target/linux/lantiq/patches-5.10/0702-v5.16-net-lantiq-add-support-for-jumbo-frames.patch

   1 From 998ac358019e491217e752bc6dcbb3afb2a6fa3e Mon Sep 17 00:00:00 2001
   2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
   3 Date: Sun, 19 Sep 2021 20:24:28 +0200
   4 Subject: [PATCH] net: lantiq: add support for jumbo frames
   5
   6 Add support for jumbo frames. Full support for jumbo frames requires
   7 changes in the DSA switch driver (lantiq_gswip.c).
   8
   9 Tested on BT Hone Hub 5A.
  10
  11 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  12 Signed-off-by: David S. Miller <davem@davemloft.net>
  13 ---
  14  drivers/net/ethernet/lantiq_xrx200.c | 64 +++++++++++++++++++++++++---
  15  1 file changed, 57 insertions(+), 7 deletions(-)
  16
  17 --- a/drivers/net/ethernet/lantiq_xrx200.c
  18 +++ b/drivers/net/ethernet/lantiq_xrx200.c
  19 @@ -14,13 +14,15 @@
  20  #include <linux/clk.h>
  21  #include <linux/delay.h>
  22
  23 +#include <linux/if_vlan.h>
  24 +
  25  #include <linux/of_net.h>
  26  #include <linux/of_platform.h>
  27
  28  #include <xway_dma.h>
  29
  30  /* DMA */
  31 -#define XRX200_DMA_DATA_LEN    0x600
  32 +#define XRX200_DMA_DATA_LEN    (SZ_64K - 1)
  33  #define XRX200_DMA_RX          0
  34  #define XRX200_DMA_TX          1
  35
  36 @@ -106,7 +108,8 @@ static void xrx200_flush_dma(struct xrx2
  37                         break;
  38
  39                 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
  40 -                           XRX200_DMA_DATA_LEN;
  41 +                           (ch->priv->net_dev->mtu + VLAN_ETH_HLEN +
  42 +                            ETH_FCS_LEN);
  43                 ch->dma.desc++;
  44                 ch->dma.desc %= LTQ_DESC_NUM;
  45         }
  46 @@ -154,19 +157,20 @@ static int xrx200_close(struct net_devic
  47
  48  static int xrx200_alloc_skb(struct xrx200_chan *ch)
  49  {
  50 +       int len = ch->priv->net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
  51         struct sk_buff *skb = ch->skb[ch->dma.desc];
  52         dma_addr_t mapping;
  53         int ret = 0;
  54
  55         ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
  56 -                                                         XRX200_DMA_DATA_LEN);
  57 +                                                         len);
  58         if (!ch->skb[ch->dma.desc]) {
  59                 ret = -ENOMEM;
  60                 goto skip;
  61         }
  62
  63         mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
  64 -                                XRX200_DMA_DATA_LEN, DMA_FROM_DEVICE);
  65 +                                len, DMA_FROM_DEVICE);
  66         if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
  67                 dev_kfree_skb_any(ch->skb[ch->dma.desc]);
  68                 ch->skb[ch->dma.desc] = skb;
  69 @@ -179,8 +183,7 @@ static int xrx200_alloc_skb(struct xrx20
  70         wmb();
  71  skip:
  72         ch->dma.desc_base[ch->dma.desc].ctl =
  73 -               LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
  74 -               XRX200_DMA_DATA_LEN;
  75 +               LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | len;
  76
  77         return ret;
  78  }
  79 @@ -340,10 +343,57 @@ err_drop:
  80         return NETDEV_TX_OK;
  81  }
  82
  83 +static int
  84 +xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
  85 +{
  86 +       struct xrx200_priv *priv = netdev_priv(net_dev);
  87 +       struct xrx200_chan *ch_rx = &priv->chan_rx;
  88 +       int old_mtu = net_dev->mtu;
  89 +       bool running = false;
  90 +       struct sk_buff *skb;
  91 +       int curr_desc;
  92 +       int ret = 0;
  93 +
  94 +       net_dev->mtu = new_mtu;
  95 +
  96 +       if (new_mtu <= old_mtu)
  97 +               return ret;
  98 +
  99 +       running = netif_running(net_dev);
 100 +       if (running) {
 101 +               napi_disable(&ch_rx->napi);
 102 +               ltq_dma_close(&ch_rx->dma);
 103 +       }
 104 +
 105 +       xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
 106 +       curr_desc = ch_rx->dma.desc;
 107 +
 108 +       for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
 109 +            ch_rx->dma.desc++) {
 110 +               skb = ch_rx->skb[ch_rx->dma.desc];
 111 +               ret = xrx200_alloc_skb(ch_rx);
 112 +               if (ret) {
 113 +                       net_dev->mtu = old_mtu;
 114 +                       break;
 115 +               }
 116 +               dev_kfree_skb_any(skb);
 117 +       }
 118 +
 119 +       ch_rx->dma.desc = curr_desc;
 120 +       if (running) {
 121 +               napi_enable(&ch_rx->napi);
 122 +               ltq_dma_open(&ch_rx->dma);
 123 +               ltq_dma_enable_irq(&ch_rx->dma);
 124 +       }
 125 +
 126 +       return ret;
 127 +}
 128 +
 129  static const struct net_device_ops xrx200_netdev_ops = {
 130         .ndo_open               = xrx200_open,
 131         .ndo_stop               = xrx200_close,
 132         .ndo_start_xmit         = xrx200_start_xmit,
 133 +       .ndo_change_mtu         = xrx200_change_mtu,
 134         .ndo_set_mac_address    = eth_mac_addr,
 135         .ndo_validate_addr      = eth_validate_addr,
 136  };
 137 @@ -454,7 +504,7 @@ static int xrx200_probe(struct platform_
 138         net_dev->netdev_ops = &xrx200_netdev_ops;
 139         SET_NETDEV_DEV(net_dev, dev);
 140         net_dev->min_mtu = ETH_ZLEN;
 141 -       net_dev->max_mtu = XRX200_DMA_DATA_LEN;
 142 +       net_dev->max_mtu = XRX200_DMA_DATA_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;
 143
 144         /* load the memory ranges */
 145         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);