xref: /linux-6.15/include/linux/timer.h (revision ba6e8564)
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 
41 static inline void setup_timer(struct timer_list * timer,
42 				void (*function)(unsigned long),
43 				unsigned long data)
44 {
45 	timer->function = function;
46 	timer->data = data;
47 	init_timer(timer);
48 }
49 
50 /**
51  * timer_pending - is a timer pending?
52  * @timer: the timer in question
53  *
54  * timer_pending will tell whether a given timer is currently pending,
55  * or not. Callers must ensure serialization wrt. other operations done
56  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
57  *
58  * return value: 1 if the timer is pending, 0 if not.
59  */
60 static inline int timer_pending(const struct timer_list * timer)
61 {
62 	return timer->entry.next != NULL;
63 }
64 
65 extern void add_timer_on(struct timer_list *timer, int cpu);
66 extern int del_timer(struct timer_list * timer);
67 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
68 extern int mod_timer(struct timer_list *timer, unsigned long expires);
69 
70 /*
71  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
72  * locks the timer base:
73  */
74 extern unsigned long next_timer_interrupt(void);
75 /*
76  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
77  * locks the timer base and does the comparison against the given
78  * jiffie.
79  */
80 extern unsigned long get_next_timer_interrupt(unsigned long now);
81 
82 /*
83  * Timer-statistics info:
84  */
85 #ifdef CONFIG_TIMER_STATS
86 
87 extern void init_timer_stats(void);
88 
89 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
90 				     void *timerf, char * comm);
91 
92 static inline void timer_stats_account_timer(struct timer_list *timer)
93 {
94 	timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
95 				 timer->function, timer->start_comm);
96 }
97 
98 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
99 					       void *addr);
100 
101 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
102 {
103 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
104 }
105 
106 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
107 {
108 	timer->start_site = NULL;
109 }
110 #else
111 static inline void init_timer_stats(void)
112 {
113 }
114 
115 static inline void timer_stats_account_timer(struct timer_list *timer)
116 {
117 }
118 
119 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
120 {
121 }
122 
123 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
124 {
125 }
126 #endif
127 
128 extern void delayed_work_timer_fn(unsigned long __data);
129 
130 /**
131  * add_timer - start a timer
132  * @timer: the timer to be added
133  *
134  * The kernel will do a ->function(->data) callback from the
135  * timer interrupt at the ->expires point in the future. The
136  * current time is 'jiffies'.
137  *
138  * The timer's ->expires, ->function (and if the handler uses it, ->data)
139  * fields must be set prior calling this function.
140  *
141  * Timers with an ->expires field in the past will be executed in the next
142  * timer tick.
143  */
144 static inline void add_timer(struct timer_list *timer)
145 {
146 	BUG_ON(timer_pending(timer));
147 	__mod_timer(timer, timer->expires);
148 }
149 
150 #ifdef CONFIG_SMP
151   extern int try_to_del_timer_sync(struct timer_list *timer);
152   extern int del_timer_sync(struct timer_list *timer);
153 #else
154 # define try_to_del_timer_sync(t)	del_timer(t)
155 # define del_timer_sync(t)		del_timer(t)
156 #endif
157 
158 #define del_singleshot_timer_sync(t) del_timer_sync(t)
159 
160 extern void init_timers(void);
161 extern void run_local_timers(void);
162 struct hrtimer;
163 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
164 
165 unsigned long __round_jiffies(unsigned long j, int cpu);
166 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
167 unsigned long round_jiffies(unsigned long j);
168 unsigned long round_jiffies_relative(unsigned long j);
169 
170 
171 #endif
172