xref: /linux-6.15/include/linux/timer.h (revision 9d64fc08)
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 hlist_node	entry;
18 	unsigned long		expires;
19 	void			(*function)(unsigned long);
20 	unsigned long		data;
21 	u32			flags;
22 
23 #ifdef CONFIG_LOCKDEP
24 	struct lockdep_map	lockdep_map;
25 #endif
26 };
27 
28 #ifdef CONFIG_LOCKDEP
29 /*
30  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
31  * (second argument) here is required, otherwise it could be initialised to
32  * the copy of the lockdep_map later! We use the pointer to and the string
33  * "<file>:<line>" as the key resp. the name of the lockdep_map.
34  */
35 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
36 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
37 #else
38 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
39 #endif
40 
41 /*
42  * A deferrable timer will work normally when the system is busy, but
43  * will not cause a CPU to come out of idle just to service it; instead,
44  * the timer will be serviced when the CPU eventually wakes up with a
45  * subsequent non-deferrable timer.
46  *
47  * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
48  * the completion of the running instance from IRQ handlers, for example,
49  * by calling del_timer_sync().
50  *
51  * Note: The irq disabled callback execution is a special case for
52  * workqueue locking issues. It's not meant for executing random crap
53  * with interrupts disabled. Abuse is monitored!
54  */
55 #define TIMER_CPUMASK		0x0003FFFF
56 #define TIMER_MIGRATING		0x00040000
57 #define TIMER_BASEMASK		(TIMER_CPUMASK | TIMER_MIGRATING)
58 #define TIMER_DEFERRABLE	0x00080000
59 #define TIMER_PINNED		0x00100000
60 #define TIMER_IRQSAFE		0x00200000
61 #define TIMER_ARRAYSHIFT	22
62 #define TIMER_ARRAYMASK		0xFFC00000
63 
64 #define TIMER_TRACE_FLAGMASK	(TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
65 
66 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
67 		.entry = { .next = TIMER_ENTRY_STATIC },	\
68 		.function = (_function),			\
69 		.expires = (_expires),				\
70 		.data = (_data),				\
71 		.flags = (_flags),				\
72 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
73 			__FILE__ ":" __stringify(__LINE__))	\
74 	}
75 
76 #define TIMER_INITIALIZER(_function, _expires, _data)		\
77 	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
78 
79 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data)	\
80 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
81 
82 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
83 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
84 
85 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)	\
86 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
87 
88 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
89 	struct timer_list _name =				\
90 		TIMER_INITIALIZER(_function, _expires, _data)
91 
92 void init_timer_key(struct timer_list *timer, unsigned int flags,
93 		    const char *name, struct lock_class_key *key);
94 
95 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
96 extern void init_timer_on_stack_key(struct timer_list *timer,
97 				    unsigned int flags, const char *name,
98 				    struct lock_class_key *key);
99 extern void destroy_timer_on_stack(struct timer_list *timer);
100 #else
101 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
102 static inline void init_timer_on_stack_key(struct timer_list *timer,
103 					   unsigned int flags, const char *name,
104 					   struct lock_class_key *key)
105 {
106 	init_timer_key(timer, flags, name, key);
107 }
108 #endif
109 
110 #ifdef CONFIG_LOCKDEP
111 #define __init_timer(_timer, _flags)					\
112 	do {								\
113 		static struct lock_class_key __key;			\
114 		init_timer_key((_timer), (_flags), #_timer, &__key);	\
115 	} while (0)
116 
117 #define __init_timer_on_stack(_timer, _flags)				\
118 	do {								\
119 		static struct lock_class_key __key;			\
120 		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
121 	} while (0)
122 #else
123 #define __init_timer(_timer, _flags)					\
124 	init_timer_key((_timer), (_flags), NULL, NULL)
125 #define __init_timer_on_stack(_timer, _flags)				\
126 	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
127 #endif
128 
129 #define init_timer(timer)						\
130 	__init_timer((timer), 0)
131 #define init_timer_pinned(timer)					\
132 	__init_timer((timer), TIMER_PINNED)
133 #define init_timer_deferrable(timer)					\
134 	__init_timer((timer), TIMER_DEFERRABLE)
135 #define init_timer_pinned_deferrable(timer)				\
136 	__init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
137 #define init_timer_on_stack(timer)					\
138 	__init_timer_on_stack((timer), 0)
139 
140 #define __setup_timer(_timer, _fn, _data, _flags)			\
141 	do {								\
142 		__init_timer((_timer), (_flags));			\
143 		(_timer)->function = (_fn);				\
144 		(_timer)->data = (_data);				\
145 	} while (0)
146 
147 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)		\
148 	do {								\
149 		__init_timer_on_stack((_timer), (_flags));		\
150 		(_timer)->function = (_fn);				\
151 		(_timer)->data = (_data);				\
152 	} while (0)
153 
154 #define setup_timer(timer, fn, data)					\
155 	__setup_timer((timer), (fn), (data), 0)
156 #define setup_pinned_timer(timer, fn, data)				\
157 	__setup_timer((timer), (fn), (data), TIMER_PINNED)
158 #define setup_deferrable_timer(timer, fn, data)				\
159 	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
160 #define setup_pinned_deferrable_timer(timer, fn, data)			\
161 	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
162 #define setup_timer_on_stack(timer, fn, data)				\
163 	__setup_timer_on_stack((timer), (fn), (data), 0)
164 #define setup_pinned_timer_on_stack(timer, fn, data)			\
165 	__setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
166 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
167 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
168 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)		\
169 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
170 
171 #define TIMER_DATA_TYPE		unsigned long
172 #define TIMER_FUNC_TYPE		void (*)(TIMER_DATA_TYPE)
173 
174 static inline void timer_setup(struct timer_list *timer,
175 			       void (*callback)(struct timer_list *),
176 			       unsigned int flags)
177 {
178 	__setup_timer(timer, (TIMER_FUNC_TYPE)callback,
179 		      (TIMER_DATA_TYPE)timer, flags);
180 }
181 
182 #define from_timer(var, callback_timer, timer_fieldname) \
183 	container_of(callback_timer, typeof(*var), timer_fieldname)
184 
185 /**
186  * timer_pending - is a timer pending?
187  * @timer: the timer in question
188  *
189  * timer_pending will tell whether a given timer is currently pending,
190  * or not. Callers must ensure serialization wrt. other operations done
191  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
192  *
193  * return value: 1 if the timer is pending, 0 if not.
194  */
195 static inline int timer_pending(const struct timer_list * timer)
196 {
197 	return timer->entry.pprev != NULL;
198 }
199 
200 extern void add_timer_on(struct timer_list *timer, int cpu);
201 extern int del_timer(struct timer_list * timer);
202 extern int mod_timer(struct timer_list *timer, unsigned long expires);
203 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
204 
205 /*
206  * The jiffies value which is added to now, when there is no timer
207  * in the timer wheel:
208  */
209 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
210 
211 extern void add_timer(struct timer_list *timer);
212 
213 extern int try_to_del_timer_sync(struct timer_list *timer);
214 
215 #ifdef CONFIG_SMP
216   extern int del_timer_sync(struct timer_list *timer);
217 #else
218 # define del_timer_sync(t)		del_timer(t)
219 #endif
220 
221 #define del_singleshot_timer_sync(t) del_timer_sync(t)
222 
223 extern void init_timers(void);
224 extern void run_local_timers(void);
225 struct hrtimer;
226 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
227 
228 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
229 struct ctl_table;
230 
231 extern unsigned int sysctl_timer_migration;
232 int timer_migration_handler(struct ctl_table *table, int write,
233 			    void __user *buffer, size_t *lenp,
234 			    loff_t *ppos);
235 #endif
236 
237 unsigned long __round_jiffies(unsigned long j, int cpu);
238 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
239 unsigned long round_jiffies(unsigned long j);
240 unsigned long round_jiffies_relative(unsigned long j);
241 
242 unsigned long __round_jiffies_up(unsigned long j, int cpu);
243 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
244 unsigned long round_jiffies_up(unsigned long j);
245 unsigned long round_jiffies_up_relative(unsigned long j);
246 
247 #ifdef CONFIG_HOTPLUG_CPU
248 int timers_dead_cpu(unsigned int cpu);
249 #else
250 #define timers_dead_cpu NULL
251 #endif
252 
253 #endif
254