BSD 4_1c_2 development
authorCSRG <csrg@ucbvax.Berkeley.EDU>
Fri, 17 Dec 1982 05:10:21 +0000 (21:10 -0800)
committerCSRG <csrg@ucbvax.Berkeley.EDU>
Fri, 17 Dec 1982 05:10:21 +0000 (21:10 -0800)
Work on file a/sys/vaxmba/ht.c
Work on file a/sys/vaxmba/mt.c

Synthesized-from: CSRG/cd1/4.1c.2

a/sys/vaxmba/ht.c [new file with mode: 0644]
a/sys/vaxmba/mt.c [new file with mode: 0644]

diff --git a/a/sys/vaxmba/ht.c b/a/sys/vaxmba/ht.c
new file mode 100644 (file)
index 0000000..f8202fe
--- /dev/null
@@ -0,0 +1,599 @@
+/*     ht.c    4.35    82/12/17        */
+
+#include "tu.h"
+#if NHT > 0
+/*
+ * TM03/TU?? tape driver
+ *
+ * TODO:
+ *     cleanup messages on errors
+ *     test ioctl's
+ *     see how many rewind interrups we get if we kick when not at BOT
+ *     fixup rle error on block tape code
+ */
+#include "../machine/pte.h"
+
+#include "../h/param.h"
+#include "../h/systm.h"
+#include "../h/buf.h"
+#include "../h/conf.h"
+#include "../h/dir.h"
+#include "../h/file.h"
+#include "../h/user.h"
+#include "../h/map.h"
+#include "../h/ioctl.h"
+#include "../h/mtio.h"
+#include "../h/cmap.h"
+#include "../h/uio.h"
+
+#include "../vax/cpu.h"
+#include "../vaxmba/mbareg.h"
+#include "../vaxmba/mbavar.h"
+#include "../vaxmba/htreg.h"
+
+struct buf     rhtbuf[NHT];
+struct buf     chtbuf[NHT];
+
+short  httypes[] =
+       { MBDT_TM03, MBDT_TE16, MBDT_TU45, MBDT_TU77, 0 };
+struct mba_device *htinfo[NHT];
+int    htattach(), htslave(), htustart(), htndtint(), htdtint();
+struct mba_driver htdriver =
+    { htattach, htslave, htustart, 0, htdtint, htndtint,
+      httypes, "ht", "tu", htinfo };
+
+#define MASKREG(r)     ((r) & 0xffff)
+
+/* bits in minor device */
+#define        TUUNIT(dev)     (minor(dev)&03)
+#define        H_NOREWIND      04
+#define        H_1600BPI       08
+
+#define HTUNIT(dev)    (tutoht[TUUNIT(dev)])
+
+#define        INF     (daddr_t)1000000L       /* a block number that wont exist */
+
+struct tu_softc {
+       char    sc_openf;
+       char    sc_flags;
+       daddr_t sc_blkno;
+       daddr_t sc_nxrec;
+       u_short sc_erreg;
+       u_short sc_dsreg;
+       short   sc_resid;
+       short   sc_dens;
+       struct  mba_device *sc_mi;
+       int     sc_slave;
+} tu_softc[NTU];
+short  tutoht[NTU];
+
+/*
+ * Bits for sc_flags.
+ */
+#define        H_WRITTEN 1     /* last operation was a write */
+#define H_ERASED  2    /* last write retry was an erase gap */
+#define H_REWIND  4    /* last unit start was a rewind */
+
+char   hter_bits[] = HTER_BITS;
+char   htds_bits[] = HTDS_BITS;
+
+/*ARGSUSED*/
+htattach(mi)
+       struct mba_device *mi;
+{
+
+}
+
+htslave(mi, ms, sn)
+       struct mba_device *mi;
+       struct mba_slave *ms;
+       int sn;
+{
+       register struct tu_softc *sc = &tu_softc[ms->ms_unit];
+       register struct htdevice *htaddr = (struct htdevice *)mi->mi_drv;
+
+       htaddr->httc = sn;
+       if (htaddr->htdt & HTDT_SPR) {
+               sc->sc_mi = mi;
+               sc->sc_slave = sn;
+               tutoht[ms->ms_unit] = mi->mi_unit;
+               return (1);
+       } else
+               return (0);
+}
+
+htopen(dev, flag)
+       dev_t dev;
+       int flag;
+{
+       register int tuunit;
+       register struct mba_device *mi;
+       register struct tu_softc *sc;
+       int olddens, dens;
+
+       tuunit = TUUNIT(dev);
+       if (tuunit >= NTU || (sc = &tu_softc[tuunit])->sc_openf ||
+           (mi = htinfo[HTUNIT(dev)]) == 0 || mi->mi_alive == 0)
+               return (ENXIO);
+       olddens = sc->sc_dens;
+       dens = sc->sc_dens =
+           ((minor(dev)&H_1600BPI)?HTTC_1600BPI:HTTC_800BPI)|
+               HTTC_PDP11|sc->sc_slave;
+       htcommand(dev, HT_SENSE, 1);
+       sc->sc_dens = olddens;
+       if ((sc->sc_dsreg & HTDS_MOL) == 0) {
+               uprintf("tu%d: not online\n", tuunit);
+               return (EIO);
+       }
+       if ((flag&FWRITE) && (sc->sc_dsreg&HTDS_WRL)) {
+               uprintf("tu%d: no write ring\n", tuunit);
+               return (EIO);
+       }
+       if ((sc->sc_dsreg & HTDS_BOT) == 0 && (flag&FWRITE) &&
+           dens != sc->sc_dens) {
+               uprintf("tu%d: can't change density in mid-tape\n", tuunit);
+               return (EIO);
+       }
+       sc->sc_openf = 1;
+       sc->sc_blkno = (daddr_t)0;
+       sc->sc_nxrec = INF;
+       sc->sc_flags = 0;
+       sc->sc_dens = dens;
+       return (0);
+}
+
+htclose(dev, flag)
+       register dev_t dev;
+       register flag;
+{
+       register struct tu_softc *sc = &tu_softc[TUUNIT(dev)];
+
+       if (flag == FWRITE || ((flag&FWRITE) && (sc->sc_flags&H_WRITTEN))) {
+               htcommand(dev, HT_WEOF, 1);
+               htcommand(dev, HT_WEOF, 1);
+               htcommand(dev, HT_SREV, 1);
+       }
+       if ((minor(dev)&H_NOREWIND) == 0)
+               htcommand(dev, HT_REW, 0);
+       sc->sc_openf = 0;
+}
+
+htcommand(dev, com, count)
+       dev_t dev;
+       int com, count;
+{
+       register struct buf *bp;
+       register int s;
+
+       bp = &chtbuf[HTUNIT(dev)];
+       s = spl5();
+       while (bp->b_flags&B_BUSY) {
+               if(bp->b_repcnt == 0 && (bp->b_flags&B_DONE))
+                       break;
+               bp->b_flags |= B_WANTED;
+               sleep((caddr_t)bp, PRIBIO);
+       }
+       bp->b_flags = B_BUSY|B_READ;
+       splx(s);
+       bp->b_dev = dev;
+       bp->b_command = com;
+       bp->b_repcnt = count;
+       bp->b_blkno = 0;
+       htstrategy(bp);
+       if (count == 0)
+               return;
+       iowait(bp);
+       if (bp->b_flags&B_WANTED)
+               wakeup((caddr_t)bp);
+       bp->b_flags &= B_ERROR;
+}
+
+htstrategy(bp)
+       register struct buf *bp;
+{
+       register struct mba_device *mi = htinfo[HTUNIT(bp->b_dev)];
+       register struct buf *dp;
+       register int s;
+
+       bp->av_forw = NULL;
+       dp = &mi->mi_tab;
+       s = spl5();
+       if (dp->b_actf == NULL)
+               dp->b_actf = bp;
+       else
+               dp->b_actl->av_forw = bp;
+       dp->b_actl = bp;
+       if (dp->b_active == 0)
+               mbustart(mi);
+       splx(s);
+}
+
+htustart(mi)
+       register struct mba_device *mi;
+{
+       register struct htdevice *htaddr =
+           (struct htdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct tu_softc *sc = &tu_softc[TUUNIT(bp->b_dev)];
+       daddr_t blkno;
+
+       htaddr->httc = sc->sc_dens;
+       if (bp == &chtbuf[HTUNIT(bp->b_dev)] && bp->b_command == HT_SENSE) {
+               htaddr->htcs1 = HT_SENSE|HT_GO;
+               mbclrattn(mi);
+       }
+       sc->sc_dsreg = htaddr->htds;
+       sc->sc_erreg = htaddr->hter;
+       sc->sc_resid = htaddr->htfc;
+       sc->sc_flags &= ~(H_WRITTEN|H_REWIND);
+       if ((htaddr->htdt & HTDT_SPR) == 0 || (htaddr->htds & HTDS_MOL) == 0)
+               if (sc->sc_openf > 0)
+                       sc->sc_openf = -1;
+       if (sc->sc_openf < 0) {
+               bp->b_flags |= B_ERROR;
+               return (MBU_NEXT);
+       }
+       if (bp != &chtbuf[HTUNIT(bp->b_dev)]) {
+               if (bdbtofsb(bp->b_blkno) > sc->sc_nxrec) {
+                       bp->b_flags |= B_ERROR;
+                       bp->b_error = ENXIO;
+                       return (MBU_NEXT);
+               }
+               if (bdbtofsb(bp->b_blkno) == sc->sc_nxrec &&
+                   bp->b_flags&B_READ) {
+                       bp->b_resid = bp->b_bcount;
+                       clrbuf(bp);
+                       return (MBU_NEXT);
+               }
+               if ((bp->b_flags&B_READ)==0)
+                       sc->sc_nxrec = bdbtofsb(bp->b_blkno) + 1;
+       } else {
+               if (bp->b_command == HT_SENSE)
+                       return (MBU_NEXT);
+               if (bp->b_command == HT_REW)
+                       sc->sc_flags |= H_REWIND;
+               else
+                       htaddr->htfc = -bp->b_bcount;
+               htaddr->htcs1 = bp->b_command|HT_GO;
+               return (MBU_STARTED);
+       }
+       if ((blkno = sc->sc_blkno) == bdbtofsb(bp->b_blkno)) {
+               htaddr->htfc = -bp->b_bcount;
+               if ((bp->b_flags&B_READ) == 0) {
+                       if (mi->mi_tab.b_errcnt) {
+                               if ((sc->sc_flags & H_ERASED) == 0) {
+                                       sc->sc_flags |= H_ERASED;
+                                       htaddr->htcs1 = HT_ERASE | HT_GO;
+                                       return (MBU_STARTED);
+                               }
+                               sc->sc_flags &= ~H_ERASED;
+                       }
+                       if (htaddr->htds & HTDS_EOT) {
+                               bp->b_resid = bp->b_bcount;
+                               bp->b_flags |= B_ERROR;
+                               return (MBU_NEXT);
+                       }
+               }
+               return (MBU_DODATA);
+       }
+       if (blkno < bdbtofsb(bp->b_blkno)) {
+               htaddr->htfc = blkno - bdbtofsb(bp->b_blkno);
+               htaddr->htcs1 = HT_SFORW|HT_GO;
+       } else {
+               htaddr->htfc = bdbtofsb(bp->b_blkno) - blkno;
+               htaddr->htcs1 = HT_SREV|HT_GO;
+       }
+       return (MBU_STARTED);
+}
+
+htdtint(mi, mbsr)
+       register struct mba_device *mi;
+       int mbsr;
+{
+       register struct htdevice *htaddr = (struct htdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct tu_softc *sc;
+       int ds, er, mbs;
+
+       sc = &tu_softc[TUUNIT(bp->b_dev)];
+       ds = sc->sc_dsreg = MASKREG(htaddr->htds);
+       er = sc->sc_erreg = MASKREG(htaddr->hter);
+       sc->sc_resid = MASKREG(htaddr->htfc);
+       mbs = mbsr;
+       sc->sc_blkno++;
+       if((bp->b_flags & B_READ) == 0)
+               sc->sc_flags |= H_WRITTEN;
+       if ((ds&(HTDS_ERR|HTDS_MOL)) != HTDS_MOL || mbs & MBSR_EBITS) {
+               htaddr->htcs1 = HT_DCLR|HT_GO;
+               mbclrattn(mi);
+               if (bp == &rhtbuf[HTUNIT(bp->b_dev)]) {
+                       er &= ~HTER_FCE;
+                       mbs &= ~(MBSR_DTABT|MBSR_MBEXC);
+               }
+               if (bp->b_flags & B_READ && ds & HTDS_PES)
+                       er &= ~(HTER_CSITM|HTER_CORCRC);
+               if (er&HTER_HARD || mbs&MBSR_EBITS || (ds&HTDS_MOL) == 0 ||
+                   er && ++mi->mi_tab.b_errcnt >= 7) {
+                       if ((ds & HTDS_MOL) == 0 && sc->sc_openf > 0)
+                               sc->sc_openf = -1;
+                       if ((er&HTER_HARD) == HTER_FCE &&
+                           (mbs&MBSR_EBITS) == (MBSR_DTABT|MBSR_MBEXC) &&
+                           (ds&HTDS_MOL))
+                               goto noprint;
+                       printf("tu%d: hard error bn%d mbsr=%b er=%b ds=%b\n",
+                           TUUNIT(bp->b_dev), bp->b_blkno,
+                           mbsr, mbsr_bits,
+                           sc->sc_erreg, hter_bits,
+                           sc->sc_dsreg, htds_bits);
+noprint:
+                       bp->b_flags |= B_ERROR;
+                       return (MBD_DONE);
+               }
+               if (er)
+                       return (MBD_RETRY);
+       }
+       bp->b_resid = 0;
+       if (bp->b_flags & B_READ)
+               if (ds&HTDS_TM) {               /* must be a read, right? */
+                       bp->b_resid = bp->b_bcount;
+                       sc->sc_nxrec = bdbtofsb(bp->b_blkno);
+               } else if(bp->b_bcount > MASKREG(htaddr->htfc))
+                       bp->b_resid = bp->b_bcount - MASKREG(htaddr->htfc);
+       return (MBD_DONE);
+}
+
+htndtint(mi)
+       register struct mba_device *mi;
+{
+       register struct htdevice *htaddr = (struct htdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct tu_softc *sc;
+       int er, ds, fc;
+
+       ds = MASKREG(htaddr->htds);
+       er = MASKREG(htaddr->hter);
+       fc = MASKREG(htaddr->htfc);
+       if (er) {
+               htaddr->htcs1 = HT_DCLR|HT_GO;
+               mbclrattn(mi);
+       }
+       if (bp == 0)
+               return (MBN_SKIP);
+       sc = &tu_softc[TUUNIT(bp->b_dev)];
+       sc->sc_dsreg = ds;
+       sc->sc_erreg = er;
+       sc->sc_resid = fc;
+       if (bp == &chtbuf[HTUNIT(bp->b_dev)]) {
+               switch (bp->b_command) {
+               case HT_REWOFFL:
+                       /* offline is on purpose; don't do anything special */
+                       ds |= HTDS_MOL; 
+                       break;
+               case HT_SREV:
+                       /* if backspace file hit bot, its not an error */
+                       if (er == (HTER_NEF|HTER_FCE) && ds&HTDS_BOT &&
+                           bp->b_repcnt == INF)
+                               er &= ~HTER_NEF;
+                       break;
+               }
+               er &= ~HTER_FCE;
+               if (er == 0)
+                       ds &= ~HTDS_ERR;
+       }
+       if ((ds & (HTDS_ERR|HTDS_MOL)) != HTDS_MOL) {
+               if ((ds & HTDS_MOL) == 0 && sc->sc_openf > 0)
+                       sc->sc_openf = -1;
+               printf("tu%d: hard error bn%d er=%b ds=%b\n",
+                   TUUNIT(bp->b_dev), bp->b_blkno,
+                   sc->sc_erreg, hter_bits, sc->sc_dsreg, htds_bits);
+               bp->b_flags |= B_ERROR;
+               return (MBN_DONE);
+       }
+       if (bp == &chtbuf[HTUNIT(bp->b_dev)]) {
+               if (sc->sc_flags & H_REWIND)
+                       return (ds & HTDS_BOT ? MBN_DONE : MBN_RETRY);
+               bp->b_resid = -sc->sc_resid;
+               return (MBN_DONE);
+       }
+       if (ds & HTDS_TM)
+               if (sc->sc_blkno > bdbtofsb(bp->b_blkno)) {
+                       sc->sc_nxrec = bdbtofsb(bp->b_blkno) - fc;
+                       sc->sc_blkno = sc->sc_nxrec;
+               } else {
+                       sc->sc_blkno = bdbtofsb(bp->b_blkno) + fc;
+                       sc->sc_nxrec = sc->sc_blkno - 1;
+               }
+       else
+               sc->sc_blkno = bdbtofsb(bp->b_blkno);
+       return (MBN_RETRY);
+}
+
+htread(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       int errno;
+
+       errno = htphys(dev, uio);
+       if (errno)
+               return (errno);
+       return (physio(htstrategy, &rhtbuf[HTUNIT(dev)], dev, B_READ, minphys, uio));
+}
+
+htwrite(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       int errno;
+
+       errno = htphys(dev, uio);
+       if (errno)
+               return (errno);
+       return (physio(htstrategy, &rhtbuf[HTUNIT(dev)], dev, B_WRITE, minphys, uio));
+}
+
+htphys(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       register int htunit;
+/*###439 [lint] htphys arg. 2 used inconsistently ht.c(439) :: ht.c(430)%%%*/
+       register struct tu_softc *sc;
+       register struct mba_device *mi;
+       daddr_t a;
+
+       htunit = HTUNIT(dev);
+       if (htunit >= NHT || (mi = htinfo[htunit]) == 0 || mi->mi_alive == 0)
+               return (ENXIO);
+       a = uio->uio_offset >> 9;
+       sc = &tu_softc[TUUNIT(dev)];
+       sc->sc_blkno = bdbtofsb(a);
+       sc->sc_nxrec = bdbtofsb(a)+1;
+       return (0);
+}
+
+/*ARGSUSED*/
+htioctl(dev, cmd, data, flag)
+       dev_t dev;
+       int cmd;
+       caddr_t data;
+       int flag;
+{
+       register struct tu_softc *sc = &tu_softc[TUUNIT(dev)];
+       register struct buf *bp = &chtbuf[HTUNIT(dev)];
+       register callcount;
+       int fcount;
+       struct mtop *mtop;
+       struct mtget *mtget;
+       /* we depend of the values and order of the MT codes here */
+       static htops[] =
+   {HT_WEOF,HT_SFORW,HT_SREV,HT_SFORW,HT_SREV,HT_REW,HT_REWOFFL,HT_SENSE};
+
+       switch (cmd) {
+
+       case MTIOCTOP:  /* tape operation */
+               mtop = (struct mtop *)data;
+               switch (mtop->mt_op) {
+
+               case MTWEOF:
+                       callcount = mtop->mt_count;
+                       fcount = 1;
+                       break;
+
+               case MTFSF: case MTBSF:
+                       callcount = mtop->mt_count;
+                       fcount = INF;
+                       break;
+
+               case MTFSR: case MTBSR:
+                       callcount = 1;
+                       fcount = mtop->mt_count;
+                       break;
+
+               case MTREW: case MTOFFL:
+                       callcount = 1;
+                       fcount = 1;
+                       break;
+
+               default:
+                       return (ENXIO);
+               }
+               if (callcount <= 0 || fcount <= 0)
+                       return (EINVAL);
+               while (--callcount >= 0) {
+                       htcommand(dev, htops[mtop->mt_op], fcount);
+                       if ((mtop->mt_op == MTFSR || mtop->mt_op == MTBSR) &&
+                           bp->b_resid)
+                               return (EIO);
+                       if ((bp->b_flags&B_ERROR) || sc->sc_dsreg&HTDS_BOT)
+                               break;
+               }
+               return (geterror(bp));  
+
+       case MTIOCGET:
+               mtget = (struct mtget *)data;
+               mtget->mt_dsreg = sc->sc_dsreg;
+               mtget->mt_erreg = sc->sc_erreg;
+               mtget->mt_resid = sc->sc_resid;
+               mtget->mt_type = MT_ISHT;
+               break;
+
+       default:
+               return (ENXIO);
+       }
+       return (0);
+}
+
+#define        DBSIZE  20
+
+htdump()
+{
+       register struct mba_device *mi;
+       register struct mba_regs *mp;
+       register struct htdevice *htaddr;
+       int blk, num;
+       int start;
+
+       start = 0;
+       num = maxfree;
+#define        phys(a,b)               ((b)((int)(a)&0x7fffffff))
+       if (htinfo[0] == 0)
+               return (ENXIO);
+       mi = phys(htinfo[0], struct mba_device *);
+       mp = phys(mi->mi_hd, struct mba_hd *)->mh_physmba;
+       mp->mba_cr = MBCR_IE;
+       htaddr = (struct htdevice *)&mp->mba_drv[mi->mi_drive];
+       htaddr->httc = HTTC_PDP11|HTTC_1600BPI;
+       htaddr->htcs1 = HT_DCLR|HT_GO;
+       while (num > 0) {
+               blk = num > DBSIZE ? DBSIZE : num;
+               htdwrite(start, blk, htaddr, mp);
+               start += blk;
+               num -= blk;
+       }
+       hteof(htaddr);
+       hteof(htaddr);
+       htwait(htaddr);
+       if (htaddr->htds&HTDS_ERR)
+               return (EIO);
+       htaddr->htcs1 = HT_REW|HT_GO;
+       return (0);
+}
+
+htdwrite(dbuf, num, htaddr, mp)
+       register dbuf, num;
+       register struct htdevice *htaddr;
+       struct mba_regs *mp;
+{
+       register struct pte *io;
+       register int i;
+
+       htwait(htaddr);
+       io = mp->mba_map;
+       for (i = 0; i < num; i++)
+               *(int *)io++ = dbuf++ | PG_V;
+       htaddr->htfc = -(num*NBPG);
+       mp->mba_sr = -1;
+       mp->mba_bcr = -(num*NBPG);
+       mp->mba_var = 0;
+       htaddr->htcs1 = HT_WCOM|HT_GO;
+}
+
+htwait(htaddr)
+       struct htdevice *htaddr;
+{
+       register s;
+
+       do
+               s = htaddr->htds;
+       while ((s & HTDS_DRY) == 0);
+}
+
+hteof(htaddr)
+       struct htdevice *htaddr;
+{
+
+       htwait(htaddr);
+       htaddr->htcs1 = HT_WEOF|HT_GO;
+}
+#endif
diff --git a/a/sys/vaxmba/mt.c b/a/sys/vaxmba/mt.c
new file mode 100644 (file)
index 0000000..2ea9546
--- /dev/null
@@ -0,0 +1,655 @@
+/*     mt.c    4.15    82/12/17        */
+
+#include "mu.h"
+#if NMT > 0
+/*
+ * TM78/TU78 tape driver
+ *
+ *     Behavior in complex error situations is uncertain...
+ *
+ * TODO:
+ *     test error recovery
+ *     add odd byte count kludge from VMS driver
+ *     write dump routine
+ */
+#include "../machine/pte.h"
+
+#include "../h/param.h"
+#include "../h/systm.h"
+#include "../h/buf.h"
+#include "../h/conf.h"
+#include "../h/dir.h"
+#include "../h/file.h"
+#include "../h/user.h"
+#include "../h/map.h"
+#include "../h/ioctl.h"
+#include "../h/mtio.h"
+#include "../h/cmap.h"
+#include "../h/uio.h"
+
+#include "../vax/cpu.h"
+#include "../vaxmba/mbareg.h"
+#include "../vaxmba/mbavar.h"
+#include "../vaxmba/mtreg.h"
+
+struct buf     rmtbuf[NMT];
+struct buf     cmtbuf[NMT];
+
+short  mttypes[] =
+       { MBDT_TU78, 0 };
+struct mba_device *mtinfo[NMT];
+int    mtattach(), mtslave(), mtustart(), mtstart(), mtndtint(), mtdtint();
+struct mba_driver mtdriver =
+    { mtattach, mtslave, mtustart, mtstart, mtdtint, mtndtint,
+      mttypes, "mt", "mu", mtinfo };
+
+#define MASKREG(r)     ((r) & 0xffff)
+
+/* bits in minor device */
+#define        MUUNIT(dev)     (minor(dev)&03)
+#define        H_NOREWIND      04
+#define        H_6250BPI       08
+
+#define MTUNIT(dev)    (mutomt[MUUNIT(dev)])
+
+#define        INF     (daddr_t)1000000L       /* a block number that wont exist */
+
+struct mu_softc {
+       char    sc_openf;
+       char    sc_flags;
+       daddr_t sc_blkno;
+       daddr_t sc_nxrec;
+       u_short sc_erreg;
+       u_short sc_dsreg;
+       short   sc_resid;
+       short   sc_dens;
+       struct  mba_device *sc_mi;
+       int     sc_slave;
+} mu_softc[NMU];
+short  mutomt[NMU];
+
+/*
+ * Bits for sc_flags.
+ */
+#define        H_WRITTEN 1     /* last operation was a write */
+
+char   mtds_bits[] = MTDS_BITS;
+
+/*ARGSUSED*/
+mtattach(mi)
+       struct mba_device *mi;
+{
+
+}
+
+mtslave(mi, ms, sn)
+       struct mba_device *mi;
+       struct mba_slave *ms;
+       int sn;
+{
+       register struct mu_softc *sc = &mu_softc[ms->ms_unit];
+       register struct mtdevice *mtaddr = (struct mtdevice *)mi->mi_drv;
+       int s = spl7(), rtn = 0;
+
+       mtaddr->mtas = -1;
+       mtaddr->mtncs[sn] = MT_SENSE|MT_GO;
+       while (mtaddr->mtas == 0)
+               ;
+       if ((mtaddr->mtner & MTER_INTCODE) == MTER_DONE &&
+           (mtaddr->mtds & MTDS_PRES)) {
+               sc->sc_mi = mi;
+               sc->sc_slave = sn;
+               mutomt[ms->ms_unit] = mi->mi_unit;
+               rtn = 1;
+       }
+       mtaddr->mtas = mtaddr->mtas;
+       splx(s);
+       return (rtn);
+}
+
+mtopen(dev, flag)
+       dev_t dev;
+       int flag;
+{
+       register int muunit;
+       register struct mba_device *mi;
+       register struct mu_softc *sc;
+       int olddens, dens;
+
+       muunit = MUUNIT(dev);
+       if (muunit >= NMU || (sc = &mu_softc[muunit])->sc_openf ||
+           (mi = mtinfo[MTUNIT(dev)]) == 0 || mi->mi_alive == 0)
+               return (ENXIO);
+       olddens = sc->sc_dens;
+       dens = sc->sc_dens = (minor(dev)&H_6250BPI) ? MT_GCR : 0;
+       mtcommand(dev, MT_SENSE, 1);
+       sc->sc_dens = olddens;
+       if ((sc->sc_dsreg & MTDS_ONL) == 0) {
+               uprintf("mu%d: not online\n", muunit);
+               return (EIO);
+       }
+       if ((flag&FWRITE) && (sc->sc_dsreg&MTDS_FPT)) {
+               uprintf("mu%d: no write ring\n", muunit);
+               return (EIO);
+       }
+       if ((sc->sc_dsreg & MTDS_BOT) == 0 && (flag&FWRITE) &&
+           dens != sc->sc_dens) {
+               uprintf("mu%d: can't change density in mid-tape\n", muunit);
+               return (EIO);
+       }
+       sc->sc_openf = 1;
+       sc->sc_blkno = (daddr_t)0;
+       sc->sc_nxrec = INF;
+       sc->sc_flags = 0;
+       sc->sc_dens = dens;
+       return (0);
+}
+
+mtclose(dev, flag)
+       register dev_t dev;
+       register flag;
+{
+       register struct mu_softc *sc = &mu_softc[MUUNIT(dev)];
+
+       if (flag == FWRITE || ((flag&FWRITE) && (sc->sc_flags&H_WRITTEN)))
+               mtcommand(dev, MT_CLS|sc->sc_dens, 1);
+       if ((minor(dev)&H_NOREWIND) == 0)
+               mtcommand(dev, MT_REW, 0);
+       sc->sc_openf = 0;
+}
+
+mtcommand(dev, com, count)
+       dev_t dev;
+       int com, count;
+{
+       register struct buf *bp;
+       register int s;
+
+       bp = &cmtbuf[MTUNIT(dev)];
+       s = spl5();
+       while (bp->b_flags&B_BUSY) {
+               if(bp->b_repcnt == 0 && (bp->b_flags&B_DONE))
+                       break;
+               bp->b_flags |= B_WANTED;
+               sleep((caddr_t)bp, PRIBIO);
+       }
+       bp->b_flags = B_BUSY|B_READ;
+       splx(s);
+       bp->b_dev = dev;
+       bp->b_command = com;
+       bp->b_repcnt = count;
+       bp->b_blkno = 0;
+       mtstrategy(bp);
+       if (count == 0)
+               return;
+       iowait(bp);
+       if (bp->b_flags&B_WANTED)
+               wakeup((caddr_t)bp);
+       bp->b_flags &= B_ERROR;
+}
+
+mtstrategy(bp)
+       register struct buf *bp;
+{
+       register struct mba_device *mi = mtinfo[MTUNIT(bp->b_dev)];
+       register struct buf *dp;
+       register int s;
+
+       bp->av_forw = NULL;
+       dp = &mi->mi_tab;
+       s = spl5();
+       if (dp->b_actf == NULL)
+               dp->b_actf = bp;
+       else
+               dp->b_actl->av_forw = bp;
+       dp->b_actl = bp;
+       if (dp->b_active == 0)
+               mbustart(mi);
+       splx(s);
+}
+
+mtustart(mi)
+       register struct mba_device *mi;
+{
+       register struct mtdevice *mtaddr =
+           (struct mtdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct mu_softc *sc = &mu_softc[MUUNIT(bp->b_dev)];
+       daddr_t blkno;
+
+       sc->sc_flags &= ~H_WRITTEN;
+       if (sc->sc_openf < 0) {
+               bp->b_flags |= B_ERROR;
+               return (MBU_NEXT);
+       }
+       if (bp != &cmtbuf[MTUNIT(bp->b_dev)]) {
+               if (bdbtofsb(bp->b_blkno) > sc->sc_nxrec) {
+                       bp->b_flags |= B_ERROR;
+                       bp->b_error = ENXIO;
+                       return (MBU_NEXT);
+               }
+               if (bdbtofsb(bp->b_blkno) == sc->sc_nxrec &&
+                   bp->b_flags&B_READ) {
+                       bp->b_resid = bp->b_bcount;
+                       clrbuf(bp);
+                       return (MBU_NEXT);
+               }
+               if ((bp->b_flags&B_READ)==0)
+                       sc->sc_nxrec = bdbtofsb(bp->b_blkno) + 1;
+       } else {
+               mtaddr->mtncs[MUUNIT(bp->b_dev)] =
+                       (bp->b_repcnt<<8)|bp->b_command|MT_GO;
+               return (MBU_STARTED);
+       }
+       if ((blkno = sc->sc_blkno) == bdbtofsb(bp->b_blkno)) {
+               if (mi->mi_tab.b_errcnt == 2) {
+                       mtaddr->mtca = MUUNIT(bp->b_dev);
+               } else {
+                       mtaddr->mtbc = bp->b_bcount;
+                       mtaddr->mtca = (1<<2)|MUUNIT(bp->b_dev);
+               }
+               return (MBU_DODATA);
+       }
+       if (blkno < bdbtofsb(bp->b_blkno))
+               mtaddr->mtncs[MUUNIT(bp->b_dev)] =
+                 (min((unsigned)(bdbtofsb(bp->b_blkno) - blkno), 0377) << 8) |
+                       MT_SFORW|MT_GO;
+       else
+               mtaddr->mtncs[MUUNIT(bp->b_dev)] =
+                 (min((unsigned)(blkno - bdbtofsb(bp->b_blkno)), 0377) << 8) |
+                       MT_SREV|MT_GO;
+       return (MBU_STARTED);
+}
+
+mtstart(mi)
+       register struct mba_device *mi;
+{
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct mu_softc *sc = &mu_softc[MUUNIT(bp->b_dev)];
+
+       if (bp->b_flags & B_READ)
+               if (mi->mi_tab.b_errcnt == 2)
+                       return(MT_READREV|MT_GO);
+               else
+                       return(MT_READ|MT_GO);
+       else
+               return(MT_WRITE|sc->sc_dens|MT_GO);
+}
+
+mtdtint(mi, mbsr)
+       register struct mba_device *mi;
+       int mbsr;
+{
+       register struct mtdevice *mtaddr = (struct mtdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct mu_softc *sc;
+
+       /* I'M NOT SURE IF THIS SHOULD ALWAYS BE THE CASE SO FOR NOW... */
+       if ((mtaddr->mtca&3) != MUUNIT(bp->b_dev)) {
+               printf("mt: wrong unit!\n");
+               mtaddr->mtca = MUUNIT(bp->b_dev);
+       }
+       sc = &mu_softc[MUUNIT(bp->b_dev)];
+       sc->sc_erreg = mtaddr->mter;
+       if((bp->b_flags & B_READ) == 0)
+               sc->sc_flags |= H_WRITTEN;
+       switch (sc->sc_erreg & MTER_INTCODE) {
+       case MTER_DONE:
+       case MTER_LONGREC:
+               if (mi->mi_tab.b_errcnt != 2)
+                       sc->sc_blkno++;
+               bp->b_resid = 0;
+               break;
+
+       case MTER_NOTCAP:
+               printf("mu%d: blank tape\n", MUUNIT(bp->b_dev));
+               goto err;
+
+       case MTER_TM:
+       case MTER_EOT:
+               sc->sc_blkno++;
+       err:
+               bp->b_resid = bp->b_bcount;
+               sc->sc_nxrec = bdbtofsb(bp->b_blkno);
+               break;
+
+       case MTER_SHRTREC:
+               sc->sc_blkno++;
+               if (bp != &rmtbuf[MTUNIT(bp->b_dev)])
+                       bp->b_flags |= B_ERROR;
+               if (mi->mi_tab.b_errcnt == 2)
+                       bp->b_bcount = bp->b_resid;     /* restore saved value */
+               bp->b_resid = bp->b_bcount - mtaddr->mtbc;
+               break;
+
+       case MTER_RDOPP:
+               mi->mi_tab.b_errcnt = 2;        /* indicate "read opposite" */
+               bp->b_resid = bp->b_bcount;     /* save it */
+               bp->b_bcount = mtaddr->mtbc;    /* use this instead */
+               return(MBD_RETRY);
+
+       case MTER_RETRY:
+               mi->mi_tab.b_errcnt = 1;        /* indicate simple retry */
+               return(MBD_RETRY);
+
+       case MTER_OFFLINE:
+               if (sc->sc_openf > 0) {
+                       sc->sc_openf = -1;
+                       printf("mu%d: offline\n", MUUNIT(bp->b_dev));
+               }
+               bp->b_flags |= B_ERROR;
+               break;
+
+       case MTER_FPT:
+               printf("mu%d: no write ring\n", MUUNIT(bp->b_dev));
+               bp->b_flags |= B_ERROR;
+               break;
+
+       default:
+               printf("mu%d: hard error bn%d mbsr=%b er=%x ds=%b\n",
+                   MUUNIT(bp->b_dev), bp->b_blkno,
+                   mbsr, mbsr_bits, sc->sc_erreg,
+                   sc->sc_dsreg, mtds_bits);
+               bp->b_flags |= B_ERROR;
+               mtaddr->mtid = MTID_CLR;                /* reset the TM78 */
+               DELAY(250);
+               while ((mtaddr->mtid & MTID_RDY) == 0)  /* wait for it */
+                       ;
+               return (MBD_DONE);
+       }
+       /* CHECK FOR MBA ERROR WHEN NO OTHER ERROR INDICATED? */
+       return (MBD_DONE);
+}
+
+mtndtint(mi)
+       register struct mba_device *mi;
+{
+       register struct mtdevice *mtaddr = (struct mtdevice *)mi->mi_drv;
+       register struct buf *bp = mi->mi_tab.b_actf;
+       register struct mu_softc *sc;
+       int er, fc, unit;
+
+       unit = (mtaddr->mtner >> 8) & 3;
+       er = MASKREG(mtaddr->mtner);
+       /* WILL THIS OCCUR IF ANOTHER DRIVE COMES ONLINE? */
+       if (bp == 0 || unit != MUUNIT(bp->b_dev)) {     /* consistency check */
+               if ((er & MTER_INTCODE) != MTER_ONLINE)
+                       printf("mt: unit %d random interrupt\n", unit);
+               return (MBN_SKIP);
+       }
+       if (bp == 0)
+               return (MBN_SKIP);
+       fc = (mtaddr->mtncs[unit] >> 8) & 0xff;
+       sc = &mu_softc[unit];
+       sc->sc_erreg = er;
+       sc->sc_resid = fc;
+       switch (er & MTER_INTCODE) {
+       case MTER_DONE:
+               if (bp == &cmtbuf[MTUNIT(bp->b_dev)]) {
+       done:
+                       if (bp->b_command == MT_SENSE)
+                               sc->sc_dsreg = MASKREG(mtaddr->mtds);
+                       bp->b_resid = fc;
+                       return (MBN_DONE);
+               }
+               /* this is UGLY!  (but is it correct?) */
+               if ((fc = bdbtofsb(bp->b_blkno) - sc->sc_blkno) < 0)
+                       sc->sc_blkno -= MIN(0377, -fc);
+               else
+                       sc->sc_blkno += MIN(0377, fc);
+               return (MBN_RETRY);
+
+       case MTER_RWDING:
+               return (MBN_SKIP);      /* ignore "rewind started" interrupt */
+
+       case MTER_NOTCAP:
+               printf("mu%d: blank tape\n", MUUNIT(bp->b_dev));
+
+       case MTER_TM:
+       case MTER_EOT:
+       case MTER_LEOT:
+               if (sc->sc_blkno > bdbtofsb(bp->b_blkno)) {
+                       sc->sc_nxrec = bdbtofsb(bp->b_blkno) + fc;
+                       sc->sc_blkno = sc->sc_nxrec;
+               } else {
+                       sc->sc_blkno = bdbtofsb(bp->b_blkno) - fc;
+                       sc->sc_nxrec = sc->sc_blkno - 1;
+               }
+               return (MBN_RETRY);
+
+       case MTER_FPT:
+               printf("mu%d: no write ring\n", MUUNIT(bp->b_dev));
+               bp->b_flags |= B_ERROR;
+               return (MBN_DONE);
+
+       case MTER_OFFLINE:
+               if (sc->sc_openf > 0) {
+                       sc->sc_openf = -1;
+                       printf("mu%d: offline\n", MUUNIT(bp->b_dev));
+               }
+               bp->b_flags |= B_ERROR;
+               return (MBN_DONE);
+
+       case MTER_BOT:
+               if (bp == &cmtbuf[MTUNIT(bp->b_dev)])
+                       goto done;
+               /* FALL THROUGH */
+
+       default:
+               printf("mu%d: hard error bn%d er=%o ds=%b\n",
+                   MUUNIT(bp->b_dev), bp->b_blkno,
+                   sc->sc_erreg, sc->sc_dsreg, mtds_bits);
+               mtaddr->mtid = MTID_CLR;                /* reset the TM78 */
+               DELAY(250);
+               while ((mtaddr->mtid & MTID_RDY) == 0)  /* wait for it */
+                       ;
+               bp->b_flags |= B_ERROR;
+               return (MBN_DONE);
+       }
+       /* NOTREACHED */
+}
+
+mtread(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       int errno;
+
+       errno = mtphys(dev, uio);
+       if (errno)
+               return (errno);
+       return (physio(mtstrategy, &rmtbuf[MTUNIT(dev)], dev, B_READ, minphys, uio));
+}
+
+mtwrite(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       int errno;
+
+       errno = mtphys(dev, uio);
+       if (errno)
+               return (errno);
+       return (physio(mtstrategy, &rmtbuf[MTUNIT(dev)], dev, B_WRITE, minphys, uio));
+}
+
+mtphys(dev, uio)
+       dev_t dev;
+       struct uio *uio;
+{
+       register int mtunit;
+       register struct mu_softc *sc;
+       register struct mba_device *mi;
+       daddr_t a;
+
+       mtunit = MTUNIT(dev);
+       if (mtunit >= NMT || (mi = mtinfo[mtunit]) == 0 || mi->mi_alive == 0)
+               return (ENXIO);
+       a = uio->uio_offset >> 9;
+       sc = &mu_softc[MUUNIT(dev)];
+       sc->sc_blkno = bdbtofsb(a);
+       sc->sc_nxrec = bdbtofsb(a)+1;
+       return (0);
+}
+
+/*ARGSUSED*/
+mtioctl(dev, cmd, data, flag)
+       dev_t dev;
+       int cmd;
+       caddr_t data;
+       int flag;
+{
+       register struct mu_softc *sc = &mu_softc[MUUNIT(dev)];
+       register struct buf *bp = &cmtbuf[MTUNIT(dev)];
+       register callcount;
+       register int op;
+       int fcount;
+       struct mtop *mtop;
+       struct mtget *mtget;
+       /* we depend of the values and order of the MT codes here */
+       static mtops[] =
+       {MT_WTM,MT_SFORWF,MT_SREVF,MT_SFORW,MT_SREV,MT_REW,MT_UNLOAD,MT_SENSE};
+
+       switch (cmd) {
+
+       case MTIOCTOP:  /* tape operation */
+               mtop = (struct mtop *)data;
+               switch (mtop->mt_op) {
+
+               case MTWEOF:
+                       callcount = mtop->mt_count;
+                       fcount = 1;
+                       break;
+
+               case MTFSF: case MTBSF:
+                       callcount = mtop->mt_count;
+                       fcount = 1;
+                       break;
+
+               case MTFSR: case MTBSR:
+                       callcount = 1;
+                       fcount = mtop->mt_count;
+                       break;
+
+               case MTREW: case MTOFFL:
+                       callcount = 1;
+                       fcount = 1;
+                       break;
+
+               default:
+                       return (ENXIO);
+               }
+               if (callcount <= 0 || fcount <= 0)
+                       return (EINVAL);
+               op = mtops[mtop->mt_op];
+               if (op == MT_WTM)
+                       op |= sc->sc_dens;
+               while (--callcount >= 0) {
+                       register int n;
+
+                       do {
+                               n = MIN(fcount, 0xff);
+                               mtcommand(dev, op, n);
+                               fcount -= n;
+                       } while (fcount);
+                       if ((mtop->mt_op == MTFSR || mtop->mt_op == MTBSR) &&
+                           bp->b_resid)
+                               return (EIO);
+                       if (bp->b_flags&B_ERROR)
+                               break;
+               }
+               return (geterror(bp));
+
+       case MTIOCGET:
+               mtget = (struct mtget *)data;
+               mtget->mt_erreg = sc->sc_erreg;
+               mtget->mt_resid = sc->sc_resid;
+               mtcommand(dev, MT_SENSE, 1);    /* update drive status */
+               mtget->mt_dsreg = sc->sc_dsreg;
+               mtget->mt_type = MT_ISMT;
+               break;
+
+       default:
+               return (ENXIO);
+       }
+       return (0);
+}
+
+#define        DBSIZE  20
+
+mtdump()
+{
+       register struct mba_device *mi;
+       register struct mba_regs *mp;
+       int blk, num;
+       int start;
+
+       start = 0;
+       num = maxfree;
+#define        phys(a,b)               ((b)((int)(a)&0x7fffffff))
+       if (mtinfo[0] == 0)
+               return (ENXIO);
+       mi = phys(mtinfo[0], struct mba_device *);
+       mp = phys(mi->mi_hd, struct mba_hd *)->mh_physmba;
+       mp->mba_cr = MBCR_IE;
+#if lint
+       blk = 0; num = blk; start = num; blk = start;
+       return (0);
+#endif
+#ifdef notyet
+       mtaddr = (struct mtdevice *)&mp->mba_drv[mi->mi_drive];
+       mtaddr->mttc = MTTC_PDP11|MTTC_1600BPI;
+       mtaddr->mtcs1 = MT_DCLR|MT_GO;
+       while (num > 0) {
+               blk = num > DBSIZE ? DBSIZE : num;
+               mtdwrite(start, blk, mtaddr, mp);
+               start += blk;
+               num -= blk;
+       }
+       mteof(mtaddr);
+       mteof(mtaddr);
+       mtwait(mtaddr);
+       if (mtaddr->mtds&MTDS_ERR)
+               return (EIO);
+       mtaddr->mtcs1 = MT_REW|MT_GO;
+       return (0);
+}
+
+mtdwrite(dbuf, num, mtaddr, mp)
+       register dbuf, num;
+       register struct mtdevice *mtaddr;
+       struct mba_regs *mp;
+{
+       register struct pte *io;
+       register int i;
+
+       mtwait(mtaddr);
+       io = mp->mba_map;
+       for (i = 0; i < num; i++)
+               *(int *)io++ = dbuf++ | PG_V;
+       mtaddr->mtfc = -(num*NBPG);
+       mp->mba_sr = -1;
+       mp->mba_bcr = -(num*NBPG);
+       mp->mba_var = 0;
+       mtaddr->mtcs1 = MT_WCOM|MT_GO;
+}
+
+mtwait(mtaddr)
+       struct mtdevice *mtaddr;
+{
+       register s;
+
+       do
+               s = mtaddr->mtds;
+       while ((s & MTDS_DRY) == 0);
+}
+
+mteof(mtaddr)
+       struct mtdevice *mtaddr;
+{
+
+       mtwait(mtaddr);
+       mtaddr->mtcs1 = MT_WEOF|MT_GO;
+#endif notyet
+}
+#endif