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author | Ingo Molnar <mingo@elte.hu> | 2008-12-17 12:24:52 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-12-17 12:24:52 (GMT) |
commit | 855caa37b9b61c1ccfeb91a2bc04d90bfc5e4525 (patch) | |
tree | f95e80165c293f43321b17c4280acfca478d9ba8 /arch/x86/kernel/reboot.c | |
parent | 948a7b2b5e2bf126fb697aeb11ff379b2c85dd2e (diff) | |
parent | c415b3dce30dfb41234e118662e8720f47343a4f (diff) | |
download | linux-fsl-qoriq-855caa37b9b61c1ccfeb91a2bc04d90bfc5e4525.tar.xz |
Merge branch 'x86/crashdump' into cpus4096
Conflicts:
arch/x86/kernel/crash.c
Merged for semantic conflict:
arch/x86/kernel/reboot.c
Diffstat (limited to 'arch/x86/kernel/reboot.c')
-rw-r--r-- | arch/x86/kernel/reboot.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 0e3dbc7..ba7b9a0 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -21,6 +21,9 @@ # include <asm/iommu.h> #endif +#include <mach_ipi.h> + + /* * Power off function, if any */ @@ -548,3 +551,92 @@ void machine_crash_shutdown(struct pt_regs *regs) machine_ops.crash_shutdown(regs); } #endif + + +#if defined(CONFIG_SMP) + +/* This keeps a track of which one is crashing cpu. */ +static int crashing_cpu; +static nmi_shootdown_cb shootdown_callback; + +static atomic_t waiting_for_crash_ipi; + +static int crash_nmi_callback(struct notifier_block *self, + unsigned long val, void *data) +{ + int cpu; + + if (val != DIE_NMI_IPI) + return NOTIFY_OK; + + cpu = raw_smp_processor_id(); + + /* 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 NOTIFY_STOP; + local_irq_disable(); + + shootdown_callback(cpu, (struct die_args *)data); + + atomic_dec(&waiting_for_crash_ipi); + /* Assume hlt works */ + halt(); + for (;;) + cpu_relax(); + + return 1; +} + +static void smp_send_nmi_allbutself(void) +{ + send_IPI_allbutself(NMI_VECTOR); +} + +static struct notifier_block crash_nmi_nb = { + .notifier_call = crash_nmi_callback, +}; + +/* Halt all other CPUs, calling the specified function on each of them + * + * This function can be used to halt all other CPUs on crash + * or emergency reboot time. The function passed as parameter + * will be called inside a NMI handler on all CPUs. + */ +void nmi_shootdown_cpus(nmi_shootdown_cb callback) +{ + unsigned long msecs; + local_irq_disable(); + + /* Make a note of crashing cpu. Will be used in NMI callback.*/ + crashing_cpu = safe_smp_processor_id(); + + shootdown_callback = callback; + + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + /* Would it be better to replace the trap vector here? */ + if (register_die_notifier(&crash_nmi_nb)) + return; /* return what? */ + /* 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 */ +} +#else /* !CONFIG_SMP */ +void nmi_shootdown_cpus(nmi_shootdown_cb callback) +{ + /* No other CPUs to shoot down */ +} +#endif |