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
  10 struct tvec_base;
  11
  12 struct 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
  36 extern 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
  91 void init_timer_key(struct timer_list *timer,
  92                     const char *name,
  93                     struct lock_class_key *key);
  94 void 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
 152 extern void init_timer_on_stack_key(struct timer_list *timer,
 153                                     const char *name,
 154                                     struct lock_class_key *key);
 155 extern void destroy_timer_on_stack(struct timer_list *timer);
 156 #else
 157 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 158 static 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
 166 static 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
 177 static 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
 188 extern 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  */
 204 static inline int timer_pending(const struct timer_list * timer)
 205 {
 206         return timer->entry.next != NULL;
 207 }
 208
 209 extern void add_timer_on(struct timer_list *timer, int cpu);
 210 extern int del_timer(struct timer_list * timer);
 211 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 212 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 213 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 214
 215 extern 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  */
 230 extern unsigned long get_next_timer_interrupt(unsigned long now);
 231
 232 /*
 233  * Timer-statistics info:
 234  */
 235 #ifdef CONFIG_TIMER_STATS
 236
 237 extern int timer_stats_active;
 238
 239 #define TIMER_STATS_FLAG_DEFERRABLE     0x1
 240
 241 extern void init_timer_stats(void);
 242
 243 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 244                                      void *timerf, char *comm,
 245                                      unsigned int timer_flag);
 246
 247 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 248                                                void *addr);
 249
 250 static 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
 257 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 258 {
 259         timer->start_site = NULL;
 260 }
 261 #else
 262 static inline void init_timer_stats(void)
 263 {
 264 }
 265
 266 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 267 {
 268 }
 269
 270 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 271 {
 272 }
 273 #endif
 274
 275 extern void add_timer(struct timer_list *timer);
 276
 277 extern 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
 287 extern void init_timers(void);
 288 extern void run_local_timers(void);
 289 struct hrtimer;
 290 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 291
 292 unsigned long __round_jiffies(unsigned long j, int cpu);
 293 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 294 unsigned long round_jiffies(unsigned long j);
 295 unsigned long round_jiffies_relative(unsigned long j);
 296
 297 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 298 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 299 unsigned long round_jiffies_up(unsigned long j);
 300 unsigned long round_jiffies_up_relative(unsigned long j);
 301
 302 #endif