1
2
3
4
5
6
7
8
9
10
11
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
43
44
45
46
47
48
49
50#include <asm/kdebug.h>
51#include <asm/nmi.h>
52#define HAVE_DIE_NMI
53#endif
54
55
56
57
58
59
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
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
81#define WDOG_PREOP_NONE 0
82#define WDOG_PREOP_PANIC 1
83
84#define WDOG_PREOP_GIVE_DATA 2
85
86
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
97
98
99
100
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
109
110
111
112
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
125static DEFINE_MUTEX(ipmi_watchdog_mutex);
126static bool nowayout = WATCHDOG_NOWAYOUT;
127
128static struct ipmi_user *watchdog_user;
129static int watchdog_ifnum;
130
131
132static int timeout = 10;
133
134
135static int pretimeout;
136
137
138static int panic_wdt_timeout = 255;
139
140
141static unsigned char action_val = WDOG_TIMEOUT_RESET;
142
143static char action[16] = "reset";
144
145static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
146
147static char preaction[16] = "pre_none";
148
149static unsigned char preop_val = WDOG_PREOP_NONE;
150
151static char preop[16] = "preop_none";
152static DEFINE_SPINLOCK(ipmi_read_lock);
153static char data_to_read;
154static DECLARE_WAIT_QUEUE_HEAD(read_q);
155static struct fasync_struct *fasync_q;
156static atomic_t pretimeout_since_last_heartbeat;
157static char expect_close;
158
159static int ifnum_to_use = -1;
160
161
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
166static int ipmi_set_timeout(int do_heartbeat);
167static void ipmi_register_watchdog(int ipmi_intf);
168static void ipmi_unregister_watchdog(int ipmi_intf);
169
170
171
172
173
174static int start_now;
175
176static 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
195static 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
201typedef int (*action_fn)(const char *intval, char *outval);
202
203static int action_op(const char *inval, char *outval);
204static int preaction_op(const char *inval, char *outval);
205static int preop_op(const char *inval, char *outval);
206static void check_parms(void);
207
208static 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
232static 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
249static 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
262static 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
269static const struct kernel_param_ops param_ops_str = {
270 .set = set_param_str,
271 .get = get_param_str,
272};
273
274module_param(ifnum_to_use, wdog_ifnum, 0644);
275MODULE_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
279module_param(timeout, timeout, 0644);
280MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
281
282module_param(pretimeout, timeout, 0644);
283MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
284
285module_param(panic_wdt_timeout, timeout, 0644);
286MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds.");
287
288module_param_cb(action, ¶m_ops_str, action_op, 0644);
289MODULE_PARM_DESC(action, "Timeout action. One of: "
290 "reset, none, power_cycle, power_off.");
291
292module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644);
293MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "
294 "pre_none, pre_smi, pre_nmi, pre_int.");
295
296module_param_cb(preop, ¶m_ops_str, preop_op, 0644);
297MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "
298 "preop_none, preop_panic, preop_give_data.");
299
300module_param(start_now, int, 0444);
301MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
302 "soon as the driver is loaded.");
303
304module_param(nowayout, bool, 0644);
305MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
306 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
307
308
309static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
310
311
312static unsigned long ipmi_wdog_open;
313
314
315
316
317
318
319
320static int ipmi_start_timer_on_heartbeat;
321
322
323static unsigned char ipmi_version_major;
324static unsigned char ipmi_version_minor;
325
326
327static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
328
329#ifdef HAVE_DIE_NMI
330static int testing_nmi;
331static int nmi_handler_registered;
332#endif
333
334static int __ipmi_heartbeat(void);
335
336
337
338
339
340
341static atomic_t msg_tofree = ATOMIC_INIT(0);
342static DECLARE_COMPLETION(msg_wait);
343static void msg_free_smi(struct ipmi_smi_msg *msg)
344{
345 if (atomic_dec_and_test(&msg_tofree))
346 complete(&msg_wait);
347}
348static void msg_free_recv(struct ipmi_recv_msg *msg)
349{
350 if (atomic_dec_and_test(&msg_tofree))
351 complete(&msg_wait);
352}
353static struct ipmi_smi_msg smi_msg = {
354 .done = msg_free_smi
355};
356static struct ipmi_recv_msg recv_msg = {
357 .done = msg_free_recv
358};
359
360static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg,
361 struct ipmi_recv_msg *recv_msg,
362 int *send_heartbeat_now)
363{
364 struct kernel_ipmi_msg msg;
365 unsigned char data[6];
366 int rv;
367 struct ipmi_system_interface_addr addr;
368 int hbnow = 0;
369
370
371 data[0] = 0;
372 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
373
374 if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
375 if ((ipmi_version_major > 1) ||
376 ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
377
378 data[0] |= WDOG_DONT_STOP_ON_SET;
379 } else {
380
381
382
383
384 hbnow = 1;
385 }
386 }
387
388 data[1] = 0;
389 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
390 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
391 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
392 data[2] = pretimeout;
393 } else {
394 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
395 data[2] = 0;
396 }
397 data[3] = 0;
398 WDOG_SET_TIMEOUT(data[4], data[5], timeout);
399
400 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
401 addr.channel = IPMI_BMC_CHANNEL;
402 addr.lun = 0;
403
404 msg.netfn = 0x06;
405 msg.cmd = IPMI_WDOG_SET_TIMER;
406 msg.data = data;
407 msg.data_len = sizeof(data);
408 rv = ipmi_request_supply_msgs(watchdog_user,
409 (struct ipmi_addr *) &addr,
410 0,
411 &msg,
412 NULL,
413 smi_msg,
414 recv_msg,
415 1);
416 if (rv)
417 pr_warn("set timeout error: %d\n", rv);
418 else if (send_heartbeat_now)
419 *send_heartbeat_now = hbnow;
420
421 return rv;
422}
423
424static int _ipmi_set_timeout(int do_heartbeat)
425{
426 int send_heartbeat_now;
427 int rv;
428
429 if (!watchdog_user)
430 return -ENODEV;
431
432 atomic_set(&msg_tofree, 2);
433
434 rv = __ipmi_set_timeout(&smi_msg,
435 &recv_msg,
436 &send_heartbeat_now);
437 if (rv)
438 return rv;
439
440 wait_for_completion(&msg_wait);
441
442 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
443 || ((send_heartbeat_now)
444 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
445 rv = __ipmi_heartbeat();
446
447 return rv;
448}
449
450static int ipmi_set_timeout(int do_heartbeat)
451{
452 int rv;
453
454 mutex_lock(&ipmi_watchdog_mutex);
455 rv = _ipmi_set_timeout(do_heartbeat);
456 mutex_unlock(&ipmi_watchdog_mutex);
457
458 return rv;
459}
460
461static atomic_t panic_done_count = ATOMIC_INIT(0);
462
463static void panic_smi_free(struct ipmi_smi_msg *msg)
464{
465 atomic_dec(&panic_done_count);
466}
467static void panic_recv_free(struct ipmi_recv_msg *msg)
468{
469 atomic_dec(&panic_done_count);
470}
471
472static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
473 .done = panic_smi_free
474};
475static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
476 .done = panic_recv_free
477};
478
479static void panic_halt_ipmi_heartbeat(void)
480{
481 struct kernel_ipmi_msg msg;
482 struct ipmi_system_interface_addr addr;
483 int rv;
484
485
486
487
488
489 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
490 return;
491
492 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
493 addr.channel = IPMI_BMC_CHANNEL;
494 addr.lun = 0;
495
496 msg.netfn = 0x06;
497 msg.cmd = IPMI_WDOG_RESET_TIMER;
498 msg.data = NULL;
499 msg.data_len = 0;
500 atomic_inc(&panic_done_count);
501 rv = ipmi_request_supply_msgs(watchdog_user,
502 (struct ipmi_addr *) &addr,
503 0,
504 &msg,
505 NULL,
506 &panic_halt_heartbeat_smi_msg,
507 &panic_halt_heartbeat_recv_msg,
508 1);
509 if (rv)
510 atomic_dec(&panic_done_count);
511}
512
513static struct ipmi_smi_msg panic_halt_smi_msg = {
514 .done = panic_smi_free
515};
516static struct ipmi_recv_msg panic_halt_recv_msg = {
517 .done = panic_recv_free
518};
519
520
521
522
523
524
525
526static void panic_halt_ipmi_set_timeout(void)
527{
528 int send_heartbeat_now;
529 int rv;
530
531
532 while (atomic_read(&panic_done_count) != 0)
533 ipmi_poll_interface(watchdog_user);
534 atomic_inc(&panic_done_count);
535 rv = __ipmi_set_timeout(&panic_halt_smi_msg,
536 &panic_halt_recv_msg,
537 &send_heartbeat_now);
538 if (rv) {
539 atomic_dec(&panic_done_count);
540 pr_warn("Unable to extend the watchdog timeout\n");
541 } else {
542 if (send_heartbeat_now)
543 panic_halt_ipmi_heartbeat();
544 }
545 while (atomic_read(&panic_done_count) != 0)
546 ipmi_poll_interface(watchdog_user);
547}
548
549static int __ipmi_heartbeat(void)
550{
551 struct kernel_ipmi_msg msg;
552 int rv;
553 struct ipmi_system_interface_addr addr;
554 int timeout_retries = 0;
555
556restart:
557
558
559
560
561 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
562 return 0;
563
564 atomic_set(&msg_tofree, 2);
565
566 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
567 addr.channel = IPMI_BMC_CHANNEL;
568 addr.lun = 0;
569
570 msg.netfn = 0x06;
571 msg.cmd = IPMI_WDOG_RESET_TIMER;
572 msg.data = NULL;
573 msg.data_len = 0;
574 rv = ipmi_request_supply_msgs(watchdog_user,
575 (struct ipmi_addr *) &addr,
576 0,
577 &msg,
578 NULL,
579 &smi_msg,
580 &recv_msg,
581 1);
582 if (rv) {
583 pr_warn("heartbeat send failure: %d\n", rv);
584 return rv;
585 }
586
587
588 wait_for_completion(&msg_wait);
589
590 if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) {
591 timeout_retries++;
592 if (timeout_retries > 3) {
593 pr_err("Unable to restore the IPMI watchdog's settings, giving up\n");
594 rv = -EIO;
595 goto out;
596 }
597
598
599
600
601
602
603
604
605
606 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
607 if (rv) {
608 pr_err("Unable to send the command to set the watchdog's settings, giving up\n");
609 goto out;
610 }
611
612
613 goto restart;
614 } else if (recv_msg.msg.data[0] != 0) {
615
616
617
618
619
620 rv = -EINVAL;
621 }
622
623out:
624 return rv;
625}
626
627static int _ipmi_heartbeat(void)
628{
629 int rv;
630
631 if (!watchdog_user)
632 return -ENODEV;
633
634 if (ipmi_start_timer_on_heartbeat) {
635 ipmi_start_timer_on_heartbeat = 0;
636 ipmi_watchdog_state = action_val;
637 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
638 } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) {
639
640
641
642
643
644
645 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
646 } else {
647 rv = __ipmi_heartbeat();
648 }
649
650 return rv;
651}
652
653static int ipmi_heartbeat(void)
654{
655 int rv;
656
657 mutex_lock(&ipmi_watchdog_mutex);
658 rv = _ipmi_heartbeat();
659 mutex_unlock(&ipmi_watchdog_mutex);
660
661 return rv;
662}
663
664static struct watchdog_info ident = {
665 .options = 0,
666 .firmware_version = 1,
667 .identity = "IPMI"
668};
669
670static int ipmi_ioctl(struct file *file,
671 unsigned int cmd, unsigned long arg)
672{
673 void __user *argp = (void __user *)arg;
674 int i;
675 int val;
676
677 switch (cmd) {
678 case WDIOC_GETSUPPORT:
679 i = copy_to_user(argp, &ident, sizeof(ident));
680 return i ? -EFAULT : 0;
681
682 case WDIOC_SETTIMEOUT:
683 i = copy_from_user(&val, argp, sizeof(int));
684 if (i)
685 return -EFAULT;
686 timeout = val;
687 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
688
689 case WDIOC_GETTIMEOUT:
690 i = copy_to_user(argp, &timeout, sizeof(timeout));
691 if (i)
692 return -EFAULT;
693 return 0;
694
695 case WDIOC_SETPRETIMEOUT:
696 i = copy_from_user(&val, argp, sizeof(int));
697 if (i)
698 return -EFAULT;
699 pretimeout = val;
700 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
701
702 case WDIOC_GETPRETIMEOUT:
703 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
704 if (i)
705 return -EFAULT;
706 return 0;
707
708 case WDIOC_KEEPALIVE:
709 return _ipmi_heartbeat();
710
711 case WDIOC_SETOPTIONS:
712 i = copy_from_user(&val, argp, sizeof(int));
713 if (i)
714 return -EFAULT;
715 if (val & WDIOS_DISABLECARD) {
716 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
717 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
718 ipmi_start_timer_on_heartbeat = 0;
719 }
720
721 if (val & WDIOS_ENABLECARD) {
722 ipmi_watchdog_state = action_val;
723 _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
724 }
725 return 0;
726
727 case WDIOC_GETSTATUS:
728 val = 0;
729 i = copy_to_user(argp, &val, sizeof(val));
730 if (i)
731 return -EFAULT;
732 return 0;
733
734 default:
735 return -ENOIOCTLCMD;
736 }
737}
738
739static long ipmi_unlocked_ioctl(struct file *file,
740 unsigned int cmd,
741 unsigned long arg)
742{
743 int ret;
744
745 mutex_lock(&ipmi_watchdog_mutex);
746 ret = ipmi_ioctl(file, cmd, arg);
747 mutex_unlock(&ipmi_watchdog_mutex);
748
749 return ret;
750}
751
752static ssize_t ipmi_write(struct file *file,
753 const char __user *buf,
754 size_t len,
755 loff_t *ppos)
756{
757 int rv;
758
759 if (len) {
760 if (!nowayout) {
761 size_t i;
762
763
764 expect_close = 0;
765
766 for (i = 0; i != len; i++) {
767 char c;
768
769 if (get_user(c, buf + i))
770 return -EFAULT;
771 if (c == 'V')
772 expect_close = 42;
773 }
774 }
775 rv = ipmi_heartbeat();
776 if (rv)
777 return rv;
778 }
779 return len;
780}
781
782static ssize_t ipmi_read(struct file *file,
783 char __user *buf,
784 size_t count,
785 loff_t *ppos)
786{
787 int rv = 0;
788 wait_queue_entry_t wait;
789
790 if (count <= 0)
791 return 0;
792
793
794
795
796
797 spin_lock_irq(&ipmi_read_lock);
798 if (!data_to_read) {
799 if (file->f_flags & O_NONBLOCK) {
800 rv = -EAGAIN;
801 goto out;
802 }
803
804 init_waitqueue_entry(&wait, current);
805 add_wait_queue(&read_q, &wait);
806 while (!data_to_read) {
807 set_current_state(TASK_INTERRUPTIBLE);
808 spin_unlock_irq(&ipmi_read_lock);
809 schedule();
810 spin_lock_irq(&ipmi_read_lock);
811 }
812 remove_wait_queue(&read_q, &wait);
813
814 if (signal_pending(current)) {
815 rv = -ERESTARTSYS;
816 goto out;
817 }
818 }
819 data_to_read = 0;
820
821 out:
822 spin_unlock_irq(&ipmi_read_lock);
823
824 if (rv == 0) {
825 if (copy_to_user(buf, &data_to_read, 1))
826 rv = -EFAULT;
827 else
828 rv = 1;
829 }
830
831 return rv;
832}
833
834static int ipmi_open(struct inode *ino, struct file *filep)
835{
836 switch (iminor(ino)) {
837 case WATCHDOG_MINOR:
838 if (test_and_set_bit(0, &ipmi_wdog_open))
839 return -EBUSY;
840
841
842
843
844
845
846 ipmi_start_timer_on_heartbeat = 1;
847 return stream_open(ino, filep);
848
849 default:
850 return (-ENODEV);
851 }
852}
853
854static __poll_t ipmi_poll(struct file *file, poll_table *wait)
855{
856 __poll_t mask = 0;
857
858 poll_wait(file, &read_q, wait);
859
860 spin_lock_irq(&ipmi_read_lock);
861 if (data_to_read)
862 mask |= (EPOLLIN | EPOLLRDNORM);
863 spin_unlock_irq(&ipmi_read_lock);
864
865 return mask;
866}
867
868static int ipmi_fasync(int fd, struct file *file, int on)
869{
870 int result;
871
872 result = fasync_helper(fd, file, on, &fasync_q);
873
874 return (result);
875}
876
877static int ipmi_close(struct inode *ino, struct file *filep)
878{
879 if (iminor(ino) == WATCHDOG_MINOR) {
880 if (expect_close == 42) {
881 mutex_lock(&ipmi_watchdog_mutex);
882 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
883 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
884 mutex_unlock(&ipmi_watchdog_mutex);
885 } else {
886 pr_crit("Unexpected close, not stopping watchdog!\n");
887 ipmi_heartbeat();
888 }
889 clear_bit(0, &ipmi_wdog_open);
890 }
891
892 expect_close = 0;
893
894 return 0;
895}
896
897static const struct file_operations ipmi_wdog_fops = {
898 .owner = THIS_MODULE,
899 .read = ipmi_read,
900 .poll = ipmi_poll,
901 .write = ipmi_write,
902 .unlocked_ioctl = ipmi_unlocked_ioctl,
903 .compat_ioctl = compat_ptr_ioctl,
904 .open = ipmi_open,
905 .release = ipmi_close,
906 .fasync = ipmi_fasync,
907 .llseek = no_llseek,
908};
909
910static struct miscdevice ipmi_wdog_miscdev = {
911 .minor = WATCHDOG_MINOR,
912 .name = "watchdog",
913 .fops = &ipmi_wdog_fops
914};
915
916static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
917 void *handler_data)
918{
919 if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
920 msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
921 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");
922 else if (msg->msg.data[0] != 0)
923 pr_err("response: Error %x on cmd %x\n",
924 msg->msg.data[0],
925 msg->msg.cmd);
926
927 ipmi_free_recv_msg(msg);
928}
929
930static void ipmi_wdog_pretimeout_handler(void *handler_data)
931{
932 if (preaction_val != WDOG_PRETIMEOUT_NONE) {
933 if (preop_val == WDOG_PREOP_PANIC) {
934 if (atomic_inc_and_test(&preop_panic_excl))
935 panic("Watchdog pre-timeout");
936 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
937 unsigned long flags;
938
939 spin_lock_irqsave(&ipmi_read_lock, flags);
940 data_to_read = 1;
941 wake_up_interruptible(&read_q);
942 kill_fasync(&fasync_q, SIGIO, POLL_IN);
943 spin_unlock_irqrestore(&ipmi_read_lock, flags);
944 }
945 }
946
947
948
949
950
951 atomic_set(&pretimeout_since_last_heartbeat, 1);
952}
953
954static void ipmi_wdog_panic_handler(void *user_data)
955{
956 static int panic_event_handled;
957
958
959
960
961
962
963
964 if (watchdog_user && !panic_event_handled &&
965 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
966
967 panic_event_handled = 1;
968
969 timeout = panic_wdt_timeout;
970 pretimeout = 0;
971 panic_halt_ipmi_set_timeout();
972 }
973}
974
975static const struct ipmi_user_hndl ipmi_hndlrs = {
976 .ipmi_recv_hndl = ipmi_wdog_msg_handler,
977 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler,
978 .ipmi_panic_handler = ipmi_wdog_panic_handler
979};
980
981static void ipmi_register_watchdog(int ipmi_intf)
982{
983 int rv = -EBUSY;
984
985 if (watchdog_user)
986 goto out;
987
988 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
989 goto out;
990
991 watchdog_ifnum = ipmi_intf;
992
993 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
994 if (rv < 0) {
995 pr_crit("Unable to register with ipmi\n");
996 goto out;
997 }
998
999 rv = ipmi_get_version(watchdog_user,
1000 &ipmi_version_major,
1001 &ipmi_version_minor);
1002 if (rv) {
1003 pr_warn("Unable to get IPMI version, assuming 1.0\n");
1004 ipmi_version_major = 1;
1005 ipmi_version_minor = 0;
1006 }
1007
1008 rv = misc_register(&ipmi_wdog_miscdev);
1009 if (rv < 0) {
1010 ipmi_destroy_user(watchdog_user);
1011 watchdog_user = NULL;
1012 pr_crit("Unable to register misc device\n");
1013 }
1014
1015#ifdef HAVE_DIE_NMI
1016 if (nmi_handler_registered) {
1017 int old_pretimeout = pretimeout;
1018 int old_timeout = timeout;
1019 int old_preop_val = preop_val;
1020
1021
1022
1023
1024
1025 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1026 preop_val = WDOG_PREOP_NONE;
1027 pretimeout = 99;
1028 timeout = 100;
1029
1030 testing_nmi = 1;
1031
1032 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1033 if (rv) {
1034 pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n",
1035 rv);
1036 rv = 0;
1037 goto out_restore;
1038 }
1039
1040 msleep(1500);
1041
1042 if (testing_nmi != 2) {
1043 pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n");
1044 }
1045 out_restore:
1046 testing_nmi = 0;
1047 preop_val = old_preop_val;
1048 pretimeout = old_pretimeout;
1049 timeout = old_timeout;
1050 }
1051#endif
1052
1053 out:
1054 if ((start_now) && (rv == 0)) {
1055
1056 start_now = 0;
1057 ipmi_watchdog_state = action_val;
1058 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1059 pr_info("Starting now!\n");
1060 } else {
1061
1062 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1063 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1064 }
1065}
1066
1067static void ipmi_unregister_watchdog(int ipmi_intf)
1068{
1069 int rv;
1070 struct ipmi_user *loc_user = watchdog_user;
1071
1072 if (!loc_user)
1073 return;
1074
1075 if (watchdog_ifnum != ipmi_intf)
1076 return;
1077
1078
1079 misc_deregister(&ipmi_wdog_miscdev);
1080
1081 watchdog_user = NULL;
1082
1083
1084
1085
1086
1087
1088 while (atomic_read(&msg_tofree))
1089 msg_free_smi(NULL);
1090
1091 mutex_lock(&ipmi_watchdog_mutex);
1092
1093
1094 rv = ipmi_destroy_user(loc_user);
1095 if (rv)
1096 pr_warn("error unlinking from IPMI: %d\n", rv);
1097
1098
1099 ipmi_start_timer_on_heartbeat = 1;
1100
1101 mutex_unlock(&ipmi_watchdog_mutex);
1102}
1103
1104#ifdef HAVE_DIE_NMI
1105static int
1106ipmi_nmi(unsigned int val, struct pt_regs *regs)
1107{
1108
1109
1110
1111
1112
1113
1114
1115 if (testing_nmi) {
1116 testing_nmi = 2;
1117 return NMI_HANDLED;
1118 }
1119
1120
1121 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1122 return NMI_DONE;
1123
1124 if (preaction_val != WDOG_PRETIMEOUT_NMI)
1125 return NMI_DONE;
1126
1127
1128
1129
1130
1131 if (preop_val == WDOG_PREOP_PANIC) {
1132
1133
1134
1135 atomic_set(&pretimeout_since_last_heartbeat, 1);
1136 if (atomic_inc_and_test(&preop_panic_excl))
1137 nmi_panic(regs, "pre-timeout");
1138 }
1139
1140 return NMI_HANDLED;
1141}
1142#endif
1143
1144static int wdog_reboot_handler(struct notifier_block *this,
1145 unsigned long code,
1146 void *unused)
1147{
1148 static int reboot_event_handled;
1149
1150 if ((watchdog_user) && (!reboot_event_handled)) {
1151
1152 reboot_event_handled = 1;
1153
1154 if (code == SYS_POWER_OFF || code == SYS_HALT) {
1155
1156 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1157 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1158 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1159
1160
1161
1162 if (timeout < 120)
1163 timeout = 120;
1164 pretimeout = 0;
1165 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1166 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1167 }
1168 }
1169 return NOTIFY_OK;
1170}
1171
1172static struct notifier_block wdog_reboot_notifier = {
1173 .notifier_call = wdog_reboot_handler,
1174 .next = NULL,
1175 .priority = 0
1176};
1177
1178static void ipmi_new_smi(int if_num, struct device *device)
1179{
1180 ipmi_register_watchdog(if_num);
1181}
1182
1183static void ipmi_smi_gone(int if_num)
1184{
1185 ipmi_unregister_watchdog(if_num);
1186}
1187
1188static struct ipmi_smi_watcher smi_watcher = {
1189 .owner = THIS_MODULE,
1190 .new_smi = ipmi_new_smi,
1191 .smi_gone = ipmi_smi_gone
1192};
1193
1194static int action_op(const char *inval, char *outval)
1195{
1196 if (outval)
1197 strcpy(outval, action);
1198
1199 if (!inval)
1200 return 0;
1201
1202 if (strcmp(inval, "reset") == 0)
1203 action_val = WDOG_TIMEOUT_RESET;
1204 else if (strcmp(inval, "none") == 0)
1205 action_val = WDOG_TIMEOUT_NONE;
1206 else if (strcmp(inval, "power_cycle") == 0)
1207 action_val = WDOG_TIMEOUT_POWER_CYCLE;
1208 else if (strcmp(inval, "power_off") == 0)
1209 action_val = WDOG_TIMEOUT_POWER_DOWN;
1210 else
1211 return -EINVAL;
1212 strcpy(action, inval);
1213 return 0;
1214}
1215
1216static int preaction_op(const char *inval, char *outval)
1217{
1218 if (outval)
1219 strcpy(outval, preaction);
1220
1221 if (!inval)
1222 return 0;
1223
1224 if (strcmp(inval, "pre_none") == 0)
1225 preaction_val = WDOG_PRETIMEOUT_NONE;
1226 else if (strcmp(inval, "pre_smi") == 0)
1227 preaction_val = WDOG_PRETIMEOUT_SMI;
1228#ifdef HAVE_DIE_NMI
1229 else if (strcmp(inval, "pre_nmi") == 0)
1230 preaction_val = WDOG_PRETIMEOUT_NMI;
1231#endif
1232 else if (strcmp(inval, "pre_int") == 0)
1233 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1234 else
1235 return -EINVAL;
1236 strcpy(preaction, inval);
1237 return 0;
1238}
1239
1240static int preop_op(const char *inval, char *outval)
1241{
1242 if (outval)
1243 strcpy(outval, preop);
1244
1245 if (!inval)
1246 return 0;
1247
1248 if (strcmp(inval, "preop_none") == 0)
1249 preop_val = WDOG_PREOP_NONE;
1250 else if (strcmp(inval, "preop_panic") == 0)
1251 preop_val = WDOG_PREOP_PANIC;
1252 else if (strcmp(inval, "preop_give_data") == 0)
1253 preop_val = WDOG_PREOP_GIVE_DATA;
1254 else
1255 return -EINVAL;
1256 strcpy(preop, inval);
1257 return 0;
1258}
1259
1260static void check_parms(void)
1261{
1262#ifdef HAVE_DIE_NMI
1263 int do_nmi = 0;
1264 int rv;
1265
1266 if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1267 do_nmi = 1;
1268 if (preop_val == WDOG_PREOP_GIVE_DATA) {
1269 pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n");
1270 preop_op("preop_none", NULL);
1271 do_nmi = 0;
1272 }
1273 }
1274 if (do_nmi && !nmi_handler_registered) {
1275 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0,
1276 "ipmi");
1277 if (rv) {
1278 pr_warn("Can't register nmi handler\n");
1279 return;
1280 } else
1281 nmi_handler_registered = 1;
1282 } else if (!do_nmi && nmi_handler_registered) {
1283 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1284 nmi_handler_registered = 0;
1285 }
1286#endif
1287}
1288
1289static int __init ipmi_wdog_init(void)
1290{
1291 int rv;
1292
1293 if (action_op(action, NULL)) {
1294 action_op("reset", NULL);
1295 pr_info("Unknown action '%s', defaulting to reset\n", action);
1296 }
1297
1298 if (preaction_op(preaction, NULL)) {
1299 preaction_op("pre_none", NULL);
1300 pr_info("Unknown preaction '%s', defaulting to none\n",
1301 preaction);
1302 }
1303
1304 if (preop_op(preop, NULL)) {
1305 preop_op("preop_none", NULL);
1306 pr_info("Unknown preop '%s', defaulting to none\n", preop);
1307 }
1308
1309 check_parms();
1310
1311 register_reboot_notifier(&wdog_reboot_notifier);
1312
1313 rv = ipmi_smi_watcher_register(&smi_watcher);
1314 if (rv) {
1315#ifdef HAVE_DIE_NMI
1316 if (nmi_handler_registered)
1317 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1318#endif
1319 unregister_reboot_notifier(&wdog_reboot_notifier);
1320 pr_warn("can't register smi watcher\n");
1321 return rv;
1322 }
1323
1324 pr_info("driver initialized\n");
1325
1326 return 0;
1327}
1328
1329static void __exit ipmi_wdog_exit(void)
1330{
1331 ipmi_smi_watcher_unregister(&smi_watcher);
1332 ipmi_unregister_watchdog(watchdog_ifnum);
1333
1334#ifdef HAVE_DIE_NMI
1335 if (nmi_handler_registered)
1336 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1337#endif
1338
1339 unregister_reboot_notifier(&wdog_reboot_notifier);
1340}
1341module_exit(ipmi_wdog_exit);
1342module_init(ipmi_wdog_init);
1343MODULE_LICENSE("GPL");
1344MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1345MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");
1346