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When the per cpu timer is marked CLOCK_EVT_FEAT_C3STOP, then we only can switch into oneshot mode, when the backup broadcast device supports oneshot mode as well. Otherwise we would try to switch the broadcast device into an unsupported mode unconditionally. This went unnoticed so far as the current available broadcast devices support oneshot mode. Seth unearthed this problem while debugging and working around an hpet related BIOS wreckage. Add the necessary check to tick_is_oneshot_available(). Reported-and-tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1102252231200.2701@localhost6.localdomain6> Cc: stable@kernel.org # .21 ->
138 lines
4.6 KiB
C
138 lines
4.6 KiB
C
/*
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* tick internal variable and functions used by low/high res code
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*/
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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 ktime_t tick_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 clockevents_shutdown(struct clock_event_device *dev);
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/*
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* NO_HZ / high resolution timer shared code
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*/
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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_dev_program_event(struct clock_event_device *dev,
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ktime_t expires, int force);
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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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# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
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extern void tick_broadcast_oneshot_control(unsigned long reason);
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extern void tick_broadcast_switch_to_oneshot(void);
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extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
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extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
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extern int tick_broadcast_oneshot_active(void);
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extern void tick_check_oneshot_broadcast(int cpu);
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bool tick_broadcast_oneshot_available(void);
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# else /* BROADCAST */
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static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
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{
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BUG();
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}
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static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
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static inline void tick_broadcast_switch_to_oneshot(void) { }
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static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
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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(int cpu) { }
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static inline bool tick_broadcast_oneshot_available(void) { return true; }
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# endif /* !BROADCAST */
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#else /* !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)
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{
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BUG();
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}
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static inline void tick_resume_oneshot(void)
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{
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BUG();
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}
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static inline int tick_program_event(ktime_t expires, int force)
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{
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return 0;
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}
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static inline void tick_oneshot_notify(void) { }
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static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
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{
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BUG();
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}
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static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
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static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
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static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
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{
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return 0;
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}
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static inline int tick_broadcast_oneshot_active(void) { return 0; }
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static inline bool tick_broadcast_oneshot_available(void) { return false; }
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#endif /* !TICK_ONESHOT */
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/*
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* Broadcasting support
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*/
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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 int tick_check_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_broadcast_on_off(unsigned long reason, int *oncpu);
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extern void tick_shutdown_broadcast(unsigned int *cpup);
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extern void tick_suspend_broadcast(void);
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extern int tick_resume_broadcast(void);
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extern void
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tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
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#else /* !BROADCAST */
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static inline int tick_check_broadcast_device(struct clock_event_device *dev)
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{
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return 0;
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}
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static inline int tick_is_broadcast_device(struct clock_event_device *dev)
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{
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return 0;
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}
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static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
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int cpu)
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{
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return 0;
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}
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static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
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static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
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static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
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static inline void tick_suspend_broadcast(void) { }
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static inline int tick_resume_broadcast(void) { return 0; }
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/*
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* Set the periodic handler in non broadcast mode
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*/
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static inline void tick_set_periodic_handler(struct clock_event_device *dev,
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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 /* !BROADCAST */
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/*
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* Check, if the device is functional or a dummy for broadcast
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*/
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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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