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author | akpm@osdl.org <akpm@osdl.org> | 2006-01-09 20:51:48 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-10 08:01:27 -0800 |
commit | cffe632a25b017dac4b6f060cad31940c6c167b4 (patch) | |
tree | 569cc877cdd035a469bec2a1b75b555313a257ca /arch/x86_64/kernel/crash.c | |
parent | aac04b32f3e4c63f461459d0e1d6aa01caac6e66 (diff) | |
download | kernel_samsung_espresso10-cffe632a25b017dac4b6f060cad31940c6c167b4.zip kernel_samsung_espresso10-cffe632a25b017dac4b6f060cad31940c6c167b4.tar.gz kernel_samsung_espresso10-cffe632a25b017dac4b6f060cad31940c6c167b4.tar.bz2 |
[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/kernel/crash.c')
-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 efe4507..abc601f 100644 --- a/arch/x86_64/kernel/crash.c +++ b/arch/x86_64/kernel/crash.c @@ -13,15 +13,85 @@ #include <linux/smp.h> #include <linux/reboot.h> #include <linux/kexec.h> +#include <linux/delay.h> #include <asm/processor.h> #include <asm/hardirq.h> #include <asm/nmi.h> #include <asm/hw_irq.h> +#include <asm/mach_apic.h> + +/* This keeps a track of which one is crashing cpu. */ +static int crashing_cpu; + +#ifdef CONFIG_SMP +static atomic_t waiting_for_crash_ipi; + +static int crash_nmi_callback(struct pt_regs *regs, int cpu) +{ + /* + * Don't do anything if this handler is invoked on crashing cpu. + * Otherwise, system will completely hang. Crashing cpu can get + * an NMI if system was initially booted with nmi_watchdog parameter. + */ + if (cpu == crashing_cpu) + return 1; + local_irq_disable(); + + disable_local_APIC(); + atomic_dec(&waiting_for_crash_ipi); + /* Assume hlt works */ + for(;;) + asm("hlt"); + + return 1; +} + +static void smp_send_nmi_allbutself(void) +{ + send_IPI_allbutself(APIC_DM_NMI); +} + +/* + * This code is a best effort heuristic to get the + * other cpus to stop executing. So races with + * cpu hotplug shouldn't matter. + */ + +static void nmi_shootdown_cpus(void) +{ + unsigned long msecs; + + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + set_nmi_callback(crash_nmi_callback); + + /* + * Ensure the new callback function is set before sending + * out the NMI + */ + wmb(); + + smp_send_nmi_allbutself(); + + msecs = 1000; /* Wait at most a second for the other cpus to stop */ + while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { + mdelay(1); + msecs--; + } + /* Leave the nmi callback set */ + disable_local_APIC(); +} +#else +static void nmi_shootdown_cpus(void) +{ + /* There are no cpus to shootdown */ +} +#endif void machine_crash_shutdown(struct pt_regs *regs) { - /* This function is only called after the system + /* + * This function is only called after the system * has paniced or is otherwise in a critical state. * The minimum amount of code to allow a kexec'd kernel * to run successfully needs to happen here. @@ -29,4 +99,18 @@ void machine_crash_shutdown(struct pt_regs *regs) * In practice this means shooting down the other cpus in * an SMP system. */ + /* The kernel is broken so disable interrupts */ + local_irq_disable(); + + /* Make a note of crashing cpu. Will be used in NMI callback.*/ + crashing_cpu = smp_processor_id(); + nmi_shootdown_cpus(); + + if(cpu_has_apic) + disable_local_APIC(); + +#if defined(CONFIG_X86_IO_APIC) + disable_IO_APIC(); +#endif + } |