MLX5_BF_OFFSET
mlx5_write64(wqe, conn->fdev->conn_res.uar->map + MLX5_BF_OFFSET);
mlx5_write64(ctrl, dr_qp->uar->map + MLX5_BF_OFFSET);
(1 << MLX5_CAP_GEN(mdev, log_bf_reg_size)) + MLX5_BF_OFFSET;
bfreg_idx = (((uintptr_t)bfreg->map % MLX5_ADAPTER_PAGE_SIZE) - MLX5_BF_OFFSET) / bf_reg_size;