On Thu, Sep 3, 2020 at 11:01 PM Saeed Mahameed <sae...@nvidia.com> wrote:
>
> From: Maxim Mikityanskiy <maxi...@mellanox.com>
>
> A constant for the number of DS in an empty WQE (i.e. a WQE without data
> segments) is needed in multiple places (normal TX data path, MPWQE in
> XDP), but currently we have a constant for XDP and an inline formula in
> normal TX. This patch introduces a common constant.
>
> Additionally, mlx5e_xdp_mpwqe_session_start is converted to use struct
> assignment, because the code nearby is touched.
>
> Signed-off-by: Maxim Mikityanskiy <maxi...@mellanox.com>
> Signed-off-by: Saeed Mahameed <sae...@nvidia.com>
> ---
> .../net/ethernet/mellanox/mlx5/core/en/txrx.h | 2 ++
> .../net/ethernet/mellanox/mlx5/core/en/xdp.c | 13 +++++++-----
> .../net/ethernet/mellanox/mlx5/core/en/xdp.h | 21 +++++++------------
> .../net/ethernet/mellanox/mlx5/core/en_tx.c | 2 +-
> 4 files changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
> b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
> index d4ee22789ab0..155b89998891 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
> @@ -7,6 +7,8 @@
> #include "en.h"
> #include <linux/indirect_call_wrapper.h>
>
> +#define MLX5E_TX_WQE_EMPTY_DS_COUNT (sizeof(struct mlx5e_tx_wqe) /
> MLX5_SEND_WQE_DS)
> +
Out of curiosity, what is the logic for dividing this struct by 16?
struct mlx5e_tx_wqe {
struct mlx5_wqe_ctrl_seg ctrl;
struct mlx5_wqe_eth_seg eth;
struct mlx5_wqe_data_seg data[0];
};
> #define INL_HDR_START_SZ (sizeof(((struct mlx5_wqe_eth_seg
> *)NULL)->inline_hdr.start))
>
> enum mlx5e_icosq_wqe_type {
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> index 7fccd2ea7dc9..81cd9a04bcb0 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> @@ -196,16 +196,19 @@ static void mlx5e_xdp_mpwqe_session_start(struct
> mlx5e_xdpsq *sq)
> {
> struct mlx5e_xdp_mpwqe *session = &sq->mpwqe;
> struct mlx5e_xdpsq_stats *stats = sq->stats;
> + struct mlx5e_tx_wqe *wqe;
> u16 pi;
>
> pi = mlx5e_xdpsq_get_next_pi(sq, MLX5E_XDP_MPW_MAX_WQEBBS);
> - session->wqe = MLX5E_TX_FETCH_WQE(sq, pi);
> -
> + wqe = MLX5E_TX_FETCH_WQE(sq, pi);
> net_prefetchw(session->wqe->data);
Is this prefetch still valid? And is the temporary variable wqe still
needed at all?
> - session->ds_count = MLX5E_XDP_TX_EMPTY_DS_COUNT;
> - session->pkt_count = 0;
>
> - mlx5e_xdp_update_inline_state(sq);
> + *session = (struct mlx5e_xdp_mpwqe) {
> + .wqe = wqe,
> + .ds_count = MLX5E_TX_WQE_EMPTY_DS_COUNT,
> + .pkt_count = 0,
> + .inline_on = mlx5e_xdp_get_inline_state(sq,
> session->inline_on),
> + };
>
> stats->mpwqe++;
> }
