diff options
author | akpm@osdl.org <akpm@osdl.org> | 2006-01-09 23:51:48 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-10 11:01:27 -0500 |
commit | cffe632a25b017dac4b6f060cad31940c6c167b4 (patch) | |
tree | 569cc877cdd035a469bec2a1b75b555313a257ca /arch/x86_64 | |
parent | aac04b32f3e4c63f461459d0e1d6aa01caac6e66 (diff) |
[PATCH] kdump: x86_64 kexec on panic
)
From: Vivek Goyal <vgoyal@in.ibm.com>
- Implementing the machine_crash_shutdown for x86_64 which will be called by
crash_kexec (called in case of a panic, sysrq etc.). Here we do things
similar to i386. Disable the interrupts, shootdown the cpus and shutdown
LAPIC and IOAPIC.
Changes in this version:
- As the Eric's APIC initialization patches are reverted back, reintroducing
LAPIC and IOAPIC shutdown.
- Added some comments on CPU hotplug, modified code as suggested by Andi
kleen.
Signed-off-by: Murali M Chakravarthy <muralim@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64')
-rw-r--r-- | arch/x86_64/kernel/crash.c | 86 |
1 files changed, 85 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/crash.c b/arch/x86_64/kernel/crash.c index efe450760bb..abc601f36b6 100644 --- a/arch/x86_64/kernel/crash.c +++ b/arch/x86_64/kernel/crash.c | |||
@@ -13,15 +13,85 @@ | |||
13 | #include <linux/smp.h> | 13 | #include <linux/smp.h> |
14 | #include <linux/reboot.h> | 14 | #include <linux/reboot.h> |
15 | #include <linux/kexec.h> | 15 | #include <linux/kexec.h> |
16 | #include <linux/delay.h> | ||
16 | 17 | ||
17 | #include <asm/processor.h> | 18 | #include <asm/processor.h> |
18 | #include <asm/hardirq.h> | 19 | #include <asm/hardirq.h> |
19 | #include <asm/nmi.h> | 20 | #include <asm/nmi.h> |
20 | #include <asm/hw_irq.h> | 21 | #include <asm/hw_irq.h> |
22 | #include <asm/mach_apic.h> | ||
23 | |||
24 | /* This keeps a track of which one is crashing cpu. */ | ||
25 | static int crashing_cpu; | ||
26 | |||
27 | #ifdef CONFIG_SMP | ||
28 | static atomic_t waiting_for_crash_ipi; | ||
29 | |||
30 | static int crash_nmi_callback(struct pt_regs *regs, int cpu) | ||
31 | { | ||
32 | /* | ||
33 | * Don't do anything if this handler is invoked on crashing cpu. | ||
34 | * Otherwise, system will completely hang. Crashing cpu can get | ||
35 | * an NMI if system was initially booted with nmi_watchdog parameter. | ||
36 | */ | ||
37 | if (cpu == crashing_cpu) | ||
38 | return 1; | ||
39 | local_irq_disable(); | ||
40 | |||
41 | disable_local_APIC(); | ||
42 | atomic_dec(&waiting_for_crash_ipi); | ||
43 | /* Assume hlt works */ | ||
44 | for(;;) | ||
45 | asm("hlt"); | ||
46 | |||
47 | return 1; | ||
48 | } | ||
49 | |||
50 | static void smp_send_nmi_allbutself(void) | ||
51 | { | ||
52 | send_IPI_allbutself(APIC_DM_NMI); | ||
53 | } | ||
54 | |||
55 | /* | ||
56 | * This code is a best effort heuristic to get the | ||
57 | * other cpus to stop executing. So races with | ||
58 | * cpu hotplug shouldn't matter. | ||
59 | */ | ||
60 | |||
61 | static void nmi_shootdown_cpus(void) | ||
62 | { | ||
63 | unsigned long msecs; | ||
64 | |||
65 | atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); | ||
66 | set_nmi_callback(crash_nmi_callback); | ||
67 | |||
68 | /* | ||
69 | * Ensure the new callback function is set before sending | ||
70 | * out the NMI | ||
71 | */ | ||
72 | wmb(); | ||
73 | |||
74 | smp_send_nmi_allbutself(); | ||
75 | |||
76 | msecs = 1000; /* Wait at most a second for the other cpus to stop */ | ||
77 | while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { | ||
78 | mdelay(1); | ||
79 | msecs--; | ||
80 | } | ||
81 | /* Leave the nmi callback set */ | ||
82 | disable_local_APIC(); | ||
83 | } | ||
84 | #else | ||
85 | static void nmi_shootdown_cpus(void) | ||
86 | { | ||
87 | /* There are no cpus to shootdown */ | ||
88 | } | ||
89 | #endif | ||
21 | 90 | ||
22 | void machine_crash_shutdown(struct pt_regs *regs) | 91 | void machine_crash_shutdown(struct pt_regs *regs) |
23 | { | 92 | { |
24 | /* This function is only called after the system | 93 | /* |
94 | * This function is only called after the system | ||
25 | * has paniced or is otherwise in a critical state. | 95 | * has paniced or is otherwise in a critical state. |
26 | * The minimum amount of code to allow a kexec'd kernel | 96 | * The minimum amount of code to allow a kexec'd kernel |
27 | * to run successfully needs to happen here. | 97 | * to run successfully needs to happen here. |
@@ -29,4 +99,18 @@ void machine_crash_shutdown(struct pt_regs *regs) | |||
29 | * In practice this means shooting down the other cpus in | 99 | * In practice this means shooting down the other cpus in |
30 | * an SMP system. | 100 | * an SMP system. |
31 | */ | 101 | */ |
102 | /* The kernel is broken so disable interrupts */ | ||
103 | local_irq_disable(); | ||
104 | |||
105 | /* Make a note of crashing cpu. Will be used in NMI callback.*/ | ||
106 | crashing_cpu = smp_processor_id(); | ||
107 | nmi_shootdown_cpus(); | ||
108 | |||
109 | if(cpu_has_apic) | ||
110 | disable_local_APIC(); | ||
111 | |||
112 | #if defined(CONFIG_X86_IO_APIC) | ||
113 | disable_IO_APIC(); | ||
114 | #endif | ||
115 | |||
32 | } | 116 | } |