/*
* 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,
};
/*
* Timer states:
*/
enum hrtimer_state {
HRTIMER_INACTIVE, /* Timer is inactive */
HRTIMER_EXPIRED, /* Timer is expired */
HRTIMER_PENDING, /* Timer is pending */
};
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.
* @state: state of the timer
* @function: timer expiry callback function
* @data: argument for the 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;
enum hrtimer_state state;
int (*function)(void *);
void *data;
struct hrtimer_base *base;
};
/**
* 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
* @curr_timer: the timer which is executing a callback right now
*/
struct hrtimer_base {
clockid_t index;
spinlock_t lock;
struct rb_root active;
struct rb_node *first;
unsigned long resolution;
ktime_t (*get_time)(void);
struct hrtimer *curr_timer;
};
/*
* 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, const clockid_t which_clock);
extern void hrtimer_rebase(struct hrtimer *timer, const clockid_t which_clock);
/* 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);
static inline int hrtimer_active(const struct hrtimer *timer)
{
return timer->state == HRTIMER_PENDING;
}
/* Forward a hrtimer so it expires after now: */
extern unsigned long hrtimer_forward(struct hrtimer *timer,
const 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);
/* Soft interrupt function to run the hrtimer queues: */
extern void hrtimer_run_queues(void);
/* Bootup initialization: */
extern void __init hrtimers_init(void);
#endif
