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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 * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding
46 * @sleep_length: Duration of the current idle sleep
47 * @do_timer_lst: CPU was the last one doing do_timer before going idle
48 */
49struct tick_sched {
50 struct hrtimer sched_timer;
51 unsigned long check_clocks;
52 enum tick_nohz_mode nohz_mode;
53 ktime_t idle_tick;
54 int inidle;
55 int tick_stopped;
56 unsigned long idle_jiffies;
57 unsigned long idle_calls;
58 unsigned long idle_sleeps;
59 int idle_active;
60 ktime_t idle_entrytime;
61 ktime_t idle_waketime;
62 ktime_t idle_exittime;
63 ktime_t idle_sleeptime;
64 ktime_t iowait_sleeptime;
65 ktime_t sleep_length;
66 unsigned long last_jiffies;
67 unsigned long next_jiffies;
68 ktime_t idle_expires;
69 int do_timer_last;
70};
71
72extern void __init tick_init(void);
73extern int tick_is_oneshot_available(void);
74extern struct tick_device *tick_get_device(int cpu);
75
76# ifdef CONFIG_HIGH_RES_TIMERS
77extern int tick_init_highres(void);
78extern int tick_program_event(ktime_t expires, int force);
79extern void tick_setup_sched_timer(void);
80# endif
81
82# if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
83extern void tick_cancel_sched_timer(int cpu);
84# else
85static inline void tick_cancel_sched_timer(int cpu) { }
86# endif
87
88# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
89extern struct tick_device *tick_get_broadcast_device(void);
90extern struct cpumask *tick_get_broadcast_mask(void);
91
92# ifdef CONFIG_TICK_ONESHOT
93extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
94# endif
95
96# endif /* BROADCAST */
97
98# ifdef CONFIG_TICK_ONESHOT
99extern void tick_clock_notify(void);
100extern int tick_check_oneshot_change(int allow_nohz);
101extern struct tick_sched *tick_get_tick_sched(int cpu);
102extern void tick_check_idle(int cpu);
103extern int tick_oneshot_mode_active(void);
104# ifndef arch_needs_cpu
105# define arch_needs_cpu(cpu) (0)
106# endif
107# else
108static inline void tick_clock_notify(void) { }
109static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
110static inline void tick_check_idle(int cpu) { }
111static inline int tick_oneshot_mode_active(void) { return 0; }
112# endif
113
114#else /* CONFIG_GENERIC_CLOCKEVENTS */
115static inline void tick_init(void) { }
116static inline void tick_cancel_sched_timer(int cpu) { }
117static inline void tick_clock_notify(void) { }
118static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
119static inline void tick_check_idle(int cpu) { }
120static inline int tick_oneshot_mode_active(void) { return 0; }
121#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
122
123# ifdef CONFIG_NO_HZ
124extern void tick_nohz_stop_sched_tick(int inidle);
125extern void tick_nohz_restart_sched_tick(void);
126extern ktime_t tick_nohz_get_sleep_length(void);
127extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
128extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
129# else
130static inline void tick_nohz_stop_sched_tick(int inidle) { }
131static inline void tick_nohz_restart_sched_tick(void) { }
132static inline ktime_t tick_nohz_get_sleep_length(void)
133{
134 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
135
136 return len;
137}
138static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
139static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
140# endif /* !NO_HZ */
141
142#endif