diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 954e334e01bbea5a5c028f445dd8551dd51dd718..9a353c2216d09a1c1a498da4344f31a03f90aad3 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -1305,7 +1305,7 @@ static int mv_xor_shared_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	msp->xor_base = devm_ioremap(&pdev->dev, res->start,
-				     res->end - res->start + 1);
+				     resource_size(res));
 	if (!msp->xor_base)
 		return -EBUSY;
 
@@ -1314,7 +1314,7 @@ static int mv_xor_shared_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	msp->xor_high_base = devm_ioremap(&pdev->dev, res->start,
-					  res->end - res->start + 1);
+					  resource_size(res));
 	if (!msp->xor_high_base)
 		return -EBUSY;