ixgb: refactor tx path to use skb_dma_map/unmap

This code updates ixgb so that it can use the skb_dma_map/unmap functions
to map the buffers.  In addition it also updates the tx hang logic to use
time_stamp instead of dma to determine if it has detected a tx hang.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 31 deletions

diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index e2ef16b2970..4b0ea66d7a4 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -887,19 +887,13 @@ static void
 ixgb_unmap_and_free_tx_resource(struct ixgb_adapter *adapter,
                                 struct ixgb_buffer *buffer_info)
 {
-        struct pci_dev *pdev = adapter->pdev;
-
-        if (buffer_info->dma)
-                pci_unmap_page(pdev, buffer_info->dma, buffer_info->length,
-                               PCI_DMA_TODEVICE);
-
-        /* okay to call kfree_skb here instead of kfree_skb_any because
-         * this is never called in interrupt context */
-        if (buffer_info->skb)
-                dev_kfree_skb(buffer_info->skb);
-
-        buffer_info->skb = NULL;
         buffer_info->dma = 0;
+        if (buffer_info->skb) {
+                skb_dma_unmap(&adapter->pdev->dev, buffer_info->skb,
+                              DMA_TO_DEVICE);
+                dev_kfree_skb_any(buffer_info->skb);
+                buffer_info->skb = NULL;
+        }
         buffer_info->time_stamp = 0;
         /* these fields must always be initialized in tx
          * buffer_info->length = 0;
@@ -1275,17 +1269,23 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
 {
         struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;
         struct ixgb_buffer *buffer_info;
-        int len = skb->len;
+        int len = skb_headlen(skb);
         unsigned int offset = 0, size, count = 0, i;
         unsigned int mss = skb_shinfo(skb)->gso_size;
 
         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) {
                 buffer_info = &tx_ring->buffer_info[i];
                 size = min(len, IXGB_MAX_DATA_PER_TXD);
@@ -1297,7 +1297,7 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
                 buffer_info->length = size;
                 WARN_ON(buffer_info->dma != 0);
                 buffer_info->time_stamp = jiffies;
-                buffer_info->dma =
+                buffer_info->dma = map[0] + offset;
                         pci_map_single(adapter->pdev,
                                 skb->data + offset,
                                 size,
@@ -1307,7 +1307,11 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
                 len -= size;
                 offset += size;
                 count++;
-                if (++i == tx_ring->count) i = 0;
+                if (len) {
+                        i++;
+                        if (i == tx_ring->count)
+                                i = 0;
+                }
         }
 
         for (f = 0; f < nr_frags; f++) {
@@ -1318,6 +1322,10 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
                 offset = 0;
 
                 while (len) {
+                        i++;
+                        if (i == tx_ring->count)
+                                i = 0;
+
                         buffer_info = &tx_ring->buffer_info[i];
                         size = min(len, IXGB_MAX_DATA_PER_TXD);
 
@@ -1329,21 +1337,14 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
 
                         buffer_info->length = size;
                         buffer_info->time_stamp = jiffies;
-                        buffer_info->dma =
-                                pci_map_page(adapter->pdev,
-                                        frag->page,
-                                        frag->page_offset + offset,
-                                        size,
-                                        PCI_DMA_TODEVICE);
+                        buffer_info->dma = map[f + 1] + offset;
                         buffer_info->next_to_watch = 0;
 
                         len -= size;
                         offset += size;
                         count++;
-                        if (++i == tx_ring->count) i = 0;
                 }
         }
-        i = (i == 0) ? tx_ring->count - 1 : i - 1;
         tx_ring->buffer_info[i].skb = skb;
         tx_ring->buffer_info[first].next_to_watch = i;
 
@@ -1445,6 +1446,7 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         unsigned int first;
         unsigned int tx_flags = 0;
         int vlan_id = 0;
+        int count = 0;
         int tso;
 
         if (test_bit(__IXGB_DOWN, &adapter->flags)) {
@@ -1479,13 +1481,19 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         else if (ixgb_tx_csum(adapter, skb))
                 tx_flags |= IXGB_TX_FLAGS_CSUM;
 
-        ixgb_tx_queue(adapter, ixgb_tx_map(adapter, skb, first), vlan_id,
-                        tx_flags);
+        count = ixgb_tx_map(adapter, skb, first);
 
-        netdev->trans_start = jiffies;
+        if (count) {
+                ixgb_tx_queue(adapter, count, vlan_id, tx_flags);
+                netdev->trans_start = jiffies;
+                /* Make sure there is space in the ring for the next send. */
+                ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, DESC_NEEDED);
 
-        /* Make sure there is space in the ring for the next send. */
-        ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, DESC_NEEDED);
+        } else {
+                dev_kfree_skb_any(skb);
+                adapter->tx_ring.buffer_info[first].time_stamp = 0;
+                adapter->tx_ring.next_to_use = first;
+        }
 
         return NETDEV_TX_OK;
 }
@@ -1818,7 +1826,7 @@ ixgb_clean_tx_irq(struct ixgb_adapter *adapter)
                 /* detect a transmit hang in hardware, this serializes the
                  * check with the clearing of time_stamp and movement of i */
                 adapter->detect_tx_hung = false;
-                if (tx_ring->buffer_info[eop].dma &&
+                if (tx_ring->buffer_info[eop].time_stamp &&
                    time_after(jiffies, tx_ring->buffer_info[eop].time_stamp + HZ)
                    && !(IXGB_READ_REG(&adapter->hw, STATUS) &
                         IXGB_STATUS_TXOFF)) {