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Diffstat (limited to 'arch/i386/kernel/nmi.c')
-rw-r--r--arch/i386/kernel/nmi.c85
1 files changed, 11 insertions, 74 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index bd96ea4f2942..acd3fdea2a21 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -42,20 +42,6 @@ static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[3]);
42 */ 42 */
43#define NMI_MAX_COUNTER_BITS 66 43#define NMI_MAX_COUNTER_BITS 66
44 44
45/*
46 * lapic_nmi_owner tracks the ownership of the lapic NMI hardware:
47 * - it may be reserved by some other driver, or not
48 * - when not reserved by some other driver, it may be used for
49 * the NMI watchdog, or not
50 *
51 * This is maintained separately from nmi_active because the NMI
52 * watchdog may also be driven from the I/O APIC timer.
53 */
54static DEFINE_SPINLOCK(lapic_nmi_owner_lock);
55static unsigned int lapic_nmi_owner;
56#define LAPIC_NMI_WATCHDOG (1<<0)
57#define LAPIC_NMI_RESERVED (1<<1)
58
59/* nmi_active: 45/* nmi_active:
60 * >0: the lapic NMI watchdog is active, but can be disabled 46 * >0: the lapic NMI watchdog is active, but can be disabled
61 * <0: the lapic NMI watchdog has not been set up, and cannot 47 * <0: the lapic NMI watchdog has not been set up, and cannot
@@ -325,33 +311,6 @@ static void enable_lapic_nmi_watchdog(void)
325 touch_nmi_watchdog(); 311 touch_nmi_watchdog();
326} 312}
327 313
328int reserve_lapic_nmi(void)
329{
330 unsigned int old_owner;
331
332 spin_lock(&lapic_nmi_owner_lock);
333 old_owner = lapic_nmi_owner;
334 lapic_nmi_owner |= LAPIC_NMI_RESERVED;
335 spin_unlock(&lapic_nmi_owner_lock);
336 if (old_owner & LAPIC_NMI_RESERVED)
337 return -EBUSY;
338 if (old_owner & LAPIC_NMI_WATCHDOG)
339 disable_lapic_nmi_watchdog();
340 return 0;
341}
342
343void release_lapic_nmi(void)
344{
345 unsigned int new_owner;
346
347 spin_lock(&lapic_nmi_owner_lock);
348 new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED;
349 lapic_nmi_owner = new_owner;
350 spin_unlock(&lapic_nmi_owner_lock);
351 if (new_owner & LAPIC_NMI_WATCHDOG)
352 enable_lapic_nmi_watchdog();
353}
354
355void disable_timer_nmi_watchdog(void) 314void disable_timer_nmi_watchdog(void)
356{ 315{
357 BUG_ON(nmi_watchdog != NMI_IO_APIC); 316 BUG_ON(nmi_watchdog != NMI_IO_APIC);
@@ -866,6 +825,15 @@ done:
866 return rc; 825 return rc;
867} 826}
868 827
828int do_nmi_callback(struct pt_regs * regs, int cpu)
829{
830#ifdef CONFIG_SYSCTL
831 if (unknown_nmi_panic)
832 return unknown_nmi_panic_callback(regs, cpu);
833#endif
834 return 0;
835}
836
869#ifdef CONFIG_SYSCTL 837#ifdef CONFIG_SYSCTL
870 838
871static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) 839static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
@@ -873,37 +841,8 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
873 unsigned char reason = get_nmi_reason(); 841 unsigned char reason = get_nmi_reason();
874 char buf[64]; 842 char buf[64];
875 843
876 if (!(reason & 0xc0)) { 844 sprintf(buf, "NMI received for unknown reason %02x\n", reason);
877 sprintf(buf, "NMI received for unknown reason %02x\n", reason); 845 die_nmi(regs, buf);
878 die_nmi(regs, buf);
879 }
880 return 0;
881}
882
883/*
884 * proc handler for /proc/sys/kernel/unknown_nmi_panic
885 */
886int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file,
887 void __user *buffer, size_t *length, loff_t *ppos)
888{
889 int old_state;
890
891 old_state = unknown_nmi_panic;
892 proc_dointvec(table, write, file, buffer, length, ppos);
893 if (!!old_state == !!unknown_nmi_panic)
894 return 0;
895
896 if (unknown_nmi_panic) {
897 if (reserve_lapic_nmi() < 0) {
898 unknown_nmi_panic = 0;
899 return -EBUSY;
900 } else {
901 set_nmi_callback(unknown_nmi_panic_callback);
902 }
903 } else {
904 release_lapic_nmi();
905 unset_nmi_callback();
906 }
907 return 0; 846 return 0;
908} 847}
909 848
@@ -917,7 +856,5 @@ EXPORT_SYMBOL(reserve_perfctr_nmi);
917EXPORT_SYMBOL(release_perfctr_nmi); 856EXPORT_SYMBOL(release_perfctr_nmi);
918EXPORT_SYMBOL(reserve_evntsel_nmi); 857EXPORT_SYMBOL(reserve_evntsel_nmi);
919EXPORT_SYMBOL(release_evntsel_nmi); 858EXPORT_SYMBOL(release_evntsel_nmi);
920EXPORT_SYMBOL(reserve_lapic_nmi);
921EXPORT_SYMBOL(release_lapic_nmi);
922EXPORT_SYMBOL(disable_timer_nmi_watchdog); 859EXPORT_SYMBOL(disable_timer_nmi_watchdog);
923EXPORT_SYMBOL(enable_timer_nmi_watchdog); 860EXPORT_SYMBOL(enable_timer_nmi_watchdog);