This commit was generated by cvs2svn to compensate for changes in r146609,

[FreeBSD/FreeBSD.git] / sys / dev / re / if_re.c

/*-
 * Copyright (c) 1997, 1998-2003
 *      Bill Paul <wpaul@windriver.com>.  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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * RealTek 8139C+/8169/8169S/8110S PCI NIC driver
 *
 * Written by Bill Paul <wpaul@windriver.com>
 * Senior Networking Software Engineer
 * Wind River Systems
 */

/*
 * This driver is designed to support RealTek's next generation of
 * 10/100 and 10/100/1000 PCI ethernet controllers. There are currently
 * four devices in this family: the RTL8139C+, the RTL8169, the RTL8169S
 * and the RTL8110S.
 *
 * The 8139C+ is a 10/100 ethernet chip. It is backwards compatible
 * with the older 8139 family, however it also supports a special
 * C+ mode of operation that provides several new performance enhancing
 * features. These include:
 *
 *      o Descriptor based DMA mechanism. Each descriptor represents
 *        a single packet fragment. Data buffers may be aligned on
 *        any byte boundary.
 *
 *      o 64-bit DMA
 *
 *      o TCP/IP checksum offload for both RX and TX
 *
 *      o High and normal priority transmit DMA rings
 *
 *      o VLAN tag insertion and extraction
 *
 *      o TCP large send (segmentation offload)
 *
 * Like the 8139, the 8139C+ also has a built-in 10/100 PHY. The C+
 * programming API is fairly straightforward. The RX filtering, EEPROM
 * access and PHY access is the same as it is on the older 8139 series
 * chips.
 *
 * The 8169 is a 64-bit 10/100/1000 gigabit ethernet MAC. It has almost the
 * same programming API and feature set as the 8139C+ with the following
 * differences and additions:
 *
 *      o 1000Mbps mode
 *
 *      o Jumbo frames
 *
 *      o GMII and TBI ports/registers for interfacing with copper
 *        or fiber PHYs
 *
 *      o RX and TX DMA rings can have up to 1024 descriptors
 *        (the 8139C+ allows a maximum of 64)
 *
 *      o Slight differences in register layout from the 8139C+
 *
 * The TX start and timer interrupt registers are at different locations
 * on the 8169 than they are on the 8139C+. Also, the status word in the
 * RX descriptor has a slightly different bit layout. The 8169 does not
 * have a built-in PHY. Most reference boards use a Marvell 88E1000 'Alaska'
 * copper gigE PHY.
 *
 * The 8169S/8110S 10/100/1000 devices have built-in copper gigE PHYs
 * (the 'S' stands for 'single-chip'). These devices have the same
 * programming API as the older 8169, but also have some vendor-specific
 * registers for the on-board PHY. The 8110S is a LAN-on-motherboard
 * part designed to be pin-compatible with the RealTek 8100 10/100 chip.
 *
 * This driver takes advantage of the RX and TX checksum offload and
 * VLAN tag insertion/extraction features. It also implements TX
 * interrupt moderation using the timer interrupt registers, which
 * significantly reduces TX interrupt load. There is also support
 * for jumbo frames, however the 8169/8169S/8110S can not transmit
 * jumbo frames larger than 7440, so the max MTU possible with this
 * driver is 7422 bytes.
 */

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

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

#include <net/bpf.h>

#include <machine/bus_pio.h>
#include <machine/bus_memio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

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

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

MODULE_DEPEND(re, pci, 1, 1, 1);
MODULE_DEPEND(re, ether, 1, 1, 1);
MODULE_DEPEND(re, miibus, 1, 1, 1);

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

/*
 * Default to using PIO access for this driver.
 */
#define RE_USEIOSPACE

#include <pci/if_rlreg.h>

#define RE_CSUM_FEATURES    (CSUM_IP | CSUM_TCP | CSUM_UDP)

/*
 * Various supported device vendors/types and their names.
 */
static struct rl_type re_devs[] = {
        { RT_VENDORID, RT_DEVICEID_8139, RL_HWREV_8139CPLUS,
                "RealTek 8139C+ 10/100BaseTX" },
        { RT_VENDORID, RT_DEVICEID_8169, RL_HWREV_8169,
                "RealTek 8169 Gigabit Ethernet" },
        { RT_VENDORID, RT_DEVICEID_8169, RL_HWREV_8169S,
                "RealTek 8169S Single-chip Gigabit Ethernet" },
        { RT_VENDORID, RT_DEVICEID_8169, RL_HWREV_8169SB,
                "RealTek 8169SB Single-chip Gigabit Ethernet" },
        { RT_VENDORID, RT_DEVICEID_8169, RL_HWREV_8110S,
                "RealTek 8110S Single-chip Gigabit Ethernet" },
        { COREGA_VENDORID, COREGA_DEVICEID_CGLAPCIGT, RL_HWREV_8169S,
                "Corega CG-LAPCIGT (RTL8169S) Gigabit Ethernet" },
        { 0, 0, 0, NULL }
};

static struct rl_hwrev re_hwrevs[] = {
        { RL_HWREV_8139, RL_8139,  "" },
        { RL_HWREV_8139A, RL_8139, "A" },
        { RL_HWREV_8139AG, RL_8139, "A-G" },
        { RL_HWREV_8139B, RL_8139, "B" },
        { RL_HWREV_8130, RL_8139, "8130" },
        { RL_HWREV_8139C, RL_8139, "C" },
        { RL_HWREV_8139D, RL_8139, "8139D/8100B/8100C" },
        { RL_HWREV_8139CPLUS, RL_8139CPLUS, "C+"},
        { RL_HWREV_8169, RL_8169, "8169"},
        { RL_HWREV_8169S, RL_8169, "8169S"},
        { RL_HWREV_8169SB, RL_8169, "8169SB"},
        { RL_HWREV_8110S, RL_8169, "8110S"},
        { RL_HWREV_8100, RL_8139, "8100"},
        { RL_HWREV_8101, RL_8139, "8101"},
        { 0, 0, NULL }
};

static int re_probe             (device_t);
static int re_attach            (device_t);
static int re_detach            (device_t);

static int re_encap             (struct rl_softc *, struct mbuf **, int *);

static void re_dma_map_addr     (void *, bus_dma_segment_t *, int, int);
static void re_dma_map_desc     (void *, bus_dma_segment_t *, int,
                                    bus_size_t, int);
static int re_allocmem          (device_t, struct rl_softc *);
static int re_newbuf            (struct rl_softc *, int, struct mbuf *);
static int re_rx_list_init      (struct rl_softc *);
static int re_tx_list_init      (struct rl_softc *);
#ifdef RE_FIXUP_RX
static __inline void re_fixup_rx
                                (struct mbuf *);
#endif
static void re_rxeof            (struct rl_softc *);
static void re_txeof            (struct rl_softc *);
#ifdef DEVICE_POLLING
static void re_poll             (struct ifnet *, enum poll_cmd, int);
static void re_poll_locked      (struct ifnet *, enum poll_cmd, int);
#endif
static void re_intr             (void *);
static void re_tick             (void *);
static void re_tick_locked      (struct rl_softc *);
static void re_start            (struct ifnet *);
static void re_start_locked     (struct ifnet *);
static int re_ioctl             (struct ifnet *, u_long, caddr_t);
static void re_init             (void *);
static void re_init_locked      (struct rl_softc *);
static void re_stop             (struct rl_softc *);
static void re_watchdog         (struct ifnet *);
static int re_suspend           (device_t);
static int re_resume            (device_t);
static void re_shutdown         (device_t);
static int re_ifmedia_upd       (struct ifnet *);
static void re_ifmedia_sts      (struct ifnet *, struct ifmediareq *);

static void re_eeprom_putbyte   (struct rl_softc *, int);
static void re_eeprom_getword   (struct rl_softc *, int, u_int16_t *);
static void re_read_eeprom      (struct rl_softc *, caddr_t, int, int, int);
static int re_gmii_readreg      (device_t, int, int);
static int re_gmii_writereg     (device_t, int, int, int);

static int re_miibus_readreg    (device_t, int, int);
static int re_miibus_writereg   (device_t, int, int, int);
static void re_miibus_statchg   (device_t);

static void re_setmulti         (struct rl_softc *);
static void re_reset            (struct rl_softc *);

static int re_diag              (struct rl_softc *);

#ifdef RE_USEIOSPACE
#define RL_RES                  SYS_RES_IOPORT
#define RL_RID                  RL_PCI_LOIO
#else
#define RL_RES                  SYS_RES_MEMORY
#define RL_RID                  RL_PCI_LOMEM
#endif

static device_method_t re_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         re_probe),
        DEVMETHOD(device_attach,        re_attach),
        DEVMETHOD(device_detach,        re_detach),
        DEVMETHOD(device_suspend,       re_suspend),
        DEVMETHOD(device_resume,        re_resume),
        DEVMETHOD(device_shutdown,      re_shutdown),

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

        /* MII interface */
        DEVMETHOD(miibus_readreg,       re_miibus_readreg),
        DEVMETHOD(miibus_writereg,      re_miibus_writereg),
        DEVMETHOD(miibus_statchg,       re_miibus_statchg),

        { 0, 0 }
};

static driver_t re_driver = {
        "re",
        re_methods,
        sizeof(struct rl_softc)
};

static devclass_t re_devclass;

DRIVER_MODULE(re, pci, re_driver, re_devclass, 0, 0);
DRIVER_MODULE(re, cardbus, re_driver, re_devclass, 0, 0);
DRIVER_MODULE(miibus, re, miibus_driver, miibus_devclass, 0, 0);

#define EE_SET(x)                                       \
        CSR_WRITE_1(sc, RL_EECMD,                       \
                CSR_READ_1(sc, RL_EECMD) | x)

#define EE_CLR(x)                                       \
        CSR_WRITE_1(sc, RL_EECMD,                       \
                CSR_READ_1(sc, RL_EECMD) & ~x)

/*
 * Send a read command and address to the EEPROM, check for ACK.
 */
static void
re_eeprom_putbyte(sc, addr)
        struct rl_softc         *sc;
        int                     addr;
{
        register int            d, i;

        d = addr | sc->rl_eecmd_read;

        /*
         * Feed in each bit and strobe the clock.
         */
        for (i = 0x400; i; i >>= 1) {
                if (d & i) {
                        EE_SET(RL_EE_DATAIN);
                } else {
                        EE_CLR(RL_EE_DATAIN);
                }
                DELAY(100);
                EE_SET(RL_EE_CLK);
                DELAY(150);
                EE_CLR(RL_EE_CLK);
                DELAY(100);
        }
}

/*
 * Read a word of data stored in the EEPROM at address 'addr.'
 */
static void
re_eeprom_getword(sc, addr, dest)
        struct rl_softc         *sc;
        int                     addr;
        u_int16_t               *dest;
{
        register int            i;
        u_int16_t               word = 0;

        /* Enter EEPROM access mode. */
        CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_PROGRAM|RL_EE_SEL);

        /*
         * Send address of word we want to read.
         */
        re_eeprom_putbyte(sc, addr);

        CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_PROGRAM|RL_EE_SEL);

        /*
         * Start reading bits from EEPROM.
         */
        for (i = 0x8000; i; i >>= 1) {
                EE_SET(RL_EE_CLK);
                DELAY(100);
                if (CSR_READ_1(sc, RL_EECMD) & RL_EE_DATAOUT)
                        word |= i;
                EE_CLR(RL_EE_CLK);
                DELAY(100);
        }

        /* Turn off EEPROM access mode. */
        CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_OFF);

        *dest = word;
}

/*
 * Read a sequence of words from the EEPROM.
 */
static void
re_read_eeprom(sc, dest, off, cnt, swap)
        struct rl_softc         *sc;
        caddr_t                 dest;
        int                     off;
        int                     cnt;
        int                     swap;
{
        int                     i;
        u_int16_t               word = 0, *ptr;

        for (i = 0; i < cnt; i++) {
                re_eeprom_getword(sc, off + i, &word);
                ptr = (u_int16_t *)(dest + (i * 2));
                if (swap)
                        *ptr = ntohs(word);
                else
                        *ptr = word;
        }
}

static int
re_gmii_readreg(dev, phy, reg)
        device_t                dev;
        int                     phy, reg;
{
        struct rl_softc         *sc;
        u_int32_t               rval;
        int                     i;

        if (phy != 1)
                return (0);

        sc = device_get_softc(dev);

        /* Let the rgephy driver read the GMEDIASTAT register */

        if (reg == RL_GMEDIASTAT) {
                rval = CSR_READ_1(sc, RL_GMEDIASTAT);
                return (rval);
        }

        CSR_WRITE_4(sc, RL_PHYAR, reg << 16);
        DELAY(1000);

        for (i = 0; i < RL_TIMEOUT; i++) {
                rval = CSR_READ_4(sc, RL_PHYAR);
                if (rval & RL_PHYAR_BUSY)
                        break;
                DELAY(100);
        }

        if (i == RL_TIMEOUT) {
                printf ("re%d: PHY read failed\n", sc->rl_unit);
                return (0);
        }

        return (rval & RL_PHYAR_PHYDATA);
}

static int
re_gmii_writereg(dev, phy, reg, data)
        device_t                dev;
        int                     phy, reg, data;
{
        struct rl_softc         *sc;
        u_int32_t               rval;
        int                     i;

        sc = device_get_softc(dev);

        CSR_WRITE_4(sc, RL_PHYAR, (reg << 16) |
            (data & RL_PHYAR_PHYDATA) | RL_PHYAR_BUSY);
        DELAY(1000);

        for (i = 0; i < RL_TIMEOUT; i++) {
                rval = CSR_READ_4(sc, RL_PHYAR);
                if (!(rval & RL_PHYAR_BUSY))
                        break;
                DELAY(100);
        }

        if (i == RL_TIMEOUT) {
                printf ("re%d: PHY write failed\n", sc->rl_unit);
                return (0);
        }

        return (0);
}

static int
re_miibus_readreg(dev, phy, reg)
        device_t                dev;
        int                     phy, reg;
{
        struct rl_softc         *sc;
        u_int16_t               rval = 0;
        u_int16_t               re8139_reg = 0;

        sc = device_get_softc(dev);

        if (sc->rl_type == RL_8169) {
                rval = re_gmii_readreg(dev, phy, reg);
                return (rval);
        }

        /* Pretend the internal PHY is only at address 0 */
        if (phy) {
                return (0);
        }
        switch (reg) {
        case MII_BMCR:
                re8139_reg = RL_BMCR;
                break;
        case MII_BMSR:
                re8139_reg = RL_BMSR;
                break;
        case MII_ANAR:
                re8139_reg = RL_ANAR;
                break;
        case MII_ANER:
                re8139_reg = RL_ANER;
                break;
        case MII_ANLPAR:
                re8139_reg = RL_LPAR;
                break;
        case MII_PHYIDR1:
        case MII_PHYIDR2:
                return (0);
        /*
         * Allow the rlphy driver to read the media status
         * register. If we have a link partner which does not
         * support NWAY, this is the register which will tell
         * us the results of parallel detection.
         */
        case RL_MEDIASTAT:
                rval = CSR_READ_1(sc, RL_MEDIASTAT);
                return (rval);
        default:
                printf("re%d: bad phy register\n", sc->rl_unit);
                return (0);
        }
        rval = CSR_READ_2(sc, re8139_reg);
        return (rval);
}

static int
re_miibus_writereg(dev, phy, reg, data)
        device_t                dev;
        int                     phy, reg, data;
{
        struct rl_softc         *sc;
        u_int16_t               re8139_reg = 0;
        int                     rval = 0;

        sc = device_get_softc(dev);

        if (sc->rl_type == RL_8169) {
                rval = re_gmii_writereg(dev, phy, reg, data);
                return (rval);
        }

        /* Pretend the internal PHY is only at address 0 */
        if (phy)
                return (0);

        switch (reg) {
        case MII_BMCR:
                re8139_reg = RL_BMCR;
                break;
        case MII_BMSR:
                re8139_reg = RL_BMSR;
                break;
        case MII_ANAR:
                re8139_reg = RL_ANAR;
                break;
        case MII_ANER:
                re8139_reg = RL_ANER;
                break;
        case MII_ANLPAR:
                re8139_reg = RL_LPAR;
                break;
        case MII_PHYIDR1:
        case MII_PHYIDR2:
                return (0);
                break;
        default:
                printf("re%d: bad phy register\n", sc->rl_unit);
                return (0);
        }
        CSR_WRITE_2(sc, re8139_reg, data);
        return (0);
}

static void
re_miibus_statchg(dev)
        device_t                dev;
{

}

/*
 * Program the 64-bit multicast hash filter.
 */
static void
re_setmulti(sc)
        struct rl_softc         *sc;
{
        struct ifnet            *ifp;
        int                     h = 0;
        u_int32_t               hashes[2] = { 0, 0 };
        struct ifmultiaddr      *ifma;
        u_int32_t               rxfilt;
        int                     mcnt = 0;

        RL_LOCK_ASSERT(sc);

        ifp = &sc->arpcom.ac_if;

        rxfilt = CSR_READ_4(sc, RL_RXCFG);

        if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC) {
                rxfilt |= RL_RXCFG_RX_MULTI;
                CSR_WRITE_4(sc, RL_RXCFG, rxfilt);
                CSR_WRITE_4(sc, RL_MAR0, 0xFFFFFFFF);
                CSR_WRITE_4(sc, RL_MAR4, 0xFFFFFFFF);
                return;
        }

        /* first, zot all the existing hash bits */
        CSR_WRITE_4(sc, RL_MAR0, 0);
        CSR_WRITE_4(sc, RL_MAR4, 0);

        /* now program new ones */
        TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                h = ether_crc32_be(LLADDR((struct sockaddr_dl *)
                    ifma->ifma_addr), ETHER_ADDR_LEN) >> 26;
                if (h < 32)
                        hashes[0] |= (1 << h);
                else
                        hashes[1] |= (1 << (h - 32));
                mcnt++;
        }

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

        CSR_WRITE_4(sc, RL_RXCFG, rxfilt);
        CSR_WRITE_4(sc, RL_MAR0, hashes[0]);
        CSR_WRITE_4(sc, RL_MAR4, hashes[1]);
}

static void
re_reset(sc)
        struct rl_softc         *sc;
{
        register int            i;

        RL_LOCK_ASSERT(sc);

        CSR_WRITE_1(sc, RL_COMMAND, RL_CMD_RESET);

        for (i = 0; i < RL_TIMEOUT; i++) {
                DELAY(10);
                if (!(CSR_READ_1(sc, RL_COMMAND) & RL_CMD_RESET))
                        break;
        }
        if (i == RL_TIMEOUT)
                printf("re%d: reset never completed!\n", sc->rl_unit);

        CSR_WRITE_1(sc, 0x82, 1);
}

/*
 * The following routine is designed to test for a defect on some
 * 32-bit 8169 cards. Some of these NICs have the REQ64# and ACK64#
 * lines connected to the bus, however for a 32-bit only card, they
 * should be pulled high. The result of this defect is that the
 * NIC will not work right if you plug it into a 64-bit slot: DMA
 * operations will be done with 64-bit transfers, which will fail
 * because the 64-bit data lines aren't connected.
 *
 * There's no way to work around this (short of talking a soldering
 * iron to the board), however we can detect it. The method we use
 * here is to put the NIC into digital loopback mode, set the receiver
 * to promiscuous mode, and then try to send a frame. We then compare
 * the frame data we sent to what was received. If the data matches,
 * then the NIC is working correctly, otherwise we know the user has
 * a defective NIC which has been mistakenly plugged into a 64-bit PCI
 * slot. In the latter case, there's no way the NIC can work correctly,
 * so we print out a message on the console and abort the device attach.
 */

static int
re_diag(sc)
        struct rl_softc         *sc;
{
        struct ifnet            *ifp = &sc->arpcom.ac_if;
        struct mbuf             *m0;
        struct ether_header     *eh;
        struct rl_desc          *cur_rx;
        u_int16_t               status;
        u_int32_t               rxstat;
        int                     total_len, i, error = 0;
        u_int8_t                dst[] = { 0x00, 'h', 'e', 'l', 'l', 'o' };
        u_int8_t                src[] = { 0x00, 'w', 'o', 'r', 'l', 'd' };

        /* Allocate a single mbuf */
        MGETHDR(m0, M_DONTWAIT, MT_DATA);
        if (m0 == NULL)
                return (ENOBUFS);

        RL_LOCK(sc);

        /*
         * Initialize the NIC in test mode. This sets the chip up
         * so that it can send and receive frames, but performs the
         * following special functions:
         * - Puts receiver in promiscuous mode
         * - Enables digital loopback mode
         * - Leaves interrupts turned off
         */

        ifp->if_flags |= IFF_PROMISC;
        sc->rl_testmode = 1;
        re_init_locked(sc);
        re_stop(sc);
        DELAY(100000);
        re_init_locked(sc);

        /* Put some data in the mbuf */

        eh = mtod(m0, struct ether_header *);
        bcopy ((char *)&dst, eh->ether_dhost, ETHER_ADDR_LEN);
        bcopy ((char *)&src, eh->ether_shost, ETHER_ADDR_LEN);
        eh->ether_type = htons(ETHERTYPE_IP);
        m0->m_pkthdr.len = m0->m_len = ETHER_MIN_LEN - ETHER_CRC_LEN;

        /*
         * Queue the packet, start transmission.
         * Note: IF_HANDOFF() ultimately calls re_start() for us.
         */

        CSR_WRITE_2(sc, RL_ISR, 0xFFFF);
        RL_UNLOCK(sc);
        /* XXX: re_diag must not be called when in ALTQ mode */
        IF_HANDOFF(&ifp->if_snd, m0, ifp);
        RL_LOCK(sc);
        m0 = NULL;

        /* Wait for it to propagate through the chip */

        DELAY(100000);
        for (i = 0; i < RL_TIMEOUT; i++) {
                status = CSR_READ_2(sc, RL_ISR);
                if ((status & (RL_ISR_TIMEOUT_EXPIRED|RL_ISR_RX_OK)) ==
                    (RL_ISR_TIMEOUT_EXPIRED|RL_ISR_RX_OK))
                        break;
                DELAY(10);
        }

        if (i == RL_TIMEOUT) {
                printf("re%d: diagnostic failed, failed to receive packet "
                    "in loopback mode\n", sc->rl_unit);
                error = EIO;
                goto done;
        }

        /*
         * The packet should have been dumped into the first
         * entry in the RX DMA ring. Grab it from there.
         */

        bus_dmamap_sync(sc->rl_ldata.rl_rx_list_tag,
            sc->rl_ldata.rl_rx_list_map,
            BUS_DMASYNC_POSTREAD);
        bus_dmamap_sync(sc->rl_ldata.rl_mtag,
            sc->rl_ldata.rl_rx_dmamap[0],
            BUS_DMASYNC_POSTWRITE);
        bus_dmamap_unload(sc->rl_ldata.rl_mtag,
            sc->rl_ldata.rl_rx_dmamap[0]);

        m0 = sc->rl_ldata.rl_rx_mbuf[0];
        sc->rl_ldata.rl_rx_mbuf[0] = NULL;
        eh = mtod(m0, struct ether_header *);

        cur_rx = &sc->rl_ldata.rl_rx_list[0];
        total_len = RL_RXBYTES(cur_rx);
        rxstat = le32toh(cur_rx->rl_cmdstat);

        if (total_len != ETHER_MIN_LEN) {
                printf("re%d: diagnostic failed, received short packet\n",
                    sc->rl_unit);
                error = EIO;
                goto done;
        }

        /* Test that the received packet data matches what we sent. */

        if (bcmp((char *)&eh->ether_dhost, (char *)&dst, ETHER_ADDR_LEN) ||
            bcmp((char *)&eh->ether_shost, (char *)&src, ETHER_ADDR_LEN) ||
            ntohs(eh->ether_type) != ETHERTYPE_IP) {
                printf("re%d: WARNING, DMA FAILURE!\n", sc->rl_unit);
                printf("re%d: expected TX data: %6D/%6D/0x%x\n", sc->rl_unit,
                    dst, ":", src, ":", ETHERTYPE_IP);
                printf("re%d: received RX data: %6D/%6D/0x%x\n", sc->rl_unit,
                    eh->ether_dhost, ":",  eh->ether_shost, ":",
                    ntohs(eh->ether_type));
                printf("re%d: You may have a defective 32-bit NIC plugged "
                    "into a 64-bit PCI slot.\n", sc->rl_unit);
                printf("re%d: Please re-install the NIC in a 32-bit slot "
                    "for proper operation.\n", sc->rl_unit);
                printf("re%d: Read the re(4) man page for more details.\n",
                    sc->rl_unit);
                error = EIO;
        }

done:
        /* Turn interface off, release resources */

        sc->rl_testmode = 0;
        ifp->if_flags &= ~IFF_PROMISC;
        re_stop(sc);
        if (m0 != NULL)
                m_freem(m0);

        RL_UNLOCK(sc);

        return (error);
}

/*
 * Probe for a RealTek 8139C+/8169/8110 chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 */
static int
re_probe(dev)
        device_t                dev;
{
        struct rl_type          *t;
        struct rl_softc         *sc;
        int                     rid;
        u_int32_t               hwrev;

        t = re_devs;
        sc = device_get_softc(dev);

        while (t->rl_name != NULL) {
                if ((pci_get_vendor(dev) == t->rl_vid) &&
                    (pci_get_device(dev) == t->rl_did)) {

                        /*
                         * Temporarily map the I/O space
                         * so we can read the chip ID register.
                         */
                        rid = RL_RID;
                        sc->rl_res = bus_alloc_resource_any(dev, RL_RES, &rid,
                            RF_ACTIVE);
                        if (sc->rl_res == NULL) {
                                device_printf(dev,
                                    "couldn't map ports/memory\n");
                                return (ENXIO);
                        }
                        sc->rl_btag = rman_get_bustag(sc->rl_res);
                        sc->rl_bhandle = rman_get_bushandle(sc->rl_res);
                        hwrev = CSR_READ_4(sc, RL_TXCFG) & RL_TXCFG_HWREV;
                        bus_release_resource(dev, RL_RES,
                            RL_RID, sc->rl_res);
                        if (t->rl_basetype == hwrev) {
                                device_set_desc(dev, t->rl_name);
                                return (BUS_PROBE_DEFAULT);
                        }
                }
                t++;
        }

        return (ENXIO);
}

/*
 * This routine takes the segment list provided as the result of
 * a bus_dma_map_load() operation and assigns the addresses/lengths
 * to RealTek DMA descriptors. This can be called either by the RX
 * code or the TX code. In the RX case, we'll probably wind up mapping
 * at most one segment. For the TX case, there could be any number of
 * segments since TX packets may span multiple mbufs. In either case,
 * if the number of segments is larger than the rl_maxsegs limit
 * specified by the caller, we abort the mapping operation. Sadly,
 * whoever designed the buffer mapping API did not provide a way to
 * return an error from here, so we have to fake it a bit.
 */

static void
re_dma_map_desc(arg, segs, nseg, mapsize, error)
        void                    *arg;
        bus_dma_segment_t       *segs;
        int                     nseg;
        bus_size_t              mapsize;
        int                     error;
{
        struct rl_dmaload_arg   *ctx;
        struct rl_desc          *d = NULL;
        int                     i = 0, idx;

        if (error)
                return;

        ctx = arg;

        /* Signal error to caller if there's too many segments */
        if (nseg > ctx->rl_maxsegs) {
                ctx->rl_maxsegs = 0;
                return;
        }

        /*
         * Map the segment array into descriptors. Note that we set the
         * start-of-frame and end-of-frame markers for either TX or RX, but
         * they really only have meaning in the TX case. (In the RX case,
         * it's the chip that tells us where packets begin and end.)
         * We also keep track of the end of the ring and set the
         * end-of-ring bits as needed, and we set the ownership bits
         * in all except the very first descriptor. (The caller will
         * set this descriptor later when it start transmission or
         * reception.)
         */
        idx = ctx->rl_idx;
        for (;;) {
                u_int32_t               cmdstat;
                d = &ctx->rl_ring[idx];
                if (le32toh(d->rl_cmdstat) & RL_RDESC_STAT_OWN) {
                        ctx->rl_maxsegs = 0;
                        return;
                }
                cmdstat = segs[i].ds_len;
                d->rl_bufaddr_lo = htole32(RL_ADDR_LO(segs[i].ds_addr));
                d->rl_bufaddr_hi = htole32(RL_ADDR_HI(segs[i].ds_addr));
                if (i == 0)
                        cmdstat |= RL_TDESC_CMD_SOF;
                else
                        cmdstat |= RL_TDESC_CMD_OWN;
                if (idx == (RL_RX_DESC_CNT - 1))
                        cmdstat |= RL_TDESC_CMD_EOR;
                d->rl_cmdstat = htole32(cmdstat | ctx->rl_flags);
                i++;
                if (i == nseg)
                        break;
                RL_DESC_INC(idx);
        }

        d->rl_cmdstat |= htole32(RL_TDESC_CMD_EOF);
        ctx->rl_maxsegs = nseg;
        ctx->rl_idx = idx;
}

/*
 * Map a single buffer address.
 */

static void
re_dma_map_addr(arg, segs, nseg, error)
        void                    *arg;
        bus_dma_segment_t       *segs;
        int                     nseg;
        int                     error;
{
        u_int32_t               *addr;

        if (error)
                return;

        KASSERT(nseg == 1, ("too many DMA segments, %d should be 1", nseg));
        addr = arg;
        *addr = segs->ds_addr;
}

static int
re_allocmem(dev, sc)
        device_t                dev;
        struct rl_softc         *sc;
{
        int                     error;
        int                     nseg;
        int                     i;

        /*
         * Allocate map for RX mbufs.
         */
        nseg = 32;
        error = bus_dma_tag_create(sc->rl_parent_tag, ETHER_ALIGN, 0,
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL,
            NULL, MCLBYTES * nseg, nseg, MCLBYTES, BUS_DMA_ALLOCNOW,
            NULL, NULL, &sc->rl_ldata.rl_mtag);
        if (error) {
                device_printf(dev, "could not allocate dma tag\n");
                return (ENOMEM);
        }

        /*
         * Allocate map for TX descriptor list.
         */
        error = bus_dma_tag_create(sc->rl_parent_tag, RL_RING_ALIGN,
            0, BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL,
            NULL, RL_TX_LIST_SZ, 1, RL_TX_LIST_SZ, BUS_DMA_ALLOCNOW,
            NULL, NULL, &sc->rl_ldata.rl_tx_list_tag);
        if (error) {
                device_printf(dev, "could not allocate dma tag\n");
                return (ENOMEM);
        }

        /* Allocate DMA'able memory for the TX ring */

        error = bus_dmamem_alloc(sc->rl_ldata.rl_tx_list_tag,
            (void **)&sc->rl_ldata.rl_tx_list, BUS_DMA_NOWAIT | BUS_DMA_ZERO,
            &sc->rl_ldata.rl_tx_list_map);
        if (error)
                return (ENOMEM);

        /* Load the map for the TX ring. */

        error = bus_dmamap_load(sc->rl_ldata.rl_tx_list_tag,
             sc->rl_ldata.rl_tx_list_map, sc->rl_ldata.rl_tx_list,
             RL_TX_LIST_SZ, re_dma_map_addr,
             &sc->rl_ldata.rl_tx_list_addr, BUS_DMA_NOWAIT);

        /* Create DMA maps for TX buffers */

        for (i = 0; i < RL_TX_DESC_CNT; i++) {
                error = bus_dmamap_create(sc->rl_ldata.rl_mtag, 0,
                            &sc->rl_ldata.rl_tx_dmamap[i]);
                if (error) {
                        device_printf(dev, "can't create DMA map for TX\n");
                        return (ENOMEM);
                }
        }

        /*
         * Allocate map for RX descriptor list.
         */
        error = bus_dma_tag_create(sc->rl_parent_tag, RL_RING_ALIGN,
            0, BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL,
            NULL, RL_RX_LIST_SZ, 1, RL_RX_LIST_SZ, BUS_DMA_ALLOCNOW,
            NULL, NULL, &sc->rl_ldata.rl_rx_list_tag);
        if (error) {
                device_printf(dev, "could not allocate dma tag\n");
                return (ENOMEM);
        }

        /* Allocate DMA'able memory for the RX ring */

        error = bus_dmamem_alloc(sc->rl_ldata.rl_rx_list_tag,
            (void **)&sc->rl_ldata.rl_rx_list, BUS_DMA_NOWAIT | BUS_DMA_ZERO,
            &sc->rl_ldata.rl_rx_list_map);
        if (error)
                return (ENOMEM);

        /* Load the map for the RX ring. */

        error = bus_dmamap_load(sc->rl_ldata.rl_rx_list_tag,
             sc->rl_ldata.rl_rx_list_map, sc->rl_ldata.rl_rx_list,
             RL_RX_LIST_SZ, re_dma_map_addr,
             &sc->rl_ldata.rl_rx_list_addr, BUS_DMA_NOWAIT);

        /* Create DMA maps for RX buffers */

        for (i = 0; i < RL_RX_DESC_CNT; i++) {
                error = bus_dmamap_create(sc->rl_ldata.rl_mtag, 0,
                            &sc->rl_ldata.rl_rx_dmamap[i]);
                if (error) {
                        device_printf(dev, "can't create DMA map for RX\n");
                        return (ENOMEM);
                }
        }

        return (0);
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
re_attach(dev)
        device_t                dev;
{
        u_char                  eaddr[ETHER_ADDR_LEN];
        u_int16_t               as[3];
        struct rl_softc         *sc;
        struct ifnet            *ifp;
        struct rl_hwrev         *hw_rev;
        int                     hwrev;
        u_int16_t               re_did = 0;
        int                     unit, error = 0, rid, i;

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

        mtx_init(&sc->rl_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
            MTX_DEF);
        /*
         * Map control/status registers.
         */
        pci_enable_busmaster(dev);

        rid = RL_RID;
        sc->rl_res = bus_alloc_resource_any(dev, RL_RES, &rid,
            RF_ACTIVE);

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

        sc->rl_btag = rman_get_bustag(sc->rl_res);
        sc->rl_bhandle = rman_get_bushandle(sc->rl_res);

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

        if (sc->rl_irq == NULL) {
                printf("re%d: couldn't map interrupt\n", unit);
                error = ENXIO;
                goto fail;
        }

        /* Reset the adapter. */
        RL_LOCK(sc);
        re_reset(sc);
        RL_UNLOCK(sc);

        hw_rev = re_hwrevs;
        hwrev = CSR_READ_4(sc, RL_TXCFG) & RL_TXCFG_HWREV;
        while (hw_rev->rl_desc != NULL) {
                if (hw_rev->rl_rev == hwrev) {
                        sc->rl_type = hw_rev->rl_type;
                        break;
                }
                hw_rev++;
        }

        if (sc->rl_type == RL_8169) {

                /* Set RX length mask */

                sc->rl_rxlenmask = RL_RDESC_STAT_GFRAGLEN;

                /* Force station address autoload from the EEPROM */

                CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_AUTOLOAD);
                for (i = 0; i < RL_TIMEOUT; i++) {
                        if (!(CSR_READ_1(sc, RL_EECMD) & RL_EEMODE_AUTOLOAD))
                                break;
                        DELAY(100);
                }
                if (i == RL_TIMEOUT)
                        printf ("re%d: eeprom autoload timed out\n", unit);

                        for (i = 0; i < ETHER_ADDR_LEN; i++)
                                eaddr[i] = CSR_READ_1(sc, RL_IDR0 + i);
        } else {

                /* Set RX length mask */

                sc->rl_rxlenmask = RL_RDESC_STAT_FRAGLEN;

                sc->rl_eecmd_read = RL_EECMD_READ_6BIT;
                re_read_eeprom(sc, (caddr_t)&re_did, 0, 1, 0);
                if (re_did != 0x8129)
                        sc->rl_eecmd_read = RL_EECMD_READ_8BIT;

                /*
                 * Get station address from the EEPROM.
                 */
                re_read_eeprom(sc, (caddr_t)as, RL_EE_EADDR, 3, 0);
                for (i = 0; i < 3; i++) {
                        eaddr[(i * 2) + 0] = as[i] & 0xff;
                        eaddr[(i * 2) + 1] = as[i] >> 8;
                }
        }

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

        /*
         * Allocate the parent bus DMA tag appropriate for PCI.
         */
#define RL_NSEG_NEW 32
        error = bus_dma_tag_create(NULL,        /* parent */
                        1, 0,                   /* alignment, boundary */
                        BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                        BUS_SPACE_MAXADDR,      /* highaddr */
                        NULL, NULL,             /* filter, filterarg */
                        MAXBSIZE, RL_NSEG_NEW,  /* maxsize, nsegments */
                        BUS_SPACE_MAXSIZE_32BIT,/* maxsegsize */
                        BUS_DMA_ALLOCNOW,       /* flags */
                        NULL, NULL,             /* lockfunc, lockarg */
                        &sc->rl_parent_tag);
        if (error)
                goto fail;

        error = re_allocmem(dev, sc);

        if (error)
                goto fail;

        /* Do MII setup */
        if (mii_phy_probe(dev, &sc->rl_miibus,
            re_ifmedia_upd, re_ifmedia_sts)) {
                printf("re%d: MII without any phy!\n", sc->rl_unit);
                error = ENXIO;
                goto fail;
        }

        ifp = &sc->arpcom.ac_if;
        ifp->if_softc = sc;
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));
        ifp->if_mtu = ETHERMTU;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = re_ioctl;
        ifp->if_capabilities = IFCAP_VLAN_MTU;
        ifp->if_start = re_start;
        ifp->if_hwassist = /*RE_CSUM_FEATURES*/0;
        ifp->if_capabilities |= IFCAP_HWCSUM|IFCAP_VLAN_HWTAGGING;
#ifdef DEVICE_POLLING
        ifp->if_capabilities |= IFCAP_POLLING;
#endif
        ifp->if_watchdog = re_watchdog;
        ifp->if_init = re_init;
        if (sc->rl_type == RL_8169)
                ifp->if_baudrate = 1000000000;
        else
                ifp->if_baudrate = 100000000;
        IFQ_SET_MAXLEN(&ifp->if_snd,  RL_IFQ_MAXLEN);
        ifp->if_snd.ifq_drv_maxlen = RL_IFQ_MAXLEN;
        IFQ_SET_READY(&ifp->if_snd);
        ifp->if_capenable = ifp->if_capabilities & ~IFCAP_HWCSUM;

        callout_handle_init(&sc->rl_stat_ch);

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

        /* Perform hardware diagnostic. */
        error = re_diag(sc);

        if (error) {
                printf("re%d: attach aborted due to hardware diag failure\n",
                    unit);
                ether_ifdetach(ifp);
                goto fail;
        }

        /* Hook interrupt last to avoid having to lock softc */
        error = bus_setup_intr(dev, sc->rl_irq, INTR_TYPE_NET | INTR_MPSAFE,
            re_intr, sc, &sc->rl_intrhand);
        if (error) {
                printf("re%d: couldn't set up irq\n", unit);
                ether_ifdetach(ifp);
        }

fail:
        if (error)
                re_detach(dev);

        return (error);
}

/*
 * Shutdown hardware and free up resources. This can be called any
 * time after the mutex has been initialized. It is called in both
 * the error case in attach and the normal detach case so it needs
 * to be careful about only freeing resources that have actually been
 * allocated.
 */
static int
re_detach(dev)
        device_t                dev;
{
        struct rl_softc         *sc;
        struct ifnet            *ifp;
        int                     i;
        int                     attached;

        sc = device_get_softc(dev);
        ifp = &sc->arpcom.ac_if;
        KASSERT(mtx_initialized(&sc->rl_mtx), ("re mutex not initialized"));

        attached = device_is_attached(dev);
        /* These should only be active if attach succeeded */
        if (attached)
                ether_ifdetach(ifp);

        RL_LOCK(sc);
#if 0
        sc->suspended = 1;
#endif

        /* These should only be active if attach succeeded */
        if (attached) {
                re_stop(sc);
                /*
                 * Force off the IFF_UP flag here, in case someone
                 * still had a BPF descriptor attached to this
                 * interface. If they do, ether_ifdetach() will cause
                 * the BPF code to try and clear the promisc mode
                 * flag, which will bubble down to re_ioctl(),
                 * which will try to call re_init() again. This will
                 * turn the NIC back on and restart the MII ticker,
                 * which will panic the system when the kernel tries
                 * to invoke the re_tick() function that isn't there
                 * anymore.
                 */
                ifp->if_flags &= ~IFF_UP;
        }
        if (sc->rl_miibus)
                device_delete_child(dev, sc->rl_miibus);
        bus_generic_detach(dev);

        /*
         * The rest is resource deallocation, so we should already be
         * stopped here.
         */
        RL_UNLOCK(sc);

        if (sc->rl_intrhand)
                bus_teardown_intr(dev, sc->rl_irq, sc->rl_intrhand);
        if (sc->rl_irq)
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->rl_irq);
        if (sc->rl_res)
                bus_release_resource(dev, RL_RES, RL_RID, sc->rl_res);


        /* Unload and free the RX DMA ring memory and map */

        if (sc->rl_ldata.rl_rx_list_tag) {
                bus_dmamap_unload(sc->rl_ldata.rl_rx_list_tag,
                    sc->rl_ldata.rl_rx_list_map);
                bus_dmamem_free(sc->rl_ldata.rl_rx_list_tag,
                    sc->rl_ldata.rl_rx_list,
                    sc->rl_ldata.rl_rx_list_map);
                bus_dma_tag_destroy(sc->rl_ldata.rl_rx_list_tag);
        }

        /* Unload and free the TX DMA ring memory and map */

        if (sc->rl_ldata.rl_tx_list_tag) {
                bus_dmamap_unload(sc->rl_ldata.rl_tx_list_tag,
                    sc->rl_ldata.rl_tx_list_map);
                bus_dmamem_free(sc->rl_ldata.rl_tx_list_tag,
                    sc->rl_ldata.rl_tx_list,
                    sc->rl_ldata.rl_tx_list_map);
                bus_dma_tag_destroy(sc->rl_ldata.rl_tx_list_tag);
        }

        /* Destroy all the RX and TX buffer maps */

        if (sc->rl_ldata.rl_mtag) {
                for (i = 0; i < RL_TX_DESC_CNT; i++)
                        bus_dmamap_destroy(sc->rl_ldata.rl_mtag,
                            sc->rl_ldata.rl_tx_dmamap[i]);
                for (i = 0; i < RL_RX_DESC_CNT; i++)
                        bus_dmamap_destroy(sc->rl_ldata.rl_mtag,
                            sc->rl_ldata.rl_rx_dmamap[i]);
                bus_dma_tag_destroy(sc->rl_ldata.rl_mtag);
        }

        /* Unload and free the stats buffer and map */

        if (sc->rl_ldata.rl_stag) {
                bus_dmamap_unload(sc->rl_ldata.rl_stag,
                    sc->rl_ldata.rl_rx_list_map);
                bus_dmamem_free(sc->rl_ldata.rl_stag,
                    sc->rl_ldata.rl_stats,
                    sc->rl_ldata.rl_smap);
                bus_dma_tag_destroy(sc->rl_ldata.rl_stag);
        }

        if (sc->rl_parent_tag)
                bus_dma_tag_destroy(sc->rl_parent_tag);

        mtx_destroy(&sc->rl_mtx);

        return (0);
}

static int
re_newbuf(sc, idx, m)
        struct rl_softc         *sc;
        int                     idx;
        struct mbuf             *m;
{
        struct rl_dmaload_arg   arg;
        struct mbuf             *n = NULL;
        int                     error;

        if (m == NULL) {
                n = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
                if (n == NULL)
                        return (ENOBUFS);
                m = n;
        } else
                m->m_data = m->m_ext.ext_buf;

        m->m_len = m->m_pkthdr.len = MCLBYTES;
#ifdef RE_FIXUP_RX
        /*
         * This is part of an evil trick to deal with non-x86 platforms.
         * The RealTek chip requires RX buffers to be aligned on 64-bit
         * boundaries, but that will hose non-x86 machines. To get around
         * this, we leave some empty space at the start of each buffer
         * and for non-x86 hosts, we copy the buffer back six bytes
         * to achieve word alignment. This is slightly more efficient
         * than allocating a new buffer, copying the contents, and
         * discarding the old buffer.
         */
        m_adj(m, RE_ETHER_ALIGN);
#endif
        arg.sc = sc;
        arg.rl_idx = idx;
        arg.rl_maxsegs = 1;
        arg.rl_flags = 0;
        arg.rl_ring = sc->rl_ldata.rl_rx_list;

        error = bus_dmamap_load_mbuf(sc->rl_ldata.rl_mtag,
            sc->rl_ldata.rl_rx_dmamap[idx], m, re_dma_map_desc,
            &arg, BUS_DMA_NOWAIT);
        if (error || arg.rl_maxsegs != 1) {
                if (n != NULL)
                        m_freem(n);
                return (ENOMEM);
        }

        sc->rl_ldata.rl_rx_list[idx].rl_cmdstat |= htole32(RL_RDESC_CMD_OWN);
        sc->rl_ldata.rl_rx_mbuf[idx] = m;

        bus_dmamap_sync(sc->rl_ldata.rl_mtag,
            sc->rl_ldata.rl_rx_dmamap[idx],
            BUS_DMASYNC_PREREAD);

        return (0);
}

#ifdef RE_FIXUP_RX
static __inline void
re_fixup_rx(m)
        struct mbuf             *m;
{
        int                     i;
        uint16_t                *src, *dst;

        src = mtod(m, uint16_t *);
        dst = src - (RE_ETHER_ALIGN - ETHER_ALIGN) / sizeof *src;

        for (i = 0; i < (m->m_len / sizeof(uint16_t) + 1); i++)
                *dst++ = *src++;

        m->m_data -= RE_ETHER_ALIGN - ETHER_ALIGN;

        return;
}
#endif

static int
re_tx_list_init(sc)
        struct rl_softc         *sc;
{

        RL_LOCK_ASSERT(sc);

        bzero ((char *)sc->rl_ldata.rl_tx_list, RL_TX_LIST_SZ);
        bzero ((char *)&sc->rl_ldata.rl_tx_mbuf,
            (RL_TX_DESC_CNT * sizeof(struct mbuf *)));

        bus_dmamap_sync(sc->rl_ldata.rl_tx_list_tag,
            sc->rl_ldata.rl_tx_list_map, BUS_DMASYNC_PREWRITE);
        sc->rl_ldata.rl_tx_prodidx = 0;
        sc->rl_ldata.rl_tx_considx = 0;
        sc->rl_ldata.rl_tx_free = RL_TX_DESC_CNT;

        return (0);
}

static int
re_rx_list_init(sc)
        struct rl_softc         *sc;
{
        int                     i;

        bzero ((char *)sc->rl_ldata.rl_rx_list, RL_RX_LIST_SZ);
        bzero ((char *)&sc->rl_ldata.rl_rx_mbuf,
            (RL_RX_DESC_CNT * sizeof(struct mbuf *)));

        for (i = 0; i < RL_RX_DESC_CNT; i++) {
                if (re_newbuf(sc, i, NULL) == ENOBUFS)
                        return (ENOBUFS);
        }

        /* Flush the RX descriptors */

        bus_dmamap_sync(sc->rl_ldata.rl_rx_list_tag,
            sc->rl_ldata.rl_rx_list_map,
            BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD);

        sc->rl_ldata.rl_rx_prodidx = 0;
        sc->rl_head = sc->rl_tail = NULL;

        return (0);
}

/*
 * RX handler for C+ and 8169. For the gigE chips, we support
 * the reception of jumbo frames that have been fragmented
 * across multiple 2K mbuf cluster buffers.
 */
static void
re_rxeof(sc)
        struct rl_softc         *sc;
{
        struct mbuf             *m;
        struct ifnet            *ifp;
        int                     i, total_len;
        struct rl_desc          *cur_rx;
        u_int32_t               rxstat, rxvlan;

        RL_LOCK_ASSERT(sc);

        ifp = &sc->arpcom.ac_if;
        i = sc->rl_ldata.rl_rx_prodidx;

        /* Invalidate the descriptor memory */

        bus_dmamap_sync(sc->rl_ldata.rl_rx_list_tag,
            sc->rl_ldata.rl_rx_list_map,
            BUS_DMASYNC_POSTREAD);

        while (!RL_OWN(&sc->rl_ldata.rl_rx_list[i])) {
                cur_rx = &sc->rl_ldata.rl_rx_list[i];
                m = sc->rl_ldata.rl_rx_mbuf[i];
                total_len = RL_RXBYTES(cur_rx);
                rxstat = le32toh(cur_rx->rl_cmdstat);
                rxvlan = le32toh(cur_rx->rl_vlanctl);

                /* Invalidate the RX mbuf and unload its map */

                bus_dmamap_sync(sc->rl_ldata.rl_mtag,
                    sc->rl_ldata.rl_rx_dmamap[i],
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(sc->rl_ldata.rl_mtag,
                    sc->rl_ldata.rl_rx_dmamap[i]);

                if (!(rxstat & RL_RDESC_STAT_EOF)) {
                        m->m_len = RE_RX_DESC_BUFLEN;
                        if (sc->rl_head == NULL)
                                sc->rl_head = sc->rl_tail = m;
                        else {
                                m->m_flags &= ~M_PKTHDR;
                                sc->rl_tail->m_next = m;
                                sc->rl_tail = m;
                        }
                        re_newbuf(sc, i, NULL);
                        RL_DESC_INC(i);
                        continue;
                }

                /*
                 * NOTE: for the 8139C+, the frame length field
                 * is always 12 bits in size, but for the gigE chips,
                 * it is 13 bits (since the max RX frame length is 16K).
                 * Unfortunately, all 32 bits in the status word
                 * were already used, so to make room for the extra
                 * length bit, RealTek took out the 'frame alignment
                 * error' bit and shifted the other status bits
                 * over one slot. The OWN, EOR, FS and LS bits are
                 * still in the same places. We have already extracted
                 * the frame length and checked the OWN bit, so rather
                 * than using an alternate bit mapping, we shift the
                 * status bits one space to the right so we can evaluate
                 * them using the 8169 status as though it was in the
                 * same format as that of the 8139C+.
                 */
                if (sc->rl_type == RL_8169)
                        rxstat >>= 1;

                /*
                 * if total_len > 2^13-1, both _RXERRSUM and _GIANT will be
                 * set, but if CRC is clear, it will still be a valid frame.
                 */
                if (rxstat & RL_RDESC_STAT_RXERRSUM && !(total_len > 8191 &&
                    (rxstat & RL_RDESC_STAT_ERRS) == RL_RDESC_STAT_GIANT)) {
                        ifp->if_ierrors++;
                        /*
                         * If this is part of a multi-fragment packet,
                         * discard all the pieces.
                         */
                        if (sc->rl_head != NULL) {
                                m_freem(sc->rl_head);
                                sc->rl_head = sc->rl_tail = NULL;
                        }
                        re_newbuf(sc, i, m);
                        RL_DESC_INC(i);
                        continue;
                }

                /*
                 * If allocating a replacement mbuf fails,
                 * reload the current one.
                 */

                if (re_newbuf(sc, i, NULL)) {
                        ifp->if_ierrors++;
                        if (sc->rl_head != NULL) {
                                m_freem(sc->rl_head);
                                sc->rl_head = sc->rl_tail = NULL;
                        }
                        re_newbuf(sc, i, m);
                        RL_DESC_INC(i);
                        continue;
                }

                RL_DESC_INC(i);

                if (sc->rl_head != NULL) {
                        m->m_len = total_len % RE_RX_DESC_BUFLEN;
                        if (m->m_len == 0)
                                m->m_len = RE_RX_DESC_BUFLEN;
                        /*
                         * Special case: if there's 4 bytes or less
                         * in this buffer, the mbuf can be discarded:
                         * the last 4 bytes is the CRC, which we don't
                         * care about anyway.
                         */
                        if (m->m_len <= ETHER_CRC_LEN) {
                                sc->rl_tail->m_len -=
                                    (ETHER_CRC_LEN - m->m_len);
                                m_freem(m);
                        } else {
                                m->m_len -= ETHER_CRC_LEN;
                                m->m_flags &= ~M_PKTHDR;
                                sc->rl_tail->m_next = m;
                        }
                        m = sc->rl_head;
                        sc->rl_head = sc->rl_tail = NULL;
                        m->m_pkthdr.len = total_len - ETHER_CRC_LEN;
                } else
                        m->m_pkthdr.len = m->m_len =
                            (total_len - ETHER_CRC_LEN);

#ifdef RE_FIXUP_RX
                re_fixup_rx(m);
#endif
                ifp->if_ipackets++;
                m->m_pkthdr.rcvif = ifp;

                /* Do RX checksumming if enabled */

                if (ifp->if_capenable & IFCAP_RXCSUM) {

                        /* Check IP header checksum */
                        if (rxstat & RL_RDESC_STAT_PROTOID)
                                m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
                        if (!(rxstat & RL_RDESC_STAT_IPSUMBAD))
                                m->m_pkthdr.csum_flags |= CSUM_IP_VALID;

                        /* Check TCP/UDP checksum */
                        if ((RL_TCPPKT(rxstat) &&
                            !(rxstat & RL_RDESC_STAT_TCPSUMBAD)) ||
                            (RL_UDPPKT(rxstat) &&
                            !(rxstat & RL_RDESC_STAT_UDPSUMBAD))) {
                                m->m_pkthdr.csum_flags |=
                                    CSUM_DATA_VALID|CSUM_PSEUDO_HDR;
                                m->m_pkthdr.csum_data = 0xffff;
                        }
                }

                if (rxvlan & RL_RDESC_VLANCTL_TAG)
                        VLAN_INPUT_TAG(ifp, m,
                            ntohs((rxvlan & RL_RDESC_VLANCTL_DATA)), continue);
                RL_UNLOCK(sc);
                (*ifp->if_input)(ifp, m);
                RL_LOCK(sc);
        }

        /* Flush the RX DMA ring */

        bus_dmamap_sync(sc->rl_ldata.rl_rx_list_tag,
            sc->rl_ldata.rl_rx_list_map,
            BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD);

        sc->rl_ldata.rl_rx_prodidx = i;
}

static void
re_txeof(sc)
        struct rl_softc         *sc;
{
        struct ifnet            *ifp;
        u_int32_t               txstat;
        int                     idx;

        ifp = &sc->arpcom.ac_if;
        idx = sc->rl_ldata.rl_tx_considx;

        /* Invalidate the TX descriptor list */

        bus_dmamap_sync(sc->rl_ldata.rl_tx_list_tag,
            sc->rl_ldata.rl_tx_list_map,
            BUS_DMASYNC_POSTREAD);

        while (idx != sc->rl_ldata.rl_tx_prodidx) {

                txstat = le32toh(sc->rl_ldata.rl_tx_list[idx].rl_cmdstat);
                if (txstat & RL_TDESC_CMD_OWN)
                        break;

                /*
                 * We only stash mbufs in the last descriptor
                 * in a fragment chain, which also happens to
                 * be the only place where the TX status bits
                 * are valid.
                 */

                if (txstat & RL_TDESC_CMD_EOF) {
                        m_freem(sc->rl_ldata.rl_tx_mbuf[idx]);
                        sc->rl_ldata.rl_tx_mbuf[idx] = NULL;
                        bus_dmamap_unload(sc->rl_ldata.rl_mtag,
                            sc->rl_ldata.rl_tx_dmamap[idx]);
                        if (txstat & (RL_TDESC_STAT_EXCESSCOL|
                            RL_TDESC_STAT_COLCNT))
                                ifp->if_collisions++;
                        if (txstat & RL_TDESC_STAT_TXERRSUM)
                                ifp->if_oerrors++;
                        else
                                ifp->if_opackets++;
                }
                sc->rl_ldata.rl_tx_free++;
                RL_DESC_INC(idx);
        }

        /* No changes made to the TX ring, so no flush needed */

        if (idx != sc->rl_ldata.rl_tx_considx) {
                sc->rl_ldata.rl_tx_considx = idx;
                ifp->if_flags &= ~IFF_OACTIVE;
                ifp->if_timer = 0;
        }

        /*
         * If not all descriptors have been released reaped yet,
         * reload the timer so that we will eventually get another
         * interrupt that will cause us to re-enter this routine.
         * This is done in case the transmitter has gone idle.
         */
        if (sc->rl_ldata.rl_tx_free != RL_TX_DESC_CNT)
                CSR_WRITE_4(sc, RL_TIMERCNT, 1);
}

static void
re_tick(xsc)
        void                    *xsc;
{
        struct rl_softc         *sc;

        sc = xsc;
        RL_LOCK(sc);
        re_tick_locked(sc);
        RL_UNLOCK(sc);
}

static void
re_tick_locked(sc)
        struct rl_softc         *sc;
{
        struct mii_data         *mii;

        RL_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->rl_miibus);

        mii_tick(mii);

        sc->rl_stat_ch = timeout(re_tick, sc, hz);
}

#ifdef DEVICE_POLLING
static void
re_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
{
        struct rl_softc *sc = ifp->if_softc;

        RL_LOCK(sc);
        re_poll_locked(ifp, cmd, count);
        RL_UNLOCK(sc);
}

static void
re_poll_locked(struct ifnet *ifp, enum poll_cmd cmd, int count)
{
        struct rl_softc *sc = ifp->if_softc;

        RL_LOCK_ASSERT(sc);

        if (!(ifp->if_capenable & IFCAP_POLLING)) {
                ether_poll_deregister(ifp);
                cmd = POLL_DEREGISTER;
        }
        if (cmd == POLL_DEREGISTER) { /* final call, enable interrupts */
                CSR_WRITE_2(sc, RL_IMR, RL_INTRS_CPLUS);
                return;
        }

        sc->rxcycles = count;
        re_rxeof(sc);
        re_txeof(sc);

        if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
                re_start_locked(ifp);

        if (cmd == POLL_AND_CHECK_STATUS) { /* also check status register */
                u_int16_t       status;

                status = CSR_READ_2(sc, RL_ISR);
                if (status == 0xffff)
                        return;
                if (status)
                        CSR_WRITE_2(sc, RL_ISR, status);

                /*
                 * XXX check behaviour on receiver stalls.
                 */

                if (status & RL_ISR_SYSTEM_ERR) {
                        re_reset(sc);
                        re_init_locked(sc);
                }
        }
}
#endif /* DEVICE_POLLING */

static void
re_intr(arg)
        void                    *arg;
{
        struct rl_softc         *sc;
        struct ifnet            *ifp;
        u_int16_t               status;

        sc = arg;

        RL_LOCK(sc);

        ifp = &sc->arpcom.ac_if;

        if (sc->suspended || !(ifp->if_flags & IFF_UP))
                goto done_locked;

#ifdef DEVICE_POLLING
        if  (ifp->if_flags & IFF_POLLING)
                goto done_locked;
        if ((ifp->if_capenable & IFCAP_POLLING) &&
            ether_poll_register(re_poll, ifp)) { /* ok, disable interrupts */
                CSR_WRITE_2(sc, RL_IMR, 0x0000);
                re_poll_locked(ifp, 0, 1);
                goto done_locked;
        }
#endif /* DEVICE_POLLING */

        for (;;) {

                status = CSR_READ_2(sc, RL_ISR);
                /* If the card has gone away the read returns 0xffff. */
                if (status == 0xffff)
                        break;
                if (status)
                        CSR_WRITE_2(sc, RL_ISR, status);

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

                if ((status & RL_ISR_RX_OK) ||
                    (status & RL_ISR_RX_ERR))
                        re_rxeof(sc);

                if ((status & RL_ISR_TIMEOUT_EXPIRED) ||
                    (status & RL_ISR_TX_ERR) ||
                    (status & RL_ISR_TX_DESC_UNAVAIL))
                        re_txeof(sc);

                if (status & RL_ISR_SYSTEM_ERR) {
                        re_reset(sc);
                        re_init_locked(sc);
                }

                if (status & RL_ISR_LINKCHG) {
                        untimeout(re_tick, sc, sc->rl_stat_ch);
                        re_tick_locked(sc);
                }
        }

        if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
                re_start_locked(ifp);

done_locked:
        RL_UNLOCK(sc);
}

static int
re_encap(sc, m_head, idx)
        struct rl_softc         *sc;
        struct mbuf             **m_head;
        int                     *idx;
{
        struct mbuf             *m_new = NULL;
        struct rl_dmaload_arg   arg;
        bus_dmamap_t            map;
        int                     error;
        struct m_tag            *mtag;

        RL_LOCK_ASSERT(sc);

        if (sc->rl_ldata.rl_tx_free <= 4)
                return (EFBIG);

        /*
         * Set up checksum offload. Note: checksum offload bits must
         * appear in all descriptors of a multi-descriptor transmit
         * attempt. This is according to testing done with an 8169
         * chip. This is a requirement.
         */

        arg.rl_flags = 0;

        if ((*m_head)->m_pkthdr.csum_flags & CSUM_IP)
                arg.rl_flags |= RL_TDESC_CMD_IPCSUM;
        if ((*m_head)->m_pkthdr.csum_flags & CSUM_TCP)
                arg.rl_flags |= RL_TDESC_CMD_TCPCSUM;
        if ((*m_head)->m_pkthdr.csum_flags & CSUM_UDP)
                arg.rl_flags |= RL_TDESC_CMD_UDPCSUM;

        arg.sc = sc;
        arg.rl_idx = *idx;
        arg.rl_maxsegs = sc->rl_ldata.rl_tx_free;
        if (arg.rl_maxsegs > 4)
                arg.rl_maxsegs -= 4;
        arg.rl_ring = sc->rl_ldata.rl_tx_list;

        map = sc->rl_ldata.rl_tx_dmamap[*idx];
        error = bus_dmamap_load_mbuf(sc->rl_ldata.rl_mtag, map,
            *m_head, re_dma_map_desc, &arg, BUS_DMA_NOWAIT);

        if (error && error != EFBIG) {
                printf("re%d: can't map mbuf (error %d)\n", sc->rl_unit, error);
                return (ENOBUFS);
        }

        /* Too many segments to map, coalesce into a single mbuf */

        if (error || arg.rl_maxsegs == 0) {
                m_new = m_defrag(*m_head, M_DONTWAIT);
                if (m_new == NULL)
                        return (ENOBUFS);
                else
                        *m_head = m_new;

                arg.sc = sc;
                arg.rl_idx = *idx;
                arg.rl_maxsegs = sc->rl_ldata.rl_tx_free;
                arg.rl_ring = sc->rl_ldata.rl_tx_list;

                error = bus_dmamap_load_mbuf(sc->rl_ldata.rl_mtag, map,
                    *m_head, re_dma_map_desc, &arg, BUS_DMA_NOWAIT);
                if (error) {
                        printf("re%d: can't map mbuf (error %d)\n",
                            sc->rl_unit, error);
                        return (EFBIG);
                }
        }

        /*
         * Insure that the map for this transmission
         * is placed at the array index of the last descriptor
         * in this chain.  (Swap last and first dmamaps.)
         */
        sc->rl_ldata.rl_tx_dmamap[*idx] =
            sc->rl_ldata.rl_tx_dmamap[arg.rl_idx];
        sc->rl_ldata.rl_tx_dmamap[arg.rl_idx] = map;

        sc->rl_ldata.rl_tx_mbuf[arg.rl_idx] = *m_head;
        sc->rl_ldata.rl_tx_free -= arg.rl_maxsegs;

        /*
         * Set up hardware VLAN tagging. Note: vlan tag info must
         * appear in the first descriptor of a multi-descriptor
         * transmission attempt.
         */

        mtag = VLAN_OUTPUT_TAG(&sc->arpcom.ac_if, *m_head);
        if (mtag != NULL)
                sc->rl_ldata.rl_tx_list[*idx].rl_vlanctl =
                    htole32(htons(VLAN_TAG_VALUE(mtag)) | RL_TDESC_VLANCTL_TAG);

        /* Transfer ownership of packet to the chip. */

        sc->rl_ldata.rl_tx_list[arg.rl_idx].rl_cmdstat |=
            htole32(RL_TDESC_CMD_OWN);
        if (*idx != arg.rl_idx)
                sc->rl_ldata.rl_tx_list[*idx].rl_cmdstat |=
                    htole32(RL_TDESC_CMD_OWN);

        RL_DESC_INC(arg.rl_idx);
        *idx = arg.rl_idx;

        return (0);
}

static void
re_start(ifp)
        struct ifnet            *ifp;
{
        struct rl_softc         *sc;

        sc = ifp->if_softc;
        RL_LOCK(sc);
        re_start_locked(ifp);
        RL_UNLOCK(sc);
}

/*
 * Main transmit routine for C+ and gigE NICs.
 */
static void
re_start_locked(ifp)
        struct ifnet            *ifp;
{
        struct rl_softc         *sc;
        struct mbuf             *m_head = NULL;
        int                     idx, queued = 0;

        sc = ifp->if_softc;

        RL_LOCK_ASSERT(sc);

        idx = sc->rl_ldata.rl_tx_prodidx;

        while (sc->rl_ldata.rl_tx_mbuf[idx] == NULL) {
                IFQ_DRV_DEQUEUE(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                if (re_encap(sc, &m_head, &idx)) {
                        IFQ_DRV_PREPEND(&ifp->if_snd, m_head);
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                BPF_MTAP(ifp, m_head);

                queued++;
        }

        if (queued == 0)
                return;

        /* Flush the TX descriptors */

        bus_dmamap_sync(sc->rl_ldata.rl_tx_list_tag,
            sc->rl_ldata.rl_tx_list_map,
            BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD);

        sc->rl_ldata.rl_tx_prodidx = idx;

        /*
         * RealTek put the TX poll request register in a different
         * location on the 8169 gigE chip. I don't know why.
         */

        if (sc->rl_type == RL_8169)
                CSR_WRITE_2(sc, RL_GTXSTART, RL_TXSTART_START);
        else
                CSR_WRITE_2(sc, RL_TXSTART, RL_TXSTART_START);

        /*
         * Use the countdown timer for interrupt moderation.
         * 'TX done' interrupts are disabled. Instead, we reset the
         * countdown timer, which will begin counting until it hits
         * the value in the TIMERINT register, and then trigger an
         * interrupt. Each time we write to the TIMERCNT register,
         * the timer count is reset to 0.
         */
        CSR_WRITE_4(sc, RL_TIMERCNT, 1);

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

static void
re_init(xsc)
        void                    *xsc;
{
        struct rl_softc         *sc = xsc;

        RL_LOCK(sc);
        re_init_locked(sc);
        RL_UNLOCK(sc);
}

static void
re_init_locked(sc)
        struct rl_softc         *sc;
{
        struct ifnet            *ifp = &sc->arpcom.ac_if;
        struct mii_data         *mii;
        u_int32_t               rxcfg = 0;

        RL_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->rl_miibus);

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

        /*
         * Enable C+ RX and TX mode, as well as VLAN stripping and
         * RX checksum offload. We must configure the C+ register
         * before all others.
         */
        CSR_WRITE_2(sc, RL_CPLUS_CMD, RL_CPLUSCMD_RXENB|
            RL_CPLUSCMD_TXENB|RL_CPLUSCMD_PCI_MRW|
            RL_CPLUSCMD_VLANSTRIP|
            (ifp->if_capenable & IFCAP_RXCSUM ?
            RL_CPLUSCMD_RXCSUM_ENB : 0));

        /*
         * Init our MAC address.  Even though the chipset
         * documentation doesn't mention it, we need to enter "Config
         * register write enable" mode to modify the ID registers.
         */
        CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_WRITECFG);
        CSR_WRITE_STREAM_4(sc, RL_IDR0,
            *(u_int32_t *)(&sc->arpcom.ac_enaddr[0]));
        CSR_WRITE_STREAM_4(sc, RL_IDR4,
            *(u_int32_t *)(&sc->arpcom.ac_enaddr[4]));
        CSR_WRITE_1(sc, RL_EECMD, RL_EEMODE_OFF);

        /*
         * For C+ mode, initialize the RX descriptors and mbufs.
         */
        re_rx_list_init(sc);
        re_tx_list_init(sc);

        /*
         * Enable transmit and receive.
         */
        CSR_WRITE_1(sc, RL_COMMAND, RL_CMD_TX_ENB|RL_CMD_RX_ENB);

        /*
         * Set the initial TX and RX configuration.
         */
        if (sc->rl_testmode) {
                if (sc->rl_type == RL_8169)
                        CSR_WRITE_4(sc, RL_TXCFG,
                            RL_TXCFG_CONFIG|RL_LOOPTEST_ON);
                else
                        CSR_WRITE_4(sc, RL_TXCFG,
                            RL_TXCFG_CONFIG|RL_LOOPTEST_ON_CPLUS);
        } else
                CSR_WRITE_4(sc, RL_TXCFG, RL_TXCFG_CONFIG);
        CSR_WRITE_4(sc, RL_RXCFG, RL_RXCFG_CONFIG);

        /* Set the individual bit to receive frames for this host only. */
        rxcfg = CSR_READ_4(sc, RL_RXCFG);
        rxcfg |= RL_RXCFG_RX_INDIV;

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                rxcfg |= RL_RXCFG_RX_ALLPHYS;
        else
                rxcfg &= ~RL_RXCFG_RX_ALLPHYS;
        CSR_WRITE_4(sc, RL_RXCFG, rxcfg);

        /*
         * Set capture broadcast bit to capture broadcast frames.
         */
        if (ifp->if_flags & IFF_BROADCAST)
                rxcfg |= RL_RXCFG_RX_BROAD;
        else
                rxcfg &= ~RL_RXCFG_RX_BROAD;
        CSR_WRITE_4(sc, RL_RXCFG, rxcfg);

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

#ifdef DEVICE_POLLING
        /*
         * Disable interrupts if we are polling.
         */
        if (ifp->if_flags & IFF_POLLING)
                CSR_WRITE_2(sc, RL_IMR, 0);
        else    /* otherwise ... */
#endif /* DEVICE_POLLING */
        /*
         * Enable interrupts.
         */
        if (sc->rl_testmode)
                CSR_WRITE_2(sc, RL_IMR, 0);
        else
                CSR_WRITE_2(sc, RL_IMR, RL_INTRS_CPLUS);

        /* Set initial TX threshold */
        sc->rl_txthresh = RL_TX_THRESH_INIT;

        /* Start RX/TX process. */
        CSR_WRITE_4(sc, RL_MISSEDPKT, 0);
#ifdef notdef
        /* Enable receiver and transmitter. */
        CSR_WRITE_1(sc, RL_COMMAND, RL_CMD_TX_ENB|RL_CMD_RX_ENB);
#endif
        /*
         * Load the addresses of the RX and TX lists into the chip.
         */

        CSR_WRITE_4(sc, RL_RXLIST_ADDR_HI,
            RL_ADDR_HI(sc->rl_ldata.rl_rx_list_addr));
        CSR_WRITE_4(sc, RL_RXLIST_ADDR_LO,
            RL_ADDR_LO(sc->rl_ldata.rl_rx_list_addr));

        CSR_WRITE_4(sc, RL_TXLIST_ADDR_HI,
            RL_ADDR_HI(sc->rl_ldata.rl_tx_list_addr));
        CSR_WRITE_4(sc, RL_TXLIST_ADDR_LO,
            RL_ADDR_LO(sc->rl_ldata.rl_tx_list_addr));

        CSR_WRITE_1(sc, RL_EARLY_TX_THRESH, 16);

        /*
         * Initialize the timer interrupt register so that
         * a timer interrupt will be generated once the timer
         * reaches a certain number of ticks. The timer is
         * reloaded on each transmit. This gives us TX interrupt
         * moderation, which dramatically improves TX frame rate.
         */
        if (sc->rl_type == RL_8169)
                CSR_WRITE_4(sc, RL_TIMERINT_8169, 0x800);
        else
                CSR_WRITE_4(sc, RL_TIMERINT, 0x400);

        /*
         * For 8169 gigE NICs, set the max allowed RX packet
         * size so we can receive jumbo frames.
         */
        if (sc->rl_type == RL_8169)
                CSR_WRITE_2(sc, RL_MAXRXPKTLEN, 16383);

        if (sc->rl_testmode)
                return;

        mii_mediachg(mii);

        CSR_WRITE_1(sc, RL_CFG1, RL_CFG1_DRVLOAD|RL_CFG1_FULLDUPLEX);

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

        sc->rl_stat_ch = timeout(re_tick, sc, hz);
}

/*
 * Set media options.
 */
static int
re_ifmedia_upd(ifp)
        struct ifnet            *ifp;
{
        struct rl_softc         *sc;
        struct mii_data         *mii;

        sc = ifp->if_softc;
        mii = device_get_softc(sc->rl_miibus);
        mii_mediachg(mii);

        return (0);
}

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

        sc = ifp->if_softc;
        mii = device_get_softc(sc->rl_miibus);

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

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

        switch (command) {
        case SIOCSIFMTU:
                if (ifr->ifr_mtu > RL_JUMBO_MTU)
                        error = EINVAL;
                ifp->if_mtu = ifr->ifr_mtu;
                break;
        case SIOCSIFFLAGS:
                RL_LOCK(sc);
                if (ifp->if_flags & IFF_UP)
                        re_init_locked(sc);
                else if (ifp->if_flags & IFF_RUNNING)
                        re_stop(sc);
                RL_UNLOCK(sc);
                error = 0;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                RL_LOCK(sc);
                re_setmulti(sc);
                RL_UNLOCK(sc);
                error = 0;
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                mii = device_get_softc(sc->rl_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
                break;
        case SIOCSIFCAP:
                ifp->if_capenable &= ~(IFCAP_HWCSUM | IFCAP_POLLING);
                ifp->if_capenable |=
                    ifr->ifr_reqcap & (IFCAP_HWCSUM | IFCAP_POLLING);
                if (ifp->if_capenable & IFCAP_TXCSUM)
                        ifp->if_hwassist = RE_CSUM_FEATURES;
                else
                        ifp->if_hwassist = 0;
                if (ifp->if_flags & IFF_RUNNING)
                        re_init(sc);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }

        return (error);
}

static void
re_watchdog(ifp)
        struct ifnet            *ifp;
{
        struct rl_softc         *sc;

        sc = ifp->if_softc;
        RL_LOCK(sc);
        printf("re%d: watchdog timeout\n", sc->rl_unit);
        ifp->if_oerrors++;

        re_txeof(sc);
        re_rxeof(sc);
        re_init_locked(sc);

        RL_UNLOCK(sc);
}

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

        RL_LOCK_ASSERT(sc);

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

        untimeout(re_tick, sc, sc->rl_stat_ch);
        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
#ifdef DEVICE_POLLING
        ether_poll_deregister(ifp);
#endif /* DEVICE_POLLING */

        CSR_WRITE_1(sc, RL_COMMAND, 0x00);
        CSR_WRITE_2(sc, RL_IMR, 0x0000);

        if (sc->rl_head != NULL) {
                m_freem(sc->rl_head);
                sc->rl_head = sc->rl_tail = NULL;
        }

        /* Free the TX list buffers. */

        for (i = 0; i < RL_TX_DESC_CNT; i++) {
                if (sc->rl_ldata.rl_tx_mbuf[i] != NULL) {
                        bus_dmamap_unload(sc->rl_ldata.rl_mtag,
                            sc->rl_ldata.rl_tx_dmamap[i]);
                        m_freem(sc->rl_ldata.rl_tx_mbuf[i]);
                        sc->rl_ldata.rl_tx_mbuf[i] = NULL;
                }
        }

        /* Free the RX list buffers. */

        for (i = 0; i < RL_RX_DESC_CNT; i++) {
                if (sc->rl_ldata.rl_rx_mbuf[i] != NULL) {
                        bus_dmamap_unload(sc->rl_ldata.rl_mtag,
                            sc->rl_ldata.rl_rx_dmamap[i]);
                        m_freem(sc->rl_ldata.rl_rx_mbuf[i]);
                        sc->rl_ldata.rl_rx_mbuf[i] = NULL;
                }
        }
}

/*
 * Device suspend routine.  Stop the interface and save some PCI
 * settings in case the BIOS doesn't restore them properly on
 * resume.
 */
static int
re_suspend(dev)
        device_t                dev;
{
        struct rl_softc         *sc;

        sc = device_get_softc(dev);

        RL_LOCK(sc);
        re_stop(sc);
        sc->suspended = 1;
        RL_UNLOCK(sc);

        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
re_resume(dev)
        device_t                dev;
{
        struct rl_softc         *sc;
        struct ifnet            *ifp;

        sc = device_get_softc(dev);

        RL_LOCK(sc);

        ifp = &sc->arpcom.ac_if;

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

        sc->suspended = 0;
        RL_UNLOCK(sc);

        return (0);
}

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

        sc = device_get_softc(dev);

        RL_LOCK(sc);
        re_stop(sc);
        RL_UNLOCK(sc);
}