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