ar71xx: fix off-by-one error in packet descriptor splitting (patch from #13072)
[openwrt/staging/lynxis/omap.git] / target / linux / ar71xx / files / drivers / net / ethernet / atheros / ag71xx / ag71xx_main.c
index aa1fb9ef5bbe3268741871dbb30e6ad03a09abac..c04fb94b94e30b757d877c1b621c513193336665 100644 (file)
@@ -28,6 +28,13 @@ static int ag71xx_msg_level = -1;
 module_param_named(msg_level, ag71xx_msg_level, int, 0);
 MODULE_PARM_DESC(msg_level, "Message level (-1=defaults,0=none,...,16=all)");
 
+#define ETH_SWITCH_HEADER_LEN  2
+
+static inline unsigned int ag71xx_max_frame_len(unsigned int mtu)
+{
+       return ETH_SWITCH_HEADER_LEN + ETH_HLEN + VLAN_HLEN + mtu + ETH_FCS_LEN;
+}
+
 static void ag71xx_dump_dma_regs(struct ag71xx *ag)
 {
        DBG("%s: dma_tx_ctrl=%08x, dma_tx_desc=%08x, dma_tx_status=%08x\n",
@@ -145,7 +152,7 @@ static void ag71xx_ring_tx_clean(struct ag71xx *ag)
                }
 
                if (ring->buf[i].skb) {
-                       bytes_compl += ring->buf[i].skb->len;
+                       bytes_compl += ring->buf[i].len;
                        pkts_compl++;
                        dev_kfree_skb_any(ring->buf[i].skb);
                }
@@ -191,7 +198,7 @@ static void ag71xx_ring_rx_clean(struct ag71xx *ag)
        for (i = 0; i < ring->size; i++)
                if (ring->buf[i].rx_buf) {
                        dma_unmap_single(&ag->dev->dev, ring->buf[i].dma_addr,
-                                        AG71XX_RX_BUF_SIZE, DMA_FROM_DEVICE);
+                                        ag->rx_buf_size, DMA_FROM_DEVICE);
                        kfree(ring->buf[i].rx_buf);
                }
 }
@@ -217,15 +224,15 @@ static bool ag71xx_fill_rx_buf(struct ag71xx *ag, struct ag71xx_buf *buf,
 {
        void *data;
 
-       data = kmalloc(AG71XX_RX_BUF_SIZE +
+       data = kmalloc(ag->rx_buf_size +
                       SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
                       GFP_ATOMIC);
        if (!data)
                return false;
 
        buf->rx_buf = data;
-       buf->dma_addr = dma_map_single(&ag->dev->dev, data,
-                                      AG71XX_RX_BUF_SIZE, DMA_FROM_DEVICE);
+       buf->dma_addr = dma_map_single(&ag->dev->dev, data, ag->rx_buf_size,
+                                      DMA_FROM_DEVICE);
        buf->desc->data = (u32) buf->dma_addr + offset;
        return true;
 }
@@ -433,8 +440,8 @@ static void ag71xx_hw_setup(struct ag71xx *ag)
        ag71xx_sb(ag, AG71XX_REG_MAC_CFG2,
                  MAC_CFG2_PAD_CRC_EN | MAC_CFG2_LEN_CHECK);
 
-       /* setup max frame length */
-       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, AG71XX_TX_MTU_LEN);
+       /* setup max frame length to zero */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, 0);
 
        /* setup FIFO configuration registers */
        ag71xx_wr(ag, AG71XX_REG_FIFO_CFG0, FIFO_CFG0_INIT);
@@ -503,6 +510,10 @@ static void ag71xx_fast_reset(struct ag71xx *ag)
        ag71xx_dma_reset(ag);
        ag71xx_hw_setup(ag);
 
+       /* setup max frame length */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL,
+                 ag71xx_max_frame_len(ag->dev->mtu));
+
        ag71xx_wr(ag, AG71XX_REG_RX_DESC, rx_ds);
        ag71xx_wr(ag, AG71XX_REG_TX_DESC, tx_ds);
        ag71xx_wr(ag, AG71XX_REG_MII_CFG, mii_reg);
@@ -525,6 +536,7 @@ void ag71xx_link_adjust(struct ag71xx *ag)
        u32 cfg2;
        u32 ifctl;
        u32 fifo5;
+       u32 fifo3;
 
        if (!ag->link) {
                ag71xx_hw_stop(ag);
@@ -565,11 +577,18 @@ void ag71xx_link_adjust(struct ag71xx *ag)
        }
 
        if (pdata->is_ar91xx)
-               ag71xx_wr(ag, AG71XX_REG_FIFO_CFG3, 0x00780fff);
+               fifo3 = 0x00780fff;
        else if (pdata->is_ar724x)
-               ag71xx_wr(ag, AG71XX_REG_FIFO_CFG3, pdata->fifo_cfg3);
+               fifo3 = pdata->fifo_cfg3;
        else
-               ag71xx_wr(ag, AG71XX_REG_FIFO_CFG3, 0x008001ff);
+               fifo3 = 0x008001ff;
+
+       if (ag->tx_ring.desc_split) {
+               fifo3 &= 0xffff;
+               fifo3 |= ((2048 - ag->tx_ring.desc_split) / 4) << 16;
+       }
+
+       ag71xx_wr(ag, AG71XX_REG_FIFO_CFG3, fifo3);
 
        if (pdata->set_speed)
                pdata->set_speed(ag->speed);
@@ -607,8 +626,15 @@ void ag71xx_link_adjust(struct ag71xx *ag)
 static int ag71xx_open(struct net_device *dev)
 {
        struct ag71xx *ag = netdev_priv(dev);
+       unsigned int max_frame_len;
        int ret;
 
+       max_frame_len = ag71xx_max_frame_len(dev->mtu);
+       ag->rx_buf_size = max_frame_len + NET_SKB_PAD + NET_IP_ALIGN;
+
+       /* setup max frame length */
+       ag71xx_wr(ag, AG71XX_REG_MAC_MFL, max_frame_len);
+
        ret = ag71xx_rings_init(ag);
        if (ret)
                goto err;
@@ -657,6 +683,54 @@ static int ag71xx_stop(struct net_device *dev)
        return 0;
 }
 
+static int ag71xx_fill_dma_desc(struct ag71xx_ring *ring, u32 addr, int len)
+{
+       int i;
+       struct ag71xx_desc *desc;
+       int ndesc = 0;
+       int split = ring->desc_split;
+
+       if (!split)
+               split = len;
+
+       while (len > 0) {
+               unsigned int cur_len = len;
+
+               i = (ring->curr + ndesc) % ring->size;
+               desc = ring->buf[i].desc;
+
+               if (!ag71xx_desc_empty(desc))
+                       return -1;
+
+               if (cur_len > split) {
+                       cur_len = split;
+
+                       /*
+                        * TX will hang if DMA transfers <= 4 bytes,
+                        * make sure next segment is more than 4 bytes long.
+                        */
+                       if (len <= split + 4)
+                               cur_len -= 4;
+               }
+
+               desc->data = addr;
+               addr += cur_len;
+               len -= cur_len;
+
+               if (len > 0)
+                       cur_len |= DESC_MORE;
+
+               /* prevent early tx attempt of this descriptor */
+               if (!ndesc)
+                       cur_len |= DESC_EMPTY;
+
+               desc->ctrl = cur_len;
+               ndesc++;
+       }
+
+       return ndesc;
+}
+
 static netdev_tx_t ag71xx_hard_start_xmit(struct sk_buff *skb,
                                          struct net_device *dev)
 {
@@ -664,18 +738,12 @@ static netdev_tx_t ag71xx_hard_start_xmit(struct sk_buff *skb,
        struct ag71xx_ring *ring = &ag->tx_ring;
        struct ag71xx_desc *desc;
        dma_addr_t dma_addr;
-       int i;
-
-       i = ring->curr % ring->size;
-       desc = ring->buf[i].desc;
-
-       if (!ag71xx_desc_empty(desc))
-               goto err_drop;
+       int i, n, ring_min;
 
        if (ag71xx_has_ar8216(ag))
                ag71xx_add_ar8216_header(ag, skb);
 
-       if (skb->len <= 0) {
+       if (skb->len <= 4) {
                DBG("%s: packet len is too small\n", ag->dev->name);
                goto err_drop;
        }
@@ -683,20 +751,33 @@ static netdev_tx_t ag71xx_hard_start_xmit(struct sk_buff *skb,
        dma_addr = dma_map_single(&dev->dev, skb->data, skb->len,
                                  DMA_TO_DEVICE);
 
-       netdev_sent_queue(dev, skb->len);
+       i = ring->curr % ring->size;
+       desc = ring->buf[i].desc;
+
+       /* setup descriptor fields */
+       n = ag71xx_fill_dma_desc(ring, (u32) dma_addr, skb->len & ag->desc_pktlen_mask);
+       if (n < 0)
+               goto err_drop_unmap;
+
+       i = (ring->curr + n - 1) % ring->size;
+       ring->buf[i].len = skb->len;
        ring->buf[i].skb = skb;
        ring->buf[i].timestamp = jiffies;
 
-       /* setup descriptor fields */
-       desc->data = (u32) dma_addr;
-       desc->ctrl = (skb->len & DESC_PKTLEN_M);
+       netdev_sent_queue(dev, skb->len);
+
+       desc->ctrl &= ~DESC_EMPTY;
+       ring->curr += n;
 
        /* flush descriptor */
        wmb();
 
-       ring->curr++;
-       if (ring->curr == (ring->dirty + ring->size)) {
-               DBG("%s: tx queue full\n", ag->dev->name);
+       ring_min = 2;
+       if (ring->desc_split)
+           ring_min *= AG71XX_TX_RING_DS_PER_PKT;
+
+       if (ring->curr - ring->dirty >= ring->size - ring_min) {
+               DBG("%s: tx queue full\n", dev->name);
                netif_stop_queue(dev);
        }
 
@@ -707,6 +788,9 @@ static netdev_tx_t ag71xx_hard_start_xmit(struct sk_buff *skb,
 
        return NETDEV_TX_OK;
 
+err_drop_unmap:
+       dma_unmap_single(&dev->dev, dma_addr, skb->len, DMA_TO_DEVICE);
+
 err_drop:
        dev->stats.tx_dropped++;
 
@@ -834,19 +918,25 @@ static int ag71xx_tx_packets(struct ag71xx *ag)
 
                ag71xx_wr(ag, AG71XX_REG_TX_STATUS, TX_STATUS_PS);
 
-               bytes_compl += skb->len;
-               ag->dev->stats.tx_bytes += skb->len;
-               ag->dev->stats.tx_packets++;
+               if (skb) {
+                       dev_kfree_skb_any(skb);
+                       ring->buf[i].skb = NULL;
 
-               dev_kfree_skb_any(skb);
-               ring->buf[i].skb = NULL;
+                       bytes_compl += ring->buf[i].len;
+                       sent++;
+               }
 
                ring->dirty++;
-               sent++;
        }
 
        DBG("%s: %d packets sent out\n", ag->dev->name, sent);
 
+       ag->dev->stats.tx_bytes += bytes_compl;
+       ag->dev->stats.tx_packets += sent;
+
+       if (!sent)
+               return 0;
+
        netdev_completed_queue(ag->dev, sent, bytes_compl);
        if ((ring->curr - ring->dirty) < (ring->size * 3) / 4)
                netif_wake_queue(ag->dev);
@@ -859,6 +949,7 @@ static int ag71xx_rx_packets(struct ag71xx *ag, int limit)
        struct net_device *dev = ag->dev;
        struct ag71xx_ring *ring = &ag->rx_ring;
        int offset = ag71xx_buffer_offset(ag);
+       unsigned int pktlen_mask = ag->desc_pktlen_mask;
        int done = 0;
 
        DBG("%s: rx packets, limit=%d, curr=%u, dirty=%u\n",
@@ -881,13 +972,12 @@ static int ag71xx_rx_packets(struct ag71xx *ag, int limit)
 
                ag71xx_wr(ag, AG71XX_REG_RX_STATUS, RX_STATUS_PR);
 
-               pktlen = ag71xx_desc_pktlen(desc);
+               pktlen = desc->ctrl & pktlen_mask;
                pktlen -= ETH_FCS_LEN;
 
                dma_unmap_single(&dev->dev, ring->buf[i].dma_addr,
-                                AG71XX_RX_BUF_SIZE, DMA_FROM_DEVICE);
+                                ag->rx_buf_size, DMA_FROM_DEVICE);
 
-               dev->last_rx = jiffies;
                dev->stats.rx_packets++;
                dev->stats.rx_bytes += pktlen;
 
@@ -1044,10 +1134,16 @@ static void ag71xx_netpoll(struct net_device *dev)
 
 static int ag71xx_change_mtu(struct net_device *dev, int new_mtu)
 {
-       if (new_mtu < 68 ||
-           new_mtu > AG71XX_TX_MTU_LEN - ETH_HLEN - ETH_FCS_LEN)
+       struct ag71xx *ag = netdev_priv(dev);
+       unsigned int max_frame_len;
+
+       max_frame_len = ag71xx_max_frame_len(new_mtu);
+       if (new_mtu < 68 || max_frame_len > ag->max_frame_len)
                return -EINVAL;
 
+       if (netif_running(dev))
+               return -EBUSY;
+
        dev->mtu = new_mtu;
        return 0;
 }
@@ -1115,6 +1211,9 @@ static int ag71xx_probe(struct platform_device *pdev)
                goto err_out;
        }
 
+       if (!pdata->max_frame_len || !pdata->desc_pktlen_mask)
+               return -EINVAL;
+
        SET_NETDEV_DEV(dev, &pdev->dev);
 
        ag = netdev_priv(dev);
@@ -1160,6 +1259,16 @@ static int ag71xx_probe(struct platform_device *pdev)
        ag->tx_ring.size = AG71XX_TX_RING_SIZE_DEFAULT;
        ag->rx_ring.size = AG71XX_RX_RING_SIZE_DEFAULT;
 
+       ag->max_frame_len = pdata->max_frame_len;
+       ag->desc_pktlen_mask = pdata->desc_pktlen_mask;
+
+#ifdef notyet
+       if (!pdata->is_ar724x && !pdata->is_ar91xx) {
+               ag->tx_ring.desc_split = AG71XX_TX_RING_SPLIT;
+               ag->tx_ring.size *= AG71XX_TX_RING_DS_PER_PKT;
+       }
+#endif
+
        ag->stop_desc = dma_alloc_coherent(NULL,
                sizeof(struct ag71xx_desc), &ag->stop_desc_dma, GFP_KERNEL);
 
@@ -1174,16 +1283,6 @@ static int ag71xx_probe(struct platform_device *pdev)
 
        netif_napi_add(dev, &ag->napi, ag71xx_poll, AG71XX_NAPI_WEIGHT);
 
-       err = register_netdev(dev);
-       if (err) {
-               dev_err(&pdev->dev, "unable to register net device\n");
-               goto err_free_desc;
-       }
-
-       pr_info("%s: Atheros AG71xx at 0x%08lx, irq %d, mode:%s\n",
-               dev->name, dev->base_addr, dev->irq,
-               ag71xx_get_phy_if_mode_name(pdata->phy_if_mode));
-
        ag71xx_dump_regs(ag);
 
        ag71xx_hw_init(ag);
@@ -1192,7 +1291,7 @@ static int ag71xx_probe(struct platform_device *pdev)
 
        err = ag71xx_phy_connect(ag);
        if (err)
-               goto err_unregister_netdev;
+               goto err_free_desc;
 
        err = ag71xx_debugfs_init(ag);
        if (err)
@@ -1200,12 +1299,22 @@ static int ag71xx_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, dev);
 
+       err = register_netdev(dev);
+       if (err) {
+               dev_err(&pdev->dev, "unable to register net device\n");
+               goto err_debugfs_exit;
+       }
+
+       pr_info("%s: Atheros AG71xx at 0x%08lx, irq %d, mode:%s\n",
+               dev->name, dev->base_addr, dev->irq,
+               ag71xx_get_phy_if_mode_name(pdata->phy_if_mode));
+
        return 0;
 
+err_debugfs_exit:
+       ag71xx_debugfs_exit(ag);
 err_phy_disconnect:
        ag71xx_phy_disconnect(ag);
-err_unregister_netdev:
-       unregister_netdev(dev);
 err_free_desc:
        dma_free_coherent(NULL, sizeof(struct ag71xx_desc), ag->stop_desc,
                          ag->stop_desc_dma);