From a1659d6d128a7e0c2985bce7c957b66af1f71181 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 14 Jul 2013 10:57:34 -0700 Subject: alpha: Switch to GENERIC_CLOCKEVENTS This allows us to get rid of some hacky code for SMP. Get rid of some cycle counter hackery that's now handled by generic code via clocksource + clock_event_device objects. Signed-off-by: Richard Henderson --- arch/alpha/Kconfig | 1 + arch/alpha/kernel/irq_alpha.c | 14 ------ arch/alpha/kernel/proto.h | 2 +- arch/alpha/kernel/smp.c | 33 ++----------- arch/alpha/kernel/time.c | 112 ++++++++++++++++++------------------------ 5 files changed, 53 insertions(+), 109 deletions(-) (limited to 'arch/alpha') diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 5d863d171b94..d39dc9b95a2c 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -16,6 +16,7 @@ config ALPHA select ARCH_WANT_IPC_PARSE_VERSION select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select GENERIC_CLOCKEVENTS select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER diff --git a/arch/alpha/kernel/irq_alpha.c b/arch/alpha/kernel/irq_alpha.c index 28e4429596f3..6990ddc0fbaf 100644 --- a/arch/alpha/kernel/irq_alpha.c +++ b/arch/alpha/kernel/irq_alpha.c @@ -66,21 +66,7 @@ do_entInt(unsigned long type, unsigned long vector, break; case 1: old_regs = set_irq_regs(regs); -#ifdef CONFIG_SMP - { - long cpu; - - smp_percpu_timer_interrupt(regs); - cpu = smp_processor_id(); - if (cpu != boot_cpuid) { - kstat_incr_irqs_this_cpu(RTC_IRQ, irq_to_desc(RTC_IRQ)); - } else { - handle_irq(RTC_IRQ); - } - } -#else handle_irq(RTC_IRQ); -#endif set_irq_regs(old_regs); return; case 2: diff --git a/arch/alpha/kernel/proto.h b/arch/alpha/kernel/proto.h index 3b250fa5f2c1..bc806893afe0 100644 --- a/arch/alpha/kernel/proto.h +++ b/arch/alpha/kernel/proto.h @@ -135,13 +135,13 @@ extern void unregister_srm_console(void); /* smp.c */ extern void setup_smp(void); extern void handle_ipi(struct pt_regs *); -extern void smp_percpu_timer_interrupt(struct pt_regs *); /* bios32.c */ /* extern void reset_for_srm(void); */ /* time.c */ extern irqreturn_t timer_interrupt(int irq, void *dev); +extern void init_clockevent(void); extern void common_init_rtc(void); extern unsigned long est_cycle_freq; diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 9dbbcb3b9146..99ac36d5de4e 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -138,9 +138,11 @@ smp_callin(void) /* Get our local ticker going. */ smp_setup_percpu_timer(cpuid); + init_clockevent(); /* Call platform-specific callin, if specified */ - if (alpha_mv.smp_callin) alpha_mv.smp_callin(); + if (alpha_mv.smp_callin) + alpha_mv.smp_callin(); /* All kernel threads share the same mm context. */ atomic_inc(&init_mm.mm_count); @@ -498,35 +500,6 @@ smp_cpus_done(unsigned int max_cpus) ((bogosum + 2500) / (5000/HZ)) % 100); } - -void -smp_percpu_timer_interrupt(struct pt_regs *regs) -{ - struct pt_regs *old_regs; - int cpu = smp_processor_id(); - unsigned long user = user_mode(regs); - struct cpuinfo_alpha *data = &cpu_data[cpu]; - - old_regs = set_irq_regs(regs); - - /* Record kernel PC. */ - profile_tick(CPU_PROFILING); - - if (!--data->prof_counter) { - /* We need to make like a normal interrupt -- otherwise - timer interrupts ignore the global interrupt lock, - which would be a Bad Thing. */ - irq_enter(); - - update_process_times(user); - - data->prof_counter = data->prof_multiplier; - - irq_exit(); - } - set_irq_regs(old_regs); -} - int setup_profiling_timer(unsigned int multiplier) { diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c index 0d72e2df4b0e..08ff3f502a76 100644 --- a/arch/alpha/kernel/time.c +++ b/arch/alpha/kernel/time.c @@ -42,6 +42,7 @@ #include #include #include +#include #include "proto.h" #include "irq_impl.h" @@ -49,25 +50,6 @@ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL(rtc_lock); -#define TICK_SIZE (tick_nsec / 1000) - -/* - * Shift amount by which scaled_ticks_per_cycle is scaled. Shifting - * by 48 gives us 16 bits for HZ while keeping the accuracy good even - * for large CPU clock rates. - */ -#define FIX_SHIFT 48 - -/* lump static variables together for more efficient access: */ -static struct { - /* cycle counter last time it got invoked */ - __u32 last_time; - /* ticks/cycle * 2^48 */ - unsigned long scaled_ticks_per_cycle; - /* partial unused tick */ - unsigned long partial_tick; -} state; - unsigned long est_cycle_freq; #ifdef CONFIG_IRQ_WORK @@ -96,49 +78,64 @@ static inline __u32 rpcc(void) return __builtin_alpha_rpcc(); } + + /* - * timer_interrupt() needs to keep up the real-time clock, - * as well as call the "xtime_update()" routine every clocktick + * The RTC as a clock_event_device primitive. */ -irqreturn_t timer_interrupt(int irq, void *dev) -{ - unsigned long delta; - __u32 now; - long nticks; -#ifndef CONFIG_SMP - /* Not SMP, do kernel PC profiling here. */ - profile_tick(CPU_PROFILING); -#endif +static DEFINE_PER_CPU(struct clock_event_device, cpu_ce); - /* - * Calculate how many ticks have passed since the last update, - * including any previous partial leftover. Save any resulting - * fraction for the next pass. - */ - now = rpcc(); - delta = now - state.last_time; - state.last_time = now; - delta = delta * state.scaled_ticks_per_cycle + state.partial_tick; - state.partial_tick = delta & ((1UL << FIX_SHIFT) - 1); - nticks = delta >> FIX_SHIFT; +irqreturn_t +timer_interrupt(int irq, void *dev) +{ + int cpu = smp_processor_id(); + struct clock_event_device *ce = &per_cpu(cpu_ce, cpu); - if (nticks) - xtime_update(nticks); + /* Don't run the hook for UNUSED or SHUTDOWN. */ + if (likely(ce->mode == CLOCK_EVT_MODE_PERIODIC)) + ce->event_handler(ce); if (test_irq_work_pending()) { clear_irq_work_pending(); irq_work_run(); } -#ifndef CONFIG_SMP - while (nticks--) - update_process_times(user_mode(get_irq_regs())); -#endif - return IRQ_HANDLED; } +static void +rtc_ce_set_mode(enum clock_event_mode mode, struct clock_event_device *ce) +{ + /* The mode member of CE is updated in generic code. + Since we only support periodic events, nothing to do. */ +} + +static int +rtc_ce_set_next_event(unsigned long evt, struct clock_event_device *ce) +{ + /* This hook is for oneshot mode, which we don't support. */ + return -EINVAL; +} + +void __init +init_clockevent(void) +{ + int cpu = smp_processor_id(); + struct clock_event_device *ce = &per_cpu(cpu_ce, cpu); + + *ce = (struct clock_event_device){ + .name = "rtc", + .features = CLOCK_EVT_FEAT_PERIODIC, + .rating = 100, + .cpumask = cpumask_of(cpu), + .set_mode = rtc_ce_set_mode, + .set_next_event = rtc_ce_set_next_event, + }; + + clockevents_config_and_register(ce, CONFIG_HZ, 0, 0); +} + void __init common_init_rtc(void) { @@ -372,22 +369,9 @@ time_init(void) clocksource_register_hz(&clocksource_rpcc, cycle_freq); #endif - /* From John Bowman : allow the values - to settle, as the Update-In-Progress bit going low isn't good - enough on some hardware. 2ms is our guess; we haven't found - bogomips yet, but this is close on a 500Mhz box. */ - __delay(1000000); - - if (HZ > (1<<16)) { - extern void __you_loose (void); - __you_loose(); - } - - state.last_time = cc1; - state.scaled_ticks_per_cycle - = ((unsigned long) HZ << FIX_SHIFT) / cycle_freq; - state.partial_tick = 0L; - /* Startup the timer source. */ alpha_mv.init_rtc(); + + /* Start up the clock event device. */ + init_clockevent(); } -- cgit v1.2.1