xref: /netbsd-src/sys/dev/scsipi/sd.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: sd.c,v 1.164 2000/07/05 23:31:13 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Originally written by Julian Elischer (julian@dialix.oz.au)
41  * for TRW Financial Systems for use under the MACH(2.5) operating system.
42  *
43  * TRW Financial Systems, in accordance with their agreement with Carnegie
44  * Mellon University, makes this software available to CMU to distribute
45  * or use in any manner that they see fit as long as this message is kept with
46  * the software. For this reason TFS also grants any other persons or
47  * organisations permission to use or modify this software.
48  *
49  * TFS supplies this software to be publicly redistributed
50  * on the understanding that TFS is not responsible for the correct
51  * functioning of this software in any circumstances.
52  *
53  * Ported to run under 386BSD by Julian Elischer (julian@dialix.oz.au) Sept 1992
54  */
55 
56 #include "opt_scsi.h"
57 #include "rnd.h"
58 
59 #include <sys/types.h>
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/kernel.h>
63 #include <sys/file.h>
64 #include <sys/stat.h>
65 #include <sys/ioctl.h>
66 #include <sys/scsiio.h>
67 #include <sys/buf.h>
68 #include <sys/uio.h>
69 #include <sys/malloc.h>
70 #include <sys/errno.h>
71 #include <sys/device.h>
72 #include <sys/disklabel.h>
73 #include <sys/disk.h>
74 #include <sys/proc.h>
75 #include <sys/conf.h>
76 #include <sys/vnode.h>
77 #if NRND > 0
78 #include <sys/rnd.h>
79 #endif
80 
81 #include <dev/scsipi/scsipi_all.h>
82 #include <dev/scsipi/scsi_all.h>
83 #include <dev/scsipi/scsipi_disk.h>
84 #include <dev/scsipi/scsi_disk.h>
85 #include <dev/scsipi/scsiconf.h>
86 #include <dev/scsipi/sdvar.h>
87 
88 #include "sd.h"		/* NSD_SCSIBUS and NSD_ATAPIBUS come from here */
89 
90 #ifndef	SDOUTSTANDING
91 #define	SDOUTSTANDING	4
92 #endif
93 
94 #define	SDUNIT(dev)			DISKUNIT(dev)
95 #define	SDPART(dev)			DISKPART(dev)
96 #define	SDMINOR(unit, part)		DISKMINOR(unit, part)
97 #define	MAKESDDEV(maj, unit, part)	MAKEDISKDEV(maj, unit, part)
98 
99 #define	SDLABELDEV(dev)	(MAKESDDEV(major(dev), SDUNIT(dev), RAW_PART))
100 
101 int	sdlock __P((struct sd_softc *));
102 void	sdunlock __P((struct sd_softc *));
103 void	sdminphys __P((struct buf *));
104 void	sdgetdefaultlabel __P((struct sd_softc *, struct disklabel *));
105 void	sdgetdisklabel __P((struct sd_softc *));
106 void	sdstart __P((void *));
107 void	sddone __P((struct scsipi_xfer *));
108 void	sd_shutdown __P((void *));
109 int	sd_reassign_blocks __P((struct sd_softc *, u_long));
110 int	sd_interpret_sense __P((struct scsipi_xfer *));
111 
112 extern struct cfdriver sd_cd;
113 
114 struct dkdriver sddkdriver = { sdstrategy };
115 
116 struct scsipi_device sd_switch = {
117 	sd_interpret_sense,	/* check our error handler first */
118 	sdstart,		/* have a queue, served by this */
119 	NULL,			/* have no async handler */
120 	sddone,			/* deal with stats at interrupt time */
121 };
122 
123 /*
124  * The routine called by the low level scsi routine when it discovers
125  * a device suitable for this driver.
126  */
127 void
128 sdattach(parent, sd, sc_link, ops)
129 	struct device *parent;
130 	struct sd_softc *sd;
131 	struct scsipi_link *sc_link;
132 	const struct sd_ops *ops;
133 {
134 	int error, result;
135 	struct disk_parms *dp = &sd->params;
136 	char pbuf[9];
137 
138 	SC_DEBUG(sc_link, SDEV_DB2, ("sdattach: "));
139 
140 	BUFQ_INIT(&sd->buf_queue);
141 
142 	/*
143 	 * Store information needed to contact our base driver
144 	 */
145 	sd->sc_link = sc_link;
146 	sd->sc_ops = ops;
147 	sc_link->device = &sd_switch;
148 	sc_link->device_softc = sd;
149 	if (sc_link->openings > SDOUTSTANDING)
150 		sc_link->openings = SDOUTSTANDING;
151 
152 	/*
153 	 * Initialize and attach the disk structure.
154 	 */
155 	sd->sc_dk.dk_driver = &sddkdriver;
156 	sd->sc_dk.dk_name = sd->sc_dev.dv_xname;
157 	disk_attach(&sd->sc_dk);
158 
159 #ifdef __BROKEN_DK_ESTABLISH
160 	dk_establish(&sd->sc_dk, &sd->sc_dev);		/* XXX */
161 #endif
162 
163 	/*
164 	 * Use the subdriver to request information regarding
165 	 * the drive. We cannot use interrupts yet, so the
166 	 * request must specify this.
167 	 */
168 	printf("\n");
169 
170 	error = scsipi_start(sd->sc_link, SSS_START,
171 	    XS_CTL_DISCOVERY | XS_CTL_IGNORE_ILLEGAL_REQUEST |
172 	    XS_CTL_IGNORE_MEDIA_CHANGE | XS_CTL_SILENT);
173 
174 	if (error)
175 		result = SDGP_RESULT_OFFLINE;
176 	else
177 		result = (*sd->sc_ops->sdo_get_parms)(sd, &sd->params,
178 		    XS_CTL_DISCOVERY);
179 	printf("%s: ", sd->sc_dev.dv_xname);
180 	switch (result) {
181 	case SDGP_RESULT_OK:
182 		format_bytes(pbuf, sizeof(pbuf),
183 		    (u_int64_t)dp->disksize * dp->blksize);
184 	        printf(
185 		"%s, %ld cyl, %ld head, %ld sec, %ld bytes/sect x %ld sectors",
186 		    pbuf, dp->cyls, dp->heads, dp->sectors, dp->blksize,
187 		    dp->disksize);
188 		break;
189 
190 	case SDGP_RESULT_OFFLINE:
191 		printf("drive offline");
192 		break;
193 
194 	case SDGP_RESULT_UNFORMATTED:
195 		printf("unformatted media");
196 		break;
197 
198 #ifdef DIAGNOSTIC
199 	default:
200 		panic("sdattach: unknown result from get_parms");
201 		break;
202 #endif
203 	}
204 	printf("\n");
205 
206 	/*
207 	 * Establish a shutdown hook so that we can ensure that
208 	 * our data has actually made it onto the platter at
209 	 * shutdown time.  Note that this relies on the fact
210 	 * that the shutdown hook code puts us at the head of
211 	 * the list (thus guaranteeing that our hook runs before
212 	 * our ancestors').
213 	 */
214 	if ((sd->sc_sdhook =
215 	    shutdownhook_establish(sd_shutdown, sd)) == NULL)
216 		printf("%s: WARNING: unable to establish shutdown hook\n",
217 		    sd->sc_dev.dv_xname);
218 
219 #if NRND > 0
220 	/*
221 	 * attach the device into the random source list
222 	 */
223 	rnd_attach_source(&sd->rnd_source, sd->sc_dev.dv_xname,
224 			  RND_TYPE_DISK, 0);
225 #endif
226 }
227 
228 int
229 sdactivate(self, act)
230 	struct device *self;
231 	enum devact act;
232 {
233 	int rv = 0;
234 
235 	switch (act) {
236 	case DVACT_ACTIVATE:
237 		rv = EOPNOTSUPP;
238 		break;
239 
240 	case DVACT_DEACTIVATE:
241 		/*
242 		 * Nothing to do; we key off the device's DVF_ACTIVE.
243 		 */
244 		break;
245 	}
246 	return (rv);
247 }
248 
249 int
250 sddetach(self, flags)
251 	struct device *self;
252 	int flags;
253 {
254 	struct sd_softc *sd = (struct sd_softc *) self;
255 	struct buf *bp;
256 	int s, bmaj, cmaj, mn;
257 
258 	/* locate the major number */
259 	for (bmaj = 0; bmaj <= nblkdev; bmaj++)
260 		if (bdevsw[bmaj].d_open == sdopen)
261 			break;
262 	for (cmaj = 0; cmaj <= nchrdev; cmaj++)
263 		if (cdevsw[cmaj].d_open == sdopen)
264 			break;
265 
266 	s = splbio();
267 
268 	/* Kill off any queued buffers. */
269 	while ((bp = BUFQ_FIRST(&sd->buf_queue)) != NULL) {
270 		BUFQ_REMOVE(&sd->buf_queue, bp);
271 		bp->b_error = EIO;
272 		bp->b_flags |= B_ERROR;
273 		bp->b_resid = bp->b_bcount;
274 		biodone(bp);
275 	}
276 
277 	/* Kill off any pending commands. */
278 	scsipi_kill_pending(sd->sc_link);
279 
280 	splx(s);
281 
282 	/* Nuke the vnodes for any open instances */
283 	mn = SDMINOR(self->dv_unit, 0);
284 	vdevgone(bmaj, mn, mn + (MAXPARTITIONS - 1), VBLK);
285 	vdevgone(cmaj, mn, mn + (MAXPARTITIONS - 1), VCHR);
286 
287 	/* Detach from the disk list. */
288 	disk_detach(&sd->sc_dk);
289 
290 	/* Get rid of the shutdown hook. */
291 	shutdownhook_disestablish(sd->sc_sdhook);
292 
293 #if NRND > 0
294 	/* Unhook the entropy source. */
295 	rnd_detach_source(&sd->rnd_source);
296 #endif
297 
298 	return (0);
299 }
300 
301 /*
302  * Wait interruptibly for an exclusive lock.
303  *
304  * XXX
305  * Several drivers do this; it should be abstracted and made MP-safe.
306  */
307 int
308 sdlock(sd)
309 	struct sd_softc *sd;
310 {
311 	int error;
312 
313 	while ((sd->flags & SDF_LOCKED) != 0) {
314 		sd->flags |= SDF_WANTED;
315 		if ((error = tsleep(sd, PRIBIO | PCATCH, "sdlck", 0)) != 0)
316 			return (error);
317 	}
318 	sd->flags |= SDF_LOCKED;
319 	return (0);
320 }
321 
322 /*
323  * Unlock and wake up any waiters.
324  */
325 void
326 sdunlock(sd)
327 	struct sd_softc *sd;
328 {
329 
330 	sd->flags &= ~SDF_LOCKED;
331 	if ((sd->flags & SDF_WANTED) != 0) {
332 		sd->flags &= ~SDF_WANTED;
333 		wakeup(sd);
334 	}
335 }
336 
337 /*
338  * open the device. Make sure the partition info is a up-to-date as can be.
339  */
340 int
341 sdopen(dev, flag, fmt, p)
342 	dev_t dev;
343 	int flag, fmt;
344 	struct proc *p;
345 {
346 	struct sd_softc *sd;
347 	struct scsipi_link *sc_link;
348 	int unit, part;
349 	int error;
350 
351 	unit = SDUNIT(dev);
352 	if (unit >= sd_cd.cd_ndevs)
353 		return (ENXIO);
354 	sd = sd_cd.cd_devs[unit];
355 	if (sd == NULL)
356 		return (ENXIO);
357 
358 	if ((sd->sc_dev.dv_flags & DVF_ACTIVE) == 0)
359 		return (ENODEV);
360 
361 	sc_link = sd->sc_link;
362 	part = SDPART(dev);
363 
364 	SC_DEBUG(sc_link, SDEV_DB1,
365 	    ("sdopen: dev=0x%x (unit %d (of %d), partition %d)\n", dev, unit,
366 	    sd_cd.cd_ndevs, part));
367 
368 	/*
369 	 * If this is the first open of this device, add a reference
370 	 * to the adapter.
371 	 */
372 	if (sd->sc_dk.dk_openmask == 0 &&
373 	    (error = scsipi_adapter_addref(sc_link)) != 0)
374 		return (error);
375 
376 	if ((error = sdlock(sd)) != 0)
377 		goto bad4;
378 
379 	if ((sc_link->flags & SDEV_OPEN) != 0) {
380 		/*
381 		 * If any partition is open, but the disk has been invalidated,
382 		 * disallow further opens of non-raw partition
383 		 */
384 		if ((sc_link->flags & SDEV_MEDIA_LOADED) == 0 &&
385 		    (part != RAW_PART || fmt != S_IFCHR)) {
386 			error = EIO;
387 			goto bad3;
388 		}
389 	} else {
390 		/* Check that it is still responding and ok. */
391 		error = scsipi_test_unit_ready(sc_link,
392 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_MEDIA_CHANGE |
393 		    XS_CTL_IGNORE_NOT_READY);
394 		if (error)
395 			goto bad3;
396 
397 		/*
398 		 * Start the pack spinning if necessary. Always allow the
399 		 * raw parition to be opened, for raw IOCTLs. Data transfers
400 		 * will check for SDEV_MEDIA_LOADED.
401 		 */
402 		error = scsipi_start(sc_link, SSS_START,
403 		    XS_CTL_IGNORE_ILLEGAL_REQUEST |
404 		    XS_CTL_IGNORE_MEDIA_CHANGE | XS_CTL_SILENT);
405 		if (error) {
406 			if (part != RAW_PART || fmt != S_IFCHR)
407 				goto bad3;
408 			else
409 				goto out;
410 		}
411 
412 		sc_link->flags |= SDEV_OPEN;
413 
414 		/* Lock the pack in. */
415 		error = scsipi_prevent(sc_link, PR_PREVENT,
416 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_MEDIA_CHANGE);
417 		if (error)
418 			goto bad;
419 
420 		if ((sc_link->flags & SDEV_MEDIA_LOADED) == 0) {
421 			sc_link->flags |= SDEV_MEDIA_LOADED;
422 
423 			/*
424 			 * Load the physical device parameters.
425 			 *
426 			 * Note that if media is present but unformatted,
427 			 * we allow the open (so that it can be formatted!).
428 			 * The drive should refuse real I/O, if the media is
429 			 * unformatted.
430 			 */
431 			if ((*sd->sc_ops->sdo_get_parms)(sd, &sd->params,
432 			    0) == SDGP_RESULT_OFFLINE) {
433 				error = ENXIO;
434 				goto bad2;
435 			}
436 			SC_DEBUG(sc_link, SDEV_DB3, ("Params loaded "));
437 
438 			/* Load the partition info if not already loaded. */
439 			sdgetdisklabel(sd);
440 			SC_DEBUG(sc_link, SDEV_DB3, ("Disklabel loaded "));
441 		}
442 	}
443 
444 	/* Check that the partition exists. */
445 	if (part != RAW_PART &&
446 	    (part >= sd->sc_dk.dk_label->d_npartitions ||
447 	     sd->sc_dk.dk_label->d_partitions[part].p_fstype == FS_UNUSED)) {
448 		error = ENXIO;
449 		goto bad;
450 	}
451 
452 out:	/* Insure only one open at a time. */
453 	switch (fmt) {
454 	case S_IFCHR:
455 		sd->sc_dk.dk_copenmask |= (1 << part);
456 		break;
457 	case S_IFBLK:
458 		sd->sc_dk.dk_bopenmask |= (1 << part);
459 		break;
460 	}
461 	sd->sc_dk.dk_openmask =
462 	    sd->sc_dk.dk_copenmask | sd->sc_dk.dk_bopenmask;
463 
464 	SC_DEBUG(sc_link, SDEV_DB3, ("open complete\n"));
465 	sdunlock(sd);
466 	return (0);
467 
468 bad2:
469 	sc_link->flags &= ~SDEV_MEDIA_LOADED;
470 
471 bad:
472 	if (sd->sc_dk.dk_openmask == 0) {
473 		scsipi_prevent(sc_link, PR_ALLOW,
474 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_MEDIA_CHANGE);
475 		sc_link->flags &= ~SDEV_OPEN;
476 	}
477 
478 bad3:
479 	sdunlock(sd);
480 bad4:
481 	if (sd->sc_dk.dk_openmask == 0)
482 		scsipi_adapter_delref(sc_link);
483 	return (error);
484 }
485 
486 /*
487  * close the device.. only called if we are the LAST occurence of an open
488  * device.  Convenient now but usually a pain.
489  */
490 int
491 sdclose(dev, flag, fmt, p)
492 	dev_t dev;
493 	int flag, fmt;
494 	struct proc *p;
495 {
496 	struct sd_softc *sd = sd_cd.cd_devs[SDUNIT(dev)];
497 	int part = SDPART(dev);
498 	int error;
499 
500 	if ((error = sdlock(sd)) != 0)
501 		return (error);
502 
503 	switch (fmt) {
504 	case S_IFCHR:
505 		sd->sc_dk.dk_copenmask &= ~(1 << part);
506 		break;
507 	case S_IFBLK:
508 		sd->sc_dk.dk_bopenmask &= ~(1 << part);
509 		break;
510 	}
511 	sd->sc_dk.dk_openmask =
512 	    sd->sc_dk.dk_copenmask | sd->sc_dk.dk_bopenmask;
513 
514 	if (sd->sc_dk.dk_openmask == 0) {
515 		/*
516 		 * If the disk cache needs flushing, and the disk supports
517 		 * it, do it now.
518 		 */
519 		if ((sd->flags & SDF_DIRTY) != 0 &&
520 		    sd->sc_ops->sdo_flush != NULL) {
521 			if ((*sd->sc_ops->sdo_flush)(sd, 0)) {
522 				printf("%s: cache synchronization failed\n",
523 				    sd->sc_dev.dv_xname);
524 				sd->flags &= ~SDF_FLUSHING;
525 			} else
526 				sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
527 		}
528 
529 		scsipi_wait_drain(sd->sc_link);
530 
531 		scsipi_prevent(sd->sc_link, PR_ALLOW,
532 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
533 		sd->sc_link->flags &= ~SDEV_OPEN;
534 
535 		if (! (sd->sc_link->flags & SDEV_KEEP_LABEL))
536 			sd->sc_link->flags &= ~SDEV_MEDIA_LOADED;
537 
538 		scsipi_wait_drain(sd->sc_link);
539 
540 		scsipi_adapter_delref(sd->sc_link);
541 	}
542 
543 	sdunlock(sd);
544 	return (0);
545 }
546 
547 /*
548  * Actually translate the requested transfer into one the physical driver
549  * can understand.  The transfer is described by a buf and will include
550  * only one physical transfer.
551  */
552 void
553 sdstrategy(bp)
554 	struct buf *bp;
555 {
556 	struct sd_softc *sd = sd_cd.cd_devs[SDUNIT(bp->b_dev)];
557 	struct disklabel *lp;
558 	daddr_t blkno;
559 	int s;
560 
561 	SC_DEBUG(sd->sc_link, SDEV_DB2, ("sdstrategy "));
562 	SC_DEBUG(sd->sc_link, SDEV_DB1,
563 	    ("%ld bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
564 	/*
565 	 * If the device has been made invalid, error out
566 	 */
567 	if ((sd->sc_link->flags & SDEV_MEDIA_LOADED) == 0 ||
568 	    (sd->sc_dev.dv_flags & DVF_ACTIVE) == 0) {
569 		if (sd->sc_link->flags & SDEV_OPEN)
570 			bp->b_error = EIO;
571 		else
572 			bp->b_error = ENODEV;
573 		goto bad;
574 	}
575 
576 	lp = sd->sc_dk.dk_label;
577 
578 	/*
579 	 * The transfer must be a whole number of blocks, offset must not be
580 	 * negative.
581 	 */
582 	if ((bp->b_bcount % lp->d_secsize) != 0 ||
583 	    bp->b_blkno < 0) {
584 		bp->b_error = EINVAL;
585 		goto bad;
586 	}
587 	/*
588 	 * If it's a null transfer, return immediatly
589 	 */
590 	if (bp->b_bcount == 0)
591 		goto done;
592 
593 	/*
594 	 * Do bounds checking, adjust transfer. if error, process.
595 	 * If end of partition, just return.
596 	 */
597 	if (SDPART(bp->b_dev) != RAW_PART &&
598 	    bounds_check_with_label(bp, lp,
599 	    (sd->flags & (SDF_WLABEL|SDF_LABELLING)) != 0) <= 0)
600 		goto done;
601 
602 	/*
603 	 * Now convert the block number to absolute and put it in
604 	 * terms of the device's logical block size.
605 	 */
606 	if (lp->d_secsize >= DEV_BSIZE)
607 		blkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
608 	else
609 		blkno = bp->b_blkno * (DEV_BSIZE / lp->d_secsize);
610 
611 	if (SDPART(bp->b_dev) != RAW_PART)
612 		blkno += lp->d_partitions[SDPART(bp->b_dev)].p_offset;
613 
614 	bp->b_rawblkno = blkno;
615 
616 	s = splbio();
617 
618 	/*
619 	 * Place it in the queue of disk activities for this disk
620 	 */
621 	disksort_blkno(&sd->buf_queue, bp);
622 
623 	/*
624 	 * Tell the device to get going on the transfer if it's
625 	 * not doing anything, otherwise just wait for completion
626 	 */
627 	sdstart(sd);
628 
629 	splx(s);
630 	return;
631 
632 bad:
633 	bp->b_flags |= B_ERROR;
634 done:
635 	/*
636 	 * Correctly set the buf to indicate a completed xfer
637 	 */
638 	bp->b_resid = bp->b_bcount;
639 	biodone(bp);
640 }
641 
642 /*
643  * sdstart looks to see if there is a buf waiting for the device
644  * and that the device is not already busy. If both are true,
645  * It dequeues the buf and creates a scsi command to perform the
646  * transfer in the buf. The transfer request will call scsipi_done
647  * on completion, which will in turn call this routine again
648  * so that the next queued transfer is performed.
649  * The bufs are queued by the strategy routine (sdstrategy)
650  *
651  * This routine is also called after other non-queued requests
652  * have been made of the scsi driver, to ensure that the queue
653  * continues to be drained.
654  *
655  * must be called at the correct (highish) spl level
656  * sdstart() is called at splbio from sdstrategy and scsipi_done
657  */
658 void
659 sdstart(v)
660 	void *v;
661 {
662 	struct sd_softc *sd = v;
663 	struct scsipi_link *sc_link = sd->sc_link;
664 	struct disklabel *lp = sd->sc_dk.dk_label;
665 	struct buf *bp = 0;
666 	struct scsipi_rw_big cmd_big;
667 #if NSD_SCSIBUS > 0
668 	struct scsi_rw cmd_small;
669 #endif
670 	struct scsipi_generic *cmdp;
671 	int nblks, cmdlen, error;
672 
673 	SC_DEBUG(sc_link, SDEV_DB2, ("sdstart "));
674 	/*
675 	 * Check if the device has room for another command
676 	 */
677 	while (sc_link->active < sc_link->openings) {
678 		/*
679 		 * there is excess capacity, but a special waits
680 		 * It'll need the adapter as soon as we clear out of the
681 		 * way and let it run (user level wait).
682 		 */
683 		if (sc_link->flags & SDEV_WAITING) {
684 			sc_link->flags &= ~SDEV_WAITING;
685 			wakeup((caddr_t)sc_link);
686 			return;
687 		}
688 
689 		/*
690 		 * See if there is a buf with work for us to do..
691 		 */
692 		if ((bp = BUFQ_FIRST(&sd->buf_queue)) == NULL)
693 			return;
694 		BUFQ_REMOVE(&sd->buf_queue, bp);
695 
696 		/*
697 		 * If the device has become invalid, abort all the
698 		 * reads and writes until all files have been closed and
699 		 * re-opened
700 		 */
701 		if ((sc_link->flags & SDEV_MEDIA_LOADED) == 0) {
702 			bp->b_error = EIO;
703 			bp->b_flags |= B_ERROR;
704 			bp->b_resid = bp->b_bcount;
705 			biodone(bp);
706 			continue;
707 		}
708 
709 		/*
710 		 * We have a buf, now we should make a command.
711 		 */
712 
713 		nblks = howmany(bp->b_bcount, lp->d_secsize);
714 
715 #if NSD_SCSIBUS > 0
716 		/*
717 		 *  Fill out the scsi command.  If the transfer will
718 		 *  fit in a "small" cdb, use it.
719 		 */
720 		if (((bp->b_rawblkno & 0x1fffff) == bp->b_rawblkno) &&
721 		    ((nblks & 0xff) == nblks) && sc_link->type == BUS_SCSI &&
722 		    !(sc_link->quirks & SDEV_ONLYBIG)) {
723 			/*
724 			 * We can fit in a small cdb.
725 			 */
726 			bzero(&cmd_small, sizeof(cmd_small));
727 			cmd_small.opcode = (bp->b_flags & B_READ) ?
728 			    SCSI_READ_COMMAND : SCSI_WRITE_COMMAND;
729 			_lto3b(bp->b_rawblkno, cmd_small.addr);
730 			cmd_small.length = nblks & 0xff;
731 			cmdlen = sizeof(cmd_small);
732 			cmdp = (struct scsipi_generic *)&cmd_small;
733 		} else
734 #endif
735 		{
736 			/*
737 			 * Need a large cdb.
738 			 */
739 			bzero(&cmd_big, sizeof(cmd_big));
740 			cmd_big.opcode = (bp->b_flags & B_READ) ?
741 			    READ_BIG : WRITE_BIG;
742 			_lto4b(bp->b_rawblkno, cmd_big.addr);
743 			_lto2b(nblks, cmd_big.length);
744 			cmdlen = sizeof(cmd_big);
745 			cmdp = (struct scsipi_generic *)&cmd_big;
746 		}
747 
748 		/* Instrumentation. */
749 		disk_busy(&sd->sc_dk);
750 
751 		/*
752 		 * Mark the disk dirty so that the cache will be
753 		 * flushed on close.
754 		 */
755 		if ((bp->b_flags & B_READ) == 0)
756 			sd->flags |= SDF_DIRTY;
757 
758 		/*
759 		 * Call the routine that chats with the adapter.
760 		 * Note: we cannot sleep as we may be an interrupt
761 		 * XXX Really need NOSLEEP?
762 		 */
763 		error = scsipi_command(sc_link, cmdp, cmdlen,
764 		    (u_char *)bp->b_data, bp->b_bcount,
765 		    SDRETRIES, 60000, bp, XS_CTL_NOSLEEP | XS_CTL_ASYNC |
766 		    ((bp->b_flags & B_READ) ?
767 		     XS_CTL_DATA_IN : XS_CTL_DATA_OUT));
768 		if (error) {
769 			disk_unbusy(&sd->sc_dk, 0);
770 			printf("%s: not queued, error %d\n",
771 			    sd->sc_dev.dv_xname, error);
772 		}
773 	}
774 }
775 
776 void
777 sddone(xs)
778 	struct scsipi_xfer *xs;
779 {
780 	struct sd_softc *sd = xs->sc_link->device_softc;
781 
782 	if (sd->flags & SDF_FLUSHING) {
783 		/* Flush completed, no longer dirty. */
784 		sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
785 	}
786 	if (sd->flags & SDF_RESTART) {
787 		sd->flags &= ~SDF_RESTART;
788 		return;
789 	}
790 
791 	if (xs->bp != NULL) {
792 		disk_unbusy(&sd->sc_dk, xs->bp->b_bcount - xs->bp->b_resid);
793 #if NRND > 0
794 		rnd_add_uint32(&sd->rnd_source, xs->bp->b_rawblkno);
795 #endif
796 	}
797 }
798 
799 void
800 sdminphys(bp)
801 	struct buf *bp;
802 {
803 	struct sd_softc *sd = sd_cd.cd_devs[SDUNIT(bp->b_dev)];
804 	long max;
805 
806 	/*
807 	 * If the device is ancient, we want to make sure that
808 	 * the transfer fits into a 6-byte cdb.
809 	 *
810 	 * XXX Note that the SCSI-I spec says that 256-block transfers
811 	 * are allowed in a 6-byte read/write, and are specified
812 	 * by settng the "length" to 0.  However, we're conservative
813 	 * here, allowing only 255-block transfers in case an
814 	 * ancient device gets confused by length == 0.  A length of 0
815 	 * in a 10-byte read/write actually means 0 blocks.
816 	 */
817 	if (sd->flags & SDF_ANCIENT) {
818 		max = sd->sc_dk.dk_label->d_secsize * 0xff;
819 
820 		if (bp->b_bcount > max)
821 			bp->b_bcount = max;
822 	}
823 
824 	(*sd->sc_link->adapter->scsipi_minphys)(bp);
825 }
826 
827 int
828 sdread(dev, uio, ioflag)
829 	dev_t dev;
830 	struct uio *uio;
831 	int ioflag;
832 {
833 
834 	return (physio(sdstrategy, NULL, dev, B_READ, sdminphys, uio));
835 }
836 
837 int
838 sdwrite(dev, uio, ioflag)
839 	dev_t dev;
840 	struct uio *uio;
841 	int ioflag;
842 {
843 
844 	return (physio(sdstrategy, NULL, dev, B_WRITE, sdminphys, uio));
845 }
846 
847 /*
848  * Perform special action on behalf of the user
849  * Knows about the internals of this device
850  */
851 int
852 sdioctl(dev, cmd, addr, flag, p)
853 	dev_t dev;
854 	u_long cmd;
855 	caddr_t addr;
856 	int flag;
857 	struct proc *p;
858 {
859 	struct sd_softc *sd = sd_cd.cd_devs[SDUNIT(dev)];
860 	int part = SDPART(dev);
861 	int error;
862 
863 	SC_DEBUG(sd->sc_link, SDEV_DB2, ("sdioctl 0x%lx ", cmd));
864 
865 	if ((sd->sc_dev.dv_flags & DVF_ACTIVE) == 0)
866 		return (ENODEV);
867 
868 	/*
869 	 * If the device is not valid, some IOCTLs can still be
870 	 * handled on the raw partition. Check this here.
871 	 */
872 	if ((sd->sc_link->flags & SDEV_MEDIA_LOADED) == 0) {
873 		switch (cmd) {
874 		case DIOCKLABEL:
875 		case DIOCWLABEL:
876 		case DIOCLOCK:
877 		case DIOCEJECT:
878 		case ODIOCEJECT:
879 		case SCIOCIDENTIFY:
880 		case OSCIOCIDENTIFY:
881 		case SCIOCCOMMAND:
882 		case SCIOCDEBUG:
883 			if (part == RAW_PART)
884 				break;
885 		/* FALLTHROUGH */
886 		default:
887 			if ((sd->sc_link->flags & SDEV_OPEN) == 0)
888 				return (ENODEV);
889 			else
890 				return (EIO);
891 		}
892 	}
893 
894 	switch (cmd) {
895 	case DIOCGDINFO:
896 		*(struct disklabel *)addr = *(sd->sc_dk.dk_label);
897 		return (0);
898 
899 	case DIOCGPART:
900 		((struct partinfo *)addr)->disklab = sd->sc_dk.dk_label;
901 		((struct partinfo *)addr)->part =
902 		    &sd->sc_dk.dk_label->d_partitions[part];
903 		return (0);
904 
905 	case DIOCWDINFO:
906 	case DIOCSDINFO:
907 		if ((flag & FWRITE) == 0)
908 			return (EBADF);
909 
910 		if ((error = sdlock(sd)) != 0)
911 			return (error);
912 		sd->flags |= SDF_LABELLING;
913 
914 		error = setdisklabel(sd->sc_dk.dk_label,
915 		    (struct disklabel *)addr, /*sd->sc_dk.dk_openmask : */0,
916 		    sd->sc_dk.dk_cpulabel);
917 		if (error == 0) {
918 			if (cmd == DIOCWDINFO)
919 				error = writedisklabel(SDLABELDEV(dev),
920 				    sdstrategy, sd->sc_dk.dk_label,
921 				    sd->sc_dk.dk_cpulabel);
922 		}
923 
924 		sd->flags &= ~SDF_LABELLING;
925 		sdunlock(sd);
926 		return (error);
927 
928 	case DIOCKLABEL:
929 		if (*(int *)addr)
930 			sd->sc_link->flags |= SDEV_KEEP_LABEL;
931 		else
932 			sd->sc_link->flags &= ~SDEV_KEEP_LABEL;
933 		return (0);
934 
935 	case DIOCWLABEL:
936 		if ((flag & FWRITE) == 0)
937 			return (EBADF);
938 		if (*(int *)addr)
939 			sd->flags |= SDF_WLABEL;
940 		else
941 			sd->flags &= ~SDF_WLABEL;
942 		return (0);
943 
944 	case DIOCLOCK:
945 		return (scsipi_prevent(sd->sc_link,
946 		    (*(int *)addr) ? PR_PREVENT : PR_ALLOW, 0));
947 
948 	case DIOCEJECT:
949 		if ((sd->sc_link->flags & SDEV_REMOVABLE) == 0)
950 			return (ENOTTY);
951 		if (*(int *)addr == 0) {
952 			/*
953 			 * Don't force eject: check that we are the only
954 			 * partition open. If so, unlock it.
955 			 */
956 			if ((sd->sc_dk.dk_openmask & ~(1 << part)) == 0 &&
957 			    sd->sc_dk.dk_bopenmask + sd->sc_dk.dk_copenmask ==
958 			    sd->sc_dk.dk_openmask) {
959 				error = scsipi_prevent(sd->sc_link, PR_ALLOW,
960 				    XS_CTL_IGNORE_NOT_READY);
961 				if (error)
962 					return (error);
963 			} else {
964 				return (EBUSY);
965 			}
966 		}
967 		/* FALLTHROUGH */
968 	case ODIOCEJECT:
969 		return ((sd->sc_link->flags & SDEV_REMOVABLE) == 0 ? ENOTTY :
970 		    scsipi_start(sd->sc_link, SSS_STOP|SSS_LOEJ, 0));
971 
972 	case DIOCGDEFLABEL:
973 		sdgetdefaultlabel(sd, (struct disklabel *)addr);
974 		return (0);
975 
976 	default:
977 		if (part != RAW_PART)
978 			return (ENOTTY);
979 		return (scsipi_do_ioctl(sd->sc_link, dev, cmd, addr, flag, p));
980 	}
981 
982 #ifdef DIAGNOSTIC
983 	panic("sdioctl: impossible");
984 #endif
985 }
986 
987 void
988 sdgetdefaultlabel(sd, lp)
989 	struct sd_softc *sd;
990 	struct disklabel *lp;
991 {
992 
993 	bzero(lp, sizeof(struct disklabel));
994 
995 	lp->d_secsize = sd->params.blksize;
996 	lp->d_ntracks = sd->params.heads;
997 	lp->d_nsectors = sd->params.sectors;
998 	lp->d_ncylinders = sd->params.cyls;
999 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
1000 
1001 	switch (sd->sc_link->type) {
1002 #if NSD_SCSIBUS > 0
1003 	    case BUS_SCSI:
1004 		lp->d_type = DTYPE_SCSI;
1005 		break;
1006 #endif
1007 #if NSD_ATAPIBUS > 0
1008 	    case BUS_ATAPI:
1009 		lp->d_type = DTYPE_ATAPI;
1010 		break;
1011 #endif
1012 	}
1013 	strncpy(lp->d_typename, sd->name, 16);
1014 	strncpy(lp->d_packname, "fictitious", 16);
1015 	lp->d_secperunit = sd->params.disksize;
1016 	lp->d_rpm = sd->params.rot_rate;
1017 	lp->d_interleave = 1;
1018 	lp->d_flags = 0;
1019 
1020 	lp->d_partitions[RAW_PART].p_offset = 0;
1021 	lp->d_partitions[RAW_PART].p_size =
1022 	    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
1023 	lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
1024 	lp->d_npartitions = RAW_PART + 1;
1025 
1026 	lp->d_magic = DISKMAGIC;
1027 	lp->d_magic2 = DISKMAGIC;
1028 	lp->d_checksum = dkcksum(lp);
1029 }
1030 
1031 
1032 /*
1033  * Load the label information on the named device
1034  */
1035 void
1036 sdgetdisklabel(sd)
1037 	struct sd_softc *sd;
1038 {
1039 	struct disklabel *lp = sd->sc_dk.dk_label;
1040 	char *errstring;
1041 
1042 	bzero(sd->sc_dk.dk_cpulabel, sizeof(struct cpu_disklabel));
1043 
1044 	sdgetdefaultlabel(sd, lp);
1045 
1046 	if (lp->d_secpercyl == 0) {
1047 		lp->d_secpercyl = 100;
1048 		/* as long as it's not 0 - readdisklabel divides by it (?) */
1049 	}
1050 
1051 	/*
1052 	 * Call the generic disklabel extraction routine
1053 	 */
1054 	errstring = readdisklabel(MAKESDDEV(0, sd->sc_dev.dv_unit, RAW_PART),
1055 	    sdstrategy, lp, sd->sc_dk.dk_cpulabel);
1056 	if (errstring) {
1057 		printf("%s: %s\n", sd->sc_dev.dv_xname, errstring);
1058 		return;
1059 	}
1060 }
1061 
1062 void
1063 sd_shutdown(arg)
1064 	void *arg;
1065 {
1066 	struct sd_softc *sd = arg;
1067 
1068 	/*
1069 	 * If the disk cache needs to be flushed, and the disk supports
1070 	 * it, flush it.  We're cold at this point, so we poll for
1071 	 * completion.
1072 	 */
1073 	if ((sd->flags & SDF_DIRTY) != 0 && sd->sc_ops->sdo_flush != NULL) {
1074 		if ((*sd->sc_ops->sdo_flush)(sd, XS_CTL_NOSLEEP|XS_CTL_POLL)) {
1075 			printf("%s: cache synchronization failed\n",
1076 			    sd->sc_dev.dv_xname);
1077 			sd->flags &= ~SDF_FLUSHING;
1078 		} else
1079 			sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
1080 	}
1081 }
1082 
1083 /*
1084  * Tell the device to map out a defective block
1085  */
1086 int
1087 sd_reassign_blocks(sd, blkno)
1088 	struct sd_softc *sd;
1089 	u_long blkno;
1090 {
1091 	struct scsi_reassign_blocks scsipi_cmd;
1092 	struct scsi_reassign_blocks_data rbdata;
1093 
1094 	bzero(&scsipi_cmd, sizeof(scsipi_cmd));
1095 	bzero(&rbdata, sizeof(rbdata));
1096 	scsipi_cmd.opcode = SCSI_REASSIGN_BLOCKS;
1097 
1098 	_lto2b(sizeof(rbdata.defect_descriptor[0]), rbdata.length);
1099 	_lto4b(blkno, rbdata.defect_descriptor[0].dlbaddr);
1100 
1101 	return (scsipi_command(sd->sc_link,
1102 	    (struct scsipi_generic *)&scsipi_cmd, sizeof(scsipi_cmd),
1103 	    (u_char *)&rbdata, sizeof(rbdata), SDRETRIES, 5000, NULL,
1104 	    XS_CTL_DATA_OUT | XS_CTL_DATA_ONSTACK));
1105 }
1106 
1107 /*
1108  * Check Errors
1109  */
1110 int
1111 sd_interpret_sense(xs)
1112 	struct scsipi_xfer *xs;
1113 {
1114 	struct scsipi_link *sc_link = xs->sc_link;
1115 	struct scsipi_sense_data *sense = &xs->sense.scsi_sense;
1116 	struct sd_softc *sd = sc_link->device_softc;
1117 	int retval = SCSIRET_CONTINUE;
1118 
1119 	/*
1120 	 * If the device is not open yet, let the generic code handle it.
1121 	 */
1122 	if ((sc_link->flags & SDEV_MEDIA_LOADED) == 0) {
1123 		return (retval);
1124 	}
1125 
1126 	/*
1127 	 * If it isn't a extended or extended/deferred error, let
1128 	 * the generic code handle it.
1129 	 */
1130 	if ((sense->error_code & SSD_ERRCODE) != 0x70 &&
1131 	    (sense->error_code & SSD_ERRCODE) != 0x71) {	/* DEFFERRED */
1132 		return (retval);
1133 	}
1134 
1135 	if ((sense->flags & SSD_KEY) == SKEY_NOT_READY &&
1136 	    sense->add_sense_code == 0x4) {
1137 		if (sense->add_sense_code_qual == 0x01)	{
1138 			printf("%s: ..is spinning up...waiting\n",
1139 			    sd->sc_dev.dv_xname);
1140 			/*
1141 			 * I really need a sdrestart function I can call here.
1142 			 */
1143 			delay(1000000 * 5);	/* 5 seconds */
1144 			retval = SCSIRET_RETRY;
1145 		} else if ((sense->add_sense_code_qual == 0x2) &&
1146 		    (sd->sc_link->quirks & SDEV_NOSTARTUNIT) == 0) {
1147 			if (sd->sc_link->flags & SDEV_REMOVABLE) {
1148 				printf(
1149 				"%s: removable disk stopped - not restarting\n",
1150 				    sd->sc_dev.dv_xname);
1151 				retval = EIO;
1152 			} else {
1153 				if (sd->flags & SDF_RESTART)
1154 					return SCSIRET_RETRY;
1155 				sd->flags |= SDF_RESTART;
1156 				printf("%s: respinning up disk\n",
1157 				    sd->sc_dev.dv_xname);
1158 				retval = scsipi_start(sd->sc_link, SSS_START,
1159 				    XS_CTL_URGENT | XS_CTL_NOSLEEP |
1160 				    ((xs->xs_control & XS_CTL_ASYNC) ?
1161 				    XS_CTL_ASYNC : 0));
1162 				if ((xs->xs_control & XS_CTL_ASYNC) == 0)
1163 					sd->flags &= ~SDF_RESTART;
1164 				if (retval != 0) {
1165 					printf(
1166 					    "%s: respin of disk failed - %d\n",
1167 					    sd->sc_dev.dv_xname, retval);
1168 					retval = EIO;
1169 				} else {
1170 					retval = SCSIRET_RETRY;
1171 				}
1172 			}
1173 		}
1174 	}
1175 	return (retval);
1176 }
1177 
1178 
1179 int
1180 sdsize(dev)
1181 	dev_t dev;
1182 {
1183 	struct sd_softc *sd;
1184 	int part, unit, omask;
1185 	int size;
1186 
1187 	unit = SDUNIT(dev);
1188 	if (unit >= sd_cd.cd_ndevs)
1189 		return (-1);
1190 	sd = sd_cd.cd_devs[unit];
1191 	if (sd == NULL)
1192 		return (-1);
1193 
1194 	if ((sd->sc_dev.dv_flags & DVF_ACTIVE) == 0)
1195 		return (-1);
1196 
1197 	part = SDPART(dev);
1198 	omask = sd->sc_dk.dk_openmask & (1 << part);
1199 
1200 	if (omask == 0 && sdopen(dev, 0, S_IFBLK, NULL) != 0)
1201 		return (-1);
1202 	if ((sd->sc_link->flags & SDEV_MEDIA_LOADED) == 0)
1203 		size = -1;
1204 	else if (sd->sc_dk.dk_label->d_partitions[part].p_fstype != FS_SWAP)
1205 		size = -1;
1206 	else
1207 		size = sd->sc_dk.dk_label->d_partitions[part].p_size *
1208 		    (sd->sc_dk.dk_label->d_secsize / DEV_BSIZE);
1209 	if (omask == 0 && sdclose(dev, 0, S_IFBLK, NULL) != 0)
1210 		return (-1);
1211 	return (size);
1212 }
1213 
1214 /* #define SD_DUMP_NOT_TRUSTED if you just want to watch */
1215 static struct scsipi_xfer sx;
1216 static int sddoingadump;
1217 
1218 /*
1219  * dump all of physical memory into the partition specified, starting
1220  * at offset 'dumplo' into the partition.
1221  */
1222 int
1223 sddump(dev, blkno, va, size)
1224 	dev_t dev;
1225 	daddr_t blkno;
1226 	caddr_t va;
1227 	size_t size;
1228 {
1229 	struct sd_softc *sd;	/* disk unit to do the I/O */
1230 	struct disklabel *lp;	/* disk's disklabel */
1231 	int	unit, part;
1232 	int	sectorsize;	/* size of a disk sector */
1233 	int	nsects;		/* number of sectors in partition */
1234 	int	sectoff;	/* sector offset of partition */
1235 	int	totwrt;		/* total number of sectors left to write */
1236 	int	nwrt;		/* current number of sectors to write */
1237 	struct scsipi_rw_big cmd;	/* write command */
1238 	struct scsipi_xfer *xs;	/* ... convenience */
1239 	int	retval;
1240 
1241 	/* Check if recursive dump; if so, punt. */
1242 	if (sddoingadump)
1243 		return (EFAULT);
1244 
1245 	/* Mark as active early. */
1246 	sddoingadump = 1;
1247 
1248 	unit = SDUNIT(dev);	/* Decompose unit & partition. */
1249 	part = SDPART(dev);
1250 
1251 	/* Check for acceptable drive number. */
1252 	if (unit >= sd_cd.cd_ndevs || (sd = sd_cd.cd_devs[unit]) == NULL)
1253 		return (ENXIO);
1254 
1255 	if ((sd->sc_dev.dv_flags & DVF_ACTIVE) == 0)
1256 		return (ENODEV);
1257 
1258 	/* Make sure it was initialized. */
1259 	if ((sd->sc_link->flags & SDEV_MEDIA_LOADED) != SDEV_MEDIA_LOADED)
1260 		return (ENXIO);
1261 
1262 	/* Convert to disk sectors.  Request must be a multiple of size. */
1263 	lp = sd->sc_dk.dk_label;
1264 	sectorsize = lp->d_secsize;
1265 	if ((size % sectorsize) != 0)
1266 		return (EFAULT);
1267 	totwrt = size / sectorsize;
1268 	blkno = dbtob(blkno) / sectorsize;	/* blkno in DEV_BSIZE units */
1269 
1270 	nsects = lp->d_partitions[part].p_size;
1271 	sectoff = lp->d_partitions[part].p_offset;
1272 
1273 	/* Check transfer bounds against partition size. */
1274 	if ((blkno < 0) || ((blkno + totwrt) > nsects))
1275 		return (EINVAL);
1276 
1277 	/* Offset block number to start of partition. */
1278 	blkno += sectoff;
1279 
1280 	xs = &sx;
1281 
1282 	while (totwrt > 0) {
1283 		nwrt = totwrt;		/* XXX */
1284 #ifndef	SD_DUMP_NOT_TRUSTED
1285 		/*
1286 		 *  Fill out the scsi command
1287 		 */
1288 		bzero(&cmd, sizeof(cmd));
1289 		cmd.opcode = WRITE_BIG;
1290 		_lto4b(blkno, cmd.addr);
1291 		_lto2b(nwrt, cmd.length);
1292 		/*
1293 		 * Fill out the scsipi_xfer structure
1294 		 *    Note: we cannot sleep as we may be an interrupt
1295 		 * don't use scsipi_command() as it may want to wait
1296 		 * for an xs.
1297 		 */
1298 		bzero(xs, sizeof(sx));
1299 		xs->xs_control |= XS_CTL_NOSLEEP | XS_CTL_POLL |
1300 		    XS_CTL_DATA_OUT;
1301 		xs->xs_status = 0;
1302 		xs->sc_link = sd->sc_link;
1303 		xs->retries = SDRETRIES;
1304 		xs->timeout = 10000;	/* 10000 millisecs for a disk ! */
1305 		xs->cmd = (struct scsipi_generic *)&cmd;
1306 		xs->cmdlen = sizeof(cmd);
1307 		xs->resid = nwrt * sectorsize;
1308 		xs->error = XS_NOERROR;
1309 		xs->bp = 0;
1310 		xs->data = va;
1311 		xs->datalen = nwrt * sectorsize;
1312 
1313 		/*
1314 		 * Pass all this info to the scsi driver.
1315 		 */
1316 		retval = scsipi_command_direct(xs);
1317 		if (retval != COMPLETE)
1318 			return (ENXIO);
1319 #else	/* SD_DUMP_NOT_TRUSTED */
1320 		/* Let's just talk about this first... */
1321 		printf("sd%d: dump addr 0x%x, blk %d\n", unit, va, blkno);
1322 		delay(500 * 1000);	/* half a second */
1323 #endif	/* SD_DUMP_NOT_TRUSTED */
1324 
1325 		/* update block count */
1326 		totwrt -= nwrt;
1327 		blkno += nwrt;
1328 		va += sectorsize * nwrt;
1329 	}
1330 	sddoingadump = 0;
1331 	return (0);
1332 }
1333