From 5388a6b266e9c3357353332ba0cd5549082887f1 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Jul 2010 13:19:43 +0100 Subject: ARM: SMP: Always enable clock event broadcast support The TWD local timers are unable to wake up the CPU when it is placed into a low power mode, eg. C3. Therefore, we need to adapt things such that the TWD code can cope with this. We do this by always providing a broadcast tick function, and marking the fact that the TWD local timer will stop in low power modes. This means that when the CPU is placed into a low power mode, the core timer code marks this fact, and allows an IPI to be given to the core. Tested-by: Santosh Shilimkar Signed-off-by: Russell King Cc: Catalin Marinas Cc: Thomas Gleixner --- arch/arm/kernel/smp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index b8c3d0f689d9..0170e248a1dd 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -429,7 +429,11 @@ static void smp_timer_broadcast(const struct cpumask *mask) { send_ipi_message(mask, IPI_TIMER); } +#else +#define smp_timer_broadcast NULL +#endif +#ifndef CONFIG_LOCAL_TIMERS static void broadcast_timer_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { @@ -444,7 +448,6 @@ static void local_timer_setup(struct clock_event_device *evt) evt->rating = 400; evt->mult = 1; evt->set_mode = broadcast_timer_set_mode; - evt->broadcast = smp_timer_broadcast; clockevents_register_device(evt); } @@ -456,6 +459,7 @@ 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; local_timer_setup(evt); } -- cgit v1.2.1 From 3d3f78d752bfada5b6041f2f7bd0833d8bdf7a4a Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Jul 2010 13:31:27 +0100 Subject: ARM: call machine_shutdown() from machine_halt(), etc x86 calls machine_shutdown() from the various machine_*() calls which take the machine down ready for halting, restarting, etc, and uses this to bring the system safely to a point where those actions can be performed. Such actions are stopping the secondary CPUs. So, change the ARM implementation of these to reflect what x86 does. This solves kexec problems on ARM SMP platforms, where the secondary CPUs were left running across the kexec call. Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 0170e248a1dd..40dc74f2b27f 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -471,10 +471,13 @@ static DEFINE_SPINLOCK(stop_lock); */ static void ipi_cpu_stop(unsigned int cpu) { - spin_lock(&stop_lock); - printk(KERN_CRIT "CPU%u: stopping\n", cpu); - dump_stack(); - spin_unlock(&stop_lock); + if (system_state == SYSTEM_BOOTING || + system_state == SYSTEM_RUNNING) { + spin_lock(&stop_lock); + printk(KERN_CRIT "CPU%u: stopping\n", cpu); + dump_stack(); + spin_unlock(&stop_lock); + } set_cpu_online(cpu, false); -- cgit v1.2.1