if_en.c

open bsd vax module -if function

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * 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 the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS OR CONTRIBUTORS 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.
 *
 *	@(#)if_en.c	7.7 (Berkeley) 12/16/90
 */

#include "en.h"
#if NEN > 0

/*
 * Xerox prototype (3 Mb) Ethernet interface driver.
 */
#include "../include/pte.h"

#include "sys/param.h"
#include "sys/systm.h"
#include "sys/mbuf.h"
#include "sys/buf.h"
#include "sys/protosw.h"
#include "sys/socket.h"
#include "sys/vmmac.h"
#include "sys/errno.h"
#include "sys/ioctl.h"

#include "net/if.h"
#include "net/netisr.h"
#include "net/route.h"

#ifdef	INET
#include "netinet/in.h"
#include "netinet/in_systm.h"
#include "netinet/in_var.h"
#include "netinet/ip.h"
#endif

#ifdef PUP
#include "netpup/pup.h"
#include "netpup/ether.h"
#endif

#ifdef NS
#include "netns/ns.h"
#include "netns/ns_if.h"
#endif

#include "../include/cpu.h"
#include "../include/mtpr.h"
#include "if_en.h"
#include "if_enreg.h"
#include "if_uba.h"
#include "../uba/ubareg.h"
#include "../uba/ubavar.h"

#define	ENMTU	(1024+512)
#define	ENMRU	(1024+512+16)		/* 16 is enough to receive trailer */

int	enprobe(), enattach(), enrint(), enxint(), encollide();
struct	uba_device *eninfo[NEN];
u_short enstd[] = { 0 };
struct	uba_driver endriver =
	{ enprobe, 0, enattach, 0, enstd, "en", eninfo };
#define	ENUNIT(x)	minor(x)

int	eninit(),oldenoutput(),enreset(),enioctl(), enstart();

#ifdef notdef
/*
 * If you need to byte swap IP's in the system, define
 * this and do a SIOCSIFFLAGS at boot time.
 */
#define	ENF_SWABIPS	0x1000
#endif

/*
 * Ethernet software status per interface.
 *
 * Each interface is referenced by a network interface structure,
 * es_if, which the routing code uses to locate the interface.
 * This structure contains the output queue for the interface, its address, ...
 * We also have, for each interface, a UBA interface structure, which
 * contains information about the UNIBUS resources held by the interface:
 * map registers, buffered data paths, etc.  Information is cached in this
 * structure for use by the if_uba.c routines in running the interface
 * efficiently.
 */
struct	en_softc {
	struct	ifnet es_if;		/* network-visible interface */
	struct	ifuba es_ifuba;		/* UNIBUS resources */
	short	es_host;		/* hardware host number */
	short	es_delay;		/* current output delay */
	short	es_mask;		/* mask for current output delay */
	short	es_lastx;		/* host last transmitted to */
	short	es_oactive;		/* is output active? */
	short	es_olen;		/* length of last output */
	short	es_nsactive;		/* is interface enabled for ns? */
} en_softc[NEN];

/*
 * Do output DMA to determine interface presence and
 * interrupt vector.  DMA is too short to disturb other hosts.
 */
enprobe(reg)
	caddr_t reg;
{
	register int br, cvec;		/* r11, r10 value-result */
	register struct endevice *addr = (struct endevice *)reg;

#ifdef lint
	br = 0; cvec = br; br = cvec;
	enrint(0); enxint(0); encollide(0);
#endif
	addr->en_istat = 0;
	addr->en_owc = -1;
	addr->en_oba = 0;
	addr->en_ostat = EN_IEN|EN_GO;
	DELAY(100000);
	addr->en_ostat = 0;
	return (1);
}

/*
 * Interface exists: make available by filling in network interface
 * record.  System will initialize the interface when it is ready
 * to accept packets.
 */
enattach(ui)
	struct uba_device *ui;
{
	register struct en_softc *es = &en_softc[ui->ui_unit];

	es->es_if.if_unit = ui->ui_unit;
	es->es_if.if_name = "en";
	es->es_if.if_mtu = ENMTU;
	es->es_if.if_flags = IFF_BROADCAST;
	es->es_if.if_init = eninit;
	es->es_if.if_output = oldenoutput;
	es->es_if.if_start = enstart;
	es->es_if.if_ioctl = enioctl;
	es->es_if.if_reset = enreset;
	es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16 | UBA_CANTWAIT;
#if defined(VAX750)
	/* don't chew up 750 bdp's */
	if (cpu == VAX_750 && ui->ui_unit > 0)
		es->es_ifuba.ifu_flags &= ~UBA_NEEDBDP;
#endif
	if_attach(&es->es_if);
}

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

	if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 ||
	    ui->ui_ubanum != uban)
		return;
	printf(" en%d", unit);
	eninit(unit);
}

/*
 * Initialization of interface; clear recorded pending
 * operations, and reinitialize UNIBUS usage.
 */
eninit(unit)
	int unit;
{
	register struct en_softc *es = &en_softc[unit];
	register struct uba_device *ui = eninfo[unit];
	register struct endevice *addr;
	int s;

	if (es->es_if.if_addrlist == (struct ifaddr *)0)
		return;
	if (if_ubainit(&es->es_ifuba, ui->ui_ubanum,
	    sizeof (struct en_header), (int)btoc(ENMRU)) == 0) { 
		printf("en%d: can't initialize\n", unit);
		es->es_if.if_flags &= ~IFF_UP;
		return;
	}
	addr = (struct endevice *)ui->ui_addr;
	addr->en_istat = addr->en_ostat = 0;

	/*
	 * Hang a receive and start any
	 * pending writes by faking a transmit complete.
	 */
	s = splimp();
	addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
	addr->en_iwc = -(sizeof (struct en_header) + ENMRU) >> 1;
	addr->en_istat = EN_IEN|EN_GO;
	es->es_oactive = 1;
	es->es_if.if_flags |= IFF_RUNNING;
	enxint(unit);
	splx(s);
}

int	enalldelay = 0;
int	enlastdel = 50;
int	enlastmask = (~0) << 5;

/*
 * Start or restart output on interface.
 * If interface is already active, then this is a retransmit
 * after a collision, and just restuff registers and delay.
 * If interface is not already active, get another datagram
 * to send off of the interface queue, and map it to the interface
 * before starting the output.
 */
enstart(dev)
	dev_t dev;
{
        int unit = ENUNIT(dev);
	struct uba_device *ui = eninfo[unit];
	register struct en_softc *es = &en_softc[unit];
	register struct endevice *addr;
	register struct en_header *en;
	struct mbuf *m;
	int dest;

	if (es->es_oactive)
		goto restart;

	/*
	 * Not already active: dequeue another request
	 * and map it to the UNIBUS.  If no more requests,
	 * just return.
	 */
	IF_DEQUEUE(&es->es_if.if_snd, m);
	if (m == 0) {
		es->es_oactive = 0;
		return;
	}
	en = mtod(m, struct en_header *);
	dest = en->en_dhost;
	en->en_shost = es->es_host;
	es->es_olen = if_wubaput(&es->es_ifuba, m);
#ifdef ENF_SWABIPS
	/*
	 * The Xerox interface does word at a time DMA, so
	 * someone must do byte swapping of user data if high
	 * and low ender machines are to communicate.  It doesn't
	 * belong here, but certain people depend on it, so...
	 *
	 * Should swab everybody, but this is a kludge anyway.
	 */
	if (es->es_if.if_flags & ENF_SWABIPS) {
		en = (struct en_header *)es->es_ifuba.ifu_w.ifrw_addr;
		if (en->en_type == ENTYPE_IP)
			enswab((caddr_t)(en + 1), (caddr_t)(en + 1),
			    es->es_olen - sizeof (struct en_header) + 1);
	}
#endif

	/*
	 * Ethernet cannot take back-to-back packets (no
	 * buffering in interface.  To help avoid overrunning
	 * receivers, enforce a small delay (about 1ms) in interface:
	 *	* between all packets when enalldelay
	 *	* whenever last packet was broadcast
	 *	* whenever this packet is to same host as last packet
	 */
	if (enalldelay || es->es_lastx == 0 || es->es_lastx == dest) {
		es->es_delay = enlastdel;
		es->es_mask = enlastmask;
	}
	es->es_lastx = dest;

restart:
	/*
	 * Have request mapped to UNIBUS for transmission.
	 * Purge any stale data from this BDP, and start the otput.
	 */
	if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
		UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp);
	addr = (struct endevice *)ui->ui_addr;
	addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info;
	addr->en_odelay = es->es_delay;
	addr->en_owc = -((es->es_olen + 1) >> 1);
	addr->en_ostat = EN_IEN|EN_GO;
	es->es_oactive = 1;
}

/*
 * Ethernet interface transmitter interrupt.
 * Start another output if more data to send.
 */
enxint(unit)
	int unit;
{
	register struct uba_device *ui = eninfo[unit];
	register struct en_softc *es = &en_softc[unit];
	register struct endevice *addr = (struct endevice *)ui->ui_addr;

	if (es->es_oactive == 0)
		return;
	if (es->es_mask && (addr->en_ostat&EN_OERROR)) {
		es->es_if.if_oerrors++;
		endocoll(unit);
		return;
	}
	es->es_if.if_opackets++;
	es->es_oactive = 0;
	es->es_delay = 0;
	es->es_mask = ~0;
	if (es->es_ifuba.ifu_xtofree) {
		m_freem(es->es_ifuba.ifu_xtofree);
		es->es_ifuba.ifu_xtofree = 0;
	}
	if (es->es_if.if_snd.ifq_head == 0) {
		es->es_lastx = 256;		/* putatively illegal */
		return;
	}
	enstart(unit);
}

/*
 * Collision on ethernet interface.  Do exponential
 * backoff, and retransmit.  If have backed off all
 * the way print warning diagnostic, and drop packet.
 */
encollide(unit)
	int unit;
{
	struct en_softc *es = &en_softc[unit];

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

endocoll(unit)
	int unit;
{
	register struct en_softc *es = &en_softc[unit];

	/*
	 * 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