2 * include/linux/hrtimer.h
4 * hrtimers - High-resolution kernel timers
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
9 * data type definitions, declarations, prototypes
11 * Started by: Thomas Gleixner and Ingo Molnar
13 * For licencing details see kernel-base/COPYING
15 #ifndef _LINUX_HRTIMER_H
16 #define _LINUX_HRTIMER_H
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>
25 * Mode arguments of xxx_hrtimer functions:
28 HRTIMER_ABS, /* Time value is absolute */
29 HRTIMER_REL, /* Time value is relative to now */
32 enum hrtimer_restart {
37 #define HRTIMER_INACTIVE ((void *)1UL)
42 * struct hrtimer - the basic hrtimer structure
44 * @node: red black tree node for time ordered insertion
45 * @expires: the absolute expiry time in the hrtimers internal
46 * representation. The time is related to the clock on
47 * which the timer is based.
48 * @state: state of the timer
49 * @function: timer expiry callback function
50 * @data: argument for the callback function
51 * @base: pointer to the timer base (per cpu and per clock)
53 * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
58 int (*function)(void *);
60 struct hrtimer_base *base;
64 * struct hrtimer_base - the timer base for a specific clock
66 * @index: clock type index for per_cpu support when moving a timer
67 * to a base on another cpu.
68 * @lock: lock protecting the base and associated timers
69 * @active: red black tree root node for the active timers
70 * @first: pointer to the timer node which expires first
71 * @resolution: the resolution of the clock, in nanoseconds
72 * @get_time: function to retrieve the current time of the clock
73 * @get_sofirq_time: function to retrieve the current time from the softirq
74 * @curr_timer: the timer which is executing a callback right now
75 * @softirq_time: the time when running the hrtimer queue in the softirq
80 struct rb_root active;
81 struct rb_node *first;
83 ktime_t (*get_time)(void);
84 ktime_t (*get_softirq_time)(void);
85 struct hrtimer *curr_timer;
90 * clock_was_set() is a NOP for non- high-resolution systems. The
91 * time-sorted order guarantees that a timer does not expire early and
92 * is expired in the next softirq when the clock was advanced.
94 #define clock_was_set() do { } while (0)
96 /* Exported timer functions: */
98 /* Initialize timers: */
99 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
100 enum hrtimer_mode mode);
102 /* Basic timer operations: */
103 extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
104 const enum hrtimer_mode mode);
105 extern int hrtimer_cancel(struct hrtimer *timer);
106 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
108 #define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS)
111 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
112 extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
114 #ifdef CONFIG_NO_IDLE_HZ
115 extern ktime_t hrtimer_get_next_event(void);
118 static inline int hrtimer_active(const struct hrtimer *timer)
120 return timer->node.rb_parent != HRTIMER_INACTIVE;
123 /* Forward a hrtimer so it expires after now: */
125 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
128 extern long hrtimer_nanosleep(struct timespec *rqtp,
129 struct timespec __user *rmtp,
130 const enum hrtimer_mode mode,
131 const clockid_t clockid);
133 /* Soft interrupt function to run the hrtimer queues: */
134 extern void hrtimer_run_queues(void);
136 /* Bootup initialization: */
137 extern void __init hrtimers_init(void);