[PATCH v4 03/23] cxl: Add support for reading CXL switch CDAT table

[Dave Jiang <dave.jiang@xxxxxxxxx>]

Move read_cdat_data() from endpoint probe to general port probe to
allow reading of CDAT data for CXL switches as well as CXL device.
Add wrapper support for cxl_test to bypass the cdat reading.

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>

---
v4:
- Remove cxl_test wrapper. (Ira)
---
 drivers/cxl/core/pci.c |   20 +++++++++++++++-----
 drivers/cxl/port.c     |    6 +++---
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9c7e2f69d9ca..1c415b26e866 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -546,16 +546,26 @@ static unsigned char cdat_checksum(void *buf, size_t size)
  */
 void read_cdat_data(struct cxl_port *port)
 {
-	struct pci_doe_mb *cdat_doe;
-	struct device *dev = &port->dev;
 	struct device *uport = port->uport;
-	struct cxl_memdev *cxlmd = to_cxl_memdev(uport);
-	struct cxl_dev_state *cxlds = cxlmd->cxlds;
-	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	struct device *dev = &port->dev;
+	struct cxl_dev_state *cxlds;
+	struct pci_doe_mb *cdat_doe;
+	struct cxl_memdev *cxlmd;
+	struct pci_dev *pdev;
 	size_t cdat_length;
 	void *cdat_table;
 	int rc;
 
+	if (is_cxl_memdev(uport)) {
+		cxlmd = to_cxl_memdev(uport);
+		cxlds = cxlmd->cxlds;
+		pdev = to_pci_dev(cxlds->dev);
+	} else if (dev_is_pci(uport)) {
+		pdev = to_pci_dev(uport);
+	} else {
+		return;
+	}
+
 	cdat_doe = pci_find_doe_mailbox(pdev, PCI_DVSEC_VENDOR_ID_CXL,
 					CXL_DOE_PROTOCOL_TABLE_ACCESS);
 	if (!cdat_doe) {
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 22a7ab2bae7c..615e0ef6b440 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -93,9 +93,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
 	if (IS_ERR(cxlhdm))
 		return PTR_ERR(cxlhdm);
 
-	/* Cache the data early to ensure is_visible() works */
-	read_cdat_data(port);
-
 	get_device(&cxlmd->dev);
 	rc = devm_add_action_or_reset(&port->dev, schedule_detach, cxlmd);
 	if (rc)
@@ -135,6 +132,9 @@ static int cxl_port_probe(struct device *dev)
 {
 	struct cxl_port *port = to_cxl_port(dev);
 
+	/* Cache the data early to ensure is_visible() works */
+	read_cdat_data(port);
+
 	if (is_cxl_endpoint(port))
 		return cxl_endpoint_port_probe(port);
 	return cxl_switch_port_probe(port);