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 inidle; 53 int tick_stopped; 54 unsigned long idle_jiffies; 55 unsigned long idle_calls; 56 unsigned long idle_sleeps; 57 int idle_active; 58 ktime_t idle_entrytime; 59 ktime_t idle_waketime; 60 ktime_t idle_exittime; 61 ktime_t idle_sleeptime; 62 ktime_t idle_lastupdate; 63 ktime_t sleep_length; 64 unsigned long last_jiffies; 65 unsigned long next_jiffies; 66 ktime_t idle_expires; 67 }; 68 69 extern void __init tick_init(void); 70 extern int tick_is_oneshot_available(void); 71 extern struct tick_device *tick_get_device(int cpu); 72 73 # ifdef CONFIG_HIGH_RES_TIMERS 74 extern int tick_init_highres(void); 75 extern int tick_program_event(ktime_t expires, int force); 76 extern void tick_setup_sched_timer(void); 77 # endif 78 79 # if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS 80 extern void tick_cancel_sched_timer(int cpu); 81 # else 82 static inline void tick_cancel_sched_timer(int cpu) { } 83 # endif 84 85 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 86 extern struct tick_device *tick_get_broadcast_device(void); 87 extern cpumask_t *tick_get_broadcast_mask(void); 88 89 # ifdef CONFIG_TICK_ONESHOT 90 extern cpumask_t *tick_get_broadcast_oneshot_mask(void); 91 # endif 92 93 # endif /* BROADCAST */ 94 95 # ifdef CONFIG_TICK_ONESHOT 96 extern void tick_clock_notify(void); 97 extern int tick_check_oneshot_change(int allow_nohz); 98 extern struct tick_sched *tick_get_tick_sched(int cpu); 99 extern void tick_check_idle(int cpu); 100 # else 101 static inline void tick_clock_notify(void) { } 102 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 103 static inline void tick_check_idle(int cpu) { } 104 # endif 105 106 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 107 static inline void tick_init(void) { } 108 static inline void tick_cancel_sched_timer(int cpu) { } 109 static inline void tick_clock_notify(void) { } 110 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 111 static inline void tick_check_idle(int cpu) { } 112 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 113 114 # ifdef CONFIG_NO_HZ 115 extern void tick_nohz_stop_sched_tick(int inidle); 116 extern void tick_nohz_restart_sched_tick(void); 117 extern ktime_t tick_nohz_get_sleep_length(void); 118 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 119 # else 120 static inline void tick_nohz_stop_sched_tick(int inidle) { } 121 static inline void tick_nohz_restart_sched_tick(void) { } 122 static inline ktime_t tick_nohz_get_sleep_length(void) 123 { 124 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ }; 125 126 return len; 127 } 128 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 129 # endif /* !NO_HZ */ 130 131 #endif 132