xref: /linux-6.15/include/linux/timer.h (revision 59c51591)
1 #ifndef _LINUX_TIMER_H
2 #define _LINUX_TIMER_H
3 
4 #include <linux/list.h>
5 #include <linux/ktime.h>
6 #include <linux/spinlock.h>
7 #include <linux/stddef.h>
8 
9 struct tvec_t_base_s;
10 
11 struct timer_list {
12 	struct list_head entry;
13 	unsigned long expires;
14 
15 	void (*function)(unsigned long);
16 	unsigned long data;
17 
18 	struct tvec_t_base_s *base;
19 #ifdef CONFIG_TIMER_STATS
20 	void *start_site;
21 	char start_comm[16];
22 	int start_pid;
23 #endif
24 };
25 
26 extern struct tvec_t_base_s boot_tvec_bases;
27 
28 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
29 		.function = (_function),			\
30 		.expires = (_expires),				\
31 		.data = (_data),				\
32 		.base = &boot_tvec_bases,			\
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 void fastcall init_timer_deferrable(struct timer_list *timer);
41 
42 static inline void setup_timer(struct timer_list * timer,
43 				void (*function)(unsigned long),
44 				unsigned long data)
45 {
46 	timer->function = function;
47 	timer->data = data;
48 	init_timer(timer);
49 }
50 
51 /**
52  * timer_pending - is a timer pending?
53  * @timer: the timer in question
54  *
55  * timer_pending will tell whether a given timer is currently pending,
56  * or not. Callers must ensure serialization wrt. other operations done
57  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
58  *
59  * return value: 1 if the timer is pending, 0 if not.
60  */
61 static inline int timer_pending(const struct timer_list * timer)
62 {
63 	return timer->entry.next != NULL;
64 }
65 
66 extern void add_timer_on(struct timer_list *timer, int cpu);
67 extern int del_timer(struct timer_list * timer);
68 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
69 extern int mod_timer(struct timer_list *timer, unsigned long expires);
70 
71 /*
72  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
73  * locks the timer base:
74  */
75 extern unsigned long next_timer_interrupt(void);
76 /*
77  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
78  * locks the timer base and does the comparison against the given
79  * jiffie.
80  */
81 extern unsigned long get_next_timer_interrupt(unsigned long now);
82 
83 /*
84  * Timer-statistics info:
85  */
86 #ifdef CONFIG_TIMER_STATS
87 
88 extern void init_timer_stats(void);
89 
90 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
91 				     void *timerf, char * comm);
92 
93 static inline void timer_stats_account_timer(struct timer_list *timer)
94 {
95 	timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
96 				 timer->function, timer->start_comm);
97 }
98 
99 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
100 					       void *addr);
101 
102 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
103 {
104 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
105 }
106 
107 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
108 {
109 	timer->start_site = NULL;
110 }
111 #else
112 static inline void init_timer_stats(void)
113 {
114 }
115 
116 static inline void timer_stats_account_timer(struct timer_list *timer)
117 {
118 }
119 
120 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
121 {
122 }
123 
124 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
125 {
126 }
127 #endif
128 
129 extern void delayed_work_timer_fn(unsigned long __data);
130 
131 /**
132  * add_timer - start a timer
133  * @timer: the timer to be added
134  *
135  * The kernel will do a ->function(->data) callback from the
136  * timer interrupt at the ->expires point in the future. The
137  * current time is 'jiffies'.
138  *
139  * The timer's ->expires, ->function (and if the handler uses it, ->data)
140  * fields must be set prior calling this function.
141  *
142  * Timers with an ->expires field in the past will be executed in the next
143  * timer tick.
144  */
145 static inline void add_timer(struct timer_list *timer)
146 {
147 	BUG_ON(timer_pending(timer));
148 	__mod_timer(timer, timer->expires);
149 }
150 
151 #ifdef CONFIG_SMP
152   extern int try_to_del_timer_sync(struct timer_list *timer);
153   extern int del_timer_sync(struct timer_list *timer);
154 #else
155 # define try_to_del_timer_sync(t)	del_timer(t)
156 # define del_timer_sync(t)		del_timer(t)
157 #endif
158 
159 #define del_singleshot_timer_sync(t) del_timer_sync(t)
160 
161 extern void init_timers(void);
162 extern void run_local_timers(void);
163 struct hrtimer;
164 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
165 
166 unsigned long __round_jiffies(unsigned long j, int cpu);
167 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
168 unsigned long round_jiffies(unsigned long j);
169 unsigned long round_jiffies_relative(unsigned long j);
170 
171 
172 #endif
173