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Diffstat (limited to 'arch/x86/kernel/apic_64.c')
-rw-r--r--arch/x86/kernel/apic_64.c90
1 files changed, 50 insertions, 40 deletions
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 2c2807abe1d..b0237caff71 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -857,25 +857,12 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
static void setup_APIC_timer(void)
{
- unsigned long flags;
- int irqen;
+ struct clock_event_device *levt = &__get_cpu_var(lapic_events);
- local_irq_save(flags);
+ memcpy(levt, &lapic_clockevent, sizeof(*levt));
+ levt->cpumask = cpumask_of_cpu(smp_processor_id());
- irqen = ! cpu_isset(smp_processor_id(),
- timer_interrupt_broadcast_ipi_mask);
- __setup_APIC_LVTT(calibration_result, 0, irqen);
- /* Turn off PIT interrupt if we use APIC timer as main timer.
- Only works with the PM timer right now
- TBD fix it for HPET too. */
- if ((pmtmr_ioport != 0) &&
- smp_processor_id() == boot_cpu_id &&
- apic_runs_main_timer == 1 &&
- !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
- stop_timer_interrupt();
- apic_runs_main_timer++;
- }
- local_irq_restore(flags);
+ clockevents_register_device(levt);
}
/*
@@ -950,18 +937,34 @@ static void __init calibrate_APIC_clock(void)
void __init setup_boot_APIC_clock (void)
{
+ /*
+ * The local apic timer can be disabled via the kernel commandline.
+ * Register the lapic timer as a dummy clock event source on SMP
+ * systems, so the broadcast mechanism is used. On UP systems simply
+ * ignore it.
+ */
if (disable_apic_timer) {
printk(KERN_INFO "Disabling APIC timer\n");
+ /* No broadcast on UP ! */
+ if (num_possible_cpus() > 1)
+ setup_APIC_timer();
return;
}
printk(KERN_INFO "Using local APIC timer interrupts.\n");
- using_apic_timer = 1;
-
calibrate_APIC_clock();
+
/*
- * Now set up the timer for real.
+ * If nmi_watchdog is set to IO_APIC, we need the
+ * PIT/HPET going. Otherwise register lapic as a dummy
+ * device.
*/
+ if (nmi_watchdog != NMI_IO_APIC)
+ lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+ else
+ printk(KERN_WARNING "APIC timer registered as dummy,"
+ " due to nmi_watchdog=1!\n");
+
setup_APIC_timer();
}
@@ -1073,22 +1076,34 @@ void setup_APIC_extended_lvt(unsigned char lvt_off, unsigned char vector,
void smp_local_timer_interrupt(void)
{
- profile_tick(CPU_PROFILING);
-#ifdef CONFIG_SMP
- update_process_times(user_mode(get_irq_regs()));
-#endif
- if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
- main_timer_handler();
+ int cpu = smp_processor_id();
+ struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
+
/*
- * We take the 'long' return path, and there every subsystem
- * grabs the appropriate locks (kernel lock/ irq lock).
- *
- * We might want to decouple profiling from the 'long path',
- * and do the profiling totally in assembly.
+ * Normally we should not be here till LAPIC has been initialized but
+ * in some cases like kdump, its possible that there is a pending LAPIC
+ * timer interrupt from previous kernel's context and is delivered in
+ * new kernel the moment interrupts are enabled.
*
- * Currently this isn't too much of an issue (performance wise),
- * we can take more than 100K local irqs per second on a 100 MHz P5.
+ * Interrupts are enabled early and LAPIC is setup much later, hence
+ * its possible that when we get here evt->event_handler is NULL.
+ * Check for event_handler being NULL and discard the interrupt as
+ * spurious.
*/
+ if (!evt->event_handler) {
+ printk(KERN_WARNING
+ "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
+ /* Switch it off */
+ lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
+ return;
+ }
+
+ /*
+ * the NMI deadlock-detector uses this.
+ */
+ add_pda(apic_timer_irqs, 1);
+
+ evt->event_handler(evt);
}
/*
@@ -1104,11 +1119,6 @@ void smp_apic_timer_interrupt(struct pt_regs *regs)
struct pt_regs *old_regs = set_irq_regs(regs);
/*
- * the NMI deadlock-detector uses this.
- */
- add_pda(apic_timer_irqs, 1);
-
- /*
* NOTE! We'd better ACK the irq immediately,
* because timer handling can be slow.
*/
@@ -1291,7 +1301,7 @@ static __init int setup_noapictimer(char *str)
static __init int setup_apicmaintimer(char *str)
{
apic_runs_main_timer = 1;
- nohpet = 1;
+
return 1;
}
__setup("apicmaintimer", setup_apicmaintimer);
@@ -1307,7 +1317,7 @@ static __init int setup_apicpmtimer(char *s)
{
apic_calibrate_pmtmr = 1;
notsc_setup(NULL);
- return setup_apicmaintimer(NULL);
+ return 0;
}
__setup("apicpmtimer", setup_apicpmtimer);