mm/Kconfig: add MMU dependency for MIGRATION.

MIGRATION must depend on MMU, or allmodconfig for the nommu sh
architecture fails to build:

    CC      mm/migrate.o
  mm/migrate.c: In function 'remove_migration_pte':
  mm/migrate.c:134:3: error: implicit declaration of function 'pmd_trans_huge' [-Werror=implicit-function-declaration]
     if (pmd_trans_huge(*pmd))
     ^
  mm/migrate.c:149:2: error: implicit declaration of function 'is_swap_pte' [-Werror=implicit-function-declaration]
    if (!is_swap_pte(pte))
    ^
  ...

Also let CMA depend on MMU, or when NOMMU, if we select CMA, it will
select MIGRATION by force.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 6cdd27043303..026771a9b097 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -245,7 +245,7 @@ config COMPACTION
 config MIGRATION
         bool "Page migration"
         def_bool y
-        depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA
+        depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
         help
           Allows the migration of the physical location of pages of processes
           while the virtual addresses are not changed. This is useful in
@@ -480,7 +480,7 @@ config FRONTSWAP
 
 config CMA
         bool "Contiguous Memory Allocator"
-        depends on HAVE_MEMBLOCK
+        depends on HAVE_MEMBLOCK && MMU
         select MIGRATION
         select MEMORY_ISOLATION
         help