1/*
2 *  sr.c Copyright (C) 1992 David Giller
3 *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 *
5 *  adapted from:
6 *      sd.c Copyright (C) 1992 Drew Eckhardt
7 *      Linux scsi disk driver by
8 *              Drew Eckhardt <drew@colorado.edu>
9 *
10 *	Modified by Eric Youngdale ericy@andante.org to
11 *	add scatter-gather, multiple outstanding request, and other
12 *	enhancements.
13 *
14 *      Modified by Eric Youngdale eric@andante.org to support loadable
15 *      low-level scsi drivers.
16 *
17 *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
18 *      provide auto-eject.
19 *
20 *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
21 *      generic cdrom interface
22 *
23 *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
24 *      interface, capabilities probe additions, ioctl cleanups, etc.
25 *
26 *	Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
27 *
28 *	Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
29 *	transparently and lose the GHOST hack
30 *
31 *	Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
32 *	check resource allocation in sr_init and some cleanups
33 */
34
35#include <linux/module.h>
36#include <linux/fs.h>
37#include <linux/kernel.h>
38#include <linux/mm.h>
39#include <linux/bio.h>
40#include <linux/string.h>
41#include <linux/errno.h>
42#include <linux/cdrom.h>
43#include <linux/interrupt.h>
44#include <linux/init.h>
45#include <linux/blkdev.h>
46#include <linux/mutex.h>
47#include <linux/slab.h>
48#include <linux/pm_runtime.h>
49#include <asm/uaccess.h>
50
51#include <scsi/scsi.h>
52#include <scsi/scsi_dbg.h>
53#include <scsi/scsi_device.h>
54#include <scsi/scsi_driver.h>
55#include <scsi/scsi_cmnd.h>
56#include <scsi/scsi_eh.h>
57#include <scsi/scsi_host.h>
58#include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
59
60#include "scsi_logging.h"
61#include "sr.h"
62
63
64MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
65MODULE_LICENSE("GPL");
66MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
67MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
68MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
69
70#define SR_DISKS	256
71
72#define SR_CAPABILITIES \
73	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
74	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
75	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
76	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
77	 CDC_MRW|CDC_MRW_W|CDC_RAM)
78
79static DEFINE_MUTEX(sr_mutex);
80static int sr_probe(struct device *);
81static int sr_remove(struct device *);
82static int sr_init_command(struct scsi_cmnd *SCpnt);
83static int sr_done(struct scsi_cmnd *);
84static int sr_runtime_suspend(struct device *dev);
85
86static struct dev_pm_ops sr_pm_ops = {
87	.runtime_suspend	= sr_runtime_suspend,
88};
89
90static struct scsi_driver sr_template = {
91	.gendrv = {
92		.name   	= "sr",
93		.owner		= THIS_MODULE,
94		.probe		= sr_probe,
95		.remove		= sr_remove,
96		.pm		= &sr_pm_ops,
97	},
98	.init_command		= sr_init_command,
99	.done			= sr_done,
100};
101
102static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
103static DEFINE_SPINLOCK(sr_index_lock);
104
105/* This semaphore is used to mediate the 0->1 reference get in the
106 * face of object destruction (i.e. we can't allow a get on an
107 * object after last put) */
108static DEFINE_MUTEX(sr_ref_mutex);
109
110static int sr_open(struct cdrom_device_info *, int);
111static void sr_release(struct cdrom_device_info *);
112
113static void get_sectorsize(struct scsi_cd *);
114static void get_capabilities(struct scsi_cd *);
115
116static unsigned int sr_check_events(struct cdrom_device_info *cdi,
117				    unsigned int clearing, int slot);
118static int sr_packet(struct cdrom_device_info *, struct packet_command *);
119
120static struct cdrom_device_ops sr_dops = {
121	.open			= sr_open,
122	.release	 	= sr_release,
123	.drive_status	 	= sr_drive_status,
124	.check_events		= sr_check_events,
125	.tray_move		= sr_tray_move,
126	.lock_door		= sr_lock_door,
127	.select_speed		= sr_select_speed,
128	.get_last_session	= sr_get_last_session,
129	.get_mcn		= sr_get_mcn,
130	.reset			= sr_reset,
131	.audio_ioctl		= sr_audio_ioctl,
132	.capability		= SR_CAPABILITIES,
133	.generic_packet		= sr_packet,
134};
135
136static void sr_kref_release(struct kref *kref);
137
138static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
139{
140	return container_of(disk->private_data, struct scsi_cd, driver);
141}
142
143static int sr_runtime_suspend(struct device *dev)
144{
145	struct scsi_cd *cd = dev_get_drvdata(dev);
146
147	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
148		return 0;
149
150	if (cd->media_present)
151		return -EBUSY;
152	else
153		return 0;
154}
155
156/*
157 * The get and put routines for the struct scsi_cd.  Note this entity
158 * has a scsi_device pointer and owns a reference to this.
159 */
160static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
161{
162	struct scsi_cd *cd = NULL;
163
164	mutex_lock(&sr_ref_mutex);
165	if (disk->private_data == NULL)
166		goto out;
167	cd = scsi_cd(disk);
168	kref_get(&cd->kref);
169	if (scsi_device_get(cd->device)) {
170		kref_put(&cd->kref, sr_kref_release);
171		cd = NULL;
172	}
173 out:
174	mutex_unlock(&sr_ref_mutex);
175	return cd;
176}
177
178static void scsi_cd_put(struct scsi_cd *cd)
179{
180	struct scsi_device *sdev = cd->device;
181
182	mutex_lock(&sr_ref_mutex);
183	kref_put(&cd->kref, sr_kref_release);
184	scsi_device_put(sdev);
185	mutex_unlock(&sr_ref_mutex);
186}
187
188static unsigned int sr_get_events(struct scsi_device *sdev)
189{
190	u8 buf[8];
191	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
192		     1,			/* polled */
193		     0, 0,		/* reserved */
194		     1 << 4,		/* notification class: media */
195		     0, 0,		/* reserved */
196		     0, sizeof(buf),	/* allocation length */
197		     0,			/* control */
198	};
199	struct event_header *eh = (void *)buf;
200	struct media_event_desc *med = (void *)(buf + 4);
201	struct scsi_sense_hdr sshdr;
202	int result;
203
204	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
205				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
206	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
207		return DISK_EVENT_MEDIA_CHANGE;
208
209	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
210		return 0;
211
212	if (eh->nea || eh->notification_class != 0x4)
213		return 0;
214
215	if (med->media_event_code == 1)
216		return DISK_EVENT_EJECT_REQUEST;
217	else if (med->media_event_code == 2)
218		return DISK_EVENT_MEDIA_CHANGE;
219	return 0;
220}
221
222/*
223 * This function checks to see if the media has been changed or eject
224 * button has been pressed.  It is possible that we have already
225 * sensed a change, or the drive may have sensed one and not yet
226 * reported it.  The past events are accumulated in sdev->changed and
227 * returned together with the current state.
228 */
229static unsigned int sr_check_events(struct cdrom_device_info *cdi,
230				    unsigned int clearing, int slot)
231{
232	struct scsi_cd *cd = cdi->handle;
233	bool last_present;
234	struct scsi_sense_hdr sshdr;
235	unsigned int events;
236	int ret;
237
238	/* no changer support */
239	if (CDSL_CURRENT != slot)
240		return 0;
241
242	events = sr_get_events(cd->device);
243	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
244
245	/*
246	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
247	 * for several times in a row.  We rely on TUR only for this likely
248	 * broken device, to prevent generating incorrect media changed
249	 * events for every open().
250	 */
251	if (cd->ignore_get_event) {
252		events &= ~DISK_EVENT_MEDIA_CHANGE;
253		goto do_tur;
254	}
255
256	/*
257	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
258	 * is being cleared.  Note that there are devices which hang
259	 * if asked to execute TUR repeatedly.
260	 */
261	if (cd->device->changed) {
262		events |= DISK_EVENT_MEDIA_CHANGE;
263		cd->device->changed = 0;
264		cd->tur_changed = true;
265	}
266
267	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
268		return events;
269do_tur:
270	/* let's see whether the media is there with TUR */
271	last_present = cd->media_present;
272	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
273
274	/*
275	 * Media is considered to be present if TUR succeeds or fails with
276	 * sense data indicating something other than media-not-present
277	 * (ASC 0x3a).
278	 */
279	cd->media_present = scsi_status_is_good(ret) ||
280		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
281
282	if (last_present != cd->media_present)
283		cd->device->changed = 1;
284
285	if (cd->device->changed) {
286		events |= DISK_EVENT_MEDIA_CHANGE;
287		cd->device->changed = 0;
288		cd->tur_changed = true;
289	}
290
291	if (cd->ignore_get_event)
292		return events;
293
294	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
295	if (!cd->tur_changed) {
296		if (cd->get_event_changed) {
297			if (cd->tur_mismatch++ > 8) {
298				sr_printk(KERN_WARNING, cd,
299					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
300				cd->ignore_get_event = true;
301			}
302		} else {
303			cd->tur_mismatch = 0;
304		}
305	}
306	cd->tur_changed = false;
307	cd->get_event_changed = false;
308
309	return events;
310}
311
312/*
313 * sr_done is the interrupt routine for the device driver.
314 *
315 * It will be notified on the end of a SCSI read / write, and will take one
316 * of several actions based on success or failure.
317 */
318static int sr_done(struct scsi_cmnd *SCpnt)
319{
320	int result = SCpnt->result;
321	int this_count = scsi_bufflen(SCpnt);
322	int good_bytes = (result == 0 ? this_count : 0);
323	int block_sectors = 0;
324	long error_sector;
325	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
326
327#ifdef DEBUG
328	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
329#endif
330
331	/*
332	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
333	 * success.  Since this is a relatively rare error condition, no
334	 * care is taken to avoid unnecessary additional work such as
335	 * memcpy's that could be avoided.
336	 */
337	if (driver_byte(result) != 0 &&		/* An error occurred */
338	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
339		switch (SCpnt->sense_buffer[2]) {
340		case MEDIUM_ERROR:
341		case VOLUME_OVERFLOW:
342		case ILLEGAL_REQUEST:
343			if (!(SCpnt->sense_buffer[0] & 0x90))
344				break;
345			error_sector = (SCpnt->sense_buffer[3] << 24) |
346				(SCpnt->sense_buffer[4] << 16) |
347				(SCpnt->sense_buffer[5] << 8) |
348				SCpnt->sense_buffer[6];
349			if (SCpnt->request->bio != NULL)
350				block_sectors =
351					bio_sectors(SCpnt->request->bio);
352			if (block_sectors < 4)
353				block_sectors = 4;
354			if (cd->device->sector_size == 2048)
355				error_sector <<= 2;
356			error_sector &= ~(block_sectors - 1);
357			good_bytes = (error_sector -
358				      blk_rq_pos(SCpnt->request)) << 9;
359			if (good_bytes < 0 || good_bytes >= this_count)
360				good_bytes = 0;
361			/*
362			 * The SCSI specification allows for the value
363			 * returned by READ CAPACITY to be up to 75 2K
364			 * sectors past the last readable block.
365			 * Therefore, if we hit a medium error within the
366			 * last 75 2K sectors, we decrease the saved size
367			 * value.
368			 */
369			if (error_sector < get_capacity(cd->disk) &&
370			    cd->capacity - error_sector < 4 * 75)
371				set_capacity(cd->disk, error_sector);
372			break;
373
374		case RECOVERED_ERROR:
375			good_bytes = this_count;
376			break;
377
378		default:
379			break;
380		}
381	}
382
383	return good_bytes;
384}
385
386static int sr_init_command(struct scsi_cmnd *SCpnt)
387{
388	int block = 0, this_count, s_size;
389	struct scsi_cd *cd;
390	struct request *rq = SCpnt->request;
391	int ret;
392
393	ret = scsi_init_io(SCpnt);
394	if (ret != BLKPREP_OK)
395		goto out;
396	SCpnt = rq->special;
397	cd = scsi_cd(rq->rq_disk);
398
399	/* from here on until we're complete, any goto out
400	 * is used for a killable error condition */
401	ret = BLKPREP_KILL;
402
403	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
404		"Doing sr request, block = %d\n", block));
405
406	if (!cd->device || !scsi_device_online(cd->device)) {
407		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
408			"Finishing %u sectors\n", blk_rq_sectors(rq)));
409		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
410			"Retry with 0x%p\n", SCpnt));
411		goto out;
412	}
413
414	if (cd->device->changed) {
415		/*
416		 * quietly refuse to do anything to a changed disc until the
417		 * changed bit has been reset
418		 */
419		goto out;
420	}
421
422	/*
423	 * we do lazy blocksize switching (when reading XA sectors,
424	 * see CDROMREADMODE2 ioctl)
425	 */
426	s_size = cd->device->sector_size;
427	if (s_size > 2048) {
428		if (!in_interrupt())
429			sr_set_blocklength(cd, 2048);
430		else
431			scmd_printk(KERN_INFO, SCpnt,
432				    "can't switch blocksize: in interrupt\n");
433	}
434
435	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
436		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
437		goto out;
438	}
439
440	if (rq_data_dir(rq) == WRITE) {
441		if (!cd->writeable)
442			goto out;
443		SCpnt->cmnd[0] = WRITE_10;
444		cd->cdi.media_written = 1;
445	} else if (rq_data_dir(rq) == READ) {
446		SCpnt->cmnd[0] = READ_10;
447	} else {
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	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
495	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
496	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
497	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
498	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
499	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
500	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
501
502	/*
503	 * We shouldn't disconnect in the middle of a sector, so with a dumb
504	 * host adapter, it's safe to assume that we can at least transfer
505	 * this many bytes between each connect / disconnect.
506	 */
507	SCpnt->transfersize = cd->device->sector_size;
508	SCpnt->underflow = this_count << 9;
509	SCpnt->allowed = MAX_RETRIES;
510
511	/*
512	 * This indicates that the command is ready from our end to be
513	 * queued.
514	 */
515	ret = BLKPREP_OK;
516 out:
517	return ret;
518}
519
520static int sr_block_open(struct block_device *bdev, fmode_t mode)
521{
522	struct scsi_cd *cd;
523	int ret = -ENXIO;
524
525	mutex_lock(&sr_mutex);
526	cd = scsi_cd_get(bdev->bd_disk);
527	if (cd) {
528		ret = cdrom_open(&cd->cdi, bdev, mode);
529		if (ret)
530			scsi_cd_put(cd);
531	}
532	mutex_unlock(&sr_mutex);
533	return ret;
534}
535
536static void sr_block_release(struct gendisk *disk, fmode_t mode)
537{
538	struct scsi_cd *cd = scsi_cd(disk);
539	mutex_lock(&sr_mutex);
540	cdrom_release(&cd->cdi, mode);
541	scsi_cd_put(cd);
542	mutex_unlock(&sr_mutex);
543}
544
545static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
546			  unsigned long arg)
547{
548	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
549	struct scsi_device *sdev = cd->device;
550	void __user *argp = (void __user *)arg;
551	int ret;
552
553	mutex_lock(&sr_mutex);
554
555	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
556			(mode & FMODE_NDELAY) != 0);
557	if (ret)
558		goto out;
559
560	/*
561	 * Send SCSI addressing ioctls directly to mid level, send other
562	 * ioctls to cdrom/block level.
563	 */
564	switch (cmd) {
565	case SCSI_IOCTL_GET_IDLUN:
566	case SCSI_IOCTL_GET_BUS_NUMBER:
567		ret = scsi_ioctl(sdev, cmd, argp);
568		goto out;
569	}
570
571	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
572	if (ret != -ENOSYS)
573		goto out;
574
575	ret = scsi_ioctl(sdev, cmd, argp);
576
577out:
578	mutex_unlock(&sr_mutex);
579	return ret;
580}
581
582static unsigned int sr_block_check_events(struct gendisk *disk,
583					  unsigned int clearing)
584{
585	struct scsi_cd *cd = scsi_cd(disk);
586
587	if (atomic_read(&cd->device->disk_events_disable_depth))
588		return 0;
589
590	return cdrom_check_events(&cd->cdi, clearing);
591}
592
593static int sr_block_revalidate_disk(struct gendisk *disk)
594{
595	struct scsi_cd *cd = scsi_cd(disk);
596	struct scsi_sense_hdr sshdr;
597
598	/* if the unit is not ready, nothing more to do */
599	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
600		goto out;
601
602	sr_cd_check(&cd->cdi);
603	get_sectorsize(cd);
604out:
605	return 0;
606}
607
608static const struct block_device_operations sr_bdops =
609{
610	.owner		= THIS_MODULE,
611	.open		= sr_block_open,
612	.release	= sr_block_release,
613	.ioctl		= sr_block_ioctl,
614	.check_events	= sr_block_check_events,
615	.revalidate_disk = sr_block_revalidate_disk,
616	/*
617	 * No compat_ioctl for now because sr_block_ioctl never
618	 * seems to pass arbitrary ioctls down to host drivers.
619	 */
620};
621
622static int sr_open(struct cdrom_device_info *cdi, int purpose)
623{
624	struct scsi_cd *cd = cdi->handle;
625	struct scsi_device *sdev = cd->device;
626	int retval;
627
628	/*
629	 * If the device is in error recovery, wait until it is done.
630	 * If the device is offline, then disallow any access to it.
631	 */
632	retval = -ENXIO;
633	if (!scsi_block_when_processing_errors(sdev))
634		goto error_out;
635
636	return 0;
637
638error_out:
639	return retval;
640}
641
642static void sr_release(struct cdrom_device_info *cdi)
643{
644	struct scsi_cd *cd = cdi->handle;
645
646	if (cd->device->sector_size > 2048)
647		sr_set_blocklength(cd, 2048);
648
649}
650
651static int sr_probe(struct device *dev)
652{
653	struct scsi_device *sdev = to_scsi_device(dev);
654	struct gendisk *disk;
655	struct scsi_cd *cd;
656	int minor, error;
657
658	scsi_autopm_get_device(sdev);
659	error = -ENODEV;
660	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
661		goto fail;
662
663	error = -ENOMEM;
664	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
665	if (!cd)
666		goto fail;
667
668	kref_init(&cd->kref);
669
670	disk = alloc_disk(1);
671	if (!disk)
672		goto fail_free;
673
674	spin_lock(&sr_index_lock);
675	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
676	if (minor == SR_DISKS) {
677		spin_unlock(&sr_index_lock);
678		error = -EBUSY;
679		goto fail_put;
680	}
681	__set_bit(minor, sr_index_bits);
682	spin_unlock(&sr_index_lock);
683
684	disk->major = SCSI_CDROM_MAJOR;
685	disk->first_minor = minor;
686	sprintf(disk->disk_name, "sr%d", minor);
687	disk->fops = &sr_bdops;
688	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
689	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
690
691	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
692
693	cd->device = sdev;
694	cd->disk = disk;
695	cd->driver = &sr_template;
696	cd->disk = disk;
697	cd->capacity = 0x1fffff;
698	cd->device->changed = 1;	/* force recheck CD type */
699	cd->media_present = 1;
700	cd->use = 1;
701	cd->readcd_known = 0;
702	cd->readcd_cdda = 0;
703
704	cd->cdi.ops = &sr_dops;
705	cd->cdi.handle = cd;
706	cd->cdi.mask = 0;
707	cd->cdi.capacity = 1;
708	sprintf(cd->cdi.name, "sr%d", minor);
709
710	sdev->sector_size = 2048;	/* A guess, just in case */
711
712	/* FIXME: need to handle a get_capabilities failure properly ?? */
713	get_capabilities(cd);
714	sr_vendor_init(cd);
715
716	disk->driverfs_dev = &sdev->sdev_gendev;
717	set_capacity(disk, cd->capacity);
718	disk->private_data = &cd->driver;
719	disk->queue = sdev->request_queue;
720	cd->cdi.disk = disk;
721
722	if (register_cdrom(&cd->cdi))
723		goto fail_put;
724
725	/*
726	 * Initialize block layer runtime PM stuffs before the
727	 * periodic event checking request gets started in add_disk.
728	 */
729	blk_pm_runtime_init(sdev->request_queue, dev);
730
731	dev_set_drvdata(dev, cd);
732	disk->flags |= GENHD_FL_REMOVABLE;
733	add_disk(disk);
734
735	sdev_printk(KERN_DEBUG, sdev,
736		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
737	scsi_autopm_put_device(cd->device);
738
739	return 0;
740
741fail_put:
742	put_disk(disk);
743fail_free:
744	kfree(cd);
745fail:
746	scsi_autopm_put_device(sdev);
747	return error;
748}
749
750
751static void get_sectorsize(struct scsi_cd *cd)
752{
753	unsigned char cmd[10];
754	unsigned char buffer[8];
755	int the_result, retries = 3;
756	int sector_size;
757	struct request_queue *queue;
758
759	do {
760		cmd[0] = READ_CAPACITY;
761		memset((void *) &cmd[1], 0, 9);
762		memset(buffer, 0, sizeof(buffer));
763
764		/* Do the command and wait.. */
765		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
766					      buffer, sizeof(buffer), NULL,
767					      SR_TIMEOUT, MAX_RETRIES, NULL);
768
769		retries--;
770
771	} while (the_result && retries);
772
773
774	if (the_result) {
775		cd->capacity = 0x1fffff;
776		sector_size = 2048;	/* A guess, just in case */
777	} else {
778		long last_written;
779
780		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
781				    (buffer[2] << 8) | buffer[3]);
782		/*
783		 * READ_CAPACITY doesn't return the correct size on
784		 * certain UDF media.  If last_written is larger, use
785		 * it instead.
786		 *
787		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
788		 */
789		if (!cdrom_get_last_written(&cd->cdi, &last_written))
790			cd->capacity = max_t(long, cd->capacity, last_written);
791
792		sector_size = (buffer[4] << 24) |
793		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
794		switch (sector_size) {
795			/*
796			 * HP 4020i CD-Recorder reports 2340 byte sectors
797			 * Philips CD-Writers report 2352 byte sectors
798			 *
799			 * Use 2k sectors for them..
800			 */
801		case 0:
802		case 2340:
803		case 2352:
804			sector_size = 2048;
805			/* fall through */
806		case 2048:
807			cd->capacity *= 4;
808			/* fall through */
809		case 512:
810			break;
811		default:
812			sr_printk(KERN_INFO, cd,
813				  "unsupported sector size %d.", sector_size);
814			cd->capacity = 0;
815		}
816
817		cd->device->sector_size = sector_size;
818
819		/*
820		 * Add this so that we have the ability to correctly gauge
821		 * what the device is capable of.
822		 */
823		set_capacity(cd->disk, cd->capacity);
824	}
825
826	queue = cd->device->request_queue;
827	blk_queue_logical_block_size(queue, sector_size);
828
829	return;
830}
831
832static void get_capabilities(struct scsi_cd *cd)
833{
834	unsigned char *buffer;
835	struct scsi_mode_data data;
836	struct scsi_sense_hdr sshdr;
837	int rc, n;
838
839	static const char *loadmech[] =
840	{
841		"caddy",
842		"tray",
843		"pop-up",
844		"",
845		"changer",
846		"cartridge changer",
847		"",
848		""
849	};
850
851
852	/* allocate transfer buffer */
853	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
854	if (!buffer) {
855		sr_printk(KERN_ERR, cd, "out of memory.\n");
856		return;
857	}
858
859	/* eat unit attentions */
860	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
861
862	/* ask for mode page 0x2a */
863	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
864			     SR_TIMEOUT, 3, &data, NULL);
865
866	if (!scsi_status_is_good(rc)) {
867		/* failed, drive doesn't have capabilities mode page */
868		cd->cdi.speed = 1;
869		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
870				 CDC_DVD | CDC_DVD_RAM |
871				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
872				 CDC_MRW | CDC_MRW_W | CDC_RAM);
873		kfree(buffer);
874		sr_printk(KERN_INFO, cd, "scsi-1 drive");
875		return;
876	}
877
878	n = data.header_length + data.block_descriptor_length;
879	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
880	cd->readcd_known = 1;
881	cd->readcd_cdda = buffer[n + 5] & 0x01;
882	/* print some capability bits */
883	sr_printk(KERN_INFO, cd,
884		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
885		  ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
886		  cd->cdi.speed,
887		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
888		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
889		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
890		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
891		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
892		  loadmech[buffer[n + 6] >> 5]);
893	if ((buffer[n + 6] >> 5) == 0)
894		/* caddy drives can't close tray... */
895		cd->cdi.mask |= CDC_CLOSE_TRAY;
896	if ((buffer[n + 2] & 0x8) == 0)
897		/* not a DVD drive */
898		cd->cdi.mask |= CDC_DVD;
899	if ((buffer[n + 3] & 0x20) == 0)
900		/* can't write DVD-RAM media */
901		cd->cdi.mask |= CDC_DVD_RAM;
902	if ((buffer[n + 3] & 0x10) == 0)
903		/* can't write DVD-R media */
904		cd->cdi.mask |= CDC_DVD_R;
905	if ((buffer[n + 3] & 0x2) == 0)
906		/* can't write CD-RW media */
907		cd->cdi.mask |= CDC_CD_RW;
908	if ((buffer[n + 3] & 0x1) == 0)
909		/* can't write CD-R media */
910		cd->cdi.mask |= CDC_CD_R;
911	if ((buffer[n + 6] & 0x8) == 0)
912		/* can't eject */
913		cd->cdi.mask |= CDC_OPEN_TRAY;
914
915	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
916	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
917		cd->cdi.capacity =
918		    cdrom_number_of_slots(&cd->cdi);
919	if (cd->cdi.capacity <= 1)
920		/* not a changer */
921		cd->cdi.mask |= CDC_SELECT_DISC;
922	/*else    I don't think it can close its tray
923		cd->cdi.mask |= CDC_CLOSE_TRAY; */
924
925	/*
926	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
927	 */
928	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
929			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
930		cd->writeable = 1;
931	}
932
933	kfree(buffer);
934}
935
936/*
937 * sr_packet() is the entry point for the generic commands generated
938 * by the Uniform CD-ROM layer.
939 */
940static int sr_packet(struct cdrom_device_info *cdi,
941		struct packet_command *cgc)
942{
943	struct scsi_cd *cd = cdi->handle;
944	struct scsi_device *sdev = cd->device;
945
946	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
947		return -EDRIVE_CANT_DO_THIS;
948
949	if (cgc->timeout <= 0)
950		cgc->timeout = IOCTL_TIMEOUT;
951
952	sr_do_ioctl(cd, cgc);
953
954	return cgc->stat;
955}
956
957/**
958 *	sr_kref_release - Called to free the scsi_cd structure
959 *	@kref: pointer to embedded kref
960 *
961 *	sr_ref_mutex must be held entering this routine.  Because it is
962 *	called on last put, you should always use the scsi_cd_get()
963 *	scsi_cd_put() helpers which manipulate the semaphore directly
964 *	and never do a direct kref_put().
965 **/
966static void sr_kref_release(struct kref *kref)
967{
968	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
969	struct gendisk *disk = cd->disk;
970
971	spin_lock(&sr_index_lock);
972	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
973	spin_unlock(&sr_index_lock);
974
975	unregister_cdrom(&cd->cdi);
976
977	disk->private_data = NULL;
978
979	put_disk(disk);
980
981	kfree(cd);
982}
983
984static int sr_remove(struct device *dev)
985{
986	struct scsi_cd *cd = dev_get_drvdata(dev);
987
988	scsi_autopm_get_device(cd->device);
989
990	del_gendisk(cd->disk);
991	dev_set_drvdata(dev, NULL);
992
993	mutex_lock(&sr_ref_mutex);
994	kref_put(&cd->kref, sr_kref_release);
995	mutex_unlock(&sr_ref_mutex);
996
997	return 0;
998}
999
1000static int __init init_sr(void)
1001{
1002	int rc;
1003
1004	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1005	if (rc)
1006		return rc;
1007	rc = scsi_register_driver(&sr_template.gendrv);
1008	if (rc)
1009		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1010
1011	return rc;
1012}
1013
1014static void __exit exit_sr(void)
1015{
1016	scsi_unregister_driver(&sr_template.gendrv);
1017	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1018}
1019
1020module_init(init_sr);
1021module_exit(exit_sr);
1022MODULE_LICENSE("GPL");
1023