153 lines
4.3 KiB
C
153 lines
4.3 KiB
C
/*
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* include/linux/hrtimer.h
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*
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* hrtimers - High-resolution kernel timers
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*
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* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
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* Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
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*
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* data type definitions, declarations, prototypes
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*
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* Started by: Thomas Gleixner and Ingo Molnar
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*
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* For licencing details see kernel-base/COPYING
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*/
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#ifndef _LINUX_HRTIMER_H
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#define _LINUX_HRTIMER_H
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#include <linux/rbtree.h>
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#include <linux/ktime.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/wait.h>
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/*
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* Mode arguments of xxx_hrtimer functions:
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*/
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enum hrtimer_mode {
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HRTIMER_ABS, /* Time value is absolute */
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HRTIMER_REL, /* Time value is relative to now */
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};
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enum hrtimer_restart {
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HRTIMER_NORESTART,
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HRTIMER_RESTART,
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};
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#define HRTIMER_INACTIVE ((void *)1UL)
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struct hrtimer_base;
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/**
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* struct hrtimer - the basic hrtimer structure
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* @node: red black tree node for time ordered insertion
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* @expires: the absolute expiry time in the hrtimers internal
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* representation. The time is related to the clock on
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* which the timer is based.
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* @function: timer expiry callback function
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* @base: pointer to the timer base (per cpu and per clock)
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*
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* The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
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*/
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struct hrtimer {
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struct rb_node node;
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ktime_t expires;
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int (*function)(struct hrtimer *);
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struct hrtimer_base *base;
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};
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/**
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* struct hrtimer_sleeper - simple sleeper structure
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* @timer: embedded timer structure
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* @task: task to wake up
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*
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* task is set to NULL, when the timer expires.
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*/
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struct hrtimer_sleeper {
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struct hrtimer timer;
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struct task_struct *task;
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};
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/**
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* struct hrtimer_base - the timer base for a specific clock
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* @index: clock type index for per_cpu support when moving a timer
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* to a base on another cpu.
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* @lock: lock protecting the base and associated timers
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* @active: red black tree root node for the active timers
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* @first: pointer to the timer node which expires first
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* @resolution: the resolution of the clock, in nanoseconds
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* @get_time: function to retrieve the current time of the clock
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* @get_softirq_time: function to retrieve the current time from the softirq
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* @curr_timer: the timer which is executing a callback right now
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* @softirq_time: the time when running the hrtimer queue in the softirq
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* @lock_key: the lock_class_key for use with lockdep
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*/
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struct hrtimer_base {
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clockid_t index;
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spinlock_t lock;
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struct rb_root active;
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struct rb_node *first;
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ktime_t resolution;
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ktime_t (*get_time)(void);
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ktime_t (*get_softirq_time)(void);
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struct hrtimer *curr_timer;
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ktime_t softirq_time;
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struct lock_class_key lock_key;
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};
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/*
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* clock_was_set() is a NOP for non- high-resolution systems. The
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* time-sorted order guarantees that a timer does not expire early and
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* is expired in the next softirq when the clock was advanced.
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*/
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#define clock_was_set() do { } while (0)
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/* Exported timer functions: */
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/* Initialize timers: */
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extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
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enum hrtimer_mode mode);
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/* Basic timer operations: */
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extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
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const enum hrtimer_mode mode);
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extern int hrtimer_cancel(struct hrtimer *timer);
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extern int hrtimer_try_to_cancel(struct hrtimer *timer);
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#define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS)
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/* Query timers: */
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extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
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extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
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#ifdef CONFIG_NO_IDLE_HZ
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extern ktime_t hrtimer_get_next_event(void);
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#endif
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static inline int hrtimer_active(const struct hrtimer *timer)
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{
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return rb_parent(&timer->node) != &timer->node;
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}
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/* Forward a hrtimer so it expires after now: */
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extern unsigned long
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hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
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/* Precise sleep: */
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extern long hrtimer_nanosleep(struct timespec *rqtp,
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struct timespec __user *rmtp,
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const enum hrtimer_mode mode,
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const clockid_t clockid);
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extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
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extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
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struct task_struct *tsk);
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/* Soft interrupt function to run the hrtimer queues: */
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extern void hrtimer_run_queues(void);
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/* Bootup initialization: */
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extern void __init hrtimers_init(void);
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#endif
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