2 * Machine check handler.
4 * K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs.
5 * Rest from unknown author(s).
6 * 2004 Andi Kleen. Rewrote most of it.
7 * Copyright 2008 Intel Corporation
10 #include <linux/thread_info.h>
11 #include <linux/capability.h>
12 #include <linux/miscdevice.h>
13 #include <linux/ratelimit.h>
14 #include <linux/kallsyms.h>
15 #include <linux/rcupdate.h>
16 #include <linux/kobject.h>
17 #include <linux/uaccess.h>
18 #include <linux/kdebug.h>
19 #include <linux/kernel.h>
20 #include <linux/percpu.h>
21 #include <linux/string.h>
22 #include <linux/sysdev.h>
23 #include <linux/ctype.h>
24 #include <linux/sched.h>
25 #include <linux/sysfs.h>
26 #include <linux/types.h>
27 #include <linux/init.h>
28 #include <linux/kmod.h>
29 #include <linux/poll.h>
30 #include <linux/cpu.h>
31 #include <linux/smp.h>
34 #include <asm/processor.h>
41 /* Handle unconfigured int18 (should never happen) */
42 static void unexpected_machine_check(struct pt_regs
*regs
, long error_code
)
44 printk(KERN_ERR
"CPU#%d: Unexpected int18 (Machine Check).\n",
48 /* Call the installed machine check handler for this CPU setup. */
49 void (*machine_check_vector
)(struct pt_regs
*, long error_code
) =
50 unexpected_machine_check
;
54 #ifdef CONFIG_X86_NEW_MCE
56 #define MISC_MCELOG_MINOR 227
60 DEFINE_PER_CPU(unsigned, mce_exception_count
);
64 * 0: always panic on uncorrected errors, log corrected errors
65 * 1: panic or SIGBUS on uncorrected errors, log corrected errors
66 * 2: SIGBUS or log uncorrected errors (if possible), log corrected errors
67 * 3: never panic or SIGBUS, log all errors (for testing only)
69 static int tolerant
= 1;
72 static unsigned long notify_user
;
74 static int mce_bootlog
= -1;
76 static char trigger
[128];
77 static char *trigger_argv
[2] = { trigger
, NULL
};
79 static unsigned long dont_init_banks
;
81 static DECLARE_WAIT_QUEUE_HEAD(mce_wait
);
83 /* MCA banks polled by the period polling timer for corrected events */
84 DEFINE_PER_CPU(mce_banks_t
, mce_poll_banks
) = {
85 [0 ... BITS_TO_LONGS(MAX_NR_BANKS
)-1] = ~0UL
88 static inline int skip_bank_init(int i
)
90 return i
< BITS_PER_LONG
&& test_bit(i
, &dont_init_banks
);
93 /* Do initial initialization of a struct mce */
94 void mce_setup(struct mce
*m
)
96 memset(m
, 0, sizeof(struct mce
));
97 m
->cpu
= smp_processor_id();
101 DEFINE_PER_CPU(struct mce
, injectm
);
102 EXPORT_PER_CPU_SYMBOL_GPL(injectm
);
105 * Lockless MCE logging infrastructure.
106 * This avoids deadlocks on printk locks without having to break locks. Also
107 * separate MCEs from kernel messages to avoid bogus bug reports.
110 static struct mce_log mcelog
= {
115 void mce_log(struct mce
*mce
)
117 unsigned next
, entry
;
122 entry
= rcu_dereference(mcelog
.next
);
125 * When the buffer fills up discard new entries.
126 * Assume that the earlier errors are the more
129 if (entry
>= MCE_LOG_LEN
) {
130 set_bit(MCE_OVERFLOW
,
131 (unsigned long *)&mcelog
.flags
);
134 /* Old left over entry. Skip: */
135 if (mcelog
.entry
[entry
].finished
) {
143 if (cmpxchg(&mcelog
.next
, entry
, next
) == entry
)
146 memcpy(mcelog
.entry
+ entry
, mce
, sizeof(struct mce
));
148 mcelog
.entry
[entry
].finished
= 1;
151 set_bit(0, ¬ify_user
);
154 static void print_mce(struct mce
*m
)
156 printk(KERN_EMERG
"\n"
157 KERN_EMERG
"HARDWARE ERROR\n"
159 "CPU %d: Machine Check Exception: %16Lx Bank %d: %016Lx\n",
160 m
->cpu
, m
->mcgstatus
, m
->bank
, m
->status
);
162 printk(KERN_EMERG
"RIP%s %02x:<%016Lx> ",
163 !(m
->mcgstatus
& MCG_STATUS_EIPV
) ? " !INEXACT!" : "",
165 if (m
->cs
== __KERNEL_CS
)
166 print_symbol("{%s}", m
->ip
);
169 printk(KERN_EMERG
"TSC %llx ", m
->tsc
);
171 printk("ADDR %llx ", m
->addr
);
173 printk("MISC %llx ", m
->misc
);
175 printk(KERN_EMERG
"This is not a software problem!\n");
176 printk(KERN_EMERG
"Run through mcelog --ascii to decode "
177 "and contact your hardware vendor\n");
180 static void mce_panic(char *msg
, struct mce
*backup
, u64 start
)
186 for (i
= 0; i
< MCE_LOG_LEN
; i
++) {
187 u64 tsc
= mcelog
.entry
[i
].tsc
;
189 if ((s64
)(tsc
- start
) < 0)
191 print_mce(&mcelog
.entry
[i
]);
192 if (backup
&& mcelog
.entry
[i
].tsc
== backup
->tsc
)
200 /* Support code for software error injection */
202 static int msr_to_offset(u32 msr
)
204 unsigned bank
= __get_cpu_var(injectm
.bank
);
206 return offsetof(struct mce
, ip
);
207 if (msr
== MSR_IA32_MC0_STATUS
+ bank
*4)
208 return offsetof(struct mce
, status
);
209 if (msr
== MSR_IA32_MC0_ADDR
+ bank
*4)
210 return offsetof(struct mce
, addr
);
211 if (msr
== MSR_IA32_MC0_MISC
+ bank
*4)
212 return offsetof(struct mce
, misc
);
213 if (msr
== MSR_IA32_MCG_STATUS
)
214 return offsetof(struct mce
, mcgstatus
);
218 /* MSR access wrappers used for error injection */
219 static u64
mce_rdmsrl(u32 msr
)
222 if (__get_cpu_var(injectm
).finished
) {
223 int offset
= msr_to_offset(msr
);
226 return *(u64
*)((char *)&__get_cpu_var(injectm
) + offset
);
232 static void mce_wrmsrl(u32 msr
, u64 v
)
234 if (__get_cpu_var(injectm
).finished
) {
235 int offset
= msr_to_offset(msr
);
237 *(u64
*)((char *)&__get_cpu_var(injectm
) + offset
) = v
;
243 int mce_available(struct cpuinfo_x86
*c
)
247 return cpu_has(c
, X86_FEATURE_MCE
) && cpu_has(c
, X86_FEATURE_MCA
);
250 static inline void mce_get_rip(struct mce
*m
, struct pt_regs
*regs
)
252 if (regs
&& (m
->mcgstatus
& MCG_STATUS_RIPV
)) {
260 /* Assume the RIP in the MSR is exact. Is this true? */
261 m
->mcgstatus
|= MCG_STATUS_EIPV
;
262 m
->ip
= mce_rdmsrl(rip_msr
);
268 * Poll for corrected events or events that happened before reset.
269 * Those are just logged through /dev/mcelog.
271 * This is executed in standard interrupt context.
273 void machine_check_poll(enum mcp_flags flags
, mce_banks_t
*b
)
280 m
.mcgstatus
= mce_rdmsrl(MSR_IA32_MCG_STATUS
);
281 for (i
= 0; i
< banks
; i
++) {
282 if (!bank
[i
] || !test_bit(i
, *b
))
291 m
.status
= mce_rdmsrl(MSR_IA32_MC0_STATUS
+ i
*4);
292 if (!(m
.status
& MCI_STATUS_VAL
))
296 * Uncorrected events are handled by the exception handler
297 * when it is enabled. But when the exception is disabled log
300 * TBD do the same check for MCI_STATUS_EN here?
302 if ((m
.status
& MCI_STATUS_UC
) && !(flags
& MCP_UC
))
305 if (m
.status
& MCI_STATUS_MISCV
)
306 m
.misc
= mce_rdmsrl(MSR_IA32_MC0_MISC
+ i
*4);
307 if (m
.status
& MCI_STATUS_ADDRV
)
308 m
.addr
= mce_rdmsrl(MSR_IA32_MC0_ADDR
+ i
*4);
310 if (!(flags
& MCP_TIMESTAMP
))
313 * Don't get the IP here because it's unlikely to
314 * have anything to do with the actual error location.
316 if (!(flags
& MCP_DONTLOG
)) {
318 add_taint(TAINT_MACHINE_CHECK
);
322 * Clear state for this bank.
324 mce_wrmsrl(MSR_IA32_MC0_STATUS
+4*i
, 0);
328 * Don't clear MCG_STATUS here because it's only defined for
334 EXPORT_SYMBOL_GPL(machine_check_poll
);
337 * The actual machine check handler. This only handles real
338 * exceptions when something got corrupted coming in through int 18.
340 * This is executed in NMI context not subject to normal locking rules. This
341 * implies that most kernel services cannot be safely used. Don't even
342 * think about putting a printk in there!
344 void do_machine_check(struct pt_regs
*regs
, long error_code
)
346 struct mce m
, panicm
;
347 int panicm_found
= 0;
351 * If no_way_out gets set, there is no safe way to recover from this
352 * MCE. If tolerant is cranked up, we'll try anyway.
356 * If kill_it gets set, there might be a way to recover from this
360 DECLARE_BITMAP(toclear
, MAX_NR_BANKS
);
362 atomic_inc(&mce_entry
);
364 __get_cpu_var(mce_exception_count
)++;
366 if (notify_die(DIE_NMI
, "machine check", regs
, error_code
,
367 18, SIGKILL
) == NOTIFY_STOP
)
374 m
.mcgstatus
= mce_rdmsrl(MSR_IA32_MCG_STATUS
);
376 /* if the restart IP is not valid, we're done for */
377 if (!(m
.mcgstatus
& MCG_STATUS_RIPV
))
383 for (i
= 0; i
< banks
; i
++) {
384 __clear_bit(i
, toclear
);
392 m
.status
= mce_rdmsrl(MSR_IA32_MC0_STATUS
+ i
*4);
393 if ((m
.status
& MCI_STATUS_VAL
) == 0)
397 * Non uncorrected errors are handled by machine_check_poll
400 if ((m
.status
& MCI_STATUS_UC
) == 0)
404 * Set taint even when machine check was not enabled.
406 add_taint(TAINT_MACHINE_CHECK
);
408 __set_bit(i
, toclear
);
410 if (m
.status
& MCI_STATUS_EN
) {
411 /* if PCC was set, there's no way out */
412 no_way_out
|= !!(m
.status
& MCI_STATUS_PCC
);
414 * If this error was uncorrectable and there was
415 * an overflow, we're in trouble. If no overflow,
416 * we might get away with just killing a task.
418 if (m
.status
& MCI_STATUS_UC
) {
419 if (tolerant
< 1 || m
.status
& MCI_STATUS_OVER
)
425 * Machine check event was not enabled. Clear, but
431 if (m
.status
& MCI_STATUS_MISCV
)
432 m
.misc
= mce_rdmsrl(MSR_IA32_MC0_MISC
+ i
*4);
433 if (m
.status
& MCI_STATUS_ADDRV
)
434 m
.addr
= mce_rdmsrl(MSR_IA32_MC0_ADDR
+ i
*4);
436 mce_get_rip(&m
, regs
);
440 * Did this bank cause the exception?
442 * Assume that the bank with uncorrectable errors did it,
443 * and that there is only a single one:
445 if ((m
.status
& MCI_STATUS_UC
) &&
446 (m
.status
& MCI_STATUS_EN
)) {
453 * If we didn't find an uncorrectable error, pick
454 * the last one (shouldn't happen, just being safe).
460 * If we have decided that we just CAN'T continue, and the user
461 * has not set tolerant to an insane level, give up and die.
463 if (no_way_out
&& tolerant
< 3)
464 mce_panic("Machine check", &panicm
, mcestart
);
467 * If the error seems to be unrecoverable, something should be
468 * done. Try to kill as little as possible. If we can kill just
469 * one task, do that. If the user has set the tolerance very
470 * high, don't try to do anything at all.
472 if (kill_it
&& tolerant
< 3) {
476 * If the EIPV bit is set, it means the saved IP is the
477 * instruction which caused the MCE.
479 if (m
.mcgstatus
& MCG_STATUS_EIPV
)
480 user_space
= panicm
.ip
&& (panicm
.cs
& 3);
483 * If we know that the error was in user space, send a
484 * SIGBUS. Otherwise, panic if tolerance is low.
486 * force_sig() takes an awful lot of locks and has a slight
487 * risk of deadlocking.
490 force_sig(SIGBUS
, current
);
491 } else if (panic_on_oops
|| tolerant
< 2) {
492 mce_panic("Uncorrected machine check",
497 /* notify userspace ASAP */
498 set_thread_flag(TIF_MCE_NOTIFY
);
500 /* the last thing we do is clear state */
501 for (i
= 0; i
< banks
; i
++) {
502 if (test_bit(i
, toclear
))
503 mce_wrmsrl(MSR_IA32_MC0_STATUS
+4*i
, 0);
505 mce_wrmsrl(MSR_IA32_MCG_STATUS
, 0);
507 atomic_dec(&mce_entry
);
510 EXPORT_SYMBOL_GPL(do_machine_check
);
512 #ifdef CONFIG_X86_MCE_INTEL
514 * mce_log_therm_throt_event - Logs the thermal throttling event to mcelog
515 * @cpu: The CPU on which the event occurred.
516 * @status: Event status information
518 * This function should be called by the thermal interrupt after the
519 * event has been processed and the decision was made to log the event
522 * The status parameter will be saved to the 'status' field of 'struct mce'
523 * and historically has been the register value of the
524 * MSR_IA32_THERMAL_STATUS (Intel) msr.
526 void mce_log_therm_throt_event(__u64 status
)
531 m
.bank
= MCE_THERMAL_BANK
;
535 #endif /* CONFIG_X86_MCE_INTEL */
538 * Periodic polling timer for "silent" machine check errors. If the
539 * poller finds an MCE, poll 2x faster. When the poller finds no more
540 * errors, poll 2x slower (up to check_interval seconds).
542 static int check_interval
= 5 * 60; /* 5 minutes */
544 static DEFINE_PER_CPU(int, next_interval
); /* in jiffies */
545 static DEFINE_PER_CPU(struct timer_list
, mce_timer
);
547 static void mcheck_timer(unsigned long data
)
549 struct timer_list
*t
= &per_cpu(mce_timer
, data
);
552 WARN_ON(smp_processor_id() != data
);
554 if (mce_available(¤t_cpu_data
)) {
555 machine_check_poll(MCP_TIMESTAMP
,
556 &__get_cpu_var(mce_poll_banks
));
560 * Alert userspace if needed. If we logged an MCE, reduce the
561 * polling interval, otherwise increase the polling interval.
563 n
= &__get_cpu_var(next_interval
);
564 if (mce_notify_user())
565 *n
= max(*n
/2, HZ
/100);
567 *n
= min(*n
*2, (int)round_jiffies_relative(check_interval
*HZ
));
569 t
->expires
= jiffies
+ *n
;
573 static void mce_do_trigger(struct work_struct
*work
)
575 call_usermodehelper(trigger
, trigger_argv
, NULL
, UMH_NO_WAIT
);
578 static DECLARE_WORK(mce_trigger_work
, mce_do_trigger
);
581 * Notify the user(s) about new machine check events.
582 * Can be called from interrupt context, but not from machine check/NMI
585 int mce_notify_user(void)
587 /* Not more than two messages every minute */
588 static DEFINE_RATELIMIT_STATE(ratelimit
, 60*HZ
, 2);
590 clear_thread_flag(TIF_MCE_NOTIFY
);
592 if (test_and_clear_bit(0, ¬ify_user
)) {
593 wake_up_interruptible(&mce_wait
);
596 * There is no risk of missing notifications because
597 * work_pending is always cleared before the function is
600 if (trigger
[0] && !work_pending(&mce_trigger_work
))
601 schedule_work(&mce_trigger_work
);
603 if (__ratelimit(&ratelimit
))
604 printk(KERN_INFO
"Machine check events logged\n");
610 EXPORT_SYMBOL_GPL(mce_notify_user
);
613 * Initialize Machine Checks for a CPU.
615 static int mce_cap_init(void)
620 rdmsrl(MSR_IA32_MCG_CAP
, cap
);
622 b
= cap
& MCG_BANKCNT_MASK
;
623 printk(KERN_INFO
"mce: CPU supports %d MCE banks\n", b
);
625 if (b
> MAX_NR_BANKS
) {
627 "MCE: Using only %u machine check banks out of %u\n",
632 /* Don't support asymmetric configurations today */
633 WARN_ON(banks
!= 0 && b
!= banks
);
636 bank
= kmalloc(banks
* sizeof(u64
), GFP_KERNEL
);
639 memset(bank
, 0xff, banks
* sizeof(u64
));
642 /* Use accurate RIP reporting if available. */
643 if ((cap
& MCG_EXT_P
) && MCG_EXT_CNT(cap
) >= 9)
644 rip_msr
= MSR_IA32_MCG_EIP
;
649 static void mce_init(void)
651 mce_banks_t all_banks
;
656 * Log the machine checks left over from the previous reset.
658 bitmap_fill(all_banks
, MAX_NR_BANKS
);
659 machine_check_poll(MCP_UC
|(!mce_bootlog
? MCP_DONTLOG
: 0), &all_banks
);
661 set_in_cr4(X86_CR4_MCE
);
663 rdmsrl(MSR_IA32_MCG_CAP
, cap
);
665 wrmsr(MSR_IA32_MCG_CTL
, 0xffffffff, 0xffffffff);
667 for (i
= 0; i
< banks
; i
++) {
668 if (skip_bank_init(i
))
670 wrmsrl(MSR_IA32_MC0_CTL
+4*i
, bank
[i
]);
671 wrmsrl(MSR_IA32_MC0_STATUS
+4*i
, 0);
675 /* Add per CPU specific workarounds here */
676 static void mce_cpu_quirks(struct cpuinfo_x86
*c
)
678 /* This should be disabled by the BIOS, but isn't always */
679 if (c
->x86_vendor
== X86_VENDOR_AMD
) {
680 if (c
->x86
== 15 && banks
> 4) {
682 * disable GART TBL walk error reporting, which
683 * trips off incorrectly with the IOMMU & 3ware
686 clear_bit(10, (unsigned long *)&bank
[4]);
688 if (c
->x86
<= 17 && mce_bootlog
< 0) {
690 * Lots of broken BIOS around that don't clear them
691 * by default and leave crap in there. Don't log:
696 * Various K7s with broken bank 0 around. Always disable
703 if (c
->x86_vendor
== X86_VENDOR_INTEL
) {
705 * SDM documents that on family 6 bank 0 should not be written
706 * because it aliases to another special BIOS controlled
708 * But it's not aliased anymore on model 0x1a+
709 * Don't ignore bank 0 completely because there could be a
710 * valid event later, merely don't write CTL0.
713 if (c
->x86
== 6 && c
->x86_model
< 0x1A)
714 __set_bit(0, &dont_init_banks
);
718 static void __cpuinit
mce_ancient_init(struct cpuinfo_x86
*c
)
722 switch (c
->x86_vendor
) {
723 case X86_VENDOR_INTEL
:
724 if (mce_p5_enabled())
725 intel_p5_mcheck_init(c
);
727 case X86_VENDOR_CENTAUR
:
728 winchip_mcheck_init(c
);
733 static void mce_cpu_features(struct cpuinfo_x86
*c
)
735 switch (c
->x86_vendor
) {
736 case X86_VENDOR_INTEL
:
737 mce_intel_feature_init(c
);
740 mce_amd_feature_init(c
);
747 static void mce_init_timer(void)
749 struct timer_list
*t
= &__get_cpu_var(mce_timer
);
750 int *n
= &__get_cpu_var(next_interval
);
752 *n
= check_interval
* HZ
;
755 setup_timer(t
, mcheck_timer
, smp_processor_id());
756 t
->expires
= round_jiffies(jiffies
+ *n
);
761 * Called for each booted CPU to set up machine checks.
762 * Must be called with preempt off:
764 void __cpuinit
mcheck_init(struct cpuinfo_x86
*c
)
771 if (!mce_available(c
))
774 if (mce_cap_init() < 0) {
780 machine_check_vector
= do_machine_check
;
788 * Character device to read and clear the MCE log.
791 static DEFINE_SPINLOCK(mce_state_lock
);
792 static int open_count
; /* #times opened */
793 static int open_exclu
; /* already open exclusive? */
795 static int mce_open(struct inode
*inode
, struct file
*file
)
797 spin_lock(&mce_state_lock
);
799 if (open_exclu
|| (open_count
&& (file
->f_flags
& O_EXCL
))) {
800 spin_unlock(&mce_state_lock
);
805 if (file
->f_flags
& O_EXCL
)
809 spin_unlock(&mce_state_lock
);
811 return nonseekable_open(inode
, file
);
814 static int mce_release(struct inode
*inode
, struct file
*file
)
816 spin_lock(&mce_state_lock
);
821 spin_unlock(&mce_state_lock
);
826 static void collect_tscs(void *data
)
828 unsigned long *cpu_tsc
= (unsigned long *)data
;
830 rdtscll(cpu_tsc
[smp_processor_id()]);
833 static DEFINE_MUTEX(mce_read_mutex
);
835 static ssize_t
mce_read(struct file
*filp
, char __user
*ubuf
, size_t usize
,
838 char __user
*buf
= ubuf
;
839 unsigned long *cpu_tsc
;
843 cpu_tsc
= kmalloc(nr_cpu_ids
* sizeof(long), GFP_KERNEL
);
847 mutex_lock(&mce_read_mutex
);
848 next
= rcu_dereference(mcelog
.next
);
850 /* Only supports full reads right now */
851 if (*off
!= 0 || usize
< MCE_LOG_LEN
*sizeof(struct mce
)) {
852 mutex_unlock(&mce_read_mutex
);
861 for (i
= prev
; i
< next
; i
++) {
862 unsigned long start
= jiffies
;
864 while (!mcelog
.entry
[i
].finished
) {
865 if (time_after_eq(jiffies
, start
+ 2)) {
866 memset(mcelog
.entry
+ i
, 0,
873 err
|= copy_to_user(buf
, mcelog
.entry
+ i
,
875 buf
+= sizeof(struct mce
);
880 memset(mcelog
.entry
+ prev
, 0,
881 (next
- prev
) * sizeof(struct mce
));
883 next
= cmpxchg(&mcelog
.next
, prev
, 0);
884 } while (next
!= prev
);
889 * Collect entries that were still getting written before the
892 on_each_cpu(collect_tscs
, cpu_tsc
, 1);
894 for (i
= next
; i
< MCE_LOG_LEN
; i
++) {
895 if (mcelog
.entry
[i
].finished
&&
896 mcelog
.entry
[i
].tsc
< cpu_tsc
[mcelog
.entry
[i
].cpu
]) {
897 err
|= copy_to_user(buf
, mcelog
.entry
+i
,
900 buf
+= sizeof(struct mce
);
901 memset(&mcelog
.entry
[i
], 0, sizeof(struct mce
));
904 mutex_unlock(&mce_read_mutex
);
907 return err
? -EFAULT
: buf
- ubuf
;
910 static unsigned int mce_poll(struct file
*file
, poll_table
*wait
)
912 poll_wait(file
, &mce_wait
, wait
);
913 if (rcu_dereference(mcelog
.next
))
914 return POLLIN
| POLLRDNORM
;
918 static long mce_ioctl(struct file
*f
, unsigned int cmd
, unsigned long arg
)
920 int __user
*p
= (int __user
*)arg
;
922 if (!capable(CAP_SYS_ADMIN
))
926 case MCE_GET_RECORD_LEN
:
927 return put_user(sizeof(struct mce
), p
);
928 case MCE_GET_LOG_LEN
:
929 return put_user(MCE_LOG_LEN
, p
);
930 case MCE_GETCLEAR_FLAGS
: {
934 flags
= mcelog
.flags
;
935 } while (cmpxchg(&mcelog
.flags
, flags
, 0) != flags
);
937 return put_user(flags
, p
);
944 /* Modified in mce-inject.c, so not static or const */
945 struct file_operations mce_chrdev_ops
= {
947 .release
= mce_release
,
950 .unlocked_ioctl
= mce_ioctl
,
952 EXPORT_SYMBOL_GPL(mce_chrdev_ops
);
954 static struct miscdevice mce_log_device
= {
961 * mce=off disables machine check
962 * mce=TOLERANCELEVEL (number, see above)
963 * mce=bootlog Log MCEs from before booting. Disabled by default on AMD.
964 * mce=nobootlog Don't log MCEs from before booting.
966 static int __init
mcheck_enable(char *str
)
972 if (!strcmp(str
, "off"))
974 else if (!strcmp(str
, "bootlog") || !strcmp(str
, "nobootlog"))
975 mce_bootlog
= (str
[0] == 'b');
976 else if (isdigit(str
[0]))
977 get_option(&str
, &tolerant
);
979 printk(KERN_INFO
"mce argument %s ignored. Please use /sys\n",
985 __setup("mce", mcheck_enable
);
992 * Disable machine checks on suspend and shutdown. We can't really handle
995 static int mce_disable(void)
999 for (i
= 0; i
< banks
; i
++) {
1000 if (!skip_bank_init(i
))
1001 wrmsrl(MSR_IA32_MC0_CTL
+ i
*4, 0);
1006 static int mce_suspend(struct sys_device
*dev
, pm_message_t state
)
1008 return mce_disable();
1011 static int mce_shutdown(struct sys_device
*dev
)
1013 return mce_disable();
1017 * On resume clear all MCE state. Don't want to see leftovers from the BIOS.
1018 * Only one CPU is active at this time, the others get re-added later using
1021 static int mce_resume(struct sys_device
*dev
)
1024 mce_cpu_features(¤t_cpu_data
);
1029 static void mce_cpu_restart(void *data
)
1031 del_timer_sync(&__get_cpu_var(mce_timer
));
1032 if (mce_available(¤t_cpu_data
))
1037 /* Reinit MCEs after user configuration changes */
1038 static void mce_restart(void)
1040 on_each_cpu(mce_cpu_restart
, NULL
, 1);
1043 static struct sysdev_class mce_sysclass
= {
1044 .suspend
= mce_suspend
,
1045 .shutdown
= mce_shutdown
,
1046 .resume
= mce_resume
,
1047 .name
= "machinecheck",
1050 DEFINE_PER_CPU(struct sys_device
, mce_dev
);
1053 void (*threshold_cpu_callback
)(unsigned long action
, unsigned int cpu
);
1055 static struct sysdev_attribute
*bank_attrs
;
1057 static ssize_t
show_bank(struct sys_device
*s
, struct sysdev_attribute
*attr
,
1060 u64 b
= bank
[attr
- bank_attrs
];
1062 return sprintf(buf
, "%llx\n", b
);
1065 static ssize_t
set_bank(struct sys_device
*s
, struct sysdev_attribute
*attr
,
1066 const char *buf
, size_t size
)
1070 if (strict_strtoull(buf
, 0, &new) < 0)
1073 bank
[attr
- bank_attrs
] = new;
1080 show_trigger(struct sys_device
*s
, struct sysdev_attribute
*attr
, char *buf
)
1082 strcpy(buf
, trigger
);
1084 return strlen(trigger
) + 1;
1087 static ssize_t
set_trigger(struct sys_device
*s
, struct sysdev_attribute
*attr
,
1088 const char *buf
, size_t siz
)
1093 strncpy(trigger
, buf
, sizeof(trigger
));
1094 trigger
[sizeof(trigger
)-1] = 0;
1095 len
= strlen(trigger
);
1096 p
= strchr(trigger
, '\n');
1104 static ssize_t
store_int_with_restart(struct sys_device
*s
,
1105 struct sysdev_attribute
*attr
,
1106 const char *buf
, size_t size
)
1108 ssize_t ret
= sysdev_store_int(s
, attr
, buf
, size
);
1113 static SYSDEV_ATTR(trigger
, 0644, show_trigger
, set_trigger
);
1114 static SYSDEV_INT_ATTR(tolerant
, 0644, tolerant
);
1116 static struct sysdev_ext_attribute attr_check_interval
= {
1117 _SYSDEV_ATTR(check_interval
, 0644, sysdev_show_int
,
1118 store_int_with_restart
),
1122 static struct sysdev_attribute
*mce_attrs
[] = {
1123 &attr_tolerant
.attr
, &attr_check_interval
.attr
, &attr_trigger
,
1127 static cpumask_var_t mce_dev_initialized
;
1129 /* Per cpu sysdev init. All of the cpus still share the same ctrl bank: */
1130 static __cpuinit
int mce_create_device(unsigned int cpu
)
1135 if (!mce_available(&boot_cpu_data
))
1138 memset(&per_cpu(mce_dev
, cpu
).kobj
, 0, sizeof(struct kobject
));
1139 per_cpu(mce_dev
, cpu
).id
= cpu
;
1140 per_cpu(mce_dev
, cpu
).cls
= &mce_sysclass
;
1142 err
= sysdev_register(&per_cpu(mce_dev
, cpu
));
1146 for (i
= 0; mce_attrs
[i
]; i
++) {
1147 err
= sysdev_create_file(&per_cpu(mce_dev
, cpu
), mce_attrs
[i
]);
1151 for (i
= 0; i
< banks
; i
++) {
1152 err
= sysdev_create_file(&per_cpu(mce_dev
, cpu
),
1157 cpumask_set_cpu(cpu
, mce_dev_initialized
);
1162 sysdev_remove_file(&per_cpu(mce_dev
, cpu
), &bank_attrs
[i
]);
1165 sysdev_remove_file(&per_cpu(mce_dev
, cpu
), mce_attrs
[i
]);
1167 sysdev_unregister(&per_cpu(mce_dev
, cpu
));
1172 static __cpuinit
void mce_remove_device(unsigned int cpu
)
1176 if (!cpumask_test_cpu(cpu
, mce_dev_initialized
))
1179 for (i
= 0; mce_attrs
[i
]; i
++)
1180 sysdev_remove_file(&per_cpu(mce_dev
, cpu
), mce_attrs
[i
]);
1182 for (i
= 0; i
< banks
; i
++)
1183 sysdev_remove_file(&per_cpu(mce_dev
, cpu
), &bank_attrs
[i
]);
1185 sysdev_unregister(&per_cpu(mce_dev
, cpu
));
1186 cpumask_clear_cpu(cpu
, mce_dev_initialized
);
1189 /* Make sure there are no machine checks on offlined CPUs. */
1190 static void mce_disable_cpu(void *h
)
1192 unsigned long action
= *(unsigned long *)h
;
1195 if (!mce_available(¤t_cpu_data
))
1197 if (!(action
& CPU_TASKS_FROZEN
))
1199 for (i
= 0; i
< banks
; i
++) {
1200 if (!skip_bank_init(i
))
1201 wrmsrl(MSR_IA32_MC0_CTL
+ i
*4, 0);
1205 static void mce_reenable_cpu(void *h
)
1207 unsigned long action
= *(unsigned long *)h
;
1210 if (!mce_available(¤t_cpu_data
))
1213 if (!(action
& CPU_TASKS_FROZEN
))
1215 for (i
= 0; i
< banks
; i
++) {
1216 if (!skip_bank_init(i
))
1217 wrmsrl(MSR_IA32_MC0_CTL
+ i
*4, bank
[i
]);
1221 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
1222 static int __cpuinit
1223 mce_cpu_callback(struct notifier_block
*nfb
, unsigned long action
, void *hcpu
)
1225 unsigned int cpu
= (unsigned long)hcpu
;
1226 struct timer_list
*t
= &per_cpu(mce_timer
, cpu
);
1230 case CPU_ONLINE_FROZEN
:
1231 mce_create_device(cpu
);
1232 if (threshold_cpu_callback
)
1233 threshold_cpu_callback(action
, cpu
);
1236 case CPU_DEAD_FROZEN
:
1237 if (threshold_cpu_callback
)
1238 threshold_cpu_callback(action
, cpu
);
1239 mce_remove_device(cpu
);
1241 case CPU_DOWN_PREPARE
:
1242 case CPU_DOWN_PREPARE_FROZEN
:
1244 smp_call_function_single(cpu
, mce_disable_cpu
, &action
, 1);
1246 case CPU_DOWN_FAILED
:
1247 case CPU_DOWN_FAILED_FROZEN
:
1248 t
->expires
= round_jiffies(jiffies
+
1249 __get_cpu_var(next_interval
));
1250 add_timer_on(t
, cpu
);
1251 smp_call_function_single(cpu
, mce_reenable_cpu
, &action
, 1);
1254 /* intentionally ignoring frozen here */
1255 cmci_rediscover(cpu
);
1261 static struct notifier_block mce_cpu_notifier __cpuinitdata
= {
1262 .notifier_call
= mce_cpu_callback
,
1265 static __init
int mce_init_banks(void)
1269 bank_attrs
= kzalloc(sizeof(struct sysdev_attribute
) * banks
,
1274 for (i
= 0; i
< banks
; i
++) {
1275 struct sysdev_attribute
*a
= &bank_attrs
[i
];
1277 a
->attr
.name
= kasprintf(GFP_KERNEL
, "bank%d", i
);
1281 a
->attr
.mode
= 0644;
1282 a
->show
= show_bank
;
1283 a
->store
= set_bank
;
1289 kfree(bank_attrs
[i
].attr
.name
);
1296 static __init
int mce_init_device(void)
1301 if (!mce_available(&boot_cpu_data
))
1304 alloc_cpumask_var(&mce_dev_initialized
, GFP_KERNEL
);
1306 err
= mce_init_banks();
1310 err
= sysdev_class_register(&mce_sysclass
);
1314 for_each_online_cpu(i
) {
1315 err
= mce_create_device(i
);
1320 register_hotcpu_notifier(&mce_cpu_notifier
);
1321 misc_register(&mce_log_device
);
1326 device_initcall(mce_init_device
);
1328 #else /* CONFIG_X86_OLD_MCE: */
1331 EXPORT_SYMBOL_GPL(nr_mce_banks
); /* non-fatal.o */
1333 /* This has to be run for each processor */
1334 void mcheck_init(struct cpuinfo_x86
*c
)
1336 if (mce_disabled
== 1)
1339 switch (c
->x86_vendor
) {
1340 case X86_VENDOR_AMD
:
1344 case X86_VENDOR_INTEL
:
1346 intel_p5_mcheck_init(c
);
1348 intel_p6_mcheck_init(c
);
1350 intel_p4_mcheck_init(c
);
1353 case X86_VENDOR_CENTAUR
:
1355 winchip_mcheck_init(c
);
1361 printk(KERN_INFO
"mce: CPU supports %d MCE banks\n", nr_mce_banks
);
1364 static int __init
mcheck_enable(char *str
)
1370 __setup("mce", mcheck_enable
);
1372 #endif /* CONFIG_X86_OLD_MCE */
1375 * Old style boot options parsing. Only for compatibility.
1377 static int __init
mcheck_disable(char *str
)
1382 __setup("nomce", mcheck_disable
);