interconnect: Add a name to struct icc_path

When debugging interconnect things, it turned out that saving the path
name and including it in the traces is quite useful, especially for
devices with multiple paths.

For the path name we use the one specified in DT, or if we use platform
data, the name is based on the source and destination node names.

Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index f30a326dc7ce5ef43fb0b3d499a5267292e8ca1d..4f9bdb7f9165e334b489d811fd6e155bffd7a771 100644 (file)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -356,9 +356,17 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
 
        mutex_lock(&icc_lock);
        path = path_find(dev, src_node, dst_node);
-       if (IS_ERR(path))
-               dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
        mutex_unlock(&icc_lock);
+       if (IS_ERR(path)) {
+               dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
+               return path;
+       }
+
+       if (name)
+               path->name = kstrdup_const(name, GFP_KERNEL);
+       else
+               path->name = kasprintf(GFP_KERNEL, "%s-%s",
+                                      src_node->name, dst_node->name);
 
        return path;
 }
@@ -481,9 +489,12 @@ struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
                goto out;
 
        path = path_find(dev, src, dst);
-       if (IS_ERR(path))
+       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->name, dst->name);
 out:
        mutex_unlock(&icc_lock);
        return path;
@@ -519,6 +530,7 @@ void icc_put(struct icc_path *path)
        }
        mutex_unlock(&icc_lock);
 
+       kfree_const(path->name);
        kfree(path);
 }
 EXPORT_SYMBOL_GPL(icc_put);

diff --git a/drivers/interconnect/internal.h b/drivers/interconnect/internal.h
index 5853e8faf223af0ca7323a627daa87eb3d51b99c..bf18cb7239df839a272e80223f624c9a220750c2 100644 (file)
--- a/drivers/interconnect/internal.h
+++ b/drivers/interconnect/internal.h
@@ -29,10 +29,12 @@ struct icc_req {
 
 /**
  * struct icc_path - interconnect path structure
+ * @name: a string name of the path (useful for ftrace)
  * @num_nodes: number of hops (nodes)
  * @reqs: array of the requests applicable to this path of nodes
  */
 struct icc_path {
+       const char *name;
        size_t num_nodes;
        struct icc_req reqs[];
 };