[PATCH] sky2: transmit complete routine optimization

Hand optimize transmit completion routine.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 16 insertions, 19 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index ff6557dd079c..21aeb0c91fa6 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1227,6 +1227,8 @@ out_unlock:
 static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
 {
         struct net_device *dev = sky2->netdev;
+        struct pci_dev *pdev = sky2->hw->pdev;
+        u16 nxt, put;
         unsigned i;
 
         BUG_ON(done >= TX_RING_SIZE);
@@ -1235,39 +1237,34 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
                 printk(KERN_DEBUG "%s: tx done, up to %u\n",
                        dev->name, done);
 
-        spin_lock(&sky2->tx_lock);
+        for (put = sky2->tx_cons; put != done; put = nxt) {
+                struct tx_ring_info *re = sky2->tx_ring + put;
+                struct sk_buff *skb = re->skb;
 
-        while (sky2->tx_cons != done) {
-                struct tx_ring_info *re = sky2->tx_ring + sky2->tx_cons;
-                struct sk_buff *skb;
+                nxt = re->idx;
+                BUG_ON(nxt >= TX_RING_SIZE);
 
                 /* Check for partial status */
-                if (tx_dist(sky2->tx_cons, done)
-                    < tx_dist(sky2->tx_cons, re->idx))
-                        goto out;
+                if (tx_dist(put, done) < tx_dist(put, nxt))
+                        break;
 
                 skb = re->skb;
-                pci_unmap_single(sky2->hw->pdev,
-                                 pci_unmap_addr(re, mapaddr),
+                pci_unmap_single(pdev, pci_unmap_addr(re, mapaddr),
                                  skb_headlen(skb), PCI_DMA_TODEVICE);
 
                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
                         struct tx_ring_info *fre;
-                        fre =
-                            sky2->tx_ring + (sky2->tx_cons + i +
-                                             1) % TX_RING_SIZE;
-                        pci_unmap_page(sky2->hw->pdev,
-                                       pci_unmap_addr(fre, mapaddr),
-                                       skb_shinfo(skb)->frags[i].size,
+                        fre = sky2->tx_ring + (put + i + 1) % TX_RING_SIZE;
+                        pci_unmap_page(pdev, pci_unmap_addr(fre, mapaddr),
+                                       skb_shinfo(skb)->frags[i].size,
                                        PCI_DMA_TODEVICE);
                 }
 
                 dev_kfree_skb_any(skb);
-
-                sky2->tx_cons = re->idx;
         }
-out:
 
+        spin_lock(&sky2->tx_lock);
+        sky2->tx_cons = put;
         if (netif_queue_stopped(dev) && tx_avail(sky2) > MAX_SKB_TX_LE)
                 netif_wake_queue(dev);
         spin_unlock(&sky2->tx_lock);
@@ -1742,7 +1739,7 @@ static int sky2_poll(struct net_device *dev0, int *budget)
         sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
         hwidx = sky2_read16(hw, STAT_PUT_IDX);
         BUG_ON(hwidx >= STATUS_RING_SIZE);
-        rmb();
+        rmb();
 
         while (hwidx != hw->st_idx) {
                 struct sky2_status_le *le  = hw->st_le + hw->st_idx;