xref: /openbmc/linux/drivers/scsi/sr.c (revision 69868c3b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  sr.c Copyright (C) 1992 David Giller
4  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
5  *
6  *  adapted from:
7  *      sd.c Copyright (C) 1992 Drew Eckhardt
8  *      Linux scsi disk driver by
9  *              Drew Eckhardt <drew@colorado.edu>
10  *
11  *	Modified by Eric Youngdale ericy@andante.org to
12  *	add scatter-gather, multiple outstanding request, and other
13  *	enhancements.
14  *
15  *      Modified by Eric Youngdale eric@andante.org to support loadable
16  *      low-level scsi drivers.
17  *
18  *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
19  *      provide auto-eject.
20  *
21  *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
22  *      generic cdrom interface
23  *
24  *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
25  *      interface, capabilities probe additions, ioctl cleanups, etc.
26  *
27  *	Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
28  *
29  *	Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
30  *	transparently and lose the GHOST hack
31  *
32  *	Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
33  *	check resource allocation in sr_init and some cleanups
34  */
35 
36 #include <linux/module.h>
37 #include <linux/fs.h>
38 #include <linux/kernel.h>
39 #include <linux/mm.h>
40 #include <linux/bio.h>
41 #include <linux/compat.h>
42 #include <linux/string.h>
43 #include <linux/errno.h>
44 #include <linux/cdrom.h>
45 #include <linux/interrupt.h>
46 #include <linux/init.h>
47 #include <linux/blkdev.h>
48 #include <linux/blk-pm.h>
49 #include <linux/mutex.h>
50 #include <linux/slab.h>
51 #include <linux/pm_runtime.h>
52 #include <linux/uaccess.h>
53 
54 #include <asm/unaligned.h>
55 
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_dbg.h>
58 #include <scsi/scsi_device.h>
59 #include <scsi/scsi_driver.h>
60 #include <scsi/scsi_cmnd.h>
61 #include <scsi/scsi_eh.h>
62 #include <scsi/scsi_host.h>
63 #include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
64 
65 #include "scsi_logging.h"
66 #include "sr.h"
67 
68 
69 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
70 MODULE_LICENSE("GPL");
71 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
72 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
73 MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
74 
75 #define SR_DISKS	256
76 
77 #define SR_CAPABILITIES \
78 	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
79 	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
80 	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
81 	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
82 	 CDC_MRW|CDC_MRW_W|CDC_RAM)
83 
84 static int sr_probe(struct device *);
85 static int sr_remove(struct device *);
86 static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
87 static int sr_done(struct scsi_cmnd *);
88 static int sr_runtime_suspend(struct device *dev);
89 
90 static const struct dev_pm_ops sr_pm_ops = {
91 	.runtime_suspend	= sr_runtime_suspend,
92 };
93 
94 static struct scsi_driver sr_template = {
95 	.gendrv = {
96 		.name   	= "sr",
97 		.owner		= THIS_MODULE,
98 		.probe		= sr_probe,
99 		.remove		= sr_remove,
100 		.pm		= &sr_pm_ops,
101 	},
102 	.init_command		= sr_init_command,
103 	.done			= sr_done,
104 };
105 
106 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
107 static DEFINE_SPINLOCK(sr_index_lock);
108 
109 /* This semaphore is used to mediate the 0->1 reference get in the
110  * face of object destruction (i.e. we can't allow a get on an
111  * object after last put) */
112 static DEFINE_MUTEX(sr_ref_mutex);
113 
114 static int sr_open(struct cdrom_device_info *, int);
115 static void sr_release(struct cdrom_device_info *);
116 
117 static void get_sectorsize(struct scsi_cd *);
118 static void get_capabilities(struct scsi_cd *);
119 
120 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
121 				    unsigned int clearing, int slot);
122 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
123 static int sr_read_cdda_bpc(struct cdrom_device_info *cdi, void __user *ubuf,
124 		u32 lba, u32 nr, u8 *last_sense);
125 
126 static const struct cdrom_device_ops sr_dops = {
127 	.open			= sr_open,
128 	.release	 	= sr_release,
129 	.drive_status	 	= sr_drive_status,
130 	.check_events		= sr_check_events,
131 	.tray_move		= sr_tray_move,
132 	.lock_door		= sr_lock_door,
133 	.select_speed		= sr_select_speed,
134 	.get_last_session	= sr_get_last_session,
135 	.get_mcn		= sr_get_mcn,
136 	.reset			= sr_reset,
137 	.audio_ioctl		= sr_audio_ioctl,
138 	.generic_packet		= sr_packet,
139 	.read_cdda_bpc		= sr_read_cdda_bpc,
140 	.capability		= SR_CAPABILITIES,
141 };
142 
143 static void sr_kref_release(struct kref *kref);
144 
145 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
146 {
147 	return container_of(disk->private_data, struct scsi_cd, driver);
148 }
149 
150 static int sr_runtime_suspend(struct device *dev)
151 {
152 	struct scsi_cd *cd = dev_get_drvdata(dev);
153 
154 	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
155 		return 0;
156 
157 	if (cd->media_present)
158 		return -EBUSY;
159 	else
160 		return 0;
161 }
162 
163 /*
164  * The get and put routines for the struct scsi_cd.  Note this entity
165  * has a scsi_device pointer and owns a reference to this.
166  */
167 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
168 {
169 	struct scsi_cd *cd = NULL;
170 
171 	mutex_lock(&sr_ref_mutex);
172 	if (disk->private_data == NULL)
173 		goto out;
174 	cd = scsi_cd(disk);
175 	kref_get(&cd->kref);
176 	if (scsi_device_get(cd->device)) {
177 		kref_put(&cd->kref, sr_kref_release);
178 		cd = NULL;
179 	}
180  out:
181 	mutex_unlock(&sr_ref_mutex);
182 	return cd;
183 }
184 
185 static void scsi_cd_put(struct scsi_cd *cd)
186 {
187 	struct scsi_device *sdev = cd->device;
188 
189 	mutex_lock(&sr_ref_mutex);
190 	kref_put(&cd->kref, sr_kref_release);
191 	scsi_device_put(sdev);
192 	mutex_unlock(&sr_ref_mutex);
193 }
194 
195 static unsigned int sr_get_events(struct scsi_device *sdev)
196 {
197 	u8 buf[8];
198 	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
199 		     1,			/* polled */
200 		     0, 0,		/* reserved */
201 		     1 << 4,		/* notification class: media */
202 		     0, 0,		/* reserved */
203 		     0, sizeof(buf),	/* allocation length */
204 		     0,			/* control */
205 	};
206 	struct event_header *eh = (void *)buf;
207 	struct media_event_desc *med = (void *)(buf + 4);
208 	struct scsi_sense_hdr sshdr;
209 	int result;
210 
211 	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
212 				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
213 	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
214 		return DISK_EVENT_MEDIA_CHANGE;
215 
216 	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
217 		return 0;
218 
219 	if (eh->nea || eh->notification_class != 0x4)
220 		return 0;
221 
222 	if (med->media_event_code == 1)
223 		return DISK_EVENT_EJECT_REQUEST;
224 	else if (med->media_event_code == 2)
225 		return DISK_EVENT_MEDIA_CHANGE;
226 	else if (med->media_event_code == 3)
227 		return DISK_EVENT_EJECT_REQUEST;
228 	return 0;
229 }
230 
231 /*
232  * This function checks to see if the media has been changed or eject
233  * button has been pressed.  It is possible that we have already
234  * sensed a change, or the drive may have sensed one and not yet
235  * reported it.  The past events are accumulated in sdev->changed and
236  * returned together with the current state.
237  */
238 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
239 				    unsigned int clearing, int slot)
240 {
241 	struct scsi_cd *cd = cdi->handle;
242 	bool last_present;
243 	struct scsi_sense_hdr sshdr;
244 	unsigned int events;
245 	int ret;
246 
247 	/* no changer support */
248 	if (CDSL_CURRENT != slot)
249 		return 0;
250 
251 	events = sr_get_events(cd->device);
252 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
253 
254 	/*
255 	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
256 	 * for several times in a row.  We rely on TUR only for this likely
257 	 * broken device, to prevent generating incorrect media changed
258 	 * events for every open().
259 	 */
260 	if (cd->ignore_get_event) {
261 		events &= ~DISK_EVENT_MEDIA_CHANGE;
262 		goto do_tur;
263 	}
264 
265 	/*
266 	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
267 	 * is being cleared.  Note that there are devices which hang
268 	 * if asked to execute TUR repeatedly.
269 	 */
270 	if (cd->device->changed) {
271 		events |= DISK_EVENT_MEDIA_CHANGE;
272 		cd->device->changed = 0;
273 		cd->tur_changed = true;
274 	}
275 
276 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
277 		return events;
278 do_tur:
279 	/* let's see whether the media is there with TUR */
280 	last_present = cd->media_present;
281 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
282 
283 	/*
284 	 * Media is considered to be present if TUR succeeds or fails with
285 	 * sense data indicating something other than media-not-present
286 	 * (ASC 0x3a).
287 	 */
288 	cd->media_present = scsi_status_is_good(ret) ||
289 		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
290 
291 	if (last_present != cd->media_present)
292 		cd->device->changed = 1;
293 
294 	if (cd->device->changed) {
295 		events |= DISK_EVENT_MEDIA_CHANGE;
296 		cd->device->changed = 0;
297 		cd->tur_changed = true;
298 	}
299 
300 	if (cd->ignore_get_event)
301 		return events;
302 
303 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
304 	if (!cd->tur_changed) {
305 		if (cd->get_event_changed) {
306 			if (cd->tur_mismatch++ > 8) {
307 				sr_printk(KERN_WARNING, cd,
308 					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
309 				cd->ignore_get_event = true;
310 			}
311 		} else {
312 			cd->tur_mismatch = 0;
313 		}
314 	}
315 	cd->tur_changed = false;
316 	cd->get_event_changed = false;
317 
318 	return events;
319 }
320 
321 /*
322  * sr_done is the interrupt routine for the device driver.
323  *
324  * It will be notified on the end of a SCSI read / write, and will take one
325  * of several actions based on success or failure.
326  */
327 static int sr_done(struct scsi_cmnd *SCpnt)
328 {
329 	int result = SCpnt->result;
330 	int this_count = scsi_bufflen(SCpnt);
331 	int good_bytes = (result == 0 ? this_count : 0);
332 	int block_sectors = 0;
333 	long error_sector;
334 	struct request *rq = scsi_cmd_to_rq(SCpnt);
335 	struct scsi_cd *cd = scsi_cd(rq->rq_disk);
336 
337 #ifdef DEBUG
338 	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
339 #endif
340 
341 	/*
342 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
343 	 * success.  Since this is a relatively rare error condition, no
344 	 * care is taken to avoid unnecessary additional work such as
345 	 * memcpy's that could be avoided.
346 	 */
347 	if (scsi_status_is_check_condition(result) &&
348 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
349 		switch (SCpnt->sense_buffer[2]) {
350 		case MEDIUM_ERROR:
351 		case VOLUME_OVERFLOW:
352 		case ILLEGAL_REQUEST:
353 			if (!(SCpnt->sense_buffer[0] & 0x90))
354 				break;
355 			error_sector =
356 				get_unaligned_be32(&SCpnt->sense_buffer[3]);
357 			if (rq->bio != NULL)
358 				block_sectors = bio_sectors(rq->bio);
359 			if (block_sectors < 4)
360 				block_sectors = 4;
361 			if (cd->device->sector_size == 2048)
362 				error_sector <<= 2;
363 			error_sector &= ~(block_sectors - 1);
364 			good_bytes = (error_sector - blk_rq_pos(rq)) << 9;
365 			if (good_bytes < 0 || good_bytes >= this_count)
366 				good_bytes = 0;
367 			/*
368 			 * The SCSI specification allows for the value
369 			 * returned by READ CAPACITY to be up to 75 2K
370 			 * sectors past the last readable block.
371 			 * Therefore, if we hit a medium error within the
372 			 * last 75 2K sectors, we decrease the saved size
373 			 * value.
374 			 */
375 			if (error_sector < get_capacity(cd->disk) &&
376 			    cd->capacity - error_sector < 4 * 75)
377 				set_capacity(cd->disk, error_sector);
378 			break;
379 
380 		case RECOVERED_ERROR:
381 			good_bytes = this_count;
382 			break;
383 
384 		default:
385 			break;
386 		}
387 	}
388 
389 	return good_bytes;
390 }
391 
392 static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
393 {
394 	int block = 0, this_count, s_size;
395 	struct scsi_cd *cd;
396 	struct request *rq = scsi_cmd_to_rq(SCpnt);
397 	blk_status_t ret;
398 
399 	ret = scsi_alloc_sgtables(SCpnt);
400 	if (ret != BLK_STS_OK)
401 		return ret;
402 	cd = scsi_cd(rq->rq_disk);
403 
404 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
405 		"Doing sr request, block = %d\n", block));
406 
407 	if (!cd->device || !scsi_device_online(cd->device)) {
408 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
409 			"Finishing %u sectors\n", blk_rq_sectors(rq)));
410 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
411 			"Retry with 0x%p\n", SCpnt));
412 		goto out;
413 	}
414 
415 	if (cd->device->changed) {
416 		/*
417 		 * quietly refuse to do anything to a changed disc until the
418 		 * changed bit has been reset
419 		 */
420 		goto out;
421 	}
422 
423 	s_size = cd->device->sector_size;
424 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
425 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
426 		goto out;
427 	}
428 
429 	switch (req_op(rq)) {
430 	case REQ_OP_WRITE:
431 		if (!cd->writeable)
432 			goto out;
433 		SCpnt->cmnd[0] = WRITE_10;
434 		cd->cdi.media_written = 1;
435 		break;
436 	case REQ_OP_READ:
437 		SCpnt->cmnd[0] = READ_10;
438 		break;
439 	default:
440 		blk_dump_rq_flags(rq, "Unknown sr command");
441 		goto out;
442 	}
443 
444 	{
445 		struct scatterlist *sg;
446 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
447 
448 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
449 			size += sg->length;
450 
451 		if (size != scsi_bufflen(SCpnt)) {
452 			scmd_printk(KERN_ERR, SCpnt,
453 				"mismatch count %d, bytes %d\n",
454 				size, scsi_bufflen(SCpnt));
455 			if (scsi_bufflen(SCpnt) > size)
456 				SCpnt->sdb.length = size;
457 		}
458 	}
459 
460 	/*
461 	 * request doesn't start on hw block boundary, add scatter pads
462 	 */
463 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
464 	    (scsi_bufflen(SCpnt) % s_size)) {
465 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
466 		goto out;
467 	}
468 
469 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
470 
471 
472 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
473 					"%s %d/%u 512 byte blocks.\n",
474 					(rq_data_dir(rq) == WRITE) ?
475 					"writing" : "reading",
476 					this_count, blk_rq_sectors(rq)));
477 
478 	SCpnt->cmnd[1] = 0;
479 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
480 
481 	if (this_count > 0xffff) {
482 		this_count = 0xffff;
483 		SCpnt->sdb.length = this_count * s_size;
484 	}
485 
486 	put_unaligned_be32(block, &SCpnt->cmnd[2]);
487 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
488 	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
489 
490 	/*
491 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
492 	 * host adapter, it's safe to assume that we can at least transfer
493 	 * this many bytes between each connect / disconnect.
494 	 */
495 	SCpnt->transfersize = cd->device->sector_size;
496 	SCpnt->underflow = this_count << 9;
497 	SCpnt->allowed = MAX_RETRIES;
498 	SCpnt->cmd_len = 10;
499 
500 	/*
501 	 * This indicates that the command is ready from our end to be queued.
502 	 */
503 	return BLK_STS_OK;
504  out:
505 	scsi_free_sgtables(SCpnt);
506 	return BLK_STS_IOERR;
507 }
508 
509 static void sr_revalidate_disk(struct scsi_cd *cd)
510 {
511 	struct scsi_sense_hdr sshdr;
512 
513 	/* if the unit is not ready, nothing more to do */
514 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
515 		return;
516 	sr_cd_check(&cd->cdi);
517 	get_sectorsize(cd);
518 }
519 
520 static int sr_block_open(struct block_device *bdev, fmode_t mode)
521 {
522 	struct scsi_cd *cd;
523 	struct scsi_device *sdev;
524 	int ret = -ENXIO;
525 
526 	cd = scsi_cd_get(bdev->bd_disk);
527 	if (!cd)
528 		goto out;
529 
530 	sdev = cd->device;
531 	scsi_autopm_get_device(sdev);
532 	if (bdev_check_media_change(bdev))
533 		sr_revalidate_disk(cd);
534 
535 	mutex_lock(&cd->lock);
536 	ret = cdrom_open(&cd->cdi, bdev, mode);
537 	mutex_unlock(&cd->lock);
538 
539 	scsi_autopm_put_device(sdev);
540 	if (ret)
541 		scsi_cd_put(cd);
542 
543 out:
544 	return ret;
545 }
546 
547 static void sr_block_release(struct gendisk *disk, fmode_t mode)
548 {
549 	struct scsi_cd *cd = scsi_cd(disk);
550 
551 	mutex_lock(&cd->lock);
552 	cdrom_release(&cd->cdi, mode);
553 	mutex_unlock(&cd->lock);
554 
555 	scsi_cd_put(cd);
556 }
557 
558 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
559 			  unsigned long arg)
560 {
561 	struct gendisk *disk = bdev->bd_disk;
562 	struct scsi_cd *cd = scsi_cd(disk);
563 	struct scsi_device *sdev = cd->device;
564 	void __user *argp = (void __user *)arg;
565 	int ret;
566 
567 	if (bdev_is_partition(bdev) && !capable(CAP_SYS_RAWIO))
568 		return -ENOIOCTLCMD;
569 
570 	mutex_lock(&cd->lock);
571 
572 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
573 			(mode & FMODE_NDELAY) != 0);
574 	if (ret)
575 		goto out;
576 
577 	scsi_autopm_get_device(sdev);
578 
579 	if (ret != CDROMCLOSETRAY && ret != CDROMEJECT) {
580 		ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
581 		if (ret != -ENOSYS)
582 			goto put;
583 	}
584 	ret = scsi_ioctl(sdev, disk, mode, cmd, argp);
585 
586 put:
587 	scsi_autopm_put_device(sdev);
588 out:
589 	mutex_unlock(&cd->lock);
590 	return ret;
591 }
592 
593 static unsigned int sr_block_check_events(struct gendisk *disk,
594 					  unsigned int clearing)
595 {
596 	unsigned int ret = 0;
597 	struct scsi_cd *cd;
598 
599 	cd = scsi_cd_get(disk);
600 	if (!cd)
601 		return 0;
602 
603 	if (!atomic_read(&cd->device->disk_events_disable_depth))
604 		ret = cdrom_check_events(&cd->cdi, clearing);
605 
606 	scsi_cd_put(cd);
607 	return ret;
608 }
609 
610 static const struct block_device_operations sr_bdops =
611 {
612 	.owner		= THIS_MODULE,
613 	.open		= sr_block_open,
614 	.release	= sr_block_release,
615 	.ioctl		= sr_block_ioctl,
616 	.compat_ioctl	= blkdev_compat_ptr_ioctl,
617 	.check_events	= sr_block_check_events,
618 };
619 
620 static int sr_open(struct cdrom_device_info *cdi, int purpose)
621 {
622 	struct scsi_cd *cd = cdi->handle;
623 	struct scsi_device *sdev = cd->device;
624 	int retval;
625 
626 	/*
627 	 * If the device is in error recovery, wait until it is done.
628 	 * If the device is offline, then disallow any access to it.
629 	 */
630 	retval = -ENXIO;
631 	if (!scsi_block_when_processing_errors(sdev))
632 		goto error_out;
633 
634 	return 0;
635 
636 error_out:
637 	return retval;
638 }
639 
640 static void sr_release(struct cdrom_device_info *cdi)
641 {
642 }
643 
644 static int sr_probe(struct device *dev)
645 {
646 	struct scsi_device *sdev = to_scsi_device(dev);
647 	struct gendisk *disk;
648 	struct scsi_cd *cd;
649 	int minor, error;
650 
651 	scsi_autopm_get_device(sdev);
652 	error = -ENODEV;
653 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
654 		goto fail;
655 
656 	error = -ENOMEM;
657 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
658 	if (!cd)
659 		goto fail;
660 
661 	kref_init(&cd->kref);
662 
663 	disk = alloc_disk(1);
664 	if (!disk)
665 		goto fail_free;
666 	mutex_init(&cd->lock);
667 
668 	spin_lock(&sr_index_lock);
669 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
670 	if (minor == SR_DISKS) {
671 		spin_unlock(&sr_index_lock);
672 		error = -EBUSY;
673 		goto fail_put;
674 	}
675 	__set_bit(minor, sr_index_bits);
676 	spin_unlock(&sr_index_lock);
677 
678 	disk->major = SCSI_CDROM_MAJOR;
679 	disk->first_minor = minor;
680 	sprintf(disk->disk_name, "sr%d", minor);
681 	disk->fops = &sr_bdops;
682 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
683 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
684 	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
685 
686 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
687 
688 	cd->device = sdev;
689 	cd->disk = disk;
690 	cd->driver = &sr_template;
691 	cd->disk = disk;
692 	cd->capacity = 0x1fffff;
693 	cd->device->changed = 1;	/* force recheck CD type */
694 	cd->media_present = 1;
695 	cd->use = 1;
696 	cd->readcd_known = 0;
697 	cd->readcd_cdda = 0;
698 
699 	cd->cdi.ops = &sr_dops;
700 	cd->cdi.handle = cd;
701 	cd->cdi.mask = 0;
702 	cd->cdi.capacity = 1;
703 	sprintf(cd->cdi.name, "sr%d", minor);
704 
705 	sdev->sector_size = 2048;	/* A guess, just in case */
706 
707 	/* FIXME: need to handle a get_capabilities failure properly ?? */
708 	get_capabilities(cd);
709 	sr_vendor_init(cd);
710 
711 	set_capacity(disk, cd->capacity);
712 	disk->private_data = &cd->driver;
713 	disk->queue = sdev->request_queue;
714 
715 	if (register_cdrom(disk, &cd->cdi))
716 		goto fail_minor;
717 
718 	/*
719 	 * Initialize block layer runtime PM stuffs before the
720 	 * periodic event checking request gets started in add_disk.
721 	 */
722 	blk_pm_runtime_init(sdev->request_queue, dev);
723 
724 	dev_set_drvdata(dev, cd);
725 	disk->flags |= GENHD_FL_REMOVABLE;
726 	sr_revalidate_disk(cd);
727 	device_add_disk(&sdev->sdev_gendev, disk, NULL);
728 
729 	sdev_printk(KERN_DEBUG, sdev,
730 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
731 	scsi_autopm_put_device(cd->device);
732 
733 	return 0;
734 
735 fail_minor:
736 	spin_lock(&sr_index_lock);
737 	clear_bit(minor, sr_index_bits);
738 	spin_unlock(&sr_index_lock);
739 fail_put:
740 	put_disk(disk);
741 	mutex_destroy(&cd->lock);
742 fail_free:
743 	kfree(cd);
744 fail:
745 	scsi_autopm_put_device(sdev);
746 	return error;
747 }
748 
749 
750 static void get_sectorsize(struct scsi_cd *cd)
751 {
752 	unsigned char cmd[10];
753 	unsigned char buffer[8];
754 	int the_result, retries = 3;
755 	int sector_size;
756 	struct request_queue *queue;
757 
758 	do {
759 		cmd[0] = READ_CAPACITY;
760 		memset((void *) &cmd[1], 0, 9);
761 		memset(buffer, 0, sizeof(buffer));
762 
763 		/* Do the command and wait.. */
764 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
765 					      buffer, sizeof(buffer), NULL,
766 					      SR_TIMEOUT, MAX_RETRIES, NULL);
767 
768 		retries--;
769 
770 	} while (the_result && retries);
771 
772 
773 	if (the_result) {
774 		cd->capacity = 0x1fffff;
775 		sector_size = 2048;	/* A guess, just in case */
776 	} else {
777 		long last_written;
778 
779 		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
780 		/*
781 		 * READ_CAPACITY doesn't return the correct size on
782 		 * certain UDF media.  If last_written is larger, use
783 		 * it instead.
784 		 *
785 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
786 		 */
787 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
788 			cd->capacity = max_t(long, cd->capacity, last_written);
789 
790 		sector_size = get_unaligned_be32(&buffer[4]);
791 		switch (sector_size) {
792 			/*
793 			 * HP 4020i CD-Recorder reports 2340 byte sectors
794 			 * Philips CD-Writers report 2352 byte sectors
795 			 *
796 			 * Use 2k sectors for them..
797 			 */
798 		case 0:
799 		case 2340:
800 		case 2352:
801 			sector_size = 2048;
802 			fallthrough;
803 		case 2048:
804 			cd->capacity *= 4;
805 			fallthrough;
806 		case 512:
807 			break;
808 		default:
809 			sr_printk(KERN_INFO, cd,
810 				  "unsupported sector size %d.", sector_size);
811 			cd->capacity = 0;
812 		}
813 
814 		cd->device->sector_size = sector_size;
815 
816 		/*
817 		 * Add this so that we have the ability to correctly gauge
818 		 * what the device is capable of.
819 		 */
820 		set_capacity(cd->disk, cd->capacity);
821 	}
822 
823 	queue = cd->device->request_queue;
824 	blk_queue_logical_block_size(queue, sector_size);
825 
826 	return;
827 }
828 
829 static void get_capabilities(struct scsi_cd *cd)
830 {
831 	unsigned char *buffer;
832 	struct scsi_mode_data data;
833 	struct scsi_sense_hdr sshdr;
834 	unsigned int ms_len = 128;
835 	int rc, n;
836 
837 	static const char *loadmech[] =
838 	{
839 		"caddy",
840 		"tray",
841 		"pop-up",
842 		"",
843 		"changer",
844 		"cartridge changer",
845 		"",
846 		""
847 	};
848 
849 
850 	/* allocate transfer buffer */
851 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
852 	if (!buffer) {
853 		sr_printk(KERN_ERR, cd, "out of memory.\n");
854 		return;
855 	}
856 
857 	/* eat unit attentions */
858 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
859 
860 	/* ask for mode page 0x2a */
861 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
862 			     SR_TIMEOUT, 3, &data, NULL);
863 
864 	if (rc < 0 || data.length > ms_len ||
865 	    data.header_length + data.block_descriptor_length > data.length) {
866 		/* failed, drive doesn't have capabilities mode page */
867 		cd->cdi.speed = 1;
868 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
869 				 CDC_DVD | CDC_DVD_RAM |
870 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
871 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
872 		kfree(buffer);
873 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
874 		return;
875 	}
876 
877 	n = data.header_length + data.block_descriptor_length;
878 	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
879 	cd->readcd_known = 1;
880 	cd->readcd_cdda = buffer[n + 5] & 0x01;
881 	/* print some capability bits */
882 	sr_printk(KERN_INFO, cd,
883 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
884 		  get_unaligned_be16(&buffer[n + 14]) / 176,
885 		  cd->cdi.speed,
886 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
887 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
888 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
889 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
890 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
891 		  loadmech[buffer[n + 6] >> 5]);
892 	if ((buffer[n + 6] >> 5) == 0)
893 		/* caddy drives can't close tray... */
894 		cd->cdi.mask |= CDC_CLOSE_TRAY;
895 	if ((buffer[n + 2] & 0x8) == 0)
896 		/* not a DVD drive */
897 		cd->cdi.mask |= CDC_DVD;
898 	if ((buffer[n + 3] & 0x20) == 0)
899 		/* can't write DVD-RAM media */
900 		cd->cdi.mask |= CDC_DVD_RAM;
901 	if ((buffer[n + 3] & 0x10) == 0)
902 		/* can't write DVD-R media */
903 		cd->cdi.mask |= CDC_DVD_R;
904 	if ((buffer[n + 3] & 0x2) == 0)
905 		/* can't write CD-RW media */
906 		cd->cdi.mask |= CDC_CD_RW;
907 	if ((buffer[n + 3] & 0x1) == 0)
908 		/* can't write CD-R media */
909 		cd->cdi.mask |= CDC_CD_R;
910 	if ((buffer[n + 6] & 0x8) == 0)
911 		/* can't eject */
912 		cd->cdi.mask |= CDC_OPEN_TRAY;
913 
914 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
915 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
916 		cd->cdi.capacity =
917 		    cdrom_number_of_slots(&cd->cdi);
918 	if (cd->cdi.capacity <= 1)
919 		/* not a changer */
920 		cd->cdi.mask |= CDC_SELECT_DISC;
921 	/*else    I don't think it can close its tray
922 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
923 
924 	/*
925 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
926 	 */
927 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
928 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
929 		cd->writeable = 1;
930 	}
931 
932 	kfree(buffer);
933 }
934 
935 /*
936  * sr_packet() is the entry point for the generic commands generated
937  * by the Uniform CD-ROM layer.
938  */
939 static int sr_packet(struct cdrom_device_info *cdi,
940 		struct packet_command *cgc)
941 {
942 	struct scsi_cd *cd = cdi->handle;
943 	struct scsi_device *sdev = cd->device;
944 
945 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
946 		return -EDRIVE_CANT_DO_THIS;
947 
948 	if (cgc->timeout <= 0)
949 		cgc->timeout = IOCTL_TIMEOUT;
950 
951 	sr_do_ioctl(cd, cgc);
952 
953 	return cgc->stat;
954 }
955 
956 static int sr_read_cdda_bpc(struct cdrom_device_info *cdi, void __user *ubuf,
957 		u32 lba, u32 nr, u8 *last_sense)
958 {
959 	struct gendisk *disk = cdi->disk;
960 	u32 len = nr * CD_FRAMESIZE_RAW;
961 	struct scsi_request *req;
962 	struct request *rq;
963 	struct bio *bio;
964 	int ret;
965 
966 	rq = blk_get_request(disk->queue, REQ_OP_DRV_IN, 0);
967 	if (IS_ERR(rq))
968 		return PTR_ERR(rq);
969 	req = scsi_req(rq);
970 
971 	ret = blk_rq_map_user(disk->queue, rq, NULL, ubuf, len, GFP_KERNEL);
972 	if (ret)
973 		goto out_put_request;
974 
975 	req->cmd[0] = GPCMD_READ_CD;
976 	req->cmd[1] = 1 << 2;
977 	req->cmd[2] = (lba >> 24) & 0xff;
978 	req->cmd[3] = (lba >> 16) & 0xff;
979 	req->cmd[4] = (lba >>  8) & 0xff;
980 	req->cmd[5] = lba & 0xff;
981 	req->cmd[6] = (nr >> 16) & 0xff;
982 	req->cmd[7] = (nr >>  8) & 0xff;
983 	req->cmd[8] = nr & 0xff;
984 	req->cmd[9] = 0xf8;
985 	req->cmd_len = 12;
986 	rq->timeout = 60 * HZ;
987 	bio = rq->bio;
988 
989 	blk_execute_rq(disk, rq, 0);
990 	if (scsi_req(rq)->result) {
991 		struct scsi_sense_hdr sshdr;
992 
993 		scsi_normalize_sense(req->sense, req->sense_len,
994 				     &sshdr);
995 		*last_sense = sshdr.sense_key;
996 		ret = -EIO;
997 	}
998 
999 	if (blk_rq_unmap_user(bio))
1000 		ret = -EFAULT;
1001 out_put_request:
1002 	blk_put_request(rq);
1003 	return ret;
1004 }
1005 
1006 
1007 /**
1008  *	sr_kref_release - Called to free the scsi_cd structure
1009  *	@kref: pointer to embedded kref
1010  *
1011  *	sr_ref_mutex must be held entering this routine.  Because it is
1012  *	called on last put, you should always use the scsi_cd_get()
1013  *	scsi_cd_put() helpers which manipulate the semaphore directly
1014  *	and never do a direct kref_put().
1015  **/
1016 static void sr_kref_release(struct kref *kref)
1017 {
1018 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1019 	struct gendisk *disk = cd->disk;
1020 
1021 	spin_lock(&sr_index_lock);
1022 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1023 	spin_unlock(&sr_index_lock);
1024 
1025 	unregister_cdrom(&cd->cdi);
1026 
1027 	disk->private_data = NULL;
1028 
1029 	put_disk(disk);
1030 
1031 	mutex_destroy(&cd->lock);
1032 
1033 	kfree(cd);
1034 }
1035 
1036 static int sr_remove(struct device *dev)
1037 {
1038 	struct scsi_cd *cd = dev_get_drvdata(dev);
1039 
1040 	scsi_autopm_get_device(cd->device);
1041 
1042 	del_gendisk(cd->disk);
1043 	dev_set_drvdata(dev, NULL);
1044 
1045 	mutex_lock(&sr_ref_mutex);
1046 	kref_put(&cd->kref, sr_kref_release);
1047 	mutex_unlock(&sr_ref_mutex);
1048 
1049 	return 0;
1050 }
1051 
1052 static int __init init_sr(void)
1053 {
1054 	int rc;
1055 
1056 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1057 	if (rc)
1058 		return rc;
1059 	rc = scsi_register_driver(&sr_template.gendrv);
1060 	if (rc)
1061 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1062 
1063 	return rc;
1064 }
1065 
1066 static void __exit exit_sr(void)
1067 {
1068 	scsi_unregister_driver(&sr_template.gendrv);
1069 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1070 }
1071 
1072 module_init(init_sr);
1073 module_exit(exit_sr);
1074 MODULE_LICENSE("GPL");
1075