xref: /csrg-svn/sys/vax/mba/hp.c (revision 1465)
1*1465Sbill /*	hp.c	3.16	10/16/80	*/
221Sbill 
321Sbill /*
4886Sbill  * RP06/RM03/RM05 disk driver
521Sbill  */
621Sbill 
721Sbill #include "../h/param.h"
821Sbill #include "../h/systm.h"
9305Sbill #include "../h/dk.h"
1021Sbill #include "../h/buf.h"
1121Sbill #include "../h/conf.h"
1221Sbill #include "../h/dir.h"
1321Sbill #include "../h/user.h"
1421Sbill #include "../h/map.h"
15420Sbill #include "../h/pte.h"
1621Sbill #include "../h/mba.h"
1721Sbill #include "../h/mtpr.h"
18420Sbill #include "../h/vm.h"
1921Sbill 
2021Sbill #define	DK_N	0
21344Sbill #define	DK_NMAX	1
2221Sbill 
2321Sbill struct	device
2421Sbill {
2521Sbill 	int	hpcs1;		/* control and Status register 1 */
2621Sbill 	int	hpds;		/* Drive Status */
2721Sbill 	int	hper1;		/* Error register 1 */
2821Sbill 	int	hpmr;		/* Maintenance */
2921Sbill 	int	hpas;		/* Attention Summary */
3021Sbill 	int	hpda;		/* Desired address register */
3121Sbill 	int	hpdt;		/* Drive type */
3221Sbill 	int	hpla;		/* Look ahead */
3321Sbill 	int	hpsn;		/* serial number */
3421Sbill 	int	hpof;		/* Offset register */
3521Sbill 	int	hpdc;		/* Desired Cylinder address register */
3621Sbill 	int	hpcc;		/* Current Cylinder */
3721Sbill 	int	hper2;		/* Error register 2 */
3821Sbill 	int	hper3;		/* Error register 3 */
3921Sbill 	int	hpec1;		/* Burst error bit position */
4021Sbill 	int	hpec2;		/* Burst error bit pattern */
4121Sbill };
4221Sbill 
43420Sbill #define	HPMBA		MBA0
44420Sbill #define	HPMBANUM	0
45420Sbill 
46342Sbill #define	NHP	2
4721Sbill #define	RP	022
4821Sbill #define	RM	024
49886Sbill #define	RM5	027
5021Sbill #define	NSECT	22
5121Sbill #define	NTRAC	19
5221Sbill #define	NRMSECT	32
5321Sbill #define	NRMTRAC	5
5421Sbill 
55305Sbill #define	_hpSDIST	3
56305Sbill #define	_hpRDIST	6
57305Sbill 
58305Sbill int	hpSDIST = _hpSDIST;
59305Sbill int	hpRDIST = _hpRDIST;
60305Sbill int	hpseek;
61305Sbill 
6221Sbill struct	size
6321Sbill {
6421Sbill 	daddr_t	nblocks;
6521Sbill 	int	cyloff;
6621Sbill } hp_sizes[8] =
6721Sbill {
68886Sbill 	15884,	0,		/* A=cyl 0 thru 37 */
69886Sbill 	33440,	38,		/* B=cyl 38 thru 117 */
70886Sbill 	340670,	0,		/* C=cyl 0 thru 814 */
7121Sbill 	0,	0,
7221Sbill 	0,	0,
7321Sbill 	0,	0,
74886Sbill 	291346,	118,		/* G=cyl 118 thru 814 */
7521Sbill 	0,	0,
7621Sbill }, rm_sizes[8] = {
77886Sbill 	15884,	0,		/* A=cyl 0 thru 99 */
78886Sbill 	33440,	100,		/* B=cyl 100 thru 309 */
79886Sbill 	131680,	0,		/* C=cyl 0 thru 822 */
8021Sbill 	0,	0,
8121Sbill 	0,	0,
8221Sbill 	0,	0,
83886Sbill 	82080,	310,		/* G=cyl 310 thru 822 */
8421Sbill 	0,	0,
85886Sbill }, rm5_sizes[8] = {
86886Sbill 	15884,	0,		/* A=cyl 0 thru 26 */
87886Sbill 	33440,	27,		/* B=cyl 27 thru 81 */
88886Sbill 	500992,	0,		/* C=cyl 0 thru 823 */
89886Sbill 	15884,	562,		/* D=cyl 562 thru 588 */
90886Sbill 	55936,	589,		/* E=cyl 589 thru 680 */
91886Sbill 	86944,	681,		/* F=cyl 681 thru 823 */
92886Sbill 	159296,	562,		/* G=cyl 562 thru 823 */
93886Sbill 	291346,	82,		/* H=cyl 82 thru 561 */
9421Sbill };
9521Sbill 
9621Sbill #define	P400	020
9721Sbill #define	M400	0220
9821Sbill #define	P800	040
9921Sbill #define	M800	0240
10021Sbill #define	P1200	060
10121Sbill #define	M1200	0260
10221Sbill int	hp_offset[16] =
10321Sbill {
10421Sbill 	P400, M400, P400, M400,
10521Sbill 	P800, M800, P800, M800,
10621Sbill 	P1200, M1200, P1200, M1200,
10721Sbill 	0, 0, 0, 0,
10821Sbill };
10921Sbill 
11021Sbill struct	buf	hptab;
11121Sbill struct	buf	rhpbuf;
11221Sbill struct	buf	hputab[NHP];
11321Sbill char	hp_type[NHP];	/* drive type */
11421Sbill 
11521Sbill #define	GO	01
11621Sbill #define	PRESET	020
11721Sbill #define	RTC	016
11821Sbill #define	OFFSET	014
119305Sbill #define	SEEK	04
12021Sbill #define	SEARCH	030
12121Sbill #define	RECAL	06
12221Sbill #define	DCLR	010
12321Sbill #define	WCOM	060
12421Sbill #define	RCOM	070
12521Sbill 
12621Sbill #define	IE	0100
12721Sbill #define	PIP	020000
12821Sbill #define	DRY	0200
12921Sbill #define	ERR	040000
13021Sbill #define	TRE	040000
13121Sbill #define	DCK	0100000
13221Sbill #define	WLE	04000
13321Sbill #define	ECH	0100
13421Sbill #define	VV	0100
13521Sbill #define	DPR	0400
13621Sbill #define	MOL	010000
13721Sbill #define	FMT22	010000
13821Sbill 
13921Sbill #define	b_cylin b_resid
14021Sbill 
14121Sbill #ifdef INTRLVE
14221Sbill daddr_t dkblock();
14321Sbill #endif
14421Sbill 
14521Sbill hpstrategy(bp)
14621Sbill register struct buf *bp;
14721Sbill {
14821Sbill 	register struct buf *dp;
14921Sbill 	register unit, xunit, nspc;
15021Sbill 	long sz, bn;
15121Sbill 	struct size *sizes;
15221Sbill 
153420Sbill 	if ((mbaact&(1<<HPMBANUM)) == 0)
154420Sbill 		mbainit(HPMBANUM);
15521Sbill 	xunit = minor(bp->b_dev) & 077;
15621Sbill 	sz = bp->b_bcount;
15721Sbill 	sz = (sz+511) >> 9;
15821Sbill 	unit = dkunit(bp);
15921Sbill 	if (hp_type[unit] == 0) {
16021Sbill 		struct device *hpaddr;
1611413Sbill 		double mspw;
16221Sbill 
16321Sbill 		/* determine device type */
164420Sbill 		hpaddr = mbadev(HPMBA, unit);
1651413Sbill 
1661413Sbill 		/* record transfer rate (these are guesstimates secs/word) */
1671413Sbill 		switch (hp_type[unit] = hpaddr->hpdt) {
1681413Sbill 		case RM:	mspw = .0000019728; break;
1691413Sbill 		case RM5:	mspw = .0000020345; break;
1701413Sbill 		case RP:	mspw = .0000029592; break;
1711413Sbill 		}
1721413Sbill 		if (DK_N + unit <= DK_NMAX)
1731413Sbill 			dk_mspw[DK_N+unit] = mspw;
17421Sbill 	}
175886Sbill 	switch (hp_type[unit]) {
176886Sbill 
177886Sbill 	case RM:
17821Sbill 		sizes = rm_sizes;
17921Sbill 		nspc = NRMSECT*NRMTRAC;
180886Sbill 		break;
181886Sbill 	case RM5:
182886Sbill 		sizes = rm5_sizes;
183886Sbill 		nspc = NRMSECT*NTRAC;
184886Sbill 		break;
185886Sbill 	case RP:
18621Sbill 		sizes = hp_sizes;
18721Sbill 		nspc = NSECT*NTRAC;
188886Sbill 		break;
189886Sbill 	default:
190886Sbill 		printf("hp: unknown device type 0%o\n", hp_type[unit]);
191886Sbill 		u.u_error = ENXIO;
192886Sbill 		unit = NHP+1;	/* force error */
19321Sbill 	}
19421Sbill 	if (unit >= NHP ||
19521Sbill 	    bp->b_blkno < 0 ||
19621Sbill 	    (bn = dkblock(bp))+sz > sizes[xunit&07].nblocks) {
19721Sbill 		bp->b_flags |= B_ERROR;
19821Sbill 		iodone(bp);
19921Sbill 		return;
20021Sbill 	}
20121Sbill 	bp->b_cylin = bn/nspc + sizes[xunit&07].cyloff;
20221Sbill 	dp = &hputab[unit];
203127Sbill 	(void) spl5();
20421Sbill 	disksort(dp, bp);
20521Sbill 	if (dp->b_active == 0) {
20621Sbill 		hpustart(unit);
20721Sbill 		if(hptab.b_active == 0)
20821Sbill 			hpstart();
20921Sbill 	}
210127Sbill 	(void) spl0();
21121Sbill }
21221Sbill 
21321Sbill hpustart(unit)
21421Sbill register unit;
21521Sbill {
21621Sbill 	register struct buf *bp, *dp;
21721Sbill 	register struct device *hpaddr;
21821Sbill 	daddr_t bn;
21921Sbill 	int sn, cn, csn;
22021Sbill 
22121Sbill 	((struct mba_regs *)MBA0)->mba_cr |= MBAIE;
222420Sbill 	hpaddr = mbadev(HPMBA, 0);
223420Sbill 	hpaddr->hpas = 1<<unit;
22421Sbill 
22521Sbill 	if(unit >= NHP)
22621Sbill 		return;
227344Sbill 	if (unit+DK_N <= DK_NMAX)
228344Sbill 		dk_busy &= ~(1<<(unit+DK_N));
22921Sbill 	dp = &hputab[unit];
23021Sbill 	if((bp=dp->b_actf) == NULL)
23121Sbill 		return;
232420Sbill 	hpaddr = mbadev(HPMBA, unit);
23321Sbill 	if((hpaddr->hpds & VV) == 0) {
23421Sbill 		hpaddr->hpcs1 = PRESET|GO;
23521Sbill 		hpaddr->hpof = FMT22;
23621Sbill 	}
23721Sbill 	if(dp->b_active)
23821Sbill 		goto done;
23921Sbill 	dp->b_active++;
24021Sbill 	if ((hpaddr->hpds & (DPR|MOL)) != (DPR|MOL))
24121Sbill 		goto done;
24221Sbill 
24321Sbill 	bn = dkblock(bp);
24421Sbill 	cn = bp->b_cylin;
245886Sbill 	switch (hp_type[unit]) {
246886Sbill 
247886Sbill 	case RM:
24821Sbill 		sn = bn%(NRMSECT*NRMTRAC);
249305Sbill 		sn = (sn+NRMSECT-hpSDIST)%NRMSECT;
250886Sbill 		break;
251886Sbill 	case RM5:
252886Sbill 		sn = bn%(NRMSECT*NTRAC);
253886Sbill 		sn = (sn+NRMSECT-hpSDIST)%NRMSECT;
254886Sbill 		break;
255886Sbill 	case RP:
25621Sbill 		sn = bn%(NSECT*NTRAC);
257305Sbill 		sn = (sn+NSECT-hpSDIST)%NSECT;
258886Sbill 		break;
259886Sbill 	default:
260886Sbill 		panic("hpustart");
26121Sbill 	}
26221Sbill 
26321Sbill 	if(cn - (hpaddr->hpdc & 0xffff))
26421Sbill 		goto search;
265305Sbill 	else if (hpseek)
266305Sbill 		goto done;
267305Sbill 	csn = ((hpaddr->hpla & 0xffff)>>6) - sn + 1;
26821Sbill 	if(csn < 0)
26921Sbill 		csn += NSECT;
270305Sbill 	if(csn > NSECT-hpRDIST)
27121Sbill 		goto done;
27221Sbill 
27321Sbill search:
27421Sbill 	hpaddr->hpdc = cn;
275305Sbill 	if (hpseek)
276305Sbill 		hpaddr->hpcs1 = SEEK|GO;
277305Sbill 	else {
278305Sbill 		hpaddr->hpda = sn;
279305Sbill 		hpaddr->hpcs1 = SEARCH|GO;
280305Sbill 	}
28121Sbill 	unit += DK_N;
282*1465Sbill 	if (unit <= DK_NMAX) {
283344Sbill 		dk_busy |= 1<<unit;
2841413Sbill 		dk_seek[unit]++;
285*1465Sbill 	}
28621Sbill 	return;
28721Sbill 
28821Sbill done:
28921Sbill 	dp->b_forw = NULL;
29021Sbill 	if(hptab.b_actf == NULL)
291344Sbill 		hptab.b_actf = dp;
292344Sbill 	else
29321Sbill 		hptab.b_actl->b_forw = dp;
29421Sbill 	hptab.b_actl = dp;
29521Sbill }
29621Sbill 
29721Sbill hpstart()
29821Sbill {
29921Sbill 	register struct buf *bp, *dp;
30021Sbill 	register unit;
30121Sbill 	register struct device *hpaddr;
30221Sbill 	daddr_t bn;
30321Sbill 	int dn, sn, tn, cn, nspc, ns;
30421Sbill 
30521Sbill loop:
30621Sbill 	if ((dp = hptab.b_actf) == NULL)
30721Sbill 		return;
30821Sbill 	if ((bp = dp->b_actf) == NULL) {
30921Sbill 		hptab.b_actf = dp->b_forw;
31021Sbill 		goto loop;
31121Sbill 	}
31221Sbill 	hptab.b_active++;
31321Sbill 	unit = minor(bp->b_dev) & 077;
31421Sbill 	dn = dkunit(bp);
31521Sbill 	bn = dkblock(bp);
316886Sbill 	switch (hp_type[dn]) {
317886Sbill 	case RM:
31821Sbill 		nspc = NRMSECT*NRMTRAC;
31921Sbill 		ns = NRMSECT;
32021Sbill 		cn = rm_sizes[unit&07].cyloff;
321886Sbill 		break;
322886Sbill 	case RM5:
323886Sbill 		nspc = NRMSECT*NTRAC;
324886Sbill 		ns = NRMSECT;
325886Sbill 		cn = rm5_sizes[unit&07].cyloff;
326886Sbill 		break;
327886Sbill 	case RP:
32821Sbill 		nspc = NSECT*NTRAC;
32921Sbill 		ns = NSECT;
33021Sbill 		cn = hp_sizes[unit&07].cyloff;
331886Sbill 		break;
332886Sbill 	default:
333886Sbill 		panic("hpstart");
33421Sbill 	}
33521Sbill 	cn += bn/nspc;
33621Sbill 	sn = bn%nspc;
33721Sbill 	tn = sn/ns;
33821Sbill 	sn = sn%ns;
33921Sbill 
340420Sbill 	hpaddr = mbadev(HPMBA, dn);
34121Sbill 	if ((hpaddr->hpds & (DPR|MOL)) != (DPR|MOL)) {
34221Sbill 		hptab.b_active = 0;
34321Sbill 		hptab.b_errcnt = 0;
34421Sbill 		dp->b_actf = bp->av_forw;
34521Sbill 		bp->b_flags |= B_ERROR;
34621Sbill 		iodone(bp);
34721Sbill 		goto loop;
34821Sbill 	}
349923Sbill 	if(hptab.b_errcnt >= 16 && (bp->b_flags&B_WRITE) == 0) {
35021Sbill 		hpaddr->hpof = hp_offset[hptab.b_errcnt & 017] | FMT22;
351420Sbill 		HPMBA->mba_cr &= ~MBAIE;
35221Sbill 		hpaddr->hpcs1 = OFFSET|GO;
35321Sbill 		while(hpaddr->hpds & PIP)
35421Sbill 			;
355420Sbill 		HPMBA->mba_cr |= MBAIE;
35621Sbill 	}
35721Sbill 	hpaddr->hpdc = cn;
35821Sbill 	hpaddr->hpda = (tn << 8) + sn;
35921Sbill 	mbastart(bp, (int *)hpaddr);
36021Sbill 
361344Sbill 	unit = dn+DK_N;
362344Sbill 	if (unit <= DK_NMAX) {
363344Sbill 		dk_busy |= 1<<unit;
3641413Sbill 		dk_xfer[unit]++;
365344Sbill 		dk_wds[unit] += bp->b_bcount>>6;
366344Sbill 	}
36721Sbill }
36821Sbill 
36921Sbill hpintr(mbastat, as)
37021Sbill {
37121Sbill 	register struct buf *bp, *dp;
37221Sbill 	register unit;
37321Sbill 	register struct device *hpaddr;
37421Sbill 
37521Sbill 	if(hptab.b_active) {
37621Sbill 		dp = hptab.b_actf;
37721Sbill 		bp = dp->b_actf;
37821Sbill 		unit = dkunit(bp);
3791413Sbill 		if (DK_N+unit <= DK_NMAX)
380344Sbill 			dk_busy &= ~(1<<(DK_N+unit));
381420Sbill 		hpaddr = mbadev(HPMBA, unit);
382420Sbill 		if (hpaddr->hpds & ERR || mbastat & MBAEBITS) {
38321Sbill 			while((hpaddr->hpds & DRY) == 0)
38421Sbill 				;
38521Sbill 			if(++hptab.b_errcnt > 28 || hpaddr->hper1&WLE)
386420Sbill 				bp->b_flags |= B_ERROR;
387420Sbill 			else
38821Sbill 				hptab.b_active = 0;
38921Sbill 			if(hptab.b_errcnt > 27)
39021Sbill 				deverror(bp, mbastat, hpaddr->hper1);
39121Sbill 			if ((hpaddr->hper1&0xffff) == DCK) {
39221Sbill 				if (hpecc(hpaddr, bp))
39321Sbill 					return;
39421Sbill 			}
39521Sbill 			hpaddr->hpcs1 = DCLR|GO;
39621Sbill 			if((hptab.b_errcnt&07) == 4) {
397420Sbill 				HPMBA->mba_cr &= ~MBAIE;
39821Sbill 				hpaddr->hpcs1 = RECAL|GO;
39921Sbill 				while(hpaddr->hpds & PIP)
40021Sbill 					;
401420Sbill 				HPMBA->mba_cr |= MBAIE;
40221Sbill 			}
40321Sbill 		}
40421Sbill 		if(hptab.b_active) {
40521Sbill 			if(hptab.b_errcnt) {
406420Sbill 				HPMBA->mba_cr &= ~MBAIE;
40721Sbill 				hpaddr->hpcs1 = RTC|GO;
40821Sbill 				while(hpaddr->hpds & PIP)
40921Sbill 					;
410420Sbill 				HPMBA->mba_cr |= MBAIE;
41121Sbill 			}
41221Sbill 			hptab.b_active = 0;
41321Sbill 			hptab.b_errcnt = 0;
41421Sbill 			hptab.b_actf = dp->b_forw;
41521Sbill 			dp->b_active = 0;
41621Sbill 			dp->b_errcnt = 0;
41721Sbill 			dp->b_actf = bp->av_forw;
418420Sbill 			bp->b_resid = -HPMBA->mba_bcr & 0xffff;
41921Sbill 			iodone(bp);
42021Sbill 			if(dp->b_actf)
42121Sbill 				hpustart(unit);
42221Sbill 		}
42321Sbill 		as &= ~(1<<unit);
42421Sbill 	} else {
42521Sbill 		if(as == 0)
426420Sbill 			HPMBA->mba_cr |= MBAIE;
42721Sbill 	}
42821Sbill 	for(unit=0; unit<NHP; unit++)
42921Sbill 		if(as & (1<<unit))
43021Sbill 			hpustart(unit);
43121Sbill 	hpstart();
43221Sbill }
43321Sbill 
43421Sbill hpread(dev)
43521Sbill {
43621Sbill 
43721Sbill 	physio(hpstrategy, &rhpbuf, dev, B_READ, minphys);
43821Sbill }
43921Sbill 
44021Sbill hpwrite(dev)
44121Sbill {
44221Sbill 
44321Sbill 	physio(hpstrategy, &rhpbuf, dev, B_WRITE, minphys);
44421Sbill }
44521Sbill 
44621Sbill hpecc(rp, bp)
44721Sbill register struct device *rp;
44821Sbill register struct buf *bp;
44921Sbill {
450420Sbill 	struct mba_regs *mbp = HPMBA;
451420Sbill 	register int i;
452420Sbill 	caddr_t addr;
453420Sbill 	int reg, bit, byte, npf, mask, o;
454420Sbill 	int dn, bn, cn, tn, sn, ns, nt;
455106Sbill 	extern char buffers[NBUF][BSIZE];
456420Sbill 	struct pte mpte;
457914Sbill 	int bcr;
45821Sbill 
459420Sbill 	/*
460420Sbill 	 * Npf is the number of sectors transferred before the sector
461420Sbill 	 * containing the ECC error, and reg is the MBA register
462420Sbill 	 * mapping (the first part of)the transfer.
463420Sbill 	 * O is offset within a memory page of the first byte transferred.
464420Sbill 	 */
465914Sbill 	bcr = mbp->mba_bcr & 0xffff;
466914Sbill 	if (bcr)
467914Sbill 		bcr |= 0xffff0000;		/* sxt */
468719Sbill 	npf = btop(bcr + bp->b_bcount) - 1;
4691413Sbill 	reg = npf;
470420Sbill 	o = (int)bp->b_un.b_addr & PGOFSET;
471420Sbill 	printf("%D ", bp->b_blkno + npf);
47221Sbill 	prdev("ECC", bp->b_dev);
47321Sbill 	mask = rp->hpec2&0xffff;
47421Sbill 	if (mask == 0) {
47521Sbill 		rp->hpof = FMT22;
476420Sbill 		return (0);
47721Sbill 	}
478420Sbill 
479420Sbill 	/*
480420Sbill 	 * Compute the byte and bit position of the error.
481420Sbill 	 * The variable i is the byte offset in the transfer,
482420Sbill 	 * the variable byte is the offset from a page boundary
483420Sbill 	 * in main memory.
484420Sbill 	 */
485420Sbill 	i = (rp->hpec1&0xffff) - 1;		/* -1 makes 0 origin */
486719Sbill 	bit = i&07;
487420Sbill 	i = (i&~07)>>3;
488420Sbill 	byte = i + o;
489420Sbill 	/*
490420Sbill 	 * Correct while possible bits remain of mask.  Since mask
491420Sbill 	 * contains 11 bits, we continue while the bit offset is > -11.
492420Sbill 	 * Also watch out for end of this block and the end of the whole
493420Sbill 	 * transfer.
494420Sbill 	 */
495420Sbill 	while (i < 512 && (int)ptob(npf)+i < bp->b_bcount && bit > -11) {
496420Sbill 		mpte = mbp->mba_map[reg+btop(byte)];
497420Sbill 		addr = ptob(mpte.pg_pfnum) + (byte & PGOFSET);
498420Sbill 		putmemc(addr, getmemc(addr)^(mask<<bit));
499420Sbill 		byte++;
500420Sbill 		i++;
501420Sbill 		bit -= 8;
50221Sbill 	}
503420Sbill 	hptab.b_active++;		/* Either complete or continuing */
504719Sbill 	if (bcr == 0)
505420Sbill 		return (0);
506420Sbill 	/*
507420Sbill 	 * Have to continue the transfer... clear the drive,
508420Sbill 	 * and compute the position where the transfer is to continue.
509420Sbill 	 * We have completed npf+1 sectores of the transfer already;
510420Sbill 	 * restart at offset o of next sector (i.e. in MBA register reg+1).
511420Sbill 	 */
512420Sbill 	rp->hpcs1 = DCLR|GO;
513420Sbill 	dn = dkunit(bp);
514420Sbill 	bn = dkblock(bp);
515886Sbill 	switch (hp_type[dn]) {
516886Sbill 
517886Sbill 	case RM:
518886Sbill 		ns = NRMSECT; nt = NRMTRAC; break;
519886Sbill 	case RM5:
520886Sbill 		ns = NRMSECT; nt = NTRAC; break;
521886Sbill 	case RP:
522886Sbill 		ns = NSECT; nt = NTRAC; break;
523886Sbill 	default:
524886Sbill 		panic("hpecc");
52521Sbill 	}
526420Sbill 	cn = bp->b_cylin;
527420Sbill 	sn = bn%(ns*nt) + npf + 1;
528420Sbill 	tn = sn/ns;
529420Sbill 	sn %= ns;
530420Sbill 	cn += tn/nt;
531420Sbill 	tn %= nt;
532420Sbill 	rp->hpdc = cn;
533420Sbill 	rp->hpda = (tn<<8) + sn;
534420Sbill 	mbp->mba_sr = -1;
535420Sbill 	mbp->mba_var = (int)ptob(reg+1) + o;
536420Sbill 	rp->hpcs1 = RCOM|GO;
537420Sbill 	return (1);
53821Sbill }
539