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_offline_cpu(unsigned int cpu);

            
            extern void tick_shutdown(void);

            
            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_broadcast_offline(unsigned int cpu);

            
            #else

            
            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 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) { }

            
            #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_offline_cpu(unsigned int cpu);
	extern void tick_shutdown(void);
	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_broadcast_offline(unsigned int cpu);
	#else
	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 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) { }
	#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);