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 void fastcall init_timer_deferrable(struct timer_list *timer);
  41
  42 static inline void setup_timer(struct timer_list * timer,
  43                                 void (*function)(unsigned long),
  44                                 unsigned long data)
  45 {
  46         timer->function = function;
  47         timer->data = data;
  48         init_timer(timer);
  49 }
  50
  51 /**
  52  * timer_pending - is a timer pending?
  53  * @timer: the timer in question
  54  *
  55  * timer_pending will tell whether a given timer is currently pending,
  56  * or not. Callers must ensure serialization wrt. other operations done
  57  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
  58  *
  59  * return value: 1 if the timer is pending, 0 if not.
  60  */
  61 static inline int timer_pending(const struct timer_list * timer)
  62 {
  63         return timer->entry.next != NULL;
  64 }
  65
  66 extern void add_timer_on(struct timer_list *timer, int cpu);
  67 extern int del_timer(struct timer_list * timer);
  68 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
  69 extern int mod_timer(struct timer_list *timer, unsigned long expires);
  70
  71 /*
  72  * The jiffies value which is added to now, when there is no timer
  73  * in the timer wheel:
  74  */
  75 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
  76
  77 /*
  78  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  79  * locks the timer base:
  80  */
  81 extern unsigned long next_timer_interrupt(void);
  82 /*
  83  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  84  * locks the timer base and does the comparison against the given
  85  * jiffie.
  86  */
  87 extern unsigned long get_next_timer_interrupt(unsigned long now);
  88
  89 /*
  90  * Timer-statistics info:
  91  */
  92 #ifdef CONFIG_TIMER_STATS
  93
  94 extern void init_timer_stats(void);
  95
  96 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
  97                                      void *timerf, char * comm);
  98
  99 static inline void timer_stats_account_timer(struct timer_list *timer)
 100 {
 101         timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
 102                                  timer->function, timer->start_comm);
 103 }
 104
 105 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 106                                                void *addr);
 107
 108 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 109 {
 110         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 111 }
 112
 113 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 114 {
 115         timer->start_site = NULL;
 116 }
 117 #else
 118 static inline void init_timer_stats(void)
 119 {
 120 }
 121
 122 static inline void timer_stats_account_timer(struct timer_list *timer)
 123 {
 124 }
 125
 126 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 127 {
 128 }
 129
 130 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 131 {
 132 }
 133 #endif
 134
 135 extern void delayed_work_timer_fn(unsigned long __data);
 136
 137 /**
 138  * add_timer - start a timer
 139  * @timer: the timer to be added
 140  *
 141  * The kernel will do a ->function(->data) callback from the
 142  * timer interrupt at the ->expires point in the future. The
 143  * current time is 'jiffies'.
 144  *
 145  * The timer's ->expires, ->function (and if the handler uses it, ->data)
 146  * fields must be set prior calling this function.
 147  *
 148  * Timers with an ->expires field in the past will be executed in the next
 149  * timer tick.
 150  */
 151 static inline void add_timer(struct timer_list *timer)
 152 {
 153         BUG_ON(timer_pending(timer));
 154         __mod_timer(timer, timer->expires);
 155 }
 156
 157 #ifdef CONFIG_SMP
 158   extern int try_to_del_timer_sync(struct timer_list *timer);
 159   extern int del_timer_sync(struct timer_list *timer);
 160 #else
 161 # define try_to_del_timer_sync(t)       del_timer(t)
 162 # define del_timer_sync(t)              del_timer(t)
 163 #endif
 164
 165 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 166
 167 extern void init_timers(void);
 168 extern void run_local_timers(void);
 169 struct hrtimer;
 170 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 171
 172 unsigned long __round_jiffies(unsigned long j, int cpu);
 173 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 174 unsigned long round_jiffies(unsigned long j);
 175 unsigned long round_jiffies_relative(unsigned long j);
 176
 177
 178 #endif