Re: [PATCH net-next 06/10] net: stmmac: Implement RSS and enable it in XGMAC core

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Mon,  5 Aug 2019 20:01:19 +0200, Jose Abreu wrote:
> Implement the RSS functionality and add the corresponding callbacks in
> XGMAC core.
> 
> Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> ---
> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: Jose Abreu <joabreu@synopsys.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: netdev@vger.kernel.org
> Cc: linux-stm32@st-md-mailman.stormreply.com
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org

> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
> index c4c45402b8f8..9ff9d9ac1a50 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
> @@ -254,6 +254,34 @@ static void dwxgmac2_clear(struct dma_desc *p)
>  	p->des3 = 0;
>  }
>  
> +static int dwxgmac2_get_rx_hash(struct dma_desc *p, u32 *hash,
> +				enum pkt_hash_types *type)
> +{
> +	unsigned int rdes3 = le32_to_cpu(p->des3);
> +	u32 ptype;
> +
> +	if (rdes3 & XGMAC_RDES3_RSV) {
> +		ptype = (rdes3 & XGMAC_RDES3_L34T) >> XGMAC_RDES3_L34T_SHIFT;
> +
> +		switch (ptype) {
> +		case 0x1:
> +		case 0x2:
> +		case 0x9:
> +		case 0xA:

nit: it'd be nice to have defines for these constants

> +			*type = PKT_HASH_TYPE_L4;
> +			break;
> +		default:
> +			*type = PKT_HASH_TYPE_L3;
> +			break;
> +		}
> +
> +		*hash = le32_to_cpu(p->des1);
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
>  const struct stmmac_desc_ops dwxgmac210_desc_ops = {
>  	.tx_status = dwxgmac2_get_tx_status,
>  	.rx_status = dwxgmac2_get_rx_status,

> @@ -4182,7 +4208,7 @@ int stmmac_dvr_probe(struct device *device,
>  	struct net_device *ndev = NULL;
>  	struct stmmac_priv *priv;
>  	u32 queue, maxq;
> -	int ret = 0;
> +	int i, ret = 0;
>  
>  	ndev = devm_alloc_etherdev_mqs(device, sizeof(struct stmmac_priv),
>  				       MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES);
> @@ -4290,6 +4316,14 @@ int stmmac_dvr_probe(struct device *device,
>  #endif
>  	priv->msg_enable = netif_msg_init(debug, default_msg_level);
>  
> +	/* Initialize RSS */
> +	netdev_rss_key_fill(priv->rss.key, sizeof(priv->rss.key));
> +	for (i = 0; i < ARRAY_SIZE(priv->rss.table); i++)
> +		priv->rss.table[i] = i % priv->plat->rx_queues_to_use;

ethtool_rxfh_indir_default() ?

> +	if (priv->dma_cap.rssen && priv->plat->rss_en)
> +		ndev->features |= NETIF_F_RXHASH;
> +
>  	/* MTU range: 46 - hw-specific max */
>  	ndev->min_mtu = ETH_ZLEN - ETH_HLEN;
>  	if ((priv->plat->enh_desc) || (priv->synopsys_id >= DWMAC_CORE_4_00))