devmap_managed_enable   20 mm/memremap.c  static atomic_t devmap_managed_enable;
devmap_managed_enable   24 mm/memremap.c  	if (atomic_dec_and_test(&devmap_managed_enable))
devmap_managed_enable   35 mm/memremap.c  	if (atomic_inc_return(&devmap_managed_enable) == 1)