[xdp-hints] Re: [PATCH bpf-next v2 7/8] mxl4: Support RX XDP metadata

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 11/21/2022 8:25 PM, Stanislav Fomichev wrote:
> RX timestamp and hash for now. Tested using the prog from the next
> patch.
> 
> Also enabling xdp metadata support; don't see why it's disabled,
> there is enough headroom..
> 
> Cc: Tariq Toukan <tariqt@nvidia.com>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Martin KaFai Lau <martin.lau@linux.dev>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Willem de Bruijn <willemb@google.com>
> Cc: Jesper Dangaard Brouer <brouer@redhat.com>
> Cc: Anatoly Burakov <anatoly.burakov@intel.com>
> Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
> Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
> Cc: Maryam Tahhan <mtahhan@redhat.com>
> Cc: xdp-hints@xdp-project.net
> Cc: netdev@vger.kernel.org
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
>   .../net/ethernet/mellanox/mlx4/en_netdev.c    | 10 ++++
>   drivers/net/ethernet/mellanox/mlx4/en_rx.c    | 48 ++++++++++++++++++-
>   include/linux/mlx4/device.h                   |  7 +++
>   3 files changed, 64 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> index 8800d3f1f55c..1cb63746a851 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> @@ -2855,6 +2855,11 @@ static const struct net_device_ops mlx4_netdev_ops = {
>   	.ndo_features_check	= mlx4_en_features_check,
>   	.ndo_set_tx_maxrate	= mlx4_en_set_tx_maxrate,
>   	.ndo_bpf		= mlx4_xdp,
> +
> +	.ndo_xdp_rx_timestamp_supported = mlx4_xdp_rx_timestamp_supported,
> +	.ndo_xdp_rx_timestamp	= mlx4_xdp_rx_timestamp,
> +	.ndo_xdp_rx_hash_supported = mlx4_xdp_rx_hash_supported,
> +	.ndo_xdp_rx_hash	= mlx4_xdp_rx_hash,
>   };
>   
>   static const struct net_device_ops mlx4_netdev_ops_master = {
> @@ -2887,6 +2892,11 @@ static const struct net_device_ops mlx4_netdev_ops_master = {
>   	.ndo_features_check	= mlx4_en_features_check,
>   	.ndo_set_tx_maxrate	= mlx4_en_set_tx_maxrate,
>   	.ndo_bpf		= mlx4_xdp,
> +
> +	.ndo_xdp_rx_timestamp_supported = mlx4_xdp_rx_timestamp_supported,
> +	.ndo_xdp_rx_timestamp	= mlx4_xdp_rx_timestamp,
> +	.ndo_xdp_rx_hash_supported = mlx4_xdp_rx_hash_supported,
> +	.ndo_xdp_rx_hash	= mlx4_xdp_rx_hash,
>   };
>   
>   struct mlx4_en_bond {
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> index 467356633172..fd14d59f6cbf 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> @@ -663,8 +663,50 @@ static int check_csum(struct mlx4_cqe *cqe, struct sk_buff *skb, void *va,
>   
>   struct mlx4_xdp_buff {
>   	struct xdp_buff xdp;
> +	struct mlx4_cqe *cqe;
> +	struct mlx4_en_dev *mdev;
> +	struct mlx4_en_rx_ring *ring;
> +	struct net_device *dev;
>   };
>   
> +bool mlx4_xdp_rx_timestamp_supported(const struct xdp_md *ctx)
> +{
> +	struct mlx4_xdp_buff *_ctx = (void *)ctx;
> +
> +	return _ctx->ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL;
> +}
> +
> +u64 mlx4_xdp_rx_timestamp(const struct xdp_md *ctx)
> +{
> +	struct mlx4_xdp_buff *_ctx = (void *)ctx;
> +	unsigned int seq;
> +	u64 timestamp;
> +	u64 nsec;
> +
> +	timestamp = mlx4_en_get_cqe_ts(_ctx->cqe);
> +
> +	do {
> +		seq = read_seqbegin(&_ctx->mdev->clock_lock);
> +		nsec = timecounter_cyc2time(&_ctx->mdev->clock, timestamp);
> +	} while (read_seqretry(&_ctx->mdev->clock_lock, seq));
> +

This is open-code version of mlx4_en_fill_hwtstamps.
Better use the existing function.

> +	return ns_to_ktime(nsec);
> +}
> +
> +bool mlx4_xdp_rx_hash_supported(const struct xdp_md *ctx)
> +{
> +	struct mlx4_xdp_buff *_ctx = (void *)ctx;
> +
> +	return _ctx->dev->features & NETIF_F_RXHASH;
> +}
> +
> +u32 mlx4_xdp_rx_hash(const struct xdp_md *ctx)
> +{
> +	struct mlx4_xdp_buff *_ctx = (void *)ctx;
> +
> +	return be32_to_cpu(_ctx->cqe->immed_rss_invalid);
> +}
> +
>   int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int budget)
>   {
>   	struct mlx4_en_priv *priv = netdev_priv(dev);
> @@ -781,8 +823,12 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
>   						DMA_FROM_DEVICE);
>   
>   			xdp_prepare_buff(&mxbuf.xdp, va - frags[0].page_offset,
> -					 frags[0].page_offset, length, false);
> +					 frags[0].page_offset, length, true);
>   			orig_data = mxbuf.xdp.data;
> +			mxbuf.cqe = cqe;
> +			mxbuf.mdev = priv->mdev;
> +			mxbuf.ring = ring;
> +			mxbuf.dev = dev;
>   
>   			act = bpf_prog_run_xdp(xdp_prog, &mxbuf.xdp);
>   
> diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
> index 6646634a0b9d..d5904da1d490 100644
> --- a/include/linux/mlx4/device.h
> +++ b/include/linux/mlx4/device.h
> @@ -1585,4 +1585,11 @@ static inline int mlx4_get_num_reserved_uar(struct mlx4_dev *dev)
>   	/* The first 128 UARs are used for EQ doorbells */
>   	return (128 >> (PAGE_SHIFT - dev->uar_page_shift));
>   }
> +
> +struct xdp_md;
> +bool mlx4_xdp_rx_timestamp_supported(const struct xdp_md *ctx);
> +u64 mlx4_xdp_rx_timestamp(const struct xdp_md *ctx);
> +bool mlx4_xdp_rx_hash_supported(const struct xdp_md *ctx);
> +u32 mlx4_xdp_rx_hash(const struct xdp_md *ctx);
> +
>   #endif /* MLX4_DEVICE_H */