4 * Copyright (C) 2000 Eric Youngdale,
5 * Copyright (C) 2002 Patrick Mansfield
7 * The general scanning/probing algorithm is as follows, exceptions are
8 * made to it depending on device specific flags, compilation options, and
9 * global variable (boot or module load time) settings.
11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
12 * device attached, a Scsi_Device is allocated and setup for it.
14 * For every id of every channel on the given host:
16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
17 * device or storage attached to LUN 0):
19 * If LUN 0 has a device attached, allocate and setup a
22 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
23 * all of the LUNs returned by the REPORT LUN; else,
24 * sequentially scan LUNs up until some maximum is reached,
25 * or a LUN is seen that cannot have a device attached to it.
28 #include <linux/config.h>
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/init.h>
32 #include <linux/blkdev.h>
33 #include <asm/semaphore.h>
35 #include <scsi/scsi.h>
36 #include <scsi/scsi_device.h>
37 #include <scsi/scsi_driver.h>
38 #include <scsi/scsi_devinfo.h>
39 #include <scsi/scsi_host.h>
40 #include <scsi/scsi_request.h>
41 #include <scsi/scsi_transport.h>
42 #include <scsi/scsi_eh.h>
44 #include "scsi_priv.h"
45 #include "scsi_logging.h"
47 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
48 " SCSI scanning, some SCSI devices might not be configured\n"
53 #define SCSI_TIMEOUT (2*HZ)
56 * Prefix values for the SCSI id's (stored in driverfs name field)
58 #define SCSI_UID_SER_NUM 'S'
59 #define SCSI_UID_UNKNOWN 'Z'
62 * Return values of some of the scanning functions.
64 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
65 * includes allocation or general failures preventing IO from being sent.
67 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
70 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
73 #define SCSI_SCAN_NO_RESPONSE 0
74 #define SCSI_SCAN_TARGET_PRESENT 1
75 #define SCSI_SCAN_LUN_PRESENT 2
77 static char *scsi_null_device_strs = "nullnullnullnull";
79 #define MAX_SCSI_LUNS 512
81 #ifdef CONFIG_SCSI_MULTI_LUN
82 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
84 static unsigned int max_scsi_luns = 1;
87 module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR);
88 MODULE_PARM_DESC(max_luns,
89 "last scsi LUN (should be between 1 and 2^32-1)");
92 * max_scsi_report_luns: the maximum number of LUNS that will be
93 * returned from the REPORT LUNS command. 8 times this value must
94 * be allocated. In theory this could be up to an 8 byte value, but
95 * in practice, the maximum number of LUNs suppored by any device
98 static unsigned int max_scsi_report_luns = 511;
100 module_param_named(max_report_luns, max_scsi_report_luns, int, S_IRUGO|S_IWUSR);
101 MODULE_PARM_DESC(max_report_luns,
102 "REPORT LUNS maximum number of LUNS received (should be"
103 " between 1 and 16384)");
105 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
107 module_param_named(inq_timeout, scsi_inq_timeout, int, S_IRUGO|S_IWUSR);
108 MODULE_PARM_DESC(inq_timeout,
109 "Timeout (in seconds) waiting for devices to answer INQUIRY."
110 " Default is 5. Some non-compliant devices need more.");
113 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
114 * @sreq: used to send the command
115 * @result: area to store the result of the MODE SENSE
118 * Send a vendor specific MODE SENSE (not a MODE SELECT) command using
119 * @sreq to unlock a device, storing the (unused) results into result.
120 * Called for BLIST_KEY devices.
122 static void scsi_unlock_floptical(struct scsi_request *sreq,
123 unsigned char *result)
125 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
127 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
128 scsi_cmd[0] = MODE_SENSE;
132 scsi_cmd[4] = 0x2a; /* size */
134 sreq->sr_cmd_len = 0;
135 sreq->sr_data_direction = DMA_FROM_DEVICE;
136 scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
140 * print_inquiry - printk the inquiry information
141 * @inq_result: printk this SCSI INQUIRY
144 * printk the vendor, model, and other information found in the
145 * INQUIRY data in @inq_result.
148 * Remove this, and replace with a hotplug event that logs any
149 * relevant information.
151 static void print_inquiry(unsigned char *inq_result)
155 printk(KERN_NOTICE " Vendor: ");
156 for (i = 8; i < 16; i++)
157 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
158 printk("%c", inq_result[i]);
163 for (i = 16; i < 32; i++)
164 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
165 printk("%c", inq_result[i]);
170 for (i = 32; i < 36; i++)
171 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
172 printk("%c", inq_result[i]);
178 i = inq_result[0] & 0x1f;
180 printk(KERN_NOTICE " Type: %s ",
182 MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] :
184 printk(" ANSI SCSI revision: %02x",
185 inq_result[2] & 0x07);
186 if ((inq_result[2] & 0x07) == 1 && (inq_result[3] & 0x0f) == 1)
193 * scsi_alloc_sdev - allocate and setup a scsi_Device
196 * Allocate, initialize for io, and return a pointer to a scsi_Device.
197 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
198 * adds scsi_Device to the appropriate list.
201 * scsi_Device pointer, or NULL on failure.
203 static struct scsi_device *scsi_alloc_sdev(struct Scsi_Host *shost,
204 uint channel, uint id, uint lun, void *hostdata)
206 struct scsi_device *sdev;
208 int display_failure_msg = 1, ret;
210 sdev = kmalloc(sizeof(*sdev) + shost->transportt->device_size,
215 memset(sdev, 0, sizeof(*sdev));
216 sdev->vendor = scsi_null_device_strs;
217 sdev->model = scsi_null_device_strs;
218 sdev->rev = scsi_null_device_strs;
222 sdev->channel = channel;
223 sdev->sdev_state = SDEV_CREATED;
224 INIT_LIST_HEAD(&sdev->siblings);
225 INIT_LIST_HEAD(&sdev->same_target_siblings);
226 INIT_LIST_HEAD(&sdev->cmd_list);
227 INIT_LIST_HEAD(&sdev->starved_entry);
228 spin_lock_init(&sdev->list_lock);
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 spin_lock_init(&sdev->sdev_lock);
250 sdev->request_queue = scsi_alloc_queue(sdev);
251 if (!sdev->request_queue)
254 sdev->request_queue->queuedata = sdev;
255 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
257 scsi_sysfs_device_initialize(sdev);
259 if (shost->hostt->slave_alloc) {
260 ret = shost->hostt->slave_alloc(sdev);
263 * if LLDD reports slave not present, don't clutter
264 * console with alloc failure messages
267 display_failure_msg = 0;
268 goto out_device_destroy;
272 /* NOTE: this target initialisation code depends critically on
273 * lun scanning being sequential. */
274 if (scsi_sysfs_target_initialize(sdev))
275 goto out_remove_siblings;
280 spin_lock_irqsave(shost->host_lock, flags);
281 list_del(&sdev->siblings);
282 list_del(&sdev->same_target_siblings);
283 spin_unlock_irqrestore(shost->host_lock, flags);
285 if (shost->hostt->slave_destroy)
286 shost->hostt->slave_destroy(sdev);
288 transport_destroy_device(&sdev->sdev_gendev);
289 scsi_free_queue(sdev->request_queue);
293 if (display_failure_msg)
294 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
299 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
300 * @sreq: used to send the INQUIRY
301 * @inq_result: area to store the INQUIRY result
302 * @bflags: store any bflags found here
305 * Probe the lun associated with @sreq using a standard SCSI INQUIRY;
307 * If the INQUIRY is successful, sreq->sr_result is zero and: the
308 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
309 * are copied to the Scsi_Device at @sreq->sr_device (sdev);
310 * any flags value is stored in *@bflags.
312 static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
315 struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
316 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
317 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
318 int response_len = 0;
320 struct scsi_sense_hdr sshdr;
324 /* Perform up to 3 passes. The first pass uses a conservative
325 * transfer length of 36 unless sdev->inquiry_len specifies a
326 * different value. */
327 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
328 try_inquiry_len = first_inquiry_len;
332 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY pass %d "
333 "to host %d channel %d id %d lun %d, length %d\n",
334 pass, sdev->host->host_no, sdev->channel,
335 sdev->id, sdev->lun, try_inquiry_len));
337 /* Each pass gets up to three chances to ignore Unit Attention */
338 for (count = 0; count < 3; ++count) {
339 memset(scsi_cmd, 0, 6);
340 scsi_cmd[0] = INQUIRY;
341 scsi_cmd[4] = (unsigned char) try_inquiry_len;
342 sreq->sr_cmd_len = 0;
343 sreq->sr_data_direction = DMA_FROM_DEVICE;
345 memset(inq_result, 0, try_inquiry_len);
346 scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result,
348 HZ/2 + HZ*scsi_inq_timeout, 3);
350 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
352 sreq->sr_result ? "failed" : "successful",
355 if (sreq->sr_result) {
357 * not-ready to ready transition [asc/ascq=0x28/0x0]
358 * or power-on, reset [asc/ascq=0x29/0x0], continue.
359 * INQUIRY should not yield UNIT_ATTENTION
360 * but many buggy devices do so anyway.
362 if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
363 scsi_request_normalize_sense(sreq, &sshdr)) {
364 if ((sshdr.sense_key == UNIT_ATTENTION) &&
365 ((sshdr.asc == 0x28) ||
366 (sshdr.asc == 0x29)) &&
374 if (sreq->sr_result == 0) {
375 response_len = (unsigned char) inq_result[4] + 5;
376 if (response_len > 255)
377 response_len = first_inquiry_len; /* sanity */
380 * Get any flags for this device.
382 * XXX add a bflags to Scsi_Device, and replace the
383 * corresponding bit fields in Scsi_Device, so bflags
384 * need not be passed as an argument.
386 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
389 /* When the first pass succeeds we gain information about
390 * what larger transfer lengths might work. */
392 if (BLIST_INQUIRY_36 & *bflags)
393 next_inquiry_len = 36;
394 else if (BLIST_INQUIRY_58 & *bflags)
395 next_inquiry_len = 58;
396 else if (sdev->inquiry_len)
397 next_inquiry_len = sdev->inquiry_len;
399 next_inquiry_len = response_len;
401 /* If more data is available perform the second pass */
402 if (next_inquiry_len > try_inquiry_len) {
403 try_inquiry_len = next_inquiry_len;
409 } else if (pass == 2) {
410 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
411 "Consider BLIST_INQUIRY_36 for this device\n",
414 /* If this pass failed, the third pass goes back and transfers
415 * the same amount as we successfully got in the first pass. */
416 try_inquiry_len = first_inquiry_len;
421 /* If the last transfer attempt got an error, assume the
422 * peripheral doesn't exist or is dead. */
426 /* Don't report any more data than the device says is valid */
427 sdev->inquiry_len = min(try_inquiry_len, response_len);
430 * XXX Abort if the response length is less than 36? If less than
431 * 32, the lookup of the device flags (above) could be invalid,
432 * and it would be possible to take an incorrect action - we do
433 * not want to hang because of a short INQUIRY. On the flip side,
434 * if the device is spun down or becoming ready (and so it gives a
435 * short INQUIRY), an abort here prevents any further use of the
436 * device, including spin up.
438 * Related to the above issue:
440 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
441 * and if not ready, sent a START_STOP to start (maybe spin up) and
442 * then send the INQUIRY again, since the INQUIRY can change after
443 * a device is initialized.
445 * Ideally, start a device if explicitly asked to do so. This
446 * assumes that a device is spun up on power on, spun down on
447 * request, and then spun up on request.
451 * The scanning code needs to know the scsi_level, even if no
452 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
453 * non-zero LUNs can be scanned.
455 sdev->scsi_level = inq_result[2] & 0x07;
456 if (sdev->scsi_level >= 2 ||
457 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
464 * scsi_add_lun - allocate and fully initialze a Scsi_Device
465 * @sdevscan: holds information to be stored in the new Scsi_Device
466 * @sdevnew: store the address of the newly allocated Scsi_Device
467 * @inq_result: holds the result of a previous INQUIRY to the LUN
468 * @bflags: black/white list flag
471 * Allocate and initialize a Scsi_Device matching sdevscan. Optionally
472 * set fields based on values in *@bflags. If @sdevnew is not
473 * NULL, store the address of the new Scsi_Device in *@sdevnew (needed
474 * when scanning a particular LUN).
477 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
478 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
480 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
483 * XXX do not save the inquiry, since it can change underneath us,
484 * save just vendor/model/rev.
486 * Rather than save it and have an ioctl that retrieves the saved
487 * value, have an ioctl that executes the same INQUIRY code used
488 * in scsi_probe_lun, let user level programs doing INQUIRY
489 * scanning run at their own risk, or supply a user level program
490 * that can correctly scan.
492 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
493 if (sdev->inquiry == NULL) {
494 return SCSI_SCAN_NO_RESPONSE;
497 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
498 sdev->vendor = (char *) (sdev->inquiry + 8);
499 sdev->model = (char *) (sdev->inquiry + 16);
500 sdev->rev = (char *) (sdev->inquiry + 32);
502 if (*bflags & BLIST_ISROM) {
504 * It would be better to modify sdev->type, and set
505 * sdev->removable, but then the print_inquiry() output
506 * would not show TYPE_ROM; if print_inquiry() is removed
507 * the issue goes away.
509 inq_result[0] = TYPE_ROM;
510 inq_result[1] |= 0x80; /* removable */
511 } else if (*bflags & BLIST_NO_ULD_ATTACH)
512 sdev->no_uld_attach = 1;
514 switch (sdev->type = (inq_result[0] & 0x1f)) {
521 case TYPE_MEDIUM_CHANGER:
531 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
534 print_inquiry(inq_result);
537 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
538 * spec says: The device server is capable of supporting the
539 * specified peripheral device type on this logical unit. However,
540 * the physical device is not currently connected to this logical
543 * The above is vague, as it implies that we could treat 001 and
544 * 011 the same. Stay compatible with previous code, and create a
545 * Scsi_Device for a PQ of 1
547 * Don't set the device offline here; rather let the upper
548 * level drivers eval the PQ to decide whether they should
549 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
552 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
553 sdev->removable = (0x80 & inq_result[1]) >> 7;
554 sdev->lockable = sdev->removable;
555 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
557 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
558 inq_result[56] & 0x04))
560 if (inq_result[7] & 0x60)
562 if (inq_result[7] & 0x10)
565 sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
566 sdev->host->host_no, sdev->channel,
567 sdev->id, sdev->lun);
570 * End driverfs/devfs code.
573 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
574 !(*bflags & BLIST_NOTQ))
575 sdev->tagged_supported = 1;
577 * Some devices (Texel CD ROM drives) have handshaking problems
578 * when used with the Seagate controllers. borken is initialized
579 * to 1, and then set it to 0 here.
581 if ((*bflags & BLIST_BORKEN) == 0)
585 * Apparently some really broken devices (contrary to the SCSI
586 * standards) need to be selected without asserting ATN
588 if (*bflags & BLIST_SELECT_NO_ATN)
589 sdev->select_no_atn = 1;
592 * Some devices may not want to have a start command automatically
593 * issued when a device is added.
595 if (*bflags & BLIST_NOSTARTONADD)
596 sdev->no_start_on_add = 1;
598 if (*bflags & BLIST_SINGLELUN)
599 sdev->single_lun = 1;
602 sdev->use_10_for_rw = 1;
604 if (*bflags & BLIST_MS_SKIP_PAGE_08)
605 sdev->skip_ms_page_8 = 1;
607 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
608 sdev->skip_ms_page_3f = 1;
610 if (*bflags & BLIST_USE_10_BYTE_MS)
611 sdev->use_10_for_ms = 1;
613 /* set the device running here so that slave configure
615 scsi_device_set_state(sdev, SDEV_RUNNING);
617 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
618 sdev->use_192_bytes_for_3f = 1;
620 if (*bflags & BLIST_NOT_LOCKABLE)
623 transport_configure_device(&sdev->sdev_gendev);
625 if (sdev->host->hostt->slave_configure)
626 sdev->host->hostt->slave_configure(sdev);
629 * Ok, the device is now all set up, we can
630 * register it and tell the rest of the kernel
633 scsi_sysfs_add_sdev(sdev);
635 return SCSI_SCAN_LUN_PRESENT;
639 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
640 * @sdevscan: probe the LUN corresponding to this Scsi_Device
641 * @sdevnew: store the value of any new Scsi_Device allocated
642 * @bflagsp: store bflags here if not NULL
645 * Call scsi_probe_lun, if a LUN with an attached device is found,
646 * allocate and set it up by calling scsi_add_lun.
649 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
650 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
651 * attached at the LUN
652 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
654 static int scsi_probe_and_add_lun(struct Scsi_Host *host,
655 uint channel, uint id, uint lun, int *bflagsp,
656 struct scsi_device **sdevp, int rescan, void *hostdata)
658 struct scsi_device *sdev;
659 struct scsi_request *sreq;
660 unsigned char *result;
661 int bflags, res = SCSI_SCAN_NO_RESPONSE;
664 * The rescan flag is used as an optimization, the first scan of a
665 * host adapter calls into here with rescan == 0.
668 sdev = scsi_device_lookup(host, channel, id, lun);
670 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
671 "scsi scan: device exists on <%d:%d:%d:%d>\n",
672 host->host_no, channel, id, lun));
676 *bflagsp = scsi_get_device_flags(sdev,
679 /* XXX: bandaid until callers do refcounting */
680 scsi_device_put(sdev);
681 return SCSI_SCAN_LUN_PRESENT;
685 sdev = scsi_alloc_sdev(host, channel, id, lun, hostdata);
688 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
691 result = kmalloc(256, GFP_ATOMIC |
692 (host->unchecked_isa_dma) ? __GFP_DMA : 0);
696 scsi_probe_lun(sreq, result, &bflags);
698 goto out_free_result;
701 * result contains valid SCSI INQUIRY data.
703 if ((result[0] >> 5) == 3) {
705 * For a Peripheral qualifier 3 (011b), the SCSI
706 * spec says: The device server is not capable of
707 * supporting a physical device on this logical
710 * For disks, this implies that there is no
711 * logical disk configured at sdev->lun, but there
712 * is a target id responding.
714 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
715 "scsi scan: peripheral qualifier of 3,"
716 " no device added\n"));
717 res = SCSI_SCAN_TARGET_PRESENT;
718 goto out_free_result;
721 res = scsi_add_lun(sdev, result, &bflags);
722 if (res == SCSI_SCAN_LUN_PRESENT) {
723 if (bflags & BLIST_KEY) {
725 scsi_unlock_floptical(sreq, result);
734 scsi_release_request(sreq);
736 if (res == SCSI_SCAN_LUN_PRESENT) {
740 if (sdev->host->hostt->slave_destroy)
741 sdev->host->hostt->slave_destroy(sdev);
742 transport_destroy_device(&sdev->sdev_gendev);
743 put_device(&sdev->sdev_gendev);
750 * scsi_sequential_lun_scan - sequentially scan a SCSI target
751 * @sdevscan: scan the host, channel, and id of this Scsi_Device
752 * @bflags: black/white list flag for LUN 0
753 * @lun0_res: result of scanning LUN 0
756 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
757 * scanned) to some maximum lun until a LUN is found with no device
758 * attached. Use the bflags to figure out any oddities.
760 * Modifies sdevscan->lun.
762 static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
763 uint id, int bflags, int lun0_res, int scsi_level, int rescan)
765 unsigned int sparse_lun, lun, max_dev_lun;
767 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
768 " host %d channel %d id %d\n", shost->host_no,
771 max_dev_lun = min(max_scsi_luns, shost->max_lun);
773 * If this device is known to support sparse multiple units,
774 * override the other settings, and scan all of them. Normally,
775 * SCSI-3 devices should be scanned via the REPORT LUNS.
777 if (bflags & BLIST_SPARSELUN) {
778 max_dev_lun = shost->max_lun;
784 * If not sparse lun and no device attached at LUN 0 do not scan
787 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
791 * If less than SCSI_1_CSS, and no special lun scaning, stop
792 * scanning; this matches 2.4 behaviour, but could just be a bug
793 * (to continue scanning a SCSI_1_CSS device).
795 * This test is broken. We might not have any device on lun0 for
796 * a sparselun device, and if that's the case then how would we
797 * know the real scsi_level, eh? It might make sense to just not
798 * scan any SCSI_1 device for non-0 luns, but that check would best
799 * go into scsi_alloc_sdev() and just have it return null when asked
800 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
802 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
803 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
808 * If this device is known to support multiple units, override
809 * the other settings, and scan all of them.
811 if (bflags & BLIST_FORCELUN)
812 max_dev_lun = shost->max_lun;
814 * REGAL CDC-4X: avoid hang after LUN 4
816 if (bflags & BLIST_MAX5LUN)
817 max_dev_lun = min(5U, max_dev_lun);
819 * Do not scan SCSI-2 or lower device past LUN 7, unless
822 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
823 max_dev_lun = min(8U, max_dev_lun);
826 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
827 * until we reach the max, or no LUN is found and we are not
830 for (lun = 1; lun < max_dev_lun; ++lun)
831 if ((scsi_probe_and_add_lun(shost, channel, id, lun,
832 NULL, NULL, rescan, NULL) != SCSI_SCAN_LUN_PRESENT) &&
838 * scsilun_to_int: convert a scsi_lun to an int
839 * @scsilun: struct scsi_lun to be converted.
842 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
843 * integer, and return the result. The caller must check for
844 * truncation before using this function.
847 * The struct scsi_lun is assumed to be four levels, with each level
848 * effectively containing a SCSI byte-ordered (big endian) short; the
849 * addressing bits of each level are ignored (the highest two bits).
850 * For a description of the LUN format, post SCSI-3 see the SCSI
851 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
853 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
854 * the integer: 0x0b030a04
856 static int scsilun_to_int(struct scsi_lun *scsilun)
862 for (i = 0; i < sizeof(lun); i += 2)
863 lun = lun | (((scsilun->scsi_lun[i] << 8) |
864 scsilun->scsi_lun[i + 1]) << (i * 8));
869 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
870 * @sdevscan: scan the host, channel, and id of this Scsi_Device
873 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
874 * command, and scan the resulting list of LUNs by calling
875 * scsi_probe_and_add_lun.
877 * Modifies sdevscan->lun.
880 * 0: scan completed (or no memory, so further scanning is futile)
881 * 1: no report lun scan, or not configured
883 static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
887 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
890 unsigned int num_luns;
891 unsigned int retries;
892 struct scsi_lun *lunp, *lun_data;
893 struct scsi_request *sreq;
895 struct scsi_sense_hdr sshdr;
898 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
899 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
900 * support more than 8 LUNs.
902 if ((bflags & BLIST_NOREPORTLUN) ||
903 sdev->scsi_level < SCSI_2 ||
904 (sdev->scsi_level < SCSI_3 &&
905 (!(bflags & BLIST_REPORTLUN2) || sdev->host->max_lun <= 8)) )
907 if (bflags & BLIST_NOLUN)
910 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
914 sprintf(devname, "host %d channel %d id %d",
915 sdev->host->host_no, sdev->channel, sdev->id);
918 * Allocate enough to hold the header (the same size as one scsi_lun)
919 * plus the max number of luns we are requesting.
921 * Reallocating and trying again (with the exact amount we need)
922 * would be nice, but then we need to somehow limit the size
923 * allocated based on the available memory and the limits of
924 * kmalloc - we don't want a kmalloc() failure of a huge value to
925 * prevent us from finding any LUNs on this target.
927 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
928 lun_data = kmalloc(length, GFP_ATOMIC |
929 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
931 goto out_release_request;
933 scsi_cmd[0] = REPORT_LUNS;
936 * bytes 1 - 5: reserved, set to zero.
938 memset(&scsi_cmd[1], 0, 5);
941 * bytes 6 - 9: length of the command.
943 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
944 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
945 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
946 scsi_cmd[9] = (unsigned char) length & 0xff;
948 scsi_cmd[10] = 0; /* reserved */
949 scsi_cmd[11] = 0; /* control */
950 sreq->sr_cmd_len = 0;
951 sreq->sr_data_direction = DMA_FROM_DEVICE;
954 * We can get a UNIT ATTENTION, for example a power on/reset, so
955 * retry a few times (like sd.c does for TEST UNIT READY).
956 * Experience shows some combinations of adapter/devices get at
957 * least two power on/resets.
959 * Illegal requests (for devices that do not support REPORT LUNS)
960 * should come through as a check condition, and will not generate
963 for (retries = 0; retries < 3; retries++) {
964 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
965 " REPORT LUNS to %s (try %d)\n", devname,
967 scsi_wait_req(sreq, scsi_cmd, lun_data, length,
968 SCSI_TIMEOUT + 4*HZ, 3);
969 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
970 " %s (try %d) result 0x%x\n", sreq->sr_result
971 ? "failed" : "successful", retries,
973 if (sreq->sr_result == 0)
975 else if (scsi_request_normalize_sense(sreq, &sshdr)) {
976 if (sshdr.sense_key != UNIT_ATTENTION)
981 if (sreq->sr_result) {
983 * The device probably does not support a REPORT LUN command
986 scsi_release_request(sreq);
989 scsi_release_request(sreq);
992 * Get the length from the first four bytes of lun_data.
994 data = (u8 *) lun_data->scsi_lun;
995 length = ((data[0] << 24) | (data[1] << 16) |
996 (data[2] << 8) | (data[3] << 0));
998 num_luns = (length / sizeof(struct scsi_lun));
999 if (num_luns > max_scsi_report_luns) {
1000 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1001 " of %d luns reported, try increasing"
1002 " max_scsi_report_luns.\n", devname,
1003 max_scsi_report_luns, num_luns);
1004 num_luns = max_scsi_report_luns;
1007 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUN scan of"
1008 " host %d channel %d id %d\n", sdev->host->host_no,
1009 sdev->channel, sdev->id));
1012 * Scan the luns in lun_data. The entry at offset 0 is really
1013 * the header, so start at 1 and go up to and including num_luns.
1015 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1016 lun = scsilun_to_int(lunp);
1019 * Check if the unused part of lunp is non-zero, and so
1020 * does not fit in lun.
1022 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1026 * Output an error displaying the LUN in byte order,
1027 * this differs from what linux would print for the
1028 * integer LUN value.
1030 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1031 data = (char *)lunp->scsi_lun;
1032 for (i = 0; i < sizeof(struct scsi_lun); i++)
1033 printk("%02x", data[i]);
1034 printk(" has a LUN larger than currently supported.\n");
1035 } else if (lun == 0) {
1037 * LUN 0 has already been scanned.
1039 } else if (lun > sdev->host->max_lun) {
1040 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1041 " than allowed by the host adapter\n",
1046 res = scsi_probe_and_add_lun(sdev->host, sdev->channel,
1047 sdev->id, lun, NULL, NULL, rescan, NULL);
1048 if (res == SCSI_SCAN_NO_RESPONSE) {
1050 * Got some results, but now none, abort.
1052 printk(KERN_ERR "scsi: Unexpected response"
1053 " from %s lun %d while scanning, scan"
1054 " aborted\n", devname, lun);
1063 out_release_request:
1064 scsi_release_request(sreq);
1067 * We are out of memory, don't try scanning any further.
1069 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1073 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1074 uint id, uint lun, void *hostdata)
1076 struct scsi_device *sdev;
1079 down(&shost->scan_mutex);
1080 res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL,
1081 &sdev, 1, hostdata);
1082 if (res != SCSI_SCAN_LUN_PRESENT)
1083 sdev = ERR_PTR(-ENODEV);
1084 up(&shost->scan_mutex);
1088 EXPORT_SYMBOL(__scsi_add_device);
1090 void scsi_rescan_device(struct device *dev)
1092 struct scsi_driver *drv;
1097 drv = to_scsi_driver(dev->driver);
1098 if (try_module_get(drv->owner)) {
1101 module_put(drv->owner);
1104 EXPORT_SYMBOL(scsi_rescan_device);
1107 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1109 * @sdevsca: Scsi_Device handle for scanning
1110 * @shost: host to scan
1111 * @channel: channel to scan
1112 * @id: target id to scan
1115 * Scan the target id on @shost, @channel, and @id. Scan at least LUN
1116 * 0, and possibly all LUNs on the target id.
1118 * Use the pre-allocated @sdevscan as a handle for the scanning. This
1119 * function sets sdevscan->host, sdevscan->id and sdevscan->lun; the
1120 * scanning functions modify sdevscan->lun.
1122 * First try a REPORT LUN scan, if that does not scan the target, do a
1123 * sequential scan of LUNs on the target id.
1125 static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
1126 unsigned int id, unsigned int lun, int rescan)
1130 struct scsi_device *sdev;
1132 if (shost->this_id == id)
1134 * Don't scan the host adapter
1138 if (lun != SCAN_WILD_CARD) {
1140 * Scan for a specific host/chan/id/lun.
1142 scsi_probe_and_add_lun(shost, channel, id, lun, NULL, NULL,
1148 * Scan LUN 0, if there is some response, scan further. Ideally, we
1149 * would not configure LUN 0 until all LUNs are scanned.
1151 res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev,
1153 if (res == SCSI_SCAN_LUN_PRESENT) {
1154 if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
1156 * The REPORT LUN did not scan the target,
1157 * do a sequential scan.
1159 scsi_sequential_lun_scan(shost, channel, id, bflags,
1160 res, sdev->scsi_level, rescan);
1161 } else if (res == SCSI_SCAN_TARGET_PRESENT) {
1163 * There's a target here, but lun 0 is offline so we
1164 * can't use the report_lun scan. Fall back to a
1165 * sequential lun scan with a bflags of SPARSELUN and
1166 * a default scsi level of SCSI_2
1168 scsi_sequential_lun_scan(shost, channel, id, BLIST_SPARSELUN,
1169 SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
1173 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1174 unsigned int id, unsigned int lun, int rescan)
1178 if (id == SCAN_WILD_CARD)
1179 for (id = 0; id < shost->max_id; ++id) {
1181 * XXX adapter drivers when possible (FCP, iSCSI)
1182 * could modify max_id to match the current max,
1183 * not the absolute max.
1185 * XXX add a shost id iterator, so for example,
1186 * the FC ID can be the same as a target id
1187 * without a huge overhead of sparse id's.
1189 if (shost->reverse_ordering)
1191 * Scan from high to low id.
1193 order_id = shost->max_id - id - 1;
1196 scsi_scan_target(shost, channel, order_id, lun, rescan);
1199 scsi_scan_target(shost, channel, id, lun, rescan);
1202 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1203 unsigned int id, unsigned int lun, int rescan)
1205 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
1206 __FUNCTION__, shost->host_no, channel, id, lun));
1208 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1209 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1210 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1213 down(&shost->scan_mutex);
1214 if (channel == SCAN_WILD_CARD)
1215 for (channel = 0; channel <= shost->max_channel; channel++)
1216 scsi_scan_channel(shost, channel, id, lun, rescan);
1218 scsi_scan_channel(shost, channel, id, lun, rescan);
1219 up(&shost->scan_mutex);
1225 * scsi_scan_host - scan the given adapter
1226 * @shost: adapter to scan
1228 void scsi_scan_host(struct Scsi_Host *shost)
1230 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1233 EXPORT_SYMBOL(scsi_scan_host);
1236 * scsi_scan_single_target - scan the given SCSI target
1237 * @shost: adapter to scan
1238 * @chan: channel to scan
1239 * @id: target id to scan
1241 void scsi_scan_single_target(struct Scsi_Host *shost,
1242 unsigned int chan, unsigned int id)
1244 scsi_scan_host_selected(shost, chan, id, SCAN_WILD_CARD, 1);
1246 EXPORT_SYMBOL(scsi_scan_single_target);
1248 void scsi_forget_host(struct Scsi_Host *shost)
1250 struct scsi_device *sdev, *tmp;
1251 unsigned long flags;
1254 * Ok, this look a bit strange. We always look for the first device
1255 * on the list as scsi_remove_device removes them from it - thus we
1256 * also have to release the lock.
1257 * We don't need to get another reference to the device before
1258 * releasing the lock as we already own the reference from
1259 * scsi_register_device that's release in scsi_remove_device. And
1260 * after that we don't look at sdev anymore.
1262 spin_lock_irqsave(shost->host_lock, flags);
1263 list_for_each_entry_safe(sdev, tmp, &shost->__devices, siblings) {
1264 spin_unlock_irqrestore(shost->host_lock, flags);
1265 scsi_remove_device(sdev);
1266 spin_lock_irqsave(shost->host_lock, flags);
1268 spin_unlock_irqrestore(shost->host_lock, flags);
1272 * Function: scsi_get_host_dev()
1274 * Purpose: Create a Scsi_Device that points to the host adapter itself.
1276 * Arguments: SHpnt - Host that needs a Scsi_Device
1278 * Lock status: None assumed.
1280 * Returns: The Scsi_Device or NULL
1283 * Attach a single Scsi_Device to the Scsi_Host - this should
1284 * be made to look like a "pseudo-device" that points to the
1287 * Note - this device is not accessible from any high-level
1288 * drivers (including generics), which is probably not
1289 * optimal. We can add hooks later to attach
1291 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1293 struct scsi_device *sdev;
1295 sdev = scsi_alloc_sdev(shost, 0, shost->this_id, 0, NULL);
1301 EXPORT_SYMBOL(scsi_get_host_dev);
1304 * Function: scsi_free_host_dev()
1306 * Purpose: Free a scsi_device that points to the host adapter itself.
1308 * Arguments: SHpnt - Host that needs a Scsi_Device
1310 * Lock status: None assumed.
1316 void scsi_free_host_dev(struct scsi_device *sdev)
1318 BUG_ON(sdev->id != sdev->host->this_id);
1320 if (sdev->host->hostt->slave_destroy)
1321 sdev->host->hostt->slave_destroy(sdev);
1322 transport_destroy_device(&sdev->sdev_gendev);
1323 put_device(&sdev->sdev_gendev);
1325 EXPORT_SYMBOL(scsi_free_host_dev);