xref: /openbmc/linux/drivers/scsi/sr.c (revision 206a81c1)
1 /*
2  *  sr.c Copyright (C) 1992 David Giller
3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4  *
5  *  adapted from:
6  *      sd.c Copyright (C) 1992 Drew Eckhardt
7  *      Linux scsi disk driver by
8  *              Drew Eckhardt <drew@colorado.edu>
9  *
10  *	Modified by Eric Youngdale ericy@andante.org to
11  *	add scatter-gather, multiple outstanding request, and other
12  *	enhancements.
13  *
14  *      Modified by Eric Youngdale eric@andante.org to support loadable
15  *      low-level scsi drivers.
16  *
17  *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
18  *      provide auto-eject.
19  *
20  *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
21  *      generic cdrom interface
22  *
23  *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
24  *      interface, capabilities probe additions, ioctl cleanups, etc.
25  *
26  *	Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
27  *
28  *	Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
29  *	transparently and lose the GHOST hack
30  *
31  *	Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
32  *	check resource allocation in sr_init and some cleanups
33  */
34 
35 #include <linux/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/string.h>
41 #include <linux/errno.h>
42 #include <linux/cdrom.h>
43 #include <linux/interrupt.h>
44 #include <linux/init.h>
45 #include <linux/blkdev.h>
46 #include <linux/mutex.h>
47 #include <linux/slab.h>
48 #include <linux/pm_runtime.h>
49 #include <asm/uaccess.h>
50 
51 #include <scsi/scsi.h>
52 #include <scsi/scsi_dbg.h>
53 #include <scsi/scsi_device.h>
54 #include <scsi/scsi_driver.h>
55 #include <scsi/scsi_cmnd.h>
56 #include <scsi/scsi_eh.h>
57 #include <scsi/scsi_host.h>
58 #include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
59 
60 #include "scsi_logging.h"
61 #include "sr.h"
62 
63 
64 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
65 MODULE_LICENSE("GPL");
66 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
67 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
68 MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
69 
70 #define SR_DISKS	256
71 
72 #define SR_CAPABILITIES \
73 	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
74 	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
75 	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
76 	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
77 	 CDC_MRW|CDC_MRW_W|CDC_RAM)
78 
79 static DEFINE_MUTEX(sr_mutex);
80 static int sr_probe(struct device *);
81 static int sr_remove(struct device *);
82 static int sr_init_command(struct scsi_cmnd *SCpnt);
83 static int sr_done(struct scsi_cmnd *);
84 static int sr_runtime_suspend(struct device *dev);
85 
86 static struct dev_pm_ops sr_pm_ops = {
87 	.runtime_suspend	= sr_runtime_suspend,
88 };
89 
90 static struct scsi_driver sr_template = {
91 	.owner			= THIS_MODULE,
92 	.gendrv = {
93 		.name   	= "sr",
94 		.probe		= sr_probe,
95 		.remove		= sr_remove,
96 		.pm		= &sr_pm_ops,
97 	},
98 	.init_command		= sr_init_command,
99 	.done			= sr_done,
100 };
101 
102 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
103 static DEFINE_SPINLOCK(sr_index_lock);
104 
105 /* This semaphore is used to mediate the 0->1 reference get in the
106  * face of object destruction (i.e. we can't allow a get on an
107  * object after last put) */
108 static DEFINE_MUTEX(sr_ref_mutex);
109 
110 static int sr_open(struct cdrom_device_info *, int);
111 static void sr_release(struct cdrom_device_info *);
112 
113 static void get_sectorsize(struct scsi_cd *);
114 static void get_capabilities(struct scsi_cd *);
115 
116 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
117 				    unsigned int clearing, int slot);
118 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
119 
120 static struct cdrom_device_ops sr_dops = {
121 	.open			= sr_open,
122 	.release	 	= sr_release,
123 	.drive_status	 	= sr_drive_status,
124 	.check_events		= sr_check_events,
125 	.tray_move		= sr_tray_move,
126 	.lock_door		= sr_lock_door,
127 	.select_speed		= sr_select_speed,
128 	.get_last_session	= sr_get_last_session,
129 	.get_mcn		= sr_get_mcn,
130 	.reset			= sr_reset,
131 	.audio_ioctl		= sr_audio_ioctl,
132 	.capability		= SR_CAPABILITIES,
133 	.generic_packet		= sr_packet,
134 };
135 
136 static void sr_kref_release(struct kref *kref);
137 
138 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
139 {
140 	return container_of(disk->private_data, struct scsi_cd, driver);
141 }
142 
143 static int sr_runtime_suspend(struct device *dev)
144 {
145 	struct scsi_cd *cd = dev_get_drvdata(dev);
146 
147 	if (cd->media_present)
148 		return -EBUSY;
149 	else
150 		return 0;
151 }
152 
153 /*
154  * The get and put routines for the struct scsi_cd.  Note this entity
155  * has a scsi_device pointer and owns a reference to this.
156  */
157 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
158 {
159 	struct scsi_cd *cd = NULL;
160 
161 	mutex_lock(&sr_ref_mutex);
162 	if (disk->private_data == NULL)
163 		goto out;
164 	cd = scsi_cd(disk);
165 	kref_get(&cd->kref);
166 	if (scsi_device_get(cd->device)) {
167 		kref_put(&cd->kref, sr_kref_release);
168 		cd = NULL;
169 	}
170  out:
171 	mutex_unlock(&sr_ref_mutex);
172 	return cd;
173 }
174 
175 static void scsi_cd_put(struct scsi_cd *cd)
176 {
177 	struct scsi_device *sdev = cd->device;
178 
179 	mutex_lock(&sr_ref_mutex);
180 	kref_put(&cd->kref, sr_kref_release);
181 	scsi_device_put(sdev);
182 	mutex_unlock(&sr_ref_mutex);
183 }
184 
185 static unsigned int sr_get_events(struct scsi_device *sdev)
186 {
187 	u8 buf[8];
188 	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
189 		     1,			/* polled */
190 		     0, 0,		/* reserved */
191 		     1 << 4,		/* notification class: media */
192 		     0, 0,		/* reserved */
193 		     0, sizeof(buf),	/* allocation length */
194 		     0,			/* control */
195 	};
196 	struct event_header *eh = (void *)buf;
197 	struct media_event_desc *med = (void *)(buf + 4);
198 	struct scsi_sense_hdr sshdr;
199 	int result;
200 
201 	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
202 				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
203 	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
204 		return DISK_EVENT_MEDIA_CHANGE;
205 
206 	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
207 		return 0;
208 
209 	if (eh->nea || eh->notification_class != 0x4)
210 		return 0;
211 
212 	if (med->media_event_code == 1)
213 		return DISK_EVENT_EJECT_REQUEST;
214 	else if (med->media_event_code == 2)
215 		return DISK_EVENT_MEDIA_CHANGE;
216 	return 0;
217 }
218 
219 /*
220  * This function checks to see if the media has been changed or eject
221  * button has been pressed.  It is possible that we have already
222  * sensed a change, or the drive may have sensed one and not yet
223  * reported it.  The past events are accumulated in sdev->changed and
224  * returned together with the current state.
225  */
226 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
227 				    unsigned int clearing, int slot)
228 {
229 	struct scsi_cd *cd = cdi->handle;
230 	bool last_present;
231 	struct scsi_sense_hdr sshdr;
232 	unsigned int events;
233 	int ret;
234 
235 	/* no changer support */
236 	if (CDSL_CURRENT != slot)
237 		return 0;
238 
239 	events = sr_get_events(cd->device);
240 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
241 
242 	/*
243 	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
244 	 * for several times in a row.  We rely on TUR only for this likely
245 	 * broken device, to prevent generating incorrect media changed
246 	 * events for every open().
247 	 */
248 	if (cd->ignore_get_event) {
249 		events &= ~DISK_EVENT_MEDIA_CHANGE;
250 		goto do_tur;
251 	}
252 
253 	/*
254 	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
255 	 * is being cleared.  Note that there are devices which hang
256 	 * if asked to execute TUR repeatedly.
257 	 */
258 	if (cd->device->changed) {
259 		events |= DISK_EVENT_MEDIA_CHANGE;
260 		cd->device->changed = 0;
261 		cd->tur_changed = true;
262 	}
263 
264 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
265 		return events;
266 do_tur:
267 	/* let's see whether the media is there with TUR */
268 	last_present = cd->media_present;
269 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
270 
271 	/*
272 	 * Media is considered to be present if TUR succeeds or fails with
273 	 * sense data indicating something other than media-not-present
274 	 * (ASC 0x3a).
275 	 */
276 	cd->media_present = scsi_status_is_good(ret) ||
277 		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
278 
279 	if (last_present != cd->media_present)
280 		cd->device->changed = 1;
281 
282 	if (cd->device->changed) {
283 		events |= DISK_EVENT_MEDIA_CHANGE;
284 		cd->device->changed = 0;
285 		cd->tur_changed = true;
286 	}
287 
288 	if (cd->ignore_get_event)
289 		return events;
290 
291 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
292 	if (!cd->tur_changed) {
293 		if (cd->get_event_changed) {
294 			if (cd->tur_mismatch++ > 8) {
295 				sdev_printk(KERN_WARNING, cd->device,
296 					    "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
297 				cd->ignore_get_event = true;
298 			}
299 		} else {
300 			cd->tur_mismatch = 0;
301 		}
302 	}
303 	cd->tur_changed = false;
304 	cd->get_event_changed = false;
305 
306 	return events;
307 }
308 
309 /*
310  * sr_done is the interrupt routine for the device driver.
311  *
312  * It will be notified on the end of a SCSI read / write, and will take one
313  * of several actions based on success or failure.
314  */
315 static int sr_done(struct scsi_cmnd *SCpnt)
316 {
317 	int result = SCpnt->result;
318 	int this_count = scsi_bufflen(SCpnt);
319 	int good_bytes = (result == 0 ? this_count : 0);
320 	int block_sectors = 0;
321 	long error_sector;
322 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
323 
324 #ifdef DEBUG
325 	printk("sr.c done: %x\n", result);
326 #endif
327 
328 	/*
329 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
330 	 * success.  Since this is a relatively rare error condition, no
331 	 * care is taken to avoid unnecessary additional work such as
332 	 * memcpy's that could be avoided.
333 	 */
334 	if (driver_byte(result) != 0 &&		/* An error occurred */
335 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
336 		switch (SCpnt->sense_buffer[2]) {
337 		case MEDIUM_ERROR:
338 		case VOLUME_OVERFLOW:
339 		case ILLEGAL_REQUEST:
340 			if (!(SCpnt->sense_buffer[0] & 0x90))
341 				break;
342 			error_sector = (SCpnt->sense_buffer[3] << 24) |
343 				(SCpnt->sense_buffer[4] << 16) |
344 				(SCpnt->sense_buffer[5] << 8) |
345 				SCpnt->sense_buffer[6];
346 			if (SCpnt->request->bio != NULL)
347 				block_sectors =
348 					bio_sectors(SCpnt->request->bio);
349 			if (block_sectors < 4)
350 				block_sectors = 4;
351 			if (cd->device->sector_size == 2048)
352 				error_sector <<= 2;
353 			error_sector &= ~(block_sectors - 1);
354 			good_bytes = (error_sector -
355 				      blk_rq_pos(SCpnt->request)) << 9;
356 			if (good_bytes < 0 || good_bytes >= this_count)
357 				good_bytes = 0;
358 			/*
359 			 * The SCSI specification allows for the value
360 			 * returned by READ CAPACITY to be up to 75 2K
361 			 * sectors past the last readable block.
362 			 * Therefore, if we hit a medium error within the
363 			 * last 75 2K sectors, we decrease the saved size
364 			 * value.
365 			 */
366 			if (error_sector < get_capacity(cd->disk) &&
367 			    cd->capacity - error_sector < 4 * 75)
368 				set_capacity(cd->disk, error_sector);
369 			break;
370 
371 		case RECOVERED_ERROR:
372 			good_bytes = this_count;
373 			break;
374 
375 		default:
376 			break;
377 		}
378 	}
379 
380 	return good_bytes;
381 }
382 
383 static int sr_init_command(struct scsi_cmnd *SCpnt)
384 {
385 	int block = 0, this_count, s_size;
386 	struct scsi_cd *cd;
387 	struct request *rq = SCpnt->request;
388 	struct scsi_device *sdp = SCpnt->device;
389 	int ret;
390 
391 	ret = scsi_setup_fs_cmnd(sdp, rq);
392 	if (ret != BLKPREP_OK)
393 		goto out;
394 	SCpnt = rq->special;
395 	cd = scsi_cd(rq->rq_disk);
396 
397 	/* from here on until we're complete, any goto out
398 	 * is used for a killable error condition */
399 	ret = BLKPREP_KILL;
400 
401 	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
402 				cd->disk->disk_name, block));
403 
404 	if (!cd->device || !scsi_device_online(cd->device)) {
405 		SCSI_LOG_HLQUEUE(2, printk("Finishing %u sectors\n",
406 					   blk_rq_sectors(rq)));
407 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
408 		goto out;
409 	}
410 
411 	if (cd->device->changed) {
412 		/*
413 		 * quietly refuse to do anything to a changed disc until the
414 		 * changed bit has been reset
415 		 */
416 		goto out;
417 	}
418 
419 	/*
420 	 * we do lazy blocksize switching (when reading XA sectors,
421 	 * see CDROMREADMODE2 ioctl)
422 	 */
423 	s_size = cd->device->sector_size;
424 	if (s_size > 2048) {
425 		if (!in_interrupt())
426 			sr_set_blocklength(cd, 2048);
427 		else
428 			printk("sr: can't switch blocksize: in interrupt\n");
429 	}
430 
431 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
432 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
433 		goto out;
434 	}
435 
436 	if (rq_data_dir(rq) == WRITE) {
437 		if (!cd->device->writeable)
438 			goto out;
439 		SCpnt->cmnd[0] = WRITE_10;
440 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
441  	 	cd->cdi.media_written = 1;
442 	} else if (rq_data_dir(rq) == READ) {
443 		SCpnt->cmnd[0] = READ_10;
444 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
445 	} else {
446 		blk_dump_rq_flags(rq, "Unknown sr command");
447 		goto out;
448 	}
449 
450 	{
451 		struct scatterlist *sg;
452 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
453 
454 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
455 			size += sg->length;
456 
457 		if (size != scsi_bufflen(SCpnt)) {
458 			scmd_printk(KERN_ERR, SCpnt,
459 				"mismatch count %d, bytes %d\n",
460 				size, scsi_bufflen(SCpnt));
461 			if (scsi_bufflen(SCpnt) > size)
462 				SCpnt->sdb.length = size;
463 		}
464 	}
465 
466 	/*
467 	 * request doesn't start on hw block boundary, add scatter pads
468 	 */
469 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
470 	    (scsi_bufflen(SCpnt) % s_size)) {
471 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
472 		goto out;
473 	}
474 
475 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
476 
477 
478 	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%u 512 byte blocks.\n",
479 				cd->cdi.name,
480 				(rq_data_dir(rq) == WRITE) ?
481 					"writing" : "reading",
482 				this_count, blk_rq_sectors(rq)));
483 
484 	SCpnt->cmnd[1] = 0;
485 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
486 
487 	if (this_count > 0xffff) {
488 		this_count = 0xffff;
489 		SCpnt->sdb.length = this_count * s_size;
490 	}
491 
492 	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
493 	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
494 	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
495 	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
496 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
497 	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
498 	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
499 
500 	/*
501 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
502 	 * host adapter, it's safe to assume that we can at least transfer
503 	 * this many bytes between each connect / disconnect.
504 	 */
505 	SCpnt->transfersize = cd->device->sector_size;
506 	SCpnt->underflow = this_count << 9;
507 	SCpnt->allowed = MAX_RETRIES;
508 
509 	/*
510 	 * This indicates that the command is ready from our end to be
511 	 * queued.
512 	 */
513 	ret = BLKPREP_OK;
514  out:
515 	return ret;
516 }
517 
518 static int sr_block_open(struct block_device *bdev, fmode_t mode)
519 {
520 	struct scsi_cd *cd;
521 	int ret = -ENXIO;
522 
523 	mutex_lock(&sr_mutex);
524 	cd = scsi_cd_get(bdev->bd_disk);
525 	if (cd) {
526 		ret = cdrom_open(&cd->cdi, bdev, mode);
527 		if (ret)
528 			scsi_cd_put(cd);
529 	}
530 	mutex_unlock(&sr_mutex);
531 	return ret;
532 }
533 
534 static void sr_block_release(struct gendisk *disk, fmode_t mode)
535 {
536 	struct scsi_cd *cd = scsi_cd(disk);
537 	mutex_lock(&sr_mutex);
538 	cdrom_release(&cd->cdi, mode);
539 	scsi_cd_put(cd);
540 	mutex_unlock(&sr_mutex);
541 }
542 
543 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
544 			  unsigned long arg)
545 {
546 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
547 	struct scsi_device *sdev = cd->device;
548 	void __user *argp = (void __user *)arg;
549 	int ret;
550 
551 	mutex_lock(&sr_mutex);
552 
553 	/*
554 	 * Send SCSI addressing ioctls directly to mid level, send other
555 	 * ioctls to cdrom/block level.
556 	 */
557 	switch (cmd) {
558 	case SCSI_IOCTL_GET_IDLUN:
559 	case SCSI_IOCTL_GET_BUS_NUMBER:
560 		ret = scsi_ioctl(sdev, cmd, argp);
561 		goto out;
562 	}
563 
564 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
565 	if (ret != -ENOSYS)
566 		goto out;
567 
568 	/*
569 	 * ENODEV means that we didn't recognise the ioctl, or that we
570 	 * cannot execute it in the current device state.  In either
571 	 * case fall through to scsi_ioctl, which will return ENDOEV again
572 	 * if it doesn't recognise the ioctl
573 	 */
574 	ret = scsi_nonblockable_ioctl(sdev, cmd, argp,
575 					(mode & FMODE_NDELAY) != 0);
576 	if (ret != -ENODEV)
577 		goto out;
578 	ret = scsi_ioctl(sdev, cmd, argp);
579 
580 out:
581 	mutex_unlock(&sr_mutex);
582 	return ret;
583 }
584 
585 static unsigned int sr_block_check_events(struct gendisk *disk,
586 					  unsigned int clearing)
587 {
588 	struct scsi_cd *cd = scsi_cd(disk);
589 
590 	if (atomic_read(&cd->device->disk_events_disable_depth))
591 		return 0;
592 
593 	return cdrom_check_events(&cd->cdi, clearing);
594 }
595 
596 static int sr_block_revalidate_disk(struct gendisk *disk)
597 {
598 	struct scsi_cd *cd = scsi_cd(disk);
599 	struct scsi_sense_hdr sshdr;
600 
601 	/* if the unit is not ready, nothing more to do */
602 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
603 		goto out;
604 
605 	sr_cd_check(&cd->cdi);
606 	get_sectorsize(cd);
607 out:
608 	return 0;
609 }
610 
611 static const struct block_device_operations sr_bdops =
612 {
613 	.owner		= THIS_MODULE,
614 	.open		= sr_block_open,
615 	.release	= sr_block_release,
616 	.ioctl		= sr_block_ioctl,
617 	.check_events	= sr_block_check_events,
618 	.revalidate_disk = sr_block_revalidate_disk,
619 	/*
620 	 * No compat_ioctl for now because sr_block_ioctl never
621 	 * seems to pass arbitrary ioctls down to host drivers.
622 	 */
623 };
624 
625 static int sr_open(struct cdrom_device_info *cdi, int purpose)
626 {
627 	struct scsi_cd *cd = cdi->handle;
628 	struct scsi_device *sdev = cd->device;
629 	int retval;
630 
631 	/*
632 	 * If the device is in error recovery, wait until it is done.
633 	 * If the device is offline, then disallow any access to it.
634 	 */
635 	retval = -ENXIO;
636 	if (!scsi_block_when_processing_errors(sdev))
637 		goto error_out;
638 
639 	return 0;
640 
641 error_out:
642 	return retval;
643 }
644 
645 static void sr_release(struct cdrom_device_info *cdi)
646 {
647 	struct scsi_cd *cd = cdi->handle;
648 
649 	if (cd->device->sector_size > 2048)
650 		sr_set_blocklength(cd, 2048);
651 
652 }
653 
654 static int sr_probe(struct device *dev)
655 {
656 	struct scsi_device *sdev = to_scsi_device(dev);
657 	struct gendisk *disk;
658 	struct scsi_cd *cd;
659 	int minor, error;
660 
661 	error = -ENODEV;
662 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
663 		goto fail;
664 
665 	error = -ENOMEM;
666 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
667 	if (!cd)
668 		goto fail;
669 
670 	kref_init(&cd->kref);
671 
672 	disk = alloc_disk(1);
673 	if (!disk)
674 		goto fail_free;
675 
676 	spin_lock(&sr_index_lock);
677 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
678 	if (minor == SR_DISKS) {
679 		spin_unlock(&sr_index_lock);
680 		error = -EBUSY;
681 		goto fail_put;
682 	}
683 	__set_bit(minor, sr_index_bits);
684 	spin_unlock(&sr_index_lock);
685 
686 	disk->major = SCSI_CDROM_MAJOR;
687 	disk->first_minor = minor;
688 	sprintf(disk->disk_name, "sr%d", minor);
689 	disk->fops = &sr_bdops;
690 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
691 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
692 
693 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
694 
695 	cd->device = sdev;
696 	cd->disk = disk;
697 	cd->driver = &sr_template;
698 	cd->disk = disk;
699 	cd->capacity = 0x1fffff;
700 	cd->device->changed = 1;	/* force recheck CD type */
701 	cd->media_present = 1;
702 	cd->use = 1;
703 	cd->readcd_known = 0;
704 	cd->readcd_cdda = 0;
705 
706 	cd->cdi.ops = &sr_dops;
707 	cd->cdi.handle = cd;
708 	cd->cdi.mask = 0;
709 	cd->cdi.capacity = 1;
710 	sprintf(cd->cdi.name, "sr%d", minor);
711 
712 	sdev->sector_size = 2048;	/* A guess, just in case */
713 
714 	/* FIXME: need to handle a get_capabilities failure properly ?? */
715 	get_capabilities(cd);
716 	sr_vendor_init(cd);
717 
718 	disk->driverfs_dev = &sdev->sdev_gendev;
719 	set_capacity(disk, cd->capacity);
720 	disk->private_data = &cd->driver;
721 	disk->queue = sdev->request_queue;
722 	cd->cdi.disk = disk;
723 
724 	if (register_cdrom(&cd->cdi))
725 		goto fail_put;
726 
727 	/*
728 	 * Initialize block layer runtime PM stuffs before the
729 	 * periodic event checking request gets started in add_disk.
730 	 */
731 	blk_pm_runtime_init(sdev->request_queue, dev);
732 
733 	dev_set_drvdata(dev, cd);
734 	disk->flags |= GENHD_FL_REMOVABLE;
735 	add_disk(disk);
736 
737 	sdev_printk(KERN_DEBUG, sdev,
738 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
739 	scsi_autopm_put_device(cd->device);
740 
741 	return 0;
742 
743 fail_put:
744 	put_disk(disk);
745 fail_free:
746 	kfree(cd);
747 fail:
748 	return error;
749 }
750 
751 
752 static void get_sectorsize(struct scsi_cd *cd)
753 {
754 	unsigned char cmd[10];
755 	unsigned char buffer[8];
756 	int the_result, retries = 3;
757 	int sector_size;
758 	struct request_queue *queue;
759 
760 	do {
761 		cmd[0] = READ_CAPACITY;
762 		memset((void *) &cmd[1], 0, 9);
763 		memset(buffer, 0, sizeof(buffer));
764 
765 		/* Do the command and wait.. */
766 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
767 					      buffer, sizeof(buffer), NULL,
768 					      SR_TIMEOUT, MAX_RETRIES, NULL);
769 
770 		retries--;
771 
772 	} while (the_result && retries);
773 
774 
775 	if (the_result) {
776 		cd->capacity = 0x1fffff;
777 		sector_size = 2048;	/* A guess, just in case */
778 	} else {
779 		long last_written;
780 
781 		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
782 				    (buffer[2] << 8) | buffer[3]);
783 		/*
784 		 * READ_CAPACITY doesn't return the correct size on
785 		 * certain UDF media.  If last_written is larger, use
786 		 * it instead.
787 		 *
788 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
789 		 */
790 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
791 			cd->capacity = max_t(long, cd->capacity, last_written);
792 
793 		sector_size = (buffer[4] << 24) |
794 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
795 		switch (sector_size) {
796 			/*
797 			 * HP 4020i CD-Recorder reports 2340 byte sectors
798 			 * Philips CD-Writers report 2352 byte sectors
799 			 *
800 			 * Use 2k sectors for them..
801 			 */
802 		case 0:
803 		case 2340:
804 		case 2352:
805 			sector_size = 2048;
806 			/* fall through */
807 		case 2048:
808 			cd->capacity *= 4;
809 			/* fall through */
810 		case 512:
811 			break;
812 		default:
813 			printk("%s: unsupported sector size %d.\n",
814 			       cd->cdi.name, sector_size);
815 			cd->capacity = 0;
816 		}
817 
818 		cd->device->sector_size = sector_size;
819 
820 		/*
821 		 * Add this so that we have the ability to correctly gauge
822 		 * what the device is capable of.
823 		 */
824 		set_capacity(cd->disk, cd->capacity);
825 	}
826 
827 	queue = cd->device->request_queue;
828 	blk_queue_logical_block_size(queue, sector_size);
829 
830 	return;
831 }
832 
833 static void get_capabilities(struct scsi_cd *cd)
834 {
835 	unsigned char *buffer;
836 	struct scsi_mode_data data;
837 	struct scsi_sense_hdr sshdr;
838 	int rc, n;
839 
840 	static const char *loadmech[] =
841 	{
842 		"caddy",
843 		"tray",
844 		"pop-up",
845 		"",
846 		"changer",
847 		"cartridge changer",
848 		"",
849 		""
850 	};
851 
852 
853 	/* allocate transfer buffer */
854 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
855 	if (!buffer) {
856 		printk(KERN_ERR "sr: out of memory.\n");
857 		return;
858 	}
859 
860 	/* eat unit attentions */
861 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
862 
863 	/* ask for mode page 0x2a */
864 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
865 			     SR_TIMEOUT, 3, &data, NULL);
866 
867 	if (!scsi_status_is_good(rc)) {
868 		/* failed, drive doesn't have capabilities mode page */
869 		cd->cdi.speed = 1;
870 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
871 				 CDC_DVD | CDC_DVD_RAM |
872 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
873 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
874 		kfree(buffer);
875 		printk("%s: scsi-1 drive\n", cd->cdi.name);
876 		return;
877 	}
878 
879 	n = data.header_length + data.block_descriptor_length;
880 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
881 	cd->readcd_known = 1;
882 	cd->readcd_cdda = buffer[n + 5] & 0x01;
883 	/* print some capability bits */
884 	printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
885 	       ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
886 	       cd->cdi.speed,
887 	       buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
888 	       buffer[n + 3] & 0x20 ? "dvd-ram " : "",
889 	       buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
890 	       buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
891 	       buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
892 	       loadmech[buffer[n + 6] >> 5]);
893 	if ((buffer[n + 6] >> 5) == 0)
894 		/* caddy drives can't close tray... */
895 		cd->cdi.mask |= CDC_CLOSE_TRAY;
896 	if ((buffer[n + 2] & 0x8) == 0)
897 		/* not a DVD drive */
898 		cd->cdi.mask |= CDC_DVD;
899 	if ((buffer[n + 3] & 0x20) == 0)
900 		/* can't write DVD-RAM media */
901 		cd->cdi.mask |= CDC_DVD_RAM;
902 	if ((buffer[n + 3] & 0x10) == 0)
903 		/* can't write DVD-R media */
904 		cd->cdi.mask |= CDC_DVD_R;
905 	if ((buffer[n + 3] & 0x2) == 0)
906 		/* can't write CD-RW media */
907 		cd->cdi.mask |= CDC_CD_RW;
908 	if ((buffer[n + 3] & 0x1) == 0)
909 		/* can't write CD-R media */
910 		cd->cdi.mask |= CDC_CD_R;
911 	if ((buffer[n + 6] & 0x8) == 0)
912 		/* can't eject */
913 		cd->cdi.mask |= CDC_OPEN_TRAY;
914 
915 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
916 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
917 		cd->cdi.capacity =
918 		    cdrom_number_of_slots(&cd->cdi);
919 	if (cd->cdi.capacity <= 1)
920 		/* not a changer */
921 		cd->cdi.mask |= CDC_SELECT_DISC;
922 	/*else    I don't think it can close its tray
923 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
924 
925 	/*
926 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
927 	 */
928 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
929 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
930 		cd->device->writeable = 1;
931 	}
932 
933 	kfree(buffer);
934 }
935 
936 /*
937  * sr_packet() is the entry point for the generic commands generated
938  * by the Uniform CD-ROM layer.
939  */
940 static int sr_packet(struct cdrom_device_info *cdi,
941 		struct packet_command *cgc)
942 {
943 	struct scsi_cd *cd = cdi->handle;
944 	struct scsi_device *sdev = cd->device;
945 
946 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
947 		return -EDRIVE_CANT_DO_THIS;
948 
949 	if (cgc->timeout <= 0)
950 		cgc->timeout = IOCTL_TIMEOUT;
951 
952 	sr_do_ioctl(cd, cgc);
953 
954 	return cgc->stat;
955 }
956 
957 /**
958  *	sr_kref_release - Called to free the scsi_cd structure
959  *	@kref: pointer to embedded kref
960  *
961  *	sr_ref_mutex must be held entering this routine.  Because it is
962  *	called on last put, you should always use the scsi_cd_get()
963  *	scsi_cd_put() helpers which manipulate the semaphore directly
964  *	and never do a direct kref_put().
965  **/
966 static void sr_kref_release(struct kref *kref)
967 {
968 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
969 	struct gendisk *disk = cd->disk;
970 
971 	spin_lock(&sr_index_lock);
972 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
973 	spin_unlock(&sr_index_lock);
974 
975 	unregister_cdrom(&cd->cdi);
976 
977 	disk->private_data = NULL;
978 
979 	put_disk(disk);
980 
981 	kfree(cd);
982 }
983 
984 static int sr_remove(struct device *dev)
985 {
986 	struct scsi_cd *cd = dev_get_drvdata(dev);
987 
988 	scsi_autopm_get_device(cd->device);
989 
990 	del_gendisk(cd->disk);
991 
992 	mutex_lock(&sr_ref_mutex);
993 	kref_put(&cd->kref, sr_kref_release);
994 	mutex_unlock(&sr_ref_mutex);
995 
996 	return 0;
997 }
998 
999 static int __init init_sr(void)
1000 {
1001 	int rc;
1002 
1003 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1004 	if (rc)
1005 		return rc;
1006 	rc = scsi_register_driver(&sr_template.gendrv);
1007 	if (rc)
1008 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1009 
1010 	return rc;
1011 }
1012 
1013 static void __exit exit_sr(void)
1014 {
1015 	scsi_unregister_driver(&sr_template.gendrv);
1016 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1017 }
1018 
1019 module_init(init_sr);
1020 module_exit(exit_sr);
1021 MODULE_LICENSE("GPL");
1022