X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=drivers%2Fopp%2Fcore.c;h=2319ad4a01776bf564dba2ab2f603c2cb6fc0a55;hb=2a4eb7358aba6beff7fa23f028c733310756e525;hp=31ff03dbeb83771be1ba57fde89ea6c32f63c2aa;hpb=7123fd41e35a2868cbc2fc611c15a745692b3d78;p=linux.git

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 31ff03dbeb83..2319ad4a0177 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -48,9 +48,14 @@ static struct opp_device *_find_opp_dev(const struct device *dev,
 static struct opp_table *_find_opp_table_unlocked(struct device *dev)
 {
 	struct opp_table *opp_table;
+	bool found;
 
 	list_for_each_entry(opp_table, &opp_tables, node) {
-		if (_find_opp_dev(dev, opp_table)) {
+		mutex_lock(&opp_table->lock);
+		found = !!_find_opp_dev(dev, opp_table);
+		mutex_unlock(&opp_table->lock);
+
+		if (found) {
 			_get_opp_table_kref(opp_table);
 
 			return opp_table;
@@ -766,6 +771,8 @@ struct opp_device *_add_opp_dev(const struct device *dev,
 
 	/* Initialize opp-dev */
 	opp_dev->dev = dev;
+
+	mutex_lock(&opp_table->lock);
 	list_add(&opp_dev->node, &opp_table->dev_list);
 
 	/* Create debugfs entries for the opp_table */
@@ -773,11 +780,12 @@ struct opp_device *_add_opp_dev(const struct device *dev,
 	if (ret)
 		dev_err(dev, "%s: Failed to register opp debugfs (%d)\n",
 			__func__, ret);
+	mutex_unlock(&opp_table->lock);
 
 	return opp_dev;
 }
 
-static struct opp_table *_allocate_opp_table(struct device *dev)
+static struct opp_table *_allocate_opp_table(struct device *dev, int index)
 {
 	struct opp_table *opp_table;
 	struct opp_device *opp_dev;
@@ -791,6 +799,7 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
 	if (!opp_table)
 		return NULL;
 
+	mutex_init(&opp_table->lock);
 	INIT_LIST_HEAD(&opp_table->dev_list);
 
 	opp_dev = _add_opp_dev(dev, opp_table);
@@ -799,7 +808,7 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
 		return NULL;
 	}
 
-	_of_init_opp_table(opp_table, dev);
+	_of_init_opp_table(opp_table, dev, index);
 
 	/* Find clk for the device */
 	opp_table->clk = clk_get(dev, NULL);
@@ -812,7 +821,6 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
 
 	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
 	INIT_LIST_HEAD(&opp_table->opp_list);
-	mutex_init(&opp_table->lock);
 	kref_init(&opp_table->kref);
 
 	/* Secure the device table modification */
@@ -825,7 +833,7 @@ void _get_opp_table_kref(struct opp_table *opp_table)
 	kref_get(&opp_table->kref);
 }
 
-struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
+static struct opp_table *_opp_get_opp_table(struct device *dev, int index)
 {
 	struct opp_table *opp_table;
 
@@ -836,15 +844,26 @@ struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
 	if (!IS_ERR(opp_table))
 		goto unlock;
 
-	opp_table = _allocate_opp_table(dev);
+	opp_table = _allocate_opp_table(dev, index);
 
 unlock:
 	mutex_unlock(&opp_table_lock);
 
 	return opp_table;
 }
+
+struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
+{
+	return _opp_get_opp_table(dev, 0);
+}
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
 
+struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *dev,
+						   int index)
+{
+	return _opp_get_opp_table(dev, index);
+}
+
 static void _opp_table_kref_release(struct kref *kref)
 {
 	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
@@ -854,6 +873,10 @@ static void _opp_table_kref_release(struct kref *kref)
 	if (!IS_ERR(opp_table->clk))
 		clk_put(opp_table->clk);
 
+	/*
+	 * No need to take opp_table->lock here as we are guaranteed that no
+	 * references to the OPP table are taken at this point.
+	 */
 	opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device,
 				   node);
 
@@ -869,6 +892,33 @@ 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,
@@ -896,7 +946,6 @@ static void _opp_kref_release(struct kref *kref)
 	kfree(opp);
 
 	mutex_unlock(&opp_table->lock);
-	dev_pm_opp_put_opp_table(opp_table);
 }
 
 void dev_pm_opp_get(struct dev_pm_opp *opp)
@@ -940,11 +989,15 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 
 	if (found) {
 		dev_pm_opp_put(opp);
+
+		/* Drop the reference taken by dev_pm_opp_add() */
+		dev_pm_opp_put_opp_table(opp_table);
 	} else {
 		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
 			 __func__, freq);
 	}
 
+	/* Drop the reference taken by _find_opp_table() */
 	dev_pm_opp_put_opp_table(opp_table);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
@@ -1062,9 +1115,6 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 	new_opp->opp_table = opp_table;
 	kref_init(&new_opp->kref);
 
-	/* Get a reference to the OPP table */
-	_get_opp_table_kref(opp_table);
-
 	ret = opp_debug_create_one(new_opp, opp_table);
 	if (ret)
 		dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
@@ -1543,8 +1593,9 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 		return -ENOMEM;
 
 	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
+	if (ret)
+		dev_pm_opp_put_opp_table(opp_table);
 
-	dev_pm_opp_put_opp_table(opp_table);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_add);
@@ -1708,21 +1759,17 @@ int dev_pm_opp_unregister_notifier(struct device *dev,
 EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
 
 /*
- * Free OPPs either created using static entries present in DT or even the
- * dynamically added entries based on remove_all param.
+ * Free OPPs either created using static entries present in DT.
  */
-void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev,
-			      bool remove_all)
+void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev)
 {
-	struct dev_pm_opp *opp, *tmp;
+	/* Protect dev_list */
+	mutex_lock(&opp_table->lock);
 
 	/* Find if opp_table manages a single device */
 	if (list_is_singular(&opp_table->dev_list)) {
 		/* Free static OPPs */
-		list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
-			if (remove_all || !opp->dynamic)
-				dev_pm_opp_put(opp);
-		}
+		_put_opp_list_kref(opp_table);
 
 		/*
 		 * The OPP table is getting removed, drop the performance state
@@ -1731,11 +1778,14 @@ void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev,
 		if (opp_table->genpd_performance_state)
 			dev_pm_genpd_set_performance_state(dev, 0);
 	} else {
+		_put_opp_list_kref(opp_table);
 		_remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
 	}
+
+	mutex_unlock(&opp_table->lock);
 }
 
-void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
+void _dev_pm_opp_find_and_remove_table(struct device *dev)
 {
 	struct opp_table *opp_table;
 
@@ -1752,7 +1802,7 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
 		return;
 	}
 
-	_dev_pm_opp_remove_table(opp_table, dev, remove_all);
+	_dev_pm_opp_remove_table(opp_table, dev);
 
 	dev_pm_opp_put_opp_table(opp_table);
 }
@@ -1766,6 +1816,6 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
  */
 void dev_pm_opp_remove_table(struct device *dev)
 {
-	_dev_pm_opp_find_and_remove_table(dev, true);
+	_dev_pm_opp_find_and_remove_table(dev);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);