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 #include <linux/context_tracking_state.h> 14 #include <linux/cpumask.h> 15 #include <linux/sched.h> 16 17 #ifdef CONFIG_GENERIC_CLOCKEVENTS 18 19 enum tick_device_mode { 20 TICKDEV_MODE_PERIODIC, 21 TICKDEV_MODE_ONESHOT, 22 }; 23 24 struct tick_device { 25 struct clock_event_device *evtdev; 26 enum tick_device_mode mode; 27 }; 28 29 enum tick_nohz_mode { 30 NOHZ_MODE_INACTIVE, 31 NOHZ_MODE_LOWRES, 32 NOHZ_MODE_HIGHRES, 33 }; 34 35 /** 36 * struct tick_sched - sched tick emulation and no idle tick control/stats 37 * @sched_timer: hrtimer to schedule the periodic tick in high 38 * resolution mode 39 * @last_tick: Store the last tick expiry time when the tick 40 * timer is modified for nohz sleeps. This is necessary 41 * to resume the tick timer operation in the timeline 42 * when the CPU returns from nohz sleep. 43 * @tick_stopped: Indicator that the idle tick has been stopped 44 * @idle_jiffies: jiffies at the entry to idle for idle time accounting 45 * @idle_calls: Total number of idle calls 46 * @idle_sleeps: Number of idle calls, where the sched tick was stopped 47 * @idle_entrytime: Time when the idle call was entered 48 * @idle_waketime: Time when the idle was interrupted 49 * @idle_exittime: Time when the idle state was left 50 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped 51 * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding 52 * @sleep_length: Duration of the current idle sleep 53 * @do_timer_lst: CPU was the last one doing do_timer before going idle 54 */ 55 struct tick_sched { 56 struct hrtimer sched_timer; 57 unsigned long check_clocks; 58 enum tick_nohz_mode nohz_mode; 59 ktime_t last_tick; 60 int inidle; 61 int tick_stopped; 62 unsigned long idle_jiffies; 63 unsigned long idle_calls; 64 unsigned long idle_sleeps; 65 int idle_active; 66 ktime_t idle_entrytime; 67 ktime_t idle_waketime; 68 ktime_t idle_exittime; 69 ktime_t idle_sleeptime; 70 ktime_t iowait_sleeptime; 71 ktime_t sleep_length; 72 unsigned long last_jiffies; 73 unsigned long next_jiffies; 74 ktime_t idle_expires; 75 int do_timer_last; 76 }; 77 78 extern void __init tick_init(void); 79 extern int tick_is_oneshot_available(void); 80 extern struct tick_device *tick_get_device(int cpu); 81 82 # ifdef CONFIG_HIGH_RES_TIMERS 83 extern int tick_init_highres(void); 84 extern int tick_program_event(ktime_t expires, int force); 85 extern void tick_setup_sched_timer(void); 86 # endif 87 88 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS 89 extern void tick_cancel_sched_timer(int cpu); 90 # else 91 static inline void tick_cancel_sched_timer(int cpu) { } 92 # endif 93 94 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 95 extern struct tick_device *tick_get_broadcast_device(void); 96 extern struct cpumask *tick_get_broadcast_mask(void); 97 98 # ifdef CONFIG_TICK_ONESHOT 99 extern struct cpumask *tick_get_broadcast_oneshot_mask(void); 100 # endif 101 102 # endif /* BROADCAST */ 103 104 # ifdef CONFIG_TICK_ONESHOT 105 extern void tick_clock_notify(void); 106 extern int tick_check_oneshot_change(int allow_nohz); 107 extern struct tick_sched *tick_get_tick_sched(int cpu); 108 extern void tick_irq_enter(void); 109 extern int tick_oneshot_mode_active(void); 110 # ifndef arch_needs_cpu 111 # define arch_needs_cpu() (0) 112 # endif 113 # else 114 static inline void tick_clock_notify(void) { } 115 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 116 static inline void tick_irq_enter(void) { } 117 static inline int tick_oneshot_mode_active(void) { return 0; } 118 # endif 119 120 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 121 static inline void tick_init(void) { } 122 static inline void tick_cancel_sched_timer(int cpu) { } 123 static inline void tick_clock_notify(void) { } 124 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 125 static inline void tick_irq_enter(void) { } 126 static inline int tick_oneshot_mode_active(void) { return 0; } 127 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 128 129 # ifdef CONFIG_NO_HZ_COMMON 130 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched); 131 132 static inline int tick_nohz_tick_stopped(void) 133 { 134 return __this_cpu_read(tick_cpu_sched.tick_stopped); 135 } 136 137 extern void tick_nohz_idle_enter(void); 138 extern void tick_nohz_idle_exit(void); 139 extern void tick_nohz_irq_exit(void); 140 extern ktime_t tick_nohz_get_sleep_length(void); 141 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 142 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 143 144 # else /* !CONFIG_NO_HZ_COMMON */ 145 static inline int tick_nohz_tick_stopped(void) 146 { 147 return 0; 148 } 149 150 static inline void tick_nohz_idle_enter(void) { } 151 static inline void tick_nohz_idle_exit(void) { } 152 153 static inline ktime_t tick_nohz_get_sleep_length(void) 154 { 155 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ }; 156 157 return len; 158 } 159 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 160 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 161 # endif /* !CONFIG_NO_HZ_COMMON */ 162 163 #ifdef CONFIG_NO_HZ_FULL 164 extern bool tick_nohz_full_running; 165 extern cpumask_var_t tick_nohz_full_mask; 166 extern cpumask_var_t housekeeping_mask; 167 168 static inline bool tick_nohz_full_enabled(void) 169 { 170 if (!context_tracking_is_enabled()) 171 return false; 172 173 return tick_nohz_full_running; 174 } 175 176 static inline bool tick_nohz_full_cpu(int cpu) 177 { 178 if (!tick_nohz_full_enabled()) 179 return false; 180 181 return cpumask_test_cpu(cpu, tick_nohz_full_mask); 182 } 183 184 extern void __tick_nohz_full_check(void); 185 extern void tick_nohz_full_kick(void); 186 extern void tick_nohz_full_kick_cpu(int cpu); 187 extern void tick_nohz_full_kick_all(void); 188 extern void __tick_nohz_task_switch(struct task_struct *tsk); 189 #else 190 static inline bool tick_nohz_full_enabled(void) { return false; } 191 static inline bool tick_nohz_full_cpu(int cpu) { return false; } 192 static inline void __tick_nohz_full_check(void) { } 193 static inline void tick_nohz_full_kick_cpu(int cpu) { } 194 static inline void tick_nohz_full_kick(void) { } 195 static inline void tick_nohz_full_kick_all(void) { } 196 static inline void __tick_nohz_task_switch(struct task_struct *tsk) { } 197 #endif 198 199 static inline bool is_housekeeping_cpu(int cpu) 200 { 201 #ifdef CONFIG_NO_HZ_FULL 202 if (tick_nohz_full_enabled()) 203 return cpumask_test_cpu(cpu, housekeeping_mask); 204 #endif 205 return true; 206 } 207 208 static inline void housekeeping_affine(struct task_struct *t) 209 { 210 #ifdef CONFIG_NO_HZ_FULL 211 if (tick_nohz_full_enabled()) 212 set_cpus_allowed_ptr(t, housekeeping_mask); 213 214 #endif 215 } 216 217 static inline void tick_nohz_full_check(void) 218 { 219 if (tick_nohz_full_enabled()) 220 __tick_nohz_full_check(); 221 } 222 223 static inline void tick_nohz_task_switch(struct task_struct *tsk) 224 { 225 if (tick_nohz_full_enabled()) 226 __tick_nohz_task_switch(tsk); 227 } 228 229 230 #endif 231