if_ec.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)if_ec.c	4.1	ULTRIX	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *			Modification History				*
 *
 * 01-Jun-89 -- darrell
 *	Removed cpup -- as it is unused here.
 *
 * 12-Apr-88  -- lea	4.35bsd changes + decnet hooks			*
 *									*
 * 13-Jun-86   -- jaw 	fix to uba reset and drivers.
 *									*
 *	Darrell Dunnuck 04/16/86					*
 *		badaddr is now called via the macro BADADDR.		*
 *									*
 * 18-mar-86  -- jaw     br/cvec changed to NOT use registers.
 *
 *	Darrell Dunnuck	03/15/86					*
 *		cpusw is now only accesed globally once, and the 	*
 *		pointer cpup is used thereafter.			*
 *									*
 *	Chet Juszczak - 03/12/86					*
 *		Modify MCLGET macro call to match new definition	*
 *									*
 * 18-Mar-86 -- jaw  add routines to cpu switch for nexus/unibus addreses
 *		     also got rid of some globals like nexnum.
 *		     ka8800 cleanup.
 *									*
 *	Larry Cohen  -	09/16/85					*
 * 		Add 43bsd alpha tape changes for subnet routing		*
 *									*
 ************************************************************************/

#include "ec.h"

#if	NEC > 0 || defined(BINARY)

/*
 * 3Com Ethernet Controller interface
 *
 *  @(#) if_ec.c 7.2 (Berkeley) 10/23/87
 */


#include "../data/if_ec_data.c"

#if CLSIZE == 2
#define ECBUFSIZE       32              /* on-board memory, clusters */
#endif

int	ecprobe(), ecattach(), ecrint(), ecxint(), eccollide();
u_short ecstd[] = { 0 };
struct	uba_driver ecdriver =
	{ ecprobe, 0, ecattach, 0, ecstd, "ec", ecinfo, 0, 0, 0 };

int	ecinit(),ecioctl(),ecoutput(),ecreset();
struct	mbuf *ecget();
extern struct protosw *iftype_to_proto(), *iffamily_to_proto();


extern struct ifnet loif;

/*
 * Configure on-board memory for an interface.
 * Called from autoconfig and after a uba reset.
 * The address of the memory on the uba is supplied in the device flags.
 */
/*
 * Do output DMA to determine interface presence and
 * interrupt vector.  DMA is too short to disturb other hosts.
 */

ecprobe(reg,ui)
        caddr_t reg;
        struct uba_device *ui;
{
       register struct ecdevice *addr = (struct ecdevice *)reg;
       register caddr_t ecbuf = (caddr_t) &umem[ui->ui_ubanum][ui->ui_flags];

#ifdef lint
        ecrint(0); ecxint(0); eccollide(0);
#endif



        if (BADADDR((caddr_t)addr, 2))
                return (-1);
	if  ((uba_hd[numuba].uba_type&UBA780) && 
			uba_hd[numuba].uh_uba->uba_sr) {
                uba_hd[numuba].uh_uba->uba_sr = uba_hd[numuba].uh_uba->uba_sr;
                return (-1);
	}
        /*
         * Make sure memory is turned on
         */
        addr->ec_rcr = EC_AROM;
        /*
         * Tell the system that the board has memory here, so it won't
         * attempt to allocate the addresses later.
         */
        if (ubamem(numuba, ui->ui_flags, ECBUFSIZE*CLSIZE, 1) == 0) {
                printf("ec%d: cannot reserve uba addresses\n", ui->ui_unit);
                addr->ec_rcr = EC_MDISAB;       /* disable memory */
                return (-1);
        }
        /*
         * Check for existence of buffers on Unibus.
         */
        if (BADADDR((caddr_t)ecbuf, 2)) {
bad:
                printf("ec%d: buffer mem not found\n", ui->ui_unit);
                (void) ubamem(numuba, ui->ui_flags, ECBUFSIZE*2, 0);
                addr->ec_rcr = EC_MDISAB;       /* disable memory */
                return (-1);
        }
	if  ((uba_hd[numuba].uba_type&UBA780) && 
			uba_hd[numuba].uh_uba->uba_sr) {
                uba_hd[numuba].uh_uba->uba_sr = uba_hd[numuba].uh_uba->uba_sr;
                goto bad;
        }
        if (ui->ui_alive == 0)          /* Only printf from autoconfig */
                printf("ec%d: mem %x-%x\n", ui->ui_unit,
                        ui->ui_flags, ui->ui_flags + ECBUFSIZE*CLBYTES - 1);
        ui->ui_type = 1;                /* Memory on, allocated */
        /*
         * Make a one byte packet in what should be buffer #0.
         * Submit it for sending.  This should cause an xmit interrupt.
         * The xmit interrupt vector is 8 bytes after the receive vector,
         * so adjust for this before returning.
         */
        *(u_short *)ecbuf = (u_short) 03777;
        ecbuf[03777] = '\0';
        addr->ec_xcr = EC_XINTEN|EC_XWBN;
        DELAY(100000);
        addr->ec_xcr = EC_XCLR;
        if (cvec > 0 && cvec != 0x200) {
                if (cvec & 04) {        /* collision interrupt */
                        cvec -= 04;
                        br += 1;                /* rcv is collision + 1 */
                } else {                /* xmit interrupt */
                        cvec -= 010;
                        br += 2;                /* rcv is xmit + 2 */

                }
        }
        return (1);

}


/*
 * Interface exists: make available by filling in network interface
 * record.  System will initialize the interface when it is ready
 * to accept packets.
 */
ecattach(ui)
	struct uba_device *ui;
{
	struct ec_softc *es = &ec_softc[ui->ui_unit];
	register struct ifnet *ifp = &es->es_if;
	register struct ecdevice *addr = (struct ecdevice *)ui->ui_addr;
	int i, j;
	u_char *cp;

	ifp->if_unit = ui->ui_unit;
	ifp->if_name = "ec";
	ifp->if_mtu = ETHERMTU;

	/*
	 * Read the ethernet address off the board, one nibble at a time.
	 */
	addr->ec_xcr = EC_UECLR; /* zero address pointer */
	addr->ec_rcr = EC_AROM;
	cp = es->es_addr;
#define	NEXTBIT	addr->ec_rcr = EC_AROM|EC_ASTEP; addr->ec_rcr = EC_AROM
	for (i=0; i < sizeof (es->es_addr); i++) {
		*cp = 0;
		for (j=0; j<=4; j+=4) {
			*cp |= ((addr->ec_rcr >> 8) & 0xf) << j;
			NEXTBIT; NEXTBIT; NEXTBIT; NEXTBIT;
		}
		cp++;
	}
	printf("ec%d: hardware address %s\n", ui->ui_unit,
		ether_sprintf(es->es_addr));
	ifp->if_init = ecinit;
	ifp->if_ioctl = ecioctl;
	ifp->if_output = ecoutput;
	ifp->if_reset = ecreset;
	ifp->if_flags = IFF_BROADCAST;
	for (i=0; i<16; i++)
		es->es_buf[i] 
		    = (u_char *)&umem[ui->ui_ubanum][ui->ui_flags + 2048*i];
	if_attach(ifp);
}

/*
 * Reset of interface after UNIBUS reset.
 * If interface is on specified uba, reset its state.
 */
ecreset(unit, uban)
	int unit, uban;
{
	register struct uba_device *ui;

	if (unit >= nNEC || (ui = ecinfo[unit]) == 0 || ui->ui_alive == 0 ||
	    ui->ui_ubanum != uban)
		return;
	printf(" ec%d", unit);
	ec_softc[unit].es_if.if_flags &= ~IFF_RUNNING;
	ecinit(unit);
}

/*
 * Initialization of interface; clear recorded pending
 * operations, and reinitialize UNIBUS usage.
 */
ecinit(unit)
	int unit;
{
	struct ec_softc *es = &ec_softc[unit];
	struct ecdevice *addr;
	register struct ifnet *ifp = &es->es_if;
	int i, s;

	/* not yet, if address still unknown */
	if (ifp->if_addrlist == (struct ifaddr *)0)
		return;

	/*
	 * Hang receive buffers and start any pending writes.
	 * Writing into the rcr also makes sure the memory
	 * is turned on.
	 */
	if ((ifp->if_flags & IFF_RUNNING) == 0) {
/*	if ((es->es_if.flags & IFF_RUNNING) == 0) { */
		addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
		s = splimp();
		/*
		 * write our ethernet address into the address recognition ROM 
		 * so we can always use the same EC_READ bits (referencing ROM),
		 * in case we change the address sometime.
		 * Note that this is safe here as the receiver is NOT armed.
		 */

		ec_setaddr(es->es_addr, unit);
		/*
		 * Arm the receiver
		 */
		for (i = ECRHBF; i >= ECRLBF; i--)
			addr->ec_rcr = EC_READ | i;
		es->es_oactive = 0;
		es->es_mask = ~0;
		es->es_if.if_flags |= IFF_RUNNING;
		if (es->es_if.if_snd.ifq_head)
			ecstart(unit);
		splx(s);
	}
}

/*
 * Start output on interface.  Get another datagram to send
 * off of the interface queue, and copy it to the interface
 * before starting the output.
 */
ecstart(unit)
{
	register struct ec_softc *es = &ec_softc[unit];
	struct ecdevice *addr;
	struct mbuf *m;

	if ((es->es_if.if_flags & IFF_RUNNING) == 0)
		return;
	IF_DEQUEUE(&es->es_if.if_snd, m);
	if (m == 0) {
		es->es_oactive = 0;
		return;
	}
	ecput(es->es_buf[ECTBF], m);
	addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
	addr->ec_xcr = EC_WRITE|ECTBF;
	es->es_oactive = 1;
}

/*
 * Ethernet interface transmitter interrupt.
 * Start another output if more data to send.
 */
ecxint(unit)
	int unit;
{
	register struct ec_softc *es = &ec_softc[unit];
	register struct ecdevice *addr =
		(struct ecdevice *)ecinfo[unit]->ui_addr;

	if (es->es_oactive == 0)
		return;
	if ((addr->ec_xcr&EC_XDONE) == 0 || (addr->ec_xcr&EC_XBN) != ECTBF) {
		printf("ec%d: stray xmit interrupt, xcr=%b\n", unit,
			addr->ec_xcr, EC_XBITS);
		es->es_oactive = 0;
		addr->ec_xcr = EC_XCLR;
		return;
	}
	es->es_if.if_opackets++;
	es->es_oactive = 0;
	es->es_mask = ~0;
	addr->ec_xcr = EC_XCLR;
	if (es->es_if.if_snd.ifq_head)
		ecstart(unit);
}

/*
 * Collision on ethernet interface.  Do exponential
 * backoff, and retransmit.  If have backed off all
 * the way print warning diagnostic, and drop packet.
 */
eccollide(unit)
	int unit;
{
	register struct ec_softc *es = &ec_softc[unit];
	register struct ecdevice *addr =
	    (struct ecdevice *)ecinfo[unit]->ui_addr;
	register i;
	int delay;

	es->es_if.if_collisions++;
	if (es->es_oactive == 0)
		return;

	/*
	 * Es_mask is a 16 bit number with n low zero bits, with
	 * n the number of backoffs.  When es_mask is 0 we have
	 * backed off 16 times, and give up.
	 */
	if (es->es_mask == 0) {
		es->es_if.if_oerrors++;
		printf("ec%d: send error\n", unit);
		/*
		 * Reset interface, then requeue rcv buffers.
		 * Some incoming packets may be lost, but that
		 * can't be helped.
		 */
		addr->ec_xcr = EC_UECLR;
		for (i=ECRHBF; i>=ECRLBF; i--)
			addr->ec_rcr = EC_READ|i;
		/*
		 * Reset and transmit next packet (if any).
		 */
		es->es_oactive = 0;
		es->es_mask = ~0;
		if (es->es_if.if_snd.ifq_head)
			ecstart(unit);
		return;
	}
	/*
	 * Do exponential backoff.  Compute delay based on low bits
	 * of the interval timer (1 bit for each transmission attempt,
	 * but at most 5 bits).  Then delay for that number of
	 * slot times.  A slot time is 51.2 microseconds (rounded to 51).
	 * This does not take into account the time already used to
	 * process the interrupt.
	 */
	es->es_mask <<= 1;
	delay = mfpr(ICR) & 0x1f &~ es->es_mask;
	DELAY(delay * 51);
	/*
	 * Clear the controller's collision flag, thus enabling retransmit.
	 */
	addr->ec_xcr = EC_CLEAR;
}

/*
 * Ethernet interface receiver interrupt.
 * 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.
 */
ecrint(unit)
	int unit;
{
	struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr;

	while (addr->ec_rcr & EC_RDONE)
		ecread(unit);
}

ecread(unit)
	int unit;
{
	register struct ec_softc *es = &ec_softc[unit];
	struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr;
	register struct ether_header *ec;
    	struct mbuf *m;
	int len, off, resid, ecoff, rbuf;
	struct ifqueue *inq;
	struct protosw *pr;
	u_char *ecbuf;

	es->es_if.if_ipackets++;
	rbuf = addr->ec_rcr & EC_RBN;
	if (rbuf < ECRLBF || rbuf > ECRHBF)
		panic("ecrint");
	ecbuf = es->es_buf[rbuf];
	ecoff = *(short *)ecbuf;
	if (ecoff <= ECRDOFF || ecoff > 2046) {
		es->es_if.if_ierrors++;
#ifdef notdef
		if (es->es_if.if_ierrors % 100 == 0)
			printf("ec%d: += 100 input errors\n", unit);
#endif
		goto setup;
	}

	/*
	 * Get input data length.
	 * Get pointer to ethernet header (in input buffer).
	 * 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.
	 */
	len = ecoff - ECRDOFF - sizeof (struct ether_header);
	ec = (struct ether_header *)(ecbuf + ECRDOFF);
	ec->ether_type = ntohs((u_short)ec->ether_type);
#define	ecdataaddr(ec, off, type)	((type)(((caddr_t)((ec)+1)+(off))))
	if (ec->ether_type >= ETHERTYPE_TRAIL &&
	    ec->ether_type < ETHERTYPE_TRAIL+ETHERTYPE_NTRAILER) {
		off = (ec->ether_type - ETHERTYPE_TRAIL) * 512;
		if (off >= ETHERMTU)
			goto setup;		/* sanity */
		ec->ether_type = ntohs(*ecdataaddr(ec, off, u_short *));
		resid = ntohs(*(ecdataaddr(ec, off+2, u_short *)));
		if (off + resid > len)
			goto setup;		/* sanity */
		len = off + resid;
	} else
		off = 0;
	if (len == 0)
		goto setup;

	/*
	 * Pull packet off interface.  Off is nonzero if packet
	 * has trailing header; ecget 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 = ecget(ecbuf, len, off);
	if (m == 0)
		goto setup;