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
   9 struct tvec_base;
  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_base *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_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
  40 void init_timer(struct timer_list *timer);
  41 void init_timer_deferrable(struct timer_list *timer);
  42
  43 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  44 extern void init_timer_on_stack(struct timer_list *timer);
  45 extern void destroy_timer_on_stack(struct timer_list *timer);
  46 #else
  47 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
  48 static inline void init_timer_on_stack(struct timer_list *timer)
  49 {
  50         init_timer(timer);
  51 }
  52 #endif
  53
  54 static 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
  63 static 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  */
  82 static inline int timer_pending(const struct timer_list * timer)
  83 {
  84         return timer->entry.next != NULL;
  85 }
  86
  87 extern void add_timer_on(struct timer_list *timer, int cpu);
  88 extern int del_timer(struct timer_list * timer);
  89 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
  90 extern 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  */
 102 extern 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  */
 108 extern 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
 117 extern void init_timer_stats(void);
 118
 119 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 120                                      void *timerf, char *comm,
 121                                      unsigned int timer_flag);
 122
 123 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 124                                                void *addr);
 125
 126 static 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
 131 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 132 {
 133         timer->start_site = NULL;
 134 }
 135 #else
 136 static inline void init_timer_stats(void)
 137 {
 138 }
 139
 140 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 141 {
 142 }
 143
 144 static 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  */
 163 static 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
 179 extern void init_timers(void);
 180 extern void run_local_timers(void);
 181 struct hrtimer;
 182 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 183
 184 unsigned long __round_jiffies(unsigned long j, int cpu);
 185 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 186 unsigned long round_jiffies(unsigned long j);
 187 unsigned long round_jiffies_relative(unsigned long j);
 188
 189 #endif