/*      $OpenBSD: if_eg.c,v 1.53 2024/08/19 03:08:27 jsg Exp $  */
/*      $NetBSD: if_eg.c,v 1.26 1996/05/12 23:52:27 mycroft Exp $       */

/*
 * Copyright (c) 1993 Dean Huxley <dean@fsa.ca>
 * 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 Dean Huxley.
 * 4. The name of Dean Huxley may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR 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.
 */
/*
 * Support for 3Com 3c505 Etherlink+ card.
 */

/* To do:
 * - multicast
 * - promiscuous
 */
#include "bpfilter.h"

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#include <machine/cpu.h>
#include <machine/intr.h>

#include <dev/isa/isavar.h>
#include <dev/isa/if_egreg.h>
#include <dev/isa/elink.h>

/* for debugging convenience */
#ifdef EGDEBUG
#define DPRINTF(x) printf x
#else
#define DPRINTF(x)
#endif

#define EG_INLEN        10
#define EG_BUFLEN       0x0670

/*
 * Ethernet software status per interface.
 */
struct eg_softc {
        struct device sc_dev;
        void *sc_ih;
        bus_space_tag_t sc_bst;
        bus_space_handle_t sc_bsh;
        struct arpcom sc_arpcom;        /* Ethernet common part */
        u_char  eg_rom_major;           /* Cards ROM version (major number) */ 
        u_char  eg_rom_minor;           /* Cards ROM version (minor number) */ 
        short   eg_ram;                 /* Amount of RAM on the card */
        u_char  eg_pcb[64];             /* Primary Command Block buffer */
        u_char  eg_incount;             /* Number of buffers currently used */
        u_char  *eg_inbuf;              /* Incoming packet buffer */
        u_char  *eg_outbuf;             /* Outgoing packet buffer */
};

int egprobe(struct device *, void *, void *);
void egattach(struct device *, struct device *, void *);

const struct cfattach eg_ca = {
        sizeof(struct eg_softc), egprobe, egattach
};

struct cfdriver eg_cd = {
        NULL, "eg", DV_IFNET
};

int egintr(void *);
void eginit(struct eg_softc *);
int egioctl(struct ifnet *, u_long, caddr_t);
void egrecv(struct eg_softc *);
void egstart(struct ifnet *);
void egwatchdog(struct ifnet *);
void egreset(struct eg_softc *);
void egread(struct eg_softc *, caddr_t, int);
struct mbuf *egget(struct eg_softc *, caddr_t, int);
void egstop(struct eg_softc *);

static __inline void egprintpcb(struct eg_softc *);
static int egoutPCB(struct eg_softc *, u_char);
static int egreadPCBstat(struct eg_softc *, u_char);
static int egreadPCBready(struct eg_softc *);
static int egwritePCB(struct eg_softc *);
static int egreadPCB(struct eg_softc *);

/*
 * Support stuff
 */
        
static __inline void
egprintpcb(struct eg_softc *sc)
{
        int i;
        
        for (i = 0; i < sc->eg_pcb[1] + 2; i++)
                DPRINTF(("pcb[%2d] = %x\n", i, sc->eg_pcb[i]));
}


static int
egoutPCB(struct eg_softc *sc, u_char b)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int i;

        for (i = 0; i < 4000; i++) {
                if (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_HCRE) {
                        bus_space_write_1(bst, bsh, EG_COMMAND, b);
                        return 0;
                }
                delay(10);
        }
        DPRINTF(("egoutPCB failed\n"));
        return (1);
}
        
static int
egreadPCBstat(struct eg_softc *sc, u_char statb)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int i;

        for (i=0; i < 5000; i++) {
                if ((bus_space_read_1(bst, bsh, EG_STATUS) & EG_PCB_STAT) !=
                    EG_PCB_NULL) 
                        break;
                delay(10);
        }
        if ((bus_space_read_1(bst, bsh, EG_STATUS) & EG_PCB_STAT) == statb) 
                return (0);
        return (1);
}

static int
egreadPCBready(struct eg_softc *sc)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int i;

        for (i=0; i < 10000; i++) {
                if (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_ACRF)
                        return (0);
                delay(5);
        }
        DPRINTF(("PCB read not ready status %02x\n",
            bus_space_read_1(bst, bsh, EG_STATUS)));
        return (1);
}
        
static int
egwritePCB(struct eg_softc *sc)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int i;
        u_char len;

        bus_space_write_1(bst, bsh, EG_CONTROL,
            (bus_space_read_1(bst, bsh, EG_CONTROL) & ~EG_PCB_STAT) |
            EG_PCB_NULL);

        len = sc->eg_pcb[1] + 2;
        for (i = 0; i < len; i++)
                egoutPCB(sc, sc->eg_pcb[i]);
        
        for (i=0; i < 4000; i++) {
                if (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_HCRE)
                        break;
                delay(10);
        }

        bus_space_write_1(bst, bsh, EG_CONTROL,
            (bus_space_read_1(bst, bsh, EG_CONTROL) & ~EG_PCB_STAT) |
            EG_PCB_DONE);

        egoutPCB(sc, len);

        if (egreadPCBstat(sc, EG_PCB_ACCEPT))
                return (1);
        return (0);
}       
        
static int
egreadPCB(struct eg_softc *sc)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int i;
        u_char b;
        
        bus_space_write_1(bst, bsh, EG_CONTROL,
            (bus_space_read_1(bst, bsh, EG_CONTROL) & ~EG_PCB_STAT) |
            EG_PCB_NULL);

        bzero(sc->eg_pcb, sizeof(sc->eg_pcb));

        if (egreadPCBready(sc))
                return (1);

        sc->eg_pcb[0] = bus_space_read_1(bst, bsh, EG_COMMAND);
        
        if (egreadPCBready(sc))
                return (1);

        sc->eg_pcb[1] = bus_space_read_1(bst, bsh, EG_COMMAND);

        if (sc->eg_pcb[1] > 62) {
                DPRINTF(("len %d too large\n", sc->eg_pcb[1]));
                return (1);
        }
        
        for (i = 0; i < sc->eg_pcb[1]; i++) {
                if (egreadPCBready(sc))
                        return (1);
                sc->eg_pcb[2+i] = bus_space_read_1(bst, bsh, EG_COMMAND);
        }
        if (egreadPCBready(sc))
                return (1);
        if (egreadPCBstat(sc, EG_PCB_DONE))
                return (1);
        if ((b = bus_space_read_1(bst, bsh, EG_COMMAND)) != sc->eg_pcb[1] + 2) {
                DPRINTF(("%d != %d\n", b, sc->eg_pcb[1] + 2));
                return (1);
        }

        bus_space_write_1(bst, bsh, EG_CONTROL,
            (bus_space_read_1(bst, bsh, EG_CONTROL) & ~EG_PCB_STAT) |
            EG_PCB_ACCEPT);

        return (0);
}       

/*
 * Real stuff
 */

int
egprobe(struct device *parent, void *match, void *aux)
{
        struct eg_softc *sc = match;
        struct isa_attach_args *ia = aux;
        bus_space_tag_t bst = sc->sc_bst = ia->ia_iot;
        bus_space_handle_t bsh;
        int i;

        if ((ia->ia_iobase & ~0x07f0) != 0) {
                DPRINTF(("Weird iobase %x\n", ia->ia_iobase));
                return (0);
        }
        
        if (bus_space_map(bst, ia->ia_iobase, EG_IO_PORTS, 0, &bsh)) {
                DPRINTF(("%s: can't map i/o space\n", sc->sc_dev.dv_xname));
                return (0);
        }
        sc->sc_bsh = bsh;

        /* hard reset card */
        bus_space_write_1(bst, bsh, EG_CONTROL, EG_CTL_RESET); 
        bus_space_write_1(bst, bsh, EG_CONTROL, 0);
        for (i = 0; i < 5000; i++) {
                delay(1000);
                if ((bus_space_read_1(bst, bsh, EG_STATUS) & EG_PCB_STAT) ==
                    EG_PCB_NULL) 
                        break;
        }
        if ((bus_space_read_1(bst, bsh, EG_STATUS) & EG_PCB_STAT) !=
            EG_PCB_NULL) {
                DPRINTF(("eg: Reset failed\n"));
                goto lose;
        }
        sc->eg_pcb[0] = EG_CMD_GETINFO; /* Get Adapter Info */
        sc->eg_pcb[1] = 0;
        if (egwritePCB(sc) != 0)
                goto lose;
        
        if (egreadPCB(sc) != 0) {
                egprintpcb(sc);
                goto lose;
        }

        if (sc->eg_pcb[0] != EG_RSP_GETINFO || /* Get Adapter Info Response */
            sc->eg_pcb[1] != 0x0a) {
                egprintpcb(sc);
                goto lose;
        }
        sc->eg_rom_major = sc->eg_pcb[3];
        sc->eg_rom_minor = sc->eg_pcb[2];
        sc->eg_ram = sc->eg_pcb[6] | (sc->eg_pcb[7] << 8);
        
        ia->ia_iosize = 0x08;
        ia->ia_msize = 0;
        bus_space_unmap(bst, bsh, EG_IO_PORTS);
        return (1);

lose:
        bus_space_unmap(bst, bsh, EG_IO_PORTS);
        return (0);
}

void
egattach(struct device *parent, struct device *self, void *aux)
{
        struct eg_softc *sc = (void *)self;
        struct isa_attach_args *ia = aux;
        bus_space_tag_t bst = sc->sc_bst = ia->ia_iot;
        bus_space_handle_t bsh;
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        
        if (bus_space_map(bst, ia->ia_iobase, EG_IO_PORTS, 0, &bsh)) {
                printf("%s: can't map i/o space\n", sc->sc_dev.dv_xname);
                return;
        }
        sc->sc_bsh = bsh;

        egstop(sc);

        sc->eg_pcb[0] = EG_CMD_GETEADDR; /* Get Station address */
        sc->eg_pcb[1] = 0;
        if (egwritePCB(sc) != 0) {
                DPRINTF(("write error\n"));
                return;
        }       
        if (egreadPCB(sc) != 0) {
                DPRINTF(("read error\n"));
                egprintpcb(sc);
                return;
        }

        /* check Get station address response */
        if (sc->eg_pcb[0] != EG_RSP_GETEADDR || sc->eg_pcb[1] != 0x06) { 
                DPRINTF(("parse error\n"));
                egprintpcb(sc);
                return;
        }
        bcopy(&sc->eg_pcb[2], sc->sc_arpcom.ac_enaddr, ETHER_ADDR_LEN);

        printf(": ROM v%d.%02d %dk address %s\n",
            sc->eg_rom_major, sc->eg_rom_minor, sc->eg_ram,
            ether_sprintf(sc->sc_arpcom.ac_enaddr));

        sc->eg_pcb[0] = EG_CMD_SETEADDR; /* Set station address */
        if (egwritePCB(sc) != 0) {
                DPRINTF(("write error2\n"));
                return;
        }
        if (egreadPCB(sc) != 0) {
                DPRINTF(("read error2\n"));
                egprintpcb(sc);
                return;
        }
        if (sc->eg_pcb[0] != EG_RSP_SETEADDR || sc->eg_pcb[1] != 0x02 ||
            sc->eg_pcb[2] != 0 || sc->eg_pcb[3] != 0) {
                DPRINTF(("parse error2\n"));
                egprintpcb(sc);
                return;
        }

        /* Initialize ifnet structure. */
        bcopy(sc->sc_dev.dv_xname, ifp->if_xname, IFNAMSIZ);
        ifp->if_softc = sc;
        ifp->if_start = egstart;
        ifp->if_ioctl = egioctl;
        ifp->if_watchdog = egwatchdog;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
        
        /* Now we can attach the interface. */
        if_attach(ifp);
        ether_ifattach(ifp);
        
        sc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq, IST_EDGE,
            IPL_NET, egintr, sc, sc->sc_dev.dv_xname);
}

void
eginit(register struct eg_softc *sc)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        register struct ifnet *ifp = &sc->sc_arpcom.ac_if;

        /* soft reset the board */
        bus_space_write_1(bst, bsh, EG_CONTROL, EG_CTL_FLSH);
        delay(100);
        bus_space_write_1(bst, bsh, EG_CONTROL, EG_CTL_ATTN);
        delay(100);
        bus_space_write_1(bst, bsh, EG_CONTROL, 0);
        delay(200);

        sc->eg_pcb[0] = EG_CMD_CONFIG82586; /* Configure 82586 */
        sc->eg_pcb[1] = 2;
        sc->eg_pcb[2] = 3; /* receive broadcast & multicast */
        sc->eg_pcb[3] = 0;
        if (egwritePCB(sc) != 0)
                DPRINTF(("write error3\n"));

        if (egreadPCB(sc) != 0) {
                DPRINTF(("read error3\n"));
                egprintpcb(sc);
        } else if (sc->eg_pcb[2] != 0 || sc->eg_pcb[3] != 0)
                printf("%s: configure card command failed\n",
                    sc->sc_dev.dv_xname);

        if (sc->eg_inbuf == NULL)
                sc->eg_inbuf = malloc(EG_BUFLEN, M_TEMP, M_NOWAIT);
        sc->eg_incount = 0;

        if (sc->eg_outbuf == NULL)
                sc->eg_outbuf = malloc(EG_BUFLEN, M_TEMP, M_NOWAIT);

        bus_space_write_1(bst, bsh, EG_CONTROL, EG_CTL_CMDE);

        sc->eg_incount = 0;
        egrecv(sc);

        /* Interface is now `running', with no output active. */
        ifp->if_flags |= IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);

        /* Attempt to start output, if any. */
        egstart(ifp);
}

void
egrecv(struct eg_softc *sc)
{
        while (sc->eg_incount < EG_INLEN) {
                sc->eg_pcb[0] = EG_CMD_RECVPACKET;
                sc->eg_pcb[1] = 0x08;
                sc->eg_pcb[2] = 0; /* address not used.. we send zero */
                sc->eg_pcb[3] = 0;
                sc->eg_pcb[4] = 0;
                sc->eg_pcb[5] = 0;
                sc->eg_pcb[6] = EG_BUFLEN & 0xff; /* our buffer size */
                sc->eg_pcb[7] = (EG_BUFLEN >> 8) & 0xff;
                sc->eg_pcb[8] = 0; /* timeout, 0 == none */
                sc->eg_pcb[9] = 0;
                if (egwritePCB(sc) != 0)
                        break;
                sc->eg_incount++;
        }
}

void
egstart(struct ifnet *ifp)
{
        struct eg_softc *sc = ifp->if_softc;
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        struct mbuf *m0, *m;
        caddr_t buffer;
        int len;
        u_short *ptr;
        u_int i;

        /* Don't transmit if interface is busy or not running */
        if (!(ifp->if_flags & IFF_RUNNING) || ifq_is_oactive(&ifp->if_snd))
                return;

loop:
        /* Dequeue the next datagram. */
        m0 = ifq_dequeue(&ifp->if_snd);
        if (m0 == NULL)
                return;
        
        ifq_set_oactive(&ifp->if_snd);

        /* We need to use m->m_pkthdr.len, so require the header */
        if ((m0->m_flags & M_PKTHDR) == 0)
                panic("egstart: no header mbuf");
        len = max(m0->m_pkthdr.len, ETHER_MIN_LEN);

#if NBPFILTER > 0
        if (ifp->if_bpf)
                bpf_mtap(ifp->if_bpf, m0, BPF_DIRECTION_OUT);
#endif

        sc->eg_pcb[0] = EG_CMD_SENDPACKET;
        sc->eg_pcb[1] = 0x06;
        sc->eg_pcb[2] = 0; /* address not used, we send zero */
        sc->eg_pcb[3] = 0;
        sc->eg_pcb[4] = 0;
        sc->eg_pcb[5] = 0;
        sc->eg_pcb[6] = len; /* length of packet */
        sc->eg_pcb[7] = len >> 8;
        if (egwritePCB(sc) != 0) {
                DPRINTF(("egwritePCB in egstart failed\n"));
                ifp->if_oerrors++;
                ifq_clr_oactive(&ifp->if_snd);
                m_freem(m0);
                goto loop;
        }

        buffer = sc->eg_outbuf;
        for (m = m0; m != 0; m = m->m_next) {
                bcopy(mtod(m, caddr_t), buffer, m->m_len);
                buffer += m->m_len;
        }
        if (len > m0->m_pkthdr.len)
                bzero(buffer, len - m0->m_pkthdr.len);

        /* set direction bit: host -> adapter */
        bus_space_write_1(bst, bsh, EG_CONTROL,
            bus_space_read_1(bst, bsh, EG_CONTROL) & ~EG_CTL_DIR); 
        
        for (ptr = (u_short *)sc->eg_outbuf; len > 0; len -= 2) {
                bus_space_write_2(bst, bsh, EG_DATA, *ptr++);
                for (i = 10000; i != 0; i--) {
                        if (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_HRDY)
                                break;
                        delay(10);
                }
                if (i == 0) {
                        printf("%s: start failed\n", sc->sc_dev.dv_xname);
                        break;
                }
        }
        
        m_freem(m0);
}

int
egintr(void *arg)
{
        struct eg_softc *sc = arg;
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        int ret = 0;
        int i, len;
        u_short *ptr;

        while (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_ACRF) {
                ret = 1;
                egreadPCB(sc);
                switch (sc->eg_pcb[0]) {
                case EG_RSP_RECVPACKET:
                        len = sc->eg_pcb[6] | (sc->eg_pcb[7] << 8);
        
                        /* Set direction bit : Adapter -> host */
                        bus_space_write_1(bst, bsh, EG_CONTROL,
                            bus_space_read_1(bst, bsh, EG_CONTROL) |
                            EG_CTL_DIR); 

                        for (ptr = (u_short *)sc->eg_inbuf; len > 0; len -= 2) {
                                for (i = 10000; i != 0; i--) {
                                        if (bus_space_read_1(bst, bsh, EG_STATUS) & EG_STAT_HRDY)
                                                break;
                                        delay(10);
                                }
                                if (i == 0) {
                                        printf("%s: receive failed\n",
                                            sc->sc_dev.dv_xname);
                                        break;
                                }
                                *ptr++ = bus_space_read_2(bst, bsh, EG_DATA);
                        }

                        if (len <= 0) {
                                len = sc->eg_pcb[8] | (sc->eg_pcb[9] << 8);
                                egread(sc, sc->eg_inbuf, len);

                                sc->eg_incount--;
                                egrecv(sc);
                        }
                        break;

                case EG_RSP_SENDPACKET:
                        if (sc->eg_pcb[6] || sc->eg_pcb[7]) {
                                DPRINTF(("packet dropped\n"));
                                sc->sc_arpcom.ac_if.if_oerrors++;
                        }
                        sc->sc_arpcom.ac_if.if_collisions +=
                            sc->eg_pcb[8] & 0xf;
                        ifq_clr_oactive(&sc->sc_arpcom.ac_if.if_snd);
                        egstart(&sc->sc_arpcom.ac_if);
                        break;

                case EG_RSP_GETSTATS:
                        DPRINTF(("Card Statistics\n"));
                        bcopy(&sc->eg_pcb[2], &i, sizeof(i));
                        DPRINTF(("Receive Packets %d\n", i));
                        bcopy(&sc->eg_pcb[6], &i, sizeof(i));
                        DPRINTF(("Transmit Packets %d\n", i));
                        DPRINTF(("CRC errors %d\n", *(short *)&sc->eg_pcb[10]));
                        DPRINTF(("alignment errors %d\n",
                            *(short *)&sc->eg_pcb[12]));
                        DPRINTF(("no resources errors %d\n",
                            *(short *)&sc->eg_pcb[14]));
                        DPRINTF(("overrun errors %d\n",
                            *(short *)&sc->eg_pcb[16]));
                        break;
                        
                default:
                        DPRINTF(("egintr: Unknown response %x??\n",
                            sc->eg_pcb[0]));
                        egprintpcb(sc);
                        break;
                }
        }

        return (ret);
}

/*
 * Pass a packet up to the higher levels.
 */
void
egread(struct eg_softc *sc, caddr_t buf, int len)
{
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        struct mbuf_list ml = MBUF_LIST_INITIALIZER();
        struct mbuf *m;

        if (len <= sizeof(struct ether_header) ||
            len > ETHER_MAX_LEN) {
                printf("%s: invalid packet size %d; dropping\n",
                    sc->sc_dev.dv_xname, len);
                ifp->if_ierrors++;
                return;
        }

        /* Pull packet off interface. */
        m = egget(sc, buf, len);
        if (m == NULL) {
                ifp->if_ierrors++;
                return;
        }

        ml_enqueue(&ml, m);
        if_input(ifp, &ml);
}

/*
 * convert buf into mbufs
 */
struct mbuf *
egget(struct eg_softc *sc, caddr_t buf, int totlen)
{
        struct mbuf *top, **mp, *m;
        int len;

        MGETHDR(m, M_DONTWAIT, MT_DATA);
        if (m == NULL)
                return (0);
        m->m_pkthdr.len = totlen;
        len = MHLEN;
        top = 0;
        mp = &top;

        while (totlen > 0) {
                if (top) {
                        MGET(m, M_DONTWAIT, MT_DATA);
                        if (m == NULL) {
                                m_freem(top);
                                return (0);
                        }
                        len = MLEN;
                }
                if (totlen >= MINCLSIZE) {
                        MCLGET(m, M_DONTWAIT);
                        if (m->m_flags & M_EXT)
                                len = MCLBYTES;
                }
                m->m_len = len = min(totlen, len);
                bcopy((caddr_t)buf, mtod(m, caddr_t), len);
                buf += len;
                totlen -= len;
                *mp = m;
                mp = &m->m_next;
        }

        return (top);
}

int
egioctl(register struct ifnet *ifp, u_long cmd, caddr_t data)
{
        struct eg_softc *sc = ifp->if_softc;
        int s, error = 0;

        s = splnet();

        switch (cmd) {
        case SIOCSIFADDR:
                ifp->if_flags |= IFF_UP;
                eginit(sc);
                break;

        case SIOCSIFFLAGS:
                if ((ifp->if_flags & IFF_UP) == 0 &&
                    (ifp->if_flags & IFF_RUNNING) != 0) {
                        /*
                         * If interface is marked down and it is running, then
                         * stop it.
                         */
                        egstop(sc);
                        ifp->if_flags &= ~IFF_RUNNING;
                } else if ((ifp->if_flags & IFF_UP) != 0 &&
                           (ifp->if_flags & IFF_RUNNING) == 0) {
                        /*
                         * If interface is marked up and it is stopped, then
                         * start it.
                         */
                        eginit(sc);
                } else {
                        sc->eg_pcb[0] = EG_CMD_GETSTATS;
                        sc->eg_pcb[1] = 0;
                        if (egwritePCB(sc) != 0)
                                DPRINTF(("write error\n"));
                        /*
                         * XXX deal with flags changes:
                         * IFF_MULTICAST, IFF_PROMISC,
                         * IFF_LINK0, IFF_LINK1,
                         */
                }
                break;

        default:
                error = ether_ioctl(ifp, &sc->sc_arpcom, cmd, data);
        }

        splx(s);
        return (error);
}

void
egreset(struct eg_softc *sc)
{
        int s;

        DPRINTF(("egreset()\n"));
        s = splnet();
        egstop(sc);
        eginit(sc);
        splx(s);
}

void
egwatchdog(struct ifnet *ifp)
{
        struct eg_softc *sc = ifp->if_softc;

        log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
        sc->sc_arpcom.ac_if.if_oerrors++;

        egreset(sc);
}

void
egstop(register struct eg_softc *sc)
{
        bus_space_tag_t bst = sc->sc_bst;
        bus_space_handle_t bsh = sc->sc_bsh;
        
        bus_space_write_1(bst, bsh, EG_CONTROL, 0);
}