dev/ic/aic7xxx_openbsd.c

/*	$OpenBSD: aic7xxx_openbsd.c,v 1.71 2020/09/22 19:32:52 krw Exp $	*/
/*	$NetBSD: aic7xxx_osm.c,v 1.14 2003/11/02 11:07:44 wiz Exp $	*/

/*
 * Bus independent OpenBSD shim for the aic7xxx based adaptec SCSI controllers
 *
 * Copyright (c) 1994-2001 Justin T. Gibbs.
 * Copyright (c) 2001-2002 Steve Murphree, Jr.
 * 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.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * //depot/aic7xxx/freebsd/dev/aic7xxx/aic7xxx_osm.c#12 $
 *
 * $FreeBSD: src/sys/dev/aic7xxx/aic7xxx_osm.c,v 1.31 2002/11/30 19:08:58 scottl Exp $
 */
/*
 * Ported from FreeBSD by Pascal Renauld, Network Storage Solutions, Inc. - April 2003
 */

#include <dev/ic/aic7xxx_openbsd.h>
#include <dev/ic/aic7xxx_inline.h>

#ifndef AHC_TMODE_ENABLE
#define AHC_TMODE_ENABLE 0
#endif


void	ahc_action(struct scsi_xfer *);
void	ahc_execute_scb(void *, bus_dma_segment_t *, int);
int	ahc_poll(struct ahc_softc *, int);
void	ahc_setup_data(struct ahc_softc *, struct scsi_xfer *, struct scb *);

void	ahc_adapter_req_set_xfer_mode(struct ahc_softc *, struct scb *);


struct cfdriver ahc_cd = {
	NULL, "ahc", DV_DULL
};

static struct scsi_adapter ahc_switch = {
	ahc_action, NULL, NULL, NULL, NULL
};

/*
 * Attach all the sub-devices we can find
 */
int
ahc_attach(struct ahc_softc *ahc)
{
	struct scsibus_attach_args saa;
	int s;

        s = splbio();

#ifndef DEBUG
	if (bootverbose) {
		char ahc_info[256];
		ahc_controller_info(ahc, ahc_info, sizeof ahc_info);
		printf("%s: %s\n", ahc->sc_dev.dv_xname, ahc_info);
	}
#endif

	ahc_intr_enable(ahc, TRUE);

	if (ahc->flags & AHC_RESET_BUS_A)
		ahc_reset_channel(ahc, 'A', TRUE);
	if ((ahc->features & AHC_TWIN) && ahc->flags & AHC_RESET_BUS_B)
		ahc_reset_channel(ahc, 'B', TRUE);

	saa.saa_adapter_buswidth = (ahc->features & AHC_WIDE) ? 16 :8;
	saa.saa_adapter_softc = ahc;
	saa.saa_adapter = &ahc_switch;
	saa.saa_luns = saa.saa_adapter_buswidth = 8;
	saa.saa_openings = 16;
	saa.saa_pool = &ahc->sc_iopool;
	saa.saa_quirks = saa.saa_flags = 0;
	saa.saa_wwpn = saa.saa_wwnn = 0;
	if ((ahc->flags & AHC_PRIMARY_CHANNEL) == 0) {
		saa.saa_adapter_target = ahc->our_id;
		ahc->sc_child = (struct scsibus_softc *)config_found(
		    (void *)&ahc->sc_dev, &saa, scsiprint);
		if (ahc->features & AHC_TWIN) {
			saa.saa_adapter_target = ahc->our_id_b;
			ahc->sc_child_b = (struct scsibus_softc *)config_found(
			    (void *)&ahc->sc_dev, &saa, scsiprint);
		}
	} else {
		if (ahc->features & AHC_TWIN) {
			saa.saa_adapter_target = ahc->our_id_b;
			ahc->sc_child = (struct scsibus_softc *)config_found(
			    (void *)&ahc->sc_dev, &saa, scsiprint);
		}
		saa.saa_adapter_target = ahc->our_id;
		ahc->sc_child_b = (struct scsibus_softc *)config_found(
		    (void *)&ahc->sc_dev, &saa, scsiprint);
	}

	splx(s);
	return (1);
}

/*
 * Catch an interrupt from the adapter
 */
int
ahc_platform_intr(void *arg)
{
	struct	ahc_softc *ahc = (struct ahc_softc *)arg;

	bus_dmamap_sync(ahc->parent_dmat, ahc->scb_data->hscb_dmamap,
	    0, ahc->scb_data->hscb_dmamap->dm_mapsize,
	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	return ahc_intr(ahc);
}

/*
 * We have an scb which has been processed by the
 * adaptor, now we look to see how the operation
 * went.
 */
void
ahc_done(struct ahc_softc *ahc, struct scb *scb)
{
	struct scsi_xfer *xs = scb->xs;

	bus_dmamap_sync(ahc->parent_dmat, ahc->scb_data->hscb_dmamap,
	    0, ahc->scb_data->hscb_dmamap->dm_mapsize,
	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	LIST_REMOVE(scb, pending_links);
	if ((scb->flags & SCB_UNTAGGEDQ) != 0) {
		struct scb_tailq *untagged_q;
		int target_offset;

		target_offset = SCB_GET_TARGET_OFFSET(ahc, scb);
		untagged_q = &ahc->untagged_queues[target_offset];
		TAILQ_REMOVE(untagged_q, scb, links.tqe);
		scb->flags &= ~SCB_UNTAGGEDQ;
		ahc_run_untagged_queue(ahc, untagged_q);
	}

	timeout_del(&xs->stimeout);

	if (xs->datalen) {
		int op;

		if ((xs->flags & SCSI_DATA_IN) != 0)
			op = BUS_DMASYNC_POSTREAD;
		else
			op = BUS_DMASYNC_POSTWRITE;
		bus_dmamap_sync(ahc->parent_dmat, scb->dmamap, 0,
				scb->dmamap->dm_mapsize, op);
		bus_dmamap_unload(ahc->parent_dmat, scb->dmamap);
	}

	/* Translate the CAM status code to a SCSI error code. */
	switch (xs->error) {
	case CAM_SCSI_STATUS_ERROR:
	case CAM_REQ_INPROG:
	case CAM_REQ_CMP:
		switch (xs->status) {
		case SCSI_TASKSET_FULL:
		case SCSI_BUSY:
			xs->error = XS_BUSY;
			break;
		case SCSI_CHECK:
		case SCSI_TERMINATED:
			if ((scb->flags & SCB_SENSE) == 0) {
				/* CHECK on CHECK? */
				xs->error = XS_DRIVER_STUFFUP;
			} else
				xs->error = XS_NOERROR;
			break;
		default:
			xs->error = XS_NOERROR;
			break;
		}
		break;
	case CAM_REQUEUE_REQ:
	case CAM_BUSY:
		xs->error = XS_BUSY;
		break;
	case CAM_CMD_TIMEOUT:
		xs->error = XS_TIMEOUT;
		break;
	case CAM_BDR_SENT:
	case CAM_SCSI_BUS_RESET:
		xs->error = XS_RESET;
		break;
	case CAM_SEL_TIMEOUT:
		xs->error = XS_SELTIMEOUT;
		break;
	default:
		xs->error = XS_DRIVER_STUFFUP;
		break;
	}

	/* Don't clobber any existing error state */
	if (xs->error != XS_NOERROR) {
	  /* Don't clobber any existing error state */
	} else if ((scb->flags & SCB_SENSE) != 0) {
		/*
		 * We performed autosense retrieval.
		 *
		 * Zero any sense not transferred by the
		 * device.  The SCSI spec mandates that any
		 * untransferred data should be assumed to be
		 * zero.  Complete the 'bounce' of sense information
		 * through buffers accessible via bus-space by
		 * copying it into the clients csio.
		 */
		memset(&xs->sense, 0, sizeof(struct scsi_sense_data));
		memcpy(&xs->sense, ahc_get_sense_buf(ahc, scb),
		    aic_le32toh(scb->sg_list->len) & AHC_SG_LEN_MASK);
		xs->error = XS_SENSE;
	}

	scsi_done(xs);
}

void
ahc_action(struct scsi_xfer *xs)
{
	struct ahc_softc *ahc;
	struct scb *scb;
	struct hardware_scb *hscb;
	u_int target_id;
	u_int our_id;

#ifdef AHC_DEBUG
	printf("%s: ahc_action\n", ahc_name(ahc));
#endif
	ahc = xs->sc_link->bus->sb_adapter_softc;

	target_id = xs->sc_link->target;
	our_id = SCSI_SCSI_ID(ahc, xs->sc_link);

	/*
	 * get the scb to use.
	 */
	scb = xs->io;

	/* Clean up for the next user */
	scb->flags = SCB_FLAG_NONE;

	hscb = scb->hscb;
	hscb->control = 0;
	ahc->scb_data->scbindex[hscb->tag] = NULL;

#ifdef AHC_DEBUG
	printf("%s: start scb(%p)\n", ahc_name(ahc), scb);
#endif
	scb->xs = xs;
	timeout_set(&xs->stimeout, ahc_timeout, scb);

	/*
	 * Put all the arguments for the xfer in the scb
	 */
	hscb->control = 0;
	hscb->scsiid = BUILD_SCSIID(ahc, xs->sc_link, target_id, our_id);
	hscb->lun = xs->sc_link->lun;
	if (xs->xs_control & XS_CTL_RESET) {
		hscb->cdb_len = 0;
		scb->flags |= SCB_DEVICE_RESET;
		hscb->control |= MK_MESSAGE;
		ahc_execute_scb(scb, NULL, 0);
		return;
	}

	ahc_setup_data(ahc, xs, scb);
}

void
ahc_execute_scb(void *arg, bus_dma_segment_t *dm_segs, int nsegments)
{
	struct	scb *scb;
	struct	scsi_xfer *xs;
	struct	ahc_softc *ahc;
	struct	ahc_initiator_tinfo *tinfo;
	struct	ahc_tmode_tstate *tstate;

	u_int	mask;
	int	s;

	scb = (struct scb *)arg;
	xs = scb->xs;
	xs->error = CAM_REQ_INPROG;
	xs->status = 0;
	ahc = xs->sc_link->bus->sb_adapter_softc;

	if (nsegments != 0) {
		struct	  ahc_dma_seg *sg;
		bus_dma_segment_t *end_seg;
		int op;

		end_seg = dm_segs + nsegments;

		/* Copy the segments into our SG list */
		sg = scb->sg_list;
		while (dm_segs < end_seg) {
			uint32_t len;

			sg->addr = aic_htole32(dm_segs->ds_addr);
			len = dm_segs->ds_len
			    | ((dm_segs->ds_addr >> 8) & 0x7F000000);
			sg->len = aic_htole32(len);
			sg++;
			dm_segs++;
		}

		/*
		 * Note where to find the SG entries in bus space.
		 * We also set the full residual flag which the
		 * sequencer will clear as soon as a data transfer
		 * occurs.
		 */
		scb->hscb->sgptr = aic_htole32(scb->sg_list_phys|SG_FULL_RESID);

		if ((xs->flags & SCSI_DATA_IN) != 0)
			op = BUS_DMASYNC_PREREAD;
		else
			op = BUS_DMASYNC_PREWRITE;

		bus_dmamap_sync(ahc->parent_dmat, scb->dmamap, 0,
				scb->dmamap->dm_mapsize, op);

		sg--;
		sg->len |= aic_htole32(AHC_DMA_LAST_SEG);

		bus_dmamap_sync(ahc->parent_dmat, scb->sg_map->sg_dmamap,
		    0, scb->sg_map->sg_dmamap->dm_mapsize,
		    BUS_DMASYNC_PREWRITE);

		/* Copy the first SG into the "current" data pointer area */
		scb->hscb->dataptr = scb->sg_list->addr;
		scb->hscb->datacnt = scb->sg_list->len;
	} else {
		scb->hscb->sgptr = aic_htole32(SG_LIST_NULL);
		scb->hscb->dataptr = 0;
		scb->hscb->datacnt = 0;
	}

	scb->sg_count = nsegments;

	s = splbio();

	tinfo = ahc_fetch_transinfo(ahc, SCSIID_CHANNEL(ahc, scb->hscb->scsiid),
				    SCSIID_OUR_ID(scb->hscb->scsiid),
				    SCSIID_TARGET(ahc, scb->hscb->scsiid),
				    &tstate);

	mask = SCB_GET_TARGET_MASK(ahc, scb);
	scb->hscb->scsirate = tinfo->scsirate;
	scb->hscb->scsioffset = tinfo->curr.offset;

	if ((tstate->ultraenb & mask) != 0)
		scb->hscb->control |= ULTRAENB;

	if ((tstate->discenable & mask) != 0)
		scb->hscb->control |= DISCENB;

	if ((tstate->auto_negotiate & mask) != 0) {
		scb->flags |= SCB_AUTO_NEGOTIATE;
		scb->hscb->control |= MK_MESSAGE;
	}

	if ((tstate->tagenable & mask) != 0)
		scb->hscb->control |= TAG_ENB;

	bus_dmamap_sync(ahc->parent_dmat, ahc->scb_data->hscb_dmamap,
	    0, ahc->scb_data->hscb_dmamap->dm_mapsize,
	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

	LIST_INSERT_HEAD(&ahc->pending_scbs, scb, pending_links);

	if (!(xs->flags & SCSI_POLL))
		timeout_add_msec(&xs->stimeout, xs->timeout);

	/*
	 * We only allow one untagged transaction
	 * per target in the initiator role unless
	 * we are storing a full busy target *lun*
	 * table in SCB space.
	 *
	 * This really should not be of any
	 * concern, as we take care to avoid this
	 * in ahc_done().  XXX smurph
	 */
	if ((scb->hscb->control & (TARGET_SCB|TAG_ENB)) == 0
	    && (ahc->flags & AHC_SCB_BTT) == 0) {
		struct scb_tailq *untagged_q;
		int target_offset;

		target_offset = SCB_GET_TARGET_OFFSET(ahc, scb);
		untagged_q = &(ahc->untagged_queues[target_offset]);
		TAILQ_INSERT_TAIL(untagged_q, scb, links.tqe);
		scb->flags |= SCB_UNTAGGEDQ;
		if (TAILQ_FIRST(untagged_q) != scb) {
			if (xs->flags & SCSI_POLL)
				goto poll;
			else {
				splx(s);
				return;
			}
		}
	}
	scb->flags |= SCB_ACTIVE;

	if ((scb->flags & SCB_TARGET_IMMEDIATE) != 0) {
		/* Define a mapping from our tag to the SCB. */
		ahc->scb_data->scbindex[scb->hscb->tag] = scb;
		ahc_pause(ahc);
		if ((ahc->flags & AHC_PAGESCBS) == 0)
			ahc_outb(ahc, SCBPTR, scb->hscb->tag);
		ahc_outb(ahc, TARG_IMMEDIATE_SCB, scb->hscb->tag);
		ahc_unpause(ahc);
	} else {
		ahc_queue_scb(ahc, scb);
	}

	if (!(xs->flags & SCSI_POLL)) {
		if (ahc->inited_target[xs->sc_link->target] == 0) {
			struct	ahc_devinfo devinfo;

			ahc_adapter_req_set_xfer_mode(ahc, scb);
			ahc_scb_devinfo(ahc, &devinfo, scb);
			ahc_update_neg_request(ahc, &devinfo, tstate, tinfo,
			    AHC_NEG_IF_NON_ASYNC);

			ahc->inited_target[xs->sc_link->target] = 1;
		}
		splx(s);
		return;
	}

	/*
	 * If we can't use interrupts, poll for completion
	 */
poll:
#ifdef AHC_DEBUG
	printf("%s: cmd_poll\n", ahc_name(ahc));
#endif

	do {
		if (ahc_poll(ahc, xs->timeout)) {
			if (!(xs->flags & SCSI_SILENT))
				printf("cmd fail\n");
			ahc_timeout(scb);
			break;
		}
	} while (!(xs->flags & ITSDONE));

	splx(s);
}

int
ahc_poll(struct ahc_softc *ahc, int wait)
{
	while (--wait) {
		DELAY(1000);
		if (ahc_inb(ahc, INTSTAT) & INT_PEND)
			break;
	}

	if (wait == 0) {
		printf("%s: board is not responding\n", ahc_name(ahc));
		return (EIO);
	}

	ahc_intr((void *)ahc);
	return (0);
}

void
ahc_setup_data(struct ahc_softc *ahc, struct scsi_xfer *xs,
	       struct scb *scb)
{
	struct hardware_scb *hscb;

	hscb = scb->hscb;
	xs->resid = xs->status = 0;
	xs->error = CAM_REQ_INPROG;

	hscb->cdb_len = xs->cmdlen;
	if (hscb->cdb_len > sizeof(hscb->cdb32)) {
		xs->error = XS_DRIVER_STUFFUP;
		scsi_done(xs);
		return;
	}

	if (hscb->cdb_len > 12) {
		memcpy(hscb->cdb32, &xs->cmd, hscb->cdb_len);
		scb->flags |= SCB_CDB32_PTR;
	} else {
		memcpy(hscb->shared_data.cdb, &xs->cmd, hscb->cdb_len);
	}

	/* Only use S/G if there is a transfer */
	if (xs->datalen) {
		int error;

                error = bus_dmamap_load(ahc->parent_dmat,
					scb->dmamap, xs->data,
					xs->datalen, NULL,
					(xs->flags & SCSI_NOSLEEP) ?
					BUS_DMA_NOWAIT : BUS_DMA_WAITOK);
		if (error) {
#ifdef AHC_DEBUG
                        printf("%s: in ahc_setup_data(): bus_dmamap_load() "
			       "= %d\n",
			       ahc_name(ahc), error);
#endif
			xs->error = XS_DRIVER_STUFFUP;
			scsi_done(xs);
			return;
		}
		ahc_execute_scb(scb, scb->dmamap->dm_segs,
		    scb->dmamap->dm_nsegs);
	} else {
		ahc_execute_scb(scb, NULL, 0);
	}
}

void
ahc_timeout(void *arg)
{
	struct	scb *scb, *list_scb;
	struct	ahc_softc *ahc;
	int	s;
	int	found;
	char	channel;

	scb = arg;
	ahc = scb->xs->sc_link->bus->sb_adapter_softc;

	s = splbio();

#ifdef AHC_DEBUG
	printf("%s: SCB %d timed out\n", ahc_name(ahc), scb->hscb->tag);
	ahc_dump_card_state(ahc);
#endif

	ahc_pause(ahc);

	if (scb->flags & SCB_ACTIVE) {
		channel = SCB_GET_CHANNEL(ahc, scb);
		ahc_set_transaction_status(scb, CAM_CMD_TIMEOUT);
		/*
		 * Go through all of our pending SCBs and remove
		 * any scheduled timeouts for them. They're about to be
		 * aborted so no need for them to timeout.
		 */
		LIST_FOREACH(list_scb, &ahc->pending_scbs, pending_links) {
			if (list_scb->xs)
				timeout_del(&list_scb->xs->stimeout);
		}
		found = ahc_reset_channel(ahc, channel, /*Initiate Reset*/TRUE);
#ifdef AHC_DEBUG
		printf("%s: Issued Channel %c Bus Reset %d SCBs aborted\n",
		    ahc_name(ahc), channel, found);
#endif
	}

	ahc_unpause(ahc);
	splx(s);
}


void
ahc_platform_set_tags(struct ahc_softc *ahc,
		      struct ahc_devinfo *devinfo, int alg)
{
	struct ahc_tmode_tstate *tstate;

	ahc_fetch_transinfo(ahc, devinfo->channel, devinfo->our_scsiid,
			    devinfo->target, &tstate);

	/* XXXX Need to check quirks before doing this! XXXX */

	switch (alg) {
	case AHC_QUEUE_BASIC:
	case AHC_QUEUE_TAGGED:
		tstate->tagenable |= devinfo->target_mask;
		break;
	case AHC_QUEUE_NONE:
		tstate->tagenable &= ~devinfo->target_mask;
		break;
	}
}

int
ahc_softc_comp(struct ahc_softc *lahc, struct ahc_softc *rahc)
{
	return (0);
}

void
ahc_send_async(struct ahc_softc *ahc, char channel, u_int target, u_int lun,
		ac_code code, void *opt_arg)
{
	/* Nothing to do here for OpenBSD */
}

void
ahc_adapter_req_set_xfer_mode(struct ahc_softc *ahc, struct scb *scb)
{
	struct ahc_initiator_tinfo *tinfo;
	struct ahc_tmode_tstate *tstate;
	struct ahc_syncrate *syncrate;
	struct ahc_devinfo devinfo;
	u_int16_t quirks;
	u_int width, ppr_options, period, offset;
	int s;

	s = splbio();

	ahc_scb_devinfo(ahc, &devinfo, scb);
	quirks = scb->xs->sc_link->quirks;
	tinfo = ahc_fetch_transinfo(ahc, devinfo.channel,
	    devinfo.our_scsiid, devinfo.target, &tstate);

	tstate->discenable |= (ahc->user_discenable & devinfo.target_mask);

	if (quirks & SDEV_NOTAGS)
		tstate->tagenable &= ~devinfo.target_mask;
	else if (ahc->user_tagenable & devinfo.target_mask)
		tstate->tagenable |= devinfo.target_mask;

	if (quirks & SDEV_NOWIDE)
		width = MSG_EXT_WDTR_BUS_8_BIT;
	else
		width = MSG_EXT_WDTR_BUS_16_BIT;

	ahc_validate_width(ahc, NULL, &width, ROLE_UNKNOWN);
	if (width > tinfo->user.width)
		width = tinfo->user.width;
	ahc_set_width(ahc, &devinfo, width, AHC_TRANS_GOAL, FALSE);

	if (quirks & SDEV_NOSYNC) {
		period = 0;
		offset = 0;
	} else {
		period = tinfo->user.period;
		offset = tinfo->user.offset;
	}

	/* XXX Look at saved INQUIRY flags for PPR capabilities XXX */
	ppr_options = tinfo->user.ppr_options;
	/* XXX Other reasons to avoid ppr? XXX */
	if (width < MSG_EXT_WDTR_BUS_16_BIT)
		ppr_options = 0;

	if ((tstate->discenable & devinfo.target_mask) == 0 ||
	    (tstate->tagenable & devinfo.target_mask) == 0)
		ppr_options &= ~MSG_EXT_PPR_PROT_IUS;

	syncrate = ahc_find_syncrate(ahc, &period, &ppr_options,
	    AHC_SYNCRATE_MAX);
	ahc_validate_offset(ahc, NULL, syncrate, &offset, width,
	    ROLE_UNKNOWN);

	if (offset == 0) {
		period = 0;
		ppr_options = 0;
	}

	if (ppr_options != 0 && tinfo->user.transport_version >= 3) {
		tinfo->goal.transport_version = tinfo->user.transport_version;
		tinfo->curr.transport_version = tinfo->user.transport_version;
	}

	ahc_set_syncrate(ahc, &devinfo, syncrate, period, offset, ppr_options,
	    AHC_TRANS_GOAL, FALSE);

	splx(s);
}

/*
 * Get a free scb. If there are none, see if we can allocate a new SCB.
 */
void *
ahc_scb_alloc(void *xahc)
{
	struct ahc_softc *ahc = xahc;
	struct scb *scb;

	mtx_enter(&ahc->sc_scb_mtx);
	scb = SLIST_FIRST(&ahc->scb_data->free_scbs);

	if (scb != NULL)
		SLIST_REMOVE_HEAD(&ahc->scb_data->free_scbs, links.sle);

	mtx_leave(&ahc->sc_scb_mtx);

	return (scb);
}

/*
 * Return an SCB resource to the free list.
 */
void
ahc_scb_free(void *xahc, void *io)
{
	struct ahc_softc *ahc = xahc;
	struct scb *scb = io;
	struct hardware_scb *hscb;

	hscb = scb->hscb;
	/* Clean up for the next user */
	ahc->scb_data->scbindex[hscb->tag] = NULL;
	scb->flags = SCB_FLAG_NONE;
	hscb->control = 0;

	mtx_enter(&ahc->sc_scb_mtx);
	SLIST_INSERT_HEAD(&ahc->scb_data->free_scbs, scb, links.sle);
	mtx_leave(&ahc->sc_scb_mtx);

	/* Notify the OSM that a resource is now available. */
	ahc_platform_scb_free(ahc, scb);
}