1 files changed, 662 insertions, 0 deletions

diff --git a/drivers/s390/char/monreader.c b/drivers/s390/char/monreader.c
new file mode 100644
index 000000000000..5fd3ad867386
--- /dev/null
+++ b/drivers/s390/char/monreader.c
@@ -0,0 +1,662 @@
+/*
+ * drivers/s390/char/monreader.c
+ *
+ * Character device driver for reading z/VM *MONITOR service records.
+ *
+ * Copyright (C) 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH.
+ *
+ * Author: Gerald Schaefer <geraldsc@de.ibm.com>
+ */
+
+#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 <asm/uaccess.h>
+#include <asm/ebcdic.h>
+#include <asm/extmem.h>
+#include <linux/poll.h>
+#include "../net/iucv.h"
+
+
+//#define MON_DEBUG			/* Debug messages on/off */
+
+#define MON_NAME "monreader"
+
+#define P_INFO(x...)	printk(KERN_INFO MON_NAME " info: " x)
+#define P_ERROR(x...)	printk(KERN_ERR MON_NAME " error: " x)
+#define P_WARNING(x...)	printk(KERN_WARNING MON_NAME " warning: " x)
+
+#ifdef MON_DEBUG
+#define P_DEBUG(x...)   printk(KERN_DEBUG MON_NAME " debug: " x)
+#else
+#define P_DEBUG(x...)   do {} while (0)
+#endif
+
+#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;
+	iucv_MessagePending local_eib;
+	char msglim_reached;
+	char replied_msglim;
+};
+
+struct mon_private {
+	u16 pathid;
+	iucv_handle_t iucv_handle;
+	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 iucv_host[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+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,
+};
+
+
+/******************************************************************************
+ *                             helper functions                               *
+ *****************************************************************************/
+/*
+ * Create the 8 bytes EBCDIC DCSS segment name from
+ * an ASCII name, incl. padding
+ */
+static inline 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);
+}
+
+/*
+ * print appropriate error message for segment_load()/segment_type()
+ * return code
+ */
+static void
+mon_segment_warn(int rc, char* seg_name)
+{
+	switch (rc) {
+	case -ENOENT:
+		P_WARNING("cannot load/query segment %s, does not exist\n",
+			  seg_name);
+		break;
+	case -ENOSYS:
+		P_WARNING("cannot load/query segment %s, not running on VM\n",
+			  seg_name);
+		break;
+	case -EIO:
+		P_WARNING("cannot load/query segment %s, hardware error\n",
+			  seg_name);
+		break;
+	case -ENOTSUPP:
+		P_WARNING("cannot load/query segment %s, is a multi-part "
+			  "segment\n", seg_name);
+		break;
+	case -ENOSPC:
+		P_WARNING("cannot load/query segment %s, overlaps with "
+			  "storage\n", seg_name);
+		break;
+	case -EBUSY:
+		P_WARNING("cannot load/query segment %s, overlaps with "
+			  "already loaded dcss\n", seg_name);
+		break;
+	case -EPERM:
+		P_WARNING("cannot load/query segment %s, already loaded in "
+			  "incompatible mode\n", seg_name);
+		break;
+	case -ENOMEM:
+		P_WARNING("cannot load/query segment %s, out of memory\n",
+			  seg_name);
+		break;
+	case -ERANGE:
+		P_WARNING("cannot load/query segment %s, exceeds kernel "
+			  "mapping range\n", seg_name);
+		break;
+	default:
+		P_WARNING("cannot load/query segment %s, return value %i\n",
+			  seg_name, rc);
+		break;
+	}
+}
+
+static inline unsigned long
+mon_mca_start(struct mon_msg *monmsg)
+{
+	return monmsg->local_eib.ln1msg1.iprmmsg1_u32;
+}
+
+static inline unsigned long
+mon_mca_end(struct mon_msg *monmsg)
+{
+	return monmsg->local_eib.ln1msg2.ipbfln1f;
+}
+
+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 inline 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)))
+	{
+		P_DEBUG("READ, IGNORED INVALID MCA\n\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static inline int
+mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv)
+{
+	u8 prmmsg[8];
+	int rc;
+
+	P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = "
+		"0x%08X\n\n",
+		monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
+		monmsg->local_eib.iptrgcls);
+	rc = iucv_reply_prmmsg(monmsg->local_eib.ippathid,
+				monmsg->local_eib.ipmsgid,
+				monmsg->local_eib.iptrgcls,
+				0, prmmsg);
+	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) {
+		P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc);
+		return -EIO;
+	}
+	return 0;
+}
+
+static inline struct mon_private *
+mon_alloc_mem(void)
+{
+	int i,j;
+	struct mon_private *monpriv;
+
+	monpriv = kmalloc(sizeof(struct mon_private), GFP_KERNEL);
+	if (!monpriv) {
+		P_ERROR("no memory for monpriv\n");
+		return NULL;
+	}
+	memset(monpriv, 0, sizeof(struct mon_private));
+	for (i = 0; i < MON_MSGLIM; i++) {
+		monpriv->msg_array[i] = kmalloc(sizeof(struct mon_msg),
+						    GFP_KERNEL);
+		if (!monpriv->msg_array[i]) {
+			P_ERROR("open, no memory for msg_array\n");
+			for (j = 0; j < i; j++)
+				kfree(monpriv->msg_array[j]);
+			return NULL;
+		}
+		memset(monpriv->msg_array[i], 0, sizeof(struct mon_msg));
+	}
+	return monpriv;
+}
+
+static inline void
+mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv)
+{
+#ifdef MON_DEBUG
+	u8 msg_type[2], mca_type;
+	unsigned long records_len;
+
+	records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1;
+
+	memcpy(msg_type, &monmsg->local_eib.iptrgcls, 2);
+	EBCASC(msg_type, 2);
+	mca_type = mon_mca_type(monmsg, 0);
+	EBCASC(&mca_type, 1);
+
+	P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n",
+		monpriv->read_index, monpriv->write_index);
+	P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n",
+		monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
+		monmsg->local_eib.iptrgcls);
+	P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n",
+		msg_type[0], msg_type[1], mca_type ? mca_type : 'X',
+		mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2));
+	P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n",
+		mon_mca_start(monmsg), mon_mca_end(monmsg));
+	P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n",
+		mon_rec_start(monmsg), mon_rec_end(monmsg), records_len);
+	if (mon_mca_size(monmsg) > 12)
+		P_DEBUG("READ, MORE THAN ONE MCA\n\n");
+#endif
+}
+
+static inline void
+mon_next_mca(struct mon_msg *monmsg)
+{
+	if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
+		return;
+	P_DEBUG("READ, NEXT MCA\n\n");
+	monmsg->mca_offset += 12;
+	monmsg->pos = 0;
+}
+
+static inline 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;
+		P_WARNING("read, message limit reached\n");
+		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_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data)
+{
+	struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+	P_DEBUG("IUCV connection completed\n");
+	P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = "
+		"0x%02X, Sample = 0x%02X\n",
+		eib->ipuser[0], eib->ipuser[1], eib->ipuser[2]);
+	atomic_set(&monpriv->iucv_connected, 1);
+	wake_up(&mon_conn_wait_queue);
+}
+
+static void
+mon_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data)
+{
+	struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+	P_ERROR("IUCV connection severed with rc = 0x%X\n",
+		(u8) eib->ipuser[0]);
+	atomic_set(&monpriv->iucv_severed, 1);
+	wake_up(&mon_conn_wait_queue);
+	wake_up_interruptible(&mon_read_wait_queue);
+}
+
+static void
+mon_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data)
+{
+	struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+	P_DEBUG("IUCV message pending\n");
+	memcpy(&monpriv->msg_array[monpriv->write_index]->local_eib, eib,
+	       sizeof(iucv_MessagePending));
+	if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
+		P_WARNING("IUCV message pending, message limit (%i) reached\n",
+			  MON_MSGLIM);
+		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 iucv_interrupt_ops_t mon_iucvops = {
+	.ConnectionComplete = mon_iucv_ConnectionComplete,
+	.ConnectionSevered  = mon_iucv_ConnectionSevered,
+	.MessagePending     = mon_iucv_MessagePending,
+};
+
+/******************************************************************************
+ *                               file operations                              *
+ *****************************************************************************/
+static int
+mon_open(struct inode *inode, struct file *filp)
+{
+	int rc, i;
+	struct mon_private *monpriv;
+
+	/*
+	 * only one user allowed
+	 */
+	if (test_and_set_bit(MON_IN_USE, &mon_in_use))
+		return -EBUSY;
+
+	monpriv = mon_alloc_mem();
+	if (!monpriv)
+		return -ENOMEM;
+
+	/*
+	 * Register with IUCV and connect to *MONITOR service
+	 */
+	monpriv->iucv_handle = iucv_register_program("my_monreader    ",
+							MON_SERVICE,
+							NULL,
+							&mon_iucvops,
+							monpriv);
+	if (!monpriv->iucv_handle) {
+		P_ERROR("failed to register with iucv driver\n");
+		rc = -EIO;
+		goto out_error;
+	}
+	P_INFO("open, registered with IUCV\n");
+
+	rc = iucv_connect(&monpriv->pathid, MON_MSGLIM, user_data_connect,
+			  MON_SERVICE, iucv_host, IPRMDATA, NULL, NULL,
+			  monpriv->iucv_handle, NULL);
+	if (rc) {
+		P_ERROR("iucv connection to *MONITOR failed with "
+			"IPUSER SEVER code = %i\n", rc);
+		rc = -EIO;
+		goto out_unregister;
+	}
+	/*
+	 * 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_unregister;
+	}
+	P_INFO("open, established connection to *MONITOR service\n\n");
+	filp->private_data = monpriv;
+	return nonseekable_open(inode, filp);
+
+out_unregister:
+	iucv_unregister_program(monpriv->iucv_handle);
+out_error:
+	for (i = 0; i < MON_MSGLIM; i++)
+		kfree(monpriv->msg_array[i]);
+	kfree(monpriv);
+	clear_bit(MON_IN_USE, &mon_in_use);
+	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
+	 */
+	rc = iucv_sever(monpriv->pathid, user_data_sever);
+	if (rc)
+		P_ERROR("close, iucv_sever failed with rc = %i\n", rc);
+	else
+		P_INFO("close, terminated connection to *MONITOR service\n");
+
+	rc = iucv_unregister_program(monpriv->iucv_handle);
+	if (rc)
+		P_ERROR("close, iucv_unregister failed with rc = %i\n", rc);
+	else
+		P_INFO("close, unregistered with IUCV\n");
+
+	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;
+
+	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;
+		mon_read_debug(monmsg, monpriv);
+	}
+	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 struct file_operations mon_fops = {
+	.owner   = THIS_MODULE,
+	.open    = &mon_open,
+	.release = &mon_close,
+	.read    = &mon_read,
+	.poll    = &mon_poll,
+};
+
+static struct miscdevice mon_dev = {
+	.name       = "monreader",
+	.devfs_name = "monreader",
+	.fops       = &mon_fops,
+	.minor      = MISC_DYNAMIC_MINOR,
+};
+
+/******************************************************************************
+ *                              module init/exit                              *
+ *****************************************************************************/
+static int __init
+mon_init(void)
+{
+	int rc;
+
+	if (!MACHINE_IS_VM) {
+		P_ERROR("not running under z/VM, driver not loaded\n");
+		return -ENODEV;
+	}
+
+	rc = segment_type(mon_dcss_name);
+	if (rc < 0) {
+		mon_segment_warn(rc, mon_dcss_name);
+		return rc;
+	}
+	if (rc != SEG_TYPE_SC) {
+		P_ERROR("segment %s has unsupported type, should be SC\n",
+			mon_dcss_name);
+		return -EINVAL;
+	}
+
+	rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
+			  &mon_dcss_start, &mon_dcss_end);
+	if (rc < 0) {
+		mon_segment_warn(rc, mon_dcss_name);
+		return -EINVAL;
+	}
+	dcss_mkname(mon_dcss_name, &user_data_connect[8]);
+
+	rc = misc_register(&mon_dev);
+	if (rc < 0 ) {
+		P_ERROR("misc_register failed, rc = %i\n", rc);
+		goto out;
+	}
+	P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n",
+		mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end,
+		mon_dcss_end - mon_dcss_start + 1);
+	return 0;
+
+out:
+	segment_unload(mon_dcss_name);
+	return rc;
+}
+
+static void __exit
+mon_exit(void)
+{
+	segment_unload(mon_dcss_name);
+	WARN_ON(misc_deregister(&mon_dev) != 0);
+	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");