am7990.c

很好的一个嵌入式linux平台下的bootloader

	if (tlen < LEMINSIZE) {
		(*sc->sc_zerobuf)(sc, boff, LEMINSIZE - tlen);
		tlen = LEMINSIZE;
	}
	return (tlen);
}

/*
 * Pull data off an interface.
 * Len is length of data, with local net header stripped.
 * We copy the data into mbufs.  When full cluster sized units are present
 * we copy into clusters.
 */
integrate struct mbuf *
am7990_get(sc, boff, totlen)
	struct am7990_softc *sc;
	int boff, totlen;
{
	register struct mbuf *m;
	struct mbuf *top, **mp;
	int len, pad;

	MGETHDR(m, M_DONTWAIT, MT_DATA);
	if (m == 0)
		return (0);
	m->m_pkthdr.rcvif = ifp;
	m->m_pkthdr.len = totlen;
	pad = ALIGN(sizeof(struct ether_header)) - sizeof(struct ether_header);
	m->m_data += pad;
	len = MHLEN - pad;
	top = 0;
	mp = &top;

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

	return (top);
}

/*
 * Pass a packet to the higher levels.
 */
integrate void
am7990_read(sc, boff, len)
	register struct am7990_softc *sc;
	int boff, len;
{
	struct mbuf *m;
	struct ether_header *eh;

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

	/* Pull packet off interface. */
	m = am7990_get(sc, boff, len);
	if (m == 0) {
		ifp->if_ierrors++;
		return;
	}

	ifp->if_ipackets++;

	/* We assume that the header fit entirely in one mbuf. */
	eh = mtod(m, struct ether_header *);

#if NBPFILTER > 0
	/*
	 * Check if there's a BPF listener on this interface.
	 * If so, hand off the raw packet to BPF.
	 */
	if (ifp->if_bpf)
		bpf_mtap(ifp->if_bpf, m);
#endif

#ifdef LANCE_REVC_BUG
	/*
	 * The old LANCE (Rev. C) chips have a bug which causes
	 * garbage to be inserted in front of the received packet.
	 * The work-around is to ignore packets with an invalid
	 * destination address (garbage will usually not match).
	 * Of course, this precludes multicast support...
	 */
	if (ETHER_CMP(eh->ether_dhost, sc->sc_arpcom.ac_enaddr) &&
	    ETHER_CMP(eh->ether_dhost, etherbroadcastaddr)) {
		m_freem(m);
		return;
	}
#endif

#if defined(__bsdi__) || defined(PROM)
	eh->ether_type = ntohs(eh->ether_type);
#endif

	/* Pass the packet up, with the ether header sort-of removed. */
	m_adj(m, sizeof(struct ether_header));
	ether_input(ifp, eh, m);
}

integrate void
am7990_rint(sc)
	struct am7990_softc *sc;
{
	register int bix;
	int rp;
	struct lermd rmd;

	bix = sc->sc_last_rd;

	/* Process all buffers with valid data. */
	for (;;) {
		rp = LE_RMDADDR(sc, bix);
		(*sc->sc_copyfromdesc)(sc, &rmd, rp, sizeof(rmd));

		if (rmd.rmd1_bits & LE_R1_OWN)
			break;

		if (rmd.rmd1_bits & LE_R1_ERR) {
			if (rmd.rmd1_bits & LE_R1_ENP) {
#ifdef LEDEBUG
				if ((rmd.rmd1_bits & LE_R1_OFLO) == 0) {
					if (rmd.rmd1_bits & LE_R1_FRAM)
						printf("%s: framing error\n",
						    sc->sc_dev.dv_xname);
					if (rmd.rmd1_bits & LE_R1_CRC)
						printf("%s: crc mismatch\n",
						    sc->sc_dev.dv_xname);
				}
#endif
			} else {
				if (rmd.rmd1_bits & LE_R1_OFLO)
					printf("%s: overflow\n",
					    sc->sc_dev.dv_xname);
			}
			if (rmd.rmd1_bits & LE_R1_BUFF)
				printf("%s: receive buffer error\n",
				    sc->sc_dev.dv_xname);
			ifp->if_ierrors++;
		} else if ((rmd.rmd1_bits & (LE_R1_STP | LE_R1_ENP)) !=
		    (LE_R1_STP | LE_R1_ENP)) {
			printf("%s: dropping chained buffer\n",
			    sc->sc_dev.dv_xname);
			ifp->if_ierrors++;
		} else {
#ifdef LEDEBUG
			if (sc->sc_debug)
				am7990_recv_print(sc, sc->sc_last_rd);
#endif
			am7990_read(sc, LE_RBUFADDR(sc, bix),
			    (int)mtohs(rmd.rmd3) - 4);
		}

		rmd.rmd1_bits = LE_R1_OWN;
		rmd.rmd2 = htoms(-LEBLEN | LE_XMD2_ONES);
		rmd.rmd3 = htoms(0);
		(*sc->sc_copytodesc)(sc, &rmd, rp, sizeof(rmd));

#ifdef LEDEBUG
		if (sc->sc_debug)
			printf("sc->sc_last_rd = %x, rmd: "
			       "ladr %04x, hadr %02x, flags %02x, "
			       "bcnt %04x, mcnt %04x\n",
				sc->sc_last_rd,
				rmd.rmd0, rmd.rmd1_hadr, rmd.rmd1_bits,
				rmd.rmd2, rmd.rmd3);
#endif

		if (++bix == sc->sc_nrbuf)
			bix = 0;
	}

	sc->sc_last_rd = bix;
}

integrate void
am7990_tint(sc)
	register struct am7990_softc *sc;
{
	register int bix;
	struct letmd tmd;

	bix = sc->sc_first_td;

	for (;;) {
		if (sc->sc_no_td <= 0)
			break;

		(*sc->sc_copyfromdesc)(sc, &tmd, LE_TMDADDR(sc, bix),
		    sizeof(tmd));

#ifdef LEDEBUG
		if (sc->sc_debug)
			printf("trans tmd: "
			    "ladr %04x, hadr %02x, flags %02x, "
			    "bcnt %04x, mcnt %04x\n",
			    tmd.tmd0, tmd.tmd1_hadr, tmd.tmd1_bits,
			    tmd.tmd2, tmd.tmd3);
#endif

		if (tmd.tmd1_bits & LE_T1_OWN)
			break;

		ifp->if_flags &= ~IFF_OACTIVE;

		if (tmd.tmd1_bits & LE_T1_ERR) {
			if (mtohs(tmd.tmd3) & LE_T3_BUFF)
				printf("%s: transmit buffer error\n",
				    sc->sc_dev.dv_xname);
			else if (mtohs(tmd.tmd3) & LE_T3_UFLO)
				printf("%s: underflow\n", sc->sc_dev.dv_xname);
			if (mtohs(tmd.tmd3) & (LE_T3_BUFF | LE_T3_UFLO)) {
				am7990_reset(sc);
				return;
			}
			if (mtohs(tmd.tmd3) & LE_T3_LCAR) {
				if (sc->sc_nocarrier)
					(*sc->sc_nocarrier)(sc);
				else
					printf("%s: lost carrier\n",
					    sc->sc_dev.dv_xname);
			}
			if (mtohs(tmd.tmd3) & LE_T3_LCOL)
				ifp->if_collisions++;
			if (mtohs(tmd.tmd3) & LE_T3_RTRY) {
				printf("%s: excessive collisions, tdr %d\n",
				    sc->sc_dev.dv_xname,
				       mtohs(tmd.tmd3) & LE_T3_TDR_MASK);
				ifp->if_collisions += 16;
			}
			ifp->if_oerrors++;
		} else {
			if (tmd.tmd1_bits & LE_T1_ONE)
				ifp->if_collisions++;
			else if (tmd.tmd1_bits & LE_T1_MORE)
				/* Real number is unknown. */
				ifp->if_collisions += 2;
			ifp->if_opackets++;
		}

		if (++bix == sc->sc_ntbuf)
			bix = 0;

		--sc->sc_no_td;
	}

	sc->sc_first_td = bix;

	am7990_start(ifp);

	if (sc->sc_no_td == 0)
		ifp->if_timer = 0;
}

/*
 * Controller interrupt.
 */
int
am7990_intr(arg)
	register void *arg;
{
	register struct am7990_softc *sc = arg;
	register u_int16_t isr;

	isr = (*sc->sc_rdcsr)(sc, LE_CSR0);
	if ((isr & LE_C0_INTR) == 0)
		return (0);

	(*sc->sc_wrcsr)(sc, LE_CSR0,
	    isr & (LE_C0_INEA | LE_C0_BABL | LE_C0_MISS | LE_C0_MERR |
		   LE_C0_RINT | LE_C0_TINT | LE_C0_IDON));
	if (isr & LE_C0_ERR) {
		if (isr & LE_C0_BABL) {
#ifdef LEDEBUG
			printf("%s: babble\n", sc->sc_dev.dv_xname);
#endif
			ifp->if_oerrors++;
		}
#if 0
		if (isr & LE_C0_CERR) {
			printf("%s: collision error\n", sc->sc_dev.dv_xname);
			ifp->if_collisions++;
		}
#endif
		if (isr & LE_C0_MISS) {
#ifdef LEDEBUG
			printf("%s: missed packet\n", sc->sc_dev.dv_xname);
#endif
			ifp->if_ierrors++;
		}
		if (isr & LE_C0_MERR) {
			printf("%s: memory error\n", sc->sc_dev.dv_xname);
			am7990_reset(sc);
			return (1);
		}
	}

	if ((isr & LE_C0_RXON) == 0) {
		printf("%s: receiver disabled\n", sc->sc_dev.dv_xname);
		ifp->if_ierrors++;
		am7990_reset(sc);
		return (1);
	}
	if ((isr & LE_C0_TXON) == 0) {
		printf("%s: transmitter disabled\n", sc->sc_dev.dv_xname);
		ifp->if_oerrors++;
		am7990_reset(sc);
		return (1);
	}

	if (isr & LE_C0_RINT)
		am7990_rint(sc);
	if (isr & LE_C0_TINT)
		am7990_tint(sc);

	return (1);
}

#undef	ifp

#ifdef PROM
am7990_watchdog(int unit)
#else
am7990_watchdog(struct ifnet *ifp)
#endif
{
#ifdef PROM
        struct am7990_softc *sc = UNIT_TO_SOFTC(unit);
#else
	struct am7990_softc *sc = IFP_TO_SOFTC(ifp);
#endif

	log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
#ifndef PROM
	++ifp->if_oerrors;
#endif
	am7990_reset(sc);
}

/*
 * Setup output on interface.
 * Get another datagram to send off of the interface queue, and map it to the
 * interface before starting the output.
 * Called only at splimp or interrupt level.
 */
ifnet_ret_t
am7990_start(ifp)
	register struct ifnet *ifp;
{
	register struct am7990_softc *sc = IFP_TO_SOFTC(ifp);
	register int bix;
	register struct mbuf *m;
	struct letmd tmd;
	int rp;
	int len;

	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
		return;

#ifdef PROM
	if (!am7990_linkstatus (sc))
	    return;
#endif

	bix = sc->sc_last_td;

	for (;;) {
		rp = LE_TMDADDR(sc, bix);
		(*sc->sc_copyfromdesc)(sc, &tmd, rp, sizeof(tmd));

		if (tmd.tmd1_bits & LE_T1_OWN) {
			ifp->if_flags |= IFF_OACTIVE;
			printf("missing buffer, no_td = %d, last_td = %d\n",
			    sc->sc_no_td, sc->sc_last_td);
		}

		IF_DEQUEUE(&ifp->if_snd, m);
		if (m == 0)
			break;

#if NBPFILTER > 0
		/*
		 * If BPF is listening on this interface, let it see the packet
		 * before we commit it to the wire.
		 */
		if (ifp->if_bpf)
			bpf_mtap(ifp->if_bpf, m);
#endif

		/*
		 * Copy the mbuf chain into the transmit buffer.
		 */
		len = am7990_put(sc, LE_TBUFADDR(sc, bix), m);

#ifdef LEDEBUG
		if (len > ETHERMTU + sizeof(struct ether_header))
			printf("packet length %d\n", len);
#endif

		ifp->if_timer = 5;

		/*
		 * Init transmit registers, and set transmit start flag.
		 */
		tmd.tmd1_bits = LE_T1_OWN | LE_T1_STP | LE_T1_ENP;
		tmd.tmd2 = htoms(-len | LE_XMD2_ONES);
		tmd.tmd3 = htoms(0);

		(*sc->sc_copytodesc)(sc, &tmd, rp, sizeof(tmd));

#ifdef LEDEBUG
		if (sc->sc_debug)
			am7990_xmit_print(sc, sc->sc_last_td);
#endif

		(*sc->sc_wrcsr)(sc, LE_CSR0, LE_C0_INEA | LE_C0_TDMD);

		if (++bix == sc->sc_ntbuf)
			bix = 0;

		if (++sc->sc_no_td == sc->sc_ntbuf) {
			ifp->if_flags |= IFF_OACTIVE;
			break;
		}

	}

	sc->sc_last_td = bix;
}

/*
 * Process an ioctl request.
 */
int
am7990_ioctl(ifp, cmd, data)
	register struct ifnet *ifp;
	u_long cmd;
	caddr_t data;
{
	register struct am7990_softc *sc = IFP_TO_SOFTC(ifp);
	struct ifaddr *ifa = (struct ifaddr *)data;
	struct ifreq *ifr = (struct ifreq *)data;
	int s, error = 0;

	s = splimp();

#ifndef PROM
	if ((error = ether_ioctl(ifp, &sc->sc_arpcom, cmd, data)) > 0) {
		splx(s);
		return error;
	}
#endif

	switch (cmd) {

#ifdef PROM
    case SIOCPOLL:
/*printf ("am7990_iocyl: poll\n");*/
	am7990_intr(sc);
	break;
#endif

	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;