667aac8	306	goto out_path;
1da177e4 LT	307	}
	308	/*
	309	* Wait for connection confirmation
	310	*/
	311	wait_event(mon_conn_wait_queue,
	312	atomic_read(&monpriv->iucv_connected) \|\|
	313	atomic_read(&monpriv->iucv_severed));
	314	if (atomic_read(&monpriv->iucv_severed)) {
	315	atomic_set(&monpriv->iucv_severed, 0);
	316	atomic_set(&monpriv->iucv_connected, 0);
	317	rc = -EIO;
c667aac8	318	goto out_path;
1da177e4	319	}
1da177e4	320	filp->private_data = monpriv;
99357742	321	dev_set_drvdata(monreader_device, monpriv);
1da177e4 LT	322	return nonseekable_open(inode, filp);
1da177e4 LT	323
c667aac8	324	out_path:
2b1e3e55	325	iucv_path_free(monpriv->path);
c667aac8 MS	326	out_priv:
	327	mon_free_mem(monpriv);
	328	out_use:
1da177e4	329	clear_bit(MON_IN_USE, &mon_in_use);
c667aac8	330	out:
1da177e4 LT	331	return rc;
	332	}
	333
c667aac8	334	static int mon_close(struct inode inode, struct file filp)
1da177e4 LT	335	{
	336	int rc, i;
	337	struct mon_private *monpriv = filp->private_data;
	338
	339	/*
	340	* Close IUCV connection and unregister
	341	*/
2b1e3e55 GS	342	if (monpriv->path) {
	343	rc = iucv_path_sever(monpriv->path, user_data_sever);
	344	if (rc)
	345	pr_warning("Disconnecting the z/VM *MONITOR system "
	346	"service failed with rc=%i\n", rc);
	347	iucv_path_free(monpriv->path);
	348	}
1da177e4	349
1da177e4 LT	350	atomic_set(&monpriv->iucv_severed, 0);
	351	atomic_set(&monpriv->iucv_connected, 0);
	352	atomic_set(&monpriv->read_ready, 0);
	353	atomic_set(&monpriv->msglim_count, 0);
	354	monpriv->write_index = 0;
	355	monpriv->read_index = 0;
ccaf6553	356	dev_set_drvdata(monreader_device, NULL);
1da177e4 LT	357
	358	for (i = 0; i < MON_MSGLIM; i++)
	359	kfree(monpriv->msg_array[i]);
	360	kfree(monpriv);
	361	clear_bit(MON_IN_USE, &mon_in_use);
	362	return 0;
	363	}
	364
c667aac8 MS	365	static ssize_t mon_read(struct file filp, char __user data,
c667aac8 MS	366	size_t count, loff_t *ppos)
1da177e4 LT	367	{
	368	struct mon_private *monpriv = filp->private_data;
	369	struct mon_msg *monmsg;
	370	int ret;
	371	u32 mce_start;
	372
	373	monmsg = mon_next_message(monpriv);
	374	if (IS_ERR(monmsg))
	375	return PTR_ERR(monmsg);
	376
	377	if (!monmsg) {
	378	if (filp->f_flags & O_NONBLOCK)
	379	return -EAGAIN;
	380	ret = wait_event_interruptible(mon_read_wait_queue,
	381	atomic_read(&monpriv->read_ready) \|\|
	382	atomic_read(&monpriv->iucv_severed));
	383	if (ret)
	384	return ret;
	385	if (unlikely(atomic_read(&monpriv->iucv_severed)))
	386	return -EIO;
	387	monmsg = monpriv->msg_array[monpriv->read_index];
	388	}
	389
2ca5b6e2	390	if (!monmsg->pos)
1da177e4	391	monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset;
1da177e4 LT	392	if (mon_check_mca(monmsg))
	393	goto reply;
	394
	395	/* read monitor control element (12 bytes) first */
	396	mce_start = mon_mca_start(monmsg) + monmsg->mca_offset;
	397	if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) {
	398	count = min(count, (size_t) mce_start + 12 - monmsg->pos);
	399	ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
	400	count);
	401	if (ret)
	402	return -EFAULT;
	403	monmsg->pos += count;
	404	if (monmsg->pos == mce_start + 12)
	405	monmsg->pos = mon_rec_start(monmsg);
	406	goto out_copy;
	407	}
	408
	409	/* read records */
	410	if (monmsg->pos <= mon_rec_end(monmsg)) {
	411	count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos
	412	+ 1);
	413	ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
	414	count);
	415	if (ret)
	416	return -EFAULT;
	417	monmsg->pos += count;
	418	if (monmsg->pos > mon_rec_end(monmsg))
	419	mon_next_mca(monmsg);
	420	goto out_copy;
	421	}
	422	reply:
	423	ret = mon_send_reply(monmsg, monpriv);
	424	return ret;
	425
	426	out_copy:
	427	*ppos += count;
	428	return count;
	429	}
	430
c667aac8	431	static unsigned int mon_poll(struct file filp, struct poll_table_struct p)
1da177e4 LT	432	{
	433	struct mon_private *monpriv = filp->private_data;
	434
	435	poll_wait(filp, &mon_read_wait_queue, p);
	436	if (unlikely(atomic_read(&monpriv->iucv_severed)))
	437	return POLLERR;
	438	if (atomic_read(&monpriv->read_ready))
	439	return POLLIN \| POLLRDNORM;
	440	return 0;
	441	}
	442
d54b1fdb	443	static const struct file_operations mon_fops = {
1da177e4 LT	444	.owner = THIS_MODULE,
	445	.open = &mon_open,
	446	.release = &mon_close,
	447	.read = &mon_read,
	448	.poll = &mon_poll,
6038f373	449	.llseek = noop_llseek,
1da177e4 LT	450	};
	451
	452	static struct miscdevice mon_dev = {
	453	.name = "monreader",
1da177e4 LT	454	.fops = &mon_fops,
	455	.minor = MISC_DYNAMIC_MINOR,
	456	};
	457
2b1e3e55 GS	458
	459	/******************************************************************************
	460	* suspend / resume *
	461	*****************************************************************************/
	462	static int monreader_freeze(struct device *dev)
	463	{
99357742	464	struct mon_private *monpriv = dev_get_drvdata(dev);
2b1e3e55 GS	465	int rc;
	466
	467	if (!monpriv)
	468	return 0;
	469	if (monpriv->path) {
	470	rc = iucv_path_sever(monpriv->path, user_data_sever);
	471	if (rc)
	472	pr_warning("Disconnecting the z/VM *MONITOR system "
	473	"service failed with rc=%i\n", rc);
	474	iucv_path_free(monpriv->path);
	475	}
	476	atomic_set(&monpriv->iucv_severed, 0);
	477	atomic_set(&monpriv->iucv_connected, 0);
	478	atomic_set(&monpriv->read_ready, 0);
	479	atomic_set(&monpriv->msglim_count, 0);
	480	monpriv->write_index = 0;
	481	monpriv->read_index = 0;
	482	monpriv->path = NULL;
	483	return 0;
	484	}
	485
	486	static int monreader_thaw(struct device *dev)
	487	{
4f0076f7	488	struct mon_private *monpriv = dev_get_drvdata(dev);
2b1e3e55 GS	489	int rc;
	490
	491	if (!monpriv)
	492	return 0;
	493	rc = -ENOMEM;
	494	monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL);
	495	if (!monpriv->path)
	496	goto out;
	497	rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler,
	498	MON_SERVICE, NULL, user_data_connect, monpriv);
	499	if (rc) {
	500	pr_err("Connecting to the z/VM *MONITOR system service "
	501	"failed with rc=%i\n", rc);
	502	goto out_path;
	503	}
	504	wait_event(mon_conn_wait_queue,
	505	atomic_read(&monpriv->iucv_connected) \|\|
	506	atomic_read(&monpriv->iucv_severed));
	507	if (atomic_read(&monpriv->iucv_severed))
	508	goto out_path;
	509	return 0;
	510	out_path:
	511	rc = -EIO;
	512	iucv_path_free(monpriv->path);
	513	monpriv->path = NULL;
	514	out:
	515	atomic_set(&monpriv->iucv_severed, 1);
	516	return rc;
	517	}
	518
	519	static int monreader_restore(struct device *dev)
	520	{
	521	int rc;
	522
	523	segment_unload(mon_dcss_name);
	524	rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
	525	&mon_dcss_start, &mon_dcss_end);
	526	if (rc < 0) {
	527	segment_warning(rc, mon_dcss_name);
	528	panic("fatal monreader resume error: no monitor dcss\n");
	529	}
	530	return monreader_thaw(dev);
	531	}
	532
47145210	533	static const struct dev_pm_ops monreader_pm_ops = {
2b1e3e55 GS	534	.freeze = monreader_freeze,
	535	.thaw = monreader_thaw,
	536	.restore = monreader_restore,
	537	};
	538
	539	static struct device_driver monreader_driver = {
	540	.name = "monreader",
	541	.bus = &iucv_bus,
	542	.pm = &monreader_pm_ops,
	543	};
	544
	545
1da177e4 LT	546	/******************************************************************************
	547	* module init/exit *
	548	*****************************************************************************/
c667aac8	549	static int __init mon_init(void)
1da177e4 LT	550	{
	551	int rc;
	552
	553	if (!MACHINE_IS_VM) {
a4f5a299 GS	554	pr_err("The z/VM *MONITOR record device driver cannot be "
a4f5a299 GS	555	"loaded without z/VM\n");
1da177e4 LT	556	return -ENODEV;
	557	}
	558
c667aac8 MS	559	/*
	560	* Register with IUCV and connect to *MONITOR service
	561	*/
	562	rc = iucv_register(&monreader_iucv_handler, 1);
	563	if (rc) {
a4f5a299 GS	564	pr_err("The z/VM *MONITOR record device driver failed to "
a4f5a299 GS	565	"register with IUCV\n");
c667aac8 MS	566	return rc;
c667aac8 MS	567	}
c667aac8	568
2b1e3e55 GS	569	rc = driver_register(&monreader_driver);
	570	if (rc)
	571	goto out_iucv;
	572	monreader_device = kzalloc(sizeof(struct device), GFP_KERNEL);
72abaadf PST	573	if (!monreader_device) {
72abaadf PST	574	rc = -ENOMEM;
2b1e3e55	575	goto out_driver;
72abaadf PST	576	}
72abaadf PST	577
2b1e3e55 GS	578	dev_set_name(monreader_device, "monreader-dev");
	579	monreader_device->bus = &iucv_bus;
	580	monreader_device->parent = iucv_root;
	581	monreader_device->driver = &monreader_driver;
	582	monreader_device->release = (void ()(struct device ))kfree;
	583	rc = device_register(monreader_device);
	584	if (rc) {
c6304933	585	put_device(monreader_device);
2b1e3e55 GS	586	goto out_driver;
	587	}
	588
1da177e4 LT	589	rc = segment_type(mon_dcss_name);
1da177e4 LT	590	if (rc < 0) {
ca68305b	591	segment_warning(rc, mon_dcss_name);
2b1e3e55	592	goto out_device;
1da177e4 LT	593	}
1da177e4 LT	594	if (rc != SEG_TYPE_SC) {
a4f5a299 GS	595	pr_err("The specified *MONITOR DCSS %s does not have the "
a4f5a299 GS	596	"required type SC\n", mon_dcss_name);
c667aac8	597	rc = -EINVAL;
2b1e3e55	598	goto out_device;
1da177e4 LT	599	}
	600
	601	rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
	602	&mon_dcss_start, &mon_dcss_end);
	603	if (rc < 0) {
ca68305b	604	segment_warning(rc, mon_dcss_name);
c667aac8	605	rc = -EINVAL;
2b1e3e55	606	goto out_device;
1da177e4 LT	607	}
	608	dcss_mkname(mon_dcss_name, &user_data_connect[8]);
	609
1963403a GS	610	/*
	611	* misc_register() has to be the last action in module_init(), because
	612	* file operations will be available right after this.
	613	*/
1da177e4	614	rc = misc_register(&mon_dev);
2ca5b6e2	615	if (rc < 0 )
1da177e4	616	goto out;
1da177e4 LT	617	return 0;
	618
	619	out:
	620	segment_unload(mon_dcss_name);
2b1e3e55 GS	621	out_device:
	622	device_unregister(monreader_device);
	623	out_driver:
	624	driver_unregister(&monreader_driver);
c667aac8 MS	625	out_iucv:
c667aac8 MS	626	iucv_unregister(&monreader_iucv_handler, 1);
1da177e4 LT	627	return rc;
	628	}
	629
c667aac8	630	static void __exit mon_exit(void)
1da177e4 LT	631	{
1da177e4 LT	632	segment_unload(mon_dcss_name);
547415d5	633	misc_deregister(&mon_dev);
2b1e3e55 GS	634	device_unregister(monreader_device);
2b1e3e55 GS	635	driver_unregister(&monreader_driver);
c667aac8	636	iucv_unregister(&monreader_iucv_handler, 1);
1da177e4 LT	637	return;
	638	}
	639
	640
	641	module_init(mon_init);
	642	module_exit(mon_exit);
	643
	644	module_param_string(mondcss, mon_dcss_name, 9, 0444);
	645	MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR "
	646	"service, max. 8 chars. Default is MONDCSS");
	647
	648	MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>");
	649	MODULE_DESCRIPTION("Character device driver for reading z/VM "
	650	"monitor service records.");
	651	MODULE_LICENSE("GPL");