1/*
   2 * scsi_scan.c
   3 *
   4 * Copyright (C) 2000 Eric Youngdale,
   5 * Copyright (C) 2002 Patrick Mansfield
   6 *
   7 * The general scanning/probing algorithm is as follows, exceptions are
   8 * made to it depending on device specific flags, compilation options, and
   9 * global variable (boot or module load time) settings.
  10 *
  11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
  12 * device attached, a scsi_device is allocated and setup for it.
  13 *
  14 * For every id of every channel on the given host:
  15 *
  16 * 	Scan LUN 0; if the target responds to LUN 0 (even if there is no
  17 * 	device or storage attached to LUN 0):
  18 *
  19 * 		If LUN 0 has a device attached, allocate and setup a
  20 * 		scsi_device for it.
  21 *
  22 * 		If target is SCSI-3 or up, issue a REPORT LUN, and scan
  23 * 		all of the LUNs returned by the REPORT LUN; else,
  24 * 		sequentially scan LUNs up until some maximum is reached,
  25 * 		or a LUN is seen that cannot have a device attached to it.
  26 */
  27
  28#include <linux/module.h>
  29#include <linux/moduleparam.h>
  30#include <linux/init.h>
  31#include <linux/blkdev.h>
  32#include <linux/delay.h>
  33#include <linux/kthread.h>
  34#include <linux/spinlock.h>
  35#include <linux/async.h>
  36#include <linux/slab.h>
 
  37
  38#include <scsi/scsi.h>
  39#include <scsi/scsi_cmnd.h>
  40#include <scsi/scsi_device.h>
  41#include <scsi/scsi_driver.h>
  42#include <scsi/scsi_devinfo.h>
  43#include <scsi/scsi_host.h>
  44#include <scsi/scsi_transport.h>
 
  45#include <scsi/scsi_eh.h>
  46
  47#include "scsi_priv.h"
  48#include "scsi_logging.h"
  49
  50#define ALLOC_FAILURE_MSG	KERN_ERR "%s: Allocation failure during" \
  51	" SCSI scanning, some SCSI devices might not be configured\n"
  52
  53/*
  54 * Default timeout
  55 */
  56#define SCSI_TIMEOUT (2*HZ)
 
  57
  58/*
  59 * Prefix values for the SCSI id's (stored in sysfs name field)
  60 */
  61#define SCSI_UID_SER_NUM 'S'
  62#define SCSI_UID_UNKNOWN 'Z'
  63
  64/*
  65 * Return values of some of the scanning functions.
  66 *
  67 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
  68 * includes allocation or general failures preventing IO from being sent.
  69 *
  70 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
  71 * on the given LUN.
  72 *
  73 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
  74 * given LUN.
  75 */
  76#define SCSI_SCAN_NO_RESPONSE		0
  77#define SCSI_SCAN_TARGET_PRESENT	1
  78#define SCSI_SCAN_LUN_PRESENT		2
  79
  80static const char *scsi_null_device_strs = "nullnullnullnull";
  81
  82#define MAX_SCSI_LUNS	512
  83
  84#ifdef CONFIG_SCSI_MULTI_LUN
  85static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
  86#else
  87static unsigned int max_scsi_luns = 1;
  88#endif
  89
  90module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR);
  91MODULE_PARM_DESC(max_luns,
  92		 "last scsi LUN (should be between 1 and 2^32-1)");
  93
  94#ifdef CONFIG_SCSI_SCAN_ASYNC
  95#define SCSI_SCAN_TYPE_DEFAULT "async"
  96#else
  97#define SCSI_SCAN_TYPE_DEFAULT "sync"
  98#endif
  99
 100char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
 101
 102module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
 103MODULE_PARM_DESC(scan, "sync, async or none");
 104
 105/*
 106 * max_scsi_report_luns: the maximum number of LUNS that will be
 107 * returned from the REPORT LUNS command. 8 times this value must
 108 * be allocated. In theory this could be up to an 8 byte value, but
 109 * in practice, the maximum number of LUNs suppored by any device
 110 * is about 16k.
 111 */
 112static unsigned int max_scsi_report_luns = 511;
 113
 114module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
 115MODULE_PARM_DESC(max_report_luns,
 116		 "REPORT LUNS maximum number of LUNS received (should be"
 117		 " between 1 and 16384)");
 
 118
 119static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
 120
 121module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
 122MODULE_PARM_DESC(inq_timeout, 
 123		 "Timeout (in seconds) waiting for devices to answer INQUIRY."
 124		 " Default is 20. Some devices may need more; most need less.");
 125
 126/* This lock protects only this list */
 127static DEFINE_SPINLOCK(async_scan_lock);
 128static LIST_HEAD(scanning_hosts);
 129
 130struct async_scan_data {
 131	struct list_head list;
 132	struct Scsi_Host *shost;
 133	struct completion prev_finished;
 134};
 135
 136/**
 137 * scsi_complete_async_scans - Wait for asynchronous scans to complete
 138 *
 139 * When this function returns, any host which started scanning before
 140 * this function was called will have finished its scan.  Hosts which
 141 * started scanning after this function was called may or may not have
 142 * finished.
 143 */
 144int scsi_complete_async_scans(void)
 145{
 146	struct async_scan_data *data;
 147
 148	do {
 149		if (list_empty(&scanning_hosts))
 150			return 0;
 151		/* If we can't get memory immediately, that's OK.  Just
 152		 * sleep a little.  Even if we never get memory, the async
 153		 * scans will finish eventually.
 154		 */
 155		data = kmalloc(sizeof(*data), GFP_KERNEL);
 156		if (!data)
 157			msleep(1);
 158	} while (!data);
 159
 160	data->shost = NULL;
 161	init_completion(&data->prev_finished);
 162
 163	spin_lock(&async_scan_lock);
 164	/* Check that there's still somebody else on the list */
 165	if (list_empty(&scanning_hosts))
 166		goto done;
 167	list_add_tail(&data->list, &scanning_hosts);
 168	spin_unlock(&async_scan_lock);
 169
 170	printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
 171	wait_for_completion(&data->prev_finished);
 172
 173	spin_lock(&async_scan_lock);
 174	list_del(&data->list);
 175	if (!list_empty(&scanning_hosts)) {
 176		struct async_scan_data *next = list_entry(scanning_hosts.next,
 177				struct async_scan_data, list);
 178		complete(&next->prev_finished);
 179	}
 180 done:
 181	spin_unlock(&async_scan_lock);
 182
 183	kfree(data);
 184	return 0;
 185}
 186
 187/**
 188 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
 189 * @sdev:	scsi device to send command to
 190 * @result:	area to store the result of the MODE SENSE
 191 *
 192 * Description:
 193 *     Send a vendor specific MODE SENSE (not a MODE SELECT) command.
 194 *     Called for BLIST_KEY devices.
 195 **/
 196static void scsi_unlock_floptical(struct scsi_device *sdev,
 197				  unsigned char *result)
 198{
 199	unsigned char scsi_cmd[MAX_COMMAND_SIZE];
 200
 201	printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
 202	scsi_cmd[0] = MODE_SENSE;
 203	scsi_cmd[1] = 0;
 204	scsi_cmd[2] = 0x2e;
 205	scsi_cmd[3] = 0;
 206	scsi_cmd[4] = 0x2a;     /* size */
 207	scsi_cmd[5] = 0;
 208	scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
 209			 SCSI_TIMEOUT, 3, NULL);
 210}
 211
 212/**
 213 * scsi_alloc_sdev - allocate and setup a scsi_Device
 214 * @starget: which target to allocate a &scsi_device for
 215 * @lun: which lun
 216 * @hostdata: usually NULL and set by ->slave_alloc instead
 217 *
 218 * Description:
 219 *     Allocate, initialize for io, and return a pointer to a scsi_Device.
 220 *     Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
 221 *     adds scsi_Device to the appropriate list.
 222 *
 223 * Return value:
 224 *     scsi_Device pointer, or NULL on failure.
 225 **/
 226static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
 227					   unsigned int lun, void *hostdata)
 228{
 229	struct scsi_device *sdev;
 230	int display_failure_msg = 1, ret;
 231	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 232	extern void scsi_evt_thread(struct work_struct *work);
 233	extern void scsi_requeue_run_queue(struct work_struct *work);
 234
 235	sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
 236		       GFP_ATOMIC);
 237	if (!sdev)
 238		goto out;
 239
 240	sdev->vendor = scsi_null_device_strs;
 241	sdev->model = scsi_null_device_strs;
 242	sdev->rev = scsi_null_device_strs;
 243	sdev->host = shost;
 244	sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
 245	sdev->id = starget->id;
 246	sdev->lun = lun;
 247	sdev->channel = starget->channel;
 
 248	sdev->sdev_state = SDEV_CREATED;
 249	INIT_LIST_HEAD(&sdev->siblings);
 250	INIT_LIST_HEAD(&sdev->same_target_siblings);
 251	INIT_LIST_HEAD(&sdev->cmd_list);
 252	INIT_LIST_HEAD(&sdev->starved_entry);
 253	INIT_LIST_HEAD(&sdev->event_list);
 254	spin_lock_init(&sdev->list_lock);
 
 255	INIT_WORK(&sdev->event_work, scsi_evt_thread);
 256	INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
 257
 258	sdev->sdev_gendev.parent = get_device(&starget->dev);
 259	sdev->sdev_target = starget;
 260
 261	/* usually NULL and set by ->slave_alloc instead */
 262	sdev->hostdata = hostdata;
 263
 264	/* if the device needs this changing, it may do so in the
 265	 * slave_configure function */
 266	sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
 267
 268	/*
 269	 * Some low level driver could use device->type
 270	 */
 271	sdev->type = -1;
 272
 273	/*
 274	 * Assume that the device will have handshaking problems,
 275	 * and then fix this field later if it turns out it
 276	 * doesn't
 277	 */
 278	sdev->borken = 1;
 279
 280	sdev->request_queue = scsi_alloc_queue(sdev);
 
 
 
 281	if (!sdev->request_queue) {
 282		/* release fn is set up in scsi_sysfs_device_initialise, so
 283		 * have to free and put manually here */
 284		put_device(&starget->dev);
 285		kfree(sdev);
 286		goto out;
 287	}
 288	WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
 289	sdev->request_queue->queuedata = sdev;
 290	scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
 
 
 
 
 
 
 
 291
 292	scsi_sysfs_device_initialize(sdev);
 293
 294	if (shost->hostt->slave_alloc) {
 295		ret = shost->hostt->slave_alloc(sdev);
 296		if (ret) {
 297			/*
 298			 * if LLDD reports slave not present, don't clutter
 299			 * console with alloc failure messages
 300			 */
 301			if (ret == -ENXIO)
 302				display_failure_msg = 0;
 303			goto out_device_destroy;
 304		}
 305	}
 306
 307	return sdev;
 308
 309out_device_destroy:
 310	__scsi_remove_device(sdev);
 311out:
 312	if (display_failure_msg)
 313		printk(ALLOC_FAILURE_MSG, __func__);
 314	return NULL;
 315}
 316
 317static void scsi_target_destroy(struct scsi_target *starget)
 318{
 319	struct device *dev = &starget->dev;
 320	struct Scsi_Host *shost = dev_to_shost(dev->parent);
 321	unsigned long flags;
 322
 
 323	starget->state = STARGET_DEL;
 324	transport_destroy_device(dev);
 325	spin_lock_irqsave(shost->host_lock, flags);
 326	if (shost->hostt->target_destroy)
 327		shost->hostt->target_destroy(starget);
 328	list_del_init(&starget->siblings);
 329	spin_unlock_irqrestore(shost->host_lock, flags);
 330	put_device(dev);
 331}
 332
 333static void scsi_target_dev_release(struct device *dev)
 334{
 335	struct device *parent = dev->parent;
 336	struct scsi_target *starget = to_scsi_target(dev);
 337
 338	kfree(starget);
 339	put_device(parent);
 340}
 341
 342static struct device_type scsi_target_type = {
 343	.name =		"scsi_target",
 344	.release =	scsi_target_dev_release,
 345};
 346
 347int scsi_is_target_device(const struct device *dev)
 348{
 349	return dev->type == &scsi_target_type;
 350}
 351EXPORT_SYMBOL(scsi_is_target_device);
 352
 353static struct scsi_target *__scsi_find_target(struct device *parent,
 354					      int channel, uint id)
 355{
 356	struct scsi_target *starget, *found_starget = NULL;
 357	struct Scsi_Host *shost = dev_to_shost(parent);
 358	/*
 359	 * Search for an existing target for this sdev.
 360	 */
 361	list_for_each_entry(starget, &shost->__targets, siblings) {
 362		if (starget->id == id &&
 363		    starget->channel == channel) {
 364			found_starget = starget;
 365			break;
 366		}
 367	}
 368	if (found_starget)
 369		get_device(&found_starget->dev);
 370
 371	return found_starget;
 372}
 373
 374/**
 375 * scsi_target_reap_ref_release - remove target from visibility
 376 * @kref: the reap_ref in the target being released
 377 *
 378 * Called on last put of reap_ref, which is the indication that no device
 379 * under this target is visible anymore, so render the target invisible in
 380 * sysfs.  Note: we have to be in user context here because the target reaps
 381 * should be done in places where the scsi device visibility is being removed.
 382 */
 383static void scsi_target_reap_ref_release(struct kref *kref)
 384{
 385	struct scsi_target *starget
 386		= container_of(kref, struct scsi_target, reap_ref);
 387
 388	/*
 389	 * if we get here and the target is still in the CREATED state that
 390	 * means it was allocated but never made visible (because a scan
 391	 * turned up no LUNs), so don't call device_del() on it.
 392	 */
 393	if (starget->state != STARGET_CREATED) {
 
 394		transport_remove_device(&starget->dev);
 395		device_del(&starget->dev);
 396	}
 397	scsi_target_destroy(starget);
 398}
 399
 400static void scsi_target_reap_ref_put(struct scsi_target *starget)
 401{
 402	kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
 403}
 404
 405/**
 406 * scsi_alloc_target - allocate a new or find an existing target
 407 * @parent:	parent of the target (need not be a scsi host)
 408 * @channel:	target channel number (zero if no channels)
 409 * @id:		target id number
 410 *
 411 * Return an existing target if one exists, provided it hasn't already
 412 * gone into STARGET_DEL state, otherwise allocate a new target.
 413 *
 414 * The target is returned with an incremented reference, so the caller
 415 * is responsible for both reaping and doing a last put
 416 */
 417static struct scsi_target *scsi_alloc_target(struct device *parent,
 418					     int channel, uint id)
 419{
 420	struct Scsi_Host *shost = dev_to_shost(parent);
 421	struct device *dev = NULL;
 422	unsigned long flags;
 423	const int size = sizeof(struct scsi_target)
 424		+ shost->transportt->target_size;
 425	struct scsi_target *starget;
 426	struct scsi_target *found_target;
 427	int error, ref_got;
 428
 429	starget = kzalloc(size, GFP_KERNEL);
 430	if (!starget) {
 431		printk(KERN_ERR "%s: allocation failure\n", __func__);
 432		return NULL;
 433	}
 434	dev = &starget->dev;
 435	device_initialize(dev);
 436	kref_init(&starget->reap_ref);
 437	dev->parent = get_device(parent);
 438	dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
 439	dev->bus = &scsi_bus_type;
 440	dev->type = &scsi_target_type;
 441	starget->id = id;
 442	starget->channel = channel;
 443	starget->can_queue = 0;
 444	INIT_LIST_HEAD(&starget->siblings);
 445	INIT_LIST_HEAD(&starget->devices);
 446	starget->state = STARGET_CREATED;
 447	starget->scsi_level = SCSI_2;
 448	starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
 449 retry:
 450	spin_lock_irqsave(shost->host_lock, flags);
 451
 452	found_target = __scsi_find_target(parent, channel, id);
 453	if (found_target)
 454		goto found;
 455
 456	list_add_tail(&starget->siblings, &shost->__targets);
 457	spin_unlock_irqrestore(shost->host_lock, flags);
 458	/* allocate and add */
 459	transport_setup_device(dev);
 460	if (shost->hostt->target_alloc) {
 461		error = shost->hostt->target_alloc(starget);
 462
 463		if(error) {
 464			dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
 465			/* don't want scsi_target_reap to do the final
 466			 * put because it will be under the host lock */
 467			scsi_target_destroy(starget);
 468			return NULL;
 469		}
 470	}
 471	get_device(dev);
 472
 473	return starget;
 474
 475 found:
 476	/*
 477	 * release routine already fired if kref is zero, so if we can still
 478	 * take the reference, the target must be alive.  If we can't, it must
 479	 * be dying and we need to wait for a new target
 480	 */
 481	ref_got = kref_get_unless_zero(&found_target->reap_ref);
 482
 483	spin_unlock_irqrestore(shost->host_lock, flags);
 484	if (ref_got) {
 485		put_device(dev);
 486		return found_target;
 487	}
 488	/*
 489	 * Unfortunately, we found a dying target; need to wait until it's
 490	 * dead before we can get a new one.  There is an anomaly here.  We
 491	 * *should* call scsi_target_reap() to balance the kref_get() of the
 492	 * reap_ref above.  However, since the target being released, it's
 493	 * already invisible and the reap_ref is irrelevant.  If we call
 494	 * scsi_target_reap() we might spuriously do another device_del() on
 495	 * an already invisible target.
 496	 */
 497	put_device(&found_target->dev);
 498	/*
 499	 * length of time is irrelevant here, we just want to yield the CPU
 500	 * for a tick to avoid busy waiting for the target to die.
 501	 */
 502	msleep(1);
 503	goto retry;
 504}
 505
 506/**
 507 * scsi_target_reap - check to see if target is in use and destroy if not
 508 * @starget: target to be checked
 509 *
 510 * This is used after removing a LUN or doing a last put of the target
 511 * it checks atomically that nothing is using the target and removes
 512 * it if so.
 513 */
 514void scsi_target_reap(struct scsi_target *starget)
 515{
 516	/*
 517	 * serious problem if this triggers: STARGET_DEL is only set in the if
 518	 * the reap_ref drops to zero, so we're trying to do another final put
 519	 * on an already released kref
 520	 */
 521	BUG_ON(starget->state == STARGET_DEL);
 522	scsi_target_reap_ref_put(starget);
 523}
 524
 525/**
 526 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string
 
 527 * @s: INQUIRY result string to sanitize
 528 * @len: length of the string
 529 *
 530 * Description:
 531 *	The SCSI spec says that INQUIRY vendor, product, and revision
 532 *	strings must consist entirely of graphic ASCII characters,
 533 *	padded on the right with spaces.  Since not all devices obey
 534 *	this rule, we will replace non-graphic or non-ASCII characters
 535 *	with spaces.  Exception: a NUL character is interpreted as a
 536 *	string terminator, so all the following characters are set to
 537 *	spaces.
 538 **/
 539static void sanitize_inquiry_string(unsigned char *s, int len)
 540{
 541	int terminated = 0;
 542
 543	for (; len > 0; (--len, ++s)) {
 544		if (*s == 0)
 545			terminated = 1;
 546		if (terminated || *s < 0x20 || *s > 0x7e)
 547			*s = ' ';
 548	}
 549}
 
 550
 551/**
 552 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
 553 * @sdev:	scsi_device to probe
 554 * @inq_result:	area to store the INQUIRY result
 555 * @result_len: len of inq_result
 556 * @bflags:	store any bflags found here
 557 *
 558 * Description:
 559 *     Probe the lun associated with @req using a standard SCSI INQUIRY;
 560 *
 561 *     If the INQUIRY is successful, zero is returned and the
 562 *     INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
 563 *     are copied to the scsi_device any flags value is stored in *@bflags.
 564 **/
 565static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 566			  int result_len, int *bflags)
 567{
 568	unsigned char scsi_cmd[MAX_COMMAND_SIZE];
 569	int first_inquiry_len, try_inquiry_len, next_inquiry_len;
 570	int response_len = 0;
 571	int pass, count, result;
 572	struct scsi_sense_hdr sshdr;
 573
 574	*bflags = 0;
 575
 576	/* Perform up to 3 passes.  The first pass uses a conservative
 577	 * transfer length of 36 unless sdev->inquiry_len specifies a
 578	 * different value. */
 579	first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
 580	try_inquiry_len = first_inquiry_len;
 581	pass = 1;
 582
 583 next_pass:
 584	SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
 585				"scsi scan: INQUIRY pass %d length %d\n",
 586				pass, try_inquiry_len));
 587
 588	/* Each pass gets up to three chances to ignore Unit Attention */
 589	for (count = 0; count < 3; ++count) {
 590		int resid;
 591
 592		memset(scsi_cmd, 0, 6);
 593		scsi_cmd[0] = INQUIRY;
 594		scsi_cmd[4] = (unsigned char) try_inquiry_len;
 595
 596		memset(inq_result, 0, try_inquiry_len);
 597
 598		result = scsi_execute_req(sdev,  scsi_cmd, DMA_FROM_DEVICE,
 599					  inq_result, try_inquiry_len, &sshdr,
 600					  HZ / 2 + HZ * scsi_inq_timeout, 3,
 601					  &resid);
 602
 603		SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
 604				"with code 0x%x\n",
 605				result ? "failed" : "successful", result));
 606
 607		if (result) {
 608			/*
 609			 * not-ready to ready transition [asc/ascq=0x28/0x0]
 610			 * or power-on, reset [asc/ascq=0x29/0x0], continue.
 611			 * INQUIRY should not yield UNIT_ATTENTION
 612			 * but many buggy devices do so anyway. 
 613			 */
 614			if ((driver_byte(result) & DRIVER_SENSE) &&
 615			    scsi_sense_valid(&sshdr)) {
 616				if ((sshdr.sense_key == UNIT_ATTENTION) &&
 617				    ((sshdr.asc == 0x28) ||
 618				     (sshdr.asc == 0x29)) &&
 619				    (sshdr.ascq == 0))
 620					continue;
 621			}
 622		} else {
 623			/*
 624			 * if nothing was transferred, we try
 625			 * again. It's a workaround for some USB
 626			 * devices.
 627			 */
 628			if (resid == try_inquiry_len)
 629				continue;
 630		}
 631		break;
 632	}
 633
 634	if (result == 0) {
 635		sanitize_inquiry_string(&inq_result[8], 8);
 636		sanitize_inquiry_string(&inq_result[16], 16);
 637		sanitize_inquiry_string(&inq_result[32], 4);
 638
 639		response_len = inq_result[4] + 5;
 640		if (response_len > 255)
 641			response_len = first_inquiry_len;	/* sanity */
 642
 643		/*
 644		 * Get any flags for this device.
 645		 *
 646		 * XXX add a bflags to scsi_device, and replace the
 647		 * corresponding bit fields in scsi_device, so bflags
 648		 * need not be passed as an argument.
 649		 */
 650		*bflags = scsi_get_device_flags(sdev, &inq_result[8],
 651				&inq_result[16]);
 652
 653		/* When the first pass succeeds we gain information about
 654		 * what larger transfer lengths might work. */
 655		if (pass == 1) {
 656			if (BLIST_INQUIRY_36 & *bflags)
 657				next_inquiry_len = 36;
 658			else if (BLIST_INQUIRY_58 & *bflags)
 659				next_inquiry_len = 58;
 660			else if (sdev->inquiry_len)
 661				next_inquiry_len = sdev->inquiry_len;
 662			else
 663				next_inquiry_len = response_len;
 664
 665			/* If more data is available perform the second pass */
 666			if (next_inquiry_len > try_inquiry_len) {
 667				try_inquiry_len = next_inquiry_len;
 668				pass = 2;
 669				goto next_pass;
 670			}
 671		}
 672
 673	} else if (pass == 2) {
 674		printk(KERN_INFO "scsi scan: %d byte inquiry failed.  "
 675				"Consider BLIST_INQUIRY_36 for this device\n",
 676				try_inquiry_len);
 
 677
 678		/* If this pass failed, the third pass goes back and transfers
 679		 * the same amount as we successfully got in the first pass. */
 680		try_inquiry_len = first_inquiry_len;
 681		pass = 3;
 682		goto next_pass;
 683	}
 684
 685	/* If the last transfer attempt got an error, assume the
 686	 * peripheral doesn't exist or is dead. */
 687	if (result)
 688		return -EIO;
 689
 690	/* Don't report any more data than the device says is valid */
 691	sdev->inquiry_len = min(try_inquiry_len, response_len);
 692
 693	/*
 694	 * XXX Abort if the response length is less than 36? If less than
 695	 * 32, the lookup of the device flags (above) could be invalid,
 696	 * and it would be possible to take an incorrect action - we do
 697	 * not want to hang because of a short INQUIRY. On the flip side,
 698	 * if the device is spun down or becoming ready (and so it gives a
 699	 * short INQUIRY), an abort here prevents any further use of the
 700	 * device, including spin up.
 701	 *
 702	 * On the whole, the best approach seems to be to assume the first
 703	 * 36 bytes are valid no matter what the device says.  That's
 704	 * better than copying < 36 bytes to the inquiry-result buffer
 705	 * and displaying garbage for the Vendor, Product, or Revision
 706	 * strings.
 707	 */
 708	if (sdev->inquiry_len < 36) {
 709		printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
 710				" using 36\n", sdev->inquiry_len);
 
 
 
 
 711		sdev->inquiry_len = 36;
 712	}
 713
 714	/*
 715	 * Related to the above issue:
 716	 *
 717	 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
 718	 * and if not ready, sent a START_STOP to start (maybe spin up) and
 719	 * then send the INQUIRY again, since the INQUIRY can change after
 720	 * a device is initialized.
 721	 *
 722	 * Ideally, start a device if explicitly asked to do so.  This
 723	 * assumes that a device is spun up on power on, spun down on
 724	 * request, and then spun up on request.
 725	 */
 726
 727	/*
 728	 * The scanning code needs to know the scsi_level, even if no
 729	 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
 730	 * non-zero LUNs can be scanned.
 731	 */
 732	sdev->scsi_level = inq_result[2] & 0x07;
 733	if (sdev->scsi_level >= 2 ||
 734	    (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
 735		sdev->scsi_level++;
 736	sdev->sdev_target->scsi_level = sdev->scsi_level;
 737
 
 
 
 
 
 
 
 
 
 
 738	return 0;
 739}
 740
 741/**
 742 * scsi_add_lun - allocate and fully initialze a scsi_device
 743 * @sdev:	holds information to be stored in the new scsi_device
 744 * @inq_result:	holds the result of a previous INQUIRY to the LUN
 745 * @bflags:	black/white list flag
 746 * @async:	1 if this device is being scanned asynchronously
 747 *
 748 * Description:
 749 *     Initialize the scsi_device @sdev.  Optionally set fields based
 750 *     on values in *@bflags.
 751 *
 752 * Return:
 753 *     SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
 754 *     SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
 755 **/
 756static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
 757		int *bflags, int async)
 758{
 759	int ret;
 760
 761	/*
 762	 * XXX do not save the inquiry, since it can change underneath us,
 763	 * save just vendor/model/rev.
 764	 *
 765	 * Rather than save it and have an ioctl that retrieves the saved
 766	 * value, have an ioctl that executes the same INQUIRY code used
 767	 * in scsi_probe_lun, let user level programs doing INQUIRY
 768	 * scanning run at their own risk, or supply a user level program
 769	 * that can correctly scan.
 770	 */
 771
 772	/*
 773	 * Copy at least 36 bytes of INQUIRY data, so that we don't
 774	 * dereference unallocated memory when accessing the Vendor,
 775	 * Product, and Revision strings.  Badly behaved devices may set
 776	 * the INQUIRY Additional Length byte to a small value, indicating
 777	 * these strings are invalid, but often they contain plausible data
 778	 * nonetheless.  It doesn't matter if the device sent < 36 bytes
 779	 * total, since scsi_probe_lun() initializes inq_result with 0s.
 780	 */
 781	sdev->inquiry = kmemdup(inq_result,
 782				max_t(size_t, sdev->inquiry_len, 36),
 783				GFP_ATOMIC);
 784	if (sdev->inquiry == NULL)
 785		return SCSI_SCAN_NO_RESPONSE;
 786
 787	sdev->vendor = (char *) (sdev->inquiry + 8);
 788	sdev->model = (char *) (sdev->inquiry + 16);
 789	sdev->rev = (char *) (sdev->inquiry + 32);
 790
 791	if (strncmp(sdev->vendor, "ATA     ", 8) == 0) {
 792		/*
 793		 * sata emulation layer device.  This is a hack to work around
 794		 * the SATL power management specifications which state that
 795		 * when the SATL detects the device has gone into standby
 796		 * mode, it shall respond with NOT READY.
 797		 */
 798		sdev->allow_restart = 1;
 799	}
 800
 801	if (*bflags & BLIST_ISROM) {
 802		sdev->type = TYPE_ROM;
 803		sdev->removable = 1;
 804	} else {
 805		sdev->type = (inq_result[0] & 0x1f);
 806		sdev->removable = (inq_result[1] & 0x80) >> 7;
 807	}
 808
 809	switch (sdev->type) {
 810	case TYPE_RBC:
 811	case TYPE_TAPE:
 812	case TYPE_DISK:
 813	case TYPE_PRINTER:
 814	case TYPE_MOD:
 815	case TYPE_PROCESSOR:
 816	case TYPE_SCANNER:
 817	case TYPE_MEDIUM_CHANGER:
 818	case TYPE_ENCLOSURE:
 819	case TYPE_COMM:
 820	case TYPE_RAID:
 821	case TYPE_OSD:
 822		sdev->writeable = 1;
 823		break;
 824	case TYPE_ROM:
 825	case TYPE_WORM:
 826		sdev->writeable = 0;
 827		break;
 828	default:
 829		printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
 830	}
 831
 832	if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
 833		/* RBC and MMC devices can return SCSI-3 compliance and yet
 834		 * still not support REPORT LUNS, so make them act as
 835		 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
 836		 * specifically set */
 837		if ((*bflags & BLIST_REPORTLUN2) == 0)
 838			*bflags |= BLIST_NOREPORTLUN;
 839	}
 840
 841	/*
 842	 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
 843	 * spec says: The device server is capable of supporting the
 844	 * specified peripheral device type on this logical unit. However,
 845	 * the physical device is not currently connected to this logical
 846	 * unit.
 847	 *
 848	 * The above is vague, as it implies that we could treat 001 and
 849	 * 011 the same. Stay compatible with previous code, and create a
 850	 * scsi_device for a PQ of 1
 851	 *
 852	 * Don't set the device offline here; rather let the upper
 853	 * level drivers eval the PQ to decide whether they should
 854	 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
 855	 */ 
 856
 857	sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
 858	sdev->lockable = sdev->removable;
 859	sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
 860
 861	if (sdev->scsi_level >= SCSI_3 ||
 862			(sdev->inquiry_len > 56 && inq_result[56] & 0x04))
 863		sdev->ppr = 1;
 864	if (inq_result[7] & 0x60)
 865		sdev->wdtr = 1;
 866	if (inq_result[7] & 0x10)
 867		sdev->sdtr = 1;
 868
 869	sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
 870			"ANSI: %d%s\n", scsi_device_type(sdev->type),
 871			sdev->vendor, sdev->model, sdev->rev,
 872			sdev->inq_periph_qual, inq_result[2] & 0x07,
 873			(inq_result[3] & 0x0f) == 1 ? " CCS" : "");
 874
 875	if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
 876	    !(*bflags & BLIST_NOTQ))
 877		sdev->tagged_supported = 1;
 
 
 878
 879	/*
 880	 * Some devices (Texel CD ROM drives) have handshaking problems
 881	 * when used with the Seagate controllers. borken is initialized
 882	 * to 1, and then set it to 0 here.
 883	 */
 884	if ((*bflags & BLIST_BORKEN) == 0)
 885		sdev->borken = 0;
 886
 887	if (*bflags & BLIST_NO_ULD_ATTACH)
 888		sdev->no_uld_attach = 1;
 889
 890	/*
 891	 * Apparently some really broken devices (contrary to the SCSI
 892	 * standards) need to be selected without asserting ATN
 893	 */
 894	if (*bflags & BLIST_SELECT_NO_ATN)
 895		sdev->select_no_atn = 1;
 896
 897	/*
 898	 * Maximum 512 sector transfer length
 899	 * broken RA4x00 Compaq Disk Array
 900	 */
 901	if (*bflags & BLIST_MAX_512)
 902		blk_queue_max_hw_sectors(sdev->request_queue, 512);
 
 
 
 
 
 
 903
 904	/*
 905	 * Some devices may not want to have a start command automatically
 906	 * issued when a device is added.
 907	 */
 908	if (*bflags & BLIST_NOSTARTONADD)
 909		sdev->no_start_on_add = 1;
 910
 911	if (*bflags & BLIST_SINGLELUN)
 912		scsi_target(sdev)->single_lun = 1;
 913
 914	sdev->use_10_for_rw = 1;
 915
 916	if (*bflags & BLIST_MS_SKIP_PAGE_08)
 917		sdev->skip_ms_page_8 = 1;
 918
 919	if (*bflags & BLIST_MS_SKIP_PAGE_3F)
 920		sdev->skip_ms_page_3f = 1;
 921
 922	if (*bflags & BLIST_USE_10_BYTE_MS)
 923		sdev->use_10_for_ms = 1;
 924
 925	/* set the device running here so that slave configure
 926	 * may do I/O */
 
 927	ret = scsi_device_set_state(sdev, SDEV_RUNNING);
 928	if (ret) {
 929		ret = scsi_device_set_state(sdev, SDEV_BLOCK);
 
 930
 931		if (ret) {
 932			sdev_printk(KERN_ERR, sdev,
 933				    "in wrong state %s to complete scan\n",
 934				    scsi_device_state_name(sdev->sdev_state));
 935			return SCSI_SCAN_NO_RESPONSE;
 936		}
 937	}
 938
 939	if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
 940		sdev->use_192_bytes_for_3f = 1;
 941
 942	if (*bflags & BLIST_NOT_LOCKABLE)
 943		sdev->lockable = 0;
 944
 945	if (*bflags & BLIST_RETRY_HWERROR)
 946		sdev->retry_hwerror = 1;
 947
 948	if (*bflags & BLIST_NO_DIF)
 949		sdev->no_dif = 1;
 950
 
 
 
 951	sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
 952
 953	if (*bflags & BLIST_SKIP_VPD_PAGES)
 
 
 954		sdev->skip_vpd_pages = 1;
 955
 956	transport_configure_device(&sdev->sdev_gendev);
 957
 958	if (sdev->host->hostt->slave_configure) {
 959		ret = sdev->host->hostt->slave_configure(sdev);
 960		if (ret) {
 961			/*
 962			 * if LLDD reports slave not present, don't clutter
 963			 * console with alloc failure messages
 964			 */
 965			if (ret != -ENXIO) {
 966				sdev_printk(KERN_ERR, sdev,
 967					"failed to configure device\n");
 968			}
 969			return SCSI_SCAN_NO_RESPONSE;
 970		}
 971	}
 972
 973	if (sdev->scsi_level >= SCSI_3)
 974		scsi_attach_vpd(sdev);
 975
 976	sdev->max_queue_depth = sdev->queue_depth;
 
 977
 978	/*
 979	 * Ok, the device is now all set up, we can
 980	 * register it and tell the rest of the kernel
 981	 * about it.
 982	 */
 983	if (!async && scsi_sysfs_add_sdev(sdev) != 0)
 984		return SCSI_SCAN_NO_RESPONSE;
 985
 986	return SCSI_SCAN_LUN_PRESENT;
 987}
 988
 989#ifdef CONFIG_SCSI_LOGGING
 990/** 
 991 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
 992 * @buf:   Output buffer with at least end-first+1 bytes of space
 993 * @inq:   Inquiry buffer (input)
 994 * @first: Offset of string into inq
 995 * @end:   Index after last character in inq
 996 */
 997static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
 998				   unsigned first, unsigned end)
 999{
1000	unsigned term = 0, idx;
1001
1002	for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1003		if (inq[idx+first] > ' ') {
1004			buf[idx] = inq[idx+first];
1005			term = idx+1;
1006		} else {
1007			buf[idx] = ' ';
1008		}
1009	}
1010	buf[term] = 0;
1011	return buf;
1012}
1013#endif
1014
1015/**
1016 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1017 * @starget:	pointer to target device structure
1018 * @lun:	LUN of target device
1019 * @bflagsp:	store bflags here if not NULL
1020 * @sdevp:	probe the LUN corresponding to this scsi_device
1021 * @rescan:     if nonzero skip some code only needed on first scan
 
1022 * @hostdata:	passed to scsi_alloc_sdev()
1023 *
1024 * Description:
1025 *     Call scsi_probe_lun, if a LUN with an attached device is found,
1026 *     allocate and set it up by calling scsi_add_lun.
1027 *
1028 * Return:
1029 *     SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1030 *     SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
 
1031 *         attached at the LUN
1032 *     SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1033 **/
1034static int scsi_probe_and_add_lun(struct scsi_target *starget,
1035				  uint lun, int *bflagsp,
1036				  struct scsi_device **sdevp, int rescan,
 
1037				  void *hostdata)
1038{
1039	struct scsi_device *sdev;
1040	unsigned char *result;
1041	int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
 
1042	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1043
1044	/*
1045	 * The rescan flag is used as an optimization, the first scan of a
1046	 * host adapter calls into here with rescan == 0.
1047	 */
1048	sdev = scsi_device_lookup_by_target(starget, lun);
1049	if (sdev) {
1050		if (rescan || !scsi_device_created(sdev)) {
1051			SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1052				"scsi scan: device exists on %s\n",
1053				dev_name(&sdev->sdev_gendev)));
1054			if (sdevp)
1055				*sdevp = sdev;
1056			else
1057				scsi_device_put(sdev);
1058
1059			if (bflagsp)
1060				*bflagsp = scsi_get_device_flags(sdev,
1061								 sdev->vendor,
1062								 sdev->model);
1063			return SCSI_SCAN_LUN_PRESENT;
1064		}
1065		scsi_device_put(sdev);
1066	} else
1067		sdev = scsi_alloc_sdev(starget, lun, hostdata);
1068	if (!sdev)
1069		goto out;
1070
1071	result = kmalloc(result_len, GFP_ATOMIC |
1072			((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1073	if (!result)
1074		goto out_free_sdev;
1075
1076	if (scsi_probe_lun(sdev, result, result_len, &bflags))
1077		goto out_free_result;
1078
1079	if (bflagsp)
1080		*bflagsp = bflags;
1081	/*
1082	 * result contains valid SCSI INQUIRY data.
1083	 */
1084	if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
1085		/*
1086		 * For a Peripheral qualifier 3 (011b), the SCSI
1087		 * spec says: The device server is not capable of
1088		 * supporting a physical device on this logical
1089		 * unit.
1090		 *
1091		 * For disks, this implies that there is no
1092		 * logical disk configured at sdev->lun, but there
1093		 * is a target id responding.
1094		 */
1095		SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1096				   " peripheral qualifier of 3, device not"
1097				   " added\n"))
1098		if (lun == 0) {
1099			SCSI_LOG_SCAN_BUS(1, {
1100				unsigned char vend[9];
1101				unsigned char mod[17];
1102
1103				sdev_printk(KERN_INFO, sdev,
1104					"scsi scan: consider passing scsi_mod."
1105					"dev_flags=%s:%s:0x240 or 0x1000240\n",
1106					scsi_inq_str(vend, result, 8, 16),
1107					scsi_inq_str(mod, result, 16, 32));
1108			});
1109
1110		}
1111
1112		res = SCSI_SCAN_TARGET_PRESENT;
1113		goto out_free_result;
1114	}
1115
1116	/*
1117	 * Some targets may set slight variations of PQ and PDT to signal
1118	 * that no LUN is present, so don't add sdev in these cases.
1119	 * Two specific examples are:
1120	 * 1) NetApp targets: return PQ=1, PDT=0x1f
1121	 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1122	 *    in the UFI 1.0 spec (we cannot rely on reserved bits).
1123	 *
1124	 * References:
1125	 * 1) SCSI SPC-3, pp. 145-146
1126	 * PQ=1: "A peripheral device having the specified peripheral
1127	 * device type is not connected to this logical unit. However, the
1128	 * device server is capable of supporting the specified peripheral
1129	 * device type on this logical unit."
1130	 * PDT=0x1f: "Unknown or no device type"
1131	 * 2) USB UFI 1.0, p. 20
1132	 * PDT=00h Direct-access device (floppy)
1133	 * PDT=1Fh none (no FDD connected to the requested logical unit)
1134	 */
1135	if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1136	    (result[0] & 0x1f) == 0x1f &&
1137	    !scsi_is_wlun(lun)) {
1138		SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1139					"scsi scan: peripheral device type"
1140					" of 31, no device added\n"));
1141		res = SCSI_SCAN_TARGET_PRESENT;
1142		goto out_free_result;
1143	}
1144
1145	res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1146	if (res == SCSI_SCAN_LUN_PRESENT) {
1147		if (bflags & BLIST_KEY) {
1148			sdev->lockable = 0;
1149			scsi_unlock_floptical(sdev, result);
1150		}
1151	}
1152
1153 out_free_result:
1154	kfree(result);
1155 out_free_sdev:
1156	if (res == SCSI_SCAN_LUN_PRESENT) {
1157		if (sdevp) {
1158			if (scsi_device_get(sdev) == 0) {
1159				*sdevp = sdev;
1160			} else {
1161				__scsi_remove_device(sdev);
1162				res = SCSI_SCAN_NO_RESPONSE;
1163			}
1164		}
1165	} else
1166		__scsi_remove_device(sdev);
1167 out:
1168	return res;
1169}
1170
1171/**
1172 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1173 * @starget:	pointer to target structure to scan
1174 * @bflags:	black/white list flag for LUN 0
1175 * @scsi_level: Which version of the standard does this device adhere to
1176 * @rescan:     passed to scsi_probe_add_lun()
1177 *
1178 * Description:
1179 *     Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1180 *     scanned) to some maximum lun until a LUN is found with no device
1181 *     attached. Use the bflags to figure out any oddities.
1182 *
1183 *     Modifies sdevscan->lun.
1184 **/
1185static void scsi_sequential_lun_scan(struct scsi_target *starget,
1186				     int bflags, int scsi_level, int rescan)
 
1187{
1188	unsigned int sparse_lun, lun, max_dev_lun;
 
1189	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1190
1191	SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
1192				    "%s\n", dev_name(&starget->dev)));
1193
1194	max_dev_lun = min(max_scsi_luns, shost->max_lun);
1195	/*
1196	 * If this device is known to support sparse multiple units,
1197	 * override the other settings, and scan all of them. Normally,
1198	 * SCSI-3 devices should be scanned via the REPORT LUNS.
1199	 */
1200	if (bflags & BLIST_SPARSELUN) {
1201		max_dev_lun = shost->max_lun;
1202		sparse_lun = 1;
1203	} else
1204		sparse_lun = 0;
1205
1206	/*
1207	 * If less than SCSI_1_CSS, and no special lun scaning, stop
1208	 * scanning; this matches 2.4 behaviour, but could just be a bug
1209	 * (to continue scanning a SCSI_1_CSS device).
1210	 *
1211	 * This test is broken.  We might not have any device on lun0 for
1212	 * a sparselun device, and if that's the case then how would we
1213	 * know the real scsi_level, eh?  It might make sense to just not
1214	 * scan any SCSI_1 device for non-0 luns, but that check would best
1215	 * go into scsi_alloc_sdev() and just have it return null when asked
1216	 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1217	 *
1218	if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1219	    ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1220	     == 0))
1221		return;
1222	 */
1223	/*
1224	 * If this device is known to support multiple units, override
1225	 * the other settings, and scan all of them.
1226	 */
1227	if (bflags & BLIST_FORCELUN)
1228		max_dev_lun = shost->max_lun;
1229	/*
1230	 * REGAL CDC-4X: avoid hang after LUN 4
1231	 */
1232	if (bflags & BLIST_MAX5LUN)
1233		max_dev_lun = min(5U, max_dev_lun);
1234	/*
1235	 * Do not scan SCSI-2 or lower device past LUN 7, unless
1236	 * BLIST_LARGELUN.
1237	 */
1238	if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1239		max_dev_lun = min(8U, max_dev_lun);
 
 
1240
1241	/*
1242	 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1243	 * until we reach the max, or no LUN is found and we are not
1244	 * sparse_lun.
1245	 */
1246	for (lun = 1; lun < max_dev_lun; ++lun)
1247		if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1248					    NULL) != SCSI_SCAN_LUN_PRESENT) &&
1249		    !sparse_lun)
1250			return;
1251}
1252
1253/**
1254 * scsilun_to_int - convert a scsi_lun to an int
1255 * @scsilun:	struct scsi_lun to be converted.
1256 *
1257 * Description:
1258 *     Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1259 *     integer, and return the result. The caller must check for
1260 *     truncation before using this function.
1261 *
1262 * Notes:
1263 *     The struct scsi_lun is assumed to be four levels, with each level
1264 *     effectively containing a SCSI byte-ordered (big endian) short; the
1265 *     addressing bits of each level are ignored (the highest two bits).
1266 *     For a description of the LUN format, post SCSI-3 see the SCSI
1267 *     Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1268 *
1269 *     Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1270 *     the integer: 0x0b030a04
1271 **/
1272int scsilun_to_int(struct scsi_lun *scsilun)
1273{
1274	int i;
1275	unsigned int lun;
1276
1277	lun = 0;
1278	for (i = 0; i < sizeof(lun); i += 2)
1279		lun = lun | (((scsilun->scsi_lun[i] << 8) |
1280			      scsilun->scsi_lun[i + 1]) << (i * 8));
1281	return lun;
1282}
1283EXPORT_SYMBOL(scsilun_to_int);
1284
1285/**
1286 * int_to_scsilun - reverts an int into a scsi_lun
1287 * @lun:        integer to be reverted
1288 * @scsilun:	struct scsi_lun to be set.
1289 *
1290 * Description:
1291 *     Reverts the functionality of the scsilun_to_int, which packed
1292 *     an 8-byte lun value into an int. This routine unpacks the int
1293 *     back into the lun value.
1294 *     Note: the scsilun_to_int() routine does not truly handle all
1295 *     8bytes of the lun value. This functions restores only as much
1296 *     as was set by the routine.
1297 *
1298 * Notes:
1299 *     Given an integer : 0x0b030a04,  this function returns a
1300 *     scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1301 *
1302 **/
1303void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1304{
1305	int i;
1306
1307	memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1308
1309	for (i = 0; i < sizeof(lun); i += 2) {
1310		scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1311		scsilun->scsi_lun[i+1] = lun & 0xFF;
1312		lun = lun >> 16;
1313	}
1314}
1315EXPORT_SYMBOL(int_to_scsilun);
1316
1317/**
1318 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1319 * @starget: which target
1320 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1321 * @rescan: nonzero if we can skip code only needed on first scan
1322 *
1323 * Description:
1324 *   Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1325 *   Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1326 *
1327 *   If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1328 *   LUNs even if it's older than SCSI-3.
1329 *   If BLIST_NOREPORTLUN is set, return 1 always.
1330 *   If BLIST_NOLUN is set, return 0 always.
1331 *   If starget->no_report_luns is set, return 1 always.
1332 *
1333 * Return:
1334 *     0: scan completed (or no memory, so further scanning is futile)
1335 *     1: could not scan with REPORT LUN
1336 **/
1337static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1338				int rescan)
1339{
1340	char devname[64];
1341	unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1342	unsigned int length;
1343	unsigned int lun;
1344	unsigned int num_luns;
1345	unsigned int retries;
1346	int result;
1347	struct scsi_lun *lunp, *lun_data;
1348	u8 *data;
1349	struct scsi_sense_hdr sshdr;
1350	struct scsi_device *sdev;
1351	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1352	int ret = 0;
1353
1354	/*
1355	 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1356	 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1357	 * support more than 8 LUNs.
1358	 * Don't attempt if the target doesn't support REPORT LUNS.
1359	 */
1360	if (bflags & BLIST_NOREPORTLUN)
1361		return 1;
1362	if (starget->scsi_level < SCSI_2 &&
1363	    starget->scsi_level != SCSI_UNKNOWN)
1364		return 1;
1365	if (starget->scsi_level < SCSI_3 &&
1366	    (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1367		return 1;
1368	if (bflags & BLIST_NOLUN)
1369		return 0;
1370	if (starget->no_report_luns)
1371		return 1;
1372
1373	if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1374		sdev = scsi_alloc_sdev(starget, 0, NULL);
1375		if (!sdev)
1376			return 0;
1377		if (scsi_device_get(sdev)) {
1378			__scsi_remove_device(sdev);
1379			return 0;
1380		}
1381	}
1382
1383	sprintf(devname, "host %d channel %d id %d",
1384		shost->host_no, sdev->channel, sdev->id);
1385
1386	/*
1387	 * Allocate enough to hold the header (the same size as one scsi_lun)
1388	 * plus the max number of luns we are requesting.
1389	 *
1390	 * Reallocating and trying again (with the exact amount we need)
1391	 * would be nice, but then we need to somehow limit the size
1392	 * allocated based on the available memory and the limits of
1393	 * kmalloc - we don't want a kmalloc() failure of a huge value to
1394	 * prevent us from finding any LUNs on this target.
1395	 */
1396	length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1397	lun_data = kmalloc(length, GFP_ATOMIC |
 
1398			   (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1399	if (!lun_data) {
1400		printk(ALLOC_FAILURE_MSG, __func__);
1401		goto out;
1402	}
1403
1404	scsi_cmd[0] = REPORT_LUNS;
1405
1406	/*
1407	 * bytes 1 - 5: reserved, set to zero.
1408	 */
1409	memset(&scsi_cmd[1], 0, 5);
1410
1411	/*
1412	 * bytes 6 - 9: length of the command.
1413	 */
1414	scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1415	scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1416	scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1417	scsi_cmd[9] = (unsigned char) length & 0xff;
1418
1419	scsi_cmd[10] = 0;	/* reserved */
1420	scsi_cmd[11] = 0;	/* control */
1421
1422	/*
1423	 * We can get a UNIT ATTENTION, for example a power on/reset, so
1424	 * retry a few times (like sd.c does for TEST UNIT READY).
1425	 * Experience shows some combinations of adapter/devices get at
1426	 * least two power on/resets.
1427	 *
1428	 * Illegal requests (for devices that do not support REPORT LUNS)
1429	 * should come through as a check condition, and will not generate
1430	 * a retry.
1431	 */
1432	for (retries = 0; retries < 3; retries++) {
1433		SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1434				" REPORT LUNS to %s (try %d)\n", devname,
1435				retries));
1436
1437		result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1438					  lun_data, length, &sshdr,
1439					  SCSI_TIMEOUT + 4 * HZ, 3, NULL);
1440
1441		SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1442				" %s (try %d) result 0x%x\n", result
1443				?  "failed" : "successful", retries, result));
 
 
1444		if (result == 0)
1445			break;
1446		else if (scsi_sense_valid(&sshdr)) {
1447			if (sshdr.sense_key != UNIT_ATTENTION)
1448				break;
1449		}
1450	}
1451
1452	if (result) {
1453		/*
1454		 * The device probably does not support a REPORT LUN command
1455		 */
1456		ret = 1;
1457		goto out_err;
1458	}
1459
1460	/*
1461	 * Get the length from the first four bytes of lun_data.
1462	 */
1463	data = (u8 *) lun_data->scsi_lun;
1464	length = ((data[0] << 24) | (data[1] << 16) |
1465		  (data[2] << 8) | (data[3] << 0));
 
 
 
 
 
1466
1467	num_luns = (length / sizeof(struct scsi_lun));
1468	if (num_luns > max_scsi_report_luns) {
1469		printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1470		       " of %d luns reported, try increasing"
1471		       " max_scsi_report_luns.\n", devname,
1472		       max_scsi_report_luns, num_luns);
1473		num_luns = max_scsi_report_luns;
1474	}
1475
1476	SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1477		"scsi scan: REPORT LUN scan\n"));
1478
1479	/*
1480	 * Scan the luns in lun_data. The entry at offset 0 is really
1481	 * the header, so start at 1 and go up to and including num_luns.
1482	 */
1483	for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1484		lun = scsilun_to_int(lunp);
1485
1486		/*
1487		 * Check if the unused part of lunp is non-zero, and so
1488		 * does not fit in lun.
1489		 */
1490		if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1491			int i;
1492
1493			/*
1494			 * Output an error displaying the LUN in byte order,
1495			 * this differs from what linux would print for the
1496			 * integer LUN value.
1497			 */
1498			printk(KERN_WARNING "scsi: %s lun 0x", devname);
1499			data = (char *)lunp->scsi_lun;
1500			for (i = 0; i < sizeof(struct scsi_lun); i++)
1501				printk("%02x", data[i]);
1502			printk(" has a LUN larger than currently supported.\n");
1503		} else if (lun > sdev->host->max_lun) {
1504			printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1505			       " than allowed by the host adapter\n",
1506			       devname, lun);
1507		} else {
1508			int res;
1509
1510			res = scsi_probe_and_add_lun(starget,
1511				lun, NULL, NULL, rescan, NULL);
1512			if (res == SCSI_SCAN_NO_RESPONSE) {
1513				/*
1514				 * Got some results, but now none, abort.
1515				 */
1516				sdev_printk(KERN_ERR, sdev,
1517					"Unexpected response"
1518				        " from lun %d while scanning, scan"
1519				        " aborted\n", lun);
1520				break;
1521			}
1522		}
1523	}
1524
1525 out_err:
1526	kfree(lun_data);
1527 out:
1528	scsi_device_put(sdev);
1529	if (scsi_device_created(sdev))
1530		/*
1531		 * the sdev we used didn't appear in the report luns scan
1532		 */
1533		__scsi_remove_device(sdev);
 
1534	return ret;
1535}
1536
1537struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1538				      uint id, uint lun, void *hostdata)
1539{
1540	struct scsi_device *sdev = ERR_PTR(-ENODEV);
1541	struct device *parent = &shost->shost_gendev;
1542	struct scsi_target *starget;
1543
1544	if (strncmp(scsi_scan_type, "none", 4) == 0)
1545		return ERR_PTR(-ENODEV);
1546
1547	starget = scsi_alloc_target(parent, channel, id);
1548	if (!starget)
1549		return ERR_PTR(-ENOMEM);
1550	scsi_autopm_get_target(starget);
1551
1552	mutex_lock(&shost->scan_mutex);
1553	if (!shost->async_scan)
1554		scsi_complete_async_scans();
1555
1556	if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1557		scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1558		scsi_autopm_put_host(shost);
1559	}
1560	mutex_unlock(&shost->scan_mutex);
1561	scsi_autopm_put_target(starget);
1562	/*
1563	 * paired with scsi_alloc_target().  Target will be destroyed unless
1564	 * scsi_probe_and_add_lun made an underlying device visible
1565	 */
1566	scsi_target_reap(starget);
1567	put_device(&starget->dev);
1568
1569	return sdev;
1570}
1571EXPORT_SYMBOL(__scsi_add_device);
1572
1573int scsi_add_device(struct Scsi_Host *host, uint channel,
1574		    uint target, uint lun)
1575{
1576	struct scsi_device *sdev = 
1577		__scsi_add_device(host, channel, target, lun, NULL);
1578	if (IS_ERR(sdev))
1579		return PTR_ERR(sdev);
1580
1581	scsi_device_put(sdev);
1582	return 0;
1583}
1584EXPORT_SYMBOL(scsi_add_device);
1585
1586void scsi_rescan_device(struct device *dev)
1587{
1588	struct scsi_driver *drv;
1589	
1590	if (!dev->driver)
1591		return;
 
 
 
 
 
 
 
1592
1593	drv = to_scsi_driver(dev->driver);
1594	if (try_module_get(drv->owner)) {
1595		if (drv->rescan)
1596			drv->rescan(dev);
1597		module_put(drv->owner);
1598	}
 
1599}
1600EXPORT_SYMBOL(scsi_rescan_device);
1601
1602static void __scsi_scan_target(struct device *parent, unsigned int channel,
1603		unsigned int id, unsigned int lun, int rescan)
1604{
1605	struct Scsi_Host *shost = dev_to_shost(parent);
1606	int bflags = 0;
1607	int res;
1608	struct scsi_target *starget;
1609
1610	if (shost->this_id == id)
1611		/*
1612		 * Don't scan the host adapter
1613		 */
1614		return;
1615
1616	starget = scsi_alloc_target(parent, channel, id);
1617	if (!starget)
1618		return;
1619	scsi_autopm_get_target(starget);
1620
1621	if (lun != SCAN_WILD_CARD) {
1622		/*
1623		 * Scan for a specific host/chan/id/lun.
1624		 */
1625		scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1626		goto out_reap;
1627	}
1628
1629	/*
1630	 * Scan LUN 0, if there is some response, scan further. Ideally, we
1631	 * would not configure LUN 0 until all LUNs are scanned.
1632	 */
1633	res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1634	if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1635		if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1636			/*
1637			 * The REPORT LUN did not scan the target,
1638			 * do a sequential scan.
1639			 */
1640			scsi_sequential_lun_scan(starget, bflags,
1641						 starget->scsi_level, rescan);
1642	}
1643
1644 out_reap:
1645	scsi_autopm_put_target(starget);
1646	/*
1647	 * paired with scsi_alloc_target(): determine if the target has
1648	 * any children at all and if not, nuke it
1649	 */
1650	scsi_target_reap(starget);
1651
1652	put_device(&starget->dev);
1653}
1654
1655/**
1656 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1657 * @parent:	host to scan
1658 * @channel:	channel to scan
1659 * @id:		target id to scan
1660 * @lun:	Specific LUN to scan or SCAN_WILD_CARD
1661 * @rescan:	passed to LUN scanning routines
 
 
 
1662 *
1663 * Description:
1664 *     Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1665 *     and possibly all LUNs on the target id.
1666 *
1667 *     First try a REPORT LUN scan, if that does not scan the target, do a
1668 *     sequential scan of LUNs on the target id.
1669 **/
1670void scsi_scan_target(struct device *parent, unsigned int channel,
1671		      unsigned int id, unsigned int lun, int rescan)
1672{
1673	struct Scsi_Host *shost = dev_to_shost(parent);
1674
1675	if (strncmp(scsi_scan_type, "none", 4) == 0)
1676		return;
1677
 
 
 
 
1678	mutex_lock(&shost->scan_mutex);
1679	if (!shost->async_scan)
1680		scsi_complete_async_scans();
1681
1682	if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1683		__scsi_scan_target(parent, channel, id, lun, rescan);
1684		scsi_autopm_put_host(shost);
1685	}
1686	mutex_unlock(&shost->scan_mutex);
1687}
1688EXPORT_SYMBOL(scsi_scan_target);
1689
1690static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1691			      unsigned int id, unsigned int lun, int rescan)
 
1692{
1693	uint order_id;
1694
1695	if (id == SCAN_WILD_CARD)
1696		for (id = 0; id < shost->max_id; ++id) {
1697			/*
1698			 * XXX adapter drivers when possible (FCP, iSCSI)
1699			 * could modify max_id to match the current max,
1700			 * not the absolute max.
1701			 *
1702			 * XXX add a shost id iterator, so for example,
1703			 * the FC ID can be the same as a target id
1704			 * without a huge overhead of sparse id's.
1705			 */
1706			if (shost->reverse_ordering)
1707				/*
1708				 * Scan from high to low id.
1709				 */
1710				order_id = shost->max_id - id - 1;
1711			else
1712				order_id = id;
1713			__scsi_scan_target(&shost->shost_gendev, channel,
1714					order_id, lun, rescan);
1715		}
1716	else
1717		__scsi_scan_target(&shost->shost_gendev, channel,
1718				id, lun, rescan);
1719}
1720
1721int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1722			    unsigned int id, unsigned int lun, int rescan)
 
1723{
1724	SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1725		"%s: <%u:%u:%u>\n",
1726		__func__, channel, id, lun));
1727
1728	if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1729	    ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1730	    ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1731		return -EINVAL;
1732
1733	mutex_lock(&shost->scan_mutex);
1734	if (!shost->async_scan)
1735		scsi_complete_async_scans();
1736
1737	if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1738		if (channel == SCAN_WILD_CARD)
1739			for (channel = 0; channel <= shost->max_channel;
1740			     channel++)
1741				scsi_scan_channel(shost, channel, id, lun,
1742						  rescan);
1743		else
1744			scsi_scan_channel(shost, channel, id, lun, rescan);
1745		scsi_autopm_put_host(shost);
1746	}
1747	mutex_unlock(&shost->scan_mutex);
1748
1749	return 0;
1750}
1751
1752static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1753{
1754	struct scsi_device *sdev;
1755	shost_for_each_device(sdev, shost) {
1756		/* target removed before the device could be added */
1757		if (sdev->sdev_state == SDEV_DEL)
1758			continue;
 
 
 
1759		if (!scsi_host_scan_allowed(shost) ||
1760		    scsi_sysfs_add_sdev(sdev) != 0)
1761			__scsi_remove_device(sdev);
1762	}
1763}
1764
1765/**
1766 * scsi_prep_async_scan - prepare for an async scan
1767 * @shost: the host which will be scanned
1768 * Returns: a cookie to be passed to scsi_finish_async_scan()
1769 *
1770 * Tells the midlayer this host is going to do an asynchronous scan.
1771 * It reserves the host's position in the scanning list and ensures
1772 * that other asynchronous scans started after this one won't affect the
1773 * ordering of the discovered devices.
1774 */
1775static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1776{
1777	struct async_scan_data *data;
1778	unsigned long flags;
1779
1780	if (strncmp(scsi_scan_type, "sync", 4) == 0)
1781		return NULL;
1782
1783	if (shost->async_scan) {
1784		printk("%s called twice for host %d", __func__,
1785				shost->host_no);
1786		dump_stack();
1787		return NULL;
1788	}
1789
1790	data = kmalloc(sizeof(*data), GFP_KERNEL);
1791	if (!data)
1792		goto err;
1793	data->shost = scsi_host_get(shost);
1794	if (!data->shost)
1795		goto err;
1796	init_completion(&data->prev_finished);
1797
1798	mutex_lock(&shost->scan_mutex);
1799	spin_lock_irqsave(shost->host_lock, flags);
1800	shost->async_scan = 1;
1801	spin_unlock_irqrestore(shost->host_lock, flags);
1802	mutex_unlock(&shost->scan_mutex);
1803
1804	spin_lock(&async_scan_lock);
1805	if (list_empty(&scanning_hosts))
1806		complete(&data->prev_finished);
1807	list_add_tail(&data->list, &scanning_hosts);
1808	spin_unlock(&async_scan_lock);
1809
1810	return data;
1811
1812 err:
1813	kfree(data);
1814	return NULL;
1815}
1816
1817/**
1818 * scsi_finish_async_scan - asynchronous scan has finished
1819 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1820 *
1821 * All the devices currently attached to this host have been found.
1822 * This function announces all the devices it has found to the rest
1823 * of the system.
1824 */
1825static void scsi_finish_async_scan(struct async_scan_data *data)
1826{
1827	struct Scsi_Host *shost;
1828	unsigned long flags;
1829
1830	if (!data)
1831		return;
1832
1833	shost = data->shost;
1834
1835	mutex_lock(&shost->scan_mutex);
1836
1837	if (!shost->async_scan) {
1838		printk("%s called twice for host %d", __func__,
1839				shost->host_no);
1840		dump_stack();
1841		mutex_unlock(&shost->scan_mutex);
1842		return;
1843	}
1844
1845	wait_for_completion(&data->prev_finished);
1846
1847	scsi_sysfs_add_devices(shost);
1848
1849	spin_lock_irqsave(shost->host_lock, flags);
1850	shost->async_scan = 0;
1851	spin_unlock_irqrestore(shost->host_lock, flags);
1852
1853	mutex_unlock(&shost->scan_mutex);
1854
1855	spin_lock(&async_scan_lock);
1856	list_del(&data->list);
1857	if (!list_empty(&scanning_hosts)) {
1858		struct async_scan_data *next = list_entry(scanning_hosts.next,
1859				struct async_scan_data, list);
1860		complete(&next->prev_finished);
1861	}
1862	spin_unlock(&async_scan_lock);
1863
1864	scsi_autopm_put_host(shost);
1865	scsi_host_put(shost);
1866	kfree(data);
1867}
1868
1869static void do_scsi_scan_host(struct Scsi_Host *shost)
1870{
1871	if (shost->hostt->scan_finished) {
1872		unsigned long start = jiffies;
1873		if (shost->hostt->scan_start)
1874			shost->hostt->scan_start(shost);
1875
1876		while (!shost->hostt->scan_finished(shost, jiffies - start))
1877			msleep(10);
1878	} else {
1879		scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1880				SCAN_WILD_CARD, 0);
1881	}
1882}
1883
1884static void do_scan_async(void *_data, async_cookie_t c)
1885{
1886	struct async_scan_data *data = _data;
1887	struct Scsi_Host *shost = data->shost;
1888
1889	do_scsi_scan_host(shost);
1890	scsi_finish_async_scan(data);
1891}
1892
1893/**
1894 * scsi_scan_host - scan the given adapter
1895 * @shost:	adapter to scan
1896 **/
1897void scsi_scan_host(struct Scsi_Host *shost)
1898{
1899	struct async_scan_data *data;
1900
1901	if (strncmp(scsi_scan_type, "none", 4) == 0)
 
1902		return;
1903	if (scsi_autopm_get_host(shost) < 0)
1904		return;
1905
1906	data = scsi_prep_async_scan(shost);
1907	if (!data) {
1908		do_scsi_scan_host(shost);
1909		scsi_autopm_put_host(shost);
1910		return;
1911	}
1912
1913	/* register with the async subsystem so wait_for_device_probe()
1914	 * will flush this work
1915	 */
1916	async_schedule(do_scan_async, data);
1917
1918	/* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1919}
1920EXPORT_SYMBOL(scsi_scan_host);
1921
1922void scsi_forget_host(struct Scsi_Host *shost)
1923{
1924	struct scsi_device *sdev;
1925	unsigned long flags;
1926
1927 restart:
1928	spin_lock_irqsave(shost->host_lock, flags);
1929	list_for_each_entry(sdev, &shost->__devices, siblings) {
1930		if (sdev->sdev_state == SDEV_DEL)
1931			continue;
1932		spin_unlock_irqrestore(shost->host_lock, flags);
1933		__scsi_remove_device(sdev);
1934		goto restart;
1935	}
1936	spin_unlock_irqrestore(shost->host_lock, flags);
1937}
1938
1939/**
1940 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1941 * @shost: Host that needs a scsi_device
1942 *
1943 * Lock status: None assumed.
1944 *
1945 * Returns:     The scsi_device or NULL
1946 *
1947 * Notes:
1948 *	Attach a single scsi_device to the Scsi_Host - this should
1949 *	be made to look like a "pseudo-device" that points to the
1950 *	HA itself.
1951 *
1952 *	Note - this device is not accessible from any high-level
1953 *	drivers (including generics), which is probably not
1954 *	optimal.  We can add hooks later to attach.
1955 */
1956struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1957{
1958	struct scsi_device *sdev = NULL;
1959	struct scsi_target *starget;
1960
1961	mutex_lock(&shost->scan_mutex);
1962	if (!scsi_host_scan_allowed(shost))
1963		goto out;
1964	starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1965	if (!starget)
1966		goto out;
1967
1968	sdev = scsi_alloc_sdev(starget, 0, NULL);
1969	if (sdev)
1970		sdev->borken = 0;
1971	else
1972		scsi_target_reap(starget);
1973	put_device(&starget->dev);
1974 out:
1975	mutex_unlock(&shost->scan_mutex);
1976	return sdev;
1977}
1978EXPORT_SYMBOL(scsi_get_host_dev);
1979
1980/**
1981 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1982 * @sdev: Host device to be freed
1983 *
1984 * Lock status: None assumed.
1985 *
1986 * Returns:     Nothing
1987 */
1988void scsi_free_host_dev(struct scsi_device *sdev)
1989{
1990	BUG_ON(sdev->id != sdev->host->this_id);
1991
1992	__scsi_remove_device(sdev);
1993}
1994EXPORT_SYMBOL(scsi_free_host_dev);
1995