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/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/init.h>
31 #include <linux/blkdev.h>
32 #include <asm/semaphore.h>
34 #include <scsi/scsi.h>
35 #include <scsi/scsi_cmnd.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_transport.h>
41 #include <scsi/scsi_eh.h>
43 #include "scsi_priv.h"
44 #include "scsi_logging.h"
46 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
47 " SCSI scanning, some SCSI devices might not be configured\n"
52 #define SCSI_TIMEOUT (2*HZ)
55 * Prefix values for the SCSI id's (stored in driverfs name field)
57 #define SCSI_UID_SER_NUM 'S'
58 #define SCSI_UID_UNKNOWN 'Z'
61 * Return values of some of the scanning functions.
63 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
64 * includes allocation or general failures preventing IO from being sent.
66 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
69 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
72 #define SCSI_SCAN_NO_RESPONSE 0
73 #define SCSI_SCAN_TARGET_PRESENT 1
74 #define SCSI_SCAN_LUN_PRESENT 2
76 static const char *scsi_null_device_strs = "nullnullnullnull";
78 #define MAX_SCSI_LUNS 512
80 #ifdef CONFIG_SCSI_MULTI_LUN
81 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
83 static unsigned int max_scsi_luns = 1;
86 module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR);
87 MODULE_PARM_DESC(max_luns,
88 "last scsi LUN (should be between 1 and 2^32-1)");
91 * max_scsi_report_luns: the maximum number of LUNS that will be
92 * returned from the REPORT LUNS command. 8 times this value must
93 * be allocated. In theory this could be up to an 8 byte value, but
94 * in practice, the maximum number of LUNs suppored by any device
97 static unsigned int max_scsi_report_luns = 511;
99 module_param_named(max_report_luns, max_scsi_report_luns, int, S_IRUGO|S_IWUSR);
100 MODULE_PARM_DESC(max_report_luns,
101 "REPORT LUNS maximum number of LUNS received (should be"
102 " between 1 and 16384)");
104 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
106 module_param_named(inq_timeout, scsi_inq_timeout, int, S_IRUGO|S_IWUSR);
107 MODULE_PARM_DESC(inq_timeout,
108 "Timeout (in seconds) waiting for devices to answer INQUIRY."
109 " Default is 5. Some non-compliant devices need more.");
112 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
113 * @sdev: scsi device to send command to
114 * @result: area to store the result of the MODE SENSE
117 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
118 * Called for BLIST_KEY devices.
120 static void scsi_unlock_floptical(struct scsi_device *sdev,
121 unsigned char *result)
123 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
125 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
126 scsi_cmd[0] = MODE_SENSE;
130 scsi_cmd[4] = 0x2a; /* size */
132 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
137 * scsi_alloc_sdev - allocate and setup a scsi_Device
140 * Allocate, initialize for io, and return a pointer to a scsi_Device.
141 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
142 * adds scsi_Device to the appropriate list.
145 * scsi_Device pointer, or NULL on failure.
147 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
148 unsigned int lun, void *hostdata)
150 struct scsi_device *sdev;
151 int display_failure_msg = 1, ret;
152 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
154 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
159 sdev->vendor = scsi_null_device_strs;
160 sdev->model = scsi_null_device_strs;
161 sdev->rev = scsi_null_device_strs;
163 sdev->id = starget->id;
165 sdev->channel = starget->channel;
166 sdev->sdev_state = SDEV_CREATED;
167 INIT_LIST_HEAD(&sdev->siblings);
168 INIT_LIST_HEAD(&sdev->same_target_siblings);
169 INIT_LIST_HEAD(&sdev->cmd_list);
170 INIT_LIST_HEAD(&sdev->starved_entry);
171 spin_lock_init(&sdev->list_lock);
173 sdev->sdev_gendev.parent = get_device(&starget->dev);
174 sdev->sdev_target = starget;
176 /* usually NULL and set by ->slave_alloc instead */
177 sdev->hostdata = hostdata;
179 /* if the device needs this changing, it may do so in the
180 * slave_configure function */
181 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
184 * Some low level driver could use device->type
189 * Assume that the device will have handshaking problems,
190 * and then fix this field later if it turns out it
195 sdev->request_queue = scsi_alloc_queue(sdev);
196 if (!sdev->request_queue) {
197 /* release fn is set up in scsi_sysfs_device_initialise, so
198 * have to free and put manually here */
199 put_device(&starget->dev);
204 sdev->request_queue->queuedata = sdev;
205 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
207 scsi_sysfs_device_initialize(sdev);
209 if (shost->hostt->slave_alloc) {
210 ret = shost->hostt->slave_alloc(sdev);
213 * if LLDD reports slave not present, don't clutter
214 * console with alloc failure messages
217 display_failure_msg = 0;
218 goto out_device_destroy;
225 transport_destroy_device(&sdev->sdev_gendev);
226 put_device(&sdev->sdev_gendev);
228 if (display_failure_msg)
229 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
233 static void scsi_target_dev_release(struct device *dev)
235 struct device *parent = dev->parent;
236 struct scsi_target *starget = to_scsi_target(dev);
242 int scsi_is_target_device(const struct device *dev)
244 return dev->release == scsi_target_dev_release;
246 EXPORT_SYMBOL(scsi_is_target_device);
248 static struct scsi_target *__scsi_find_target(struct device *parent,
249 int channel, uint id)
251 struct scsi_target *starget, *found_starget = NULL;
252 struct Scsi_Host *shost = dev_to_shost(parent);
254 * Search for an existing target for this sdev.
256 list_for_each_entry(starget, &shost->__targets, siblings) {
257 if (starget->id == id &&
258 starget->channel == channel) {
259 found_starget = starget;
264 get_device(&found_starget->dev);
266 return found_starget;
269 static struct scsi_target *scsi_alloc_target(struct device *parent,
270 int channel, uint id)
272 struct Scsi_Host *shost = dev_to_shost(parent);
273 struct device *dev = NULL;
275 const int size = sizeof(struct scsi_target)
276 + shost->transportt->target_size;
277 struct scsi_target *starget;
278 struct scsi_target *found_target;
281 starget = kzalloc(size, GFP_KERNEL);
283 printk(KERN_ERR "%s: allocation failure\n", __FUNCTION__);
287 device_initialize(dev);
288 starget->reap_ref = 1;
289 dev->parent = get_device(parent);
290 dev->release = scsi_target_dev_release;
291 sprintf(dev->bus_id, "target%d:%d:%d",
292 shost->host_no, channel, id);
294 starget->channel = channel;
295 INIT_LIST_HEAD(&starget->siblings);
296 INIT_LIST_HEAD(&starget->devices);
297 starget->state = STARGET_RUNNING;
299 spin_lock_irqsave(shost->host_lock, flags);
301 found_target = __scsi_find_target(parent, channel, id);
305 list_add_tail(&starget->siblings, &shost->__targets);
306 spin_unlock_irqrestore(shost->host_lock, flags);
307 /* allocate and add */
308 transport_setup_device(dev);
309 error = device_add(dev);
311 dev_err(dev, "target device_add failed, error %d\n", error);
312 spin_lock_irqsave(shost->host_lock, flags);
313 list_del_init(&starget->siblings);
314 spin_unlock_irqrestore(shost->host_lock, flags);
315 transport_destroy_device(dev);
320 transport_add_device(dev);
321 if (shost->hostt->target_alloc) {
322 error = shost->hostt->target_alloc(starget);
325 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
326 /* don't want scsi_target_reap to do the final
327 * put because it will be under the host lock */
329 scsi_target_reap(starget);
338 found_target->reap_ref++;
339 spin_unlock_irqrestore(shost->host_lock, flags);
341 if (found_target->state != STARGET_DEL) {
345 /* Unfortunately, we found a dying target; need to
346 * wait until it's dead before we can get a new one */
347 put_device(&found_target->dev);
348 flush_scheduled_work();
352 static void scsi_target_reap_usercontext(void *data)
354 struct scsi_target *starget = data;
355 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
358 transport_remove_device(&starget->dev);
359 device_del(&starget->dev);
360 transport_destroy_device(&starget->dev);
361 spin_lock_irqsave(shost->host_lock, flags);
362 if (shost->hostt->target_destroy)
363 shost->hostt->target_destroy(starget);
364 list_del_init(&starget->siblings);
365 spin_unlock_irqrestore(shost->host_lock, flags);
366 put_device(&starget->dev);
370 * scsi_target_reap - check to see if target is in use and destroy if not
372 * @starget: target to be checked
374 * This is used after removing a LUN or doing a last put of the target
375 * it checks atomically that nothing is using the target and removes
378 void scsi_target_reap(struct scsi_target *starget)
380 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
383 spin_lock_irqsave(shost->host_lock, flags);
385 if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
386 BUG_ON(starget->state == STARGET_DEL);
387 starget->state = STARGET_DEL;
388 spin_unlock_irqrestore(shost->host_lock, flags);
389 execute_in_process_context(scsi_target_reap_usercontext,
390 starget, &starget->ew);
394 spin_unlock_irqrestore(shost->host_lock, flags);
400 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
401 * @sdev: scsi_device to probe
402 * @inq_result: area to store the INQUIRY result
403 * @result_len: len of inq_result
404 * @bflags: store any bflags found here
407 * Probe the lun associated with @req using a standard SCSI INQUIRY;
409 * If the INQUIRY is successful, zero is returned and the
410 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
411 * are copied to the scsi_device any flags value is stored in *@bflags.
413 static int scsi_probe_lun(struct scsi_device *sdev, char *inq_result,
414 int result_len, int *bflags)
416 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
417 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
418 int response_len = 0;
419 int pass, count, result;
420 struct scsi_sense_hdr sshdr;
424 /* Perform up to 3 passes. The first pass uses a conservative
425 * transfer length of 36 unless sdev->inquiry_len specifies a
426 * different value. */
427 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
428 try_inquiry_len = first_inquiry_len;
432 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
433 "scsi scan: INQUIRY pass %d length %d\n",
434 pass, try_inquiry_len));
436 /* Each pass gets up to three chances to ignore Unit Attention */
437 for (count = 0; count < 3; ++count) {
438 memset(scsi_cmd, 0, 6);
439 scsi_cmd[0] = INQUIRY;
440 scsi_cmd[4] = (unsigned char) try_inquiry_len;
442 memset(inq_result, 0, try_inquiry_len);
444 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
445 inq_result, try_inquiry_len, &sshdr,
446 HZ / 2 + HZ * scsi_inq_timeout, 3);
448 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
450 result ? "failed" : "successful", result));
454 * not-ready to ready transition [asc/ascq=0x28/0x0]
455 * or power-on, reset [asc/ascq=0x29/0x0], continue.
456 * INQUIRY should not yield UNIT_ATTENTION
457 * but many buggy devices do so anyway.
459 if ((driver_byte(result) & DRIVER_SENSE) &&
460 scsi_sense_valid(&sshdr)) {
461 if ((sshdr.sense_key == UNIT_ATTENTION) &&
462 ((sshdr.asc == 0x28) ||
463 (sshdr.asc == 0x29)) &&
472 response_len = (unsigned char) inq_result[4] + 5;
473 if (response_len > 255)
474 response_len = first_inquiry_len; /* sanity */
477 * Get any flags for this device.
479 * XXX add a bflags to scsi_device, and replace the
480 * corresponding bit fields in scsi_device, so bflags
481 * need not be passed as an argument.
483 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
486 /* When the first pass succeeds we gain information about
487 * what larger transfer lengths might work. */
489 if (BLIST_INQUIRY_36 & *bflags)
490 next_inquiry_len = 36;
491 else if (BLIST_INQUIRY_58 & *bflags)
492 next_inquiry_len = 58;
493 else if (sdev->inquiry_len)
494 next_inquiry_len = sdev->inquiry_len;
496 next_inquiry_len = response_len;
498 /* If more data is available perform the second pass */
499 if (next_inquiry_len > try_inquiry_len) {
500 try_inquiry_len = next_inquiry_len;
506 } else if (pass == 2) {
507 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
508 "Consider BLIST_INQUIRY_36 for this device\n",
511 /* If this pass failed, the third pass goes back and transfers
512 * the same amount as we successfully got in the first pass. */
513 try_inquiry_len = first_inquiry_len;
518 /* If the last transfer attempt got an error, assume the
519 * peripheral doesn't exist or is dead. */
523 /* Don't report any more data than the device says is valid */
524 sdev->inquiry_len = min(try_inquiry_len, response_len);
527 * XXX Abort if the response length is less than 36? If less than
528 * 32, the lookup of the device flags (above) could be invalid,
529 * and it would be possible to take an incorrect action - we do
530 * not want to hang because of a short INQUIRY. On the flip side,
531 * if the device is spun down or becoming ready (and so it gives a
532 * short INQUIRY), an abort here prevents any further use of the
533 * device, including spin up.
535 * Related to the above issue:
537 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
538 * and if not ready, sent a START_STOP to start (maybe spin up) and
539 * then send the INQUIRY again, since the INQUIRY can change after
540 * a device is initialized.
542 * Ideally, start a device if explicitly asked to do so. This
543 * assumes that a device is spun up on power on, spun down on
544 * request, and then spun up on request.
548 * The scanning code needs to know the scsi_level, even if no
549 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
550 * non-zero LUNs can be scanned.
552 sdev->scsi_level = inq_result[2] & 0x07;
553 if (sdev->scsi_level >= 2 ||
554 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
556 sdev->sdev_target->scsi_level = sdev->scsi_level;
562 * scsi_add_lun - allocate and fully initialze a scsi_device
563 * @sdevscan: holds information to be stored in the new scsi_device
564 * @sdevnew: store the address of the newly allocated scsi_device
565 * @inq_result: holds the result of a previous INQUIRY to the LUN
566 * @bflags: black/white list flag
569 * Allocate and initialize a scsi_device matching sdevscan. Optionally
570 * set fields based on values in *@bflags. If @sdevnew is not
571 * NULL, store the address of the new scsi_device in *@sdevnew (needed
572 * when scanning a particular LUN).
575 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
576 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
578 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
581 * XXX do not save the inquiry, since it can change underneath us,
582 * save just vendor/model/rev.
584 * Rather than save it and have an ioctl that retrieves the saved
585 * value, have an ioctl that executes the same INQUIRY code used
586 * in scsi_probe_lun, let user level programs doing INQUIRY
587 * scanning run at their own risk, or supply a user level program
588 * that can correctly scan.
590 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
591 if (sdev->inquiry == NULL) {
592 return SCSI_SCAN_NO_RESPONSE;
595 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
596 sdev->vendor = (char *) (sdev->inquiry + 8);
597 sdev->model = (char *) (sdev->inquiry + 16);
598 sdev->rev = (char *) (sdev->inquiry + 32);
600 if (*bflags & BLIST_ISROM) {
602 * It would be better to modify sdev->type, and set
603 * sdev->removable; this can now be done since
604 * print_inquiry has gone away.
606 inq_result[0] = TYPE_ROM;
607 inq_result[1] |= 0x80; /* removable */
608 } else if (*bflags & BLIST_NO_ULD_ATTACH)
609 sdev->no_uld_attach = 1;
611 switch (sdev->type = (inq_result[0] & 0x1f)) {
618 case TYPE_MEDIUM_CHANGER:
630 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
634 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
635 * spec says: The device server is capable of supporting the
636 * specified peripheral device type on this logical unit. However,
637 * the physical device is not currently connected to this logical
640 * The above is vague, as it implies that we could treat 001 and
641 * 011 the same. Stay compatible with previous code, and create a
642 * scsi_device for a PQ of 1
644 * Don't set the device offline here; rather let the upper
645 * level drivers eval the PQ to decide whether they should
646 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
649 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
650 sdev->removable = (0x80 & inq_result[1]) >> 7;
651 sdev->lockable = sdev->removable;
652 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
654 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
655 inq_result[56] & 0x04))
657 if (inq_result[7] & 0x60)
659 if (inq_result[7] & 0x10)
662 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
663 "ANSI: %d%s\n", scsi_device_type(sdev->type),
664 sdev->vendor, sdev->model, sdev->rev,
665 sdev->inq_periph_qual, inq_result[2] & 0x07,
666 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
672 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
673 !(*bflags & BLIST_NOTQ))
674 sdev->tagged_supported = 1;
676 * Some devices (Texel CD ROM drives) have handshaking problems
677 * when used with the Seagate controllers. borken is initialized
678 * to 1, and then set it to 0 here.
680 if ((*bflags & BLIST_BORKEN) == 0)
684 * Apparently some really broken devices (contrary to the SCSI
685 * standards) need to be selected without asserting ATN
687 if (*bflags & BLIST_SELECT_NO_ATN)
688 sdev->select_no_atn = 1;
691 * Maximum 512 sector transfer length
692 * broken RA4x00 Compaq Disk Array
694 if (*bflags & BLIST_MAX_512)
695 blk_queue_max_sectors(sdev->request_queue, 512);
698 * Some devices may not want to have a start command automatically
699 * issued when a device is added.
701 if (*bflags & BLIST_NOSTARTONADD)
702 sdev->no_start_on_add = 1;
704 if (*bflags & BLIST_SINGLELUN)
705 sdev->single_lun = 1;
708 sdev->use_10_for_rw = 1;
710 if (*bflags & BLIST_MS_SKIP_PAGE_08)
711 sdev->skip_ms_page_8 = 1;
713 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
714 sdev->skip_ms_page_3f = 1;
716 if (*bflags & BLIST_USE_10_BYTE_MS)
717 sdev->use_10_for_ms = 1;
719 /* set the device running here so that slave configure
721 scsi_device_set_state(sdev, SDEV_RUNNING);
723 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
724 sdev->use_192_bytes_for_3f = 1;
726 if (*bflags & BLIST_NOT_LOCKABLE)
729 if (*bflags & BLIST_RETRY_HWERROR)
730 sdev->retry_hwerror = 1;
732 transport_configure_device(&sdev->sdev_gendev);
734 if (sdev->host->hostt->slave_configure) {
735 int ret = sdev->host->hostt->slave_configure(sdev);
738 * if LLDD reports slave not present, don't clutter
739 * console with alloc failure messages
742 sdev_printk(KERN_ERR, sdev,
743 "failed to configure device\n");
745 return SCSI_SCAN_NO_RESPONSE;
750 * Ok, the device is now all set up, we can
751 * register it and tell the rest of the kernel
754 if (scsi_sysfs_add_sdev(sdev) != 0)
755 return SCSI_SCAN_NO_RESPONSE;
757 return SCSI_SCAN_LUN_PRESENT;
760 static inline void scsi_destroy_sdev(struct scsi_device *sdev)
762 scsi_device_set_state(sdev, SDEV_DEL);
763 if (sdev->host->hostt->slave_destroy)
764 sdev->host->hostt->slave_destroy(sdev);
765 transport_destroy_device(&sdev->sdev_gendev);
766 put_device(&sdev->sdev_gendev);
769 #ifdef CONFIG_SCSI_LOGGING
771 * scsi_inq_str - print INQUIRY data from min to max index,
772 * strip trailing whitespace
773 * @buf: Output buffer with at least end-first+1 bytes of space
774 * @inq: Inquiry buffer (input)
775 * @first: Offset of string into inq
776 * @end: Index after last character in inq
778 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
779 unsigned first, unsigned end)
781 unsigned term = 0, idx;
783 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
784 if (inq[idx+first] > ' ') {
785 buf[idx] = inq[idx+first];
797 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
798 * @starget: pointer to target device structure
799 * @lun: LUN of target device
800 * @sdevscan: probe the LUN corresponding to this scsi_device
801 * @sdevnew: store the value of any new scsi_device allocated
802 * @bflagsp: store bflags here if not NULL
805 * Call scsi_probe_lun, if a LUN with an attached device is found,
806 * allocate and set it up by calling scsi_add_lun.
809 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
810 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
811 * attached at the LUN
812 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
814 static int scsi_probe_and_add_lun(struct scsi_target *starget,
815 uint lun, int *bflagsp,
816 struct scsi_device **sdevp, int rescan,
819 struct scsi_device *sdev;
820 unsigned char *result;
821 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
822 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
825 * The rescan flag is used as an optimization, the first scan of a
826 * host adapter calls into here with rescan == 0.
828 sdev = scsi_device_lookup_by_target(starget, lun);
830 if (rescan || sdev->sdev_state != SDEV_CREATED) {
831 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
832 "scsi scan: device exists on %s\n",
833 sdev->sdev_gendev.bus_id));
837 scsi_device_put(sdev);
840 *bflagsp = scsi_get_device_flags(sdev,
843 return SCSI_SCAN_LUN_PRESENT;
845 scsi_device_put(sdev);
847 sdev = scsi_alloc_sdev(starget, lun, hostdata);
851 result = kmalloc(result_len, GFP_ATOMIC |
852 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
856 if (scsi_probe_lun(sdev, result, result_len, &bflags))
857 goto out_free_result;
862 * result contains valid SCSI INQUIRY data.
864 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
866 * For a Peripheral qualifier 3 (011b), the SCSI
867 * spec says: The device server is not capable of
868 * supporting a physical device on this logical
871 * For disks, this implies that there is no
872 * logical disk configured at sdev->lun, but there
873 * is a target id responding.
875 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
876 " peripheral qualifier of 3, device not"
879 SCSI_LOG_SCAN_BUS(1, {
880 unsigned char vend[9];
881 unsigned char mod[17];
883 sdev_printk(KERN_INFO, sdev,
884 "scsi scan: consider passing scsi_mod."
885 "dev_flags=%s:%s:0x240 or 0x800240\n",
886 scsi_inq_str(vend, result, 8, 16),
887 scsi_inq_str(mod, result, 16, 32));
891 res = SCSI_SCAN_TARGET_PRESENT;
892 goto out_free_result;
896 * Some targets may set slight variations of PQ and PDT to signal
897 * that no LUN is present, so don't add sdev in these cases.
898 * Two specific examples are:
899 * 1) NetApp targets: return PQ=1, PDT=0x1f
900 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
901 * in the UFI 1.0 spec (we cannot rely on reserved bits).
904 * 1) SCSI SPC-3, pp. 145-146
905 * PQ=1: "A peripheral device having the specified peripheral
906 * device type is not connected to this logical unit. However, the
907 * device server is capable of supporting the specified peripheral
908 * device type on this logical unit."
909 * PDT=0x1f: "Unknown or no device type"
910 * 2) USB UFI 1.0, p. 20
911 * PDT=00h Direct-access device (floppy)
912 * PDT=1Fh none (no FDD connected to the requested logical unit)
914 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
915 (result[0] & 0x1f) == 0x1f) {
916 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
917 "scsi scan: peripheral device type"
918 " of 31, no device added\n"));
919 res = SCSI_SCAN_TARGET_PRESENT;
920 goto out_free_result;
923 res = scsi_add_lun(sdev, result, &bflags);
924 if (res == SCSI_SCAN_LUN_PRESENT) {
925 if (bflags & BLIST_KEY) {
927 scsi_unlock_floptical(sdev, result);
934 if (res == SCSI_SCAN_LUN_PRESENT) {
936 if (scsi_device_get(sdev) == 0) {
939 __scsi_remove_device(sdev);
940 res = SCSI_SCAN_NO_RESPONSE;
944 scsi_destroy_sdev(sdev);
950 * scsi_sequential_lun_scan - sequentially scan a SCSI target
951 * @starget: pointer to target structure to scan
952 * @bflags: black/white list flag for LUN 0
955 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
956 * scanned) to some maximum lun until a LUN is found with no device
957 * attached. Use the bflags to figure out any oddities.
959 * Modifies sdevscan->lun.
961 static void scsi_sequential_lun_scan(struct scsi_target *starget,
962 int bflags, int scsi_level, int rescan)
964 unsigned int sparse_lun, lun, max_dev_lun;
965 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
967 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
968 "%s\n", starget->dev.bus_id));
970 max_dev_lun = min(max_scsi_luns, shost->max_lun);
972 * If this device is known to support sparse multiple units,
973 * override the other settings, and scan all of them. Normally,
974 * SCSI-3 devices should be scanned via the REPORT LUNS.
976 if (bflags & BLIST_SPARSELUN) {
977 max_dev_lun = shost->max_lun;
983 * If less than SCSI_1_CSS, and no special lun scaning, stop
984 * scanning; this matches 2.4 behaviour, but could just be a bug
985 * (to continue scanning a SCSI_1_CSS device).
987 * This test is broken. We might not have any device on lun0 for
988 * a sparselun device, and if that's the case then how would we
989 * know the real scsi_level, eh? It might make sense to just not
990 * scan any SCSI_1 device for non-0 luns, but that check would best
991 * go into scsi_alloc_sdev() and just have it return null when asked
992 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
994 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
995 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1000 * If this device is known to support multiple units, override
1001 * the other settings, and scan all of them.
1003 if (bflags & BLIST_FORCELUN)
1004 max_dev_lun = shost->max_lun;
1006 * REGAL CDC-4X: avoid hang after LUN 4
1008 if (bflags & BLIST_MAX5LUN)
1009 max_dev_lun = min(5U, max_dev_lun);
1011 * Do not scan SCSI-2 or lower device past LUN 7, unless
1014 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1015 max_dev_lun = min(8U, max_dev_lun);
1018 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1019 * until we reach the max, or no LUN is found and we are not
1022 for (lun = 1; lun < max_dev_lun; ++lun)
1023 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1024 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1030 * scsilun_to_int: convert a scsi_lun to an int
1031 * @scsilun: struct scsi_lun to be converted.
1034 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1035 * integer, and return the result. The caller must check for
1036 * truncation before using this function.
1039 * The struct scsi_lun is assumed to be four levels, with each level
1040 * effectively containing a SCSI byte-ordered (big endian) short; the
1041 * addressing bits of each level are ignored (the highest two bits).
1042 * For a description of the LUN format, post SCSI-3 see the SCSI
1043 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1045 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1046 * the integer: 0x0b030a04
1048 static int scsilun_to_int(struct scsi_lun *scsilun)
1054 for (i = 0; i < sizeof(lun); i += 2)
1055 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1056 scsilun->scsi_lun[i + 1]) << (i * 8));
1061 * int_to_scsilun: reverts an int into a scsi_lun
1062 * @int: integer to be reverted
1063 * @scsilun: struct scsi_lun to be set.
1066 * Reverts the functionality of the scsilun_to_int, which packed
1067 * an 8-byte lun value into an int. This routine unpacks the int
1068 * back into the lun value.
1069 * Note: the scsilun_to_int() routine does not truly handle all
1070 * 8bytes of the lun value. This functions restores only as much
1071 * as was set by the routine.
1074 * Given an integer : 0x0b030a04, this function returns a
1075 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1078 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1082 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1084 for (i = 0; i < sizeof(lun); i += 2) {
1085 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1086 scsilun->scsi_lun[i+1] = lun & 0xFF;
1090 EXPORT_SYMBOL(int_to_scsilun);
1093 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1094 * @sdevscan: scan the host, channel, and id of this scsi_device
1097 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
1098 * command, and scan the resulting list of LUNs by calling
1099 * scsi_probe_and_add_lun.
1101 * Modifies sdevscan->lun.
1104 * 0: scan completed (or no memory, so further scanning is futile)
1105 * 1: no report lun scan, or not configured
1107 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1111 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1112 unsigned int length;
1114 unsigned int num_luns;
1115 unsigned int retries;
1117 struct scsi_lun *lunp, *lun_data;
1119 struct scsi_sense_hdr sshdr;
1120 struct scsi_device *sdev;
1121 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1125 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1126 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1127 * support more than 8 LUNs.
1129 if (bflags & BLIST_NOREPORTLUN)
1131 if (starget->scsi_level < SCSI_2 &&
1132 starget->scsi_level != SCSI_UNKNOWN)
1134 if (starget->scsi_level < SCSI_3 &&
1135 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1137 if (bflags & BLIST_NOLUN)
1140 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1141 sdev = scsi_alloc_sdev(starget, 0, NULL);
1144 if (scsi_device_get(sdev))
1148 sprintf(devname, "host %d channel %d id %d",
1149 shost->host_no, sdev->channel, sdev->id);
1152 * Allocate enough to hold the header (the same size as one scsi_lun)
1153 * plus the max number of luns we are requesting.
1155 * Reallocating and trying again (with the exact amount we need)
1156 * would be nice, but then we need to somehow limit the size
1157 * allocated based on the available memory and the limits of
1158 * kmalloc - we don't want a kmalloc() failure of a huge value to
1159 * prevent us from finding any LUNs on this target.
1161 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1162 lun_data = kmalloc(length, GFP_ATOMIC |
1163 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1165 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1169 scsi_cmd[0] = REPORT_LUNS;
1172 * bytes 1 - 5: reserved, set to zero.
1174 memset(&scsi_cmd[1], 0, 5);
1177 * bytes 6 - 9: length of the command.
1179 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1180 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1181 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1182 scsi_cmd[9] = (unsigned char) length & 0xff;
1184 scsi_cmd[10] = 0; /* reserved */
1185 scsi_cmd[11] = 0; /* control */
1188 * We can get a UNIT ATTENTION, for example a power on/reset, so
1189 * retry a few times (like sd.c does for TEST UNIT READY).
1190 * Experience shows some combinations of adapter/devices get at
1191 * least two power on/resets.
1193 * Illegal requests (for devices that do not support REPORT LUNS)
1194 * should come through as a check condition, and will not generate
1197 for (retries = 0; retries < 3; retries++) {
1198 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1199 " REPORT LUNS to %s (try %d)\n", devname,
1202 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1203 lun_data, length, &sshdr,
1204 SCSI_TIMEOUT + 4 * HZ, 3);
1206 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1207 " %s (try %d) result 0x%x\n", result
1208 ? "failed" : "successful", retries, result));
1211 else if (scsi_sense_valid(&sshdr)) {
1212 if (sshdr.sense_key != UNIT_ATTENTION)
1219 * The device probably does not support a REPORT LUN command
1226 * Get the length from the first four bytes of lun_data.
1228 data = (u8 *) lun_data->scsi_lun;
1229 length = ((data[0] << 24) | (data[1] << 16) |
1230 (data[2] << 8) | (data[3] << 0));
1232 num_luns = (length / sizeof(struct scsi_lun));
1233 if (num_luns > max_scsi_report_luns) {
1234 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1235 " of %d luns reported, try increasing"
1236 " max_scsi_report_luns.\n", devname,
1237 max_scsi_report_luns, num_luns);
1238 num_luns = max_scsi_report_luns;
1241 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1242 "scsi scan: REPORT LUN scan\n"));
1245 * Scan the luns in lun_data. The entry at offset 0 is really
1246 * the header, so start at 1 and go up to and including num_luns.
1248 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1249 lun = scsilun_to_int(lunp);
1252 * Check if the unused part of lunp is non-zero, and so
1253 * does not fit in lun.
1255 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1259 * Output an error displaying the LUN in byte order,
1260 * this differs from what linux would print for the
1261 * integer LUN value.
1263 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1264 data = (char *)lunp->scsi_lun;
1265 for (i = 0; i < sizeof(struct scsi_lun); i++)
1266 printk("%02x", data[i]);
1267 printk(" has a LUN larger than currently supported.\n");
1268 } else if (lun > sdev->host->max_lun) {
1269 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1270 " than allowed by the host adapter\n",
1275 res = scsi_probe_and_add_lun(starget,
1276 lun, NULL, NULL, rescan, NULL);
1277 if (res == SCSI_SCAN_NO_RESPONSE) {
1279 * Got some results, but now none, abort.
1281 sdev_printk(KERN_ERR, sdev,
1282 "Unexpected response"
1283 " from lun %d while scanning, scan"
1293 scsi_device_put(sdev);
1294 if (sdev->sdev_state == SDEV_CREATED)
1296 * the sdev we used didn't appear in the report luns scan
1298 scsi_destroy_sdev(sdev);
1302 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1303 uint id, uint lun, void *hostdata)
1305 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1306 struct device *parent = &shost->shost_gendev;
1307 struct scsi_target *starget;
1309 starget = scsi_alloc_target(parent, channel, id);
1311 return ERR_PTR(-ENOMEM);
1313 get_device(&starget->dev);
1314 mutex_lock(&shost->scan_mutex);
1315 if (scsi_host_scan_allowed(shost))
1316 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1317 mutex_unlock(&shost->scan_mutex);
1318 scsi_target_reap(starget);
1319 put_device(&starget->dev);
1323 EXPORT_SYMBOL(__scsi_add_device);
1325 int scsi_add_device(struct Scsi_Host *host, uint channel,
1326 uint target, uint lun)
1328 struct scsi_device *sdev =
1329 __scsi_add_device(host, channel, target, lun, NULL);
1331 return PTR_ERR(sdev);
1333 scsi_device_put(sdev);
1336 EXPORT_SYMBOL(scsi_add_device);
1338 void scsi_rescan_device(struct device *dev)
1340 struct scsi_driver *drv;
1345 drv = to_scsi_driver(dev->driver);
1346 if (try_module_get(drv->owner)) {
1349 module_put(drv->owner);
1352 EXPORT_SYMBOL(scsi_rescan_device);
1354 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1355 unsigned int id, unsigned int lun, int rescan)
1357 struct Scsi_Host *shost = dev_to_shost(parent);
1360 struct scsi_target *starget;
1362 if (shost->this_id == id)
1364 * Don't scan the host adapter
1368 starget = scsi_alloc_target(parent, channel, id);
1372 get_device(&starget->dev);
1373 if (lun != SCAN_WILD_CARD) {
1375 * Scan for a specific host/chan/id/lun.
1377 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1382 * Scan LUN 0, if there is some response, scan further. Ideally, we
1383 * would not configure LUN 0 until all LUNs are scanned.
1385 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1386 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1387 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1389 * The REPORT LUN did not scan the target,
1390 * do a sequential scan.
1392 scsi_sequential_lun_scan(starget, bflags,
1393 starget->scsi_level, rescan);
1397 /* now determine if the target has any children at all
1398 * and if not, nuke it */
1399 scsi_target_reap(starget);
1401 put_device(&starget->dev);
1405 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1407 * @parent: host to scan
1408 * @channel: channel to scan
1409 * @id: target id to scan
1410 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1411 * @rescan: passed to LUN scanning routines
1414 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1415 * and possibly all LUNs on the target id.
1417 * First try a REPORT LUN scan, if that does not scan the target, do a
1418 * sequential scan of LUNs on the target id.
1420 void scsi_scan_target(struct device *parent, unsigned int channel,
1421 unsigned int id, unsigned int lun, int rescan)
1423 struct Scsi_Host *shost = dev_to_shost(parent);
1425 mutex_lock(&shost->scan_mutex);
1426 if (scsi_host_scan_allowed(shost))
1427 __scsi_scan_target(parent, channel, id, lun, rescan);
1428 mutex_unlock(&shost->scan_mutex);
1430 EXPORT_SYMBOL(scsi_scan_target);
1432 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1433 unsigned int id, unsigned int lun, int rescan)
1437 if (id == SCAN_WILD_CARD)
1438 for (id = 0; id < shost->max_id; ++id) {
1440 * XXX adapter drivers when possible (FCP, iSCSI)
1441 * could modify max_id to match the current max,
1442 * not the absolute max.
1444 * XXX add a shost id iterator, so for example,
1445 * the FC ID can be the same as a target id
1446 * without a huge overhead of sparse id's.
1448 if (shost->reverse_ordering)
1450 * Scan from high to low id.
1452 order_id = shost->max_id - id - 1;
1455 __scsi_scan_target(&shost->shost_gendev, channel,
1456 order_id, lun, rescan);
1459 __scsi_scan_target(&shost->shost_gendev, channel,
1463 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1464 unsigned int id, unsigned int lun, int rescan)
1466 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1468 __FUNCTION__, channel, id, lun));
1470 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1471 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1472 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1475 mutex_lock(&shost->scan_mutex);
1476 if (scsi_host_scan_allowed(shost)) {
1477 if (channel == SCAN_WILD_CARD)
1478 for (channel = 0; channel <= shost->max_channel;
1480 scsi_scan_channel(shost, channel, id, lun,
1483 scsi_scan_channel(shost, channel, id, lun, rescan);
1485 mutex_unlock(&shost->scan_mutex);
1491 * scsi_scan_host - scan the given adapter
1492 * @shost: adapter to scan
1494 void scsi_scan_host(struct Scsi_Host *shost)
1496 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1499 EXPORT_SYMBOL(scsi_scan_host);
1501 void scsi_forget_host(struct Scsi_Host *shost)
1503 struct scsi_device *sdev;
1504 unsigned long flags;
1507 spin_lock_irqsave(shost->host_lock, flags);
1508 list_for_each_entry(sdev, &shost->__devices, siblings) {
1509 if (sdev->sdev_state == SDEV_DEL)
1511 spin_unlock_irqrestore(shost->host_lock, flags);
1512 __scsi_remove_device(sdev);
1515 spin_unlock_irqrestore(shost->host_lock, flags);
1519 * Function: scsi_get_host_dev()
1521 * Purpose: Create a scsi_device that points to the host adapter itself.
1523 * Arguments: SHpnt - Host that needs a scsi_device
1525 * Lock status: None assumed.
1527 * Returns: The scsi_device or NULL
1530 * Attach a single scsi_device to the Scsi_Host - this should
1531 * be made to look like a "pseudo-device" that points to the
1534 * Note - this device is not accessible from any high-level
1535 * drivers (including generics), which is probably not
1536 * optimal. We can add hooks later to attach
1538 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1540 struct scsi_device *sdev = NULL;
1541 struct scsi_target *starget;
1543 mutex_lock(&shost->scan_mutex);
1544 if (!scsi_host_scan_allowed(shost))
1546 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1550 sdev = scsi_alloc_sdev(starget, 0, NULL);
1552 sdev->sdev_gendev.parent = get_device(&starget->dev);
1555 put_device(&starget->dev);
1557 mutex_unlock(&shost->scan_mutex);
1560 EXPORT_SYMBOL(scsi_get_host_dev);
1563 * Function: scsi_free_host_dev()
1565 * Purpose: Free a scsi_device that points to the host adapter itself.
1567 * Arguments: SHpnt - Host that needs a scsi_device
1569 * Lock status: None assumed.
1575 void scsi_free_host_dev(struct scsi_device *sdev)
1577 BUG_ON(sdev->id != sdev->host->this_id);
1579 scsi_destroy_sdev(sdev);
1581 EXPORT_SYMBOL(scsi_free_host_dev);