On 9/23/21 5:08 PM, Biju Das wrote:
> This patch series adds RX(packet receive) function for
> Gigabit Ethernet found on RZ/G2L SoC.
>
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/renesas/ravb.h | 1 +
> drivers/net/ethernet/renesas/ravb_main.c | 157 ++++++++++++++++++++++-
> 2 files changed, 156 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
> index b0e067a6a8ee..85260f89e1cd 100644
> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -1092,6 +1092,7 @@ struct ravb_private {
>
> int duplex;
> struct ravb_rx_desc *rgeth_rx_ring[NUM_RX_QUEUE];
> + struct sk_buff *rxtop_skb;
I'd prefer for this one declared earler in the *struct*, as well. And why not e.g 'rx_1st_skb'?
>
> const struct ravb_hw_info *info;
> struct reset_control *rstc;
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index a08da7a37b92..867e180e6655 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -705,6 +705,23 @@ static void ravb_get_tx_tstamp(struct net_device *ndev)
> }
> }
>
> +static void ravb_rx_csum_rgeth(struct sk_buff *skb)
> +{
> + u8 *hw_csum;
> +
> + /* The hardware checksum is contained in sizeof(__sum16) (2) bytes
> + * appended to packet data
> + */
> + if (unlikely(skb->len < sizeof(__sum16)))
> + return;
> + hw_csum = skb_tail_pointer(skb) - sizeof(__sum16);
> +
> + if (*hw_csum == 0)
> + skb->ip_summed = CHECKSUM_UNNECESSARY;
> + else
> + skb->ip_summed = CHECKSUM_NONE;
Mhm, what's the point of this whole function then? Why it can't be a copy of the R-Car analog?
[...]
> @@ -720,11 +737,147 @@ static void ravb_rx_csum(struct sk_buff *skb)
[...]
> /* Packet receive function for Gigabit Ethernet */
> static bool ravb_rgeth_rx(struct net_device *ndev, int *quota, int q)
> {
> - /* Place holder */
> - return true;
> + struct ravb_private *priv = netdev_priv(ndev);
> + int entry = priv->cur_rx[q] % priv->num_rx_ring[q];
> + int boguscnt = priv->dirty_rx[q] + priv->num_rx_ring[q] - priv->cur_rx[q];
> + struct net_device_stats *stats = &priv->stats[q];
[q] should be dropped, as we've agreed...
> + struct ravb_rx_desc *desc;
> + struct sk_buff *skb;
> + dma_addr_t dma_addr;
> + u8 desc_status;
> + u8 die_dt;
> + u16 pkt_len;
> + int limit;
> +
> + boguscnt = min(boguscnt, *quota);
> + limit = boguscnt;
> + desc = &priv->rgeth_rx_ring[q][entry];
> + while (desc->die_dt != DT_FEMPTY) {
> + /* Descriptor type must be checked before all other reads */
> + dma_rmb();
> + desc_status = desc->msc;
> + pkt_len = le16_to_cpu(desc->ds_cc) & RX_DS;
> +
> + if (--boguscnt < 0)
> + break;
> +
> + /* We use 0-byte descriptors to mark the DMA mapping errors */
> + if (!pkt_len)
> + continue;
> +
> + if (desc_status & MSC_MC)
> + stats->multicast++;
> +
> + if (desc_status & (MSC_CRC | MSC_RFE | MSC_RTSF | MSC_RTLF | MSC_CEEF)) {
> + stats->rx_errors++;
> + if (desc_status & MSC_CRC)
> + stats->rx_crc_errors++;
> + if (desc_status & MSC_RFE)
> + stats->rx_frame_errors++;
> + if (desc_status & (MSC_RTLF | MSC_RTSF))
> + stats->rx_length_errors++;
> + if (desc_status & MSC_CEEF)
> + stats->rx_missed_errors++;
> + } else {
> + die_dt = desc->die_dt & 0xF0;
> + switch (die_dt) {
> + case DT_FSINGLE:
> + skb = ravb_get_skb_rgeth(ndev, q, entry, desc);
> + skb_put(skb, pkt_len);
> + skb->protocol = eth_type_trans(skb, ndev);
> + if (ndev->features & NETIF_F_RXCSUM)
> + ravb_rx_csum_rgeth(skb);
> + napi_gro_receive(&priv->napi[q], skb);
> + stats->rx_packets++;
> + stats->rx_bytes += pkt_len;
> + break;
> + case DT_FSTART:
> + priv->rxtop_skb = ravb_get_skb_rgeth(ndev, q, entry, desc);
But don't you need to copy the data in this case?
> + skb_put(priv->rxtop_skb, pkt_len);
> + break;
> + case DT_FMID:
> + skb = ravb_get_skb_rgeth(ndev, q, entry, desc);
> + skb_copy_to_linear_data_offset(priv->rxtop_skb,
> + priv->rxtop_skb->len,
> + skb->data,
> + pkt_len);
> + skb_put(priv->rxtop_skb, pkt_len);
> + dev_kfree_skb(skb);
> + break;
> + case DT_FEND:
> + skb = ravb_get_skb_rgeth(ndev, q, entry, desc);
> + skb_copy_to_linear_data_offset(priv->rxtop_skb,
> + priv->rxtop_skb->len,
> + skb->data,
> + pkt_len);
> + skb_put(priv->rxtop_skb, pkt_len);
> + dev_kfree_skb(skb);
> + priv->rxtop_skb->protocol =
> + eth_type_trans(priv->rxtop_skb, ndev);
> + if (ndev->features & NETIF_F_RXCSUM)
> + ravb_rx_csum_rgeth(skb);
> + napi_gro_receive(&priv->napi[q],
> + priv->rxtop_skb);
> + stats->rx_packets++;
> + stats->rx_bytes += priv->rxtop_skb->len;
> + break;
> + }
> + }
> +
> + entry = (++priv->cur_rx[q]) % priv->num_rx_ring[q];
> + desc = &priv->rgeth_rx_ring[q][entry];
> + }
> +
> + /* Refill the RX ring buffers. */
> + for (; priv->cur_rx[q] - priv->dirty_rx[q] > 0; priv->dirty_rx[q]++) {
> + entry = priv->dirty_rx[q] % priv->num_rx_ring[q];
> + desc = &priv->rgeth_rx_ring[q][entry];
> + desc->ds_cc = cpu_to_le16(RGETH_RX_DESC_DATA_SIZE);
> +
> + if (!priv->rx_skb[q][entry]) {
> + skb = netdev_alloc_skb(ndev,
> + RGETH_RX_BUFF_MAX + RAVB_ALIGN - 1);
ALIGN(RGETH_RX_BUFF_MAX, RAVB_ALIGN)?
[...]
MBR, Sergey
