xref: /linux-6.15/include/linux/timer.h (revision 4fafd5b0)
1 #ifndef _LINUX_TIMER_H
2 #define _LINUX_TIMER_H
3 
4 #include <linux/list.h>
5 #include <linux/ktime.h>
6 #include <linux/stddef.h>
7 #include <linux/debugobjects.h>
8 #include <linux/stringify.h>
9 
10 struct tvec_base;
11 
12 struct timer_list {
13 	struct list_head entry;
14 	unsigned long expires;
15 
16 	void (*function)(unsigned long);
17 	unsigned long data;
18 
19 	struct tvec_base *base;
20 #ifdef CONFIG_TIMER_STATS
21 	void *start_site;
22 	char start_comm[16];
23 	int start_pid;
24 #endif
25 #ifdef CONFIG_LOCKDEP
26 	struct lockdep_map lockdep_map;
27 #endif
28 };
29 
30 extern struct tvec_base boot_tvec_bases;
31 
32 #ifdef CONFIG_LOCKDEP
33 /*
34  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
35  * (second argument) here is required, otherwise it could be initialised to
36  * the copy of the lockdep_map later! We use the pointer to and the string
37  * "<file>:<line>" as the key resp. the name of the lockdep_map.
38  */
39 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
40 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
41 #else
42 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
43 #endif
44 
45 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
46 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
47 		.function = (_function),			\
48 		.expires = (_expires),				\
49 		.data = (_data),				\
50 		.base = &boot_tvec_bases,			\
51 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
52 			__FILE__ ":" __stringify(__LINE__))	\
53 	}
54 
55 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
56 	struct timer_list _name =				\
57 		TIMER_INITIALIZER(_function, _expires, _data)
58 
59 void init_timer_key(struct timer_list *timer,
60 		    const char *name,
61 		    struct lock_class_key *key);
62 void init_timer_deferrable_key(struct timer_list *timer,
63 			       const char *name,
64 			       struct lock_class_key *key);
65 
66 #ifdef CONFIG_LOCKDEP
67 #define init_timer(timer)						\
68 	do {								\
69 		static struct lock_class_key __key;			\
70 		init_timer_key((timer), #timer, &__key);		\
71 	} while (0)
72 
73 #define init_timer_deferrable(timer)					\
74 	do {								\
75 		static struct lock_class_key __key;			\
76 		init_timer_deferrable_key((timer), #timer, &__key);	\
77 	} while (0)
78 
79 #define init_timer_on_stack(timer)					\
80 	do {								\
81 		static struct lock_class_key __key;			\
82 		init_timer_on_stack_key((timer), #timer, &__key);	\
83 	} while (0)
84 
85 #define setup_timer(timer, fn, data)					\
86 	do {								\
87 		static struct lock_class_key __key;			\
88 		setup_timer_key((timer), #timer, &__key, (fn), (data));\
89 	} while (0)
90 
91 #define setup_timer_on_stack(timer, fn, data)				\
92 	do {								\
93 		static struct lock_class_key __key;			\
94 		setup_timer_on_stack_key((timer), #timer, &__key,	\
95 					 (fn), (data));			\
96 	} while (0)
97 #else
98 #define init_timer(timer)\
99 	init_timer_key((timer), NULL, NULL)
100 #define init_timer_deferrable(timer)\
101 	init_timer_deferrable_key((timer), NULL, NULL)
102 #define init_timer_on_stack(timer)\
103 	init_timer_on_stack_key((timer), NULL, NULL)
104 #define setup_timer(timer, fn, data)\
105 	setup_timer_key((timer), NULL, NULL, (fn), (data))
106 #define setup_timer_on_stack(timer, fn, data)\
107 	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
108 #endif
109 
110 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
111 extern void init_timer_on_stack_key(struct timer_list *timer,
112 				    const char *name,
113 				    struct lock_class_key *key);
114 extern void destroy_timer_on_stack(struct timer_list *timer);
115 #else
116 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
117 static inline void init_timer_on_stack_key(struct timer_list *timer,
118 					   const char *name,
119 					   struct lock_class_key *key)
120 {
121 	init_timer_key(timer, name, key);
122 }
123 #endif
124 
125 static inline void setup_timer_key(struct timer_list * timer,
126 				const char *name,
127 				struct lock_class_key *key,
128 				void (*function)(unsigned long),
129 				unsigned long data)
130 {
131 	timer->function = function;
132 	timer->data = data;
133 	init_timer_key(timer, name, key);
134 }
135 
136 static inline void setup_timer_on_stack_key(struct timer_list *timer,
137 					const char *name,
138 					struct lock_class_key *key,
139 					void (*function)(unsigned long),
140 					unsigned long data)
141 {
142 	timer->function = function;
143 	timer->data = data;
144 	init_timer_on_stack_key(timer, name, key);
145 }
146 
147 /**
148  * timer_pending - is a timer pending?
149  * @timer: the timer in question
150  *
151  * timer_pending will tell whether a given timer is currently pending,
152  * or not. Callers must ensure serialization wrt. other operations done
153  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
154  *
155  * return value: 1 if the timer is pending, 0 if not.
156  */
157 static inline int timer_pending(const struct timer_list * timer)
158 {
159 	return timer->entry.next != NULL;
160 }
161 
162 extern void add_timer_on(struct timer_list *timer, int cpu);
163 extern int del_timer(struct timer_list * timer);
164 extern int __mod_timer(struct timer_list *timer, unsigned long expires);
165 extern int mod_timer(struct timer_list *timer, unsigned long expires);
166 
167 /*
168  * The jiffies value which is added to now, when there is no timer
169  * in the timer wheel:
170  */
171 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
172 
173 /*
174  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
175  * locks the timer base:
176  */
177 extern unsigned long next_timer_interrupt(void);
178 /*
179  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
180  * locks the timer base and does the comparison against the given
181  * jiffie.
182  */
183 extern unsigned long get_next_timer_interrupt(unsigned long now);
184 
185 /*
186  * Timer-statistics info:
187  */
188 #ifdef CONFIG_TIMER_STATS
189 
190 #define TIMER_STATS_FLAG_DEFERRABLE	0x1
191 
192 extern void init_timer_stats(void);
193 
194 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
195 				     void *timerf, char *comm,
196 				     unsigned int timer_flag);
197 
198 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
199 					       void *addr);
200 
201 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
202 {
203 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
204 }
205 
206 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
207 {
208 	timer->start_site = NULL;
209 }
210 #else
211 static inline void init_timer_stats(void)
212 {
213 }
214 
215 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
216 {
217 }
218 
219 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
220 {
221 }
222 #endif
223 
224 /**
225  * add_timer - start a timer
226  * @timer: the timer to be added
227  *
228  * The kernel will do a ->function(->data) callback from the
229  * timer interrupt at the ->expires point in the future. The
230  * current time is 'jiffies'.
231  *
232  * The timer's ->expires, ->function (and if the handler uses it, ->data)
233  * fields must be set prior calling this function.
234  *
235  * Timers with an ->expires field in the past will be executed in the next
236  * timer tick.
237  */
238 static inline void add_timer(struct timer_list *timer)
239 {
240 	BUG_ON(timer_pending(timer));
241 	__mod_timer(timer, timer->expires);
242 }
243 
244 #ifdef CONFIG_SMP
245   extern int try_to_del_timer_sync(struct timer_list *timer);
246   extern int del_timer_sync(struct timer_list *timer);
247 #else
248 # define try_to_del_timer_sync(t)	del_timer(t)
249 # define del_timer_sync(t)		del_timer(t)
250 #endif
251 
252 #define del_singleshot_timer_sync(t) del_timer_sync(t)
253 
254 extern void init_timers(void);
255 extern void run_local_timers(void);
256 struct hrtimer;
257 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
258 
259 unsigned long __round_jiffies(unsigned long j, int cpu);
260 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
261 unsigned long round_jiffies(unsigned long j);
262 unsigned long round_jiffies_relative(unsigned long j);
263 
264 unsigned long __round_jiffies_up(unsigned long j, int cpu);
265 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
266 unsigned long round_jiffies_up(unsigned long j);
267 unsigned long round_jiffies_up_relative(unsigned long j);
268 
269 #endif
270