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Commit 3010673e authored by Jacob Pan's avatar Jacob Pan Committed by H. Peter Anvin
Browse files

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: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
LKML-Reference: <1267592494-7723-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent d8111cd9

arch/x86/kernel/apb_timer.c

+8 −4
Original line number Diff line number Diff line
@@ -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);