[PATCH v6 03/10] cxl/pci: Fix NULL vs ERR_PTR confusion

[Dan Williams <dan.j.williams@intel.com>]

cxl_pci_map_regblock() may return an ERR_PTR(), but cxl_pci_setup_regs()
is only prepared for NULL as the error case. Pick the minimal fix for
-stable backport purposes and just have cxl_pci_map_regblock() return
NULL for errors.

Fixes: f8a7e8c29be8 ("cxl/pci: Reserve all device regions at once")
Cc: <stable@vger.kernel.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
Changes since v3:
- clarify in the changelog why cxl_pci_map_regblock() was changed to
  return NULL rather than fix the caller to expect an ERR_PTR().
  (Jonathan)

 drivers/cxl/pci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index ccc7c2573ddc..9c178002d49e 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -317,7 +317,7 @@ static void __iomem *cxl_pci_map_regblock(struct cxl_mem *cxlm,
 	if (pci_resource_len(pdev, bar) < offset) {
 		dev_err(dev, "BAR%d: %pr: too small (offset: %#llx)\n", bar,
 			&pdev->resource[bar], (unsigned long long)offset);
-		return IOMEM_ERR_PTR(-ENXIO);
+		return NULL;
 	}
 
 	addr = pci_iomap(pdev, bar, 0);