cxl/pci: Cleanup repeated code in cxl_probe_regs() helpers

Rather then duplicating the setting of valid, length, and offset for
each type, just convey a pointer to the register map to common code.

Yes, the change in cxl_probe_component_regs() does not save
any lines of code, but it is preparation for adding another component
register type to map (RAS Capability Structure).
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166974409293.1608150.17661353937678581423.stgit@djiang5-desk3.ch.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/regs.c

@@ -59,36 +59,41 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
 
 	for (cap = 1; cap <= cap_count; cap++) {
 		void __iomem *register_block;
-		u32 hdr;
-		int decoder_cnt;
+		struct cxl_reg_map *rmap;
 		u16 cap_id, offset;
-		u32 length;
+		u32 length, hdr;
 
 		hdr = readl(base + cap * 0x4);
 
 		cap_id = FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, hdr);
 		offset = FIELD_GET(CXL_CM_CAP_PTR_MASK, hdr);
 		register_block = base + offset;
+		hdr = readl(register_block);
 
+		rmap = NULL;
 		switch (cap_id) {
-		case CXL_CM_CAP_CAP_ID_HDM:
+		case CXL_CM_CAP_CAP_ID_HDM: {
+			int decoder_cnt;
+
 			dev_dbg(dev, "found HDM decoder capability (0x%x)\n",
 				offset);
 
-			hdr = readl(register_block);
-
 			decoder_cnt = cxl_hdm_decoder_count(hdr);
 			length = 0x20 * decoder_cnt + 0x10;
-
-			map->hdm_decoder.valid = true;
-			map->hdm_decoder.offset = CXL_CM_OFFSET + offset;
-			map->hdm_decoder.size = length;
+			rmap = &map->hdm_decoder;
 			break;
+		}
 		default:
 			dev_dbg(dev, "Unknown CM cap ID: %d (0x%x)\n", cap_id,
 				offset);
 			break;
 		}
+
+		if (!rmap)
+			continue;
+		rmap->valid = true;
+		rmap->offset = CXL_CM_OFFSET + offset;
+		rmap->size = length;
 	}
 }
 EXPORT_SYMBOL_NS_GPL(cxl_probe_component_regs, CXL);
@@ -117,6 +122,7 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
 	cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array);
 
 	for (cap = 1; cap <= cap_count; cap++) {
+		struct cxl_reg_map *rmap;
 		u32 offset, length;
 		u16 cap_id;
 
@@ -125,28 +131,22 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
 		offset = readl(base + cap * 0x10 + 0x4);
 		length = readl(base + cap * 0x10 + 0x8);
 
+		rmap = NULL;
 		switch (cap_id) {
 		case CXLDEV_CAP_CAP_ID_DEVICE_STATUS:
 			dev_dbg(dev, "found Status capability (0x%x)\n", offset);
-
-			map->status.valid = true;
-			map->status.offset = offset;
-			map->status.size = length;
+			rmap = &map->status;
 			break;
 		case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX:
 			dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset);
-			map->mbox.valid = true;
-			map->mbox.offset = offset;
-			map->mbox.size = length;
+			rmap = &map->mbox;
 			break;
 		case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX:
 			dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset);
 			break;
 		case CXLDEV_CAP_CAP_ID_MEMDEV:
 			dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset);
-			map->memdev.valid = true;
-			map->memdev.offset = offset;
-			map->memdev.size = length;
+			rmap = &map->memdev;
 			break;
 		default:
 			if (cap_id >= 0x8000)
@@ -155,6 +155,12 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
 				dev_dbg(dev, "Unknown cap ID: %#x offset: %#x\n", cap_id, offset);
 			break;
 		}
+
+		if (!rmap)
+			continue;
+		rmap->valid = true;
+		rmap->offset = offset;
+		rmap->size = length;
 	}
 }
 EXPORT_SYMBOL_NS_GPL(cxl_probe_device_regs, CXL);