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