xref: /linux/drivers/scsi/sr.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 
66 #define SR_DISKS	256
67 
68 #define MAX_RETRIES	3
69 #define SR_TIMEOUT	(30 * HZ)
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_init_command(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 	.init_command		= sr_init_command,
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 int sr_media_change(struct cdrom_device_info *cdi, int slot)
177 {
178 	struct scsi_cd *cd = cdi->handle;
179 	int retval;
180 
181 	if (CDSL_CURRENT != slot) {
182 		/* no changer support */
183 		return -EINVAL;
184 	}
185 
186 	retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES);
187 	if (retval) {
188 		/* Unable to test, unit probably not ready.  This usually
189 		 * means there is no disc in the drive.  Mark as changed,
190 		 * and we will figure it out later once the drive is
191 		 * available again.  */
192 		cd->device->changed = 1;
193 		return 1;	/* This will force a flush, if called from
194 				 * check_disk_change */
195 	};
196 
197 	retval = cd->device->changed;
198 	cd->device->changed = 0;
199 	/* If the disk changed, the capacity will now be different,
200 	 * so we force a re-read of this information */
201 	if (retval) {
202 		/* check multisession offset etc */
203 		sr_cd_check(cdi);
204 
205 		get_sectorsize(cd);
206 	}
207 	return retval;
208 }
209 
210 /*
211  * rw_intr is the interrupt routine for the device driver.
212  *
213  * It will be notified on the end of a SCSI read / write, and will take on
214  * of several actions based on success or failure.
215  */
216 static void rw_intr(struct scsi_cmnd * SCpnt)
217 {
218 	int result = SCpnt->result;
219 	int this_count = SCpnt->request_bufflen;
220 	int good_bytes = (result == 0 ? this_count : 0);
221 	int block_sectors = 0;
222 	long error_sector;
223 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
224 
225 #ifdef DEBUG
226 	printk("sr.c done: %x\n", result);
227 #endif
228 
229 	/*
230 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
231 	 * success.  Since this is a relatively rare error condition, no
232 	 * care is taken to avoid unnecessary additional work such as
233 	 * memcpy's that could be avoided.
234 	 */
235 	if (driver_byte(result) != 0 &&		/* An error occurred */
236 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
237 		switch (SCpnt->sense_buffer[2]) {
238 		case MEDIUM_ERROR:
239 		case VOLUME_OVERFLOW:
240 		case ILLEGAL_REQUEST:
241 			if (!(SCpnt->sense_buffer[0] & 0x90))
242 				break;
243 			error_sector = (SCpnt->sense_buffer[3] << 24) |
244 				(SCpnt->sense_buffer[4] << 16) |
245 				(SCpnt->sense_buffer[5] << 8) |
246 				SCpnt->sense_buffer[6];
247 			if (SCpnt->request->bio != NULL)
248 				block_sectors =
249 					bio_sectors(SCpnt->request->bio);
250 			if (block_sectors < 4)
251 				block_sectors = 4;
252 			if (cd->device->sector_size == 2048)
253 				error_sector <<= 2;
254 			error_sector &= ~(block_sectors - 1);
255 			good_bytes = (error_sector - SCpnt->request->sector) << 9;
256 			if (good_bytes < 0 || good_bytes >= this_count)
257 				good_bytes = 0;
258 			/*
259 			 * The SCSI specification allows for the value
260 			 * returned by READ CAPACITY to be up to 75 2K
261 			 * sectors past the last readable block.
262 			 * Therefore, if we hit a medium error within the
263 			 * last 75 2K sectors, we decrease the saved size
264 			 * value.
265 			 */
266 			if (error_sector < get_capacity(cd->disk) &&
267 			    cd->capacity - error_sector < 4 * 75)
268 				set_capacity(cd->disk, error_sector);
269 			break;
270 
271 		case RECOVERED_ERROR:
272 
273 			/*
274 			 * An error occured, but it recovered.  Inform the
275 			 * user, but make sure that it's not treated as a
276 			 * hard error.
277 			 */
278 			scsi_print_sense("sr", SCpnt);
279 			SCpnt->result = 0;
280 			SCpnt->sense_buffer[0] = 0x0;
281 			good_bytes = this_count;
282 			break;
283 
284 		default:
285 			break;
286 		}
287 	}
288 
289 	/*
290 	 * This calls the generic completion function, now that we know
291 	 * how many actual sectors finished, and how many sectors we need
292 	 * to say have failed.
293 	 */
294 	scsi_io_completion(SCpnt, good_bytes);
295 }
296 
297 static int sr_init_command(struct scsi_cmnd * SCpnt)
298 {
299 	int block=0, this_count, s_size, timeout = SR_TIMEOUT;
300 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
301 
302 	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
303 				cd->disk->disk_name, block));
304 
305 	if (!cd->device || !scsi_device_online(cd->device)) {
306 		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
307 					SCpnt->request->nr_sectors));
308 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
309 		return 0;
310 	}
311 
312 	if (cd->device->changed) {
313 		/*
314 		 * quietly refuse to do anything to a changed disc until the
315 		 * changed bit has been reset
316 		 */
317 		return 0;
318 	}
319 
320 	/*
321 	 * we do lazy blocksize switching (when reading XA sectors,
322 	 * see CDROMREADMODE2 ioctl)
323 	 */
324 	s_size = cd->device->sector_size;
325 	if (s_size > 2048) {
326 		if (!in_interrupt())
327 			sr_set_blocklength(cd, 2048);
328 		else
329 			printk("sr: can't switch blocksize: in interrupt\n");
330 	}
331 
332 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
333 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
334 		return 0;
335 	}
336 
337 	if (rq_data_dir(SCpnt->request) == WRITE) {
338 		if (!cd->device->writeable)
339 			return 0;
340 		SCpnt->cmnd[0] = WRITE_10;
341 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
342  	 	cd->cdi.media_written = 1;
343 	} else if (rq_data_dir(SCpnt->request) == READ) {
344 		SCpnt->cmnd[0] = READ_10;
345 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
346 	} else {
347 		blk_dump_rq_flags(SCpnt->request, "Unknown sr command");
348 		return 0;
349 	}
350 
351 	{
352 		struct scatterlist *sg = SCpnt->request_buffer;
353 		int i, size = 0;
354 		for (i = 0; i < SCpnt->use_sg; i++)
355 			size += sg[i].length;
356 
357 		if (size != SCpnt->request_bufflen && SCpnt->use_sg) {
358 			scmd_printk(KERN_ERR, SCpnt,
359 				"mismatch count %d, bytes %d\n",
360 				size, SCpnt->request_bufflen);
361 			if (SCpnt->request_bufflen > size)
362 				SCpnt->request_bufflen = size;
363 		}
364 	}
365 
366 	/*
367 	 * request doesn't start on hw block boundary, add scatter pads
368 	 */
369 	if (((unsigned int)SCpnt->request->sector % (s_size >> 9)) ||
370 	    (SCpnt->request_bufflen % s_size)) {
371 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
372 		return 0;
373 	}
374 
375 	this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9);
376 
377 
378 	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
379 				cd->cdi.name,
380 				(rq_data_dir(SCpnt->request) == WRITE) ?
381 					"writing" : "reading",
382 				this_count, SCpnt->request->nr_sectors));
383 
384 	SCpnt->cmnd[1] = 0;
385 	block = (unsigned int)SCpnt->request->sector / (s_size >> 9);
386 
387 	if (this_count > 0xffff) {
388 		this_count = 0xffff;
389 		SCpnt->request_bufflen = this_count * s_size;
390 	}
391 
392 	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
393 	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
394 	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
395 	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
396 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
397 	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
398 	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
399 
400 	/*
401 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
402 	 * host adapter, it's safe to assume that we can at least transfer
403 	 * this many bytes between each connect / disconnect.
404 	 */
405 	SCpnt->transfersize = cd->device->sector_size;
406 	SCpnt->underflow = this_count << 9;
407 	SCpnt->allowed = MAX_RETRIES;
408 	SCpnt->timeout_per_command = timeout;
409 
410 	/*
411 	 * This is the completion routine we use.  This is matched in terms
412 	 * of capability to this function.
413 	 */
414 	SCpnt->done = rw_intr;
415 
416 	/*
417 	 * This indicates that the command is ready from our end to be
418 	 * queued.
419 	 */
420 	return 1;
421 }
422 
423 static int sr_block_open(struct inode *inode, struct file *file)
424 {
425 	struct gendisk *disk = inode->i_bdev->bd_disk;
426 	struct scsi_cd *cd;
427 	int ret = 0;
428 
429 	if(!(cd = scsi_cd_get(disk)))
430 		return -ENXIO;
431 
432 	if((ret = cdrom_open(&cd->cdi, inode, file)) != 0)
433 		scsi_cd_put(cd);
434 
435 	return ret;
436 }
437 
438 static int sr_block_release(struct inode *inode, struct file *file)
439 {
440 	int ret;
441 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
442 	ret = cdrom_release(&cd->cdi, file);
443 	if(ret)
444 		return ret;
445 
446 	scsi_cd_put(cd);
447 
448 	return 0;
449 }
450 
451 static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
452 			  unsigned long arg)
453 {
454 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
455 	struct scsi_device *sdev = cd->device;
456 	void __user *argp = (void __user *)arg;
457 	int ret;
458 
459 	/*
460 	 * Send SCSI addressing ioctls directly to mid level, send other
461 	 * ioctls to cdrom/block level.
462 	 */
463 	switch (cmd) {
464 	case SCSI_IOCTL_GET_IDLUN:
465 	case SCSI_IOCTL_GET_BUS_NUMBER:
466 		return scsi_ioctl(sdev, cmd, argp);
467 	}
468 
469 	ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
470 	if (ret != -ENOSYS)
471 		return ret;
472 
473 	/*
474 	 * ENODEV means that we didn't recognise the ioctl, or that we
475 	 * cannot execute it in the current device state.  In either
476 	 * case fall through to scsi_ioctl, which will return ENDOEV again
477 	 * if it doesn't recognise the ioctl
478 	 */
479 	ret = scsi_nonblockable_ioctl(sdev, cmd, argp, NULL);
480 	if (ret != -ENODEV)
481 		return ret;
482 	return scsi_ioctl(sdev, cmd, argp);
483 }
484 
485 static int sr_block_media_changed(struct gendisk *disk)
486 {
487 	struct scsi_cd *cd = scsi_cd(disk);
488 	return cdrom_media_changed(&cd->cdi);
489 }
490 
491 static struct block_device_operations sr_bdops =
492 {
493 	.owner		= THIS_MODULE,
494 	.open		= sr_block_open,
495 	.release	= sr_block_release,
496 	.ioctl		= sr_block_ioctl,
497 	.media_changed	= sr_block_media_changed,
498 	/*
499 	 * No compat_ioctl for now because sr_block_ioctl never
500 	 * seems to pass arbitary ioctls down to host drivers.
501 	 */
502 };
503 
504 static int sr_open(struct cdrom_device_info *cdi, int purpose)
505 {
506 	struct scsi_cd *cd = cdi->handle;
507 	struct scsi_device *sdev = cd->device;
508 	int retval;
509 
510 	/*
511 	 * If the device is in error recovery, wait until it is done.
512 	 * If the device is offline, then disallow any access to it.
513 	 */
514 	retval = -ENXIO;
515 	if (!scsi_block_when_processing_errors(sdev))
516 		goto error_out;
517 
518 	return 0;
519 
520 error_out:
521 	return retval;
522 }
523 
524 static void sr_release(struct cdrom_device_info *cdi)
525 {
526 	struct scsi_cd *cd = cdi->handle;
527 
528 	if (cd->device->sector_size > 2048)
529 		sr_set_blocklength(cd, 2048);
530 
531 }
532 
533 static int sr_probe(struct device *dev)
534 {
535 	struct scsi_device *sdev = to_scsi_device(dev);
536 	struct gendisk *disk;
537 	struct scsi_cd *cd;
538 	int minor, error;
539 
540 	error = -ENODEV;
541 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
542 		goto fail;
543 
544 	error = -ENOMEM;
545 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
546 	if (!cd)
547 		goto fail;
548 
549 	kref_init(&cd->kref);
550 
551 	disk = alloc_disk(1);
552 	if (!disk)
553 		goto fail_free;
554 
555 	spin_lock(&sr_index_lock);
556 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
557 	if (minor == SR_DISKS) {
558 		spin_unlock(&sr_index_lock);
559 		error = -EBUSY;
560 		goto fail_put;
561 	}
562 	__set_bit(minor, sr_index_bits);
563 	spin_unlock(&sr_index_lock);
564 
565 	disk->major = SCSI_CDROM_MAJOR;
566 	disk->first_minor = minor;
567 	sprintf(disk->disk_name, "sr%d", minor);
568 	disk->fops = &sr_bdops;
569 	disk->flags = GENHD_FL_CD;
570 
571 	cd->device = sdev;
572 	cd->disk = disk;
573 	cd->driver = &sr_template;
574 	cd->disk = disk;
575 	cd->capacity = 0x1fffff;
576 	cd->device->changed = 1;	/* force recheck CD type */
577 	cd->use = 1;
578 	cd->readcd_known = 0;
579 	cd->readcd_cdda = 0;
580 
581 	cd->cdi.ops = &sr_dops;
582 	cd->cdi.handle = cd;
583 	cd->cdi.mask = 0;
584 	cd->cdi.capacity = 1;
585 	sprintf(cd->cdi.name, "sr%d", minor);
586 
587 	sdev->sector_size = 2048;	/* A guess, just in case */
588 
589 	/* FIXME: need to handle a get_capabilities failure properly ?? */
590 	get_capabilities(cd);
591 	sr_vendor_init(cd);
592 
593 	disk->driverfs_dev = &sdev->sdev_gendev;
594 	set_capacity(disk, cd->capacity);
595 	disk->private_data = &cd->driver;
596 	disk->queue = sdev->request_queue;
597 	cd->cdi.disk = disk;
598 
599 	if (register_cdrom(&cd->cdi))
600 		goto fail_put;
601 
602 	dev_set_drvdata(dev, cd);
603 	disk->flags |= GENHD_FL_REMOVABLE;
604 	add_disk(disk);
605 
606 	sdev_printk(KERN_DEBUG, sdev,
607 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
608 	return 0;
609 
610 fail_put:
611 	put_disk(disk);
612 fail_free:
613 	kfree(cd);
614 fail:
615 	return error;
616 }
617 
618 
619 static void get_sectorsize(struct scsi_cd *cd)
620 {
621 	unsigned char cmd[10];
622 	unsigned char *buffer;
623 	int the_result, retries = 3;
624 	int sector_size;
625 	request_queue_t *queue;
626 
627 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
628 	if (!buffer)
629 		goto Enomem;
630 
631 	do {
632 		cmd[0] = READ_CAPACITY;
633 		memset((void *) &cmd[1], 0, 9);
634 		memset(buffer, 0, 8);
635 
636 		/* Do the command and wait.. */
637 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
638 					      buffer, 8, NULL, SR_TIMEOUT,
639 					      MAX_RETRIES);
640 
641 		retries--;
642 
643 	} while (the_result && retries);
644 
645 
646 	if (the_result) {
647 		cd->capacity = 0x1fffff;
648 		sector_size = 2048;	/* A guess, just in case */
649 	} else {
650 #if 0
651 		if (cdrom_get_last_written(&cd->cdi,
652 					   &cd->capacity))
653 #endif
654 			cd->capacity = 1 + ((buffer[0] << 24) |
655 						    (buffer[1] << 16) |
656 						    (buffer[2] << 8) |
657 						    buffer[3]);
658 		sector_size = (buffer[4] << 24) |
659 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
660 		switch (sector_size) {
661 			/*
662 			 * HP 4020i CD-Recorder reports 2340 byte sectors
663 			 * Philips CD-Writers report 2352 byte sectors
664 			 *
665 			 * Use 2k sectors for them..
666 			 */
667 		case 0:
668 		case 2340:
669 		case 2352:
670 			sector_size = 2048;
671 			/* fall through */
672 		case 2048:
673 			cd->capacity *= 4;
674 			/* fall through */
675 		case 512:
676 			break;
677 		default:
678 			printk("%s: unsupported sector size %d.\n",
679 			       cd->cdi.name, sector_size);
680 			cd->capacity = 0;
681 		}
682 
683 		cd->device->sector_size = sector_size;
684 
685 		/*
686 		 * Add this so that we have the ability to correctly gauge
687 		 * what the device is capable of.
688 		 */
689 		set_capacity(cd->disk, cd->capacity);
690 	}
691 
692 	queue = cd->device->request_queue;
693 	blk_queue_hardsect_size(queue, sector_size);
694 out:
695 	kfree(buffer);
696 	return;
697 
698 Enomem:
699 	cd->capacity = 0x1fffff;
700 	cd->device->sector_size = 2048;	/* A guess, just in case */
701 	goto out;
702 }
703 
704 static void get_capabilities(struct scsi_cd *cd)
705 {
706 	unsigned char *buffer;
707 	struct scsi_mode_data data;
708 	unsigned char cmd[MAX_COMMAND_SIZE];
709 	struct scsi_sense_hdr sshdr;
710 	unsigned int the_result;
711 	int retries, rc, n;
712 
713 	static const char *loadmech[] =
714 	{
715 		"caddy",
716 		"tray",
717 		"pop-up",
718 		"",
719 		"changer",
720 		"cartridge changer",
721 		"",
722 		""
723 	};
724 
725 
726 	/* allocate transfer buffer */
727 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
728 	if (!buffer) {
729 		printk(KERN_ERR "sr: out of memory.\n");
730 		return;
731 	}
732 
733 	/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
734 	 * conditions are gone, or a timeout happens
735 	 */
736 	retries = 0;
737 	do {
738 		memset((void *)cmd, 0, MAX_COMMAND_SIZE);
739 		cmd[0] = TEST_UNIT_READY;
740 
741 		the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL,
742 					       0, &sshdr, SR_TIMEOUT,
743 					       MAX_RETRIES);
744 
745 		retries++;
746 	} while (retries < 5 &&
747 		 (!scsi_status_is_good(the_result) ||
748 		  (scsi_sense_valid(&sshdr) &&
749 		   sshdr.sense_key == UNIT_ATTENTION)));
750 
751 	/* ask for mode page 0x2a */
752 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
753 			     SR_TIMEOUT, 3, &data, NULL);
754 
755 	if (!scsi_status_is_good(rc)) {
756 		/* failed, drive doesn't have capabilities mode page */
757 		cd->cdi.speed = 1;
758 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
759 				 CDC_DVD | CDC_DVD_RAM |
760 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
761 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
762 		kfree(buffer);
763 		printk("%s: scsi-1 drive\n", cd->cdi.name);
764 		return;
765 	}
766 
767 	n = data.header_length + data.block_descriptor_length;
768 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
769 	cd->readcd_known = 1;
770 	cd->readcd_cdda = buffer[n + 5] & 0x01;
771 	/* print some capability bits */
772 	printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
773 	       ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
774 	       cd->cdi.speed,
775 	       buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
776 	       buffer[n + 3] & 0x20 ? "dvd-ram " : "",
777 	       buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
778 	       buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
779 	       buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
780 	       loadmech[buffer[n + 6] >> 5]);
781 	if ((buffer[n + 6] >> 5) == 0)
782 		/* caddy drives can't close tray... */
783 		cd->cdi.mask |= CDC_CLOSE_TRAY;
784 	if ((buffer[n + 2] & 0x8) == 0)
785 		/* not a DVD drive */
786 		cd->cdi.mask |= CDC_DVD;
787 	if ((buffer[n + 3] & 0x20) == 0)
788 		/* can't write DVD-RAM media */
789 		cd->cdi.mask |= CDC_DVD_RAM;
790 	if ((buffer[n + 3] & 0x10) == 0)
791 		/* can't write DVD-R media */
792 		cd->cdi.mask |= CDC_DVD_R;
793 	if ((buffer[n + 3] & 0x2) == 0)
794 		/* can't write CD-RW media */
795 		cd->cdi.mask |= CDC_CD_RW;
796 	if ((buffer[n + 3] & 0x1) == 0)
797 		/* can't write CD-R media */
798 		cd->cdi.mask |= CDC_CD_R;
799 	if ((buffer[n + 6] & 0x8) == 0)
800 		/* can't eject */
801 		cd->cdi.mask |= CDC_OPEN_TRAY;
802 
803 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
804 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
805 		cd->cdi.capacity =
806 		    cdrom_number_of_slots(&cd->cdi);
807 	if (cd->cdi.capacity <= 1)
808 		/* not a changer */
809 		cd->cdi.mask |= CDC_SELECT_DISC;
810 	/*else    I don't think it can close its tray
811 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
812 
813 	/*
814 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
815 	 */
816 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
817 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
818 		cd->device->writeable = 1;
819 	}
820 
821 	kfree(buffer);
822 }
823 
824 /*
825  * sr_packet() is the entry point for the generic commands generated
826  * by the Uniform CD-ROM layer.
827  */
828 static int sr_packet(struct cdrom_device_info *cdi,
829 		struct packet_command *cgc)
830 {
831 	if (cgc->timeout <= 0)
832 		cgc->timeout = IOCTL_TIMEOUT;
833 
834 	sr_do_ioctl(cdi->handle, cgc);
835 
836 	return cgc->stat;
837 }
838 
839 /**
840  *	sr_kref_release - Called to free the scsi_cd structure
841  *	@kref: pointer to embedded kref
842  *
843  *	sr_ref_mutex must be held entering this routine.  Because it is
844  *	called on last put, you should always use the scsi_cd_get()
845  *	scsi_cd_put() helpers which manipulate the semaphore directly
846  *	and never do a direct kref_put().
847  **/
848 static void sr_kref_release(struct kref *kref)
849 {
850 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
851 	struct gendisk *disk = cd->disk;
852 
853 	spin_lock(&sr_index_lock);
854 	clear_bit(disk->first_minor, sr_index_bits);
855 	spin_unlock(&sr_index_lock);
856 
857 	unregister_cdrom(&cd->cdi);
858 
859 	disk->private_data = NULL;
860 
861 	put_disk(disk);
862 
863 	kfree(cd);
864 }
865 
866 static int sr_remove(struct device *dev)
867 {
868 	struct scsi_cd *cd = dev_get_drvdata(dev);
869 
870 	del_gendisk(cd->disk);
871 
872 	mutex_lock(&sr_ref_mutex);
873 	kref_put(&cd->kref, sr_kref_release);
874 	mutex_unlock(&sr_ref_mutex);
875 
876 	return 0;
877 }
878 
879 static int __init init_sr(void)
880 {
881 	int rc;
882 
883 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
884 	if (rc)
885 		return rc;
886 	return scsi_register_driver(&sr_template.gendrv);
887 }
888 
889 static void __exit exit_sr(void)
890 {
891 	scsi_unregister_driver(&sr_template.gendrv);
892 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
893 }
894 
895 module_init(init_sr);
896 module_exit(exit_sr);
897 MODULE_LICENSE("GPL");
898