/*      $NetBSD: rd.c,v 1.45 2023/02/12 16:04:57 andvar Exp $ */

/*-
 * Copyright (c) 1996-2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1982, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * from: Utah $Hdr: rd.c 1.44 92/12/26$
 *
 *      @(#)rd.c        8.2 (Berkeley) 5/19/94
 */

/*
 * CS80/SS80 disk driver
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rd.c,v 1.45 2023/02/12 16:04:57 andvar Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/callout.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/endian.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/stat.h>

#include <sys/rndsource.h>

#include <dev/gpib/gpibvar.h>
#include <dev/gpib/cs80busvar.h>

#include <dev/gpib/rdreg.h>

#include "ioconf.h"

#ifdef DEBUG
int     rddebug = 0xff;
#define RDB_FOLLOW      0x01
#define RDB_STATUS      0x02
#define RDB_IDENT       0x04
#define RDB_IO          0x08
#define RDB_ASYNC       0x10
#define RDB_ERROR       0x80
#define DPRINTF(mask, str)      if (rddebug & (mask)) printf str
#else
#define DPRINTF(mask, str)      /* nothing */
#endif

struct  rd_softc {
        device_t sc_dev;
        gpib_chipset_tag_t sc_ic;
        gpib_handle_t sc_hdl;

        struct  disk sc_dk;

        int     sc_slave;               /* GPIB slave */
        int     sc_punit;               /* physical unit on slave */

        int     sc_flags;
#define RDF_ALIVE       0x01
#define RDF_SEEK        0x02
#define RDF_SWAIT       0x04
#define RDF_OPENING     0x08
#define RDF_CLOSING     0x10
#define RDF_WANTED      0x20
#define RDF_WLABEL      0x40

        u_int16_t sc_type;
        u_int8_t *sc_addr;
        int     sc_resid;
        struct  rd_iocmd sc_ioc;
        struct  bufq_state *sc_tab;
        int     sc_active;
        int     sc_errcnt;

        struct  callout sc_restart_ch;

        krndsource_t rnd_source;
};

#define RDUNIT(dev)                     DISKUNIT(dev)
#define RDPART(dev)                     DISKPART(dev)
#define RDMAKEDEV(maj, unit, part)      MAKEDISKDEV(maj, unit, part)
#define RDLABELDEV(dev) (RDMAKEDEV(major(dev), RDUNIT(dev), RAW_PART))

#define RDRETRY         5
#define RDWAITC         1       /* min time for timeout in seconds */

int     rderrthresh = RDRETRY-1;        /* when to start reporting errors */

/*
 * Misc. HW description, indexed by sc_type.
 * Used for mapping 256-byte sectors for 512-byte sectors
 */
const struct rdidentinfo {
        u_int16_t ri_hwid;              /* 2 byte HW id */
        u_int16_t ri_maxunum;           /* maximum allowed unit number */
        const char *ri_desc;            /* drive type description */
        int     ri_nbpt;                /* DEV_BSIZE blocks per track */
        int     ri_ntpc;                /* tracks per cylinder */
        int     ri_ncyl;                /* cylinders per unit */
        int     ri_nblocks;             /* DEV_BSIZE blocks on disk */
} rdidentinfo[] = {
        { RD7946AID,    0,      "7945A",        NRD7945ABPT,
          NRD7945ATRK,  968,     108416 },

        { RD9134DID,    1,      "9134D",        NRD9134DBPT,
          NRD9134DTRK,  303,      29088 },

        { RD9134LID,    1,      "9122S",        NRD9122SBPT,
          NRD9122STRK,  77,        1232 },

        { RD7912PID,    0,      "7912P",        NRD7912PBPT,
          NRD7912PTRK,  572,     128128 },

        { RD7914PID,    0,      "7914P",        NRD7914PBPT,
          NRD7914PTRK,  1152,    258048 },

        { RD7958AID,    0,      "7958A",        NRD7958ABPT,
          NRD7958ATRK,  1013,    255276 },

        { RD7957AID,    0,      "7957A",        NRD7957ABPT,
          NRD7957ATRK,  1036,    159544 },

        { RD7933HID,    0,      "7933H",        NRD7933HBPT,
          NRD7933HTRK,  1321,    789958 },

        { RD9134LID,    1,      "9134L",        NRD9134LBPT,
          NRD9134LTRK,  973,      77840 },

        { RD7936HID,    0,      "7936H",        NRD7936HBPT,
          NRD7936HTRK,  698,     600978 },

        { RD7937HID,    0,      "7937H",        NRD7937HBPT,
          NRD7937HTRK,  698,    1116102 },

        { RD7914CTID,   0,      "7914CT",       NRD7914PBPT,
          NRD7914PTRK,  1152,    258048 },

        { RD7946AID,    0,      "7946A",        NRD7945ABPT,
          NRD7945ATRK,  968,     108416 },

        { RD9134LID,    1,      "9122D",        NRD9122SBPT,
          NRD9122STRK,  77,        1232 },

        { RD7957BID,    0,      "7957B",        NRD7957BBPT,
          NRD7957BTRK,  1269,    159894 },

        { RD7958BID,    0,      "7958B",        NRD7958BBPT,
          NRD7958BTRK,  786,     297108 },

        { RD7959BID,    0,      "7959B",        NRD7959BBPT,
          NRD7959BTRK,  1572,    594216 },

        { RD2200AID,    0,      "2200A",        NRD2200ABPT,
          NRD2200ATRK,  1449,    654948 },

        { RD2203AID,    0,      "2203A",        NRD2203ABPT,
          NRD2203ATRK,  1449,   1309896 }
};
int numrdidentinfo = sizeof(rdidentinfo) / sizeof(rdidentinfo[0]);

int     rdlookup(int, int, int);
int     rdgetinfo(struct rd_softc *);
void    rdrestart(void *);
struct buf *rdfinish(struct rd_softc *, struct buf *);

void    rdgetcompatlabel(struct rd_softc *, struct disklabel *);
void    rdgetdefaultlabel(struct rd_softc *, struct disklabel *);
void    rdrestart(void *);
void    rdustart(struct rd_softc *);
struct buf *rdfinish(struct rd_softc *, struct buf *);
void    rdcallback(void *, int);
void    rdstart(struct rd_softc *);
void    rdintr(struct rd_softc *);
int     rderror(struct rd_softc *);

int     rdmatch(device_t, cfdata_t, void *);
void    rdattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(rd, sizeof(struct rd_softc),
        rdmatch, rdattach, NULL, NULL);


dev_type_open(rdopen);
dev_type_close(rdclose);
dev_type_read(rdread);
dev_type_write(rdwrite);
dev_type_ioctl(rdioctl);
dev_type_strategy(rdstrategy);
dev_type_dump(rddump);
dev_type_size(rdsize);

const struct bdevsw rd_bdevsw = {
        .d_open = rdopen,
        .d_close = rdclose,
        .d_strategy = rdstrategy,
        .d_ioctl = rdioctl,
        .d_dump = rddump,
        .d_psize = rdsize,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

const struct cdevsw rd_cdevsw = {
        .d_open = rdopen,
        .d_close = rdclose,
        .d_read = rdread,
        .d_write = rdwrite,
        .d_ioctl = rdioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = D_DISK
};

int
rdlookup(int id, int slave, int punit)
{
        int i;

        for (i = 0; i < numrdidentinfo; i++) {
                if (rdidentinfo[i].ri_hwid == id)
                        break;
        }
        if (i == numrdidentinfo || punit > rdidentinfo[i].ri_maxunum)
                return (-1);
        return (i);
}

int
rdmatch(device_t parent, cfdata_t match, void *aux)
{
        struct cs80bus_attach_args *ca = aux;

        if (rdlookup(ca->ca_id, ca->ca_slave, ca->ca_punit) < 0)
                return (0);
        return (1);
}

void
rdattach(device_t parent, device_t self, void *aux)
{
        struct rd_softc *sc = device_private(self);
        struct cs80bus_attach_args *ca = aux;
        struct cs80_description csd;
        char name[7];
        int type, i, n;

        sc->sc_dev = self;
        sc->sc_ic = ca->ca_ic;
        sc->sc_slave = ca->ca_slave;
        sc->sc_punit = ca->ca_punit;

        if ((type = rdlookup(ca->ca_id, ca->ca_slave, ca->ca_punit)) < 0)
                return;

        if (cs80reset(parent, sc->sc_slave, sc->sc_punit)) {
                aprint_normal("\n");
                aprint_error_dev(sc->sc_dev, "can't reset device\n");
                return;
        }

        if (cs80describe(parent, sc->sc_slave, sc->sc_punit, &csd)) {
                aprint_normal("\n");
                aprint_error_dev(sc->sc_dev,
                    "didn't respond to describe command\n");
                return;
        }
        memset(name, 0, sizeof(name));
        for (i=0, n=0; i<3; i++) {
                name[n++] = (csd.d_name[i] >> 4) + '0';
                name[n++] = (csd.d_name[i] & 0x0f) + '0';
        }

#ifdef DEBUG
        if (rddebug & RDB_IDENT) {
                printf("\n%s: name: ('%s')\n",
                    device_xname(sc->sc_dev), name);
                printf("  iuw %x, maxxfr %d, ctype %d\n",
                    csd.d_iuw, csd.d_cmaxxfr, csd.d_ctype);
                printf("  utype %d, bps %d, blkbuf %d, burst %d, blktime %d\n",
                    csd.d_utype, csd.d_sectsize,
                    csd.d_blkbuf, csd.d_burstsize, csd.d_blocktime);
                printf("  avxfr %d, ort %d, atp %d, maxint %d, fv %x, rv %x\n",
                    csd.d_uavexfr, csd.d_retry, csd.d_access,
                    csd.d_maxint, csd.d_fvbyte, csd.d_rvbyte);
                printf("  maxcyl/head/sect %d/%d/%d, maxvsect %d, inter %d\n",
                    csd.d_maxcylhead >> 8, csd.d_maxcylhead & 0xff,
                    csd.d_maxsect, csd.d_maxvsectl, csd.d_interleave);
                printf("%s", device_xname(sc->sc_dev));
        }
#endif

        /*
         * Take care of a couple of anomalies:
         * 1. 7945A and 7946A both return same HW id
         * 2. 9122S and 9134D both return same HW id
         * 3. 9122D and 9134L both return same HW id
         */
        switch (ca->ca_id) {
        case RD7946AID:
                if (memcmp(name, "079450", 6) == 0)
                        type = RD7945A;
                else
                        type = RD7946A;
                break;

        case RD9134LID:
                if (memcmp(name, "091340", 6) == 0)
                        type = RD9134L;
                else
                        type = RD9122D;
                break;

        case RD9134DID:
                if (memcmp(name, "091220", 6) == 0)
                        type = RD9122S;
                else
                        type = RD9134D;
                break;
        }

        sc->sc_type = type;

        /*
         * XXX We use DEV_BSIZE instead of the sector size value pulled
         * XXX off the driver because all of this code assumes 512 byte
         * XXX blocks.  ICK!
         */
        printf(": %s\n", rdidentinfo[type].ri_desc);
        printf("%s: %d cylinders, %d heads, %d blocks, %d bytes/block\n",
            device_xname(sc->sc_dev), rdidentinfo[type].ri_ncyl,
            rdidentinfo[type].ri_ntpc, rdidentinfo[type].ri_nblocks,
            DEV_BSIZE);

        bufq_alloc(&sc->sc_tab, "fcfs", 0);

        /*
         * Initialize and attach the disk structure.
         */
        memset(&sc->sc_dk, 0, sizeof(sc->sc_dk));
        disk_init(&sc->sc_dk, device_xname(sc->sc_dev), NULL);
        disk_attach(&sc->sc_dk);

        callout_init(&sc->sc_restart_ch, 0);

        if (gpibregister(sc->sc_ic, sc->sc_slave, rdcallback, sc,
            &sc->sc_hdl)) {
                aprint_error_dev(sc->sc_dev, "can't register callback\n");
                return;
        }

        sc->sc_flags = RDF_ALIVE;
#ifdef DEBUG
        /* always report errors */
        if (rddebug & RDB_ERROR)
                rderrthresh = 0;
#endif
        /*
         * attach the device into the random source list
         */
        rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
                          RND_TYPE_DISK, RND_FLAG_DEFAULT);
}

/*
 * Read or construct a disklabel
 */
int
rdgetinfo(struct rd_softc *sc)
{
        struct disklabel *lp = sc->sc_dk.dk_label;
        struct partition *pi;
        const char *msg;

        memset(sc->sc_dk.dk_cpulabel, 0, sizeof(struct cpu_disklabel));

        rdgetdefaultlabel(sc, lp);

        /*
         * Call the generic disklabel extraction routine
         */
        msg = readdisklabel(RDMAKEDEV(0, device_unit(sc->sc_dev), RAW_PART),
            rdstrategy, lp, NULL);
        if (msg == NULL)
                return (0);

        pi = lp->d_partitions;
        printf("%s: WARNING: %s\n", device_xname(sc->sc_dev), msg);

        pi[RAW_PART].p_size = rdidentinfo[sc->sc_type].ri_nblocks;
        lp->d_npartitions = RAW_PART+1;
        pi[0].p_size = 0;

        return (0);
}

int
rdopen(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct rd_softc *sc;
        int error, mask, part;

        sc = device_lookup_private(&rd_cd, RDUNIT(dev));
        if (sc == NULL || (sc->sc_flags & RDF_ALIVE) ==0)
                return (ENXIO);

        /*
         * Wait for any pending opens/closes to complete
         */
        while (sc->sc_flags & (RDF_OPENING | RDF_CLOSING))
                (void) tsleep(sc, PRIBIO, "rdopen", 0);

        /*
         * On first open, get label and partition info.
         * We may block reading the label, so be careful
         * to stop any other opens.
         */
        if (sc->sc_dk.dk_openmask == 0) {
                sc->sc_flags |= RDF_OPENING;
                error = rdgetinfo(sc);
                sc->sc_flags &= ~RDF_OPENING;
                wakeup((void *)sc);
                if (error)
                        return (error);
        }

        part = RDPART(dev);
        mask = 1 << part;

        /* Check that the partition exists. */
        if (part != RAW_PART && (part > sc->sc_dk.dk_label->d_npartitions ||
            sc->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED))
                return (ENXIO);

        /* Ensure only one open at a time. */
        switch (mode) {
        case S_IFCHR:
                sc->sc_dk.dk_copenmask |= mask;
                break;
        case S_IFBLK:
                sc->sc_dk.dk_bopenmask |= mask;
                break;
        }
        sc->sc_dk.dk_openmask =
            sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;

        return (0);
}

int
rdclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct rd_softc *sc;
        struct disk *dk;
        int mask, s;

        sc = device_lookup_private(&rd_cd, RDUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        dk = &sc->sc_dk;

        mask = 1 << RDPART(dev);
        if (mode == S_IFCHR)
                dk->dk_copenmask &= ~mask;
        else
                dk->dk_bopenmask &= ~mask;
        dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
        /*
         * On last close, we wait for all activity to cease since
         * the label/partition info will become invalid.  Since we
         * might sleep, we must block any opens while we are here.
         * Note we don't have to about other closes since we know
         * we are the last one.
         */
        if (dk->dk_openmask == 0) {
                sc->sc_flags |= RDF_CLOSING;
                s = splbio();
                while (sc->sc_active) {
                        sc->sc_flags |= RDF_WANTED;
                        (void) tsleep(&sc->sc_tab, PRIBIO, "rdclose", 0);
                }
                splx(s);
                sc->sc_flags &= ~(RDF_CLOSING | RDF_WLABEL);
                wakeup((void *)sc);
        }
        return (0);
}

void
rdstrategy(struct buf *bp)
{
        struct rd_softc *sc;
        struct partition *pinfo;
        daddr_t bn;
        int sz, s;
        int offset;

        sc = device_lookup_private(&rd_cd, RDUNIT(bp->b_dev));

        DPRINTF(RDB_FOLLOW,
            ("rdstrategy(%p): dev %" PRIx64 ", bn %" PRId64 ", bcount %d, %c\n",
            bp, bp->b_dev, bp->b_blkno, bp->b_bcount,
            (bp->b_flags & B_READ) ? 'R' : 'W'));

        bn = bp->b_blkno;
        sz = howmany(bp->b_bcount, DEV_BSIZE);
        pinfo = &sc->sc_dk.dk_label->d_partitions[RDPART(bp->b_dev)];

        /* Don't perform partition translation on RAW_PART. */
        offset = (RDPART(bp->b_dev) == RAW_PART) ? 0 : pinfo->p_offset;

        if (RDPART(bp->b_dev) != RAW_PART) {
                /*
                 * XXX This block of code belongs in
                 * XXX bounds_check_with_label()
                 */

                if (bn < 0 || bn + sz > pinfo->p_size) {
                        sz = pinfo->p_size - bn;
                        if (sz == 0) {
                                bp->b_resid = bp->b_bcount;
                                goto done;
                        }
                        if (sz < 0) {
                                bp->b_error = EINVAL;
                                goto done;
                        }
                        bp->b_bcount = dbtob(sz);
                }
                /*
                 * Check for write to write protected label
                 */
                if (bn + offset <= LABELSECTOR &&
#if LABELSECTOR != 0
                    bn + offset + sz > LABELSECTOR &&
#endif
                    !(bp->b_flags & B_READ) && !(sc->sc_flags & RDF_WLABEL)) {
                        bp->b_error = EROFS;
                        goto done;
                }
        }
        bp->b_rawblkno = bn + offset;
        s = splbio();
        bufq_put(sc->sc_tab, bp);
        if (sc->sc_active == 0) {
                sc->sc_active = 1;
                rdustart(sc);
        }
        splx(s);
        return;
done:
        biodone(bp);
}

/*
 * Called from timeout() when handling maintenance releases
 * callout from timeouts
 */
void
rdrestart(void *arg)
{
        int s = splbio();
        rdustart((struct rd_softc *)arg);
        splx(s);
}


/* called by rdstrategy() to start a block transfer */
/* called by rdrestart() when handingly timeouts */
/* called by rdintr() */
void
rdustart(struct rd_softc *sc)
{
        struct buf *bp;

        bp = bufq_peek(sc->sc_tab);
        sc->sc_addr = bp->b_data;
        sc->sc_resid = bp->b_bcount;
        if (gpibrequest(sc->sc_ic, sc->sc_hdl))
                rdstart(sc);
}

struct buf *
rdfinish(struct rd_softc *sc, struct buf *bp)
{

        sc->sc_errcnt = 0;
        (void)bufq_get(sc->sc_tab);
        bp->b_resid = 0;
        biodone(bp);
        gpibrelease(sc->sc_ic, sc->sc_hdl);
        if ((bp = bufq_peek(sc->sc_tab)) != NULL)
                return (bp);
        sc->sc_active = 0;
        if (sc->sc_flags & RDF_WANTED) {
                sc->sc_flags &= ~RDF_WANTED;
                wakeup((void *)&sc->sc_tab);
        }
        return (NULL);
}

void
rdcallback(void *v, int action)
{
        struct rd_softc *sc = v;

        DPRINTF(RDB_FOLLOW, ("rdcallback: v=%p, action=%d\n", v, action));

        switch (action) {
        case GPIBCBF_START:
                rdstart(sc);
                break;
        case GPIBCBF_INTR:
                rdintr(sc);
                break;
#ifdef DEBUG
        default:
                DPRINTF(RDB_ERROR, ("rdcallback: unknown action %d\n",
                    action));
                break;
#endif
        }
}


/* called from rdustart() to start a transfer */
/* called from gpib interface as the initiator */
void
rdstart(struct rd_softc *sc)
{
        struct buf *bp = bufq_peek(sc->sc_tab);
        int slave, punit;

        slave = sc->sc_slave;
        punit = sc->sc_punit;

        DPRINTF(RDB_FOLLOW, ("rdstart(%s): bp %p, %c\n",
            device_xname(sc->sc_dev), bp, (bp->b_flags & B_READ) ? 'R' : 'W'));

again:

        sc->sc_flags |= RDF_SEEK;
        sc->sc_ioc.c_unit = CS80CMD_SUNIT(punit);
        sc->sc_ioc.c_volume = CS80CMD_SVOL(0);
        sc->sc_ioc.c_saddr = CS80CMD_SADDR;
        sc->sc_ioc.c_hiaddr = htobe16(0);
        sc->sc_ioc.c_addr = htobe32(RDBTOS(bp->b_rawblkno));
        sc->sc_ioc.c_nop2 = CS80CMD_NOP;
        sc->sc_ioc.c_slen = CS80CMD_SLEN;
        sc->sc_ioc.c_len = htobe32(sc->sc_resid);
        sc->sc_ioc.c_cmd = bp->b_flags & B_READ ? CS80CMD_READ : CS80CMD_WRITE;

        if (gpibsend(sc->sc_ic, slave, CS80CMD_SCMD, &sc->sc_ioc.c_unit,
            sizeof(sc->sc_ioc)-1) == sizeof(sc->sc_ioc)-1) {
                /* Instrumentation. */
                disk_busy(&sc->sc_dk);
                iostat_seek(sc->sc_dk.dk_stats);
                gpibawait(sc->sc_ic);
                return;
        }
        /*
         * Experience has shown that the gpibwait in this gpibsend will
         * occasionally timeout.  It appears to occur mostly on old 7914
         * drives with full maintenance tracks.  We should probably
         * integrate this with the backoff code in rderror.
         */

        DPRINTF(RDB_ERROR,
            ("rdstart: cmd %x adr %ul blk %" PRId64 " len %d ecnt %d\n",
            sc->sc_ioc.c_cmd, sc->sc_ioc.c_addr, bp->b_blkno, sc->sc_resid,
             sc->sc_errcnt));

        sc->sc_flags &= ~RDF_SEEK;
        cs80reset(device_parent(sc->sc_dev), slave, punit);
        if (sc->sc_errcnt++ < RDRETRY)
                goto again;
        printf("%s: rdstart err: cmd 0x%x sect %uld blk %" PRId64 " len %d\n",
               device_xname(sc->sc_dev), sc->sc_ioc.c_cmd, sc->sc_ioc.c_addr,
               bp->b_blkno, sc->sc_resid);
        bp->b_error = EIO;
        bp = rdfinish(sc, bp);
        if (bp) {
                sc->sc_addr = bp->b_data;
                sc->sc_resid = bp->b_bcount;
                if (gpibrequest(sc->sc_ic, sc->sc_hdl))
                        goto again;
        }
}

void
rdintr(struct rd_softc *sc)
{
        struct buf *bp;
        u_int8_t stat = 13;     /* in case gpibrecv fails */
        int rv, dir, restart, slave;

        slave = sc->sc_slave;
        bp = bufq_peek(sc->sc_tab);

        DPRINTF(RDB_FOLLOW, ("rdintr(%s): bp %p, %c, flags %x\n",
            device_xname(sc->sc_dev), bp, (bp->b_flags & B_READ) ? 'R' : 'W',
            sc->sc_flags));

        disk_unbusy(&sc->sc_dk, (bp->b_bcount - bp->b_resid),
                (bp->b_flags & B_READ));

        if (sc->sc_flags & RDF_SEEK) {
                sc->sc_flags &= ~RDF_SEEK;
                dir = (bp->b_flags & B_READ ? GPIB_READ : GPIB_WRITE);
                gpibxfer(sc->sc_ic, slave, CS80CMD_EXEC, sc->sc_addr,
                    sc->sc_resid, dir, dir == GPIB_READ);
                disk_busy(&sc->sc_dk);
                return;
        }
        if ((sc->sc_flags & RDF_SWAIT) == 0) {
                if (gpibpptest(sc->sc_ic, slave) == 0) {
                        /* Instrumentation. */
                        disk_busy(&sc->sc_dk);
                        sc->sc_flags |= RDF_SWAIT;
                        gpibawait(sc->sc_ic);
                        return;
                }
        } else
                sc->sc_flags &= ~RDF_SWAIT;
        rv = gpibrecv(sc->sc_ic, slave, CS80CMD_QSTAT, &stat, 1);
        if (rv != 1 || stat) {
                DPRINTF(RDB_ERROR,
                    ("rdintr: receive failed (rv=%d) or bad stat %d\n", rv,
                     stat));
                restart = rderror(sc);
                if (sc->sc_errcnt++ < RDRETRY) {
                        if (restart)
                                rdstart(sc);
                        return;
                }
                bp->b_error = EIO;
        }
        if (rdfinish(sc, bp) != NULL)
                rdustart(sc);
        rnd_add_uint32(&sc->rnd_source, bp->b_blkno);
}

/*
 * Deal with errors.
 * Returns 1 if request should be restarted,
 * 0 if we should just quietly give up.
 */
int
rderror(struct rd_softc *sc)
{
        struct cs80_stat css;
        struct buf *bp;
        daddr_t hwbn, pbn;

        DPRINTF(RDB_FOLLOW, ("rderror: sc=%p\n", sc));

        if (cs80status(device_parent(sc->sc_dev), sc->sc_slave,
            sc->sc_punit, &css)) {
                cs80reset(device_parent(sc->sc_dev), sc->sc_slave,
                    sc->sc_punit);
                return (1);
        }
#ifdef DEBUG
        if (rddebug & RDB_ERROR) {                      /* status info */
                printf("\n    volume: %d, unit: %d\n",
                       (css.c_vu>>4)&0xF, css.c_vu&0xF);
                printf("    reject 0x%x\n", css.c_ref);
                printf("    fault 0x%x\n", css.c_fef);
                printf("    access 0x%x\n", css.c_aef);
                printf("    info 0x%x\n", css.c_ief);
                printf("    block,  P1-P10: ");
                printf("0x%x", *(u_int32_t *)&css.c_raw[0]);
                printf("0x%x", *(u_int32_t *)&css.c_raw[4]);
                printf("0x%x\n", *(u_int16_t *)&css.c_raw[8]);
        }
#endif
        if (css.c_fef & FEF_REXMT)
                return (1);
        if (css.c_fef & FEF_PF) {
                cs80reset(device_parent(sc->sc_dev), sc->sc_slave,
                    sc->sc_punit);
                return (1);
        }
        /*
         * Unit requests release for internal maintenance.
         * We just delay awhile and try again later.  Use exponentially
         * increasing backoff ala ethernet drivers since we don't really
         * know how long the maintenance will take.  With RDWAITC and
         * RDRETRY as defined, the range is 1 to 32 seconds.
         */
        if (css.c_fef & FEF_IMR) {
                extern int hz;
                int rdtimo = RDWAITC << sc->sc_errcnt;
                DPRINTF(RDB_STATUS,
                    ("%s: internal maintenance, %d-second timeout\n",
                    device_xname(sc->sc_dev), rdtimo));
                gpibrelease(sc->sc_ic, sc->sc_hdl);
                callout_reset(&sc->sc_restart_ch, rdtimo * hz, rdrestart, sc);
                return (0);
        }
        /*
         * Only report error if we have reached the error reporting
         * threshold.  By default, this will only report after the
         * retry limit has been exceeded.
         */
        if (sc->sc_errcnt < rderrthresh)
                return (1);

        /*
         * First conjure up the block number at which the error occurred.
         */
        bp = bufq_peek(sc->sc_tab);
        pbn = sc->sc_dk.dk_label->d_partitions[RDPART(bp->b_dev)].p_offset;
        if ((css.c_fef & FEF_CU) || (css.c_fef & FEF_DR) ||
            (css.c_ief & IEF_RRMASK)) {
                /*
                 * Not all errors report a block number, just use b_blkno.
                 */
                hwbn = RDBTOS(pbn + bp->b_blkno);
                pbn = bp->b_blkno;
        } else {
                hwbn = css.c_blk;
                pbn = RDSTOB(hwbn) - pbn;
        }
#ifdef DEBUG
        if (rddebug & RDB_ERROR) {                      /* status info */
                printf("\n    volume: %d, unit: %d\n",
                       (css.c_vu>>4)&0xF, css.c_vu&0xF);
                printf("    reject 0x%x\n", css.c_ref);
                printf("    fault 0x%x\n", css.c_fef);
                printf("    access 0x%x\n", css.c_aef);
                printf("    info 0x%x\n", css.c_ief);
                printf("    block,  P1-P10: ");
                printf("    block: %" PRId64 ", P1-P10: ", hwbn);
                printf("0x%x", *(u_int32_t *)&css.c_raw[0]);
                printf("0x%x", *(u_int32_t *)&css.c_raw[4]);
                printf("0x%x\n", *(u_int16_t *)&css.c_raw[8]);
        }
#endif
#ifdef DEBUG
        if (rddebug & RDB_ERROR) {                      /* command */
                printf("    ioc: ");
                printf("0x%x", *(u_int32_t *)&sc->sc_ioc.c_pad);
                printf("0x%x", *(u_int16_t *)&sc->sc_ioc.c_hiaddr);
                printf("0x%x", *(u_int32_t *)&sc->sc_ioc.c_addr);
                printf("0x%x", *(u_int16_t *)&sc->sc_ioc.c_nop2);
                printf("0x%x", *(u_int32_t *)&sc->sc_ioc.c_len);
                printf("0x%x\n", *(u_int16_t *)&sc->sc_ioc.c_cmd);
                return (1);
        }
#endif
        /*
         * Now output a generic message suitable for badsect.
         * Note that we don't use harderr because it just prints
         * out b_blkno which is just the beginning block number
         * of the transfer, not necessary where the error occurred.
         */
        printf("%s%c: hard error, sector number %" PRId64 "\n",
            device_xname(sc->sc_dev), 'a'+RDPART(bp->b_dev), pbn);
        /*
         * Now report the status as returned by the hardware with
         * attempt at interpretation.
         */
        printf("%s %s error:", device_xname(sc->sc_dev),
            (bp->b_flags & B_READ) ? "read" : "write");
        printf(" unit %d, volume %d R0x%x F0x%x A0x%x I0x%x\n",
               css.c_vu&0xF, (css.c_vu>>4)&0xF,
               css.c_ref, css.c_fef, css.c_aef, css.c_ief);
        printf("P1-P10: ");
        printf("0x%x ", *(u_int32_t *)&css.c_raw[0]);
        printf("0x%x ", *(u_int32_t *)&css.c_raw[4]);
        printf("0x%x\n", *(u_int16_t *)&css.c_raw[8]);

        return (1);
}

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

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

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

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

int
rdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        struct rd_softc *sc;
        struct disklabel *lp;
        int error, flags;

        sc = device_lookup_private(&rd_cd, RDUNIT(dev));
        if (sc == NULL)
                return (ENXIO);
        lp = sc->sc_dk.dk_label;

        DPRINTF(RDB_FOLLOW, ("rdioctl: sc=%p\n", sc));

        error = disk_ioctl(&sc->sc_dk, dev, cmd, data, flag, l);
        if (error != EPASSTHROUGH)
                return error;

        switch (cmd) {
        case DIOCWLABEL:
                if ((flag & FWRITE) == 0)
                        return (EBADF);
                if (*(int *)data)
                        sc->sc_flags |= RDF_WLABEL;
                else
                        sc->sc_flags &= ~RDF_WLABEL;
                return (0);

        case DIOCSDINFO:
                if ((flag & FWRITE) == 0)
                        return (EBADF);
                return (setdisklabel(lp, (struct disklabel *)data,
                    (sc->sc_flags & RDF_WLABEL) ? 0 : sc->sc_dk.dk_openmask,
                    (struct cpu_disklabel *)0));

        case DIOCWDINFO:
                if ((flag & FWRITE) == 0)
                        return (EBADF);
                error = setdisklabel(lp, (struct disklabel *)data,
                    (sc->sc_flags & RDF_WLABEL) ? 0 : sc->sc_dk.dk_openmask,
                    (struct cpu_disklabel *)0);
                if (error)
                        return (error);
                flags = sc->sc_flags;
                sc->sc_flags = RDF_ALIVE | RDF_WLABEL;
                error = writedisklabel(RDLABELDEV(dev), rdstrategy, lp,
                    (struct cpu_disklabel *)0);
                sc->sc_flags = flags;
                return (error);

        case DIOCGDEFLABEL:
                rdgetdefaultlabel(sc, (struct disklabel *)data);
                return (0);
        }
        return (EINVAL);
}

void
rdgetdefaultlabel(struct rd_softc *sc, struct disklabel *lp)
{
        int type = sc->sc_type;

        memset((void *)lp, 0, sizeof(struct disklabel));

        lp->d_type = DKTYPE_HPIB /* DKTYPE_GPIB */;
        lp->d_secsize = DEV_BSIZE;
        lp->d_nsectors = rdidentinfo[type].ri_nbpt;
        lp->d_ntracks = rdidentinfo[type].ri_ntpc;
        lp->d_ncylinders = rdidentinfo[type].ri_ncyl;
        lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
        lp->d_secperunit = lp->d_ncylinders * lp->d_secpercyl;

        strncpy(lp->d_typename, rdidentinfo[type].ri_desc, 16);
        strncpy(lp->d_packname, "fictitious", 16);
        lp->d_rpm = 3000;
        lp->d_interleave = 1;
        lp->d_flags = 0;

        lp->d_partitions[RAW_PART].p_offset = 0;
        lp->d_partitions[RAW_PART].p_size =
            lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
        lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
        lp->d_npartitions = RAW_PART + 1;

        lp->d_magic = DISKMAGIC;
        lp->d_magic2 = DISKMAGIC;
        lp->d_checksum = dkcksum(lp);
}

int
rdsize(dev_t dev)
{
        struct rd_softc *sc;
        int psize, didopen = 0;

        sc = device_lookup_private(&rd_cd, RDUNIT(dev));
        if (sc == NULL || (sc->sc_flags & RDF_ALIVE) == 0)
                return (-1);

        /*
         * We get called very early on (via swapconf)
         * without the device being open so we may need
         * to handle it here.
         */
        if (sc->sc_dk.dk_openmask == 0) {
                if (rdopen(dev, FREAD | FWRITE, S_IFBLK, NULL))
                        return (-1);
                didopen = 1;
        }
        psize = sc->sc_dk.dk_label->d_partitions[RDPART(dev)].p_size *
            (sc->sc_dk.dk_label->d_secsize / DEV_BSIZE);
        if (didopen)
                (void) rdclose(dev, FREAD | FWRITE, S_IFBLK, NULL);
        return (psize);
}


static int rddoingadump;        /* simple mutex */

/*
 * Non-interrupt driven, non-dma dump routine.
 */
int
rddump(dev_t dev, daddr_t blkno, void *va, size_t size)
{
        struct rd_softc *sc;
        int sectorsize;         /* size of a disk sector */
        int nsects;             /* number of sectors in partition */
        int sectoff;            /* sector offset of partition */
        int totwrt;             /* total number of sectors left to write */
        int nwrt;               /* current number of sectors to write */
        int slave;
        struct disklabel *lp;
        u_int8_t stat;

        /* Check for recursive dump; if so, punt. */
        if (rddoingadump)
                return (EFAULT);
        rddoingadump = 1;

        sc = device_lookup_private(&rd_cd, RDUNIT(dev));
        if (sc == NULL || (sc->sc_flags & RDF_ALIVE) == 0)
                return (ENXIO);

        DPRINTF(RDB_FOLLOW, ("rddump: sc=%p\n", sc));

        slave = sc->sc_slave;

        /*
         * Convert to disk sectors.  Request must be a multiple of size.
         */
        lp = sc->sc_dk.dk_label;
        sectorsize = lp->d_secsize;
        if ((size % sectorsize) != 0)
                return (EFAULT);
        totwrt = size / sectorsize;
        blkno = dbtob(blkno) / sectorsize;      /* blkno in DEV_BSIZE units */

        nsects = lp->d_partitions[RDPART(dev)].p_size;
        sectoff = lp->d_partitions[RDPART(dev)].p_offset;

        /* Check transfer bounds against partition size. */
        if ((blkno < 0) || (blkno + totwrt) > nsects)
                return (EINVAL);

        /* Offset block number to start of partition. */
        blkno += sectoff;

        while (totwrt > 0) {
                nwrt = totwrt;          /* XXX */
#ifndef RD_DUMP_NOT_TRUSTED
                /*
                 * Fill out and send GPIB command.
                 */
                sc->sc_ioc.c_unit = CS80CMD_SUNIT(sc->sc_punit);
                sc->sc_ioc.c_volume = CS80CMD_SVOL(0);
                sc->sc_ioc.c_saddr = CS80CMD_SADDR;
                sc->sc_ioc.c_hiaddr = 0;
                sc->sc_ioc.c_addr = RDBTOS(blkno);
                sc->sc_ioc.c_nop2 = CS80CMD_NOP;
                sc->sc_ioc.c_slen = CS80CMD_SLEN;
                sc->sc_ioc.c_len = nwrt * sectorsize;
                sc->sc_ioc.c_cmd = CS80CMD_WRITE;
                (void) gpibsend(sc->sc_ic, slave, CS80CMD_SCMD,
                    &sc->sc_ioc.c_unit, sizeof(sc->sc_ioc)-3);
                if (gpibswait(sc->sc_ic, slave))
                        return (EIO);
                /*
                 * Send the data.
                 */
                (void) gpibsend(sc->sc_ic, slave, CS80CMD_EXEC, va,
                    nwrt * sectorsize);
                (void) gpibswait(sc->sc_ic, slave);
                (void) gpibrecv(sc->sc_ic, slave, CS80CMD_QSTAT, &stat, 1);
                if (stat)
                        return (EIO);
#else /* RD_DUMP_NOT_TRUSTED */
                /* Let's just talk about this first... */
                printf("%s: dump addr %p, blk %d\n", device_xname(sc->sc_dev),
                    va, blkno);
                delay(500 * 1000);      /* half a second */
#endif /* RD_DUMP_NOT_TRUSTED */

                /* update block count */
                totwrt -= nwrt;
                blkno += nwrt;
                va = (char *)va + sectorsize * nwrt;
        }
        rddoingadump = 0;
        return (0);
}