No empty .Rs/.Re

[netbsd-mini2440.git] / sys / arch / sun3 / dev / xd.c

/*      $NetBSD: xd.c,v 1.66 2009/01/12 08:27:26 cegger Exp $   */

/*
 *
 * Copyright (c) 1995 Charles D. Cranor
 * 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 Charles D. Cranor.
 * 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.
 */

/*
 *
 * x d . c   x y l o g i c s   7 5 3 / 7 0 5 3   v m e / s m d   d r i v e r
 *
 * author: Chuck Cranor <chuck@ccrc.wustl.edu>
 * id: &Id: xd.c,v 1.9 1995/09/25 20:12:44 chuck Exp &
 * started: 27-Feb-95
 * references: [1] Xylogics Model 753 User's Manual
 *                 part number: 166-753-001, Revision B, May 21, 1988.
 *                 "Your Partner For Performance"
 *             [2] other NetBSD disk device drivers
 *
 * Special thanks go to Scott E. Campbell of Xylogics, Inc. for taking
 * the time to answer some of my questions about the 753/7053.
 *
 * note: the 753 and the 7053 are programmed the same way, but are
 * different sizes.   the 753 is a 6U VME card, while the 7053 is a 9U
 * VME card (found in many VME based suns).
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xd.c,v 1.66 2009/01/12 08:27:26 cegger Exp $");

#undef XDC_DEBUG                /* full debug */
#define XDC_DIAG                /* extra sanity checks */
#if defined(DIAGNOSTIC) && !defined(XDC_DIAG)
#define XDC_DIAG                /* link in with master DIAG option */
#endif

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/syslog.h>
#include <sys/dkbad.h>
#include <sys/conf.h>
#include <sys/kauth.h>

#include <uvm/uvm_extern.h>

#include <machine/autoconf.h>
#include <machine/dvma.h>

#include <dev/sun/disklabel.h>

#include <sun3/dev/xdreg.h>
#include <sun3/dev/xdvar.h>
#include <sun3/dev/xio.h>

#include "ioconf.h"
#include "locators.h"

/*
 * Print a complaint when no xd children were specified
 * in the config file.  Better than a link error...
 *
 * XXX: Some folks say this driver should be split in two,
 * but that seems pointless with ONLY one type of child.
 */
#include "xd.h"
#if NXD == 0
#error "xdc but no xd?"
#endif

/*
 * macros
 */

/*
 * XDC_TWAIT: add iorq "N" to tail of SC's wait queue
 */
#define XDC_TWAIT(SC, N)                                                \
do {                                                                    \
        (SC)->waitq[(SC)->waitend] = (N);                               \
        (SC)->waitend = ((SC)->waitend + 1) % XDC_MAXIOPB;              \
        (SC)->nwait++;                                                  \
} while (/* CONSTCOND */ 0)

/*
 * XDC_HWAIT: add iorq "N" to head of SC's wait queue
 */
#define XDC_HWAIT(SC, N)                                                \
do {                                                                    \
        (SC)->waithead = ((SC)->waithead == 0) ?                        \
            (XDC_MAXIOPB - 1) : ((SC)->waithead - 1);                   \
        (SC)->waitq[(SC)->waithead] = (N);                              \
        (SC)->nwait++;                                                  \
} while (/* CONSTCOND */ 0)

/*
 * XDC_GET_WAITER: gets the first request waiting on the waitq
 * and removes it (so it can be submitted)
 */
#define XDC_GET_WAITER(XDCSC, RQ)                                       \
do {                                                                    \
        (RQ) = (XDCSC)->waitq[(XDCSC)->waithead];                       \
        (XDCSC)->waithead = ((XDCSC)->waithead + 1) % XDC_MAXIOPB;      \
        xdcsc->nwait--;                                                 \
} while (/* CONSTCOND */ 0)

/*
 * XDC_FREE: add iorq "N" to SC's free list
 */
#define XDC_FREE(SC, N)                                                 \
do {                                                                    \
        (SC)->freereq[(SC)->nfree++] = (N);                             \
        (SC)->reqs[N].mode = 0;                                         \
        if ((SC)->nfree == 1)                                           \
                wakeup(&(SC)->nfree);                                   \
} while (/* CONSTCOND */ 0)


/*
 * XDC_RQALLOC: allocate an iorq off the free list (assume nfree > 0).
 */
#define XDC_RQALLOC(XDCSC) (XDCSC)->freereq[--((XDCSC)->nfree)]

/*
 * XDC_GO: start iopb ADDR (DVMA addr in a u_long) on XDC
 */
#define XDC_GO(XDC, ADDR)                                               \
do {                                                                    \
        (XDC)->xdc_iopbaddr0 = ((ADDR) & 0xff);                         \
        (ADDR) = ((ADDR) >> 8);                                         \
        (XDC)->xdc_iopbaddr1 = ((ADDR) & 0xff);                         \
        (ADDR) = ((ADDR) >> 8);                                         \
        (XDC)->xdc_iopbaddr2 = ((ADDR) & 0xff);                         \
        (ADDR) = ((ADDR) >> 8);                                         \
        (XDC)->xdc_iopbaddr3 = (ADDR);                                  \
        (XDC)->xdc_iopbamod = XDC_ADDRMOD;                              \
        (XDC)->xdc_csr = XDC_ADDIOPB; /* go! */                         \
} while (/* CONSTCOND */ 0)

/*
 * XDC_WAIT: wait for XDC's csr "BITS" to come on in "TIME".
 *   LCV is a counter.  If it goes to zero then we timed out.
 */
#define XDC_WAIT(XDC, LCV, TIME, BITS)                                  \
do {                                                                    \
        (LCV) = (TIME);                                                 \
        while ((LCV) > 0) {                                             \
                if ((XDC)->xdc_csr & (BITS))                            \
                        break;                                          \
                (LCV) = (LCV) - 1;                                      \
                DELAY(1);                                               \
        }                                                               \
} while (/* CONSTCOND */ 0)

/*
 * XDC_DONE: don't need IORQ, get error code and free (done after xdc_cmd)
 */
#define XDC_DONE(SC,RQ,ER)                                              \
do {                                                                    \
        if ((RQ) == XD_ERR_FAIL) {                                      \
                (ER) = (RQ);                                            \
        } else {                                                        \
                if ((SC)->ndone-- == XDC_SUBWAITLIM)                    \
                wakeup(&(SC)->ndone);                                   \
                (ER) = (SC)->reqs[RQ].errno;                            \
                XDC_FREE((SC), (RQ));                                   \
        }                                                               \
} while (/* CONSTCOND */ 0)

/*
 * XDC_ADVANCE: advance iorq's pointers by a number of sectors
 */
#define XDC_ADVANCE(IORQ, N)                                            \
do {                                                                    \
        if (N) {                                                        \
                (IORQ)->sectcnt -= (N);                                 \
                (IORQ)->blockno += (N);                                 \
                (IORQ)->dbuf += ((N) * XDFM_BPS);                       \
        }                                                               \
} while (/* CONSTCOND */ 0)

/*
 * note - addresses you can sleep on:
 *   [1] & of xd_softc's "state" (waiting for a chance to attach a drive)
 *   [2] & of xdc_softc's "nfree" (waiting for a free iorq/iopb)
 *   [3] & of xdc_softc's "ndone" (waiting for number of done iorq/iopb's
 *                                 to drop below XDC_SUBWAITLIM)
 *   [4] & an iorq (waiting for an XD_SUB_WAIT iorq to finish)
 */


/*
 * function prototypes
 * "xdc_*" functions are internal, all others are external interfaces
 */

/* internals */
int     xdc_cmd(struct xdc_softc *, int, int, int, int, int, char *, int);
const char *xdc_e2str(int);
int     xdc_error(struct xdc_softc *, struct xd_iorq *, struct xd_iopb *, int,
            int);
int     xdc_ioctlcmd(struct xd_softc *, dev_t dev, struct xd_iocmd *);
void    xdc_perror(struct xd_iorq *, struct xd_iopb *, int);
int     xdc_piodriver(struct xdc_softc *, int, int);
int     xdc_remove_iorq(struct xdc_softc *);
int     xdc_reset(struct xdc_softc *, int, int, int, struct xd_softc *);
inline void xdc_rqinit(struct xd_iorq *, struct xdc_softc *, struct xd_softc *,
            int, u_long, int, void *, struct buf *);
void    xdc_rqtopb(struct xd_iorq *, struct xd_iopb *, int, int);
void    xdc_start(struct xdc_softc *, int);
int     xdc_startbuf(struct xdc_softc *, struct xd_softc *, struct buf *);
int     xdc_submit_iorq(struct xdc_softc *, int, int);
void    xdc_tick(void *);
void    xdc_xdreset(struct xdc_softc *, struct xd_softc *);

/* machine interrupt hook */
int     xdcintr(void *);

/* autoconf */
static int      xdcmatch(device_t, cfdata_t, void *);
static void     xdcattach(device_t, device_t, void *);
static int      xdc_print(void *, const char *);

static int      xdmatch(device_t, cfdata_t, void *);
static void     xdattach(device_t, device_t, void *);
static void     xd_init(struct xd_softc *);

static  void xddummystrat(struct buf *);
int     xdgetdisklabel(struct xd_softc *, void *);

/*
 * cfattach's: device driver interface to autoconfig
 */

CFATTACH_DECL_NEW(xdc, sizeof(struct xdc_softc),
    xdcmatch, xdcattach, NULL, NULL);

CFATTACH_DECL_NEW(xd, sizeof(struct xd_softc),
    xdmatch, xdattach, NULL, NULL);

struct xdc_attach_args {        /* this is the "aux" args to xdattach */
        int     driveno;        /* unit number */
        char    *dvmabuf;       /* scratch buffer for reading disk label */
        int     fullmode;       /* submit mode */
        int     booting;        /* are we booting or not? */
};

dev_type_open(xdopen);
dev_type_close(xdclose);
dev_type_read(xdread);
dev_type_write(xdwrite);
dev_type_ioctl(xdioctl);
dev_type_strategy(xdstrategy);
dev_type_dump(xddump);
dev_type_size(xdsize);

const struct bdevsw xd_bdevsw = {
        xdopen, xdclose, xdstrategy, xdioctl, xddump, xdsize, D_DISK
};

const struct cdevsw xd_cdevsw = {
        xdopen, xdclose, xdread, xdwrite, xdioctl,
        nostop, notty, nopoll, nommap, nokqfilter, D_DISK
};

/*
 * dkdriver
 */

struct dkdriver xddkdriver = { xdstrategy };

/*
 * start: disk label fix code (XXX)
 */

static void *xd_labeldata;

static void 
xddummystrat(struct buf *bp)
{
        if (bp->b_bcount != XDFM_BPS)
                panic("%s: b_bcount", __func__);
        memcpy(bp->b_data, xd_labeldata, XDFM_BPS);
        bp->b_oflags |= BO_DONE;
        bp->b_cflags &= ~BC_BUSY;
}

int 
xdgetdisklabel(struct xd_softc *xd, void *b)
{
        const char *err;
        struct sun_disklabel *sdl;

        /* We already have the label data in `b'; setup for dummy strategy */
        xd_labeldata = b;

        /* Required parameter for readdisklabel() */
        xd->sc_dk.dk_label->d_secsize = XDFM_BPS;

        err = readdisklabel(MAKEDISKDEV(0, device_unit(xd->sc_dev), RAW_PART),
            xddummystrat, xd->sc_dk.dk_label, xd->sc_dk.dk_cpulabel);
        if (err) {
                printf("%s: %s\n", device_xname(xd->sc_dev), err);
                return XD_ERR_FAIL;
        }

        /* Ok, we have the label; fill in `pcyl' if there's SunOS magic */
        sdl = (struct sun_disklabel *)xd->sc_dk.dk_cpulabel->cd_block;
        if (sdl->sl_magic == SUN_DKMAGIC)
                xd->pcyl = sdl->sl_pcyl;
        else {
                printf("%s: WARNING: no `pcyl' in disk label.\n",
                    device_xname(xd->sc_dev));
                xd->pcyl = xd->sc_dk.dk_label->d_ncylinders +
                    xd->sc_dk.dk_label->d_acylinders;
                printf("%s: WARNING: guessing pcyl=%d (ncyl+acyl)\n",
                    device_xname(xd->sc_dev), xd->pcyl);
        }

        xd->ncyl = xd->sc_dk.dk_label->d_ncylinders;
        xd->acyl = xd->sc_dk.dk_label->d_acylinders;
        xd->nhead = xd->sc_dk.dk_label->d_ntracks;
        xd->nsect = xd->sc_dk.dk_label->d_nsectors;
        xd->sectpercyl = xd->nhead * xd->nsect;
        xd->sc_dk.dk_label->d_secsize = XDFM_BPS; /* not handled by
                                                  * sun->bsd */
        return XD_ERR_AOK;
}

/*
 * end: disk label fix code (XXX)
 */

/*
 * a u t o c o n f i g   f u n c t i o n s
 */

/*
 * xdcmatch: determine if xdc is present or not.   we do a
 * soft reset to detect the xdc.
 */

int 
xdcmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct confargs *ca = aux;

        /* No default VME address. */
        if (ca->ca_paddr == -1)
                return 0;

        /* Make sure something is there... */
        if (bus_peek(ca->ca_bustype, ca->ca_paddr + 11, 1) == -1)
                return 0;

        /* Default interrupt priority. */
        if (ca->ca_intpri == -1)
                ca->ca_intpri = 2;

        return 1;
}

/*
 * xdcattach: attach controller
 */
void 
xdcattach(device_t parent, device_t self, void *aux)
{
        struct xdc_softc *xdc = device_private(self);
        struct confargs *ca = aux;
        struct xdc_attach_args xa;
        int lcv, rqno, err;
        struct xd_iopb_ctrl *ctl;

        /* get addressing and intr level stuff from autoconfig and load it
         * into our xdc_softc. */

        xdc->sc_dev = self;
        xdc->xdc = (struct xdc *)bus_mapin(ca->ca_bustype, ca->ca_paddr,
            sizeof(struct xdc));
        xdc->bustype = ca->ca_bustype;
        xdc->ipl     = ca->ca_intpri;
        xdc->vector  = ca->ca_intvec;

        for (lcv = 0; lcv < XDC_MAXDEV; lcv++)
                xdc->sc_drives[lcv] = NULL;

        /* allocate and zero buffers
         *
         * note: we simplify the code by allocating the max number of iopbs and
         * iorq's up front.   thus, we avoid linked lists and the costs
         * associated with them in exchange for wasting a little memory. */

        xdc->iopbase = (struct xd_iopb *)dvma_malloc(XDC_MAXIOPB *
            sizeof(struct xd_iopb));    /* KVA */
        memset(xdc->iopbase, 0, XDC_MAXIOPB * sizeof(struct xd_iopb));
        xdc->dvmaiopb = (struct xd_iopb *)dvma_kvtopa(xdc->iopbase,
            xdc->bustype);
        xdc->reqs = malloc(XDC_MAXIOPB * sizeof(struct xd_iorq),
            M_DEVBUF, M_NOWAIT | M_ZERO);
        if (xdc->reqs == NULL)
                panic("xdc malloc");

        /* init free list, iorq to iopb pointers, and non-zero fields in the
         * iopb which never change. */

        for (lcv = 0; lcv < XDC_MAXIOPB; lcv++) {
                xdc->reqs[lcv].iopb = &xdc->iopbase[lcv];
                xdc->freereq[lcv] = lcv;
                xdc->iopbase[lcv].fixd = 1;     /* always the same */
                xdc->iopbase[lcv].naddrmod = XDC_ADDRMOD; /* always the same */
                xdc->iopbase[lcv].intr_vec = xdc->vector; /* always the same */
        }
        xdc->nfree = XDC_MAXIOPB;
        xdc->nrun = 0;
        xdc->waithead = xdc->waitend = xdc->nwait = 0;
        xdc->ndone = 0;

        /* init queue of waiting bufs */

        bufq_alloc(&xdc->sc_wq, "fcfs", 0);
        callout_init(&xdc->sc_tick_ch, 0);

        /*
         * section 7 of the manual tells us how to init the controller:
         * - read controller parameters (6/0)
         * - write controller parameters (5/0)
         */

        /* read controller parameters and insure we have a 753/7053 */

        rqno = xdc_cmd(xdc, XDCMD_RDP, XDFUN_CTL, 0, 0, 0, 0, XD_SUB_POLL);
        if (rqno == XD_ERR_FAIL) {
                aprint_error(": couldn't read controller params\n");
                return;         /* shouldn't ever happen */
        }
        ctl = (struct xd_iopb_ctrl *)&xdc->iopbase[rqno];
        if (ctl->ctype != XDCT_753) {
                if (xdc->reqs[rqno].errno)
                        aprint_error(": %s: ",
                            xdc_e2str(xdc->reqs[rqno].errno));
                aprint_error(": doesn't identify as a 753/7053\n");
                XDC_DONE(xdc, rqno, err);
                return;
        }
        aprint_normal(": Xylogics 753/7053, PROM=0x%x.%02x.%02x\n",
            ctl->eprom_partno, ctl->eprom_lvl, ctl->eprom_rev);
        XDC_DONE(xdc, rqno, err);

        /* now write controller parameters (xdc_cmd sets all params for us) */

        rqno = xdc_cmd(xdc, XDCMD_WRP, XDFUN_CTL, 0, 0, 0, 0, XD_SUB_POLL);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                aprint_error_dev(self, "controller config error: %s\n",
                    xdc_e2str(err));
                return;
        }

        /* link in interrupt with higher level software */
        isr_add_vectored(xdcintr, xdc, ca->ca_intpri, ca->ca_intvec);
        evcnt_attach_dynamic(&xdc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
            device_xname(self), "intr");

        /* now we must look for disks using autoconfig */
        xa.booting = 1;
        for (xa.driveno = 0; xa.driveno < XDC_MAXDEV; xa.driveno++)
                (void)config_found(self, (void *)&xa, xdc_print);

        /* start the watchdog clock */
        callout_reset(&xdc->sc_tick_ch, XDC_TICKCNT, xdc_tick, xdc);
}

int 
xdc_print(void *aux, const char *name)
{
        struct xdc_attach_args *xa = aux;

        if (name != NULL)
                aprint_normal("%s: ", name);

        if (xa->driveno != -1)
                aprint_normal(" drive %d", xa->driveno);

        return UNCONF;
}

/*
 * xdmatch: probe for disk.
 *
 * note: we almost always say disk is present.   this allows us to
 * spin up and configure a disk after the system is booted (we can
 * call xdattach!).  Also, wire down the relationship between the
 * xd* and xdc* devices, to simplify boot device identification.
 */
int 
xdmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct xdc_attach_args *xa = aux;
        int xd_unit;

        /* Match only on the "wired-down" controller+disk. */
        xd_unit = device_unit(parent) * 2 + xa->driveno;
        if (cf->cf_unit != xd_unit)
                return 0;

        return 1;
}

/*
 * xdattach: attach a disk.
 */
void 
xdattach(device_t parent, device_t self, void *aux)
{
        struct xd_softc *xd = device_private(self);
        struct xdc_softc *xdc = device_private(parent);
        struct xdc_attach_args *xa = aux;

        xd->sc_dev = self;
        aprint_normal("\n");

        /*
         * Always re-initialize the disk structure.  We want statistics
         * to start with a clean slate.
         */
        memset(&xd->sc_dk, 0, sizeof(xd->sc_dk));
        disk_init(&xd->sc_dk, device_xname(self), &xddkdriver);

        xd->state = XD_DRIVE_UNKNOWN;   /* to start */
        xd->flags = 0;
        xd->parent = xdc;

        xd->xd_drive = xa->driveno;
        xdc->sc_drives[xa->driveno] = xd;

        /* Do init work common to attach and open. */
        xd_init(xd);
}

/*
 * end of autoconfig functions
 */

/*
 * Initialize a disk.  This can be called from both autoconf and
 * also from xdopen/xdstrategy.
 */
static void 
xd_init(struct xd_softc *xd)
{
        struct xdc_softc *xdc;
        struct dkbad *dkb;
        struct xd_iopb_drive *driopb;
        void *dvmabuf;
        int rqno, err, spt, mb, blk, lcv, fullmode, newstate;

        xdc = xd->parent;
        xd->state = XD_DRIVE_ATTACHING;
        newstate = XD_DRIVE_UNKNOWN;
        fullmode = (cold) ? XD_SUB_POLL : XD_SUB_WAIT;
        dvmabuf = dvma_malloc(XDFM_BPS);

        /* first try and reset the drive */
        rqno = xdc_cmd(xdc, XDCMD_RST, 0, xd->xd_drive, 0, 0, 0, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err == XD_ERR_NRDY) {
                printf("%s: drive %d: off-line\n",
                    device_xname(xd->sc_dev), xd->xd_drive);
                goto done;
        }
        if (err) {
                printf("%s: ERROR 0x%02x (%s)\n",
                    device_xname(xd->sc_dev), err, xdc_e2str(err));
                goto done;
        }
        printf("%s: drive %d ready\n",
            device_xname(xd->sc_dev), xd->xd_drive);

        /* now set format parameters */

        rqno = xdc_cmd(xdc, XDCMD_WRP, XDFUN_FMT, xd->xd_drive,
            0, 0, 0, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: write format parameters failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }

        /* get drive parameters */
        spt = 0;
        rqno = xdc_cmd(xdc, XDCMD_RDP, XDFUN_DRV, xd->xd_drive,
            0, 0, 0, fullmode);
        if (rqno != XD_ERR_FAIL) {
                driopb = (struct xd_iopb_drive *)&xdc->iopbase[rqno];
                spt = driopb->sectpertrk;
        }
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: read drive parameters failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }

        /*
         * now set drive parameters (to semi-bogus values) so we can read the
         * disk label.
         */
        xd->pcyl = xd->ncyl = 1;
        xd->acyl = 0;
        xd->nhead = 1;
        xd->nsect = 1;
        xd->sectpercyl = 1;
        for (lcv = 0; lcv < 126; lcv++) /* init empty bad144 table */
                xd->dkb.bt_bad[lcv].bt_cyl =
                    xd->dkb.bt_bad[lcv].bt_trksec = 0xffff;
        rqno = xdc_cmd(xdc, XDCMD_WRP, XDFUN_DRV, xd->xd_drive,
            0, 0, 0, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: write drive parameters failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }

        /* read disk label */
        rqno = xdc_cmd(xdc, XDCMD_RD, 0, xd->xd_drive,
            0, 1, dvmabuf, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: reading disk label failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }
        newstate = XD_DRIVE_NOLABEL;

        xd->hw_spt = spt;
        /* Attach the disk: must be before getdisklabel to malloc label */
        disk_attach(&xd->sc_dk);

        if (xdgetdisklabel(xd, dvmabuf) != XD_ERR_AOK)
                goto done;

        /* inform the user of what is up */
        printf("%s: <%s>, pcyl %d, hw_spt %d\n",
            device_xname(xd->sc_dev), (char *)dvmabuf, xd->pcyl, spt);
        mb = xd->ncyl * (xd->nhead * xd->nsect) / (1048576 / XDFM_BPS);
        printf("%s: %dMB, %d cyl, %d head, %d sec\n",
            device_xname(xd->sc_dev), mb,
            xd->ncyl, xd->nhead, xd->nsect);

        /* now set the real drive parameters! */
        rqno = xdc_cmd(xdc, XDCMD_WRP, XDFUN_DRV, xd->xd_drive,
            0, 0, 0, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: write real drive parameters failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }
        newstate = XD_DRIVE_ONLINE;

        /*
         * read bad144 table. this table resides on the first sector of the
         * last track of the disk (i.e. second cyl of "acyl" area).
         */
        blk = (xd->ncyl + xd->acyl - 1) * (xd->nhead * xd->nsect) + /* last cyl */
            (xd->nhead - 1) * xd->nsect;        /* last head */
        rqno = xdc_cmd(xdc, XDCMD_RD, 0, xd->xd_drive,
                                   blk, 1, dvmabuf, fullmode);
        XDC_DONE(xdc, rqno, err);
        if (err) {
                printf("%s: reading bad144 failed: %s\n",
                    device_xname(xd->sc_dev), xdc_e2str(err));
                goto done;
        }

        /* check dkbad for sanity */
        dkb = (struct dkbad *)dvmabuf;
        for (lcv = 0; lcv < 126; lcv++) {
                if ((dkb->bt_bad[lcv].bt_cyl == 0xffff ||
                    dkb->bt_bad[lcv].bt_cyl == 0) &&
                    dkb->bt_bad[lcv].bt_trksec == 0xffff)
                        continue;       /* blank */
                if (dkb->bt_bad[lcv].bt_cyl >= xd->ncyl)
                        break;
                if ((dkb->bt_bad[lcv].bt_trksec >> 8) >= xd->nhead)
                        break;
                if ((dkb->bt_bad[lcv].bt_trksec & 0xff) >= xd->nsect)
                        break;
        }
        if (lcv != 126) {
                printf("%s: warning: invalid bad144 sector!\n",
                    device_xname(xd->sc_dev));
        } else {
                memcpy(&xd->dkb, dvmabuf, XDFM_BPS);
        }

 done:
        xd->state = newstate;
        dvma_free(dvmabuf, XDFM_BPS);
}

/*
 * { b , c } d e v s w   f u n c t i o n s
 */

/*
 * xdclose: close device
 */
int 
xdclose(dev_t dev, int flag, int fmt, struct lwp *l)
{
        struct xd_softc *xd = device_lookup_private(&xd_cd, DISKUNIT(dev));
        int part = DISKPART(dev);

        /* clear mask bits */

        switch (fmt) {
        case S_IFCHR:
                xd->sc_dk.dk_copenmask &= ~(1 << part);
                break;
        case S_IFBLK:
                xd->sc_dk.dk_bopenmask &= ~(1 << part);
                break;
        }
        xd->sc_dk.dk_openmask = xd->sc_dk.dk_copenmask | xd->sc_dk.dk_bopenmask;

        return 0;
}

/*
 * xddump: crash dump system
 */
int 
xddump(dev_t dev, daddr_t blkno, void *va, size_t sz)
{
        int unit, part;
        struct xd_softc *xd;

        unit = DISKUNIT(dev);
        part = DISKPART(dev);

        xd = device_lookup_private(&xd_cd, unit);
        if (xd == NULL)
                return ENXIO;

        printf("%s%c: crash dump not supported (yet)\n",
            device_xname(xd->sc_dev), 'a' + part);

        return ENXIO;

        /* outline: globals: "dumplo" == sector number of partition to start
         * dump at (convert to physical sector with partition table)
         * "dumpsize" == size of dump in clicks "physmem" == size of physical
         * memory (clicks, ctob() to get bytes) (normal case: dumpsize ==
         * physmem)
         *
         * dump a copy of physical memory to the dump device starting at sector
         * "dumplo" in the swap partition (make sure > 0).   map in pages as
         * we go.   use polled I/O.
         *
         * XXX how to handle NON_CONTIG?
         */
}

static enum kauth_device_req
xd_getkauthreq(u_char cmd)
{
        enum kauth_device_req req;

        switch (cmd) {
        case XDCMD_WR:
        case XDCMD_XWR:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITE;
                break;

        case XDCMD_RD:
        case XDCMD_XRD:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READ;
                break;

        case XDCMD_RDP:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF;
                break;

        case XDCMD_WRP:
        case XDCMD_RST:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF;
                break;

        case XDCMD_NOP:
        case XDCMD_SK:
        case XDCMD_TST:
        default:
                req = 0;
                break;
        }

        return req;
}

/*
 * xdioctl: ioctls on XD drives.   based on ioctl's of other netbsd disks.
 */
int 
xdioctl(dev_t dev, u_long command, void *addr, int flag, struct lwp *l)
{
        struct xd_softc *xd;
        struct xd_iocmd *xio;
        int     error, s, unit;

        unit = DISKUNIT(dev);

        xd = device_lookup_private(&xd_cd, unit);
        if (xd == NULL)
                return (ENXIO);

        /* switch on ioctl type */

        switch (command) {
        case DIOCSBAD:          /* set bad144 info */
                if ((flag & FWRITE) == 0)
                        return EBADF;
                s = splbio();
                memcpy(&xd->dkb, addr, sizeof(xd->dkb));
                splx(s);
                return 0;

        case DIOCGDINFO:        /* get disk label */
                memcpy(addr, xd->sc_dk.dk_label, sizeof(struct disklabel));
                return 0;

        case DIOCGPART: /* get partition info */
                ((struct partinfo *)addr)->disklab = xd->sc_dk.dk_label;
                ((struct partinfo *)addr)->part =
                    &xd->sc_dk.dk_label->d_partitions[DISKPART(dev)];
                return 0;

        case DIOCSDINFO:        /* set disk label */
                if ((flag & FWRITE) == 0)
                        return EBADF;
                error = setdisklabel(xd->sc_dk.dk_label,
                    (struct disklabel *)addr, /* xd->sc_dk.dk_openmask : */ 0,
                    xd->sc_dk.dk_cpulabel);
                if (error == 0) {
                        if (xd->state == XD_DRIVE_NOLABEL)
                                xd->state = XD_DRIVE_ONLINE;
                }
                return error;

        case DIOCWLABEL:        /* change write status of disk label */
                if ((flag & FWRITE) == 0)
                        return EBADF;
                if (*(int *)addr)
                        xd->flags |= XD_WLABEL;
                else
                        xd->flags &= ~XD_WLABEL;
                return 0;

        case DIOCWDINFO:        /* write disk label */
                if ((flag & FWRITE) == 0)
                        return EBADF;
                error = setdisklabel(xd->sc_dk.dk_label,
                    (struct disklabel *)addr, /* xd->sc_dk.dk_openmask : */ 0,
                    xd->sc_dk.dk_cpulabel);
                if (error == 0) {
                        if (xd->state == XD_DRIVE_NOLABEL)
                                xd->state = XD_DRIVE_ONLINE;

                        /* Simulate opening partition 0 so write succeeds. */
                        xd->sc_dk.dk_openmask |= (1 << 0);
                        error = writedisklabel(MAKEDISKDEV(major(dev),
                            DISKUNIT(dev), RAW_PART),
                            xdstrategy, xd->sc_dk.dk_label,
                            xd->sc_dk.dk_cpulabel);
                        xd->sc_dk.dk_openmask =
                            xd->sc_dk.dk_copenmask | xd->sc_dk.dk_bopenmask;
                }
                return error;

        case DIOSXDCMD: {
                enum kauth_device_req req;

                xio = (struct xd_iocmd *)addr;
                req = xd_getkauthreq(xio->cmd);
                if ((error = kauth_authorize_device_passthru(l->l_cred,
                    dev, req, xio)) != 0)
                        return error;
                return xdc_ioctlcmd(xd, dev, xio);
                }

        default:
                return ENOTTY;
        }
}

/*
 * xdopen: open drive
 */
int 
xdopen(dev_t dev, int flag, int fmt, struct lwp *l)
{
        int err, unit, part, s;
        struct xd_softc *xd;

        /* first, could it be a valid target? */
        unit = DISKUNIT(dev);
        xd = device_lookup_private(&xd_cd, unit);
        if (xd == NULL)
                return ENXIO;
        part = DISKPART(dev);
        err = 0;

        /*
         * If some other processing is doing init, sleep.
         */
        s = splbio();
        while (xd->state == XD_DRIVE_ATTACHING) {
                if (tsleep(&xd->state, PRIBIO, "xdopen", 0)) {
                        err = EINTR;
                        goto done;
                }
        }
        /* Do we need to init the drive? */
        if (xd->state == XD_DRIVE_UNKNOWN) {
                xd_init(xd);
                wakeup(&xd->state);
        }
        /* Was the init successful? */
        if (xd->state == XD_DRIVE_UNKNOWN) {
                err = EIO;
                goto done;
        }

        /* check for partition */
        if (part != RAW_PART &&
            (part >= xd->sc_dk.dk_label->d_npartitions ||
                xd->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
                err = ENXIO;
                goto done;
        }

        /* set open masks */
        switch (fmt) {
        case S_IFCHR:
                xd->sc_dk.dk_copenmask |= (1 << part);
                break;
        case S_IFBLK:
                xd->sc_dk.dk_bopenmask |= (1 << part);
                break;
        }
        xd->sc_dk.dk_openmask = xd->sc_dk.dk_copenmask | xd->sc_dk.dk_bopenmask;

 done:
        splx(s);
        return err;
}

int 
xdread(dev_t dev, struct uio *uio, int flags)
{

        return physio(xdstrategy, NULL, dev, B_READ, minphys, uio);
}

int 
xdwrite(dev_t dev, struct uio *uio, int flags)
{

        return physio(xdstrategy, NULL, dev, B_WRITE, minphys, uio);
}


/*
 * xdsize: return size of a partition for a dump
 */
int 
xdsize(dev_t dev)
{
        struct xd_softc *xdsc;
        int unit, part, size, omask;

        /* valid unit? */
        unit = DISKUNIT(dev);
        xdsc = device_lookup_private(&xd_cd, unit);
        if (xdsc == NULL)
                return -1;

        part = DISKPART(dev);
        omask = xdsc->sc_dk.dk_openmask & (1 << part);

        if (omask == 0 && xdopen(dev, 0, S_IFBLK, NULL) != 0)
                return -1;

        /* do it */
        if (xdsc->sc_dk.dk_label->d_partitions[part].p_fstype != FS_SWAP)
                size = -1;      /* only give valid size for swap partitions */
        else
                size = xdsc->sc_dk.dk_label->d_partitions[part].p_size *
                    (xdsc->sc_dk.dk_label->d_secsize / DEV_BSIZE);
        if (omask == 0 && xdclose(dev, 0, S_IFBLK, NULL) != 0)
                return -1;
        return size;
}

/*
 * xdstrategy: buffering system interface to xd.
 */
void 
xdstrategy(struct buf *bp)
{
        struct xd_softc *xd;
        struct xdc_softc *parent;
        int s, unit;

        unit = DISKUNIT(bp->b_dev);

        /* check for live device */

        xd = device_lookup_private(&xd_cd, unit);
        if (xd == NULL ||
            bp->b_blkno < 0 ||
            (bp->b_bcount % xd->sc_dk.dk_label->d_secsize) != 0) {
                bp->b_error = EINVAL;
                goto done;
        }

        /* There should always be an open first. */
        if (xd->state == XD_DRIVE_UNKNOWN) {
                bp->b_error = EIO;
                goto done;
        }

        if (xd->state != XD_DRIVE_ONLINE && DISKPART(bp->b_dev) != RAW_PART) {
                /* no I/O to unlabeled disks, unless raw partition */
                bp->b_error = EIO;
                goto done;
        }
        /* short circuit zero length request */

        if (bp->b_bcount == 0)
                goto done;

        /* check bounds with label (disksubr.c).  Determine the size of the
         * transfer, and make sure it is within the boundaries of the
         * partition. Adjust transfer if needed, and signal errors or early
         * completion. */

        if (bounds_check_with_label(&xd->sc_dk, bp,
                (xd->flags & XD_WLABEL) != 0) <= 0)
                goto done;

        /*
         * now we know we have a valid buf structure that we need to do I/O
         * on.
         *
         * note that we don't disksort because the controller has a sorting
         * algorithm built into the hardware.
         */

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

        /* first, give jobs in front of us a chance */
        parent = xd->parent;
        while (parent->nfree > 0 && bufq_peek(parent->sc_wq) != NULL)
                if (xdc_startbuf(parent, NULL, NULL) != XD_ERR_AOK)
                        break;

        /*
         * if there are no free iorq's, then we just queue and return. the
         * buffs will get picked up later by xdcintr().
         */
        if (parent->nfree == 0) {
                bufq_put(parent->sc_wq, bp);
                splx(s);
                return;
        }

        /* now we have free iopb's and we are at splbio... start 'em up */
        if (xdc_startbuf(parent, xd, bp) != XD_ERR_AOK) {
                return;
        }

        /* done! */

        splx(s);
        return;

 done:
        /* tells upper layers we are done with this buf */
        bp->b_resid = bp->b_bcount;
        biodone(bp);
}
/*
 * end of {b,c}devsw functions
 */

/*
 * i n t e r r u p t   f u n c t i o n
 *
 * xdcintr: hardware interrupt.
 */
int 
xdcintr(void *v)
{
        struct xdc_softc *xdcsc = v;

        /* kick the event counter */
        xdcsc->sc_intrcnt.ev_count++;

        /* remove as many done IOPBs as possible */
        xdc_remove_iorq(xdcsc);

        /* start any iorq's already waiting */
        xdc_start(xdcsc, XDC_MAXIOPB);

        /* fill up any remaining iorq's with queue'd buffers */
        while (xdcsc->nfree > 0 && bufq_peek(xdcsc->sc_wq) != NULL)
                if (xdc_startbuf(xdcsc, NULL, NULL) != XD_ERR_AOK)
                        break;

        return 1;
}
/*
 * end of interrupt function
 */

/*
 * i n t e r n a l   f u n c t i o n s
 */

/*
 * xdc_rqinit: fill out the fields of an I/O request
 */

inline void 
xdc_rqinit(struct xd_iorq *rq, struct xdc_softc *xdc, struct xd_softc *xd,
    int md, u_long blk, int cnt, void *db, struct buf *bp)
{

        rq->xdc = xdc;
        rq->xd = xd;
        rq->ttl = XDC_MAXTTL + 10;
        rq->mode = md;
        rq->tries = rq->errno = rq->lasterror = 0;
        rq->blockno = blk;
        rq->sectcnt = cnt;
        rq->dbuf = rq->dbufbase = db;
        rq->buf = bp;
}

/*
 * xdc_rqtopb: load up an IOPB based on an iorq
 */
void 
xdc_rqtopb(struct xd_iorq *iorq, struct xd_iopb *iopb, int cmd, int subfun)
{
        u_long  block, dp;

        /* standard stuff */

        iopb->errs = iopb->done = 0;
        iopb->comm = cmd;
        iopb->errno = iopb->status = 0;
        iopb->subfun = subfun;
        if (iorq->xd)
                iopb->unit = iorq->xd->xd_drive;
        else
                iopb->unit = 0;

        /* check for alternate IOPB format */

        if (cmd == XDCMD_WRP) {
                switch (subfun) {
                case XDFUN_CTL:{
                        struct xd_iopb_ctrl *ctrl =
                            (struct xd_iopb_ctrl *)iopb;
                        iopb->lll = 0;
                        iopb->intl = (XD_STATE(iorq->mode) == XD_SUB_POLL)
                            ? 0 : iorq->xdc->ipl;
                        ctrl->param_a = XDPA_TMOD | XDPA_DACF;
                        ctrl->param_b = XDPB_ROR | XDPB_TDT_3_2USEC;
                        ctrl->param_c = XDPC_OVS | XDPC_COP | XDPC_ASR |
                            XDPC_RBC | XDPC_ECC2;
                        ctrl->throttle = XDC_THROTTLE;
#ifdef sparc
                        if (CPU_ISSUN4 && cpuinfo.cpu_type == CPUTYP_4_300)
                                ctrl->delay = XDC_DELAY_4_300;
                        else
                                ctrl->delay = XDC_DELAY_SPARC;
#endif
#ifdef sun3
                        ctrl->delay = XDC_DELAY_SUN3;
#endif
                        break;
                        }
                case XDFUN_DRV:{
                        struct xd_iopb_drive *drv =
                            (struct xd_iopb_drive *)iopb;
                        /* we assume that the disk label has the right
                         * info */
                        if (XD_STATE(iorq->mode) == XD_SUB_POLL)
                                drv->dparam_ipl = (XDC_DPARAM << 3);
                        else
                                drv->dparam_ipl = (XDC_DPARAM << 3) |
                                    iorq->xdc->ipl;
                        drv->maxsect = iorq->xd->nsect - 1;
                        drv->maxsector = drv->maxsect;
                        /* note: maxsector != maxsect only if you are
                         * doing cyl sparing */
                        drv->headoff = 0;
                        drv->maxcyl = iorq->xd->pcyl - 1;
                        drv->maxhead = iorq->xd->nhead - 1;
                        break;
                        }
                case XDFUN_FMT:
                    {
                        struct xd_iopb_format *form =
                            (struct xd_iopb_format *)iopb;

                        if (XD_STATE(iorq->mode) == XD_SUB_POLL)
                                form->interleave_ipl = (XDC_INTERLEAVE << 3);
                        else
                                form->interleave_ipl = (XDC_INTERLEAVE << 3) |
                                    iorq->xdc->ipl;
                        form->field1 = XDFM_FIELD1;
                        form->field2 = XDFM_FIELD2;
                        form->field3 = XDFM_FIELD3;
                        form->field4 = XDFM_FIELD4;
                        form->bytespersec = XDFM_BPS;
                        form->field6 = XDFM_FIELD6;
                        form->field7 = XDFM_FIELD7;
                        break;
                    }
                }
        } else {

                /* normal IOPB case (harmless to RDP command) */

                iopb->lll = 0;
                iopb->intl = (XD_STATE(iorq->mode) == XD_SUB_POLL)
                    ? 0 : iorq->xdc->ipl;
                iopb->sectcnt = iorq->sectcnt;
                block = iorq->blockno;
                if (iorq->xd == NULL || block == 0) {
                        iopb->sectno = iopb->headno = iopb->cylno = 0;
                } else {
                        iopb->sectno = block % iorq->xd->nsect;
                        block = block / iorq->xd->nsect;
                        iopb->headno = block % iorq->xd->nhead;
                        block = block / iorq->xd->nhead;
                        iopb->cylno = block;
                }
                iopb->daddr = dp = (iorq->dbuf == NULL) ? 0 :
                    dvma_kvtopa(iorq->dbuf, iorq->xdc->bustype);
                iopb->addrmod = XDC_ADDRMOD;
        }
}

/*
 * xdc_cmd: front end for POLL'd and WAIT'd commands.  Returns rqno.
 * If you've already got an IORQ, you can call submit directly (currently
 * there is no need to do this).    NORM requests are handled separately.
 */
int 
xdc_cmd(struct xdc_softc *xdcsc, int cmd, int subfn, int unit, int block,
    int scnt, char *dptr, int fullmode)
{
        struct xd_iorq *iorq;
        struct xd_iopb *iopb;
        int rqno, retry;
        int submode = XD_STATE(fullmode);

        /* get iorq/iopb */
        switch (submode) {
        case XD_SUB_POLL:
                while (xdcsc->nfree == 0) {
                        if (xdc_piodriver(xdcsc, 0, 1) != XD_ERR_AOK)
                                return XD_ERR_FAIL;
                }
                break;
        case XD_SUB_WAIT:
                retry = 1;
                while (retry) {
                        while (xdcsc->nfree == 0) {
                            if (tsleep(&xdcsc->nfree, PRIBIO, "xdnfree", 0))
                                return XD_ERR_FAIL;
                        }
                        while (xdcsc->ndone > XDC_SUBWAITLIM) {
                            if (tsleep(&xdcsc->ndone, PRIBIO, "xdsubwait", 0))
                                return XD_ERR_FAIL;
                        }
                        if (xdcsc->nfree)
                                retry = 0;      /* got it */
                }
                break;
        default:
                return XD_ERR_FAIL;     /* illegal */
        }
        if (xdcsc->nfree == 0)
                panic("xdcmd nfree");
        rqno = XDC_RQALLOC(xdcsc);
        iorq = &xdcsc->reqs[rqno];
        iopb = iorq->iopb;


        /* init iorq/iopb */
        xdc_rqinit(iorq, xdcsc,
            (unit == XDC_NOUNIT) ? NULL : xdcsc->sc_drives[unit],
            fullmode, block, scnt, dptr, NULL);

        /* load IOPB from iorq */
        xdc_rqtopb(iorq, iopb, cmd, subfn);

        /* submit it for processing */
        xdc_submit_iorq(xdcsc, rqno, fullmode); /* error code will be in iorq */

        return rqno;
}

/*
 * xdc_startbuf
 * start a buffer running, assumes nfree > 0
 */
int 
xdc_startbuf(struct xdc_softc *xdcsc, struct xd_softc *xdsc, struct buf *bp)
{
        int rqno, partno;
        struct xd_iorq *iorq;
        struct xd_iopb *iopb;
        u_long  block;
        void *dbuf;

        if (xdcsc->nfree == 0)
                panic("xdc_startbuf free");
        rqno = XDC_RQALLOC(xdcsc);
        iorq = &xdcsc->reqs[rqno];
        iopb = iorq->iopb;

        /* get buf */

        if (bp == NULL) {
                bp = bufq_get(xdcsc->sc_wq);
                if (bp == NULL)
                        panic("%s bp", __func__);
                xdsc = xdcsc->sc_drives[DISKUNIT(bp->b_dev)];
        }
        partno = DISKPART(bp->b_dev);
#ifdef XDC_DEBUG
        printf("xdc_startbuf: %s%c: %s block %d\n", device_xname(xdsc->sc_dev),
            'a' + partno, (bp->b_flags & B_READ) ? "read" : "write", bp->b_blkno);
        printf("%s: b_bcount %d, b_data 0x%x\n", __func__,
            bp->b_bcount, bp->b_data);
#endif

        /*
         * load request.  we have to calculate the correct block number based
         * on partition info.
         *
         * also, note that there are two kinds of buf structures, those with
         * B_PHYS set and those without B_PHYS.   if B_PHYS is set, then it is
         * a raw I/O (to a cdevsw) and we are doing I/O directly to the users'
         * buffer which has already been mapped into DVMA space. (Not on sun3)
         * However, if B_PHYS is not set, then the buffer is a normal system
         * buffer which does *not* live in DVMA space.  In that case we call
         * dvma_mapin to map it into DVMA space so we can do the DMA to it.
         *
         * in cases where we do a dvma_mapin, note that iorq points to the
         * buffer as mapped into DVMA space, where as the bp->b_data points
         * to its non-DVMA mapping.
         *
         * XXX - On the sun3, B_PHYS does NOT mean the buffer is mapped
         * into dvma space, only that it was remapped into the kernel.
         * We ALWAYS have to remap the kernel buf into DVMA space.
         * (It is done inexpensively, using whole segments!)
         */

        block = bp->b_blkno + ((partno == RAW_PART) ? 0 :
            xdsc->sc_dk.dk_label->d_partitions[partno].p_offset);

        dbuf = dvma_mapin(bp->b_data, bp->b_bcount, 0);
        if (dbuf == NULL) {     /* out of DVMA space */
                printf("%s: warning: out of DVMA space\n",
                    device_xname(xdcsc->sc_dev));
                XDC_FREE(xdcsc, rqno);
                bufq_put(xdcsc->sc_wq, bp);
                return XD_ERR_FAIL;     /* XXX: need some sort of
                                         * call-back scheme here? */
        }

        /* init iorq and load iopb from it */

        xdc_rqinit(iorq, xdcsc, xdsc, XD_SUB_NORM | XD_MODE_VERBO, block,
            bp->b_bcount / XDFM_BPS, dbuf, bp);

        xdc_rqtopb(iorq, iopb, (bp->b_flags & B_READ) ? XDCMD_RD : XDCMD_WR, 0);

        /* Instrumentation. */
        disk_busy(&xdsc->sc_dk);

        /* now submit [note that xdc_submit_iorq can never fail on NORM reqs] */

        xdc_submit_iorq(xdcsc, rqno, XD_SUB_NORM);
        return XD_ERR_AOK;
}


/*
 * xdc_submit_iorq: submit an iorq for processing.  returns XD_ERR_AOK
 * if ok.  if it fail returns an error code.  type is XD_SUB_*.
 *
 * note: caller frees iorq in all cases except NORM
 *
 * return value:
 *   NORM: XD_AOK (req pending), XD_FAIL (couldn't submit request)
 *   WAIT: XD_AOK (success), <error-code> (failed)
 *   POLL: <same as WAIT>
 *   NOQ : <same as NORM>
 *
 * there are three sources for i/o requests:
 * [1] xdstrategy: normal block I/O, using "struct buf" system.
 * [2] autoconfig/crash dump: these are polled I/O requests, no interrupts.
 * [3] open/ioctl: these are I/O requests done in the context of a process,
 *                 and the process should block until they are done.
 *
 * software state is stored in the iorq structure.  each iorq has an
 * iopb structure.  the hardware understands the iopb structure.
 * every command must go through an iopb.  a 7053 can only handle
 * XDC_MAXIOPB (31) active iopbs at one time.  iopbs are allocated in
 * DVMA space at boot up time.  what happens if we run out of iopb's?
 * for i/o type [1], the buffers are queued at the "buff" layer and
 * picked up later by the interrupt routine.  for case [2] the
 * programmed i/o driver is called with a special flag that says
 * return when one iopb is free.  for case [3] the process can sleep
 * on the iorq free list until some iopbs are available.
 */

int 
xdc_submit_iorq(struct xdc_softc *xdcsc, int iorqno, int type)
{
        u_long  iopbaddr;
        struct xd_iorq *iorq = &xdcsc->reqs[iorqno];

#ifdef XDC_DEBUG
        printf("xdc_submit_iorq(%s, no=%d, type=%d)\n",
            device_xname(xdcsc->sc_dev), iorqno, type);
#endif

        /* first check and see if controller is busy */
        if (xdcsc->xdc->xdc_csr & XDC_ADDING) {
#ifdef XDC_DEBUG
                printf("%s: XDC not ready (ADDING)\n", __func__);
#endif
                if (type == XD_SUB_NOQ)
                        return XD_ERR_FAIL;     /* failed */
                XDC_TWAIT(xdcsc, iorqno);       /* put at end of waitq */
                switch (type) {
                case XD_SUB_NORM:
                        return XD_ERR_AOK;      /* success */
                case XD_SUB_WAIT:
                        while (iorq->iopb->done == 0) {
                                (void)tsleep(iorq, PRIBIO, "xdciorq", 0);
                        }
                        return iorq->errno;
                case XD_SUB_POLL:
                        return xdc_piodriver(xdcsc, iorqno, 0);
                default:
                        panic("%s adding", __func__);
                }
        }
#ifdef XDC_DEBUG
        {
                u_char *rio = (u_char *)iorq->iopb;
                int sz = sizeof(struct xd_iopb), lcv;
                printf("%s: aio #%d [",
                    device_xname(xdcsc->sc_dev), iorq - xdcsc->reqs);
                for (lcv = 0; lcv < sz; lcv++)
                        printf(" %02x", rio[lcv]);
                printf("]\n");
        }
#endif                          /* XDC_DEBUG */

        /* controller not busy, start command */
        iopbaddr = dvma_kvtopa(iorq->iopb, xdcsc->bustype);
        XDC_GO(xdcsc->xdc, iopbaddr);   /* go! */
        xdcsc->nrun++;
        /* command now running, wrap it up */
        switch (type) {
        case XD_SUB_NORM:
        case XD_SUB_NOQ:
                return XD_ERR_AOK;      /* success */
        case XD_SUB_WAIT:
                while (iorq->iopb->done == 0) {
                        (void)tsleep(iorq, PRIBIO, "xdciorq", 0);
                }
                return iorq->errno;
        case XD_SUB_POLL:
                return xdc_piodriver(xdcsc, iorqno, 0);
        default:
                panic("%s wrap up", __func__);
        }
        panic("%s: impossible", __func__);
        return 0;       /* not reached */
}


/*
 * xdc_piodriver
 *
 * programmed i/o driver.   this function takes over the computer
 * and drains off all i/o requests.   it returns the status of the iorq
 * the caller is interesting in.   if freeone is true, then it returns
 * when there is a free iorq.
 */
int 
xdc_piodriver(struct xdc_softc *xdcsc, int iorqno, int freeone)
{
        int nreset = 0;
        int retval = 0;
        u_long  count;
        struct xdc *xdc = xdcsc->xdc;
#ifdef XDC_DEBUG
        printf("%s(%s, %d, freeone=%d)\n", __func__,
            device_xname(xdcsc->sc_dev), iorqno, freeone);
#endif

        while (xdcsc->nwait || xdcsc->nrun) {
#ifdef XDC_DEBUG
                printf("%s: wait=%d, run=%d\n", __func__,
                    xdcsc->nwait, xdcsc->nrun);
#endif
                XDC_WAIT(xdc, count, XDC_MAXTIME, (XDC_REMIOPB | XDC_F_ERROR));
#ifdef XDC_DEBUG
                printf("%s: done wait with count = %d\n", __func__, count);
#endif
                /* we expect some progress soon */
                if (count == 0 && nreset >= 2) {
                        xdc_reset(xdcsc, 0, XD_RSET_ALL, XD_ERR_FAIL, 0);
#ifdef XDC_DEBUG
                        printf("%s: timeout\n", __func__);
#endif
                        return XD_ERR_FAIL;
                }
                if (count == 0) {
                        if (xdc_reset(xdcsc, 0,
                            (nreset++ == 0) ? XD_RSET_NONE : iorqno,
                            XD_ERR_FAIL, 0) == XD_ERR_FAIL)
                                return XD_ERR_FAIL;     /* flushes all but POLL
                                                         * requests, resets */
                        continue;
                }
                xdc_remove_iorq(xdcsc); /* could resubmit request */
                if (freeone) {
                        if (xdcsc->nrun < XDC_MAXIOPB) {
#ifdef XDC_DEBUG
                                printf("%s: done: one free\n", __func__);
#endif
                                return XD_ERR_AOK;
                        }
                        continue;       /* don't xdc_start */
                }
                xdc_start(xdcsc, XDC_MAXIOPB);
        }

        /* get return value */

        retval = xdcsc->reqs[iorqno].errno;

#ifdef XDC_DEBUG
        printf("%s: done, retval = 0x%x (%s)\n", __func__,
            xdcsc->reqs[iorqno].errno, xdc_e2str(xdcsc->reqs[iorqno].errno));
#endif

        /*
         * now that we've drained everything, start up any bufs that have
         * queued
         */

        while (xdcsc->nfree > 0 && bufq_peek(xdcsc->sc_wq) != NULL)
                if (xdc_startbuf(xdcsc, NULL, NULL) != XD_ERR_AOK)
                        break;

        return retval;
}

/*
 * xdc_reset: reset one drive.   NOTE: assumes xdc was just reset.
 * we steal iopb[0] for this, but we put it back when we are done.
 */
void 
xdc_xdreset(struct xdc_softc *xdcsc, struct xd_softc *xdsc)
{
        struct xd_iopb tmpiopb;
        u_long  addr;
        int del;

        memcpy(&tmpiopb, xdcsc->iopbase, sizeof(tmpiopb));
        memset(xdcsc->iopbase, 0, sizeof(tmpiopb));
        xdcsc->iopbase->comm = XDCMD_RST;
        xdcsc->iopbase->unit = xdsc->xd_drive;
        addr = (u_long)xdcsc->dvmaiopb;
        XDC_GO(xdcsc->xdc, addr);       /* go! */
        XDC_WAIT(xdcsc->xdc, del, XDC_RESETUSEC, XDC_REMIOPB);
        if (del <= 0 || xdcsc->iopbase->errs) {
                printf("%s: off-line: %s\n", device_xname(xdcsc->sc_dev),
                    xdc_e2str(xdcsc->iopbase->errno));
                xdcsc->xdc->xdc_csr = XDC_RESET;
                XDC_WAIT(xdcsc->xdc, del, XDC_RESETUSEC, XDC_RESET);
                if (del <= 0)
                        panic("%s", __func__);
        } else {
                xdcsc->xdc->xdc_csr = XDC_CLRRIO;       /* clear RIO */
        }
        memcpy(xdcsc->iopbase, &tmpiopb, sizeof(tmpiopb));
}


/*
 * xdc_reset: reset everything: requests are marked as errors except
 * a polled request (which is resubmitted)
 */
int 
xdc_reset(struct xdc_softc *xdcsc, int quiet, int blastmode, int error,
    struct xd_softc *xdsc)
{
        int del = 0, lcv, retval = XD_ERR_AOK;
        int oldfree = xdcsc->nfree;
        struct xd_iorq *iorq;

        /* soft reset hardware */

        if (quiet == 0)
                printf("%s: soft reset\n", device_xname(xdcsc->sc_dev));
        xdcsc->xdc->xdc_csr = XDC_RESET;
        XDC_WAIT(xdcsc->xdc, del, XDC_RESETUSEC, XDC_RESET);
        if (del <= 0) {
                blastmode = XD_RSET_ALL;        /* dead, flush all requests */
                retval = XD_ERR_FAIL;
        }
        if (xdsc)
                xdc_xdreset(xdcsc, xdsc);

        /* fix queues based on "blast-mode" */

        for (lcv = 0; lcv < XDC_MAXIOPB; lcv++) {
                iorq = &xdcsc->reqs[lcv];

                if (XD_STATE(iorq->mode) != XD_SUB_POLL &&
                    XD_STATE(iorq->mode) != XD_SUB_WAIT &&
                    XD_STATE(iorq->mode) != XD_SUB_NORM)
                        /* is it active? */
                        continue;

                xdcsc->nrun--;  /* it isn't running any more */
                if (blastmode == XD_RSET_ALL || blastmode != lcv) {
                        /* failed */
                        iorq->errno = error;
                        xdcsc->iopbase[lcv].done = xdcsc->iopbase[lcv].errs = 1;
                        switch (XD_STATE(iorq->mode)) {
                        case XD_SUB_NORM:
                                iorq->buf->b_error = EIO;
                                iorq->buf->b_resid = iorq->sectcnt * XDFM_BPS;
                                /* Sun3: map/unmap regardless of B_PHYS */
                                dvma_mapout(iorq->dbufbase,
                                    iorq->buf->b_bcount);
                                disk_unbusy(&iorq->xd->sc_dk,
                                    (iorq->buf->b_bcount - iorq->buf->b_resid),
                                    (iorq->buf->b_flags & B_READ));
                                biodone(iorq->buf);
                                XDC_FREE(xdcsc, lcv);   /* add to free list */
                                break;
                        case XD_SUB_WAIT:
                                wakeup(iorq);
                        case XD_SUB_POLL:
                                xdcsc->ndone++;
                                iorq->mode =
                                    XD_NEWSTATE(iorq->mode, XD_SUB_DONE);
                                break;
                        }

                } else {

                        /* resubmit, put at front of wait queue */
                        XDC_HWAIT(xdcsc, lcv);
                }
        }

        /*
         * now, if stuff is waiting, start it.
         * since we just reset it should go
         */
        xdc_start(xdcsc, XDC_MAXIOPB);

        /* ok, we did it */
        if (oldfree == 0 && xdcsc->nfree)
                wakeup(&xdcsc->nfree);

#ifdef XDC_DIAG
        del = xdcsc->nwait + xdcsc->nrun + xdcsc->nfree + xdcsc->ndone;
        if (del != XDC_MAXIOPB)
                printf("%s: diag: xdc_reset miscount (%d should be %d)!\n",
                    device_xname(xdcsc->sc_dev), del, XDC_MAXIOPB);
        else
                if (xdcsc->ndone > XDC_MAXIOPB - XDC_SUBWAITLIM)
                        printf("%s: diag: lots of done jobs (%d)\n",
                            device_xname(xdcsc->sc_dev), xdcsc->ndone);
#endif
        printf("RESET DONE\n");
        return retval;
}

/*
 * xdc_start: start all waiting buffers
 */
void 
xdc_start(struct xdc_softc *xdcsc, int maxio)
{
        int rqno;
        while (maxio && xdcsc->nwait &&
                (xdcsc->xdc->xdc_csr & XDC_ADDING) == 0) {
                XDC_GET_WAITER(xdcsc, rqno);    /* note: rqno is an "out"
                                                 * param */
                if (xdc_submit_iorq(xdcsc, rqno, XD_SUB_NOQ) != XD_ERR_AOK)
                        panic("%s", __func__);  /* should never happen */
                maxio--;
        }
}

/*
 * xdc_remove_iorq: remove "done" IOPB's.
 */
int 
xdc_remove_iorq(struct xdc_softc *xdcsc)
{
        int errno, rqno, comm, errs;
        struct xdc *xdc = xdcsc->xdc;
        struct xd_iopb *iopb;
        struct xd_iorq *iorq;
        struct buf *bp;

        if (xdc->xdc_csr & XDC_F_ERROR) {
                /*
                 * FATAL ERROR: should never happen under normal use. This
                 * error is so bad, you can't even tell which IOPB is bad, so
                 * we dump them all.
                 */
                errno = xdc->xdc_f_err;
                printf("%s: fatal error 0x%02x: %s\n",
                    device_xname(xdcsc->sc_dev), errno, xdc_e2str(errno));
                if (xdc_reset(xdcsc, 0, XD_RSET_ALL, errno, 0) != XD_ERR_AOK) {
                        printf("%s: soft reset failed!\n",
                            device_xname(xdcsc->sc_dev));
                        panic("%s: controller DEAD", __func__);
                }
                return XD_ERR_AOK;
        }

        /*
         * get iopb that is done
         *
         * hmm... I used to read the address of the done IOPB off the VME
         * registers and calculate the rqno directly from that.   that worked
         * until I started putting a load on the controller.   when loaded, i
         * would get interrupts but neither the REMIOPB or F_ERROR bits would
         * be set, even after DELAY'ing a while!   later on the timeout
         * routine would detect IOPBs that were marked "running" but their
         * "done" bit was set.   rather than dealing directly with this
         * problem, it is just easier to look at all running IOPB's for the
         * done bit.
         */
        if (xdc->xdc_csr & XDC_REMIOPB) {
                xdc->xdc_csr = XDC_CLRRIO;
        }

        for (rqno = 0; rqno < XDC_MAXIOPB; rqno++) {
                iorq = &xdcsc->reqs[rqno];
                if (iorq->mode == 0 || XD_STATE(iorq->mode) == XD_SUB_DONE)
                        continue;       /* free, or done */
                iopb = &xdcsc->iopbase[rqno];
                if (iopb->done == 0)
                        continue;       /* not done yet */

#ifdef XDC_DEBUG
                {
                        u_char *rio = (u_char *)iopb;
                        int sz = sizeof(struct xd_iopb), lcv;

                        printf("%s: rio #%d [",
                            device_xname(xdcsc->sc_dev), rqno);
                        for (lcv = 0; lcv < sz; lcv++)
                                printf(" %02x", rio[lcv]);
                        printf("]\n");
                }
#endif                          /* XDC_DEBUG */

                xdcsc->nrun--;

                comm = iopb->comm;
                errs = iopb->errs;

                if (errs)
                        iorq->errno = iopb->errno;
                else
                        iorq->errno = 0;

                /* handle non-fatal errors */

                if (errs &&
                    xdc_error(xdcsc, iorq, iopb, rqno, comm) == XD_ERR_AOK)
                        continue;       /* AOK: we resubmitted it */


                /* this iorq is now done (hasn't been restarted or anything) */

                if ((iorq->mode & XD_MODE_VERBO) && iorq->lasterror)
                        xdc_perror(iorq, iopb, 0);

                /* now, if read/write check to make sure we got all the data
                 * we needed. (this may not be the case if we got an error in
                 * the middle of a multisector request).   */

                if ((iorq->mode & XD_MODE_B144) != 0 && errs == 0 &&
                    (comm == XDCMD_RD || comm == XDCMD_WR)) {
                        /* we just successfully processed a bad144 sector
                         * note: if we are in bad 144 mode, the pointers have
                         * been advanced already (see above) and are pointing
                         * at the bad144 sector.   to exit bad144 mode, we
                         * must advance the pointers 1 sector and issue a new
                         * request if there are still sectors left to process
                         *
                         */
                        XDC_ADVANCE(iorq, 1);   /* advance 1 sector */

                        /* exit b144 mode */
                        iorq->mode = iorq->mode & (~XD_MODE_B144);

                        if (iorq->sectcnt) {    /* more to go! */
                                iorq->lasterror = iorq->errno = iopb->errno = 0;
                                iopb->errs = iopb->done = 0;
                                iorq->tries = 0;
                                iopb->sectcnt = iorq->sectcnt;
                                iopb->cylno =
                                    iorq->blockno / iorq->xd->sectpercyl;
                                iopb->headno =
                                    (iorq->blockno / iorq->xd->nhead) %
                                    iorq->xd->nhead;
                                iopb->sectno = iorq->blockno % XDFM_BPS;
                                iopb->daddr =
                                    dvma_kvtopa(iorq->dbuf, xdcsc->bustype);
                                XDC_HWAIT(xdcsc, rqno);
                                xdc_start(xdcsc, 1);    /* resubmit */
                                continue;
                        }
                }
                /* final cleanup, totally done with this request */

                switch (XD_STATE(iorq->mode)) {
                case XD_SUB_NORM:
                        bp = iorq->buf;
                        if (errs) {
                                bp->b_error = EIO;
                                bp->b_resid = iorq->sectcnt * XDFM_BPS;
                        } else {
                                bp->b_resid = 0;        /* done */
                        }
                        /* Sun3: map/unmap regardless of B_PHYS */
                        dvma_mapout(iorq->dbufbase, iorq->buf->b_bcount);
                        disk_unbusy(&iorq->xd->sc_dk,
                            (bp->b_bcount - bp->b_resid),
                            (bp->b_flags & B_READ));
                        XDC_FREE(xdcsc, rqno);
                        biodone(bp);
                        break;
                case XD_SUB_WAIT:
                        iorq->mode = XD_NEWSTATE(iorq->mode, XD_SUB_DONE);
                        xdcsc->ndone++;
                        wakeup(iorq);
                        break;
                case XD_SUB_POLL:
                        iorq->mode = XD_NEWSTATE(iorq->mode, XD_SUB_DONE);
                        xdcsc->ndone++;
                        break;
                }
        }

        return XD_ERR_AOK;
}

/*
 * xdc_perror: print error.
 * - if still_trying is true: we got an error, retried and got a
 *   different error.  in that case lasterror is the old error,
 *   and errno is the new one.
 * - if still_trying is not true, then if we ever had an error it
 *   is in lasterror. also, if iorq->errno == 0, then we recovered
 *   from that error (otherwise iorq->errno == iorq->lasterror).
 */
void 
xdc_perror(struct xd_iorq *iorq, struct xd_iopb *iopb, int still_trying)
{
        int error = iorq->lasterror;

        printf("%s", (iorq->xd) ?
            device_xname(iorq->xd->sc_dev) :
            device_xname(iorq->xdc->sc_dev));
        if (iorq->buf)
                printf("%c: ", 'a' + (char)DISKPART(iorq->buf->b_dev));
        if (iopb->comm == XDCMD_RD || iopb->comm == XDCMD_WR)
                printf("%s %d/%d/%d: ",
                    (iopb->comm == XDCMD_RD) ? "read" : "write",
                    iopb->cylno, iopb->headno, iopb->sectno);
        printf("%s", xdc_e2str(error));

        if (still_trying)
                printf(" [still trying, new error=%s]", xdc_e2str(iorq->errno));
        else
                if (iorq->errno == 0)
                        printf(" [recovered in %d tries]", iorq->tries);

        printf("\n");
}

/*
 * xdc_error: non-fatal error encountered... recover.
 * return AOK if resubmitted, return FAIL if this iopb is done
 */
int 
xdc_error(struct xdc_softc *xdcsc, struct xd_iorq *iorq, struct xd_iopb *iopb,
    int rqno, int comm)

{
        int errno = iorq->errno;
        int erract = errno & XD_ERA_MASK;
        int oldmode, advance, i;

        if (erract == XD_ERA_RSET) {    /* some errors require a reset */
                oldmode = iorq->mode;
                iorq->mode = XD_SUB_DONE | (~XD_SUB_MASK & oldmode);
                xdcsc->ndone++;
                /* make xdc_start ignore us */
                xdc_reset(xdcsc, 1, XD_RSET_NONE, errno, iorq->xd);
                iorq->mode = oldmode;
                xdcsc->ndone--;
        }
        /* check for read/write to a sector in bad144 table if bad: redirect
         * request to bad144 area */

        if ((comm == XDCMD_RD || comm == XDCMD_WR) &&
            (iorq->mode & XD_MODE_B144) == 0) {
                advance = iorq->sectcnt - iopb->sectcnt;
                XDC_ADVANCE(iorq, advance);
                if ((i = isbad(&iorq->xd->dkb,
                    iorq->blockno / iorq->xd->sectpercyl,
                    (iorq->blockno / iorq->xd->nsect) % iorq->xd->nhead,
                    iorq->blockno % iorq->xd->nsect)) != -1) {
                        iorq->mode |= XD_MODE_B144;     /* enter bad144 mode &
                                                         * redirect */
                        iopb->errno = iopb->done = iopb->errs = 0;
                        iopb->sectcnt = 1;
                        iopb->cylno = (iorq->xd->ncyl + iorq->xd->acyl) - 2;
                        /* second to last acyl */
                        i = iorq->xd->sectpercyl - 1 - i;       /* follow bad144
                                                                 * standard */
                        iopb->headno = i / iorq->xd->nhead;
                        iopb->sectno = i % iorq->xd->nhead;
                        XDC_HWAIT(xdcsc, rqno);
                        xdc_start(xdcsc, 1);    /* resubmit */
                        return XD_ERR_AOK;      /* recovered! */
                }
        }

        /*
         * it isn't a bad144 sector, must be real error! see if we can retry
         * it?
         */
        if ((iorq->mode & XD_MODE_VERBO) && iorq->lasterror)
                xdc_perror(iorq, iopb, 1);      /* inform of error state
                                                 * change */
        iorq->lasterror = errno;

        if ((erract == XD_ERA_RSET || erract == XD_ERA_HARD)
            && iorq->tries < XDC_MAXTRIES) {    /* retry? */
                iorq->tries++;
                iorq->errno = iopb->errno = iopb->done = iopb->errs = 0;
                XDC_HWAIT(xdcsc, rqno);
                xdc_start(xdcsc, 1);    /* restart */
                return XD_ERR_AOK;      /* recovered! */
        }

        /* failed to recover from this error */
        return XD_ERR_FAIL;
}

/*
 * xdc_tick: make sure xd is still alive and ticking (err, kicking).
 */
void 
xdc_tick(void *arg)
{
        struct xdc_softc *xdcsc = arg;
        int     lcv, s, reset = 0;
#ifdef XDC_DIAG
        int     nwait, nrun, nfree, ndone, whd = 0;
        uint8_t  fqc[XDC_MAXIOPB], wqc[XDC_MAXIOPB], mark[XDC_MAXIOPB];
        s = splbio();
        nwait = xdcsc->nwait;
        nrun = xdcsc->nrun;
        nfree = xdcsc->nfree;
        ndone = xdcsc->ndone;
        memcpy(wqc, xdcsc->waitq, sizeof(wqc));
        memcpy(fqc, xdcsc->freereq, sizeof(fqc));
        splx(s);
        if (nwait + nrun + nfree + ndone != XDC_MAXIOPB) {
                printf("%s: diag: IOPB miscount "
                    "(got w/f/r/d %d/%d/%d/%d, wanted %d)\n",
                    device_xname(xdcsc->sc_dev), nwait, nfree, nrun, ndone,
                    XDC_MAXIOPB);
                memset(mark, 0, sizeof(mark));
                printf("FREE: ");
                for (lcv = nfree; lcv > 0; lcv--) {
                        printf("%d ", fqc[lcv - 1]);
                        mark[fqc[lcv - 1]] = 1;
                }
                printf("\nWAIT: ");
                lcv = nwait;
                while (lcv > 0) {
                        printf("%d ", wqc[whd]);
                        mark[wqc[whd]] = 1;
                        whd = (whd + 1) % XDC_MAXIOPB;
                        lcv--;
                }
                printf("\n");
                for (lcv = 0; lcv < XDC_MAXIOPB; lcv++) {
                        if (mark[lcv] == 0) {
                                printf("MARK: running %d: mode %d done %d "
                                    "errs %d errno 0x%x ttl %d buf %p\n",
                                    lcv, xdcsc->reqs[lcv].mode,
                                    xdcsc->iopbase[lcv].done,
                                    xdcsc->iopbase[lcv].errs,
                                    xdcsc->iopbase[lcv].errno,
                                    xdcsc->reqs[lcv].ttl,
                                    xdcsc->reqs[lcv].buf);
                        }
                }
        } else
                if (ndone > XDC_MAXIOPB - XDC_SUBWAITLIM)
                        printf("%s: diag: lots of done jobs (%d)\n",
                            device_xname(xdcsc->sc_dev), ndone);

#endif
#ifdef XDC_DEBUG
        printf("%s: tick: csr 0x%x, w/f/r/d %d/%d/%d/%d\n",
            device_xname(xdcsc->sc_dev),
            xdcsc->xdc->xdc_csr, xdcsc->nwait, xdcsc->nfree, xdcsc->nrun,
            xdcsc->ndone);
        for (lcv = 0; lcv < XDC_MAXIOPB; lcv++) {
                if (xdcsc->reqs[lcv].mode) {
                        printf("running %d: "
                            "mode %d done %d errs %d errno 0x%x\n", lcv,
                            xdcsc->reqs[lcv].mode, xdcsc->iopbase[lcv].done,
                            xdcsc->iopbase[lcv].errs,
                            xdcsc->iopbase[lcv].errno);
                }
        }
#endif

        /* reduce ttl for each request if one goes to zero, reset xdc */
        s = splbio();
        for (lcv = 0; lcv < XDC_MAXIOPB; lcv++) {
                if (xdcsc->reqs[lcv].mode == 0 ||
                    XD_STATE(xdcsc->reqs[lcv].mode) == XD_SUB_DONE)
                        continue;
                xdcsc->reqs[lcv].ttl--;
                if (xdcsc->reqs[lcv].ttl == 0)
                        reset = 1;
        }
        if (reset) {
                printf("%s: watchdog timeout\n", device_xname(xdcsc->sc_dev));
                xdc_reset(xdcsc, 0, XD_RSET_NONE, XD_ERR_FAIL, NULL);
        }
        splx(s);

        /* until next time */

        callout_reset(&xdcsc->sc_tick_ch, XDC_TICKCNT, xdc_tick, xdcsc);
}

/*
 * xdc_ioctlcmd: this function provides a user level interface to the
 * controller via ioctl.   this allows "format" programs to be written
 * in user code, and is also useful for some debugging.   we return
 * an error code.   called at user priority.
 */
int 
xdc_ioctlcmd(struct xd_softc *xd, dev_t dev, struct xd_iocmd *xio)
{
        int s, err, rqno;
        void *dvmabuf = NULL;
        struct xdc_softc *xdcsc;

        /* check sanity of requested command */

        switch (xio->cmd) {

        case XDCMD_NOP: /* no op: everything should be zero */
                if (xio->subfn || xio->dptr || xio->dlen ||
                    xio->block || xio->sectcnt)
                        return EINVAL;
                break;

        case XDCMD_RD:          /* read / write sectors (up to XD_IOCMD_MAXS) */
        case XDCMD_WR:
                if (xio->subfn || xio->sectcnt > XD_IOCMD_MAXS ||
                    xio->sectcnt * XDFM_BPS != xio->dlen || xio->dptr == NULL)
                        return EINVAL;
                break;

        case XDCMD_SK:          /* seek: doesn't seem useful to export this */
                return EINVAL;

        case XDCMD_WRP: /* write parameters */
                return EINVAL;  /* not useful, except maybe drive
                                 * parameters... but drive parameters should
                                 * go via disklabel changes */

        case XDCMD_RDP: /* read parameters */
                if (xio->subfn != XDFUN_DRV ||
                    xio->dlen || xio->block || xio->dptr)
                        return EINVAL;          /* allow read drive params to
                                                 * get hw_spt */
                xio->sectcnt = xd->hw_spt;      /* we already know the answer */
                return 0;
                break;

        case XDCMD_XRD: /* extended read/write */
        case XDCMD_XWR:

                switch (xio->subfn) {

                case XDFUN_THD:/* track headers */
                        if (xio->sectcnt != xd->hw_spt ||
                            (xio->block % xd->nsect) != 0 ||
                            xio->dlen != XD_IOCMD_HSZ * xd->hw_spt ||
                            xio->dptr == NULL)
                                return EINVAL;
                        xio->sectcnt = 0;
                        break;

                case XDFUN_FMT:/* NOTE: also XDFUN_VFY */
                        if (xio->cmd == XDCMD_XRD)
                                return EINVAL;  /* no XDFUN_VFY */
                        if (xio->sectcnt || xio->dlen ||
                            (xio->block % xd->nsect) != 0 || xio->dptr)
                                return EINVAL;
                        break;

                case XDFUN_HDR:/* header, header verify, data, data ECC */
                        return EINVAL;  /* not yet */

                case XDFUN_DM:  /* defect map */
                case XDFUN_DMX:/* defect map (alternate location) */
                        if (xio->sectcnt || xio->dlen != XD_IOCMD_DMSZ ||
                            (xio->block % xd->nsect) != 0 || xio->dptr == NULL)
                                return EINVAL;
                        break;

                default:
                        return EINVAL;
                }
                break;

        case XDCMD_TST: /* diagnostics */
                return EINVAL;

        default:
                return EINVAL;/* ??? */
        }

        /* create DVMA buffer for request if needed */

        if (xio->dlen) {
                dvmabuf = dvma_malloc(xio->dlen);
                if (xio->cmd == XDCMD_WR || xio->cmd == XDCMD_XWR) {
                        err = copyin(xio->dptr, dvmabuf, xio->dlen);
                        if (err) {
                                dvma_free(dvmabuf, xio->dlen);
                                return err;
                        }
                }
        }
        /* do it! */

        err = 0;
        xdcsc = xd->parent;
        s = splbio();
        rqno = xdc_cmd(xdcsc, xio->cmd, xio->subfn, xd->xd_drive, xio->block,
            xio->sectcnt, dvmabuf, XD_SUB_WAIT);
        if (rqno == XD_ERR_FAIL) {
                err = EIO;
                goto done;
        }
        xio->errno = xdcsc->reqs[rqno].errno;
        xio->tries = xdcsc->reqs[rqno].tries;
        XDC_DONE(xdcsc, rqno, err);

        if (xio->cmd == XDCMD_RD || xio->cmd == XDCMD_XRD)
                err = copyout(dvmabuf, xio->dptr, xio->dlen);

 done:
        splx(s);
        if (dvmabuf)
                dvma_free(dvmabuf, xio->dlen);
        return err;
}

/*
 * xdc_e2str: convert error code number into an error string
 */
const char *
xdc_e2str(int no)
{

        switch (no) {
        case XD_ERR_FAIL:
                return "Software fatal error";
        case XD_ERR_AOK:
                return "Successful completion";
        case XD_ERR_ICYL:
                return "Illegal cylinder address";
        case XD_ERR_IHD:
                return "Illegal head address";
        case XD_ERR_ISEC:
                return "Illgal sector address";
        case XD_ERR_CZER:
                return "Count zero";
        case XD_ERR_UIMP:
                return "Unimplemented command";
        case XD_ERR_IF1:
                return "Illegal field length 1";
        case XD_ERR_IF2:
                return "Illegal field length 2";
        case XD_ERR_IF3:
                return "Illegal field length 3";
        case XD_ERR_IF4:
                return "Illegal field length 4";
        case XD_ERR_IF5:
                return "Illegal field length 5";
        case XD_ERR_IF6:
                return "Illegal field length 6";
        case XD_ERR_IF7:
                return "Illegal field length 7";
        case XD_ERR_ISG:
                return "Illegal scatter/gather length";
        case XD_ERR_ISPT:
                return "Not enough sectors per track";
        case XD_ERR_ALGN:
                return "Next IOPB address alignment error";
        case XD_ERR_SGAL:
                return "Scatter/gather address alignment error";
        case XD_ERR_SGEC:
                return "Scatter/gather with auto-ECC";
        case XD_ERR_SECC:
                return "Soft ECC corrected";
        case XD_ERR_SIGN:
                return "ECC ignored";
        case XD_ERR_ASEK:
                return "Auto-seek retry recovered";
        case XD_ERR_RTRY:
                return "Soft retry recovered";
        case XD_ERR_HECC:
                return "Hard data ECC";
        case XD_ERR_NHDR:
                return "Header not found";
        case XD_ERR_NRDY:
                return "Drive not ready";
        case XD_ERR_TOUT:
                return "Operation timeout";
        case XD_ERR_VTIM:
                return "VMEDMA timeout";
        case XD_ERR_DSEQ:
                return "Disk sequencer error";
        case XD_ERR_HDEC:
                return "Header ECC error";
        case XD_ERR_RVFY:
                return "Read verify";
        case XD_ERR_VFER:
                return "Fatail VMEDMA error";
        case XD_ERR_VBUS:
                return "VMEbus error";
        case XD_ERR_DFLT:
                return "Drive faulted";
        case XD_ERR_HECY:
                return "Header error/cyliner";
        case XD_ERR_HEHD:
                return "Header error/head";
        case XD_ERR_NOCY:
                return "Drive not on-cylinder";
        case XD_ERR_SEEK:
                return "Seek error";
        case XD_ERR_ILSS:
                return "Illegal sector size";
        case XD_ERR_SEC:
                return "Soft ECC";
        case XD_ERR_WPER:
                return "Write-protect error";
        case XD_ERR_IRAM:
                return "IRAM self test failure";
        case XD_ERR_MT3:
                return "Maintenance test 3 failure (DSKCEL RAM)";
        case XD_ERR_MT4:
                return "Maintenance test 4 failure (header shift reg)";
        case XD_ERR_MT5:
                return "Maintenance test 5 failure (VMEDMA regs)";
        case XD_ERR_MT6:
                return "Maintenance test 6 failure (REGCEL chip)";
        case XD_ERR_MT7:
                return "Maintenance test 7 failure (buffer parity)";
        case XD_ERR_MT8:
                return "Maintenance test 8 failure (disk FIFO)";
        case XD_ERR_IOCK:
                return "IOPB checksum miscompare";
        case XD_ERR_IODM:
                return "IOPB DMA fatal";
        case XD_ERR_IOAL:
                return "IOPB address alignment error";
        case XD_ERR_FIRM:
                return "Firmware error";
        case XD_ERR_MMOD:
                return "Illegal maintenance mode test number";
        case XD_ERR_ACFL:
                return "ACFAIL asserted";
        default:
                return "Unknown error";
        }
}