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/spinlock.h>
   7 #include <linux/stddef.h>
   8
   9 struct tvec_t_base_s;
  10
  11 struct 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_t_base_s *base;
  19 #ifdef CONFIG_TIMER_STATS
  20         void *start_site;
  21         char start_comm[16];
  22         int start_pid;
  23 #endif
  24 };
  25
  26 extern struct tvec_t_base_s boot_tvec_bases;
  27
  28 #define TIMER_INITIALIZER(_function, _expires, _data) {         \
  29                 .function = (_function),                        \
  30                 .expires = (_expires),                          \
  31                 .data = (_data),                                \
  32                 .base = &boot_tvec_bases,                       \
  33         }
  34
  35 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  36         struct timer_list _name =                               \
  37                 TIMER_INITIALIZER(_function, _expires, _data)
  38
  39 void fastcall init_timer(struct timer_list * timer);
  40
  41 static inline void setup_timer(struct timer_list * timer,
  42                                 void (*function)(unsigned long),
  43                                 unsigned long data)
  44 {
  45         timer->function = function;
  46         timer->data = data;
  47         init_timer(timer);
  48 }
  49
  50 /**
  51  * timer_pending - is a timer pending?
  52  * @timer: the timer in question
  53  *
  54  * timer_pending will tell whether a given timer is currently pending,
  55  * or not. Callers must ensure serialization wrt. other operations done
  56  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
  57  *
  58  * return value: 1 if the timer is pending, 0 if not.
  59  */
  60 static inline int timer_pending(const struct timer_list * timer)
  61 {
  62         return timer->entry.next != NULL;
  63 }
  64
  65 extern void add_timer_on(struct timer_list *timer, int cpu);
  66 extern int del_timer(struct timer_list * timer);
  67 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
  68 extern int mod_timer(struct timer_list *timer, unsigned long expires);
  69
  70 /*
  71  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  72  * locks the timer base:
  73  */
  74 extern unsigned long next_timer_interrupt(void);
  75 /*
  76  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  77  * locks the timer base and does the comparison against the given
  78  * jiffie.
  79  */
  80 extern unsigned long get_next_timer_interrupt(unsigned long now);
  81
  82 /*
  83  * Timer-statistics info:
  84  */
  85 #ifdef CONFIG_TIMER_STATS
  86
  87 extern void init_timer_stats(void);
  88
  89 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
  90                                      void *timerf, char * comm);
  91
  92 static inline void timer_stats_account_timer(struct timer_list *timer)
  93 {
  94         timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
  95                                  timer->function, timer->start_comm);
  96 }
  97
  98 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
  99                                                void *addr);
 100
 101 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 102 {
 103         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 104 }
 105
 106 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 107 {
 108         timer->start_site = NULL;
 109 }
 110 #else
 111 static inline void init_timer_stats(void)
 112 {
 113 }
 114
 115 static inline void timer_stats_account_timer(struct timer_list *timer)
 116 {
 117 }
 118
 119 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 120 {
 121 }
 122
 123 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 124 {
 125 }
 126 #endif
 127
 128 extern void delayed_work_timer_fn(unsigned long __data);
 129
 130 /**
 131  * add_timer - start a timer
 132  * @timer: the timer to be added
 133  *
 134  * The kernel will do a ->function(->data) callback from the
 135  * timer interrupt at the ->expires point in the future. The
 136  * current time is 'jiffies'.
 137  *
 138  * The timer's ->expires, ->function (and if the handler uses it, ->data)
 139  * fields must be set prior calling this function.
 140  *
 141  * Timers with an ->expires field in the past will be executed in the next
 142  * timer tick.
 143  */
 144 static inline void add_timer(struct timer_list *timer)
 145 {
 146         BUG_ON(timer_pending(timer));
 147         __mod_timer(timer, timer->expires);
 148 }
 149
 150 #ifdef CONFIG_SMP
 151   extern int try_to_del_timer_sync(struct timer_list *timer);
 152   extern int del_timer_sync(struct timer_list *timer);
 153 #else
 154 # define try_to_del_timer_sync(t)       del_timer(t)
 155 # define del_timer_sync(t)              del_timer(t)
 156 #endif
 157
 158 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 159
 160 extern void init_timers(void);
 161 extern void run_local_timers(void);
 162 struct hrtimer;
 163 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 164
 165 unsigned long __round_jiffies(unsigned long j, int cpu);
 166 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 167 unsigned long round_jiffies(unsigned long j);
 168 unsigned long round_jiffies_relative(unsigned long j);
 169
 170
 171 #endif