1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * ipmi_watchdog.c
4 *
5 * A watchdog timer based upon the IPMI interface.
6 *
7 * Author: MontaVista Software, Inc.
8 * Corey Minyard <minyard@mvista.com>
9 * source@mvista.com
10 *
11 * Copyright 2002 MontaVista Software Inc.
12 */
13
14 #define pr_fmt(fmt) "IPMI Watchdog: " fmt
15
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/ipmi.h>
19 #include <linux/ipmi_smi.h>
20 #include <linux/mutex.h>
21 #include <linux/watchdog.h>
22 #include <linux/miscdevice.h>
23 #include <linux/init.h>
24 #include <linux/completion.h>
25 #include <linux/kdebug.h>
26 #include <linux/rwsem.h>
27 #include <linux/errno.h>
28 #include <linux/uaccess.h>
29 #include <linux/notifier.h>
30 #include <linux/nmi.h>
31 #include <linux/reboot.h>
32 #include <linux/wait.h>
33 #include <linux/poll.h>
34 #include <linux/string.h>
35 #include <linux/ctype.h>
36 #include <linux/delay.h>
37 #include <linux/atomic.h>
38 #include <linux/sched/signal.h>
39
40 #ifdef CONFIG_X86
41 /*
42 * This is ugly, but I've determined that x86 is the only architecture
43 * that can reasonably support the IPMI NMI watchdog timeout at this
44 * time. If another architecture adds this capability somehow, it
45 * will have to be a somewhat different mechanism and I have no idea
46 * how it will work. So in the unlikely event that another
47 * architecture supports this, we can figure out a good generic
48 * mechanism for it at that time.
49 */
50 #include <asm/kdebug.h>
51 #include <asm/nmi.h>
52 #define HAVE_DIE_NMI
53 #endif
54
55 /*
56 * The IPMI command/response information for the watchdog timer.
57 */
58
59 /* values for byte 1 of the set command, byte 2 of the get response. */
60 #define WDOG_DONT_LOG (1 << 7)
61 #define WDOG_DONT_STOP_ON_SET (1 << 6)
62 #define WDOG_SET_TIMER_USE(byte, use) \
63 byte = ((byte) & 0xf8) | ((use) & 0x7)
64 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
65 #define WDOG_TIMER_USE_BIOS_FRB2 1
66 #define WDOG_TIMER_USE_BIOS_POST 2
67 #define WDOG_TIMER_USE_OS_LOAD 3
68 #define WDOG_TIMER_USE_SMS_OS 4
69 #define WDOG_TIMER_USE_OEM 5
70
71 /* values for byte 2 of the set command, byte 3 of the get response. */
72 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
73 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
74 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
75 #define WDOG_PRETIMEOUT_NONE 0
76 #define WDOG_PRETIMEOUT_SMI 1
77 #define WDOG_PRETIMEOUT_NMI 2
78 #define WDOG_PRETIMEOUT_MSG_INT 3
79
80 /* Operations that can be performed on a pretimout. */
81 #define WDOG_PREOP_NONE 0
82 #define WDOG_PREOP_PANIC 1
83 /* Cause data to be available to read. Doesn't work in NMI mode. */
84 #define WDOG_PREOP_GIVE_DATA 2
85
86 /* Actions to perform on a full timeout. */
87 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
88 byte = ((byte) & 0xf8) | ((use) & 0x7)
89 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
90 #define WDOG_TIMEOUT_NONE 0
91 #define WDOG_TIMEOUT_RESET 1
92 #define WDOG_TIMEOUT_POWER_DOWN 2
93 #define WDOG_TIMEOUT_POWER_CYCLE 3
94
95 /*
96 * Byte 3 of the get command, byte 4 of the get response is the
97 * pre-timeout in seconds.
98 */
99
100 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
101 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1)
102 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2)
103 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3)
104 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4)
105 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5)
106
107 /*
108 * Setting/getting the watchdog timer value. This is for bytes 5 and
109 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
110 * timeout time) and 8 and 9 (the current countdown value) of the
111 * response. The timeout value is given in seconds (in the command it
112 * is 100ms intervals).
113 */
114 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
115 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
116 #define WDOG_GET_TIMEOUT(byte1, byte2) \
117 (((byte1) | ((byte2) << 8)) / 10)
118
119 #define IPMI_WDOG_RESET_TIMER 0x22
120 #define IPMI_WDOG_SET_TIMER 0x24
121 #define IPMI_WDOG_GET_TIMER 0x25
122
123 #define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80
124
125 static DEFINE_MUTEX(ipmi_watchdog_mutex);
126 static bool nowayout = WATCHDOG_NOWAYOUT;
127
128 static struct ipmi_user *watchdog_user;
129 static int watchdog_ifnum;
130
131 /* Default the timeout to 10 seconds. */
132 static int timeout = 10;
133
134 /* The pre-timeout is disabled by default. */
135 static int pretimeout;
136
137 /* Default timeout to set on panic */
138 static int panic_wdt_timeout = 255;
139
140 /* Default action is to reset the board on a timeout. */
141 static unsigned char action_val = WDOG_TIMEOUT_RESET;
142
143 static char action[16] = "reset";
144
145 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
146
147 static char preaction[16] = "pre_none";
148
149 static unsigned char preop_val = WDOG_PREOP_NONE;
150
151 static char preop[16] = "preop_none";
152 static DEFINE_SPINLOCK(ipmi_read_lock);
153 static char data_to_read;
154 static DECLARE_WAIT_QUEUE_HEAD(read_q);
155 static struct fasync_struct *fasync_q;
156 static atomic_t pretimeout_since_last_heartbeat;
157 static char expect_close;
158
159 static int ifnum_to_use = -1;
160
161 /* Parameters to ipmi_set_timeout */
162 #define IPMI_SET_TIMEOUT_NO_HB 0
163 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1
164 #define IPMI_SET_TIMEOUT_FORCE_HB 2
165
166 static int ipmi_set_timeout(int do_heartbeat);
167 static void ipmi_register_watchdog(int ipmi_intf);
168 static void ipmi_unregister_watchdog(int ipmi_intf);
169
170 /*
171 * If true, the driver will start running as soon as it is configured
172 * and ready.
173 */
174 static int start_now;
175
set_param_timeout(const char * val,const struct kernel_param * kp)176 static int set_param_timeout(const char *val, const struct kernel_param *kp)
177 {
178 char *endp;
179 int l;
180 int rv = 0;
181
182 if (!val)
183 return -EINVAL;
184 l = simple_strtoul(val, &endp, 0);
185 if (endp == val)
186 return -EINVAL;
187
188 *((int *)kp->arg) = l;
189 if (watchdog_user)
190 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
191
192 return rv;
193 }
194
195 static const struct kernel_param_ops param_ops_timeout = {
196 .set = set_param_timeout,
197 .get = param_get_int,
198 };
199 #define param_check_timeout param_check_int
200
201 typedef int (*action_fn)(const char *intval, char *outval);
202
203 static int action_op(const char *inval, char *outval);
204 static int preaction_op(const char *inval, char *outval);
205 static int preop_op(const char *inval, char *outval);
206 static void check_parms(void);
207
set_param_str(const char * val,const struct kernel_param * kp)208 static int set_param_str(const char *val, const struct kernel_param *kp)
209 {
210 action_fn fn = (action_fn) kp->arg;
211 int rv = 0;
212 char valcp[16];
213 char *s;
214
215 strncpy(valcp, val, 15);
216 valcp[15] = '\0';
217
218 s = strstrip(valcp);
219
220 rv = fn(s, NULL);
221 if (rv)
222 goto out;
223
224 check_parms();
225 if (watchdog_user)
226 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
227
228 out:
229 return rv;
230 }
231
get_param_str(char * buffer,const struct kernel_param * kp)232 static int get_param_str(char *buffer, const struct kernel_param *kp)
233 {
234 action_fn fn = (action_fn) kp->arg;
235 int rv, len;
236
237 rv = fn(NULL, buffer);
238 if (rv)
239 return rv;
240
241 len = strlen(buffer);
242 buffer[len++] = '\n';
243 buffer[len] = 0;
244
245 return len;
246 }
247
248
set_param_wdog_ifnum(const char * val,const struct kernel_param * kp)249 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp)
250 {
251 int rv = param_set_int(val, kp);
252 if (rv)
253 return rv;
254 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
255 return 0;
256
257 ipmi_unregister_watchdog(watchdog_ifnum);
258 ipmi_register_watchdog(ifnum_to_use);
259 return 0;
260 }
261
262 static const struct kernel_param_ops param_ops_wdog_ifnum = {
263 .set = set_param_wdog_ifnum,
264 .get = param_get_int,
265 };
266
267 #define param_check_wdog_ifnum param_check_int
268
269 static const struct kernel_param_ops param_ops_str = {
270 .set = set_param_str,
271 .get = get_param_str,
272 };
273
274 module_param(ifnum_to_use, wdog_ifnum, 0644);
275 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
276 "timer. Setting to -1 defaults to the first registered "
277 "interface");
278
279 module_param(timeout, timeout, 0644);
280 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
281
282 module_param(pretimeout, timeout, 0644);
283 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
284
285 module_param(panic_wdt_timeout, timeout, 0644);
286 MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds.");
287
288 module_param_cb(action, ¶m_ops_str, action_op, 0644);
289 MODULE_PARM_DESC(action, "Timeout action. One of: "
290 "reset, none, power_cycle, power_off.");
291
292 module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644);
293 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "
294 "pre_none, pre_smi, pre_nmi, pre_int.");
295
296 module_param_cb(preop, ¶m_ops_str, preop_op, 0644);
297 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "
298 "preop_none, preop_panic, preop_give_data.");
299
300 module_param(start_now, int, 0444);
301 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
302 "soon as the driver is loaded.");
303
304 module_param(nowayout, bool, 0644);
305 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
306 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
307
308 /* Default state of the timer. */
309 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
310
311 /* Is someone using the watchdog? Only one user is allowed. */
312 static unsigned long ipmi_wdog_open;
313
314 /*
315 * If set to 1, the heartbeat command will set the state to reset and
316 * start the timer. The timer doesn't normally run when the driver is
317 * first opened until the heartbeat is set the first time, this
318 * variable is used to accomplish this.
319 */
320 static int ipmi_start_timer_on_heartbeat;
321
322 /* IPMI version of the BMC. */
323 static unsigned char ipmi_version_major;
324 static unsigned char ipmi_version_minor;
325
326 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
327 static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
328
329 #ifdef HAVE_DIE_NMI
330 static int testing_nmi;
331 static int nmi_handler_registered;
332 #endif
333
334 static int __ipmi_heartbeat(void);
335
336 /*
337 * We use a mutex to make sure that only one thing can send a set a
338 * message at one time. The mutex is claimed when a message is sent
339 * and freed when both the send and receive messages are free.
340 */
341 static atomic_t msg_tofree = ATOMIC_INIT(0);
342 static DECLARE_COMPLETION(msg_wait);
msg_free_smi(struct ipmi_smi_msg * msg)343 static void msg_free_smi(struct ipmi_smi_msg *msg)
344 {
345 if (atomic_dec_and_test(&msg_tofree)) {
346 if (!oops_in_progress)
347 complete(&msg_wait);
348 }
349 }
msg_free_recv(struct ipmi_recv_msg * msg)350 static void msg_free_recv(struct ipmi_recv_msg *msg)
351 {
352 if (atomic_dec_and_test(&msg_tofree)) {
353 if (!oops_in_progress)
354 complete(&msg_wait);
355 }
356 }
357 static struct ipmi_smi_msg smi_msg = {
358 .done = msg_free_smi
359 };
360 static struct ipmi_recv_msg recv_msg = {
361 .done = msg_free_recv
362 };
363
__ipmi_set_timeout(struct ipmi_smi_msg * smi_msg,struct ipmi_recv_msg * recv_msg,int * send_heartbeat_now)364 static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg,
365 struct ipmi_recv_msg *recv_msg,
366 int *send_heartbeat_now)
367 {
368 struct kernel_ipmi_msg msg;
369 unsigned char data[6];
370 int rv;
371 struct ipmi_system_interface_addr addr;
372 int hbnow = 0;
373
374
375 data[0] = 0;
376 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
377
378 if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
379 if ((ipmi_version_major > 1) ||
380 ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
381 /* This is an IPMI 1.5-only feature. */
382 data[0] |= WDOG_DONT_STOP_ON_SET;
383 } else {
384 /*
385 * In ipmi 1.0, setting the timer stops the watchdog, we
386 * need to start it back up again.
387 */
388 hbnow = 1;
389 }
390 }
391
392 data[1] = 0;
393 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
394 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
395 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
396 data[2] = pretimeout;
397 } else {
398 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
399 data[2] = 0; /* No pretimeout. */
400 }
401 data[3] = 0;
402 WDOG_SET_TIMEOUT(data[4], data[5], timeout);
403
404 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
405 addr.channel = IPMI_BMC_CHANNEL;
406 addr.lun = 0;
407
408 msg.netfn = 0x06;
409 msg.cmd = IPMI_WDOG_SET_TIMER;
410 msg.data = data;
411 msg.data_len = sizeof(data);
412 rv = ipmi_request_supply_msgs(watchdog_user,
413 (struct ipmi_addr *) &addr,
414 0,
415 &msg,
416 NULL,
417 smi_msg,
418 recv_msg,
419 1);
420 if (rv)
421 pr_warn("set timeout error: %d\n", rv);
422 else if (send_heartbeat_now)
423 *send_heartbeat_now = hbnow;
424
425 return rv;
426 }
427
_ipmi_set_timeout(int do_heartbeat)428 static int _ipmi_set_timeout(int do_heartbeat)
429 {
430 int send_heartbeat_now;
431 int rv;
432
433 if (!watchdog_user)
434 return -ENODEV;
435
436 atomic_set(&msg_tofree, 2);
437
438 rv = __ipmi_set_timeout(&smi_msg,
439 &recv_msg,
440 &send_heartbeat_now);
441 if (rv) {
442 atomic_set(&msg_tofree, 0);
443 return rv;
444 }
445
446 wait_for_completion(&msg_wait);
447
448 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
449 || ((send_heartbeat_now)
450 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
451 rv = __ipmi_heartbeat();
452
453 return rv;
454 }
455
ipmi_set_timeout(int do_heartbeat)456 static int ipmi_set_timeout(int do_heartbeat)
457 {
458 int rv;
459
460 mutex_lock(&ipmi_watchdog_mutex);
461 rv = _ipmi_set_timeout(do_heartbeat);
462 mutex_unlock(&ipmi_watchdog_mutex);
463
464 return rv;
465 }
466
467 static atomic_t panic_done_count = ATOMIC_INIT(0);
468
panic_smi_free(struct ipmi_smi_msg * msg)469 static void panic_smi_free(struct ipmi_smi_msg *msg)
470 {
471 atomic_dec(&panic_done_count);
472 }
panic_recv_free(struct ipmi_recv_msg * msg)473 static void panic_recv_free(struct ipmi_recv_msg *msg)
474 {
475 atomic_dec(&panic_done_count);
476 }
477
478 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
479 .done = panic_smi_free
480 };
481 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
482 .done = panic_recv_free
483 };
484
panic_halt_ipmi_heartbeat(void)485 static void panic_halt_ipmi_heartbeat(void)
486 {
487 struct kernel_ipmi_msg msg;
488 struct ipmi_system_interface_addr addr;
489 int rv;
490
491 /*
492 * Don't reset the timer if we have the timer turned off, that
493 * re-enables the watchdog.
494 */
495 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
496 return;
497
498 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
499 addr.channel = IPMI_BMC_CHANNEL;
500 addr.lun = 0;
501
502 msg.netfn = 0x06;
503 msg.cmd = IPMI_WDOG_RESET_TIMER;
504 msg.data = NULL;
505 msg.data_len = 0;
506 atomic_add(2, &panic_done_count);
507 rv = ipmi_request_supply_msgs(watchdog_user,
508 (struct ipmi_addr *) &addr,
509 0,
510 &msg,
511 NULL,
512 &panic_halt_heartbeat_smi_msg,
513 &panic_halt_heartbeat_recv_msg,
514 1);
515 if (rv)
516 atomic_sub(2, &panic_done_count);
517 }
518
519 static struct ipmi_smi_msg panic_halt_smi_msg = {
520 .done = panic_smi_free
521 };
522 static struct ipmi_recv_msg panic_halt_recv_msg = {
523 .done = panic_recv_free
524 };
525
526 /*
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
530 * calls.
531 */
panic_halt_ipmi_set_timeout(void)532 static void panic_halt_ipmi_set_timeout(void)
533 {
534 int send_heartbeat_now;
535 int rv;
536
537 /* Wait for the messages to be free. */
538 while (atomic_read(&panic_done_count) != 0)
539 ipmi_poll_interface(watchdog_user);
540 atomic_add(2, &panic_done_count);
541 rv = __ipmi_set_timeout(&panic_halt_smi_msg,
542 &panic_halt_recv_msg,
543 &send_heartbeat_now);
544 if (rv) {
545 atomic_sub(2, &panic_done_count);
546 pr_warn("Unable to extend the watchdog timeout\n");
547 } else {
548 if (send_heartbeat_now)
549 panic_halt_ipmi_heartbeat();
550 }
551 while (atomic_read(&panic_done_count) != 0)
552 ipmi_poll_interface(watchdog_user);
553 }
554
__ipmi_heartbeat(void)555 static int __ipmi_heartbeat(void)
556 {
557 struct kernel_ipmi_msg msg;
558 int rv;
559 struct ipmi_system_interface_addr addr;
560 int timeout_retries = 0;
561
562 restart:
563 /*
564 * Don't reset the timer if we have the timer turned off, that
565 * re-enables the watchdog.
566 */
567 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
568 return 0;
569
570 atomic_set(&msg_tofree, 2);
571
572 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
573 addr.channel = IPMI_BMC_CHANNEL;
574 addr.lun = 0;
575
576 msg.netfn = 0x06;
577 msg.cmd = IPMI_WDOG_RESET_TIMER;
578 msg.data = NULL;
579 msg.data_len = 0;
580 rv = ipmi_request_supply_msgs(watchdog_user,
581 (struct ipmi_addr *) &addr,
582 0,
583 &msg,
584 NULL,
585 &smi_msg,
586 &recv_msg,
587 1);
588 if (rv) {
589 atomic_set(&msg_tofree, 0);
590 pr_warn("heartbeat send failure: %d\n", rv);
591 return rv;
592 }
593
594 /* Wait for the heartbeat to be sent. */
595 wait_for_completion(&msg_wait);
596
597 if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) {
598 timeout_retries++;
599 if (timeout_retries > 3) {
600 pr_err("Unable to restore the IPMI watchdog's settings, giving up\n");
601 rv = -EIO;
602 goto out;
603 }
604
605 /*
606 * The timer was not initialized, that means the BMC was
607 * probably reset and lost the watchdog information. Attempt
608 * to restore the timer's info. Note that we still hold
609 * the heartbeat lock, to keep a heartbeat from happening
610 * in this process, so must say no heartbeat to avoid a
611 * deadlock on this mutex
612 */
613 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
614 if (rv) {
615 pr_err("Unable to send the command to set the watchdog's settings, giving up\n");
616 goto out;
617 }
618
619 /* Might need a heartbeat send, go ahead and do it. */
620 goto restart;
621 } else if (recv_msg.msg.data[0] != 0) {
622 /*
623 * Got an error in the heartbeat response. It was already
624 * reported in ipmi_wdog_msg_handler, but we should return
625 * an error here.
626 */
627 rv = -EINVAL;
628 }
629
630 out:
631 return rv;
632 }
633
_ipmi_heartbeat(void)634 static int _ipmi_heartbeat(void)
635 {
636 int rv;
637
638 if (!watchdog_user)
639 return -ENODEV;
640
641 if (ipmi_start_timer_on_heartbeat) {
642 ipmi_start_timer_on_heartbeat = 0;
643 ipmi_watchdog_state = action_val;
644 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
645 } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) {
646 /*
647 * A pretimeout occurred, make sure we set the timeout.
648 * We don't want to set the action, though, we want to
649 * leave that alone (thus it can't be combined with the
650 * above operation.
651 */
652 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
653 } else {
654 rv = __ipmi_heartbeat();
655 }
656
657 return rv;
658 }
659
ipmi_heartbeat(void)660 static int ipmi_heartbeat(void)
661 {
662 int rv;
663
664 mutex_lock(&ipmi_watchdog_mutex);
665 rv = _ipmi_heartbeat();
666 mutex_unlock(&ipmi_watchdog_mutex);
667
668 return rv;
669 }
670
671 static struct watchdog_info ident = {
672 .options = 0, /* WDIOF_SETTIMEOUT, */
673 .firmware_version = 1,
674 .identity = "IPMI"
675 };
676
ipmi_ioctl(struct file * file,unsigned int cmd,unsigned long arg)677 static int ipmi_ioctl(struct file *file,
678 unsigned int cmd, unsigned long arg)
679 {
680 void __user *argp = (void __user *)arg;
681 int i;
682 int val;
683
684 switch (cmd) {
685 case WDIOC_GETSUPPORT:
686 i = copy_to_user(argp, &ident, sizeof(ident));
687 return i ? -EFAULT : 0;
688
689 case WDIOC_SETTIMEOUT:
690 i = copy_from_user(&val, argp, sizeof(int));
691 if (i)
692 return -EFAULT;
693 timeout = val;
694 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
695
696 case WDIOC_GETTIMEOUT:
697 i = copy_to_user(argp, &timeout, sizeof(timeout));
698 if (i)
699 return -EFAULT;
700 return 0;
701
702 case WDIOC_SETPRETIMEOUT:
703 i = copy_from_user(&val, argp, sizeof(int));
704 if (i)
705 return -EFAULT;
706 pretimeout = val;
707 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
708
709 case WDIOC_GETPRETIMEOUT:
710 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
711 if (i)
712 return -EFAULT;
713 return 0;
714
715 case WDIOC_KEEPALIVE:
716 return _ipmi_heartbeat();
717
718 case WDIOC_SETOPTIONS:
719 i = copy_from_user(&val, argp, sizeof(int));
720 if (i)
721 return -EFAULT;
722 if (val & WDIOS_DISABLECARD) {
723 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
724 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
725 ipmi_start_timer_on_heartbeat = 0;
726 }
727
728 if (val & WDIOS_ENABLECARD) {
729 ipmi_watchdog_state = action_val;
730 _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
731 }
732 return 0;
733
734 case WDIOC_GETSTATUS:
735 val = 0;
736 i = copy_to_user(argp, &val, sizeof(val));
737 if (i)
738 return -EFAULT;
739 return 0;
740
741 default:
742 return -ENOIOCTLCMD;
743 }
744 }
745
ipmi_unlocked_ioctl(struct file * file,unsigned int cmd,unsigned long arg)746 static long ipmi_unlocked_ioctl(struct file *file,
747 unsigned int cmd,
748 unsigned long arg)
749 {
750 int ret;
751
752 mutex_lock(&ipmi_watchdog_mutex);
753 ret = ipmi_ioctl(file, cmd, arg);
754 mutex_unlock(&ipmi_watchdog_mutex);
755
756 return ret;
757 }
758
ipmi_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)759 static ssize_t ipmi_write(struct file *file,
760 const char __user *buf,
761 size_t len,
762 loff_t *ppos)
763 {
764 int rv;
765
766 if (len) {
767 if (!nowayout) {
768 size_t i;
769
770 /* In case it was set long ago */
771 expect_close = 0;
772
773 for (i = 0; i != len; i++) {
774 char c;
775
776 if (get_user(c, buf + i))
777 return -EFAULT;
778 if (c == 'V')
779 expect_close = 42;
780 }
781 }
782 rv = ipmi_heartbeat();
783 if (rv)
784 return rv;
785 }
786 return len;
787 }
788
ipmi_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)789 static ssize_t ipmi_read(struct file *file,
790 char __user *buf,
791 size_t count,
792 loff_t *ppos)
793 {
794 int rv = 0;
795 wait_queue_entry_t wait;
796
797 if (count <= 0)
798 return 0;
799
800 /*
801 * Reading returns if the pretimeout has gone off, and it only does
802 * it once per pretimeout.
803 */
804 spin_lock_irq(&ipmi_read_lock);
805 if (!data_to_read) {
806 if (file->f_flags & O_NONBLOCK) {
807 rv = -EAGAIN;
808 goto out;
809 }
810
811 init_waitqueue_entry(&wait, current);
812 add_wait_queue(&read_q, &wait);
813 while (!data_to_read) {
814 set_current_state(TASK_INTERRUPTIBLE);
815 spin_unlock_irq(&ipmi_read_lock);
816 schedule();
817 spin_lock_irq(&ipmi_read_lock);
818 }
819 remove_wait_queue(&read_q, &wait);
820
821 if (signal_pending(current)) {
822 rv = -ERESTARTSYS;
823 goto out;
824 }
825 }
826 data_to_read = 0;
827
828 out:
829 spin_unlock_irq(&ipmi_read_lock);
830
831 if (rv == 0) {
832 if (copy_to_user(buf, &data_to_read, 1))
833 rv = -EFAULT;
834 else
835 rv = 1;
836 }
837
838 return rv;
839 }
840
ipmi_open(struct inode * ino,struct file * filep)841 static int ipmi_open(struct inode *ino, struct file *filep)
842 {
843 switch (iminor(ino)) {
844 case WATCHDOG_MINOR:
845 if (test_and_set_bit(0, &ipmi_wdog_open))
846 return -EBUSY;
847
848
849 /*
850 * Don't start the timer now, let it start on the
851 * first heartbeat.
852 */
853 ipmi_start_timer_on_heartbeat = 1;
854 return stream_open(ino, filep);
855
856 default:
857 return (-ENODEV);
858 }
859 }
860
ipmi_poll(struct file * file,poll_table * wait)861 static __poll_t ipmi_poll(struct file *file, poll_table *wait)
862 {
863 __poll_t mask = 0;
864
865 poll_wait(file, &read_q, wait);
866
867 spin_lock_irq(&ipmi_read_lock);
868 if (data_to_read)
869 mask |= (EPOLLIN | EPOLLRDNORM);
870 spin_unlock_irq(&ipmi_read_lock);
871
872 return mask;
873 }
874
ipmi_fasync(int fd,struct file * file,int on)875 static int ipmi_fasync(int fd, struct file *file, int on)
876 {
877 int result;
878
879 result = fasync_helper(fd, file, on, &fasync_q);
880
881 return (result);
882 }
883
ipmi_close(struct inode * ino,struct file * filep)884 static int ipmi_close(struct inode *ino, struct file *filep)
885 {
886 if (iminor(ino) == WATCHDOG_MINOR) {
887 if (expect_close == 42) {
888 mutex_lock(&ipmi_watchdog_mutex);
889 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
890 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
891 mutex_unlock(&ipmi_watchdog_mutex);
892 } else {
893 pr_crit("Unexpected close, not stopping watchdog!\n");
894 ipmi_heartbeat();
895 }
896 clear_bit(0, &ipmi_wdog_open);
897 }
898
899 expect_close = 0;
900
901 return 0;
902 }
903
904 static const struct file_operations ipmi_wdog_fops = {
905 .owner = THIS_MODULE,
906 .read = ipmi_read,
907 .poll = ipmi_poll,
908 .write = ipmi_write,
909 .unlocked_ioctl = ipmi_unlocked_ioctl,
910 .compat_ioctl = compat_ptr_ioctl,
911 .open = ipmi_open,
912 .release = ipmi_close,
913 .fasync = ipmi_fasync,
914 .llseek = no_llseek,
915 };
916
917 static struct miscdevice ipmi_wdog_miscdev = {
918 .minor = WATCHDOG_MINOR,
919 .name = "watchdog",
920 .fops = &ipmi_wdog_fops
921 };
922
ipmi_wdog_msg_handler(struct ipmi_recv_msg * msg,void * handler_data)923 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
924 void *handler_data)
925 {
926 if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
927 msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
928 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");
929 else if (msg->msg.data[0] != 0)
930 pr_err("response: Error %x on cmd %x\n",
931 msg->msg.data[0],
932 msg->msg.cmd);
933
934 ipmi_free_recv_msg(msg);
935 }
936
ipmi_wdog_pretimeout_handler(void * handler_data)937 static void ipmi_wdog_pretimeout_handler(void *handler_data)
938 {
939 if (preaction_val != WDOG_PRETIMEOUT_NONE) {
940 if (preop_val == WDOG_PREOP_PANIC) {
941 if (atomic_inc_and_test(&preop_panic_excl))
942 panic("Watchdog pre-timeout");
943 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
944 unsigned long flags;
945
946 spin_lock_irqsave(&ipmi_read_lock, flags);
947 data_to_read = 1;
948 wake_up_interruptible(&read_q);
949 kill_fasync(&fasync_q, SIGIO, POLL_IN);
950 spin_unlock_irqrestore(&ipmi_read_lock, flags);
951 }
952 }
953
954 /*
955 * On some machines, the heartbeat will give an error and not
956 * work unless we re-enable the timer. So do so.
957 */
958 atomic_set(&pretimeout_since_last_heartbeat, 1);
959 }
960
ipmi_wdog_panic_handler(void * user_data)961 static void ipmi_wdog_panic_handler(void *user_data)
962 {
963 static int panic_event_handled;
964
965 /*
966 * On a panic, if we have a panic timeout, make sure to extend
967 * the watchdog timer to a reasonable value to complete the
968 * panic, if the watchdog timer is running. Plus the
969 * pretimeout is meaningless at panic time.
970 */
971 if (watchdog_user && !panic_event_handled &&
972 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
973 /* Make sure we do this only once. */
974 panic_event_handled = 1;
975
976 timeout = panic_wdt_timeout;
977 pretimeout = 0;
978 panic_halt_ipmi_set_timeout();
979 }
980 }
981
982 static const struct ipmi_user_hndl ipmi_hndlrs = {
983 .ipmi_recv_hndl = ipmi_wdog_msg_handler,
984 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler,
985 .ipmi_panic_handler = ipmi_wdog_panic_handler
986 };
987
ipmi_register_watchdog(int ipmi_intf)988 static void ipmi_register_watchdog(int ipmi_intf)
989 {
990 int rv = -EBUSY;
991
992 if (watchdog_user)
993 goto out;
994
995 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
996 goto out;
997
998 watchdog_ifnum = ipmi_intf;
999
1000 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
1001 if (rv < 0) {
1002 pr_crit("Unable to register with ipmi\n");
1003 goto out;
1004 }
1005
1006 rv = ipmi_get_version(watchdog_user,
1007 &ipmi_version_major,
1008 &ipmi_version_minor);
1009 if (rv) {
1010 pr_warn("Unable to get IPMI version, assuming 1.0\n");
1011 ipmi_version_major = 1;
1012 ipmi_version_minor = 0;
1013 }
1014
1015 rv = misc_register(&ipmi_wdog_miscdev);
1016 if (rv < 0) {
1017 ipmi_destroy_user(watchdog_user);
1018 watchdog_user = NULL;
1019 pr_crit("Unable to register misc device\n");
1020 }
1021
1022 #ifdef HAVE_DIE_NMI
1023 if (nmi_handler_registered) {
1024 int old_pretimeout = pretimeout;
1025 int old_timeout = timeout;
1026 int old_preop_val = preop_val;
1027
1028 /*
1029 * Set the pretimeout to go off in a second and give
1030 * ourselves plenty of time to stop the timer.
1031 */
1032 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1033 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
1034 pretimeout = 99;
1035 timeout = 100;
1036
1037 testing_nmi = 1;
1038
1039 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1040 if (rv) {
1041 pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n",
1042 rv);
1043 rv = 0;
1044 goto out_restore;
1045 }
1046
1047 msleep(1500);
1048
1049 if (testing_nmi != 2) {
1050 pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n");
1051 }
1052 out_restore:
1053 testing_nmi = 0;
1054 preop_val = old_preop_val;
1055 pretimeout = old_pretimeout;
1056 timeout = old_timeout;
1057 }
1058 #endif
1059
1060 out:
1061 if ((start_now) && (rv == 0)) {
1062 /* Run from startup, so start the timer now. */
1063 start_now = 0; /* Disable this function after first startup. */
1064 ipmi_watchdog_state = action_val;
1065 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1066 pr_info("Starting now!\n");
1067 } else {
1068 /* Stop the timer now. */
1069 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1070 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1071 }
1072 }
1073
ipmi_unregister_watchdog(int ipmi_intf)1074 static void ipmi_unregister_watchdog(int ipmi_intf)
1075 {
1076 int rv;
1077 struct ipmi_user *loc_user = watchdog_user;
1078
1079 if (!loc_user)
1080 return;
1081
1082 if (watchdog_ifnum != ipmi_intf)
1083 return;
1084
1085 /* Make sure no one can call us any more. */
1086 misc_deregister(&ipmi_wdog_miscdev);
1087
1088 watchdog_user = NULL;
1089
1090 /*
1091 * Wait to make sure the message makes it out. The lower layer has
1092 * pointers to our buffers, we want to make sure they are done before
1093 * we release our memory.
1094 */
1095 while (atomic_read(&msg_tofree))
1096 msg_free_smi(NULL);
1097
1098 mutex_lock(&ipmi_watchdog_mutex);
1099
1100 /* Disconnect from IPMI. */
1101 rv = ipmi_destroy_user(loc_user);
1102 if (rv)
1103 pr_warn("error unlinking from IPMI: %d\n", rv);
1104
1105 /* If it comes back, restart it properly. */
1106 ipmi_start_timer_on_heartbeat = 1;
1107
1108 mutex_unlock(&ipmi_watchdog_mutex);
1109 }
1110
1111 #ifdef HAVE_DIE_NMI
1112 static int
ipmi_nmi(unsigned int val,struct pt_regs * regs)1113 ipmi_nmi(unsigned int val, struct pt_regs *regs)
1114 {
1115 /*
1116 * If we get here, it's an NMI that's not a memory or I/O
1117 * error. We can't truly tell if it's from IPMI or not
1118 * without sending a message, and sending a message is almost
1119 * impossible because of locking.
1120 */
1121
1122 if (testing_nmi) {
1123 testing_nmi = 2;
1124 return NMI_HANDLED;
1125 }
1126
1127 /* If we are not expecting a timeout, ignore it. */
1128 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1129 return NMI_DONE;
1130
1131 if (preaction_val != WDOG_PRETIMEOUT_NMI)
1132 return NMI_DONE;
1133
1134 /*
1135 * If no one else handled the NMI, we assume it was the IPMI
1136 * watchdog.
1137 */
1138 if (preop_val == WDOG_PREOP_PANIC) {
1139 /* On some machines, the heartbeat will give
1140 an error and not work unless we re-enable
1141 the timer. So do so. */
1142 atomic_set(&pretimeout_since_last_heartbeat, 1);
1143 if (atomic_inc_and_test(&preop_panic_excl))
1144 nmi_panic(regs, "pre-timeout");
1145 }
1146
1147 return NMI_HANDLED;
1148 }
1149 #endif
1150
wdog_reboot_handler(struct notifier_block * this,unsigned long code,void * unused)1151 static int wdog_reboot_handler(struct notifier_block *this,
1152 unsigned long code,
1153 void *unused)
1154 {
1155 static int reboot_event_handled;
1156
1157 if ((watchdog_user) && (!reboot_event_handled)) {
1158 /* Make sure we only do this once. */
1159 reboot_event_handled = 1;
1160
1161 if (code == SYS_POWER_OFF || code == SYS_HALT) {
1162 /* Disable the WDT if we are shutting down. */
1163 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1164 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1165 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1166 /* Set a long timer to let the reboot happen or
1167 reset if it hangs, but only if the watchdog
1168 timer was already running. */
1169 if (timeout < 120)
1170 timeout = 120;
1171 pretimeout = 0;
1172 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1173 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1174 }
1175 }
1176 return NOTIFY_OK;
1177 }
1178
1179 static struct notifier_block wdog_reboot_notifier = {
1180 .notifier_call = wdog_reboot_handler,
1181 .next = NULL,
1182 .priority = 0
1183 };
1184
ipmi_new_smi(int if_num,struct device * device)1185 static void ipmi_new_smi(int if_num, struct device *device)
1186 {
1187 ipmi_register_watchdog(if_num);
1188 }
1189
ipmi_smi_gone(int if_num)1190 static void ipmi_smi_gone(int if_num)
1191 {
1192 ipmi_unregister_watchdog(if_num);
1193 }
1194
1195 static struct ipmi_smi_watcher smi_watcher = {
1196 .owner = THIS_MODULE,
1197 .new_smi = ipmi_new_smi,
1198 .smi_gone = ipmi_smi_gone
1199 };
1200
action_op(const char * inval,char * outval)1201 static int action_op(const char *inval, char *outval)
1202 {
1203 if (outval)
1204 strcpy(outval, action);
1205
1206 if (!inval)
1207 return 0;
1208
1209 if (strcmp(inval, "reset") == 0)
1210 action_val = WDOG_TIMEOUT_RESET;
1211 else if (strcmp(inval, "none") == 0)
1212 action_val = WDOG_TIMEOUT_NONE;
1213 else if (strcmp(inval, "power_cycle") == 0)
1214 action_val = WDOG_TIMEOUT_POWER_CYCLE;
1215 else if (strcmp(inval, "power_off") == 0)
1216 action_val = WDOG_TIMEOUT_POWER_DOWN;
1217 else
1218 return -EINVAL;
1219 strcpy(action, inval);
1220 return 0;
1221 }
1222
preaction_op(const char * inval,char * outval)1223 static int preaction_op(const char *inval, char *outval)
1224 {
1225 if (outval)
1226 strcpy(outval, preaction);
1227
1228 if (!inval)
1229 return 0;
1230
1231 if (strcmp(inval, "pre_none") == 0)
1232 preaction_val = WDOG_PRETIMEOUT_NONE;
1233 else if (strcmp(inval, "pre_smi") == 0)
1234 preaction_val = WDOG_PRETIMEOUT_SMI;
1235 #ifdef HAVE_DIE_NMI
1236 else if (strcmp(inval, "pre_nmi") == 0)
1237 preaction_val = WDOG_PRETIMEOUT_NMI;
1238 #endif
1239 else if (strcmp(inval, "pre_int") == 0)
1240 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1241 else
1242 return -EINVAL;
1243 strcpy(preaction, inval);
1244 return 0;
1245 }
1246
preop_op(const char * inval,char * outval)1247 static int preop_op(const char *inval, char *outval)
1248 {
1249 if (outval)
1250 strcpy(outval, preop);
1251
1252 if (!inval)
1253 return 0;
1254
1255 if (strcmp(inval, "preop_none") == 0)
1256 preop_val = WDOG_PREOP_NONE;
1257 else if (strcmp(inval, "preop_panic") == 0)
1258 preop_val = WDOG_PREOP_PANIC;
1259 else if (strcmp(inval, "preop_give_data") == 0)
1260 preop_val = WDOG_PREOP_GIVE_DATA;
1261 else
1262 return -EINVAL;
1263 strcpy(preop, inval);
1264 return 0;
1265 }
1266
check_parms(void)1267 static void check_parms(void)
1268 {
1269 #ifdef HAVE_DIE_NMI
1270 int do_nmi = 0;
1271 int rv;
1272
1273 if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1274 do_nmi = 1;
1275 if (preop_val == WDOG_PREOP_GIVE_DATA) {
1276 pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n");
1277 preop_op("preop_none", NULL);
1278 do_nmi = 0;
1279 }
1280 }
1281 if (do_nmi && !nmi_handler_registered) {
1282 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0,
1283 "ipmi");
1284 if (rv) {
1285 pr_warn("Can't register nmi handler\n");
1286 return;
1287 } else
1288 nmi_handler_registered = 1;
1289 } else if (!do_nmi && nmi_handler_registered) {
1290 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1291 nmi_handler_registered = 0;
1292 }
1293 #endif
1294 }
1295
ipmi_wdog_init(void)1296 static int __init ipmi_wdog_init(void)
1297 {
1298 int rv;
1299
1300 if (action_op(action, NULL)) {
1301 action_op("reset", NULL);
1302 pr_info("Unknown action '%s', defaulting to reset\n", action);
1303 }
1304
1305 if (preaction_op(preaction, NULL)) {
1306 preaction_op("pre_none", NULL);
1307 pr_info("Unknown preaction '%s', defaulting to none\n",
1308 preaction);
1309 }
1310
1311 if (preop_op(preop, NULL)) {
1312 preop_op("preop_none", NULL);
1313 pr_info("Unknown preop '%s', defaulting to none\n", preop);
1314 }
1315
1316 check_parms();
1317
1318 register_reboot_notifier(&wdog_reboot_notifier);
1319
1320 rv = ipmi_smi_watcher_register(&smi_watcher);
1321 if (rv) {
1322 #ifdef HAVE_DIE_NMI
1323 if (nmi_handler_registered)
1324 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1325 #endif
1326 unregister_reboot_notifier(&wdog_reboot_notifier);
1327 pr_warn("can't register smi watcher\n");
1328 return rv;
1329 }
1330
1331 pr_info("driver initialized\n");
1332
1333 return 0;
1334 }
1335
ipmi_wdog_exit(void)1336 static void __exit ipmi_wdog_exit(void)
1337 {
1338 ipmi_smi_watcher_unregister(&smi_watcher);
1339 ipmi_unregister_watchdog(watchdog_ifnum);
1340
1341 #ifdef HAVE_DIE_NMI
1342 if (nmi_handler_registered)
1343 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1344 #endif
1345
1346 unregister_reboot_notifier(&wdog_reboot_notifier);
1347 }
1348 module_exit(ipmi_wdog_exit);
1349 module_init(ipmi_wdog_init);
1350 MODULE_LICENSE("GPL");
1351 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1352 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");
1353