include/linux/timer.h

   1 #ifndef _LINUX_TIMER_H
   2 #define _LINUX_TIMER_H
   3
   4 #include <linux/config.h>
   5 #include <linux/list.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         spinlock_t lock;
  16         unsigned long magic;
  17
  18         void (*function)(unsigned long);
  19         unsigned long data;
  20
  21         struct tvec_t_base_s *base;
  22 };
  23
  24 #define TIMER_MAGIC     0x4b87ad6e
  25
  26 #define TIMER_INITIALIZER(_function, _expires, _data) {         \
  27                 .function = (_function),                        \
  28                 .expires = (_expires),                          \
  29                 .data = (_data),                                \
  30                 .base = NULL,                                   \
  31                 .magic = TIMER_MAGIC,                           \
  32                 .lock = SPIN_LOCK_UNLOCKED,                     \
  33         }
  34
  35 /***
  36  * init_timer - initialize a timer.
  37  * @timer: the timer to be initialized
  38  *
  39  * init_timer() must be done to a timer prior calling *any* of the
  40  * other timer functions.
  41  */
  42 static inline void init_timer(struct timer_list * timer)
  43 {
  44         timer->base = NULL;
  45         timer->magic = TIMER_MAGIC;
  46         spin_lock_init(&timer->lock);
  47 }
  48
  49 /***
  50  * timer_pending - is a timer pending?
  51  * @timer: the timer in question
  52  *
  53  * timer_pending will tell whether a given timer is currently pending,
  54  * or not. Callers must ensure serialization wrt. other operations done
  55  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
  56  *
  57  * return value: 1 if the timer is pending, 0 if not.
  58  */
  59 static inline int timer_pending(const struct timer_list * timer)
  60 {
  61         return timer->base != NULL;
  62 }
  63
  64 extern void add_timer_on(struct timer_list *timer, int cpu);
  65 extern int del_timer(struct timer_list * timer);
  66 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
  67 extern int mod_timer(struct timer_list *timer, unsigned long expires);
  68
  69 extern unsigned long next_timer_interrupt(void);
  70
  71 /***
  72  * add_timer - start a timer
  73  * @timer: the timer to be added
  74  *
  75  * The kernel will do a ->function(->data) callback from the
  76  * timer interrupt at the ->expired point in the future. The
  77  * current time is 'jiffies'.
  78  *
  79  * The timer's ->expired, ->function (and if the handler uses it, ->data)
  80  * fields must be set prior calling this function.
  81  *
  82  * Timers with an ->expired field in the past will be executed in the next
  83  * timer tick.
  84  */
  85 static inline void add_timer(struct timer_list * timer)
  86 {
  87         __mod_timer(timer, timer->expires);
  88 }
  89
  90 #ifdef CONFIG_SMP
  91   extern int del_timer_sync(struct timer_list *timer);
  92   extern int del_singleshot_timer_sync(struct timer_list *timer);
  93 #else
  94 # define del_timer_sync(t) del_timer(t)
  95 # define del_singleshot_timer_sync(t) del_timer(t)
  96 #endif
  97
  98 extern void init_timers(void);
  99 extern void run_local_timers(void);
 100 extern void it_real_fn(unsigned long);
 101
 102 #endif