diff options
Diffstat (limited to 'arch/powerpc/kernel/time.c')
| -rw-r--r-- | arch/powerpc/kernel/time.c | 131 |
1 files changed, 88 insertions, 43 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index e71a0d8c597..d20947cf173 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -73,6 +73,7 @@ /* powerpc clocksource/clockevent code */ +#include <linux/clockchips.h> #include <linux/clocksource.h> static cycle_t rtc_read(void); @@ -97,6 +98,27 @@ static struct clocksource clocksource_timebase = { .read = timebase_read, }; +#define DECREMENTER_MAX 0x7fffffff + +static int decrementer_set_next_event(unsigned long evt, + struct clock_event_device *dev); +static void decrementer_set_mode(enum clock_event_mode mode, + struct clock_event_device *dev); + +static struct clock_event_device decrementer_clockevent = { + .name = "decrementer", + .rating = 200, + .shift = 32, + .mult = 0, /* To be filled in */ + .irq = 0, + .set_next_event = decrementer_set_next_event, + .set_mode = decrementer_set_mode, + .features = CLOCK_EVT_FEAT_ONESHOT, +}; + +static DEFINE_PER_CPU(struct clock_event_device, decrementers); +void init_decrementer_clockevent(void); + #ifdef CONFIG_PPC_ISERIES static unsigned long __initdata iSeries_recal_titan; static signed long __initdata iSeries_recal_tb; @@ -517,10 +539,12 @@ void __init iSeries_time_init_early(void) void timer_interrupt(struct pt_regs * regs) { struct pt_regs *old_regs; - int next_dec; int cpu = smp_processor_id(); - unsigned long ticks; - u64 tb_next_jiffy; + struct clock_event_device *evt = &per_cpu(decrementers, cpu); + + /* Ensure a positive value is written to the decrementer, or else + * some CPUs will continuue to take decrementer exceptions */ + set_dec(DECREMENTER_MAX); #ifdef CONFIG_PPC32 if (atomic_read(&ppc_n_lost_interrupts) != 0) @@ -530,7 +554,6 @@ void timer_interrupt(struct pt_regs * regs) old_regs = set_irq_regs(regs); irq_enter(); - profile_tick(CPU_PROFILING); calculate_steal_time(); #ifdef CONFIG_PPC_ISERIES @@ -538,44 +561,20 @@ void timer_interrupt(struct pt_regs * regs) get_lppaca()->int_dword.fields.decr_int = 0; #endif - while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu))) - >= tb_ticks_per_jiffy) { - /* Update last_jiffy */ - per_cpu(last_jiffy, cpu) += tb_ticks_per_jiffy; - /* Handle RTCL overflow on 601 */ - if (__USE_RTC() && per_cpu(last_jiffy, cpu) >= 1000000000) - per_cpu(last_jiffy, cpu) -= 1000000000; - - /* - * We cannot disable the decrementer, so in the period - * between this cpu's being marked offline in cpu_online_map - * and calling stop-self, it is taking timer interrupts. - * Avoid calling into the scheduler rebalancing code if this - * is the case. - */ - if (!cpu_is_offline(cpu)) - account_process_time(regs); - - /* - * No need to check whether cpu is offline here; boot_cpuid - * should have been fixed up by now. - */ - if (cpu != boot_cpuid) - continue; + /* + * We cannot disable the decrementer, so in the period + * between this cpu's being marked offline in cpu_online_map + * and calling stop-self, it is taking timer interrupts. + * Avoid calling into the scheduler rebalancing code if this + * is the case. + */ + if (!cpu_is_offline(cpu)) + account_process_time(regs); - write_seqlock(&xtime_lock); - tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy; - if (__USE_RTC() && tb_next_jiffy >= 1000000000) - tb_next_jiffy -= 1000000000; - if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) { - tb_last_jiffy = tb_next_jiffy; - do_timer(1); - } - write_sequnlock(&xtime_lock); - } - - next_dec = tb_ticks_per_jiffy - ticks; - set_dec(next_dec); + if (evt->event_handler) + evt->event_handler(evt); + else + evt->set_next_event(DECREMENTER_MAX, evt); #ifdef CONFIG_PPC_ISERIES if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) @@ -795,6 +794,53 @@ void __init clocksource_init(void) clock->name, clock->mult, clock->shift); } +static int decrementer_set_next_event(unsigned long evt, + struct clock_event_device *dev) +{ + set_dec(evt); + return 0; +} + +static void decrementer_set_mode(enum clock_event_mode mode, + struct clock_event_device *dev) +{ + if (mode != CLOCK_EVT_MODE_ONESHOT) + decrementer_set_next_event(DECREMENTER_MAX, dev); +} + +static void register_decrementer_clockevent(int cpu) +{ + struct clock_event_device *dec = &per_cpu(decrementers, cpu); + + *dec = decrementer_clockevent; + dec->cpumask = cpumask_of_cpu(cpu); + + printk(KERN_ERR "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n", + dec->name, dec->mult, dec->shift, cpu); + + clockevents_register_device(dec); +} + +void init_decrementer_clockevent(void) +{ + int cpu = smp_processor_id(); + + decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC, + decrementer_clockevent.shift); + decrementer_clockevent.max_delta_ns = + clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); + decrementer_clockevent.min_delta_ns = 1000; + + register_decrementer_clockevent(cpu); +} + +void secondary_cpu_time_init(void) +{ + /* FIME: Should make unrelatred change to move snapshot_timebase + * call here ! */ + register_decrementer_clockevent(smp_processor_id()); +} + /* This function is only called on the boot processor */ void __init time_init(void) { @@ -908,8 +954,7 @@ void __init time_init(void) if (!firmware_has_feature(FW_FEATURE_ISERIES)) clocksource_init(); - /* Not exact, but the timer interrupt takes care of this */ - set_dec(tb_ticks_per_jiffy); + init_decrementer_clockevent(); } |