Merge branch 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm

Pull operating performance points (OPP) framework updates for v5.6
from Viresh Kumar:

"This  contains a single patchset to fix reference counting of OPP
 table structures."

* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  opp: Replace list_kref with a local counter
  opp: Free static OPPs on errors while adding them

drivers/opp/core.c

@@ -988,7 +988,6 @@ static struct opp_table *_allocate_opp_table(struct device *dev, int index)
 	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
 	INIT_LIST_HEAD(&opp_table->opp_list);
 	kref_init(&opp_table->kref);
-	kref_init(&opp_table->list_kref);
 
 	/* Secure the device table modification */
 	list_add(&opp_table->node, &opp_tables);
@@ -1072,33 +1071,6 @@ static void _opp_table_kref_release(struct kref *kref)
 	mutex_unlock(&opp_table_lock);
 }
 
-void _opp_remove_all_static(struct opp_table *opp_table)
-{
-	struct dev_pm_opp *opp, *tmp;
-
-	list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
-		if (!opp->dynamic)
-			dev_pm_opp_put(opp);
-	}
-
-	opp_table->parsed_static_opps = false;
-}
-
-static void _opp_table_list_kref_release(struct kref *kref)
-{
-	struct opp_table *opp_table = container_of(kref, struct opp_table,
-						   list_kref);
-
-	_opp_remove_all_static(opp_table);
-	mutex_unlock(&opp_table_lock);
-}
-
-void _put_opp_list_kref(struct opp_table *opp_table)
-{
-	kref_put_mutex(&opp_table->list_kref, _opp_table_list_kref_release,
-		       &opp_table_lock);
-}
-
 void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
 {
 	kref_put_mutex(&opp_table->kref, _opp_table_kref_release,
@@ -1202,6 +1174,24 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 
+void _opp_remove_all_static(struct opp_table *opp_table)
+{
+	struct dev_pm_opp *opp, *tmp;
+
+	mutex_lock(&opp_table->lock);
+
+	if (!opp_table->parsed_static_opps || --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);
+	}
+
+unlock:
+	mutex_unlock(&opp_table->lock);
+}
+
 /**
  * dev_pm_opp_remove_all_dynamic() - Remove all dynamically created OPPs
  * @dev:	device for which we do this operation
@@ -2276,7 +2266,7 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev)
 		return;
 	}
 
-	_put_opp_list_kref(opp_table);
+	_opp_remove_all_static(opp_table);
 
 	/* Drop reference taken by _find_opp_table() */
 	dev_pm_opp_put_opp_table(opp_table);

drivers/opp/of.c

@@ -658,17 +658,15 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 	struct dev_pm_opp *opp;
 
 	/* OPP table is already initialized for the device */
+	mutex_lock(&opp_table->lock);
 	if (opp_table->parsed_static_opps) {
-		kref_get(&opp_table->list_kref);
+		opp_table->parsed_static_opps++;
+		mutex_unlock(&opp_table->lock);
 		return 0;
 	}
 
-	/*
-	 * Re-initialize list_kref every time we add static OPPs to the OPP
-	 * table as the reference count may be 0 after the last tie static OPPs
-	 * were removed.
-	 */
-	kref_init(&opp_table->list_kref);
+	opp_table->parsed_static_opps = 1;
+	mutex_unlock(&opp_table->lock);
 
 	/* We have opp-table node now, iterate over it and add OPPs */
 	for_each_available_child_of_node(opp_table->np, np) {
@@ -678,15 +676,17 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 				ret);
 			of_node_put(np);
-			return ret;
+			goto remove_static_opp;
 		} else if (opp) {
 			count++;
 		}
 	}
 
 	/* There should be one of more OPP defined */
-	if (WARN_ON(!count))
-		return -ENOENT;
+	if (WARN_ON(!count)) {
+		ret = -ENOENT;
+		goto remove_static_opp;
+	}
 
 	list_for_each_entry(opp, &opp_table->opp_list, node)
 		pstate_count += !!opp->pstate;
@@ -695,15 +695,19 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 	if (pstate_count && pstate_count != count) {
 		dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
 			count, pstate_count);
-		return -ENOENT;
+		ret = -ENOENT;
+		goto remove_static_opp;
 	}
 
 	if (pstate_count)
 		opp_table->genpd_performance_state = true;
 
-	opp_table->parsed_static_opps = true;
-
 	return 0;
+
+remove_static_opp:
+	_opp_remove_all_static(opp_table);
+
+	return ret;
 }
 
 /* Initializes OPP tables based on old-deprecated bindings */
@@ -738,6 +742,7 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 		if (ret) {
 			dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 				__func__, freq, ret);
+			_opp_remove_all_static(opp_table);
 			return ret;
 		}
 		nr -= 2;

drivers/opp/opp.h

@@ -127,11 +127,10 @@ enum opp_table_access {
  * @dev_list:	list of devices that share these OPPs
  * @opp_list:	table of opps
  * @kref:	for reference count of the table.
- * @list_kref:	for reference count of the OPP list.
  * @lock:	mutex protecting the opp_list and dev_list.
  * @np:		struct device_node pointer for opp's DT node.
  * @clock_latency_ns_max: Max clock latency in nanoseconds.
- * @parsed_static_opps: True if OPPs are initialized from DT.
+ * @parsed_static_opps: Count of devices for which OPPs are initialized from DT.
  * @shared_opp: OPP is shared between multiple devices.
  * @suspend_opp: Pointer to OPP to be used during device suspend.
  * @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
@@ -167,7 +166,6 @@ struct opp_table {
 	struct list_head dev_list;
 	struct list_head opp_list;
 	struct kref kref;
-	struct kref list_kref;
 	struct mutex lock;
 
 	struct device_node *np;
@@ -176,7 +174,7 @@ struct opp_table {
 	/* For backward compatibility with v1 bindings */
 	unsigned int voltage_tolerance_v1;
 
-	bool parsed_static_opps;
+	unsigned int parsed_static_opps;
 	enum opp_table_access shared_opp;
 	struct dev_pm_opp *suspend_opp;