interconnect: Introduce xlate_extended() callback

Currently there is the xlate() callback, which is used by providers for
mapping the nodes from phandle arguments. That's fine for simple mappings,
but the phandle arguments could contain an additional data, such as tag
information. Let's create another callback xlate_extended() for the cases
where providers want also populate the path tag data.
Tested-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20200903133134.17201-2-georgi.djakov@linaro.orgSigned-off-by: Georgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/core.c

@@ -342,12 +342,13 @@ EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
  * Looks for interconnect provider under the node specified by @spec and if
  * found, uses xlate function of the provider to map phandle args to node.
  *
- * Returns a valid pointer to struct icc_node on success or ERR_PTR()
+ * Returns a valid pointer to struct icc_node_data on success or ERR_PTR()
  * on failure.
  */
-struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
+struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
 {
 	struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
+	struct icc_node_data *data = NULL;
 	struct icc_provider *provider;
 
 	if (!spec)
@@ -355,14 +356,33 @@ struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
 
 	mutex_lock(&icc_lock);
 	list_for_each_entry(provider, &icc_providers, provider_list) {
-		if (provider->dev->of_node == spec->np)
-			node = provider->xlate(spec, provider->data);
-		if (!IS_ERR(node))
-			break;
+		if (provider->dev->of_node == spec->np) {
+			if (provider->xlate_extended) {
+				data = provider->xlate_extended(spec, provider->data);
+				if (!IS_ERR(data)) {
+					node = data->node;
+					break;
+				}
+			} else {
+				node = provider->xlate(spec, provider->data);
+				if (!IS_ERR(node))
+					break;
+			}
+		}
 	}
 	mutex_unlock(&icc_lock);
 
-	return node;
+	if (IS_ERR(node))
+		return ERR_CAST(node);
+
+	if (!data) {
+		data = kzalloc(sizeof(*data), GFP_KERNEL);
+		if (!data)
+			return ERR_PTR(-ENOMEM);
+		data->node = node;
+	}
+
+	return data;
 }
 EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
 
@@ -409,7 +429,7 @@ EXPORT_SYMBOL_GPL(devm_of_icc_get);
 struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
 {
 	struct icc_path *path;
-	struct icc_node *src_node, *dst_node;
+	struct icc_node_data *src_data, *dst_data;
 	struct device_node *np;
 	struct of_phandle_args src_args, dst_args;
 	int ret;
@@ -447,39 +467,46 @@ struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
 
 	of_node_put(dst_args.np);
 
-	src_node = of_icc_get_from_provider(&src_args);
+	src_data = of_icc_get_from_provider(&src_args);
 
-	if (IS_ERR(src_node)) {
-		if (PTR_ERR(src_node) != -EPROBE_DEFER)
+	if (IS_ERR(src_data)) {
+		if (PTR_ERR(src_data) != -EPROBE_DEFER)
 			dev_err(dev, "error finding src node: %ld\n",
-				PTR_ERR(src_node));
-		return ERR_CAST(src_node);
+				PTR_ERR(src_data));
+		return ERR_CAST(src_data);
 	}
 
-	dst_node = of_icc_get_from_provider(&dst_args);
+	dst_data = of_icc_get_from_provider(&dst_args);
 
-	if (IS_ERR(dst_node)) {
-		if (PTR_ERR(dst_node) != -EPROBE_DEFER)
+	if (IS_ERR(dst_data)) {
+		if (PTR_ERR(dst_data) != -EPROBE_DEFER)
 			dev_err(dev, "error finding dst node: %ld\n",
-				PTR_ERR(dst_node));
-		return ERR_CAST(dst_node);
+				PTR_ERR(dst_data));
+		kfree(src_data);
+		return ERR_CAST(dst_data);
 	}
 
 	mutex_lock(&icc_lock);
-	path = path_find(dev, src_node, dst_node);
+	path = path_find(dev, src_data->node, dst_data->node);
 	mutex_unlock(&icc_lock);
 	if (IS_ERR(path)) {
 		dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
-		return path;
+		goto free_icc_data;
 	}
 
+	if (src_data->tag && src_data->tag == dst_data->tag)
+		icc_set_tag(path, src_data->tag);
+
 	path->name = kasprintf(GFP_KERNEL, "%s-%s",
-			       src_node->name, dst_node->name);
+			       src_data->node->name, dst_data->node->name);
 	if (!path->name) {
 		kfree(path);
-		return ERR_PTR(-ENOMEM);
+		path = ERR_PTR(-ENOMEM);
 	}
 
+free_icc_data:
+	kfree(src_data);
+	kfree(dst_data);
 	return path;
 }
 EXPORT_SYMBOL_GPL(of_icc_get_by_index);
@@ -981,7 +1008,7 @@ int icc_provider_add(struct icc_provider *provider)
 {
 	if (WARN_ON(!provider->set))
 		return -EINVAL;
-	if (WARN_ON(!provider->xlate))
+	if (WARN_ON(!provider->xlate && !provider->xlate_extended))
 		return -EINVAL;
 
 	mutex_lock(&icc_lock);

include/linux/interconnect-provider.h

@@ -14,6 +14,17 @@
 struct icc_node;
 struct of_phandle_args;
 
+/**
+ * struct icc_node_data - icc node data
+ *
+ * @node: icc node
+ * @tag: tag
+ */
+struct icc_node_data {
+	struct icc_node *node;
+	u32 tag;
+};
+
 /**
  * struct icc_onecell_data - driver data for onecell interconnect providers
  *
@@ -39,6 +50,7 @@ struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
  * @pre_aggregate: pointer to device specific function that is called
  *		   before the aggregation begins (optional)
  * @xlate: provider-specific callback for mapping nodes from phandle arguments
+ * @xlate_extended: vendor-specific callback for mapping node data from phandle arguments
  * @dev: the device this interconnect provider belongs to
  * @users: count of active users
  * @inter_set: whether inter-provider pairs will be configured with @set
@@ -52,6 +64,7 @@ struct icc_provider {
 			 u32 peak_bw, u32 *agg_avg, u32 *agg_peak);
 	void (*pre_aggregate)(struct icc_node *node);
 	struct icc_node* (*xlate)(struct of_phandle_args *spec, void *data);
+	struct icc_node_data* (*xlate_extended)(struct of_phandle_args *spec, void *data);
 	struct device		*dev;
 	int			users;
 	bool			inter_set;
@@ -105,7 +118,7 @@ void icc_node_del(struct icc_node *node);
 int icc_nodes_remove(struct icc_provider *provider);
 int icc_provider_add(struct icc_provider *provider);
 int icc_provider_del(struct icc_provider *provider);
-struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec);
+struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec);
 
 #else
 
@@ -157,7 +170,7 @@ static inline int icc_provider_del(struct icc_provider *provider)
 	return -ENOTSUPP;
 }
 
-static inline struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
+static inline struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
 {
 	return ERR_PTR(-ENOTSUPP);
 }