[PATCH 5.15 142/917] cxl/pci: Fix NULL vs ERR_PTR confusion

From: Dan Williams <redacted>

commit ca76a3a8052b71c0334d5c094859cfa340c290a8 upstream.

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: <redacted>
Reviewed-by: Ira Weiny <redacted>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163433325724.834522.17809774578178224149.stgit@dwillia2-desk3.amr.corp.intel.com (local)
Signed-off-by: Dan Williams <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/cxl/pci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c

@@ -972,7 +972,7 @@ static void __iomem *cxl_mem_map_regbloc
 	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);