8139cp: ring_info removal for the transmit path

As long as the descriptor fits on a single cacheline, the change
should be almost free.

Now ring_info is not used at all. Remove it.
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>

drivers/net/8139cp.c

@@ -314,11 +314,6 @@ struct cp_desc {
 	u64		addr;
 };
 
-struct ring_info {
-	struct sk_buff		*skb;
-	u32			len;
-};
-
 struct cp_dma_stats {
 	u64			tx_ok;
 	u64			rx_ok;
@@ -360,7 +355,7 @@ struct cp_private {
 	unsigned		tx_head		____cacheline_aligned;
 	unsigned		tx_tail;
 	struct cp_desc		*tx_ring;
-	struct ring_info	tx_skb[CP_TX_RING_SIZE];
+	struct sk_buff		*tx_skb[CP_TX_RING_SIZE];
 
 	unsigned		rx_buf_sz;
 	unsigned		wol_enabled : 1; /* Is Wake-on-LAN enabled? */
@@ -721,11 +716,12 @@ static void cp_tx (struct cp_private *cp)
 		if (status & DescOwn)
 			break;
 
-		skb = cp->tx_skb[tx_tail].skb;
+		skb = cp->tx_skb[tx_tail];
 		BUG_ON(!skb);
 
 		pci_unmap_single(cp->pdev, le64_to_cpu(txd->addr),
-				 cp->tx_skb[tx_tail].len, PCI_DMA_TODEVICE);
+				 le32_to_cpu(txd->opts1) & 0xffff,
+				 PCI_DMA_TODEVICE);
 
 		if (status & LastFrag) {
 			if (status & (TxError | TxFIFOUnder)) {
@@ -752,7 +748,7 @@ static void cp_tx (struct cp_private *cp)
 			dev_kfree_skb_irq(skb);
 		}
 
-		cp->tx_skb[tx_tail].skb = NULL;
+		cp->tx_skb[tx_tail] = NULL;
 
 		tx_tail = NEXT_TX(tx_tail);
 	}
@@ -822,8 +818,7 @@ static int cp_start_xmit (struct sk_buff *skb, struct net_device *dev)
 		txd->opts1 = cpu_to_le32(flags);
 		wmb();
 
-		cp->tx_skb[entry].skb = skb;
-		cp->tx_skb[entry].len = len;
+		cp->tx_skb[entry] = skb;
 		entry = NEXT_TX(entry);
 	} else {
 		struct cp_desc *txd;
@@ -839,8 +834,7 @@ static int cp_start_xmit (struct sk_buff *skb, struct net_device *dev)
 		first_len = skb_headlen(skb);
 		first_mapping = pci_map_single(cp->pdev, skb->data,
 					       first_len, PCI_DMA_TODEVICE);
-		cp->tx_skb[entry].skb = skb;
-		cp->tx_skb[entry].len = first_len;
+		cp->tx_skb[entry] = skb;
 		entry = NEXT_TX(entry);
 
 		for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
@@ -881,8 +875,7 @@ static int cp_start_xmit (struct sk_buff *skb, struct net_device *dev)
 			txd->opts1 = cpu_to_le32(ctrl);
 			wmb();
 
-			cp->tx_skb[entry].skb = skb;
-			cp->tx_skb[entry].len = len;
+			cp->tx_skb[entry] = skb;
 			entry = NEXT_TX(entry);
 		}
 
@@ -1159,12 +1152,13 @@ static void cp_clean_rings (struct cp_private *cp)
 	}
 
 	for (i = 0; i < CP_TX_RING_SIZE; i++) {
-		if (cp->tx_skb[i].skb) {
-			struct sk_buff *skb = cp->tx_skb[i].skb;
+		if (cp->tx_skb[i]) {
+			struct sk_buff *skb = cp->tx_skb[i];
 
 			desc = cp->tx_ring + i;
 			pci_unmap_single(cp->pdev, le64_to_cpu(desc->addr),
-				 	 cp->tx_skb[i].len, PCI_DMA_TODEVICE);
+					 le32_to_cpu(desc->opts1) & 0xffff,
+					 PCI_DMA_TODEVICE);
 			if (le32_to_cpu(desc->opts1) & LastFrag)
 				dev_kfree_skb(skb);
 			cp->net_stats.tx_dropped++;
@@ -1175,7 +1169,7 @@ static void cp_clean_rings (struct cp_private *cp)
 	memset(cp->tx_ring, 0, sizeof(struct cp_desc) * CP_TX_RING_SIZE);
 
 	memset(cp->rx_skb, 0, sizeof(struct sk_buff *) * CP_RX_RING_SIZE);
-	memset(&cp->tx_skb, 0, sizeof(struct ring_info) * CP_TX_RING_SIZE);
+	memset(cp->tx_skb, 0, sizeof(struct sk_buff *) * CP_TX_RING_SIZE);
 }
 
 static void cp_free_rings (struct cp_private *cp)