cxl/pci: Refactor component register discovery for reuse

The endpoint implements component register setup code. Refactor it for
reuse with RCRB, downstream port, and upstream port setup.

Move PCI specifics from cxl_setup_regs() into cxl_pci_setup_regs().

Move cxl_setup_regs() into cxl/core/regs.c and export it. This also
includes supporting static functions cxl_map_registerblock(),
cxl_unmap_register_block() and cxl_probe_regs().

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230622205523.85375-8-terry.bowman@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 5 insertions, 74 deletions

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 0a89b96e6a8d..ac17bc0430dc 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -274,70 +274,8 @@ static int cxl_pci_setup_mailbox(struct cxl_dev_state *cxlds)
 	return 0;
 }
 
-static int cxl_map_regblock(struct cxl_register_map *map)
-{
-	struct device *dev = map->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;
-}
-
-static void cxl_unmap_regblock(struct cxl_register_map *map)
-{
-	iounmap(map->base);
-	map->base = NULL;
-}
-
-static int cxl_probe_regs(struct cxl_register_map *map)
-{
-	struct cxl_component_reg_map *comp_map;
-	struct cxl_device_reg_map *dev_map;
-	struct device *dev = map->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;
-		}
-
-		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;
-		}
-
-		dev_dbg(dev, "Probing device registers...\n");
-		break;
-	default:
-		break;
-	}
-
-	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;
 
@@ -345,14 +283,7 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
 	if (rc)
 		return rc;
 
-	rc = cxl_map_regblock(map);
-	if (rc)
-		return rc;
-
-	rc = cxl_probe_regs(map);
-	cxl_unmap_regblock(map);
-
-	return rc;
+	return cxl_setup_regs(map);
 }
 
 /*
@@ -683,7 +614,7 @@ 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;
 
@@ -696,7 +627,7 @@ 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);