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

[Stephen Hemminger <shemminger@xxxxxxxx>]

(Previous patch would apply clean, try this)

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        2004-11-19 10:35:08 -08:00
+++ b/drivers/net/sk98lin/skge.c        2004-11-19 10:35:08 -08:00
@@ -1382,6 +1382,7 @@
  * 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)
 {
@@ -1396,7 +1397,12 @@
        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)) 
@@ -4779,6 +4785,42 @@
 
 #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)
 {
@@ -4827,37 +4869,13 @@
                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++;
 
        if (SkGeBoardInit(dev, pAC))
                goto out_free_netdev;
 
+       SkGeNetDevInit(dev, pdev, pAC);
+ 
        /* Register net device */
        if (register_netdev(dev)) {
                printk(KERN_ERR "SKGE: Could not register device.\n");
@@ -4903,26 +4921,7 @@
                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_ERR "SKGE: Could not register device.\n");