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 TIMER_DEFERRABLE                0x1LU
  62
  63 #define TIMER_FLAG_MASK                 0x1LU
  64
  65 #define TIMER_INITIALIZER(_function, _expires, _data) {         \
  66                 .entry = { .prev = TIMER_ENTRY_STATIC },        \
  67                 .function = (_function),                        \
  68                 .expires = (_expires),                          \
  69                 .data = (_data),                                \
  70                 .base = &boot_tvec_bases,                       \
  71                 .slack = -1,                                    \
  72                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  73                         __FILE__ ":" __stringify(__LINE__))     \
  74         }
  75
  76 #define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *)          \
  77                   ((unsigned char *)(ptr) + TIMER_DEFERRABLE))
  78
  79 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\
  80                 .entry = { .prev = TIMER_ENTRY_STATIC },        \
  81                 .function = (_function),                        \
  82                 .expires = (_expires),                          \
  83                 .data = (_data),                                \
  84                 .base = TBASE_MAKE_DEFERRED(&boot_tvec_bases),  \
  85                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  86                         __FILE__ ":" __stringify(__LINE__))     \
  87         }
  88
  89 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  90         struct timer_list _name =                               \
  91                 TIMER_INITIALIZER(_function, _expires, _data)
  92
  93 void init_timer_key(struct timer_list *timer,
  94                     const char *name,
  95                     struct lock_class_key *key);
  96 void init_timer_deferrable_key(struct timer_list *timer,
  97                                const char *name,
  98                                struct lock_class_key *key);
  99
 100 #ifdef CONFIG_LOCKDEP
 101 #define init_timer(timer)                                               \
 102         do {                                                            \
 103                 static struct lock_class_key __key;                     \
 104                 init_timer_key((timer), #timer, &__key);                \
 105         } while (0)
 106
 107 #define init_timer_deferrable(timer)                                    \
 108         do {                                                            \
 109                 static struct lock_class_key __key;                     \
 110                 init_timer_deferrable_key((timer), #timer, &__key);     \
 111         } while (0)
 112
 113 #define init_timer_on_stack(timer)                                      \
 114         do {                                                            \
 115                 static struct lock_class_key __key;                     \
 116                 init_timer_on_stack_key((timer), #timer, &__key);       \
 117         } while (0)
 118
 119 #define setup_timer(timer, fn, data)                                    \
 120         do {                                                            \
 121                 static struct lock_class_key __key;                     \
 122                 setup_timer_key((timer), #timer, &__key, (fn), (data));\
 123         } while (0)
 124
 125 #define setup_timer_on_stack(timer, fn, data)                           \
 126         do {                                                            \
 127                 static struct lock_class_key __key;                     \
 128                 setup_timer_on_stack_key((timer), #timer, &__key,       \
 129                                          (fn), (data));                 \
 130         } while (0)
 131 #define setup_deferrable_timer_on_stack(timer, fn, data)                \
 132         do {                                                            \
 133                 static struct lock_class_key __key;                     \
 134                 setup_deferrable_timer_on_stack_key((timer), #timer,    \
 135                                                     &__key, (fn),       \
 136                                                     (data));            \
 137         } while (0)
 138 #else
 139 #define init_timer(timer)\
 140         init_timer_key((timer), NULL, NULL)
 141 #define init_timer_deferrable(timer)\
 142         init_timer_deferrable_key((timer), NULL, NULL)
 143 #define init_timer_on_stack(timer)\
 144         init_timer_on_stack_key((timer), NULL, NULL)
 145 #define setup_timer(timer, fn, data)\
 146         setup_timer_key((timer), NULL, NULL, (fn), (data))
 147 #define setup_timer_on_stack(timer, fn, data)\
 148         setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 149 #define setup_deferrable_timer_on_stack(timer, fn, data)\
 150         setup_deferrable_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 151 #endif
 152
 153 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 154 extern void init_timer_on_stack_key(struct timer_list *timer,
 155                                     const char *name,
 156                                     struct lock_class_key *key);
 157 extern void destroy_timer_on_stack(struct timer_list *timer);
 158 #else
 159 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 160 static inline void init_timer_on_stack_key(struct timer_list *timer,
 161                                            const char *name,
 162                                            struct lock_class_key *key)
 163 {
 164         init_timer_key(timer, name, key);
 165 }
 166 #endif
 167
 168 static inline void setup_timer_key(struct timer_list * timer,
 169                                 const char *name,
 170                                 struct lock_class_key *key,
 171                                 void (*function)(unsigned long),
 172                                 unsigned long data)
 173 {
 174         timer->function = function;
 175         timer->data = data;
 176         init_timer_key(timer, name, key);
 177 }
 178
 179 static inline void setup_timer_on_stack_key(struct timer_list *timer,
 180                                         const char *name,
 181                                         struct lock_class_key *key,
 182                                         void (*function)(unsigned long),
 183                                         unsigned long data)
 184 {
 185         timer->function = function;
 186         timer->data = data;
 187         init_timer_on_stack_key(timer, name, key);
 188 }
 189
 190 extern void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
 191                                                 const char *name,
 192                                                 struct lock_class_key *key,
 193                                                 void (*function)(unsigned long),
 194                                                 unsigned long data);
 195
 196 /**
 197  * timer_pending - is a timer pending?
 198  * @timer: the timer in question
 199  *
 200  * timer_pending will tell whether a given timer is currently pending,
 201  * or not. Callers must ensure serialization wrt. other operations done
 202  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 203  *
 204  * return value: 1 if the timer is pending, 0 if not.
 205  */
 206 static inline int timer_pending(const struct timer_list * timer)
 207 {
 208         return timer->entry.next != NULL;
 209 }
 210
 211 extern void add_timer_on(struct timer_list *timer, int cpu);
 212 extern int del_timer(struct timer_list * timer);
 213 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 214 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 215 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 216
 217 extern void set_timer_slack(struct timer_list *time, int slack_hz);
 218
 219 #define TIMER_NOT_PINNED        0
 220 #define TIMER_PINNED            1
 221 /*
 222  * The jiffies value which is added to now, when there is no timer
 223  * in the timer wheel:
 224  */
 225 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 226
 227 /*
 228  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 229  * locks the timer base and does the comparison against the given
 230  * jiffie.
 231  */
 232 extern unsigned long get_next_timer_interrupt(unsigned long now);
 233
 234 /*
 235  * Timer-statistics info:
 236  */
 237 #ifdef CONFIG_TIMER_STATS
 238
 239 extern int timer_stats_active;
 240
 241 #define TIMER_STATS_FLAG_DEFERRABLE     0x1
 242
 243 extern void init_timer_stats(void);
 244
 245 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 246                                      void *timerf, char *comm,
 247                                      unsigned int timer_flag);
 248
 249 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 250                                                void *addr);
 251
 252 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 253 {
 254         if (likely(!timer_stats_active))
 255                 return;
 256         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 257 }
 258
 259 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 260 {
 261         timer->start_site = NULL;
 262 }
 263 #else
 264 static inline void init_timer_stats(void)
 265 {
 266 }
 267
 268 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 269 {
 270 }
 271
 272 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 273 {
 274 }
 275 #endif
 276
 277 extern void add_timer(struct timer_list *timer);
 278
 279 extern int try_to_del_timer_sync(struct timer_list *timer);
 280
 281 #ifdef CONFIG_SMP
 282   extern int del_timer_sync(struct timer_list *timer);
 283 #else
 284 # define del_timer_sync(t)              del_timer(t)
 285 #endif
 286
 287 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 288
 289 extern void init_timers(void);
 290 extern void run_local_timers(void);
 291 struct hrtimer;
 292 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 293
 294 unsigned long __round_jiffies(unsigned long j, int cpu);
 295 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 296 unsigned long round_jiffies(unsigned long j);
 297 unsigned long round_jiffies_relative(unsigned long j);
 298
 299 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 300 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 301 unsigned long round_jiffies_up(unsigned long j);
 302 unsigned long round_jiffies_up_relative(unsigned long j);
 303
 304 #endif