xref: /netbsd-src/sys/dev/ld.c (revision d90047b5d07facf36e6c01dcc0bded8997ce9cc2)
1 /*	$NetBSD: ld.c,v 1.110 2020/04/13 08:05:02 maxv Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran and Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Disk driver for use by RAID controllers.
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: ld.c,v 1.110 2020/04/13 08:05:02 maxv Exp $");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/device.h>
43 #include <sys/queue.h>
44 #include <sys/proc.h>
45 #include <sys/buf.h>
46 #include <sys/bufq.h>
47 #include <sys/endian.h>
48 #include <sys/disklabel.h>
49 #include <sys/disk.h>
50 #include <sys/dkio.h>
51 #include <sys/stat.h>
52 #include <sys/conf.h>
53 #include <sys/fcntl.h>
54 #include <sys/vnode.h>
55 #include <sys/syslog.h>
56 #include <sys/mutex.h>
57 #include <sys/module.h>
58 #include <sys/reboot.h>
59 
60 #include <dev/ldvar.h>
61 
62 #include "ioconf.h"
63 
64 static void	ldminphys(struct buf *bp);
65 static bool	ld_suspend(device_t, const pmf_qual_t *);
66 static bool	ld_shutdown(device_t, int);
67 static int	ld_diskstart(device_t, struct buf *bp);
68 static void	ld_iosize(device_t, int *);
69 static int	ld_dumpblocks(device_t, void *, daddr_t, int);
70 static void	ld_fake_geometry(struct ld_softc *);
71 static void	ld_set_geometry(struct ld_softc *);
72 static void	ld_config_interrupts (device_t);
73 static int	ld_lastclose(device_t);
74 static int	ld_discard(device_t, off_t, off_t);
75 static int	ld_flush(device_t, bool);
76 
77 static dev_type_open(ldopen);
78 static dev_type_close(ldclose);
79 static dev_type_read(ldread);
80 static dev_type_write(ldwrite);
81 static dev_type_ioctl(ldioctl);
82 static dev_type_strategy(ldstrategy);
83 static dev_type_dump(lddump);
84 static dev_type_size(ldsize);
85 static dev_type_discard(lddiscard);
86 
87 const struct bdevsw ld_bdevsw = {
88 	.d_open = ldopen,
89 	.d_close = ldclose,
90 	.d_strategy = ldstrategy,
91 	.d_ioctl = ldioctl,
92 	.d_dump = lddump,
93 	.d_psize = ldsize,
94 	.d_discard = lddiscard,
95 	.d_flag = D_DISK | D_MPSAFE
96 };
97 
98 const struct cdevsw ld_cdevsw = {
99 	.d_open = ldopen,
100 	.d_close = ldclose,
101 	.d_read = ldread,
102 	.d_write = ldwrite,
103 	.d_ioctl = ldioctl,
104 	.d_stop = nostop,
105 	.d_tty = notty,
106 	.d_poll = nopoll,
107 	.d_mmap = nommap,
108 	.d_kqfilter = nokqfilter,
109 	.d_discard = lddiscard,
110 	.d_flag = D_DISK | D_MPSAFE
111 };
112 
113 static const struct	dkdriver lddkdriver = {
114 	.d_open = ldopen,
115 	.d_close = ldclose,
116 	.d_strategy = ldstrategy,
117 	.d_iosize = ld_iosize,
118 	.d_minphys  = ldminphys,
119 	.d_diskstart = ld_diskstart,
120 	.d_dumpblocks = ld_dumpblocks,
121 	.d_lastclose = ld_lastclose,
122 	.d_discard = ld_discard
123 };
124 
125 void
126 ldattach(struct ld_softc *sc, const char *default_strategy)
127 {
128 	device_t self = sc->sc_dv;
129 	struct dk_softc *dksc = &sc->sc_dksc;
130 
131 	mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM);
132 	cv_init(&sc->sc_drain, "lddrain");
133 
134 	if ((sc->sc_flags & LDF_ENABLED) == 0) {
135 		return;
136 	}
137 
138 	/* don't attach a disk that we cannot handle */
139 	if (sc->sc_secsize < DEV_BSIZE) {
140 		sc->sc_flags &= ~LDF_ENABLED;
141 		return;
142 	}
143 
144 	/* Initialise dk and disk structure. */
145 	dk_init(dksc, self, DKTYPE_LD);
146 	disk_init(&dksc->sc_dkdev, dksc->sc_xname, &lddkdriver);
147 
148 	if (sc->sc_maxxfer > MAXPHYS)
149 		sc->sc_maxxfer = MAXPHYS;
150 
151 	/* Build synthetic geometry if necessary. */
152 	if (sc->sc_nheads == 0 || sc->sc_nsectors == 0 ||
153 	    sc->sc_ncylinders == 0)
154 	    ld_fake_geometry(sc);
155 
156 	sc->sc_disksize512 = sc->sc_secperunit * sc->sc_secsize / DEV_BSIZE;
157 
158 	if (sc->sc_flags & LDF_NO_RND)
159 		dksc->sc_flags |= DKF_NO_RND;
160 
161 	/* Attach dk and disk subsystems */
162 	dk_attach(dksc);
163 	disk_attach(&dksc->sc_dkdev);
164 	ld_set_geometry(sc);
165 
166 	bufq_alloc(&dksc->sc_bufq, default_strategy, BUFQ_SORT_RAWBLOCK);
167 
168 	/* Register with PMF */
169 	if (!pmf_device_register1(dksc->sc_dev, ld_suspend, NULL, ld_shutdown))
170 		aprint_error_dev(dksc->sc_dev,
171 		    "couldn't establish power handler\n");
172 
173 	/* Discover wedges on this disk. */
174 	config_interrupts(sc->sc_dv, ld_config_interrupts);
175 }
176 
177 int
178 ldadjqparam(struct ld_softc *sc, int xmax)
179 {
180 
181 	mutex_enter(&sc->sc_mutex);
182 	sc->sc_maxqueuecnt = xmax;
183 	mutex_exit(&sc->sc_mutex);
184 
185 	return (0);
186 }
187 
188 int
189 ldbegindetach(struct ld_softc *sc, int flags)
190 {
191 	struct dk_softc *dksc = &sc->sc_dksc;
192 	int rv = 0;
193 
194 	if ((sc->sc_flags & LDF_ENABLED) == 0)
195 		return (0);
196 
197 	rv = disk_begindetach(&dksc->sc_dkdev, ld_lastclose, dksc->sc_dev, flags);
198 
199 	if (rv != 0)
200 		return rv;
201 
202 	mutex_enter(&sc->sc_mutex);
203 	sc->sc_maxqueuecnt = 0;
204 
205 	while (sc->sc_queuecnt > 0) {
206 		sc->sc_flags |= LDF_DRAIN;
207 		cv_wait(&sc->sc_drain, &sc->sc_mutex);
208 	}
209 	mutex_exit(&sc->sc_mutex);
210 
211 	return (rv);
212 }
213 
214 void
215 ldenddetach(struct ld_softc *sc)
216 {
217 	struct dk_softc *dksc = &sc->sc_dksc;
218 	int bmaj, cmaj, i, mn;
219 
220 	if ((sc->sc_flags & LDF_ENABLED) == 0)
221 		return;
222 
223 	mutex_enter(&sc->sc_mutex);
224 
225 	/* Wait for commands queued with the hardware to complete. */
226 	if (sc->sc_queuecnt != 0) {
227 		if (cv_timedwait(&sc->sc_drain, &sc->sc_mutex, 30 * hz))
228 			printf("%s: not drained\n", dksc->sc_xname);
229 	}
230 	mutex_exit(&sc->sc_mutex);
231 
232 	/* Kill off any queued buffers. */
233 	dk_drain(dksc);
234 	bufq_free(dksc->sc_bufq);
235 
236 	/* Locate the major numbers. */
237 	bmaj = bdevsw_lookup_major(&ld_bdevsw);
238 	cmaj = cdevsw_lookup_major(&ld_cdevsw);
239 
240 	/* Nuke the vnodes for any open instances. */
241 	for (i = 0; i < MAXPARTITIONS; i++) {
242 		mn = DISKMINOR(device_unit(dksc->sc_dev), i);
243 		vdevgone(bmaj, mn, mn, VBLK);
244 		vdevgone(cmaj, mn, mn, VCHR);
245 	}
246 
247 	/* Delete all of our wedges. */
248 	dkwedge_delall(&dksc->sc_dkdev);
249 
250 	/* Detach from the disk list. */
251 	disk_detach(&dksc->sc_dkdev);
252 	disk_destroy(&dksc->sc_dkdev);
253 
254 	dk_detach(dksc);
255 
256 	/* Deregister with PMF */
257 	pmf_device_deregister(dksc->sc_dev);
258 
259 	/*
260 	 * XXX We can't really flush the cache here, because the
261 	 * XXX device may already be non-existent from the controller's
262 	 * XXX perspective.
263 	 */
264 #if 0
265 	ld_flush(dksc->sc_dev, false);
266 #endif
267 	cv_destroy(&sc->sc_drain);
268 	mutex_destroy(&sc->sc_mutex);
269 }
270 
271 /* ARGSUSED */
272 static bool
273 ld_suspend(device_t dev, const pmf_qual_t *qual)
274 {
275 	return ld_shutdown(dev, 0);
276 }
277 
278 /* ARGSUSED */
279 static bool
280 ld_shutdown(device_t dev, int flags)
281 {
282 	if ((flags & RB_NOSYNC) == 0 && ld_flush(dev, true) != 0)
283 		return false;
284 
285 	return true;
286 }
287 
288 /* ARGSUSED */
289 static int
290 ldopen(dev_t dev, int flags, int fmt, struct lwp *l)
291 {
292 	struct ld_softc *sc;
293 	struct dk_softc *dksc;
294 	int unit;
295 
296 	unit = DISKUNIT(dev);
297 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
298 		return (ENXIO);
299 
300 	if ((sc->sc_flags & LDF_ENABLED) == 0)
301 		return (ENODEV);
302 
303 	dksc = &sc->sc_dksc;
304 
305 	return dk_open(dksc, dev, flags, fmt, l);
306 }
307 
308 static int
309 ld_lastclose(device_t self)
310 {
311 	ld_flush(self, false);
312 
313 	return 0;
314 }
315 
316 /* ARGSUSED */
317 static int
318 ldclose(dev_t dev, int flags, int fmt, struct lwp *l)
319 {
320 	struct ld_softc *sc;
321 	struct dk_softc *dksc;
322 	int unit;
323 
324 	unit = DISKUNIT(dev);
325 	sc = device_lookup_private(&ld_cd, unit);
326 	dksc = &sc->sc_dksc;
327 
328 	return dk_close(dksc, dev, flags, fmt, l);
329 }
330 
331 /* ARGSUSED */
332 static int
333 ldread(dev_t dev, struct uio *uio, int ioflag)
334 {
335 
336 	return (physio(ldstrategy, NULL, dev, B_READ, ldminphys, uio));
337 }
338 
339 /* ARGSUSED */
340 static int
341 ldwrite(dev_t dev, struct uio *uio, int ioflag)
342 {
343 
344 	return (physio(ldstrategy, NULL, dev, B_WRITE, ldminphys, uio));
345 }
346 
347 /* ARGSUSED */
348 static int
349 ldioctl(dev_t dev, u_long cmd, void *addr, int32_t flag, struct lwp *l)
350 {
351 	struct ld_softc *sc;
352 	struct dk_softc *dksc;
353 	int unit, error;
354 
355 	unit = DISKUNIT(dev);
356 	sc = device_lookup_private(&ld_cd, unit);
357 	dksc = &sc->sc_dksc;
358 
359 	error = 0;
360 
361 	/*
362 	 * Some common checks so that individual attachments wouldn't need
363 	 * to duplicate them.
364 	 */
365 	switch (cmd) {
366 	case DIOCCACHESYNC:
367 		/*
368 		 * XXX Do we really need to care about having a writable
369 		 * file descriptor here?
370 		 */
371 		if ((flag & FWRITE) == 0)
372 			error = EBADF;
373 		else
374 			error = 0;
375 		break;
376 	}
377 
378 	if (error != 0)
379 		return (error);
380 
381 	if (sc->sc_ioctl) {
382 		if ((sc->sc_flags & LDF_MPSAFE) == 0)
383 			KERNEL_LOCK(1, curlwp);
384 		error = (*sc->sc_ioctl)(sc, cmd, addr, flag, 0);
385 		if ((sc->sc_flags & LDF_MPSAFE) == 0)
386 			KERNEL_UNLOCK_ONE(curlwp);
387 		if (error != EPASSTHROUGH)
388 			return (error);
389 	}
390 
391 	/* something not handled by the attachment */
392 	return dk_ioctl(dksc, dev, cmd, addr, flag, l);
393 }
394 
395 /*
396  * Flush the device's cache.
397  */
398 static int
399 ld_flush(device_t self, bool poll)
400 {
401 	int error = 0;
402 	struct ld_softc *sc = device_private(self);
403 
404 	if (sc->sc_ioctl) {
405 		if ((sc->sc_flags & LDF_MPSAFE) == 0)
406 			KERNEL_LOCK(1, curlwp);
407 		error = (*sc->sc_ioctl)(sc, DIOCCACHESYNC, NULL, 0, poll);
408 		if ((sc->sc_flags & LDF_MPSAFE) == 0)
409 			KERNEL_UNLOCK_ONE(curlwp);
410 		if (error != 0)
411 			device_printf(self, "unable to flush cache\n");
412 	}
413 
414 	return error;
415 }
416 
417 static void
418 ldstrategy(struct buf *bp)
419 {
420 	struct ld_softc *sc;
421 	struct dk_softc *dksc;
422 	int unit;
423 
424 	unit = DISKUNIT(bp->b_dev);
425 	sc = device_lookup_private(&ld_cd, unit);
426 	dksc = &sc->sc_dksc;
427 
428 	dk_strategy(dksc, bp);
429 }
430 
431 static int
432 ld_diskstart(device_t dev, struct buf *bp)
433 {
434 	struct ld_softc *sc = device_private(dev);
435 	int error;
436 
437 	if (sc->sc_queuecnt >= sc->sc_maxqueuecnt)
438 		return EAGAIN;
439 
440 	if ((sc->sc_flags & LDF_MPSAFE) == 0)
441 		KERNEL_LOCK(1, curlwp);
442 
443 	mutex_enter(&sc->sc_mutex);
444 
445 	if (sc->sc_queuecnt >= sc->sc_maxqueuecnt)
446 		error = EAGAIN;
447 	else {
448 		error = (*sc->sc_start)(sc, bp);
449 		if (error == 0)
450 			sc->sc_queuecnt++;
451 	}
452 
453 	mutex_exit(&sc->sc_mutex);
454 
455 	if ((sc->sc_flags & LDF_MPSAFE) == 0)
456 		KERNEL_UNLOCK_ONE(curlwp);
457 
458 	return error;
459 }
460 
461 void
462 lddone(struct ld_softc *sc, struct buf *bp)
463 {
464 	struct dk_softc *dksc = &sc->sc_dksc;
465 
466 	dk_done(dksc, bp);
467 
468 	mutex_enter(&sc->sc_mutex);
469 	if (--sc->sc_queuecnt <= sc->sc_maxqueuecnt) {
470 		if ((sc->sc_flags & LDF_DRAIN) != 0) {
471 			sc->sc_flags &= ~LDF_DRAIN;
472 			cv_broadcast(&sc->sc_drain);
473 		}
474 		mutex_exit(&sc->sc_mutex);
475 		dk_start(dksc, NULL);
476 	} else
477 		mutex_exit(&sc->sc_mutex);
478 }
479 
480 static int
481 ldsize(dev_t dev)
482 {
483 	struct ld_softc *sc;
484 	struct dk_softc *dksc;
485 	int unit;
486 
487 	unit = DISKUNIT(dev);
488 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
489 		return (-1);
490 	dksc = &sc->sc_dksc;
491 
492 	if ((sc->sc_flags & LDF_ENABLED) == 0)
493 		return (-1);
494 
495 	return dk_size(dksc, dev);
496 }
497 
498 /*
499  * Take a dump.
500  */
501 static int
502 lddump(dev_t dev, daddr_t blkno, void *va, size_t size)
503 {
504 	struct ld_softc *sc;
505 	struct dk_softc *dksc;
506 	int unit;
507 
508 	unit = DISKUNIT(dev);
509 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
510 		return (ENXIO);
511 	dksc = &sc->sc_dksc;
512 
513 	if ((sc->sc_flags & LDF_ENABLED) == 0)
514 		return (ENODEV);
515 
516 	return dk_dump(dksc, dev, blkno, va, size, 0);
517 }
518 
519 static int
520 ld_dumpblocks(device_t dev, void *va, daddr_t blkno, int nblk)
521 {
522 	struct ld_softc *sc = device_private(dev);
523 
524 	if (sc->sc_dump == NULL)
525 		return (ENODEV);
526 
527 	return (*sc->sc_dump)(sc, va, blkno, nblk);
528 }
529 
530 /*
531  * Adjust the size of a transfer.
532  */
533 static void
534 ldminphys(struct buf *bp)
535 {
536 	int unit;
537 	struct ld_softc *sc;
538 
539 	unit = DISKUNIT(bp->b_dev);
540 	sc = device_lookup_private(&ld_cd, unit);
541 
542 	ld_iosize(sc->sc_dv, &bp->b_bcount);
543 	minphys(bp);
544 }
545 
546 static void
547 ld_iosize(device_t d, int *countp)
548 {
549 	struct ld_softc *sc = device_private(d);
550 
551 	if (*countp > sc->sc_maxxfer)
552 		*countp = sc->sc_maxxfer;
553 }
554 
555 static void
556 ld_fake_geometry(struct ld_softc *sc)
557 {
558 	uint64_t ncyl;
559 
560 	if (sc->sc_secperunit <= 528 * 2048)		/* 528MB */
561 		sc->sc_nheads = 16;
562 	else if (sc->sc_secperunit <= 1024 * 2048)	/* 1GB */
563 		sc->sc_nheads = 32;
564 	else if (sc->sc_secperunit <= 21504 * 2048)	/* 21GB */
565 		sc->sc_nheads = 64;
566 	else if (sc->sc_secperunit <= 43008 * 2048)	/* 42GB */
567 		sc->sc_nheads = 128;
568 	else
569 		sc->sc_nheads = 255;
570 
571 	sc->sc_nsectors = 63;
572 	sc->sc_ncylinders = INT_MAX;
573 	ncyl = sc->sc_secperunit /
574 	    (sc->sc_nheads * sc->sc_nsectors);
575 	if (ncyl < INT_MAX)
576 		sc->sc_ncylinders = (int)ncyl;
577 }
578 
579 static void
580 ld_set_geometry(struct ld_softc *sc)
581 {
582 	struct dk_softc *dksc = &sc->sc_dksc;
583 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
584 	char tbuf[9];
585 
586 	format_bytes(tbuf, sizeof(tbuf), sc->sc_secperunit *
587 	    sc->sc_secsize);
588 	aprint_normal_dev(dksc->sc_dev, "%s, %d cyl, %d head, %d sec, "
589 	    "%d bytes/sect x %"PRIu64" sectors\n",
590 	    tbuf, sc->sc_ncylinders, sc->sc_nheads,
591 	    sc->sc_nsectors, sc->sc_secsize, sc->sc_secperunit);
592 
593 	memset(dg, 0, sizeof(*dg));
594 	dg->dg_secperunit = sc->sc_secperunit;
595 	dg->dg_secsize = sc->sc_secsize;
596 	dg->dg_nsectors = sc->sc_nsectors;
597 	dg->dg_ntracks = sc->sc_nheads;
598 	dg->dg_ncylinders = sc->sc_ncylinders;
599 
600 	disk_set_info(dksc->sc_dev, &dksc->sc_dkdev, sc->sc_typename);
601 }
602 
603 static void
604 ld_config_interrupts(device_t d)
605 {
606 	struct ld_softc *sc = device_private(d);
607 	struct dk_softc *dksc = &sc->sc_dksc;
608 
609 	dkwedge_discover(&dksc->sc_dkdev);
610 }
611 
612 static int
613 ld_discard(device_t dev, off_t pos, off_t len)
614 {
615 	struct ld_softc *sc = device_private(dev);
616 	struct buf dbuf, *bp = &dbuf;
617 	int error = 0;
618 
619 	KASSERT(len <= INT_MAX);
620 
621 	if (sc->sc_discard == NULL)
622 		return (ENODEV);
623 
624 	if ((sc->sc_flags & LDF_MPSAFE) == 0)
625 		KERNEL_LOCK(1, curlwp);
626 
627 	buf_init(bp);
628 	bp->b_vp = NULL;
629 	bp->b_data = NULL;
630 	bp->b_bufsize = 0;
631 	bp->b_rawblkno = pos / sc->sc_secsize;
632 	bp->b_bcount = len;
633 	bp->b_flags = B_WRITE;
634 	bp->b_cflags = BC_BUSY;
635 
636 	error = (*sc->sc_discard)(sc, bp);
637 	if (error == 0)
638 		error = biowait(bp);
639 
640 	buf_destroy(bp);
641 
642 	if ((sc->sc_flags & LDF_MPSAFE) == 0)
643 		KERNEL_UNLOCK_ONE(curlwp);
644 
645 	return error;
646 }
647 
648 void
649 lddiscardend(struct ld_softc *sc, struct buf *bp)
650 {
651 
652 	if (bp->b_error)
653 		bp->b_resid = bp->b_bcount;
654 	biodone(bp);
655 }
656 
657 static int
658 lddiscard(dev_t dev, off_t pos, off_t len)
659 {
660 	struct ld_softc *sc;
661 	struct dk_softc *dksc;
662 	int unit;
663 
664 	unit = DISKUNIT(dev);
665 	sc = device_lookup_private(&ld_cd, unit);
666 	dksc = &sc->sc_dksc;
667 
668 	return dk_discard(dksc, dev, pos, len);
669 }
670 
671 MODULE(MODULE_CLASS_DRIVER, ld, "dk_subr");
672 
673 #ifdef _MODULE
674 CFDRIVER_DECL(ld, DV_DISK, NULL);
675 #endif
676 
677 static int
678 ld_modcmd(modcmd_t cmd, void *opaque)
679 {
680 #ifdef _MODULE
681 	devmajor_t bmajor, cmajor;
682 #endif
683 	int error = 0;
684 
685 #ifdef _MODULE
686 	switch (cmd) {
687 	case MODULE_CMD_INIT:
688 		bmajor = cmajor = -1;
689 		error = devsw_attach(ld_cd.cd_name, &ld_bdevsw, &bmajor,
690 		    &ld_cdevsw, &cmajor);
691 		if (error)
692 			break;
693 		error = config_cfdriver_attach(&ld_cd);
694 		break;
695 	case MODULE_CMD_FINI:
696 		error = config_cfdriver_detach(&ld_cd);
697 		if (error)
698 			break;
699 		devsw_detach(&ld_bdevsw, &ld_cdevsw);
700 		break;
701 	default:
702 		error = ENOTTY;
703 		break;
704 	}
705 #endif
706 
707 	return error;
708 }
709