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
   8 struct tvec_base;
   9
  10 struct timer_list {
  11         struct list_head entry;
  12         unsigned long expires;
  13
  14         void (*function)(unsigned long);
  15         unsigned long data;
  16
  17         struct tvec_base *base;
  18 #ifdef CONFIG_TIMER_STATS
  19         void *start_site;
  20         char start_comm[16];
  21         int start_pid;
  22 #endif
  23 };
  24
  25 extern struct tvec_base boot_tvec_bases;
  26
  27 #define TIMER_INITIALIZER(_function, _expires, _data) {         \
  28                 .function = (_function),                        \
  29                 .expires = (_expires),                          \
  30                 .data = (_data),                                \
  31                 .base = &boot_tvec_bases,                       \
  32         }
  33
  34 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  35         struct timer_list _name =                               \
  36                 TIMER_INITIALIZER(_function, _expires, _data)
  37
  38 void init_timer(struct timer_list *timer);
  39 void init_timer_deferrable(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  * The jiffies value which is added to now, when there is no timer
  72  * in the timer wheel:
  73  */
  74 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
  75
  76 /*
  77  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  78  * locks the timer base:
  79  */
  80 extern unsigned long next_timer_interrupt(void);
  81 /*
  82  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
  83  * locks the timer base and does the comparison against the given
  84  * jiffie.
  85  */
  86 extern unsigned long get_next_timer_interrupt(unsigned long now);
  87
  88 /*
  89  * Timer-statistics info:
  90  */
  91 #ifdef CONFIG_TIMER_STATS
  92
  93 #define TIMER_STATS_FLAG_DEFERRABLE     0x1
  94
  95 extern void init_timer_stats(void);
  96
  97 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
  98                                      void *timerf, char *comm,
  99                                      unsigned int timer_flag);
 100
 101 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 102                                                void *addr);
 103
 104 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 105 {
 106         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 107 }
 108
 109 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 110 {
 111         timer->start_site = NULL;
 112 }
 113 #else
 114 static inline void init_timer_stats(void)
 115 {
 116 }
 117
 118 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 119 {
 120 }
 121
 122 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 123 {
 124 }
 125 #endif
 126
 127 /**
 128  * add_timer - start a timer
 129  * @timer: the timer to be added
 130  *
 131  * The kernel will do a ->function(->data) callback from the
 132  * timer interrupt at the ->expires point in the future. The
 133  * current time is 'jiffies'.
 134  *
 135  * The timer's ->expires, ->function (and if the handler uses it, ->data)
 136  * fields must be set prior calling this function.
 137  *
 138  * Timers with an ->expires field in the past will be executed in the next
 139  * timer tick.
 140  */
 141 static inline void add_timer(struct timer_list *timer)
 142 {
 143         BUG_ON(timer_pending(timer));
 144         __mod_timer(timer, timer->expires);
 145 }
 146
 147 #ifdef CONFIG_SMP
 148   extern int try_to_del_timer_sync(struct timer_list *timer);
 149   extern int del_timer_sync(struct timer_list *timer);
 150 #else
 151 # define try_to_del_timer_sync(t)       del_timer(t)
 152 # define del_timer_sync(t)              del_timer(t)
 153 #endif
 154
 155 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 156
 157 extern void init_timers(void);
 158 extern void run_local_timers(void);
 159 struct hrtimer;
 160 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 161
 162 unsigned long __round_jiffies(unsigned long j, int cpu);
 163 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 164 unsigned long round_jiffies(unsigned long j);
 165 unsigned long round_jiffies_relative(unsigned long j);
 166
 167
 168 #endif