Re: [PATCH rdma-next 6/7] IB/mlx5: Assign DSCP for R-RoCE QPs Address Path

[Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

On Wed, Jan 18, 2017 at 02:10:35PM +0200, Leon Romanovsky wrote:
> From: Majd Dibbiny <majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> 
> For Routable RoCE QPs, the DSCP should be set in the QP's
> address path.
> 
> The DSCP's value is derived from the traffic class.
> 
> Fixes: 2811ba51b049 ("IB/mlx5: Add RoCE fields to Address Vector")
> Cc: Achiad Shochat <achiad-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Majd Dibbiny <majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Reviewed-by: Moni Shoua <monis-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> ---
>  drivers/infiniband/hw/mlx5/main.c    | 21 +++++++++++++++++++++
>  drivers/infiniband/hw/mlx5/mlx5_ib.h |  2 ++
>  drivers/infiniband/hw/mlx5/qp.c      |  7 +++++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index 1dea407..6a81f027 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -325,6 +325,27 @@ __be16 mlx5_get_roce_udp_sport(struct mlx5_ib_dev *dev, u8 port_num,
>  	return cpu_to_be16(MLX5_CAP_ROCE(dev->mdev, r_roce_min_src_udp_port));
>  }
>  
> +int mlx5_get_roce_gid_type(struct mlx5_ib_dev *dev, u8 port_num,
> +			   int index, enum ib_gid_type *gid_type)
> +{
> +	struct ib_gid_attr attr;
> +	union ib_gid gid;
> +	int ret;
> +
> +	ret = ib_get_cached_gid(&dev->ib_dev, port_num, index, &gid, &attr);
> +	if (ret)
> +		return ret;
> +
> +	if (!attr.ndev)
> +		return -ENODEV;

Two questions:
First for my understanding :) I see that this check is already done in
__ib_cache_gid_get so why it is not enough?
Second: Since this is light test, can we have it before the call to
ib_get_cached_gid?

> +
> +	dev_put(attr.ndev);
> +
> +	*gid_type = attr.gid_type;
> +
> +	return 0;
> +}
> +
>  static int mlx5_use_mad_ifc(struct mlx5_ib_dev *dev)
>  {
>  	if (MLX5_CAP_GEN(dev->mdev, port_type) == MLX5_CAP_PORT_TYPE_IB)
> diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> index e1a4b93d..dda01d7 100644
> --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
> +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> @@ -872,6 +872,8 @@ int mlx5_ib_set_vf_guid(struct ib_device *device, int vf, u8 port,
>  
>  __be16 mlx5_get_roce_udp_sport(struct mlx5_ib_dev *dev, u8 port_num,
>  			       int index);
> +int mlx5_get_roce_gid_type(struct mlx5_ib_dev *dev, u8 port_num,
> +			   int index, enum ib_gid_type *gid_type);
>  
>  /* GSI QP helper functions */
>  struct ib_qp *mlx5_ib_gsi_create_qp(struct ib_pd *pd,
> diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
> index 9af9b95..e22d957 100644
> --- a/drivers/infiniband/hw/mlx5/qp.c
> +++ b/drivers/infiniband/hw/mlx5/qp.c
> @@ -2198,6 +2198,7 @@ static int mlx5_set_path(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
>  {
>  	enum rdma_link_layer ll = rdma_port_get_link_layer(&dev->ib_dev, port);
>  	int err;
> +	enum ib_gid_type gid_type;
>  
>  	if (attr_mask & IB_QP_PKEY_INDEX)
>  		path->pkey_index = cpu_to_be16(alt ? attr->alt_pkey_index :
> @@ -2216,10 +2217,16 @@ static int mlx5_set_path(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
>  	if (ll == IB_LINK_LAYER_ETHERNET) {
>  		if (!(ah->ah_flags & IB_AH_GRH))
>  			return -EINVAL;
> +		err = mlx5_get_roce_gid_type(dev, port, ah->grh.sgid_index,
> +					     &gid_type);
> +		if (err)
> +			return err;
>  		memcpy(path->rmac, ah->dmac, sizeof(ah->dmac));
>  		path->udp_sport = mlx5_get_roce_udp_sport(dev, port,
>  							  ah->grh.sgid_index);
>  		path->dci_cfi_prio_sl = (ah->sl & 0x7) << 4;
> +		if (gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP)
> +			path->ecn_dscp = (ah->grh.traffic_class >> 2) & 0x3f;
>  	} else {
>  		path->fl_free_ar = (path_flags & MLX5_PATH_FLAG_FL) ? 0x80 : 0;
>  		path->fl_free_ar |=
> -- 
> 2.10.2
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html