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opp: Reduce the size of critical section in _opp_kref_release()

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There is a lot of stuff here which can be done outside of the
opp_table->lock, do that. This helps avoiding a circular dependency
lockdeps around debugfs.

Reported-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Viresh Kumar 2020-11-19 11:24:32 +05:30
parent 9e62edac51
commit cf1fac943c
1 changed files with 47 additions and 47 deletions
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94
drivers/opp/core.c
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@ -1252,9 +1252,14 @@ void _opp_free(struct dev_pm_opp *opp)
kfree(opp);
}
static void _opp_kref_release(struct dev_pm_opp *opp,
struct opp_table *opp_table)
static void _opp_kref_release(struct kref *kref)
{
struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
struct opp_table *opp_table = opp->opp_table;
list_del(&opp->node);
mutex_unlock(&opp_table->lock);
/*
* Notify the changes in the availability of the operable
* frequency/voltage list.
@ -1262,27 +1267,9 @@ static void _opp_kref_release(struct dev_pm_opp *opp,
blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
_of_opp_free_required_opps(opp_table, opp);
opp_debug_remove_one(opp);
list_del(&opp->node);
kfree(opp);
}
static void _opp_kref_release_unlocked(struct kref *kref)
{
struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
struct opp_table *opp_table = opp->opp_table;
_opp_kref_release(opp, opp_table);
}
static void _opp_kref_release_locked(struct kref *kref)
{
struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
struct opp_table *opp_table = opp->opp_table;
_opp_kref_release(opp, opp_table);
mutex_unlock(&opp_table->lock);
}
void dev_pm_opp_get(struct dev_pm_opp *opp)
{
kref_get(&opp->kref);
@ -1290,16 +1277,10 @@ void dev_pm_opp_get(struct dev_pm_opp *opp)
void dev_pm_opp_put(struct dev_pm_opp *opp)
{
kref_put_mutex(&opp->kref, _opp_kref_release_locked,
&opp->opp_table->lock);
kref_put_mutex(&opp->kref, _opp_kref_release, &opp->opp_table->lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put);
static void dev_pm_opp_put_unlocked(struct dev_pm_opp *opp)
{
kref_put(&opp->kref, _opp_kref_release_unlocked);
}
/**
* dev_pm_opp_remove() - Remove an OPP from OPP table
* @dev: device for which we do this operation
@ -1343,30 +1324,49 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
bool dynamic)
{
struct dev_pm_opp *opp = NULL, *temp;
mutex_lock(&opp_table->lock);
list_for_each_entry(temp, &opp_table->opp_list, node) {
if (dynamic == temp->dynamic) {
opp = temp;
break;
}
}
mutex_unlock(&opp_table->lock);
return opp;
}
bool _opp_remove_all_static(struct opp_table *opp_table)
{
struct dev_pm_opp *opp, *tmp;
bool ret = true;
struct dev_pm_opp *opp;
mutex_lock(&opp_table->lock);
if (!opp_table->parsed_static_opps) {
ret = false;
goto unlock;
mutex_unlock(&opp_table->lock);
return false;
}
if (--opp_table->parsed_static_opps)
goto unlock;
list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
if (!opp->dynamic)
dev_pm_opp_put_unlocked(opp);
if (--opp_table->parsed_static_opps) {
mutex_unlock(&opp_table->lock);
return true;
}
unlock:
mutex_unlock(&opp_table->lock);
return ret;
/*
* Can't remove the OPP from under the lock, debugfs removal needs to
* happen lock less to avoid circular dependency issues.
*/
while ((opp = _opp_get_next(opp_table, false)))
dev_pm_opp_put(opp);
return true;
}
/**
@ -1378,21 +1378,21 @@ unlock:
void dev_pm_opp_remove_all_dynamic(struct device *dev)
{
struct opp_table *opp_table;
struct dev_pm_opp *opp, *temp;
struct dev_pm_opp *opp;
int count = 0;
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return;
mutex_lock(&opp_table->lock);
list_for_each_entry_safe(opp, temp, &opp_table->opp_list, node) {
if (opp->dynamic) {
dev_pm_opp_put_unlocked(opp);
count++;
}
/*
* Can't remove the OPP from under the lock, debugfs removal needs to
* happen lock less to avoid circular dependency issues.
*/
while ((opp = _opp_get_next(opp_table, true))) {
dev_pm_opp_put(opp);
count++;
}
mutex_unlock(&opp_table->lock);
/* Drop the references taken by dev_pm_opp_add() */
while (count--)