xref: /freebsd/sys/dev/fxp/if_fxp.c (revision f7788e8e9f0e7e88d774306739c9691b01ac5f08)

/*-
 * Copyright (c) 2001 Jonathan Lemon <jlemon@freebsd.org>
 * Copyright (c) 1995, David Greenman
 * 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 unmodified, 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR OR CONTRIBUTORS 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.
 *
 * $FreeBSD$
 */

/*
 * Intel EtherExpress Pro/100B PCI Fast Ethernet driver
 */

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

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

#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif

#include <net/bpf.h>
#include <sys/sockio.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>

#include <net/ethernet.h>
#include <net/if_arp.h>

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

#include <pci/pcivar.h>
#include <pci/pcireg.h>		/* for PCIM_CMD_xxx */

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

#include <dev/fxp/if_fxpreg.h>
#include <dev/fxp/if_fxpvar.h>

MODULE_DEPEND(fxp, miibus, 1, 1, 1);
#include "miibus_if.h"

/*
 * NOTE!  On the Alpha, we have an alignment constraint.  The
 * card DMAs the packet immediately following the RFA.  However,
 * the first thing in the packet is a 14-byte Ethernet header.
 * This means that the packet is misaligned.  To compensate,
 * we actually offset the RFA 2 bytes into the cluster.  This
 * alignes the packet after the Ethernet header at a 32-bit
 * boundary.  HOWEVER!  This means that the RFA is misaligned!
 */
#define	RFA_ALIGNMENT_FUDGE	2

/*
 * Set initial transmit threshold at 64 (512 bytes). This is
 * increased by 64 (512 bytes) at a time, to maximum of 192
 * (1536 bytes), if an underrun occurs.
 */
static int tx_threshold = 64;

/*
 * The configuration byte map has several undefined fields which
 * must be one or must be zero.  Set up a template for these bits
 * only, (assuming a 82557 chip) leaving the actual configuration
 * to fxp_init.
 *
 * See struct fxp_cb_config for the bit definitions.
 */
static u_char fxp_cb_config_template[] = {
	0x0, 0x0,		/* cb_status */
	0x0, 0x0,		/* cb_command */
	0x0, 0x0, 0x0, 0x0,	/* link_addr */
	0x0,	/*  0 */
	0x0,	/*  1 */
	0x0,	/*  2 */
	0x0,	/*  3 */
	0x0,	/*  4 */
	0x0,	/*  5 */
	0x32,	/*  6 */
	0x0,	/*  7 */
	0x0,	/*  8 */
	0x0,	/*  9 */
	0x6,	/* 10 */
	0x0,	/* 11 */
	0x0,	/* 12 */
	0x0,	/* 13 */
	0xf2,	/* 14 */
	0x48,	/* 15 */
	0x0,	/* 16 */
	0x40,	/* 17 */
	0xf0,	/* 18 */
	0x0,	/* 19 */
	0x3f,	/* 20 */
	0x5	/* 21 */
};

struct fxp_ident {
	u_int16_t	devid;
	char 		*name;
};

/*
 * Claim various Intel PCI device identifiers for this driver.  The
 * sub-vendor and sub-device field are extensively used to identify
 * particular variants, but we don't currently differentiate between
 * them.
 */
static struct fxp_ident fxp_ident_table[] = {
    { 0x1229,		"Intel Pro 10/100B/100+ Ethernet" },
    { 0x2449,		"Intel Pro/100 Ethernet" },
    { 0x1209,		"Intel Embedded 10/100 Ethernet" },
    { 0x1029,		"Intel Pro/100 Ethernet" },
    { 0x1030,		"Intel Pro/100 Ethernet" },
    { 0x1031,		"Intel Pro/100 Ethernet" },
    { 0x1032,		"Intel Pro/100 Ethernet" },
    { 0x1033,		"Intel Pro/100 Ethernet" },
    { 0x1034,		"Intel Pro/100 Ethernet" },
    { 0x1035,		"Intel Pro/100 Ethernet" },
    { 0x1036,		"Intel Pro/100 Ethernet" },
    { 0x1037,		"Intel Pro/100 Ethernet" },
    { 0x1038,		"Intel Pro/100 Ethernet" },
    { 0,		NULL },
};

static int		fxp_probe(device_t dev);
static int		fxp_attach(device_t dev);
static int		fxp_detach(device_t dev);
static int		fxp_shutdown(device_t dev);
static int		fxp_suspend(device_t dev);
static int		fxp_resume(device_t dev);

static void		fxp_intr(void *xsc);
static void 		fxp_init(void *xsc);
static void 		fxp_tick(void *xsc);
static void 		fxp_start(struct ifnet *ifp);
static void		fxp_stop(struct fxp_softc *sc);
static void 		fxp_release(struct fxp_softc *sc);
static int		fxp_ioctl(struct ifnet *ifp, u_long command,
			    caddr_t data);
static void 		fxp_watchdog(struct ifnet *ifp);
static int		fxp_add_rfabuf(struct fxp_softc *sc, struct mbuf *oldm);
static void		fxp_mc_setup(struct fxp_softc *sc);
static u_int16_t	fxp_eeprom_getword(struct fxp_softc *sc, int offset,
			    int autosize);
static void		fxp_autosize_eeprom(struct fxp_softc *sc);
static void		fxp_read_eeprom(struct fxp_softc *sc, u_short *data,
			    int offset, int words);
static int		fxp_ifmedia_upd(struct ifnet *ifp);
static void		fxp_ifmedia_sts(struct ifnet *ifp,
			    struct ifmediareq *ifmr);
static int		fxp_serial_ifmedia_upd(struct ifnet *ifp);
static void		fxp_serial_ifmedia_sts(struct ifnet *ifp,
			    struct ifmediareq *ifmr);
static volatile int	fxp_miibus_readreg(device_t dev, int phy, int reg);
static void		fxp_miibus_writereg(device_t dev, int phy, int reg,
			    int value);
static __inline void	fxp_lwcopy(volatile u_int32_t *src,
			    volatile u_int32_t *dst);
static __inline void 	fxp_scb_wait(struct fxp_softc *sc);
static __inline void	fxp_dma_wait(volatile u_int16_t *status,
			    struct fxp_softc *sc);

static device_method_t fxp_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		fxp_probe),
	DEVMETHOD(device_attach,	fxp_attach),
	DEVMETHOD(device_detach,	fxp_detach),
	DEVMETHOD(device_shutdown,	fxp_shutdown),
	DEVMETHOD(device_suspend,	fxp_suspend),
	DEVMETHOD(device_resume,	fxp_resume),

	/* MII interface */
	DEVMETHOD(miibus_readreg,	fxp_miibus_readreg),
	DEVMETHOD(miibus_writereg,	fxp_miibus_writereg),

	{ 0, 0 }
};

static driver_t fxp_driver = {
	"fxp",
	fxp_methods,
	sizeof(struct fxp_softc),
};

static devclass_t fxp_devclass;

DRIVER_MODULE(if_fxp, pci, fxp_driver, fxp_devclass, 0, 0);
DRIVER_MODULE(if_fxp, cardbus, fxp_driver, fxp_devclass, 0, 0);
DRIVER_MODULE(miibus, fxp, miibus_driver, miibus_devclass, 0, 0);

/*
 * Inline function to copy a 16-bit aligned 32-bit quantity.
 */
static __inline void
fxp_lwcopy(volatile u_int32_t *src, volatile u_int32_t *dst)
{
#ifdef __i386__
	*dst = *src;
#else
	volatile u_int16_t *a = (volatile u_int16_t *)src;
	volatile u_int16_t *b = (volatile u_int16_t *)dst;

	b[0] = a[0];
	b[1] = a[1];
#endif
}

/*
 * Wait for the previous command to be accepted (but not necessarily
 * completed).
 */
static __inline void
fxp_scb_wait(struct fxp_softc *sc)
{
	int i = 10000;

	while (CSR_READ_1(sc, FXP_CSR_SCB_COMMAND) && --i)
		DELAY(2);
	if (i == 0)
		device_printf(sc->dev, "SCB timeout\n");
}

static __inline void
fxp_dma_wait(volatile u_int16_t *status, struct fxp_softc *sc)
{
	int i = 10000;

	while (!(*status & FXP_CB_STATUS_C) && --i)
		DELAY(2);
	if (i == 0)
		device_printf(sc->dev, "DMA timeout\n");
}

/*
 * Return identification string if this is device is ours.
 */
static int
fxp_probe(device_t dev)
{
	u_int16_t devid;
	struct fxp_ident *ident;

	if (pci_get_vendor(dev) == FXP_VENDORID_INTEL) {
		devid = pci_get_device(dev);
		for (ident = fxp_ident_table; ident->name != NULL; ident++) {
			if (ident->devid == devid) {
				device_set_desc(dev, ident->name);
				return (0);
			}
		}
	}
	return (ENXIO);
}

static int
fxp_attach(device_t dev)
{
	int error = 0;
	struct fxp_softc *sc = device_get_softc(dev);
	struct ifnet *ifp;
	u_int32_t val;
	u_int16_t data;
	int i, rid, m1, m2, prefer_iomap;
	int s;

	bzero(sc, sizeof(*sc));
	sc->dev = dev;
	callout_handle_init(&sc->stat_ch);
	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), MTX_DEF | MTX_RECURSE);

	s = splimp();

	/*
	 * Enable bus mastering. Enable memory space too, in case
	 * BIOS/Prom forgot about it.
	 */
	val = pci_read_config(dev, PCIR_COMMAND, 2);
	val |= (PCIM_CMD_MEMEN|PCIM_CMD_BUSMASTEREN);
	pci_write_config(dev, PCIR_COMMAND, val, 2);
	val = pci_read_config(dev, PCIR_COMMAND, 2);

#if __FreeBSD_version >= 500000
	if (pci_get_powerstate(dev) != PCI_POWERSTATE_D0) {
		u_int32_t		iobase, membase, irq;

		/* Save important PCI config data. */
		iobase = pci_read_config(dev, FXP_PCI_IOBA, 4);
		membase = pci_read_config(dev, FXP_PCI_MMBA, 4);
		irq = pci_read_config(dev, PCIR_INTLINE, 4);

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

		pci_set_powerstate(dev, PCI_POWERSTATE_D0);

		/* Restore PCI config data. */
		pci_write_config(dev, FXP_PCI_IOBA, iobase, 4);
		pci_write_config(dev, FXP_PCI_MMBA, membase, 4);
		pci_write_config(dev, PCIR_INTLINE, irq, 4);
	}
#endif

	/*
	 * Figure out which we should try first - memory mapping or i/o mapping?
	 * We default to memory mapping. Then we accept an override from the
	 * command line. Then we check to see which one is enabled.
	 */
	m1 = PCIM_CMD_MEMEN;
	m2 = PCIM_CMD_PORTEN;
	prefer_iomap = 0;
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "prefer_iomap", &prefer_iomap) == 0 && prefer_iomap != 0) {
		m1 = PCIM_CMD_PORTEN;
		m2 = PCIM_CMD_MEMEN;
	}

	if (val & m1) {
		sc->rtp =
		    (m1 == PCIM_CMD_MEMEN)? SYS_RES_MEMORY : SYS_RES_IOPORT;
		sc->rgd = (m1 == PCIM_CMD_MEMEN)? FXP_PCI_MMBA : FXP_PCI_IOBA;
		sc->mem = bus_alloc_resource(dev, sc->rtp, &sc->rgd,
	                                     0, ~0, 1, RF_ACTIVE);
	}
	if (sc->mem == NULL && (val & m2)) {
		sc->rtp =
		    (m2 == PCIM_CMD_MEMEN)? SYS_RES_MEMORY : SYS_RES_IOPORT;
		sc->rgd = (m2 == PCIM_CMD_MEMEN)? FXP_PCI_MMBA : FXP_PCI_IOBA;
		sc->mem = bus_alloc_resource(dev, sc->rtp, &sc->rgd,
                                            0, ~0, 1, RF_ACTIVE);
	}

	if (!sc->mem) {
		device_printf(dev, "could not map device registers\n");
		error = ENXIO;
		goto fail;
        }
	if (bootverbose) {
		device_printf(dev, "using %s space register mapping\n",
		   sc->rtp == SYS_RES_MEMORY? "memory" : "I/O");
	}

	sc->sc_st = rman_get_bustag(sc->mem);
	sc->sc_sh = rman_get_bushandle(sc->mem);

	/*
	 * Allocate our interrupt.
	 */
	rid = 0;
	sc->irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
				 RF_SHAREABLE | RF_ACTIVE);
	if (sc->irq == NULL) {
		device_printf(dev, "could not map interrupt\n");
		error = ENXIO;
		goto fail;
	}

	error = bus_setup_intr(dev, sc->irq, INTR_TYPE_NET,
			       fxp_intr, sc, &sc->ih);
	if (error) {
		device_printf(dev, "could not setup irq\n");
		goto fail;
	}

	/*
	 * Reset to a stable state.
	 */
	CSR_WRITE_4(sc, FXP_CSR_PORT, FXP_PORT_SELECTIVE_RESET);
	DELAY(10);

	sc->cbl_base = malloc(sizeof(struct fxp_cb_tx) * FXP_NTXCB,
	    M_DEVBUF, M_NOWAIT | M_ZERO);
	if (sc->cbl_base == NULL)
		goto failmem;

	sc->fxp_stats = malloc(sizeof(struct fxp_stats), M_DEVBUF,
	    M_NOWAIT | M_ZERO);
	if (sc->fxp_stats == NULL)
		goto failmem;

	sc->mcsp = malloc(sizeof(struct fxp_cb_mcs), M_DEVBUF, M_NOWAIT);
	if (sc->mcsp == NULL)
		goto failmem;

	/*
	 * Pre-allocate our receive buffers.
	 */
	for (i = 0; i < FXP_NRFABUFS; i++) {
		if (fxp_add_rfabuf(sc, NULL) != 0) {
			goto failmem;
		}
	}

	/*
	 * Find out how large of an SEEPROM we have.
	 */
	fxp_autosize_eeprom(sc);

	/*
	 * Determine in whether we must use the 503 serial interface.
	 */
	fxp_read_eeprom(sc, &data, 6, 1);
	if ((data & FXP_PHY_DEVICE_MASK) != 0 &&
	    (data & FXP_PHY_SERIAL_ONLY))
		sc->flags &= FXP_FLAG_SERIAL_MEDIA;

	/*
	 * Read MAC address.
	 */
	fxp_read_eeprom(sc, (u_int16_t *)sc->arpcom.ac_enaddr, 0, 3);
	device_printf(dev, "Ethernet address %6D%s\n",
	    sc->arpcom.ac_enaddr, ":",
	    sc->flags & FXP_FLAG_SERIAL_MEDIA ? ", 10Mbps" : "");
	if (bootverbose) {
		device_printf(dev, "PCI IDs: %04x %04x %04x %04x\n",
		    pci_get_vendor(dev), pci_get_device(dev),
		    pci_get_subvendor(dev), pci_get_subdevice(dev));
	}

	/*
	 * If this is only a 10Mbps device, then there is no MII, and
	 * the PHY will use a serial interface instead.
	 *
	 * The Seeq 80c24 AutoDUPLEX(tm) Ethernet Interface Adapter
	 * doesn't have a programming interface of any sort.  The
	 * media is sensed automatically based on how the link partner
	 * is configured.  This is, in essence, manual configuration.
	 */
	if (sc->flags & FXP_FLAG_SERIAL_MEDIA) {
		ifmedia_init(&sc->sc_media, 0, fxp_serial_ifmedia_upd,
		    fxp_serial_ifmedia_sts);
		ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
		ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
	} else {
		if (mii_phy_probe(dev, &sc->miibus, fxp_ifmedia_upd,
		    fxp_ifmedia_sts)) {
	                device_printf(dev, "MII without any PHY!\n");
			error = ENXIO;
			goto fail;
		}
	}

	ifp = &sc->arpcom.ac_if;
	ifp->if_unit = device_get_unit(dev);
	ifp->if_name = "fxp";
	ifp->if_output = ether_output;
	ifp->if_baudrate = 100000000;
	ifp->if_init = fxp_init;
	ifp->if_softc = sc;
	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
	ifp->if_ioctl = fxp_ioctl;
	ifp->if_start = fxp_start;
	ifp->if_watchdog = fxp_watchdog;

	/*
	 * Attach the interface.
	 */
	ether_ifattach(ifp, ETHER_BPF_SUPPORTED);

	/*
	 * Let the system queue as many packets as we have available
	 * TX descriptors.
	 */
	ifp->if_snd.ifq_maxlen = FXP_NTXCB - 1;

	splx(s);
	return (0);

failmem:
	device_printf(dev, "Failed to malloc memory\n");
	error = ENOMEM;
fail:
	splx(s);
	fxp_release(sc);
	return (error);
}

/*
 * release all resources
 */
static void
fxp_release(struct fxp_softc *sc)
{

	if (sc->miibus) {
		bus_generic_detach(sc->dev);
		device_delete_child(sc->dev, sc->miibus);
	}

	if (sc->cbl_base)
		free(sc->cbl_base, M_DEVBUF);
	if (sc->fxp_stats)
		free(sc->fxp_stats, M_DEVBUF);
	if (sc->mcsp)
		free(sc->mcsp, M_DEVBUF);
	if (sc->rfa_headm)
		m_freem(sc->rfa_headm);

	if (sc->ih)
		bus_teardown_intr(sc->dev, sc->irq, sc->ih);
	if (sc->irq)
		bus_release_resource(sc->dev, SYS_RES_IRQ, 0, sc->irq);
	if (sc->mem)
		bus_release_resource(sc->dev, sc->rtp, sc->rgd, sc->mem);
	mtx_destroy(&sc->sc_mtx);
}

/*
 * Detach interface.
 */
static int
fxp_detach(device_t dev)
{
	struct fxp_softc *sc = device_get_softc(dev);
	int s;

	s = splimp();

	/*
	 * Stop DMA and drop transmit queue.
	 */
	fxp_stop(sc);

	/*
	 * Close down routes etc.
	 */
	ether_ifdetach(&sc->arpcom.ac_if, ETHER_BPF_SUPPORTED);

	/*
	 * Free all media structures.
	 */
	ifmedia_removeall(&sc->sc_media);

	splx(s);

	/* Release our allocated resources. */
	fxp_release(sc);

	return (0);
}

/*
 * Device shutdown routine. Called at system shutdown after sync. The
 * main purpose of this routine is to shut off receiver DMA so that
 * kernel memory doesn't get clobbered during warmboot.
 */
static int
fxp_shutdown(device_t dev)
{
	/*
	 * Make sure that DMA is disabled prior to reboot. Not doing
	 * do could allow DMA to corrupt kernel memory during the
	 * reboot before the driver initializes.
	 */
	fxp_stop((struct fxp_softc *) device_get_softc(dev));
	return (0);
}

/*
 * Device suspend routine.  Stop the interface and save some PCI
 * settings in case the BIOS doesn't restore them properly on
 * resume.
 */
static int
fxp_suspend(device_t dev)
{
	struct fxp_softc *sc = device_get_softc(dev);
	int i, s;

	s = splimp();

	fxp_stop(sc);

	for (i=0; i<5; i++)
		sc->saved_maps[i] = pci_read_config(dev, PCIR_MAPS + i*4, 4);
	sc->saved_biosaddr = pci_read_config(dev, PCIR_BIOS, 4);
	sc->saved_intline = pci_read_config(dev, PCIR_INTLINE, 1);
	sc->saved_cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
	sc->saved_lattimer = pci_read_config(dev, PCIR_LATTIMER, 1);

	sc->suspended = 1;

	splx(s);
	return (0);
}

/*
 * Device resume routine.  Restore some PCI settings in case the BIOS
 * doesn't, re-enable busmastering, and restart the interface if
 * appropriate.
 */
static int
fxp_resume(device_t dev)
{
	struct fxp_softc *sc = device_get_softc(dev);
	struct ifnet *ifp = &sc->sc_if;
	u_int16_t pci_command;
	int i, s;

	s = splimp();

	/* better way to do this? */
	for (i=0; i<5; i++)
		pci_write_config(dev, PCIR_MAPS + i*4, sc->saved_maps[i], 4);
	pci_write_config(dev, PCIR_BIOS, sc->saved_biosaddr, 4);
	pci_write_config(dev, PCIR_INTLINE, sc->saved_intline, 1);
	pci_write_config(dev, PCIR_CACHELNSZ, sc->saved_cachelnsz, 1);
	pci_write_config(dev, PCIR_LATTIMER, sc->saved_lattimer, 1);

	/* reenable busmastering */
	pci_command = pci_read_config(dev, PCIR_COMMAND, 2);
	pci_command |= (PCIM_CMD_MEMEN|PCIM_CMD_BUSMASTEREN);
	pci_write_config(dev, PCIR_COMMAND, pci_command, 2);

	CSR_WRITE_4(sc, FXP_CSR_PORT, FXP_PORT_SELECTIVE_RESET);
	DELAY(10);

	/* reinitialize interface if necessary */
	if (ifp->if_flags & IFF_UP)
		fxp_init(sc);

	sc->suspended = 0;

	splx(s);
	return (0);
}

/*
 * Read from the serial EEPROM. Basically, you manually shift in
 * the read opcode (one bit at a time) and then shift in the address,
 * and then you shift out the data (all of this one bit at a time).
 * The word size is 16 bits, so you have to provide the address for
 * every 16 bits of data.
 */
static u_int16_t
fxp_eeprom_getword(struct fxp_softc *sc, int offset, int autosize)
{
	u_int16_t reg, data;
	int x;

	CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, FXP_EEPROM_EECS);
	/*
	 * Shift in read opcode.
	 */
	for (x = 1 << 2; x; x >>= 1) {
		if (FXP_EEPROM_OPC_READ & x)
			reg = FXP_EEPROM_EECS | FXP_EEPROM_EEDI;
		else
			reg = FXP_EEPROM_EECS;
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg);
		DELAY(1);
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg | FXP_EEPROM_EESK);
		DELAY(1);
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg);
		DELAY(1);
	}
	/*
	 * Shift in address.
	 */
	data = 0;
	for (x = 1 << (sc->eeprom_size - 1); x; x >>= 1) {
		if (offset & x)
			reg = FXP_EEPROM_EECS | FXP_EEPROM_EEDI;
		else
			reg = FXP_EEPROM_EECS;
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg);
		DELAY(1);
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg | FXP_EEPROM_EESK);
		DELAY(1);
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg);
		DELAY(1);
		reg = CSR_READ_2(sc, FXP_CSR_EEPROMCONTROL) & FXP_EEPROM_EEDO;
		data++;
		if (autosize && reg == 0) {
			sc->eeprom_size = data;
			break;
		}
	}
	/*
	 * Shift out data.
	 */
	data = 0;
	reg = FXP_EEPROM_EECS;
	for (x = 1 << 15; x; x >>= 1) {
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg | FXP_EEPROM_EESK);
		DELAY(1);
		if (CSR_READ_2(sc, FXP_CSR_EEPROMCONTROL) & FXP_EEPROM_EEDO)
			data |= x;
		CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, reg);
		DELAY(1);
	}
	CSR_WRITE_2(sc, FXP_CSR_EEPROMCONTROL, 0);
	DELAY(1);

	return (data);
}

/*
 * From NetBSD:
 *
 * Figure out EEPROM size.
 *
 * 559's can have either 64-word or 256-word EEPROMs, the 558
 * datasheet only talks about 64-word EEPROMs, and the 557 datasheet
 * talks about the existance of 16 to 256 word EEPROMs.
 *
 * The only known sizes are 64 and 256, where the 256 version is used
 * by CardBus cards to store CIS information.
 *
 * The address is shifted in msb-to-lsb, and after the last
 * address-bit the EEPROM is supposed to output a `dummy zero' bit,
 * after which follows the actual data. We try to detect this zero, by
 * probing the data-out bit in the EEPROM control register just after
 * having shifted in a bit. If the bit is zero, we assume we've
 * shifted enough address bits. The data-out should be tri-state,
 * before this, which should translate to a logical one.
 *
 * Other ways to do this would be to try to read a register with known
 * contents with a varying number of address bits, but no such
 * register seem to be available. The high bits of register 10 are 01
 * on the 558 and 559, but apparently not on the 557.
 *
 * The Linux driver computes a checksum on the EEPROM data, but the
 * value of this checksum is not very well documented.
 */
static void
fxp_autosize_eeprom(struct fxp_softc *sc)
{

	/* guess maximum size of 256 words */
	sc->eeprom_size = 8;

	/* autosize */
	(void) fxp_eeprom_getword(sc, 0, 1);
}

static void
fxp_read_eeprom(struct fxp_softc *sc, u_short *data, int offset, int words)
{
	int i;

	for (i = 0; i < words; i++)
		data[i] = fxp_eeprom_getword(sc, offset + i, 0);
}

/*
 * Start packet transmission on the interface.
 */
static void
fxp_start(struct ifnet *ifp)
{
	struct fxp_softc *sc = ifp->if_softc;
	struct fxp_cb_tx *txp;

	/*
	 * See if we need to suspend xmit until the multicast filter
	 * has been reprogrammed (which can only be done at the head
	 * of the command chain).
	 */
	if (sc->need_mcsetup) {
		return;
	}

	txp = NULL;

	/*
	 * We're finished if there is nothing more to add to the list or if
	 * we're all filled up with buffers to transmit.
	 * NOTE: One TxCB is reserved to guarantee that fxp_mc_setup() can add
	 *       a NOP command when needed.
	 */
	while (ifp->if_snd.ifq_head != NULL && sc->tx_queued < FXP_NTXCB - 1) {
		struct mbuf *m, *mb_head;
		int segment;

		/*
		 * Grab a packet to transmit.
		 */
		IF_DEQUEUE(&ifp->if_snd, mb_head);

		/*
		 * Get pointer to next available tx desc.
		 */
		txp = sc->cbl_last->next;

		/*
		 * Go through each of the mbufs in the chain and initialize
		 * the transmit buffer descriptors with the physical address
		 * and size of the mbuf.
		 */
tbdinit:
		for (m = mb_head, segment = 0; m != NULL; m = m->m_next) {
			if (m->m_len != 0) {
				if (segment == FXP_NTXSEG)
					break;
				txp->tbd[segment].tb_addr =
				    vtophys(mtod(m, vm_offset_t));
				txp->tbd[segment].tb_size = m->m_len;
				segment++;
			}
		}
		if (m != NULL) {
			struct mbuf *mn;

			/*
			 * We ran out of segments. We have to recopy this mbuf
			 * chain first. Bail out if we can't get the new buffers.
			 */
			MGETHDR(mn, M_DONTWAIT, MT_DATA);
			if (mn == NULL) {
				m_freem(mb_head);
				break;
			}
			if (mb_head->m_pkthdr.len > MHLEN) {
				MCLGET(mn, M_DONTWAIT);
				if ((mn->m_flags & M_EXT) == 0) {
					m_freem(mn);
					m_freem(mb_head);
					break;
				}
			}
			m_copydata(mb_head, 0, mb_head->m_pkthdr.len,
			    mtod(mn, caddr_t));
			mn->m_pkthdr.len = mn->m_len = mb_head->m_pkthdr.len;
			m_freem(mb_head);
			mb_head = mn;
			goto tbdinit;
		}

		txp->tbd_number = segment;
		txp->mb_head = mb_head;
		txp->cb_status = 0;
		if (sc->tx_queued != FXP_CXINT_THRESH - 1) {
			txp->cb_command =
			    FXP_CB_COMMAND_XMIT | FXP_CB_COMMAND_SF | FXP_CB_COMMAND_S;
		} else {
			txp->cb_command =
			    FXP_CB_COMMAND_XMIT | FXP_CB_COMMAND_SF | FXP_CB_COMMAND_S | FXP_CB_COMMAND_I;
			/*
			 * Set a 5 second timer just in case we don't hear from the
			 * card again.
			 */
			ifp->if_timer = 5;
		}
		txp->tx_threshold = tx_threshold;

		/*
		 * Advance the end of list forward.
		 */

#ifdef __alpha__
		/*
		 * On platforms which can't access memory in 16-bit
		 * granularities, we must prevent the card from DMA'ing
		 * up the status while we update the command field.
		 * This could cause us to overwrite the completion status.
		 */
		atomic_clear_short(&sc->cbl_last->cb_command,
		    FXP_CB_COMMAND_S);
#else
		sc->cbl_last->cb_command &= ~FXP_CB_COMMAND_S;
#endif /*__alpha__*/
		sc->cbl_last = txp;

		/*
		 * Advance the beginning of the list forward if there are
		 * no other packets queued (when nothing is queued, cbl_first
		 * sits on the last TxCB that was sent out).
		 */
		if (sc->tx_queued == 0)
			sc->cbl_first = txp;

		sc->tx_queued++;

		/*
		 * Pass packet to bpf if there is a listener.
		 */
		if (ifp->if_bpf)
			bpf_mtap(ifp, mb_head);
	}

	/*
	 * We're finished. If we added to the list, issue a RESUME to get DMA
	 * going again if suspended.
	 */
	if (txp != NULL) {
		fxp_scb_wait(sc);
		CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_RESUME);
	}
}

/*
 * Process interface interrupts.
 */
static void
fxp_intr(void *xsc)
{
	struct fxp_softc *sc = xsc;
	struct ifnet *ifp = &sc->sc_if;
	u_int8_t statack;


	if (sc->suspended) {
		return;
	}

	while ((statack = CSR_READ_1(sc, FXP_CSR_SCB_STATACK)) != 0) {
		/*
		 * First ACK all the interrupts in this pass.
		 */
		CSR_WRITE_1(sc, FXP_CSR_SCB_STATACK, statack);

		/*
		 * Free any finished transmit mbuf chains.
		 *
		 * Handle the CNA event likt a CXTNO event. It used to
		 * be that this event (control unit not ready) was not
		 * encountered, but it is now with the SMPng modifications.
		 * The exact sequence of events that occur when the interface
		 * is brought up are different now, and if this event
		 * goes unhandled, the configuration/rxfilter setup sequence
		 * can stall for several seconds. The result is that no
		 * packets go out onto the wire for about 5 to 10 seconds
		 * after the interface is ifconfig'ed for the first time.
		 */
		if (statack & (FXP_SCB_STATACK_CXTNO | FXP_SCB_STATACK_CNA)) {
			struct fxp_cb_tx *txp;

			for (txp = sc->cbl_first; sc->tx_queued &&
			    (txp->cb_status & FXP_CB_STATUS_C) != 0;
			    txp = txp->next) {
				if (txp->mb_head != NULL) {
					m_freem(txp->mb_head);
					txp->mb_head = NULL;
				}
				sc->tx_queued--;
			}
			sc->cbl_first = txp;
			ifp->if_timer = 0;
			if (sc->tx_queued == 0) {
				if (sc->need_mcsetup)
					fxp_mc_setup(sc);
			}
			/*
			 * Try to start more packets transmitting.
			 */
			if (ifp->if_snd.ifq_head != NULL)
				fxp_start(ifp);
		}
		/*
		 * Process receiver interrupts. If a no-resource (RNR)
		 * condition exists, get whatever packets we can and
		 * re-start the receiver.
		 */
		if (statack & (FXP_SCB_STATACK_FR | FXP_SCB_STATACK_RNR)) {
			struct mbuf *m;
			struct fxp_rfa *rfa;
rcvloop:
			m = sc->rfa_headm;
			rfa = (struct fxp_rfa *)(m->m_ext.ext_buf +
			    RFA_ALIGNMENT_FUDGE);

			if (rfa->rfa_status & FXP_RFA_STATUS_C) {
				/*
				 * Remove first packet from the chain.
				 */
				sc->rfa_headm = m->m_next;
				m->m_next = NULL;

				/*
				 * Add a new buffer to the receive chain.
				 * If this fails, the old buffer is recycled
				 * instead.
				 */
				if (fxp_add_rfabuf(sc, m) == 0) {
					struct ether_header *eh;
					int total_len;

					total_len = rfa->actual_size &
					    (MCLBYTES - 1);
					if (total_len <
					    sizeof(struct ether_header)) {
						m_freem(m);
						goto rcvloop;
					}
					m->m_pkthdr.rcvif = ifp;
					m->m_pkthdr.len = m->m_len = total_len;
					eh = mtod(m, struct ether_header *);
					m->m_data +=
					    sizeof(struct ether_header);
					m->m_len -=
					    sizeof(struct ether_header);
					m->m_pkthdr.len = m->m_len;
					ether_input(ifp, eh, m);
				}
				goto rcvloop;
			}
			if (statack & FXP_SCB_STATACK_RNR) {
				fxp_scb_wait(sc);
				CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL,
				    vtophys(sc->rfa_headm->m_ext.ext_buf) +
					RFA_ALIGNMENT_FUDGE);
				CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND,
				    FXP_SCB_COMMAND_RU_START);
			}
		}
	}
}

/*
 * Update packet in/out/collision statistics. The i82557 doesn't
 * allow you to access these counters without doing a fairly
 * expensive DMA to get _all_ of the statistics it maintains, so
 * we do this operation here only once per second. The statistics
 * counters in the kernel are updated from the previous dump-stats
 * DMA and then a new dump-stats DMA is started. The on-chip
 * counters are zeroed when the DMA completes. If we can't start
 * the DMA immediately, we don't wait - we just prepare to read
 * them again next time.
 */
static void
fxp_tick(void *xsc)
{
	struct fxp_softc *sc = xsc;
	struct ifnet *ifp = &sc->sc_if;
	struct fxp_stats *sp = sc->fxp_stats;
	struct fxp_cb_tx *txp;
	int s;

	ifp->if_opackets += sp->tx_good;
	ifp->if_collisions += sp->tx_total_collisions;
	if (sp->rx_good) {
		ifp->if_ipackets += sp->rx_good;
		sc->rx_idle_secs = 0;
	} else {
		/*
		 * Receiver's been idle for another second.
		 */
		sc->rx_idle_secs++;
	}
	ifp->if_ierrors +=
	    sp->rx_crc_errors +
	    sp->rx_alignment_errors +
	    sp->rx_rnr_errors +
	    sp->rx_overrun_errors;
	/*
	 * If any transmit underruns occured, bump up the transmit
	 * threshold by another 512 bytes (64 * 8).
	 */
	if (sp->tx_underruns) {
		ifp->if_oerrors += sp->tx_underruns;
		if (tx_threshold < 192)
			tx_threshold += 64;
	}
	s = splimp();
	/*
	 * Release any xmit buffers that have completed DMA. This isn't
	 * strictly necessary to do here, but it's advantagous for mbufs
	 * with external storage to be released in a timely manner rather
	 * than being defered for a potentially long time. This limits
	 * the delay to a maximum of one second.
	 */
	for (txp = sc->cbl_first; sc->tx_queued &&
	    (txp->cb_status & FXP_CB_STATUS_C) != 0;
	    txp = txp->next) {
		if (txp->mb_head != NULL) {
			m_freem(txp->mb_head);
			txp->mb_head = NULL;
		}
		sc->tx_queued--;
	}
	sc->cbl_first = txp;
	/*
	 * If we haven't received any packets in FXP_MAC_RX_IDLE seconds,
	 * then assume the receiver has locked up and attempt to clear
	 * the condition by reprogramming the multicast filter. This is
	 * a work-around for a bug in the 82557 where the receiver locks
	 * up if it gets certain types of garbage in the syncronization
	 * bits prior to the packet header. This bug is supposed to only
	 * occur in 10Mbps mode, but has been seen to occur in 100Mbps
	 * mode as well (perhaps due to a 10/100 speed transition).
	 */
	if (sc->rx_idle_secs > FXP_MAX_RX_IDLE) {
		sc->rx_idle_secs = 0;
		fxp_mc_setup(sc);
	}
	/*
	 * If there is no pending command, start another stats
	 * dump. Otherwise punt for now.
	 */
	if (CSR_READ_1(sc, FXP_CSR_SCB_COMMAND) == 0) {
		/*
		 * Start another stats dump.
		 */
		CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND,
		    FXP_SCB_COMMAND_CU_DUMPRESET);
	} else {
		/*
		 * A previous command is still waiting to be accepted.
		 * Just zero our copy of the stats and wait for the
		 * next timer event to update them.
		 */
		sp->tx_good = 0;
		sp->tx_underruns = 0;
		sp->tx_total_collisions = 0;

		sp->rx_good = 0;
		sp->rx_crc_errors = 0;
		sp->rx_alignment_errors = 0;
		sp->rx_rnr_errors = 0;
		sp->rx_overrun_errors = 0;
	}

	if (sc->miibus != NULL)
		mii_tick(device_get_softc(sc->miibus));

	/*
	 * Schedule another timeout one second from now.
	 */
	sc->stat_ch = timeout(fxp_tick, sc, hz);
}

/*
 * Stop the interface. Cancels the statistics updater and resets
 * the interface.
 */
static void
fxp_stop(struct fxp_softc *sc)
{
	struct ifnet *ifp = &sc->sc_if;
	struct fxp_cb_tx *txp;
	int i;


	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
	ifp->if_timer = 0;

	/*
	 * Cancel stats updater.
	 */
	untimeout(fxp_tick, sc, sc->stat_ch);

	/*
	 * Issue software reset
	 */
	CSR_WRITE_4(sc, FXP_CSR_PORT, FXP_PORT_SELECTIVE_RESET);
	DELAY(10);

	/*
	 * Release any xmit buffers.
	 */
	txp = sc->cbl_base;
	if (txp != NULL) {
		for (i = 0; i < FXP_NTXCB; i++) {
			if (txp[i].mb_head != NULL) {
				m_freem(txp[i].mb_head);
				txp[i].mb_head = NULL;
			}
		}
	}
	sc->tx_queued = 0;

	/*
	 * Free all the receive buffers then reallocate/reinitialize
	 */
	if (sc->rfa_headm != NULL)
		m_freem(sc->rfa_headm);
	sc->rfa_headm = NULL;
	sc->rfa_tailm = NULL;
	for (i = 0; i < FXP_NRFABUFS; i++) {
		if (fxp_add_rfabuf(sc, NULL) != 0) {
			/*
			 * This "can't happen" - we're at splimp()
			 * and we just freed all the buffers we need
			 * above.
			 */
			panic("fxp_stop: no buffers!");
		}
	}
}

/*
 * Watchdog/transmission transmit timeout handler. Called when a
 * transmission is started on the interface, but no interrupt is
 * received before the timeout. This usually indicates that the
 * card has wedged for some reason.
 */
static void
fxp_watchdog(struct ifnet *ifp)
{
	struct fxp_softc *sc = ifp->if_softc;

	device_printf(sc->dev, "device timeout\n");
	ifp->if_oerrors++;

	fxp_init(sc);
}

static void
fxp_init(void *xsc)
{
	struct fxp_softc *sc = xsc;
	struct ifnet *ifp = &sc->sc_if;
	struct fxp_cb_config *cbp;
	struct fxp_cb_ias *cb_ias;
	struct fxp_cb_tx *txp;
	int i, prm, s;

	s = splimp();
	/*
	 * Cancel any pending I/O
	 */
	fxp_stop(sc);

	prm = (ifp->if_flags & IFF_PROMISC) ? 1 : 0;

	/*
	 * Initialize base of CBL and RFA memory. Loading with zero
	 * sets it up for regular linear addressing.
	 */
	CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL, 0);
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_BASE);

	fxp_scb_wait(sc);
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_RU_BASE);

	/*
	 * Initialize base of dump-stats buffer.
	 */
	fxp_scb_wait(sc);
	CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL, vtophys(sc->fxp_stats));
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_DUMP_ADR);

	/*
	 * We temporarily use memory that contains the TxCB list to
	 * construct the config CB. The TxCB list memory is rebuilt
	 * later.
	 */
	cbp = (struct fxp_cb_config *) sc->cbl_base;

	/*
	 * This bcopy is kind of disgusting, but there are a bunch of must be
	 * zero and must be one bits in this structure and this is the easiest
	 * way to initialize them all to proper values.
	 */
	bcopy(fxp_cb_config_template,
		(void *)(uintptr_t)(volatile void *)&cbp->cb_status,
		sizeof(fxp_cb_config_template));

	cbp->cb_status =	0;
	cbp->cb_command =	FXP_CB_COMMAND_CONFIG | FXP_CB_COMMAND_EL;
	cbp->link_addr =	-1;	/* (no) next command */
	cbp->byte_count =	22;	/* (22) bytes to config */
	cbp->rx_fifo_limit =	8;	/* rx fifo threshold (32 bytes) */
	cbp->tx_fifo_limit =	0;	/* tx fifo threshold (0 bytes) */
	cbp->adaptive_ifs =	0;	/* (no) adaptive interframe spacing */
	cbp->mwi_enable =	sc->flags & FXP_FLAG_MWI_ENABLE ? 1 : 0;
	cbp->type_enable =	0;	/* actually reserved */
	cbp->read_align_en =	sc->flags & FXP_FLAG_READ_ALIGN ? 1 : 0;
	cbp->end_wr_on_cl =	sc->flags & FXP_FLAG_WRITE_ALIGN ? 1 : 0;
	cbp->rx_dma_bytecount =	0;	/* (no) rx DMA max */
	cbp->tx_dma_bytecount =	0;	/* (no) tx DMA max */
	cbp->dma_mbce =		0;	/* (disable) dma max counters */
	cbp->late_scb =		0;	/* (don't) defer SCB update */
	cbp->direct_dma_dis =	1;	/* disable direct rcv dma mode */
	cbp->tno_int_or_tco_en =0;	/* (disable) tx not okay interrupt */
	cbp->ci_int =		1;	/* interrupt on CU idle */
	cbp->ext_txcb_dis = 	sc->flags & FXP_FLAG_EXT_TXCB ? 0 : 1;
	cbp->ext_stats_dis = 	1;	/* disable extended counters */
	cbp->keep_overrun_rx = 	0;	/* don't pass overrun frames to host */
	cbp->save_bf =		prm;	/* save bad frames */
	cbp->disc_short_rx =	!prm;	/* discard short packets */
	cbp->underrun_retry =	1;	/* retry mode (once) on DMA underrun */
	cbp->two_frames =	0;	/* do not limit FIFO to 2 frames */
	cbp->dyn_tbd =		0;	/* (no) dynamic TBD mode */
	cbp->mediatype =	sc->flags & FXP_FLAG_SERIAL_MEDIA ? 0 : 1;
	cbp->csma_dis =		0;	/* (don't) disable link */
	cbp->tcp_udp_cksum =	0;	/* (don't) enable checksum */
	cbp->vlan_tco =		0;	/* (don't) enable vlan wakeup */
	cbp->link_wake_en =	0;	/* (don't) assert PME# on link change */
	cbp->arp_wake_en =	0;	/* (don't) assert PME# on arp */
	cbp->mc_wake_en =	0;	/* (don't) enable PME# on mcmatch */
	cbp->nsai =		1;	/* (don't) disable source addr insert */
	cbp->preamble_length =	2;	/* (7 byte) preamble */
	cbp->loopback =		0;	/* (don't) loopback */
	cbp->linear_priority =	0;	/* (normal CSMA/CD operation) */
	cbp->linear_pri_mode =	0;	/* (wait after xmit only) */
	cbp->interfrm_spacing =	6;	/* (96 bits of) interframe spacing */
	cbp->promiscuous =	prm;	/* promiscuous mode */
	cbp->bcast_disable =	0;	/* (don't) disable broadcasts */
	cbp->wait_after_win =	0;	/* (don't) enable modified backoff alg*/
	cbp->ignore_ul =	0;	/* consider U/L bit in IA matching */
	cbp->crc16_en =		0;	/* (don't) enable crc-16 algorithm */
	cbp->crscdt =		sc->flags & FXP_FLAG_SERIAL_MEDIA ? 1 : 0;

	/*
	 * we may want to move all FC stuff to a separate section.
	 * the values here are 82557 compatible.
	 */
	cbp->fc_delay_lsb =	0;
	cbp->fc_delay_msb =	0x40;
	cbp->pri_fc_thresh =	0x03;
	cbp->tx_fc_dis =	0;	/* (don't) disable transmit FC */
	cbp->rx_fc_restop =	0;	/* (don't) enable FC stop frame */
	cbp->rx_fc_restart =	0;	/* (don't) enable FC start frame */
	cbp->fc_filter =	0;	/* (do) pass FC frames to host */
	cbp->pri_fc_loc =	1;	/* location of priority in FC frame */

	cbp->stripping =	!prm;	/* truncate rx packet to byte count */
	cbp->padding =		1;	/* (do) pad short tx packets */
	cbp->rcv_crc_xfer =	0;	/* (don't) xfer CRC to host */
	cbp->long_rx_en =	sc->flags & FXP_FLAG_LONG_PKT_EN ? 1 : 0;
	cbp->ia_wake_en =	0;	/* (don't) wake up on address match */
	cbp->magic_pkt_dis =	0;	/* (don't) disable magic packet */
					/* must set wake_en in PMCSR also */
	cbp->force_fdx =	0;	/* (don't) force full duplex */
	cbp->fdx_pin_en =	1;	/* (enable) FDX# pin */
	cbp->multi_ia =		0;	/* (don't) accept multiple IAs */
	cbp->mc_all =		sc->flags & FXP_FLAG_ALL_MCAST ? 1 : 0;

	/*
	 * Start the config command/DMA.
	 */
	fxp_scb_wait(sc);
	CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL, vtophys(&cbp->cb_status));
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_START);
	/* ...and wait for it to complete. */
	fxp_dma_wait(&cbp->cb_status, sc);

	/*
	 * Now initialize the station address. Temporarily use the TxCB
	 * memory area like we did above for the config CB.
	 */
	cb_ias = (struct fxp_cb_ias *) sc->cbl_base;
	cb_ias->cb_status = 0;
	cb_ias->cb_command = FXP_CB_COMMAND_IAS | FXP_CB_COMMAND_EL;
	cb_ias->link_addr = -1;
	bcopy(sc->arpcom.ac_enaddr,
	    (void *)(uintptr_t)(volatile void *)cb_ias->macaddr,
	    sizeof(sc->arpcom.ac_enaddr));

	/*
	 * Start the IAS (Individual Address Setup) command/DMA.
	 */
	fxp_scb_wait(sc);
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_START);
	/* ...and wait for it to complete. */
	fxp_dma_wait(&cb_ias->cb_status, sc);

	/*
	 * Initialize transmit control block (TxCB) list.
	 */

	txp = sc->cbl_base;
	bzero(txp, sizeof(struct fxp_cb_tx) * FXP_NTXCB);
	for (i = 0; i < FXP_NTXCB; i++) {
		txp[i].cb_status = FXP_CB_STATUS_C | FXP_CB_STATUS_OK;
		txp[i].cb_command = FXP_CB_COMMAND_NOP;
		txp[i].link_addr = vtophys(&txp[(i + 1) & FXP_TXCB_MASK].cb_status);
		txp[i].tbd_array_addr = vtophys(&txp[i].tbd[0]);
		txp[i].next = &txp[(i + 1) & FXP_TXCB_MASK];
	}
	/*
	 * Set the suspend flag on the first TxCB and start the control
	 * unit. It will execute the NOP and then suspend.
	 */
	txp->cb_command = FXP_CB_COMMAND_NOP | FXP_CB_COMMAND_S;
	sc->cbl_first = sc->cbl_last = txp;
	sc->tx_queued = 1;

	fxp_scb_wait(sc);
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_START);

	/*
	 * Initialize receiver buffer area - RFA.
	 */
	fxp_scb_wait(sc);
	CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL,
	    vtophys(sc->rfa_headm->m_ext.ext_buf) + RFA_ALIGNMENT_FUDGE);
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_RU_START);

	/*
	 * Set current media.
	 */
	if (sc->miibus != NULL)
		mii_mediachg(device_get_softc(sc->miibus));

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

	/*
	 * Start stats updater.
	 */
	sc->stat_ch = timeout(fxp_tick, sc, hz);
}

static int
fxp_serial_ifmedia_upd(struct ifnet *ifp)
{

	return (0);
}

static void
fxp_serial_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{

	ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
}

/*
 * Change media according to request.
 */
static int
fxp_ifmedia_upd(struct ifnet *ifp)
{
	struct fxp_softc *sc = ifp->if_softc;
	struct mii_data *mii;

	mii = device_get_softc(sc->miibus);
	mii_mediachg(mii);
	return (0);
}

/*
 * Notify the world which media we're using.
 */
static void
fxp_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
	struct fxp_softc *sc = ifp->if_softc;
	struct mii_data *mii;

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

/*
 * Add a buffer to the end of the RFA buffer list.
 * Return 0 if successful, 1 for failure. A failure results in
 * adding the 'oldm' (if non-NULL) on to the end of the list -
 * tossing out its old contents and recycling it.
 * The RFA struct is stuck at the beginning of mbuf cluster and the
 * data pointer is fixed up to point just past it.
 */
static int
fxp_add_rfabuf(struct fxp_softc *sc, struct mbuf *oldm)
{
	u_int32_t v;
	struct mbuf *m;
	struct fxp_rfa *rfa, *p_rfa;

	MGETHDR(m, M_DONTWAIT, MT_DATA);
	if (m != NULL) {
		MCLGET(m, M_DONTWAIT);
		if ((m->m_flags & M_EXT) == 0) {
			m_freem(m);
			if (oldm == NULL)
				return 1;
			m = oldm;
			m->m_data = m->m_ext.ext_buf;
		}
	} else {
		if (oldm == NULL)
			return 1;
		m = oldm;
		m->m_data = m->m_ext.ext_buf;
	}

	/*
	 * Move the data pointer up so that the incoming data packet
	 * will be 32-bit aligned.
	 */
	m->m_data += RFA_ALIGNMENT_FUDGE;

	/*
	 * Get a pointer to the base of the mbuf cluster and move
	 * data start past it.
	 */
	rfa = mtod(m, struct fxp_rfa *);
	m->m_data += sizeof(struct fxp_rfa);
	rfa->size = (u_int16_t)(MCLBYTES - sizeof(struct fxp_rfa) - RFA_ALIGNMENT_FUDGE);

	/*
	 * Initialize the rest of the RFA.  Note that since the RFA
	 * is misaligned, we cannot store values directly.  Instead,
	 * we use an optimized, inline copy.
	 */

	rfa->rfa_status = 0;
	rfa->rfa_control = FXP_RFA_CONTROL_EL;
	rfa->actual_size = 0;

	v = -1;
	fxp_lwcopy(&v, (volatile u_int32_t *) rfa->link_addr);
	fxp_lwcopy(&v, (volatile u_int32_t *) rfa->rbd_addr);

	/*
	 * If there are other buffers already on the list, attach this
	 * one to the end by fixing up the tail to point to this one.
	 */
	if (sc->rfa_headm != NULL) {
		p_rfa = (struct fxp_rfa *) (sc->rfa_tailm->m_ext.ext_buf +
		    RFA_ALIGNMENT_FUDGE);
		sc->rfa_tailm->m_next = m;
		v = vtophys(rfa);
		fxp_lwcopy(&v, (volatile u_int32_t *) p_rfa->link_addr);
		p_rfa->rfa_control = 0;
	} else {
		sc->rfa_headm = m;
	}
	sc->rfa_tailm = m;

	return (m == oldm);
}

static volatile int
fxp_miibus_readreg(device_t dev, int phy, int reg)
{
	struct fxp_softc *sc = device_get_softc(dev);
	int count = 10000;
	int value;

	CSR_WRITE_4(sc, FXP_CSR_MDICONTROL,
	    (FXP_MDI_READ << 26) | (reg << 16) | (phy << 21));

	while (((value = CSR_READ_4(sc, FXP_CSR_MDICONTROL)) & 0x10000000) == 0
	    && count--)
		DELAY(10);

	if (count <= 0)
		device_printf(dev, "fxp_miibus_readreg: timed out\n");

	return (value & 0xffff);
}

static void
fxp_miibus_writereg(device_t dev, int phy, int reg, int value)
{
	struct fxp_softc *sc = device_get_softc(dev);
	int count = 10000;

	CSR_WRITE_4(sc, FXP_CSR_MDICONTROL,
	    (FXP_MDI_WRITE << 26) | (reg << 16) | (phy << 21) |
	    (value & 0xffff));

	while ((CSR_READ_4(sc, FXP_CSR_MDICONTROL) & 0x10000000) == 0 &&
	    count--)
		DELAY(10);

	if (count <= 0)
		device_printf(dev, "fxp_miibus_writereg: timed out\n");
}

static int
fxp_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
{
	struct fxp_softc *sc = ifp->if_softc;
	struct ifreq *ifr = (struct ifreq *)data;
        struct mii_data *mii;
	int s, error = 0;

	s = splimp();

	switch (command) {
	case SIOCSIFADDR:
	case SIOCGIFADDR:
	case SIOCSIFMTU:
		error = ether_ioctl(ifp, command, data);
		break;

	case SIOCSIFFLAGS:
		if (ifp->if_flags & IFF_ALLMULTI)
			sc->flags |= FXP_FLAG_ALL_MCAST;
		else
			sc->flags &= ~FXP_FLAG_ALL_MCAST;

		/*
		 * If interface is marked up and not running, then start it.
		 * If it is marked down and running, stop it.
		 * XXX If it's up then re-initialize it. This is so flags
		 * such as IFF_PROMISC are handled.
		 */
		if (ifp->if_flags & IFF_UP) {
			fxp_init(sc);
		} else {
			if (ifp->if_flags & IFF_RUNNING)
				fxp_stop(sc);
		}
		break;

	case SIOCADDMULTI:
	case SIOCDELMULTI:
		if (ifp->if_flags & IFF_ALLMULTI)
			sc->flags |= FXP_FLAG_ALL_MCAST;
		else
			sc->flags &= ~FXP_FLAG_ALL_MCAST;
		/*
		 * Multicast list has changed; set the hardware filter
		 * accordingly.
		 */
		if ((sc->flags & FXP_FLAG_ALL_MCAST) == 0)
			fxp_mc_setup(sc);
		/*
		 * fxp_mc_setup() can set FXP_FLAG_ALL_MCAST, so check it
		 * again rather than else {}.
		 */
		if (sc->flags & FXP_FLAG_ALL_MCAST)
			fxp_init(sc);
		error = 0;
		break;

	case SIOCSIFMEDIA:
	case SIOCGIFMEDIA:
		if (sc->miibus != NULL) {
			mii = device_get_softc(sc->miibus);
                        error = ifmedia_ioctl(ifp, ifr,
                            &mii->mii_media, command);
		} else {
                        error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, command);
		}
		break;

	default:
		error = EINVAL;
	}
	splx(s);
	return (error);
}

/*
 * Program the multicast filter.
 *
 * We have an artificial restriction that the multicast setup command
 * must be the first command in the chain, so we take steps to ensure
 * this. By requiring this, it allows us to keep up the performance of
 * the pre-initialized command ring (esp. link pointers) by not actually
 * inserting the mcsetup command in the ring - i.e. its link pointer
 * points to the TxCB ring, but the mcsetup descriptor itself is not part
 * of it. We then can do 'CU_START' on the mcsetup descriptor and have it
 * lead into the regular TxCB ring when it completes.
 *
 * This function must be called at splimp.
 */
static void
fxp_mc_setup(struct fxp_softc *sc)
{
	struct fxp_cb_mcs *mcsp = sc->mcsp;
	struct ifnet *ifp = &sc->sc_if;
	struct ifmultiaddr *ifma;
	int nmcasts;
	int count;

	/*
	 * If there are queued commands, we must wait until they are all
	 * completed. If we are already waiting, then add a NOP command
	 * with interrupt option so that we're notified when all commands
	 * have been completed - fxp_start() ensures that no additional
	 * TX commands will be added when need_mcsetup is true.
	 */
	if (sc->tx_queued) {
		struct fxp_cb_tx *txp;

		/*
		 * need_mcsetup will be true if we are already waiting for the
		 * NOP command to be completed (see below). In this case, bail.
		 */
		if (sc->need_mcsetup)
			return;
		sc->need_mcsetup = 1;

		/*
		 * Add a NOP command with interrupt so that we are notified when all
		 * TX commands have been processed.
		 */
		txp = sc->cbl_last->next;
		txp->mb_head = NULL;
		txp->cb_status = 0;
		txp->cb_command = FXP_CB_COMMAND_NOP | FXP_CB_COMMAND_S | FXP_CB_COMMAND_I;
		/*
		 * Advance the end of list forward.
		 */
		sc->cbl_last->cb_command &= ~FXP_CB_COMMAND_S;
		sc->cbl_last = txp;
		sc->tx_queued++;
		/*
		 * Issue a resume in case the CU has just suspended.
		 */
		fxp_scb_wait(sc);
		CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_RESUME);
		/*
		 * Set a 5 second timer just in case we don't hear from the
		 * card again.
		 */
		ifp->if_timer = 5;

		return;
	}
	sc->need_mcsetup = 0;

	/*
	 * Initialize multicast setup descriptor.
	 */
	mcsp->next = sc->cbl_base;
	mcsp->mb_head = NULL;
	mcsp->cb_status = 0;
	mcsp->cb_command = FXP_CB_COMMAND_MCAS | FXP_CB_COMMAND_S | FXP_CB_COMMAND_I;
	mcsp->link_addr = vtophys(&sc->cbl_base->cb_status);

	nmcasts = 0;
	if ((sc->flags & FXP_FLAG_ALL_MCAST) == 0) {
#if __FreeBSD_version < 500000
		LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
#else
		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
#endif
			if (ifma->ifma_addr->sa_family != AF_LINK)
				continue;
			if (nmcasts >= MAXMCADDR) {
				sc->flags |= FXP_FLAG_ALL_MCAST;
				nmcasts = 0;
				break;
			}
			bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
			    (void *)(uintptr_t)(volatile void *)
				&sc->mcsp->mc_addr[nmcasts][0], 6);
			nmcasts++;
		}
	}
	mcsp->mc_cnt = nmcasts * 6;
	sc->cbl_first = sc->cbl_last = (struct fxp_cb_tx *) mcsp;
	sc->tx_queued = 1;

	/*
	 * Wait until command unit is not active. This should never
	 * be the case when nothing is queued, but make sure anyway.
	 */
	count = 100;
	while ((CSR_READ_1(sc, FXP_CSR_SCB_RUSCUS) >> 6) ==
	    FXP_SCB_CUS_ACTIVE && --count)
		DELAY(10);
	if (count == 0) {
		device_printf(sc->dev, "command queue timeout\n");
		return;
	}

	/*
	 * Start the multicast setup command.
	 */
	fxp_scb_wait(sc);
	CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL, vtophys(&mcsp->cb_status));
	CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_SCB_COMMAND_CU_START);

	ifp->if_timer = 2;
	return;
}