OpenBSD/luna88k Work in progress: NEC PC-9801-100 aic(4) on cbus(4)

obsd-luna88k-aic-cbus.diff

Index: sys/arch/luna88k/cbus/aic6360_cbus.c
===================================================================
RCS file: sys/arch/luna88k/cbus/aic6360_cbus.c
diff -N sys/arch/luna88k/cbus/aic6360_cbus.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ sys/arch/luna88k/cbus/aic6360_cbus.c	17 Aug 2020 11:55:33 -0000
@@ -0,0 +1,2102 @@
+/*	$OpenBSD: aic6360.c,v 1.37 2020/07/20 14:41:13 krw Exp $	*/
+/*	$NetBSD: aic6360.c,v 1.52 1996/12/10 21:27:51 thorpej Exp $	*/
+
+#ifdef DDB
+#define	integrate
+#else
+#define	integrate	static inline
+#endif
+
+/*
+ * Copyright (c) 1994, 1995, 1996 Charles Hannum.  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 Charles M. Hannum.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Copyright (c) 1994 Jarle Greipsland
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ */
+
+/*
+ * Acknowledgements: Many of the algorithms used in this driver are
+ * inspired by the work of Julian Elischer ([email protected]) and
+ * Charles Hannum ([email protected]).  Thanks a million!
+ */
+
+/* TODO list:
+ * 1) Get the DMA stuff working.
+ * 2) Get the iov/uio stuff working. Is this a good thing ???
+ * 3) Get the synch stuff working.
+ * 4) Rewrite it to use malloc for the acb structs instead of static alloc.?
+ */
+
+/*
+ * A few customizable items:
+ */
+
+/* Use doubleword transfers to/from SCSI chip.  Note: This requires
+ * motherboard support.  Basicly, some motherboard chipsets are able to
+ * split a 32 bit I/O operation into two 16 bit I/O operations,
+ * transparently to the processor.  This speeds up some things, notably long
+ * data transfers.
+ */
+#define AIC_USE_DWORDS		0
+
+/* Synchronous data transfers? */
+#define AIC_USE_SYNCHRONOUS	0
+#define AIC_SYNC_REQ_ACK_OFS 	8
+
+/* Wide data transfers? */
+#define	AIC_USE_WIDE		0
+#define	AIC_MAX_WIDTH		0
+
+/* Max attempts made to transmit a message */
+#define AIC_MSG_MAX_ATTEMPT	3 /* Not used now XXX */
+
+/* Use DMA (else we do programmed I/O using string instructions) (not yet!)*/
+#define AIC_USE_EISA_DMA	0
+#define AIC_USE_ISA_DMA		0
+
+/* How to behave on the (E)ISA bus when/if DMAing (on<<4) + off in us */
+#define EISA_BRST_TIM ((15<<4) + 1)	/* 15us on, 1us off */
+
+/* Some spin loop parameters (essentially how long to wait some places)
+ * The problem(?) is that sometimes we expect either to be able to transmit a
+ * byte or to get a new one from the SCSI bus pretty soon.  In order to avoid
+ * returning from the interrupt just to get yanked back for the next byte we
+ * may spin in the interrupt routine waiting for this byte to come.  How long?
+ * This is really (SCSI) device and processor dependent.  Tuneable, I guess.
+ */
+#define AIC_MSGIN_SPIN		1 	/* Spin upto ?ms for a new msg byte */
+#define AIC_MSGOUT_SPIN		1
+
+/* Include debug functions?  At the end of this file there are a bunch of
+ * functions that will print out various information regarding queued SCSI
+ * commands, driver state and chip contents.  You can call them from the
+ * kernel debugger.  If you set AIC_DEBUG to 0 they are not included (the
+ * kernel uses less memory) but you lose the debugging facilities.
+ */
+#ifndef SMALL_KERNEL
+#define AIC_DEBUG		1
+#endif
+
+#define	AIC_ABORT_TIMEOUT	2000	/* time to wait for abort */
+
+/* End of customizable parameters */
+
+#if AIC_USE_EISA_DMA || AIC_USE_ISA_DMA
+#error "I said not yet! Start paying attention... grumble"
+#endif
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/device.h>
+#include <sys/buf.h>
+#include <sys/queue.h>
+
+#include <machine/bus.h>
+#include <machine/intr.h>
+
+#include <scsi/scsi_all.h>
+#include <scsi/scsi_message.h>
+#include <scsi/scsiconf.h>
+
+#if 0
+#include <dev/isa/isavar.h>
+#else
+#include <arch/luna88k/cbus/cbusvar.h>
+#endif
+
+#include <dev/ic/aic6360reg.h>
+#include <dev/ic/aic6360var.h>
+
+#ifndef DDB
+#define	db_enter() panic("should call debugger here (aic6360.c)")
+#endif /* ! DDB */
+
+#ifdef AIC_DEBUG
+#if 0
+int aic_debug = 0x00; /* AIC_SHOWSTART|AIC_SHOWMISC|AIC_SHOWTRACE; */
+#else
+int aic_debug = AIC_SHOWSTART|AIC_SHOWMISC|AIC_SHOWTRACE;
+#endif
+#endif
+
+void 	aic_init(struct aic_softc *);
+void	aic_done(struct aic_softc *, struct aic_acb *);
+void	aic_dequeue(struct aic_softc *, struct aic_acb *);
+void	aic_scsi_cmd(struct scsi_xfer *);
+int	aic_poll(struct aic_softc *, struct scsi_xfer *, int);
+integrate void	aic_sched_msgout(struct aic_softc *, u_char);
+integrate void	aic_setsync(struct aic_softc *, struct aic_tinfo *);
+void	aic_select(struct aic_softc *, struct aic_acb *);
+void	aic_timeout(void *);
+void	aic_sched(struct aic_softc *);
+void	aic_scsi_reset(struct aic_softc *);
+void	aic_reset(struct aic_softc *);
+void	aic_acb_free(void *, void *);
+void	*aic_acb_alloc(void *);
+int	aic_reselect(struct aic_softc *, int);
+void	aic_sense(struct aic_softc *, struct aic_acb *);
+void	aic_msgin(struct aic_softc *);
+void	aic_abort(struct aic_softc *, struct aic_acb *);
+void	aic_msgout(struct aic_softc *);
+int	aic_dataout_pio(struct aic_softc *, u_char *, int);
+int	aic_datain_pio(struct aic_softc *, u_char *, int);
+#ifdef AIC_DEBUG
+void	aic_print_acb(struct aic_acb *);
+void	aic_dump_driver(struct aic_softc *);
+void	aic_dump6360(struct aic_softc *);
+void	aic_show_scsi_cmd(struct aic_acb *);
+void	aic_print_active_acb(void);
+#endif
+
+struct cfdriver aic_cd = {
+	NULL, "aic", DV_DULL
+};
+
+struct scsi_adapter aic_switch = {
+	aic_scsi_cmd, NULL, NULL, NULL, NULL
+};
+
+/*
+ * Do the real search-for-device.
+ */
+int
+aic_find(bus_space_tag_t iot, bus_space_handle_t ioh)
+{
+	char chip_id[sizeof(IDSTRING)];	/* For chips that support it */
+	int i;
+
+	/* Remove aic6360 from possible powerdown mode */
+	bus_space_write_1(iot, ioh, DMACNTRL0, 0);
+
+	/* Thanks to [email protected] for the new method for detecting
+	 * whether the chip is present or not.  Bonus: may also work for
+	 * the AIC-6260!
+ 	 */
+	AIC_TRACE(("aic: probing for aic-chip\n"));
+ 	/*
+ 	 * Linux also init's the stack to 1-16 and then clears it,
+     	 *  6260's don't appear to have an ID reg - mpg
+ 	 */
+	/* Push the sequence 0,1,..,15 on the stack */
+#define STSIZE 16
+	bus_space_write_1(iot, ioh, DMACNTRL1, 0); /* Reset stack pointer */
+	for (i = 0; i < STSIZE; i++)
+		bus_space_write_1(iot, ioh, STACK, i);
+
+	/* See if we can pull out the same sequence */
+	bus_space_write_1(iot, ioh, DMACNTRL1, 0);
+ 	for (i = 0; i < STSIZE && bus_space_read_1(iot, ioh, STACK) == i; i++)
+		;
+	if (i != STSIZE) {
+		AIC_START(("STACK futzed at %d.\n", i));
+		return (0);
+	}
+
+	/* See if we can pull the id string out of the ID register,
+	 * now only used for informational purposes.
+	 */
+	bzero(chip_id, sizeof(chip_id));
+	bus_space_read_multi_1(iot, ioh, ID, chip_id, sizeof(IDSTRING) - 1);
+	AIC_START(("AIC ID: %s ", chip_id));
+	AIC_START(("chip revision %d\n",
+	    (int)bus_space_read_1(iot, ioh, REV)));
+
+	return (1);
+}
+
+/*
+ * Attach the AIC6360, fill out some high and low level data structures
+ */
+void
+aicattach(struct aic_softc *sc)
+{
+	struct scsibus_attach_args saa;
+	AIC_TRACE(("aicattach  "));
+	sc->sc_state = AIC_INIT;
+
+	sc->sc_initiator = 7;
+	sc->sc_freq = 20;	/* XXXX assume 20 MHz. */
+
+	/*
+	 * These are the bounds of the sync period, based on the frequency of
+	 * the chip's clock input and the size and offset of the sync period
+	 * register.
+	 *
+	 * For a 20MHz clock, this gives us 25, or 100nS, or 10MB/s, as a
+	 * maximum transfer rate, and 112.5, or 450nS, or 2.22MB/s, as a
+	 * minimum transfer rate.
+	 */
+	sc->sc_minsync = (2 * 250) / sc->sc_freq;
+	sc->sc_maxsync = (9 * 250) / sc->sc_freq;
+
+	aic_init(sc);	/* init chip and driver */
+
+	saa.saa_adapter_softc = sc;
+	saa.saa_adapter_target = sc->sc_initiator;
+	saa.saa_adapter = &aic_switch;
+	saa.saa_luns = saa.saa_adapter_buswidth = 8;
+	saa.saa_openings = 2;
+	saa.saa_pool = &sc->sc_iopool;
+	saa.saa_quirks = saa.saa_flags = 0;
+	saa.saa_wwpn = saa.saa_wwnn = 0;
+
+	config_found(&sc->sc_dev, &saa, scsiprint);
+}
+
+int
+aic_detach(struct device *self, int flags)
+{
+	struct aic_softc *sc = (struct aic_softc *) self;
+	int rv = 0;
+
+	rv = config_detach_children(&sc->sc_dev, flags);
+
+	return (rv);
+}
+
+/* Initialize AIC6360 chip itself
+ * The following conditions should hold:
+ * aicprobe should have succeeded, i.e. the ioh handle in aic_softc must
+ * be valid.
+ */
+void
+aic_reset(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+
+	/*
+	 * Doc. recommends to clear these two registers before operations
+	 * commence
+	 */
+	bus_space_write_1(iot, ioh, SCSITEST, 0);
+	bus_space_write_1(iot, ioh, TEST, 0);
+
+	/* Reset SCSI-FIFO and abort any transfers */
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | CLRCH | CLRSTCNT);
+
+	/* Reset DMA-FIFO */
+	bus_space_write_1(iot, ioh, DMACNTRL0, RSTFIFO);
+	bus_space_write_1(iot, ioh, DMACNTRL1, 0);
+
+	/* Disable all selection features */
+	bus_space_write_1(iot, ioh, SCSISEQ, 0);
+	bus_space_write_1(iot, ioh, SXFRCTL1, 0);
+
+	/* Disable some interrupts */
+	bus_space_write_1(iot, ioh, SIMODE0, 0x00);
+	/* Clear a slew of interrupts */
+	bus_space_write_1(iot, ioh, CLRSINT0, 0x7f);
+
+	/* Disable some more interrupts */
+	bus_space_write_1(iot, ioh, SIMODE1, 0x00);
+	/* Clear another slew of interrupts */
+	bus_space_write_1(iot, ioh, CLRSINT1, 0xef);
+
+	/* Disable synchronous transfers */
+	bus_space_write_1(iot, ioh, SCSIRATE, 0);
+
+	/* Haven't seen ant errors (yet) */
+	bus_space_write_1(iot, ioh, CLRSERR, 0x07);
+
+	/* Set our SCSI-ID */
+	bus_space_write_1(iot, ioh, SCSIID, sc->sc_initiator << OID_S);
+	bus_space_write_1(iot, ioh, BRSTCNTRL, EISA_BRST_TIM);
+}
+
+/* Pull the SCSI RST line for 500 us */
+void
+aic_scsi_reset(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+
+	bus_space_write_1(iot, ioh, SCSISEQ, SCSIRSTO);
+	delay(500);
+	bus_space_write_1(iot, ioh, SCSISEQ, 0);
+	delay(50);
+}
+
+/*
+ * Initialize aic SCSI driver.
+ */
+void
+aic_init(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	struct aic_acb *acb;
+	int r;
+
+	aic_reset(sc);
+	aic_scsi_reset(sc);
+	aic_reset(sc);
+
+	if (sc->sc_state == AIC_INIT) {
+		/* First time through; initialize. */
+		TAILQ_INIT(&sc->ready_list);
+		TAILQ_INIT(&sc->nexus_list);
+		TAILQ_INIT(&sc->free_list);
+		mtx_init(&sc->sc_acb_mtx, IPL_BIO);
+		scsi_iopool_init(&sc->sc_iopool, sc, aic_acb_alloc,
+		    aic_acb_free);
+		sc->sc_nexus = NULL;
+		acb = sc->sc_acb;
+		bzero(acb, sizeof(sc->sc_acb));
+		for (r = 0; r < sizeof(sc->sc_acb) / sizeof(*acb); r++) {
+			TAILQ_INSERT_TAIL(&sc->free_list, acb, chain);
+			acb++;
+		}
+		bzero(&sc->sc_tinfo, sizeof(sc->sc_tinfo));
+	} else {
+		/* Cancel any active commands. */
+		sc->sc_state = AIC_CLEANING;
+		if ((acb = sc->sc_nexus) != NULL) {
+			acb->xs->error = XS_DRIVER_STUFFUP;
+			timeout_del(&acb->xs->stimeout);
+			aic_done(sc, acb);
+		}
+		while ((acb = TAILQ_FIRST(&sc->nexus_list)) != NULL) {
+			acb->xs->error = XS_DRIVER_STUFFUP;
+			timeout_del(&acb->xs->stimeout);
+			aic_done(sc, acb);
+		}
+	}
+
+	sc->sc_prevphase = PH_INVALID;
+	for (r = 0; r < 8; r++) {
+		struct aic_tinfo *ti = &sc->sc_tinfo[r];
+
+		ti->flags = 0;
+#if AIC_USE_SYNCHRONOUS
+		ti->flags |= DO_SYNC;
+		ti->period = sc->sc_minsync;
+		ti->offset = AIC_SYNC_REQ_ACK_OFS;
+#else
+		ti->period = ti->offset = 0;
+#endif
+#if AIC_USE_WIDE
+		ti->flags |= DO_WIDE;
+		ti->width = AIC_MAX_WIDTH;
+#else
+		ti->width = 0;
+#endif
+	}
+
+	sc->sc_state = AIC_IDLE;
+	bus_space_write_1(iot, ioh, DMACNTRL0, INTEN);
+}
+
+void
+aic_acb_free(void *xsc, void *xacb)
+{
+	struct aic_softc *sc = xsc;
+	struct aic_acb *acb = xacb;
+
+	mtx_enter(&sc->sc_acb_mtx);
+	acb->flags = 0;
+	TAILQ_INSERT_HEAD(&sc->free_list, acb, chain);
+	mtx_leave(&sc->sc_acb_mtx);
+}
+
+void *
+aic_acb_alloc(void *xsc)
+{
+	struct aic_softc *sc = xsc;
+	struct aic_acb *acb;
+
+	mtx_enter(&sc->sc_acb_mtx);
+	acb = TAILQ_FIRST(&sc->free_list);
+	if (acb) {
+		TAILQ_REMOVE(&sc->free_list, acb, chain);
+		acb->flags |= ACB_ALLOC;
+	}
+	mtx_leave(&sc->sc_acb_mtx);
+
+	return acb;
+}
+
+/*
+ * DRIVER FUNCTIONS CALLABLE FROM HIGHER LEVEL DRIVERS
+ */
+
+/*
+ * Expected sequence:
+ * 1) Command inserted into ready list
+ * 2) Command selected for execution
+ * 3) Command won arbitration and has selected target device
+ * 4) Send message out (identify message, eventually also sync.negotiations)
+ * 5) Send command
+ * 5a) Receive disconnect message, disconnect.
+ * 5b) Reselected by target
+ * 5c) Receive identify message from target.
+ * 6) Send or receive data
+ * 7) Receive status
+ * 8) Receive message (command complete etc.)
+ * 9) If status == SCSI_CHECK construct a synthetic request sense SCSI cmd.
+ *    Repeat 2-8 (no disconnects please...)
+ */
+
+/*
+ * Start a SCSI-command
+ * This function is called by the higher level SCSI-driver to queue/run
+ * SCSI-commands.
+ */
+void
+aic_scsi_cmd(struct scsi_xfer *xs)
+{
+	struct scsi_link *sc_link = xs->sc_link;
+	struct aic_softc *sc = sc_link->bus->sb_adapter_softc;
+	struct aic_acb *acb;
+	int s, flags;
+
+	AIC_TRACE(("aic_scsi_cmd  "));
+	AIC_CMDS(("[0x%x, %d]->%d ", (int)xs->cmd->opcode, xs->cmdlen,
+	    sc_link->target));
+
+	flags = xs->flags;
+	acb = xs->io;
+
+	/* Initialize acb */
+	acb->xs = xs;
+	acb->timeout = xs->timeout;
+	timeout_set(&xs->stimeout, aic_timeout, acb);
+
+	if (xs->flags & SCSI_RESET) {
+		acb->flags |= ACB_RESET;
+		acb->scsi_cmd_length = 0;
+		acb->data_length = 0;
+	} else {
+		bcopy(xs->cmd, &acb->scsi_cmd, xs->cmdlen);
+		acb->scsi_cmd_length = xs->cmdlen;
+		acb->data_addr = xs->data;
+		acb->data_length = xs->datalen;
+	}
+	acb->target_stat = 0;
+
+	s = splbio();
+
+	TAILQ_INSERT_TAIL(&sc->ready_list, acb, chain);
+	if (sc->sc_state == AIC_IDLE)
+		aic_sched(sc);
+
+	splx(s);
+
+	if ((flags & SCSI_POLL) == 0)
+		return;
+
+	/* Not allowed to use interrupts, use polling instead */
+	if (aic_poll(sc, xs, acb->timeout)) {
+		aic_timeout(acb);
+		if (aic_poll(sc, xs, acb->timeout))
+			aic_timeout(acb);
+	}
+}
+
+/*
+ * Used when interrupt driven I/O isn't allowed, e.g. during boot.
+ */
+int
+aic_poll(struct aic_softc *sc, struct scsi_xfer *xs, int count)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	int s;
+
+	AIC_TRACE(("aic_poll  "));
+	while (count) {
+		/*
+		 * If we had interrupts enabled, would we
+		 * have got an interrupt?
+		 */
+		if ((bus_space_read_1(iot, ioh, DMASTAT) & INTSTAT) != 0) {
+			s = splbio();
+			aicintr(sc);
+			splx(s);
+		}
+		if ((xs->flags & ITSDONE) != 0)
+			return 0;
+		delay(1000);
+		count--;
+	}
+	return 1;
+}
+
+/*
+ * LOW LEVEL SCSI UTILITIES
+ */
+
+integrate void
+aic_sched_msgout(struct aic_softc *sc, u_char m)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+
+	if (sc->sc_msgpriq == 0)
+		bus_space_write_1(iot, ioh, SCSISIG, sc->sc_phase | ATNO);
+	sc->sc_msgpriq |= m;
+}
+
+/*
+ * Set synchronous transfer offset and period.
+ */
+integrate void
+aic_setsync(struct aic_softc *sc, struct aic_tinfo *ti)
+{
+#if AIC_USE_SYNCHRONOUS
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+
+	if (ti->offset != 0)
+		bus_space_write_1(iot, ioh, SCSIRATE,
+		    ((ti->period * sc->sc_freq) / 250 - 2) << 4 | ti->offset);
+	else
+		bus_space_write_1(iot, ioh, SCSIRATE, 0);
+#endif
+}
+
+/*
+ * Start a selection.  This is used by aic_sched() to select an idle target,
+ * and by aic_done() to immediately reselect a target to get sense information.
+ */
+void
+aic_select(struct aic_softc *sc, struct aic_acb *acb)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	struct scsi_link *sc_link = acb->xs->sc_link;
+	int target = sc_link->target;
+	struct aic_tinfo *ti = &sc->sc_tinfo[target];
+
+	bus_space_write_1(iot, ioh, SCSIID,
+	    sc->sc_initiator << OID_S | target);
+	aic_setsync(sc, ti);
+	bus_space_write_1(iot, ioh, SXFRCTL1, STIMO_256ms | ENSTIMER);
+
+	/* Always enable reselections. */
+	bus_space_write_1(iot, ioh, SIMODE0, ENSELDI | ENSELDO);
+	bus_space_write_1(iot, ioh, SIMODE1, ENSCSIRST | ENSELTIMO);
+	bus_space_write_1(iot, ioh, SCSISEQ, ENRESELI | ENSELO | ENAUTOATNO);
+
+	sc->sc_state = AIC_SELECTING;
+}
+
+int
+aic_reselect(struct aic_softc *sc, int message)
+{
+	u_char selid, target, lun;
+	struct aic_acb *acb;
+	struct scsi_link *sc_link;
+	struct aic_tinfo *ti;
+
+	/*
+	 * The SCSI chip made a snapshot of the data bus while the reselection
+	 * was being negotiated.  This enables us to determine which target did
+	 * the reselect.
+	 */
+	selid = sc->sc_selid & ~(1 << sc->sc_initiator);
+	if (selid & (selid - 1)) {
+		printf("%s: reselect with invalid selid %02x; ",
+		    sc->sc_dev.dv_xname, selid);
+		printf("sending DEVICE RESET\n");
+		AIC_BREAK();
+		goto reset;
+	}
+
+	/* Search wait queue for disconnected cmd
+	 * The list should be short, so I haven't bothered with
+	 * any more sophisticated structures than a simple
+	 * singly linked list.
+	 */
+	target = ffs(selid) - 1;
+	lun = message & 0x07;
+	TAILQ_FOREACH(acb, &sc->nexus_list, chain) {
+		sc_link = acb->xs->sc_link;
+		if (sc_link->target == target && sc_link->lun == lun)
+			break;
+	}
+	if (acb == NULL) {
+		printf("%s: reselect from target %d lun %d with no nexus; ",
+		    sc->sc_dev.dv_xname, target, lun);
+		printf("sending ABORT\n");
+		AIC_BREAK();
+		goto abort;
+	}
+
+	/* Make this nexus active again. */
+	TAILQ_REMOVE(&sc->nexus_list, acb, chain);
+	sc->sc_state = AIC_CONNECTED;
+	sc->sc_nexus = acb;
+	ti = &sc->sc_tinfo[target];
+	ti->lubusy |= (1 << lun);
+	aic_setsync(sc, ti);
+
+	if (acb->flags & ACB_RESET)
+		aic_sched_msgout(sc, SEND_DEV_RESET);
+	else if (acb->flags & ACB_ABORT)
+		aic_sched_msgout(sc, SEND_ABORT);
+
+	/* Do an implicit RESTORE POINTERS. */
+	sc->sc_dp = acb->data_addr;
+	sc->sc_dleft = acb->data_length;
+	sc->sc_cp = (u_char *)&acb->scsi_cmd;
+	sc->sc_cleft = acb->scsi_cmd_length;
+
+	return (0);
+
+reset:
+	aic_sched_msgout(sc, SEND_DEV_RESET);
+	return (1);
+
+abort:
+	aic_sched_msgout(sc, SEND_ABORT);
+	return (1);
+}
+
+/*
+ * Schedule a SCSI operation.  This has now been pulled out of the interrupt
+ * handler so that we may call it from aic_scsi_cmd and aic_done.  This may
+ * save us an unnecessary interrupt just to get things going.  Should only be
+ * called when state == AIC_IDLE and at bio pl.
+ */
+void
+aic_sched(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	struct aic_acb *acb;
+	struct scsi_link *sc_link;
+	struct aic_tinfo *ti;
+
+	/*
+	 * Find first acb in ready queue that is for a target/lunit pair that
+	 * is not busy.
+	 */
+	bus_space_write_1(iot, ioh, CLRSINT1,
+	    CLRSELTIMO | CLRBUSFREE | CLRSCSIPERR);
+	TAILQ_FOREACH(acb, &sc->ready_list, chain) {
+		sc_link = acb->xs->sc_link;
+		ti = &sc->sc_tinfo[sc_link->target];
+		if ((ti->lubusy & (1 << sc_link->lun)) == 0) {
+			AIC_MISC(("selecting %d:%d  ",
+			    sc_link->target, sc_link->lun));
+			TAILQ_REMOVE(&sc->ready_list, acb, chain);
+			sc->sc_nexus = acb;
+			aic_select(sc, acb);
+			return;
+		} else
+			AIC_MISC(("%d:%d busy\n",
+			    sc_link->target, sc_link->lun));
+	}
+	AIC_MISC(("idle  "));
+	/* Nothing to start; just enable reselections and wait. */
+	bus_space_write_1(iot, ioh, SIMODE0, ENSELDI);
+	bus_space_write_1(iot, ioh, SIMODE1, ENSCSIRST);
+	bus_space_write_1(iot, ioh, SCSISEQ, ENRESELI);
+}
+
+void
+aic_sense(struct aic_softc *sc, struct aic_acb *acb)
+{
+	struct scsi_xfer *xs = acb->xs;
+	struct scsi_link *sc_link = xs->sc_link;
+	struct aic_tinfo *ti = &sc->sc_tinfo[sc_link->target];
+	struct scsi_sense *ss = (void *)&acb->scsi_cmd;
+
+	AIC_MISC(("requesting sense  "));
+	/* Next, setup a request sense command block */
+	bzero(ss, sizeof(*ss));
+	ss->opcode = REQUEST_SENSE;
+	ss->byte2 = sc_link->lun << 5;
+	ss->length = sizeof(struct scsi_sense_data);
+	acb->scsi_cmd_length = sizeof(*ss);
+	acb->data_addr = (char *)&xs->sense;
+	acb->data_length = sizeof(struct scsi_sense_data);
+	acb->flags |= ACB_SENSE;
+	ti->senses++;
+	if (acb->flags & ACB_NEXUS)
+		ti->lubusy &= ~(1 << sc_link->lun);
+	if (acb == sc->sc_nexus) {
+		aic_select(sc, acb);
+	} else {
+		aic_dequeue(sc, acb);
+		TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
+		if (sc->sc_state == AIC_IDLE)
+			aic_sched(sc);
+	}
+}
+
+/*
+ * POST PROCESSING OF SCSI_CMD (usually current)
+ */
+void
+aic_done(struct aic_softc *sc, struct aic_acb *acb)
+{
+	struct scsi_xfer *xs = acb->xs;
+	struct scsi_link *sc_link = xs->sc_link;
+	struct aic_tinfo *ti = &sc->sc_tinfo[sc_link->target];
+
+	AIC_TRACE(("aic_done  "));
+
+	/*
+	 * Now, if we've come here with no error code, i.e. we've kept the
+	 * initial XS_NOERROR, and the status code signals that we should
+	 * check sense, we'll need to set up a request sense cmd block and
+	 * push the command back into the ready queue *before* any other
+	 * commands for this target/lunit, else we lose the sense info.
+	 * We don't support chk sense conditions for the request sense cmd.
+	 */
+	if (xs->error == XS_NOERROR) {
+		if (acb->flags & ACB_ABORT) {
+			xs->error = XS_DRIVER_STUFFUP;
+		} else if (acb->flags & ACB_SENSE) {
+			xs->error = XS_SENSE;
+		} else if (acb->target_stat == SCSI_CHECK) {
+			/* First, save the return values */
+			xs->resid = acb->data_length;
+			xs->status = acb->target_stat;
+			aic_sense(sc, acb);
+			return;
+		} else {
+			xs->resid = acb->data_length;
+		}
+	}
+
+#ifdef AIC_DEBUG
+	if ((aic_debug & AIC_SHOWMISC) != 0) {
+		if (xs->resid != 0)
+			printf("resid=%lu ", (u_long)xs->resid);
+		if (xs->error == XS_SENSE)
+			printf("sense=0x%02x\n", xs->sense.error_code);
+		else
+			printf("error=%d\n", xs->error);
+	}
+#endif
+
+	/*
+	 * Remove the ACB from whatever queue it happens to be on.
+	 */
+	if (acb->flags & ACB_NEXUS)
+		ti->lubusy &= ~(1 << sc_link->lun);
+	if (acb == sc->sc_nexus) {
+		sc->sc_nexus = NULL;
+		sc->sc_state = AIC_IDLE;
+		aic_sched(sc);
+	} else
+		aic_dequeue(sc, acb);
+
+	ti->cmds++;
+	scsi_done(xs);
+}
+
+void
+aic_dequeue(struct aic_softc *sc, struct aic_acb *acb)
+{
+
+	if (acb->flags & ACB_NEXUS) {
+		TAILQ_REMOVE(&sc->nexus_list, acb, chain);
+	} else {
+		TAILQ_REMOVE(&sc->ready_list, acb, chain);
+	}
+}
+
+/*
+ * INTERRUPT/PROTOCOL ENGINE
+ */
+
+/*
+ * Precondition:
+ * The SCSI bus is already in the MSGI phase and there is a message byte
+ * on the bus, along with an asserted REQ signal.
+ */
+void
+aic_msgin(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	u_char sstat1;
+	int n;
+
+	AIC_TRACE(("aic_msgin  "));
+
+	if (sc->sc_prevphase == PH_MSGIN) {
+		/* This is a continuation of the previous message. */
+		n = sc->sc_imp - sc->sc_imess;
+		goto nextbyte;
+	}
+
+	/* This is a new MESSAGE IN phase.  Clean up our state. */
+	sc->sc_flags &= ~AIC_DROP_MSGIN;
+
+nextmsg:
+	n = 0;
+	sc->sc_imp = &sc->sc_imess[n];
+
+nextbyte:
+	/*
+	 * Read a whole message, but don't ack the last byte.  If we reject the
+	 * message, we have to assert ATN during the message transfer phase
+	 * itself.
+	 */
+	for (;;) {
+		for (;;) {
+			sstat1 = bus_space_read_1(iot, ioh, SSTAT1);
+			if ((sstat1 & (REQINIT | PHASECHG | BUSFREE)) != 0)
+				break;
+			/* Wait for REQINIT.  XXX Need timeout. */
+		}
+		if ((sstat1 & (PHASECHG | BUSFREE)) != 0) {
+			/*
+			 * Target left MESSAGE IN, probably because it
+			 * a) noticed our ATN signal, or
+			 * b) ran out of messages.
+			 */
+			goto out;
+		}
+
+		/* If parity error, just dump everything on the floor. */
+		if ((sstat1 & SCSIPERR) != 0) {
+			sc->sc_flags |= AIC_DROP_MSGIN;
+			aic_sched_msgout(sc, SEND_PARITY_ERROR);
+		}
+
+		/* Gather incoming message bytes if needed. */
+		if ((sc->sc_flags & AIC_DROP_MSGIN) == 0) {
+			if (n >= AIC_MAX_MSG_LEN) {
+				(void) bus_space_read_1(iot, ioh, SCSIDAT);
+				sc->sc_flags |= AIC_DROP_MSGIN;
+				aic_sched_msgout(sc, SEND_REJECT);
+			} else {
+				*sc->sc_imp++ = bus_space_read_1(iot, ioh,
+				    SCSIDAT);
+				n++;
+				/*
+				 * This testing is suboptimal, but most
+				 * messages will be of the one byte variety, so
+				 * it should not affect performance
+				 * significantly.
+				 */
+				if (n == 1 && IS1BYTEMSG(sc->sc_imess[0]))
+					break;
+				if (n == 2 && IS2BYTEMSG(sc->sc_imess[0]))
+					break;
+				if (n >= 3 && ISEXTMSG(sc->sc_imess[0]) &&
+				    n == sc->sc_imess[1] + 2)
+					break;
+			}
+		} else
+			(void) bus_space_read_1(iot, ioh, SCSIDAT);
+
+		/*
+		 * If we reach this spot we're either:
+		 * a) in the middle of a multi-byte message, or
+		 * b) dropping bytes.
+		 */
+		bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | SPIOEN);
+		/* Ack the last byte read. */
+		(void) bus_space_read_1(iot, ioh, SCSIDAT);
+		bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+		while ((bus_space_read_1(iot, ioh, SCSISIG) & ACKI) != 0)
+			;
+	}
+
+	AIC_MISC(("n=%d imess=0x%02x  ", n, sc->sc_imess[0]));
+
+	/* We now have a complete message.  Parse it. */
+	switch (sc->sc_state) {
+		struct aic_acb *acb;
+		struct scsi_link *sc_link;
+		struct aic_tinfo *ti;
+
+	case AIC_CONNECTED:
+		AIC_ASSERT(sc->sc_nexus != NULL);
+		acb = sc->sc_nexus;
+		ti = &sc->sc_tinfo[acb->xs->sc_link->target];
+
+		switch (sc->sc_imess[0]) {
+		case MSG_CMDCOMPLETE:
+			if ((long)sc->sc_dleft < 0) {
+				sc_link = acb->xs->sc_link;
+				printf("%s: %lu extra bytes from %d:%d\n",
+				    sc->sc_dev.dv_xname, (u_long)-sc->sc_dleft,
+				    sc_link->target, sc_link->lun);
+				acb->data_length = 0;
+			}
+			acb->xs->resid = acb->data_length = sc->sc_dleft;
+			sc->sc_state = AIC_CMDCOMPLETE;
+			break;
+
+		case MSG_PARITY_ERROR:
+			/* Resend the last message. */
+			aic_sched_msgout(sc, sc->sc_lastmsg);
+			break;
+
+		case MSG_MESSAGE_REJECT:
+			AIC_MISC(("message rejected %02x  ", sc->sc_lastmsg));
+			switch (sc->sc_lastmsg) {
+#if AIC_USE_SYNCHRONOUS + AIC_USE_WIDE
+			case SEND_IDENTIFY:
+				ti->flags &= ~(DO_SYNC | DO_WIDE);
+				ti->period = ti->offset = 0;
+				aic_setsync(sc, ti);
+				ti->width = 0;
+				break;
+#endif
+#if AIC_USE_SYNCHRONOUS
+			case SEND_SDTR:
+				ti->flags &= ~DO_SYNC;
+				ti->period = ti->offset = 0;
+				aic_setsync(sc, ti);
+				break;
+#endif
+#if AIC_USE_WIDE
+			case SEND_WDTR:
+				ti->flags &= ~DO_WIDE;
+				ti->width = 0;
+				break;
+#endif
+			case SEND_INIT_DET_ERR:
+				aic_sched_msgout(sc, SEND_ABORT);
+				break;
+			}
+			break;
+
+		case MSG_NOOP:
+			break;
+
+		case MSG_DISCONNECT:
+			ti->dconns++;
+			sc->sc_state = AIC_DISCONNECT;
+			break;
+
+		case MSG_SAVEDATAPOINTER:
+			acb->data_addr = sc->sc_dp;
+			acb->data_length = sc->sc_dleft;
+			break;
+
+		case MSG_RESTOREPOINTERS:
+			sc->sc_dp = acb->data_addr;
+			sc->sc_dleft = acb->data_length;
+			sc->sc_cp = (u_char *)&acb->scsi_cmd;
+			sc->sc_cleft = acb->scsi_cmd_length;
+			break;
+
+		case MSG_EXTENDED:
+			switch (sc->sc_imess[2]) {
+#if AIC_USE_SYNCHRONOUS
+			case MSG_EXT_SDTR:
+				if (sc->sc_imess[1] != 3)
+					goto reject;
+				ti->period = sc->sc_imess[3];
+				ti->offset = sc->sc_imess[4];
+				ti->flags &= ~DO_SYNC;
+				if (ti->offset == 0) {
+				} else if (ti->period < sc->sc_minsync ||
+				    ti->period > sc->sc_maxsync ||
+				    ti->offset > 8) {
+					ti->period = ti->offset = 0;
+					aic_sched_msgout(sc, SEND_SDTR);
+				} else {
+					sc_print_addr(acb->xs->sc_link);
+					printf("sync, offset %d, ",
+					    ti->offset);
+					printf("period %dnsec\n",
+					    ti->period * 4);
+				}
+				aic_setsync(sc, ti);
+				break;
+#endif
+
+#if AIC_USE_WIDE
+			case MSG_EXT_WDTR:
+				if (sc->sc_imess[1] != 2)
+					goto reject;
+				ti->width = sc->sc_imess[3];
+				ti->flags &= ~DO_WIDE;
+				if (ti->width == 0) {
+				} else if (ti->width > AIC_MAX_WIDTH) {
+					ti->width = 0;
+					aic_sched_msgout(sc, SEND_WDTR);
+				} else {
+					sc_print_addr(acb->xs->sc_link);
+					printf("wide, width %d\n",
+					    1 << (3 + ti->width));
+				}
+				break;
+#endif
+
+			default:
+				printf("%s: unrecognized MESSAGE EXTENDED; ",
+				    sc->sc_dev.dv_xname);
+				printf("sending REJECT\n");
+				AIC_BREAK();
+				goto reject;
+			}
+			break;
+
+		default:
+			printf("%s: unrecognized MESSAGE; sending REJECT\n",
+			    sc->sc_dev.dv_xname);
+			AIC_BREAK();
+		reject:
+			aic_sched_msgout(sc, SEND_REJECT);
+			break;
+		}
+		break;
+
+	case AIC_RESELECTED:
+		if (!MSG_ISIDENTIFY(sc->sc_imess[0])) {
+			printf("%s: reselect without IDENTIFY; ",
+			    sc->sc_dev.dv_xname);
+			printf("sending DEVICE RESET\n");
+			AIC_BREAK();
+			goto reset;
+		}
+
+		(void) aic_reselect(sc, sc->sc_imess[0]);
+		break;
+
+	default:
+		printf("%s: unexpected MESSAGE IN; sending DEVICE RESET\n",
+		    sc->sc_dev.dv_xname);
+		AIC_BREAK();
+	reset:
+		aic_sched_msgout(sc, SEND_DEV_RESET);
+		break;
+
+#ifdef notdef
+	abort:
+		aic_sched_msgout(sc, SEND_ABORT);
+		break;
+#endif
+	}
+
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | SPIOEN);
+	/* Ack the last message byte. */
+	(void) bus_space_read_1(iot, ioh, SCSIDAT);
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+	while ((bus_space_read_1(iot, ioh, SCSISIG) & ACKI) != 0)
+		;
+
+	/* Go get the next message, if any. */
+	goto nextmsg;
+
+out:
+	AIC_MISC(("n=%d imess=0x%02x  ", n, sc->sc_imess[0]));
+}
+
+/*
+ * Send the highest priority, scheduled message.
+ */
+void
+aic_msgout(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+#if AIC_USE_SYNCHRONOUS
+	struct aic_tinfo *ti;
+#endif
+	u_char sstat1;
+	int n;
+
+	AIC_TRACE(("aic_msgout  "));
+
+	/* Reset the FIFO. */
+	bus_space_write_1(iot, ioh, DMACNTRL0, RSTFIFO);
+	/* Enable REQ/ACK protocol. */
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | SPIOEN);
+
+	if (sc->sc_prevphase == PH_MSGOUT) {
+		if (sc->sc_omp == sc->sc_omess) {
+			/*
+			 * This is a retransmission.
+			 *
+			 * We get here if the target stayed in MESSAGE OUT
+			 * phase.  Section 5.1.9.2 of the SCSI 2 spec indicates
+			 * that all of the previously transmitted messages must
+			 * be sent again, in the same order.  Therefore, we
+			 * requeue all the previously transmitted messages, and
+			 * start again from the top.  Our simple priority
+			 * scheme keeps the messages in the right order.
+			 */
+			AIC_MISC(("retransmitting  "));
+			sc->sc_msgpriq |= sc->sc_msgoutq;
+			/*
+			 * Set ATN.  If we're just sending a trivial 1-byte
+			 * message, we'll clear ATN later on anyway.
+			 */
+			bus_space_write_1(iot, ioh, SCSISIG, PH_MSGOUT | ATNO);
+		} else {
+			/* This is a continuation of the previous message. */
+			n = sc->sc_omp - sc->sc_omess;
+			goto nextbyte;
+		}
+	}
+
+	/* No messages transmitted so far. */
+	sc->sc_msgoutq = 0;
+	sc->sc_lastmsg = 0;
+
+nextmsg:
+	/* Pick up highest priority message. */
+	sc->sc_currmsg = sc->sc_msgpriq & -sc->sc_msgpriq;
+	sc->sc_msgpriq &= ~sc->sc_currmsg;
+	sc->sc_msgoutq |= sc->sc_currmsg;
+
+	/* Build the outgoing message data. */
+	switch (sc->sc_currmsg) {
+	case SEND_IDENTIFY:
+		AIC_ASSERT(sc->sc_nexus != NULL);
+		sc->sc_omess[0] =
+		    MSG_IDENTIFY(sc->sc_nexus->xs->sc_link->lun, 1);
+		n = 1;
+		break;
+
+#if AIC_USE_SYNCHRONOUS
+	case SEND_SDTR:
+		AIC_ASSERT(sc->sc_nexus != NULL);
+		ti = &sc->sc_tinfo[sc->sc_nexus->xs->sc_link->target];
+		sc->sc_omess[4] = MSG_EXTENDED;
+		sc->sc_omess[3] = 3;
+		sc->sc_omess[2] = MSG_EXT_SDTR;
+		sc->sc_omess[1] = ti->period >> 2;
+		sc->sc_omess[0] = ti->offset;
+		n = 5;
+		break;
+#endif
+
+#if AIC_USE_WIDE
+	case SEND_WDTR:
+		AIC_ASSERT(sc->sc_nexus != NULL);
+		ti = &sc->sc_tinfo[sc->sc_nexus->xs->sc_link->target];
+		sc->sc_omess[3] = MSG_EXTENDED;
+		sc->sc_omess[2] = 2;
+		sc->sc_omess[1] = MSG_EXT_WDTR;
+		sc->sc_omess[0] = ti->width;
+		n = 4;
+		break;
+#endif
+
+	case SEND_DEV_RESET:
+		sc->sc_flags |= AIC_ABORTING;
+		sc->sc_omess[0] = MSG_BUS_DEV_RESET;
+		n = 1;
+		break;
+
+	case SEND_REJECT:
+		sc->sc_omess[0] = MSG_MESSAGE_REJECT;
+		n = 1;
+		break;
+
+	case SEND_PARITY_ERROR:
+		sc->sc_omess[0] = MSG_PARITY_ERROR;
+		n = 1;
+		break;
+
+	case SEND_INIT_DET_ERR:
+		sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
+		n = 1;
+		break;
+
+	case SEND_ABORT:
+		sc->sc_flags |= AIC_ABORTING;
+		sc->sc_omess[0] = MSG_ABORT;
+		n = 1;
+		break;
+
+	default:
+		printf("%s: unexpected MESSAGE OUT; sending NOOP\n",
+		    sc->sc_dev.dv_xname);
+		AIC_BREAK();
+		sc->sc_omess[0] = MSG_NOOP;
+		n = 1;
+		break;
+	}
+	sc->sc_omp = &sc->sc_omess[n];
+
+nextbyte:
+	/* Send message bytes. */
+	for (;;) {
+		for (;;) {
+			sstat1 = bus_space_read_1(iot, ioh, SSTAT1);
+			if ((sstat1 & (REQINIT | PHASECHG | BUSFREE)) != 0)
+				break;
+			/* Wait for REQINIT.  XXX Need timeout. */
+		}
+		if ((sstat1 & (PHASECHG | BUSFREE)) != 0) {
+			/*
+			 * Target left MESSAGE OUT, possibly to reject
+			 * our message.
+			 *
+			 * If this is the last message being sent, then we
+			 * deassert ATN, since either the target is going to
+			 * ignore this message, or it's going to ask for a
+			 * retransmission via MESSAGE PARITY ERROR (in which
+			 * case we reassert ATN anyway).
+			 */
+			if (sc->sc_msgpriq == 0)
+				bus_space_write_1(iot, ioh, CLRSINT1, CLRATNO);
+			goto out;
+		}
+
+		/* Clear ATN before last byte if this is the last message. */
+		if (n == 1 && sc->sc_msgpriq == 0)
+			bus_space_write_1(iot, ioh, CLRSINT1, CLRATNO);
+		/* Send message byte. */
+		bus_space_write_1(iot, ioh, SCSIDAT, *--sc->sc_omp);
+		--n;
+		/* Keep track of the last message we've sent any bytes of. */
+		sc->sc_lastmsg = sc->sc_currmsg;
+		/* Wait for ACK to be negated.  XXX Need timeout. */
+		while ((bus_space_read_1(iot, ioh, SCSISIG) & ACKI) != 0)
+			;
+
+		if (n == 0)
+			break;
+	}
+
+	/* We get here only if the entire message has been transmitted. */
+	if (sc->sc_msgpriq != 0) {
+		/* There are more outgoing messages. */
+		goto nextmsg;
+	}
+
+	/*
+	 * The last message has been transmitted.  We need to remember the last
+	 * message transmitted (in case the target switches to MESSAGE IN phase
+	 * and sends a MESSAGE REJECT), and the list of messages transmitted
+	 * this time around (in case the target stays in MESSAGE OUT phase to
+	 * request a retransmit).
+	 */
+
+out:
+	/* Disable REQ/ACK protocol. */
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+}
+
+/* aic_dataout_pio: perform a data transfer using the FIFO datapath in the aic6360
+ * Precondition: The SCSI bus should be in the DOUT phase, with REQ asserted
+ * and ACK deasserted (i.e. waiting for a data byte).
+ * This new revision has been optimized (I tried) to make the common case fast,
+ * and the rarer cases (as a result) somewhat more complex.
+ */
+int
+aic_dataout_pio(struct aic_softc *sc, u_char *p, int n)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	u_char dmastat = 0;
+	int out = 0;
+#define DOUTAMOUNT 128		/* Full FIFO */
+
+	AIC_MISC(("%02x%02x  ", bus_space_read_1(iot, ioh, FIFOSTAT),
+	    bus_space_read_1(iot, ioh, SSTAT2)));
+
+	/* Clear host FIFO and counter. */
+	bus_space_write_1(iot, ioh, DMACNTRL0, RSTFIFO | WRITE);
+	/* Enable FIFOs. */
+	bus_space_write_1(iot, ioh, DMACNTRL0, ENDMA | DWORDPIO | WRITE);
+	bus_space_write_1(iot, ioh, SXFRCTL0, SCSIEN | DMAEN | CHEN);
+
+	/* Turn off ENREQINIT for now. */
+	bus_space_write_1(iot, ioh, SIMODE1,
+	    ENSCSIRST | ENSCSIPERR | ENBUSFREE | ENPHASECHG);
+
+	/* I have tried to make the main loop as tight as possible.  This
+	 * means that some of the code following the loop is a bit more
+	 * complex than otherwise.
+	 */
+	while (n > 0) {
+		for (;;) {
+			dmastat = bus_space_read_1(iot, ioh, DMASTAT);
+			if ((dmastat & (DFIFOEMP | INTSTAT)) != 0)
+				break;
+		}
+
+		if ((dmastat & INTSTAT) != 0)
+			goto phasechange;
+
+		if (n >= DOUTAMOUNT) {
+			n -= DOUTAMOUNT;
+			out += DOUTAMOUNT;
+
+#if AIC_USE_DWORDS
+			bus_space_write_multi_4(iot, ioh, DMADATALONG,
+			    (u_int32_t *)p, DOUTAMOUNT >> 2);
+#else
+			bus_space_write_multi_2(iot, ioh, DMADATA,
+			    (u_int16_t *)p, DOUTAMOUNT >> 1);
+#endif
+
+			p += DOUTAMOUNT;
+		} else {
+			int xfer;
+
+			xfer = n;
+			AIC_MISC(("%d> ", xfer));
+
+			n -= xfer;
+			out += xfer;
+
+#if AIC_USE_DWORDS
+			if (xfer >= 12) {
+				bus_space_write_multi_4(iot, ioh, DMADATALONG,
+				    (u_int32_t *)p, xfer >> 2);
+				p += xfer & ~3;
+				xfer &= 3;
+			}
+#else
+			if (xfer >= 8) {
+				bus_space_write_multi_2(iot, ioh,  DMADATA,
+				    (u_int16_t *)p, xfer >> 1);
+				p += xfer & ~1;
+				xfer &= 1;
+			}
+#endif
+
+			if (xfer > 0) {
+				bus_space_write_1(iot, ioh, DMACNTRL0,
+				    ENDMA | B8MODE | WRITE);
+				bus_space_write_multi_1(iot, ioh,  DMADATA, p,
+				    xfer);
+				p += xfer;
+				bus_space_write_1(iot, ioh, DMACNTRL0,
+				    ENDMA | DWORDPIO | WRITE);
+			}
+		}
+	}
+
+	if (out == 0) {
+		bus_space_write_1(iot, ioh, SXFRCTL1, BITBUCKET);
+		for (;;) {
+			if ((bus_space_read_1(iot, ioh, DMASTAT) & INTSTAT) !=
+			    0)
+				break;
+		}
+		bus_space_write_1(iot, ioh, SXFRCTL1, 0);
+		AIC_MISC(("extra data  "));
+	} else {
+		/* See the bytes off chip */
+		for (;;) {
+			dmastat = bus_space_read_1(iot, ioh, DMASTAT);
+			if ((dmastat & INTSTAT) != 0)
+				goto phasechange;
+			if ((dmastat & DFIFOEMP) != 0 &&
+			    (bus_space_read_1(iot, ioh, SSTAT2) & SEMPTY) != 0)
+				break;
+		}
+	}
+
+phasechange:
+	if ((dmastat & INTSTAT) != 0) {
+		/* Some sort of phase change. */
+		int amount;
+
+		/* Stop transfers, do some accounting */
+		amount = bus_space_read_1(iot, ioh, FIFOSTAT) +
+		    (bus_space_read_1(iot, ioh, SSTAT2) & 15);
+		if (amount > 0) {
+			out -= amount;
+			bus_space_write_1(iot, ioh, DMACNTRL0,
+			    RSTFIFO | WRITE);
+			bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | CLRCH);
+			AIC_MISC(("+%d ", amount));
+		}
+	}
+
+	/* Turn on ENREQINIT again. */
+	bus_space_write_1(iot, ioh, SIMODE1,
+	    ENSCSIRST | ENSCSIPERR | ENBUSFREE | ENREQINIT | ENPHASECHG);
+
+	/* Stop the FIFO data path. */
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+	bus_space_write_1(iot, ioh, DMACNTRL0, 0);
+
+	return out;
+}
+
+/* aic_datain_pio: perform data transfers using the FIFO datapath in the aic6360
+ * Precondition: The SCSI bus should be in the DIN phase, with REQ asserted
+ * and ACK deasserted (i.e. at least one byte is ready).
+ * For now, uses a pretty dumb algorithm, hangs around until all data has been
+ * transferred.  This, is OK for fast targets, but not so smart for slow
+ * targets which don't disconnect or for huge transfers.
+ */
+int
+aic_datain_pio(struct aic_softc *sc, u_char *p, int n)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	u_char dmastat;
+	int in = 0;
+#define DINAMOUNT 128		/* Full FIFO */
+
+	AIC_MISC(("%02x%02x  ", bus_space_read_1(iot, ioh, FIFOSTAT),
+	    bus_space_read_1(iot, ioh, SSTAT2)));
+
+	/* Clear host FIFO and counter. */
+	bus_space_write_1(iot, ioh, DMACNTRL0, RSTFIFO);
+	/* Enable FIFOs. */
+	bus_space_write_1(iot, ioh, DMACNTRL0, ENDMA | DWORDPIO);
+	bus_space_write_1(iot, ioh, SXFRCTL0, SCSIEN | DMAEN | CHEN);
+
+	/* Turn off ENREQINIT for now. */
+	bus_space_write_1(iot, ioh, SIMODE1,
+	    ENSCSIRST | ENSCSIPERR | ENBUSFREE | ENPHASECHG);
+
+	/* We leave this loop if one or more of the following is true:
+	 * a) phase != PH_DATAIN && FIFOs are empty
+	 * b) SCSIRSTI is set (a reset has occurred) or busfree is detected.
+	 */
+	while (n > 0) {
+		/* Wait for fifo half full or phase mismatch */
+		for (;;) {
+			dmastat = bus_space_read_1(iot, ioh, DMASTAT);
+			if ((dmastat & (DFIFOFULL | INTSTAT)) != 0)
+				break;
+		}
+
+		if ((dmastat & DFIFOFULL) != 0) {
+			n -= DINAMOUNT;
+			in += DINAMOUNT;
+
+#if AIC_USE_DWORDS
+			bus_space_read_multi_4(iot, ioh, DMADATALONG,
+			    (u_int32_t *)p, DINAMOUNT >> 2);
+#else
+			bus_space_read_multi_2(iot, ioh, DMADATA,
+			    (u_int16_t *)p, DINAMOUNT >> 1);
+#endif
+
+			p += DINAMOUNT;
+		} else {
+			int xfer;
+
+			xfer = min(bus_space_read_1(iot, ioh, FIFOSTAT), n);
+			AIC_MISC((">%d ", xfer));
+
+			n -= xfer;
+			in += xfer;
+
+#if AIC_USE_DWORDS
+			if (xfer >= 12) {
+				bus_space_read_multi_4(iot, ioh, DMADATALONG,
+				    (u_int32_t *)p, xfer >> 2);
+				p += xfer & ~3;
+				xfer &= 3;
+			}
+#else
+			if (xfer >= 8) {
+				bus_space_read_multi_2(iot, ioh, DMADATA,
+				    (u_int16_t *)p, xfer >> 1);
+				p += xfer & ~1;
+				xfer &= 1;
+			}
+#endif
+
+			if (xfer > 0) {
+				bus_space_write_1(iot, ioh, DMACNTRL0,
+				    ENDMA | B8MODE);
+				bus_space_read_multi_1(iot, ioh, DMADATA, p,
+				    xfer);
+				p += xfer;
+				bus_space_write_1(iot, ioh, DMACNTRL0,
+				    ENDMA | DWORDPIO);
+			}
+		}
+
+		if ((dmastat & INTSTAT) != 0)
+			goto phasechange;
+	}
+
+	/* Some SCSI-devices are rude enough to transfer more data than what
+	 * was requested, e.g. 2048 bytes from a CD-ROM instead of the
+	 * requested 512.  Test for progress, i.e. real transfers.  If no real
+	 * transfers have been performed (n is probably already zero) and the
+	 * FIFO is not empty, waste some bytes....
+	 */
+	if (in == 0) {
+		bus_space_write_1(iot, ioh, SXFRCTL1, BITBUCKET);
+		for (;;) {
+			if ((bus_space_read_1(iot, ioh, DMASTAT) & INTSTAT) !=
+			    0)
+				break;
+		}
+		bus_space_write_1(iot, ioh, SXFRCTL1, 0);
+		AIC_MISC(("extra data  "));
+	}
+
+phasechange:
+	/* Turn on ENREQINIT again. */
+	bus_space_write_1(iot, ioh, SIMODE1,
+	    ENSCSIRST | ENSCSIPERR | ENBUSFREE | ENREQINIT | ENPHASECHG);
+
+	/* Stop the FIFO data path. */
+	bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+	bus_space_write_1(iot, ioh, DMACNTRL0, 0);
+
+	return in;
+}
+
+/*
+ * This is the workhorse routine of the driver.
+ * Deficiencies (for now):
+ * 1) always uses programmed I/O
+ */
+int
+aicintr(void *arg)
+{
+	struct aic_softc *sc = arg;
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+	u_char sstat0, sstat1;
+	struct aic_acb *acb;
+	struct scsi_link *sc_link;
+	struct aic_tinfo *ti;
+	int n;
+
+	/*
+	 * Clear INTEN.  We enable it again before returning.  This makes the
+	 * interrupt esssentially level-triggered.
+	 */
+	bus_space_write_1(iot, ioh, DMACNTRL0, 0);
+
+	AIC_TRACE(("aicintr  "));
+
+loop:
+	/*
+	 * First check for abnormal conditions, such as reset.
+	 */
+	sstat1 = bus_space_read_1(iot, ioh, SSTAT1);
+	AIC_MISC(("sstat1:0x%02x ", sstat1));
+
+	if ((sstat1 & SCSIRSTI) != 0) {
+		printf("%s: SCSI bus reset\n", sc->sc_dev.dv_xname);
+		goto reset;
+	}
+
+	/*
+	 * Check for less serious errors.
+	 */
+	if ((sstat1 & SCSIPERR) != 0) {
+		printf("%s: SCSI bus parity error\n", sc->sc_dev.dv_xname);
+		bus_space_write_1(iot, ioh, CLRSINT1, CLRSCSIPERR);
+		if (sc->sc_prevphase == PH_MSGIN) {
+			sc->sc_flags |= AIC_DROP_MSGIN;
+			aic_sched_msgout(sc, SEND_PARITY_ERROR);
+		} else
+			aic_sched_msgout(sc, SEND_INIT_DET_ERR);
+	}
+
+	/*
+	 * If we're not already busy doing something test for the following
+	 * conditions:
+	 * 1) We have been reselected by something
+	 * 2) We have selected something successfully
+	 * 3) Our selection process has timed out
+	 * 4) This is really a bus free interrupt just to get a new command
+	 *    going?
+	 * 5) Spurious interrupt?
+	 */
+	switch (sc->sc_state) {
+	case AIC_IDLE:
+	case AIC_SELECTING:
+		sstat0 = bus_space_read_1(iot, ioh, SSTAT0);
+		AIC_MISC(("sstat0:0x%02x ", sstat0));
+
+		if ((sstat0 & TARGET) != 0) {
+			/*
+			 * We don't currently support target mode.
+			 */
+			printf("%s: target mode selected; going to BUS FREE\n",
+			    sc->sc_dev.dv_xname);
+			bus_space_write_1(iot, ioh, SCSISIG, 0);
+
+			goto sched;
+		} else if ((sstat0 & SELDI) != 0) {
+			AIC_MISC(("reselected  "));
+
+			/*
+			 * If we're trying to select a target ourselves,
+			 * push our command back into the ready list.
+			 */
+			if (sc->sc_state == AIC_SELECTING) {
+				AIC_MISC(("backoff selector  "));
+				AIC_ASSERT(sc->sc_nexus != NULL);
+				acb = sc->sc_nexus;
+				sc->sc_nexus = NULL;
+				TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
+			}
+
+			/* Save reselection ID. */
+			sc->sc_selid = bus_space_read_1(iot, ioh, SELID);
+
+			sc->sc_state = AIC_RESELECTED;
+		} else if ((sstat0 & SELDO) != 0) {
+			AIC_MISC(("selected  "));
+
+			/* We have selected a target. Things to do:
+			 * a) Determine what message(s) to send.
+			 * b) Verify that we're still selecting the target.
+			 * c) Mark device as busy.
+			 */
+			if (sc->sc_state != AIC_SELECTING) {
+				printf("%s: selection out while idle; ",
+				    sc->sc_dev.dv_xname);
+				printf("resetting\n");
+				AIC_BREAK();
+				goto reset;
+			}
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+			sc_link = acb->xs->sc_link;
+			ti = &sc->sc_tinfo[sc_link->target];
+
+			sc->sc_msgpriq = SEND_IDENTIFY;
+			if (acb->flags & ACB_RESET)
+				sc->sc_msgpriq |= SEND_DEV_RESET;
+			else if (acb->flags & ACB_ABORT)
+				sc->sc_msgpriq |= SEND_ABORT;
+			else {
+#if AIC_USE_SYNCHRONOUS
+				if ((ti->flags & DO_SYNC) != 0)
+					sc->sc_msgpriq |= SEND_SDTR;
+#endif
+#if AIC_USE_WIDE
+				if ((ti->flags & DO_WIDE) != 0)
+					sc->sc_msgpriq |= SEND_WDTR;
+#endif
+			}
+
+			acb->flags |= ACB_NEXUS;
+			ti->lubusy |= (1 << sc_link->lun);
+
+			/* Do an implicit RESTORE POINTERS. */
+			sc->sc_dp = acb->data_addr;
+			sc->sc_dleft = acb->data_length;
+			sc->sc_cp = (u_char *)&acb->scsi_cmd;
+			sc->sc_cleft = acb->scsi_cmd_length;
+
+			/* On our first connection, schedule a timeout. */
+			if ((acb->xs->flags & SCSI_POLL) == 0)
+				timeout_add_msec(&acb->xs->stimeout, acb->timeout);
+
+			sc->sc_state = AIC_CONNECTED;
+		} else if ((sstat1 & SELTO) != 0) {
+			AIC_MISC(("selection timeout  "));
+
+			if (sc->sc_state != AIC_SELECTING) {
+				printf("%s: selection timeout while idle; ",
+				    sc->sc_dev.dv_xname);
+				printf("resetting\n");
+				AIC_BREAK();
+				goto reset;
+			}
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+
+			bus_space_write_1(iot, ioh, SXFRCTL1, 0);
+			bus_space_write_1(iot, ioh, SCSISEQ, ENRESELI);
+			bus_space_write_1(iot, ioh, CLRSINT1, CLRSELTIMO);
+			delay(250);
+
+			acb->xs->error = XS_SELTIMEOUT;
+			goto finish;
+		} else {
+			if (sc->sc_state != AIC_IDLE) {
+				printf("%s: BUS FREE while not idle; ",
+				    sc->sc_dev.dv_xname);
+				printf("state=%d\n", sc->sc_state);
+				AIC_BREAK();
+				goto out;
+			}
+
+			goto sched;
+		}
+
+		/*
+		 * Turn off selection stuff, and prepare to catch bus free
+		 * interrupts, parity errors, and phase changes.
+		 */
+		bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | CLRSTCNT | CLRCH);
+		bus_space_write_1(iot, ioh, SXFRCTL1, 0);
+		bus_space_write_1(iot, ioh, SCSISEQ, ENAUTOATNP);
+		bus_space_write_1(iot, ioh, CLRSINT0, CLRSELDI | CLRSELDO);
+		bus_space_write_1(iot, ioh, CLRSINT1,
+		    CLRBUSFREE | CLRPHASECHG);
+		bus_space_write_1(iot, ioh, SIMODE0, 0);
+		bus_space_write_1(iot, ioh, SIMODE1,
+		    ENSCSIRST | ENSCSIPERR | ENBUSFREE | ENREQINIT |
+		    ENPHASECHG);
+
+		sc->sc_flags = 0;
+		sc->sc_prevphase = PH_INVALID;
+		goto dophase;
+	}
+
+	if ((sstat1 & BUSFREE) != 0) {
+		/* We've gone to BUS FREE phase. */
+		bus_space_write_1(iot, ioh, CLRSINT1,
+		    CLRBUSFREE | CLRPHASECHG);
+
+		switch (sc->sc_state) {
+		case AIC_RESELECTED:
+			goto sched;
+
+		case AIC_CONNECTED:
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+
+#if AIC_USE_SYNCHRONOUS + AIC_USE_WIDE
+			if (sc->sc_prevphase == PH_MSGOUT) {
+				/*
+				 * If the target went to BUS FREE phase during
+				 * or immediately after sending a SDTR or WDTR
+				 * message, disable negotiation.
+				 */
+				sc_link = acb->xs->sc_link;
+				ti = &sc->sc_tinfo[sc_link->target];
+				switch (sc->sc_lastmsg) {
+#if AIC_USE_SYNCHRONOUS
+				case SEND_SDTR:
+					ti->flags &= ~DO_SYNC;
+					ti->period = ti->offset = 0;
+					break;
+#endif
+#if AIC_USE_WIDE
+				case SEND_WDTR:
+					ti->flags &= ~DO_WIDE;
+					ti->width = 0;
+					break;
+#endif
+				}
+			}
+#endif
+
+			if ((sc->sc_flags & AIC_ABORTING) == 0) {
+				/*
+				 * Section 5.1.1 of the SCSI 2 spec suggests
+				 * issuing a REQUEST SENSE following an
+				 * unexpected disconnect.  Some devices go into
+				 * a contingent allegiance condition when
+				 * disconnecting, and this is necessary to
+				 * clean up their state.
+				 */
+				printf("%s: unexpected disconnect; ",
+				    sc->sc_dev.dv_xname);
+				printf("sending REQUEST SENSE\n");
+				AIC_BREAK();
+				aic_sense(sc, acb);
+				goto out;
+			}
+
+			acb->xs->error = XS_DRIVER_STUFFUP;
+			goto finish;
+
+		case AIC_DISCONNECT:
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+#if 1 /* XXXX */
+			acb->data_addr = sc->sc_dp;
+			acb->data_length = sc->sc_dleft;
+#endif
+			TAILQ_INSERT_HEAD(&sc->nexus_list, acb, chain);
+			sc->sc_nexus = NULL;
+			goto sched;
+
+		case AIC_CMDCOMPLETE:
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+			goto finish;
+		}
+	}
+
+	bus_space_write_1(iot, ioh, CLRSINT1, CLRPHASECHG);
+
+dophase:
+	if ((sstat1 & REQINIT) == 0) {
+		/* Wait for REQINIT. */
+		goto out;
+	}
+
+	sc->sc_phase = bus_space_read_1(iot, ioh, SCSISIG) & PH_MASK;
+	bus_space_write_1(iot, ioh, SCSISIG, sc->sc_phase);
+
+	switch (sc->sc_phase) {
+	case PH_MSGOUT:
+		if (sc->sc_state != AIC_CONNECTED &&
+		    sc->sc_state != AIC_RESELECTED)
+			break;
+		aic_msgout(sc);
+		sc->sc_prevphase = PH_MSGOUT;
+		goto loop;
+
+	case PH_MSGIN:
+		if (sc->sc_state != AIC_CONNECTED &&
+		    sc->sc_state != AIC_RESELECTED)
+			break;
+		aic_msgin(sc);
+		sc->sc_prevphase = PH_MSGIN;
+		goto loop;
+
+	case PH_CMD:
+		if (sc->sc_state != AIC_CONNECTED)
+			break;
+#ifdef AIC_DEBUG
+		if ((aic_debug & AIC_SHOWMISC) != 0) {
+			AIC_ASSERT(sc->sc_nexus != NULL);
+			acb = sc->sc_nexus;
+			printf("cmd=0x%02x+%d ",
+			    acb->scsi_cmd.opcode, acb->scsi_cmd_length-1);
+		}
+#endif
+		n = aic_dataout_pio(sc, sc->sc_cp, sc->sc_cleft);
+		sc->sc_cp += n;
+		sc->sc_cleft -= n;
+		sc->sc_prevphase = PH_CMD;
+		goto loop;
+
+	case PH_DATAOUT:
+		if (sc->sc_state != AIC_CONNECTED)
+			break;
+		AIC_MISC(("dataout dleft=%lu ", (u_long)sc->sc_dleft));
+		n = aic_dataout_pio(sc, sc->sc_dp, sc->sc_dleft);
+		sc->sc_dp += n;
+		sc->sc_dleft -= n;
+		sc->sc_prevphase = PH_DATAOUT;
+		goto loop;
+
+	case PH_DATAIN:
+		if (sc->sc_state != AIC_CONNECTED)
+			break;
+		AIC_MISC(("datain %lu ", (u_long)sc->sc_dleft));
+		n = aic_datain_pio(sc, sc->sc_dp, sc->sc_dleft);
+		sc->sc_dp += n;
+		sc->sc_dleft -= n;
+		sc->sc_prevphase = PH_DATAIN;
+		goto loop;
+
+	case PH_STAT:
+		if (sc->sc_state != AIC_CONNECTED)
+			break;
+		AIC_ASSERT(sc->sc_nexus != NULL);
+		acb = sc->sc_nexus;
+		bus_space_write_1(iot, ioh, SXFRCTL0, CHEN | SPIOEN);
+		acb->target_stat = bus_space_read_1(iot, ioh, SCSIDAT);
+		bus_space_write_1(iot, ioh, SXFRCTL0, CHEN);
+		AIC_MISC(("target_stat=0x%02x ", acb->target_stat));
+		sc->sc_prevphase = PH_STAT;
+		goto loop;
+	}
+
+	printf("%s: unexpected bus phase; resetting\n", sc->sc_dev.dv_xname);
+	AIC_BREAK();
+reset:
+	aic_init(sc);
+	return 1;
+
+finish:
+	timeout_del(&acb->xs->stimeout);
+	aic_done(sc, acb);
+	goto out;
+
+sched:
+	sc->sc_state = AIC_IDLE;
+	aic_sched(sc);
+	goto out;
+
+out:
+	bus_space_write_1(iot, ioh, DMACNTRL0, INTEN);
+	return 1;
+}
+
+void
+aic_abort(struct aic_softc *sc, struct aic_acb *acb)
+{
+
+	/* 2 secs for the abort */
+	acb->timeout = AIC_ABORT_TIMEOUT;
+	acb->flags |= ACB_ABORT;
+
+	if (acb == sc->sc_nexus) {
+		/*
+		 * If we're still selecting, the message will be scheduled
+		 * after selection is complete.
+		 */
+		if (sc->sc_state == AIC_CONNECTED)
+			aic_sched_msgout(sc, SEND_ABORT);
+	} else {
+		aic_dequeue(sc, acb);
+		TAILQ_INSERT_HEAD(&sc->ready_list, acb, chain);
+		if (sc->sc_state == AIC_IDLE)
+			aic_sched(sc);
+	}
+}
+
+void
+aic_timeout(void *arg)
+{
+	struct aic_acb *acb = arg;
+	struct scsi_xfer *xs = acb->xs;
+	struct scsi_link *sc_link = xs->sc_link;
+	struct aic_softc *sc = sc_link->bus->sb_adapter_softc;
+	int s;
+
+	sc_print_addr(sc_link);
+	printf("timed out");
+
+	s = splbio();
+
+	if (acb->flags & ACB_ABORT) {
+		/* abort timed out */
+		printf(" AGAIN\n");
+		/* XXX Must reset! */
+	} else {
+		/* abort the operation that has timed out */
+		printf("\n");
+		acb->xs->error = XS_TIMEOUT;
+		aic_abort(sc, acb);
+	}
+
+	splx(s);
+}
+
+#ifdef AIC_DEBUG
+/*
+ * The following functions are mostly used for debugging purposes, either
+ * directly called from the driver or from the kernel debugger.
+ */
+
+void
+aic_show_scsi_cmd(struct aic_acb *acb)
+{
+	u_char  *b = (u_char *)&acb->scsi_cmd;
+	struct scsi_link *sc_link = acb->xs->sc_link;
+	int i;
+
+	sc_print_addr(sc_link);
+	if ((acb->xs->flags & SCSI_RESET) == 0) {
+		for (i = 0; i < acb->scsi_cmd_length; i++) {
+			if (i)
+				printf(",");
+			printf("%x", b[i]);
+		}
+		printf("\n");
+	} else
+		printf("RESET\n");
+}
+
+void
+aic_print_acb(struct aic_acb *acb)
+{
+
+	printf("acb@%p xs=%p flags=%x", acb, acb->xs, acb->flags);
+	printf(" dp=%p dleft=%d target_stat=%x\n",
+	       acb->data_addr, acb->data_length, acb->target_stat);
+	aic_show_scsi_cmd(acb);
+}
+
+void
+aic_print_active_acb(void)
+{
+	struct aic_acb *acb;
+	struct aic_softc *sc = aic_cd.cd_devs[0];
+
+	printf("ready list:\n");
+	TAILQ_FOREACH(acb, &sc->ready_list, chain)
+		aic_print_acb(acb);
+	printf("nexus:\n");
+	if (sc->sc_nexus != NULL)
+		aic_print_acb(sc->sc_nexus);
+	printf("nexus list:\n");
+	TAILQ_FOREACH(acb, &sc->nexus_list, chain)
+		aic_print_acb(acb);
+}
+
+void
+aic_dump6360(struct aic_softc *sc)
+{
+	bus_space_tag_t iot = sc->sc_iot;
+	bus_space_handle_t ioh = sc->sc_ioh;
+
+	printf("aic6360: SCSISEQ=%x SXFRCTL0=%x SXFRCTL1=%x SCSISIG=%x\n",
+	    bus_space_read_1(iot, ioh, SCSISEQ),
+	    bus_space_read_1(iot, ioh, SXFRCTL0),
+	    bus_space_read_1(iot, ioh, SXFRCTL1),
+	    bus_space_read_1(iot, ioh, SCSISIG));
+	printf("         SSTAT0=%x SSTAT1=%x SSTAT2=%x SSTAT3=%x SSTAT4=%x\n",
+	    bus_space_read_1(iot, ioh, SSTAT0),
+	    bus_space_read_1(iot, ioh, SSTAT1),
+	    bus_space_read_1(iot, ioh, SSTAT2),
+	    bus_space_read_1(iot, ioh, SSTAT3),
+	    bus_space_read_1(iot, ioh, SSTAT4));
+	printf("         SIMODE0=%x SIMODE1=%x ",
+	    bus_space_read_1(iot, ioh, SIMODE0),
+	    bus_space_read_1(iot, ioh, SIMODE1));
+	printf("DMACNTRL0=%x DMACNTRL1=%x DMASTAT=%x\n",
+	    bus_space_read_1(iot, ioh, DMACNTRL0),
+	    bus_space_read_1(iot, ioh, DMACNTRL1),
+	    bus_space_read_1(iot, ioh, DMASTAT));
+	printf("         FIFOSTAT=%d SCSIBUS=0x%x\n",
+	    bus_space_read_1(iot, ioh, FIFOSTAT),
+	    bus_space_read_1(iot, ioh, SCSIBUS));
+}
+
+void
+aic_dump_driver(struct aic_softc *sc)
+{
+	struct aic_tinfo *ti;
+	int i;
+
+	printf("nexus=%p prevphase=%x\n", sc->sc_nexus, sc->sc_prevphase);
+	printf("state=%x msgin=%x ", sc->sc_state, sc->sc_imess[0]);
+	printf("msgpriq=%x msgoutq=%x lastmsg=%x currmsg=%x\n", sc->sc_msgpriq,
+	    sc->sc_msgoutq, sc->sc_lastmsg, sc->sc_currmsg);
+	for (i = 0; i < 7; i++) {
+		ti = &sc->sc_tinfo[i];
+		printf("tinfo%d: %d cmds %d disconnects %d timeouts",
+		    i, ti->cmds, ti->dconns, ti->touts);
+		printf(" %d senses flags=%x\n", ti->senses, ti->flags);
+	}
+}
+#endif
Index: sys/arch/luna88k/cbus/aic_cbus.c
===================================================================
RCS file: sys/arch/luna88k/cbus/aic_cbus.c
diff -N sys/arch/luna88k/cbus/aic_cbus.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ sys/arch/luna88k/cbus/aic_cbus.c	17 Aug 2020 11:55:33 -0000
@@ -0,0 +1,185 @@
+/*	$OpenBSD: aic_isa.c,v 1.8 2017/09/08 05:36:52 deraadt Exp $	*/
+/*	$NetBSD: aic6360.c,v 1.52 1996/12/10 21:27:51 thorpej Exp $	*/
+
+/*
+ * Copyright (c) 1994, 1995, 1996 Charles Hannum.  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 Charles M. Hannum.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Copyright (c) 1994 Jarle Greipsland
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ */
+
+/*
+ * Acknowledgements: Many of the algorithms used in this driver are
+ * inspired by the work of Julian Elischer ([email protected]) and
+ * Charles Hannum ([email protected]).  Thanks a million!
+ */
+
+/*
+ * Driver for NEC PC-9801-100 (a.k.a Adaptec AHA-1030P)
+ *  based on OpenBSD:src/sys/dev/isa/aic_isa.c
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/device.h>
+#include <sys/buf.h>
+#include <sys/queue.h>
+
+#include <machine/board.h>	/* PC_BASE */
+#include <machine/bus.h>
+#include <machine/intr.h>
+
+#include <scsi/scsi_all.h>
+#include <scsi/scsi_message.h>
+#include <scsi/scsiconf.h>
+
+#include <arch/luna88k/cbus/cbusvar.h>
+
+#include <dev/ic/aic6360reg.h>
+#include <dev/ic/aic6360var.h>
+
+#define	PCEXIO_BASE	PC_BASE + 0x1000000
+#if 0
+#define	AIC_CBUS_INT	1	/* default, IRQ=5 */
+#define	AIC_CBUS_IOBASE	0x1840	/* default */
+#endif
+
+struct luna88k_bus_space_tag aic_cbus_io_bst = {
+	.bs_stride_1 = 1,
+	.bs_stride_2 = 1,
+	.bs_stride_4 = 1,
+	.bs_stride_8 = 0,	/* not used */
+	.bs_offset = PCEXIO_BASE,
+#if 0
+	.bs_flags = TAG_LITTLE_ENDIAN
+#else
+	.bs_flags = 0
+#endif
+};
+
+int	aic_cbus_probe(struct device *, void *, void *);
+void	aic_cbus_attach(struct device *, struct device *, void *);
+
+struct cfattach aic_cbus_ca = {
+	sizeof(struct aic_softc), aic_cbus_probe, aic_cbus_attach
+};
+
+/*
+ * INITIALIZATION ROUTINES (probe, attach ++)
+ */
+
+/*
+ * aicprobe: probe for AIC6360 SCSI-controller
+ * returns non-zero value if a controller is found.
+ */
+int
+aic_cbus_probe(parent, match, aux)
+	struct device *parent;
+	void *match, *aux;
+{
+	struct cfdata *cf = match;
+	struct cbus_attach_args *caa = aux;
+	bus_space_tag_t iot = &aic_cbus_io_bst;
+	bus_space_handle_t ioh;
+	int rv;
+
+	if (strcmp(caa->ca_name, cf->cf_driver->cd_name) != 0)
+		return (0);
+
+	caa->ca_iobase = cf->cf_iobase;
+	caa->ca_int    = cf->cf_int;
+
+        /* Disallow wildcarded values. */
+        if (caa->ca_int ==  -1)
+                return (0);
+        if (caa->ca_iobase == -1)
+                return (0);
+
+	if (bus_space_map(iot, caa->ca_iobase, AIC_NPORTS, 0, &ioh))
+		return (0);
+
+	AIC_TRACE(("aic: probing for aic-chip at port 0x%x\n",
+		caa->ca_iobase));
+
+	rv = aic_find(iot, ioh);
+
+	bus_space_unmap(iot, ioh, AIC_NPORTS);
+
+	if (rv) {
+		caa->ca_msize = 0;
+		caa->ca_iosize = AIC_NPORTS;
+	}
+	return (rv);
+}
+
+/*
+ * Attach the AIC6360, fill out some high and low level data structures
+ */
+void
+aic_cbus_attach(parent, self, aux)
+	struct device *parent, *self;
+	void *aux;
+{
+	struct cbus_attach_args *caa = aux;
+	bus_space_tag_t iot = &aic_cbus_io_bst;
+	bus_space_handle_t ioh;
+	struct aic_softc *sc = (void *)self;
+
+	if (bus_space_map(iot, caa->ca_iobase, AIC_NPORTS, 0, &ioh))
+		panic("%s: can't map i/o-ports", sc->sc_dev.dv_xname);
+
+	sc->sc_iot = iot;
+	sc->sc_ioh = ioh;
+
+	printf("\n");
+
+#if 0
+	sc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq, IST_EDGE,
+	    IPL_BIO, aicintr, sc, sc->sc_dev.dv_xname);
+#else
+	cbus_isrlink(aicintr, sc, caa->ca_int, IPL_BIO, sc->sc_dev.dv_xname);
+#endif
+
+	aicattach(sc);
+}
+
Index: sys/arch/luna88k/cbus/cbus.c
===================================================================
RCS file: /cvs/src/sys/arch/luna88k/cbus/cbus.c,v
retrieving revision 1.8
diff -u -r1.8 cbus.c
--- sys/arch/luna88k/cbus/cbus.c	30 Dec 2019 12:16:12 -0000	1.8
+++ sys/arch/luna88k/cbus/cbus.c	17 Aug 2020 11:55:33 -0000
@@ -36,11 +36,16 @@
 #define CBUS_DEBUG
 #endif
 
+#include "aic.h"
 #include "ne.h"
 #include "necsb.h"
 #include "pcic.h"
 
 static struct cbus_attach_args cbus_devs[] = {
+#if NAIC > 0
+	/* PC-9801-100 SCSI-2 interface board */
+	{ "aic",   -1, -1, -1, -1, -1 },
+#endif
 #if NNE > 0
 	/* NE-2000 compatible ethernet */
 	{ "ne",    -1, -1, -1, -1, -1 },
Index: sys/arch/luna88k/conf/CBUS.MP
===================================================================
RCS file: sys/arch/luna88k/conf/CBUS.MP
diff -N sys/arch/luna88k/conf/CBUS.MP
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ sys/arch/luna88k/conf/CBUS.MP	17 Aug 2020 11:55:33 -0000
@@ -0,0 +1,103 @@
+#	$OpenBSD: GENERIC,v 1.24 2019/12/30 12:16:12 aoyama Exp $
+#
+# For further information on compiling OpenBSD kernels, see the config(8)
+# man page.
+#
+# For further information on hardware support for this architecture, see
+# the intro(4) man page.  For further information about kernel options
+# for this architecture, see the options(4) man page.  For an explanation
+# of each device driver in this file see the section 4 man page for the
+# device.
+
+machine		luna88k m88k
+include		"../../../conf/GENERIC"
+maxusers	64			# estimated number of users
+
+# Processor type
+option		M88100		# 88100 support; mandatory
+
+# Number of maximum processors
+option		MAX_CPUS=4	# may have up to 4 processors 
+
+# Define this if your processor has the xxx.usr bug (mask C82N)
+option		ERRATA__XXX_USR
+
+# Options for luna88k hardware
+option		WSDISPLAY_COMPAT_RAWKBD	# Provide raw scancodes; needed for X11
+
+config		bsd		swap generic
+
+#
+# devices
+#
+
+mainbus0	at root
+clock0		at mainbus0
+lcd0		at mainbus0
+le0		at mainbus0
+sio0		at mainbus0
+siotty0		at sio0
+ws0		at sio0
+fb0		at mainbus0
+spc0		at mainbus0
+spc1		at mainbus0
+
+# Workstation Console attachments
+wsdisplay*	at fb?
+wskbd*		at ws? mux 1
+wsmouse*	at ws? mux 0
+
+# HD647180X I/O processor
+xp0		at mainbus0
+
+# PC-9801 extension board slot
+cbus0		at mainbus0
+
+# PC-9801 extension board slot 'generic' driver
+pcex0		at cbus0
+
+# NE2000 ethernet
+#ne0		at cbus0 port 0xc8d0 int 0	# CentreCOM LA-98
+
+# NEC PC-9801-86 sound board 
+#necsb*		at cbus?
+#audio*		at necsb?
+
+# NEC PC-9801-100 SCSI board
+aic0		at cbus? port 0x1840 int 1	# default value
+
+# NEC PC-9801-102 & PC-9821X[AE]-E01 PC Card slot adapter
+#pcic0		at cbus? port 0x3e0 iomem 0xd0000 iosiz 0x10000
+#pcmcia*	at pcic?
+
+# SCSI devices
+scsibus*	at scsi?
+sd*		at scsibus?
+st*		at scsibus?
+cd*		at scsibus?
+ch*		at scsibus?
+safte*		at scsibus?
+ses*		at scsibus?
+uk*		at scsibus?
+
+# Pseudo-device
+pseudo-device	wsmux 2
+
+# PCMCIA devices
+# XXX: malo(4) is not supported, because LUNA-88K does not have DMA.
+#com*		at pcmcia?		# PCMCIA modems/serial ports
+##aic*		at pcmcia?		# PCMCIA Adaptec 152[02] SCSI (not yet)
+#wdc*		at pcmcia?		# IDE controllers
+#ne*		at pcmcia?		# PCMCIA based NE2000 ethernet
+#ep*		at pcmcia?		# PCMCIA based 3C5xx ethernet
+#sm*		at pcmcia?		# PCMCIA based sm ethernet
+#xe*		at pcmcia?		# Xircom ethernet
+#wi*		at pcmcia?		# WaveLAN IEEE 802.11DS
+#an*		at pcmcia?		# Aironet IEEE 802.11DS
+
+# IDE/ATAPI (with PCMCIA)
+#wd*		at wdc?	flags 0x0000
+#atapiscsi*	at wdc?
+
+option  MULTIPROCESSOR
+#option MP_LOCKDEBUG
Index: sys/arch/luna88k/conf/files.luna88k
===================================================================
RCS file: /cvs/src/sys/arch/luna88k/conf/files.luna88k,v
retrieving revision 1.32
diff -u -r1.32 files.luna88k
--- sys/arch/luna88k/conf/files.luna88k	7 Jun 2020 22:54:58 -0000	1.32
+++ sys/arch/luna88k/conf/files.luna88k	17 Aug 2020 11:55:33 -0000
@@ -83,6 +83,11 @@
 file	arch/luna88k/cbus/nec86.c			necsb needs-flag
 file	arch/luna88k/cbus/nec86hw.c			necsb needs-flag
 
+# NEC PC-9801-100 SCSI-2 interface board
+attach	aic at cbus with aic_cbus
+file	arch/luna88k/cbus/aic6360_cbus.c		aic needs-flag
+file	arch/luna88k/cbus/aic_cbus.c			aic needs-flag
+
 # PCMCIA devices via NEC PC-9801-102 / PC-9821X[AE]-E01
 device	pcic: pcmciabus
 attach	pcic at cbus with pcic_cbus