diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 5c8ba5484d86..a96ce7ec1ca5 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -510,17 +510,17 @@ static int null_lnvm_id(struct request_queue *q, struct nvm_id *id)
 	id->ppaf.ch_offset = 56;
 	id->ppaf.ch_len = 8;
 
-	do_div(size, bs); /* convert size to pages */
-	do_div(size, 256); /* concert size to pgs pr blk */
+	sector_div(size, bs); /* convert size to pages */
+	size >>= 8; /* concert size to pgs pr blk */
 	grp = &id->groups[0];
 	grp->mtype = 0;
 	grp->fmtype = 0;
 	grp->num_ch = 1;
 	grp->num_pg = 256;
 	blksize = size;
-	do_div(size, (1 << 16));
+	size >>= 16;
 	grp->num_lun = size + 1;
-	do_div(blksize, grp->num_lun);
+	sector_div(blksize, grp->num_lun);
 	grp->num_blk = blksize;
 	grp->num_pln = 1;