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
10struct tvec_base;
11
12struct 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	int start_pid;
28	void *start_site;
29	char start_comm[16];
30#endif
31#ifdef CONFIG_LOCKDEP
32	struct lockdep_map lockdep_map;
33#endif
34};
35
36extern 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/*
52 * Note that all tvec_bases are at least 4 byte aligned and lower two bits
53 * of base in timer_list is guaranteed to be zero. Use them for flags.
54 *
55 * A deferrable timer will work normally when the system is busy, but
56 * will not cause a CPU to come out of idle just to service it; instead,
57 * the timer will be serviced when the CPU eventually wakes up with a
58 * subsequent non-deferrable timer.
59 *
60 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
61 * the completion of the running instance from IRQ handlers, for example,
62 * by calling del_timer_sync().
63 *
64 * Note: The irq disabled callback execution is a special case for
65 * workqueue locking issues. It's not meant for executing random crap
66 * with interrupts disabled. Abuse is monitored!
67 */
68#define TIMER_DEFERRABLE		0x1LU
69#define TIMER_IRQSAFE			0x2LU
70
71#define TIMER_FLAG_MASK			0x3LU
72
73#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
74		.entry = { .prev = TIMER_ENTRY_STATIC },	\
75		.function = (_function),			\
76		.expires = (_expires),				\
77		.data = (_data),				\
78		.base = (void *)((unsigned long)&boot_tvec_bases + (_flags)), \
79		.slack = -1,					\
80		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
81			__FILE__ ":" __stringify(__LINE__))	\
82	}
83
84#define TIMER_INITIALIZER(_function, _expires, _data)		\
85	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
86
87#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
88	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
89
90#define DEFINE_TIMER(_name, _function, _expires, _data)		\
91	struct timer_list _name =				\
92		TIMER_INITIALIZER(_function, _expires, _data)
93
94void init_timer_key(struct timer_list *timer, unsigned int flags,
95		    const char *name, struct lock_class_key *key);
96
97#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
98extern void init_timer_on_stack_key(struct timer_list *timer,
99				    unsigned int flags, const char *name,
100				    struct lock_class_key *key);
101extern void destroy_timer_on_stack(struct timer_list *timer);
102#else
103static inline void destroy_timer_on_stack(struct timer_list *timer) { }
104static inline void init_timer_on_stack_key(struct timer_list *timer,
105					   unsigned int flags, const char *name,
106					   struct lock_class_key *key)
107{
108	init_timer_key(timer, flags, name, key);
109}
110#endif
111
112#ifdef CONFIG_LOCKDEP
113#define __init_timer(_timer, _flags)					\
114	do {								\
115		static struct lock_class_key __key;			\
116		init_timer_key((_timer), (_flags), #_timer, &__key);	\
117	} while (0)
118
119#define __init_timer_on_stack(_timer, _flags)				\
120	do {								\
121		static struct lock_class_key __key;			\
122		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
123	} while (0)
124#else
125#define __init_timer(_timer, _flags)					\
126	init_timer_key((_timer), (_flags), NULL, NULL)
127#define __init_timer_on_stack(_timer, _flags)				\
128	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
129#endif
130
131#define init_timer(timer)						\
132	__init_timer((timer), 0)
133#define init_timer_deferrable(timer)					\
134	__init_timer((timer), TIMER_DEFERRABLE)
135#define init_timer_on_stack(timer)					\
136	__init_timer_on_stack((timer), 0)
137
138#define __setup_timer(_timer, _fn, _data, _flags)			\
139	do {								\
140		__init_timer((_timer), (_flags));			\
141		(_timer)->function = (_fn);				\
142		(_timer)->data = (_data);				\
143	} while (0)
144
145#define __setup_timer_on_stack(_timer, _fn, _data, _flags)		\
146	do {								\
147		__init_timer_on_stack((_timer), (_flags));		\
148		(_timer)->function = (_fn);				\
149		(_timer)->data = (_data);				\
150	} while (0)
151
152#define setup_timer(timer, fn, data)					\
153	__setup_timer((timer), (fn), (data), 0)
154#define setup_timer_on_stack(timer, fn, data)				\
155	__setup_timer_on_stack((timer), (fn), (data), 0)
156#define setup_deferrable_timer_on_stack(timer, fn, data)		\
157	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
158
159/**
160 * timer_pending - is a timer pending?
161 * @timer: the timer in question
162 *
163 * timer_pending will tell whether a given timer is currently pending,
164 * or not. Callers must ensure serialization wrt. other operations done
165 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
166 *
167 * return value: 1 if the timer is pending, 0 if not.
168 */
169static inline int timer_pending(const struct timer_list * timer)
170{
171	return timer->entry.next != NULL;
172}
173
174extern void add_timer_on(struct timer_list *timer, int cpu);
175extern int del_timer(struct timer_list * timer);
176extern int mod_timer(struct timer_list *timer, unsigned long expires);
177extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
178extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
179
180extern void set_timer_slack(struct timer_list *time, int slack_hz);
181
182#define TIMER_NOT_PINNED	0
183#define TIMER_PINNED		1
184/*
185 * The jiffies value which is added to now, when there is no timer
186 * in the timer wheel:
187 */
188#define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
189
190/*
191 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
192 * locks the timer base and does the comparison against the given
193 * jiffie.
194 */
195extern unsigned long get_next_timer_interrupt(unsigned long now);
196
197/*
198 * Timer-statistics info:
199 */
200#ifdef CONFIG_TIMER_STATS
201
202extern int timer_stats_active;
203
204#define TIMER_STATS_FLAG_DEFERRABLE	0x1
205
206extern void init_timer_stats(void);
207
208extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
209				     void *timerf, char *comm,
210				     unsigned int timer_flag);
211
212extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
213					       void *addr);
214
215static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
216{
217	if (likely(!timer_stats_active))
218		return;
219	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
220}
221
222static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
223{
224	timer->start_site = NULL;
225}
226#else
227static inline void init_timer_stats(void)
228{
229}
230
231static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
232{
233}
234
235static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
236{
237}
238#endif
239
240extern void add_timer(struct timer_list *timer);
241
242extern int try_to_del_timer_sync(struct timer_list *timer);
243
244#ifdef CONFIG_SMP
245  extern int del_timer_sync(struct timer_list *timer);
246#else
247# define del_timer_sync(t)		del_timer(t)
248#endif
249
250#define del_singleshot_timer_sync(t) del_timer_sync(t)
251
252extern void init_timers(void);
253extern void run_local_timers(void);
254struct hrtimer;
255extern enum hrtimer_restart it_real_fn(struct hrtimer *);
256
257unsigned long __round_jiffies(unsigned long j, int cpu);
258unsigned long __round_jiffies_relative(unsigned long j, int cpu);
259unsigned long round_jiffies(unsigned long j);
260unsigned long round_jiffies_relative(unsigned long j);
261
262unsigned long __round_jiffies_up(unsigned long j, int cpu);
263unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
264unsigned long round_jiffies_up(unsigned long j);
265unsigned long round_jiffies_up_relative(unsigned long j);
266
267#endif
268