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 #include <linux/irqflags.h> 11 #include <linux/percpu.h> 12 #include <linux/hrtimer.h> 13 14 #ifdef CONFIG_GENERIC_CLOCKEVENTS 15 16 enum tick_device_mode { 17 TICKDEV_MODE_PERIODIC, 18 TICKDEV_MODE_ONESHOT, 19 }; 20 21 struct tick_device { 22 struct clock_event_device *evtdev; 23 enum tick_device_mode mode; 24 }; 25 26 enum tick_nohz_mode { 27 NOHZ_MODE_INACTIVE, 28 NOHZ_MODE_LOWRES, 29 NOHZ_MODE_HIGHRES, 30 }; 31 32 /** 33 * struct tick_sched - sched tick emulation and no idle tick control/stats 34 * @sched_timer: hrtimer to schedule the periodic tick in high 35 * resolution mode 36 * @last_tick: Store the last tick expiry time when the tick 37 * timer is modified for nohz sleeps. This is necessary 38 * to resume the tick timer operation in the timeline 39 * when the CPU returns from nohz sleep. 40 * @tick_stopped: Indicator that the idle tick has been stopped 41 * @idle_jiffies: jiffies at the entry to idle for idle time accounting 42 * @idle_calls: Total number of idle calls 43 * @idle_sleeps: Number of idle calls, where the sched tick was stopped 44 * @idle_entrytime: Time when the idle call was entered 45 * @idle_waketime: Time when the idle was interrupted 46 * @idle_exittime: Time when the idle state was left 47 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped 48 * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding 49 * @sleep_length: Duration of the current idle sleep 50 * @do_timer_lst: CPU was the last one doing do_timer before going idle 51 */ 52 struct tick_sched { 53 struct hrtimer sched_timer; 54 unsigned long check_clocks; 55 enum tick_nohz_mode nohz_mode; 56 ktime_t last_tick; 57 int inidle; 58 int tick_stopped; 59 unsigned long idle_jiffies; 60 unsigned long idle_calls; 61 unsigned long idle_sleeps; 62 int idle_active; 63 ktime_t idle_entrytime; 64 ktime_t idle_waketime; 65 ktime_t idle_exittime; 66 ktime_t idle_sleeptime; 67 ktime_t iowait_sleeptime; 68 ktime_t sleep_length; 69 unsigned long last_jiffies; 70 unsigned long next_jiffies; 71 ktime_t idle_expires; 72 int do_timer_last; 73 }; 74 75 extern void __init tick_init(void); 76 extern int tick_is_oneshot_available(void); 77 extern struct tick_device *tick_get_device(int cpu); 78 79 # ifdef CONFIG_HIGH_RES_TIMERS 80 extern int tick_init_highres(void); 81 extern int tick_program_event(ktime_t expires, int force); 82 extern void tick_setup_sched_timer(void); 83 # endif 84 85 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS 86 extern void tick_cancel_sched_timer(int cpu); 87 # else 88 static inline void tick_cancel_sched_timer(int cpu) { } 89 # endif 90 91 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 92 extern struct tick_device *tick_get_broadcast_device(void); 93 extern struct cpumask *tick_get_broadcast_mask(void); 94 95 # ifdef CONFIG_TICK_ONESHOT 96 extern struct cpumask *tick_get_broadcast_oneshot_mask(void); 97 # endif 98 99 # endif /* BROADCAST */ 100 101 # ifdef CONFIG_TICK_ONESHOT 102 extern void tick_clock_notify(void); 103 extern int tick_check_oneshot_change(int allow_nohz); 104 extern struct tick_sched *tick_get_tick_sched(int cpu); 105 extern void tick_check_idle(int cpu); 106 extern int tick_oneshot_mode_active(void); 107 # ifndef arch_needs_cpu 108 # define arch_needs_cpu(cpu) (0) 109 # endif 110 # else 111 static inline void tick_clock_notify(void) { } 112 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 113 static inline void tick_check_idle(int cpu) { } 114 static inline int tick_oneshot_mode_active(void) { return 0; } 115 # endif 116 117 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 118 static inline void tick_init(void) { } 119 static inline void tick_cancel_sched_timer(int cpu) { } 120 static inline void tick_clock_notify(void) { } 121 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 122 static inline void tick_check_idle(int cpu) { } 123 static inline int tick_oneshot_mode_active(void) { return 0; } 124 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 125 126 # ifdef CONFIG_NO_HZ_COMMON 127 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched); 128 129 static inline int tick_nohz_tick_stopped(void) 130 { 131 return __this_cpu_read(tick_cpu_sched.tick_stopped); 132 } 133 134 extern void tick_nohz_idle_enter(void); 135 extern void tick_nohz_idle_exit(void); 136 extern void tick_nohz_irq_exit(void); 137 extern ktime_t tick_nohz_get_sleep_length(void); 138 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 139 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 140 141 # else /* !CONFIG_NO_HZ_COMMON */ 142 static inline int tick_nohz_tick_stopped(void) 143 { 144 return 0; 145 } 146 147 static inline void tick_nohz_idle_enter(void) { } 148 static inline void tick_nohz_idle_exit(void) { } 149 150 static inline ktime_t tick_nohz_get_sleep_length(void) 151 { 152 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ }; 153 154 return len; 155 } 156 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 157 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 158 # endif /* !CONFIG_NO_HZ_COMMON */ 159 160 #ifdef CONFIG_NO_HZ_FULL 161 extern void tick_nohz_init(void); 162 extern int tick_nohz_full_cpu(int cpu); 163 extern void tick_nohz_full_check(void); 164 extern void tick_nohz_full_kick(void); 165 extern void tick_nohz_full_kick_all(void); 166 extern void tick_nohz_task_switch(struct task_struct *tsk); 167 #else 168 static inline void tick_nohz_init(void) { } 169 static inline int tick_nohz_full_cpu(int cpu) { return 0; } 170 static inline void tick_nohz_full_check(void) { } 171 static inline void tick_nohz_full_kick(void) { } 172 static inline void tick_nohz_full_kick_all(void) { } 173 static inline void tick_nohz_task_switch(struct task_struct *tsk) { } 174 #endif 175 176 177 #endif 178