diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/apic_64.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c index 40938ef99dc2..2c2807abe1d4 100644 --- a/arch/x86/kernel/apic_64.c +++ b/arch/x86/kernel/apic_64.c @@ -25,6 +25,7 @@ #include <linux/sysdev.h> #include <linux/module.h> #include <linux/ioport.h> +#include <linux/clockchips.h> #include <asm/atomic.h> #include <asm/smp.h> @@ -57,6 +58,77 @@ static struct resource lapic_resource = { static unsigned int calibration_result; +static int lapic_next_event(unsigned long delta, + struct clock_event_device *evt); +static void lapic_timer_setup(enum clock_event_mode mode, + struct clock_event_device *evt); + +static void lapic_timer_broadcast(cpumask_t mask); + +static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen); + +static struct clock_event_device lapic_clockevent = { + .name = "lapic", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT + | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY, + .shift = 32, + .set_mode = lapic_timer_setup, + .set_next_event = lapic_next_event, + .broadcast = lapic_timer_broadcast, + .rating = 100, + .irq = -1, +}; +static DEFINE_PER_CPU(struct clock_event_device, lapic_events); + +static int lapic_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + apic_write(APIC_TMICT, delta); + return 0; +} + +static void lapic_timer_setup(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long flags; + unsigned int v; + + /* Lapic used as dummy for broadcast ? */ + if (evt->features & CLOCK_EVT_FEAT_DUMMY) + return; + + local_irq_save(flags); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + case CLOCK_EVT_MODE_ONESHOT: + __setup_APIC_LVTT(calibration_result, + mode != CLOCK_EVT_MODE_PERIODIC, 1); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + v = apic_read(APIC_LVTT); + v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); + apic_write(APIC_LVTT, v); + break; + case CLOCK_EVT_MODE_RESUME: + /* Nothing to do here */ + break; + } + + local_irq_restore(flags); +} + +/* + * Local APIC timer broadcast function + */ +static void lapic_timer_broadcast(cpumask_t mask) +{ +#ifdef CONFIG_SMP + send_IPI_mask(mask, LOCAL_TIMER_VECTOR); +#endif +} + /* * cpu_mask that denotes the CPUs that needs timer interrupt coming in as * IPIs in place of local APIC timers @@ -866,6 +938,13 @@ static void __init calibrate_APIC_clock(void) printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n", result / 1000 / 1000, result / 1000 % 1000); + /* Calculate the scaled math multiplication factor */ + lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC, 32); + lapic_clockevent.max_delta_ns = + clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); + lapic_clockevent.min_delta_ns = + clockevent_delta2ns(0xF, &lapic_clockevent); + calibration_result = result / HZ; } |