diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 2d7bb8c..e489752 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -83,11 +83,10 @@
 		return 0;
 	}
 
-	if ((tbl->it_offset + tbl->it_size) > (mask >> IOMMU_PAGE_SHIFT)) {
-		dev_info(dev, "Warning: IOMMU window too big for device mask\n");
-		dev_info(dev, "mask: 0x%08llx, table end: 0x%08lx\n",
-				mask, (tbl->it_offset + tbl->it_size) <<
-				IOMMU_PAGE_SHIFT);
+	if (tbl->it_offset > (mask >> IOMMU_PAGE_SHIFT)) {
+		dev_info(dev, "Warning: IOMMU offset too big for device mask\n");
+		dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n",
+				mask, tbl->it_offset << IOMMU_PAGE_SHIFT);
 		return 0;
 	} else
 		return 1;