diff options
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 122 |
1 files changed, 41 insertions, 81 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 74adbd4e7003..29072d89e5cb 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -12,7 +12,7 @@ #ifndef _LINUX_HRTIMER_H #define _LINUX_HRTIMER_H -#include <linux/hrtimer_defs.h> +#include <linux/hrtimer_rearm.h> #include <linux/hrtimer_types.h> #include <linux/init.h> #include <linux/list.h> @@ -31,6 +31,13 @@ * soft irq context * HRTIMER_MODE_HARD - Timer callback function will be executed in * hard irq context even on PREEMPT_RT. + * HRTIMER_MODE_LAZY_REARM - Avoid reprogramming if the timer was the + * first expiring timer and is moved into the + * future. Special mode for the HRTICK timer to + * avoid extensive reprogramming of the hardware, + * which is expensive in virtual machines. Risks + * a pointless expiry, but that's better than + * reprogramming on every context switch, */ enum hrtimer_mode { HRTIMER_MODE_ABS = 0x00, @@ -38,6 +45,7 @@ enum hrtimer_mode { HRTIMER_MODE_PINNED = 0x02, HRTIMER_MODE_SOFT = 0x04, HRTIMER_MODE_HARD = 0x08, + HRTIMER_MODE_LAZY_REARM = 0x10, HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, @@ -55,33 +63,6 @@ enum hrtimer_mode { HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD, }; -/* - * Values to track state of the timer - * - * Possible states: - * - * 0x00 inactive - * 0x01 enqueued into rbtree - * - * The callback state is not part of the timer->state because clearing it would - * mean touching the timer after the callback, this makes it impossible to free - * the timer from the callback function. - * - * Therefore we track the callback state in: - * - * timer->base->cpu_base->running == timer - * - * On SMP it is possible to have a "callback function running and enqueued" - * status. It happens for example when a posix timer expired and the callback - * queued a signal. Between dropping the lock which protects the posix timer - * and reacquiring the base lock of the hrtimer, another CPU can deliver the - * signal and rearm the timer. - * - * All state transitions are protected by cpu_base->lock. - */ -#define HRTIMER_STATE_INACTIVE 0x00 -#define HRTIMER_STATE_ENQUEUED 0x01 - /** * struct hrtimer_sleeper - simple sleeper structure * @timer: embedded timer structure @@ -134,11 +115,6 @@ static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) return timer->_softexpires; } -static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) -{ - return ktime_to_ns(timer->node.expires); -} - ktime_t hrtimer_cb_get_time(const struct hrtimer *timer); static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) @@ -146,24 +122,23 @@ static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) return ktime_sub(timer->node.expires, hrtimer_cb_get_time(timer)); } -static inline int hrtimer_is_hres_active(struct hrtimer *timer) -{ - return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ? - timer->base->cpu_base->hres_active : 0; -} - #ifdef CONFIG_HIGH_RES_TIMERS +extern unsigned int hrtimer_resolution; struct clock_event_device; extern void hrtimer_interrupt(struct clock_event_device *dev); -extern unsigned int hrtimer_resolution; +extern struct static_key_false hrtimer_highres_enabled_key; -#else +static inline bool hrtimer_highres_enabled(void) +{ + return static_branch_likely(&hrtimer_highres_enabled_key); +} +#else /* CONFIG_HIGH_RES_TIMERS */ #define hrtimer_resolution (unsigned int)LOW_RES_NSEC - -#endif +static inline bool hrtimer_highres_enabled(void) { return false; } +#endif /* !CONFIG_HIGH_RES_TIMERS */ static inline ktime_t __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) @@ -230,6 +205,9 @@ static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, u64 range_ns, const enum hrtimer_mode mode); +extern bool hrtimer_start_range_ns_user(struct hrtimer *timer, ktime_t tim, + u64 range_ns, const enum hrtimer_mode mode); + /** * hrtimer_start - (re)start an hrtimer * @timer: the timer to be added @@ -247,17 +225,28 @@ static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim, extern int hrtimer_cancel(struct hrtimer *timer); extern int hrtimer_try_to_cancel(struct hrtimer *timer); -static inline void hrtimer_start_expires(struct hrtimer *timer, - enum hrtimer_mode mode) +static inline void hrtimer_start_expires(struct hrtimer *timer, enum hrtimer_mode mode) { - u64 delta; ktime_t soft, hard; + u64 delta; + soft = hrtimer_get_softexpires(timer); hard = hrtimer_get_expires(timer); delta = ktime_to_ns(ktime_sub(hard, soft)); hrtimer_start_range_ns(timer, soft, delta, mode); } +static inline bool hrtimer_start_expires_user(struct hrtimer *timer, enum hrtimer_mode mode) +{ + ktime_t soft, hard; + u64 delta; + + soft = hrtimer_get_softexpires(timer); + hard = hrtimer_get_expires(timer); + delta = ktime_to_ns(ktime_sub(hard, soft)); + return hrtimer_start_range_ns_user(timer, soft, delta, mode); +} + void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl, enum hrtimer_mode mode); @@ -278,8 +267,8 @@ static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer) return __hrtimer_get_remaining(timer, false); } -extern u64 hrtimer_get_next_event(void); -extern u64 hrtimer_next_event_without(const struct hrtimer *exclude); +extern ktime_t hrtimer_get_next_event(void); +extern ktime_t hrtimer_next_event_without(const struct hrtimer *exclude); extern bool hrtimer_active(const struct hrtimer *timer); @@ -293,41 +282,12 @@ extern bool hrtimer_active(const struct hrtimer *timer); */ static inline bool hrtimer_is_queued(struct hrtimer *timer) { - /* The READ_ONCE pairs with the update functions of timer->state */ - return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED); -} - -/* - * Helper function to check, whether the timer is running the callback - * function - */ -static inline int hrtimer_callback_running(struct hrtimer *timer) -{ - return timer->base->running == timer; + /* The READ_ONCE pairs with the update functions of timer->is_queued */ + return READ_ONCE(timer->is_queued); } -/** - * hrtimer_update_function - Update the timer's callback function - * @timer: Timer to update - * @function: New callback function - * - * Only safe to call if the timer is not enqueued. Can be called in the callback function if the - * timer is not enqueued at the same time (see the comments above HRTIMER_STATE_ENQUEUED). - */ -static inline void hrtimer_update_function(struct hrtimer *timer, - enum hrtimer_restart (*function)(struct hrtimer *)) -{ -#ifdef CONFIG_PROVE_LOCKING - guard(raw_spinlock_irqsave)(&timer->base->cpu_base->lock); - - if (WARN_ON_ONCE(hrtimer_is_queued(timer))) - return; - - if (WARN_ON_ONCE(!function)) - return; -#endif - ACCESS_PRIVATE(timer, function) = function; -} +void hrtimer_update_function(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *)); /* Forward a hrtimer so it expires after now: */ extern u64 |