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 hlist_node       entry;
  18         unsigned long           expires;
  19         void                    (*function)(unsigned long);
  20         unsigned long           data;
  21         u32                     flags;
  22         int                     slack;
  23
  24 #ifdef CONFIG_TIMER_STATS
  25         int                     start_pid;
  26         void                    *start_site;
  27         char                    start_comm[16];
  28 #endif
  29 #ifdef CONFIG_LOCKDEP
  30         struct lockdep_map      lockdep_map;
  31 #endif
  32 };
  33
  34 #ifdef CONFIG_LOCKDEP
  35 /*
  36  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
  37  * (second argument) here is required, otherwise it could be initialised to
  38  * the copy of the lockdep_map later! We use the pointer to and the string
  39  * "<file>:<line>" as the key resp. the name of the lockdep_map.
  40  */
  41 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                            \
  42         .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
  43 #else
  44 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
  45 #endif
  46
  47 /*
  48  * A deferrable timer will work normally when the system is busy, but
  49  * will not cause a CPU to come out of idle just to service it; instead,
  50  * the timer will be serviced when the CPU eventually wakes up with a
  51  * subsequent non-deferrable timer.
  52  *
  53  * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
  54  * the completion of the running instance from IRQ handlers, for example,
  55  * by calling del_timer_sync().
  56  *
  57  * Note: The irq disabled callback execution is a special case for
  58  * workqueue locking issues. It's not meant for executing random crap
  59  * with interrupts disabled. Abuse is monitored!
  60  */
  61 #define TIMER_CPUMASK           0x0007FFFF
  62 #define TIMER_MIGRATING         0x00080000
  63 #define TIMER_BASEMASK          (TIMER_CPUMASK | TIMER_MIGRATING)
  64 #define TIMER_DEFERRABLE        0x00100000
  65 #define TIMER_PINNED            0x00200000
  66 #define TIMER_IRQSAFE           0x00400000
  67
  68 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
  69                 .entry = { .next = TIMER_ENTRY_STATIC },        \
  70                 .function = (_function),                        \
  71                 .expires = (_expires),                          \
  72                 .data = (_data),                                \
  73                 .flags = (_flags),                              \
  74                 .slack = -1,                                    \
  75                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  76                         __FILE__ ":" __stringify(__LINE__))     \
  77         }
  78
  79 #define TIMER_INITIALIZER(_function, _expires, _data)           \
  80         __TIMER_INITIALIZER((_function), (_expires), (_data), 0)
  81
  82 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data)    \
  83         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
  84
  85 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)  \
  86         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
  87
  88 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)   \
  89         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
  90
  91 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  92         struct timer_list _name =                               \
  93                 TIMER_INITIALIZER(_function, _expires, _data)
  94
  95 void init_timer_key(struct timer_list *timer, unsigned int flags,
  96                     const char *name, struct lock_class_key *key);
  97
  98 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  99 extern void init_timer_on_stack_key(struct timer_list *timer,
 100                                     unsigned int flags, const char *name,
 101                                     struct lock_class_key *key);
 102 extern void destroy_timer_on_stack(struct timer_list *timer);
 103 #else
 104 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 105 static inline void init_timer_on_stack_key(struct timer_list *timer,
 106                                            unsigned int flags, const char *name,
 107                                            struct lock_class_key *key)
 108 {
 109         init_timer_key(timer, flags, name, key);
 110 }
 111 #endif
 112
 113 #ifdef CONFIG_LOCKDEP
 114 #define __init_timer(_timer, _flags)                                    \
 115         do {                                                            \
 116                 static struct lock_class_key __key;                     \
 117                 init_timer_key((_timer), (_flags), #_timer, &__key);    \
 118         } while (0)
 119
 120 #define __init_timer_on_stack(_timer, _flags)                           \
 121         do {                                                            \
 122                 static struct lock_class_key __key;                     \
 123                 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
 124         } while (0)
 125 #else
 126 #define __init_timer(_timer, _flags)                                    \
 127         init_timer_key((_timer), (_flags), NULL, NULL)
 128 #define __init_timer_on_stack(_timer, _flags)                           \
 129         init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
 130 #endif
 131
 132 #define init_timer(timer)                                               \
 133         __init_timer((timer), 0)
 134 #define init_timer_pinned(timer)                                        \
 135         __init_timer((timer), TIMER_PINNED)
 136 #define init_timer_deferrable(timer)                                    \
 137         __init_timer((timer), TIMER_DEFERRABLE)
 138 #define init_timer_pinned_deferrable(timer)                             \
 139         __init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
 140 #define init_timer_on_stack(timer)                                      \
 141         __init_timer_on_stack((timer), 0)
 142
 143 #define __setup_timer(_timer, _fn, _data, _flags)                       \
 144         do {                                                            \
 145                 __init_timer((_timer), (_flags));                       \
 146                 (_timer)->function = (_fn);                             \
 147                 (_timer)->data = (_data);                               \
 148         } while (0)
 149
 150 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)              \
 151         do {                                                            \
 152                 __init_timer_on_stack((_timer), (_flags));              \
 153                 (_timer)->function = (_fn);                             \
 154                 (_timer)->data = (_data);                               \
 155         } while (0)
 156
 157 #define setup_timer(timer, fn, data)                                    \
 158         __setup_timer((timer), (fn), (data), 0)
 159 #define setup_pinned_timer(timer, fn, data)                             \
 160         __setup_timer((timer), (fn), (data), TIMER_PINNED)
 161 #define setup_deferrable_timer(timer, fn, data)                         \
 162         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
 163 #define setup_pinned_deferrable_timer(timer, fn, data)                  \
 164         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 165 #define setup_timer_on_stack(timer, fn, data)                           \
 166         __setup_timer_on_stack((timer), (fn), (data), 0)
 167 #define setup_pinned_timer_on_stack(timer, fn, data)                    \
 168         __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
 169 #define setup_deferrable_timer_on_stack(timer, fn, data)                \
 170         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
 171 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)         \
 172         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 173
 174 /**
 175  * timer_pending - is a timer pending?
 176  * @timer: the timer in question
 177  *
 178  * timer_pending will tell whether a given timer is currently pending,
 179  * or not. Callers must ensure serialization wrt. other operations done
 180  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 181  *
 182  * return value: 1 if the timer is pending, 0 if not.
 183  */
 184 static inline int timer_pending(const struct timer_list * timer)
 185 {
 186         return timer->entry.pprev != NULL;
 187 }
 188
 189 extern void add_timer_on(struct timer_list *timer, int cpu);
 190 extern int del_timer(struct timer_list * timer);
 191 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 192 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 193
 194 extern void set_timer_slack(struct timer_list *time, int slack_hz);
 195
 196 /*
 197  * The jiffies value which is added to now, when there is no timer
 198  * in the timer wheel:
 199  */
 200 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 201
 202 /*
 203  * Timer-statistics info:
 204  */
 205 #ifdef CONFIG_TIMER_STATS
 206
 207 extern int timer_stats_active;
 208
 209 extern void init_timer_stats(void);
 210
 211 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 212                                      void *timerf, char *comm, u32 flags);
 213
 214 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 215                                                void *addr);
 216
 217 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 218 {
 219         if (likely(!timer_stats_active))
 220                 return;
 221         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 222 }
 223
 224 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 225 {
 226         timer->start_site = NULL;
 227 }
 228 #else
 229 static inline void init_timer_stats(void)
 230 {
 231 }
 232
 233 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 234 {
 235 }
 236
 237 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 238 {
 239 }
 240 #endif
 241
 242 extern void add_timer(struct timer_list *timer);
 243
 244 extern int try_to_del_timer_sync(struct timer_list *timer);
 245
 246 #ifdef CONFIG_SMP
 247   extern int del_timer_sync(struct timer_list *timer);
 248 #else
 249 # define del_timer_sync(t)              del_timer(t)
 250 #endif
 251
 252 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 253
 254 extern void init_timers(void);
 255 extern void run_local_timers(void);
 256 struct hrtimer;
 257 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 258
 259 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 260 #include <linux/sysctl.h>
 261
 262 extern unsigned int sysctl_timer_migration;
 263 int timer_migration_handler(struct ctl_table *table, int write,
 264                             void __user *buffer, size_t *lenp,
 265                             loff_t *ppos);
 266 #endif
 267
 268 unsigned long __round_jiffies(unsigned long j, int cpu);
 269 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 270 unsigned long round_jiffies(unsigned long j);
 271 unsigned long round_jiffies_relative(unsigned long j);
 272
 273 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 274 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 275 unsigned long round_jiffies_up(unsigned long j);
 276 unsigned long round_jiffies_up_relative(unsigned long j);
 277
 278 #endif