[PATCH 04/10] OPP: Break _opp_add_dynamic() into smaller functions

Viresh Kumar
2015-06-15T11:58:11Z

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.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/base/power/opp.c | 115 +++++++++++++++++++++++++++++------------------
1 file changed, 71 insertions(+), 44 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 4b646f36f252..2ac48ff9c1ef 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -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.
*
@@ -492,13 +493,14 @@ 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.
*/
- srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
+ 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 +546,65 @@ 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 = NULL;
+ struct list_head *head = &dev_opp->opp_list;
+
+ /*
+ * Insert new OPP in order of increasing frequency
+ * and discard if already present
+ */
+ list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
+ if (new_opp->rate <= opp->rate)
+ break;
+
+ head = &opp->node;
+ }
+
+ /* Duplicate OPPs ? */
+ if (opp && new_opp->rate == opp->rate) {
+ 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
@@ -581,55 +636,28 @@ 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 = NULL, *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;
+ ret = _opp_add(new_opp, dev_opp);
+ if (ret)
goto free_opp;
- }
-
- /*
- * Insert new OPP in order of increasing frequency
- * and discard if already present
- */
- head = &dev_opp->opp_list;
- list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
- if (new_opp->rate <= opp->rate)
- break;
- else
- head = &opp->node;
- }
-
- /* Duplicate OPPs ? */
- if (opp && new_opp->rate == opp->rate) {
- 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);
- goto remove_dev_opp;
- }

- new_opp->dynamic = dynamic;
- new_opp->dev_opp = dev_opp;
- list_add_rcu(&new_opp->node, head);
mutex_unlock(&dev_opp_list_lock);

/*
@@ -639,11 +667,10 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADD, new_opp);
return 0;

-remove_dev_opp:
- _remove_device_opp(dev_opp);
free_opp:
+ _opp_remove(dev_opp, new_opp, false);
+unlock:
mutex_unlock(&dev_opp_list_lock);
- kfree(new_opp);
return ret;
}

@@ -871,7 +898,7 @@ 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);
--
2.4.0