ttm_tt_set_placement_caching
r = ttm_tt_set_placement_caching(bo->ttm, tmp_mem.placement);
int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
r = ttm_tt_set_placement_caching(bo->ttm, tmp_mem.placement);
ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
EXPORT_SYMBOL(ttm_tt_set_placement_caching);