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/smp_lock.h>
39 #include <linux/watchdog.h>
40 #include <linux/miscdevice.h>
41 #include <linux/init.h>
42 #include <linux/completion.h>
43 #include <linux/kdebug.h>
44 #include <linux/rwsem.h>
45 #include <linux/errno.h>
46 #include <asm/uaccess.h>
47 #include <linux/notifier.h>
48 #include <linux/nmi.h>
49 #include <linux/reboot.h>
50 #include <linux/wait.h>
51 #include <linux/poll.h>
52 #include <linux/string.h>
53 #include <linux/ctype.h>
54 #include <linux/delay.h>
55 #include <asm/atomic.h>
59 * This is ugly, but I've determined that x86 is the only architecture
60 * that can reasonably support the IPMI NMI watchdog timeout at this
61 * time. If another architecture adds this capability somehow, it
62 * will have to be a somewhat different mechanism and I have no idea
63 * how it will work. So in the unlikely event that another
64 * architecture supports this, we can figure out a good generic
65 * mechanism for it at that time.
67 #include <asm/kdebug.h>
71 #define PFX "IPMI Watchdog: "
74 * The IPMI command/response information for the watchdog timer.
77 /* values for byte 1 of the set command, byte 2 of the get response. */
78 #define WDOG_DONT_LOG (1 << 7)
79 #define WDOG_DONT_STOP_ON_SET (1 << 6)
80 #define WDOG_SET_TIMER_USE(byte, use) \
81 byte = ((byte) & 0xf8) | ((use) & 0x7)
82 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
83 #define WDOG_TIMER_USE_BIOS_FRB2 1
84 #define WDOG_TIMER_USE_BIOS_POST 2
85 #define WDOG_TIMER_USE_OS_LOAD 3
86 #define WDOG_TIMER_USE_SMS_OS 4
87 #define WDOG_TIMER_USE_OEM 5
89 /* values for byte 2 of the set command, byte 3 of the get response. */
90 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
91 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
92 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
93 #define WDOG_PRETIMEOUT_NONE 0
94 #define WDOG_PRETIMEOUT_SMI 1
95 #define WDOG_PRETIMEOUT_NMI 2
96 #define WDOG_PRETIMEOUT_MSG_INT 3
98 /* Operations that can be performed on a pretimout. */
99 #define WDOG_PREOP_NONE 0
100 #define WDOG_PREOP_PANIC 1
101 /* Cause data to be available to read. Doesn't work in NMI mode. */
102 #define WDOG_PREOP_GIVE_DATA 2
104 /* Actions to perform on a full timeout. */
105 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
106 byte = ((byte) & 0xf8) | ((use) & 0x7)
107 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
108 #define WDOG_TIMEOUT_NONE 0
109 #define WDOG_TIMEOUT_RESET 1
110 #define WDOG_TIMEOUT_POWER_DOWN 2
111 #define WDOG_TIMEOUT_POWER_CYCLE 3
114 * Byte 3 of the get command, byte 4 of the get response is the
115 * pre-timeout in seconds.
118 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
119 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1)
120 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2)
121 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3)
122 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4)
123 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5)
126 * Setting/getting the watchdog timer value. This is for bytes 5 and
127 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
128 * timeout time) and 8 and 9 (the current countdown value) of the
129 * response. The timeout value is given in seconds (in the command it
130 * is 100ms intervals).
132 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
133 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
134 #define WDOG_GET_TIMEOUT(byte1, byte2) \
135 (((byte1) | ((byte2) << 8)) / 10)
137 #define IPMI_WDOG_RESET_TIMER 0x22
138 #define IPMI_WDOG_SET_TIMER 0x24
139 #define IPMI_WDOG_GET_TIMER 0x25
141 /* These are here until the real ones get into the watchdog.h interface. */
142 #ifndef WDIOC_GETTIMEOUT
143 #define WDIOC_GETTIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 20, int)
145 #ifndef WDIOC_SET_PRETIMEOUT
146 #define WDIOC_SET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 21, int)
148 #ifndef WDIOC_GET_PRETIMEOUT
149 #define WDIOC_GET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 22, int)
152 static int nowayout = WATCHDOG_NOWAYOUT;
154 static ipmi_user_t watchdog_user;
155 static int watchdog_ifnum;
157 /* Default the timeout to 10 seconds. */
158 static int timeout = 10;
160 /* The pre-timeout is disabled by default. */
161 static int pretimeout;
163 /* Default action is to reset the board on a timeout. */
164 static unsigned char action_val = WDOG_TIMEOUT_RESET;
166 static char action[16] = "reset";
168 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
170 static char preaction[16] = "pre_none";
172 static unsigned char preop_val = WDOG_PREOP_NONE;
174 static char preop[16] = "preop_none";
175 static DEFINE_SPINLOCK(ipmi_read_lock);
176 static char data_to_read;
177 static DECLARE_WAIT_QUEUE_HEAD(read_q);
178 static struct fasync_struct *fasync_q;
179 static char pretimeout_since_last_heartbeat;
180 static char expect_close;
182 static int ifnum_to_use = -1;
184 /* Parameters to ipmi_set_timeout */
185 #define IPMI_SET_TIMEOUT_NO_HB 0
186 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1
187 #define IPMI_SET_TIMEOUT_FORCE_HB 2
189 static int ipmi_set_timeout(int do_heartbeat);
190 static void ipmi_register_watchdog(int ipmi_intf);
191 static void ipmi_unregister_watchdog(int ipmi_intf);
194 * If true, the driver will start running as soon as it is configured
197 static int start_now;
199 static int set_param_int(const char *val, struct kernel_param *kp)
207 l = simple_strtoul(val, &endp, 0);
211 *((int *)kp->arg) = l;
213 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
218 static int get_param_int(char *buffer, struct kernel_param *kp)
220 return sprintf(buffer, "%i", *((int *)kp->arg));
223 typedef int (*action_fn)(const char *intval, char *outval);
225 static int action_op(const char *inval, char *outval);
226 static int preaction_op(const char *inval, char *outval);
227 static int preop_op(const char *inval, char *outval);
228 static void check_parms(void);
230 static int set_param_str(const char *val, struct kernel_param *kp)
232 action_fn fn = (action_fn) kp->arg;
237 strncpy(valcp, val, 16);
248 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
254 static int get_param_str(char *buffer, struct kernel_param *kp)
256 action_fn fn = (action_fn) kp->arg;
259 rv = fn(NULL, buffer);
262 return strlen(buffer);
266 static int set_param_wdog_ifnum(const char *val, struct kernel_param *kp)
268 int rv = param_set_int(val, kp);
271 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
274 ipmi_unregister_watchdog(watchdog_ifnum);
275 ipmi_register_watchdog(ifnum_to_use);
279 module_param_call(ifnum_to_use, set_param_wdog_ifnum, get_param_int,
280 &ifnum_to_use, 0644);
281 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
282 "timer. Setting to -1 defaults to the first registered "
285 module_param_call(timeout, set_param_int, get_param_int, &timeout, 0644);
286 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
288 module_param_call(pretimeout, set_param_int, get_param_int, &pretimeout, 0644);
289 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
291 module_param_call(action, set_param_str, get_param_str, action_op, 0644);
292 MODULE_PARM_DESC(action, "Timeout action. One of: "
293 "reset, none, power_cycle, power_off.");
295 module_param_call(preaction, set_param_str, get_param_str, preaction_op, 0644);
296 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "
297 "pre_none, pre_smi, pre_nmi, pre_int.");
299 module_param_call(preop, set_param_str, get_param_str, preop_op, 0644);
300 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "
301 "preop_none, preop_panic, preop_give_data.");
303 module_param(start_now, int, 0444);
304 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
305 "soon as the driver is loaded.");
307 module_param(nowayout, int, 0644);
308 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
309 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
311 /* Default state of the timer. */
312 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
314 /* If shutting down via IPMI, we ignore the heartbeat. */
315 static int ipmi_ignore_heartbeat;
317 /* Is someone using the watchdog? Only one user is allowed. */
318 static unsigned long ipmi_wdog_open;
321 * If set to 1, the heartbeat command will set the state to reset and
322 * start the timer. The timer doesn't normally run when the driver is
323 * first opened until the heartbeat is set the first time, this
324 * variable is used to accomplish this.
326 static int ipmi_start_timer_on_heartbeat;
328 /* IPMI version of the BMC. */
329 static unsigned char ipmi_version_major;
330 static unsigned char ipmi_version_minor;
332 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
333 static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
336 static int testing_nmi;
337 static int nmi_handler_registered;
340 static int ipmi_heartbeat(void);
343 * We use a mutex to make sure that only one thing can send a set
344 * timeout at one time, because we only have one copy of the data.
345 * The mutex is claimed when the set_timeout is sent and freed
346 * when both messages are free.
348 static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
349 static DEFINE_MUTEX(set_timeout_lock);
350 static DECLARE_COMPLETION(set_timeout_wait);
351 static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
353 if (atomic_dec_and_test(&set_timeout_tofree))
354 complete(&set_timeout_wait);
356 static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
358 if (atomic_dec_and_test(&set_timeout_tofree))
359 complete(&set_timeout_wait);
361 static struct ipmi_smi_msg set_timeout_smi_msg = {
362 .done = set_timeout_free_smi
364 static struct ipmi_recv_msg set_timeout_recv_msg = {
365 .done = set_timeout_free_recv
368 static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg,
369 struct ipmi_recv_msg *recv_msg,
370 int *send_heartbeat_now)
372 struct kernel_ipmi_msg msg;
373 unsigned char data[6];
375 struct ipmi_system_interface_addr addr;
379 /* These can be cleared as we are setting the timeout. */
380 pretimeout_since_last_heartbeat = 0;
383 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
385 if ((ipmi_version_major > 1)
386 || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
387 /* This is an IPMI 1.5-only feature. */
388 data[0] |= WDOG_DONT_STOP_ON_SET;
389 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
391 * In ipmi 1.0, setting the timer stops the watchdog, we
392 * need to start it back up again.
398 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
399 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
400 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
401 data[2] = pretimeout;
403 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
404 data[2] = 0; /* No pretimeout. */
407 WDOG_SET_TIMEOUT(data[4], data[5], timeout);
409 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
410 addr.channel = IPMI_BMC_CHANNEL;
414 msg.cmd = IPMI_WDOG_SET_TIMER;
416 msg.data_len = sizeof(data);
417 rv = ipmi_request_supply_msgs(watchdog_user,
418 (struct ipmi_addr *) &addr,
426 printk(KERN_WARNING PFX "set timeout error: %d\n",
430 if (send_heartbeat_now)
431 *send_heartbeat_now = hbnow;
436 static int ipmi_set_timeout(int do_heartbeat)
438 int send_heartbeat_now;
442 /* We can only send one of these at a time. */
443 mutex_lock(&set_timeout_lock);
445 atomic_set(&set_timeout_tofree, 2);
447 rv = i_ipmi_set_timeout(&set_timeout_smi_msg,
448 &set_timeout_recv_msg,
449 &send_heartbeat_now);
451 mutex_unlock(&set_timeout_lock);
455 wait_for_completion(&set_timeout_wait);
457 mutex_unlock(&set_timeout_lock);
459 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
460 || ((send_heartbeat_now)
461 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
462 rv = ipmi_heartbeat();
468 static atomic_t panic_done_count = ATOMIC_INIT(0);
470 static void panic_smi_free(struct ipmi_smi_msg *msg)
472 atomic_dec(&panic_done_count);
474 static void panic_recv_free(struct ipmi_recv_msg *msg)
476 atomic_dec(&panic_done_count);
479 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
480 .done = panic_smi_free
482 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
483 .done = panic_recv_free
486 static void panic_halt_ipmi_heartbeat(void)
488 struct kernel_ipmi_msg msg;
489 struct ipmi_system_interface_addr addr;
493 * Don't reset the timer if we have the timer turned off, that
494 * re-enables the watchdog.
496 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
499 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
500 addr.channel = IPMI_BMC_CHANNEL;
504 msg.cmd = IPMI_WDOG_RESET_TIMER;
507 rv = ipmi_request_supply_msgs(watchdog_user,
508 (struct ipmi_addr *) &addr,
512 &panic_halt_heartbeat_smi_msg,
513 &panic_halt_heartbeat_recv_msg,
516 atomic_add(2, &panic_done_count);
519 static struct ipmi_smi_msg panic_halt_smi_msg = {
520 .done = panic_smi_free
522 static struct ipmi_recv_msg panic_halt_recv_msg = {
523 .done = panic_recv_free
527 * Special call, doesn't claim any locks. This is only to be called
528 * at panic or halt time, in run-to-completion mode, when the caller
529 * is the only CPU and the only thing that will be going is these IPMI
532 static void panic_halt_ipmi_set_timeout(void)
534 int send_heartbeat_now;
537 /* Wait for the messages to be free. */
538 while (atomic_read(&panic_done_count) != 0)
539 ipmi_poll_interface(watchdog_user);
540 rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
541 &panic_halt_recv_msg,
542 &send_heartbeat_now);
544 atomic_add(2, &panic_done_count);
545 if (send_heartbeat_now)
546 panic_halt_ipmi_heartbeat();
548 printk(KERN_WARNING PFX
549 "Unable to extend the watchdog timeout.");
550 while (atomic_read(&panic_done_count) != 0)
551 ipmi_poll_interface(watchdog_user);
555 * We use a mutex to make sure that only one thing can send a
556 * heartbeat at one time, because we only have one copy of the data.
557 * The semaphore is claimed when the set_timeout is sent and freed
558 * when both messages are free.
560 static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
561 static DEFINE_MUTEX(heartbeat_lock);
562 static DECLARE_COMPLETION(heartbeat_wait);
563 static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
565 if (atomic_dec_and_test(&heartbeat_tofree))
566 complete(&heartbeat_wait);
568 static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
570 if (atomic_dec_and_test(&heartbeat_tofree))
571 complete(&heartbeat_wait);
573 static struct ipmi_smi_msg heartbeat_smi_msg = {
574 .done = heartbeat_free_smi
576 static struct ipmi_recv_msg heartbeat_recv_msg = {
577 .done = heartbeat_free_recv
580 static int ipmi_heartbeat(void)
582 struct kernel_ipmi_msg msg;
584 struct ipmi_system_interface_addr addr;
586 if (ipmi_ignore_heartbeat)
589 if (ipmi_start_timer_on_heartbeat) {
590 ipmi_start_timer_on_heartbeat = 0;
591 ipmi_watchdog_state = action_val;
592 return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
593 } else if (pretimeout_since_last_heartbeat) {
595 * A pretimeout occurred, make sure we set the timeout.
596 * We don't want to set the action, though, we want to
597 * leave that alone (thus it can't be combined with the
600 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
603 mutex_lock(&heartbeat_lock);
605 atomic_set(&heartbeat_tofree, 2);
608 * Don't reset the timer if we have the timer turned off, that
609 * re-enables the watchdog.
611 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
612 mutex_unlock(&heartbeat_lock);
616 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
617 addr.channel = IPMI_BMC_CHANNEL;
621 msg.cmd = IPMI_WDOG_RESET_TIMER;
624 rv = ipmi_request_supply_msgs(watchdog_user,
625 (struct ipmi_addr *) &addr,
633 mutex_unlock(&heartbeat_lock);
634 printk(KERN_WARNING PFX "heartbeat failure: %d\n",
639 /* Wait for the heartbeat to be sent. */
640 wait_for_completion(&heartbeat_wait);
642 if (heartbeat_recv_msg.msg.data[0] != 0) {
644 * Got an error in the heartbeat response. It was already
645 * reported in ipmi_wdog_msg_handler, but we should return
651 mutex_unlock(&heartbeat_lock);
656 static struct watchdog_info ident = {
657 .options = 0, /* WDIOF_SETTIMEOUT, */
658 .firmware_version = 1,
662 static int ipmi_ioctl(struct inode *inode, struct file *file,
663 unsigned int cmd, unsigned long arg)
665 void __user *argp = (void __user *)arg;
670 case WDIOC_GETSUPPORT:
671 i = copy_to_user(argp, &ident, sizeof(ident));
672 return i ? -EFAULT : 0;
674 case WDIOC_SETTIMEOUT:
675 i = copy_from_user(&val, argp, sizeof(int));
679 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
681 case WDIOC_GETTIMEOUT:
682 i = copy_to_user(argp, &timeout, sizeof(timeout));
687 case WDIOC_SET_PRETIMEOUT:
688 case WDIOC_SETPRETIMEOUT:
689 i = copy_from_user(&val, argp, sizeof(int));
693 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
695 case WDIOC_GET_PRETIMEOUT:
696 case WDIOC_GETPRETIMEOUT:
697 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
702 case WDIOC_KEEPALIVE:
703 return ipmi_heartbeat();
705 case WDIOC_SETOPTIONS:
706 i = copy_from_user(&val, argp, sizeof(int));
709 if (val & WDIOS_DISABLECARD) {
710 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
711 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
712 ipmi_start_timer_on_heartbeat = 0;
715 if (val & WDIOS_ENABLECARD) {
716 ipmi_watchdog_state = action_val;
717 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
721 case WDIOC_GETSTATUS:
723 i = copy_to_user(argp, &val, sizeof(val));
733 static ssize_t ipmi_write(struct file *file,
734 const char __user *buf,
744 /* In case it was set long ago */
747 for (i = 0; i != len; i++) {
750 if (get_user(c, buf + i))
756 rv = ipmi_heartbeat();
763 static ssize_t ipmi_read(struct file *file,
775 * Reading returns if the pretimeout has gone off, and it only does
776 * it once per pretimeout.
778 spin_lock(&ipmi_read_lock);
780 if (file->f_flags & O_NONBLOCK) {
785 init_waitqueue_entry(&wait, current);
786 add_wait_queue(&read_q, &wait);
787 while (!data_to_read) {
788 set_current_state(TASK_INTERRUPTIBLE);
789 spin_unlock(&ipmi_read_lock);
791 spin_lock(&ipmi_read_lock);
793 remove_wait_queue(&read_q, &wait);
795 if (signal_pending(current)) {
803 spin_unlock(&ipmi_read_lock);
806 if (copy_to_user(buf, &data_to_read, 1))
815 static int ipmi_open(struct inode *ino, struct file *filep)
817 switch (iminor(ino)) {
819 if (test_and_set_bit(0, &ipmi_wdog_open))
825 * Don't start the timer now, let it start on the
828 ipmi_start_timer_on_heartbeat = 1;
829 return nonseekable_open(ino, filep);
836 static unsigned int ipmi_poll(struct file *file, poll_table *wait)
838 unsigned int mask = 0;
840 poll_wait(file, &read_q, wait);
842 spin_lock(&ipmi_read_lock);
844 mask |= (POLLIN | POLLRDNORM);
845 spin_unlock(&ipmi_read_lock);
850 static int ipmi_fasync(int fd, struct file *file, int on)
854 result = fasync_helper(fd, file, on, &fasync_q);
859 static int ipmi_close(struct inode *ino, struct file *filep)
861 if (iminor(ino) == WATCHDOG_MINOR) {
862 if (expect_close == 42) {
863 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
864 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
867 "Unexpected close, not stopping watchdog!\n");
870 clear_bit(0, &ipmi_wdog_open);
878 static const struct file_operations ipmi_wdog_fops = {
879 .owner = THIS_MODULE,
885 .release = ipmi_close,
886 .fasync = ipmi_fasync,
889 static struct miscdevice ipmi_wdog_miscdev = {
890 .minor = WATCHDOG_MINOR,
892 .fops = &ipmi_wdog_fops
895 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
898 if (msg->msg.data[0] != 0) {
899 printk(KERN_ERR PFX "response: Error %x on cmd %x\n",
904 ipmi_free_recv_msg(msg);
907 static void ipmi_wdog_pretimeout_handler(void *handler_data)
909 if (preaction_val != WDOG_PRETIMEOUT_NONE) {
910 if (preop_val == WDOG_PREOP_PANIC) {
911 if (atomic_inc_and_test(&preop_panic_excl))
912 panic("Watchdog pre-timeout");
913 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
914 spin_lock(&ipmi_read_lock);
916 wake_up_interruptible(&read_q);
917 kill_fasync(&fasync_q, SIGIO, POLL_IN);
919 spin_unlock(&ipmi_read_lock);
924 * On some machines, the heartbeat will give an error and not
925 * work unless we re-enable the timer. So do so.
927 pretimeout_since_last_heartbeat = 1;
930 static struct ipmi_user_hndl ipmi_hndlrs = {
931 .ipmi_recv_hndl = ipmi_wdog_msg_handler,
932 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler
935 static void ipmi_register_watchdog(int ipmi_intf)
942 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
945 watchdog_ifnum = ipmi_intf;
947 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
949 printk(KERN_CRIT PFX "Unable to register with ipmi\n");
953 ipmi_get_version(watchdog_user,
955 &ipmi_version_minor);
957 rv = misc_register(&ipmi_wdog_miscdev);
959 ipmi_destroy_user(watchdog_user);
960 watchdog_user = NULL;
961 printk(KERN_CRIT PFX "Unable to register misc device\n");
965 if (nmi_handler_registered) {
966 int old_pretimeout = pretimeout;
967 int old_timeout = timeout;
968 int old_preop_val = preop_val;
971 * Set the pretimeout to go off in a second and give
972 * ourselves plenty of time to stop the timer.
974 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
975 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
981 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
983 printk(KERN_WARNING PFX "Error starting timer to"
984 " test NMI: 0x%x. The NMI pretimeout will"
985 " likely not work\n", rv);
992 if (testing_nmi != 2) {
993 printk(KERN_WARNING PFX "IPMI NMI didn't seem to"
994 " occur. The NMI pretimeout will"
995 " likely not work\n");
999 preop_val = old_preop_val;
1000 pretimeout = old_pretimeout;
1001 timeout = old_timeout;
1006 if ((start_now) && (rv == 0)) {
1007 /* Run from startup, so start the timer now. */
1008 start_now = 0; /* Disable this function after first startup. */
1009 ipmi_watchdog_state = action_val;
1010 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1011 printk(KERN_INFO PFX "Starting now!\n");
1013 /* Stop the timer now. */
1014 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1015 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1019 static void ipmi_unregister_watchdog(int ipmi_intf)
1026 if (watchdog_ifnum != ipmi_intf)
1029 /* Make sure no one can call us any more. */
1030 misc_deregister(&ipmi_wdog_miscdev);
1033 * Wait to make sure the message makes it out. The lower layer has
1034 * pointers to our buffers, we want to make sure they are done before
1035 * we release our memory.
1037 while (atomic_read(&set_timeout_tofree))
1038 schedule_timeout_uninterruptible(1);
1040 /* Disconnect from IPMI. */
1041 rv = ipmi_destroy_user(watchdog_user);
1043 printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
1046 watchdog_user = NULL;
1054 ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
1056 struct die_args *args = data;
1061 /* Hack, if it's a memory or I/O error, ignore it. */
1062 if (args->err & 0xc0)
1066 * If we get here, it's an NMI that's not a memory or I/O
1067 * error. We can't truly tell if it's from IPMI or not
1068 * without sending a message, and sending a message is almost
1069 * impossible because of locking.
1077 /* If we are not expecting a timeout, ignore it. */
1078 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1081 if (preaction_val != WDOG_PRETIMEOUT_NMI)
1085 * If no one else handled the NMI, we assume it was the IPMI
1088 if (preop_val == WDOG_PREOP_PANIC) {
1089 /* On some machines, the heartbeat will give
1090 an error and not work unless we re-enable
1091 the timer. So do so. */
1092 pretimeout_since_last_heartbeat = 1;
1093 if (atomic_inc_and_test(&preop_panic_excl))
1094 panic(PFX "pre-timeout");
1100 static struct notifier_block ipmi_nmi_handler = {
1101 .notifier_call = ipmi_nmi
1105 static int wdog_reboot_handler(struct notifier_block *this,
1109 static int reboot_event_handled;
1111 if ((watchdog_user) && (!reboot_event_handled)) {
1112 /* Make sure we only do this once. */
1113 reboot_event_handled = 1;
1115 if (code == SYS_POWER_OFF || code == SYS_HALT) {
1116 /* Disable the WDT if we are shutting down. */
1117 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1118 panic_halt_ipmi_set_timeout();
1119 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1120 /* Set a long timer to let the reboot happens, but
1121 reboot if it hangs, but only if the watchdog
1122 timer was already running. */
1125 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1126 panic_halt_ipmi_set_timeout();
1132 static struct notifier_block wdog_reboot_notifier = {
1133 .notifier_call = wdog_reboot_handler,
1138 static int wdog_panic_handler(struct notifier_block *this,
1139 unsigned long event,
1142 static int panic_event_handled;
1144 /* On a panic, if we have a panic timeout, make sure to extend
1145 the watchdog timer to a reasonable value to complete the
1146 panic, if the watchdog timer is running. Plus the
1147 pretimeout is meaningless at panic time. */
1148 if (watchdog_user && !panic_event_handled &&
1149 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1150 /* Make sure we do this only once. */
1151 panic_event_handled = 1;
1155 panic_halt_ipmi_set_timeout();
1161 static struct notifier_block wdog_panic_notifier = {
1162 .notifier_call = wdog_panic_handler,
1164 .priority = 150 /* priority: INT_MAX >= x >= 0 */
1168 static void ipmi_new_smi(int if_num, struct device *device)
1170 ipmi_register_watchdog(if_num);
1173 static void ipmi_smi_gone(int if_num)
1175 ipmi_unregister_watchdog(if_num);
1178 static struct ipmi_smi_watcher smi_watcher = {
1179 .owner = THIS_MODULE,
1180 .new_smi = ipmi_new_smi,
1181 .smi_gone = ipmi_smi_gone
1184 static int action_op(const char *inval, char *outval)
1187 strcpy(outval, action);
1192 if (strcmp(inval, "reset") == 0)
1193 action_val = WDOG_TIMEOUT_RESET;
1194 else if (strcmp(inval, "none") == 0)
1195 action_val = WDOG_TIMEOUT_NONE;
1196 else if (strcmp(inval, "power_cycle") == 0)
1197 action_val = WDOG_TIMEOUT_POWER_CYCLE;
1198 else if (strcmp(inval, "power_off") == 0)
1199 action_val = WDOG_TIMEOUT_POWER_DOWN;
1202 strcpy(action, inval);
1206 static int preaction_op(const char *inval, char *outval)
1209 strcpy(outval, preaction);
1214 if (strcmp(inval, "pre_none") == 0)
1215 preaction_val = WDOG_PRETIMEOUT_NONE;
1216 else if (strcmp(inval, "pre_smi") == 0)
1217 preaction_val = WDOG_PRETIMEOUT_SMI;
1219 else if (strcmp(inval, "pre_nmi") == 0)
1220 preaction_val = WDOG_PRETIMEOUT_NMI;
1222 else if (strcmp(inval, "pre_int") == 0)
1223 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1226 strcpy(preaction, inval);
1230 static int preop_op(const char *inval, char *outval)
1233 strcpy(outval, preop);
1238 if (strcmp(inval, "preop_none") == 0)
1239 preop_val = WDOG_PREOP_NONE;
1240 else if (strcmp(inval, "preop_panic") == 0)
1241 preop_val = WDOG_PREOP_PANIC;
1242 else if (strcmp(inval, "preop_give_data") == 0)
1243 preop_val = WDOG_PREOP_GIVE_DATA;
1246 strcpy(preop, inval);
1250 static void check_parms(void)
1256 if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1258 if (preop_val == WDOG_PREOP_GIVE_DATA) {
1259 printk(KERN_WARNING PFX "Pretimeout op is to give data"
1260 " but NMI pretimeout is enabled, setting"
1261 " pretimeout op to none\n");
1262 preop_op("preop_none", NULL);
1266 if (do_nmi && !nmi_handler_registered) {
1267 rv = register_die_notifier(&ipmi_nmi_handler);
1269 printk(KERN_WARNING PFX
1270 "Can't register nmi handler\n");
1273 nmi_handler_registered = 1;
1274 } else if (!do_nmi && nmi_handler_registered) {
1275 unregister_die_notifier(&ipmi_nmi_handler);
1276 nmi_handler_registered = 0;
1281 static int __init ipmi_wdog_init(void)
1285 if (action_op(action, NULL)) {
1286 action_op("reset", NULL);
1287 printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
1288 " reset\n", action);
1291 if (preaction_op(preaction, NULL)) {
1292 preaction_op("pre_none", NULL);
1293 printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
1294 " none\n", preaction);
1297 if (preop_op(preop, NULL)) {
1298 preop_op("preop_none", NULL);
1299 printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
1305 register_reboot_notifier(&wdog_reboot_notifier);
1306 atomic_notifier_chain_register(&panic_notifier_list,
1307 &wdog_panic_notifier);
1309 rv = ipmi_smi_watcher_register(&smi_watcher);
1312 if (nmi_handler_registered)
1313 unregister_die_notifier(&ipmi_nmi_handler);
1315 atomic_notifier_chain_unregister(&panic_notifier_list,
1316 &wdog_panic_notifier);
1317 unregister_reboot_notifier(&wdog_reboot_notifier);
1318 printk(KERN_WARNING PFX "can't register smi watcher\n");
1322 printk(KERN_INFO PFX "driver initialized\n");
1327 static void __exit ipmi_wdog_exit(void)
1329 ipmi_smi_watcher_unregister(&smi_watcher);
1330 ipmi_unregister_watchdog(watchdog_ifnum);
1333 if (nmi_handler_registered)
1334 unregister_die_notifier(&ipmi_nmi_handler);
1337 atomic_notifier_chain_unregister(&panic_notifier_list,
1338 &wdog_panic_notifier);
1339 unregister_reboot_notifier(&wdog_reboot_notifier);
1341 module_exit(ipmi_wdog_exit);
1342 module_init(ipmi_wdog_init);
1343 MODULE_LICENSE("GPL");
1344 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1345 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");