c9db4fa115
Roman Zippel pointed out that the missing lower limit of intervals leads to an accounting error in the overrun count. Enforce the lower limit of intervals to resolution in the timer forwarding code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
140 lines
3.8 KiB
C
140 lines
3.8 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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/*
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* Timer states:
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*/
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enum hrtimer_state {
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HRTIMER_INACTIVE, /* Timer is inactive */
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HRTIMER_EXPIRED, /* Timer is expired */
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HRTIMER_PENDING, /* Timer is pending */
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};
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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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*
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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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* @state: state of the timer
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* @function: timer expiry callback function
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* @data: argument for the 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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enum hrtimer_state state;
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int (*function)(void *);
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void *data;
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struct hrtimer_base *base;
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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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*
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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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* @curr_timer: the timer which is executing a callback right now
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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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struct hrtimer *curr_timer;
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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, const clockid_t which_clock);
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extern void hrtimer_rebase(struct hrtimer *timer, const clockid_t which_clock);
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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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static inline int hrtimer_active(const struct hrtimer *timer)
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{
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return timer->state == HRTIMER_PENDING;
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}
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/* Forward a hrtimer so it expires after now: */
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extern unsigned long hrtimer_forward(struct hrtimer *timer, 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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/* 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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