/*
 * Copyright (c) 1997, 1998
 *      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_vr.c,v 1.26.2.13 2003/02/06 04:46:20 silby Exp $
 */

/*
 * VIA Rhine fast ethernet PCI NIC driver
 *
 * Supports various network adapters based on the VIA Rhine
 * and Rhine II PCI controllers, including the D-Link DFE530TX.
 * Datasheets are available at http://www.via.com.tw.
 *
 * Written by Bill Paul <wpaul@ctr.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */

/*
 * The VIA Rhine controllers are similar in some respects to the
 * the DEC tulip chips, except less complicated. The controller
 * uses an MII bus and an external physical layer interface. The
 * receiver has a one entry perfect filter and a 64-bit hash table
 * multicast filter. Transmit and receive descriptors are similar
 * to the tulip.
 *
 * The Rhine has a serious flaw in its transmit DMA mechanism:
 * transmit buffers must be longword aligned. Unfortunately,
 * FreeBSD doesn't guarantee that mbufs will be filled in starting
 * at longword boundaries, so we have to do a buffer copy before
 * transmission.
 */

#include "opt_ifpoll.h"

#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 <sys/serialize.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/interrupt.h>

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

#include <net/bpf.h>

#include <vm/vm.h>              /* for vtophys */
#include <vm/pmap.h>            /* for vtophys */

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

#include "pcidevs.h"
#include <bus/pci/pcireg.h>
#include <bus/pci/pcivar.h>

#define VR_USEIOSPACE

#include <dev/netif/vr/if_vrreg.h>

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

#undef VR_USESWSHIFT

/*
 * Various supported device vendors/types and their names.
 */
static struct vr_type vr_devs[] = {
        { PCI_VENDOR_VIATECH, PCI_PRODUCT_VIATECH_VT3043,
                "VIA VT3043 Rhine I 10/100BaseTX" },
        { PCI_VENDOR_VIATECH, PCI_PRODUCT_VIATECH_VT86C100A,
                "VIA VT86C100A Rhine II 10/100BaseTX" },
        { PCI_VENDOR_VIATECH, PCI_PRODUCT_VIATECH_VT6102,
                "VIA VT6102 Rhine II 10/100BaseTX" },
        { PCI_VENDOR_VIATECH, PCI_PRODUCT_VIATECH_VT6105,
                "VIA VT6105 Rhine III 10/100BaseTX" },
        { PCI_VENDOR_VIATECH, PCI_PRODUCT_VIATECH_VT6105M,
                "VIA VT6105M Rhine III 10/100BaseTX" },
        { PCI_VENDOR_DELTA, PCI_PRODUCT_DELTA_RHINEII,
                "Delta Electronics Rhine II 10/100BaseTX" },
        { PCI_VENDOR_ADDTRON, PCI_PRODUCT_ADDTRON_RHINEII,
                "Addtron Technology Rhine II 10/100BaseTX" },
        { 0, 0, NULL }
};

static int      vr_probe(device_t);
static int      vr_attach(device_t);
static int      vr_detach(device_t);

static int      vr_newbuf(struct vr_softc *, struct vr_chain_onefrag *,
                          struct mbuf *);
static int      vr_encap(struct vr_softc *, int, struct mbuf * );

static void     vr_rxeof(struct vr_softc *);
static void     vr_rxeoc(struct vr_softc *);
static void     vr_txeof(struct vr_softc *);
static void     vr_txeoc(struct vr_softc *);
static void     vr_tick(void *);
static void     vr_intr(void *);
static void     vr_start(struct ifnet *, struct ifaltq_subque *);
static int      vr_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
static void     vr_init(void *);
static void     vr_stop(struct vr_softc *);
static void     vr_watchdog(struct ifnet *);
static void     vr_shutdown(device_t);
static int      vr_ifmedia_upd(struct ifnet *);
static void     vr_ifmedia_sts(struct ifnet *, struct ifmediareq *);

#ifdef VR_USESWSHIFT
static void     vr_mii_sync(struct vr_softc *);
static void     vr_mii_send(struct vr_softc *, uint32_t, int);
#endif
static int      vr_mii_readreg(struct vr_softc *, struct vr_mii_frame *);
static int      vr_mii_writereg(struct vr_softc *, struct vr_mii_frame *);
static int      vr_miibus_readreg(device_t, int, int);
static int      vr_miibus_writereg(device_t, int, int, int);
static void     vr_miibus_statchg(device_t);

static void     vr_setcfg(struct vr_softc *, int);
static void     vr_setmulti(struct vr_softc *);
static void     vr_reset(struct vr_softc *);
static int      vr_list_rx_init(struct vr_softc *);
static int      vr_list_tx_init(struct vr_softc *);
#ifdef IFPOLL_ENABLE
static void     vr_npoll(struct ifnet *, struct ifpoll_info *);
static void     vr_npoll_compat(struct ifnet *, void *, int);
#endif

#ifdef VR_USEIOSPACE
#define VR_RES                  SYS_RES_IOPORT
#define VR_RID                  VR_PCI_LOIO
#else
#define VR_RES                  SYS_RES_MEMORY
#define VR_RID                  VR_PCI_LOMEM
#endif

static device_method_t vr_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         vr_probe),
        DEVMETHOD(device_attach,        vr_attach),
        DEVMETHOD(device_detach,        vr_detach),
        DEVMETHOD(device_shutdown,      vr_shutdown),

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

        /* MII interface */
        DEVMETHOD(miibus_readreg,       vr_miibus_readreg),
        DEVMETHOD(miibus_writereg,      vr_miibus_writereg),
        DEVMETHOD(miibus_statchg,       vr_miibus_statchg),

        DEVMETHOD_END
};

static driver_t vr_driver = {
        "vr",
        vr_methods,
        sizeof(struct vr_softc)
};

static devclass_t vr_devclass;

DECLARE_DUMMY_MODULE(if_vr);
DRIVER_MODULE(if_vr, pci, vr_driver, vr_devclass, NULL, NULL);
DRIVER_MODULE(miibus, vr, miibus_driver, miibus_devclass, NULL, NULL);

#define VR_SETBIT(sc, reg, x)                           \
        CSR_WRITE_1(sc, reg,                            \
                CSR_READ_1(sc, reg) | (x))

#define VR_CLRBIT(sc, reg, x)                           \
        CSR_WRITE_1(sc, reg,                            \
                CSR_READ_1(sc, reg) & ~(x))

#define VR_SETBIT16(sc, reg, x)                         \
        CSR_WRITE_2(sc, reg,                            \
                CSR_READ_2(sc, reg) | (x))

#define VR_CLRBIT16(sc, reg, x)                         \
        CSR_WRITE_2(sc, reg,                            \
                CSR_READ_2(sc, reg) & ~(x))

#define VR_SETBIT32(sc, reg, x)                         \
        CSR_WRITE_4(sc, reg,                            \
                CSR_READ_4(sc, reg) | (x))

#define VR_CLRBIT32(sc, reg, x)                         \
        CSR_WRITE_4(sc, reg,                            \
                CSR_READ_4(sc, reg) & ~(x))

#define SIO_SET(x)                                      \
        CSR_WRITE_1(sc, VR_MIICMD,                      \
                CSR_READ_1(sc, VR_MIICMD) | (x))

#define SIO_CLR(x)                                      \
        CSR_WRITE_1(sc, VR_MIICMD,                      \
                CSR_READ_1(sc, VR_MIICMD) & ~(x))

#ifdef VR_USESWSHIFT
/*
 * Sync the PHYs by setting data bit and strobing the clock 32 times.
 */
static void
vr_mii_sync(struct vr_softc *sc)
{
        int i;

        SIO_SET(VR_MIICMD_DIR|VR_MIICMD_DATAIN);

        for (i = 0; i < 32; i++) {
                SIO_SET(VR_MIICMD_CLK);
                DELAY(1);
                SIO_CLR(VR_MIICMD_CLK);
                DELAY(1);
        }
}

/*
 * Clock a series of bits through the MII.
 */
static void
vr_mii_send(struct vr_softc *sc, uint32_t bits, int cnt)
{
        int i;

        SIO_CLR(VR_MIICMD_CLK);

        for (i = (0x1 << (cnt - 1)); i; i >>= 1) {
                if (bits & i)
                        SIO_SET(VR_MIICMD_DATAIN);
                else
                        SIO_CLR(VR_MIICMD_DATAIN);
                DELAY(1);
                SIO_CLR(VR_MIICMD_CLK);
                DELAY(1);
                SIO_SET(VR_MIICMD_CLK);
        }
}
#endif

/*
 * Read an PHY register through the MII.
 */
static int
vr_mii_readreg(struct vr_softc *sc, struct vr_mii_frame *frame)
#ifdef VR_USESWSHIFT    
{
        int i, ack;

        /* Set up frame for RX. */
        frame->mii_stdelim = VR_MII_STARTDELIM;
        frame->mii_opcode = VR_MII_READOP;
        frame->mii_turnaround = 0;
        frame->mii_data = 0;
        
        CSR_WRITE_1(sc, VR_MIICMD, 0);
        VR_SETBIT(sc, VR_MIICMD, VR_MIICMD_DIRECTPGM);

        /* Turn on data xmit. */
        SIO_SET(VR_MIICMD_DIR);

        vr_mii_sync(sc);

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

        /* Idle bit. */
        SIO_CLR((VR_MIICMD_CLK|VR_MIICMD_DATAIN));
        DELAY(1);
        SIO_SET(VR_MIICMD_CLK);
        DELAY(1);

        /* Turn off xmit. */
        SIO_CLR(VR_MIICMD_DIR);

        /* Check for ack */
        SIO_CLR(VR_MIICMD_CLK);
        DELAY(1);
        ack = CSR_READ_4(sc, VR_MIICMD) & VR_MIICMD_DATAOUT;
        SIO_SET(VR_MIICMD_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++) {
                        SIO_CLR(VR_MIICMD_CLK);
                        DELAY(1);
                        SIO_SET(VR_MIICMD_CLK);
                        DELAY(1);
                }
                goto fail;
        }

        for (i = 0x8000; i; i >>= 1) {
                SIO_CLR(VR_MIICMD_CLK);
                DELAY(1);
                if (!ack) {
                        if (CSR_READ_4(sc, VR_MIICMD) & VR_MIICMD_DATAOUT)
                                frame->mii_data |= i;
                        DELAY(1);
                }
                SIO_SET(VR_MIICMD_CLK);
                DELAY(1);
        }

fail:
        SIO_CLR(VR_MIICMD_CLK);
        DELAY(1);
        SIO_SET(VR_MIICMD_CLK);
        DELAY(1);

        if (ack)
                return(1);
        return(0);
}
#else
{
        int i;

        /* Set the PHY address. */
        CSR_WRITE_1(sc, VR_PHYADDR, (CSR_READ_1(sc, VR_PHYADDR)& 0xe0)|
            frame->mii_phyaddr);

        /* Set the register address. */
        CSR_WRITE_1(sc, VR_MIIADDR, frame->mii_regaddr);
        VR_SETBIT(sc, VR_MIICMD, VR_MIICMD_READ_ENB);
        
        for (i = 0; i < 10000; i++) {
                if ((CSR_READ_1(sc, VR_MIICMD) & VR_MIICMD_READ_ENB) == 0)
                        break;
                DELAY(1);
        }
        frame->mii_data = CSR_READ_2(sc, VR_MIIDATA);

        return(0);
}
#endif


/*
 * Write to a PHY register through the MII.
 */
static int
vr_mii_writereg(struct vr_softc *sc, struct vr_mii_frame *frame)
#ifdef VR_USESWSHIFT    
{
        CSR_WRITE_1(sc, VR_MIICMD, 0);
        VR_SETBIT(sc, VR_MIICMD, VR_MIICMD_DIRECTPGM);

        /* Set up frame for TX. */
        frame->mii_stdelim = VR_MII_STARTDELIM;
        frame->mii_opcode = VR_MII_WRITEOP;
        frame->mii_turnaround = VR_MII_TURNAROUND;
        
        /* Turn on data output. */
        SIO_SET(VR_MIICMD_DIR);

        vr_mii_sync(sc);

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

        /* Idle bit. */
        SIO_SET(VR_MIICMD_CLK);
        DELAY(1);
        SIO_CLR(VR_MIICMD_CLK);
        DELAY(1);

        /* Turn off xmit. */
        SIO_CLR(VR_MIICMD_DIR);

        return(0);
}
#else
{
        int i;

        /* Set the PHY-adress */
        CSR_WRITE_1(sc, VR_PHYADDR, (CSR_READ_1(sc, VR_PHYADDR)& 0xe0)|
                    frame->mii_phyaddr);

        /* Set the register address and data to write. */
        CSR_WRITE_1(sc, VR_MIIADDR, frame->mii_regaddr);
        CSR_WRITE_2(sc, VR_MIIDATA, frame->mii_data);

        VR_SETBIT(sc, VR_MIICMD, VR_MIICMD_WRITE_ENB);

        for (i = 0; i < 10000; i++) {
                if ((CSR_READ_1(sc, VR_MIICMD) & VR_MIICMD_WRITE_ENB) == 0)
                        break;
                DELAY(1);
        }
        return(0);
}
#endif

static int
vr_miibus_readreg(device_t dev, int phy, int reg)
{
        struct vr_mii_frame frame;
        struct vr_softc *sc;

        sc = device_get_softc(dev);

        switch (sc->vr_revid) {
        case REV_ID_VT6102_APOLLO:
                if (phy != 1)
                        return(0);
                break;
        default:
                break;
        }

        bzero(&frame, sizeof(frame));

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

        return(frame.mii_data);
}

static int
vr_miibus_writereg(device_t dev, int phy, int reg, int data)
{
        struct vr_mii_frame frame;
        struct vr_softc *sc;

        sc = device_get_softc(dev);

        switch (sc->vr_revid) {
        case REV_ID_VT6102_APOLLO:
                if (phy != 1)
                        return 0;
                break;
        default:
                break;
        }

        bzero(&frame, sizeof(frame));

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

        vr_mii_writereg(sc, &frame);

        return(0);
}

static void
vr_miibus_statchg(device_t dev)
{
        struct mii_data *mii;
        struct vr_softc *sc;

        sc = device_get_softc(dev);
        mii = device_get_softc(sc->vr_miibus);
        vr_setcfg(sc, mii->mii_media_active);
}

/*
 * Program the 64-bit multicast hash filter.
 */
static void
vr_setmulti(struct vr_softc *sc)
{
        struct ifnet *ifp;
        uint32_t hashes[2] = { 0, 0 };
        struct ifmultiaddr *ifma;
        uint8_t rxfilt;
        int mcnt = 0;

        ifp = &sc->arpcom.ac_if;

        rxfilt = CSR_READ_1(sc, VR_RXCFG);

        if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC) {
                rxfilt |= VR_RXCFG_RX_MULTI;
                CSR_WRITE_1(sc, VR_RXCFG, rxfilt);
                CSR_WRITE_4(sc, VR_MAR0, 0xFFFFFFFF);
                CSR_WRITE_4(sc, VR_MAR1, 0xFFFFFFFF);
                return;
        }

        /* First, zero out all the existing hash bits. */
        CSR_WRITE_4(sc, VR_MAR0, 0);
        CSR_WRITE_4(sc, VR_MAR1, 0);

        /* Now program new ones. */
        TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                int h;

                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;

                /* use the lower 6 bits */
                h = (ether_crc32_be(
                        LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
                        ETHER_ADDR_LEN) >> 26) & 0x0000003F;
                if (h < 32)
                        hashes[0] |= (1 << h);
                else
                        hashes[1] |= (1 << (h - 32));
                mcnt++;
        }

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

        CSR_WRITE_4(sc, VR_MAR0, hashes[0]);
        CSR_WRITE_4(sc, VR_MAR1, hashes[1]);
        CSR_WRITE_1(sc, VR_RXCFG, rxfilt);
}

/*
 * In order to fiddle with the
 * 'full-duplex' and '100Mbps' bits in the netconfig register, we
 * first have to put the transmit and/or receive logic in the idle state.
 */
static void
vr_setcfg(struct vr_softc *sc, int media)
{
        int restart = 0;

        if (CSR_READ_2(sc, VR_COMMAND) & (VR_CMD_TX_ON|VR_CMD_RX_ON)) {
                restart = 1;
                VR_CLRBIT16(sc, VR_COMMAND, (VR_CMD_TX_ON|VR_CMD_RX_ON));
        }

        if ((media & IFM_GMASK) == IFM_FDX)
                VR_SETBIT16(sc, VR_COMMAND, VR_CMD_FULLDUPLEX);
        else
                VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_FULLDUPLEX);

        if (restart)
                VR_SETBIT16(sc, VR_COMMAND, VR_CMD_TX_ON|VR_CMD_RX_ON);
}

static void
vr_reset(struct vr_softc *sc)
{
        int i;

        VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RESET);

        for (i = 0; i < VR_TIMEOUT; i++) {
                DELAY(10);
                if (!(CSR_READ_2(sc, VR_COMMAND) & VR_CMD_RESET))
                        break;
        }
        if (i == VR_TIMEOUT) {
                struct ifnet *ifp = &sc->arpcom.ac_if;

                if (sc->vr_revid < REV_ID_VT3065_A) {
                        if_printf(ifp, "reset never completed!\n");
                } else {
                        /* Use newer force reset command */
                        if_printf(ifp, "Using force reset command.\n");
                        VR_SETBIT(sc, VR_MISC_CR1, VR_MISCCR1_FORSRST);
                }
        }

        /* Wait a little while for the chip to get its brains in order. */
        DELAY(1000);
}

/*
 * Probe for a VIA Rhine chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 */
static int
vr_probe(device_t dev)
{
        struct vr_type *t;
        uint16_t vid, did;

        vid = pci_get_vendor(dev);
        did = pci_get_device(dev);

        for (t = vr_devs; t->vr_name != NULL; ++t) {
                if (vid == t->vr_vid && did == t->vr_did) {
                        device_set_desc(dev, t->vr_name);
                        return(0);
                }
        }

        return(ENXIO);
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
vr_attach(device_t dev)
{
        int i;
        uint8_t eaddr[ETHER_ADDR_LEN];
        struct vr_softc *sc;
        struct ifnet *ifp;
        int error = 0, rid;

        sc = device_get_softc(dev);
        callout_init(&sc->vr_stat_timer);

        /*
         * Handle power management nonsense.
         */
        if (pci_get_powerstate(dev) != PCI_POWERSTATE_D0) {
                uint32_t iobase, membase, irq;

                /* Save important PCI config data. */
                iobase = pci_read_config(dev, VR_PCI_LOIO, 4);
                membase = pci_read_config(dev, VR_PCI_LOMEM, 4);
                irq = pci_read_config(dev, VR_PCI_INTLINE, 4);

                /* Reset the power state. */
                device_printf(dev, "chip is in %s power mode "
                    "-- setting to D0\n",
                    pci_powerstate_to_str(pci_get_powerstate(dev)));
                pci_set_powerstate(dev, PCI_POWERSTATE_D0);

                /* Restore PCI config data. */
                pci_write_config(dev, VR_PCI_LOIO, iobase, 4);
                pci_write_config(dev, VR_PCI_LOMEM, membase, 4);
                pci_write_config(dev, VR_PCI_INTLINE, irq, 4);
        }

        pci_enable_busmaster(dev);

        sc->vr_revid = pci_get_revid(dev);

        rid = VR_RID;
        sc->vr_res = bus_alloc_resource_any(dev, VR_RES, &rid, RF_ACTIVE);

        if (sc->vr_res == NULL) {
                device_printf(dev, "couldn't map ports/memory\n");
                return ENXIO;
        }

        sc->vr_btag = rman_get_bustag(sc->vr_res);
        sc->vr_bhandle = rman_get_bushandle(sc->vr_res);

        /* Allocate interrupt */
        rid = 0;
        sc->vr_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
                                            RF_SHAREABLE | RF_ACTIVE);

        if (sc->vr_irq == NULL) {
                device_printf(dev, "couldn't map interrupt\n");
                error = ENXIO;
                goto fail;
        }

        /*
         * Windows may put the chip in suspend mode when it
         * shuts down. Be sure to kick it in the head to wake it
         * up again.
         */
        VR_CLRBIT(sc, VR_STICKHW, (VR_STICKHW_DS0|VR_STICKHW_DS1));

        ifp = &sc->arpcom.ac_if;
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));

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

        /*
         * Turn on bit2 (MIION) in PCI configuration register 0x53 during
         * initialization and disable AUTOPOLL.
         */
        pci_write_config(dev, VR_PCI_MODE,
            pci_read_config(dev, VR_PCI_MODE, 4) | (VR_MODE3_MIION << 24), 4);
        VR_CLRBIT(sc, VR_MIICMD, VR_MIICMD_AUTOPOLL);

        /*
         * Get station address. The way the Rhine chips work,
         * you're not allowed to directly access the EEPROM once
         * they've been programmed a special way. Consequently,
         * we need to read the node address from the PAR0 and PAR1
         * registers.
         */
        VR_SETBIT(sc, VR_EECSR, VR_EECSR_LOAD);
        DELAY(200);
        for (i = 0; i < ETHER_ADDR_LEN; i++)
                eaddr[i] = CSR_READ_1(sc, VR_PAR0 + i);

        sc->vr_ldata = contigmalloc(sizeof(struct vr_list_data), M_DEVBUF,
            M_WAITOK | M_ZERO, 0, 0xffffffff, PAGE_SIZE, 0);

        if (sc->vr_ldata == NULL) {
                device_printf(dev, "no memory for list buffers!\n");
                error = ENXIO;
                goto fail;
        }

        /* Initialize TX buffer */
        sc->vr_cdata.vr_tx_buf = contigmalloc(VR_TX_BUF_SIZE, M_DEVBUF,
            M_WAITOK, 0, 0xffffffff, PAGE_SIZE, 0);
        if (sc->vr_cdata.vr_tx_buf == NULL) {
                device_printf(dev, "can't allocate tx buffer!\n");
                error = ENXIO;
                goto fail;
        }

        /* Set various TX indexes to invalid value */
        sc->vr_cdata.vr_tx_free_idx = -1;
        sc->vr_cdata.vr_tx_tail_idx = -1;
        sc->vr_cdata.vr_tx_head_idx = -1;


        ifp->if_softc = sc;
        ifp->if_mtu = ETHERMTU;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = vr_ioctl;
        ifp->if_start = vr_start;
#ifdef IFPOLL_ENABLE
        ifp->if_npoll = vr_npoll;
#endif
        ifp->if_watchdog = vr_watchdog;
        ifp->if_init = vr_init;
        ifp->if_baudrate = 10000000;
        ifq_set_maxlen(&ifp->if_snd, VR_TX_LIST_CNT - 1);
        ifq_set_ready(&ifp->if_snd);

        /*
         * Do MII setup.
         */
        if (mii_phy_probe(dev, &sc->vr_miibus,
            vr_ifmedia_upd, vr_ifmedia_sts)) {
                if_printf(ifp, "MII without any phy!\n");
                error = ENXIO;
                goto fail;
        }

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

        ifq_set_cpuid(&ifp->if_snd, rman_get_cpuid(sc->vr_irq));

#ifdef IFPOLL_ENABLE
        ifpoll_compat_setup(&sc->vr_npoll, NULL, NULL, device_get_unit(dev),
            ifp->if_serializer);
#endif

        error = bus_setup_intr(dev, sc->vr_irq, INTR_MPSAFE,
                               vr_intr, sc, &sc->vr_intrhand, 
                               ifp->if_serializer);
        if (error) {
                device_printf(dev, "couldn't set up irq\n");
                ether_ifdetach(ifp);
                goto fail;
        }

        return 0;

fail:
        vr_detach(dev);
        return(error);
}

static int
vr_detach(device_t dev)
{
        struct vr_softc *sc = device_get_softc(dev);
        struct ifnet *ifp = &sc->arpcom.ac_if;

        if (device_is_attached(dev)) {
                lwkt_serialize_enter(ifp->if_serializer);
                vr_stop(sc);
                bus_teardown_intr(dev, sc->vr_irq, sc->vr_intrhand);
                lwkt_serialize_exit(ifp->if_serializer);

                ether_ifdetach(ifp);
        }
        if (sc->vr_miibus != NULL)
                device_delete_child(dev, sc->vr_miibus);
        bus_generic_detach(dev);

        if (sc->vr_irq != NULL)
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->vr_irq);
        if (sc->vr_res != NULL)
                bus_release_resource(dev, VR_RES, VR_RID, sc->vr_res);
        if (sc->vr_ldata != NULL)
                contigfree(sc->vr_ldata, sizeof(struct vr_list_data), M_DEVBUF);
        if (sc->vr_cdata.vr_tx_buf != NULL)
                contigfree(sc->vr_cdata.vr_tx_buf, VR_TX_BUF_SIZE, M_DEVBUF);

        return(0);
}

/*
 * Initialize the transmit descriptors.
 */
static int
vr_list_tx_init(struct vr_softc *sc)
{
        struct vr_chain_data *cd;
        struct vr_list_data *ld;
        struct vr_chain *tx_chain;
        int i;

        cd = &sc->vr_cdata;
        ld = sc->vr_ldata;
        tx_chain = cd->vr_tx_chain;

        for (i = 0; i < VR_TX_LIST_CNT; i++) {
                tx_chain[i].vr_ptr = &ld->vr_tx_list[i];
                if (i == (VR_TX_LIST_CNT - 1))
                        tx_chain[i].vr_next_idx = 0;
                else
                        tx_chain[i].vr_next_idx = i + 1;
        }

        for (i = 0; i < VR_TX_LIST_CNT; ++i) {
                void *tx_buf;
                int next_idx;

                tx_buf = VR_TX_BUF(sc, i);
                next_idx = tx_chain[i].vr_next_idx;

                tx_chain[i].vr_next_desc_paddr =
                        vtophys(tx_chain[next_idx].vr_ptr);
                tx_chain[i].vr_buf_paddr = vtophys(tx_buf);
        }

        cd->vr_tx_free_idx = 0;
        cd->vr_tx_tail_idx = cd->vr_tx_head_idx = -1;

        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
vr_list_rx_init(struct vr_softc *sc)
{
        struct vr_chain_data *cd;
        struct vr_list_data *ld;
        int i, nexti;

        cd = &sc->vr_cdata;
        ld = sc->vr_ldata;

        for (i = 0; i < VR_RX_LIST_CNT; i++) {
                cd->vr_rx_chain[i].vr_ptr = (struct vr_desc *)&ld->vr_rx_list[i];
                if (vr_newbuf(sc, &cd->vr_rx_chain[i], NULL) == ENOBUFS)
                        return(ENOBUFS);
                if (i == (VR_RX_LIST_CNT - 1))
                        nexti = 0;
                else
                        nexti = i + 1;
                cd->vr_rx_chain[i].vr_nextdesc = &cd->vr_rx_chain[nexti];
                ld->vr_rx_list[i].vr_next = vtophys(&ld->vr_rx_list[nexti]);
        }

        cd->vr_rx_head = &cd->vr_rx_chain[0];

        return(0);
}

/*
 * Initialize an RX descriptor and attach an MBUF cluster.
 * Note: the length fields are only 11 bits wide, which means the
 * largest size we can specify is 2047. This is important because
 * MCLBYTES is 2048, so we have to subtract one otherwise we'll
 * overflow the field and make a mess.
 */
static int
vr_newbuf(struct vr_softc *sc, struct vr_chain_onefrag *c, struct mbuf *m)
{
        struct mbuf *m_new = NULL;

        if (m == NULL) {
                m_new = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
                if (m_new == NULL)
                        return (ENOBUFS);
                m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
        } else {
                m_new = m;
                m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
                m_new->m_data = m_new->m_ext.ext_buf;
        }

        m_adj(m_new, sizeof(uint64_t));

        c->vr_mbuf = m_new;
        c->vr_ptr->vr_status = VR_RXSTAT;
        c->vr_ptr->vr_data = vtophys(mtod(m_new, caddr_t));
        c->vr_ptr->vr_ctl = VR_RXCTL | VR_RXLEN;

        return(0);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void
vr_rxeof(struct vr_softc *sc)
{
        struct mbuf *m;
        struct ifnet *ifp;
        struct vr_chain_onefrag *cur_rx;
        int total_len = 0;
        uint32_t rxstat;

        ifp = &sc->arpcom.ac_if;

        while(!((rxstat = sc->vr_cdata.vr_rx_head->vr_ptr->vr_status) &
                                                        VR_RXSTAT_OWN)) {
                struct mbuf *m0 = NULL;

                cur_rx = sc->vr_cdata.vr_rx_head;
                sc->vr_cdata.vr_rx_head = cur_rx->vr_nextdesc;
                m = cur_rx->vr_mbuf;

                /*
                 * 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 & VR_RXSTAT_RXERR) {
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        if_printf(ifp, "rx error (%02x):", rxstat & 0x000000ff);
                        if (rxstat & VR_RXSTAT_CRCERR)
                                kprintf(" crc error");
                        if (rxstat & VR_RXSTAT_FRAMEALIGNERR)
                                kprintf(" frame alignment error\n");
                        if (rxstat & VR_RXSTAT_FIFOOFLOW)
                                kprintf(" FIFO overflow");
                        if (rxstat & VR_RXSTAT_GIANT)
                                kprintf(" received giant packet");
                        if (rxstat & VR_RXSTAT_RUNT)
                                kprintf(" received runt packet");
                        if (rxstat & VR_RXSTAT_BUSERR)
                                kprintf(" system bus error");
                        if (rxstat & VR_RXSTAT_BUFFERR)
                                kprintf("rx buffer error");
                        kprintf("\n");
                        vr_newbuf(sc, cur_rx, m);
                        continue;
                }

                /* No errors; receive the packet. */    
                total_len = VR_RXBYTES(cur_rx->vr_ptr->vr_status);

                /*
                 * XXX The VIA Rhine chip includes the CRC with every
                 * received frame, and there's no way to turn this
                 * behavior off (at least, I can't find anything in
                 * the manual that explains how to do it) so we have
                 * to trim off the CRC manually.
                 */
                total_len -= ETHER_CRC_LEN;

                m0 = m_devget(mtod(m, char *) - ETHER_ALIGN,
                              total_len + ETHER_ALIGN, 0, ifp);
                vr_newbuf(sc, cur_rx, m);
                if (m0 == NULL) {
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        continue;
                }
                m_adj(m0, ETHER_ALIGN);
                m = m0;

                IFNET_STAT_INC(ifp, ipackets, 1);
                ifp->if_input(ifp, m, NULL, -1);
        }
}

static void
vr_rxeoc(struct vr_softc *sc)
{
        struct ifnet *ifp;
        int i;

        ifp = &sc->arpcom.ac_if;

        IFNET_STAT_INC(ifp, ierrors, 1);

        VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);      
        DELAY(10000);

        /* Wait for receiver to stop */
        for (i = 0x400;
             i && (CSR_READ_2(sc, VR_COMMAND) & VR_CMD_RX_ON);
             i--)
                ;       /* Wait for receiver to stop */

        if (i == 0) {
                if_printf(ifp, "rx shutdown error!\n");
                sc->vr_flags |= VR_F_RESTART;
                return;
        }

        vr_rxeof(sc);

        CSR_WRITE_4(sc, VR_RXADDR, vtophys(sc->vr_cdata.vr_rx_head->vr_ptr));
        VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);
        VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_GO);
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */
static void
vr_txeof(struct vr_softc *sc)
{
        struct vr_chain_data *cd;
        struct vr_chain *tx_chain;
        struct ifnet *ifp;

        ifp = &sc->arpcom.ac_if;
        cd = &sc->vr_cdata;

        /* Reset the timeout timer; if_txeoc will clear it. */
        ifp->if_timer = 5;

        /* Sanity check. */
        if (cd->vr_tx_head_idx == -1)
                return;

        tx_chain = cd->vr_tx_chain;

        /*
         * Go through our tx list and free mbufs for those
         * frames that have been transmitted.
         */
        while(tx_chain[cd->vr_tx_head_idx].vr_buf != NULL) {
                struct vr_chain *cur_tx;
                uint32_t txstat;
                int i;

                cur_tx = &tx_chain[cd->vr_tx_head_idx];
                txstat = cur_tx->vr_ptr->vr_status;

                if ((txstat & VR_TXSTAT_ABRT) ||
                    (txstat & VR_TXSTAT_UDF)) {
                        for (i = 0x400;
                             i && (CSR_READ_2(sc, VR_COMMAND) & VR_CMD_TX_ON);
                             i--)
                                ;       /* Wait for chip to shutdown */
                        if (i == 0) {
                                if_printf(ifp, "tx shutdown timeout\n");
                                sc->vr_flags |= VR_F_RESTART;
                                break;
                        }
                        VR_TXOWN(cur_tx) = VR_TXSTAT_OWN;
                        CSR_WRITE_4(sc, VR_TXADDR, vtophys(cur_tx->vr_ptr));
                        break;
                }

                if (txstat & VR_TXSTAT_OWN)
                        break;

                if (txstat & VR_TXSTAT_ERRSUM) {
                        IFNET_STAT_INC(ifp, oerrors, 1);
                        if (txstat & VR_TXSTAT_DEFER)
                                IFNET_STAT_INC(ifp, collisions, 1);
                        if (txstat & VR_TXSTAT_LATECOLL)
                                IFNET_STAT_INC(ifp, collisions, 1);
                }

                IFNET_STAT_INC(ifp, collisions,
                    (txstat & VR_TXSTAT_COLLCNT) >> 3);

                IFNET_STAT_INC(ifp, opackets, 1);
                cur_tx->vr_buf = NULL;

                if (cd->vr_tx_head_idx == cd->vr_tx_tail_idx) {
                        cd->vr_tx_head_idx = -1;
                        cd->vr_tx_tail_idx = -1;
                        break;
                }

                cd->vr_tx_head_idx = cur_tx->vr_next_idx;
        }
}

/*
 * TX 'end of channel' interrupt handler.
 */
static void
vr_txeoc(struct vr_softc *sc)
{
        struct ifnet *ifp;

        ifp = &sc->arpcom.ac_if;

        if (sc->vr_cdata.vr_tx_head_idx == -1) {
                ifq_clr_oactive(&ifp->if_snd);
                sc->vr_cdata.vr_tx_tail_idx = -1;
                ifp->if_timer = 0;
        }
}

static void
vr_tick(void *xsc)
{
        struct vr_softc *sc = xsc;
        struct ifnet *ifp = &sc->arpcom.ac_if;
        struct mii_data *mii;

        lwkt_serialize_enter(ifp->if_serializer);

        if (sc->vr_flags & VR_F_RESTART) {
                if_printf(&sc->arpcom.ac_if, "restarting\n");
                vr_stop(sc);
                vr_reset(sc);
                vr_init(sc);
                sc->vr_flags &= ~VR_F_RESTART;
        }

        mii = device_get_softc(sc->vr_miibus);
        mii_tick(mii);

        callout_reset(&sc->vr_stat_timer, hz, vr_tick, sc);

        lwkt_serialize_exit(ifp->if_serializer);
}

static void
vr_intr(void *arg)
{
        struct vr_softc *sc;
        struct ifnet *ifp;
        uint16_t status;

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

        /* Supress unwanted interrupts. */
        if (!(ifp->if_flags & IFF_UP)) {
                vr_stop(sc);
                return;
        }

        /* Disable interrupts. */
        if ((ifp->if_flags & IFF_NPOLLING) == 0)
                CSR_WRITE_2(sc, VR_IMR, 0x0000);

        for (;;) {
                status = CSR_READ_2(sc, VR_ISR);
                if (status)
                        CSR_WRITE_2(sc, VR_ISR, status);

                if ((status & VR_INTRS) == 0)
                        break;

                if (status & VR_ISR_RX_OK)
                        vr_rxeof(sc);

                if (status & VR_ISR_RX_DROPPED) {
                        if_printf(ifp, "rx packet lost\n");
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        }

                if ((status & VR_ISR_RX_ERR) || (status & VR_ISR_RX_NOBUF) ||
                    (status & VR_ISR_RX_OFLOW)) {
                        if_printf(ifp, "receive error (%04x)", status);
                        if (status & VR_ISR_RX_NOBUF)
                                kprintf(" no buffers");
                        if (status & VR_ISR_RX_OFLOW)
                                kprintf(" overflow");
                        if (status & VR_ISR_RX_DROPPED)
                                kprintf(" packet lost");
                        kprintf("\n");
                        vr_rxeoc(sc);
                }

                if ((status & VR_ISR_BUSERR) || (status & VR_ISR_TX_UNDERRUN)) {
                        vr_reset(sc);
                        vr_init(sc);
                        break;
                }

                if ((status & VR_ISR_TX_OK) || (status & VR_ISR_TX_ABRT) ||
                    (status & VR_ISR_TX_ABRT2) || (status & VR_ISR_UDFI)) {
                        vr_txeof(sc);
                        if ((status & VR_ISR_UDFI) ||
                            (status & VR_ISR_TX_ABRT2) ||
                            (status & VR_ISR_TX_ABRT)) {
                                IFNET_STAT_INC(ifp, oerrors, 1);
                                if (sc->vr_cdata.vr_tx_head_idx != -1) {
                                        VR_SETBIT16(sc, VR_COMMAND,
                                                    VR_CMD_TX_ON);
                                        VR_SETBIT16(sc, VR_COMMAND,
                                                    VR_CMD_TX_GO);
                                }
                        } else {
                                vr_txeoc(sc);
                        }
                }

        }

        /* Re-enable interrupts. */
        if ((ifp->if_flags & IFF_NPOLLING) == 0)
                CSR_WRITE_2(sc, VR_IMR, VR_INTRS);

        if (!ifq_is_empty(&ifp->if_snd))
                if_devstart(ifp);
}

/*
 * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
 * pointers to the fragment pointers.
 */
static int
vr_encap(struct vr_softc *sc, int chain_idx, struct mbuf *m_head)
{
        struct vr_chain *c;
        struct vr_desc *f;
        caddr_t tx_buf;
        int len;

        KASSERT(chain_idx >= 0 && chain_idx < VR_TX_LIST_CNT,
                ("%s: chain idx(%d) out of range 0-%d",
                 sc->arpcom.ac_if.if_xname, chain_idx, VR_TX_LIST_CNT));

        /*
         * The VIA Rhine wants packet buffers to be longword
         * aligned, but very often our mbufs aren't. Rather than
         * waste time trying to decide when to copy and when not
         * to copy, just do it all the time.
         */
        tx_buf = VR_TX_BUF(sc, chain_idx);
        m_copydata(m_head, 0, m_head->m_pkthdr.len, tx_buf);
        len = m_head->m_pkthdr.len;

        /*
         * The Rhine chip doesn't auto-pad, so we have to make
         * sure to pad short frames out to the minimum frame length
         * ourselves.
         */
        if (len < VR_MIN_FRAMELEN) {
                bzero(tx_buf + len, VR_MIN_FRAMELEN - len);
                len = VR_MIN_FRAMELEN;
        }

        c = &sc->vr_cdata.vr_tx_chain[chain_idx];
        c->vr_buf = tx_buf;

        f = c->vr_ptr;
        f->vr_data = c->vr_buf_paddr;
        f->vr_ctl = len;
        f->vr_ctl |= (VR_TXCTL_TLINK | VR_TXCTL_FIRSTFRAG);
        f->vr_ctl |= (VR_TXCTL_LASTFRAG | VR_TXCTL_FINT);
        f->vr_status = 0;
        f->vr_next = c->vr_next_desc_paddr;

        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
vr_start(struct ifnet *ifp, struct ifaltq_subque *ifsq)
{
        struct vr_softc *sc;
        struct vr_chain_data *cd;
        struct vr_chain *tx_chain;
        int cur_tx_idx, start_tx_idx, prev_tx_idx;

        ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);

        if ((ifp->if_flags & IFF_RUNNING) == 0 || ifq_is_oactive(&ifp->if_snd))
                return;

        sc = ifp->if_softc;
        cd = &sc->vr_cdata;
        tx_chain = cd->vr_tx_chain;

        start_tx_idx = cd->vr_tx_free_idx;
        cur_tx_idx = prev_tx_idx = -1;

        /* Check for an available queue slot. If there are none, punt. */
        if (tx_chain[start_tx_idx].vr_buf != NULL) {
                ifq_set_oactive(&ifp->if_snd);
                return;
        }

        while (tx_chain[cd->vr_tx_free_idx].vr_buf == NULL) {
                struct mbuf *m_head;
                struct vr_chain *cur_tx;

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

                /* Pick a descriptor off the free list. */
                cur_tx_idx = cd->vr_tx_free_idx;
                cur_tx = &tx_chain[cur_tx_idx];

                /* Pack the data into the descriptor. */
                if (vr_encap(sc, cur_tx_idx, m_head)) {
                        ifq_set_oactive(&ifp->if_snd);
                        cur_tx_idx = prev_tx_idx;
                        break;
                }

                /* XXX */
                if (cur_tx_idx != start_tx_idx)
                        VR_TXOWN(cur_tx) = VR_TXSTAT_OWN;

                BPF_MTAP(ifp, m_head);
                m_freem(m_head);

                VR_TXOWN(cur_tx) = VR_TXSTAT_OWN;
                VR_SETBIT16(sc, VR_COMMAND, /*VR_CMD_TX_ON|*/VR_CMD_TX_GO);

                /* Iff everything went OK, we bump up free index. */
                prev_tx_idx = cur_tx_idx;
                cd->vr_tx_free_idx = cur_tx->vr_next_idx;
        }

        /* If there are no frames queued, bail. */
        if (cur_tx_idx == -1)
                return;

        sc->vr_cdata.vr_tx_tail_idx = cur_tx_idx;

        if (sc->vr_cdata.vr_tx_head_idx == -1)
                sc->vr_cdata.vr_tx_head_idx = start_tx_idx;

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

static void
vr_init(void *xsc)
{
        struct vr_softc *sc = xsc;
        struct ifnet *ifp = &sc->arpcom.ac_if;
        struct mii_data *mii;
        int i;

        mii = device_get_softc(sc->vr_miibus);

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

        /* Set our station address. */
        for (i = 0; i < ETHER_ADDR_LEN; i++)
                CSR_WRITE_1(sc, VR_PAR0 + i, sc->arpcom.ac_enaddr[i]);

        /* Set DMA size. */
        VR_CLRBIT(sc, VR_BCR0, VR_BCR0_DMA_LENGTH);
        VR_SETBIT(sc, VR_BCR0, VR_BCR0_DMA_STORENFWD);

        /*
         * BCR0 and BCR1 can override the RXCFG and TXCFG registers,
         * so we must set both.
         */
        VR_CLRBIT(sc, VR_BCR0, VR_BCR0_RX_THRESH);
        VR_SETBIT(sc, VR_BCR0, VR_BCR0_RXTHRESH128BYTES);

        VR_CLRBIT(sc, VR_BCR1, VR_BCR1_TX_THRESH);
        VR_SETBIT(sc, VR_BCR1, VR_BCR1_TXTHRESHSTORENFWD);

        VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_THRESH);
        VR_SETBIT(sc, VR_RXCFG, VR_RXTHRESH_128BYTES);

        VR_CLRBIT(sc, VR_TXCFG, VR_TXCFG_TX_THRESH);
        VR_SETBIT(sc, VR_TXCFG, VR_TXTHRESH_STORENFWD);

        /* Init circular RX list. */
        if (vr_list_rx_init(sc) == ENOBUFS) {
                vr_stop(sc);
                if_printf(ifp, "initialization failed: no memory for rx buffers\n");
                return;
        }

        /* Init tx descriptors. */
        vr_list_tx_init(sc);

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                VR_SETBIT(sc, VR_RXCFG, VR_RXCFG_RX_PROMISC);
        else
                VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_PROMISC);

        /* Set capture broadcast bit to capture broadcast frames. */
        if (ifp->if_flags & IFF_BROADCAST)
                VR_SETBIT(sc, VR_RXCFG, VR_RXCFG_RX_BROAD);
        else
                VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_BROAD);

        /*
         * Program the multicast filter, if necessary.
         */
        vr_setmulti(sc);

        /*
         * Load the address of the RX list.
         */
        CSR_WRITE_4(sc, VR_RXADDR, vtophys(sc->vr_cdata.vr_rx_head->vr_ptr));

        /* Enable receiver and transmitter. */
        CSR_WRITE_2(sc, VR_COMMAND, VR_CMD_TX_NOPOLL|VR_CMD_START|
                                    VR_CMD_TX_ON|VR_CMD_RX_ON|
                                    VR_CMD_RX_GO);

        CSR_WRITE_4(sc, VR_TXADDR, vtophys(&sc->vr_ldata->vr_tx_list[0]));

        /*
         * Enable interrupts, unless we are polling.
         */
        CSR_WRITE_2(sc, VR_ISR, 0xFFFF);
#ifdef IFPOLL_ENABLE
        if ((ifp->if_flags & IFF_NPOLLING) == 0)
#endif
                CSR_WRITE_2(sc, VR_IMR, VR_INTRS);

        mii_mediachg(mii);

        ifp->if_flags |= IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);

        callout_reset(&sc->vr_stat_timer, hz, vr_tick, sc);
}

/*
 * Set media options.
 */
static int
vr_ifmedia_upd(struct ifnet *ifp)
{
        struct vr_softc *sc;

        sc = ifp->if_softc;

        if (ifp->if_flags & IFF_UP)
                vr_init(sc);

        return(0);
}

/*
 * Report current media status.
 */
static void
vr_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct vr_softc *sc;
        struct mii_data *mii;

        sc = ifp->if_softc;
        mii = device_get_softc(sc->vr_miibus);
        mii_pollstat(mii);
        ifmr->ifm_active = mii->mii_media_active;
        ifmr->ifm_status = mii->mii_media_status;
}

static int
vr_ioctl(struct ifnet *ifp, u_long command, caddr_t data, struct ucred *cr)
{
        struct vr_softc *sc = ifp->if_softc;
        struct ifreq *ifr = (struct ifreq *) data;
        struct mii_data *mii;
        int error = 0;

        switch(command) {
        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP) {
                        vr_init(sc);
                } else {
                        if (ifp->if_flags & IFF_RUNNING)
                                vr_stop(sc);
                }
                error = 0;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                vr_setmulti(sc);
                error = 0;
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                mii = device_get_softc(sc->vr_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }
        return(error);
}

#ifdef IFPOLL_ENABLE

static void
vr_npoll_compat(struct ifnet *ifp, void *arg __unused, int count __unused)
{
        struct vr_softc *sc = ifp->if_softc;

        ASSERT_SERIALIZED(ifp->if_serializer);
        vr_intr(sc);
}

static void
vr_npoll(struct ifnet *ifp, struct ifpoll_info *info)
{
        struct vr_softc *sc = ifp->if_softc;

        ASSERT_SERIALIZED(ifp->if_serializer);

        if (info != NULL) {
                int cpuid = sc->vr_npoll.ifpc_cpuid;

                info->ifpi_rx[cpuid].poll_func = vr_npoll_compat;
                info->ifpi_rx[cpuid].arg = NULL;
                info->ifpi_rx[cpuid].serializer = ifp->if_serializer;

                if (ifp->if_flags & IFF_RUNNING) {
                        /* disable interrupts */
                        CSR_WRITE_2(sc, VR_IMR, 0x0000);
                }
                ifq_set_cpuid(&ifp->if_snd, cpuid);
        } else {
                if (ifp->if_flags & IFF_RUNNING) {
                        /* enable interrupts */
                        CSR_WRITE_2(sc, VR_IMR, VR_INTRS);
                }
                ifq_set_cpuid(&ifp->if_snd, rman_get_cpuid(sc->vr_irq));
        }
}

#endif  /* IFPOLL_ENABLE */

static void
vr_watchdog(struct ifnet *ifp)
{
        struct vr_softc *sc;

        sc = ifp->if_softc;

        IFNET_STAT_INC(ifp, oerrors, 1);
        if_printf(ifp, "watchdog timeout\n");

        vr_stop(sc);
        vr_reset(sc);
        vr_init(sc);

        if (!ifq_is_empty(&ifp->if_snd))
                if_devstart(ifp);
}

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

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

        callout_stop(&sc->vr_stat_timer);

        VR_SETBIT16(sc, VR_COMMAND, VR_CMD_STOP);
        VR_CLRBIT16(sc, VR_COMMAND, (VR_CMD_RX_ON|VR_CMD_TX_ON));
        CSR_WRITE_2(sc, VR_IMR, 0x0000);
        CSR_WRITE_4(sc, VR_TXADDR, 0x00000000);
        CSR_WRITE_4(sc, VR_RXADDR, 0x00000000);

        /*
         * Free data in the RX lists.
         */
        for (i = 0; i < VR_RX_LIST_CNT; i++) {
                if (sc->vr_cdata.vr_rx_chain[i].vr_mbuf != NULL) {
                        m_freem(sc->vr_cdata.vr_rx_chain[i].vr_mbuf);
                        sc->vr_cdata.vr_rx_chain[i].vr_mbuf = NULL;
                }
        }
        bzero(&sc->vr_ldata->vr_rx_list, sizeof(sc->vr_ldata->vr_rx_list));

        /*
         * Reset the TX list buffer pointers.
         */
        for (i = 0; i < VR_TX_LIST_CNT; i++)
                sc->vr_cdata.vr_tx_chain[i].vr_buf = NULL;

        bzero(&sc->vr_ldata->vr_tx_list, sizeof(sc->vr_ldata->vr_tx_list));

        ifp->if_flags &= ~IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);
}

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

        sc = device_get_softc(dev);

        vr_stop(sc);
}