linux/include/linux/timer.h
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   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        /*
  14         * All fields that change during normal runtime grouped to the
  15         * same cacheline
  16         */
  17        struct list_head entry;
  18        unsigned long expires;
  19        struct tvec_base *base;
  20
  21        void (*function)(unsigned long);
  22        unsigned long data;
  23
  24        int slack;
  25
  26#ifdef CONFIG_TIMER_STATS
  27        int start_pid;
  28        void *start_site;
  29        char start_comm[16];
  30#endif
  31#ifdef CONFIG_LOCKDEP
  32        struct lockdep_map lockdep_map;
  33#endif
  34};
  35
  36extern struct tvec_base boot_tvec_bases;
  37
  38#ifdef CONFIG_LOCKDEP
  39/*
  40 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
  41 * (second argument) here is required, otherwise it could be initialised to
  42 * the copy of the lockdep_map later! We use the pointer to and the string
  43 * "<file>:<line>" as the key resp. the name of the lockdep_map.
  44 */
  45#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                            \
  46        .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
  47#else
  48#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
  49#endif
  50
  51/*
  52 * Note that all tvec_bases are 2 byte aligned and lower bit of
  53 * base in timer_list is guaranteed to be zero. Use the LSB to
  54 * indicate whether the timer is deferrable.
  55 *
  56 * A deferrable timer will work normally when the system is busy, but
  57 * will not cause a CPU to come out of idle just to service it; instead,
  58 * the timer will be serviced when the CPU eventually wakes up with a
  59 * subsequent non-deferrable timer.
  60 */
  61#define TBASE_DEFERRABLE_FLAG           (0x1)
  62
  63#define TIMER_INITIALIZER(_function, _expires, _data) {         \
  64                .entry = { .prev = TIMER_ENTRY_STATIC },        \
  65                .function = (_function),                        \
  66                .expires = (_expires),                          \
  67                .data = (_data),                                \
  68                .base = &boot_tvec_bases,                       \
  69                .slack = -1,                                    \
  70                __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  71                        __FILE__ ":" __stringify(__LINE__))     \
  72        }
  73
  74#define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *)          \
  75                  ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG))
  76
  77#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\
  78                .entry = { .prev = TIMER_ENTRY_STATIC },        \
  79                .function = (_function),                        \
  80                .expires = (_expires),                          \
  81                .data = (_data),                                \
  82                .base = TBASE_MAKE_DEFERRED(&boot_tvec_bases),  \
  83                __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  84                        __FILE__ ":" __stringify(__LINE__))     \
  85        }
  86
  87#define DEFINE_TIMER(_name, _function, _expires, _data)         \
  88        struct timer_list _name =                               \
  89                TIMER_INITIALIZER(_function, _expires, _data)
  90
  91void init_timer_key(struct timer_list *timer,
  92                    const char *name,
  93                    struct lock_class_key *key);
  94void init_timer_deferrable_key(struct timer_list *timer,
  95                               const char *name,
  96                               struct lock_class_key *key);
  97
  98#ifdef CONFIG_LOCKDEP
  99#define init_timer(timer)                                               \
 100        do {                                                            \
 101                static struct lock_class_key __key;                     \
 102                init_timer_key((timer), #timer, &__key);                \
 103        } while (0)
 104
 105#define init_timer_deferrable(timer)                                    \
 106        do {                                                            \
 107                static struct lock_class_key __key;                     \
 108                init_timer_deferrable_key((timer), #timer, &__key);     \
 109        } while (0)
 110
 111#define init_timer_on_stack(timer)                                      \
 112        do {                                                            \
 113                static struct lock_class_key __key;                     \
 114                init_timer_on_stack_key((timer), #timer, &__key);       \
 115        } while (0)
 116
 117#define setup_timer(timer, fn, data)                                    \
 118        do {                                                            \
 119                static struct lock_class_key __key;                     \
 120                setup_timer_key((timer), #timer, &__key, (fn), (data));\
 121        } while (0)
 122
 123#define setup_timer_on_stack(timer, fn, data)                           \
 124        do {                                                            \
 125                static struct lock_class_key __key;                     \
 126                setup_timer_on_stack_key((timer), #timer, &__key,       \
 127                                         (fn), (data));                 \
 128        } while (0)
 129#define setup_deferrable_timer_on_stack(timer, fn, data)                \
 130        do {                                                            \
 131                static struct lock_class_key __key;                     \
 132                setup_deferrable_timer_on_stack_key((timer), #timer,    \
 133                                                    &__key, (fn),       \
 134                                                    (data));            \
 135        } while (0)
 136#else
 137#define init_timer(timer)\
 138        init_timer_key((timer), NULL, NULL)
 139#define init_timer_deferrable(timer)\
 140        init_timer_deferrable_key((timer), NULL, NULL)
 141#define init_timer_on_stack(timer)\
 142        init_timer_on_stack_key((timer), NULL, NULL)
 143#define setup_timer(timer, fn, data)\
 144        setup_timer_key((timer), NULL, NULL, (fn), (data))
 145#define setup_timer_on_stack(timer, fn, data)\
 146        setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 147#define setup_deferrable_timer_on_stack(timer, fn, data)\
 148        setup_deferrable_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 149#endif
 150
 151#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 152extern void init_timer_on_stack_key(struct timer_list *timer,
 153                                    const char *name,
 154                                    struct lock_class_key *key);
 155extern void destroy_timer_on_stack(struct timer_list *timer);
 156#else
 157static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 158static inline void init_timer_on_stack_key(struct timer_list *timer,
 159                                           const char *name,
 160                                           struct lock_class_key *key)
 161{
 162        init_timer_key(timer, name, key);
 163}
 164#endif
 165
 166static inline void setup_timer_key(struct timer_list * timer,
 167                                const char *name,
 168                                struct lock_class_key *key,
 169                                void (*function)(unsigned long),
 170                                unsigned long data)
 171{
 172        timer->function = function;
 173        timer->data = data;
 174        init_timer_key(timer, name, key);
 175}
 176
 177static inline void setup_timer_on_stack_key(struct timer_list *timer,
 178                                        const char *name,
 179                                        struct lock_class_key *key,
 180                                        void (*function)(unsigned long),
 181                                        unsigned long data)
 182{
 183        timer->function = function;
 184        timer->data = data;
 185        init_timer_on_stack_key(timer, name, key);
 186}
 187
 188extern void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
 189                                                const char *name,
 190                                                struct lock_class_key *key,
 191                                                void (*function)(unsigned long),
 192                                                unsigned long data);
 193
 194/**
 195 * timer_pending - is a timer pending?
 196 * @timer: the timer in question
 197 *
 198 * timer_pending will tell whether a given timer is currently pending,
 199 * or not. Callers must ensure serialization wrt. other operations done
 200 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 201 *
 202 * return value: 1 if the timer is pending, 0 if not.
 203 */
 204static inline int timer_pending(const struct timer_list * timer)
 205{
 206        return timer->entry.next != NULL;
 207}
 208
 209extern void add_timer_on(struct timer_list *timer, int cpu);
 210extern int del_timer(struct timer_list * timer);
 211extern int mod_timer(struct timer_list *timer, unsigned long expires);
 212extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 213extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 214
 215extern void set_timer_slack(struct timer_list *time, int slack_hz);
 216
 217#define TIMER_NOT_PINNED        0
 218#define TIMER_PINNED            1
 219/*
 220 * The jiffies value which is added to now, when there is no timer
 221 * in the timer wheel:
 222 */
 223#define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 224
 225/*
 226 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 227 * locks the timer base and does the comparison against the given
 228 * jiffie.
 229 */
 230extern unsigned long get_next_timer_interrupt(unsigned long now);
 231
 232/*
 233 * Timer-statistics info:
 234 */
 235#ifdef CONFIG_TIMER_STATS
 236
 237extern int timer_stats_active;
 238
 239#define TIMER_STATS_FLAG_DEFERRABLE     0x1
 240
 241extern void init_timer_stats(void);
 242
 243extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 244                                     void *timerf, char *comm,
 245                                     unsigned int timer_flag);
 246
 247extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 248                                               void *addr);
 249
 250static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 251{
 252        if (likely(!timer_stats_active))
 253                return;
 254        __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 255}
 256
 257static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 258{
 259        timer->start_site = NULL;
 260}
 261#else
 262static inline void init_timer_stats(void)
 263{
 264}
 265
 266static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 267{
 268}
 269
 270static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 271{
 272}
 273#endif
 274
 275extern void add_timer(struct timer_list *timer);
 276
 277extern int try_to_del_timer_sync(struct timer_list *timer);
 278
 279#ifdef CONFIG_SMP
 280  extern int del_timer_sync(struct timer_list *timer);
 281#else
 282# define del_timer_sync(t)              del_timer(t)
 283#endif
 284
 285#define del_singleshot_timer_sync(t) del_timer_sync(t)
 286
 287extern void init_timers(void);
 288extern void run_local_timers(void);
 289struct hrtimer;
 290extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 291
 292unsigned long __round_jiffies(unsigned long j, int cpu);
 293unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 294unsigned long round_jiffies(unsigned long j);
 295unsigned long round_jiffies_relative(unsigned long j);
 296
 297unsigned long __round_jiffies_up(unsigned long j, int cpu);
 298unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 299unsigned long round_jiffies_up(unsigned long j);
 300unsigned long round_jiffies_up_relative(unsigned long j);
 301
 302#endif
 303
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