/*      $NetBSD: bha.c,v 1.80 2022/09/25 18:43:32 thorpej Exp $ */

/*-
* Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
* Simulation Facility, NASA Ames Research Center.
*
* 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* Originally written by Julian Elischer ([email protected])
* for TRW Financial Systems for use under the MACH(2.5) operating system.
*
* TRW Financial Systems, in accordance with their agreement with Carnegie
* Mellon University, makes this software available to CMU to distribute
* or use in any manner that they see fit as long as this message is kept with
* the software. For this reason TFS also grants any other persons or
* organisations permission to use or modify this software.
*
* TFS supplies this software to be publicly redistributed
* on the understanding that TFS is not responsible for the correct
* functioning of this software in any circumstances.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bha.c,v 1.80 2022/09/25 18:43:32 thorpej Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <sys/proc.h>

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

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

#include <dev/ic/bhareg.h>
#include <dev/ic/bhavar.h>

#ifndef DDB
#define Debugger() panic("should call debugger here (bha.c)")
#endif /* ! DDB */

#define BHA_MAXXFER     ((BHA_NSEG - 1) << PGSHIFT)

#ifdef BHADEBUG
int     bha_debug = 0;
#endif /* BHADEBUG */

static int      bha_cmd(bus_space_tag_t, bus_space_handle_t, const char *, int,
                       u_char *, int, u_char *);

static void     bha_scsipi_request(struct scsipi_channel *,
                                  scsipi_adapter_req_t, void *);
static void     bha_minphys(struct buf *);

static void     bha_get_xfer_mode(struct bha_softc *,
                                 struct scsipi_xfer_mode *);

static void     bha_done(struct bha_softc *, struct bha_ccb *);
static int      bha_poll(struct bha_softc *, struct scsipi_xfer *, int);
static void     bha_timeout(void *arg);

static int      bha_init(struct bha_softc *);

static int      bha_create_mailbox(struct bha_softc *);
static void     bha_collect_mbo(struct bha_softc *);

static void     bha_queue_ccb(struct bha_softc *, struct bha_ccb *);
static void     bha_start_ccbs(struct bha_softc *);
static void     bha_finish_ccbs(struct bha_softc *);

static struct bha_ccb *bha_ccb_phys_kv(struct bha_softc *, bus_addr_t);
static void     bha_create_ccbs(struct bha_softc *, int);
static int      bha_init_ccb(struct bha_softc *, struct bha_ccb *);
static struct bha_ccb *bha_get_ccb(struct bha_softc *);
static void     bha_free_ccb(struct bha_softc *, struct bha_ccb *);

#define BHA_RESET_TIMEOUT       2000    /* time to wait for reset (mSec) */
#define BHA_ABORT_TIMEOUT       2000    /* time to wait for abort (mSec) */

/*
* Number of CCBs in an allocation group; must be computed at run-time.
*/
static int      bha_ccbs_per_group;

static inline struct bha_mbx_out *
bha_nextmbo(struct bha_softc *sc, struct bha_mbx_out *mbo)
{

       if (mbo == &sc->sc_mbo[sc->sc_mbox_count - 1])
               return (&sc->sc_mbo[0]);
       return (mbo + 1);
}

static inline struct bha_mbx_in *
bha_nextmbi(struct bha_softc *sc, struct bha_mbx_in *mbi)
{
       if (mbi == &sc->sc_mbi[sc->sc_mbox_count - 1])
               return (&sc->sc_mbi[0]);
       return (mbi + 1);
}

/*
* bha_attach:
*
*      Finish attaching a Buslogic controller, and configure children.
*/
void
bha_attach(struct bha_softc *sc)
{
       struct scsipi_adapter *adapt = &sc->sc_adapter;
       struct scsipi_channel *chan = &sc->sc_channel;
       int initial_ccbs;

       /*
        * Initialize the number of CCBs per group.
        */
       if (bha_ccbs_per_group == 0)
               bha_ccbs_per_group = BHA_CCBS_PER_GROUP;

       initial_ccbs = bha_info(sc);
       if (initial_ccbs == 0) {
               aprint_error_dev(sc->sc_dev, "unable to get adapter info\n");
               return;
       }

       /*
        * Fill in the scsipi_adapter.
        */
       memset(adapt, 0, sizeof(*adapt));
       adapt->adapt_dev = sc->sc_dev;
       adapt->adapt_nchannels = 1;
       /* adapt_openings initialized below */
       adapt->adapt_max_periph = sc->sc_mbox_count;
       adapt->adapt_request = bha_scsipi_request;
       adapt->adapt_minphys = bha_minphys;

       /*
        * Fill in the scsipi_channel.
        */
       memset(chan, 0, sizeof(*chan));
       chan->chan_adapter = adapt;
       chan->chan_bustype = &scsi_bustype;
       chan->chan_channel = 0;
       chan->chan_flags = SCSIPI_CHAN_CANGROW;
       chan->chan_ntargets = (sc->sc_flags & BHAF_WIDE) ? 16 : 8;
       chan->chan_nluns = (sc->sc_flags & BHAF_WIDE_LUN) ? 32 : 8;
       chan->chan_id = sc->sc_scsi_id;

       TAILQ_INIT(&sc->sc_free_ccb);
       TAILQ_INIT(&sc->sc_waiting_ccb);
       TAILQ_INIT(&sc->sc_allocating_ccbs);

       if (bha_create_mailbox(sc) != 0)
               return;

       bha_create_ccbs(sc, initial_ccbs);
       if (sc->sc_cur_ccbs < 2) {
               aprint_error_dev(sc->sc_dev, "not enough CCBs to run\n");
               return;
       }

       adapt->adapt_openings = sc->sc_cur_ccbs;

       if (bha_init(sc) != 0)
               return;

       (void) config_found(sc->sc_dev, &sc->sc_channel, scsiprint, CFARGS_NONE);
}

/*
* bha_intr:
*
*      Interrupt service routine.
*/
int
bha_intr(void *arg)
{
       struct bha_softc *sc = arg;
       bus_space_tag_t iot = sc->sc_iot;
       bus_space_handle_t ioh = sc->sc_ioh;
       u_char sts;

#ifdef BHADEBUG
       printf("%s: bha_intr ", device_xname(sc->sc_dev));
#endif /* BHADEBUG */

       /*
        * First acknowledge the interrupt, Then if it's not telling about
        * a completed operation just return.
        */
       sts = bus_space_read_1(iot, ioh, BHA_INTR_PORT);
       if ((sts & BHA_INTR_ANYINTR) == 0)
               return (0);
       bus_space_write_1(iot, ioh, BHA_CTRL_PORT, BHA_CTRL_IRST);

#ifdef BHADIAG
       /* Make sure we clear CCB_SENDING before finishing a CCB. */
       bha_collect_mbo(sc);
#endif

       /* Mail box out empty? */
       if (sts & BHA_INTR_MBOA) {
               struct bha_toggle toggle;

               toggle.cmd.opcode = BHA_MBO_INTR_EN;
               toggle.cmd.enable = 0;
               bha_cmd(iot, ioh, device_xname(sc->sc_dev),
                   sizeof(toggle.cmd), (u_char *)&toggle.cmd,
                   0, (u_char *)0);
               bha_start_ccbs(sc);
       }

       /* Mail box in full? */
       if (sts & BHA_INTR_MBIF)
               bha_finish_ccbs(sc);

       return (1);
}

/*****************************************************************************
* SCSI interface routines
*****************************************************************************/

/*
* bha_scsipi_request:
*
*      Perform a request for the SCSIPI layer.
*/
static void
bha_scsipi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
   void *arg)
{
       struct scsipi_adapter *adapt = chan->chan_adapter;
       struct bha_softc *sc = device_private(adapt->adapt_dev);
       struct scsipi_xfer *xs;
       struct scsipi_periph *periph;
       bus_dma_tag_t dmat = sc->sc_dmat;
       struct bha_ccb *ccb;
       int error, seg, flags, s;

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

               SC_DEBUG(periph, SCSIPI_DB2, ("bha_scsipi_request\n"));

               /* Get a CCB to use. */
               ccb = bha_get_ccb(sc);
#ifdef DIAGNOSTIC
               /*
                * This should never happen as we track the resources
                * in the mid-layer.
                */
               if (ccb == NULL) {
                       scsipi_printaddr(periph);
                       printf("unable to allocate ccb\n");
                       panic("bha_scsipi_request");
               }
#endif

               ccb->xs = xs;
               ccb->timeout = xs->timeout;

               /*
                * Put all the arguments for the xfer in the ccb
                */
               if (flags & XS_CTL_RESET) {
                       ccb->opcode = BHA_RESET_CCB;
                       ccb->scsi_cmd_length = 0;
               } else {
                       /* can't use S/G if zero length */
                       if (xs->cmdlen > sizeof(ccb->scsi_cmd)) {
                               printf("%s: cmdlen %d too large for CCB\n",
                                   device_xname(sc->sc_dev), xs->cmdlen);
                               xs->error = XS_DRIVER_STUFFUP;
                               goto out_bad;
                       }
                       ccb->opcode = (xs->datalen ? BHA_INIT_SCAT_GATH_CCB
                                                  : BHA_INITIATOR_CCB);
                       memcpy(&ccb->scsi_cmd, xs->cmd,
                           ccb->scsi_cmd_length = xs->cmdlen);
               }

               if (xs->datalen) {
                       /*
                        * Map the DMA transfer.
                        */
#ifdef TFS
                       if (flags & XS_CTL_DATA_UIO) {
                               error = bus_dmamap_load_uio(dmat,
                                   ccb->dmamap_xfer, (struct uio *)xs->data,
                                   ((flags & XS_CTL_NOSLEEP) ? BUS_DMA_NOWAIT :
                                    BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
                                    ((flags & XS_CTL_DATA_IN) ? BUS_DMA_READ :
                                     BUS_DMA_WRITE));
                       } else
#endif /* TFS */
                       {
                               error = bus_dmamap_load(dmat,
                                   ccb->dmamap_xfer, xs->data, xs->datalen,
                                   NULL,
                                   ((flags & XS_CTL_NOSLEEP) ? BUS_DMA_NOWAIT :
                                    BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
                                    ((flags & XS_CTL_DATA_IN) ? BUS_DMA_READ :
                                     BUS_DMA_WRITE));
                       }

                       switch (error) {
                       case 0:
                               break;

                       case ENOMEM:
                       case EAGAIN:
                               xs->error = XS_RESOURCE_SHORTAGE;
                               goto out_bad;

                       default:
                               xs->error = XS_DRIVER_STUFFUP;
                               aprint_error_dev(sc->sc_dev,
                                   "error %d loading DMA map\n", error);
out_bad:
                               bha_free_ccb(sc, ccb);
                               scsipi_done(xs);
                               return;
                       }

                       bus_dmamap_sync(dmat, ccb->dmamap_xfer, 0,
                           ccb->dmamap_xfer->dm_mapsize,
                           (flags & XS_CTL_DATA_IN) ? BUS_DMASYNC_PREREAD :
                           BUS_DMASYNC_PREWRITE);

                       /*
                        * Load the hardware scatter/gather map with the
                        * contents of the DMA map.
                        */
                       for (seg = 0; seg < ccb->dmamap_xfer->dm_nsegs; seg++) {
                               ltophys(ccb->dmamap_xfer->dm_segs[seg].ds_addr,
                                   ccb->scat_gath[seg].seg_addr);
                               ltophys(ccb->dmamap_xfer->dm_segs[seg].ds_len,
                                   ccb->scat_gath[seg].seg_len);
                       }

                       ltophys(ccb->hashkey + offsetof(struct bha_ccb,
                           scat_gath), ccb->data_addr);
                       ltophys(ccb->dmamap_xfer->dm_nsegs *
                           sizeof(struct bha_scat_gath), ccb->data_length);
               } else {
                       /*
                        * No data xfer, use non S/G values.
                        */
                       ltophys(0, ccb->data_addr);
                       ltophys(0, ccb->data_length);
               }

               if (XS_CTL_TAGTYPE(xs) != 0) {
                       ccb->tag_enable = 1;
                       ccb->tag_type = xs->xs_tag_type & 0x03;
               } else {
                       ccb->tag_enable = 0;
                       ccb->tag_type = 0;
               }

               ccb->data_out = 0;
               ccb->data_in = 0;
               ccb->target = periph->periph_target;
               ccb->lun = periph->periph_lun;
               ltophys(ccb->hashkey + offsetof(struct bha_ccb, scsi_sense),
                   ccb->sense_ptr);
               ccb->req_sense_length = sizeof(ccb->scsi_sense);
               ccb->host_stat = 0x00;
               ccb->target_stat = 0x00;
               ccb->link_id = 0;
               ltophys(0, ccb->link_addr);

               BHA_CCB_SYNC(sc, ccb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

               s = splbio();
               bha_queue_ccb(sc, ccb);
               splx(s);

               SC_DEBUG(periph, SCSIPI_DB3, ("cmd_sent\n"));
               if ((flags & XS_CTL_POLL) == 0)
                       return;

               /*
                * If we can't use interrupts, poll on completion
                */
               if (bha_poll(sc, xs, ccb->timeout)) {
                       bha_timeout(ccb);
                       if (bha_poll(sc, xs, ccb->timeout))
                               bha_timeout(ccb);
               }
               return;

       case ADAPTER_REQ_GROW_RESOURCES:
               if (sc->sc_cur_ccbs == sc->sc_max_ccbs) {
                       chan->chan_flags &= ~SCSIPI_CHAN_CANGROW;
                       return;
               }
               seg = sc->sc_cur_ccbs;
               bha_create_ccbs(sc, bha_ccbs_per_group);
               adapt->adapt_openings += sc->sc_cur_ccbs - seg;
               return;

       case ADAPTER_REQ_SET_XFER_MODE:
               /*
                * Can't really do this on the Buslogic.  It has its
                * own setup info.  But we do know how to query what
                * the settings are.
                */
               bha_get_xfer_mode(sc, (struct scsipi_xfer_mode *)arg);
               return;
       }
}

/*
* bha_minphys:
*
*      Limit a transfer to our maximum transfer size.
*/
void
bha_minphys(struct buf *bp)
{

       if (bp->b_bcount > BHA_MAXXFER)
               bp->b_bcount = BHA_MAXXFER;
       minphys(bp);
}

/*****************************************************************************
* SCSI job execution helper routines
*****************************************************************************/

/*
* bha_get_xfer_mode;
*
*      Negotiate the xfer mode for the specified periph, and report
*      back the mode to the midlayer.
*
*      NOTE: we must be called at splbio().
*/
static void
bha_get_xfer_mode(struct bha_softc *sc, struct scsipi_xfer_mode *xm)
{
       struct bha_setup hwsetup;
       struct bha_period hwperiod;
       struct bha_sync *bs;
       int toff = xm->xm_target & 7, tmask = (1 << toff);
       int wide, period, offset, rlen;

       /*
        * Issue an Inquire Setup Information.  We can extract
        * sync and wide information from here.
        */
       rlen = sizeof(hwsetup.reply) +
           ((sc->sc_flags & BHAF_WIDE) ? sizeof(hwsetup.reply_w) : 0);
       hwsetup.cmd.opcode = BHA_INQUIRE_SETUP;
       hwsetup.cmd.len = rlen;
       bha_cmd(sc->sc_iot, sc->sc_ioh, device_xname(sc->sc_dev),
           sizeof(hwsetup.cmd), (u_char *)&hwsetup.cmd,
           rlen, (u_char *)&hwsetup.reply);

       xm->xm_mode = 0;
       xm->xm_period = 0;
       xm->xm_offset = 0;

       /*
        * First check for wide.  On later boards, we can check
        * directly in the setup info if wide is currently active.
        *
        * On earlier boards, we have to make an educated guess.
        */
       if (sc->sc_flags & BHAF_WIDE) {
               if (strcmp(sc->sc_firmware, "5.06L") >= 0) {
                       if (xm->xm_target > 7) {
                               wide =
                                   hwsetup.reply_w.high_wide_active & tmask;
                       } else {
                               wide =
                                   hwsetup.reply_w.low_wide_active & tmask;
                       }
                       if (wide)
                               xm->xm_mode |= PERIPH_CAP_WIDE16;
               } else {
                       /* XXX Check `wide permitted' in the config info. */
                       xm->xm_mode |= PERIPH_CAP_WIDE16;
               }
       }

       /*
        * Now get basic sync info.
        */
       bs = (xm->xm_target > 7) ?
            &hwsetup.reply_w.sync_high[toff] :
            &hwsetup.reply.sync_low[toff];

       if (bs->valid) {
               xm->xm_mode |= PERIPH_CAP_SYNC;
               period = (bs->period * 50) + 20;
               offset = bs->offset;

               /*
                * On boards that can do Fast and Ultra, use the Inquire Period
                * command to get the period.
                */
               if (sc->sc_firmware[0] >= '3') {
                       rlen = sizeof(hwperiod.reply) +
                           ((sc->sc_flags & BHAF_WIDE) ?
                             sizeof(hwperiod.reply_w) : 0);
                       hwperiod.cmd.opcode = BHA_INQUIRE_PERIOD;
                       hwperiod.cmd.len = rlen;
                       bha_cmd(sc->sc_iot, sc->sc_ioh,
                           device_xname(sc->sc_dev), sizeof(hwperiod.cmd),
                           (u_char *)&hwperiod.cmd, rlen,
                           (u_char *)&hwperiod.reply);

                       if (xm->xm_target > 7)
                               period = hwperiod.reply_w.period[toff];
                       else
                               period = hwperiod.reply.period[toff];

                       period *= 10;
               }

               xm->xm_period =
                   scsipi_sync_period_to_factor(period * 100);
               xm->xm_offset = offset;
       }

       /*
        * Now check for tagged queueing support.
        *
        * XXX Check `tags permitted' in the config info.
        */
       if (sc->sc_flags & BHAF_TAGGED_QUEUEING)
               xm->xm_mode |= PERIPH_CAP_TQING;

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

/*
* bha_done:
*
*      A CCB has completed execution.  Pass the status back to the
*      upper layer.
*/
static void
bha_done(struct bha_softc *sc, struct bha_ccb *ccb)
{
       bus_dma_tag_t dmat = sc->sc_dmat;
       struct scsipi_xfer *xs = ccb->xs;

       SC_DEBUG(xs->xs_periph, SCSIPI_DB2, ("bha_done\n"));

#ifdef BHADIAG
       if (ccb->flags & CCB_SENDING) {
               printf("%s: exiting ccb still in transit!\n",
                   device_xname(sc->sc_dev));
               Debugger();
               return;
       }
#endif
       if ((ccb->flags & CCB_ALLOC) == 0) {
               aprint_error_dev(sc->sc_dev, "exiting ccb not allocated!\n");
               Debugger();
               return;
       }

       /*
        * If we were a data transfer, unload the map that described
        * the data buffer.
        */
       if (xs->datalen) {
               bus_dmamap_sync(dmat, ccb->dmamap_xfer, 0,
                   ccb->dmamap_xfer->dm_mapsize,
                   (xs->xs_control & XS_CTL_DATA_IN) ? BUS_DMASYNC_POSTREAD :
                   BUS_DMASYNC_POSTWRITE);
               bus_dmamap_unload(dmat, ccb->dmamap_xfer);
       }

       if (xs->error == XS_NOERROR) {
               if (ccb->host_stat != BHA_OK) {
                       switch (ccb->host_stat) {
                       case BHA_SEL_TIMEOUT:   /* No response */
                               xs->error = XS_SELTIMEOUT;
                               break;
                       default:        /* Other scsi protocol messes */
                               printf("%s: host_stat %x\n",
                                   device_xname(sc->sc_dev), ccb->host_stat);
                               xs->error = XS_DRIVER_STUFFUP;
                               break;
                       }
               } else if (ccb->target_stat != SCSI_OK) {
                       switch (ccb->target_stat) {
                       case SCSI_CHECK:
                               memcpy(&xs->sense.scsi_sense,
                                   &ccb->scsi_sense,
                                   sizeof(xs->sense.scsi_sense));
                               xs->error = XS_SENSE;
                               break;
                       case SCSI_BUSY:
                               xs->error = XS_BUSY;
                               break;
                       default:
                               printf("%s: target_stat %x\n",
                                   device_xname(sc->sc_dev), ccb->target_stat);
                               xs->error = XS_DRIVER_STUFFUP;
                               break;
                       }
               } else
                       xs->resid = 0;
       }

       bha_free_ccb(sc, ccb);
       scsipi_done(xs);
}

/*
* bha_poll:
*
*      Poll for completion of the specified job.
*/
static int
bha_poll(struct bha_softc *sc, struct scsipi_xfer *xs, int count)
{
       bus_space_tag_t iot = sc->sc_iot;
       bus_space_handle_t ioh = sc->sc_ioh;

       /* timeouts are in msec, so we loop in 1000 usec cycles */
       while (count) {
               /*
                * If we had interrupts enabled, would we
                * have got an interrupt?
                */
               if (bus_space_read_1(iot, ioh, BHA_INTR_PORT) &
                   BHA_INTR_ANYINTR)
                       bha_intr(sc);
               if (xs->xs_status & XS_STS_DONE)
                       return (0);
               delay(1000);    /* only happens in boot so ok */
               count--;
       }
       return (1);
}

/*
* bha_timeout:
*
*      CCB timeout handler.
*/
static void
bha_timeout(void *arg)
{
       struct bha_ccb *ccb = arg;
       struct scsipi_xfer *xs = ccb->xs;
       struct scsipi_periph *periph = xs->xs_periph;
       struct bha_softc *sc =
           device_private(periph->periph_channel->chan_adapter->adapt_dev);
       int s;

       scsipi_printaddr(periph);
       printf("timed out");

       s = splbio();

#ifdef BHADIAG
       /*
        * If the ccb's mbx is not free, then the board has gone Far East?
        */
       bha_collect_mbo(sc);
       if (ccb->flags & CCB_SENDING) {
               aprint_error_dev(sc->sc_dev, "not taking commands!\n");
               Debugger();
       }
#endif

       /*
        * If it has been through before, then
        * a previous abort has failed, don't
        * try abort again
        */
       if (ccb->flags & CCB_ABORT) {
               /* abort timed out */
               printf(" AGAIN\n");
               /* XXX Must reset! */
       } else {
               /* abort the operation that has timed out */
               printf("\n");
               ccb->xs->error = XS_TIMEOUT;
               ccb->timeout = BHA_ABORT_TIMEOUT;
               ccb->flags |= CCB_ABORT;
               bha_queue_ccb(sc, ccb);
       }

       splx(s);
}

/*****************************************************************************
* Misc. subroutines.
*****************************************************************************/

/*
* bha_cmd:
*
*      Send a command to the Buglogic controller.
*/
static int
bha_cmd(bus_space_tag_t iot, bus_space_handle_t ioh, const char *name,
   int icnt, u_char *ibuf, int ocnt, u_char *obuf)
{
       int i;
       int wait;
       u_char sts;
       u_char opcode = ibuf[0];

       /*
        * Calculate a reasonable timeout for the command.
        */
       switch (opcode) {
       case BHA_INQUIRE_DEVICES:
       case BHA_INQUIRE_DEVICES_2:
               wait = 90 * 20000;
               break;
       default:
               wait = 1 * 20000;
               break;
       }

       /*
        * Wait for the adapter to go idle, unless it's one of
        * the commands which don't need this
        */
       if (opcode != BHA_MBO_INTR_EN) {
               for (i = 20000; i; i--) {       /* 1 sec? */
                       sts = bus_space_read_1(iot, ioh, BHA_STAT_PORT);
                       if (sts & BHA_STAT_IDLE)
                               break;
                       delay(50);
               }
               if (!i) {
                       printf("%s: bha_cmd, host not idle(0x%x)\n",
                           name, sts);
                       return (1);
               }
       }

       /*
        * Now that it is idle, if we expect output, preflush the
        * queue feeding to us.
        */
       if (ocnt) {
               while ((bus_space_read_1(iot, ioh, BHA_STAT_PORT)) &
                   BHA_STAT_DF)
                       (void)bus_space_read_1(iot, ioh, BHA_DATA_PORT);
       }

       /*
        * Output the command and the number of arguments given
        * for each byte, first check the port is empty.
        */
       while (icnt--) {
               for (i = wait; i; i--) {
                       sts = bus_space_read_1(iot, ioh, BHA_STAT_PORT);
                       if (!(sts & BHA_STAT_CDF))
                               break;
                       delay(50);
               }
               if (!i) {
                       if (opcode != BHA_INQUIRE_REVISION)
                               printf("%s: bha_cmd, cmd/data port full\n",
                                   name);
                       goto bad;
               }
               bus_space_write_1(iot, ioh, BHA_CMD_PORT, *ibuf++);
       }

       /*
        * If we expect input, loop that many times, each time,
        * looking for the data register to have valid data
        */
       while (ocnt--) {
               for (i = wait; i; i--) {
                       sts = bus_space_read_1(iot, ioh, BHA_STAT_PORT);
                       if (sts & BHA_STAT_DF)
                               break;
                       delay(50);
               }
               if (!i) {
#ifdef BHADEBUG
                       if (opcode != BHA_INQUIRE_REVISION)
                               printf("%s: bha_cmd, cmd/data port empty %d\n",
                                   name, ocnt);
#endif /* BHADEBUG */
                       goto bad;
               }
               *obuf++ = bus_space_read_1(iot, ioh, BHA_DATA_PORT);
       }

       /*
        * Wait for the board to report a finished instruction.
        * We may get an extra interrupt for the HACC signal, but this is
        * unimportant.
        */
       if (opcode != BHA_MBO_INTR_EN && opcode != BHA_MODIFY_IOPORT) {
               for (i = 20000; i; i--) {       /* 1 sec? */
                       sts = bus_space_read_1(iot, ioh, BHA_INTR_PORT);
                       /* XXX Need to save this in the interrupt handler? */
                       if (sts & BHA_INTR_HACC)
                               break;
                       delay(50);
               }
               if (!i) {
                       printf("%s: bha_cmd, host not finished(0x%x)\n",
                           name, sts);
                       return (1);
               }
       }
       bus_space_write_1(iot, ioh, BHA_CTRL_PORT, BHA_CTRL_IRST);
       return (0);

bad:
       bus_space_write_1(iot, ioh, BHA_CTRL_PORT, BHA_CTRL_SRST);
       return (1);
}

/*
* bha_find:
*
*      Find the board.
*/
int
bha_find(bus_space_tag_t iot, bus_space_handle_t ioh)
{
       int i;
       u_char sts;
       struct bha_extended_inquire inquire;

       /* Check something is at the ports we need to access */
       sts = bus_space_read_1(iot, ioh, BHA_STAT_PORT);
       if (sts == 0xFF)
               return (0);

       /*
        * Reset board, If it doesn't respond, assume
        * that it's not there.. good for the probe
        */

       bus_space_write_1(iot, ioh, BHA_CTRL_PORT,
           BHA_CTRL_HRST | BHA_CTRL_SRST);

       delay(100);
       for (i = BHA_RESET_TIMEOUT; i; i--) {
               sts = bus_space_read_1(iot, ioh, BHA_STAT_PORT);
               if (sts == (BHA_STAT_IDLE | BHA_STAT_INIT))
                       break;
               delay(1000);
       }
       if (!i) {
#ifdef BHADEBUG
               if (bha_debug)
                       printf("bha_find: No answer from buslogic board\n");
#endif /* BHADEBUG */
               return (0);
       }

       /*
        * The BusLogic cards implement an Adaptec 1542 (aha)-compatible
        * interface. The native bha interface is not compatible with
        * an aha. 1542. We need to ensure that we never match an
        * Adaptec 1542. We must also avoid sending Adaptec-compatible
        * commands to a real bha, lest it go into 1542 emulation mode.
        * (On an indirect bus like ISA, we should always probe for BusLogic
        * interfaces before Adaptec interfaces).
        */

       /*
        * Make sure we don't match an AHA-1542A or AHA-1542B, by checking
        * for an extended-geometry register.  The 1542[AB] don't have one.
        */
       sts = bus_space_read_1(iot, ioh, BHA_EXTGEOM_PORT);
       if (sts == 0xFF)
               return (0);

       /*
        * Check that we actually know how to use this board.
        */
       delay(1000);
       inquire.cmd.opcode = BHA_INQUIRE_EXTENDED;
       inquire.cmd.len = sizeof(inquire.reply);
       i = bha_cmd(iot, ioh, "(bha_find)",
           sizeof(inquire.cmd), (u_char *)&inquire.cmd,
           sizeof(inquire.reply), (u_char *)&inquire.reply);

       /*
        * Some 1542Cs (CP, perhaps not CF, may depend on firmware rev)
        * have the extended-geometry register and also respond to
        * BHA_INQUIRE_EXTENDED.  Make sure we never match such cards,
        * by checking the size of the reply is what a BusLogic card returns.
        */
       if (i) {
#ifdef BHADEBUG
               printf("bha_find: board returned %d instead of %zu to %s\n",
                      i, sizeof(inquire.reply), "INQUIRE_EXTENDED");
#endif
               return (0);
       }

       /* OK, we know we've found a buslogic adaptor. */

       switch (inquire.reply.bus_type) {
       case BHA_BUS_TYPE_24BIT:
       case BHA_BUS_TYPE_32BIT:
               break;
       case BHA_BUS_TYPE_MCA:
               /* We don't grok MicroChannel (yet). */
               return (0);
       default:
               printf("bha_find: illegal bus type %c\n",
                   inquire.reply.bus_type);
               return (0);
       }

       return (1);
}


/*
* bha_inquire_config:
*
*      Determine irq/drq.
*/
int
bha_inquire_config(bus_space_tag_t iot, bus_space_handle_t ioh,
           struct bha_probe_data *sc)
{
       int irq, drq;
       struct bha_config config;

       /*
        * Assume we have a board at this stage setup DMA channel from
        * jumpers and save int level
        */
       delay(1000);
       config.cmd.opcode = BHA_INQUIRE_CONFIG;
       bha_cmd(iot, ioh, "(bha_inquire_config)",
           sizeof(config.cmd), (u_char *)&config.cmd,
           sizeof(config.reply), (u_char *)&config.reply);
       switch (config.reply.chan) {
       case EISADMA:
               drq = -1;
               break;
       case CHAN0:
               drq = 0;
               break;
       case CHAN5:
               drq = 5;
               break;
       case CHAN6:
               drq = 6;
               break;
       case CHAN7:
               drq = 7;
               break;
       default:
               printf("bha: illegal drq setting %x\n",
                   config.reply.chan);
               return (0);
       }

       switch (config.reply.intr) {
       case INT9:
               irq = 9;
               break;
       case INT10:
               irq = 10;
               break;
       case INT11:
               irq = 11;
               break;
       case INT12:
               irq = 12;
               break;
       case INT14:
               irq = 14;
               break;
       case INT15:
               irq = 15;
               break;
       default:
               printf("bha: illegal irq setting %x\n",
                   config.reply.intr);
               return (0);
       }

       /* if we want to fill in softc, do so now */
       if (sc != NULL) {
               sc->sc_irq = irq;
               sc->sc_drq = drq;
       }

       return (1);
}

int
bha_probe_inquiry(bus_space_tag_t iot, bus_space_handle_t ioh,
   struct bha_probe_data *bpd)
{
       return bha_find(iot, ioh) && bha_inquire_config(iot, ioh, bpd);
}

/*
* bha_disable_isacompat:
*
*      Disable the ISA-compatibility ioports on PCI bha devices,
*      to ensure they're not autoconfigured a second time as an ISA bha.
*/
int
bha_disable_isacompat(struct bha_softc *sc)
{
       struct bha_isadisable isa_disable;

       isa_disable.cmd.opcode = BHA_MODIFY_IOPORT;
       isa_disable.cmd.modifier = BHA_IOMODIFY_DISABLE1;
       bha_cmd(sc->sc_iot, sc->sc_ioh, device_xname(sc->sc_dev),
           sizeof(isa_disable.cmd), (u_char*)&isa_disable.cmd,
           0, (u_char *)0);
       return (0);
}

/*
* bha_info:
*
*      Get information about the board, and report it.  We
*      return the initial number of CCBs, 0 if we failed.
*/
int
bha_info(struct bha_softc *sc)
{
       bus_space_tag_t iot = sc->sc_iot;
       bus_space_handle_t ioh = sc->sc_ioh;
       struct bha_extended_inquire inquire;
       struct bha_config config;
       struct bha_devices devices;
       struct bha_setup setup;
       struct bha_model model;
       struct bha_revision revision;
       struct bha_digit digit;
       int i, j, initial_ccbs, rlen;
       const char *name = device_xname(sc->sc_dev);
       char *p;

       /*
        * Fetch the extended inquire information.
        */
       inquire.cmd.opcode = BHA_INQUIRE_EXTENDED;
       inquire.cmd.len = sizeof(inquire.reply);
       bha_cmd(iot, ioh, name,
           sizeof(inquire.cmd), (u_char *)&inquire.cmd,
           sizeof(inquire.reply), (u_char *)&inquire.reply);

       /*
        * Fetch the configuration information.
        */
       config.cmd.opcode = BHA_INQUIRE_CONFIG;
       bha_cmd(iot, ioh, name,
           sizeof(config.cmd), (u_char *)&config.cmd,
           sizeof(config.reply), (u_char *)&config.reply);

       sc->sc_scsi_id = config.reply.scsi_dev;

       /*
        * Get the firmware revision.
        */
       p = sc->sc_firmware;
       revision.cmd.opcode = BHA_INQUIRE_REVISION;
       bha_cmd(iot, ioh, name,
           sizeof(revision.cmd), (u_char *)&revision.cmd,
           sizeof(revision.reply), (u_char *)&revision.reply);
       *p++ = revision.reply.firm_revision;
       *p++ = '.';
       *p++ = revision.reply.firm_version;
       digit.cmd.opcode = BHA_INQUIRE_REVISION_3;
       bha_cmd(iot, ioh, name,
           sizeof(digit.cmd), (u_char *)&digit.cmd,
           sizeof(digit.reply), (u_char *)&digit.reply);
       *p++ = digit.reply.digit;
       if (revision.reply.firm_revision >= '3' ||
           (revision.reply.firm_revision == '3' &&
            revision.reply.firm_version >= '3')) {
               digit.cmd.opcode = BHA_INQUIRE_REVISION_4;
               bha_cmd(iot, ioh, name,
                   sizeof(digit.cmd), (u_char *)&digit.cmd,
                   sizeof(digit.reply), (u_char *)&digit.reply);
               *p++ = digit.reply.digit;
       }
       while (p > sc->sc_firmware && (p[-1] == ' ' || p[-1] == '\0'))
               p--;
       *p = '\0';

       /*
        * Get the model number.
        *
        * Some boards do not handle the Inquire Board Model Number
        * command correctly, or don't give correct information.
        *
        * So, we use the Firmware Revision and Extended Setup
        * information to fixup the model number in these cases.
        *
        * The firmware version indicates:
        *
        *      5.xx    BusLogic "W" Series Host Adapters
        *              BT-948/958/958D
        *
        *      4.xx    BusLogic "C" Series Host Adapters
        *              BT-946C/956C/956CD/747C/757C/757CD/445C/545C/540CF
        *
        *      3.xx    BusLogic "S" Series Host Adapters
        *              BT-747S/747D/757S/757D/445S/545S/542D
        *              BT-542B/742A (revision H)
        *
        *      2.xx    BusLogic "A" Series Host Adapters
        *              BT-542B/742A (revision G and below)
        *
        *      0.xx    AMI FastDisk VLB/EISA BusLogic Clone Host Adapter
        */
       if (inquire.reply.bus_type == BHA_BUS_TYPE_24BIT &&
           sc->sc_firmware[0] < '3')
               snprintf(sc->sc_model, sizeof(sc->sc_model), "542B");
       else if (inquire.reply.bus_type == BHA_BUS_TYPE_32BIT &&
           sc->sc_firmware[0] == '2' &&
           (sc->sc_firmware[2] == '1' ||
            (sc->sc_firmware[2] == '2' && sc->sc_firmware[3] == '0')))
               snprintf(sc->sc_model, sizeof(sc->sc_model), "742A");
       else if (inquire.reply.bus_type == BHA_BUS_TYPE_32BIT &&
           sc->sc_firmware[0] == '0')
               snprintf(sc->sc_model, sizeof(sc->sc_model), "747A");
       else {
               p = sc->sc_model;
               model.cmd.opcode = BHA_INQUIRE_MODEL;
               model.cmd.len = sizeof(model.reply);
               bha_cmd(iot, ioh, name,
                   sizeof(model.cmd), (u_char *)&model.cmd,
                   sizeof(model.reply), (u_char *)&model.reply);
               *p++ = model.reply.id[0];
               *p++ = model.reply.id[1];
               *p++ = model.reply.id[2];
               *p++ = model.reply.id[3];
               while (p > sc->sc_model && (p[-1] == ' ' || p[-1] == '\0'))
                       p--;
               *p++ = model.reply.version[0];
               *p++ = model.reply.version[1];
               while (p > sc->sc_model && (p[-1] == ' ' || p[-1] == '\0'))
                       p--;
               *p = '\0';
       }

       /* Enable round-robin scheme - appeared at firmware rev. 3.31. */
       if (strcmp(sc->sc_firmware, "3.31") >= 0)
               sc->sc_flags |= BHAF_STRICT_ROUND_ROBIN;

       /*
        * Determine some characteristics about our bus.
        */
       if (inquire.reply.scsi_flags & BHA_SCSI_WIDE)
               sc->sc_flags |= BHAF_WIDE;
       if (inquire.reply.scsi_flags & BHA_SCSI_DIFFERENTIAL)
               sc->sc_flags |= BHAF_DIFFERENTIAL;
       if (inquire.reply.scsi_flags & BHA_SCSI_ULTRA)
               sc->sc_flags |= BHAF_ULTRA;

       /*
        * Determine some characterists of the board.
        */
       sc->sc_max_dmaseg = inquire.reply.sg_limit;

       /*
        * Determine the maximum CCB count and whether or not
        * tagged queueing is available on this host adapter.
        *
        * Tagged queueing works on:
        *
        *      "W" Series adapters
        *      "C" Series adapters with firmware >= 4.22
        *      "S" Series adapters with firmware >= 3.35
        *
        * The internal CCB counts are:
        *
        *      192     BT-948/958/958D
        *      100     BT-946C/956C/956CD/747C/757C/757CD/445C
        *      50      BT-545C/540CF
        *      30      BT-747S/747D/757S/757D/445S/545S/542D/542B/742A
        */
       switch (sc->sc_firmware[0]) {
       case '5':
               sc->sc_max_ccbs = 192;
               sc->sc_flags |= BHAF_TAGGED_QUEUEING;
               break;

       case '4':
               if (sc->sc_model[0] == '5')
                       sc->sc_max_ccbs = 50;
               else
                       sc->sc_max_ccbs = 100;
               if (strcmp(sc->sc_firmware, "4.22") >= 0)
                       sc->sc_flags |= BHAF_TAGGED_QUEUEING;
               break;

       case '3':
               if (strcmp(sc->sc_firmware, "3.35") >= 0)
                       sc->sc_flags |= BHAF_TAGGED_QUEUEING;
               /* FALLTHROUGH */

       default:
               sc->sc_max_ccbs = 30;
       }

       /*
        * Set the mailbox count to precisely the number of HW CCBs
        * available.  A mailbox isn't required while a CCB is executing,
        * but this allows us to actually enqueue up to our resource
        * limit.
        *
        * This will keep the mailbox count small on boards which don't
        * have strict round-robin (they have to scan the entire set of
        * mailboxes each time they run a command).
        */
       sc->sc_mbox_count = sc->sc_max_ccbs;

       /*
        * Obtain setup information.
        */
       rlen = sizeof(setup.reply) +
           ((sc->sc_flags & BHAF_WIDE) ? sizeof(setup.reply_w) : 0);
       setup.cmd.opcode = BHA_INQUIRE_SETUP;
       setup.cmd.len = rlen;
       bha_cmd(iot, ioh, name,
           sizeof(setup.cmd), (u_char *)&setup.cmd,
           rlen, (u_char *)&setup.reply);

       aprint_normal_dev(sc->sc_dev, "model BT-%s, firmware %s\n",
           sc->sc_model, sc->sc_firmware);

       aprint_normal_dev(sc->sc_dev, "%d H/W CCBs", sc->sc_max_ccbs);
       if (setup.reply.sync_neg)
               aprint_normal(", sync");
       if (setup.reply.parity)
               aprint_normal(", parity");
       if (sc->sc_flags & BHAF_TAGGED_QUEUEING)
               aprint_normal(", tagged queueing");
       if (sc->sc_flags & BHAF_WIDE_LUN)
               aprint_normal(", wide LUN support");
       aprint_normal("\n");

       /*
        * Poll targets 0 - 7.
        */
       devices.cmd.opcode = BHA_INQUIRE_DEVICES;
       bha_cmd(iot, ioh, name,
           sizeof(devices.cmd), (u_char *)&devices.cmd,
           sizeof(devices.reply), (u_char *)&devices.reply);

       /* Count installed units. */
       initial_ccbs = 0;
       for (i = 0; i < 8; i++) {
               for (j = 0; j < 8; j++) {
                       if (((devices.reply.lun_map[i] >> j) & 1) == 1)
                               initial_ccbs++;
               }
       }

       /*
        * Poll targets 8 - 15 if we have a wide bus.
        */
       if (sc->sc_flags & BHAF_WIDE) {
               devices.cmd.opcode = BHA_INQUIRE_DEVICES_2;
               bha_cmd(iot, ioh, name,
                   sizeof(devices.cmd), (u_char *)&devices.cmd,
                   sizeof(devices.reply), (u_char *)&devices.reply);

               for (i = 0; i < 8; i++) {
                       for (j = 0; j < 8; j++) {
                               if (((devices.reply.lun_map[i] >> j) & 1) == 1)
                                       initial_ccbs++;
                       }
               }
       }

       /*
        * Double the initial CCB count, for good measure.
        */
       initial_ccbs *= 2;

       /*
        * Sanity check the initial CCB count; don't create more than
        * we can enqueue (sc_max_ccbs), and make sure there are some
        * at all.
        */
       if (initial_ccbs > sc->sc_max_ccbs)
               initial_ccbs = sc->sc_max_ccbs;
       if (initial_ccbs == 0)
               initial_ccbs = 2;

       return (initial_ccbs);
}

/*
* bha_init:
*
*      Initialize the board.
*/
static int
bha_init(struct bha_softc *sc)
{
       const char *name = device_xname(sc->sc_dev);
       struct bha_toggle toggle;
       struct bha_mailbox mailbox;
       struct bha_mbx_out *mbo;
       struct bha_mbx_in *mbi;
       int i;

       /*
        * Set up the mailbox.  We always run the mailbox in round-robin.
        */
       for (i = 0; i < sc->sc_mbox_count; i++) {
               mbo = &sc->sc_mbo[i];
               mbi = &sc->sc_mbi[i];

               mbo->cmd = BHA_MBO_FREE;
               BHA_MBO_SYNC(sc, mbo, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

               mbi->comp_stat = BHA_MBI_FREE;
               BHA_MBI_SYNC(sc, mbi, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
       }

       sc->sc_cmbo = sc->sc_tmbo = &sc->sc_mbo[0];
       sc->sc_tmbi = &sc->sc_mbi[0];

       sc->sc_mbofull = 0;

       /*
        * If the board supports strict round-robin, enable that.
        */
       if (sc->sc_flags & BHAF_STRICT_ROUND_ROBIN) {
               toggle.cmd.opcode = BHA_ROUND_ROBIN;
               toggle.cmd.enable = 1;
               bha_cmd(sc->sc_iot, sc->sc_ioh, name,
                   sizeof(toggle.cmd), (u_char *)&toggle.cmd,
                   0, NULL);
       }

       /*
        * Give the mailbox to the board.
        */
       mailbox.cmd.opcode = BHA_MBX_INIT_EXTENDED;
       mailbox.cmd.nmbx = sc->sc_mbox_count;
       ltophys(sc->sc_dmamap_mbox->dm_segs[0].ds_addr, mailbox.cmd.addr);
       bha_cmd(sc->sc_iot, sc->sc_ioh, name,
           sizeof(mailbox.cmd), (u_char *)&mailbox.cmd,
           0, (u_char *)0);

       return (0);
}

/*****************************************************************************
* CCB execution engine
*****************************************************************************/

/*
* bha_queue_ccb:
*
*      Queue a CCB to be sent to the controller, and send it if possible.
*/
static void
bha_queue_ccb(struct bha_softc *sc, struct bha_ccb *ccb)
{

       TAILQ_INSERT_TAIL(&sc->sc_waiting_ccb, ccb, chain);
       bha_start_ccbs(sc);
}

/*
* bha_start_ccbs:
*
*      Send as many CCBs as we have empty mailboxes for.
*/
static void
bha_start_ccbs(struct bha_softc *sc)
{
       bus_space_tag_t iot = sc->sc_iot;
       bus_space_handle_t ioh = sc->sc_ioh;
       struct bha_ccb_group *bcg;
       struct bha_mbx_out *mbo;
       struct bha_ccb *ccb;

       mbo = sc->sc_tmbo;

       while ((ccb = TAILQ_FIRST(&sc->sc_waiting_ccb)) != NULL) {
               if (sc->sc_mbofull >= sc->sc_mbox_count) {
#ifdef DIAGNOSTIC
                       if (sc->sc_mbofull > sc->sc_mbox_count)
                               panic("bha_start_ccbs: mbofull > mbox_count");
#endif
                       /*
                        * No mailboxes available; attempt to collect ones
                        * that have already been used.
                        */
                       bha_collect_mbo(sc);
                       if (sc->sc_mbofull == sc->sc_mbox_count) {
                               /*
                                * Still no more available; have the
                                * controller interrupt us when it
                                * frees one.
                                */
                               struct bha_toggle toggle;

                               toggle.cmd.opcode = BHA_MBO_INTR_EN;
                               toggle.cmd.enable = 1;
                               bha_cmd(iot, ioh, device_xname(sc->sc_dev),
                                   sizeof(toggle.cmd), (u_char *)&toggle.cmd,
                                   0, (u_char *)0);
                               break;
                       }
               }

               TAILQ_REMOVE(&sc->sc_waiting_ccb, ccb, chain);
#ifdef BHADIAG
               ccb->flags |= CCB_SENDING;
#endif

               /*
                * Put the CCB in the mailbox.
                */
               bcg = BHA_CCB_GROUP(ccb);
               ltophys(bcg->bcg_dmamap->dm_segs[0].ds_addr +
                   BHA_CCB_OFFSET(ccb), mbo->ccb_addr);
               if (ccb->flags & CCB_ABORT)
                       mbo->cmd = BHA_MBO_ABORT;
               else
                       mbo->cmd = BHA_MBO_START;

               BHA_MBO_SYNC(sc, mbo,
                   BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

               /* Tell the card to poll immediately. */
               bus_space_write_1(iot, ioh, BHA_CMD_PORT, BHA_START_SCSI);

               if ((ccb->xs->xs_control & XS_CTL_POLL) == 0)
                       callout_reset(&ccb->xs->xs_callout,
                           mstohz(ccb->timeout), bha_timeout, ccb);

               ++sc->sc_mbofull;
               mbo = bha_nextmbo(sc, mbo);
       }

       sc->sc_tmbo = mbo;
}

/*
* bha_finish_ccbs:
*
*      Finalize the execution of CCBs in our incoming mailbox.
*/
static void
bha_finish_ccbs(struct bha_softc *sc)
{
       struct bha_mbx_in *mbi;
       struct bha_ccb *ccb;
       int i;

       mbi = sc->sc_tmbi;

       BHA_MBI_SYNC(sc, mbi, BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);

       if (mbi->comp_stat == BHA_MBI_FREE) {
               for (i = 0; i < sc->sc_mbox_count; i++) {
                       if (mbi->comp_stat != BHA_MBI_FREE) {
#ifdef BHADIAG
                               /*
                                * This can happen in normal operation if
                                * we use all mailbox slots.
                                */
                               printf("%s: mbi not in round-robin order\n",
                                   device_xname(sc->sc_dev));
#endif
                               goto again;
                       }
                       mbi = bha_nextmbi(sc, mbi);
                       BHA_MBI_SYNC(sc, mbi,
                           BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
               }
#ifdef BHADIAGnot
               printf("%s: mbi interrupt with no full mailboxes\n",
                   device_xname(sc->sc_dev));
#endif
               return;
       }

again:
       do {
               ccb = bha_ccb_phys_kv(sc, phystol(mbi->ccb_addr));
               if (ccb == NULL) {
                       aprint_error_dev(sc->sc_dev, "bad mbi ccb pointer 0x%08x; skipping\n",
                           phystol(mbi->ccb_addr));
                       goto next;
               }

               BHA_CCB_SYNC(sc, ccb,
                   BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);

#ifdef BHADEBUG
               if (bha_debug) {
                       u_char *cp = ccb->scsi_cmd;
                       printf("op=%x %x %x %x %x %x\n",
                           cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
                       printf("comp_stat %x for mbi addr = %p, ",
                           mbi->comp_stat, mbi);
                       printf("ccb addr = %p\n", ccb);
               }
#endif /* BHADEBUG */

               switch (mbi->comp_stat) {
               case BHA_MBI_OK:
               case BHA_MBI_ERROR:
                       if ((ccb->flags & CCB_ABORT) != 0) {
                               /*
                                * If we already started an abort, wait for it
                                * to complete before clearing the CCB.  We
                                * could instead just clear CCB_SENDING, but
                                * what if the mailbox was already received?
                                * The worst that happens here is that we clear
                                * the CCB a bit later than we need to.  BFD.
                                */
                               goto next;
                       }
                       break;

               case BHA_MBI_ABORT:
               case BHA_MBI_UNKNOWN:
               case BHA_MBI_BADCCB:
                       /*
                        * Even if the CCB wasn't found, we clear it anyway.
                        * See preceding comment.
                        */
                       break;

               default:
                       aprint_error_dev(sc->sc_dev, "bad mbi comp_stat %02x; skipping\n",
                           mbi->comp_stat);
                       goto next;
               }

               callout_stop(&ccb->xs->xs_callout);
               bha_done(sc, ccb);

       next:
               mbi->comp_stat = BHA_MBI_FREE;
               BHA_CCB_SYNC(sc, ccb,
                   BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

               mbi = bha_nextmbi(sc, mbi);
               BHA_MBI_SYNC(sc, mbi,
                   BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
       } while (mbi->comp_stat != BHA_MBI_FREE);

       sc->sc_tmbi = mbi;
}

/*****************************************************************************
* Mailbox management functions.
*****************************************************************************/

/*
* bha_create_mailbox:
*
*      Create the mailbox structures.  Helper function for bha_attach().
*
*      NOTE: The Buslogic hardware only gets one DMA address for the
*      mailbox!  It expects:
*
*              mailbox_out[mailbox_size]
*              mailbox_in[mailbox_size]
*/
static int
bha_create_mailbox(struct bha_softc *sc)
{
       bus_dma_segment_t seg;
       size_t size;
       int error, rseg;

       size = (sizeof(struct bha_mbx_out) * sc->sc_mbox_count) +
              (sizeof(struct bha_mbx_in)  * sc->sc_mbox_count);

       error = bus_dmamem_alloc(sc->sc_dmat, size, PAGE_SIZE, 0, &seg,
           1, &rseg, sc->sc_dmaflags);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to allocate mailboxes, error = %d\n", error);
               goto bad_0;
       }

       error = bus_dmamem_map(sc->sc_dmat, &seg, rseg, size,
           (void **)&sc->sc_mbo, sc->sc_dmaflags | BUS_DMA_COHERENT);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to map mailboxes, error = %d\n", error);
               goto bad_1;
       }

       memset(sc->sc_mbo, 0, size);

       error = bus_dmamap_create(sc->sc_dmat, size, 1, size, 0,
           sc->sc_dmaflags, &sc->sc_dmamap_mbox);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to create mailbox DMA map, error = %d\n", error);
               goto bad_2;
       }

       error = bus_dmamap_load(sc->sc_dmat, sc->sc_dmamap_mbox,
           sc->sc_mbo, size, NULL, 0);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to load mailbox DMA map, error = %d\n", error);
               goto bad_3;
       }

       sc->sc_mbi = (struct bha_mbx_in *)(sc->sc_mbo + sc->sc_mbox_count);

       return (0);

bad_3:
       bus_dmamap_destroy(sc->sc_dmat, sc->sc_dmamap_mbox);
bad_2:
       bus_dmamem_unmap(sc->sc_dmat, (void *)sc->sc_mbo, size);
bad_1:
       bus_dmamem_free(sc->sc_dmat, &seg, rseg);
bad_0:
       return (error);
}

/*
* bha_collect_mbo:
*
*      Garbage collect mailboxes that are no longer in use.
*/
static void
bha_collect_mbo(struct bha_softc *sc)
{
       struct bha_mbx_out *mbo;
#ifdef BHADIAG
       struct bha_ccb *ccb;
#endif

       mbo = sc->sc_cmbo;

       while (sc->sc_mbofull > 0) {
               BHA_MBO_SYNC(sc, mbo,
                   BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
               if (mbo->cmd != BHA_MBO_FREE)
                       break;

#ifdef BHADIAG
               ccb = bha_ccb_phys_kv(sc, phystol(mbo->ccb_addr));
               ccb->flags &= ~CCB_SENDING;
#endif

               --sc->sc_mbofull;
               mbo = bha_nextmbo(sc, mbo);
       }

       sc->sc_cmbo = mbo;
}

/*****************************************************************************
* CCB management functions
*****************************************************************************/

static inline void
bha_reset_ccb(struct bha_ccb *ccb)
{

       ccb->flags = 0;
}

/*
* bha_create_ccbs:
*
*      Create a set of CCBs.
*
*      We determine the target CCB count, and then keep creating them
*      until we reach the target, or fail.  CCBs that are allocated
*      but not "created" are left on the allocating list.
*
*      XXX AB_QUIET/AB_SILENT lossage here; this is called during
*      boot as well as at run-time.
*/
static void
bha_create_ccbs(struct bha_softc *sc, int count)
{
       struct bha_ccb_group *bcg;
       struct bha_ccb *ccb;
       bus_dma_segment_t seg;
       bus_dmamap_t ccbmap;
       int target, i, error, rseg;

       /*
        * If the current CCB count is already the max number we're
        * allowed to have, bail out now.
        */
       if (sc->sc_cur_ccbs == sc->sc_max_ccbs)
               return;

       /*
        * Compute our target count, and clamp it down to the max
        * number we're allowed to have.
        */
       target = sc->sc_cur_ccbs + count;
       if (target > sc->sc_max_ccbs)
               target = sc->sc_max_ccbs;

       /*
        * If there are CCBs on the allocating list, don't allocate a
        * CCB group yet.
        */
       if (TAILQ_FIRST(&sc->sc_allocating_ccbs) != NULL)
               goto have_allocating_ccbs;

allocate_group:
       error = bus_dmamem_alloc(sc->sc_dmat, PAGE_SIZE,
           PAGE_SIZE, 0, &seg, 1, &rseg, sc->sc_dmaflags | BUS_DMA_NOWAIT);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to allocate CCB group, error = %d\n", error);
               goto bad_0;
       }

       error = bus_dmamem_map(sc->sc_dmat, &seg, rseg, PAGE_SIZE,
           (void *)&bcg,
           sc->sc_dmaflags | BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to map CCB group, error = %d\n", error);
               goto bad_1;
       }

       memset(bcg, 0, PAGE_SIZE);

       error = bus_dmamap_create(sc->sc_dmat, PAGE_SIZE,
           1, PAGE_SIZE, 0, sc->sc_dmaflags | BUS_DMA_NOWAIT, &ccbmap);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to create CCB group DMA map, error = %d\n", error);
               goto bad_2;
       }

       error = bus_dmamap_load(sc->sc_dmat, ccbmap, bcg, PAGE_SIZE, NULL,
           sc->sc_dmaflags | BUS_DMA_NOWAIT);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to load CCB group DMA map, error = %d\n", error);
               goto bad_3;
       }

       bcg->bcg_dmamap = ccbmap;

#ifdef DIAGNOSTIC
       if (BHA_CCB_GROUP(&bcg->bcg_ccbs[0]) !=
           BHA_CCB_GROUP(&bcg->bcg_ccbs[bha_ccbs_per_group - 1]))
               panic("bha_create_ccbs: CCB group size botch");
#endif

       /*
        * Add all of the CCBs in this group to the allocating list.
        */
       for (i = 0; i < bha_ccbs_per_group; i++) {
               ccb = &bcg->bcg_ccbs[i];
               TAILQ_INSERT_TAIL(&sc->sc_allocating_ccbs, ccb, chain);
       }

have_allocating_ccbs:
       /*
        * Loop over the allocating list until we reach our CCB target.
        * If we run out on the list, we'll allocate another group's
        * worth.
        */
       while (sc->sc_cur_ccbs < target) {
               ccb = TAILQ_FIRST(&sc->sc_allocating_ccbs);
               if (ccb == NULL)
                       goto allocate_group;
               if (bha_init_ccb(sc, ccb) != 0) {
                       /*
                        * We were unable to initialize the CCB.
                        * This is likely due to a resource shortage,
                        * so bail out now.
                        */
                       return;
               }
       }

       /*
        * If we got here, we've reached our target!
        */
       return;

bad_3:
       bus_dmamap_destroy(sc->sc_dmat, ccbmap);
bad_2:
       bus_dmamem_unmap(sc->sc_dmat, (void *)bcg, PAGE_SIZE);
bad_1:
       bus_dmamem_free(sc->sc_dmat, &seg, rseg);
bad_0:
       return;
}

/*
* bha_init_ccb:
*
*      Initialize a CCB; helper function for bha_create_ccbs().
*/
static int
bha_init_ccb(struct bha_softc *sc, struct bha_ccb *ccb)
{
       struct bha_ccb_group *bcg = BHA_CCB_GROUP(ccb);
       int hashnum, error;

       /*
        * Create the DMA map for this CCB.
        *
        * XXX ALLOCNOW is a hack to prevent bounce buffer shortages
        * XXX in the ISA case.  A better solution is needed.
        */
       error = bus_dmamap_create(sc->sc_dmat, BHA_MAXXFER, BHA_NSEG,
           BHA_MAXXFER, 0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW | sc->sc_dmaflags,
           &ccb->dmamap_xfer);
       if (error) {
               aprint_error_dev(sc->sc_dev,
                   "unable to create CCB DMA map, error = %d\n", error);
               return (error);
       }

       TAILQ_REMOVE(&sc->sc_allocating_ccbs, ccb, chain);

       /*
        * Put the CCB into the phystokv hash table.
        */
       ccb->hashkey = bcg->bcg_dmamap->dm_segs[0].ds_addr +
           BHA_CCB_OFFSET(ccb);
       hashnum = CCB_HASH(ccb->hashkey);
       ccb->nexthash = sc->sc_ccbhash[hashnum];
       sc->sc_ccbhash[hashnum] = ccb;
       bha_reset_ccb(ccb);

       TAILQ_INSERT_HEAD(&sc->sc_free_ccb, ccb, chain);
       sc->sc_cur_ccbs++;

       return (0);
}

/*
* bha_get_ccb:
*
*      Get a CCB for the SCSI operation.  If there are none left,
*      wait until one becomes available, if we can.
*/
static struct bha_ccb *
bha_get_ccb(struct bha_softc *sc)
{
       struct bha_ccb *ccb;
       int s;

       s = splbio();
       ccb = TAILQ_FIRST(&sc->sc_free_ccb);
       if (ccb != NULL) {
               TAILQ_REMOVE(&sc->sc_free_ccb, ccb, chain);
               ccb->flags |= CCB_ALLOC;
       }
       splx(s);
       return (ccb);
}

/*
* bha_free_ccb:
*
*      Put a CCB back onto the free list.
*/
static void
bha_free_ccb(struct bha_softc *sc, struct bha_ccb *ccb)
{
       int s;

       s = splbio();
       bha_reset_ccb(ccb);
       TAILQ_INSERT_HEAD(&sc->sc_free_ccb, ccb, chain);
       splx(s);
}

/*
* bha_ccb_phys_kv:
*
*      Given a CCB DMA address, locate the CCB in kernel virtual space.
*/
static struct bha_ccb *
bha_ccb_phys_kv(struct bha_softc *sc, bus_addr_t ccb_phys)
{
       int hashnum = CCB_HASH(ccb_phys);
       struct bha_ccb *ccb = sc->sc_ccbhash[hashnum];

       while (ccb) {
               if (ccb->hashkey == ccb_phys)
                       break;
               ccb = ccb->nexthash;
       }
       return (ccb);
}