diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 401148016978..78176f7ccff3 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -686,18 +686,27 @@ static struct cxl_region_ref *alloc_region_ref(struct cxl_port *port,
 	return cxl_rr;
 }
 
-static void free_region_ref(struct cxl_region_ref *cxl_rr)
+static void cxl_rr_free_decoder(struct cxl_region_ref *cxl_rr)
 {
-	struct cxl_port *port = cxl_rr->port;
 	struct cxl_region *cxlr = cxl_rr->region;
 	struct cxl_decoder *cxld = cxl_rr->decoder;
 
+	if (!cxld)
+		return;
+
 	dev_WARN_ONCE(&cxlr->dev, cxld->region != cxlr, "region mismatch\n");
 	if (cxld->region == cxlr) {
 		cxld->region = NULL;
 		put_device(&cxlr->dev);
 	}
+}
 
+static void free_region_ref(struct cxl_region_ref *cxl_rr)
+{
+	struct cxl_port *port = cxl_rr->port;
+	struct cxl_region *cxlr = cxl_rr->region;
+
+	cxl_rr_free_decoder(cxl_rr);
 	xa_erase(&port->regions, (unsigned long)cxlr);
 	xa_destroy(&cxl_rr->endpoints);
 	kfree(cxl_rr);
@@ -728,6 +737,83 @@ static int cxl_rr_ep_add(struct cxl_region_ref *cxl_rr,
 	return 0;
 }
 
+static int cxl_rr_alloc_decoder(struct cxl_port *port, struct cxl_region *cxlr,
+				struct cxl_endpoint_decoder *cxled,
+				bool *nr_targets_inc)
+{
+	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+	struct cxl_ep *ep = cxl_ep_load(port, cxlmd);
+	struct cxl_region_ref *cxl_rr;
+	struct cxl_decoder *cxld;
+	unsigned long index;
+
+	cxl_rr = cxl_rr_load(port, cxlr);
+	if (cxl_rr) {
+		struct cxl_ep *ep_iter;
+		int found = 0;
+
+		/*
+		 * Walk the existing endpoints that have been attached to
+		 * @cxlr at @port and see if they share the same 'next' port
+		 * in the downstream direction. I.e. endpoints that share common
+		 * upstream switch.
+		 */
+		xa_for_each(&cxl_rr->endpoints, index, ep_iter) {
+			if (ep_iter == ep)
+				continue;
+			if (ep_iter->next == ep->next) {
+				found++;
+				break;
+			}
+		}
+
+		/*
+		 * New target port, or @port is an endpoint port that always
+		 * accounts its own local decode as a target.
+		 */
+		if (!found || !ep->next) {
+			cxl_rr->nr_targets++;
+			*nr_targets_inc = true;
+		}
+
+		/*
+		 * The decoder for @cxlr was allocated when the region was first
+		 * attached to @port.
+		 */
+		cxld = cxl_rr->decoder;
+	} else {
+		cxl_rr = alloc_region_ref(port, cxlr);
+		if (IS_ERR(cxl_rr)) {
+			dev_dbg(&cxlr->dev,
+				"%s: failed to allocate region reference\n",
+				dev_name(&port->dev));
+			return PTR_ERR(cxl_rr);
+		}
+		*nr_targets_inc = true;
+
+		if (port == cxled_to_port(cxled))
+			cxld = &cxled->cxld;
+		else
+			cxld = cxl_region_find_decoder(port, cxlr);
+		if (!cxld) {
+			dev_dbg(&cxlr->dev, "%s: no decoder available\n",
+				dev_name(&port->dev));
+			return -ENXIO;
+		}
+
+		if (cxld->region) {
+			dev_dbg(&cxlr->dev, "%s: %s already attached to %s\n",
+				dev_name(&port->dev), dev_name(&cxld->dev),
+				dev_name(&cxld->region->dev));
+			return -EBUSY;
+		}
+
+		cxl_rr->decoder = cxld;
+	}
+
+	return 0;
+}
+
 /**
  * cxl_port_attach_region() - track a region's interest in a port by endpoint
  * @port: port to add a new region reference 'struct cxl_region_ref'
@@ -761,75 +847,23 @@ static int cxl_port_attach_region(struct cxl_port *port,
 	struct cxl_region_ref *cxl_rr;
 	bool nr_targets_inc = false;
 	struct cxl_decoder *cxld;
-	unsigned long index;
 	int rc = -EBUSY;
 
 	lockdep_assert_held_write(&cxl_region_rwsem);
 
+	rc = cxl_rr_alloc_decoder(port, cxlr, cxled, &nr_targets_inc);
+	if (rc)
+		goto out_erase;
+
 	cxl_rr = cxl_rr_load(port, cxlr);
-	if (cxl_rr) {
-		struct cxl_ep *ep_iter;
-		int found = 0;
-
-		/*
-		 * Walk the existing endpoints that have been attached to
-		 * @cxlr at @port and see if they share the same 'next' port
-		 * in the downstream direction. I.e. endpoints that share common
-		 * upstream switch.
-		 */
-		xa_for_each(&cxl_rr->endpoints, index, ep_iter) {
-			if (ep_iter == ep)
-				continue;
-			if (ep_iter->next == ep->next) {
-				found++;
-				break;
-			}
-		}
-
-		/*
-		 * New target port, or @port is an endpoint port that always
-		 * accounts its own local decode as a target.
-		 */
-		if (!found || !ep->next) {
-			cxl_rr->nr_targets++;
-			nr_targets_inc = true;
-		}
-
-		/*
-		 * The decoder for @cxlr was allocated when the region was first
-		 * attached to @port.
-		 */
-		cxld = cxl_rr->decoder;
-	} else {
-		cxl_rr = alloc_region_ref(port, cxlr);
-		if (IS_ERR(cxl_rr)) {
-			dev_dbg(&cxlr->dev,
-				"%s: failed to allocate region reference\n",
-				dev_name(&port->dev));
-			return PTR_ERR(cxl_rr);
-		}
-		nr_targets_inc = true;
-
-		if (port == cxled_to_port(cxled))
-			cxld = &cxled->cxld;
-		else
-			cxld = cxl_region_find_decoder(port, cxlr);
-		if (!cxld) {
-			dev_dbg(&cxlr->dev, "%s: no decoder available\n",
-				dev_name(&port->dev));
-			goto out_erase;
-		}
-
-		if (cxld->region) {
-			dev_dbg(&cxlr->dev, "%s: %s already attached to %s\n",
-				dev_name(&port->dev), dev_name(&cxld->dev),
-				dev_name(&cxld->region->dev));
-			rc = -EBUSY;
-			goto out_erase;
-		}
-
-		cxl_rr->decoder = cxld;
+	if (!cxl_rr) {
+		dev_dbg(&cxlr->dev,
+			"%s: expected to find a region reference but failed\n",
+			dev_name(&port->dev));
+		rc = -ENXIO;
+		goto out_erase;
 	}
+	cxld = cxl_rr->decoder;
 
 	rc = cxl_rr_ep_add(cxl_rr, cxled);
 	if (rc) {
