[netdrvr sis190] convert TX path to use PCI DMA API

Also, minor changes:
* mark ->hard_start_xmit ETH_ZLEN test as unlikely()
* use cpu_to_le32() and le32_to_cpu() in TX path
* fix two leak in error path, in ->hard_start_xmit
* don't test netif_queue_stopped() in TX completion path,
  netif_wake_queue() already does that.

diff --git a/drivers/net/sis190.c b/drivers/net/sis190.c
index 3cf5a41500323019e6e16c9452609134e8bdb6e8..ee737ece73b54fb55201d22004c5315091ac2208 100644 (file)
--- a/drivers/net/sis190.c
+++ b/drivers/net/sis190.c
@@ -856,7 +856,14 @@ SiS190_tx_clear(struct sis190_private *tp)
        tp->cur_tx = 0;
        for (i = 0; i < NUM_TX_DESC; i++) {
                if (tp->Tx_skbuff[i] != NULL) {
-                       dev_kfree_skb(tp->Tx_skbuff[i]);
+                       struct sk_buff *skb;
+
+                       skb = tp->Tx_skbuff[i];
+                       pci_unmap_single(tp->pci_dev,
+                               le32_to_cpu(tp->TxDescArray[i].buf_addr),
+                               skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len,
+                               PCI_DMA_TODEVICE);
+                       dev_kfree_skb(skb);
                        tp->Tx_skbuff[i] = NULL;
                        tp->stats.tx_dropped++;
                }
@@ -895,46 +902,58 @@ SiS190_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct sis190_private *tp = dev->priv;
        void *ioaddr = tp->mmio_addr;
        int entry = tp->cur_tx % NUM_TX_DESC;
+       u32 len;
 
-       if (skb->len < ETH_ZLEN) {
+       if (unlikely(skb->len < ETH_ZLEN)) {
                skb = skb_padto(skb, ETH_ZLEN);
                if (skb == NULL)
-                       return 0;
+                       goto drop_tx;
+               len = ETH_ZLEN;
+       } else {
+               len = skb->len;
        }
 
        spin_lock_irq(&tp->lock);
 
-       if ((tp->TxDescArray[entry].status & OWNbit) == 0) {
-#warning Replace virt_to_bus with DMA mapping
+       if ((le32_to_cpu(tp->TxDescArray[entry].status) & OWNbit) == 0) {
+               dma_addr_t mapping;
+
+               mapping = pci_map_single(tp->pci_dev, skb->data, len,
+                                        PCI_DMA_TODEVICE);
+
                tp->Tx_skbuff[entry] = skb;
-               tp->TxDescArray[entry].buf_addr = virt_to_bus(skb->data);
-               tp->TxDescArray[entry].PSize =
-                   ((skb->len > ETH_ZLEN) ? skb->len : ETH_ZLEN);
+               tp->TxDescArray[entry].buf_addr = cpu_to_le32(mapping);
+               tp->TxDescArray[entry].PSize = cpu_to_le32(len);
 
-               if (entry != (NUM_TX_DESC - 1)) {
-                       tp->TxDescArray[entry].buf_Len =
-                           tp->TxDescArray[entry].PSize;
-               } else {
+               if (entry != (NUM_TX_DESC - 1))
+                       tp->TxDescArray[entry].buf_Len = cpu_to_le32(len);
+               else
                        tp->TxDescArray[entry].buf_Len =
-                           tp->TxDescArray[entry].PSize | ENDbit;
-               }
+                               cpu_to_le32(len | ENDbit);
 
                tp->TxDescArray[entry].status |=
-                   (OWNbit | INTbit | DEFbit | CRCbit | PADbit);
+                   cpu_to_le32(OWNbit | INTbit | DEFbit | CRCbit | PADbit);
 
                SiS_W32(TxControl, 0x1a11);     //Start Send
 
                dev->trans_start = jiffies;
 
                tp->cur_tx++;
+       } else {
+               spin_unlock_irq(&tp->lock);
+               goto drop_tx;
        }
 
+       if ((tp->cur_tx - NUM_TX_DESC) == tp->dirty_tx)
+               netif_stop_queue(dev);
+
        spin_unlock_irq(&tp->lock);
 
-       if ((tp->cur_tx - NUM_TX_DESC) == tp->dirty_tx) {
-               netif_stop_queue(dev);
-       }
+       return 0;
 
+drop_tx:
+       tp->stats.tx_dropped++;
+       dev_kfree_skb(skb);
        return 0;
 }
 
@@ -953,10 +972,18 @@ SiS190_tx_interrupt(struct net_device *dev, struct sis190_private *tp,
        tx_left = tp->cur_tx - dirty_tx;
 
        while (tx_left > 0) {
-               if ((tp->TxDescArray[entry].status & OWNbit) == 0) {
-                       dev_kfree_skb_irq(tp->
-                                         Tx_skbuff[dirty_tx % NUM_TX_DESC]);
-                       tp->Tx_skbuff[dirty_tx % NUM_TX_DESC] = NULL;
+               if ((le32_to_cpu(tp->TxDescArray[entry].status) & OWNbit) == 0) {
+                       struct sk_buff *skb;
+
+                       skb = tp->Tx_skbuff[entry];
+
+                       pci_unmap_single(tp->pci_dev,
+                               le32_to_cpu(tp->TxDescArray[entry].buf_addr),
+                               skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len,
+                               PCI_DMA_TODEVICE);
+
+                       dev_kfree_skb_irq(skb);
+                       tp->Tx_skbuff[entry] = NULL;
                        tp->stats.tx_packets++;
                        dirty_tx++;
                        tx_left--;
@@ -966,8 +993,7 @@ SiS190_tx_interrupt(struct net_device *dev, struct sis190_private *tp,
 
        if (tp->dirty_tx != dirty_tx) {
                tp->dirty_tx = dirty_tx;
-               if (netif_queue_stopped(dev))
-                       netif_wake_queue(dev);
+               netif_wake_queue(dev);
        }
 }