diff options
| -rw-r--r-- | arch/i386/kernel/smp.c | 68 | ||||
| -rw-r--r-- | arch/x86_64/kernel/smp.c | 28 | ||||
| -rw-r--r-- | include/asm-x86_64/smp.h | 1 |
3 files changed, 48 insertions, 49 deletions
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c index 0e8977871b1..0cd459baad6 100644 --- a/arch/i386/kernel/smp.c +++ b/arch/i386/kernel/smp.c @@ -515,35 +515,14 @@ void unlock_ipi_call_lock(void) static struct call_data_struct *call_data; -/** - * smp_call_function(): Run a function on all other CPUs. - * @func: The function to run. This must be fast and non-blocking. - * @info: An arbitrary pointer to pass to the function. - * @nonatomic: currently unused. - * @wait: If true, wait (atomically) until function has completed on other CPUs. - * - * Returns 0 on success, else a negative status code. Does not return until - * remote CPUs are nearly ready to execute <<func>> or are or have executed. - * - * You must not call this function with disabled interrupts or from a - * hardware interrupt handler or from a bottom half handler. - */ -int smp_call_function (void (*func) (void *info), void *info, int nonatomic, - int wait) +static void __smp_call_function(void (*func) (void *info), void *info, + int nonatomic, int wait) { struct call_data_struct data; - int cpus; - - /* Holding any lock stops cpus from going down. */ - spin_lock(&call_lock); - cpus = num_online_cpus() - 1; - if (!cpus) { - spin_unlock(&call_lock); - return 0; - } + int cpus = num_online_cpus() - 1; - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); + if (!cpus) + return; data.func = func; data.info = info; @@ -565,6 +544,30 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, if (wait) while (atomic_read(&data.finished) != cpus) cpu_relax(); +} + +/** + * smp_call_function(): Run a function on all other CPUs. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @nonatomic: currently unused. + * @wait: If true, wait (atomically) until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. Does not return until + * remote CPUs are nearly ready to execute <<func>> or are or have executed. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. + */ +int smp_call_function (void (*func) (void *info), void *info, int nonatomic, + int wait) +{ + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + + /* Holding any lock stops cpus from going down. */ + spin_lock(&call_lock); + __smp_call_function(func, info, nonatomic, wait); spin_unlock(&call_lock); return 0; @@ -573,11 +576,11 @@ EXPORT_SYMBOL(smp_call_function); static void stop_this_cpu (void * dummy) { + local_irq_disable(); /* * Remove this CPU: */ cpu_clear(smp_processor_id(), cpu_online_map); - local_irq_disable(); disable_local_APIC(); if (cpu_data[smp_processor_id()].hlt_works_ok) for(;;) halt(); @@ -590,11 +593,16 @@ static void stop_this_cpu (void * dummy) void smp_send_stop(void) { - smp_call_function(stop_this_cpu, NULL, 1, 0); + /* Don't deadlock on the call lock in panic */ + int nolock = !spin_trylock(&call_lock); + unsigned long flags; - local_irq_disable(); + local_irq_save(flags); + __smp_call_function(stop_this_cpu, NULL, 0, 0); + if (!nolock) + spin_unlock(&call_lock); disable_local_APIC(); - local_irq_enable(); + local_irq_restore(flags); } /* diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c index af1ec4d23cf..bd1d123947c 100644 --- a/arch/x86_64/kernel/smp.c +++ b/arch/x86_64/kernel/smp.c @@ -452,42 +452,34 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, } EXPORT_SYMBOL(smp_call_function); -void smp_stop_cpu(void) +static void stop_this_cpu(void *dummy) { - unsigned long flags; + local_irq_disable(); /* * Remove this CPU: */ cpu_clear(smp_processor_id(), cpu_online_map); - local_irq_save(flags); disable_local_APIC(); - local_irq_restore(flags); -} - -static void smp_really_stop_cpu(void *dummy) -{ - smp_stop_cpu(); for (;;) halt(); } void smp_send_stop(void) { - int nolock = 0; + int nolock; + unsigned long flags; + if (reboot_force) return; + /* Don't deadlock on the call lock in panic */ - if (!spin_trylock(&call_lock)) { - /* ignore locking because we have panicked anyways */ - nolock = 1; - } - __smp_call_function(smp_really_stop_cpu, NULL, 0, 0); + nolock = !spin_trylock(&call_lock); + local_irq_save(flags); + __smp_call_function(stop_this_cpu, NULL, 0, 0); if (!nolock) spin_unlock(&call_lock); - - local_irq_disable(); disable_local_APIC(); - local_irq_enable(); + local_irq_restore(flags); } /* diff --git a/include/asm-x86_64/smp.h b/include/asm-x86_64/smp.h index f4236d7789a..d5704421456 100644 --- a/include/asm-x86_64/smp.h +++ b/include/asm-x86_64/smp.h @@ -37,7 +37,6 @@ extern void lock_ipi_call_lock(void); extern void unlock_ipi_call_lock(void); extern int smp_num_siblings; extern void smp_send_reschedule(int cpu); -void smp_stop_cpu(void); extern cpumask_t cpu_sibling_map[NR_CPUS]; extern cpumask_t cpu_core_map[NR_CPUS]; |