/*
* drivers/s390/char/monreader.c
*
* Character device driver for reading z/VM *MONITOR service records.
*
* Copyright 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/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;
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,
};
/******************************************************************************
* 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 *(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 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)
{
int rc;
P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = "
"0x%08X\n\n",
monpriv->path->pathid, monmsg->msg.id, monmsg->msg.class);
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) {
P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc);
return -EIO;
}
return 0;
}
static inline void mon_free_mem(struct mon_private *monpriv)
{
int i;
for (i = 0; i < MON_MSGLIM; i++)
if (monpriv->msg_array[i])
kfree(monpriv->msg_array[i]);
kfree(monpriv);
}
static inline struct mon_private *mon_alloc_mem(void)
{
int i;
struct mon_private *monpriv;
monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
if (!monpriv) {
P_ERROR("no memory for monpriv\n");
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]) {
P_ERROR("open, no memory for msg_array\n");
mon_free_mem(monpriv);
return NULL;
}
}
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->msg.class, 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",
monpriv->path->pathid, monmsg->msg.id, monmsg->msg.class);
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_path_complete(struct iucv_path *path, u8 ipuser[16])
{
struct mon_private *monpriv = path->private;
P_DEBUG("IUCV connection completed\n");
P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = "
"0x%02X, Sample = 0x%02X\n",
ipuser[0], ipuser[1], ipuser[2]);
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;
P_ERROR("IUCV connection severed with rc = 0x%X\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;
P_DEBUG("IUCV message pending\n");
memcpy(&monpriv->msg_array[monpriv->write_index]->msg,
msg, sizeof(*msg));
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 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) {
P_ERROR("iucv connection to *MONITOR failed with "
"IPUSER SEVER code = %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;
}
P_INFO("open, established connection to *MONITOR service\n\n");
filp->private_data = monpriv;
return nonseekable_open(inode, filp);
out_path:
kfree(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
*/
rc = iucv_path_sever(monpriv->path, 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");
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",
.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;
}
/*
* Register with IUCV and connect to *MONITOR service
*/
rc = iucv_register(&monreader_iucv_handler, 1);
if (rc) {
P_ERROR("failed to register with iucv driver\n");
return rc;
}
P_INFO("open, registered with IUCV\n");
rc = segment_type(mon_dcss_name);
if (rc < 0) {
mon_segment_warn(rc, mon_dcss_name);
goto out_iucv;
}
if (rc != SEG_TYPE_SC) {
P_ERROR("segment %s has unsupported type, should be SC\n",
mon_dcss_name);
rc = -EINVAL;
goto out_iucv;
}
rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
&mon_dcss_start, &mon_dcss_end);
if (rc < 0) {
mon_segment_warn(rc, mon_dcss_name);
rc = -EINVAL;
goto out_iucv;
}
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);
out_iucv:
iucv_unregister(&monreader_iucv_handler, 1);
return rc;
}
static void __exit mon_exit(void)
{
segment_unload(mon_dcss_name);
WARN_ON(misc_deregister(&mon_dev) != 0);
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");
