diff --git a/drivers/vfio/iova_bitmap.c b/drivers/vfio/iova_bitmap.c
index 38b51613ecca..3f48125e2b9f 100644
--- a/drivers/vfio/iova_bitmap.c
+++ b/drivers/vfio/iova_bitmap.c
@@ -127,9 +127,8 @@ struct iova_bitmap {
 static unsigned long iova_bitmap_offset_to_index(struct iova_bitmap *bitmap,
 						 unsigned long iova)
 {
-	unsigned long pgsize = 1UL << bitmap->mapped.pgshift;
-
-	return iova / (BITS_PER_TYPE(*bitmap->bitmap) * pgsize);
+	return (iova >> bitmap->mapped.pgshift) /
+	       BITS_PER_TYPE(*bitmap->bitmap);
 }
 
 /*