On kernels without CONFIG_MMU, we get a link error for the siw driver: drivers/infiniband/sw/siw/siw_mem.o: In function `siw_umem_get': siw_mem.c:(.text+0x4c8): undefined reference to `can_do_mlock' I don't know whether this driver is able to work at all without an MMU, but it's easy to avoid the link problem by adding another compile-time check. Fixes: 2251334dcac9 ("rdma/siw: application buffer management") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/infiniband/sw/siw/siw_mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index e99983f07663..b3b614c07fdb 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -374,7 +374,7 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) unsigned int foll_flags = FOLL_WRITE; int num_pages, num_chunks, i, rv = 0; - if (!can_do_mlock()) + if (!IS_ENABLED(CONFIG_MMU) || !can_do_mlock()) return ERR_PTR(-EPERM); if (!len) -- 2.20.0