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-rw-r--r--arch/i386/kernel/crash.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c
index fa27a6c2abb6..882779c07874 100644
--- a/arch/i386/kernel/crash.c
+++ b/arch/i386/kernel/crash.c
@@ -23,12 +23,65 @@
23#include <asm/hardirq.h> 23#include <asm/hardirq.h>
24#include <asm/nmi.h> 24#include <asm/nmi.h>
25#include <asm/hw_irq.h> 25#include <asm/hw_irq.h>
26#include <mach_ipi.h>
26 27
27#define MAX_NOTE_BYTES 1024 28#define MAX_NOTE_BYTES 1024
28typedef u32 note_buf_t[MAX_NOTE_BYTES/4]; 29typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
29 30
30note_buf_t crash_notes[NR_CPUS]; 31note_buf_t crash_notes[NR_CPUS];
31 32
33#ifdef CONFIG_SMP
34static atomic_t waiting_for_crash_ipi;
35
36static int crash_nmi_callback(struct pt_regs *regs, int cpu)
37{
38 local_irq_disable();
39 atomic_dec(&waiting_for_crash_ipi);
40 /* Assume hlt works */
41 __asm__("hlt");
42 for(;;);
43 return 1;
44}
45
46/*
47 * By using the NMI code instead of a vector we just sneak thru the
48 * word generator coming out with just what we want. AND it does
49 * not matter if clustered_apic_mode is set or not.
50 */
51static void smp_send_nmi_allbutself(void)
52{
53 send_IPI_allbutself(APIC_DM_NMI);
54}
55
56static void nmi_shootdown_cpus(void)
57{
58 unsigned long msecs;
59 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
60
61 /* Would it be better to replace the trap vector here? */
62 set_nmi_callback(crash_nmi_callback);
63 /* Ensure the new callback function is set before sending
64 * out the NMI
65 */
66 wmb();
67
68 smp_send_nmi_allbutself();
69
70 msecs = 1000; /* Wait at most a second for the other cpus to stop */
71 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
72 mdelay(1);
73 msecs--;
74 }
75
76 /* Leave the nmi callback set */
77}
78#else
79static void nmi_shootdown_cpus(void)
80{
81 /* There are no cpus to shootdown */
82}
83#endif
84
32void machine_crash_shutdown(void) 85void machine_crash_shutdown(void)
33{ 86{
34 /* This function is only called after the system 87 /* This function is only called after the system
@@ -39,4 +92,7 @@ void machine_crash_shutdown(void)
39 * In practice this means shooting down the other cpus in 92 * In practice this means shooting down the other cpus in
40 * an SMP system. 93 * an SMP system.
41 */ 94 */
95 /* The kernel is broken so disable interrupts */
96 local_irq_disable();
97 nmi_shootdown_cpus();
42} 98}