diff options
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 283 |
1 files changed, 86 insertions, 197 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 2e8957eac4d4..2cf1bf65b225 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -12,16 +12,13 @@ #ifndef _LINUX_HRTIMER_H #define _LINUX_HRTIMER_H -#include <linux/rbtree.h> -#include <linux/ktime.h> +#include <linux/hrtimer_defs.h> +#include <linux/hrtimer_types.h> #include <linux/init.h> #include <linux/list.h> -#include <linux/percpu.h> +#include <linux/percpu-defs.h> +#include <linux/rbtree.h> #include <linux/timer.h> -#include <linux/timerqueue.h> - -struct hrtimer_clock_base; -struct hrtimer_cpu_base; /* * Mode arguments of xxx_hrtimer functions: @@ -32,12 +29,15 @@ struct hrtimer_cpu_base; * when starting the timer) * HRTIMER_MODE_SOFT - Timer callback function will be executed in * soft irq context + * HRTIMER_MODE_HARD - Timer callback function will be executed in + * hard irq context even on PREEMPT_RT. */ enum hrtimer_mode { HRTIMER_MODE_ABS = 0x00, HRTIMER_MODE_REL = 0x01, HRTIMER_MODE_PINNED = 0x02, HRTIMER_MODE_SOFT = 0x04, + HRTIMER_MODE_HARD = 0x08, HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, @@ -48,14 +48,11 @@ enum hrtimer_mode { HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT, HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT, -}; + HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS | HRTIMER_MODE_HARD, + HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL | HRTIMER_MODE_HARD, -/* - * Return values for the callback function - */ -enum hrtimer_restart { - HRTIMER_NORESTART, /* Timer is not restarted */ - HRTIMER_RESTART, /* Timer must be restarted */ + HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD, + HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD, }; /* @@ -86,35 +83,6 @@ enum hrtimer_restart { #define HRTIMER_STATE_ENQUEUED 0x01 /** - * struct hrtimer - the basic hrtimer structure - * @node: timerqueue node, which also manages node.expires, - * the absolute expiry time in the hrtimers internal - * representation. The time is related to the clock on - * which the timer is based. Is setup by adding - * slack to the _softexpires value. For non range timers - * identical to _softexpires. - * @_softexpires: the absolute earliest expiry time of the hrtimer. - * The time which was given as expiry time when the timer - * was armed. - * @function: timer expiry callback function - * @base: pointer to the timer base (per cpu and per clock) - * @state: state information (See bit values above) - * @is_rel: Set if the timer was armed relative - * @is_soft: Set if hrtimer will be expired in soft interrupt context. - * - * The hrtimer structure must be initialized by hrtimer_init() - */ -struct hrtimer { - struct timerqueue_node node; - ktime_t _softexpires; - enum hrtimer_restart (*function)(struct hrtimer *); - struct hrtimer_clock_base *base; - u8 state; - u8 is_rel; - u8 is_soft; -}; - -/** * struct hrtimer_sleeper - simple sleeper structure * @timer: embedded timer structure * @task: task to wake up @@ -126,97 +94,6 @@ struct hrtimer_sleeper { struct task_struct *task; }; -#ifdef CONFIG_64BIT -# define __hrtimer_clock_base_align ____cacheline_aligned -#else -# define __hrtimer_clock_base_align -#endif - -/** - * struct hrtimer_clock_base - the timer base for a specific clock - * @cpu_base: per cpu clock base - * @index: clock type index for per_cpu support when moving a - * timer to a base on another cpu. - * @clockid: clock id for per_cpu support - * @seq: seqcount around __run_hrtimer - * @running: pointer to the currently running hrtimer - * @active: red black tree root node for the active timers - * @get_time: function to retrieve the current time of the clock - * @offset: offset of this clock to the monotonic base - */ -struct hrtimer_clock_base { - struct hrtimer_cpu_base *cpu_base; - unsigned int index; - clockid_t clockid; - seqcount_t seq; - struct hrtimer *running; - struct timerqueue_head active; - ktime_t (*get_time)(void); - ktime_t offset; -} __hrtimer_clock_base_align; - -enum hrtimer_base_type { - HRTIMER_BASE_MONOTONIC, - HRTIMER_BASE_REALTIME, - HRTIMER_BASE_BOOTTIME, - HRTIMER_BASE_TAI, - HRTIMER_BASE_MONOTONIC_SOFT, - HRTIMER_BASE_REALTIME_SOFT, - HRTIMER_BASE_BOOTTIME_SOFT, - HRTIMER_BASE_TAI_SOFT, - HRTIMER_MAX_CLOCK_BASES, -}; - -/** - * struct hrtimer_cpu_base - the per cpu clock bases - * @lock: lock protecting the base and associated clock bases - * and timers - * @cpu: cpu number - * @active_bases: Bitfield to mark bases with active timers - * @clock_was_set_seq: Sequence counter of clock was set events - * @hres_active: State of high resolution mode - * @in_hrtirq: hrtimer_interrupt() is currently executing - * @hang_detected: The last hrtimer interrupt detected a hang - * @softirq_activated: displays, if the softirq is raised - update of softirq - * related settings is not required then. - * @nr_events: Total number of hrtimer interrupt events - * @nr_retries: Total number of hrtimer interrupt retries - * @nr_hangs: Total number of hrtimer interrupt hangs - * @max_hang_time: Maximum time spent in hrtimer_interrupt - * @expires_next: absolute time of the next event, is required for remote - * hrtimer enqueue; it is the total first expiry time (hard - * and soft hrtimer are taken into account) - * @next_timer: Pointer to the first expiring timer - * @softirq_expires_next: Time to check, if soft queues needs also to be expired - * @softirq_next_timer: Pointer to the first expiring softirq based timer - * @clock_base: array of clock bases for this cpu - * - * Note: next_timer is just an optimization for __remove_hrtimer(). - * Do not dereference the pointer because it is not reliable on - * cross cpu removals. - */ -struct hrtimer_cpu_base { - raw_spinlock_t lock; - unsigned int cpu; - unsigned int active_bases; - unsigned int clock_was_set_seq; - unsigned int hres_active : 1, - in_hrtirq : 1, - hang_detected : 1, - softirq_activated : 1; -#ifdef CONFIG_HIGH_RES_TIMERS - unsigned int nr_events; - unsigned short nr_retries; - unsigned short nr_hangs; - unsigned int max_hang_time; -#endif - ktime_t expires_next; - struct hrtimer *next_timer; - ktime_t softirq_expires_next; - struct hrtimer *softirq_next_timer; - struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; -} ____cacheline_aligned; - static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) { timer->node.expires = time; @@ -277,14 +154,11 @@ static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) return ktime_to_ns(timer->node.expires); } -static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) -{ - return ktime_sub(timer->node.expires, timer->base->get_time()); -} +ktime_t hrtimer_cb_get_time(const struct hrtimer *timer); -static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) +static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) { - return timer->base->get_time(); + return ktime_sub(timer->node.expires, hrtimer_cb_get_time(timer)); } static inline int hrtimer_is_hres_active(struct hrtimer *timer) @@ -298,30 +172,12 @@ struct clock_event_device; extern void hrtimer_interrupt(struct clock_event_device *dev); -/* - * The resolution of the clocks. The resolution value is returned in - * the clock_getres() system call to give application programmers an - * idea of the (in)accuracy of timers. Timer values are rounded up to - * this resolution values. - */ -# define HIGH_RES_NSEC 1 -# define KTIME_HIGH_RES (HIGH_RES_NSEC) -# define MONOTONIC_RES_NSEC HIGH_RES_NSEC -# define KTIME_MONOTONIC_RES KTIME_HIGH_RES - -extern void clock_was_set_delayed(void); - extern unsigned int hrtimer_resolution; #else -# define MONOTONIC_RES_NSEC LOW_RES_NSEC -# define KTIME_MONOTONIC_RES KTIME_LOW_RES - #define hrtimer_resolution (unsigned int)LOW_RES_NSEC -static inline void clock_was_set_delayed(void) { } - #endif static inline ktime_t @@ -341,39 +197,47 @@ __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) static inline ktime_t hrtimer_expires_remaining_adjusted(const struct hrtimer *timer) { - return __hrtimer_expires_remaining_adjusted(timer, - timer->base->get_time()); + return __hrtimer_expires_remaining_adjusted(timer, hrtimer_cb_get_time(timer)); } -extern void clock_was_set(void); #ifdef CONFIG_TIMERFD extern void timerfd_clock_was_set(void); +extern void timerfd_resume(void); #else static inline void timerfd_clock_was_set(void) { } +static inline void timerfd_resume(void) { } #endif -extern void hrtimers_resume(void); DECLARE_PER_CPU(struct tick_device, tick_cpu_device); +#ifdef CONFIG_PREEMPT_RT +void hrtimer_cancel_wait_running(const struct hrtimer *timer); +#else +static inline void hrtimer_cancel_wait_running(struct hrtimer *timer) +{ + cpu_relax(); +} +#endif + +static inline enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused) +{ + return HRTIMER_NORESTART; +} /* Exported timer functions: */ /* Initialize timers: */ -extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); +extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode); +extern void hrtimer_setup_on_stack(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode); +extern void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode); #ifdef CONFIG_DEBUG_OBJECTS_TIMERS -extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); - extern void destroy_hrtimer_on_stack(struct hrtimer *timer); #else -static inline void hrtimer_init_on_stack(struct hrtimer *timer, - clockid_t which_clock, - enum hrtimer_mode mode) -{ - hrtimer_init(timer, which_clock, mode); -} static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } #endif @@ -409,6 +273,9 @@ static inline void hrtimer_start_expires(struct hrtimer *timer, hrtimer_start_range_ns(timer, soft, delta, mode); } +void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl, + enum hrtimer_mode mode); + static inline void hrtimer_restart(struct hrtimer *timer) { hrtimer_start_expires(timer, HRTIMER_MODE_ABS); @@ -417,6 +284,10 @@ static inline void hrtimer_restart(struct hrtimer *timer) /* Query timers: */ extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust); +/** + * hrtimer_get_remaining - get remaining time for the timer + * @timer: the timer to read + */ static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer) { return __hrtimer_get_remaining(timer, false); @@ -427,12 +298,18 @@ extern u64 hrtimer_next_event_without(const struct hrtimer *exclude); extern bool hrtimer_active(const struct hrtimer *timer); -/* - * Helper function to check, whether the timer is on one of the queues +/** + * hrtimer_is_queued - check, whether the timer is on one of the queues + * @timer: Timer to check + * + * Returns: True if the timer is queued, false otherwise + * + * The function can be used lockless, but it gives only a current snapshot. */ -static inline int hrtimer_is_queued(struct hrtimer *timer) +static inline bool hrtimer_is_queued(struct hrtimer *timer) { - return timer->state & HRTIMER_STATE_ENQUEUED; + /* The READ_ONCE pairs with the update functions of timer->state */ + return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED); } /* @@ -444,44 +321,55 @@ static inline int hrtimer_callback_running(struct hrtimer *timer) return timer->base->running == timer; } +/** + * 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; +} + /* Forward a hrtimer so it expires after now: */ extern u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); /** - * hrtimer_forward_now - forward the timer expiry so it expires after now + * hrtimer_forward_now() - forward the timer expiry so it expires after now * @timer: hrtimer to forward * @interval: the interval to forward * - * Forward the timer expiry so it will expire after the current time - * of the hrtimer clock base. Returns the number of overruns. - * - * Can be safely called from the callback function of @timer. If - * called from other contexts @timer must neither be enqueued nor - * running the callback and the caller needs to take care of - * serialization. - * - * Note: This only updates the timer expiry value and does not requeue - * the timer. + * It is a variant of hrtimer_forward(). The timer will expire after the current + * time of the hrtimer clock base. See hrtimer_forward() for details. */ static inline u64 hrtimer_forward_now(struct hrtimer *timer, ktime_t interval) { - return hrtimer_forward(timer, timer->base->get_time(), interval); + return hrtimer_forward(timer, hrtimer_cb_get_time(timer), interval); } /* Precise sleep: */ extern int nanosleep_copyout(struct restart_block *, struct timespec64 *); -extern long hrtimer_nanosleep(const struct timespec64 *rqtp, - const enum hrtimer_mode mode, +extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, const clockid_t clockid); -extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, - struct task_struct *tsk); - extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta, - const enum hrtimer_mode mode); + const enum hrtimer_mode mode); extern int schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, const enum hrtimer_mode mode, @@ -498,10 +386,11 @@ extern void __init hrtimers_init(void); extern void sysrq_timer_list_show(void); int hrtimers_prepare_cpu(unsigned int cpu); +int hrtimers_cpu_starting(unsigned int cpu); #ifdef CONFIG_HOTPLUG_CPU -int hrtimers_dead_cpu(unsigned int cpu); +int hrtimers_cpu_dying(unsigned int cpu); #else -#define hrtimers_dead_cpu NULL +#define hrtimers_cpu_dying NULL #endif #endif |