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Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001/*
2 * include/linux/hrtimer.h
3 *
4 * hrtimers - High-resolution kernel timers
5 *
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
8 *
9 * data type definitions, declarations, prototypes
10 *
11 * Started by: Thomas Gleixner and Ingo Molnar
12 *
13 * For licencing details see kernel-base/COPYING
14 */
15#ifndef _LINUX_HRTIMER_H
16#define _LINUX_HRTIMER_H
17
18#include <linux/rbtree.h>
19#include <linux/ktime.h>
20#include <linux/init.h>
21#include <linux/list.h>
22#include <linux/wait.h>
23
24/*
25 * Mode arguments of xxx_hrtimer functions:
26 */
27enum hrtimer_mode {
28 HRTIMER_ABS, /* Time value is absolute */
29 HRTIMER_REL, /* Time value is relative to now */
30};
31
32enum hrtimer_restart {
33 HRTIMER_NORESTART,
34 HRTIMER_RESTART,
35};
36
Roman Zippelb75f7a52006-03-26 01:38:09 -080037#define HRTIMER_INACTIVE ((void *)1UL)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080038
39struct hrtimer_base;
40
41/**
42 * struct hrtimer - the basic hrtimer structure
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080043 * @node: red black tree node for time ordered insertion
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080044 * @expires: the absolute expiry time in the hrtimers internal
45 * representation. The time is related to the clock on
46 * which the timer is based.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080047 * @function: timer expiry callback function
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080048 * @base: pointer to the timer base (per cpu and per clock)
49 *
50 * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
51 */
52struct hrtimer {
53 struct rb_node node;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080054 ktime_t expires;
Roman Zippel05cfb612006-03-26 01:38:12 -080055 int (*function)(struct hrtimer *);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080056 struct hrtimer_base *base;
57};
58
59/**
Thomas Gleixner00362e32006-03-31 02:31:17 -080060 * struct hrtimer_sleeper - simple sleeper structure
Thomas Gleixner00362e32006-03-31 02:31:17 -080061 * @timer: embedded timer structure
62 * @task: task to wake up
63 *
64 * task is set to NULL, when the timer expires.
65 */
66struct hrtimer_sleeper {
67 struct hrtimer timer;
68 struct task_struct *task;
69};
70
71/**
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080072 * struct hrtimer_base - the timer base for a specific clock
Thomas Gleixner92127c72006-03-26 01:38:05 -080073 * @index: clock type index for per_cpu support when moving a timer
74 * to a base on another cpu.
75 * @lock: lock protecting the base and associated timers
76 * @active: red black tree root node for the active timers
77 * @first: pointer to the timer node which expires first
78 * @resolution: the resolution of the clock, in nanoseconds
79 * @get_time: function to retrieve the current time of the clock
Martin Waitza5802902006-04-02 13:59:55 +020080 * @get_softirq_time: function to retrieve the current time from the softirq
Thomas Gleixner92127c72006-03-26 01:38:05 -080081 * @curr_timer: the timer which is executing a callback right now
82 * @softirq_time: the time when running the hrtimer queue in the softirq
Henrik Kretzschmar6dba2832006-09-06 00:03:40 -070083 * @lock_key: the lock_class_key for use with lockdep
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080084 */
85struct hrtimer_base {
86 clockid_t index;
87 spinlock_t lock;
88 struct rb_root active;
Thomas Gleixner288867e2006-01-12 11:25:54 +010089 struct rb_node *first;
Thomas Gleixnere2787632006-01-12 11:36:14 +010090 ktime_t resolution;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080091 ktime_t (*get_time)(void);
Thomas Gleixner92127c72006-03-26 01:38:05 -080092 ktime_t (*get_softirq_time)(void);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080093 struct hrtimer *curr_timer;
Thomas Gleixner92127c72006-03-26 01:38:05 -080094 ktime_t softirq_time;
Ingo Molnar54365522006-07-03 00:25:11 -070095 struct lock_class_key lock_key;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080096};
97
Thomas Gleixnerbecf8b52006-01-09 20:52:38 -080098/*
99 * clock_was_set() is a NOP for non- high-resolution systems. The
100 * time-sorted order guarantees that a timer does not expire early and
101 * is expired in the next softirq when the clock was advanced.
102 */
103#define clock_was_set() do { } while (0)
104
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800105/* Exported timer functions: */
106
107/* Initialize timers: */
George Anzinger7978672c2006-02-01 03:05:11 -0800108extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
109 enum hrtimer_mode mode);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800110
111/* Basic timer operations: */
112extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
113 const enum hrtimer_mode mode);
114extern int hrtimer_cancel(struct hrtimer *timer);
115extern int hrtimer_try_to_cancel(struct hrtimer *timer);
116
117#define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS)
118
119/* Query timers: */
120extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
121extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
122
Tony Lindgren69239742006-03-06 15:42:45 -0800123#ifdef CONFIG_NO_IDLE_HZ
124extern ktime_t hrtimer_get_next_event(void);
125#endif
126
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800127static inline int hrtimer_active(const struct hrtimer *timer)
128{
David Woodhouseed198cb2006-04-22 02:38:50 +0100129 return rb_parent(&timer->node) != &timer->node;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800130}
131
132/* Forward a hrtimer so it expires after now: */
Roman Zippel44f21472006-03-26 01:38:06 -0800133extern unsigned long
134hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800135
Thomas Gleixner10c94ec2006-01-09 20:52:35 -0800136/* Precise sleep: */
137extern long hrtimer_nanosleep(struct timespec *rqtp,
138 struct timespec __user *rmtp,
139 const enum hrtimer_mode mode,
140 const clockid_t clockid);
Toyo Abe1711ef32006-09-29 02:00:28 -0700141extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
Thomas Gleixner10c94ec2006-01-09 20:52:35 -0800142
Thomas Gleixner00362e32006-03-31 02:31:17 -0800143extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
144 struct task_struct *tsk);
145
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800146/* Soft interrupt function to run the hrtimer queues: */
147extern void hrtimer_run_queues(void);
148
149/* Bootup initialization: */
150extern void __init hrtimers_init(void);
151
152#endif