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1/* linux/include/linux/tick.h
2 *
3 * This file contains the structure definitions for tick related functions
4 *
5 */
6#ifndef _LINUX_TICK_H
7#define _LINUX_TICK_H
8
9#include <linux/clockchips.h>
10
11#ifdef CONFIG_GENERIC_CLOCKEVENTS
12
13enum tick_device_mode {
14 TICKDEV_MODE_PERIODIC,
15 TICKDEV_MODE_ONESHOT,
16};
17
18struct tick_device {
19 struct clock_event_device *evtdev;
20 enum tick_device_mode mode;
21};
22
23enum tick_nohz_mode {
24 NOHZ_MODE_INACTIVE,
25 NOHZ_MODE_LOWRES,
26 NOHZ_MODE_HIGHRES,
27};
28
29/**
30 * struct tick_sched - sched tick emulation and no idle tick control/stats
31 * @sched_timer: hrtimer to schedule the periodic tick in high
32 * resolution mode
33 * @idle_tick: Store the last idle tick expiry time when the tick
34 * timer is modified for idle sleeps. This is necessary
35 * to resume the tick timer operation in the timeline
36 * when the CPU returns from idle
37 * @tick_stopped: Indicator that the idle tick has been stopped
38 * @idle_jiffies: jiffies at the entry to idle for idle time accounting
39 * @idle_calls: Total number of idle calls
40 * @idle_sleeps: Number of idle calls, where the sched tick was stopped
41 * @idle_entrytime: Time when the idle call was entered
42 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
43 */
44struct tick_sched {
45 struct hrtimer sched_timer;
46 unsigned long check_clocks;
47 enum tick_nohz_mode nohz_mode;
48 ktime_t idle_tick;
49 int tick_stopped;
50 unsigned long idle_jiffies;
51 unsigned long idle_calls;
52 unsigned long idle_sleeps;
53 ktime_t idle_entrytime;
54 ktime_t idle_sleeptime;
55 unsigned long last_jiffies;
56 unsigned long next_jiffies;
57 ktime_t idle_expires;
58};
59
60extern void __init tick_init(void);
61extern int tick_is_oneshot_available(void);
62extern struct tick_device *tick_get_device(int cpu);
63
64# ifdef CONFIG_HIGH_RES_TIMERS
65extern int tick_init_highres(void);
66extern int tick_program_event(ktime_t expires, int force);
67extern void tick_setup_sched_timer(void);
68extern void tick_cancel_sched_timer(int cpu);
69# else
70static inline void tick_cancel_sched_timer(int cpu) { }
71# endif /* HIGHRES */
72
73# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
74extern struct tick_device *tick_get_broadcast_device(void);
75extern cpumask_t *tick_get_broadcast_mask(void);
76
77# ifdef CONFIG_TICK_ONESHOT
78extern cpumask_t *tick_get_broadcast_oneshot_mask(void);
79# endif
80
81# endif /* BROADCAST */
82
83# ifdef CONFIG_TICK_ONESHOT
84extern void tick_clock_notify(void);
85extern int tick_check_oneshot_change(int allow_nohz);
86extern struct tick_sched *tick_get_tick_sched(int cpu);
87# else
88static inline void tick_clock_notify(void) { }
89static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
90# endif
91
92#else /* CONFIG_GENERIC_CLOCKEVENTS */
93static inline void tick_init(void) { }
94static inline void tick_cancel_sched_timer(int cpu) { }
95static inline void tick_clock_notify(void) { }
96static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
97#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
98
99# ifdef CONFIG_NO_HZ
100extern void tick_nohz_stop_sched_tick(void);
101extern void tick_nohz_restart_sched_tick(void);
102extern void tick_nohz_update_jiffies(void);
103# else
104static inline void tick_nohz_stop_sched_tick(void) { }
105static inline void tick_nohz_restart_sched_tick(void) { }
106static inline void tick_nohz_update_jiffies(void) { }
107# endif /* !NO_HZ */
108
109#endif