xref: /linux-6.15/include/linux/timer.h (revision d67b569f)
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 void fastcall init_timer(struct timer_list * timer);
36 
37 /***
38  * timer_pending - is a timer pending?
39  * @timer: the timer in question
40  *
41  * timer_pending will tell whether a given timer is currently pending,
42  * or not. Callers must ensure serialization wrt. other operations done
43  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
44  *
45  * return value: 1 if the timer is pending, 0 if not.
46  */
47 static inline int timer_pending(const struct timer_list * timer)
48 {
49 	return timer->entry.next != NULL;
50 }
51 
52 extern void add_timer_on(struct timer_list *timer, int cpu);
53 extern int del_timer(struct timer_list * timer);
54 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
55 extern int mod_timer(struct timer_list *timer, unsigned long expires);
56 
57 extern unsigned long next_timer_interrupt(void);
58 
59 /***
60  * add_timer - start a timer
61  * @timer: the timer to be added
62  *
63  * The kernel will do a ->function(->data) callback from the
64  * timer interrupt at the ->expired point in the future. The
65  * current time is 'jiffies'.
66  *
67  * The timer's ->expired, ->function (and if the handler uses it, ->data)
68  * fields must be set prior calling this function.
69  *
70  * Timers with an ->expired field in the past will be executed in the next
71  * timer tick.
72  */
73 static inline void add_timer(struct timer_list * timer)
74 {
75 	__mod_timer(timer, timer->expires);
76 }
77 
78 #ifdef CONFIG_SMP
79   extern int try_to_del_timer_sync(struct timer_list *timer);
80   extern int del_timer_sync(struct timer_list *timer);
81 #else
82 # define try_to_del_timer_sync(t)	del_timer(t)
83 # define del_timer_sync(t)		del_timer(t)
84 #endif
85 
86 #define del_singleshot_timer_sync(t) del_timer_sync(t)
87 
88 extern void init_timers(void);
89 extern void run_local_timers(void);
90 extern void it_real_fn(unsigned long);
91 
92 #endif
93