Commit 23dacf6d authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Break _opp_add_dynamic() into smaller functions 



Later commits would add support for new OPP bindings and this would be
required then. So, lets do it in a separate patch to make it easily
reviewable.

Another change worth noticing is INIT_LIST_HEAD(&opp->node). We weren't
doing it earlier as we never tried to delete a list node before it is
added to list. But this wouldn't be the case anymore. We might try to
delete a node (just to reuse the same code paths), without it being
getting added to the list.

Reviewed-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent aa5f2f85

drivers/base/power/opp.c

+76 −49
Original line number Diff line number Diff line
@@ -484,6 +484,7 @@ static void _kfree_opp_rcu(struct rcu_head *head) 
 * _opp_remove()  - Remove an OPP from a table definition

 * @dev_opp:	points back to the device_opp struct this opp belongs to

 * @opp:	pointer to the OPP to remove

 * @notify:	OPP_EVENT_REMOVE notification should be sent or not

 *

 * This function removes an opp definition from the opp list.

 *
@@ -492,12 +493,13 @@ static void _kfree_opp_rcu(struct rcu_head *head) 
 * strategy.

 */

static void _opp_remove(struct device_opp *dev_opp,

			struct dev_pm_opp *opp)

			struct dev_pm_opp *opp, bool notify)

{

	/*

	 * Notify the changes in the availability of the operable

	 * frequency/voltage list.

	 */

	if (notify)

		srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);

	list_del_rcu(&opp->node);

	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
@@ -544,12 +546,70 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) 
		goto unlock;

	}



	_opp_remove(dev_opp, opp);

	_opp_remove(dev_opp, opp, true);

unlock:

	mutex_unlock(&dev_opp_list_lock);

}

EXPORT_SYMBOL_GPL(dev_pm_opp_remove);



static struct dev_pm_opp *_allocate_opp(struct device *dev,

					struct device_opp **dev_opp)

{

	struct dev_pm_opp *opp;



	/* allocate new OPP node */

	opp = kzalloc(sizeof(*opp), GFP_KERNEL);

	if (!opp)

		return NULL;



	INIT_LIST_HEAD(&opp->node);



	*dev_opp = _add_device_opp(dev);

	if (!*dev_opp) {

		kfree(opp);

		return NULL;

	}



	return opp;

}



static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)

{

	struct dev_pm_opp *opp;

	struct list_head *head = &dev_opp->opp_list;



	/*

	 * Insert new OPP in order of increasing frequency and discard if

	 * already present.

	 *

	 * Need to use &dev_opp->opp_list in the condition part of the 'for'

	 * loop, don't replace it with head otherwise it will become an infinite

	 * loop.

	 */

	list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {

		if (new_opp->rate > opp->rate) {

			head = &opp->node;

			continue;

		}



		if (new_opp->rate < opp->rate)

			break;



		/* Duplicate OPPs */

		dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",

			 __func__, opp->rate, opp->u_volt, opp->available,

			 new_opp->rate, new_opp->u_volt, new_opp->available);



		return opp->available && new_opp->u_volt == opp->u_volt ?

			0 : -EEXIST;

	}



	new_opp->dev_opp = dev_opp;

	list_add_rcu(&new_opp->node, head);



	return 0;

}



/**

 * _opp_add_dynamic() - Allocate a dynamic OPP.

 * @dev:	device for which we do this operation
@@ -581,62 +641,28 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, 
			    long u_volt, bool dynamic)

{

	struct device_opp *dev_opp;

	struct dev_pm_opp *opp, *new_opp;

	struct list_head *head;

	struct dev_pm_opp *new_opp;

	int ret;



	/* allocate new OPP node */

	new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL);

	if (!new_opp)

		return -ENOMEM;



	/* Hold our list modification lock here */

	mutex_lock(&dev_opp_list_lock);



	new_opp = _allocate_opp(dev, &dev_opp);

	if (!new_opp) {

		ret = -ENOMEM;

		goto unlock;

	}



	/* populate the opp table */

	new_opp->rate = freq;

	new_opp->u_volt = u_volt;

	new_opp->available = true;

	new_opp->dynamic = dynamic;



	dev_opp = _add_device_opp(dev);

	if (!dev_opp) {

		ret = -ENOMEM;

		goto free_opp;

	}



	/*

	 * Insert new OPP in order of increasing frequency

	 * and discard if already present

	 */

	head = &dev_opp->opp_list;



	/*

	 * Need to use &dev_opp->opp_list in the condition part of the 'for'

	 * loop, don't replace it with head otherwise it will become an infinite

	 * loop.

	 */

	list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {

		if (new_opp->rate > opp->rate) {

			head = &opp->node;

			continue;

		}



		if (new_opp->rate < opp->rate)

			break;



		/* Duplicate OPPs */

		ret = opp->available && new_opp->u_volt == opp->u_volt ?

			0 : -EEXIST;



		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",

			 __func__, opp->rate, opp->u_volt, opp->available,

			 new_opp->rate, new_opp->u_volt, new_opp->available);

	ret = _opp_add(new_opp, dev_opp);

	if (ret)

		goto free_opp;

	}



	new_opp->dynamic = dynamic;

	new_opp->dev_opp = dev_opp;

	list_add_rcu(&new_opp->node, head);

	mutex_unlock(&dev_opp_list_lock);



	/*
@@ -647,8 +673,9 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, 
	return 0;



free_opp:

	_opp_remove(dev_opp, new_opp, false);

unlock:

	mutex_unlock(&dev_opp_list_lock);

	kfree(new_opp);

	return ret;

}
@@ -876,7 +903,7 @@ void of_free_opp_table(struct device *dev) 
	/* Free static OPPs */

	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {

		if (!opp->dynamic)

			_opp_remove(dev_opp, opp);

			_opp_remove(dev_opp, opp, true);

	}



	mutex_unlock(&dev_opp_list_lock);

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