ixgbe: refactor tx buffer processing to use skb_dma_map/unmap
Alexander Duyck [Tue, 31 Mar 2009 21:34:23 +0000 (21:34 +0000)]
This patch resolves an issue with map single being used to map a buffer and
then unmap page being used to unmap it.  In addition it handles any error
conditions that may be detected using skb_dma_map.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

index 63c0f19..f36cff5 100644 (file)
@@ -187,15 +187,14 @@ static void ixgbe_unmap_and_free_tx_resource(struct ixgbe_adapter *adapter,
                                              struct ixgbe_tx_buffer
                                              *tx_buffer_info)
 {
-       if (tx_buffer_info->dma) {
-               pci_unmap_page(adapter->pdev, tx_buffer_info->dma,
-                              tx_buffer_info->length, PCI_DMA_TODEVICE);
-               tx_buffer_info->dma = 0;
-       }
+       tx_buffer_info->dma = 0;
        if (tx_buffer_info->skb) {
+               skb_dma_unmap(&adapter->pdev->dev, tx_buffer_info->skb,
+                             DMA_TO_DEVICE);
                dev_kfree_skb_any(tx_buffer_info->skb);
                tx_buffer_info->skb = NULL;
        }
+       tx_buffer_info->time_stamp = 0;
        /* tx_buffer_info must be completely set up in the transmit path */
 }
 
@@ -204,15 +203,11 @@ static inline bool ixgbe_check_tx_hang(struct ixgbe_adapter *adapter,
                                        unsigned int eop)
 {
        struct ixgbe_hw *hw = &adapter->hw;
-       u32 head, tail;
 
        /* Detect a transmit hang in hardware, this serializes the
         * check with the clearing of time_stamp and movement of eop */
-       head = IXGBE_READ_REG(hw, tx_ring->head);
-       tail = IXGBE_READ_REG(hw, tx_ring->tail);
        adapter->detect_tx_hung = false;
-       if ((head != tail) &&
-           tx_ring->tx_buffer_info[eop].time_stamp &&
+       if (tx_ring->tx_buffer_info[eop].time_stamp &&
            time_after(jiffies, tx_ring->tx_buffer_info[eop].time_stamp + HZ) &&
            !(IXGBE_READ_REG(&adapter->hw, IXGBE_TFCS) & IXGBE_TFCS_TXOFF)) {
                /* detected Tx unit hang */
@@ -227,7 +222,8 @@ static inline bool ixgbe_check_tx_hang(struct ixgbe_adapter *adapter,
                        "  time_stamp           <%lx>\n"
                        "  jiffies              <%lx>\n",
                        tx_ring->queue_index,
-                       head, tail,
+                       IXGBE_READ_REG(hw, tx_ring->head),
+                       IXGBE_READ_REG(hw, tx_ring->tail),
                        tx_ring->next_to_use, eop,
                        tx_ring->tx_buffer_info[eop].time_stamp, jiffies);
                return true;
@@ -4164,32 +4160,39 @@ static int ixgbe_tx_map(struct ixgbe_adapter *adapter,
                         struct sk_buff *skb, unsigned int first)
 {
        struct ixgbe_tx_buffer *tx_buffer_info;
-       unsigned int len = skb->len;
+       unsigned int len = skb_headlen(skb);
        unsigned int offset = 0, size, count = 0, i;
        unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
        unsigned int f;
-
-       len -= skb->data_len;
+       dma_addr_t *map;
 
        i = tx_ring->next_to_use;
 
+       if (skb_dma_map(&adapter->pdev->dev, skb, DMA_TO_DEVICE)) {
+               dev_err(&adapter->pdev->dev, "TX DMA map failed\n");
+               return 0;
+       }
+
+       map = skb_shinfo(skb)->dma_maps;
+
        while (len) {
                tx_buffer_info = &tx_ring->tx_buffer_info[i];
                size = min(len, (uint)IXGBE_MAX_DATA_PER_TXD);
 
                tx_buffer_info->length = size;
-               tx_buffer_info->dma = pci_map_single(adapter->pdev,
-                                                    skb->data + offset,
-                                                    size, PCI_DMA_TODEVICE);
+               tx_buffer_info->dma = map[0] + offset;
                tx_buffer_info->time_stamp = jiffies;
                tx_buffer_info->next_to_watch = i;
 
                len -= size;
                offset += size;
                count++;
-               i++;
-               if (i == tx_ring->count)
-                       i = 0;
+
+               if (len) {
+                       i++;
+                       if (i == tx_ring->count)
+                               i = 0;
+               }
        }
 
        for (f = 0; f < nr_frags; f++) {
@@ -4197,33 +4200,27 @@ static int ixgbe_tx_map(struct ixgbe_adapter *adapter,
 
                frag = &skb_shinfo(skb)->frags[f];
                len = frag->size;
-               offset = frag->page_offset;
+               offset = 0;
 
                while (len) {
+                       i++;
+                       if (i == tx_ring->count)
+                               i = 0;
+
                        tx_buffer_info = &tx_ring->tx_buffer_info[i];
                        size = min(len, (uint)IXGBE_MAX_DATA_PER_TXD);
 
                        tx_buffer_info->length = size;
-                       tx_buffer_info->dma = pci_map_page(adapter->pdev,
-                                                          frag->page,
-                                                          offset,
-                                                          size,
-                                                          PCI_DMA_TODEVICE);
+                       tx_buffer_info->dma = map[f + 1] + offset;
                        tx_buffer_info->time_stamp = jiffies;
                        tx_buffer_info->next_to_watch = i;
 
                        len -= size;
                        offset += size;
                        count++;
-                       i++;
-                       if (i == tx_ring->count)
-                               i = 0;
                }
        }
-       if (i == 0)
-               i = tx_ring->count - 1;
-       else
-               i = i - 1;
+
        tx_ring->tx_buffer_info[i].skb = skb;
        tx_ring->tx_buffer_info[first].next_to_watch = i;
 
@@ -4389,13 +4386,19 @@ static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                 (skb->ip_summed == CHECKSUM_PARTIAL))
                tx_flags |= IXGBE_TX_FLAGS_CSUM;
 
-       ixgbe_tx_queue(adapter, tx_ring, tx_flags,
-                      ixgbe_tx_map(adapter, tx_ring, skb, first),
-                      skb->len, hdr_len);
+       count = ixgbe_tx_map(adapter, tx_ring, skb, first);
 
-       netdev->trans_start = jiffies;
+       if (count) {
+               ixgbe_tx_queue(adapter, tx_ring, tx_flags, count, skb->len,
+                              hdr_len);
+               netdev->trans_start = jiffies;
+               ixgbe_maybe_stop_tx(netdev, tx_ring, DESC_NEEDED);
 
-       ixgbe_maybe_stop_tx(netdev, tx_ring, DESC_NEEDED);
+       } else {
+               dev_kfree_skb_any(skb);
+               tx_ring->tx_buffer_info[first].time_stamp = 0;
+               tx_ring->next_to_use = first;
+       }
 
        return NETDEV_TX_OK;
 }