X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/f86df66c1575304c08a6fd0716bcfdba12f5d593..4a404244ad5a6e8679d302ed44ecc61cac172725:/usr/src/sys/vax/mba/ht.c

diff --git a/usr/src/sys/vax/mba/ht.c b/usr/src/sys/vax/mba/ht.c
index 147ac62d20..7cd25baecc 100644
--- a/usr/src/sys/vax/mba/ht.c
+++ b/usr/src/sys/vax/mba/ht.c
@@ -1,9 +1,16 @@
-/*	ht.c	3.4	%G%	*/
+/*	ht.c	4.22	82/05/12	*/
 
+#include "tu.h"
+#if NHT > 0
 /*
- * TJU16 tape driver
+ * 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 "../h/param.h"
 #include "../h/systm.h"
 #include "../h/buf.h"
@@ -12,339 +19,577 @@
 #include "../h/file.h"
 #include "../h/user.h"
 #include "../h/map.h"
-#include "../h/mba.h"
+#include "../h/pte.h"
+#include "../h/mbareg.h"
+#include "../h/mbavar.h"
+#include "../h/mtio.h"
+#include "../h/ioctl.h"
+#include "../h/cmap.h"
+#include "../h/cpu.h"
+
+#include "../h/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 */
 
-struct	device
+char	hter_bits[] = HTER_BITS;
+char	htds_bits[] = HTDS_BITS;
+
+/*ARGSUSED*/
+htattach(mi)
+	struct mba_device *mi;
 {
-	int	htcs1;
-	int	htds;
-	int	hter;
-	int	htmr;
-	int	htas;
-	int	htfc;
-	int	htdt;
-	int	htck;
-	int	htsn;
-	int	httc;
-};
-
-struct	buf	httab;
-struct	buf	rhtbuf;
-struct	buf	chtbuf;
-
-#define	NUNIT	1
-#define	BUNIT	2
-#define	INF	1000000
-
-char	h_openf[NUNIT];
-daddr_t	h_blkno[NUNIT];
-char	h_flags[NUNIT];
-daddr_t	h_nxrec[NUNIT];
-
-#define	HTADDR	((struct device *)(MBA1 + MBA_ERB))
-
-#define	GO	01
-#define	WCOM	060
-#define	RCOM	070
-#define	NOP	0
-#define	WEOF	026
-#define	SFORW	030
-#define	SREV	032
-#define	ERASE	024
-#define	REW	06
-#define	DCLR	010
-#define	P800	01700		/* 800 + pdp11 mode */
-#define	P1600	02300		/* 1600 + pdp11 mode */
-#define	IENABLE	0100
-#define	RDY	0200
-#define	TM	04
-#define	DRY	0200
-#define	EOT	02000
-#define	CS	02000
-#define	COR	0100000
-#define	PES	040
-#define	WRL	04000
-#define	MOL	010000
-#define	ERR	040000
-#define	FCE	01000
-#define	TRE	040000
-#define	HARD	064023	/* UNS|OPI|NEF|FMT|RMR|ILR|ILF */
-
-#define	SIO	1
-#define	SSFOR	2
-#define	SSREV	3
-#define	SRETRY	4
-#define	SCOM	5
-#define	SOK	6
-
-#define	H_WRITTEN 1
 
-htopen(dev, flag)
+}
+
+htslave(mi, ms)
+	struct mba_device *mi;
+	struct mba_slave *ms;
 {
-	register unit, ds;
+	register struct tu_softc *sc = &tu_softc[ms->ms_unit];
+	register struct htdevice *htaddr = (struct htdevice *)mi->mi_drv;
+
+	htaddr->httc = ms->ms_slave;
+	if (htaddr->htdt & HTDT_SPR) {
+		sc->sc_mi = mi;
+		sc->sc_slave = ms->ms_slave;
+		tutoht[ms->ms_unit] = mi->mi_unit;
+		return (1);
+	} else
+		return (0);
+}
 
-	httab.b_flags |= B_TAPE;
-	unit = minor(dev) & 03;
-	if (unit >= NUNIT || h_openf[unit]) {
+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) {
 		u.u_error = ENXIO;
 		return;
 	}
-	h_blkno[unit] = 0;
-	h_nxrec[unit] = INF;
-	h_flags[unit] = 0;
-	ds = hcommand(dev, NOP);
-	if ((ds&MOL)==0 || (flag && (ds&WRL)))
-		u.u_error = ENXIO;
-	if (u.u_error==0)
-		h_openf[unit]++;
+	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);
+		u.u_error = EIO;
+		return;
+	}
+	if ((flag&FWRITE) && (sc->sc_dsreg&HTDS_WRL)) {
+		uprintf("tu%d: no write ring\n", tuunit);
+		u.u_error = EIO;
+		return;
+	}
+	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);
+		u.u_error = EIO;
+		return;
+	}
+	sc->sc_openf = 1;
+	sc->sc_blkno = (daddr_t)0;
+	sc->sc_nxrec = INF;
+	sc->sc_flags = 0;
+	sc->sc_dens = dens;
 }
 
 htclose(dev, flag)
+	register dev_t dev;
+	register flag;
 {
-	register int unit;
+	register struct tu_softc *sc = &tu_softc[TUUNIT(dev)];
 
-	unit = minor(dev) & 03;
-	if (flag == FWRITE || ((flag&FWRITE) && (h_flags[unit]&H_WRITTEN))) {
-		(void) hcommand(dev, WEOF);
-		(void) hcommand(dev, WEOF);
-		(void) hcommand(dev, SREV);
+	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)&4) == 0) /* no 4 -> rewind */
-		(void) hcommand(dev, REW);
-	h_openf[unit] = 0;
+	if ((minor(dev)&H_NOREWIND) == 0)
+		htcommand(dev, HT_REW, 0);
+	sc->sc_openf = 0;
 }
 
-hcommand(dev, com)
+htcommand(dev, com, count)
+	dev_t dev;
+	int com, count;
 {
 	register struct buf *bp;
+	register int s;
 
-	bp = &chtbuf;
-	(void) spl5();
-	while(bp->b_flags&B_BUSY) {
+	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);
 	}
-	(void) spl0();
+	bp->b_flags = B_BUSY|B_READ;
+	splx(s);
 	bp->b_dev = dev;
-	bp->b_resid = com;
+	bp->b_command = com;
+	bp->b_repcnt = count;
 	bp->b_blkno = 0;
-	bp->b_flags = B_BUSY|B_READ;
 	htstrategy(bp);
+	if (count == 0)
+		return;
 	iowait(bp);
-	if(bp->b_flags&B_WANTED)
+	if (bp->b_flags&B_WANTED)
 		wakeup((caddr_t)bp);
-	bp->b_flags = 0;
-	return(bp->b_resid);
+	bp->b_flags &= B_ERROR;
 }
 
 htstrategy(bp)
-register struct buf *bp;
+	register struct buf *bp;
 {
-	register daddr_t *p;
+	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);
+}
 
-	if(bp != &chtbuf) {
-		p = &h_nxrec[minor(bp->b_dev)&03];
-		if(dbtofsb(bp->b_blkno) > *p) {
+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 (dbtofsb(bp->b_blkno) > sc->sc_nxrec) {
 			bp->b_flags |= B_ERROR;
 			bp->b_error = ENXIO;
-			iodone(bp);
-			return;
+			return (MBU_NEXT);
 		}
-		if(dbtofsb(bp->b_blkno) == *p && bp->b_flags&B_READ) {
+		if (dbtofsb(bp->b_blkno) == sc->sc_nxrec &&
+		    bp->b_flags&B_READ) {
 			bp->b_resid = bp->b_bcount;
 			clrbuf(bp);
-			iodone(bp);
-			return;
+			return (MBU_NEXT);
 		}
-		if ((bp->b_flags&B_READ)==0) {
-			*p = dbtofsb(bp->b_blkno) + 1;
-			h_flags[minor(bp->b_dev)&03] |=  H_WRITTEN;
+		if ((bp->b_flags&B_READ)==0)
+			sc->sc_nxrec = dbtofsb(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) == dbtofsb(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);
 	}
-	bp->av_forw = NULL;
-	(void) spl5();
-	if (httab.b_actf == NULL)
-		httab.b_actf = bp;
-	else
-		httab.b_actl->av_forw = bp;
-	httab.b_actl = bp;
-	if (httab.b_active==0)
-		htstart();
-	(void) spl0();
+	if (blkno < dbtofsb(bp->b_blkno)) {
+		htaddr->htfc = blkno - dbtofsb(bp->b_blkno);
+		htaddr->htcs1 = HT_SFORW|HT_GO;
+	} else {
+		htaddr->htfc = dbtofsb(bp->b_blkno) - blkno;
+		htaddr->htcs1 = HT_SREV|HT_GO;
+	}
+	return (MBU_STARTED);
 }
 
-htstart()
+htdtint(mi, mbsr)
+	register struct mba_device *mi;
+	int mbsr;
 {
-	register struct buf *bp;
-	register unit, den;
-	daddr_t blkno;
+	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 = dbtofsb(bp->b_blkno);
+		} else if(bp->b_bcount > MASKREG(htaddr->htfc))
+			bp->b_resid = bp->b_bcount - MASKREG(htaddr->htfc);
+	return (MBD_DONE);
+}
 
-    loop:
-	if ((bp = httab.b_actf) == NULL)
-		return;
-	unit = minor(bp->b_dev);
-	den = P800 | (unit&03);
-	if(unit >= 8)
-		den = P1600 | (unit&03);
-	if((HTADDR->httc&03777) != den)
-		HTADDR->httc = den;
-	unit &= 03;
-	blkno = h_blkno[unit];
-	if (bp == &chtbuf) {
-		if (bp->b_resid==NOP) {
-			bp->b_resid = HTADDR->htds & 0xffff;
-			goto next;
+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;
 		}
-		httab.b_active = SCOM;
-		HTADDR->htfc = 0;
-		HTADDR->htcs1 = bp->b_resid|GO;
-		return;
+		er &= ~HTER_FCE;
+		if (er == 0)
+			ds &= ~HTDS_ERR;
 	}
-	if (h_openf[unit] < 0 || dbtofsb(bp->b_blkno) > h_nxrec[unit])
-		goto abort;
-	if (blkno == dbtofsb(bp->b_blkno)) {
-		httab.b_active = SIO;
-		HTADDR->htfc = -bp->b_bcount;
-		mbastart(bp, (int *)HTADDR);
-	} else {
-		if (blkno < dbtofsb(bp->b_blkno)) {
-			httab.b_active = SSFOR;
-			HTADDR->htfc = blkno - dbtofsb(bp->b_blkno);
-			HTADDR->htcs1 = SFORW|GO;
+	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 > dbtofsb(bp->b_blkno)) {
+			sc->sc_nxrec = dbtofsb(bp->b_blkno) - fc;
+			sc->sc_blkno = sc->sc_nxrec;
 		} else {
-			httab.b_active = SSREV;
-			HTADDR->htfc = dbtofsb(bp->b_blkno) - blkno;
-			HTADDR->htcs1 = SREV|GO;
+			sc->sc_blkno = dbtofsb(bp->b_blkno) + fc;
+			sc->sc_nxrec = sc->sc_blkno - 1;
 		}
-	}
-	return;
+	else
+		sc->sc_blkno = dbtofsb(bp->b_blkno);
+	return (MBN_RETRY);
+}
 
-    abort:
-	bp->b_flags |= B_ERROR;
+htread(dev)
+	dev_t dev;
+{
 
-    next:
-	httab.b_actf = bp->av_forw;
-	iodone(bp);
-	goto loop;
+	htphys(dev);
+	if (u.u_error)
+		return;
+	physio(htstrategy, &rhtbuf[HTUNIT(dev)], dev, B_READ, minphys);
 }
 
-/*ARGSUSED*/
-htintr(mbastat, as)
+htwrite(dev)
 {
-	register struct buf *bp;
-	register int unit, state;
-	int err;
 
-	if ((bp = httab.b_actf)==NULL)
+	htphys(dev);
+	if (u.u_error)
 		return;
-	unit = minor(bp->b_dev) & 03;
-	state = httab.b_active;
-	httab.b_active = 0;
-	if (HTADDR->htds&(ERR|EOT|TM) || mbastat & MBAEBITS) {
-		err = HTADDR->hter & 0xffff;
-		if ((mbastat & MBAEBITS) || (err&HARD))
-			state = 0;
-		if (bp == &rhtbuf)
-			err &= ~FCE;
-		if ((bp->b_flags&B_READ) && (HTADDR->htds&PES))
-			err &= ~(CS|COR);
-		if(HTADDR->htds&EOT || (HTADDR->htds&MOL)==0) {
-			if(h_openf[unit])
-				h_openf[unit] = -1;
-		}
-		else if(HTADDR->htds&TM) {
-			HTADDR->htfc = 0;
-			h_nxrec[unit] = dbtofsb(bp->b_blkno);
-			state = SOK;
+	physio(htstrategy, &rhtbuf[HTUNIT(dev)], dev, B_WRITE, minphys);
+}
+
+htphys(dev)
+	dev_t dev;
+{
+	register int htunit;
+	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) {
+		u.u_error = ENXIO;
+		return;
+	}
+	a = u.u_offset >> 9;
+	sc = &tu_softc[TUUNIT(dev)];
+	sc->sc_blkno = dbtofsb(a);
+	sc->sc_nxrec = dbtofsb(a)+1;
+}
+
+/*ARGSUSED*/
+htioctl(dev, cmd, addr, flag)
+	dev_t dev;
+	int cmd;
+	caddr_t addr;
+	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 */
+		if (copyin((caddr_t)addr, (caddr_t)&mtop, sizeof(mtop))) {
+			u.u_error = EFAULT;
+			return;
 		}
-		else if(state && err == 0)
-			state = SOK;
-		if(httab.b_errcnt > 4)
-			deverror(bp, HTADDR->hter, mbastat);
-		((struct mba_regs *)MBA1)->mba_cr &= ~MBAIE;
-		HTADDR->htcs1 = DCLR|GO;
-		((struct mba_regs *)MBA1)->mba_cr |= MBAIE;
-		if (state==SIO && ++httab.b_errcnt < 10) {
-			httab.b_active = SRETRY;
-			h_blkno[unit]++;
-			HTADDR->htfc = -1;
-			HTADDR->htcs1 = SREV|GO;
+		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:
+			u.u_error = ENXIO;
 			return;
 		}
-		if (state!=SOK) {
-			bp->b_flags |= B_ERROR;
-			state = SIO;
+		if (callcount <= 0 || fcount <= 0) {
+			u.u_error = ENXIO;
+			return;
 		}
-	} else if (HTADDR->htcs1 < 0) {	/* SC */
-		if(HTADDR->htds & ERR) {
-			((struct mba_regs *)MBA1)->mba_cr &= ~MBAIE;
-			HTADDR->htcs1 = DCLR|GO;
-			((struct mba_regs *)MBA1)->mba_cr |= MBAIE;
+		while (--callcount >= 0) {
+			htcommand(dev, htops[mtop.mt_op], fcount);
+			if ((mtop.mt_op == MTFSR || mtop.mt_op == MTBSR) &&
+			    bp->b_resid) {
+				u.u_error = EIO;
+				break;
+			}
+			if ((bp->b_flags&B_ERROR) || sc->sc_dsreg&HTDS_BOT)
+				break;
 		}
+		geterror(bp);
+		return;
+	case MTIOCGET:
+		mtget.mt_dsreg = sc->sc_dsreg;
+		mtget.mt_erreg = sc->sc_erreg;
+		mtget.mt_resid = sc->sc_resid;
+		mtget.mt_type = MT_ISHT;
+		if (copyout((caddr_t)&mtget, addr, sizeof(mtget)))
+			u.u_error = EFAULT;
+		return;
+	default:
+		u.u_error = ENXIO;
 	}
-	switch(state) {
-	case SIO:
-	case SOK:
-		h_blkno[unit]++;
-
-	case SCOM:
-		httab.b_errcnt = 0;
-		httab.b_actf = bp->av_forw;
-		bp->b_resid = - (HTADDR->htfc & 0xffff);
-		if (bp->b_flags & B_READ)
-			bp->b_resid += bp->b_bcount;
-		iodone(bp);
-		break;
-
-	case SRETRY:
-		if((bp->b_flags&B_READ)==0) {
-			httab.b_active = SSFOR;
-			HTADDR->htcs1 = ERASE|GO;
-			return;
-		}
+}
 
-	case SSFOR:
-	case SSREV:
-#define blk dbtofsb(bp->b_blkno)
-		if(HTADDR->htds & TM) {
-			if(state == SSREV) {
-				h_nxrec[unit] = blk - (HTADDR->htfc&0xffff);
-				h_blkno[unit] = h_nxrec[unit];
-			} else {
-				h_nxrec[unit] = blk + (HTADDR->htfc&0xffff) - 1;
-				h_blkno[unit] = blk + (HTADDR->htfc & 0xffff);
-			}
-		} else
-			h_blkno[unit] = blk;
-		break;
+#define	DBSIZE	20
 
-	default:
-		return;
+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;
 	}
-	htstart();
+	hteof(htaddr);
+	hteof(htaddr);
+	htwait(htaddr);
+	if (htaddr->htds&HTDS_ERR)
+		return (EIO);
+	htaddr->htcs1 = HT_REW|HT_GO;
+	return (0);
 }
 
-htread(dev)
+htdwrite(dbuf, num, htaddr, mp)
+	register dbuf, num;
+	register struct htdevice *htaddr;
+	struct mba_regs *mp;
 {
-	htphys(dev);
-	physio(htstrategy, &rhtbuf, dev, B_READ, minphys);
+	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;
 }
 
-htwrite(dev)
+htwait(htaddr)
+	struct htdevice *htaddr;
 {
-	htphys(dev);
-	physio(htstrategy, &rhtbuf, dev, B_WRITE, minphys);
+	register s;
+
+	do
+		s = htaddr->htds;
+	while ((s & HTDS_DRY) == 0);
 }
 
-htphys(dev)
+hteof(htaddr)
+	struct htdevice *htaddr;
 {
-	register unit;
-	daddr_t a;
 
-	unit = minor(dev) & 03;
-	if(unit < NUNIT) {
-		a = u.u_offset >> 9;
-		h_blkno[unit] = dbtofsb(a);
-		h_nxrec[unit] = dbtofsb(a)+1;
-	}
+	htwait(htaddr);
+	htaddr->htcs1 = HT_WEOF|HT_GO;
 }
+#endif