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         void *start_site;
  28         char start_comm[16];
  29         int start_pid;
  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 #define TIMER_INITIALIZER(_function, _expires, _data) {         \
  52                 .entry = { .prev = TIMER_ENTRY_STATIC },        \
  53                 .function = (_function),                        \
  54                 .expires = (_expires),                          \
  55                 .data = (_data),                                \
  56                 .base = &boot_tvec_bases,                       \
  57                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  58                         __FILE__ ":" __stringify(__LINE__))     \
  59         }
  60
  61 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  62         struct timer_list _name =                               \
  63                 TIMER_INITIALIZER(_function, _expires, _data)
  64
  65 void init_timer_key(struct timer_list *timer,
  66                     const char *name,
  67                     struct lock_class_key *key);
  68 void init_timer_deferrable_key(struct timer_list *timer,
  69                                const char *name,
  70                                struct lock_class_key *key);
  71
  72 #ifdef CONFIG_LOCKDEP
  73 #define init_timer(timer)                                               \
  74         do {                                                            \
  75                 static struct lock_class_key __key;                     \
  76                 init_timer_key((timer), #timer, &__key);                \
  77         } while (0)
  78
  79 #define init_timer_deferrable(timer)                                    \
  80         do {                                                            \
  81                 static struct lock_class_key __key;                     \
  82                 init_timer_deferrable_key((timer), #timer, &__key);     \
  83         } while (0)
  84
  85 #define init_timer_on_stack(timer)                                      \
  86         do {                                                            \
  87                 static struct lock_class_key __key;                     \
  88                 init_timer_on_stack_key((timer), #timer, &__key);       \
  89         } while (0)
  90
  91 #define setup_timer(timer, fn, data)                                    \
  92         do {                                                            \
  93                 static struct lock_class_key __key;                     \
  94                 setup_timer_key((timer), #timer, &__key, (fn), (data));\
  95         } while (0)
  96
  97 #define setup_timer_on_stack(timer, fn, data)                           \
  98         do {                                                            \
  99                 static struct lock_class_key __key;                     \
 100                 setup_timer_on_stack_key((timer), #timer, &__key,       \
 101                                          (fn), (data));                 \
 102         } while (0)
 103 #else
 104 #define init_timer(timer)\
 105         init_timer_key((timer), NULL, NULL)
 106 #define init_timer_deferrable(timer)\
 107         init_timer_deferrable_key((timer), NULL, NULL)
 108 #define init_timer_on_stack(timer)\
 109         init_timer_on_stack_key((timer), NULL, NULL)
 110 #define setup_timer(timer, fn, data)\
 111         setup_timer_key((timer), NULL, NULL, (fn), (data))
 112 #define setup_timer_on_stack(timer, fn, data)\
 113         setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
 114 #endif
 115
 116 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 117 extern void init_timer_on_stack_key(struct timer_list *timer,
 118                                     const char *name,
 119                                     struct lock_class_key *key);
 120 extern void destroy_timer_on_stack(struct timer_list *timer);
 121 #else
 122 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 123 static inline void init_timer_on_stack_key(struct timer_list *timer,
 124                                            const char *name,
 125                                            struct lock_class_key *key)
 126 {
 127         init_timer_key(timer, name, key);
 128 }
 129 #endif
 130
 131 static inline void setup_timer_key(struct timer_list * timer,
 132                                 const char *name,
 133                                 struct lock_class_key *key,
 134                                 void (*function)(unsigned long),
 135                                 unsigned long data)
 136 {
 137         timer->function = function;
 138         timer->data = data;
 139         init_timer_key(timer, name, key);
 140 }
 141
 142 static inline void setup_timer_on_stack_key(struct timer_list *timer,
 143                                         const char *name,
 144                                         struct lock_class_key *key,
 145                                         void (*function)(unsigned long),
 146                                         unsigned long data)
 147 {
 148         timer->function = function;
 149         timer->data = data;
 150         init_timer_on_stack_key(timer, name, key);
 151 }
 152
 153 /**
 154  * timer_pending - is a timer pending?
 155  * @timer: the timer in question
 156  *
 157  * timer_pending will tell whether a given timer is currently pending,
 158  * or not. Callers must ensure serialization wrt. other operations done
 159  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 160  *
 161  * return value: 1 if the timer is pending, 0 if not.
 162  */
 163 static inline int timer_pending(const struct timer_list * timer)
 164 {
 165         return timer->entry.next != NULL;
 166 }
 167
 168 extern void add_timer_on(struct timer_list *timer, int cpu);
 169 extern int del_timer(struct timer_list * timer);
 170 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 171 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 172 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 173
 174 extern void set_timer_slack(struct timer_list *time, int slack_hz);
 175
 176 #define TIMER_NOT_PINNED        0
 177 #define TIMER_PINNED            1
 178 /*
 179  * The jiffies value which is added to now, when there is no timer
 180  * in the timer wheel:
 181  */
 182 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 183
 184 /*
 185  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
 186  * locks the timer base and does the comparison against the given
 187  * jiffie.
 188  */
 189 extern unsigned long get_next_timer_interrupt(unsigned long now);
 190
 191 /*
 192  * Timer-statistics info:
 193  */
 194 #ifdef CONFIG_TIMER_STATS
 195
 196 extern int timer_stats_active;
 197
 198 #define TIMER_STATS_FLAG_DEFERRABLE     0x1
 199
 200 extern void init_timer_stats(void);
 201
 202 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 203                                      void *timerf, char *comm,
 204                                      unsigned int timer_flag);
 205
 206 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 207                                                void *addr);
 208
 209 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 210 {
 211         if (likely(!timer_stats_active))
 212                 return;
 213         __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 214 }
 215
 216 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 217 {
 218         timer->start_site = NULL;
 219 }
 220 #else
 221 static inline void init_timer_stats(void)
 222 {
 223 }
 224
 225 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 226 {
 227 }
 228
 229 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 230 {
 231 }
 232 #endif
 233
 234 extern void add_timer(struct timer_list *timer);
 235
 236 #ifdef CONFIG_SMP
 237   extern int try_to_del_timer_sync(struct timer_list *timer);
 238   extern int del_timer_sync(struct timer_list *timer);
 239 #else
 240 # define try_to_del_timer_sync(t)       del_timer(t)
 241 # define del_timer_sync(t)              del_timer(t)
 242 #endif
 243
 244 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 245
 246 extern void init_timers(void);
 247 extern void run_local_timers(void);
 248 struct hrtimer;
 249 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 250
 251 unsigned long __round_jiffies(unsigned long j, int cpu);
 252 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 253 unsigned long round_jiffies(unsigned long j);
 254 unsigned long round_jiffies_relative(unsigned long j);
 255
 256 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 257 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 258 unsigned long round_jiffies_up(unsigned long j);
 259 unsigned long round_jiffies_up_relative(unsigned long j);
 260
 261 #endif