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ccd.c revision 1.7
      1 /*	$NetBSD: ccd.c,v 1.7 1995/03/02 06:40:38 cgd Exp $      */
      2 
      3 /*
      4  * Copyright (c) 1988 University of Utah.
      5  * Copyright (c) 1990, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * the Systems Programming Group of the University of Utah Computer
     10  * Science Department.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Berkeley and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  * from: Utah $Hdr: cd.c 1.6 90/11/28$
     41  *
     42  *	@(#)cd.c	8.2 (Berkeley) 11/16/93
     43  */
     44 
     45 /*
     46  * "Concatenated" disk driver.
     47  */
     48 #include "ccd.h"
     49 #if NCCD > 0
     50 
     51 #include <sys/param.h>
     52 #include <sys/systm.h>
     53 #include <sys/proc.h>
     54 #include <sys/errno.h>
     55 #include <sys/dkstat.h>
     56 #include <sys/buf.h>
     57 #include <sys/malloc.h>
     58 #include <sys/conf.h>
     59 #include <sys/stat.h>
     60 #include <sys/ioctl.h>
     61 #include <sys/disklabel.h>
     62 #include <sys/fcntl.h>
     63 
     64 #include <dev/ccdvar.h>
     65 
     66 #ifdef DEBUG
     67 int ccddebug = 0x00;
     68 #define CCDB_FOLLOW	0x01
     69 #define CCDB_INIT	0x02
     70 #define CCDB_IO		0x04
     71 #endif
     72 
     73 #define	ccdunit(x)	DISKUNIT(x)
     74 
     75 struct ccdbuf {
     76 	struct buf	cb_buf;		/* new I/O buf */
     77 	struct buf	*cb_obp;	/* ptr. to original I/O buf */
     78 	int		cb_unit;	/* target unit */
     79 	int		cb_comp;	/* target component */
     80 };
     81 
     82 #define	getccdbuf()	\
     83 	((struct ccdbuf *)malloc(sizeof(struct ccdbuf), M_DEVBUF, M_WAITOK))
     84 #define putccdbuf(cbp)	\
     85 	free((caddr_t)(cbp), M_DEVBUF)
     86 
     87 struct ccd_softc {
     88 	int		 sc_flags;		/* flags */
     89 	size_t		 sc_size;		/* size of ccd */
     90 	int		 sc_ileave;		/* interleave */
     91 	int		 sc_nccdisks;		/* number of components */
     92 	struct ccdcinfo	 sc_cinfo[NCCDISKS];	/* component info */
     93 	struct ccdiinfo	 *sc_itable;		/* interleave table */
     94 	int		 sc_usecnt;		/* number of requests active */
     95 	int		 sc_dk;			/* disk index */
     96 };
     97 
     98 struct ccdbuf	*ccdbuffer __P((struct ccd_softc *cs, struct buf *bp,
     99 		    daddr_t bn, caddr_t addr, long bcount));
    100 char		*ccddevtostr __P((dev_t));
    101 void		ccdiodone __P((struct ccdbuf *cbp));
    102 
    103 /* sc_flags */
    104 #define	CCDF_ALIVE	0x01
    105 #define CCDF_INITED	0x02
    106 
    107 struct ccd_softc *ccd_softc;
    108 int numccd;
    109 
    110 /*
    111  * Since this is called after auto-configuration of devices,
    112  * we can handle the initialization here.
    113  *
    114  * XXX this will not work if you want to use a ccd as your primary
    115  * swap device since swapconf() has been called before now.
    116  */
    117 void
    118 ccdattach(num)
    119 	int num;
    120 {
    121 	char *mem;
    122 	register u_long size;
    123 	register struct ccddevice *ccd;
    124 	extern int dkn;
    125 
    126 	if (num <= 0)
    127 		return;
    128 	size = num * sizeof(struct ccd_softc);
    129 	mem = malloc(size, M_DEVBUF, M_NOWAIT);
    130 	if (mem == NULL) {
    131 		printf("WARNING: no memory for concatonated disks\n");
    132 		return;
    133 	}
    134 	bzero(mem, size);
    135 	ccd_softc = (struct ccd_softc *)mem;
    136 	numccd = num;
    137 	for (ccd = ccddevice; ccd->ccd_unit >= 0; ccd++) {
    138 		/*
    139 		 * XXX
    140 		 * Assign disk index first so that init routine
    141 		 * can use it (saves having the driver drag around
    142 		 * the ccddevice pointer just to set up the dk_*
    143 		 * info in the open routine).
    144 		 */
    145 		if (dkn < DK_NDRIVE)
    146 			ccd->ccd_dk = dkn++;
    147 		else
    148 			ccd->ccd_dk = -1;
    149 		if (ccdinit(ccd))
    150 			printf("ccd%d configured\n", ccd->ccd_unit);
    151 		else if (ccd->ccd_dk >= 0) {
    152 			ccd->ccd_dk = -1;
    153 			dkn--;
    154 		}
    155 	}
    156 }
    157 
    158 ccdinit(ccd)
    159 	struct ccddevice *ccd;
    160 {
    161 	register struct ccd_softc *cs = &ccd_softc[ccd->ccd_unit];
    162 	register struct ccdcinfo *ci;
    163 	register size_t size;
    164 	register int ix;
    165 	size_t minsize;
    166 	dev_t dev;
    167 	struct bdevsw *bsw;
    168 	struct partinfo dpart;
    169 	int error, (*ioctl)();
    170 	struct proc *p = curproc; /* XXX */
    171 
    172 #ifdef DEBUG
    173 	if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
    174 		printf("ccdinit: unit %d\n", ccd->ccd_unit);
    175 #endif
    176 	cs->sc_dk = ccd->ccd_dk;
    177 	cs->sc_size = 0;
    178 	cs->sc_ileave = ccd->ccd_interleave;
    179 	cs->sc_nccdisks = 0;
    180 	/*
    181 	 * Verify that each component piece exists and record
    182 	 * relevant information about it.
    183 	 */
    184 	minsize = 0;
    185 	for (ix = 0; ix < NCCDISKS; ix++) {
    186 		if ((dev = ccd->ccd_dev[ix]) == NODEV)
    187 			break;
    188 		ci = &cs->sc_cinfo[ix];
    189 		ci->ci_dev = dev;
    190 		bsw = &bdevsw[major(dev)];
    191 		/*
    192 		 * Open the partition
    193 		 */
    194 		if (bsw->d_open &&
    195 		    (error = (*bsw->d_open)(dev, 0, S_IFBLK, p))) {
    196 			printf("ccd%d: component %s open failed, error = %d\n",
    197 			       ccd->ccd_unit, ccddevtostr(dev), error);
    198 			return(0);
    199 		}
    200 		/*
    201 		 * Calculate size (truncated to interleave boundary
    202 		 * if necessary.
    203 		 */
    204 		if ((ioctl = bdevsw[major(dev)].d_ioctl) != NULL &&
    205 		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0)
    206 			if (dpart.part->p_fstype == FS_BSDFFS)
    207 				size = dpart.part->p_size;
    208 			else
    209 				size = 0;
    210 		else
    211 			size = 0;
    212 
    213 		if (size < 0)
    214 			size = 0;
    215 
    216 		if (cs->sc_ileave > 1)
    217 			size -= size % cs->sc_ileave;
    218 		if (size == 0) {
    219 			printf("ccd%d: not configured (component %s missing)\n",
    220 			       ccd->ccd_unit, ccddevtostr(dev));
    221 			return(0);
    222 		}
    223 #ifdef COMPAT_NOLABEL
    224 		/*
    225 		 * XXX if this is a 'c' partition then we need to mark the
    226 		 * label area writeable since there cannot be a label.
    227 		 */
    228 		if ((minor(dev) & 7) == 2 && bsw->d_open) {
    229 			int i, flag;
    230 
    231 			for (i = 0; i < nchrdev; i++)
    232 				if (cdevsw[i].d_open == bsw->d_open)
    233 					break;
    234 			if (i != nchrdev && cdevsw[i].d_ioctl) {
    235 				flag = 1;
    236 				(void)(*cdevsw[i].d_ioctl)(dev, DIOCWLABEL,
    237 					(caddr_t)&flag, FWRITE, p);
    238 			}
    239 		}
    240 #endif
    241 		if (minsize == 0 || size < minsize)
    242 			minsize = size;
    243 		ci->ci_size = size;
    244 		cs->sc_size += size;
    245 		cs->sc_nccdisks++;
    246 	}
    247 	/*
    248 	 * If uniform interleave is desired set all sizes to that of
    249 	 * the smallest component.
    250 	 */
    251 	if (ccd->ccd_flags & CCDF_UNIFORM) {
    252 		for (ci = cs->sc_cinfo;
    253 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    254 			ci->ci_size = minsize;
    255 		cs->sc_size = cs->sc_nccdisks * minsize;
    256 	}
    257 	/*
    258 	 * Construct the interleave table
    259 	 */
    260 	if (!ccdinterleave(cs))
    261 		return(0);
    262 	if (ccd->ccd_dk >= 0)
    263 		dk_wpms[ccd->ccd_dk] = 32 * (60 * DEV_BSIZE / 2);	/* XXX */
    264 	printf("ccd%d: %d components ", ccd->ccd_unit, cs->sc_nccdisks);
    265 	for (ix = 0; ix < cs->sc_nccdisks; ix++)
    266 		printf("%c%s%c",
    267 		       ix == 0 ? '(' : ' ',
    268 		       ccddevtostr(cs->sc_cinfo[ix].ci_dev),
    269 		       ix == cs->sc_nccdisks - 1 ? ')' : ',');
    270 	printf(", %d blocks ", cs->sc_size);
    271 	if (cs->sc_ileave)
    272 		printf("interleaved at %d blocks\n", cs->sc_ileave);
    273 	else
    274 		printf("concatenated\n");
    275 	cs->sc_flags = CCDF_ALIVE | CCDF_INITED;
    276 	return(1);
    277 }
    278 
    279 /*
    280  * XXX not really ccd specific.
    281  * Could be called something like bdevtostr in machine/conf.c.
    282  */
    283 char *
    284 ccddevtostr(dev)
    285 	dev_t dev;
    286 {
    287 	static char dbuf[5];
    288 
    289 	switch (major(dev)) {
    290 #ifdef hp300
    291 	case 2:
    292 		dbuf[0] = 'r'; dbuf[1] = 'd';
    293 		break;
    294 	case 4:
    295 		dbuf[0] = 's'; dbuf[1] = 'd';
    296 		break;
    297 	case 5:
    298 		dbuf[0] = 'c'; dbuf[1] = 'd';
    299 		break;
    300 	case 6:
    301 		dbuf[0] = 'v'; dbuf[1] = 'n';
    302 		break;
    303 #endif
    304 #ifdef i386
    305 	case 0:
    306 		dbuf[0] = 'w'; dbuf[1] = 'd';
    307 		break;
    308 	case 2:
    309 		dbuf[0] = 'f'; dbuf[1] = 'd';
    310 		break;
    311 	case 4:
    312 		dbuf[0] = 's'; dbuf[1] = 'd';
    313 		break;
    314 	case 14:
    315 		dbuf[0] = 'v'; dbuf[1] = 'n';
    316 		break;
    317 #endif
    318 	default:
    319 		dbuf[0] = dbuf[1] = '?';
    320 		break;
    321 	}
    322 	dbuf[2] = (minor(dev) >> 3) + '0';
    323 	dbuf[3] = (minor(dev) & 7) + 'a';
    324 	dbuf[4] = '\0';
    325 	return (dbuf);
    326 }
    327 
    328 ccdinterleave(cs)
    329 	register struct ccd_softc *cs;
    330 {
    331 	register struct ccdcinfo *ci, *smallci;
    332 	register struct ccdiinfo *ii;
    333 	register daddr_t bn, lbn;
    334 	register int ix;
    335 	u_long size;
    336 
    337 #ifdef DEBUG
    338 	if (ccddebug & CCDB_INIT)
    339 		printf("ccdinterleave(%x): ileave %d\n", cs, cs->sc_ileave);
    340 #endif
    341 	/*
    342 	 * Allocate an interleave table.
    343 	 * Chances are this is too big, but we don't care.
    344 	 */
    345 	size = (cs->sc_nccdisks + 1) * sizeof(struct ccdiinfo);
    346 	cs->sc_itable = (struct ccdiinfo *)malloc(size, M_DEVBUF, M_WAITOK);
    347 	bzero((caddr_t)cs->sc_itable, size);
    348 	/*
    349 	 * Trivial case: no interleave (actually interleave of disk size).
    350 	 * Each table entry represent a single component in its entirety.
    351 	 */
    352 	if (cs->sc_ileave == 0) {
    353 		bn = 0;
    354 		ii = cs->sc_itable;
    355 		for (ix = 0; ix < cs->sc_nccdisks; ix++) {
    356 			ii->ii_ndisk = 1;
    357 			ii->ii_startblk = bn;
    358 			ii->ii_startoff = 0;
    359 			ii->ii_index[0] = ix;
    360 			bn += cs->sc_cinfo[ix].ci_size;
    361 			ii++;
    362 		}
    363 		ii->ii_ndisk = 0;
    364 #ifdef DEBUG
    365 		if (ccddebug & CCDB_INIT)
    366 			printiinfo(cs->sc_itable);
    367 #endif
    368 		return(1);
    369 	}
    370 	/*
    371 	 * The following isn't fast or pretty; it doesn't have to be.
    372 	 */
    373 	size = 0;
    374 	bn = lbn = 0;
    375 	for (ii = cs->sc_itable; ; ii++) {
    376 		/*
    377 		 * Locate the smallest of the remaining components
    378 		 */
    379 		smallci = NULL;
    380 		for (ci = cs->sc_cinfo;
    381 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    382 			if (ci->ci_size > size &&
    383 			    (smallci == NULL ||
    384 			     ci->ci_size < smallci->ci_size))
    385 				smallci = ci;
    386 		/*
    387 		 * Nobody left, all done
    388 		 */
    389 		if (smallci == NULL) {
    390 			ii->ii_ndisk = 0;
    391 			break;
    392 		}
    393 		/*
    394 		 * Record starting logical block and component offset
    395 		 */
    396 		ii->ii_startblk = bn / cs->sc_ileave;
    397 		ii->ii_startoff = lbn;
    398 		/*
    399 		 * Determine how many disks take part in this interleave
    400 		 * and record their indices.
    401 		 */
    402 		ix = 0;
    403 		for (ci = cs->sc_cinfo;
    404 		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
    405 			if (ci->ci_size >= smallci->ci_size)
    406 				ii->ii_index[ix++] = ci - cs->sc_cinfo;
    407 		ii->ii_ndisk = ix;
    408 		bn += ix * (smallci->ci_size - size);
    409 		lbn = smallci->ci_size / cs->sc_ileave;
    410 		size = smallci->ci_size;
    411 	}
    412 #ifdef DEBUG
    413 	if (ccddebug & CCDB_INIT)
    414 		printiinfo(cs->sc_itable);
    415 #endif
    416 	return(1);
    417 }
    418 
    419 #ifdef DEBUG
    420 printiinfo(ii)
    421 	struct ccdiinfo *ii;
    422 {
    423 	register int ix, i;
    424 
    425 	for (ix = 0; ii->ii_ndisk; ix++, ii++) {
    426 		printf(" itab[%d]: #dk %d sblk %d soff %d",
    427 		       ix, ii->ii_ndisk, ii->ii_startblk, ii->ii_startoff);
    428 		for (i = 0; i < ii->ii_ndisk; i++)
    429 			printf(" %d", ii->ii_index[i]);
    430 		printf("\n");
    431 	}
    432 }
    433 #endif
    434 
    435 ccdopen(dev, flags)
    436 	dev_t dev;
    437 {
    438 	int unit = ccdunit(dev);
    439 	register struct ccd_softc *cs = &ccd_softc[unit];
    440 
    441 #ifdef DEBUG
    442 	if (ccddebug & CCDB_FOLLOW)
    443 		printf("ccdopen(%x, %x)\n", dev, flags);
    444 #endif
    445 	if (unit >= numccd || (cs->sc_flags & CCDF_ALIVE) == 0)
    446 		return(ENXIO);
    447 	return(0);
    448 }
    449 
    450 ccdclose(dev, flags)
    451 	dev_t dev;
    452 	int flags;
    453 {
    454 #ifdef DEBUG
    455 	if (ccddebug & CCDB_FOLLOW)
    456 		printf("ccdclose(%x, %x)\n", dev, flags);
    457 #endif
    458 	return (0);
    459 }
    460 
    461 ccdstrategy(bp)
    462 	register struct buf *bp;
    463 {
    464 	register int unit = ccdunit(bp->b_dev);
    465 	register struct ccd_softc *cs = &ccd_softc[unit];
    466 	register daddr_t bn;
    467 	register int sz, s;
    468 
    469 #ifdef DEBUG
    470 	if (ccddebug & CCDB_FOLLOW)
    471 		printf("ccdstrategy(%x): unit %d\n", bp, unit);
    472 #endif
    473 	if ((cs->sc_flags & CCDF_INITED) == 0) {
    474 		bp->b_error = ENXIO;
    475 		bp->b_flags |= B_ERROR;
    476 		goto done;
    477 	}
    478 	bn = bp->b_blkno;
    479 	sz = howmany(bp->b_bcount, DEV_BSIZE);
    480 	if (bn < 0 || bn + sz > cs->sc_size) {
    481 		sz = cs->sc_size - bn;
    482 		if (sz == 0) {
    483 			bp->b_resid = bp->b_bcount;
    484 			goto done;
    485 		}
    486 		if (sz < 0) {
    487 			bp->b_error = EINVAL;
    488 			bp->b_flags |= B_ERROR;
    489 			goto done;
    490 		}
    491 		bp->b_bcount = dbtob(sz);
    492 	}
    493 	bp->b_resid = bp->b_bcount;
    494 	/*
    495 	 * "Start" the unit.
    496 	 */
    497 	s = splbio();
    498 	ccdstart(cs, bp);
    499 	splx(s);
    500 	return;
    501 done:
    502 	biodone(bp);
    503 }
    504 
    505 ccdstart(cs, bp)
    506 	register struct ccd_softc *cs;
    507 	register struct buf *bp;
    508 {
    509 	register long bcount, rcount;
    510 	struct ccdbuf *cbp;
    511 	caddr_t addr;
    512 	daddr_t bn;
    513 
    514 #ifdef DEBUG
    515 	if (ccddebug & CCDB_FOLLOW)
    516 		printf("ccdstart(%x, %x)\n", cs, bp);
    517 #endif
    518 	/*
    519 	 * Instumentation (not real meaningful)
    520 	 */
    521 	cs->sc_usecnt++;
    522 	if (cs->sc_dk >= 0) {
    523 		dk_busy |= 1 << cs->sc_dk;
    524 		dk_xfer[cs->sc_dk]++;
    525 		dk_wds[cs->sc_dk] += bp->b_bcount >> 6;
    526 	}
    527 	/*
    528 	 * Allocate component buffers and fire off the requests
    529 	 */
    530 	bn = bp->b_blkno;
    531 	addr = bp->b_data;
    532 	for (bcount = bp->b_bcount; bcount > 0; bcount -= rcount) {
    533 		cbp = ccdbuffer(cs, bp, bn, addr, bcount);
    534 		rcount = cbp->cb_buf.b_bcount;
    535 		(*bdevsw[major(cbp->cb_buf.b_dev)].d_strategy)(&cbp->cb_buf);
    536 		bn += btodb(rcount);
    537 		addr += rcount;
    538 	}
    539 }
    540 
    541 /*
    542  * Build a component buffer header.
    543  */
    544 struct ccdbuf *
    545 ccdbuffer(cs, bp, bn, addr, bcount)
    546 	register struct ccd_softc *cs;
    547 	struct buf *bp;
    548 	daddr_t bn;
    549 	caddr_t addr;
    550 	long bcount;
    551 {
    552 	register struct ccdcinfo *ci;
    553 	register struct ccdbuf *cbp;
    554 	register daddr_t cbn, cboff;
    555 
    556 #ifdef DEBUG
    557 	if (ccddebug & CCDB_IO)
    558 		printf("ccdbuffer(%x, %x, %d, %x, %d)\n",
    559 		       cs, bp, bn, addr, bcount);
    560 #endif
    561 	/*
    562 	 * Determine which component bn falls in.
    563 	 */
    564 	cbn = bn;
    565 	cboff = 0;
    566 	/*
    567 	 * Serially concatenated
    568 	 */
    569 	if (cs->sc_ileave == 0) {
    570 		register daddr_t sblk;
    571 
    572 		sblk = 0;
    573 		for (ci = cs->sc_cinfo; cbn >= sblk + ci->ci_size; ci++)
    574 			sblk += ci->ci_size;
    575 		cbn -= sblk;
    576 	}
    577 	/*
    578 	 * Interleaved
    579 	 */
    580 	else {
    581 		register struct ccdiinfo *ii;
    582 		int ccdisk, off;
    583 
    584 		cboff = cbn % cs->sc_ileave;
    585 		cbn /= cs->sc_ileave;
    586 		for (ii = cs->sc_itable; ii->ii_ndisk; ii++)
    587 			if (ii->ii_startblk > cbn)
    588 				break;
    589 		ii--;
    590 		off = cbn - ii->ii_startblk;
    591 		if (ii->ii_ndisk == 1) {
    592 			ccdisk = ii->ii_index[0];
    593 			cbn = ii->ii_startoff + off;
    594 		} else {
    595 			ccdisk = ii->ii_index[off % ii->ii_ndisk];
    596 			cbn = ii->ii_startoff + off / ii->ii_ndisk;
    597 		}
    598 		cbn *= cs->sc_ileave;
    599 		ci = &cs->sc_cinfo[ccdisk];
    600 	}
    601 	/*
    602 	 * Fill in the component buf structure.
    603 	 */
    604 	cbp = getccdbuf();
    605 	cbp->cb_buf.b_flags = bp->b_flags | B_CALL;
    606 	cbp->cb_buf.b_iodone = (void (*)())ccdiodone;
    607 	cbp->cb_buf.b_proc = bp->b_proc;
    608 	cbp->cb_buf.b_dev = ci->ci_dev;
    609 	cbp->cb_buf.b_blkno = cbn + cboff;
    610 	cbp->cb_buf.b_data = addr;
    611 	cbp->cb_buf.b_vp = 0;
    612 	if (cs->sc_ileave == 0)
    613 		cbp->cb_buf.b_bcount = dbtob(ci->ci_size - cbn);
    614 	else
    615 		cbp->cb_buf.b_bcount = dbtob(cs->sc_ileave - cboff);
    616 	if (cbp->cb_buf.b_bcount > bcount)
    617 		cbp->cb_buf.b_bcount = bcount;
    618 
    619 	/*
    620 	 * context for ccdiodone
    621 	 */
    622 	cbp->cb_obp = bp;
    623 	cbp->cb_unit = cs - ccd_softc;
    624 	cbp->cb_comp = ci - cs->sc_cinfo;
    625 
    626 #ifdef DEBUG
    627 	if (ccddebug & CCDB_IO)
    628 		printf(" dev %x(u%d): cbp %x bn %d addr %x bcnt %d\n",
    629 		       ci->ci_dev, ci-cs->sc_cinfo, cbp, cbp->cb_buf.b_blkno,
    630 		       cbp->cb_buf.b_data, cbp->cb_buf.b_bcount);
    631 #endif
    632 	return (cbp);
    633 }
    634 
    635 ccdintr(cs, bp)
    636 	register struct ccd_softc *cs;
    637 	register struct buf *bp;
    638 {
    639 
    640 #ifdef DEBUG
    641 	if (ccddebug & CCDB_FOLLOW)
    642 		printf("ccdintr(%x, %x)\n", cs, bp);
    643 #endif
    644 	/*
    645 	 * Request is done for better or worse, wakeup the top half.
    646 	 */
    647 	if (--cs->sc_usecnt == 0 && cs->sc_dk >= 0)
    648 		dk_busy &= ~(1 << cs->sc_dk);
    649 	if (bp->b_flags & B_ERROR)
    650 		bp->b_resid = bp->b_bcount;
    651 	biodone(bp);
    652 }
    653 
    654 /*
    655  * Called by biodone at interrupt time.
    656  * Mark the component as done and if all components are done,
    657  * take a ccd interrupt.
    658  */
    659 void
    660 ccdiodone(cbp)
    661 	register struct ccdbuf *cbp;
    662 {
    663 	register struct buf *bp = cbp->cb_obp;
    664 	register int unit = cbp->cb_unit;
    665 	int count, s;
    666 
    667 	s = splbio();
    668 #ifdef DEBUG
    669 	if (ccddebug & CCDB_FOLLOW)
    670 		printf("ccdiodone(%x)\n", cbp);
    671 	if (ccddebug & CCDB_IO) {
    672 		printf("ccdiodone: bp %x bcount %d resid %d\n",
    673 		       bp, bp->b_bcount, bp->b_resid);
    674 		printf(" dev %x(u%d), cbp %x bn %d addr %x bcnt %d\n",
    675 		       cbp->cb_buf.b_dev, cbp->cb_comp, cbp,
    676 		       cbp->cb_buf.b_blkno, cbp->cb_buf.b_data,
    677 		       cbp->cb_buf.b_bcount);
    678 	}
    679 #endif
    680 
    681 	if (cbp->cb_buf.b_flags & B_ERROR) {
    682 		bp->b_flags |= B_ERROR;
    683 		bp->b_error = cbp->cb_buf.b_error ? cbp->cb_buf.b_error : EIO;
    684 #ifdef DEBUG
    685 		printf("ccd%d: error %d on component %d\n",
    686 		       unit, bp->b_error, cbp->cb_comp);
    687 #endif
    688 	}
    689 	count = cbp->cb_buf.b_bcount;
    690 	putccdbuf(cbp);
    691 
    692 	/*
    693 	 * If all done, "interrupt".
    694 	 */
    695 	bp->b_resid -= count;
    696 	if (bp->b_resid < 0)
    697 		panic("ccdiodone: count");
    698 	if (bp->b_resid == 0)
    699 		ccdintr(&ccd_softc[unit], bp);
    700 	splx(s);
    701 }
    702 
    703 ccdread(dev, uio)
    704 	dev_t dev;
    705 	struct uio *uio;
    706 {
    707 	register int unit = ccdunit(dev);
    708 
    709 #ifdef DEBUG
    710 	if (ccddebug & CCDB_FOLLOW)
    711 		printf("ccdread(%x, %x)\n", dev, uio);
    712 #endif
    713 	return(physio(ccdstrategy, NULL, dev, B_READ, minphys, uio));
    714 }
    715 
    716 ccdwrite(dev, uio)
    717 	dev_t dev;
    718 	struct uio *uio;
    719 {
    720 	register int unit = ccdunit(dev);
    721 
    722 #ifdef DEBUG
    723 	if (ccddebug & CCDB_FOLLOW)
    724 		printf("ccdwrite(%x, %x)\n", dev, uio);
    725 #endif
    726 	return(physio(ccdstrategy, NULL, dev, B_WRITE, minphys, uio));
    727 }
    728 
    729 ccdioctl(dev, cmd, data, flag)
    730 	dev_t dev;
    731 	u_long cmd;
    732 	caddr_t data;
    733 	int flag;
    734 {
    735 	return(EINVAL);
    736 }
    737 
    738 ccdsize(dev)
    739 	dev_t dev;
    740 {
    741 	int unit = ccdunit(dev);
    742 	register struct ccd_softc *cs = &ccd_softc[unit];
    743 
    744 	if (unit >= numccd || (cs->sc_flags & CCDF_INITED) == 0)
    745 		return(-1);
    746 	return(cs->sc_size);
    747 }
    748 
    749 ccddump(dev)
    750 {
    751 	return(ENXIO);
    752 }
    753 #endif
    754