3 files changed, 96 insertions, 1 deletions

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 9d5404a07e8a..1a41e59c77f8 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -20,6 +20,8 @@
 
 #include "internal.h"
 
+#define ICC_DYN_ID_START 10000
+
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
@@ -826,7 +828,12 @@ static struct icc_node *icc_node_create_nolock(int id)
 	if (!node)
 		return ERR_PTR(-ENOMEM);
 
-	id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
+	/* dynamic id allocation */
+	if (id == ICC_ALLOC_DYN_ID)
+		id = idr_alloc(&icc_idr, node, ICC_DYN_ID_START, 0, GFP_KERNEL);
+	else
+		id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
+
 	if (id < 0) {
 		WARN(1, "%s: couldn't get idr\n", __func__);
 		kfree(node);
@@ -839,6 +846,25 @@ static struct icc_node *icc_node_create_nolock(int id)
 }
 
 /**
+ * icc_node_create_dyn() - create a node with dynamic id
+ *
+ * Return: icc_node pointer on success, or ERR_PTR() on error
+ */
+struct icc_node *icc_node_create_dyn(void)
+{
+	struct icc_node *node;
+
+	mutex_lock(&icc_lock);
+
+	node = icc_node_create_nolock(ICC_ALLOC_DYN_ID);
+
+	mutex_unlock(&icc_lock);
+
+	return node;
+}
+EXPORT_SYMBOL_GPL(icc_node_create_dyn);
+
+/**
  * icc_node_create() - create a node
  * @id: node id
  *
@@ -885,6 +911,56 @@ void icc_node_destroy(int id)
 EXPORT_SYMBOL_GPL(icc_node_destroy);
 
 /**
+ * icc_link_nodes() - create link between two nodes
+ * @src_node: source node
+ * @dst_node: destination node
+ *
+ * Create a link between two nodes. The nodes might belong to different
+ * interconnect providers and the @dst_node might not exist (if the
+ * provider driver has not probed yet). So just create the @dst_node
+ * and when the actual provider driver is probed, the rest of the node
+ * data is filled.
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_link_nodes(struct icc_node *src_node, struct icc_node **dst_node)
+{
+	struct icc_node **new;
+	int ret = 0;
+
+	if (!src_node->provider)
+		return -EINVAL;
+
+	mutex_lock(&icc_lock);
+
+	if (!*dst_node) {
+		*dst_node = icc_node_create_nolock(ICC_ALLOC_DYN_ID);
+
+		if (IS_ERR(*dst_node)) {
+			ret = PTR_ERR(*dst_node);
+			goto out;
+		}
+	}
+
+	new = krealloc(src_node->links,
+		       (src_node->num_links + 1) * sizeof(*src_node->links),
+		       GFP_KERNEL);
+	if (!new) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	src_node->links = new;
+	src_node->links[src_node->num_links++] = *dst_node;
+
+out:
+	mutex_unlock(&icc_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(icc_link_nodes);
+
+/**
  * icc_link_create() - create a link between two nodes
  * @node: source node id
  * @dst_id: destination node id
@@ -962,6 +1038,10 @@ void icc_node_add(struct icc_node *node, struct icc_provider *provider)
 	node->avg_bw = node->init_avg;
 	node->peak_bw = node->init_peak;
 
+	if (node->id >= ICC_DYN_ID_START)
+		node->name = devm_kasprintf(provider->dev, GFP_KERNEL, "%s@%s",
+					    node->name, dev_name(provider->dev));
+
 	if (node->avg_bw || node->peak_bw) {
 		if (provider->pre_aggregate)
 			provider->pre_aggregate(node);
diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
index f5aef8784692..55cfebc658e6 100644
--- a/include/linux/interconnect-provider.h
+++ b/include/linux/interconnect-provider.h
@@ -116,8 +116,10 @@ struct icc_node {
 
 int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
 		      u32 peak_bw, u32 *agg_avg, u32 *agg_peak);
+struct icc_node *icc_node_create_dyn(void);
 struct icc_node *icc_node_create(int id);
 void icc_node_destroy(int id);
+int icc_link_nodes(struct icc_node *src_node, struct icc_node **dst_node);
 int icc_link_create(struct icc_node *node, const int dst_id);
 void icc_node_add(struct icc_node *node, struct icc_provider *provider);
 void icc_node_del(struct icc_node *node);
@@ -136,6 +138,11 @@ static inline int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
 	return -ENOTSUPP;
 }
 
+static inline struct icc_node *icc_node_create_dyn(void)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
 static inline struct icc_node *icc_node_create(int id)
 {
 	return ERR_PTR(-ENOTSUPP);
@@ -145,6 +152,11 @@ static inline void icc_node_destroy(int id)
 {
 }
 
+static inline int icc_link_nodes(struct icc_node *src_node, struct icc_node **dst_node)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int icc_link_create(struct icc_node *node, const int dst_id)
 {
 	return -ENOTSUPP;
diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
index 97ac253df62c..e4b8808823ad 100644
--- a/include/linux/interconnect.h
+++ b/include/linux/interconnect.h
@@ -20,6 +20,9 @@
 #define Mbps_to_icc(x)	((x) * 1000 / 8)
 #define Gbps_to_icc(x)	((x) * 1000 * 1000 / 8)
 
+/* macro to indicate dynamic id allocation */
+#define ICC_ALLOC_DYN_ID	-1
+
 struct icc_path;
 struct device;