1 // SPDX-License-Identifier: GPL-2.0+
5 * A watchdog timer based upon the IPMI interface.
7 * Author: MontaVista Software, Inc.
8 * Corey Minyard <minyard@mvista.com>
11 * Copyright 2002 MontaVista Software Inc.
14 #define pr_fmt(fmt) "IPMI Watchdog: " fmt
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/kstrtox.h>
27 #include <linux/rwsem.h>
28 #include <linux/errno.h>
29 #include <linux/uaccess.h>
30 #include <linux/notifier.h>
31 #include <linux/nmi.h>
32 #include <linux/reboot.h>
33 #include <linux/wait.h>
34 #include <linux/poll.h>
35 #include <linux/string.h>
36 #include <linux/ctype.h>
37 #include <linux/delay.h>
38 #include <linux/atomic.h>
39 #include <linux/sched/signal.h>
43 * This is ugly, but I've determined that x86 is the only architecture
44 * that can reasonably support the IPMI NMI watchdog timeout at this
45 * time. If another architecture adds this capability somehow, it
46 * will have to be a somewhat different mechanism and I have no idea
47 * how it will work. So in the unlikely event that another
48 * architecture supports this, we can figure out a good generic
49 * mechanism for it at that time.
51 #include <asm/kdebug.h>
57 * The IPMI command/response information for the watchdog timer.
60 /* values for byte 1 of the set command, byte 2 of the get response. */
61 #define WDOG_DONT_LOG (1 << 7)
62 #define WDOG_DONT_STOP_ON_SET (1 << 6)
63 #define WDOG_SET_TIMER_USE(byte, use) \
64 byte = ((byte) & 0xf8) | ((use) & 0x7)
65 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
66 #define WDOG_TIMER_USE_BIOS_FRB2 1
67 #define WDOG_TIMER_USE_BIOS_POST 2
68 #define WDOG_TIMER_USE_OS_LOAD 3
69 #define WDOG_TIMER_USE_SMS_OS 4
70 #define WDOG_TIMER_USE_OEM 5
72 /* values for byte 2 of the set command, byte 3 of the get response. */
73 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
74 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
75 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
76 #define WDOG_PRETIMEOUT_NONE 0
77 #define WDOG_PRETIMEOUT_SMI 1
78 #define WDOG_PRETIMEOUT_NMI 2
79 #define WDOG_PRETIMEOUT_MSG_INT 3
81 /* Operations that can be performed on a pretimout. */
82 #define WDOG_PREOP_NONE 0
83 #define WDOG_PREOP_PANIC 1
84 /* Cause data to be available to read. Doesn't work in NMI mode. */
85 #define WDOG_PREOP_GIVE_DATA 2
87 /* Actions to perform on a full timeout. */
88 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
89 byte = ((byte) & 0xf8) | ((use) & 0x7)
90 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
91 #define WDOG_TIMEOUT_NONE 0
92 #define WDOG_TIMEOUT_RESET 1
93 #define WDOG_TIMEOUT_POWER_DOWN 2
94 #define WDOG_TIMEOUT_POWER_CYCLE 3
97 * Byte 3 of the get command, byte 4 of the get response is the
98 * pre-timeout in seconds.
101 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
102 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1)
103 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2)
104 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3)
105 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4)
106 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5)
109 * Setting/getting the watchdog timer value. This is for bytes 5 and
110 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
111 * timeout time) and 8 and 9 (the current countdown value) of the
112 * response. The timeout value is given in seconds (in the command it
113 * is 100ms intervals).
115 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
116 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
117 #define WDOG_GET_TIMEOUT(byte1, byte2) \
118 (((byte1) | ((byte2) << 8)) / 10)
120 #define IPMI_WDOG_RESET_TIMER 0x22
121 #define IPMI_WDOG_SET_TIMER 0x24
122 #define IPMI_WDOG_GET_TIMER 0x25
124 #define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80
126 static DEFINE_MUTEX(ipmi_watchdog_mutex
);
127 static bool nowayout
= WATCHDOG_NOWAYOUT
;
129 static struct ipmi_user
*watchdog_user
;
130 static int watchdog_ifnum
;
132 /* Default the timeout to 10 seconds. */
133 static int timeout
= 10;
135 /* The pre-timeout is disabled by default. */
136 static int pretimeout
;
138 /* Default timeout to set on panic */
139 static int panic_wdt_timeout
= 255;
141 /* Default action is to reset the board on a timeout. */
142 static unsigned char action_val
= WDOG_TIMEOUT_RESET
;
144 static char action
[16] = "reset";
146 static unsigned char preaction_val
= WDOG_PRETIMEOUT_NONE
;
148 static char preaction
[16] = "pre_none";
150 static unsigned char preop_val
= WDOG_PREOP_NONE
;
152 static char preop
[16] = "preop_none";
153 static DEFINE_SPINLOCK(ipmi_read_lock
);
154 static char data_to_read
;
155 static DECLARE_WAIT_QUEUE_HEAD(read_q
);
156 static struct fasync_struct
*fasync_q
;
157 static atomic_t pretimeout_since_last_heartbeat
;
158 static char expect_close
;
160 static int ifnum_to_use
= -1;
162 /* Parameters to ipmi_set_timeout */
163 #define IPMI_SET_TIMEOUT_NO_HB 0
164 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1
165 #define IPMI_SET_TIMEOUT_FORCE_HB 2
167 static int ipmi_set_timeout(int do_heartbeat
);
168 static void ipmi_register_watchdog(int ipmi_intf
);
169 static void ipmi_unregister_watchdog(int ipmi_intf
);
172 * If true, the driver will start running as soon as it is configured
175 static int start_now
;
177 static int set_param_timeout(const char *val
, const struct kernel_param
*kp
)
185 l
= simple_strtoul(val
, &endp
, 0);
189 *((int *)kp
->arg
) = l
;
191 rv
= ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY
);
196 static const struct kernel_param_ops param_ops_timeout
= {
197 .set
= set_param_timeout
,
198 .get
= param_get_int
,
200 #define param_check_timeout param_check_int
202 typedef int (*action_fn
)(const char *intval
, char *outval
);
204 static int action_op(const char *inval
, char *outval
);
205 static int preaction_op(const char *inval
, char *outval
);
206 static int preop_op(const char *inval
, char *outval
);
207 static void check_parms(void);
209 static int set_param_str(const char *val
, const struct kernel_param
*kp
)
211 action_fn fn
= (action_fn
) kp
->arg
;
216 strscpy(valcp
, val
, 16);
226 rv
= ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY
);
232 static int get_param_str(char *buffer
, const struct kernel_param
*kp
)
234 action_fn fn
= (action_fn
) kp
->arg
;
237 rv
= fn(NULL
, buffer
);
241 len
= strlen(buffer
);
242 buffer
[len
++] = '\n';
249 static int set_param_wdog_ifnum(const char *val
, const struct kernel_param
*kp
)
251 int rv
= param_set_int(val
, kp
);
254 if ((ifnum_to_use
< 0) || (ifnum_to_use
== watchdog_ifnum
))
257 ipmi_unregister_watchdog(watchdog_ifnum
);
258 ipmi_register_watchdog(ifnum_to_use
);
262 static const struct kernel_param_ops param_ops_wdog_ifnum
= {
263 .set
= set_param_wdog_ifnum
,
264 .get
= param_get_int
,
267 #define param_check_wdog_ifnum param_check_int
269 static const struct kernel_param_ops param_ops_str
= {
270 .set
= set_param_str
,
271 .get
= get_param_str
,
274 module_param(ifnum_to_use
, wdog_ifnum
, 0644);
275 MODULE_PARM_DESC(ifnum_to_use
, "The interface number to use for the watchdog "
276 "timer. Setting to -1 defaults to the first registered "
279 module_param(timeout
, timeout
, 0644);
280 MODULE_PARM_DESC(timeout
, "Timeout value in seconds.");
282 module_param(pretimeout
, timeout
, 0644);
283 MODULE_PARM_DESC(pretimeout
, "Pretimeout value in seconds.");
285 module_param(panic_wdt_timeout
, timeout
, 0644);
286 MODULE_PARM_DESC(panic_wdt_timeout
, "Timeout value on kernel panic in seconds.");
288 module_param_cb(action
, ¶m_ops_str
, action_op
, 0644);
289 MODULE_PARM_DESC(action
, "Timeout action. One of: "
290 "reset, none, power_cycle, power_off.");
292 module_param_cb(preaction
, ¶m_ops_str
, preaction_op
, 0644);
293 MODULE_PARM_DESC(preaction
, "Pretimeout action. One of: "
294 "pre_none, pre_smi, pre_nmi, pre_int.");
296 module_param_cb(preop
, ¶m_ops_str
, preop_op
, 0644);
297 MODULE_PARM_DESC(preop
, "Pretimeout driver operation. One of: "
298 "preop_none, preop_panic, preop_give_data.");
300 module_param(start_now
, int, 0444);
301 MODULE_PARM_DESC(start_now
, "Set to 1 to start the watchdog as"
302 "soon as the driver is loaded.");
304 module_param(nowayout
, bool, 0644);
305 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started "
306 "(default=CONFIG_WATCHDOG_NOWAYOUT)");
308 /* Default state of the timer. */
309 static unsigned char ipmi_watchdog_state
= WDOG_TIMEOUT_NONE
;
311 /* Is someone using the watchdog? Only one user is allowed. */
312 static unsigned long ipmi_wdog_open
;
315 * If set to 1, the heartbeat command will set the state to reset and
316 * start the timer. The timer doesn't normally run when the driver is
317 * first opened until the heartbeat is set the first time, this
318 * variable is used to accomplish this.
320 static int ipmi_start_timer_on_heartbeat
;
322 /* IPMI version of the BMC. */
323 static unsigned char ipmi_version_major
;
324 static unsigned char ipmi_version_minor
;
326 /* If a pretimeout occurs, this is used to allow only one panic to happen. */
327 static atomic_t preop_panic_excl
= ATOMIC_INIT(-1);
330 static int testing_nmi
;
331 static int nmi_handler_registered
;
334 static int __ipmi_heartbeat(void);
337 * We use a mutex to make sure that only one thing can send a set a
338 * message at one time. The mutex is claimed when a message is sent
339 * and freed when both the send and receive messages are free.
341 static atomic_t msg_tofree
= ATOMIC_INIT(0);
342 static DECLARE_COMPLETION(msg_wait
);
343 static void msg_free_smi(struct ipmi_smi_msg
*msg
)
345 if (atomic_dec_and_test(&msg_tofree
)) {
346 if (!oops_in_progress
)
350 static void msg_free_recv(struct ipmi_recv_msg
*msg
)
352 if (atomic_dec_and_test(&msg_tofree
)) {
353 if (!oops_in_progress
)
357 static struct ipmi_smi_msg smi_msg
= INIT_IPMI_SMI_MSG(msg_free_smi
);
358 static struct ipmi_recv_msg recv_msg
= INIT_IPMI_RECV_MSG(msg_free_recv
);
360 static int __ipmi_set_timeout(struct ipmi_smi_msg
*smi_msg
,
361 struct ipmi_recv_msg
*recv_msg
,
362 int *send_heartbeat_now
)
364 struct kernel_ipmi_msg msg
;
365 unsigned char data
[6];
367 struct ipmi_system_interface_addr addr
;
372 WDOG_SET_TIMER_USE(data
[0], WDOG_TIMER_USE_SMS_OS
);
374 if (ipmi_watchdog_state
!= WDOG_TIMEOUT_NONE
) {
375 if ((ipmi_version_major
> 1) ||
376 ((ipmi_version_major
== 1) && (ipmi_version_minor
>= 5))) {
377 /* This is an IPMI 1.5-only feature. */
378 data
[0] |= WDOG_DONT_STOP_ON_SET
;
381 * In ipmi 1.0, setting the timer stops the watchdog, we
382 * need to start it back up again.
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
;
394 WDOG_SET_PRETIMEOUT_ACT(data
[1], WDOG_PRETIMEOUT_NONE
);
395 data
[2] = 0; /* No pretimeout. */
398 WDOG_SET_TIMEOUT(data
[4], data
[5], timeout
);
400 addr
.addr_type
= IPMI_SYSTEM_INTERFACE_ADDR_TYPE
;
401 addr
.channel
= IPMI_BMC_CHANNEL
;
405 msg
.cmd
= IPMI_WDOG_SET_TIMER
;
407 msg
.data_len
= sizeof(data
);
408 rv
= ipmi_request_supply_msgs(watchdog_user
,
409 (struct ipmi_addr
*) &addr
,
417 pr_warn("set timeout error: %d\n", rv
);
418 else if (send_heartbeat_now
)
419 *send_heartbeat_now
= hbnow
;
424 static int _ipmi_set_timeout(int do_heartbeat
)
426 int send_heartbeat_now
;
432 atomic_set(&msg_tofree
, 2);
434 rv
= __ipmi_set_timeout(&smi_msg
,
436 &send_heartbeat_now
);
438 atomic_set(&msg_tofree
, 0);
442 wait_for_completion(&msg_wait
);
444 if ((do_heartbeat
== IPMI_SET_TIMEOUT_FORCE_HB
)
445 || ((send_heartbeat_now
)
446 && (do_heartbeat
== IPMI_SET_TIMEOUT_HB_IF_NECESSARY
)))
447 rv
= __ipmi_heartbeat();
452 static int ipmi_set_timeout(int do_heartbeat
)
456 mutex_lock(&ipmi_watchdog_mutex
);
457 rv
= _ipmi_set_timeout(do_heartbeat
);
458 mutex_unlock(&ipmi_watchdog_mutex
);
463 static atomic_t panic_done_count
= ATOMIC_INIT(0);
465 static void panic_smi_free(struct ipmi_smi_msg
*msg
)
467 atomic_dec(&panic_done_count
);
469 static void panic_recv_free(struct ipmi_recv_msg
*msg
)
471 atomic_dec(&panic_done_count
);
474 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg
=
475 INIT_IPMI_SMI_MSG(panic_smi_free
);
476 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg
=
477 INIT_IPMI_RECV_MSG(panic_recv_free
);
479 static void panic_halt_ipmi_heartbeat(void)
481 struct kernel_ipmi_msg msg
;
482 struct ipmi_system_interface_addr addr
;
486 * Don't reset the timer if we have the timer turned off, that
487 * re-enables the watchdog.
489 if (ipmi_watchdog_state
== WDOG_TIMEOUT_NONE
)
492 addr
.addr_type
= IPMI_SYSTEM_INTERFACE_ADDR_TYPE
;
493 addr
.channel
= IPMI_BMC_CHANNEL
;
497 msg
.cmd
= IPMI_WDOG_RESET_TIMER
;
500 atomic_add(2, &panic_done_count
);
501 rv
= ipmi_request_supply_msgs(watchdog_user
,
502 (struct ipmi_addr
*) &addr
,
506 &panic_halt_heartbeat_smi_msg
,
507 &panic_halt_heartbeat_recv_msg
,
510 atomic_sub(2, &panic_done_count
);
513 static struct ipmi_smi_msg panic_halt_smi_msg
=
514 INIT_IPMI_SMI_MSG(panic_smi_free
);
515 static struct ipmi_recv_msg panic_halt_recv_msg
=
516 INIT_IPMI_RECV_MSG(panic_recv_free
);
519 * Special call, doesn't claim any locks. This is only to be called
520 * at panic or halt time, in run-to-completion mode, when the caller
521 * is the only CPU and the only thing that will be going is these IPMI
524 static void panic_halt_ipmi_set_timeout(void)
526 int send_heartbeat_now
;
529 /* Wait for the messages to be free. */
530 while (atomic_read(&panic_done_count
) != 0)
531 ipmi_poll_interface(watchdog_user
);
532 atomic_add(2, &panic_done_count
);
533 rv
= __ipmi_set_timeout(&panic_halt_smi_msg
,
534 &panic_halt_recv_msg
,
535 &send_heartbeat_now
);
537 atomic_sub(2, &panic_done_count
);
538 pr_warn("Unable to extend the watchdog timeout\n");
540 if (send_heartbeat_now
)
541 panic_halt_ipmi_heartbeat();
543 while (atomic_read(&panic_done_count
) != 0)
544 ipmi_poll_interface(watchdog_user
);
547 static int __ipmi_heartbeat(void)
549 struct kernel_ipmi_msg msg
;
551 struct ipmi_system_interface_addr addr
;
552 int timeout_retries
= 0;
556 * Don't reset the timer if we have the timer turned off, that
557 * re-enables the watchdog.
559 if (ipmi_watchdog_state
== WDOG_TIMEOUT_NONE
)
562 atomic_set(&msg_tofree
, 2);
564 addr
.addr_type
= IPMI_SYSTEM_INTERFACE_ADDR_TYPE
;
565 addr
.channel
= IPMI_BMC_CHANNEL
;
569 msg
.cmd
= IPMI_WDOG_RESET_TIMER
;
572 rv
= ipmi_request_supply_msgs(watchdog_user
,
573 (struct ipmi_addr
*) &addr
,
581 atomic_set(&msg_tofree
, 0);
582 pr_warn("heartbeat send failure: %d\n", rv
);
586 /* Wait for the heartbeat to be sent. */
587 wait_for_completion(&msg_wait
);
589 if (recv_msg
.msg
.data
[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP
) {
591 if (timeout_retries
> 3) {
592 pr_err("Unable to restore the IPMI watchdog's settings, giving up\n");
598 * The timer was not initialized, that means the BMC was
599 * probably reset and lost the watchdog information. Attempt
600 * to restore the timer's info. Note that we still hold
601 * the heartbeat lock, to keep a heartbeat from happening
602 * in this process, so must say no heartbeat to avoid a
603 * deadlock on this mutex
605 rv
= _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
607 pr_err("Unable to send the command to set the watchdog's settings, giving up\n");
611 /* Might need a heartbeat send, go ahead and do it. */
613 } else if (recv_msg
.msg
.data
[0] != 0) {
615 * Got an error in the heartbeat response. It was already
616 * reported in ipmi_wdog_msg_handler, but we should return
626 static int _ipmi_heartbeat(void)
633 if (ipmi_start_timer_on_heartbeat
) {
634 ipmi_start_timer_on_heartbeat
= 0;
635 ipmi_watchdog_state
= action_val
;
636 rv
= _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB
);
637 } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat
, 1, 0)) {
639 * A pretimeout occurred, make sure we set the timeout.
640 * We don't want to set the action, though, we want to
641 * leave that alone (thus it can't be combined with the
644 rv
= _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY
);
646 rv
= __ipmi_heartbeat();
652 static int ipmi_heartbeat(void)
656 mutex_lock(&ipmi_watchdog_mutex
);
657 rv
= _ipmi_heartbeat();
658 mutex_unlock(&ipmi_watchdog_mutex
);
663 static const struct watchdog_info ident
= {
664 .options
= 0, /* WDIOF_SETTIMEOUT, */
665 .firmware_version
= 1,
669 static int ipmi_ioctl(struct file
*file
,
670 unsigned int cmd
, unsigned long arg
)
672 void __user
*argp
= (void __user
*)arg
;
677 case WDIOC_GETSUPPORT
:
678 i
= copy_to_user(argp
, &ident
, sizeof(ident
));
679 return i
? -EFAULT
: 0;
681 case WDIOC_SETTIMEOUT
:
682 i
= copy_from_user(&val
, argp
, sizeof(int));
686 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY
);
688 case WDIOC_GETTIMEOUT
:
689 i
= copy_to_user(argp
, &timeout
, sizeof(timeout
));
694 case WDIOC_SETPRETIMEOUT
:
695 i
= copy_from_user(&val
, argp
, sizeof(int));
699 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY
);
701 case WDIOC_GETPRETIMEOUT
:
702 i
= copy_to_user(argp
, &pretimeout
, sizeof(pretimeout
));
707 case WDIOC_KEEPALIVE
:
708 return _ipmi_heartbeat();
710 case WDIOC_SETOPTIONS
:
711 i
= copy_from_user(&val
, argp
, sizeof(int));
714 if (val
& WDIOS_DISABLECARD
) {
715 ipmi_watchdog_state
= WDOG_TIMEOUT_NONE
;
716 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
717 ipmi_start_timer_on_heartbeat
= 0;
720 if (val
& WDIOS_ENABLECARD
) {
721 ipmi_watchdog_state
= action_val
;
722 _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB
);
726 case WDIOC_GETSTATUS
:
728 i
= copy_to_user(argp
, &val
, sizeof(val
));
738 static long ipmi_unlocked_ioctl(struct file
*file
,
744 mutex_lock(&ipmi_watchdog_mutex
);
745 ret
= ipmi_ioctl(file
, cmd
, arg
);
746 mutex_unlock(&ipmi_watchdog_mutex
);
751 static ssize_t
ipmi_write(struct file
*file
,
752 const char __user
*buf
,
762 /* In case it was set long ago */
765 for (i
= 0; i
!= len
; i
++) {
768 if (get_user(c
, buf
+ i
))
774 rv
= ipmi_heartbeat();
781 static ssize_t
ipmi_read(struct file
*file
,
787 wait_queue_entry_t wait
;
793 * Reading returns if the pretimeout has gone off, and it only does
794 * it once per pretimeout.
796 spin_lock_irq(&ipmi_read_lock
);
798 if (file
->f_flags
& O_NONBLOCK
) {
803 init_waitqueue_entry(&wait
, current
);
804 add_wait_queue(&read_q
, &wait
);
805 while (!data_to_read
&& !signal_pending(current
)) {
806 set_current_state(TASK_INTERRUPTIBLE
);
807 spin_unlock_irq(&ipmi_read_lock
);
809 spin_lock_irq(&ipmi_read_lock
);
811 remove_wait_queue(&read_q
, &wait
);
813 if (signal_pending(current
)) {
821 spin_unlock_irq(&ipmi_read_lock
);
824 if (copy_to_user(buf
, &data_to_read
, 1))
833 static int ipmi_open(struct inode
*ino
, struct file
*filep
)
835 switch (iminor(ino
)) {
837 if (test_and_set_bit(0, &ipmi_wdog_open
))
842 * Don't start the timer now, let it start on the
845 ipmi_start_timer_on_heartbeat
= 1;
846 return stream_open(ino
, filep
);
853 static __poll_t
ipmi_poll(struct file
*file
, poll_table
*wait
)
857 poll_wait(file
, &read_q
, wait
);
859 spin_lock_irq(&ipmi_read_lock
);
861 mask
|= (EPOLLIN
| EPOLLRDNORM
);
862 spin_unlock_irq(&ipmi_read_lock
);
867 static int ipmi_fasync(int fd
, struct file
*file
, int on
)
871 result
= fasync_helper(fd
, file
, on
, &fasync_q
);
876 static int ipmi_close(struct inode
*ino
, struct file
*filep
)
878 if (iminor(ino
) == WATCHDOG_MINOR
) {
879 if (expect_close
== 42) {
880 mutex_lock(&ipmi_watchdog_mutex
);
881 ipmi_watchdog_state
= WDOG_TIMEOUT_NONE
;
882 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
883 mutex_unlock(&ipmi_watchdog_mutex
);
885 pr_crit("Unexpected close, not stopping watchdog!\n");
888 clear_bit(0, &ipmi_wdog_open
);
896 static const struct file_operations ipmi_wdog_fops
= {
897 .owner
= THIS_MODULE
,
901 .unlocked_ioctl
= ipmi_unlocked_ioctl
,
902 .compat_ioctl
= compat_ptr_ioctl
,
904 .release
= ipmi_close
,
905 .fasync
= ipmi_fasync
,
909 static struct miscdevice ipmi_wdog_miscdev
= {
910 .minor
= WATCHDOG_MINOR
,
912 .fops
= &ipmi_wdog_fops
915 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg
*msg
,
918 if (msg
->msg
.cmd
== IPMI_WDOG_RESET_TIMER
&&
919 msg
->msg
.data
[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP
)
920 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");
921 else if (msg
->msg
.data
[0] != 0)
922 pr_err("response: Error %x on cmd %x\n",
926 ipmi_free_recv_msg(msg
);
929 static void ipmi_wdog_pretimeout_handler(void *handler_data
)
931 if (preaction_val
!= WDOG_PRETIMEOUT_NONE
) {
932 if (preop_val
== WDOG_PREOP_PANIC
) {
933 if (atomic_inc_and_test(&preop_panic_excl
))
934 panic("Watchdog pre-timeout");
935 } else if (preop_val
== WDOG_PREOP_GIVE_DATA
) {
938 spin_lock_irqsave(&ipmi_read_lock
, flags
);
940 wake_up_interruptible(&read_q
);
941 kill_fasync(&fasync_q
, SIGIO
, POLL_IN
);
942 spin_unlock_irqrestore(&ipmi_read_lock
, flags
);
947 * On some machines, the heartbeat will give an error and not
948 * work unless we re-enable the timer. So do so.
950 atomic_set(&pretimeout_since_last_heartbeat
, 1);
953 static void ipmi_wdog_panic_handler(void *user_data
)
955 static int panic_event_handled
;
958 * On a panic, if we have a panic timeout, make sure to extend
959 * the watchdog timer to a reasonable value to complete the
960 * panic, if the watchdog timer is running. Plus the
961 * pretimeout is meaningless at panic time.
963 if (watchdog_user
&& !panic_event_handled
&&
964 ipmi_watchdog_state
!= WDOG_TIMEOUT_NONE
) {
965 /* Make sure we do this only once. */
966 panic_event_handled
= 1;
968 timeout
= panic_wdt_timeout
;
970 panic_halt_ipmi_set_timeout();
974 static const struct ipmi_user_hndl ipmi_hndlrs
= {
975 .ipmi_recv_hndl
= ipmi_wdog_msg_handler
,
976 .ipmi_watchdog_pretimeout
= ipmi_wdog_pretimeout_handler
,
977 .ipmi_panic_handler
= ipmi_wdog_panic_handler
980 static void ipmi_register_watchdog(int ipmi_intf
)
987 if ((ifnum_to_use
>= 0) && (ifnum_to_use
!= ipmi_intf
))
990 watchdog_ifnum
= ipmi_intf
;
992 rv
= ipmi_create_user(ipmi_intf
, &ipmi_hndlrs
, NULL
, &watchdog_user
);
994 pr_crit("Unable to register with ipmi\n");
998 rv
= ipmi_get_version(watchdog_user
,
1000 &ipmi_version_minor
);
1002 pr_warn("Unable to get IPMI version, assuming 1.0\n");
1003 ipmi_version_major
= 1;
1004 ipmi_version_minor
= 0;
1007 rv
= misc_register(&ipmi_wdog_miscdev
);
1009 ipmi_destroy_user(watchdog_user
);
1010 watchdog_user
= NULL
;
1011 pr_crit("Unable to register misc device\n");
1015 if (nmi_handler_registered
) {
1016 int old_pretimeout
= pretimeout
;
1017 int old_timeout
= timeout
;
1018 int old_preop_val
= preop_val
;
1021 * Set the pretimeout to go off in a second and give
1022 * ourselves plenty of time to stop the timer.
1024 ipmi_watchdog_state
= WDOG_TIMEOUT_RESET
;
1025 preop_val
= WDOG_PREOP_NONE
; /* Make sure nothing happens */
1031 rv
= ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB
);
1033 pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n",
1041 if (testing_nmi
!= 2) {
1042 pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n");
1046 preop_val
= old_preop_val
;
1047 pretimeout
= old_pretimeout
;
1048 timeout
= old_timeout
;
1053 if ((start_now
) && (rv
== 0)) {
1054 /* Run from startup, so start the timer now. */
1055 start_now
= 0; /* Disable this function after first startup. */
1056 ipmi_watchdog_state
= action_val
;
1057 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB
);
1058 pr_info("Starting now!\n");
1060 /* Stop the timer now. */
1061 ipmi_watchdog_state
= WDOG_TIMEOUT_NONE
;
1062 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
1066 static void ipmi_unregister_watchdog(int ipmi_intf
)
1069 struct ipmi_user
*loc_user
= watchdog_user
;
1074 if (watchdog_ifnum
!= ipmi_intf
)
1077 /* Make sure no one can call us any more. */
1078 misc_deregister(&ipmi_wdog_miscdev
);
1080 watchdog_user
= NULL
;
1083 * Wait to make sure the message makes it out. The lower layer has
1084 * pointers to our buffers, we want to make sure they are done before
1085 * we release our memory.
1087 while (atomic_read(&msg_tofree
))
1090 mutex_lock(&ipmi_watchdog_mutex
);
1092 /* Disconnect from IPMI. */
1093 rv
= ipmi_destroy_user(loc_user
);
1095 pr_warn("error unlinking from IPMI: %d\n", rv
);
1097 /* If it comes back, restart it properly. */
1098 ipmi_start_timer_on_heartbeat
= 1;
1100 mutex_unlock(&ipmi_watchdog_mutex
);
1105 ipmi_nmi(unsigned int val
, struct pt_regs
*regs
)
1108 * If we get here, it's an NMI that's not a memory or I/O
1109 * error. We can't truly tell if it's from IPMI or not
1110 * without sending a message, and sending a message is almost
1111 * impossible because of locking.
1119 /* If we are not expecting a timeout, ignore it. */
1120 if (ipmi_watchdog_state
== WDOG_TIMEOUT_NONE
)
1123 if (preaction_val
!= WDOG_PRETIMEOUT_NMI
)
1127 * If no one else handled the NMI, we assume it was the IPMI
1130 if (preop_val
== WDOG_PREOP_PANIC
) {
1131 /* On some machines, the heartbeat will give
1132 an error and not work unless we re-enable
1133 the timer. So do so. */
1134 atomic_set(&pretimeout_since_last_heartbeat
, 1);
1135 if (atomic_inc_and_test(&preop_panic_excl
))
1136 nmi_panic(regs
, "pre-timeout");
1143 static int wdog_reboot_handler(struct notifier_block
*this,
1147 static int reboot_event_handled
;
1149 if ((watchdog_user
) && (!reboot_event_handled
)) {
1150 /* Make sure we only do this once. */
1151 reboot_event_handled
= 1;
1153 if (code
== SYS_POWER_OFF
|| code
== SYS_HALT
) {
1154 /* Disable the WDT if we are shutting down. */
1155 ipmi_watchdog_state
= WDOG_TIMEOUT_NONE
;
1156 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
1157 } else if (ipmi_watchdog_state
!= WDOG_TIMEOUT_NONE
) {
1158 /* Set a long timer to let the reboot happen or
1159 reset if it hangs, but only if the watchdog
1160 timer was already running. */
1164 ipmi_watchdog_state
= WDOG_TIMEOUT_RESET
;
1165 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB
);
1171 static struct notifier_block wdog_reboot_notifier
= {
1172 .notifier_call
= wdog_reboot_handler
,
1177 static void ipmi_new_smi(int if_num
, struct device
*device
)
1179 ipmi_register_watchdog(if_num
);
1182 static void ipmi_smi_gone(int if_num
)
1184 ipmi_unregister_watchdog(if_num
);
1187 static struct ipmi_smi_watcher smi_watcher
= {
1188 .owner
= THIS_MODULE
,
1189 .new_smi
= ipmi_new_smi
,
1190 .smi_gone
= ipmi_smi_gone
1193 static int action_op(const char *inval
, char *outval
)
1196 strcpy(outval
, action
);
1201 if (strcmp(inval
, "reset") == 0)
1202 action_val
= WDOG_TIMEOUT_RESET
;
1203 else if (strcmp(inval
, "none") == 0)
1204 action_val
= WDOG_TIMEOUT_NONE
;
1205 else if (strcmp(inval
, "power_cycle") == 0)
1206 action_val
= WDOG_TIMEOUT_POWER_CYCLE
;
1207 else if (strcmp(inval
, "power_off") == 0)
1208 action_val
= WDOG_TIMEOUT_POWER_DOWN
;
1211 strcpy(action
, inval
);
1215 static int preaction_op(const char *inval
, char *outval
)
1218 strcpy(outval
, preaction
);
1223 if (strcmp(inval
, "pre_none") == 0)
1224 preaction_val
= WDOG_PRETIMEOUT_NONE
;
1225 else if (strcmp(inval
, "pre_smi") == 0)
1226 preaction_val
= WDOG_PRETIMEOUT_SMI
;
1228 else if (strcmp(inval
, "pre_nmi") == 0)
1229 preaction_val
= WDOG_PRETIMEOUT_NMI
;
1231 else if (strcmp(inval
, "pre_int") == 0)
1232 preaction_val
= WDOG_PRETIMEOUT_MSG_INT
;
1235 strcpy(preaction
, inval
);
1239 static int preop_op(const char *inval
, char *outval
)
1242 strcpy(outval
, preop
);
1247 if (strcmp(inval
, "preop_none") == 0)
1248 preop_val
= WDOG_PREOP_NONE
;
1249 else if (strcmp(inval
, "preop_panic") == 0)
1250 preop_val
= WDOG_PREOP_PANIC
;
1251 else if (strcmp(inval
, "preop_give_data") == 0)
1252 preop_val
= WDOG_PREOP_GIVE_DATA
;
1255 strcpy(preop
, inval
);
1259 static void check_parms(void)
1265 if (preaction_val
== WDOG_PRETIMEOUT_NMI
) {
1267 if (preop_val
== WDOG_PREOP_GIVE_DATA
) {
1268 pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n");
1269 preop_op("preop_none", NULL
);
1273 if (do_nmi
&& !nmi_handler_registered
) {
1274 rv
= register_nmi_handler(NMI_UNKNOWN
, ipmi_nmi
, 0,
1277 pr_warn("Can't register nmi handler\n");
1280 nmi_handler_registered
= 1;
1281 } else if (!do_nmi
&& nmi_handler_registered
) {
1282 unregister_nmi_handler(NMI_UNKNOWN
, "ipmi");
1283 nmi_handler_registered
= 0;
1288 static int __init
ipmi_wdog_init(void)
1292 if (action_op(action
, NULL
)) {
1293 action_op("reset", NULL
);
1294 pr_info("Unknown action '%s', defaulting to reset\n", action
);
1297 if (preaction_op(preaction
, NULL
)) {
1298 preaction_op("pre_none", NULL
);
1299 pr_info("Unknown preaction '%s', defaulting to none\n",
1303 if (preop_op(preop
, NULL
)) {
1304 preop_op("preop_none", NULL
);
1305 pr_info("Unknown preop '%s', defaulting to none\n", preop
);
1310 register_reboot_notifier(&wdog_reboot_notifier
);
1312 rv
= ipmi_smi_watcher_register(&smi_watcher
);
1315 if (nmi_handler_registered
)
1316 unregister_nmi_handler(NMI_UNKNOWN
, "ipmi");
1318 unregister_reboot_notifier(&wdog_reboot_notifier
);
1319 pr_warn("can't register smi watcher\n");
1323 pr_info("driver initialized\n");
1328 static void __exit
ipmi_wdog_exit(void)
1330 ipmi_smi_watcher_unregister(&smi_watcher
);
1331 ipmi_unregister_watchdog(watchdog_ifnum
);
1334 if (nmi_handler_registered
)
1335 unregister_nmi_handler(NMI_UNKNOWN
, "ipmi");
1338 unregister_reboot_notifier(&wdog_reboot_notifier
);
1340 module_exit(ipmi_wdog_exit
);
1341 module_init(ipmi_wdog_init
);
1342 MODULE_LICENSE("GPL");
1343 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1344 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");