diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index fd0dc30c9f154..cc07d2777bbe6 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -165,6 +165,7 @@ enum hrtimer_base_type { * @lock: lock protecting the base and associated clock bases * and timers * @active_bases: Bitfield to mark bases with active timers + * @clock_was_set: Indicates that clock was set from irq context. * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() * @hres_active: State of high resolution mode @@ -177,7 +178,8 @@ enum hrtimer_base_type { */ struct hrtimer_cpu_base { raw_spinlock_t lock; - unsigned long active_bases; + unsigned int active_bases; + unsigned int clock_was_set; #ifdef CONFIG_HIGH_RES_TIMERS ktime_t expires_next; int hres_active; @@ -286,6 +288,8 @@ extern void hrtimer_peek_ahead_timers(void); # define MONOTONIC_RES_NSEC HIGH_RES_NSEC # define KTIME_MONOTONIC_RES KTIME_HIGH_RES +extern void clock_was_set_delayed(void); + #else # define MONOTONIC_RES_NSEC LOW_RES_NSEC @@ -306,6 +310,9 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer) { return 0; } + +static inline void clock_was_set_delayed(void) { } + #endif extern void clock_was_set(void); @@ -320,6 +327,7 @@ extern ktime_t ktime_get(void); extern ktime_t ktime_get_real(void); extern ktime_t ktime_get_boottime(void); extern ktime_t ktime_get_monotonic_offset(void); +extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot); DECLARE_PER_CPU(struct tick_device, tick_cpu_device); diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index ae34bf51682b4..6db7a5ed52b58 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -657,6 +657,14 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, return 0; } +static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) +{ + ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; + ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; + + return ktime_get_update_offsets(offs_real, offs_boot); +} + /* * Retrigger next event is called after clock was set * @@ -665,22 +673,12 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, static void retrigger_next_event(void *arg) { struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases); - struct timespec realtime_offset, xtim, wtm, sleep; if (!hrtimer_hres_active()) return; - /* Optimized out for !HIGH_RES */ - get_xtime_and_monotonic_and_sleep_offset(&xtim, &wtm, &sleep); - set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec); - - /* Adjust CLOCK_REALTIME offset */ raw_spin_lock(&base->lock); - base->clock_base[HRTIMER_BASE_REALTIME].offset = - timespec_to_ktime(realtime_offset); - base->clock_base[HRTIMER_BASE_BOOTTIME].offset = - timespec_to_ktime(sleep); - + hrtimer_update_base(base); hrtimer_force_reprogram(base, 0); raw_spin_unlock(&base->lock); } @@ -710,13 +708,25 @@ static int hrtimer_switch_to_hres(void) base->clock_base[i].resolution = KTIME_HIGH_RES; tick_setup_sched_timer(); - /* "Retrigger" the interrupt to get things going */ retrigger_next_event(NULL); local_irq_restore(flags); return 1; } +/* + * Called from timekeeping code to reprogramm the hrtimer interrupt + * device. If called from the timer interrupt context we defer it to + * softirq context. + */ +void clock_was_set_delayed(void) +{ + struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); + + cpu_base->clock_was_set = 1; + __raise_softirq_irqoff(HRTIMER_SOFTIRQ); +} + #else static inline int hrtimer_hres_active(void) { return 0; } @@ -1250,11 +1260,10 @@ void hrtimer_interrupt(struct clock_event_device *dev) cpu_base->nr_events++; dev->next_event.tv64 = KTIME_MAX; - entry_time = now = ktime_get(); + raw_spin_lock(&cpu_base->lock); + entry_time = now = hrtimer_update_base(cpu_base); retry: expires_next.tv64 = KTIME_MAX; - - raw_spin_lock(&cpu_base->lock); /* * We set expires_next to KTIME_MAX here with cpu_base->lock * held to prevent that a timer is enqueued in our queue via @@ -1330,8 +1339,12 @@ void hrtimer_interrupt(struct clock_event_device *dev) * We need to prevent that we loop forever in the hrtimer * interrupt routine. We give it 3 attempts to avoid * overreacting on some spurious event. + * + * Acquire base lock for updating the offsets and retrieving + * the current time. */ - now = ktime_get(); + raw_spin_lock(&cpu_base->lock); + now = hrtimer_update_base(cpu_base); cpu_base->nr_retries++; if (++retries < 3) goto retry; @@ -1343,6 +1356,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) */ cpu_base->nr_hangs++; cpu_base->hang_detected = 1; + raw_spin_unlock(&cpu_base->lock); delta = ktime_sub(now, entry_time); if (delta.tv64 > cpu_base->max_hang_time.tv64) cpu_base->max_hang_time = delta; @@ -1395,6 +1409,13 @@ void hrtimer_peek_ahead_timers(void) static void run_hrtimer_softirq(struct softirq_action *h) { + struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); + + if (cpu_base->clock_was_set) { + cpu_base->clock_was_set = 0; + clock_was_set(); + } + hrtimer_peek_ahead_timers(); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6f46a00a1e8a7..269b1fe5f2ae2 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -70,6 +70,12 @@ struct timekeeper { /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ struct timespec raw_time; + /* Offset clock monotonic -> clock realtime */ + ktime_t offs_real; + + /* Offset clock monotonic -> clock boottime */ + ktime_t offs_boot; + /* Seqlock for all timekeeper values */ seqlock_t lock; }; @@ -172,6 +178,14 @@ static inline s64 timekeeping_get_ns_raw(void) return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); } +static void update_rt_offset(void) +{ + struct timespec tmp, *wtm = &timekeeper.wall_to_monotonic; + + set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec); + timekeeper.offs_real = timespec_to_ktime(tmp); +} + /* must hold write on timekeeper.lock */ static void timekeeping_update(bool clearntp) { @@ -179,6 +193,7 @@ static void timekeeping_update(bool clearntp) timekeeper.ntp_error = 0; ntp_clear(); } + update_rt_offset(); update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, timekeeper.mult); } @@ -604,6 +619,7 @@ void __init timekeeping_init(void) } set_normalized_timespec(&timekeeper.wall_to_monotonic, -boot.tv_sec, -boot.tv_nsec); + update_rt_offset(); timekeeper.total_sleep_time.tv_sec = 0; timekeeper.total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&timekeeper.lock, flags); @@ -612,6 +628,12 @@ void __init timekeeping_init(void) /* time in seconds when suspend began */ static struct timespec timekeeping_suspend_time; +static void update_sleep_time(struct timespec t) +{ + timekeeper.total_sleep_time = t; + timekeeper.offs_boot = timespec_to_ktime(t); +} + /** * __timekeeping_inject_sleeptime - Internal function to add sleep interval * @delta: pointer to a timespec delta value @@ -630,8 +652,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta) timekeeper.xtime = timespec_add(timekeeper.xtime, *delta); timekeeper.wall_to_monotonic = timespec_sub(timekeeper.wall_to_monotonic, *delta); - timekeeper.total_sleep_time = timespec_add( - timekeeper.total_sleep_time, *delta); + update_sleep_time(timespec_add(timekeeper.total_sleep_time, *delta)); } @@ -963,6 +984,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) leap = second_overflow(timekeeper.xtime.tv_sec); timekeeper.xtime.tv_sec += leap; timekeeper.wall_to_monotonic.tv_sec -= leap; + if (leap) + clock_was_set_delayed(); } /* Accumulate raw time */ @@ -1079,6 +1102,8 @@ static void update_wall_time(void) leap = second_overflow(timekeeper.xtime.tv_sec); timekeeper.xtime.tv_sec += leap; timekeeper.wall_to_monotonic.tv_sec -= leap; + if (leap) + clock_was_set_delayed(); } timekeeping_update(false); @@ -1246,6 +1271,40 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, } while (read_seqretry(&timekeeper.lock, seq)); } +#ifdef CONFIG_HIGH_RES_TIMERS +/** + * ktime_get_update_offsets - hrtimer helper + * @offs_real: pointer to storage for monotonic -> realtime offset + * @offs_boot: pointer to storage for monotonic -> boottime offset + * + * Returns current monotonic time and updates the offsets + * Called from hrtimer_interupt() or retrigger_next_event() + */ +ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) +{ + ktime_t now; + unsigned int seq; + u64 secs, nsecs; + + do { + seq = read_seqbegin(&timekeeper.lock); + + secs = timekeeper.xtime.tv_sec; + nsecs = timekeeper.xtime.tv_nsec; + nsecs += timekeeping_get_ns(); + /* If arch requires, add in gettimeoffset() */ + nsecs += arch_gettimeoffset(); + + *offs_real = timekeeper.offs_real; + *offs_boot = timekeeper.offs_boot; + } while (read_seqretry(&timekeeper.lock, seq)); + + now = ktime_add_ns(ktime_set(secs, 0), nsecs); + now = ktime_sub(now, *offs_real); + return now; +} +#endif + /** * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format */