Commit dc2c9ad5 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Don't expose srcu_head to register notifiers 



Let the OPP core provide helpers to register notifiers for any device,
instead of exposing srcu_head outside of the core.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Acked-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 3aa26a3b

drivers/base/power/opp/core.c

+50 −16
Original line number Diff line number Diff line
@@ -1860,29 +1860,63 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) 
EXPORT_SYMBOL_GPL(dev_pm_opp_disable);



/**

 * dev_pm_opp_get_notifier() - find notifier_head of the device with opp

 * @dev:	device pointer used to lookup OPP table.

 * dev_pm_opp_register_notifier() - Register OPP notifier for the device

 * @dev:	Device for which notifier needs to be registered

 * @nb:		Notifier block to be registered

 *

 * Return: pointer to  notifier head if found, otherwise -ENODEV or

 * -EINVAL based on type of error casted as pointer. value must be checked

 *  with IS_ERR to determine valid pointer or error result.

 * Return: 0 on success or a negative error value.

 */

int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)

{

	struct opp_table *opp_table;

	int ret;



	rcu_read_lock();



	opp_table = _find_opp_table(dev);

	if (IS_ERR(opp_table)) {

		ret = PTR_ERR(opp_table);

		goto unlock;

	}



	ret = srcu_notifier_chain_register(&opp_table->srcu_head, nb);



unlock:

	rcu_read_unlock();



	return ret;

}

EXPORT_SYMBOL(dev_pm_opp_register_notifier);



/**

 * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device

 * @dev:	Device for which notifier needs to be unregistered

 * @nb:		Notifier block to be unregistered

 *

 * Locking: This function must be called under rcu_read_lock(). opp_table is a

 * RCU protected pointer. The reason for the same is that the opp pointer which

 * is returned will remain valid for use with opp_get_{voltage, freq} only while

 * under the locked area. The pointer returned must be used prior to unlocking

 * with rcu_read_unlock() to maintain the integrity of the pointer.

 * Return: 0 on success or a negative error value.

 */

struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)

int dev_pm_opp_unregister_notifier(struct device *dev,

				   struct notifier_block *nb)

{

	struct opp_table *opp_table = _find_opp_table(dev);

	struct opp_table *opp_table;

	int ret;



	if (IS_ERR(opp_table))

		return ERR_CAST(opp_table); /* matching type */

	rcu_read_lock();



	opp_table = _find_opp_table(dev);

	if (IS_ERR(opp_table)) {

		ret = PTR_ERR(opp_table);

		goto unlock;

	}



	ret = srcu_notifier_chain_unregister(&opp_table->srcu_head, nb);



	return &opp_table->srcu_head;

unlock:

	rcu_read_unlock();



	return ret;

}

EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);

EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);



/*

 * Free OPPs either created using static entries present in DT or even the

drivers/devfreq/devfreq.c

+2 −24
Original line number Diff line number Diff line
@@ -1265,18 +1265,7 @@ EXPORT_SYMBOL(devfreq_recommended_opp); 
 */

int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)

{

	struct srcu_notifier_head *nh;

	int ret = 0;



	rcu_read_lock();

	nh = dev_pm_opp_get_notifier(dev);

	if (IS_ERR(nh))

		ret = PTR_ERR(nh);

	rcu_read_unlock();

	if (!ret)

		ret = srcu_notifier_chain_register(nh, &devfreq->nb);



	return ret;

	return dev_pm_opp_register_notifier(dev, &devfreq->nb);

}

EXPORT_SYMBOL(devfreq_register_opp_notifier);
@@ -1292,18 +1281,7 @@ EXPORT_SYMBOL(devfreq_register_opp_notifier); 
 */

int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)

{

	struct srcu_notifier_head *nh;

	int ret = 0;



	rcu_read_lock();

	nh = dev_pm_opp_get_notifier(dev);

	if (IS_ERR(nh))

		ret = PTR_ERR(nh);

	rcu_read_unlock();

	if (!ret)

		ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);



	return ret;

	return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);

}

EXPORT_SYMBOL(devfreq_unregister_opp_notifier);

include/linux/pm_opp.h

+10 −4
Original line number Diff line number Diff line
@@ -108,7 +108,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq); 


int dev_pm_opp_disable(struct device *dev, unsigned long freq);



struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);

int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb);

int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb);



int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,

				unsigned int count);

void dev_pm_opp_put_supported_hw(struct device *dev);
@@ -202,10 +204,14 @@ static inline int dev_pm_opp_disable(struct device *dev, unsigned long freq) 
	return 0;

}



static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(

							struct device *dev)

static inline int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)

{

	return ERR_PTR(-ENOTSUPP);

	return -ENOTSUPP;

}



static inline int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb)

{

	return -ENOTSUPP;

}



static inline int dev_pm_opp_set_supported_hw(struct device *dev,