4 * A watchdog timer based upon the IPMI interface.
6 * Author: MontaVista Software, Inc.
7 * Corey Minyard <minyard@mvista.com>
10 * Copyright 2002 MontaVista Software Inc.
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
26 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
27 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 * You should have received a copy of the GNU General Public License along
30 * with this program; if not, write to the Free Software Foundation, Inc.,
31 * 675 Mass Ave, Cambridge, MA 02139, USA.
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/ipmi.h>
37 #include <linux/ipmi_smi.h>
38 #include <linux/watchdog.h>
39 #include <linux/miscdevice.h>
40 #include <linux/init.h>
41 #include <linux/completion.h>
42 #include <linux/kdebug.h>
43 #include <linux/rwsem.h>
44 #include <linux/errno.h>
45 #include <asm/uaccess.h>
46 #include <linux/notifier.h>
47 #include <linux/nmi.h>
48 #include <linux/reboot.h>
49 #include <linux/wait.h>
50 #include <linux/poll.h>
51 #include <linux/string.h>
52 #include <linux/ctype.h>
53 #include <linux/delay.h>
54 #include <asm/atomic.h>
58 * This is ugly, but I've determined that x86 is the only architecture
59 * that can reasonably support the IPMI NMI watchdog timeout at this
60 * time. If another architecture adds this capability somehow, it
61 * will have to be a somewhat different mechanism and I have no idea
62 * how it will work. So in the unlikely event that another
63 * architecture supports this, we can figure out a good generic
64 * mechanism for it at that time.
66 #include <asm/kdebug.h>
70 #define PFX "IPMI Watchdog: "
73 * The IPMI command/response information for the watchdog timer.
76 /* values for byte 1 of the set command, byte 2 of the get response. */
77 #define WDOG_DONT_LOG (1 << 7)
78 #define WDOG_DONT_STOP_ON_SET (1 << 6)
79 #define WDOG_SET_TIMER_USE(byte, use) \
80 byte = ((byte) & 0xf8) | ((use) & 0x7)
81 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
82 #define WDOG_TIMER_USE_BIOS_FRB2 1
83 #define WDOG_TIMER_USE_BIOS_POST 2
84 #define WDOG_TIMER_USE_OS_LOAD 3
85 #define WDOG_TIMER_USE_SMS_OS 4
86 #define WDOG_TIMER_USE_OEM 5
88 /* values for byte 2 of the set command, byte 3 of the get response. */
89 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
90 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
91 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
92 #define WDOG_PRETIMEOUT_NONE 0
93 #define WDOG_PRETIMEOUT_SMI 1
94 #define WDOG_PRETIMEOUT_NMI 2
95 #define WDOG_PRETIMEOUT_MSG_INT 3
97 /* Operations that can be performed on a pretimout. */
98 #define WDOG_PREOP_NONE 0
99 #define WDOG_PREOP_PANIC 1
100 /* Cause data to be available to read. Doesn't work in NMI mode. */
101 #define WDOG_PREOP_GIVE_DATA 2
103 /* Actions to perform on a full timeout. */
104 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
105 byte = ((byte) & 0xf8) | ((use) & 0x7)
106 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
107 #define WDOG_TIMEOUT_NONE 0
108 #define WDOG_TIMEOUT_RESET 1
109 #define WDOG_TIMEOUT_POWER_DOWN 2
110 #define WDOG_TIMEOUT_POWER_CYCLE 3
113 * Byte 3 of the get command, byte 4 of the get response is the
114 * pre-timeout in seconds.
117 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
118 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1)
119 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2)
120 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3)
121 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4)
122 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5)
125 * Setting/getting the watchdog timer value. This is for bytes 5 and
126 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
127 * timeout time) and 8 and 9 (the current countdown value) of the
128 * response. The timeout value is given in seconds (in the command it
129 * is 100ms intervals).
131 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
132 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
133 #define WDOG_GET_TIMEOUT(byte1, byte2) \
134 (((byte1) | ((byte2) << 8)) / 10)
136 #define IPMI_WDOG_RESET_TIMER 0x22
137 #define IPMI_WDOG_SET_TIMER 0x24
138 #define IPMI_WDOG_GET_TIMER 0x25
140 /* These are here until the real ones get into the watchdog.h interface. */
141 #ifndef WDIOC_GETTIMEOUT
142 #define WDIOC_GETTIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 20, int)
144 #ifndef WDIOC_SET_PRETIMEOUT
145 #define WDIOC_SET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 21, int)
147 #ifndef WDIOC_GET_PRETIMEOUT
148 #define WDIOC_GET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 22, int)
151 static int nowayout = WATCHDOG_NOWAYOUT;
153 static ipmi_user_t watchdog_user;
154 static int watchdog_ifnum;
156 /* Default the timeout to 10 seconds. */
157 static int timeout = 10;
159 /* The pre-timeout is disabled by default. */
160 static int pretimeout;
162 /* Default action is to reset the board on a timeout. */
163 static unsigned char action_val = WDOG_TIMEOUT_RESET;
165 static char action[16] = "reset";
167 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
169 static char preaction[16] = "pre_none";
171 static unsigned char preop_val = WDOG_PREOP_NONE;
173 static char preop[16] = "preop_none";
174 static DEFINE_SPINLOCK(ipmi_read_lock);
175 static char data_to_read;
176 static DECLARE_WAIT_QUEUE_HEAD(read_q);
177 static struct fasync_struct *fasync_q;
178 static char pretimeout_since_last_heartbeat;
179 static char expect_close;
181 static int ifnum_to_use = -1;
183 /* Parameters to ipmi_set_timeout */
184 #define IPMI_SET_TIMEOUT_NO_HB 0
185 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1
186 #define IPMI_SET_TIMEOUT_FORCE_HB 2
188 static int ipmi_set_timeout(int do_heartbeat);
189 static void ipmi_register_watchdog(int ipmi_intf);
190 static void ipmi_unregister_watchdog(int ipmi_intf);
193 * If true, the driver will start running as soon as it is configured
196 static int start_now;
198 static int set_param_int(const char *val, struct kernel_param *kp)
206 l = simple_strtoul(val, &endp, 0);
210 *((int *)kp->arg) = l;
212 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
217 static int get_param_int(char *buffer, struct kernel_param *kp)
219 return sprintf(buffer, "%i", *((int *)kp->arg));
222 typedef int (*action_fn)(const char *intval, char *outval);
224 static int action_op(const char *inval, char *outval);
225 static int preaction_op(const char *inval, char *outval);
226 static int preop_op(const char *inval, char *outval);
227 static void check_parms(void);
229 static int set_param_str(const char *val, struct kernel_param *kp)
231 action_fn fn = (action_fn) kp->arg;
236 strncpy(valcp, val, 16);
247 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
253 static int get_param_str(char *buffer, struct kernel_param *kp)
255 action_fn fn = (action_fn) kp->arg;
258 rv = fn(NULL, buffer);
261 return strlen(buffer);
265 static int set_param_wdog_ifnum(const char *val, struct kernel_param *kp)
267 int rv = param_set_int(val, kp);
270 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
273 ipmi_unregister_watchdog(watchdog_ifnum);
274 ipmi_register_watchdog(ifnum_to_use);
278 module_param_call(ifnum_to_use, set_param_wdog_ifnum, get_param_int,
279 &ifnum_to_use, 0644);
280 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
281 "timer. Setting to -1 defaults to the first registered "
284 module_param_call(timeout, set_param_int, get_param_int, &timeout, 0644);
285 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
287 module_param_call(pretimeout, set_param_int, get_param_int, &pretimeout, 0644);
288 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
290 module_param_call(action, set_param_str, get_param_str, action_op, 0644);
291 MODULE_PARM_DESC(action, "Timeout action. One of: "
292 "reset, none, power_cycle, power_off.");
294 module_param_call(preaction, set_param_str, get_param_str, preaction_op, 0644);
295 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "
296 "pre_none, pre_smi, pre_nmi, pre_int.");
298 module_param_call(preop, set_param_str, get_param_str, preop_op, 0644);
299 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "
300 "preop_none, preop_panic, preop_give_data.");
302 module_param(start_now, int, 0444);
303 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
304 "soon as the driver is loaded.");
306 module_param(nowayout, int, 0644);
307 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
308 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
310 /* Default state of the timer. */
311 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
313 /* If shutting down via IPMI, we ignore the heartbeat. */
314 static int ipmi_ignore_heartbeat;
316 /* Is someone using the watchdog? Only one user is allowed. */
317 static unsigned long ipmi_wdog_open;
320 * If set to 1, the heartbeat command will set the state to reset and
321 * start the timer. The timer doesn't normally run when the driver is
322 * first opened until the heartbeat is set the first time, this
323 * variable is used to accomplish this.
325 static int ipmi_start_timer_on_heartbeat;
327 /* IPMI version of the BMC. */
328 static unsigned char ipmi_version_major;
329 static unsigned char ipmi_version_minor;
331 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
332 static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
335 static int testing_nmi;
336 static int nmi_handler_registered;
339 static int ipmi_heartbeat(void);
342 * We use a mutex to make sure that only one thing can send a set
343 * timeout at one time, because we only have one copy of the data.
344 * The mutex is claimed when the set_timeout is sent and freed
345 * when both messages are free.
347 static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
348 static DEFINE_MUTEX(set_timeout_lock);
349 static DECLARE_COMPLETION(set_timeout_wait);
350 static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
352 if (atomic_dec_and_test(&set_timeout_tofree))
353 complete(&set_timeout_wait);
355 static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
357 if (atomic_dec_and_test(&set_timeout_tofree))
358 complete(&set_timeout_wait);
360 static struct ipmi_smi_msg set_timeout_smi_msg = {
361 .done = set_timeout_free_smi
363 static struct ipmi_recv_msg set_timeout_recv_msg = {
364 .done = set_timeout_free_recv
367 static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg,
368 struct ipmi_recv_msg *recv_msg,
369 int *send_heartbeat_now)
371 struct kernel_ipmi_msg msg;
372 unsigned char data[6];
374 struct ipmi_system_interface_addr addr;
378 /* These can be cleared as we are setting the timeout. */
379 pretimeout_since_last_heartbeat = 0;
382 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
384 if ((ipmi_version_major > 1)
385 || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
386 /* This is an IPMI 1.5-only feature. */
387 data[0] |= WDOG_DONT_STOP_ON_SET;
388 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
390 * In ipmi 1.0, setting the timer stops the watchdog, we
391 * need to start it back up again.
397 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
398 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
399 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
400 data[2] = pretimeout;
402 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
403 data[2] = 0; /* No pretimeout. */
406 WDOG_SET_TIMEOUT(data[4], data[5], timeout);
408 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
409 addr.channel = IPMI_BMC_CHANNEL;
413 msg.cmd = IPMI_WDOG_SET_TIMER;
415 msg.data_len = sizeof(data);
416 rv = ipmi_request_supply_msgs(watchdog_user,
417 (struct ipmi_addr *) &addr,
425 printk(KERN_WARNING PFX "set timeout error: %d\n",
429 if (send_heartbeat_now)
430 *send_heartbeat_now = hbnow;
435 static int ipmi_set_timeout(int do_heartbeat)
437 int send_heartbeat_now;
441 /* We can only send one of these at a time. */
442 mutex_lock(&set_timeout_lock);
444 atomic_set(&set_timeout_tofree, 2);
446 rv = i_ipmi_set_timeout(&set_timeout_smi_msg,
447 &set_timeout_recv_msg,
448 &send_heartbeat_now);
450 mutex_unlock(&set_timeout_lock);
454 wait_for_completion(&set_timeout_wait);
456 mutex_unlock(&set_timeout_lock);
458 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
459 || ((send_heartbeat_now)
460 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
461 rv = ipmi_heartbeat();
467 static atomic_t panic_done_count = ATOMIC_INIT(0);
469 static void panic_smi_free(struct ipmi_smi_msg *msg)
471 atomic_dec(&panic_done_count);
473 static void panic_recv_free(struct ipmi_recv_msg *msg)
475 atomic_dec(&panic_done_count);
478 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
479 .done = panic_smi_free
481 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
482 .done = panic_recv_free
485 static void panic_halt_ipmi_heartbeat(void)
487 struct kernel_ipmi_msg msg;
488 struct ipmi_system_interface_addr addr;
492 * Don't reset the timer if we have the timer turned off, that
493 * re-enables the watchdog.
495 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
498 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
499 addr.channel = IPMI_BMC_CHANNEL;
503 msg.cmd = IPMI_WDOG_RESET_TIMER;
506 rv = ipmi_request_supply_msgs(watchdog_user,
507 (struct ipmi_addr *) &addr,
511 &panic_halt_heartbeat_smi_msg,
512 &panic_halt_heartbeat_recv_msg,
515 atomic_add(2, &panic_done_count);
518 static struct ipmi_smi_msg panic_halt_smi_msg = {
519 .done = panic_smi_free
521 static struct ipmi_recv_msg panic_halt_recv_msg = {
522 .done = panic_recv_free
526 * Special call, doesn't claim any locks. This is only to be called
527 * at panic or halt time, in run-to-completion mode, when the caller
528 * is the only CPU and the only thing that will be going is these IPMI
531 static void panic_halt_ipmi_set_timeout(void)
533 int send_heartbeat_now;
536 /* Wait for the messages to be free. */
537 while (atomic_read(&panic_done_count) != 0)
538 ipmi_poll_interface(watchdog_user);
539 rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
540 &panic_halt_recv_msg,
541 &send_heartbeat_now);
543 atomic_add(2, &panic_done_count);
544 if (send_heartbeat_now)
545 panic_halt_ipmi_heartbeat();
547 printk(KERN_WARNING PFX
548 "Unable to extend the watchdog timeout.");
549 while (atomic_read(&panic_done_count) != 0)
550 ipmi_poll_interface(watchdog_user);
554 * We use a mutex to make sure that only one thing can send a
555 * heartbeat at one time, because we only have one copy of the data.
556 * The semaphore is claimed when the set_timeout is sent and freed
557 * when both messages are free.
559 static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
560 static DEFINE_MUTEX(heartbeat_lock);
561 static DECLARE_COMPLETION(heartbeat_wait);
562 static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
564 if (atomic_dec_and_test(&heartbeat_tofree))
565 complete(&heartbeat_wait);
567 static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
569 if (atomic_dec_and_test(&heartbeat_tofree))
570 complete(&heartbeat_wait);
572 static struct ipmi_smi_msg heartbeat_smi_msg = {
573 .done = heartbeat_free_smi
575 static struct ipmi_recv_msg heartbeat_recv_msg = {
576 .done = heartbeat_free_recv
579 static int ipmi_heartbeat(void)
581 struct kernel_ipmi_msg msg;
583 struct ipmi_system_interface_addr addr;
585 if (ipmi_ignore_heartbeat)
588 if (ipmi_start_timer_on_heartbeat) {
589 ipmi_start_timer_on_heartbeat = 0;
590 ipmi_watchdog_state = action_val;
591 return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
592 } else if (pretimeout_since_last_heartbeat) {
594 * A pretimeout occurred, make sure we set the timeout.
595 * We don't want to set the action, though, we want to
596 * leave that alone (thus it can't be combined with the
599 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
602 mutex_lock(&heartbeat_lock);
604 atomic_set(&heartbeat_tofree, 2);
607 * Don't reset the timer if we have the timer turned off, that
608 * re-enables the watchdog.
610 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
611 mutex_unlock(&heartbeat_lock);
615 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
616 addr.channel = IPMI_BMC_CHANNEL;
620 msg.cmd = IPMI_WDOG_RESET_TIMER;
623 rv = ipmi_request_supply_msgs(watchdog_user,
624 (struct ipmi_addr *) &addr,
632 mutex_unlock(&heartbeat_lock);
633 printk(KERN_WARNING PFX "heartbeat failure: %d\n",
638 /* Wait for the heartbeat to be sent. */
639 wait_for_completion(&heartbeat_wait);
641 if (heartbeat_recv_msg.msg.data[0] != 0) {
643 * Got an error in the heartbeat response. It was already
644 * reported in ipmi_wdog_msg_handler, but we should return
650 mutex_unlock(&heartbeat_lock);
655 static struct watchdog_info ident = {
656 .options = 0, /* WDIOF_SETTIMEOUT, */
657 .firmware_version = 1,
661 static int ipmi_ioctl(struct inode *inode, struct file *file,
662 unsigned int cmd, unsigned long arg)
664 void __user *argp = (void __user *)arg;
669 case WDIOC_GETSUPPORT:
670 i = copy_to_user(argp, &ident, sizeof(ident));
671 return i ? -EFAULT : 0;
673 case WDIOC_SETTIMEOUT:
674 i = copy_from_user(&val, argp, sizeof(int));
678 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
680 case WDIOC_GETTIMEOUT:
681 i = copy_to_user(argp, &timeout, sizeof(timeout));
686 case WDIOC_SET_PRETIMEOUT:
687 case WDIOC_SETPRETIMEOUT:
688 i = copy_from_user(&val, argp, sizeof(int));
692 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
694 case WDIOC_GET_PRETIMEOUT:
695 case WDIOC_GETPRETIMEOUT:
696 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
701 case WDIOC_KEEPALIVE:
702 return ipmi_heartbeat();
704 case WDIOC_SETOPTIONS:
705 i = copy_from_user(&val, argp, sizeof(int));
708 if (val & WDIOS_DISABLECARD) {
709 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
710 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
711 ipmi_start_timer_on_heartbeat = 0;
714 if (val & WDIOS_ENABLECARD) {
715 ipmi_watchdog_state = action_val;
716 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
720 case WDIOC_GETSTATUS:
722 i = copy_to_user(argp, &val, sizeof(val));
732 static ssize_t ipmi_write(struct file *file,
733 const char __user *buf,
743 /* In case it was set long ago */
746 for (i = 0; i != len; i++) {
749 if (get_user(c, buf + i))
755 rv = ipmi_heartbeat();
762 static ssize_t ipmi_read(struct file *file,
774 * Reading returns if the pretimeout has gone off, and it only does
775 * it once per pretimeout.
777 spin_lock(&ipmi_read_lock);
779 if (file->f_flags & O_NONBLOCK) {
784 init_waitqueue_entry(&wait, current);
785 add_wait_queue(&read_q, &wait);
786 while (!data_to_read) {
787 set_current_state(TASK_INTERRUPTIBLE);
788 spin_unlock(&ipmi_read_lock);
790 spin_lock(&ipmi_read_lock);
792 remove_wait_queue(&read_q, &wait);
794 if (signal_pending(current)) {
802 spin_unlock(&ipmi_read_lock);
805 if (copy_to_user(buf, &data_to_read, 1))
814 static int ipmi_open(struct inode *ino, struct file *filep)
816 switch (iminor(ino)) {
818 if (test_and_set_bit(0, &ipmi_wdog_open))
822 * Don't start the timer now, let it start on the
825 ipmi_start_timer_on_heartbeat = 1;
826 return nonseekable_open(ino, filep);
833 static unsigned int ipmi_poll(struct file *file, poll_table *wait)
835 unsigned int mask = 0;
837 poll_wait(file, &read_q, wait);
839 spin_lock(&ipmi_read_lock);
841 mask |= (POLLIN | POLLRDNORM);
842 spin_unlock(&ipmi_read_lock);
847 static int ipmi_fasync(int fd, struct file *file, int on)
851 result = fasync_helper(fd, file, on, &fasync_q);
856 static int ipmi_close(struct inode *ino, struct file *filep)
858 if (iminor(ino) == WATCHDOG_MINOR) {
859 if (expect_close == 42) {
860 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
861 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
864 "Unexpected close, not stopping watchdog!\n");
867 clear_bit(0, &ipmi_wdog_open);
870 ipmi_fasync(-1, filep, 0);
876 static const struct file_operations ipmi_wdog_fops = {
877 .owner = THIS_MODULE,
883 .release = ipmi_close,
884 .fasync = ipmi_fasync,
887 static struct miscdevice ipmi_wdog_miscdev = {
888 .minor = WATCHDOG_MINOR,
890 .fops = &ipmi_wdog_fops
893 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
896 if (msg->msg.data[0] != 0) {
897 printk(KERN_ERR PFX "response: Error %x on cmd %x\n",
902 ipmi_free_recv_msg(msg);
905 static void ipmi_wdog_pretimeout_handler(void *handler_data)
907 if (preaction_val != WDOG_PRETIMEOUT_NONE) {
908 if (preop_val == WDOG_PREOP_PANIC) {
909 if (atomic_inc_and_test(&preop_panic_excl))
910 panic("Watchdog pre-timeout");
911 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
912 spin_lock(&ipmi_read_lock);
914 wake_up_interruptible(&read_q);
915 kill_fasync(&fasync_q, SIGIO, POLL_IN);
917 spin_unlock(&ipmi_read_lock);
922 * On some machines, the heartbeat will give an error and not
923 * work unless we re-enable the timer. So do so.
925 pretimeout_since_last_heartbeat = 1;
928 static struct ipmi_user_hndl ipmi_hndlrs = {
929 .ipmi_recv_hndl = ipmi_wdog_msg_handler,
930 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler
933 static void ipmi_register_watchdog(int ipmi_intf)
940 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
943 watchdog_ifnum = ipmi_intf;
945 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
947 printk(KERN_CRIT PFX "Unable to register with ipmi\n");
951 ipmi_get_version(watchdog_user,
953 &ipmi_version_minor);
955 rv = misc_register(&ipmi_wdog_miscdev);
957 ipmi_destroy_user(watchdog_user);
958 watchdog_user = NULL;
959 printk(KERN_CRIT PFX "Unable to register misc device\n");
963 if (nmi_handler_registered) {
964 int old_pretimeout = pretimeout;
965 int old_timeout = timeout;
966 int old_preop_val = preop_val;
969 * Set the pretimeout to go off in a second and give
970 * ourselves plenty of time to stop the timer.
972 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
973 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
979 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
981 printk(KERN_WARNING PFX "Error starting timer to"
982 " test NMI: 0x%x. The NMI pretimeout will"
983 " likely not work\n", rv);
990 if (testing_nmi != 2) {
991 printk(KERN_WARNING PFX "IPMI NMI didn't seem to"
992 " occur. The NMI pretimeout will"
993 " likely not work\n");
997 preop_val = old_preop_val;
998 pretimeout = old_pretimeout;
999 timeout = old_timeout;
1004 if ((start_now) && (rv == 0)) {
1005 /* Run from startup, so start the timer now. */
1006 start_now = 0; /* Disable this function after first startup. */
1007 ipmi_watchdog_state = action_val;
1008 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1009 printk(KERN_INFO PFX "Starting now!\n");
1011 /* Stop the timer now. */
1012 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1013 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1017 static void ipmi_unregister_watchdog(int ipmi_intf)
1024 if (watchdog_ifnum != ipmi_intf)
1027 /* Make sure no one can call us any more. */
1028 misc_deregister(&ipmi_wdog_miscdev);
1031 * Wait to make sure the message makes it out. The lower layer has
1032 * pointers to our buffers, we want to make sure they are done before
1033 * we release our memory.
1035 while (atomic_read(&set_timeout_tofree))
1036 schedule_timeout_uninterruptible(1);
1038 /* Disconnect from IPMI. */
1039 rv = ipmi_destroy_user(watchdog_user);
1041 printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
1044 watchdog_user = NULL;
1052 ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
1054 struct die_args *args = data;
1059 /* Hack, if it's a memory or I/O error, ignore it. */
1060 if (args->err & 0xc0)
1064 * If we get here, it's an NMI that's not a memory or I/O
1065 * error. We can't truly tell if it's from IPMI or not
1066 * without sending a message, and sending a message is almost
1067 * impossible because of locking.
1075 /* If we are not expecting a timeout, ignore it. */
1076 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1079 if (preaction_val != WDOG_PRETIMEOUT_NMI)
1083 * If no one else handled the NMI, we assume it was the IPMI
1086 if (preop_val == WDOG_PREOP_PANIC) {
1087 /* On some machines, the heartbeat will give
1088 an error and not work unless we re-enable
1089 the timer. So do so. */
1090 pretimeout_since_last_heartbeat = 1;
1091 if (atomic_inc_and_test(&preop_panic_excl))
1092 panic(PFX "pre-timeout");
1098 static struct notifier_block ipmi_nmi_handler = {
1099 .notifier_call = ipmi_nmi
1103 static int wdog_reboot_handler(struct notifier_block *this,
1107 static int reboot_event_handled;
1109 if ((watchdog_user) && (!reboot_event_handled)) {
1110 /* Make sure we only do this once. */
1111 reboot_event_handled = 1;
1113 if (code == SYS_POWER_OFF || code == SYS_HALT) {
1114 /* Disable the WDT if we are shutting down. */
1115 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1116 panic_halt_ipmi_set_timeout();
1117 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1118 /* Set a long timer to let the reboot happens, but
1119 reboot if it hangs, but only if the watchdog
1120 timer was already running. */
1123 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1124 panic_halt_ipmi_set_timeout();
1130 static struct notifier_block wdog_reboot_notifier = {
1131 .notifier_call = wdog_reboot_handler,
1136 static int wdog_panic_handler(struct notifier_block *this,
1137 unsigned long event,
1140 static int panic_event_handled;
1142 /* On a panic, if we have a panic timeout, make sure to extend
1143 the watchdog timer to a reasonable value to complete the
1144 panic, if the watchdog timer is running. Plus the
1145 pretimeout is meaningless at panic time. */
1146 if (watchdog_user && !panic_event_handled &&
1147 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1148 /* Make sure we do this only once. */
1149 panic_event_handled = 1;
1153 panic_halt_ipmi_set_timeout();
1159 static struct notifier_block wdog_panic_notifier = {
1160 .notifier_call = wdog_panic_handler,
1162 .priority = 150 /* priority: INT_MAX >= x >= 0 */
1166 static void ipmi_new_smi(int if_num, struct device *device)
1168 ipmi_register_watchdog(if_num);
1171 static void ipmi_smi_gone(int if_num)
1173 ipmi_unregister_watchdog(if_num);
1176 static struct ipmi_smi_watcher smi_watcher = {
1177 .owner = THIS_MODULE,
1178 .new_smi = ipmi_new_smi,
1179 .smi_gone = ipmi_smi_gone
1182 static int action_op(const char *inval, char *outval)
1185 strcpy(outval, action);
1190 if (strcmp(inval, "reset") == 0)
1191 action_val = WDOG_TIMEOUT_RESET;
1192 else if (strcmp(inval, "none") == 0)
1193 action_val = WDOG_TIMEOUT_NONE;
1194 else if (strcmp(inval, "power_cycle") == 0)
1195 action_val = WDOG_TIMEOUT_POWER_CYCLE;
1196 else if (strcmp(inval, "power_off") == 0)
1197 action_val = WDOG_TIMEOUT_POWER_DOWN;
1200 strcpy(action, inval);
1204 static int preaction_op(const char *inval, char *outval)
1207 strcpy(outval, preaction);
1212 if (strcmp(inval, "pre_none") == 0)
1213 preaction_val = WDOG_PRETIMEOUT_NONE;
1214 else if (strcmp(inval, "pre_smi") == 0)
1215 preaction_val = WDOG_PRETIMEOUT_SMI;
1217 else if (strcmp(inval, "pre_nmi") == 0)
1218 preaction_val = WDOG_PRETIMEOUT_NMI;
1220 else if (strcmp(inval, "pre_int") == 0)
1221 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1224 strcpy(preaction, inval);
1228 static int preop_op(const char *inval, char *outval)
1231 strcpy(outval, preop);
1236 if (strcmp(inval, "preop_none") == 0)
1237 preop_val = WDOG_PREOP_NONE;
1238 else if (strcmp(inval, "preop_panic") == 0)
1239 preop_val = WDOG_PREOP_PANIC;
1240 else if (strcmp(inval, "preop_give_data") == 0)
1241 preop_val = WDOG_PREOP_GIVE_DATA;
1244 strcpy(preop, inval);
1248 static void check_parms(void)
1254 if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1256 if (preop_val == WDOG_PREOP_GIVE_DATA) {
1257 printk(KERN_WARNING PFX "Pretimeout op is to give data"
1258 " but NMI pretimeout is enabled, setting"
1259 " pretimeout op to none\n");
1260 preop_op("preop_none", NULL);
1264 if (do_nmi && !nmi_handler_registered) {
1265 rv = register_die_notifier(&ipmi_nmi_handler);
1267 printk(KERN_WARNING PFX
1268 "Can't register nmi handler\n");
1271 nmi_handler_registered = 1;
1272 } else if (!do_nmi && nmi_handler_registered) {
1273 unregister_die_notifier(&ipmi_nmi_handler);
1274 nmi_handler_registered = 0;
1279 static int __init ipmi_wdog_init(void)
1283 if (action_op(action, NULL)) {
1284 action_op("reset", NULL);
1285 printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
1286 " reset\n", action);
1289 if (preaction_op(preaction, NULL)) {
1290 preaction_op("pre_none", NULL);
1291 printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
1292 " none\n", preaction);
1295 if (preop_op(preop, NULL)) {
1296 preop_op("preop_none", NULL);
1297 printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
1303 register_reboot_notifier(&wdog_reboot_notifier);
1304 atomic_notifier_chain_register(&panic_notifier_list,
1305 &wdog_panic_notifier);
1307 rv = ipmi_smi_watcher_register(&smi_watcher);
1310 if (nmi_handler_registered)
1311 unregister_die_notifier(&ipmi_nmi_handler);
1313 atomic_notifier_chain_unregister(&panic_notifier_list,
1314 &wdog_panic_notifier);
1315 unregister_reboot_notifier(&wdog_reboot_notifier);
1316 printk(KERN_WARNING PFX "can't register smi watcher\n");
1320 printk(KERN_INFO PFX "driver initialized\n");
1325 static void __exit ipmi_wdog_exit(void)
1327 ipmi_smi_watcher_unregister(&smi_watcher);
1328 ipmi_unregister_watchdog(watchdog_ifnum);
1331 if (nmi_handler_registered)
1332 unregister_die_notifier(&ipmi_nmi_handler);
1335 atomic_notifier_chain_unregister(&panic_notifier_list,
1336 &wdog_panic_notifier);
1337 unregister_reboot_notifier(&wdog_reboot_notifier);
1339 module_exit(ipmi_wdog_exit);
1340 module_init(ipmi_wdog_init);
1341 MODULE_LICENSE("GPL");
1342 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1343 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");