xref: /openbmc/linux/drivers/scsi/sr.c (revision 84b102f5)
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 
124 static const struct cdrom_device_ops sr_dops = {
125 	.open			= sr_open,
126 	.release	 	= sr_release,
127 	.drive_status	 	= sr_drive_status,
128 	.check_events		= sr_check_events,
129 	.tray_move		= sr_tray_move,
130 	.lock_door		= sr_lock_door,
131 	.select_speed		= sr_select_speed,
132 	.get_last_session	= sr_get_last_session,
133 	.get_mcn		= sr_get_mcn,
134 	.reset			= sr_reset,
135 	.audio_ioctl		= sr_audio_ioctl,
136 	.capability		= SR_CAPABILITIES,
137 	.generic_packet		= sr_packet,
138 };
139 
140 static void sr_kref_release(struct kref *kref);
141 
142 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
143 {
144 	return container_of(disk->private_data, struct scsi_cd, driver);
145 }
146 
147 static int sr_runtime_suspend(struct device *dev)
148 {
149 	struct scsi_cd *cd = dev_get_drvdata(dev);
150 
151 	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
152 		return 0;
153 
154 	if (cd->media_present)
155 		return -EBUSY;
156 	else
157 		return 0;
158 }
159 
160 /*
161  * The get and put routines for the struct scsi_cd.  Note this entity
162  * has a scsi_device pointer and owns a reference to this.
163  */
164 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
165 {
166 	struct scsi_cd *cd = NULL;
167 
168 	mutex_lock(&sr_ref_mutex);
169 	if (disk->private_data == NULL)
170 		goto out;
171 	cd = scsi_cd(disk);
172 	kref_get(&cd->kref);
173 	if (scsi_device_get(cd->device)) {
174 		kref_put(&cd->kref, sr_kref_release);
175 		cd = NULL;
176 	}
177  out:
178 	mutex_unlock(&sr_ref_mutex);
179 	return cd;
180 }
181 
182 static void scsi_cd_put(struct scsi_cd *cd)
183 {
184 	struct scsi_device *sdev = cd->device;
185 
186 	mutex_lock(&sr_ref_mutex);
187 	kref_put(&cd->kref, sr_kref_release);
188 	scsi_device_put(sdev);
189 	mutex_unlock(&sr_ref_mutex);
190 }
191 
192 static unsigned int sr_get_events(struct scsi_device *sdev)
193 {
194 	u8 buf[8];
195 	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
196 		     1,			/* polled */
197 		     0, 0,		/* reserved */
198 		     1 << 4,		/* notification class: media */
199 		     0, 0,		/* reserved */
200 		     0, sizeof(buf),	/* allocation length */
201 		     0,			/* control */
202 	};
203 	struct event_header *eh = (void *)buf;
204 	struct media_event_desc *med = (void *)(buf + 4);
205 	struct scsi_sense_hdr sshdr;
206 	int result;
207 
208 	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
209 				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
210 	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
211 		return DISK_EVENT_MEDIA_CHANGE;
212 
213 	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
214 		return 0;
215 
216 	if (eh->nea || eh->notification_class != 0x4)
217 		return 0;
218 
219 	if (med->media_event_code == 1)
220 		return DISK_EVENT_EJECT_REQUEST;
221 	else if (med->media_event_code == 2)
222 		return DISK_EVENT_MEDIA_CHANGE;
223 	return 0;
224 }
225 
226 /*
227  * This function checks to see if the media has been changed or eject
228  * button has been pressed.  It is possible that we have already
229  * sensed a change, or the drive may have sensed one and not yet
230  * reported it.  The past events are accumulated in sdev->changed and
231  * returned together with the current state.
232  */
233 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
234 				    unsigned int clearing, int slot)
235 {
236 	struct scsi_cd *cd = cdi->handle;
237 	bool last_present;
238 	struct scsi_sense_hdr sshdr;
239 	unsigned int events;
240 	int ret;
241 
242 	/* no changer support */
243 	if (CDSL_CURRENT != slot)
244 		return 0;
245 
246 	events = sr_get_events(cd->device);
247 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
248 
249 	/*
250 	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
251 	 * for several times in a row.  We rely on TUR only for this likely
252 	 * broken device, to prevent generating incorrect media changed
253 	 * events for every open().
254 	 */
255 	if (cd->ignore_get_event) {
256 		events &= ~DISK_EVENT_MEDIA_CHANGE;
257 		goto do_tur;
258 	}
259 
260 	/*
261 	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
262 	 * is being cleared.  Note that there are devices which hang
263 	 * if asked to execute TUR repeatedly.
264 	 */
265 	if (cd->device->changed) {
266 		events |= DISK_EVENT_MEDIA_CHANGE;
267 		cd->device->changed = 0;
268 		cd->tur_changed = true;
269 	}
270 
271 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
272 		return events;
273 do_tur:
274 	/* let's see whether the media is there with TUR */
275 	last_present = cd->media_present;
276 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
277 
278 	/*
279 	 * Media is considered to be present if TUR succeeds or fails with
280 	 * sense data indicating something other than media-not-present
281 	 * (ASC 0x3a).
282 	 */
283 	cd->media_present = scsi_status_is_good(ret) ||
284 		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
285 
286 	if (last_present != cd->media_present)
287 		cd->device->changed = 1;
288 
289 	if (cd->device->changed) {
290 		events |= DISK_EVENT_MEDIA_CHANGE;
291 		cd->device->changed = 0;
292 		cd->tur_changed = true;
293 	}
294 
295 	if (cd->ignore_get_event)
296 		return events;
297 
298 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
299 	if (!cd->tur_changed) {
300 		if (cd->get_event_changed) {
301 			if (cd->tur_mismatch++ > 8) {
302 				sr_printk(KERN_WARNING, cd,
303 					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
304 				cd->ignore_get_event = true;
305 			}
306 		} else {
307 			cd->tur_mismatch = 0;
308 		}
309 	}
310 	cd->tur_changed = false;
311 	cd->get_event_changed = false;
312 
313 	return events;
314 }
315 
316 /*
317  * sr_done is the interrupt routine for the device driver.
318  *
319  * It will be notified on the end of a SCSI read / write, and will take one
320  * of several actions based on success or failure.
321  */
322 static int sr_done(struct scsi_cmnd *SCpnt)
323 {
324 	int result = SCpnt->result;
325 	int this_count = scsi_bufflen(SCpnt);
326 	int good_bytes = (result == 0 ? this_count : 0);
327 	int block_sectors = 0;
328 	long error_sector;
329 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
330 
331 #ifdef DEBUG
332 	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
333 #endif
334 
335 	/*
336 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
337 	 * success.  Since this is a relatively rare error condition, no
338 	 * care is taken to avoid unnecessary additional work such as
339 	 * memcpy's that could be avoided.
340 	 */
341 	if (driver_byte(result) != 0 &&		/* An error occurred */
342 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
343 		switch (SCpnt->sense_buffer[2]) {
344 		case MEDIUM_ERROR:
345 		case VOLUME_OVERFLOW:
346 		case ILLEGAL_REQUEST:
347 			if (!(SCpnt->sense_buffer[0] & 0x90))
348 				break;
349 			error_sector =
350 				get_unaligned_be32(&SCpnt->sense_buffer[3]);
351 			if (SCpnt->request->bio != NULL)
352 				block_sectors =
353 					bio_sectors(SCpnt->request->bio);
354 			if (block_sectors < 4)
355 				block_sectors = 4;
356 			if (cd->device->sector_size == 2048)
357 				error_sector <<= 2;
358 			error_sector &= ~(block_sectors - 1);
359 			good_bytes = (error_sector -
360 				      blk_rq_pos(SCpnt->request)) << 9;
361 			if (good_bytes < 0 || good_bytes >= this_count)
362 				good_bytes = 0;
363 			/*
364 			 * The SCSI specification allows for the value
365 			 * returned by READ CAPACITY to be up to 75 2K
366 			 * sectors past the last readable block.
367 			 * Therefore, if we hit a medium error within the
368 			 * last 75 2K sectors, we decrease the saved size
369 			 * value.
370 			 */
371 			if (error_sector < get_capacity(cd->disk) &&
372 			    cd->capacity - error_sector < 4 * 75)
373 				set_capacity(cd->disk, error_sector);
374 			break;
375 
376 		case RECOVERED_ERROR:
377 			good_bytes = this_count;
378 			break;
379 
380 		default:
381 			break;
382 		}
383 	}
384 
385 	return good_bytes;
386 }
387 
388 static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
389 {
390 	int block = 0, this_count, s_size;
391 	struct scsi_cd *cd;
392 	struct request *rq = SCpnt->request;
393 	blk_status_t ret;
394 
395 	ret = scsi_alloc_sgtables(SCpnt);
396 	if (ret != BLK_STS_OK)
397 		return ret;
398 	cd = scsi_cd(rq->rq_disk);
399 
400 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
401 		"Doing sr request, block = %d\n", block));
402 
403 	if (!cd->device || !scsi_device_online(cd->device)) {
404 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
405 			"Finishing %u sectors\n", blk_rq_sectors(rq)));
406 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
407 			"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 	s_size = cd->device->sector_size;
420 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
421 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
422 		goto out;
423 	}
424 
425 	switch (req_op(rq)) {
426 	case REQ_OP_WRITE:
427 		if (!cd->writeable)
428 			goto out;
429 		SCpnt->cmnd[0] = WRITE_10;
430 		cd->cdi.media_written = 1;
431 		break;
432 	case REQ_OP_READ:
433 		SCpnt->cmnd[0] = READ_10;
434 		break;
435 	default:
436 		blk_dump_rq_flags(rq, "Unknown sr command");
437 		goto out;
438 	}
439 
440 	{
441 		struct scatterlist *sg;
442 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
443 
444 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
445 			size += sg->length;
446 
447 		if (size != scsi_bufflen(SCpnt)) {
448 			scmd_printk(KERN_ERR, SCpnt,
449 				"mismatch count %d, bytes %d\n",
450 				size, scsi_bufflen(SCpnt));
451 			if (scsi_bufflen(SCpnt) > size)
452 				SCpnt->sdb.length = size;
453 		}
454 	}
455 
456 	/*
457 	 * request doesn't start on hw block boundary, add scatter pads
458 	 */
459 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
460 	    (scsi_bufflen(SCpnt) % s_size)) {
461 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
462 		goto out;
463 	}
464 
465 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
466 
467 
468 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
469 					"%s %d/%u 512 byte blocks.\n",
470 					(rq_data_dir(rq) == WRITE) ?
471 					"writing" : "reading",
472 					this_count, blk_rq_sectors(rq)));
473 
474 	SCpnt->cmnd[1] = 0;
475 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
476 
477 	if (this_count > 0xffff) {
478 		this_count = 0xffff;
479 		SCpnt->sdb.length = this_count * s_size;
480 	}
481 
482 	put_unaligned_be32(block, &SCpnt->cmnd[2]);
483 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
484 	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
485 
486 	/*
487 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
488 	 * host adapter, it's safe to assume that we can at least transfer
489 	 * this many bytes between each connect / disconnect.
490 	 */
491 	SCpnt->transfersize = cd->device->sector_size;
492 	SCpnt->underflow = this_count << 9;
493 	SCpnt->allowed = MAX_RETRIES;
494 	SCpnt->cmd_len = 10;
495 
496 	/*
497 	 * This indicates that the command is ready from our end to be queued.
498 	 */
499 	return BLK_STS_OK;
500  out:
501 	scsi_free_sgtables(SCpnt);
502 	return BLK_STS_IOERR;
503 }
504 
505 static void sr_revalidate_disk(struct scsi_cd *cd)
506 {
507 	struct scsi_sense_hdr sshdr;
508 
509 	/* if the unit is not ready, nothing more to do */
510 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
511 		return;
512 	sr_cd_check(&cd->cdi);
513 	get_sectorsize(cd);
514 }
515 
516 static int sr_block_open(struct block_device *bdev, fmode_t mode)
517 {
518 	struct scsi_cd *cd;
519 	struct scsi_device *sdev;
520 	int ret = -ENXIO;
521 
522 	cd = scsi_cd_get(bdev->bd_disk);
523 	if (!cd)
524 		goto out;
525 
526 	sdev = cd->device;
527 	scsi_autopm_get_device(sdev);
528 	if (bdev_check_media_change(bdev))
529 		sr_revalidate_disk(cd);
530 
531 	mutex_lock(&cd->lock);
532 	ret = cdrom_open(&cd->cdi, bdev, mode);
533 	mutex_unlock(&cd->lock);
534 
535 	scsi_autopm_put_device(sdev);
536 	if (ret)
537 		scsi_cd_put(cd);
538 
539 out:
540 	return ret;
541 }
542 
543 static void sr_block_release(struct gendisk *disk, fmode_t mode)
544 {
545 	struct scsi_cd *cd = scsi_cd(disk);
546 
547 	mutex_lock(&cd->lock);
548 	cdrom_release(&cd->cdi, mode);
549 	mutex_unlock(&cd->lock);
550 
551 	scsi_cd_put(cd);
552 }
553 
554 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
555 			  unsigned long arg)
556 {
557 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
558 	struct scsi_device *sdev = cd->device;
559 	void __user *argp = (void __user *)arg;
560 	int ret;
561 
562 	mutex_lock(&cd->lock);
563 
564 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
565 			(mode & FMODE_NDELAY) != 0);
566 	if (ret)
567 		goto out;
568 
569 	scsi_autopm_get_device(sdev);
570 
571 	/*
572 	 * Send SCSI addressing ioctls directly to mid level, send other
573 	 * ioctls to cdrom/block level.
574 	 */
575 	switch (cmd) {
576 	case SCSI_IOCTL_GET_IDLUN:
577 	case SCSI_IOCTL_GET_BUS_NUMBER:
578 		ret = scsi_ioctl(sdev, cmd, argp);
579 		goto put;
580 	}
581 
582 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
583 	if (ret != -ENOSYS)
584 		goto put;
585 
586 	ret = scsi_ioctl(sdev, cmd, argp);
587 
588 put:
589 	scsi_autopm_put_device(sdev);
590 
591 out:
592 	mutex_unlock(&cd->lock);
593 	return ret;
594 }
595 
596 #ifdef CONFIG_COMPAT
597 static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
598 			  unsigned long arg)
599 {
600 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
601 	struct scsi_device *sdev = cd->device;
602 	void __user *argp = compat_ptr(arg);
603 	int ret;
604 
605 	mutex_lock(&cd->lock);
606 
607 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
608 			(mode & FMODE_NDELAY) != 0);
609 	if (ret)
610 		goto out;
611 
612 	scsi_autopm_get_device(sdev);
613 
614 	/*
615 	 * Send SCSI addressing ioctls directly to mid level, send other
616 	 * ioctls to cdrom/block level.
617 	 */
618 	switch (cmd) {
619 	case SCSI_IOCTL_GET_IDLUN:
620 	case SCSI_IOCTL_GET_BUS_NUMBER:
621 		ret = scsi_compat_ioctl(sdev, cmd, argp);
622 		goto put;
623 	}
624 
625 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
626 	if (ret != -ENOSYS)
627 		goto put;
628 
629 	ret = scsi_compat_ioctl(sdev, cmd, argp);
630 
631 put:
632 	scsi_autopm_put_device(sdev);
633 
634 out:
635 	mutex_unlock(&cd->lock);
636 	return ret;
637 
638 }
639 #endif
640 
641 static unsigned int sr_block_check_events(struct gendisk *disk,
642 					  unsigned int clearing)
643 {
644 	unsigned int ret = 0;
645 	struct scsi_cd *cd;
646 
647 	cd = scsi_cd_get(disk);
648 	if (!cd)
649 		return 0;
650 
651 	if (!atomic_read(&cd->device->disk_events_disable_depth))
652 		ret = cdrom_check_events(&cd->cdi, clearing);
653 
654 	scsi_cd_put(cd);
655 	return ret;
656 }
657 
658 static const struct block_device_operations sr_bdops =
659 {
660 	.owner		= THIS_MODULE,
661 	.open		= sr_block_open,
662 	.release	= sr_block_release,
663 	.ioctl		= sr_block_ioctl,
664 #ifdef CONFIG_COMPAT
665 	.compat_ioctl	= sr_block_compat_ioctl,
666 #endif
667 	.check_events	= sr_block_check_events,
668 };
669 
670 static int sr_open(struct cdrom_device_info *cdi, int purpose)
671 {
672 	struct scsi_cd *cd = cdi->handle;
673 	struct scsi_device *sdev = cd->device;
674 	int retval;
675 
676 	/*
677 	 * If the device is in error recovery, wait until it is done.
678 	 * If the device is offline, then disallow any access to it.
679 	 */
680 	retval = -ENXIO;
681 	if (!scsi_block_when_processing_errors(sdev))
682 		goto error_out;
683 
684 	return 0;
685 
686 error_out:
687 	return retval;
688 }
689 
690 static void sr_release(struct cdrom_device_info *cdi)
691 {
692 }
693 
694 static int sr_probe(struct device *dev)
695 {
696 	struct scsi_device *sdev = to_scsi_device(dev);
697 	struct gendisk *disk;
698 	struct scsi_cd *cd;
699 	int minor, error;
700 
701 	scsi_autopm_get_device(sdev);
702 	error = -ENODEV;
703 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
704 		goto fail;
705 
706 	error = -ENOMEM;
707 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
708 	if (!cd)
709 		goto fail;
710 
711 	kref_init(&cd->kref);
712 
713 	disk = alloc_disk(1);
714 	if (!disk)
715 		goto fail_free;
716 	mutex_init(&cd->lock);
717 
718 	spin_lock(&sr_index_lock);
719 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
720 	if (minor == SR_DISKS) {
721 		spin_unlock(&sr_index_lock);
722 		error = -EBUSY;
723 		goto fail_put;
724 	}
725 	__set_bit(minor, sr_index_bits);
726 	spin_unlock(&sr_index_lock);
727 
728 	disk->major = SCSI_CDROM_MAJOR;
729 	disk->first_minor = minor;
730 	sprintf(disk->disk_name, "sr%d", minor);
731 	disk->fops = &sr_bdops;
732 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
733 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
734 	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
735 
736 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
737 
738 	cd->device = sdev;
739 	cd->disk = disk;
740 	cd->driver = &sr_template;
741 	cd->disk = disk;
742 	cd->capacity = 0x1fffff;
743 	cd->device->changed = 1;	/* force recheck CD type */
744 	cd->media_present = 1;
745 	cd->use = 1;
746 	cd->readcd_known = 0;
747 	cd->readcd_cdda = 0;
748 
749 	cd->cdi.ops = &sr_dops;
750 	cd->cdi.handle = cd;
751 	cd->cdi.mask = 0;
752 	cd->cdi.capacity = 1;
753 	sprintf(cd->cdi.name, "sr%d", minor);
754 
755 	sdev->sector_size = 2048;	/* A guess, just in case */
756 
757 	/* FIXME: need to handle a get_capabilities failure properly ?? */
758 	get_capabilities(cd);
759 	sr_vendor_init(cd);
760 
761 	set_capacity(disk, cd->capacity);
762 	disk->private_data = &cd->driver;
763 	disk->queue = sdev->request_queue;
764 
765 	if (register_cdrom(disk, &cd->cdi))
766 		goto fail_minor;
767 
768 	/*
769 	 * Initialize block layer runtime PM stuffs before the
770 	 * periodic event checking request gets started in add_disk.
771 	 */
772 	blk_pm_runtime_init(sdev->request_queue, dev);
773 
774 	dev_set_drvdata(dev, cd);
775 	disk->flags |= GENHD_FL_REMOVABLE;
776 	sr_revalidate_disk(cd);
777 	device_add_disk(&sdev->sdev_gendev, disk, NULL);
778 
779 	sdev_printk(KERN_DEBUG, sdev,
780 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
781 	scsi_autopm_put_device(cd->device);
782 
783 	return 0;
784 
785 fail_minor:
786 	spin_lock(&sr_index_lock);
787 	clear_bit(minor, sr_index_bits);
788 	spin_unlock(&sr_index_lock);
789 fail_put:
790 	put_disk(disk);
791 	mutex_destroy(&cd->lock);
792 fail_free:
793 	kfree(cd);
794 fail:
795 	scsi_autopm_put_device(sdev);
796 	return error;
797 }
798 
799 
800 static void get_sectorsize(struct scsi_cd *cd)
801 {
802 	unsigned char cmd[10];
803 	unsigned char buffer[8];
804 	int the_result, retries = 3;
805 	int sector_size;
806 	struct request_queue *queue;
807 
808 	do {
809 		cmd[0] = READ_CAPACITY;
810 		memset((void *) &cmd[1], 0, 9);
811 		memset(buffer, 0, sizeof(buffer));
812 
813 		/* Do the command and wait.. */
814 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
815 					      buffer, sizeof(buffer), NULL,
816 					      SR_TIMEOUT, MAX_RETRIES, NULL);
817 
818 		retries--;
819 
820 	} while (the_result && retries);
821 
822 
823 	if (the_result) {
824 		cd->capacity = 0x1fffff;
825 		sector_size = 2048;	/* A guess, just in case */
826 	} else {
827 		long last_written;
828 
829 		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
830 		/*
831 		 * READ_CAPACITY doesn't return the correct size on
832 		 * certain UDF media.  If last_written is larger, use
833 		 * it instead.
834 		 *
835 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
836 		 */
837 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
838 			cd->capacity = max_t(long, cd->capacity, last_written);
839 
840 		sector_size = get_unaligned_be32(&buffer[4]);
841 		switch (sector_size) {
842 			/*
843 			 * HP 4020i CD-Recorder reports 2340 byte sectors
844 			 * Philips CD-Writers report 2352 byte sectors
845 			 *
846 			 * Use 2k sectors for them..
847 			 */
848 		case 0:
849 		case 2340:
850 		case 2352:
851 			sector_size = 2048;
852 			fallthrough;
853 		case 2048:
854 			cd->capacity *= 4;
855 			fallthrough;
856 		case 512:
857 			break;
858 		default:
859 			sr_printk(KERN_INFO, cd,
860 				  "unsupported sector size %d.", sector_size);
861 			cd->capacity = 0;
862 		}
863 
864 		cd->device->sector_size = sector_size;
865 
866 		/*
867 		 * Add this so that we have the ability to correctly gauge
868 		 * what the device is capable of.
869 		 */
870 		set_capacity(cd->disk, cd->capacity);
871 	}
872 
873 	queue = cd->device->request_queue;
874 	blk_queue_logical_block_size(queue, sector_size);
875 
876 	return;
877 }
878 
879 static void get_capabilities(struct scsi_cd *cd)
880 {
881 	unsigned char *buffer;
882 	struct scsi_mode_data data;
883 	struct scsi_sense_hdr sshdr;
884 	unsigned int ms_len = 128;
885 	int rc, n;
886 
887 	static const char *loadmech[] =
888 	{
889 		"caddy",
890 		"tray",
891 		"pop-up",
892 		"",
893 		"changer",
894 		"cartridge changer",
895 		"",
896 		""
897 	};
898 
899 
900 	/* allocate transfer buffer */
901 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
902 	if (!buffer) {
903 		sr_printk(KERN_ERR, cd, "out of memory.\n");
904 		return;
905 	}
906 
907 	/* eat unit attentions */
908 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
909 
910 	/* ask for mode page 0x2a */
911 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
912 			     SR_TIMEOUT, 3, &data, NULL);
913 
914 	if (!scsi_status_is_good(rc) || data.length > ms_len ||
915 	    data.header_length + data.block_descriptor_length > data.length) {
916 		/* failed, drive doesn't have capabilities mode page */
917 		cd->cdi.speed = 1;
918 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
919 				 CDC_DVD | CDC_DVD_RAM |
920 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
921 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
922 		kfree(buffer);
923 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
924 		return;
925 	}
926 
927 	n = data.header_length + data.block_descriptor_length;
928 	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
929 	cd->readcd_known = 1;
930 	cd->readcd_cdda = buffer[n + 5] & 0x01;
931 	/* print some capability bits */
932 	sr_printk(KERN_INFO, cd,
933 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
934 		  get_unaligned_be16(&buffer[n + 14]) / 176,
935 		  cd->cdi.speed,
936 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
937 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
938 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
939 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
940 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
941 		  loadmech[buffer[n + 6] >> 5]);
942 	if ((buffer[n + 6] >> 5) == 0)
943 		/* caddy drives can't close tray... */
944 		cd->cdi.mask |= CDC_CLOSE_TRAY;
945 	if ((buffer[n + 2] & 0x8) == 0)
946 		/* not a DVD drive */
947 		cd->cdi.mask |= CDC_DVD;
948 	if ((buffer[n + 3] & 0x20) == 0)
949 		/* can't write DVD-RAM media */
950 		cd->cdi.mask |= CDC_DVD_RAM;
951 	if ((buffer[n + 3] & 0x10) == 0)
952 		/* can't write DVD-R media */
953 		cd->cdi.mask |= CDC_DVD_R;
954 	if ((buffer[n + 3] & 0x2) == 0)
955 		/* can't write CD-RW media */
956 		cd->cdi.mask |= CDC_CD_RW;
957 	if ((buffer[n + 3] & 0x1) == 0)
958 		/* can't write CD-R media */
959 		cd->cdi.mask |= CDC_CD_R;
960 	if ((buffer[n + 6] & 0x8) == 0)
961 		/* can't eject */
962 		cd->cdi.mask |= CDC_OPEN_TRAY;
963 
964 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
965 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
966 		cd->cdi.capacity =
967 		    cdrom_number_of_slots(&cd->cdi);
968 	if (cd->cdi.capacity <= 1)
969 		/* not a changer */
970 		cd->cdi.mask |= CDC_SELECT_DISC;
971 	/*else    I don't think it can close its tray
972 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
973 
974 	/*
975 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
976 	 */
977 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
978 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
979 		cd->writeable = 1;
980 	}
981 
982 	kfree(buffer);
983 }
984 
985 /*
986  * sr_packet() is the entry point for the generic commands generated
987  * by the Uniform CD-ROM layer.
988  */
989 static int sr_packet(struct cdrom_device_info *cdi,
990 		struct packet_command *cgc)
991 {
992 	struct scsi_cd *cd = cdi->handle;
993 	struct scsi_device *sdev = cd->device;
994 
995 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
996 		return -EDRIVE_CANT_DO_THIS;
997 
998 	if (cgc->timeout <= 0)
999 		cgc->timeout = IOCTL_TIMEOUT;
1000 
1001 	sr_do_ioctl(cd, cgc);
1002 
1003 	return cgc->stat;
1004 }
1005 
1006 /**
1007  *	sr_kref_release - Called to free the scsi_cd structure
1008  *	@kref: pointer to embedded kref
1009  *
1010  *	sr_ref_mutex must be held entering this routine.  Because it is
1011  *	called on last put, you should always use the scsi_cd_get()
1012  *	scsi_cd_put() helpers which manipulate the semaphore directly
1013  *	and never do a direct kref_put().
1014  **/
1015 static void sr_kref_release(struct kref *kref)
1016 {
1017 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1018 	struct gendisk *disk = cd->disk;
1019 
1020 	spin_lock(&sr_index_lock);
1021 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1022 	spin_unlock(&sr_index_lock);
1023 
1024 	unregister_cdrom(&cd->cdi);
1025 
1026 	disk->private_data = NULL;
1027 
1028 	put_disk(disk);
1029 
1030 	mutex_destroy(&cd->lock);
1031 
1032 	kfree(cd);
1033 }
1034 
1035 static int sr_remove(struct device *dev)
1036 {
1037 	struct scsi_cd *cd = dev_get_drvdata(dev);
1038 
1039 	scsi_autopm_get_device(cd->device);
1040 
1041 	del_gendisk(cd->disk);
1042 	dev_set_drvdata(dev, NULL);
1043 
1044 	mutex_lock(&sr_ref_mutex);
1045 	kref_put(&cd->kref, sr_kref_release);
1046 	mutex_unlock(&sr_ref_mutex);
1047 
1048 	return 0;
1049 }
1050 
1051 static int __init init_sr(void)
1052 {
1053 	int rc;
1054 
1055 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1056 	if (rc)
1057 		return rc;
1058 	rc = scsi_register_driver(&sr_template.gendrv);
1059 	if (rc)
1060 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1061 
1062 	return rc;
1063 }
1064 
1065 static void __exit exit_sr(void)
1066 {
1067 	scsi_unregister_driver(&sr_template.gendrv);
1068 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1069 }
1070 
1071 module_init(init_sr);
1072 module_exit(exit_sr);
1073 MODULE_LICENSE("GPL");
1074