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Date: Wed, 7 Dec 2016 16:07:43 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Rafael Wysocki <rjw@...ysocki.net>,
Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
Stephen Boyd <sboyd@...eaurora.org>
Cc: linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
linux-kernel@...r.kernel.org,
Vincent Guittot <vincent.guittot@...aro.org>,
Viresh Kumar <viresh.kumar@...aro.org>
Subject: [PATCH 05/12] 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: Viresh Kumar <viresh.kumar@...aro.org>
---
drivers/base/power/opp/core.c | 63 ++++---------------------------------------
drivers/base/power/opp/of.c | 54 +++++++++++++++++--------------------
drivers/base/power/opp/opp.h | 1 -
3 files changed, 29 insertions(+), 89 deletions(-)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index aacca85ebd20..ec833a8f7aa5 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -863,27 +863,6 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
}
/**
- * _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);
@@ -1219,8 +1178,6 @@ 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(dev, opp_table);
if (!new_opp)
return -ENOMEM;
@@ -1641,21 +1598,13 @@ 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);
@@ -1866,8 +1815,6 @@ 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 */
diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c
index 38efc14d829c..a789dc228a6a 100644
--- a/drivers/base/power/opp/of.c
+++ b/drivers/base/power/opp/of.c
@@ -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;
}
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 596f361fbe70..8435a0eb27be 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -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);
--
2.7.1.410.g6faf27b
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