cpuidle: Comment the driver's framework code (6d19cb93) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/cpuidle/driver.c

+126 −6

Original line number	Original line	Diff line number	Diff line
	@@ -22,11 +22,26 @@ DEFINE_SPINLOCK(cpuidle_driver_lock);

	static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);		static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);

			/**
			* __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU.
			* @cpu: the CPU handled by the driver
			*
			* Returns a pointer to struct cpuidle_driver or NULL if no driver has been
			* registered for @cpu.
			*/
	static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)		static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
	{		{
	return per_cpu(cpuidle_drivers, cpu);		return per_cpu(cpuidle_drivers, cpu);
	}		}

			/**
			* __cpuidle_unset_driver - unset per CPU driver variables.
			* @drv: a valid pointer to a struct cpuidle_driver
			*
			* For each CPU in the driver's CPU mask, unset the registered driver per CPU
			* variable. If @drv is different from the registered driver, the corresponding
			* variable is not cleared.
			*/
	static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)		static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
	{		{
	int cpu;		int cpu;
	@@ -40,6 +55,15 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
	}		}
	}		}

			/**
			* __cpuidle_set_driver - set per CPU driver variables the the given driver.
			* @drv: a valid pointer to a struct cpuidle_driver
			*
			* For each CPU in the driver's cpumask, unset the registered driver per CPU
			* to @drv.
			*
			* Returns 0 on success, -EBUSY if the CPUs have driver(s) already.
			*/
	static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)		static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
	{		{
	int cpu;		int cpu;
	@@ -61,11 +85,24 @@ static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)

	static struct cpuidle_driver *cpuidle_curr_driver;		static struct cpuidle_driver *cpuidle_curr_driver;

			/**
			* __cpuidle_get_cpu_driver - return the global cpuidle driver pointer.
			* @cpu: ignored without the multiple driver support
			*
			* Return a pointer to a struct cpuidle_driver object or NULL if no driver was
			* previously registered.
			*/
	static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)		static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
	{		{
	return cpuidle_curr_driver;		return cpuidle_curr_driver;
	}		}

			/**
			* __cpuidle_set_driver - assign the global cpuidle driver variable.
			* @drv: pointer to a struct cpuidle_driver object
			*
			* Returns 0 on success, -EBUSY if the driver is already registered.
			*/
	static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)		static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
	{		{
	if (cpuidle_curr_driver)		if (cpuidle_curr_driver)
	@@ -76,6 +113,13 @@ static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
	return 0;		return 0;
	}		}

			/**
			* __cpuidle_unset_driver - unset the global cpuidle driver variable.
			* @drv: a pointer to a struct cpuidle_driver
			*
			* Reset the global cpuidle variable to NULL. If @drv does not match the
			* registered driver, do nothing.
			*/
	static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)		static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
	{		{
	if (drv == cpuidle_curr_driver)		if (drv == cpuidle_curr_driver)
	@@ -84,21 +128,49 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)

	#endif		#endif

			/**
			* cpuidle_setup_broadcast_timer - enable/disable the broadcast timer
			* @arg: a void pointer used to match the SMP cross call API
			*
			* @arg is used as a value of type 'long' with on of the two values:
			* - CLOCK_EVT_NOTIFY_BROADCAST_ON
			* - CLOCK_EVT_NOTIFY_BROADCAST_OFF
			*
			* Set the broadcast timer notification for the current CPU. This function
			* is executed per CPU by an SMP cross call. It not supposed to be called
			* directly.
			*/
	static void cpuidle_setup_broadcast_timer(void *arg)		static void cpuidle_setup_broadcast_timer(void *arg)
	{		{
	int cpu = smp_processor_id();		int cpu = smp_processor_id();
	clockevents_notify((long)(arg), &cpu);		clockevents_notify((long)(arg), &cpu);
	}		}

			/**
			* __cpuidle_driver_init - initialize the driver's internal data
			* @drv: a valid pointer to a struct cpuidle_driver
			*
			* Returns 0 on success, a negative error code otherwise.
			*/
	static int __cpuidle_driver_init(struct cpuidle_driver *drv)		static int __cpuidle_driver_init(struct cpuidle_driver *drv)
	{		{
	int i;		int i;

	drv->refcnt = 0;		drv->refcnt = 0;

			/*
			* Use all possible CPUs as the default, because if the kernel boots
			* with some CPUs offline and then we online one of them, the CPU
			* notifier has to know which driver to assign.
			*/
	if (!drv->cpumask)		if (!drv->cpumask)
	drv->cpumask = (struct cpumask *)cpu_possible_mask;		drv->cpumask = (struct cpumask *)cpu_possible_mask;

			/*
			* Look for the timer stop flag in the different states, so that we know
			* if the broadcast timer has to be set up. The loop is in the reverse
			* order, because usually on of the the deeper states has this flag set.
			*/
	for (i = drv->state_count - 1; i >= 0 ; i--) {		for (i = drv->state_count - 1; i >= 0 ; i--) {

	if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))		if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
	@@ -111,6 +183,19 @@ static int __cpuidle_driver_init(struct cpuidle_driver *drv)
	return 0;		return 0;
	}		}

			/**
			* __cpuidle_register_driver: register the driver
			* @drv: a valid pointer to a struct cpuidle_driver
			*
			* Do some sanity checks, initialize the driver, assign the driver to the
			* global cpuidle driver variable(s) and set up the broadcast timer if the
			* cpuidle driver has some states that shut down the local timer.
			*
			* Returns 0 on success, a negative error code otherwise:
			* * -EINVAL if the driver pointer is NULL or no idle states are available
			* * -ENODEV if the cpuidle framework is disabled
			* * -EBUSY if the driver is already assigned to the global variable(s)
			*/
	static int __cpuidle_register_driver(struct cpuidle_driver *drv)		static int __cpuidle_register_driver(struct cpuidle_driver *drv)
	{		{
	int ret;		int ret;
	@@ -137,8 +222,13 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
	}		}

	/**		/**
	* cpuidle_unregister_driver - unregisters a driver		* __cpuidle_unregister_driver - unregister the driver
	* @drv: the driver		* @drv: a valid pointer to a struct cpuidle_driver
			*
			* Check if the driver is no longer in use, reset the global cpuidle driver
			* variable(s) and disable the timer broadcast notification mechanism if it was
			* in use.
			*
	*/		*/
	static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)		static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)
	{		{
	@@ -156,7 +246,13 @@ static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)

	/**		/**
	* cpuidle_register_driver - registers a driver		* cpuidle_register_driver - registers a driver
	* @drv: the driver		* @drv: a pointer to a valid struct cpuidle_driver
			*
			* Register the driver under a lock to prevent concurrent attempts to
			* [un]register the driver from occuring at the same time.
			*
			* Returns 0 on success, a negative error code (returned by
			* __cpuidle_register_driver()) otherwise.
	*/		*/
	int cpuidle_register_driver(struct cpuidle_driver *drv)		int cpuidle_register_driver(struct cpuidle_driver *drv)
	{		{
	@@ -172,7 +268,11 @@ EXPORT_SYMBOL_GPL(cpuidle_register_driver);

	/**		/**
	* cpuidle_unregister_driver - unregisters a driver		* cpuidle_unregister_driver - unregisters a driver
	* @drv: the driver		* @drv: a pointer to a valid struct cpuidle_driver
			*
			* Unregisters the cpuidle driver under a lock to prevent concurrent attempts
			* to [un]register the driver from occuring at the same time. @drv has to
			* match the currently registered driver.
	*/		*/
	void cpuidle_unregister_driver(struct cpuidle_driver *drv)		void cpuidle_unregister_driver(struct cpuidle_driver *drv)
	{		{
	@@ -183,7 +283,9 @@ void cpuidle_unregister_driver(struct cpuidle_driver *drv)
	EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);		EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);

	/**		/**
	* cpuidle_get_driver - return the current driver		* cpuidle_get_driver - return the driver tied to the current CPU.
			*
			* Returns a struct cpuidle_driver pointer, or NULL if no driver is registered.
	*/		*/
	struct cpuidle_driver *cpuidle_get_driver(void)		struct cpuidle_driver *cpuidle_get_driver(void)
	{		{
	@@ -199,7 +301,11 @@ struct cpuidle_driver *cpuidle_get_driver(void)
	EXPORT_SYMBOL_GPL(cpuidle_get_driver);		EXPORT_SYMBOL_GPL(cpuidle_get_driver);

	/**		/**
	* cpuidle_get_cpu_driver - return the driver tied with a cpu		* cpuidle_get_cpu_driver - return the driver registered for a CPU.
			* @dev: a valid pointer to a struct cpuidle_device
			*
			* Returns a struct cpuidle_driver pointer, or NULL if no driver is registered
			* for the CPU associated with @dev.
	*/		*/
	struct cpuidle_driver cpuidle_get_cpu_driver(struct cpuidle_device dev)		struct cpuidle_driver cpuidle_get_cpu_driver(struct cpuidle_device dev)
	{		{
	@@ -210,6 +316,14 @@ struct cpuidle_driver cpuidle_get_cpu_driver(struct cpuidle_device dev)
	}		}
	EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);		EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);

			/**
			* cpuidle_driver_ref - get a reference to the driver.
			*
			* Increment the reference counter of the cpuidle driver associated with
			* the current CPU.
			*
			* Returns a pointer to the driver, or NULL if the current CPU has no driver.
			*/
	struct cpuidle_driver *cpuidle_driver_ref(void)		struct cpuidle_driver *cpuidle_driver_ref(void)
	{		{
	struct cpuidle_driver *drv;		struct cpuidle_driver *drv;
	@@ -223,6 +337,12 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
	return drv;		return drv;
	}		}

			/**
			* cpuidle_driver_unref - puts down the refcount for the driver
			*
			* Decrement the reference counter of the cpuidle driver associated with
			* the current CPU.
			*/
	void cpuidle_driver_unref(void)		void cpuidle_driver_unref(void)
	{		{
	struct cpuidle_driver *drv = cpuidle_get_driver();		struct cpuidle_driver *drv = cpuidle_get_driver();