FreeBSD/Linux Kernel Cross Reference
sys/pci/if_xl.c

     /*
      * Copyright (c) 1997, 1998, 1999
      *      Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Bill Paul.
     * 4. Neither the name of the author nor the names of any co-contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
     * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     * THE POSSIBILITY OF SUCH DAMAGE.
     *
     * $FreeBSD: releng/5.0/sys/pci/if_xl.c 106936 2002-11-14 23:49:09Z sam $
     */
    
    /*
     * 3Com 3c90x Etherlink XL PCI NIC driver
     *
     * Supports the 3Com "boomerang", "cyclone" and "hurricane" PCI
     * bus-master chips (3c90x cards and embedded controllers) including
     * the following:
     *
     * 3Com 3c900-TPO       10Mbps/RJ-45
     * 3Com 3c900-COMBO     10Mbps/RJ-45,AUI,BNC
     * 3Com 3c905-TX        10/100Mbps/RJ-45
     * 3Com 3c905-T4        10/100Mbps/RJ-45
     * 3Com 3c900B-TPO      10Mbps/RJ-45
     * 3Com 3c900B-COMBO    10Mbps/RJ-45,AUI,BNC
     * 3Com 3c900B-TPC      10Mbps/RJ-45,BNC
     * 3Com 3c900B-FL       10Mbps/Fiber-optic
     * 3Com 3c905B-COMBO    10/100Mbps/RJ-45,AUI,BNC
     * 3Com 3c905B-TX       10/100Mbps/RJ-45
     * 3Com 3c905B-FL/FX    10/100Mbps/Fiber-optic
     * 3Com 3c905C-TX       10/100Mbps/RJ-45 (Tornado ASIC)
     * 3Com 3c980-TX        10/100Mbps server adapter (Hurricane ASIC)
     * 3Com 3c980C-TX       10/100Mbps server adapter (Tornado ASIC)
     * 3Com 3cSOHO100-TX    10/100Mbps/RJ-45 (Hurricane ASIC)
     * 3Com 3c450-TX        10/100Mbps/RJ-45 (Tornado ASIC)
     * 3Com 3c556           10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
     * 3Com 3c556B          10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
     * 3Com 3c575TX         10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
     * 3Com 3c575B          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
     * 3Com 3c575C          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
     * 3Com 3cxfem656       10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
     * 3Com 3cxfem656b      10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
     * 3Com 3cxfem656c      10/100Mbps/RJ-45 (Cardbus, Tornado ASIC)
     * Dell Optiplex GX1 on-board 3c918 10/100Mbps/RJ-45
     * Dell on-board 3c920 10/100Mbps/RJ-45
     * Dell Precision on-board 3c905B 10/100Mbps/RJ-45
     * Dell Latitude laptop docking station embedded 3c905-TX
     *
     * Written by Bill Paul <wpaul@ctr.columbia.edu>
     * Electrical Engineering Department
     * Columbia University, New York City
     */
    
    /*
     * The 3c90x series chips use a bus-master DMA interface for transfering
     * packets to and from the controller chip. Some of the "vortex" cards
     * (3c59x) also supported a bus master mode, however for those chips
     * you could only DMA packets to/from a contiguous memory buffer. For
     * transmission this would mean copying the contents of the queued mbuf
     * chain into a an mbuf cluster and then DMAing the cluster. This extra
     * copy would sort of defeat the purpose of the bus master support for
     * any packet that doesn't fit into a single mbuf.
     *
     * By contrast, the 3c90x cards support a fragment-based bus master
     * mode where mbuf chains can be encapsulated using TX descriptors.
     * This is similar to other PCI chips such as the Texas Instruments
     * ThunderLAN and the Intel 82557/82558.
     *
     * The "vortex" driver (if_vx.c) happens to work for the "boomerang"
     * bus master chips because they maintain the old PIO interface for
     * backwards compatibility, but starting with the 3c905B and the
     * "cyclone" chips, the compatibility interface has been dropped.
     * Since using bus master DMA is a big win, we use this driver to
     * support the PCI "boomerang" chips even though they work with the
     * "vortex" driver in order to obtain better performance.
     *
     * This driver is in the /sys/pci directory because it only supports
    * PCI-based NICs.
    */
   
   #include <sys/param.h>
   #include <sys/systm.h>
   #include <sys/sockio.h>
   #include <sys/mbuf.h>
   #include <sys/malloc.h>
   #include <sys/kernel.h>
   #include <sys/socket.h>
   
   #include <net/if.h>
   #include <net/if_arp.h>
   #include <net/ethernet.h>
   #include <net/if_dl.h>
   #include <net/if_media.h>
   
   #include <net/bpf.h>
   
   #include <vm/vm.h>              /* for vtophys */
   #include <vm/pmap.h>            /* for vtophys */
   #include <machine/bus_memio.h>
   #include <machine/bus_pio.h>
   #include <machine/bus.h>
   #include <machine/resource.h>
   #include <sys/bus.h>
   #include <sys/rman.h>
   
   #include <dev/mii/mii.h>
   #include <dev/mii/miivar.h>
   
   #include <pci/pcireg.h>
   #include <pci/pcivar.h>
   
   MODULE_DEPEND(xl, miibus, 1, 1, 1);
   
   /* "controller miibus0" required.  See GENERIC if you get errors here. */
   #include "miibus_if.h"
   
   /*
    * The following #define causes the code to use PIO to access the
    * chip's registers instead of memory mapped mode. The reason PIO mode
    * is on by default is that the Etherlink XL manual seems to indicate
    * that only the newer revision chips (3c905B) support both PIO and
    * memory mapped access. Since we want to be compatible with the older
    * bus master chips, we use PIO here. If you comment this out, the
    * driver will use memory mapped I/O, which may be faster but which
    * might not work on some devices.
    */
   #define XL_USEIOSPACE
   
   #include <pci/if_xlreg.h>
   
   #if !defined(lint)
   static const char rcsid[] =
     "$FreeBSD: releng/5.0/sys/pci/if_xl.c 106936 2002-11-14 23:49:09Z sam $";
   #endif
   
   #define XL905B_CSUM_FEATURES    (CSUM_IP | CSUM_TCP | CSUM_UDP)
   
   /*
    * Various supported device vendors/types and their names.
    */
   static struct xl_type xl_devs[] = {
           { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT,
                   "3Com 3c900-TPO Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT_COMBO,
                   "3Com 3c900-COMBO Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_BOOMERANG_10_100BT,
                   "3Com 3c905-TX Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_BOOMERANG_100BT4,
                   "3Com 3c905-T4 Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT,
                   "3Com 3c900B-TPO Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_COMBO,
                   "3Com 3c900B-COMBO Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_TPC,
                   "3Com 3c900B-TPC Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_CYCLONE_10FL,
                   "3Com 3c900B-FL Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT,
                   "3Com 3c905B-TX Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100BT4,
                   "3Com 3c905B-T4 Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100FX,
                   "3Com 3c905B-FX/SC Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100_COMBO,
                   "3Com 3c905B-COMBO Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT,
                   "3Com 3c905C-TX Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT_SERV,
                   "3Com 3c980 Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_SERV,
                   "3Com 3c980C Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_SOHO100TX,
                   "3Com 3cSOHO100-TX OfficeConnect" },
           { TC_VENDORID, TC_DEVICEID_TORNADO_HOMECONNECT,
                   "3Com 3c450-TX HomeConnect" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_556,
                   "3Com 3c556 Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_556B,
                   "3Com 3c556B Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_575A,
                   "3Com 3c575TX Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_575B,
                   "3Com 3c575B Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_575C,
                   "3Com 3c575C Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_656,
                   "3Com 3c656 Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_HURRICANE_656B,
                   "3Com 3c656B Fast Etherlink XL" },
           { TC_VENDORID, TC_DEVICEID_TORNADO_656C,
                   "3Com 3c656C Fast Etherlink XL" },
           { 0, 0, NULL }
   };
   
   static int xl_probe             (device_t);
   static int xl_attach            (device_t);
   static int xl_detach            (device_t);
   
   static int xl_newbuf            (struct xl_softc *, struct xl_chain_onefrag *);
   static void xl_stats_update     (void *);
   static int xl_encap             (struct xl_softc *, struct xl_chain *,
                                                   struct mbuf *);
   static int xl_encap_90xB        (struct xl_softc *, struct xl_chain *,
                                                   struct mbuf *);
   
   static void xl_rxeof            (struct xl_softc *);
   static int xl_rx_resync         (struct xl_softc *);
   static void xl_txeof            (struct xl_softc *);
   static void xl_txeof_90xB       (struct xl_softc *);
   static void xl_txeoc            (struct xl_softc *);
   static void xl_intr             (void *);
   static void xl_start            (struct ifnet *);
   static void xl_start_90xB       (struct ifnet *);
   static int xl_ioctl             (struct ifnet *, u_long, caddr_t);
   static void xl_init             (void *);
   static void xl_stop             (struct xl_softc *);
   static void xl_watchdog         (struct ifnet *);
   static void xl_shutdown         (device_t);
   static int xl_suspend           (device_t); 
   static int xl_resume            (device_t);
   
   static int xl_ifmedia_upd       (struct ifnet *);
   static void xl_ifmedia_sts      (struct ifnet *, struct ifmediareq *);
   
   static int xl_eeprom_wait       (struct xl_softc *);
   static int xl_read_eeprom       (struct xl_softc *, caddr_t, int, int, int);
   static void xl_mii_sync         (struct xl_softc *);
   static void xl_mii_send         (struct xl_softc *, u_int32_t, int);
   static int xl_mii_readreg       (struct xl_softc *, struct xl_mii_frame *);
   static int xl_mii_writereg      (struct xl_softc *, struct xl_mii_frame *);
   
   static void xl_setcfg           (struct xl_softc *);
   static void xl_setmode          (struct xl_softc *, int);
   static u_int8_t xl_calchash     (caddr_t);
   static void xl_setmulti         (struct xl_softc *);
   static void xl_setmulti_hash    (struct xl_softc *);
   static void xl_reset            (struct xl_softc *);
   static int xl_list_rx_init      (struct xl_softc *);
   static int xl_list_tx_init      (struct xl_softc *);
   static int xl_list_tx_init_90xB (struct xl_softc *);
   static void xl_wait             (struct xl_softc *);
   static void xl_mediacheck       (struct xl_softc *);
   static void xl_choose_xcvr      (struct xl_softc *, int);
   #ifdef notdef
   static void xl_testpacket       (struct xl_softc *);
   #endif
   
   static int xl_miibus_readreg    (device_t, int, int);
   static int xl_miibus_writereg   (device_t, int, int, int);
   static void xl_miibus_statchg   (device_t);
   static void xl_miibus_mediainit (device_t);
   
   #ifdef XL_USEIOSPACE
   #define XL_RES                  SYS_RES_IOPORT
   #define XL_RID                  XL_PCI_LOIO
   #else
   #define XL_RES                  SYS_RES_MEMORY
   #define XL_RID                  XL_PCI_LOMEM
   #endif
   
   static device_method_t xl_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,         xl_probe),
           DEVMETHOD(device_attach,        xl_attach),
           DEVMETHOD(device_detach,        xl_detach),
           DEVMETHOD(device_shutdown,      xl_shutdown),
           DEVMETHOD(device_suspend,       xl_suspend),
           DEVMETHOD(device_resume,        xl_resume),
   
           /* bus interface */
           DEVMETHOD(bus_print_child,      bus_generic_print_child),
           DEVMETHOD(bus_driver_added,     bus_generic_driver_added),
   
           /* MII interface */
           DEVMETHOD(miibus_readreg,       xl_miibus_readreg),
           DEVMETHOD(miibus_writereg,      xl_miibus_writereg),
           DEVMETHOD(miibus_statchg,       xl_miibus_statchg),
           DEVMETHOD(miibus_mediainit,     xl_miibus_mediainit),
   
           { 0, 0 }
   };
   
   static driver_t xl_driver = {
           "xl",
           xl_methods,
           sizeof(struct xl_softc)
   };
   
   static devclass_t xl_devclass;
   
   DRIVER_MODULE(if_xl, cardbus, xl_driver, xl_devclass, 0, 0);
   DRIVER_MODULE(if_xl, pci, xl_driver, xl_devclass, 0, 0);
   DRIVER_MODULE(miibus, xl, miibus_driver, miibus_devclass, 0, 0);
   
   /*
    * Murphy's law says that it's possible the chip can wedge and
    * the 'command in progress' bit may never clear. Hence, we wait
    * only a finite amount of time to avoid getting caught in an
    * infinite loop. Normally this delay routine would be a macro,
    * but it isn't called during normal operation so we can afford
    * to make it a function.
    */
   static void
   xl_wait(sc)
           struct xl_softc         *sc;
   {
           register int            i;
   
           for (i = 0; i < XL_TIMEOUT; i++) {
                   if (!(CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY))
                           break;
           }
   
           if (i == XL_TIMEOUT)
                   printf("xl%d: command never completed!\n", sc->xl_unit);
   
           return;
   }
   
   /*
    * MII access routines are provided for adapters with external
    * PHYs (3c905-TX, 3c905-T4, 3c905B-T4) and those with built-in
    * autoneg logic that's faked up to look like a PHY (3c905B-TX).
    * Note: if you don't perform the MDIO operations just right,
    * it's possible to end up with code that works correctly with
    * some chips/CPUs/processor speeds/bus speeds/etc but not
    * with others.
    */
   #define MII_SET(x)                                      \
           CSR_WRITE_2(sc, XL_W4_PHY_MGMT,                 \
                   CSR_READ_2(sc, XL_W4_PHY_MGMT) | (x))
   
   #define MII_CLR(x)                                      \
           CSR_WRITE_2(sc, XL_W4_PHY_MGMT,                 \
                   CSR_READ_2(sc, XL_W4_PHY_MGMT) & ~(x))
   
   /*
    * Sync the PHYs by setting data bit and strobing the clock 32 times.
    */
   static void
   xl_mii_sync(sc)
           struct xl_softc         *sc;
   {
           register int            i;
   
           XL_SEL_WIN(4);
           MII_SET(XL_MII_DIR|XL_MII_DATA);
   
           for (i = 0; i < 32; i++) {
                   MII_SET(XL_MII_CLK);
                   MII_CLR(XL_MII_CLK);
           }
   
           return;
   }
   
   /*
    * Clock a series of bits through the MII.
    */
   static void
   xl_mii_send(sc, bits, cnt)
           struct xl_softc         *sc;
           u_int32_t               bits;
           int                     cnt;
   {
           int                     i;
   
           XL_SEL_WIN(4);
           MII_CLR(XL_MII_CLK);
   
           for (i = (0x1 << (cnt - 1)); i; i >>= 1) {
                   if (bits & i) {
                           MII_SET(XL_MII_DATA);
                   } else {
                           MII_CLR(XL_MII_DATA);
                   }
                   MII_CLR(XL_MII_CLK);
                   MII_SET(XL_MII_CLK);
           }
   }
   
   /*
    * Read an PHY register through the MII.
    */
   static int
   xl_mii_readreg(sc, frame)
           struct xl_softc         *sc;
           struct xl_mii_frame     *frame;
           
   {
           int                     i, ack;
   
           XL_LOCK(sc);
   
           /*
            * Set up frame for RX.
            */
           frame->mii_stdelim = XL_MII_STARTDELIM;
           frame->mii_opcode = XL_MII_READOP;
           frame->mii_turnaround = 0;
           frame->mii_data = 0;
           
           /*
            * Select register window 4.
            */
   
           XL_SEL_WIN(4);
   
           CSR_WRITE_2(sc, XL_W4_PHY_MGMT, 0);
           /*
            * Turn on data xmit.
            */
           MII_SET(XL_MII_DIR);
   
           xl_mii_sync(sc);
   
           /*
            * Send command/address info.
            */
           xl_mii_send(sc, frame->mii_stdelim, 2);
           xl_mii_send(sc, frame->mii_opcode, 2);
           xl_mii_send(sc, frame->mii_phyaddr, 5);
           xl_mii_send(sc, frame->mii_regaddr, 5);
   
           /* Idle bit */
           MII_CLR((XL_MII_CLK|XL_MII_DATA));
           MII_SET(XL_MII_CLK);
   
           /* Turn off xmit. */
           MII_CLR(XL_MII_DIR);
   
           /* Check for ack */
           MII_CLR(XL_MII_CLK);
           MII_SET(XL_MII_CLK);
           ack = CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA;
   
           /*
            * Now try reading data bits. If the ack failed, we still
            * need to clock through 16 cycles to keep the PHY(s) in sync.
            */
           if (ack) {
                   for(i = 0; i < 16; i++) {
                           MII_CLR(XL_MII_CLK);
                           MII_SET(XL_MII_CLK);
                   }
                   goto fail;
           }
   
           for (i = 0x8000; i; i >>= 1) {
                   MII_CLR(XL_MII_CLK);
                   if (!ack) {
                           if (CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA)
                                   frame->mii_data |= i;
                   }
                   MII_SET(XL_MII_CLK);
           }
   
   fail:
   
           MII_CLR(XL_MII_CLK);
           MII_SET(XL_MII_CLK);
   
           XL_UNLOCK(sc);
   
           if (ack)
                   return(1);
           return(0);
   }
   
   /*
    * Write to a PHY register through the MII.
    */
   static int
   xl_mii_writereg(sc, frame)
           struct xl_softc         *sc;
           struct xl_mii_frame     *frame;
           
   {
           XL_LOCK(sc);
   
           /*
            * Set up frame for TX.
            */
   
           frame->mii_stdelim = XL_MII_STARTDELIM;
           frame->mii_opcode = XL_MII_WRITEOP;
           frame->mii_turnaround = XL_MII_TURNAROUND;
           
           /*
            * Select the window 4.
            */
           XL_SEL_WIN(4);
   
           /*
            * Turn on data output.
            */
           MII_SET(XL_MII_DIR);
   
           xl_mii_sync(sc);
   
           xl_mii_send(sc, frame->mii_stdelim, 2);
           xl_mii_send(sc, frame->mii_opcode, 2);
           xl_mii_send(sc, frame->mii_phyaddr, 5);
           xl_mii_send(sc, frame->mii_regaddr, 5);
           xl_mii_send(sc, frame->mii_turnaround, 2);
           xl_mii_send(sc, frame->mii_data, 16);
   
           /* Idle bit. */
           MII_SET(XL_MII_CLK);
           MII_CLR(XL_MII_CLK);
   
           /*
            * Turn off xmit.
            */
           MII_CLR(XL_MII_DIR);
   
           XL_UNLOCK(sc);
   
           return(0);
   }
   
   static int
   xl_miibus_readreg(dev, phy, reg)
           device_t                dev;
           int                     phy, reg;
   {
           struct xl_softc         *sc;
           struct xl_mii_frame     frame;
   
           sc = device_get_softc(dev);
   
           /*
            * Pretend that PHYs are only available at MII address 24.
            * This is to guard against problems with certain 3Com ASIC
            * revisions that incorrectly map the internal transceiver
            * control registers at all MII addresses. This can cause
            * the miibus code to attach the same PHY several times over.
            */
           if ((!(sc->xl_flags & XL_FLAG_PHYOK)) && phy != 24)
                   return(0);
   
           bzero((char *)&frame, sizeof(frame));
   
           frame.mii_phyaddr = phy;
           frame.mii_regaddr = reg;
           xl_mii_readreg(sc, &frame);
   
           return(frame.mii_data);
   }
   
   static int
   xl_miibus_writereg(dev, phy, reg, data)
           device_t                dev;
           int                     phy, reg, data;
   {
           struct xl_softc         *sc;
           struct xl_mii_frame     frame;
   
           sc = device_get_softc(dev);
   
           if ((!(sc->xl_flags & XL_FLAG_PHYOK)) && phy != 24)
                   return(0);
   
           bzero((char *)&frame, sizeof(frame));
   
           frame.mii_phyaddr = phy;
           frame.mii_regaddr = reg;
           frame.mii_data = data;
   
           xl_mii_writereg(sc, &frame);
   
           return(0);
   }
   
   static void
   xl_miibus_statchg(dev)
           device_t                dev;
   {
           struct xl_softc         *sc;
           struct mii_data         *mii;
   
           
           sc = device_get_softc(dev);
           mii = device_get_softc(sc->xl_miibus);
   
           XL_LOCK(sc);
   
           xl_setcfg(sc);
   
           /* Set ASIC's duplex mode to match the PHY. */
           XL_SEL_WIN(3);
           if ((mii->mii_media_active & IFM_GMASK) == IFM_FDX)
                   CSR_WRITE_1(sc, XL_W3_MAC_CTRL, XL_MACCTRL_DUPLEX);
           else
                   CSR_WRITE_1(sc, XL_W3_MAC_CTRL,
                           (CSR_READ_1(sc, XL_W3_MAC_CTRL) & ~XL_MACCTRL_DUPLEX));
   
           XL_UNLOCK(sc);
   
           return;
   }
   
   /*
    * Special support for the 3c905B-COMBO. This card has 10/100 support
    * plus BNC and AUI ports. This means we will have both an miibus attached
    * plus some non-MII media settings. In order to allow this, we have to
    * add the extra media to the miibus's ifmedia struct, but we can't do
    * that during xl_attach() because the miibus hasn't been attached yet.
    * So instead, we wait until the miibus probe/attach is done, at which
    * point we will get a callback telling is that it's safe to add our
    * extra media.
    */
   static void
   xl_miibus_mediainit(dev)
           device_t                dev;
   {
           struct xl_softc         *sc;
           struct mii_data         *mii;
           struct ifmedia          *ifm;
           
           sc = device_get_softc(dev);
           mii = device_get_softc(sc->xl_miibus);
           ifm = &mii->mii_media;
   
           XL_LOCK(sc);
   
           if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                   /*
                    * Check for a 10baseFL board in disguise.
                    */
                   if (sc->xl_type == XL_TYPE_905B &&
                       sc->xl_media == XL_MEDIAOPT_10FL) {
                           if (bootverbose)
                                   printf("xl%d: found 10baseFL\n", sc->xl_unit);
                           ifmedia_add(ifm, IFM_ETHER|IFM_10_FL, 0, NULL);
                           ifmedia_add(ifm, IFM_ETHER|IFM_10_FL|IFM_HDX, 0, NULL);
                           if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                   ifmedia_add(ifm,
                                       IFM_ETHER|IFM_10_FL|IFM_FDX, 0, NULL);
                   } else {
                           if (bootverbose)
                                   printf("xl%d: found AUI\n", sc->xl_unit);
                           ifmedia_add(ifm, IFM_ETHER|IFM_10_5, 0, NULL);
                   }
           }
   
           if (sc->xl_media & XL_MEDIAOPT_BNC) {
                   if (bootverbose)
                           printf("xl%d: found BNC\n", sc->xl_unit);
                   ifmedia_add(ifm, IFM_ETHER|IFM_10_2, 0, NULL);
           }
   
           XL_UNLOCK(sc);
   
           return;
   }
   
   /*
    * The EEPROM is slow: give it time to come ready after issuing
    * it a command.
    */
   static int
   xl_eeprom_wait(sc)
           struct xl_softc         *sc;
   {
           int                     i;
   
           for (i = 0; i < 100; i++) {
                   if (CSR_READ_2(sc, XL_W0_EE_CMD) & XL_EE_BUSY)
                           DELAY(162);
                   else
                           break;
           }
   
           if (i == 100) {
                   printf("xl%d: eeprom failed to come ready\n", sc->xl_unit);
                   return(1);
           }
   
           return(0);
   }
   
   /*
    * Read a sequence of words from the EEPROM. Note that ethernet address
    * data is stored in the EEPROM in network byte order.
    */
   static int
   xl_read_eeprom(sc, dest, off, cnt, swap)
           struct xl_softc         *sc;
           caddr_t                 dest;
           int                     off;
           int                     cnt;
           int                     swap;
   {
           int                     err = 0, i;
           u_int16_t               word = 0, *ptr;
   #define EEPROM_5BIT_OFFSET(A) ((((A) << 2) & 0x7F00) | ((A) & 0x003F))
   #define EEPROM_8BIT_OFFSET(A) ((A) & 0x003F)
           /* WARNING! DANGER!
            * It's easy to accidentally overwrite the rom content!
            * Note: the 3c575 uses 8bit EEPROM offsets.
            */
           XL_SEL_WIN(0);
   
           if (xl_eeprom_wait(sc))
                   return(1);
   
           if (sc->xl_flags & XL_FLAG_EEPROM_OFFSET_30)
                   off += 0x30;
   
           for (i = 0; i < cnt; i++) {
                   if (sc->xl_flags & XL_FLAG_8BITROM)
                           CSR_WRITE_2(sc, XL_W0_EE_CMD, 
                               XL_EE_8BIT_READ | EEPROM_8BIT_OFFSET(off + i));
                   else
                           CSR_WRITE_2(sc, XL_W0_EE_CMD,
                               XL_EE_READ | EEPROM_5BIT_OFFSET(off + i));
                   err = xl_eeprom_wait(sc);
                   if (err)
                           break;
                   word = CSR_READ_2(sc, XL_W0_EE_DATA);
                   ptr = (u_int16_t *)(dest + (i * 2));
                   if (swap)
                           *ptr = ntohs(word);
                   else
                           *ptr = word;    
           }
   
           return(err ? 1 : 0);
   }
   
   /*
    * This routine is taken from the 3Com Etherlink XL manual,
    * page 10-7. It calculates a CRC of the supplied multicast
    * group address and returns the lower 8 bits, which are used
    * as the multicast filter position.
    * Note: the 3c905B currently only supports a 64-bit hash table,
    * which means we really only need 6 bits, but the manual indicates
    * that future chip revisions will have a 256-bit hash table,
    * hence the routine is set up to calculate 8 bits of position
    * info in case we need it some day.
    * Note II, The Sequel: _CURRENT_ versions of the 3c905B have a
    * 256 bit hash table. This means we have to use all 8 bits regardless.
    * On older cards, the upper 2 bits will be ignored. Grrrr....
    */
   static u_int8_t xl_calchash(addr)
           caddr_t                 addr;
   {
           u_int32_t               crc, carry;
           int                     i, j;
           u_int8_t                c;
   
           /* Compute CRC for the address value. */
           crc = 0xFFFFFFFF; /* initial value */
   
           for (i = 0; i < 6; i++) {
                   c = *(addr + i);
                   for (j = 0; j < 8; j++) {
                           carry = ((crc & 0x80000000) ? 1 : 0) ^ (c & 0x01);
                           crc <<= 1;
                           c >>= 1;
                           if (carry)
                                   crc = (crc ^ 0x04c11db6) | carry;
                   }
           }
   
           /* return the filter bit position */
           return(crc & 0x000000FF);
   }
   
   /*
    * NICs older than the 3c905B have only one multicast option, which
    * is to enable reception of all multicast frames.
    */
   static void
   xl_setmulti(sc)
           struct xl_softc         *sc;
   {
           struct ifnet            *ifp;
           struct ifmultiaddr      *ifma;
           u_int8_t                rxfilt;
           int                     mcnt = 0;
   
           ifp = &sc->arpcom.ac_if;
   
           XL_SEL_WIN(5);
           rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
   
           if (ifp->if_flags & IFF_ALLMULTI) {
                   rxfilt |= XL_RXFILTER_ALLMULTI;
                   CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
                   return;
           }
   
           TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
                   mcnt++;
   
           if (mcnt)
                   rxfilt |= XL_RXFILTER_ALLMULTI;
           else
                   rxfilt &= ~XL_RXFILTER_ALLMULTI;
   
           CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
   
           return;
   }
   
   /*
    * 3c905B adapters have a hash filter that we can program.
    */
   static void
   xl_setmulti_hash(sc)
           struct xl_softc         *sc;
   {
           struct ifnet            *ifp;
           int                     h = 0, i;
           struct ifmultiaddr      *ifma;
           u_int8_t                rxfilt;
           int                     mcnt = 0;
   
           ifp = &sc->arpcom.ac_if;
   
           XL_SEL_WIN(5);
           rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
   
           if (ifp->if_flags & IFF_ALLMULTI) {
                   rxfilt |= XL_RXFILTER_ALLMULTI;
                   CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
                   return;
           } else
                   rxfilt &= ~XL_RXFILTER_ALLMULTI;
   
   
           /* first, zot all the existing hash bits */
           for (i = 0; i < XL_HASHFILT_SIZE; i++)
                   CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH|i);
   
           /* now program new ones */
           TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                   if (ifma->ifma_addr->sa_family != AF_LINK)
                           continue;
                   h = xl_calchash(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                   CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH|XL_HASH_SET|h);
                   mcnt++;
           }
   
           if (mcnt)
                   rxfilt |= XL_RXFILTER_MULTIHASH;
           else
                   rxfilt &= ~XL_RXFILTER_MULTIHASH;
   
           CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
   
           return;
   }
   
   #ifdef notdef
   static void
   xl_testpacket(sc)
           struct xl_softc         *sc;
   {
           struct mbuf             *m;
           struct ifnet            *ifp;
   
           ifp = &sc->arpcom.ac_if;
   
           MGETHDR(m, M_DONTWAIT, MT_DATA);
   
           if (m == NULL)
                   return;
   
           bcopy(&sc->arpcom.ac_enaddr,
                   mtod(m, struct ether_header *)->ether_dhost, ETHER_ADDR_LEN);
           bcopy(&sc->arpcom.ac_enaddr,
                   mtod(m, struct ether_header *)->ether_shost, ETHER_ADDR_LEN);
           mtod(m, struct ether_header *)->ether_type = htons(3);
           mtod(m, unsigned char *)[14] = 0;
           mtod(m, unsigned char *)[15] = 0;
           mtod(m, unsigned char *)[16] = 0xE3;
           m->m_len = m->m_pkthdr.len = sizeof(struct ether_header) + 3;
           IF_ENQUEUE(&ifp->if_snd, m);
           xl_start(ifp);
   
           return;
   }
   #endif
   
   static void
   xl_setcfg(sc)
           struct xl_softc         *sc;
   {
           u_int32_t               icfg;
   
           XL_SEL_WIN(3);
           icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);
           icfg &= ~XL_ICFG_CONNECTOR_MASK;
           if (sc->xl_media & XL_MEDIAOPT_MII ||
                   sc->xl_media & XL_MEDIAOPT_BT4)
                   icfg |= (XL_XCVR_MII << XL_ICFG_CONNECTOR_BITS);
           if (sc->xl_media & XL_MEDIAOPT_BTX)
                   icfg |= (XL_XCVR_AUTO << XL_ICFG_CONNECTOR_BITS);
   
           CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
           CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
   
           return;
   }
   
   static void
   xl_setmode(sc, media)
           struct xl_softc         *sc;
           int                     media;
   {
           u_int32_t               icfg;
           u_int16_t               mediastat;
   
           printf("xl%d: selecting ", sc->xl_unit);
   
           XL_SEL_WIN(4);
           mediastat = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
           XL_SEL_WIN(3);
           icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);
   
           if (sc->xl_media & XL_MEDIAOPT_BT) {
                   if (IFM_SUBTYPE(media) == IFM_10_T) {
                           printf("10baseT transceiver, ");
                           sc->xl_xcvr = XL_XCVR_10BT;
                           icfg &= ~XL_ICFG_CONNECTOR_MASK;
                           icfg |= (XL_XCVR_10BT << XL_ICFG_CONNECTOR_BITS);
                           mediastat |= XL_MEDIASTAT_LINKBEAT|
                                           XL_MEDIASTAT_JABGUARD;
                           mediastat &= ~XL_MEDIASTAT_SQEENB;
                   }
           }
   
           if (sc->xl_media & XL_MEDIAOPT_BFX) {
                   if (IFM_SUBTYPE(media) == IFM_100_FX) {
                           printf("100baseFX port, ");
                           sc->xl_xcvr = XL_XCVR_100BFX;
                           icfg &= ~XL_ICFG_CONNECTOR_MASK;
                           icfg |= (XL_XCVR_100BFX << XL_ICFG_CONNECTOR_BITS);
                           mediastat |= XL_MEDIASTAT_LINKBEAT;
                           mediastat &= ~XL_MEDIASTAT_SQEENB;
                   }
           }
   
           if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                   if (IFM_SUBTYPE(media) == IFM_10_5) {
                           printf("AUI port, ");
                           sc->xl_xcvr = XL_XCVR_AUI;
                           icfg &= ~XL_ICFG_CONNECTOR_MASK;
                           icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                           mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                           XL_MEDIASTAT_JABGUARD);
                           mediastat |= ~XL_MEDIASTAT_SQEENB;
                   }
                   if (IFM_SUBTYPE(media) == IFM_10_FL) {
                           printf("10baseFL transceiver, ");
                           sc->xl_xcvr = XL_XCVR_AUI;
                           icfg &= ~XL_ICFG_CONNECTOR_MASK;
                           icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                           mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                           XL_MEDIASTAT_JABGUARD);
                           mediastat |= ~XL_MEDIASTAT_SQEENB;
                   }
           }
   
           if (sc->xl_media & XL_MEDIAOPT_BNC) {
                   if (IFM_SUBTYPE(media) == IFM_10_2) {
                           printf("BNC port, ");
                           sc->xl_xcvr = XL_XCVR_COAX;
                           icfg &= ~XL_ICFG_CONNECTOR_MASK;
                           icfg |= (XL_XCVR_COAX << XL_ICFG_CONNECTOR_BITS);
                           mediastat &= ~(XL_MEDIASTAT_LINKBEAT|
                                           XL_MEDIASTAT_JABGUARD|
                                           XL_MEDIASTAT_SQEENB);
                   }
          }
  
          if ((media & IFM_GMASK) == IFM_FDX ||
                          IFM_SUBTYPE(media) == IFM_100_FX) {
                  printf("full duplex\n");
                  XL_SEL_WIN(3);
                  CSR_WRITE_1(sc, XL_W3_MAC_CTRL, XL_MACCTRL_DUPLEX);
          } else {
                  printf("half duplex\n");
                  XL_SEL_WIN(3);
                  CSR_WRITE_1(sc, XL_W3_MAC_CTRL,
                          (CSR_READ_1(sc, XL_W3_MAC_CTRL) & ~XL_MACCTRL_DUPLEX));
          }
  
          if (IFM_SUBTYPE(media) == IFM_10_2)
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
          else
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
          CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
          XL_SEL_WIN(4);
          CSR_WRITE_2(sc, XL_W4_MEDIA_STATUS, mediastat);
          DELAY(800);
          XL_SEL_WIN(7);
  
          return;
  }
  
  static void
  xl_reset(sc)
          struct xl_softc         *sc;
  {
          register int            i;
  
          XL_SEL_WIN(0);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RESET | 
                      ((sc->xl_flags & XL_FLAG_WEIRDRESET) ?
                       XL_RESETOPT_DISADVFD:0));
  
          for (i = 0; i < XL_TIMEOUT; i++) {
                  DELAY(10);
                  if (!(CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY))
                          break;
          }
  
          if (i == XL_TIMEOUT)
                  printf("xl%d: reset didn't complete\n", sc->xl_unit);
  
          /* Reset TX and RX. */
          /* Note: the RX reset takes an absurd amount of time
           * on newer versions of the Tornado chips such as those
           * on the 3c905CX and newer 3c908C cards. We wait an
           * extra amount of time so that xl_wait() doesn't complain
           * and annoy the users.
           */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
          DELAY(100000);
          xl_wait(sc);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
          xl_wait(sc);
  
          if (sc->xl_flags & XL_FLAG_INVERT_LED_PWR || 
              sc->xl_flags & XL_FLAG_INVERT_MII_PWR) {
                  XL_SEL_WIN(2);
                  CSR_WRITE_2(sc, XL_W2_RESET_OPTIONS, CSR_READ_2(sc,
                      XL_W2_RESET_OPTIONS) 
                      | ((sc->xl_flags & XL_FLAG_INVERT_LED_PWR)?XL_RESETOPT_INVERT_LED:0)
                      | ((sc->xl_flags & XL_FLAG_INVERT_MII_PWR)?XL_RESETOPT_INVERT_MII:0)
                      );
          }
  
          /* Wait a little while for the chip to get its brains in order. */
          DELAY(100000);
          return;
  }
  
  /*
   * Probe for a 3Com Etherlink XL chip. Check the PCI vendor and device
   * IDs against our list and return a device name if we find a match.
   */
  static int
  xl_probe(dev)
          device_t                dev;
  {
          struct xl_type          *t;
  
          t = xl_devs;
  
          while(t->xl_name != NULL) {
                  if ((pci_get_vendor(dev) == t->xl_vid) &&
                      (pci_get_device(dev) == t->xl_did)) {
                          device_set_desc(dev, t->xl_name);
                          return(0);
                  }
                  t++;
          }
  
          return(ENXIO);
  }
  
  /*
   * This routine is a kludge to work around possible hardware faults
   * or manufacturing defects that can cause the media options register
   * (or reset options register, as it's called for the first generation
   * 3c90x adapters) to return an incorrect result. I have encountered
   * one Dell Latitude laptop docking station with an integrated 3c905-TX
   * which doesn't have any of the 'mediaopt' bits set. This screws up
   * the attach routine pretty badly because it doesn't know what media
   * to look for. If we find ourselves in this predicament, this routine
   * will try to guess the media options values and warn the user of a
   * possible manufacturing defect with his adapter/system/whatever.
   */
  static void
  xl_mediacheck(sc)
          struct xl_softc         *sc;
  {
  
          /*
           * If some of the media options bits are set, assume they are
           * correct. If not, try to figure it out down below.
           * XXX I should check for 10baseFL, but I don't have an adapter
           * to test with.
           */
          if (sc->xl_media & (XL_MEDIAOPT_MASK & ~XL_MEDIAOPT_VCO)) {
                  /*
                   * Check the XCVR value. If it's not in the normal range
                   * of values, we need to fake it up here.
                   */
                  if (sc->xl_xcvr <= XL_XCVR_AUTO)
                          return;
                  else {
                          printf("xl%d: bogus xcvr value "
                          "in EEPROM (%x)\n", sc->xl_unit, sc->xl_xcvr);
                          printf("xl%d: choosing new default based "
                                  "on card type\n", sc->xl_unit);
                  }
          } else {
                  if (sc->xl_type == XL_TYPE_905B &&
                      sc->xl_media & XL_MEDIAOPT_10FL)
                          return;
                  printf("xl%d: WARNING: no media options bits set in "
                          "the media options register!!\n", sc->xl_unit);
                  printf("xl%d: this could be a manufacturing defect in "
                          "your adapter or system\n", sc->xl_unit);
                  printf("xl%d: attempting to guess media type; you "
                          "should probably consult your vendor\n", sc->xl_unit);
          }
  
          xl_choose_xcvr(sc, 1);
  
          return;
  }
  
  static void
  xl_choose_xcvr(sc, verbose)
          struct xl_softc         *sc;
          int                     verbose;
  {
          u_int16_t               devid;
  
          /*
           * Read the device ID from the EEPROM.
           * This is what's loaded into the PCI device ID register, so it has
           * to be correct otherwise we wouldn't have gotten this far.
           */
          xl_read_eeprom(sc, (caddr_t)&devid, XL_EE_PRODID, 1, 0);
  
          switch(devid) {
          case TC_DEVICEID_BOOMERANG_10BT:        /* 3c900-TPO */
          case TC_DEVICEID_KRAKATOA_10BT:         /* 3c900B-TPO */
                  sc->xl_media = XL_MEDIAOPT_BT;
                  sc->xl_xcvr = XL_XCVR_10BT;
                  if (verbose)
                          printf("xl%d: guessing 10BaseT "
                              "transceiver\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_BOOMERANG_10BT_COMBO:  /* 3c900-COMBO */
          case TC_DEVICEID_KRAKATOA_10BT_COMBO:   /* 3c900B-COMBO */
                  sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                  sc->xl_xcvr = XL_XCVR_10BT;
                  if (verbose)
                          printf("xl%d: guessing COMBO "
                              "(AUI/BNC/TP)\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_KRAKATOA_10BT_TPC:     /* 3c900B-TPC */
                  sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC;
                  sc->xl_xcvr = XL_XCVR_10BT;
                  if (verbose)
                          printf("xl%d: guessing TPC (BNC/TP)\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_CYCLONE_10FL:          /* 3c900B-FL */
                  sc->xl_media = XL_MEDIAOPT_10FL;
                  sc->xl_xcvr = XL_XCVR_AUI;
                  if (verbose)
                          printf("xl%d: guessing 10baseFL\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_BOOMERANG_10_100BT:    /* 3c905-TX */
          case TC_DEVICEID_HURRICANE_556:         /* 3c556 */
          case TC_DEVICEID_HURRICANE_556B:        /* 3c556B */
          case TC_DEVICEID_HURRICANE_575A:        /* 3c575TX */
          case TC_DEVICEID_HURRICANE_575B:        /* 3c575B */
          case TC_DEVICEID_HURRICANE_575C:        /* 3c575C */
          case TC_DEVICEID_HURRICANE_656:         /* 3c656 */
          case TC_DEVICEID_HURRICANE_656B:        /* 3c656B */
          case TC_DEVICEID_TORNADO_656C:          /* 3c656C */
                  sc->xl_media = XL_MEDIAOPT_MII;
                  sc->xl_xcvr = XL_XCVR_MII;
                  if (verbose)
                          printf("xl%d: guessing MII\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_BOOMERANG_100BT4:      /* 3c905-T4 */
          case TC_DEVICEID_CYCLONE_10_100BT4:     /* 3c905B-T4 */
                  sc->xl_media = XL_MEDIAOPT_BT4;
                  sc->xl_xcvr = XL_XCVR_MII;
                  if (verbose)
                          printf("xl%d: guessing 100BaseT4/MII\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_HURRICANE_10_100BT:    /* 3c905B-TX */
          case TC_DEVICEID_HURRICANE_10_100BT_SERV:/*3c980-TX */
          case TC_DEVICEID_TORNADO_10_100BT_SERV: /* 3c980C-TX */
          case TC_DEVICEID_HURRICANE_SOHO100TX:   /* 3cSOHO100-TX */
          case TC_DEVICEID_TORNADO_10_100BT:      /* 3c905C-TX */
          case TC_DEVICEID_TORNADO_HOMECONNECT:   /* 3c450-TX */
                  sc->xl_media = XL_MEDIAOPT_BTX;
                  sc->xl_xcvr = XL_XCVR_AUTO;
                  if (verbose)
                          printf("xl%d: guessing 10/100 internal\n", sc->xl_unit);
                  break;
          case TC_DEVICEID_CYCLONE_10_100_COMBO:  /* 3c905B-COMBO */
                  sc->xl_media = XL_MEDIAOPT_BTX|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                  sc->xl_xcvr = XL_XCVR_AUTO;
                  if (verbose)
                          printf("xl%d: guessing 10/100 "
                              "plus BNC/AUI\n", sc->xl_unit);
                  break;
          default:
                  printf("xl%d: unknown device ID: %x -- "
                          "defaulting to 10baseT\n", sc->xl_unit, devid);
                  sc->xl_media = XL_MEDIAOPT_BT;
                  break;
          }
  
          return;
  }
  
  /*
   * Attach the interface. Allocate softc structures, do ifmedia
   * setup and ethernet/BPF attach.
   */
  static int
  xl_attach(dev)
          device_t                dev;
  {
          u_char                  eaddr[ETHER_ADDR_LEN];
          u_int32_t               command;
          struct xl_softc         *sc;
          struct ifnet            *ifp;
          int                     media = IFM_ETHER|IFM_100_TX|IFM_FDX;
          int                     unit, error = 0, rid;
  
          sc = device_get_softc(dev);
          unit = device_get_unit(dev);
  
          mtx_init(&sc->xl_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
              MTX_DEF | MTX_RECURSE);
          XL_LOCK(sc);
  
          sc->xl_flags = 0;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_556 ||
              pci_get_device(dev) == TC_DEVICEID_HURRICANE_556B)
                  sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK |
                      XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_WEIRDRESET |
                      XL_FLAG_INVERT_LED_PWR | XL_FLAG_INVERT_MII_PWR;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_556)
                  sc->xl_flags |= XL_FLAG_8BITROM;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_556B)
                  sc->xl_flags |= XL_FLAG_NO_XCVR_PWR;
  
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575A ||
              pci_get_device(dev) == TC_DEVICEID_HURRICANE_575B ||
              pci_get_device(dev) == TC_DEVICEID_HURRICANE_575C ||
              pci_get_device(dev) == TC_DEVICEID_HURRICANE_656B ||
              pci_get_device(dev) == TC_DEVICEID_TORNADO_656C)
                  sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK |
                      XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_8BITROM;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_656)
                  sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575B)
                  sc->xl_flags |= XL_FLAG_INVERT_LED_PWR;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_575C)
                  sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
          if (pci_get_device(dev) == TC_DEVICEID_TORNADO_656C)
                  sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
          if (pci_get_device(dev) == TC_DEVICEID_HURRICANE_656 ||
              pci_get_device(dev) == TC_DEVICEID_HURRICANE_656B)
                  sc->xl_flags |= XL_FLAG_INVERT_MII_PWR |
                      XL_FLAG_INVERT_LED_PWR;
  
          /*
           * If this is a 3c905B, we have to check one extra thing.
           * The 905B supports power management and may be placed in
           * a low-power mode (D3 mode), typically by certain operating
           * systems which shall not be named. The PCI BIOS is supposed
           * to reset the NIC and bring it out of low-power mode, but
           * some do not. Consequently, we have to see if this chip
           * supports power management, and if so, make sure it's not
           * in low-power mode. If power management is available, the
           * capid byte will be 0x01.
           *
           * I _think_ that what actually happens is that the chip
           * loses its PCI configuration during the transition from
           * D3 back to D0; this means that it should be possible for
           * us to save the PCI iobase, membase and IRQ, put the chip
           * back in the D0 state, then restore the PCI config ourselves.
           */
  
          if (pci_get_powerstate(dev) != PCI_POWERSTATE_D0) {
                  u_int32_t               iobase, membase, irq;
  
                  /* Save important PCI config data. */
                  iobase = pci_read_config(dev, XL_PCI_LOIO, 4);
                  membase = pci_read_config(dev, XL_PCI_LOMEM, 4);
                  irq = pci_read_config(dev, XL_PCI_INTLINE, 4);
  
                  /* Reset the power state. */
                  printf("xl%d: chip is in D%d power mode "
                      "-- setting to D0\n", unit,
                      pci_get_powerstate(dev));
  
                  pci_set_powerstate(dev, PCI_POWERSTATE_D0);
  
                  /* Restore PCI config data. */
                  pci_write_config(dev, XL_PCI_LOIO, iobase, 4);
                  pci_write_config(dev, XL_PCI_LOMEM, membase, 4);
                  pci_write_config(dev, XL_PCI_INTLINE, irq, 4);
          }
  
          /*
           * Map control/status registers.
           */
          pci_enable_busmaster(dev);
          pci_enable_io(dev, SYS_RES_IOPORT);
          pci_enable_io(dev, SYS_RES_MEMORY);
          command = pci_read_config(dev, PCIR_COMMAND, 4);
  
  #ifdef XL_USEIOSPACE
          if (!(command & PCIM_CMD_PORTEN)) {
                  printf("xl%d: failed to enable I/O ports!\n", unit);
                  error = ENXIO;
                  goto fail;
          }
  #else
          if (!(command & PCIM_CMD_MEMEN)) {
                  printf("xl%d: failed to enable memory mapping!\n", unit);
                  error = ENXIO;
                  goto fail;
          }
  #endif
  
          rid = XL_RID;
          sc->xl_res = bus_alloc_resource(dev, XL_RES, &rid,
              0, ~0, 1, RF_ACTIVE);
  
          if (sc->xl_res == NULL) {
                  printf ("xl%d: couldn't map ports/memory\n", unit);
                  error = ENXIO;
                  goto fail;
          }
  
          sc->xl_btag = rman_get_bustag(sc->xl_res);
          sc->xl_bhandle = rman_get_bushandle(sc->xl_res);
  
          if (sc->xl_flags & XL_FLAG_FUNCREG) {
                  rid = XL_PCI_FUNCMEM;
                  sc->xl_fres = bus_alloc_resource(dev, SYS_RES_MEMORY, &rid,
                      0, ~0, 1, RF_ACTIVE);
  
                  if (sc->xl_fres == NULL) {
                          printf ("xl%d: couldn't map ports/memory\n", unit);
                          bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                          error = ENXIO;
                          goto fail;
                  }
  
                  sc->xl_ftag = rman_get_bustag(sc->xl_fres);
                  sc->xl_fhandle = rman_get_bushandle(sc->xl_fres);
          }
  
          rid = 0;
          sc->xl_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
              RF_SHAREABLE | RF_ACTIVE);
  
          if (sc->xl_irq == NULL) {
                  printf("xl%d: couldn't map interrupt\n", unit);
                  if (sc->xl_fres != NULL)
                          bus_release_resource(dev, SYS_RES_MEMORY,
                              XL_PCI_FUNCMEM, sc->xl_fres);
                  bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                  error = ENXIO;
                  goto fail;
          }
  
          error = bus_setup_intr(dev, sc->xl_irq, INTR_TYPE_NET,
              xl_intr, sc, &sc->xl_intrhand);
  
          if (error) {
                  bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                  if (sc->xl_fres != NULL)
                          bus_release_resource(dev, SYS_RES_MEMORY,
                              XL_PCI_FUNCMEM, sc->xl_fres);
                  bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                  printf("xl%d: couldn't set up irq\n", unit);
                  goto fail;
          }
  
          /* Reset the adapter. */
          xl_reset(sc);
  
          /*
           * Get station address from the EEPROM.
           */
          if (xl_read_eeprom(sc, (caddr_t)&eaddr, XL_EE_OEM_ADR0, 3, 1)) {
                  printf("xl%d: failed to read station address\n", sc->xl_unit);
                  bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                  bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                  if (sc->xl_fres != NULL)
                          bus_release_resource(dev, SYS_RES_MEMORY,
                              XL_PCI_FUNCMEM, sc->xl_fres);
                  bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                  error = ENXIO;
                  goto fail;
          }
  
          /*
           * A 3Com chip was detected. Inform the world.
           */
          printf("xl%d: Ethernet address: %6D\n", unit, eaddr, ":");
  
          sc->xl_unit = unit;
          callout_handle_init(&sc->xl_stat_ch);
          bcopy(eaddr, (char *)&sc->arpcom.ac_enaddr, ETHER_ADDR_LEN);
  
          sc->xl_ldata = contigmalloc(sizeof(struct xl_list_data), M_DEVBUF,
              M_NOWAIT, 0, 0xffffffff, PAGE_SIZE, 0);
  
          if (sc->xl_ldata == NULL) {
                  printf("xl%d: no memory for list buffers!\n", unit);
                  bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                  bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                  if (sc->xl_fres != NULL)
                          bus_release_resource(dev, SYS_RES_MEMORY,
                              XL_PCI_FUNCMEM, sc->xl_fres);
                  bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                  error = ENXIO;
                  goto fail;
          }
  
          bzero(sc->xl_ldata, sizeof(struct xl_list_data));
  
          /*
           * Figure out the card type. 3c905B adapters have the
           * 'supportsNoTxLength' bit set in the capabilities
           * word in the EEPROM.
           */
          xl_read_eeprom(sc, (caddr_t)&sc->xl_caps, XL_EE_CAPS, 1, 0);
          if (sc->xl_caps & XL_CAPS_NO_TXLENGTH)
                  sc->xl_type = XL_TYPE_905B;
          else
                  sc->xl_type = XL_TYPE_90X;
  
          ifp = &sc->arpcom.ac_if;
          ifp->if_softc = sc;
          ifp->if_unit = unit;
          ifp->if_name = "xl";
          ifp->if_mtu = ETHERMTU;
          ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
          ifp->if_ioctl = xl_ioctl;
          ifp->if_output = ether_output;
          if (sc->xl_type == XL_TYPE_905B) {
                  ifp->if_start = xl_start_90xB;
                  ifp->if_hwassist = XL905B_CSUM_FEATURES;
                  ifp->if_capabilities = IFCAP_HWCSUM;
          } else
                  ifp->if_start = xl_start;
          ifp->if_watchdog = xl_watchdog;
          ifp->if_init = xl_init;
          ifp->if_baudrate = 10000000;
          ifp->if_snd.ifq_maxlen = XL_TX_LIST_CNT - 1;
          ifp->if_capenable = ifp->if_capabilities;
  
          /*
           * Now we have to see what sort of media we have.
           * This includes probing for an MII interace and a
           * possible PHY.
           */
          XL_SEL_WIN(3);
          sc->xl_media = CSR_READ_2(sc, XL_W3_MEDIA_OPT);
          if (bootverbose)
                  printf("xl%d: media options word: %x\n", sc->xl_unit,
                                                           sc->xl_media);
  
          xl_read_eeprom(sc, (char *)&sc->xl_xcvr, XL_EE_ICFG_0, 2, 0);
          sc->xl_xcvr &= XL_ICFG_CONNECTOR_MASK;
          sc->xl_xcvr >>= XL_ICFG_CONNECTOR_BITS;
  
          xl_mediacheck(sc);
  
          if (sc->xl_media & XL_MEDIAOPT_MII || sc->xl_media & XL_MEDIAOPT_BTX
                          || sc->xl_media & XL_MEDIAOPT_BT4) {
                  if (bootverbose)
                          printf("xl%d: found MII/AUTO\n", sc->xl_unit);
                  xl_setcfg(sc);
                  if (mii_phy_probe(dev, &sc->xl_miibus,
                      xl_ifmedia_upd, xl_ifmedia_sts)) {
                          printf("xl%d: no PHY found!\n", sc->xl_unit);
                          bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
                          bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
                          bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
                          contigfree(sc->xl_ldata,
                              sizeof(struct xl_list_data), M_DEVBUF);
                          error = ENXIO;
                          goto fail;
                  }
  
                  goto done;
          }
  
          /*
           * Sanity check. If the user has selected "auto" and this isn't
           * a 10/100 card of some kind, we need to force the transceiver
           * type to something sane.
           */
          if (sc->xl_xcvr == XL_XCVR_AUTO)
                  xl_choose_xcvr(sc, bootverbose);
  
          /*
           * Do ifmedia setup.
           */
  
          ifmedia_init(&sc->ifmedia, 0, xl_ifmedia_upd, xl_ifmedia_sts);
  
          if (sc->xl_media & XL_MEDIAOPT_BT) {
                  if (bootverbose)
                          printf("xl%d: found 10baseT\n", sc->xl_unit);
                  ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T, 0, NULL);
                  ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T|IFM_HDX, 0, NULL);
                  if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                          ifmedia_add(&sc->ifmedia,
                              IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
          }
  
          if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                  /*
                   * Check for a 10baseFL board in disguise.
                   */
                  if (sc->xl_type == XL_TYPE_905B &&
                      sc->xl_media == XL_MEDIAOPT_10FL) {
                          if (bootverbose)
                                  printf("xl%d: found 10baseFL\n", sc->xl_unit);
                          ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL, 0, NULL);
                          ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL|IFM_HDX,
                              0, NULL);
                          if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                  ifmedia_add(&sc->ifmedia,
                                      IFM_ETHER|IFM_10_FL|IFM_FDX, 0, NULL);
                  } else {
                          if (bootverbose)
                                  printf("xl%d: found AUI\n", sc->xl_unit);
                          ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_5, 0, NULL);
                  }
          }
  
          if (sc->xl_media & XL_MEDIAOPT_BNC) {
                  if (bootverbose)
                          printf("xl%d: found BNC\n", sc->xl_unit);
                  ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_2, 0, NULL);
          }
  
          if (sc->xl_media & XL_MEDIAOPT_BFX) {
                  if (bootverbose)
                          printf("xl%d: found 100baseFX\n", sc->xl_unit);
                  ifp->if_baudrate = 100000000;
                  ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_100_FX, 0, NULL);
          }
  
          /* Choose a default media. */
          switch(sc->xl_xcvr) {
          case XL_XCVR_10BT:
                  media = IFM_ETHER|IFM_10_T;
                  xl_setmode(sc, media);
                  break;
          case XL_XCVR_AUI:
                  if (sc->xl_type == XL_TYPE_905B &&
                      sc->xl_media == XL_MEDIAOPT_10FL) {
                          media = IFM_ETHER|IFM_10_FL;
                          xl_setmode(sc, media);
                  } else {
                          media = IFM_ETHER|IFM_10_5;
                          xl_setmode(sc, media);
                  }
                  break;
          case XL_XCVR_COAX:
                  media = IFM_ETHER|IFM_10_2;
                  xl_setmode(sc, media);
                  break;
          case XL_XCVR_AUTO:
          case XL_XCVR_100BTX:
          case XL_XCVR_MII:
                  /* Chosen by miibus */
                  break;
          case XL_XCVR_100BFX:
                  media = IFM_ETHER|IFM_100_FX;
                  break;
          default:
                  printf("xl%d: unknown XCVR type: %d\n", sc->xl_unit,
                                                          sc->xl_xcvr);
                  /*
                   * This will probably be wrong, but it prevents
                   * the ifmedia code from panicking.
                   */
                  media = IFM_ETHER|IFM_10_T;
                  break;
          }
  
          if (sc->xl_miibus == NULL)
                  ifmedia_set(&sc->ifmedia, media);
  
  done:
  
          if (sc->xl_flags & XL_FLAG_NO_XCVR_PWR) {
                  XL_SEL_WIN(0);
                  CSR_WRITE_2(sc, XL_W0_MFG_ID, XL_NO_XCVR_PWR_MAGICBITS);
          }
  
          /*
           * Call MI attach routine.
           */
          ether_ifattach(ifp, eaddr);
          XL_UNLOCK(sc);
          return(0);
  
  fail:
          XL_UNLOCK(sc);
          mtx_destroy(&sc->xl_mtx);
  
          return(error);
  }
  
  static int
  xl_detach(dev)
          device_t                dev;
  {
          struct xl_softc         *sc;
          struct ifnet            *ifp;
  
          sc = device_get_softc(dev);
          XL_LOCK(sc);
          ifp = &sc->arpcom.ac_if;
  
          xl_reset(sc);
          xl_stop(sc);
          ether_ifdetach(ifp);
  
          /* Delete any miibus and phy devices attached to this interface */
          if (sc->xl_miibus != NULL) {
                  bus_generic_detach(dev);
                  device_delete_child(dev, sc->xl_miibus);
          }
  
          bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
          bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
          if (sc->xl_fres != NULL)
                  bus_release_resource(dev, SYS_RES_MEMORY,
                      XL_PCI_FUNCMEM, sc->xl_fres);
          bus_release_resource(dev, XL_RES, XL_RID, sc->xl_res);
  
          ifmedia_removeall(&sc->ifmedia);
          contigfree(sc->xl_ldata, sizeof(struct xl_list_data), M_DEVBUF);
  
          XL_UNLOCK(sc);
          mtx_destroy(&sc->xl_mtx);
  
          return(0);
  }
  
  /*
   * Initialize the transmit descriptors.
   */
  static int
  xl_list_tx_init(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain_data    *cd;
          struct xl_list_data     *ld;
          int                     i;
  
          cd = &sc->xl_cdata;
          ld = sc->xl_ldata;
          for (i = 0; i < XL_TX_LIST_CNT; i++) {
                  cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                  if (i == (XL_TX_LIST_CNT - 1))
                          cd->xl_tx_chain[i].xl_next = NULL;
                  else
                          cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
          }
  
          cd->xl_tx_free = &cd->xl_tx_chain[0];
          cd->xl_tx_tail = cd->xl_tx_head = NULL;
  
          return(0);
  }
  
  /*
   * Initialize the transmit descriptors.
   */
  static int xl_list_tx_init_90xB(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain_data    *cd;
          struct xl_list_data     *ld;
          int                     i;
  
          cd = &sc->xl_cdata;
          ld = sc->xl_ldata;
          for (i = 0; i < XL_TX_LIST_CNT; i++) {
                  cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                  cd->xl_tx_chain[i].xl_phys = vtophys(&ld->xl_tx_list[i]);
                  if (i == (XL_TX_LIST_CNT - 1))
                          cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[0];
                  else
                          cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
                  if (i == 0)
                          cd->xl_tx_chain[i].xl_prev =
                              &cd->xl_tx_chain[XL_TX_LIST_CNT - 1];
                  else
                          cd->xl_tx_chain[i].xl_prev =
                              &cd->xl_tx_chain[i - 1];
          }
  
          bzero((char *)ld->xl_tx_list,
              sizeof(struct xl_list) * XL_TX_LIST_CNT);
          ld->xl_tx_list[0].xl_status = XL_TXSTAT_EMPTY;
  
          cd->xl_tx_prod = 1;
          cd->xl_tx_cons = 1;
          cd->xl_tx_cnt = 0;
  
          return(0);
  }
  
  /*
   * Initialize the RX descriptors and allocate mbufs for them. Note that
   * we arrange the descriptors in a closed ring, so that the last descriptor
   * points back to the first.
   */
  static int
  xl_list_rx_init(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain_data    *cd;
          struct xl_list_data     *ld;
          int                     i;
  
          cd = &sc->xl_cdata;
          ld = sc->xl_ldata;
  
          for (i = 0; i < XL_RX_LIST_CNT; i++) {
                  cd->xl_rx_chain[i].xl_ptr =
                          (struct xl_list_onefrag *)&ld->xl_rx_list[i];
                  if (xl_newbuf(sc, &cd->xl_rx_chain[i]) == ENOBUFS)
                          return(ENOBUFS);
                  if (i == (XL_RX_LIST_CNT - 1)) {
                          cd->xl_rx_chain[i].xl_next = &cd->xl_rx_chain[0];
                          ld->xl_rx_list[i].xl_next =
                              vtophys(&ld->xl_rx_list[0]);
                  } else {
                          cd->xl_rx_chain[i].xl_next = &cd->xl_rx_chain[i + 1];
                          ld->xl_rx_list[i].xl_next =
                              vtophys(&ld->xl_rx_list[i + 1]);
                  }
          }
  
          cd->xl_rx_head = &cd->xl_rx_chain[0];
  
          return(0);
  }
  
  /*
   * Initialize an RX descriptor and attach an MBUF cluster.
   */
  static int
  xl_newbuf(sc, c)
          struct xl_softc         *sc;
          struct xl_chain_onefrag *c;
  {
          struct mbuf             *m_new = NULL;
  
          MGETHDR(m_new, M_DONTWAIT, MT_DATA);
          if (m_new == NULL)
                  return(ENOBUFS);
  
          MCLGET(m_new, M_DONTWAIT);
          if (!(m_new->m_flags & M_EXT)) {
                  m_freem(m_new);
                  return(ENOBUFS);
          }
  
          m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
  
          /* Force longword alignment for packet payload. */
          m_adj(m_new, ETHER_ALIGN);
  
          c->xl_mbuf = m_new;
          c->xl_ptr->xl_frag.xl_addr = vtophys(mtod(m_new, caddr_t));
          c->xl_ptr->xl_frag.xl_len = MCLBYTES | XL_LAST_FRAG;
          c->xl_ptr->xl_status = 0;
  
          return(0);
  }
  
  static int
  xl_rx_resync(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain_onefrag *pos;
          int                     i;
  
          pos = sc->xl_cdata.xl_rx_head;
  
          for (i = 0; i < XL_RX_LIST_CNT; i++) {
                  if (pos->xl_ptr->xl_status)
                          break;
                  pos = pos->xl_next;
          }
  
          if (i == XL_RX_LIST_CNT)
                  return(0);
  
          sc->xl_cdata.xl_rx_head = pos;
  
          return(EAGAIN);
  }
  
  /*
   * A frame has been uploaded: pass the resulting mbuf chain up to
   * the higher level protocols.
   */
  static void
  xl_rxeof(sc)
          struct xl_softc         *sc;
  {
          struct mbuf             *m;
          struct ifnet            *ifp;
          struct xl_chain_onefrag *cur_rx;
          int                     total_len = 0;
          u_int32_t               rxstat;
  
          ifp = &sc->arpcom.ac_if;
  
  again:
  
          while((rxstat = sc->xl_cdata.xl_rx_head->xl_ptr->xl_status)) {
                  cur_rx = sc->xl_cdata.xl_rx_head;
                  sc->xl_cdata.xl_rx_head = cur_rx->xl_next;
  
                  /*
                   * If an error occurs, update stats, clear the
                   * status word and leave the mbuf cluster in place:
                   * it should simply get re-used next time this descriptor
                   * comes up in the ring.
                   */
                  if (rxstat & XL_RXSTAT_UP_ERROR) {
                          ifp->if_ierrors++;
                          cur_rx->xl_ptr->xl_status = 0;
                          continue;
                  }
  
                  /*
                   * If there error bit was not set, the upload complete
                   * bit should be set which means we have a valid packet.
                   * If not, something truly strange has happened.
                   */
                  if (!(rxstat & XL_RXSTAT_UP_CMPLT)) {
                          printf("xl%d: bad receive status -- "
                              "packet dropped\n", sc->xl_unit);
                          ifp->if_ierrors++;
                          cur_rx->xl_ptr->xl_status = 0;
                          continue;
                  }
  
                  /* No errors; receive the packet. */    
                  m = cur_rx->xl_mbuf;
                  total_len = cur_rx->xl_ptr->xl_status & XL_RXSTAT_LENMASK;
  
                  /*
                   * Try to conjure up a new mbuf cluster. If that
                   * fails, it means we have an out of memory condition and
                   * should leave the buffer in place and continue. This will
                   * result in a lost packet, but there's little else we
                   * can do in this situation.
                   */
                  if (xl_newbuf(sc, cur_rx) == ENOBUFS) {
                          ifp->if_ierrors++;
                          cur_rx->xl_ptr->xl_status = 0;
                          continue;
                  }
  
                  ifp->if_ipackets++;
                  m->m_pkthdr.rcvif = ifp;
                  m->m_pkthdr.len = m->m_len = total_len;
  
                  if (sc->xl_type == XL_TYPE_905B) {
                          /* Do IP checksum checking. */
                          if (rxstat & XL_RXSTAT_IPCKOK)
                                  m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
                          if (!(rxstat & XL_RXSTAT_IPCKERR))
                                  m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
                          if ((rxstat & XL_RXSTAT_TCPCOK &&
                               !(rxstat & XL_RXSTAT_TCPCKERR)) ||
                              (rxstat & XL_RXSTAT_UDPCKOK &&
                               !(rxstat & XL_RXSTAT_UDPCKERR))) {
                                  m->m_pkthdr.csum_flags |=
                                          CSUM_DATA_VALID|CSUM_PSEUDO_HDR;
                                  m->m_pkthdr.csum_data = 0xffff;
                          }
                  }
  
                  (*ifp->if_input)(ifp, m);
          }
  
          /*
           * Handle the 'end of channel' condition. When the upload
           * engine hits the end of the RX ring, it will stall. This
           * is our cue to flush the RX ring, reload the uplist pointer
           * register and unstall the engine.
           * XXX This is actually a little goofy. With the ThunderLAN
           * chip, you get an interrupt when the receiver hits the end
           * of the receive ring, which tells you exactly when you
           * you need to reload the ring pointer. Here we have to
           * fake it. I'm mad at myself for not being clever enough
           * to avoid the use of a goto here.
           */
          if (CSR_READ_4(sc, XL_UPLIST_PTR) == 0 ||
                  CSR_READ_4(sc, XL_UPLIST_STATUS) & XL_PKTSTAT_UP_STALLED) {
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
                  xl_wait(sc);
                  CSR_WRITE_4(sc, XL_UPLIST_PTR,
                          vtophys(&sc->xl_ldata->xl_rx_list[0]));
                  sc->xl_cdata.xl_rx_head = &sc->xl_cdata.xl_rx_chain[0];
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
                  goto again;
          }
  
          return;
  }
  
  /*
   * A frame was downloaded to the chip. It's safe for us to clean up
   * the list buffers.
   */
  static void
  xl_txeof(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain         *cur_tx;
          struct ifnet            *ifp;
  
          ifp = &sc->arpcom.ac_if;
  
          /* Clear the timeout timer. */
          ifp->if_timer = 0;
  
          /*
           * Go through our tx list and free mbufs for those
           * frames that have been uploaded. Note: the 3c905B
           * sets a special bit in the status word to let us
           * know that a frame has been downloaded, but the
           * original 3c900/3c905 adapters don't do that.
           * Consequently, we have to use a different test if
           * xl_type != XL_TYPE_905B.
           */
          while(sc->xl_cdata.xl_tx_head != NULL) {
                  cur_tx = sc->xl_cdata.xl_tx_head;
  
                  if (CSR_READ_4(sc, XL_DOWNLIST_PTR))
                          break;
  
                  sc->xl_cdata.xl_tx_head = cur_tx->xl_next;
                  m_freem(cur_tx->xl_mbuf);
                  cur_tx->xl_mbuf = NULL;
                  ifp->if_opackets++;
  
                  cur_tx->xl_next = sc->xl_cdata.xl_tx_free;
                  sc->xl_cdata.xl_tx_free = cur_tx;
          }
  
          if (sc->xl_cdata.xl_tx_head == NULL) {
                  ifp->if_flags &= ~IFF_OACTIVE;
                  sc->xl_cdata.xl_tx_tail = NULL;
          } else {
                  if (CSR_READ_4(sc, XL_DMACTL) & XL_DMACTL_DOWN_STALLED ||
                          !CSR_READ_4(sc, XL_DOWNLIST_PTR)) {
                          CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                  vtophys(sc->xl_cdata.xl_tx_head->xl_ptr));
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                  }
          }
  
          return;
  }
  
  static void xl_txeof_90xB(sc)
          struct xl_softc         *sc;
  {
          struct xl_chain         *cur_tx = NULL;
          struct ifnet            *ifp;
          int                     idx;
  
          ifp = &sc->arpcom.ac_if;
  
          idx = sc->xl_cdata.xl_tx_cons;
          while(idx != sc->xl_cdata.xl_tx_prod) {
  
                  cur_tx = &sc->xl_cdata.xl_tx_chain[idx];
  
                  if (!(cur_tx->xl_ptr->xl_status & XL_TXSTAT_DL_COMPLETE))
                          break;
  
                  if (cur_tx->xl_mbuf != NULL) {
                          m_freem(cur_tx->xl_mbuf);
                          cur_tx->xl_mbuf = NULL;
                  }
  
                  ifp->if_opackets++;
  
                  sc->xl_cdata.xl_tx_cnt--;
                  XL_INC(idx, XL_TX_LIST_CNT);
                  ifp->if_timer = 0;
          }
  
          sc->xl_cdata.xl_tx_cons = idx;
  
          if (cur_tx != NULL)
                  ifp->if_flags &= ~IFF_OACTIVE;
  
          return;
  }
  
  /*
   * TX 'end of channel' interrupt handler. Actually, we should
   * only get a 'TX complete' interrupt if there's a transmit error,
   * so this is really TX error handler.
   */
  static void
  xl_txeoc(sc)
          struct xl_softc         *sc;
  {
          u_int8_t                txstat;
  
          while((txstat = CSR_READ_1(sc, XL_TX_STATUS))) {
                  if (txstat & XL_TXSTATUS_UNDERRUN ||
                          txstat & XL_TXSTATUS_JABBER ||
                          txstat & XL_TXSTATUS_RECLAIM) {
                          printf("xl%d: transmission error: %x\n",
                                                  sc->xl_unit, txstat);
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
                          xl_wait(sc);
                          if (sc->xl_type == XL_TYPE_905B) {
                                  if (sc->xl_cdata.xl_tx_cnt) {
                                          int                     i;
                                          struct xl_chain         *c;
                                          i = sc->xl_cdata.xl_tx_cons;
                                          c = &sc->xl_cdata.xl_tx_chain[i];
                                          CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                              c->xl_phys);
                                          CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                                  }
                          } else {
                                  if (sc->xl_cdata.xl_tx_head != NULL)
                                          CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                  vtophys(sc->xl_cdata.xl_tx_head->xl_ptr));
                          }
                          /*
                           * Remember to set this for the
                           * first generation 3c90X chips.
                           */
                          CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);
                          if (txstat & XL_TXSTATUS_UNDERRUN &&
                              sc->xl_tx_thresh < XL_PACKET_SIZE) {
                                  sc->xl_tx_thresh += XL_MIN_FRAMELEN;
                                  printf("xl%d: tx underrun, increasing tx start"
                                      " threshold to %d bytes\n", sc->xl_unit,
                                      sc->xl_tx_thresh);
                          }
                          CSR_WRITE_2(sc, XL_COMMAND,
                              XL_CMD_TX_SET_START|sc->xl_tx_thresh);
                          if (sc->xl_type == XL_TYPE_905B) {
                                  CSR_WRITE_2(sc, XL_COMMAND,
                                  XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
                          }
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                  } else {
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                  }
                  /*
                   * Write an arbitrary byte to the TX_STATUS register
                   * to clear this interrupt/error and advance to the next.
                   */
                  CSR_WRITE_1(sc, XL_TX_STATUS, 0x01);
          }
  
          return;
  }
  
  static void
  xl_intr(arg)
          void                    *arg;
  {
          struct xl_softc         *sc;
          struct ifnet            *ifp;
          u_int16_t               status;
  
          sc = arg;
          XL_LOCK(sc);
          ifp = &sc->arpcom.ac_if;
  
          while((status = CSR_READ_2(sc, XL_STATUS)) & XL_INTRS && status != 0xFFFF) {
  
                  CSR_WRITE_2(sc, XL_COMMAND,
                      XL_CMD_INTR_ACK|(status & XL_INTRS));
  
                  if (status & XL_STAT_UP_COMPLETE) {
                          int                     curpkts;
  
                          curpkts = ifp->if_ipackets;
                          xl_rxeof(sc);
                          if (curpkts == ifp->if_ipackets) {
                                  while (xl_rx_resync(sc))
                                          xl_rxeof(sc);
                          }
                  }
  
                  if (status & XL_STAT_DOWN_COMPLETE) {
                          if (sc->xl_type == XL_TYPE_905B)
                                  xl_txeof_90xB(sc);
                          else
                                  xl_txeof(sc);
                  }
  
                  if (status & XL_STAT_TX_COMPLETE) {
                          ifp->if_oerrors++;
                          xl_txeoc(sc);
                  }
  
                  if (status & XL_STAT_ADFAIL) {
                          xl_reset(sc);
                          xl_init(sc);
                  }
  
                  if (status & XL_STAT_STATSOFLOW) {
                          sc->xl_stats_no_timeout = 1;
                          xl_stats_update(sc);
                          sc->xl_stats_no_timeout = 0;
                  }
          }
  
          if (ifp->if_snd.ifq_head != NULL)
                  (*ifp->if_start)(ifp);
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  static void
  xl_stats_update(xsc)
          void                    *xsc;
  {
          struct xl_softc         *sc;
          struct ifnet            *ifp;
          struct xl_stats         xl_stats;
          u_int8_t                *p;
          int                     i;
          struct mii_data         *mii = NULL;
  
          bzero((char *)&xl_stats, sizeof(struct xl_stats));
  
          sc = xsc;
          ifp = &sc->arpcom.ac_if;
          if (sc->xl_miibus != NULL)
                  mii = device_get_softc(sc->xl_miibus);
  
          p = (u_int8_t *)&xl_stats;
  
          /* Read all the stats registers. */
          XL_SEL_WIN(6);
  
          for (i = 0; i < 16; i++)
                  *p++ = CSR_READ_1(sc, XL_W6_CARRIER_LOST + i);
  
          ifp->if_ierrors += xl_stats.xl_rx_overrun;
  
          ifp->if_collisions += xl_stats.xl_tx_multi_collision +
                                  xl_stats.xl_tx_single_collision +
                                  xl_stats.xl_tx_late_collision;
  
          /*
           * Boomerang and cyclone chips have an extra stats counter
           * in window 4 (BadSSD). We have to read this too in order
           * to clear out all the stats registers and avoid a statsoflow
           * interrupt.
           */
          XL_SEL_WIN(4);
          CSR_READ_1(sc, XL_W4_BADSSD);
  
          if ((mii != NULL) && (!sc->xl_stats_no_timeout))
                  mii_tick(mii);
  
          XL_SEL_WIN(7);
  
          if (!sc->xl_stats_no_timeout)
                  sc->xl_stat_ch = timeout(xl_stats_update, sc, hz);
  
          return;
  }
  
  /*
   * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
   * pointers to the fragment pointers.
   */
  static int
  xl_encap(sc, c, m_head)
          struct xl_softc         *sc;
          struct xl_chain         *c;
          struct mbuf             *m_head;
  {
          int                     frag = 0;
          struct xl_frag          *f = NULL;
          int                     total_len;
          struct mbuf             *m;
  
          /*
           * Start packing the mbufs in this chain into
           * the fragment pointers. Stop when we run out
           * of fragments or hit the end of the mbuf chain.
           */
          m = m_head;
          total_len = 0;
  
          for (m = m_head, frag = 0; m != NULL; m = m->m_next) {
                  if (m->m_len != 0) {
                          if (frag == XL_MAXFRAGS)
                                  break;
                          total_len+= m->m_len;
                          c->xl_ptr->xl_frag[frag].xl_addr =
                                          vtophys(mtod(m, vm_offset_t));
                          c->xl_ptr->xl_frag[frag].xl_len = m->m_len;
                          frag++;
                  }
          }
  
          /*
           * Handle special case: we used up all 63 fragments,
           * but we have more mbufs left in the chain. Copy the
           * data into an mbuf cluster. Note that we don't
           * bother clearing the values in the other fragment
           * pointers/counters; it wouldn't gain us anything,
           * and would waste cycles.
           */
          if (m != NULL) {
                  struct mbuf             *m_new = NULL;
  
                  MGETHDR(m_new, M_DONTWAIT, MT_DATA);
                  if (m_new == NULL) {
                          printf("xl%d: no memory for tx list\n", sc->xl_unit);
                          return(1);
                  }
                  if (m_head->m_pkthdr.len > MHLEN) {
                          MCLGET(m_new, M_DONTWAIT);
                          if (!(m_new->m_flags & M_EXT)) {
                                  m_freem(m_new);
                                  printf("xl%d: no memory for tx list\n",
                                                  sc->xl_unit);
                                  return(1);
                          }
                  }
                  m_copydata(m_head, 0, m_head->m_pkthdr.len,     
                                          mtod(m_new, caddr_t));
                  m_new->m_pkthdr.len = m_new->m_len = m_head->m_pkthdr.len;
                  m_freem(m_head);
                  m_head = m_new;
                  f = &c->xl_ptr->xl_frag[0];
                  f->xl_addr = vtophys(mtod(m_new, caddr_t));
                  f->xl_len = total_len = m_new->m_len;
                  frag = 1;
          }
  
          c->xl_mbuf = m_head;
          c->xl_ptr->xl_frag[frag - 1].xl_len |=  XL_LAST_FRAG;
          c->xl_ptr->xl_status = total_len;
          c->xl_ptr->xl_next = 0;
  
          return(0);
  }
  
  /*
   * Main transmit routine. To avoid having to do mbuf copies, we put pointers
   * to the mbuf data regions directly in the transmit lists. We also save a
   * copy of the pointers since the transmit list fragment pointers are
   * physical addresses.
   */
  static void
  xl_start(ifp)
          struct ifnet            *ifp;
  {
          struct xl_softc         *sc;
          struct mbuf             *m_head = NULL;
          struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;
  
          sc = ifp->if_softc;
          XL_LOCK(sc);
          /*
           * Check for an available queue slot. If there are none,
           * punt.
           */
          if (sc->xl_cdata.xl_tx_free == NULL) {
                  xl_txeoc(sc);
                  xl_txeof(sc);
                  if (sc->xl_cdata.xl_tx_free == NULL) {
                          ifp->if_flags |= IFF_OACTIVE;
                          XL_UNLOCK(sc);
                          return;
                  }
          }
  
          start_tx = sc->xl_cdata.xl_tx_free;
  
          while(sc->xl_cdata.xl_tx_free != NULL) {
                  IF_DEQUEUE(&ifp->if_snd, m_head);
                  if (m_head == NULL)
                          break;
  
                  /* Pick a descriptor off the free list. */
                  cur_tx = sc->xl_cdata.xl_tx_free;
                  sc->xl_cdata.xl_tx_free = cur_tx->xl_next;
  
                  cur_tx->xl_next = NULL;
  
                  /* Pack the data into the descriptor. */
                  xl_encap(sc, cur_tx, m_head);
  
                  /* Chain it together. */
                  if (prev != NULL) {
                          prev->xl_next = cur_tx;
                          prev->xl_ptr->xl_next = vtophys(cur_tx->xl_ptr);
                  }
                  prev = cur_tx;
  
                  /*
                   * If there's a BPF listener, bounce a copy of this frame
                   * to him.
                   */
                  BPF_MTAP(ifp, cur_tx->xl_mbuf);
          }
  
          /*
           * If there are no packets queued, bail.
           */
          if (cur_tx == NULL) {
                  XL_UNLOCK(sc);
                  return;
          }
  
          /*
           * Place the request for the upload interrupt
           * in the last descriptor in the chain. This way, if
           * we're chaining several packets at once, we'll only
           * get an interupt once for the whole chain rather than
           * once for each packet.
           */
          cur_tx->xl_ptr->xl_status |= XL_TXSTAT_DL_INTR;
  
          /*
           * Queue the packets. If the TX channel is clear, update
           * the downlist pointer register.
           */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
          xl_wait(sc);
  
          if (sc->xl_cdata.xl_tx_head != NULL) {
                  sc->xl_cdata.xl_tx_tail->xl_next = start_tx;
                  sc->xl_cdata.xl_tx_tail->xl_ptr->xl_next =
                                          vtophys(start_tx->xl_ptr);
                  sc->xl_cdata.xl_tx_tail->xl_ptr->xl_status &=
                                          ~XL_TXSTAT_DL_INTR;
                  sc->xl_cdata.xl_tx_tail = cur_tx;
          } else {
                  sc->xl_cdata.xl_tx_head = start_tx;
                  sc->xl_cdata.xl_tx_tail = cur_tx;
          }
          if (!CSR_READ_4(sc, XL_DOWNLIST_PTR))
                  CSR_WRITE_4(sc, XL_DOWNLIST_PTR, vtophys(start_tx->xl_ptr));
  
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
  
          XL_SEL_WIN(7);
  
          /*
           * Set a timeout in case the chip goes out to lunch.
           */
          ifp->if_timer = 5;
  
          /*
           * XXX Under certain conditions, usually on slower machines
           * where interrupts may be dropped, it's possible for the
           * adapter to chew up all the buffers in the receive ring
           * and stall, without us being able to do anything about it.
           * To guard against this, we need to make a pass over the
           * RX queue to make sure there aren't any packets pending.
           * Doing it here means we can flush the receive ring at the
           * same time the chip is DMAing the transmit descriptors we
           * just gave it.
           *
           * 3Com goes to some lengths to emphasize the Parallel Tasking (tm)
           * nature of their chips in all their marketing literature;
           * we may as well take advantage of it. :)
           */
          xl_rxeof(sc);
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  static int xl_encap_90xB(sc, c, m_head)
          struct xl_softc         *sc;
          struct xl_chain         *c;
          struct mbuf             *m_head;
  {
          int                     frag = 0;
          struct xl_frag          *f = NULL;
          struct mbuf             *m;
          struct xl_list          *d;
  
          /*
           * Start packing the mbufs in this chain into
           * the fragment pointers. Stop when we run out
           * of fragments or hit the end of the mbuf chain.
           */
          d = c->xl_ptr;
          d->xl_status = 0;
          d->xl_next = 0;
  
          for (m = m_head, frag = 0; m != NULL; m = m->m_next) {
                  if (m->m_len != 0) {
                          if (frag == XL_MAXFRAGS)
                                  break;
                          f = &d->xl_frag[frag];
                          f->xl_addr = vtophys(mtod(m, vm_offset_t));
                          f->xl_len = m->m_len;
                          frag++;
                  }
          }
  
          c->xl_mbuf = m_head;
          c->xl_ptr->xl_frag[frag - 1].xl_len |= XL_LAST_FRAG;
          c->xl_ptr->xl_status = XL_TXSTAT_RND_DEFEAT;
  
          if (m_head->m_pkthdr.csum_flags) {
                  if (m_head->m_pkthdr.csum_flags & CSUM_IP)
                          c->xl_ptr->xl_status |= XL_TXSTAT_IPCKSUM;
                  if (m_head->m_pkthdr.csum_flags & CSUM_TCP)
                          c->xl_ptr->xl_status |= XL_TXSTAT_TCPCKSUM;
                  if (m_head->m_pkthdr.csum_flags & CSUM_UDP)
                          c->xl_ptr->xl_status |= XL_TXSTAT_UDPCKSUM;
          }
          return(0);
  }
  
  static void xl_start_90xB(ifp)
          struct ifnet            *ifp;
  {
          struct xl_softc         *sc;
          struct mbuf             *m_head = NULL;
          struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;
          int                     idx;
  
          sc = ifp->if_softc;
          XL_LOCK(sc);
  
          if (ifp->if_flags & IFF_OACTIVE) {
                  XL_UNLOCK(sc);
                  return;
          }
  
          idx = sc->xl_cdata.xl_tx_prod;
          start_tx = &sc->xl_cdata.xl_tx_chain[idx];
  
          while (sc->xl_cdata.xl_tx_chain[idx].xl_mbuf == NULL) {
  
                  if ((XL_TX_LIST_CNT - sc->xl_cdata.xl_tx_cnt) < 3) {
                          ifp->if_flags |= IFF_OACTIVE;
                          break;
                  }
  
                  IF_DEQUEUE(&ifp->if_snd, m_head);
                  if (m_head == NULL)
                          break;
  
                  cur_tx = &sc->xl_cdata.xl_tx_chain[idx];
  
                  /* Pack the data into the descriptor. */
                  xl_encap_90xB(sc, cur_tx, m_head);
  
                  /* Chain it together. */
                  if (prev != NULL)
                          prev->xl_ptr->xl_next = cur_tx->xl_phys;
                  prev = cur_tx;
  
                  /*
                   * If there's a BPF listener, bounce a copy of this frame
                   * to him.
                   */
                  BPF_MTAP(ifp, cur_tx->xl_mbuf);
  
                  XL_INC(idx, XL_TX_LIST_CNT);
                  sc->xl_cdata.xl_tx_cnt++;
          }
  
          /*
           * If there are no packets queued, bail.
           */
          if (cur_tx == NULL) {
                  XL_UNLOCK(sc);
                  return;
          }
  
          /*
           * Place the request for the upload interrupt
           * in the last descriptor in the chain. This way, if
           * we're chaining several packets at once, we'll only
           * get an interupt once for the whole chain rather than
           * once for each packet.
           */
          cur_tx->xl_ptr->xl_status |= XL_TXSTAT_DL_INTR;
  
          /* Start transmission */
          sc->xl_cdata.xl_tx_prod = idx;
          start_tx->xl_prev->xl_ptr->xl_next = start_tx->xl_phys;
  
          /*
           * Set a timeout in case the chip goes out to lunch.
           */
          ifp->if_timer = 5;
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  static void
  xl_init(xsc)
          void                    *xsc;
  {
          struct xl_softc         *sc = xsc;
          struct ifnet            *ifp = &sc->arpcom.ac_if;
          int                     i;
          u_int16_t               rxfilt = 0;
          struct mii_data         *mii = NULL;
  
          XL_LOCK(sc);
  
          /*
           * Cancel pending I/O and free all RX/TX buffers.
           */
          xl_stop(sc);
  
          if (sc->xl_miibus == NULL) {
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
                  xl_wait(sc);
          }
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
          xl_wait(sc);
          DELAY(10000);
  
          if (sc->xl_miibus != NULL)
                  mii = device_get_softc(sc->xl_miibus);
  
          /* Init our MAC address */
          XL_SEL_WIN(2);
          for (i = 0; i < ETHER_ADDR_LEN; i++) {
                  CSR_WRITE_1(sc, XL_W2_STATION_ADDR_LO + i,
                                  sc->arpcom.ac_enaddr[i]);
          }
  
          /* Clear the station mask. */
          for (i = 0; i < 3; i++)
                  CSR_WRITE_2(sc, XL_W2_STATION_MASK_LO + (i * 2), 0);
  #ifdef notdef
          /* Reset TX and RX. */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
          xl_wait(sc);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
          xl_wait(sc);
  #endif
          /* Init circular RX list. */
          if (xl_list_rx_init(sc) == ENOBUFS) {
                  printf("xl%d: initialization failed: no "
                          "memory for rx buffers\n", sc->xl_unit);
                  xl_stop(sc);
                  XL_UNLOCK(sc);
                  return;
          }
  
          /* Init TX descriptors. */
          if (sc->xl_type == XL_TYPE_905B)
                  xl_list_tx_init_90xB(sc);
          else
                  xl_list_tx_init(sc);
  
          /*
           * Set the TX freethresh value.
           * Note that this has no effect on 3c905B "cyclone"
           * cards but is required for 3c900/3c905 "boomerang"
           * cards in order to enable the download engine.
           */
          CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);
  
          /* Set the TX start threshold for best performance. */
          sc->xl_tx_thresh = XL_MIN_FRAMELEN;
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_SET_START|sc->xl_tx_thresh);
  
          /*
           * If this is a 3c905B, also set the tx reclaim threshold.
           * This helps cut down on the number of tx reclaim errors
           * that could happen on a busy network. The chip multiplies
           * the register value by 16 to obtain the actual threshold
           * in bytes, so we divide by 16 when setting the value here.
           * The existing threshold value can be examined by reading
           * the register at offset 9 in window 5.
           */
          if (sc->xl_type == XL_TYPE_905B) {
                  CSR_WRITE_2(sc, XL_COMMAND,
                      XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
          }
  
          /* Set RX filter bits. */
          XL_SEL_WIN(5);
          rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
  
          /* Set the individual bit to receive frames for this host only. */
          rxfilt |= XL_RXFILTER_INDIVIDUAL;
  
          /* If we want promiscuous mode, set the allframes bit. */
          if (ifp->if_flags & IFF_PROMISC) {
                  rxfilt |= XL_RXFILTER_ALLFRAMES;
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
          } else {
                  rxfilt &= ~XL_RXFILTER_ALLFRAMES;
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
          }
  
          /*
           * Set capture broadcast bit to capture broadcast frames.
           */
          if (ifp->if_flags & IFF_BROADCAST) {
                  rxfilt |= XL_RXFILTER_BROADCAST;
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
          } else {
                  rxfilt &= ~XL_RXFILTER_BROADCAST;
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_FILT|rxfilt);
          }
  
          /*
           * Program the multicast filter, if necessary.
           */
          if (sc->xl_type == XL_TYPE_905B)
                  xl_setmulti_hash(sc);
          else
                  xl_setmulti(sc);
  
          /*
           * Load the address of the RX list. We have to
           * stall the upload engine before we can manipulate
           * the uplist pointer register, then unstall it when
           * we're finished. We also have to wait for the
           * stall command to complete before proceeding.
           * Note that we have to do this after any RX resets
           * have completed since the uplist register is cleared
           * by a reset.
           */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
          xl_wait(sc);
          CSR_WRITE_4(sc, XL_UPLIST_PTR, vtophys(&sc->xl_ldata->xl_rx_list[0]));
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
          xl_wait(sc);
  
  
          if (sc->xl_type == XL_TYPE_905B) {
                  /* Set polling interval */
                  CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                  /* Load the address of the TX list */
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
                  xl_wait(sc);
                  CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                      vtophys(&sc->xl_ldata->xl_tx_list[0]));
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                  xl_wait(sc);
          }
  
          /*
           * If the coax transceiver is on, make sure to enable
           * the DC-DC converter.
           */
          XL_SEL_WIN(3);
          if (sc->xl_xcvr == XL_XCVR_COAX)
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
          else
                  CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
  
          /* increase packet size to allow reception of 802.1q or ISL packets */
          if (sc->xl_type == XL_TYPE_905B) 
                  CSR_WRITE_2(sc, XL_W3_MAXPKTSIZE, XL_PACKET_SIZE);
          /* Clear out the stats counters. */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
          sc->xl_stats_no_timeout = 1;
          xl_stats_update(sc);
          sc->xl_stats_no_timeout = 0;
          XL_SEL_WIN(4);
          CSR_WRITE_2(sc, XL_W4_NET_DIAG, XL_NETDIAG_UPPER_BYTES_ENABLE);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_ENABLE);
  
          /*
           * Enable interrupts.
           */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|0xFF);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|XL_INTRS);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|XL_INTRS);
          if (sc->xl_flags & XL_FLAG_FUNCREG)
              bus_space_write_4(sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);
  
          /* Set the RX early threshold */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_THRESH|(XL_PACKET_SIZE >>2));
          CSR_WRITE_2(sc, XL_DMACTL, XL_DMACTL_UP_RX_EARLY);
  
          /* Enable receiver and transmitter. */
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
          xl_wait(sc);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_ENABLE);
          xl_wait(sc);
  
          if (mii != NULL)
                  mii_mediachg(mii);
  
          /* Select window 7 for normal operations. */
          XL_SEL_WIN(7);
  
          ifp->if_flags |= IFF_RUNNING;
          ifp->if_flags &= ~IFF_OACTIVE;
  
          sc->xl_stat_ch = timeout(xl_stats_update, sc, hz);
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  /*
   * Set media options.
   */
  static int
  xl_ifmedia_upd(ifp)
          struct ifnet            *ifp;
  {
          struct xl_softc         *sc;
          struct ifmedia          *ifm = NULL;
          struct mii_data         *mii = NULL;
  
          sc = ifp->if_softc;
          if (sc->xl_miibus != NULL)
                  mii = device_get_softc(sc->xl_miibus);
          if (mii == NULL)
                  ifm = &sc->ifmedia;
          else
                  ifm = &mii->mii_media;
  
          switch(IFM_SUBTYPE(ifm->ifm_media)) {
          case IFM_100_FX:
          case IFM_10_FL:
          case IFM_10_2:
          case IFM_10_5:
                  xl_setmode(sc, ifm->ifm_media);
                  return(0);
                  break;
          default:
                  break;
          }
  
          if (sc->xl_media & XL_MEDIAOPT_MII || sc->xl_media & XL_MEDIAOPT_BTX
                  || sc->xl_media & XL_MEDIAOPT_BT4) {
                  xl_init(sc);
          } else {
                  xl_setmode(sc, ifm->ifm_media);
          }
  
          return(0);
  }
  
  /*
   * Report current media status.
   */
  static void
  xl_ifmedia_sts(ifp, ifmr)
          struct ifnet            *ifp;
          struct ifmediareq       *ifmr;
  {
          struct xl_softc         *sc;
          u_int32_t               icfg;
          struct mii_data         *mii = NULL;
  
          sc = ifp->if_softc;
          if (sc->xl_miibus != NULL)
                  mii = device_get_softc(sc->xl_miibus);
  
          XL_SEL_WIN(3);
          icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG) & XL_ICFG_CONNECTOR_MASK;
          icfg >>= XL_ICFG_CONNECTOR_BITS;
  
          ifmr->ifm_active = IFM_ETHER;
  
          switch(icfg) {
          case XL_XCVR_10BT:
                  ifmr->ifm_active = IFM_ETHER|IFM_10_T;
                  if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                          ifmr->ifm_active |= IFM_FDX;
                  else
                          ifmr->ifm_active |= IFM_HDX;
                  break;
          case XL_XCVR_AUI:
                  if (sc->xl_type == XL_TYPE_905B &&
                      sc->xl_media == XL_MEDIAOPT_10FL) {
                          ifmr->ifm_active = IFM_ETHER|IFM_10_FL;
                          if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                                  ifmr->ifm_active |= IFM_FDX;
                          else
                                  ifmr->ifm_active |= IFM_HDX;
                  } else
                          ifmr->ifm_active = IFM_ETHER|IFM_10_5;
                  break;
          case XL_XCVR_COAX:
                  ifmr->ifm_active = IFM_ETHER|IFM_10_2;
                  break;
          /*
           * XXX MII and BTX/AUTO should be separate cases.
           */
  
          case XL_XCVR_100BTX:
          case XL_XCVR_AUTO:
          case XL_XCVR_MII:
                  if (mii != NULL) {
                          mii_pollstat(mii);
                          ifmr->ifm_active = mii->mii_media_active;
                          ifmr->ifm_status = mii->mii_media_status;
                  }
                  break;
          case XL_XCVR_100BFX:
                  ifmr->ifm_active = IFM_ETHER|IFM_100_FX;
                  break;
          default:
                  printf("xl%d: unknown XCVR type: %d\n", sc->xl_unit, icfg);
                  break;
          }
  
          return;
  }
  
  static int
  xl_ioctl(ifp, command, data)
          struct ifnet            *ifp;
          u_long                  command;
          caddr_t                 data;
  {
          struct xl_softc         *sc = ifp->if_softc;
          struct ifreq            *ifr = (struct ifreq *) data;
          int                     error = 0;
          struct mii_data         *mii = NULL;
          u_int8_t                rxfilt;
  
          XL_LOCK(sc);
  
          switch(command) {
          case SIOCSIFFLAGS:
                  XL_SEL_WIN(5);
                  rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
                  if (ifp->if_flags & IFF_UP) {
                          if (ifp->if_flags & IFF_RUNNING &&
                              ifp->if_flags & IFF_PROMISC &&
                              !(sc->xl_if_flags & IFF_PROMISC)) {
                                  rxfilt |= XL_RXFILTER_ALLFRAMES;
                                  CSR_WRITE_2(sc, XL_COMMAND,
                                      XL_CMD_RX_SET_FILT|rxfilt);
                                  XL_SEL_WIN(7);
                          } else if (ifp->if_flags & IFF_RUNNING &&
                              !(ifp->if_flags & IFF_PROMISC) &&
                              sc->xl_if_flags & IFF_PROMISC) {
                                  rxfilt &= ~XL_RXFILTER_ALLFRAMES;
                                  CSR_WRITE_2(sc, XL_COMMAND,
                                      XL_CMD_RX_SET_FILT|rxfilt);
                                  XL_SEL_WIN(7);
                          } else
                                  xl_init(sc);
                  } else {
                          if (ifp->if_flags & IFF_RUNNING)
                                  xl_stop(sc);
                  }
                  sc->xl_if_flags = ifp->if_flags;
                  error = 0;
                  break;
          case SIOCADDMULTI:
          case SIOCDELMULTI:
                  if (sc->xl_type == XL_TYPE_905B)
                          xl_setmulti_hash(sc);
                  else
                          xl_setmulti(sc);
                  error = 0;
                  break;
          case SIOCGIFMEDIA:
          case SIOCSIFMEDIA:
                  if (sc->xl_miibus != NULL)
                          mii = device_get_softc(sc->xl_miibus);
                  if (mii == NULL)
                          error = ifmedia_ioctl(ifp, ifr,
                              &sc->ifmedia, command);
                  else
                          error = ifmedia_ioctl(ifp, ifr,
                              &mii->mii_media, command);
                  break;
          default:
                  error = ether_ioctl(ifp, command, data);
                  break;
          }
  
          XL_UNLOCK(sc);
  
          return(error);
  }
  
  static void
  xl_watchdog(ifp)
          struct ifnet            *ifp;
  {
          struct xl_softc         *sc;
          u_int16_t               status = 0;
  
          sc = ifp->if_softc;
  
          XL_LOCK(sc);
  
          ifp->if_oerrors++;
          XL_SEL_WIN(4);
          status = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
          printf("xl%d: watchdog timeout\n", sc->xl_unit);
  
          if (status & XL_MEDIASTAT_CARRIER)
                  printf("xl%d: no carrier - transceiver cable problem?\n",
                                                                  sc->xl_unit);
          xl_txeoc(sc);
          xl_txeof(sc);
          xl_rxeof(sc);
          xl_reset(sc);
          xl_init(sc);
  
          if (ifp->if_snd.ifq_head != NULL)
                  (*ifp->if_start)(ifp);
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  /*
   * Stop the adapter and free any mbufs allocated to the
   * RX and TX lists.
   */
  static void
  xl_stop(sc)
          struct xl_softc         *sc;
  {
          register int            i;
          struct ifnet            *ifp;
  
          XL_LOCK(sc);
  
          ifp = &sc->arpcom.ac_if;
          ifp->if_timer = 0;
  
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISABLE);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISCARD);
          xl_wait(sc);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_DISABLE);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
          DELAY(800);
  
  #ifdef foo
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
          xl_wait(sc);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
          xl_wait(sc);
  #endif
  
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|XL_STAT_INTLATCH);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|0);
          CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|0);
          if (sc->xl_flags & XL_FLAG_FUNCREG) bus_space_write_4 (sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);
  
          /* Stop the stats updater. */
          untimeout(xl_stats_update, sc, sc->xl_stat_ch);
  
          /*
           * Free data in the RX lists.
           */
          for (i = 0; i < XL_RX_LIST_CNT; i++) {
                  if (sc->xl_cdata.xl_rx_chain[i].xl_mbuf != NULL) {
                          m_freem(sc->xl_cdata.xl_rx_chain[i].xl_mbuf);
                          sc->xl_cdata.xl_rx_chain[i].xl_mbuf = NULL;
                  }
          }
          bzero((char *)&sc->xl_ldata->xl_rx_list,
                  sizeof(sc->xl_ldata->xl_rx_list));
          /*
           * Free the TX list buffers.
           */
          for (i = 0; i < XL_TX_LIST_CNT; i++) {
                  if (sc->xl_cdata.xl_tx_chain[i].xl_mbuf != NULL) {
                          m_freem(sc->xl_cdata.xl_tx_chain[i].xl_mbuf);
                          sc->xl_cdata.xl_tx_chain[i].xl_mbuf = NULL;
                  }
          }
          bzero((char *)&sc->xl_ldata->xl_tx_list,
                  sizeof(sc->xl_ldata->xl_tx_list));
  
          ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
  
          XL_UNLOCK(sc);
  
          return;
  }
  
  /*
   * Stop all chip I/O so that the kernel's probe routines don't
   * get confused by errant DMAs when rebooting.
   */
  static void
  xl_shutdown(dev)
          device_t                dev;
  {
          struct xl_softc         *sc;
  
          sc = device_get_softc(dev);
  
          XL_LOCK(sc);
          xl_reset(sc);
          xl_stop(sc);
          XL_UNLOCK(sc);
  
          return;
  }
  
  static int
  xl_suspend(dev)
          device_t                dev;
  {
          struct xl_softc         *sc;
  
          sc = device_get_softc(dev);
  
          XL_LOCK(sc);
          xl_stop(sc);
          XL_UNLOCK(sc);
  
          return(0);
  }
  
  static int
  xl_resume(dev)
          device_t                dev;
  {
          struct xl_softc         *sc;
          struct ifnet            *ifp;
  
          sc = device_get_softc(dev);
          XL_LOCK(sc);
          ifp = &sc->arpcom.ac_if;
  
          xl_reset(sc);
          if (ifp->if_flags & IFF_UP)
                  xl_init(sc);
  
          XL_UNLOCK(sc);
          return(0);
  }