FreeBSD-5.3/sys/pc98/pc98/wd.c

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/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	from: @(#)wd.c	7.2 (Berkeley) 5/9/91
 * $FreeBSD: src/sys/pc98/pc98/wd.c,v 1.137 2004/04/07 04:59:58 imp Exp $
 */

/* TODO:
 *	o Bump error count after timeout.
 *	o Satisfy ATA timing in all cases.
 *	o Finish merging berry/sos timeout code (bump error count...).
 *	o Don't use polling except for initialization.  Need to
 *	  reorganize the state machine.  Then "extra" interrupts
 *	  shouldn't happen (except maybe one for initialization).
 *	o Support extended DOS partitions.
 *	o Support swapping to DOS partitions.
 *	o Handle bad sectors, clustering, disklabelling, DOS
 *	  partitions and swapping driver-independently.  Use
 *	  i386/dkbad.c for bad sectors.  Swapping will need new
 *	  driver entries for polled reinit and polled write).
 */

#include "wdc.h"
#undef NWD
#define NWD (NWDC * 4)		/* 4 drives per wdc on PC98 */

#if     NWDC > 0

#include "opt_hw_wdog.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/disk.h>
#include <geom/geom_disk.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <machine/bootinfo.h>
#include <sys/cons.h>
#include <machine/md_var.h>
#ifdef PC98
#include <pc98/pc98/pc98.h>
#include <pc98/pc98/pc98_machdep.h>
#include <pc98/pc98/epsonio.h>
#else
#include <i386/isa/isa.h>
#endif
#include <i386/isa/isa_device.h>
#include <pc98/pc98/wdreg.h>
#include <sys/syslog.h>
#include <vm/vm.h>
#include <vm/pmap.h>

#include <pc98/pc98/atapi.h>

#ifndef COMPAT_OLDISA
#error "The wdc device requires the old isa compatibility shims"
#endif

extern void wdstart(int ctrlr);

#ifdef IDE_DELAY
#define TIMEOUT		IDE_DELAY
#else
#define TIMEOUT		10000
#endif
#define	RETRIES		5	/* number of retries before giving up */
#define RECOVERYTIME	500000	/* usec for controller to recover after err */
#define	MAXTRANSFER	255	/* max size of transfer in sectors */
				/* correct max is 256 but some controllers */
				/* can't handle that in all cases */
#define WDOPT_32BIT	0x8000
#define WDOPT_SLEEPHACK	0x4000
#define WDOPT_DMA	0x2000
#define WDOPT_LBA	0x1000
#define WDOPT_FORCEHD(x)	(((x)&0x0f00)>>8)
#define WDOPT_MULTIMASK	0x00ff

#ifdef PC98
static __inline u_char
epson_errorf(int wdc)
{
	u_char  wdc_error;

	outb(wdc, inb(0x82) | 0x40);
	wdc_error = (u_char)epson_inb(wdc);
	outb(wdc, inb(0x82) & ~0x40);
	return ((u_char)wdc_error);
}
#endif

/*
 * Drive states.  Used to initialize drive.
 */

#define	CLOSED		0	/* disk is closed. */
#define	WANTOPEN	1	/* open requested, not started */
#define	RECAL		2	/* doing restore */
#define	OPEN		3	/* done with open */

#define PRIMARY		0

/*
 * Disk geometry.  A small part of struct disklabel.
 * XXX disklabel.5 contains an old clone of disklabel.h.
 */
struct diskgeom {
	u_long	d_secsize;		/* # of bytes per sector */
	u_long	d_nsectors;		/* # of data sectors per track */
	u_long	d_ntracks;		/* # of tracks per cylinder */
	u_long	d_ncylinders;		/* # of data cylinders per unit */
	u_long	d_secpercyl;		/* # of data sectors per cylinder */
	u_long	d_secperunit;		/* # of data sectors per unit */
	u_long	d_precompcyl;		/* XXX always 0 */
};

/*
 * The structure of a disk drive.
 */
struct softc {
	u_int	dk_bc;		/* byte count left */
	short	dk_skip;	/* blocks already transferred */
	int	dk_ctrlr;	/* physical controller number */
	int	dk_ctrlr_cmd640;/* controller number for CMD640 quirk */
	u_int32_t	dk_unit;	/* physical unit number */
	u_int32_t	dk_lunit;	/* logical unit number */
	u_int32_t	dk_interface;	/* interface (two ctrlrs per interface) */
	char	dk_state;	/* control state */
	u_char	dk_status;	/* copy of status reg. */
	u_char	dk_error;	/* copy of error reg. */
	u_char	dk_timeout;	/* countdown to next timeout */
	u_int32_t	dk_port;	/* i/o port base */
	u_int32_t	dk_altport;	/* altstatus port base */
	u_long	cfg_flags;	/* configured characteristics */
	short	dk_flags;	/* drive characteristics found */
#define	DKFL_SINGLE	0x00004	/* sector at a time mode */
#define	DKFL_ERROR	0x00008	/* processing a disk error */
#define	DKFL_LABELLING	0x00080	/* readdisklabel() in progress */
#define	DKFL_32BIT	0x00100	/* use 32-bit i/o mode */
#define	DKFL_MULTI	0x00200	/* use multi-i/o mode */
#define	DKFL_BADSCAN	0x00400	/* report all errors */
#define DKFL_USEDMA	0x00800	/* use DMA for data transfers */
#define DKFL_DMA	0x01000 /* using DMA on this transfer-- DKFL_SINGLE
				 * overrides this
				 */
#define DKFL_LBA	0x02000	/* use LBA for data transfers */
	struct wdparams dk_params; /* ESDI/IDE drive/controller parameters */
	unsigned int	dk_multi;	/* multi transfers */
	int	dk_currentiosize;	/* current io size */
	struct diskgeom dk_dd;	/* device configuration data */
	struct diskslices *dk_slices;	/* virtual drives */
	void	*dk_dmacookie;	/* handle for DMA services */
	struct disk *disk;
};

#define WD_COUNT_RETRIES
static int wdtest = 0;

static struct softc *wddrives[NWD];	/* table of units */
static struct bio_queue_head drive_queue[NWD];	/* head of queue per drive */
static struct {
	int	b_active;
} wdutab[NWD];
/*
static struct bio wdtab[NWDC];
*/
static struct {
	struct	bio_queue_head controller_queue;
	int	b_errcnt;
	int	b_active;
} wdtab[NWDC];

struct wddma wddma[NWDC];

#ifdef notyet
static struct bio rwdbuf[NWD];	/* buffers for raw IO */
#endif
#ifdef PC98
static short wd_ctlr;
static int old_epson_note;
#endif

static int wdprobe(struct isa_device *dvp);
static int wdattach(struct isa_device *dvp);
static void wdustart(struct softc *du);
static int wdcontrol(struct bio *bp);
static int wdcommand(struct softc *du, u_int cylinder, u_int head,
		     u_int sector, u_int count, u_int command);
static int wdsetctlr(struct softc *du);
#if 0
static int wdwsetctlr(struct softc *du);
#endif
static int wdsetmode(int mode, void *wdinfo);
static int wdgetctlr(struct softc *du);
static void wderror(struct bio *bp, struct softc *du, char *mesg);
static void wdflushirq(struct softc *du, int old_ipl);
static int wdreset(struct softc *du);
static void wdsleep(int ctrlr, char *wmesg);
static disk_open_t wdopen;
static disk_strategy_t wdstrategy;
static timeout_t wdtimeout;
static int wdunwedge(struct softc *du);
static int wdwait(struct softc *du, u_char bits_wanted, int timeout);

struct isa_driver wdcdriver = {
	INTR_TYPE_BIO,
	wdprobe,
	wdattach,
	"wdc",
};
COMPAT_ISA_DRIVER(wdc, wdcdriver);

static int      atapictrlr;
static int      eide_quirks;


/*
 *  Here we use the pci-subsystem to find out, whether there is
 *  a cmd640b-chip attached on this pci-bus. This public routine
 *  will be called by ide_pci.c
 */

void
wdc_pci(int quirks)
{
	eide_quirks = quirks;
}

/*
 * Probe for controller.
 */
static int
wdprobe(struct isa_device *dvp)
{
	int	unit = dvp->id_unit;
	int	interface;
	struct softc *du;

	if (unit >= NWDC)
		return (0);

	du = malloc(sizeof *du, M_TEMP, M_NOWAIT | M_ZERO);
	if (du == NULL)
		return (0);
	du->dk_ctrlr = dvp->id_unit;
	interface = du->dk_ctrlr / 2;
	du->dk_interface = interface;
	du->dk_port = dvp->id_iobase;
	if (wddma[interface].wdd_candma != NULL) {
		du->dk_dmacookie =
		    wddma[interface].wdd_candma(dvp->id_iobase, du->dk_ctrlr,
		    du->dk_unit);
		du->dk_altport =
		    wddma[interface].wdd_altiobase(du->dk_dmacookie);
	}
	if (du->dk_altport == 0)
		du->dk_altport = du->dk_port + wd_ctlr;

	/* check if we have registers that work */
#ifdef PC98
	/* XXX ATAPI support isn't imported */
	wd_ctlr = wd_ctlr_nec;		/* wdreg.h */
	old_epson_note=0;

	if (pc98_machine_type & M_EPSON_PC98 ) {
	    switch (epson_machine_id) {
	      case 0x20: case 0x22: case 0x2a:	/* note A/W/WR */
		du->dk_port = IO_WD1_EPSON;	/* pc98.h */
		dvp->id_iobase = IO_WD1_EPSON;	/* pc98.h */
		wd_ctlr = wd_ctlr_epson;	/* wdreg.h */
		old_epson_note = 1;		/* for OLD EPSON NOTE */
		break;
	      default:
		break;
	    }
	}
	du->dk_altport = du->dk_port + wd_ctlr;
#if 0
	if ((PC98_SYSTEM_PARAMETER(0x55d) & 3) == 0) {
		goto nodevice;
	}
#endif
	outb(0x432,(du->dk_unit)%2);
#else /* IBM-PC */
	outb(du->dk_port + wd_sdh, WDSD_IBM);   /* set unit 0 */
	outb(du->dk_port + wd_cyl_lo, 0xa5);	/* wd_cyl_lo is read/write */
	if (inb(du->dk_port + wd_cyl_lo) == 0xff) {     /* XXX too weak */
		/* There is no master, try the ATAPI slave. */
		du->dk_unit = 1;
		outb(du->dk_port + wd_sdh, WDSD_IBM | 0x10);
		outb(du->dk_port + wd_cyl_lo, 0xa5);
		if (inb(du->dk_port + wd_cyl_lo) == 0xff)
			goto nodevice;
	}
#endif /* PC98 */

	if (wdreset(du) == 0)
		goto reset_ok;
	/* test for ATAPI signature */
	outb(du->dk_port + wd_sdh, WDSD_IBM);           /* master */
	if (inb(du->dk_port + wd_cyl_lo) == 0x14 &&
	    inb(du->dk_port + wd_cyl_hi) == 0xeb)
		goto reset_ok;
#ifdef PC98
	du->dk_unit = 2;
#else
	du->dk_unit = 1;
#endif
	outb(du->dk_port + wd_sdh, WDSD_IBM | 0x10); /* slave */
	if (inb(du->dk_port + wd_cyl_lo) == 0x14 &&
	    inb(du->dk_port + wd_cyl_hi) == 0xeb)
		goto reset_ok;
#ifdef PC98
	du->dk_unit = 1;
	outb(0x432,(du->dk_unit)%2);
	if (wdreset(du) == 0)
	        goto reset_ok;
	/* test for ATAPI signature */
	outb(du->dk_port + wd_sdh, WDSD_IBM);           /* master */
	if (inb(du->dk_port + wd_cyl_lo) == 0x14 &&
	    inb(du->dk_port + wd_cyl_hi) == 0xeb)
		goto reset_ok;
	du->dk_unit = 3;
	outb(du->dk_port + wd_sdh, WDSD_IBM | 0x10); /* slave */
	if (inb(du->dk_port + wd_cyl_lo) == 0x14 &&
	    inb(du->dk_port + wd_cyl_hi) == 0xeb)
		goto reset_ok;
#endif
	DELAY(RECOVERYTIME);
	if (wdreset(du) != 0) {
		goto nodevice;
	}
reset_ok:

	/* execute a controller only command */
	if (wdcommand(du, 0, 0, 0, 0, WDCC_DIAGNOSE) != 0
	    || wdwait(du, 0, TIMEOUT) < 0) {
		goto nodevice;
	}

	/*
	 * drive(s) did not time out during diagnostic :
	 * Get error status and check that both drives are OK.
	 * Table 9-2 of ATA specs suggests that we must check for
	 * a value of 0x01
	 *
	 * Strangely, some controllers will return a status of
	 * 0x81 (drive 0 OK, drive 1 failure), and then when
	 * the DRV bit is set, return status of 0x01 (OK) for
	 * drive 2.  (This seems to contradict the ATA spec.)
	 */
	if (old_epson_note)
		du->dk_error = epson_errorf(du->dk_port + wd_error);
	else
		du->dk_error = inb(du->dk_port + wd_error);

	if(du->dk_error != 0x01 && du->dk_error != 0) {
		if(du->dk_error & 0x80) { /* drive 1 failure */

			/* first set the DRV bit */
			u_int sdh;
			if (old_epson_note)
				sdh = epson_inb(du->dk_port+ wd_sdh);
			else
				sdh = inb(du->dk_port+ wd_sdh);
			sdh = sdh | 0x10;
			if (old_epson_note)
				epson_outb(du->dk_port+ wd_sdh, sdh);
			else
				outb(du->dk_port+ wd_sdh, sdh);

			/* Wait, to make sure drv 1 has completed diags */
			if ( wdwait(du, 0, TIMEOUT) < 0)
				goto nodevice;

			/* Get status for drive 1 */
			if (old_epson_note)
				du->dk_error = 
					epson_errorf(du->dk_port + wd_error); 
			else
				du->dk_error = inb(du->dk_port + wd_error); 
			/* printf("Error (drv 1) : %x\n", du->dk_error); */
			/*
			 * Sometimes (apparently mostly with ATAPI
			 * drives involved) 0x81 really means 0x81
			 * (drive 0 OK, drive 1 failed).
			 */
			if(du->dk_error != 0x01 && du->dk_error != 0x81)
				goto nodevice;
		} else	/* drive 0 fail */
			goto nodevice;
	}


	free(du, M_TEMP);
	return (IO_WDCSIZE);

nodevice:
	free(du, M_TEMP);
	return (0);
}

/*
 * Attach each drive if possible.
 */
static int
wdattach(struct isa_device *dvp)
{
	int	unit, lunit, flags, i;
	struct softc *du;
	struct wdparams *wp;
	static char buf[] = "wdcXXX";
	const char *dname;

	dvp->id_intr = wdintr;

	if (dvp->id_unit >= NWDC)
		return (0);

	if (eide_quirks & Q_CMD640B) {
		if (dvp->id_unit == PRIMARY) {
			printf("wdc0: CMD640B workaround enabled\n");
			bioq_init(&wdtab[PRIMARY].controller_queue);
		}
	} else
		bioq_init(&wdtab[dvp->id_unit].controller_queue);

	sprintf(buf, "wdc%d", dvp->id_unit);
	i = 0;
	while ((resource_find_match(&i, &dname, &lunit, "at", buf)) == 0) {
		if (strcmp(dname, "wd"))
			/* Avoid a bit of foot shooting. */
			continue;

		if (lunit >= NWD)
			continue;
#ifdef PC98
		if ((lunit%2)!=0) {
			if ((PC98_SYSTEM_PARAMETER(0x457) & 0x40)==0) {
				continue;
			}
		}
#endif

		if (resource_int_value("wd", lunit, "drive", &unit) != 0)
			continue;
		if (resource_int_value("wd", lunit, "flags", &flags) != 0)
			flags = 0;

		du = malloc(sizeof *du, M_TEMP, M_NOWAIT | M_ZERO);
		if (du == NULL)
			continue;
		if (wddrives[lunit] != NULL)
			panic("drive attached twice");
		wddrives[lunit] = du;
		bioq_init(&drive_queue[lunit]);
		du->dk_ctrlr = dvp->id_unit;
		if (eide_quirks & Q_CMD640B) {
			du->dk_ctrlr_cmd640 = PRIMARY;
		} else {
			du->dk_ctrlr_cmd640 = du->dk_ctrlr;
		}
		du->dk_unit = unit;
		du->dk_lunit = lunit;
		du->dk_port = dvp->id_iobase;

		du->dk_altport = du->dk_port + wd_ctlr;
		/*
		 * Use the individual device flags or the controller
		 * flags.
		 */
		du->cfg_flags = flags |
			((dvp->id_flags) >> (16 * unit));

		if (wdgetctlr(du) == 0) {
			/*
			 * Print out description of drive.
			 * wdp_model may not be null terminated.
			 */
			printf("wdc%d: unit %d (wd%d): <%.*s>",
				dvp->id_unit, unit, lunit,
				(int)sizeof(du->dk_params.wdp_model),
				du->dk_params.wdp_model);
			if (du->dk_flags & DKFL_LBA)
				printf(", LBA");
			if (du->dk_flags & DKFL_USEDMA)
				printf(", DMA");
			if (du->dk_flags & DKFL_32BIT)
				printf(", 32-bit");
			if (du->dk_multi > 1)
				printf(", multi-block-%d", du->dk_multi);
			if (du->cfg_flags & WDOPT_SLEEPHACK)
				printf(", sleep-hack");
			printf("\n");
			if (du->dk_params.wdp_heads == 0)
				printf("wd%d: size unknown, using %s values\n",
				       lunit, du->dk_dd.d_secperunit > 17
					      ? "BIOS" : "fake");
			printf( "wd%d: %luMB (%lu sectors), "
				"%lu cyls, %lu heads, %lu S/T, %lu B/S\n",
			       lunit,
			       du->dk_dd.d_secperunit
			       / ((1024L * 1024L) / du->dk_dd.d_secsize),
			       du->dk_dd.d_secperunit,
			       du->dk_dd.d_ncylinders,
			       du->dk_dd.d_ntracks,
			       du->dk_dd.d_nsectors,
			       du->dk_dd.d_secsize);

			if (bootverbose) {
			    wp = &du->dk_params;
			    printf( "wd%d: ATA INQUIRE valid = %04x, "
				    "dmamword = %04x, apio = %04x, "
				    "udma = %04x\n",
				du->dk_lunit,
				wp->wdp_atavalid,
				wp->wdp_dmamword,
				wp->wdp_eidepiomodes,
				wp->wdp_udmamode);
			  }

			/*
			 * Start timeout routine for this drive.
			 * XXX timeout should be per controller.
			 */
			wdtimeout(du);

			/*
			 * Register this media as a disk
			 */
			du->disk = disk_alloc();
			du->disk->d_open = wdopen;
			du->disk->d_strategy = wdstrategy;
			du->disk->d_drv1 = du;
			du->disk->d_maxsize = 248 * 512;
			du->disk->d_name = "wd";
			du->disk->d_unit = lunit;
			du->disk->d_flags = DISKFLAG_NEEDSGIANT;
			disk_create(du->disk, DISK_VERSION);
			
		} else {
			free(du, M_TEMP);
			wddrives[lunit] = NULL;
		}
	}
	/*
	 * Probe all free IDE units, searching for ATAPI drives.
	 */
#ifdef PC98
	for (unit=0; unit<4; ++unit) {
		outb(0x432,unit%2);
#else
	for (unit=0; unit<2; ++unit) {
#endif /* PC98 */
		for (lunit=0; lunit<NWD; ++lunit)
			if (wddrives[lunit] &&
			    wddrives[lunit]->dk_ctrlr == dvp->id_unit &&
			    wddrives[lunit]->dk_unit == unit)
				goto next;
		if (atapi_attach (dvp->id_unit, unit, dvp->id_iobase))
			atapictrlr = dvp->id_unit;
next: ;
	}
	/*
	 * Discard any interrupts generated by wdgetctlr().  wdflushirq()
	 * doesn't work now because the ambient ipl is too high.
	 */
	if (eide_quirks & Q_CMD640B) {
		wdtab[PRIMARY].b_active = 2;
	} else {
		wdtab[dvp->id_unit].b_active = 2;
	}

	return (1);
}

/* Read/write routine for a buffer.  Finds the proper unit, range checks
 * arguments, and schedules the transfer.  Does not wait for the transfer
 * to complete.  Multi-page transfers are supported.  All I/O requests must
 * be a multiple of a sector in length.
 */
void
wdstrategy(struct bio *bp)
{
	struct softc *du;
	int	lunit;
	int	s;

	du = bp->bio_disk->d_drv1;
	if (du == NULL ||  bp->bio_pblkno < 0 ||
	    bp->bio_bcount % DEV_BSIZE != 0) {

		bp->bio_error = EINVAL;
		bp->bio_flags |= BIO_ERROR;
		goto done;
	}
	lunit = du->dk_lunit;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

	/* queue transfer on drive, activate drive and controller if idle */
	s = splbio();

	/* Pick up changes made by readdisklabel(). */
	if (du->dk_flags & DKFL_LABELLING && du->dk_state > RECAL) {
		wdsleep(du->dk_ctrlr, "wdlab");
		du->dk_state = WANTOPEN;
	}

	bioq_disksort(&drive_queue[lunit], bp);

	if (wdutab[lunit].b_active == 0)
		wdustart(du);	/* start drive */

	if (wdtab[du->dk_ctrlr_cmd640].b_active == 0)
		wdstart(du->dk_ctrlr);	/* start controller */

	splx(s);
	return;

done:
	/* toss transfer, we're done early */
	biodone(bp);
}

/*
 * Routine to queue a command to the controller.  The unit's
 * request is linked into the active list for the controller.
 * If the controller is idle, the transfer is started.
 */
static void
wdustart(register struct softc *du)
{
	register struct bio *bp;
	int	ctrlr = du->dk_ctrlr_cmd640;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif
	/* unit already active? */
	if (wdutab[du->dk_lunit].b_active)
		return;


	bp = bioq_first(&drive_queue[du->dk_lunit]);
	if (bp == NULL) {	/* yes, an assign */
		return;
	}
	/*
	 * store away which device we came from.
	 */
	bp->bio_driver1 = du;

	bioq_remove(&drive_queue[du->dk_lunit], bp);

	/* link onto controller queue */
	bioq_insert_tail(&wdtab[ctrlr].controller_queue, bp);

	/* mark the drive unit as busy */
	wdutab[du->dk_lunit].b_active = 1;

}

/*
 * Controller startup routine.  This does the calculation, and starts
 * a single-sector read or write operation.  Called to start a transfer,
 * or from the interrupt routine to continue a multi-sector transfer.
 * RESTRICTIONS:
 * 1. The transfer length must be an exact multiple of the sector size.
 */

void
wdstart(int ctrlr)
{
	register struct softc *du;
	register struct bio *bp;
	struct diskgeom *lp;	/* XXX sic */
	long	blknum;
	long	secpertrk, secpercyl;
	u_int	lunit;
	u_int	count;
	int	ctrlr_atapi;

	if (eide_quirks & Q_CMD640B) {
		ctrlr = PRIMARY;
		ctrlr_atapi = atapictrlr;
	} else {
		ctrlr_atapi = ctrlr;
	}

	if (wdtab[ctrlr].b_active == 2)
		wdtab[ctrlr].b_active = 0;
	if (wdtab[ctrlr].b_active)
		return;
	/* is there a drive for the controller to do a transfer with? */
	bp = bioq_first(&wdtab[ctrlr].controller_queue);
	if (bp == NULL) {
		if (atapi_start && atapi_start (ctrlr_atapi))
			/* mark controller active in ATAPI mode */
			wdtab[ctrlr].b_active = 3;
		return;
	}

	/* obtain controller and drive information */
	du = bp->bio_dev->si_drv1;
	lunit = du->dk_lunit;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

	/* if not really a transfer, do control operations specially */
	if (du->dk_state < OPEN) {
		if (du->dk_state != WANTOPEN)
			printf("wd%d: wdstart: weird dk_state %d\n",
			       du->dk_lunit, du->dk_state);
		if (wdcontrol(bp) != 0)
			printf("wd%d: wdstart: wdcontrol returned nonzero, state = %d\n",
			       du->dk_lunit, du->dk_state);
		return;
	}

	/* calculate transfer details */
	blknum = bp->bio_pblkno + du->dk_skip;
#ifdef WDDEBUG
	if (du->dk_skip == 0)
		printf("wd%d: wdstart: %s %d@%d; map ", lunit,
		       (bp->bio_cmd == BIO_READ) ? "read" : "write",
		       bp->bio_bcount, blknum);
	else {
		if (old_epson_note)
			printf(" %d)%x", du->dk_skip, epson_inb(du->dk_altport);
		else
			printf(" %d)%x", du->dk_skip, inb(du->dk_altport);
	}
#endif

	lp = &du->dk_dd;
	secpertrk = lp->d_nsectors;
	secpercyl = lp->d_secpercyl;

	if (du->dk_skip == 0)
		du->dk_bc = bp->bio_bcount;

	wdtab[ctrlr].b_active = 1;	/* mark controller active */

	/* if starting a multisector transfer, or doing single transfers */
	if (du->dk_skip == 0 || (du->dk_flags & DKFL_SINGLE)) {
		u_int	command;
		u_int	count1;
		long	cylin, head, sector;

		if (du->dk_flags & DKFL_LBA) {
			sector = (blknum >> 0) & 0xff; 
			cylin = (blknum >> 8) & 0xffff;
			head = ((blknum >> 24) & 0xf) | WDSD_LBA; 
		} else {
			cylin = blknum / secpercyl;
			head = (blknum % secpercyl) / secpertrk;
			sector = blknum % secpertrk;
		}
		/* 
		 * XXX this looks like an attempt to skip bad sectors
		 * on write.
		 */
		if (wdtab[ctrlr].b_errcnt && (bp->bio_cmd == BIO_WRITE))
			du->dk_bc += DEV_BSIZE;

		count1 = howmany( du->dk_bc, DEV_BSIZE);

		du->dk_flags &= ~DKFL_MULTI;

		if (du->dk_flags & DKFL_SINGLE) {
			command = (bp->bio_cmd == BIO_READ)
				  ? WDCC_READ : WDCC_WRITE;
			count1 = 1;
			du->dk_currentiosize = 1;
		} else {
			if((du->dk_flags & DKFL_USEDMA) &&
			   wddma[du->dk_interface].wdd_dmaverify(du->dk_dmacookie,
				(void *)((int)bp->bio_data + 
				     du->dk_skip * DEV_BSIZE),
				du->dk_bc,
				bp->bio_cmd == BIO_READ)) {
				du->dk_flags |= DKFL_DMA;
				if(bp->bio_cmd == BIO_READ)
					command = WDCC_READ_DMA;
				else
					command = WDCC_WRITE_DMA;
				du->dk_currentiosize = count1;
			} else if( (count1 > 1) && (du->dk_multi > 1)) {
				du->dk_flags |= DKFL_MULTI;
				if(bp->bio_cmd == BIO_READ) {
					command = WDCC_READ_MULTI;
				} else {
					command = WDCC_WRITE_MULTI;
				}
				du->dk_currentiosize = du->dk_multi;
				if( du->dk_currentiosize > count1)
					du->dk_currentiosize = count1;
			} else {
				if(bp->bio_cmd == BIO_READ) {
					command = WDCC_READ;
				} else {
					command = WDCC_WRITE;
				}
				du->dk_currentiosize = 1;
			}
		}

		/*
		 * XXX this loop may never terminate.  The code to handle
		 * counting down of retries and eventually failing the i/o
		 * is in wdintr() and we can't get there from here.
		 */
		if (wdtest != 0) {
			if (--wdtest == 0) {
				wdtest = 100;
				printf("dummy wdunwedge\n");
				wdunwedge(du);
			}
		}

		if ((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA) {
			wddma[du->dk_interface].wdd_dmaprep(du->dk_dmacookie,
					   (void *)((int)bp->bio_data + 
						    du->dk_skip * DEV_BSIZE),
					   du->dk_bc,
					   bp->bio_cmd == BIO_READ);
		}
		while (wdcommand(du, cylin, head, sector, count1, command)
		       != 0) {
			wderror(bp, du,
				"wdstart: timeout waiting to give command");
			wdunwedge(du);
		}
#ifdef WDDEBUG
		printf("cylin %ld head %ld sector %ld addr %x sts ",
		       cylin, head, sector,
		       (int)bp->bio_data + du->dk_skip * DEV_BSIZE);
		if (old_epson_note)
			printf("%x\n", epson_inb(du->dk_altport));
		else
			printf("%x\n", inb(du->dk_altport));
#endif
	}

	/*
	 * Schedule wdtimeout() to wake up after a few seconds.  Retrying
	 * unmarked bad blocks can take 3 seconds!  Then it is not good that
	 * we retry 5 times.
	 *
	 * On the first try, we give it 10 seconds, for drives that may need
	 * to spin up.
	 *
	 * XXX wdtimeout() doesn't increment the error count so we may loop
	 * forever.  More seriously, the loop isn't forever but causes a
	 * crash.
	 *
	 * TODO fix b_resid bug elsewhere (fd.c....).  Fix short but positive
	 * counts being discarded after there is an error (in physio I
	 * think).  Discarding them would be OK if the (special) file offset
	 * was not advanced.
	 */
	if (wdtab[ctrlr].b_errcnt == 0)
		du->dk_timeout = 1 + 10;
	else
		du->dk_timeout = 1 + 3;

	/* if this is a DMA op, start DMA and go away until it's done. */
	if ((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA) {
		wddma[du->dk_interface].wdd_dmastart(du->dk_dmacookie);
		return;
	}

	/* If this is a read operation, just go away until it's done. */
	if (bp->bio_cmd == BIO_READ)
		return;

	/* Ready to send data? */
	if (wdwait(du, WDCS_READY | WDCS_SEEKCMPLT | WDCS_DRQ, TIMEOUT) < 0) {
		wderror(bp, du, "wdstart: timeout waiting for DRQ");
		/*
		 * XXX what do we do now?  If we've just issued the command,
		 * then we can treat this failure the same as a command
		 * failure.  But if we are continuing a multi-sector write,
		 * the command was issued ages ago, so we can't simply
		 * restart it.
		 *
		 * XXX we waste a lot of time unnecessarily translating block
		 * numbers to cylin/head/sector for continued i/o's.
		 */
	}

	count = 1;
	if( du->dk_flags & DKFL_MULTI) {
		count = howmany(du->dk_bc, DEV_BSIZE);
		if( count > du->dk_multi)
			count = du->dk_multi;
		if( du->dk_currentiosize > count)
			du->dk_currentiosize = count;
	}
	if (!old_epson_note) {
		if (du->dk_flags & DKFL_32BIT)
			outsl(du->dk_port + wd_data,
			      (void *)((int)bp->bio_data
						+ du->dk_skip * DEV_BSIZE),
			      (count * DEV_BSIZE) / sizeof(long));
		else
			outsw(du->dk_port + wd_data,
			      (void *)((int)bp->bio_data
						+ du->dk_skip * DEV_BSIZE),
			      (count * DEV_BSIZE) / sizeof(short));
		}
	else
		epson_outsw(du->dk_port + wd_data,
		      (void *)((int)bp->bio_data + du->dk_skip * DEV_BSIZE),
		      (count * DEV_BSIZE) / sizeof(short));
		
	du->dk_bc -= DEV_BSIZE * count;
}

/* Interrupt routine for the controller.  Acknowledge the interrupt, check for
 * errors on the current operation, mark it done if necessary, and start
 * the next request.  Also check for a partially done transfer, and
 * continue with the next chunk if so.
 */

void
wdintr(void *unitnum)
{
	register struct	softc *du;
	register struct bio *bp;
	int dmastat = 0;			/* Shut up GCC */
	int unit = (int)unitnum;

	int ctrlr_atapi;

	if (eide_quirks & Q_CMD640B) {
		unit = PRIMARY;
		ctrlr_atapi = atapictrlr;
	} else {
		ctrlr_atapi = unit;
	}

	if (wdtab[unit].b_active == 2)
		return;		/* intr in wdflushirq() */
	if (!wdtab[unit].b_active) {
#ifdef WDDEBUG
		/*
		 * These happen mostly because the power-mgt part of the
		 * bios shuts us down, and we just manage to see the
		 * interrupt from the "SLEEP" command.
 		 */
		printf("wdc%d: extra interrupt\n", unit);
#endif
		return;
	}
	if (wdtab[unit].b_active == 3) {
		/* process an ATAPI interrupt */
		if (atapi_intr && atapi_intr (ctrlr_atapi))
			/* ATAPI op continues */
			return;
		/* controller is free, start new op */
		wdtab[unit].b_active = 0;
		wdstart (unit);
		return;
	}
	bp = bioq_first(&wdtab[unit].controller_queue);
	du = bp->bio_dev->si_drv1;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif
	/* finish off DMA */
	if ((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA) {
		/* XXX SMP boxes sometimes generate an early intr.  Why? */
		if ((wddma[du->dk_interface].wdd_dmastatus(du->dk_dmacookie) & 
		    WDDS_INTERRUPT) == 0)
			return;
		dmastat = wddma[du->dk_interface].wdd_dmadone(du->dk_dmacookie);
	}

	du->dk_timeout = 0;

	/* check drive status/failure */
	if (wdwait(du, 0, TIMEOUT) < 0) {
		wderror(bp, du, "wdintr: timeout waiting for status");
		du->dk_status |= WDCS_ERR;	/* XXX */
	}

	/* is it not a transfer, but a control operation? */
	if (du->dk_state < OPEN) {
		wdtab[unit].b_active = 0;
		switch (wdcontrol(bp)) {
		case 0:
			return;
		case 1:
			wdstart(unit);
			return;
		case 2:
			goto done;
		}
	}

	/* have we an error? */
	if ((du->dk_status & (WDCS_ERR | WDCS_ECCCOR))
	    || (((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA)
		&& dmastat != WDDS_INTERRUPT)) {

		unsigned int errstat;
oops:
		/*
		 * XXX bogus inb() here
		 */
		errstat = inb(du->dk_port + wd_error);

		if(((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA) &&
		   (errstat & WDERR_ABORT)) {
			wderror(bp, du, "reverting to PIO mode");
			du->dk_flags &= ~DKFL_USEDMA;
		} else if((du->dk_flags & DKFL_MULTI) &&
                    (errstat & WDERR_ABORT)) {
			wderror(bp, du, "reverting to non-multi sector mode");
			du->dk_multi = 1;
		}

		if (!(du->dk_status & (WDCS_ERR | WDCS_ECCCOR)) &&
		    (((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA) && 
		     (dmastat != WDDS_INTERRUPT)))
			printf("wd%d: DMA failure, DMA status %b\n", 
			       du->dk_lunit, dmastat, WDDS_BITS);
#ifdef WDDEBUG
		wderror(bp, du, "wdintr");
#endif
		if ((du->dk_flags & DKFL_SINGLE) == 0) {
			du->dk_flags |= DKFL_ERROR;
			goto outt;
		}

		if (du->dk_status & WDCS_ERR) {
			if (++wdtab[unit].b_errcnt < RETRIES) {
				wdtab[unit].b_active = 0;
			} else {
				wderror(bp, du, "hard error");
				bp->bio_error = EIO;
				bp->bio_flags |= BIO_ERROR;	/* flag the error */
			}
		} else if (du->dk_status & WDCS_ECCCOR)
			wderror(bp, du, "soft ecc");
	}

	/*
	 * If this was a successful read operation, fetch the data.
	 */
	if (bp->bio_cmd == BIO_READ && !(bp->bio_flags & BIO_ERROR)
            && !((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA)
	    && wdtab[unit].b_active) {
		u_int	chk, dummy, multisize;
		multisize = chk = du->dk_currentiosize * DEV_BSIZE;
		if( du->dk_bc < chk) {
			chk = du->dk_bc;
			if( ((chk + DEV_BSIZE - 1) / DEV_BSIZE) < du->dk_currentiosize) {
				du->dk_currentiosize = (chk + DEV_BSIZE - 1) / DEV_BSIZE;
				multisize = du->dk_currentiosize * DEV_BSIZE;
			}
		}

		/* ready to receive data? */
		if ((du->dk_status & (WDCS_READY | WDCS_SEEKCMPLT | WDCS_DRQ))
		    != (WDCS_READY | WDCS_SEEKCMPLT | WDCS_DRQ))
			wderror(bp, du, "wdintr: read intr arrived early");
		if (wdwait(du, WDCS_READY | WDCS_SEEKCMPLT | WDCS_DRQ, TIMEOUT) != 0) {
			wderror(bp, du, "wdintr: read error detected late");
			goto oops;
		}

		/* suck in data */
		if( du->dk_flags & DKFL_32BIT)
			insl(du->dk_port + wd_data,
			     (void *)((int)bp->bio_data + du->dk_skip * DEV_BSIZE),
					chk / sizeof(long));
		else
			insw(du->dk_port + wd_data,
			     (void *)((int)bp->bio_data + du->dk_skip * DEV_BSIZE),
					chk / sizeof(short));
		du->dk_bc -= chk;

		/* XXX for obsolete fractional sector reads. */
		while (chk < multisize) {
			insw(du->dk_port + wd_data, &dummy, 1);
			chk += sizeof(short);
		}

	}

	/* final cleanup on DMA */
	if (((bp->bio_flags & BIO_ERROR) == 0)
            && ((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA)
	    && wdtab[unit].b_active) {
		int iosize;

		iosize = du->dk_currentiosize * DEV_BSIZE;

		du->dk_bc -= iosize;

	}

outt:
	if (wdtab[unit].b_active) {
		if ((bp->bio_flags & BIO_ERROR) == 0) {
			du->dk_skip += du->dk_currentiosize;/* add to successful sectors */
			if (wdtab[unit].b_errcnt)
				wderror(bp, du, "soft error");
			wdtab[unit].b_errcnt = 0;

			/* see if more to transfer */
			if (du->dk_bc > 0 && (du->dk_flags & DKFL_ERROR) == 0) {
				if( (du->dk_flags & DKFL_SINGLE) ||
					(bp->bio_cmd == BIO_WRITE)) {
					wdtab[unit].b_active = 0;
					wdstart(unit);
				} else {
					du->dk_timeout = 1 + 3;
				}
				return;	/* next chunk is started */
			} else if ((du->dk_flags & (DKFL_SINGLE | DKFL_ERROR))
				   == DKFL_ERROR) {
				du->dk_skip = 0;
				du->dk_flags &= ~DKFL_ERROR;
				du->dk_flags |= DKFL_SINGLE;
				wdtab[unit].b_active = 0;
				wdstart(unit);
				return;	/* redo xfer sector by sector */
			}
		}

done: ;
		/* done with this transfer, with or without error */
		du->dk_flags &= ~(DKFL_SINGLE|DKFL_DMA);
		bioq_remove( &wdtab[unit].controller_queue, bp);
		wdtab[unit].b_errcnt = 0;
		bp->bio_resid = bp->bio_bcount - du->dk_skip * DEV_BSIZE;
		wdutab[du->dk_lunit].b_active = 0;
		du->dk_skip = 0;
		biodone(bp);
	}

	/* controller idle */
	wdtab[unit].b_active = 0;

	/* anything more on drive queue? */
	wdustart(du);
	/* anything more for controller to do? */
	wdstart(unit);
}

/*
 * Initialize a drive.
 */
int
wdopen(struct disk *dp)
{
	register struct softc *du;

	du = dp->d_drv1;
	if (du == NULL)
		return (ENXIO);

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

	/* Finish flushing IRQs left over from wdattach(). */
	if (wdtab[du->dk_ctrlr_cmd640].b_active == 2)
		wdtab[du->dk_ctrlr_cmd640].b_active = 0;

	du->dk_flags &= ~DKFL_BADSCAN;

	/* spin waiting for anybody else reading the disk label */
	while (du->dk_flags & DKFL_LABELLING)
		tsleep((caddr_t)&du->dk_flags, PZERO - 1, "wdopen", 1);

	wdsleep(du->dk_ctrlr, "wdopn1");
	du->dk_flags |= DKFL_LABELLING;
	du->dk_state = WANTOPEN;

	du->disk->d_sectorsize = du->dk_dd.d_secsize;
	du->disk->d_mediasize = du->dk_dd.d_secperunit * du->dk_dd.d_secsize;
	du->disk->d_fwsectors = du->dk_dd.d_nsectors;
	du->disk->d_fwheads = du->dk_dd.d_ntracks;

	du->dk_flags &= ~DKFL_LABELLING;
	wdsleep(du->dk_ctrlr, "wdopn2");

	return 0;
}

/*
 * Implement operations other than read/write.
 * Called from wdstart or wdintr during opens.
 * Uses finite-state-machine to track progress of operation in progress.
 * Returns 0 if operation still in progress, 1 if completed, 2 if error.
 */
static int
wdcontrol(register struct bio *bp)
{
	register struct softc *du;
	int	ctrlr;

	du = bp->bio_dev->si_drv1;
	ctrlr = du->dk_ctrlr_cmd640;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

	switch (du->dk_state) {
	case WANTOPEN:
tryagainrecal:
		wdtab[ctrlr].b_active = 1;
		if (wdcommand(du, 0, 0, 0, 0, WDCC_RESTORE | WD_STEP) != 0) {
			wderror(bp, du, "wdcontrol: wdcommand failed");
			goto maybe_retry;
		}
		du->dk_state = RECAL;
		return (0);
	case RECAL:
		if (du->dk_status & WDCS_ERR || wdsetctlr(du) != 0) {
			wderror(bp, du, "wdcontrol: recal failed");
maybe_retry:
			if (du->dk_status & WDCS_ERR)
				wdunwedge(du);
			du->dk_state = WANTOPEN;
			if (++wdtab[ctrlr].b_errcnt < RETRIES)
				goto tryagainrecal;
			bp->bio_error = ENXIO;	/* XXX needs translation */
			bp->bio_flags |= BIO_ERROR;
			return (2);
		}
		wdtab[ctrlr].b_errcnt = 0;
		du->dk_state = OPEN;
		/*
		 * The rest of the initialization can be done by normal
		 * means.
		 */
		return (1);
	}
	panic("wdcontrol");
	return (2);
}

/*
 * Wait uninterruptibly until controller is not busy, then send it a command.
 * The wait usually terminates immediately because we waited for the previous
 * command to terminate.
 */
static int
wdcommand(struct softc *du, u_int cylinder, u_int head, u_int sector,
	  u_int count, u_int command)
{
	u_int	wdc;
#ifdef PC98
	unsigned char	u_addr;
#endif

	wdc = du->dk_port;
	if (du->cfg_flags & WDOPT_SLEEPHACK) {
		/* OK, so the APM bios has put the disk into SLEEP mode,
		 * how can we tell ?  Uhm, we can't.  There is no 
		 * standardized way of finding out, and the only way to
		 * wake it up is to reset it.  Bummer.
		 *
		 * All the many and varied versions of the IDE/ATA standard
		 * explicitly tells us not to look at these registers if
		 * the disk is in SLEEP mode.  Well, too bad really, we
		 * have to find out if it's in sleep mode before we can 
		 * avoid reading the registers.
		 *
		 * I have reason to belive that most disks will return
		 * either 0xff or 0x00 in all but the status register 
		 * when in SLEEP mode, but I have yet to see one return 
		 * 0x00, so we don't check for that yet.
		 *
		 * The check for WDCS_BUSY is for the case where the
		 * bios spins up the disk for us, but doesn't initialize
		 * it correctly					/phk
		 */
		if (old_epson_note) {
			if(epson_inb(wdc + wd_precomp) + epson_inb(wdc + wd_cyl_lo) +
			   epson_inb(wdc + wd_cyl_hi) + epson_inb(wdc + wd_sdh) +
			   epson_inb(wdc + wd_sector) +
			   epson_inb(wdc + wd_seccnt) == 6 * 0xff) {
				if (bootverbose)
					printf("wd(%d,%d): disk aSLEEP\n",
						   du->dk_ctrlr, du->dk_unit);
				wdunwedge(du);
			} else if(epson_inb(wdc + wd_status) == WDCS_BUSY) {
				if (bootverbose)
					printf("wd(%d,%d): disk is BUSY\n",
						   du->dk_ctrlr, du->dk_unit);
				wdunwedge(du);
			}
		} else {
			if(inb(wdc + wd_precomp) + inb(wdc + wd_cyl_lo) +
			   inb(wdc + wd_cyl_hi) + inb(wdc + wd_sdh) +
			   inb(wdc + wd_sector) + inb(wdc + wd_seccnt) == 6 * 0xff) {
				if (bootverbose)
					printf("wd(%d,%d): disk aSLEEP\n",
						   du->dk_ctrlr, du->dk_unit);
				wdunwedge(du);
			} else if(inb(wdc + wd_status) == WDCS_BUSY) {
				if (bootverbose)
					printf("wd(%d,%d): disk is BUSY\n",
						   du->dk_ctrlr, du->dk_unit);
				wdunwedge(du);
			}
		}
	}

	if (wdwait(du, 0, TIMEOUT) < 0)
		return (1);
#ifdef PC98
/*	u_addr = (du->dk_unit & 0xfe);	*/
	u_addr = ((du->dk_unit)/2)<<4;
#endif /* PC98 */
	if( command == WDCC_FEATURES) {
		if (old_epson_note)
			epson_outb(wdc + wd_features, count);
		else {
			outb(wdc + wd_sdh, WDSD_IBM | (du->dk_unit << 4) | head);
			outb(wdc + wd_features, count);
			if ( count == WDFEA_SETXFER )
				outb(wdc + wd_seccnt, sector);
		}
	} else {
		if (old_epson_note) {
			epson_outb(wdc + wd_precomp, du->dk_dd.d_precompcyl/4);
			epson_outb(wdc + wd_cyl_lo, cylinder);
			epson_outb(wdc + wd_cyl_hi, cylinder >> 8);
			epson_outb(wdc + wd_sdh, WDSD_IBM | u_addr | head);
			epson_outb(wdc + wd_sector, sector + 1);
			epson_outb(wdc + wd_seccnt, count);
		}
		else {
			outb(wdc + wd_precomp, du->dk_dd.d_precompcyl / 4);
			outb(wdc + wd_cyl_lo, cylinder);
			outb(wdc + wd_cyl_hi, cylinder >> 8);
#ifdef PC98
			outb(wdc + wd_sdh, WDSD_IBM | u_addr | head);
#else
			outb(wdc + wd_sdh, WDSD_IBM | (du->dk_unit<<4) | head);
#endif
		if (head & WDSD_LBA)
			outb(wdc + wd_sector, sector);
		else
			outb(wdc + wd_sector, sector + 1);
		outb(wdc + wd_seccnt, count);
		}
	}
	if (wdwait(du, (command == WDCC_DIAGNOSE || command == WDCC_IDC)
		       ? 0 : WDCS_READY, TIMEOUT) < 0)
		return (1);
	if (old_epson_note)
		epson_outb(wdc + wd_command, command);
	else
		outb(wdc + wd_command, command);
	return (0);
}

static void
wdsetmulti(struct softc *du)
{
	/*
	 * The config option flags low 8 bits define the maximum multi-block
	 * transfer size.  If the user wants the maximum that the drive
	 * is capable of, just set the low bits of the config option to
	 * 0x00ff.
	 */
	if ((du->cfg_flags & WDOPT_MULTIMASK) != 0 && (du->dk_multi > 1)) {
		int configval = du->cfg_flags & WDOPT_MULTIMASK;
		du->dk_multi = min(du->dk_multi, configval);
		if (wdcommand(du, 0, 0, 0, du->dk_multi, WDCC_SET_MULTI)) {
			du->dk_multi = 1;
		} else {
		    	if (wdwait(du, WDCS_READY, TIMEOUT) < 0) {
				du->dk_multi = 1;
			}
		}
	} else {
		du->dk_multi = 1;
	}
}

/*
 * issue IDC to drive to tell it just what geometry it is to be.
 */
static int
wdsetctlr(struct softc *du)
{
	int error = 0;
#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif
#ifdef WDDEBUG
	printf("wd(%d,%d): wdsetctlr: C %lu H %lu S %lu\n",
	       du->dk_ctrlr, du->dk_unit,
	       du->dk_dd.d_ncylinders, du->dk_dd.d_ntracks,
	       du->dk_dd.d_nsectors);
#endif
	if (!(du->dk_flags & DKFL_LBA)) {
		if (du->dk_dd.d_ntracks == 0 || du->dk_dd.d_ntracks > 16) {
			struct wdparams *wp;
	
			printf("wd%d: can't handle %lu heads from partition table ",
		       	du->dk_lunit, du->dk_dd.d_ntracks);
			/* obtain parameters */
			wp = &du->dk_params;
			if (wp->wdp_heads > 0 && wp->wdp_heads <= 16) {
				printf("(controller value %u restored)\n",
					wp->wdp_heads);
				du->dk_dd.d_ntracks = wp->wdp_heads;
			}
			else {
				printf("(truncating to 16)\n");
				du->dk_dd.d_ntracks = 16;
			}
		}
	
		if (du->dk_dd.d_nsectors == 0 || du->dk_dd.d_nsectors > 255) {
			printf("wd%d: cannot handle %lu sectors (max 255)\n",
		       	du->dk_lunit, du->dk_dd.d_nsectors);
			error = 1;
		}
		if (error) {
			wdtab[du->dk_ctrlr_cmd640].b_errcnt += RETRIES;
			return (1);
		}
		if (wdcommand(du, du->dk_dd.d_ncylinders, 						      du->dk_dd.d_ntracks - 1, 0,
		      	      du->dk_dd.d_nsectors, WDCC_IDC) != 0
	    		      || wdwait(du, WDCS_READY, TIMEOUT) < 0) {
			wderror((struct bio *)NULL, du, "wdsetctlr failed");
			return (1);
		}
	}

	wdsetmulti(du);

#ifdef NOTYET
/* set read caching and write caching */
	wdcommand(du, 0, 0, 0, WDFEA_RCACHE, WDCC_FEATURES);
	wdwait(du, WDCS_READY, TIMEOUT);

	wdcommand(du, 0, 0, 0, WDFEA_WCACHE, WDCC_FEATURES);
	wdwait(du, WDCS_READY, TIMEOUT);
#endif

	return (0);
}

#if 0
/*
 * Wait until driver is inactive, then set up controller.
 */
static int
wdwsetctlr(struct softc *du)
{
	int	stat;
	int	x;

	wdsleep(du->dk_ctrlr, "wdwset");
	x = splbio();
	stat = wdsetctlr(du);
	wdflushirq(du, x);
	splx(x);
	return (stat);
}
#endif

/*
 * gross little callback function for wdddma interface. returns 1 for
 * success, 0 for failure.
 */
static int
wdsetmode(int mode, void *wdinfo)
{
    int i;
    struct softc *du;

    du = wdinfo;
    if (bootverbose)
	printf("wd%d: wdsetmode() setting transfer mode to %02x\n", 
	       du->dk_lunit, mode);
    i = wdcommand(du, 0, 0, mode, WDFEA_SETXFER, 
		  WDCC_FEATURES) == 0 &&
	wdwait(du, WDCS_READY, TIMEOUT) == 0;
    return i;
}

/*
 * issue READP to drive to ask it what it is.
 */
static int
wdgetctlr(struct softc *du)
{
	int	i;
	char    tb[DEV_BSIZE], tb2[DEV_BSIZE];
	struct wdparams *wp = NULL;
	u_long flags = du->cfg_flags;
#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

again:
	if (wdcommand(du, 0, 0, 0, 0, WDCC_READP) != 0
	    || wdwait(du, WDCS_READY | WDCS_SEEKCMPLT | WDCS_DRQ, TIMEOUT) != 0) {

#ifdef	PC98
		if ( du->dk_unit > 1 )
			return(1);
#endif
		/*
		 * if we failed on the second try, assume non-32bit
		 */
		if( du->dk_flags & DKFL_32BIT)
			goto failed;

		/* XXX need to check error status after final transfer. */
		/*
		 * Old drives don't support WDCC_READP.  Try a seek to 0.
		 * Some IDE controllers return trash if there is no drive
		 * attached, so first test that the drive can be selected.
		 * This also avoids long waits for nonexistent drives.
		 */
		if (wdwait(du, 0, TIMEOUT) < 0)
			return (1);
		if (old_epson_note) {
			epson_outb(du->dk_port + wd_sdh,
						WDSD_IBM | (du->dk_unit << 4));
			DELAY(5000);	/* usually unnecessary; drive select is fast */
			if ((epson_inb(du->dk_port + wd_status)
						& (WDCS_BUSY | WDCS_READY))
			    != WDCS_READY
			    || wdcommand(du, 0, 0, 0, 0, WDCC_RESTORE | WD_STEP) != 0
			    || wdwait(du, WDCS_READY | WDCS_SEEKCMPLT, TIMEOUT) != 0)
				return (1);
		}
		else {
			outb(du->dk_port + wd_sdh, WDSD_IBM | (du->dk_unit << 4));
			DELAY(5000);	/* usually unnecessary; drive select is fast */
		/*
		 * Do this twice: may get a false WDCS_READY the first time.
		 */
		inb(du->dk_port + wd_status);
			if ((inb(du->dk_port + wd_status) & (WDCS_BUSY | WDCS_READY))
			    != WDCS_READY
			    || wdcommand(du, 0, 0, 0, 0, WDCC_RESTORE | WD_STEP) != 0
			    || wdwait(du, WDCS_READY | WDCS_SEEKCMPLT, TIMEOUT) != 0)
				return (1);
		}
		if (du->dk_unit == bootinfo.bi_n_bios_used) {
			du->dk_dd.d_secsize = DEV_BSIZE;
			du->dk_dd.d_nsectors =
			    bootinfo.bi_bios_geom[du->dk_unit] & 0xff;
			du->dk_dd.d_ntracks =
			    ((bootinfo.bi_bios_geom[du->dk_unit] >> 8) & 0xff)
			    + 1;
			/* XXX Why 2 ? */
			du->dk_dd.d_ncylinders =
			    (bootinfo.bi_bios_geom[du->dk_unit] >> 16) + 2;
			du->dk_dd.d_secpercyl =
			    du->dk_dd.d_ntracks * du->dk_dd.d_nsectors;
			du->dk_dd.d_secperunit =
			    du->dk_dd.d_secpercyl * du->dk_dd.d_ncylinders;
#if 0
			du->dk_dd.d_partitions[WDRAW].p_size =
				du->dk_dd.d_secperunit;
			du->dk_dd.d_type = DTYPE_ST506;
			du->dk_dd.d_subtype |= DSTYPE_GEOMETRY;
			strncpy(du->dk_dd.d_typename, "Bios geometry",
				sizeof du->dk_dd.d_typename);
			strncpy(du->dk_params.wdp_model, "ST506",
				sizeof du->dk_params.wdp_model);
#endif
			bootinfo.bi_n_bios_used ++;
			return 0;
		}
		/*
		 * Fake minimal drive geometry for reading the MBR.
		 * readdisklabel() may enlarge it to read the label and the
		 * bad sector table.
		 */
		du->dk_dd.d_secsize = DEV_BSIZE;
		du->dk_dd.d_nsectors = 17;
		du->dk_dd.d_ntracks = 1;
		du->dk_dd.d_ncylinders = 1;
		du->dk_dd.d_secpercyl = 17;
		du->dk_dd.d_secperunit = 17;

#if 0
		/*
		 * Fake maximal drive size for writing the label.
		 */
		du->dk_dd.d_partitions[RAW_PART].p_size = 64 * 16 * 1024;

		/*
		 * Fake some more of the label for printing by disklabel(1)
		 * in case there is no real label.
		 */
		du->dk_dd.d_type = DTYPE_ST506;
		du->dk_dd.d_subtype |= DSTYPE_GEOMETRY;
		strncpy(du->dk_dd.d_typename, "Fake geometry",
			sizeof du->dk_dd.d_typename);
#endif

		/* Fake the model name for printing by wdattach(). */
		strncpy(du->dk_params.wdp_model, "unknown",
			sizeof du->dk_params.wdp_model);

		return (0);
	}

	/* obtain parameters */
	wp = &du->dk_params;
	if (!old_epson_note) {
		if (du->dk_flags & DKFL_32BIT)
			insl(du->dk_port + wd_data, tb,
						sizeof(tb) / sizeof(long));
		else
			insw(du->dk_port + wd_data, tb,
						sizeof(tb) / sizeof(short));
	}
	else
		epson_insw(du->dk_port + wd_data, tb,
						sizeof(tb) / sizeof(short));

	/* try 32-bit data path (VLB IDE controller) */
	if (flags & WDOPT_32BIT) {
		if (! (du->dk_flags & DKFL_32BIT)) {
			bcopy(tb, tb2, sizeof(struct wdparams));
			du->dk_flags |= DKFL_32BIT;
			goto again;
		}

		/* check that we really have 32-bit controller */
		if (bcmp (tb, tb2, sizeof(struct wdparams)) != 0) {
failed:
			/* test failed, use 16-bit i/o mode */
			bcopy(tb2, tb, sizeof(struct wdparams));
			du->dk_flags &= ~DKFL_32BIT;
		}
	}

	bcopy(tb, wp, sizeof(struct wdparams));

	/* shuffle string byte order */
	for (i = 0; (unsigned)i < sizeof(wp->wdp_model); i += 2) {
		u_short *p;

		p = (u_short *) (wp->wdp_model + i);
		*p = ntohs(*p);
	}
	/*
	 * Clean up the wdp_model by converting nulls to spaces, and
	 * then removing the trailing spaces.
	 */
	for (i = 0; (unsigned)i < sizeof(wp->wdp_model); i++) {
		if (wp->wdp_model[i] == '\0') {
			wp->wdp_model[i] = ' ';
		}
	}
	for (i = sizeof(wp->wdp_model) - 1;
	    (i >= 0 && wp->wdp_model[i] == ' '); i--) {
		wp->wdp_model[i] = '\0';
	}

	/*
	 * find out the drives maximum multi-block transfer capability
	 */
	du->dk_multi = wp->wdp_nsecperint & 0xff;
	wdsetmulti(du);

	/*
	 * check drive's DMA capability
	 */
	if (wddma[du->dk_interface].wdd_candma) {
		du->dk_dmacookie = wddma[du->dk_interface].wdd_candma(
		    du->dk_port, du->dk_ctrlr, du->dk_unit);
	/* does user want this? */
		if ((du->cfg_flags & WDOPT_DMA) &&
	    /* have we got a DMA controller? */
		     du->dk_dmacookie &&
		    /* can said drive do DMA? */
		     wddma[du->dk_interface].wdd_dmainit(du->dk_dmacookie, wp, wdsetmode, du)) {
		    du->dk_flags |= DKFL_USEDMA;
		}
	} else {
		du->dk_dmacookie = NULL;
	}

#ifdef WDDEBUG
	printf(
"\nwd(%d,%d): wdgetctlr: gc %x cyl %d trk %d sec %d type %d sz %d model %s\n",
	       du->dk_ctrlr, du->dk_unit, wp->wdp_config, wp->wdp_cylinders,
	       wp->wdp_heads, wp->wdp_sectors, wp->wdp_buffertype,
	       wp->wdp_buffersize, wp->wdp_model);
#endif
#ifdef PC98
	/* for larger than 40MB */
	{
	  long cyl = wp->wdp_cylinders * wp->wdp_heads * wp->wdp_sectors;

	  if ( du->dk_unit > 1 ) {
	 	 wp->wdp_sectors = 17;
		 wp->wdp_heads = 8;
	  } else {
		 wp->wdp_sectors = bootinfo.bi_bios_geom[du->dk_unit] & 0xff;
		 wp->wdp_heads = (bootinfo.bi_bios_geom[du->dk_unit] >> 8) & 0xff;
	  }

	  wp->wdp_cylinders = cyl / (wp->wdp_heads * wp->wdp_sectors);
	}
#endif

	/* update disklabel given drive information */
	du->dk_dd.d_secsize = DEV_BSIZE;
	if ((du->cfg_flags & WDOPT_LBA) && wp->wdp_lbasize) {
		du->dk_dd.d_nsectors = 63;
		if (wp->wdp_lbasize < 16*63*1024) {		/* <=528.4 MB */
			du->dk_dd.d_ntracks = 16;
		}
		else if (wp->wdp_lbasize < 32*63*1024) {	/* <=1.057 GB */
			du->dk_dd.d_ntracks = 32;
		}
		else if (wp->wdp_lbasize < 64*63*1024) {	/* <=2.114 GB */
			du->dk_dd.d_ntracks = 64;
		}
		else if (wp->wdp_lbasize < 128*63*1024) {	/* <=4.228 GB */
			du->dk_dd.d_ntracks = 128;
		}
		else if (wp->wdp_lbasize < 255*63*1024) {	/* <=8.422 GB */
			du->dk_dd.d_ntracks = 255;
		}
		else {						/* >8.422 GB */
			du->dk_dd.d_ntracks = 255;		/* XXX */
		}
		du->dk_dd.d_secpercyl= du->dk_dd.d_ntracks*du->dk_dd.d_nsectors;
		du->dk_dd.d_ncylinders = wp->wdp_lbasize/du->dk_dd.d_secpercyl;
		du->dk_dd.d_secperunit = wp->wdp_lbasize;
		du->dk_flags |= DKFL_LBA;
	}
	else {
		du->dk_dd.d_ncylinders = wp->wdp_cylinders;	/* +- 1 */
		du->dk_dd.d_ntracks = wp->wdp_heads;
		du->dk_dd.d_nsectors = wp->wdp_sectors;
		du->dk_dd.d_secpercyl = 
			du->dk_dd.d_ntracks * du->dk_dd.d_nsectors;
		du->dk_dd.d_secperunit = 
			du->dk_dd.d_secpercyl * du->dk_dd.d_ncylinders;
		if (wp->wdp_cylinders == 16383 &&
		    du->dk_dd.d_secperunit < wp->wdp_lbasize) {
			du->dk_dd.d_secperunit = wp->wdp_lbasize;
			du->dk_dd.d_ncylinders = 
				du->dk_dd.d_secperunit / du->dk_dd.d_secpercyl;
		}
	}
	if (WDOPT_FORCEHD(du->cfg_flags)) {
		du->dk_dd.d_ntracks = WDOPT_FORCEHD(du->cfg_flags);
		du->dk_dd.d_secpercyl = 
		    du->dk_dd.d_ntracks * du->dk_dd.d_nsectors;
		du->dk_dd.d_ncylinders =
		    du->dk_dd.d_secperunit / du->dk_dd.d_secpercyl;
	}
	if (du->dk_dd.d_ncylinders > 0x10000 && !(du->cfg_flags & WDOPT_LBA)) {
		du->dk_dd.d_ncylinders = 0x10000;
		du->dk_dd.d_secperunit = du->dk_dd.d_secpercyl *
		    du->dk_dd.d_ncylinders;
		printf(
		    "wd%d: cannot handle %d total sectors; truncating to %lu\n",
		    du->dk_lunit, wp->wdp_lbasize, du->dk_dd.d_secperunit);
	}
#if 0
	du->dk_dd.d_partitions[RAW_PART].p_size = du->dk_dd.d_secperunit;
	/* dubious ... */
	bcopy("ESDI/IDE", du->dk_dd.d_typename, 9);
	bcopy(wp->wdp_model + 20, du->dk_dd.d_packname, 14 - 1);
	/* better ... */
	du->dk_dd.d_type = DTYPE_ESDI;
	du->dk_dd.d_subtype |= DSTYPE_GEOMETRY;
#endif

	return (0);
}

static void
wderror(struct bio *bp, struct softc *du, char *mesg)
{
	if (bp == NULL)
		printf("wd%d: %s", du->dk_lunit, mesg);
	else
		disk_err(bp, mesg, du->dk_skip, 0);
	printf(" (status %b error %b)\n",
	       du->dk_status, WDCS_BITS, du->dk_error, WDERR_BITS);
}

/*
 * Discard any interrupts that were latched by the interrupt system while
 * we were doing polled i/o.
 */
static void
wdflushirq(struct softc *du, int old_ipl)
{
	wdtab[du->dk_ctrlr_cmd640].b_active = 2;
	splx(old_ipl);
	(void)splbio();
	wdtab[du->dk_ctrlr_cmd640].b_active = 0;
}

/*
 * Reset the controller.
 */
static int
wdreset(struct softc *du)
{
	int     err = 0;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif
	if ((du->dk_flags & (DKFL_DMA|DKFL_SINGLE)) == DKFL_DMA)
		wddma[du->dk_interface].wdd_dmadone(du->dk_dmacookie);
	(void)wdwait(du, 0, TIMEOUT);
#ifdef PC98
	if (old_epson_note) {
		epson_outb(du->dk_altport, WDCTL_IDS | WDCTL_RST);
		DELAY(10 * 1000);
		epson_outb(du->dk_altport, WDCTL_IDS);
		if (wdwait(du, WDCS_READY | WDCS_SEEKCMPLT, TIMEOUT) != 0
		    || (du->dk_error = epson_errorf(du->dk_port + wd_error)) != 0x01)
			return (1);
		epson_outb(du->dk_altport, WDCTL_4BIT);
		err = 0;
	}
	else {
#endif
	outb(du->dk_altport, WDCTL_IDS | WDCTL_RST);
	DELAY(10 * 1000);
	outb(du->dk_altport, WDCTL_IDS);
	outb(du->dk_port + wd_sdh, WDSD_IBM | (du->dk_unit << 4));
	if (wdwait(du, 0, TIMEOUT) != 0)
		err = 1;                /* no IDE drive found */
	du->dk_error = inb(du->dk_port + wd_error);
	if (du->dk_error != 0x01)
		err = 1;                /* the drive is incompatible */
	outb(du->dk_altport, WDCTL_4BIT);
#ifdef PC98
	}
#endif
	return (err);
}

/*
 * Sleep until driver is inactive.
 * This is used only for avoiding rare race conditions, so it is unimportant
 * that the sleep may be far too short or too long.
 */
static void
wdsleep(int ctrlr, char *wmesg)
{
	int s = splbio();
	if (eide_quirks & Q_CMD640B)
		ctrlr = PRIMARY;
	while (wdtab[ctrlr].b_active)
		tsleep((caddr_t)&wdtab[ctrlr].b_active, PZERO - 1, wmesg, 1);
	splx(s);
}

static void
wdtimeout(void *cdu)
{
	struct softc *du;
	int	x;
	static	int	timeouts;

	du = (struct softc *)cdu;
	x = splbio();
#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif
	if (du->dk_timeout != 0 && --du->dk_timeout == 0) {
		if(timeouts++ <= 5) {
			char *msg;

			msg = (timeouts > 5) ?
"Last time I say: interrupt timeout.  Probably a portable PC." :
"interrupt timeout";
			wderror((struct bio *)NULL, du, msg);
			if (du->dk_dmacookie)
				printf("wd%d: wdtimeout() DMA status %b\n", 
				       du->dk_lunit,
				       wddma[du->dk_interface].wdd_dmastatus(du->dk_dmacookie), 
				       WDDS_BITS);
		}
		wdunwedge(du);
		wdflushirq(du, x);
		du->dk_skip = 0;
		du->dk_flags |= DKFL_SINGLE;
		wdstart(du->dk_ctrlr);
	}
	timeout(wdtimeout, cdu, hz);
	splx(x);
}

/*
 * Reset the controller after it has become wedged.  This is different from
 * wdreset() so that wdreset() can be used in the probe and so that this
 * can restore the geometry .
 */
static int
wdunwedge(struct softc *du)
{
	struct softc *du1;
	int	lunit;

#ifdef PC98
	outb(0x432,(du->dk_unit)%2);
#endif

	/* Schedule other drives for recalibration. */
	for (lunit = 0; lunit < NWD; lunit++)
		if ((du1 = wddrives[lunit]) != NULL && du1 != du
		    && du1->dk_ctrlr == du->dk_ctrlr
		    && du1->dk_state > WANTOPEN)
			du1->dk_state = WANTOPEN;

	DELAY(RECOVERYTIME);
	if (wdreset(du) == 0) {
		/*
		 * XXX - recalibrate current drive now because some callers
		 * aren't prepared to have its state change.
		 */
		if (wdcommand(du, 0, 0, 0, 0, WDCC_RESTORE | WD_STEP) == 0
		    && wdwait(du, WDCS_READY | WDCS_SEEKCMPLT, TIMEOUT) == 0
		    && wdsetctlr(du) == 0)
			return (0);
	}
	wderror((struct bio *)NULL, du, "wdunwedge failed");
	return (1);
}

/*
 * Wait uninterruptibly until controller is not busy and either certain
 * status bits are set or an error has occurred.
 * The wait is usually short unless it is for the controller to process
 * an entire critical command.
 * Return 1 for (possibly stale) controller errors, -1 for timeout errors,
 * or 0 for no errors.
 * Return controller status in du->dk_status and, if there was a controller
 * error, return the error code in du->dk_error.
 */
#ifdef WD_COUNT_RETRIES
static int min_retries[NWDC];
#endif

static int
wdwait(struct softc *du, u_char bits_wanted, int timeout)
{
	int	wdc;
	u_char	status;

#define	POLLING		1000

	wdc = du->dk_port;
	timeout += POLLING;

/*
 * This delay is really too long, but does not impact the performance
 * as much when using the multi-sector option.  Shorter delays have
 * caused I/O errors on some drives and system configs.  This should
 * probably be fixed if we develop a better short term delay mechanism.
 */
	DELAY(1);

	do {
#ifdef WD_COUNT_RETRIES
		if (min_retries[du->dk_ctrlr] > timeout
		    || min_retries[du->dk_ctrlr] == 0)
			min_retries[du->dk_ctrlr] = timeout;
#endif
#ifdef PC98
		if (old_epson_note)
			du->dk_status = status = epson_inb(wdc + wd_status);
		else
			du->dk_status = status = inb(wdc + wd_status);
#else
		du->dk_status = status = inb(wdc + wd_status);
#endif
		/*
		 * Atapi drives have a very interesting feature, when attached
		 * as a slave on the IDE bus, and there is no master.
		 * They release the bus after getting the command.
		 * We should reselect the drive here to get the status.
		 */
		if (status == 0xff) {
			outb(wdc + wd_sdh, WDSD_IBM | du->dk_unit << 4);
			du->dk_status = status = inb(wdc + wd_status);
		}
		if (!(status & WDCS_BUSY)) {
			if (status & WDCS_ERR) {
				if (old_epson_note)
					du->dk_error = epson_errorf(wdc + wd_error);
				else
					du->dk_error = inb(wdc + wd_error);
				/*
				 * We once returned here.  This is wrong
				 * because the error bit is apparently only
				 * valid after the controller has interrupted
				 * (e.g., the error bit is stale when we wait
				 * for DRQ for writes).  So we can't depend
				 * on the error bit at all when polling for
				 * command completion.
				 */
			}
			if ((status & bits_wanted) == bits_wanted) {
				return (status & WDCS_ERR);
			}
		}
		if (timeout < TIMEOUT)
			/*
			 * Switch to a polling rate of about 1 KHz so that
			 * the timeout is almost machine-independent.  The
			 * controller is taking a long time to respond, so
			 * an extra msec won't matter.
			 */
			DELAY(1000);
		else
			DELAY(1);
	} while (--timeout != 0);
	return (-1);
}

#endif /* NWDC > 0 */