kernel/time/tick-internal.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * tick internal variable and functions used by low/high res code
  */
 #include <linux/hrtimer.h>
 #include <linux/tick.h>

 #include "timekeeping.h"
 #include "tick-sched.h"

 struct timer_events {
 	u64	local;
 	u64	global;
 };

 #ifdef CONFIG_GENERIC_CLOCKEVENTS

 # define TICK_DO_TIMER_NONE	-1
 # define TICK_DO_TIMER_BOOT	-2

 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 extern ktime_t tick_next_period;
 extern int tick_do_timer_cpu __read_mostly;

 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
 extern void tick_handle_periodic(struct clock_event_device *dev);
 extern void tick_check_new_device(struct clock_event_device *dev);
 extern void tick_shutdown(unsigned int cpu);
 extern void tick_suspend(void);
 extern void tick_resume(void);
 extern bool tick_check_replacement(struct clock_event_device *curdev,
 				   struct clock_event_device *newdev);
 extern void tick_install_replacement(struct clock_event_device *dev);
 extern int tick_is_oneshot_available(void);
 extern struct tick_device *tick_get_device(int cpu);

 extern int clockevents_tick_resume(struct clock_event_device *dev);
 /* Check, if the device is functional or a dummy for broadcast */
 static inline int tick_device_is_functional(struct clock_event_device *dev)
 {
 	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
 }

 static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
 {
 	return dev->state_use_accessors;
 }

 static inline void clockevent_set_state(struct clock_event_device *dev,
 					enum clock_event_state state)
 {
 	dev->state_use_accessors = state;
 }

 extern void clockevents_shutdown(struct clock_event_device *dev);
 extern void clockevents_exchange_device(struct clock_event_device *old,
 					struct clock_event_device *new);
 extern void clockevents_switch_state(struct clock_event_device *dev,
 				     enum clock_event_state state);
 extern int clockevents_program_event(struct clock_event_device *dev,
 				     ktime_t expires, bool force);
 extern void clockevents_handle_noop(struct clock_event_device *dev);
 extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);

 /* Broadcasting support */
 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
 extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
 extern int tick_is_broadcast_device(struct clock_event_device *dev);
 extern void tick_suspend_broadcast(void);
 extern void tick_resume_broadcast(void);
 extern bool tick_resume_check_broadcast(void);
 extern void tick_broadcast_init(void);
 extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
 extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
 extern struct tick_device *tick_get_broadcast_device(void);
 extern struct cpumask *tick_get_broadcast_mask(void);
 extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
 # else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
 static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
 static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
 static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
 static inline void tick_suspend_broadcast(void) { }
 static inline void tick_resume_broadcast(void) { }
 static inline bool tick_resume_check_broadcast(void) { return false; }
 static inline void tick_broadcast_init(void) { }
 static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; }

 /* Set the periodic handler in non broadcast mode */
 static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
 {
 	dev->event_handler = tick_handle_periodic;
 }
 # endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */

 #else /* !GENERIC_CLOCKEVENTS: */
 static inline void tick_suspend(void) { }
 static inline void tick_resume(void) { }
 #endif /* !GENERIC_CLOCKEVENTS */

 /* Oneshot related functions */
 #ifdef CONFIG_TICK_ONESHOT
 extern void tick_setup_oneshot(struct clock_event_device *newdev,
 			       void (*handler)(struct clock_event_device *),
 			       ktime_t nextevt);
 extern int tick_program_event(ktime_t expires, int force);
 extern void tick_oneshot_notify(void);
 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
 extern void tick_resume_oneshot(void);
 static inline bool tick_oneshot_possible(void) { return true; }
 extern int tick_oneshot_mode_active(void);
 extern void tick_clock_notify(void);
 extern int tick_check_oneshot_change(int allow_nohz);
 extern int tick_init_highres(void);
 #else /* !CONFIG_TICK_ONESHOT: */
 static inline
 void tick_setup_oneshot(struct clock_event_device *newdev,
 			void (*handler)(struct clock_event_device *),
 			ktime_t nextevt) { BUG(); }
 static inline void tick_resume_oneshot(void) { BUG(); }
 static inline int tick_program_event(ktime_t expires, int force) { return 0; }
 static inline void tick_oneshot_notify(void) { }
 static inline bool tick_oneshot_possible(void) { return false; }
 static inline int tick_oneshot_mode_active(void) { return 0; }
 static inline void tick_clock_notify(void) { }
 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 #endif /* !CONFIG_TICK_ONESHOT */

 /* Functions related to oneshot broadcasting */
 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 extern void tick_broadcast_switch_to_oneshot(void);
 extern int tick_broadcast_oneshot_active(void);
 extern void tick_check_oneshot_broadcast_this_cpu(void);
 bool tick_broadcast_oneshot_available(void);
 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
 #else /* !(BROADCAST && ONESHOT): */
 static inline void tick_broadcast_switch_to_oneshot(void) { }
 static inline int tick_broadcast_oneshot_active(void) { return 0; }
 static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
 static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
 #endif /* !(BROADCAST && ONESHOT) */

 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
 extern void tick_offline_cpu(unsigned int cpu);
 extern void tick_broadcast_offline(unsigned int cpu);
 #else
 static inline void tick_offline_cpu(unsigned int cpu) { }
 static inline void tick_broadcast_offline(unsigned int cpu) { }
 #endif

 /* NO_HZ_FULL internal */
 #ifdef CONFIG_NO_HZ_FULL
 extern void tick_nohz_init(void);
 # else
 static inline void tick_nohz_init(void) { }
 #endif

 #ifdef CONFIG_NO_HZ_COMMON
 extern unsigned long tick_nohz_active;
 extern void timers_update_nohz(void);
 extern u64 get_jiffies_update(unsigned long *basej);
 # ifdef CONFIG_SMP
 extern struct static_key_false timers_migration_enabled;
 extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
 					      struct timer_events *tevt,
 					      unsigned int cpu);
 extern void timer_lock_remote_bases(unsigned int cpu);
 extern void timer_unlock_remote_bases(unsigned int cpu);
 extern bool timer_base_is_idle(void);
 extern void timer_expire_remote(unsigned int cpu);
 # endif
 #else /* CONFIG_NO_HZ_COMMON */
 static inline void timers_update_nohz(void) { }
 #define tick_nohz_active (0)
 #endif

 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);

 extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
 u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
 void timer_clear_idle(void);

 #define CLOCK_SET_WALL							\
 	(BIT(HRTIMER_BASE_REALTIME) | BIT(HRTIMER_BASE_REALTIME_SOFT) |	\
 	 BIT(HRTIMER_BASE_TAI) | BIT(HRTIMER_BASE_TAI_SOFT))

 #define CLOCK_SET_BOOT							\
 	(BIT(HRTIMER_BASE_BOOTTIME) | BIT(HRTIMER_BASE_BOOTTIME_SOFT))

 void clock_was_set(unsigned int bases);
 void clock_was_set_delayed(void);

 void hrtimers_resume_local(void);

 /* Since jiffies uses a simple TICK_NSEC multiplier
  * conversion, the .shift value could be zero. However
  * this would make NTP adjustments impossible as they are
  * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
  * shift both the nominator and denominator the same
  * amount, and give ntp adjustments in units of 1/2^8
  *
  * The value 8 is somewhat carefully chosen, as anything
  * larger can result in overflows. TICK_NSEC grows as HZ
  * shrinks, so values greater than 8 overflow 32bits when
  * HZ=100.
  */
 #if HZ < 34
 #define JIFFIES_SHIFT	6
 #elif HZ < 67
 #define JIFFIES_SHIFT	7
 #else
 #define JIFFIES_SHIFT	8
 #endif

 extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* tick internal variable and functions used by low/high res code
	*/
	#include <linux/hrtimer.h>
	#include <linux/tick.h>

	#include "timekeeping.h"
	#include "tick-sched.h"

	struct timer_events {
	u64 local;
	u64 global;
	};

	#ifdef CONFIG_GENERIC_CLOCKEVENTS

	# define TICK_DO_TIMER_NONE -1
	# define TICK_DO_TIMER_BOOT -2

	DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
	extern ktime_t tick_next_period;
	extern int tick_do_timer_cpu __read_mostly;

	extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
	extern void tick_handle_periodic(struct clock_event_device *dev);
	extern void tick_check_new_device(struct clock_event_device *dev);
	extern void tick_shutdown(unsigned int cpu);
	extern void tick_suspend(void);
	extern void tick_resume(void);
	extern bool tick_check_replacement(struct clock_event_device *curdev,
	struct clock_event_device *newdev);
	extern void tick_install_replacement(struct clock_event_device *dev);
	extern int tick_is_oneshot_available(void);
	extern struct tick_device *tick_get_device(int cpu);

	extern int clockevents_tick_resume(struct clock_event_device *dev);
	/* Check, if the device is functional or a dummy for broadcast */
	static inline int tick_device_is_functional(struct clock_event_device *dev)
	{
	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
	}

	static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
	{
	return dev->state_use_accessors;
	}

	static inline void clockevent_set_state(struct clock_event_device *dev,
	enum clock_event_state state)
	{
	dev->state_use_accessors = state;
	}

	extern void clockevents_shutdown(struct clock_event_device *dev);
	extern void clockevents_exchange_device(struct clock_event_device *old,
	struct clock_event_device *new);
	extern void clockevents_switch_state(struct clock_event_device *dev,
	enum clock_event_state state);
	extern int clockevents_program_event(struct clock_event_device *dev,
	ktime_t expires, bool force);
	extern void clockevents_handle_noop(struct clock_event_device *dev);
	extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);

	/* Broadcasting support */
	# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
	extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
	extern int tick_is_broadcast_device(struct clock_event_device *dev);
	extern void tick_suspend_broadcast(void);
	extern void tick_resume_broadcast(void);
	extern bool tick_resume_check_broadcast(void);
	extern void tick_broadcast_init(void);
	extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
	extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
	extern struct tick_device *tick_get_broadcast_device(void);
	extern struct cpumask *tick_get_broadcast_mask(void);
	extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
	# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
	static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
	static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
	static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
	static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
	static inline void tick_suspend_broadcast(void) { }
	static inline void tick_resume_broadcast(void) { }
	static inline bool tick_resume_check_broadcast(void) { return false; }
	static inline void tick_broadcast_init(void) { }
	static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; }

	/* Set the periodic handler in non broadcast mode */
	static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
	{
	dev->event_handler = tick_handle_periodic;
	}
	# endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */

	#else /* !GENERIC_CLOCKEVENTS: */
	static inline void tick_suspend(void) { }
	static inline void tick_resume(void) { }
	#endif /* !GENERIC_CLOCKEVENTS */

	/* Oneshot related functions */
	#ifdef CONFIG_TICK_ONESHOT
	extern void tick_setup_oneshot(struct clock_event_device *newdev,
	void (handler)(struct clock_event_device ),
	ktime_t nextevt);
	extern int tick_program_event(ktime_t expires, int force);
	extern void tick_oneshot_notify(void);
	extern int tick_switch_to_oneshot(void (handler)(struct clock_event_device ));
	extern void tick_resume_oneshot(void);
	static inline bool tick_oneshot_possible(void) { return true; }
	extern int tick_oneshot_mode_active(void);
	extern void tick_clock_notify(void);
	extern int tick_check_oneshot_change(int allow_nohz);
	extern int tick_init_highres(void);
	#else /* !CONFIG_TICK_ONESHOT: */
	static inline
	void tick_setup_oneshot(struct clock_event_device *newdev,
	void (handler)(struct clock_event_device ),
	ktime_t nextevt) { BUG(); }
	static inline void tick_resume_oneshot(void) { BUG(); }
	static inline int tick_program_event(ktime_t expires, int force) { return 0; }
	static inline void tick_oneshot_notify(void) { }
	static inline bool tick_oneshot_possible(void) { return false; }
	static inline int tick_oneshot_mode_active(void) { return 0; }
	static inline void tick_clock_notify(void) { }
	static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
	#endif /* !CONFIG_TICK_ONESHOT */

	/* Functions related to oneshot broadcasting */
	#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
	extern void tick_broadcast_switch_to_oneshot(void);
	extern int tick_broadcast_oneshot_active(void);
	extern void tick_check_oneshot_broadcast_this_cpu(void);
	bool tick_broadcast_oneshot_available(void);
	extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
	#else /* !(BROADCAST && ONESHOT): */
	static inline void tick_broadcast_switch_to_oneshot(void) { }
	static inline int tick_broadcast_oneshot_active(void) { return 0; }
	static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
	static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
	#endif /* !(BROADCAST && ONESHOT) */

	#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
	extern void tick_offline_cpu(unsigned int cpu);
	extern void tick_broadcast_offline(unsigned int cpu);
	#else
	static inline void tick_offline_cpu(unsigned int cpu) { }
	static inline void tick_broadcast_offline(unsigned int cpu) { }
	#endif

	/* NO_HZ_FULL internal */
	#ifdef CONFIG_NO_HZ_FULL
	extern void tick_nohz_init(void);
	# else
	static inline void tick_nohz_init(void) { }
	#endif

	#ifdef CONFIG_NO_HZ_COMMON
	extern unsigned long tick_nohz_active;
	extern void timers_update_nohz(void);
	extern u64 get_jiffies_update(unsigned long *basej);
	# ifdef CONFIG_SMP
	extern struct static_key_false timers_migration_enabled;
	extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
	struct timer_events *tevt,
	unsigned int cpu);
	extern void timer_lock_remote_bases(unsigned int cpu);
	extern void timer_unlock_remote_bases(unsigned int cpu);
	extern bool timer_base_is_idle(void);
	extern void timer_expire_remote(unsigned int cpu);
	# endif
	#else /* CONFIG_NO_HZ_COMMON */
	static inline void timers_update_nohz(void) { }
	#define tick_nohz_active (0)
	#endif

	DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);

	extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
	u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
	void timer_clear_idle(void);

	#define CLOCK_SET_WALL \
	(BIT(HRTIMER_BASE_REALTIME) \| BIT(HRTIMER_BASE_REALTIME_SOFT) \| \
	BIT(HRTIMER_BASE_TAI) \| BIT(HRTIMER_BASE_TAI_SOFT))

	#define CLOCK_SET_BOOT \
	(BIT(HRTIMER_BASE_BOOTTIME) \| BIT(HRTIMER_BASE_BOOTTIME_SOFT))

	void clock_was_set(unsigned int bases);
	void clock_was_set_delayed(void);

	void hrtimers_resume_local(void);

	/* Since jiffies uses a simple TICK_NSEC multiplier
	* conversion, the .shift value could be zero. However
	* this would make NTP adjustments impossible as they are
	* in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
	* shift both the nominator and denominator the same
	* amount, and give ntp adjustments in units of 1/2^8
	*
	* The value 8 is somewhat carefully chosen, as anything
	* larger can result in overflows. TICK_NSEC grows as HZ
	* shrinks, so values greater than 8 overflow 32bits when
	* HZ=100.
	*/
	#if HZ < 34
	#define JIFFIES_SHIFT 6
	#elif HZ < 67
	#define JIFFIES_SHIFT 7
	#else
	#define JIFFIES_SHIFT 8
	#endif

	extern ssize_t sysfs_get_uname(const char buf, char dst, size_t cnt);