ttm_mem_io_reserve
int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
EXPORT_SYMBOL(ttm_mem_io_reserve);
ret = ttm_mem_io_reserve(bo->bdev, mem);
ret = ttm_mem_io_reserve(bdev, mem);
ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);