diff options
Diffstat (limited to 'arch/arm/kernel/smp.c')
-rw-r--r-- | arch/arm/kernel/smp.c | 111 |
1 files changed, 56 insertions, 55 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 84f4cbf..5919eb4 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -125,18 +125,6 @@ void __init smp_init_cpus(void) smp_ops.smp_init_cpus(); } -static void __init platform_smp_prepare_cpus(unsigned int max_cpus) -{ - if (smp_ops.smp_prepare_cpus) - smp_ops.smp_prepare_cpus(max_cpus); -} - -static void __cpuinit platform_secondary_init(unsigned int cpu) -{ - if (smp_ops.smp_secondary_init) - smp_ops.smp_secondary_init(cpu); -} - int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) { if (smp_ops.smp_boot_secondary) @@ -154,12 +142,6 @@ static int platform_cpu_kill(unsigned int cpu) return 1; } -static void platform_cpu_die(unsigned int cpu) -{ - if (smp_ops.cpu_die) - smp_ops.cpu_die(cpu); -} - static int platform_cpu_disable(unsigned int cpu) { if (smp_ops.cpu_disable) @@ -229,6 +211,13 @@ void __cpuinit __cpu_die(unsigned int cpu) } printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); + /* + * platform_cpu_kill() is generally expected to do the powering off + * and/or cutting of clocks to the dying CPU. Optionally, this may + * be done by the CPU which is dying in preference to supporting + * this call, but that means there is _no_ synchronisation between + * the requesting CPU and the dying CPU actually losing power. + */ if (!platform_cpu_kill(cpu)) printk("CPU%u: unable to kill\n", cpu); } @@ -248,16 +237,44 @@ void __ref cpu_die(void) idle_task_exit(); local_irq_disable(); - mb(); - /* Tell __cpu_die() that this CPU is now safe to dispose of */ - RCU_NONIDLE(complete(&cpu_died)); + /* + * Flush the data out of the L1 cache for this CPU. This must be + * before the completion to ensure that data is safely written out + * before platform_cpu_kill() gets called - which may disable + * *this* CPU and power down its cache. + */ + flush_cache_louis(); /* - * actual CPU shutdown procedure is at least platform (if not - * CPU) specific. + * Tell __cpu_die() that this CPU is now safe to dispose of. Once + * this returns, power and/or clocks can be removed at any point + * from this CPU and its cache by platform_cpu_kill(). */ - platform_cpu_die(cpu); + complete(&cpu_died); + + /* + * Ensure that the cache lines associated with that completion are + * written out. This covers the case where _this_ CPU is doing the + * powering down, to ensure that the completion is visible to the + * CPU waiting for this one. + */ + flush_cache_louis(); + + /* + * The actual CPU shutdown procedure is at least platform (if not + * CPU) specific. This may remove power, or it may simply spin. + * + * Platforms are generally expected *NOT* to return from this call, + * although there are some which do because they have no way to + * power down the CPU. These platforms are the _only_ reason we + * have a return path which uses the fragment of assembly below. + * + * The return path should not be used for platforms which can + * power off the CPU. + */ + if (smp_ops.cpu_die) + smp_ops.cpu_die(cpu); /* * Do not return to the idle loop - jump back to the secondary @@ -302,6 +319,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) * switch away from it before attempting any exclusive accesses. */ cpu_switch_mm(mm->pgd, mm); + local_flush_bp_all(); enter_lazy_tlb(mm, current); local_flush_tlb_all(); @@ -324,7 +342,8 @@ asmlinkage void __cpuinit secondary_start_kernel(void) /* * Give the platform a chance to do its own initialisation. */ - platform_secondary_init(cpu); + if (smp_ops.smp_secondary_init) + smp_ops.smp_secondary_init(cpu); notify_cpu_starting(cpu); @@ -351,7 +370,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) /* * OK, it's off to the idle thread for us */ - cpu_idle(); + cpu_startup_entry(CPUHP_ONLINE); } void __init smp_cpus_done(unsigned int max_cpus) @@ -399,8 +418,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus) /* * Initialise the present map, which describes the set of CPUs * actually populated at the present time. A platform should - * re-initialize the map in platform_smp_prepare_cpus() if - * present != possible (e.g. physical hotplug). + * re-initialize the map in the platforms smp_prepare_cpus() + * if present != possible (e.g. physical hotplug). */ init_cpu_present(cpu_possible_mask); @@ -408,7 +427,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus) * Initialise the SCU if there are more than one CPU * and let them know where to start. */ - platform_smp_prepare_cpus(max_cpus); + if (smp_ops.smp_prepare_cpus) + smp_ops.smp_prepare_cpus(max_cpus); } } @@ -416,7 +436,8 @@ static void (*smp_cross_call)(const struct cpumask *, unsigned int); void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int)) { - smp_cross_call = fn; + if (!smp_cross_call) + smp_cross_call = fn; } void arch_send_call_function_ipi_mask(const struct cpumask *mask) @@ -475,19 +496,11 @@ u64 smp_irq_stat_cpu(unsigned int cpu) */ static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent); -static void ipi_timer(void) -{ - struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent); - evt->event_handler(evt); -} - #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST -static void smp_timer_broadcast(const struct cpumask *mask) +void tick_broadcast(const struct cpumask *mask) { smp_cross_call(mask, IPI_TIMER); } -#else -#define smp_timer_broadcast NULL #endif static void broadcast_timer_set_mode(enum clock_event_mode mode, @@ -501,7 +514,7 @@ static void __cpuinit broadcast_timer_setup(struct clock_event_device *evt) evt->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_DUMMY; - evt->rating = 400; + evt->rating = 100; evt->mult = 1; evt->set_mode = broadcast_timer_set_mode; @@ -530,7 +543,6 @@ static void __cpuinit percpu_timer_setup(void) struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu); evt->cpumask = cpumask_of(cpu); - evt->broadcast = smp_timer_broadcast; if (!lt_ops || lt_ops->setup(evt)) broadcast_timer_setup(evt); @@ -596,11 +608,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs) case IPI_WAKEUP: break; +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST case IPI_TIMER: irq_enter(); - ipi_timer(); + tick_receive_broadcast(); irq_exit(); break; +#endif case IPI_RESCHEDULE: scheduler_ipi(); @@ -637,17 +651,6 @@ void smp_send_reschedule(int cpu) smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); } -#ifdef CONFIG_HOTPLUG_CPU -static void smp_kill_cpus(cpumask_t *mask) -{ - unsigned int cpu; - for_each_cpu(cpu, mask) - platform_cpu_kill(cpu); -} -#else -static void smp_kill_cpus(cpumask_t *mask) { } -#endif - void smp_send_stop(void) { unsigned long timeout; @@ -665,8 +668,6 @@ void smp_send_stop(void) if (num_online_cpus() > 1) pr_warning("SMP: failed to stop secondary CPUs\n"); - - smp_kill_cpus(&mask); } /* |