PCI: of: Warn if non-prefetchable memory aperture size is > 32-bit

As per PCIe spec r5.0, sec 7.5.1.3.8 only 32-bit BAR registers are defined
for non-prefetchable memory and hence a warning should be reported when
the size of them go beyond 32-bits.

Link: https://lore.kernel.org/r/20201118144626.32189-2-vidyas@nvidia.com
Tested-by: Thierry Reding <treding@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

drivers/pci/of.c

@@ -556,6 +556,11 @@ static int pci_parse_request_of_pci_ranges(struct device *dev,
 			break;
 		case IORESOURCE_MEM:
 			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+
+			if (!(res->flags & IORESOURCE_PREFETCH))
+				if (upper_32_bits(resource_size(res)))
+					dev_warn(dev, "Memory resource size exceeds max for 32 bits\n");
+
 			break;
 		}
 	}