/* * 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/wait.h> /* * Mode arguments of xxx_hrtimer functions: */ enum hrtimer_mode { HRTIMER_ABS, /* Time value is absolute */ HRTIMER_REL, /* Time value is relative to now */ }; enum hrtimer_restart { HRTIMER_NORESTART, HRTIMER_RESTART, }; #define HRTIMER_INACTIVE ((void *)1UL) struct hrtimer_base; /** * struct hrtimer - the basic hrtimer structure * @node: red black tree node for time ordered insertion * @expires: the absolute expiry time in the hrtimers internal * representation. The time is related to the clock on * which the timer is based. * @function: timer expiry callback function * @base: pointer to the timer base (per cpu and per clock) * * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE() */ struct hrtimer { struct rb_node node; ktime_t expires; int (*function)(struct hrtimer *); struct hrtimer_base *base; }; /** * 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; }; /** * struct hrtimer_base - the timer base for a specific clock * @index: clock type index for per_cpu support when moving a timer * to a base on another cpu. * @lock: lock protecting the base and associated timers * @active: red black tree root node for the active timers * @first: pointer to the timer node which expires first * @resolution: the resolution of the clock, in nanoseconds * @get_time: function to retrieve the current time of the clock * @get_softirq_time: function to retrieve the current time from the softirq * @curr_timer: the timer which is executing a callback right now * @softirq_time: the time when running the hrtimer queue in the softirq */ struct hrtimer_base { clockid_t index; spinlock_t lock; struct rb_root active; struct rb_node *first; ktime_t resolution; ktime_t (*get_time)(void); ktime_t (*get_softirq_time)(void); struct hrtimer *curr_timer; ktime_t softirq_time; }; /* * clock_was_set() is a NOP for non- high-resolution systems. The * time-sorted order guarantees that a timer does not expire early and * is expired in the next softirq when the clock was advanced. */ #define clock_was_set() do { } while (0) /* Exported timer functions: */ /* Initialize timers: */ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); /* Basic timer operations: */ extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode); extern int hrtimer_cancel(struct hrtimer *timer); extern int hrtimer_try_to_cancel(struct hrtimer *timer); #define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS) /* Query timers: */ extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); #ifdef CONFIG_NO_IDLE_HZ extern ktime_t hrtimer_get_next_event(void); #endif static inline int hrtimer_active(const struct hrtimer *timer) { return rb_parent(&timer->node) != &timer->node; } /* Forward a hrtimer so it expires after now: */ extern unsigned long hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); /* Precise sleep: */ extern long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, const enum hrtimer_mode mode, const clockid_t clockid); extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *tsk); /* Soft interrupt function to run the hrtimer queues: */ extern void hrtimer_run_queues(void); /* Bootup initialization: */ extern void __init hrtimers_init(void); #endif