xref: /openbmc/linux/drivers/scsi/sr.c (revision 643d1f7f)
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 <asm/uaccess.h>
48 
49 #include <scsi/scsi.h>
50 #include <scsi/scsi_dbg.h>
51 #include <scsi/scsi_device.h>
52 #include <scsi/scsi_driver.h>
53 #include <scsi/scsi_cmnd.h>
54 #include <scsi/scsi_eh.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
57 
58 #include "scsi_logging.h"
59 #include "sr.h"
60 
61 
62 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
63 MODULE_LICENSE("GPL");
64 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
65 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
66 MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
67 
68 #define SR_DISKS	256
69 
70 #define SR_CAPABILITIES \
71 	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
72 	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
73 	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
74 	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
75 	 CDC_MRW|CDC_MRW_W|CDC_RAM)
76 
77 static int sr_probe(struct device *);
78 static int sr_remove(struct device *);
79 static int sr_done(struct scsi_cmnd *);
80 
81 static struct scsi_driver sr_template = {
82 	.owner			= THIS_MODULE,
83 	.gendrv = {
84 		.name   	= "sr",
85 		.probe		= sr_probe,
86 		.remove		= sr_remove,
87 	},
88 	.done			= sr_done,
89 };
90 
91 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
92 static DEFINE_SPINLOCK(sr_index_lock);
93 
94 /* This semaphore is used to mediate the 0->1 reference get in the
95  * face of object destruction (i.e. we can't allow a get on an
96  * object after last put) */
97 static DEFINE_MUTEX(sr_ref_mutex);
98 
99 static int sr_open(struct cdrom_device_info *, int);
100 static void sr_release(struct cdrom_device_info *);
101 
102 static void get_sectorsize(struct scsi_cd *);
103 static void get_capabilities(struct scsi_cd *);
104 
105 static int sr_media_change(struct cdrom_device_info *, int);
106 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
107 
108 static struct cdrom_device_ops sr_dops = {
109 	.open			= sr_open,
110 	.release	 	= sr_release,
111 	.drive_status	 	= sr_drive_status,
112 	.media_changed		= sr_media_change,
113 	.tray_move		= sr_tray_move,
114 	.lock_door		= sr_lock_door,
115 	.select_speed		= sr_select_speed,
116 	.get_last_session	= sr_get_last_session,
117 	.get_mcn		= sr_get_mcn,
118 	.reset			= sr_reset,
119 	.audio_ioctl		= sr_audio_ioctl,
120 	.capability		= SR_CAPABILITIES,
121 	.generic_packet		= sr_packet,
122 };
123 
124 static void sr_kref_release(struct kref *kref);
125 
126 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
127 {
128 	return container_of(disk->private_data, struct scsi_cd, driver);
129 }
130 
131 /*
132  * The get and put routines for the struct scsi_cd.  Note this entity
133  * has a scsi_device pointer and owns a reference to this.
134  */
135 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
136 {
137 	struct scsi_cd *cd = NULL;
138 
139 	mutex_lock(&sr_ref_mutex);
140 	if (disk->private_data == NULL)
141 		goto out;
142 	cd = scsi_cd(disk);
143 	kref_get(&cd->kref);
144 	if (scsi_device_get(cd->device))
145 		goto out_put;
146 	goto out;
147 
148  out_put:
149 	kref_put(&cd->kref, sr_kref_release);
150 	cd = NULL;
151  out:
152 	mutex_unlock(&sr_ref_mutex);
153 	return cd;
154 }
155 
156 static void scsi_cd_put(struct scsi_cd *cd)
157 {
158 	struct scsi_device *sdev = cd->device;
159 
160 	mutex_lock(&sr_ref_mutex);
161 	kref_put(&cd->kref, sr_kref_release);
162 	scsi_device_put(sdev);
163 	mutex_unlock(&sr_ref_mutex);
164 }
165 
166 /*
167  * This function checks to see if the media has been changed in the
168  * CDROM drive.  It is possible that we have already sensed a change,
169  * or the drive may have sensed one and not yet reported it.  We must
170  * be ready for either case. This function always reports the current
171  * value of the changed bit.  If flag is 0, then the changed bit is reset.
172  * This function could be done as an ioctl, but we would need to have
173  * an inode for that to work, and we do not always have one.
174  */
175 
176 static int sr_media_change(struct cdrom_device_info *cdi, int slot)
177 {
178 	struct scsi_cd *cd = cdi->handle;
179 	int retval;
180 	struct scsi_sense_hdr *sshdr;
181 
182 	if (CDSL_CURRENT != slot) {
183 		/* no changer support */
184 		return -EINVAL;
185 	}
186 
187 	sshdr =  kzalloc(sizeof(*sshdr), GFP_KERNEL);
188 	retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES,
189 				      sshdr);
190 	if (retval || (scsi_sense_valid(sshdr) &&
191 		       /* 0x3a is medium not present */
192 		       sshdr->asc == 0x3a)) {
193 		/* Media not present or unable to test, unit probably not
194 		 * ready. This usually means there is no disc in the drive.
195 		 * Mark as changed, and we will figure it out later once
196 		 * the drive is available again.
197 		 */
198 		cd->device->changed = 1;
199 		/* This will force a flush, if called from check_disk_change */
200 		retval = 1;
201 		goto out;
202 	};
203 
204 	retval = cd->device->changed;
205 	cd->device->changed = 0;
206 	/* If the disk changed, the capacity will now be different,
207 	 * so we force a re-read of this information */
208 	if (retval) {
209 		/* check multisession offset etc */
210 		sr_cd_check(cdi);
211 		get_sectorsize(cd);
212 	}
213 
214 out:
215 	/* Notify userspace, that media has changed. */
216 	if (retval != cd->previous_state)
217 		sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
218 				     GFP_KERNEL);
219 	cd->previous_state = retval;
220 	kfree(sshdr);
221 
222 	return retval;
223 }
224 
225 /*
226  * sr_done is the interrupt routine for the device driver.
227  *
228  * It will be notified on the end of a SCSI read / write, and will take one
229  * of several actions based on success or failure.
230  */
231 static int sr_done(struct scsi_cmnd *SCpnt)
232 {
233 	int result = SCpnt->result;
234 	int this_count = scsi_bufflen(SCpnt);
235 	int good_bytes = (result == 0 ? this_count : 0);
236 	int block_sectors = 0;
237 	long error_sector;
238 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
239 
240 #ifdef DEBUG
241 	printk("sr.c done: %x\n", result);
242 #endif
243 
244 	/*
245 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
246 	 * success.  Since this is a relatively rare error condition, no
247 	 * care is taken to avoid unnecessary additional work such as
248 	 * memcpy's that could be avoided.
249 	 */
250 	if (driver_byte(result) != 0 &&		/* An error occurred */
251 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
252 		switch (SCpnt->sense_buffer[2]) {
253 		case MEDIUM_ERROR:
254 		case VOLUME_OVERFLOW:
255 		case ILLEGAL_REQUEST:
256 			if (!(SCpnt->sense_buffer[0] & 0x90))
257 				break;
258 			error_sector = (SCpnt->sense_buffer[3] << 24) |
259 				(SCpnt->sense_buffer[4] << 16) |
260 				(SCpnt->sense_buffer[5] << 8) |
261 				SCpnt->sense_buffer[6];
262 			if (SCpnt->request->bio != NULL)
263 				block_sectors =
264 					bio_sectors(SCpnt->request->bio);
265 			if (block_sectors < 4)
266 				block_sectors = 4;
267 			if (cd->device->sector_size == 2048)
268 				error_sector <<= 2;
269 			error_sector &= ~(block_sectors - 1);
270 			good_bytes = (error_sector - SCpnt->request->sector) << 9;
271 			if (good_bytes < 0 || good_bytes >= this_count)
272 				good_bytes = 0;
273 			/*
274 			 * The SCSI specification allows for the value
275 			 * returned by READ CAPACITY to be up to 75 2K
276 			 * sectors past the last readable block.
277 			 * Therefore, if we hit a medium error within the
278 			 * last 75 2K sectors, we decrease the saved size
279 			 * value.
280 			 */
281 			if (error_sector < get_capacity(cd->disk) &&
282 			    cd->capacity - error_sector < 4 * 75)
283 				set_capacity(cd->disk, error_sector);
284 			break;
285 
286 		case RECOVERED_ERROR:
287 
288 			/*
289 			 * An error occured, but it recovered.  Inform the
290 			 * user, but make sure that it's not treated as a
291 			 * hard error.
292 			 */
293 			scsi_print_sense("sr", SCpnt);
294 			SCpnt->result = 0;
295 			SCpnt->sense_buffer[0] = 0x0;
296 			good_bytes = this_count;
297 			break;
298 
299 		default:
300 			break;
301 		}
302 	}
303 
304 	return good_bytes;
305 }
306 
307 static int sr_prep_fn(struct request_queue *q, struct request *rq)
308 {
309 	int block=0, this_count, s_size, timeout = SR_TIMEOUT;
310 	struct scsi_cd *cd;
311 	struct scsi_cmnd *SCpnt;
312 	struct scsi_device *sdp = q->queuedata;
313 	int ret;
314 
315 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
316 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
317 		goto out;
318 	} else if (rq->cmd_type != REQ_TYPE_FS) {
319 		ret = BLKPREP_KILL;
320 		goto out;
321 	}
322 	ret = scsi_setup_fs_cmnd(sdp, rq);
323 	if (ret != BLKPREP_OK)
324 		goto out;
325 	SCpnt = rq->special;
326 	cd = scsi_cd(rq->rq_disk);
327 
328 	/* from here on until we're complete, any goto out
329 	 * is used for a killable error condition */
330 	ret = BLKPREP_KILL;
331 
332 	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
333 				cd->disk->disk_name, block));
334 
335 	if (!cd->device || !scsi_device_online(cd->device)) {
336 		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
337 					rq->nr_sectors));
338 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
339 		goto out;
340 	}
341 
342 	if (cd->device->changed) {
343 		/*
344 		 * quietly refuse to do anything to a changed disc until the
345 		 * changed bit has been reset
346 		 */
347 		goto out;
348 	}
349 
350 	/*
351 	 * we do lazy blocksize switching (when reading XA sectors,
352 	 * see CDROMREADMODE2 ioctl)
353 	 */
354 	s_size = cd->device->sector_size;
355 	if (s_size > 2048) {
356 		if (!in_interrupt())
357 			sr_set_blocklength(cd, 2048);
358 		else
359 			printk("sr: can't switch blocksize: in interrupt\n");
360 	}
361 
362 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
363 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
364 		goto out;
365 	}
366 
367 	if (rq_data_dir(rq) == WRITE) {
368 		if (!cd->device->writeable)
369 			goto out;
370 		SCpnt->cmnd[0] = WRITE_10;
371 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
372  	 	cd->cdi.media_written = 1;
373 	} else if (rq_data_dir(rq) == READ) {
374 		SCpnt->cmnd[0] = READ_10;
375 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
376 	} else {
377 		blk_dump_rq_flags(rq, "Unknown sr command");
378 		goto out;
379 	}
380 
381 	{
382 		struct scatterlist *sg;
383 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
384 
385 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
386 			size += sg->length;
387 
388 		if (size != scsi_bufflen(SCpnt)) {
389 			scmd_printk(KERN_ERR, SCpnt,
390 				"mismatch count %d, bytes %d\n",
391 				size, scsi_bufflen(SCpnt));
392 			if (scsi_bufflen(SCpnt) > size)
393 				SCpnt->sdb.length = size;
394 		}
395 	}
396 
397 	/*
398 	 * request doesn't start on hw block boundary, add scatter pads
399 	 */
400 	if (((unsigned int)rq->sector % (s_size >> 9)) ||
401 	    (scsi_bufflen(SCpnt) % s_size)) {
402 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
403 		goto out;
404 	}
405 
406 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
407 
408 
409 	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
410 				cd->cdi.name,
411 				(rq_data_dir(rq) == WRITE) ?
412 					"writing" : "reading",
413 				this_count, rq->nr_sectors));
414 
415 	SCpnt->cmnd[1] = 0;
416 	block = (unsigned int)rq->sector / (s_size >> 9);
417 
418 	if (this_count > 0xffff) {
419 		this_count = 0xffff;
420 		SCpnt->sdb.length = this_count * s_size;
421 	}
422 
423 	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
424 	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
425 	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
426 	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
427 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
428 	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
429 	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
430 
431 	/*
432 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
433 	 * host adapter, it's safe to assume that we can at least transfer
434 	 * this many bytes between each connect / disconnect.
435 	 */
436 	SCpnt->transfersize = cd->device->sector_size;
437 	SCpnt->underflow = this_count << 9;
438 	SCpnt->allowed = MAX_RETRIES;
439 	SCpnt->timeout_per_command = timeout;
440 
441 	/*
442 	 * This indicates that the command is ready from our end to be
443 	 * queued.
444 	 */
445 	ret = BLKPREP_OK;
446  out:
447 	return scsi_prep_return(q, rq, ret);
448 }
449 
450 static int sr_block_open(struct inode *inode, struct file *file)
451 {
452 	struct gendisk *disk = inode->i_bdev->bd_disk;
453 	struct scsi_cd *cd;
454 	int ret = 0;
455 
456 	if(!(cd = scsi_cd_get(disk)))
457 		return -ENXIO;
458 
459 	if((ret = cdrom_open(&cd->cdi, inode, file)) != 0)
460 		scsi_cd_put(cd);
461 
462 	return ret;
463 }
464 
465 static int sr_block_release(struct inode *inode, struct file *file)
466 {
467 	int ret;
468 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
469 	ret = cdrom_release(&cd->cdi, file);
470 	if(ret)
471 		return ret;
472 
473 	scsi_cd_put(cd);
474 
475 	return 0;
476 }
477 
478 static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
479 			  unsigned long arg)
480 {
481 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
482 	struct scsi_device *sdev = cd->device;
483 	void __user *argp = (void __user *)arg;
484 	int ret;
485 
486 	/*
487 	 * Send SCSI addressing ioctls directly to mid level, send other
488 	 * ioctls to cdrom/block level.
489 	 */
490 	switch (cmd) {
491 	case SCSI_IOCTL_GET_IDLUN:
492 	case SCSI_IOCTL_GET_BUS_NUMBER:
493 		return scsi_ioctl(sdev, cmd, argp);
494 	}
495 
496 	ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
497 	if (ret != -ENOSYS)
498 		return ret;
499 
500 	/*
501 	 * ENODEV means that we didn't recognise the ioctl, or that we
502 	 * cannot execute it in the current device state.  In either
503 	 * case fall through to scsi_ioctl, which will return ENDOEV again
504 	 * if it doesn't recognise the ioctl
505 	 */
506 	ret = scsi_nonblockable_ioctl(sdev, cmd, argp, NULL);
507 	if (ret != -ENODEV)
508 		return ret;
509 	return scsi_ioctl(sdev, cmd, argp);
510 }
511 
512 static int sr_block_media_changed(struct gendisk *disk)
513 {
514 	struct scsi_cd *cd = scsi_cd(disk);
515 	return cdrom_media_changed(&cd->cdi);
516 }
517 
518 static struct block_device_operations sr_bdops =
519 {
520 	.owner		= THIS_MODULE,
521 	.open		= sr_block_open,
522 	.release	= sr_block_release,
523 	.ioctl		= sr_block_ioctl,
524 	.media_changed	= sr_block_media_changed,
525 	/*
526 	 * No compat_ioctl for now because sr_block_ioctl never
527 	 * seems to pass arbitary ioctls down to host drivers.
528 	 */
529 };
530 
531 static int sr_open(struct cdrom_device_info *cdi, int purpose)
532 {
533 	struct scsi_cd *cd = cdi->handle;
534 	struct scsi_device *sdev = cd->device;
535 	int retval;
536 
537 	/*
538 	 * If the device is in error recovery, wait until it is done.
539 	 * If the device is offline, then disallow any access to it.
540 	 */
541 	retval = -ENXIO;
542 	if (!scsi_block_when_processing_errors(sdev))
543 		goto error_out;
544 
545 	return 0;
546 
547 error_out:
548 	return retval;
549 }
550 
551 static void sr_release(struct cdrom_device_info *cdi)
552 {
553 	struct scsi_cd *cd = cdi->handle;
554 
555 	if (cd->device->sector_size > 2048)
556 		sr_set_blocklength(cd, 2048);
557 
558 }
559 
560 static int sr_probe(struct device *dev)
561 {
562 	struct scsi_device *sdev = to_scsi_device(dev);
563 	struct gendisk *disk;
564 	struct scsi_cd *cd;
565 	int minor, error;
566 
567 	error = -ENODEV;
568 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
569 		goto fail;
570 
571 	error = -ENOMEM;
572 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
573 	if (!cd)
574 		goto fail;
575 
576 	kref_init(&cd->kref);
577 
578 	disk = alloc_disk(1);
579 	if (!disk)
580 		goto fail_free;
581 
582 	spin_lock(&sr_index_lock);
583 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
584 	if (minor == SR_DISKS) {
585 		spin_unlock(&sr_index_lock);
586 		error = -EBUSY;
587 		goto fail_put;
588 	}
589 	__set_bit(minor, sr_index_bits);
590 	spin_unlock(&sr_index_lock);
591 
592 	disk->major = SCSI_CDROM_MAJOR;
593 	disk->first_minor = minor;
594 	sprintf(disk->disk_name, "sr%d", minor);
595 	disk->fops = &sr_bdops;
596 	disk->flags = GENHD_FL_CD;
597 
598 	cd->device = sdev;
599 	cd->disk = disk;
600 	cd->driver = &sr_template;
601 	cd->disk = disk;
602 	cd->capacity = 0x1fffff;
603 	cd->device->changed = 1;	/* force recheck CD type */
604 	cd->use = 1;
605 	cd->readcd_known = 0;
606 	cd->readcd_cdda = 0;
607 
608 	cd->cdi.ops = &sr_dops;
609 	cd->cdi.handle = cd;
610 	cd->cdi.mask = 0;
611 	cd->cdi.capacity = 1;
612 	sprintf(cd->cdi.name, "sr%d", minor);
613 
614 	sdev->sector_size = 2048;	/* A guess, just in case */
615 
616 	/* FIXME: need to handle a get_capabilities failure properly ?? */
617 	get_capabilities(cd);
618 	blk_queue_prep_rq(sdev->request_queue, sr_prep_fn);
619 	sr_vendor_init(cd);
620 
621 	disk->driverfs_dev = &sdev->sdev_gendev;
622 	set_capacity(disk, cd->capacity);
623 	disk->private_data = &cd->driver;
624 	disk->queue = sdev->request_queue;
625 	cd->cdi.disk = disk;
626 
627 	if (register_cdrom(&cd->cdi))
628 		goto fail_put;
629 
630 	dev_set_drvdata(dev, cd);
631 	disk->flags |= GENHD_FL_REMOVABLE;
632 	add_disk(disk);
633 
634 	sdev_printk(KERN_DEBUG, sdev,
635 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
636 	return 0;
637 
638 fail_put:
639 	put_disk(disk);
640 fail_free:
641 	kfree(cd);
642 fail:
643 	return error;
644 }
645 
646 
647 static void get_sectorsize(struct scsi_cd *cd)
648 {
649 	unsigned char cmd[10];
650 	unsigned char *buffer;
651 	int the_result, retries = 3;
652 	int sector_size;
653 	struct request_queue *queue;
654 
655 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
656 	if (!buffer)
657 		goto Enomem;
658 
659 	do {
660 		cmd[0] = READ_CAPACITY;
661 		memset((void *) &cmd[1], 0, 9);
662 		memset(buffer, 0, 8);
663 
664 		/* Do the command and wait.. */
665 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
666 					      buffer, 8, NULL, SR_TIMEOUT,
667 					      MAX_RETRIES);
668 
669 		retries--;
670 
671 	} while (the_result && retries);
672 
673 
674 	if (the_result) {
675 		cd->capacity = 0x1fffff;
676 		sector_size = 2048;	/* A guess, just in case */
677 	} else {
678 #if 0
679 		if (cdrom_get_last_written(&cd->cdi,
680 					   &cd->capacity))
681 #endif
682 			cd->capacity = 1 + ((buffer[0] << 24) |
683 						    (buffer[1] << 16) |
684 						    (buffer[2] << 8) |
685 						    buffer[3]);
686 		sector_size = (buffer[4] << 24) |
687 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
688 		switch (sector_size) {
689 			/*
690 			 * HP 4020i CD-Recorder reports 2340 byte sectors
691 			 * Philips CD-Writers report 2352 byte sectors
692 			 *
693 			 * Use 2k sectors for them..
694 			 */
695 		case 0:
696 		case 2340:
697 		case 2352:
698 			sector_size = 2048;
699 			/* fall through */
700 		case 2048:
701 			cd->capacity *= 4;
702 			/* fall through */
703 		case 512:
704 			break;
705 		default:
706 			printk("%s: unsupported sector size %d.\n",
707 			       cd->cdi.name, sector_size);
708 			cd->capacity = 0;
709 		}
710 
711 		cd->device->sector_size = sector_size;
712 
713 		/*
714 		 * Add this so that we have the ability to correctly gauge
715 		 * what the device is capable of.
716 		 */
717 		set_capacity(cd->disk, cd->capacity);
718 	}
719 
720 	queue = cd->device->request_queue;
721 	blk_queue_hardsect_size(queue, sector_size);
722 out:
723 	kfree(buffer);
724 	return;
725 
726 Enomem:
727 	cd->capacity = 0x1fffff;
728 	cd->device->sector_size = 2048;	/* A guess, just in case */
729 	goto out;
730 }
731 
732 static void get_capabilities(struct scsi_cd *cd)
733 {
734 	unsigned char *buffer;
735 	struct scsi_mode_data data;
736 	unsigned char cmd[MAX_COMMAND_SIZE];
737 	struct scsi_sense_hdr sshdr;
738 	unsigned int the_result;
739 	int retries, rc, n;
740 
741 	static const char *loadmech[] =
742 	{
743 		"caddy",
744 		"tray",
745 		"pop-up",
746 		"",
747 		"changer",
748 		"cartridge changer",
749 		"",
750 		""
751 	};
752 
753 
754 	/* allocate transfer buffer */
755 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
756 	if (!buffer) {
757 		printk(KERN_ERR "sr: out of memory.\n");
758 		return;
759 	}
760 
761 	/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
762 	 * conditions are gone, or a timeout happens
763 	 */
764 	retries = 0;
765 	do {
766 		memset((void *)cmd, 0, MAX_COMMAND_SIZE);
767 		cmd[0] = TEST_UNIT_READY;
768 
769 		the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL,
770 					       0, &sshdr, SR_TIMEOUT,
771 					       MAX_RETRIES);
772 
773 		retries++;
774 	} while (retries < 5 &&
775 		 (!scsi_status_is_good(the_result) ||
776 		  (scsi_sense_valid(&sshdr) &&
777 		   sshdr.sense_key == UNIT_ATTENTION)));
778 
779 	/* ask for mode page 0x2a */
780 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
781 			     SR_TIMEOUT, 3, &data, NULL);
782 
783 	if (!scsi_status_is_good(rc)) {
784 		/* failed, drive doesn't have capabilities mode page */
785 		cd->cdi.speed = 1;
786 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
787 				 CDC_DVD | CDC_DVD_RAM |
788 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
789 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
790 		kfree(buffer);
791 		printk("%s: scsi-1 drive\n", cd->cdi.name);
792 		return;
793 	}
794 
795 	n = data.header_length + data.block_descriptor_length;
796 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
797 	cd->readcd_known = 1;
798 	cd->readcd_cdda = buffer[n + 5] & 0x01;
799 	/* print some capability bits */
800 	printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
801 	       ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
802 	       cd->cdi.speed,
803 	       buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
804 	       buffer[n + 3] & 0x20 ? "dvd-ram " : "",
805 	       buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
806 	       buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
807 	       buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
808 	       loadmech[buffer[n + 6] >> 5]);
809 	if ((buffer[n + 6] >> 5) == 0)
810 		/* caddy drives can't close tray... */
811 		cd->cdi.mask |= CDC_CLOSE_TRAY;
812 	if ((buffer[n + 2] & 0x8) == 0)
813 		/* not a DVD drive */
814 		cd->cdi.mask |= CDC_DVD;
815 	if ((buffer[n + 3] & 0x20) == 0)
816 		/* can't write DVD-RAM media */
817 		cd->cdi.mask |= CDC_DVD_RAM;
818 	if ((buffer[n + 3] & 0x10) == 0)
819 		/* can't write DVD-R media */
820 		cd->cdi.mask |= CDC_DVD_R;
821 	if ((buffer[n + 3] & 0x2) == 0)
822 		/* can't write CD-RW media */
823 		cd->cdi.mask |= CDC_CD_RW;
824 	if ((buffer[n + 3] & 0x1) == 0)
825 		/* can't write CD-R media */
826 		cd->cdi.mask |= CDC_CD_R;
827 	if ((buffer[n + 6] & 0x8) == 0)
828 		/* can't eject */
829 		cd->cdi.mask |= CDC_OPEN_TRAY;
830 
831 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
832 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
833 		cd->cdi.capacity =
834 		    cdrom_number_of_slots(&cd->cdi);
835 	if (cd->cdi.capacity <= 1)
836 		/* not a changer */
837 		cd->cdi.mask |= CDC_SELECT_DISC;
838 	/*else    I don't think it can close its tray
839 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
840 
841 	/*
842 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
843 	 */
844 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
845 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
846 		cd->device->writeable = 1;
847 	}
848 
849 	kfree(buffer);
850 }
851 
852 /*
853  * sr_packet() is the entry point for the generic commands generated
854  * by the Uniform CD-ROM layer.
855  */
856 static int sr_packet(struct cdrom_device_info *cdi,
857 		struct packet_command *cgc)
858 {
859 	if (cgc->timeout <= 0)
860 		cgc->timeout = IOCTL_TIMEOUT;
861 
862 	sr_do_ioctl(cdi->handle, cgc);
863 
864 	return cgc->stat;
865 }
866 
867 /**
868  *	sr_kref_release - Called to free the scsi_cd structure
869  *	@kref: pointer to embedded kref
870  *
871  *	sr_ref_mutex must be held entering this routine.  Because it is
872  *	called on last put, you should always use the scsi_cd_get()
873  *	scsi_cd_put() helpers which manipulate the semaphore directly
874  *	and never do a direct kref_put().
875  **/
876 static void sr_kref_release(struct kref *kref)
877 {
878 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
879 	struct gendisk *disk = cd->disk;
880 
881 	spin_lock(&sr_index_lock);
882 	clear_bit(disk->first_minor, sr_index_bits);
883 	spin_unlock(&sr_index_lock);
884 
885 	unregister_cdrom(&cd->cdi);
886 
887 	disk->private_data = NULL;
888 
889 	put_disk(disk);
890 
891 	kfree(cd);
892 }
893 
894 static int sr_remove(struct device *dev)
895 {
896 	struct scsi_cd *cd = dev_get_drvdata(dev);
897 
898 	del_gendisk(cd->disk);
899 
900 	mutex_lock(&sr_ref_mutex);
901 	kref_put(&cd->kref, sr_kref_release);
902 	mutex_unlock(&sr_ref_mutex);
903 
904 	return 0;
905 }
906 
907 static int __init init_sr(void)
908 {
909 	int rc;
910 
911 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
912 	if (rc)
913 		return rc;
914 	rc = scsi_register_driver(&sr_template.gendrv);
915 	if (rc)
916 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
917 
918 	return rc;
919 }
920 
921 static void __exit exit_sr(void)
922 {
923 	scsi_unregister_driver(&sr_template.gendrv);
924 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
925 }
926 
927 module_init(init_sr);
928 module_exit(exit_sr);
929 MODULE_LICENSE("GPL");
930