cxl/port: Split endpoint and switch port probe

Jonathan points out that the shared code between the switch and endpoint
case is small. Before adding another is_cxl_endpoint() conditional,
just split the two cases.

Rather than duplicate the "Couldn't enumerate decoders" error message
take the opportunity to improve the error messages in
devm_cxl_enumerate_decoders().

Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/167601999378.1924368.15071142145866277623.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/hdm.c

@@ -826,7 +826,8 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 			cxled = cxl_endpoint_decoder_alloc(port);
 			if (IS_ERR(cxled)) {
 				dev_warn(&port->dev,
-					 "Failed to allocate the decoder\n");
+					 "Failed to allocate decoder%d.%d\n",
+					 port->id, i);
 				return PTR_ERR(cxled);
 			}
 			cxld = &cxled->cxld;
@@ -836,21 +837,25 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 			cxlsd = cxl_switch_decoder_alloc(port, target_count);
 			if (IS_ERR(cxlsd)) {
 				dev_warn(&port->dev,
-					 "Failed to allocate the decoder\n");
+					 "Failed to allocate decoder%d.%d\n",
+					 port->id, i);
 				return PTR_ERR(cxlsd);
 			}
 			cxld = &cxlsd->cxld;
 		}
 
 		rc = init_hdm_decoder(port, cxld, target_map, hdm, i, &dpa_base);
 		if (rc) {
+			dev_warn(&port->dev,
+				 "Failed to initialize decoder%d.%d\n",
+				 port->id, i);
 			put_device(&cxld->dev);
 			return rc;
 		}
 		rc = add_hdm_decoder(port, cxld, target_map);
 		if (rc) {
 			dev_warn(&port->dev,
-				 "Failed to add decoder to port\n");
+				 "Failed to add decoder%d.%d\n", port->id, i);
 			return rc;
 		}
 	}

drivers/cxl/port.c

@@ -30,55 +30,64 @@ static void schedule_detach(void *cxlmd)
 	schedule_cxl_memdev_detach(cxlmd);
 }
 
-static int cxl_port_probe(struct device *dev)
+static int cxl_switch_port_probe(struct cxl_port *port)
 {
-	struct cxl_port *port = to_cxl_port(dev);
 	struct cxl_hdm *cxlhdm;
 	int rc;
 
+	rc = devm_cxl_port_enumerate_dports(port);
+	if (rc < 0)
+		return rc;
 
-	if (!is_cxl_endpoint(port)) {
-		rc = devm_cxl_port_enumerate_dports(port);
-		if (rc < 0)
-			return rc;
-		if (rc == 1)
-			return devm_cxl_add_passthrough_decoder(port);
-	}
+	if (rc == 1)
+		return devm_cxl_add_passthrough_decoder(port);
 
 	cxlhdm = devm_cxl_setup_hdm(port);
 	if (IS_ERR(cxlhdm))
 		return PTR_ERR(cxlhdm);
 
-	if (is_cxl_endpoint(port)) {
-		struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport);
-		struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	return devm_cxl_enumerate_decoders(cxlhdm);
+}
 
-		/* Cache the data early to ensure is_visible() works */
-		read_cdat_data(port);
+static int cxl_endpoint_port_probe(struct cxl_port *port)
+{
+	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct cxl_hdm *cxlhdm;
+	int rc;
+
+	cxlhdm = devm_cxl_setup_hdm(port);
+	if (IS_ERR(cxlhdm))
+		return PTR_ERR(cxlhdm);
 
-		get_device(&cxlmd->dev);
-		rc = devm_add_action_or_reset(dev, schedule_detach, cxlmd);
-		if (rc)
-			return rc;
+	/* Cache the data early to ensure is_visible() works */
+	read_cdat_data(port);
 
-		rc = cxl_hdm_decode_init(cxlds, cxlhdm);
-		if (rc)
-			return rc;
+	get_device(&cxlmd->dev);
+	rc = devm_add_action_or_reset(&port->dev, schedule_detach, cxlmd);
+	if (rc)
+		return rc;
 
-		rc = cxl_await_media_ready(cxlds);
-		if (rc) {
-			dev_err(dev, "Media not active (%d)\n", rc);
-			return rc;
-		}
-	}
+	rc = cxl_hdm_decode_init(cxlds, cxlhdm);
+	if (rc)
+		return rc;
 
-	rc = devm_cxl_enumerate_decoders(cxlhdm);
+	rc = cxl_await_media_ready(cxlds);
 	if (rc) {
-		dev_err(dev, "Couldn't enumerate decoders (%d)\n", rc);
+		dev_err(&port->dev, "Media not active (%d)\n", rc);
 		return rc;
 	}
 
-	return 0;
+	return devm_cxl_enumerate_decoders(cxlhdm);
+}
+
+static int cxl_port_probe(struct device *dev)
+{
+	struct cxl_port *port = to_cxl_port(dev);
+
+	if (is_cxl_endpoint(port))
+		return cxl_endpoint_port_probe(port);
+	return cxl_switch_port_probe(port);
 }
 
 static ssize_t CDAT_read(struct file *filp, struct kobject *kobj,