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 13 enum tick_device_mode { 14 TICKDEV_MODE_PERIODIC, 15 TICKDEV_MODE_ONESHOT, 16 }; 17 18 struct tick_device { 19 struct clock_event_device *evtdev; 20 enum tick_device_mode mode; 21 }; 22 23 enum 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 */ 47 struct 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 68 extern void __init tick_init(void); 69 extern int tick_is_oneshot_available(void); 70 extern struct tick_device *tick_get_device(int cpu); 71 72 # ifdef CONFIG_HIGH_RES_TIMERS 73 extern int tick_init_highres(void); 74 extern int tick_program_event(ktime_t expires, int force); 75 extern void tick_setup_sched_timer(void); 76 extern void tick_cancel_sched_timer(int cpu); 77 # else 78 static inline void tick_cancel_sched_timer(int cpu) { } 79 # endif /* HIGHRES */ 80 81 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 82 extern struct tick_device *tick_get_broadcast_device(void); 83 extern cpumask_t *tick_get_broadcast_mask(void); 84 85 # ifdef CONFIG_TICK_ONESHOT 86 extern cpumask_t *tick_get_broadcast_oneshot_mask(void); 87 # endif 88 89 # endif /* BROADCAST */ 90 91 # ifdef CONFIG_TICK_ONESHOT 92 extern void tick_clock_notify(void); 93 extern int tick_check_oneshot_change(int allow_nohz); 94 extern struct tick_sched *tick_get_tick_sched(int cpu); 95 # else 96 static inline void tick_clock_notify(void) { } 97 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 98 # endif 99 100 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 101 static inline void tick_init(void) { } 102 static inline void tick_cancel_sched_timer(int cpu) { } 103 static inline void tick_clock_notify(void) { } 104 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 105 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 106 107 # ifdef CONFIG_NO_HZ 108 extern void tick_nohz_stop_sched_tick(void); 109 extern void tick_nohz_restart_sched_tick(void); 110 extern void tick_nohz_update_jiffies(void); 111 extern ktime_t tick_nohz_get_sleep_length(void); 112 extern void tick_nohz_stop_idle(int cpu); 113 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 114 # else 115 static inline void tick_nohz_stop_sched_tick(void) { } 116 static inline void tick_nohz_restart_sched_tick(void) { } 117 static inline void tick_nohz_update_jiffies(void) { } 118 static inline ktime_t tick_nohz_get_sleep_length(void) 119 { 120 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ }; 121 122 return len; 123 } 124 static inline void tick_nohz_stop_idle(int cpu) { } 125 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return 0; } 126 # endif /* !NO_HZ */ 127 128 #endif 129