ipg: remove some internal comments

[safe/jmp/linux-2.6] / drivers / net / ipg.c

/*
 * ipg.c: Device Driver for the IP1000 Gigabit Ethernet Adapter
 *
 * Copyright (C) 2003, 2007  IC Plus Corp
 *
 * Original Author:
 *
 *   Craig Rich
 *   Sundance Technology, Inc.
 *   www.sundanceti.com
 *   craig_rich@sundanceti.com
 *
 * Current Maintainer:
 *
 *   Sorbica Shieh.
 *   http://www.icplus.com.tw
 *   sorbica@icplus.com.tw
 *
 *   Jesse Huang
 *   http://www.icplus.com.tw
 *   jesse@icplus.com.tw
 */
#include <linux/crc32.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/mutex.h>

#include <asm/div64.h>

#define IPG_RX_RING_BYTES       (sizeof(struct ipg_rx) * IPG_RFDLIST_LENGTH)
#define IPG_TX_RING_BYTES       (sizeof(struct ipg_tx) * IPG_TFDLIST_LENGTH)
#define IPG_RESET_MASK \
        (IPG_AC_GLOBAL_RESET | IPG_AC_RX_RESET | IPG_AC_TX_RESET | \
         IPG_AC_DMA | IPG_AC_FIFO | IPG_AC_NETWORK | IPG_AC_HOST | \
         IPG_AC_AUTO_INIT)

#define ipg_w32(val32,reg)      iowrite32((val32), ioaddr + (reg))
#define ipg_w16(val16,reg)      iowrite16((val16), ioaddr + (reg))
#define ipg_w8(val8,reg)        iowrite8((val8), ioaddr + (reg))

#define ipg_r32(reg)            ioread32(ioaddr + (reg))
#define ipg_r16(reg)            ioread16(ioaddr + (reg))
#define ipg_r8(reg)             ioread8(ioaddr + (reg))

#define JUMBO_FRAME_4k_ONLY
enum {
        netdev_io_size = 128
};

#include "ipg.h"
#define DRV_NAME        "ipg"

MODULE_AUTHOR("IC Plus Corp. 2003");
MODULE_DESCRIPTION("IC Plus IP1000 Gigabit Ethernet Adapter Linux Driver");
MODULE_LICENSE("GPL");

//variable record -- index by leading revision/length
//Revision/Length(=N*4), Address1, Data1, Address2, Data2,...,AddressN,DataN
static unsigned short DefaultPhyParam[] = {
        // 11/12/03 IP1000A v1-3 rev=0x40
        /*--------------------------------------------------------------------------
        (0x4000|(15*4)), 31, 0x0001, 27, 0x01e0, 31, 0x0002, 22, 0x85bd, 24, 0xfff2,
                                 27, 0x0c10, 28, 0x0c10, 29, 0x2c10, 31, 0x0003, 23, 0x92f6,
                                 31, 0x0000, 23, 0x003d, 30, 0x00de, 20, 0x20e7,  9, 0x0700,
          --------------------------------------------------------------------------*/
        // 12/17/03 IP1000A v1-4 rev=0x40
        (0x4000 | (07 * 4)), 31, 0x0001, 27, 0x01e0, 31, 0x0002, 27, 0xeb8e, 31,
            0x0000,
        30, 0x005e, 9, 0x0700,
        // 01/09/04 IP1000A v1-5 rev=0x41
        (0x4100 | (07 * 4)), 31, 0x0001, 27, 0x01e0, 31, 0x0002, 27, 0xeb8e, 31,
            0x0000,
        30, 0x005e, 9, 0x0700,
        0x0000
};

static const char *ipg_brand_name[] = {
        "IC PLUS IP1000 1000/100/10 based NIC",
        "Sundance Technology ST2021 based NIC",
        "Tamarack Microelectronics TC9020/9021 based NIC",
        "Tamarack Microelectronics TC9020/9021 based NIC",
        "D-Link NIC",
        "D-Link NIC IP1000A"
};

static struct pci_device_id ipg_pci_tbl[] __devinitdata = {
        { PCI_VDEVICE(SUNDANCE, 0x1023), 0 },
        { PCI_VDEVICE(SUNDANCE, 0x2021), 1 },
        { PCI_VDEVICE(SUNDANCE, 0x1021), 2 },
        { PCI_VDEVICE(DLINK,    0x9021), 3 },
        { PCI_VDEVICE(DLINK,    0x4000), 4 },
        { PCI_VDEVICE(DLINK,    0x4020), 5 },
        { 0, }
};

MODULE_DEVICE_TABLE(pci, ipg_pci_tbl);

static inline void __iomem *ipg_ioaddr(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        return sp->ioaddr;
}

#ifdef IPG_DEBUG
static void ipg_dump_rfdlist(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;
        u32 offset;

        IPG_DEBUG_MSG("_dump_rfdlist\n");

        printk(KERN_INFO "rx_current = %2.2x\n", sp->rx_current);
        printk(KERN_INFO "rx_dirty   = %2.2x\n", sp->rx_dirty);
        printk(KERN_INFO "RFDList start address = %16.16lx\n",
               (unsigned long) sp->rxd_map);
        printk(KERN_INFO "RFDListPtr register   = %8.8x%8.8x\n",
               ipg_r32(IPG_RFDLISTPTR1), ipg_r32(IPG_RFDLISTPTR0));

        for (i = 0; i < IPG_RFDLIST_LENGTH; i++) {
                offset = (u32) &sp->rxd[i].next_desc - (u32) sp->rxd;
                printk(KERN_INFO "%2.2x %4.4x RFDNextPtr = %16.16lx\n", i,
                       offset, (unsigned long) sp->rxd[i].next_desc);
                offset = (u32) &sp->rxd[i].rfs - (u32) sp->rxd;
                printk(KERN_INFO "%2.2x %4.4x RFS        = %16.16lx\n", i,
                       offset, (unsigned long) sp->rxd[i].rfs);
                offset = (u32) &sp->rxd[i].frag_info - (u32) sp->rxd;
                printk(KERN_INFO "%2.2x %4.4x frag_info   = %16.16lx\n", i,
                       offset, (unsigned long) sp->rxd[i].frag_info);
        }
}

static void ipg_dump_tfdlist(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;
        u32 offset;

        IPG_DEBUG_MSG("_dump_tfdlist\n");

        printk(KERN_INFO "tx_current         = %2.2x\n", sp->tx_current);
        printk(KERN_INFO "tx_dirty = %2.2x\n", sp->tx_dirty);
        printk(KERN_INFO "TFDList start address = %16.16lx\n",
               (unsigned long) sp->txd_map);
        printk(KERN_INFO "TFDListPtr register   = %8.8x%8.8x\n",
               ipg_r32(IPG_TFDLISTPTR1), ipg_r32(IPG_TFDLISTPTR0));

        for (i = 0; i < IPG_TFDLIST_LENGTH; i++) {
                offset = (u32) &sp->txd[i].next_desc - (u32) sp->txd;
                printk(KERN_INFO "%2.2x %4.4x TFDNextPtr = %16.16lx\n", i,
                       offset, (unsigned long) sp->txd[i].next_desc);

                offset = (u32) &sp->txd[i].tfc - (u32) sp->txd;
                printk(KERN_INFO "%2.2x %4.4x TFC        = %16.16lx\n", i,
                       offset, (unsigned long) sp->txd[i].tfc);
                offset = (u32) &sp->txd[i].frag_info - (u32) sp->txd;
                printk(KERN_INFO "%2.2x %4.4x frag_info   = %16.16lx\n", i,
                       offset, (unsigned long) sp->txd[i].frag_info);
        }
}
#endif

static void ipg_write_phy_ctl(void __iomem *ioaddr, u8 data)
{
        ipg_w8(IPG_PC_RSVD_MASK & data, PHY_CTRL);
        ndelay(IPG_PC_PHYCTRLWAIT_NS);
}

static void ipg_drive_phy_ctl_low_high(void __iomem *ioaddr, u8 data)
{
        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_LO | data);
        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_HI | data);
}

static void send_three_state(void __iomem *ioaddr, u8 phyctrlpolarity)
{
        phyctrlpolarity |= (IPG_PC_MGMTDATA & 0) | IPG_PC_MGMTDIR;

        ipg_drive_phy_ctl_low_high(ioaddr, phyctrlpolarity);
}

static void send_end(void __iomem *ioaddr, u8 phyctrlpolarity)
{
        ipg_w8((IPG_PC_MGMTCLK_LO | (IPG_PC_MGMTDATA & 0) | IPG_PC_MGMTDIR |
                phyctrlpolarity) & IPG_PC_RSVD_MASK, PHY_CTRL);
}

static u16 read_phy_bit(void __iomem * ioaddr, u8 phyctrlpolarity)
{
        u16 bit_data;

        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_LO | phyctrlpolarity);

        bit_data = ((ipg_r8(PHY_CTRL) & IPG_PC_MGMTDATA) >> 1) & 1;

        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_HI | phyctrlpolarity);

        return bit_data;
}

/*
 * Read a register from the Physical Layer device located
 * on the IPG NIC, using the IPG PHYCTRL register.
 */
static int mdio_read(struct net_device * dev, int phy_id, int phy_reg)
{
        void __iomem *ioaddr = ipg_ioaddr(dev);
        /*
         * The GMII mangement frame structure for a read is as follows:
         *
         * |Preamble|st|op|phyad|regad|ta|      data      |idle|
         * |< 32 1s>|01|10|AAAAA|RRRRR|z0|DDDDDDDDDDDDDDDD|z   |
         *
         * <32 1s> = 32 consecutive logic 1 values
         * A = bit of Physical Layer device address (MSB first)
         * R = bit of register address (MSB first)
         * z = High impedance state
         * D = bit of read data (MSB first)
         *
         * Transmission order is 'Preamble' field first, bits transmitted
         * left to right (first to last).
         */
        struct {
                u32 field;
                unsigned int len;
        } p[] = {
                { GMII_PREAMBLE,        32 },   /* Preamble */
                { GMII_ST,              2  },   /* ST */
                { GMII_READ,            2  },   /* OP */
                { phy_id,               5  },   /* PHYAD */
                { phy_reg,              5  },   /* REGAD */
                { 0x0000,               2  },   /* TA */
                { 0x0000,               16 },   /* DATA */
                { 0x0000,               1  }    /* IDLE */
        };
        unsigned int i, j;
        u8 polarity, data;

        polarity  = ipg_r8(PHY_CTRL);
        polarity &= (IPG_PC_DUPLEX_POLARITY | IPG_PC_LINK_POLARITY);

        /* Create the Preamble, ST, OP, PHYAD, and REGAD field. */
        for (j = 0; j < 5; j++) {
                for (i = 0; i < p[j].len; i++) {
                        /* For each variable length field, the MSB must be
                         * transmitted first. Rotate through the field bits,
                         * starting with the MSB, and move each bit into the
                         * the 1st (2^1) bit position (this is the bit position
                         * corresponding to the MgmtData bit of the PhyCtrl
                         * register for the IPG).
                         *
                         * Example: ST = 01;
                         *
                         *          First write a '0' to bit 1 of the PhyCtrl
                         *          register, then write a '1' to bit 1 of the
                         *          PhyCtrl register.
                         *
                         * To do this, right shift the MSB of ST by the value:
                         * [field length - 1 - #ST bits already written]
                         * then left shift this result by 1.
                         */
                        data  = (p[j].field >> (p[j].len - 1 - i)) << 1;
                        data &= IPG_PC_MGMTDATA;
                        data |= polarity | IPG_PC_MGMTDIR;

                        ipg_drive_phy_ctl_low_high(ioaddr, data);
                }
        }

        send_three_state(ioaddr, polarity);

        read_phy_bit(ioaddr, polarity);

        /*
         * For a read cycle, the bits for the next two fields (TA and
         * DATA) are driven by the PHY (the IPG reads these bits).
         */
        for (i = 0; i < p[6].len; i++) {
                p[6].field |=
                    (read_phy_bit(ioaddr, polarity) << (p[6].len - 1 - i));
        }

        send_three_state(ioaddr, polarity);
        send_three_state(ioaddr, polarity);
        send_three_state(ioaddr, polarity);
        send_end(ioaddr, polarity);

        /* Return the value of the DATA field. */
        return p[6].field;
}

/*
 * Write to a register from the Physical Layer device located
 * on the IPG NIC, using the IPG PHYCTRL register.
 */
static void mdio_write(struct net_device *dev, int phy_id, int phy_reg, int val)
{
        void __iomem *ioaddr = ipg_ioaddr(dev);
        /*
         * The GMII mangement frame structure for a read is as follows:
         *
         * |Preamble|st|op|phyad|regad|ta|      data      |idle|
         * |< 32 1s>|01|10|AAAAA|RRRRR|z0|DDDDDDDDDDDDDDDD|z   |
         *
         * <32 1s> = 32 consecutive logic 1 values
         * A = bit of Physical Layer device address (MSB first)
         * R = bit of register address (MSB first)
         * z = High impedance state
         * D = bit of write data (MSB first)
         *
         * Transmission order is 'Preamble' field first, bits transmitted
         * left to right (first to last).
         */
        struct {
                u32 field;
                unsigned int len;
        } p[] = {
                { GMII_PREAMBLE,        32 },   /* Preamble */
                { GMII_ST,              2  },   /* ST */
                { GMII_WRITE,           2  },   /* OP */
                { phy_id,               5  },   /* PHYAD */
                { phy_reg,              5  },   /* REGAD */
                { 0x0002,               2  },   /* TA */
                { val & 0xffff,         16 },   /* DATA */
                { 0x0000,               1  }    /* IDLE */
        };
        unsigned int i, j;
        u8 polarity, data;

        polarity  = ipg_r8(PHY_CTRL);
        polarity &= (IPG_PC_DUPLEX_POLARITY | IPG_PC_LINK_POLARITY);

        /* Create the Preamble, ST, OP, PHYAD, and REGAD field. */
        for (j = 0; j < 7; j++) {
                for (i = 0; i < p[j].len; i++) {
                        /* For each variable length field, the MSB must be
                         * transmitted first. Rotate through the field bits,
                         * starting with the MSB, and move each bit into the
                         * the 1st (2^1) bit position (this is the bit position
                         * corresponding to the MgmtData bit of the PhyCtrl
                         * register for the IPG).
                         *
                         * Example: ST = 01;
                         *
                         *          First write a '0' to bit 1 of the PhyCtrl
                         *          register, then write a '1' to bit 1 of the
                         *          PhyCtrl register.
                         *
                         * To do this, right shift the MSB of ST by the value:
                         * [field length - 1 - #ST bits already written]
                         * then left shift this result by 1.
                         */
                        data  = (p[j].field >> (p[j].len - 1 - i)) << 1;
                        data &= IPG_PC_MGMTDATA;
                        data |= polarity | IPG_PC_MGMTDIR;

                        ipg_drive_phy_ctl_low_high(ioaddr, data);
                }
        }

        /* The last cycle is a tri-state, so read from the PHY. */
        for (j = 7; j < 8; j++) {
                for (i = 0; i < p[j].len; i++) {
                        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_LO | polarity);

                        p[j].field |= ((ipg_r8(PHY_CTRL) &
                                IPG_PC_MGMTDATA) >> 1) << (p[j].len - 1 - i);

                        ipg_write_phy_ctl(ioaddr, IPG_PC_MGMTCLK_HI | polarity);
                }
        }
}

static void ipg_set_led_mode(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        u32 mode;

        mode = ipg_r32(ASIC_CTRL);
        mode &= ~(IPG_AC_LED_MODE_BIT_1 | IPG_AC_LED_MODE | IPG_AC_LED_SPEED);

        if ((sp->LED_Mode & 0x03) > 1)
                mode |= IPG_AC_LED_MODE_BIT_1;  /* Write Asic Control Bit 29 */

        if ((sp->LED_Mode & 0x01) == 1)
                mode |= IPG_AC_LED_MODE;        /* Write Asic Control Bit 14 */

        if ((sp->LED_Mode & 0x08) == 8)
                mode |= IPG_AC_LED_SPEED;       /* Write Asic Control Bit 27 */

        ipg_w32(mode, ASIC_CTRL);
}

static void ipg_set_phy_set(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        int physet;

        physet = ipg_r8(PHY_SET);
        physet &= ~(IPG_PS_MEM_LENB9B | IPG_PS_MEM_LEN9 | IPG_PS_NON_COMPDET);
        physet |= ((sp->LED_Mode & 0x70) >> 4);
        ipg_w8(physet, PHY_SET);
}

static int ipg_reset(struct net_device *dev, u32 resetflags)
{
        /* Assert functional resets via the IPG AsicCtrl
         * register as specified by the 'resetflags' input
         * parameter.
         */
        void __iomem *ioaddr = ipg_ioaddr(dev);
        unsigned int timeout_count = 0;

        IPG_DEBUG_MSG("_reset\n");

        ipg_w32(ipg_r32(ASIC_CTRL) | resetflags, ASIC_CTRL);

        /* Delay added to account for problem with 10Mbps reset. */
        mdelay(IPG_AC_RESETWAIT);

        while (IPG_AC_RESET_BUSY & ipg_r32(ASIC_CTRL)) {
                mdelay(IPG_AC_RESETWAIT);
                if (++timeout_count > IPG_AC_RESET_TIMEOUT)
                        return -ETIME;
        }
        /* Set LED Mode in Asic Control */
        ipg_set_led_mode(dev);

        /* Set PHYSet Register Value */
        ipg_set_phy_set(dev);
        return 0;
}

/* Find the GMII PHY address. */
static int ipg_find_phyaddr(struct net_device *dev)
{
        unsigned int phyaddr, i;

        for (i = 0; i < 32; i++) {
                u32 status;

                /* Search for the correct PHY address among 32 possible. */
                phyaddr = (IPG_NIC_PHY_ADDRESS + i) % 32;

                /* 10/22/03 Grace change verify from GMII_PHY_STATUS to
                   GMII_PHY_ID1
                 */

                status = mdio_read(dev, phyaddr, MII_BMSR);

                if ((status != 0xFFFF) && (status != 0))
                        return phyaddr;
        }

        return 0x1f;
}

/*
 * Configure IPG based on result of IEEE 802.3 PHY
 * auto-negotiation.
 */
static int ipg_config_autoneg(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int txflowcontrol;
        unsigned int rxflowcontrol;
        unsigned int fullduplex;
        unsigned int gig;
        u32 mac_ctrl_val;
        u32 asicctrl;
        u8 phyctrl;

        IPG_DEBUG_MSG("_config_autoneg\n");

        asicctrl = ipg_r32(ASIC_CTRL);
        phyctrl = ipg_r8(PHY_CTRL);
        mac_ctrl_val = ipg_r32(MAC_CTRL);

        /* Set flags for use in resolving auto-negotation, assuming
         * non-1000Mbps, half duplex, no flow control.
         */
        fullduplex = 0;
        txflowcontrol = 0;
        rxflowcontrol = 0;
        gig = 0;

        /* To accomodate a problem in 10Mbps operation,
         * set a global flag if PHY running in 10Mbps mode.
         */
        sp->tenmbpsmode = 0;

        printk(KERN_INFO "%s: Link speed = ", dev->name);

        /* Determine actual speed of operation. */
        switch (phyctrl & IPG_PC_LINK_SPEED) {
        case IPG_PC_LINK_SPEED_10MBPS:
                printk("10Mbps.\n");
                printk(KERN_INFO "%s: 10Mbps operational mode enabled.\n",
                       dev->name);
                sp->tenmbpsmode = 1;
                break;
        case IPG_PC_LINK_SPEED_100MBPS:
                printk("100Mbps.\n");
                break;
        case IPG_PC_LINK_SPEED_1000MBPS:
                printk("1000Mbps.\n");
                gig = 1;
                break;
        default:
                printk("undefined!\n");
                return 0;
        }

        if (phyctrl & IPG_PC_DUPLEX_STATUS) {
                fullduplex = 1;
                txflowcontrol = 1;
                rxflowcontrol = 1;
        }

        /* Configure full duplex, and flow control. */
        if (fullduplex == 1) {
                /* Configure IPG for full duplex operation. */
                printk(KERN_INFO "%s: setting full duplex, ", dev->name);

                mac_ctrl_val |= IPG_MC_DUPLEX_SELECT_FD;

                if (txflowcontrol == 1) {
                        printk("TX flow control");
                        mac_ctrl_val |= IPG_MC_TX_FLOW_CONTROL_ENABLE;
                } else {
                        printk("no TX flow control");
                        mac_ctrl_val &= ~IPG_MC_TX_FLOW_CONTROL_ENABLE;
                }

                if (rxflowcontrol == 1) {
                        printk(", RX flow control.");
                        mac_ctrl_val |= IPG_MC_RX_FLOW_CONTROL_ENABLE;
                } else {
                        printk(", no RX flow control.");
                        mac_ctrl_val &= ~IPG_MC_RX_FLOW_CONTROL_ENABLE;
                }

                printk("\n");
        } else {
                /* Configure IPG for half duplex operation. */
                printk(KERN_INFO "%s: setting half duplex, "
                       "no TX flow control, no RX flow control.\n", dev->name);

                mac_ctrl_val &= ~IPG_MC_DUPLEX_SELECT_FD &
                        ~IPG_MC_TX_FLOW_CONTROL_ENABLE &
                        ~IPG_MC_RX_FLOW_CONTROL_ENABLE;
        }
        ipg_w32(mac_ctrl_val, MAC_CTRL);
        return 0;
}

/* Determine and configure multicast operation and set
 * receive mode for IPG.
 */
static void ipg_nic_set_multicast_list(struct net_device *dev)
{
        void __iomem *ioaddr = ipg_ioaddr(dev);
        struct dev_mc_list *mc_list_ptr;
        unsigned int hashindex;
        u32 hashtable[2];
        u8 receivemode;

        IPG_DEBUG_MSG("_nic_set_multicast_list\n");

        receivemode = IPG_RM_RECEIVEUNICAST | IPG_RM_RECEIVEBROADCAST;

        if (dev->flags & IFF_PROMISC) {
                /* NIC to be configured in promiscuous mode. */
                receivemode = IPG_RM_RECEIVEALLFRAMES;
        } else if ((dev->flags & IFF_ALLMULTI) ||
                   (dev->flags & IFF_MULTICAST &
                    (dev->mc_count > IPG_MULTICAST_HASHTABLE_SIZE))) {
                /* NIC to be configured to receive all multicast
                 * frames. */
                receivemode |= IPG_RM_RECEIVEMULTICAST;
        } else if (dev->flags & IFF_MULTICAST & (dev->mc_count > 0)) {
                /* NIC to be configured to receive selected
                 * multicast addresses. */
                receivemode |= IPG_RM_RECEIVEMULTICASTHASH;
        }

        /* Calculate the bits to set for the 64 bit, IPG HASHTABLE.
         * The IPG applies a cyclic-redundancy-check (the same CRC
         * used to calculate the frame data FCS) to the destination
         * address all incoming multicast frames whose destination
         * address has the multicast bit set. The least significant
         * 6 bits of the CRC result are used as an addressing index
         * into the hash table. If the value of the bit addressed by
         * this index is a 1, the frame is passed to the host system.
         */

        /* Clear hashtable. */
        hashtable[0] = 0x00000000;
        hashtable[1] = 0x00000000;

        /* Cycle through all multicast addresses to filter. */
        for (mc_list_ptr = dev->mc_list;
             mc_list_ptr != NULL; mc_list_ptr = mc_list_ptr->next) {
                /* Calculate CRC result for each multicast address. */
                hashindex = crc32_le(0xffffffff, mc_list_ptr->dmi_addr,
                                     ETH_ALEN);

                /* Use only the least significant 6 bits. */
                hashindex = hashindex & 0x3F;

                /* Within "hashtable", set bit number "hashindex"
                 * to a logic 1.
                 */
                set_bit(hashindex, (void *)hashtable);
        }

        /* Write the value of the hashtable, to the 4, 16 bit
         * HASHTABLE IPG registers.
         */
        ipg_w32(hashtable[0], HASHTABLE_0);
        ipg_w32(hashtable[1], HASHTABLE_1);

        ipg_w8(IPG_RM_RSVD_MASK & receivemode, RECEIVE_MODE);

        IPG_DEBUG_MSG("ReceiveMode = %x\n", ipg_r8(RECEIVE_MODE));
}

static int ipg_io_config(struct net_device *dev)
{
        void __iomem *ioaddr = ipg_ioaddr(dev);
        u32 origmacctrl;
        u32 restoremacctrl;

        IPG_DEBUG_MSG("_io_config\n");

        origmacctrl = ipg_r32(MAC_CTRL);

        restoremacctrl = origmacctrl | IPG_MC_STATISTICS_ENABLE;

        /* Based on compilation option, determine if FCS is to be
         * stripped on receive frames by IPG.
         */
        if (!IPG_STRIP_FCS_ON_RX)
                restoremacctrl |= IPG_MC_RCV_FCS;

        /* Determine if transmitter and/or receiver are
         * enabled so we may restore MACCTRL correctly.
         */
        if (origmacctrl & IPG_MC_TX_ENABLED)
                restoremacctrl |= IPG_MC_TX_ENABLE;

        if (origmacctrl & IPG_MC_RX_ENABLED)
                restoremacctrl |= IPG_MC_RX_ENABLE;

        /* Transmitter and receiver must be disabled before setting
         * IFSSelect.
         */
        ipg_w32((origmacctrl & (IPG_MC_RX_DISABLE | IPG_MC_TX_DISABLE)) &
                IPG_MC_RSVD_MASK, MAC_CTRL);

        /* Now that transmitter and receiver are disabled, write
         * to IFSSelect.
         */
        ipg_w32((origmacctrl & IPG_MC_IFS_96BIT) & IPG_MC_RSVD_MASK, MAC_CTRL);

        /* Set RECEIVEMODE register. */
        ipg_nic_set_multicast_list(dev);

        ipg_w16(IPG_MAX_RXFRAME_SIZE, MAX_FRAME_SIZE);

        ipg_w8(IPG_RXDMAPOLLPERIOD_VALUE,   RX_DMA_POLL_PERIOD);
        ipg_w8(IPG_RXDMAURGENTTHRESH_VALUE, RX_DMA_URGENT_THRESH);
        ipg_w8(IPG_RXDMABURSTTHRESH_VALUE,  RX_DMA_BURST_THRESH);
        ipg_w8(IPG_TXDMAPOLLPERIOD_VALUE,   TX_DMA_POLL_PERIOD);
        ipg_w8(IPG_TXDMAURGENTTHRESH_VALUE, TX_DMA_URGENT_THRESH);
        ipg_w8(IPG_TXDMABURSTTHRESH_VALUE,  TX_DMA_BURST_THRESH);
        ipg_w16((IPG_IE_HOST_ERROR | IPG_IE_TX_DMA_COMPLETE |
                 IPG_IE_TX_COMPLETE | IPG_IE_INT_REQUESTED |
                 IPG_IE_UPDATE_STATS | IPG_IE_LINK_EVENT |
                 IPG_IE_RX_DMA_COMPLETE | IPG_IE_RX_DMA_PRIORITY), INT_ENABLE);
        ipg_w16(IPG_FLOWONTHRESH_VALUE,  FLOW_ON_THRESH);
        ipg_w16(IPG_FLOWOFFTHRESH_VALUE, FLOW_OFF_THRESH);

        /* IPG multi-frag frame bug workaround.
         * Per silicon revision B3 eratta.
         */
        ipg_w16(ipg_r16(DEBUG_CTRL) | 0x0200, DEBUG_CTRL);

        /* IPG TX poll now bug workaround.
         * Per silicon revision B3 eratta.
         */
        ipg_w16(ipg_r16(DEBUG_CTRL) | 0x0010, DEBUG_CTRL);

        /* IPG RX poll now bug workaround.
         * Per silicon revision B3 eratta.
         */
        ipg_w16(ipg_r16(DEBUG_CTRL) | 0x0020, DEBUG_CTRL);

        /* Now restore MACCTRL to original setting. */
        ipg_w32(IPG_MC_RSVD_MASK & restoremacctrl, MAC_CTRL);

        /* Disable unused RMON statistics. */
        ipg_w32(IPG_RZ_ALL, RMON_STATISTICS_MASK);

        /* Disable unused MIB statistics. */
        ipg_w32(IPG_SM_MACCONTROLFRAMESXMTD | IPG_SM_MACCONTROLFRAMESRCVD |
                IPG_SM_BCSTOCTETXMTOK_BCSTFRAMESXMTDOK | IPG_SM_TXJUMBOFRAMES |
                IPG_SM_MCSTOCTETXMTOK_MCSTFRAMESXMTDOK | IPG_SM_RXJUMBOFRAMES |
                IPG_SM_BCSTOCTETRCVDOK_BCSTFRAMESRCVDOK |
                IPG_SM_UDPCHECKSUMERRORS | IPG_SM_TCPCHECKSUMERRORS |
                IPG_SM_IPCHECKSUMERRORS, STATISTICS_MASK);

        return 0;
}

/*
 * Create a receive buffer within system memory and update
 * NIC private structure appropriately.
 */
static int ipg_get_rxbuff(struct net_device *dev, int entry)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        struct ipg_rx *rxfd = sp->rxd + entry;
        struct sk_buff *skb;
        u64 rxfragsize;

        IPG_DEBUG_MSG("_get_rxbuff\n");

        skb = netdev_alloc_skb(dev, IPG_RXSUPPORT_SIZE + NET_IP_ALIGN);
        if (!skb) {
                sp->RxBuff[entry] = NULL;
                return -ENOMEM;
        }

        /* Adjust the data start location within the buffer to
         * align IP address field to a 16 byte boundary.
         */
        skb_reserve(skb, NET_IP_ALIGN);

        /* Associate the receive buffer with the IPG NIC. */
        skb->dev = dev;

        /* Save the address of the sk_buff structure. */
        sp->RxBuff[entry] = skb;

        rxfd->frag_info = cpu_to_le64(pci_map_single(sp->pdev, skb->data,
                sp->rx_buf_sz, PCI_DMA_FROMDEVICE));

        /* Set the RFD fragment length. */
        rxfragsize = IPG_RXFRAG_SIZE;
        rxfd->frag_info |= cpu_to_le64((rxfragsize << 48) & IPG_RFI_FRAGLEN);

        return 0;
}

static int init_rfdlist(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;

        IPG_DEBUG_MSG("_init_rfdlist\n");

        for (i = 0; i < IPG_RFDLIST_LENGTH; i++) {
                struct ipg_rx *rxfd = sp->rxd + i;

                if (sp->RxBuff[i]) {
                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(rxfd->frag_info) & ~IPG_RFI_FRAGLEN,
                                sp->rx_buf_sz, PCI_DMA_FROMDEVICE);
                        dev_kfree_skb_irq(sp->RxBuff[i]);
                        sp->RxBuff[i] = NULL;
                }

                /* Clear out the RFS field. */
                rxfd->rfs = 0x0000000000000000;

                if (ipg_get_rxbuff(dev, i) < 0) {
                        /*
                         * A receive buffer was not ready, break the
                         * RFD list here.
                         */
                        IPG_DEBUG_MSG("Cannot allocate Rx buffer.\n");

                        /* Just in case we cannot allocate a single RFD.
                         * Should not occur.
                         */
                        if (i == 0) {
                                printk(KERN_ERR "%s: No memory available"
                                        " for RFD list.\n", dev->name);
                                return -ENOMEM;
                        }
                }

                rxfd->next_desc = cpu_to_le64(sp->rxd_map +
                        sizeof(struct ipg_rx)*(i + 1));
        }
        sp->rxd[i - 1].next_desc = cpu_to_le64(sp->rxd_map);

        sp->rx_current = 0;
        sp->rx_dirty = 0;

        /* Write the location of the RFDList to the IPG. */
        ipg_w32((u32) sp->rxd_map, RFD_LIST_PTR_0);
        ipg_w32(0x00000000, RFD_LIST_PTR_1);

        return 0;
}

static void init_tfdlist(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;

        IPG_DEBUG_MSG("_init_tfdlist\n");

        for (i = 0; i < IPG_TFDLIST_LENGTH; i++) {
                struct ipg_tx *txfd = sp->txd + i;

                txfd->tfc = cpu_to_le64(IPG_TFC_TFDDONE);

                if (sp->TxBuff[i]) {
                        dev_kfree_skb_irq(sp->TxBuff[i]);
                        sp->TxBuff[i] = NULL;
                }

                txfd->next_desc = cpu_to_le64(sp->txd_map +
                        sizeof(struct ipg_tx)*(i + 1));
        }
        sp->txd[i - 1].next_desc = cpu_to_le64(sp->txd_map);

        sp->tx_current = 0;
        sp->tx_dirty = 0;

        /* Write the location of the TFDList to the IPG. */
        IPG_DDEBUG_MSG("Starting TFDListPtr = %8.8x\n",
                       (u32) sp->txd_map);
        ipg_w32((u32) sp->txd_map, TFD_LIST_PTR_0);
        ipg_w32(0x00000000, TFD_LIST_PTR_1);

        sp->ResetCurrentTFD = 1;
}

/*
 * Free all transmit buffers which have already been transfered
 * via DMA to the IPG.
 */
static void ipg_nic_txfree(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        unsigned int released, pending, dirty;

        IPG_DEBUG_MSG("_nic_txfree\n");

        pending = sp->tx_current - sp->tx_dirty;
        dirty = sp->tx_dirty % IPG_TFDLIST_LENGTH;

        for (released = 0; released < pending; released++) {
                struct sk_buff *skb = sp->TxBuff[dirty];
                struct ipg_tx *txfd = sp->txd + dirty;

                IPG_DEBUG_MSG("TFC = %16.16lx\n", (unsigned long) txfd->tfc);

                /* Look at each TFD's TFC field beginning
                 * at the last freed TFD up to the current TFD.
                 * If the TFDDone bit is set, free the associated
                 * buffer.
                 */
                if (!(txfd->tfc & cpu_to_le64(IPG_TFC_TFDDONE)))
                        break;

                /* Free the transmit buffer. */
                if (skb) {
                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(txfd->frag_info) & ~IPG_TFI_FRAGLEN,
                                skb->len, PCI_DMA_TODEVICE);

                        dev_kfree_skb_irq(skb);

                        sp->TxBuff[dirty] = NULL;
                }
                dirty = (dirty + 1) % IPG_TFDLIST_LENGTH;
        }

        sp->tx_dirty += released;

        if (netif_queue_stopped(dev) &&
            (sp->tx_current != (sp->tx_dirty + IPG_TFDLIST_LENGTH))) {
                netif_wake_queue(dev);
        }
}

static void ipg_tx_timeout(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;

        ipg_reset(dev, IPG_AC_TX_RESET | IPG_AC_DMA | IPG_AC_NETWORK |
                  IPG_AC_FIFO);

        spin_lock_irq(&sp->lock);

        /* Re-configure after DMA reset. */
        if (ipg_io_config(dev) < 0) {
                printk(KERN_INFO "%s: Error during re-configuration.\n",
                       dev->name);
        }

        init_tfdlist(dev);

        spin_unlock_irq(&sp->lock);

        ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_TX_ENABLE) & IPG_MC_RSVD_MASK,
                MAC_CTRL);
}

/*
 * For TxComplete interrupts, free all transmit
 * buffers which have already been transfered via DMA
 * to the IPG.
 */
static void ipg_nic_txcleanup(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;

        IPG_DEBUG_MSG("_nic_txcleanup\n");

        for (i = 0; i < IPG_TFDLIST_LENGTH; i++) {
                /* Reading the TXSTATUS register clears the
                 * TX_COMPLETE interrupt.
                 */
                u32 txstatusdword = ipg_r32(TX_STATUS);

                IPG_DEBUG_MSG("TxStatus = %8.8x\n", txstatusdword);

                /* Check for Transmit errors. Error bits only valid if
                 * TX_COMPLETE bit in the TXSTATUS register is a 1.
                 */
                if (!(txstatusdword & IPG_TS_TX_COMPLETE))
                        break;

                /* If in 10Mbps mode, indicate transmit is ready. */
                if (sp->tenmbpsmode) {
                        netif_wake_queue(dev);
                }

                /* Transmit error, increment stat counters. */
                if (txstatusdword & IPG_TS_TX_ERROR) {
                        IPG_DEBUG_MSG("Transmit error.\n");
                        sp->stats.tx_errors++;
                }

                /* Late collision, re-enable transmitter. */
                if (txstatusdword & IPG_TS_LATE_COLLISION) {
                        IPG_DEBUG_MSG("Late collision on transmit.\n");
                        ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_TX_ENABLE) &
                                IPG_MC_RSVD_MASK, MAC_CTRL);
                }

                /* Maximum collisions, re-enable transmitter. */
                if (txstatusdword & IPG_TS_TX_MAX_COLL) {
                        IPG_DEBUG_MSG("Maximum collisions on transmit.\n");
                        ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_TX_ENABLE) &
                                IPG_MC_RSVD_MASK, MAC_CTRL);
                }

                /* Transmit underrun, reset and re-enable
                 * transmitter.
                 */
                if (txstatusdword & IPG_TS_TX_UNDERRUN) {
                        IPG_DEBUG_MSG("Transmitter underrun.\n");
                        sp->stats.tx_fifo_errors++;
                        ipg_reset(dev, IPG_AC_TX_RESET | IPG_AC_DMA |
                                  IPG_AC_NETWORK | IPG_AC_FIFO);

                        /* Re-configure after DMA reset. */
                        if (ipg_io_config(dev) < 0) {
                                printk(KERN_INFO
                                       "%s: Error during re-configuration.\n",
                                       dev->name);
                        }
                        init_tfdlist(dev);

                        ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_TX_ENABLE) &
                                IPG_MC_RSVD_MASK, MAC_CTRL);
                }
        }

        ipg_nic_txfree(dev);
}

/* Provides statistical information about the IPG NIC. */
static struct net_device_stats *ipg_nic_get_stats(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        u16 temp1;
        u16 temp2;

        IPG_DEBUG_MSG("_nic_get_stats\n");

        /* Check to see if the NIC has been initialized via nic_open,
         * before trying to read statistic registers.
         */
        if (!test_bit(__LINK_STATE_START, &dev->state))
                return &sp->stats;

        sp->stats.rx_packets += ipg_r32(IPG_FRAMESRCVDOK);
        sp->stats.tx_packets += ipg_r32(IPG_FRAMESXMTDOK);
        sp->stats.rx_bytes += ipg_r32(IPG_OCTETRCVOK);
        sp->stats.tx_bytes += ipg_r32(IPG_OCTETXMTOK);
        temp1 = ipg_r16(IPG_FRAMESLOSTRXERRORS);
        sp->stats.rx_errors += temp1;
        sp->stats.rx_missed_errors += temp1;
        temp1 = ipg_r32(IPG_SINGLECOLFRAMES) + ipg_r32(IPG_MULTICOLFRAMES) +
                ipg_r32(IPG_LATECOLLISIONS);
        temp2 = ipg_r16(IPG_CARRIERSENSEERRORS);
        sp->stats.collisions += temp1;
        sp->stats.tx_dropped += ipg_r16(IPG_FRAMESABORTXSCOLLS);
        sp->stats.tx_errors += ipg_r16(IPG_FRAMESWEXDEFERRAL) +
                ipg_r32(IPG_FRAMESWDEFERREDXMT) + temp1 + temp2;
        sp->stats.multicast += ipg_r32(IPG_MCSTOCTETRCVDOK);

        /* detailed tx_errors */
        sp->stats.tx_carrier_errors += temp2;

        /* detailed rx_errors */
        sp->stats.rx_length_errors += ipg_r16(IPG_INRANGELENGTHERRORS) +
                ipg_r16(IPG_FRAMETOOLONGERRRORS);
        sp->stats.rx_crc_errors += ipg_r16(IPG_FRAMECHECKSEQERRORS);

        /* Unutilized IPG statistic registers. */
        ipg_r32(IPG_MCSTFRAMESRCVDOK);

        return &sp->stats;
}

/* Restore used receive buffers. */
static int ipg_nic_rxrestore(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        const unsigned int curr = sp->rx_current;
        unsigned int dirty = sp->rx_dirty;

        IPG_DEBUG_MSG("_nic_rxrestore\n");

        for (dirty = sp->rx_dirty; curr - dirty > 0; dirty++) {
                unsigned int entry = dirty % IPG_RFDLIST_LENGTH;

                /* rx_copybreak may poke hole here and there. */
                if (sp->RxBuff[entry])
                        continue;

                /* Generate a new receive buffer to replace the
                 * current buffer (which will be released by the
                 * Linux system).
                 */
                if (ipg_get_rxbuff(dev, entry) < 0) {
                        IPG_DEBUG_MSG("Cannot allocate new Rx buffer.\n");

                        break;
                }

                /* Reset the RFS field. */
                sp->rxd[entry].rfs = 0x0000000000000000;
        }
        sp->rx_dirty = dirty;

        return 0;
}

#ifdef JUMBO_FRAME

/* use jumboindex and jumbosize to control jumbo frame status
   initial status is jumboindex=-1 and jumbosize=0
   1. jumboindex = -1 and jumbosize=0 : previous jumbo frame has been done.
   2. jumboindex != -1 and jumbosize != 0 : jumbo frame is not over size and receiving
   3. jumboindex = -1 and jumbosize != 0 : jumbo frame is over size, already dump
                previous receiving and need to continue dumping the current one
*/
enum {
        NormalPacket,
        ErrorPacket
};

enum {
        Frame_NoStart_NoEnd     = 0,
        Frame_WithStart         = 1,
        Frame_WithEnd           = 10,
        Frame_WithStart_WithEnd = 11
};

inline void ipg_nic_rx_free_skb(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        unsigned int entry = sp->rx_current % IPG_RFDLIST_LENGTH;

        if (sp->RxBuff[entry]) {
                struct ipg_rx *rxfd = sp->rxd + entry;

                pci_unmap_single(sp->pdev,
                        le64_to_cpu(rxfd->frag_info & ~IPG_RFI_FRAGLEN),
                        sp->rx_buf_sz, PCI_DMA_FROMDEVICE);
                dev_kfree_skb_irq(sp->RxBuff[entry]);
                sp->RxBuff[entry] = NULL;
        }
}

inline int ipg_nic_rx_check_frame_type(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        struct ipg_rx *rxfd = sp->rxd + (sp->rx_current % IPG_RFDLIST_LENGTH);
        int type = Frame_NoStart_NoEnd;

        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_FRAMESTART)
                type += Frame_WithStart;
        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_FRAMEEND)
                type += Frame_WithEnd;
        return type;
}

inline int ipg_nic_rx_check_error(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        unsigned int entry = sp->rx_current % IPG_RFDLIST_LENGTH;
        struct ipg_rx *rxfd = sp->rxd + entry;

        if (IPG_DROP_ON_RX_ETH_ERRORS && (le64_to_cpu(rxfd->rfs) &
             (IPG_RFS_RXFIFOOVERRUN | IPG_RFS_RXRUNTFRAME |
              IPG_RFS_RXALIGNMENTERROR | IPG_RFS_RXFCSERROR |
              IPG_RFS_RXOVERSIZEDFRAME | IPG_RFS_RXLENGTHERROR))) {
                IPG_DEBUG_MSG("Rx error, RFS = %16.16lx\n",
                              (unsigned long) rxfd->rfs);

                /* Increment general receive error statistic. */
                sp->stats.rx_errors++;

                /* Increment detailed receive error statistics. */
                if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFIFOOVERRUN) {
                        IPG_DEBUG_MSG("RX FIFO overrun occured.\n");

                        sp->stats.rx_fifo_errors++;
                }

                if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXRUNTFRAME) {
                        IPG_DEBUG_MSG("RX runt occured.\n");
                        sp->stats.rx_length_errors++;
                }

                /* Do nothing for IPG_RFS_RXOVERSIZEDFRAME,
                 * error count handled by a IPG statistic register.
                 */

                if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXALIGNMENTERROR) {
                        IPG_DEBUG_MSG("RX alignment error occured.\n");
                        sp->stats.rx_frame_errors++;
                }

                /* Do nothing for IPG_RFS_RXFCSERROR, error count
                 * handled by a IPG statistic register.
                 */

                /* Free the memory associated with the RX
                 * buffer since it is erroneous and we will
                 * not pass it to higher layer processes.
                 */
                if (sp->RxBuff[entry]) {
                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(rxfd->frag_info & ~IPG_RFI_FRAGLEN),
                                sp->rx_buf_sz, PCI_DMA_FROMDEVICE);

                        dev_kfree_skb_irq(sp->RxBuff[entry]);
                        sp->RxBuff[entry] = NULL;
                }
                return ErrorPacket;
        }
        return NormalPacket;
}

static void ipg_nic_rx_with_start_and_end(struct net_device *dev,
                                          struct ipg_nic_private *sp,
                                          struct ipg_rx *rxfd, unsigned entry)
{
        struct SJumbo *jumbo = &sp->Jumbo;
        struct sk_buff *skb;
        int framelen;

        if (jumbo->FoundStart) {
                dev_kfree_skb_irq(jumbo->skb);
                jumbo->FoundStart = 0;
                jumbo->CurrentSize = 0;
                jumbo->skb = NULL;
        }

        // 1: found error, 0 no error
        if (ipg_nic_rx_check_error(dev) != NormalPacket)
                return;

        skb = sp->RxBuff[entry];
        if (!skb)
                return;

        // accept this frame and send to upper layer
        framelen = le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFRAMELEN;
        if (framelen > IPG_RXFRAG_SIZE)
                framelen = IPG_RXFRAG_SIZE;

        skb_put(skb, framelen);
        skb->protocol = eth_type_trans(skb, dev);
        skb->ip_summed = CHECKSUM_NONE;
        netif_rx(skb);
        dev->last_rx = jiffies;
        sp->RxBuff[entry] = NULL;
}

static void ipg_nic_rx_with_start(struct net_device *dev,
                                  struct ipg_nic_private *sp,
                                  struct ipg_rx *rxfd, unsigned entry)
{
        struct SJumbo *jumbo = &sp->Jumbo;
        struct pci_dev *pdev = sp->pdev;
        struct sk_buff *skb;

        // 1: found error, 0 no error
        if (ipg_nic_rx_check_error(dev) != NormalPacket)
                return;

        // accept this frame and send to upper layer
        skb = sp->RxBuff[entry];
        if (!skb)
                return;

        if (jumbo->FoundStart)
                dev_kfree_skb_irq(jumbo->skb);

        pci_unmap_single(pdev, le64_to_cpu(rxfd->frag_info & ~IPG_RFI_FRAGLEN),
                         sp->rx_buf_sz, PCI_DMA_FROMDEVICE);

        skb_put(skb, IPG_RXFRAG_SIZE);

        jumbo->FoundStart = 1;
        jumbo->CurrentSize = IPG_RXFRAG_SIZE;
        jumbo->skb = skb;

        sp->RxBuff[entry] = NULL;
        dev->last_rx = jiffies;
}

static void ipg_nic_rx_with_end(struct net_device *dev,
                                struct ipg_nic_private *sp,
                                struct ipg_rx *rxfd, unsigned entry)
{
        struct SJumbo *jumbo = &sp->Jumbo;

        //1: found error, 0 no error
        if (ipg_nic_rx_check_error(dev) == NormalPacket) {
                struct sk_buff *skb = sp->RxBuff[entry];

                if (!skb)
                        return;

                if (jumbo->FoundStart) {
                        int framelen, endframelen;

                        framelen = le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFRAMELEN;

                        endframeLen = framelen - jumbo->CurrentSize;
                        /*
                        if (framelen > IPG_RXFRAG_SIZE)
                                framelen=IPG_RXFRAG_SIZE;
                         */
                        if (framelen > IPG_RXSUPPORT_SIZE)
                                dev_kfree_skb_irq(jumbo->skb);
                        else {
                                memcpy(skb_put(jumbo->skb, endframeLen),
                                       skb->data, endframeLen);

                                jumbo->skb->protocol =
                                    eth_type_trans(jumbo->skb, dev);

                                jumbo->skb->ip_summed = CHECKSUM_NONE;
                                netif_rx(jumbo->skb);
                        }
                }

                dev->last_rx = jiffies;
                jumbo->FoundStart = 0;
                jumbo->CurrentSize = 0;
                jumbo->skb = NULL;

                ipg_nic_rx_free_skb(dev);
        } else {
                dev_kfree_skb_irq(jumbo->skb);
                jumbo->FoundStart = 0;
                jumbo->CurrentSize = 0;
                jumbo->skb = NULL;
        }
}

static void ipg_nic_rx_no_start_no_end(struct net_device *dev,
                                       struct ipg_nic_private *sp,
                                       struct ipg_rx *rxfd, unsigned entry)
{
        struct SJumbo *jumbo = &sp->Jumbo;

        //1: found error, 0 no error
        if (ipg_nic_rx_check_error(dev) == NormalPacket) {
                struct sk_buff *skb = sp->RxBuff[entry];

                if (skb) {
                        if (jumbo->FoundStart) {
                                jumbo->CurrentSize += IPG_RXFRAG_SIZE;
                                if (jumbo->CurrentSize <= IPG_RXSUPPORT_SIZE) {
                                        memcpy(skb_put(jumbo->skb,
                                                       IPG_RXFRAG_SIZE),
                                               skb->data, IPG_RXFRAG_SIZE);
                                }
                        }
                        dev->last_rx = jiffies;
                        ipg_nic_rx_free_skb(dev);
                }
        } else {
                dev_kfree_skb_irq(jumbo->skb);
                jumbo->FoundStart = 0;
                jumbo->CurrentSize = 0;
                jumbo->skb = NULL;
        }
}

static int ipg_nic_rx(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        unsigned int curr = sp->rx_current;
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;

        IPG_DEBUG_MSG("_nic_rx\n");

        for (i = 0; i < IPG_MAXRFDPROCESS_COUNT; i++, curr++) {
                unsigned int entry = curr % IPG_RFDLIST_LENGTH;
                struct ipg_rx *rxfd = sp->rxd + entry;

                if (!(rxfd->rfs & le64_to_cpu(IPG_RFS_RFDDONE)))
                        break;

                switch (ipg_nic_rx_check_frame_type(dev)) {
                case Frame_WithStart_WithEnd:
                        ipg_nic_rx_with_start_and_end(dev, tp, rxfd, entry);
                        break;
                case Frame_WithStart:
                        ipg_nic_rx_with_start(dev, tp, rxfd, entry);
                        break;
                case Frame_WithEnd:
                        ipg_nic_rx_with_end(dev, tp, rxfd, entry);
                        break;
                case Frame_NoStart_NoEnd:
                        ipg_nic_rx_no_start_no_end(dev, tp, rxfd, entry);
                        break;
                }
        }

        sp->rx_current = curr;

        if (i == IPG_MAXRFDPROCESS_COUNT) {
                /* There are more RFDs to process, however the
                 * allocated amount of RFD processing time has
                 * expired. Assert Interrupt Requested to make
                 * sure we come back to process the remaining RFDs.
                 */
                ipg_w32(ipg_r32(ASIC_CTRL) | IPG_AC_INT_REQUEST, ASIC_CTRL);
        }

        ipg_nic_rxrestore(dev);

        return 0;
}

#else
static int ipg_nic_rx(struct net_device *dev)
{
        /* Transfer received Ethernet frames to higher network layers. */
        struct ipg_nic_private *sp = netdev_priv(dev);
        unsigned int curr = sp->rx_current;
        void __iomem *ioaddr = sp->ioaddr;
        struct ipg_rx *rxfd;
        unsigned int i;

        IPG_DEBUG_MSG("_nic_rx\n");

#define __RFS_MASK \
        cpu_to_le64(IPG_RFS_RFDDONE | IPG_RFS_FRAMESTART | IPG_RFS_FRAMEEND)

        for (i = 0; i < IPG_MAXRFDPROCESS_COUNT; i++, curr++) {
                unsigned int entry = curr % IPG_RFDLIST_LENGTH;
                struct sk_buff *skb = sp->RxBuff[entry];
                unsigned int framelen;

                rxfd = sp->rxd + entry;

                if (((rxfd->rfs & __RFS_MASK) != __RFS_MASK) || !skb)
                        break;

                /* Get received frame length. */
                framelen = le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFRAMELEN;

                /* Check for jumbo frame arrival with too small
                 * RXFRAG_SIZE.
                 */
                if (framelen > IPG_RXFRAG_SIZE) {
                        IPG_DEBUG_MSG
                            ("RFS FrameLen > allocated fragment size.\n");

                        framelen = IPG_RXFRAG_SIZE;
                }

                if ((IPG_DROP_ON_RX_ETH_ERRORS && (le64_to_cpu(rxfd->rfs) &
                       (IPG_RFS_RXFIFOOVERRUN | IPG_RFS_RXRUNTFRAME |
                        IPG_RFS_RXALIGNMENTERROR | IPG_RFS_RXFCSERROR |
                        IPG_RFS_RXOVERSIZEDFRAME | IPG_RFS_RXLENGTHERROR)))) {

                        IPG_DEBUG_MSG("Rx error, RFS = %16.16lx\n",
                                      (unsigned long int) rxfd->rfs);

                        /* Increment general receive error statistic. */
                        sp->stats.rx_errors++;

                        /* Increment detailed receive error statistics. */
                        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFIFOOVERRUN) {
                                IPG_DEBUG_MSG("RX FIFO overrun occured.\n");
                                sp->stats.rx_fifo_errors++;
                        }

                        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXRUNTFRAME) {
                                IPG_DEBUG_MSG("RX runt occured.\n");
                                sp->stats.rx_length_errors++;
                        }

                        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXOVERSIZEDFRAME) ;
                        /* Do nothing, error count handled by a IPG
                         * statistic register.
                         */

                        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXALIGNMENTERROR) {
                                IPG_DEBUG_MSG("RX alignment error occured.\n");
                                sp->stats.rx_frame_errors++;
                        }

                        if (le64_to_cpu(rxfd->rfs) & IPG_RFS_RXFCSERROR) ;
                        /* Do nothing, error count handled by a IPG
                         * statistic register.
                         */

                        /* Free the memory associated with the RX
                         * buffer since it is erroneous and we will
                         * not pass it to higher layer processes.
                         */
                        if (skb) {
                                __le64 info = rxfd->frag_info;

                                pci_unmap_single(sp->pdev,
                                        le64_to_cpu(info) & ~IPG_RFI_FRAGLEN,
                                        sp->rx_buf_sz, PCI_DMA_FROMDEVICE);

                                dev_kfree_skb_irq(skb);
                        }
                } else {

                        /* Adjust the new buffer length to accomodate the size
                         * of the received frame.
                         */
                        skb_put(skb, framelen);

                        /* Set the buffer's protocol field to Ethernet. */
                        skb->protocol = eth_type_trans(skb, dev);

                        /* The IPG encountered an error with (or
                         * there were no) IP/TCP/UDP checksums.
                         * This may or may not indicate an invalid
                         * IP/TCP/UDP frame was received. Let the
                         * upper layer decide.
                         */
                        skb->ip_summed = CHECKSUM_NONE;

                        /* Hand off frame for higher layer processing.
                         * The function netif_rx() releases the sk_buff
                         * when processing completes.
                         */
                        netif_rx(skb);

                        /* Record frame receive time (jiffies = Linux
                         * kernel current time stamp).
                         */
                        dev->last_rx = jiffies;
                }

                /* Assure RX buffer is not reused by IPG. */
                sp->RxBuff[entry] = NULL;
        }

        /*
         * If there are more RFDs to proces and the allocated amount of RFD
         * processing time has expired, assert Interrupt Requested to make
         * sure we come back to process the remaining RFDs.
         */
        if (i == IPG_MAXRFDPROCESS_COUNT)
                ipg_w32(ipg_r32(ASIC_CTRL) | IPG_AC_INT_REQUEST, ASIC_CTRL);

#ifdef IPG_DEBUG
        /* Check if the RFD list contained no receive frame data. */
        if (!i)
                sp->EmptyRFDListCount++;
#endif
        while ((le64_to_cpu(rxfd->rfs) & IPG_RFS_RFDDONE) &&
               !((le64_to_cpu(rxfd->rfs) & IPG_RFS_FRAMESTART) &&
                 (le64_to_cpu(rxfd->rfs) & IPG_RFS_FRAMEEND))) {
                unsigned int entry = curr++ % IPG_RFDLIST_LENGTH;

                rxfd = sp->rxd + entry;

                IPG_DEBUG_MSG("Frame requires multiple RFDs.\n");

                /* An unexpected event, additional code needed to handle
                 * properly. So for the time being, just disregard the
                 * frame.
                 */

                /* Free the memory associated with the RX
                 * buffer since it is erroneous and we will
                 * not pass it to higher layer processes.
                 */
                if (sp->RxBuff[entry]) {
                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(rxfd->frag_info) & ~IPG_RFI_FRAGLEN,
                                sp->rx_buf_sz, PCI_DMA_FROMDEVICE);
                        dev_kfree_skb_irq(sp->RxBuff[entry]);
                }

                /* Assure RX buffer is not reused by IPG. */
                sp->RxBuff[entry] = NULL;
        }

        sp->rx_current = curr;

        /* Check to see if there are a minimum number of used
         * RFDs before restoring any (should improve performance.)
         */
        if ((curr - sp->rx_dirty) >= IPG_MINUSEDRFDSTOFREE)
                ipg_nic_rxrestore(dev);

        return 0;
}
#endif

static void ipg_reset_after_host_error(struct work_struct *work)
{
        struct ipg_nic_private *sp =
                container_of(work, struct ipg_nic_private, task.work);
        struct net_device *dev = sp->dev;

        IPG_DDEBUG_MSG("DMACtrl = %8.8x\n", ioread32(sp->ioaddr + IPG_DMACTRL));

        /*
         * Acknowledge HostError interrupt by resetting
         * IPG DMA and HOST.
         */
        ipg_reset(dev, IPG_AC_GLOBAL_RESET | IPG_AC_HOST | IPG_AC_DMA);

        init_rfdlist(dev);
        init_tfdlist(dev);

        if (ipg_io_config(dev) < 0) {
                printk(KERN_INFO "%s: Cannot recover from PCI error.\n",
                       dev->name);
                schedule_delayed_work(&sp->task, HZ);
        }
}

static irqreturn_t ipg_interrupt_handler(int irq, void *dev_inst)
{
        struct net_device *dev = dev_inst;
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int handled = 0;
        u16 status;

        IPG_DEBUG_MSG("_interrupt_handler\n");

#ifdef JUMBO_FRAME
        ipg_nic_rxrestore(dev);
#endif
        spin_lock(&sp->lock);

        /* Get interrupt source information, and acknowledge
         * some (i.e. TxDMAComplete, RxDMAComplete, RxEarly,
         * IntRequested, MacControlFrame, LinkEvent) interrupts
         * if issued. Also, all IPG interrupts are disabled by
         * reading IntStatusAck.
         */
        status = ipg_r16(INT_STATUS_ACK);

        IPG_DEBUG_MSG("IntStatusAck = %4.4x\n", status);

        /* Shared IRQ of remove event. */
        if (!(status & IPG_IS_RSVD_MASK))
                goto out_enable;

        handled = 1;

        if (unlikely(!netif_running(dev)))
                goto out_unlock;

        /* If RFDListEnd interrupt, restore all used RFDs. */
        if (status & IPG_IS_RFD_LIST_END) {
                IPG_DEBUG_MSG("RFDListEnd Interrupt.\n");

                /* The RFD list end indicates an RFD was encountered
                 * with a 0 NextPtr, or with an RFDDone bit set to 1
                 * (indicating the RFD is not read for use by the
                 * IPG.) Try to restore all RFDs.
                 */
                ipg_nic_rxrestore(dev);

#ifdef IPG_DEBUG
                /* Increment the RFDlistendCount counter. */
                sp->RFDlistendCount++;
#endif
        }

        /* If RFDListEnd, RxDMAPriority, RxDMAComplete, or
         * IntRequested interrupt, process received frames. */
        if ((status & IPG_IS_RX_DMA_PRIORITY) ||
            (status & IPG_IS_RFD_LIST_END) ||
            (status & IPG_IS_RX_DMA_COMPLETE) ||
            (status & IPG_IS_INT_REQUESTED)) {
#ifdef IPG_DEBUG
                /* Increment the RFD list checked counter if interrupted
                 * only to check the RFD list. */
                if (status & (~(IPG_IS_RX_DMA_PRIORITY | IPG_IS_RFD_LIST_END |
                                IPG_IS_RX_DMA_COMPLETE | IPG_IS_INT_REQUESTED) &
                               (IPG_IS_HOST_ERROR | IPG_IS_TX_DMA_COMPLETE |
                                IPG_IS_LINK_EVENT | IPG_IS_TX_COMPLETE |
                                IPG_IS_UPDATE_STATS)))
                        sp->RFDListCheckedCount++;
#endif

                ipg_nic_rx(dev);
        }

        /* If TxDMAComplete interrupt, free used TFDs. */
        if (status & IPG_IS_TX_DMA_COMPLETE)
                ipg_nic_txfree(dev);

        /* TxComplete interrupts indicate one of numerous actions.
         * Determine what action to take based on TXSTATUS register.
         */
        if (status & IPG_IS_TX_COMPLETE)
                ipg_nic_txcleanup(dev);

        /* If UpdateStats interrupt, update Linux Ethernet statistics */
        if (status & IPG_IS_UPDATE_STATS)
                ipg_nic_get_stats(dev);

        /* If HostError interrupt, reset IPG. */
        if (status & IPG_IS_HOST_ERROR) {
                IPG_DDEBUG_MSG("HostError Interrupt\n");

                schedule_delayed_work(&sp->task, 0);
        }

        /* If LinkEvent interrupt, resolve autonegotiation. */
        if (status & IPG_IS_LINK_EVENT) {
                if (ipg_config_autoneg(dev) < 0)
                        printk(KERN_INFO "%s: Auto-negotiation error.\n",
                               dev->name);
        }

        /* If MACCtrlFrame interrupt, do nothing. */
        if (status & IPG_IS_MAC_CTRL_FRAME)
                IPG_DEBUG_MSG("MACCtrlFrame interrupt.\n");

        /* If RxComplete interrupt, do nothing. */
        if (status & IPG_IS_RX_COMPLETE)
                IPG_DEBUG_MSG("RxComplete interrupt.\n");

        /* If RxEarly interrupt, do nothing. */
        if (status & IPG_IS_RX_EARLY)
                IPG_DEBUG_MSG("RxEarly interrupt.\n");

out_enable:
        /* Re-enable IPG interrupts. */
        ipg_w16(IPG_IE_TX_DMA_COMPLETE | IPG_IE_RX_DMA_COMPLETE |
                IPG_IE_HOST_ERROR | IPG_IE_INT_REQUESTED | IPG_IE_TX_COMPLETE |
                IPG_IE_LINK_EVENT | IPG_IE_UPDATE_STATS, INT_ENABLE);
out_unlock:
        spin_unlock(&sp->lock);

        return IRQ_RETVAL(handled);
}

static void ipg_rx_clear(struct ipg_nic_private *sp)
{
        unsigned int i;

        for (i = 0; i < IPG_RFDLIST_LENGTH; i++) {
                if (sp->RxBuff[i]) {
                        struct ipg_rx *rxfd = sp->rxd + i;

                        dev_kfree_skb_irq(sp->RxBuff[i]);
                        sp->RxBuff[i] = NULL;
                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(rxfd->frag_info) & ~IPG_RFI_FRAGLEN,
                                sp->rx_buf_sz, PCI_DMA_FROMDEVICE);
                }
        }
}

static void ipg_tx_clear(struct ipg_nic_private *sp)
{
        unsigned int i;

        for (i = 0; i < IPG_TFDLIST_LENGTH; i++) {
                if (sp->TxBuff[i]) {
                        struct ipg_tx *txfd = sp->txd + i;

                        pci_unmap_single(sp->pdev,
                                le64_to_cpu(txfd->frag_info) & ~IPG_TFI_FRAGLEN,
                                sp->TxBuff[i]->len, PCI_DMA_TODEVICE);

                        dev_kfree_skb_irq(sp->TxBuff[i]);

                        sp->TxBuff[i] = NULL;
                }
        }
}

static int ipg_nic_open(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        struct pci_dev *pdev = sp->pdev;
        int rc;

        IPG_DEBUG_MSG("_nic_open\n");

        sp->rx_buf_sz = IPG_RXSUPPORT_SIZE;

        /* Check for interrupt line conflicts, and request interrupt
         * line for IPG.
         *
         * IMPORTANT: Disable IPG interrupts prior to registering
         *            IRQ.
         */
        ipg_w16(0x0000, INT_ENABLE);

        /* Register the interrupt line to be used by the IPG within
         * the Linux system.
         */
        rc = request_irq(pdev->irq, &ipg_interrupt_handler, IRQF_SHARED,
                         dev->name, dev);
        if (rc < 0) {
                printk(KERN_INFO "%s: Error when requesting interrupt.\n",
                       dev->name);
                goto out;
        }

        dev->irq = pdev->irq;

        rc = -ENOMEM;

        sp->rxd = dma_alloc_coherent(&pdev->dev, IPG_RX_RING_BYTES,
                                     &sp->rxd_map, GFP_KERNEL);
        if (!sp->rxd)
                goto err_free_irq_0;

        sp->txd = dma_alloc_coherent(&pdev->dev, IPG_TX_RING_BYTES,
                                     &sp->txd_map, GFP_KERNEL);
        if (!sp->txd)
                goto err_free_rx_1;

        rc = init_rfdlist(dev);
        if (rc < 0) {
                printk(KERN_INFO "%s: Error during configuration.\n",
                       dev->name);
                goto err_free_tx_2;
        }

        init_tfdlist(dev);

        rc = ipg_io_config(dev);
        if (rc < 0) {
                printk(KERN_INFO "%s: Error during configuration.\n",
                       dev->name);
                goto err_release_tfdlist_3;
        }

        /* Resolve autonegotiation. */
        if (ipg_config_autoneg(dev) < 0)
                printk(KERN_INFO "%s: Auto-negotiation error.\n", dev->name);

#ifdef JUMBO_FRAME
        /* initialize JUMBO Frame control variable */
        sp->Jumbo.FoundStart = 0;
        sp->Jumbo.CurrentSize = 0;
        sp->Jumbo.skb = 0;
        dev->mtu = IPG_TXFRAG_SIZE;
#endif

        /* Enable transmit and receive operation of the IPG. */
        ipg_w32((ipg_r32(MAC_CTRL) | IPG_MC_RX_ENABLE | IPG_MC_TX_ENABLE) &
                 IPG_MC_RSVD_MASK, MAC_CTRL);

        netif_start_queue(dev);
out:
        return rc;

err_release_tfdlist_3:
        ipg_tx_clear(sp);
        ipg_rx_clear(sp);
err_free_tx_2:
        dma_free_coherent(&pdev->dev, IPG_TX_RING_BYTES, sp->txd, sp->txd_map);
err_free_rx_1:
        dma_free_coherent(&pdev->dev, IPG_RX_RING_BYTES, sp->rxd, sp->rxd_map);
err_free_irq_0:
        free_irq(pdev->irq, dev);
        goto out;
}

static int ipg_nic_stop(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        struct pci_dev *pdev = sp->pdev;

        IPG_DEBUG_MSG("_nic_stop\n");

        netif_stop_queue(dev);

        IPG_DDEBUG_MSG("RFDlistendCount = %i\n", sp->RFDlistendCount);
        IPG_DDEBUG_MSG("RFDListCheckedCount = %i\n", sp->rxdCheckedCount);
        IPG_DDEBUG_MSG("EmptyRFDListCount = %i\n", sp->EmptyRFDListCount);
        IPG_DUMPTFDLIST(dev);

        do {
                (void) ipg_r16(INT_STATUS_ACK);

                ipg_reset(dev, IPG_AC_GLOBAL_RESET | IPG_AC_HOST | IPG_AC_DMA);

                synchronize_irq(pdev->irq);
        } while (ipg_r16(INT_ENABLE) & IPG_IE_RSVD_MASK);

        ipg_rx_clear(sp);

        ipg_tx_clear(sp);

        pci_free_consistent(pdev, IPG_RX_RING_BYTES, sp->rxd, sp->rxd_map);
        pci_free_consistent(pdev, IPG_TX_RING_BYTES, sp->txd, sp->txd_map);

        free_irq(pdev->irq, dev);

        return 0;
}

static int ipg_nic_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int entry = sp->tx_current % IPG_TFDLIST_LENGTH;
        unsigned long flags;
        struct ipg_tx *txfd;

        IPG_DDEBUG_MSG("_nic_hard_start_xmit\n");

        /* If in 10Mbps mode, stop the transmit queue so
         * no more transmit frames are accepted.
         */
        if (sp->tenmbpsmode)
                netif_stop_queue(dev);

        if (sp->ResetCurrentTFD) {
                sp->ResetCurrentTFD = 0;
                entry = 0;
        }

        txfd = sp->txd + entry;

        sp->TxBuff[entry] = skb;

        /* Clear all TFC fields, except TFDDONE. */
        txfd->tfc = cpu_to_le64(IPG_TFC_TFDDONE);

        /* Specify the TFC field within the TFD. */
        txfd->tfc |= cpu_to_le64(IPG_TFC_WORDALIGNDISABLED |
                (IPG_TFC_FRAMEID & cpu_to_le64(sp->tx_current)) |
                (IPG_TFC_FRAGCOUNT & (1 << 24)));

        /* Request TxComplete interrupts at an interval defined
         * by the constant IPG_FRAMESBETWEENTXCOMPLETES.
         * Request TxComplete interrupt for every frame
         * if in 10Mbps mode to accomodate problem with 10Mbps
         * processing.
         */
        if (sp->tenmbpsmode)
                txfd->tfc |= cpu_to_le64(IPG_TFC_TXINDICATE);
        txfd->tfc |= cpu_to_le64(IPG_TFC_TXDMAINDICATE);
        /* Based on compilation option, determine if FCS is to be
         * appended to transmit frame by IPG.
         */
        if (!(IPG_APPEND_FCS_ON_TX))
                txfd->tfc |= cpu_to_le64(IPG_TFC_FCSAPPENDDISABLE);

        /* Based on compilation option, determine if IP, TCP and/or
         * UDP checksums are to be added to transmit frame by IPG.
         */
        if (IPG_ADD_IPCHECKSUM_ON_TX)
                txfd->tfc |= cpu_to_le64(IPG_TFC_IPCHECKSUMENABLE);

        if (IPG_ADD_TCPCHECKSUM_ON_TX)
                txfd->tfc |= cpu_to_le64(IPG_TFC_TCPCHECKSUMENABLE);

        if (IPG_ADD_UDPCHECKSUM_ON_TX)
                txfd->tfc |= cpu_to_le64(IPG_TFC_UDPCHECKSUMENABLE);

        /* Based on compilation option, determine if VLAN tag info is to be
         * inserted into transmit frame by IPG.
         */
        if (IPG_INSERT_MANUAL_VLAN_TAG) {
                txfd->tfc |= cpu_to_le64(IPG_TFC_VLANTAGINSERT |
                        ((u64) IPG_MANUAL_VLAN_VID << 32) |
                        ((u64) IPG_MANUAL_VLAN_CFI << 44) |
                        ((u64) IPG_MANUAL_VLAN_USERPRIORITY << 45));
        }

        /* The fragment start location within system memory is defined
         * by the sk_buff structure's data field. The physical address
         * of this location within the system's virtual memory space
         * is determined using the IPG_HOST2BUS_MAP function.
         */
        txfd->frag_info = cpu_to_le64(pci_map_single(sp->pdev, skb->data,
                skb->len, PCI_DMA_TODEVICE));

        /* The length of the fragment within system memory is defined by
         * the sk_buff structure's len field.
         */
        txfd->frag_info |= cpu_to_le64(IPG_TFI_FRAGLEN &
                ((u64) (skb->len & 0xffff) << 48));

        /* Clear the TFDDone bit last to indicate the TFD is ready
         * for transfer to the IPG.
         */
        txfd->tfc &= cpu_to_le64(~IPG_TFC_TFDDONE);

        spin_lock_irqsave(&sp->lock, flags);

        sp->tx_current++;

        mmiowb();

        ipg_w32(IPG_DC_TX_DMA_POLL_NOW, DMA_CTRL);

        if (sp->tx_current == (sp->tx_dirty + IPG_TFDLIST_LENGTH))
                netif_stop_queue(dev);

        spin_unlock_irqrestore(&sp->lock, flags);

        return NETDEV_TX_OK;
}

static void ipg_set_phy_default_param(unsigned char rev,
                                      struct net_device *dev, int phy_address)
{
        unsigned short length;
        unsigned char revision;
        unsigned short *phy_param;
        unsigned short address, value;

        phy_param = &DefaultPhyParam[0];
        length = *phy_param & 0x00FF;
        revision = (unsigned char)((*phy_param) >> 8);
        phy_param++;
        while (length != 0) {
                if (rev == revision) {
                        while (length > 1) {
                                address = *phy_param;
                                value = *(phy_param + 1);
                                phy_param += 2;
                                mdio_write(dev, phy_address, address, value);
                                length -= 4;
                        }
                        break;
                } else {
                        phy_param += length / 2;
                        length = *phy_param & 0x00FF;
                        revision = (unsigned char)((*phy_param) >> 8);
                        phy_param++;
                }
        }
}

static int read_eeprom(struct net_device *dev, int eep_addr)
{
        void __iomem *ioaddr = ipg_ioaddr(dev);
        unsigned int i;
        int ret = 0;
        u16 value;

        value = IPG_EC_EEPROM_READOPCODE | (eep_addr & 0xff);
        ipg_w16(value, EEPROM_CTRL);

        for (i = 0; i < 1000; i++) {
                u16 data;

                mdelay(10);
                data = ipg_r16(EEPROM_CTRL);
                if (!(data & IPG_EC_EEPROM_BUSY)) {
                        ret = ipg_r16(EEPROM_DATA);
                        break;
                }
        }
        return ret;
}

static void ipg_init_mii(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        struct mii_if_info *mii_if = &sp->mii_if;
        int phyaddr;

        mii_if->dev          = dev;
        mii_if->mdio_read    = mdio_read;
        mii_if->mdio_write   = mdio_write;
        mii_if->phy_id_mask  = 0x1f;
        mii_if->reg_num_mask = 0x1f;

        mii_if->phy_id = phyaddr = ipg_find_phyaddr(dev);

        if (phyaddr != 0x1f) {
                u16 mii_phyctrl, mii_1000cr;
                u8 revisionid = 0;

                mii_1000cr  = mdio_read(dev, phyaddr, MII_CTRL1000);
                mii_1000cr |= ADVERTISE_1000FULL | ADVERTISE_1000HALF |
                        GMII_PHY_1000BASETCONTROL_PreferMaster;
                mdio_write(dev, phyaddr, MII_CTRL1000, mii_1000cr);

                mii_phyctrl = mdio_read(dev, phyaddr, MII_BMCR);

                /* Set default phyparam */
                pci_read_config_byte(sp->pdev, PCI_REVISION_ID, &revisionid);
                ipg_set_phy_default_param(revisionid, dev, phyaddr);

                /* Reset PHY */
                mii_phyctrl |= BMCR_RESET | BMCR_ANRESTART;
                mdio_write(dev, phyaddr, MII_BMCR, mii_phyctrl);

        }
}

static int ipg_hw_init(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        void __iomem *ioaddr = sp->ioaddr;
        unsigned int i;
        int rc;

        /* Read/Write and Reset EEPROM Value */
        /* Read LED Mode Configuration from EEPROM */
        sp->LED_Mode = read_eeprom(dev, 6);

        /* Reset all functions within the IPG. Do not assert
         * RST_OUT as not compatible with some PHYs.
         */
        rc = ipg_reset(dev, IPG_RESET_MASK);
        if (rc < 0)
                goto out;

        ipg_init_mii(dev);

        /* Read MAC Address from EEPROM */
        for (i = 0; i < 3; i++)
                sp->station_addr[i] = read_eeprom(dev, 16 + i);

        for (i = 0; i < 3; i++)
                ipg_w16(sp->station_addr[i], STATION_ADDRESS_0 + 2*i);

        /* Set station address in ethernet_device structure. */
        dev->dev_addr[0] =  ipg_r16(STATION_ADDRESS_0) & 0x00ff;
        dev->dev_addr[1] = (ipg_r16(STATION_ADDRESS_0) & 0xff00) >> 8;
        dev->dev_addr[2] =  ipg_r16(STATION_ADDRESS_1) & 0x00ff;
        dev->dev_addr[3] = (ipg_r16(STATION_ADDRESS_1) & 0xff00) >> 8;
        dev->dev_addr[4] =  ipg_r16(STATION_ADDRESS_2) & 0x00ff;
        dev->dev_addr[5] = (ipg_r16(STATION_ADDRESS_2) & 0xff00) >> 8;
out:
        return rc;
}

static int ipg_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        int rc;

        mutex_lock(&sp->mii_mutex);
        rc = generic_mii_ioctl(&sp->mii_if, if_mii(ifr), cmd, NULL);
        mutex_unlock(&sp->mii_mutex);

        return rc;
}

static int ipg_nic_change_mtu(struct net_device *dev, int new_mtu)
{
        /* Function to accomodate changes to Maximum Transfer Unit
         * (or MTU) of IPG NIC. Cannot use default function since
         * the default will not allow for MTU > 1500 bytes.
         */

        IPG_DEBUG_MSG("_nic_change_mtu\n");

        /* Check that the new MTU value is between 68 (14 byte header, 46
         * byte payload, 4 byte FCS) and IPG_MAX_RXFRAME_SIZE, which
         * corresponds to the MAXFRAMESIZE register in the IPG.
         */
        if ((new_mtu < 68) || (new_mtu > IPG_MAX_RXFRAME_SIZE))
                return -EINVAL;

        dev->mtu = new_mtu;

        return 0;
}

static int ipg_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        int rc;

        mutex_lock(&sp->mii_mutex);
        rc = mii_ethtool_gset(&sp->mii_if, cmd);
        mutex_unlock(&sp->mii_mutex);

        return rc;
}

static int ipg_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        int rc;

        mutex_lock(&sp->mii_mutex);
        rc = mii_ethtool_sset(&sp->mii_if, cmd);
        mutex_unlock(&sp->mii_mutex);

        return rc;
}

static int ipg_nway_reset(struct net_device *dev)
{
        struct ipg_nic_private *sp = netdev_priv(dev);
        int rc;

        mutex_lock(&sp->mii_mutex);
        rc = mii_nway_restart(&sp->mii_if);
        mutex_unlock(&sp->mii_mutex);

        return rc;
}

static struct ethtool_ops ipg_ethtool_ops = {
        .get_settings = ipg_get_settings,
        .set_settings = ipg_set_settings,
        .nway_reset   = ipg_nway_reset,
};

static void ipg_remove(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct ipg_nic_private *sp = netdev_priv(dev);

        IPG_DEBUG_MSG("_remove\n");

        /* Un-register Ethernet device. */
        unregister_netdev(dev);

        pci_iounmap(pdev, sp->ioaddr);

        pci_release_regions(pdev);

        free_netdev(dev);
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

static int __devinit ipg_probe(struct pci_dev *pdev,
                               const struct pci_device_id *id)
{
        unsigned int i = id->driver_data;
        struct ipg_nic_private *sp;
        struct net_device *dev;
        void __iomem *ioaddr;
        int rc;

        rc = pci_enable_device(pdev);
        if (rc < 0)
                goto out;

        printk(KERN_INFO "%s: %s\n", pci_name(pdev), ipg_brand_name[i]);

        pci_set_master(pdev);

        rc = pci_set_dma_mask(pdev, DMA_40BIT_MASK);
        if (rc < 0) {
                rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
                if (rc < 0) {
                        printk(KERN_ERR "%s: DMA config failed.\n",
                               pci_name(pdev));
                        goto err_disable_0;
                }
        }

        /*
         * Initialize net device.
         */
        dev = alloc_etherdev(sizeof(struct ipg_nic_private));
        if (!dev) {
                printk(KERN_ERR "%s: alloc_etherdev failed\n", pci_name(pdev));
                rc = -ENOMEM;
                goto err_disable_0;
        }

        sp = netdev_priv(dev);
        spin_lock_init(&sp->lock);
        mutex_init(&sp->mii_mutex);

        /* Declare IPG NIC functions for Ethernet device methods.
         */
        dev->open = &ipg_nic_open;
        dev->stop = &ipg_nic_stop;
        dev->hard_start_xmit = &ipg_nic_hard_start_xmit;
        dev->get_stats = &ipg_nic_get_stats;
        dev->set_multicast_list = &ipg_nic_set_multicast_list;
        dev->do_ioctl = ipg_ioctl;
        dev->tx_timeout = ipg_tx_timeout;
        dev->change_mtu = &ipg_nic_change_mtu;

        SET_NETDEV_DEV(dev, &pdev->dev);
        SET_ETHTOOL_OPS(dev, &ipg_ethtool_ops);

        rc = pci_request_regions(pdev, DRV_NAME);
        if (rc)
                goto err_free_dev_1;

        ioaddr = pci_iomap(pdev, 1, pci_resource_len(pdev, 1));
        if (!ioaddr) {
                printk(KERN_ERR "%s cannot map MMIO\n", pci_name(pdev));
                rc = -EIO;
                goto err_release_regions_2;
        }

        /* Save the pointer to the PCI device information. */
        sp->ioaddr = ioaddr;
        sp->pdev = pdev;
        sp->dev = dev;

        INIT_DELAYED_WORK(&sp->task, ipg_reset_after_host_error);

        pci_set_drvdata(pdev, dev);

        rc = ipg_hw_init(dev);
        if (rc < 0)
                goto err_unmap_3;

        rc = register_netdev(dev);
        if (rc < 0)
                goto err_unmap_3;

        printk(KERN_INFO "Ethernet device registered as: %s\n", dev->name);
out:
        return rc;

err_unmap_3:
        pci_iounmap(pdev, ioaddr);
err_release_regions_2:
        pci_release_regions(pdev);
err_free_dev_1:
        free_netdev(dev);
err_disable_0:
        pci_disable_device(pdev);
        goto out;
}

static struct pci_driver ipg_pci_driver = {
        .name           = IPG_DRIVER_NAME,
        .id_table       = ipg_pci_tbl,
        .probe          = ipg_probe,
        .remove         = __devexit_p(ipg_remove),
};

static int __init ipg_init_module(void)
{
        return pci_register_driver(&ipg_pci_driver);
}

static void __exit ipg_exit_module(void)
{
        pci_unregister_driver(&ipg_pci_driver);
}

module_init(ipg_init_module);
module_exit(ipg_exit_module);