#/* *//* * TJU16 tape driver */#include "../param.h"#include "../buf.h"#include "../conf.h"#include "../user.h"struct {	int	htcs1;	int	htwc;	int	htba;	int	htfc;	int	htcs2;	int	htds;	int	hter;	int	htas;	int	htck;	int	htdb;	int	htmr;	int	htdt;	int	htsn;	int	httc;	int	htbae;	/* 11/70 bus extension */};struct	devtab	httab;struct	buf	rhtbuf;#define	NUNIT	8char	h_openf[NUNIT];char	*h_blkno[NUNIT];char	*h_nxrec[NUNIT];#define	HTADDR	0172440#define	GO	01#define	NOP	0#define	WEOF	026#define	SFORW	030#define	SREV	032#define	ERASE	024#define	REW	06#define	CLR	010#define	P800	01300		/* 800 + pdp11 mode */#define	P1600	02300		/* 1600 + pdp11 mode */#define	IENABLE	0100#define	CRDY	0200#define	EOF	04#define	DRY	0200#define	MOL	010000#define	PIP	020000#define	ERR	040000#define	SSEEK	1#define	SIO	2htopen(dev, flag){	register unit;	unit = dev.d_minor&077;	if (unit >= NUNIT || h_openf[unit])		u.u_error = ENXIO;	else {		h_openf[unit]++;		h_blkno[unit] = 0;		h_nxrec[unit] = 65535;		hcommand(dev, NOP);	}}htclose(dev, flag){	register int unit;	unit = dev.d_minor&077;	h_openf[unit] = 0;	if (flag) {		hcommand(dev, WEOF);		hcommand(dev, WEOF);	}	hcommand(dev, REW);}hcommand(dev, com){	register unit;	extern lbolt;	unit = dev.d_minor;	while (httab.d_active || (HTADDR->htcs1 & CRDY)==0)		sleep(&lbolt, 1);	HTADDR->htcs2 = (unit>>3)&07;	while((HTADDR->htds&DRY) == 0)		sleep(&lbolt, 1);	if(unit >= 64)		HTADDR->httc = P800 | (unit&07); else		HTADDR->httc = P1600 | (unit&07);	while((HTADDR->htds&(MOL|PIP)) != MOL)		sleep(&lbolt, 1);	HTADDR->htcs1 = com | GO;}htstrategy(abp)struct buf *abp;{	register struct buf *bp;	register char **p;	bp = abp;	p = &h_nxrec[bp->b_dev.d_minor&077];	if (*p <= bp->b_blkno) {		if (*p < bp->b_blkno) {			bp->b_flags =| B_ERROR;			iodone(bp);			return;		}		if (bp->b_flags&B_READ) {			clrbuf(bp);			iodone(bp);			return;		}	}	if ((bp->b_flags&B_READ)==0)		*p = bp->b_blkno + 1;	bp->av_forw = 0;	spl5();	if (httab.d_actf==0)		httab.d_actf = bp;	else		httab.d_actl->av_forw = bp;	httab.d_actl = bp;	if (httab.d_active==0)		htstart();	spl0();}htstart(){	register struct buf *bp;	register int unit;	register char *blkno;    loop:	if ((bp = httab.d_actf) == 0)		return;	unit = bp->b_dev.d_minor;	HTADDR->htcs2 = (unit>>3)&07;	if(unit >= 64)		HTADDR->httc = P800 | (unit&07); else		HTADDR->httc = P1600 | (unit&07);	unit =& 077;	blkno = h_blkno[unit];	if (h_openf[unit] < 0 || (HTADDR->htcs1 & CRDY)==0) {		bp->b_flags =| B_ERROR;		httab.d_actf = bp->av_forw;		iodone(bp);		goto loop;	}	if (blkno != bp->b_blkno) {		httab.d_active = SSEEK;		if (blkno < bp->b_blkno) {			HTADDR->htfc = blkno - bp->b_blkno;			HTADDR->htcs1 = SFORW|IENABLE|GO;		} else {			if (bp->b_blkno == 0)				HTADDR->htcs1 = REW|IENABLE|GO;			else {				HTADDR->htfc = bp->b_blkno - blkno;				HTADDR->htcs1 = SREV|IENABLE|GO;			}		}		return;	}	httab.d_active = SIO;	rhstart(bp, &HTADDR->htfc, bp->b_wcount<<1, &HTADDR->htbae);}htintr(){	register struct buf *bp;	register int unit;	if ((bp = httab.d_actf)==0)		return;	unit = bp->b_dev.d_minor&077;	if (HTADDR->htcs1 & ERR) {/*		deverror(bp, HTADDR->hter, 0); */		if(HTADDR->htds&EOF) {			if(bp != &rhtbuf && h_openf[unit])				h_openf[unit] = -1;		}		HTADDR->htcs1 = ERR|CLR|GO;		if ((HTADDR->htds&DRY)!=0 && httab.d_active==SIO) {			if (++httab.d_errcnt < 10) {				h_blkno[unit]++;				httab.d_active = 0;				htstart();				return;			}		}		bp->b_flags =| B_ERROR;		httab.d_active = SIO;	}	if (httab.d_active == SIO) {		httab.d_errcnt = 0;		h_blkno[unit]++;		httab.d_actf = bp->av_forw;		httab.d_active = 0;		iodone(bp);		bp->b_resid = HTADDR->htfc;	} else		h_blkno[unit] = bp->b_blkno;	htstart();}htread(dev){	htphys(dev);	physio(htstrategy, &rhtbuf, dev, B_READ);	u.u_count = -rhtbuf.b_resid;}htwrite(dev){	htphys(dev);	physio(htstrategy, &rhtbuf, dev, B_WRITE);	u.u_count = 0;}htphys(dev){	register unit, a;	unit = dev.d_minor;	a = lshift(u.u_offset, -9);	h_blkno[unit] = a;	h_nxrec[unit] = ++a;}