| /* |
| * include/linux/hrtimer.h |
| * |
| * hrtimers - High-resolution kernel timers |
| * |
| * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> |
| * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar |
| * |
| * data type definitions, declarations, prototypes |
| * |
| * Started by: Thomas Gleixner and Ingo Molnar |
| * |
| * For licencing details see kernel-base/COPYING |
| */ |
| #ifndef _LINUX_HRTIMER_H |
| #define _LINUX_HRTIMER_H |
| |
| #include <linux/rbtree.h> |
| #include <linux/ktime.h> |
| #include <linux/init.h> |
| #include <linux/list.h> |
| #include <linux/percpu.h> |
| #include <linux/timer.h> |
| #include <linux/timerqueue.h> |
| |
| struct hrtimer_clock_base; |
| struct hrtimer_cpu_base; |
| |
| /* |
| * Mode arguments of xxx_hrtimer functions: |
| */ |
| enum hrtimer_mode { |
| HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */ |
| HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */ |
| HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */ |
| HRTIMER_MODE_ABS_PINNED = 0x02, |
| HRTIMER_MODE_REL_PINNED = 0x03, |
| }; |
| |
| /* |
| * Return values for the callback function |
| */ |
| enum hrtimer_restart { |
| HRTIMER_NORESTART, /* Timer is not restarted */ |
| HRTIMER_RESTART, /* Timer must be restarted */ |
| }; |
| |
| /* |
| * Values to track state of the timer |
| * |
| * Possible states: |
| * |
| * 0x00 inactive |
| * 0x01 enqueued into rbtree |
| * 0x02 timer is pinned to a cpu |
| * |
| * 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 |
| #define HRTIMER_PINNED_SHIFT 1 |
| #define HRTIMER_STATE_PINNED (1 << HRTIMER_PINNED_SHIFT) |
| |
| /** |
| * 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 |
| * |
| * 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; |
| }; |
| |
| /** |
| * struct hrtimer_sleeper - simple sleeper structure |
| * @timer: embedded timer structure |
| * @task: task to wake up |
| * |
| * task is set to NULL, when the timer expires. |
| */ |
| struct hrtimer_sleeper { |
| struct hrtimer timer; |
| struct task_struct *task; |
| }; |
| |
| #ifdef CONFIG_64BIT |
| # define HRTIMER_CLOCK_BASE_ALIGN 64 |
| #else |
| # define HRTIMER_CLOCK_BASE_ALIGN 32 |
| #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 |
| * @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; |
| int index; |
| clockid_t clockid; |
| struct timerqueue_head active; |
| ktime_t (*get_time)(void); |
| ktime_t offset; |
| } __attribute__((__aligned__(HRTIMER_CLOCK_BASE_ALIGN))); |
| |
| enum hrtimer_base_type { |
| HRTIMER_BASE_MONOTONIC, |
| HRTIMER_BASE_REALTIME, |
| HRTIMER_BASE_BOOTTIME, |
| HRTIMER_BASE_TAI, |
| HRTIMER_MAX_CLOCK_BASES, |
| }; |
| |
| /* |
| * struct hrtimer_cpu_base - the per cpu clock bases |
| * @lock: lock protecting the base and associated clock bases |
| * and timers |
| * @seq: seqcount around __run_hrtimer |
| * @running: pointer to the currently running hrtimer |
| * @cpu: cpu number |
| * @active_bases: Bitfield to mark bases with active timers |
| * @clock_was_set_seq: Sequence counter of clock was set events |
| * @migration_enabled: The migration of hrtimers to other cpus is enabled |
| * @nohz_active: The nohz functionality is enabled |
| * @expires_next: absolute time of the next event which was scheduled |
| * via clock_set_next_event() |
| * @next_timer: Pointer to the first expiring timer |
| * @in_hrtirq: hrtimer_interrupt() is currently executing |
| * @hres_active: State of high resolution mode |
| * @hang_detected: The last hrtimer interrupt detected a hang |
| * @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 |
| * @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; |
| seqcount_t seq; |
| struct hrtimer *running; |
| unsigned int cpu; |
| unsigned int active_bases; |
| unsigned int clock_was_set_seq; |
| bool migration_enabled; |
| bool nohz_active; |
| #ifdef CONFIG_HIGH_RES_TIMERS |
| unsigned int in_hrtirq : 1, |
| hres_active : 1, |
| hang_detected : 1; |
| ktime_t expires_next; |
| struct hrtimer *next_timer; |
| unsigned int nr_events; |
| unsigned int nr_retries; |
| unsigned int nr_hangs; |
| unsigned int max_hang_time; |
| #endif |
| struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; |
| } ____cacheline_aligned; |
| |
| static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) |
| { |
| BUILD_BUG_ON(sizeof(struct hrtimer_clock_base) > HRTIMER_CLOCK_BASE_ALIGN); |
| |
| timer->node.expires = time; |
| timer->_softexpires = time; |
| } |
| |
| static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) |
| { |
| timer->_softexpires = time; |
| timer->node.expires = ktime_add_safe(time, delta); |
| } |
| |
| static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta) |
| { |
| timer->_softexpires = time; |
| timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); |
| } |
| |
| static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) |
| { |
| timer->node.expires = tv64; |
| timer->_softexpires = tv64; |
| } |
| |
| static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) |
| { |
| timer->node.expires = ktime_add_safe(timer->node.expires, time); |
| timer->_softexpires = ktime_add_safe(timer->_softexpires, time); |
| } |
| |
| static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) |
| { |
| timer->node.expires = ktime_add_ns(timer->node.expires, ns); |
| timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); |
| } |
| |
| static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) |
| { |
| return timer->node.expires; |
| } |
| |
| static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) |
| { |
| return timer->_softexpires; |
| } |
| |
| static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) |
| { |
| return timer->node.expires; |
| } |
| static inline s64 hrtimer_get_softexpires_tv64(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); |
| } |
| |
| static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) |
| { |
| return ktime_sub(timer->node.expires, timer->base->get_time()); |
| } |
| |
| static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) |
| { |
| return timer->base->get_time(); |
| } |
| |
| #ifdef CONFIG_HIGH_RES_TIMERS |
| struct clock_event_device; |
| |
| extern void hrtimer_interrupt(struct clock_event_device *dev); |
| |
| static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
| { |
| return timer->base->cpu_base->hres_active; |
| } |
| |
| /* |
| * 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 int hrtimer_is_hres_active(struct hrtimer *timer) |
| { |
| return 0; |
| } |
| |
| static inline void clock_was_set_delayed(void) { } |
| |
| #endif |
| |
| static inline ktime_t |
| __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) |
| { |
| ktime_t rem = ktime_sub(timer->node.expires, now); |
| |
| /* |
| * Adjust relative timers for the extra we added in |
| * hrtimer_start_range_ns() to prevent short timeouts. |
| */ |
| if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel) |
| rem -= hrtimer_resolution; |
| return rem; |
| } |
| |
| static inline ktime_t |
| hrtimer_expires_remaining_adjusted(const struct hrtimer *timer) |
| { |
| return __hrtimer_expires_remaining_adjusted(timer, |
| timer->base->get_time()); |
| } |
| |
| extern void clock_was_set(void); |
| #ifdef CONFIG_TIMERFD |
| extern void timerfd_clock_was_set(void); |
| #else |
| static inline void timerfd_clock_was_set(void) { } |
| #endif |
| extern void hrtimers_resume(void); |
| |
| DECLARE_PER_CPU(struct tick_device, tick_cpu_device); |
| |
| |
| /* Exported timer functions: */ |
| |
| /* To be used from cpusets, only */ |
| extern void hrtimer_quiesce_cpu(void *cpup); |
| |
| /* Initialize timers: */ |
| extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, |
| 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 |
| |
| /* Basic timer operations: */ |
| extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
| u64 range_ns, const enum hrtimer_mode mode); |
| |
| /** |
| * hrtimer_start - (re)start an hrtimer on the current CPU |
| * @timer: the timer to be added |
| * @tim: expiry time |
| * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or |
| * relative (HRTIMER_MODE_REL) |
| */ |
| static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim, |
| const enum hrtimer_mode mode) |
| { |
| hrtimer_start_range_ns(timer, tim, 0, mode); |
| } |
| |
| 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) |
| { |
| u64 delta; |
| ktime_t soft, hard; |
| 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 void hrtimer_restart(struct hrtimer *timer) |
| { |
| hrtimer_start_expires(timer, HRTIMER_MODE_ABS); |
| } |
| |
| /* Query timers: */ |
| extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust); |
| |
| 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 bool hrtimer_active(const struct hrtimer *timer); |
| |
| /** |
| * 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 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->cpu_base->running == timer; |
| } |
| |
| /* 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 |
| * @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. |
| */ |
| static inline u64 hrtimer_forward_now(struct hrtimer *timer, |
| ktime_t interval) |
| { |
| return hrtimer_forward(timer, timer->base->get_time(), 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, |
| 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); |
| extern int schedule_hrtimeout_range_clock(ktime_t *expires, |
| u64 delta, |
| const enum hrtimer_mode mode, |
| int clock); |
| extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); |
| |
| /* Soft interrupt function to run the hrtimer queues: */ |
| extern void hrtimer_run_queues(void); |
| |
| /* Bootup initialization: */ |
| extern void __init hrtimers_init(void); |
| |
| /* Show pending timers: */ |
| extern void sysrq_timer_list_show(void); |
| |
| int hrtimers_prepare_cpu(unsigned int cpu); |
| #ifdef CONFIG_HOTPLUG_CPU |
| int hrtimers_dead_cpu(unsigned int cpu); |
| #else |
| #define hrtimers_dead_cpu NULL |
| #endif |
| |
| #endif |