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, _data, _flags) {         \
  67                 .entry = { .next = TIMER_ENTRY_STATIC },        \
  68                 .function = (_function),                        \
  69                 .data = (_data),                                \
  70                 .flags = (_flags),                              \
  71                 __TIMER_LOCKDEP_MAP_INITIALIZER(                \
  72                         __FILE__ ":" __stringify(__LINE__))     \
  73         }
  74
  75 #define DEFINE_TIMER(_name, _function)                          \
  76         struct timer_list _name =                               \
  77                 __TIMER_INITIALIZER(_function, 0, 0)
  78
  79 void init_timer_key(struct timer_list *timer, unsigned int flags,
  80                     const char *name, struct lock_class_key *key);
  81
  82 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
  83 extern void init_timer_on_stack_key(struct timer_list *timer,
  84                                     unsigned int flags, const char *name,
  85                                     struct lock_class_key *key);
  86 extern void destroy_timer_on_stack(struct timer_list *timer);
  87 #else
  88 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
  89 static inline void init_timer_on_stack_key(struct timer_list *timer,
  90                                            unsigned int flags, const char *name,
  91                                            struct lock_class_key *key)
  92 {
  93         init_timer_key(timer, flags, name, key);
  94 }
  95 #endif
  96
  97 #ifdef CONFIG_LOCKDEP
  98 #define __init_timer(_timer, _flags)                                    \
  99         do {                                                            \
 100                 static struct lock_class_key __key;                     \
 101                 init_timer_key((_timer), (_flags), #_timer, &__key);    \
 102         } while (0)
 103
 104 #define __init_timer_on_stack(_timer, _flags)                           \
 105         do {                                                            \
 106                 static struct lock_class_key __key;                     \
 107                 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
 108         } while (0)
 109 #else
 110 #define __init_timer(_timer, _flags)                                    \
 111         init_timer_key((_timer), (_flags), NULL, NULL)
 112 #define __init_timer_on_stack(_timer, _flags)                           \
 113         init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
 114 #endif
 115
 116 #define init_timer(timer)                                               \
 117         __init_timer((timer), 0)
 118
 119 #define __setup_timer(_timer, _fn, _data, _flags)                       \
 120         do {                                                            \
 121                 __init_timer((_timer), (_flags));                       \
 122                 (_timer)->function = (_fn);                             \
 123                 (_timer)->data = (_data);                               \
 124         } while (0)
 125
 126 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)              \
 127         do {                                                            \
 128                 __init_timer_on_stack((_timer), (_flags));              \
 129                 (_timer)->function = (_fn);                             \
 130                 (_timer)->data = (_data);                               \
 131         } while (0)
 132
 133 #define setup_timer(timer, fn, data)                                    \
 134         __setup_timer((timer), (fn), (data), 0)
 135 #define setup_pinned_timer(timer, fn, data)                             \
 136         __setup_timer((timer), (fn), (data), TIMER_PINNED)
 137 #define setup_deferrable_timer(timer, fn, data)                         \
 138         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
 139 #define setup_pinned_deferrable_timer(timer, fn, data)                  \
 140         __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 141 #define setup_timer_on_stack(timer, fn, data)                           \
 142         __setup_timer_on_stack((timer), (fn), (data), 0)
 143 #define setup_pinned_timer_on_stack(timer, fn, data)                    \
 144         __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
 145 #define setup_deferrable_timer_on_stack(timer, fn, data)                \
 146         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
 147 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)         \
 148         __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 149
 150 #define TIMER_DATA_TYPE         unsigned long
 151 #define TIMER_FUNC_TYPE         void (*)(TIMER_DATA_TYPE)
 152
 153 static inline void timer_setup(struct timer_list *timer,
 154                                void (*callback)(struct timer_list *),
 155                                unsigned int flags)
 156 {
 157         __setup_timer(timer, (TIMER_FUNC_TYPE)callback,
 158                       (TIMER_DATA_TYPE)timer, flags);
 159 }
 160
 161 static inline void timer_setup_on_stack(struct timer_list *timer,
 162                                void (*callback)(struct timer_list *),
 163                                unsigned int flags)
 164 {
 165         __setup_timer_on_stack(timer, (TIMER_FUNC_TYPE)callback,
 166                                (TIMER_DATA_TYPE)timer, flags);
 167 }
 168
 169 #define from_timer(var, callback_timer, timer_fieldname) \
 170         container_of(callback_timer, typeof(*var), timer_fieldname)
 171
 172 /**
 173  * timer_pending - is a timer pending?
 174  * @timer: the timer in question
 175  *
 176  * timer_pending will tell whether a given timer is currently pending,
 177  * or not. Callers must ensure serialization wrt. other operations done
 178  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 179  *
 180  * return value: 1 if the timer is pending, 0 if not.
 181  */
 182 static inline int timer_pending(const struct timer_list * timer)
 183 {
 184         return timer->entry.pprev != NULL;
 185 }
 186
 187 extern void add_timer_on(struct timer_list *timer, int cpu);
 188 extern int del_timer(struct timer_list * timer);
 189 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 190 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 191
 192 /*
 193  * The jiffies value which is added to now, when there is no timer
 194  * in the timer wheel:
 195  */
 196 #define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 197
 198 extern void add_timer(struct timer_list *timer);
 199
 200 extern int try_to_del_timer_sync(struct timer_list *timer);
 201
 202 #ifdef CONFIG_SMP
 203   extern int del_timer_sync(struct timer_list *timer);
 204 #else
 205 # define del_timer_sync(t)              del_timer(t)
 206 #endif
 207
 208 #define del_singleshot_timer_sync(t) del_timer_sync(t)
 209
 210 extern void init_timers(void);
 211 extern void run_local_timers(void);
 212 struct hrtimer;
 213 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 214
 215 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 216 struct ctl_table;
 217
 218 extern unsigned int sysctl_timer_migration;
 219 int timer_migration_handler(struct ctl_table *table, int write,
 220                             void __user *buffer, size_t *lenp,
 221                             loff_t *ppos);
 222 #endif
 223
 224 unsigned long __round_jiffies(unsigned long j, int cpu);
 225 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 226 unsigned long round_jiffies(unsigned long j);
 227 unsigned long round_jiffies_relative(unsigned long j);
 228
 229 unsigned long __round_jiffies_up(unsigned long j, int cpu);
 230 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 231 unsigned long round_jiffies_up(unsigned long j);
 232 unsigned long round_jiffies_up_relative(unsigned long j);
 233
 234 #ifdef CONFIG_HOTPLUG_CPU
 235 int timers_dead_cpu(unsigned int cpu);
 236 #else
 237 #define timers_dead_cpu NULL
 238 #endif
 239
 240 #endif