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

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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: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2017-01-23 10:11:45 +05:30 committed by Rafael J. Wysocki
parent 31641cda53
commit b83c1899a0
3 changed files with 29 additions and 89 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
drivers/base/power/opp/core.c
View File

@ -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 @@ unlock:
}
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 */

54
drivers/base/power/opp/of.c
View File

@ -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;
}

1
drivers/base/power/opp/opp.h
View File

@ -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);