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