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1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/list.h>
6 #include <linux/ktime.h>
7 #include <linux/stddef.h>
8 #include <linux/debugobjects.h>
9 #include <linux/stringify.h>
15 * All fields that change during normal runtime grouped to the
18 struct hlist_node entry
;
19 unsigned long expires
;
20 void (*function
)(struct timer_list
*);
24 struct lockdep_map lockdep_map
;
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.
35 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \
36 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
38 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
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.
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().
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!
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
64 #define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
66 #define __TIMER_INITIALIZER(_function, _flags) { \
67 .entry = { .next = TIMER_ENTRY_STATIC }, \
68 .function = (_function), \
70 __TIMER_LOCKDEP_MAP_INITIALIZER( \
71 __FILE__ ":" __stringify(__LINE__)) \
74 #define DEFINE_TIMER(_name, _function) \
75 struct timer_list _name = \
76 __TIMER_INITIALIZER(_function, 0)
79 * LOCKDEP and DEBUG timer interfaces.
81 void init_timer_key(struct timer_list
*timer
,
82 void (*func
)(struct timer_list
*), unsigned int flags
,
83 const char *name
, struct lock_class_key
*key
);
85 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
86 extern void init_timer_on_stack_key(struct timer_list
*timer
,
87 void (*func
)(struct timer_list
*),
88 unsigned int flags
, const char *name
,
89 struct lock_class_key
*key
);
91 static inline void init_timer_on_stack_key(struct timer_list
*timer
,
92 void (*func
)(struct timer_list
*),
95 struct lock_class_key
*key
)
97 init_timer_key(timer
, func
, flags
, name
, key
);
101 #ifdef CONFIG_LOCKDEP
102 #define __init_timer(_timer, _fn, _flags) \
104 static struct lock_class_key __key; \
105 init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\
108 #define __init_timer_on_stack(_timer, _fn, _flags) \
110 static struct lock_class_key __key; \
111 init_timer_on_stack_key((_timer), (_fn), (_flags), \
115 #define __init_timer(_timer, _fn, _flags) \
116 init_timer_key((_timer), (_fn), (_flags), NULL, NULL)
117 #define __init_timer_on_stack(_timer, _fn, _flags) \
118 init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL)
122 * timer_setup - prepare a timer for first use
123 * @timer: the timer in question
124 * @callback: the function to call when timer expires
125 * @flags: any TIMER_* flags
127 * Regular timer initialization should use either DEFINE_TIMER() above,
128 * or timer_setup(). For timers on the stack, timer_setup_on_stack() must
129 * be used and must be balanced with a call to destroy_timer_on_stack().
131 #define timer_setup(timer, callback, flags) \
132 __init_timer((timer), (callback), (flags))
134 #define timer_setup_on_stack(timer, callback, flags) \
135 __init_timer_on_stack((timer), (callback), (flags))
137 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
138 extern void destroy_timer_on_stack(struct timer_list
*timer
);
140 static inline void destroy_timer_on_stack(struct timer_list
*timer
) { }
143 #define from_timer(var, callback_timer, timer_fieldname) \
144 container_of(callback_timer, typeof(*var), timer_fieldname)
147 * timer_pending - is a timer pending?
148 * @timer: the timer in question
150 * timer_pending will tell whether a given timer is currently pending,
151 * or not. Callers must ensure serialization wrt. other operations done
152 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
154 * return value: 1 if the timer is pending, 0 if not.
156 static inline int timer_pending(const struct timer_list
* timer
)
158 return timer
->entry
.pprev
!= NULL
;
161 extern void add_timer_on(struct timer_list
*timer
, int cpu
);
162 extern int del_timer(struct timer_list
* timer
);
163 extern int mod_timer(struct timer_list
*timer
, unsigned long expires
);
164 extern int mod_timer_pending(struct timer_list
*timer
, unsigned long expires
);
165 extern int timer_reduce(struct timer_list
*timer
, unsigned long expires
);
168 * The jiffies value which is added to now, when there is no timer
169 * in the timer wheel:
171 #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
173 extern void add_timer(struct timer_list
*timer
);
175 extern int try_to_del_timer_sync(struct timer_list
*timer
);
178 extern int del_timer_sync(struct timer_list
*timer
);
180 # define del_timer_sync(t) del_timer(t)
183 #define del_singleshot_timer_sync(t) del_timer_sync(t)
185 extern void init_timers(void);
186 extern void run_local_timers(void);
188 extern enum hrtimer_restart
it_real_fn(struct hrtimer
*);
190 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
193 extern unsigned int sysctl_timer_migration
;
194 int timer_migration_handler(struct ctl_table
*table
, int write
,
195 void __user
*buffer
, size_t *lenp
,
199 unsigned long __round_jiffies(unsigned long j
, int cpu
);
200 unsigned long __round_jiffies_relative(unsigned long j
, int cpu
);
201 unsigned long round_jiffies(unsigned long j
);
202 unsigned long round_jiffies_relative(unsigned long j
);
204 unsigned long __round_jiffies_up(unsigned long j
, int cpu
);
205 unsigned long __round_jiffies_up_relative(unsigned long j
, int cpu
);
206 unsigned long round_jiffies_up(unsigned long j
);
207 unsigned long round_jiffies_up_relative(unsigned long j
);
209 #ifdef CONFIG_HOTPLUG_CPU
210 int timers_dead_cpu(unsigned int cpu
);
212 #define timers_dead_cpu NULL