![Randy Dunlap](/assets/img/avatar_default.png)
Fix kernel-doc warnings in 2.6.20-git15 (lib/, mm/, kernel/, include/). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
364 lines
10 KiB
C
364 lines
10 KiB
C
/*
|
|
* 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>
|
|
|
|
struct hrtimer_clock_base;
|
|
struct hrtimer_cpu_base;
|
|
|
|
/*
|
|
* Mode arguments of xxx_hrtimer functions:
|
|
*/
|
|
enum hrtimer_mode {
|
|
HRTIMER_MODE_ABS, /* Time value is absolute */
|
|
HRTIMER_MODE_REL, /* Time value is relative to now */
|
|
};
|
|
|
|
/*
|
|
* Return values for the callback function
|
|
*/
|
|
enum hrtimer_restart {
|
|
HRTIMER_NORESTART, /* Timer is not restarted */
|
|
HRTIMER_RESTART, /* Timer must be restarted */
|
|
};
|
|
|
|
/*
|
|
* hrtimer callback modes:
|
|
*
|
|
* HRTIMER_CB_SOFTIRQ: Callback must run in softirq context
|
|
* HRTIMER_CB_IRQSAFE: Callback may run in hardirq context
|
|
* HRTIMER_CB_IRQSAFE_NO_RESTART: Callback may run in hardirq context and
|
|
* does not restart the timer
|
|
* HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: Callback must run in softirq context
|
|
* Special mode for tick emultation
|
|
*/
|
|
enum hrtimer_cb_mode {
|
|
HRTIMER_CB_SOFTIRQ,
|
|
HRTIMER_CB_IRQSAFE,
|
|
HRTIMER_CB_IRQSAFE_NO_RESTART,
|
|
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,
|
|
};
|
|
|
|
/*
|
|
* Values to track state of the timer
|
|
*
|
|
* Possible states:
|
|
*
|
|
* 0x00 inactive
|
|
* 0x01 enqueued into rbtree
|
|
* 0x02 callback function running
|
|
* 0x04 callback pending (high resolution mode)
|
|
*
|
|
* Special case:
|
|
* 0x03 callback function running and enqueued
|
|
* (was requeued on another CPU)
|
|
* The "callback function running and enqueued" status is only possible on
|
|
* SMP. It happens for example when a posix timer expired and the callback
|
|
* queued a signal. Between dropping the lock which protects the posix timer
|
|
* and reacquiring the base lock of the hrtimer, another CPU can deliver the
|
|
* signal and rearm the timer. We have to preserve the callback running state,
|
|
* as otherwise the timer could be removed before the softirq code finishes the
|
|
* the handling of the timer.
|
|
*
|
|
* The HRTIMER_STATE_ENQUEUE bit is always or'ed to the current state to
|
|
* preserve the HRTIMER_STATE_CALLBACK bit in the above scenario.
|
|
*
|
|
* All state transitions are protected by cpu_base->lock.
|
|
*/
|
|
#define HRTIMER_STATE_INACTIVE 0x00
|
|
#define HRTIMER_STATE_ENQUEUED 0x01
|
|
#define HRTIMER_STATE_CALLBACK 0x02
|
|
#define HRTIMER_STATE_PENDING 0x04
|
|
|
|
/**
|
|
* 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.
|
|
* @function: timer expiry callback function
|
|
* @base: pointer to the timer base (per cpu and per clock)
|
|
* @state: state information (See bit values above)
|
|
* @cb_mode: high resolution timer feature to select the callback execution
|
|
* mode
|
|
* @cb_entry: list head to enqueue an expired timer into the callback list
|
|
* @start_site: timer statistics field to store the site where the timer
|
|
* was started
|
|
* @start_comm: timer statistics field to store the name of the process which
|
|
* started the timer
|
|
* @start_pid: timer statistics field to store the pid of the task which
|
|
* started the timer
|
|
*
|
|
* The hrtimer structure must be initialized by hrtimer_init()
|
|
*/
|
|
struct hrtimer {
|
|
struct rb_node node;
|
|
ktime_t expires;
|
|
enum hrtimer_restart (*function)(struct hrtimer *);
|
|
struct hrtimer_clock_base *base;
|
|
unsigned long state;
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
enum hrtimer_cb_mode cb_mode;
|
|
struct list_head cb_entry;
|
|
#endif
|
|
#ifdef CONFIG_TIMER_STATS
|
|
void *start_site;
|
|
char start_comm[16];
|
|
int start_pid;
|
|
#endif
|
|
};
|
|
|
|
/**
|
|
* struct hrtimer_sleeper - simple sleeper structure
|
|
* @timer: embedded timer structure
|
|
* @task: task to wake up
|
|
*
|
|
* task is set to NULL, when the timer expires.
|
|
*/
|
|
struct hrtimer_sleeper {
|
|
struct hrtimer timer;
|
|
struct task_struct *task;
|
|
};
|
|
|
|
/**
|
|
* struct hrtimer_base - the timer base for a specific clock
|
|
* @cpu_base: per cpu clock base
|
|
* @index: clock type index for per_cpu support when moving a
|
|
* timer to a base on another cpu.
|
|
* @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
|
|
* @get_softirq_time: function to retrieve the current time from the softirq
|
|
* @softirq_time: the time when running the hrtimer queue in the softirq
|
|
* @cb_pending: list of timers where the callback is pending
|
|
* @offset: offset of this clock to the monotonic base
|
|
* @reprogram: function to reprogram the timer event
|
|
*/
|
|
struct hrtimer_clock_base {
|
|
struct hrtimer_cpu_base *cpu_base;
|
|
clockid_t index;
|
|
struct rb_root active;
|
|
struct rb_node *first;
|
|
ktime_t resolution;
|
|
ktime_t (*get_time)(void);
|
|
ktime_t (*get_softirq_time)(void);
|
|
ktime_t softirq_time;
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
ktime_t offset;
|
|
int (*reprogram)(struct hrtimer *t,
|
|
struct hrtimer_clock_base *b,
|
|
ktime_t n);
|
|
#endif
|
|
};
|
|
|
|
#define HRTIMER_MAX_CLOCK_BASES 2
|
|
|
|
/*
|
|
* struct hrtimer_cpu_base - the per cpu clock bases
|
|
* @lock: lock protecting the base and associated clock bases
|
|
* and timers
|
|
* @lock_key: the lock_class_key for use with lockdep
|
|
* @clock_base: array of clock bases for this cpu
|
|
* @curr_timer: the timer which is executing a callback right now
|
|
* @expires_next: absolute time of the next event which was scheduled
|
|
* via clock_set_next_event()
|
|
* @hres_active: State of high resolution mode
|
|
* @check_clocks: Indictator, when set evaluate time source and clock
|
|
* event devices whether high resolution mode can be
|
|
* activated.
|
|
* @cb_pending: Expired timers are moved from the rbtree to this
|
|
* list in the timer interrupt. The list is processed
|
|
* in the softirq.
|
|
* @nr_events: Total number of timer interrupt events
|
|
*/
|
|
struct hrtimer_cpu_base {
|
|
spinlock_t lock;
|
|
struct lock_class_key lock_key;
|
|
struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
ktime_t expires_next;
|
|
int hres_active;
|
|
struct list_head cb_pending;
|
|
unsigned long nr_events;
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
|
struct clock_event_device;
|
|
|
|
extern void clock_was_set(void);
|
|
extern void hrtimer_interrupt(struct clock_event_device *dev);
|
|
|
|
/*
|
|
* In high resolution mode the time reference must be read accurate
|
|
*/
|
|
static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
|
|
{
|
|
return timer->base->get_time();
|
|
}
|
|
|
|
/*
|
|
* The resolution of the clocks. The resolution value is returned in
|
|
* the clock_getres() system call to give application programmers an
|
|
* idea of the (in)accuracy of timers. Timer values are rounded up to
|
|
* this resolution values.
|
|
*/
|
|
# define KTIME_HIGH_RES (ktime_t) { .tv64 = 1 }
|
|
# define KTIME_MONOTONIC_RES KTIME_HIGH_RES
|
|
|
|
#else
|
|
|
|
# define KTIME_MONOTONIC_RES KTIME_LOW_RES
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static inline void clock_was_set(void) { }
|
|
|
|
/*
|
|
* In non high resolution mode the time reference is taken from
|
|
* the base softirq time variable.
|
|
*/
|
|
static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
|
|
{
|
|
return timer->base->softirq_time;
|
|
}
|
|
|
|
#endif
|
|
|
|
extern ktime_t ktime_get(void);
|
|
extern ktime_t ktime_get_real(void);
|
|
|
|
/* Exported timer functions: */
|
|
|
|
/* Initialize timers: */
|
|
extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
|
|
enum hrtimer_mode mode);
|
|
|
|
/* 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);
|
|
|
|
static inline int hrtimer_restart(struct hrtimer *timer)
|
|
{
|
|
return hrtimer_start(timer, timer->expires, HRTIMER_MODE_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);
|
|
|
|
extern ktime_t hrtimer_get_next_event(void);
|
|
|
|
/*
|
|
* A timer is active, when it is enqueued into the rbtree or the callback
|
|
* function is running.
|
|
*/
|
|
static inline int hrtimer_active(const struct hrtimer *timer)
|
|
{
|
|
return timer->state != HRTIMER_STATE_INACTIVE;
|
|
}
|
|
|
|
/*
|
|
* Helper function to check, whether the timer is on one of the queues
|
|
*/
|
|
static inline int hrtimer_is_queued(struct hrtimer *timer)
|
|
{
|
|
return timer->state &
|
|
(HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING);
|
|
}
|
|
|
|
/* Forward a hrtimer so it expires after now: */
|
|
extern unsigned long
|
|
hrtimer_forward(struct hrtimer *timer, ktime_t now, 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);
|
|
extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
|
|
|
|
extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
|
|
struct task_struct *tsk);
|
|
|
|
/* Soft interrupt function to run the hrtimer queues: */
|
|
extern void hrtimer_run_queues(void);
|
|
|
|
/* Bootup initialization: */
|
|
extern void __init hrtimers_init(void);
|
|
|
|
#if BITS_PER_LONG < 64
|
|
extern unsigned long ktime_divns(const ktime_t kt, s64 div);
|
|
#else /* BITS_PER_LONG < 64 */
|
|
# define ktime_divns(kt, div) (unsigned long)((kt).tv64 / (div))
|
|
#endif
|
|
|
|
/* Show pending timers: */
|
|
extern void sysrq_timer_list_show(void);
|
|
|
|
/*
|
|
* Timer-statistics info:
|
|
*/
|
|
#ifdef CONFIG_TIMER_STATS
|
|
|
|
extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
|
|
void *timerf, char * comm);
|
|
|
|
static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
|
|
{
|
|
timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
|
|
timer->function, timer->start_comm);
|
|
}
|
|
|
|
extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,
|
|
void *addr);
|
|
|
|
static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
|
|
{
|
|
__timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
|
|
}
|
|
|
|
static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
|
|
{
|
|
timer->start_site = NULL;
|
|
}
|
|
#else
|
|
static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
|
|
{
|
|
}
|
|
|
|
static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
|
|
{
|
|
}
|
|
|
|
static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#endif
|