ixgbe: refactor tx buffer processing to use skb_dma_map/unmap

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>

1 files changed, 41 insertions, 38 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 63c0f19c11a3..f36cff52d48f 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -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;
 }