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_INITIALIZER(_function, _expires, _data, _flags) { \
  65                 .entry = { .next = TIMER_ENTRY_STATIC },        \
  66                 .function = (_function),                        \
  67                 .expires = (_expires),                          \
  68                 .data = (_data),                                \
  69                 .flags = (_flags),                              \
  70                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  71                         __FILE__ ":" __stringify(__LINE__))     \
  72         }
  73
  74 #define TIMER_INITIALIZER(_function, _expires, _data)           \
  75         __TIMER_INITIALIZER((_function), (_expires), (_data), 0)
  76
  77 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data)    \
  78         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
  79
  80 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)  \
  81         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
  82
  83 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)   \
  84         __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
  85
  86 #define DEFINE_TIMER(_name, _function, _expires, _data)         \
  87         struct timer_list _name =                               \
  88                 TIMER_INITIALIZER(_function, _expires, _data)
  89
  90 void init_timer_key(struct timer_list *timer, unsigned int flags,
  91                     const char *name, struct lock_class_key *key);
  92
  93 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  94 extern void init_timer_on_stack_key(struct timer_list *timer,
  95                                     unsigned int flags, const char *name,
  96                                     struct lock_class_key *key);
  97 extern void destroy_timer_on_stack(struct timer_list *timer);
  98 #else
  99 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 100 static inline void init_timer_on_stack_key(struct timer_list *timer,
 101                                            unsigned int flags, const char *name,
 102                                            struct lock_class_key *key)
 103 {
 104         init_timer_key(timer, flags, name, key);
 105 }
 106 #endif
 107
 108 #ifdef CONFIG_LOCKDEP
 109 #define __init_timer(_timer, _flags)                                    \
 110         do {                                                            \
 111                 static struct lock_class_key __key;                     \
 112                 init_timer_key((_timer), (_flags), #_timer, &__key);    \
 113         } while (0)
 114
 115 #define __init_timer_on_stack(_timer, _flags)                           \
 116         do {                                                            \
 117                 static struct lock_class_key __key;                     \
 118                 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
 119         } while (0)
 120 #else
 121 #define __init_timer(_timer, _flags)                                    \
 122         init_timer_key((_timer), (_flags), NULL, NULL)
 123 #define __init_timer_on_stack(_timer, _flags)                           \
 124         init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
 125 #endif
 126
 127 #define init_timer(timer)                                               \
 128         __init_timer((timer), 0)
 129 #define init_timer_pinned(timer)                                        \
 130         __init_timer((timer), TIMER_PINNED)
 131 #define init_timer_deferrable(timer)                                    \
 132         __init_timer((timer), TIMER_DEFERRABLE)
 133 #define init_timer_pinned_deferrable(timer)                             \
 134         __init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
 135 #define init_timer_on_stack(timer)                                      \
 136         __init_timer_on_stack((timer), 0)
 137
 138 #define __setup_timer(_timer, _fn, _data, _flags)                       \
 139         do {                                                            \
 140                 __init_timer((_timer), (_flags));                       \
 141                 (_timer)->function = (_fn);                             \
 142                 (_timer)->data = (_data);                               \
 143         } while (0)
 144
 145 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)              \
 146         do {                                                            \
 147                 __init_timer_on_stack((_timer), (_flags));              \
 148                 (_timer)->function = (_fn);                             \
 149                 (_timer)->data = (_data);                               \
 150         } while (0)
 151
 152 #define setup_timer(timer, fn, data)                                    \
 153         __setup_timer((timer), (fn), (data), 0)
 154 #define setup_pinned_timer(timer, fn, data)                             \
 155         __setup_timer((timer), (fn), (data), TIMER_PINNED)
 156 #define setup_deferrable_timer(timer, fn, data)                         \
 157         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
 158 #define setup_pinned_deferrable_timer(timer, fn, data)                  \
 159         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 160 #define setup_timer_on_stack(timer, fn, data)                           \
 161         __setup_timer_on_stack((timer), (fn), (data), 0)
 162 #define setup_pinned_timer_on_stack(timer, fn, data)                    \
 163         __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
 164 #define setup_deferrable_timer_on_stack(timer, fn, data)                \
 165         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
 166 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)         \
 167         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 168
 169 /**
 170  * timer_pending - is a timer pending?
 171  * @timer: the timer in question
 172  *
 173  * timer_pending will tell whether a given timer is currently pending,
 174  * or not. Callers must ensure serialization wrt. other operations done
 175  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 176  *
 177  * return value: 1 if the timer is pending, 0 if not.
 178  */
 179 static inline int timer_pending(const struct timer_list * timer)
 180 {
 181         return timer->entry.pprev != NULL;
 182 }
 183
 184 extern void add_timer_on(struct timer_list *timer, int cpu);
 185 extern int del_timer(struct timer_list * timer);
 186 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 187 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 188
 189 /*
 190  * The jiffies value which is added to now, when there is no timer
 191  * in the timer wheel:
 192  */
 193 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 194
 195 extern void add_timer(struct timer_list *timer);
 196
 197 extern int try_to_del_timer_sync(struct timer_list *timer);
 198
 199 #ifdef CONFIG_SMP
 200   extern int del_timer_sync(struct timer_list *timer);
 201 #else
 202 # define del_timer_sync(t)              del_timer(t)
 203 #endif
 204
 205 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 206
 207 extern void init_timers(void);
 208 extern void run_local_timers(void);
 209 struct hrtimer;
 210 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 211
 212 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 213 #include <linux/sysctl.h>
 214
 215 extern unsigned int sysctl_timer_migration;
 216 int timer_migration_handler(struct ctl_table *table, int write,
 217                             void __user *buffer, size_t *lenp,
 218                             loff_t *ppos);
 219 #endif
 220
 221 unsigned long __round_jiffies(unsigned long j, int cpu);
 222 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 223 unsigned long round_jiffies(unsigned long j);
 224 unsigned long round_jiffies_relative(unsigned long j);
 225
 226 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 227 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 228 unsigned long round_jiffies_up(unsigned long j);
 229 unsigned long round_jiffies_up_relative(unsigned long j);
 230
 231 #ifdef CONFIG_HOTPLUG_CPU
 232 int timers_dead_cpu(unsigned int cpu);
 233 #else
 234 #define timers_dead_cpu NULL
 235 #endif
 236
 237 #endif