xref: /linux-6.15/include/linux/timer.h (revision 54a8a222)
1 #ifndef _LINUX_TIMER_H
2 #define _LINUX_TIMER_H
3 
4 #include <linux/config.h>
5 #include <linux/list.h>
6 #include <linux/spinlock.h>
7 #include <linux/stddef.h>
8 
9 struct timer_base_s;
10 
11 struct timer_list {
12 	struct list_head entry;
13 	unsigned long expires;
14 
15 	unsigned long magic;
16 
17 	void (*function)(unsigned long);
18 	unsigned long data;
19 
20 	struct timer_base_s *base;
21 };
22 
23 #define TIMER_MAGIC	0x4b87ad6e
24 
25 extern struct timer_base_s __init_timer_base;
26 
27 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
28 		.function = (_function),			\
29 		.expires = (_expires),				\
30 		.data = (_data),				\
31 		.base = &__init_timer_base,			\
32 		.magic = TIMER_MAGIC,				\
33 	}
34 
35 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
36 	struct timer_list _name =				\
37 		TIMER_INITIALIZER(_function, _expires, _data)
38 
39 void fastcall init_timer(struct timer_list * timer);
40 
41 /***
42  * timer_pending - is a timer pending?
43  * @timer: the timer in question
44  *
45  * timer_pending will tell whether a given timer is currently pending,
46  * or not. Callers must ensure serialization wrt. other operations done
47  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
48  *
49  * return value: 1 if the timer is pending, 0 if not.
50  */
51 static inline int timer_pending(const struct timer_list * timer)
52 {
53 	return timer->entry.next != NULL;
54 }
55 
56 extern void add_timer_on(struct timer_list *timer, int cpu);
57 extern int del_timer(struct timer_list * timer);
58 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
59 extern int mod_timer(struct timer_list *timer, unsigned long expires);
60 
61 extern unsigned long next_timer_interrupt(void);
62 
63 /***
64  * add_timer - start a timer
65  * @timer: the timer to be added
66  *
67  * The kernel will do a ->function(->data) callback from the
68  * timer interrupt at the ->expired point in the future. The
69  * current time is 'jiffies'.
70  *
71  * The timer's ->expired, ->function (and if the handler uses it, ->data)
72  * fields must be set prior calling this function.
73  *
74  * Timers with an ->expired field in the past will be executed in the next
75  * timer tick.
76  */
77 static inline void add_timer(struct timer_list * timer)
78 {
79 	__mod_timer(timer, timer->expires);
80 }
81 
82 #ifdef CONFIG_SMP
83   extern int try_to_del_timer_sync(struct timer_list *timer);
84   extern int del_timer_sync(struct timer_list *timer);
85 #else
86 # define try_to_del_timer_sync(t)	del_timer(t)
87 # define del_timer_sync(t)		del_timer(t)
88 #endif
89 
90 #define del_singleshot_timer_sync(t) del_timer_sync(t)
91 
92 extern void init_timers(void);
93 extern void run_local_timers(void);
94 extern void it_real_fn(unsigned long);
95 
96 #endif
97