2022-04-25 19:05:33

by Stephen Hemminger

[permalink] [raw]
Subject: Re: [PATCH net-next v9 2/2] net: ethernet: Add driver for Sunplus SP7021

On Mon, 25 Apr 2022 18:30:40 +0800
Wells Lu <[email protected]> wrote:

> +
> +int spl2sw_rx_poll(struct napi_struct *napi, int budget)
> +{
> + struct spl2sw_common *comm = container_of(napi, struct spl2sw_common, rx_napi);
> + struct spl2sw_mac_desc *desc, *h_desc;
> + struct net_device_stats *stats;
> + struct sk_buff *skb, *new_skb;
> + struct spl2sw_skb_info *sinfo;
> + int budget_left = budget;
> + u32 rx_pos, pkg_len;
> + u32 num, rx_count;
> + s32 queue;
> + u32 mask;
> + int port;
> + u32 cmd;
> +
> + /* Process high-priority queue and then low-priority queue. */
> + for (queue = 0; queue < RX_DESC_QUEUE_NUM; queue++) {
> + rx_pos = comm->rx_pos[queue];
> + rx_count = comm->rx_desc_num[queue];
> +
> + for (num = 0; num < rx_count && budget_left; num++) {
> + sinfo = comm->rx_skb_info[queue] + rx_pos;
> + desc = comm->rx_desc[queue] + rx_pos;
> + cmd = desc->cmd1;
> +
> + if (cmd & RXD_OWN)
> + break;
> +
> + port = FIELD_GET(RXD_PKT_SP, cmd);
> + if (port < MAX_NETDEV_NUM && comm->ndev[port])
> + stats = &comm->ndev[port]->stats;
> + else
> + goto spl2sw_rx_poll_rec_err;
> +
> + pkg_len = FIELD_GET(RXD_PKT_LEN, cmd);
> + if (unlikely((cmd & RXD_ERR_CODE) || pkg_len < ETH_ZLEN + 4)) {
> + stats->rx_length_errors++;
> + stats->rx_dropped++;
> + goto spl2sw_rx_poll_rec_err;
> + }
> +
> + dma_unmap_single(&comm->pdev->dev, sinfo->mapping,
> + comm->rx_desc_buff_size, DMA_FROM_DEVICE);
> +
> + skb = sinfo->skb;
> + skb_put(skb, pkg_len - 4); /* Minus FCS */
> + skb->ip_summed = CHECKSUM_NONE;
> + skb->protocol = eth_type_trans(skb, comm->ndev[port]);
> + netif_receive_skb(skb);
> +
> + stats->rx_packets++;
> + stats->rx_bytes += skb->len;
> +
> + /* Allocate a new skb for receiving. */
> + new_skb = netdev_alloc_skb(NULL, comm->rx_desc_buff_size);
> + if (unlikely(!new_skb)) {
> + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> + RXD_EOR : 0;
> + sinfo->skb = NULL;
> + sinfo->mapping = 0;
> + desc->addr1 = 0;
> + goto spl2sw_rx_poll_alloc_err;
> + }
> +
> + sinfo->mapping = dma_map_single(&comm->pdev->dev, new_skb->data,
> + comm->rx_desc_buff_size,
> + DMA_FROM_DEVICE);
> + if (dma_mapping_error(&comm->pdev->dev, sinfo->mapping)) {
> + dev_kfree_skb_irq(new_skb);
> + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> + RXD_EOR : 0;
> + sinfo->skb = NULL;
> + sinfo->mapping = 0;
> + desc->addr1 = 0;
> + goto spl2sw_rx_poll_alloc_err;
> + }
> +
> + sinfo->skb = new_skb;
> + desc->addr1 = sinfo->mapping;
> +
> +spl2sw_rx_poll_rec_err:
> + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> + RXD_EOR | comm->rx_desc_buff_size :
> + comm->rx_desc_buff_size;
> +
> + wmb(); /* Set RXD_OWN after other fields are effective. */
> + desc->cmd1 = RXD_OWN;
> +
> +spl2sw_rx_poll_alloc_err:
> + /* Move rx_pos to next position */
> + rx_pos = ((rx_pos + 1) == comm->rx_desc_num[queue]) ? 0 : rx_pos + 1;
> +
> + budget_left--;
> +
> + /* If there are packets in high-priority queue,
> + * stop processing low-priority queue.
> + */
> + if (queue == 1 && !(h_desc->cmd1 & RXD_OWN))
> + break;
> + }
> +
> + comm->rx_pos[queue] = rx_pos;
> +
> + /* Save pointer to last rx descriptor of high-priority queue. */
> + if (queue == 0)
> + h_desc = comm->rx_desc[queue] + rx_pos;
> + }
> +
> + wmb(); /* make sure settings are effective. */
> + mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> + mask &= ~MAC_INT_RX;
> + writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> +
> + napi_complete(napi);
> + return 0;
> +}
> +
> +int spl2sw_tx_poll(struct napi_struct *napi, int budget)
> +{
> + struct spl2sw_common *comm = container_of(napi, struct spl2sw_common, tx_napi);
> + struct spl2sw_skb_info *skbinfo;
> + struct net_device_stats *stats;
> + int budget_left = budget;
> + u32 tx_done_pos;
> + u32 mask;
> + u32 cmd;
> + int i;
> +
> + spin_lock(&comm->tx_lock);
> +
> + tx_done_pos = comm->tx_done_pos;
> + while (((tx_done_pos != comm->tx_pos) || (comm->tx_desc_full == 1)) && budget_left) {
> + cmd = comm->tx_desc[tx_done_pos].cmd1;
> + if (cmd & TXD_OWN)
> + break;
> +
> + skbinfo = &comm->tx_temp_skb_info[tx_done_pos];
> + if (unlikely(!skbinfo->skb))
> + goto spl2sw_tx_poll_next;
> +
> + i = ffs(FIELD_GET(TXD_VLAN, cmd)) - 1;
> + if (i < MAX_NETDEV_NUM && comm->ndev[i])
> + stats = &comm->ndev[i]->stats;
> + else
> + goto spl2sw_tx_poll_unmap;
> +
> + if (unlikely(cmd & (TXD_ERR_CODE))) {
> + stats->tx_errors++;
> + } else {
> + stats->tx_packets++;
> + stats->tx_bytes += skbinfo->len;
> + }
> +
> +spl2sw_tx_poll_unmap:
> + dma_unmap_single(&comm->pdev->dev, skbinfo->mapping, skbinfo->len,
> + DMA_TO_DEVICE);
> + skbinfo->mapping = 0;
> + dev_kfree_skb_irq(skbinfo->skb);
> + skbinfo->skb = NULL;
> +
> +spl2sw_tx_poll_next:
> + /* Move tx_done_pos to next position */
> + tx_done_pos = ((tx_done_pos + 1) == TX_DESC_NUM) ? 0 : tx_done_pos + 1;
> +
> + if (comm->tx_desc_full == 1)
> + comm->tx_desc_full = 0;
> +
> + budget_left--;
> + }
> +
> + comm->tx_done_pos = tx_done_pos;
> + if (!comm->tx_desc_full)
> + for (i = 0; i < MAX_NETDEV_NUM; i++)
> + if (comm->ndev[i])
> + if (netif_queue_stopped(comm->ndev[i]))
> + netif_wake_queue(comm->ndev[i]);
> +
> + spin_unlock(&comm->tx_lock);
> +
> + wmb(); /* make sure settings are effective. */
> + mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> + mask &= ~MAC_INT_TX;
> + writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> +
> + napi_complete(napi);
> + return 0;
> +}

This doesn't look like it is doing NAPI properly.

The driver is supposed to return the amount of packets processed.
If budget is used, it should return budget.


2022-04-26 04:07:30

by Wells Lu 呂芳騰

[permalink] [raw]
Subject: RE: [PATCH net-next v9 2/2] net: ethernet: Add driver for Sunplus SP7021

Hi Stephen,


> > +int spl2sw_rx_poll(struct napi_struct *napi, int budget) {
> > + struct spl2sw_common *comm = container_of(napi, struct spl2sw_common, rx_napi);
> > + struct spl2sw_mac_desc *desc, *h_desc;
> > + struct net_device_stats *stats;
> > + struct sk_buff *skb, *new_skb;
> > + struct spl2sw_skb_info *sinfo;
> > + int budget_left = budget;
> > + u32 rx_pos, pkg_len;
> > + u32 num, rx_count;
> > + s32 queue;
> > + u32 mask;
> > + int port;
> > + u32 cmd;
> > +
> > + /* Process high-priority queue and then low-priority queue. */
> > + for (queue = 0; queue < RX_DESC_QUEUE_NUM; queue++) {
> > + rx_pos = comm->rx_pos[queue];
> > + rx_count = comm->rx_desc_num[queue];
> > +
> > + for (num = 0; num < rx_count && budget_left; num++) {
> > + sinfo = comm->rx_skb_info[queue] + rx_pos;
> > + desc = comm->rx_desc[queue] + rx_pos;
> > + cmd = desc->cmd1;
> > +
> > + if (cmd & RXD_OWN)
> > + break;
> > +
> > + port = FIELD_GET(RXD_PKT_SP, cmd);
> > + if (port < MAX_NETDEV_NUM && comm->ndev[port])
> > + stats = &comm->ndev[port]->stats;
> > + else
> > + goto spl2sw_rx_poll_rec_err;
> > +
> > + pkg_len = FIELD_GET(RXD_PKT_LEN, cmd);
> > + if (unlikely((cmd & RXD_ERR_CODE) || pkg_len < ETH_ZLEN + 4)) {
> > + stats->rx_length_errors++;
> > + stats->rx_dropped++;
> > + goto spl2sw_rx_poll_rec_err;
> > + }
> > +
> > + dma_unmap_single(&comm->pdev->dev, sinfo->mapping,
> > + comm->rx_desc_buff_size, DMA_FROM_DEVICE);
> > +
> > + skb = sinfo->skb;
> > + skb_put(skb, pkg_len - 4); /* Minus FCS */
> > + skb->ip_summed = CHECKSUM_NONE;
> > + skb->protocol = eth_type_trans(skb, comm->ndev[port]);
> > + netif_receive_skb(skb);
> > +
> > + stats->rx_packets++;
> > + stats->rx_bytes += skb->len;
> > +
> > + /* Allocate a new skb for receiving. */
> > + new_skb = netdev_alloc_skb(NULL, comm->rx_desc_buff_size);
> > + if (unlikely(!new_skb)) {
> > + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> > + RXD_EOR : 0;
> > + sinfo->skb = NULL;
> > + sinfo->mapping = 0;
> > + desc->addr1 = 0;
> > + goto spl2sw_rx_poll_alloc_err;
> > + }
> > +
> > + sinfo->mapping = dma_map_single(&comm->pdev->dev, new_skb->data,
> > + comm->rx_desc_buff_size,
> > + DMA_FROM_DEVICE);
> > + if (dma_mapping_error(&comm->pdev->dev, sinfo->mapping)) {
> > + dev_kfree_skb_irq(new_skb);
> > + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> > + RXD_EOR : 0;
> > + sinfo->skb = NULL;
> > + sinfo->mapping = 0;
> > + desc->addr1 = 0;
> > + goto spl2sw_rx_poll_alloc_err;
> > + }
> > +
> > + sinfo->skb = new_skb;
> > + desc->addr1 = sinfo->mapping;
> > +
> > +spl2sw_rx_poll_rec_err:
> > + desc->cmd2 = (rx_pos == comm->rx_desc_num[queue] - 1) ?
> > + RXD_EOR | comm->rx_desc_buff_size :
> > + comm->rx_desc_buff_size;
> > +
> > + wmb(); /* Set RXD_OWN after other fields are effective. */
> > + desc->cmd1 = RXD_OWN;
> > +
> > +spl2sw_rx_poll_alloc_err:
> > + /* Move rx_pos to next position */
> > + rx_pos = ((rx_pos + 1) == comm->rx_desc_num[queue]) ? 0 : rx_pos +
> > +1;
> > +
> > + budget_left--;
> > +
> > + /* If there are packets in high-priority queue,
> > + * stop processing low-priority queue.
> > + */
> > + if (queue == 1 && !(h_desc->cmd1 & RXD_OWN))
> > + break;
> > + }
> > +
> > + comm->rx_pos[queue] = rx_pos;
> > +
> > + /* Save pointer to last rx descriptor of high-priority queue. */
> > + if (queue == 0)
> > + h_desc = comm->rx_desc[queue] + rx_pos;
> > + }
> > +
> > + wmb(); /* make sure settings are effective. */
> > + mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> > + mask &= ~MAC_INT_RX;
> > + writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> > +
> > + napi_complete(napi);
> > + return 0;
> > +}
> > +
> > +int spl2sw_tx_poll(struct napi_struct *napi, int budget) {
> > + struct spl2sw_common *comm = container_of(napi, struct spl2sw_common, tx_napi);
> > + struct spl2sw_skb_info *skbinfo;
> > + struct net_device_stats *stats;
> > + int budget_left = budget;
> > + u32 tx_done_pos;
> > + u32 mask;
> > + u32 cmd;
> > + int i;
> > +
> > + spin_lock(&comm->tx_lock);
> > +
> > + tx_done_pos = comm->tx_done_pos;
> > + while (((tx_done_pos != comm->tx_pos) || (comm->tx_desc_full == 1)) && budget_left)
> {
> > + cmd = comm->tx_desc[tx_done_pos].cmd1;
> > + if (cmd & TXD_OWN)
> > + break;
> > +
> > + skbinfo = &comm->tx_temp_skb_info[tx_done_pos];
> > + if (unlikely(!skbinfo->skb))
> > + goto spl2sw_tx_poll_next;
> > +
> > + i = ffs(FIELD_GET(TXD_VLAN, cmd)) - 1;
> > + if (i < MAX_NETDEV_NUM && comm->ndev[i])
> > + stats = &comm->ndev[i]->stats;
> > + else
> > + goto spl2sw_tx_poll_unmap;
> > +
> > + if (unlikely(cmd & (TXD_ERR_CODE))) {
> > + stats->tx_errors++;
> > + } else {
> > + stats->tx_packets++;
> > + stats->tx_bytes += skbinfo->len;
> > + }
> > +
> > +spl2sw_tx_poll_unmap:
> > + dma_unmap_single(&comm->pdev->dev, skbinfo->mapping, skbinfo->len,
> > + DMA_TO_DEVICE);
> > + skbinfo->mapping = 0;
> > + dev_kfree_skb_irq(skbinfo->skb);
> > + skbinfo->skb = NULL;
> > +
> > +spl2sw_tx_poll_next:
> > + /* Move tx_done_pos to next position */
> > + tx_done_pos = ((tx_done_pos + 1) == TX_DESC_NUM) ? 0 : tx_done_pos
> > ++ 1;
> > +
> > + if (comm->tx_desc_full == 1)
> > + comm->tx_desc_full = 0;
> > +
> > + budget_left--;
> > + }
> > +
> > + comm->tx_done_pos = tx_done_pos;
> > + if (!comm->tx_desc_full)
> > + for (i = 0; i < MAX_NETDEV_NUM; i++)
> > + if (comm->ndev[i])
> > + if (netif_queue_stopped(comm->ndev[i]))
> > + netif_wake_queue(comm->ndev[i]);
> > +
> > + spin_unlock(&comm->tx_lock);
> > +
> > + wmb(); /* make sure settings are effective. */
> > + mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> > + mask &= ~MAC_INT_TX;
> > + writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
> > +
> > + napi_complete(napi);
> > + return 0;
> > +}
>
> This doesn't look like it is doing NAPI properly.
>
> The driver is supposed to return the amount of packets processed.
> If budget is used, it should return budget.

I'll modify code to return the amount of processed packets:

return budge - budget_left;


Thank you for your review.


Best regards,
Wells