1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 1287778c3be5..86d1fc2c1bd4 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -1291,3 +1291,61 @@ void coresight_unregister(struct coresight_device *csdev)
 	device_unregister(&csdev->dev);
 }
 EXPORT_SYMBOL_GPL(coresight_unregister);
+
+
+/*
+ * coresight_search_device_idx - Search the fwnode handle of a device
+ * in the given dev_idx list. Must be called with the coresight_mutex held.
+ *
+ * Returns the index of the entry, when found. Otherwise, -ENOENT.
+ */
+static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
+					      struct fwnode_handle *fwnode)
+{
+	int i;
+
+	for (i = 0; i < dict->nr_idx; i++)
+		if (dict->fwnode_list[i] == fwnode)
+			return i;
+	return -ENOENT;
+}
+
+/*
+ * coresight_alloc_device_name - Get an index for a given device in the
+ * device index list specific to a driver. An index is allocated for a
+ * device and is tracked with the fwnode_handle to prevent allocating
+ * duplicate indices for the same device (e.g, if we defer probing of
+ * a device due to dependencies), in case the index is requested again.
+ */
+char *coresight_alloc_device_name(struct coresight_dev_list *dict,
+				  struct device *dev)
+{
+	int idx;
+	char *name = NULL;
+	struct fwnode_handle **list;
+
+	mutex_lock(&coresight_mutex);
+
+	idx = coresight_search_device_idx(dict, dev_fwnode(dev));
+	if (idx < 0) {
+		/* Make space for the new entry */
+		idx = dict->nr_idx;
+		list = krealloc(dict->fwnode_list,
+				(idx + 1) * sizeof(*dict->fwnode_list),
+				GFP_KERNEL);
+		if (ZERO_OR_NULL_PTR(list)) {
+			idx = -ENOMEM;
+			goto done;
+		}
+
+		list[idx] = dev_fwnode(dev);
+		dict->fwnode_list = list;
+		dict->nr_idx = idx + 1;
+	}
+
+	name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
+done:
+	mutex_unlock(&coresight_mutex);
+	return name;
+}
+EXPORT_SYMBOL_GPL(coresight_alloc_device_name);