if_ne.c

早期freebsd实现

			m = m_pullup(m, 2);
		} else {
			neput(mtod(m, caddr_t), buffer, m->m_len);
			buffer += m->m_len;
			t -= m->m_len;
			MFREE(m, m0);
			m = m0;
		}
	}

	/*
	 * Init transmit length registers, and set transmit start flag.
	 */

	len = total;
	if (len < ETHER_MIN_LEN) len = ETHER_MIN_LEN;
	outb(nec+ds0_tbcr0,len&0xff);
	outb(nec+ds0_tbcr1,(len>>8)&0xff);
	outb(nec+ds0_tpsr, TBUF/DS_PGSIZE);
	outb(nec+ds_cmd, DSCM_TRANS|DSCM_NODMA|DSCM_START);
}

/* buffer successor/predecessor in ring? */
#define succ(n) (((n)+1 >= RBUFEND/DS_PGSIZE) ? RBUF/DS_PGSIZE : (n)+1)
#define pred(n) (((n)-1 < RBUF/DS_PGSIZE) ? RBUFEND/DS_PGSIZE-1 : (n)-1)

/*
 * Controller interrupt.
 */
neintr(unit)
{
	register struct ne_softc *ns = &ne_softc[unit];
	u_char cmd,isr;

	/* Save cmd, clear interrupt */
	cmd = inb (nec+ds_cmd);
loop:
	isr = inb (nec+ds0_isr);
	outb(nec+ds_cmd,DSCM_NODMA|DSCM_START);
	outb(nec+ds0_isr, isr);

	/* Receiver error */
	if (isr & DSIS_RXE) {
		/* need to read these registers to clear status */
		(void) inb(nec+ ds0_rsr);
		(void) inb(nec+ 0xD);
		(void) inb(nec + 0xE);
		(void) inb(nec + 0xF);
		ns->ns_if.if_ierrors++;
	}

	/* We received something; rummage thru tiny ring buffer */
	if (isr & (DSIS_RX|DSIS_RXE|DSIS_ROVRN)) {
		u_char pend,lastfree;

		outb(nec+ds_cmd, DSCM_START|DSCM_NODMA|DSCM_PG1);
		pend = inb(nec+ds1_curr);
		outb(nec+ds_cmd, DSCM_START|DSCM_NODMA|DSCM_PG0);
		lastfree = inb(nec+ds0_bnry);

		/* Have we wrapped? */
		if (lastfree >= RBUFEND/DS_PGSIZE)
			lastfree = RBUF/DS_PGSIZE;
		if (pend < lastfree && ns->ns_cur < pend)
			lastfree = ns->ns_cur;
		else	if (ns->ns_cur > lastfree)
			lastfree = ns->ns_cur;

		/* Something in the buffer? */
		while (pend != lastfree) {
			u_char nxt;

			/* Extract header from microcephalic board */
			nefetch(&ns->ns_ph,lastfree*DS_PGSIZE,
				sizeof(ns->ns_ph));
			ns->ns_ba = lastfree*DS_PGSIZE+sizeof(ns->ns_ph);

			/* Incipient paranoia */
			if (ns->ns_ph.pr_status == DSRS_RPC ||
				/* for dequna's */
				ns->ns_ph.pr_status == 0x21)
				nerecv (ns);
#ifdef NEDEBUG
			else  {
				printf("cur %x pnd %x lfr %x ",
					ns->ns_cur, pend, lastfree);
				printf("nxt %x len %x ", ns->ns_ph.pr_nxtpg,
					(ns->ns_ph.pr_sz1<<8)+ ns->ns_ph.pr_sz0);
				printf("Bogus Sts %x\n", ns->ns_ph.pr_status);	
			}
#endif

			nxt = ns->ns_ph.pr_nxtpg ;

			/* Sanity check */
			if ( nxt >= RBUF/DS_PGSIZE && nxt <= RBUFEND/DS_PGSIZE
				&& nxt <= pend)
				ns->ns_cur = nxt;
			else	ns->ns_cur = nxt = pend;

			/* Set the boundaries */
			lastfree = nxt;
			outb(nec+ds0_bnry, pred(nxt));
			outb(nec+ds_cmd, DSCM_START|DSCM_NODMA|DSCM_PG1);
			pend = inb(nec+ds1_curr);
			outb(nec+ds_cmd, DSCM_START|DSCM_NODMA|DSCM_PG0);
		}
		outb(nec+ds_cmd, DSCM_START|DSCM_NODMA);
	}

	/* Transmit error */
	if (isr & DSIS_TXE) {
		ns->ns_flags &= ~DSF_LOCK;
		/* Need to read these registers to clear status */
		ns->ns_if.if_collisions += inb(nec+ds0_tbcr0);
		ns->ns_if.if_oerrors++;
	}

	/* Packet Transmitted */
	if (isr & DSIS_TX) {
		ns->ns_flags &= ~DSF_LOCK;
		++ns->ns_if.if_opackets;
		ns->ns_if.if_collisions += inb(nec+ds0_tbcr0);
	}

	/* Receiver ovverun? */
	if (isr & DSIS_ROVRN) {
		log(LOG_ERR, "ne%d: error: isr %x\n", ns-ne_softc, isr
			/*, DSIS_BITS*/);
		outb(nec+ds0_rbcr0, 0);
		outb(nec+ds0_rbcr1, 0);
		outb(nec+ds0_tcr, DSTC_LB0);
		outb(nec+ds0_rcr, DSRC_MON);
		outb(nec+ds_cmd, DSCM_START|DSCM_NODMA);
		outb(nec+ds0_rcr, DSRC_AB);
		outb(nec+ds0_tcr, 0);
	}

	/* Any more to send? */
	outb (nec+ds_cmd, DSCM_NODMA|DSCM_PG0|DSCM_START);
	nestart(&ns->ns_if);
	outb (nec+ds_cmd, cmd);
	outb (nec+ds0_imr, 0xff);

	/* Still more to do? */
	isr = inb (nec+ds0_isr);
	if(isr) goto loop;
}

/*
 * Ethernet interface receiver interface.
 * If input error just drop packet.
 * Otherwise examine packet to determine type.  If can't determine length
 * from type, then have to drop packet.  Othewise decapsulate
 * packet based on type and pass to type specific higher-level
 * input routine.
 */
nerecv(ns)
	register struct ne_softc *ns;
{
	int len,i;

	ns->ns_if.if_ipackets++;
	len = ns->ns_ph.pr_sz0 + (ns->ns_ph.pr_sz1<<8);
	if(len < ETHER_MIN_LEN || len > ETHER_MAX_LEN)
		return;

	/* this need not be so torturous - one/two bcopys at most into mbufs */
	nefetch(ns->ns_pb, ns->ns_ba, min(len,DS_PGSIZE-sizeof(ns->ns_ph)));
	if (len > DS_PGSIZE-sizeof(ns->ns_ph)) {
		int l = len - (DS_PGSIZE-sizeof(ns->ns_ph)), b ;
		u_char *p = ns->ns_pb + (DS_PGSIZE-sizeof(ns->ns_ph));

		if(++ns->ns_cur > 0x7f) ns->ns_cur = 0x46;
		b = ns->ns_cur*DS_PGSIZE;
		
		while (l >= DS_PGSIZE) {
			nefetch(p, b, DS_PGSIZE);
			p += DS_PGSIZE; l -= DS_PGSIZE;
			if(++ns->ns_cur > 0x7f) ns->ns_cur = 0x46;
			b = ns->ns_cur*DS_PGSIZE;
		}
		if (l > 0)
			nefetch(p, b, l);
	}
	/* don't forget checksum! */
	len -= sizeof(struct ether_header) + sizeof(long);
			
	neread(ns,(caddr_t)(ns->ns_pb), len);
}

/*
 * Pass a packet to the higher levels.
 * We deal with the trailer protocol here.
 */
neread(ns, buf, len)
	register struct ne_softc *ns;
	char *buf;
	int len;
{
	register struct ether_header *eh;
    	struct mbuf *m;
	int off, resid;
	register struct ifqueue *inq;

	/*
	 * Deal with trailer protocol: if type is trailer type
	 * get true type from first 16-bit word past data.
	 * Remember that type was trailer by setting off.
	 */
	eh = (struct ether_header *)buf;
	eh->ether_type = ntohs((u_short)eh->ether_type);
#define	nedataaddr(eh, off, type)	((type)(((caddr_t)((eh)+1)+(off))))
	if (eh->ether_type >= ETHERTYPE_TRAIL &&
	    eh->ether_type < ETHERTYPE_TRAIL+ETHERTYPE_NTRAILER) {
		off = (eh->ether_type - ETHERTYPE_TRAIL) * 512;
		if (off >= ETHERMTU) return;		/* sanity */
		eh->ether_type = ntohs(*nedataaddr(eh, off, u_short *));
		resid = ntohs(*(nedataaddr(eh, off+2, u_short *)));
		if (off + resid > len) return;		/* sanity */
		len = off + resid;
	} else	off = 0;

	if (len == 0) return;

	/*
	 * Pull packet off interface.  Off is nonzero if packet
	 * has trailing header; neget will then force this header
	 * information to be at the front, but we still have to drop
	 * the type and length which are at the front of any trailer data.
	 */
	m = neget(buf, len, off, &ns->ns_if);
	if (m == 0) return;

	ether_input(&ns->ns_if, eh, m);
}

/*
 * Supporting routines
 */

/*
 * Pull read data off a interface.
 * Len is length of data, with local net header stripped.
 * Off is non-zero if a trailer protocol was used, and
 * gives the offset of the trailer information.
 * We copy the trailer information and then all the normal
 * data into mbufs.  When full cluster sized units are present
 * we copy into clusters.
 */
struct mbuf *
neget(buf, totlen, off0, ifp)
	caddr_t buf;
	int totlen, off0;
	struct ifnet *ifp;
{
	struct mbuf *top, **mp, *m, *p;
	int off = off0, len;
	register caddr_t cp = buf;
	char *epkt;

	buf += sizeof(struct ether_header);
	cp = buf;
	epkt = cp + totlen;


	if (off) {
		cp += off + 2 * sizeof(u_short);
		totlen -= 2 * sizeof(u_short);
	}

	MGETHDR(m, M_DONTWAIT, MT_DATA);
	if (m == 0)
		return (0);
	m->m_pkthdr.rcvif = ifp;
	m->m_pkthdr.len = totlen;
	m->m_len = MHLEN;

	top = 0;
	mp = &top;
	while (totlen > 0) {
		if (top) {
			MGET(m, M_DONTWAIT, MT_DATA);
			if (m == 0) {
				m_freem(top);
				return (0);
			}
			m->m_len = MLEN;
		}
		len = min(totlen, epkt - cp);
		if (len >= MINCLSIZE) {
			MCLGET(m, M_DONTWAIT);
			if (m->m_flags & M_EXT)
				m->m_len = len = min(len, MCLBYTES);
			else
				len = m->m_len;
		} else {
			/*
			 * Place initial small packet/header at end of mbuf.
			 */
			if (len < m->m_len) {
				if (top == 0 && len + max_linkhdr <= m->m_len)
					m->m_data += max_linkhdr;
				m->m_len = len;
			} else
				len = m->m_len;
		}
		bcopy(cp, mtod(m, caddr_t), (unsigned)len);
		cp += len;
		*mp = m;
		mp = &m->m_next;
		totlen -= len;
		if (cp == epkt)
			cp = buf;
	}
	return (top);
}

/*
 * Process an ioctl request.
 */
neioctl(ifp, cmd, data)
	register struct ifnet *ifp;
	int cmd;
	caddr_t data;
{
	register struct ifaddr *ifa = (struct ifaddr *)data;
	struct ne_softc *ns = &ne_softc[ifp->if_unit];
	struct ifreq *ifr = (struct ifreq *)data;
	int s = splimp(), error = 0;


	switch (cmd) {

	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;

		switch (ifa->ifa_addr->sa_family) {
#ifdef INET
		case AF_INET:
			neinit(ifp->if_unit);	/* before arpwhohas */
			((struct arpcom *)ifp)->ac_ipaddr =
				IA_SIN(ifa)->sin_addr;
			arpwhohas((struct arpcom *)ifp, &IA_SIN(ifa)->sin_addr);
			break;
#endif
#ifdef NS
		case AF_NS:
		    {
			register struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);

			if (ns_nullhost(*ina))
				ina->x_host = *(union ns_host *)(ns->ns_addr);
			else {
				/* 
				 * The manual says we can't change the address 
				 * while the receiver is armed,
				 * so reset everything
				 */
				ifp->if_flags &= ~IFF_RUNNING; 
				bcopy((caddr_t)ina->x_host.c_host,
				    (caddr_t)ns->ns_addr, sizeof(ns->ns_addr));
			}
			neinit(ifp->if_unit); /* does ne_setaddr() */
			break;
		    }
#endif
		default:
			neinit(ifp->if_unit);
			break;
		}
		break;

	case SIOCSIFFLAGS:
		if ((ifp->if_flags & IFF_UP) == 0 &&
		    ifp->if_flags & IFF_RUNNING) {
			ifp->if_flags &= ~IFF_RUNNING;
			outb(nec+ds_cmd,DSCM_STOP|DSCM_NODMA);
		} else if (ifp->if_flags & IFF_UP &&
		    (ifp->if_flags & IFF_RUNNING) == 0)
			neinit(ifp->if_unit);
		break;

#ifdef notdef
	case SIOCGHWADDR:
		bcopy((caddr_t)ns->ns_addr, (caddr_t) &ifr->ifr_data,
			sizeof(ns->ns_addr));
		break;
#endif

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