xref: /src/sys/dev/ic/adv.c

/*	$NetBSD: adv.c,v 1.20.2.1 2001/04/09 01:56:03 nathanw Exp $	*/

/*
 * Generic driver for the Advanced Systems Inc. Narrow SCSI controllers
 *
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Author: Baldassare Dante Profeta <dante (at) mclink.it>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE 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.
 */

#include <sys/types.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/malloc.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/user.h>

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

#include <uvm/uvm_extern.h>

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

#include <dev/ic/advlib.h>
#include <dev/ic/adv.h>

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


/* #define ASC_DEBUG */

/******************************************************************************/


static int adv_alloc_control_data __P((ASC_SOFTC *));
static void adv_free_control_data __P((ASC_SOFTC *));
static int adv_create_ccbs __P((ASC_SOFTC *, ADV_CCB *, int));
static void adv_free_ccb __P((ASC_SOFTC *, ADV_CCB *));
static void adv_reset_ccb __P((ADV_CCB *));
static int adv_init_ccb __P((ASC_SOFTC *, ADV_CCB *));
static ADV_CCB *adv_get_ccb __P((ASC_SOFTC *, int));
static void adv_queue_ccb __P((ASC_SOFTC *, ADV_CCB *));
static void adv_start_ccbs __P((ASC_SOFTC *));


static int adv_scsi_cmd __P((struct scsipi_xfer *));
static void advminphys __P((struct buf *));
static void adv_narrow_isr_callback __P((ASC_SOFTC *, ASC_QDONE_INFO *));

static int adv_poll __P((ASC_SOFTC *, struct scsipi_xfer *, int));
static void adv_timeout __P((void *));
static void adv_watchdog __P((void *));


/******************************************************************************/


/* the below structure is so we have a default dev struct for out link struct */
struct scsipi_device adv_dev =
{
	NULL,			/* Use default error handler */
	NULL,			/* have a queue, served by this */
	NULL,			/* have no async handler */
	NULL,			/* Use default 'done' routine */
};


#define ADV_ABORT_TIMEOUT       2000	/* time to wait for abort (mSec) */
#define ADV_WATCH_TIMEOUT       1000	/* time to wait for watchdog (mSec) */


/******************************************************************************/
/*                             Control Blocks routines                        */
/******************************************************************************/


static int
adv_alloc_control_data(sc)
	ASC_SOFTC      *sc;
{
	int error;

	/*
         * Allocate the control blocks.
         */
	if ((error = bus_dmamem_alloc(sc->sc_dmat, sizeof(struct adv_control),
			   PAGE_SIZE, 0, &sc->sc_control_seg, 1,
			   &sc->sc_control_nsegs, BUS_DMA_NOWAIT)) != 0) {
		printf("%s: unable to allocate control structures,"
		       " error = %d\n", sc->sc_dev.dv_xname, error);
		return (error);
	}
	if ((error = bus_dmamem_map(sc->sc_dmat, &sc->sc_control_seg,
			   sc->sc_control_nsegs, sizeof(struct adv_control),
			   (caddr_t *) & sc->sc_control,
			   BUS_DMA_NOWAIT | BUS_DMA_COHERENT)) != 0) {
		printf("%s: unable to map control structures, error = %d\n",
		       sc->sc_dev.dv_xname, error);
		return (error);
	}
	/*
         * Create and load the DMA map used for the control blocks.
         */
	if ((error = bus_dmamap_create(sc->sc_dmat, sizeof(struct adv_control),
			   1, sizeof(struct adv_control), 0, BUS_DMA_NOWAIT,
				       &sc->sc_dmamap_control)) != 0) {
		printf("%s: unable to create control DMA map, error = %d\n",
		       sc->sc_dev.dv_xname, error);
		return (error);
	}
	if ((error = bus_dmamap_load(sc->sc_dmat, sc->sc_dmamap_control,
			   sc->sc_control, sizeof(struct adv_control), NULL,
				     BUS_DMA_NOWAIT)) != 0) {
		printf("%s: unable to load control DMA map, error = %d\n",
		       sc->sc_dev.dv_xname, error);
		return (error);
	}

	/*
	 * Initialize the overrun_buf address.
	 */
	sc->overrun_buf = sc->sc_dmamap_control->dm_segs[0].ds_addr +
	    offsetof(struct adv_control, overrun_buf);

	return (0);
}

static void
adv_free_control_data(sc)
	ASC_SOFTC *sc;
{

	bus_dmamap_unload(sc->sc_dmat, sc->sc_dmamap_control);
	bus_dmamap_destroy(sc->sc_dmat, sc->sc_dmamap_control);
	sc->sc_dmamap_control = NULL;

	bus_dmamem_unmap(sc->sc_dmat, (caddr_t) sc->sc_control,
	    sizeof(struct adv_control));
	bus_dmamem_free(sc->sc_dmat, &sc->sc_control_seg,
	    sc->sc_control_nsegs);
}

/*
 * Create a set of ccbs and add them to the free list.  Called once
 * by adv_init().  We return the number of CCBs successfully created.
 */
static int
adv_create_ccbs(sc, ccbstore, count)
	ASC_SOFTC      *sc;
	ADV_CCB        *ccbstore;
	int             count;
{
	ADV_CCB        *ccb;
	int             i, error;

	bzero(ccbstore, sizeof(ADV_CCB) * count);
	for (i = 0; i < count; i++) {
		ccb = &ccbstore[i];
		if ((error = adv_init_ccb(sc, ccb)) != 0) {
			printf("%s: unable to initialize ccb, error = %d\n",
			       sc->sc_dev.dv_xname, error);
			return (i);
		}
		TAILQ_INSERT_TAIL(&sc->sc_free_ccb, ccb, chain);
	}

	return (i);
}


/*
 * A ccb is put onto the free list.
 */
static void
adv_free_ccb(sc, ccb)
	ASC_SOFTC      *sc;
	ADV_CCB        *ccb;
{
	int             s;

	s = splbio();

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

	/*
         * If there were none, wake anybody waiting for one to come free,
         * starting with queued entries.
         */
	if (ccb->chain.tqe_next == 0)
		wakeup(&sc->sc_free_ccb);

	splx(s);
}


static void
adv_reset_ccb(ccb)
	ADV_CCB        *ccb;
{

	ccb->flags = 0;
}


static int
adv_init_ccb(sc, ccb)
	ASC_SOFTC      *sc;
	ADV_CCB        *ccb;
{
	int	hashnum, error;

	callout_init(&ccb->ccb_watchdog);

	/*
         * Create the DMA map for this CCB.
         */
	error = bus_dmamap_create(sc->sc_dmat,
				  (ASC_MAX_SG_LIST - 1) * PAGE_SIZE,
			 ASC_MAX_SG_LIST, (ASC_MAX_SG_LIST - 1) * PAGE_SIZE,
		   0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW, &ccb->dmamap_xfer);
	if (error) {
		printf("%s: unable to create DMA map, error = %d\n",
		       sc->sc_dev.dv_xname, error);
		return (error);
	}

	/*
	 * put in the phystokv hash table
	 * Never gets taken out.
	 */
	ccb->hashkey = sc->sc_dmamap_control->dm_segs[0].ds_addr +
	    ADV_CCB_OFF(ccb);
	hashnum = CCB_HASH(ccb->hashkey);
	ccb->nexthash = sc->sc_ccbhash[hashnum];
	sc->sc_ccbhash[hashnum] = ccb;

	adv_reset_ccb(ccb);
	return (0);
}


/*
 * Get a free ccb
 *
 * If there are none, see if we can allocate a new one
 */
static ADV_CCB *
adv_get_ccb(sc, flags)
	ASC_SOFTC      *sc;
	int             flags;
{
	ADV_CCB        *ccb = 0;
	int             s;

	s = splbio();

	/*
         * If we can and have to, sleep waiting for one to come free
         * but only if we can't allocate a new one.
         */
	for (;;) {
		ccb = sc->sc_free_ccb.tqh_first;
		if (ccb) {
			TAILQ_REMOVE(&sc->sc_free_ccb, ccb, chain);
			break;
		}
		if ((flags & XS_CTL_NOSLEEP) != 0)
			goto out;

		tsleep(&sc->sc_free_ccb, PRIBIO, "advccb", 0);
	}

	ccb->flags |= CCB_ALLOC;

out:
	splx(s);
	return (ccb);
}


/*
 * Given a physical address, find the ccb that it corresponds to.
 */
ADV_CCB *
adv_ccb_phys_kv(sc, ccb_phys)
	ASC_SOFTC	*sc;
	u_long		ccb_phys;
{
	int hashnum = CCB_HASH(ccb_phys);
	ADV_CCB *ccb = sc->sc_ccbhash[hashnum];

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


/*
 * Queue a CCB to be sent to the controller, and send it if possible.
 */
static void
adv_queue_ccb(sc, ccb)
	ASC_SOFTC      *sc;
	ADV_CCB        *ccb;
{

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

	adv_start_ccbs(sc);
}


static void
adv_start_ccbs(sc)
	ASC_SOFTC      *sc;
{
	ADV_CCB        *ccb;

	while ((ccb = sc->sc_waiting_ccb.tqh_first) != NULL) {
		if (ccb->flags & CCB_WATCHDOG)
			callout_stop(&ccb->ccb_watchdog);

		if (AscExeScsiQueue(sc, &ccb->scsiq) == ASC_BUSY) {
			ccb->flags |= CCB_WATCHDOG;
			callout_reset(&ccb->ccb_watchdog,
			    (ADV_WATCH_TIMEOUT * hz) / 1000,
			    adv_watchdog, ccb);
			break;
		}
		TAILQ_REMOVE(&sc->sc_waiting_ccb, ccb, chain);

		if ((ccb->xs->xs_control & XS_CTL_POLL) == 0)
			callout_reset(&ccb->xs->xs_callout,
			    ((u_int64_t)ccb->timeout * (u_int64_t)hz) / 1000,
			    adv_timeout, ccb);
	}
}


/******************************************************************************/
/*                         SCSI layer interfacing routines                    */
/******************************************************************************/


int
adv_init(sc)
	ASC_SOFTC      *sc;
{
	int             warn;

	if (!AscFindSignature(sc->sc_iot, sc->sc_ioh)) {
		printf("adv_init: failed to find signature\n");
		return (1);
	}

	/*
         * Read the board configuration
         */
	AscInitASC_SOFTC(sc);
	warn = AscInitFromEEP(sc);
	if (warn) {
		printf("%s -get: ", sc->sc_dev.dv_xname);
		switch (warn) {
		case -1:
			printf("Chip is not halted\n");
			break;

		case -2:
			printf("Couldn't get MicroCode Start"
			       " address\n");
			break;

		case ASC_WARN_IO_PORT_ROTATE:
			printf("I/O port address modified\n");
			break;

		case ASC_WARN_AUTO_CONFIG:
			printf("I/O port increment switch enabled\n");
			break;

		case ASC_WARN_EEPROM_CHKSUM:
			printf("EEPROM checksum error\n");
			break;

		case ASC_WARN_IRQ_MODIFIED:
			printf("IRQ modified\n");
			break;

		case ASC_WARN_CMD_QNG_CONFLICT:
			printf("tag queuing enabled w/o disconnects\n");
			break;

		default:
			printf("unknown warning %d\n", warn);
		}
	}
	if (sc->scsi_reset_wait > ASC_MAX_SCSI_RESET_WAIT)
		sc->scsi_reset_wait = ASC_MAX_SCSI_RESET_WAIT;

	/*
         * Modify the board configuration
         */
	warn = AscInitFromASC_SOFTC(sc);
	if (warn) {
		printf("%s -set: ", sc->sc_dev.dv_xname);
		switch (warn) {
		case ASC_WARN_CMD_QNG_CONFLICT:
			printf("tag queuing enabled w/o disconnects\n");
			break;

		case ASC_WARN_AUTO_CONFIG:
			printf("I/O port increment switch enabled\n");
			break;

		default:
			printf("unknown warning %d\n", warn);
		}
	}
	sc->isr_callback = (ASC_CALLBACK) adv_narrow_isr_callback;

	return (0);
}


void
adv_attach(sc)
	ASC_SOFTC      *sc;
{
	int             i, error;

	/*
         * Initialize board RISC chip and enable interrupts.
         */
	switch (AscInitDriver(sc)) {
	case 0:
		/* AllOK */
		break;

	case 1:
		panic("%s: bad signature", sc->sc_dev.dv_xname);
		break;

	case 2:
		panic("%s: unable to load MicroCode",
		      sc->sc_dev.dv_xname);
		break;

	case 3:
		panic("%s: unable to initialize MicroCode",
		      sc->sc_dev.dv_xname);
		break;

	default:
		panic("%s: unable to initialize board RISC chip",
		      sc->sc_dev.dv_xname);
	}

	/*
	 * Fill in the adapter.
	 */
	sc->sc_adapter.scsipi_cmd = adv_scsi_cmd;
	sc->sc_adapter.scsipi_minphys = advminphys;

	/*
         * fill in the prototype scsipi_link.
         */
	sc->sc_link.scsipi_scsi.channel = SCSI_CHANNEL_ONLY_ONE;
	sc->sc_link.adapter_softc = sc;
	sc->sc_link.scsipi_scsi.adapter_target = sc->chip_scsi_id;
	sc->sc_link.adapter = &sc->sc_adapter;
	sc->sc_link.device = &adv_dev;
	sc->sc_link.openings = 4;
	sc->sc_link.scsipi_scsi.max_target = 7;
	sc->sc_link.scsipi_scsi.max_lun = 7;
	sc->sc_link.type = BUS_SCSI;


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


	/*
         * Allocate the Control Blocks and the overrun buffer.
         */
	error = adv_alloc_control_data(sc);
	if (error)
		return; /* (error) */

	/*
         * Create and initialize the Control Blocks.
         */
	i = adv_create_ccbs(sc, sc->sc_control->ccbs, ADV_MAX_CCB);
	if (i == 0) {
		printf("%s: unable to create control blocks\n",
		       sc->sc_dev.dv_xname);
		return; /* (ENOMEM) */ ;
	} else if (i != ADV_MAX_CCB) {
		printf("%s: WARNING: only %d of %d control blocks created\n",
		       sc->sc_dev.dv_xname, i, ADV_MAX_CCB);
	}
	sc->sc_child = config_found(&sc->sc_dev, &sc->sc_link, scsiprint);
}

int
adv_detach(sc, flags)
	ASC_SOFTC *sc;
	int flags;
{
	int rv = 0;

	if (sc->sc_child != NULL)
		rv = config_detach(sc->sc_child, flags);

	adv_free_control_data(sc);

	return (rv);
}

static void
advminphys(bp)
	struct buf     *bp;
{

	if (bp->b_bcount > ((ASC_MAX_SG_LIST - 1) * PAGE_SIZE))
		bp->b_bcount = ((ASC_MAX_SG_LIST - 1) * PAGE_SIZE);
	minphys(bp);
}


/*
 * start a scsi operation given the command and the data address.  Also needs
 * the unit, target and lu.
 */
static int
adv_scsi_cmd(xs)
	struct scsipi_xfer *xs;
{
	struct scsipi_link *sc_link = xs->sc_link;
	ASC_SOFTC      *sc = sc_link->adapter_softc;
	bus_dma_tag_t   dmat = sc->sc_dmat;
	ADV_CCB        *ccb;
	int             s, flags, error, nsegs;
	int             fromqueue = 0, dontqueue = 0, nowait = 0;


	s = splbio();		/* protect the queue */

	/*
         * If we're running the queue from adv_done(), we've been
         * called with the first queue entry as our argument.
         */
	if (xs == TAILQ_FIRST(&sc->sc_queue)) {
		TAILQ_REMOVE(&sc->sc_queue, xs, adapter_q);
		fromqueue = 1;
		nowait = 1;
	} else {

		/* Polled requests can't be queued for later. */
		dontqueue = xs->xs_control & XS_CTL_POLL;

		/*
                 * If there are jobs in the queue, run them first.
                 */
		if (TAILQ_FIRST(&sc->sc_queue) != NULL) {
			/*
                         * If we can't queue, we have to abort, since
                         * we have to preserve order.
                         */
			if (dontqueue) {
				splx(s);
				xs->error = XS_DRIVER_STUFFUP;
				return (TRY_AGAIN_LATER);
			}
			/*
                         * Swap with the first queue entry.
                         */
			TAILQ_INSERT_TAIL(&sc->sc_queue, xs, adapter_q);
			xs = TAILQ_FIRST(&sc->sc_queue);
			TAILQ_REMOVE(&sc->sc_queue, xs, adapter_q);
			fromqueue = 1;
		}
	}


	/*
         * get a ccb to use. If the transfer
         * is from a buf (possibly from interrupt time)
         * then we can't allow it to sleep
         */

	flags = xs->xs_control;
	if (nowait)
		flags |= XS_CTL_NOSLEEP;
	if ((ccb = adv_get_ccb(sc, flags)) == NULL) {
		/*
                 * If we can't queue, we lose.
                 */
		if (dontqueue) {
			splx(s);
			xs->error = XS_DRIVER_STUFFUP;
			return (TRY_AGAIN_LATER);
		}
		/*
                 * Stuff ourselves into the queue, in front
                 * if we came off in the first place.
                 */
		if (fromqueue)
			TAILQ_INSERT_HEAD(&sc->sc_queue, xs, adapter_q);
		else
			TAILQ_INSERT_TAIL(&sc->sc_queue, xs, adapter_q);
		splx(s);
		return (SUCCESSFULLY_QUEUED);
	}
	splx(s);		/* done playing with the queue */

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

	/*
         * Build up the request
         */
	memset(&ccb->scsiq, 0, sizeof(ASC_SCSI_Q));

	ccb->scsiq.q2.ccb_ptr = sc->sc_dmamap_control->dm_segs[0].ds_addr +
		    ADV_CCB_OFF(ccb);

	ccb->scsiq.cdbptr = &xs->cmd->opcode;
	ccb->scsiq.q2.cdb_len = xs->cmdlen;
	ccb->scsiq.q1.target_id = ASC_TID_TO_TARGET_ID(sc_link->scsipi_scsi.target);
	ccb->scsiq.q1.target_lun = sc_link->scsipi_scsi.lun;
	ccb->scsiq.q2.target_ix = ASC_TIDLUN_TO_IX(sc_link->scsipi_scsi.target,
						   sc_link->scsipi_scsi.lun);
	ccb->scsiq.q1.sense_addr = sc->sc_dmamap_control->dm_segs[0].ds_addr +
		ADV_CCB_OFF(ccb) + offsetof(struct adv_ccb, scsi_sense);
	ccb->scsiq.q1.sense_len = sizeof(struct scsipi_sense_data);

	/*
         * If  there  are  any  outstanding  requests  for  the  current target,
         * then  every  255th request  send an  ORDERED request.  This heuristic
         * tries  to  retain  the  benefit  of request  sorting while preventing
         * request starvation. 255 is the max number of tags or pending commands
         * a device may have outstanding.
         */
	sc->reqcnt[sc_link->scsipi_scsi.target]++;
	if ((sc->reqcnt[sc_link->scsipi_scsi.target] > 0) &&
	    (sc->reqcnt[sc_link->scsipi_scsi.target] % 255) == 0) {
		ccb->scsiq.q2.tag_code = M2_QTAG_MSG_ORDERED;
	} else {
		if((xs->bp != NULL) && xs->bp->b_flags & B_ASYNC)
			ccb->scsiq.q2.tag_code = M2_QTAG_MSG_SIMPLE;
		else
			ccb->scsiq.q2.tag_code = M2_QTAG_MSG_ORDERED;
	}


	if (xs->datalen) {
		/*
                 * Map the DMA transfer.
                 */
#ifdef TFS
		if (flags & SCSI_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);
		} 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);
		}

		if (error) {
			if (error == EFBIG) {
				printf("%s: adv_scsi_cmd, more than %d dma"
				       " segments\n",
				       sc->sc_dev.dv_xname, ASC_MAX_SG_LIST);
			} else {
				printf("%s: adv_scsi_cmd, error %d loading"
				       " dma map\n",
				       sc->sc_dev.dv_xname, error);
			}

			xs->error = XS_DRIVER_STUFFUP;
			adv_free_ccb(sc, ccb);
			return (COMPLETE);
		}
		bus_dmamap_sync(dmat, ccb->dmamap_xfer, 0,
				ccb->dmamap_xfer->dm_mapsize,
			      (flags & XS_CTL_DATA_IN) ? BUS_DMASYNC_PREREAD :
				BUS_DMASYNC_PREWRITE);


		memset(&ccb->sghead, 0, sizeof(ASC_SG_HEAD));

		for (nsegs = 0; nsegs < ccb->dmamap_xfer->dm_nsegs; nsegs++) {

			ccb->sghead.sg_list[nsegs].addr =
				ccb->dmamap_xfer->dm_segs[nsegs].ds_addr;
			ccb->sghead.sg_list[nsegs].bytes =
				ccb->dmamap_xfer->dm_segs[nsegs].ds_len;
		}

		ccb->sghead.entry_cnt = ccb->scsiq.q1.sg_queue_cnt =
			ccb->dmamap_xfer->dm_nsegs;

		ccb->scsiq.q1.cntl |= ASC_QC_SG_HEAD;
		ccb->scsiq.sg_head = &ccb->sghead;
		ccb->scsiq.q1.data_addr = 0;
		ccb->scsiq.q1.data_cnt = 0;
	} else {
		/*
                 * No data xfer, use non S/G values.
                 */
		ccb->scsiq.q1.data_addr = 0;
		ccb->scsiq.q1.data_cnt = 0;
	}

#ifdef ASC_DEBUG
	printf("id = %d, lun = %d, cmd = %d, ccb = 0x%lX \n",
			sc_link->scsipi_scsi.target,
			sc_link->scsipi_scsi.lun, xs->cmd->opcode,
			(unsigned long)ccb);
#endif
	s = splbio();
	adv_queue_ccb(sc, ccb);
	splx(s);

	/*
         * Usually return SUCCESSFULLY QUEUED
         */
	if ((flags & XS_CTL_POLL) == 0)
		return (SUCCESSFULLY_QUEUED);

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


int
adv_intr(arg)
	void           *arg;
{
	ASC_SOFTC      *sc = arg;
	struct scsipi_xfer *xs;

#ifdef ASC_DEBUG
	int int_pend = FALSE;

	if(ASC_IS_INT_PENDING(sc->sc_iot, sc->sc_ioh))
	{
		int_pend = TRUE;
		printf("ISR - ");
	}
#endif
	AscISR(sc);
#ifdef ASC_DEBUG
	if(int_pend)
		printf("\n");
#endif

	/*
         * If there are queue entries in the software queue, try to
         * run the first one.  We should be more or less guaranteed
         * to succeed, since we just freed a CCB.
         *
         * NOTE: adv_scsi_cmd() relies on our calling it with
         * the first entry in the queue.
         */
	if ((xs = TAILQ_FIRST(&sc->sc_queue)) != NULL)
		(void) adv_scsi_cmd(xs);

	return (1);
}


/*
 * Poll a particular unit, looking for a particular xs
 */
static int
adv_poll(sc, xs, count)
	ASC_SOFTC      *sc;
	struct scsipi_xfer *xs;
	int             count;
{

	/* timeouts are in msec, so we loop in 1000 usec cycles */
	while (count) {
		adv_intr(sc);
		if (xs->xs_status & XS_STS_DONE)
			return (0);
		delay(1000);	/* only happens in boot so ok */
		count--;
	}
	return (1);
}


static void
adv_timeout(arg)
	void           *arg;
{
	ADV_CCB        *ccb = arg;
	struct scsipi_xfer *xs = ccb->xs;
	struct scsipi_link *sc_link = xs->sc_link;
	ASC_SOFTC      *sc = sc_link->adapter_softc;
	int             s;

	scsi_print_addr(sc_link);
	printf("timed out");

	s = splbio();

	/*
         * If it has been through before, then a previous abort has failed,
         * don't try abort again, reset the bus instead.
         */
	if (ccb->flags & CCB_ABORT) {
		/* abort timed out */
		printf(" AGAIN. Resetting Bus\n");
		/* Lets try resetting the bus! */
		if (AscResetBus(sc) == ASC_ERROR) {
			ccb->timeout = sc->scsi_reset_wait;
			adv_queue_ccb(sc, ccb);
		}
	} else {
		/* abort the operation that has timed out */
		printf("\n");
		AscAbortCCB(sc, ccb);
		ccb->xs->error = XS_TIMEOUT;
		ccb->timeout = ADV_ABORT_TIMEOUT;
		ccb->flags |= CCB_ABORT;
		adv_queue_ccb(sc, ccb);
	}

	splx(s);
}


static void
adv_watchdog(arg)
	void           *arg;
{
	ADV_CCB        *ccb = arg;
	struct scsipi_xfer *xs = ccb->xs;
	struct scsipi_link *sc_link = xs->sc_link;
	ASC_SOFTC      *sc = sc_link->adapter_softc;
	int             s;

	s = splbio();

	ccb->flags &= ~CCB_WATCHDOG;
	adv_start_ccbs(sc);

	splx(s);
}


/******************************************************************************/
/*                      NARROW boards Interrupt callbacks                     */
/******************************************************************************/


/*
 * adv_narrow_isr_callback() - Second Level Interrupt Handler called by AscISR()
 *
 * Interrupt callback function for the Narrow SCSI Asc Library.
 */
static void
adv_narrow_isr_callback(sc, qdonep)
	ASC_SOFTC      *sc;
	ASC_QDONE_INFO *qdonep;
{
	bus_dma_tag_t   dmat = sc->sc_dmat;
	ADV_CCB        *ccb;
	struct scsipi_xfer *xs;
	struct scsipi_sense_data *s1, *s2;


	ccb = adv_ccb_phys_kv(sc, qdonep->d2.ccb_ptr);
	xs = ccb->xs;

#ifdef ASC_DEBUG
	printf(" - ccb=0x%lx, id=%d, lun=%d, cmd=%d, ",
			(unsigned long)ccb,
			xs->sc_link->scsipi_scsi.target,
			xs->sc_link->scsipi_scsi.lun, xs->cmd->opcode);
#endif
	callout_stop(&ccb->xs->xs_callout);

	/*
         * 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 ((ccb->flags & CCB_ALLOC) == 0) {
		printf("%s: exiting ccb not allocated!\n", sc->sc_dev.dv_xname);
		Debugger();
		return;
	}
	/*
         * 'qdonep' contains the command's ending status.
         */
#ifdef ASC_DEBUG
	printf("d_s=%d, h_s=%d", qdonep->d3.done_stat, qdonep->d3.host_stat);
#endif
	switch (qdonep->d3.done_stat) {
	case ASC_QD_NO_ERROR:
		switch (qdonep->d3.host_stat) {
		case ASC_QHSTA_NO_ERROR:
			xs->error = XS_NOERROR;
			xs->resid = 0;
			break;

		default:
			/* QHSTA error occurred */
			xs->error = XS_DRIVER_STUFFUP;
			break;
		}

		/*
                 * If an INQUIRY command completed successfully, then call
                 * the AscInquiryHandling() function to patch bugged boards.
                 */
		if ((xs->cmd->opcode == SCSICMD_Inquiry) &&
		    (xs->sc_link->scsipi_scsi.lun == 0) &&
		    (xs->datalen - qdonep->remain_bytes) >= 8) {
			AscInquiryHandling(sc,
				      xs->sc_link->scsipi_scsi.target & 0x7,
					   (ASC_SCSI_INQUIRY *) xs->data);
		}
		break;

	case ASC_QD_WITH_ERROR:
		switch (qdonep->d3.host_stat) {
		case ASC_QHSTA_NO_ERROR:
			if (qdonep->d3.scsi_stat == SS_CHK_CONDITION) {
				s1 = &ccb->scsi_sense;
				s2 = &xs->sense.scsi_sense;
				*s2 = *s1;
				xs->error = XS_SENSE;
			} else {
				xs->error = XS_DRIVER_STUFFUP;
			}
			break;

		default:
			/* QHSTA error occurred */
			xs->error = XS_DRIVER_STUFFUP;
			break;
		}
		break;

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


	adv_free_ccb(sc, ccb);
	xs->xs_status |= XS_STS_DONE;
	scsipi_done(xs);
}