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https://github.com/edk2-porting/linux-next.git
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b996544916
The variable tick_period is initialized to NSEC_PER_TICK / HZ during boot and never updated again. If NSEC_PER_TICK is not an integer multiple of HZ this computation is less accurate than TICK_NSEC which has proper rounding in place. Aside of the inaccuracy there is no reason for having this variable at all. It's just a pointless indirection and all usage sites can just use the TICK_NSEC constant. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201117132006.766643526@linutronix.de
167 lines
6.8 KiB
C
167 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* tick internal variable and functions used by low/high res code
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*/
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#include <linux/hrtimer.h>
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#include <linux/tick.h>
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#include "timekeeping.h"
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#include "tick-sched.h"
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#ifdef CONFIG_GENERIC_CLOCKEVENTS
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# define TICK_DO_TIMER_NONE -1
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# define TICK_DO_TIMER_BOOT -2
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DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
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extern ktime_t tick_next_period;
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extern int tick_do_timer_cpu __read_mostly;
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extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
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extern void tick_handle_periodic(struct clock_event_device *dev);
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extern void tick_check_new_device(struct clock_event_device *dev);
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extern void tick_shutdown(unsigned int cpu);
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extern void tick_suspend(void);
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extern void tick_resume(void);
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extern bool tick_check_replacement(struct clock_event_device *curdev,
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struct clock_event_device *newdev);
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extern void tick_install_replacement(struct clock_event_device *dev);
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extern int tick_is_oneshot_available(void);
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extern struct tick_device *tick_get_device(int cpu);
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extern int clockevents_tick_resume(struct clock_event_device *dev);
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/* Check, if the device is functional or a dummy for broadcast */
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static inline int tick_device_is_functional(struct clock_event_device *dev)
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{
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return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
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}
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static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
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{
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return dev->state_use_accessors;
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}
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static inline void clockevent_set_state(struct clock_event_device *dev,
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enum clock_event_state state)
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{
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dev->state_use_accessors = state;
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}
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extern void clockevents_shutdown(struct clock_event_device *dev);
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extern void clockevents_exchange_device(struct clock_event_device *old,
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struct clock_event_device *new);
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extern void clockevents_switch_state(struct clock_event_device *dev,
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enum clock_event_state state);
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extern int clockevents_program_event(struct clock_event_device *dev,
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ktime_t expires, bool force);
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extern void clockevents_handle_noop(struct clock_event_device *dev);
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extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
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extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
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/* Broadcasting support */
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# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
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extern void tick_install_broadcast_device(struct clock_event_device *dev);
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extern int tick_is_broadcast_device(struct clock_event_device *dev);
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extern void tick_suspend_broadcast(void);
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extern void tick_resume_broadcast(void);
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extern bool tick_resume_check_broadcast(void);
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extern void tick_broadcast_init(void);
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extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
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extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
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extern struct tick_device *tick_get_broadcast_device(void);
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extern struct cpumask *tick_get_broadcast_mask(void);
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# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
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static inline void tick_install_broadcast_device(struct clock_event_device *dev) { }
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static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
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static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
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static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
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static inline void tick_suspend_broadcast(void) { }
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static inline void tick_resume_broadcast(void) { }
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static inline bool tick_resume_check_broadcast(void) { return false; }
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static inline void tick_broadcast_init(void) { }
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static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; }
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/* Set the periodic handler in non broadcast mode */
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static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
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{
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dev->event_handler = tick_handle_periodic;
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}
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# endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */
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#else /* !GENERIC_CLOCKEVENTS: */
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static inline void tick_suspend(void) { }
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static inline void tick_resume(void) { }
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#endif /* !GENERIC_CLOCKEVENTS */
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/* Oneshot related functions */
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#ifdef CONFIG_TICK_ONESHOT
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extern void tick_setup_oneshot(struct clock_event_device *newdev,
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void (*handler)(struct clock_event_device *),
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ktime_t nextevt);
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extern int tick_program_event(ktime_t expires, int force);
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extern void tick_oneshot_notify(void);
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extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
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extern void tick_resume_oneshot(void);
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static inline bool tick_oneshot_possible(void) { return true; }
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extern int tick_oneshot_mode_active(void);
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extern void tick_clock_notify(void);
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extern int tick_check_oneshot_change(int allow_nohz);
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extern int tick_init_highres(void);
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#else /* !CONFIG_TICK_ONESHOT: */
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static inline
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void tick_setup_oneshot(struct clock_event_device *newdev,
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void (*handler)(struct clock_event_device *),
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ktime_t nextevt) { BUG(); }
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static inline void tick_resume_oneshot(void) { BUG(); }
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static inline int tick_program_event(ktime_t expires, int force) { return 0; }
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static inline void tick_oneshot_notify(void) { }
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static inline bool tick_oneshot_possible(void) { return false; }
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static inline int tick_oneshot_mode_active(void) { return 0; }
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static inline void tick_clock_notify(void) { }
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static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
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#endif /* !CONFIG_TICK_ONESHOT */
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/* Functions related to oneshot broadcasting */
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#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
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extern void tick_broadcast_switch_to_oneshot(void);
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extern int tick_broadcast_oneshot_active(void);
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extern void tick_check_oneshot_broadcast_this_cpu(void);
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bool tick_broadcast_oneshot_available(void);
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extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
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#else /* !(BROADCAST && ONESHOT): */
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static inline void tick_broadcast_switch_to_oneshot(void) { }
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static inline int tick_broadcast_oneshot_active(void) { return 0; }
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static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
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static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
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#endif /* !(BROADCAST && ONESHOT) */
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#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
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extern void tick_broadcast_offline(unsigned int cpu);
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#else
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static inline void tick_broadcast_offline(unsigned int cpu) { }
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#endif
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/* NO_HZ_FULL internal */
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#ifdef CONFIG_NO_HZ_FULL
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extern void tick_nohz_init(void);
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# else
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static inline void tick_nohz_init(void) { }
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#endif
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#ifdef CONFIG_NO_HZ_COMMON
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extern unsigned long tick_nohz_active;
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extern void timers_update_nohz(void);
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# ifdef CONFIG_SMP
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extern struct static_key_false timers_migration_enabled;
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# endif
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#else /* CONFIG_NO_HZ_COMMON */
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static inline void timers_update_nohz(void) { }
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#define tick_nohz_active (0)
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#endif
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DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
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extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
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void timer_clear_idle(void);
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