1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * tick internal variable and functions used by low/high res code 4 */ 5 #include <linux/hrtimer.h> 6 #include <linux/tick.h> 7 8 #include "timekeeping.h" 9 #include "tick-sched.h" 10 11 struct timer_events { 12 u64 local; 13 u64 global; 14 }; 15 16 #ifdef CONFIG_GENERIC_CLOCKEVENTS 17 18 # define TICK_DO_TIMER_NONE -1 19 # define TICK_DO_TIMER_BOOT -2 20 21 DECLARE_PER_CPU(struct tick_device, tick_cpu_device); 22 extern ktime_t tick_next_period; 23 extern int tick_do_timer_cpu __read_mostly; 24 25 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast); 26 extern void tick_handle_periodic(struct clock_event_device *dev); 27 extern void tick_check_new_device(struct clock_event_device *dev); 28 extern void tick_shutdown(unsigned int cpu); 29 extern void tick_suspend(void); 30 extern void tick_resume(void); 31 extern bool tick_check_replacement(struct clock_event_device *curdev, 32 struct clock_event_device *newdev); 33 extern void tick_install_replacement(struct clock_event_device *dev); 34 extern int tick_is_oneshot_available(void); 35 extern struct tick_device *tick_get_device(int cpu); 36 37 extern int clockevents_tick_resume(struct clock_event_device *dev); 38 /* Check, if the device is functional or a dummy for broadcast */ 39 static inline int tick_device_is_functional(struct clock_event_device *dev) 40 { 41 return !(dev->features & CLOCK_EVT_FEAT_DUMMY); 42 } 43 44 static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev) 45 { 46 return dev->state_use_accessors; 47 } 48 49 static inline void clockevent_set_state(struct clock_event_device *dev, 50 enum clock_event_state state) 51 { 52 dev->state_use_accessors = state; 53 } 54 55 extern void clockevents_shutdown(struct clock_event_device *dev); 56 extern void clockevents_exchange_device(struct clock_event_device *old, 57 struct clock_event_device *new); 58 extern void clockevents_switch_state(struct clock_event_device *dev, 59 enum clock_event_state state); 60 extern int clockevents_program_event(struct clock_event_device *dev, 61 ktime_t expires, bool force); 62 extern void clockevents_handle_noop(struct clock_event_device *dev); 63 extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq); 64 65 /* Broadcasting support */ 66 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 67 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu); 68 extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu); 69 extern int tick_is_broadcast_device(struct clock_event_device *dev); 70 extern void tick_suspend_broadcast(void); 71 extern void tick_resume_broadcast(void); 72 extern bool tick_resume_check_broadcast(void); 73 extern void tick_broadcast_init(void); 74 extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast); 75 extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq); 76 extern struct tick_device *tick_get_broadcast_device(void); 77 extern struct cpumask *tick_get_broadcast_mask(void); 78 extern const struct clock_event_device *tick_get_wakeup_device(int cpu); 79 # else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */ 80 static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { } 81 static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; } 82 static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; } 83 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { } 84 static inline void tick_suspend_broadcast(void) { } 85 static inline void tick_resume_broadcast(void) { } 86 static inline bool tick_resume_check_broadcast(void) { return false; } 87 static inline void tick_broadcast_init(void) { } 88 static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; } 89 90 /* Set the periodic handler in non broadcast mode */ 91 static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast) 92 { 93 dev->event_handler = tick_handle_periodic; 94 } 95 # endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */ 96 97 #else /* !GENERIC_CLOCKEVENTS: */ 98 static inline void tick_suspend(void) { } 99 static inline void tick_resume(void) { } 100 #endif /* !GENERIC_CLOCKEVENTS */ 101 102 /* Oneshot related functions */ 103 #ifdef CONFIG_TICK_ONESHOT 104 extern void tick_setup_oneshot(struct clock_event_device *newdev, 105 void (*handler)(struct clock_event_device *), 106 ktime_t nextevt); 107 extern int tick_program_event(ktime_t expires, int force); 108 extern void tick_oneshot_notify(void); 109 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *)); 110 extern void tick_resume_oneshot(void); 111 static inline bool tick_oneshot_possible(void) { return true; } 112 extern int tick_oneshot_mode_active(void); 113 extern void tick_clock_notify(void); 114 extern int tick_check_oneshot_change(int allow_nohz); 115 extern int tick_init_highres(void); 116 #else /* !CONFIG_TICK_ONESHOT: */ 117 static inline 118 void tick_setup_oneshot(struct clock_event_device *newdev, 119 void (*handler)(struct clock_event_device *), 120 ktime_t nextevt) { BUG(); } 121 static inline void tick_resume_oneshot(void) { BUG(); } 122 static inline int tick_program_event(ktime_t expires, int force) { return 0; } 123 static inline void tick_oneshot_notify(void) { } 124 static inline bool tick_oneshot_possible(void) { return false; } 125 static inline int tick_oneshot_mode_active(void) { return 0; } 126 static inline void tick_clock_notify(void) { } 127 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 128 #endif /* !CONFIG_TICK_ONESHOT */ 129 130 /* Functions related to oneshot broadcasting */ 131 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 132 extern void tick_broadcast_switch_to_oneshot(void); 133 extern int tick_broadcast_oneshot_active(void); 134 extern void tick_check_oneshot_broadcast_this_cpu(void); 135 bool tick_broadcast_oneshot_available(void); 136 extern struct cpumask *tick_get_broadcast_oneshot_mask(void); 137 #else /* !(BROADCAST && ONESHOT): */ 138 static inline void tick_broadcast_switch_to_oneshot(void) { } 139 static inline int tick_broadcast_oneshot_active(void) { return 0; } 140 static inline void tick_check_oneshot_broadcast_this_cpu(void) { } 141 static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); } 142 #endif /* !(BROADCAST && ONESHOT) */ 143 144 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU) 145 extern void tick_offline_cpu(unsigned int cpu); 146 extern void tick_broadcast_offline(unsigned int cpu); 147 #else 148 static inline void tick_offline_cpu(unsigned int cpu) { } 149 static inline void tick_broadcast_offline(unsigned int cpu) { } 150 #endif 151 152 /* NO_HZ_FULL internal */ 153 #ifdef CONFIG_NO_HZ_FULL 154 extern void tick_nohz_init(void); 155 # else 156 static inline void tick_nohz_init(void) { } 157 #endif 158 159 #ifdef CONFIG_NO_HZ_COMMON 160 extern unsigned long tick_nohz_active; 161 extern void timers_update_nohz(void); 162 extern u64 get_jiffies_update(unsigned long *basej); 163 # ifdef CONFIG_SMP 164 extern struct static_key_false timers_migration_enabled; 165 extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem, 166 struct timer_events *tevt, 167 unsigned int cpu); 168 extern void timer_lock_remote_bases(unsigned int cpu); 169 extern void timer_unlock_remote_bases(unsigned int cpu); 170 extern bool timer_base_is_idle(void); 171 extern void timer_expire_remote(unsigned int cpu); 172 # endif 173 #else /* CONFIG_NO_HZ_COMMON */ 174 static inline void timers_update_nohz(void) { } 175 #define tick_nohz_active (0) 176 #endif 177 178 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases); 179 180 extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem); 181 u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle); 182 void timer_clear_idle(void); 183 184 #define CLOCK_SET_WALL \ 185 (BIT(HRTIMER_BASE_REALTIME) | BIT(HRTIMER_BASE_REALTIME_SOFT) | \ 186 BIT(HRTIMER_BASE_TAI) | BIT(HRTIMER_BASE_TAI_SOFT)) 187 188 #define CLOCK_SET_BOOT \ 189 (BIT(HRTIMER_BASE_BOOTTIME) | BIT(HRTIMER_BASE_BOOTTIME_SOFT)) 190 191 void clock_was_set(unsigned int bases); 192 void clock_was_set_delayed(void); 193 194 void hrtimers_resume_local(void); 195 196 /* Since jiffies uses a simple TICK_NSEC multiplier 197 * conversion, the .shift value could be zero. However 198 * this would make NTP adjustments impossible as they are 199 * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to 200 * shift both the nominator and denominator the same 201 * amount, and give ntp adjustments in units of 1/2^8 202 * 203 * The value 8 is somewhat carefully chosen, as anything 204 * larger can result in overflows. TICK_NSEC grows as HZ 205 * shrinks, so values greater than 8 overflow 32bits when 206 * HZ=100. 207 */ 208 #if HZ < 34 209 #define JIFFIES_SHIFT 6 210 #elif HZ < 67 211 #define JIFFIES_SHIFT 7 212 #else 213 #define JIFFIES_SHIFT 8 214 #endif 215 216 extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); 217