cxl/port: Up-level cxl_add_dport() locking requirements to the caller

In preparation for moving dport enumeration into the core, require the
port device lock to be acquired by the caller.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164367759016.324231.105551648350470000.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/acpi.c

@@ -342,7 +342,9 @@ static int add_host_bridge_dport(struct device *match, void *arg)
 		return 0;
 	}
 
+	cxl_device_lock(&root_port->dev);
 	rc = cxl_add_dport(root_port, match, uid, ctx.chbcr);
+	cxl_device_unlock(&root_port->dev);
 	if (rc) {
 		dev_err(host, "failed to add downstream port: %s\n",
 			dev_name(match));

drivers/cxl/core/port.c

@@ -519,7 +519,7 @@ static int add_dport(struct cxl_port *port, struct cxl_dport *new)
 {
 	struct cxl_dport *dup;
 
-	cxl_device_lock(&port->dev);
+	device_lock_assert(&port->dev);
 	dup = find_dport(port, new->port_id);
 	if (dup)
 		dev_err(&port->dev,
@@ -528,7 +528,6 @@ static int add_dport(struct cxl_port *port, struct cxl_dport *new)
 			dev_name(dup->dport));
 	else
 		list_add_tail(&new->list, &port->dports);
-	cxl_device_unlock(&port->dev);
 
 	return dup ? -EEXIST : 0;
 }

tools/testing/cxl/mock_acpi.c

@@ -57,7 +57,9 @@ static int match_add_root_port(struct pci_dev *pdev, void *data)
 
 	/* TODO walk DVSEC to find component register base */
 	port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
+	cxl_device_lock(&port->dev);
 	rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE);
+	cxl_device_unlock(&port->dev);
 	if (rc) {
 		dev_err(dev, "failed to add dport: %s (%d)\n",
 			dev_name(&pdev->dev), rc);
@@ -78,7 +80,9 @@ static int mock_add_root_port(struct platform_device *pdev, void *data)
 	struct device *dev = ctx->dev;
 	int rc;
 
+	cxl_device_lock(&port->dev);
 	rc = cxl_add_dport(port, &pdev->dev, pdev->id, CXL_RESOURCE_NONE);
+	cxl_device_unlock(&port->dev);
 	if (rc) {
 		dev_err(dev, "failed to add dport: %s (%d)\n",
 			dev_name(&pdev->dev), rc);