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/interrupt.h>
14 #include <linux/ratelimit.h>
15 #include <linux/kallsyms.h>
16 #include <linux/rcupdate.h>
17 #include <linux/kobject.h>
18 #include <linux/uaccess.h>
19 #include <linux/kdebug.h>
20 #include <linux/kernel.h>
21 #include <linux/percpu.h>
22 #include <linux/string.h>
23 #include <linux/sysdev.h>
24 #include <linux/delay.h>
25 #include <linux/ctype.h>
26 #include <linux/sched.h>
27 #include <linux/sysfs.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/init.h>
31 #include <linux/kmod.h>
32 #include <linux/poll.h>
33 #include <linux/nmi.h>
34 #include <linux/cpu.h>
35 #include <linux/smp.h>
38 #include <linux/debugfs.h>
40 #include <asm/processor.h>
41 #include <asm/hw_irq.h>
48 #include "mce-internal.h"
50 static DEFINE_MUTEX(mce_read_mutex);
52 #define rcu_dereference_check_mce(p) \
53 rcu_dereference_check((p), \
54 rcu_read_lock_sched_held() || \
55 lockdep_is_held(&mce_read_mutex))
57 #define CREATE_TRACE_POINTS
58 #include <trace/events/mce.h>
60 int mce_disabled __read_mostly;
62 #define MISC_MCELOG_MINOR 227
64 #define SPINUNIT 100 /* 100ns */
68 DEFINE_PER_CPU(unsigned, mce_exception_count);
72 * 0: always panic on uncorrected errors, log corrected errors
73 * 1: panic or SIGBUS on uncorrected errors, log corrected errors
74 * 2: SIGBUS or log uncorrected errors (if possible), log corrected errors
75 * 3: never panic or SIGBUS, log all errors (for testing only)
77 static int tolerant __read_mostly = 1;
78 static int banks __read_mostly;
79 static int rip_msr __read_mostly;
80 static int mce_bootlog __read_mostly = -1;
81 static int monarch_timeout __read_mostly = -1;
82 static int mce_panic_timeout __read_mostly;
83 static int mce_dont_log_ce __read_mostly;
84 int mce_cmci_disabled __read_mostly;
85 int mce_ignore_ce __read_mostly;
86 int mce_ser __read_mostly;
88 struct mce_bank *mce_banks __read_mostly;
90 /* User mode helper program triggered by machine check event */
91 static unsigned long mce_need_notify;
92 static char mce_helper[128];
93 static char *mce_helper_argv[2] = { mce_helper, NULL };
95 static DECLARE_WAIT_QUEUE_HEAD(mce_wait);
96 static DEFINE_PER_CPU(struct mce, mces_seen);
97 static int cpu_missing;
100 * CPU/chipset specific EDAC code can register a notifier call here to print
101 * MCE errors in a human-readable form.
103 ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
104 EXPORT_SYMBOL_GPL(x86_mce_decoder_chain);
106 static int default_decode_mce(struct notifier_block *nb, unsigned long val,
109 pr_emerg("No human readable MCE decoding support on this CPU type.\n");
110 pr_emerg("Run the message through 'mcelog --ascii' to decode.\n");
115 static struct notifier_block mce_dec_nb = {
116 .notifier_call = default_decode_mce,
120 /* MCA banks polled by the period polling timer for corrected events */
121 DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
122 [0 ... BITS_TO_LONGS(MAX_NR_BANKS)-1] = ~0UL
125 static DEFINE_PER_CPU(struct work_struct, mce_work);
127 /* Do initial initialization of a struct mce */
128 void mce_setup(struct mce *m)
130 memset(m, 0, sizeof(struct mce));
131 m->cpu = m->extcpu = smp_processor_id();
133 /* We hope get_seconds stays lockless */
134 m->time = get_seconds();
135 m->cpuvendor = boot_cpu_data.x86_vendor;
136 m->cpuid = cpuid_eax(1);
138 m->socketid = cpu_data(m->extcpu).phys_proc_id;
140 m->apicid = cpu_data(m->extcpu).initial_apicid;
141 rdmsrl(MSR_IA32_MCG_CAP, m->mcgcap);
144 DEFINE_PER_CPU(struct mce, injectm);
145 EXPORT_PER_CPU_SYMBOL_GPL(injectm);
148 * Lockless MCE logging infrastructure.
149 * This avoids deadlocks on printk locks without having to break locks. Also
150 * separate MCEs from kernel messages to avoid bogus bug reports.
153 static struct mce_log mcelog = {
154 .signature = MCE_LOG_SIGNATURE,
156 .recordlen = sizeof(struct mce),
159 void mce_log(struct mce *mce)
161 unsigned next, entry;
163 /* Emit the trace record: */
164 trace_mce_record(mce);
169 entry = rcu_dereference_check_mce(mcelog.next);
172 * When the buffer fills up discard new entries.
173 * Assume that the earlier errors are the more
176 if (entry >= MCE_LOG_LEN) {
177 set_bit(MCE_OVERFLOW,
178 (unsigned long *)&mcelog.flags);
181 /* Old left over entry. Skip: */
182 if (mcelog.entry[entry].finished) {
190 if (cmpxchg(&mcelog.next, entry, next) == entry)
193 memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
195 mcelog.entry[entry].finished = 1;
199 set_bit(0, &mce_need_notify);
202 static void print_mce(struct mce *m)
204 pr_emerg("CPU %d: Machine Check Exception: %16Lx Bank %d: %016Lx\n",
205 m->extcpu, m->mcgstatus, m->bank, m->status);
208 pr_emerg("RIP%s %02x:<%016Lx> ",
209 !(m->mcgstatus & MCG_STATUS_EIPV) ? " !INEXACT!" : "",
212 if (m->cs == __KERNEL_CS)
213 print_symbol("{%s}", m->ip);
217 pr_emerg("TSC %llx ", m->tsc);
219 pr_cont("ADDR %llx ", m->addr);
221 pr_cont("MISC %llx ", m->misc);
224 pr_emerg("PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x\n",
225 m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid);
228 * Print out human-readable details about the MCE error,
229 * (if the CPU has an implementation for that)
231 atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
234 static void print_mce_head(void)
236 pr_emerg("\nHARDWARE ERROR\n");
239 static void print_mce_tail(void)
241 pr_emerg("This is not a software problem!\n");
244 #define PANIC_TIMEOUT 5 /* 5 seconds */
246 static atomic_t mce_paniced;
248 static int fake_panic;
249 static atomic_t mce_fake_paniced;
251 /* Panic in progress. Enable interrupts and wait for final IPI */
252 static void wait_for_panic(void)
254 long timeout = PANIC_TIMEOUT*USEC_PER_SEC;
258 while (timeout-- > 0)
260 if (panic_timeout == 0)
261 panic_timeout = mce_panic_timeout;
262 panic("Panicing machine check CPU died");
265 static void mce_panic(char *msg, struct mce *final, char *exp)
271 * Make sure only one CPU runs in machine check panic
273 if (atomic_inc_return(&mce_paniced) > 1)
280 /* Don't log too much for fake panic */
281 if (atomic_inc_return(&mce_fake_paniced) > 1)
285 /* First print corrected ones that are still unlogged */
286 for (i = 0; i < MCE_LOG_LEN; i++) {
287 struct mce *m = &mcelog.entry[i];
288 if (!(m->status & MCI_STATUS_VAL))
290 if (!(m->status & MCI_STATUS_UC)) {
293 apei_err = apei_write_mce(m);
296 /* Now print uncorrected but with the final one last */
297 for (i = 0; i < MCE_LOG_LEN; i++) {
298 struct mce *m = &mcelog.entry[i];
299 if (!(m->status & MCI_STATUS_VAL))
301 if (!(m->status & MCI_STATUS_UC))
303 if (!final || memcmp(m, final, sizeof(struct mce))) {
306 apei_err = apei_write_mce(m);
312 apei_err = apei_write_mce(final);
315 printk(KERN_EMERG "Some CPUs didn't answer in synchronization\n");
318 printk(KERN_EMERG "Machine check: %s\n", exp);
320 if (panic_timeout == 0)
321 panic_timeout = mce_panic_timeout;
324 printk(KERN_EMERG "Fake kernel panic: %s\n", msg);
327 /* Support code for software error injection */
329 static int msr_to_offset(u32 msr)
331 unsigned bank = __get_cpu_var(injectm.bank);
334 return offsetof(struct mce, ip);
335 if (msr == MSR_IA32_MCx_STATUS(bank))
336 return offsetof(struct mce, status);
337 if (msr == MSR_IA32_MCx_ADDR(bank))
338 return offsetof(struct mce, addr);
339 if (msr == MSR_IA32_MCx_MISC(bank))
340 return offsetof(struct mce, misc);
341 if (msr == MSR_IA32_MCG_STATUS)
342 return offsetof(struct mce, mcgstatus);
346 /* MSR access wrappers used for error injection */
347 static u64 mce_rdmsrl(u32 msr)
351 if (__get_cpu_var(injectm).finished) {
352 int offset = msr_to_offset(msr);
356 return *(u64 *)((char *)&__get_cpu_var(injectm) + offset);
359 if (rdmsrl_safe(msr, &v)) {
360 WARN_ONCE(1, "mce: Unable to read msr %d!\n", msr);
362 * Return zero in case the access faulted. This should
363 * not happen normally but can happen if the CPU does
364 * something weird, or if the code is buggy.
372 static void mce_wrmsrl(u32 msr, u64 v)
374 if (__get_cpu_var(injectm).finished) {
375 int offset = msr_to_offset(msr);
378 *(u64 *)((char *)&__get_cpu_var(injectm) + offset) = v;
385 * Simple lockless ring to communicate PFNs from the exception handler with the
386 * process context work function. This is vastly simplified because there's
387 * only a single reader and a single writer.
389 #define MCE_RING_SIZE 16 /* we use one entry less */
392 unsigned short start;
394 unsigned long ring[MCE_RING_SIZE];
396 static DEFINE_PER_CPU(struct mce_ring, mce_ring);
398 /* Runs with CPU affinity in workqueue */
399 static int mce_ring_empty(void)
401 struct mce_ring *r = &__get_cpu_var(mce_ring);
403 return r->start == r->end;
406 static int mce_ring_get(unsigned long *pfn)
413 r = &__get_cpu_var(mce_ring);
414 if (r->start == r->end)
416 *pfn = r->ring[r->start];
417 r->start = (r->start + 1) % MCE_RING_SIZE;
424 /* Always runs in MCE context with preempt off */
425 static int mce_ring_add(unsigned long pfn)
427 struct mce_ring *r = &__get_cpu_var(mce_ring);
430 next = (r->end + 1) % MCE_RING_SIZE;
431 if (next == r->start)
433 r->ring[r->end] = pfn;
439 int mce_available(struct cpuinfo_x86 *c)
443 return cpu_has(c, X86_FEATURE_MCE) && cpu_has(c, X86_FEATURE_MCA);
446 static void mce_schedule_work(void)
448 if (!mce_ring_empty()) {
449 struct work_struct *work = &__get_cpu_var(mce_work);
450 if (!work_pending(work))
456 * Get the address of the instruction at the time of the machine check
459 static inline void mce_get_rip(struct mce *m, struct pt_regs *regs)
462 if (regs && (m->mcgstatus & (MCG_STATUS_RIPV|MCG_STATUS_EIPV))) {
470 m->ip = mce_rdmsrl(rip_msr);
473 #ifdef CONFIG_X86_LOCAL_APIC
475 * Called after interrupts have been reenabled again
476 * when a MCE happened during an interrupts off region
479 asmlinkage void smp_mce_self_interrupt(struct pt_regs *regs)
490 static void mce_report_event(struct pt_regs *regs)
492 if (regs->flags & (X86_VM_MASK|X86_EFLAGS_IF)) {
495 * Triggering the work queue here is just an insurance
496 * policy in case the syscall exit notify handler
497 * doesn't run soon enough or ends up running on the
498 * wrong CPU (can happen when audit sleeps)
504 #ifdef CONFIG_X86_LOCAL_APIC
506 * Without APIC do not notify. The event will be picked
513 * When interrupts are disabled we cannot use
514 * kernel services safely. Trigger an self interrupt
515 * through the APIC to instead do the notification
516 * after interrupts are reenabled again.
518 apic->send_IPI_self(MCE_SELF_VECTOR);
521 * Wait for idle afterwards again so that we don't leave the
522 * APIC in a non idle state because the normal APIC writes
525 apic_wait_icr_idle();
529 DEFINE_PER_CPU(unsigned, mce_poll_count);
532 * Poll for corrected events or events that happened before reset.
533 * Those are just logged through /dev/mcelog.
535 * This is executed in standard interrupt context.
537 * Note: spec recommends to panic for fatal unsignalled
538 * errors here. However this would be quite problematic --
539 * we would need to reimplement the Monarch handling and
540 * it would mess up the exclusion between exception handler
541 * and poll hander -- * so we skip this for now.
542 * These cases should not happen anyways, or only when the CPU
543 * is already totally * confused. In this case it's likely it will
544 * not fully execute the machine check handler either.
546 void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
551 percpu_inc(mce_poll_count);
555 m.mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
556 for (i = 0; i < banks; i++) {
557 if (!mce_banks[i].ctl || !test_bit(i, *b))
566 m.status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i));
567 if (!(m.status & MCI_STATUS_VAL))
571 * Uncorrected or signalled events are handled by the exception
572 * handler when it is enabled, so don't process those here.
574 * TBD do the same check for MCI_STATUS_EN here?
576 if (!(flags & MCP_UC) &&
577 (m.status & (mce_ser ? MCI_STATUS_S : MCI_STATUS_UC)))
580 if (m.status & MCI_STATUS_MISCV)
581 m.misc = mce_rdmsrl(MSR_IA32_MCx_MISC(i));
582 if (m.status & MCI_STATUS_ADDRV)
583 m.addr = mce_rdmsrl(MSR_IA32_MCx_ADDR(i));
585 if (!(flags & MCP_TIMESTAMP))
588 * Don't get the IP here because it's unlikely to
589 * have anything to do with the actual error location.
591 if (!(flags & MCP_DONTLOG) && !mce_dont_log_ce) {
593 add_taint(TAINT_MACHINE_CHECK);
597 * Clear state for this bank.
599 mce_wrmsrl(MSR_IA32_MCx_STATUS(i), 0);
603 * Don't clear MCG_STATUS here because it's only defined for
609 EXPORT_SYMBOL_GPL(machine_check_poll);
612 * Do a quick check if any of the events requires a panic.
613 * This decides if we keep the events around or clear them.
615 static int mce_no_way_out(struct mce *m, char **msg)
619 for (i = 0; i < banks; i++) {
620 m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i));
621 if (mce_severity(m, tolerant, msg) >= MCE_PANIC_SEVERITY)
628 * Variable to establish order between CPUs while scanning.
629 * Each CPU spins initially until executing is equal its number.
631 static atomic_t mce_executing;
634 * Defines order of CPUs on entry. First CPU becomes Monarch.
636 static atomic_t mce_callin;
639 * Check if a timeout waiting for other CPUs happened.
641 static int mce_timed_out(u64 *t)
644 * The others already did panic for some reason.
645 * Bail out like in a timeout.
646 * rmb() to tell the compiler that system_state
647 * might have been modified by someone else.
650 if (atomic_read(&mce_paniced))
652 if (!monarch_timeout)
654 if ((s64)*t < SPINUNIT) {
655 /* CHECKME: Make panic default for 1 too? */
657 mce_panic("Timeout synchronizing machine check over CPUs",
664 touch_nmi_watchdog();
669 * The Monarch's reign. The Monarch is the CPU who entered
670 * the machine check handler first. It waits for the others to
671 * raise the exception too and then grades them. When any
672 * error is fatal panic. Only then let the others continue.
674 * The other CPUs entering the MCE handler will be controlled by the
675 * Monarch. They are called Subjects.
677 * This way we prevent any potential data corruption in a unrecoverable case
678 * and also makes sure always all CPU's errors are examined.
680 * Also this detects the case of a machine check event coming from outer
681 * space (not detected by any CPUs) In this case some external agent wants
682 * us to shut down, so panic too.
684 * The other CPUs might still decide to panic if the handler happens
685 * in a unrecoverable place, but in this case the system is in a semi-stable
686 * state and won't corrupt anything by itself. It's ok to let the others
687 * continue for a bit first.
689 * All the spin loops have timeouts; when a timeout happens a CPU
690 * typically elects itself to be Monarch.
692 static void mce_reign(void)
695 struct mce *m = NULL;
696 int global_worst = 0;
701 * This CPU is the Monarch and the other CPUs have run
702 * through their handlers.
703 * Grade the severity of the errors of all the CPUs.
705 for_each_possible_cpu(cpu) {
706 int severity = mce_severity(&per_cpu(mces_seen, cpu), tolerant,
708 if (severity > global_worst) {
710 global_worst = severity;
711 m = &per_cpu(mces_seen, cpu);
716 * Cannot recover? Panic here then.
717 * This dumps all the mces in the log buffer and stops the
720 if (m && global_worst >= MCE_PANIC_SEVERITY && tolerant < 3)
721 mce_panic("Fatal Machine check", m, msg);
724 * For UC somewhere we let the CPU who detects it handle it.
725 * Also must let continue the others, otherwise the handling
726 * CPU could deadlock on a lock.
730 * No machine check event found. Must be some external
731 * source or one CPU is hung. Panic.
733 if (global_worst <= MCE_KEEP_SEVERITY && tolerant < 3)
734 mce_panic("Machine check from unknown source", NULL, NULL);
737 * Now clear all the mces_seen so that they don't reappear on
740 for_each_possible_cpu(cpu)
741 memset(&per_cpu(mces_seen, cpu), 0, sizeof(struct mce));
744 static atomic_t global_nwo;
747 * Start of Monarch synchronization. This waits until all CPUs have
748 * entered the exception handler and then determines if any of them
749 * saw a fatal event that requires panic. Then it executes them
750 * in the entry order.
751 * TBD double check parallel CPU hotunplug
753 static int mce_start(int *no_way_out)
756 int cpus = num_online_cpus();
757 u64 timeout = (u64)monarch_timeout * NSEC_PER_USEC;
762 atomic_add(*no_way_out, &global_nwo);
764 * global_nwo should be updated before mce_callin
767 order = atomic_inc_return(&mce_callin);
772 while (atomic_read(&mce_callin) != cpus) {
773 if (mce_timed_out(&timeout)) {
774 atomic_set(&global_nwo, 0);
781 * mce_callin should be read before global_nwo
787 * Monarch: Starts executing now, the others wait.
789 atomic_set(&mce_executing, 1);
792 * Subject: Now start the scanning loop one by one in
793 * the original callin order.
794 * This way when there are any shared banks it will be
795 * only seen by one CPU before cleared, avoiding duplicates.
797 while (atomic_read(&mce_executing) < order) {
798 if (mce_timed_out(&timeout)) {
799 atomic_set(&global_nwo, 0);
807 * Cache the global no_way_out state.
809 *no_way_out = atomic_read(&global_nwo);
815 * Synchronize between CPUs after main scanning loop.
816 * This invokes the bulk of the Monarch processing.
818 static int mce_end(int order)
821 u64 timeout = (u64)monarch_timeout * NSEC_PER_USEC;
829 * Allow others to run.
831 atomic_inc(&mce_executing);
834 /* CHECKME: Can this race with a parallel hotplug? */
835 int cpus = num_online_cpus();
838 * Monarch: Wait for everyone to go through their scanning
841 while (atomic_read(&mce_executing) <= cpus) {
842 if (mce_timed_out(&timeout))
852 * Subject: Wait for Monarch to finish.
854 while (atomic_read(&mce_executing) != 0) {
855 if (mce_timed_out(&timeout))
861 * Don't reset anything. That's done by the Monarch.
867 * Reset all global state.
870 atomic_set(&global_nwo, 0);
871 atomic_set(&mce_callin, 0);
875 * Let others run again.
877 atomic_set(&mce_executing, 0);
882 * Check if the address reported by the CPU is in a format we can parse.
883 * It would be possible to add code for most other cases, but all would
884 * be somewhat complicated (e.g. segment offset would require an instruction
885 * parser). So only support physical addresses upto page granuality for now.
887 static int mce_usable_address(struct mce *m)
889 if (!(m->status & MCI_STATUS_MISCV) || !(m->status & MCI_STATUS_ADDRV))
891 if ((m->misc & 0x3f) > PAGE_SHIFT)
893 if (((m->misc >> 6) & 7) != MCM_ADDR_PHYS)
898 static void mce_clear_state(unsigned long *toclear)
902 for (i = 0; i < banks; i++) {
903 if (test_bit(i, toclear))
904 mce_wrmsrl(MSR_IA32_MCx_STATUS(i), 0);
909 * The actual machine check handler. This only handles real
910 * exceptions when something got corrupted coming in through int 18.
912 * This is executed in NMI context not subject to normal locking rules. This
913 * implies that most kernel services cannot be safely used. Don't even
914 * think about putting a printk in there!
916 * On Intel systems this is entered on all CPUs in parallel through
917 * MCE broadcast. However some CPUs might be broken beyond repair,
918 * so be always careful when synchronizing with others.
920 void do_machine_check(struct pt_regs *regs, long error_code)
922 struct mce m, *final;
927 * Establish sequential order between the CPUs entering the machine
932 * If no_way_out gets set, there is no safe way to recover from this
933 * MCE. If tolerant is cranked up, we'll try anyway.
937 * If kill_it gets set, there might be a way to recover from this
941 DECLARE_BITMAP(toclear, MAX_NR_BANKS);
942 char *msg = "Unknown";
944 atomic_inc(&mce_entry);
946 percpu_inc(mce_exception_count);
948 if (notify_die(DIE_NMI, "machine check", regs, error_code,
949 18, SIGKILL) == NOTIFY_STOP)
956 m.mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
957 final = &__get_cpu_var(mces_seen);
960 no_way_out = mce_no_way_out(&m, &msg);
965 * When no restart IP must always kill or panic.
967 if (!(m.mcgstatus & MCG_STATUS_RIPV))
971 * Go through all the banks in exclusion of the other CPUs.
972 * This way we don't report duplicated events on shared banks
973 * because the first one to see it will clear it.
975 order = mce_start(&no_way_out);
976 for (i = 0; i < banks; i++) {
977 __clear_bit(i, toclear);
978 if (!mce_banks[i].ctl)
985 m.status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i));
986 if ((m.status & MCI_STATUS_VAL) == 0)
990 * Non uncorrected or non signaled errors are handled by
991 * machine_check_poll. Leave them alone, unless this panics.
993 if (!(m.status & (mce_ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
998 * Set taint even when machine check was not enabled.
1000 add_taint(TAINT_MACHINE_CHECK);
1002 severity = mce_severity(&m, tolerant, NULL);
1005 * When machine check was for corrected handler don't touch,
1006 * unless we're panicing.
1008 if (severity == MCE_KEEP_SEVERITY && !no_way_out)
1010 __set_bit(i, toclear);
1011 if (severity == MCE_NO_SEVERITY) {
1013 * Machine check event was not enabled. Clear, but
1020 * Kill on action required.
1022 if (severity == MCE_AR_SEVERITY)
1025 if (m.status & MCI_STATUS_MISCV)
1026 m.misc = mce_rdmsrl(MSR_IA32_MCx_MISC(i));
1027 if (m.status & MCI_STATUS_ADDRV)
1028 m.addr = mce_rdmsrl(MSR_IA32_MCx_ADDR(i));
1031 * Action optional error. Queue address for later processing.
1032 * When the ring overflows we just ignore the AO error.
1033 * RED-PEN add some logging mechanism when
1034 * usable_address or mce_add_ring fails.
1035 * RED-PEN don't ignore overflow for tolerant == 0
1037 if (severity == MCE_AO_SEVERITY && mce_usable_address(&m))
1038 mce_ring_add(m.addr >> PAGE_SHIFT);
1040 mce_get_rip(&m, regs);
1043 if (severity > worst) {
1050 mce_clear_state(toclear);
1053 * Do most of the synchronization with other CPUs.
1054 * When there's any problem use only local no_way_out state.
1056 if (mce_end(order) < 0)
1057 no_way_out = worst >= MCE_PANIC_SEVERITY;
1060 * If we have decided that we just CAN'T continue, and the user
1061 * has not set tolerant to an insane level, give up and die.
1063 * This is mainly used in the case when the system doesn't
1064 * support MCE broadcasting or it has been disabled.
1066 if (no_way_out && tolerant < 3)
1067 mce_panic("Fatal machine check on current CPU", final, msg);
1070 * If the error seems to be unrecoverable, something should be
1071 * done. Try to kill as little as possible. If we can kill just
1072 * one task, do that. If the user has set the tolerance very
1073 * high, don't try to do anything at all.
1076 if (kill_it && tolerant < 3)
1077 force_sig(SIGBUS, current);
1079 /* notify userspace ASAP */
1080 set_thread_flag(TIF_MCE_NOTIFY);
1083 mce_report_event(regs);
1084 mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
1086 atomic_dec(&mce_entry);
1089 EXPORT_SYMBOL_GPL(do_machine_check);
1091 /* dummy to break dependency. actual code is in mm/memory-failure.c */
1092 void __attribute__((weak)) memory_failure(unsigned long pfn, int vector)
1094 printk(KERN_ERR "Action optional memory failure at %lx ignored\n", pfn);
1098 * Called after mce notification in process context. This code
1099 * is allowed to sleep. Call the high level VM handler to process
1100 * any corrupted pages.
1101 * Assume that the work queue code only calls this one at a time
1103 * Note we don't disable preemption, so this code might run on the wrong
1104 * CPU. In this case the event is picked up by the scheduled work queue.
1105 * This is merely a fast path to expedite processing in some common
1108 void mce_notify_process(void)
1112 while (mce_ring_get(&pfn))
1113 memory_failure(pfn, MCE_VECTOR);
1116 static void mce_process_work(struct work_struct *dummy)
1118 mce_notify_process();
1121 #ifdef CONFIG_X86_MCE_INTEL
1123 * mce_log_therm_throt_event - Logs the thermal throttling event to mcelog
1124 * @cpu: The CPU on which the event occurred.
1125 * @status: Event status information
1127 * This function should be called by the thermal interrupt after the
1128 * event has been processed and the decision was made to log the event
1131 * The status parameter will be saved to the 'status' field of 'struct mce'
1132 * and historically has been the register value of the
1133 * MSR_IA32_THERMAL_STATUS (Intel) msr.
1135 void mce_log_therm_throt_event(__u64 status)
1140 m.bank = MCE_THERMAL_BANK;
1144 #endif /* CONFIG_X86_MCE_INTEL */
1147 * Periodic polling timer for "silent" machine check errors. If the
1148 * poller finds an MCE, poll 2x faster. When the poller finds no more
1149 * errors, poll 2x slower (up to check_interval seconds).
1151 static int check_interval = 5 * 60; /* 5 minutes */
1153 static DEFINE_PER_CPU(int, mce_next_interval); /* in jiffies */
1154 static DEFINE_PER_CPU(struct timer_list, mce_timer);
1156 static void mce_start_timer(unsigned long data)
1158 struct timer_list *t = &per_cpu(mce_timer, data);
1161 WARN_ON(smp_processor_id() != data);
1163 if (mce_available(¤t_cpu_data)) {
1164 machine_check_poll(MCP_TIMESTAMP,
1165 &__get_cpu_var(mce_poll_banks));
1169 * Alert userspace if needed. If we logged an MCE, reduce the
1170 * polling interval, otherwise increase the polling interval.
1172 n = &__get_cpu_var(mce_next_interval);
1173 if (mce_notify_irq())
1174 *n = max(*n/2, HZ/100);
1176 *n = min(*n*2, (int)round_jiffies_relative(check_interval*HZ));
1178 t->expires = jiffies + *n;
1179 add_timer_on(t, smp_processor_id());
1182 static void mce_do_trigger(struct work_struct *work)
1184 call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT);
1187 static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
1190 * Notify the user(s) about new machine check events.
1191 * Can be called from interrupt context, but not from machine check/NMI
1194 int mce_notify_irq(void)
1196 /* Not more than two messages every minute */
1197 static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
1199 clear_thread_flag(TIF_MCE_NOTIFY);
1201 if (test_and_clear_bit(0, &mce_need_notify)) {
1202 wake_up_interruptible(&mce_wait);
1205 * There is no risk of missing notifications because
1206 * work_pending is always cleared before the function is
1209 if (mce_helper[0] && !work_pending(&mce_trigger_work))
1210 schedule_work(&mce_trigger_work);
1212 if (__ratelimit(&ratelimit))
1213 printk(KERN_INFO "Machine check events logged\n");
1219 EXPORT_SYMBOL_GPL(mce_notify_irq);
1221 static int __cpuinit __mcheck_cpu_mce_banks_init(void)
1225 mce_banks = kzalloc(banks * sizeof(struct mce_bank), GFP_KERNEL);
1228 for (i = 0; i < banks; i++) {
1229 struct mce_bank *b = &mce_banks[i];
1238 * Initialize Machine Checks for a CPU.
1240 static int __cpuinit __mcheck_cpu_cap_init(void)
1245 rdmsrl(MSR_IA32_MCG_CAP, cap);
1247 b = cap & MCG_BANKCNT_MASK;
1249 printk(KERN_INFO "mce: CPU supports %d MCE banks\n", b);
1251 if (b > MAX_NR_BANKS) {
1253 "MCE: Using only %u machine check banks out of %u\n",
1258 /* Don't support asymmetric configurations today */
1259 WARN_ON(banks != 0 && b != banks);
1262 int err = __mcheck_cpu_mce_banks_init();
1268 /* Use accurate RIP reporting if available. */
1269 if ((cap & MCG_EXT_P) && MCG_EXT_CNT(cap) >= 9)
1270 rip_msr = MSR_IA32_MCG_EIP;
1272 if (cap & MCG_SER_P)
1278 static void __mcheck_cpu_init_generic(void)
1280 mce_banks_t all_banks;
1285 * Log the machine checks left over from the previous reset.
1287 bitmap_fill(all_banks, MAX_NR_BANKS);
1288 machine_check_poll(MCP_UC|(!mce_bootlog ? MCP_DONTLOG : 0), &all_banks);
1290 set_in_cr4(X86_CR4_MCE);
1292 rdmsrl(MSR_IA32_MCG_CAP, cap);
1293 if (cap & MCG_CTL_P)
1294 wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
1296 for (i = 0; i < banks; i++) {
1297 struct mce_bank *b = &mce_banks[i];
1301 wrmsrl(MSR_IA32_MCx_CTL(i), b->ctl);
1302 wrmsrl(MSR_IA32_MCx_STATUS(i), 0);
1306 /* Add per CPU specific workarounds here */
1307 static int __cpuinit __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
1309 if (c->x86_vendor == X86_VENDOR_UNKNOWN) {
1310 pr_info("MCE: unknown CPU type - not enabling MCE support.\n");
1314 /* This should be disabled by the BIOS, but isn't always */
1315 if (c->x86_vendor == X86_VENDOR_AMD) {
1316 if (c->x86 == 15 && banks > 4) {
1318 * disable GART TBL walk error reporting, which
1319 * trips off incorrectly with the IOMMU & 3ware
1322 clear_bit(10, (unsigned long *)&mce_banks[4].ctl);
1324 if (c->x86 <= 17 && mce_bootlog < 0) {
1326 * Lots of broken BIOS around that don't clear them
1327 * by default and leave crap in there. Don't log:
1332 * Various K7s with broken bank 0 around. Always disable
1335 if (c->x86 == 6 && banks > 0)
1336 mce_banks[0].ctl = 0;
1339 if (c->x86_vendor == X86_VENDOR_INTEL) {
1341 * SDM documents that on family 6 bank 0 should not be written
1342 * because it aliases to another special BIOS controlled
1344 * But it's not aliased anymore on model 0x1a+
1345 * Don't ignore bank 0 completely because there could be a
1346 * valid event later, merely don't write CTL0.
1349 if (c->x86 == 6 && c->x86_model < 0x1A && banks > 0)
1350 mce_banks[0].init = 0;
1353 * All newer Intel systems support MCE broadcasting. Enable
1354 * synchronization with a one second timeout.
1356 if ((c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xe)) &&
1357 monarch_timeout < 0)
1358 monarch_timeout = USEC_PER_SEC;
1361 * There are also broken BIOSes on some Pentium M and
1364 if (c->x86 == 6 && c->x86_model <= 13 && mce_bootlog < 0)
1367 if (monarch_timeout < 0)
1368 monarch_timeout = 0;
1369 if (mce_bootlog != 0)
1370 mce_panic_timeout = 30;
1375 static void __cpuinit __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
1379 switch (c->x86_vendor) {
1380 case X86_VENDOR_INTEL:
1381 intel_p5_mcheck_init(c);
1383 case X86_VENDOR_CENTAUR:
1384 winchip_mcheck_init(c);
1389 static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
1391 switch (c->x86_vendor) {
1392 case X86_VENDOR_INTEL:
1393 mce_intel_feature_init(c);
1395 case X86_VENDOR_AMD:
1396 mce_amd_feature_init(c);
1403 static void __mcheck_cpu_init_timer(void)
1405 struct timer_list *t = &__get_cpu_var(mce_timer);
1406 int *n = &__get_cpu_var(mce_next_interval);
1408 setup_timer(t, mce_start_timer, smp_processor_id());
1413 *n = check_interval * HZ;
1416 t->expires = round_jiffies(jiffies + *n);
1417 add_timer_on(t, smp_processor_id());
1420 /* Handle unconfigured int18 (should never happen) */
1421 static void unexpected_machine_check(struct pt_regs *regs, long error_code)
1423 printk(KERN_ERR "CPU#%d: Unexpected int18 (Machine Check).\n",
1424 smp_processor_id());
1427 /* Call the installed machine check handler for this CPU setup. */
1428 void (*machine_check_vector)(struct pt_regs *, long error_code) =
1429 unexpected_machine_check;
1432 * Called for each booted CPU to set up machine checks.
1433 * Must be called with preempt off:
1435 void __cpuinit mcheck_cpu_init(struct cpuinfo_x86 *c)
1440 __mcheck_cpu_ancient_init(c);
1442 if (!mce_available(c))
1445 if (__mcheck_cpu_cap_init() < 0 || __mcheck_cpu_apply_quirks(c) < 0) {
1450 machine_check_vector = do_machine_check;
1452 __mcheck_cpu_init_generic();
1453 __mcheck_cpu_init_vendor(c);
1454 __mcheck_cpu_init_timer();
1455 INIT_WORK(&__get_cpu_var(mce_work), mce_process_work);
1460 * Character device to read and clear the MCE log.
1463 static DEFINE_SPINLOCK(mce_state_lock);
1464 static int open_count; /* #times opened */
1465 static int open_exclu; /* already open exclusive? */
1467 static int mce_open(struct inode *inode, struct file *file)
1469 spin_lock(&mce_state_lock);
1471 if (open_exclu || (open_count && (file->f_flags & O_EXCL))) {
1472 spin_unlock(&mce_state_lock);
1477 if (file->f_flags & O_EXCL)
1481 spin_unlock(&mce_state_lock);
1483 return nonseekable_open(inode, file);
1486 static int mce_release(struct inode *inode, struct file *file)
1488 spin_lock(&mce_state_lock);
1493 spin_unlock(&mce_state_lock);
1498 static void collect_tscs(void *data)
1500 unsigned long *cpu_tsc = (unsigned long *)data;
1502 rdtscll(cpu_tsc[smp_processor_id()]);
1505 static int mce_apei_read_done;
1507 /* Collect MCE record of previous boot in persistent storage via APEI ERST. */
1508 static int __mce_read_apei(char __user **ubuf, size_t usize)
1514 if (usize < sizeof(struct mce))
1517 rc = apei_read_mce(&m, &record_id);
1518 /* Error or no more MCE record */
1520 mce_apei_read_done = 1;
1524 if (copy_to_user(*ubuf, &m, sizeof(struct mce)))
1527 * In fact, we should have cleared the record after that has
1528 * been flushed to the disk or sent to network in
1529 * /sbin/mcelog, but we have no interface to support that now,
1530 * so just clear it to avoid duplication.
1532 rc = apei_clear_mce(record_id);
1534 mce_apei_read_done = 1;
1537 *ubuf += sizeof(struct mce);
1542 static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize,
1545 char __user *buf = ubuf;
1546 unsigned long *cpu_tsc;
1547 unsigned prev, next;
1550 cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
1554 mutex_lock(&mce_read_mutex);
1556 if (!mce_apei_read_done) {
1557 err = __mce_read_apei(&buf, usize);
1558 if (err || buf != ubuf)
1562 next = rcu_dereference_check_mce(mcelog.next);
1564 /* Only supports full reads right now */
1566 if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce))
1572 for (i = prev; i < next; i++) {
1573 unsigned long start = jiffies;
1575 while (!mcelog.entry[i].finished) {
1576 if (time_after_eq(jiffies, start + 2)) {
1577 memset(mcelog.entry + i, 0,
1578 sizeof(struct mce));
1584 err |= copy_to_user(buf, mcelog.entry + i,
1585 sizeof(struct mce));
1586 buf += sizeof(struct mce);
1591 memset(mcelog.entry + prev, 0,
1592 (next - prev) * sizeof(struct mce));
1594 next = cmpxchg(&mcelog.next, prev, 0);
1595 } while (next != prev);
1597 synchronize_sched();
1600 * Collect entries that were still getting written before the
1603 on_each_cpu(collect_tscs, cpu_tsc, 1);
1605 for (i = next; i < MCE_LOG_LEN; i++) {
1606 if (mcelog.entry[i].finished &&
1607 mcelog.entry[i].tsc < cpu_tsc[mcelog.entry[i].cpu]) {
1608 err |= copy_to_user(buf, mcelog.entry+i,
1609 sizeof(struct mce));
1611 buf += sizeof(struct mce);
1612 memset(&mcelog.entry[i], 0, sizeof(struct mce));
1620 mutex_unlock(&mce_read_mutex);
1623 return err ? err : buf - ubuf;
1626 static unsigned int mce_poll(struct file *file, poll_table *wait)
1628 poll_wait(file, &mce_wait, wait);
1629 if (rcu_dereference_check_mce(mcelog.next))
1630 return POLLIN | POLLRDNORM;
1631 if (!mce_apei_read_done && apei_check_mce())
1632 return POLLIN | POLLRDNORM;
1636 static long mce_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
1638 int __user *p = (int __user *)arg;
1640 if (!capable(CAP_SYS_ADMIN))
1644 case MCE_GET_RECORD_LEN:
1645 return put_user(sizeof(struct mce), p);
1646 case MCE_GET_LOG_LEN:
1647 return put_user(MCE_LOG_LEN, p);
1648 case MCE_GETCLEAR_FLAGS: {
1652 flags = mcelog.flags;
1653 } while (cmpxchg(&mcelog.flags, flags, 0) != flags);
1655 return put_user(flags, p);
1662 /* Modified in mce-inject.c, so not static or const */
1663 struct file_operations mce_chrdev_ops = {
1665 .release = mce_release,
1668 .unlocked_ioctl = mce_ioctl,
1670 EXPORT_SYMBOL_GPL(mce_chrdev_ops);
1672 static struct miscdevice mce_log_device = {
1679 * mce=off Disables machine check
1680 * mce=no_cmci Disables CMCI
1681 * mce=dont_log_ce Clears corrected events silently, no log created for CEs.
1682 * mce=ignore_ce Disables polling and CMCI, corrected events are not cleared.
1683 * mce=TOLERANCELEVEL[,monarchtimeout] (number, see above)
1684 * monarchtimeout is how long to wait for other CPUs on machine
1685 * check, or 0 to not wait
1686 * mce=bootlog Log MCEs from before booting. Disabled by default on AMD.
1687 * mce=nobootlog Don't log MCEs from before booting.
1689 static int __init mcheck_enable(char *str)
1697 if (!strcmp(str, "off"))
1699 else if (!strcmp(str, "no_cmci"))
1700 mce_cmci_disabled = 1;
1701 else if (!strcmp(str, "dont_log_ce"))
1702 mce_dont_log_ce = 1;
1703 else if (!strcmp(str, "ignore_ce"))
1705 else if (!strcmp(str, "bootlog") || !strcmp(str, "nobootlog"))
1706 mce_bootlog = (str[0] == 'b');
1707 else if (isdigit(str[0])) {
1708 get_option(&str, &tolerant);
1711 get_option(&str, &monarch_timeout);
1714 printk(KERN_INFO "mce argument %s ignored. Please use /sys\n",
1720 __setup("mce", mcheck_enable);
1722 int __init mcheck_init(void)
1724 atomic_notifier_chain_register(&x86_mce_decoder_chain, &mce_dec_nb);
1726 mcheck_intel_therm_init();
1736 * Disable machine checks on suspend and shutdown. We can't really handle
1739 static int mce_disable_error_reporting(void)
1743 for (i = 0; i < banks; i++) {
1744 struct mce_bank *b = &mce_banks[i];
1747 wrmsrl(MSR_IA32_MCx_CTL(i), 0);
1752 static int mce_suspend(struct sys_device *dev, pm_message_t state)
1754 return mce_disable_error_reporting();
1757 static int mce_shutdown(struct sys_device *dev)
1759 return mce_disable_error_reporting();
1763 * On resume clear all MCE state. Don't want to see leftovers from the BIOS.
1764 * Only one CPU is active at this time, the others get re-added later using
1767 static int mce_resume(struct sys_device *dev)
1769 __mcheck_cpu_init_generic();
1770 __mcheck_cpu_init_vendor(¤t_cpu_data);
1775 static void mce_cpu_restart(void *data)
1777 del_timer_sync(&__get_cpu_var(mce_timer));
1778 if (!mce_available(¤t_cpu_data))
1780 __mcheck_cpu_init_generic();
1781 __mcheck_cpu_init_timer();
1784 /* Reinit MCEs after user configuration changes */
1785 static void mce_restart(void)
1787 on_each_cpu(mce_cpu_restart, NULL, 1);
1790 /* Toggle features for corrected errors */
1791 static void mce_disable_ce(void *all)
1793 if (!mce_available(¤t_cpu_data))
1796 del_timer_sync(&__get_cpu_var(mce_timer));
1800 static void mce_enable_ce(void *all)
1802 if (!mce_available(¤t_cpu_data))
1807 __mcheck_cpu_init_timer();
1810 static struct sysdev_class mce_sysclass = {
1811 .suspend = mce_suspend,
1812 .shutdown = mce_shutdown,
1813 .resume = mce_resume,
1814 .name = "machinecheck",
1817 DEFINE_PER_CPU(struct sys_device, mce_dev);
1820 void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu);
1822 static inline struct mce_bank *attr_to_bank(struct sysdev_attribute *attr)
1824 return container_of(attr, struct mce_bank, attr);
1827 static ssize_t show_bank(struct sys_device *s, struct sysdev_attribute *attr,
1830 return sprintf(buf, "%llx\n", attr_to_bank(attr)->ctl);
1833 static ssize_t set_bank(struct sys_device *s, struct sysdev_attribute *attr,
1834 const char *buf, size_t size)
1838 if (strict_strtoull(buf, 0, &new) < 0)
1841 attr_to_bank(attr)->ctl = new;
1848 show_trigger(struct sys_device *s, struct sysdev_attribute *attr, char *buf)
1850 strcpy(buf, mce_helper);
1852 return strlen(mce_helper) + 1;
1855 static ssize_t set_trigger(struct sys_device *s, struct sysdev_attribute *attr,
1856 const char *buf, size_t siz)
1860 strncpy(mce_helper, buf, sizeof(mce_helper));
1861 mce_helper[sizeof(mce_helper)-1] = 0;
1862 p = strchr(mce_helper, '\n');
1867 return strlen(mce_helper) + !!p;
1870 static ssize_t set_ignore_ce(struct sys_device *s,
1871 struct sysdev_attribute *attr,
1872 const char *buf, size_t size)
1876 if (strict_strtoull(buf, 0, &new) < 0)
1879 if (mce_ignore_ce ^ !!new) {
1881 /* disable ce features */
1882 on_each_cpu(mce_disable_ce, (void *)1, 1);
1885 /* enable ce features */
1887 on_each_cpu(mce_enable_ce, (void *)1, 1);
1893 static ssize_t set_cmci_disabled(struct sys_device *s,
1894 struct sysdev_attribute *attr,
1895 const char *buf, size_t size)
1899 if (strict_strtoull(buf, 0, &new) < 0)
1902 if (mce_cmci_disabled ^ !!new) {
1905 on_each_cpu(mce_disable_ce, NULL, 1);
1906 mce_cmci_disabled = 1;
1909 mce_cmci_disabled = 0;
1910 on_each_cpu(mce_enable_ce, NULL, 1);
1916 static ssize_t store_int_with_restart(struct sys_device *s,
1917 struct sysdev_attribute *attr,
1918 const char *buf, size_t size)
1920 ssize_t ret = sysdev_store_int(s, attr, buf, size);
1925 static SYSDEV_ATTR(trigger, 0644, show_trigger, set_trigger);
1926 static SYSDEV_INT_ATTR(tolerant, 0644, tolerant);
1927 static SYSDEV_INT_ATTR(monarch_timeout, 0644, monarch_timeout);
1928 static SYSDEV_INT_ATTR(dont_log_ce, 0644, mce_dont_log_ce);
1930 static struct sysdev_ext_attribute attr_check_interval = {
1931 _SYSDEV_ATTR(check_interval, 0644, sysdev_show_int,
1932 store_int_with_restart),
1936 static struct sysdev_ext_attribute attr_ignore_ce = {
1937 _SYSDEV_ATTR(ignore_ce, 0644, sysdev_show_int, set_ignore_ce),
1941 static struct sysdev_ext_attribute attr_cmci_disabled = {
1942 _SYSDEV_ATTR(cmci_disabled, 0644, sysdev_show_int, set_cmci_disabled),
1946 static struct sysdev_attribute *mce_attrs[] = {
1947 &attr_tolerant.attr,
1948 &attr_check_interval.attr,
1950 &attr_monarch_timeout.attr,
1951 &attr_dont_log_ce.attr,
1952 &attr_ignore_ce.attr,
1953 &attr_cmci_disabled.attr,
1957 static cpumask_var_t mce_dev_initialized;
1959 /* Per cpu sysdev init. All of the cpus still share the same ctrl bank: */
1960 static __cpuinit int mce_create_device(unsigned int cpu)
1965 if (!mce_available(&boot_cpu_data))
1968 memset(&per_cpu(mce_dev, cpu).kobj, 0, sizeof(struct kobject));
1969 per_cpu(mce_dev, cpu).id = cpu;
1970 per_cpu(mce_dev, cpu).cls = &mce_sysclass;
1972 err = sysdev_register(&per_cpu(mce_dev, cpu));
1976 for (i = 0; mce_attrs[i]; i++) {
1977 err = sysdev_create_file(&per_cpu(mce_dev, cpu), mce_attrs[i]);
1981 for (j = 0; j < banks; j++) {
1982 err = sysdev_create_file(&per_cpu(mce_dev, cpu),
1983 &mce_banks[j].attr);
1987 cpumask_set_cpu(cpu, mce_dev_initialized);
1992 sysdev_remove_file(&per_cpu(mce_dev, cpu), &mce_banks[j].attr);
1995 sysdev_remove_file(&per_cpu(mce_dev, cpu), mce_attrs[i]);
1997 sysdev_unregister(&per_cpu(mce_dev, cpu));
2002 static __cpuinit void mce_remove_device(unsigned int cpu)
2006 if (!cpumask_test_cpu(cpu, mce_dev_initialized))
2009 for (i = 0; mce_attrs[i]; i++)
2010 sysdev_remove_file(&per_cpu(mce_dev, cpu), mce_attrs[i]);
2012 for (i = 0; i < banks; i++)
2013 sysdev_remove_file(&per_cpu(mce_dev, cpu), &mce_banks[i].attr);
2015 sysdev_unregister(&per_cpu(mce_dev, cpu));
2016 cpumask_clear_cpu(cpu, mce_dev_initialized);
2019 /* Make sure there are no machine checks on offlined CPUs. */
2020 static void __cpuinit mce_disable_cpu(void *h)
2022 unsigned long action = *(unsigned long *)h;
2025 if (!mce_available(¤t_cpu_data))
2028 if (!(action & CPU_TASKS_FROZEN))
2030 for (i = 0; i < banks; i++) {
2031 struct mce_bank *b = &mce_banks[i];
2034 wrmsrl(MSR_IA32_MCx_CTL(i), 0);
2038 static void __cpuinit mce_reenable_cpu(void *h)
2040 unsigned long action = *(unsigned long *)h;
2043 if (!mce_available(¤t_cpu_data))
2046 if (!(action & CPU_TASKS_FROZEN))
2048 for (i = 0; i < banks; i++) {
2049 struct mce_bank *b = &mce_banks[i];
2052 wrmsrl(MSR_IA32_MCx_CTL(i), b->ctl);
2056 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
2057 static int __cpuinit
2058 mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
2060 unsigned int cpu = (unsigned long)hcpu;
2061 struct timer_list *t = &per_cpu(mce_timer, cpu);
2065 case CPU_ONLINE_FROZEN:
2066 mce_create_device(cpu);
2067 if (threshold_cpu_callback)
2068 threshold_cpu_callback(action, cpu);
2071 case CPU_DEAD_FROZEN:
2072 if (threshold_cpu_callback)
2073 threshold_cpu_callback(action, cpu);
2074 mce_remove_device(cpu);
2076 case CPU_DOWN_PREPARE:
2077 case CPU_DOWN_PREPARE_FROZEN:
2079 smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
2081 case CPU_DOWN_FAILED:
2082 case CPU_DOWN_FAILED_FROZEN:
2083 if (!mce_ignore_ce && check_interval) {
2084 t->expires = round_jiffies(jiffies +
2085 __get_cpu_var(mce_next_interval));
2086 add_timer_on(t, cpu);
2088 smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
2091 /* intentionally ignoring frozen here */
2092 cmci_rediscover(cpu);
2098 static struct notifier_block mce_cpu_notifier __cpuinitdata = {
2099 .notifier_call = mce_cpu_callback,
2102 static __init void mce_init_banks(void)
2106 for (i = 0; i < banks; i++) {
2107 struct mce_bank *b = &mce_banks[i];
2108 struct sysdev_attribute *a = &b->attr;
2110 sysfs_attr_init(&a->attr);
2111 a->attr.name = b->attrname;
2112 snprintf(b->attrname, ATTR_LEN, "bank%d", i);
2114 a->attr.mode = 0644;
2115 a->show = show_bank;
2116 a->store = set_bank;
2120 static __init int mcheck_init_device(void)
2125 if (!mce_available(&boot_cpu_data))
2128 zalloc_cpumask_var(&mce_dev_initialized, GFP_KERNEL);
2132 err = sysdev_class_register(&mce_sysclass);
2136 for_each_online_cpu(i) {
2137 err = mce_create_device(i);
2142 register_hotcpu_notifier(&mce_cpu_notifier);
2143 misc_register(&mce_log_device);
2148 device_initcall(mcheck_init_device);
2151 * Old style boot options parsing. Only for compatibility.
2153 static int __init mcheck_disable(char *str)
2158 __setup("nomce", mcheck_disable);
2160 #ifdef CONFIG_DEBUG_FS
2161 struct dentry *mce_get_debugfs_dir(void)
2163 static struct dentry *dmce;
2166 dmce = debugfs_create_dir("mce", NULL);
2171 static void mce_reset(void)
2174 atomic_set(&mce_fake_paniced, 0);
2175 atomic_set(&mce_executing, 0);
2176 atomic_set(&mce_callin, 0);
2177 atomic_set(&global_nwo, 0);
2180 static int fake_panic_get(void *data, u64 *val)
2186 static int fake_panic_set(void *data, u64 val)
2193 DEFINE_SIMPLE_ATTRIBUTE(fake_panic_fops, fake_panic_get,
2194 fake_panic_set, "%llu\n");
2196 static int __init mcheck_debugfs_init(void)
2198 struct dentry *dmce, *ffake_panic;
2200 dmce = mce_get_debugfs_dir();
2203 ffake_panic = debugfs_create_file("fake_panic", 0444, dmce, NULL,
2210 late_initcall(mcheck_debugfs_init);