On 14/04/2024 14:59, Niklas Söderlund wrote:
> Add initial support for Renesas Ethernet-TSN End-station device of R-Car
> V4H. The Ethernet End-station can connect to an Ethernet network using a
> 10 Mbps, 100 Mbps, or 1 Gbps full-duplex link via MII/GMII/RMII/RGMII.
> Depending on the connected PHY.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
> * Changes since RFC
> - Fix issues in MDIO communication.
> - Use a dedicated OF node for the MDIO bus.
> ---
> MAINTAINERS | 8 +
> drivers/net/ethernet/renesas/Kconfig | 11 +
> drivers/net/ethernet/renesas/Makefile | 2 +
> drivers/net/ethernet/renesas/rtsn.c | 1421 +++++++++++++++++++++++++
> drivers/net/ethernet/renesas/rtsn.h | 464 ++++++++
> 5 files changed, 1906 insertions(+)
> create mode 100644 drivers/net/ethernet/renesas/rtsn.c
> create mode 100644 drivers/net/ethernet/renesas/rtsn.h
<snip>
> diff --git a/drivers/net/ethernet/renesas/rtsn.c b/drivers/net/ethernet/renesas/rtsn.c
> new file mode 100644
> index 000000000000..291ab421d68f
> --- /dev/null
> +++ b/drivers/net/ethernet/renesas/rtsn.c
<snip>
> +static bool rtsn_rx(struct net_device *ndev, int *quota)
> +{
> + struct rtsn_ext_ts_desc *desc;
> + struct rtsn_private *priv;
> + struct sk_buff *skb;
> + dma_addr_t dma_addr;
> + int boguscnt;
I find the variable name `boguscnt` very unclear, I'm not sure if it
means the count is bogus, or it is counting bogus items?
I don't think you need to match what I've done in ravb_main.c exactly,
but I'd prefer to see a better variable name here.
> + u16 pkt_len;
> + u32 get_ts;
> + int entry;
> + int limit;
> +
> + priv = netdev_priv(ndev);
> +
> + entry = priv->cur_rx % priv->num_rx_ring;
> + desc = &priv->rx_ring[entry];
> +
> + boguscnt = priv->dirty_rx + priv->num_rx_ring - priv->cur_rx;
> + boguscnt = min(boguscnt, *quota);
> + limit = boguscnt;
> +
> + while ((desc->die_dt & DT_MASK) != DT_FEMPTY) {
> + dma_rmb();
> + pkt_len = le16_to_cpu(desc->info_ds) & RX_DS;
> + if (--boguscnt < 0)
> + break;
> +
> + skb = priv->rx_skb[entry];
> + priv->rx_skb[entry] = NULL;
> + dma_addr = le32_to_cpu(desc->dptr);
> + dma_unmap_single(ndev->dev.parent, dma_addr, PKT_BUF_SZ,
> + DMA_FROM_DEVICE);
> +
> + get_ts = priv->ptp_priv->tstamp_rx_ctrl &
> + RCAR_GEN4_RXTSTAMP_TYPE_V2_L2_EVENT;
> + if (get_ts) {
> + struct skb_shared_hwtstamps *shhwtstamps;
> + struct timespec64 ts;
> +
> + shhwtstamps = skb_hwtstamps(skb);
> + memset(shhwtstamps, 0, sizeof(*shhwtstamps));
> +
> + ts.tv_sec = (u64)le32_to_cpu(desc->ts_sec);
> + ts.tv_nsec = le32_to_cpu(desc->ts_nsec & cpu_to_le32(0x3fffffff));
> +
> + shhwtstamps->hwtstamp = timespec64_to_ktime(ts);
> + }
> +
> + skb_put(skb, pkt_len);
> + skb->protocol = eth_type_trans(skb, ndev);
> + netif_receive_skb(skb);
> + ndev->stats.rx_packets++;
> + ndev->stats.rx_bytes += pkt_len;
> +
> + entry = (++priv->cur_rx) % priv->num_rx_ring;
> + desc = &priv->rx_ring[entry];
> + }
> +
> + /* Refill the RX ring buffers */
> + for (; priv->cur_rx - priv->dirty_rx > 0; priv->dirty_rx++) {
> + entry = priv->dirty_rx % priv->num_rx_ring;
> + desc = &priv->rx_ring[entry];
> + desc->info_ds = cpu_to_le16(PKT_BUF_SZ);
> +
> + if (!priv->rx_skb[entry]) {
> + skb = netdev_alloc_skb(ndev,
> + PKT_BUF_SZ + RTSN_ALIGN - 1);
I'll send my work using a page pool today as an RFC so you can see if it
would be beneficial to use that here as well. I was going to hold off
until the bugfix patches have merged so that I don't need to go through
another RFC round, but it will be good to get some more review on the
series anyway.
> + if (!skb)
> + break;
> + skb_reserve(skb, NET_IP_ALIGN);
> + dma_addr = dma_map_single(ndev->dev.parent, skb->data,
> + le16_to_cpu(desc->info_ds),
> + DMA_FROM_DEVICE);
> + if (dma_mapping_error(ndev->dev.parent, dma_addr))
> + desc->info_ds = cpu_to_le16(0);
> + desc->dptr = cpu_to_le32(dma_addr);
> + skb_checksum_none_assert(skb);
> + priv->rx_skb[entry] = skb;
> + }
> + dma_wmb();
> + desc->die_dt = DT_FEMPTY | D_DIE;
> + }
> +
> + desc = &priv->rx_ring[priv->num_rx_ring];
> + desc->die_dt = DT_LINK;
> +
> + *quota -= limit - (++boguscnt);
> +
> + return boguscnt <= 0;
> +}
> +
> +static int rtsn_poll(struct napi_struct *napi, int budget)
> +{
> + struct rtsn_private *priv;
> + struct net_device *ndev;
> + unsigned long flags;
> + int quota = budget;
> +
> + ndev = napi->dev;
> + priv = netdev_priv(ndev);
> +
> + /* Processing RX Descriptor Ring */
> + if (rtsn_rx(ndev, "a))
> + goto out;
> +
> + /* Processing TX Descriptor Ring */
> + spin_lock_irqsave(&priv->lock, flags);
> + rtsn_tx_free(ndev, true);
> + netif_wake_subqueue(ndev, 0);
> + spin_unlock_irqrestore(&priv->lock, flags);
> +
> + napi_complete(napi);
We should use napi_complete_done() here as described in
Documentation/networking/napi.rst. That will require rtsn_rx() to return
the number of packets received so that it can be passed as the work_done
argument to napi_complete_done().
> +
> + /* Re-enable TX/RX interrupts */
> + spin_lock_irqsave(&priv->lock, flags);
> + rtsn_ctrl_data_irq(priv, true);
> + __iowmb();
> + spin_unlock_irqrestore(&priv->lock, flags);
> +out:
> + return budget - quota;
> +}
<snip>
> +static int rtsn_probe(struct platform_device *pdev)
> +{
> + struct rtsn_private *priv;
> + struct net_device *ndev;
> + struct resource *res;
> + int ret;
> +
> + ndev = alloc_etherdev_mqs(sizeof(struct rtsn_private), TX_NUM_CHAINS,
> + RX_NUM_CHAINS);
> + if (!ndev)
> + return -ENOMEM;
> +
> + priv = netdev_priv(ndev);
> + priv->pdev = pdev;
> + priv->ndev = ndev;
> + priv->ptp_priv = rcar_gen4_ptp_alloc(pdev);
> +
> + spin_lock_init(&priv->lock);
> + platform_set_drvdata(pdev, priv);
> +
> + priv->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(priv->clk)) {
> + ret = -PTR_ERR(priv->clk);
> + goto error_alloc;
> + }
> +
> + priv->reset = devm_reset_control_get(&pdev->dev, NULL);
> + if (IS_ERR(priv->reset)) {
> + ret = -PTR_ERR(priv->reset);
> + goto error_alloc;
> + }
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "tsnes");
> + if (!res) {
> + dev_err(&pdev->dev, "Can't find tsnes resource\n");
> + ret = -EINVAL;
> + goto error_alloc;
> + }
> +
> + priv->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->base)) {
> + ret = PTR_ERR(priv->base);
> + goto error_alloc;
> + }
> +
> + SET_NETDEV_DEV(ndev, &pdev->dev);
> + ether_setup(ndev);
> +
> + ndev->features = NETIF_F_RXCSUM;
> + ndev->hw_features = NETIF_F_RXCSUM;
A quick skim of the datasheet suggests that TX checksum calculation is
also supported. It's probably worth listing which hardware features this
driver supports/does not support in the commit message.
Thanks,
--
Paul BarkerAttachment:
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