diff options
Diffstat (limited to 'arch/mn10300/kernel/time.c')
| -rw-r--r-- | arch/mn10300/kernel/time.c | 112 |
1 files changed, 85 insertions, 27 deletions
diff --git a/arch/mn10300/kernel/time.c b/arch/mn10300/kernel/time.c index 8f7f6d22783d..f860a340acc9 100644 --- a/arch/mn10300/kernel/time.c +++ b/arch/mn10300/kernel/time.c @@ -17,29 +17,18 @@ #include <linux/smp.h> #include <linux/profile.h> #include <linux/cnt32_to_63.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> #include <asm/irq.h> #include <asm/div64.h> #include <asm/processor.h> #include <asm/intctl-regs.h> #include <asm/rtc.h> - -#ifdef CONFIG_MN10300_RTC -unsigned long mn10300_ioclk; /* system I/O clock frequency */ -unsigned long mn10300_iobclk; /* system I/O clock frequency */ -unsigned long mn10300_tsc_per_HZ; /* number of ioclks per jiffy */ -#endif /* CONFIG_MN10300_RTC */ +#include "internal.h" static unsigned long mn10300_last_tsc; /* time-stamp counter at last time * interrupt occurred */ -static irqreturn_t timer_interrupt(int irq, void *dev_id); - -static struct irqaction timer_irq = { - .handler = timer_interrupt, - .flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER, - .name = "timer", -}; - static unsigned long sched_clock_multiplier; /* @@ -54,9 +43,12 @@ unsigned long long sched_clock(void) unsigned long tsc, tmp; unsigned product[3]; /* 96-bit intermediate value */ + /* cnt32_to_63() is not safe with preemption */ + preempt_disable(); + /* read the TSC value */ - tsc = 0 - get_cycles(); /* get_cycles() counts down */ + tsc = get_cycles(); /* expand to 64-bits. * - sched_clock() must be called once a minute or better or the @@ -64,6 +56,8 @@ unsigned long long sched_clock(void) */ tsc64.ll = cnt32_to_63(tsc) & 0x7fffffffffffffffULL; + preempt_enable(); + /* scale the 64-bit TSC value to a nanosecond value via a 96-bit * intermediate */ @@ -90,6 +84,20 @@ static void __init mn10300_sched_clock_init(void) __muldiv64u(NSEC_PER_SEC, 1 << 16, MN10300_TSCCLK); } +/** + * local_timer_interrupt - Local timer interrupt handler + * + * Handle local timer interrupts for this CPU. They may have been propagated + * to this CPU from the CPU that actually gets them by way of an IPI. + */ +irqreturn_t local_timer_interrupt(void) +{ + profile_tick(CPU_PROFILING); + update_process_times(user_mode(get_irq_regs())); + return IRQ_HANDLED; +} + +#ifndef CONFIG_GENERIC_TIME /* * advance the kernel's time keeping clocks (xtime and jiffies) * - we use Timer 0 & 1 cascaded as a clock to nudge us the next time @@ -98,27 +106,73 @@ static void __init mn10300_sched_clock_init(void) static irqreturn_t timer_interrupt(int irq, void *dev_id) { unsigned tsc, elapse; + irqreturn_t ret; write_seqlock(&xtime_lock); while (tsc = get_cycles(), - elapse = mn10300_last_tsc - tsc, /* time elapsed since last + elapse = tsc - mn10300_last_tsc, /* time elapsed since last * tick */ elapse > MN10300_TSC_PER_HZ ) { - mn10300_last_tsc -= MN10300_TSC_PER_HZ; + mn10300_last_tsc += MN10300_TSC_PER_HZ; /* advance the kernel's time tracking system */ - profile_tick(CPU_PROFILING); do_timer(1); } write_sequnlock(&xtime_lock); - update_process_times(user_mode(get_irq_regs())); + ret = local_timer_interrupt(); +#ifdef CONFIG_SMP + send_IPI_allbutself(LOCAL_TIMER_IPI); +#endif + return ret; +} - return IRQ_HANDLED; +static struct irqaction timer_irq = { + .handler = timer_interrupt, + .flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER, + .name = "timer", +}; +#endif /* CONFIG_GENERIC_TIME */ + +#ifdef CONFIG_CSRC_MN10300 +void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock) +{ + u64 temp; + u32 shift; + + /* Find a shift value */ + for (shift = 32; shift > 0; shift--) { + temp = (u64) NSEC_PER_SEC << shift; + do_div(temp, clock); + if ((temp >> 32) == 0) + break; + } + cs->shift = shift; + cs->mult = (u32) temp; } +#endif + +#if CONFIG_CEVT_MN10300 +void __cpuinit clockevent_set_clock(struct clock_event_device *cd, + unsigned int clock) +{ + u64 temp; + u32 shift; + + /* Find a shift value */ + for (shift = 32; shift > 0; shift--) { + temp = (u64) clock << shift; + do_div(temp, NSEC_PER_SEC); + if ((temp >> 32) == 0) + break; + } + cd->shift = shift; + cd->mult = (u32) temp; +} +#endif /* * initialise the various timers used by the main part of the kernel @@ -131,21 +185,25 @@ void __init time_init(void) */ TMPSCNT |= TMPSCNT_ENABLE; +#ifdef CONFIG_GENERIC_TIME + init_clocksource(); +#else startup_timestamp_counter(); +#endif printk(KERN_INFO "timestamp counter I/O clock running at %lu.%02lu" " (calibrated against RTC)\n", MN10300_TSCCLK / 1000000, (MN10300_TSCCLK / 10000) % 100); - mn10300_last_tsc = TMTSCBC; - - /* use timer 0 & 1 cascaded to tick at as close to HZ as possible */ - setup_irq(TMJCIRQ, &timer_irq); + mn10300_last_tsc = read_timestamp_counter(); - set_intr_level(TMJCIRQ, TMJCICR_LEVEL); - - startup_jiffies_counter(); +#ifdef CONFIG_GENERIC_CLOCKEVENTS + init_clockevents(); +#else + reload_jiffies_counter(MN10300_JC_PER_HZ - 1); + setup_jiffies_interrupt(TMJCIRQ, &timer_irq, CONFIG_TIMER_IRQ_LEVEL); +#endif #ifdef CONFIG_MN10300_WD_TIMER /* start the watchdog timer */ |