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
 16DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 17extern ktime_t tick_next_period;
 18extern int tick_do_timer_cpu __read_mostly;
 19
 20extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
 21extern void tick_handle_periodic(struct clock_event_device *dev);
 22extern void tick_check_new_device(struct clock_event_device *dev);
 23extern void tick_shutdown(unsigned int cpu);
 24extern void tick_suspend(void);
 25extern void tick_resume(void);
 26extern bool tick_check_replacement(struct clock_event_device *curdev,
 27				   struct clock_event_device *newdev);
 28extern void tick_install_replacement(struct clock_event_device *dev);
 29extern int tick_is_oneshot_available(void);
 30extern struct tick_device *tick_get_device(int cpu);
 31
 32extern int clockevents_tick_resume(struct clock_event_device *dev);
 33/* Check, if the device is functional or a dummy for broadcast */
 34static inline int tick_device_is_functional(struct clock_event_device *dev)
 35{
 36	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
 37}
 38
 39static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
 40{
 41	return dev->state_use_accessors;
 42}
 43
 44static 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
 50extern void clockevents_shutdown(struct clock_event_device *dev);
 51extern void clockevents_exchange_device(struct clock_event_device *old,
 52					struct clock_event_device *new);
 53extern void clockevents_switch_state(struct clock_event_device *dev,
 54				     enum clock_event_state state);
 55extern int clockevents_program_event(struct clock_event_device *dev,
 56				     ktime_t expires, bool force);
 57extern void clockevents_handle_noop(struct clock_event_device *dev);
 58extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
 59
 60/* Broadcasting support */
 61# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 62extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
 63extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
 64extern int tick_is_broadcast_device(struct clock_event_device *dev);
 65extern void tick_suspend_broadcast(void);
 66extern void tick_resume_broadcast(void);
 67extern bool tick_resume_check_broadcast(void);
 68extern void tick_broadcast_init(void);
 69extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
 70extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
 71extern struct tick_device *tick_get_broadcast_device(void);
 72extern struct cpumask *tick_get_broadcast_mask(void);
 73extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
 74# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
 75static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
 76static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
 77static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
 78static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
 79static inline void tick_suspend_broadcast(void) { }
 80static inline void tick_resume_broadcast(void) { }
 81static inline bool tick_resume_check_broadcast(void) { return false; }
 82static inline void tick_broadcast_init(void) { }
 83static 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 */
 86static 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: */
 93static inline void tick_suspend(void) { }
 94static inline void tick_resume(void) { }
 95#endif /* !GENERIC_CLOCKEVENTS */
 96
 97/* Oneshot related functions */
 98#ifdef CONFIG_TICK_ONESHOT
 99extern void tick_setup_oneshot(struct clock_event_device *newdev,
100			       void (*handler)(struct clock_event_device *),
101			       ktime_t nextevt);
102extern int tick_program_event(ktime_t expires, int force);
103extern void tick_oneshot_notify(void);
104extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
105extern void tick_resume_oneshot(void);
106static inline bool tick_oneshot_possible(void) { return true; }
107extern int tick_oneshot_mode_active(void);
108extern void tick_clock_notify(void);
109extern int tick_check_oneshot_change(int allow_nohz);
110extern int tick_init_highres(void);
111#else /* !CONFIG_TICK_ONESHOT: */
112static inline
113void tick_setup_oneshot(struct clock_event_device *newdev,
114			void (*handler)(struct clock_event_device *),
115			ktime_t nextevt) { BUG(); }
116static inline void tick_resume_oneshot(void) { BUG(); }
117static inline int tick_program_event(ktime_t expires, int force) { return 0; }
118static inline void tick_oneshot_notify(void) { }
119static inline bool tick_oneshot_possible(void) { return false; }
120static inline int tick_oneshot_mode_active(void) { return 0; }
121static inline void tick_clock_notify(void) { }
122static 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)
127extern void tick_broadcast_switch_to_oneshot(void);
128extern int tick_broadcast_oneshot_active(void);
129extern void tick_check_oneshot_broadcast_this_cpu(void);
130bool tick_broadcast_oneshot_available(void);
131extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
132#else /* !(BROADCAST && ONESHOT): */
133static inline void tick_broadcast_switch_to_oneshot(void) { }
134static inline int tick_broadcast_oneshot_active(void) { return 0; }
135static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
136static 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)
 
140extern void tick_broadcast_offline(unsigned int cpu);
141#else
 
142static inline void tick_broadcast_offline(unsigned int cpu) { }
143#endif
144
145/* NO_HZ_FULL internal */
146#ifdef CONFIG_NO_HZ_FULL
147extern void tick_nohz_init(void);
148# else
149static inline void tick_nohz_init(void) { }
150#endif
151
152#ifdef CONFIG_NO_HZ_COMMON
153extern unsigned long tick_nohz_active;
154extern void timers_update_nohz(void);
 
155# ifdef CONFIG_SMP
156extern struct static_key_false timers_migration_enabled;
 
 
 
 
 
 
 
157# endif
158#else /* CONFIG_NO_HZ_COMMON */
159static inline void timers_update_nohz(void) { }
160#define tick_nohz_active (0)
161#endif
162
163DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
164
165extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
 
166void 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
175void clock_was_set(unsigned int bases);
176void clock_was_set_delayed(void);
177
178void 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
200extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);

  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);