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
  23 #ifdef CONFIG_LOCKDEP
  24         struct lockdep_map      lockdep_map;
  25 #endif
  26 };
  27
  28 #ifdef CONFIG_LOCKDEP
  29 /*
  30  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
  31  * (second argument) here is required, otherwise it could be initialised to
  32  * the copy of the lockdep_map later! We use the pointer to and the string
  33  * "<file>:<line>" as the key resp. the name of the lockdep_map.
  34  */
  35 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                            \
  36         .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
  37 #else
  38 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
  39 #endif
  40
  41 /*
  42  * A deferrable timer will work normally when the system is busy, but
  43  * will not cause a CPU to come out of idle just to service it; instead,
  44  * the timer will be serviced when the CPU eventually wakes up with a
  45  * subsequent non-deferrable timer.
  46  *
  47  * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
  48  * the completion of the running instance from IRQ handlers, for example,
  49  * by calling del_timer_sync().
  50  *
  51  * Note: The irq disabled callback execution is a special case for
  52  * workqueue locking issues. It's not meant for executing random crap
  53  * with interrupts disabled. Abuse is monitored!
  54  */
  55 #define TIMER_CPUMASK           0x0003FFFF
  56 #define TIMER_MIGRATING         0x00040000
  57 #define TIMER_BASEMASK          (TIMER_CPUMASK | TIMER_MIGRATING)
  58 #define TIMER_DEFERRABLE        0x00080000
  59 #define TIMER_PINNED            0x00100000
  60 #define TIMER_IRQSAFE           0x00200000
  61 #define TIMER_ARRAYSHIFT        22
  62 #define TIMER_ARRAYMASK         0xFFC00000
  63
  64 #define TIMER_TRACE_FLAGMASK    (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
  65
  66 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
  67                 .entry = { .next = TIMER_ENTRY_STATIC },        \
  68                 .function = (_function),                        \
  69                 .expires = (_expires),                          \
  70                 .data = (_data),                                \
  71                 .flags = (_flags),                              \
  72                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  73                         __FILE__ ":" __stringify(__LINE__))     \
  74         }
  75
  76 #define TIMER_INITIALIZER(_function, _expires, _data)           \
  77         __TIMER_INITIALIZER((_function), (_expires), (_data), 0)
  78
  79 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data)    \
  80         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
  81
  82 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)  \
  83         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
  84
  85 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)   \
  86         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
  87
  88 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  89         struct timer_list _name =                               \
  90                 TIMER_INITIALIZER(_function, _expires, _data)
  91
  92 void init_timer_key(struct timer_list *timer, unsigned int flags,
  93                     const char *name, struct lock_class_key *key);
  94
  95 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  96 extern void init_timer_on_stack_key(struct timer_list *timer,
  97                                     unsigned int flags, const char *name,
  98                                     struct lock_class_key *key);
  99 extern void destroy_timer_on_stack(struct timer_list *timer);
 100 #else
 101 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 102 static inline void init_timer_on_stack_key(struct timer_list *timer,
 103                                            unsigned int flags, const char *name,
 104                                            struct lock_class_key *key)
 105 {
 106         init_timer_key(timer, flags, name, key);
 107 }
 108 #endif
 109
 110 #ifdef CONFIG_LOCKDEP
 111 #define __init_timer(_timer, _flags)                                    \
 112         do {                                                            \
 113                 static struct lock_class_key __key;                     \
 114                 init_timer_key((_timer), (_flags), #_timer, &__key);    \
 115         } while (0)
 116
 117 #define __init_timer_on_stack(_timer, _flags)                           \
 118         do {                                                            \
 119                 static struct lock_class_key __key;                     \
 120                 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
 121         } while (0)
 122 #else
 123 #define __init_timer(_timer, _flags)                                    \
 124         init_timer_key((_timer), (_flags), NULL, NULL)
 125 #define __init_timer_on_stack(_timer, _flags)                           \
 126         init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
 127 #endif
 128
 129 #define init_timer(timer)                                               \
 130         __init_timer((timer), 0)
 131 #define init_timer_pinned(timer)                                        \
 132         __init_timer((timer), TIMER_PINNED)
 133 #define init_timer_deferrable(timer)                                    \
 134         __init_timer((timer), TIMER_DEFERRABLE)
 135 #define init_timer_pinned_deferrable(timer)                             \
 136         __init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
 137 #define init_timer_on_stack(timer)                                      \
 138         __init_timer_on_stack((timer), 0)
 139
 140 #define __setup_timer(_timer, _fn, _data, _flags)                       \
 141         do {                                                            \
 142                 __init_timer((_timer), (_flags));                       \
 143                 (_timer)->function = (_fn);                             \
 144                 (_timer)->data = (_data);                               \
 145         } while (0)
 146
 147 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)              \
 148         do {                                                            \
 149                 __init_timer_on_stack((_timer), (_flags));              \
 150                 (_timer)->function = (_fn);                             \
 151                 (_timer)->data = (_data);                               \
 152         } while (0)
 153
 154 #define setup_timer(timer, fn, data)                                    \
 155         __setup_timer((timer), (fn), (data), 0)
 156 #define setup_pinned_timer(timer, fn, data)                             \
 157         __setup_timer((timer), (fn), (data), TIMER_PINNED)
 158 #define setup_deferrable_timer(timer, fn, data)                         \
 159         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
 160 #define setup_pinned_deferrable_timer(timer, fn, data)                  \
 161         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 162 #define setup_timer_on_stack(timer, fn, data)                           \
 163         __setup_timer_on_stack((timer), (fn), (data), 0)
 164 #define setup_pinned_timer_on_stack(timer, fn, data)                    \
 165         __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
 166 #define setup_deferrable_timer_on_stack(timer, fn, data)                \
 167         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
 168 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)         \
 169         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 170
 171 /**
 172  * timer_pending - is a timer pending?
 173  * @timer: the timer in question
 174  *
 175  * timer_pending will tell whether a given timer is currently pending,
 176  * or not. Callers must ensure serialization wrt. other operations done
 177  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 178  *
 179  * return value: 1 if the timer is pending, 0 if not.
 180  */
 181 static inline int timer_pending(const struct timer_list * timer)
 182 {
 183         return timer->entry.pprev != NULL;
 184 }
 185
 186 extern void add_timer_on(struct timer_list *timer, int cpu);
 187 extern int del_timer(struct timer_list * timer);
 188 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 189 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 190
 191 /*
 192  * The jiffies value which is added to now, when there is no timer
 193  * in the timer wheel:
 194  */
 195 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 196
 197 extern void add_timer(struct timer_list *timer);
 198
 199 extern int try_to_del_timer_sync(struct timer_list *timer);
 200
 201 #ifdef CONFIG_SMP
 202   extern int del_timer_sync(struct timer_list *timer);
 203 #else
 204 # define del_timer_sync(t)              del_timer(t)
 205 #endif
 206
 207 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 208
 209 extern void init_timers(void);
 210 extern void run_local_timers(void);
 211 struct hrtimer;
 212 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 213
 214 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 215 struct ctl_table;
 216
 217 extern unsigned int sysctl_timer_migration;
 218 int timer_migration_handler(struct ctl_table *table, int write,
 219                             void __user *buffer, size_t *lenp,
 220                             loff_t *ppos);
 221 #endif
 222
 223 unsigned long __round_jiffies(unsigned long j, int cpu);
 224 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 225 unsigned long round_jiffies(unsigned long j);
 226 unsigned long round_jiffies_relative(unsigned long j);
 227
 228 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 229 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 230 unsigned long round_jiffies_up(unsigned long j);
 231 unsigned long round_jiffies_up_relative(unsigned long j);
 232
 233 #ifdef CONFIG_HOTPLUG_CPU
 234 int timers_dead_cpu(unsigned int cpu);
 235 #else
 236 #define timers_dead_cpu NULL
 237 #endif
 238
 239 #endif