4 * Copyright (C) 2000 Eric Youngdale,
5 * Copyright (C) 2002 Patrick Mansfield
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.
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.
14 * For every id of every channel on the given host:
16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
17 * device or storage attached to LUN 0):
19 * If LUN 0 has a device attached, allocate and setup a
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.
28 #include <linux/config.h>
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/init.h>
32 #include <linux/blkdev.h>
33 #include <asm/semaphore.h>
35 #include <scsi/scsi.h>
36 #include <scsi/scsi_device.h>
37 #include <scsi/scsi_driver.h>
38 #include <scsi/scsi_devinfo.h>
39 #include <scsi/scsi_host.h>
40 #include <scsi/scsi_request.h>
41 #include <scsi/scsi_transport.h>
42 #include <scsi/scsi_eh.h>
44 #include "scsi_priv.h"
45 #include "scsi_logging.h"
47 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
48 " SCSI scanning, some SCSI devices might not be configured\n"
53 #define SCSI_TIMEOUT (2*HZ)
56 * Prefix values for the SCSI id's (stored in driverfs name field)
58 #define SCSI_UID_SER_NUM 'S'
59 #define SCSI_UID_UNKNOWN 'Z'
62 * Return values of some of the scanning functions.
64 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
65 * includes allocation or general failures preventing IO from being sent.
67 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
70 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
73 #define SCSI_SCAN_NO_RESPONSE 0
74 #define SCSI_SCAN_TARGET_PRESENT 1
75 #define SCSI_SCAN_LUN_PRESENT 2
77 static char *scsi_null_device_strs = "nullnullnullnull";
79 #define MAX_SCSI_LUNS 512
81 #ifdef CONFIG_SCSI_MULTI_LUN
82 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
84 static unsigned int max_scsi_luns = 1;
87 module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR);
88 MODULE_PARM_DESC(max_luns,
89 "last scsi LUN (should be between 1 and 2^32-1)");
92 * max_scsi_report_luns: the maximum number of LUNS that will be
93 * returned from the REPORT LUNS command. 8 times this value must
94 * be allocated. In theory this could be up to an 8 byte value, but
95 * in practice, the maximum number of LUNs suppored by any device
98 static unsigned int max_scsi_report_luns = 511;
100 module_param_named(max_report_luns, max_scsi_report_luns, int, S_IRUGO|S_IWUSR);
101 MODULE_PARM_DESC(max_report_luns,
102 "REPORT LUNS maximum number of LUNS received (should be"
103 " between 1 and 16384)");
105 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
107 module_param_named(inq_timeout, scsi_inq_timeout, int, S_IRUGO|S_IWUSR);
108 MODULE_PARM_DESC(inq_timeout,
109 "Timeout (in seconds) waiting for devices to answer INQUIRY."
110 " Default is 5. Some non-compliant devices need more.");
113 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
114 * @sdev: scsi device to send command to
115 * @result: area to store the result of the MODE SENSE
118 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
119 * Called for BLIST_KEY devices.
121 static void scsi_unlock_floptical(struct scsi_device *sdev,
122 unsigned char *result)
124 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
126 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
127 scsi_cmd[0] = MODE_SENSE;
131 scsi_cmd[4] = 0x2a; /* size */
133 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
138 * print_inquiry - printk the inquiry information
139 * @inq_result: printk this SCSI INQUIRY
142 * printk the vendor, model, and other information found in the
143 * INQUIRY data in @inq_result.
146 * Remove this, and replace with a hotplug event that logs any
147 * relevant information.
149 static void print_inquiry(unsigned char *inq_result)
153 printk(KERN_NOTICE " Vendor: ");
154 for (i = 8; i < 16; i++)
155 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
156 printk("%c", inq_result[i]);
161 for (i = 16; i < 32; i++)
162 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
163 printk("%c", inq_result[i]);
168 for (i = 32; i < 36; i++)
169 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
170 printk("%c", inq_result[i]);
176 i = inq_result[0] & 0x1f;
178 printk(KERN_NOTICE " Type: %s ",
180 MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] :
182 printk(" ANSI SCSI revision: %02x",
183 inq_result[2] & 0x07);
184 if ((inq_result[2] & 0x07) == 1 && (inq_result[3] & 0x0f) == 1)
191 * scsi_alloc_sdev - allocate and setup a scsi_Device
194 * Allocate, initialize for io, and return a pointer to a scsi_Device.
195 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
196 * adds scsi_Device to the appropriate list.
199 * scsi_Device pointer, or NULL on failure.
201 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
202 unsigned int lun, void *hostdata)
204 struct scsi_device *sdev;
205 int display_failure_msg = 1, ret;
206 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
208 sdev = kmalloc(sizeof(*sdev) + shost->transportt->device_size,
213 memset(sdev, 0, sizeof(*sdev));
214 sdev->vendor = scsi_null_device_strs;
215 sdev->model = scsi_null_device_strs;
216 sdev->rev = scsi_null_device_strs;
218 sdev->id = starget->id;
220 sdev->channel = starget->channel;
221 sdev->sdev_state = SDEV_CREATED;
222 INIT_LIST_HEAD(&sdev->siblings);
223 INIT_LIST_HEAD(&sdev->same_target_siblings);
224 INIT_LIST_HEAD(&sdev->cmd_list);
225 INIT_LIST_HEAD(&sdev->starved_entry);
226 spin_lock_init(&sdev->list_lock);
228 sdev->sdev_gendev.parent = get_device(&starget->dev);
229 sdev->sdev_target = starget;
231 /* usually NULL and set by ->slave_alloc instead */
232 sdev->hostdata = hostdata;
234 /* if the device needs this changing, it may do so in the
235 * slave_configure function */
236 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
239 * Some low level driver could use device->type
244 * Assume that the device will have handshaking problems,
245 * and then fix this field later if it turns out it
250 sdev->request_queue = scsi_alloc_queue(sdev);
251 if (!sdev->request_queue) {
252 /* release fn is set up in scsi_sysfs_device_initialise, so
253 * have to free and put manually here */
254 put_device(&starget->dev);
258 sdev->request_queue->queuedata = sdev;
259 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
261 scsi_sysfs_device_initialize(sdev);
263 if (shost->hostt->slave_alloc) {
264 ret = shost->hostt->slave_alloc(sdev);
267 * if LLDD reports slave not present, don't clutter
268 * console with alloc failure messages
273 display_failure_msg = 0;
274 goto out_device_destroy;
281 transport_destroy_device(&sdev->sdev_gendev);
282 put_device(&sdev->sdev_gendev);
284 if (display_failure_msg)
285 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
289 static void scsi_target_dev_release(struct device *dev)
291 struct device *parent = dev->parent;
292 struct scsi_target *starget = to_scsi_target(dev);
293 struct Scsi_Host *shost = dev_to_shost(parent);
295 if (shost->hostt->target_destroy)
296 shost->hostt->target_destroy(starget);
301 int scsi_is_target_device(const struct device *dev)
303 return dev->release == scsi_target_dev_release;
305 EXPORT_SYMBOL(scsi_is_target_device);
307 static struct scsi_target *__scsi_find_target(struct device *parent,
308 int channel, uint id)
310 struct scsi_target *starget, *found_starget = NULL;
311 struct Scsi_Host *shost = dev_to_shost(parent);
313 * Search for an existing target for this sdev.
315 list_for_each_entry(starget, &shost->__targets, siblings) {
316 if (starget->id == id &&
317 starget->channel == channel) {
318 found_starget = starget;
323 get_device(&found_starget->dev);
325 return found_starget;
328 static struct scsi_target *scsi_alloc_target(struct device *parent,
329 int channel, uint id)
331 struct Scsi_Host *shost = dev_to_shost(parent);
332 struct device *dev = NULL;
334 const int size = sizeof(struct scsi_target)
335 + shost->transportt->target_size;
336 struct scsi_target *starget;
337 struct scsi_target *found_target;
340 * Obtain the real parent from the transport. The transport
341 * is allowed to fail (no error) if there is nothing at that
344 if (shost->transportt->target_parent) {
345 spin_lock_irqsave(shost->host_lock, flags);
346 parent = shost->transportt->target_parent(shost, channel, id);
347 spin_unlock_irqrestore(shost->host_lock, flags);
352 starget = kmalloc(size, GFP_KERNEL);
354 printk(KERN_ERR "%s: allocation failure\n", __FUNCTION__);
357 memset(starget, 0, size);
359 device_initialize(dev);
360 starget->reap_ref = 1;
361 dev->parent = get_device(parent);
362 dev->release = scsi_target_dev_release;
363 sprintf(dev->bus_id, "target%d:%d:%d",
364 shost->host_no, channel, id);
366 starget->channel = channel;
367 INIT_LIST_HEAD(&starget->siblings);
368 INIT_LIST_HEAD(&starget->devices);
369 spin_lock_irqsave(shost->host_lock, flags);
371 found_target = __scsi_find_target(parent, channel, id);
375 list_add_tail(&starget->siblings, &shost->__targets);
376 spin_unlock_irqrestore(shost->host_lock, flags);
377 /* allocate and add */
378 transport_setup_device(dev);
380 transport_add_device(dev);
381 if (shost->hostt->target_alloc) {
382 int error = shost->hostt->target_alloc(starget);
385 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
386 /* don't want scsi_target_reap to do the final
387 * put because it will be under the host lock */
389 scsi_target_reap(starget);
398 found_target->reap_ref++;
399 spin_unlock_irqrestore(shost->host_lock, flags);
406 * scsi_target_reap - check to see if target is in use and destroy if not
408 * @starget: target to be checked
410 * This is used after removing a LUN or doing a last put of the target
411 * it checks atomically that nothing is using the target and removes
414 void scsi_target_reap(struct scsi_target *starget)
416 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
418 spin_lock_irqsave(shost->host_lock, flags);
420 if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
421 list_del_init(&starget->siblings);
422 spin_unlock_irqrestore(shost->host_lock, flags);
423 device_del(&starget->dev);
424 transport_unregister_device(&starget->dev);
425 put_device(&starget->dev);
428 spin_unlock_irqrestore(shost->host_lock, flags);
432 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
433 * @sdev: scsi_device to probe
434 * @inq_result: area to store the INQUIRY result
435 * @result_len: len of inq_result
436 * @bflags: store any bflags found here
439 * Probe the lun associated with @req using a standard SCSI INQUIRY;
441 * If the INQUIRY is successful, zero is returned and the
442 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
443 * are copied to the scsi_device any flags value is stored in *@bflags.
445 static int scsi_probe_lun(struct scsi_device *sdev, char *inq_result,
446 int result_len, int *bflags)
448 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
449 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
450 int response_len = 0;
451 int pass, count, result;
452 struct scsi_sense_hdr sshdr;
456 /* Perform up to 3 passes. The first pass uses a conservative
457 * transfer length of 36 unless sdev->inquiry_len specifies a
458 * different value. */
459 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
460 try_inquiry_len = first_inquiry_len;
464 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
465 "scsi scan: INQUIRY pass %d length %d\n",
466 pass, try_inquiry_len));
468 /* Each pass gets up to three chances to ignore Unit Attention */
469 for (count = 0; count < 3; ++count) {
470 memset(scsi_cmd, 0, 6);
471 scsi_cmd[0] = INQUIRY;
472 scsi_cmd[4] = (unsigned char) try_inquiry_len;
474 memset(inq_result, 0, try_inquiry_len);
476 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
477 inq_result, try_inquiry_len, &sshdr,
478 HZ / 2 + HZ * scsi_inq_timeout, 3);
480 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
482 result ? "failed" : "successful", result));
486 * not-ready to ready transition [asc/ascq=0x28/0x0]
487 * or power-on, reset [asc/ascq=0x29/0x0], continue.
488 * INQUIRY should not yield UNIT_ATTENTION
489 * but many buggy devices do so anyway.
491 if ((driver_byte(result) & DRIVER_SENSE) &&
492 scsi_sense_valid(&sshdr)) {
493 if ((sshdr.sense_key == UNIT_ATTENTION) &&
494 ((sshdr.asc == 0x28) ||
495 (sshdr.asc == 0x29)) &&
504 response_len = (unsigned char) inq_result[4] + 5;
505 if (response_len > 255)
506 response_len = first_inquiry_len; /* sanity */
509 * Get any flags for this device.
511 * XXX add a bflags to scsi_device, and replace the
512 * corresponding bit fields in scsi_device, so bflags
513 * need not be passed as an argument.
515 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
518 /* When the first pass succeeds we gain information about
519 * what larger transfer lengths might work. */
521 if (BLIST_INQUIRY_36 & *bflags)
522 next_inquiry_len = 36;
523 else if (BLIST_INQUIRY_58 & *bflags)
524 next_inquiry_len = 58;
525 else if (sdev->inquiry_len)
526 next_inquiry_len = sdev->inquiry_len;
528 next_inquiry_len = response_len;
530 /* If more data is available perform the second pass */
531 if (next_inquiry_len > try_inquiry_len) {
532 try_inquiry_len = next_inquiry_len;
538 } else if (pass == 2) {
539 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
540 "Consider BLIST_INQUIRY_36 for this device\n",
543 /* If this pass failed, the third pass goes back and transfers
544 * the same amount as we successfully got in the first pass. */
545 try_inquiry_len = first_inquiry_len;
550 /* If the last transfer attempt got an error, assume the
551 * peripheral doesn't exist or is dead. */
555 /* Don't report any more data than the device says is valid */
556 sdev->inquiry_len = min(try_inquiry_len, response_len);
559 * XXX Abort if the response length is less than 36? If less than
560 * 32, the lookup of the device flags (above) could be invalid,
561 * and it would be possible to take an incorrect action - we do
562 * not want to hang because of a short INQUIRY. On the flip side,
563 * if the device is spun down or becoming ready (and so it gives a
564 * short INQUIRY), an abort here prevents any further use of the
565 * device, including spin up.
567 * Related to the above issue:
569 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
570 * and if not ready, sent a START_STOP to start (maybe spin up) and
571 * then send the INQUIRY again, since the INQUIRY can change after
572 * a device is initialized.
574 * Ideally, start a device if explicitly asked to do so. This
575 * assumes that a device is spun up on power on, spun down on
576 * request, and then spun up on request.
580 * The scanning code needs to know the scsi_level, even if no
581 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
582 * non-zero LUNs can be scanned.
584 sdev->scsi_level = inq_result[2] & 0x07;
585 if (sdev->scsi_level >= 2 ||
586 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
588 sdev->sdev_target->scsi_level = sdev->scsi_level;
594 * scsi_add_lun - allocate and fully initialze a scsi_device
595 * @sdevscan: holds information to be stored in the new scsi_device
596 * @sdevnew: store the address of the newly allocated scsi_device
597 * @inq_result: holds the result of a previous INQUIRY to the LUN
598 * @bflags: black/white list flag
601 * Allocate and initialize a scsi_device matching sdevscan. Optionally
602 * set fields based on values in *@bflags. If @sdevnew is not
603 * NULL, store the address of the new scsi_device in *@sdevnew (needed
604 * when scanning a particular LUN).
607 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
608 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
610 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
613 * XXX do not save the inquiry, since it can change underneath us,
614 * save just vendor/model/rev.
616 * Rather than save it and have an ioctl that retrieves the saved
617 * value, have an ioctl that executes the same INQUIRY code used
618 * in scsi_probe_lun, let user level programs doing INQUIRY
619 * scanning run at their own risk, or supply a user level program
620 * that can correctly scan.
622 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
623 if (sdev->inquiry == NULL) {
624 return SCSI_SCAN_NO_RESPONSE;
627 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
628 sdev->vendor = (char *) (sdev->inquiry + 8);
629 sdev->model = (char *) (sdev->inquiry + 16);
630 sdev->rev = (char *) (sdev->inquiry + 32);
632 if (*bflags & BLIST_ISROM) {
634 * It would be better to modify sdev->type, and set
635 * sdev->removable, but then the print_inquiry() output
636 * would not show TYPE_ROM; if print_inquiry() is removed
637 * the issue goes away.
639 inq_result[0] = TYPE_ROM;
640 inq_result[1] |= 0x80; /* removable */
641 } else if (*bflags & BLIST_NO_ULD_ATTACH)
642 sdev->no_uld_attach = 1;
644 switch (sdev->type = (inq_result[0] & 0x1f)) {
651 case TYPE_MEDIUM_CHANGER:
662 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
665 print_inquiry(inq_result);
668 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
669 * spec says: The device server is capable of supporting the
670 * specified peripheral device type on this logical unit. However,
671 * the physical device is not currently connected to this logical
674 * The above is vague, as it implies that we could treat 001 and
675 * 011 the same. Stay compatible with previous code, and create a
676 * scsi_device for a PQ of 1
678 * Don't set the device offline here; rather let the upper
679 * level drivers eval the PQ to decide whether they should
680 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
683 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
684 sdev->removable = (0x80 & inq_result[1]) >> 7;
685 sdev->lockable = sdev->removable;
686 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
688 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
689 inq_result[56] & 0x04))
691 if (inq_result[7] & 0x60)
693 if (inq_result[7] & 0x10)
696 sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
697 sdev->host->host_no, sdev->channel,
698 sdev->id, sdev->lun);
701 * End driverfs/devfs code.
704 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
705 !(*bflags & BLIST_NOTQ))
706 sdev->tagged_supported = 1;
708 * Some devices (Texel CD ROM drives) have handshaking problems
709 * when used with the Seagate controllers. borken is initialized
710 * to 1, and then set it to 0 here.
712 if ((*bflags & BLIST_BORKEN) == 0)
716 * Apparently some really broken devices (contrary to the SCSI
717 * standards) need to be selected without asserting ATN
719 if (*bflags & BLIST_SELECT_NO_ATN)
720 sdev->select_no_atn = 1;
723 * Some devices may not want to have a start command automatically
724 * issued when a device is added.
726 if (*bflags & BLIST_NOSTARTONADD)
727 sdev->no_start_on_add = 1;
729 if (*bflags & BLIST_SINGLELUN)
730 sdev->single_lun = 1;
733 sdev->use_10_for_rw = 1;
735 if (*bflags & BLIST_MS_SKIP_PAGE_08)
736 sdev->skip_ms_page_8 = 1;
738 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
739 sdev->skip_ms_page_3f = 1;
741 if (*bflags & BLIST_USE_10_BYTE_MS)
742 sdev->use_10_for_ms = 1;
744 /* set the device running here so that slave configure
746 scsi_device_set_state(sdev, SDEV_RUNNING);
748 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
749 sdev->use_192_bytes_for_3f = 1;
751 if (*bflags & BLIST_NOT_LOCKABLE)
754 if (*bflags & BLIST_RETRY_HWERROR)
755 sdev->retry_hwerror = 1;
757 transport_configure_device(&sdev->sdev_gendev);
759 if (sdev->host->hostt->slave_configure)
760 sdev->host->hostt->slave_configure(sdev);
763 * Ok, the device is now all set up, we can
764 * register it and tell the rest of the kernel
767 if (scsi_sysfs_add_sdev(sdev) != 0)
768 return SCSI_SCAN_NO_RESPONSE;
770 return SCSI_SCAN_LUN_PRESENT;
773 static inline void scsi_destroy_sdev(struct scsi_device *sdev)
775 if (sdev->host->hostt->slave_destroy)
776 sdev->host->hostt->slave_destroy(sdev);
777 transport_destroy_device(&sdev->sdev_gendev);
778 put_device(&sdev->sdev_gendev);
783 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
784 * @starget: pointer to target device structure
785 * @lun: LUN of target device
786 * @sdevscan: probe the LUN corresponding to this scsi_device
787 * @sdevnew: store the value of any new scsi_device allocated
788 * @bflagsp: store bflags here if not NULL
791 * Call scsi_probe_lun, if a LUN with an attached device is found,
792 * allocate and set it up by calling scsi_add_lun.
795 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
796 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
797 * attached at the LUN
798 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
800 static int scsi_probe_and_add_lun(struct scsi_target *starget,
801 uint lun, int *bflagsp,
802 struct scsi_device **sdevp, int rescan,
805 struct scsi_device *sdev;
806 unsigned char *result;
807 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
808 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
811 * The rescan flag is used as an optimization, the first scan of a
812 * host adapter calls into here with rescan == 0.
814 sdev = scsi_device_lookup_by_target(starget, lun);
816 if (rescan || sdev->sdev_state != SDEV_CREATED) {
817 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
818 "scsi scan: device exists on %s\n",
819 sdev->sdev_gendev.bus_id));
823 scsi_device_put(sdev);
826 *bflagsp = scsi_get_device_flags(sdev,
829 return SCSI_SCAN_LUN_PRESENT;
831 scsi_device_put(sdev);
833 sdev = scsi_alloc_sdev(starget, lun, hostdata);
837 result = kmalloc(result_len, GFP_ATOMIC |
838 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
842 if (scsi_probe_lun(sdev, result, result_len, &bflags))
843 goto out_free_result;
846 * result contains valid SCSI INQUIRY data.
848 if ((result[0] >> 5) == 3) {
850 * For a Peripheral qualifier 3 (011b), the SCSI
851 * spec says: The device server is not capable of
852 * supporting a physical device on this logical
855 * For disks, this implies that there is no
856 * logical disk configured at sdev->lun, but there
857 * is a target id responding.
859 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
860 "scsi scan: peripheral qualifier of 3,"
861 " no device added\n"));
862 res = SCSI_SCAN_TARGET_PRESENT;
863 goto out_free_result;
866 res = scsi_add_lun(sdev, result, &bflags);
867 if (res == SCSI_SCAN_LUN_PRESENT) {
868 if (bflags & BLIST_KEY) {
870 scsi_unlock_floptical(sdev, result);
879 if (res == SCSI_SCAN_LUN_PRESENT) {
881 if (scsi_device_get(sdev) == 0) {
884 __scsi_remove_device(sdev);
885 res = SCSI_SCAN_NO_RESPONSE;
889 scsi_destroy_sdev(sdev);
895 * scsi_sequential_lun_scan - sequentially scan a SCSI target
896 * @starget: pointer to target structure to scan
897 * @bflags: black/white list flag for LUN 0
898 * @lun0_res: result of scanning LUN 0
901 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
902 * scanned) to some maximum lun until a LUN is found with no device
903 * attached. Use the bflags to figure out any oddities.
905 * Modifies sdevscan->lun.
907 static void scsi_sequential_lun_scan(struct scsi_target *starget,
908 int bflags, int lun0_res, int scsi_level,
911 unsigned int sparse_lun, lun, max_dev_lun;
912 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
914 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
915 "%s\n", starget->dev.bus_id));
917 max_dev_lun = min(max_scsi_luns, shost->max_lun);
919 * If this device is known to support sparse multiple units,
920 * override the other settings, and scan all of them. Normally,
921 * SCSI-3 devices should be scanned via the REPORT LUNS.
923 if (bflags & BLIST_SPARSELUN) {
924 max_dev_lun = shost->max_lun;
930 * If not sparse lun and no device attached at LUN 0 do not scan
933 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
937 * If less than SCSI_1_CSS, and no special lun scaning, stop
938 * scanning; this matches 2.4 behaviour, but could just be a bug
939 * (to continue scanning a SCSI_1_CSS device).
941 * This test is broken. We might not have any device on lun0 for
942 * a sparselun device, and if that's the case then how would we
943 * know the real scsi_level, eh? It might make sense to just not
944 * scan any SCSI_1 device for non-0 luns, but that check would best
945 * go into scsi_alloc_sdev() and just have it return null when asked
946 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
948 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
949 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
954 * If this device is known to support multiple units, override
955 * the other settings, and scan all of them.
957 if (bflags & BLIST_FORCELUN)
958 max_dev_lun = shost->max_lun;
960 * REGAL CDC-4X: avoid hang after LUN 4
962 if (bflags & BLIST_MAX5LUN)
963 max_dev_lun = min(5U, max_dev_lun);
965 * Do not scan SCSI-2 or lower device past LUN 7, unless
968 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
969 max_dev_lun = min(8U, max_dev_lun);
972 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
973 * until we reach the max, or no LUN is found and we are not
976 for (lun = 1; lun < max_dev_lun; ++lun)
977 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
978 NULL) != SCSI_SCAN_LUN_PRESENT) &&
984 * scsilun_to_int: convert a scsi_lun to an int
985 * @scsilun: struct scsi_lun to be converted.
988 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
989 * integer, and return the result. The caller must check for
990 * truncation before using this function.
993 * The struct scsi_lun is assumed to be four levels, with each level
994 * effectively containing a SCSI byte-ordered (big endian) short; the
995 * addressing bits of each level are ignored (the highest two bits).
996 * For a description of the LUN format, post SCSI-3 see the SCSI
997 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
999 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1000 * the integer: 0x0b030a04
1002 static int scsilun_to_int(struct scsi_lun *scsilun)
1008 for (i = 0; i < sizeof(lun); i += 2)
1009 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1010 scsilun->scsi_lun[i + 1]) << (i * 8));
1015 * int_to_scsilun: reverts an int into a scsi_lun
1016 * @int: integer to be reverted
1017 * @scsilun: struct scsi_lun to be set.
1020 * Reverts the functionality of the scsilun_to_int, which packed
1021 * an 8-byte lun value into an int. This routine unpacks the int
1022 * back into the lun value.
1023 * Note: the scsilun_to_int() routine does not truly handle all
1024 * 8bytes of the lun value. This functions restores only as much
1025 * as was set by the routine.
1028 * Given an integer : 0x0b030a04, this function returns a
1029 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1032 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1036 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1038 for (i = 0; i < sizeof(lun); i += 2) {
1039 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1040 scsilun->scsi_lun[i+1] = lun & 0xFF;
1044 EXPORT_SYMBOL(int_to_scsilun);
1047 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1048 * @sdevscan: scan the host, channel, and id of this scsi_device
1051 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
1052 * command, and scan the resulting list of LUNs by calling
1053 * scsi_probe_and_add_lun.
1055 * Modifies sdevscan->lun.
1058 * 0: scan completed (or no memory, so further scanning is futile)
1059 * 1: no report lun scan, or not configured
1061 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1065 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1066 unsigned int length;
1068 unsigned int num_luns;
1069 unsigned int retries;
1071 struct scsi_lun *lunp, *lun_data;
1073 struct scsi_sense_hdr sshdr;
1074 struct scsi_device *sdev;
1075 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1079 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1080 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1081 * support more than 8 LUNs.
1083 if ((bflags & BLIST_NOREPORTLUN) ||
1084 starget->scsi_level < SCSI_2 ||
1085 (starget->scsi_level < SCSI_3 &&
1086 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) )
1088 if (bflags & BLIST_NOLUN)
1091 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1092 sdev = scsi_alloc_sdev(starget, 0, NULL);
1095 if (scsi_device_get(sdev))
1099 sprintf(devname, "host %d channel %d id %d",
1100 shost->host_no, sdev->channel, sdev->id);
1103 * Allocate enough to hold the header (the same size as one scsi_lun)
1104 * plus the max number of luns we are requesting.
1106 * Reallocating and trying again (with the exact amount we need)
1107 * would be nice, but then we need to somehow limit the size
1108 * allocated based on the available memory and the limits of
1109 * kmalloc - we don't want a kmalloc() failure of a huge value to
1110 * prevent us from finding any LUNs on this target.
1112 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1113 lun_data = kmalloc(length, GFP_ATOMIC |
1114 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1116 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1120 scsi_cmd[0] = REPORT_LUNS;
1123 * bytes 1 - 5: reserved, set to zero.
1125 memset(&scsi_cmd[1], 0, 5);
1128 * bytes 6 - 9: length of the command.
1130 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1131 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1132 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1133 scsi_cmd[9] = (unsigned char) length & 0xff;
1135 scsi_cmd[10] = 0; /* reserved */
1136 scsi_cmd[11] = 0; /* control */
1139 * We can get a UNIT ATTENTION, for example a power on/reset, so
1140 * retry a few times (like sd.c does for TEST UNIT READY).
1141 * Experience shows some combinations of adapter/devices get at
1142 * least two power on/resets.
1144 * Illegal requests (for devices that do not support REPORT LUNS)
1145 * should come through as a check condition, and will not generate
1148 for (retries = 0; retries < 3; retries++) {
1149 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1150 " REPORT LUNS to %s (try %d)\n", devname,
1153 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1154 lun_data, length, &sshdr,
1155 SCSI_TIMEOUT + 4 * HZ, 3);
1157 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1158 " %s (try %d) result 0x%x\n", result
1159 ? "failed" : "successful", retries, result));
1162 else if (scsi_sense_valid(&sshdr)) {
1163 if (sshdr.sense_key != UNIT_ATTENTION)
1170 * The device probably does not support a REPORT LUN command
1177 * Get the length from the first four bytes of lun_data.
1179 data = (u8 *) lun_data->scsi_lun;
1180 length = ((data[0] << 24) | (data[1] << 16) |
1181 (data[2] << 8) | (data[3] << 0));
1183 num_luns = (length / sizeof(struct scsi_lun));
1184 if (num_luns > max_scsi_report_luns) {
1185 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1186 " of %d luns reported, try increasing"
1187 " max_scsi_report_luns.\n", devname,
1188 max_scsi_report_luns, num_luns);
1189 num_luns = max_scsi_report_luns;
1192 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1193 "scsi scan: REPORT LUN scan\n"));
1196 * Scan the luns in lun_data. The entry at offset 0 is really
1197 * the header, so start at 1 and go up to and including num_luns.
1199 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1200 lun = scsilun_to_int(lunp);
1203 * Check if the unused part of lunp is non-zero, and so
1204 * does not fit in lun.
1206 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1210 * Output an error displaying the LUN in byte order,
1211 * this differs from what linux would print for the
1212 * integer LUN value.
1214 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1215 data = (char *)lunp->scsi_lun;
1216 for (i = 0; i < sizeof(struct scsi_lun); i++)
1217 printk("%02x", data[i]);
1218 printk(" has a LUN larger than currently supported.\n");
1219 } else if (lun > sdev->host->max_lun) {
1220 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1221 " than allowed by the host adapter\n",
1226 res = scsi_probe_and_add_lun(starget,
1227 lun, NULL, NULL, rescan, NULL);
1228 if (res == SCSI_SCAN_NO_RESPONSE) {
1230 * Got some results, but now none, abort.
1232 sdev_printk(KERN_ERR, sdev,
1233 "Unexpected response"
1234 " from lun %d while scanning, scan"
1244 scsi_device_put(sdev);
1245 if (sdev->sdev_state == SDEV_CREATED)
1247 * the sdev we used didn't appear in the report luns scan
1249 scsi_destroy_sdev(sdev);
1253 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1254 uint id, uint lun, void *hostdata)
1256 struct scsi_device *sdev;
1257 struct device *parent = &shost->shost_gendev;
1259 struct scsi_target *starget = scsi_alloc_target(parent, channel, id);
1262 return ERR_PTR(-ENOMEM);
1264 get_device(&starget->dev);
1265 down(&shost->scan_mutex);
1266 if (scsi_host_scan_allowed(shost)) {
1267 res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1,
1269 if (res != SCSI_SCAN_LUN_PRESENT)
1270 sdev = ERR_PTR(-ENODEV);
1272 up(&shost->scan_mutex);
1273 scsi_target_reap(starget);
1274 put_device(&starget->dev);
1278 EXPORT_SYMBOL(__scsi_add_device);
1280 int scsi_add_device(struct Scsi_Host *host, uint channel,
1281 uint target, uint lun)
1283 struct scsi_device *sdev =
1284 __scsi_add_device(host, channel, target, lun, NULL);
1286 return PTR_ERR(sdev);
1288 scsi_device_put(sdev);
1291 EXPORT_SYMBOL(scsi_add_device);
1293 void scsi_rescan_device(struct device *dev)
1295 struct scsi_driver *drv;
1300 drv = to_scsi_driver(dev->driver);
1301 if (try_module_get(drv->owner)) {
1304 module_put(drv->owner);
1307 EXPORT_SYMBOL(scsi_rescan_device);
1309 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1310 unsigned int id, unsigned int lun, int rescan)
1312 struct Scsi_Host *shost = dev_to_shost(parent);
1315 struct scsi_target *starget;
1317 if (shost->this_id == id)
1319 * Don't scan the host adapter
1323 starget = scsi_alloc_target(parent, channel, id);
1327 get_device(&starget->dev);
1328 if (lun != SCAN_WILD_CARD) {
1330 * Scan for a specific host/chan/id/lun.
1332 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1337 * Scan LUN 0, if there is some response, scan further. Ideally, we
1338 * would not configure LUN 0 until all LUNs are scanned.
1340 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1341 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1342 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1344 * The REPORT LUN did not scan the target,
1345 * do a sequential scan.
1347 scsi_sequential_lun_scan(starget, bflags,
1348 res, starget->scsi_level, rescan);
1352 /* now determine if the target has any children at all
1353 * and if not, nuke it */
1354 scsi_target_reap(starget);
1356 put_device(&starget->dev);
1360 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1362 * @parent: host to scan
1363 * @channel: channel to scan
1364 * @id: target id to scan
1365 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1366 * @rescan: passed to LUN scanning routines
1369 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1370 * and possibly all LUNs on the target id.
1372 * First try a REPORT LUN scan, if that does not scan the target, do a
1373 * sequential scan of LUNs on the target id.
1375 void scsi_scan_target(struct device *parent, unsigned int channel,
1376 unsigned int id, unsigned int lun, int rescan)
1378 struct Scsi_Host *shost = dev_to_shost(parent);
1380 down(&shost->scan_mutex);
1381 if (scsi_host_scan_allowed(shost))
1382 __scsi_scan_target(parent, channel, id, lun, rescan);
1383 up(&shost->scan_mutex);
1385 EXPORT_SYMBOL(scsi_scan_target);
1387 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1388 unsigned int id, unsigned int lun, int rescan)
1392 if (id == SCAN_WILD_CARD)
1393 for (id = 0; id < shost->max_id; ++id) {
1395 * XXX adapter drivers when possible (FCP, iSCSI)
1396 * could modify max_id to match the current max,
1397 * not the absolute max.
1399 * XXX add a shost id iterator, so for example,
1400 * the FC ID can be the same as a target id
1401 * without a huge overhead of sparse id's.
1403 if (shost->reverse_ordering)
1405 * Scan from high to low id.
1407 order_id = shost->max_id - id - 1;
1410 __scsi_scan_target(&shost->shost_gendev, channel,
1411 order_id, lun, rescan);
1414 __scsi_scan_target(&shost->shost_gendev, channel,
1418 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1419 unsigned int id, unsigned int lun, int rescan)
1421 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1423 __FUNCTION__, channel, id, lun));
1425 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1426 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1427 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1430 down(&shost->scan_mutex);
1431 if (scsi_host_scan_allowed(shost)) {
1432 if (channel == SCAN_WILD_CARD)
1433 for (channel = 0; channel <= shost->max_channel;
1435 scsi_scan_channel(shost, channel, id, lun,
1438 scsi_scan_channel(shost, channel, id, lun, rescan);
1440 up(&shost->scan_mutex);
1446 * scsi_scan_host - scan the given adapter
1447 * @shost: adapter to scan
1449 void scsi_scan_host(struct Scsi_Host *shost)
1451 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1454 EXPORT_SYMBOL(scsi_scan_host);
1456 void scsi_forget_host(struct Scsi_Host *shost)
1458 struct scsi_device *sdev;
1459 unsigned long flags;
1462 spin_lock_irqsave(shost->host_lock, flags);
1463 list_for_each_entry(sdev, &shost->__devices, siblings) {
1464 if (sdev->sdev_state == SDEV_DEL)
1466 spin_unlock_irqrestore(shost->host_lock, flags);
1467 __scsi_remove_device(sdev);
1470 spin_unlock_irqrestore(shost->host_lock, flags);
1474 * Function: scsi_get_host_dev()
1476 * Purpose: Create a scsi_device that points to the host adapter itself.
1478 * Arguments: SHpnt - Host that needs a scsi_device
1480 * Lock status: None assumed.
1482 * Returns: The scsi_device or NULL
1485 * Attach a single scsi_device to the Scsi_Host - this should
1486 * be made to look like a "pseudo-device" that points to the
1489 * Note - this device is not accessible from any high-level
1490 * drivers (including generics), which is probably not
1491 * optimal. We can add hooks later to attach
1493 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1495 struct scsi_device *sdev = NULL;
1496 struct scsi_target *starget;
1498 down(&shost->scan_mutex);
1499 if (!scsi_host_scan_allowed(shost))
1501 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1505 sdev = scsi_alloc_sdev(starget, 0, NULL);
1507 sdev->sdev_gendev.parent = get_device(&starget->dev);
1510 put_device(&starget->dev);
1512 up(&shost->scan_mutex);
1515 EXPORT_SYMBOL(scsi_get_host_dev);
1518 * Function: scsi_free_host_dev()
1520 * Purpose: Free a scsi_device that points to the host adapter itself.
1522 * Arguments: SHpnt - Host that needs a scsi_device
1524 * Lock status: None assumed.
1530 void scsi_free_host_dev(struct scsi_device *sdev)
1532 BUG_ON(sdev->id != sdev->host->this_id);
1534 scsi_destroy_sdev(sdev);
1536 EXPORT_SYMBOL(scsi_free_host_dev);