igb: cleanup tx dma so map & unmap use matching calls
Alexander Duyck [Fri, 20 Mar 2009 00:17:43 +0000 (00:17 +0000)]
The igb driver was using map_single to map the skbs and then unmap_page to
unmap them.  This update changes that so instead uses skb_dma_map and
skb_dma_unmap.

In addition the next_to_watch member of the buffer_info struct was being
set uneccesarily.  I removed the spots where it was set without being needed.

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>

drivers/net/igb/igb_main.c

index d6dda16..ca84216 100644 (file)
@@ -2257,19 +2257,14 @@ static void igb_free_all_tx_resources(struct igb_adapter *adapter)
 static void igb_unmap_and_free_tx_resource(struct igb_adapter *adapter,
                                           struct igb_buffer *buffer_info)
 {
-       if (buffer_info->dma) {
-               pci_unmap_page(adapter->pdev,
-                               buffer_info->dma,
-                               buffer_info->length,
-                               PCI_DMA_TODEVICE);
-               buffer_info->dma = 0;
-       }
+       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;
-       buffer_info->next_to_watch = 0;
        /* buffer_info must be completely set up in the transmit path */
 }
 
@@ -3078,25 +3073,33 @@ static inline int igb_tx_map_adv(struct igb_adapter *adapter,
        unsigned int len = skb_headlen(skb);
        unsigned int count = 0, i;
        unsigned int f;
+       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;
+
        buffer_info = &tx_ring->buffer_info[i];
        BUG_ON(len >= IGB_MAX_DATA_PER_TXD);
        buffer_info->length = len;
        /* set time_stamp *before* dma to help avoid a possible race */
        buffer_info->time_stamp = jiffies;
        buffer_info->next_to_watch = i;
-       buffer_info->dma = pci_map_single(adapter->pdev, skb->data, len,
-                                         PCI_DMA_TODEVICE);
+       buffer_info->dma = map[count];
        count++;
-       i++;
-       if (i == tx_ring->count)
-               i = 0;
 
        for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
                struct skb_frag_struct *frag;
 
+               i++;
+               if (i == tx_ring->count)
+                       i = 0;
+
                frag = &skb_shinfo(skb)->frags[f];
                len = frag->size;
 
@@ -3105,19 +3108,10 @@ static inline int igb_tx_map_adv(struct igb_adapter *adapter,
                buffer_info->length = len;
                buffer_info->time_stamp = jiffies;
                buffer_info->next_to_watch = i;
-               buffer_info->dma = pci_map_page(adapter->pdev,
-                                               frag->page,
-                                               frag->page_offset,
-                                               len,
-                                               PCI_DMA_TODEVICE);
-
+               buffer_info->dma = map[count];
                count++;
-               i++;
-               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;
 
@@ -3230,6 +3224,7 @@ static int igb_xmit_frame_ring_adv(struct sk_buff *skb,
        unsigned int first;
        unsigned int tx_flags = 0;
        u8 hdr_len = 0;
+       int count = 0;
        int tso = 0;
        union skb_shared_tx *shtx;
 
@@ -3291,14 +3286,23 @@ static int igb_xmit_frame_ring_adv(struct sk_buff *skb,
                 (skb->ip_summed == CHECKSUM_PARTIAL))
                tx_flags |= IGB_TX_FLAGS_CSUM;
 
-       igb_tx_queue_adv(adapter, tx_ring, tx_flags,
-                        igb_tx_map_adv(adapter, tx_ring, skb, first),
-                        skb->len, hdr_len);
-
-       netdev->trans_start = jiffies;
-
-       /* Make sure there is space in the ring for the next send. */
-       igb_maybe_stop_tx(netdev, tx_ring, MAX_SKB_FRAGS + 4);
+       /*
+        * count reflects descriptors mapped, if 0 then mapping error
+        * has occured and we need to rewind the descriptor queue
+        */
+       count = igb_tx_map_adv(adapter, tx_ring, skb, first);
+
+       if (count) {
+               igb_tx_queue_adv(adapter, tx_ring, tx_flags, count,
+                                skb->len, hdr_len);
+               netdev->trans_start = jiffies;
+               /* Make sure there is space in the ring for the next send. */
+               igb_maybe_stop_tx(netdev, tx_ring, MAX_SKB_FRAGS + 4);
+       } else {
+               dev_kfree_skb_any(skb);
+               tx_ring->buffer_info[first].time_stamp = 0;
+               tx_ring->next_to_use = first;
+       }
 
        return NETDEV_TX_OK;
 }