Merge "clocksource: add API to force re-selection of the best clocksource" (531c9c5b) · Commits · e / devices / android_kernel_oneplus_sm7250

include/linux/clocksource.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -194,6 +194,7 @@ extern void clocksource_suspend(void);
		extern void clocksource_resume(void);
		extern struct clocksource * __init clocksource_default_clock(void);
		extern void clocksource_mark_unstable(struct clocksource *cs);
		extern void clocksource_select_force(void);

		extern u64
		clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask, u64 *max_cycles);

kernel/time/clocksource.c

+33 −13

Original line number	Diff line number	Diff line
		@@ -109,7 +109,7 @@ static int finished_booting;

		#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
		static void clocksource_watchdog_work(struct work_struct *work);
		static void clocksource_select(void);
		static void clocksource_select(bool force);

		static LIST_HEAD(watchdog_list);
		static struct clocksource *watchdog;
		@@ -560,11 +560,12 @@ static inline void clocksource_update_max_deferment(struct clocksource *cs)

		#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET

		static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur)
		static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur,
		bool force)
		{
		struct clocksource *cs;

		if (!finished_booting \|\| list_empty(&clocksource_list))
		if ((!finished_booting && !force) \|\| list_empty(&clocksource_list))
		return NULL;

		/*
		@@ -582,13 +583,13 @@ static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur)
		return NULL;
		}

		static void __clocksource_select(bool skipcur)
		static void __clocksource_select(bool skipcur, bool force)
		{
		bool oneshot = tick_oneshot_mode_active();
		struct clocksource best, cs;

		/* Find the best suitable clocksource */
		best = clocksource_find_best(oneshot, skipcur);
		best = clocksource_find_best(oneshot, skipcur, force);
		if (!best)
		return;

		@@ -641,22 +642,40 @@ static void __clocksource_select(bool skipcur)
		* Select the clocksource with the best rating, or the clocksource,
		* which is selected by userspace override.
		*/
		static void clocksource_select(void)
		static void clocksource_select(bool force)
		{
		__clocksource_select(false);
		return __clocksource_select(false, force);
		}

		static void clocksource_select_fallback(void)
		{
		__clocksource_select(true);
		__clocksource_select(true, false);
		}

		#else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */
		static inline void clocksource_select(void) { }

		static inline void clocksource_select(bool force) { }
		static inline void clocksource_select_fallback(void) { }

		#endif

		/**
		* clocksource_select_force - Force re-selection of the best clocksource
		* among registered clocksources
		*
		* clocksource_select() can't select the best clocksource before
		* calling clocksource_done_booting() and since clocksource_select()
		* should be called with clocksource_mutex held, provide a new API
		* can be called from other files to select best clockrouce irrespective
		* of finished_booting flag.
		*/
		void clocksource_select_force(void)
		{
		mutex_lock(&clocksource_mutex);
		clocksource_select(true);
		mutex_unlock(&clocksource_mutex);
		}

		/*
		* clocksource_done_booting - Called near the end of core bootup
		*
		@@ -673,7 +692,7 @@ static int __init clocksource_done_booting(void)
		* Run the watchdog first to eliminate unstable clock sources
		*/
		__clocksource_watchdog_work();
		clocksource_select();
		clocksource_select(false);
		mutex_unlock(&clocksource_mutex);
		return 0;
		}
		@@ -764,6 +783,7 @@ void __clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq
		}
		EXPORT_SYMBOL_GPL(__clocksource_update_freq_scale);


		/**
		* __clocksource_register_scale - Used to install new clocksources
		* @cs: clocksource to be registered
		@@ -790,7 +810,7 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
		clocksource_enqueue_watchdog(cs);
		clocksource_watchdog_unlock(&flags);

		clocksource_select();
		clocksource_select(false);
		clocksource_select_watchdog(false);
		mutex_unlock(&clocksource_mutex);
		return 0;
		@@ -818,7 +838,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
		__clocksource_change_rating(cs, rating);
		clocksource_watchdog_unlock(&flags);

		clocksource_select();
		clocksource_select(false);
		clocksource_select_watchdog(false);
		mutex_unlock(&clocksource_mutex);
		}
		@@ -928,7 +948,7 @@ static ssize_t current_clocksource_store(struct device *dev,

		ret = sysfs_get_uname(buf, override_name, count);
		if (ret >= 0)
		clocksource_select();
		clocksource_select(false);

		mutex_unlock(&clocksource_mutex);