Function xgetrf_buffer_size 

pub fn xgetrf_buffer_size(
    handle: &DnHandle,
    params: &Params,
    m: i64,
    n: i64,
    data_type_a: cudaDataType,
    a: *const c_void,
    lda: i64,
    compute_type: cudaDataType,
) -> Result<(usize, usize)>

Buffer-size query for generic LU factorization. Returns (workspace_bytes_on_device, workspace_bytes_on_host).