PCI: rcar: Verify that mem_res is 64K-aligned

The lower 16 bits of the address, which is managed by mem_res, need to be
zero.  Check the address to verify this.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
index dd6b84e..367e28f 100644
--- a/drivers/pci/host/pci-rcar-gen2.c
+++ b/drivers/pci/host/pci-rcar-gen2.c
@@ -301,6 +301,9 @@
 	if (!mem_res || !mem_res->start)
 		return -ENODEV;
 
+	if (mem_res->start & 0xFFFF)
+		return -EINVAL;
+
 	priv = devm_kzalloc(&pdev->dev,
 			    sizeof(struct rcar_pci_priv), GFP_KERNEL);
 	if (!priv)