LXR linux/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
  10struct tvec_base;
  11
  12struct 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_TIMER_STATS
  24        int                     start_pid;
  25        void                    *start_site;
  26        char                    start_comm[16];
  27#endif
  28#ifdef CONFIG_LOCKDEP
  29        struct lockdep_map      lockdep_map;
  30#endif
  31};
  32
  33#ifdef CONFIG_LOCKDEP
  34/*
  35 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
  36 * (second argument) here is required, otherwise it could be initialised to
  37 * the copy of the lockdep_map later! We use the pointer to and the string
  38 * "<file>:<line>" as the key resp. the name of the lockdep_map.
  39 */
  40#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                            \
  41        .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
  42#else
  43#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
  44#endif
  45
  46/*
  47 * A deferrable timer will work normally when the system is busy, but
  48 * will not cause a CPU to come out of idle just to service it; instead,
  49 * the timer will be serviced when the CPU eventually wakes up with a
  50 * subsequent non-deferrable timer.
  51 *
  52 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
  53 * the completion of the running instance from IRQ handlers, for example,
  54 * by calling del_timer_sync().
  55 *
  56 * Note: The irq disabled callback execution is a special case for
  57 * workqueue locking issues. It's not meant for executing random crap
  58 * with interrupts disabled. Abuse is monitored!
  59 */
  60#define TIMER_CPUMASK           0x0003FFFF
  61#define TIMER_MIGRATING         0x00040000
  62#define TIMER_BASEMASK          (TIMER_CPUMASK | TIMER_MIGRATING)
  63#define TIMER_DEFERRABLE        0x00080000
  64#define TIMER_PINNED            0x00100000
  65#define TIMER_IRQSAFE           0x00200000
  66#define TIMER_ARRAYSHIFT        22
  67#define TIMER_ARRAYMASK         0xFFC00000
  68
  69#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
  70                .entry = { .next = TIMER_ENTRY_STATIC },        \
  71                .function = (_function),                        \
  72                .expires = (_expires),                          \
  73                .data = (_data),                                \
  74                .flags = (_flags),                              \
  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
  95void 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
  99extern void init_timer_on_stack_key(struct timer_list *timer,
 100                                    unsigned int flags, const char *name,
 101                                    struct lock_class_key *key);
 102extern void destroy_timer_on_stack(struct timer_list *timer);
 103#else
 104static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 105static 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 */
 184static inline int timer_pending(const struct timer_list * timer)
 185{
 186        return timer->entry.pprev != NULL;
 187}
 188
 189extern void add_timer_on(struct timer_list *timer, int cpu);
 190extern int del_timer(struct timer_list * timer);
 191extern int mod_timer(struct timer_list *timer, unsigned long expires);
 192extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
 193
 194/*
 195 * The jiffies value which is added to now, when there is no timer
 196 * in the timer wheel:
 197 */
 198#define NEXT_TIMER_MAX_DELTA    ((1UL << 30) - 1)
 199
 200/*
 201 * Timer-statistics info:
 202 */
 203#ifdef CONFIG_TIMER_STATS
 204
 205extern int timer_stats_active;
 206
 207extern void init_timer_stats(void);
 208
 209extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
 210                                     void *timerf, char *comm, u32 flags);
 211
 212extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
 213                                               void *addr);
 214
 215static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 216{
 217        if (likely(!timer_stats_active))
 218                return;
 219        __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
 220}
 221
 222static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 223{
 224        timer->start_site = NULL;
 225}
 226#else
 227static inline void init_timer_stats(void)
 228{
 229}
 230
 231static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
 232{
 233}
 234
 235static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
 236{
 237}
 238#endif
 239
 240extern void add_timer(struct timer_list *timer);
 241
 242extern int try_to_del_timer_sync(struct timer_list *timer);
 243
 244#ifdef CONFIG_SMP
 245  extern int del_timer_sync(struct timer_list *timer);
 246#else
 247# define del_timer_sync(t)              del_timer(t)
 248#endif
 249
 250#define del_singleshot_timer_sync(t) del_timer_sync(t)
 251
 252extern void init_timers(void);
 253extern void run_local_timers(void);
 254struct hrtimer;
 255extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 256
 257#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 258#include <linux/sysctl.h>
 259
 260extern unsigned int sysctl_timer_migration;
 261int timer_migration_handler(struct ctl_table *table, int write,
 262                            void __user *buffer, size_t *lenp,
 263                            loff_t *ppos);
 264#endif
 265
 266unsigned long __round_jiffies(unsigned long j, int cpu);
 267unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 268unsigned long round_jiffies(unsigned long j);
 269unsigned long round_jiffies_relative(unsigned long j);
 270
 271unsigned long __round_jiffies_up(unsigned long j, int cpu);
 272unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 273unsigned long round_jiffies_up(unsigned long j);
 274unsigned long round_jiffies_up_relative(unsigned long j);
 275
 276#ifdef CONFIG_HOTPLUG_CPU
 277int timers_dead_cpu(unsigned int cpu);
 278#else
 279#define timers_dead_cpu NULL
 280#endif
 281
 282#endif
 283