1 /* linux/include/linux/tick.h
3 * This file contains the structure definitions for tick related functions
9 #include <linux/clockchips.h>
11 #ifdef CONFIG_GENERIC_CLOCKEVENTS
13 enum tick_device_mode {
14 TICKDEV_MODE_PERIODIC,
19 struct clock_event_device *evtdev;
20 enum tick_device_mode mode;
30 * struct tick_sched - sched tick emulation and no idle tick control/stats
31 * @sched_timer: hrtimer to schedule the periodic tick in high
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 * @do_timer_lst: CPU was the last one doing do_timer before going idle
49 struct hrtimer sched_timer;
50 unsigned long check_clocks;
51 enum tick_nohz_mode nohz_mode;
55 unsigned long idle_jiffies;
56 unsigned long idle_calls;
57 unsigned long idle_sleeps;
59 ktime_t idle_entrytime;
60 ktime_t idle_waketime;
61 ktime_t idle_exittime;
62 ktime_t idle_sleeptime;
64 unsigned long last_jiffies;
65 unsigned long next_jiffies;
70 extern void __init tick_init(void);
71 extern int tick_is_oneshot_available(void);
72 extern struct tick_device *tick_get_device(int cpu);
74 # ifdef CONFIG_HIGH_RES_TIMERS
75 extern int tick_init_highres(void);
76 extern int tick_program_event(ktime_t expires, int force);
77 extern void tick_setup_sched_timer(void);
80 # if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
81 extern void tick_cancel_sched_timer(int cpu);
83 static inline void tick_cancel_sched_timer(int cpu) { }
86 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
87 extern struct tick_device *tick_get_broadcast_device(void);
88 extern struct cpumask *tick_get_broadcast_mask(void);
90 # ifdef CONFIG_TICK_ONESHOT
91 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
94 # endif /* BROADCAST */
96 # ifdef CONFIG_TICK_ONESHOT
97 extern void tick_clock_notify(void);
98 extern int tick_check_oneshot_change(int allow_nohz);
99 extern struct tick_sched *tick_get_tick_sched(int cpu);
100 extern void tick_check_idle(int cpu);
101 extern int tick_oneshot_mode_active(void);
102 # ifndef arch_needs_cpu
103 # define arch_needs_cpu(cpu) (0)
106 static inline void tick_clock_notify(void) { }
107 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
108 static inline void tick_check_idle(int cpu) { }
109 static inline int tick_oneshot_mode_active(void) { return 0; }
112 #else /* CONFIG_GENERIC_CLOCKEVENTS */
113 static inline void tick_init(void) { }
114 static inline void tick_cancel_sched_timer(int cpu) { }
115 static inline void tick_clock_notify(void) { }
116 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
117 static inline void tick_check_idle(int cpu) { }
118 static inline int tick_oneshot_mode_active(void) { return 0; }
119 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
122 extern void tick_nohz_stop_sched_tick(int inidle);
123 extern void tick_nohz_restart_sched_tick(void);
124 extern ktime_t tick_nohz_get_sleep_length(void);
125 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
127 static inline void tick_nohz_stop_sched_tick(int inidle) { }
128 static inline void tick_nohz_restart_sched_tick(void) { }
129 static inline ktime_t tick_nohz_get_sleep_length(void)
131 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
135 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }