From b8ce33590687888ebb900d09557b8807c4539022 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 12 Oct 2007 23:04:07 +0200 Subject: x86_64: convert to clock events Finally switch to the clockevents code. Share code with i386 for hpet and PIT. Signed-off-by: Thomas Gleixner Signed-off-by: Chris Wright Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven --- arch/x86/kernel/apic_64.c | 90 ++++++++++++++++++++++++++--------------------- 1 file changed, 50 insertions(+), 40 deletions(-) (limited to 'arch/x86/kernel/apic_64.c') diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c index 2c2807abe1d4..b0237caff712 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); } /* @@ -1103,11 +1118,6 @@ 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); -- cgit v1.2.3