*                        of nv_remove
  *      0.42: 06 Aug 2005: Fix lack of link speed initialization
  *                        in the second (and later) nv_open call
+ *      0.43: 10 Aug 2005: Add support for tx checksum.
  *
  * Known bugs:
  * We suspect that on some hardware no TX done interrupts are generated.
  * DEV_NEED_TIMERIRQ will not harm you on sane hardware, only generating a few
  * superfluous timer interrupts from the nic.
  */
-#define FORCEDETH_VERSION              "0.41"
+#define FORCEDETH_VERSION              "0.43"
 #define DRV_NAME                       "forcedeth"
 
 #include <linux/module.h>
 #define DEV_NEED_LINKTIMER     0x0002  /* poll link settings. Relies on the timer irq */
 #define DEV_HAS_LARGEDESC      0x0004  /* device supports jumbo frames and needs packet format 2 */
 #define DEV_HAS_HIGH_DMA        0x0008  /* device supports 64bit dma */
+#define DEV_HAS_CHECKSUM        0x0010  /* device supports tx and rx checksum offloads */
 
 enum {
        NvRegIrqStatus = 0x000,
 #define NVREG_TXRXCTL_IDLE     0x0008
 #define NVREG_TXRXCTL_RESET    0x0010
 #define NVREG_TXRXCTL_RXCHECK  0x0400
+#define NVREG_TXRXCTL_DESC_1   0
+#define NVREG_TXRXCTL_DESC_2   0x02100
+#define NVREG_TXRXCTL_DESC_3   0x02200
        NvRegMIIStatus = 0x180,
 #define NVREG_MIISTAT_ERROR            0x0001
 #define NVREG_MIISTAT_LINKCHANGE       0x0008
 /* error and valid are the same for both */
 #define NV_TX2_ERROR           (1<<30)
 #define NV_TX2_VALID           (1<<31)
+#define NV_TX2_CHECKSUM_L3     (1<<27)
+#define NV_TX2_CHECKSUM_L4     (1<<26)
 
 #define NV_RX_DESCRIPTORVALID  (1<<16)
 #define NV_RX_MISSEDFRAME      (1<<17)
 
 /* 
  * desc_ver values:
- * This field has two purposes:
- * - Newer nics uses a different ring layout. The layout is selected by
- *   comparing np->desc_ver with DESC_VER_xy.
- * - It contains bits that are forced on when writing to NvRegTxRxControl.
+ * The nic supports three different descriptor types:
+ * - DESC_VER_1: Original
+ * - DESC_VER_2: support for jumbo frames.
+ * - DESC_VER_3: 64-bit format.
  */
-#define DESC_VER_1     0x0
-#define DESC_VER_2     (0x02100|NVREG_TXRXCTL_RXCHECK)
-#define DESC_VER_3      (0x02200|NVREG_TXRXCTL_RXCHECK)
+#define DESC_VER_1     1
+#define DESC_VER_2     2
+#define DESC_VER_3     3
 
 /* PHY defines */
 #define PHY_OUI_MARVELL        0x5043
        u32 orig_mac[2];
        u32 irqmask;
        u32 desc_ver;
+       u32 txrxctl_bits;
 
        void __iomem *base;
 
        u8 __iomem *base = get_hwbase(dev);
 
        dprintk(KERN_DEBUG "%s: nv_txrx_reset\n", dev->name);
-       writel(NVREG_TXRXCTL_BIT2 | NVREG_TXRXCTL_RESET | np->desc_ver, base + NvRegTxRxControl);
+       writel(NVREG_TXRXCTL_BIT2 | NVREG_TXRXCTL_RESET | np->txrxctl_bits, base + NvRegTxRxControl);
        pci_push(base);
        udelay(NV_TXRX_RESET_DELAY);
-       writel(NVREG_TXRXCTL_BIT2 | np->desc_ver, base + NvRegTxRxControl);
+       writel(NVREG_TXRXCTL_BIT2 | np->txrxctl_bits, base + NvRegTxRxControl);
        pci_push(base);
 }
 
 {
        struct fe_priv *np = get_nvpriv(dev);
        int nr = np->next_tx % TX_RING;
+       u32 tx_checksum = (skb->ip_summed == CHECKSUM_HW ? (NV_TX2_CHECKSUM_L3|NV_TX2_CHECKSUM_L4) : 0);
 
        np->tx_skbuff[nr] = skb;
        np->tx_dma[nr] = pci_map_single(np->pci_dev, skb->data,skb->len,
        spin_lock_irq(&np->lock);
        wmb();
        if (np->desc_ver == DESC_VER_1 || np->desc_ver == DESC_VER_2)
-               np->tx_ring.orig[nr].FlagLen = cpu_to_le32( (skb->len-1) | np->tx_flags );
+               np->tx_ring.orig[nr].FlagLen = cpu_to_le32( (skb->len-1) | np->tx_flags | tx_checksum);
        else
-               np->tx_ring.ex[nr].FlagLen = cpu_to_le32( (skb->len-1) | np->tx_flags );
-       dprintk(KERN_DEBUG "%s: nv_start_xmit: packet packet %d queued for transmission.\n",
+               np->tx_ring.ex[nr].FlagLen = cpu_to_le32( (skb->len-1) | np->tx_flags | tx_checksum);
+       dprintk(KERN_DEBUG "%s: nv_start_xmit: packet packet %d queued for transmission\n",
                                dev->name, np->next_tx);
        {
                int j;
        if (np->next_tx - np->nic_tx >= TX_LIMIT_STOP)
                netif_stop_queue(dev);
        spin_unlock_irq(&np->lock);
-       writel(NVREG_TXRXCTL_KICK|np->desc_ver, get_hwbase(dev) + NvRegTxRxControl);
+       writel(NVREG_TXRXCTL_KICK|np->txrxctl_bits, get_hwbase(dev) + NvRegTxRxControl);
        pci_push(get_hwbase(dev));
        return 0;
 }
                writel( ((RX_RING-1) << NVREG_RINGSZ_RXSHIFT) + ((TX_RING-1) << NVREG_RINGSZ_TXSHIFT),
                        base + NvRegRingSizes);
                pci_push(base);
-               writel(NVREG_TXRXCTL_KICK|np->desc_ver, get_hwbase(dev) + NvRegTxRxControl);
+               writel(NVREG_TXRXCTL_KICK|np->txrxctl_bits, get_hwbase(dev) + NvRegTxRxControl);
                pci_push(base);
 
                /* restart rx engine */
        /* 5) continue setup */
        writel(np->linkspeed, base + NvRegLinkSpeed);
        writel(NVREG_UNKSETUP3_VAL1, base + NvRegUnknownSetupReg3);
-       writel(np->desc_ver, base + NvRegTxRxControl);
+       writel(np->txrxctl_bits, base + NvRegTxRxControl);
        pci_push(base);
-       writel(NVREG_TXRXCTL_BIT1|np->desc_ver, base + NvRegTxRxControl);
+       writel(NVREG_TXRXCTL_BIT1|np->txrxctl_bits, base + NvRegTxRxControl);
        reg_delay(dev, NvRegUnknownSetupReg5, NVREG_UNKSETUP5_BIT31, NVREG_UNKSETUP5_BIT31,
                        NV_SETUP5_DELAY, NV_SETUP5_DELAYMAX,
                        KERN_INFO "open: SetupReg5, Bit 31 remained off\n");
                        printk(KERN_INFO "forcedeth: 64-bit DMA failed, using 32-bit addressing for device %s.\n",
                                        pci_name(pci_dev));
                }
+               np->txrxctl_bits = NVREG_TXRXCTL_DESC_3;
        } else if (id->driver_data & DEV_HAS_LARGEDESC) {
                /* packet format 2: supports jumbo frames */
                np->desc_ver = DESC_VER_2;
+               np->txrxctl_bits = NVREG_TXRXCTL_DESC_2;
        } else {
                /* original packet format */
                np->desc_ver = DESC_VER_1;
+               np->txrxctl_bits = NVREG_TXRXCTL_DESC_1;
        }
 
        np->pkt_limit = NV_PKTLIMIT_1;
        if (id->driver_data & DEV_HAS_LARGEDESC)
                np->pkt_limit = NV_PKTLIMIT_2;
 
+       if (id->driver_data & DEV_HAS_CHECKSUM) {
+               np->txrxctl_bits |= NVREG_TXRXCTL_RXCHECK;
+               dev->features |= NETIF_F_HW_CSUM;
+       }
+
        err = -ENOMEM;
        np->base = ioremap(addr, NV_PCI_REGSZ);
        if (!np->base)
        },
        {       /* nForce3 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_4),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM,
        },
        {       /* nForce3 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_5),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM,
        },
        {       /* nForce3 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_6),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM,
        },
        {       /* nForce3 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_7),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM,
        },
        {       /* CK804 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_8),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {       /* CK804 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_9),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {       /* MCP04 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_10),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {       /* MCP04 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_11),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {       /* MCP51 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_12),
        },
        {       /* MCP55 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_14),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {       /* MCP55 Ethernet Controller */
                PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NVENET_15),
-               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_HIGH_DMA,
+               .driver_data = DEV_NEED_TIMERIRQ|DEV_NEED_LINKTIMER|DEV_HAS_LARGEDESC|DEV_HAS_CHECKSUM|DEV_HAS_HIGH_DMA,
        },
        {0,},
 };