xref: /netbsd-src/sys/dev/ld.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: ld.c,v 1.64 2009/01/13 13:35:52 yamt 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 1.64 2009/01/13 13:35:52 yamt Exp $");
38 
39 #include "rnd.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/device.h>
45 #include <sys/queue.h>
46 #include <sys/proc.h>
47 #include <sys/buf.h>
48 #include <sys/bufq.h>
49 #include <sys/endian.h>
50 #include <sys/disklabel.h>
51 #include <sys/disk.h>
52 #include <sys/dkio.h>
53 #include <sys/stat.h>
54 #include <sys/conf.h>
55 #include <sys/fcntl.h>
56 #include <sys/vnode.h>
57 #include <sys/syslog.h>
58 #include <sys/mutex.h>
59 #if NRND > 0
60 #include <sys/rnd.h>
61 #endif
62 
63 #include <dev/ldvar.h>
64 
65 #include <prop/proplib.h>
66 
67 static void	ldgetdefaultlabel(struct ld_softc *, struct disklabel *);
68 static void	ldgetdisklabel(struct ld_softc *);
69 static void	ldminphys(struct buf *bp);
70 static bool	ld_shutdown(device_t, int);
71 static void	ldstart(struct ld_softc *, struct buf *);
72 static void	ld_set_properties(struct ld_softc *);
73 static void	ld_config_interrupts (struct device *);
74 
75 extern struct	cfdriver ld_cd;
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 
86 const struct bdevsw ld_bdevsw = {
87 	ldopen, ldclose, ldstrategy, ldioctl, lddump, ldsize, D_DISK
88 };
89 
90 const struct cdevsw ld_cdevsw = {
91 	ldopen, ldclose, ldread, ldwrite, ldioctl,
92 	nostop, notty, nopoll, nommap, nokqfilter, D_DISK
93 };
94 
95 static struct	dkdriver lddkdriver = { ldstrategy, ldminphys };
96 
97 void
98 ldattach(struct ld_softc *sc)
99 {
100 	char tbuf[9];
101 
102 	mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM);
103 
104 	if ((sc->sc_flags & LDF_ENABLED) == 0) {
105 		aprint_normal_dev(sc->sc_dv, "disabled\n");
106 		return;
107 	}
108 
109 	/* Initialise and attach the disk structure. */
110 	disk_init(&sc->sc_dk, device_xname(sc->sc_dv), &lddkdriver);
111 	disk_attach(&sc->sc_dk);
112 
113 	if (sc->sc_maxxfer > MAXPHYS)
114 		sc->sc_maxxfer = MAXPHYS;
115 
116 	/* Build synthetic geometry if necessary. */
117 	if (sc->sc_nheads == 0 || sc->sc_nsectors == 0 ||
118 	    sc->sc_ncylinders == 0) {
119 		uint64_t ncyl;
120 
121 		if (sc->sc_secperunit <= 528 * 2048)		/* 528MB */
122 			sc->sc_nheads = 16;
123 		else if (sc->sc_secperunit <= 1024 * 2048)	/* 1GB */
124 			sc->sc_nheads = 32;
125 		else if (sc->sc_secperunit <= 21504 * 2048)	/* 21GB */
126 			sc->sc_nheads = 64;
127 		else if (sc->sc_secperunit <= 43008 * 2048)	/* 42GB */
128 			sc->sc_nheads = 128;
129 		else
130 			sc->sc_nheads = 255;
131 
132 		sc->sc_nsectors = 63;
133 		sc->sc_ncylinders = INT_MAX;
134 		ncyl = sc->sc_secperunit /
135 		    (sc->sc_nheads * sc->sc_nsectors);
136 		if (ncyl < INT_MAX)
137 			sc->sc_ncylinders = (int)ncyl;
138 	}
139 
140 	format_bytes(tbuf, sizeof(tbuf), sc->sc_secperunit *
141 	    sc->sc_secsize);
142 	aprint_normal_dev(sc->sc_dv, "%s, %d cyl, %d head, %d sec, "
143 	    "%d bytes/sect x %"PRIu64" sectors\n",
144 	    tbuf, sc->sc_ncylinders, sc->sc_nheads,
145 	    sc->sc_nsectors, sc->sc_secsize, sc->sc_secperunit);
146 
147 	ld_set_properties(sc);
148 
149 #if NRND > 0
150 	/* Attach the device into the rnd source list. */
151 	rnd_attach_source(&sc->sc_rnd_source, device_xname(sc->sc_dv),
152 	    RND_TYPE_DISK, 0);
153 #endif
154 
155 	/* Register with PMF */
156 	if (!pmf_device_register1(sc->sc_dv, NULL, NULL, ld_shutdown))
157 		aprint_error_dev(sc->sc_dv,
158 		    "couldn't establish power handler\n");
159 
160 	bufq_alloc(&sc->sc_bufq, BUFQ_DISK_DEFAULT_STRAT, BUFQ_SORT_RAWBLOCK);
161 
162 	/* Discover wedges on this disk. */
163 	config_interrupts(sc->sc_dv, ld_config_interrupts);
164 }
165 
166 int
167 ldadjqparam(struct ld_softc *sc, int xmax)
168 {
169 	int s;
170 
171 	s = splbio();
172 	sc->sc_maxqueuecnt = xmax;
173 	splx(s);
174 
175 	return (0);
176 }
177 
178 int
179 ldbegindetach(struct ld_softc *sc, int flags)
180 {
181 	int s, rv = 0;
182 
183 	if ((sc->sc_flags & LDF_ENABLED) == 0)
184 		return (0);
185 
186 	if ((flags & DETACH_FORCE) == 0 && sc->sc_dk.dk_openmask != 0)
187 		return (EBUSY);
188 
189 	s = splbio();
190 	sc->sc_maxqueuecnt = 0;
191 	sc->sc_flags |= LDF_DETACH;
192 	while (sc->sc_queuecnt > 0) {
193 		sc->sc_flags |= LDF_DRAIN;
194 		rv = tsleep(&sc->sc_queuecnt, PRIBIO, "lddrn", 0);
195 		if (rv)
196 			break;
197 	}
198 	splx(s);
199 
200 	return (rv);
201 }
202 
203 void
204 ldenddetach(struct ld_softc *sc)
205 {
206 	int s, bmaj, cmaj, i, mn;
207 
208 	if ((sc->sc_flags & LDF_ENABLED) == 0)
209 		return;
210 
211 	/* Wait for commands queued with the hardware to complete. */
212 	if (sc->sc_queuecnt != 0)
213 		if (tsleep(&sc->sc_queuecnt, PRIBIO, "lddtch", 30 * hz))
214 			printf("%s: not drained\n", device_xname(sc->sc_dv));
215 
216 	/* Locate the major numbers. */
217 	bmaj = bdevsw_lookup_major(&ld_bdevsw);
218 	cmaj = cdevsw_lookup_major(&ld_cdevsw);
219 
220 	/* Kill off any queued buffers. */
221 	s = splbio();
222 	bufq_drain(sc->sc_bufq);
223 	splx(s);
224 
225 	bufq_free(sc->sc_bufq);
226 
227 	/* Nuke the vnodes for any open instances. */
228 	for (i = 0; i < MAXPARTITIONS; i++) {
229 		mn = DISKMINOR(device_unit(sc->sc_dv), i);
230 		vdevgone(bmaj, mn, mn, VBLK);
231 		vdevgone(cmaj, mn, mn, VCHR);
232 	}
233 
234 	/* Delete all of our wedges. */
235 	dkwedge_delall(&sc->sc_dk);
236 
237 	/* Detach from the disk list. */
238 	disk_detach(&sc->sc_dk);
239 	disk_destroy(&sc->sc_dk);
240 
241 #if NRND > 0
242 	/* Unhook the entropy source. */
243 	rnd_detach_source(&sc->sc_rnd_source);
244 #endif
245 
246 	/* Deregister with PMF */
247 	pmf_device_deregister(sc->sc_dv);
248 
249 	/*
250 	 * XXX We can't really flush the cache here, beceause the
251 	 * XXX device may already be non-existent from the controller's
252 	 * XXX perspective.
253 	 */
254 #if 0
255 	/* Flush the device's cache. */
256 	if (sc->sc_flush != NULL)
257 		if ((*sc->sc_flush)(sc, 0) != 0)
258 			aprint_error_dev(&sc->sc_dv, "unable to flush cache\n");
259 #endif
260 	mutex_destroy(&sc->sc_mutex);
261 }
262 
263 /* ARGSUSED */
264 static bool
265 ld_shutdown(device_t dev, int flags)
266 {
267 	struct ld_softc *sc = device_private(dev);
268 
269 	if (sc->sc_flush != NULL && (*sc->sc_flush)(sc, LDFL_POLL) != 0) {
270 		printf("%s: unable to flush cache\n", device_xname(dev));
271 		return false;
272 	}
273 
274 	return true;
275 }
276 
277 /* ARGSUSED */
278 static int
279 ldopen(dev_t dev, int flags, int fmt, struct lwp *l)
280 {
281 	struct ld_softc *sc;
282 	int error, unit, part;
283 
284 	unit = DISKUNIT(dev);
285 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
286 		return (ENXIO);
287 	if ((sc->sc_flags & LDF_ENABLED) == 0)
288 		return (ENODEV);
289 	part = DISKPART(dev);
290 
291 	mutex_enter(&sc->sc_dk.dk_openlock);
292 
293 	if (sc->sc_dk.dk_openmask == 0) {
294 		/* Load the partition info if not already loaded. */
295 		if ((sc->sc_flags & LDF_VLABEL) == 0)
296 			ldgetdisklabel(sc);
297 	}
298 
299 	/* Check that the partition exists. */
300 	if (part != RAW_PART && (part >= sc->sc_dk.dk_label->d_npartitions ||
301 	    sc->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
302 		error = ENXIO;
303 		goto bad1;
304 	}
305 
306 	/* Ensure only one open at a time. */
307 	switch (fmt) {
308 	case S_IFCHR:
309 		sc->sc_dk.dk_copenmask |= (1 << part);
310 		break;
311 	case S_IFBLK:
312 		sc->sc_dk.dk_bopenmask |= (1 << part);
313 		break;
314 	}
315 	sc->sc_dk.dk_openmask =
316 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
317 
318 	error = 0;
319  bad1:
320 	mutex_exit(&sc->sc_dk.dk_openlock);
321 	return (error);
322 }
323 
324 /* ARGSUSED */
325 static int
326 ldclose(dev_t dev, int flags, int fmt, struct lwp *l)
327 {
328 	struct ld_softc *sc;
329 	int part, unit;
330 
331 	unit = DISKUNIT(dev);
332 	part = DISKPART(dev);
333 	sc = device_lookup_private(&ld_cd, unit);
334 
335 	mutex_enter(&sc->sc_dk.dk_openlock);
336 
337 	switch (fmt) {
338 	case S_IFCHR:
339 		sc->sc_dk.dk_copenmask &= ~(1 << part);
340 		break;
341 	case S_IFBLK:
342 		sc->sc_dk.dk_bopenmask &= ~(1 << part);
343 		break;
344 	}
345 	sc->sc_dk.dk_openmask =
346 	    sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
347 
348 	if (sc->sc_dk.dk_openmask == 0) {
349 		if (sc->sc_flush != NULL && (*sc->sc_flush)(sc, 0) != 0)
350 			aprint_error_dev(sc->sc_dv, "unable to flush cache\n");
351 		if ((sc->sc_flags & LDF_KLABEL) == 0)
352 			sc->sc_flags &= ~LDF_VLABEL;
353 	}
354 
355 	mutex_exit(&sc->sc_dk.dk_openlock);
356 	return (0);
357 }
358 
359 /* ARGSUSED */
360 static int
361 ldread(dev_t dev, struct uio *uio, int ioflag)
362 {
363 
364 	return (physio(ldstrategy, NULL, dev, B_READ, ldminphys, uio));
365 }
366 
367 /* ARGSUSED */
368 static int
369 ldwrite(dev_t dev, struct uio *uio, int ioflag)
370 {
371 
372 	return (physio(ldstrategy, NULL, dev, B_WRITE, ldminphys, uio));
373 }
374 
375 /* ARGSUSED */
376 static int
377 ldioctl(dev_t dev, u_long cmd, void *addr, int32_t flag, struct lwp *l)
378 {
379 	struct ld_softc *sc;
380 	int part, unit, error;
381 #ifdef __HAVE_OLD_DISKLABEL
382 	struct disklabel newlabel;
383 #endif
384 	struct disklabel *lp;
385 
386 	unit = DISKUNIT(dev);
387 	part = DISKPART(dev);
388 	sc = device_lookup_private(&ld_cd, unit);
389 
390 	error = disk_ioctl(&sc->sc_dk, cmd, addr, flag, l);
391 	if (error != EPASSTHROUGH)
392 		return (error);
393 
394 	error = 0;
395 	switch (cmd) {
396 	case DIOCGDINFO:
397 		memcpy(addr, sc->sc_dk.dk_label, sizeof(struct disklabel));
398 		return (0);
399 
400 #ifdef __HAVE_OLD_DISKLABEL
401 	case ODIOCGDINFO:
402 		newlabel = *(sc->sc_dk.dk_label);
403 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
404 			return ENOTTY;
405 		memcpy(addr, &newlabel, sizeof(struct olddisklabel));
406 		return (0);
407 #endif
408 
409 	case DIOCGPART:
410 		((struct partinfo *)addr)->disklab = sc->sc_dk.dk_label;
411 		((struct partinfo *)addr)->part =
412 		    &sc->sc_dk.dk_label->d_partitions[part];
413 		break;
414 
415 	case DIOCWDINFO:
416 	case DIOCSDINFO:
417 #ifdef __HAVE_OLD_DISKLABEL
418 	case ODIOCWDINFO:
419 	case ODIOCSDINFO:
420 
421 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
422 			memset(&newlabel, 0, sizeof newlabel);
423 			memcpy(&newlabel, addr, sizeof (struct olddisklabel));
424 			lp = &newlabel;
425 		} else
426 #endif
427 		lp = (struct disklabel *)addr;
428 
429 		if ((flag & FWRITE) == 0)
430 			return (EBADF);
431 
432 		mutex_enter(&sc->sc_dk.dk_openlock);
433 		sc->sc_flags |= LDF_LABELLING;
434 
435 		error = setdisklabel(sc->sc_dk.dk_label,
436 		    lp, /*sc->sc_dk.dk_openmask : */0,
437 		    sc->sc_dk.dk_cpulabel);
438 		if (error == 0 && (cmd == DIOCWDINFO
439 #ifdef __HAVE_OLD_DISKLABEL
440 		    || cmd == ODIOCWDINFO
441 #endif
442 		    ))
443 			error = writedisklabel(
444 			    MAKEDISKDEV(major(dev), DISKUNIT(dev), RAW_PART),
445 			    ldstrategy, sc->sc_dk.dk_label,
446 			    sc->sc_dk.dk_cpulabel);
447 
448 		sc->sc_flags &= ~LDF_LABELLING;
449 		mutex_exit(&sc->sc_dk.dk_openlock);
450 		break;
451 
452 	case DIOCKLABEL:
453 		if ((flag & FWRITE) == 0)
454 			return (EBADF);
455 		if (*(int *)addr)
456 			sc->sc_flags |= LDF_KLABEL;
457 		else
458 			sc->sc_flags &= ~LDF_KLABEL;
459 		break;
460 
461 	case DIOCWLABEL:
462 		if ((flag & FWRITE) == 0)
463 			return (EBADF);
464 		if (*(int *)addr)
465 			sc->sc_flags |= LDF_WLABEL;
466 		else
467 			sc->sc_flags &= ~LDF_WLABEL;
468 		break;
469 
470 	case DIOCGDEFLABEL:
471 		ldgetdefaultlabel(sc, (struct disklabel *)addr);
472 		break;
473 
474 #ifdef __HAVE_OLD_DISKLABEL
475 	case ODIOCGDEFLABEL:
476 		ldgetdefaultlabel(sc, &newlabel);
477 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
478 			return ENOTTY;
479 		memcpy(addr, &newlabel, sizeof (struct olddisklabel));
480 		break;
481 #endif
482 
483 	case DIOCCACHESYNC:
484 		/*
485 		 * XXX Do we really need to care about having a writable
486 		 * file descriptor here?
487 		 */
488 		if ((flag & FWRITE) == 0)
489 			error = EBADF;
490 		else if (sc->sc_flush)
491 			error = (*sc->sc_flush)(sc, 0);
492 		else
493 			error = 0;	/* XXX Error out instead? */
494 		break;
495 
496 	case DIOCAWEDGE:
497 	    {
498 	    	struct dkwedge_info *dkw = (void *) addr;
499 
500 		if ((flag & FWRITE) == 0)
501 			return (EBADF);
502 
503 		/* If the ioctl happens here, the parent is us. */
504 		strlcpy(dkw->dkw_parent, device_xname(sc->sc_dv),
505 			sizeof(dkw->dkw_parent));
506 		return (dkwedge_add(dkw));
507 	    }
508 
509 	case DIOCDWEDGE:
510 	    {
511 	    	struct dkwedge_info *dkw = (void *) addr;
512 
513 		if ((flag & FWRITE) == 0)
514 			return (EBADF);
515 
516 		/* If the ioctl happens here, the parent is us. */
517 		strlcpy(dkw->dkw_parent, device_xname(sc->sc_dv),
518 			sizeof(dkw->dkw_parent));
519 		return (dkwedge_del(dkw));
520 	    }
521 
522 	case DIOCLWEDGES:
523 	    {
524 	    	struct dkwedge_list *dkwl = (void *) addr;
525 
526 		return (dkwedge_list(&sc->sc_dk, dkwl, l));
527 	    }
528 	case DIOCGSTRATEGY:
529 	    {
530 		struct disk_strategy *dks = (void *)addr;
531 
532 		mutex_enter(&sc->sc_mutex);
533 		strlcpy(dks->dks_name, bufq_getstrategyname(sc->sc_bufq),
534 		    sizeof(dks->dks_name));
535 		mutex_exit(&sc->sc_mutex);
536 		dks->dks_paramlen = 0;
537 
538 		return 0;
539 	    }
540 	case DIOCSSTRATEGY:
541 	    {
542 		struct disk_strategy *dks = (void *)addr;
543 		struct bufq_state *new, *old;
544 
545 		if ((flag & FWRITE) == 0)
546 			return EPERM;
547 
548 		if (dks->dks_param != NULL)
549 			return EINVAL;
550 
551 		dks->dks_name[sizeof(dks->dks_name) - 1] = 0; /* ensure term */
552 		error = bufq_alloc(&new, dks->dks_name,
553 		    BUFQ_EXACT|BUFQ_SORT_RAWBLOCK);
554 		if (error)
555 			return error;
556 
557 		mutex_enter(&sc->sc_mutex);
558 		old = sc->sc_bufq;
559 		bufq_move(new, old);
560 		sc->sc_bufq = new;
561 		mutex_exit(&sc->sc_mutex);
562 		bufq_free(old);
563 
564 		return 0;
565 	    }
566 	default:
567 		error = ENOTTY;
568 		break;
569 	}
570 
571 	return (error);
572 }
573 
574 static void
575 ldstrategy(struct buf *bp)
576 {
577 	struct ld_softc *sc;
578 	struct disklabel *lp;
579 	daddr_t blkno;
580 	int s, part;
581 
582 	sc = device_lookup_private(&ld_cd, DISKUNIT(bp->b_dev));
583 	part = DISKPART(bp->b_dev);
584 
585 	if ((sc->sc_flags & LDF_DETACH) != 0) {
586 		bp->b_error = EIO;
587 		goto done;
588 	}
589 
590 	lp = sc->sc_dk.dk_label;
591 
592 	/*
593 	 * The transfer must be a whole number of blocks and the offset must
594 	 * not be negative.
595 	 */
596 	if ((bp->b_bcount % lp->d_secsize) != 0 || bp->b_blkno < 0) {
597 		bp->b_error = EINVAL;
598 		goto done;
599 	}
600 
601 	/* If it's a null transfer, return immediately. */
602 	if (bp->b_bcount == 0)
603 		goto done;
604 
605 	/*
606 	 * Do bounds checking and adjust the transfer.  If error, process.
607 	 * If past the end of partition, just return.
608 	 */
609 	if (part != RAW_PART &&
610 	    bounds_check_with_label(&sc->sc_dk, bp,
611 	    (sc->sc_flags & (LDF_WLABEL | LDF_LABELLING)) != 0) <= 0) {
612 		goto done;
613 	}
614 
615 	/*
616 	 * Convert the block number to absolute and put it in terms
617 	 * of the device's logical block size.
618 	 */
619 	if (lp->d_secsize == DEV_BSIZE)
620 		blkno = bp->b_blkno;
621 	else if (lp->d_secsize > DEV_BSIZE)
622 		blkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
623 	else
624 		blkno = bp->b_blkno * (DEV_BSIZE / lp->d_secsize);
625 
626 	if (part != RAW_PART)
627 		blkno += lp->d_partitions[part].p_offset;
628 
629 	bp->b_rawblkno = blkno;
630 
631 	s = splbio();
632 	ldstart(sc, bp);
633 	splx(s);
634 	return;
635 
636  done:
637 	bp->b_resid = bp->b_bcount;
638 	biodone(bp);
639 }
640 
641 static void
642 ldstart(struct ld_softc *sc, struct buf *bp)
643 {
644 	int error;
645 
646 	mutex_enter(&sc->sc_mutex);
647 
648 	if (bp != NULL)
649 		bufq_put(sc->sc_bufq, bp);
650 
651 	while (sc->sc_queuecnt < sc->sc_maxqueuecnt) {
652 		/* See if there is work to do. */
653 		if ((bp = bufq_peek(sc->sc_bufq)) == NULL)
654 			break;
655 
656 		disk_busy(&sc->sc_dk);
657 		sc->sc_queuecnt++;
658 
659 		if (__predict_true((error = (*sc->sc_start)(sc, bp)) == 0)) {
660 			/*
661 			 * The back-end is running the job; remove it from
662 			 * the queue.
663 			 */
664 			(void) bufq_get(sc->sc_bufq);
665 		} else  {
666 			disk_unbusy(&sc->sc_dk, 0, (bp->b_flags & B_READ));
667 			sc->sc_queuecnt--;
668 			if (error == EAGAIN) {
669 				/*
670 				 * Temporary resource shortage in the
671 				 * back-end; just defer the job until
672 				 * later.
673 				 *
674 				 * XXX We might consider a watchdog timer
675 				 * XXX to make sure we are kicked into action.
676 				 */
677 				break;
678 			} else {
679 				(void) bufq_get(sc->sc_bufq);
680 				bp->b_error = error;
681 				bp->b_resid = bp->b_bcount;
682 				mutex_exit(&sc->sc_mutex);
683 				biodone(bp);
684 				mutex_enter(&sc->sc_mutex);
685 			}
686 		}
687 	}
688 
689 	mutex_exit(&sc->sc_mutex);
690 }
691 
692 void
693 lddone(struct ld_softc *sc, struct buf *bp)
694 {
695 
696 	if (bp->b_error != 0) {
697 		diskerr(bp, "ld", "error", LOG_PRINTF, 0, sc->sc_dk.dk_label);
698 		printf("\n");
699 	}
700 
701 	disk_unbusy(&sc->sc_dk, bp->b_bcount - bp->b_resid,
702 	    (bp->b_flags & B_READ));
703 #if NRND > 0
704 	rnd_add_uint32(&sc->sc_rnd_source, bp->b_rawblkno);
705 #endif
706 	biodone(bp);
707 
708 	mutex_enter(&sc->sc_mutex);
709 	if (--sc->sc_queuecnt <= sc->sc_maxqueuecnt) {
710 		if ((sc->sc_flags & LDF_DRAIN) != 0) {
711 			sc->sc_flags &= ~LDF_DRAIN;
712 			wakeup(&sc->sc_queuecnt);
713 		}
714 		mutex_exit(&sc->sc_mutex);
715 		ldstart(sc, NULL);
716 	} else
717 		mutex_exit(&sc->sc_mutex);
718 }
719 
720 static int
721 ldsize(dev_t dev)
722 {
723 	struct ld_softc *sc;
724 	int part, unit, omask, size;
725 
726 	unit = DISKUNIT(dev);
727 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
728 		return (ENODEV);
729 	if ((sc->sc_flags & LDF_ENABLED) == 0)
730 		return (ENODEV);
731 	part = DISKPART(dev);
732 
733 	omask = sc->sc_dk.dk_openmask & (1 << part);
734 
735 	if (omask == 0 && ldopen(dev, 0, S_IFBLK, NULL) != 0)
736 		return (-1);
737 	else if (sc->sc_dk.dk_label->d_partitions[part].p_fstype != FS_SWAP)
738 		size = -1;
739 	else
740 		size = sc->sc_dk.dk_label->d_partitions[part].p_size *
741 		    (sc->sc_dk.dk_label->d_secsize / DEV_BSIZE);
742 	if (omask == 0 && ldclose(dev, 0, S_IFBLK, NULL) != 0)
743 		return (-1);
744 
745 	return (size);
746 }
747 
748 /*
749  * Load the label information from the specified device.
750  */
751 static void
752 ldgetdisklabel(struct ld_softc *sc)
753 {
754 	const char *errstring;
755 
756 	ldgetdefaultlabel(sc, sc->sc_dk.dk_label);
757 
758 	/* Call the generic disklabel extraction routine. */
759 	errstring = readdisklabel(MAKEDISKDEV(0, device_unit(sc->sc_dv),
760 	    RAW_PART), ldstrategy, sc->sc_dk.dk_label, sc->sc_dk.dk_cpulabel);
761 	if (errstring != NULL)
762 		printf("%s: %s\n", device_xname(sc->sc_dv), errstring);
763 
764 	/* In-core label now valid. */
765 	sc->sc_flags |= LDF_VLABEL;
766 }
767 
768 /*
769  * Construct a ficticious label.
770  */
771 static void
772 ldgetdefaultlabel(struct ld_softc *sc, struct disklabel *lp)
773 {
774 
775 	memset(lp, 0, sizeof(struct disklabel));
776 
777 	lp->d_secsize = sc->sc_secsize;
778 	lp->d_ntracks = sc->sc_nheads;
779 	lp->d_nsectors = sc->sc_nsectors;
780 	lp->d_ncylinders = sc->sc_ncylinders;
781 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
782 	lp->d_type = DTYPE_LD;
783 	strlcpy(lp->d_typename, "unknown", sizeof(lp->d_typename));
784 	strlcpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
785 	lp->d_secperunit = sc->sc_secperunit;
786 	lp->d_rpm = 7200;
787 	lp->d_interleave = 1;
788 	lp->d_flags = 0;
789 
790 	lp->d_partitions[RAW_PART].p_offset = 0;
791 	lp->d_partitions[RAW_PART].p_size =
792 	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
793 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
794 	lp->d_npartitions = RAW_PART + 1;
795 
796 	lp->d_magic = DISKMAGIC;
797 	lp->d_magic2 = DISKMAGIC;
798 	lp->d_checksum = dkcksum(lp);
799 }
800 
801 /*
802  * Take a dump.
803  */
804 static int
805 lddump(dev_t dev, daddr_t blkno, void *vav, size_t size)
806 {
807 	char *va = vav;
808 	struct ld_softc *sc;
809 	struct disklabel *lp;
810 	int unit, part, nsects, sectoff, towrt, nblk, maxblkcnt, rv;
811 	static int dumping;
812 
813 	unit = DISKUNIT(dev);
814 	if ((sc = device_lookup_private(&ld_cd, unit)) == NULL)
815 		return (ENXIO);
816 	if ((sc->sc_flags & LDF_ENABLED) == 0)
817 		return (ENODEV);
818 	if (sc->sc_dump == NULL)
819 		return (ENXIO);
820 
821 	/* Check if recursive dump; if so, punt. */
822 	if (dumping)
823 		return (EFAULT);
824 	dumping = 1;
825 
826 	/* Convert to disk sectors.  Request must be a multiple of size. */
827 	part = DISKPART(dev);
828 	lp = sc->sc_dk.dk_label;
829 	if ((size % lp->d_secsize) != 0)
830 		return (EFAULT);
831 	towrt = size / lp->d_secsize;
832 	blkno = dbtob(blkno) / lp->d_secsize;	/* blkno in DEV_BSIZE units */
833 
834 	nsects = lp->d_partitions[part].p_size;
835 	sectoff = lp->d_partitions[part].p_offset;
836 
837 	/* Check transfer bounds against partition size. */
838 	if ((blkno < 0) || ((blkno + towrt) > nsects))
839 		return (EINVAL);
840 
841 	/* Offset block number to start of partition. */
842 	blkno += sectoff;
843 
844 	/* Start dumping and return when done. */
845 	maxblkcnt = sc->sc_maxxfer / sc->sc_secsize - 1;
846 	while (towrt > 0) {
847 		nblk = min(maxblkcnt, towrt);
848 
849 		if ((rv = (*sc->sc_dump)(sc, va, blkno, nblk)) != 0)
850 			return (rv);
851 
852 		towrt -= nblk;
853 		blkno += nblk;
854 		va += nblk * sc->sc_secsize;
855 	}
856 
857 	dumping = 0;
858 	return (0);
859 }
860 
861 /*
862  * Adjust the size of a transfer.
863  */
864 static void
865 ldminphys(struct buf *bp)
866 {
867 	struct ld_softc *sc;
868 
869 	sc = device_lookup_private(&ld_cd, DISKUNIT(bp->b_dev));
870 
871 	if (bp->b_bcount > sc->sc_maxxfer)
872 		bp->b_bcount = sc->sc_maxxfer;
873 	minphys(bp);
874 }
875 
876 static void
877 ld_set_properties(struct ld_softc *ld)
878 {
879 	prop_dictionary_t disk_info, odisk_info, geom;
880 
881 	disk_info = prop_dictionary_create();
882 
883 	geom = prop_dictionary_create();
884 
885 	prop_dictionary_set_uint64(geom, "sectors-per-unit",
886 	    ld->sc_secperunit);
887 
888 	prop_dictionary_set_uint32(geom, "sector-size",
889 	    ld->sc_secsize);
890 
891 	prop_dictionary_set_uint16(geom, "sectors-per-track",
892 	    ld->sc_nsectors);
893 
894 	prop_dictionary_set_uint16(geom, "tracks-per-cylinder",
895 	    ld->sc_nheads);
896 
897 	prop_dictionary_set_uint64(geom, "cylinders-per-unit",
898 	    ld->sc_ncylinders);
899 
900 	prop_dictionary_set(disk_info, "geometry", geom);
901 	prop_object_release(geom);
902 
903 	prop_dictionary_set(device_properties(ld->sc_dv),
904 	    "disk-info", disk_info);
905 
906 	/*
907 	 * Don't release disk_info here; we keep a reference to it.
908 	 * disk_detach() will release it when we go away.
909 	 */
910 
911 	odisk_info = ld->sc_dk.dk_info;
912 	ld->sc_dk.dk_info = disk_info;
913 	if (odisk_info)
914 		prop_object_release(odisk_info);
915 }
916 
917 static void
918 ld_config_interrupts (struct device *d)
919 {
920 	struct ld_softc *sc = device_private(d);
921 	dkwedge_discover(&sc->sc_dk);
922 }
923