[PATCH] (18/25) sk98: lockless transmit

[Stephen Hemminger <shemminger@xxxxxxxx>]

Sk transmit path has it's own locking so doesn't need locking in
device queueing layer. Move net device initiailzation that was done 
twice (once for each port), to a common place.

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx>

diff -Nru a/drivers/net/sk98lin/skge.c b/drivers/net/sk98lin/skge.c
--- a/drivers/net/sk98lin/skge.c        2004-11-15 14:00:29 -08:00
+++ b/drivers/net/sk98lin/skge.c        2004-11-15 14:00:29 -08:00
@@ -1349,6 +1349,7 @@
  * Returns:
  *     0 (NETDEV_TX_OK)        if everything is ok
  *     1 (NETDEV_TX_BUSY)      if ring is full
+ *     -1(NETDEV_TX_LOCKED)    lock collision
  */
 int SkGeXmit(struct sk_buff *skb, struct net_device *dev)
 {
@@ -1363,7 +1364,12 @@
        else
                pTxPort = &pAC->TxPort[pAC->ActivePort][TX_PRIO_LOW];
  
-       spin_lock_irqsave(&pTxPort->TxDesRingLock, flags);
+       local_irq_save(flags); 
+       if (!spin_trylock(&pTxPort->TxDesRingLock)) {
+               /* Collision - tell upper layer to requeue */ 
+               local_irq_restore(flags); 
+               return NETDEV_TX_LOCKED; 
+       } 
 
        if ((!skb_shinfo(skb)->nr_frags) ||
            (pAC->GIni.GIChipId == CHIP_ID_GENESIS)) 
@@ -4746,6 +4752,42 @@
 
 #endif
 
+static void __devinit SkGeNetDevInit(struct net_device *dev, 
+                                    struct pci_dev *pdev, 
+                                    const SK_AC *pAC)
+{
+       SET_MODULE_OWNER(dev);
+       SET_NETDEV_DEV(dev, &pdev->dev);
+       SET_ETHTOOL_OPS(dev, &SkGeEthtoolOps);
+
+       dev->open =             SkGeOpen;
+       dev->stop =             SkGeClose;
+       dev->hard_start_xmit =  SkGeXmit;
+       dev->get_stats =        SkGeStats;
+       dev->set_multicast_list = SkGeSetRxMode;
+       dev->set_mac_address =  SkGeSetMacAddr;
+       dev->do_ioctl =         SkGeIoctl;
+       dev->change_mtu =       SkGeChangeMtu;
+#ifdef CONFIG_NET_POLL_CONTROLLER
+       dev->poll_controller =  SkGePollController;
+#endif
+       dev->flags &=           ~IFF_RUNNING;
+       dev->features |= NETIF_F_LLTX;
+
+       if (pdev->dma_mask == DMA_64BIT_MASK)
+               dev->features |= NETIF_F_HIGHDMA;
+
+       if (pAC->GIni.GIChipId != CHIP_ID_GENESIS) {
+#ifdef SK_ZEROCOPY
+               dev->features |= NETIF_F_SG;
+#endif
+#ifdef USE_SK_TX_CHECKSUM
+               dev->features |= NETIF_F_IP_CSUM;
+#endif
+       }
+}
+
+
 static int __devinit skge_probe_one(struct pci_dev *pdev,
                const struct pci_device_id *ent)
 {
@@ -4792,38 +4834,14 @@
        if (error) 
                goto out_free_netdev;
 
-       SET_MODULE_OWNER(dev);
-       dev->open =             &SkGeOpen;
-       dev->stop =             &SkGeClose;
-       dev->hard_start_xmit =  &SkGeXmit;
-       dev->get_stats =        &SkGeStats;
-       dev->set_multicast_list = &SkGeSetRxMode;
-       dev->set_mac_address =  &SkGeSetMacAddr;
-       dev->do_ioctl =         &SkGeIoctl;
-       dev->change_mtu =       &SkGeChangeMtu;
-#ifdef CONFIG_NET_POLL_CONTROLLER
-       dev->poll_controller =  &SkGePollController;
-#endif
-       dev->flags &=           ~IFF_RUNNING;
-       SET_NETDEV_DEV(dev, &pdev->dev);
-       SET_ETHTOOL_OPS(dev, &SkGeEthtoolOps);
-
-#ifdef SK_ZEROCOPY
-#ifdef USE_SK_TX_CHECKSUM
-       if (pAC->ChipsetType) {
-               /* Use only if yukon hardware */
-               /* SK and ZEROCOPY - fly baby... */
-               dev->features |= NETIF_F_SG | NETIF_F_IP_CSUM;
-       }
-#endif
-#endif
-
        pAC->Index = boards_found++;
 
        error = SkGeBoardInit(dev, pAC);
        if (error)
                goto out_free_netdev;
 
+       SkGeNetDevInit(dev, pdev, pAC);
+
        /* Register net device */
        strcpy(dev->name, "eth%d");
        error = register_netdev(dev);
@@ -4866,26 +4884,7 @@
                pNet->NetNr   = 1;
                pNet->pAC     = pAC;
 
-               dev->open               = &SkGeOpen;
-               dev->stop               = &SkGeClose;
-               dev->hard_start_xmit    = &SkGeXmit;
-               dev->get_stats          = &SkGeStats;
-               dev->set_multicast_list = &SkGeSetRxMode;
-               dev->set_mac_address    = &SkGeSetMacAddr;
-               dev->do_ioctl           = &SkGeIoctl;
-               dev->change_mtu         = &SkGeChangeMtu;
-               dev->flags             &= ~IFF_RUNNING;
-               SET_NETDEV_DEV(dev, &pdev->dev);
-               SET_ETHTOOL_OPS(dev, &SkGeEthtoolOps);
-
-#ifdef SK_ZEROCOPY
-#ifdef USE_SK_TX_CHECKSUM
-               if (pAC->ChipsetType) {
-                       /* SG and ZEROCOPY - fly baby... */
-                       dev->features |= NETIF_F_SG | NETIF_F_IP_CSUM;
-               }
-#endif
-#endif
+               SkGeNetDevInit(dev, pdev, pAC);
 
                if (register_netdev(dev)) {
                        printk(KERN_WARNING "sk98lin: could not register device 
for second port.\n");