net: lantiq: add support for jumbo frames

Add support for jumbo frames. Full support for jumbo frames requires
changes in the DSA switch driver (lantiq_gswip.c).

Tested on BT Hone Hub 5A.

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 5d96248..9b7307e 100644 (file)
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -14,13 +14,15 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 
+#include <linux/if_vlan.h>
+
 #include <linux/of_net.h>
 #include <linux/of_platform.h>
 
 #include <xway_dma.h>
 
 /* DMA */
-#define XRX200_DMA_DATA_LEN    0x600
+#define XRX200_DMA_DATA_LEN    (SZ_64K - 1)
 #define XRX200_DMA_RX          0
 #define XRX200_DMA_TX          1
 
@@ -109,7 +111,8 @@ static void xrx200_flush_dma(struct xrx200_chan *ch)
                        break;
 
                desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
-                           XRX200_DMA_DATA_LEN;
+                           (ch->priv->net_dev->mtu + VLAN_ETH_HLEN +
+                            ETH_FCS_LEN);
                ch->dma.desc++;
                ch->dma.desc %= LTQ_DESC_NUM;
        }
@@ -157,19 +160,20 @@ static int xrx200_close(struct net_device *net_dev)
 
 static int xrx200_alloc_skb(struct xrx200_chan *ch)
 {
+       int len = ch->priv->net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
        struct sk_buff *skb = ch->skb[ch->dma.desc];
        dma_addr_t mapping;
        int ret = 0;
 
        ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
-                                                         XRX200_DMA_DATA_LEN);
+                                                         len);
        if (!ch->skb[ch->dma.desc]) {
                ret = -ENOMEM;
                goto skip;
        }
 
        mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
-                                XRX200_DMA_DATA_LEN, DMA_FROM_DEVICE);
+                                len, DMA_FROM_DEVICE);
        if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
                dev_kfree_skb_any(ch->skb[ch->dma.desc]);
                ch->skb[ch->dma.desc] = skb;
@@ -182,8 +186,7 @@ static int xrx200_alloc_skb(struct xrx200_chan *ch)
        wmb();
 skip:
        ch->dma.desc_base[ch->dma.desc].ctl =
-               LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
-               XRX200_DMA_DATA_LEN;
+               LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | len;
 
        return ret;
 }
@@ -343,10 +346,57 @@ err_drop:
        return NETDEV_TX_OK;
 }
 
+static int
+xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
+{
+       struct xrx200_priv *priv = netdev_priv(net_dev);
+       struct xrx200_chan *ch_rx = &priv->chan_rx;
+       int old_mtu = net_dev->mtu;
+       bool running = false;
+       struct sk_buff *skb;
+       int curr_desc;
+       int ret = 0;
+
+       net_dev->mtu = new_mtu;
+
+       if (new_mtu <= old_mtu)
+               return ret;
+
+       running = netif_running(net_dev);
+       if (running) {
+               napi_disable(&ch_rx->napi);
+               ltq_dma_close(&ch_rx->dma);
+       }
+
+       xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
+       curr_desc = ch_rx->dma.desc;
+
+       for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
+            ch_rx->dma.desc++) {
+               skb = ch_rx->skb[ch_rx->dma.desc];
+               ret = xrx200_alloc_skb(ch_rx);
+               if (ret) {
+                       net_dev->mtu = old_mtu;
+                       break;
+               }
+               dev_kfree_skb_any(skb);
+       }
+
+       ch_rx->dma.desc = curr_desc;
+       if (running) {
+               napi_enable(&ch_rx->napi);
+               ltq_dma_open(&ch_rx->dma);
+               ltq_dma_enable_irq(&ch_rx->dma);
+       }
+
+       return ret;
+}
+
 static const struct net_device_ops xrx200_netdev_ops = {
        .ndo_open               = xrx200_open,
        .ndo_stop               = xrx200_close,
        .ndo_start_xmit         = xrx200_start_xmit,
+       .ndo_change_mtu         = xrx200_change_mtu,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_validate_addr      = eth_validate_addr,
 };
@@ -456,7 +506,7 @@ static int xrx200_probe(struct platform_device *pdev)
        net_dev->netdev_ops = &xrx200_netdev_ops;
        SET_NETDEV_DEV(net_dev, dev);
        net_dev->min_mtu = ETH_ZLEN;
-       net_dev->max_mtu = XRX200_DMA_DATA_LEN;
+       net_dev->max_mtu = XRX200_DMA_DATA_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;
 
        /* load the memory ranges */
        priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);