forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathipmi_watchdog.c
1344 lines (1118 loc) · 32.2 KB
/
ipmi_watchdog.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0+
/*
* ipmi_watchdog.c
*
* A watchdog timer based upon the IPMI interface.
*
* Author: MontaVista Software, Inc.
* Corey Minyard <minyard@mvista.com>
* source@mvista.com
*
* Copyright 2002 MontaVista Software Inc.
*/
#define pr_fmt(fmt) "IPMI Watchdog: " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>
#include <linux/mutex.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/kdebug.h>
#include <linux/kstrtox.h>
#include <linux/rwsem.h>
#include <linux/errno.h>
#include <linux/uaccess.h>
#include <linux/notifier.h>
#include <linux/nmi.h>
#include <linux/reboot.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/sched/signal.h>
#ifdef CONFIG_X86
/*
* This is ugly, but I've determined that x86 is the only architecture
* that can reasonably support the IPMI NMI watchdog timeout at this
* time. If another architecture adds this capability somehow, it
* will have to be a somewhat different mechanism and I have no idea
* how it will work. So in the unlikely event that another
* architecture supports this, we can figure out a good generic
* mechanism for it at that time.
*/
#include <asm/kdebug.h>
#include <asm/nmi.h>
#define HAVE_DIE_NMI
#endif
/*
* The IPMI command/response information for the watchdog timer.
*/
/* values for byte 1 of the set command, byte 2 of the get response. */
#define WDOG_DONT_LOG (1 << 7)
#define WDOG_DONT_STOP_ON_SET (1 << 6)
#define WDOG_SET_TIMER_USE(byte, use) \
byte = ((byte) & 0xf8) | ((use) & 0x7)
#define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
#define WDOG_TIMER_USE_BIOS_FRB2 1
#define WDOG_TIMER_USE_BIOS_POST 2
#define WDOG_TIMER_USE_OS_LOAD 3
#define WDOG_TIMER_USE_SMS_OS 4
#define WDOG_TIMER_USE_OEM 5
/* values for byte 2 of the set command, byte 3 of the get response. */
#define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
#define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
#define WDOG_PRETIMEOUT_NONE 0
#define WDOG_PRETIMEOUT_SMI 1
#define WDOG_PRETIMEOUT_NMI 2
#define WDOG_PRETIMEOUT_MSG_INT 3
/* Operations that can be performed on a pretimout. */
#define WDOG_PREOP_NONE 0
#define WDOG_PREOP_PANIC 1
/* Cause data to be available to read. Doesn't work in NMI mode. */
#define WDOG_PREOP_GIVE_DATA 2
/* Actions to perform on a full timeout. */
#define WDOG_SET_TIMEOUT_ACT(byte, use) \
byte = ((byte) & 0xf8) | ((use) & 0x7)
#define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
#define WDOG_TIMEOUT_NONE 0
#define WDOG_TIMEOUT_RESET 1
#define WDOG_TIMEOUT_POWER_DOWN 2
#define WDOG_TIMEOUT_POWER_CYCLE 3
/*
* Byte 3 of the get command, byte 4 of the get response is the
* pre-timeout in seconds.
*/
/* Bits for setting byte 4 of the set command, byte 5 of the get response. */
#define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1)
#define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2)
#define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3)
#define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4)
#define WDOG_EXPIRE_CLEAR_OEM (1 << 5)
/*
* Setting/getting the watchdog timer value. This is for bytes 5 and
* 6 (the timeout time) of the set command, and bytes 6 and 7 (the
* timeout time) and 8 and 9 (the current countdown value) of the
* response. The timeout value is given in seconds (in the command it
* is 100ms intervals).
*/
#define WDOG_SET_TIMEOUT(byte1, byte2, val) \
(byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
#define WDOG_GET_TIMEOUT(byte1, byte2) \
(((byte1) | ((byte2) << 8)) / 10)
#define IPMI_WDOG_RESET_TIMER 0x22
#define IPMI_WDOG_SET_TIMER 0x24
#define IPMI_WDOG_GET_TIMER 0x25
#define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80
static DEFINE_MUTEX(ipmi_watchdog_mutex);
static bool nowayout = WATCHDOG_NOWAYOUT;
static struct ipmi_user *watchdog_user;
static int watchdog_ifnum;
/* Default the timeout to 10 seconds. */
static int timeout = 10;
/* The pre-timeout is disabled by default. */
static int pretimeout;
/* Default timeout to set on panic */
static int panic_wdt_timeout = 255;
/* Default action is to reset the board on a timeout. */
static unsigned char action_val = WDOG_TIMEOUT_RESET;
static char action[16] = "reset";
static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
static char preaction[16] = "pre_none";
static unsigned char preop_val = WDOG_PREOP_NONE;
static char preop[16] = "preop_none";
static DEFINE_SPINLOCK(ipmi_read_lock);
static char data_to_read;
static DECLARE_WAIT_QUEUE_HEAD(read_q);
static struct fasync_struct *fasync_q;
static atomic_t pretimeout_since_last_heartbeat;
static char expect_close;
static int ifnum_to_use = -1;
/* Parameters to ipmi_set_timeout */
#define IPMI_SET_TIMEOUT_NO_HB 0
#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1
#define IPMI_SET_TIMEOUT_FORCE_HB 2
static int ipmi_set_timeout(int do_heartbeat);
static void ipmi_register_watchdog(int ipmi_intf);
static void ipmi_unregister_watchdog(int ipmi_intf);
/*
* If true, the driver will start running as soon as it is configured
* and ready.
*/
static int start_now;
static int set_param_timeout(const char *val, const struct kernel_param *kp)
{
char *endp;
int l;
int rv = 0;
if (!val)
return -EINVAL;
l = simple_strtoul(val, &endp, 0);
if (endp == val)
return -EINVAL;
*((int *)kp->arg) = l;
if (watchdog_user)
rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
return rv;
}
static const struct kernel_param_ops param_ops_timeout = {
.set = set_param_timeout,
.get = param_get_int,
};
#define param_check_timeout param_check_int
typedef int (*action_fn)(const char *intval, char *outval);
static int action_op(const char *inval, char *outval);
static int preaction_op(const char *inval, char *outval);
static int preop_op(const char *inval, char *outval);
static void check_parms(void);
static int set_param_str(const char *val, const struct kernel_param *kp)
{
action_fn fn = (action_fn) kp->arg;
int rv = 0;
char valcp[16];
char *s;
strscpy(valcp, val, 16);
s = strstrip(valcp);
rv = fn(s, NULL);
if (rv)
goto out;
check_parms();
if (watchdog_user)
rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
out:
return rv;
}
static int get_param_str(char *buffer, const struct kernel_param *kp)
{
action_fn fn = (action_fn) kp->arg;
int rv, len;
rv = fn(NULL, buffer);
if (rv)
return rv;
len = strlen(buffer);
buffer[len++] = '\n';
buffer[len] = 0;
return len;
}
static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp)
{
int rv = param_set_int(val, kp);
if (rv)
return rv;
if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
return 0;
ipmi_unregister_watchdog(watchdog_ifnum);
ipmi_register_watchdog(ifnum_to_use);
return 0;
}
static const struct kernel_param_ops param_ops_wdog_ifnum = {
.set = set_param_wdog_ifnum,
.get = param_get_int,
};
#define param_check_wdog_ifnum param_check_int
static const struct kernel_param_ops param_ops_str = {
.set = set_param_str,
.get = get_param_str,
};
module_param(ifnum_to_use, wdog_ifnum, 0644);
MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
"timer. Setting to -1 defaults to the first registered "
"interface");
module_param(timeout, timeout, 0644);
MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
module_param(pretimeout, timeout, 0644);
MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
module_param(panic_wdt_timeout, timeout, 0644);
MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds.");
module_param_cb(action, ¶m_ops_str, action_op, 0644);
MODULE_PARM_DESC(action, "Timeout action. One of: "
"reset, none, power_cycle, power_off.");
module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644);
MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "
"pre_none, pre_smi, pre_nmi, pre_int.");
module_param_cb(preop, ¶m_ops_str, preop_op, 0644);
MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "
"preop_none, preop_panic, preop_give_data.");
module_param(start_now, int, 0444);
MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
"soon as the driver is loaded.");
module_param(nowayout, bool, 0644);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=CONFIG_WATCHDOG_NOWAYOUT)");
/* Default state of the timer. */
static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
/* Is someone using the watchdog? Only one user is allowed. */
static unsigned long ipmi_wdog_open;
/*
* If set to 1, the heartbeat command will set the state to reset and
* start the timer. The timer doesn't normally run when the driver is
* first opened until the heartbeat is set the first time, this
* variable is used to accomplish this.
*/
static int ipmi_start_timer_on_heartbeat;
/* IPMI version of the BMC. */
static unsigned char ipmi_version_major;
static unsigned char ipmi_version_minor;
/* If a pretimeout occurs, this is used to allow only one panic to happen. */
static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
#ifdef HAVE_DIE_NMI
static int testing_nmi;
static int nmi_handler_registered;
#endif
static int __ipmi_heartbeat(void);
/*
* We use a mutex to make sure that only one thing can send a set a
* message at one time. The mutex is claimed when a message is sent
* and freed when both the send and receive messages are free.
*/
static atomic_t msg_tofree = ATOMIC_INIT(0);
static DECLARE_COMPLETION(msg_wait);
static void msg_free_smi(struct ipmi_smi_msg *msg)
{
if (atomic_dec_and_test(&msg_tofree)) {
if (!oops_in_progress)
complete(&msg_wait);
}
}
static void msg_free_recv(struct ipmi_recv_msg *msg)
{
if (atomic_dec_and_test(&msg_tofree)) {
if (!oops_in_progress)
complete(&msg_wait);
}
}
static struct ipmi_smi_msg smi_msg = INIT_IPMI_SMI_MSG(msg_free_smi);
static struct ipmi_recv_msg recv_msg = INIT_IPMI_RECV_MSG(msg_free_recv);
static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg,
struct ipmi_recv_msg *recv_msg,
int *send_heartbeat_now)
{
struct kernel_ipmi_msg msg;
unsigned char data[6];
int rv;
struct ipmi_system_interface_addr addr;
int hbnow = 0;
data[0] = 0;
WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
if ((ipmi_version_major > 1) ||
((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
/* This is an IPMI 1.5-only feature. */
data[0] |= WDOG_DONT_STOP_ON_SET;
} else {
/*
* In ipmi 1.0, setting the timer stops the watchdog, we
* need to start it back up again.
*/
hbnow = 1;
}
}
data[1] = 0;
WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
data[2] = pretimeout;
} else {
WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
data[2] = 0; /* No pretimeout. */
}
data[3] = 0;
WDOG_SET_TIMEOUT(data[4], data[5], timeout);
addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
addr.channel = IPMI_BMC_CHANNEL;
addr.lun = 0;
msg.netfn = 0x06;
msg.cmd = IPMI_WDOG_SET_TIMER;
msg.data = data;
msg.data_len = sizeof(data);
rv = ipmi_request_supply_msgs(watchdog_user,
(struct ipmi_addr *) &addr,
0,
&msg,
NULL,
smi_msg,
recv_msg,
1);
if (rv)
pr_warn("set timeout error: %d\n", rv);
else if (send_heartbeat_now)
*send_heartbeat_now = hbnow;
return rv;
}
static int _ipmi_set_timeout(int do_heartbeat)
{
int send_heartbeat_now;
int rv;
if (!watchdog_user)
return -ENODEV;
atomic_set(&msg_tofree, 2);
rv = __ipmi_set_timeout(&smi_msg,
&recv_msg,
&send_heartbeat_now);
if (rv) {
atomic_set(&msg_tofree, 0);
return rv;
}
wait_for_completion(&msg_wait);
if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
|| ((send_heartbeat_now)
&& (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
rv = __ipmi_heartbeat();
return rv;
}
static int ipmi_set_timeout(int do_heartbeat)
{
int rv;
mutex_lock(&ipmi_watchdog_mutex);
rv = _ipmi_set_timeout(do_heartbeat);
mutex_unlock(&ipmi_watchdog_mutex);
return rv;
}
static atomic_t panic_done_count = ATOMIC_INIT(0);
static void panic_smi_free(struct ipmi_smi_msg *msg)
{
atomic_dec(&panic_done_count);
}
static void panic_recv_free(struct ipmi_recv_msg *msg)
{
atomic_dec(&panic_done_count);
}
static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg =
INIT_IPMI_SMI_MSG(panic_smi_free);
static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
INIT_IPMI_RECV_MSG(panic_recv_free);
static void panic_halt_ipmi_heartbeat(void)
{
struct kernel_ipmi_msg msg;
struct ipmi_system_interface_addr addr;
int rv;
/*
* Don't reset the timer if we have the timer turned off, that
* re-enables the watchdog.
*/
if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
return;
addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
addr.channel = IPMI_BMC_CHANNEL;
addr.lun = 0;
msg.netfn = 0x06;
msg.cmd = IPMI_WDOG_RESET_TIMER;
msg.data = NULL;
msg.data_len = 0;
atomic_add(2, &panic_done_count);
rv = ipmi_request_supply_msgs(watchdog_user,
(struct ipmi_addr *) &addr,
0,
&msg,
NULL,
&panic_halt_heartbeat_smi_msg,
&panic_halt_heartbeat_recv_msg,
1);
if (rv)
atomic_sub(2, &panic_done_count);
}
static struct ipmi_smi_msg panic_halt_smi_msg =
INIT_IPMI_SMI_MSG(panic_smi_free);
static struct ipmi_recv_msg panic_halt_recv_msg =
INIT_IPMI_RECV_MSG(panic_recv_free);
/*
* Special call, doesn't claim any locks. This is only to be called
* at panic or halt time, in run-to-completion mode, when the caller
* is the only CPU and the only thing that will be going is these IPMI
* calls.
*/
static void panic_halt_ipmi_set_timeout(void)
{
int send_heartbeat_now;
int rv;
/* Wait for the messages to be free. */
while (atomic_read(&panic_done_count) != 0)
ipmi_poll_interface(watchdog_user);
atomic_add(2, &panic_done_count);
rv = __ipmi_set_timeout(&panic_halt_smi_msg,
&panic_halt_recv_msg,
&send_heartbeat_now);
if (rv) {
atomic_sub(2, &panic_done_count);
pr_warn("Unable to extend the watchdog timeout\n");
} else {
if (send_heartbeat_now)
panic_halt_ipmi_heartbeat();
}
while (atomic_read(&panic_done_count) != 0)
ipmi_poll_interface(watchdog_user);
}
static int __ipmi_heartbeat(void)
{
struct kernel_ipmi_msg msg;
int rv;
struct ipmi_system_interface_addr addr;
int timeout_retries = 0;
restart:
/*
* Don't reset the timer if we have the timer turned off, that
* re-enables the watchdog.
*/
if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
return 0;
atomic_set(&msg_tofree, 2);
addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
addr.channel = IPMI_BMC_CHANNEL;
addr.lun = 0;
msg.netfn = 0x06;
msg.cmd = IPMI_WDOG_RESET_TIMER;
msg.data = NULL;
msg.data_len = 0;
rv = ipmi_request_supply_msgs(watchdog_user,
(struct ipmi_addr *) &addr,
0,
&msg,
NULL,
&smi_msg,
&recv_msg,
1);
if (rv) {
atomic_set(&msg_tofree, 0);
pr_warn("heartbeat send failure: %d\n", rv);
return rv;
}
/* Wait for the heartbeat to be sent. */
wait_for_completion(&msg_wait);
if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) {
timeout_retries++;
if (timeout_retries > 3) {
pr_err("Unable to restore the IPMI watchdog's settings, giving up\n");
rv = -EIO;
goto out;
}
/*
* The timer was not initialized, that means the BMC was
* probably reset and lost the watchdog information. Attempt
* to restore the timer's info. Note that we still hold
* the heartbeat lock, to keep a heartbeat from happening
* in this process, so must say no heartbeat to avoid a
* deadlock on this mutex
*/
rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
if (rv) {
pr_err("Unable to send the command to set the watchdog's settings, giving up\n");
goto out;
}
/* Might need a heartbeat send, go ahead and do it. */
goto restart;
} else if (recv_msg.msg.data[0] != 0) {
/*
* Got an error in the heartbeat response. It was already
* reported in ipmi_wdog_msg_handler, but we should return
* an error here.
*/
rv = -EINVAL;
}
out:
return rv;
}
static int _ipmi_heartbeat(void)
{
int rv;
if (!watchdog_user)
return -ENODEV;
if (ipmi_start_timer_on_heartbeat) {
ipmi_start_timer_on_heartbeat = 0;
ipmi_watchdog_state = action_val;
rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
} else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) {
/*
* A pretimeout occurred, make sure we set the timeout.
* We don't want to set the action, though, we want to
* leave that alone (thus it can't be combined with the
* above operation.
*/
rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
} else {
rv = __ipmi_heartbeat();
}
return rv;
}
static int ipmi_heartbeat(void)
{
int rv;
mutex_lock(&ipmi_watchdog_mutex);
rv = _ipmi_heartbeat();
mutex_unlock(&ipmi_watchdog_mutex);
return rv;
}
static const struct watchdog_info ident = {
.options = 0, /* WDIOF_SETTIMEOUT, */
.firmware_version = 1,
.identity = "IPMI"
};
static int ipmi_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int i;
int val;
switch (cmd) {
case WDIOC_GETSUPPORT:
i = copy_to_user(argp, &ident, sizeof(ident));
return i ? -EFAULT : 0;
case WDIOC_SETTIMEOUT:
i = copy_from_user(&val, argp, sizeof(int));
if (i)
return -EFAULT;
timeout = val;
return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
case WDIOC_GETTIMEOUT:
i = copy_to_user(argp, &timeout, sizeof(timeout));
if (i)
return -EFAULT;
return 0;
case WDIOC_SETPRETIMEOUT:
i = copy_from_user(&val, argp, sizeof(int));
if (i)
return -EFAULT;
pretimeout = val;
return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
case WDIOC_GETPRETIMEOUT:
i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
if (i)
return -EFAULT;
return 0;
case WDIOC_KEEPALIVE:
return _ipmi_heartbeat();
case WDIOC_SETOPTIONS:
i = copy_from_user(&val, argp, sizeof(int));
if (i)
return -EFAULT;
if (val & WDIOS_DISABLECARD) {
ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
_ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
ipmi_start_timer_on_heartbeat = 0;
}
if (val & WDIOS_ENABLECARD) {
ipmi_watchdog_state = action_val;
_ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
}
return 0;
case WDIOC_GETSTATUS:
val = 0;
i = copy_to_user(argp, &val, sizeof(val));
if (i)
return -EFAULT;
return 0;
default:
return -ENOIOCTLCMD;
}
}
static long ipmi_unlocked_ioctl(struct file *file,
unsigned int cmd,
unsigned long arg)
{
int ret;
mutex_lock(&ipmi_watchdog_mutex);
ret = ipmi_ioctl(file, cmd, arg);
mutex_unlock(&ipmi_watchdog_mutex);
return ret;
}
static ssize_t ipmi_write(struct file *file,
const char __user *buf,
size_t len,
loff_t *ppos)
{
int rv;
if (len) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
rv = ipmi_heartbeat();
if (rv)
return rv;
}
return len;
}
static ssize_t ipmi_read(struct file *file,
char __user *buf,
size_t count,
loff_t *ppos)
{
int rv = 0;
wait_queue_entry_t wait;
if (count <= 0)
return 0;
/*
* Reading returns if the pretimeout has gone off, and it only does
* it once per pretimeout.
*/
spin_lock_irq(&ipmi_read_lock);
if (!data_to_read) {
if (file->f_flags & O_NONBLOCK) {
rv = -EAGAIN;
goto out;
}
init_waitqueue_entry(&wait, current);
add_wait_queue(&read_q, &wait);
while (!data_to_read) {
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&ipmi_read_lock);
schedule();
spin_lock_irq(&ipmi_read_lock);
}
remove_wait_queue(&read_q, &wait);
if (signal_pending(current)) {
rv = -ERESTARTSYS;
goto out;
}
}
data_to_read = 0;
out:
spin_unlock_irq(&ipmi_read_lock);
if (rv == 0) {
if (copy_to_user(buf, &data_to_read, 1))
rv = -EFAULT;
else
rv = 1;
}
return rv;
}
static int ipmi_open(struct inode *ino, struct file *filep)
{
switch (iminor(ino)) {
case WATCHDOG_MINOR:
if (test_and_set_bit(0, &ipmi_wdog_open))
return -EBUSY;
/*
* Don't start the timer now, let it start on the
* first heartbeat.
*/
ipmi_start_timer_on_heartbeat = 1;
return stream_open(ino, filep);
default:
return (-ENODEV);
}
}
static __poll_t ipmi_poll(struct file *file, poll_table *wait)
{
__poll_t mask = 0;
poll_wait(file, &read_q, wait);
spin_lock_irq(&ipmi_read_lock);
if (data_to_read)
mask |= (EPOLLIN | EPOLLRDNORM);
spin_unlock_irq(&ipmi_read_lock);
return mask;
}
static int ipmi_fasync(int fd, struct file *file, int on)
{
int result;
result = fasync_helper(fd, file, on, &fasync_q);
return (result);
}
static int ipmi_close(struct inode *ino, struct file *filep)
{
if (iminor(ino) == WATCHDOG_MINOR) {
if (expect_close == 42) {
mutex_lock(&ipmi_watchdog_mutex);
ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
_ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
mutex_unlock(&ipmi_watchdog_mutex);
} else {
pr_crit("Unexpected close, not stopping watchdog!\n");
ipmi_heartbeat();
}
clear_bit(0, &ipmi_wdog_open);
}
expect_close = 0;
return 0;
}
static const struct file_operations ipmi_wdog_fops = {
.owner = THIS_MODULE,
.read = ipmi_read,
.poll = ipmi_poll,
.write = ipmi_write,
.unlocked_ioctl = ipmi_unlocked_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = ipmi_open,
.release = ipmi_close,
.fasync = ipmi_fasync,
.llseek = no_llseek,
};
static struct miscdevice ipmi_wdog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ipmi_wdog_fops
};
static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
void *handler_data)
{
if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");
else if (msg->msg.data[0] != 0)
pr_err("response: Error %x on cmd %x\n",
msg->msg.data[0],
msg->msg.cmd);
ipmi_free_recv_msg(msg);
}
static void ipmi_wdog_pretimeout_handler(void *handler_data)
{
if (preaction_val != WDOG_PRETIMEOUT_NONE) {
if (preop_val == WDOG_PREOP_PANIC) {
if (atomic_inc_and_test(&preop_panic_excl))
panic("Watchdog pre-timeout");
} else if (preop_val == WDOG_PREOP_GIVE_DATA) {
unsigned long flags;
spin_lock_irqsave(&ipmi_read_lock, flags);
data_to_read = 1;
wake_up_interruptible(&read_q);
kill_fasync(&fasync_q, SIGIO, POLL_IN);
spin_unlock_irqrestore(&ipmi_read_lock, flags);
}
}
/*
* On some machines, the heartbeat will give an error and not
* work unless we re-enable the timer. So do so.
*/
atomic_set(&pretimeout_since_last_heartbeat, 1);
}
static void ipmi_wdog_panic_handler(void *user_data)
{
static int panic_event_handled;
/*
* On a panic, if we have a panic timeout, make sure to extend
* the watchdog timer to a reasonable value to complete the
* panic, if the watchdog timer is running. Plus the
* pretimeout is meaningless at panic time.
*/
if (watchdog_user && !panic_event_handled &&
ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
/* Make sure we do this only once. */
panic_event_handled = 1;
timeout = panic_wdt_timeout;
pretimeout = 0;
panic_halt_ipmi_set_timeout();
}
}
static const struct ipmi_user_hndl ipmi_hndlrs = {
.ipmi_recv_hndl = ipmi_wdog_msg_handler,
.ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler,
.ipmi_panic_handler = ipmi_wdog_panic_handler
};
static void ipmi_register_watchdog(int ipmi_intf)
{
int rv = -EBUSY;
if (watchdog_user)
goto out;
if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
goto out;
watchdog_ifnum = ipmi_intf;
rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
if (rv < 0) {
pr_crit("Unable to register with ipmi\n");
goto out;
}
rv = ipmi_get_version(watchdog_user,
&ipmi_version_major,
&ipmi_version_minor);