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 const 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 = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
213 sdev->vendor = scsi_null_device_strs;
214 sdev->model = scsi_null_device_strs;
215 sdev->rev = scsi_null_device_strs;
217 sdev->id = starget->id;
219 sdev->channel = starget->channel;
220 sdev->sdev_state = SDEV_CREATED;
221 INIT_LIST_HEAD(&sdev->siblings);
222 INIT_LIST_HEAD(&sdev->same_target_siblings);
223 INIT_LIST_HEAD(&sdev->cmd_list);
224 INIT_LIST_HEAD(&sdev->starved_entry);
225 spin_lock_init(&sdev->list_lock);
227 sdev->sdev_gendev.parent = get_device(&starget->dev);
228 sdev->sdev_target = starget;
230 /* usually NULL and set by ->slave_alloc instead */
231 sdev->hostdata = hostdata;
233 /* if the device needs this changing, it may do so in the
234 * slave_configure function */
235 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
238 * Some low level driver could use device->type
243 * Assume that the device will have handshaking problems,
244 * and then fix this field later if it turns out it
249 sdev->request_queue = scsi_alloc_queue(sdev);
250 if (!sdev->request_queue) {
251 /* release fn is set up in scsi_sysfs_device_initialise, so
252 * have to free and put manually here */
253 put_device(&starget->dev);
257 sdev->request_queue->queuedata = sdev;
258 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
260 scsi_sysfs_device_initialize(sdev);
262 if (shost->hostt->slave_alloc) {
263 ret = shost->hostt->slave_alloc(sdev);
266 * if LLDD reports slave not present, don't clutter
267 * console with alloc failure messages
270 display_failure_msg = 0;
271 goto out_device_destroy;
278 transport_destroy_device(&sdev->sdev_gendev);
279 put_device(&sdev->sdev_gendev);
281 if (display_failure_msg)
282 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
286 static void scsi_target_dev_release(struct device *dev)
288 struct device *parent = dev->parent;
289 struct scsi_target *starget = to_scsi_target(dev);
290 struct Scsi_Host *shost = dev_to_shost(parent);
292 if (shost->hostt->target_destroy)
293 shost->hostt->target_destroy(starget);
298 int scsi_is_target_device(const struct device *dev)
300 return dev->release == scsi_target_dev_release;
302 EXPORT_SYMBOL(scsi_is_target_device);
304 static struct scsi_target *__scsi_find_target(struct device *parent,
305 int channel, uint id)
307 struct scsi_target *starget, *found_starget = NULL;
308 struct Scsi_Host *shost = dev_to_shost(parent);
310 * Search for an existing target for this sdev.
312 list_for_each_entry(starget, &shost->__targets, siblings) {
313 if (starget->id == id &&
314 starget->channel == channel) {
315 found_starget = starget;
320 get_device(&found_starget->dev);
322 return found_starget;
325 static struct scsi_target *scsi_alloc_target(struct device *parent,
326 int channel, uint id)
328 struct Scsi_Host *shost = dev_to_shost(parent);
329 struct device *dev = NULL;
331 const int size = sizeof(struct scsi_target)
332 + shost->transportt->target_size;
333 struct scsi_target *starget;
334 struct scsi_target *found_target;
336 starget = kzalloc(size, GFP_KERNEL);
338 printk(KERN_ERR "%s: allocation failure\n", __FUNCTION__);
342 device_initialize(dev);
343 starget->reap_ref = 1;
344 dev->parent = get_device(parent);
345 dev->release = scsi_target_dev_release;
346 sprintf(dev->bus_id, "target%d:%d:%d",
347 shost->host_no, channel, id);
349 starget->channel = channel;
350 INIT_LIST_HEAD(&starget->siblings);
351 INIT_LIST_HEAD(&starget->devices);
352 starget->state = STARGET_RUNNING;
354 spin_lock_irqsave(shost->host_lock, flags);
356 found_target = __scsi_find_target(parent, channel, id);
360 list_add_tail(&starget->siblings, &shost->__targets);
361 spin_unlock_irqrestore(shost->host_lock, flags);
362 /* allocate and add */
363 transport_setup_device(dev);
365 transport_add_device(dev);
366 if (shost->hostt->target_alloc) {
367 int error = shost->hostt->target_alloc(starget);
370 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
371 /* don't want scsi_target_reap to do the final
372 * put because it will be under the host lock */
374 scsi_target_reap(starget);
383 found_target->reap_ref++;
384 spin_unlock_irqrestore(shost->host_lock, flags);
386 if (found_target->state != STARGET_DEL) {
390 /* Unfortunately, we found a dying target; need to
391 * wait until it's dead before we can get a new one */
392 put_device(&found_target->dev);
393 flush_scheduled_work();
397 static void scsi_target_reap_usercontext(void *data)
399 struct scsi_target *starget = data;
400 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
403 transport_remove_device(&starget->dev);
404 device_del(&starget->dev);
405 transport_destroy_device(&starget->dev);
406 spin_lock_irqsave(shost->host_lock, flags);
407 list_del_init(&starget->siblings);
408 spin_unlock_irqrestore(shost->host_lock, flags);
409 put_device(&starget->dev);
413 * scsi_target_reap - check to see if target is in use and destroy if not
415 * @starget: target to be checked
417 * This is used after removing a LUN or doing a last put of the target
418 * it checks atomically that nothing is using the target and removes
421 void scsi_target_reap(struct scsi_target *starget)
423 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
426 spin_lock_irqsave(shost->host_lock, flags);
428 if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
429 BUG_ON(starget->state == STARGET_DEL);
430 starget->state = STARGET_DEL;
431 spin_unlock_irqrestore(shost->host_lock, flags);
432 execute_in_process_context(scsi_target_reap_usercontext,
433 starget, &starget->ew);
437 spin_unlock_irqrestore(shost->host_lock, flags);
443 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
444 * @sdev: scsi_device to probe
445 * @inq_result: area to store the INQUIRY result
446 * @result_len: len of inq_result
447 * @bflags: store any bflags found here
450 * Probe the lun associated with @req using a standard SCSI INQUIRY;
452 * If the INQUIRY is successful, zero is returned and the
453 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
454 * are copied to the scsi_device any flags value is stored in *@bflags.
456 static int scsi_probe_lun(struct scsi_device *sdev, char *inq_result,
457 int result_len, int *bflags)
459 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
460 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
461 int response_len = 0;
462 int pass, count, result;
463 struct scsi_sense_hdr sshdr;
467 /* Perform up to 3 passes. The first pass uses a conservative
468 * transfer length of 36 unless sdev->inquiry_len specifies a
469 * different value. */
470 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
471 try_inquiry_len = first_inquiry_len;
475 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
476 "scsi scan: INQUIRY pass %d length %d\n",
477 pass, try_inquiry_len));
479 /* Each pass gets up to three chances to ignore Unit Attention */
480 for (count = 0; count < 3; ++count) {
481 memset(scsi_cmd, 0, 6);
482 scsi_cmd[0] = INQUIRY;
483 scsi_cmd[4] = (unsigned char) try_inquiry_len;
485 memset(inq_result, 0, try_inquiry_len);
487 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
488 inq_result, try_inquiry_len, &sshdr,
489 HZ / 2 + HZ * scsi_inq_timeout, 3);
491 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
493 result ? "failed" : "successful", result));
497 * not-ready to ready transition [asc/ascq=0x28/0x0]
498 * or power-on, reset [asc/ascq=0x29/0x0], continue.
499 * INQUIRY should not yield UNIT_ATTENTION
500 * but many buggy devices do so anyway.
502 if ((driver_byte(result) & DRIVER_SENSE) &&
503 scsi_sense_valid(&sshdr)) {
504 if ((sshdr.sense_key == UNIT_ATTENTION) &&
505 ((sshdr.asc == 0x28) ||
506 (sshdr.asc == 0x29)) &&
515 response_len = (unsigned char) inq_result[4] + 5;
516 if (response_len > 255)
517 response_len = first_inquiry_len; /* sanity */
520 * Get any flags for this device.
522 * XXX add a bflags to scsi_device, and replace the
523 * corresponding bit fields in scsi_device, so bflags
524 * need not be passed as an argument.
526 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
529 /* When the first pass succeeds we gain information about
530 * what larger transfer lengths might work. */
532 if (BLIST_INQUIRY_36 & *bflags)
533 next_inquiry_len = 36;
534 else if (BLIST_INQUIRY_58 & *bflags)
535 next_inquiry_len = 58;
536 else if (sdev->inquiry_len)
537 next_inquiry_len = sdev->inquiry_len;
539 next_inquiry_len = response_len;
541 /* If more data is available perform the second pass */
542 if (next_inquiry_len > try_inquiry_len) {
543 try_inquiry_len = next_inquiry_len;
549 } else if (pass == 2) {
550 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
551 "Consider BLIST_INQUIRY_36 for this device\n",
554 /* If this pass failed, the third pass goes back and transfers
555 * the same amount as we successfully got in the first pass. */
556 try_inquiry_len = first_inquiry_len;
561 /* If the last transfer attempt got an error, assume the
562 * peripheral doesn't exist or is dead. */
566 /* Don't report any more data than the device says is valid */
567 sdev->inquiry_len = min(try_inquiry_len, response_len);
570 * XXX Abort if the response length is less than 36? If less than
571 * 32, the lookup of the device flags (above) could be invalid,
572 * and it would be possible to take an incorrect action - we do
573 * not want to hang because of a short INQUIRY. On the flip side,
574 * if the device is spun down or becoming ready (and so it gives a
575 * short INQUIRY), an abort here prevents any further use of the
576 * device, including spin up.
578 * Related to the above issue:
580 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
581 * and if not ready, sent a START_STOP to start (maybe spin up) and
582 * then send the INQUIRY again, since the INQUIRY can change after
583 * a device is initialized.
585 * Ideally, start a device if explicitly asked to do so. This
586 * assumes that a device is spun up on power on, spun down on
587 * request, and then spun up on request.
591 * The scanning code needs to know the scsi_level, even if no
592 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
593 * non-zero LUNs can be scanned.
595 sdev->scsi_level = inq_result[2] & 0x07;
596 if (sdev->scsi_level >= 2 ||
597 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
599 sdev->sdev_target->scsi_level = sdev->scsi_level;
605 * scsi_add_lun - allocate and fully initialze a scsi_device
606 * @sdevscan: holds information to be stored in the new scsi_device
607 * @sdevnew: store the address of the newly allocated scsi_device
608 * @inq_result: holds the result of a previous INQUIRY to the LUN
609 * @bflags: black/white list flag
612 * Allocate and initialize a scsi_device matching sdevscan. Optionally
613 * set fields based on values in *@bflags. If @sdevnew is not
614 * NULL, store the address of the new scsi_device in *@sdevnew (needed
615 * when scanning a particular LUN).
618 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
619 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
621 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
624 * XXX do not save the inquiry, since it can change underneath us,
625 * save just vendor/model/rev.
627 * Rather than save it and have an ioctl that retrieves the saved
628 * value, have an ioctl that executes the same INQUIRY code used
629 * in scsi_probe_lun, let user level programs doing INQUIRY
630 * scanning run at their own risk, or supply a user level program
631 * that can correctly scan.
633 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
634 if (sdev->inquiry == NULL) {
635 return SCSI_SCAN_NO_RESPONSE;
638 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
639 sdev->vendor = (char *) (sdev->inquiry + 8);
640 sdev->model = (char *) (sdev->inquiry + 16);
641 sdev->rev = (char *) (sdev->inquiry + 32);
643 if (*bflags & BLIST_ISROM) {
645 * It would be better to modify sdev->type, and set
646 * sdev->removable, but then the print_inquiry() output
647 * would not show TYPE_ROM; if print_inquiry() is removed
648 * the issue goes away.
650 inq_result[0] = TYPE_ROM;
651 inq_result[1] |= 0x80; /* removable */
652 } else if (*bflags & BLIST_NO_ULD_ATTACH)
653 sdev->no_uld_attach = 1;
655 switch (sdev->type = (inq_result[0] & 0x1f)) {
662 case TYPE_MEDIUM_CHANGER:
673 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
676 print_inquiry(inq_result);
679 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
680 * spec says: The device server is capable of supporting the
681 * specified peripheral device type on this logical unit. However,
682 * the physical device is not currently connected to this logical
685 * The above is vague, as it implies that we could treat 001 and
686 * 011 the same. Stay compatible with previous code, and create a
687 * scsi_device for a PQ of 1
689 * Don't set the device offline here; rather let the upper
690 * level drivers eval the PQ to decide whether they should
691 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
694 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
695 sdev->removable = (0x80 & inq_result[1]) >> 7;
696 sdev->lockable = sdev->removable;
697 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
699 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
700 inq_result[56] & 0x04))
702 if (inq_result[7] & 0x60)
704 if (inq_result[7] & 0x10)
711 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
712 !(*bflags & BLIST_NOTQ))
713 sdev->tagged_supported = 1;
715 * Some devices (Texel CD ROM drives) have handshaking problems
716 * when used with the Seagate controllers. borken is initialized
717 * to 1, and then set it to 0 here.
719 if ((*bflags & BLIST_BORKEN) == 0)
723 * Apparently some really broken devices (contrary to the SCSI
724 * standards) need to be selected without asserting ATN
726 if (*bflags & BLIST_SELECT_NO_ATN)
727 sdev->select_no_atn = 1;
730 * Some devices may not want to have a start command automatically
731 * issued when a device is added.
733 if (*bflags & BLIST_NOSTARTONADD)
734 sdev->no_start_on_add = 1;
736 if (*bflags & BLIST_SINGLELUN)
737 sdev->single_lun = 1;
740 sdev->use_10_for_rw = 1;
742 if (*bflags & BLIST_MS_SKIP_PAGE_08)
743 sdev->skip_ms_page_8 = 1;
745 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
746 sdev->skip_ms_page_3f = 1;
748 if (*bflags & BLIST_USE_10_BYTE_MS)
749 sdev->use_10_for_ms = 1;
751 /* set the device running here so that slave configure
753 scsi_device_set_state(sdev, SDEV_RUNNING);
755 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
756 sdev->use_192_bytes_for_3f = 1;
758 if (*bflags & BLIST_NOT_LOCKABLE)
761 if (*bflags & BLIST_RETRY_HWERROR)
762 sdev->retry_hwerror = 1;
764 transport_configure_device(&sdev->sdev_gendev);
766 if (sdev->host->hostt->slave_configure)
767 sdev->host->hostt->slave_configure(sdev);
770 * Ok, the device is now all set up, we can
771 * register it and tell the rest of the kernel
774 if (scsi_sysfs_add_sdev(sdev) != 0)
775 return SCSI_SCAN_NO_RESPONSE;
777 return SCSI_SCAN_LUN_PRESENT;
780 static inline void scsi_destroy_sdev(struct scsi_device *sdev)
782 if (sdev->host->hostt->slave_destroy)
783 sdev->host->hostt->slave_destroy(sdev);
784 transport_destroy_device(&sdev->sdev_gendev);
785 put_device(&sdev->sdev_gendev);
790 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
791 * @starget: pointer to target device structure
792 * @lun: LUN of target device
793 * @sdevscan: probe the LUN corresponding to this scsi_device
794 * @sdevnew: store the value of any new scsi_device allocated
795 * @bflagsp: store bflags here if not NULL
798 * Call scsi_probe_lun, if a LUN with an attached device is found,
799 * allocate and set it up by calling scsi_add_lun.
802 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
803 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
804 * attached at the LUN
805 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
807 static int scsi_probe_and_add_lun(struct scsi_target *starget,
808 uint lun, int *bflagsp,
809 struct scsi_device **sdevp, int rescan,
812 struct scsi_device *sdev;
813 unsigned char *result;
814 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
815 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
818 * The rescan flag is used as an optimization, the first scan of a
819 * host adapter calls into here with rescan == 0.
821 sdev = scsi_device_lookup_by_target(starget, lun);
823 if (rescan || sdev->sdev_state != SDEV_CREATED) {
824 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
825 "scsi scan: device exists on %s\n",
826 sdev->sdev_gendev.bus_id));
830 scsi_device_put(sdev);
833 *bflagsp = scsi_get_device_flags(sdev,
836 return SCSI_SCAN_LUN_PRESENT;
838 scsi_device_put(sdev);
840 sdev = scsi_alloc_sdev(starget, lun, hostdata);
844 result = kmalloc(result_len, GFP_ATOMIC |
845 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
849 if (scsi_probe_lun(sdev, result, result_len, &bflags))
850 goto out_free_result;
853 * result contains valid SCSI INQUIRY data.
855 if ((result[0] >> 5) == 3) {
857 * For a Peripheral qualifier 3 (011b), the SCSI
858 * spec says: The device server is not capable of
859 * supporting a physical device on this logical
862 * For disks, this implies that there is no
863 * logical disk configured at sdev->lun, but there
864 * is a target id responding.
866 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
867 "scsi scan: peripheral qualifier of 3,"
868 " no device added\n"));
869 res = SCSI_SCAN_TARGET_PRESENT;
870 goto out_free_result;
874 * Non-standard SCSI targets may set the PDT to 0x1f (unknown or
875 * no device type) instead of using the Peripheral Qualifier to
876 * indicate that no LUN is present. For example, USB UFI does this.
878 if (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f) {
879 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
880 "scsi scan: peripheral device type"
881 " of 31, no device added\n"));
882 res = SCSI_SCAN_TARGET_PRESENT;
883 goto out_free_result;
886 res = scsi_add_lun(sdev, result, &bflags);
887 if (res == SCSI_SCAN_LUN_PRESENT) {
888 if (bflags & BLIST_KEY) {
890 scsi_unlock_floptical(sdev, result);
899 if (res == SCSI_SCAN_LUN_PRESENT) {
901 if (scsi_device_get(sdev) == 0) {
904 __scsi_remove_device(sdev);
905 res = SCSI_SCAN_NO_RESPONSE;
909 scsi_destroy_sdev(sdev);
915 * scsi_sequential_lun_scan - sequentially scan a SCSI target
916 * @starget: pointer to target structure to scan
917 * @bflags: black/white list flag for LUN 0
918 * @lun0_res: result of scanning LUN 0
921 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
922 * scanned) to some maximum lun until a LUN is found with no device
923 * attached. Use the bflags to figure out any oddities.
925 * Modifies sdevscan->lun.
927 static void scsi_sequential_lun_scan(struct scsi_target *starget,
928 int bflags, int lun0_res, int scsi_level,
931 unsigned int sparse_lun, lun, max_dev_lun;
932 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
934 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
935 "%s\n", starget->dev.bus_id));
937 max_dev_lun = min(max_scsi_luns, shost->max_lun);
939 * If this device is known to support sparse multiple units,
940 * override the other settings, and scan all of them. Normally,
941 * SCSI-3 devices should be scanned via the REPORT LUNS.
943 if (bflags & BLIST_SPARSELUN) {
944 max_dev_lun = shost->max_lun;
950 * If not sparse lun and no device attached at LUN 0 do not scan
953 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
957 * If less than SCSI_1_CSS, and no special lun scaning, stop
958 * scanning; this matches 2.4 behaviour, but could just be a bug
959 * (to continue scanning a SCSI_1_CSS device).
961 * This test is broken. We might not have any device on lun0 for
962 * a sparselun device, and if that's the case then how would we
963 * know the real scsi_level, eh? It might make sense to just not
964 * scan any SCSI_1 device for non-0 luns, but that check would best
965 * go into scsi_alloc_sdev() and just have it return null when asked
966 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
968 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
969 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
974 * If this device is known to support multiple units, override
975 * the other settings, and scan all of them.
977 if (bflags & BLIST_FORCELUN)
978 max_dev_lun = shost->max_lun;
980 * REGAL CDC-4X: avoid hang after LUN 4
982 if (bflags & BLIST_MAX5LUN)
983 max_dev_lun = min(5U, max_dev_lun);
985 * Do not scan SCSI-2 or lower device past LUN 7, unless
988 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
989 max_dev_lun = min(8U, max_dev_lun);
992 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
993 * until we reach the max, or no LUN is found and we are not
996 for (lun = 1; lun < max_dev_lun; ++lun)
997 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
998 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1004 * scsilun_to_int: convert a scsi_lun to an int
1005 * @scsilun: struct scsi_lun to be converted.
1008 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1009 * integer, and return the result. The caller must check for
1010 * truncation before using this function.
1013 * The struct scsi_lun is assumed to be four levels, with each level
1014 * effectively containing a SCSI byte-ordered (big endian) short; the
1015 * addressing bits of each level are ignored (the highest two bits).
1016 * For a description of the LUN format, post SCSI-3 see the SCSI
1017 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1019 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1020 * the integer: 0x0b030a04
1022 static int scsilun_to_int(struct scsi_lun *scsilun)
1028 for (i = 0; i < sizeof(lun); i += 2)
1029 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1030 scsilun->scsi_lun[i + 1]) << (i * 8));
1035 * int_to_scsilun: reverts an int into a scsi_lun
1036 * @int: integer to be reverted
1037 * @scsilun: struct scsi_lun to be set.
1040 * Reverts the functionality of the scsilun_to_int, which packed
1041 * an 8-byte lun value into an int. This routine unpacks the int
1042 * back into the lun value.
1043 * Note: the scsilun_to_int() routine does not truly handle all
1044 * 8bytes of the lun value. This functions restores only as much
1045 * as was set by the routine.
1048 * Given an integer : 0x0b030a04, this function returns a
1049 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1052 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1056 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1058 for (i = 0; i < sizeof(lun); i += 2) {
1059 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1060 scsilun->scsi_lun[i+1] = lun & 0xFF;
1064 EXPORT_SYMBOL(int_to_scsilun);
1067 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1068 * @sdevscan: scan the host, channel, and id of this scsi_device
1071 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
1072 * command, and scan the resulting list of LUNs by calling
1073 * scsi_probe_and_add_lun.
1075 * Modifies sdevscan->lun.
1078 * 0: scan completed (or no memory, so further scanning is futile)
1079 * 1: no report lun scan, or not configured
1081 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1085 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1086 unsigned int length;
1088 unsigned int num_luns;
1089 unsigned int retries;
1091 struct scsi_lun *lunp, *lun_data;
1093 struct scsi_sense_hdr sshdr;
1094 struct scsi_device *sdev;
1095 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1099 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1100 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1101 * support more than 8 LUNs.
1103 if ((bflags & BLIST_NOREPORTLUN) ||
1104 starget->scsi_level < SCSI_2 ||
1105 (starget->scsi_level < SCSI_3 &&
1106 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) )
1108 if (bflags & BLIST_NOLUN)
1111 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1112 sdev = scsi_alloc_sdev(starget, 0, NULL);
1115 if (scsi_device_get(sdev))
1119 sprintf(devname, "host %d channel %d id %d",
1120 shost->host_no, sdev->channel, sdev->id);
1123 * Allocate enough to hold the header (the same size as one scsi_lun)
1124 * plus the max number of luns we are requesting.
1126 * Reallocating and trying again (with the exact amount we need)
1127 * would be nice, but then we need to somehow limit the size
1128 * allocated based on the available memory and the limits of
1129 * kmalloc - we don't want a kmalloc() failure of a huge value to
1130 * prevent us from finding any LUNs on this target.
1132 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1133 lun_data = kmalloc(length, GFP_ATOMIC |
1134 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1136 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1140 scsi_cmd[0] = REPORT_LUNS;
1143 * bytes 1 - 5: reserved, set to zero.
1145 memset(&scsi_cmd[1], 0, 5);
1148 * bytes 6 - 9: length of the command.
1150 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1151 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1152 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1153 scsi_cmd[9] = (unsigned char) length & 0xff;
1155 scsi_cmd[10] = 0; /* reserved */
1156 scsi_cmd[11] = 0; /* control */
1159 * We can get a UNIT ATTENTION, for example a power on/reset, so
1160 * retry a few times (like sd.c does for TEST UNIT READY).
1161 * Experience shows some combinations of adapter/devices get at
1162 * least two power on/resets.
1164 * Illegal requests (for devices that do not support REPORT LUNS)
1165 * should come through as a check condition, and will not generate
1168 for (retries = 0; retries < 3; retries++) {
1169 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1170 " REPORT LUNS to %s (try %d)\n", devname,
1173 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1174 lun_data, length, &sshdr,
1175 SCSI_TIMEOUT + 4 * HZ, 3);
1177 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1178 " %s (try %d) result 0x%x\n", result
1179 ? "failed" : "successful", retries, result));
1182 else if (scsi_sense_valid(&sshdr)) {
1183 if (sshdr.sense_key != UNIT_ATTENTION)
1190 * The device probably does not support a REPORT LUN command
1197 * Get the length from the first four bytes of lun_data.
1199 data = (u8 *) lun_data->scsi_lun;
1200 length = ((data[0] << 24) | (data[1] << 16) |
1201 (data[2] << 8) | (data[3] << 0));
1203 num_luns = (length / sizeof(struct scsi_lun));
1204 if (num_luns > max_scsi_report_luns) {
1205 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1206 " of %d luns reported, try increasing"
1207 " max_scsi_report_luns.\n", devname,
1208 max_scsi_report_luns, num_luns);
1209 num_luns = max_scsi_report_luns;
1212 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1213 "scsi scan: REPORT LUN scan\n"));
1216 * Scan the luns in lun_data. The entry at offset 0 is really
1217 * the header, so start at 1 and go up to and including num_luns.
1219 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1220 lun = scsilun_to_int(lunp);
1223 * Check if the unused part of lunp is non-zero, and so
1224 * does not fit in lun.
1226 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1230 * Output an error displaying the LUN in byte order,
1231 * this differs from what linux would print for the
1232 * integer LUN value.
1234 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1235 data = (char *)lunp->scsi_lun;
1236 for (i = 0; i < sizeof(struct scsi_lun); i++)
1237 printk("%02x", data[i]);
1238 printk(" has a LUN larger than currently supported.\n");
1239 } else if (lun > sdev->host->max_lun) {
1240 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1241 " than allowed by the host adapter\n",
1246 res = scsi_probe_and_add_lun(starget,
1247 lun, NULL, NULL, rescan, NULL);
1248 if (res == SCSI_SCAN_NO_RESPONSE) {
1250 * Got some results, but now none, abort.
1252 sdev_printk(KERN_ERR, sdev,
1253 "Unexpected response"
1254 " from lun %d while scanning, scan"
1264 scsi_device_put(sdev);
1265 if (sdev->sdev_state == SDEV_CREATED)
1267 * the sdev we used didn't appear in the report luns scan
1269 scsi_destroy_sdev(sdev);
1273 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1274 uint id, uint lun, void *hostdata)
1276 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1277 struct device *parent = &shost->shost_gendev;
1278 struct scsi_target *starget;
1280 starget = scsi_alloc_target(parent, channel, id);
1282 return ERR_PTR(-ENOMEM);
1284 get_device(&starget->dev);
1285 mutex_lock(&shost->scan_mutex);
1286 if (scsi_host_scan_allowed(shost))
1287 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1288 mutex_unlock(&shost->scan_mutex);
1289 scsi_target_reap(starget);
1290 put_device(&starget->dev);
1294 EXPORT_SYMBOL(__scsi_add_device);
1296 int scsi_add_device(struct Scsi_Host *host, uint channel,
1297 uint target, uint lun)
1299 struct scsi_device *sdev =
1300 __scsi_add_device(host, channel, target, lun, NULL);
1302 return PTR_ERR(sdev);
1304 scsi_device_put(sdev);
1307 EXPORT_SYMBOL(scsi_add_device);
1309 void scsi_rescan_device(struct device *dev)
1311 struct scsi_driver *drv;
1316 drv = to_scsi_driver(dev->driver);
1317 if (try_module_get(drv->owner)) {
1320 module_put(drv->owner);
1323 EXPORT_SYMBOL(scsi_rescan_device);
1325 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1326 unsigned int id, unsigned int lun, int rescan)
1328 struct Scsi_Host *shost = dev_to_shost(parent);
1331 struct scsi_target *starget;
1333 if (shost->this_id == id)
1335 * Don't scan the host adapter
1339 starget = scsi_alloc_target(parent, channel, id);
1343 get_device(&starget->dev);
1344 if (lun != SCAN_WILD_CARD) {
1346 * Scan for a specific host/chan/id/lun.
1348 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1353 * Scan LUN 0, if there is some response, scan further. Ideally, we
1354 * would not configure LUN 0 until all LUNs are scanned.
1356 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1357 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1358 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1360 * The REPORT LUN did not scan the target,
1361 * do a sequential scan.
1363 scsi_sequential_lun_scan(starget, bflags,
1364 res, starget->scsi_level, rescan);
1368 /* now determine if the target has any children at all
1369 * and if not, nuke it */
1370 scsi_target_reap(starget);
1372 put_device(&starget->dev);
1376 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1378 * @parent: host to scan
1379 * @channel: channel to scan
1380 * @id: target id to scan
1381 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1382 * @rescan: passed to LUN scanning routines
1385 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1386 * and possibly all LUNs on the target id.
1388 * First try a REPORT LUN scan, if that does not scan the target, do a
1389 * sequential scan of LUNs on the target id.
1391 void scsi_scan_target(struct device *parent, unsigned int channel,
1392 unsigned int id, unsigned int lun, int rescan)
1394 struct Scsi_Host *shost = dev_to_shost(parent);
1396 mutex_lock(&shost->scan_mutex);
1397 if (scsi_host_scan_allowed(shost))
1398 __scsi_scan_target(parent, channel, id, lun, rescan);
1399 mutex_unlock(&shost->scan_mutex);
1401 EXPORT_SYMBOL(scsi_scan_target);
1403 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1404 unsigned int id, unsigned int lun, int rescan)
1408 if (id == SCAN_WILD_CARD)
1409 for (id = 0; id < shost->max_id; ++id) {
1411 * XXX adapter drivers when possible (FCP, iSCSI)
1412 * could modify max_id to match the current max,
1413 * not the absolute max.
1415 * XXX add a shost id iterator, so for example,
1416 * the FC ID can be the same as a target id
1417 * without a huge overhead of sparse id's.
1419 if (shost->reverse_ordering)
1421 * Scan from high to low id.
1423 order_id = shost->max_id - id - 1;
1426 __scsi_scan_target(&shost->shost_gendev, channel,
1427 order_id, lun, rescan);
1430 __scsi_scan_target(&shost->shost_gendev, channel,
1434 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1435 unsigned int id, unsigned int lun, int rescan)
1437 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1439 __FUNCTION__, channel, id, lun));
1441 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1442 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1443 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1446 mutex_lock(&shost->scan_mutex);
1447 if (scsi_host_scan_allowed(shost)) {
1448 if (channel == SCAN_WILD_CARD)
1449 for (channel = 0; channel <= shost->max_channel;
1451 scsi_scan_channel(shost, channel, id, lun,
1454 scsi_scan_channel(shost, channel, id, lun, rescan);
1456 mutex_unlock(&shost->scan_mutex);
1462 * scsi_scan_host - scan the given adapter
1463 * @shost: adapter to scan
1465 void scsi_scan_host(struct Scsi_Host *shost)
1467 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1470 EXPORT_SYMBOL(scsi_scan_host);
1472 void scsi_forget_host(struct Scsi_Host *shost)
1474 struct scsi_device *sdev;
1475 unsigned long flags;
1478 spin_lock_irqsave(shost->host_lock, flags);
1479 list_for_each_entry(sdev, &shost->__devices, siblings) {
1480 if (sdev->sdev_state == SDEV_DEL)
1482 spin_unlock_irqrestore(shost->host_lock, flags);
1483 __scsi_remove_device(sdev);
1486 spin_unlock_irqrestore(shost->host_lock, flags);
1490 * Function: scsi_get_host_dev()
1492 * Purpose: Create a scsi_device that points to the host adapter itself.
1494 * Arguments: SHpnt - Host that needs a scsi_device
1496 * Lock status: None assumed.
1498 * Returns: The scsi_device or NULL
1501 * Attach a single scsi_device to the Scsi_Host - this should
1502 * be made to look like a "pseudo-device" that points to the
1505 * Note - this device is not accessible from any high-level
1506 * drivers (including generics), which is probably not
1507 * optimal. We can add hooks later to attach
1509 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1511 struct scsi_device *sdev = NULL;
1512 struct scsi_target *starget;
1514 mutex_lock(&shost->scan_mutex);
1515 if (!scsi_host_scan_allowed(shost))
1517 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1521 sdev = scsi_alloc_sdev(starget, 0, NULL);
1523 sdev->sdev_gendev.parent = get_device(&starget->dev);
1526 put_device(&starget->dev);
1528 mutex_unlock(&shost->scan_mutex);
1531 EXPORT_SYMBOL(scsi_get_host_dev);
1534 * Function: scsi_free_host_dev()
1536 * Purpose: Free a scsi_device that points to the host adapter itself.
1538 * Arguments: SHpnt - Host that needs a scsi_device
1540 * Lock status: None assumed.
1546 void scsi_free_host_dev(struct scsi_device *sdev)
1548 BUG_ON(sdev->id != sdev->host->this_id);
1550 scsi_destroy_sdev(sdev);
1552 EXPORT_SYMBOL(scsi_free_host_dev);