[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>

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index ff6557d..21aeb0c 100644 (file)
--- 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;