xref: /openbmc/linux/drivers/scsi/sr.c (revision 43ffe817)
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 	/*
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 			scmd_printk(KERN_INFO, SCpnt,
429 				    "can't switch blocksize: in interrupt\n");
430 	}
431 
432 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
433 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
434 		goto out;
435 	}
436 
437 	switch (req_op(rq)) {
438 	case REQ_OP_WRITE:
439 		if (!cd->writeable)
440 			goto out;
441 		SCpnt->cmnd[0] = WRITE_10;
442 		cd->cdi.media_written = 1;
443 		break;
444 	case REQ_OP_READ:
445 		SCpnt->cmnd[0] = READ_10;
446 		break;
447 	default:
448 		blk_dump_rq_flags(rq, "Unknown sr command");
449 		goto out;
450 	}
451 
452 	{
453 		struct scatterlist *sg;
454 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
455 
456 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
457 			size += sg->length;
458 
459 		if (size != scsi_bufflen(SCpnt)) {
460 			scmd_printk(KERN_ERR, SCpnt,
461 				"mismatch count %d, bytes %d\n",
462 				size, scsi_bufflen(SCpnt));
463 			if (scsi_bufflen(SCpnt) > size)
464 				SCpnt->sdb.length = size;
465 		}
466 	}
467 
468 	/*
469 	 * request doesn't start on hw block boundary, add scatter pads
470 	 */
471 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
472 	    (scsi_bufflen(SCpnt) % s_size)) {
473 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
474 		goto out;
475 	}
476 
477 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
478 
479 
480 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
481 					"%s %d/%u 512 byte blocks.\n",
482 					(rq_data_dir(rq) == WRITE) ?
483 					"writing" : "reading",
484 					this_count, blk_rq_sectors(rq)));
485 
486 	SCpnt->cmnd[1] = 0;
487 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
488 
489 	if (this_count > 0xffff) {
490 		this_count = 0xffff;
491 		SCpnt->sdb.length = this_count * s_size;
492 	}
493 
494 	put_unaligned_be32(block, &SCpnt->cmnd[2]);
495 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
496 	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
497 
498 	/*
499 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
500 	 * host adapter, it's safe to assume that we can at least transfer
501 	 * this many bytes between each connect / disconnect.
502 	 */
503 	SCpnt->transfersize = cd->device->sector_size;
504 	SCpnt->underflow = this_count << 9;
505 	SCpnt->allowed = MAX_RETRIES;
506 	SCpnt->cmd_len = 10;
507 
508 	/*
509 	 * This indicates that the command is ready from our end to be queued.
510 	 */
511 	return BLK_STS_OK;
512  out:
513 	scsi_free_sgtables(SCpnt);
514 	return BLK_STS_IOERR;
515 }
516 
517 static void sr_revalidate_disk(struct scsi_cd *cd)
518 {
519 	struct scsi_sense_hdr sshdr;
520 
521 	/* if the unit is not ready, nothing more to do */
522 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
523 		return;
524 	sr_cd_check(&cd->cdi);
525 	get_sectorsize(cd);
526 }
527 
528 static int sr_block_open(struct block_device *bdev, fmode_t mode)
529 {
530 	struct scsi_cd *cd;
531 	struct scsi_device *sdev;
532 	int ret = -ENXIO;
533 
534 	cd = scsi_cd_get(bdev->bd_disk);
535 	if (!cd)
536 		goto out;
537 
538 	sdev = cd->device;
539 	scsi_autopm_get_device(sdev);
540 	if (bdev_check_media_change(bdev))
541 		sr_revalidate_disk(cd);
542 
543 	mutex_lock(&cd->lock);
544 	ret = cdrom_open(&cd->cdi, bdev, mode);
545 	mutex_unlock(&cd->lock);
546 
547 	scsi_autopm_put_device(sdev);
548 	if (ret)
549 		scsi_cd_put(cd);
550 
551 out:
552 	return ret;
553 }
554 
555 static void sr_block_release(struct gendisk *disk, fmode_t mode)
556 {
557 	struct scsi_cd *cd = scsi_cd(disk);
558 
559 	mutex_lock(&cd->lock);
560 	cdrom_release(&cd->cdi, mode);
561 	mutex_unlock(&cd->lock);
562 
563 	scsi_cd_put(cd);
564 }
565 
566 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
567 			  unsigned long arg)
568 {
569 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
570 	struct scsi_device *sdev = cd->device;
571 	void __user *argp = (void __user *)arg;
572 	int ret;
573 
574 	mutex_lock(&cd->lock);
575 
576 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
577 			(mode & FMODE_NDELAY) != 0);
578 	if (ret)
579 		goto out;
580 
581 	scsi_autopm_get_device(sdev);
582 
583 	/*
584 	 * Send SCSI addressing ioctls directly to mid level, send other
585 	 * ioctls to cdrom/block level.
586 	 */
587 	switch (cmd) {
588 	case SCSI_IOCTL_GET_IDLUN:
589 	case SCSI_IOCTL_GET_BUS_NUMBER:
590 		ret = scsi_ioctl(sdev, cmd, argp);
591 		goto put;
592 	}
593 
594 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
595 	if (ret != -ENOSYS)
596 		goto put;
597 
598 	ret = scsi_ioctl(sdev, cmd, argp);
599 
600 put:
601 	scsi_autopm_put_device(sdev);
602 
603 out:
604 	mutex_unlock(&cd->lock);
605 	return ret;
606 }
607 
608 #ifdef CONFIG_COMPAT
609 static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
610 			  unsigned long arg)
611 {
612 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
613 	struct scsi_device *sdev = cd->device;
614 	void __user *argp = compat_ptr(arg);
615 	int ret;
616 
617 	mutex_lock(&cd->lock);
618 
619 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
620 			(mode & FMODE_NDELAY) != 0);
621 	if (ret)
622 		goto out;
623 
624 	scsi_autopm_get_device(sdev);
625 
626 	/*
627 	 * Send SCSI addressing ioctls directly to mid level, send other
628 	 * ioctls to cdrom/block level.
629 	 */
630 	switch (cmd) {
631 	case SCSI_IOCTL_GET_IDLUN:
632 	case SCSI_IOCTL_GET_BUS_NUMBER:
633 		ret = scsi_compat_ioctl(sdev, cmd, argp);
634 		goto put;
635 	}
636 
637 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
638 	if (ret != -ENOSYS)
639 		goto put;
640 
641 	ret = scsi_compat_ioctl(sdev, cmd, argp);
642 
643 put:
644 	scsi_autopm_put_device(sdev);
645 
646 out:
647 	mutex_unlock(&cd->lock);
648 	return ret;
649 
650 }
651 #endif
652 
653 static unsigned int sr_block_check_events(struct gendisk *disk,
654 					  unsigned int clearing)
655 {
656 	unsigned int ret = 0;
657 	struct scsi_cd *cd;
658 
659 	cd = scsi_cd_get(disk);
660 	if (!cd)
661 		return 0;
662 
663 	if (!atomic_read(&cd->device->disk_events_disable_depth))
664 		ret = cdrom_check_events(&cd->cdi, clearing);
665 
666 	scsi_cd_put(cd);
667 	return ret;
668 }
669 
670 static const struct block_device_operations sr_bdops =
671 {
672 	.owner		= THIS_MODULE,
673 	.open		= sr_block_open,
674 	.release	= sr_block_release,
675 	.ioctl		= sr_block_ioctl,
676 #ifdef CONFIG_COMPAT
677 	.compat_ioctl	= sr_block_compat_ioctl,
678 #endif
679 	.check_events	= sr_block_check_events,
680 };
681 
682 static int sr_open(struct cdrom_device_info *cdi, int purpose)
683 {
684 	struct scsi_cd *cd = cdi->handle;
685 	struct scsi_device *sdev = cd->device;
686 	int retval;
687 
688 	/*
689 	 * If the device is in error recovery, wait until it is done.
690 	 * If the device is offline, then disallow any access to it.
691 	 */
692 	retval = -ENXIO;
693 	if (!scsi_block_when_processing_errors(sdev))
694 		goto error_out;
695 
696 	return 0;
697 
698 error_out:
699 	return retval;
700 }
701 
702 static void sr_release(struct cdrom_device_info *cdi)
703 {
704 	struct scsi_cd *cd = cdi->handle;
705 
706 	if (cd->device->sector_size > 2048)
707 		sr_set_blocklength(cd, 2048);
708 
709 }
710 
711 static int sr_probe(struct device *dev)
712 {
713 	struct scsi_device *sdev = to_scsi_device(dev);
714 	struct gendisk *disk;
715 	struct scsi_cd *cd;
716 	int minor, error;
717 
718 	scsi_autopm_get_device(sdev);
719 	error = -ENODEV;
720 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
721 		goto fail;
722 
723 	error = -ENOMEM;
724 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
725 	if (!cd)
726 		goto fail;
727 
728 	kref_init(&cd->kref);
729 
730 	disk = alloc_disk(1);
731 	if (!disk)
732 		goto fail_free;
733 	mutex_init(&cd->lock);
734 
735 	spin_lock(&sr_index_lock);
736 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
737 	if (minor == SR_DISKS) {
738 		spin_unlock(&sr_index_lock);
739 		error = -EBUSY;
740 		goto fail_put;
741 	}
742 	__set_bit(minor, sr_index_bits);
743 	spin_unlock(&sr_index_lock);
744 
745 	disk->major = SCSI_CDROM_MAJOR;
746 	disk->first_minor = minor;
747 	sprintf(disk->disk_name, "sr%d", minor);
748 	disk->fops = &sr_bdops;
749 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
750 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
751 	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
752 
753 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
754 
755 	cd->device = sdev;
756 	cd->disk = disk;
757 	cd->driver = &sr_template;
758 	cd->disk = disk;
759 	cd->capacity = 0x1fffff;
760 	cd->device->changed = 1;	/* force recheck CD type */
761 	cd->media_present = 1;
762 	cd->use = 1;
763 	cd->readcd_known = 0;
764 	cd->readcd_cdda = 0;
765 
766 	cd->cdi.ops = &sr_dops;
767 	cd->cdi.handle = cd;
768 	cd->cdi.mask = 0;
769 	cd->cdi.capacity = 1;
770 	sprintf(cd->cdi.name, "sr%d", minor);
771 
772 	sdev->sector_size = 2048;	/* A guess, just in case */
773 
774 	/* FIXME: need to handle a get_capabilities failure properly ?? */
775 	get_capabilities(cd);
776 	sr_vendor_init(cd);
777 
778 	set_capacity(disk, cd->capacity);
779 	disk->private_data = &cd->driver;
780 	disk->queue = sdev->request_queue;
781 
782 	if (register_cdrom(disk, &cd->cdi))
783 		goto fail_minor;
784 
785 	/*
786 	 * Initialize block layer runtime PM stuffs before the
787 	 * periodic event checking request gets started in add_disk.
788 	 */
789 	blk_pm_runtime_init(sdev->request_queue, dev);
790 
791 	dev_set_drvdata(dev, cd);
792 	disk->flags |= GENHD_FL_REMOVABLE;
793 	sr_revalidate_disk(cd);
794 	device_add_disk(&sdev->sdev_gendev, disk, NULL);
795 
796 	sdev_printk(KERN_DEBUG, sdev,
797 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
798 	scsi_autopm_put_device(cd->device);
799 
800 	return 0;
801 
802 fail_minor:
803 	spin_lock(&sr_index_lock);
804 	clear_bit(minor, sr_index_bits);
805 	spin_unlock(&sr_index_lock);
806 fail_put:
807 	put_disk(disk);
808 	mutex_destroy(&cd->lock);
809 fail_free:
810 	kfree(cd);
811 fail:
812 	scsi_autopm_put_device(sdev);
813 	return error;
814 }
815 
816 
817 static void get_sectorsize(struct scsi_cd *cd)
818 {
819 	unsigned char cmd[10];
820 	unsigned char buffer[8];
821 	int the_result, retries = 3;
822 	int sector_size;
823 	struct request_queue *queue;
824 
825 	do {
826 		cmd[0] = READ_CAPACITY;
827 		memset((void *) &cmd[1], 0, 9);
828 		memset(buffer, 0, sizeof(buffer));
829 
830 		/* Do the command and wait.. */
831 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
832 					      buffer, sizeof(buffer), NULL,
833 					      SR_TIMEOUT, MAX_RETRIES, NULL);
834 
835 		retries--;
836 
837 	} while (the_result && retries);
838 
839 
840 	if (the_result) {
841 		cd->capacity = 0x1fffff;
842 		sector_size = 2048;	/* A guess, just in case */
843 	} else {
844 		long last_written;
845 
846 		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
847 		/*
848 		 * READ_CAPACITY doesn't return the correct size on
849 		 * certain UDF media.  If last_written is larger, use
850 		 * it instead.
851 		 *
852 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
853 		 */
854 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
855 			cd->capacity = max_t(long, cd->capacity, last_written);
856 
857 		sector_size = get_unaligned_be32(&buffer[4]);
858 		switch (sector_size) {
859 			/*
860 			 * HP 4020i CD-Recorder reports 2340 byte sectors
861 			 * Philips CD-Writers report 2352 byte sectors
862 			 *
863 			 * Use 2k sectors for them..
864 			 */
865 		case 0:
866 		case 2340:
867 		case 2352:
868 			sector_size = 2048;
869 			fallthrough;
870 		case 2048:
871 			cd->capacity *= 4;
872 			fallthrough;
873 		case 512:
874 			break;
875 		default:
876 			sr_printk(KERN_INFO, cd,
877 				  "unsupported sector size %d.", sector_size);
878 			cd->capacity = 0;
879 		}
880 
881 		cd->device->sector_size = sector_size;
882 
883 		/*
884 		 * Add this so that we have the ability to correctly gauge
885 		 * what the device is capable of.
886 		 */
887 		set_capacity(cd->disk, cd->capacity);
888 	}
889 
890 	queue = cd->device->request_queue;
891 	blk_queue_logical_block_size(queue, sector_size);
892 
893 	return;
894 }
895 
896 static void get_capabilities(struct scsi_cd *cd)
897 {
898 	unsigned char *buffer;
899 	struct scsi_mode_data data;
900 	struct scsi_sense_hdr sshdr;
901 	unsigned int ms_len = 128;
902 	int rc, n;
903 
904 	static const char *loadmech[] =
905 	{
906 		"caddy",
907 		"tray",
908 		"pop-up",
909 		"",
910 		"changer",
911 		"cartridge changer",
912 		"",
913 		""
914 	};
915 
916 
917 	/* allocate transfer buffer */
918 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
919 	if (!buffer) {
920 		sr_printk(KERN_ERR, cd, "out of memory.\n");
921 		return;
922 	}
923 
924 	/* eat unit attentions */
925 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
926 
927 	/* ask for mode page 0x2a */
928 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
929 			     SR_TIMEOUT, 3, &data, NULL);
930 
931 	if (!scsi_status_is_good(rc) || data.length > ms_len ||
932 	    data.header_length + data.block_descriptor_length > data.length) {
933 		/* failed, drive doesn't have capabilities mode page */
934 		cd->cdi.speed = 1;
935 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
936 				 CDC_DVD | CDC_DVD_RAM |
937 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
938 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
939 		kfree(buffer);
940 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
941 		return;
942 	}
943 
944 	n = data.header_length + data.block_descriptor_length;
945 	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
946 	cd->readcd_known = 1;
947 	cd->readcd_cdda = buffer[n + 5] & 0x01;
948 	/* print some capability bits */
949 	sr_printk(KERN_INFO, cd,
950 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
951 		  get_unaligned_be16(&buffer[n + 14]) / 176,
952 		  cd->cdi.speed,
953 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
954 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
955 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
956 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
957 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
958 		  loadmech[buffer[n + 6] >> 5]);
959 	if ((buffer[n + 6] >> 5) == 0)
960 		/* caddy drives can't close tray... */
961 		cd->cdi.mask |= CDC_CLOSE_TRAY;
962 	if ((buffer[n + 2] & 0x8) == 0)
963 		/* not a DVD drive */
964 		cd->cdi.mask |= CDC_DVD;
965 	if ((buffer[n + 3] & 0x20) == 0)
966 		/* can't write DVD-RAM media */
967 		cd->cdi.mask |= CDC_DVD_RAM;
968 	if ((buffer[n + 3] & 0x10) == 0)
969 		/* can't write DVD-R media */
970 		cd->cdi.mask |= CDC_DVD_R;
971 	if ((buffer[n + 3] & 0x2) == 0)
972 		/* can't write CD-RW media */
973 		cd->cdi.mask |= CDC_CD_RW;
974 	if ((buffer[n + 3] & 0x1) == 0)
975 		/* can't write CD-R media */
976 		cd->cdi.mask |= CDC_CD_R;
977 	if ((buffer[n + 6] & 0x8) == 0)
978 		/* can't eject */
979 		cd->cdi.mask |= CDC_OPEN_TRAY;
980 
981 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
982 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
983 		cd->cdi.capacity =
984 		    cdrom_number_of_slots(&cd->cdi);
985 	if (cd->cdi.capacity <= 1)
986 		/* not a changer */
987 		cd->cdi.mask |= CDC_SELECT_DISC;
988 	/*else    I don't think it can close its tray
989 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
990 
991 	/*
992 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
993 	 */
994 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
995 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
996 		cd->writeable = 1;
997 	}
998 
999 	kfree(buffer);
1000 }
1001 
1002 /*
1003  * sr_packet() is the entry point for the generic commands generated
1004  * by the Uniform CD-ROM layer.
1005  */
1006 static int sr_packet(struct cdrom_device_info *cdi,
1007 		struct packet_command *cgc)
1008 {
1009 	struct scsi_cd *cd = cdi->handle;
1010 	struct scsi_device *sdev = cd->device;
1011 
1012 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
1013 		return -EDRIVE_CANT_DO_THIS;
1014 
1015 	if (cgc->timeout <= 0)
1016 		cgc->timeout = IOCTL_TIMEOUT;
1017 
1018 	sr_do_ioctl(cd, cgc);
1019 
1020 	return cgc->stat;
1021 }
1022 
1023 /**
1024  *	sr_kref_release - Called to free the scsi_cd structure
1025  *	@kref: pointer to embedded kref
1026  *
1027  *	sr_ref_mutex must be held entering this routine.  Because it is
1028  *	called on last put, you should always use the scsi_cd_get()
1029  *	scsi_cd_put() helpers which manipulate the semaphore directly
1030  *	and never do a direct kref_put().
1031  **/
1032 static void sr_kref_release(struct kref *kref)
1033 {
1034 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1035 	struct gendisk *disk = cd->disk;
1036 
1037 	spin_lock(&sr_index_lock);
1038 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1039 	spin_unlock(&sr_index_lock);
1040 
1041 	unregister_cdrom(&cd->cdi);
1042 
1043 	disk->private_data = NULL;
1044 
1045 	put_disk(disk);
1046 
1047 	mutex_destroy(&cd->lock);
1048 
1049 	kfree(cd);
1050 }
1051 
1052 static int sr_remove(struct device *dev)
1053 {
1054 	struct scsi_cd *cd = dev_get_drvdata(dev);
1055 
1056 	scsi_autopm_get_device(cd->device);
1057 
1058 	del_gendisk(cd->disk);
1059 	dev_set_drvdata(dev, NULL);
1060 
1061 	mutex_lock(&sr_ref_mutex);
1062 	kref_put(&cd->kref, sr_kref_release);
1063 	mutex_unlock(&sr_ref_mutex);
1064 
1065 	return 0;
1066 }
1067 
1068 static int __init init_sr(void)
1069 {
1070 	int rc;
1071 
1072 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1073 	if (rc)
1074 		return rc;
1075 	rc = scsi_register_driver(&sr_template.gendrv);
1076 	if (rc)
1077 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1078 
1079 	return rc;
1080 }
1081 
1082 static void __exit exit_sr(void)
1083 {
1084 	scsi_unregister_driver(&sr_template.gendrv);
1085 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1086 }
1087 
1088 module_init(init_sr);
1089 module_exit(exit_sr);
1090 MODULE_LICENSE("GPL");
1091