On 10/05/2023 10:50, Sarath Babu Naidu Gaddam wrote:
> Add dmaengine framework to communicate with the xilinx DMAengine
> driver(AXIDMA).
>
> Axi ethernet driver uses separate channels for transmit and receive.
> Add support for these channels to handle TX and RX with skb and
> appropriate callbacks. Also add axi ethernet core interrupt for
> +/**
> + * axienet_setup_dma_chan - request the dma channels.
> + * @ndev: Pointer to net_device structure
> + *
> + * Return: 0, on success.
> + * non-zero error value on failure
> + *
> + * This function requests the TX and RX channels. It also submits the
> + * allocated skb buffers and call back APIs to dmaengine.
> + *
> + */
> +static int axienet_setup_dma_chan(struct net_device *ndev)
> +{
> + struct axienet_local *lp = netdev_priv(ndev);
> + int i, ret;
> +
> + lp->tx_chan = dma_request_chan(lp->dev, "tx_chan0");
> + if (IS_ERR(lp->tx_chan)) {
> + ret = PTR_ERR(lp->tx_chan);
> + if (ret != -EPROBE_DEFER)
> + netdev_err(ndev, "No Ethernet DMA (TX) channel found\n");
dev_err_probe seems suitable here.
> + return ret;
> + }
> +
> + lp->rx_chan = dma_request_chan(lp->dev, "rx_chan0");
> + if (IS_ERR(lp->rx_chan)) {
> + ret = PTR_ERR(lp->rx_chan);
> + if (ret != -EPROBE_DEFER)
> + netdev_err(ndev, "No Ethernet DMA (RX) channel found\n");
dev_err_probe
> + goto err_dma_request_rx;
> + }
> + lp->skb_cache = kmem_cache_create("ethernet", sizeof(struct axi_skbuff),
> + 0, 0, NULL);
> + if (!lp->skb_cache) {
> + ret = -ENOMEM;
> + goto err_kmem;
> + }
> + /* TODO: Instead of BD_NUM_DEFAULT use runtime support*/
> + for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
> + axienet_rx_submit_desc(ndev);
> + dma_async_issue_pending(lp->rx_chan);
> +
> + return 0;
> +err_kmem:
> + dma_release_channel(lp->rx_chan);
> +err_dma_request_rx:
> + dma_release_channel(lp->tx_chan);
> + return ret;
> +}
> +
> +/**
> + * axienet_init_dmaengine - init the dmaengine code.
> + * @ndev: Pointer to net_device structure
> + *
> + * Return: 0, on success.
> + * non-zero error value on failure
> + *
> + * This is the dmaengine initialization code.
> + */
> +static inline int axienet_init_dmaengine(struct net_device *ndev)
> +{
> + int ret;
> +
> + ret = axienet_setup_dma_chan(ndev);
> +
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> /**
> * axienet_init_legacy_dma - init the dma legacy code.
> * @ndev: Pointer to net_device structure
> @@ -1239,7 +1520,20 @@ static int axienet_open(struct net_device *ndev)
>
> phylink_start(lp->phylink);
>
> - if (!AXIENET_USE_DMA(lp)) {
> + if (AXIENET_USE_DMA(lp)) {
> + ret = axienet_init_dmaengine(ndev);
> + if (ret < 0)
> + goto error_code;
> +
> + /* Enable interrupts for Axi Ethernet core (if defined) */
> + if (lp->eth_irq > 0) {
> + ret = request_irq(lp->eth_irq, axienet_eth_irq, IRQF_SHARED,
> + ndev->name, ndev);
> + if (ret)
> + goto error_code;
> + }
> +
> + } else {
> ret = axienet_init_legacy_dma(ndev);
> if (ret)
> goto error_code;
> @@ -1287,6 +1581,12 @@ static int axienet_stop(struct net_device *ndev)
> free_irq(lp->tx_irq, ndev);
> free_irq(lp->rx_irq, ndev);
> axienet_dma_bd_release(ndev);
> + } else {
> + dmaengine_terminate_all(lp->tx_chan);
> + dmaengine_terminate_all(lp->rx_chan);
> +
> + dma_release_channel(lp->rx_chan);
> + dma_release_channel(lp->tx_chan);
> }
>
> axienet_iow(lp, XAE_IE_OFFSET, 0);
> @@ -2136,6 +2436,33 @@ static int axienet_probe(struct platform_device *pdev)
> }
> netif_napi_add(ndev, &lp->napi_rx, axienet_rx_poll);
> netif_napi_add(ndev, &lp->napi_tx, axienet_tx_poll);
> + } else {
> + struct xilinx_vdma_config cfg;
> + struct dma_chan *tx_chan;
> +
> + lp->eth_irq = platform_get_irq_optional(pdev, 0);
> + tx_chan = dma_request_chan(lp->dev, "tx_chan0");
> +
> + if (IS_ERR(tx_chan)) {
> + ret = PTR_ERR(tx_chan);
> + if (ret != -EPROBE_DEFER)
> + dev_err(&pdev->dev, "No Ethernet DMA (TX) channel found\n");
dev_err_probe
Best regards,
Krzysztof
