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 <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>
56 
57 #ifdef CONFIG_X86
58 /*
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.
66  */
67 #include <asm/kdebug.h>
68 #define HAVE_DIE_NMI
69 #endif
70 
71 #define	PFX "IPMI Watchdog: "
72 
73 /*
74  * The IPMI command/response information for the watchdog timer.
75  */
76 
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
88 
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
97 
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
103 
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
112 
113 /*
114  * Byte 3 of the get command, byte 4 of the get response is the
115  * pre-timeout in seconds.
116  */
117 
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)
124 
125 /*
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).
131  */
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)
136 
137 #define IPMI_WDOG_RESET_TIMER		0x22
138 #define IPMI_WDOG_SET_TIMER		0x24
139 #define IPMI_WDOG_GET_TIMER		0x25
140 
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)
144 #endif
145 #ifndef WDIOC_SET_PRETIMEOUT
146 #define	WDIOC_SET_PRETIMEOUT     _IOW(WATCHDOG_IOCTL_BASE, 21, int)
147 #endif
148 #ifndef WDIOC_GET_PRETIMEOUT
149 #define	WDIOC_GET_PRETIMEOUT     _IOW(WATCHDOG_IOCTL_BASE, 22, int)
150 #endif
151 
152 static DEFINE_MUTEX(ipmi_watchdog_mutex);
153 static int nowayout = WATCHDOG_NOWAYOUT;
154 
155 static ipmi_user_t watchdog_user;
156 static int watchdog_ifnum;
157 
158 /* Default the timeout to 10 seconds. */
159 static int timeout = 10;
160 
161 /* The pre-timeout is disabled by default. */
162 static int pretimeout;
163 
164 /* Default action is to reset the board on a timeout. */
165 static unsigned char action_val = WDOG_TIMEOUT_RESET;
166 
167 static char action[16] = "reset";
168 
169 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
170 
171 static char preaction[16] = "pre_none";
172 
173 static unsigned char preop_val = WDOG_PREOP_NONE;
174 
175 static char preop[16] = "preop_none";
176 static DEFINE_SPINLOCK(ipmi_read_lock);
177 static char data_to_read;
178 static DECLARE_WAIT_QUEUE_HEAD(read_q);
179 static struct fasync_struct *fasync_q;
180 static char pretimeout_since_last_heartbeat;
181 static char expect_close;
182 
183 static int ifnum_to_use = -1;
184 
185 /* Parameters to ipmi_set_timeout */
186 #define IPMI_SET_TIMEOUT_NO_HB			0
187 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY	1
188 #define IPMI_SET_TIMEOUT_FORCE_HB		2
189 
190 static int ipmi_set_timeout(int do_heartbeat);
191 static void ipmi_register_watchdog(int ipmi_intf);
192 static void ipmi_unregister_watchdog(int ipmi_intf);
193 
194 /*
195  * If true, the driver will start running as soon as it is configured
196  * and ready.
197  */
198 static int start_now;
199 
set_param_timeout(const char * val,const struct kernel_param * kp)200 static int set_param_timeout(const char *val, const struct kernel_param *kp)
201 {
202 	char *endp;
203 	int  l;
204 	int  rv = 0;
205 
206 	if (!val)
207 		return -EINVAL;
208 	l = simple_strtoul(val, &endp, 0);
209 	if (endp == val)
210 		return -EINVAL;
211 
212 	*((int *)kp->arg) = l;
213 	if (watchdog_user)
214 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
215 
216 	return rv;
217 }
218 
219 static struct kernel_param_ops param_ops_timeout = {
220 	.set = set_param_timeout,
221 	.get = param_get_int,
222 };
223 #define param_check_timeout param_check_int
224 
225 typedef int (*action_fn)(const char *intval, char *outval);
226 
227 static int action_op(const char *inval, char *outval);
228 static int preaction_op(const char *inval, char *outval);
229 static int preop_op(const char *inval, char *outval);
230 static void check_parms(void);
231 
set_param_str(const char * val,const struct kernel_param * kp)232 static int set_param_str(const char *val, const struct kernel_param *kp)
233 {
234 	action_fn  fn = (action_fn) kp->arg;
235 	int        rv = 0;
236 	char       valcp[16];
237 	char       *s;
238 
239 	strncpy(valcp, val, 16);
240 	valcp[15] = '\0';
241 
242 	s = strstrip(valcp);
243 
244 	rv = fn(s, NULL);
245 	if (rv)
246 		goto out;
247 
248 	check_parms();
249 	if (watchdog_user)
250 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
251 
252  out:
253 	return rv;
254 }
255 
get_param_str(char * buffer,const struct kernel_param * kp)256 static int get_param_str(char *buffer, const struct kernel_param *kp)
257 {
258 	action_fn fn = (action_fn) kp->arg;
259 	int       rv;
260 
261 	rv = fn(NULL, buffer);
262 	if (rv)
263 		return rv;
264 	return strlen(buffer);
265 }
266 
267 
set_param_wdog_ifnum(const char * val,const struct kernel_param * kp)268 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp)
269 {
270 	int rv = param_set_int(val, kp);
271 	if (rv)
272 		return rv;
273 	if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
274 		return 0;
275 
276 	ipmi_unregister_watchdog(watchdog_ifnum);
277 	ipmi_register_watchdog(ifnum_to_use);
278 	return 0;
279 }
280 
281 static struct kernel_param_ops param_ops_wdog_ifnum = {
282 	.set = set_param_wdog_ifnum,
283 	.get = param_get_int,
284 };
285 
286 #define param_check_wdog_ifnum param_check_int
287 
288 static struct kernel_param_ops param_ops_str = {
289 	.set = set_param_str,
290 	.get = get_param_str,
291 };
292 
293 module_param(ifnum_to_use, wdog_ifnum, 0644);
294 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
295 		 "timer.  Setting to -1 defaults to the first registered "
296 		 "interface");
297 
298 module_param(timeout, timeout, 0644);
299 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
300 
301 module_param(pretimeout, timeout, 0644);
302 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
303 
304 module_param_cb(action, &param_ops_str, action_op, 0644);
305 MODULE_PARM_DESC(action, "Timeout action. One of: "
306 		 "reset, none, power_cycle, power_off.");
307 
308 module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
309 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
310 		 "pre_none, pre_smi, pre_nmi, pre_int.");
311 
312 module_param_cb(preop, &param_ops_str, preop_op, 0644);
313 MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
314 		 "preop_none, preop_panic, preop_give_data.");
315 
316 module_param(start_now, int, 0444);
317 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
318 		 "soon as the driver is loaded.");
319 
320 module_param(nowayout, int, 0644);
321 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
322 		 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
323 
324 /* Default state of the timer. */
325 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
326 
327 /* If shutting down via IPMI, we ignore the heartbeat. */
328 static int ipmi_ignore_heartbeat;
329 
330 /* Is someone using the watchdog?  Only one user is allowed. */
331 static unsigned long ipmi_wdog_open;
332 
333 /*
334  * If set to 1, the heartbeat command will set the state to reset and
335  * start the timer.  The timer doesn't normally run when the driver is
336  * first opened until the heartbeat is set the first time, this
337  * variable is used to accomplish this.
338  */
339 static int ipmi_start_timer_on_heartbeat;
340 
341 /* IPMI version of the BMC. */
342 static unsigned char ipmi_version_major;
343 static unsigned char ipmi_version_minor;
344 
345 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
346 static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
347 
348 #ifdef HAVE_DIE_NMI
349 static int testing_nmi;
350 static int nmi_handler_registered;
351 #endif
352 
353 static int ipmi_heartbeat(void);
354 
355 /*
356  * We use a mutex to make sure that only one thing can send a set
357  * timeout at one time, because we only have one copy of the data.
358  * The mutex is claimed when the set_timeout is sent and freed
359  * when both messages are free.
360  */
361 static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
362 static DEFINE_MUTEX(set_timeout_lock);
363 static DECLARE_COMPLETION(set_timeout_wait);
set_timeout_free_smi(struct ipmi_smi_msg * msg)364 static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
365 {
366     if (atomic_dec_and_test(&set_timeout_tofree))
367 	    complete(&set_timeout_wait);
368 }
set_timeout_free_recv(struct ipmi_recv_msg * msg)369 static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
370 {
371     if (atomic_dec_and_test(&set_timeout_tofree))
372 	    complete(&set_timeout_wait);
373 }
374 static struct ipmi_smi_msg set_timeout_smi_msg = {
375 	.done = set_timeout_free_smi
376 };
377 static struct ipmi_recv_msg set_timeout_recv_msg = {
378 	.done = set_timeout_free_recv
379 };
380 
i_ipmi_set_timeout(struct ipmi_smi_msg * smi_msg,struct ipmi_recv_msg * recv_msg,int * send_heartbeat_now)381 static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
382 			      struct ipmi_recv_msg *recv_msg,
383 			      int                  *send_heartbeat_now)
384 {
385 	struct kernel_ipmi_msg            msg;
386 	unsigned char                     data[6];
387 	int                               rv;
388 	struct ipmi_system_interface_addr addr;
389 	int                               hbnow = 0;
390 
391 
392 	/* These can be cleared as we are setting the timeout. */
393 	pretimeout_since_last_heartbeat = 0;
394 
395 	data[0] = 0;
396 	WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
397 
398 	if ((ipmi_version_major > 1)
399 	    || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
400 		/* This is an IPMI 1.5-only feature. */
401 		data[0] |= WDOG_DONT_STOP_ON_SET;
402 	} else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
403 		/*
404 		 * In ipmi 1.0, setting the timer stops the watchdog, we
405 		 * need to start it back up again.
406 		 */
407 		hbnow = 1;
408 	}
409 
410 	data[1] = 0;
411 	WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
412 	if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
413 	    WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
414 	    data[2] = pretimeout;
415 	} else {
416 	    WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
417 	    data[2] = 0; /* No pretimeout. */
418 	}
419 	data[3] = 0;
420 	WDOG_SET_TIMEOUT(data[4], data[5], timeout);
421 
422 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
423 	addr.channel = IPMI_BMC_CHANNEL;
424 	addr.lun = 0;
425 
426 	msg.netfn = 0x06;
427 	msg.cmd = IPMI_WDOG_SET_TIMER;
428 	msg.data = data;
429 	msg.data_len = sizeof(data);
430 	rv = ipmi_request_supply_msgs(watchdog_user,
431 				      (struct ipmi_addr *) &addr,
432 				      0,
433 				      &msg,
434 				      NULL,
435 				      smi_msg,
436 				      recv_msg,
437 				      1);
438 	if (rv) {
439 		printk(KERN_WARNING PFX "set timeout error: %d\n",
440 		       rv);
441 	}
442 
443 	if (send_heartbeat_now)
444 	    *send_heartbeat_now = hbnow;
445 
446 	return rv;
447 }
448 
ipmi_set_timeout(int do_heartbeat)449 static int ipmi_set_timeout(int do_heartbeat)
450 {
451 	int send_heartbeat_now;
452 	int rv;
453 
454 
455 	/* We can only send one of these at a time. */
456 	mutex_lock(&set_timeout_lock);
457 
458 	atomic_set(&set_timeout_tofree, 2);
459 
460 	rv = i_ipmi_set_timeout(&set_timeout_smi_msg,
461 				&set_timeout_recv_msg,
462 				&send_heartbeat_now);
463 	if (rv) {
464 		mutex_unlock(&set_timeout_lock);
465 		goto out;
466 	}
467 
468 	wait_for_completion(&set_timeout_wait);
469 
470 	mutex_unlock(&set_timeout_lock);
471 
472 	if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
473 	    || ((send_heartbeat_now)
474 		&& (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
475 		rv = ipmi_heartbeat();
476 
477 out:
478 	return rv;
479 }
480 
481 static atomic_t panic_done_count = ATOMIC_INIT(0);
482 
panic_smi_free(struct ipmi_smi_msg * msg)483 static void panic_smi_free(struct ipmi_smi_msg *msg)
484 {
485 	atomic_dec(&panic_done_count);
486 }
panic_recv_free(struct ipmi_recv_msg * msg)487 static void panic_recv_free(struct ipmi_recv_msg *msg)
488 {
489 	atomic_dec(&panic_done_count);
490 }
491 
492 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
493 	.done = panic_smi_free
494 };
495 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
496 	.done = panic_recv_free
497 };
498 
panic_halt_ipmi_heartbeat(void)499 static void panic_halt_ipmi_heartbeat(void)
500 {
501 	struct kernel_ipmi_msg             msg;
502 	struct ipmi_system_interface_addr addr;
503 	int rv;
504 
505 	/*
506 	 * Don't reset the timer if we have the timer turned off, that
507 	 * re-enables the watchdog.
508 	 */
509 	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
510 		return;
511 
512 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
513 	addr.channel = IPMI_BMC_CHANNEL;
514 	addr.lun = 0;
515 
516 	msg.netfn = 0x06;
517 	msg.cmd = IPMI_WDOG_RESET_TIMER;
518 	msg.data = NULL;
519 	msg.data_len = 0;
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_add(2, &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  */
panic_halt_ipmi_set_timeout(void)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 	rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
554 				&panic_halt_recv_msg,
555 				&send_heartbeat_now);
556 	if (!rv) {
557 		atomic_add(2, &panic_done_count);
558 		if (send_heartbeat_now)
559 			panic_halt_ipmi_heartbeat();
560 	} else
561 		printk(KERN_WARNING PFX
562 		       "Unable to extend the watchdog timeout.");
563 	while (atomic_read(&panic_done_count) != 0)
564 		ipmi_poll_interface(watchdog_user);
565 }
566 
567 /*
568  * We use a mutex to make sure that only one thing can send a
569  * heartbeat at one time, because we only have one copy of the data.
570  * The semaphore is claimed when the set_timeout is sent and freed
571  * when both messages are free.
572  */
573 static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
574 static DEFINE_MUTEX(heartbeat_lock);
575 static DECLARE_COMPLETION(heartbeat_wait);
heartbeat_free_smi(struct ipmi_smi_msg * msg)576 static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
577 {
578     if (atomic_dec_and_test(&heartbeat_tofree))
579 	    complete(&heartbeat_wait);
580 }
heartbeat_free_recv(struct ipmi_recv_msg * msg)581 static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
582 {
583     if (atomic_dec_and_test(&heartbeat_tofree))
584 	    complete(&heartbeat_wait);
585 }
586 static struct ipmi_smi_msg heartbeat_smi_msg = {
587 	.done = heartbeat_free_smi
588 };
589 static struct ipmi_recv_msg heartbeat_recv_msg = {
590 	.done = heartbeat_free_recv
591 };
592 
ipmi_heartbeat(void)593 static int ipmi_heartbeat(void)
594 {
595 	struct kernel_ipmi_msg            msg;
596 	int                               rv;
597 	struct ipmi_system_interface_addr addr;
598 
599 	if (ipmi_ignore_heartbeat)
600 		return 0;
601 
602 	if (ipmi_start_timer_on_heartbeat) {
603 		ipmi_start_timer_on_heartbeat = 0;
604 		ipmi_watchdog_state = action_val;
605 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
606 	} else if (pretimeout_since_last_heartbeat) {
607 		/*
608 		 * A pretimeout occurred, make sure we set the timeout.
609 		 * We don't want to set the action, though, we want to
610 		 * leave that alone (thus it can't be combined with the
611 		 * above operation.
612 		 */
613 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
614 	}
615 
616 	mutex_lock(&heartbeat_lock);
617 
618 	atomic_set(&heartbeat_tofree, 2);
619 
620 	/*
621 	 * Don't reset the timer if we have the timer turned off, that
622 	 * re-enables the watchdog.
623 	 */
624 	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
625 		mutex_unlock(&heartbeat_lock);
626 		return 0;
627 	}
628 
629 	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
630 	addr.channel = IPMI_BMC_CHANNEL;
631 	addr.lun = 0;
632 
633 	msg.netfn = 0x06;
634 	msg.cmd = IPMI_WDOG_RESET_TIMER;
635 	msg.data = NULL;
636 	msg.data_len = 0;
637 	rv = ipmi_request_supply_msgs(watchdog_user,
638 				      (struct ipmi_addr *) &addr,
639 				      0,
640 				      &msg,
641 				      NULL,
642 				      &heartbeat_smi_msg,
643 				      &heartbeat_recv_msg,
644 				      1);
645 	if (rv) {
646 		mutex_unlock(&heartbeat_lock);
647 		printk(KERN_WARNING PFX "heartbeat failure: %d\n",
648 		       rv);
649 		return rv;
650 	}
651 
652 	/* Wait for the heartbeat to be sent. */
653 	wait_for_completion(&heartbeat_wait);
654 
655 	if (heartbeat_recv_msg.msg.data[0] != 0) {
656 		/*
657 		 * Got an error in the heartbeat response.  It was already
658 		 * reported in ipmi_wdog_msg_handler, but we should return
659 		 * an error here.
660 		 */
661 		rv = -EINVAL;
662 	}
663 
664 	mutex_unlock(&heartbeat_lock);
665 
666 	return rv;
667 }
668 
669 static struct watchdog_info ident = {
670 	.options	= 0,	/* WDIOF_SETTIMEOUT, */
671 	.firmware_version = 1,
672 	.identity	= "IPMI"
673 };
674 
ipmi_ioctl(struct file * file,unsigned int cmd,unsigned long arg)675 static int ipmi_ioctl(struct file *file,
676 		      unsigned int cmd, unsigned long arg)
677 {
678 	void __user *argp = (void __user *)arg;
679 	int i;
680 	int val;
681 
682 	switch (cmd) {
683 	case WDIOC_GETSUPPORT:
684 		i = copy_to_user(argp, &ident, sizeof(ident));
685 		return i ? -EFAULT : 0;
686 
687 	case WDIOC_SETTIMEOUT:
688 		i = copy_from_user(&val, argp, sizeof(int));
689 		if (i)
690 			return -EFAULT;
691 		timeout = val;
692 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
693 
694 	case WDIOC_GETTIMEOUT:
695 		i = copy_to_user(argp, &timeout, sizeof(timeout));
696 		if (i)
697 			return -EFAULT;
698 		return 0;
699 
700 	case WDIOC_SET_PRETIMEOUT:
701 	case WDIOC_SETPRETIMEOUT:
702 		i = copy_from_user(&val, argp, sizeof(int));
703 		if (i)
704 			return -EFAULT;
705 		pretimeout = val;
706 		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
707 
708 	case WDIOC_GET_PRETIMEOUT:
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_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(&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(&ipmi_read_lock);
816 			schedule();
817 			spin_lock(&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(&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 nonseekable_open(ino, filep);
855 
856 	default:
857 		return (-ENODEV);
858 	}
859 }
860 
ipmi_poll(struct file * file,poll_table * wait)861 static unsigned int ipmi_poll(struct file *file, poll_table *wait)
862 {
863 	unsigned int mask = 0;
864 
865 	poll_wait(file, &read_q, wait);
866 
867 	spin_lock(&ipmi_read_lock);
868 	if (data_to_read)
869 		mask |= (POLLIN | POLLRDNORM);
870 	spin_unlock(&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 			ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
889 			ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
890 		} else {
891 			printk(KERN_CRIT PFX
892 			       "Unexpected close, not stopping watchdog!\n");
893 			ipmi_heartbeat();
894 		}
895 		clear_bit(0, &ipmi_wdog_open);
896 	}
897 
898 	expect_close = 0;
899 
900 	return 0;
901 }
902 
903 static const struct file_operations ipmi_wdog_fops = {
904 	.owner   = THIS_MODULE,
905 	.read    = ipmi_read,
906 	.poll    = ipmi_poll,
907 	.write   = ipmi_write,
908 	.unlocked_ioctl = ipmi_unlocked_ioctl,
909 	.open    = ipmi_open,
910 	.release = ipmi_close,
911 	.fasync  = ipmi_fasync,
912 	.llseek  = no_llseek,
913 };
914 
915 static struct miscdevice ipmi_wdog_miscdev = {
916 	.minor		= WATCHDOG_MINOR,
917 	.name		= "watchdog",
918 	.fops		= &ipmi_wdog_fops
919 };
920 
ipmi_wdog_msg_handler(struct ipmi_recv_msg * msg,void * handler_data)921 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
922 				  void                 *handler_data)
923 {
924 	if (msg->msg.data[0] != 0) {
925 		printk(KERN_ERR PFX "response: Error %x on cmd %x\n",
926 		       msg->msg.data[0],
927 		       msg->msg.cmd);
928 	}
929 
930 	ipmi_free_recv_msg(msg);
931 }
932 
ipmi_wdog_pretimeout_handler(void * handler_data)933 static void ipmi_wdog_pretimeout_handler(void *handler_data)
934 {
935 	if (preaction_val != WDOG_PRETIMEOUT_NONE) {
936 		if (preop_val == WDOG_PREOP_PANIC) {
937 			if (atomic_inc_and_test(&preop_panic_excl))
938 				panic("Watchdog pre-timeout");
939 		} else if (preop_val == WDOG_PREOP_GIVE_DATA) {
940 			spin_lock(&ipmi_read_lock);
941 			data_to_read = 1;
942 			wake_up_interruptible(&read_q);
943 			kill_fasync(&fasync_q, SIGIO, POLL_IN);
944 
945 			spin_unlock(&ipmi_read_lock);
946 		}
947 	}
948 
949 	/*
950 	 * On some machines, the heartbeat will give an error and not
951 	 * work unless we re-enable the timer.  So do so.
952 	 */
953 	pretimeout_since_last_heartbeat = 1;
954 }
955 
956 static struct ipmi_user_hndl ipmi_hndlrs = {
957 	.ipmi_recv_hndl           = ipmi_wdog_msg_handler,
958 	.ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler
959 };
960 
ipmi_register_watchdog(int ipmi_intf)961 static void ipmi_register_watchdog(int ipmi_intf)
962 {
963 	int rv = -EBUSY;
964 
965 	if (watchdog_user)
966 		goto out;
967 
968 	if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
969 		goto out;
970 
971 	watchdog_ifnum = ipmi_intf;
972 
973 	rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
974 	if (rv < 0) {
975 		printk(KERN_CRIT PFX "Unable to register with ipmi\n");
976 		goto out;
977 	}
978 
979 	ipmi_get_version(watchdog_user,
980 			 &ipmi_version_major,
981 			 &ipmi_version_minor);
982 
983 	rv = misc_register(&ipmi_wdog_miscdev);
984 	if (rv < 0) {
985 		ipmi_destroy_user(watchdog_user);
986 		watchdog_user = NULL;
987 		printk(KERN_CRIT PFX "Unable to register misc device\n");
988 	}
989 
990 #ifdef HAVE_DIE_NMI
991 	if (nmi_handler_registered) {
992 		int old_pretimeout = pretimeout;
993 		int old_timeout = timeout;
994 		int old_preop_val = preop_val;
995 
996 		/*
997 		 * Set the pretimeout to go off in a second and give
998 		 * ourselves plenty of time to stop the timer.
999 		 */
1000 		ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1001 		preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
1002 		pretimeout = 99;
1003 		timeout = 100;
1004 
1005 		testing_nmi = 1;
1006 
1007 		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1008 		if (rv) {
1009 			printk(KERN_WARNING PFX "Error starting timer to"
1010 			       " test NMI: 0x%x.  The NMI pretimeout will"
1011 			       " likely not work\n", rv);
1012 			rv = 0;
1013 			goto out_restore;
1014 		}
1015 
1016 		msleep(1500);
1017 
1018 		if (testing_nmi != 2) {
1019 			printk(KERN_WARNING PFX "IPMI NMI didn't seem to"
1020 			       " occur.  The NMI pretimeout will"
1021 			       " likely not work\n");
1022 		}
1023  out_restore:
1024 		testing_nmi = 0;
1025 		preop_val = old_preop_val;
1026 		pretimeout = old_pretimeout;
1027 		timeout = old_timeout;
1028 	}
1029 #endif
1030 
1031  out:
1032 	if ((start_now) && (rv == 0)) {
1033 		/* Run from startup, so start the timer now. */
1034 		start_now = 0; /* Disable this function after first startup. */
1035 		ipmi_watchdog_state = action_val;
1036 		ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1037 		printk(KERN_INFO PFX "Starting now!\n");
1038 	} else {
1039 		/* Stop the timer now. */
1040 		ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1041 		ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1042 	}
1043 }
1044 
ipmi_unregister_watchdog(int ipmi_intf)1045 static void ipmi_unregister_watchdog(int ipmi_intf)
1046 {
1047 	int rv;
1048 
1049 	if (!watchdog_user)
1050 		goto out;
1051 
1052 	if (watchdog_ifnum != ipmi_intf)
1053 		goto out;
1054 
1055 	/* Make sure no one can call us any more. */
1056 	misc_deregister(&ipmi_wdog_miscdev);
1057 
1058 	/*
1059 	 * Wait to make sure the message makes it out.  The lower layer has
1060 	 * pointers to our buffers, we want to make sure they are done before
1061 	 * we release our memory.
1062 	 */
1063 	while (atomic_read(&set_timeout_tofree))
1064 		schedule_timeout_uninterruptible(1);
1065 
1066 	/* Disconnect from IPMI. */
1067 	rv = ipmi_destroy_user(watchdog_user);
1068 	if (rv) {
1069 		printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
1070 		       rv);
1071 	}
1072 	watchdog_user = NULL;
1073 
1074  out:
1075 	return;
1076 }
1077 
1078 #ifdef HAVE_DIE_NMI
1079 static int
ipmi_nmi(struct notifier_block * self,unsigned long val,void * data)1080 ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
1081 {
1082 	struct die_args *args = data;
1083 
1084 	if (val != DIE_NMIUNKNOWN)
1085 		return NOTIFY_OK;
1086 
1087 	/* Hack, if it's a memory or I/O error, ignore it. */
1088 	if (args->err & 0xc0)
1089 		return NOTIFY_OK;
1090 
1091 	/*
1092 	 * If we get here, it's an NMI that's not a memory or I/O
1093 	 * error.  We can't truly tell if it's from IPMI or not
1094 	 * without sending a message, and sending a message is almost
1095 	 * impossible because of locking.
1096 	 */
1097 
1098 	if (testing_nmi) {
1099 		testing_nmi = 2;
1100 		return NOTIFY_STOP;
1101 	}
1102 
1103 	/* If we are not expecting a timeout, ignore it. */
1104 	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1105 		return NOTIFY_OK;
1106 
1107 	if (preaction_val != WDOG_PRETIMEOUT_NMI)
1108 		return NOTIFY_OK;
1109 
1110 	/*
1111 	 * If no one else handled the NMI, we assume it was the IPMI
1112 	 * watchdog.
1113 	 */
1114 	if (preop_val == WDOG_PREOP_PANIC) {
1115 		/* On some machines, the heartbeat will give
1116 		   an error and not work unless we re-enable
1117 		   the timer.   So do so. */
1118 		pretimeout_since_last_heartbeat = 1;
1119 		if (atomic_inc_and_test(&preop_panic_excl))
1120 			panic(PFX "pre-timeout");
1121 	}
1122 
1123 	return NOTIFY_STOP;
1124 }
1125 
1126 static struct notifier_block ipmi_nmi_handler = {
1127 	.notifier_call = ipmi_nmi
1128 };
1129 #endif
1130 
wdog_reboot_handler(struct notifier_block * this,unsigned long code,void * unused)1131 static int wdog_reboot_handler(struct notifier_block *this,
1132 			       unsigned long         code,
1133 			       void                  *unused)
1134 {
1135 	static int reboot_event_handled;
1136 
1137 	if ((watchdog_user) && (!reboot_event_handled)) {
1138 		/* Make sure we only do this once. */
1139 		reboot_event_handled = 1;
1140 
1141 		if (code == SYS_POWER_OFF || code == SYS_HALT) {
1142 			/* Disable the WDT if we are shutting down. */
1143 			ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1144 			panic_halt_ipmi_set_timeout();
1145 		} else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1146 			/* Set a long timer to let the reboot happens, but
1147 			   reboot if it hangs, but only if the watchdog
1148 			   timer was already running. */
1149 			timeout = 120;
1150 			pretimeout = 0;
1151 			ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1152 			panic_halt_ipmi_set_timeout();
1153 		}
1154 	}
1155 	return NOTIFY_OK;
1156 }
1157 
1158 static struct notifier_block wdog_reboot_notifier = {
1159 	.notifier_call	= wdog_reboot_handler,
1160 	.next		= NULL,
1161 	.priority	= 0
1162 };
1163 
wdog_panic_handler(struct notifier_block * this,unsigned long event,void * unused)1164 static int wdog_panic_handler(struct notifier_block *this,
1165 			      unsigned long         event,
1166 			      void                  *unused)
1167 {
1168 	static int panic_event_handled;
1169 
1170 	/* On a panic, if we have a panic timeout, make sure to extend
1171 	   the watchdog timer to a reasonable value to complete the
1172 	   panic, if the watchdog timer is running.  Plus the
1173 	   pretimeout is meaningless at panic time. */
1174 	if (watchdog_user && !panic_event_handled &&
1175 	    ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1176 		/* Make sure we do this only once. */
1177 		panic_event_handled = 1;
1178 
1179 		timeout = 255;
1180 		pretimeout = 0;
1181 		panic_halt_ipmi_set_timeout();
1182 	}
1183 
1184 	return NOTIFY_OK;
1185 }
1186 
1187 static struct notifier_block wdog_panic_notifier = {
1188 	.notifier_call	= wdog_panic_handler,
1189 	.next		= NULL,
1190 	.priority	= 150	/* priority: INT_MAX >= x >= 0 */
1191 };
1192 
1193 
ipmi_new_smi(int if_num,struct device * device)1194 static void ipmi_new_smi(int if_num, struct device *device)
1195 {
1196 	ipmi_register_watchdog(if_num);
1197 }
1198 
ipmi_smi_gone(int if_num)1199 static void ipmi_smi_gone(int if_num)
1200 {
1201 	ipmi_unregister_watchdog(if_num);
1202 }
1203 
1204 static struct ipmi_smi_watcher smi_watcher = {
1205 	.owner    = THIS_MODULE,
1206 	.new_smi  = ipmi_new_smi,
1207 	.smi_gone = ipmi_smi_gone
1208 };
1209 
action_op(const char * inval,char * outval)1210 static int action_op(const char *inval, char *outval)
1211 {
1212 	if (outval)
1213 		strcpy(outval, action);
1214 
1215 	if (!inval)
1216 		return 0;
1217 
1218 	if (strcmp(inval, "reset") == 0)
1219 		action_val = WDOG_TIMEOUT_RESET;
1220 	else if (strcmp(inval, "none") == 0)
1221 		action_val = WDOG_TIMEOUT_NONE;
1222 	else if (strcmp(inval, "power_cycle") == 0)
1223 		action_val = WDOG_TIMEOUT_POWER_CYCLE;
1224 	else if (strcmp(inval, "power_off") == 0)
1225 		action_val = WDOG_TIMEOUT_POWER_DOWN;
1226 	else
1227 		return -EINVAL;
1228 	strcpy(action, inval);
1229 	return 0;
1230 }
1231 
preaction_op(const char * inval,char * outval)1232 static int preaction_op(const char *inval, char *outval)
1233 {
1234 	if (outval)
1235 		strcpy(outval, preaction);
1236 
1237 	if (!inval)
1238 		return 0;
1239 
1240 	if (strcmp(inval, "pre_none") == 0)
1241 		preaction_val = WDOG_PRETIMEOUT_NONE;
1242 	else if (strcmp(inval, "pre_smi") == 0)
1243 		preaction_val = WDOG_PRETIMEOUT_SMI;
1244 #ifdef HAVE_DIE_NMI
1245 	else if (strcmp(inval, "pre_nmi") == 0)
1246 		preaction_val = WDOG_PRETIMEOUT_NMI;
1247 #endif
1248 	else if (strcmp(inval, "pre_int") == 0)
1249 		preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1250 	else
1251 		return -EINVAL;
1252 	strcpy(preaction, inval);
1253 	return 0;
1254 }
1255 
preop_op(const char * inval,char * outval)1256 static int preop_op(const char *inval, char *outval)
1257 {
1258 	if (outval)
1259 		strcpy(outval, preop);
1260 
1261 	if (!inval)
1262 		return 0;
1263 
1264 	if (strcmp(inval, "preop_none") == 0)
1265 		preop_val = WDOG_PREOP_NONE;
1266 	else if (strcmp(inval, "preop_panic") == 0)
1267 		preop_val = WDOG_PREOP_PANIC;
1268 	else if (strcmp(inval, "preop_give_data") == 0)
1269 		preop_val = WDOG_PREOP_GIVE_DATA;
1270 	else
1271 		return -EINVAL;
1272 	strcpy(preop, inval);
1273 	return 0;
1274 }
1275 
check_parms(void)1276 static void check_parms(void)
1277 {
1278 #ifdef HAVE_DIE_NMI
1279 	int do_nmi = 0;
1280 	int rv;
1281 
1282 	if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1283 		do_nmi = 1;
1284 		if (preop_val == WDOG_PREOP_GIVE_DATA) {
1285 			printk(KERN_WARNING PFX "Pretimeout op is to give data"
1286 			       " but NMI pretimeout is enabled, setting"
1287 			       " pretimeout op to none\n");
1288 			preop_op("preop_none", NULL);
1289 			do_nmi = 0;
1290 		}
1291 	}
1292 	if (do_nmi && !nmi_handler_registered) {
1293 		rv = register_die_notifier(&ipmi_nmi_handler);
1294 		if (rv) {
1295 			printk(KERN_WARNING PFX
1296 			       "Can't register nmi handler\n");
1297 			return;
1298 		} else
1299 			nmi_handler_registered = 1;
1300 	} else if (!do_nmi && nmi_handler_registered) {
1301 		unregister_die_notifier(&ipmi_nmi_handler);
1302 		nmi_handler_registered = 0;
1303 	}
1304 #endif
1305 }
1306 
ipmi_wdog_init(void)1307 static int __init ipmi_wdog_init(void)
1308 {
1309 	int rv;
1310 
1311 	if (action_op(action, NULL)) {
1312 		action_op("reset", NULL);
1313 		printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
1314 		       " reset\n", action);
1315 	}
1316 
1317 	if (preaction_op(preaction, NULL)) {
1318 		preaction_op("pre_none", NULL);
1319 		printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
1320 		       " none\n", preaction);
1321 	}
1322 
1323 	if (preop_op(preop, NULL)) {
1324 		preop_op("preop_none", NULL);
1325 		printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
1326 		       " none\n", preop);
1327 	}
1328 
1329 	check_parms();
1330 
1331 	register_reboot_notifier(&wdog_reboot_notifier);
1332 	atomic_notifier_chain_register(&panic_notifier_list,
1333 			&wdog_panic_notifier);
1334 
1335 	rv = ipmi_smi_watcher_register(&smi_watcher);
1336 	if (rv) {
1337 #ifdef HAVE_DIE_NMI
1338 		if (nmi_handler_registered)
1339 			unregister_die_notifier(&ipmi_nmi_handler);
1340 #endif
1341 		atomic_notifier_chain_unregister(&panic_notifier_list,
1342 						 &wdog_panic_notifier);
1343 		unregister_reboot_notifier(&wdog_reboot_notifier);
1344 		printk(KERN_WARNING PFX "can't register smi watcher\n");
1345 		return rv;
1346 	}
1347 
1348 	printk(KERN_INFO PFX "driver initialized\n");
1349 
1350 	return 0;
1351 }
1352 
ipmi_wdog_exit(void)1353 static void __exit ipmi_wdog_exit(void)
1354 {
1355 	ipmi_smi_watcher_unregister(&smi_watcher);
1356 	ipmi_unregister_watchdog(watchdog_ifnum);
1357 
1358 #ifdef HAVE_DIE_NMI
1359 	if (nmi_handler_registered)
1360 		unregister_die_notifier(&ipmi_nmi_handler);
1361 #endif
1362 
1363 	atomic_notifier_chain_unregister(&panic_notifier_list,
1364 					 &wdog_panic_notifier);
1365 	unregister_reboot_notifier(&wdog_reboot_notifier);
1366 }
1367 module_exit(ipmi_wdog_exit);
1368 module_init(ipmi_wdog_init);
1369 MODULE_LICENSE("GPL");
1370 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1371 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");
1372