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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_waketime: Time when the idle was interrupted
43 * @idle_exittime: Time when the idle state was left
44 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
45 * @sleep_length: Duration of the current idle sleep
46 */
47struct tick_sched {
48 struct hrtimer sched_timer;
49 unsigned long check_clocks;
50 enum tick_nohz_mode nohz_mode;
51 ktime_t idle_tick;
52 int tick_stopped;
53 unsigned long idle_jiffies;
54 unsigned long idle_calls;
55 unsigned long idle_sleeps;
56 int idle_active;
57 ktime_t idle_entrytime;
58 ktime_t idle_waketime;
59 ktime_t idle_exittime;
60 ktime_t idle_sleeptime;
61 ktime_t idle_lastupdate;
62 ktime_t sleep_length;
63 unsigned long last_jiffies;
64 unsigned long next_jiffies;
65 ktime_t idle_expires;
66};
67
68extern void __init tick_init(void);
69extern int tick_is_oneshot_available(void);
70extern struct tick_device *tick_get_device(int cpu);
71
72# ifdef CONFIG_HIGH_RES_TIMERS
73extern int tick_init_highres(void);
74extern int tick_program_event(ktime_t expires, int force);
75extern void tick_setup_sched_timer(void);
76extern void tick_cancel_sched_timer(int cpu);
77# else
78static inline void tick_cancel_sched_timer(int cpu) { }
79# endif /* HIGHRES */
80
81# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
82extern struct tick_device *tick_get_broadcast_device(void);
83extern cpumask_t *tick_get_broadcast_mask(void);
84
85# ifdef CONFIG_TICK_ONESHOT
86extern cpumask_t *tick_get_broadcast_oneshot_mask(void);
87# endif
88
89# endif /* BROADCAST */
90
91# ifdef CONFIG_TICK_ONESHOT
92extern void tick_clock_notify(void);
93extern int tick_check_oneshot_change(int allow_nohz);
94extern struct tick_sched *tick_get_tick_sched(int cpu);
95# else
96static inline void tick_clock_notify(void) { }
97static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
98# endif
99
100#else /* CONFIG_GENERIC_CLOCKEVENTS */
101static inline void tick_init(void) { }
102static inline void tick_cancel_sched_timer(int cpu) { }
103static inline void tick_clock_notify(void) { }
104static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
105#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
106
107# ifdef CONFIG_NO_HZ
108extern void tick_nohz_stop_sched_tick(void);
109extern void tick_nohz_restart_sched_tick(void);
110extern void tick_nohz_update_jiffies(void);
111extern ktime_t tick_nohz_get_sleep_length(void);
112extern void tick_nohz_stop_idle(int cpu);
113extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
114# else
115static inline void tick_nohz_stop_sched_tick(void) { }
116static inline void tick_nohz_restart_sched_tick(void) { }
117static inline void tick_nohz_update_jiffies(void) { }
118static inline ktime_t tick_nohz_get_sleep_length(void)
119{
120 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
121
122 return len;
123}
124static inline void tick_nohz_stop_idle(int cpu) { }
125static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return 0; }
126# endif /* !NO_HZ */
127
128#endif