LXR linux/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#include <linux/stringify.h>
   9
  10struct tvec_base;
  11
  12struct timer_list {
  13        struct list_head entry;
  14        unsigned long expires;
  15
  16        void (*function)(unsigned long);
  17        unsigned long data;
  18
  19        struct tvec_base *base;
  20#ifdef CONFIG_TIMER_STATS
  21        void *start_site;
  22        char start_comm[16];
  23        int start_pid;
  24#endif
  25#ifdef CONFIG_LOCKDEP
  26        struct lockdep_map lockdep_map;
  27#endif
  28};
  29
  30extern struct tvec_base boot_tvec_bases;
  31
  32#ifdef CONFIG_LOCKDEP
  33/*
  34 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
  35 * (second argument) here is required, otherwise it could be initialised to
  36 * the copy of the lockdep_map later! We use the pointer to and the string
  37 * "<file>:<line>" as the key resp. the name of the lockdep_map.
  38 */
  39#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                            \
  40        .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
  41#else
  42#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
  43#endif
  44
  45#define TIMER_INITIALIZER(_function, _expires, _data) {         \
  46                .entry = { .prev = TIMER_ENTRY_STATIC },        \
  47                .function = (_function),                        \
  48                .expires = (_expires),                          \
  49                .data = (_data),                                \
  50                .base = &boot_tvec_bases,                       \
  51                __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  52                        __FILE__ ":" __stringify(__LINE__))     \
  53        }
  54
  55#define DEFINE_TIMER(_name, _function, _expires, _data)         \
  56        struct timer_list _name =                               \
  57                TIMER_INITIALIZER(_function, _expires, _data)
  58
  59void init_timer_key(struct timer_list *timer,
  60                    const char *name,
  61                    struct lock_class_key *key);
  62void init_timer_deferrable_key(struct timer_list *timer,
  63                               const char *name,
  64                               struct lock_class_key *key);
  65
  66#ifdef CONFIG_LOCKDEP
  67#define init_timer(timer)                                               \
  68        do {                                                            \
  69                static struct lock_class_key __key;                     \
  70                init_timer_key((timer), #timer, &__key);                \
  71        } while (0)
  72
  73#define init_timer_deferrable(timer)                                    \
  74        do {                                                            \
  75                static struct lock_class_key __key;                     \
  76                init_timer_deferrable_key((timer), #timer, &__key);     \
  77        } while (0)
  78
  79#define init_timer_on_stack(timer)                                      \
  80        do {                                                            \
  81                static struct lock_class_key __key;                     \
  82                init_timer_on_stack_key((timer), #timer, &__key);       \
  83        } while (0)
  84
  85#define setup_timer(timer, fn, data)                                    \
  86        do {                                                            \
  87                static struct lock_class_key __key;                     \
  88                setup_timer_key((timer), #timer, &__key, (fn), (data));\
  89        } while (0)
  90
  91#define setup_timer_on_stack(timer, fn, data)                           \
  92        do {                                                            \
  93                static struct lock_class_key __key;                     \
  94                setup_timer_on_stack_key((timer), #timer, &__key,       \
  95                                         (fn), (data));                 \
  96        } while (0)
  97#else
  98#define init_timer(timer)\
  99        init_timer_key((timer), NULL, NULL)
 100#define init_timer_deferrable(timer)\
 101        init_timer_deferrable_key((timer), NULL, NULL)
 102#define init_timer_on_stack(timer)\
 103        init_timer_on_stack_key((timer), NULL, NULL)
 104#define setup_timer(timer, fn, data)\
 105        setup_timer_key((timer), NULL, NULL, (fn), (data))
 106#define setup_timer_on_stack(timer, fn, data)\
 107        setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 108#endif
 109
 110#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 111extern void init_timer_on_stack_key(struct timer_list *timer,
 112                                    const char *name,
 113                                    struct lock_class_key *key);
 114extern void destroy_timer_on_stack(struct timer_list *timer);
 115#else
 116static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 117static inline void init_timer_on_stack_key(struct timer_list *timer,
 118                                           const char *name,
 119                                           struct lock_class_key *key)
 120{
 121        init_timer_key(timer, name, key);
 122}
 123#endif
 124
 125static inline void setup_timer_key(struct timer_list * timer,
 126                                const char *name,
 127                                struct lock_class_key *key,
 128                                void (*function)(unsigned long),
 129                                unsigned long data)
 130{
 131        timer->function = function;
 132        timer->data = data;
 133        init_timer_key(timer, name, key);
 134}
 135
 136static inline void setup_timer_on_stack_key(struct timer_list *timer,
 137                                        const char *name,
 138                                        struct lock_class_key *key,
 139                                        void (*function)(unsigned long),
 140                                        unsigned long data)
 141{
 142        timer->function = function;
 143        timer->data = data;
 144        init_timer_on_stack_key(timer, name, key);
 145}
 146
 147/**
 148 * timer_pending - is a timer pending?
 149 * @timer: the timer in question
 150 *
 151 * timer_pending will tell whether a given timer is currently pending,
 152 * or not. Callers must ensure serialization wrt. other operations done
 153 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 154 *
 155 * return value: 1 if the timer is pending, 0 if not.
 156 */
 157static inline int timer_pending(const struct timer_list * timer)
 158{
 159        return timer->entry.next != NULL;
 160}
 161
 162extern void add_timer_on(struct timer_list *timer, int cpu);
 163extern int del_timer(struct timer_list * timer);
 164extern int mod_timer(struct timer_list *timer, unsigned long expires);
 165extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 166extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 167
 168#define TIMER_NOT_PINNED        0
 169#define TIMER_PINNED            1
 170/*
 171 * The jiffies value which is added to now, when there is no timer
 172 * in the timer wheel:
 173 */
 174#define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 175
 176/*
 177 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 178 * locks the timer base and does the comparison against the given
 179 * jiffie.
 180 */
 181extern unsigned long get_next_timer_interrupt(unsigned long now);
 182
 183/*
 184 * Timer-statistics info:
 185 */
 186#ifdef CONFIG_TIMER_STATS
 187
 188extern int timer_stats_active;
 189
 190#define TIMER_STATS_FLAG_DEFERRABLE     0x1
 191
 192extern void init_timer_stats(void);
 193
 194extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 195                                     void *timerf, char *comm,
 196                                     unsigned int timer_flag);
 197
 198extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 199                                               void *addr);
 200
 201static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 202{
 203        if (likely(!timer_stats_active))
 204                return;
 205        __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 206}
 207
 208static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 209{
 210        timer->start_site = NULL;
 211}
 212#else
 213static inline void init_timer_stats(void)
 214{
 215}
 216
 217static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 218{
 219}
 220
 221static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 222{
 223}
 224#endif
 225
 226extern void add_timer(struct timer_list *timer);
 227
 228#ifdef CONFIG_SMP
 229  extern int try_to_del_timer_sync(struct timer_list *timer);
 230  extern int del_timer_sync(struct timer_list *timer);
 231#else
 232# define try_to_del_timer_sync(t)       del_timer(t)
 233# define del_timer_sync(t)              del_timer(t)
 234#endif
 235
 236#define del_singleshot_timer_sync(t) del_timer_sync(t)
 237
 238extern void init_timers(void);
 239extern void run_local_timers(void);
 240struct hrtimer;
 241extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 242
 243unsigned long __round_jiffies(unsigned long j, int cpu);
 244unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 245unsigned long round_jiffies(unsigned long j);
 246unsigned long round_jiffies_relative(unsigned long j);
 247
 248unsigned long __round_jiffies_up(unsigned long j, int cpu);
 249unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 250unsigned long round_jiffies_up(unsigned long j);
 251unsigned long round_jiffies_up_relative(unsigned long j);
 252
 253#endif
 254