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![Peter Zijlstra](/assets/img/avatar_default.png)
The whole disable-RCU, enable-IRQS dance is very intricate since changing IRQ state is traced, which depends on RCU. Add two helpers for the cpuidle case that mirror the entry code: ct_cpuidle_enter() ct_cpuidle_exit() And fix all the cases where the enter/exit dance was buggy. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org
227 lines
7.3 KiB
C
227 lines
7.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* linux/include/linux/clockchips.h
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*
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* This file contains the structure definitions for clockchips.
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*
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* If you are not a clockchip, or the time of day code, you should
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* not be including this file!
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*/
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#ifndef _LINUX_CLOCKCHIPS_H
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#define _LINUX_CLOCKCHIPS_H
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#ifdef CONFIG_GENERIC_CLOCKEVENTS
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# include <linux/clocksource.h>
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# include <linux/cpumask.h>
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# include <linux/ktime.h>
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# include <linux/notifier.h>
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struct clock_event_device;
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struct module;
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/*
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* Possible states of a clock event device.
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*
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* DETACHED: Device is not used by clockevents core. Initial state or can be
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* reached from SHUTDOWN.
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* SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.
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* PERIODIC: Device is programmed to generate events periodically. Can be
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* reached from DETACHED or SHUTDOWN.
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* ONESHOT: Device is programmed to generate event only once. Can be reached
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* from DETACHED or SHUTDOWN.
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* ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily
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* stopped.
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*/
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enum clock_event_state {
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CLOCK_EVT_STATE_DETACHED,
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CLOCK_EVT_STATE_SHUTDOWN,
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CLOCK_EVT_STATE_PERIODIC,
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CLOCK_EVT_STATE_ONESHOT,
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CLOCK_EVT_STATE_ONESHOT_STOPPED,
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};
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/*
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* Clock event features
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*/
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# define CLOCK_EVT_FEAT_PERIODIC 0x000001
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# define CLOCK_EVT_FEAT_ONESHOT 0x000002
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# define CLOCK_EVT_FEAT_KTIME 0x000004
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/*
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* x86(64) specific (mis)features:
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*
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* - Clockevent source stops in C3 State and needs broadcast support.
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* - Local APIC timer is used as a dummy device.
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*/
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# define CLOCK_EVT_FEAT_C3STOP 0x000008
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# define CLOCK_EVT_FEAT_DUMMY 0x000010
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/*
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* Core shall set the interrupt affinity dynamically in broadcast mode
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*/
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# define CLOCK_EVT_FEAT_DYNIRQ 0x000020
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# define CLOCK_EVT_FEAT_PERCPU 0x000040
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/*
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* Clockevent device is based on a hrtimer for broadcast
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*/
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# define CLOCK_EVT_FEAT_HRTIMER 0x000080
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/**
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* struct clock_event_device - clock event device descriptor
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* @event_handler: Assigned by the framework to be called by the low
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* level handler of the event source
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* @set_next_event: set next event function using a clocksource delta
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* @set_next_ktime: set next event function using a direct ktime value
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* @next_event: local storage for the next event in oneshot mode
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* @max_delta_ns: maximum delta value in ns
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* @min_delta_ns: minimum delta value in ns
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* @mult: nanosecond to cycles multiplier
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* @shift: nanoseconds to cycles divisor (power of two)
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* @state_use_accessors:current state of the device, assigned by the core code
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* @features: features
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* @retries: number of forced programming retries
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* @set_state_periodic: switch state to periodic
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* @set_state_oneshot: switch state to oneshot
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* @set_state_oneshot_stopped: switch state to oneshot_stopped
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* @set_state_shutdown: switch state to shutdown
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* @tick_resume: resume clkevt device
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* @broadcast: function to broadcast events
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* @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
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* @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
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* @name: ptr to clock event name
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* @rating: variable to rate clock event devices
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* @irq: IRQ number (only for non CPU local devices)
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* @bound_on: Bound on CPU
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* @cpumask: cpumask to indicate for which CPUs this device works
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* @list: list head for the management code
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* @owner: module reference
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*/
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struct clock_event_device {
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void (*event_handler)(struct clock_event_device *);
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int (*set_next_event)(unsigned long evt, struct clock_event_device *);
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int (*set_next_ktime)(ktime_t expires, struct clock_event_device *);
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ktime_t next_event;
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u64 max_delta_ns;
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u64 min_delta_ns;
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u32 mult;
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u32 shift;
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enum clock_event_state state_use_accessors;
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unsigned int features;
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unsigned long retries;
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int (*set_state_periodic)(struct clock_event_device *);
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int (*set_state_oneshot)(struct clock_event_device *);
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int (*set_state_oneshot_stopped)(struct clock_event_device *);
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int (*set_state_shutdown)(struct clock_event_device *);
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int (*tick_resume)(struct clock_event_device *);
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void (*broadcast)(const struct cpumask *mask);
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void (*suspend)(struct clock_event_device *);
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void (*resume)(struct clock_event_device *);
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unsigned long min_delta_ticks;
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unsigned long max_delta_ticks;
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const char *name;
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int rating;
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int irq;
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int bound_on;
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const struct cpumask *cpumask;
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struct list_head list;
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struct module *owner;
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} ____cacheline_aligned;
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/* Helpers to verify state of a clockevent device */
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static inline bool clockevent_state_detached(struct clock_event_device *dev)
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{
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return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED;
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}
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static inline bool clockevent_state_shutdown(struct clock_event_device *dev)
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{
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return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN;
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}
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static inline bool clockevent_state_periodic(struct clock_event_device *dev)
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{
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return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC;
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}
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static inline bool clockevent_state_oneshot(struct clock_event_device *dev)
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{
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return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT;
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}
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static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev)
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{
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return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED;
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}
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/*
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* Calculate a multiplication factor for scaled math, which is used to convert
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* nanoseconds based values to clock ticks:
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*
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* clock_ticks = (nanoseconds * factor) >> shift.
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*
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* div_sc is the rearranged equation to calculate a factor from a given clock
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* ticks / nanoseconds ratio:
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*
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* factor = (clock_ticks << shift) / nanoseconds
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*/
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static inline unsigned long
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div_sc(unsigned long ticks, unsigned long nsec, int shift)
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{
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u64 tmp = ((u64)ticks) << shift;
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do_div(tmp, nsec);
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return (unsigned long) tmp;
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}
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/* Clock event layer functions */
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extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt);
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extern void clockevents_register_device(struct clock_event_device *dev);
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extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
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extern void clockevents_config_and_register(struct clock_event_device *dev,
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u32 freq, unsigned long min_delta,
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unsigned long max_delta);
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extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
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static inline void
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clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec)
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{
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return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, maxsec);
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}
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extern void clockevents_suspend(void);
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extern void clockevents_resume(void);
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# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
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extern void tick_broadcast(const struct cpumask *mask);
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# else
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# define tick_broadcast NULL
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# endif
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extern int tick_receive_broadcast(void);
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# endif
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# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
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extern void tick_setup_hrtimer_broadcast(void);
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extern int tick_check_broadcast_expired(void);
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# else
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static __always_inline int tick_check_broadcast_expired(void) { return 0; }
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static inline void tick_setup_hrtimer_broadcast(void) { }
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# endif
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#else /* !CONFIG_GENERIC_CLOCKEVENTS: */
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static inline void clockevents_suspend(void) { }
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static inline void clockevents_resume(void) { }
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static __always_inline int tick_check_broadcast_expired(void) { return 0; }
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static inline void tick_setup_hrtimer_broadcast(void) { }
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#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
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#endif /* _LINUX_CLOCKCHIPS_H */
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