xref: /openbmc/linux/drivers/scsi/sr.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 MAX_RETRIES	3
71 #define SR_TIMEOUT	(30 * HZ)
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 
79 static int sr_probe(struct device *);
80 static int sr_remove(struct device *);
81 static int sr_init_command(struct scsi_cmnd *);
82 
83 static struct scsi_driver sr_template = {
84 	.owner			= THIS_MODULE,
85 	.gendrv = {
86 		.name   	= "sr",
87 		.probe		= sr_probe,
88 		.remove		= sr_remove,
89 	},
90 	.init_command		= sr_init_command,
91 };
92 
93 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
94 static DEFINE_SPINLOCK(sr_index_lock);
95 
96 /* This semaphore is used to mediate the 0->1 reference get in the
97  * face of object destruction (i.e. we can't allow a get on an
98  * object after last put) */
99 static DEFINE_MUTEX(sr_ref_mutex);
100 
101 static int sr_open(struct cdrom_device_info *, int);
102 static void sr_release(struct cdrom_device_info *);
103 
104 static void get_sectorsize(struct scsi_cd *);
105 static void get_capabilities(struct scsi_cd *);
106 
107 static int sr_media_change(struct cdrom_device_info *, int);
108 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
109 
110 static struct cdrom_device_ops sr_dops = {
111 	.open			= sr_open,
112 	.release	 	= sr_release,
113 	.drive_status	 	= sr_drive_status,
114 	.media_changed		= sr_media_change,
115 	.tray_move		= sr_tray_move,
116 	.lock_door		= sr_lock_door,
117 	.select_speed		= sr_select_speed,
118 	.get_last_session	= sr_get_last_session,
119 	.get_mcn		= sr_get_mcn,
120 	.reset			= sr_reset,
121 	.audio_ioctl		= sr_audio_ioctl,
122 	.capability		= SR_CAPABILITIES,
123 	.generic_packet		= sr_packet,
124 };
125 
126 static void sr_kref_release(struct kref *kref);
127 
128 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
129 {
130 	return container_of(disk->private_data, struct scsi_cd, driver);
131 }
132 
133 /*
134  * The get and put routines for the struct scsi_cd.  Note this entity
135  * has a scsi_device pointer and owns a reference to this.
136  */
137 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
138 {
139 	struct scsi_cd *cd = NULL;
140 
141 	mutex_lock(&sr_ref_mutex);
142 	if (disk->private_data == NULL)
143 		goto out;
144 	cd = scsi_cd(disk);
145 	kref_get(&cd->kref);
146 	if (scsi_device_get(cd->device))
147 		goto out_put;
148 	goto out;
149 
150  out_put:
151 	kref_put(&cd->kref, sr_kref_release);
152 	cd = NULL;
153  out:
154 	mutex_unlock(&sr_ref_mutex);
155 	return cd;
156 }
157 
158 static void scsi_cd_put(struct scsi_cd *cd)
159 {
160 	struct scsi_device *sdev = cd->device;
161 
162 	mutex_lock(&sr_ref_mutex);
163 	kref_put(&cd->kref, sr_kref_release);
164 	scsi_device_put(sdev);
165 	mutex_unlock(&sr_ref_mutex);
166 }
167 
168 /*
169  * This function checks to see if the media has been changed in the
170  * CDROM drive.  It is possible that we have already sensed a change,
171  * or the drive may have sensed one and not yet reported it.  We must
172  * be ready for either case. This function always reports the current
173  * value of the changed bit.  If flag is 0, then the changed bit is reset.
174  * This function could be done as an ioctl, but we would need to have
175  * an inode for that to work, and we do not always have one.
176  */
177 
178 int sr_media_change(struct cdrom_device_info *cdi, int slot)
179 {
180 	struct scsi_cd *cd = cdi->handle;
181 	int retval;
182 
183 	if (CDSL_CURRENT != slot) {
184 		/* no changer support */
185 		return -EINVAL;
186 	}
187 
188 	retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES);
189 	if (retval) {
190 		/* Unable to test, unit probably not ready.  This usually
191 		 * means there is no disc in the drive.  Mark as changed,
192 		 * and we will figure it out later once the drive is
193 		 * available again.  */
194 		cd->device->changed = 1;
195 		return 1;	/* This will force a flush, if called from
196 				 * check_disk_change */
197 	};
198 
199 	retval = cd->device->changed;
200 	cd->device->changed = 0;
201 	/* If the disk changed, the capacity will now be different,
202 	 * so we force a re-read of this information */
203 	if (retval) {
204 		/* check multisession offset etc */
205 		sr_cd_check(cdi);
206 
207 		get_sectorsize(cd);
208 	}
209 	return retval;
210 }
211 
212 /*
213  * rw_intr is the interrupt routine for the device driver.
214  *
215  * It will be notified on the end of a SCSI read / write, and will take on
216  * of several actions based on success or failure.
217  */
218 static void rw_intr(struct scsi_cmnd * SCpnt)
219 {
220 	int result = SCpnt->result;
221 	int this_count = SCpnt->request_bufflen;
222 	int good_bytes = (result == 0 ? this_count : 0);
223 	int block_sectors = 0;
224 	long error_sector;
225 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
226 
227 #ifdef DEBUG
228 	printk("sr.c done: %x\n", result);
229 #endif
230 
231 	/*
232 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
233 	 * success.  Since this is a relatively rare error condition, no
234 	 * care is taken to avoid unnecessary additional work such as
235 	 * memcpy's that could be avoided.
236 	 */
237 	if (driver_byte(result) != 0 &&		/* An error occurred */
238 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
239 		switch (SCpnt->sense_buffer[2]) {
240 		case MEDIUM_ERROR:
241 		case VOLUME_OVERFLOW:
242 		case ILLEGAL_REQUEST:
243 			if (!(SCpnt->sense_buffer[0] & 0x90))
244 				break;
245 			error_sector = (SCpnt->sense_buffer[3] << 24) |
246 				(SCpnt->sense_buffer[4] << 16) |
247 				(SCpnt->sense_buffer[5] << 8) |
248 				SCpnt->sense_buffer[6];
249 			if (SCpnt->request->bio != NULL)
250 				block_sectors =
251 					bio_sectors(SCpnt->request->bio);
252 			if (block_sectors < 4)
253 				block_sectors = 4;
254 			if (cd->device->sector_size == 2048)
255 				error_sector <<= 2;
256 			error_sector &= ~(block_sectors - 1);
257 			good_bytes = (error_sector - SCpnt->request->sector) << 9;
258 			if (good_bytes < 0 || good_bytes >= this_count)
259 				good_bytes = 0;
260 			/*
261 			 * The SCSI specification allows for the value
262 			 * returned by READ CAPACITY to be up to 75 2K
263 			 * sectors past the last readable block.
264 			 * Therefore, if we hit a medium error within the
265 			 * last 75 2K sectors, we decrease the saved size
266 			 * value.
267 			 */
268 			if (error_sector < get_capacity(cd->disk) &&
269 			    cd->capacity - error_sector < 4 * 75)
270 				set_capacity(cd->disk, error_sector);
271 			break;
272 
273 		case RECOVERED_ERROR:
274 
275 			/*
276 			 * An error occured, but it recovered.  Inform the
277 			 * user, but make sure that it's not treated as a
278 			 * hard error.
279 			 */
280 			scsi_print_sense("sr", SCpnt);
281 			SCpnt->result = 0;
282 			SCpnt->sense_buffer[0] = 0x0;
283 			good_bytes = this_count;
284 			break;
285 
286 		default:
287 			break;
288 		}
289 	}
290 
291 	/*
292 	 * This calls the generic completion function, now that we know
293 	 * how many actual sectors finished, and how many sectors we need
294 	 * to say have failed.
295 	 */
296 	scsi_io_completion(SCpnt, good_bytes);
297 }
298 
299 static int sr_init_command(struct scsi_cmnd * SCpnt)
300 {
301 	int block=0, this_count, s_size, timeout = SR_TIMEOUT;
302 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
303 
304 	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
305 				cd->disk->disk_name, block));
306 
307 	if (!cd->device || !scsi_device_online(cd->device)) {
308 		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
309 					SCpnt->request->nr_sectors));
310 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
311 		return 0;
312 	}
313 
314 	if (cd->device->changed) {
315 		/*
316 		 * quietly refuse to do anything to a changed disc until the
317 		 * changed bit has been reset
318 		 */
319 		return 0;
320 	}
321 
322 	/*
323 	 * we do lazy blocksize switching (when reading XA sectors,
324 	 * see CDROMREADMODE2 ioctl)
325 	 */
326 	s_size = cd->device->sector_size;
327 	if (s_size > 2048) {
328 		if (!in_interrupt())
329 			sr_set_blocklength(cd, 2048);
330 		else
331 			printk("sr: can't switch blocksize: in interrupt\n");
332 	}
333 
334 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
335 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
336 		return 0;
337 	}
338 
339 	if (rq_data_dir(SCpnt->request) == WRITE) {
340 		if (!cd->device->writeable)
341 			return 0;
342 		SCpnt->cmnd[0] = WRITE_10;
343 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
344  	 	cd->cdi.media_written = 1;
345 	} else if (rq_data_dir(SCpnt->request) == READ) {
346 		SCpnt->cmnd[0] = READ_10;
347 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
348 	} else {
349 		blk_dump_rq_flags(SCpnt->request, "Unknown sr command");
350 		return 0;
351 	}
352 
353 	{
354 		struct scatterlist *sg = SCpnt->request_buffer;
355 		int i, size = 0;
356 		for (i = 0; i < SCpnt->use_sg; i++)
357 			size += sg[i].length;
358 
359 		if (size != SCpnt->request_bufflen && SCpnt->use_sg) {
360 			scmd_printk(KERN_ERR, SCpnt,
361 				"mismatch count %d, bytes %d\n",
362 				size, SCpnt->request_bufflen);
363 			if (SCpnt->request_bufflen > size)
364 				SCpnt->request_bufflen = size;
365 		}
366 	}
367 
368 	/*
369 	 * request doesn't start on hw block boundary, add scatter pads
370 	 */
371 	if (((unsigned int)SCpnt->request->sector % (s_size >> 9)) ||
372 	    (SCpnt->request_bufflen % s_size)) {
373 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
374 		return 0;
375 	}
376 
377 	this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9);
378 
379 
380 	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
381 				cd->cdi.name,
382 				(rq_data_dir(SCpnt->request) == WRITE) ?
383 					"writing" : "reading",
384 				this_count, SCpnt->request->nr_sectors));
385 
386 	SCpnt->cmnd[1] = 0;
387 	block = (unsigned int)SCpnt->request->sector / (s_size >> 9);
388 
389 	if (this_count > 0xffff) {
390 		this_count = 0xffff;
391 		SCpnt->request_bufflen = this_count * s_size;
392 	}
393 
394 	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
395 	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
396 	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
397 	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
398 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
399 	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
400 	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
401 
402 	/*
403 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
404 	 * host adapter, it's safe to assume that we can at least transfer
405 	 * this many bytes between each connect / disconnect.
406 	 */
407 	SCpnt->transfersize = cd->device->sector_size;
408 	SCpnt->underflow = this_count << 9;
409 	SCpnt->allowed = MAX_RETRIES;
410 	SCpnt->timeout_per_command = timeout;
411 
412 	/*
413 	 * This is the completion routine we use.  This is matched in terms
414 	 * of capability to this function.
415 	 */
416 	SCpnt->done = rw_intr;
417 
418 	/*
419 	 * This indicates that the command is ready from our end to be
420 	 * queued.
421 	 */
422 	return 1;
423 }
424 
425 static int sr_block_open(struct inode *inode, struct file *file)
426 {
427 	struct gendisk *disk = inode->i_bdev->bd_disk;
428 	struct scsi_cd *cd;
429 	int ret = 0;
430 
431 	if(!(cd = scsi_cd_get(disk)))
432 		return -ENXIO;
433 
434 	if((ret = cdrom_open(&cd->cdi, inode, file)) != 0)
435 		scsi_cd_put(cd);
436 
437 	return ret;
438 }
439 
440 static int sr_block_release(struct inode *inode, struct file *file)
441 {
442 	int ret;
443 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
444 	ret = cdrom_release(&cd->cdi, file);
445 	if(ret)
446 		return ret;
447 
448 	scsi_cd_put(cd);
449 
450 	return 0;
451 }
452 
453 static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
454 			  unsigned long arg)
455 {
456 	struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
457 	struct scsi_device *sdev = cd->device;
458 	void __user *argp = (void __user *)arg;
459 	int ret;
460 
461 	/*
462 	 * Send SCSI addressing ioctls directly to mid level, send other
463 	 * ioctls to cdrom/block level.
464 	 */
465 	switch (cmd) {
466 	case SCSI_IOCTL_GET_IDLUN:
467 	case SCSI_IOCTL_GET_BUS_NUMBER:
468 		return scsi_ioctl(sdev, cmd, argp);
469 	}
470 
471 	ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
472 	if (ret != -ENOSYS)
473 		return ret;
474 
475 	/*
476 	 * ENODEV means that we didn't recognise the ioctl, or that we
477 	 * cannot execute it in the current device state.  In either
478 	 * case fall through to scsi_ioctl, which will return ENDOEV again
479 	 * if it doesn't recognise the ioctl
480 	 */
481 	ret = scsi_nonblockable_ioctl(sdev, cmd, argp, NULL);
482 	if (ret != -ENODEV)
483 		return ret;
484 	return scsi_ioctl(sdev, cmd, argp);
485 }
486 
487 static int sr_block_media_changed(struct gendisk *disk)
488 {
489 	struct scsi_cd *cd = scsi_cd(disk);
490 	return cdrom_media_changed(&cd->cdi);
491 }
492 
493 static struct block_device_operations sr_bdops =
494 {
495 	.owner		= THIS_MODULE,
496 	.open		= sr_block_open,
497 	.release	= sr_block_release,
498 	.ioctl		= sr_block_ioctl,
499 	.media_changed	= sr_block_media_changed,
500 	/*
501 	 * No compat_ioctl for now because sr_block_ioctl never
502 	 * seems to pass arbitary ioctls down to host drivers.
503 	 */
504 };
505 
506 static int sr_open(struct cdrom_device_info *cdi, int purpose)
507 {
508 	struct scsi_cd *cd = cdi->handle;
509 	struct scsi_device *sdev = cd->device;
510 	int retval;
511 
512 	/*
513 	 * If the device is in error recovery, wait until it is done.
514 	 * If the device is offline, then disallow any access to it.
515 	 */
516 	retval = -ENXIO;
517 	if (!scsi_block_when_processing_errors(sdev))
518 		goto error_out;
519 
520 	return 0;
521 
522 error_out:
523 	return retval;
524 }
525 
526 static void sr_release(struct cdrom_device_info *cdi)
527 {
528 	struct scsi_cd *cd = cdi->handle;
529 
530 	if (cd->device->sector_size > 2048)
531 		sr_set_blocklength(cd, 2048);
532 
533 }
534 
535 static int sr_probe(struct device *dev)
536 {
537 	struct scsi_device *sdev = to_scsi_device(dev);
538 	struct gendisk *disk;
539 	struct scsi_cd *cd;
540 	int minor, error;
541 
542 	error = -ENODEV;
543 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
544 		goto fail;
545 
546 	error = -ENOMEM;
547 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
548 	if (!cd)
549 		goto fail;
550 
551 	kref_init(&cd->kref);
552 
553 	disk = alloc_disk(1);
554 	if (!disk)
555 		goto fail_free;
556 
557 	spin_lock(&sr_index_lock);
558 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
559 	if (minor == SR_DISKS) {
560 		spin_unlock(&sr_index_lock);
561 		error = -EBUSY;
562 		goto fail_put;
563 	}
564 	__set_bit(minor, sr_index_bits);
565 	spin_unlock(&sr_index_lock);
566 
567 	disk->major = SCSI_CDROM_MAJOR;
568 	disk->first_minor = minor;
569 	sprintf(disk->disk_name, "sr%d", minor);
570 	disk->fops = &sr_bdops;
571 	disk->flags = GENHD_FL_CD;
572 
573 	cd->device = sdev;
574 	cd->disk = disk;
575 	cd->driver = &sr_template;
576 	cd->disk = disk;
577 	cd->capacity = 0x1fffff;
578 	cd->device->changed = 1;	/* force recheck CD type */
579 	cd->use = 1;
580 	cd->readcd_known = 0;
581 	cd->readcd_cdda = 0;
582 
583 	cd->cdi.ops = &sr_dops;
584 	cd->cdi.handle = cd;
585 	cd->cdi.mask = 0;
586 	cd->cdi.capacity = 1;
587 	sprintf(cd->cdi.name, "sr%d", minor);
588 
589 	sdev->sector_size = 2048;	/* A guess, just in case */
590 
591 	/* FIXME: need to handle a get_capabilities failure properly ?? */
592 	get_capabilities(cd);
593 	sr_vendor_init(cd);
594 
595 	disk->driverfs_dev = &sdev->sdev_gendev;
596 	set_capacity(disk, cd->capacity);
597 	disk->private_data = &cd->driver;
598 	disk->queue = sdev->request_queue;
599 	cd->cdi.disk = disk;
600 
601 	if (register_cdrom(&cd->cdi))
602 		goto fail_put;
603 
604 	dev_set_drvdata(dev, cd);
605 	disk->flags |= GENHD_FL_REMOVABLE;
606 	add_disk(disk);
607 
608 	sdev_printk(KERN_DEBUG, sdev,
609 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
610 	return 0;
611 
612 fail_put:
613 	put_disk(disk);
614 fail_free:
615 	kfree(cd);
616 fail:
617 	return error;
618 }
619 
620 
621 static void get_sectorsize(struct scsi_cd *cd)
622 {
623 	unsigned char cmd[10];
624 	unsigned char *buffer;
625 	int the_result, retries = 3;
626 	int sector_size;
627 	request_queue_t *queue;
628 
629 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
630 	if (!buffer)
631 		goto Enomem;
632 
633 	do {
634 		cmd[0] = READ_CAPACITY;
635 		memset((void *) &cmd[1], 0, 9);
636 		memset(buffer, 0, 8);
637 
638 		/* Do the command and wait.. */
639 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
640 					      buffer, 8, NULL, SR_TIMEOUT,
641 					      MAX_RETRIES);
642 
643 		retries--;
644 
645 	} while (the_result && retries);
646 
647 
648 	if (the_result) {
649 		cd->capacity = 0x1fffff;
650 		sector_size = 2048;	/* A guess, just in case */
651 	} else {
652 #if 0
653 		if (cdrom_get_last_written(&cd->cdi,
654 					   &cd->capacity))
655 #endif
656 			cd->capacity = 1 + ((buffer[0] << 24) |
657 						    (buffer[1] << 16) |
658 						    (buffer[2] << 8) |
659 						    buffer[3]);
660 		sector_size = (buffer[4] << 24) |
661 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
662 		switch (sector_size) {
663 			/*
664 			 * HP 4020i CD-Recorder reports 2340 byte sectors
665 			 * Philips CD-Writers report 2352 byte sectors
666 			 *
667 			 * Use 2k sectors for them..
668 			 */
669 		case 0:
670 		case 2340:
671 		case 2352:
672 			sector_size = 2048;
673 			/* fall through */
674 		case 2048:
675 			cd->capacity *= 4;
676 			/* fall through */
677 		case 512:
678 			break;
679 		default:
680 			printk("%s: unsupported sector size %d.\n",
681 			       cd->cdi.name, sector_size);
682 			cd->capacity = 0;
683 		}
684 
685 		cd->device->sector_size = sector_size;
686 
687 		/*
688 		 * Add this so that we have the ability to correctly gauge
689 		 * what the device is capable of.
690 		 */
691 		set_capacity(cd->disk, cd->capacity);
692 	}
693 
694 	queue = cd->device->request_queue;
695 	blk_queue_hardsect_size(queue, sector_size);
696 out:
697 	kfree(buffer);
698 	return;
699 
700 Enomem:
701 	cd->capacity = 0x1fffff;
702 	cd->device->sector_size = 2048;	/* A guess, just in case */
703 	goto out;
704 }
705 
706 static void get_capabilities(struct scsi_cd *cd)
707 {
708 	unsigned char *buffer;
709 	struct scsi_mode_data data;
710 	unsigned char cmd[MAX_COMMAND_SIZE];
711 	struct scsi_sense_hdr sshdr;
712 	unsigned int the_result;
713 	int retries, rc, n;
714 
715 	static const char *loadmech[] =
716 	{
717 		"caddy",
718 		"tray",
719 		"pop-up",
720 		"",
721 		"changer",
722 		"cartridge changer",
723 		"",
724 		""
725 	};
726 
727 
728 	/* allocate transfer buffer */
729 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
730 	if (!buffer) {
731 		printk(KERN_ERR "sr: out of memory.\n");
732 		return;
733 	}
734 
735 	/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
736 	 * conditions are gone, or a timeout happens
737 	 */
738 	retries = 0;
739 	do {
740 		memset((void *)cmd, 0, MAX_COMMAND_SIZE);
741 		cmd[0] = TEST_UNIT_READY;
742 
743 		the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL,
744 					       0, &sshdr, SR_TIMEOUT,
745 					       MAX_RETRIES);
746 
747 		retries++;
748 	} while (retries < 5 &&
749 		 (!scsi_status_is_good(the_result) ||
750 		  (scsi_sense_valid(&sshdr) &&
751 		   sshdr.sense_key == UNIT_ATTENTION)));
752 
753 	/* ask for mode page 0x2a */
754 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
755 			     SR_TIMEOUT, 3, &data, NULL);
756 
757 	if (!scsi_status_is_good(rc)) {
758 		/* failed, drive doesn't have capabilities mode page */
759 		cd->cdi.speed = 1;
760 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
761 				 CDC_DVD | CDC_DVD_RAM |
762 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
763 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
764 		kfree(buffer);
765 		printk("%s: scsi-1 drive\n", cd->cdi.name);
766 		return;
767 	}
768 
769 	n = data.header_length + data.block_descriptor_length;
770 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
771 	cd->readcd_known = 1;
772 	cd->readcd_cdda = buffer[n + 5] & 0x01;
773 	/* print some capability bits */
774 	printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
775 	       ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
776 	       cd->cdi.speed,
777 	       buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
778 	       buffer[n + 3] & 0x20 ? "dvd-ram " : "",
779 	       buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
780 	       buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
781 	       buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
782 	       loadmech[buffer[n + 6] >> 5]);
783 	if ((buffer[n + 6] >> 5) == 0)
784 		/* caddy drives can't close tray... */
785 		cd->cdi.mask |= CDC_CLOSE_TRAY;
786 	if ((buffer[n + 2] & 0x8) == 0)
787 		/* not a DVD drive */
788 		cd->cdi.mask |= CDC_DVD;
789 	if ((buffer[n + 3] & 0x20) == 0)
790 		/* can't write DVD-RAM media */
791 		cd->cdi.mask |= CDC_DVD_RAM;
792 	if ((buffer[n + 3] & 0x10) == 0)
793 		/* can't write DVD-R media */
794 		cd->cdi.mask |= CDC_DVD_R;
795 	if ((buffer[n + 3] & 0x2) == 0)
796 		/* can't write CD-RW media */
797 		cd->cdi.mask |= CDC_CD_RW;
798 	if ((buffer[n + 3] & 0x1) == 0)
799 		/* can't write CD-R media */
800 		cd->cdi.mask |= CDC_CD_R;
801 	if ((buffer[n + 6] & 0x8) == 0)
802 		/* can't eject */
803 		cd->cdi.mask |= CDC_OPEN_TRAY;
804 
805 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
806 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
807 		cd->cdi.capacity =
808 		    cdrom_number_of_slots(&cd->cdi);
809 	if (cd->cdi.capacity <= 1)
810 		/* not a changer */
811 		cd->cdi.mask |= CDC_SELECT_DISC;
812 	/*else    I don't think it can close its tray
813 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
814 
815 	/*
816 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
817 	 */
818 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
819 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
820 		cd->device->writeable = 1;
821 	}
822 
823 	kfree(buffer);
824 }
825 
826 /*
827  * sr_packet() is the entry point for the generic commands generated
828  * by the Uniform CD-ROM layer.
829  */
830 static int sr_packet(struct cdrom_device_info *cdi,
831 		struct packet_command *cgc)
832 {
833 	if (cgc->timeout <= 0)
834 		cgc->timeout = IOCTL_TIMEOUT;
835 
836 	sr_do_ioctl(cdi->handle, cgc);
837 
838 	return cgc->stat;
839 }
840 
841 /**
842  *	sr_kref_release - Called to free the scsi_cd structure
843  *	@kref: pointer to embedded kref
844  *
845  *	sr_ref_mutex must be held entering this routine.  Because it is
846  *	called on last put, you should always use the scsi_cd_get()
847  *	scsi_cd_put() helpers which manipulate the semaphore directly
848  *	and never do a direct kref_put().
849  **/
850 static void sr_kref_release(struct kref *kref)
851 {
852 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
853 	struct gendisk *disk = cd->disk;
854 
855 	spin_lock(&sr_index_lock);
856 	clear_bit(disk->first_minor, sr_index_bits);
857 	spin_unlock(&sr_index_lock);
858 
859 	unregister_cdrom(&cd->cdi);
860 
861 	disk->private_data = NULL;
862 
863 	put_disk(disk);
864 
865 	kfree(cd);
866 }
867 
868 static int sr_remove(struct device *dev)
869 {
870 	struct scsi_cd *cd = dev_get_drvdata(dev);
871 
872 	del_gendisk(cd->disk);
873 
874 	mutex_lock(&sr_ref_mutex);
875 	kref_put(&cd->kref, sr_kref_release);
876 	mutex_unlock(&sr_ref_mutex);
877 
878 	return 0;
879 }
880 
881 static int __init init_sr(void)
882 {
883 	int rc;
884 
885 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
886 	if (rc)
887 		return rc;
888 	return scsi_register_driver(&sr_template.gendrv);
889 }
890 
891 static void __exit exit_sr(void)
892 {
893 	scsi_unregister_driver(&sr_template.gendrv);
894 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
895 }
896 
897 module_init(init_sr);
898 module_exit(exit_sr);
899 MODULE_LICENSE("GPL");
900