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 <asm/uaccess.h>
  49
  50#include <scsi/scsi.h>
  51#include <scsi/scsi_dbg.h>
  52#include <scsi/scsi_device.h>
  53#include <scsi/scsi_driver.h>
  54#include <scsi/scsi_cmnd.h>
  55#include <scsi/scsi_eh.h>
  56#include <scsi/scsi_host.h>
  57#include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
  58
  59#include "scsi_logging.h"
  60#include "sr.h"
  61
  62
  63MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
  64MODULE_LICENSE("GPL");
  65MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
  66MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
  67MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
  68
  69#define SR_DISKS	256
  70
  71#define SR_CAPABILITIES \
  72	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
  73	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
  74	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
  75	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
  76	 CDC_MRW|CDC_MRW_W|CDC_RAM)
  77
  78static DEFINE_MUTEX(sr_mutex);
  79static int sr_probe(struct device *);
  80static int sr_remove(struct device *);
  81static int sr_done(struct scsi_cmnd *);
  82
  83static struct scsi_driver sr_template = {
  84	.owner			= THIS_MODULE,
  85	.gendrv = {
  86		.name   	= "sr",
  87		.probe		= sr_probe,
  88		.remove		= sr_remove,
  89	},
  90	.done			= sr_done,
  91};
  92
  93static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
  94static 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) */
  99static DEFINE_MUTEX(sr_ref_mutex);
 100
 101static int sr_open(struct cdrom_device_info *, int);
 102static void sr_release(struct cdrom_device_info *);
 103
 104static void get_sectorsize(struct scsi_cd *);
 105static void get_capabilities(struct scsi_cd *);
 106
 107static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 108				    unsigned int clearing, int slot);
 109static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 110
 111static struct cdrom_device_ops sr_dops = {
 112	.open			= sr_open,
 113	.release	 	= sr_release,
 114	.drive_status	 	= sr_drive_status,
 115	.check_events		= sr_check_events,
 116	.tray_move		= sr_tray_move,
 117	.lock_door		= sr_lock_door,
 118	.select_speed		= sr_select_speed,
 119	.get_last_session	= sr_get_last_session,
 120	.get_mcn		= sr_get_mcn,
 121	.reset			= sr_reset,
 122	.audio_ioctl		= sr_audio_ioctl,
 123	.capability		= SR_CAPABILITIES,
 124	.generic_packet		= sr_packet,
 125};
 126
 127static void sr_kref_release(struct kref *kref);
 128
 129static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
 130{
 131	return container_of(disk->private_data, struct scsi_cd, driver);
 132}
 133
 134/*
 135 * The get and put routines for the struct scsi_cd.  Note this entity
 136 * has a scsi_device pointer and owns a reference to this.
 137 */
 138static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 139{
 140	struct scsi_cd *cd = NULL;
 141
 142	mutex_lock(&sr_ref_mutex);
 143	if (disk->private_data == NULL)
 144		goto out;
 145	cd = scsi_cd(disk);
 146	kref_get(&cd->kref);
 147	if (scsi_device_get(cd->device))
 148		goto out_put;
 149	goto out;
 150
 151 out_put:
 152	kref_put(&cd->kref, sr_kref_release);
 153	cd = NULL;
 154 out:
 155	mutex_unlock(&sr_ref_mutex);
 156	return cd;
 157}
 158
 159static void scsi_cd_put(struct scsi_cd *cd)
 160{
 161	struct scsi_device *sdev = cd->device;
 162
 163	mutex_lock(&sr_ref_mutex);
 164	kref_put(&cd->kref, sr_kref_release);
 165	scsi_device_put(sdev);
 166	mutex_unlock(&sr_ref_mutex);
 167}
 168
 169static unsigned int sr_get_events(struct scsi_device *sdev)
 170{
 171	u8 buf[8];
 172	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
 173		     1,			/* polled */
 174		     0, 0,		/* reserved */
 175		     1 << 4,		/* notification class: media */
 176		     0, 0,		/* reserved */
 177		     0, sizeof(buf),	/* allocation length */
 178		     0,			/* control */
 179	};
 180	struct event_header *eh = (void *)buf;
 181	struct media_event_desc *med = (void *)(buf + 4);
 182	struct scsi_sense_hdr sshdr;
 183	int result;
 184
 185	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
 186				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
 187	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
 188		return DISK_EVENT_MEDIA_CHANGE;
 189
 190	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
 191		return 0;
 192
 193	if (eh->nea || eh->notification_class != 0x4)
 194		return 0;
 195
 196	if (med->media_event_code == 1)
 197		return DISK_EVENT_EJECT_REQUEST;
 198	else if (med->media_event_code == 2)
 199		return DISK_EVENT_MEDIA_CHANGE;
 200	return 0;
 201}
 202
 203/*
 204 * This function checks to see if the media has been changed or eject
 205 * button has been pressed.  It is possible that we have already
 206 * sensed a change, or the drive may have sensed one and not yet
 207 * reported it.  The past events are accumulated in sdev->changed and
 208 * returned together with the current state.
 209 */
 210static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 211				    unsigned int clearing, int slot)
 212{
 213	struct scsi_cd *cd = cdi->handle;
 214	bool last_present;
 215	struct scsi_sense_hdr sshdr;
 216	unsigned int events;
 217	int ret;
 218
 219	/* no changer support */
 220	if (CDSL_CURRENT != slot)
 221		return 0;
 222
 223	events = sr_get_events(cd->device);
 224	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
 225
 226	/*
 227	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
 228	 * for several times in a row.  We rely on TUR only for this likely
 229	 * broken device, to prevent generating incorrect media changed
 230	 * events for every open().
 231	 */
 232	if (cd->ignore_get_event) {
 233		events &= ~DISK_EVENT_MEDIA_CHANGE;
 234		goto do_tur;
 235	}
 236
 237	/*
 238	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
 239	 * is being cleared.  Note that there are devices which hang
 240	 * if asked to execute TUR repeatedly.
 241	 */
 242	if (cd->device->changed) {
 243		events |= DISK_EVENT_MEDIA_CHANGE;
 244		cd->device->changed = 0;
 245		cd->tur_changed = true;
 246	}
 247
 248	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
 249		return events;
 250do_tur:
 251	/* let's see whether the media is there with TUR */
 252	last_present = cd->media_present;
 253	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 254
 255	/*
 256	 * Media is considered to be present if TUR succeeds or fails with
 257	 * sense data indicating something other than media-not-present
 258	 * (ASC 0x3a).
 259	 */
 260	cd->media_present = scsi_status_is_good(ret) ||
 261		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 262
 263	if (last_present != cd->media_present)
 264		cd->device->changed = 1;
 265
 266	if (cd->device->changed) {
 267		events |= DISK_EVENT_MEDIA_CHANGE;
 268		cd->device->changed = 0;
 269		cd->tur_changed = true;
 270	}
 271
 272	if (cd->ignore_get_event)
 273		return events;
 274
 275	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
 276	if (!cd->tur_changed) {
 277		if (cd->get_event_changed) {
 278			if (cd->tur_mismatch++ > 8) {
 279				sdev_printk(KERN_WARNING, cd->device,
 280					    "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
 281				cd->ignore_get_event = true;
 282			}
 283		} else {
 284			cd->tur_mismatch = 0;
 285		}
 286	}
 287	cd->tur_changed = false;
 288	cd->get_event_changed = false;
 289
 290	return events;
 291}
 292
 293/*
 294 * sr_done is the interrupt routine for the device driver.
 295 *
 296 * It will be notified on the end of a SCSI read / write, and will take one
 297 * of several actions based on success or failure.
 298 */
 299static int sr_done(struct scsi_cmnd *SCpnt)
 300{
 301	int result = SCpnt->result;
 302	int this_count = scsi_bufflen(SCpnt);
 303	int good_bytes = (result == 0 ? this_count : 0);
 304	int block_sectors = 0;
 305	long error_sector;
 306	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
 307
 308#ifdef DEBUG
 309	printk("sr.c done: %x\n", result);
 310#endif
 311
 312	/*
 313	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
 314	 * success.  Since this is a relatively rare error condition, no
 315	 * care is taken to avoid unnecessary additional work such as
 316	 * memcpy's that could be avoided.
 317	 */
 318	if (driver_byte(result) != 0 &&		/* An error occurred */
 319	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
 320		switch (SCpnt->sense_buffer[2]) {
 321		case MEDIUM_ERROR:
 322		case VOLUME_OVERFLOW:
 323		case ILLEGAL_REQUEST:
 324			if (!(SCpnt->sense_buffer[0] & 0x90))
 325				break;
 326			error_sector = (SCpnt->sense_buffer[3] << 24) |
 327				(SCpnt->sense_buffer[4] << 16) |
 328				(SCpnt->sense_buffer[5] << 8) |
 329				SCpnt->sense_buffer[6];
 330			if (SCpnt->request->bio != NULL)
 331				block_sectors =
 332					bio_sectors(SCpnt->request->bio);
 333			if (block_sectors < 4)
 334				block_sectors = 4;
 335			if (cd->device->sector_size == 2048)
 336				error_sector <<= 2;
 337			error_sector &= ~(block_sectors - 1);
 338			good_bytes = (error_sector -
 339				      blk_rq_pos(SCpnt->request)) << 9;
 340			if (good_bytes < 0 || good_bytes >= this_count)
 341				good_bytes = 0;
 342			/*
 343			 * The SCSI specification allows for the value
 344			 * returned by READ CAPACITY to be up to 75 2K
 345			 * sectors past the last readable block.
 346			 * Therefore, if we hit a medium error within the
 347			 * last 75 2K sectors, we decrease the saved size
 348			 * value.
 349			 */
 350			if (error_sector < get_capacity(cd->disk) &&
 351			    cd->capacity - error_sector < 4 * 75)
 352				set_capacity(cd->disk, error_sector);
 353			break;
 354
 355		case RECOVERED_ERROR:
 356			good_bytes = this_count;
 357			break;
 358
 359		default:
 360			break;
 361		}
 362	}
 363
 364	return good_bytes;
 365}
 366
 367static int sr_prep_fn(struct request_queue *q, struct request *rq)
 368{
 369	int block = 0, this_count, s_size;
 370	struct scsi_cd *cd;
 371	struct scsi_cmnd *SCpnt;
 372	struct scsi_device *sdp = q->queuedata;
 373	int ret;
 374
 375	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
 376		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
 377		goto out;
 378	} else if (rq->cmd_type != REQ_TYPE_FS) {
 379		ret = BLKPREP_KILL;
 380		goto out;
 381	}
 382	ret = scsi_setup_fs_cmnd(sdp, rq);
 383	if (ret != BLKPREP_OK)
 384		goto out;
 385	SCpnt = rq->special;
 386	cd = scsi_cd(rq->rq_disk);
 387
 388	/* from here on until we're complete, any goto out
 389	 * is used for a killable error condition */
 390	ret = BLKPREP_KILL;
 391
 392	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
 393				cd->disk->disk_name, block));
 394
 395	if (!cd->device || !scsi_device_online(cd->device)) {
 396		SCSI_LOG_HLQUEUE(2, printk("Finishing %u sectors\n",
 397					   blk_rq_sectors(rq)));
 398		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
 399		goto out;
 400	}
 401
 402	if (cd->device->changed) {
 403		/*
 404		 * quietly refuse to do anything to a changed disc until the
 405		 * changed bit has been reset
 406		 */
 407		goto out;
 408	}
 409
 410	/*
 411	 * we do lazy blocksize switching (when reading XA sectors,
 412	 * see CDROMREADMODE2 ioctl) 
 413	 */
 414	s_size = cd->device->sector_size;
 415	if (s_size > 2048) {
 416		if (!in_interrupt())
 417			sr_set_blocklength(cd, 2048);
 418		else
 419			printk("sr: can't switch blocksize: in interrupt\n");
 420	}
 421
 422	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
 423		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
 424		goto out;
 425	}
 426
 427	if (rq_data_dir(rq) == WRITE) {
 428		if (!cd->device->writeable)
 429			goto out;
 430		SCpnt->cmnd[0] = WRITE_10;
 431		SCpnt->sc_data_direction = DMA_TO_DEVICE;
 432 	 	cd->cdi.media_written = 1;
 433	} else if (rq_data_dir(rq) == READ) {
 434		SCpnt->cmnd[0] = READ_10;
 435		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
 436	} else {
 437		blk_dump_rq_flags(rq, "Unknown sr command");
 438		goto out;
 439	}
 440
 441	{
 442		struct scatterlist *sg;
 443		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
 444
 445		scsi_for_each_sg(SCpnt, sg, sg_count, i)
 446			size += sg->length;
 447
 448		if (size != scsi_bufflen(SCpnt)) {
 449			scmd_printk(KERN_ERR, SCpnt,
 450				"mismatch count %d, bytes %d\n",
 451				size, scsi_bufflen(SCpnt));
 452			if (scsi_bufflen(SCpnt) > size)
 453				SCpnt->sdb.length = size;
 454		}
 455	}
 456
 457	/*
 458	 * request doesn't start on hw block boundary, add scatter pads
 459	 */
 460	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
 461	    (scsi_bufflen(SCpnt) % s_size)) {
 462		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
 463		goto out;
 464	}
 465
 466	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
 467
 468
 469	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%u 512 byte blocks.\n",
 470				cd->cdi.name,
 471				(rq_data_dir(rq) == WRITE) ?
 472					"writing" : "reading",
 473				this_count, blk_rq_sectors(rq)));
 474
 475	SCpnt->cmnd[1] = 0;
 476	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
 477
 478	if (this_count > 0xffff) {
 479		this_count = 0xffff;
 480		SCpnt->sdb.length = this_count * s_size;
 481	}
 482
 483	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
 484	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
 485	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
 486	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
 487	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
 488	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
 489	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
 490
 491	/*
 492	 * We shouldn't disconnect in the middle of a sector, so with a dumb
 493	 * host adapter, it's safe to assume that we can at least transfer
 494	 * this many bytes between each connect / disconnect.
 495	 */
 496	SCpnt->transfersize = cd->device->sector_size;
 497	SCpnt->underflow = this_count << 9;
 498	SCpnt->allowed = MAX_RETRIES;
 499
 500	/*
 501	 * This indicates that the command is ready from our end to be
 502	 * queued.
 503	 */
 504	ret = BLKPREP_OK;
 505 out:
 506	return scsi_prep_return(q, rq, ret);
 507}
 508
 509static int sr_block_open(struct block_device *bdev, fmode_t mode)
 510{
 511	struct scsi_cd *cd;
 512	int ret = -ENXIO;
 513
 514	mutex_lock(&sr_mutex);
 515	cd = scsi_cd_get(bdev->bd_disk);
 516	if (cd) {
 517		ret = cdrom_open(&cd->cdi, bdev, mode);
 518		if (ret)
 519			scsi_cd_put(cd);
 520	}
 521	mutex_unlock(&sr_mutex);
 522	return ret;
 523}
 524
 525static int sr_block_release(struct gendisk *disk, fmode_t mode)
 526{
 527	struct scsi_cd *cd = scsi_cd(disk);
 528	mutex_lock(&sr_mutex);
 529	cdrom_release(&cd->cdi, mode);
 530	scsi_cd_put(cd);
 531	mutex_unlock(&sr_mutex);
 532	return 0;
 533}
 534
 535static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 536			  unsigned long arg)
 537{
 538	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 539	struct scsi_device *sdev = cd->device;
 540	void __user *argp = (void __user *)arg;
 541	int ret;
 542
 543	mutex_lock(&sr_mutex);
 544
 545	/*
 546	 * Send SCSI addressing ioctls directly to mid level, send other
 547	 * ioctls to cdrom/block level.
 548	 */
 549	switch (cmd) {
 550	case SCSI_IOCTL_GET_IDLUN:
 551	case SCSI_IOCTL_GET_BUS_NUMBER:
 552		ret = scsi_ioctl(sdev, cmd, argp);
 553		goto out;
 554	}
 555
 556	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
 557	if (ret != -ENOSYS)
 558		goto out;
 559
 560	/*
 561	 * ENODEV means that we didn't recognise the ioctl, or that we
 562	 * cannot execute it in the current device state.  In either
 563	 * case fall through to scsi_ioctl, which will return ENDOEV again
 564	 * if it doesn't recognise the ioctl
 565	 */
 566	ret = scsi_nonblockable_ioctl(sdev, cmd, argp,
 567					(mode & FMODE_NDELAY) != 0);
 568	if (ret != -ENODEV)
 569		goto out;
 570	ret = scsi_ioctl(sdev, cmd, argp);
 571
 572out:
 573	mutex_unlock(&sr_mutex);
 574	return ret;
 575}
 576
 577static unsigned int sr_block_check_events(struct gendisk *disk,
 578					  unsigned int clearing)
 579{
 580	struct scsi_cd *cd = scsi_cd(disk);
 581	return cdrom_check_events(&cd->cdi, clearing);
 582}
 583
 584static int sr_block_revalidate_disk(struct gendisk *disk)
 585{
 586	struct scsi_cd *cd = scsi_cd(disk);
 587	struct scsi_sense_hdr sshdr;
 588
 589	/* if the unit is not ready, nothing more to do */
 590	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 591		return 0;
 592
 593	sr_cd_check(&cd->cdi);
 594	get_sectorsize(cd);
 595	return 0;
 596}
 597
 598static const struct block_device_operations sr_bdops =
 599{
 600	.owner		= THIS_MODULE,
 601	.open		= sr_block_open,
 602	.release	= sr_block_release,
 603	.ioctl		= sr_block_ioctl,
 604	.check_events	= sr_block_check_events,
 605	.revalidate_disk = sr_block_revalidate_disk,
 606	/* 
 607	 * No compat_ioctl for now because sr_block_ioctl never
 608	 * seems to pass arbitrary ioctls down to host drivers.
 609	 */
 610};
 611
 612static int sr_open(struct cdrom_device_info *cdi, int purpose)
 613{
 614	struct scsi_cd *cd = cdi->handle;
 615	struct scsi_device *sdev = cd->device;
 616	int retval;
 617
 618	/*
 619	 * If the device is in error recovery, wait until it is done.
 620	 * If the device is offline, then disallow any access to it.
 621	 */
 622	retval = -ENXIO;
 623	if (!scsi_block_when_processing_errors(sdev))
 624		goto error_out;
 625
 626	return 0;
 627
 628error_out:
 629	return retval;	
 630}
 631
 632static void sr_release(struct cdrom_device_info *cdi)
 633{
 634	struct scsi_cd *cd = cdi->handle;
 635
 636	if (cd->device->sector_size > 2048)
 637		sr_set_blocklength(cd, 2048);
 638
 639}
 640
 641static int sr_probe(struct device *dev)
 642{
 643	struct scsi_device *sdev = to_scsi_device(dev);
 644	struct gendisk *disk;
 645	struct scsi_cd *cd;
 646	int minor, error;
 647
 648	error = -ENODEV;
 649	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
 650		goto fail;
 651
 652	error = -ENOMEM;
 653	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 654	if (!cd)
 655		goto fail;
 656
 657	kref_init(&cd->kref);
 658
 659	disk = alloc_disk(1);
 660	if (!disk)
 661		goto fail_free;
 662
 663	spin_lock(&sr_index_lock);
 664	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
 665	if (minor == SR_DISKS) {
 666		spin_unlock(&sr_index_lock);
 667		error = -EBUSY;
 668		goto fail_put;
 669	}
 670	__set_bit(minor, sr_index_bits);
 671	spin_unlock(&sr_index_lock);
 672
 673	disk->major = SCSI_CDROM_MAJOR;
 674	disk->first_minor = minor;
 675	sprintf(disk->disk_name, "sr%d", minor);
 676	disk->fops = &sr_bdops;
 677	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 678	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 679
 680	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 681
 682	cd->device = sdev;
 683	cd->disk = disk;
 684	cd->driver = &sr_template;
 685	cd->disk = disk;
 686	cd->capacity = 0x1fffff;
 687	cd->device->changed = 1;	/* force recheck CD type */
 688	cd->media_present = 1;
 689	cd->use = 1;
 690	cd->readcd_known = 0;
 691	cd->readcd_cdda = 0;
 692
 693	cd->cdi.ops = &sr_dops;
 694	cd->cdi.handle = cd;
 695	cd->cdi.mask = 0;
 696	cd->cdi.capacity = 1;
 697	sprintf(cd->cdi.name, "sr%d", minor);
 698
 699	sdev->sector_size = 2048;	/* A guess, just in case */
 700
 701	/* FIXME: need to handle a get_capabilities failure properly ?? */
 702	get_capabilities(cd);
 703	blk_queue_prep_rq(sdev->request_queue, sr_prep_fn);
 704	sr_vendor_init(cd);
 705
 706	disk->driverfs_dev = &sdev->sdev_gendev;
 707	set_capacity(disk, cd->capacity);
 708	disk->private_data = &cd->driver;
 709	disk->queue = sdev->request_queue;
 710	cd->cdi.disk = disk;
 711
 712	if (register_cdrom(&cd->cdi))
 713		goto fail_put;
 714
 715	dev_set_drvdata(dev, cd);
 716	disk->flags |= GENHD_FL_REMOVABLE;
 717	add_disk(disk);
 718
 719	sdev_printk(KERN_DEBUG, sdev,
 720		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
 721	return 0;
 722
 723fail_put:
 724	put_disk(disk);
 725fail_free:
 726	kfree(cd);
 727fail:
 728	return error;
 729}
 730
 731
 732static void get_sectorsize(struct scsi_cd *cd)
 733{
 734	unsigned char cmd[10];
 735	unsigned char buffer[8];
 736	int the_result, retries = 3;
 737	int sector_size;
 738	struct request_queue *queue;
 739
 740	do {
 741		cmd[0] = READ_CAPACITY;
 742		memset((void *) &cmd[1], 0, 9);
 743		memset(buffer, 0, sizeof(buffer));
 744
 745		/* Do the command and wait.. */
 746		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
 747					      buffer, sizeof(buffer), NULL,
 748					      SR_TIMEOUT, MAX_RETRIES, NULL);
 749
 750		retries--;
 751
 752	} while (the_result && retries);
 753
 754
 755	if (the_result) {
 756		cd->capacity = 0x1fffff;
 757		sector_size = 2048;	/* A guess, just in case */
 758	} else {
 759		long last_written;
 760
 761		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
 762				    (buffer[2] << 8) | buffer[3]);
 763		/*
 764		 * READ_CAPACITY doesn't return the correct size on
 765		 * certain UDF media.  If last_written is larger, use
 766		 * it instead.
 767		 *
 768		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
 769		 */
 770		if (!cdrom_get_last_written(&cd->cdi, &last_written))
 771			cd->capacity = max_t(long, cd->capacity, last_written);
 772
 773		sector_size = (buffer[4] << 24) |
 774		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
 775		switch (sector_size) {
 776			/*
 777			 * HP 4020i CD-Recorder reports 2340 byte sectors
 778			 * Philips CD-Writers report 2352 byte sectors
 779			 *
 780			 * Use 2k sectors for them..
 781			 */
 782		case 0:
 783		case 2340:
 784		case 2352:
 785			sector_size = 2048;
 786			/* fall through */
 787		case 2048:
 788			cd->capacity *= 4;
 789			/* fall through */
 790		case 512:
 791			break;
 792		default:
 793			printk("%s: unsupported sector size %d.\n",
 794			       cd->cdi.name, sector_size);
 795			cd->capacity = 0;
 796		}
 797
 798		cd->device->sector_size = sector_size;
 799
 800		/*
 801		 * Add this so that we have the ability to correctly gauge
 802		 * what the device is capable of.
 803		 */
 804		set_capacity(cd->disk, cd->capacity);
 805	}
 806
 807	queue = cd->device->request_queue;
 808	blk_queue_logical_block_size(queue, sector_size);
 809
 810	return;
 811}
 812
 813static void get_capabilities(struct scsi_cd *cd)
 814{
 815	unsigned char *buffer;
 816	struct scsi_mode_data data;
 817	struct scsi_sense_hdr sshdr;
 818	int rc, n;
 819
 820	static const char *loadmech[] =
 821	{
 822		"caddy",
 823		"tray",
 824		"pop-up",
 825		"",
 826		"changer",
 827		"cartridge changer",
 828		"",
 829		""
 830	};
 831
 832
 833	/* allocate transfer buffer */
 834	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 835	if (!buffer) {
 836		printk(KERN_ERR "sr: out of memory.\n");
 837		return;
 838	}
 839
 840	/* eat unit attentions */
 841	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 842
 843	/* ask for mode page 0x2a */
 844	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
 845			     SR_TIMEOUT, 3, &data, NULL);
 846
 847	if (!scsi_status_is_good(rc)) {
 848		/* failed, drive doesn't have capabilities mode page */
 849		cd->cdi.speed = 1;
 850		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
 851				 CDC_DVD | CDC_DVD_RAM |
 852				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
 853				 CDC_MRW | CDC_MRW_W | CDC_RAM);
 854		kfree(buffer);
 855		printk("%s: scsi-1 drive\n", cd->cdi.name);
 856		return;
 857	}
 858
 859	n = data.header_length + data.block_descriptor_length;
 860	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
 861	cd->readcd_known = 1;
 862	cd->readcd_cdda = buffer[n + 5] & 0x01;
 863	/* print some capability bits */
 864	printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
 865	       ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
 866	       cd->cdi.speed,
 867	       buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 868	       buffer[n + 3] & 0x20 ? "dvd-ram " : "",
 869	       buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
 870	       buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
 871	       buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
 872	       loadmech[buffer[n + 6] >> 5]);
 873	if ((buffer[n + 6] >> 5) == 0)
 874		/* caddy drives can't close tray... */
 875		cd->cdi.mask |= CDC_CLOSE_TRAY;
 876	if ((buffer[n + 2] & 0x8) == 0)
 877		/* not a DVD drive */
 878		cd->cdi.mask |= CDC_DVD;
 879	if ((buffer[n + 3] & 0x20) == 0) 
 880		/* can't write DVD-RAM media */
 881		cd->cdi.mask |= CDC_DVD_RAM;
 882	if ((buffer[n + 3] & 0x10) == 0)
 883		/* can't write DVD-R media */
 884		cd->cdi.mask |= CDC_DVD_R;
 885	if ((buffer[n + 3] & 0x2) == 0)
 886		/* can't write CD-RW media */
 887		cd->cdi.mask |= CDC_CD_RW;
 888	if ((buffer[n + 3] & 0x1) == 0)
 889		/* can't write CD-R media */
 890		cd->cdi.mask |= CDC_CD_R;
 891	if ((buffer[n + 6] & 0x8) == 0)
 892		/* can't eject */
 893		cd->cdi.mask |= CDC_OPEN_TRAY;
 894
 895	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
 896	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
 897		cd->cdi.capacity =
 898		    cdrom_number_of_slots(&cd->cdi);
 899	if (cd->cdi.capacity <= 1)
 900		/* not a changer */
 901		cd->cdi.mask |= CDC_SELECT_DISC;
 902	/*else    I don't think it can close its tray
 903		cd->cdi.mask |= CDC_CLOSE_TRAY; */
 904
 905	/*
 906	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
 907	 */
 908	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
 909			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
 910		cd->device->writeable = 1;
 911	}
 912
 913	kfree(buffer);
 914}
 915
 916/*
 917 * sr_packet() is the entry point for the generic commands generated
 918 * by the Uniform CD-ROM layer. 
 919 */
 920static int sr_packet(struct cdrom_device_info *cdi,
 921		struct packet_command *cgc)
 922{
 923	struct scsi_cd *cd = cdi->handle;
 924	struct scsi_device *sdev = cd->device;
 925
 926	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
 927		return -EDRIVE_CANT_DO_THIS;
 928
 929	if (cgc->timeout <= 0)
 930		cgc->timeout = IOCTL_TIMEOUT;
 931
 932	sr_do_ioctl(cd, cgc);
 933
 934	return cgc->stat;
 935}
 936
 937/**
 938 *	sr_kref_release - Called to free the scsi_cd structure
 939 *	@kref: pointer to embedded kref
 940 *
 941 *	sr_ref_mutex must be held entering this routine.  Because it is
 942 *	called on last put, you should always use the scsi_cd_get()
 943 *	scsi_cd_put() helpers which manipulate the semaphore directly
 944 *	and never do a direct kref_put().
 945 **/
 946static void sr_kref_release(struct kref *kref)
 947{
 948	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
 949	struct gendisk *disk = cd->disk;
 950
 951	spin_lock(&sr_index_lock);
 952	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
 953	spin_unlock(&sr_index_lock);
 954
 955	unregister_cdrom(&cd->cdi);
 956
 957	disk->private_data = NULL;
 958
 959	put_disk(disk);
 960
 961	kfree(cd);
 962}
 963
 964static int sr_remove(struct device *dev)
 965{
 966	struct scsi_cd *cd = dev_get_drvdata(dev);
 967
 968	blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
 969	del_gendisk(cd->disk);
 970
 971	mutex_lock(&sr_ref_mutex);
 972	kref_put(&cd->kref, sr_kref_release);
 973	mutex_unlock(&sr_ref_mutex);
 974
 975	return 0;
 976}
 977
 978static int __init init_sr(void)
 979{
 980	int rc;
 981
 982	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
 983	if (rc)
 984		return rc;
 985	rc = scsi_register_driver(&sr_template.gendrv);
 986	if (rc)
 987		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
 988
 989	return rc;
 990}
 991
 992static void __exit exit_sr(void)
 993{
 994	scsi_unregister_driver(&sr_template.gendrv);
 995	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
 996}
 997
 998module_init(init_sr);
 999module_exit(exit_sr);
1000MODULE_LICENSE("GPL");