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 11struct 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 21DECLARE_PER_CPU(struct tick_device, tick_cpu_device); 22extern ktime_t tick_next_period; 23extern int tick_do_timer_cpu __read_mostly; 24 25extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast); 26extern void tick_handle_periodic(struct clock_event_device *dev); 27extern void tick_check_new_device(struct clock_event_device *dev); 28extern void tick_shutdown(unsigned int cpu); 29extern void tick_suspend(void); 30extern void tick_resume(void); 31extern bool tick_check_replacement(struct clock_event_device *curdev, 32 struct clock_event_device *newdev); 33extern void tick_install_replacement(struct clock_event_device *dev); 34extern int tick_is_oneshot_available(void); 35extern struct tick_device *tick_get_device(int cpu); 36 37extern int clockevents_tick_resume(struct clock_event_device *dev); 38/* Check, if the device is functional or a dummy for broadcast */ 39static inline int tick_device_is_functional(struct clock_event_device *dev) 40{ 41 return !(dev->features & CLOCK_EVT_FEAT_DUMMY); 42} 43 44static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev) 45{ 46 return dev->state_use_accessors; 47} 48 49static 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 55extern void clockevents_shutdown(struct clock_event_device *dev); 56extern void clockevents_exchange_device(struct clock_event_device *old, 57 struct clock_event_device *new); 58extern void clockevents_switch_state(struct clock_event_device *dev, 59 enum clock_event_state state); 60extern int clockevents_program_event(struct clock_event_device *dev, 61 ktime_t expires, bool force); 62extern void clockevents_handle_noop(struct clock_event_device *dev); 63extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq); 64 65/* Broadcasting support */ 66# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 67extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu); 68extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu); 69extern int tick_is_broadcast_device(struct clock_event_device *dev); 70extern void tick_suspend_broadcast(void); 71extern void tick_resume_broadcast(void); 72extern bool tick_resume_check_broadcast(void); 73extern void tick_broadcast_init(void); 74extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast); 75extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq); 76extern struct tick_device *tick_get_broadcast_device(void); 77extern struct cpumask *tick_get_broadcast_mask(void); 78extern const struct clock_event_device *tick_get_wakeup_device(int cpu); 79# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */ 80static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { } 81static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; } 82static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; } 83static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { } 84static inline void tick_suspend_broadcast(void) { } 85static inline void tick_resume_broadcast(void) { } 86static inline bool tick_resume_check_broadcast(void) { return false; } 87static inline void tick_broadcast_init(void) { } 88static 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 */ 91static 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: */ 98static inline void tick_suspend(void) { } 99static inline void tick_resume(void) { } 100#endif /* !GENERIC_CLOCKEVENTS */ 101 102/* Oneshot related functions */ 103#ifdef CONFIG_TICK_ONESHOT 104extern void tick_setup_oneshot(struct clock_event_device *newdev, 105 void (*handler)(struct clock_event_device *), 106 ktime_t nextevt); 107extern int tick_program_event(ktime_t expires, int force); 108extern void tick_oneshot_notify(void); 109extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *)); 110extern void tick_resume_oneshot(void); 111static inline bool tick_oneshot_possible(void) { return true; } 112extern int tick_oneshot_mode_active(void); 113extern void tick_clock_notify(void); 114extern int tick_check_oneshot_change(int allow_nohz); 115extern int tick_init_highres(void); 116#else /* !CONFIG_TICK_ONESHOT: */ 117static inline 118void tick_setup_oneshot(struct clock_event_device *newdev, 119 void (*handler)(struct clock_event_device *), 120 ktime_t nextevt) { BUG(); } 121static inline void tick_resume_oneshot(void) { BUG(); } 122static inline int tick_program_event(ktime_t expires, int force) { return 0; } 123static inline void tick_oneshot_notify(void) { } 124static inline bool tick_oneshot_possible(void) { return false; } 125static inline int tick_oneshot_mode_active(void) { return 0; } 126static inline void tick_clock_notify(void) { } 127static 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) 132extern void tick_broadcast_switch_to_oneshot(void); 133extern int tick_broadcast_oneshot_active(void); 134extern void tick_check_oneshot_broadcast_this_cpu(void); 135bool tick_broadcast_oneshot_available(void); 136extern struct cpumask *tick_get_broadcast_oneshot_mask(void); 137#else /* !(BROADCAST && ONESHOT): */ 138static inline void tick_broadcast_switch_to_oneshot(void) { } 139static inline int tick_broadcast_oneshot_active(void) { return 0; } 140static inline void tick_check_oneshot_broadcast_this_cpu(void) { } 141static 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) 145extern void tick_offline_cpu(unsigned int cpu); 146extern void tick_broadcast_offline(unsigned int cpu); 147#else 148static inline void tick_offline_cpu(unsigned int cpu) { } 149static inline void tick_broadcast_offline(unsigned int cpu) { } 150#endif 151 152/* NO_HZ_FULL internal */ 153#ifdef CONFIG_NO_HZ_FULL 154extern void tick_nohz_init(void); 155# else 156static inline void tick_nohz_init(void) { } 157#endif 158 159#ifdef CONFIG_NO_HZ_COMMON 160extern unsigned long tick_nohz_active; 161extern void timers_update_nohz(void); 162extern u64 get_jiffies_update(unsigned long *basej); 163# ifdef CONFIG_SMP 164extern struct static_key_false timers_migration_enabled; 165extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem, 166 struct timer_events *tevt, 167 unsigned int cpu); 168extern void timer_lock_remote_bases(unsigned int cpu); 169extern void timer_unlock_remote_bases(unsigned int cpu); 170extern bool timer_base_is_idle(void); 171extern void timer_expire_remote(unsigned int cpu); 172# endif 173#else /* CONFIG_NO_HZ_COMMON */ 174static inline void timers_update_nohz(void) { } 175#define tick_nohz_active (0) 176#endif 177 178DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases); 179 180extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem); 181u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle); 182void 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 191void clock_was_set(unsigned int bases); 192void clock_was_set_delayed(void); 193 194void 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 216extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); 217