dev/isa/wds.c

/*	$OpenBSD: wds.c,v 1.42 2014/09/14 14:17:25 jsg Exp $	*/
/*	$NetBSD: wds.c,v 1.13 1996/11/03 16:20:31 mycroft Exp $	*/

#undef	WDSDIAG
#ifdef DDB
#define	integrate
#else
#define	integrate	static inline
#endif

/*
 * XXX
 * sense data
 * aborts
 * resets
 */

/*
 * Copyright (c) 1994, 1995 Julian Highfield.  All rights reserved.
 * Portions copyright (c) 1994, 1996 Charles M. Hannum.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Julian Highfield.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This driver is for the WD7000 family of SCSI controllers:
 *   the WD7000-ASC, a bus-mastering DMA controller,
 *   the WD7000-FASST2, an -ASC with new firmware and scatter-gather,
 *   and the WD7000-ASE, which was custom manufactured for Apollo
 *      workstations and seems to include an -ASC as well as floppy
 *      and ESDI interfaces.
 *
 * Loosely based on Theo Deraadt's unfinished attempt says the NetBSD group
 * so they decided to delete the copyright that file had on it.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <uvm/uvm_extern.h>

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

#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>

#include <dev/isa/isavar.h>
#include <dev/isa/isadmavar.h>
#include <dev/isa/wdsreg.h>

#define WDS_MBX_SIZE	16

#define WDS_SCB_MAX	32
#define	SCB_HASH_SIZE	32	/* hash table size for phystokv */
#define	SCB_HASH_SHIFT	9
#define	SCB_HASH(x)	((((long)(x))>>SCB_HASH_SHIFT) & (SCB_HASH_SIZE - 1))

#define	wds_nextmbx(wmb, mbx, mbio) \
	if ((wmb) == &(mbx)->mbio[WDS_MBX_SIZE - 1])	\
		(wmb) = &(mbx)->mbio[0];		\
	else						\
		(wmb)++;

struct wds_mbx {
	struct wds_mbx_out mbo[WDS_MBX_SIZE];
	struct wds_mbx_in mbi[WDS_MBX_SIZE];
	struct wds_mbx_out *cmbo;	/* Collection Mail Box out */
	struct wds_mbx_out *tmbo;	/* Target Mail Box out */
	struct wds_mbx_in *tmbi;	/* Target Mail Box in */
};

#define	KVTOPHYS(x)	vtophys((vaddr_t)(x))

struct wds_softc {
	struct device sc_dev;
	struct isadev sc_id;
	void *sc_ih;

	bus_space_tag_t sc_iot;		/* bus identifier */
	bus_space_handle_t sc_ioh;	/* io handle */
	int sc_irq, sc_drq;

	int sc_revision;

	struct wds_mbx sc_mbx;
#define	wmbx	(&sc->sc_mbx)
	struct wds_scb *sc_scbhash[SCB_HASH_SIZE];
	TAILQ_HEAD(, wds_scb) sc_free_scb, sc_waiting_scb;
	int sc_numscbs, sc_mbofull;
	int sc_scsi_dev;
	struct scsi_link sc_link;	/* prototype for subdevs */

	struct mutex		sc_scb_mtx;
	struct scsi_iopool	sc_iopool;
};

/* Define the bounce buffer length... */
#define BUFLEN (64*1024)
/* ..and how many there are. One per device! Non-FASST boards need these. */
#define BUFCNT 8
/* The macro for deciding whether the board needs a buffer. */
#define NEEDBUFFER(sc)	(sc->sc_revision < 0x800)

struct wds_buf {
	u_char data[BUFLEN];
	int    busy;
	TAILQ_ENTRY(wds_buf) chain;
} wds_buffer[BUFCNT];

TAILQ_HEAD(, wds_buf) wds_free_buffer;

#ifdef WDSDEBUG
int wds_debug = WDSDEBUG;
#endif

integrate void    wds_wait(bus_space_tag_t, bus_space_handle_t, int, int, int);
int     wds_cmd(struct wds_softc *, u_char *, int);
integrate void wds_finish_scbs(struct wds_softc *);
int     wdsintr(void *);
integrate void wds_reset_scb(struct wds_softc *, struct wds_scb *);
void    wds_scb_free(void *, void *);
void	wds_free_buf(struct wds_softc *, struct wds_buf *);
integrate void wds_init_scb(struct wds_softc *, struct wds_scb *);
void *wds_scb_alloc(void *);
struct	wds_buf *wds_get_buf(struct wds_softc *, int);
struct	wds_scb *wds_scb_phys_kv(struct wds_softc *, u_long);
void	wds_queue_scb(struct wds_softc *, struct wds_scb *);
void	wds_collect_mbo(struct wds_softc *);
void	wds_start_scbs(struct wds_softc *);
void    wds_done(struct wds_softc *, struct wds_scb *, u_char);
int	wds_find(struct isa_attach_args *, struct wds_softc *);
void	wds_init(struct wds_softc *);
void	wds_inquire_setup_information(struct wds_softc *);
void    wdsminphys(struct buf *, struct scsi_link *);
void    wds_scsi_cmd(struct scsi_xfer *);
void	wds_sense(struct wds_softc *, struct wds_scb *);
int	wds_poll(struct wds_softc *, struct scsi_xfer *, int);
int	wds_ipoll(struct wds_softc *, struct wds_scb *, int);
void	wds_timeout(void *);
int	wdsprint(void *, const char *);

struct scsi_adapter wds_switch = {
	wds_scsi_cmd,
	wdsminphys,
	0,
	0,
};

int	wdsprobe(struct device *, void *, void *);
void	wdsattach(struct device *, struct device *, void *);

struct cfattach wds_ca = {
	sizeof(struct wds_softc), wdsprobe, wdsattach
};

struct cfdriver wds_cd = {
	NULL, "wds", DV_DULL
};

#define	WDS_ABORT_TIMEOUT	2000	/* time to wait for abort (mSec) */

integrate void
wds_wait(bus_space_tag_t iot, bus_space_handle_t ioh, int port, int mask,
    int val)
{
	while ((bus_space_read_1(iot, ioh, port) & mask) != val)
		;
}

/*
 * Write a command to the board's I/O ports.
 */
int
wds_cmd(struct wds_softc *sc,  u_int8_t *ibuf, int icnt)
{
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	u_int8_t c;

	wds_wait(iot, ioh, WDS_STAT, WDSS_RDY, WDSS_RDY);

	while (icnt--) {
		bus_space_write_1(iot, ioh, WDS_CMD, *ibuf++);
		wds_wait(iot, ioh, WDS_STAT, WDSS_RDY, WDSS_RDY);
		c = bus_space_read_1(iot, ioh, WDS_STAT);
		if (c & WDSS_REJ)
			return 1;
	}

	return 0;
}

/*
 * Check for the presence of a WD7000 SCSI controller.
 */
int
wdsprobe(struct device *parent, void *match, void *aux)
{
	register struct isa_attach_args *ia = aux;
	bus_space_tag_t iot = ia->ia_iot;
	bus_space_handle_t ioh;
	int rv;

	if (bus_space_map(iot, ia->ia_iobase, WDS_IO_PORTS, 0, &ioh))
		return (0);

	/* See if there is a unit at this location. */
	rv = wds_find(ia, NULL);

	bus_space_unmap(iot, ioh, WDS_IO_PORTS);

	if (rv) {
		ia->ia_msize = 0;
		ia->ia_iosize = WDS_IO_PORTS;
	}

	return (rv);
}

int
wdsprint(void *aux, const char *name)
{
	if (name != NULL)
		printf("%s: scsibus ", name);
	return UNCONF;
}

/*
 * Attach all available units.
 */
void
wdsattach(struct device *parent, struct device *self, void *aux)
{
	struct isa_attach_args *ia = aux;
	struct wds_softc *sc = (void *)self;
	struct scsibus_attach_args saa;
	bus_space_tag_t iot = ia->ia_iot;
	bus_space_handle_t ioh;

	if (bus_space_map(iot, ia->ia_iobase, WDS_IO_PORTS, 0, &ioh)) {
		printf("%s: can't map i/o space\n", sc->sc_dev.dv_xname);
		return;
	}

	if (!wds_find(ia, sc))
		panic("wdsattach: wds_find of %s failed", self->dv_xname);
	wds_init(sc);

	if (sc->sc_drq != DRQUNK)
		isadma_cascade(sc->sc_drq);

	TAILQ_INIT(&sc->sc_free_scb);
	TAILQ_INIT(&sc->sc_waiting_scb);
	mtx_init(&sc->sc_scb_mtx, IPL_BIO);
	scsi_iopool_init(&sc->sc_iopool, sc, wds_scb_alloc, wds_scb_free);

	wds_inquire_setup_information(sc);

	/*
	 * fill in the prototype scsi_link.
	 */
	sc->sc_link.adapter_softc = sc;
	sc->sc_link.adapter_target = sc->sc_scsi_dev;
	sc->sc_link.adapter = &wds_switch;
	/* XXX */
	/* I don't think the -ASE can handle openings > 1. */
	/* It gives Vendor Error 26 whenever I try it.     */
	sc->sc_link.openings = 1;
	sc->sc_link.pool = &sc->sc_iopool;

	sc->sc_ih = isa_intr_establish(ia->ia_ic, sc->sc_irq, IST_EDGE,
	    IPL_BIO, wdsintr, sc, sc->sc_dev.dv_xname);

	bzero(&saa, sizeof(saa));
	saa.saa_sc_link = &sc->sc_link;

	/*
	 * ask the adapter what subunits are present
	 */
	config_found(self, &saa, wdsprint);
}

integrate void
wds_finish_scbs(struct wds_softc *sc)
{
	struct wds_mbx_in *wmbi;
	struct wds_scb *scb;
	int i;

	wmbi = wmbx->tmbi;

	if (wmbi->stat == WDS_MBI_FREE) {
		for (i = 0; i < WDS_MBX_SIZE; i++) {
			if (wmbi->stat != WDS_MBI_FREE) {
				printf("%s: mbi not in round-robin order\n",
				    sc->sc_dev.dv_xname);
				goto AGAIN;
			}
			wds_nextmbx(wmbi, wmbx, mbi);
		}
#ifdef WDSDIAGnot
		printf("%s: mbi interrupt with no full mailboxes\n",
		    sc->sc_dev.dv_xname);
#endif
		return;
	}

AGAIN:
	do {
		scb = wds_scb_phys_kv(sc, phystol(wmbi->scb_addr));
		if (!scb) {
			printf("%s: bad mbi scb pointer; skipping\n",
			    sc->sc_dev.dv_xname);
			goto next;
		}

#ifdef WDSDEBUG
		if (wds_debug) {
			u_int8_t *cp = (u_int8_t *)&scb->cmd.scb;
			printf("op=%x %x %x %x %x %x\n",
			    cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
			printf("stat %x for mbi addr = 0x%08x, ",
			    wmbi->stat, wmbi);
			printf("scb addr = 0x%x\n", scb);
		}
#endif /* WDSDEBUG */

		timeout_del(&scb->xs->stimeout);
		wds_done(sc, scb, wmbi->stat);

	next:
		wmbi->stat = WDS_MBI_FREE;
		wds_nextmbx(wmbi, wmbx, mbi);
	} while (wmbi->stat != WDS_MBI_FREE);

	wmbx->tmbi = wmbi;
}

/*
 * Process an interrupt.
 */
int
wdsintr(void *arg)
{
	struct wds_softc *sc = arg;
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	u_char c;

	/* Was it really an interrupt from the board? */
	if ((bus_space_read_1(iot, ioh, WDS_STAT) & WDSS_IRQ) == 0)
		return 0;

	/* Get the interrupt status byte. */
	c = bus_space_read_1(iot, ioh, WDS_IRQSTAT) & WDSI_MASK;

	/* Acknowledge (which resets) the interrupt. */
	bus_space_write_1(iot, ioh, WDS_IRQACK, 0x00);

	switch (c) {
	case WDSI_MSVC:
		wds_finish_scbs(sc);
		break;

	case WDSI_MFREE:
		wds_start_scbs(sc);
		break;

	default:
		printf("%s: unrecognized interrupt type %02x",
		    sc->sc_dev.dv_xname, c);
		break;
	}

	return 1;
}

integrate void
wds_reset_scb(struct wds_softc *sc, struct wds_scb *scb)
{
	scb->flags = 0;
}

/*
 * Free the command structure, the outgoing mailbox and the data buffer.
 */
void
wds_scb_free(void *xsc, void *xscb)
{
	struct wds_softc *sc = xsc;
	struct wds_scb *scb = xscb;

	if (scb->buf) {
		wds_free_buf(sc, scb->buf);
		scb->buf = NULL;
	}

	wds_reset_scb(sc, scb);
	mtx_enter(&sc->sc_scb_mtx);
	TAILQ_INSERT_HEAD(&sc->sc_free_scb, scb, chain);
	mtx_leave(&sc->sc_scb_mtx);
}

void
wds_free_buf(struct wds_softc *sc, struct wds_buf *buf)
{
	int s;

	s = splbio();

	buf->busy = 0;
	TAILQ_INSERT_HEAD(&wds_free_buffer, buf, chain);

	/*
	 * If there were none, wake anybody waiting for one to come free,
	 * starting with queued entries.
	 */
	if (TAILQ_NEXT(buf, chain) == NULL)
		wakeup(&wds_free_buffer);

	splx(s);
}

integrate void
wds_init_scb(struct wds_softc *sc, struct wds_scb *scb)
{
	int hashnum;

	bzero(scb, sizeof(struct wds_scb));
	/*
	 * put in the phystokv hash table
	 * Never gets taken out.
	 */
	scb->hashkey = KVTOPHYS(scb);
	hashnum = SCB_HASH(scb->hashkey);
	scb->nexthash = sc->sc_scbhash[hashnum];
	sc->sc_scbhash[hashnum] = scb;
	wds_reset_scb(sc, scb);
}

/*
 * Get a free scb
 */
void *
wds_scb_alloc(void *xsc)
{
	struct wds_softc *sc = xsc;
	struct wds_scb *scb;

	mtx_enter(&sc->sc_scb_mtx);
	scb = TAILQ_FIRST(&sc->sc_free_scb);
	if (scb) {
		TAILQ_REMOVE(&sc->sc_free_scb, scb, chain);
		scb->flags |= SCB_ALLOC;
	}
	mtx_leave(&sc->sc_scb_mtx);

	return (scb);
}

struct wds_buf *
wds_get_buf(struct wds_softc *sc, int flags)
{
	struct wds_buf *buf;
	int s;

	s = splbio();

	for (;;) {
		buf = TAILQ_FIRST(&wds_free_buffer);
		if (buf) {
			TAILQ_REMOVE(&wds_free_buffer, buf, chain);
			break;
		}
		if ((flags & SCSI_NOSLEEP) != 0)
			goto out;
		tsleep(&wds_free_buffer, PRIBIO, "wdsbuf", 0);
	}

	buf->busy = 1;

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

struct wds_scb *
wds_scb_phys_kv(struct wds_softc *sc, u_long scb_phys)
{
	int hashnum = SCB_HASH(scb_phys);
	struct wds_scb *scb = sc->sc_scbhash[hashnum];

	while (scb) {
		if (scb->hashkey == scb_phys)
			break;
		/* XXX Check to see if it matches the sense command block. */
		if (scb->hashkey == (scb_phys - sizeof(struct wds_cmd)))
			break;
		scb = scb->nexthash;
	}
	return scb;
}

/*
 * Queue a SCB to be sent to the controller, and send it if possible.
 */
void
wds_queue_scb(struct wds_softc *sc, struct wds_scb *scb)
{
	TAILQ_INSERT_TAIL(&sc->sc_waiting_scb, scb, chain);
	wds_start_scbs(sc);
}

/*
 * Garbage collect mailboxes that are no longer in use.
 */
void
wds_collect_mbo(struct wds_softc *sc)
{
	struct wds_mbx_out *wmbo;	/* Mail Box Out pointer */
#ifdef WDSDIAG
	struct wds_scb *scb;
#endif

	wmbo = wmbx->cmbo;

	while (sc->sc_mbofull > 0) {
		if (wmbo->cmd != WDS_MBO_FREE)
			break;

#ifdef WDSDIAG
		scb = wds_scb_phys_kv(sc, phystol(wmbo->scb_addr));
		scb->flags &= ~SCB_SENDING;
#endif

		--sc->sc_mbofull;
		wds_nextmbx(wmbo, wmbx, mbo);
	}

	wmbx->cmbo = wmbo;
}

/*
 * Send as many SCBs as we have empty mailboxes for.
 */
void
wds_start_scbs(struct wds_softc *sc)
{
	struct wds_mbx_out *wmbo;	/* Mail Box Out pointer */
	struct wds_scb *scb;
	u_char c;

	wmbo = wmbx->tmbo;

	while ((scb = TAILQ_FIRST(&sc->sc_waiting_scb)) != NULL) {
		if (sc->sc_mbofull >= WDS_MBX_SIZE) {
			wds_collect_mbo(sc);
			if (sc->sc_mbofull >= WDS_MBX_SIZE) {
				c = WDSC_IRQMFREE;
				wds_cmd(sc, &c, sizeof c);
				break;
			}
		}

		TAILQ_REMOVE(&sc->sc_waiting_scb, scb, chain);
#ifdef WDSDIAG
		scb->flags |= SCB_SENDING;
#endif
		timeout_set(&scb->xs->stimeout, wds_timeout, scb);

		/* Link scb to mbo. */
		if (scb->flags & SCB_SENSE)
			ltophys(KVTOPHYS(&scb->sense), wmbo->scb_addr);
		else
			ltophys(KVTOPHYS(&scb->cmd), wmbo->scb_addr);
		/* XXX What about aborts? */
		wmbo->cmd = WDS_MBO_START;

		/* Tell the card to poll immediately. */
		c = WDSC_MSTART(wmbo - wmbx->mbo);
		wds_cmd(sc, &c, sizeof c);

		if ((scb->flags & SCB_POLLED) == 0)
			timeout_add_msec(&scb->xs->stimeout, scb->timeout);

		++sc->sc_mbofull;
		wds_nextmbx(wmbo, wmbx, mbo);
	}

	wmbx->tmbo = wmbo;
}

/*
 * Process the result of a SCSI command.
 */
void
wds_done(struct wds_softc *sc, struct wds_scb *scb, u_int8_t stat)
{
	struct scsi_xfer *xs = scb->xs;

	/* XXXXX */

	/* Don't release the SCB if it was an internal command. */
	if (xs == 0) {
		scb->flags |= SCB_DONE;
		return;
	}

	/* Sense handling. */
	if (xs->error == XS_SENSE) {
		bcopy(&scb->sense_data, &xs->sense, sizeof (struct scsi_sense_data));
	} else {
		if (xs->error == XS_NOERROR) {
			/* If all went well, or an error is acceptable. */
			if (stat == WDS_MBI_OK) {
				/* OK, set the result */
				xs->resid = 0;
			} else {
				/* Check the mailbox status. */
				switch (stat) {
				case WDS_MBI_OKERR:
					/* SCSI error recorded in scb, counts as WDS_MBI_OK */
					switch (scb->cmd.venderr) {
					case 0x00:
						printf("%s: Is this an error?\n", sc->sc_dev.dv_xname);
						xs->error = XS_DRIVER_STUFFUP; /* Experiment */
						break;
					case 0x01:
						/*printf("%s: OK, see SCSI error field.\n", sc->sc_dev.dv_xname);*/
						if (scb->cmd.stat == SCSI_CHECK) {
							/* Do sense. */
							wds_sense (sc, scb);
							return;
						} else if (scb->cmd.stat == SCSI_BUSY) {
							xs->error = XS_BUSY;
						}
						break;
					case 0x40:
						/*printf("%s: DMA underrun!\n", sc->sc_dev.dv_xname);*/
						/* Hits this if the target returns fewer that datalen bytes (eg my CD-ROM,
						which returns a short version string, or if DMA is turned off etc. */
						xs->resid = 0;
						break;
					default:
						printf("%s: VENDOR ERROR %02x, scsi %02x\n", sc->sc_dev.dv_xname, scb->cmd.venderr, scb->cmd.stat);
						xs->error = XS_DRIVER_STUFFUP; /* Experiment */
						break;
					}
					break;
				case WDS_MBI_ETIME:
					/*
					 * The documentation isn't clear on
					 * what conditions might generate this,
					 * but selection timeouts are the only
					 * one I can think of.
					 */
					xs->error = XS_SELTIMEOUT;
					break;
				case WDS_MBI_ERESET:
				case WDS_MBI_ETARCMD:
				case WDS_MBI_ERESEL:
				case WDS_MBI_ESEL:
				case WDS_MBI_EABORT:
				case WDS_MBI_ESRESET:
				case WDS_MBI_EHRESET:
					xs->error = XS_DRIVER_STUFFUP;
					break;
				}
			}
		} /* else sense */

		if (NEEDBUFFER(sc) && xs->datalen) {
			if (xs->flags & SCSI_DATA_IN)
				bcopy(scb->buf->data, xs->data, xs->datalen);
		}
	} /* XS_NOERROR */

	scsi_done(xs);
}

int
wds_find(struct isa_attach_args *ia, struct wds_softc *sc)
{
	bus_space_tag_t iot = ia->ia_iot;
	bus_space_handle_t ioh = ia->ia_ioh;
	u_char c;
	int i;

	/*
	 * Sending a command causes the CMDRDY bit to clear.
	 */
	c = bus_space_read_1(iot, ioh, WDS_STAT);
	for (i = 0; i < 4; i++) {
		if ((bus_space_read_1(iot, ioh, WDS_STAT) & WDSS_RDY) != 0)
			goto ready;
		delay(10);
	}
	return (0);

ready:
	bus_space_write_1(iot, ioh, WDS_CMD, WDSC_NOOP);
	if (bus_space_read_1(iot, ioh, WDS_STAT) & WDSS_RDY)
		return (0);

	bus_space_write_1(iot, ioh, WDS_HCR, WDSH_SCSIRESET|WDSH_ASCRESET);
	delay(10000);
	bus_space_write_1(iot, ioh, WDS_HCR, 0x00);
	delay(500000);
	wds_wait(iot, ioh, WDS_STAT, WDSS_RDY, WDSS_RDY);
	if (bus_space_read_1(iot, ioh, WDS_IRQSTAT) != 1)
		if (bus_space_read_1(iot, ioh, WDS_IRQSTAT) != 7)
			printf("%s: failed reset!!! %2x\n",
			    sc ? sc->sc_dev.dv_xname : "wds?",
			    bus_space_read_1(iot, ioh, WDS_IRQSTAT));

	if ((bus_space_read_1(iot, ioh, WDS_STAT) & (WDSS_RDY)) != WDSS_RDY) {
		printf("%s: waiting for controller to become ready.",
		    sc ? sc->sc_dev.dv_xname : "wds?");
		for (i = 0; i < 20; i++) {
			if ((bus_space_read_1(iot, ioh, WDS_STAT) &
			    (WDSS_RDY)) == WDSS_RDY)
				break;
			printf(".");
			delay(10000);
		}
		if ((bus_space_read_1(iot, ioh, WDS_STAT) & (WDSS_RDY)) !=
		    WDSS_RDY) {
			printf(" failed\n");
			return (0);
		}
		printf("\n");
	}

	if (sc != NULL) {
		/* XXX Can we do this better? */
		/* who are we on the scsi bus? */
		sc->sc_scsi_dev = 7;

		sc->sc_iot = iot;
		sc->sc_ioh = ioh;
		sc->sc_irq = ia->ia_irq;
		sc->sc_drq = ia->ia_drq;
	}

	return (1);
}

/*
 * Initialise the board and driver.
 */
void
wds_init(struct wds_softc *sc)
{
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	struct wds_setup init;
	u_char c;
	int i;

	/*
	 * Set up initial mail box for round-robin operation.
	 */
	for (i = 0; i < WDS_MBX_SIZE; i++) {
		wmbx->mbo[i].cmd = WDS_MBO_FREE;
		wmbx->mbi[i].stat = WDS_MBI_FREE;
	}
	wmbx->cmbo = wmbx->tmbo = &wmbx->mbo[0];
	wmbx->tmbi = &wmbx->mbi[0];
	sc->sc_mbofull = 0;

	/* Clear the buffers. */
	TAILQ_INIT(&wds_free_buffer);
	for (i = 0; i < BUFCNT; i++) {
		wds_buffer[i].busy = 0;
		TAILQ_INSERT_HEAD(&wds_free_buffer, &wds_buffer[i], chain);
	}

	init.opcode = WDSC_INIT;
	init.scsi_id = sc->sc_scsi_dev;
	/* Record scsi id of controller for use in scsi_attach */
	sc->sc_scsi_dev = init.scsi_id;
	init.buson_t = 48;
	init.busoff_t = 24;
	init.xx = 0;
	ltophys(KVTOPHYS(wmbx), init.mbaddr);
	init.nomb = init.nimb = WDS_MBX_SIZE;
	wds_cmd(sc, (u_char *)&init, sizeof init);

	wds_wait(iot, ioh, WDS_STAT, WDSS_INIT, WDSS_INIT);

	c = WDSC_DISUNSOL;
	wds_cmd(sc, &c, sizeof c);

	bus_space_write_1(iot, ioh, WDS_HCR, WDSH_DRQEN);
}

/*
 * Read the board's firmware revision information.
 */
void
wds_inquire_setup_information(struct wds_softc *sc)
{
	struct wds_scb *scb;
	u_char *j;
	int s;

	scb = scsi_io_get(&sc->sc_iopool, SCSI_NOSLEEP);
	if (scb == NULL) {
		printf("%s: no request slot available in getvers()!\n",
		    sc->sc_dev.dv_xname);
		return;
	}
	scb->xs = NULL;
	scb->timeout = 40;

	bzero(&scb->cmd, sizeof scb->cmd);
	scb->cmd.write = 0x80;
	scb->cmd.opcode = WDSX_GETFIRMREV;

	/* Will poll card, await result. */
	bus_space_write_1(sc->sc_iot, sc->sc_ioh, WDS_HCR, WDSH_DRQEN);
	scb->flags |= SCB_POLLED;

	s = splbio();
	wds_queue_scb(sc, scb);
	splx(s);

	if (wds_ipoll(sc, scb, scb->timeout))
		goto out;

	/* Print the version number. */
	printf(": version %x.%02x ", scb->cmd.targ, scb->cmd.scb.opcode);
	sc->sc_revision = (scb->cmd.targ << 8) | scb->cmd.scb.opcode;
	/* Print out the version string. */
	j = 2 + &(scb->cmd.targ);
	while ((*j >= 32) && (*j < 128)) {
		printf("%c", *j);
		j++;
	}

out:
	printf("\n");
	scsi_io_put(&sc->sc_iopool, scb);
}

void
wdsminphys(struct buf *bp, struct scsi_link *sl)
{
	if (bp->b_bcount > ((WDS_NSEG - 1) << PGSHIFT))
		bp->b_bcount = ((WDS_NSEG - 1) << PGSHIFT);
	minphys(bp);
}

/*
 * Send a SCSI command.
 */
void
wds_scsi_cmd(struct scsi_xfer *xs)
{
	struct scsi_link *sc_link = xs->sc_link;
	struct wds_softc *sc = sc_link->adapter_softc;
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	struct wds_scb *scb;
	struct wds_scat_gath *sg;
	int seg;
	u_long thiskv, thisphys, nextphys;
	int bytes_this_seg, bytes_this_page, datalen, flags;
	int s;

	if (xs->flags & SCSI_RESET) {
		/* XXX Fix me! */
		printf("%s: reset!\n", sc->sc_dev.dv_xname);
		wds_init(sc);
		scsi_done(xs);
		return;
	}

	flags = xs->flags;
	scb = xs->io;
	scb->xs = xs;
	scb->timeout = xs->timeout;

	/* Zero out the command structure. */
	bzero(&scb->cmd, sizeof scb->cmd);
	bcopy(xs->cmd, &scb->cmd.scb, xs->cmdlen < 12 ? xs->cmdlen : 12);

	/* Set up some of the command fields. */
	scb->cmd.targ = (xs->sc_link->target << 5) | xs->sc_link->lun;

	/* NOTE: cmd.write may be OK as 0x40 (disable direction checking)
	 * on boards other than the WD-7000V-ASE. Need this for the ASE:
	 */
	scb->cmd.write = (xs->flags & SCSI_DATA_IN) ? 0x80 : 0x00;

	if (!NEEDBUFFER(sc) && xs->datalen) {
		sg = scb->scat_gath;
		seg = 0;

		/*
		 * Set up the scatter-gather block.
		 */
		SC_DEBUG(sc_link, SDEV_DB4,
		    ("%d @0x%x:- ", xs->datalen, xs->data));

		datalen = xs->datalen;
		thiskv = (int)xs->data;
		thisphys = KVTOPHYS(xs->data);

		while (datalen && seg < WDS_NSEG) {
			bytes_this_seg = 0;

			/* put in the base address */
			ltophys(thisphys, sg->seg_addr);

			SC_DEBUGN(sc_link, SDEV_DB4, ("0x%x", thisphys));

			/* do it at least once */
			nextphys = thisphys;
			while (datalen && thisphys == nextphys) {
				/*
				 * This page is contiguous (physically)
				 * with the last, just extend the
				 * length
				 */
				/* check it fits on the ISA bus */
				if (thisphys > 0xFFFFFF) {
					printf("%s: DMA beyond"
						" end of ISA\n",
						sc->sc_dev.dv_xname);
					goto bad;
				}
				/* how far to the end of the page */
				nextphys = (thisphys & ~PGOFSET) + NBPG;
				bytes_this_page = nextphys - thisphys;
				/**** or the data ****/
				bytes_this_page = min(bytes_this_page,
						      datalen);
				bytes_this_seg += bytes_this_page;
				datalen -= bytes_this_page;

				/* get more ready for the next page */
				thiskv = (thiskv & ~PGOFSET) + NBPG;
				if (datalen)
					thisphys = KVTOPHYS(thiskv);
			}
			/*
			 * next page isn't contiguous, finish the seg
			 */
			SC_DEBUGN(sc_link, SDEV_DB4,
			    ("(0x%x)", bytes_this_seg));
			ltophys(bytes_this_seg, sg->seg_len);
			sg++;
			seg++;
		}

		SC_DEBUGN(sc_link, SDEV_DB4, ("\n"));
		if (datalen) {
			/*
			 * there's still data, must have run out of segs!
			 */
			printf("%s: wds_scsi_cmd, more than %d dma segs\n",
			    sc->sc_dev.dv_xname, WDS_NSEG);
			goto bad;
		}
		scb->cmd.opcode = WDSX_SCSISG;
		ltophys(KVTOPHYS(scb->scat_gath), scb->cmd.data);
		ltophys(seg * sizeof(struct wds_scat_gath), scb->cmd.len);
	} else if (xs->datalen > 0) {
		/* The board is an ASC or ASE. Do not use scatter/gather. */
		if (xs->datalen > BUFLEN) {
			printf("%s: wds_scsi_cmd, I/O too large for bounce buffer\n",
			    sc->sc_dev.dv_xname);
			goto bad;
		}
		if (xs->flags & SCSI_DATA_OUT)
			bcopy(xs->data, scb->buf->data, xs->datalen);
		else
			bzero(scb->buf->data, xs->datalen);
		scb->cmd.opcode = WDSX_SCSICMD;
		ltophys(KVTOPHYS(scb->buf->data), scb->cmd.data);
		ltophys(xs->datalen, scb->cmd.len);
	} else {
		scb->cmd.opcode = WDSX_SCSICMD;
		ltophys(0, scb->cmd.data);
		ltophys(0, scb->cmd.len);
	}

	scb->cmd.stat = 0x00;
	scb->cmd.venderr = 0x00;
	ltophys(0, scb->cmd.link);

	/* XXX Do we really want to do this? */
	if (flags & SCSI_POLL) {
		/* Will poll card, await result. */
		bus_space_write_1(iot, ioh, WDS_HCR, WDSH_DRQEN);
		scb->flags |= SCB_POLLED;
	} else {
		/* Will send command, let interrupt routine handle result. */
		bus_space_write_1(iot, ioh, WDS_HCR, WDSH_IRQEN | WDSH_DRQEN);
	}

	s = splbio();
	wds_queue_scb(sc, scb);

	splx(s);

	if ((flags & SCSI_POLL) == 0)
		return;

	if (wds_poll(sc, xs, scb->timeout)) {
		wds_timeout(scb);
		if (wds_poll(sc, xs, scb->timeout))
			wds_timeout(scb);
	}
	return;

bad:
	xs->error = XS_DRIVER_STUFFUP;
}

/*
 * Send a sense request.
 */
void
wds_sense(struct wds_softc *sc, struct wds_scb *scb)
{
	struct scsi_xfer *xs = scb->xs;
	struct scsi_sense *ss = (void *)&scb->sense.scb;
	int s;

	/* XXXXX */

	/* Send sense request SCSI command. */
	xs->error = XS_SENSE;
	scb->flags |= SCB_SENSE;

	/* First, save the return values */
	if (NEEDBUFFER(sc) && xs->datalen) {
		if (xs->flags & SCSI_DATA_IN)
			bcopy(scb->buf->data, xs->data, xs->datalen);
	}

	/* Next, setup a request sense command block */
	bzero(ss, sizeof(*ss));
	ss->opcode = REQUEST_SENSE;
	ss->byte2 = xs->sc_link->lun << 5;
	ss->length = sizeof(struct scsi_sense_data);

	/* Set up some of the command fields. */
	scb->sense.targ = scb->cmd.targ;
	scb->sense.write = 0x80;
	scb->sense.opcode = WDSX_SCSICMD;
	ltophys(KVTOPHYS(&scb->sense_data), scb->sense.data);
	ltophys(sizeof(struct scsi_sense_data), scb->sense.len);

	s = splbio();
	wds_queue_scb(sc, scb);
	splx(s);

	/*
	 * There's no reason for us to poll here.  There are two cases:
	 * 1) If it's a polling operation, then we're called from the interrupt
	 *    handler, and we return and continue polling.
	 * 2) If it's an interrupt-driven operation, then it gets completed
	 *    later on when the REQUEST SENSE finishes.
	 */
}

/*
 * Poll a particular unit, looking for a particular scb
 */
int
wds_poll(struct wds_softc *sc, struct scsi_xfer *xs,  int count)
{
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	int s;

	/* 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, WDS_STAT) & WDSS_IRQ) {
			s = splbio();
			wdsintr(sc);
			splx(s);
		}
		if (xs->flags & ITSDONE)
			return 0;
		delay(1000);	/* only happens in boot so ok */
		count--;
	}
	return 1;
}

/*
 * Poll a particular unit, looking for a particular scb
 */
int
wds_ipoll(struct wds_softc *sc, struct wds_scb *scb, int count)
{
	bus_space_tag_t iot = sc->sc_iot;
	bus_space_handle_t ioh = sc->sc_ioh;
	int s;

	/* 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, WDS_STAT) & WDSS_IRQ) {
			s = splbio();
			wdsintr(sc);
			splx(s);
		}
		if (scb->flags & SCB_DONE)
			return 0;
		delay(1000);	/* only happens in boot so ok */
		count--;
	}
	return 1;
}

void
wds_timeout(void *arg)
{
	struct wds_scb *scb = arg;
	struct scsi_xfer *xs;
	struct scsi_link *sc_link;
	struct wds_softc *sc;
	int s;

	s = splbio();
	xs = scb->xs;
	sc_link = xs->sc_link;
	sc = sc_link->adapter_softc;

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

#ifdef WDSDIAG
	/*
	 * If The scb's mbx is not free, then the board has gone south?
	 */
	wds_collect_mbo(sc);
	if (scb->flags & SCB_SENDING)
		panic("%s: not taking commands!", sc->sc_dev.dv_xname);
#endif

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

	splx(s);
}