xref: /csrg-svn/sys/vax/mba/hp.c (revision 5432)
1 /*	hp.c	4.43	82/01/17	*/
2 
3 #ifdef HPDEBUG
4 int	hpdebug;
5 #endif
6 #ifdef HPBDEBUG
7 int	hpbdebug;
8 #endif
9 
10 #include "hp.h"
11 #if NHP > 0
12 /*
13  * HP disk driver for RP0x+RMxx
14  *
15  * TODO:
16  *	check RM80 skip sector handling when ECC's occur later
17  *	check offset recovery handling
18  *	see if DCLR and/or RELEASE set attention status
19  *	print bits of mr && mr2 symbolically
20  */
21 
22 #include "../h/param.h"
23 #include "../h/systm.h"
24 #include "../h/dk.h"
25 #include "../h/buf.h"
26 #include "../h/conf.h"
27 #include "../h/dir.h"
28 #include "../h/user.h"
29 #include "../h/map.h"
30 #include "../h/pte.h"
31 #include "../h/mbareg.h"
32 #include "../h/mbavar.h"
33 #include "../h/mtpr.h"
34 #include "../h/vm.h"
35 #include "../h/cmap.h"
36 #include "../h/dkbad.h"
37 
38 #include "../h/hpreg.h"
39 
40 /* THIS SHOULD BE READ OFF THE PACK, PER DRIVE */
41 struct	size {
42 	daddr_t	nblocks;
43 	int	cyloff;
44 } hp6_sizes[8] = {
45 	15884,	0,		/* A=cyl 0 thru 37 */
46 	33440,	38,		/* B=cyl 38 thru 117 */
47 	340670,	0,		/* C=cyl 0 thru 814 */
48 	0,	0,
49 	0,	0,
50 	0,	0,
51 #ifndef NOBADSECT
52 	291280,	118,		/* G=cyl 118 thru 814 */
53 #else
54 	291346,	118,
55 #endif
56 	0,	0,
57 }, rm3_sizes[8] = {
58 	15884,	0,		/* A=cyl 0 thru 99 */
59 	33440,	100,		/* B=cyl 100 thru 309 */
60 	131680,	0,		/* C=cyl 0 thru 822 */
61 	0,	0,
62 	0,	0,
63 	0,	0,
64 #ifndef NOBADSECT
65 	81984,	310,		/* G=cyl 310 thru 822 */
66 #else
67 	82080,	310,
68 #endif
69 	0,	0,
70 }, rm5_sizes[8] = {
71 	15884,	0,		/* A=cyl 0 thru 26 */
72 	33440,	27,		/* B=cyl 27 thru 81 */
73 	500384,	0,		/* C=cyl 0 thru 822 */
74 	15884,	562,		/* D=cyl 562 thru 588 */
75 	55936,	589,		/* E=cyl 589 thru 680 */
76 #ifndef NOBADSECT
77 	86240,	681,		/* F=cyl 681 thru 822 */
78 	158592,	562,		/* G=cyl 562 thru 822 */
79 #else
80 	86636,	681,
81 	158688,	562,
82 #endif
83 	291346,	82,		/* H=cyl 82 thru 561 */
84 }, rm80_sizes[8] = {
85 	15884,	0,		/* A=cyl 0 thru 36 */
86 	33440,	37,		/* B=cyl 37 thru 114 */
87 	242606,	0,		/* C=cyl 0 thru 558 */
88 	0,	0,
89 	0,	0,
90 	0,	0,
91 	82080,	115,		/* G=cyl 115 thru 304 */
92 	110143,	305,		/* H=cyl 305 thru 558 */
93 }, hp7_sizes[8] = {
94 	15844,	0,		/* A=cyl 0 thru 9 */
95 	64000,	10,		/* B=cyl 10 thru 49 */
96 	1008000,0,		/* C=cyl 0 thru 629 */
97 	15884,	330,		/* D=cyl 330 thru 339 */
98 	256000,	340,		/* E=cyl 340 thru 499 */
99 	207850,	500,		/* F=cyl 500 thru 629 */
100 	479850,	330,		/* G=cyl 330 thru 629 */
101 	448000,	50,		/* H=cyl 50 thru 329 */
102 };
103 /* END OF STUFF WHICH SHOULD BE READ IN PER DISK */
104 
105 #define	_hpSDIST	2
106 #define	_hpRDIST	3
107 
108 int	hpSDIST = _hpSDIST;
109 int	hpRDIST = _hpRDIST;
110 
111 short	hptypes[] =
112 	{ MBDT_RM03, MBDT_RM05, MBDT_RP06, MBDT_RM80, MBDT_RP05, MBDT_RP07, 0 };
113 struct	mba_device *hpinfo[NHP];
114 int	hpattach(),hpustart(),hpstart(),hpdtint();
115 struct	mba_driver hpdriver =
116 	{ hpattach, 0, hpustart, hpstart, hpdtint, 0,
117 	  hptypes, "hp", 0, hpinfo };
118 
119 struct hpst {
120 	short	nsect;
121 	short	ntrak;
122 	short	nspc;
123 	short	ncyl;
124 	struct	size *sizes;
125 } hpst[] = {
126 	32,	5,	32*5,	823,	rm3_sizes,	/* RM03 */
127 	32,	19,	32*19,	823,	rm5_sizes,	/* RM05 */
128 	22,	19,	22*19,	815,	hp6_sizes,	/* RP06 */
129 	31,	14, 	31*14,	559,	rm80_sizes,	/* RM80 */
130 	22,	19,	22*19,	411,	hp6_sizes,	/* RP05 */
131 	50,	32,	50*32,	630,	hp7_sizes,	/* RP07 */
132 };
133 
134 u_char	hp_offset[16] = {
135     HPOF_P400, HPOF_M400, HPOF_P400, HPOF_M400,
136     HPOF_P800, HPOF_M800, HPOF_P800, HPOF_M800,
137     HPOF_P1200, HPOF_M1200, HPOF_P1200, HPOF_M1200,
138     0, 0, 0, 0,
139 };
140 
141 struct	buf	rhpbuf[NHP];
142 #ifndef NOBADSECT
143 struct	buf	bhpbuf[NHP];
144 struct	dkbad	hpbad[NHP];
145 #endif
146 char	hpinit[NHP];
147 char	hprecal[NHP];
148 
149 #define	b_cylin b_resid
150 
151 #ifdef INTRLVE
152 daddr_t dkblock();
153 #endif
154 
155 int	hpseek;
156 
157 /*ARGSUSED*/
158 hpattach(mi, slave)
159 	struct mba_device *mi;
160 {
161 	register struct hpst *st = &hpst[mi->mi_type];
162 
163 	if (mi->mi_dk >= 0)
164 		dk_mspw[mi->mi_dk] = 1.0 / 60 / (st->nsect * 256);
165 }
166 
167 hpstrategy(bp)
168 	register struct buf *bp;
169 {
170 	register struct mba_device *mi;
171 	register struct hpst *st;
172 	register int unit;
173 	long sz, bn;
174 	int xunit = minor(bp->b_dev) & 07;
175 	int s;
176 
177 	sz = bp->b_bcount;
178 	sz = (sz+511) >> 9;
179 	unit = dkunit(bp);
180 	if (unit >= NHP)
181 		goto bad;
182 	mi = hpinfo[unit];
183 	if (mi == 0 || mi->mi_alive == 0)
184 		goto bad;
185 	st = &hpst[mi->mi_type];
186 	if (bp->b_blkno < 0 ||
187 	    (bn = dkblock(bp))+sz > st->sizes[xunit].nblocks)
188 		goto bad;
189 	bp->b_cylin = bn/st->nspc + st->sizes[xunit].cyloff;
190 	s = spl5();
191 	disksort(&mi->mi_tab, bp);
192 	if (mi->mi_tab.b_active == 0)
193 		mbustart(mi);
194 	splx(s);
195 	return;
196 
197 bad:
198 	bp->b_flags |= B_ERROR;
199 	iodone(bp);
200 	return;
201 }
202 
203 hpustart(mi)
204 	register struct mba_device *mi;
205 {
206 	register struct hpdevice *hpaddr = (struct hpdevice *)mi->mi_drv;
207 	register struct buf *bp = mi->mi_tab.b_actf;
208 	register struct hpst *st = &hpst[mi->mi_type];
209 	daddr_t bn;
210 	int sn, dist;
211 
212 	hpaddr->hpcs1 = 0;
213 	if ((hpaddr->hpcs1&HP_DVA) == 0)
214 		return (MBU_BUSY);
215 	if ((hpaddr->hpds & HPDS_VV) == 0 || hpinit[mi->mi_unit] == 0) {
216 #ifndef NOBADSECT
217 		struct buf *bbp = &bhpbuf[mi->mi_unit];
218 #endif
219 
220 		hpinit[mi->mi_unit] = 1;
221 		hpaddr->hpcs1 = HP_DCLR|HP_GO;
222 		if (mi->mi_mba->mba_drv[0].mbd_as & (1<<mi->mi_drive))
223 			printf("DCLR attn\n");
224 		hpaddr->hpcs1 = HP_PRESET|HP_GO;
225 		hpaddr->hpof = HPOF_FMT22;
226 		mbclrattn(mi);
227 #ifndef NOBADSECT
228 		bbp->b_flags = B_READ|B_BUSY;
229 		bbp->b_dev = bp->b_dev;
230 		bbp->b_bcount = 512;
231 		bbp->b_un.b_addr = (caddr_t)&hpbad[mi->mi_unit];
232 		bbp->b_blkno = st->ncyl*st->nspc - st->nsect;
233 		bbp->b_cylin = st->ncyl - 1;
234 		mi->mi_tab.b_actf = bbp;
235 		bbp->av_forw = bp;
236 		bp = bbp;
237 #endif
238 	}
239 	if (mi->mi_tab.b_active || mi->mi_hd->mh_ndrive == 1)
240 		return (MBU_DODATA);
241 	if ((hpaddr->hpds & HPDS_DREADY) != HPDS_DREADY)
242 		return (MBU_DODATA);
243 	bn = dkblock(bp);
244 	sn = bn%st->nspc;
245 	sn = (sn+st->nsect-hpSDIST)%st->nsect;
246 	if (bp->b_cylin == (hpaddr->hpdc & 0xffff)) {
247 		if (hpseek)
248 			return (MBU_DODATA);
249 		dist = ((hpaddr->hpla & 0xffff)>>6) - st->nsect + 1;
250 		if (dist < 0)
251 			dist += st->nsect;
252 		if (dist > st->nsect - hpRDIST)
253 			return (MBU_DODATA);
254 	} else
255 		hpaddr->hpdc = bp->b_cylin;
256 	if (hpseek)
257 		hpaddr->hpcs1 = HP_SEEK|HP_GO;
258 	else {
259 		hpaddr->hpda = sn;
260 		hpaddr->hpcs1 = HP_SEARCH|HP_GO;
261 	}
262 	return (MBU_STARTED);
263 }
264 
265 hpstart(mi)
266 	register struct mba_device *mi;
267 {
268 	register struct hpdevice *hpaddr = (struct hpdevice *)mi->mi_drv;
269 	register struct buf *bp = mi->mi_tab.b_actf;
270 	register struct hpst *st = &hpst[mi->mi_type];
271 	daddr_t bn;
272 	int sn, tn;
273 
274 	bn = dkblock(bp);
275 	sn = bn%st->nspc;
276 	tn = sn/st->nsect;
277 	sn %= st->nsect;
278 	hpaddr->hpdc = bp->b_cylin;
279 	hpaddr->hpda = (tn << 8) + sn;
280 	return(0);
281 }
282 
283 hpdtint(mi, mbsr)
284 	register struct mba_device *mi;
285 	int mbsr;
286 {
287 	register struct hpdevice *hpaddr = (struct hpdevice *)mi->mi_drv;
288 	register struct buf *bp = mi->mi_tab.b_actf;
289 	int retry = 0;
290 
291 #ifndef NOBADSECT
292 	if (bp->b_flags&B_BAD) {
293 		if (hpecc(mi, CONT))
294 			return(MBD_RESTARTED);
295 	}
296 #endif
297 	if (hpaddr->hpds&HPDS_ERR || mbsr&MBSR_EBITS) {
298 #ifdef HPDEBUG
299 		if (hpdebug) {
300 			int dc = hpaddr->hpdc, da = hpaddr->hpda;
301 
302 			printf("hperr: bp %x cyl %d blk %d as %o ",
303 				bp, bp->b_cylin, bp->b_blkno,
304 				hpaddr->hpas&0xff);
305 			printf("dc %x da %x\n",dc&0xffff, da&0xffff);
306 			printf("errcnt %d ", mi->mi_tab.b_errcnt);
307 			printf("mbsr=%b ", mbsr, mbsr_bits);
308 			printf("er1=%b er2=%b\n",
309 			    hpaddr->hper1, HPER1_BITS,
310 			    hpaddr->hper2, HPER2_BITS);
311 			DELAY(1000000);
312 		}
313 #endif
314 		if (hpaddr->hper1&HPER1_WLE) {
315 			printf("hp%d: write locked\n", dkunit(bp));
316 			bp->b_flags |= B_ERROR;
317 		} else if (++mi->mi_tab.b_errcnt > 27 ||
318 		    mbsr & MBSR_HARD ||
319 		    hpaddr->hper1 & HPER1_HARD ||
320 		    hpaddr->hper2 & HPER2_HARD) {
321 hard:
322 			harderr(bp, "hp");
323 			if (mbsr & (MBSR_EBITS &~ (MBSR_DTABT|MBSR_MBEXC)))
324 				printf("mbsr=%b ", mbsr, mbsr_bits);
325 			printf("er1=%b er2=%b",
326 			    hpaddr->hper1, HPER1_BITS,
327 			    hpaddr->hper2, HPER2_BITS);
328 			if (hpaddr->hpmr)
329 				printf(" mr=%o", hpaddr->hpmr&0xffff);
330 			if (hpaddr->hpmr2)
331 				printf(" mr2=%o", hpaddr->hpmr2&0xffff);
332 			printf("\n");
333 			bp->b_flags |= B_ERROR;
334 			hprecal[mi->mi_unit] = 0;
335 		} else if (hpaddr->hper2 & HPER2_BSE) {
336 #ifndef NOBADSECT
337 			if (hpecc(mi, BSE))
338 				return(MBD_RESTARTED);
339 			else
340 #endif
341 				goto hard;
342 		} else if (hptypes[mi->mi_type] == MBDT_RM80 &&
343 		    hpaddr->hper2&HPER2_SSE) {
344 			(void) hpecc(mi, SSE);
345 			return (MBD_RESTARTED);
346 		} else if ((hpaddr->hper1&(HPER1_DCK|HPER1_ECH))==HPER1_DCK) {
347 			if (hpecc(mi, ECC))
348 				return (MBD_RESTARTED);
349 			/* else done */
350 		} else
351 			retry = 1;
352 		hpaddr->hpcs1 = HP_DCLR|HP_GO;
353 		if ((mi->mi_tab.b_errcnt&07) == 4) {
354 			hpaddr->hpcs1 = HP_RECAL|HP_GO;
355 			hprecal[mi->mi_unit] = 1;
356 			return(MBD_RESTARTED);
357 		}
358 		if (retry)
359 			return (MBD_RETRY);
360 	}
361 #ifdef HPDEBUG
362 	else
363 		if (hpdebug && hprecal[mi->mi_unit]) {
364 			printf("recal %d ", hprecal[mi->mi_unit]);
365 			printf("errcnt %d\n", mi->mi_tab.b_errcnt);
366 			printf("mbsr=%b ", mbsr, mbsr_bits);
367 			printf("er1=%b er2=%b\n",
368 			    hpaddr->hper1, HPER1_BITS,
369 			    hpaddr->hper2, HPER2_BITS);
370 		}
371 #endif
372 	switch (hprecal[mi->mi_unit]) {
373 
374 	case 1:
375 		hpaddr->hpdc = bp->b_cylin;
376 		hpaddr->hpcs1 = HP_SEEK|HP_GO;
377 		hprecal[mi->mi_unit]++;
378 		return (MBD_RESTARTED);
379 	case 2:
380 		if (mi->mi_tab.b_errcnt < 16 ||
381 		    (bp->b_flags & B_READ) == 0)
382 			goto donerecal;
383 		hpaddr->hpof = hp_offset[mi->mi_tab.b_errcnt & 017]|HPOF_FMT22;
384 		hpaddr->hpcs1 = HP_OFFSET|HP_GO;
385 		hprecal[mi->mi_unit]++;
386 		return (MBD_RESTARTED);
387 	donerecal:
388 	case 3:
389 		hprecal[mi->mi_unit] = 0;
390 		return (MBD_RETRY);
391 	}
392 	bp->b_resid = -(mi->mi_mba->mba_bcr) & 0xffff;
393 	if (mi->mi_tab.b_errcnt >= 16) {
394 		/*
395 		 * This is fast and occurs rarely; we don't
396 		 * bother with interrupts.
397 		 */
398 		hpaddr->hpcs1 = HP_RTC|HP_GO;
399 		while (hpaddr->hpds & HPDS_PIP)
400 			;
401 		mbclrattn(mi);
402 	}
403 	hpaddr->hpof = HPOF_FMT22;
404 	hpaddr->hpcs1 = HP_RELEASE|HP_GO;
405 	return (MBD_DONE);
406 }
407 
408 hpread(dev)
409 	dev_t dev;
410 {
411 	register int unit = minor(dev) >> 3;
412 
413 	if (unit >= NHP)
414 		u.u_error = ENXIO;
415 	else
416 		physio(hpstrategy, &rhpbuf[unit], dev, B_READ, minphys);
417 }
418 
419 hpwrite(dev)
420 	dev_t dev;
421 {
422 	register int unit = minor(dev) >> 3;
423 
424 	if (unit >= NHP)
425 		u.u_error = ENXIO;
426 	else
427 		physio(hpstrategy, &rhpbuf[unit], dev, B_WRITE, minphys);
428 }
429 
430 hpecc(mi, flag)
431 	register struct mba_device *mi;
432 	int flag;
433 {
434 	register struct mba_regs *mbp = mi->mi_mba;
435 	register struct hpdevice *rp = (struct hpdevice *)mi->mi_drv;
436 	register struct buf *bp = mi->mi_tab.b_actf;
437 	register struct hpst *st = &hpst[mi->mi_type];
438 	int npf, o;
439 	int bn, cn, tn, sn;
440 	int bcr;
441 
442 	bcr = mbp->mba_bcr & 0xffff;
443 	if (bcr)
444 		bcr |= 0xffff0000;		/* sxt */
445 #ifndef NOBADSECT
446 	if (flag == CONT)
447 		npf = bp->b_error;
448 	else
449 #endif
450 		npf = btop(bcr + bp->b_bcount);
451 	o = (int)bp->b_un.b_addr & PGOFSET;
452 	bn = dkblock(bp);
453 	cn = bp->b_cylin;
454 	sn = bn%(st->nspc) + npf;
455 	tn = sn/st->nsect;
456 	sn %= st->nsect;
457 	cn += tn/st->ntrak;
458 	tn %= st->ntrak;
459 	switch (flag) {
460 	case ECC:
461 		{
462 		register int i;
463 		caddr_t addr;
464 		struct pte mpte;
465 		int bit, byte, mask;
466 
467 		npf--;		/* because block in error is previous block */
468 		printf("hp%d%c: soft ecc sn%d\n", dkunit(bp),
469 		    'a'+(minor(bp->b_dev)&07), bp->b_blkno + npf);
470 		mask = rp->hpec2&0xffff;
471 		i = (rp->hpec1&0xffff) - 1;		/* -1 makes 0 origin */
472 		bit = i&07;
473 		i = (i&~07)>>3;
474 		byte = i + o;
475 		while (i < 512 && (int)ptob(npf)+i < bp->b_bcount && bit > -11) {
476 			mpte = mbp->mba_map[npf+btop(byte)];
477 			addr = ptob(mpte.pg_pfnum) + (byte & PGOFSET);
478 			putmemc(addr, getmemc(addr)^(mask<<bit));
479 			byte++;
480 			i++;
481 			bit -= 8;
482 		}
483 		if (bcr == 0)
484 			return (0);
485 		npf++;
486 		break;
487 		}
488 
489 	case SSE:
490 		rp->hpof |= HPOF_SSEI;
491 		mbp->mba_bcr = -(bp->b_bcount - (int)ptob(npf));
492 		break;
493 
494 #ifndef NOBADSECT
495 	case BSE:
496 #ifdef HPBDEBUG
497 		if (hpbdebug)
498 		printf("hpecc, BSE: bn %d cn %d tn %d sn %d\n", bn, cn, tn, sn);
499 #endif
500 		if ((bn = isbad(&hpbad[mi->mi_unit], cn, tn, sn)) < 0)
501 			return(0);
502 		bp->b_flags |= B_BAD;
503 		bp->b_error = npf + 1;
504 		bn = st->ncyl*st->nspc - st->nsect - 1 - bn;
505 		cn = bn/st->nspc;
506 		sn = bn%st->nspc;
507 		tn = sn/st->nsect;
508 		sn %= st->nsect;
509 		mbp->mba_bcr = -512;
510 #ifdef HPBDEBUG
511 		if (hpbdebug)
512 		printf("revector to cn %d tn %d sn %d\n", cn, tn, sn);
513 #endif
514 		break;
515 
516 	case CONT:
517 #ifdef HPBDEBUG
518 		if (hpbdebug)
519 		printf("hpecc, CONT: bn %d cn %d tn %d sn %d\n", bn,cn,tn,sn);
520 #endif
521 		npf = bp->b_error;
522 		bp->b_flags &= ~B_BAD;
523 		mbp->mba_bcr = -(bp->b_bcount - (int)ptob(npf));
524 		if ((mbp->mba_bcr & 0xffff) == 0)
525 			return(0);
526 		break;
527 #endif
528 	}
529 	rp->hpcs1 = HP_DCLR|HP_GO;
530 	if (rp->hpof&HPOF_SSEI)
531 		sn++;
532 	rp->hpdc = cn;
533 	rp->hpda = (tn<<8) + sn;
534 	mbp->mba_sr = -1;
535 	mbp->mba_var = (int)ptob(npf) + o;
536 	rp->hpcs1 = bp->b_flags&B_READ ? HP_RCOM|HP_GO : HP_WCOM|HP_GO;
537 	mi->mi_tab.b_errcnt = 0;	/* error has been corrected */
538 	return (1);
539 }
540 
541 #define	DBSIZE	20
542 
543 hpdump(dev)
544 	dev_t dev;
545 {
546 	register struct mba_device *mi;
547 	register struct mba_regs *mba;
548 	struct hpdevice *hpaddr;
549 	char *start;
550 	int num, unit;
551 	register struct hpst *st;
552 
553 	num = maxfree;
554 	start = 0;
555 	unit = minor(dev) >> 3;
556 	if (unit >= NHP)
557 		return (ENXIO);
558 #define	phys(a,b)	((b)((int)(a)&0x7fffffff))
559 	mi = phys(hpinfo[unit],struct mba_device *);
560 	if (mi == 0 || mi->mi_alive == 0)
561 		return (ENXIO);
562 	mba = phys(mi->mi_hd, struct mba_hd *)->mh_physmba;
563 	mba->mba_cr = MBCR_INIT;
564 	hpaddr = (struct hpdevice *)&mba->mba_drv[mi->mi_drive];
565 	if ((hpaddr->hpds & HPDS_VV) == 0) {
566 		hpaddr->hpcs1 = HP_DCLR|HP_GO;
567 		hpaddr->hpcs1 = HP_PRESET|HP_GO;
568 		hpaddr->hpof = HPOF_FMT22;
569 	}
570 	st = &hpst[mi->mi_type];
571 	if (dumplo < 0 || dumplo + num >= st->sizes[minor(dev)&07].nblocks)
572 		return (EINVAL);
573 	while (num > 0) {
574 		register struct pte *hpte = mba->mba_map;
575 		register int i;
576 		int blk, cn, sn, tn;
577 		daddr_t bn;
578 
579 		blk = num > DBSIZE ? DBSIZE : num;
580 		bn = dumplo + btop(start);
581 		cn = bn/st->nspc + st->sizes[minor(dev)&07].cyloff;
582 		sn = bn%st->nspc;
583 		tn = sn/st->nsect;
584 		sn = sn%st->nsect;
585 		hpaddr->hpdc = cn;
586 		hpaddr->hpda = (tn << 8) + sn;
587 		for (i = 0; i < blk; i++)
588 			*(int *)hpte++ = (btop(start)+i) | PG_V;
589 		mba->mba_sr = -1;
590 		mba->mba_bcr = -(blk*NBPG);
591 		mba->mba_var = 0;
592 		hpaddr->hpcs1 = HP_WCOM | HP_GO;
593 		while ((hpaddr->hpds & HPDS_DRY) == 0)
594 			;
595 		if (hpaddr->hpds&HPDS_ERR)
596 			return (EIO);
597 		start += blk*NBPG;
598 		num -= blk;
599 	}
600 	return (0);
601 }
602 #endif
603