1 files changed, 46 insertions, 75 deletions

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 270d63d11e17..48f88d96029d 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -467,95 +467,64 @@ mbox_poll:
 	return 0;
 }
 
-static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
+/*
+ * Assume that any RCIEP that emits the CXL memory expander class code
+ * is an RCD
+ */
+static bool is_cxl_restricted(struct pci_dev *pdev)
 {
-	struct device *dev = &pdev->dev;
-
-	map->base = ioremap(map->resource, map->max_size);
-	if (!map->base) {
-		dev_err(dev, "failed to map registers\n");
-		return -ENOMEM;
-	}
-
-	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
-	return 0;
+	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
 }
 
-static void cxl_unmap_regblock(struct pci_dev *pdev,
-			       struct cxl_register_map *map)
+static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
+				  struct cxl_register_map *map)
 {
-	iounmap(map->base);
-	map->base = NULL;
-}
+	struct cxl_port *port;
+	struct cxl_dport *dport;
+	resource_size_t component_reg_phys;
 
-static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
-{
-	struct cxl_component_reg_map *comp_map;
-	struct cxl_device_reg_map *dev_map;
-	struct device *dev = &pdev->dev;
-	void __iomem *base = map->base;
-
-	switch (map->reg_type) {
-	case CXL_REGLOC_RBI_COMPONENT:
-		comp_map = &map->component_map;
-		cxl_probe_component_regs(dev, base, comp_map);
-		if (!comp_map->hdm_decoder.valid) {
-			dev_err(dev, "HDM decoder registers not found\n");
-			return -ENXIO;
-		}
+	*map = (struct cxl_register_map) {
+		.dev = &pdev->dev,
+		.resource = CXL_RESOURCE_NONE,
+	};
 
-		if (!comp_map->ras.valid)
-			dev_dbg(dev, "RAS registers not found\n");
-
-		dev_dbg(dev, "Set up component registers\n");
-		break;
-	case CXL_REGLOC_RBI_MEMDEV:
-		dev_map = &map->device_map;
-		cxl_probe_device_regs(dev, base, dev_map);
-		if (!dev_map->status.valid || !dev_map->mbox.valid ||
-		    !dev_map->memdev.valid) {
-			dev_err(dev, "registers not found: %s%s%s\n",
-				!dev_map->status.valid ? "status " : "",
-				!dev_map->mbox.valid ? "mbox " : "",
-				!dev_map->memdev.valid ? "memdev " : "");
-			return -ENXIO;
-		}
+	port = cxl_pci_find_port(pdev, &dport);
+	if (!port)
+		return -EPROBE_DEFER;
 
-		dev_dbg(dev, "Probing device registers...\n");
-		break;
-	default:
-		break;
-	}
+	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
+
+	put_device(&port->dev);
+
+	if (component_reg_phys == CXL_RESOURCE_NONE)
+		return -ENXIO;
+
+	map->resource = component_reg_phys;
+	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
+	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
 
 	return 0;
 }
 
-static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
-			  struct cxl_register_map *map)
+static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
+			      struct cxl_register_map *map)
 {
 	int rc;
 
 	rc = cxl_find_regblock(pdev, type, map);
-	if (rc)
-		return rc;
 
-	rc = cxl_map_regblock(pdev, map);
+	/*
+	 * If the Register Locator DVSEC does not exist, check if it
+	 * is an RCH and try to extract the Component Registers from
+	 * an RCRB.
+	 */
+	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
+		rc = cxl_rcrb_get_comp_regs(pdev, map);
+
 	if (rc)
 		return rc;
 
-	rc = cxl_probe_regs(pdev, map);
-	cxl_unmap_regblock(pdev, map);
-
-	return rc;
-}
-
-/*
- * Assume that any RCIEP that emits the CXL memory expander class code
- * is an RCD
- */
-static bool is_cxl_restricted(struct pci_dev *pdev)
-{
-	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
+	return cxl_setup_regs(map);
 }
 
 static int cxl_pci_ras_unmask(struct pci_dev *pdev)
@@ -854,11 +823,11 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		dev_warn(&pdev->dev,
 			 "Device DVSEC not present, skip CXL.mem init\n");
 
-	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
+	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
 	if (rc)
 		return rc;
 
-	rc = cxl_map_device_regs(&pdev->dev, &cxlds->regs.device_regs, &map);
+	rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs);
 	if (rc)
 		return rc;
 
@@ -867,14 +836,16 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	 * still be useful for management functions so don't return an error.
 	 */
 	cxlds->component_reg_phys = CXL_RESOURCE_NONE;
-	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
+	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
 	if (rc)
 		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
+	else if (!map.component_map.ras.valid)
+		dev_dbg(&pdev->dev, "RAS registers not found\n");
 
 	cxlds->component_reg_phys = map.resource;
 
-	rc = cxl_map_component_regs(&pdev->dev, &cxlds->regs.component,
-				    &map, BIT(CXL_CM_CAP_CAP_ID_RAS));
+	rc = cxl_map_component_regs(&map, &cxlds->regs.component,
+				    BIT(CXL_CM_CAP_CAP_ID_RAS));
 	if (rc)
 		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");