Merge branch 'icc-debugfs' into icc-next

This series introduces interconnect debugfs files that support voting
for any interconnect path the framework supports. It is useful for debug,
test and verification.

* icc-debugfs
  debugfs: Add write support to debugfs_create_str()
  interconnect: Reintroduce icc_get()
  interconnect: Add debugfs test client

Link: https://lore.kernel.org/r/20230807142914.12480-1-quic_mdtipton@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 1afbc4f7c6e7..dfab160ca529 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -148,6 +148,21 @@ static struct icc_node *node_find(const int id)
 	return idr_find(&icc_idr, id);
 }
 
+static struct icc_node *node_find_by_name(const char *name)
+{
+	struct icc_provider *provider;
+	struct icc_node *n;
+
+	list_for_each_entry(provider, &icc_providers, provider_list) {
+		list_for_each_entry(n, &provider->nodes, node_list) {
+			if (!strcmp(n->name, name))
+				return n;
+		}
+	}
+
+	return NULL;
+}
+
 static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
 				  ssize_t num_nodes)
 {
@@ -563,6 +578,54 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
 EXPORT_SYMBOL_GPL(of_icc_get);
 
 /**
+ * icc_get() - get a path handle between two endpoints
+ * @dev: device pointer for the consumer device
+ * @src: source node name
+ * @dst: destination node name
+ *
+ * This function will search for a path between two endpoints and return an
+ * icc_path handle on success. Use icc_put() to release constraints when they
+ * are not needed anymore.
+ *
+ * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
+ * when the API is disabled.
+ */
+struct icc_path *icc_get(struct device *dev, const char *src, const char *dst)
+{
+	struct icc_node *src_node, *dst_node;
+	struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+
+	mutex_lock(&icc_lock);
+
+	src_node = node_find_by_name(src);
+	if (!src_node) {
+		dev_err(dev, "%s: invalid src=%s\n", __func__, src);
+		goto out;
+	}
+
+	dst_node = node_find_by_name(dst);
+	if (!dst_node) {
+		dev_err(dev, "%s: invalid dst=%s\n", __func__, dst);
+		goto out;
+	}
+
+	path = path_find(dev, src_node, dst_node);
+	if (IS_ERR(path)) {
+		dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
+		goto out;
+	}
+
+	path->name = kasprintf(GFP_KERNEL, "%s-%s", src_node->name, dst_node->name);
+	if (!path->name) {
+		kfree(path);
+		path = ERR_PTR(-ENOMEM);
+	}
+out:
+	mutex_unlock(&icc_lock);
+	return path;
+}
+
+/**
  * icc_set_tag() - set an optional tag on a path
  * @path: the path we want to tag
  * @tag: the tag value
@@ -1065,6 +1128,9 @@ static int __init icc_init(void)
 			    icc_debugfs_dir, NULL, &icc_summary_fops);
 	debugfs_create_file("interconnect_graph", 0444,
 			    icc_debugfs_dir, NULL, &icc_graph_fops);
+
+	icc_debugfs_client_init(icc_debugfs_dir);
+
 	return 0;
 }