[PATCH] Extend next_timer_interrupt() to use a reference jiffie

[deliverable/linux.git] / include / linux / timer.h

#ifndef _LINUX_TIMER_H
#define _LINUX_TIMER_H

#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>

struct tvec_t_base_s;

struct timer_list {
	struct list_head entry;
	unsigned long expires;

	void (*function)(unsigned long);
	unsigned long data;

	struct tvec_t_base_s *base;
};

extern struct tvec_t_base_s boot_tvec_bases;

#define TIMER_INITIALIZER(_function, _expires, _data) {		\
		.function = (_function),			\
		.expires = (_expires),				\
		.data = (_data),				\
		.base = &boot_tvec_bases,			\
	}

#define DEFINE_TIMER(_name, _function, _expires, _data)		\
	struct timer_list _name =				\
		TIMER_INITIALIZER(_function, _expires, _data)

void fastcall init_timer(struct timer_list * timer);

static inline void setup_timer(struct timer_list * timer,
				void (*function)(unsigned long),
				unsigned long data)
{
	timer->function = function;
	timer->data = data;
	init_timer(timer);
}

/**
 * timer_pending - is a timer pending?
 * @timer: the timer in question
 *
 * timer_pending will tell whether a given timer is currently pending,
 * or not. Callers must ensure serialization wrt. other operations done
 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 *
 * return value: 1 if the timer is pending, 0 if not.
 */
static inline int timer_pending(const struct timer_list * timer)
{
	return timer->entry.next != NULL;
}

extern void add_timer_on(struct timer_list *timer, int cpu);
extern int del_timer(struct timer_list * timer);
extern int __mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer(struct timer_list *timer, unsigned long expires);

/*
 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 * locks the timer base:
 */
extern unsigned long next_timer_interrupt(void);
/*
 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 * locks the timer base and does the comparison against the given
 * jiffie.
 */
extern unsigned long get_next_timer_interrupt(unsigned long now);

/**
 * add_timer - start a timer
 * @timer: the timer to be added
 *
 * The kernel will do a ->function(->data) callback from the
 * timer interrupt at the ->expires point in the future. The
 * current time is 'jiffies'.
 *
 * The timer's ->expires, ->function (and if the handler uses it, ->data)
 * fields must be set prior calling this function.
 *
 * Timers with an ->expires field in the past will be executed in the next
 * timer tick.
 */
static inline void add_timer(struct timer_list *timer)
{
	BUG_ON(timer_pending(timer));
	__mod_timer(timer, timer->expires);
}

#ifdef CONFIG_SMP
  extern int try_to_del_timer_sync(struct timer_list *timer);
  extern int del_timer_sync(struct timer_list *timer);
#else
# define try_to_del_timer_sync(t)	del_timer(t)
# define del_timer_sync(t)		del_timer(t)
#endif

#define del_singleshot_timer_sync(t) del_timer_sync(t)

extern void init_timers(void);
extern void run_local_timers(void);
struct hrtimer;
extern int it_real_fn(struct hrtimer *);

unsigned long __round_jiffies(unsigned long j, int cpu);
unsigned long __round_jiffies_relative(unsigned long j, int cpu);
unsigned long round_jiffies(unsigned long j);
unsigned long round_jiffies_relative(unsigned long j);


#endif