xref: /linux/drivers/char/ipmi/ipmi_watchdog.c (revision bb1c928df78ee6e3665a0d013e74108cc9abf34b)
1 /*
2  * ipmi_watchdog.c
3  *
4  * A watchdog timer based upon the IPMI interface.
5  *
6  * Author: MontaVista Software, Inc.
7  *         Corey Minyard <minyard@mvista.com>
8  *         source@mvista.com
9  *
10  * Copyright 2002 MontaVista Software Inc.
11  *
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.
16  *
17  *
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.
28  *
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.
32  */
33 
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/ipmi.h>
37 #include <linux/ipmi_smi.h>
38 #include <linux/mutex.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 <linux/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 <linux/atomic.h>
56 #include <linux/sched/signal.h>
57 
58 #ifdef CONFIG_X86
59 /*
60  * This is ugly, but I've determined that x86 is the only architecture
61  * that can reasonably support the IPMI NMI watchdog timeout at this
62  * time.  If another architecture adds this capability somehow, it
63  * will have to be a somewhat different mechanism and I have no idea
64  * how it will work.  So in the unlikely event that another
65  * architecture supports this, we can figure out a good generic
66  * mechanism for it at that time.
67  */
68 #include <asm/kdebug.h>
69 #include <asm/nmi.h>
70 #define HAVE_DIE_NMI
71 #endif
72 
73 #define	PFX "IPMI Watchdog: "
74 
75 /*
76  * The IPMI command/response information for the watchdog timer.
77  */
78 
79 /* values for byte 1 of the set command, byte 2 of the get response. */
80 #define WDOG_DONT_LOG		(1 << 7)
81 #define WDOG_DONT_STOP_ON_SET	(1 << 6)
82 #define WDOG_SET_TIMER_USE(byte, use) \
83 	byte = ((byte) & 0xf8) | ((use) & 0x7)
84 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
85 #define WDOG_TIMER_USE_BIOS_FRB2	1
86 #define WDOG_TIMER_USE_BIOS_POST	2
87 #define WDOG_TIMER_USE_OS_LOAD		3
88 #define WDOG_TIMER_USE_SMS_OS		4
89 #define WDOG_TIMER_USE_OEM		5
90 
91 /* values for byte 2 of the set command, byte 3 of the get response. */
92 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
93 	byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
94 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
95 #define WDOG_PRETIMEOUT_NONE		0
96 #define WDOG_PRETIMEOUT_SMI		1
97 #define WDOG_PRETIMEOUT_NMI		2
98 #define WDOG_PRETIMEOUT_MSG_INT		3
99 
100 /* Operations that can be performed on a pretimout. */
101 #define WDOG_PREOP_NONE		0
102 #define WDOG_PREOP_PANIC	1
103 /* Cause data to be available to read.  Doesn't work in NMI mode. */
104 #define WDOG_PREOP_GIVE_DATA	2
105 
106 /* Actions to perform on a full timeout. */
107 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
108 	byte = ((byte) & 0xf8) | ((use) & 0x7)
109 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
110 #define WDOG_TIMEOUT_NONE		0
111 #define WDOG_TIMEOUT_RESET		1
112 #define WDOG_TIMEOUT_POWER_DOWN		2
113 #define WDOG_TIMEOUT_POWER_CYCLE	3
114 
115 /*
116  * Byte 3 of the get command, byte 4 of the get response is the
117  * pre-timeout in seconds.
118  */
119 
120 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
121 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2	(1 << 1)
122 #define WDOG_EXPIRE_CLEAR_BIOS_POST	(1 << 2)
123 #define WDOG_EXPIRE_CLEAR_OS_LOAD	(1 << 3)
124 #define WDOG_EXPIRE_CLEAR_SMS_OS	(1 << 4)
125 #define WDOG_EXPIRE_CLEAR_OEM		(1 << 5)
126 
127 /*
128  * Setting/getting the watchdog timer value.  This is for bytes 5 and
129  * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
130  * timeout time) and 8 and 9 (the current countdown value) of the
131  * response.  The timeout value is given in seconds (in the command it
132  * is 100ms intervals).
133  */
134 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
135 	(byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
136 #define WDOG_GET_TIMEOUT(byte1, byte2) \
137 	(((byte1) | ((byte2) << 8)) / 10)
138 
139 #define IPMI_WDOG_RESET_TIMER		0x22
140 #define IPMI_WDOG_SET_TIMER		0x24
141 #define IPMI_WDOG_GET_TIMER		0x25
142 
143 #define IPMI_WDOG_TIMER_NOT_INIT_RESP	0x80
144 
145 static DEFINE_MUTEX(ipmi_watchdog_mutex);
146 static bool nowayout = WATCHDOG_NOWAYOUT;
147 
148 static ipmi_user_t watchdog_user;
149 static int watchdog_ifnum;
150 
151 /* Default the timeout to 10 seconds. */
152 static int timeout = 10;
153 
154 /* The pre-timeout is disabled by default. */
155 static int pretimeout;
156 
157 /* Default timeout to set on panic */
158 static int panic_wdt_timeout = 255;
159 
160 /* Default action is to reset the board on a timeout. */
161 static unsigned char action_val = WDOG_TIMEOUT_RESET;
162 
163 static char action[16] = "reset";
164 
165 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
166 
167 static char preaction[16] = "pre_none";
168 
169 static unsigned char preop_val = WDOG_PREOP_NONE;
170 
171 static char preop[16] = "preop_none";
172 static DEFINE_SPINLOCK(ipmi_read_lock);
173 static char data_to_read;
174 static DECLARE_WAIT_QUEUE_HEAD(read_q);
175 static struct fasync_struct *fasync_q;
176 static char pretimeout_since_last_heartbeat;
177 static char expect_close;
178 
179 static int ifnum_to_use = -1;
180 
181 /* Parameters to ipmi_set_timeout */
182 #define IPMI_SET_TIMEOUT_NO_HB			0
183 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY	1
184 #define IPMI_SET_TIMEOUT_FORCE_HB		2
185 
186 static int ipmi_set_timeout(int do_heartbeat);
187 static void ipmi_register_watchdog(int ipmi_intf);
188 static void ipmi_unregister_watchdog(int ipmi_intf);
189 
190 /*
191  * If true, the driver will start running as soon as it is configured
192  * and ready.
193  */
194 static int start_now;
195 
196 static int set_param_timeout(const char *val, const struct kernel_param *kp)
197 {
198 	char *endp;
199 	int  l;
200 	int  rv = 0;
201 
202 	if (!val)
203 		return -EINVAL;
204 	l = simple_strtoul(val, &endp, 0);
205 	if (endp == val)
206 		return -EINVAL;
207 
208 	*((int *)kp->arg) = l;
209 	if (watchdog_user)
210 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
211 
212 	return rv;
213 }
214 
215 static const struct kernel_param_ops param_ops_timeout = {
216 	.set = set_param_timeout,
217 	.get = param_get_int,
218 };
219 #define param_check_timeout param_check_int
220 
221 typedef int (*action_fn)(const char *intval, char *outval);
222 
223 static int action_op(const char *inval, char *outval);
224 static int preaction_op(const char *inval, char *outval);
225 static int preop_op(const char *inval, char *outval);
226 static void check_parms(void);
227 
228 static int set_param_str(const char *val, const struct kernel_param *kp)
229 {
230 	action_fn  fn = (action_fn) kp->arg;
231 	int        rv = 0;
232 	char       valcp[16];
233 	char       *s;
234 
235 	strncpy(valcp, val, 16);
236 	valcp[15] = '\0';
237 
238 	s = strstrip(valcp);
239 
240 	rv = fn(s, NULL);
241 	if (rv)
242 		goto out;
243 
244 	check_parms();
245 	if (watchdog_user)
246 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
247 
248  out:
249 	return rv;
250 }
251 
252 static int get_param_str(char *buffer, const struct kernel_param *kp)
253 {
254 	action_fn fn = (action_fn) kp->arg;
255 	int       rv;
256 
257 	rv = fn(NULL, buffer);
258 	if (rv)
259 		return rv;
260 	return strlen(buffer);
261 }
262 
263 
264 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp)
265 {
266 	int rv = param_set_int(val, kp);
267 	if (rv)
268 		return rv;
269 	if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
270 		return 0;
271 
272 	ipmi_unregister_watchdog(watchdog_ifnum);
273 	ipmi_register_watchdog(ifnum_to_use);
274 	return 0;
275 }
276 
277 static const struct kernel_param_ops param_ops_wdog_ifnum = {
278 	.set = set_param_wdog_ifnum,
279 	.get = param_get_int,
280 };
281 
282 #define param_check_wdog_ifnum param_check_int
283 
284 static const struct kernel_param_ops param_ops_str = {
285 	.set = set_param_str,
286 	.get = get_param_str,
287 };
288 
289 module_param(ifnum_to_use, wdog_ifnum, 0644);
290 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
291 		 "timer.  Setting to -1 defaults to the first registered "
292 		 "interface");
293 
294 module_param(timeout, timeout, 0644);
295 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
296 
297 module_param(pretimeout, timeout, 0644);
298 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
299 
300 module_param(panic_wdt_timeout, timeout, 0644);
301 MODULE_PARM_DESC(timeout, "Timeout value on kernel panic in seconds.");
302 
303 module_param_cb(action, &param_ops_str, action_op, 0644);
304 MODULE_PARM_DESC(action, "Timeout action. One of: "
305 		 "reset, none, power_cycle, power_off.");
306 
307 module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
308 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
309 		 "pre_none, pre_smi, pre_nmi, pre_int.");
310 
311 module_param_cb(preop, &param_ops_str, preop_op, 0644);
312 MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
313 		 "preop_none, preop_panic, preop_give_data.");
314 
315 module_param(start_now, int, 0444);
316 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
317 		 "soon as the driver is loaded.");
318 
319 module_param(nowayout, bool, 0644);
320 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
321 		 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
322 
323 /* Default state of the timer. */
324 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
325 
326 /* If shutting down via IPMI, we ignore the heartbeat. */
327 static int ipmi_ignore_heartbeat;
328 
329 /* Is someone using the watchdog?  Only one user is allowed. */
330 static unsigned long ipmi_wdog_open;
331 
332 /*
333  * If set to 1, the heartbeat command will set the state to reset and
334  * start the timer.  The timer doesn't normally run when the driver is
335  * first opened until the heartbeat is set the first time, this
336  * variable is used to accomplish this.
337  */
338 static int ipmi_start_timer_on_heartbeat;
339 
340 /* IPMI version of the BMC. */
341 static unsigned char ipmi_version_major;
342 static unsigned char ipmi_version_minor;
343 
344 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
345 static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
346 
347 #ifdef HAVE_DIE_NMI
348 static int testing_nmi;
349 static int nmi_handler_registered;
350 #endif
351 
352 static int ipmi_heartbeat(void);
353 
354 /*
355  * We use a mutex to make sure that only one thing can send a set
356  * timeout at one time, because we only have one copy of the data.
357  * The mutex is claimed when the set_timeout is sent and freed
358  * when both messages are free.
359  */
360 static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
361 static DEFINE_MUTEX(set_timeout_lock);
362 static DECLARE_COMPLETION(set_timeout_wait);
363 static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
364 {
365     if (atomic_dec_and_test(&set_timeout_tofree))
366 	    complete(&set_timeout_wait);
367 }
368 static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
369 {
370     if (atomic_dec_and_test(&set_timeout_tofree))
371 	    complete(&set_timeout_wait);
372 }
373 static struct ipmi_smi_msg set_timeout_smi_msg = {
374 	.done = set_timeout_free_smi
375 };
376 static struct ipmi_recv_msg set_timeout_recv_msg = {
377 	.done = set_timeout_free_recv
378 };
379 
380 static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
381 			      struct ipmi_recv_msg *recv_msg,
382 			      int                  *send_heartbeat_now)
383 {
384 	struct kernel_ipmi_msg            msg;
385 	unsigned char                     data[6];
386 	int                               rv;
387 	struct ipmi_system_interface_addr addr;
388 	int                               hbnow = 0;
389 
390 
391 	/* These can be cleared as we are setting the timeout. */
392 	pretimeout_since_last_heartbeat = 0;
393 
394 	data[0] = 0;
395 	WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
396 
397 	if ((ipmi_version_major > 1)
398 	    || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
399 		/* This is an IPMI 1.5-only feature. */
400 		data[0] |= WDOG_DONT_STOP_ON_SET;
401 	} else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
402 		/*
403 		 * In ipmi 1.0, setting the timer stops the watchdog, we
404 		 * need to start it back up again.
405 		 */
406 		hbnow = 1;
407 	}
408 
409 	data[1] = 0;
410 	WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
411 	if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
412 	    WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
413 	    data[2] = pretimeout;
414 	} else {
415 	    WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
416 	    data[2] = 0; /* No pretimeout. */
417 	}
418 	data[3] = 0;
419 	WDOG_SET_TIMEOUT(data[4], data[5], timeout);
420 
421 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
422 	addr.channel = IPMI_BMC_CHANNEL;
423 	addr.lun = 0;
424 
425 	msg.netfn = 0x06;
426 	msg.cmd = IPMI_WDOG_SET_TIMER;
427 	msg.data = data;
428 	msg.data_len = sizeof(data);
429 	rv = ipmi_request_supply_msgs(watchdog_user,
430 				      (struct ipmi_addr *) &addr,
431 				      0,
432 				      &msg,
433 				      NULL,
434 				      smi_msg,
435 				      recv_msg,
436 				      1);
437 	if (rv) {
438 		printk(KERN_WARNING PFX "set timeout error: %d\n",
439 		       rv);
440 	}
441 
442 	if (send_heartbeat_now)
443 	    *send_heartbeat_now = hbnow;
444 
445 	return rv;
446 }
447 
448 static int ipmi_set_timeout(int do_heartbeat)
449 {
450 	int send_heartbeat_now;
451 	int rv;
452 
453 
454 	/* We can only send one of these at a time. */
455 	mutex_lock(&set_timeout_lock);
456 
457 	atomic_set(&set_timeout_tofree, 2);
458 
459 	rv = i_ipmi_set_timeout(&set_timeout_smi_msg,
460 				&set_timeout_recv_msg,
461 				&send_heartbeat_now);
462 	if (rv) {
463 		mutex_unlock(&set_timeout_lock);
464 		goto out;
465 	}
466 
467 	wait_for_completion(&set_timeout_wait);
468 
469 	mutex_unlock(&set_timeout_lock);
470 
471 	if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
472 	    || ((send_heartbeat_now)
473 		&& (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
474 		rv = ipmi_heartbeat();
475 
476 out:
477 	return rv;
478 }
479 
480 static atomic_t panic_done_count = ATOMIC_INIT(0);
481 
482 static void panic_smi_free(struct ipmi_smi_msg *msg)
483 {
484 	atomic_dec(&panic_done_count);
485 }
486 static void panic_recv_free(struct ipmi_recv_msg *msg)
487 {
488 	atomic_dec(&panic_done_count);
489 }
490 
491 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
492 	.done = panic_smi_free
493 };
494 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
495 	.done = panic_recv_free
496 };
497 
498 static void panic_halt_ipmi_heartbeat(void)
499 {
500 	struct kernel_ipmi_msg             msg;
501 	struct ipmi_system_interface_addr addr;
502 	int rv;
503 
504 	/*
505 	 * Don't reset the timer if we have the timer turned off, that
506 	 * re-enables the watchdog.
507 	 */
508 	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
509 		return;
510 
511 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
512 	addr.channel = IPMI_BMC_CHANNEL;
513 	addr.lun = 0;
514 
515 	msg.netfn = 0x06;
516 	msg.cmd = IPMI_WDOG_RESET_TIMER;
517 	msg.data = NULL;
518 	msg.data_len = 0;
519 	atomic_add(1, &panic_done_count);
520 	rv = ipmi_request_supply_msgs(watchdog_user,
521 				      (struct ipmi_addr *) &addr,
522 				      0,
523 				      &msg,
524 				      NULL,
525 				      &panic_halt_heartbeat_smi_msg,
526 				      &panic_halt_heartbeat_recv_msg,
527 				      1);
528 	if (rv)
529 		atomic_sub(1, &panic_done_count);
530 }
531 
532 static struct ipmi_smi_msg panic_halt_smi_msg = {
533 	.done = panic_smi_free
534 };
535 static struct ipmi_recv_msg panic_halt_recv_msg = {
536 	.done = panic_recv_free
537 };
538 
539 /*
540  * Special call, doesn't claim any locks.  This is only to be called
541  * at panic or halt time, in run-to-completion mode, when the caller
542  * is the only CPU and the only thing that will be going is these IPMI
543  * calls.
544  */
545 static void panic_halt_ipmi_set_timeout(void)
546 {
547 	int send_heartbeat_now;
548 	int rv;
549 
550 	/* Wait for the messages to be free. */
551 	while (atomic_read(&panic_done_count) != 0)
552 		ipmi_poll_interface(watchdog_user);
553 	atomic_add(1, &panic_done_count);
554 	rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
555 				&panic_halt_recv_msg,
556 				&send_heartbeat_now);
557 	if (rv) {
558 		atomic_sub(1, &panic_done_count);
559 		printk(KERN_WARNING PFX
560 		       "Unable to extend the watchdog timeout.");
561 	} else {
562 		if (send_heartbeat_now)
563 			panic_halt_ipmi_heartbeat();
564 	}
565 	while (atomic_read(&panic_done_count) != 0)
566 		ipmi_poll_interface(watchdog_user);
567 }
568 
569 /*
570  * We use a mutex to make sure that only one thing can send a
571  * heartbeat at one time, because we only have one copy of the data.
572  * The semaphore is claimed when the set_timeout is sent and freed
573  * when both messages are free.
574  */
575 static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
576 static DEFINE_MUTEX(heartbeat_lock);
577 static DECLARE_COMPLETION(heartbeat_wait);
578 static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
579 {
580     if (atomic_dec_and_test(&heartbeat_tofree))
581 	    complete(&heartbeat_wait);
582 }
583 static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
584 {
585     if (atomic_dec_and_test(&heartbeat_tofree))
586 	    complete(&heartbeat_wait);
587 }
588 static struct ipmi_smi_msg heartbeat_smi_msg = {
589 	.done = heartbeat_free_smi
590 };
591 static struct ipmi_recv_msg heartbeat_recv_msg = {
592 	.done = heartbeat_free_recv
593 };
594 
595 static int ipmi_heartbeat(void)
596 {
597 	struct kernel_ipmi_msg            msg;
598 	int                               rv;
599 	struct ipmi_system_interface_addr addr;
600 	int				  timeout_retries = 0;
601 
602 	if (ipmi_ignore_heartbeat)
603 		return 0;
604 
605 	if (ipmi_start_timer_on_heartbeat) {
606 		ipmi_start_timer_on_heartbeat = 0;
607 		ipmi_watchdog_state = action_val;
608 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
609 	} else if (pretimeout_since_last_heartbeat) {
610 		/*
611 		 * A pretimeout occurred, make sure we set the timeout.
612 		 * We don't want to set the action, though, we want to
613 		 * leave that alone (thus it can't be combined with the
614 		 * above operation.
615 		 */
616 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
617 	}
618 
619 	mutex_lock(&heartbeat_lock);
620 
621 restart:
622 	atomic_set(&heartbeat_tofree, 2);
623 
624 	/*
625 	 * Don't reset the timer if we have the timer turned off, that
626 	 * re-enables the watchdog.
627 	 */
628 	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
629 		mutex_unlock(&heartbeat_lock);
630 		return 0;
631 	}
632 
633 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
634 	addr.channel = IPMI_BMC_CHANNEL;
635 	addr.lun = 0;
636 
637 	msg.netfn = 0x06;
638 	msg.cmd = IPMI_WDOG_RESET_TIMER;
639 	msg.data = NULL;
640 	msg.data_len = 0;
641 	rv = ipmi_request_supply_msgs(watchdog_user,
642 				      (struct ipmi_addr *) &addr,
643 				      0,
644 				      &msg,
645 				      NULL,
646 				      &heartbeat_smi_msg,
647 				      &heartbeat_recv_msg,
648 				      1);
649 	if (rv) {
650 		mutex_unlock(&heartbeat_lock);
651 		printk(KERN_WARNING PFX "heartbeat failure: %d\n",
652 		       rv);
653 		return rv;
654 	}
655 
656 	/* Wait for the heartbeat to be sent. */
657 	wait_for_completion(&heartbeat_wait);
658 
659 	if (heartbeat_recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)  {
660 		timeout_retries++;
661 		if (timeout_retries > 3) {
662 			printk(KERN_ERR PFX ": Unable to restore the IPMI"
663 			       " watchdog's settings, giving up.\n");
664 			rv = -EIO;
665 			goto out_unlock;
666 		}
667 
668 		/*
669 		 * The timer was not initialized, that means the BMC was
670 		 * probably reset and lost the watchdog information.  Attempt
671 		 * to restore the timer's info.  Note that we still hold
672 		 * the heartbeat lock, to keep a heartbeat from happening
673 		 * in this process, so must say no heartbeat to avoid a
674 		 * deadlock on this mutex.
675 		 */
676 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
677 		if (rv) {
678 			printk(KERN_ERR PFX ": Unable to send the command to"
679 			       " set the watchdog's settings, giving up.\n");
680 			goto out_unlock;
681 		}
682 
683 		/* We might need a new heartbeat, so do it now */
684 		goto restart;
685 	} else if (heartbeat_recv_msg.msg.data[0] != 0) {
686 		/*
687 		 * Got an error in the heartbeat response.  It was already
688 		 * reported in ipmi_wdog_msg_handler, but we should return
689 		 * an error here.
690 		 */
691 		rv = -EINVAL;
692 	}
693 
694 out_unlock:
695 	mutex_unlock(&heartbeat_lock);
696 
697 	return rv;
698 }
699 
700 static struct watchdog_info ident = {
701 	.options	= 0,	/* WDIOF_SETTIMEOUT, */
702 	.firmware_version = 1,
703 	.identity	= "IPMI"
704 };
705 
706 static int ipmi_ioctl(struct file *file,
707 		      unsigned int cmd, unsigned long arg)
708 {
709 	void __user *argp = (void __user *)arg;
710 	int i;
711 	int val;
712 
713 	switch (cmd) {
714 	case WDIOC_GETSUPPORT:
715 		i = copy_to_user(argp, &ident, sizeof(ident));
716 		return i ? -EFAULT : 0;
717 
718 	case WDIOC_SETTIMEOUT:
719 		i = copy_from_user(&val, argp, sizeof(int));
720 		if (i)
721 			return -EFAULT;
722 		timeout = val;
723 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
724 
725 	case WDIOC_GETTIMEOUT:
726 		i = copy_to_user(argp, &timeout, sizeof(timeout));
727 		if (i)
728 			return -EFAULT;
729 		return 0;
730 
731 	case WDIOC_SETPRETIMEOUT:
732 		i = copy_from_user(&val, argp, sizeof(int));
733 		if (i)
734 			return -EFAULT;
735 		pretimeout = val;
736 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
737 
738 	case WDIOC_GETPRETIMEOUT:
739 		i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
740 		if (i)
741 			return -EFAULT;
742 		return 0;
743 
744 	case WDIOC_KEEPALIVE:
745 		return ipmi_heartbeat();
746 
747 	case WDIOC_SETOPTIONS:
748 		i = copy_from_user(&val, argp, sizeof(int));
749 		if (i)
750 			return -EFAULT;
751 		if (val & WDIOS_DISABLECARD) {
752 			ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
753 			ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
754 			ipmi_start_timer_on_heartbeat = 0;
755 		}
756 
757 		if (val & WDIOS_ENABLECARD) {
758 			ipmi_watchdog_state = action_val;
759 			ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
760 		}
761 		return 0;
762 
763 	case WDIOC_GETSTATUS:
764 		val = 0;
765 		i = copy_to_user(argp, &val, sizeof(val));
766 		if (i)
767 			return -EFAULT;
768 		return 0;
769 
770 	default:
771 		return -ENOIOCTLCMD;
772 	}
773 }
774 
775 static long ipmi_unlocked_ioctl(struct file *file,
776 				unsigned int cmd,
777 				unsigned long arg)
778 {
779 	int ret;
780 
781 	mutex_lock(&ipmi_watchdog_mutex);
782 	ret = ipmi_ioctl(file, cmd, arg);
783 	mutex_unlock(&ipmi_watchdog_mutex);
784 
785 	return ret;
786 }
787 
788 static ssize_t ipmi_write(struct file *file,
789 			  const char  __user *buf,
790 			  size_t      len,
791 			  loff_t      *ppos)
792 {
793 	int rv;
794 
795 	if (len) {
796 		if (!nowayout) {
797 			size_t i;
798 
799 			/* In case it was set long ago */
800 			expect_close = 0;
801 
802 			for (i = 0; i != len; i++) {
803 				char c;
804 
805 				if (get_user(c, buf + i))
806 					return -EFAULT;
807 				if (c == 'V')
808 					expect_close = 42;
809 			}
810 		}
811 		rv = ipmi_heartbeat();
812 		if (rv)
813 			return rv;
814 	}
815 	return len;
816 }
817 
818 static ssize_t ipmi_read(struct file *file,
819 			 char        __user *buf,
820 			 size_t      count,
821 			 loff_t      *ppos)
822 {
823 	int          rv = 0;
824 	wait_queue_entry_t wait;
825 
826 	if (count <= 0)
827 		return 0;
828 
829 	/*
830 	 * Reading returns if the pretimeout has gone off, and it only does
831 	 * it once per pretimeout.
832 	 */
833 	spin_lock(&ipmi_read_lock);
834 	if (!data_to_read) {
835 		if (file->f_flags & O_NONBLOCK) {
836 			rv = -EAGAIN;
837 			goto out;
838 		}
839 
840 		init_waitqueue_entry(&wait, current);
841 		add_wait_queue(&read_q, &wait);
842 		while (!data_to_read) {
843 			set_current_state(TASK_INTERRUPTIBLE);
844 			spin_unlock(&ipmi_read_lock);
845 			schedule();
846 			spin_lock(&ipmi_read_lock);
847 		}
848 		remove_wait_queue(&read_q, &wait);
849 
850 		if (signal_pending(current)) {
851 			rv = -ERESTARTSYS;
852 			goto out;
853 		}
854 	}
855 	data_to_read = 0;
856 
857  out:
858 	spin_unlock(&ipmi_read_lock);
859 
860 	if (rv == 0) {
861 		if (copy_to_user(buf, &data_to_read, 1))
862 			rv = -EFAULT;
863 		else
864 			rv = 1;
865 	}
866 
867 	return rv;
868 }
869 
870 static int ipmi_open(struct inode *ino, struct file *filep)
871 {
872 	switch (iminor(ino)) {
873 	case WATCHDOG_MINOR:
874 		if (test_and_set_bit(0, &ipmi_wdog_open))
875 			return -EBUSY;
876 
877 
878 		/*
879 		 * Don't start the timer now, let it start on the
880 		 * first heartbeat.
881 		 */
882 		ipmi_start_timer_on_heartbeat = 1;
883 		return nonseekable_open(ino, filep);
884 
885 	default:
886 		return (-ENODEV);
887 	}
888 }
889 
890 static unsigned int ipmi_poll(struct file *file, poll_table *wait)
891 {
892 	unsigned int mask = 0;
893 
894 	poll_wait(file, &read_q, wait);
895 
896 	spin_lock(&ipmi_read_lock);
897 	if (data_to_read)
898 		mask |= (POLLIN | POLLRDNORM);
899 	spin_unlock(&ipmi_read_lock);
900 
901 	return mask;
902 }
903 
904 static int ipmi_fasync(int fd, struct file *file, int on)
905 {
906 	int result;
907 
908 	result = fasync_helper(fd, file, on, &fasync_q);
909 
910 	return (result);
911 }
912 
913 static int ipmi_close(struct inode *ino, struct file *filep)
914 {
915 	if (iminor(ino) == WATCHDOG_MINOR) {
916 		if (expect_close == 42) {
917 			ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
918 			ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
919 		} else {
920 			printk(KERN_CRIT PFX
921 			       "Unexpected close, not stopping watchdog!\n");
922 			ipmi_heartbeat();
923 		}
924 		clear_bit(0, &ipmi_wdog_open);
925 	}
926 
927 	expect_close = 0;
928 
929 	return 0;
930 }
931 
932 static const struct file_operations ipmi_wdog_fops = {
933 	.owner   = THIS_MODULE,
934 	.read    = ipmi_read,
935 	.poll    = ipmi_poll,
936 	.write   = ipmi_write,
937 	.unlocked_ioctl = ipmi_unlocked_ioctl,
938 	.open    = ipmi_open,
939 	.release = ipmi_close,
940 	.fasync  = ipmi_fasync,
941 	.llseek  = no_llseek,
942 };
943 
944 static struct miscdevice ipmi_wdog_miscdev = {
945 	.minor		= WATCHDOG_MINOR,
946 	.name		= "watchdog",
947 	.fops		= &ipmi_wdog_fops
948 };
949 
950 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
951 				  void                 *handler_data)
952 {
953 	if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
954 			msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
955 		printk(KERN_INFO PFX "response: The IPMI controller appears"
956 		       " to have been reset, will attempt to reinitialize"
957 		       " the watchdog timer\n");
958 	else if (msg->msg.data[0] != 0)
959 		printk(KERN_ERR PFX "response: Error %x on cmd %x\n",
960 		       msg->msg.data[0],
961 		       msg->msg.cmd);
962 
963 	ipmi_free_recv_msg(msg);
964 }
965 
966 static void ipmi_wdog_pretimeout_handler(void *handler_data)
967 {
968 	if (preaction_val != WDOG_PRETIMEOUT_NONE) {
969 		if (preop_val == WDOG_PREOP_PANIC) {
970 			if (atomic_inc_and_test(&preop_panic_excl))
971 				panic("Watchdog pre-timeout");
972 		} else if (preop_val == WDOG_PREOP_GIVE_DATA) {
973 			spin_lock(&ipmi_read_lock);
974 			data_to_read = 1;
975 			wake_up_interruptible(&read_q);
976 			kill_fasync(&fasync_q, SIGIO, POLL_IN);
977 
978 			spin_unlock(&ipmi_read_lock);
979 		}
980 	}
981 
982 	/*
983 	 * On some machines, the heartbeat will give an error and not
984 	 * work unless we re-enable the timer.  So do so.
985 	 */
986 	pretimeout_since_last_heartbeat = 1;
987 }
988 
989 static const struct ipmi_user_hndl ipmi_hndlrs = {
990 	.ipmi_recv_hndl           = ipmi_wdog_msg_handler,
991 	.ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler
992 };
993 
994 static void ipmi_register_watchdog(int ipmi_intf)
995 {
996 	int rv = -EBUSY;
997 
998 	if (watchdog_user)
999 		goto out;
1000 
1001 	if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
1002 		goto out;
1003 
1004 	watchdog_ifnum = ipmi_intf;
1005 
1006 	rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
1007 	if (rv < 0) {
1008 		printk(KERN_CRIT PFX "Unable to register with ipmi\n");
1009 		goto out;
1010 	}
1011 
1012 	ipmi_get_version(watchdog_user,
1013 			 &ipmi_version_major,
1014 			 &ipmi_version_minor);
1015 
1016 	rv = misc_register(&ipmi_wdog_miscdev);
1017 	if (rv < 0) {
1018 		ipmi_destroy_user(watchdog_user);
1019 		watchdog_user = NULL;
1020 		printk(KERN_CRIT PFX "Unable to register misc device\n");
1021 	}
1022 
1023 #ifdef HAVE_DIE_NMI
1024 	if (nmi_handler_registered) {
1025 		int old_pretimeout = pretimeout;
1026 		int old_timeout = timeout;
1027 		int old_preop_val = preop_val;
1028 
1029 		/*
1030 		 * Set the pretimeout to go off in a second and give
1031 		 * ourselves plenty of time to stop the timer.
1032 		 */
1033 		ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1034 		preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
1035 		pretimeout = 99;
1036 		timeout = 100;
1037 
1038 		testing_nmi = 1;
1039 
1040 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1041 		if (rv) {
1042 			printk(KERN_WARNING PFX "Error starting timer to"
1043 			       " test NMI: 0x%x.  The NMI pretimeout will"
1044 			       " likely not work\n", rv);
1045 			rv = 0;
1046 			goto out_restore;
1047 		}
1048 
1049 		msleep(1500);
1050 
1051 		if (testing_nmi != 2) {
1052 			printk(KERN_WARNING PFX "IPMI NMI didn't seem to"
1053 			       " occur.  The NMI pretimeout will"
1054 			       " likely not work\n");
1055 		}
1056  out_restore:
1057 		testing_nmi = 0;
1058 		preop_val = old_preop_val;
1059 		pretimeout = old_pretimeout;
1060 		timeout = old_timeout;
1061 	}
1062 #endif
1063 
1064  out:
1065 	if ((start_now) && (rv == 0)) {
1066 		/* Run from startup, so start the timer now. */
1067 		start_now = 0; /* Disable this function after first startup. */
1068 		ipmi_watchdog_state = action_val;
1069 		ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1070 		printk(KERN_INFO PFX "Starting now!\n");
1071 	} else {
1072 		/* Stop the timer now. */
1073 		ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1074 		ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1075 	}
1076 }
1077 
1078 static void ipmi_unregister_watchdog(int ipmi_intf)
1079 {
1080 	int rv;
1081 
1082 	if (!watchdog_user)
1083 		goto out;
1084 
1085 	if (watchdog_ifnum != ipmi_intf)
1086 		goto out;
1087 
1088 	/* Make sure no one can call us any more. */
1089 	misc_deregister(&ipmi_wdog_miscdev);
1090 
1091 	/*
1092 	 * Wait to make sure the message makes it out.  The lower layer has
1093 	 * pointers to our buffers, we want to make sure they are done before
1094 	 * we release our memory.
1095 	 */
1096 	while (atomic_read(&set_timeout_tofree))
1097 		schedule_timeout_uninterruptible(1);
1098 
1099 	/* Disconnect from IPMI. */
1100 	rv = ipmi_destroy_user(watchdog_user);
1101 	if (rv) {
1102 		printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
1103 		       rv);
1104 	}
1105 	watchdog_user = NULL;
1106 
1107  out:
1108 	return;
1109 }
1110 
1111 #ifdef HAVE_DIE_NMI
1112 static int
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 		pretimeout_since_last_heartbeat = 1;
1143 		if (atomic_inc_and_test(&preop_panic_excl))
1144 			nmi_panic(regs, PFX "pre-timeout");
1145 	}
1146 
1147 	return NMI_HANDLED;
1148 }
1149 #endif
1150 
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 
1185 static int wdog_panic_handler(struct notifier_block *this,
1186 			      unsigned long         event,
1187 			      void                  *unused)
1188 {
1189 	static int panic_event_handled;
1190 
1191 	/* On a panic, if we have a panic timeout, make sure to extend
1192 	   the watchdog timer to a reasonable value to complete the
1193 	   panic, if the watchdog timer is running.  Plus the
1194 	   pretimeout is meaningless at panic time. */
1195 	if (watchdog_user && !panic_event_handled &&
1196 	    ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1197 		/* Make sure we do this only once. */
1198 		panic_event_handled = 1;
1199 
1200 		timeout = panic_wdt_timeout;
1201 		pretimeout = 0;
1202 		panic_halt_ipmi_set_timeout();
1203 	}
1204 
1205 	return NOTIFY_OK;
1206 }
1207 
1208 static struct notifier_block wdog_panic_notifier = {
1209 	.notifier_call	= wdog_panic_handler,
1210 	.next		= NULL,
1211 	.priority	= 150	/* priority: INT_MAX >= x >= 0 */
1212 };
1213 
1214 
1215 static void ipmi_new_smi(int if_num, struct device *device)
1216 {
1217 	ipmi_register_watchdog(if_num);
1218 }
1219 
1220 static void ipmi_smi_gone(int if_num)
1221 {
1222 	ipmi_unregister_watchdog(if_num);
1223 }
1224 
1225 static struct ipmi_smi_watcher smi_watcher = {
1226 	.owner    = THIS_MODULE,
1227 	.new_smi  = ipmi_new_smi,
1228 	.smi_gone = ipmi_smi_gone
1229 };
1230 
1231 static int action_op(const char *inval, char *outval)
1232 {
1233 	if (outval)
1234 		strcpy(outval, action);
1235 
1236 	if (!inval)
1237 		return 0;
1238 
1239 	if (strcmp(inval, "reset") == 0)
1240 		action_val = WDOG_TIMEOUT_RESET;
1241 	else if (strcmp(inval, "none") == 0)
1242 		action_val = WDOG_TIMEOUT_NONE;
1243 	else if (strcmp(inval, "power_cycle") == 0)
1244 		action_val = WDOG_TIMEOUT_POWER_CYCLE;
1245 	else if (strcmp(inval, "power_off") == 0)
1246 		action_val = WDOG_TIMEOUT_POWER_DOWN;
1247 	else
1248 		return -EINVAL;
1249 	strcpy(action, inval);
1250 	return 0;
1251 }
1252 
1253 static int preaction_op(const char *inval, char *outval)
1254 {
1255 	if (outval)
1256 		strcpy(outval, preaction);
1257 
1258 	if (!inval)
1259 		return 0;
1260 
1261 	if (strcmp(inval, "pre_none") == 0)
1262 		preaction_val = WDOG_PRETIMEOUT_NONE;
1263 	else if (strcmp(inval, "pre_smi") == 0)
1264 		preaction_val = WDOG_PRETIMEOUT_SMI;
1265 #ifdef HAVE_DIE_NMI
1266 	else if (strcmp(inval, "pre_nmi") == 0)
1267 		preaction_val = WDOG_PRETIMEOUT_NMI;
1268 #endif
1269 	else if (strcmp(inval, "pre_int") == 0)
1270 		preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1271 	else
1272 		return -EINVAL;
1273 	strcpy(preaction, inval);
1274 	return 0;
1275 }
1276 
1277 static int preop_op(const char *inval, char *outval)
1278 {
1279 	if (outval)
1280 		strcpy(outval, preop);
1281 
1282 	if (!inval)
1283 		return 0;
1284 
1285 	if (strcmp(inval, "preop_none") == 0)
1286 		preop_val = WDOG_PREOP_NONE;
1287 	else if (strcmp(inval, "preop_panic") == 0)
1288 		preop_val = WDOG_PREOP_PANIC;
1289 	else if (strcmp(inval, "preop_give_data") == 0)
1290 		preop_val = WDOG_PREOP_GIVE_DATA;
1291 	else
1292 		return -EINVAL;
1293 	strcpy(preop, inval);
1294 	return 0;
1295 }
1296 
1297 static void check_parms(void)
1298 {
1299 #ifdef HAVE_DIE_NMI
1300 	int do_nmi = 0;
1301 	int rv;
1302 
1303 	if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1304 		do_nmi = 1;
1305 		if (preop_val == WDOG_PREOP_GIVE_DATA) {
1306 			printk(KERN_WARNING PFX "Pretimeout op is to give data"
1307 			       " but NMI pretimeout is enabled, setting"
1308 			       " pretimeout op to none\n");
1309 			preop_op("preop_none", NULL);
1310 			do_nmi = 0;
1311 		}
1312 	}
1313 	if (do_nmi && !nmi_handler_registered) {
1314 		rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0,
1315 						"ipmi");
1316 		if (rv) {
1317 			printk(KERN_WARNING PFX
1318 			       "Can't register nmi handler\n");
1319 			return;
1320 		} else
1321 			nmi_handler_registered = 1;
1322 	} else if (!do_nmi && nmi_handler_registered) {
1323 		unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1324 		nmi_handler_registered = 0;
1325 	}
1326 #endif
1327 }
1328 
1329 static int __init ipmi_wdog_init(void)
1330 {
1331 	int rv;
1332 
1333 	if (action_op(action, NULL)) {
1334 		action_op("reset", NULL);
1335 		printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
1336 		       " reset\n", action);
1337 	}
1338 
1339 	if (preaction_op(preaction, NULL)) {
1340 		preaction_op("pre_none", NULL);
1341 		printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
1342 		       " none\n", preaction);
1343 	}
1344 
1345 	if (preop_op(preop, NULL)) {
1346 		preop_op("preop_none", NULL);
1347 		printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
1348 		       " none\n", preop);
1349 	}
1350 
1351 	check_parms();
1352 
1353 	register_reboot_notifier(&wdog_reboot_notifier);
1354 	atomic_notifier_chain_register(&panic_notifier_list,
1355 			&wdog_panic_notifier);
1356 
1357 	rv = ipmi_smi_watcher_register(&smi_watcher);
1358 	if (rv) {
1359 #ifdef HAVE_DIE_NMI
1360 		if (nmi_handler_registered)
1361 			unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1362 #endif
1363 		atomic_notifier_chain_unregister(&panic_notifier_list,
1364 						 &wdog_panic_notifier);
1365 		unregister_reboot_notifier(&wdog_reboot_notifier);
1366 		printk(KERN_WARNING PFX "can't register smi watcher\n");
1367 		return rv;
1368 	}
1369 
1370 	printk(KERN_INFO PFX "driver initialized\n");
1371 
1372 	return 0;
1373 }
1374 
1375 static void __exit ipmi_wdog_exit(void)
1376 {
1377 	ipmi_smi_watcher_unregister(&smi_watcher);
1378 	ipmi_unregister_watchdog(watchdog_ifnum);
1379 
1380 #ifdef HAVE_DIE_NMI
1381 	if (nmi_handler_registered)
1382 		unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1383 #endif
1384 
1385 	atomic_notifier_chain_unregister(&panic_notifier_list,
1386 					 &wdog_panic_notifier);
1387 	unregister_reboot_notifier(&wdog_reboot_notifier);
1388 }
1389 module_exit(ipmi_wdog_exit);
1390 module_init(ipmi_wdog_init);
1391 MODULE_LICENSE("GPL");
1392 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1393 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");
1394