interconnect: core: Add dynamic id allocation support

The current interconnect framework relies on static IDs for node
creation and registration, which limits topologies with multiple
instances of the same interconnect provider. To address this,
introduce icc_node_create_dyn() and icc_link_nodes() APIs to
dynamically allocate IDs for interconnect nodes during creation
and link. This change removes the dependency on static IDs,
allowing multiple instances of the same hardware, such as EPSS L3.

Signed-off-by: Raviteja Laggyshetty <quic_rlaggysh@quicinc.com>
Link: https://lore.kernel.org/r/20250415095343.32125-3-quic_rlaggysh@quicinc.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>

1 files changed, 81 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);