two siop drivers conflict. rename to ssh -- short for Symbios Scripts Hardware

1 files changed, 1537 insertions, 0 deletions

diff --git a/sys/arch/mvme68k/dev/ssh.c b/sys/arch/mvme68k/dev/ssh.c
new file mode 100644
index 00000000000..27330ad4df4
--- /dev/null
+++ b/sys/arch/mvme68k/dev/ssh.c
@@ -0,0 +1,1537 @@
+/*	$OpenBSD: ssh.c,v 1.1 2001/02/18 17:41:08 deraadt Exp $ */
+
+/*
+ * Copyright (c) 1994 Michael L. Hitch
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Van Jacobson of Lawrence Berkeley Laboratory.
+ *
+ * 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.
+ *
+ *	@(#)ssh.c	7.5 (Berkeley) 5/4/91
+ */
+
+/*
+ * 53C710 scsi adaptor driver
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/disklabel.h>
+#include <sys/dkstat.h>
+#include <sys/buf.h>
+#include <sys/malloc.h>
+#include <scsi/scsi_all.h>
+#include <scsi/scsiconf.h>
+#include <machine/autoconf.h>
+#include <mvme68k/dev/sshreg.h>
+#include <mvme68k/dev/sshvar.h>
+
+extern u_int   kvtop();
+
+/*
+ * SCSI delays
+ * In u-seconds, primarily for state changes on the SPC.
+ */
+#define	SCSI_CMD_WAIT	500000	/* wait per step of 'immediate' cmds */
+#define	SCSI_DATA_WAIT	500000	/* wait per data in/out step */
+#define	SCSI_INIT_WAIT	500000	/* wait per step (both) during init */
+
+void ssh_select __P((struct ssh_softc *));
+void sshabort __P((struct ssh_softc *, ssh_regmap_p, char *));
+void ssherror __P((struct ssh_softc *, ssh_regmap_p, u_char));
+void sshstart __P((struct ssh_softc *));
+void sshreset __P((struct ssh_softc *));
+void sshsetdelay __P((int));
+void ssh_scsidone __P((struct ssh_acb *, int));
+void ssh_sched __P((struct ssh_softc *));
+int  ssh_poll __P((struct ssh_softc *, struct ssh_acb *));
+int  sshintr __P((struct ssh_softc *));
+
+/* 53C710 script */
+const
+#include <mvme68k/dev/ssh_script.out>
+
+/* default to not inhibit sync negotiation on any drive */
+u_char ssh_inhibit_sync[8] = { 0, 0, 0, 0, 0, 0, 0};	/* initialize, so patchable */
+u_char ssh_allow_disc[8] = { 3, 3, 3, 3, 3, 3, 3, 3};
+int ssh_no_dma = 0;
+
+int ssh_reset_delay = 250;	/* delay after reset, in milleseconds */
+
+int ssh_cmd_wait = SCSI_CMD_WAIT;
+int ssh_data_wait = SCSI_DATA_WAIT;
+int ssh_init_wait = SCSI_INIT_WAIT;
+
+#ifdef DEBUG
+/*
+ *	0x01 - full debug
+ *	0x02 - DMA chaining
+ *	0x04 - sshintr
+ *	0x08 - phase mismatch
+ *	0x10 - <not used>
+ *	0x20 - panic on unhandled exceptions
+ *	0x100 - disconnect/reselect
+ */
+int   ssh_debug = 0;
+int   sshsync_debug = 0;
+int   sshdma_hits = 0;
+int   sshdma_misses = 0;
+int   sshchain_ints = 0;
+int   sshstarts = 0;
+int   sshints = 0;
+int   sshphmm = 0;
+#define SSH_TRACE_SIZE	128
+#define SSH_TRACE(a,b,c,d) \
+	ssh_trbuf[ssh_trix] = (a); \
+	ssh_trbuf[ssh_trix+1] = (b); \
+	ssh_trbuf[ssh_trix+2] = (c); \
+	ssh_trbuf[ssh_trix+3] = (d); \
+	ssh_trix = (ssh_trix + 4) & (SSH_TRACE_SIZE - 1);
+u_char   ssh_trbuf[SSH_TRACE_SIZE];
+int   ssh_trix;
+#else
+#define SSH_TRACE(a,b,c,d)
+#endif
+
+
+/*
+ * default minphys routine for ssh based controllers
+ */
+void
+ssh_minphys(bp)
+struct buf *bp;
+{
+
+	/*
+	 * No max transfer at this level.
+	 */
+	minphys(bp);
+}
+
+/*
+ * used by specific ssh controller
+ *
+ */
+int
+ssh_scsicmd(xs)
+struct scsi_xfer *xs;
+{
+	struct ssh_acb *acb;
+	struct ssh_softc *sc;
+	struct scsi_link *slp;
+	int flags, s, i;
+
+	slp = xs->sc_link;
+	sc = slp->adapter_softc;
+	flags = xs->flags;
+
+	/* XXXX ?? */
+	if (flags & SCSI_DATA_UIO)
+		panic("ssh: scsi data uio requested");
+
+	/* XXXX ?? */
+	if (sc->sc_nexus && flags & SCSI_POLL)
+		panic("ssh_scsicmd: busy");
+
+	s = splbio();
+	acb = sc->free_list.tqh_first;
+	if (acb) {
+		TAILQ_REMOVE(&sc->free_list, acb, chain);
+	}
+	splx(s);
+
+	if (acb == NULL) {
+		xs->error = XS_DRIVER_STUFFUP;
+		return (TRY_AGAIN_LATER);
+	}
+
+	acb->flags = ACB_ACTIVE;
+	acb->xs = xs;
+	bcopy(xs->cmd, &acb->cmd, xs->cmdlen);
+	acb->clen = xs->cmdlen;
+	acb->daddr = xs->data;
+	acb->dleft = xs->datalen;
+
+	s = splbio();
+	TAILQ_INSERT_TAIL(&sc->ready_list, acb, chain);
+
+	if (sc->sc_nexus == NULL)
+		ssh_sched(sc);
+
+	splx(s);
+
+	if (flags & SCSI_POLL || ssh_no_dma)
+		return (ssh_poll(sc, acb));
+	return (SUCCESSFULLY_QUEUED);
+}
+
+int
+ssh_poll(sc, acb)
+struct ssh_softc *sc;
+struct ssh_acb *acb;
+{
+	ssh_regmap_p rp = sc->sc_sshp;
+	struct scsi_xfer *xs = acb->xs;
+	int i;
+	int status;
+	u_char istat;
+	u_char dstat;
+	u_char sstat0;
+	int s;
+	int to;
+
+	s = splbio();
+	to = xs->timeout / 1000;
+	if (sc->nexus_list.tqh_first)
+		printf("%s: ssh_poll called with disconnected device\n",
+				 sc->sc_dev.dv_xname);
+	for (;;) {
+		/* use cmd_wait values? */
+		i = 50000;
+		spl0();
+		while (((istat = rp->ssh_istat) &
+				  (SSH_ISTAT_SIP | SSH_ISTAT_DIP)) == 0) {
+			if (--i <= 0) {
+#ifdef DEBUG
+				printf ("waiting: tgt %d cmd %02x sbcl %02x dsp %x (+%x) dcmd %x ds %x timeout %d\n",
+						  xs->sc_link->target, acb->cmd.opcode,
+						  rp->ssh_sbcl, rp->ssh_dsp,
+						  rp->ssh_dsp - sc->sc_scriptspa,
+						  *((long *)&rp->ssh_dcmd), &acb->ds, acb->xs->timeout);
+#endif
+				i = 50000;
+				--to;
+				if (to <= 0) {
+					sshreset(sc);
+					return (COMPLETE);
+				}
+			}
+			delay(10);
+		}
+		sstat0 = rp->ssh_sstat0;
+		dstat = rp->ssh_dstat;
+		if (ssh_checkintr(sc, istat, dstat, sstat0, &status)) {
+			if (acb != sc->sc_nexus)
+				printf("%s: ssh_poll disconnected device completed\n",
+						 sc->sc_dev.dv_xname);
+			else if ((sc->sc_flags & SSH_INTDEFER) == 0) {
+				sc->sc_flags &= ~SSH_INTSOFF;
+				rp->ssh_sien = sc->sc_sien;
+				rp->ssh_dien = sc->sc_dien;
+			}
+			ssh_scsidone(sc->sc_nexus, status);
+		}
+		if (xs->flags & ITSDONE)
+			break;
+	}
+	splx(s);
+	return (COMPLETE);
+}
+
+/*
+ * start next command that's ready
+ */
+void
+ssh_sched(sc)
+struct ssh_softc *sc;
+{
+	struct scsi_link *slp;
+	struct ssh_acb *acb;
+	int stat, i;
+
+#ifdef DEBUG
+	if (sc->sc_nexus) {
+		printf("%s: ssh_sched- nexus %x/%d ready %x/%d\n",
+				 sc->sc_dev.dv_xname, sc->sc_nexus,
+				 sc->sc_nexus->xs->sc_link->target,
+				 sc->ready_list.tqh_first,
+				 sc->ready_list.tqh_first->xs->sc_link->target);
+		return;
+	}
+#endif
+	for (acb = sc->ready_list.tqh_first; acb; acb = acb->chain.tqe_next) {
+		slp = acb->xs->sc_link;
+		i = slp->target;
+		if (!(sc->sc_tinfo[i].lubusy & (1 << slp->lun))) {
+			struct ssh_tinfo *ti = &sc->sc_tinfo[i];
+
+			TAILQ_REMOVE(&sc->ready_list, acb, chain);
+			sc->sc_nexus = acb;
+			slp = acb->xs->sc_link;
+			ti = &sc->sc_tinfo[slp->target];
+			ti->lubusy |= (1 << slp->lun);
+			break;
+		}
+	}
+
+	if (acb == NULL) {
+#ifdef DEBUGXXX
+		printf("%s: ssh_sched didn't find ready command\n",
+				 sc->sc_dev.dv_xname);
+#endif
+		return;
+	}
+
+	if (acb->xs->flags & SCSI_RESET)
+		sshreset(sc);
+
+#if 0
+	acb->cmd.bytes[0] |= slp->lun << 5;	/* XXXX */
+#endif
+	++sc->sc_active;
+	ssh_select(sc);
+}
+
+void
+ssh_scsidone(acb, stat)
+struct ssh_acb *acb;
+int stat;
+{
+	struct scsi_xfer *xs = acb->xs;
+	struct scsi_link *slp = xs->sc_link;
+	struct ssh_softc *sc = slp->adapter_softc;
+	int s, dosched = 0;
+
+#ifdef DIAGNOSTIC
+	if (acb == NULL || xs == NULL)
+		panic("ssh_scsidone");
+#endif
+	/*
+	 * is this right?
+	 */
+	xs->status = stat;
+
+	if (xs->error == XS_NOERROR && !(acb->flags & ACB_CHKSENSE)) {
+		if (stat == SCSI_CHECK) {
+			struct scsi_sense *ss = (void *)&acb->cmd;
+			bzero(ss, sizeof(*ss));
+			ss->opcode = REQUEST_SENSE;
+			ss->byte2 = slp->lun << 5;
+			ss->length = sizeof(struct scsi_sense_data);
+			acb->clen = sizeof(*ss);
+			acb->daddr = (char *)&xs->sense;
+			acb->dleft = sizeof(struct scsi_sense_data);
+			acb->flags = ACB_ACTIVE | ACB_CHKSENSE;
+			TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
+			--sc->sc_active;
+			sc->sc_tinfo[slp->target].lubusy &=
+			~(1 << slp->lun);
+			sc->sc_tinfo[slp->target].senses++;
+			if (sc->sc_nexus == acb) {
+				sc->sc_nexus = NULL;
+				ssh_sched(sc);
+			}
+			SSH_TRACE('d','s',0,0)
+			return;
+		}
+	}
+	if (xs->error == XS_NOERROR && (acb->flags & ACB_CHKSENSE)) {
+		xs->error = XS_SENSE;
+	} else {
+		xs->resid = 0;		/* XXXX */
+	}
+
+#if whataboutthisone
+		case SCSI_BUSY:
+			xs->error = XS_BUSY;
+			break;
+#endif
+
+	xs->flags |= ITSDONE;
+
+	/*
+	 * Remove the ACB from whatever queue it's on.  We have to do a bit of
+	 * a hack to figure out which queue it's on.  Note that it is *not*
+	 * necessary to cdr down the ready queue, but we must cdr down the
+	 * nexus queue and see if it's there, so we can mark the unit as no
+	 * longer busy.  This code is sickening, but it works.
+	 */
+	if (acb == sc->sc_nexus) {
+		sc->sc_nexus = NULL;
+		sc->sc_tinfo[slp->target].lubusy &= ~(1<<slp->lun);
+		if (sc->ready_list.tqh_first)
+			dosched = 1;	/* start next command */
+		--sc->sc_active;
+		SSH_TRACE('d','a',stat,0)
+	} else if (sc->ready_list.tqh_last == &acb->chain.tqe_next) {
+		TAILQ_REMOVE(&sc->ready_list, acb, chain);
+		SSH_TRACE('d','r',stat,0)
+	} else {
+		register struct ssh_acb *acb2;
+		for (acb2 = sc->nexus_list.tqh_first; acb2;
+			 acb2 = acb2->chain.tqe_next)
+			if (acb2 == acb) {
+				TAILQ_REMOVE(&sc->nexus_list, acb, chain);
+				sc->sc_tinfo[slp->target].lubusy
+				&= ~(1<<slp->lun);
+				--sc->sc_active;
+				break;
+			}
+		if (acb2)
+			;
+		else if (acb->chain.tqe_next) {
+			TAILQ_REMOVE(&sc->ready_list, acb, chain);
+			--sc->sc_active;
+		} else {
+			printf("%s: can't find matching acb\n",
+					 sc->sc_dev.dv_xname);
+#ifdef DDB
+/*			Debugger(); */
+#endif
+		}
+		SSH_TRACE('d','n',stat,0);
+	}
+	/* Put it on the free list. */
+	acb->flags = ACB_FREE;
+	TAILQ_INSERT_HEAD(&sc->free_list, acb, chain);
+
+	sc->sc_tinfo[slp->target].cmds++;
+
+	scsi_done(xs);
+
+	if (dosched && sc->sc_nexus == NULL)
+		ssh_sched(sc);
+}
+
+void
+sshabort(sc, rp, where)
+register struct ssh_softc *sc;
+ssh_regmap_p rp;
+char *where;
+{
+	int i;
+
+	printf ("%s: abort %s: dstat %02x, sstat0 %02x sbcl %02x\n",
+			  sc->sc_dev.dv_xname,
+			  where, rp->ssh_dstat, rp->ssh_sstat0, rp->ssh_sbcl);
+
+	if (sc->sc_active > 0) {
+#ifdef TODO
+		SET_SBIC_cmd (rp, SBIC_CMD_ABORT);
+		WAIT_CIP (rp);
+
+		GET_SBIC_asr (rp, asr);
+		if (asr & (SBIC_ASR_BSY|SBIC_ASR_LCI)) {
+			/* ok, get more drastic.. */
+
+			SET_SBIC_cmd (rp, SBIC_CMD_RESET);
+			delay(25);
+			SBIC_WAIT(rp, SBIC_ASR_INT, 0);
+			GET_SBIC_csr (rp, csr);			/* clears interrupt also */
+
+			return;
+		}
+
+		do {
+			SBIC_WAIT (rp, SBIC_ASR_INT, 0);
+			GET_SBIC_csr (rp, csr);
+		}
+		while ((csr != SBIC_CSR_DISC) && (csr != SBIC_CSR_DISC_1)
+				 && (csr != SBIC_CSR_CMD_INVALID));
+#endif
+
+		/* lets just hope it worked.. */
+#ifdef fix_this
+		for (i = 0; i < 2; ++i) {
+			if (sc->sc_iob[i].sc_xs && &sc->sc_iob[i] !=
+				 sc->sc_cur) {
+				printf ("sshabort: cleanup!\n");
+				sc->sc_iob[i].sc_xs = NULL;
+			}
+		}
+#endif	/* fix_this */
+/*		sc->sc_active = 0; */
+	}
+}
+
+void
+sshinitialize(sc)
+struct ssh_softc *sc;
+{
+	/*
+	 * Need to check that scripts is on a long word boundary
+	 * Also should verify that dev doesn't span non-contiguous
+	 * physical pages.
+	 */
+	sc->sc_scriptspa = kvtop(scripts);
+
+	/*
+	 * malloc sc_acb to ensure that DS is on a long word boundary.
+	 */
+
+	MALLOC(sc->sc_acb, struct ssh_acb *, 
+			 sizeof(struct ssh_acb) * SSH_NACB, M_DEVBUF, M_NOWAIT);
+	if (sc->sc_acb == NULL)
+		panic("sshinitialize: ACB malloc failed!");
+
+	sc->sc_tcp[1] = 1000 / sc->sc_clock_freq;
+	sc->sc_tcp[2] = 1500 / sc->sc_clock_freq;
+	sc->sc_tcp[3] = 2000 / sc->sc_clock_freq;
+	sc->sc_minsync = sc->sc_tcp[1];		/* in 4ns units */
+	if (sc->sc_minsync < 25)
+		sc->sc_minsync = 25;
+#if not_used
+	if (sc->sc_clock_freq <= 25)
+		sc->sc_tcp[0] = sc->sc_tcp[1];
+	else if (sc->sc_clock_freq <= 37)
+		sc->sc_tcp[0] = sc->sc_tcp[2];
+	else if (sc->sc_clock_freq <= 50)
+		sc->sc_tcp[0] = sc->sc_tcp[3];
+	else
+		sc->sc_tcp[0] = 3000 / sc->sc_clock_freq;
+#endif
+
+	sshreset (sc);
+}
+
+void
+sshreset(sc)
+struct ssh_softc *sc;
+{
+	ssh_regmap_p rp;
+	u_int i, s;
+	u_char  dummy;
+	struct ssh_acb *acb;
+
+	rp = sc->sc_sshp;
+
+	if (sc->sc_flags & SSH_ALIVE)
+		sshabort(sc, rp, "reset");
+
+	s = splbio();
+
+	/*
+	 * Reset the chip
+	 * XXX - is this really needed?
+	 */
+	rp->ssh_istat |= SSH_ISTAT_ABRT;	/* abort current script */
+	rp->ssh_istat |= SSH_ISTAT_RST;		/* reset chip */
+	rp->ssh_istat &= ~SSH_ISTAT_RST;
+	/*
+	 * Reset SCSI bus (do we really want this?)
+	 */
+	rp->ssh_sien = 0;
+	rp->ssh_scntl1 |= SSH_SCNTL1_RST;
+	delay(1);
+	rp->ssh_scntl1 &= ~SSH_SCNTL1_RST;
+
+	/*
+	 * Set up various chip parameters
+	 */
+	rp->ssh_scntl0 = SSH_ARB_FULL | SSH_SCNTL0_EPC | SSH_SCNTL0_EPG;
+	rp->ssh_scntl1 = SSH_SCNTL1_ESR;
+	rp->ssh_dcntl = sc->sc_dcntl;
+	rp->ssh_dmode = 0x80;	/* burst length = 4 */
+	rp->ssh_sien = 0x00;	/* don't enable interrupts yet */
+	rp->ssh_dien = 0x00;	/* don't enable interrupts yet */
+	rp->ssh_scid = 1 << sc->sc_link.adapter_target;
+	rp->ssh_dwt = 0x00;
+	rp->ssh_ctest0 |= SSH_CTEST0_BTD | SSH_CTEST0_EAN;
+	rp->ssh_ctest7 = sc->sc_ctest7;
+
+	/* will need to re-negotiate sync xfers */
+	bzero(&sc->sc_sync, sizeof (sc->sc_sync));
+
+	i = rp->ssh_istat;
+	if (i & SSH_ISTAT_SIP)
+		dummy = rp->ssh_sstat0;
+	if (i & SSH_ISTAT_DIP)
+		dummy = rp->ssh_dstat;
+
+	splx(s);
+
+	delay(ssh_reset_delay * 1000);
+	printf(": version %d target %d\n", rp->ssh_ctest8 >> 4,
+			 sc->sc_link.adapter_target);
+
+	if ((sc->sc_flags & SSH_ALIVE) == 0) {
+		TAILQ_INIT(&sc->ready_list);
+		TAILQ_INIT(&sc->nexus_list);
+		TAILQ_INIT(&sc->free_list);
+		sc->sc_nexus = NULL;
+		acb = sc->sc_acb;
+		bzero(acb, sizeof(struct ssh_acb) * SSH_NACB);
+		for (i = 0; i < SSH_NACB; i++) {
+			TAILQ_INSERT_TAIL(&sc->free_list, acb, chain);
+			acb++;
+		}
+		bzero(sc->sc_tinfo, sizeof(sc->sc_tinfo));
+	} else {
+		if (sc->sc_nexus != NULL) {
+			sc->sc_nexus->xs->error = XS_DRIVER_STUFFUP;
+			ssh_scsidone(sc->sc_nexus, sc->sc_nexus->stat[0]);
+		}
+		while (acb = sc->nexus_list.tqh_first) {
+			acb->xs->error = XS_DRIVER_STUFFUP;
+			ssh_scsidone(acb, acb->stat[0]);
+		}
+	}
+
+	sc->sc_flags |= SSH_ALIVE;
+	sc->sc_flags &= ~(SSH_INTDEFER|SSH_INTSOFF);
+	/* enable SCSI and DMA interrupts */
+	sc->sc_sien = SSH_SIEN_M_A | SSH_SIEN_STO | /*SSH_SIEN_SEL |*/ SSH_SIEN_SGE |
+					  SSH_SIEN_UDC | SSH_SIEN_RST | SSH_SIEN_PAR;
+	sc->sc_dien = SSH_DIEN_BF | SSH_DIEN_ABRT | SSH_DIEN_SIR |
+					  /*SSH_DIEN_WTD |*/ SSH_DIEN_IID;
+	rp->ssh_sien = sc->sc_sien;
+	rp->ssh_dien = sc->sc_dien;
+}
+
+/*
+ * Setup Data Storage for 53C710 and start SCRIPTS processing
+ */
+
+void
+ssh_start (sc, target, lun, cbuf, clen, buf, len)
+struct ssh_softc *sc;
+int target;
+int lun;
+u_char *cbuf;
+int clen;
+u_char *buf;
+int len;
+{
+	ssh_regmap_p rp = sc->sc_sshp;
+	int i;
+	int nchain;
+	int count, tcount;
+	char *addr, *dmaend;
+	struct ssh_acb *acb = sc->sc_nexus;
+
+#ifdef DEBUG
+	if (ssh_debug & 0x100 && rp->ssh_sbcl & SSH_BSY) {
+		printf ("ACK! ssh was busy: rp %x script %x dsa %x active %d\n",
+				  rp, &scripts, &acb->ds, sc->sc_active);
+		printf ("istat %02x sfbr %02x lcrc %02x sien %02x dien %02x\n",
+				  rp->ssh_istat, rp->ssh_sfbr, rp->ssh_lcrc,
+				  rp->ssh_sien, rp->ssh_dien);
+#ifdef DDB
+		/*Debugger();*/
+#endif
+	}
+#endif
+	acb->msgout[0] = MSG_IDENTIFY | lun;
+	if (ssh_allow_disc[target] & 2 ||
+		 (ssh_allow_disc[target] && len == 0))
+		acb->msgout[0] = MSG_IDENTIFY_DR | lun;
+	acb->status = 0;
+	acb->stat[0] = -1;
+	acb->msg[0] = -1;
+	acb->ds.scsi_addr = (0x10000 << target) | (sc->sc_sync[target].sxfer << 8);
+	acb->ds.idlen = 1;
+	acb->ds.idbuf = (char *) kvtop(&acb->msgout[0]);
+	acb->ds.cmdlen = clen;
+	acb->ds.cmdbuf = (char *) kvtop(cbuf);
+	acb->ds.stslen = 1;
+	acb->ds.stsbuf = (char *) kvtop(&acb->stat[0]);
+	acb->ds.msglen = 1;
+	acb->ds.msgbuf = (char *) kvtop(&acb->msg[0]);
+	acb->msg[1] = -1;
+	acb->ds.msginlen = 1;
+	acb->ds.extmsglen = 1;
+	acb->ds.synmsglen = 3;
+	acb->ds.msginbuf = (char *) kvtop(&acb->msg[1]);
+	acb->ds.extmsgbuf = (char *) kvtop(&acb->msg[2]);
+	acb->ds.synmsgbuf = (char *) kvtop(&acb->msg[3]);
+	bzero(&acb->ds.chain, sizeof (acb->ds.chain));
+
+	if (sc->sc_sync[target].state == SYNC_START) {
+		if (ssh_inhibit_sync[target]) {
+			sc->sc_sync[target].state = SYNC_DONE;
+			sc->sc_sync[target].sbcl = 0;
+			sc->sc_sync[target].sxfer = 0;
+#ifdef DEBUG
+			if (sshsync_debug)
+				printf ("Forcing target %d asynchronous\n", target);
+#endif
+		} else {
+			acb->msg[2] = -1;
+			acb->msgout[1] = MSG_EXT_MESSAGE;
+			acb->msgout[2] = 3;
+			acb->msgout[3] = MSG_SYNC_REQ;
+#ifdef MAXTOR_SYNC_KLUDGE
+			acb->msgout[4] = 50 / 4;	/* ask for ridiculous period */
+#else
+			acb->msgout[4] = sc->sc_minsync;
+#endif
+			acb->msgout[5] = SSH_MAX_OFFSET;
+			acb->ds.idlen = 6;
+			sc->sc_sync[target].state = SYNC_SENT;
+#ifdef DEBUG
+			if (sshsync_debug)
+				printf ("Sending sync request to target %d\n", target);
+#endif
+		}
+	}
+
+/*
+ * Build physical DMA addresses for scatter/gather I/O
+ */
+	acb->iob_buf = buf;
+	acb->iob_len = len;
+	acb->iob_curbuf = acb->iob_curlen = 0;
+	nchain = 0;
+	count = len;
+	addr = buf;
+	dmaend = NULL;
+	while (count > 0) {
+		acb->ds.chain[nchain].databuf = (char *) kvtop (addr);
+		if (count < (tcount = NBPG - ((int) addr & PGOFSET)))
+			tcount = count;
+		acb->ds.chain[nchain].datalen = tcount;
+		addr += tcount;
+		count -= tcount;
+		if (acb->ds.chain[nchain].databuf == dmaend) {
+			dmaend += acb->ds.chain[nchain].datalen;
+			acb->ds.chain[nchain].datalen = 0;
+			acb->ds.chain[--nchain].datalen += tcount;
+#ifdef DEBUG
+			++sshdma_hits;
+#endif
+		} else {
+			dmaend = acb->ds.chain[nchain].databuf +
+						acb->ds.chain[nchain].datalen;
+			acb->ds.chain[nchain].datalen = tcount;
+#ifdef DEBUG
+			if (nchain)	/* Don't count miss on first one */
+				++sshdma_misses;
+#endif
+		}
+		++nchain;
+	}
+#ifdef DEBUG
+	if (nchain != 1 && len != 0 && ssh_debug & 3) {
+		printf ("DMA chaining set: %d\n", nchain);
+		for (i = 0; i < nchain; ++i) {
+			printf ("  [%d] %8x %4x\n", i, acb->ds.chain[i].databuf,
+					  acb->ds.chain[i].datalen);
+		}
+	}
+#endif
+
+	/* push data cache for all data the 53c710 needs to access */
+	dma_cachectl (acb, sizeof (struct ssh_acb));
+	dma_cachectl (cbuf, clen);
+	if (buf != NULL && len != 0)
+		dma_cachectl (buf, len);
+
+#ifdef DEBUG
+	if (ssh_debug & 0x100 && rp->ssh_sbcl & SSH_BSY) {
+		printf ("ACK! ssh was busy at start: rp %x script %x dsa %x active %d\n",
+				  rp, &scripts, &acb->ds, sc->sc_active);
+#ifdef DDB
+		/*Debugger();*/
+#endif
+	}
+#endif
+
+	if (sc->nexus_list.tqh_first == NULL) {
+		if (rp->ssh_istat & SSH_ISTAT_CON)
+			printf("%s: ssh_select while connected?\n",
+					 sc->sc_dev.dv_xname);
+		rp->ssh_temp = 0;
+		rp->ssh_sbcl = sc->sc_sync[target].sbcl;
+		rp->ssh_dsa = kvtop(&acb->ds);
+		rp->ssh_dsp = sc->sc_scriptspa;
+		SSH_TRACE('s',1,0,0)
+	} else {
+		if ((rp->ssh_istat & SSH_ISTAT_CON) == 0) {
+			rp->ssh_istat = SSH_ISTAT_SIGP;
+			SSH_TRACE('s',2,0,0);
+		} else {
+			SSH_TRACE('s',3,rp->ssh_istat,0);
+		}
+	}
+#ifdef DEBUG
+	++sshstarts;
+#endif
+}
+
+/*
+ * Process a DMA or SCSI interrupt from the 53C710 SSH
+ */
+
+int
+ssh_checkintr(sc, istat, dstat, sstat0, status)
+struct   ssh_softc *sc;
+u_char   istat;
+u_char   dstat;
+u_char   sstat0;
+int   *status;
+{
+	ssh_regmap_p rp = sc->sc_sshp;
+	struct ssh_acb *acb = sc->sc_nexus;
+	int   target;
+	int   dfifo, dbc, sstat1;
+
+	dfifo = rp->ssh_dfifo;
+	dbc = rp->ssh_dbc0;
+	sstat1 = rp->ssh_sstat1;
+	rp->ssh_ctest8 |= SSH_CTEST8_CLF;
+	while ((rp->ssh_ctest1 & SSH_CTEST1_FMT) != SSH_CTEST1_FMT)
+		;
+	rp->ssh_ctest8 &= ~SSH_CTEST8_CLF;
+#ifdef DEBUG
+	++sshints;
+#if 0
+	if (ssh_debug & 0x100) {
+		DCIAS(&acb->stat[0]);	/* XXX */
+		printf ("sshchkintr: istat %x dstat %x sstat0 %x dsps %x sbcl %x sts %x msg %x\n",
+				  istat, dstat, sstat0, rp->ssh_dsps, rp->ssh_sbcl, acb->stat[0], acb->msg[0]);
+		printf ("sync msg in: %02x %02x %02x %02x %02x %02x\n",
+				  acb->msg[0], acb->msg[1], acb->msg[2],
+				  acb->msg[3], acb->msg[4], acb->msg[5]);
+	}
+#endif
+	if (rp->ssh_dsp && (rp->ssh_dsp < sc->sc_scriptspa ||
+								rp->ssh_dsp >= sc->sc_scriptspa + sizeof(scripts))) {
+		printf ("%s: dsp not within script dsp %x scripts %x:%x",
+				  sc->sc_dev.dv_xname, rp->ssh_dsp, sc->sc_scriptspa,
+				  sc->sc_scriptspa + sizeof(scripts));
+		printf(" istat %x dstat %x sstat0 %x\n",
+				 istat, dstat, sstat0);
+		Debugger();
+	}
+#endif
+	SSH_TRACE('i',dstat,istat,(istat&SSH_ISTAT_DIP)?rp->ssh_dsps&0xff:sstat0);
+	if (dstat & SSH_DSTAT_SIR && rp->ssh_dsps == 0xff00) {
+		/* Normal completion status, or check condition */
+#ifdef DEBUG
+		if (rp->ssh_dsa != kvtop(&acb->ds)) {
+			printf ("ssh: invalid dsa: %x %x\n", rp->ssh_dsa,
+					  kvtop(&acb->ds));
+			panic("*** ssh DSA invalid ***");
+		}
+#endif
+		target = acb->xs->sc_link->target;
+		if (sc->sc_sync[target].state == SYNC_SENT) {
+#ifdef DEBUG
+			if (sshsync_debug)
+				printf ("sync msg in: %02x %02x %02x %02x %02x %02x\n",
+						  acb->msg[0], acb->msg[1], acb->msg[2],
+						  acb->msg[3], acb->msg[4], acb->msg[5]);
+#endif
+			if (acb->msg[1] == 0xff)
+				printf ("%s: target %d ignored sync request\n",
+						  sc->sc_dev.dv_xname, target);
+			else if (acb->msg[1] == MSG_REJECT)
+				printf ("%s: target %d rejected sync request\n",
+						  sc->sc_dev.dv_xname, target);
+			sc->sc_sync[target].state = SYNC_DONE;
+			sc->sc_sync[target].sxfer = 0;
+			sc->sc_sync[target].sbcl = 0;
+			if (acb->msg[2] == 3 &&
+				 acb->msg[3] == MSG_SYNC_REQ &&
+				 acb->msg[5] != 0) {
+#ifdef MAXTOR_KLUDGE
+				/*
+				 * Kludge for my Maxtor XT8580S
+				 * It accepts whatever we request, even
+				 * though it won't work.  So we ask for
+				 * a short period than we can handle.  If
+				 * the device says it can do it, use 208ns.
+				 * If the device says it can do less than
+				 * 100ns, then we limit it to 100ns.
+				 */
+				if (acb->msg[4] && acb->msg[4] < 100 / 4) {
+#ifdef DEBUG
+					printf ("%d: target %d wanted %dns period\n",
+							  sc->sc_dev.dv_xname, target,
+							  acb->msg[4] * 4);
+#endif
+					if (acb->msg[4] == 50 / 4)
+						acb->msg[4] = 208 / 4;
+					else
+						acb->msg[4]	= 100 / 4;
+				}
+#endif /* MAXTOR_KLUDGE */
+				printf ("%s: target %d now synchronous, period=%dns, offset=%d\n",
+						  sc->sc_dev.dv_xname, target,
+						  acb->msg[4] * 4, acb->msg[5]);
+				scsi_period_to_ssh (sc, target);
+			}
+		}
+		dma_cachectl(&acb->stat[0], 1);
+		*status = acb->stat[0];
+#ifdef DEBUG
+		if (rp->ssh_sbcl & SSH_BSY) {
+			/*printf ("ACK! ssh was busy at end: rp %x script %x dsa %x\n",
+				 rp, &scripts, &acb->ds);*/
+#ifdef DDB
+			/*Debugger();*/
+#endif
+		}
+		if (acb->msg[0] != 0x00)
+			printf("%s: message was not COMMAND COMPLETE: %x\n",
+					 sc->sc_dev.dv_xname, acb->msg[0]);
+#endif
+		if (sc->nexus_list.tqh_first)
+			rp->ssh_dcntl |= SSH_DCNTL_STD;
+		return 1;
+	}
+	if (sstat0 & SSH_SSTAT0_M_A) {		/* Phase mismatch */
+#ifdef DEBUG
+		++sshphmm;
+		if (acb == NULL)
+			printf("%s: Phase mismatch with no active command?\n",
+					 sc->sc_dev.dv_xname);
+#endif
+		if (acb->iob_len) {
+			int adjust;
+			adjust = ((dfifo - (dbc & 0x7f)) & 0x7f);
+			if (sstat1 & SSH_SSTAT1_ORF)
+				++adjust;
+			if (sstat1 & SSH_SSTAT1_OLF)
+				++adjust;
+			acb->iob_curlen = *((long *)&rp->ssh_dcmd) & 0xffffff;
+			acb->iob_curlen += adjust;
+			acb->iob_curbuf = *((long *)&rp->ssh_dnad) - adjust;
+#ifdef DEBUG
+			if (ssh_debug & 0x100) {
+				int i;
+				printf ("Phase mismatch: curbuf %x curlen %x dfifo %x dbc %x sstat1 %x adjust %x sbcl %x starts %d acb %x\n",
+						  acb->iob_curbuf, acb->iob_curlen, dfifo,
+						  dbc, sstat1, adjust, rp->ssh_sbcl, sshstarts, acb);
+				if (acb->ds.chain[1].datalen) {
+					for (i = 0; acb->ds.chain[i].datalen; ++i)
+						printf("chain[%d] addr %x len %x\n",
+								 i, acb->ds.chain[i].databuf,
+								 acb->ds.chain[i].datalen);
+				}
+			}
+#endif
+			dma_cachectl (acb, sizeof(*acb));
+		}
+#ifdef DEBUG
+		SSH_TRACE('m',rp->ssh_sbcl,(rp->ssh_dsp>>8),rp->ssh_dsp);
+		if (ssh_debug & 9)
+			printf ("Phase mismatch: %x dsp +%x dcmd %x\n",
+					  rp->ssh_sbcl,
+					  rp->ssh_dsp - sc->sc_scriptspa,
+					  *((long *)&rp->ssh_dcmd));
+#endif
+		if ((rp->ssh_sbcl & SSH_REQ) == 0) {
+			printf ("Phase mismatch: REQ not asserted! %02x dsp %x\n",
+					  rp->ssh_sbcl, rp->ssh_dsp);
+#ifdef DEBUG
+			Debugger();
+#endif
+		}
+		switch (rp->ssh_sbcl & 7) {
+			case 0:		/* data out */
+			case 1:		/* data in */
+			case 2:		/* status */
+			case 3:		/* command */
+			case 6:		/* message in */
+			case 7:		/* message out */
+				rp->ssh_dsp = sc->sc_scriptspa + Ent_switch;
+				break;
+			default:
+				goto bad_phase;
+		}
+		return 0;
+	}
+	if (sstat0 & SSH_SSTAT0_STO) {		/* Select timed out */
+#ifdef DEBUG
+		if (acb == NULL)
+			printf("%s: Select timeout with no active command?\n",
+					 sc->sc_dev.dv_xname);
+		if (rp->ssh_sbcl & SSH_BSY) {
+			printf ("ACK! ssh was busy at timeout: rp %x script %x dsa %x\n",
+					  rp, &scripts, &acb->ds);
+			printf(" sbcl %x sdid %x istat %x dstat %x sstat0 %x\n",
+					 rp->ssh_sbcl, rp->ssh_sdid, istat, dstat, sstat0);
+			if (!(rp->ssh_sbcl & SSH_BSY)) {
+				printf ("Yikes, it's not busy now!\n");
+#if 0
+				*status = -1;
+				if (sc->nexus_list.tqh_first)
+					rp->ssh_dsp = sc->sc_scriptspa + Ent_wait_reselect;
+				return 1;
+#endif
+			}
+/*			rp->ssh_dcntl |= SSH_DCNTL_STD;*/
+			return (0);
+#ifdef DDB
+			Debugger();
+#endif
+		}
+#endif
+		*status = -1;
+		acb->xs->error = XS_SELTIMEOUT;
+		if (sc->nexus_list.tqh_first)
+			rp->ssh_dsp = sc->sc_scriptspa + Ent_wait_reselect;
+		return 1;
+	}
+	if (acb)
+		target = acb->xs->sc_link->target;
+	else
+		target = 7;
+	if (sstat0 & SSH_SSTAT0_UDC) {
+#ifdef DEBUG
+		if (acb == NULL)
+			printf("%s: Unexpected disconnect with no active command?\n",
+					 sc->sc_dev.dv_xname);
+		printf ("%s: target %d disconnected unexpectedly\n",
+				  sc->sc_dev.dv_xname, target);
+#endif
+#if 0
+		sshabort (sc, rp, "sshchkintr");
+#endif
+		*status = STS_BUSY;
+		if (sc->nexus_list.tqh_first)
+			rp->ssh_dsp = sc->sc_scriptspa + Ent_wait_reselect;
+		return 1;
+	}
+	if (dstat & SSH_DSTAT_SIR && (rp->ssh_dsps == 0xff01 ||
+											 rp->ssh_dsps == 0xff02)) {
+#ifdef DEBUG
+		if (ssh_debug & 0x100)
+			printf ("%s: ID %02x disconnected TEMP %x (+%x) curbuf %x curlen %x buf %x len %x dfifo %x dbc %x sstat1 %x starts %d acb %x\n",
+					  sc->sc_dev.dv_xname, 1 << target, rp->ssh_temp,
+					  rp->ssh_temp ? rp->ssh_temp - sc->sc_scriptspa : 0,
+					  acb->iob_curbuf, acb->iob_curlen,
+					  acb->ds.chain[0].databuf, acb->ds.chain[0].datalen, dfifo, dbc, sstat1, sshstarts, acb);
+#endif
+		if (acb == NULL) {
+			printf("%s: Disconnect with no active command?\n",
+					 sc->sc_dev.dv_xname);
+			return (0);
+		}
+		/*
+		 * XXXX need to update iob_curbuf/iob_curlen to reflect
+		 * current data transferred.  If device disconnected in
+		 * the middle of a DMA block, they should already be set
+		 * by the phase change interrupt.  If the disconnect
+		 * occurs on a DMA block boundary, we have to figure out
+		 * which DMA block it was.
+		 */
+		if (acb->iob_len && rp->ssh_temp) {
+			int n = rp->ssh_temp - sc->sc_scriptspa;
+
+			if (acb->iob_curlen && acb->iob_curlen != acb->ds.chain[0].datalen)
+				printf("%s: iob_curbuf/len already set? n %x iob %x/%x chain[0] %x/%x\n",
+						 sc->sc_dev.dv_xname, n, acb->iob_curbuf, acb->iob_curlen,
+						 acb->ds.chain[0].databuf, acb->ds.chain[0].datalen);
+			if (n < Ent_datain)
+				n = (n - Ent_dataout) / 16;
+			else
+				n = (n - Ent_datain) / 16;
+			if (n <= 0 && n > DMAMAXIO)
+				printf("TEMP invalid %d\n", n);
+			else {
+				acb->iob_curbuf = (u_long)acb->ds.chain[n].databuf;
+				acb->iob_curlen = acb->ds.chain[n].datalen;
+			}
+#ifdef DEBUG
+			if (ssh_debug & 0x100) {
+				printf("%s: TEMP offset %d", sc->sc_dev.dv_xname, n);
+				printf(" curbuf %x curlen %x\n", acb->iob_curbuf,
+						 acb->iob_curlen);
+			}
+#endif
+		}
+		/*
+		 * If data transfer was interrupted by disconnect, iob_curbuf
+		 * and iob_curlen should reflect the point of interruption.
+		 * Adjust the DMA chain so that the data transfer begins
+		 * at the appropriate place upon reselection.
+		 * XXX This should only be done on save data pointer message?
+		 */
+		if (acb->iob_curlen) {
+			int i, j;
+
+#ifdef DEBUG
+			if (ssh_debug & 0x100)
+				printf ("%s: adjusting DMA chain\n",
+						  sc->sc_dev.dv_xname);
+			if (rp->ssh_dsps == 0xff02)
+				printf ("%s: ID %02x disconnected without Save Data Pointers\n",
+						  sc->sc_dev.dv_xname, 1 << target);
+#endif
+			for (i = 0; i < DMAMAXIO; ++i) {
+				if (acb->ds.chain[i].datalen == 0)
+					break;
+				if (acb->iob_curbuf >= (long)acb->ds.chain[i].databuf &&
+					 acb->iob_curbuf < (long)(acb->ds.chain[i].databuf +
+													  acb->ds.chain[i].datalen))
+					break;
+			}
+			if (i >= DMAMAXIO || acb->ds.chain[i].datalen == 0)
+				printf("couldn't find saved data pointer\n");
+#ifdef DEBUG
+			if (ssh_debug & 0x100)
+				printf("  chain[0]: %x/%x -> %x/%x\n",
+						 acb->ds.chain[0].databuf,
+						 acb->ds.chain[0].datalen,
+						 acb->iob_curbuf,
+						 acb->iob_curlen);
+#endif
+			acb->ds.chain[0].databuf = (char *)acb->iob_curbuf;
+			acb->ds.chain[0].datalen = acb->iob_curlen;
+			for (j = 1, ++i; i < DMAMAXIO && acb->ds.chain[i].datalen; ++i, ++j) {
+#ifdef DEBUG
+				if (ssh_debug & 0x100)
+					printf("  chain[%d]: %x/%x -> %x/%x\n", j,
+							 acb->ds.chain[j].databuf,
+							 acb->ds.chain[j].datalen,
+							 acb->ds.chain[i].databuf,
+							 acb->ds.chain[i].datalen);
+#endif
+				acb->ds.chain[j].databuf = acb->ds.chain[i].databuf;
+				acb->ds.chain[j].datalen = acb->ds.chain[i].datalen;
+			}
+			if (j < DMAMAXIO)
+				acb->ds.chain[j].datalen = 0;
+			DCIAS(kvtop(&acb->ds.chain));
+		}
+		++sc->sc_tinfo[target].dconns;
+		/*
+		 * add nexus to waiting list
+		 * clear nexus
+		 * try to start another command for another target/lun
+		 */
+		acb->status = sc->sc_flags & SSH_INTSOFF;
+		TAILQ_INSERT_HEAD(&sc->nexus_list, acb, chain);
+		sc->sc_nexus = NULL;		/* no current device */
+		/* start script to wait for reselect */
+		if (sc->sc_nexus == NULL)
+			rp->ssh_dsp = sc->sc_scriptspa + Ent_wait_reselect;
+/* XXXX start another command ? */
+		if (sc->ready_list.tqh_first)
+			ssh_sched(sc);
+		return (0);
+	}
+	if (dstat & SSH_DSTAT_SIR && rp->ssh_dsps == 0xff03) {
+		int reselid = rp->ssh_scratch & 0x7f;
+		int reselun = rp->ssh_sfbr & 0x07;
+
+		sc->sc_sstat1 = rp->ssh_sbcl;	/* XXXX save current SBCL */
+#ifdef DEBUG
+		if (ssh_debug & 0x100)
+			printf ("%s: target ID %02x reselected dsps %x\n",
+					  sc->sc_dev.dv_xname, reselid,
+					  rp->ssh_dsps);
+		if ((rp->ssh_sfbr & 0x80) == 0)
+			printf("%s: Reselect message in was not identify: %x\n",
+					 sc->sc_dev.dv_xname, rp->ssh_sfbr);
+#endif
+		if (sc->sc_nexus) {
+#ifdef DEBUG
+			if (ssh_debug & 0x100)
+				printf ("%s: reselect ID %02x w/active\n",
+						  sc->sc_dev.dv_xname, reselid);
+#endif
+			TAILQ_INSERT_HEAD(&sc->ready_list, sc->sc_nexus, chain);
+			sc->sc_tinfo[sc->sc_nexus->xs->sc_link->target].lubusy
+			&= ~(1 << sc->sc_nexus->xs->sc_link->lun);
+			--sc->sc_active;
+		}
+		/*
+		 * locate acb of reselecting device
+		 * set sc->sc_nexus to acb
+		 */
+		for (acb = sc->nexus_list.tqh_first; acb;
+			 acb = acb->chain.tqe_next) {
+			if (reselid != (acb->ds.scsi_addr >> 16) ||
+				 reselun != (acb->msgout[0] & 0x07))
+				continue;
+			TAILQ_REMOVE(&sc->nexus_list, acb, chain);
+			sc->sc_nexus = acb;
+			sc->sc_flags |= acb->status;
+			acb->status = 0;
+			DCIAS(kvtop(&acb->stat[0]));
+			rp->ssh_dsa = kvtop(&acb->ds);
+			rp->ssh_sxfer = sc->sc_sync[acb->xs->sc_link->target].sxfer;
+			rp->ssh_sbcl = sc->sc_sync[acb->xs->sc_link->target].sbcl;
+			break;
+		}
+		if (acb == NULL) {
+			printf("%s: target ID %02x reselect nexus_list %x\n",
+					 sc->sc_dev.dv_xname, reselid,
+					 sc->nexus_list.tqh_first);
+			panic("unable to find reselecting device");
+		}
+		dma_cachectl (acb, sizeof(*acb));
+		rp->ssh_temp = 0;
+		rp->ssh_dcntl |= SSH_DCNTL_STD;
+		return (0);
+	}
+	if (dstat & SSH_DSTAT_SIR && rp->ssh_dsps == 0xff04) {
+		u_short ctest2 = rp->ssh_ctest2;
+
+		/* reselect was interrupted (by Sig_P or select) */
+#ifdef DEBUG
+		if (ssh_debug & 0x100 ||
+			 (ctest2 & SSH_CTEST2_SIGP) == 0)
+			printf ("%s: reselect interrupted (Sig_P?) scntl1 %x ctest2 %x 
+					  sfbr %x istat %x/%x\n", sc->sc_dev.dv_xname, rp->ssh_scntl1,
+					  ctest2, rp->ssh_sfbr, istat, rp->ssh_istat);
+#endif
+		/* XXX assumes it was not select */
+		if (sc->sc_nexus == NULL) {
+			printf("%s: reselect interrupted, sc_nexus == NULL\n",
+					 sc->sc_dev.dv_xname);
+#if 0
+			ssh_dump(sc);
+#ifdef DDB
+			Debugger();
+#endif
+#endif
+			rp->ssh_dcntl |= SSH_DCNTL_STD;
+			return (0);
+		}
+		target = sc->sc_nexus->xs->sc_link->target;
+		rp->ssh_temp = 0;
+		rp->ssh_dsa = kvtop(&sc->sc_nexus->ds);
+		rp->ssh_sxfer = sc->sc_sync[target].sxfer;
+		rp->ssh_sbcl = sc->sc_sync[target].sbcl;
+		rp->ssh_dsp = sc->sc_scriptspa;
+		return (0);
+	}
+	if (dstat & SSH_DSTAT_SIR && rp->ssh_dsps == 0xff06) {
+		if (acb == NULL)
+			printf("%s: Bad message-in with no active command?\n",
+					 sc->sc_dev.dv_xname);
+		/* Unrecognized message in byte */
+		dma_cachectl (&acb->msg[1],1);
+		printf ("%s: Unrecognized message in data sfbr %x msg %x sbcl %x\n",
+				  sc->sc_dev.dv_xname, rp->ssh_sfbr, acb->msg[1], rp->ssh_sbcl);
+		/* what should be done here? */
+		DCIAS(kvtop(&acb->msg[1]));
+		rp->ssh_dsp = sc->sc_scriptspa + Ent_switch;
+		return (0);
+	}
+	if (dstat & SSH_DSTAT_SIR && rp->ssh_dsps == 0xff0a) {
+		/* Status phase wasn't followed by message in phase? */
+		printf ("%s: Status phase not followed by message in phase? sbcl %x sbdl %x\n",
+				  sc->sc_dev.dv_xname, rp->ssh_sbcl, rp->ssh_sbdl);
+		if (rp->ssh_sbcl == 0xa7) {
+			/* It is now, just continue the script? */
+			rp->ssh_dcntl |= SSH_DCNTL_STD;
+			return (0);
+		}
+	}
+	if (sstat0 == 0 && dstat & SSH_DSTAT_SIR) {
+		dma_cachectl (&acb->stat[0], 1);
+		dma_cachectl (&acb->msg[0], 1);
+		printf ("SSH interrupt: %x sts %x msg %x %x sbcl %x\n",
+				  rp->ssh_dsps, acb->stat[0], acb->msg[0], acb->msg[1],
+				  rp->ssh_sbcl);
+		sshreset (sc);
+		*status = -1;
+		return 0;	/* sshreset has cleaned up */
+	}
+	if (sstat0 & SSH_SSTAT0_SGE)
+		printf ("SSH: SCSI Gross Error\n");
+	if (sstat0 & SSH_SSTAT0_PAR)
+		printf ("SSH: Parity Error\n");
+	if (dstat & SSH_DSTAT_IID)
+		printf ("SSH: Invalid instruction detected\n");
+	bad_phase:
+	/*
+	 * temporary panic for unhandled conditions
+	 * displays various things about the 53C710 status and registers
+	 * then panics.
+	 * XXXX need to clean this up to print out the info, reset, and continue
+	 */
+	printf ("sshchkintr: target %x ds %x\n", target, &acb->ds);
+	printf ("scripts %x ds %x rp %x dsp %x dcmd %x\n", sc->sc_scriptspa,
+			  kvtop(&acb->ds), kvtop(rp), rp->ssh_dsp,
+			  *((long *)&rp->ssh_dcmd));
+	printf ("sshchkintr: istat %x dstat %x sstat0 %x dsps %x "
+			  "dsa %x sbcl %x sts %x msg %x %x sfbr %x\n",
+			  istat, dstat, sstat0, rp->ssh_dsps, rp->ssh_dsa,
+			  rp->ssh_sbcl, acb->stat[0], acb->msg[0], acb->msg[1],
+			  rp->ssh_sfbr);
+#ifdef DEBUG
+	if (ssh_debug & 0x20)
+		panic("sshchkintr: **** temp ****");
+#ifdef DDB
+	/* Debugger(); */
+#endif
+#endif
+	sshreset (sc);		/* hard reset */
+	*status = -1;
+	return 0;		/* sshreset cleaned up */
+}
+
+void
+ssh_select(sc)
+struct ssh_softc *sc;
+{
+	ssh_regmap_p rp;
+	struct ssh_acb *acb = sc->sc_nexus;
+
+#ifdef DEBUG
+	if (ssh_debug & 1)
+		printf ("%s: select ", sc->sc_dev.dv_xname);
+#endif
+
+	rp = sc->sc_sshp;
+	if (acb->xs->flags & SCSI_POLL || ssh_no_dma) {
+		sc->sc_flags |= SSH_INTSOFF;
+		sc->sc_flags &= ~SSH_INTDEFER;
+		if ((rp->ssh_istat & 0x08) == 0) {
+			rp->ssh_sien = 0;
+			rp->ssh_dien = 0;
+		}
+#if 0
+	} else if ((sc->sc_flags & SSH_INTDEFER) == 0) {
+		sc->sc_flags &= ~SSH_INTSOFF;
+		if ((rp->ssh_istat & 0x08) == 0) {
+			rp->ssh_sien = sc->sc_sien;
+			rp->ssh_dien = sc->sc_dien;
+		}
+#endif
+	}
+#ifdef DEBUG
+	if (ssh_debug & 1)
+		printf ("ssh_select: target %x cmd %02x ds %x\n",
+				  acb->xs->sc_link->target, acb->cmd.opcode,
+				  &sc->sc_nexus->ds);
+#endif
+
+	ssh_start(sc, acb->xs->sc_link->target, acb->xs->sc_link->lun,
+				  &acb->cmd, acb->clen, acb->daddr, acb->dleft);
+
+	return;
+}
+
+/*
+ * 53C710 interrupt handler
+ */
+
+int
+sshintr (sc)
+register struct ssh_softc *sc;
+{
+	ssh_regmap_p rp;
+	register u_char istat, dstat, sstat0;
+	int status;
+	int s = splbio();
+
+	istat = sc->sc_istat;
+	if ((istat & (SSH_ISTAT_SIP | SSH_ISTAT_DIP)) == 0) {
+		splx(s);
+		return;
+	}
+
+	/* Got a valid interrupt on this device */
+	rp = sc->sc_sshp;
+	dstat = sc->sc_dstat;
+	sstat0 = sc->sc_sstat0;
+	if (dstat & SSH_DSTAT_SIR)
+		sc->sc_intcode = rp->ssh_dsps;
+	sc->sc_istat = 0;
+
+#ifdef DEBUG
+	if (ssh_debug & 1)
+		printf ("%s: intr istat %x dstat %x sstat0 %x\n",
+				  sc->sc_dev.dv_xname, istat, dstat, sstat0);
+	if (!sc->sc_active) {
+		printf ("%s: spurious interrupt? istat %x dstat %x sstat0 %x status %x\n",
+				  sc->sc_dev.dv_xname, istat, dstat, sstat0, sc->sc_nexus->stat[0]);
+	}
+#else 
+	if (!sc->sc_active) {
+		printf ("%s: spurious interrupt? istat %x dstat %x sstat0 %x status %x\n",
+				  sc->sc_dev.dv_xname, istat, dstat, sstat0, sc->sc_nexus->stat[0]);
+		return;
+	}
+#endif
+
+#ifdef DEBUG
+	if (ssh_debug & 5) {
+		DCIAS(kvtop(&sc->sc_nexus->stat[0]));
+		printf ("%s: intr istat %x dstat %x sstat0 %x dsps %x sbcl %x sts %x msg %x\n",
+				  sc->sc_dev.dv_xname, istat, dstat, sstat0,
+				  rp->ssh_dsps,  rp->ssh_sbcl,
+				  sc->sc_nexus->stat[0], sc->sc_nexus->msg[0]);
+	}
+#endif
+	if (sc->sc_flags & SSH_INTDEFER) {
+		sc->sc_flags &= ~(SSH_INTDEFER | SSH_INTSOFF);
+		rp->ssh_sien = sc->sc_sien;
+		rp->ssh_dien = sc->sc_dien;
+	}
+	if (ssh_checkintr (sc, istat, dstat, sstat0, &status)) {
+#if 1
+		if (status == 0xff)
+			printf ("sshintr: status == 0xff\n");
+#endif
+		if ((sc->sc_flags & (SSH_INTSOFF | SSH_INTDEFER)) != SSH_INTSOFF) {
+#if 0
+			if (rp->ssh_sbcl & SSH_BSY) {
+				printf ("%s: SCSI bus busy at completion",
+						  sc->sc_dev.dv_xname);
+				printf(" targ %d sbcl %02x sfbr %x lcrc %02x dsp +%x\n",
+						 sc->sc_nexus->xs->sc_link->target,
+						 rp->ssh_sbcl, rp->ssh_sfbr, rp->ssh_lcrc,
+						 rp->ssh_dsp - sc->sc_scriptspa);
+			}
+#endif
+			ssh_scsidone(sc->sc_nexus, sc->sc_nexus->stat[0]);
+		}
+	}
+	splx(s);
+}
+
+/*
+ * This is based on the Progressive Peripherals 33Mhz Zeus driver and will
+ * not be correct for other 53c710 boards.
+ *
+ */
+scsi_period_to_ssh (sc, target)
+struct ssh_softc *sc;
+{
+	int period, offset, i, sxfer, sbcl;
+
+	period = sc->sc_nexus->msg[4];
+	offset = sc->sc_nexus->msg[5];
+	for (sbcl = 1; sbcl < 4; ++sbcl) {
+		sxfer = (period * 4 - 1) / sc->sc_tcp[sbcl] - 3;
+		if (sxfer >= 0 && sxfer <= 7)
+			break;
+	}
+	if (sbcl > 3) {
+		printf("ssh_sync: unable to compute sync params for period %dns\n",
+				 period * 4);
+		/*
+		 * XXX need to pick a value we can do and renegotiate
+		 */
+		sxfer = sbcl = 0;
+	} else
+		sxfer	= (sxfer << 4) | ((offset <= SSH_MAX_OFFSET) ?
+										offset : SSH_MAX_OFFSET);
+	sc->sc_sync[target].sxfer = sxfer;
+	sc->sc_sync[target].sbcl = sbcl;
+#ifdef DEBUG
+	printf ("ssh sync: ssh_sxfr %02x, ssh_sbcl %02x\n", sxfer, sbcl);
+#endif
+}
+
+#ifdef DEBUG
+
+#if SSH_TRACE_SIZE
+void
+ssh_dump_trace()
+{
+	int i;
+
+	printf("ssh trace: next index %d\n", ssh_trix);
+	i = ssh_trix;
+	do {
+		printf("%3d: '%c' %02x %02x %02x\n", i, ssh_trbuf[i],
+				 ssh_trbuf[i + 1], ssh_trbuf[i + 2], ssh_trbuf[i + 3]);
+		i = (i + 4) & (SSH_TRACE_SIZE - 1);
+	} while (i != ssh_trix);
+}
+#endif
+
+void
+ssh_dump_acb(acb)
+struct ssh_acb *acb;
+{
+	u_char *b = (u_char *) &acb->cmd;
+	int i;
+
+#if SSH_TRACE_SIZE
+	ssh_dump_trace();
+#endif
+	printf("acb@%x ", acb);
+	if (acb->xs == NULL) {
+		printf("<unused>\n");
+		return;
+	}
+	printf("(%d:%d) flags %2x clen %2d cmd ", acb->xs->sc_link->target,
+			 acb->xs->sc_link->lun, acb->flags, acb->clen);
+	for (i = acb->clen; i; --i)
+		printf(" %02x", *b++);
+	printf("\n");
+	printf("  xs: %08x data %8x:%04x ", acb->xs, acb->xs->data,
+			 acb->xs->datalen);
+	printf("va %8x:%04x ", acb->iob_buf, acb->iob_len);
+	printf("cur %8x:%04x\n", acb->iob_curbuf, acb->iob_curlen);
+}
+
+void
+ssh_dump(sc)
+struct ssh_softc *sc;
+{
+	struct ssh_acb *acb;
+	ssh_regmap_p rp = sc->sc_sshp;
+	int s;
+	int i;
+
+	s = splbio();
+	printf("%s@%x regs %x istat %x\n",
+			 sc->sc_dev.dv_xname, sc, rp, rp->ssh_istat);
+	if (acb = sc->free_list.tqh_first) {
+		printf("Free list:\n");
+		while (acb) {
+			ssh_dump_acb(acb);
+			acb = acb->chain.tqe_next;
+		}
+	}
+	if (acb = sc->ready_list.tqh_first) {
+		printf("Ready list:\n");
+		while (acb) {
+			ssh_dump_acb(acb);
+			acb = acb->chain.tqe_next;
+		}
+	}
+	if (acb = sc->nexus_list.tqh_first) {
+		printf("Nexus list:\n");
+		while (acb) {
+			ssh_dump_acb(acb);
+			acb = acb->chain.tqe_next;
+		}
+	}
+	if (sc->sc_nexus) {
+		printf("Nexus:\n");
+		ssh_dump_acb(sc->sc_nexus);
+	}
+	for (i = 0; i < 8; ++i) {
+		if (sc->sc_tinfo[i].cmds > 2) {
+			printf("tgt %d: cmds %d disc %d senses %d lubusy %x\n",
+					 i, sc->sc_tinfo[i].cmds,
+					 sc->sc_tinfo[i].dconns,
+					 sc->sc_tinfo[i].senses,
+					 sc->sc_tinfo[i].lubusy);
+		}
+	}
+	splx(s);
+}
+#endif