/* *  RL disk driver */#define DK_N	2#include "../h/param.h"#include "../h/buf.h"#include "../h/dir.h"#include "../h/user.h"#include "../h/systm.h"#define NRLBLK 10240#define RLCYLSZ 10240#define RLSECSZ 256#define RESET 013#define STAT 03#define GETSTAT 04#define WCOM 012#define RCOM 014#define SEEK 06#define SEEKHI 5#define SEEKLO 1#define RDHDR 010#define IENABLE 0100#define CRDY 0200#define OPI 02000#define CRCERR 04000#define TIMOUT 010000#define NXM 020000#define DE  040000struct device{	int rlcs, rlba, rlda, rlmp;};#define RLADDR	((struct device *)0174400)#define RL_CNT 1struct	buf	rrlbuf;struct	buf	rltab;struct {	int	cn[4];		/* location of heads for each drive */	int	dn;		/* drive number */	int	com;		/* read or write command word */	int	chn;		/* cylinder and head number */	unsigned int	bleft;	/* bytes left to be transferred */	unsigned int	bpart;	/* number of bytes transferred */	int	sn;		/* sector number */	union {		int	w[2];		long	l;	} addr;			/* address of memory for transfer */}	rl = {-1,-1,-1,-1};rlstrategy(bp)register struct buf *bp;{	if(bp->b_blkno >= NRLBLK) {		if(bp->b_blkno == NRLBLK && bp->b_flags&B_READ)			bp->b_resid = bp->b_bcount;		else {			bp->b_flags |= B_ERROR;			bp->b_error = ENXIO;		}		iodone(bp);		return;	}	bp->av_forw = NULL;	spl5();	if(rltab.b_actf == NULL)		rltab.b_actf = bp;	else		rltab.b_actl->av_forw = bp;	rltab.b_actl = bp;	if(rltab.b_active == NULL)		rlstart();	spl0();}rlstart(){	register struct buf *bp;	if ((bp = rltab.b_actf) == NULL)		return;	rltab.b_active++;	rl.dn = minor(bp->b_dev);	rl.chn = bp->b_blkno/20;	rl.sn = (bp->b_blkno%20) << 1;	rl.bleft = bp->b_bcount;	rl.addr.w[0] = bp->b_xmem & 3;	rl.addr.w[1] = (int)bp->b_un.b_addr;	rl.com = (rl.dn << 8) | IENABLE;	if (bp->b_flags & B_READ)		rl.com |= RCOM;	else		rl.com |= WCOM;	rlio();}rlintr(){	register struct buf *bp;	register struct device *rp;	register int status;	rp = RLADDR;	if (rltab.b_active == NULL) {/*		logstray(rp);*/		return;	}	bp = rltab.b_actf;	dk_busy &= ~(1<<DK_N);	if (rp->rlcs < 0) {		/* error bit */		if (rp->rlcs & 036000) {			if(rltab.b_errcnt > 2)				deverror(bp, rp->rlcs, rp->rlda);		}		if (rp->rlcs & 040000) {			rp->rlda = STAT;			rp->rlcs = (rl.dn << 8) | GETSTAT;			while ((rp->rlcs & CRDY) == 0)				;			status = rp->rlmp;			if(rltab.b_errcnt > 2)				deverror(bp, status, rp->rlda);			rp->rlda = RESET;			rp->rlcs = (rl.dn << 8) | GETSTAT;			while ((rp->rlcs & CRDY) == 0)				;			if(status & 01000) {				rlstart();				return;			}		}		if (++rltab.b_errcnt <= 10) {			rl.cn[rl.dn] = -1;			rlstart();			return;		}		else {			bp->b_flags |= B_ERROR;			rl.bpart = rl.bleft;		}	}	if ((rl.bleft -= rl.bpart) > 0) {		rl.addr.l += rl.bpart;		rl.sn=0;		rl.chn++;		rlio();		return;	}	rltab.b_active = NULL;	rltab.b_errcnt = 0;	rltab.b_actf = bp->av_forw;	bp->b_resid = 0;	iodone(bp);	rlstart();}rlio(){	register struct device *rp;	register dif;	register int head;	rp = RLADDR;	dk_busy |= 1<<DK_N;	dk_numb[DK_N] += 1;	head = rl.bpart>>6;	dk_wds[DK_N] += head;	if (rl.cn[rl.dn] < 0) {		rp->rlcs = (rl.dn << 8) | RDHDR;		while ((rp->rlcs&CRDY) == 0)			;		rl.cn[rl.dn] = (rp->rlmp&077700) >> 6;	}	dif =(rl.cn[rl.dn] >> 1) - (rl.chn >>1);	head = (rl.chn & 1) << 4;	if (dif < 0)		rp->rlda = (-dif <<7) | SEEKHI | head;	else		rp->rlda = (dif << 7) | SEEKLO | head;	rp->rlcs = (rl.dn << 8) | SEEK;	rl.cn[rl.dn] = rl.chn;	if (rl.bleft < (rl.bpart = RLCYLSZ - (rl.sn * RLSECSZ)))		rl.bpart = rl.bleft;	while ((rp->rlcs&CRDY) == 0)		;	rp->rlda = (rl.chn << 6) | rl.sn;	rp->rlba = rl.addr.w[1];	rp->rlmp = -(rl.bpart >> 1);	rp->rlcs = rl.com | rl.addr.w[0] << 4;}rlread(dev){	physio(rlstrategy, &rrlbuf, dev, B_READ);}rlwrite(dev){	physio(rlstrategy, &rrlbuf, dev, B_WRITE);}