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_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
  92void 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
  96extern void init_timer_on_stack_key(struct timer_list *timer,
  97                                    unsigned int flags, const char *name,
  98                                    struct lock_class_key *key);
  99extern void destroy_timer_on_stack(struct timer_list *timer);
 100#else
 101static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 102static 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 */
 181static inline int timer_pending(const struct timer_list * timer)
 182{
 183        return timer->entry.pprev != NULL;
 184}
 185
 186extern void add_timer_on(struct timer_list *timer, int cpu);
 187extern int del_timer(struct timer_list * timer);
 188extern int mod_timer(struct timer_list *timer, unsigned long expires);
 189extern 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
 197extern void add_timer(struct timer_list *timer);
 198
 199extern 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
 209extern void init_timers(void);
 210extern void run_local_timers(void);
 211struct hrtimer;
 212extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 213
 214#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 215struct ctl_table;
 216
 217extern unsigned int sysctl_timer_migration;
 218int timer_migration_handler(struct ctl_table *table, int write,
 219                            void __user *buffer, size_t *lenp,
 220                            loff_t *ppos);
 221#endif
 222
 223unsigned long __round_jiffies(unsigned long j, int cpu);
 224unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 225unsigned long round_jiffies(unsigned long j);
 226unsigned long round_jiffies_relative(unsigned long j);
 227
 228unsigned long __round_jiffies_up(unsigned long j, int cpu);
 229unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 230unsigned long round_jiffies_up(unsigned long j);
 231unsigned long round_jiffies_up_relative(unsigned long j);
 232
 233#ifdef CONFIG_HOTPLUG_CPU
 234int timers_dead_cpu(unsigned int cpu);
 235#else
 236#define timers_dead_cpu NULL
 237#endif
 238
 239#endif
 240