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 hlist_node	entry;
18	unsigned long		expires;
19	void			(*function)(unsigned long);
20	unsigned long		data;
21	u32			flags;
22	int			slack;
23
24#ifdef CONFIG_TIMER_STATS
25	int			start_pid;
26	void			*start_site;
27	char			start_comm[16];
28#endif
29#ifdef CONFIG_LOCKDEP
30	struct lockdep_map	lockdep_map;
31#endif
32};
33
34#ifdef CONFIG_LOCKDEP
35/*
36 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
37 * (second argument) here is required, otherwise it could be initialised to
38 * the copy of the lockdep_map later! We use the pointer to and the string
39 * "<file>:<line>" as the key resp. the name of the lockdep_map.
40 */
41#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
42	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
43#else
44#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
45#endif
46
47/*
48 * A deferrable timer will work normally when the system is busy, but
49 * will not cause a CPU to come out of idle just to service it; instead,
50 * the timer will be serviced when the CPU eventually wakes up with a
51 * subsequent non-deferrable timer.
52 *
53 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
54 * the completion of the running instance from IRQ handlers, for example,
55 * by calling del_timer_sync().
56 *
57 * Note: The irq disabled callback execution is a special case for
58 * workqueue locking issues. It's not meant for executing random crap
59 * with interrupts disabled. Abuse is monitored!
60 */
61#define TIMER_CPUMASK		0x0007FFFF
62#define TIMER_MIGRATING		0x00080000
63#define TIMER_BASEMASK		(TIMER_CPUMASK | TIMER_MIGRATING)
64#define TIMER_DEFERRABLE	0x00100000
65#define TIMER_IRQSAFE		0x00200000
66
67#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
68		.entry = { .next = TIMER_ENTRY_STATIC },	\
69		.function = (_function),			\
70		.expires = (_expires),				\
71		.data = (_data),				\
72		.flags = (_flags),				\
73		.slack = -1,					\
74		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
75			__FILE__ ":" __stringify(__LINE__))	\
76	}
77
78#define TIMER_INITIALIZER(_function, _expires, _data)		\
79	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
80
81#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
82	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
83
84#define DEFINE_TIMER(_name, _function, _expires, _data)		\
85	struct timer_list _name =				\
86		TIMER_INITIALIZER(_function, _expires, _data)
87
88void init_timer_key(struct timer_list *timer, unsigned int flags,
89		    const char *name, struct lock_class_key *key);
90
91#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
92extern void init_timer_on_stack_key(struct timer_list *timer,
93				    unsigned int flags, const char *name,
94				    struct lock_class_key *key);
95extern void destroy_timer_on_stack(struct timer_list *timer);
96#else
97static inline void destroy_timer_on_stack(struct timer_list *timer) { }
98static inline void init_timer_on_stack_key(struct timer_list *timer,
99					   unsigned int flags, const char *name,
100					   struct lock_class_key *key)
101{
102	init_timer_key(timer, flags, name, key);
103}
104#endif
105
106#ifdef CONFIG_LOCKDEP
107#define __init_timer(_timer, _flags)					\
108	do {								\
109		static struct lock_class_key __key;			\
110		init_timer_key((_timer), (_flags), #_timer, &__key);	\
111	} while (0)
112
113#define __init_timer_on_stack(_timer, _flags)				\
114	do {								\
115		static struct lock_class_key __key;			\
116		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
117	} while (0)
118#else
119#define __init_timer(_timer, _flags)					\
120	init_timer_key((_timer), (_flags), NULL, NULL)
121#define __init_timer_on_stack(_timer, _flags)				\
122	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
123#endif
124
125#define init_timer(timer)						\
126	__init_timer((timer), 0)
127#define init_timer_deferrable(timer)					\
128	__init_timer((timer), TIMER_DEFERRABLE)
129#define init_timer_on_stack(timer)					\
130	__init_timer_on_stack((timer), 0)
131
132#define __setup_timer(_timer, _fn, _data, _flags)			\
133	do {								\
134		__init_timer((_timer), (_flags));			\
135		(_timer)->function = (_fn);				\
136		(_timer)->data = (_data);				\
137	} while (0)
138
139#define __setup_timer_on_stack(_timer, _fn, _data, _flags)		\
140	do {								\
141		__init_timer_on_stack((_timer), (_flags));		\
142		(_timer)->function = (_fn);				\
143		(_timer)->data = (_data);				\
144	} while (0)
145
146#define setup_timer(timer, fn, data)					\
147	__setup_timer((timer), (fn), (data), 0)
148#define setup_timer_on_stack(timer, fn, data)				\
149	__setup_timer_on_stack((timer), (fn), (data), 0)
150#define setup_deferrable_timer_on_stack(timer, fn, data)		\
151	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
152
153/**
154 * timer_pending - is a timer pending?
155 * @timer: the timer in question
156 *
157 * timer_pending will tell whether a given timer is currently pending,
158 * or not. Callers must ensure serialization wrt. other operations done
159 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
160 *
161 * return value: 1 if the timer is pending, 0 if not.
162 */
163static inline int timer_pending(const struct timer_list * timer)
164{
165	return timer->entry.pprev != NULL;
166}
167
168extern void add_timer_on(struct timer_list *timer, int cpu);
169extern int del_timer(struct timer_list * timer);
170extern int mod_timer(struct timer_list *timer, unsigned long expires);
171extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
172extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
173
174extern void set_timer_slack(struct timer_list *time, int slack_hz);
175
176#define TIMER_NOT_PINNED	0
177#define TIMER_PINNED		1
178/*
179 * The jiffies value which is added to now, when there is no timer
180 * in the timer wheel:
181 */
182#define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
183
184/*
185 * Timer-statistics info:
186 */
187#ifdef CONFIG_TIMER_STATS
188
189extern int timer_stats_active;
190
191extern void init_timer_stats(void);
192
193extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
194				     void *timerf, char *comm, u32 flags);
195
196extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
197					       void *addr);
198
199static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
200{
201	if (likely(!timer_stats_active))
202		return;
203	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
204}
205
206static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
207{
208	timer->start_site = NULL;
209}
210#else
211static inline void init_timer_stats(void)
212{
213}
214
215static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
216{
217}
218
219static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
220{
221}
222#endif
223
224extern void add_timer(struct timer_list *timer);
225
226extern int try_to_del_timer_sync(struct timer_list *timer);
227
228#ifdef CONFIG_SMP
229  extern int del_timer_sync(struct timer_list *timer);
230#else
231# define del_timer_sync(t)		del_timer(t)
232#endif
233
234#define del_singleshot_timer_sync(t) del_timer_sync(t)
235
236extern void init_timers(void);
237extern void run_local_timers(void);
238struct hrtimer;
239extern enum hrtimer_restart it_real_fn(struct hrtimer *);
240
241#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
242#include <linux/sysctl.h>
243
244extern unsigned int sysctl_timer_migration;
245int timer_migration_handler(struct ctl_table *table, int write,
246			    void __user *buffer, size_t *lenp,
247			    loff_t *ppos);
248#endif
249
250unsigned long __round_jiffies(unsigned long j, int cpu);
251unsigned long __round_jiffies_relative(unsigned long j, int cpu);
252unsigned long round_jiffies(unsigned long j);
253unsigned long round_jiffies_relative(unsigned long j);
254
255unsigned long __round_jiffies_up(unsigned long j, int cpu);
256unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
257unsigned long round_jiffies_up(unsigned long j);
258unsigned long round_jiffies_up_relative(unsigned long j);
259
260#endif
261