usr/src/sys/vax/if/if_acc.c

/*	if_acc.c	4.29	82/10/24	*/

#include "acc.h"
#ifdef NACC > 0

/*
 * ACC LH/DH ARPAnet IMP interface driver.
 */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/pte.h"
#include "../h/buf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/vmmac.h"

#include "../net/if.h"
#include "../netimp/if_imp.h"

#include "../vax/cpu.h"
#include "../vax/mtpr.h"
#include "../vaxif/if_accreg.h"
#include "../vaxif/if_uba.h"
#include "../vaxuba/ubareg.h"
#include "../vaxuba/ubavar.h"

int     accprobe(), accattach(), accrint(), accxint();
struct  uba_device *accinfo[NACC];
u_short accstd[] = { 0 };
struct  uba_driver accdriver =
	{ accprobe, 0, accattach, 0, accstd, "acc", accinfo };
#define	ACCUNIT(x)	minor(x)

int	accinit(), accstart(), accreset();

/*
 * "Lower half" of IMP interface driver.
 *
 * Each IMP interface is handled by a common module which handles
 * the IMP-host protocol and a hardware driver which manages the
 * hardware specific details of talking with the IMP.
 *
 * The hardware portion of the IMP driver handles DMA and related
 * management of UNIBUS resources.  The IMP protocol module interprets
 * contents of these messages and "controls" the actions of the
 * hardware module during IMP resets, but not, for instance, during
 * UNIBUS resets.
 *
 * The two modules are coupled at "attach time", and ever after,
 * through the imp interface structure.  Higher level protocols,
 * e.g. IP, interact with the IMP driver, rather than the ACC.
 */
struct	acc_softc {
	struct	ifnet *acc_if;		/* pointer to IMP's ifnet struct */
	struct	impcb *acc_ic;		/* data structure shared with IMP */
	struct	ifuba acc_ifuba;	/* UNIBUS resources */
	struct	mbuf *acc_iq;		/* input reassembly queue */
	short	acc_olen;		/* size of last message sent */
	char	acc_flush;		/* flush remainder of message */
} acc_softc[NACC];

/*
 * Reset the IMP and cause a transmitter interrupt by
 * performing a null DMA.
 */
accprobe(reg)
	caddr_t reg;
{
	register int br, cvec;		/* r11, r10 value-result */
	register struct accdevice *addr = (struct accdevice *)reg;

#ifdef lint
	br = 0; cvec = br; br = cvec;
	accrint(0); accxint(0);
#endif
	addr->icsr = ACC_RESET; DELAY(5000);
	addr->ocsr = ACC_RESET; DELAY(5000);
	addr->ocsr = OUT_BBACK; DELAY(5000);
	addr->owc = 0;
	addr->ocsr = ACC_IE | ACC_GO; DELAY(5000);
	addr->ocsr = 0;
	if (cvec && cvec != 0x200)	/* transmit -> receive */
		cvec -= 4;
#ifdef ECHACK
	br = 0x16;
#endif
	return (1);
}

/*
 * Call the IMP module to allow it to set up its internal
 * state, then tie the two modules together by setting up
 * the back pointers to common data structures.
 */
accattach(ui)
	struct uba_device *ui;
{
	register struct acc_softc *sc = &acc_softc[ui->ui_unit];
	register struct impcb *ip;
	struct ifimpcb {
		struct	ifnet ifimp_if;
		struct	impcb ifimp_impcb;
	} *ifimp;

	if ((ifimp = (struct ifimpcb *)impattacch(ui, acreset)) == 0)
		panic("accattach");
	sc->acc_if = &ifimp->ifimp_if;
	ip = &ifimp->ifimp_impcb;
	sc->acc_ic = ip;
	ip->ic_init = accinit;
	ip->ic_start = accstart;
	sc->acc_ifuba.ifu_flags = UBA_CANTWAIT;
#ifdef notdef
	sc->acc_ifuba.ifu_flags |= UBA_NEEDBDP;
#endif
}

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

	if (unit >= NACC || (ui = accinfo[unit]) == 0 || ui->ui_alive == 0 ||
	    ui->ui_ubanum != uban)
		return;
	printf(" acc%d", unit);
	sc = &acc_softc[unit];
	/* must go through IMP to allow it to set state */
	(*sc->acc_if->if_init)(unit);
}

/*
 * Initialize interface: clear recorded pending operations,
 * and retrieve, and initialize UNIBUS resources.  Note
 * return value is used by IMP init routine to mark IMP
 * unavailable for outgoing traffic.
 */
accinit(unit)
	int unit;
{
	register struct acc_softc *sc;
	register struct uba_device *ui;
	register struct accdevice *addr;
	int info;

	if (unit >= NACC || (ui = accinfo[unit]) == 0 || ui->ui_alive == 0) {
		printf("acc%d: not alive\n", unit);
		return (0);
	}
	sc = &acc_softc[unit];
	/*
	 * Header length is 0 since we have to passs
	 * the IMP leader up to the protocol interpretation
	 * routines.  If we had the header length as
	 * sizeof(struct imp_leader), then the if_ routines
	 * would asssume we handle it on input and output.
	 */
	if (if_ubainit(&sc->acc_ifuba, ui->ui_ubanum, 0,
	     (int)btoc(IMPMTU)) == 0) {
		printf("acc%d: can't initialize\n", unit);
		ui->ui_alive = 0;
		return (0);
	}
	addr = (struct accdevice *)ui->ui_addr;

	/*
	 * Reset the imp interface;
	 * the delays are pure guesswork.
	 */
        addr->ocsr = ACC_RESET; DELAY(5000);
	addr->ocsr = OUT_BBACK;	DELAY(5000);	/* reset host master ready */
	addr->ocsr = 0;
	if (accinputreset(addr, unit) == 0) {
		ui->ui_alive = 0;
		return (0);
	}

	/*
	 * Put up a read.  We can't restart any outstanding writes
	 * until we're back in synch with the IMP (i.e. we've flushed
	 * the NOOPs it throws at us).
	 * Note: IMPMTU includes the leader.
	 */
	info = sc->acc_ifuba.ifu_r.ifrw_info;
	addr->iba = (u_short)info;
	addr->iwc = -(IMPMTU >> 1);
#ifdef LOOPBACK
	addr->ocsr |= OUT_BBACK;
#endif
	addr->icsr =
		IN_MRDY | ACC_IE | IN_WEN | ((info & 0x30000) >> 12) | ACC_GO;
	return (1);
}

accinputreset(addr, unit)
	register struct accdevice *addr;
	register int unit;
{
	register int i;

	addr->icsr = ACC_RESET; DELAY(5000);
	addr->icsr = IN_MRDY | IN_WEN;		/* close the relay */
	DELAY(10000);
	/* YECH!!! */
	for (i = 0; i < 500; i++) {
		if ((addr->icsr & IN_HRDY) ||
		    (addr->icsr & (IN_RMR | IN_IMPBSY)) == 0)
			return (1);
		addr->icsr = IN_MRDY | IN_WEN; DELAY(10000);
		/* keep turning IN_RMR off */
	}
	printf("acc%d: imp doesn't respond, icsr=%b\n", unit,
		addr->icsr, ACC_INBITS);
	return (0);
}

/*
 * Start output on an interface.
 */
accstart(dev)
	dev_t dev;
{
	int unit = ACCUNIT(dev), info;
	register struct acc_softc *sc = &acc_softc[unit];
	register struct accdevice *addr;
	struct mbuf *m;
	u_short cmd;

	if (sc->acc_ic->ic_oactive)
		goto restart;

	/*
	 * Not already active, deqeue a request and
	 * map it onto the UNIBUS.  If no more
	 * requeusts, just return.
	 */
	IF_DEQUEUE(&sc->acc_if->if_snd, m);
	if (m == 0) {
		sc->acc_ic->ic_oactive = 0;
		return;
	}
	sc->acc_olen = if_wubaput(&sc->acc_ifuba, m);

restart:
	/*
	 * Have request mapped to UNIBUS for
	 * transmission; start the output.
	 */
	if (sc->acc_ifuba.ifu_flags & UBA_NEEDBDP)
		UBAPURGE(sc->acc_ifuba.ifu_uba, sc->acc_ifuba.ifu_w.ifrw_bdp);
	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	info = sc->acc_ifuba.ifu_w.ifrw_info;
	addr->oba = (u_short)info;
	addr->owc = -((sc->acc_olen + 1) >> 1);
	cmd = ACC_IE | OUT_ENLB | ((info & 0x30000) >> 12) | ACC_GO;
#ifdef LOOPBACK
	cmd |= OUT_BBACK;
#endif
	addr->ocsr = cmd;
	sc->acc_ic->ic_oactive = 1;
}

/*
 * Output interrupt handler.
 */
accxint(unit)
	int unit;
{
	register struct acc_softc *sc = &acc_softc[unit];
	register struct accdevice *addr;

	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	if (sc->acc_ic->ic_oactive == 0) {
		printf("acc%d: stray xmit interrupt, csr=%b\n", unit,
			addr->ocsr, ACC_OUTBITS);
		return;
	}
	sc->acc_if->if_opackets++;
	sc->acc_ic->ic_oactive = 0;
	if (addr->ocsr & ACC_ERR) {
		printf("acc%d: output error, ocsr=%b, icsr=%b\n", unit,
			addr->ocsr, ACC_OUTBITS, addr->icsr, ACC_INBITS);
		sc->acc_if->if_oerrors++;
	}
	if (sc->acc_ifuba.ifu_xtofree) {
		m_freem(sc->acc_ifuba.ifu_xtofree);
		sc->acc_ifuba.ifu_xtofree = 0;
	}
	if (sc->acc_if->if_snd.ifq_head)
		accstart(unit);
}

/*
 * Input interrupt handler
 */
accrint(unit)
	int unit;
{
	register struct acc_softc *sc = &acc_softc[unit];
	register struct accdevice *addr;
    	struct mbuf *m;
	int len, info;

	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	sc->acc_if->if_ipackets++;

	/*
	 * Purge BDP; flush message if error indicated.
	 */
	if (sc->acc_ifuba.ifu_flags & UBA_NEEDBDP)
		UBAPURGE(sc->acc_ifuba.ifu_uba, sc->acc_ifuba.ifu_r.ifrw_bdp);
	if (addr->icsr & ACC_ERR) {
		printf("acc%d: input error, csr=%b\n", unit,
		    addr->icsr, ACC_INBITS);
		sc->acc_if->if_ierrors++;
		sc->acc_flush = 1;
	}

	if (sc->acc_flush) {
		if (addr->icsr & IN_EOM)
			sc->acc_flush = 0;
		goto setup;
	}
	len = IMPMTU + (addr->iwc << 1);
	if (len < 0 || len > IMPMTU) {
		printf("acc%d: bad length=%d\n", len);
		sc->acc_if->if_ierrors++;
		goto setup;
	}

	/*
	 * The last parameter is always 0 since using
	 * trailers on the ARPAnet is insane.
	 */
	m = if_rubaget(&sc->acc_ifuba, len, 0);
	if (m == 0)
		goto setup;
	if ((addr->icsr & IN_EOM) == 0) {
		if (sc->acc_iq)
			m_cat(sc->acc_iq, m);
		else
			sc->acc_iq = m;
		goto setup;
	}
	if (sc->acc_iq) {
		m_cat(sc->acc_iq, m);
		m = sc->acc_iq;
		sc->acc_iq = 0;
	}
	impinput(unit, m);

setup:
	/*
	 * Setup for next message.
	 */
	info = sc->acc_ifuba.ifu_r.ifrw_info;
	addr->iba = (u_short)info;
	addr->iwc = -(IMPMTU >> 1);
	addr->icsr =
		IN_MRDY | ACC_IE | IN_WEN | ((info & 0x30000) >> 12) | ACC_GO;
}
#endif
Commit	Line	Data
	1	/* if_acc.c 4.29 82/10/24 */
	2
	3	#include "acc.h"
	4	#ifdef NACC > 0
	5
	6	/*
	7	* ACC LH/DH ARPAnet IMP interface driver.
	8	*/
	9
	10	#include "../h/param.h"
	11	#include "../h/systm.h"
	12	#include "../h/mbuf.h"
	13	#include "../h/pte.h"
	14	#include "../h/buf.h"
	15	#include "../h/protosw.h"
	16	#include "../h/socket.h"
	17	#include "../h/vmmac.h"
	18
	19	#include "../net/if.h"
	20	#include "../netimp/if_imp.h"
	21
	22	#include "../vax/cpu.h"
	23	#include "../vax/mtpr.h"
	24	#include "../vaxif/if_accreg.h"
	25	#include "../vaxif/if_uba.h"
	26	#include "../vaxuba/ubareg.h"
	27	#include "../vaxuba/ubavar.h"
	28
	29	int accprobe(), accattach(), accrint(), accxint();
	30	struct uba_device *accinfo[NACC];
	31	u_short accstd[] = { 0 };
	32	struct uba_driver accdriver =
	33	{ accprobe, 0, accattach, 0, accstd, "acc", accinfo };
	34	#define ACCUNIT(x) minor(x)
	35
	36	int accinit(), accstart(), accreset();
	37
	38	/*
	39	* "Lower half" of IMP interface driver.
	40	*
	41	* Each IMP interface is handled by a common module which handles
	42	* the IMP-host protocol and a hardware driver which manages the
	43	* hardware specific details of talking with the IMP.
	44	*
	45	* The hardware portion of the IMP driver handles DMA and related
	46	* management of UNIBUS resources. The IMP protocol module interprets
	47	* contents of these messages and "controls" the actions of the
	48	* hardware module during IMP resets, but not, for instance, during
	49	* UNIBUS resets.
	50	*
	51	* The two modules are coupled at "attach time", and ever after,
	52	* through the imp interface structure. Higher level protocols,
	53	* e.g. IP, interact with the IMP driver, rather than the ACC.
	54	*/
	55	struct acc_softc {
	56	struct ifnet acc_if; / pointer to IMP's ifnet struct */
	57	struct impcb acc_ic; / data structure shared with IMP */
	58	struct ifuba acc_ifuba; /* UNIBUS resources */
	59	struct mbuf acc_iq; / input reassembly queue */
	60	short acc_olen; /* size of last message sent */
	61	char acc_flush; /* flush remainder of message */
	62	} acc_softc[NACC];
	63
	64	/*
	65	* Reset the IMP and cause a transmitter interrupt by
	66	* performing a null DMA.
	67	*/
	68	accprobe(reg)
	69	caddr_t reg;
	70	{
	71	register int br, cvec; /* r11, r10 value-result */
	72	register struct accdevice addr = (struct accdevice )reg;
	73
	74	#ifdef lint
	75	br = 0; cvec = br; br = cvec;
	76	accrint(0); accxint(0);
	77	#endif
	78	addr->icsr = ACC_RESET; DELAY(5000);
	79	addr->ocsr = ACC_RESET; DELAY(5000);
	80	addr->ocsr = OUT_BBACK; DELAY(5000);
	81	addr->owc = 0;
	82	addr->ocsr = ACC_IE \| ACC_GO; DELAY(5000);
	83	addr->ocsr = 0;
	84	if (cvec && cvec != 0x200) /* transmit -> receive */
	85	cvec -= 4;
	86	#ifdef ECHACK
	87	br = 0x16;
	88	#endif
	89	return (1);
	90	}
	91
	92	/*
	93	* Call the IMP module to allow it to set up its internal
	94	* state, then tie the two modules together by setting up
	95	* the back pointers to common data structures.
	96	*/
	97	accattach(ui)
	98	struct uba_device *ui;
	99	{
	100	register struct acc_softc *sc = &acc_softc[ui->ui_unit];
	101	register struct impcb *ip;
	102	struct ifimpcb {
	103	struct ifnet ifimp_if;
	104	struct impcb ifimp_impcb;
	105	} *ifimp;
	106
	107	if ((ifimp = (struct ifimpcb *)impattacch(ui, acreset)) == 0)
	108	panic("accattach");
	109	sc->acc_if = &ifimp->ifimp_if;
	110	ip = &ifimp->ifimp_impcb;
	111	sc->acc_ic = ip;
	112	ip->ic_init = accinit;
	113	ip->ic_start = accstart;
	114	sc->acc_ifuba.ifu_flags = UBA_CANTWAIT;
	115	#ifdef notdef
	116	sc->acc_ifuba.ifu_flags \|= UBA_NEEDBDP;
	117	#endif
	118	}
	119
	120	/*
	121	* Reset interface after UNIBUS reset.
	122	* If interface is on specified uba, reset its state.
	123	*/
	124	accreset(unit, uban)
	125	int unit, uban;
	126	{
	127	register struct uba_device *ui;
	128	struct acc_softc *sc;
	129
	130	if (unit >= NACC \|\| (ui = accinfo[unit]) == 0 \|\| ui->ui_alive == 0 \|\|
	131	ui->ui_ubanum != uban)
	132	return;
	133	printf(" acc%d", unit);
	134	sc = &acc_softc[unit];
	135	/* must go through IMP to allow it to set state */
	136	(*sc->acc_if->if_init)(unit);
	137	}
	138
	139	/*
	140	* Initialize interface: clear recorded pending operations,
	141	* and retrieve, and initialize UNIBUS resources. Note
	142	* return value is used by IMP init routine to mark IMP
	143	* unavailable for outgoing traffic.
	144	*/
	145	accinit(unit)
	146	int unit;
	147	{
	148	register struct acc_softc *sc;
	149	register struct uba_device *ui;
	150	register struct accdevice *addr;
	151	int info;
	152
	153	if (unit >= NACC \|\| (ui = accinfo[unit]) == 0 \|\| ui->ui_alive == 0) {
	154	printf("acc%d: not alive\n", unit);
	155	return (0);
	156	}
	157	sc = &acc_softc[unit];
	158	/*
	159	* Header length is 0 since we have to passs
	160	* the IMP leader up to the protocol interpretation
	161	* routines. If we had the header length as
	162	* sizeof(struct imp_leader), then the if_ routines
	163	* would asssume we handle it on input and output.
	164	*/
	165	if (if_ubainit(&sc->acc_ifuba, ui->ui_ubanum, 0,
	166	(int)btoc(IMPMTU)) == 0) {
	167	printf("acc%d: can't initialize\n", unit);
	168	ui->ui_alive = 0;
	169	return (0);
	170	}
	171	addr = (struct accdevice *)ui->ui_addr;
	172
	173	/*
	174	* Reset the imp interface;
	175	* the delays are pure guesswork.
	176	*/
	177	addr->ocsr = ACC_RESET; DELAY(5000);
	178	addr->ocsr = OUT_BBACK; DELAY(5000); /* reset host master ready */
	179	addr->ocsr = 0;
	180	if (accinputreset(addr, unit) == 0) {
	181	ui->ui_alive = 0;
	182	return (0);
	183	}
	184
	185	/*
	186	* Put up a read. We can't restart any outstanding writes
	187	* until we're back in synch with the IMP (i.e. we've flushed
	188	* the NOOPs it throws at us).
	189	* Note: IMPMTU includes the leader.
	190	*/
	191	info = sc->acc_ifuba.ifu_r.ifrw_info;
	192	addr->iba = (u_short)info;
	193	addr->iwc = -(IMPMTU >> 1);
	194	#ifdef LOOPBACK
	195	addr->ocsr \|= OUT_BBACK;
	196	#endif
	197	addr->icsr =
	198	IN_MRDY \| ACC_IE \| IN_WEN \| ((info & 0x30000) >> 12) \| ACC_GO;
	199	return (1);
	200	}
	201
	202	accinputreset(addr, unit)
	203	register struct accdevice *addr;
	204	register int unit;
	205	{
	206	register int i;
	207
	208	addr->icsr = ACC_RESET; DELAY(5000);
	209	addr->icsr = IN_MRDY \| IN_WEN; /* close the relay */
	210	DELAY(10000);
	211	/* YECH!!! */
	212	for (i = 0; i < 500; i++) {
	213	if ((addr->icsr & IN_HRDY) \|\|
	214	(addr->icsr & (IN_RMR \| IN_IMPBSY)) == 0)
	215	return (1);
	216	addr->icsr = IN_MRDY \| IN_WEN; DELAY(10000);
	217	/* keep turning IN_RMR off */
	218	}
	219	printf("acc%d: imp doesn't respond, icsr=%b\n", unit,
	220	addr->icsr, ACC_INBITS);
	221	return (0);
	222	}
	223
	224	/*
	225	* Start output on an interface.
	226	*/
	227	accstart(dev)
	228	dev_t dev;
	229	{
	230	int unit = ACCUNIT(dev), info;
	231	register struct acc_softc *sc = &acc_softc[unit];
	232	register struct accdevice *addr;
	233	struct mbuf *m;
	234	u_short cmd;
	235
	236	if (sc->acc_ic->ic_oactive)
	237	goto restart;
	238
	239	/*
	240	* Not already active, deqeue a request and
	241	* map it onto the UNIBUS. If no more
	242	* requeusts, just return.
	243	*/
	244	IF_DEQUEUE(&sc->acc_if->if_snd, m);
	245	if (m == 0) {
	246	sc->acc_ic->ic_oactive = 0;
	247	return;
	248	}
	249	sc->acc_olen = if_wubaput(&sc->acc_ifuba, m);
	250
	251	restart:
	252	/*
	253	* Have request mapped to UNIBUS for
	254	* transmission; start the output.
	255	*/
	256	if (sc->acc_ifuba.ifu_flags & UBA_NEEDBDP)
	257	UBAPURGE(sc->acc_ifuba.ifu_uba, sc->acc_ifuba.ifu_w.ifrw_bdp);
	258	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	259	info = sc->acc_ifuba.ifu_w.ifrw_info;
	260	addr->oba = (u_short)info;
	261	addr->owc = -((sc->acc_olen + 1) >> 1);
	262	cmd = ACC_IE \| OUT_ENLB \| ((info & 0x30000) >> 12) \| ACC_GO;
	263	#ifdef LOOPBACK
	264	cmd \|= OUT_BBACK;
	265	#endif
	266	addr->ocsr = cmd;
	267	sc->acc_ic->ic_oactive = 1;
	268	}
	269
	270	/*
	271	* Output interrupt handler.
	272	*/
	273	accxint(unit)
	274	int unit;
	275	{
	276	register struct acc_softc *sc = &acc_softc[unit];
	277	register struct accdevice *addr;
	278
	279	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	280	if (sc->acc_ic->ic_oactive == 0) {
	281	printf("acc%d: stray xmit interrupt, csr=%b\n", unit,
	282	addr->ocsr, ACC_OUTBITS);
	283	return;
	284	}
	285	sc->acc_if->if_opackets++;
	286	sc->acc_ic->ic_oactive = 0;
	287	if (addr->ocsr & ACC_ERR) {
	288	printf("acc%d: output error, ocsr=%b, icsr=%b\n", unit,
	289	addr->ocsr, ACC_OUTBITS, addr->icsr, ACC_INBITS);
	290	sc->acc_if->if_oerrors++;
	291	}
	292	if (sc->acc_ifuba.ifu_xtofree) {
	293	m_freem(sc->acc_ifuba.ifu_xtofree);
	294	sc->acc_ifuba.ifu_xtofree = 0;
	295	}
	296	if (sc->acc_if->if_snd.ifq_head)
	297	accstart(unit);
	298	}
	299
	300	/*
	301	* Input interrupt handler
	302	*/
	303	accrint(unit)
	304	int unit;
	305	{
	306	register struct acc_softc *sc = &acc_softc[unit];
	307	register struct accdevice *addr;
	308	struct mbuf *m;
	309	int len, info;
	310
	311	addr = (struct accdevice *)accinfo[unit]->ui_addr;
	312	sc->acc_if->if_ipackets++;
	313
	314	/*
	315	* Purge BDP; flush message if error indicated.
	316	*/
	317	if (sc->acc_ifuba.ifu_flags & UBA_NEEDBDP)
	318	UBAPURGE(sc->acc_ifuba.ifu_uba, sc->acc_ifuba.ifu_r.ifrw_bdp);
	319	if (addr->icsr & ACC_ERR) {
	320	printf("acc%d: input error, csr=%b\n", unit,
	321	addr->icsr, ACC_INBITS);
	322	sc->acc_if->if_ierrors++;
	323	sc->acc_flush = 1;
	324	}
	325
	326	if (sc->acc_flush) {
	327	if (addr->icsr & IN_EOM)
	328	sc->acc_flush = 0;
	329	goto setup;
	330	}
	331	len = IMPMTU + (addr->iwc << 1);
	332	if (len < 0 \|\| len > IMPMTU) {
	333	printf("acc%d: bad length=%d\n", len);
	334	sc->acc_if->if_ierrors++;
	335	goto setup;
	336	}
	337
	338	/*
	339	* The last parameter is always 0 since using
	340	* trailers on the ARPAnet is insane.
	341	*/
	342	m = if_rubaget(&sc->acc_ifuba, len, 0);
	343	if (m == 0)
	344	goto setup;
	345	if ((addr->icsr & IN_EOM) == 0) {
	346	if (sc->acc_iq)
	347	m_cat(sc->acc_iq, m);
	348	else
	349	sc->acc_iq = m;
	350	goto setup;
	351	}
	352	if (sc->acc_iq) {
	353	m_cat(sc->acc_iq, m);
	354	m = sc->acc_iq;
	355	sc->acc_iq = 0;
	356	}
	357	impinput(unit, m);
	358
	359	setup:
	360	/*
	361	* Setup for next message.
	362	*/
	363	info = sc->acc_ifuba.ifu_r.ifrw_info;
	364	addr->iba = (u_short)info;
	365	addr->iwc = -(IMPMTU >> 1);
	366	addr->icsr =
	367	IN_MRDY \| ACC_IE \| IN_WEN \| ((info & 0x30000) >> 12) \| ACC_GO;
	368	}
	369	#endif