cxl: Explicitly initialize resources when media is not ready

When media is not ready do not assume that the capacity information from
the identify command is valid, i.e. ->total_bytes
->partition_align_bytes ->{volatile,persistent}_only_bytes. Explicitly
zero out the capacity resources and exit early.

Given zero-init of those fields this patch is functionally equivalent to
the prior state, but it improves readability and robustness going
forward.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168506118166.3004974.13523455340007852589.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Author: davejiang

drivers/cxl/core/mbox.c

@@ -1105,6 +1105,13 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
 	struct device *dev = cxlds->dev;
 	int rc;
 
+	if (!cxlds->media_ready) {
+		cxlds->dpa_res = DEFINE_RES_MEM(0, 0);
+		cxlds->ram_res = DEFINE_RES_MEM(0, 0);
+		cxlds->pmem_res = DEFINE_RES_MEM(0, 0);
+		return 0;
+	}
+
 	cxlds->dpa_res =
 		(struct resource)DEFINE_RES_MEM(0, cxlds->total_bytes);
 
@@ -1118,12 +1125,10 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
 				   cxlds->persistent_only_bytes, "pmem");
 	}
 
-	if (cxlds->media_ready) {
-		rc = cxl_mem_get_partition_info(cxlds);
-		if (rc) {
-			dev_err(dev, "Failed to query partition information\n");
-			return rc;
-		}
+	rc = cxl_mem_get_partition_info(cxlds);
+	if (rc) {
+		dev_err(dev, "Failed to query partition information\n");
+		return rc;
 	}
 
 	rc = add_dpa_res(dev, &cxlds->dpa_res, &cxlds->ram_res, 0,