diff options
Diffstat (limited to 'arch/x86/kernel/smp.c')
| -rw-r--r-- | arch/x86/kernel/smp.c | 72 |
1 files changed, 70 insertions, 2 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 16204dc1548..66c74f481ca 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -29,6 +29,7 @@ #include <asm/mmu_context.h> #include <asm/proto.h> #include <asm/apic.h> +#include <asm/nmi.h> /* * Some notes on x86 processor bugs affecting SMP operation: * @@ -148,6 +149,60 @@ void native_send_call_func_ipi(const struct cpumask *mask) free_cpumask_var(allbutself); } +static atomic_t stopping_cpu = ATOMIC_INIT(-1); + +static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs) +{ + /* We are registered on stopping cpu too, avoid spurious NMI */ + if (raw_smp_processor_id() == atomic_read(&stopping_cpu)) + return NMI_HANDLED; + + stop_this_cpu(NULL); + + return NMI_HANDLED; +} + +static void native_nmi_stop_other_cpus(int wait) +{ + unsigned long flags; + unsigned long timeout; + + if (reboot_force) + return; + + /* + * Use an own vector here because smp_call_function + * does lots of things not suitable in a panic situation. + */ + if (num_online_cpus() > 1) { + /* did someone beat us here? */ + if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1) + return; + + if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback, + NMI_FLAG_FIRST, "smp_stop")) + /* Note: we ignore failures here */ + return; + + /* sync above data before sending NMI */ + wmb(); + + apic->send_IPI_allbutself(NMI_VECTOR); + + /* + * Don't wait longer than a second if the caller + * didn't ask us to wait. + */ + timeout = USEC_PER_SEC; + while (num_online_cpus() > 1 && (wait || timeout--)) + udelay(1); + } + + local_irq_save(flags); + disable_local_APIC(); + local_irq_restore(flags); +} + /* * this function calls the 'stop' function on all other CPUs in the system. */ @@ -160,7 +215,7 @@ asmlinkage void smp_reboot_interrupt(void) irq_exit(); } -static void native_stop_other_cpus(int wait) +static void native_irq_stop_other_cpus(int wait) { unsigned long flags; unsigned long timeout; @@ -194,6 +249,11 @@ static void native_stop_other_cpus(int wait) local_irq_restore(flags); } +static void native_smp_disable_nmi_ipi(void) +{ + smp_ops.stop_other_cpus = native_irq_stop_other_cpus; +} + /* * Reschedule call back. */ @@ -225,12 +285,20 @@ void smp_call_function_single_interrupt(struct pt_regs *regs) irq_exit(); } +static int __init nonmi_ipi_setup(char *str) +{ + native_smp_disable_nmi_ipi(); + return 1; +} + +__setup("nonmi_ipi", nonmi_ipi_setup); + struct smp_ops smp_ops = { .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu, .smp_prepare_cpus = native_smp_prepare_cpus, .smp_cpus_done = native_smp_cpus_done, - .stop_other_cpus = native_stop_other_cpus, + .stop_other_cpus = native_nmi_stop_other_cpus, .smp_send_reschedule = native_smp_send_reschedule, .cpu_up = native_cpu_up, |