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