Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b83c1899 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Use dev_pm_opp_get_opp_table() instead of _add_opp_table() 



Migrate all users of _add_opp_table() to use dev_pm_opp_get_opp_table()
to guarantee that the OPP table doesn't get freed while being used.

Also update _managed_opp() to get the reference to the OPP table.

Now that the OPP table wouldn't get freed while these routines are
executing after dev_pm_opp_get_opp_table() is called, there is no need
to take opp_table_lock. Drop them as well.

Now that _add_opp_table(), _remove_opp_table() and the unlocked release
routines aren't used anymore, remove them.

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 31641cda

drivers/base/power/opp/core.c

+5 −58
Original line number Diff line number Diff line
@@ -862,27 +862,6 @@ static struct opp_table *_allocate_opp_table(struct device *dev) 
	return opp_table;

}



/**

 * _add_opp_table() - Find OPP table or allocate a new one

 * @dev:	device for which we do this operation

 *

 * It tries to find an existing table first, if it couldn't find one, it

 * allocates a new OPP table and returns that.

 *

 * Return: valid opp_table pointer if success, else NULL.

 */

struct opp_table *_add_opp_table(struct device *dev)

{

	struct opp_table *opp_table;



	/* Check for existing table for 'dev' first */

	opp_table = _find_opp_table(dev);

	if (!IS_ERR(opp_table))

		return opp_table;



	return _allocate_opp_table(dev);

}



/**

 * _kfree_device_rcu() - Free opp_table RCU handler

 * @head:	RCU head
@@ -922,7 +901,7 @@ struct opp_table *dev_pm_opp_get_opp_table(struct device *dev) 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);



static void _opp_table_kref_release_unlocked(struct kref *kref)

static void _opp_table_kref_release(struct kref *kref)

{

	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);

	struct opp_device *opp_dev;
@@ -943,16 +922,7 @@ static void _opp_table_kref_release_unlocked(struct kref *kref) 
	list_del_rcu(&opp_table->node);

	call_srcu(&opp_table->srcu_head.srcu, &opp_table->rcu_head,

		  _kfree_device_rcu);

}



static void dev_pm_opp_put_opp_table_unlocked(struct opp_table *opp_table)

{

	kref_put(&opp_table->kref, _opp_table_kref_release_unlocked);

}



static void _opp_table_kref_release(struct kref *kref)

{

	_opp_table_kref_release_unlocked(kref);

	mutex_unlock(&opp_table_lock);

}
@@ -963,17 +933,6 @@ void dev_pm_opp_put_opp_table(struct opp_table *opp_table) 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table);



/**

 * _remove_opp_table() - Removes a OPP table

 * @opp_table: OPP table to be removed.

 *

 * Removes/frees OPP table if it doesn't contain any OPPs.

 */

static void _remove_opp_table(struct opp_table *opp_table)

{

	dev_pm_opp_put_opp_table_unlocked(opp_table);

}



void _opp_free(struct dev_pm_opp *opp)

{

	kfree(opp);
@@ -1218,8 +1177,6 @@ int _opp_add_v1(struct opp_table *opp_table, struct device *dev, 
	unsigned long tol;

	int ret;



	opp_rcu_lockdep_assert();



	new_opp = _opp_allocate(opp_table);

	if (!new_opp)

		return -ENOMEM;
@@ -1640,21 +1597,13 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) 
	struct opp_table *opp_table;

	int ret;



	/* Hold our table modification lock here */

	mutex_lock(&opp_table_lock);



	opp_table = _add_opp_table(dev);

	if (!opp_table) {

		ret = -ENOMEM;

		goto unlock;

	}

	opp_table = dev_pm_opp_get_opp_table(dev);

	if (!opp_table)

		return -ENOMEM;



	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);

	if (ret)

		_remove_opp_table(opp_table);



unlock:

	mutex_unlock(&opp_table_lock);

	dev_pm_opp_put_opp_table(opp_table);

	return ret;

}

EXPORT_SYMBOL_GPL(dev_pm_opp_add);
@@ -1865,8 +1814,6 @@ void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, 
{

	struct dev_pm_opp *opp, *tmp;



	opp_rcu_lockdep_assert();



	/* Find if opp_table manages a single device */

	if (list_is_singular(&opp_table->dev_list)) {

		/* Free static OPPs */

drivers/base/power/opp/of.c

+24 −30
Original line number Diff line number Diff line
@@ -24,7 +24,9 @@ 


static struct opp_table *_managed_opp(const struct device_node *np)

{

	struct opp_table *opp_table;

	struct opp_table *opp_table, *managed_table = NULL;



	mutex_lock(&opp_table_lock);



	list_for_each_entry_rcu(opp_table, &opp_tables, node) {

		if (opp_table->np == np) {
@@ -35,14 +37,18 @@ static struct opp_table *_managed_opp(const struct device_node *np) 
			 * But the OPPs will be considered as shared only if the

			 * OPP table contains a "opp-shared" property.

			 */

			if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED)

				return opp_table;

			if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {

				_get_opp_table_kref(opp_table);

				managed_table = opp_table;

			}



			return NULL;

			break;

		}

	}



	return NULL;

	mutex_unlock(&opp_table_lock);



	return managed_table;

}



void _of_init_opp_table(struct opp_table *opp_table, struct device *dev)
@@ -368,21 +374,17 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) 
	struct opp_table *opp_table;

	int ret = 0, count = 0;



	mutex_lock(&opp_table_lock);



	opp_table = _managed_opp(opp_np);

	if (opp_table) {

		/* OPPs are already managed */

		if (!_add_opp_dev(dev, opp_table))

			ret = -ENOMEM;

		goto unlock;

		goto put_opp_table;

	}



	opp_table = _add_opp_table(dev);

	if (!opp_table) {

		ret = -ENOMEM;

		goto unlock;

	}

	opp_table = dev_pm_opp_get_opp_table(dev);

	if (!opp_table)

		return -ENOMEM;



	/* We have opp-table node now, iterate over it and add OPPs */

	for_each_available_child_of_node(opp_np, np) {
@@ -392,14 +394,15 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) 
		if (ret) {

			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,

				ret);

			goto free_table;

			_dev_pm_opp_remove_table(opp_table, dev, false);

			goto put_opp_table;

		}

	}



	/* There should be one of more OPP defined */

	if (WARN_ON(!count)) {

		ret = -ENOENT;

		goto free_table;

		goto put_opp_table;

	}



	opp_table->np = opp_np;
@@ -408,12 +411,8 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) 
	else

		opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;



	goto unlock;



free_table:

	_dev_pm_opp_remove_table(opp_table, dev, false);

unlock:

	mutex_unlock(&opp_table_lock);

put_opp_table:

	dev_pm_opp_put_opp_table(opp_table);



	return ret;

}
@@ -442,13 +441,9 @@ static int _of_add_opp_table_v1(struct device *dev) 
		return -EINVAL;

	}



	mutex_lock(&opp_table_lock);



	opp_table = _add_opp_table(dev);

	if (!opp_table) {

		ret = -ENOMEM;

		goto unlock;

	}

	opp_table = dev_pm_opp_get_opp_table(dev);

	if (!opp_table)

		return -ENOMEM;



	val = prop->value;

	while (nr) {
@@ -465,8 +460,7 @@ static int _of_add_opp_table_v1(struct device *dev) 
		nr -= 2;

	}



unlock:

	mutex_unlock(&opp_table_lock);

	dev_pm_opp_put_opp_table(opp_table);

	return ret;

}

drivers/base/power/opp/opp.h

+0 −1
Original line number Diff line number Diff line
@@ -196,7 +196,6 @@ struct opp_table { 
/* Routines internal to opp core */

void _get_opp_table_kref(struct opp_table *opp_table);

struct opp_table *_find_opp_table(struct device *dev);

struct opp_table *_add_opp_table(struct device *dev);

struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);

void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev, bool remove_all);

void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all);