[netdrvr r8169] DAC changes:

- Rx and Tx descriptors rings handled on 64 bit;
- enable DAC through use of CPlusCmd register (reserved bits apart, this is
  similar to the 8139cp driver);
- use the higher 32 bits of addresses for the Rx/Tx buffers.

drivers/net/r8169.c

@@ -149,8 +149,10 @@ static int rx_copybreak = 200;
 enum RTL8169_registers {
 	MAC0 = 0,		/* Ethernet hardware address. */
 	MAR0 = 8,		/* Multicast filter. */
-	TxDescStartAddr = 0x20,
-	TxHDescStartAddr = 0x28,
+	TxDescStartAddrLow = 0x20,
+	TxDescStartAddrHigh = 0x24,
+	TxHDescStartAddrLow = 0x28,
+	TxHDescStartAddrHigh = 0x2c,
 	FLASH = 0x30,
 	ERSR = 0x36,
 	ChipCmd = 0x37,
@@ -175,7 +177,8 @@ enum RTL8169_registers {
 	PHYstatus = 0x6C,
 	RxMaxSize = 0xDA,
 	CPlusCmd = 0xE0,
-	RxDescStartAddr = 0xE4,
+	RxDescAddrLow = 0xE4,
+	RxDescAddrHigh = 0xE8,
 	EarlyTxThres = 0xEC,
 	FuncEvent = 0xF0,
 	FuncEventMask = 0xF4,
@@ -227,7 +230,13 @@ enum RTL8169_register_content {
 
 	/*TxConfigBits */
 	TxInterFrameGapShift = 24,
-	TxDMAShift = 8,		/* DMA burst value (0-7) is shift this many bits */
+	TxDMAShift = 8,	/* DMA burst value (0-7) is shift this many bits */
+
+	/* CPlusCmd p.31 */
+	RxVlan		= (1 << 6),
+	RxChkSum	= (1 << 5),
+	PCIDAC		= (1 << 4),
+	PCIMulRW	= (1 << 3),
 
 	/*rtl8169_PHYstatus */
 	TBI_Enable = 0x80,
@@ -286,15 +295,13 @@ enum _DescStatusBit {
 struct TxDesc {
 	u32 status;
 	u32 vlan_tag;
-	u32 buf_addr;
-	u32 buf_Haddr;
+	u64 addr;
 };
 
 struct RxDesc {
 	u32 status;
 	u32 vlan_tag;
-	u32 buf_addr;
-	u32 buf_Haddr;
+	u64 addr;
 };
 
 struct rtl8169_private {
@@ -317,6 +324,7 @@ struct rtl8169_private {
 	struct sk_buff *Tx_skbuff[NUM_TX_DESC];	/* Index of Transmit data buffer */
 	struct timer_list timer;
 	unsigned long phy_link_down_cnt;
+	u16 cp_cmd;
 };
 
 MODULE_AUTHOR("Realtek");
@@ -715,6 +723,20 @@ rtl8169_init_board(struct pci_dev *pdev, struct net_device **dev_out,
 		goto err_out_disable;
 	}
 
+	tp->cp_cmd = PCIMulRW | RxChkSum;
+
+	if ((sizeof(dma_addr_t) > 32) &&
+	    !pci_set_dma_mask(pdev, DMA_64BIT_MASK))
+		tp->cp_cmd |= PCIDAC;
+	else {
+		rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+		if (rc < 0) {
+			printk(KERN_ERR PFX "DMA configuration failed.\n");
+			goto err_out_free_res;
+		}
+	}
+
+
 	// enable PCI bus-mastering
 	pci_set_master(pdev);
 
@@ -1101,17 +1123,21 @@ rtl8169_hw_start(struct net_device *dev)
 	RTL_W32(TxConfig,
 		(TX_DMA_BURST << TxDMAShift) | (InterFrameGap <<
 						TxInterFrameGapShift));
-	RTL_W16(CPlusCmd, RTL_R16(CPlusCmd));
+	tp->cp_cmd |= RTL_R16(CPlusCmd);
+	RTL_W16(CPlusCmd, tp->cp_cmd);
 
 	if (tp->mac_version == RTL_GIGA_MAC_VER_D) {
 		dprintk(KERN_INFO PFX "Set MAC Reg C+CR Offset 0xE0: bit-3 and bit-14 MUST be 1\n");
-		RTL_W16(CPlusCmd, RTL_R16(CPlusCmd) | (1 << 14) | (1 << 3));
+		tp->cp_cmd |= (1 << 14) | PCIMulRW;
+		RTL_W16(CPlusCmd, tp->cp_cmd);
 	}
 
 	tp->cur_rx = 0;
 
-	RTL_W32(TxDescStartAddr, tp->TxPhyAddr);
-	RTL_W32(RxDescStartAddr, tp->RxPhyAddr);
+	RTL_W32(TxDescStartAddrLow, ((u64) tp->TxPhyAddr & DMA_32BIT_MASK));
+	RTL_W32(TxDescStartAddrHigh, ((u64) tp->TxPhyAddr >> 32));
+	RTL_W32(RxDescAddrLow, ((u64) tp->RxPhyAddr & DMA_32BIT_MASK));
+	RTL_W32(RxDescAddrHigh, ((u64) tp->RxPhyAddr >> 32));
 	RTL_W8(Cfg9346, Cfg9346_Lock);
 	udelay(10);
 
@@ -1131,14 +1157,14 @@ rtl8169_hw_start(struct net_device *dev)
 
 static inline void rtl8169_make_unusable_by_asic(struct RxDesc *desc)
 {
-	desc->buf_addr = 0xdeadbeef;
+	desc->addr = 0x0badbadbadbadbad;
 	desc->status &= ~cpu_to_le32(OWNbit | RsvdMask);
 }
 
 static void rtl8169_free_rx_skb(struct pci_dev *pdev, struct sk_buff **sk_buff,
 				struct RxDesc *desc)
 {
-	pci_unmap_single(pdev, le32_to_cpu(desc->buf_addr), RX_BUF_SIZE,
+	pci_unmap_single(pdev, le64_to_cpu(desc->addr), RX_BUF_SIZE,
 			 PCI_DMA_FROMDEVICE);
 	dev_kfree_skb(*sk_buff);
 	*sk_buff = NULL;
@@ -1152,7 +1178,7 @@ static inline void rtl8169_return_to_asic(struct RxDesc *desc)
 
 static inline void rtl8169_give_to_asic(struct RxDesc *desc, dma_addr_t mapping)
 {
-	desc->buf_addr = cpu_to_le32(mapping);
+	desc->addr = cpu_to_le64(mapping);
 	desc->status |= cpu_to_le32(OWNbit + RX_BUF_SIZE);
 }
 
@@ -1250,9 +1276,9 @@ static void rtl8169_unmap_tx_skb(struct pci_dev *pdev, struct sk_buff **sk_buff,
 {
 	u32 len = sk_buff[0]->len;
 
-	pci_unmap_single(pdev, le32_to_cpu(desc->buf_addr),
+	pci_unmap_single(pdev, le64_to_cpu(desc->addr),
 			 len < ETH_ZLEN ? ETH_ZLEN : len, PCI_DMA_TODEVICE);
-	desc->buf_addr = 0x00;
+	desc->addr = 0x00;
 	*sk_buff = NULL;
 }
 
@@ -1324,7 +1350,7 @@ rtl8169_start_xmit(struct sk_buff *skb, struct net_device *dev)
 					 PCI_DMA_TODEVICE);
 
 		tp->Tx_skbuff[entry] = skb;
-		tp->TxDescArray[entry].buf_addr = cpu_to_le32(mapping);
+		tp->TxDescArray[entry].addr = cpu_to_le64(mapping);
 
 		tp->TxDescArray[entry].status = cpu_to_le32(OWNbit | FSbit |
 			LSbit | len | (EORbit * !((entry + 1) % NUM_TX_DESC)));
@@ -1454,7 +1480,7 @@ rtl8169_rx_interrupt(struct net_device *dev, struct rtl8169_private *tp,
 
 
 			pci_dma_sync_single_for_cpu(tp->pci_dev,
-				le32_to_cpu(desc->buf_addr), RX_BUF_SIZE,
+				le64_to_cpu(desc->addr), RX_BUF_SIZE,
 				PCI_DMA_FROMDEVICE);
 
 			if (rtl8169_try_rx_copy(&skb, pkt_size, desc, dev)) {
@@ -1462,7 +1488,7 @@ rtl8169_rx_interrupt(struct net_device *dev, struct rtl8169_private *tp,
 				tp->Rx_skbuff[entry] = NULL;
 			}
 
-			pci_action(tp->pci_dev, le32_to_cpu(desc->buf_addr),
+			pci_action(tp->pci_dev, le64_to_cpu(desc->addr),
 				   RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 
 			skb_put(skb, pkt_size);