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>
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 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 * @sreq: used to send the command
114 * @result: area to store the result of the MODE SENSE
117 * Send a vendor specific MODE SENSE (not a MODE SELECT) command using
118 * @sreq to unlock a device, storing the (unused) results into result.
119 * Called for BLIST_KEY devices.
121 static void scsi_unlock_floptical(struct scsi_request *sreq,
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 sreq->sr_cmd_len = 0;
134 sreq->sr_data_direction = DMA_FROM_DEVICE;
135 scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
139 * print_inquiry - printk the inquiry information
140 * @inq_result: printk this SCSI INQUIRY
143 * printk the vendor, model, and other information found in the
144 * INQUIRY data in @inq_result.
147 * Remove this, and replace with a hotplug event that logs any
148 * relevant information.
150 static void print_inquiry(unsigned char *inq_result)
154 printk(KERN_NOTICE " Vendor: ");
155 for (i = 8; i < 16; i++)
156 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
157 printk("%c", inq_result[i]);
162 for (i = 16; i < 32; i++)
163 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
164 printk("%c", inq_result[i]);
169 for (i = 32; i < 36; i++)
170 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
171 printk("%c", inq_result[i]);
177 i = inq_result[0] & 0x1f;
179 printk(KERN_NOTICE " Type: %s ",
181 MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] :
183 printk(" ANSI SCSI revision: %02x",
184 inq_result[2] & 0x07);
185 if ((inq_result[2] & 0x07) == 1 && (inq_result[3] & 0x0f) == 1)
192 * scsi_alloc_sdev - allocate and setup a scsi_Device
195 * Allocate, initialize for io, and return a pointer to a scsi_Device.
196 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
197 * adds scsi_Device to the appropriate list.
200 * scsi_Device pointer, or NULL on failure.
202 static struct scsi_device *scsi_alloc_sdev(struct Scsi_Host *shost,
203 uint channel, uint id, uint lun, void *hostdata)
205 struct scsi_device *sdev;
207 int display_failure_msg = 1, ret;
209 sdev = kmalloc(sizeof(*sdev) + shost->transportt->device_size,
214 memset(sdev, 0, sizeof(*sdev));
215 sdev->vendor = scsi_null_device_strs;
216 sdev->model = scsi_null_device_strs;
217 sdev->rev = scsi_null_device_strs;
221 sdev->channel = channel;
222 sdev->sdev_state = SDEV_CREATED;
223 INIT_LIST_HEAD(&sdev->siblings);
224 INIT_LIST_HEAD(&sdev->same_target_siblings);
225 INIT_LIST_HEAD(&sdev->cmd_list);
226 INIT_LIST_HEAD(&sdev->starved_entry);
227 spin_lock_init(&sdev->list_lock);
229 /* usually NULL and set by ->slave_alloc instead */
230 sdev->hostdata = hostdata;
232 /* if the device needs this changing, it may do so in the
233 * slave_configure function */
234 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
237 * Some low level driver could use device->type
242 * Assume that the device will have handshaking problems,
243 * and then fix this field later if it turns out it
248 spin_lock_init(&sdev->sdev_lock);
249 sdev->request_queue = scsi_alloc_queue(sdev);
250 if (!sdev->request_queue)
253 sdev->request_queue->queuedata = sdev;
254 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
256 if (shost->transportt->device_setup) {
257 if (shost->transportt->device_setup(sdev))
261 if (shost->hostt->slave_alloc) {
262 ret = shost->hostt->slave_alloc(sdev);
265 * if LLDD reports slave not present, don't clutter
266 * console with alloc failure messages
269 display_failure_msg = 0;
270 goto out_device_destroy;
274 if (scsi_sysfs_device_initialize(sdev) != 0)
275 goto out_cleanup_slave;
278 /* NOTE: this target initialisation code depends critically on
279 * lun scanning being sequential. */
280 if (scsi_sysfs_target_initialize(sdev))
281 goto out_remove_siblings;
286 spin_lock_irqsave(shost->host_lock, flags);
287 list_del(&sdev->siblings);
288 list_del(&sdev->same_target_siblings);
289 spin_unlock_irqrestore(shost->host_lock, flags);
291 if (shost->hostt->slave_destroy)
292 shost->hostt->slave_destroy(sdev);
294 if (shost->transportt->device_destroy)
295 shost->transportt->device_destroy(sdev);
297 scsi_free_queue(sdev->request_queue);
301 if (display_failure_msg)
302 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
307 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
308 * @sreq: used to send the INQUIRY
309 * @inq_result: area to store the INQUIRY result
310 * @bflags: store any bflags found here
313 * Probe the lun associated with @sreq using a standard SCSI INQUIRY;
315 * If the INQUIRY is successful, sreq->sr_result is zero and: the
316 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
317 * are copied to the Scsi_Device at @sreq->sr_device (sdev);
318 * any flags value is stored in *@bflags.
320 static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
323 struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
324 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
325 int possible_inq_resp_len;
330 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY to host %d"
331 " channel %d id %d lun %d\n", sdev->host->host_no,
332 sdev->channel, sdev->id, sdev->lun));
334 memset(scsi_cmd, 0, 6);
335 scsi_cmd[0] = INQUIRY;
336 scsi_cmd[4] = 36; /* issue conservative alloc_length */
337 sreq->sr_cmd_len = 0;
338 sreq->sr_data_direction = DMA_FROM_DEVICE;
340 memset(inq_result, 0, 36);
341 scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result, 36,
342 HZ/2 + HZ*scsi_inq_timeout, 3);
344 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 1st INQUIRY %s with"
345 " code 0x%x\n", sreq->sr_result ?
346 "failed" : "successful", sreq->sr_result));
349 if (sreq->sr_result) {
350 if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) != 0 &&
351 (sreq->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION &&
352 (sreq->sr_sense_buffer[12] == 0x28 ||
353 sreq->sr_sense_buffer[12] == 0x29) &&
354 sreq->sr_sense_buffer[13] == 0) {
355 /* not-ready to ready transition or power-on - good */
356 /* dpg: bogus? INQUIRY never returns UNIT_ATTENTION */
357 /* Supposedly, but many buggy devices do so anyway */
362 * assume no peripheral if any other sort of error
368 * Get any flags for this device.
370 * XXX add a bflags to Scsi_Device, and replace the corresponding
371 * bit fields in Scsi_Device, so bflags need not be passed as an
374 *bflags |= scsi_get_device_flags(sdev, &inq_result[8], &inq_result[16]);
376 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
377 if (BLIST_INQUIRY_36 & *bflags)
378 possible_inq_resp_len = 36;
379 else if (BLIST_INQUIRY_58 & *bflags)
380 possible_inq_resp_len = 58;
381 else if (possible_inq_resp_len > 255)
382 possible_inq_resp_len = 36; /* sanity */
384 if (possible_inq_resp_len > 36) { /* do additional INQUIRY */
385 memset(scsi_cmd, 0, 6);
386 scsi_cmd[0] = INQUIRY;
387 scsi_cmd[4] = (unsigned char) possible_inq_resp_len;
388 sreq->sr_cmd_len = 0;
389 sreq->sr_data_direction = DMA_FROM_DEVICE;
391 * re-zero inq_result just to be safe.
393 memset(inq_result, 0, possible_inq_resp_len);
394 scsi_wait_req(sreq, (void *) scsi_cmd,
396 possible_inq_resp_len, (1+scsi_inq_timeout)*(HZ/2), 3);
397 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 2nd INQUIRY"
398 " %s with code 0x%x\n", sreq->sr_result ?
399 "failed" : "successful", sreq->sr_result));
400 if (sreq->sr_result) {
401 /* if the longer inquiry has failed, flag the device
402 * as only accepting 36 byte inquiries and retry the
404 printk(KERN_INFO "scsi scan: %d byte inquiry failed"
405 " with code %d. Consider BLIST_INQUIRY_36 for"
406 " this device\n", possible_inq_resp_len,
408 *bflags = BLIST_INQUIRY_36;
413 * The INQUIRY can change, this means the length can change.
415 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
416 if (BLIST_INQUIRY_58 & *bflags)
417 possible_inq_resp_len = 58;
418 else if (possible_inq_resp_len > 255)
419 possible_inq_resp_len = 36; /* sanity */
422 sdev->inquiry_len = possible_inq_resp_len;
425 * XXX Abort if the response length is less than 36? If less than
426 * 32, the lookup of the device flags (above) could be invalid,
427 * and it would be possible to take an incorrect action - we do
428 * not want to hang because of a short INQUIRY. On the flip side,
429 * if the device is spun down or becoming ready (and so it gives a
430 * short INQUIRY), an abort here prevents any further use of the
431 * device, including spin up.
433 * Related to the above issue:
435 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
436 * and if not ready, sent a START_STOP to start (maybe spin up) and
437 * then send the INQUIRY again, since the INQUIRY can change after
438 * a device is initialized.
440 * Ideally, start a device if explicitly asked to do so. This
441 * assumes that a device is spun up on power on, spun down on
442 * request, and then spun up on request.
446 * The scanning code needs to know the scsi_level, even if no
447 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
448 * non-zero LUNs can be scanned.
450 sdev->scsi_level = inq_result[2] & 0x07;
451 if (sdev->scsi_level >= 2 ||
452 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
459 * scsi_add_lun - allocate and fully initialze a Scsi_Device
460 * @sdevscan: holds information to be stored in the new Scsi_Device
461 * @sdevnew: store the address of the newly allocated Scsi_Device
462 * @inq_result: holds the result of a previous INQUIRY to the LUN
463 * @bflags: black/white list flag
466 * Allocate and initialize a Scsi_Device matching sdevscan. Optionally
467 * set fields based on values in *@bflags. If @sdevnew is not
468 * NULL, store the address of the new Scsi_Device in *@sdevnew (needed
469 * when scanning a particular LUN).
472 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
473 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
475 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
478 * XXX do not save the inquiry, since it can change underneath us,
479 * save just vendor/model/rev.
481 * Rather than save it and have an ioctl that retrieves the saved
482 * value, have an ioctl that executes the same INQUIRY code used
483 * in scsi_probe_lun, let user level programs doing INQUIRY
484 * scanning run at their own risk, or supply a user level program
485 * that can correctly scan.
487 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
488 if (sdev->inquiry == NULL) {
489 return SCSI_SCAN_NO_RESPONSE;
492 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
493 sdev->vendor = (char *) (sdev->inquiry + 8);
494 sdev->model = (char *) (sdev->inquiry + 16);
495 sdev->rev = (char *) (sdev->inquiry + 32);
497 if (*bflags & BLIST_ISROM) {
499 * It would be better to modify sdev->type, and set
500 * sdev->removable, but then the print_inquiry() output
501 * would not show TYPE_ROM; if print_inquiry() is removed
502 * the issue goes away.
504 inq_result[0] = TYPE_ROM;
505 inq_result[1] |= 0x80; /* removable */
508 switch (sdev->type = (inq_result[0] & 0x1f)) {
515 case TYPE_MEDIUM_CHANGER:
525 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
528 print_inquiry(inq_result);
531 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
532 * spec says: The device server is capable of supporting the
533 * specified peripheral device type on this logical unit. However,
534 * the physical device is not currently connected to this logical
537 * The above is vague, as it implies that we could treat 001 and
538 * 011 the same. Stay compatible with previous code, and create a
539 * Scsi_Device for a PQ of 1
541 * Don't set the device offline here; rather let the upper
542 * level drivers eval the PQ to decide whether they should
543 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
546 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
547 sdev->removable = (0x80 & inq_result[1]) >> 7;
548 sdev->lockable = sdev->removable;
549 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
551 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
552 inq_result[56] & 0x04))
554 if (inq_result[7] & 0x60)
556 if (inq_result[7] & 0x10)
559 sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
560 sdev->host->host_no, sdev->channel,
561 sdev->id, sdev->lun);
564 * End driverfs/devfs code.
567 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
568 !(*bflags & BLIST_NOTQ))
569 sdev->tagged_supported = 1;
571 * Some devices (Texel CD ROM drives) have handshaking problems
572 * when used with the Seagate controllers. borken is initialized
573 * to 1, and then set it to 0 here.
575 if ((*bflags & BLIST_BORKEN) == 0)
579 * Some devices may not want to have a start command automatically
580 * issued when a device is added.
582 if (*bflags & BLIST_NOSTARTONADD)
583 sdev->no_start_on_add = 1;
585 if (*bflags & BLIST_SINGLELUN)
586 sdev->single_lun = 1;
589 sdev->use_10_for_rw = 1;
591 if (*bflags & BLIST_MS_SKIP_PAGE_08)
592 sdev->skip_ms_page_8 = 1;
594 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
595 sdev->skip_ms_page_3f = 1;
597 if (*bflags & BLIST_USE_10_BYTE_MS)
598 sdev->use_10_for_ms = 1;
600 /* set the device running here so that slave configure
602 scsi_device_set_state(sdev, SDEV_RUNNING);
604 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
605 sdev->use_192_bytes_for_3f = 1;
607 if (*bflags & BLIST_NOT_LOCKABLE)
610 if (sdev->host->transportt->device_configure)
611 sdev->host->transportt->device_configure(sdev);
613 if (sdev->host->hostt->slave_configure)
614 sdev->host->hostt->slave_configure(sdev);
617 * Ok, the device is now all set up, we can
618 * register it and tell the rest of the kernel
621 scsi_sysfs_add_sdev(sdev);
623 return SCSI_SCAN_LUN_PRESENT;
627 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
628 * @sdevscan: probe the LUN corresponding to this Scsi_Device
629 * @sdevnew: store the value of any new Scsi_Device allocated
630 * @bflagsp: store bflags here if not NULL
633 * Call scsi_probe_lun, if a LUN with an attached device is found,
634 * allocate and set it up by calling scsi_add_lun.
637 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
638 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
639 * attached at the LUN
640 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
642 static int scsi_probe_and_add_lun(struct Scsi_Host *host,
643 uint channel, uint id, uint lun, int *bflagsp,
644 struct scsi_device **sdevp, int rescan, void *hostdata)
646 struct scsi_device *sdev;
647 struct scsi_request *sreq;
648 unsigned char *result;
649 int bflags, res = SCSI_SCAN_NO_RESPONSE;
652 * The rescan flag is used as an optimization, the first scan of a
653 * host adapter calls into here with rescan == 0.
656 sdev = scsi_device_lookup(host, channel, id, lun);
658 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
659 "scsi scan: device exists on <%d:%d:%d:%d>\n",
660 host->host_no, channel, id, lun));
664 *bflagsp = scsi_get_device_flags(sdev,
667 /* XXX: bandaid until callers do refcounting */
668 scsi_device_put(sdev);
669 return SCSI_SCAN_LUN_PRESENT;
673 sdev = scsi_alloc_sdev(host, channel, id, lun, hostdata);
676 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
679 result = kmalloc(256, GFP_ATOMIC |
680 (host->unchecked_isa_dma) ? __GFP_DMA : 0);
684 scsi_probe_lun(sreq, result, &bflags);
686 goto out_free_result;
689 * result contains valid SCSI INQUIRY data.
691 if ((result[0] >> 5) == 3) {
693 * For a Peripheral qualifier 3 (011b), the SCSI
694 * spec says: The device server is not capable of
695 * supporting a physical device on this logical
698 * For disks, this implies that there is no
699 * logical disk configured at sdev->lun, but there
700 * is a target id responding.
702 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
703 "scsi scan: peripheral qualifier of 3,"
704 " no device added\n"));
705 res = SCSI_SCAN_TARGET_PRESENT;
706 goto out_free_result;
709 res = scsi_add_lun(sdev, result, &bflags);
710 if (res == SCSI_SCAN_LUN_PRESENT) {
711 if (bflags & BLIST_KEY) {
713 scsi_unlock_floptical(sreq, result);
722 scsi_release_request(sreq);
724 if (res == SCSI_SCAN_LUN_PRESENT) {
728 if (sdev->host->hostt->slave_destroy)
729 sdev->host->hostt->slave_destroy(sdev);
730 if (sdev->host->transportt->device_destroy)
731 sdev->host->transportt->device_destroy(sdev);
732 put_device(&sdev->sdev_gendev);
739 * scsi_sequential_lun_scan - sequentially scan a SCSI target
740 * @sdevscan: scan the host, channel, and id of this Scsi_Device
741 * @bflags: black/white list flag for LUN 0
742 * @lun0_res: result of scanning LUN 0
745 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
746 * scanned) to some maximum lun until a LUN is found with no device
747 * attached. Use the bflags to figure out any oddities.
749 * Modifies sdevscan->lun.
751 static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
752 uint id, int bflags, int lun0_res, int scsi_level, int rescan)
754 unsigned int sparse_lun, lun, max_dev_lun;
756 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
757 " host %d channel %d id %d\n", shost->host_no,
760 max_dev_lun = min(max_scsi_luns, shost->max_lun);
762 * If this device is known to support sparse multiple units,
763 * override the other settings, and scan all of them. Normally,
764 * SCSI-3 devices should be scanned via the REPORT LUNS.
766 if (bflags & BLIST_SPARSELUN) {
767 max_dev_lun = shost->max_lun;
773 * If not sparse lun and no device attached at LUN 0 do not scan
776 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
780 * If less than SCSI_1_CSS, and no special lun scaning, stop
781 * scanning; this matches 2.4 behaviour, but could just be a bug
782 * (to continue scanning a SCSI_1_CSS device).
784 * This test is broken. We might not have any device on lun0 for
785 * a sparselun device, and if that's the case then how would we
786 * know the real scsi_level, eh? It might make sense to just not
787 * scan any SCSI_1 device for non-0 luns, but that check would best
788 * go into scsi_alloc_sdev() and just have it return null when asked
789 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
791 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
792 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
797 * If this device is known to support multiple units, override
798 * the other settings, and scan all of them.
800 if (bflags & BLIST_FORCELUN)
801 max_dev_lun = shost->max_lun;
803 * REGAL CDC-4X: avoid hang after LUN 4
805 if (bflags & BLIST_MAX5LUN)
806 max_dev_lun = min(5U, max_dev_lun);
808 * Do not scan SCSI-2 or lower device past LUN 7, unless
811 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
812 max_dev_lun = min(8U, max_dev_lun);
815 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
816 * until we reach the max, or no LUN is found and we are not
819 for (lun = 1; lun < max_dev_lun; ++lun)
820 if ((scsi_probe_and_add_lun(shost, channel, id, lun,
821 NULL, NULL, rescan, NULL) != SCSI_SCAN_LUN_PRESENT) &&
827 * scsilun_to_int: convert a scsi_lun to an int
828 * @scsilun: struct scsi_lun to be converted.
831 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
832 * integer, and return the result. The caller must check for
833 * truncation before using this function.
836 * The struct scsi_lun is assumed to be four levels, with each level
837 * effectively containing a SCSI byte-ordered (big endian) short; the
838 * addressing bits of each level are ignored (the highest two bits).
839 * For a description of the LUN format, post SCSI-3 see the SCSI
840 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
842 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
843 * the integer: 0x0b030a04
845 static int scsilun_to_int(struct scsi_lun *scsilun)
851 for (i = 0; i < sizeof(lun); i += 2)
852 lun = lun | (((scsilun->scsi_lun[i] << 8) |
853 scsilun->scsi_lun[i + 1]) << (i * 8));
858 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
859 * @sdevscan: scan the host, channel, and id of this Scsi_Device
862 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
863 * command, and scan the resulting list of LUNs by calling
864 * scsi_probe_and_add_lun.
866 * Modifies sdevscan->lun.
869 * 0: scan completed (or no memory, so further scanning is futile)
870 * 1: no report lun scan, or not configured
872 static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
876 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
879 unsigned int num_luns;
880 unsigned int retries;
881 struct scsi_lun *lunp, *lun_data;
882 struct scsi_request *sreq;
886 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
887 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
888 * support more than 8 LUNs.
890 if ((bflags & BLIST_NOREPORTLUN) ||
891 sdev->scsi_level < SCSI_2 ||
892 (sdev->scsi_level < SCSI_3 &&
893 (!(bflags & BLIST_REPORTLUN2) || sdev->host->max_lun <= 8)) )
895 if (bflags & BLIST_NOLUN)
898 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
902 sprintf(devname, "host %d channel %d id %d",
903 sdev->host->host_no, sdev->channel, sdev->id);
906 * Allocate enough to hold the header (the same size as one scsi_lun)
907 * plus the max number of luns we are requesting.
909 * Reallocating and trying again (with the exact amount we need)
910 * would be nice, but then we need to somehow limit the size
911 * allocated based on the available memory and the limits of
912 * kmalloc - we don't want a kmalloc() failure of a huge value to
913 * prevent us from finding any LUNs on this target.
915 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
916 lun_data = kmalloc(length, GFP_ATOMIC |
917 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
919 goto out_release_request;
921 scsi_cmd[0] = REPORT_LUNS;
924 * bytes 1 - 5: reserved, set to zero.
926 memset(&scsi_cmd[1], 0, 5);
929 * bytes 6 - 9: length of the command.
931 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
932 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
933 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
934 scsi_cmd[9] = (unsigned char) length & 0xff;
936 scsi_cmd[10] = 0; /* reserved */
937 scsi_cmd[11] = 0; /* control */
938 sreq->sr_cmd_len = 0;
939 sreq->sr_data_direction = DMA_FROM_DEVICE;
942 * We can get a UNIT ATTENTION, for example a power on/reset, so
943 * retry a few times (like sd.c does for TEST UNIT READY).
944 * Experience shows some combinations of adapter/devices get at
945 * least two power on/resets.
947 * Illegal requests (for devices that do not support REPORT LUNS)
948 * should come through as a check condition, and will not generate
951 for (retries = 0; retries < 3; retries++) {
952 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
953 " REPORT LUNS to %s (try %d)\n", devname,
955 scsi_wait_req(sreq, scsi_cmd, lun_data, length,
956 SCSI_TIMEOUT + 4*HZ, 3);
957 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
958 " %s (try %d) result 0x%x\n", sreq->sr_result
959 ? "failed" : "successful", retries,
961 if (sreq->sr_result == 0 ||
962 sreq->sr_sense_buffer[2] != UNIT_ATTENTION)
966 if (sreq->sr_result) {
968 * The device probably does not support a REPORT LUN command
971 scsi_release_request(sreq);
974 scsi_release_request(sreq);
977 * Get the length from the first four bytes of lun_data.
979 data = (u8 *) lun_data->scsi_lun;
980 length = ((data[0] << 24) | (data[1] << 16) |
981 (data[2] << 8) | (data[3] << 0));
983 num_luns = (length / sizeof(struct scsi_lun));
984 if (num_luns > max_scsi_report_luns) {
985 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
986 " of %d luns reported, try increasing"
987 " max_scsi_report_luns.\n", devname,
988 max_scsi_report_luns, num_luns);
989 num_luns = max_scsi_report_luns;
992 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUN scan of"
993 " host %d channel %d id %d\n", sdev->host->host_no,
994 sdev->channel, sdev->id));
997 * Scan the luns in lun_data. The entry at offset 0 is really
998 * the header, so start at 1 and go up to and including num_luns.
1000 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1001 lun = scsilun_to_int(lunp);
1004 * Check if the unused part of lunp is non-zero, and so
1005 * does not fit in lun.
1007 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1011 * Output an error displaying the LUN in byte order,
1012 * this differs from what linux would print for the
1013 * integer LUN value.
1015 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1016 data = (char *)lunp->scsi_lun;
1017 for (i = 0; i < sizeof(struct scsi_lun); i++)
1018 printk("%02x", data[i]);
1019 printk(" has a LUN larger than currently supported.\n");
1020 } else if (lun == 0) {
1022 * LUN 0 has already been scanned.
1024 } else if (lun > sdev->host->max_lun) {
1025 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1026 " than allowed by the host adapter\n",
1031 res = scsi_probe_and_add_lun(sdev->host, sdev->channel,
1032 sdev->id, lun, NULL, NULL, rescan, NULL);
1033 if (res == SCSI_SCAN_NO_RESPONSE) {
1035 * Got some results, but now none, abort.
1037 printk(KERN_ERR "scsi: Unexpected response"
1038 " from %s lun %d while scanning, scan"
1039 " aborted\n", devname, lun);
1048 out_release_request:
1049 scsi_release_request(sreq);
1052 * We are out of memory, don't try scanning any further.
1054 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1058 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1059 uint id, uint lun, void *hostdata)
1061 struct scsi_device *sdev;
1064 down(&shost->scan_mutex);
1065 res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL,
1066 &sdev, 1, hostdata);
1067 if (res != SCSI_SCAN_LUN_PRESENT)
1068 sdev = ERR_PTR(-ENODEV);
1069 up(&shost->scan_mutex);
1074 void scsi_rescan_device(struct device *dev)
1076 struct scsi_driver *drv;
1081 drv = to_scsi_driver(dev->driver);
1082 if (try_module_get(drv->owner)) {
1085 module_put(drv->owner);
1090 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1092 * @sdevsca: Scsi_Device handle for scanning
1093 * @shost: host to scan
1094 * @channel: channel to scan
1095 * @id: target id to scan
1098 * Scan the target id on @shost, @channel, and @id. Scan at least LUN
1099 * 0, and possibly all LUNs on the target id.
1101 * Use the pre-allocated @sdevscan as a handle for the scanning. This
1102 * function sets sdevscan->host, sdevscan->id and sdevscan->lun; the
1103 * scanning functions modify sdevscan->lun.
1105 * First try a REPORT LUN scan, if that does not scan the target, do a
1106 * sequential scan of LUNs on the target id.
1108 static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
1109 unsigned int id, unsigned int lun, int rescan)
1113 struct scsi_device *sdev;
1115 if (shost->this_id == id)
1117 * Don't scan the host adapter
1121 if (lun != SCAN_WILD_CARD) {
1123 * Scan for a specific host/chan/id/lun.
1125 scsi_probe_and_add_lun(shost, channel, id, lun, NULL, NULL,
1131 * Scan LUN 0, if there is some response, scan further. Ideally, we
1132 * would not configure LUN 0 until all LUNs are scanned.
1134 res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev,
1136 if (res == SCSI_SCAN_LUN_PRESENT) {
1137 if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
1139 * The REPORT LUN did not scan the target,
1140 * do a sequential scan.
1142 scsi_sequential_lun_scan(shost, channel, id, bflags,
1143 res, sdev->scsi_level, rescan);
1144 } else if (res == SCSI_SCAN_TARGET_PRESENT) {
1146 * There's a target here, but lun 0 is offline so we
1147 * can't use the report_lun scan. Fall back to a
1148 * sequential lun scan with a bflags of SPARSELUN and
1149 * a default scsi level of SCSI_2
1151 scsi_sequential_lun_scan(shost, channel, id, BLIST_SPARSELUN,
1152 SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
1156 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1157 unsigned int id, unsigned int lun, int rescan)
1161 if (id == SCAN_WILD_CARD)
1162 for (id = 0; id < shost->max_id; ++id) {
1164 * XXX adapter drivers when possible (FCP, iSCSI)
1165 * could modify max_id to match the current max,
1166 * not the absolute max.
1168 * XXX add a shost id iterator, so for example,
1169 * the FC ID can be the same as a target id
1170 * without a huge overhead of sparse id's.
1172 if (shost->reverse_ordering)
1174 * Scan from high to low id.
1176 order_id = shost->max_id - id - 1;
1179 scsi_scan_target(shost, channel, order_id, lun, rescan);
1182 scsi_scan_target(shost, channel, id, lun, rescan);
1185 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1186 unsigned int id, unsigned int lun, int rescan)
1188 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
1189 __FUNCTION__, shost->host_no, channel, id, lun));
1191 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1192 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1193 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1196 down(&shost->scan_mutex);
1197 if (channel == SCAN_WILD_CARD)
1198 for (channel = 0; channel <= shost->max_channel; channel++)
1199 scsi_scan_channel(shost, channel, id, lun, rescan);
1201 scsi_scan_channel(shost, channel, id, lun, rescan);
1202 up(&shost->scan_mutex);
1208 * scsi_scan_host - scan the given adapter
1209 * @shost: adapter to scan
1211 void scsi_scan_host(struct Scsi_Host *shost)
1213 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1217 void scsi_forget_host(struct Scsi_Host *shost)
1219 struct scsi_device *sdev, *tmp;
1220 unsigned long flags;
1223 * Ok, this look a bit strange. We always look for the first device
1224 * on the list as scsi_remove_device removes them from it - thus we
1225 * also have to release the lock.
1226 * We don't need to get another reference to the device before
1227 * releasing the lock as we already own the reference from
1228 * scsi_register_device that's release in scsi_remove_device. And
1229 * after that we don't look at sdev anymore.
1231 spin_lock_irqsave(shost->host_lock, flags);
1232 list_for_each_entry_safe(sdev, tmp, &shost->__devices, siblings) {
1233 spin_unlock_irqrestore(shost->host_lock, flags);
1234 scsi_remove_device(sdev);
1235 spin_lock_irqsave(shost->host_lock, flags);
1237 spin_unlock_irqrestore(shost->host_lock, flags);
1241 * Function: scsi_get_host_dev()
1243 * Purpose: Create a Scsi_Device that points to the host adapter itself.
1245 * Arguments: SHpnt - Host that needs a Scsi_Device
1247 * Lock status: None assumed.
1249 * Returns: The Scsi_Device or NULL
1252 * Attach a single Scsi_Device to the Scsi_Host - this should
1253 * be made to look like a "pseudo-device" that points to the
1256 * Note - this device is not accessible from any high-level
1257 * drivers (including generics), which is probably not
1258 * optimal. We can add hooks later to attach
1260 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1262 struct scsi_device *sdev;
1264 sdev = scsi_alloc_sdev(shost, 0, shost->this_id, 0, NULL);
1272 * Function: scsi_free_host_dev()
1274 * Purpose: Free a scsi_device that points to the host adapter itself.
1276 * Arguments: SHpnt - Host that needs a Scsi_Device
1278 * Lock status: None assumed.
1284 void scsi_free_host_dev(struct scsi_device *sdev)
1286 BUG_ON(sdev->id != sdev->host->this_id);
1288 if (sdev->host->hostt->slave_destroy)
1289 sdev->host->hostt->slave_destroy(sdev);
1290 if (sdev->host->transportt->device_destroy)
1291 sdev->host->transportt->device_destroy(sdev);
1292 put_device(&sdev->sdev_gendev);