[RFC PATCH 05/13] cxl: fix check about pmem resource

[<alucerop@amd.com>]

From: Alejandro Lucero <alucerop@amd.com>

Current check is using resource_size which counts on a range bigger than
0. For a resource with start and end being 0, resource_size returns 1
and implying a false positive. Use the end not being zero as the new check.

Note: If I´m not missing anything here, this should be extended to the
whole linux kernel where resource_size is being used in conditionals,
and where the likely right fix is to modify resource_size itself
checking for the range not being 0.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
---
 drivers/cxl/core/hdm.c    | 4 ++--
 drivers/cxl/core/memdev.c | 8 ++++----
 drivers/cxl/mem.c         | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 47d9faf5897f..c5f70741d70a 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -432,12 +432,12 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
 	 * Only allow modes that are supported by the current partition
 	 * configuration
 	 */
-	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
+	if (mode == CXL_DECODER_PMEM && !cxlds->pmem_res.end) {
 		dev_dbg(dev, "no available pmem capacity\n");
 		rc = -ENXIO;
 		goto out;
 	}
-	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
+	if (mode == CXL_DECODER_RAM && !cxlds->ram_res.end) {
 		dev_dbg(dev, "no available ram capacity\n");
 		rc = -ENXIO;
 		goto out;
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 0336b3f14f4a..b61d57d0d4f4 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -197,14 +197,14 @@ static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd)
 	int rc = 0;
 
 	/* CXL 3.0 Spec 8.2.9.8.4.1 Separate pmem and ram poison requests */
-	if (resource_size(&cxlds->pmem_res)) {
+	if (cxlds->pmem_res.end) {
 		offset = cxlds->pmem_res.start;
 		length = resource_size(&cxlds->pmem_res);
 		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
 		if (rc)
 			return rc;
 	}
-	if (resource_size(&cxlds->ram_res)) {
+	if (cxlds->ram_res.end) {
 		offset = cxlds->ram_res.start;
 		length = resource_size(&cxlds->ram_res);
 		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
@@ -266,7 +266,7 @@ static int __cxl_dpa_to_region(struct device *dev, void *arg)
 		return 0;
 
 	cxled = to_cxl_endpoint_decoder(dev);
-	if (!cxled->dpa_res || !resource_size(cxled->dpa_res))
+	if (!cxled->dpa_res || !cxled->dpa_res->end)
 		return 0;
 
 	if (dpa > cxled->dpa_res->end || dpa < cxled->dpa_res->start)
@@ -302,7 +302,7 @@ static int cxl_validate_poison_dpa(struct cxl_memdev *cxlmd, u64 dpa)
 	if (!IS_ENABLED(CONFIG_DEBUG_FS))
 		return 0;
 
-	if (!resource_size(&cxlds->dpa_res)) {
+	if (!cxlds->dpa_res.end) {
 		dev_dbg(cxlds->dev, "device has no dpa resource\n");
 		return -EINVAL;
 	}
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 6dc2bf1e2b1a..a168343d2d4d 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -174,7 +174,7 @@ static int cxl_mem_probe(struct device *dev)
 	if (rc)
 		return rc;
 
-	if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM)) {
+	if (cxlds->pmem_res.end && IS_ENABLED(CONFIG_CXL_PMEM)) {
 		rc = devm_cxl_add_nvdimm(cxlmd);
 		if (rc == -ENODEV)
 			dev_info(dev, "PMEM disabled by platform\n");
-- 
2.17.1