LXR linux/include/linux/timer.h

   1#ifndef _LINUX_TIMER_H
   2#define _LINUX_TIMER_H
   3
   4#include <linux/list.h>
   5#include <linux/ktime.h>
   6#include <linux/stddef.h>
   7#include <linux/debugobjects.h>
   8
   9struct tvec_base;
  10
  11struct timer_list {
  12        struct list_head entry;
  13        unsigned long expires;
  14
  15        void (*function)(unsigned long);
  16        unsigned long data;
  17
  18        struct tvec_base *base;
  19#ifdef CONFIG_TIMER_STATS
  20        void *start_site;
  21        char start_comm[16];
  22        int start_pid;
  23#endif
  24};
  25
  26extern struct tvec_base boot_tvec_bases;
  27
  28#define TIMER_INITIALIZER(_function, _expires, _data) {         \
  29                .entry = { .prev = TIMER_ENTRY_STATIC },        \
  30                .function = (_function),                        \
  31                .expires = (_expires),                          \
  32                .data = (_data),                                \
  33                .base = &boot_tvec_bases,                       \
  34        }
  35
  36#define DEFINE_TIMER(_name, _function, _expires, _data)         \
  37        struct timer_list _name =                               \
  38                TIMER_INITIALIZER(_function, _expires, _data)
  39
  40void init_timer(struct timer_list *timer);
  41void init_timer_deferrable(struct timer_list *timer);
  42
  43#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  44extern void init_timer_on_stack(struct timer_list *timer);
  45extern void destroy_timer_on_stack(struct timer_list *timer);
  46#else
  47static inline void destroy_timer_on_stack(struct timer_list *timer) { }
  48static inline void init_timer_on_stack(struct timer_list *timer)
  49{
  50        init_timer(timer);
  51}
  52#endif
  53
  54static inline void setup_timer(struct timer_list * timer,
  55                                void (*function)(unsigned long),
  56                                unsigned long data)
  57{
  58        timer->function = function;
  59        timer->data = data;
  60        init_timer(timer);
  61}
  62
  63static inline void setup_timer_on_stack(struct timer_list *timer,
  64                                        void (*function)(unsigned long),
  65                                        unsigned long data)
  66{
  67        timer->function = function;
  68        timer->data = data;
  69        init_timer_on_stack(timer);
  70}
  71
  72/**
  73 * timer_pending - is a timer pending?
  74 * @timer: the timer in question
  75 *
  76 * timer_pending will tell whether a given timer is currently pending,
  77 * or not. Callers must ensure serialization wrt. other operations done
  78 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
  79 *
  80 * return value: 1 if the timer is pending, 0 if not.
  81 */
  82static inline int timer_pending(const struct timer_list * timer)
  83{
  84        return timer->entry.next != NULL;
  85}
  86
  87extern void add_timer_on(struct timer_list *timer, int cpu);
  88extern int del_timer(struct timer_list * timer);
  89extern int __mod_timer(struct timer_list *timer, unsigned long expires);
  90extern int mod_timer(struct timer_list *timer, unsigned long expires);
  91
  92/*
  93 * The jiffies value which is added to now, when there is no timer
  94 * in the timer wheel:
  95 */
  96#define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
  97
  98/*
  99 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 100 * locks the timer base:
 101 */
 102extern unsigned long next_timer_interrupt(void);
 103/*
 104 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 105 * locks the timer base and does the comparison against the given
 106 * jiffie.
 107 */
 108extern unsigned long get_next_timer_interrupt(unsigned long now);
 109
 110/*
 111 * Timer-statistics info:
 112 */
 113#ifdef CONFIG_TIMER_STATS
 114
 115#define TIMER_STATS_FLAG_DEFERRABLE     0x1
 116
 117extern void init_timer_stats(void);
 118
 119extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 120                                     void *timerf, char *comm,
 121                                     unsigned int timer_flag);
 122
 123extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 124                                               void *addr);
 125
 126static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 127{
 128        __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 129}
 130
 131static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 132{
 133        timer->start_site = NULL;
 134}
 135#else
 136static inline void init_timer_stats(void)
 137{
 138}
 139
 140static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 141{
 142}
 143
 144static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 145{
 146}
 147#endif
 148
 149/**
 150 * add_timer - start a timer
 151 * @timer: the timer to be added
 152 *
 153 * The kernel will do a ->function(->data) callback from the
 154 * timer interrupt at the ->expires point in the future. The
 155 * current time is 'jiffies'.
 156 *
 157 * The timer's ->expires, ->function (and if the handler uses it, ->data)
 158 * fields must be set prior calling this function.
 159 *
 160 * Timers with an ->expires field in the past will be executed in the next
 161 * timer tick.
 162 */
 163static inline void add_timer(struct timer_list *timer)
 164{
 165        BUG_ON(timer_pending(timer));
 166        __mod_timer(timer, timer->expires);
 167}
 168
 169#ifdef CONFIG_SMP
 170  extern int try_to_del_timer_sync(struct timer_list *timer);
 171  extern int del_timer_sync(struct timer_list *timer);
 172#else
 173# define try_to_del_timer_sync(t)       del_timer(t)
 174# define del_timer_sync(t)              del_timer(t)
 175#endif
 176
 177#define del_singleshot_timer_sync(t) del_timer_sync(t)
 178
 179extern void init_timers(void);
 180extern void run_local_timers(void);
 181struct hrtimer;
 182extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 183
 184unsigned long __round_jiffies(unsigned long j, int cpu);
 185unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 186unsigned long round_jiffies(unsigned long j);
 187unsigned long round_jiffies_relative(unsigned long j);
 188
 189#endif
 190