From 3010673ef5f7bef4b4685566a0713de1b4306c93 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Tue, 2 Mar 2010 21:01:34 -0800 Subject: [PATCH] x86, mrst: Fix APB timer per cpu clockevent The current APB timer code incorrectly registers a static copy of the clockevent device for the boot CPU. The per cpu clockevent should be used instead. This bug was hidden by zero-initialized data; as such it did not get exposed in testing, but was discovered by code review. Signed-off-by: Jacob Pan LKML-Reference: <1267592494-7723-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apb_timer.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c index 83a345b0256c..6f27f8b75795 100644 --- a/arch/x86/kernel/apb_timer.c +++ b/arch/x86/kernel/apb_timer.c @@ -84,9 +84,10 @@ struct apbt_dev { int disable_apbt_percpu __cpuinitdata; +static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev); + #ifdef CONFIG_SMP static unsigned int apbt_num_timers_used; -static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev); static struct apbt_dev *apbt_devs; #endif @@ -302,6 +303,7 @@ static void apbt_disable_int(int n) static int __init apbt_clockevent_register(void) { struct sfi_timer_table_entry *mtmr; + struct apbt_dev *adev = &__get_cpu_var(cpu_apbt_dev); mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM); if (mtmr == NULL) { @@ -329,22 +331,24 @@ static int __init apbt_clockevent_register(void) * global if not used for per cpu timer. */ apbt_clockevent.cpumask = cpumask_of(smp_processor_id()); + adev->num = smp_processor_id(); + memcpy(&adev->evt, &apbt_clockevent, sizeof(struct clock_event_device)); if (disable_apbt_percpu) { apbt_clockevent.rating = APBT_CLOCKEVENT_RATING - 100; - global_clock_event = &apbt_clockevent; + global_clock_event = &adev->evt; printk(KERN_DEBUG "%s clockevent registered as global\n", global_clock_event->name); } if (request_irq(apbt_clockevent.irq, apbt_interrupt_handler, IRQF_TIMER | IRQF_DISABLED | IRQF_NOBALANCING, - apbt_clockevent.name, &apbt_clockevent)) { + apbt_clockevent.name, adev)) { printk(KERN_ERR "Failed request IRQ for APBT%d\n", apbt_clockevent.irq); } - clockevents_register_device(&apbt_clockevent); + clockevents_register_device(&adev->evt); /* Start APBT 0 interrupts */ apbt_enable_int(APBT_CLOCKEVENT0_NUM);