/*      $NetBSD: xy.c,v 1.105 2026/07/04 15:53:53 christos 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.
 *
 * 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 y . c   x y l o g i c s   4 5 0 / 4 5 1   s m d   d r i v e r
 *
 * author: Chuck Cranor <chuck@netbsd>
 * started: 14-Sep-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
 *             [3] Xylogics Model 450 User's Manual
 *                 part number: 166-017-001, Revision B, 1983.
 *             [4] Addendum to Xylogics Model 450 Disk Controller User's
 *                      Manual, Jan. 1985.
 *             [5] The 451 Controller, Rev. B3, September 2, 1986.
 *             [6] David Jones <dej@achilles.net>'s unfinished 450/451 driver
 *
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xy.c,v 1.105 2026/07/04 15:53:53 christos Exp $");

#undef XYC_DEBUG                /* full debug */
#undef XYC_DIAG                 /* extra sanity checks */
#if defined(DIAGNOSTIC) && !defined(XYC_DIAG)
#define XYC_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 <sys/bus.h>
#include <sys/intr.h>

#if defined(__sparc__) || defined(sun3)
#include <dev/sun/disklabel.h>
#endif

#include <dev/vme/vmereg.h>
#include <dev/vme/vmevar.h>

#include <dev/vme/xyreg.h>
#include <dev/vme/xyvar.h>
#include <dev/vme/xio.h>

#include "locators.h"

/*
 * macros
 */

/*
 * XYC_GO: start iopb ADDR (DVMA addr in a u_long) on XYC
 */
#define XYC_GO(XYC, ADDR) { \
        u_long addr = (u_long)ADDR; \
        (XYC)->xyc_addr_lo = ((addr) & 0xff); \
        (addr) = ((addr) >> 8); \
        (XYC)->xyc_addr_hi = ((addr) & 0xff); \
        (addr) = ((addr) >> 8); \
        (XYC)->xyc_reloc_lo = ((addr) & 0xff); \
        (addr) = ((addr) >> 8); \
        (XYC)->xyc_reloc_hi = (addr); \
        (XYC)->xyc_csr = XYC_GBSY; /* go! */ \
}

/*
 * XYC_DONE: don't need IORQ, get error code and free (done after xyc_cmd)
 */

#define XYC_DONE(SC,ER) { \
        if ((ER) == XY_ERR_AOK) { \
                (ER) = (SC)->ciorq->errnum; \
                (SC)->ciorq->mode = XY_SUB_FREE; \
                wakeup((SC)->ciorq); \
        } \
        }

/*
 * XYC_ADVANCE: advance iorq's pointers by a number of sectors
 */

#define XYC_ADVANCE(IORQ, N) { \
        if (N) { \
                (IORQ)->sectcnt -= (N); \
                (IORQ)->blockno += (N); \
                (IORQ)->dbuf += ((N)*XYFM_BPS); \
        } \
}

/*
 * note - addresses you can sleep on:
 *   [1] & of xy_softc's "state" (waiting for a chance to attach a drive)
 *   [2] & an iorq (waiting for an XY_SUB_WAIT iorq to finish)
 */


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

extern int pil_to_vme[];        /* from obio.c */

/* internals */
struct xy_iopb *xyc_chain(struct xyc_softc *, struct xy_iorq *);
int     xyc_cmd(struct xyc_softc *, int, int, int, int, int, char *, int);
const char *xyc_e2str(int);
int     xyc_entoact(int);
int     xyc_error(struct xyc_softc *, struct xy_iorq *,
                   struct xy_iopb *, int);
int     xyc_ioctlcmd(struct xy_softc *, dev_t dev, struct xd_iocmd *);
void    xyc_perror(struct xy_iorq *, struct xy_iopb *, int);
int     xyc_piodriver(struct xyc_softc *, struct xy_iorq *);
int     xyc_remove_iorq(struct xyc_softc *);
int     xyc_reset(struct xyc_softc *, int, struct xy_iorq *, int,
                  struct xy_softc *);
inline void xyc_rqinit(struct xy_iorq *, struct xyc_softc *,
                        struct xy_softc *, int, u_long, int,
                        void *, struct buf *);
void    xyc_rqtopb(struct xy_iorq *, struct xy_iopb *, int, int);
void    xyc_start(struct xyc_softc *, struct xy_iorq *);
int     xyc_startbuf(struct xyc_softc *, struct xy_softc *, struct buf *);
int     xyc_submit_iorq(struct xyc_softc *, struct xy_iorq *, int);
void    xyc_tick(void *);
int     xyc_unbusy(struct xyc *, int);
void    xyc_xyreset(struct xyc_softc *, struct xy_softc *);
int     xy_dmamem_alloc(bus_dma_tag_t, bus_dmamap_t, bus_dma_segment_t *,
                        int *, bus_size_t, void **, bus_addr_t *);
void    xy_dmamem_free(bus_dma_tag_t, bus_dmamap_t, bus_dma_segment_t *,
                        int, bus_size_t, void *);

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

/* autoconf */
int     xycmatch(device_t, cfdata_t, void *);
void    xycattach(device_t, device_t, void *);
int     xymatch(device_t, cfdata_t, void *);
void    xyattach(device_t, device_t, void *);
static  int xyc_probe(void *, bus_space_tag_t, bus_space_handle_t);

static  void xydummystrat(struct buf *);
int     xygetdisklabel(struct xy_softc *, void *);

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

CFATTACH_DECL_NEW(xyc, sizeof(struct xyc_softc),
    xycmatch, xycattach, NULL, NULL);

CFATTACH_DECL_NEW(xy, sizeof(struct xy_softc),
    xymatch, xyattach, NULL, NULL);

extern struct cfdriver xy_cd;

dev_type_open(xyopen);
dev_type_close(xyclose);
dev_type_read(xyread);
dev_type_write(xywrite);
dev_type_ioctl(xyioctl);
dev_type_strategy(xystrategy);
dev_type_dump(xydump);
dev_type_size(xysize);

const struct bdevsw xy_bdevsw = {
        .d_open = xyopen,
        .d_close = xyclose,
        .d_strategy = xystrategy,
        .d_ioctl = xyioctl,
        .d_dump = xydump,
        .d_psize = xysize,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

const struct cdevsw xy_cdevsw = {
        .d_open = xyopen,
        .d_close = xyclose,
        .d_read = xyread,
        .d_write = xywrite,
        .d_ioctl = xyioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

struct xyc_attach_args {        /* this is the "aux" args to xyattach */
        int     driveno;        /* unit number */
        int     fullmode;       /* submit mode */
        int     booting;        /* are we booting or not? */
};

/*
 * dkdriver
 */

struct dkdriver xydkdriver = {
        .d_strategy = xystrategy
};

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

static void *xy_labeldata;

static void
xydummystrat(struct buf *bp)
{
        if (bp->b_bcount != XYFM_BPS)
                panic("xydummystrat");
        memcpy(bp->b_data, xy_labeldata, XYFM_BPS);
        bp->b_oflags |= BO_DONE;
        bp->b_cflags &= ~BC_BUSY;
}

int
xygetdisklabel(struct xy_softc *xy, void *b)
{
        const char *err;
#if defined(__sparc__) || defined(sun3)
        struct sun_disklabel *sdl;
#endif

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

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

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

#if defined(__sparc__) || defined(sun3)
        /* Ok, we have the label; fill in `pcyl' if there's SunOS magic */
        sdl = (struct sun_disklabel *)xy->sc_dk.dk_cpulabel->cd_block;
        if (sdl->sl_magic == SUN_DKMAGIC) {
                xy->pcyl = sdl->sl_pcylinders;
        } else
#endif
        {
                printf("%s: WARNING: no `pcyl' in disk label.\n",
                        device_xname(xy->sc_dev));
                xy->pcyl = xy->sc_dk.dk_label->d_ncylinders +
                        xy->sc_dk.dk_label->d_acylinders;
                printf("%s: WARNING: guessing pcyl=%d (ncyl+acyl)\n",
                        device_xname(xy->sc_dev), xy->pcyl);
        }

        xy->ncyl = xy->sc_dk.dk_label->d_ncylinders;
        xy->acyl = xy->sc_dk.dk_label->d_acylinders;
        xy->nhead = xy->sc_dk.dk_label->d_ntracks;
        xy->nsect = xy->sc_dk.dk_label->d_nsectors;
        xy->sectpercyl = xy->nhead * xy->nsect;
        xy->sc_dk.dk_label->d_secsize = XYFM_BPS; /* not handled by
                                                  * sun->bsd */
        return(XY_ERR_AOK);
}

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

/*
 * Shorthand for allocating, mapping and loading a DMA buffer
 */
int
xy_dmamem_alloc(bus_dma_tag_t tag, bus_dmamap_t map, bus_dma_segment_t *seg, int *nsegp, bus_size_t len, void * *kvap, bus_addr_t *dmap)
{
        int nseg;
        int error;

        if ((error = bus_dmamem_alloc(tag, len, 0, 0,
                                      seg, 1, &nseg, BUS_DMA_NOWAIT)) != 0) {
                return (error);
        }

        if ((error = bus_dmamem_map(tag, seg, nseg,
                                    len, kvap,
                                    BUS_DMA_NOWAIT|BUS_DMA_COHERENT)) != 0) {
                bus_dmamem_free(tag, seg, nseg);
                return (error);
        }

        if ((error = bus_dmamap_load(tag, map, *kvap, len, NULL,
                                     BUS_DMA_NOWAIT)) != 0) {
                bus_dmamem_unmap(tag, *kvap, len);
                bus_dmamem_free(tag, seg, nseg);
                return (error);
        }

        *dmap = map->dm_segs[0].ds_addr;
        *nsegp = nseg;
        return (0);
}

void
xy_dmamem_free(bus_dma_tag_t tag, bus_dmamap_t map, bus_dma_segment_t *seg, int nseg, bus_size_t len, void * kva)
{

        bus_dmamap_unload(tag, map);
        bus_dmamem_unmap(tag, kva, len);
        bus_dmamem_free(tag, seg, nseg);
}


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

/*
 * xycmatch: determine if xyc is present or not.   we do a
 * soft reset to detect the xyc.
 */
int
xyc_probe(void *arg, bus_space_tag_t tag, bus_space_handle_t handle)
{
        struct xyc *xyc = (void *)handle; /* XXX */

        return ((xyc_unbusy(xyc, XYC_RESETUSEC) != XY_ERR_FAIL) ? 0 : EIO);
}

int
xycmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct vme_attach_args  *va = aux;
        vme_chipset_tag_t       ct = va->va_vct;
        vme_am_t                mod;
        int error;

        mod = VME_AM_A16 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;
        if (vme_space_alloc(ct, va->r[0].offset, sizeof(struct xyc), mod))
                return (0);

        error = vme_probe(ct, va->r[0].offset, sizeof(struct xyc),
                          mod, VME_D16, xyc_probe, 0);
        vme_space_free(va->va_vct, va->r[0].offset, sizeof(struct xyc), mod);

        return (error == 0);
}

/*
 * xycattach: attach controller
 */
void
xycattach(device_t parent, device_t self, void *aux)
{
        struct xyc_softc        *xyc = device_private(self);
        struct vme_attach_args  *va = aux;
        vme_chipset_tag_t       ct = va->va_vct;
        bus_space_tag_t         bt;
        bus_space_handle_t      bh;
        vme_intr_handle_t       ih;
        vme_am_t                mod;
        struct xyc_attach_args  xa;
        int                     lcv, res, error;
        bus_dma_segment_t       seg;
        int                     rseg;
        vme_mapresc_t resc;
        bus_addr_t              busaddr;

        xyc->sc_dev = self;

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

        mod = VME_AM_A16 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;

        if (vme_space_alloc(ct, va->r[0].offset, sizeof(struct xyc), mod))
                panic("xyc: vme alloc");

        if (vme_space_map(ct, va->r[0].offset, sizeof(struct xyc),
                          mod, VME_D16, 0, &bt, &bh, &resc) != 0)
                panic("xyc: vme_map");

        xyc->xyc = (struct xyc *) bh; /* XXX */
        xyc->ipl = va->ilevel;
        xyc->vector = va->ivector;
        xyc->no_ols = 0; /* XXX should be from config */

        for (lcv = 0; lcv < XYC_MAXDEV; lcv++)
                xyc->sc_drives[lcv] = NULL;

        /*
         * allocate and zero buffers
         * check boundaries of the KVA's ... all IOPBs must reside in
         * the same 64K region.
         */

        /* Get DMA handle for misc. transfers */
        if ((error = vme_dmamap_create(
                                ct,             /* VME chip tag */
                                MAXPHYS,        /* size */
                                VME_AM_A24,     /* address modifier */
                                VME_D16,        /* data size */
                                0,              /* swap */
                                1,              /* nsegments */
                                MAXPHYS,        /* maxsegsz */
                                0,              /* boundary */
                                BUS_DMA_NOWAIT,
                                &xyc->auxmap)) != 0) {

                aprint_error_dev(xyc->sc_dev, "DMA buffer map create error %d\n",
                        error);
                return;
        }

        /* Get DMA handle for mapping iorq descriptors */
        if ((error = vme_dmamap_create(
                                ct,             /* VME chip tag */
                                XYC_MAXIOPB * sizeof(struct xy_iopb),
                                VME_AM_A24,     /* address modifier */
                                VME_D16,        /* data size */
                                0,              /* swap */
                                1,              /* nsegments */
                                XYC_MAXIOPB * sizeof(struct xy_iopb),
                                64*1024,        /* boundary */
                                BUS_DMA_NOWAIT,
                                &xyc->iopmap)) != 0) {

                aprint_error_dev(xyc->sc_dev, "DMA buffer map create error %d\n",
                        error);
                return;
        }

        /* Get DMA buffer for iorq descriptors */
        if ((error = xy_dmamem_alloc(xyc->dmatag, xyc->iopmap, &seg, &rseg,
                                     XYC_MAXIOPB * sizeof(struct xy_iopb),
                                     (void **)&xyc->iopbase,
                                     &busaddr)) != 0) {
                aprint_error_dev(xyc->sc_dev, "DMA buffer alloc error %d\n",
                        error);
                return;
        }
        xyc->dvmaiopb = (struct xy_iopb *)(u_long)BUS_ADDR_PADDR(busaddr);

        memset(xyc->iopbase, 0, XYC_MAXIOPB * sizeof(struct xy_iopb));

        xyc->reqs = malloc(XYC_MAXIOPB * sizeof(struct xy_iorq),
            M_DEVBUF, M_WAITOK|M_ZERO);

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

        for (lcv = 0; lcv < XYC_MAXIOPB; lcv++) {
                xyc->xy_chain[lcv] = NULL;
                xyc->reqs[lcv].iopb = &xyc->iopbase[lcv];
                xyc->reqs[lcv].dmaiopb = &xyc->dvmaiopb[lcv];
                xyc->iopbase[lcv].asr = 1;      /* always the same */
                xyc->iopbase[lcv].eef = 1;      /* always the same */
                xyc->iopbase[lcv].ecm = XY_ECM; /* always the same */
                xyc->iopbase[lcv].aud = 1;      /* always the same */
                xyc->iopbase[lcv].relo = 1;     /* always the same */
                xyc->iopbase[lcv].thro = XY_THRO;/* always the same */

                if ((error = vme_dmamap_create(
                                ct,             /* VME chip tag */
                                MAXPHYS,        /* size */
                                VME_AM_A24,     /* address modifier */
                                VME_D16,        /* data size */
                                0,              /* swap */
                                1,              /* nsegments */
                                MAXPHYS,        /* maxsegsz */
                                0,              /* boundary */
                                BUS_DMA_NOWAIT,
                                &xyc->reqs[lcv].dmamap)) != 0) {

                        aprint_error_dev(xyc->sc_dev, "DMA buffer map create error %d\n",
                                error);
                        return;
                }
        }
        xyc->ciorq = &xyc->reqs[XYC_CTLIOPB];    /* short hand name */
        xyc->ciopb = &xyc->iopbase[XYC_CTLIOPB]; /* short hand name */
        xyc->xy_hand = 0;

        /* read controller parameters and insure we have a 450/451 */

        error = xyc_cmd(xyc, XYCMD_ST, 0, 0, 0, 0, 0, XY_SUB_POLL);
        res = xyc->ciopb->ctyp;
        XYC_DONE(xyc, error);
        if (res != XYCT_450) {
                if (error)
                        printf(": %s: ", xyc_e2str(error));
                printf(": doesn't identify as a 450/451\n");
                return;
        }
        printf(": Xylogics 450/451");
        if (xyc->no_ols)
                printf(" [OLS disabled]"); /* 450 doesn't overlap seek right */
        printf("\n");
        if (error) {
                aprint_error_dev(xyc->sc_dev, "error: %s\n",
                                xyc_e2str(error));
                return;
        }
        if ((xyc->xyc->xyc_csr & XYC_ADRM) == 0) {
                printf("%s: 24 bit addressing turned off\n",
                        device_xname(xyc->sc_dev));
                printf("please set hardware jumpers JM1-JM2=in, JM3-JM4=out\n");
                printf("to enable 24 bit mode and this driver\n");
                return;
        }

        /* link in interrupt with higher level software */
        vme_intr_map(ct, va->ilevel, va->ivector, &ih);
        vme_intr_establish(ct, ih, IPL_BIO, xycintr, xyc);
        evcnt_attach_dynamic(&xyc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
            device_xname(xyc->sc_dev), "intr");

        callout_init(&xyc->sc_tick_ch, 0);

        /* now we must look for disks using autoconfig */
        xa.fullmode = XY_SUB_POLL;
        xa.booting = 1;

        for (xa.driveno = 0; xa.driveno < XYC_MAXDEV; xa.driveno++)
                (void) config_found(self, (void *) &xa, NULL, CFARGS_NONE);

        /* start the watchdog clock */
        callout_reset(&xyc->sc_tick_ch, XYC_TICKCNT, xyc_tick, xyc);

}

/*
 * xymatch: 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 xyattach!).
 */
int
xymatch(device_t parent, cfdata_t cf, void *aux)
{
        struct xyc_attach_args *xa = aux;

        /* looking for autoconf wildcard or exact match */

        if (cf->cf_loc[XYCCF_DRIVE] != XYCCF_DRIVE_DEFAULT &&
            cf->cf_loc[XYCCF_DRIVE] != xa->driveno)
                return 0;

        return 1;

}

/*
 * xyattach: attach a disk.   this can be called from autoconf and also
 * from xyopen/xystrategy.
 */
void
xyattach(device_t parent, device_t self, void *aux)
{
        struct xy_softc *xy = device_private(self), *oxy;
        struct xyc_softc *xyc = device_private(parent);
        struct xyc_attach_args *xa = aux;
        int     spt, mb, blk, lcv, fmode, s = 0, newstate;
        int                     rseg, error;
        bus_dma_segment_t       seg;
        bus_addr_t              busaddr;
        void *                  dmaddr;
        char *                  buf;

        xy->sc_dev = self;

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

        /* if booting, init the xy_softc */

        if (xa->booting) {
                xy->state = XY_DRIVE_UNKNOWN;   /* to start */
                xy->flags = 0;
                xy->parent = xyc;

                /* init queue of waiting bufs */

                bufq_alloc(&xy->xyq, "disksort", BUFQ_SORT_RAWBLOCK);

                xy->xyrq = &xyc->reqs[xa->driveno];

        }
        xy->xy_drive = xa->driveno;
        fmode = xa->fullmode;
        xyc->sc_drives[xa->driveno] = xy;

        /* if not booting, make sure we are the only process in the attach for
         * this drive.   if locked out, sleep on it. */

        if (!xa->booting) {
                s = splbio();
                while (xy->state == XY_DRIVE_ATTACHING) {
                        if (tsleep(&xy->state, PRIBIO, "xyattach", 0)) {
                                splx(s);
                                return;
                        }
                }
                printf("%s at %s",
                        device_xname(xy->sc_dev), device_xname(xy->parent->sc_dev));
        }

        /* we now have control */
        xy->state = XY_DRIVE_ATTACHING;
        newstate = XY_DRIVE_UNKNOWN;

        buf = NULL;
        if ((error = xy_dmamem_alloc(xyc->dmatag, xyc->auxmap, &seg, &rseg,
                                     XYFM_BPS,
                                     (void **)&buf,
                                     &busaddr)) != 0) {
                aprint_error_dev(xyc->sc_dev, "DMA buffer alloc error %d\n",
                        error);
                return;
        }
        dmaddr = (void *)(u_long)BUS_ADDR_PADDR(busaddr);

        /* first try and reset the drive */
        error = xyc_cmd(xyc, XYCMD_RST, 0, xy->xy_drive, 0, 0, 0, fmode);
        XYC_DONE(xyc, error);
        if (error == XY_ERR_DNRY) {
                printf(" drive %d: off-line\n", xa->driveno);
                goto done;
        }
        if (error) {
                printf(": ERROR 0x%02x (%s)\n", error, xyc_e2str(error));
                goto done;
        }
        printf(" drive %d: ready", xa->driveno);

        /*
         * now set drive parameters (to semi-bogus values) so we can read the
         * disk label.
         */
        xy->pcyl = xy->ncyl = 1;
        xy->acyl = 0;
        xy->nhead = 1;
        xy->nsect = 1;
        xy->sectpercyl = 1;

        /* read disk label */
        for (xy->drive_type = 0 ; xy->drive_type <= XYC_MAXDT ;
                                                xy->drive_type++) {
                error = xyc_cmd(xyc, XYCMD_RD, 0, xy->xy_drive, 0, 1,
                                                dmaddr, fmode);
                XYC_DONE(xyc, error);
                if (error == XY_ERR_AOK) break;
        }

        if (error != XY_ERR_AOK) {
                aprint_normal("\n");
                aprint_error_dev(xy->sc_dev, "reading disk label failed: %s\n",
                        xyc_e2str(error));
                goto done;
        }
        printf(" (drive type %d)\n", xy->drive_type);

        newstate = XY_DRIVE_NOLABEL;

        xy->hw_spt = spt = 0; /* XXX needed ? */
        /* Attach the disk: must be before getdisklabel to malloc label */
        disk_init(&xy->sc_dk, device_xname(xy->sc_dev), &xydkdriver);
        disk_attach(&xy->sc_dk);

        if (xygetdisklabel(xy, buf) != XY_ERR_AOK)
                goto done;

        /* inform the user of what is up */
        printf("%s: <%s>, pcyl %d\n", device_xname(xy->sc_dev),
                buf, xy->pcyl);
        mb = xy->ncyl * (xy->nhead * xy->nsect) / (1048576 / XYFM_BPS);
        printf("%s: %dMB, %d cyl, %d head, %d sec, %d bytes/sec\n",
                device_xname(xy->sc_dev), mb, xy->ncyl, xy->nhead, xy->nsect,
                XYFM_BPS);

        /*
         * 450/451 stupidity: the drive type is encoded into the format
         * of the disk.   the drive type in the IOPB must match the drive
         * type in the format, or you will not be able to do I/O to the
         * disk (you get header not found errors).  if you have two drives
         * of different sizes that have the same drive type in their
         * formatting then you are out of luck.
         *
         * this problem was corrected in the 753/7053.
         */

        for (lcv = 0 ; lcv < XYC_MAXDEV ; lcv++) {
                oxy = xyc->sc_drives[lcv];
                if (oxy == NULL || oxy == xy) continue;
                if (oxy->drive_type != xy->drive_type) continue;
                if (xy->nsect != oxy->nsect || xy->pcyl != oxy->pcyl ||
                        xy->nhead != oxy->nhead) {
                        printf("%s: %s and %s must be the same size!\n",
                                device_xname(xyc->sc_dev), device_xname(xy->sc_dev),
                                device_xname(oxy->sc_dev));
                        panic("xy drive size mismatch");
                }
        }


        /* now set the real drive parameters! */

        blk = (xy->nsect - 1) +
                ((xy->nhead - 1) * xy->nsect) +
                ((xy->pcyl - 1) * xy->nsect * xy->nhead);
        error = xyc_cmd(xyc, XYCMD_SDS, 0, xy->xy_drive, blk, 0, 0, fmode);
        XYC_DONE(xyc, error);
        if (error) {
                aprint_error_dev(xy->sc_dev, "write drive size failed: %s\n",
                        xyc_e2str(error));
                goto done;
        }
        newstate = XY_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).
         */

        xy->bad144 = bad144_init(XYFM_BPS, xy->ncyl, xy->nhead, xy->nsect);
        KASSERT(xy->bad144 != NULL);

        blk = (xy->ncyl + xy->acyl - 1) * (xy->nhead * xy->nsect) +
                                                                /* last cyl */
            (xy->nhead - 1) * xy->nsect;        /* last head */
        error = xyc_cmd(xyc, XYCMD_RD, 0, xy->xy_drive, blk, 1,
                                                dmaddr, fmode);
        XYC_DONE(xyc, error);
        if (error) {
                aprint_error_dev(xy->sc_dev, "reading bad144 failed: %s\n",
                        xyc_e2str(error));
                goto done;
        }

        error = bad144_set(xy->bad144, (struct dkbad *)buf);
        if (error) {
                aprint_error_dev(xy->sc_dev, "warning: invalid bad144 sector!\n");
        }

done:
        if (buf != NULL) {
                xy_dmamem_free(xyc->dmatag, xyc->auxmap,
                                &seg, rseg, XYFM_BPS, buf);
        }

        xy->state = newstate;
        if (!xa->booting) {
                wakeup(&xy->state);
                splx(s);
        }
}

/*
 * end of autoconfig functions
 */

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

/*
 * xyclose: close device
 */
int
xyclose(dev_t dev, int flag, int fmt, struct lwp *l)
{
        struct xy_softc *xy = device_lookup_private(&xy_cd, DISKUNIT(dev));
        int     part = DISKPART(dev);

        /* clear mask bits */

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

        return 0;
}

/*
 * xydump: crash dump system
 */
int
xydump(dev_t dev, daddr_t blkno, void *va, size_t size)
{
        int     unit, part;
        struct xy_softc *xy;

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

        xy = device_lookup_private(&xy_cd, unit);
        if (!xy)
                return ENXIO;

        printf("%s%c: crash dump not supported (yet)\n", device_xname(xy->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
xy_getkauthreq(u_char cmd)
{
        enum kauth_device_req req;

        switch (cmd) {
        case XYCMD_WR:
        case XYCMD_WTH:
        case XYCMD_WFM:
        case XYCMD_WRH:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITE;
                break;

        case XYCMD_RD:
        case XYCMD_RTH:
        case XYCMD_RDH:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READ;
                break;

        case XYCMD_RDS:
        case XYCMD_MBD:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF;
                break;

        case XYCMD_RST:
        case XYCMD_SDS:
        case XYCMD_MBL:
                req = KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF;
                break;

        case XYCMD_NOP:
        case XYCMD_SK:
        case XYCMD_ST:
        case XYCMD_R:
        default:
                req = 0;
                break;
        }

        return (req);
}

/*
 * xyioctl: ioctls on XY drives.   based on ioctl's of other netbsd disks.
 */
int
xyioctl(dev_t dev, u_long command, void *addr, int flag, struct lwp *l)
{
        struct xy_softc *xy;
        struct xd_iocmd *xio;
        int     error, s, unit;
#ifdef __HAVE_OLD_DISKLABEL
        struct disklabel newlabel;
#endif
        struct disklabel *lp;

        unit = DISKUNIT(dev);

        if ((xy = device_lookup_private(&xy_cd, unit)) == NULL)
                return (ENXIO);

        error = disk_ioctl(&xy->sc_dk, dev, command, addr, flag, l);
        if (error != EPASSTHROUGH)
                return error;

        /* switch on ioctl type */

        switch (command) {
        case DIOCSBAD:          /* set bad144 info */
                if ((flag & FWRITE) == 0)
                        return EBADF;
                s = splbio();
                error = bad144_set(xy->bad144, (struct dkbad *)addr);
                splx(s);
                return 0;

        case DIOCSDINFO:        /* set disk label */
#ifdef __HAVE_OLD_DISKLABEL
        case ODIOCSDINFO:
                if (command == ODIOCSDINFO) {
                        memset(&newlabel, 0, sizeof newlabel);
                        memcpy(&newlabel, addr, sizeof (struct olddisklabel));
                        lp = &newlabel;
                } else
#endif
                lp = (struct disklabel *)addr;

                if ((flag & FWRITE) == 0)
                        return EBADF;
                error = setdisklabel(xy->sc_dk.dk_label,
                    lp, /* xy->sc_dk.dk_openmask : */ 0,
                    xy->sc_dk.dk_cpulabel);
                if (error == 0) {
                        if (xy->state == XY_DRIVE_NOLABEL)
                                xy->state = XY_DRIVE_ONLINE;
                }
                return error;

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

        case DIOCWDINFO:        /* write disk label */
#ifdef __HAVE_OLD_DISKLABEL
        case ODIOCWDINFO:
                if (command == ODIOCWDINFO) {
                        memset(&newlabel, 0, sizeof newlabel);
                        memcpy(&newlabel, addr, sizeof (struct olddisklabel));
                        lp = &newlabel;
                } else
#endif
                lp = (struct disklabel *)addr;

                if ((flag & FWRITE) == 0)
                        return EBADF;
                error = setdisklabel(xy->sc_dk.dk_label,
                    lp, /* xy->sc_dk.dk_openmask : */ 0,
                    xy->sc_dk.dk_cpulabel);
                if (error == 0) {
                        if (xy->state == XY_DRIVE_NOLABEL)
                                xy->state = XY_DRIVE_ONLINE;

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

        case DIOSXDCMD: {
                enum kauth_device_req req;

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

        default:
                return ENOTTY;
        }
}

/*
 * xyopen: open drive
 */

int
xyopen(dev_t dev, int flag, int fmt, struct lwp *l)
{
        int     unit, part;
        struct xy_softc *xy;
        struct xyc_attach_args xa;

        /* first, could it be a valid target? */

        unit = DISKUNIT(dev);
        if ((xy = device_lookup_private(&xy_cd, unit)) == NULL)
                return (ENXIO);
        part = DISKPART(dev);

        /* do we need to attach the drive? */

        if (xy->state == XY_DRIVE_UNKNOWN) {
                xa.driveno = xy->xy_drive;
                xa.fullmode = XY_SUB_WAIT;
                xa.booting = 0;
                xyattach(xy->parent->sc_dev, xy->sc_dev, &xa);
                if (xy->state == XY_DRIVE_UNKNOWN) {
                        return (EIO);
                }
        }
        /* check for partition */

        if (part != RAW_PART &&
            (part >= xy->sc_dk.dk_label->d_npartitions ||
                xy->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
                return (ENXIO);
        }
        /* set open masks */

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

        return 0;
}

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

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

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

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


/*
 * xysize: return size of a partition for a dump
 */

int
xysize(dev_t dev)
{
        struct xy_softc *xysc;
        int     unit, part, size, omask;

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

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

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

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

/*
 * xystrategy: buffering system interface to xy.
 */

void
xystrategy(struct buf *bp)
{
        struct xy_softc *xy;
        int     s, unit;
        struct xyc_attach_args xa;
        struct disklabel *lp;
        daddr_t blkno;

        unit = DISKUNIT(bp->b_dev);

        /* check for live device */

        if (!(xy = device_lookup_private(&xy_cd, unit)) ||
            bp->b_blkno < 0 ||
            (bp->b_bcount % xy->sc_dk.dk_label->d_secsize) != 0) {
                bp->b_error = EINVAL;
                goto done;
        }
        /* do we need to attach the drive? */

        if (xy->state == XY_DRIVE_UNKNOWN) {
                xa.driveno = xy->xy_drive;
                xa.fullmode = XY_SUB_WAIT;
                xa.booting = 0;
                xyattach(xy->parent->sc_dev, xy->sc_dev, &xa);
                if (xy->state == XY_DRIVE_UNKNOWN) {
                        bp->b_error = EIO;
                        goto done;
                }
        }
        if (xy->state != XY_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. */

        lp = xy->sc_dk.dk_label;

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

        /*
         * Now convert the block number to absolute and put it in
         * terms of the device's logical block size.
         */
        blkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
        if (DISKPART(bp->b_dev) != RAW_PART)
                blkno += lp->d_partitions[DISKPART(bp->b_dev)].p_offset;

        bp->b_rawblkno = blkno;

        /*
         * now we know we have a valid buf structure that we need to do I/O
         * on.
         */
        s = splbio();           /* protect the queues */

        bufq_put(xy->xyq, bp);

        /* start 'em up */

        xyc_start(xy->parent, NULL);

        /* 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
 *
 * xycintr: hardware interrupt.
 */
int
xycintr(void *v)
{
        struct xyc_softc *xycsc = v;

        /* kick the event counter */

        xycsc->sc_intrcnt.ev_count++;

        /* remove as many done IOPBs as possible */

        xyc_remove_iorq(xycsc);

        /* start any iorq's already waiting */

        xyc_start(xycsc, NULL);

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

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

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

inline void
xyc_rqinit(struct xy_iorq *rq, struct xyc_softc *xyc, struct xy_softc *xy, int md, u_long blk, int cnt, void *db, struct buf *bp)
{
        rq->xyc = xyc;
        rq->xy = xy;
        rq->ttl = XYC_MAXTTL + 10;
        rq->mode = md;
        rq->tries = rq->errnum = rq->lasterror = 0;
        rq->blockno = blk;
        rq->sectcnt = cnt;
        rq->dbuf = db;
        rq->buf = bp;
}

/*
 * xyc_rqtopb: load up an IOPB based on an iorq
 */

void
xyc_rqtopb(struct xy_iorq *iorq, struct xy_iopb *iopb, int cmd, int subfun)
{
        u_long  block, dp;

        /* normal IOPB case, standard stuff */

        /* chain bit handled later */
        iopb->ien = (XY_STATE(iorq->mode) == XY_SUB_POLL) ? 0 : 1;
        iopb->com = cmd;
        iopb->errnum = 0;
        iopb->errs = 0;
        iopb->done = 0;
        if (iorq->xy) {
                iopb->unit = iorq->xy->xy_drive;
                iopb->dt = iorq->xy->drive_type;
        } else {
                iopb->unit = 0;
                iopb->dt = 0;
        }
        block = iorq->blockno;
        if (iorq->xy == NULL || block == 0) {
                iopb->sect = iopb->head = iopb->cyl = 0;
        } else {
                iopb->sect = block % iorq->xy->nsect;
                block = block / iorq->xy->nsect;
                iopb->head = block % iorq->xy->nhead;
                block = block / iorq->xy->nhead;
                iopb->cyl = block;
        }
        iopb->scnt = iorq->sectcnt;
        dp = (u_long) iorq->dbuf;
        if (iorq->dbuf == NULL) {
                iopb->dataa = 0;
                iopb->datar = 0;
        } else {
                iopb->dataa = (dp & 0xffff);
                iopb->datar = ((dp & 0xff0000) >> 16);
        }
        iopb->subfn = subfun;
}


/*
 * xyc_unbusy: wait for the xyc to go unbusy, or timeout.
 */

int
xyc_unbusy(struct xyc *xyc, int del)
{
        while (del-- > 0) {
                if ((xyc->xyc_csr & XYC_GBSY) == 0)
                        break;
                DELAY(1);
        }
        return(del == 0 ? XY_ERR_FAIL : XY_ERR_AOK);
}

/*
 * xyc_cmd: front end for POLL'd and WAIT'd commands.  Returns 0 or error.
 * note that NORM requests are handled separately.
 */
int
xyc_cmd(struct xyc_softc *xycsc, int cmd, int subfn, int unit, int block,
        int scnt, char *dptr, int fullmode)
{
        int     submode = XY_STATE(fullmode);
        struct xy_iorq *iorq = xycsc->ciorq;
        struct xy_iopb *iopb = xycsc->ciopb;

        /*
         * is someone else using the control iopq wait for it if we can
         */
start:
        if (submode == XY_SUB_WAIT && XY_STATE(iorq->mode) != XY_SUB_FREE) {
                if (tsleep(iorq, PRIBIO, "xyc_cmd", 0))
                                return(XY_ERR_FAIL);
                goto start;
        }

        if (XY_STATE(iorq->mode) != XY_SUB_FREE) {
                DELAY(1000000);         /* XY_SUB_POLL: steal the iorq */
                iorq->mode = XY_SUB_FREE;
                printf("%s: stole control iopb\n", device_xname(xycsc->sc_dev));
        }

        /* init iorq/iopb */

        xyc_rqinit(iorq, xycsc,
            (unit == XYC_NOUNIT) ? NULL : xycsc->sc_drives[unit],
            fullmode, block, scnt, dptr, NULL);

        /* load IOPB from iorq */

        xyc_rqtopb(iorq, iopb, cmd, subfn);

        /* submit it for processing */

        xyc_submit_iorq(xycsc, iorq, fullmode); /* error code will be in iorq */

        return(XY_ERR_AOK);
}

/*
 * xyc_startbuf
 * start a buffer for running
 */

int
xyc_startbuf(struct xyc_softc *xycsc, struct xy_softc *xysc, struct buf *bp)
{
#ifdef XYC_DEBUG
        int     partno;
#endif
        int     error;
        struct xy_iorq *iorq;
        struct xy_iopb *iopb;
        u_long  block;

        iorq = xysc->xyrq;
        iopb = iorq->iopb;

        /* get buf */

        if (bp == NULL)
                panic("xyc_startbuf null buf");

#ifdef XYC_DEBUG
        partno = DISKPART(bp->b_dev);
        printf("xyc_startbuf: %s%c: %s block %d\n", device_xname(xysc->sc_dev),
            'a' + partno, (bp->b_flags & B_READ) ? "read" : "write", bp->b_blkno);
        printf("xyc_startbuf: b_bcount %d, b_data 0x%x\n",
            bp->b_bcount, bp->b_data);
#endif

        /*
         * load request.
         *
         * note that iorq points to the buffer as mapped into DVMA space,
         * where as the bp->b_data points to its non-DVMA mapping.
         */

        block = bp->b_rawblkno;

        error = bus_dmamap_load(xycsc->dmatag, iorq->dmamap,
                        bp->b_data, bp->b_bcount, 0, BUS_DMA_NOWAIT);
        if (error != 0) {
                aprint_error_dev(xycsc->sc_dev, "warning: cannot load DMA map\n");
                return (XY_ERR_FAIL);   /* XXX: need some sort of
                                         * call-back scheme here? */
        }

        bus_dmamap_sync(xycsc->dmatag, iorq->dmamap, 0,
                        iorq->dmamap->dm_mapsize, (bp->b_flags & B_READ)
                                ? BUS_DMASYNC_PREREAD
                                : BUS_DMASYNC_PREWRITE);

        /* init iorq and load iopb from it */
        xyc_rqinit(iorq, xycsc, xysc, XY_SUB_NORM | XY_MODE_VERBO, block,
                   bp->b_bcount / XYFM_BPS,
                   (void *)(u_long)iorq->dmamap->dm_segs[0].ds_addr,
                   bp);

        xyc_rqtopb(iorq, iopb, (bp->b_flags & B_READ) ? XYCMD_RD : XYCMD_WR, 0);

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

        return (XY_ERR_AOK);
}


/*
 * xyc_submit_iorq: submit an iorq for processing.  returns XY_ERR_AOK
 * if ok.  if it fail returns an error code.  type is XY_SUB_*.
 *
 * note: caller frees iorq in all cases except NORM
 *
 * return value:
 *   NORM: XY_AOK (req pending), XY_FAIL (couldn't submit request)
 *   WAIT: XY_AOK (success), <error-code> (failed)
 *   POLL: <same as WAIT>
 *   NOQ : <same as NORM>
 *
 * there are three sources for i/o requests:
 * [1] xystrategy: 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 450 handles one iopb at a
 * time, where as a 451 can take them in chains.  [the 450 claims it
 * can handle chains, but is appears to be buggy...]   iopb are allocated
 * in DVMA space at boot up time.  each disk gets one iopb, and the
 * controller gets one (for POLL and WAIT commands).  what happens if
 * the iopb is busy?  for i/o type [1], the buffers are queued at the
 * "buff" layer and * picked up later by the interrupt routine.  for case
 * [2] we can only be blocked if there is a WAIT type I/O request being
 * run.   since this can only happen when we are crashing, we wait a sec
 * and then steal the IOPB.  for case [3] the process can sleep
 * on the iorq free list until some iopbs are available.
 */


int
xyc_submit_iorq(struct xyc_softc *xycsc, struct xy_iorq *iorq, int type)
{
        struct xy_iopb *dmaiopb;

#ifdef XYC_DEBUG
        printf("xyc_submit_iorq(%s, addr=0x%x, type=%d)\n",
                device_xname(xycsc->sc_dev), iorq, type);
#endif

        /* first check and see if controller is busy */
        if ((xycsc->xyc->xyc_csr & XYC_GBSY) != 0) {
#ifdef XYC_DEBUG
                printf("xyc_submit_iorq: XYC not ready (BUSY)\n");
#endif
                if (type == XY_SUB_NOQ)
                        return (XY_ERR_FAIL);   /* failed */
                switch (type) {
                case XY_SUB_NORM:
                        return XY_ERR_AOK;      /* success */
                case XY_SUB_WAIT:
                        while (iorq->iopb->done == 0) {
                                (void) tsleep(iorq, PRIBIO, "xyciorq", 0);
                        }
                        return (iorq->errnum);
                case XY_SUB_POLL:               /* steal controller */
                        (void)xycsc->xyc->xyc_rsetup; /* RESET */
                        if (xyc_unbusy(xycsc->xyc,XYC_RESETUSEC) == XY_ERR_FAIL)
                                panic("xyc_submit_iorq: stuck xyc");
                        printf("%s: stole controller\n",
                                device_xname(xycsc->sc_dev));
                        break;
                default:
                        panic("xyc_submit_iorq adding");
                }
        }

        dmaiopb = xyc_chain(xycsc, iorq);        /* build chain */
        if (dmaiopb == NULL) { /* nothing doing? */
                if (type == XY_SUB_NORM || type == XY_SUB_NOQ)
                        return(XY_ERR_AOK);
                panic("xyc_submit_iorq: xyc_chain failed!");
        }

        XYC_GO(xycsc->xyc, dmaiopb);

        /* command now running, wrap it up */
        switch (type) {
        case XY_SUB_NORM:
        case XY_SUB_NOQ:
                return (XY_ERR_AOK);    /* success */
        case XY_SUB_WAIT:
                while (iorq->iopb->done == 0) {
                        (void) tsleep(iorq, PRIBIO, "xyciorq", 0);
                }
                return (iorq->errnum);
        case XY_SUB_POLL:
                return (xyc_piodriver(xycsc, iorq));
        default:
                panic("xyc_submit_iorq wrap up");
        }
        panic("xyc_submit_iorq");
        return 0;       /* not reached */
}


/*
 * xyc_chain: build a chain.  return dvma address of first element in
 * the chain.   iorq != NULL: means we only want that item on the chain.
 */

struct xy_iopb *
xyc_chain(struct xyc_softc *xycsc, struct xy_iorq *iorq)
{
        int togo, chain, hand;

        memset(xycsc->xy_chain, 0, sizeof(xycsc->xy_chain));

        /*
         * promote control IOPB to the top
         */
        if (iorq == NULL) {
                if ((XY_STATE(xycsc->reqs[XYC_CTLIOPB].mode) == XY_SUB_POLL ||
                     XY_STATE(xycsc->reqs[XYC_CTLIOPB].mode) == XY_SUB_WAIT) &&
                     xycsc->iopbase[XYC_CTLIOPB].done == 0)
                        iorq = &xycsc->reqs[XYC_CTLIOPB];
        }

        /*
         * special case: if iorq != NULL then we have a POLL or WAIT request.
         * we let these take priority and do them first.
         */
        if (iorq) {
                xycsc->xy_chain[0] = iorq;
                iorq->iopb->chen = 0;
                return(iorq->dmaiopb);
        }

        /*
         * NORM case: do round robin and maybe chain (if allowed and possible)
         */
        chain = 0;
        hand = xycsc->xy_hand;
        xycsc->xy_hand = (xycsc->xy_hand + 1) % XYC_MAXIOPB;

        for (togo = XYC_MAXIOPB; togo > 0;
             togo--, hand = (hand + 1) % XYC_MAXIOPB) {
                struct xy_iopb *iopb, *prev_iopb, *dmaiopb;

                if (XY_STATE(xycsc->reqs[hand].mode) != XY_SUB_NORM ||
                    xycsc->iopbase[hand].done)
                        continue;   /* not ready-for-i/o */

                xycsc->xy_chain[chain] = &xycsc->reqs[hand];
                iopb = xycsc->xy_chain[chain]->iopb;
                iopb->chen = 0;
                if (chain != 0) {
                        /* adding a link to a chain */
                        prev_iopb = xycsc->xy_chain[chain-1]->iopb;
                        prev_iopb->chen = 1;
                        dmaiopb = xycsc->xy_chain[chain]->dmaiopb;
                        prev_iopb->nxtiopb = ((u_long)dmaiopb) & 0xffff;
                } else {
                        /* head of chain */
                        iorq = xycsc->xy_chain[chain];
                }
                chain++;

                /* quit if chaining dis-allowed */
                if (xycsc->no_ols)
                        break;
        }

        return(iorq ? iorq->dmaiopb : NULL);
}

/*
 * xyc_piodriver
 *
 * programmed i/o driver.   this function takes over the computer
 * and drains off the polled i/o request.   it returns the status of the iorq
 * the caller is interesting in.
 */
int
xyc_piodriver(struct xyc_softc *xycsc, struct xy_iorq *iorq)
{
        int     nreset = 0;
        int     retval = 0;
        u_long  res;
#ifdef XYC_DEBUG
        printf("xyc_piodriver(%s, 0x%x)\n", device_xname(xycsc->sc_dev), iorq);
#endif

        while (iorq->iopb->done == 0) {

                res = xyc_unbusy(xycsc->xyc, XYC_MAXTIME);

                /* we expect some progress soon */
                if (res == XY_ERR_FAIL && nreset >= 2) {
                        xyc_reset(xycsc, 0, XY_RSET_ALL, XY_ERR_FAIL, 0);
#ifdef XYC_DEBUG
                        printf("xyc_piodriver: timeout\n");
#endif
                        return (XY_ERR_FAIL);
                }
                if (res == XY_ERR_FAIL) {
                        if (xyc_reset(xycsc, 0,
                                      (nreset++ == 0) ? XY_RSET_NONE : iorq,
                                      XY_ERR_FAIL,
                                      0) == XY_ERR_FAIL)
                                return (XY_ERR_FAIL);   /* flushes all but POLL
                                                         * requests, resets */
                        continue;
                }

                xyc_remove_iorq(xycsc);  /* may resubmit request */

                if (iorq->iopb->done == 0)
                        xyc_start(xycsc, iorq);
        }

        /* get return value */

        retval = iorq->errnum;

#ifdef XYC_DEBUG
        printf("xyc_piodriver: done, retval = 0x%x (%s)\n",
            iorq->errnum, xyc_e2str(iorq->errnum));
#endif

        /* start up any bufs that have queued */

        xyc_start(xycsc, NULL);

        return (retval);
}

/*
 * xyc_xyreset: reset one drive.   NOTE: assumes xyc was just reset.
 * we steal iopb[XYC_CTLIOPB] for this, but we put it back when we are done.
 */
void
xyc_xyreset(struct xyc_softc *xycsc, struct xy_softc *xysc)
{
        struct xy_iopb tmpiopb;
        struct xy_iopb *iopb;
        int     del;

        iopb = xycsc->ciopb;

        /* Save contents */
        memcpy(&tmpiopb, iopb, sizeof(struct xy_iopb));

        iopb->chen = iopb->done = iopb->errs = 0;
        iopb->ien = 0;
        iopb->com = XYCMD_RST;
        iopb->unit = xysc->xy_drive;

        XYC_GO(xycsc->xyc, xycsc->ciorq->dmaiopb);

        del = XYC_RESETUSEC;
        while (del > 0) {
                if ((xycsc->xyc->xyc_csr & XYC_GBSY) == 0)
                        break;
                DELAY(1);
                del--;
        }

        if (del <= 0 || iopb->errs) {
                printf("%s: off-line: %s\n", device_xname(xycsc->sc_dev),
                    xyc_e2str(iopb->errnum));
                del = xycsc->xyc->xyc_rsetup;
                if (xyc_unbusy(xycsc->xyc, XYC_RESETUSEC) == XY_ERR_FAIL)
                        panic("xyc_reset");
        } else {
                xycsc->xyc->xyc_csr = XYC_IPND; /* clear IPND */
        }

        /* Restore contents */
        memcpy(iopb, &tmpiopb, sizeof(struct xy_iopb));
}


/*
 * xyc_reset: reset everything: requests are marked as errors except
 * a polled request (which is resubmitted)
 */
int
xyc_reset(struct xyc_softc *xycsc, int quiet, struct xy_iorq *blastmode,
        int error, struct xy_softc *xysc)
{
        int     del = 0, lcv, retval = XY_ERR_AOK;

        /* soft reset hardware */

        if (!quiet)
                printf("%s: soft reset\n", device_xname(xycsc->sc_dev));
        del = xycsc->xyc->xyc_rsetup;
        del = xyc_unbusy(xycsc->xyc, XYC_RESETUSEC);
        if (del == XY_ERR_FAIL) {
                blastmode = XY_RSET_ALL;        /* dead, flush all requests */
                retval = XY_ERR_FAIL;
        }
        if (xysc)
                xyc_xyreset(xycsc, xysc);

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

        for (lcv = 0; lcv < XYC_MAXIOPB; lcv++) {
                register struct xy_iorq *iorq = &xycsc->reqs[lcv];

                if (XY_STATE(iorq->mode) != XY_SUB_POLL &&
                    XY_STATE(iorq->mode) != XY_SUB_WAIT &&
                    XY_STATE(iorq->mode) != XY_SUB_NORM)
                        /* is it active? */
                        continue;

                if (blastmode == XY_RSET_ALL ||
                                blastmode != iorq) {
                        /* failed */
                        iorq->errnum = error;
                        xycsc->iopbase[lcv].done = xycsc->iopbase[lcv].errs = 1;
                        switch (XY_STATE(iorq->mode)) {
                        case XY_SUB_NORM:
                            iorq->buf->b_error = EIO;
                            iorq->buf->b_resid = iorq->sectcnt * XYFM_BPS;

                            bus_dmamap_sync(xycsc->dmatag, iorq->dmamap, 0,
                                        iorq->dmamap->dm_mapsize,
                                        (iorq->buf->b_flags & B_READ)
                                                ? BUS_DMASYNC_POSTREAD
                                                : BUS_DMASYNC_POSTWRITE);

                            bus_dmamap_unload(xycsc->dmatag, iorq->dmamap);

                            (void)bufq_get(iorq->xy->xyq);
                            disk_unbusy(&xycsc->reqs[lcv].xy->sc_dk,
                                (xycsc->reqs[lcv].buf->b_bcount -
                                xycsc->reqs[lcv].buf->b_resid),
                                (xycsc->reqs[lcv].buf->b_flags & B_READ));
                            biodone(iorq->buf);
                            iorq->mode = XY_SUB_FREE;
                            break;
                        case XY_SUB_WAIT:
                            wakeup(iorq);
                        case XY_SUB_POLL:
                            iorq->mode =
                                XY_NEWSTATE(iorq->mode, XY_SUB_DONE);
                            break;
                        }

                } else {

                        /* resubmit, no need to do anything here */
                }
        }

        /*
         * now, if stuff is waiting, start it.
         * since we just reset it should go
         */
        xyc_start(xycsc, NULL);

        return (retval);
}

/*
 * xyc_start: start waiting buffers
 */

void
xyc_start(struct xyc_softc *xycsc, struct xy_iorq *iorq)
{
        int lcv;
        struct xy_softc *xy;

        if (iorq == NULL) {
                for (lcv = 0; lcv < XYC_MAXDEV ; lcv++) {
                        if ((xy = xycsc->sc_drives[lcv]) == NULL) continue;
                        if (bufq_peek(xy->xyq) == NULL) continue;
                        if (xy->xyrq->mode != XY_SUB_FREE) continue;
                        xyc_startbuf(xycsc, xy, bufq_peek(xy->xyq));
                }
        }
        xyc_submit_iorq(xycsc, iorq, XY_SUB_NOQ);
}

/*
 * xyc_remove_iorq: remove "done" IOPB's.
 */

int
xyc_remove_iorq(struct xyc_softc *xycsc)
{
        int     errnum, rq, comm, errs;
        struct xyc *xyc = xycsc->xyc;
        u_long  addr;
        struct xy_iopb *iopb;
        struct xy_iorq *iorq;
        struct buf *bp;

        if (xyc->xyc_csr & XYC_DERR) {
                /*
                 * DOUBLE 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.
                 */
                errnum = XY_ERR_DERR;
                aprint_error_dev(xycsc->sc_dev, "DOUBLE ERROR!\n");
                if (xyc_reset(xycsc, 0, XY_RSET_ALL, errnum, 0) != XY_ERR_AOK) {
                        aprint_error_dev(xycsc->sc_dev, "soft reset failed!\n");
                        panic("xyc_remove_iorq: controller DEAD");
                }
                return (XY_ERR_AOK);
        }

        /*
         * get iopb that is done, loop down the chain
         */

        if (xyc->xyc_csr & XYC_ERR) {
                xyc->xyc_csr = XYC_ERR; /* clear error condition */
        }
        if (xyc->xyc_csr & XYC_IPND) {
                xyc->xyc_csr = XYC_IPND; /* clear interrupt */
        }

        for (rq = 0; rq < XYC_MAXIOPB; rq++) {
                iorq = xycsc->xy_chain[rq];
                if (iorq == NULL) break; /* done ! */
                if (iorq->mode == 0 || XY_STATE(iorq->mode) == XY_SUB_DONE)
                        continue;       /* free, or done */
                iopb = iorq->iopb;
                if (iopb->done == 0)
                        continue;       /* not done yet */

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

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

                /* handle non-fatal errors */

                if (errs &&
                    xyc_error(xycsc, iorq, iopb, comm) == XY_ERR_AOK)
                        continue;       /* AOK: we resubmitted it */


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

                if ((iorq->mode & XY_MODE_VERBO) && iorq->lasterror)
                        xyc_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 & XY_MODE_B144) != 0 && errs == 0 &&
                    (comm == XYCMD_RD || comm == XYCMD_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
                         *
                         */
                        XYC_ADVANCE(iorq, 1);   /* advance 1 sector */

                        /* exit b144 mode */
                        iorq->mode = iorq->mode & (~XY_MODE_B144);

                        if (iorq->sectcnt) {    /* more to go! */
                                iorq->lasterror = iorq->errnum = iopb->errnum = 0;
                                iopb->errs = iopb->done = 0;
                                iorq->tries = 0;
                                iopb->scnt = iorq->sectcnt;
                                iopb->cyl = iorq->blockno /
                                                iorq->xy->sectpercyl;
                                iopb->head =
                                        (iorq->blockno / iorq->xy->nhead) %
                                                iorq->xy->nhead;
                                iopb->sect = iorq->blockno % XYFM_BPS;
                                addr = (u_long) iorq->dbuf;
                                iopb->dataa = (addr & 0xffff);
                                iopb->datar = ((addr & 0xff0000) >> 16);
                                /* will resubit at end */
                                continue;
                        }
                }
                /* final cleanup, totally done with this request */

                switch (XY_STATE(iorq->mode)) {
                case XY_SUB_NORM:
                        bp = iorq->buf;
                        if (errs) {
                                bp->b_error = EIO;
                                bp->b_resid = iorq->sectcnt * XYFM_BPS;
                        } else {
                                bp->b_resid = 0;        /* done */
                        }
                        bus_dmamap_sync(xycsc->dmatag, iorq->dmamap, 0,
                                        iorq->dmamap->dm_mapsize,
                                        (iorq->buf->b_flags & B_READ)
                                                ? BUS_DMASYNC_POSTREAD
                                                : BUS_DMASYNC_POSTWRITE);

                        bus_dmamap_unload(xycsc->dmatag, iorq->dmamap);

                        (void)bufq_get(iorq->xy->xyq);
                        disk_unbusy(&iorq->xy->sc_dk,
                            (bp->b_bcount - bp->b_resid),
                            (bp->b_flags & B_READ));
                        iorq->mode = XY_SUB_FREE;
                        biodone(bp);
                        break;
                case XY_SUB_WAIT:
                        iorq->mode = XY_NEWSTATE(iorq->mode, XY_SUB_DONE);
                        wakeup(iorq);
                        break;
                case XY_SUB_POLL:
                        iorq->mode = XY_NEWSTATE(iorq->mode, XY_SUB_DONE);
                        break;
                }
        }

        return (XY_ERR_AOK);
}

/*
 * xyc_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 errnum is the new one.
 * - if still_trying is not true, then if we ever had an error it
 *   is in lasterror. also, if iorq->errnum == 0, then we recovered
 *   from that error (otherwise iorq->errnum == iorq->lasterror).
 */
void
xyc_perror(struct xy_iorq *iorq, struct xy_iopb *iopb, int still_trying)
{

        int     error = iorq->lasterror;

        printf("%s", (iorq->xy) ? device_xname(iorq->xy->sc_dev)
            : device_xname(iorq->xyc->sc_dev));
        if (iorq->buf)
                printf("%c: ", 'a' + (char)DISKPART(iorq->buf->b_dev));
        if (iopb->com == XYCMD_RD || iopb->com == XYCMD_WR)
                printf("%s %d/%d/%d: ",
                        (iopb->com == XYCMD_RD) ? "read" : "write",
                        iopb->cyl, iopb->head, iopb->sect);
        printf("%s", xyc_e2str(error));

        if (still_trying)
                printf(" [still trying, new error=%s]", xyc_e2str(iorq->errnum));
        else
                if (iorq->errnum == 0)
                        printf(" [recovered in %d tries]", iorq->tries);

        printf("\n");
}

/*
 * xyc_error: non-fatal error encountered... recover.
 * return AOK if resubmitted, return FAIL if this iopb is done
 */
int
xyc_error(struct xyc_softc *xycsc, struct xy_iorq *iorq, struct xy_iopb *iopb,
        int comm)
{
        int     errnum = iorq->errnum;
        int     erract = xyc_entoact(errnum);
        int     oldmode, advance;

        if (erract == XY_ERA_RSET) {    /* some errors require a reset */
                oldmode = iorq->mode;
                iorq->mode = XY_SUB_DONE | (~XY_SUB_MASK & oldmode);
                /* make xyc_start ignore us */
                xyc_reset(xycsc, 1, XY_RSET_NONE, errnum, iorq->xy);
                iorq->mode = oldmode;
        }
        /* check for read/write to a sector in bad144 table if bad: redirect
         * request to bad144 area */

        if ((comm == XYCMD_RD || comm == XYCMD_WR) &&
            (iorq->mode & XY_MODE_B144) == 0) {
                int i;

                advance = iorq->sectcnt - iopb->scnt;
                XYC_ADVANCE(iorq, advance);
                if ((i = bad144_isbad_chs(iorq->xy->bad144,
                            iorq->blockno / iorq->xy->sectpercyl,
                            (iorq->blockno / iorq->xy->nsect) % iorq->xy->nhead,
                            iorq->blockno % iorq->xy->nsect)) != -1) {
                        iorq->mode |= XY_MODE_B144;     /* enter bad144 mode &
                                                         * redirect */
                        iopb->errnum = iopb->done = iopb->errs = 0;
                        iopb->scnt = 1;
                        iopb->cyl = (iorq->xy->ncyl + iorq->xy->acyl) - 2;
                        /* second to last acyl */
                        i = iorq->xy->sectpercyl - 1 - i;       /* follow bad144
                                                                 * standard */
                        iopb->head = i / iorq->xy->nhead;
                        iopb->sect = i % iorq->xy->nhead;
                        /* will resubmit when we come out of remove_iorq */
                        return (XY_ERR_AOK);    /* recovered! */
                }
        }

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

        if ((erract == XY_ERA_RSET || erract == XY_ERA_HARD)
            && iorq->tries < XYC_MAXTRIES) {    /* retry? */
                iorq->tries++;
                iorq->errnum = iopb->errnum = iopb->done = iopb->errs = 0;
                /* will resubmit at end of remove_iorq */
                return (XY_ERR_AOK);    /* recovered! */
        }

        /* failed to recover from this error */
        return (XY_ERR_FAIL);
}

/*
 * xyc_tick: make sure xy is still alive and ticking (err, kicking).
 */
void
xyc_tick(void *arg)
{
        struct xyc_softc *xycsc = arg;
        int     lcv, s, reset = 0;

        /* reduce ttl for each request if one goes to zero, reset xyc */
        s = splbio();
        for (lcv = 0; lcv < XYC_MAXIOPB; lcv++) {
                if (xycsc->reqs[lcv].mode == 0 ||
                    XY_STATE(xycsc->reqs[lcv].mode) == XY_SUB_DONE)
                        continue;
                xycsc->reqs[lcv].ttl--;
                if (xycsc->reqs[lcv].ttl == 0)
                        reset = 1;
        }
        if (reset) {
                printf("%s: watchdog timeout\n", device_xname(xycsc->sc_dev));
                xyc_reset(xycsc, 0, XY_RSET_NONE, XY_ERR_FAIL, NULL);
        }
        splx(s);

        /* until next time */

        callout_reset(&xycsc->sc_tick_ch, XYC_TICKCNT, xyc_tick, xycsc);
}

/*
 * xyc_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.
 *
 * XXX missing a few commands (see the 7053 driver for ideas)
 */
int
xyc_ioctlcmd(struct xy_softc *xy, dev_t dev, struct xd_iocmd *xio)
{
        int     s, rqno, dummy = 0;
        char *dvmabuf = NULL, *buf = NULL;
        struct xyc_softc *xycsc;
        int                     rseg, error;
        bus_dma_segment_t       seg;

        /* check sanity of requested command */

        switch (xio->cmd) {

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

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

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

                break;

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

        xycsc = xy->parent;

        /* create DVMA buffer for request if needed */
        if (xio->dlen) {
                bus_addr_t busbuf;

                if ((error = xy_dmamem_alloc(xycsc->dmatag, xycsc->auxmap,
                                             &seg, &rseg,
                                             xio->dlen, (void **)&buf,
                                             &busbuf)) != 0) {
                        return (error);
                }
                dvmabuf = (void *)(u_long)BUS_ADDR_PADDR(busbuf);

                if (xio->cmd == XYCMD_WR) {
                        if ((error = copyin(xio->dptr, buf, xio->dlen)) != 0) {
                                bus_dmamem_unmap(xycsc->dmatag, buf, xio->dlen);
                                bus_dmamem_free(xycsc->dmatag, &seg, rseg);
                                return (error);
                        }
                }
        }
        /* do it! */

        error = 0;
        s = splbio();
        rqno = xyc_cmd(xycsc, xio->cmd, xio->subfn, xy->xy_drive, xio->block,
            xio->sectcnt, dvmabuf, XY_SUB_WAIT);
        if (rqno == XY_ERR_FAIL) {
                error = EIO;
                goto done;
        }
        xio->errnum = xycsc->ciorq->errnum;
        xio->tries = xycsc->ciorq->tries;
        XYC_DONE(xycsc, dummy);

        if (xio->cmd == XYCMD_RD)
                error = copyout(buf, xio->dptr, xio->dlen);

done:
        splx(s);
        if (dvmabuf) {
                xy_dmamem_free(xycsc->dmatag, xycsc->auxmap, &seg, rseg,
                                xio->dlen, buf);
        }
        return (error);
}

/*
 * xyc_e2str: convert error code number into an error string
 */
const char *
xyc_e2str(int no)
{
        switch (no) {
        case XY_ERR_FAIL:
                return ("Software fatal error");
        case XY_ERR_DERR:
                return ("DOUBLE ERROR");
        case XY_ERR_AOK:
                return ("Successful completion");
        case XY_ERR_IPEN:
                return("Interrupt pending");
        case XY_ERR_BCFL:
                return("Busy conflict");
        case XY_ERR_TIMO:
                return("Operation timeout");
        case XY_ERR_NHDR:
                return("Header not found");
        case XY_ERR_HARD:
                return("Hard ECC error");
        case XY_ERR_ICYL:
                return("Illegal cylinder address");
        case XY_ERR_ISEC:
                return("Illegal sector address");
        case XY_ERR_SMAL:
                return("Last sector too small");
        case XY_ERR_SACK:
                return("Slave ACK error (non-existent memory)");
        case XY_ERR_CHER:
                return("Cylinder and head/header error");
        case XY_ERR_SRTR:
                return("Auto-seek retry successful");
        case XY_ERR_WPRO:
                return("Write-protect error");
        case XY_ERR_UIMP:
                return("Unimplemented command");
        case XY_ERR_DNRY:
                return("Drive not ready");
        case XY_ERR_SZER:
                return("Sector count zero");
        case XY_ERR_DFLT:
                return("Drive faulted");
        case XY_ERR_ISSZ:
                return("Illegal sector size");
        case XY_ERR_SLTA:
                return("Self test A");
        case XY_ERR_SLTB:
                return("Self test B");
        case XY_ERR_SLTC:
                return("Self test C");
        case XY_ERR_SOFT:
                return("Soft ECC error");
        case XY_ERR_SFOK:
                return("Soft ECC error recovered");
        case XY_ERR_IHED:
                return("Illegal head");
        case XY_ERR_DSEQ:
                return("Disk sequencer error");
        case XY_ERR_SEEK:
                return("Seek error");
        default:
                return ("Unknown error");
        }
}

int
xyc_entoact(int errnum)
{
  switch (errnum) {
    case XY_ERR_FAIL:   case XY_ERR_DERR:       case XY_ERR_IPEN:
    case XY_ERR_BCFL:   case XY_ERR_ICYL:       case XY_ERR_ISEC:
    case XY_ERR_UIMP:   case XY_ERR_SZER:       case XY_ERR_ISSZ:
    case XY_ERR_SLTA:   case XY_ERR_SLTB:       case XY_ERR_SLTC:
    case XY_ERR_IHED:   case XY_ERR_SACK:       case XY_ERR_SMAL:

        return(XY_ERA_PROG); /* program error ! */

    case XY_ERR_TIMO:   case XY_ERR_NHDR:       case XY_ERR_HARD:
    case XY_ERR_DNRY:   case XY_ERR_CHER:       case XY_ERR_SEEK:
    case XY_ERR_SOFT:

        return(XY_ERA_HARD); /* hard error, retry */

    case XY_ERR_DFLT:   case XY_ERR_DSEQ:

        return(XY_ERA_RSET); /* hard error reset */

    case XY_ERR_SRTR:   case XY_ERR_SFOK:       case XY_ERR_AOK:

        return(XY_ERA_SOFT); /* an FYI error */

    case XY_ERR_WPRO:

        return(XY_ERA_WPRO); /* write protect */
  }

  return(XY_ERA_PROG); /* ??? */
}