/*      $NetBSD: iha.c,v 1.46 2025/04/17 18:53:23 andvar Exp $ */

/*-
 * Copyright (c) 2001, 2002 Izumi Tsutsui
 *
 * 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.
 *
 * 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.
 */

/*-
 * Device driver for the INI-9XXXU/UW or INIC-940/950 PCI SCSI Controller.
 *
 *  Written for 386bsd and FreeBSD by
 *      Winston Hung            <winstonh@initio.com>
 *
 * Copyright (c) 1997-1999 Initio Corp.
 * Copyright (c) 2000, 2001 Ken Westerback
 * 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,
 *    without modification, immediately at the beginning of the file.
 * 2. 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 OR HIS RELATIVES 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 MIND, 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.
 */

/*
 * Ported to NetBSD by Izumi Tsutsui <tsutsui@NetBSD.org> from OpenBSD:
 * $OpenBSD: iha.c,v 1.3 2001/02/20 00:47:33 krw Exp $
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: iha.c,v 1.46 2025/04/17 18:53:23 andvar Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/malloc.h>

#include <sys/bus.h>
#include <sys/intr.h>

#include <dev/scsipi/scsi_spc.h>
#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsiconf.h>
#include <dev/scsipi/scsi_message.h>

#include <dev/ic/ihareg.h>
#include <dev/ic/ihavar.h>

/*
 * SCSI Rate Table, indexed by FLAG_SCSI_RATE field of
 * tcs flags.
 */
static const uint8_t iha_rate_tbl[] = {
        /* fast 20                */
        /* nanosecond divide by 4 */
        12,     /* 50ns,  20M     */
        18,     /* 75ns,  13.3M   */
        25,     /* 100ns, 10M     */
        31,     /* 125ns, 8M      */
        37,     /* 150ns, 6.6M    */
        43,     /* 175ns, 5.7M    */
        50,     /* 200ns, 5M      */
        62      /* 250ns, 4M      */
};
#define IHA_MAX_PERIOD  62

#ifdef notused
static uint16_t eeprom_default[EEPROM_SIZE] = {
        /* -- Header ------------------------------------ */
        /* signature */
        EEP_SIGNATURE,
        /* size, revision */
        EEP_WORD(EEPROM_SIZE * 2, 0x01),
        /* -- Host Adapter Structure -------------------- */
        /* model */
        0x0095,
        /* model info, number of channel */
        EEP_WORD(0x00, 1),
        /* BIOS config */
        EEP_BIOSCFG_DEFAULT,
        /* host adapter config */
        0,

        /* -- eeprom_adapter[0] ------------------------------- */
        /* ID, adapter config 1 */
        EEP_WORD(7, CFG_DEFAULT),
        /* adapter config 2, number of targets */
        EEP_WORD(0x00, 8),
        /* target flags */
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),

        /* -- eeprom_adapter[1] ------------------------------- */
        /* ID, adapter config 1 */
        EEP_WORD(7, CFG_DEFAULT),
        /* adapter config 2, number of targets */
        EEP_WORD(0x00, 8),
        /* target flags */
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        EEP_WORD(FLAG_DEFAULT, FLAG_DEFAULT),
        /* reserved[5] */
        0, 0, 0, 0, 0,
        /* checksum */
        0
};
#endif

static void iha_append_free_scb(struct iha_softc *, struct iha_scb *);
static void iha_append_done_scb(struct iha_softc *, struct iha_scb *, uint8_t);
static inline struct iha_scb *iha_pop_done_scb(struct iha_softc *);

static struct iha_scb *iha_find_pend_scb(struct iha_softc *);
static inline void iha_append_pend_scb(struct iha_softc *, struct iha_scb *);
static inline void iha_push_pend_scb(struct iha_softc *, struct iha_scb *);
static inline void iha_del_pend_scb(struct iha_softc *, struct iha_scb *);
static inline void iha_mark_busy_scb(struct iha_scb *);

static inline void iha_set_ssig(struct iha_softc *, uint8_t, uint8_t);

static int iha_alloc_sglist(struct iha_softc *);

static void iha_scsipi_request(struct scsipi_channel *, scsipi_adapter_req_t,
    void *);
static void iha_update_xfer_mode(struct iha_softc *, int);

static void iha_reset_scsi_bus(struct iha_softc *);
static void iha_reset_chip(struct iha_softc *);
static void iha_reset_dma(struct iha_softc *);
static void iha_reset_tcs(struct tcs *, uint8_t);

static void iha_main(struct iha_softc *);
static void iha_scsi(struct iha_softc *);
static void iha_select(struct iha_softc *, struct iha_scb *, uint8_t);
static int iha_wait(struct iha_softc *, uint8_t);

static void iha_exec_scb(struct iha_softc *, struct iha_scb *);
static void iha_done_scb(struct iha_softc *, struct iha_scb *);
static int iha_push_sense_request(struct iha_softc *, struct iha_scb *);

static void iha_timeout(void *);
static void iha_abort_xs(struct iha_softc *, struct scsipi_xfer *, uint8_t);
static uint8_t iha_data_over_run(struct iha_scb *);

static int iha_next_state(struct iha_softc *);
static int iha_state_1(struct iha_softc *);
static int iha_state_2(struct iha_softc *);
static int iha_state_3(struct iha_softc *);
static int iha_state_4(struct iha_softc *);
static int iha_state_5(struct iha_softc *);
static int iha_state_6(struct iha_softc *);
static int iha_state_8(struct iha_softc *);

static int iha_xfer_data(struct iha_softc *, struct iha_scb *, int);
static int iha_xpad_in(struct iha_softc *);
static int iha_xpad_out(struct iha_softc *);

static int iha_status_msg(struct iha_softc *);
static void iha_busfree(struct iha_softc *);
static int iha_resel(struct iha_softc *);

static int iha_msgin(struct iha_softc *);
static int iha_msgin_extended(struct iha_softc *);
static int iha_msgin_sdtr(struct iha_softc *);
static int iha_msgin_ignore_wid_resid(struct iha_softc *);

static int  iha_msgout(struct iha_softc *, uint8_t);
static void iha_msgout_abort(struct iha_softc *, uint8_t);
static int  iha_msgout_reject(struct iha_softc *);
static int  iha_msgout_extended(struct iha_softc *);
static int  iha_msgout_wdtr(struct iha_softc *);
static int  iha_msgout_sdtr(struct iha_softc *);

static void iha_wide_done(struct iha_softc *);
static void iha_sync_done(struct iha_softc *);

static void iha_bad_seq(struct iha_softc *);

static void iha_read_eeprom(struct iha_softc *, struct iha_eeprom *);
static int iha_se2_rd_all(struct iha_softc *, uint16_t *);
static void iha_se2_instr(struct iha_softc *, int);
static uint16_t iha_se2_rd(struct iha_softc *, int);
#ifdef notused
static void iha_se2_update_all(struct iha_softc *);
static void iha_se2_wr(struct iha_softc *, int, uint16_t);
#endif

/*
 * iha_append_free_scb - append the supplied SCB to the tail of the
 *                       sc_freescb queue after clearing and resetting
 *                       everything possible.
 */
static void
iha_append_free_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        int s;

        s = splbio();

        if (scb == sc->sc_actscb)
                sc->sc_actscb = NULL;

        scb->status = STATUS_QUEUED;
        scb->ha_stat = HOST_OK;
        scb->ta_stat = SCSI_OK;

        scb->nextstat = 0;
        scb->scb_tagmsg = 0;

        scb->xs = NULL;
        scb->tcs = NULL;

        /*
         * scb_tagid, sg_addr, sglist
         * SCB_SensePtr are set at initialization
         * and never change
         */

        TAILQ_INSERT_TAIL(&sc->sc_freescb, scb, chain);

        splx(s);
}

static void
iha_append_done_scb(struct iha_softc *sc, struct iha_scb *scb, uint8_t hastat)
{
        struct tcs *tcs;
        int s;

        s = splbio();

        if (scb->xs != NULL)
                callout_stop(&scb->xs->xs_callout);

        if (scb == sc->sc_actscb)
                sc->sc_actscb = NULL;

        tcs = scb->tcs;

        if (scb->scb_tagmsg != 0) {
                if (tcs->tagcnt)
                        tcs->tagcnt--;
        } else if (tcs->ntagscb == scb)
                tcs->ntagscb = NULL;

        scb->status = STATUS_QUEUED;
        scb->ha_stat = hastat;

        TAILQ_INSERT_TAIL(&sc->sc_donescb, scb, chain);

        splx(s);
}

static inline struct iha_scb *
iha_pop_done_scb(struct iha_softc *sc)
{
        struct iha_scb *scb;
        int s;

        s = splbio();

        scb = TAILQ_FIRST(&sc->sc_donescb);

        if (scb != NULL) {
                scb->status = STATUS_RENT;
                TAILQ_REMOVE(&sc->sc_donescb, scb, chain);
        }

        splx(s);

        return (scb);
}

/*
 * iha_find_pend_scb - scan the pending queue for a SCB that can be
 *                     processed immediately. Return NULL if none found
 *                     and a pointer to the SCB if one is found. If there
 *                     is an active SCB, return NULL!
 */
static struct iha_scb *
iha_find_pend_scb(struct iha_softc *sc)
{
        struct iha_scb *scb;
        struct tcs *tcs;
        int s;

        s = splbio();

        if (sc->sc_actscb != NULL)
                scb = NULL;

        else
                TAILQ_FOREACH(scb, &sc->sc_pendscb, chain) {
                        if ((scb->xs->xs_control & XS_CTL_RESET) != 0)
                                /* ALWAYS willing to reset a device */
                                break;

                        tcs = scb->tcs;

                        if ((scb->scb_tagmsg) != 0) {
                                /*
                                 * A Tagged I/O. OK to start If no
                                 * non-tagged I/O is active on the same
                                 * target
                                 */
                                if (tcs->ntagscb == NULL)
                                        break;

                        } else  if (scb->cmd[0] == SCSI_REQUEST_SENSE) {
                                /*
                                 * OK to do a non-tagged request sense
                                 * even if a non-tagged I/O has been
                                 * started, 'cuz we don't allow any
                                 * disconnect during a request sense op
                                 */
                                break;

                        } else  if (tcs->tagcnt == 0) {
                                /*
                                 * No tagged I/O active on this target,
                                 * ok to start a non-tagged one if one
                                 * is not already active
                                 */
                                if (tcs->ntagscb == NULL)
                                        break;
                        }
                }

        splx(s);

        return (scb);
}

static inline void
iha_append_pend_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        /* ASSUMPTION: only called within a splbio()/splx() pair */

        if (scb == sc->sc_actscb)
                sc->sc_actscb = NULL;

        scb->status = STATUS_QUEUED;

        TAILQ_INSERT_TAIL(&sc->sc_pendscb, scb, chain);
}

static inline void
iha_push_pend_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        int s;

        s = splbio();

        if (scb == sc->sc_actscb)
                sc->sc_actscb = NULL;

        scb->status = STATUS_QUEUED;

        TAILQ_INSERT_HEAD(&sc->sc_pendscb, scb, chain);

        splx(s);
}

/*
 * iha_del_pend_scb - remove scb from sc_pendscb
 */
static inline void
iha_del_pend_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        int s;

        s = splbio();

        TAILQ_REMOVE(&sc->sc_pendscb, scb, chain);

        splx(s);
}

static inline void
iha_mark_busy_scb(struct iha_scb *scb)
{
        int  s;

        s = splbio();

        scb->status = STATUS_BUSY;

        if (scb->scb_tagmsg == 0)
                scb->tcs->ntagscb = scb;
        else
                scb->tcs->tagcnt++;

        splx(s);
}

/*
 * iha_set_ssig - read the current scsi signal mask, then write a new
 *                one which turns off/on the specified signals.
 */
static inline void
iha_set_ssig(struct iha_softc *sc, uint8_t offsigs, uint8_t onsigs)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        uint8_t currsigs;

        currsigs = bus_space_read_1(iot, ioh, TUL_SSIGI);
        bus_space_write_1(iot, ioh, TUL_SSIGO, (currsigs & ~offsigs) | onsigs);
}

/*
 * iha_intr - the interrupt service routine for the iha driver
 */
int
iha_intr(void *arg)
{
        bus_space_tag_t iot;
        bus_space_handle_t ioh;
        struct iha_softc *sc;
        int s;

        sc  = (struct iha_softc *)arg;
        iot = sc->sc_iot;
        ioh = sc->sc_ioh;

        if ((bus_space_read_1(iot, ioh, TUL_STAT0) & INTPD) == 0)
                return (0);

        s = splbio(); /* XXX - Or are interrupts off when ISR's are called? */

        if (sc->sc_semaph != SEMAPH_IN_MAIN) {
                /* XXX - need these inside a splbio()/splx()? */
                bus_space_write_1(iot, ioh, TUL_IMSK, MASK_ALL);
                sc->sc_semaph = SEMAPH_IN_MAIN;

                iha_main(sc);

                sc->sc_semaph = ~SEMAPH_IN_MAIN;
                bus_space_write_1(iot, ioh, TUL_IMSK, (MASK_ALL & ~MSCMP));
        }

        splx(s);

        return (1);
}

void
iha_attach(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;
        struct iha_eeprom eeprom;
        struct eeprom_adapter *conf;
        int i, error, reg;

        iha_read_eeprom(sc, &eeprom);

        conf = &eeprom.adapter[0];

        /*
         * fill in the rest of the iha_softc fields
         */
        sc->sc_id = CFG_ID(conf->config1);
        sc->sc_semaph = ~SEMAPH_IN_MAIN;
        sc->sc_status0 = 0;
        sc->sc_actscb = NULL;

        TAILQ_INIT(&sc->sc_freescb);
        TAILQ_INIT(&sc->sc_pendscb);
        TAILQ_INIT(&sc->sc_donescb);
        error = iha_alloc_sglist(sc);
        if (error != 0) {
                aprint_error_dev(sc->sc_dev, "cannot allocate sglist\n");
                return;
        }

        sc->sc_scb = malloc(sizeof(struct iha_scb) * IHA_MAX_SCB,
            M_DEVBUF, M_WAITOK|M_ZERO);
        for (i = 0, scb = sc->sc_scb; i < IHA_MAX_SCB; i++, scb++) {
                scb->scb_tagid = i;
                scb->sgoffset = IHA_SG_SIZE * i;
                scb->sglist = sc->sc_sglist + IHA_MAX_SG_ENTRIES * i;
                scb->sg_addr =
                    sc->sc_dmamap->dm_segs[0].ds_addr + scb->sgoffset;

                error = bus_dmamap_create(sc->sc_dmat,
                    MAXPHYS, IHA_MAX_SG_ENTRIES, MAXPHYS, 0,
                    BUS_DMA_NOWAIT, &scb->dmap);

                if (error != 0) {
                        aprint_error_dev(sc->sc_dev,
                            "couldn't create SCB DMA map, error = %d\n",
                            error);
                        return;
                }
                TAILQ_INSERT_TAIL(&sc->sc_freescb, scb, chain);
        }

        /* Mask all the interrupts */
        bus_space_write_1(iot, ioh, TUL_IMSK, MASK_ALL);

        /* Stop any I/O and reset the scsi module */
        iha_reset_dma(sc);
        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSMOD);

        /* Program HBA's SCSI ID */
        bus_space_write_1(iot, ioh, TUL_SID, sc->sc_id << 4);

        /*
         * Configure the channel as requested by the NVRAM settings read
         * by iha_read_eeprom() above.
         */

        sc->sc_sconf1 = SCONFIG0DEFAULT;
        if ((conf->config1 & CFG_EN_PAR) != 0)
                sc->sc_sconf1 |= SPCHK;
        bus_space_write_1(iot, ioh, TUL_SCONFIG0, sc->sc_sconf1);

        /* set selection time out 250 ms */
        bus_space_write_1(iot, ioh, TUL_STIMO, STIMO_250MS);

        /* Enable desired SCSI termination configuration read from eeprom */
        reg = 0;
        if (conf->config1 & CFG_ACT_TERM1)
                reg |= ENTMW;
        if (conf->config1 & CFG_ACT_TERM2)
                reg |= ENTM;
        bus_space_write_1(iot, ioh, TUL_DCTRL0, reg);

        reg = bus_space_read_1(iot, ioh, TUL_GCTRL1) & ~ATDEN;
        if (conf->config1 & CFG_AUTO_TERM)
                reg |= ATDEN;
        bus_space_write_1(iot, ioh, TUL_GCTRL1, reg);

        for (i = 0; i < IHA_MAX_TARGETS / 2; i++) {
                sc->sc_tcs[i * 2    ].flags = EEP_LBYTE(conf->tflags[i]);
                sc->sc_tcs[i * 2 + 1].flags = EEP_HBYTE(conf->tflags[i]);
                iha_reset_tcs(&sc->sc_tcs[i * 2    ], sc->sc_sconf1);
                iha_reset_tcs(&sc->sc_tcs[i * 2 + 1], sc->sc_sconf1);
        }

        iha_reset_chip(sc);
        bus_space_write_1(iot, ioh, TUL_SIEN, ALL_INTERRUPTS);

        /*
         * fill in the adapter.
         */
        sc->sc_adapter.adapt_dev = sc->sc_dev;
        sc->sc_adapter.adapt_nchannels = 1;
        sc->sc_adapter.adapt_openings = IHA_MAX_SCB;
        sc->sc_adapter.adapt_max_periph = IHA_MAX_SCB;
        sc->sc_adapter.adapt_ioctl = NULL;
        sc->sc_adapter.adapt_minphys = minphys;
        sc->sc_adapter.adapt_request = iha_scsipi_request;

        /*
         * fill in the channel.
         */
        sc->sc_channel.chan_adapter = &sc->sc_adapter;
        sc->sc_channel.chan_bustype = &scsi_bustype;
        sc->sc_channel.chan_channel = 0;
        sc->sc_channel.chan_ntargets = CFG_TARGET(conf->config2);
        sc->sc_channel.chan_nluns = 8;
        sc->sc_channel.chan_id = sc->sc_id;

        /*
         * Now try to attach all the sub devices.
         */
        config_found(sc->sc_dev, &sc->sc_channel, scsiprint, CFARGS_NONE);
}

/*
 * iha_alloc_sglist - allocate and map sglist for SCB's
 */
static int
iha_alloc_sglist(struct iha_softc *sc)
{
        bus_dma_segment_t seg;
        int error, rseg;

        /*
         * Allocate DMA-safe memory for the SCB's sglist
         */
        if ((error = bus_dmamem_alloc(sc->sc_dmat,
            IHA_SG_SIZE * IHA_MAX_SCB,
            PAGE_SIZE, 0, &seg, 1, &rseg, BUS_DMA_NOWAIT)) != 0) {
                printf(": unable to allocate sglist, error = %d\n", error);
                return (error);
        }
        if ((error = bus_dmamem_map(sc->sc_dmat, &seg, rseg,
            IHA_SG_SIZE * IHA_MAX_SCB, (void **)&sc->sc_sglist,
            BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
                printf(": unable to map sglist, error = %d\n", error);
                return (error);
        }

        /*
         * Create and load the DMA map used for the SCBs
         */
        if ((error = bus_dmamap_create(sc->sc_dmat,
            IHA_SG_SIZE * IHA_MAX_SCB, 1, IHA_SG_SIZE * IHA_MAX_SCB,
            0, BUS_DMA_NOWAIT, &sc->sc_dmamap)) != 0) {
                printf(": unable to create control DMA map, error = %d\n",
                    error);
                return (error);
        }
        if ((error = bus_dmamap_load(sc->sc_dmat, sc->sc_dmamap,
            sc->sc_sglist, IHA_SG_SIZE * IHA_MAX_SCB,
            NULL, BUS_DMA_NOWAIT)) != 0) {
                printf(": unable to load control DMA map, error = %d\n", error);
                return (error);
        }

        memset(sc->sc_sglist, 0, IHA_SG_SIZE * IHA_MAX_SCB);

        return (0);
}

void
iha_scsipi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
    void *arg)
{
        struct scsipi_xfer *xs;
        struct scsipi_periph *periph;
        struct iha_scb *scb;
        struct iha_softc *sc;
        int error, s;

        sc = device_private(chan->chan_adapter->adapt_dev);

        switch (req) {
        case ADAPTER_REQ_RUN_XFER:
                xs = arg;
                periph = xs->xs_periph;

                /* XXX This size isn't actually a hardware restriction. */
                if (xs->cmdlen > sizeof(scb->cmd) ||
                    periph->periph_target >= IHA_MAX_TARGETS) {
                        xs->error = XS_DRIVER_STUFFUP;
                        scsipi_done(xs);
                        return;
                }

                s = splbio();
                scb = TAILQ_FIRST(&sc->sc_freescb);
                if (scb != NULL) {
                        scb->status = STATUS_RENT;
                        TAILQ_REMOVE(&sc->sc_freescb, scb, chain);
                }
                else {
                        printf("unable to allocate scb\n");
#ifdef DIAGNOSTIC
                        scsipi_printaddr(periph);
                        panic("iha_scsipi_request");
#else
                        splx(s);
                        return;
#endif
                }
                splx(s);

                scb->target = periph->periph_target;
                scb->lun = periph->periph_lun;
                scb->tcs = &sc->sc_tcs[scb->target];
                scb->scb_id = MSG_IDENTIFY(periph->periph_lun,
                    (xs->xs_control & XS_CTL_REQSENSE) == 0);

                scb->xs = xs;
                scb->cmdlen = xs->cmdlen;
                memcpy(&scb->cmd, xs->cmd, xs->cmdlen);
                scb->buflen = xs->datalen;
                scb->flags = 0;
                if (xs->xs_control & XS_CTL_DATA_OUT)
                        scb->flags |= FLAG_DATAOUT;
                if (xs->xs_control & XS_CTL_DATA_IN)
                        scb->flags |= FLAG_DATAIN;

                if (scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) {
                        error = bus_dmamap_load(sc->sc_dmat, scb->dmap,
                            xs->data, scb->buflen, NULL,
                            ((xs->xs_control & XS_CTL_NOSLEEP) ?
                             BUS_DMA_NOWAIT : BUS_DMA_WAITOK) |
                            BUS_DMA_STREAMING |
                            ((scb->flags & FLAG_DATAIN) ?
                             BUS_DMA_READ : BUS_DMA_WRITE));

                        if (error) {
                                printf("%s: error %d loading DMA map\n",
                                    device_xname(sc->sc_dev), error);
                                iha_append_free_scb(sc, scb);
                                xs->error = XS_DRIVER_STUFFUP;
                                scsipi_done(xs);
                                return;
                        }
                        bus_dmamap_sync(sc->sc_dmat, scb->dmap,
                            0, scb->dmap->dm_mapsize,
                            (scb->flags & FLAG_DATAIN) ?
                            BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
                }

                iha_exec_scb(sc, scb);
                return;

        case ADAPTER_REQ_GROW_RESOURCES:
                return; /* XXX */

        case ADAPTER_REQ_SET_XFER_MODE:
                {
                        struct tcs *tcs;
                        struct scsipi_xfer_mode *xm = arg;

                        tcs = &sc->sc_tcs[xm->xm_target];

                        if ((xm->xm_mode & PERIPH_CAP_WIDE16) != 0 &&
                            (tcs->flags & FLAG_NO_WIDE) == 0)
                                tcs->flags &= ~(FLAG_WIDE_DONE|FLAG_SYNC_DONE);

                        if ((xm->xm_mode & PERIPH_CAP_SYNC) != 0 &&
                            (tcs->flags & FLAG_NO_SYNC) == 0)
                                tcs->flags &= ~FLAG_SYNC_DONE;

                        /*
                         * If we're not going to negotiate, send the
                         * notification now, since it won't happen later.
                         */
                        if ((tcs->flags & (FLAG_WIDE_DONE|FLAG_SYNC_DONE)) ==
                            (FLAG_WIDE_DONE|FLAG_SYNC_DONE))
                                iha_update_xfer_mode(sc, xm->xm_target);

                        return;
                }
        }
}

void
iha_update_xfer_mode(struct iha_softc *sc, int target)
{
        struct tcs *tcs = &sc->sc_tcs[target];
        struct scsipi_xfer_mode xm;

        xm.xm_target = target;
        xm.xm_mode = 0;
        xm.xm_period = 0;
        xm.xm_offset = 0;

        if (tcs->syncm & PERIOD_WIDE_SCSI)
                xm.xm_mode |= PERIPH_CAP_WIDE16;

        if (tcs->period) {
                xm.xm_mode |= PERIPH_CAP_SYNC;
                xm.xm_period = tcs->period;
                xm.xm_offset = tcs->offset;
        }

        scsipi_async_event(&sc->sc_channel, ASYNC_EVENT_XFER_MODE, &xm);
}

static void
iha_reset_scsi_bus(struct iha_softc *sc)
{
        struct iha_scb *scb;
        struct tcs *tcs;
        int i, s;

        s = splbio();

        iha_reset_dma(sc);

        for (i = 0, scb = sc->sc_scb; i < IHA_MAX_SCB; i++, scb++)
                switch (scb->status) {
                case STATUS_BUSY:
                        iha_append_done_scb(sc, scb, HOST_SCSI_RST);
                        break;

                case STATUS_SELECT:
                        iha_push_pend_scb(sc, scb);
                        break;

                default:
                        break;
                }

        for (i = 0, tcs = sc->sc_tcs; i < IHA_MAX_TARGETS; i++, tcs++)
                iha_reset_tcs(tcs, sc->sc_sconf1);

        splx(s);
}

void
iha_reset_chip(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        /* reset tulip chip */

        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSCSI);

        do {
                sc->sc_sistat = bus_space_read_1(iot, ioh, TUL_SISTAT);
        } while ((sc->sc_sistat & SRSTD) == 0);

        iha_set_ssig(sc, 0, 0);

        /* Clear any active interrupt*/
        (void)bus_space_read_1(iot, ioh, TUL_SISTAT);
}

/*
 * iha_reset_dma - abort any active DMA xfer, reset tulip FIFO.
 */
static void
iha_reset_dma(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        if ((bus_space_read_1(iot, ioh, TUL_ISTUS1) & XPEND) != 0) {
                /* if DMA xfer is pending, abort DMA xfer */
                bus_space_write_1(iot, ioh, TUL_DCMD, ABTXFR);
                /* wait Abort DMA xfer done */
                while ((bus_space_read_1(iot, ioh, TUL_ISTUS0) & DABT) == 0)
                        ;
        }

        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
}

/*
 * iha_reset_tcs - reset the target control structure pointed
 *                 to by tcs to default values. tcs flags
 *                 only has the negotiation done bits reset as
 *                 the other bits are fixed at initialization.
 */
static void
iha_reset_tcs(struct tcs *tcs, uint8_t config0)
{

        tcs->flags &= ~(FLAG_SYNC_DONE | FLAG_WIDE_DONE);
        tcs->period = 0;
        tcs->offset = 0;
        tcs->tagcnt = 0;
        tcs->ntagscb  = NULL;
        tcs->syncm = 0;
        tcs->sconfig0 = config0;
}

/*
 * iha_main - process the active SCB, taking one off pending and making it
 *            active if necessary, and any done SCB's created as
 *            a result until there are no interrupts pending and no pending
 *            SCB's that can be started.
 */
static void
iha_main(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh =sc->sc_ioh;
        struct iha_scb *scb;

        for (;;) {
                iha_scsi(sc);

                while ((scb = iha_pop_done_scb(sc)) != NULL)
                        iha_done_scb(sc, scb);

                /*
                 * If there are no interrupts pending, or we can't start
                 * a pending sc, break out of the for(;;). Otherwise
                 * continue the good work with another call to
                 * iha_scsi().
                 */
                if (((bus_space_read_1(iot, ioh, TUL_STAT0) & INTPD) == 0)
                    && (iha_find_pend_scb(sc) == NULL))
                        break;
        }
}

/*
 * iha_scsi - service any outstanding interrupts. If there are none, try to
 *            start another SCB currently in the pending queue.
 */
static void
iha_scsi(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;
        struct tcs *tcs;
        uint8_t stat;

        /* service pending interrupts asap */

        stat = bus_space_read_1(iot, ioh, TUL_STAT0);
        if ((stat & INTPD) != 0) {
                sc->sc_status0 = stat;
                sc->sc_status1 = bus_space_read_1(iot, ioh, TUL_STAT1);
                sc->sc_sistat = bus_space_read_1(iot, ioh, TUL_SISTAT);

                sc->sc_phase = sc->sc_status0 & PH_MASK;

                if ((sc->sc_sistat & SRSTD) != 0) {
                        iha_reset_scsi_bus(sc);
                        return;
                }

                if ((sc->sc_sistat & RSELED) != 0) {
                        iha_resel(sc);
                        return;
                }

                if ((sc->sc_sistat & (STIMEO | DISCD)) != 0) {
                        iha_busfree(sc);
                        return;
                }

                if ((sc->sc_sistat & (SCMDN | SBSRV)) != 0) {
                        iha_next_state(sc);
                        return;
                }

                if ((sc->sc_sistat & SELED) != 0)
                        iha_set_ssig(sc, 0, 0);
        }

        /*
         * There were no interrupts pending which required action elsewhere, so
         * see if it is possible to start the selection phase on a pending SCB
         */
        if ((scb = iha_find_pend_scb(sc)) == NULL)
                return;

        tcs = scb->tcs;

        /* program HBA's SCSI ID & target SCSI ID */
        bus_space_write_1(iot, ioh, TUL_SID, (sc->sc_id << 4) | scb->target);

        if ((scb->xs->xs_control & XS_CTL_RESET) == 0) {
                bus_space_write_1(iot, ioh, TUL_SYNCM, tcs->syncm);

                if ((tcs->flags & FLAG_NO_NEG_SYNC) == 0 ||
                    (tcs->flags & FLAG_NO_NEG_WIDE) == 0)
                        iha_select(sc, scb, SELATNSTOP);

                else if (scb->scb_tagmsg != 0)
                        iha_select(sc, scb, SEL_ATN3);

                else
                        iha_select(sc, scb, SEL_ATN);

        } else {
                iha_select(sc, scb, SELATNSTOP);
                scb->nextstat = 8;
        }

        if ((scb->xs->xs_control & XS_CTL_POLL) != 0) {
                int timeout;
                for (timeout = scb->xs->timeout; timeout > 0; timeout--) {
                        if (iha_wait(sc, NO_OP) == -1)
                                break;
                        if (iha_next_state(sc) == -1)
                                break;
                        delay(1000); /* Only happens in boot, so it's ok */
                }

                /*
                 * Since done queue processing not done until AFTER this
                 * function returns, scb is on the done queue, not
                 * the free queue at this point and still has valid data
                 *
                 * Conversely, xs->error has not been set yet
                 */
                if (timeout == 0)
                        iha_timeout(scb);
        }
}

static void
iha_select(struct iha_softc *sc, struct iha_scb *scb, uint8_t select_type)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        switch (select_type) {
        case SEL_ATN:
                bus_space_write_1(iot, ioh, TUL_SFIFO, scb->scb_id);
                bus_space_write_multi_1(iot, ioh, TUL_SFIFO,
                    scb->cmd, scb->cmdlen);

                scb->nextstat = 2;
                break;

        case SELATNSTOP:
                scb->nextstat = 1;
                break;

        case SEL_ATN3:
                bus_space_write_1(iot, ioh, TUL_SFIFO, scb->scb_id);
                bus_space_write_1(iot, ioh, TUL_SFIFO, scb->scb_tagmsg);
                bus_space_write_1(iot, ioh, TUL_SFIFO, scb->scb_tagid);

                bus_space_write_multi_1(iot, ioh, TUL_SFIFO, scb->cmd,
                    scb->cmdlen);

                scb->nextstat = 2;
                break;

        default:
                printf("[debug] iha_select() - unknown select type = 0x%02x\n",
                    select_type);
                return;
        }

        iha_del_pend_scb(sc, scb);
        scb->status = STATUS_SELECT;

        sc->sc_actscb = scb;

        bus_space_write_1(iot, ioh, TUL_SCMD, select_type);
}

/*
 * iha_wait - wait for an interrupt to service or a SCSI bus phase change
 *            after writing the supplied command to the tulip chip. If
 *            the command is NO_OP, skip the command writing.
 */
static int
iha_wait(struct iha_softc *sc, uint8_t cmd)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

        if (cmd != NO_OP)
                bus_space_write_1(iot, ioh, TUL_SCMD, cmd);

        /*
         * Have to do this here, in addition to in iha_isr, because
         * interrupts might be turned off when we get here.
         */
        do {
                sc->sc_status0 = bus_space_read_1(iot, ioh, TUL_STAT0);
        } while ((sc->sc_status0 & INTPD) == 0);

        sc->sc_status1 = bus_space_read_1(iot, ioh, TUL_STAT1);
        sc->sc_sistat = bus_space_read_1(iot, ioh, TUL_SISTAT);

        sc->sc_phase = sc->sc_status0 & PH_MASK;

        if ((sc->sc_sistat & SRSTD) != 0) {
                /* SCSI bus reset interrupt */
                iha_reset_scsi_bus(sc);
                return (-1);
        }

        if ((sc->sc_sistat & RSELED) != 0)
                /* Reselection interrupt */
                return (iha_resel(sc));

        if ((sc->sc_sistat & STIMEO) != 0) {
                /* selected/reselected timeout interrupt */
                iha_busfree(sc);
                return (-1);
        }

        if ((sc->sc_sistat & DISCD) != 0) {
                /* BUS disconnection interrupt */
                if ((sc->sc_flags & FLAG_EXPECT_DONE_DISC) != 0) {
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        bus_space_write_1(iot, ioh, TUL_SCONFIG0,
                            SCONFIG0DEFAULT);
                        bus_space_write_1(iot, ioh, TUL_SCTRL1, EHRSL);
                        iha_append_done_scb(sc, sc->sc_actscb, HOST_OK);
                        sc->sc_flags &= ~FLAG_EXPECT_DONE_DISC;

                } else if ((sc->sc_flags & FLAG_EXPECT_DISC) != 0) {
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        bus_space_write_1(iot, ioh, TUL_SCONFIG0,
                            SCONFIG0DEFAULT);
                        bus_space_write_1(iot, ioh, TUL_SCTRL1, EHRSL);
                        sc->sc_actscb = NULL;
                        sc->sc_flags &= ~FLAG_EXPECT_DISC;

                } else
                        iha_busfree(sc);

                return (-1);
        }

        return (sc->sc_phase);
}

static void
iha_exec_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        bus_space_tag_t iot;
        bus_space_handle_t ioh;
        bus_dmamap_t dm;
        struct scsipi_xfer *xs = scb->xs;
        int nseg, s;

        dm = scb->dmap;
        nseg = dm->dm_nsegs;

        if (nseg > 1) {
                struct iha_sg_element *sg = scb->sglist;
                int i;

                for (i = 0; i < nseg; i++) {
                        sg[i].sg_len = htole32(dm->dm_segs[i].ds_len);
                        sg[i].sg_addr = htole32(dm->dm_segs[i].ds_addr);
                }
                bus_dmamap_sync(sc->sc_dmat, sc->sc_dmamap,
                    scb->sgoffset, IHA_SG_SIZE,
                    BUS_DMASYNC_PREWRITE);

                scb->flags |= FLAG_SG;
                scb->sg_size = scb->sg_max = nseg;
                scb->sg_index = 0;

                scb->bufaddr = scb->sg_addr;
        } else
                scb->bufaddr = dm->dm_segs[0].ds_addr;

        if ((xs->xs_control & XS_CTL_POLL) == 0) {
                int timeout = mstohz(xs->timeout);
                if (timeout == 0)
                        timeout = 1;
                callout_reset(&xs->xs_callout, timeout, iha_timeout, scb);
        }

        s = splbio();

        if (((scb->xs->xs_control & XS_RESET) != 0) ||
            (scb->cmd[0] == SCSI_REQUEST_SENSE))
                iha_push_pend_scb(sc, scb);   /* Insert SCB at head of Pend */
        else
                iha_append_pend_scb(sc, scb); /* Append SCB to tail of Pend */

        /*
         * Run through iha_main() to ensure something is active, if
         * only this new SCB.
         */
        if (sc->sc_semaph != SEMAPH_IN_MAIN) {
                iot = sc->sc_iot;
                ioh = sc->sc_ioh;

                bus_space_write_1(iot, ioh, TUL_IMSK, MASK_ALL);
                sc->sc_semaph = SEMAPH_IN_MAIN;

                splx(s);
                iha_main(sc);
                s = splbio();

                sc->sc_semaph = ~SEMAPH_IN_MAIN;
                bus_space_write_1(iot, ioh, TUL_IMSK, (MASK_ALL & ~MSCMP));
        }

        splx(s);
}

/*
 * iha_done_scb - We have a scb which has been processed by the
 *                adaptor, now we look to see how the operation went.
 */
static void
iha_done_scb(struct iha_softc *sc, struct iha_scb *scb)
{
        struct scsipi_xfer *xs = scb->xs;

        if (xs != NULL) {
                /* Cancel the timeout. */
                callout_stop(&xs->xs_callout);

                if (scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) {
                        bus_dmamap_sync(sc->sc_dmat, scb->dmap,
                            0, scb->dmap->dm_mapsize,
                            (scb->flags & FLAG_DATAIN) ?
                            BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->sc_dmat, scb->dmap);
                }

                xs->status = scb->ta_stat;

                switch (scb->ha_stat) {
                case HOST_OK:
                        switch (scb->ta_stat) {
                        case SCSI_OK:
                        case SCSI_CONDITION_MET:
                        case SCSI_INTERM:
                        case SCSI_INTERM_COND_MET:
                                xs->resid = scb->buflen;
                                xs->error = XS_NOERROR;
                                if ((scb->flags & FLAG_RSENS) != 0)
                                        xs->error = XS_SENSE;
                                break;

                        case SCSI_RESV_CONFLICT:
                        case SCSI_BUSY:
                        case SCSI_QUEUE_FULL:
                                xs->error = XS_BUSY;
                                break;

                        case SCSI_TERMINATED:
                        case SCSI_ACA_ACTIVE:
                        case SCSI_CHECK:
                                scb->tcs->flags &=
                                    ~(FLAG_SYNC_DONE | FLAG_WIDE_DONE);

                                if ((scb->flags & FLAG_RSENS) != 0 ||
                                    iha_push_sense_request(sc, scb) != 0) {
                                        scb->flags &= ~FLAG_RSENS;
                                        printf("%s: request sense failed\n",
                                            device_xname(sc->sc_dev));
                                        xs->error = XS_DRIVER_STUFFUP;
                                        break;
                                }

                                xs->error = XS_SENSE;
                                return;

                        default:
                                xs->error = XS_DRIVER_STUFFUP;
                                break;
                        }
                        break;

                case HOST_SEL_TOUT:
                        xs->error = XS_SELTIMEOUT;
                        break;

                case HOST_SCSI_RST:
                case HOST_DEV_RST:
                        xs->error = XS_RESET;
                        break;

                case HOST_SPERR:
                        printf("%s: SCSI Parity error detected\n",
                            device_xname(sc->sc_dev));
                        xs->error = XS_DRIVER_STUFFUP;
                        break;

                case HOST_TIMED_OUT:
                        xs->error = XS_TIMEOUT;
                        break;

                case HOST_DO_DU:
                case HOST_BAD_PHAS:
                default:
                        xs->error = XS_DRIVER_STUFFUP;
                        break;
                }

                scsipi_done(xs);
        }

        iha_append_free_scb(sc, scb);
}

/*
 * iha_push_sense_request - obtain auto sense data by pushing the
 *                          SCB needing it back onto the pending
 *                          queue with a REQUEST_SENSE CDB.
 */
static int
iha_push_sense_request(struct iha_softc *sc, struct iha_scb *scb)
{
        struct scsipi_xfer *xs = scb->xs;
        struct scsipi_periph *periph = xs->xs_periph;
        struct scsi_request_sense *ss = (struct scsi_request_sense *)scb->cmd;
        int lun = periph->periph_lun;
        int err;

        memset(ss, 0, sizeof(*ss));
        ss->opcode = SCSI_REQUEST_SENSE;
        ss->byte2 = lun << SCSI_CMD_LUN_SHIFT;
        ss->length = sizeof(struct scsi_sense_data);

        scb->flags = FLAG_RSENS | FLAG_DATAIN;

        scb->scb_id &= ~MSG_IDENTIFY_DISCFLAG;

        scb->scb_tagmsg = 0;
        scb->ta_stat = SCSI_OK;

        scb->cmdlen = sizeof(struct scsi_request_sense);
        scb->buflen = ss->length;

        err = bus_dmamap_load(sc->sc_dmat, scb->dmap,
            &xs->sense.scsi_sense, scb->buflen, NULL,
            BUS_DMA_READ|BUS_DMA_NOWAIT);
        if (err != 0) {
                printf("iha_push_sense_request: cannot bus_dmamap_load()\n");
                xs->error = XS_DRIVER_STUFFUP;
                return 1;
        }
        bus_dmamap_sync(sc->sc_dmat, scb->dmap,
            0, scb->buflen, BUS_DMASYNC_PREREAD);

        /* XXX What about queued command? */
        iha_exec_scb(sc, scb);

        return 0;
}

static void
iha_timeout(void *arg)
{
        struct iha_scb *scb = (struct iha_scb *)arg;
        struct scsipi_xfer *xs = scb->xs;
        struct scsipi_periph *periph;
        struct iha_softc *sc;

        if (xs == NULL) {
                printf("[debug] iha_timeout called with xs == NULL\n");
                return;
        }

        periph = xs->xs_periph;

        sc = device_private(periph->periph_channel->chan_adapter->adapt_dev);

        scsipi_printaddr(periph);
        printf("SCSI OpCode 0x%02x timed out\n", xs->cmd->opcode);
        iha_abort_xs(sc, xs, HOST_TIMED_OUT);
}

/*
 * iha_abort_xs - find the SCB associated with the supplied xs and
 *                stop all processing on it, moving it to the done
 *                queue with the supplied host status value.
 */
static void
iha_abort_xs(struct iha_softc *sc, struct scsipi_xfer *xs, uint8_t hastat)
{
        struct iha_scb *scb;
        int i, s;

        s = splbio();

        /* Check the pending queue for the SCB pointing to xs */

        TAILQ_FOREACH(scb, &sc->sc_pendscb, chain)
                if (scb->xs == xs) {
                        iha_del_pend_scb(sc, scb);
                        iha_append_done_scb(sc, scb, hastat);
                        splx(s);
                        return;
                }

        /*
         * If that didn't work, check all BUSY/SELECTING SCB's for one
         * pointing to xs
         */

        for (i = 0, scb = sc->sc_scb; i < IHA_MAX_SCB; i++, scb++)
                switch (scb->status) {
                case STATUS_BUSY:
                case STATUS_SELECT:
                        if (scb->xs == xs) {
                                iha_append_done_scb(sc, scb, hastat);
                                splx(s);
                                return;
                        }
                        break;
                default:
                        break;
                }

        splx(s);
}

/*
 * iha_data_over_run - return HOST_OK for all SCSI opcodes where BufLen
 *                     is an 'Allocation Length'. All other SCSI opcodes
 *                     get HOST_DO_DU as they SHOULD have xferred all the
 *                     data requested.
 *
 *                     The list of opcodes using 'Allocation Length' was
 *                     found by scanning all the SCSI-3 T10 drafts. See
 *                     www.t10.org for the curious with a .pdf reader.
 */
static uint8_t
iha_data_over_run(struct iha_scb *scb)
{
        switch (scb->cmd[0]) {
        case 0x03: /* Request Sense                   SPC-2 */
        case 0x12: /* Inquiry                         SPC-2 */
        case 0x1a: /* Mode Sense (6 byte version)     SPC-2 */
        case 0x1c: /* Receive Diagnostic Results      SPC-2 */
        case 0x23: /* Read Format Capacities          MMC-2 */
        case 0x29: /* Read Generation                 SBC   */
        case 0x34: /* Read Position                   SSC-2 */
        case 0x37: /* Read Defect Data                SBC   */
        case 0x3c: /* Read Buffer                     SPC-2 */
        case 0x42: /* Read Sub Channel                MMC-2 */
        case 0x43: /* Read TOC/PMA/ATIP               MMC   */

        /* XXX - 2 with same opcode of 0x44? */
        case 0x44: /* Read Header/Read Density Suprt  MMC/SSC*/

        case 0x46: /* Get Configuration               MMC-2 */
        case 0x4a: /* Get Event/Status Notification   MMC-2 */
        case 0x4d: /* Log Sense                       SPC-2 */
        case 0x51: /* Read Disc Information           MMC   */
        case 0x52: /* Read Track Information          MMC   */
        case 0x59: /* Read Master CUE                 MMC   */
        case 0x5a: /* Mode Sense (10 byte version)    SPC-2 */
        case 0x5c: /* Read Buffer Capacity            MMC   */
        case 0x5e: /* Persistent Reserve In           SPC-2 */
        case 0x84: /* Receive Copy Results            SPC-2 */
        case 0xa0: /* Report LUNs                     SPC-2 */
        case 0xa3: /* Various Report requests         SBC-2/SCC-2*/
        case 0xa4: /* Report Key                      MMC-2 */
        case 0xad: /* Read DVD Structure              MMC-2 */
        case 0xb4: /* Read Element Status (Attached)  SMC   */
        case 0xb5: /* Request Volume Element Address  SMC   */
        case 0xb7: /* Read Defect Data (12 byte ver.) SBC   */
        case 0xb8: /* Read Element Status (Independ.) SMC   */
        case 0xba: /* Report Redundancy               SCC-2 */
        case 0xbd: /* Mechanism Status                MMC   */
        case 0xbe: /* Report Basic Redundancy         SCC-2 */

                return (HOST_OK);

        default:
                return (HOST_DO_DU);
        }
}

/*
 * iha_next_state - process the current SCB as requested in its
 *                  nextstat member.
 */
static int
iha_next_state(struct iha_softc *sc)
{

        if (sc->sc_actscb == NULL)
                return (-1);

        switch (sc->sc_actscb->nextstat) {
        case 1:
                if (iha_state_1(sc) == 3)
                        goto state_3;
                break;

        case 2:
                switch (iha_state_2(sc)) {
                case 3:
                        goto state_3;
                case 4:
                        goto state_4;
                default:
                        break;
                }
                break;

        case 3:
        state_3:
                if (iha_state_3(sc) == 4)
                        goto state_4;
                break;

        case 4:
        state_4:
                switch (iha_state_4(sc)) {
                case 0:
                        return (0);
                case 6:
                        goto state_6;
                default:
                        break;
                }
                break;

        case 5:
                switch (iha_state_5(sc)) {
                case 4:
                        goto state_4;
                case 6:
                        goto state_6;
                default:
                        break;
                }
                break;

        case 6:
        state_6:
                iha_state_6(sc);
                break;

        case 8:
                iha_state_8(sc);
                break;

        default:
#ifdef IHA_DEBUG_STATE
                printf("[debug] -unknown state: %i-\n",
                    sc->sc_actscb->nextstat);
#endif
                iha_bad_seq(sc);
                break;
        }

        return (-1);
}

/*
 * iha_state_1 - selection is complete after a SELATNSTOP. If the target
 *               has put the bus into MSG_OUT phase start wide/sync
 *               negotiation. Otherwise clear the FIFO and go to state 3,
 *               which will send the SCSI CDB to the target.
 */
static int
iha_state_1(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;
        struct tcs *tcs;
        int flags;

        iha_mark_busy_scb(scb);

        tcs = scb->tcs;

        bus_space_write_1(iot, ioh, TUL_SCONFIG0, tcs->sconfig0);

        /*
         * If we are in PHASE_MSG_OUT, send
         *     a) IDENT message (with tags if appropriate)
         *     b) WDTR if the target is configured to negotiate wide xfers
         *     ** OR **
         *     c) SDTR if the target is configured to negotiate sync xfers
         *        but not wide ones
         *
         * If we are NOT, then the target is not asking for anything but
         * the data/command, so go straight to state 3.
         */
        if (sc->sc_phase == PHASE_MSG_OUT) {
                bus_space_write_1(iot, ioh, TUL_SCTRL1, (ESBUSIN | EHRSL));
                bus_space_write_1(iot, ioh, TUL_SFIFO, scb->scb_id);

                if (scb->scb_tagmsg != 0) {
                        bus_space_write_1(iot, ioh, TUL_SFIFO,
                            scb->scb_tagmsg);
                        bus_space_write_1(iot, ioh, TUL_SFIFO,
                            scb->scb_tagid);
                }

                flags = tcs->flags;
                if ((flags & FLAG_NO_NEG_WIDE) == 0) {
                        if (iha_msgout_wdtr(sc) == -1)
                                return (-1);
                } else if ((flags & FLAG_NO_NEG_SYNC) == 0) {
                        if (iha_msgout_sdtr(sc) == -1)
                                return (-1);
                }

        } else {
                bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
        }

        return (3);
}

/*
 * iha_state_2 - selection is complete after a SEL_ATN or SEL_ATN3. If the SCSI
 *               CDB has already been send, go to state 4 to start the data
 *               xfer. Otherwise reset the FIFO and go to state 3, sending
 *               the SCSI CDB.
 */
static int
iha_state_2(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;

        iha_mark_busy_scb(scb);

        bus_space_write_1(iot, ioh, TUL_SCONFIG0, scb->tcs->sconfig0);

        if ((sc->sc_status1 & CPDNE) != 0)
                return (4);

        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);

        iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);

        return (3);
}

/*
 * iha_state_3 - send the SCSI CDB to the target, processing any status
 *               or other messages received until that is done or
 *               abandoned.
 */
static int
iha_state_3(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;
        int flags;

        for (;;) {
                switch (sc->sc_phase) {
                case PHASE_CMD_OUT:
                        bus_space_write_multi_1(iot, ioh, TUL_SFIFO,
                            scb->cmd, scb->cmdlen);
                        if (iha_wait(sc, XF_FIFO_OUT) == -1)
                                return (-1);
                        else if (sc->sc_phase == PHASE_CMD_OUT) {
                                iha_bad_seq(sc);
                                return (-1);
                        } else
                                return (4);

                case PHASE_MSG_IN:
                        scb->nextstat = 3;
                        if (iha_msgin(sc) == -1)
                                return (-1);
                        break;

                case PHASE_STATUS_IN:
                        if (iha_status_msg(sc) == -1)
                                return (-1);
                        break;

                case PHASE_MSG_OUT:
                        flags = scb->tcs->flags;
                        if ((flags & FLAG_NO_NEG_SYNC) != 0) {
                                if (iha_msgout(sc, MSG_NOOP) == -1)
                                        return (-1);
                        } else if (iha_msgout_sdtr(sc) == -1)
                                return (-1);
                        break;

                default:
                        printf("[debug] -s3- bad phase = %d\n", sc->sc_phase);
                        iha_bad_seq(sc);
                        return (-1);
                }
        }
}

/*
 * iha_state_4 - start a data xfer. Handle any bus state
 *               transitions until PHASE_DATA_IN/_OUT
 *               or the attempt is abandoned. If there is
 *               no data to xfer, go to state 6 and finish
 *               processing the current SCB.
 */
static int
iha_state_4(struct iha_softc *sc)
{
        struct iha_scb *scb = sc->sc_actscb;

        if ((scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) ==
            (FLAG_DATAIN | FLAG_DATAOUT))
                return (6); /* Both dir flags set => NO xfer was requested */

        for (;;) {
                if (scb->buflen == 0)
                        return (6);

                switch (sc->sc_phase) {
                case PHASE_STATUS_IN:
                        if ((scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) != 0)
                                scb->ha_stat = iha_data_over_run(scb);
                        if ((iha_status_msg(sc)) == -1)
                                return (-1);
                        break;

                case PHASE_MSG_IN:
                        scb->nextstat = 4;
                        if (iha_msgin(sc) == -1)
                                return (-1);
                        break;

                case PHASE_MSG_OUT:
                        if ((sc->sc_status0 & SPERR) != 0) {
                                scb->buflen = 0;
                                scb->ha_stat = HOST_SPERR;
                                if (iha_msgout(sc, MSG_INITIATOR_DET_ERR) == -1)
                                        return (-1);
                                else
                                        return (6);
                        } else {
                                if (iha_msgout(sc, MSG_NOOP) == -1)
                                        return (-1);
                        }
                        break;

                case PHASE_DATA_IN:
                        return (iha_xfer_data(sc, scb, FLAG_DATAIN));

                case PHASE_DATA_OUT:
                        return (iha_xfer_data(sc, scb, FLAG_DATAOUT));

                default:
                        iha_bad_seq(sc);
                        return (-1);
                }
        }
}

/*
 * iha_state_5 - handle the partial or final completion of the current
 *               data xfer. If DMA is still active stop it. If there is
 *               more data to xfer, go to state 4 and start the xfer.
 *               If not go to state 6 and finish the SCB.
 */
static int
iha_state_5(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;
        struct iha_sg_element *sg;
        uint32_t cnt;
        uint8_t period, stat;
        long xcnt;  /* cannot use unsigned!! see code: if (xcnt < 0) */
        int i;

        cnt = bus_space_read_4(iot, ioh, TUL_STCNT0) & TCNT;

        /*
         * Stop any pending DMA activity and check for parity error.
         */

        if ((bus_space_read_1(iot, ioh, TUL_DCMD) & XDIR) != 0) {
                /* Input Operation */
                if ((sc->sc_status0 & SPERR) != 0)
                        scb->ha_stat = HOST_SPERR;

                if ((bus_space_read_1(iot, ioh, TUL_ISTUS1) & XPEND) != 0) {
                        bus_space_write_1(iot, ioh, TUL_DCTRL0,
                            bus_space_read_1(iot, ioh, TUL_DCTRL0) | SXSTP);
                        while (bus_space_read_1(iot, ioh, TUL_ISTUS1) & XPEND)
                                ;
                }

        } else {
                /* Output Operation */
                if ((sc->sc_status1 & SXCMP) == 0) {
                        period = scb->tcs->syncm;
                        if ((period & PERIOD_WIDE_SCSI) != 0)
                                cnt += (bus_space_read_1(iot, ioh,
                                    TUL_SFIFOCNT) & FIFOC) * 2;
                        else
                                cnt += bus_space_read_1(iot, ioh,
                                    TUL_SFIFOCNT) & FIFOC;
                }

                if ((bus_space_read_1(iot, ioh, TUL_ISTUS1) & XPEND) != 0) {
                        bus_space_write_1(iot, ioh, TUL_DCMD, ABTXFR);
                        do
                                stat = bus_space_read_1(iot, ioh, TUL_ISTUS0);
                        while ((stat & DABT) == 0);
                }

                if ((cnt == 1) && (sc->sc_phase == PHASE_DATA_OUT)) {
                        if (iha_wait(sc, XF_FIFO_OUT) == -1)
                                return (-1);
                        cnt = 0;

                } else if ((sc->sc_status1 & SXCMP) == 0)
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
        }

        if (cnt == 0) {
                scb->buflen = 0;
                return (6);
        }

        /* Update active data pointer and restart the I/O at the new point */

        xcnt = scb->buflen - cnt;       /* xcnt == bytes xferred */
        scb->buflen = cnt;              /* cnt  == bytes left    */

        if ((scb->flags & FLAG_SG) != 0) {
                sg = &scb->sglist[scb->sg_index];
                for (i = scb->sg_index; i < scb->sg_max; sg++, i++) {
                        xcnt -= le32toh(sg->sg_len);
                        if (xcnt < 0) {
                                xcnt += le32toh(sg->sg_len);

                                sg->sg_addr =
                                    htole32(le32toh(sg->sg_addr) + xcnt);
                                sg->sg_len =
                                    htole32(le32toh(sg->sg_len) - xcnt);
                                bus_dmamap_sync(sc->sc_dmat, sc->sc_dmamap,
                                    scb->sgoffset, IHA_SG_SIZE,
                                    BUS_DMASYNC_PREWRITE);

                                scb->bufaddr += (i - scb->sg_index) *
                                    sizeof(struct iha_sg_element);
                                scb->sg_size = scb->sg_max - i;
                                scb->sg_index = i;

                                return (4);
                        }
                }
                return (6);

        } else
                scb->bufaddr += xcnt;

        return (4);
}

/*
 * iha_state_6 - finish off the active scb (may require several
 *               iterations if PHASE_MSG_IN) and return -1 to indicate
 *               the bus is free.
 */
static int
iha_state_6(struct iha_softc *sc)
{

        for (;;) {
                switch (sc->sc_phase) {
                case PHASE_STATUS_IN:
                        if (iha_status_msg(sc) == -1)
                                return (-1);
                        break;

                case PHASE_MSG_IN:
                        sc->sc_actscb->nextstat = 6;
                        if ((iha_msgin(sc)) == -1)
                                return (-1);
                        break;

                case PHASE_MSG_OUT:
                        if ((iha_msgout(sc, MSG_NOOP)) == -1)
                                return (-1);
                        break;

                case PHASE_DATA_IN:
                        if (iha_xpad_in(sc) == -1)
                                return (-1);
                        break;

                case PHASE_DATA_OUT:
                        if (iha_xpad_out(sc) == -1)
                                return (-1);
                        break;

                default:
                        iha_bad_seq(sc);
                        return (-1);
                }
        }
}

/*
 * iha_state_8 - reset the active device and all busy SCBs using it
 */
static int
iha_state_8(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;
        int i;
        uint8_t tar;

        if (sc->sc_phase == PHASE_MSG_OUT) {
                bus_space_write_1(iot, ioh, TUL_SFIFO, MSG_BUS_DEV_RESET);

                scb = sc->sc_actscb;

                /* This SCB finished correctly -- resetting the device */
                iha_append_done_scb(sc, scb, HOST_OK);

                iha_reset_tcs(scb->tcs, sc->sc_sconf1);

                tar = scb->target;
                for (i = 0, scb = sc->sc_scb; i < IHA_MAX_SCB; i++, scb++)
                        if (scb->target == tar)
                                switch (scb->status) {
                                case STATUS_BUSY:
                                        iha_append_done_scb(sc,
                                            scb, HOST_DEV_RST);
                                        break;

                                case STATUS_SELECT:
                                        iha_push_pend_scb(sc, scb);
                                        break;

                                default:
                                        break;
                                }

                sc->sc_flags |= FLAG_EXPECT_DISC;

                if (iha_wait(sc, XF_FIFO_OUT) == -1)
                        return (-1);
        }

        iha_bad_seq(sc);
        return (-1);
}

/*
 * iha_xfer_data - initiate the DMA xfer of the data
 */
static int
iha_xfer_data(struct iha_softc *sc, struct iha_scb *scb, int direction)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        uint32_t xferlen;
        uint8_t xfercmd;

        if ((scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) != direction)
                return (6); /* wrong direction, abandon I/O */

        bus_space_write_4(iot, ioh, TUL_STCNT0, scb->buflen);

        xfercmd = STRXFR;
        if (direction == FLAG_DATAIN)
                xfercmd |= XDIR;

        if (scb->flags & FLAG_SG) {
                xferlen = scb->sg_size * sizeof(struct iha_sg_element);
                xfercmd |= SGXFR;
        } else
                xferlen = scb->buflen;

        bus_space_write_4(iot, ioh, TUL_DXC,  xferlen);
        bus_space_write_4(iot, ioh, TUL_DXPA, scb->bufaddr);
        bus_space_write_1(iot, ioh, TUL_DCMD, xfercmd);

        bus_space_write_1(iot, ioh, TUL_SCMD,
            (direction == FLAG_DATAIN) ? XF_DMA_IN : XF_DMA_OUT);

        scb->nextstat = 5;

        return (0);
}

static int
iha_xpad_in(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;

        if ((scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) != 0)
                scb->ha_stat = HOST_DO_DU;

        for (;;) {
                if ((scb->tcs->syncm & PERIOD_WIDE_SCSI) != 0)
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 2);
                else
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 1);

                switch (iha_wait(sc, XF_FIFO_IN)) {
                case -1:
                        return (-1);

                case PHASE_DATA_IN:
                        (void)bus_space_read_1(iot, ioh, TUL_SFIFO);
                        break;

                default:
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        return (6);
                }
        }
}

static int
iha_xpad_out(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb = sc->sc_actscb;

        if ((scb->flags & (FLAG_DATAIN | FLAG_DATAOUT)) != 0)
                scb->ha_stat = HOST_DO_DU;

        for (;;) {
                if ((scb->tcs->syncm & PERIOD_WIDE_SCSI) != 0)
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 2);
                else
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 1);

                bus_space_write_1(iot, ioh, TUL_SFIFO, 0);

                switch (iha_wait(sc, XF_FIFO_OUT)) {
                case -1:
                        return (-1);

                case PHASE_DATA_OUT:
                        break;

                default:
                        /* Disable wide CPU to allow read 16 bits */
                        bus_space_write_1(iot, ioh, TUL_SCTRL1, EHRSL);
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        return (6);
                }
        }
}

static int
iha_status_msg(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;
        uint8_t msg;
        int phase;

        if ((phase = iha_wait(sc, CMD_COMP)) == -1)
                return (-1);

        scb = sc->sc_actscb;

        scb->ta_stat = bus_space_read_1(iot, ioh, TUL_SFIFO);

        if (phase == PHASE_MSG_OUT) {
                if ((sc->sc_status0 & SPERR) == 0)
                        bus_space_write_1(iot, ioh, TUL_SFIFO, MSG_NOOP);
                else
                        bus_space_write_1(iot, ioh, TUL_SFIFO,
                            MSG_PARITY_ERROR);

                return (iha_wait(sc, XF_FIFO_OUT));

        } else if (phase == PHASE_MSG_IN) {
                msg = bus_space_read_1(iot, ioh, TUL_SFIFO);

                if ((sc->sc_status0 & SPERR) != 0)
                        switch (iha_wait(sc, MSG_ACCEPT)) {
                        case -1:
                                return (-1);
                        case PHASE_MSG_OUT:
                                bus_space_write_1(iot, ioh, TUL_SFIFO,
                                    MSG_PARITY_ERROR);
                                return (iha_wait(sc, XF_FIFO_OUT));
                        default:
                                iha_bad_seq(sc);
                                return (-1);
                        }

                if (msg == MSG_CMDCOMPLETE) {
                        if ((scb->ta_stat &
                            (SCSI_INTERM | SCSI_BUSY)) == SCSI_INTERM) {
                                iha_bad_seq(sc);
                                return (-1);
                        }
                        sc->sc_flags |= FLAG_EXPECT_DONE_DISC;
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        return (iha_wait(sc, MSG_ACCEPT));
                }

                if ((msg == MSG_LINK_CMD_COMPLETE)
                    || (msg == MSG_LINK_CMD_COMPLETEF)) {
                        if ((scb->ta_stat &
                            (SCSI_INTERM | SCSI_BUSY)) == SCSI_INTERM)
                                return (iha_wait(sc, MSG_ACCEPT));
                }
        }

        iha_bad_seq(sc);
        return (-1);
}

/*
 * iha_busfree - SCSI bus free detected as a result of a TIMEOUT or
 *               DISCONNECT interrupt. Reset the tulip FIFO and
 *               SCONFIG0 and enable hardware reselect. Move any active
 *               SCB to sc_donescb list. Return an appropriate host status
 *               if an I/O was active.
 */
static void
iha_busfree(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;

        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
        bus_space_write_1(iot, ioh, TUL_SCONFIG0, SCONFIG0DEFAULT);
        bus_space_write_1(iot, ioh, TUL_SCTRL1, EHRSL);

        scb = sc->sc_actscb;

        if (scb != NULL) {
                if (scb->status == STATUS_SELECT)
                        /* selection timeout   */
                        iha_append_done_scb(sc, scb, HOST_SEL_TOUT);
                else
                        /* Unexpected bus free */
                        iha_append_done_scb(sc, scb, HOST_BAD_PHAS);
        }
}

/*
 * iha_resel - handle a detected SCSI bus reselection request.
 */
static int
iha_resel(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct iha_scb *scb;
        struct tcs *tcs;
        uint8_t tag, target, lun, msg, abortmsg;

        if (sc->sc_actscb != NULL) {
                if (sc->sc_actscb->status == STATUS_SELECT)
                        iha_push_pend_scb(sc, sc->sc_actscb);
                sc->sc_actscb = NULL;
        }

        target = bus_space_read_1(iot, ioh, TUL_SBID);
        lun = bus_space_read_1(iot, ioh, TUL_SALVC) & IHA_MSG_IDENTIFY_LUNMASK;

        tcs = &sc->sc_tcs[target];

        bus_space_write_1(iot, ioh, TUL_SCONFIG0, tcs->sconfig0);
        bus_space_write_1(iot, ioh, TUL_SYNCM, tcs->syncm);

        abortmsg = MSG_ABORT; /* until a valid tag has been obtained */

        if (tcs->ntagscb != NULL)
                /* There is a non-tagged I/O active on the target */
                scb = tcs->ntagscb;

        else {
                /*
                 * Since there is no active non-tagged operation
                 * read the tag type, the tag itself, and find
                 * the appropriate scb by indexing sc_scb with
                 * the tag.
                 */

                switch (iha_wait(sc, MSG_ACCEPT)) {
                case -1:
                        return (-1);
                case PHASE_MSG_IN:
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 1);
                        if ((iha_wait(sc, XF_FIFO_IN)) == -1)
                                return (-1);
                        break;
                default:
                        goto abort;
                }

                msg = bus_space_read_1(iot, ioh, TUL_SFIFO); /* Read Tag Msg */

                if ((msg < MSG_SIMPLE_Q_TAG) || (msg > MSG_ORDERED_Q_TAG))
                        goto abort;

                switch (iha_wait(sc, MSG_ACCEPT)) {
                case -1:
                        return (-1);
                case PHASE_MSG_IN:
                        bus_space_write_4(iot, ioh, TUL_STCNT0, 1);
                        if ((iha_wait(sc, XF_FIFO_IN)) == -1)
                                return (-1);
                        break;
                default:
                        goto abort;
                }

                tag  = bus_space_read_1(iot, ioh, TUL_SFIFO); /* Read Tag ID */
                scb = &sc->sc_scb[tag];

                abortmsg = MSG_ABORT_TAG; /* Now that we have valid tag! */
        }

        if ((scb->target != target)
            || (scb->lun != lun)
            || (scb->status != STATUS_BUSY)) {
 abort:
                iha_msgout_abort(sc, abortmsg);
                return (-1);
        }

        sc->sc_actscb = scb;

        if (iha_wait(sc, MSG_ACCEPT) == -1)
                return (-1);

        return (iha_next_state(sc));
}

static int
iha_msgin(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int flags;
        int phase;
        uint8_t msg;

        for (;;) {
                if ((bus_space_read_1(iot, ioh, TUL_SFIFOCNT) & FIFOC) > 0)
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);

                bus_space_write_4(iot, ioh, TUL_STCNT0, 1);

                phase = iha_wait(sc, XF_FIFO_IN);
                msg = bus_space_read_1(iot, ioh, TUL_SFIFO);

                switch (msg) {
                case MSG_DISCONNECT:
                        sc->sc_flags |= FLAG_EXPECT_DISC;
                        if (iha_wait(sc, MSG_ACCEPT) != -1)
                                iha_bad_seq(sc);
                        phase = -1;
                        break;
                case MSG_SAVEDATAPOINTER:
                case MSG_RESTOREPOINTERS:
                case MSG_NOOP:
                        phase = iha_wait(sc, MSG_ACCEPT);
                        break;
                case MSG_MESSAGE_REJECT:
                        /* XXX - need to clear FIFO like other 'Clear ATN'?*/
                        iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);
                        flags = sc->sc_actscb->tcs->flags;
                        if ((flags & FLAG_NO_NEG_SYNC) == 0)
                                iha_set_ssig(sc, REQ | BSY | SEL, ATN);
                        phase = iha_wait(sc, MSG_ACCEPT);
                        break;
                case MSG_EXTENDED:
                        phase = iha_msgin_extended(sc);
                        break;
                case MSG_IGN_WIDE_RESIDUE:
                        phase = iha_msgin_ignore_wid_resid(sc);
                        break;
                case MSG_CMDCOMPLETE:
                        sc->sc_flags |= FLAG_EXPECT_DONE_DISC;
                        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
                        phase = iha_wait(sc, MSG_ACCEPT);
                        if (phase != -1) {
                                iha_bad_seq(sc);
                                return (-1);
                        }
                        break;
                default:
                        printf("[debug] iha_msgin: bad msg type: %d\n", msg);
                        phase = iha_msgout_reject(sc);
                        break;
                }

                if (phase != PHASE_MSG_IN)
                        return (phase);
        }
        /* NOTREACHED */
}

static int
iha_msgin_extended(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int flags, i, phase, msglen, msgcode;

        /*
         * XXX - can we just stop reading and reject, or do we have to
         *       read all input, discarding the excess, and then reject
         */
        for (i = 0; i < IHA_MAX_EXTENDED_MSG; i++) {
                phase = iha_wait(sc, MSG_ACCEPT);

                if (phase != PHASE_MSG_IN)
                        return (phase);

                bus_space_write_4(iot, ioh, TUL_STCNT0, 1);

                if (iha_wait(sc, XF_FIFO_IN) == -1)
                        return (-1);

                sc->sc_msg[i] = bus_space_read_1(iot, ioh, TUL_SFIFO);

                if (sc->sc_msg[0] == i)
                        break;
        }

        msglen  = sc->sc_msg[0];
        msgcode = sc->sc_msg[1];

        if ((msglen == MSG_EXT_SDTR_LEN) && (msgcode == MSG_EXT_SDTR)) {
                if (iha_msgin_sdtr(sc) == 0) {
                        iha_sync_done(sc);
                        return (iha_wait(sc, MSG_ACCEPT));
                }

                iha_set_ssig(sc, REQ | BSY | SEL, ATN);

                phase = iha_wait(sc, MSG_ACCEPT);
                if (phase != PHASE_MSG_OUT)
                        return (phase);

                /* Clear FIFO for important message - final SYNC offer */
                bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);

                iha_sync_done(sc); /* This is our final offer */

        } else if ((msglen == MSG_EXT_WDTR_LEN) && (msgcode == MSG_EXT_WDTR)) {

                flags = sc->sc_actscb->tcs->flags;

                if ((flags & FLAG_NO_WIDE) != 0)
                        /* Offer 8bit xfers only */
                        sc->sc_msg[2] = MSG_EXT_WDTR_BUS_8_BIT;

                else if (sc->sc_msg[2] > MSG_EXT_WDTR_BUS_32_BIT)
                        /* BAD MSG */
                        return (iha_msgout_reject(sc));

                else if (sc->sc_msg[2] == MSG_EXT_WDTR_BUS_32_BIT)
                        /* Offer 16bit instead */
                        sc->sc_msg[2] = MSG_EXT_WDTR_BUS_16_BIT;

                else {
                        iha_wide_done(sc);
                        if ((flags & FLAG_NO_NEG_SYNC) == 0)
                                iha_set_ssig(sc, REQ | BSY | SEL, ATN);
                        return (iha_wait(sc, MSG_ACCEPT));
                }

                iha_set_ssig(sc, REQ | BSY | SEL, ATN);

                phase = iha_wait(sc, MSG_ACCEPT);
                if (phase != PHASE_MSG_OUT)
                        return (phase);
        } else
                return (iha_msgout_reject(sc));

        return (iha_msgout_extended(sc));
}

/*
 * iha_msgin_sdtr - check SDTR msg in sc_msg. If the offer is
 *                  acceptable leave sc_msg as is and return 0.
 *                  If the negotiation must continue, modify sc_msg
 *                  as needed and return 1. Else return 0.
 */
static int
iha_msgin_sdtr(struct iha_softc *sc)
{
        int flags;
        int newoffer;
        uint8_t default_period;

        flags = sc->sc_actscb->tcs->flags;

        default_period = iha_rate_tbl[flags & FLAG_SCSI_RATE];

        if (sc->sc_msg[3] == 0)
                /* target offered async only. Accept it. */
                return (0);

        newoffer = 0;

        if ((flags & FLAG_NO_SYNC) != 0) {
                sc->sc_msg[3] = 0;
                newoffer = 1;
        }

        if (sc->sc_msg[3] > IHA_MAX_OFFSET) {
                sc->sc_msg[3] = IHA_MAX_OFFSET;
                newoffer = 1;
        }

        if (sc->sc_msg[2] < default_period) {
                sc->sc_msg[2] = default_period;
                newoffer = 1;
        }

        if (sc->sc_msg[2] > IHA_MAX_PERIOD) {
                /* Use async */
                sc->sc_msg[3] = 0;
                newoffer = 1;
        }

        return (newoffer);
}

static int
iha_msgin_ignore_wid_resid(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int phase;

        phase = iha_wait(sc, MSG_ACCEPT);

        if (phase == PHASE_MSG_IN) {
                phase = iha_wait(sc, XF_FIFO_IN);

                if (phase != -1) {
                        bus_space_write_1(iot, ioh, TUL_SFIFO, 0);
                        (void)bus_space_read_1(iot, ioh, TUL_SFIFO);
                        (void)bus_space_read_1(iot, ioh, TUL_SFIFO);

                        phase = iha_wait(sc, MSG_ACCEPT);
                }
        }

        return (phase);
}

static int
iha_msgout(struct iha_softc *sc, uint8_t msg)
{

        bus_space_write_1(sc->sc_iot, sc->sc_ioh, TUL_SFIFO, msg);

        return (iha_wait(sc, XF_FIFO_OUT));
}

static void
iha_msgout_abort(struct iha_softc *sc, uint8_t aborttype)
{

        iha_set_ssig(sc, REQ | BSY | SEL, ATN);

        switch (iha_wait(sc, MSG_ACCEPT)) {
        case -1:
                break;

        case PHASE_MSG_OUT:
                sc->sc_flags |= FLAG_EXPECT_DISC;
                if (iha_msgout(sc, aborttype) != -1)
                        iha_bad_seq(sc);
                break;

        default:
                iha_bad_seq(sc);
                break;
        }
}

static int
iha_msgout_reject(struct iha_softc *sc)
{

        iha_set_ssig(sc, REQ | BSY | SEL, ATN);

        if (iha_wait(sc, MSG_ACCEPT) == PHASE_MSG_OUT)
                return (iha_msgout(sc, MSG_MESSAGE_REJECT));

        return (-1);
}

static int
iha_msgout_extended(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int phase;

        bus_space_write_1(iot, ioh, TUL_SFIFO, MSG_EXTENDED);

        bus_space_write_multi_1(iot, ioh, TUL_SFIFO,
            sc->sc_msg, sc->sc_msg[0] + 1);

        phase = iha_wait(sc, XF_FIFO_OUT);

        bus_space_write_1(iot, ioh, TUL_SCTRL0, RSFIFO);
        iha_set_ssig(sc, REQ | BSY | SEL | ATN, 0);

        return (phase);
}

static int
iha_msgout_wdtr(struct iha_softc *sc)
{

        sc->sc_actscb->tcs->flags |= FLAG_WIDE_DONE;

        sc->sc_msg[0] = MSG_EXT_WDTR_LEN;
        sc->sc_msg[1] = MSG_EXT_WDTR;
        sc->sc_msg[2] = MSG_EXT_WDTR_BUS_16_BIT;

        return (iha_msgout_extended(sc));
}

static int
iha_msgout_sdtr(struct iha_softc *sc)
{
        struct tcs *tcs = sc->sc_actscb->tcs;

        tcs->flags |= FLAG_SYNC_DONE;

        sc->sc_msg[0] = MSG_EXT_SDTR_LEN;
        sc->sc_msg[1] = MSG_EXT_SDTR;
        sc->sc_msg[2] = iha_rate_tbl[tcs->flags & FLAG_SCSI_RATE];
        sc->sc_msg[3] = IHA_MAX_OFFSET; /* REQ/ACK */

        return (iha_msgout_extended(sc));
}

static void
iha_wide_done(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct tcs *tcs = sc->sc_actscb->tcs;

        tcs->syncm = 0;
        tcs->period = 0;
        tcs->offset = 0;

        if (sc->sc_msg[2] != 0)
                tcs->syncm |= PERIOD_WIDE_SCSI;

        tcs->sconfig0 &= ~ALTPD;
        tcs->flags &= ~FLAG_SYNC_DONE;
        tcs->flags |=  FLAG_WIDE_DONE;

        iha_update_xfer_mode(sc, sc->sc_actscb->target);

        bus_space_write_1(iot, ioh, TUL_SCONFIG0, tcs->sconfig0);
        bus_space_write_1(iot, ioh, TUL_SYNCM, tcs->syncm);
}

static void
iha_sync_done(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        struct tcs *tcs = sc->sc_actscb->tcs;
        int i;

        tcs->period = sc->sc_msg[2];
        tcs->offset = sc->sc_msg[3];
        if (tcs->offset != 0) {
                tcs->syncm |= tcs->offset;

                /* pick the highest possible rate */
                for (i = 0; i < sizeof(iha_rate_tbl); i++)
                        if (iha_rate_tbl[i] >= tcs->period)
                                break;

                tcs->syncm |= (i << 4);
                tcs->sconfig0 |= ALTPD;
        }

        tcs->flags |= FLAG_SYNC_DONE;

        iha_update_xfer_mode(sc, sc->sc_actscb->target);

        bus_space_write_1(iot, ioh, TUL_SCONFIG0, tcs->sconfig0);
        bus_space_write_1(iot, ioh, TUL_SYNCM, tcs->syncm);
}

/*
 * iha_bad_seq - a SCSI bus phase was encountered out of the
 *               correct/expected sequence. Reset the SCSI bus.
 */
static void
iha_bad_seq(struct iha_softc *sc)
{
        struct iha_scb *scb = sc->sc_actscb;

        if (scb != NULL)
                iha_append_done_scb(sc, scb, HOST_BAD_PHAS);

        iha_reset_scsi_bus(sc);
        iha_reset_chip(sc);
}

/*
 * iha_read_eeprom - read Serial EEPROM value & set to defaults
 *                   if required. XXX - Writing does NOT work!
 */
static void
iha_read_eeprom(struct iha_softc *sc, struct iha_eeprom *eeprom)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        uint16_t *tbuf = (uint16_t *)eeprom;
        uint8_t gctrl;

        /* Enable EEProm programming */
        gctrl = bus_space_read_1(iot, ioh, TUL_GCTRL0) | EEPRG;
        bus_space_write_1(iot, ioh, TUL_GCTRL0, gctrl);

        /* Read EEProm */
        if (iha_se2_rd_all(sc, tbuf) == 0)
                panic("%s: cannot read EEPROM", device_xname(sc->sc_dev));

        /* Disable EEProm programming */
        gctrl = bus_space_read_1(iot, ioh, TUL_GCTRL0) & ~EEPRG;
        bus_space_write_1(iot, ioh, TUL_GCTRL0, gctrl);
}

#ifdef notused
/*
 * iha_se2_update_all - Update SCSI H/A configuration parameters from
 *                      serial EEPROM Setup default pattern. Only
 *                      change those values different from the values
 *                      in iha_eeprom.
 */
static void
iha_se2_update_all(struct iha_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        uint16_t *np;
        uint32_t chksum;
        int i;

        /* Enable erase/write state of EEPROM */
        iha_se2_instr(sc, ENABLE_ERASE);
        bus_space_write_1(iot, ioh, TUL_NVRAM, 0);
        EEP_WAIT();

        np = (uint16_t *)&eeprom_default;

        for (i = 0, chksum = 0; i < EEPROM_SIZE - 1; i++) {
                iha_se2_wr(sc, i, *np);
                chksum += *np++;
        }

        chksum &= 0x0000ffff;
        iha_se2_wr(sc, 31, chksum);

        /* Disable erase/write state of EEPROM */
        iha_se2_instr(sc, 0);
        bus_space_write_1(iot, ioh, TUL_NVRAM, 0);
        EEP_WAIT();
}

/*
 * iha_se2_wr - write the given 16 bit value into the Serial EEPROM
 *              at the specified offset
 */
static void
iha_se2_wr(struct iha_softc *sc, int addr, uint16_t writeword)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int i, bit;

        /* send 'WRITE' Instruction == address | WRITE bit */
        iha_se2_instr(sc, addr | WRITE);

        for (i = 16; i > 0; i--) {
                if (writeword & (1 << (i - 1)))
                        bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS | NVRDO);
                else
                        bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
                EEP_WAIT();
                bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS | NVRCK);
                EEP_WAIT();
        }

        bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
        EEP_WAIT();
        bus_space_write_1(iot, ioh, TUL_NVRAM, 0);
        EEP_WAIT();
        bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
        EEP_WAIT();

        for (;;) {
                bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS | NVRCK);
                EEP_WAIT();
                bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
                EEP_WAIT();
                bit = bus_space_read_1(iot, ioh, TUL_NVRAM) & NVRDI;
                EEP_WAIT();
                if (bit != 0)
                        break; /* write complete */
        }

        bus_space_write_1(iot, ioh, TUL_NVRAM, 0);
}
#endif

/*
 * iha_se2_rd - read & return the 16 bit value at the specified
 *              offset in the Serial E2PROM
 *
 */
static uint16_t
iha_se2_rd(struct iha_softc *sc, int addr)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int i, bit;
        uint16_t readword;

        /* Send 'READ' instruction == address | READ bit */
        iha_se2_instr(sc, addr | READ);

        readword = 0;
        for (i = 16; i > 0; i--) {
                bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS | NVRCK);
                EEP_WAIT();
                bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
                EEP_WAIT();
                /* sample data after the following edge of clock     */
                bit = bus_space_read_1(iot, ioh, TUL_NVRAM) & NVRDI ? 1 : 0;
                EEP_WAIT();

                readword |= bit << (i - 1);
        }

        bus_space_write_1(iot, ioh, TUL_NVRAM, 0);

        return (readword);
}

/*
 * iha_se2_rd_all - Read SCSI H/A config parameters from serial EEPROM
 */
static int
iha_se2_rd_all(struct iha_softc *sc, uint16_t *tbuf)
{
        struct iha_eeprom *eeprom = (struct iha_eeprom *)tbuf;
        uint32_t chksum;
        int i;

        for (i = 0, chksum = 0; i < EEPROM_SIZE - 1; i++) {
                *tbuf = iha_se2_rd(sc, i);
                chksum += *tbuf++;
        }
        *tbuf = iha_se2_rd(sc, 31); /* read checksum from EEPROM */

        chksum &= 0x0000ffff; /* lower 16 bits */

        return (eeprom->signature == EEP_SIGNATURE) &&
            (eeprom->checksum == chksum);
}

/*
 * iha_se2_instr - write an octet to serial E2PROM one bit at a time
 */
static void
iha_se2_instr(struct iha_softc *sc, int instr)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        int b, i;

        b = NVRCS | NVRDO; /* Write the start bit (== 1) */

        bus_space_write_1(iot, ioh, TUL_NVRAM, b);
        EEP_WAIT();
        bus_space_write_1(iot, ioh, TUL_NVRAM, b | NVRCK);
        EEP_WAIT();

        for (i = 8; i > 0; i--) {
                if (instr & (1 << (i - 1)))
                        b = NVRCS | NVRDO; /* Write a 1 bit */
                else
                        b = NVRCS;         /* Write a 0 bit */

                bus_space_write_1(iot, ioh, TUL_NVRAM, b);
                EEP_WAIT();
                bus_space_write_1(iot, ioh, TUL_NVRAM, b | NVRCK);
                EEP_WAIT();
        }

        bus_space_write_1(iot, ioh, TUL_NVRAM, NVRCS);
}