xref: /linux-6.15/include/linux/timer.h (revision 5bf2b193)
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 	/*
14 	 * All fields that change during normal runtime grouped to the
15 	 * same cacheline
16 	 */
17 	struct list_head entry;
18 	unsigned long expires;
19 	struct tvec_base *base;
20 
21 	void (*function)(unsigned long);
22 	unsigned long data;
23 
24 	int slack;
25 
26 #ifdef CONFIG_TIMER_STATS
27 	void *start_site;
28 	char start_comm[16];
29 	int start_pid;
30 #endif
31 #ifdef CONFIG_LOCKDEP
32 	struct lockdep_map lockdep_map;
33 #endif
34 };
35 
36 extern struct tvec_base boot_tvec_bases;
37 
38 #ifdef CONFIG_LOCKDEP
39 /*
40  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
41  * (second argument) here is required, otherwise it could be initialised to
42  * the copy of the lockdep_map later! We use the pointer to and the string
43  * "<file>:<line>" as the key resp. the name of the lockdep_map.
44  */
45 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
46 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
47 #else
48 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
49 #endif
50 
51 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
52 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
53 		.function = (_function),			\
54 		.expires = (_expires),				\
55 		.data = (_data),				\
56 		.base = &boot_tvec_bases,			\
57 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
58 			__FILE__ ":" __stringify(__LINE__))	\
59 	}
60 
61 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
62 	struct timer_list _name =				\
63 		TIMER_INITIALIZER(_function, _expires, _data)
64 
65 void init_timer_key(struct timer_list *timer,
66 		    const char *name,
67 		    struct lock_class_key *key);
68 void init_timer_deferrable_key(struct timer_list *timer,
69 			       const char *name,
70 			       struct lock_class_key *key);
71 
72 #ifdef CONFIG_LOCKDEP
73 #define init_timer(timer)						\
74 	do {								\
75 		static struct lock_class_key __key;			\
76 		init_timer_key((timer), #timer, &__key);		\
77 	} while (0)
78 
79 #define init_timer_deferrable(timer)					\
80 	do {								\
81 		static struct lock_class_key __key;			\
82 		init_timer_deferrable_key((timer), #timer, &__key);	\
83 	} while (0)
84 
85 #define init_timer_on_stack(timer)					\
86 	do {								\
87 		static struct lock_class_key __key;			\
88 		init_timer_on_stack_key((timer), #timer, &__key);	\
89 	} while (0)
90 
91 #define setup_timer(timer, fn, data)					\
92 	do {								\
93 		static struct lock_class_key __key;			\
94 		setup_timer_key((timer), #timer, &__key, (fn), (data));\
95 	} while (0)
96 
97 #define setup_timer_on_stack(timer, fn, data)				\
98 	do {								\
99 		static struct lock_class_key __key;			\
100 		setup_timer_on_stack_key((timer), #timer, &__key,	\
101 					 (fn), (data));			\
102 	} while (0)
103 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
104 	do {								\
105 		static struct lock_class_key __key;			\
106 		setup_deferrable_timer_on_stack_key((timer), #timer,	\
107 						    &__key, (fn),	\
108 						    (data));		\
109 	} while (0)
110 #else
111 #define init_timer(timer)\
112 	init_timer_key((timer), NULL, NULL)
113 #define init_timer_deferrable(timer)\
114 	init_timer_deferrable_key((timer), NULL, NULL)
115 #define init_timer_on_stack(timer)\
116 	init_timer_on_stack_key((timer), NULL, NULL)
117 #define setup_timer(timer, fn, data)\
118 	setup_timer_key((timer), NULL, NULL, (fn), (data))
119 #define setup_timer_on_stack(timer, fn, data)\
120 	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
121 #define setup_deferrable_timer_on_stack(timer, fn, data)\
122 	setup_deferrable_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
123 #endif
124 
125 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
126 extern void init_timer_on_stack_key(struct timer_list *timer,
127 				    const char *name,
128 				    struct lock_class_key *key);
129 extern void destroy_timer_on_stack(struct timer_list *timer);
130 #else
131 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
132 static inline void init_timer_on_stack_key(struct timer_list *timer,
133 					   const char *name,
134 					   struct lock_class_key *key)
135 {
136 	init_timer_key(timer, name, key);
137 }
138 #endif
139 
140 static inline void setup_timer_key(struct timer_list * timer,
141 				const char *name,
142 				struct lock_class_key *key,
143 				void (*function)(unsigned long),
144 				unsigned long data)
145 {
146 	timer->function = function;
147 	timer->data = data;
148 	init_timer_key(timer, name, key);
149 }
150 
151 static inline void setup_timer_on_stack_key(struct timer_list *timer,
152 					const char *name,
153 					struct lock_class_key *key,
154 					void (*function)(unsigned long),
155 					unsigned long data)
156 {
157 	timer->function = function;
158 	timer->data = data;
159 	init_timer_on_stack_key(timer, name, key);
160 }
161 
162 extern void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
163 						const char *name,
164 						struct lock_class_key *key,
165 						void (*function)(unsigned long),
166 						unsigned long data);
167 
168 /**
169  * timer_pending - is a timer pending?
170  * @timer: the timer in question
171  *
172  * timer_pending will tell whether a given timer is currently pending,
173  * or not. Callers must ensure serialization wrt. other operations done
174  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
175  *
176  * return value: 1 if the timer is pending, 0 if not.
177  */
178 static inline int timer_pending(const struct timer_list * timer)
179 {
180 	return timer->entry.next != NULL;
181 }
182 
183 extern void add_timer_on(struct timer_list *timer, int cpu);
184 extern int del_timer(struct timer_list * timer);
185 extern int mod_timer(struct timer_list *timer, unsigned long expires);
186 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
187 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
188 
189 extern void set_timer_slack(struct timer_list *time, int slack_hz);
190 
191 #define TIMER_NOT_PINNED	0
192 #define TIMER_PINNED		1
193 /*
194  * The jiffies value which is added to now, when there is no timer
195  * in the timer wheel:
196  */
197 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
198 
199 /*
200  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
201  * locks the timer base and does the comparison against the given
202  * jiffie.
203  */
204 extern unsigned long get_next_timer_interrupt(unsigned long now);
205 
206 /*
207  * Timer-statistics info:
208  */
209 #ifdef CONFIG_TIMER_STATS
210 
211 extern int timer_stats_active;
212 
213 #define TIMER_STATS_FLAG_DEFERRABLE	0x1
214 
215 extern void init_timer_stats(void);
216 
217 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
218 				     void *timerf, char *comm,
219 				     unsigned int timer_flag);
220 
221 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
222 					       void *addr);
223 
224 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
225 {
226 	if (likely(!timer_stats_active))
227 		return;
228 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
229 }
230 
231 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
232 {
233 	timer->start_site = NULL;
234 }
235 #else
236 static inline void init_timer_stats(void)
237 {
238 }
239 
240 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
241 {
242 }
243 
244 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
245 {
246 }
247 #endif
248 
249 extern void add_timer(struct timer_list *timer);
250 
251 #ifdef CONFIG_SMP
252   extern int try_to_del_timer_sync(struct timer_list *timer);
253   extern int del_timer_sync(struct timer_list *timer);
254 #else
255 # define try_to_del_timer_sync(t)	del_timer(t)
256 # define del_timer_sync(t)		del_timer(t)
257 #endif
258 
259 #define del_singleshot_timer_sync(t) del_timer_sync(t)
260 
261 extern void init_timers(void);
262 extern void run_local_timers(void);
263 struct hrtimer;
264 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
265 
266 unsigned long __round_jiffies(unsigned long j, int cpu);
267 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
268 unsigned long round_jiffies(unsigned long j);
269 unsigned long round_jiffies_relative(unsigned long j);
270 
271 unsigned long __round_jiffies_up(unsigned long j, int cpu);
272 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
273 unsigned long round_jiffies_up(unsigned long j);
274 unsigned long round_jiffies_up_relative(unsigned long j);
275 
276 #endif
277