skge.c

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/*
 * gPXE driver for Marvell Yukon chipset and SysKonnect Gigabit
 * Ethernet adapters. Derived from Linux skge driver (v1.13), which was
 * based on earlier sk98lin, e100 and FreeBSD if_sk drivers.
 *
 * This driver intentionally does not support all the features of the
 * original driver such as link fail-over and link management because
 * those should be done at higher levels.
 *
 * Copyright (C) 2004, 2005 Stephen Hemminger <shemminger@osdl.org>
 *
 * Modified for gPXE, July 2008 by Michael Decker <mrd999@gmail.com>
 * Tested and Modified in December 2009 by
 *    Thomas Miletich <thomas.miletich@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_ONLY );

#include <stdint.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <gpxe/netdevice.h>
#include <gpxe/ethernet.h>
#include <gpxe/if_ether.h>
#include <gpxe/iobuf.h>
#include <gpxe/malloc.h>
#include <gpxe/pci.h>

#include "skge.h"

static struct pci_device_id skge_id_table[] = {
        PCI_ROM(0x10b7, 0x1700,     "3C940",     "3COM 3C940", 0),
        PCI_ROM(0x10b7, 0x80eb,     "3C940B",    "3COM 3C940", 0),
        PCI_ROM(0x1148, 0x4300,     "GE",        "Syskonnect GE", 0),
        PCI_ROM(0x1148, 0x4320,     "YU",        "Syskonnect YU", 0),
        PCI_ROM(0x1186, 0x4C00,     "DGE510T",   "DLink DGE-510T", 0),
        PCI_ROM(0x1186, 0x4b01,     "DGE530T",   "DLink DGE-530T", 0),
        PCI_ROM(0x11ab, 0x4320,     "id4320",    "Marvell id4320", 0),
        PCI_ROM(0x11ab, 0x5005,     "id5005",    "Marvell id5005", 0), /* Belkin */
        PCI_ROM(0x1371, 0x434e,     "Gigacard",  "CNET Gigacard", 0),
        PCI_ROM(0x1737, 0x1064,     "EG1064",    "Linksys EG1064", 0),
        PCI_ROM(0x1737, 0xffff,     "id_any",    "Linksys [any]", 0)
};

static int skge_up(struct net_device *dev);
static void skge_down(struct net_device *dev);
static void skge_tx_clean(struct net_device *dev);
static int xm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val);
static int gm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val);
static void yukon_init(struct skge_hw *hw, int port);
static void genesis_mac_init(struct skge_hw *hw, int port);
static void genesis_link_up(struct skge_port *skge);

static void skge_phyirq(struct skge_hw *hw);
static void skge_poll(struct net_device *dev);
static int skge_xmit_frame(struct net_device *dev, struct io_buffer *iob);
static void skge_net_irq ( struct net_device *dev, int enable );

static void skge_rx_refill(struct net_device *dev);

static struct net_device_operations skge_operations = {
        .open     = skge_up,
        .close    = skge_down,
        .transmit = skge_xmit_frame,
        .poll     = skge_poll,
        .irq      = skge_net_irq
};

/* Avoid conditionals by using array */
static const int txqaddr[] = { Q_XA1, Q_XA2 };
static const int rxqaddr[] = { Q_R1, Q_R2 };
static const u32 rxirqmask[] = { IS_R1_F, IS_R2_F };
static const u32 txirqmask[] = { IS_XA1_F, IS_XA2_F };
static const u32 napimask[] = { IS_R1_F|IS_XA1_F, IS_R2_F|IS_XA2_F };
static const u32 portmask[] = { IS_PORT_1, IS_PORT_2 };

/* Determine supported/advertised modes based on hardware.
 * Note: ethtool ADVERTISED_xxx == SUPPORTED_xxx
 */
static u32 skge_supported_modes(const struct skge_hw *hw)
{
        u32 supported;

        if (hw->copper) {
                supported = SUPPORTED_10baseT_Half
                        | SUPPORTED_10baseT_Full
                        | SUPPORTED_100baseT_Half
                        | SUPPORTED_100baseT_Full
                        | SUPPORTED_1000baseT_Half
                        | SUPPORTED_1000baseT_Full
                        | SUPPORTED_Autoneg| SUPPORTED_TP;

                if (hw->chip_id == CHIP_ID_GENESIS)
                        supported &= ~(SUPPORTED_10baseT_Half
                                             | SUPPORTED_10baseT_Full
                                             | SUPPORTED_100baseT_Half
                                             | SUPPORTED_100baseT_Full);

                else if (hw->chip_id == CHIP_ID_YUKON)
                        supported &= ~SUPPORTED_1000baseT_Half;
        } else
                supported = SUPPORTED_1000baseT_Full | SUPPORTED_1000baseT_Half
                        | SUPPORTED_FIBRE | SUPPORTED_Autoneg;

        return supported;
}

/* Chip internal frequency for clock calculations */
static inline u32 hwkhz(const struct skge_hw *hw)
{
        return (hw->chip_id == CHIP_ID_GENESIS) ? 53125 : 78125;
}

/* Microseconds to chip HZ */
static inline u32 skge_usecs2clk(const struct skge_hw *hw, u32 usec)
{
        return hwkhz(hw) * usec / 1000;
}

enum led_mode { LED_MODE_OFF, LED_MODE_ON, LED_MODE_TST };
static void skge_led(struct skge_port *skge, enum led_mode mode)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;

        if (hw->chip_id == CHIP_ID_GENESIS) {
                switch (mode) {
                case LED_MODE_OFF:
                        if (hw->phy_type == SK_PHY_BCOM)
                                xm_phy_write(hw, port, PHY_BCOM_P_EXT_CTRL, PHY_B_PEC_LED_OFF);
                        else {
                                skge_write32(hw, SK_REG(port, TX_LED_VAL), 0);
                                skge_write8(hw, SK_REG(port, TX_LED_CTRL), LED_T_OFF);
                        }
                        skge_write8(hw, SK_REG(port, LNK_LED_REG), LINKLED_OFF);
                        skge_write32(hw, SK_REG(port, RX_LED_VAL), 0);
                        skge_write8(hw, SK_REG(port, RX_LED_CTRL), LED_T_OFF);
                        break;

                case LED_MODE_ON:
                        skge_write8(hw, SK_REG(port, LNK_LED_REG), LINKLED_ON);
                        skge_write8(hw, SK_REG(port, LNK_LED_REG), LINKLED_LINKSYNC_ON);

                        skge_write8(hw, SK_REG(port, RX_LED_CTRL), LED_START);
                        skge_write8(hw, SK_REG(port, TX_LED_CTRL), LED_START);

                        break;

                case LED_MODE_TST:
                        skge_write8(hw, SK_REG(port, RX_LED_TST), LED_T_ON);
                        skge_write32(hw, SK_REG(port, RX_LED_VAL), 100);
                        skge_write8(hw, SK_REG(port, RX_LED_CTRL), LED_START);

                        if (hw->phy_type == SK_PHY_BCOM)
                                xm_phy_write(hw, port, PHY_BCOM_P_EXT_CTRL, PHY_B_PEC_LED_ON);
                        else {
                                skge_write8(hw, SK_REG(port, TX_LED_TST), LED_T_ON);
                                skge_write32(hw, SK_REG(port, TX_LED_VAL), 100);
                                skge_write8(hw, SK_REG(port, TX_LED_CTRL), LED_START);
                        }

                }
        } else {
                switch (mode) {
                case LED_MODE_OFF:
                        gm_phy_write(hw, port, PHY_MARV_LED_CTRL, 0);
                        gm_phy_write(hw, port, PHY_MARV_LED_OVER,
                                     PHY_M_LED_MO_DUP(MO_LED_OFF)  |
                                     PHY_M_LED_MO_10(MO_LED_OFF)   |
                                     PHY_M_LED_MO_100(MO_LED_OFF)  |
                                     PHY_M_LED_MO_1000(MO_LED_OFF) |
                                     PHY_M_LED_MO_RX(MO_LED_OFF));
                        break;
                case LED_MODE_ON:
                        gm_phy_write(hw, port, PHY_MARV_LED_CTRL,
                                     PHY_M_LED_PULS_DUR(PULS_170MS) |
                                     PHY_M_LED_BLINK_RT(BLINK_84MS) |
                                     PHY_M_LEDC_TX_CTRL |
                                     PHY_M_LEDC_DP_CTRL);

                        gm_phy_write(hw, port, PHY_MARV_LED_OVER,
                                     PHY_M_LED_MO_RX(MO_LED_OFF) |
                                     (skge->speed == SPEED_100 ?
                                      PHY_M_LED_MO_100(MO_LED_ON) : 0));
                        break;
                case LED_MODE_TST:
                        gm_phy_write(hw, port, PHY_MARV_LED_CTRL, 0);
                        gm_phy_write(hw, port, PHY_MARV_LED_OVER,
                                     PHY_M_LED_MO_DUP(MO_LED_ON)  |
                                     PHY_M_LED_MO_10(MO_LED_ON)   |
                                     PHY_M_LED_MO_100(MO_LED_ON)  |
                                     PHY_M_LED_MO_1000(MO_LED_ON) |
                                     PHY_M_LED_MO_RX(MO_LED_ON));
                }
        }
}

/*
 * I've left in these EEPROM and VPD functions, as someone may desire to
 * integrate them in the future. -mdeck
 *
 * static int skge_get_eeprom_len(struct net_device *dev)
 * {
 *      struct skge_port *skge = netdev_priv(dev);
 *      u32 reg2;
 *
 *      pci_read_config_dword(skge->hw->pdev, PCI_DEV_REG2, &reg2);
 *      return 1 << ( ((reg2 & PCI_VPD_ROM_SZ) >> 14) + 8);
 * }
 *
 * static u32 skge_vpd_read(struct pci_dev *pdev, int cap, u16 offset)
 * {
 *      u32 val;
 *
 *      pci_write_config_word(pdev, cap + PCI_VPD_ADDR, offset);
 *
 *      do {
 *              pci_read_config_word(pdev, cap + PCI_VPD_ADDR, &offset);
 *      } while (!(offset & PCI_VPD_ADDR_F));
 *
 *      pci_read_config_dword(pdev, cap + PCI_VPD_DATA, &val);
 *      return val;
 * }
 *
 * static void skge_vpd_write(struct pci_dev *pdev, int cap, u16 offset, u32 val)
 * {
 *      pci_write_config_dword(pdev, cap + PCI_VPD_DATA, val);
 *      pci_write_config_word(pdev, cap + PCI_VPD_ADDR,
 *                            offset | PCI_VPD_ADDR_F);
 *
 *      do {
 *              pci_read_config_word(pdev, cap + PCI_VPD_ADDR, &offset);
 *      } while (offset & PCI_VPD_ADDR_F);
 * }
 *
 * static int skge_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 *                         u8 *data)
 * {
 *      struct skge_port *skge = netdev_priv(dev);
 *      struct pci_dev *pdev = skge->hw->pdev;
 *      int cap = pci_find_capability(pdev, PCI_CAP_ID_VPD);
 *      int length = eeprom->len;
 *      u16 offset = eeprom->offset;
 *
 *      if (!cap)
 *              return -EINVAL;
 *
 *      eeprom->magic = SKGE_EEPROM_MAGIC;
 *
 *      while (length > 0) {
 *              u32 val = skge_vpd_read(pdev, cap, offset);
 *              int n = min_t(int, length, sizeof(val));
 *
 *              memcpy(data, &val, n);
 *              length -= n;
 *              data += n;
 *              offset += n;
 *      }
 *      return 0;
 * }
 *
 * static int skge_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 *                         u8 *data)
 * {
 *      struct skge_port *skge = netdev_priv(dev);
 *      struct pci_dev *pdev = skge->hw->pdev;
 *      int cap = pci_find_capability(pdev, PCI_CAP_ID_VPD);
 *      int length = eeprom->len;
 *      u16 offset = eeprom->offset;
 *
 *      if (!cap)
 *              return -EINVAL;
 *
 *      if (eeprom->magic != SKGE_EEPROM_MAGIC)
 *              return -EINVAL;
 *
 *      while (length > 0) {
 *              u32 val;
 *              int n = min_t(int, length, sizeof(val));
 *
 *              if (n < sizeof(val))
 *                      val = skge_vpd_read(pdev, cap, offset);
 *              memcpy(&val, data, n);
 *
 *              skge_vpd_write(pdev, cap, offset, val);
 *
 *              length -= n;
 *              data += n;
 *              offset += n;
 *      }
 *      return 0;
 * }
 */

/*
 * Allocate ring elements and chain them together
 * One-to-one association of board descriptors with ring elements
 */
static int skge_ring_alloc(struct skge_ring *ring, void *vaddr, u32 base,
                           size_t num)
{
        struct skge_tx_desc *d;
        struct skge_element *e;
        unsigned int i;

        ring->start = zalloc(num*sizeof(*e));
        if (!ring->start)
                return -ENOMEM;

        for (i = 0, e = ring->start, d = vaddr; i < num; i++, e++, d++) {
                e->desc = d;
                if (i == num - 1) {
                        e->next = ring->start;
                        d->next_offset = base;
                } else {
                        e->next = e + 1;
                        d->next_offset = base + (i+1) * sizeof(*d);
                }
        }
        ring->to_use = ring->to_clean = ring->start;

        return 0;
}

/* Allocate and setup a new buffer for receiving */
static void skge_rx_setup(struct skge_port *skge __unused,
                          struct skge_element *e,
                          struct io_buffer *iob, unsigned int bufsize)
{
        struct skge_rx_desc *rd = e->desc;
        u64 map;

        map = ( iob != NULL ) ? virt_to_bus(iob->data) : 0;

        rd->dma_lo = map;
        rd->dma_hi = map >> 32;
        e->iob = iob;
        rd->csum1_start = ETH_HLEN;
        rd->csum2_start = ETH_HLEN;
        rd->csum1 = 0;
        rd->csum2 = 0;

        wmb();

        rd->control = BMU_OWN | BMU_STF | BMU_IRQ_EOF | BMU_TCP_CHECK | bufsize;
}

/* Resume receiving using existing skb,
 * Note: DMA address is not changed by chip.
 *       MTU not changed while receiver active.
 */
static inline void skge_rx_reuse(struct skge_element *e, unsigned int size)
{
        struct skge_rx_desc *rd = e->desc;

        rd->csum2 = 0;
        rd->csum2_start = ETH_HLEN;

        wmb();

        rd->control = BMU_OWN | BMU_STF | BMU_IRQ_EOF | BMU_TCP_CHECK | size;
}


/* Free all  buffers in receive ring, assumes receiver stopped */
static void skge_rx_clean(struct skge_port *skge)
{
        struct skge_ring *ring = &skge->rx_ring;
        struct skge_element *e;

        e = ring->start;
        do {
                struct skge_rx_desc *rd = e->desc;
                rd->control = 0;
                if (e->iob) {
                        free_iob(e->iob);
                        e->iob = NULL;
                }
        } while ((e = e->next) != ring->start);
}

static void skge_link_up(struct skge_port *skge)
{
        skge_write8(skge->hw, SK_REG(skge->port, LNK_LED_REG),
                    LED_BLK_OFF|LED_SYNC_OFF|LED_ON);

        netdev_link_up(skge->netdev);

        DBG2(PFX "%s: Link is up at %d Mbps, %s duplex\n",
             skge->netdev->name, skge->speed,
             skge->duplex == DUPLEX_FULL ? "full" : "half");
}

static void skge_link_down(struct skge_port *skge)
{
        skge_write8(skge->hw, SK_REG(skge->port, LNK_LED_REG), LED_OFF);
        netdev_link_down(skge->netdev);

        DBG2(PFX "%s: Link is down.\n", skge->netdev->name);
}


static void xm_link_down(struct skge_hw *hw, int port)
{
        struct net_device *dev = hw->dev[port];
        struct skge_port *skge = netdev_priv(dev);

        xm_write16(hw, port, XM_IMSK, XM_IMSK_DISABLE);

        if (netdev_link_ok(dev))
                skge_link_down(skge);
}

static int __xm_phy_read(struct skge_hw *hw, int port, u16 reg, u16 *val)
{
        int i;

        xm_write16(hw, port, XM_PHY_ADDR, reg | hw->phy_addr);
        *val = xm_read16(hw, port, XM_PHY_DATA);

        if (hw->phy_type == SK_PHY_XMAC)
                goto ready;

        for (i = 0; i < PHY_RETRIES; i++) {
                if (xm_read16(hw, port, XM_MMU_CMD) & XM_MMU_PHY_RDY)
                        goto ready;
                udelay(1);
        }

        return -ETIMEDOUT;
 ready:
        *val = xm_read16(hw, port, XM_PHY_DATA);

        return 0;
}

static u16 xm_phy_read(struct skge_hw *hw, int port, u16 reg)
{
        u16 v = 0;
        if (__xm_phy_read(hw, port, reg, &v))
                DBG(PFX "%s: phy read timed out\n",
                       hw->dev[port]->name);
        return v;
}

static int xm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val)
{
        int i;

        xm_write16(hw, port, XM_PHY_ADDR, reg | hw->phy_addr);
        for (i = 0; i < PHY_RETRIES; i++) {
                if (!(xm_read16(hw, port, XM_MMU_CMD) & XM_MMU_PHY_BUSY))
                        goto ready;
                udelay(1);
        }
        return -EIO;

 ready:
        xm_write16(hw, port, XM_PHY_DATA, val);
        for (i = 0; i < PHY_RETRIES; i++) {
                if (!(xm_read16(hw, port, XM_MMU_CMD) & XM_MMU_PHY_BUSY))
                        return 0;
                udelay(1);
        }
        return -ETIMEDOUT;
}

static void genesis_init(struct skge_hw *hw)
{
        /* set blink source counter */
        skge_write32(hw, B2_BSC_INI, (SK_BLK_DUR * SK_FACT_53) / 100);
        skge_write8(hw, B2_BSC_CTRL, BSC_START);

        /* configure mac arbiter */
        skge_write16(hw, B3_MA_TO_CTRL, MA_RST_CLR);

        /* configure mac arbiter timeout values */
        skge_write8(hw, B3_MA_TOINI_RX1, SK_MAC_TO_53);
        skge_write8(hw, B3_MA_TOINI_RX2, SK_MAC_TO_53);
        skge_write8(hw, B3_MA_TOINI_TX1, SK_MAC_TO_53);
        skge_write8(hw, B3_MA_TOINI_TX2, SK_MAC_TO_53);

        skge_write8(hw, B3_MA_RCINI_RX1, 0);
        skge_write8(hw, B3_MA_RCINI_RX2, 0);
        skge_write8(hw, B3_MA_RCINI_TX1, 0);
        skge_write8(hw, B3_MA_RCINI_TX2, 0);

        /* configure packet arbiter timeout */
        skge_write16(hw, B3_PA_CTRL, PA_RST_CLR);
        skge_write16(hw, B3_PA_TOINI_RX1, SK_PKT_TO_MAX);
        skge_write16(hw, B3_PA_TOINI_TX1, SK_PKT_TO_MAX);
        skge_write16(hw, B3_PA_TOINI_RX2, SK_PKT_TO_MAX);
        skge_write16(hw, B3_PA_TOINI_TX2, SK_PKT_TO_MAX);
}

static void genesis_reset(struct skge_hw *hw, int port)
{
        const u8 zero[8]  = { 0 };
        u32 reg;

        skge_write8(hw, SK_REG(port, GMAC_IRQ_MSK), 0);

        /* reset the statistics module */
        xm_write32(hw, port, XM_GP_PORT, XM_GP_RES_STAT);
        xm_write16(hw, port, XM_IMSK, XM_IMSK_DISABLE);
        xm_write32(hw, port, XM_MODE, 0);               /* clear Mode Reg */
        xm_write16(hw, port, XM_TX_CMD, 0);     /* reset TX CMD Reg */
        xm_write16(hw, port, XM_RX_CMD, 0);     /* reset RX CMD Reg */

        /* disable Broadcom PHY IRQ */
        if (hw->phy_type == SK_PHY_BCOM)
                xm_write16(hw, port, PHY_BCOM_INT_MASK, 0xffff);

        xm_outhash(hw, port, XM_HSM, zero);

        /* Flush TX and RX fifo */
        reg = xm_read32(hw, port, XM_MODE);
        xm_write32(hw, port, XM_MODE, reg | XM_MD_FTF);
        xm_write32(hw, port, XM_MODE, reg | XM_MD_FRF);
}


/* Convert mode to MII values  */
static const u16 phy_pause_map[] = {
        [FLOW_MODE_NONE] =      0,
        [FLOW_MODE_LOC_SEND] =  PHY_AN_PAUSE_ASYM,
        [FLOW_MODE_SYMMETRIC] = PHY_AN_PAUSE_CAP,
        [FLOW_MODE_SYM_OR_REM]  = PHY_AN_PAUSE_CAP | PHY_AN_PAUSE_ASYM,
};

/* special defines for FIBER (88E1011S only) */
static const u16 fiber_pause_map[] = {
        [FLOW_MODE_NONE]        = PHY_X_P_NO_PAUSE,
        [FLOW_MODE_LOC_SEND]    = PHY_X_P_ASYM_MD,
        [FLOW_MODE_SYMMETRIC]   = PHY_X_P_SYM_MD,
        [FLOW_MODE_SYM_OR_REM]  = PHY_X_P_BOTH_MD,
};


/* Check status of Broadcom phy link */
static void bcom_check_link(struct skge_hw *hw, int port)
{
        struct net_device *dev = hw->dev[port];
        struct skge_port *skge = netdev_priv(dev);
        u16 status;

        /* read twice because of latch */
        xm_phy_read(hw, port, PHY_BCOM_STAT);
        status = xm_phy_read(hw, port, PHY_BCOM_STAT);

        if ((status & PHY_ST_LSYNC) == 0) {
                xm_link_down(hw, port);
                return;
        }

        if (skge->autoneg == AUTONEG_ENABLE) {
                u16 lpa, aux;

                if (!(status & PHY_ST_AN_OVER))
                        return;

                lpa = xm_phy_read(hw, port, PHY_XMAC_AUNE_LP);
                if (lpa & PHY_B_AN_RF) {
                        DBG(PFX "%s: remote fault\n",
                               dev->name);
                        return;
                }

                aux = xm_phy_read(hw, port, PHY_BCOM_AUX_STAT);

                /* Check Duplex mismatch */
                switch (aux & PHY_B_AS_AN_RES_MSK) {
                case PHY_B_RES_1000FD:
                        skge->duplex = DUPLEX_FULL;
                        break;
                case PHY_B_RES_1000HD:
                        skge->duplex = DUPLEX_HALF;
                        break;
                default:
                        DBG(PFX "%s: duplex mismatch\n",
                               dev->name);
                        return;
                }

                /* We are using IEEE 802.3z/D5.0 Table 37-4 */
                switch (aux & PHY_B_AS_PAUSE_MSK) {
                case PHY_B_AS_PAUSE_MSK:
                        skge->flow_status = FLOW_STAT_SYMMETRIC;
                        break;
                case PHY_B_AS_PRR:
                        skge->flow_status = FLOW_STAT_REM_SEND;
                        break;
                case PHY_B_AS_PRT:
                        skge->flow_status = FLOW_STAT_LOC_SEND;
                        break;
                default:
                        skge->flow_status = FLOW_STAT_NONE;
                }
                skge->speed = SPEED_1000;
        }

        if (!netdev_link_ok(dev))
                genesis_link_up(skge);
}

/* Broadcom 5400 only supports giagabit! SysKonnect did not put an additional
 * Phy on for 100 or 10Mbit operation
 */
static void bcom_phy_init(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        unsigned int i;
        u16 id1, r, ext, ctl;

        /* magic workaround patterns for Broadcom */
        static const struct {
                u16 reg;
                u16 val;
        } A1hack[] = {
                { 0x18, 0x0c20 }, { 0x17, 0x0012 }, { 0x15, 0x1104 },
                { 0x17, 0x0013 }, { 0x15, 0x0404 }, { 0x17, 0x8006 },
                { 0x15, 0x0132 }, { 0x17, 0x8006 }, { 0x15, 0x0232 },
                { 0x17, 0x800D }, { 0x15, 0x000F }, { 0x18, 0x0420 },
        }, C0hack[] = {
                { 0x18, 0x0c20 }, { 0x17, 0x0012 }, { 0x15, 0x1204 },
                { 0x17, 0x0013 }, { 0x15, 0x0A04 }, { 0x18, 0x0420 },
        };

        /* read Id from external PHY (all have the same address) */
        id1 = xm_phy_read(hw, port, PHY_XMAC_ID1);

        /* Optimize MDIO transfer by suppressing preamble. */
        r = xm_read16(hw, port, XM_MMU_CMD);
        r |=  XM_MMU_NO_PRE;
        xm_write16(hw, port, XM_MMU_CMD,r);

        switch (id1) {
        case PHY_BCOM_ID1_C0:
                /*
                 * Workaround BCOM Errata for the C0 type.
                 * Write magic patterns to reserved registers.
                 */
                for (i = 0; i < ARRAY_SIZE(C0hack); i++)
                        xm_phy_write(hw, port,
                                     C0hack[i].reg, C0hack[i].val);

                break;
        case PHY_BCOM_ID1_A1:
                /*
                 * Workaround BCOM Errata for the A1 type.
                 * Write magic patterns to reserved registers.
                 */
                for (i = 0; i < ARRAY_SIZE(A1hack); i++)
                        xm_phy_write(hw, port,
                                     A1hack[i].reg, A1hack[i].val);
                break;
        }

        /*
         * Workaround BCOM Errata (#10523) for all BCom PHYs.
         * Disable Power Management after reset.
         */
        r = xm_phy_read(hw, port, PHY_BCOM_AUX_CTRL);
        r |= PHY_B_AC_DIS_PM;
        xm_phy_write(hw, port, PHY_BCOM_AUX_CTRL, r);

        /* Dummy read */
        xm_read16(hw, port, XM_ISRC);

        ext = PHY_B_PEC_EN_LTR; /* enable tx led */
        ctl = PHY_CT_SP1000;    /* always 1000mbit */

        if (skge->autoneg == AUTONEG_ENABLE) {
                /*
                 * Workaround BCOM Errata #1 for the C5 type.
                 * 1000Base-T Link Acquisition Failure in Slave Mode
                 * Set Repeater/DTE bit 10 of the 1000Base-T Control Register
                 */
                u16 adv = PHY_B_1000C_RD;
                if (skge->advertising & ADVERTISED_1000baseT_Half)
                        adv |= PHY_B_1000C_AHD;
                if (skge->advertising & ADVERTISED_1000baseT_Full)
                        adv |= PHY_B_1000C_AFD;
                xm_phy_write(hw, port, PHY_BCOM_1000T_CTRL, adv);

                ctl |= PHY_CT_ANE | PHY_CT_RE_CFG;
        } else {
                if (skge->duplex == DUPLEX_FULL)
                        ctl |= PHY_CT_DUP_MD;
                /* Force to slave */
                xm_phy_write(hw, port, PHY_BCOM_1000T_CTRL, PHY_B_1000C_MSE);
        }

        /* Set autonegotiation pause parameters */
        xm_phy_write(hw, port, PHY_BCOM_AUNE_ADV,
                     phy_pause_map[skge->flow_control] | PHY_AN_CSMA);

        xm_phy_write(hw, port, PHY_BCOM_P_EXT_CTRL, ext);
        xm_phy_write(hw, port, PHY_BCOM_CTRL, ctl);

        /* Use link status change interrupt */
        xm_phy_write(hw, port, PHY_BCOM_INT_MASK, PHY_B_DEF_MSK);
}

static void xm_phy_init(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 ctrl = 0;

        if (skge->autoneg == AUTONEG_ENABLE) {
                if (skge->advertising & ADVERTISED_1000baseT_Half)
                        ctrl |= PHY_X_AN_HD;
                if (skge->advertising & ADVERTISED_1000baseT_Full)
                        ctrl |= PHY_X_AN_FD;

                ctrl |= fiber_pause_map[skge->flow_control];

                xm_phy_write(hw, port, PHY_XMAC_AUNE_ADV, ctrl);

                /* Restart Auto-negotiation */
                ctrl = PHY_CT_ANE | PHY_CT_RE_CFG;
        } else {
                /* Set DuplexMode in Config register */
                if (skge->duplex == DUPLEX_FULL)
                        ctrl |= PHY_CT_DUP_MD;
                /*
                 * Do NOT enable Auto-negotiation here. This would hold
                 * the link down because no IDLEs are transmitted
                 */
        }

        xm_phy_write(hw, port, PHY_XMAC_CTRL, ctrl);

        /* Poll PHY for status changes */
        skge->use_xm_link_timer = 1;
}

static int xm_check_link(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 status;

        /* read twice because of latch */
        xm_phy_read(hw, port, PHY_XMAC_STAT);
        status = xm_phy_read(hw, port, PHY_XMAC_STAT);

        if ((status & PHY_ST_LSYNC) == 0) {
                xm_link_down(hw, port);
                return 0;
        }

        if (skge->autoneg == AUTONEG_ENABLE) {
                u16 lpa, res;

                if (!(status & PHY_ST_AN_OVER))
                        return 0;

                lpa = xm_phy_read(hw, port, PHY_XMAC_AUNE_LP);
                if (lpa & PHY_B_AN_RF) {
                        DBG(PFX "%s: remote fault\n",
                               dev->name);
                        return 0;
                }

                res = xm_phy_read(hw, port, PHY_XMAC_RES_ABI);

                /* Check Duplex mismatch */
                switch (res & (PHY_X_RS_HD | PHY_X_RS_FD)) {
                case PHY_X_RS_FD:
                        skge->duplex = DUPLEX_FULL;
                        break;
                case PHY_X_RS_HD:
                        skge->duplex = DUPLEX_HALF;
                        break;
                default:
                        DBG(PFX "%s: duplex mismatch\n",
                               dev->name);
                        return 0;
                }

                /* We are using IEEE 802.3z/D5.0 Table 37-4 */
                if ((skge->flow_control == FLOW_MODE_SYMMETRIC ||
                     skge->flow_control == FLOW_MODE_SYM_OR_REM) &&
                    (lpa & PHY_X_P_SYM_MD))
                        skge->flow_status = FLOW_STAT_SYMMETRIC;
                else if (skge->flow_control == FLOW_MODE_SYM_OR_REM &&
                         (lpa & PHY_X_RS_PAUSE) == PHY_X_P_ASYM_MD)
                        /* Enable PAUSE receive, disable PAUSE transmit */
                        skge->flow_status  = FLOW_STAT_REM_SEND;
                else if (skge->flow_control == FLOW_MODE_LOC_SEND &&
                         (lpa & PHY_X_RS_PAUSE) == PHY_X_P_BOTH_MD)
                        /* Disable PAUSE receive, enable PAUSE transmit */
                        skge->flow_status = FLOW_STAT_LOC_SEND;
                else
                        skge->flow_status = FLOW_STAT_NONE;

                skge->speed = SPEED_1000;
        }

        if (!netdev_link_ok(dev))
                genesis_link_up(skge);
        return 1;
}

/* Poll to check for link coming up.
 *
 * Since internal PHY is wired to a level triggered pin, can't
 * get an interrupt when carrier is detected, need to poll for
 * link coming up.
 */
static void xm_link_timer(struct skge_port *skge)
{
        struct net_device *dev = skge->netdev;
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        int i;

        /*
         * Verify that the link by checking GPIO register three times.
         * This pin has the signal from the link_sync pin connected to it.
         */
        for (i = 0; i < 3; i++) {
                if (xm_read16(hw, port, XM_GP_PORT) & XM_GP_INP_ASS)
                        return;
        }

        /* Re-enable interrupt to detect link down */
        if (xm_check_link(dev)) {
                u16 msk = xm_read16(hw, port, XM_IMSK);
                msk &= ~XM_IS_INP_ASS;
                xm_write16(hw, port, XM_IMSK, msk);
                xm_read16(hw, port, XM_ISRC);
        }
}

static void genesis_mac_init(struct skge_hw *hw, int port)
{
        struct net_device *dev = hw->dev[port];
        struct skge_port *skge = netdev_priv(dev);
        int i;
        u32 r;
        const u8 zero[6]  = { 0 };

        for (i = 0; i < 10; i++) {
                skge_write16(hw, SK_REG(port, TX_MFF_CTRL1),
                             MFF_SET_MAC_RST);
                if (skge_read16(hw, SK_REG(port, TX_MFF_CTRL1)) & MFF_SET_MAC_RST)
                        goto reset_ok;
                udelay(1);
        }

        DBG(PFX "%s: genesis reset failed\n", dev->name);

 reset_ok:
        /* Unreset the XMAC. */
        skge_write16(hw, SK_REG(port, TX_MFF_CTRL1), MFF_CLR_MAC_RST);

        /*
         * Perform additional initialization for external PHYs,
         * namely for the 1000baseTX cards that use the XMAC's
         * GMII mode.
         */
        if (hw->phy_type != SK_PHY_XMAC) {
                /* Take external Phy out of reset */
                r = skge_read32(hw, B2_GP_IO);
                if (port == 0)
                        r |= GP_DIR_0|GP_IO_0;
                else
                        r |= GP_DIR_2|GP_IO_2;

                skge_write32(hw, B2_GP_IO, r);

                /* Enable GMII interface */
                xm_write16(hw, port, XM_HW_CFG, XM_HW_GMII_MD);
        }


        switch(hw->phy_type) {
        case SK_PHY_XMAC:
                xm_phy_init(skge);
                break;
        case SK_PHY_BCOM:
                bcom_phy_init(skge);
                bcom_check_link(hw, port);
        }

        /* Set Station Address */
        xm_outaddr(hw, port, XM_SA, dev->ll_addr);

        /* We don't use match addresses so clear */
        for (i = 1; i < 16; i++)
                xm_outaddr(hw, port, XM_EXM(i), zero);

        /* Clear MIB counters */
        xm_write16(hw, port, XM_STAT_CMD,
                        XM_SC_CLR_RXC | XM_SC_CLR_TXC);
        /* Clear two times according to Errata #3 */
        xm_write16(hw, port, XM_STAT_CMD,
                        XM_SC_CLR_RXC | XM_SC_CLR_TXC);

        /* configure Rx High Water Mark (XM_RX_HI_WM) */
        xm_write16(hw, port, XM_RX_HI_WM, 1450);

        /* We don't need the FCS appended to the packet. */
        r = XM_RX_LENERR_OK | XM_RX_STRIP_FCS;

        if (skge->duplex == DUPLEX_HALF) {
                /*
                 * If in manual half duplex mode the other side might be in
                 * full duplex mode, so ignore if a carrier extension is not seen
                 * on frames received
                 */
                r |= XM_RX_DIS_CEXT;
        }
        xm_write16(hw, port, XM_RX_CMD, r);

        /* We want short frames padded to 60 bytes. */
        xm_write16(hw, port, XM_TX_CMD, XM_TX_AUTO_PAD);

        xm_write16(hw, port, XM_TX_THR, 512);

        /*
         * Enable the reception of all error frames. This is is
         * a necessary evil due to the design of the XMAC. The
         * XMAC's receive FIFO is only 8K in size, however jumbo
         * frames can be up to 9000 bytes in length. When bad
         * frame filtering is enabled, the XMAC's RX FIFO operates
         * in 'store and forward' mode. For this to work, the
         * entire frame has to fit into the FIFO, but that means
         * that jumbo frames larger than 8192 bytes will be
         * truncated. Disabling all bad frame filtering causes
         * the RX FIFO to operate in streaming mode, in which
         * case the XMAC will start transferring frames out of the
         * RX FIFO as soon as the FIFO threshold is reached.
         */
        xm_write32(hw, port, XM_MODE, XM_DEF_MODE);


        /*
         * Initialize the Receive Counter Event Mask (XM_RX_EV_MSK)
         *      - Enable all bits excepting 'Octets Rx OK Low CntOv'
         *        and 'Octets Rx OK Hi Cnt Ov'.
         */
        xm_write32(hw, port, XM_RX_EV_MSK, XMR_DEF_MSK);

        /*
         * Initialize the Transmit Counter Event Mask (XM_TX_EV_MSK)
         *      - Enable all bits excepting 'Octets Tx OK Low CntOv'
         *        and 'Octets Tx OK Hi Cnt Ov'.
         */
        xm_write32(hw, port, XM_TX_EV_MSK, XMT_DEF_MSK);

        /* Configure MAC arbiter */
        skge_write16(hw, B3_MA_TO_CTRL, MA_RST_CLR);

        /* configure timeout values */
        skge_write8(hw, B3_MA_TOINI_RX1, 72);
        skge_write8(hw, B3_MA_TOINI_RX2, 72);
        skge_write8(hw, B3_MA_TOINI_TX1, 72);
        skge_write8(hw, B3_MA_TOINI_TX2, 72);

        skge_write8(hw, B3_MA_RCINI_RX1, 0);
        skge_write8(hw, B3_MA_RCINI_RX2, 0);
        skge_write8(hw, B3_MA_RCINI_TX1, 0);
        skge_write8(hw, B3_MA_RCINI_TX2, 0);

        /* Configure Rx MAC FIFO */
        skge_write8(hw, SK_REG(port, RX_MFF_CTRL2), MFF_RST_CLR);
        skge_write16(hw, SK_REG(port, RX_MFF_CTRL1), MFF_ENA_TIM_PAT);
        skge_write8(hw, SK_REG(port, RX_MFF_CTRL2), MFF_ENA_OP_MD);

        /* Configure Tx MAC FIFO */
        skge_write8(hw, SK_REG(port, TX_MFF_CTRL2), MFF_RST_CLR);
        skge_write16(hw, SK_REG(port, TX_MFF_CTRL1), MFF_TX_CTRL_DEF);
        skge_write8(hw, SK_REG(port, TX_MFF_CTRL2), MFF_ENA_OP_MD);

        /* enable timeout timers */
        skge_write16(hw, B3_PA_CTRL,
                     (port == 0) ? PA_ENA_TO_TX1 : PA_ENA_TO_TX2);
}

static void genesis_stop(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        unsigned retries = 1000;
        u16 cmd;

        /* Disable Tx and Rx */
        cmd = xm_read16(hw, port, XM_MMU_CMD);
        cmd &= ~(XM_MMU_ENA_RX | XM_MMU_ENA_TX);
        xm_write16(hw, port, XM_MMU_CMD, cmd);

        genesis_reset(hw, port);

        /* Clear Tx packet arbiter timeout IRQ */
        skge_write16(hw, B3_PA_CTRL,
                     port == 0 ? PA_CLR_TO_TX1 : PA_CLR_TO_TX2);

        /* Reset the MAC */
        skge_write16(hw, SK_REG(port, TX_MFF_CTRL1), MFF_CLR_MAC_RST);
        do {
                skge_write16(hw, SK_REG(port, TX_MFF_CTRL1), MFF_SET_MAC_RST);
                if (!(skge_read16(hw, SK_REG(port, TX_MFF_CTRL1)) & MFF_SET_MAC_RST))
                        break;
        } while (--retries > 0);

        /* For external PHYs there must be special handling */
        if (hw->phy_type != SK_PHY_XMAC) {
                u32 reg = skge_read32(hw, B2_GP_IO);
                if (port == 0) {
                        reg |= GP_DIR_0;
                        reg &= ~GP_IO_0;
                } else {
                        reg |= GP_DIR_2;
                        reg &= ~GP_IO_2;
                }
                skge_write32(hw, B2_GP_IO, reg);
                skge_read32(hw, B2_GP_IO);
        }

        xm_write16(hw, port, XM_MMU_CMD,
                        xm_read16(hw, port, XM_MMU_CMD)
                        & ~(XM_MMU_ENA_RX | XM_MMU_ENA_TX));

        xm_read16(hw, port, XM_MMU_CMD);
}

static void genesis_link_up(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 cmd, msk;
        u32 mode;

        cmd = xm_read16(hw, port, XM_MMU_CMD);

        /*
         * enabling pause frame reception is required for 1000BT
         * because the XMAC is not reset if the link is going down
         */
        if (skge->flow_status == FLOW_STAT_NONE ||
            skge->flow_status == FLOW_STAT_LOC_SEND)
                /* Disable Pause Frame Reception */
                cmd |= XM_MMU_IGN_PF;
        else
                /* Enable Pause Frame Reception */
                cmd &= ~XM_MMU_IGN_PF;

        xm_write16(hw, port, XM_MMU_CMD, cmd);

        mode = xm_read32(hw, port, XM_MODE);
        if (skge->flow_status== FLOW_STAT_SYMMETRIC ||
            skge->flow_status == FLOW_STAT_LOC_SEND) {
                /*
                 * Configure Pause Frame Generation
                 * Use internal and external Pause Frame Generation.
                 * Sending pause frames is edge triggered.
                 * Send a Pause frame with the maximum pause time if
                 * internal oder external FIFO full condition occurs.
                 * Send a zero pause time frame to re-start transmission.
                 */
                /* XM_PAUSE_DA = '010000C28001' (default) */
                /* XM_MAC_PTIME = 0xffff (maximum) */
                /* remember this value is defined in big endian (!) */
                xm_write16(hw, port, XM_MAC_PTIME, 0xffff);

                mode |= XM_PAUSE_MODE;
                skge_write16(hw, SK_REG(port, RX_MFF_CTRL1), MFF_ENA_PAUSE);
        } else {
                /*
                 * disable pause frame generation is required for 1000BT
                 * because the XMAC is not reset if the link is going down
                 */
                /* Disable Pause Mode in Mode Register */
                mode &= ~XM_PAUSE_MODE;

                skge_write16(hw, SK_REG(port, RX_MFF_CTRL1), MFF_DIS_PAUSE);
        }

        xm_write32(hw, port, XM_MODE, mode);

        /* Turn on detection of Tx underrun */
        msk = xm_read16(hw, port, XM_IMSK);
        msk &= ~XM_IS_TXF_UR;
        xm_write16(hw, port, XM_IMSK, msk);

        xm_read16(hw, port, XM_ISRC);

        /* get MMU Command Reg. */
        cmd = xm_read16(hw, port, XM_MMU_CMD);
        if (hw->phy_type != SK_PHY_XMAC && skge->duplex == DUPLEX_FULL)
                cmd |= XM_MMU_GMII_FD;

        /*
         * Workaround BCOM Errata (#10523) for all BCom Phys
         * Enable Power Management after link up
         */
        if (hw->phy_type == SK_PHY_BCOM) {
                xm_phy_write(hw, port, PHY_BCOM_AUX_CTRL,
                             xm_phy_read(hw, port, PHY_BCOM_AUX_CTRL)
                             & ~PHY_B_AC_DIS_PM);
                xm_phy_write(hw, port, PHY_BCOM_INT_MASK, PHY_B_DEF_MSK);
        }

        /* enable Rx/Tx */
        xm_write16(hw, port, XM_MMU_CMD,
                        cmd | XM_MMU_ENA_RX | XM_MMU_ENA_TX);
        skge_link_up(skge);
}


static inline void bcom_phy_intr(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 isrc;

        isrc = xm_phy_read(hw, port, PHY_BCOM_INT_STAT);
        DBGIO(PFX "%s: phy interrupt status 0x%x\n",
             skge->netdev->name, isrc);

        if (isrc & PHY_B_IS_PSE)
                DBG(PFX "%s: uncorrectable pair swap error\n",
                    hw->dev[port]->name);

        /* Workaround BCom Errata:
         *      enable and disable loopback mode if "NO HCD" occurs.
         */
        if (isrc & PHY_B_IS_NO_HDCL) {
                u16 ctrl = xm_phy_read(hw, port, PHY_BCOM_CTRL);
                xm_phy_write(hw, port, PHY_BCOM_CTRL,
                                  ctrl | PHY_CT_LOOP);
                xm_phy_write(hw, port, PHY_BCOM_CTRL,
                                  ctrl & ~PHY_CT_LOOP);
        }

        if (isrc & (PHY_B_IS_AN_PR | PHY_B_IS_LST_CHANGE))
                bcom_check_link(hw, port);

}

static int gm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val)
{
        int i;

        gma_write16(hw, port, GM_SMI_DATA, val);
        gma_write16(hw, port, GM_SMI_CTRL,
                         GM_SMI_CT_PHY_AD(hw->phy_addr) | GM_SMI_CT_REG_AD(reg));
        for (i = 0; i < PHY_RETRIES; i++) {
                udelay(1);

                if (!(gma_read16(hw, port, GM_SMI_CTRL) & GM_SMI_CT_BUSY))
                        return 0;
        }

        DBG(PFX "%s: phy write timeout port %x reg %x val %x\n",
            hw->dev[port]->name,
            port, reg, val);
        return -EIO;
}

static int __gm_phy_read(struct skge_hw *hw, int port, u16 reg, u16 *val)
{
        int i;

        gma_write16(hw, port, GM_SMI_CTRL,
                         GM_SMI_CT_PHY_AD(hw->phy_addr)
                         | GM_SMI_CT_REG_AD(reg) | GM_SMI_CT_OP_RD);

        for (i = 0; i < PHY_RETRIES; i++) {
                udelay(1);
                if (gma_read16(hw, port, GM_SMI_CTRL) & GM_SMI_CT_RD_VAL)
                        goto ready;
        }

        return -ETIMEDOUT;
 ready:
        *val = gma_read16(hw, port, GM_SMI_DATA);
        return 0;
}

static u16 gm_phy_read(struct skge_hw *hw, int port, u16 reg)
{
        u16 v = 0;
        if (__gm_phy_read(hw, port, reg, &v))
                DBG(PFX "%s: phy read timeout port %x reg %x val %x\n",
               hw->dev[port]->name,
               port, reg, v);
        return v;
}

/* Marvell Phy Initialization */
static void yukon_init(struct skge_hw *hw, int port)
{
        struct skge_port *skge = netdev_priv(hw->dev[port]);
        u16 ctrl, ct1000, adv;

        if (skge->autoneg == AUTONEG_ENABLE) {
                u16 ectrl = gm_phy_read(hw, port, PHY_MARV_EXT_CTRL);

                ectrl &= ~(PHY_M_EC_M_DSC_MSK | PHY_M_EC_S_DSC_MSK |
                          PHY_M_EC_MAC_S_MSK);
                ectrl |= PHY_M_EC_MAC_S(MAC_TX_CLK_25_MHZ);

                ectrl |= PHY_M_EC_M_DSC(0) | PHY_M_EC_S_DSC(1);

                gm_phy_write(hw, port, PHY_MARV_EXT_CTRL, ectrl);
        }

        ctrl = gm_phy_read(hw, port, PHY_MARV_CTRL);
        if (skge->autoneg == AUTONEG_DISABLE)
                ctrl &= ~PHY_CT_ANE;

        ctrl |= PHY_CT_RESET;
        gm_phy_write(hw, port, PHY_MARV_CTRL, ctrl);

        ctrl = 0;
        ct1000 = 0;
        adv = PHY_AN_CSMA;

        if (skge->autoneg == AUTONEG_ENABLE) {
                if (hw->copper) {
                        if (skge->advertising & ADVERTISED_1000baseT_Full)
                                ct1000 |= PHY_M_1000C_AFD;
                        if (skge->advertising & ADVERTISED_1000baseT_Half)
                                ct1000 |= PHY_M_1000C_AHD;
                        if (skge->advertising & ADVERTISED_100baseT_Full)
                                adv |= PHY_M_AN_100_FD;
                        if (skge->advertising & ADVERTISED_100baseT_Half)
                                adv |= PHY_M_AN_100_HD;
                        if (skge->advertising & ADVERTISED_10baseT_Full)
                                adv |= PHY_M_AN_10_FD;
                        if (skge->advertising & ADVERTISED_10baseT_Half)
                                adv |= PHY_M_AN_10_HD;

                        /* Set Flow-control capabilities */
                        adv |= phy_pause_map[skge->flow_control];
                } else {
                        if (skge->advertising & ADVERTISED_1000baseT_Full)
                                adv |= PHY_M_AN_1000X_AFD;
                        if (skge->advertising & ADVERTISED_1000baseT_Half)
                                adv |= PHY_M_AN_1000X_AHD;

                        adv |= fiber_pause_map[skge->flow_control];
                }

                /* Restart Auto-negotiation */
                ctrl |= PHY_CT_ANE | PHY_CT_RE_CFG;
        } else {
                /* forced speed/duplex settings */
                ct1000 = PHY_M_1000C_MSE;

                if (skge->duplex == DUPLEX_FULL)
                        ctrl |= PHY_CT_DUP_MD;

                switch (skge->speed) {
                case SPEED_1000:
                        ctrl |= PHY_CT_SP1000;
                        break;
                case SPEED_100:
                        ctrl |= PHY_CT_SP100;
                        break;
                }

                ctrl |= PHY_CT_RESET;
        }

        gm_phy_write(hw, port, PHY_MARV_1000T_CTRL, ct1000);

        gm_phy_write(hw, port, PHY_MARV_AUNE_ADV, adv);
        gm_phy_write(hw, port, PHY_MARV_CTRL, ctrl);

        /* Enable phy interrupt on autonegotiation complete (or link up) */
        if (skge->autoneg == AUTONEG_ENABLE)
                gm_phy_write(hw, port, PHY_MARV_INT_MASK, PHY_M_IS_AN_MSK);
        else
                gm_phy_write(hw, port, PHY_MARV_INT_MASK, PHY_M_IS_DEF_MSK);
}

static void yukon_reset(struct skge_hw *hw, int port)
{
        gm_phy_write(hw, port, PHY_MARV_INT_MASK, 0);/* disable PHY IRQs */
        gma_write16(hw, port, GM_MC_ADDR_H1, 0);        /* clear MC hash */
        gma_write16(hw, port, GM_MC_ADDR_H2, 0);
        gma_write16(hw, port, GM_MC_ADDR_H3, 0);
        gma_write16(hw, port, GM_MC_ADDR_H4, 0);

        gma_write16(hw, port, GM_RX_CTRL,
                         gma_read16(hw, port, GM_RX_CTRL)
                         | GM_RXCR_UCF_ENA | GM_RXCR_MCF_ENA);
}

/* Apparently, early versions of Yukon-Lite had wrong chip_id? */
static int is_yukon_lite_a0(struct skge_hw *hw)
{
        u32 reg;
        int ret;

        if (hw->chip_id != CHIP_ID_YUKON)
                return 0;

        reg = skge_read32(hw, B2_FAR);
        skge_write8(hw, B2_FAR + 3, 0xff);
        ret = (skge_read8(hw, B2_FAR + 3) != 0);
        skge_write32(hw, B2_FAR, reg);
        return ret;
}

static void yukon_mac_init(struct skge_hw *hw, int port)
{
        struct skge_port *skge = netdev_priv(hw->dev[port]);
        int i;
        u32 reg;
        const u8 *addr = hw->dev[port]->ll_addr;

        /* WA code for COMA mode -- set PHY reset */
        if (hw->chip_id == CHIP_ID_YUKON_LITE &&
            hw->chip_rev >= CHIP_REV_YU_LITE_A3) {
                reg = skge_read32(hw, B2_GP_IO);
                reg |= GP_DIR_9 | GP_IO_9;
                skge_write32(hw, B2_GP_IO, reg);
        }

        /* hard reset */
        skge_write32(hw, SK_REG(port, GPHY_CTRL), GPC_RST_SET);
        skge_write32(hw, SK_REG(port, GMAC_CTRL), GMC_RST_SET);

        /* WA code for COMA mode -- clear PHY reset */
        if (hw->chip_id == CHIP_ID_YUKON_LITE &&
            hw->chip_rev >= CHIP_REV_YU_LITE_A3) {
                reg = skge_read32(hw, B2_GP_IO);
                reg |= GP_DIR_9;
                reg &= ~GP_IO_9;
                skge_write32(hw, B2_GP_IO, reg);
        }

        /* Set hardware config mode */
        reg = GPC_INT_POL_HI | GPC_DIS_FC | GPC_DIS_SLEEP |
                GPC_ENA_XC | GPC_ANEG_ADV_ALL_M | GPC_ENA_PAUSE;
        reg |= hw->copper ? GPC_HWCFG_GMII_COP : GPC_HWCFG_GMII_FIB;

        /* Clear GMC reset */
        skge_write32(hw, SK_REG(port, GPHY_CTRL), reg | GPC_RST_SET);
        skge_write32(hw, SK_REG(port, GPHY_CTRL), reg | GPC_RST_CLR);
        skge_write32(hw, SK_REG(port, GMAC_CTRL), GMC_PAUSE_ON | GMC_RST_CLR);

        if (skge->autoneg == AUTONEG_DISABLE) {
                reg = GM_GPCR_AU_ALL_DIS;
                gma_write16(hw, port, GM_GP_CTRL,
                                 gma_read16(hw, port, GM_GP_CTRL) | reg);

                switch (skge->speed) {
                case SPEED_1000:
                        reg &= ~GM_GPCR_SPEED_100;
                        reg |= GM_GPCR_SPEED_1000;
                        break;
                case SPEED_100:
                        reg &= ~GM_GPCR_SPEED_1000;
                        reg |= GM_GPCR_SPEED_100;
                        break;
                case SPEED_10:
                        reg &= ~(GM_GPCR_SPEED_1000 | GM_GPCR_SPEED_100);
                        break;
                }

                if (skge->duplex == DUPLEX_FULL)
                        reg |= GM_GPCR_DUP_FULL;
        } else
                reg = GM_GPCR_SPEED_1000 | GM_GPCR_SPEED_100 | GM_GPCR_DUP_FULL;

        switch (skge->flow_control) {
        case FLOW_MODE_NONE:
                skge_write32(hw, SK_REG(port, GMAC_CTRL), GMC_PAUSE_OFF);
                reg |= GM_GPCR_FC_TX_DIS | GM_GPCR_FC_RX_DIS | GM_GPCR_AU_FCT_DIS;
                break;
        case FLOW_MODE_LOC_SEND:
                /* disable Rx flow-control */
                reg |= GM_GPCR_FC_RX_DIS | GM_GPCR_AU_FCT_DIS;
                break;
        case FLOW_MODE_SYMMETRIC:
        case FLOW_MODE_SYM_OR_REM:
                /* enable Tx & Rx flow-control */
                break;
        }

        gma_write16(hw, port, GM_GP_CTRL, reg);
        skge_read16(hw, SK_REG(port, GMAC_IRQ_SRC));

        yukon_init(hw, port);

        /* MIB clear */
        reg = gma_read16(hw, port, GM_PHY_ADDR);
        gma_write16(hw, port, GM_PHY_ADDR, reg | GM_PAR_MIB_CLR);

        for (i = 0; i < GM_MIB_CNT_SIZE; i++)
                gma_read16(hw, port, GM_MIB_CNT_BASE + 8*i);
        gma_write16(hw, port, GM_PHY_ADDR, reg);

        /* transmit control */
        gma_write16(hw, port, GM_TX_CTRL, TX_COL_THR(TX_COL_DEF));

        /* receive control reg: unicast + multicast + no FCS  */
        gma_write16(hw, port, GM_RX_CTRL,
                         GM_RXCR_UCF_ENA | GM_RXCR_CRC_DIS | GM_RXCR_MCF_ENA);

        /* transmit flow control */
        gma_write16(hw, port, GM_TX_FLOW_CTRL, 0xffff);

        /* transmit parameter */
        gma_write16(hw, port, GM_TX_PARAM,
                         TX_JAM_LEN_VAL(TX_JAM_LEN_DEF) |
                         TX_JAM_IPG_VAL(TX_JAM_IPG_DEF) |
                         TX_IPG_JAM_DATA(TX_IPG_JAM_DEF));

        /* configure the Serial Mode Register */
        reg = DATA_BLIND_VAL(DATA_BLIND_DEF)
                | GM_SMOD_VLAN_ENA
                | IPG_DATA_VAL(IPG_DATA_DEF);

        gma_write16(hw, port, GM_SERIAL_MODE, reg);

        /* physical address: used for pause frames */
        gma_set_addr(hw, port, GM_SRC_ADDR_1L, addr);
        /* virtual address for data */
        gma_set_addr(hw, port, GM_SRC_ADDR_2L, addr);

        /* enable interrupt mask for counter overflows */
        gma_write16(hw, port, GM_TX_IRQ_MSK, 0);
        gma_write16(hw, port, GM_RX_IRQ_MSK, 0);
        gma_write16(hw, port, GM_TR_IRQ_MSK, 0);

        /* Initialize Mac Fifo */

        /* Configure Rx MAC FIFO */
        skge_write16(hw, SK_REG(port, RX_GMF_FL_MSK), RX_FF_FL_DEF_MSK);
        reg = GMF_OPER_ON | GMF_RX_F_FL_ON;

        /* disable Rx GMAC FIFO Flush for YUKON-Lite Rev. A0 only */
        if (is_yukon_lite_a0(hw))
                reg &= ~GMF_RX_F_FL_ON;

        skge_write8(hw, SK_REG(port, RX_GMF_CTRL_T), GMF_RST_CLR);
        skge_write16(hw, SK_REG(port, RX_GMF_CTRL_T), reg);
        /*
         * because Pause Packet Truncation in GMAC is not working
         * we have to increase the Flush Threshold to 64 bytes
         * in order to flush pause packets in Rx FIFO on Yukon-1
         */
        skge_write16(hw, SK_REG(port, RX_GMF_FL_THR), RX_GMF_FL_THR_DEF+1);

        /* Configure Tx MAC FIFO */
        skge_write8(hw, SK_REG(port, TX_GMF_CTRL_T), GMF_RST_CLR);
        skge_write16(hw, SK_REG(port, TX_GMF_CTRL_T), GMF_OPER_ON);
}

/* Go into power down mode */
static void yukon_suspend(struct skge_hw *hw, int port)
{
        u16 ctrl;

        ctrl = gm_phy_read(hw, port, PHY_MARV_PHY_CTRL);
        ctrl |= PHY_M_PC_POL_R_DIS;
        gm_phy_write(hw, port, PHY_MARV_PHY_CTRL, ctrl);

        ctrl = gm_phy_read(hw, port, PHY_MARV_CTRL);
        ctrl |= PHY_CT_RESET;
        gm_phy_write(hw, port, PHY_MARV_CTRL, ctrl);

        /* switch IEEE compatible power down mode on */
        ctrl = gm_phy_read(hw, port, PHY_MARV_CTRL);
        ctrl |= PHY_CT_PDOWN;
        gm_phy_write(hw, port, PHY_MARV_CTRL, ctrl);
}

static void yukon_stop(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;

        skge_write8(hw, SK_REG(port, GMAC_IRQ_MSK), 0);
        yukon_reset(hw, port);

        gma_write16(hw, port, GM_GP_CTRL,
                         gma_read16(hw, port, GM_GP_CTRL)
                         & ~(GM_GPCR_TX_ENA|GM_GPCR_RX_ENA));
        gma_read16(hw, port, GM_GP_CTRL);

        yukon_suspend(hw, port);

        /* set GPHY Control reset */
        skge_write8(hw, SK_REG(port, GPHY_CTRL), GPC_RST_SET);
        skge_write8(hw, SK_REG(port, GMAC_CTRL), GMC_RST_SET);
}

static u16 yukon_speed(const struct skge_hw *hw __unused, u16 aux)
{
        switch (aux & PHY_M_PS_SPEED_MSK) {
        case PHY_M_PS_SPEED_1000:
                return SPEED_1000;
        case PHY_M_PS_SPEED_100:
                return SPEED_100;
        default:
                return SPEED_10;
        }
}

static void yukon_link_up(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 reg;

        /* Enable Transmit FIFO Underrun */
        skge_write8(hw, SK_REG(port, GMAC_IRQ_MSK), GMAC_DEF_MSK);

        reg = gma_read16(hw, port, GM_GP_CTRL);
        if (skge->duplex == DUPLEX_FULL || skge->autoneg == AUTONEG_ENABLE)
                reg |= GM_GPCR_DUP_FULL;

        /* enable Rx/Tx */
        reg |= GM_GPCR_RX_ENA | GM_GPCR_TX_ENA;
        gma_write16(hw, port, GM_GP_CTRL, reg);

        gm_phy_write(hw, port, PHY_MARV_INT_MASK, PHY_M_IS_DEF_MSK);
        skge_link_up(skge);
}

static void yukon_link_down(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u16 ctrl;

        ctrl = gma_read16(hw, port, GM_GP_CTRL);
        ctrl &= ~(GM_GPCR_RX_ENA | GM_GPCR_TX_ENA);
        gma_write16(hw, port, GM_GP_CTRL, ctrl);

        if (skge->flow_status == FLOW_STAT_REM_SEND) {
                ctrl = gm_phy_read(hw, port, PHY_MARV_AUNE_ADV);
                ctrl |= PHY_M_AN_ASP;
                /* restore Asymmetric Pause bit */
                gm_phy_write(hw, port, PHY_MARV_AUNE_ADV, ctrl);
        }

        skge_link_down(skge);

        yukon_init(hw, port);
}

static void yukon_phy_intr(struct skge_port *skge)
{
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        const char *reason = NULL;
        u16 istatus, phystat;

        istatus = gm_phy_read(hw, port, PHY_MARV_INT_STAT);
        phystat = gm_phy_read(hw, port, PHY_MARV_PHY_STAT);

        DBGIO(PFX "%s: phy interrupt status 0x%x 0x%x\n",
             skge->netdev->name, istatus, phystat);

        if (istatus & PHY_M_IS_AN_COMPL) {
                if (gm_phy_read(hw, port, PHY_MARV_AUNE_LP)
                    & PHY_M_AN_RF) {
                        reason = "remote fault";
                        goto failed;
                }

                if (gm_phy_read(hw, port, PHY_MARV_1000T_STAT) & PHY_B_1000S_MSF) {
                        reason = "master/slave fault";
                        goto failed;
                }

                if (!(phystat & PHY_M_PS_SPDUP_RES)) {
                        reason = "speed/duplex";
                        goto failed;
                }

                skge->duplex = (phystat & PHY_M_PS_FULL_DUP)
                        ? DUPLEX_FULL : DUPLEX_HALF;
                skge->speed = yukon_speed(hw, phystat);

                /* We are using IEEE 802.3z/D5.0 Table 37-4 */
                switch (phystat & PHY_M_PS_PAUSE_MSK) {
                case PHY_M_PS_PAUSE_MSK:
                        skge->flow_status = FLOW_STAT_SYMMETRIC;
                        break;
                case PHY_M_PS_RX_P_EN:
                        skge->flow_status = FLOW_STAT_REM_SEND;
                        break;
                case PHY_M_PS_TX_P_EN:
                        skge->flow_status = FLOW_STAT_LOC_SEND;
                        break;
                default:
                        skge->flow_status = FLOW_STAT_NONE;
                }

                if (skge->flow_status == FLOW_STAT_NONE ||
                    (skge->speed < SPEED_1000 && skge->duplex == DUPLEX_HALF))
                        skge_write8(hw, SK_REG(port, GMAC_CTRL), GMC_PAUSE_OFF);
                else
                        skge_write8(hw, SK_REG(port, GMAC_CTRL), GMC_PAUSE_ON);
                yukon_link_up(skge);
                return;
        }

        if (istatus & PHY_M_IS_LSP_CHANGE)
                skge->speed = yukon_speed(hw, phystat);

        if (istatus & PHY_M_IS_DUP_CHANGE)
                skge->duplex = (phystat & PHY_M_PS_FULL_DUP) ? DUPLEX_FULL : DUPLEX_HALF;
        if (istatus & PHY_M_IS_LST_CHANGE) {
                if (phystat & PHY_M_PS_LINK_UP)
                        yukon_link_up(skge);
                else
                        yukon_link_down(skge);
        }
        return;
 failed:
        DBG(PFX "%s: autonegotiation failed (%s)\n",
               skge->netdev->name, reason);

        /* XXX restart autonegotiation? */
}

static void skge_ramset(struct skge_hw *hw, u16 q, u32 start, size_t len)
{
        u32 end;

        start /= 8;
        len /= 8;
        end = start + len - 1;

        skge_write8(hw, RB_ADDR(q, RB_CTRL), RB_RST_CLR);
        skge_write32(hw, RB_ADDR(q, RB_START), start);
        skge_write32(hw, RB_ADDR(q, RB_WP), start);
        skge_write32(hw, RB_ADDR(q, RB_RP), start);
        skge_write32(hw, RB_ADDR(q, RB_END), end);

        if (q == Q_R1 || q == Q_R2) {
                /* Set thresholds on receive queue's */
                skge_write32(hw, RB_ADDR(q, RB_RX_UTPP),
                             start + (2*len)/3);
                skge_write32(hw, RB_ADDR(q, RB_RX_LTPP),
                             start + (len/3));
        } else {
                /* Enable store & forward on Tx queue's because
                 * Tx FIFO is only 4K on Genesis and 1K on Yukon
                 */
                skge_write8(hw, RB_ADDR(q, RB_CTRL), RB_ENA_STFWD);
        }

        skge_write8(hw, RB_ADDR(q, RB_CTRL), RB_ENA_OP_MD);
}

/* Setup Bus Memory Interface */
static void skge_qset(struct skge_port *skge, u16 q,
                      const struct skge_element *e)
{
        struct skge_hw *hw = skge->hw;
        u32 watermark = 0x600;
        u64 base = skge->dma + (e->desc - skge->mem);

        /* optimization to reduce window on 32bit/33mhz */
        if ((skge_read16(hw, B0_CTST) & (CS_BUS_CLOCK | CS_BUS_SLOT_SZ)) == 0)
                watermark /= 2;

        skge_write32(hw, Q_ADDR(q, Q_CSR), CSR_CLR_RESET);
        skge_write32(hw, Q_ADDR(q, Q_F), watermark);
        skge_write32(hw, Q_ADDR(q, Q_DA_H), (u32)(base >> 32));
        skge_write32(hw, Q_ADDR(q, Q_DA_L), (u32)base);
}

void skge_free(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);

        free(skge->rx_ring.start);
        skge->rx_ring.start = NULL;

        free(skge->tx_ring.start);
        skge->tx_ring.start = NULL;

        free_dma(skge->mem, RING_SIZE);
        skge->mem = NULL;
        skge->dma = 0;
}

static int skge_up(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;
        int port = skge->port;
        u32 chunk, ram_addr;
        int err;

        DBG2(PFX "%s: enabling interface\n", dev->name);

        skge->mem = malloc_dma(RING_SIZE, SKGE_RING_ALIGN);
        skge->dma = virt_to_bus(skge->mem);
        if (!skge->mem)
                return -ENOMEM;
        memset(skge->mem, 0, RING_SIZE);

        assert(!(skge->dma & 7));

        /* FIXME: find out whether 64 bit gPXE will be loaded > 4GB */
        if ((u64)skge->dma >> 32 != ((u64) skge->dma + RING_SIZE) >> 32) {
                DBG(PFX "pci_alloc_consistent region crosses 4G boundary\n");
                err = -EINVAL;
                goto err;
        }

        err = skge_ring_alloc(&skge->rx_ring, skge->mem, skge->dma, NUM_RX_DESC);
        if (err)
                goto err;

        /* this call relies on e->iob and d->control to be 0
         * This is assured by calling memset() on skge->mem and using zalloc()
         * for the skge_element structures.
         */
        skge_rx_refill(dev);

        err = skge_ring_alloc(&skge->tx_ring, skge->mem + RX_RING_SIZE,
                              skge->dma + RX_RING_SIZE, NUM_TX_DESC);
        if (err)
                goto err;

        /* Initialize MAC */
        if (hw->chip_id == CHIP_ID_GENESIS)
                genesis_mac_init(hw, port);
        else
                yukon_mac_init(hw, port);

        /* Configure RAMbuffers - equally between ports and tx/rx */
        chunk = (hw->ram_size  - hw->ram_offset) / (hw->ports * 2);
        ram_addr = hw->ram_offset + 2 * chunk * port;

        skge_ramset(hw, rxqaddr[port], ram_addr, chunk);
        skge_qset(skge, rxqaddr[port], skge->rx_ring.to_clean);

        assert(!(skge->tx_ring.to_use != skge->tx_ring.to_clean));
        skge_ramset(hw, txqaddr[port], ram_addr+chunk, chunk);
        skge_qset(skge, txqaddr[port], skge->tx_ring.to_use);

        /* Start receiver BMU */
        wmb();
        skge_write8(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_START | CSR_IRQ_CL_F);
        skge_led(skge, LED_MODE_ON);

        hw->intr_mask |= portmask[port];
        skge_write32(hw, B0_IMSK, hw->intr_mask);

        return 0;

 err:
        skge_rx_clean(skge);
        skge_free(dev);

        return err;
}

/* stop receiver */
static void skge_rx_stop(struct skge_hw *hw, int port)
{
        skge_write8(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_STOP);
        skge_write32(hw, RB_ADDR(port ? Q_R2 : Q_R1, RB_CTRL),
                     RB_RST_SET|RB_DIS_OP_MD);
        skge_write32(hw, Q_ADDR(rxqaddr[port], Q_CSR), CSR_SET_RESET);
}

static void skge_down(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;
        int port = skge->port;

        if (skge->mem == NULL)
                return;

        DBG2(PFX "%s: disabling interface\n", dev->name);

        if (hw->chip_id == CHIP_ID_GENESIS && hw->phy_type == SK_PHY_XMAC)
                skge->use_xm_link_timer = 0;

        netdev_link_down(dev);

        hw->intr_mask &= ~portmask[port];
        skge_write32(hw, B0_IMSK, hw->intr_mask);

        skge_write8(skge->hw, SK_REG(skge->port, LNK_LED_REG), LED_OFF);
        if (hw->chip_id == CHIP_ID_GENESIS)
                genesis_stop(skge);
        else
                yukon_stop(skge);

        /* Stop transmitter */
        skge_write8(hw, Q_ADDR(txqaddr[port], Q_CSR), CSR_STOP);
        skge_write32(hw, RB_ADDR(txqaddr[port], RB_CTRL),
                     RB_RST_SET|RB_DIS_OP_MD);


        /* Disable Force Sync bit and Enable Alloc bit */
        skge_write8(hw, SK_REG(port, TXA_CTRL),
                    TXA_DIS_FSYNC | TXA_DIS_ALLOC | TXA_STOP_RC);

        /* Stop Interval Timer and Limit Counter of Tx Arbiter */
        skge_write32(hw, SK_REG(port, TXA_ITI_INI), 0L);
        skge_write32(hw, SK_REG(port, TXA_LIM_INI), 0L);

        /* Reset PCI FIFO */
        skge_write32(hw, Q_ADDR(txqaddr[port], Q_CSR), CSR_SET_RESET);
        skge_write32(hw, RB_ADDR(txqaddr[port], RB_CTRL), RB_RST_SET);

        /* Reset the RAM Buffer async Tx queue */
        skge_write8(hw, RB_ADDR(port == 0 ? Q_XA1 : Q_XA2, RB_CTRL), RB_RST_SET);

        skge_rx_stop(hw, port);

        if (hw->chip_id == CHIP_ID_GENESIS) {
                skge_write8(hw, SK_REG(port, TX_MFF_CTRL2), MFF_RST_SET);
                skge_write8(hw, SK_REG(port, RX_MFF_CTRL2), MFF_RST_SET);
        } else {
                skge_write8(hw, SK_REG(port, RX_GMF_CTRL_T), GMF_RST_SET);
                skge_write8(hw, SK_REG(port, TX_GMF_CTRL_T), GMF_RST_SET);
        }

        skge_led(skge, LED_MODE_OFF);

        skge_tx_clean(dev);

        skge_rx_clean(skge);

        skge_free(dev);
        return;
}

static inline int skge_tx_avail(const struct skge_ring *ring)
{
        mb();
        return ((ring->to_clean > ring->to_use) ? 0 : NUM_TX_DESC)
                + (ring->to_clean - ring->to_use) - 1;
}

static int skge_xmit_frame(struct net_device *dev, struct io_buffer *iob)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;
        struct skge_element *e;
        struct skge_tx_desc *td;
        u32 control, len;
        u64 map;

        if (skge_tx_avail(&skge->tx_ring) < 1)
                return -EBUSY;

        e = skge->tx_ring.to_use;
        td = e->desc;
        assert(!(td->control & BMU_OWN));
        e->iob = iob;
        len = iob_len(iob);
        map = virt_to_bus(iob->data);

        td->dma_lo = map;
        td->dma_hi = map >> 32;

        control = BMU_CHECK;

        control |= BMU_EOF| BMU_IRQ_EOF;
        /* Make sure all the descriptors written */
        wmb();
        td->control = BMU_OWN | BMU_SW | BMU_STF | control | len;
        wmb();

        skge_write8(hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_START);

        DBGIO(PFX "%s: tx queued, slot %td, len %d\n",
             dev->name, e - skge->tx_ring.start, (unsigned int)len);

        skge->tx_ring.to_use = e->next;
        wmb();

        if (skge_tx_avail(&skge->tx_ring) <= 1) {
                DBG(PFX "%s: transmit queue full\n", dev->name);
        }

        return 0;
}

/* Free all buffers in transmit ring */
static void skge_tx_clean(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_element *e;

        for (e = skge->tx_ring.to_clean; e != skge->tx_ring.to_use; e = e->next) {
                struct skge_tx_desc *td = e->desc;
                td->control = 0;
        }

        skge->tx_ring.to_clean = e;
}

static const u8 pause_mc_addr[ETH_ALEN] = { 0x1, 0x80, 0xc2, 0x0, 0x0, 0x1 };

static inline u16 phy_length(const struct skge_hw *hw, u32 status)
{
        if (hw->chip_id == CHIP_ID_GENESIS)
                return status >> XMR_FS_LEN_SHIFT;
        else
                return status >> GMR_FS_LEN_SHIFT;
}

static inline int bad_phy_status(const struct skge_hw *hw, u32 status)
{
        if (hw->chip_id == CHIP_ID_GENESIS)
                return (status & (XMR_FS_ERR | XMR_FS_2L_VLAN)) != 0;
        else
                return (status & GMR_FS_ANY_ERR) ||
                        (status & GMR_FS_RX_OK) == 0;
}

/* Free all buffers in Tx ring which are no longer owned by device */
static void skge_tx_done(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_ring *ring = &skge->tx_ring;
        struct skge_element *e;

        skge_write8(skge->hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F);

        for (e = ring->to_clean; e != ring->to_use; e = e->next) {
                u32 control = ((const struct skge_tx_desc *) e->desc)->control;

                if (control & BMU_OWN)
                        break;

                netdev_tx_complete(dev, e->iob);
        }
        skge->tx_ring.to_clean = e;

        /* Can run lockless until we need to synchronize to restart queue. */
        mb();
}

static void skge_rx_refill(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_ring *ring = &skge->rx_ring;
        struct skge_element *e;
        struct io_buffer *iob;
        struct skge_rx_desc *rd;
        u32 control;
        int i;

        for (i = 0; i < NUM_RX_DESC; i++) {
                e = ring->to_clean;
                rd = e->desc;
                iob = e->iob;
                control = rd->control;

                /* nothing to do here */
                if (iob || (control & BMU_OWN))
                        continue;

                DBG2("refilling rx desc %d: ", (ring->to_clean - ring->start));

                iob = alloc_iob(RX_BUF_SIZE);
                if (iob) {
                        skge_rx_setup(skge, e, iob, RX_BUF_SIZE);
                } else {
                        DBG("descr %d: alloc_iob() failed\n",
                             (ring->to_clean - ring->start));
                        /* We pass the descriptor to the NIC even if the
                         * allocation failed. The card will stop as soon as it
                         * encounters a descriptor with the OWN bit set to 0,
                         * thus never getting to the next descriptor that might
                         * contain a valid io_buffer. This would effectively
                         * stall the receive.
                         */
                        skge_rx_setup(skge, e, NULL, 0);
                }

                ring->to_clean = e->next;
        }
}

static void skge_rx_done(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_ring *ring = &skge->rx_ring;
        struct skge_rx_desc *rd;
        struct skge_element *e;
        struct io_buffer *iob;
        u32 control;
        u16 len;
        int i;

        e = ring->to_clean;
        for (i = 0; i < NUM_RX_DESC; i++) {
                iob = e->iob;
                rd = e->desc;

                rmb();
                control = rd->control;

                if ((control & BMU_OWN))
                        break;

                if (!iob)
                        continue;

                len = control & BMU_BBC;

                /* catch RX errors */
                if ((bad_phy_status(skge->hw, rd->status)) ||
                   (phy_length(skge->hw, rd->status) != len)) {
                        /* report receive errors */
                        DBG("rx error\n");
                        netdev_rx_err(dev, iob, -EIO);
                } else {
                        DBG2("received packet, len %d\n", len);
                        iob_put(iob, len);
                        netdev_rx(dev, iob);
                }

                /* io_buffer passed to core, make sure we don't reuse it */
                e->iob = NULL;

                e = e->next;
        }
        skge_rx_refill(dev);
}

static void skge_poll(struct net_device *dev)
{
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;
        u32 status;

        /* reading this register ACKs interrupts */
        status = skge_read32(hw, B0_SP_ISRC);

        /* Link event? */
        if (status & IS_EXT_REG) {
                skge_phyirq(hw);
                if (skge->use_xm_link_timer)
                        xm_link_timer(skge);
        }

        skge_tx_done(dev);

        skge_write8(hw, Q_ADDR(rxqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F);

        skge_rx_done(dev);

        /* restart receiver */
        wmb();
        skge_write8(hw, Q_ADDR(rxqaddr[skge->port], Q_CSR), CSR_START);

        skge_read32(hw, B0_IMSK);

        return;
}

static void skge_phyirq(struct skge_hw *hw)
{
        int port;

        for (port = 0; port < hw->ports; port++) {
                struct net_device *dev = hw->dev[port];
                struct skge_port *skge = netdev_priv(dev);

                if (hw->chip_id != CHIP_ID_GENESIS)
                        yukon_phy_intr(skge);
                else if (hw->phy_type == SK_PHY_BCOM)
                        bcom_phy_intr(skge);
        }

        hw->intr_mask |= IS_EXT_REG;
        skge_write32(hw, B0_IMSK, hw->intr_mask);
        skge_read32(hw, B0_IMSK);
}

static const struct {
        u8 id;
        const char *name;
} skge_chips[] = {
        { CHIP_ID_GENESIS,      "Genesis" },
        { CHIP_ID_YUKON,         "Yukon" },
        { CHIP_ID_YUKON_LITE,    "Yukon-Lite"},
        { CHIP_ID_YUKON_LP,      "Yukon-LP"},
};

static const char *skge_board_name(const struct skge_hw *hw)
{
        unsigned int i;
        static char buf[16];

        for (i = 0; i < ARRAY_SIZE(skge_chips); i++)
                if (skge_chips[i].id == hw->chip_id)
                        return skge_chips[i].name;

        snprintf(buf, sizeof buf, "chipid 0x%x", hw->chip_id);
        return buf;
}


/*
 * Setup the board data structure, but don't bring up
 * the port(s)
 */
static int skge_reset(struct skge_hw *hw)
{
        u32 reg;
        u16 ctst, pci_status;
        u8 t8, mac_cfg, pmd_type;
        int i;

        ctst = skge_read16(hw, B0_CTST);

        /* do a SW reset */
        skge_write8(hw, B0_CTST, CS_RST_SET);
        skge_write8(hw, B0_CTST, CS_RST_CLR);

        /* clear PCI errors, if any */
        skge_write8(hw, B2_TST_CTRL1, TST_CFG_WRITE_ON);
        skge_write8(hw, B2_TST_CTRL2, 0);

        pci_read_config_word(hw->pdev, PCI_STATUS, &pci_status);
        pci_write_config_word(hw->pdev, PCI_STATUS,
                              pci_status | PCI_STATUS_ERROR_BITS);
        skge_write8(hw, B2_TST_CTRL1, TST_CFG_WRITE_OFF);
        skge_write8(hw, B0_CTST, CS_MRST_CLR);

        /* restore CLK_RUN bits (for Yukon-Lite) */
        skge_write16(hw, B0_CTST,
                     ctst & (CS_CLK_RUN_HOT|CS_CLK_RUN_RST|CS_CLK_RUN_ENA));

        hw->chip_id = skge_read8(hw, B2_CHIP_ID);
        hw->phy_type = skge_read8(hw, B2_E_1) & 0xf;
        pmd_type = skge_read8(hw, B2_PMD_TYP);
        hw->copper = (pmd_type == 'T' || pmd_type == '1');

        switch (hw->chip_id) {
        case CHIP_ID_GENESIS:
                switch (hw->phy_type) {
                case SK_PHY_XMAC:
                        hw->phy_addr = PHY_ADDR_XMAC;
                        break;
                case SK_PHY_BCOM:
                        hw->phy_addr = PHY_ADDR_BCOM;
                        break;
                default:
                        DBG(PFX "unsupported phy type 0x%x\n",
                               hw->phy_type);
                        return -EOPNOTSUPP;
                }
                break;

        case CHIP_ID_YUKON:
        case CHIP_ID_YUKON_LITE:
        case CHIP_ID_YUKON_LP:
                if (hw->phy_type < SK_PHY_MARV_COPPER && pmd_type != 'S')
                        hw->copper = 1;

                hw->phy_addr = PHY_ADDR_MARV;
                break;

        default:
                DBG(PFX "unsupported chip type 0x%x\n",
                       hw->chip_id);
                return -EOPNOTSUPP;
        }

        mac_cfg = skge_read8(hw, B2_MAC_CFG);
        hw->ports = (mac_cfg & CFG_SNG_MAC) ? 1 : 2;
        hw->chip_rev = (mac_cfg & CFG_CHIP_R_MSK) >> 4;

        /* read the adapters RAM size */
        t8 = skge_read8(hw, B2_E_0);
        if (hw->chip_id == CHIP_ID_GENESIS) {
                if (t8 == 3) {
                        /* special case: 4 x 64k x 36, offset = 0x80000 */
                        hw->ram_size = 0x100000;
                        hw->ram_offset = 0x80000;
                } else
                        hw->ram_size = t8 * 512;
        }
        else if (t8 == 0)
                hw->ram_size = 0x20000;
        else
                hw->ram_size = t8 * 4096;

        hw->intr_mask = IS_HW_ERR;

        /* Use PHY IRQ for all but fiber based Genesis board */
        if (!(hw->chip_id == CHIP_ID_GENESIS && hw->phy_type == SK_PHY_XMAC))
                hw->intr_mask |= IS_EXT_REG;

        if (hw->chip_id == CHIP_ID_GENESIS)
                genesis_init(hw);
        else {
                /* switch power to VCC (WA for VAUX problem) */
                skge_write8(hw, B0_POWER_CTRL,
                            PC_VAUX_ENA | PC_VCC_ENA | PC_VAUX_OFF | PC_VCC_ON);

                /* avoid boards with stuck Hardware error bits */
                if ((skge_read32(hw, B0_ISRC) & IS_HW_ERR) &&
                    (skge_read32(hw, B0_HWE_ISRC) & IS_IRQ_SENSOR)) {
                        DBG(PFX "stuck hardware sensor bit\n");
                        hw->intr_mask &= ~IS_HW_ERR;
                }

                /* Clear PHY COMA */
                skge_write8(hw, B2_TST_CTRL1, TST_CFG_WRITE_ON);
                pci_read_config_dword(hw->pdev, PCI_DEV_REG1, &reg);
                reg &= ~PCI_PHY_COMA;
                pci_write_config_dword(hw->pdev, PCI_DEV_REG1, reg);
                skge_write8(hw, B2_TST_CTRL1, TST_CFG_WRITE_OFF);


                for (i = 0; i < hw->ports; i++) {
                        skge_write16(hw, SK_REG(i, GMAC_LINK_CTRL), GMLC_RST_SET);
                        skge_write16(hw, SK_REG(i, GMAC_LINK_CTRL), GMLC_RST_CLR);
                }
        }

        /* turn off hardware timer (unused) */
        skge_write8(hw, B2_TI_CTRL, TIM_STOP);
        skge_write8(hw, B2_TI_CTRL, TIM_CLR_IRQ);
        skge_write8(hw, B0_LED, LED_STAT_ON);

        /* enable the Tx Arbiters */
        for (i = 0; i < hw->ports; i++)
                skge_write8(hw, SK_REG(i, TXA_CTRL), TXA_ENA_ARB);

        /* Initialize ram interface */
        skge_write16(hw, B3_RI_CTRL, RI_RST_CLR);

        skge_write8(hw, B3_RI_WTO_R1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_WTO_XA1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_WTO_XS1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_R1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_XA1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_XS1, SK_RI_TO_53);
        skge_write8(hw, B3_RI_WTO_R2, SK_RI_TO_53);
        skge_write8(hw, B3_RI_WTO_XA2, SK_RI_TO_53);
        skge_write8(hw, B3_RI_WTO_XS2, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_R2, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_XA2, SK_RI_TO_53);
        skge_write8(hw, B3_RI_RTO_XS2, SK_RI_TO_53);

        skge_write32(hw, B0_HWE_IMSK, IS_ERR_MSK);

        /* Set interrupt moderation for Transmit only
         * Receive interrupts avoided by NAPI
         */
        skge_write32(hw, B2_IRQM_MSK, IS_XA1_F|IS_XA2_F);
        skge_write32(hw, B2_IRQM_INI, skge_usecs2clk(hw, 100));
        skge_write32(hw, B2_IRQM_CTRL, TIM_START);

        skge_write32(hw, B0_IMSK, hw->intr_mask);

        for (i = 0; i < hw->ports; i++) {
                if (hw->chip_id == CHIP_ID_GENESIS)
                        genesis_reset(hw, i);
                else
                        yukon_reset(hw, i);
        }

        return 0;
}

/* Initialize network device */
static struct net_device *skge_devinit(struct skge_hw *hw, int port,
                                       int highmem __unused)
{
        struct skge_port *skge;
        struct net_device *dev = alloc_etherdev(sizeof(*skge));

        if (!dev) {
                DBG(PFX "etherdev alloc failed\n");
                return NULL;
        }

        dev->dev = &hw->pdev->dev;

        skge = netdev_priv(dev);
        skge->netdev = dev;
        skge->hw = hw;

        /* Auto speed and flow control */
        skge->autoneg = AUTONEG_ENABLE;
        skge->flow_control = FLOW_MODE_SYM_OR_REM;
        skge->duplex = -1;
        skge->speed = -1;
        skge->advertising = skge_supported_modes(hw);

        hw->dev[port] = dev;

        skge->port = port;

        /* read the mac address */
        memcpy(dev->hw_addr, (void *) (hw->regs + B2_MAC_1 + port*8), ETH_ALEN);

        /* device is off until link detection */
        netdev_link_down(dev);

        return dev;
}

static void skge_show_addr(struct net_device *dev)
{
        DBG2(PFX "%s: addr %s\n",
             dev->name, netdev_addr(dev));
}

static int skge_probe(struct pci_device *pdev,
                                const struct pci_device_id *ent __unused)
{
        struct net_device *dev, *dev1;
        struct skge_hw *hw;
        int err, using_dac = 0;

        adjust_pci_device(pdev);

        err = -ENOMEM;
        hw = zalloc(sizeof(*hw));
        if (!hw) {
                DBG(PFX "cannot allocate hardware struct\n");
                goto err_out_free_regions;
        }

        hw->pdev = pdev;

        hw->regs = (u32)ioremap(pci_bar_start(pdev, PCI_BASE_ADDRESS_0),
                                SKGE_REG_SIZE);
        if (!hw->regs) {
                DBG(PFX "cannot map device registers\n");
                goto err_out_free_hw;
        }

        err = skge_reset(hw);
        if (err)
                goto err_out_iounmap;

        DBG(PFX " addr 0x%llx irq %d chip %s rev %d\n",
            (unsigned long long)pdev->ioaddr, pdev->irq,
            skge_board_name(hw), hw->chip_rev);

        dev = skge_devinit(hw, 0, using_dac);
        if (!dev)
                goto err_out_led_off;

        netdev_init ( dev, &skge_operations );

        err = register_netdev(dev);
        if (err) {
                DBG(PFX "cannot register net device\n");
                goto err_out_free_netdev;
        }

        skge_show_addr(dev);

        if (hw->ports > 1 && (dev1 = skge_devinit(hw, 1, using_dac))) {
                if (register_netdev(dev1) == 0)
                        skge_show_addr(dev1);
                else {
                        /* Failure to register second port need not be fatal */
                        DBG(PFX "register of second port failed\n");
                        hw->dev[1] = NULL;
                        netdev_nullify(dev1);
                        netdev_put(dev1);
                }
        }
        pci_set_drvdata(pdev, hw);

        return 0;

err_out_free_netdev:
        netdev_nullify(dev);
        netdev_put(dev);
err_out_led_off:
        skge_write16(hw, B0_LED, LED_STAT_OFF);
err_out_iounmap:
        iounmap((void*)hw->regs);
err_out_free_hw:
        free(hw);
err_out_free_regions:
        pci_set_drvdata(pdev, NULL);
        return err;
}

static void skge_remove(struct pci_device *pdev)
{
        struct skge_hw *hw  = pci_get_drvdata(pdev);
        struct net_device *dev0, *dev1;

        if (!hw)
                return;

        if ((dev1 = hw->dev[1]))
                unregister_netdev(dev1);
        dev0 = hw->dev[0];
        unregister_netdev(dev0);

        hw->intr_mask = 0;
        skge_write32(hw, B0_IMSK, 0);
        skge_read32(hw, B0_IMSK);

        skge_write16(hw, B0_LED, LED_STAT_OFF);
        skge_write8(hw, B0_CTST, CS_RST_SET);

        if (dev1) {
                netdev_nullify(dev1);
                netdev_put(dev1);
        }
        netdev_nullify(dev0);
        netdev_put(dev0);

        iounmap((void*)hw->regs);
        free(hw);
        pci_set_drvdata(pdev, NULL);
}

/*
 * Enable or disable IRQ masking.
 *
 * @v netdev            Device to control.
 * @v enable            Zero to mask off IRQ, non-zero to enable IRQ.
 *
 * This is a gPXE Network Driver API function.
 */
static void skge_net_irq ( struct net_device *dev, int enable ) {
        struct skge_port *skge = netdev_priv(dev);
        struct skge_hw *hw = skge->hw;

        if (enable)
                hw->intr_mask |= portmask[skge->port];
        else
                hw->intr_mask &= ~portmask[skge->port];
        skge_write32(hw, B0_IMSK, hw->intr_mask);
}

struct pci_driver skge_driver __pci_driver = {
        .ids      = skge_id_table,
        .id_count = ( sizeof (skge_id_table) / sizeof (skge_id_table[0]) ),
        .probe    = skge_probe,
        .remove   = skge_remove
};