diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/Kconfig | 2 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 125 | ||||
| -rw-r--r-- | kernel/time/tick-broadcast.c | 4 | ||||
| -rw-r--r-- | kernel/time/tick-common.c | 4 | ||||
| -rw-r--r-- | kernel/time/tick-internal.h | 2 | ||||
| -rw-r--r-- | kernel/time/tick-oneshot.c | 77 |
6 files changed, 121 insertions, 93 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index f06a8a3..b26c2228 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -27,3 +27,5 @@ config GENERIC_CLOCKEVENTS_BUILD default y depends on GENERIC_CLOCKEVENTS || GENERIC_CLOCKEVENTS_MIGR +config GENERIC_CLOCKEVENTS_MIN_ADJUST + bool diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index e4c699d..713ef94 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -94,42 +94,139 @@ void clockevents_shutdown(struct clock_event_device *dev) dev->next_event.tv64 = KTIME_MAX; } +#ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST + +/* Limit min_delta to a jiffie */ +#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ) + +/** + * clockevents_increase_min_delta - raise minimum delta of a clock event device + * @dev: device to increase the minimum delta + * + * Returns 0 on success, -ETIME when the minimum delta reached the limit. + */ +static int clockevents_increase_min_delta(struct clock_event_device *dev) +{ + /* Nothing to do if we already reached the limit */ + if (dev->min_delta_ns >= MIN_DELTA_LIMIT) { + printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n"); + dev->next_event.tv64 = KTIME_MAX; + return -ETIME; + } + + if (dev->min_delta_ns < 5000) + dev->min_delta_ns = 5000; + else + dev->min_delta_ns += dev->min_delta_ns >> 1; + + if (dev->min_delta_ns > MIN_DELTA_LIMIT) + dev->min_delta_ns = MIN_DELTA_LIMIT; + + printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n", + dev->name ? dev->name : "?", + (unsigned long long) dev->min_delta_ns); + return 0; +} + +/** + * clockevents_program_min_delta - Set clock event device to the minimum delay. + * @dev: device to program + * + * Returns 0 on success, -ETIME when the retry loop failed. + */ +static int clockevents_program_min_delta(struct clock_event_device *dev) +{ + unsigned long long clc; + int64_t delta; + int i; + + for (i = 0;;) { + delta = dev->min_delta_ns; + dev->next_event = ktime_add_ns(ktime_get(), delta); + + if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) + return 0; + + dev->retries++; + clc = ((unsigned long long) delta * dev->mult) >> dev->shift; + if (dev->set_next_event((unsigned long) clc, dev) == 0) + return 0; + + if (++i > 2) { + /* + * We tried 3 times to program the device with the + * given min_delta_ns. Try to increase the minimum + * delta, if that fails as well get out of here. + */ + if (clockevents_increase_min_delta(dev)) + return -ETIME; + i = 0; + } + } +} + +#else /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ + +/** + * clockevents_program_min_delta - Set clock event device to the minimum delay. + * @dev: device to program + * + * Returns 0 on success, -ETIME when the retry loop failed. + */ +static int clockevents_program_min_delta(struct clock_event_device *dev) +{ + unsigned long long clc; + int64_t delta; + + delta = dev->min_delta_ns; + dev->next_event = ktime_add_ns(ktime_get(), delta); + + if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) + return 0; + + dev->retries++; + clc = ((unsigned long long) delta * dev->mult) >> dev->shift; + return dev->set_next_event((unsigned long) clc, dev); +} + +#endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */ + /** * clockevents_program_event - Reprogram the clock event device. + * @dev: device to program * @expires: absolute expiry time (monotonic clock) + * @force: program minimum delay if expires can not be set * * Returns 0 on success, -ETIME when the event is in the past. */ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, - ktime_t now) + bool force) { unsigned long long clc; int64_t delta; + int rc; if (unlikely(expires.tv64 < 0)) { WARN_ON_ONCE(1); return -ETIME; } - delta = ktime_to_ns(ktime_sub(expires, now)); - - if (delta <= 0) - return -ETIME; - dev->next_event = expires; if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) return 0; - if (delta > dev->max_delta_ns) - delta = dev->max_delta_ns; - if (delta < dev->min_delta_ns) - delta = dev->min_delta_ns; + delta = ktime_to_ns(ktime_sub(expires, ktime_get())); + if (delta <= 0) + return force ? clockevents_program_min_delta(dev) : -ETIME; - clc = delta * dev->mult; - clc >>= dev->shift; + delta = min(delta, (int64_t) dev->max_delta_ns); + delta = max(delta, (int64_t) dev->min_delta_ns); - return dev->set_next_event((unsigned long) clc, dev); + clc = ((unsigned long long) delta * dev->mult) >> dev->shift; + rc = dev->set_next_event((unsigned long) clc, dev); + + return (rc && force) ? clockevents_program_min_delta(dev) : rc; } /** @@ -258,7 +355,7 @@ int clockevents_update_freq(struct clock_event_device *dev, u32 freq) if (dev->mode != CLOCK_EVT_MODE_ONESHOT) return 0; - return clockevents_program_event(dev, dev->next_event, ktime_get()); + return clockevents_program_event(dev, dev->next_event, false); } /* diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index c7218d1..f954282 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -194,7 +194,7 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) for (next = dev->next_event; ;) { next = ktime_add(next, tick_period); - if (!clockevents_program_event(dev, next, ktime_get())) + if (!clockevents_program_event(dev, next, false)) return; tick_do_periodic_broadcast(); } @@ -373,7 +373,7 @@ static int tick_broadcast_set_event(ktime_t expires, int force) { struct clock_event_device *bc = tick_broadcast_device.evtdev; - return tick_dev_program_event(bc, expires, force); + return clockevents_program_event(bc, expires, force); } int tick_resume_broadcast_oneshot(struct clock_event_device *bc) diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 119528d..da6c9ec 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -94,7 +94,7 @@ void tick_handle_periodic(struct clock_event_device *dev) */ next = ktime_add(dev->next_event, tick_period); for (;;) { - if (!clockevents_program_event(dev, next, ktime_get())) + if (!clockevents_program_event(dev, next, false)) return; /* * Have to be careful here. If we're in oneshot mode, @@ -137,7 +137,7 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast) clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); for (;;) { - if (!clockevents_program_event(dev, next, ktime_get())) + if (!clockevents_program_event(dev, next, false)) return; next = ktime_add(next, tick_period); } diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 1009b06..4e265b90 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -26,8 +26,6 @@ extern void clockevents_shutdown(struct clock_event_device *dev); extern void tick_setup_oneshot(struct clock_event_device *newdev, void (*handler)(struct clock_event_device *), ktime_t nextevt); -extern int tick_dev_program_event(struct clock_event_device *dev, - ktime_t expires, int force); extern int tick_program_event(ktime_t expires, int force); extern void tick_oneshot_notify(void); extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *)); diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index 2d04411..8241090 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -21,74 +21,6 @@ #include "tick-internal.h" -/* Limit min_delta to a jiffie */ -#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ) - -static int tick_increase_min_delta(struct clock_event_device *dev) -{ - /* Nothing to do if we already reached the limit */ - if (dev->min_delta_ns >= MIN_DELTA_LIMIT) - return -ETIME; - - if (dev->min_delta_ns < 5000) - dev->min_delta_ns = 5000; - else - dev->min_delta_ns += dev->min_delta_ns >> 1; - - if (dev->min_delta_ns > MIN_DELTA_LIMIT) - dev->min_delta_ns = MIN_DELTA_LIMIT; - - printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n", - dev->name ? dev->name : "?", - (unsigned long long) dev->min_delta_ns); - return 0; -} - -/** - * tick_program_event internal worker function - */ -int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires, - int force) -{ - ktime_t now = ktime_get(); - int i; - - for (i = 0;;) { - int ret = clockevents_program_event(dev, expires, now); - - if (!ret || !force) - return ret; - - dev->retries++; - /* - * We tried 3 times to program the device with the given - * min_delta_ns. If that's not working then we increase it - * and emit a warning. - */ - if (++i > 2) { - /* Increase the min. delta and try again */ - if (tick_increase_min_delta(dev)) { - /* - * Get out of the loop if min_delta_ns - * hit the limit already. That's - * better than staying here forever. - * - * We clear next_event so we have a - * chance that the box survives. - */ - printk(KERN_WARNING - "CE: Reprogramming failure. Giving up\n"); - dev->next_event.tv64 = KTIME_MAX; - return -ETIME; - } - i = 0; - } - - now = ktime_get(); - expires = ktime_add_ns(now, dev->min_delta_ns); - } -} - /** * tick_program_event */ @@ -96,7 +28,7 @@ int tick_program_event(ktime_t expires, int force) { struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); - return tick_dev_program_event(dev, expires, force); + return clockevents_program_event(dev, expires, force); } /** @@ -104,11 +36,10 @@ int tick_program_event(ktime_t expires, int force) */ void tick_resume_oneshot(void) { - struct tick_device *td = &__get_cpu_var(tick_cpu_device); - struct clock_event_device *dev = td->evtdev; + struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); - tick_program_event(ktime_get(), 1); + clockevents_program_event(dev, ktime_get(), true); } /** @@ -120,7 +51,7 @@ void tick_setup_oneshot(struct clock_event_device *newdev, { newdev->event_handler = handler; clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT); - tick_dev_program_event(newdev, next_event, 1); + clockevents_program_event(newdev, next_event, true); } /** |
