Initial import from FreeBSD RELENG_4:

[dragonfly.git] / sys / dev / netif / xl / if_xl.c

/*
 * Copyright (c) 1997, 1998, 1999
 *      Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/pci/if_xl.c,v 1.72.2.25 2003/02/05 22:03:58 mbr Exp $
 */

/*
 * 3Com 3c90x Etherlink XL PCI NIC driver
 *
 * Supports the 3Com "boomerang", "cyclone" and "hurricane" PCI
 * bus-master chips (3c90x cards and embedded controllers) including
 * the following:
 *
 * 3Com 3c900-TPO       10Mbps/RJ-45
 * 3Com 3c900-COMBO     10Mbps/RJ-45,AUI,BNC
 * 3Com 3c905-TX        10/100Mbps/RJ-45
 * 3Com 3c905-T4        10/100Mbps/RJ-45
 * 3Com 3c900B-TPO      10Mbps/RJ-45
 * 3Com 3c900B-COMBO    10Mbps/RJ-45,AUI,BNC
 * 3Com 3c900B-TPC      10Mbps/RJ-45,BNC
 * 3Com 3c900B-FL       10Mbps/Fiber-optic
 * 3Com 3c905B-COMBO    10/100Mbps/RJ-45,AUI,BNC
 * 3Com 3c905B-TX       10/100Mbps/RJ-45
 * 3Com 3c905B-FL/FX    10/100Mbps/Fiber-optic
 * 3Com 3c905C-TX       10/100Mbps/RJ-45 (Tornado ASIC)
 * 3Com 3c980-TX        10/100Mbps server adapter (Hurricane ASIC)
 * 3Com 3c980C-TX       10/100Mbps server adapter (Tornado ASIC)
 * 3Com 3cSOHO100-TX    10/100Mbps/RJ-45 (Hurricane ASIC)
 * 3Com 3c450-TX        10/100Mbps/RJ-45 (Tornado ASIC)
 * 3Com 3c555           10/100Mbps/RJ-45 (MiniPCI, Laptop Hurricane)
 * 3Com 3c556           10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
 * 3Com 3c556B          10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
 * 3Com 3c575TX         10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3c575B          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3c575C          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656       10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656b      10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656c      10/100Mbps/RJ-45 (Cardbus, Tornado ASIC)
 * Dell Optiplex GX1 on-board 3c918 10/100Mbps/RJ-45
 * Dell on-board 3c920 10/100Mbps/RJ-45
 * Dell Precision on-board 3c905B 10/100Mbps/RJ-45
 * Dell Latitude laptop docking station embedded 3c905-TX
 *
 * Written by Bill Paul <wpaul@ctr.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */

/*
 * The 3c90x series chips use a bus-master DMA interface for transfering
 * packets to and from the controller chip. Some of the "vortex" cards
 * (3c59x) also supported a bus master mode, however for those chips
 * you could only DMA packets to/from a contiguous memory buffer. For
 * transmission this would mean copying the contents of the queued mbuf
 * chain into a an mbuf cluster and then DMAing the cluster. This extra
 * copy would sort of defeat the purpose of the bus master support for
 * any packet that doesn't fit into a single mbuf.
 *
 * By contrast, the 3c90x cards support a fragment-based bus master
 * mode where mbuf chains can be encapsulated using TX descriptors.
 * This is similar to other PCI chips such as the Texas Instruments
 * ThunderLAN and the Intel 82557/82558.
 *
 * The "vortex" driver (if_vx.c) happens to work for the "boomerang"
 * bus master chips because they maintain the old PIO interface for
 * backwards compatibility, but starting with the 3c905B and the
 * "cyclone" chips, the compatibility interface has been dropped.
 * Since using bus master DMA is a big win, we use this driver to
 * support the PCI "boomerang" chips even though they work with the
 * "vortex" driver in order to obtain better performance.
 *
 * This driver is in the /sys/pci directory because it only supports
 * PCI-based NICs.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>

#include <net/if.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>

#include <net/bpf.h>

#include <vm/vm.h>              /* for vtophys */
#include <vm/pmap.h>            /* for vtophys */
#include <machine/clock.h>      /* for DELAY */
#include <machine/bus_memio.h>
#include <machine/bus_pio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>

#include <pci/pcireg.h>
#include <pci/pcivar.h>

MODULE_DEPEND(xl, miibus, 1, 1, 1);

/* "controller miibus0" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"

/*
 * The following #define causes the code to use PIO to access the
 * chip's registers instead of memory mapped mode. The reason PIO mode
 * is on by default is that the Etherlink XL manual seems to indicate
 * that only the newer revision chips (3c905B) support both PIO and
 * memory mapped access. Since we want to be compatible with the older
 * bus master chips, we use PIO here. If you comment this out, the
 * driver will use memory mapped I/O, which may be faster but which
 * might not work on some devices.
 */
#define XL_USEIOSPACE

#include <pci/if_xlreg.h>

#if !defined(lint)
static const char rcsid[] =
  "$FreeBSD: src/sys/pci/if_xl.c,v 1.72.2.25 2003/02/05 22:03:58 mbr Exp $";
#endif

#define XL905B_CSUM_FEATURES    (CSUM_IP | CSUM_TCP | CSUM_UDP)

/*
 * Various supported device vendors/types and their names.
 */
static struct xl_type xl_devs[] = {
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT,
                "3Com 3c900-TPO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT_COMBO,
                "3Com 3c900-COMBO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10_100BT,
                "3Com 3c905-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_100BT4,
                "3Com 3c905-T4 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT,
                "3Com 3c900B-TPO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_COMBO,
                "3Com 3c900B-COMBO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_TPC,
                "3Com 3c900B-TPC Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10FL,
                "3Com 3c900B-FL Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT,
                "3Com 3c905B-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100BT4,
                "3Com 3c905B-T4 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100FX,
                "3Com 3c905B-FX/SC Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100_COMBO,
                "3Com 3c905B-COMBO Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT,
                "3Com 3c905C-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_920B,
                "3Com 3c920B-EMB Integrated Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT_SERV,
                "3Com 3c980 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_SERV,
                "3Com 3c980C Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_SOHO100TX,
                "3Com 3cSOHO100-TX OfficeConnect" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_HOMECONNECT,
                "3Com 3c450-TX HomeConnect" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_555,
                "3Com 3c555 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_556,
                "3Com 3c556 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_556B,
                "3Com 3c556B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575A,
                "3Com 3c575TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575B,
                "3Com 3c575B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575C,
                "3Com 3c575C Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_656,
                "3Com 3c656 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_656B,
                "3Com 3c656B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_656C,
                "3Com 3c656C Fast Etherlink XL" },
        { 0, 0, NULL }
};

static int xl_probe             (device_t);
static int xl_attach            (device_t);
static int xl_detach            (device_t);

static int xl_newbuf            (struct xl_softc *, struct xl_chain_onefrag *);
static void xl_stats_update     (void *);
static int xl_encap             (struct xl_softc *, struct xl_chain *,
                                                struct mbuf *);
static void xl_rxeof            (struct xl_softc *);
static int xl_rx_resync         (struct xl_softc *);
static void xl_txeof            (struct xl_softc *);
static void xl_txeof_90xB       (struct xl_softc *);
static void xl_txeoc            (struct xl_softc *);
static void xl_intr             (void *);
static void xl_start            (struct ifnet *);
static void xl_start_90xB       (struct ifnet *);
static int xl_ioctl             (struct ifnet *, u_long, caddr_t);
static void xl_init             (void *);
static void xl_stop             (struct xl_softc *);
static void xl_watchdog         (struct ifnet *);
static void xl_shutdown         (device_t);
static int xl_suspend           (device_t); 
static int xl_resume            (device_t);

static int xl_ifmedia_upd       (struct ifnet *);
static void xl_ifmedia_sts      (struct ifnet *, struct ifmediareq *);

static int xl_eeprom_wait       (struct xl_softc *);
static int xl_read_eeprom       (struct xl_softc *, caddr_t, int, int, int);
static void xl_mii_sync         (struct xl_softc *);
static void xl_mii_send         (struct xl_softc *, u_int32_t, int);
static int xl_mii_readreg       (struct xl_softc *, struct xl_mii_frame *);
static int xl_mii_writereg      (struct xl_softc *, struct xl_mii_frame *);

static void xl_setcfg           (struct xl_softc *);
static void xl_setmode          (struct xl_softc *, int);
static u_int8_t xl_calchash     (caddr_t);
static void xl_setmulti         (struct xl_softc *);
static void xl_setmulti_hash    (struct xl_softc *);
static void xl_reset            (struct xl_softc *);
static int xl_list_rx_init      (struct xl_softc *);
static int xl_list_tx_init      (struct xl_softc *);
static int xl_list_tx_init_90xB (struct xl_softc *);
static void xl_wait             (struct xl_softc *);
static void xl_mediacheck       (struct xl_softc *);
static void xl_choose_xcvr      (struct xl_softc *, int);
#ifdef notdef
static void xl_testpacket       (struct xl_softc *);
#endif

static int xl_miibus_readreg    (device_t, int, int);
static int xl_miibus_writereg   (device_t, int, int, int);
static void xl_miibus_statchg   (device_t);
static void xl_miibus_mediainit (device_t);

#ifdef XL_USEIOSPACE
#define XL_RES                  SYS_RES_IOPORT
#define XL_RID                  XL_PCI_LOIO
#else
#define XL_RES                  SYS_RES_MEMORY
#define XL_RID                  XL_PCI_LOMEM
#endif

static device_method_t xl_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         xl_probe),
        DEVMETHOD(device_attach,        xl_attach),
        DEVMETHOD(device_detach,        xl_detach),
        DEVMETHOD(device_shutdown,      xl_shutdown),
        DEVMETHOD(device_suspend,       xl_suspend),
        DEVMETHOD(device_resume,        xl_resume),

        /* bus interface */
        DEVMETHOD(bus_print_child,      bus_generic_print_child),
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),

        /* MII interface */
        DEVMETHOD(miibus_readreg,       xl_miibus_readreg),
        DEVMETHOD(miibus_writereg,      xl_miibus_writereg),
        DEVMETHOD(miibus_statchg,       xl_miibus_statchg),
        DEVMETHOD(miibus_mediainit,     xl_miibus_mediainit),

        { 0, 0 }
};

static driver_t xl_driver = {
        "xl",
        xl_methods,
        sizeof(struct xl_softc)
};

static devclass_t xl_devclass;

DRIVER_MODULE(if_xl, pci, xl_driver, xl_devclass, 0, 0);
DRIVER_MODULE(miibus, xl, miibus_driver, miibus_devclass, 0, 0);

/*
 * Murphy's law says that it's possible the chip can wedge and
 * the 'command in progress' bit may never clear. Hence, we wait
 * only a finite amount of time to avoid getting caught in an
 * infinite loop. Normally this delay routine would be a macro,
 * but it isn't called during normal operation so we can afford
 * to make it a function.
 */
static void
xl_wait(sc)
        struct xl_softc         *sc;
{
        register int            i;

        for (i = 0; i < XL_TIMEOUT; i++) {
                if (!(CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY))
                        break;
        }

        if (i == XL_TIMEOUT)
                printf("xl%d: command never completed!\n", sc->xl_unit);

        return;
}

/*
 * MII access routines are provided for adapters with external
 * PHYs (3c905-TX, 3c905-T4, 3c905B-T4) and those with built-in
 * autoneg logic that's faked up to look like a PHY (3c905B-TX).
 * Note: if you don't perform the MDIO operations just right,
 * it's possible to end up with code that works correctly with
 * some chips/CPUs/processor speeds/bus speeds/etc but not
 * with others.
 */
#define MII_SET(x)                                      \
        CSR_WRITE_2(sc, XL_W4_PHY_MGMT,                 \
                CSR_READ_2(sc, XL_W4_PHY_MGMT) | x)

#define MII_CLR(x)                                      \
        CSR_WRITE_2(sc, XL_W4_PHY_MGMT,                 \
                CSR_READ_2(sc, XL_W4_PHY_MGMT) & ~x)

/*
 * Sync the PHYs by setting data bit and strobing the clock 32 times.
 */
static void
xl_mii_sync(sc)
        struct xl_softc         *sc;
{
        register int            i;

        XL_SEL_WIN(4);
        MII_SET(XL_MII_DIR|XL_MII_DATA);

        for (i = 0; i < 32; i++) {
                MII_SET(XL_MII_CLK);
                DELAY(1);
                MII_CLR(XL_MII_CLK);
                DELAY(1);
        }

        return;
}

/*
 * Clock a series of bits through the MII.
 */
static void
xl_mii_send(sc, bits, cnt)
        struct xl_softc         *sc;
        u_int32_t               bits;
        int                     cnt;
{
        int                     i;

        XL_SEL_WIN(4);
        MII_CLR(XL_MII_CLK);

        for (i = (0x1 << (cnt - 1)); i; i >>= 1) {
                if (bits & i) {
                        MII_SET(XL_MII_DATA);
                } else {
                        MII_CLR(XL_MII_DATA);
                }
                DELAY(1);
                MII_CLR(XL_MII_CLK);
                DELAY(1);
                MII_SET(XL_MII_CLK);
        }
}

/*
 * Read an PHY register through the MII.
 */
static int
xl_mii_readreg(sc, frame)
        struct xl_softc         *sc;
        struct xl_mii_frame     *frame;
        
{
        int                     i, ack, s;

        s = splimp();

        /*
         * Set up frame for RX.
         */
        frame->mii_stdelim = XL_MII_STARTDELIM;
        frame->mii_opcode = XL_MII_READOP;
        frame->mii_turnaround = 0;
        frame->mii_data = 0;
        
        /*
         * Select register window 4.
         */

        XL_SEL_WIN(4);

        CSR_WRITE_2(sc, XL_W4_PHY_MGMT, 0);
        /*
         * Turn on data xmit.
         */
        MII_SET(XL_MII_DIR);

        xl_mii_sync(sc);

        /*
         * Send command/address info.
         */
        xl_mii_send(sc, frame->mii_stdelim, 2);
        xl_mii_send(sc, frame->mii_opcode, 2);
        xl_mii_send(sc, frame->mii_phyaddr, 5);
        xl_mii_send(sc, frame->mii_regaddr, 5);

        /* Idle bit */
        MII_CLR((XL_MII_CLK|XL_MII_DATA));
        DELAY(1);
        MII_SET(XL_MII_CLK);
        DELAY(1);

        /* Turn off xmit. */
        MII_CLR(XL_MII_DIR);

        /* Check for ack */
        MII_CLR(XL_MII_CLK);
        DELAY(1);
        ack = CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA;
        MII_SET(XL_MII_CLK);
        DELAY(1);

        /*
         * Now try reading data bits. If the ack failed, we still
         * need to clock through 16 cycles to keep the PHY(s) in sync.
         */
        if (ack) {
                for(i = 0; i < 16; i++) {
                        MII_CLR(XL_MII_CLK);
                        DELAY(1);
                        MII_SET(XL_MII_CLK);
                        DELAY(1);
                }
                goto fail;
        }

        for (i = 0x8000; i; i >>= 1) {
                MII_CLR(XL_MII_CLK);
                DELAY(1);
                if (!ack) {
                        if (CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA)
                                frame->mii_data |= i;
                        DELAY(1);
                }
                MII_SET(XL_MII_CLK);
                DELAY(1);
        }

fail:

        MII_CLR(XL_MII_CLK);
        DELAY(1);
        MII_SET(XL_MII_CLK);
        DELAY(1);

        splx(s);

        if (ack)
                return(1);
        return(0);
}

/*
 * Write to a PHY register through the MII.
 */
static int
xl_mii_writereg(sc, frame)
        struct xl_softc         *sc;
        struct xl_mii_frame     *frame;
        
{
        int                     s;

        s = splimp();
        /*
         * Set up frame for TX.
         */

        frame->mii_stdelim = XL_MII_STARTDELIM;
        frame->mii_opcode = XL_MII_WRITEOP;
        frame->mii_turnaround = XL_MII_TURNAROUND;
        
        /*
         * Select the window 4.
         */
        XL_SEL_WIN(4);

        /*
         * Turn on data output.
         */
        MII_SET(XL_MII_DIR);

        xl_mii_sync(sc);

        xl_mii_send(sc, frame->mii_stdelim, 2);
        xl_mii_send(sc, frame->mii_opcode, 2);
        xl_mii_send(sc, frame->mii_phyaddr, 5);
        xl_mii_send(sc, frame->mii_regaddr, 5);
        xl_mii_send(sc, frame->mii_turnaround, 2);
        xl_mii_send(sc, frame->mii_data, 16);

        /* Idle bit. */
        MII_SET(XL_MII_CLK);
        DELAY(1);
        MII_CLR(XL_MII_CLK);
        DELAY(1);

        /*
         * Turn off xmit.
         */
        MII_CLR(XL_MII_DIR);

        splx(s);

        return(0);
}

static int
xl_miibus_readreg(dev, phy, reg)
        device_t                dev;
        int                     phy, reg;
{
        struct xl_softc         *sc;
        struct xl_mii_frame     frame;

        sc = device_get_softc(dev);

        /*
         * Pretend that PHYs are only available at MII address 24.
         * This is to guard against problems with certain 3Com ASIC
         * revisions that incorrectly map the internal transceiver
         * control registers at all MII addresses. This can cause
         * the miibus code to attach the same PHY several times over.
         */
        if ((!(sc->xl_flags & XL_FLAG_PHYOK)) && phy != 24)
                return(0);

        bzero((char *)&frame, sizeof(frame));

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        xl_mii_readreg(sc, &frame);

        return(frame.mii_data);
}

static int
xl_miibus_writereg(dev, phy, reg, data)
        device_t                dev;
        int                     phy, reg, data;
{
        struct xl_softc         *sc;
        struct xl_mii_frame     frame;

        sc = device_get_softc(dev);

        if ((!(sc->xl_flags & XL_FLAG_PHYOK)) && phy != 24)
                return(0);

        bzero((char *)&frame, sizeof(frame));

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        frame.mii_data = data;

        xl_mii_writereg(sc, &frame);

        return(0);
}

static void
xl_miibus_statchg(dev)
        device_t                dev;
{
        struct xl_softc         *sc;
        struct mii_data         *mii;

        
        sc = device_get_softc(dev);
        mii = device_get_softc(sc->xl_miibus);

        xl_setcfg(sc);

        /* Set ASIC's duplex mode to match the PHY. */
        XL_SEL_WIN(3);
        if ((mii->mii_media_active & IFM_GMASK) == IFM_FDX)
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL, XL_MACCTRL_DUPLEX);
        else
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL,
                        (CSR_READ_1(sc, XL_W3_MAC_CTRL) & ~XL_MACCTRL_DUPLEX));

        return;
}

/*
 * Special support for the 3c905B-COMBO. This card has 10/100 support
 * plus BNC and AUI ports. This means we will have both an miibus attached
 * plus some non-MII media settings. In order to allow this, we have to
 * add the extra media to the miibus's ifmedia struct, but we can't do
 * that during xl_attach() because the miibus hasn't been attached yet.
 * So instead, we wait until the miibus probe/attach is done, at which
 * point we will get a callback telling is that it's safe to add our
 * extra media.
 */
static void
xl_miibus_mediainit(dev)
        device_t                dev;
{
        struct xl_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;
        
        sc = device_get_softc(dev);
        mii = device_get_softc(sc->xl_miibus);
        ifm = &mii->mii_media;

        if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                /*
                 * Check for a 10baseFL board in disguise.
                 */
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        if (bootverbose)
                                printf("xl%d: found 10baseFL\n", sc->xl_unit);
                        ifmedia_add(ifm, IFM_ETHER|IFM_10_FL, 0, NULL);
                        ifmedia_add(ifm, IFM_ETHER|IFM_10_FL|IFM_HDX, 0, NULL);
                        if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                ifmedia_add(ifm,
                                    IFM_ETHER|IFM_10_FL|IFM_FDX, 0, NULL);
                } else {
                        if (bootverbose)
                                printf("xl%d: found AUI\n", sc->xl_unit);
                        ifmedia_add(ifm, IFM_ETHER|IFM_10_5, 0, NULL);
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (bootverbose)
                        printf("xl%d: found BNC\n", sc->xl_unit);
                ifmedia_add(ifm, IFM_ETHER|IFM_10_2, 0, NULL);
        }

        return;
}

/*
 * The EEPROM is slow: give it time to come ready after issuing
 * it a command.
 */
static int
xl_eeprom_wait(sc)
        struct xl_softc         *sc;
{
        int                     i;

        for (i = 0; i < 100; i++) {
                if (CSR_READ_2(sc, XL_W0_EE_CMD) & XL_EE_BUSY)
                        DELAY(162);
                else
                        break;
        }

        if (i == 100) {
                printf("xl%d: eeprom failed to come ready\n", sc->xl_unit);
                return(1);
        }

        return(0);
}

/*
 * Read a sequence of words from the EEPROM. Note that ethernet address
 * data is stored in the EEPROM in network byte order.
 */
static int
xl_read_eeprom(sc, dest, off, cnt, swap)
        struct xl_softc         *sc;
        caddr_t                 dest;
        int                     off;
        int                     cnt;
        int                     swap;
{
        int                     err = 0, i;
        u_int16_t               word = 0, *ptr;
#define EEPROM_5BIT_OFFSET(A) ((((A) << 2) & 0x7F00) | ((A) & 0x003F))
#define EEPROM_8BIT_OFFSET(A) ((A) & 0x003F)
        /* WARNING! DANGER!
         * It's easy to accidentally overwrite the rom content!
         * Note: the 3c575 uses 8bit EEPROM offsets.
         */
        XL_SEL_WIN(0);

        if (xl_eeprom_wait(sc))
                return(1);

        if (sc->xl_flags & XL_FLAG_EEPROM_OFFSET_30)
                off += 0x30;

        for (i = 0; i < cnt; i++) {
                if (sc->xl_flags & XL_FLAG_8BITROM)
                        CSR_WRITE_2(sc, XL_W0_EE_CMD, 
                            XL_EE_8BIT_READ | EEPROM_8BIT_OFFSET(off + i));
                else
                        CSR_WRITE_2(sc, XL_W0_EE_CMD,
                            XL_EE_READ | EEPROM_5BIT_OFFSET(off + i));
                err = xl_eeprom_wait(sc);
                if (err)
                        break;
                word = CSR_READ_2(sc, XL_W0_EE_DATA);
                ptr = (u_int16_t *)(dest + (i * 2));
                if (swap)
                        *ptr = ntohs(word);
                else
                        *ptr = word;    
        }

        return(err ? 1 : 0);
}

/*
 * This routine is taken from the 3Com Etherlink XL manual,
 * page 10-7. It calculates a CRC of the supplied multicast
 * group address and returns the lower 8 bits, which are used
 * as the multicast filter position.
 * Note: the 3c905B currently only supports a 64-bit hash table,
 * which means we really only need 6 bits, but the manual indicates
 * that future chip revisions will have a 256-bit hash table,
 * hence the routine is set up to calculate 8 bits of position
 * info in case we need it some day.
 * Note II, The Sequel: _CURRENT_ versions of the 3c905B have a
 * 256 bit hash table. This means we have to use all 8 bits regardless.
 * On older cards, the upper 2 bits will be ignored. Grrrr....
 */
static u_int8_t xl_calchash(addr)
        caddr_t                 addr;
{
        u_int32_t               crc, carry;
        int                     i, j;
        u_int8_t                c;

        /* Compute CRC for the address value. */
        crc = 0xFFFFFFFF; /* initial value */

        for (i = 0; i < 6; i++) {
                c = *(addr + i);
                for (j = 0; j < 8; j++) {
                        carry = ((crc & 0x80000000) ? 1 : 0) ^ (c & 0x01);
                        crc <<= 1;
                        c >>= 1;
                        if (carry)
                                crc = (crc ^ 0x04c11db6) | carry;
                }
        }

        /* return the filter bit position */
        return(crc & 0x000000FF);
}

/*
 * NICs older than the 3c905B have only one multicast option, which
 * is to enable reception of all multicast frames.
 */
static void
xl_setmulti(sc)
        struct xl_softc         *sc;
{
        struct ifnet            *ifp;
        struct ifmultiaddr      *ifma;
        u_int8_t                rxfilt;
        int                     mcnt = 0;

        ifp = &sc->arpcom.ac_if;

        XL_SEL_WIN(5);
        rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);

        if (ifp->if_flags & IFF_ALLMULTI) {
                rxfilt |= XL_RXFILTER_ALLMULTI;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
                return;
        }

        for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
                                ifma = ifma->ifma_link.le_next)
                mcnt++;

        if (mcnt)
                rxfilt |= XL_RXFILTER_ALLMULTI;
        else
                rxfilt &= ~XL_RXFILTER_ALLMULTI;

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);

        return;
}

/*
 * 3c905B adapters have a hash filter that we can program.
 */
static void
xl_setmulti_hash(sc)
        struct xl_softc         *sc;
{
        struct ifnet            *ifp;
        int                     h = 0, i;
        struct ifmultiaddr      *ifma;
        u_int8_t                rxfilt;
        int                     mcnt = 0;

        ifp = &sc->arpcom.ac_if;

        XL_SEL_WIN(5);
        rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);

        if (ifp->if_flags & IFF_ALLMULTI) {
                rxfilt |= XL_RXFILTER_ALLMULTI;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
                return;
        } else
                rxfilt &= ~XL_RXFILTER_ALLMULTI;


        /* first, zot all the existing hash bits */
        for (i = 0; i < XL_HASHFILT_SIZE; i++)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH|i);

        /* now program new ones */
        for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
                                ifma = ifma->ifma_link.le_next) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                h = xl_calchash(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH|XL_HASH_SET|h);
                mcnt++;
        }

        if (mcnt)
                rxfilt |= XL_RXFILTER_MULTIHASH;
        else
                rxfilt &= ~XL_RXFILTER_MULTIHASH;

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);

        return;
}

#ifdef notdef
static void
xl_testpacket(sc)
        struct xl_softc         *sc;
{
        struct mbuf             *m;
        struct ifnet            *ifp;

        ifp = &sc->arpcom.ac_if;

        MGETHDR(m, M_DONTWAIT, MT_DATA);

        if (m == NULL)
                return;

        bcopy(&sc->arpcom.ac_enaddr,
                mtod(m, struct ether_header *)->ether_dhost, ETHER_ADDR_LEN);
        bcopy(&sc->arpcom.ac_enaddr,
                mtod(m, struct ether_header *)->ether_shost, ETHER_ADDR_LEN);
        mtod(m, struct ether_header *)->ether_type = htons(3);
        mtod(m, unsigned char *)[14] = 0;
        mtod(m, unsigned char *)[15] = 0;
        mtod(m, unsigned char *)[16] = 0xE3;
        m->m_len = m->m_pkthdr.len = sizeof(struct ether_header) + 3;
        IF_ENQUEUE(&ifp->if_snd, m);
        xl_start(ifp);

        return;
}
#endif

static void
xl_setcfg(sc)
        struct xl_softc         *sc;
{
        u_int32_t               icfg;

        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);
        icfg &= ~XL_ICFG_CONNECTOR_MASK;
        if (sc->xl_media & XL_MEDIAOPT_MII ||
                sc->xl_media & XL_MEDIAOPT_BT4)
                icfg |= (XL_XCVR_MII << XL_ICFG_CONNECTOR_BITS);
        if (sc->xl_media & XL_MEDIAOPT_BTX)
                icfg |= (XL_XCVR_AUTO << XL_ICFG_CONNECTOR_BITS);

        CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);

        return;
}

static void
xl_setmode(sc, media)
        struct xl_softc         *sc;
        int                     media;
{
        u_int32_t               icfg;
        u_int16_t               mediastat;

        printf("xl%d: selecting ", sc->xl_unit);

        XL_SEL_WIN(4);
        mediastat = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);

        if (sc->xl_media & XL_MEDIAOPT_BT) {
                if (IFM_SUBTYPE(media) == IFM_10_T) {
                        printf("10baseT transceiver, ");
                        sc->xl_xcvr = XL_XCVR_10BT;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_10BT << XL_ICFG_CONNECTOR_BITS);
                        mediastat |= XL_MEDIASTAT_LINKBEAT|
                                        XL_MEDIASTAT_JABGUARD;
                        mediastat &= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BFX) {
                if (IFM_SUBTYPE(media) == IFM_100_FX) {
                        printf("100baseFX port, ");
                        sc->xl_xcvr = XL_XCVR_100BFX;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_100BFX << XL_ICFG_CONNECTOR_BITS);
                        mediastat |= XL_MEDIASTAT_LINKBEAT;
                        mediastat &= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                if (IFM_SUBTYPE(media) == IFM_10_5) {
                        printf("AUI port, ");
                        sc->xl_xcvr = XL_XCVR_AUI;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                        XL_MEDIASTAT_JABGUARD);
                        mediastat |= ~XL_MEDIASTAT_SQEENB;
                }
                if (IFM_SUBTYPE(media) == IFM_10_FL) {
                        printf("10baseFL transceiver, ");
                        sc->xl_xcvr = XL_XCVR_AUI;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                        XL_MEDIASTAT_JABGUARD);
                        mediastat |= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (IFM_SUBTYPE(media) == IFM_10_2) {
                        printf("BNC port, ");
                        sc->xl_xcvr = XL_XCVR_COAX;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_COAX << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                        XL_MEDIASTAT_JABGUARD|
                                        XL_MEDIASTAT_SQEENB);
                }
        }

        if ((media & IFM_GMASK) == IFM_FDX ||
                        IFM_SUBTYPE(media) == IFM_100_FX) {
                printf("full duplex\n");
                XL_SEL_WIN(3);
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL, XL_MACCTRL_DUPLEX);
        } else {
                printf("half duplex\n");
                XL_SEL_WIN(3);
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL,
                        (CSR_READ_1(sc, XL_W3_MAC_CTRL) & ~XL_MACCTRL_DUPLEX));
        }

        if (IFM_SUBTYPE(media) == IFM_10_2)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
        else
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
        CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
        XL_SEL_WIN(4);
        CSR_WRITE_2(sc, XL_W4_MEDIA_STATUS, mediastat);
        DELAY(800);
        XL_SEL_WIN(7);

        return;
}

static void
xl_reset(sc)
        struct xl_softc         *sc;
{
        register int            i;

        XL_SEL_WIN(0);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RESET | 
                    ((sc->xl_flags & XL_FLAG_WEIRDRESET) ?
                     XL_RESETOPT_DISADVFD:0));

        for (i = 0; i < XL_TIMEOUT; i++) {
                DELAY(10);
                if (!(CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY))
                        break;
        }

        if (i == XL_TIMEOUT)
                printf("xl%d: reset didn't complete\n", sc->xl_unit);

        /* Reset TX and RX. */
        /* Note: the RX reset takes an absurd amount of time
         * on newer versions of the Tornado chips such as those
         * on the 3c905CX and newer 3c908C cards. We wait an    
         * extra amount of time so that xl_wait() doesn't complain
         * and annoy the users.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        DELAY(100000);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);

        if (sc->xl_flags & XL_FLAG_INVERT_LED_PWR || 
            sc->xl_flags & XL_FLAG_INVERT_MII_PWR) {
                XL_SEL_WIN(2);
                CSR_WRITE_2(sc, XL_W2_RESET_OPTIONS, CSR_READ_2(sc,
                    XL_W2_RESET_OPTIONS) 
                    | ((sc->xl_flags & XL_FLAG_INVERT_LED_PWR)?XL_RESETOPT_INVERT_LED:0)
                    | ((sc->xl_flags & XL_FLAG_INVERT_MII_PWR)?XL_RESETOPT_INVERT_MII:0)
                    );
        }

        /* Wait a little while for the chip to get its brains in order. */
        DELAY(100000);
        return;
}

/*
 * Probe for a 3Com Etherlink XL chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 */
static int
xl_probe(dev)
        device_t                dev;
{
        struct xl_type          *t;

        t = xl_devs;

        while(t->xl_name != NULL) {
                if ((pci_get_vendor(dev) == t->xl_vid) &&
                    (pci_get_device(dev) == t->xl_did)) {
                        device_set_desc(dev, t->xl_name);
                        return(0);
                }
                t++;
        }

        return(ENXIO);
}

/*
 * This routine is a kludge to work around possible hardware faults
 * or manufacturing defects that can cause the media options register
 * (or reset options register, as it's called for the first generation
 * 3c90x adapters) to return an incorrect result. I have encountered
 * one Dell Latitude laptop docking station with an integrated 3c905-TX
 * which doesn't have any of the 'mediaopt' bits set. This screws up
 * the attach routine pretty badly because it doesn't know what media
 * to look for. If we find ourselves in this predicament, this routine
 * will try to guess the media options values and warn the user of a
 * possible manufacturing defect with his adapter/system/whatever.
 */
static void
xl_mediacheck(sc)
        struct xl_softc         *sc;
{

        /*
         * If some of the media options bits are set, assume they are
         * correct. If not, try to figure it out down below.
         * XXX I should check for 10baseFL, but I don't have an adapter
         * to test with.
         */
        if (sc->xl_media & (XL_MEDIAOPT_MASK & ~XL_MEDIAOPT_VCO)) {
                /*
                 * Check the XCVR value. If it's not in the normal range
                 * of values, we need to fake it up here.
                 */
                if (sc->xl_xcvr <= XL_XCVR_AUTO)
                        return;
                else {
                        printf("xl%d: bogus xcvr value "
                        "in EEPROM (%x)\n", sc->xl_unit, sc->xl_xcvr);
                        printf("xl%d: choosing new default based "
                                "on card type\n", sc->xl_unit);
                }
        } else {
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media & XL_MEDIAOPT_10FL)
                        return;
                printf("xl%d: WARNING: no media options bits set in "
                        "the media options register!!\n", sc->xl_unit);
                printf("xl%d: this could be a manufacturing defect in "
                        "your adapter or system\n", sc->xl_unit);
                printf("xl%d: attempting to guess media type; you "
                        "should probably consult your vendor\n", sc->xl_unit);
        }

        xl_choose_xcvr(sc, 1);

        return;
}

static void
xl_choose_xcvr(sc, verbose)
        struct xl_softc         *sc;
        int                     verbose;
{
        u_int16_t               devid;

        /*
         * Read the device ID from the EEPROM.
         * This is what's loaded into the PCI device ID register, so it has
         * to be correct otherwise we wouldn't have gotten this far.
         */
        xl_read_eeprom(sc, (caddr_t)&devid, XL_EE_PRODID, 1, 0);

        switch(devid) {
        case TC_DEVICEID_BOOMERANG_10BT:        /* 3c900-TPO */
        case TC_DEVICEID_KRAKATOA_10BT:         /* 3c900B-TPO */
                sc->xl_media = XL_MEDIAOPT_BT;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        printf("xl%d: guessing 10BaseT "
                            "transceiver\n", sc->xl_unit);
                break;
        case TC_DEVICEID_BOOMERANG_10BT_COMBO:  /* 3c900-COMBO */
        case TC_DEVICEID_KRAKATOA_10BT_COMBO:   /* 3c900B-COMBO */
                sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        printf("xl%d: guessing COMBO "
                            "(AUI/BNC/TP)\n", sc->xl_unit);
                break;
        case TC_DEVICEID_KRAKATOA_10BT_TPC:     /* 3c900B-TPC */
                sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        printf("xl%d: guessing TPC (BNC/TP)\n", sc->xl_unit);
                break;
        case TC_DEVICEID_CYCLONE_10FL:          /* 3c900B-FL */
                sc->xl_media = XL_MEDIAOPT_10FL;
                sc->xl_xcvr = XL_XCVR_AUI;
                if (verbose)
                        printf("xl%d: guessing 10baseFL\n", sc->xl_unit);
                break;
        case TC_DEVICEID_BOOMERANG_10_100BT:    /* 3c905-TX */
        case TC_DEVICEID_HURRICANE_555:         /* 3c555 */
        case TC_DEVICEID_HURRICANE_556:         /* 3c556 */
        case TC_DEVICEID_HURRICANE_556B:        /* 3c556B */
        case TC_DEVICEID_HURRICANE_575A:        /* 3c575TX */
        case TC_DEVICEID_HURRICANE_575B:        /* 3c575B */
        case TC_DEVICEID_HURRICANE_575C:        /* 3c575C */
        case TC_DEVICEID_HURRICANE_656:         /* 3c656 */
        case TC_DEVICEID_HURRICANE_656B:        /* 3c656B */
        case TC_DEVICEID_TORNADO_656C:          /* 3c656C */
        case TC_DEVICEID_TORNADO_10_100BT_920B: /* 3c920B-EMB */
                sc->xl_media = XL_MEDIAOPT_MII;
                sc->xl_xcvr = XL_XCVR_MII;
                if (verbose)
                        printf("xl%d: guessing MII\n", sc->xl_unit);
                break;
        case TC_DEVICEID_BOOMERANG_100BT4:      /* 3c905-T4 */
        case TC_DEVICEID_CYCLONE_10_100BT4:     /* 3c905B-T4 */
                sc->xl_media = XL_MEDIAOPT_BT4;
                sc->xl_xcvr = XL_XCVR_MII;
                if (verbose)
                        printf("xl%d: guessing 100BaseT4/MII\n", sc->xl_unit);
                break;
        case TC_DEVICEID_HURRICANE_10_100BT:    /* 3c905B-TX */
        case TC_DEVICEID_HURRICANE_10_100BT_SERV:/*3c980-TX */
        case TC_DEVICEID_TORNADO_10_100BT_SERV: /* 3c980C-TX */
        case TC_DEVICEID_HURRICANE_SOHO100TX:   /* 3cSOHO100-TX */
        case TC_DEVICEID_TORNADO_10_100BT:      /* 3c905C-TX */
        case TC_DEVICEID_TORNADO_HOMECONNECT:   /* 3c450-TX */
                sc->xl_media = XL_MEDIAOPT_BTX;
                sc->xl_xcvr = XL_XCVR_AUTO;
                if (verbose)
                        printf("xl%d: guessing 10/100 internal\n", sc->xl_unit);
                break;
        case TC_DEVICEID_CYCLONE_10_100_COMBO:  /* 3c905B-COMBO */
                sc->xl_media = XL_MEDIAOPT_BTX|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                sc->xl_xcvr = XL_XCVR_AUTO;
                if (verbose)
                        printf("xl%d: guessing 10/100 "
                            "plus BNC/AUI\n", sc->xl_unit);
                break;
        default:
                printf("xl%d: unknown device ID: %x -- "
                        "defaulting to 10baseT\n", sc->xl_unit, devid);
                sc->xl_media = XL_MEDIAOPT_BT;
                break;
        }

        return;
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
xl_attach(dev)
        device_t                dev;
{
        int                     s;
        u_char                  eaddr[ETHER_ADDR_LEN];
        u_int32_t               command;
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        int                     media = IFM_ETHER|IFM_100_TX|IFM_FDX;
        int                     unit, error = 0, rid;

        s = splimp();

        sc = device_get_softc(dev);
        unit = device_get_unit(dev);

        sc->xl_flags = 0;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_555)
                sc->xl_flags |= XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_PHYOK;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_556 ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_556B)
                sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK |
                    XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_WEIRDRESET |
                    XL_FLAG_INVERT_LED_PWR | XL_FLAG_INVERT_MII_PWR;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_555 ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_556)
                sc->xl_flags |= XL_FLAG_8BITROM;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_556B)
                sc->xl_flags |= XL_FLAG_NO_XCVR_PWR;

        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575A ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_575B ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_575C ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_656B ||
            pci_get_device(dev) == TC_DEVICEID_TORNADO_656C)
                sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK |
                    XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_8BITROM;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_656)
                sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575B)
                sc->xl_flags |= XL_FLAG_INVERT_LED_PWR;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575C)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
        if (pci_get_device(dev) == TC_DEVICEID_TORNADO_656C)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
        if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_656 ||
            pci_get_device(dev) == TC_DEVICEID_HURRICANE_656B)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR |
                    XL_FLAG_INVERT_LED_PWR;
        if (pci_get_device(dev) == TC_DEVICEID_TORNADO_10_100BT_920B)
                sc->xl_flags |= XL_FLAG_PHYOK;

        /*
         * If this is a 3c905B, we have to check one extra thing.
         * The 905B supports power management and may be placed in
         * a low-power mode (D3 mode), typically by certain operating
         * systems which shall not be named. The PCI BIOS is supposed
         * to reset the NIC and bring it out of low-power mode, but
         * some do not. Consequently, we have to see if this chip
         * supports power management, and if so, make sure it's not
         * in low-power mode. If power management is available, the
         * capid byte will be 0x01.
         *
         * I _think_ that what actually happens is that the chip
         * loses its PCI configuration during the transition from
         * D3 back to D0; this means that it should be possible for
         * us to save the PCI iobase, membase and IRQ, put the chip
         * back in the D0 state, then restore the PCI config ourselves.
         */

        if (pci_get_powerstate(dev) != PCI_POWERSTATE_D0) {
                u_int32_t               iobase, membase, irq;

                /* Save important PCI config data. */
                iobase = pci_read_config(dev, XL_PCI_LOIO, 4);
                membase = pci_read_config(dev, XL_PCI_LOMEM, 4);
                irq = pci_read_config(dev, XL_PCI_INTLINE, 4);

                /* Reset the power state. */
                printf("xl%d: chip is in D%d power mode "
                    "-- setting to D0\n", unit,
                    pci_get_powerstate(dev));

                pci_set_powerstate(dev, PCI_POWERSTATE_D0);

                /* Restore PCI config data. */
                pci_write_config(dev, XL_PCI_LOIO, iobase, 4);
                pci_write_config(dev, XL_PCI_LOMEM, membase, 4);
                pci_write_config(dev, XL_PCI_INTLINE, irq, 4);
        }

        /*
         * Map control/status registers.
         */
        pci_enable_busmaster(dev);
        pci_enable_io(dev, SYS_RES_IOPORT);
        pci_enable_io(dev, SYS_RES_MEMORY);
        command = pci_read_config(dev, PCIR_COMMAND, 4);

#ifdef XL_USEIOSPACE
        if (!(command & PCIM_CMD_PORTEN)) {
                printf("xl%d: failed to enable I/O ports!\n", unit);
                error = ENXIO;
                goto fail;
        }
#else
        if (!(command & PCIM_CMD_MEMEN)) {
                printf("xl%d: failed to enable memory mapping!\n", unit);
                error = ENXIO;
                goto fail;
        }
#endif

        rid = XL_RID;
        sc->xl_res = bus_alloc_resource(dev, XL_RES, &rid,
            0, ~0, 1, RF_ACTIVE);

        if (sc->xl_res == NULL) {
                printf ("xl%d: couldn't map ports/memory\n", unit);
                error = ENXIO;
                goto fail;
        }

        sc->xl_btag = rman_get_bustag(sc->xl_res);
        sc->xl_bhandle = rman_get_bushandle(sc->xl_res);

        if (sc->xl_flags & XL_FLAG_FUNCREG) {
                rid = XL_PCI_FUNCMEM;
                sc->xl_fres = bus_alloc_resource(dev, SYS_RES_MEMORY, &rid,
                    0, ~0, 1, RF_ACTIVE);

                if (sc->xl_fres == NULL) {
                        printf ("xl%d: couldn't map ports/memory\n", unit);
                        bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                        error = ENXIO;
                        goto fail;
                }

                sc->xl_ftag = rman_get_bustag(sc->xl_fres);
                sc->xl_fhandle = rman_get_bushandle(sc->xl_fres);
        }

        rid = 0;
        sc->xl_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
            RF_SHAREABLE | RF_ACTIVE);

        if (sc->xl_irq == NULL) {
                printf("xl%d: couldn't map interrupt\n", unit);
                if (sc->xl_fres != NULL)
                        bus_release_resource(dev, SYS_RES_MEMORY,
                            XL_PCI_FUNCMEM, sc->xl_fres);
                bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                error = ENXIO;
                goto fail;
        }

        error = bus_setup_intr(dev, sc->xl_irq, INTR_TYPE_NET,
            xl_intr, sc, &sc->xl_intrhand);

        if (error) {
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                if (sc->xl_fres != NULL)
                        bus_release_resource(dev, SYS_RES_MEMORY,
                            XL_PCI_FUNCMEM, sc->xl_fres);
                bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                printf("xl%d: couldn't set up irq\n", unit);
                goto fail;
        }

        /* Reset the adapter. */
        xl_reset(sc);

        /*
         * Get station address from the EEPROM.
         */
        if (xl_read_eeprom(sc, (caddr_t)&eaddr, XL_EE_OEM_ADR0, 3, 1)) {
                printf("xl%d: failed to read station address\n", sc->xl_unit);
                bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                if (sc->xl_fres != NULL)
                        bus_release_resource(dev, SYS_RES_MEMORY,
                            XL_PCI_FUNCMEM, sc->xl_fres);
                bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                error = ENXIO;
                goto fail;
        }

        /*
         * A 3Com chip was detected. Inform the world.
         */
        printf("xl%d: Ethernet address: %6D\n", unit, eaddr, ":");

        sc->xl_unit = unit;
        callout_handle_init(&sc->xl_stat_ch);
        bcopy(eaddr, (char *)&sc->arpcom.ac_enaddr, ETHER_ADDR_LEN);

        sc->xl_ldata = contigmalloc(sizeof(struct xl_list_data), M_DEVBUF,
            M_NOWAIT, 0, 0xffffffff, PAGE_SIZE, 0);

        if (sc->xl_ldata == NULL) {
                printf("xl%d: no memory for list buffers!\n", unit);
                bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                if (sc->xl_fres != NULL)
                        bus_release_resource(dev, SYS_RES_MEMORY,
                            XL_PCI_FUNCMEM, sc->xl_fres);
                bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                error = ENXIO;
                goto fail;
        }

        bzero(sc->xl_ldata, sizeof(struct xl_list_data));

        /*
         * Figure out the card type. 3c905B adapters have the
         * 'supportsNoTxLength' bit set in the capabilities
         * word in the EEPROM.
         */
        xl_read_eeprom(sc, (caddr_t)&sc->xl_caps, XL_EE_CAPS, 1, 0);
        if (sc->xl_caps & XL_CAPS_NO_TXLENGTH)
                sc->xl_type = XL_TYPE_905B;
        else
                sc->xl_type = XL_TYPE_90X;

        ifp = &sc->arpcom.ac_if;
        ifp->if_softc = sc;
        ifp->if_unit = unit;
        ifp->if_name = "xl";
        ifp->if_mtu = ETHERMTU;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = xl_ioctl;
        ifp->if_output = ether_output;
        if (sc->xl_type == XL_TYPE_905B) {
                ifp->if_start = xl_start_90xB;
                ifp->if_hwassist = XL905B_CSUM_FEATURES;
                ifp->if_capabilities = IFCAP_HWCSUM;
        } else
                ifp->if_start = xl_start;
        ifp->if_watchdog = xl_watchdog;
        ifp->if_init = xl_init;
        ifp->if_baudrate = 10000000;
        ifp->if_snd.ifq_maxlen = XL_TX_LIST_CNT - 1;
        ifp->if_capenable = ifp->if_capabilities;

        /*
         * Now we have to see what sort of media we have.
         * This includes probing for an MII interace and a
         * possible PHY.
         */
        XL_SEL_WIN(3);
        sc->xl_media = CSR_READ_2(sc, XL_W3_MEDIA_OPT);
        if (bootverbose)
                printf("xl%d: media options word: %x\n", sc->xl_unit,
                                                         sc->xl_media);

        xl_read_eeprom(sc, (char *)&sc->xl_xcvr, XL_EE_ICFG_0, 2, 0);
        sc->xl_xcvr &= XL_ICFG_CONNECTOR_MASK;
        sc->xl_xcvr >>= XL_ICFG_CONNECTOR_BITS;

        xl_mediacheck(sc);

        if (sc->xl_media & XL_MEDIAOPT_MII || sc->xl_media & XL_MEDIAOPT_BTX
                        || sc->xl_media & XL_MEDIAOPT_BT4) {
                if (bootverbose)
                        printf("xl%d: found MII/AUTO\n", sc->xl_unit);
                xl_setcfg(sc);
                if (mii_phy_probe(dev, &sc->xl_miibus,
                    xl_ifmedia_upd, xl_ifmedia_sts)) {
                        printf("xl%d: no PHY found!\n", sc->xl_unit);
                        bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                        bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                        bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                        contigfree(sc->xl_ldata,
                            sizeof(struct xl_list_data), M_DEVBUF);
                        error = ENXIO;
                        goto fail;
                }

                goto done;
        }

        /*
         * Sanity check. If the user has selected "auto" and this isn't
         * a 10/100 card of some kind, we need to force the transceiver
         * type to something sane.
         */
        if (sc->xl_xcvr == XL_XCVR_AUTO)
                xl_choose_xcvr(sc, bootverbose);

        /*
         * Do ifmedia setup.
         */

        ifmedia_init(&sc->ifmedia, 0, xl_ifmedia_upd, xl_ifmedia_sts);

        if (sc->xl_media & XL_MEDIAOPT_BT) {
                if (bootverbose)
                        printf("xl%d: found 10baseT\n", sc->xl_unit);
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T, 0, NULL);
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T|IFM_HDX, 0, NULL);
                if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                        ifmedia_add(&sc->ifmedia,
                            IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
        }

        if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                /*
                 * Check for a 10baseFL board in disguise.
                 */
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        if (bootverbose)
                                printf("xl%d: found 10baseFL\n", sc->xl_unit);
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL, 0, NULL);
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL|IFM_HDX,
                            0, NULL);
                        if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                ifmedia_add(&sc->ifmedia,
                                    IFM_ETHER|IFM_10_FL|IFM_FDX, 0, NULL);
                } else {
                        if (bootverbose)
                                printf("xl%d: found AUI\n", sc->xl_unit);
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_5, 0, NULL);
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (bootverbose)
                        printf("xl%d: found BNC\n", sc->xl_unit);
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_2, 0, NULL);
        }

        if (sc->xl_media & XL_MEDIAOPT_BFX) {
                if (bootverbose)
                        printf("xl%d: found 100baseFX\n", sc->xl_unit);
                ifp->if_baudrate = 100000000;
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_100_FX, 0, NULL);
        }

        /* Choose a default media. */
        switch(sc->xl_xcvr) {
        case XL_XCVR_10BT:
                media = IFM_ETHER|IFM_10_T;
                xl_setmode(sc, media);
                break;
        case XL_XCVR_AUI:
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        media = IFM_ETHER|IFM_10_FL;
                        xl_setmode(sc, media);
                } else {
                        media = IFM_ETHER|IFM_10_5;
                        xl_setmode(sc, media);
                }
                break;
        case XL_XCVR_COAX:
                media = IFM_ETHER|IFM_10_2;
                xl_setmode(sc, media);
                break;
        case XL_XCVR_AUTO:
        case XL_XCVR_100BTX:
        case XL_XCVR_MII:
                /* Chosen by miibus */
                break;
        case XL_XCVR_100BFX:
                media = IFM_ETHER|IFM_100_FX;
                break;
        default:
                printf("xl%d: unknown XCVR type: %d\n", sc->xl_unit,
                                                        sc->xl_xcvr);
                /*
                 * This will probably be wrong, but it prevents
                 * the ifmedia code from panicking.
                 */
                media = IFM_ETHER|IFM_10_T;
                break;
        }

        if (sc->xl_miibus == NULL)
                ifmedia_set(&sc->ifmedia, media);

done:

        if (sc->xl_flags & XL_FLAG_NO_XCVR_PWR) {
                XL_SEL_WIN(0);
                CSR_WRITE_2(sc, XL_W0_MFG_ID, XL_NO_XCVR_PWR_MAGICBITS);
        }

        /*
         * Call MI attach routine.
         */
        ether_ifattach(ifp, ETHER_BPF_SUPPORTED);

fail:
        splx(s);
        return(error);
}

static int
xl_detach(dev)
        device_t                dev;
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        int                     s;

        s = splimp();

        sc = device_get_softc(dev);
        ifp = &sc->arpcom.ac_if;

        xl_reset(sc);
        xl_stop(sc);
        ether_ifdetach(ifp, ETHER_BPF_SUPPORTED);

        /* Delete any miibus and phy devices attached to this interface */
        if (sc->xl_miibus != NULL) {
                bus_generic_detach(dev);
                device_delete_child(dev, sc->xl_miibus);
        }

        bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
        bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
        if (sc->xl_fres != NULL)
                bus_release_resource(dev, SYS_RES_MEMORY,
                    XL_PCI_FUNCMEM, sc->xl_fres);
        bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);

        ifmedia_removeall(&sc->ifmedia);
        contigfree(sc->xl_ldata, sizeof(struct xl_list_data), M_DEVBUF);

        splx(s);

        return(0);
}

/*
 * Initialize the transmit descriptors.
 */
static int
xl_list_tx_init(sc)
        struct xl_softc         *sc;
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     i;

        cd = &sc->xl_cdata;
        ld = sc->xl_ldata;
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                if (i == (XL_TX_LIST_CNT - 1))
                        cd->xl_tx_chain[i].xl_next = NULL;
                else
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
        }

        cd->xl_tx_free = &cd->xl_tx_chain[0];
        cd->xl_tx_tail = cd->xl_tx_head = NULL;

        return(0);
}

/*
 * Initialize the transmit descriptors.
 */
static int xl_list_tx_init_90xB(sc)
        struct xl_softc         *sc;
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     i;

        cd = &sc->xl_cdata;
        ld = sc->xl_ldata;
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                cd->xl_tx_chain[i].xl_phys = vtophys(&ld->xl_tx_list[i]);
                if (i == (XL_TX_LIST_CNT - 1))
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[0];
                else
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
                if (i == 0)
                        cd->xl_tx_chain[i].xl_prev =
                            &cd->xl_tx_chain[XL_TX_LIST_CNT - 1];
                else
                        cd->xl_tx_chain[i].xl_prev =
                            &cd->xl_tx_chain[i - 1];
        }

        bzero((char *)ld->xl_tx_list,
            sizeof(struct xl_list) * XL_TX_LIST_CNT);
        ld->xl_tx_list[0].xl_status = XL_TXSTAT_EMPTY;

        cd->xl_tx_prod = 1;
        cd->xl_tx_cons = 1;
        cd->xl_tx_cnt = 0;

        return(0);
}

/*
 * Initialize the RX descriptors and allocate mbufs for them. Note that
 * we arrange the descriptors in a closed ring, so that the last descriptor
 * points back to the first.
 */
static int
xl_list_rx_init(sc)
        struct xl_softc         *sc;
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     i;

        cd = &sc->xl_cdata;
        ld = sc->xl_ldata;

        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                cd->xl_rx_chain[i].xl_ptr =
                        (struct xl_list_onefrag *)&ld->xl_rx_list[i];
                if (xl_newbuf(sc, &cd->xl_rx_chain[i]) == ENOBUFS)
                        return(ENOBUFS);
                if (i == (XL_RX_LIST_CNT - 1)) {
                        cd->xl_rx_chain[i].xl_next = &cd->xl_rx_chain[0];
                        ld->xl_rx_list[i].xl_next =
                            vtophys(&ld->xl_rx_list[0]);
                } else {
                        cd->xl_rx_chain[i].xl_next = &cd->xl_rx_chain[i + 1];
                        ld->xl_rx_list[i].xl_next =
                            vtophys(&ld->xl_rx_list[i + 1]);
                }
        }

        cd->xl_rx_head = &cd->xl_rx_chain[0];

        return(0);
}

/*
 * Initialize an RX descriptor and attach an MBUF cluster.
 */
static int
xl_newbuf(sc, c)
        struct xl_softc         *sc;
        struct xl_chain_onefrag *c;
{
        struct mbuf             *m_new = NULL;

        MGETHDR(m_new, M_DONTWAIT, MT_DATA);
        if (m_new == NULL)
                return(ENOBUFS);

        MCLGET(m_new, M_DONTWAIT);
        if (!(m_new->m_flags & M_EXT)) {
                m_freem(m_new);
                return(ENOBUFS);
        }

        m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;

        /* Force longword alignment for packet payload. */
        m_adj(m_new, ETHER_ALIGN);

        c->xl_mbuf = m_new;
        c->xl_ptr->xl_frag.xl_addr = vtophys(mtod(m_new, caddr_t));
        c->xl_ptr->xl_frag.xl_len = MCLBYTES | XL_LAST_FRAG;
        c->xl_ptr->xl_status = 0;

        return(0);
}

static int
xl_rx_resync(sc)
        struct xl_softc         *sc;
{
        struct xl_chain_onefrag *pos;
        int                     i;

        pos = sc->xl_cdata.xl_rx_head;

        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                if (pos->xl_ptr->xl_status)
                        break;
                pos = pos->xl_next;
        }

        if (i == XL_RX_LIST_CNT)
                return(0);

        sc->xl_cdata.xl_rx_head = pos;

        return(EAGAIN);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void
xl_rxeof(sc)
        struct xl_softc         *sc;
{
        struct ether_header     *eh;
        struct mbuf             *m;
        struct ifnet            *ifp;
        struct xl_chain_onefrag *cur_rx;
        int                     total_len = 0;
        u_int32_t               rxstat;

        ifp = &sc->arpcom.ac_if;

again:

        while((rxstat = sc->xl_cdata.xl_rx_head->xl_ptr->xl_status)) {
                cur_rx = sc->xl_cdata.xl_rx_head;
                sc->xl_cdata.xl_rx_head = cur_rx->xl_next;

                /*
                 * If an error occurs, update stats, clear the
                 * status word and leave the mbuf cluster in place:
                 * it should simply get re-used next time this descriptor
                 * comes up in the ring.
                 */
                if (rxstat & XL_RXSTAT_UP_ERROR) {
                        ifp->if_ierrors++;
                        cur_rx->xl_ptr->xl_status = 0;
                        continue;
                }

                /*
                 * If there error bit was not set, the upload complete
                 * bit should be set which means we have a valid packet.
                 * If not, something truly strange has happened.
                 */
                if (!(rxstat & XL_RXSTAT_UP_CMPLT)) {
                        printf("xl%d: bad receive status -- "
                            "packet dropped", sc->xl_unit);
                        ifp->if_ierrors++;
                        cur_rx->xl_ptr->xl_status = 0;
                        continue;
                }

                /* No errors; receive the packet. */    
                m = cur_rx->xl_mbuf;
                total_len = cur_rx->xl_ptr->xl_status & XL_RXSTAT_LENMASK;

                /*
                 * Try to conjure up a new mbuf cluster. If that
                 * fails, it means we have an out of memory condition and
                 * should leave the buffer in place and continue. This will
                 * result in a lost packet, but there's little else we
                 * can do in this situation.
                 */
                if (xl_newbuf(sc, cur_rx) == ENOBUFS) {
                        ifp->if_ierrors++;
                        cur_rx->xl_ptr->xl_status = 0;
                        continue;
                }

                ifp->if_ipackets++;
                eh = mtod(m, struct ether_header *);
                m->m_pkthdr.rcvif = ifp;
                m->m_pkthdr.len = m->m_len = total_len;

                /* Remove header from mbuf and pass it on. */
                m_adj(m, sizeof(struct ether_header));

                if (sc->xl_type == XL_TYPE_905B) {
                        /* Do IP checksum checking. */
                        if (rxstat & XL_RXSTAT_IPCKOK)
                                m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
                        if (!(rxstat & XL_RXSTAT_IPCKERR))
                                m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
                        if ((rxstat & XL_RXSTAT_TCPCOK &&
                             !(rxstat & XL_RXSTAT_TCPCKERR)) ||
                            (rxstat & XL_RXSTAT_UDPCKOK &&
                             !(rxstat & XL_RXSTAT_UDPCKERR))) {
                                m->m_pkthdr.csum_flags |=
                                        CSUM_DATA_VALID|CSUM_PSEUDO_HDR;
                                m->m_pkthdr.csum_data = 0xffff;
                        }
                }
                ether_input(ifp, eh, m);
        }

        /*
         * Handle the 'end of channel' condition. When the upload
         * engine hits the end of the RX ring, it will stall. This
         * is our cue to flush the RX ring, reload the uplist pointer
         * register and unstall the engine.
         * XXX This is actually a little goofy. With the ThunderLAN
         * chip, you get an interrupt when the receiver hits the end
         * of the receive ring, which tells you exactly when you
         * you need to reload the ring pointer. Here we have to
         * fake it. I'm mad at myself for not being clever enough
         * to avoid the use of a goto here.
         */
        if (CSR_READ_4(sc, XL_UPLIST_PTR) == 0 ||
                CSR_READ_4(sc, XL_UPLIST_STATUS) & XL_PKTSTAT_UP_STALLED) {
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
                xl_wait(sc);
                CSR_WRITE_4(sc, XL_UPLIST_PTR,
                        vtophys(&sc->xl_ldata->xl_rx_list[0]));
                sc->xl_cdata.xl_rx_head = &sc->xl_cdata.xl_rx_chain[0];
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
                goto again;
        }

        return;
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */
static void
xl_txeof(sc)
        struct xl_softc         *sc;
{
        struct xl_chain         *cur_tx;
        struct ifnet            *ifp;

        ifp = &sc->arpcom.ac_if;

        /* Clear the timeout timer. */
        ifp->if_timer = 0;

        /*
         * Go through our tx list and free mbufs for those
         * frames that have been uploaded. Note: the 3c905B
         * sets a special bit in the status word to let us
         * know that a frame has been downloaded, but the
         * original 3c900/3c905 adapters don't do that.
         * Consequently, we have to use a different test if
         * xl_type != XL_TYPE_905B.
         */
        while(sc->xl_cdata.xl_tx_head != NULL) {
                cur_tx = sc->xl_cdata.xl_tx_head;

                if (CSR_READ_4(sc, XL_DOWNLIST_PTR))
                        break;

                sc->xl_cdata.xl_tx_head = cur_tx->xl_next;
                m_freem(cur_tx->xl_mbuf);
                cur_tx->xl_mbuf = NULL;
                ifp->if_opackets++;

                cur_tx->xl_next = sc->xl_cdata.xl_tx_free;
                sc->xl_cdata.xl_tx_free = cur_tx;
        }

        if (sc->xl_cdata.xl_tx_head == NULL) {
                ifp->if_flags &= ~IFF_OACTIVE;
                sc->xl_cdata.xl_tx_tail = NULL;
        } else {
                if (CSR_READ_4(sc, XL_DMACTL) & XL_DMACTL_DOWN_STALLED ||
                        !CSR_READ_4(sc, XL_DOWNLIST_PTR)) {
                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                vtophys(sc->xl_cdata.xl_tx_head->xl_ptr));
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                }
        }

        return;
}

static void xl_txeof_90xB(sc)
        struct xl_softc         *sc;
{
        struct xl_chain         *cur_tx = NULL;
        struct ifnet            *ifp;
        int                     idx;

        ifp = &sc->arpcom.ac_if;

        idx = sc->xl_cdata.xl_tx_cons;
        while(idx != sc->xl_cdata.xl_tx_prod) {

                cur_tx = &sc->xl_cdata.xl_tx_chain[idx];

                if (!(cur_tx->xl_ptr->xl_status & XL_TXSTAT_DL_COMPLETE))
                        break;

                if (cur_tx->xl_mbuf != NULL) {
                        m_freem(cur_tx->xl_mbuf);
                        cur_tx->xl_mbuf = NULL;
                }

                ifp->if_opackets++;

                sc->xl_cdata.xl_tx_cnt--;
                XL_INC(idx, XL_TX_LIST_CNT);
                ifp->if_timer = 0;
        }

        sc->xl_cdata.xl_tx_cons = idx;

        if (cur_tx != NULL)
                ifp->if_flags &= ~IFF_OACTIVE;

        return;
}

/*
 * TX 'end of channel' interrupt handler. Actually, we should
 * only get a 'TX complete' interrupt if there's a transmit error,
 * so this is really TX error handler.
 */
static void
xl_txeoc(sc)
        struct xl_softc         *sc;
{
        u_int8_t                txstat;

        while((txstat = CSR_READ_1(sc, XL_TX_STATUS))) {
                if (txstat & XL_TXSTATUS_UNDERRUN ||
                        txstat & XL_TXSTATUS_JABBER ||
                        txstat & XL_TXSTATUS_RECLAIM) {
                        printf("xl%d: transmission error: %x\n",
                                                sc->xl_unit, txstat);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
                        xl_wait(sc);
                        if (sc->xl_type == XL_TYPE_905B) {
                                if (sc->xl_cdata.xl_tx_cnt) {
                                        int                     i;
                                        struct xl_chain         *c;
                                        i = sc->xl_cdata.xl_tx_cons;
                                        c = &sc->xl_cdata.xl_tx_chain[i];
                                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                            c->xl_phys);
                                        CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                                }
                        } else {
                                if (sc->xl_cdata.xl_tx_head != NULL)
                                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                vtophys(sc->xl_cdata.xl_tx_head->xl_ptr));
                        }
                        /*
                         * Remember to set this for the
                         * first generation 3c90X chips.
                         */
                        CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);
                        if (txstat & XL_TXSTATUS_UNDERRUN &&
                            sc->xl_tx_thresh < XL_PACKET_SIZE) {
                                sc->xl_tx_thresh += XL_MIN_FRAMELEN;
                                printf("xl%d: tx underrun, increasing tx start"
                                    " threshold to %d bytes\n", sc->xl_unit,
                                    sc->xl_tx_thresh);
                        }
                        CSR_WRITE_2(sc, XL_COMMAND,
                            XL_CMD_TX_SET_START|sc->xl_tx_thresh);
                        if (sc->xl_type == XL_TYPE_905B) {
                                CSR_WRITE_2(sc, XL_COMMAND,
                                XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
                        }
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                } else {
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                }
                /*
                 * Write an arbitrary byte to the TX_STATUS register
                 * to clear this interrupt/error and advance to the next.
                 */
                CSR_WRITE_1(sc, XL_TX_STATUS, 0x01);
        }

        return;
}

static void
xl_intr(arg)
        void                    *arg;
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        u_int16_t               status;

        sc = arg;
        ifp = &sc->arpcom.ac_if;

        while((status = CSR_READ_2(sc, XL_STATUS)) & XL_INTRS && status != 0xFFFF) {

                CSR_WRITE_2(sc, XL_COMMAND,
                    XL_CMD_INTR_ACK|(status & XL_INTRS));

                if (status & XL_STAT_UP_COMPLETE) {
                        int                     curpkts;

                        curpkts = ifp->if_ipackets;
                        xl_rxeof(sc);
                        if (curpkts == ifp->if_ipackets) {
                                while (xl_rx_resync(sc))
                                        xl_rxeof(sc);
                        }
                }

                if (status & XL_STAT_DOWN_COMPLETE) {
                        if (sc->xl_type == XL_TYPE_905B)
                                xl_txeof_90xB(sc);
                        else
                                xl_txeof(sc);
                }

                if (status & XL_STAT_TX_COMPLETE) {
                        ifp->if_oerrors++;
                        xl_txeoc(sc);
                }

                if (status & XL_STAT_ADFAIL) {
                        xl_reset(sc);
                        xl_init(sc);
                }

                if (status & XL_STAT_STATSOFLOW) {
                        sc->xl_stats_no_timeout = 1;
                        xl_stats_update(sc);
                        sc->xl_stats_no_timeout = 0;
                }
        }

        if (ifp->if_snd.ifq_head != NULL)
                (*ifp->if_start)(ifp);

        return;
}

static void
xl_stats_update(xsc)
        void                    *xsc;
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        struct xl_stats         xl_stats;
        u_int8_t                *p;
        int                     i;
        struct mii_data         *mii = NULL;

        bzero((char *)&xl_stats, sizeof(struct xl_stats));

        sc = xsc;
        ifp = &sc->arpcom.ac_if;
        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);

        p = (u_int8_t *)&xl_stats;

        /* Read all the stats registers. */
        XL_SEL_WIN(6);

        for (i = 0; i < 16; i++)
                *p++ = CSR_READ_1(sc, XL_W6_CARRIER_LOST + i);

        ifp->if_ierrors += xl_stats.xl_rx_overrun;

        ifp->if_collisions += xl_stats.xl_tx_multi_collision +
                                xl_stats.xl_tx_single_collision +
                                xl_stats.xl_tx_late_collision;

        /*
         * Boomerang and cyclone chips have an extra stats counter
         * in window 4 (BadSSD). We have to read this too in order
         * to clear out all the stats registers and avoid a statsoflow
         * interrupt.
         */
        XL_SEL_WIN(4);
        CSR_READ_1(sc, XL_W4_BADSSD);

        if ((mii != NULL) && (!sc->xl_stats_no_timeout))
                mii_tick(mii);

        XL_SEL_WIN(7);

        if (!sc->xl_stats_no_timeout)
                sc->xl_stat_ch = timeout(xl_stats_update, sc, hz);

        return;
}

/*
 * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
 * pointers to the fragment pointers.
 */
static int
xl_encap(sc, c, m_head)
        struct xl_softc         *sc;
        struct xl_chain         *c;
        struct mbuf             *m_head;
{
        int                     frag;
        struct xl_frag          *f = NULL;
        int                     total_len;
        struct mbuf             *m;

        /*
         * Start packing the mbufs in this chain into
         * the fragment pointers. Stop when we run out
         * of fragments or hit the end of the mbuf chain.
         */
        m = m_head;
        total_len = 0;

        for (m = m_head, frag = 0; m != NULL; m = m->m_next) {
                if (m->m_len != 0) {
                        if (frag == XL_MAXFRAGS)
                                break;
                        total_len += m->m_len;
                        f = &c->xl_ptr->xl_frag[frag];
                        f->xl_addr = vtophys(mtod(m, vm_offset_t));
                        f->xl_len = m->m_len;
                        frag++;
                }
        }

        /*
         * Handle special case: we used up all 63 fragments,
         * but we have more mbufs left in the chain. Copy the
         * data into an mbuf cluster. Note that we don't
         * bother clearing the values in the other fragment
         * pointers/counters; it wouldn't gain us anything,
         * and would waste cycles.
         */
        if (m != NULL) {
                struct mbuf             *m_new = NULL;

                MGETHDR(m_new, M_DONTWAIT, MT_DATA);
                if (m_new == NULL) {
                        printf("xl%d: no memory for tx list", sc->xl_unit);
                        return(1);
                }
                if (m_head->m_pkthdr.len > MHLEN) {
                        MCLGET(m_new, M_DONTWAIT);
                        if (!(m_new->m_flags & M_EXT)) {
                                m_freem(m_new);
                                printf("xl%d: no memory for tx list",
                                                sc->xl_unit);
                                return(1);
                        }
                }
                m_copydata(m_head, 0, m_head->m_pkthdr.len,     
                                        mtod(m_new, caddr_t));
                m_new->m_pkthdr.len = m_new->m_len = m_head->m_pkthdr.len;
                m_freem(m_head);
                m_head = m_new;
                f = &c->xl_ptr->xl_frag[0];
                f->xl_addr = vtophys(mtod(m_new, caddr_t));
                f->xl_len = total_len = m_new->m_len;
        }

        if (sc->xl_type == XL_TYPE_905B) {
                c->xl_ptr->xl_status = XL_TXSTAT_RND_DEFEAT;

                if (m_head->m_pkthdr.csum_flags) {
                        if (m_head->m_pkthdr.csum_flags & CSUM_IP)
                                c->xl_ptr->xl_status |= XL_TXSTAT_IPCKSUM;
                        if (m_head->m_pkthdr.csum_flags & CSUM_TCP)
                                c->xl_ptr->xl_status |= XL_TXSTAT_TCPCKSUM;
                        if (m_head->m_pkthdr.csum_flags & CSUM_UDP)
                                c->xl_ptr->xl_status |= XL_TXSTAT_UDPCKSUM;
                }
        } else
                c->xl_ptr->xl_status = total_len;

        c->xl_mbuf = m_head;
        f->xl_len |= XL_LAST_FRAG;
        c->xl_ptr->xl_next = 0;

        return(0);
}

/*
 * Main transmit routine. To avoid having to do mbuf copies, we put pointers
 * to the mbuf data regions directly in the transmit lists. We also save a
 * copy of the pointers since the transmit list fragment pointers are
 * physical addresses.
 */
static void
xl_start(ifp)
        struct ifnet            *ifp;
{
        struct xl_softc         *sc;
        struct mbuf             *m_head = NULL;
        struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;

        sc = ifp->if_softc;

        /*
         * Check for an available queue slot. If there are none,
         * punt.
         */
        if (sc->xl_cdata.xl_tx_free == NULL) {
                xl_txeoc(sc);
                xl_txeof(sc);
                if (sc->xl_cdata.xl_tx_free == NULL) {
                        ifp->if_flags |= IFF_OACTIVE;
                        return;
                }
        }

        start_tx = sc->xl_cdata.xl_tx_free;

        while(sc->xl_cdata.xl_tx_free != NULL) {
                IF_DEQUEUE(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                /* Pick a descriptor off the free list. */
                cur_tx = sc->xl_cdata.xl_tx_free;
                sc->xl_cdata.xl_tx_free = cur_tx->xl_next;

                cur_tx->xl_next = NULL;

                /* Pack the data into the descriptor. */
                xl_encap(sc, cur_tx, m_head);

                /* Chain it together. */
                if (prev != NULL) {
                        prev->xl_next = cur_tx;
                        prev->xl_ptr->xl_next = vtophys(cur_tx->xl_ptr);
                }
                prev = cur_tx;

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                if (ifp->if_bpf)
                        bpf_mtap(ifp, cur_tx->xl_mbuf);
        }

        /*
         * If there are no packets queued, bail.
         */
        if (cur_tx == NULL)
                return;

        /*
         * Place the request for the upload interrupt
         * in the last descriptor in the chain. This way, if
         * we're chaining several packets at once, we'll only
         * get an interupt once for the whole chain rather than
         * once for each packet.
         */
        cur_tx->xl_ptr->xl_status |= XL_TXSTAT_DL_INTR;

        /*
         * Queue the packets. If the TX channel is clear, update
         * the downlist pointer register.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
        xl_wait(sc);

        if (sc->xl_cdata.xl_tx_head != NULL) {
                sc->xl_cdata.xl_tx_tail->xl_next = start_tx;
                sc->xl_cdata.xl_tx_tail->xl_ptr->xl_next =
                                        vtophys(start_tx->xl_ptr);
                sc->xl_cdata.xl_tx_tail->xl_ptr->xl_status &=
                                        ~XL_TXSTAT_DL_INTR;
                sc->xl_cdata.xl_tx_tail = cur_tx;
        } else {
                sc->xl_cdata.xl_tx_head = start_tx;
                sc->xl_cdata.xl_tx_tail = cur_tx;
        }
        if (!CSR_READ_4(sc, XL_DOWNLIST_PTR))
                CSR_WRITE_4(sc, XL_DOWNLIST_PTR, vtophys(start_tx->xl_ptr));

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);

        XL_SEL_WIN(7);

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        ifp->if_timer = 5;

        /*
         * XXX Under certain conditions, usually on slower machines
         * where interrupts may be dropped, it's possible for the
         * adapter to chew up all the buffers in the receive ring
         * and stall, without us being able to do anything about it.
         * To guard against this, we need to make a pass over the
         * RX queue to make sure there aren't any packets pending.
         * Doing it here means we can flush the receive ring at the
         * same time the chip is DMAing the transmit descriptors we
         * just gave it.
         *
         * 3Com goes to some lengths to emphasize the Parallel Tasking (tm)
         * nature of their chips in all their marketing literature;
         * we may as well take advantage of it. :)
         */
        xl_rxeof(sc);

        return;
}

static void xl_start_90xB(ifp)
        struct ifnet            *ifp;
{
        struct xl_softc         *sc;
        struct mbuf             *m_head = NULL;
        struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;
        int                     idx;

        sc = ifp->if_softc;

        if (ifp->if_flags & IFF_OACTIVE)
                return;

        idx = sc->xl_cdata.xl_tx_prod;
        start_tx = &sc->xl_cdata.xl_tx_chain[idx];

        while (sc->xl_cdata.xl_tx_chain[idx].xl_mbuf == NULL) {

                if ((XL_TX_LIST_CNT - sc->xl_cdata.xl_tx_cnt) < 3) {
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }

                IF_DEQUEUE(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                cur_tx = &sc->xl_cdata.xl_tx_chain[idx];

                /* Pack the data into the descriptor. */
                xl_encap(sc, cur_tx, m_head);

                /* Chain it together. */
                if (prev != NULL)
                        prev->xl_ptr->xl_next = cur_tx->xl_phys;
                prev = cur_tx;

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                if (ifp->if_bpf)
                        bpf_mtap(ifp, cur_tx->xl_mbuf);

                XL_INC(idx, XL_TX_LIST_CNT);
                sc->xl_cdata.xl_tx_cnt++;
        }

        /*
         * If there are no packets queued, bail.
         */
        if (cur_tx == NULL)
                return;

        /*
         * Place the request for the upload interrupt
         * in the last descriptor in the chain. This way, if
         * we're chaining several packets at once, we'll only
         * get an interupt once for the whole chain rather than
         * once for each packet.
         */
        cur_tx->xl_ptr->xl_status |= XL_TXSTAT_DL_INTR;

        /* Start transmission */
        sc->xl_cdata.xl_tx_prod = idx;
        start_tx->xl_prev->xl_ptr->xl_next = start_tx->xl_phys;

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        ifp->if_timer = 5;

        return;
}

static void
xl_init(xsc)
        void                    *xsc;
{
        struct xl_softc         *sc = xsc;
        struct ifnet            *ifp = &sc->arpcom.ac_if;
        int                     s, i;
        u_int16_t               rxfilt = 0;
        struct mii_data         *mii = NULL;

        s = splimp();

        /*
         * Cancel pending I/O and free all RX/TX buffers.
         */
        xl_stop(sc);

        if (sc->xl_miibus == NULL) {
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
                xl_wait(sc);
        }
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
        DELAY(10000);

        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);

        /* Init our MAC address */
        XL_SEL_WIN(2);
        for (i = 0; i < ETHER_ADDR_LEN; i++) {
                CSR_WRITE_1(sc, XL_W2_STATION_ADDR_LO + i,
                                sc->arpcom.ac_enaddr[i]);
        }

        /* Clear the station mask. */
        for (i = 0; i < 3; i++)
                CSR_WRITE_2(sc, XL_W2_STATION_MASK_LO + (i * 2), 0);
#ifdef notdef
        /* Reset TX and RX. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
#endif
        /* Init circular RX list. */
        if (xl_list_rx_init(sc) == ENOBUFS) {
                printf("xl%d: initialization failed: no "
                        "memory for rx buffers\n", sc->xl_unit);
                xl_stop(sc);
                splx(s);
                return;
        }

        /* Init TX descriptors. */
        if (sc->xl_type == XL_TYPE_905B)
                xl_list_tx_init_90xB(sc);
        else
                xl_list_tx_init(sc);

        /*
         * Set the TX freethresh value.
         * Note that this has no effect on 3c905B "cyclone"
         * cards but is required for 3c900/3c905 "boomerang"
         * cards in order to enable the download engine.
         */
        CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);

        /* Set the TX start threshold for best performance. */
        sc->xl_tx_thresh = XL_MIN_FRAMELEN;
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_SET_START|sc->xl_tx_thresh);

        /*
         * If this is a 3c905B, also set the tx reclaim threshold.
         * This helps cut down on the number of tx reclaim errors
         * that could happen on a busy network. The chip multiplies
         * the register value by 16 to obtain the actual threshold
         * in bytes, so we divide by 16 when setting the value here.
         * The existing threshold value can be examined by reading
         * the register at offset 9 in window 5.
         */
        if (sc->xl_type == XL_TYPE_905B) {
                CSR_WRITE_2(sc, XL_COMMAND,
                    XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
        }

        /* Set RX filter bits. */
        XL_SEL_WIN(5);
        rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);

        /* Set the individual bit to receive frames for this host only. */
        rxfilt |= XL_RXFILTER_INDIVIDUAL;

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC) {
                rxfilt |= XL_RXFILTER_ALLFRAMES;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
        } else {
                rxfilt &= ~XL_RXFILTER_ALLFRAMES;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
        }

        /*
         * Set capture broadcast bit to capture broadcast frames.
         */
        if (ifp->if_flags & IFF_BROADCAST) {
                rxfilt |= XL_RXFILTER_BROADCAST;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
        } else {
                rxfilt &= ~XL_RXFILTER_BROADCAST;
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
        }

        /*
         * Program the multicast filter, if necessary.
         */
        if (sc->xl_type == XL_TYPE_905B)
                xl_setmulti_hash(sc);
        else
                xl_setmulti(sc);

        /*
         * Load the address of the RX list. We have to
         * stall the upload engine before we can manipulate
         * the uplist pointer register, then unstall it when
         * we're finished. We also have to wait for the
         * stall command to complete before proceeding.
         * Note that we have to do this after any RX resets
         * have completed since the uplist register is cleared
         * by a reset.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
        xl_wait(sc);
        CSR_WRITE_4(sc, XL_UPLIST_PTR, vtophys(&sc->xl_ldata->xl_rx_list[0]));
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
        xl_wait(sc);


        if (sc->xl_type == XL_TYPE_905B) {
                /* Set polling interval */
                CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                /* Load the address of the TX list */
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
                xl_wait(sc);
                CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                    vtophys(&sc->xl_ldata->xl_tx_list[0]));
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                xl_wait(sc);
        }

        /*
         * If the coax transceiver is on, make sure to enable
         * the DC-DC converter.
         */
        XL_SEL_WIN(3);
        if (sc->xl_xcvr == XL_XCVR_COAX)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
        else
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);

        /* increase packet size to allow reception of 802.1q or ISL packets */
         if (sc->xl_type == XL_TYPE_905B) 
                CSR_WRITE_2(sc, XL_W3_MAXPKTSIZE, XL_PACKET_SIZE);
        /* Clear out the stats counters. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
        sc->xl_stats_no_timeout = 1;
        xl_stats_update(sc);
        sc->xl_stats_no_timeout = 0;
        XL_SEL_WIN(4);
        CSR_WRITE_2(sc, XL_W4_NET_DIAG, XL_NETDIAG_UPPER_BYTES_ENABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_ENABLE);

        /*
         * Enable interrupts.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|0xFF);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|XL_INTRS);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|XL_INTRS);
        if (sc->xl_flags & XL_FLAG_FUNCREG) bus_space_write_4 (sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);

        /* Set the RX early threshold */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_THRESH|(XL_PACKET_SIZE >>2));
        CSR_WRITE_2(sc, XL_DMACTL, XL_DMACTL_UP_RX_EARLY);

        /* Enable receiver and transmitter. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_ENABLE);
        xl_wait(sc);

        if (mii != NULL)
                mii_mediachg(mii);

        /* Select window 7 for normal operations. */
        XL_SEL_WIN(7);

        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;

        (void)splx(s);

        sc->xl_stat_ch = timeout(xl_stats_update, sc, hz);

        return;
}

/*
 * Set media options.
 */
static int
xl_ifmedia_upd(ifp)
        struct ifnet            *ifp;
{
        struct xl_softc         *sc;
        struct ifmedia          *ifm = NULL;
        struct mii_data         *mii = NULL;

        sc = ifp->if_softc;
        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);
        if (mii == NULL)
                ifm = &sc->ifmedia;
        else
                ifm = &mii->mii_media;

        switch(IFM_SUBTYPE(ifm->ifm_media)) {
        case IFM_100_FX:
        case IFM_10_FL:
        case IFM_10_2:
        case IFM_10_5:
                xl_setmode(sc, ifm->ifm_media);
                return(0);
                break;
        default:
                break;
        }

        if (sc->xl_media & XL_MEDIAOPT_MII || sc->xl_media & XL_MEDIAOPT_BTX
                || sc->xl_media & XL_MEDIAOPT_BT4) {
                xl_init(sc);
        } else {
                xl_setmode(sc, ifm->ifm_media);
        }

        return(0);
}

/*
 * Report current media status.
 */
static void
xl_ifmedia_sts(ifp, ifmr)
        struct ifnet            *ifp;
        struct ifmediareq       *ifmr;
{
        struct xl_softc         *sc;
        u_int32_t               icfg;
        struct mii_data         *mii = NULL;

        sc = ifp->if_softc;
        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);

        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG) & XL_ICFG_CONNECTOR_MASK;
        icfg >>= XL_ICFG_CONNECTOR_BITS;

        ifmr->ifm_active = IFM_ETHER;

        switch(icfg) {
        case XL_XCVR_10BT:
                ifmr->ifm_active = IFM_ETHER|IFM_10_T;
                if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                        ifmr->ifm_active |= IFM_FDX;
                else
                        ifmr->ifm_active |= IFM_HDX;
                break;
        case XL_XCVR_AUI:
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        ifmr->ifm_active = IFM_ETHER|IFM_10_FL;
                        if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                                ifmr->ifm_active |= IFM_FDX;
                        else
                                ifmr->ifm_active |= IFM_HDX;
                } else
                        ifmr->ifm_active = IFM_ETHER|IFM_10_5;
                break;
        case XL_XCVR_COAX:
                ifmr->ifm_active = IFM_ETHER|IFM_10_2;
                break;
        /*
         * XXX MII and BTX/AUTO should be separate cases.
         */

        case XL_XCVR_100BTX:
        case XL_XCVR_AUTO:
        case XL_XCVR_MII:
                if (mii != NULL) {
                        mii_pollstat(mii);
                        ifmr->ifm_active = mii->mii_media_active;
                        ifmr->ifm_status = mii->mii_media_status;
                }
                break;
        case XL_XCVR_100BFX:
                ifmr->ifm_active = IFM_ETHER|IFM_100_FX;
                break;
        default:
                printf("xl%d: unknown XCVR type: %d\n", sc->xl_unit, icfg);
                break;
        }

        return;
}

static int
xl_ioctl(ifp, command, data)
        struct ifnet            *ifp;
        u_long                  command;
        caddr_t                 data;
{
        struct xl_softc         *sc = ifp->if_softc;
        struct ifreq            *ifr = (struct ifreq *) data;
        int                     s, error = 0;
        struct mii_data         *mii = NULL;
        u_int8_t                rxfilt;

        s = splimp();

        switch(command) {
        case SIOCSIFADDR:
        case SIOCGIFADDR:
        case SIOCSIFMTU:
                error = ether_ioctl(ifp, command, data);
                break;
        case SIOCSIFFLAGS:
                XL_SEL_WIN(5);
                rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
                if (ifp->if_flags & IFF_UP) {
                        if (ifp->if_flags & IFF_RUNNING &&
                            ifp->if_flags & IFF_PROMISC &&
                            !(sc->xl_if_flags & IFF_PROMISC)) {
                                rxfilt |= XL_RXFILTER_ALLFRAMES;
                                CSR_WRITE_2(sc, XL_COMMAND,
                                    XL_CMD_RX_SET_FILT|rxfilt);
                                XL_SEL_WIN(7);
                        } else if (ifp->if_flags & IFF_RUNNING &&
                            !(ifp->if_flags & IFF_PROMISC) &&
                            sc->xl_if_flags & IFF_PROMISC) {
                                rxfilt &= ~XL_RXFILTER_ALLFRAMES;
                                CSR_WRITE_2(sc, XL_COMMAND,
                                    XL_CMD_RX_SET_FILT|rxfilt);
                                XL_SEL_WIN(7);
                        } else
                                xl_init(sc);
                } else {
                        if (ifp->if_flags & IFF_RUNNING)
                                xl_stop(sc);
                }
                sc->xl_if_flags = ifp->if_flags;
                error = 0;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                if (sc->xl_type == XL_TYPE_905B)
                        xl_setmulti_hash(sc);
                else
                        xl_setmulti(sc);
                error = 0;
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                if (sc->xl_miibus != NULL)
                        mii = device_get_softc(sc->xl_miibus);
                if (mii == NULL)
                        error = ifmedia_ioctl(ifp, ifr,
                            &sc->ifmedia, command);
                else
                        error = ifmedia_ioctl(ifp, ifr,
                            &mii->mii_media, command);
                break;
        default:
                error = EINVAL;
                break;
        }

        (void)splx(s);

        return(error);
}

static void
xl_watchdog(ifp)
        struct ifnet            *ifp;
{
        struct xl_softc         *sc;
        u_int16_t               status = 0;

        sc = ifp->if_softc;

        ifp->if_oerrors++;
        XL_SEL_WIN(4);
        status = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
        printf("xl%d: watchdog timeout\n", sc->xl_unit);

        if (status & XL_MEDIASTAT_CARRIER)
                printf("xl%d: no carrier - transceiver cable problem?\n",
                                                                sc->xl_unit);
        xl_txeoc(sc);
        xl_txeof(sc);
        xl_rxeof(sc);
        xl_reset(sc);
        xl_init(sc);

        if (ifp->if_snd.ifq_head != NULL)
                (*ifp->if_start)(ifp);

        return;
}

/*
 * Stop the adapter and free any mbufs allocated to the
 * RX and TX lists.
 */
static void
xl_stop(sc)
        struct xl_softc         *sc;
{
        register int            i;
        struct ifnet            *ifp;

        ifp = &sc->arpcom.ac_if;
        ifp->if_timer = 0;

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISCARD);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
        DELAY(800);

#ifdef foo
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
#endif

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|XL_STAT_INTLATCH);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|0);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|0);
        if (sc->xl_flags & XL_FLAG_FUNCREG) bus_space_write_4 (sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);

        /* Stop the stats updater. */
        untimeout(xl_stats_update, sc, sc->xl_stat_ch);

        /*
         * Free data in the RX lists.
         */
        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                if (sc->xl_cdata.xl_rx_chain[i].xl_mbuf != NULL) {
                        m_freem(sc->xl_cdata.xl_rx_chain[i].xl_mbuf);
                        sc->xl_cdata.xl_rx_chain[i].xl_mbuf = NULL;
                }
        }
        bzero((char *)&sc->xl_ldata->xl_rx_list,
                sizeof(sc->xl_ldata->xl_rx_list));
        /*
         * Free the TX list buffers.
         */
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                if (sc->xl_cdata.xl_tx_chain[i].xl_mbuf != NULL) {
                        m_freem(sc->xl_cdata.xl_tx_chain[i].xl_mbuf);
                        sc->xl_cdata.xl_tx_chain[i].xl_mbuf = NULL;
                }
        }
        bzero((char *)&sc->xl_ldata->xl_tx_list,
                sizeof(sc->xl_ldata->xl_tx_list));

        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);

        return;
}

/*
 * Stop all chip I/O so that the kernel's probe routines don't
 * get confused by errant DMAs when rebooting.
 */
static void
xl_shutdown(dev)
        device_t                dev;
{
        struct xl_softc         *sc;

        sc = device_get_softc(dev);

        xl_reset(sc);
        xl_stop(sc);

        return;
}

static int
xl_suspend(dev)
        device_t                dev;
{
        struct xl_softc         *sc;
        int                     s;

        sc = device_get_softc(dev);

        s = splimp();
        xl_stop(sc);
        splx(s);

        return(0);
}

static int
xl_resume(dev)
        device_t                dev;
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        int                     s;

        s = splimp();
        sc = device_get_softc(dev);
        ifp = &sc->arpcom.ac_if;

        xl_reset(sc);
        if (ifp->if_flags & IFF_UP)
                xl_init(sc);

        splx(s);
        return(0);
}