diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ee1b5cb557c9..1ae8384637b5 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1076,7 +1076,7 @@ int iommu_tce_check_ioba(unsigned long page_shift,
 	if (ioba < offset)
 		return -EINVAL;
 
-	if ((ioba + 1) > (offset + size))
+	if ((ioba + npages < ioba) || (ioba - offset + npages > size))
 		return -EINVAL;
 
 	return 0;