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, *device;
208 sdev = kmalloc(sizeof(*sdev) + shost->transportt->size, GFP_ATOMIC);
212 memset(sdev, 0, sizeof(*sdev));
213 sdev->vendor = scsi_null_device_strs;
214 sdev->model = scsi_null_device_strs;
215 sdev->rev = scsi_null_device_strs;
219 sdev->channel = channel;
220 sdev->sdev_state = SDEV_CREATED;
221 INIT_LIST_HEAD(&sdev->siblings);
222 INIT_LIST_HEAD(&sdev->same_target_siblings);
223 INIT_LIST_HEAD(&sdev->cmd_list);
224 INIT_LIST_HEAD(&sdev->starved_entry);
225 spin_lock_init(&sdev->list_lock);
227 /* usually NULL and set by ->slave_alloc instead */
228 sdev->hostdata = hostdata;
230 /* if the device needs this changing, it may do so in the
231 * slave_configure function */
232 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
235 * Some low level driver could use device->type
240 * Assume that the device will have handshaking problems,
241 * and then fix this field later if it turns out it
246 spin_lock_init(&sdev->sdev_lock);
247 sdev->request_queue = scsi_alloc_queue(sdev);
248 if (!sdev->request_queue)
251 sdev->request_queue->queuedata = sdev;
252 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
254 if (shost->hostt->slave_alloc) {
255 if (shost->hostt->slave_alloc(sdev))
259 if (shost->transportt->setup) {
260 if (shost->transportt->setup(sdev))
261 goto out_cleanup_slave;
264 if (get_device(&sdev->host->shost_gendev)) {
266 device_initialize(&sdev->sdev_gendev);
267 sdev->sdev_gendev.parent = &sdev->host->shost_gendev;
268 sdev->sdev_gendev.bus = &scsi_bus_type;
269 sdev->sdev_gendev.release = scsi_device_dev_release;
270 sprintf(sdev->sdev_gendev.bus_id,"%d:%d:%d:%d",
271 sdev->host->host_no, sdev->channel, sdev->id,
274 class_device_initialize(&sdev->sdev_classdev);
275 sdev->sdev_classdev.dev = &sdev->sdev_gendev;
276 sdev->sdev_classdev.class = &sdev_class;
277 snprintf(sdev->sdev_classdev.class_id, BUS_ID_SIZE,
278 "%d:%d:%d:%d", sdev->host->host_no,
279 sdev->channel, sdev->id, sdev->lun);
281 class_device_initialize(&sdev->transport_classdev);
282 sdev->transport_classdev.dev = &sdev->sdev_gendev;
283 sdev->transport_classdev.class = sdev->host->transportt->class;
284 snprintf(sdev->transport_classdev.class_id, BUS_ID_SIZE,
285 "%d:%d:%d:%d", sdev->host->host_no,
286 sdev->channel, sdev->id, sdev->lun);
288 goto out_cleanup_transport;
291 * If there are any same target siblings, add this to the
294 spin_lock_irqsave(shost->host_lock, flags);
295 list_for_each_entry(device, &shost->__devices, siblings) {
296 if (device->id == sdev->id &&
297 device->channel == sdev->channel) {
298 list_add_tail(&sdev->same_target_siblings,
299 &device->same_target_siblings);
300 sdev->scsi_level = device->scsi_level;
306 * If there wasn't another lun already configured at this
307 * target, then default this device to SCSI_2 until we
310 if (!sdev->scsi_level)
311 sdev->scsi_level = SCSI_2;
313 list_add_tail(&sdev->siblings, &shost->__devices);
314 spin_unlock_irqrestore(shost->host_lock, flags);
317 out_cleanup_transport:
318 if (shost->transportt->cleanup)
319 shost->transportt->cleanup(sdev);
321 if (shost->hostt->slave_destroy)
322 shost->hostt->slave_destroy(sdev);
324 scsi_free_queue(sdev->request_queue);
328 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
333 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
334 * @sreq: used to send the INQUIRY
335 * @inq_result: area to store the INQUIRY result
336 * @bflags: store any bflags found here
339 * Probe the lun associated with @sreq using a standard SCSI INQUIRY;
341 * If the INQUIRY is successful, sreq->sr_result is zero and: the
342 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
343 * are copied to the Scsi_Device at @sreq->sr_device (sdev);
344 * any flags value is stored in *@bflags.
346 static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
349 struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
350 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
351 int possible_inq_resp_len;
356 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY to host %d"
357 " channel %d id %d lun %d\n", sdev->host->host_no,
358 sdev->channel, sdev->id, sdev->lun));
360 memset(scsi_cmd, 0, 6);
361 scsi_cmd[0] = INQUIRY;
362 scsi_cmd[4] = 36; /* issue conservative alloc_length */
363 sreq->sr_cmd_len = 0;
364 sreq->sr_data_direction = DMA_FROM_DEVICE;
366 memset(inq_result, 0, 36);
367 scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result, 36,
368 HZ/2 + HZ*scsi_inq_timeout, 3);
370 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 1st INQUIRY %s with"
371 " code 0x%x\n", sreq->sr_result ?
372 "failed" : "successful", sreq->sr_result));
375 if (sreq->sr_result) {
376 if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) != 0 &&
377 (sreq->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION &&
378 (sreq->sr_sense_buffer[12] == 0x28 ||
379 sreq->sr_sense_buffer[12] == 0x29) &&
380 sreq->sr_sense_buffer[13] == 0) {
381 /* not-ready to ready transition or power-on - good */
382 /* dpg: bogus? INQUIRY never returns UNIT_ATTENTION */
383 /* Supposedly, but many buggy devices do so anyway */
388 * assume no peripheral if any other sort of error
394 * Get any flags for this device.
396 * XXX add a bflags to Scsi_Device, and replace the corresponding
397 * bit fields in Scsi_Device, so bflags need not be passed as an
400 *bflags |= scsi_get_device_flags(sdev, &inq_result[8], &inq_result[16]);
402 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
403 if (BLIST_INQUIRY_36 & *bflags)
404 possible_inq_resp_len = 36;
405 else if (BLIST_INQUIRY_58 & *bflags)
406 possible_inq_resp_len = 58;
407 else if (possible_inq_resp_len > 255)
408 possible_inq_resp_len = 36; /* sanity */
410 if (possible_inq_resp_len > 36) { /* do additional INQUIRY */
411 memset(scsi_cmd, 0, 6);
412 scsi_cmd[0] = INQUIRY;
413 scsi_cmd[4] = (unsigned char) possible_inq_resp_len;
414 sreq->sr_cmd_len = 0;
415 sreq->sr_data_direction = DMA_FROM_DEVICE;
417 * re-zero inq_result just to be safe.
419 memset(inq_result, 0, possible_inq_resp_len);
420 scsi_wait_req(sreq, (void *) scsi_cmd,
422 possible_inq_resp_len, (1+scsi_inq_timeout)*(HZ/2), 3);
423 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 2nd INQUIRY"
424 " %s with code 0x%x\n", sreq->sr_result ?
425 "failed" : "successful", sreq->sr_result));
426 if (sreq->sr_result) {
427 /* if the longer inquiry has failed, flag the device
428 * as only accepting 36 byte inquiries and retry the
430 printk(KERN_INFO "scsi scan: %d byte inquiry failed"
431 " with code %d. Consider BLIST_INQUIRY_36 for"
432 " this device\n", possible_inq_resp_len,
434 *bflags = BLIST_INQUIRY_36;
439 * The INQUIRY can change, this means the length can change.
441 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
442 if (BLIST_INQUIRY_58 & *bflags)
443 possible_inq_resp_len = 58;
444 else if (possible_inq_resp_len > 255)
445 possible_inq_resp_len = 36; /* sanity */
448 sdev->inquiry_len = possible_inq_resp_len;
451 * XXX Abort if the response length is less than 36? If less than
452 * 32, the lookup of the device flags (above) could be invalid,
453 * and it would be possible to take an incorrect action - we do
454 * not want to hang because of a short INQUIRY. On the flip side,
455 * if the device is spun down or becoming ready (and so it gives a
456 * short INQUIRY), an abort here prevents any further use of the
457 * device, including spin up.
459 * Related to the above issue:
461 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
462 * and if not ready, sent a START_STOP to start (maybe spin up) and
463 * then send the INQUIRY again, since the INQUIRY can change after
464 * a device is initialized.
466 * Ideally, start a device if explicitly asked to do so. This
467 * assumes that a device is spun up on power on, spun down on
468 * request, and then spun up on request.
472 * The scanning code needs to know the scsi_level, even if no
473 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
474 * non-zero LUNs can be scanned.
476 sdev->scsi_level = inq_result[2] & 0x07;
477 if (sdev->scsi_level >= 2 ||
478 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
485 * scsi_add_lun - allocate and fully initialze a Scsi_Device
486 * @sdevscan: holds information to be stored in the new Scsi_Device
487 * @sdevnew: store the address of the newly allocated Scsi_Device
488 * @inq_result: holds the result of a previous INQUIRY to the LUN
489 * @bflags: black/white list flag
492 * Allocate and initialize a Scsi_Device matching sdevscan. Optionally
493 * set fields based on values in *@bflags. If @sdevnew is not
494 * NULL, store the address of the new Scsi_Device in *@sdevnew (needed
495 * when scanning a particular LUN).
498 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
499 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
501 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
503 struct scsi_device *sdev_sibling;
504 struct scsi_target *starget;
508 * XXX do not save the inquiry, since it can change underneath us,
509 * save just vendor/model/rev.
511 * Rather than save it and have an ioctl that retrieves the saved
512 * value, have an ioctl that executes the same INQUIRY code used
513 * in scsi_probe_lun, let user level programs doing INQUIRY
514 * scanning run at their own risk, or supply a user level program
515 * that can correctly scan.
517 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
518 if (sdev->inquiry == NULL) {
519 return SCSI_SCAN_NO_RESPONSE;
522 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
523 sdev->vendor = (char *) (sdev->inquiry + 8);
524 sdev->model = (char *) (sdev->inquiry + 16);
525 sdev->rev = (char *) (sdev->inquiry + 32);
527 if (*bflags & BLIST_ISROM) {
529 * It would be better to modify sdev->type, and set
530 * sdev->removable, but then the print_inquiry() output
531 * would not show TYPE_ROM; if print_inquiry() is removed
532 * the issue goes away.
534 inq_result[0] = TYPE_ROM;
535 inq_result[1] |= 0x80; /* removable */
538 switch (sdev->type = (inq_result[0] & 0x1f)) {
545 case TYPE_MEDIUM_CHANGER:
555 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
558 print_inquiry(inq_result);
561 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
562 * spec says: The device server is capable of supporting the
563 * specified peripheral device type on this logical unit. However,
564 * the physical device is not currently connected to this logical
567 * The above is vague, as it implies that we could treat 001 and
568 * 011 the same. Stay compatible with previous code, and create a
569 * Scsi_Device for a PQ of 1
571 * Don't set the device offline here; rather let the upper
572 * level drivers eval the PQ to decide whether they should
573 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
576 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
577 sdev->removable = (0x80 & inq_result[1]) >> 7;
578 sdev->lockable = sdev->removable;
579 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
581 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
582 inq_result[56] & 0x04))
584 if (inq_result[7] & 0x60)
586 if (inq_result[7] & 0x10)
589 sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
590 sdev->host->host_no, sdev->channel,
591 sdev->id, sdev->lun);
594 * End driverfs/devfs code.
597 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
598 !(*bflags & BLIST_NOTQ))
599 sdev->tagged_supported = 1;
601 * Some devices (Texel CD ROM drives) have handshaking problems
602 * when used with the Seagate controllers. borken is initialized
603 * to 1, and then set it to 0 here.
605 if ((*bflags & BLIST_BORKEN) == 0)
609 * Some devices may not want to have a start command automatically
610 * issued when a device is added.
612 if (*bflags & BLIST_NOSTARTONADD)
613 sdev->no_start_on_add = 1;
616 * If we need to allow I/O to only one of the luns attached to
617 * this target id at a time set single_lun, and allocate or modify
620 if (*bflags & BLIST_SINGLELUN) {
621 sdev->single_lun = 1;
622 spin_lock_irqsave(sdev->host->host_lock, flags);
625 * Search for an existing target for this sdev.
627 list_for_each_entry(sdev_sibling, &sdev->same_target_siblings,
628 same_target_siblings) {
629 if (sdev_sibling->sdev_target != NULL) {
630 starget = sdev_sibling->sdev_target;
635 starget = kmalloc(sizeof(*starget), GFP_ATOMIC);
637 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
638 spin_unlock_irqrestore(sdev->host->host_lock,
640 return SCSI_SCAN_NO_RESPONSE;
642 starget->starget_refcnt = 0;
643 starget->starget_sdev_user = NULL;
645 starget->starget_refcnt++;
646 sdev->sdev_target = starget;
647 spin_unlock_irqrestore(sdev->host->host_lock, flags);
650 sdev->use_10_for_rw = 1;
652 if (*bflags & BLIST_MS_SKIP_PAGE_08)
653 sdev->skip_ms_page_8 = 1;
655 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
656 sdev->skip_ms_page_3f = 1;
658 if (*bflags & BLIST_USE_10_BYTE_MS)
659 sdev->use_10_for_ms = 1;
661 /* set the device running here so that slave configure
663 scsi_device_set_state(sdev, SDEV_RUNNING);
665 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
666 sdev->use_192_bytes_for_3f = 1;
668 if (*bflags & BLIST_NOT_LOCKABLE)
671 if(sdev->host->hostt->slave_configure)
672 sdev->host->hostt->slave_configure(sdev);
675 * Ok, the device is now all set up, we can
676 * register it and tell the rest of the kernel
679 scsi_sysfs_add_sdev(sdev);
681 return SCSI_SCAN_LUN_PRESENT;
685 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
686 * @sdevscan: probe the LUN corresponding to this Scsi_Device
687 * @sdevnew: store the value of any new Scsi_Device allocated
688 * @bflagsp: store bflags here if not NULL
691 * Call scsi_probe_lun, if a LUN with an attached device is found,
692 * allocate and set it up by calling scsi_add_lun.
695 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
696 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
697 * attached at the LUN
698 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
700 static int scsi_probe_and_add_lun(struct Scsi_Host *host,
701 uint channel, uint id, uint lun, int *bflagsp,
702 struct scsi_device **sdevp, int rescan, void *hostdata)
704 struct scsi_device *sdev;
705 struct scsi_request *sreq;
706 unsigned char *result;
707 int bflags, res = SCSI_SCAN_NO_RESPONSE;
710 * The rescan flag is used as an optimization, the first scan of a
711 * host adapter calls into here with rescan == 0.
714 sdev = scsi_device_lookup(host, channel, id, lun);
716 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
717 "scsi scan: device exists on <%d:%d:%d:%d>\n",
718 host->host_no, channel, id, lun));
722 *bflagsp = scsi_get_device_flags(sdev,
725 /* XXX: bandaid until callers do refcounting */
726 scsi_device_put(sdev);
727 return SCSI_SCAN_LUN_PRESENT;
731 sdev = scsi_alloc_sdev(host, channel, id, lun, hostdata);
734 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
737 result = kmalloc(256, GFP_ATOMIC |
738 (host->unchecked_isa_dma) ? __GFP_DMA : 0);
742 scsi_probe_lun(sreq, result, &bflags);
744 goto out_free_result;
747 * result contains valid SCSI INQUIRY data.
749 if ((result[0] >> 5) == 3) {
751 * For a Peripheral qualifier 3 (011b), the SCSI
752 * spec says: The device server is not capable of
753 * supporting a physical device on this logical
756 * For disks, this implies that there is no
757 * logical disk configured at sdev->lun, but there
758 * is a target id responding.
760 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
761 "scsi scan: peripheral qualifier of 3,"
762 " no device added\n"));
763 res = SCSI_SCAN_TARGET_PRESENT;
764 goto out_free_result;
767 res = scsi_add_lun(sdev, result, &bflags);
768 if (res == SCSI_SCAN_LUN_PRESENT) {
769 if (bflags & BLIST_KEY) {
771 scsi_unlock_floptical(sreq, result);
780 scsi_release_request(sreq);
782 if (res == SCSI_SCAN_LUN_PRESENT) {
786 if (sdev->host->hostt->slave_destroy)
787 sdev->host->hostt->slave_destroy(sdev);
788 if (sdev->host->transportt->cleanup)
789 sdev->host->transportt->cleanup(sdev);
790 put_device(&sdev->sdev_gendev);
797 * scsi_sequential_lun_scan - sequentially scan a SCSI target
798 * @sdevscan: scan the host, channel, and id of this Scsi_Device
799 * @bflags: black/white list flag for LUN 0
800 * @lun0_res: result of scanning LUN 0
803 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
804 * scanned) to some maximum lun until a LUN is found with no device
805 * attached. Use the bflags to figure out any oddities.
807 * Modifies sdevscan->lun.
809 static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
810 uint id, int bflags, int lun0_res, int scsi_level, int rescan)
812 unsigned int sparse_lun, lun, max_dev_lun;
814 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
815 " host %d channel %d id %d\n", shost->host_no,
818 max_dev_lun = min(max_scsi_luns, shost->max_lun);
820 * If this device is known to support sparse multiple units,
821 * override the other settings, and scan all of them. Normally,
822 * SCSI-3 devices should be scanned via the REPORT LUNS.
824 if (bflags & BLIST_SPARSELUN) {
825 max_dev_lun = shost->max_lun;
831 * If not sparse lun and no device attached at LUN 0 do not scan
834 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
838 * If less than SCSI_1_CSS, and no special lun scaning, stop
839 * scanning; this matches 2.4 behaviour, but could just be a bug
840 * (to continue scanning a SCSI_1_CSS device).
842 * This test is broken. We might not have any device on lun0 for
843 * a sparselun device, and if that's the case then how would we
844 * know the real scsi_level, eh? It might make sense to just not
845 * scan any SCSI_1 device for non-0 luns, but that check would best
846 * go into scsi_alloc_sdev() and just have it return null when asked
847 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
849 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
850 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
855 * If this device is known to support multiple units, override
856 * the other settings, and scan all of them.
858 if (bflags & BLIST_FORCELUN)
859 max_dev_lun = shost->max_lun;
861 * REGAL CDC-4X: avoid hang after LUN 4
863 if (bflags & BLIST_MAX5LUN)
864 max_dev_lun = min(5U, max_dev_lun);
866 * Do not scan SCSI-2 or lower device past LUN 7, unless
869 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
870 max_dev_lun = min(8U, max_dev_lun);
873 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
874 * until we reach the max, or no LUN is found and we are not
877 for (lun = 1; lun < max_dev_lun; ++lun)
878 if ((scsi_probe_and_add_lun(shost, channel, id, lun,
879 NULL, NULL, rescan, NULL) != SCSI_SCAN_LUN_PRESENT) &&
885 * scsilun_to_int: convert a scsi_lun to an int
886 * @scsilun: struct scsi_lun to be converted.
889 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
890 * integer, and return the result. The caller must check for
891 * truncation before using this function.
894 * The struct scsi_lun is assumed to be four levels, with each level
895 * effectively containing a SCSI byte-ordered (big endian) short; the
896 * addressing bits of each level are ignored (the highest two bits).
897 * For a description of the LUN format, post SCSI-3 see the SCSI
898 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
900 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
901 * the integer: 0x0b030a04
903 static int scsilun_to_int(struct scsi_lun *scsilun)
909 for (i = 0; i < sizeof(lun); i += 2)
910 lun = lun | (((scsilun->scsi_lun[i] << 8) |
911 scsilun->scsi_lun[i + 1]) << (i * 8));
916 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
917 * @sdevscan: scan the host, channel, and id of this Scsi_Device
920 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
921 * command, and scan the resulting list of LUNs by calling
922 * scsi_probe_and_add_lun.
924 * Modifies sdevscan->lun.
927 * 0: scan completed (or no memory, so further scanning is futile)
928 * 1: no report lun scan, or not configured
930 static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
934 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
937 unsigned int num_luns;
938 unsigned int retries;
939 struct scsi_lun *lunp, *lun_data;
940 struct scsi_request *sreq;
944 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
945 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
946 * support more than 8 LUNs.
948 if ((bflags & BLIST_NOREPORTLUN) ||
949 sdev->scsi_level < SCSI_2 ||
950 (sdev->scsi_level < SCSI_3 &&
951 (!(bflags & BLIST_REPORTLUN2) || sdev->host->max_lun <= 8)) )
953 if (bflags & BLIST_NOLUN)
956 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
960 sprintf(devname, "host %d channel %d id %d",
961 sdev->host->host_no, sdev->channel, sdev->id);
964 * Allocate enough to hold the header (the same size as one scsi_lun)
965 * plus the max number of luns we are requesting.
967 * Reallocating and trying again (with the exact amount we need)
968 * would be nice, but then we need to somehow limit the size
969 * allocated based on the available memory and the limits of
970 * kmalloc - we don't want a kmalloc() failure of a huge value to
971 * prevent us from finding any LUNs on this target.
973 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
974 lun_data = kmalloc(length, GFP_ATOMIC |
975 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
977 goto out_release_request;
979 scsi_cmd[0] = REPORT_LUNS;
982 * bytes 1 - 5: reserved, set to zero.
984 memset(&scsi_cmd[1], 0, 5);
987 * bytes 6 - 9: length of the command.
989 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
990 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
991 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
992 scsi_cmd[9] = (unsigned char) length & 0xff;
994 scsi_cmd[10] = 0; /* reserved */
995 scsi_cmd[11] = 0; /* control */
996 sreq->sr_cmd_len = 0;
997 sreq->sr_data_direction = DMA_FROM_DEVICE;
1000 * We can get a UNIT ATTENTION, for example a power on/reset, so
1001 * retry a few times (like sd.c does for TEST UNIT READY).
1002 * Experience shows some combinations of adapter/devices get at
1003 * least two power on/resets.
1005 * Illegal requests (for devices that do not support REPORT LUNS)
1006 * should come through as a check condition, and will not generate
1009 for (retries = 0; retries < 3; retries++) {
1010 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1011 " REPORT LUNS to %s (try %d)\n", devname,
1013 scsi_wait_req(sreq, scsi_cmd, lun_data, length,
1014 SCSI_TIMEOUT + 4*HZ, 3);
1015 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1016 " %s (try %d) result 0x%x\n", sreq->sr_result
1017 ? "failed" : "successful", retries,
1019 if (sreq->sr_result == 0 ||
1020 sreq->sr_sense_buffer[2] != UNIT_ATTENTION)
1024 if (sreq->sr_result) {
1026 * The device probably does not support a REPORT LUN command
1029 scsi_release_request(sreq);
1032 scsi_release_request(sreq);
1035 * Get the length from the first four bytes of lun_data.
1037 data = (u8 *) lun_data->scsi_lun;
1038 length = ((data[0] << 24) | (data[1] << 16) |
1039 (data[2] << 8) | (data[3] << 0));
1041 num_luns = (length / sizeof(struct scsi_lun));
1042 if (num_luns > max_scsi_report_luns) {
1043 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1044 " of %d luns reported, try increasing"
1045 " max_scsi_report_luns.\n", devname,
1046 max_scsi_report_luns, num_luns);
1047 num_luns = max_scsi_report_luns;
1050 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUN scan of"
1051 " host %d channel %d id %d\n", sdev->host->host_no,
1052 sdev->channel, sdev->id));
1055 * Scan the luns in lun_data. The entry at offset 0 is really
1056 * the header, so start at 1 and go up to and including num_luns.
1058 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1059 lun = scsilun_to_int(lunp);
1062 * Check if the unused part of lunp is non-zero, and so
1063 * does not fit in lun.
1065 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1069 * Output an error displaying the LUN in byte order,
1070 * this differs from what linux would print for the
1071 * integer LUN value.
1073 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1074 data = (char *)lunp->scsi_lun;
1075 for (i = 0; i < sizeof(struct scsi_lun); i++)
1076 printk("%02x", data[i]);
1077 printk(" has a LUN larger than currently supported.\n");
1078 } else if (lun == 0) {
1080 * LUN 0 has already been scanned.
1082 } else if (lun > sdev->host->max_lun) {
1083 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1084 " than allowed by the host adapter\n",
1089 res = scsi_probe_and_add_lun(sdev->host, sdev->channel,
1090 sdev->id, lun, NULL, NULL, rescan, NULL);
1091 if (res == SCSI_SCAN_NO_RESPONSE) {
1093 * Got some results, but now none, abort.
1095 printk(KERN_ERR "scsi: Unexpected response"
1096 " from %s lun %d while scanning, scan"
1097 " aborted\n", devname, lun);
1106 out_release_request:
1107 scsi_release_request(sreq);
1110 * We are out of memory, don't try scanning any further.
1112 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1116 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1117 uint id, uint lun, void *hostdata)
1119 struct scsi_device *sdev;
1122 down(&shost->scan_mutex);
1123 res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL,
1124 &sdev, 1, hostdata);
1125 if (res != SCSI_SCAN_LUN_PRESENT)
1126 sdev = ERR_PTR(-ENODEV);
1127 up(&shost->scan_mutex);
1132 void scsi_rescan_device(struct device *dev)
1134 struct scsi_driver *drv;
1139 drv = to_scsi_driver(dev->driver);
1140 if (try_module_get(drv->owner)) {
1143 module_put(drv->owner);
1148 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1150 * @sdevsca: Scsi_Device handle for scanning
1151 * @shost: host to scan
1152 * @channel: channel to scan
1153 * @id: target id to scan
1156 * Scan the target id on @shost, @channel, and @id. Scan at least LUN
1157 * 0, and possibly all LUNs on the target id.
1159 * Use the pre-allocated @sdevscan as a handle for the scanning. This
1160 * function sets sdevscan->host, sdevscan->id and sdevscan->lun; the
1161 * scanning functions modify sdevscan->lun.
1163 * First try a REPORT LUN scan, if that does not scan the target, do a
1164 * sequential scan of LUNs on the target id.
1166 static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
1167 unsigned int id, unsigned int lun, int rescan)
1171 struct scsi_device *sdev;
1173 if (shost->this_id == id)
1175 * Don't scan the host adapter
1179 if (lun != SCAN_WILD_CARD) {
1181 * Scan for a specific host/chan/id/lun.
1183 scsi_probe_and_add_lun(shost, channel, id, lun, NULL, NULL,
1189 * Scan LUN 0, if there is some response, scan further. Ideally, we
1190 * would not configure LUN 0 until all LUNs are scanned.
1192 res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev,
1194 if (res == SCSI_SCAN_LUN_PRESENT) {
1195 if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
1197 * The REPORT LUN did not scan the target,
1198 * do a sequential scan.
1200 scsi_sequential_lun_scan(shost, channel, id, bflags,
1201 res, sdev->scsi_level, rescan);
1202 } else if (res == SCSI_SCAN_TARGET_PRESENT) {
1204 * There's a target here, but lun 0 is offline so we
1205 * can't use the report_lun scan. Fall back to a
1206 * sequential lun scan with a bflags of SPARSELUN and
1207 * a default scsi level of SCSI_2
1209 scsi_sequential_lun_scan(shost, channel, id, BLIST_SPARSELUN,
1210 SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
1214 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1215 unsigned int id, unsigned int lun, int rescan)
1219 if (id == SCAN_WILD_CARD)
1220 for (id = 0; id < shost->max_id; ++id) {
1222 * XXX adapter drivers when possible (FCP, iSCSI)
1223 * could modify max_id to match the current max,
1224 * not the absolute max.
1226 * XXX add a shost id iterator, so for example,
1227 * the FC ID can be the same as a target id
1228 * without a huge overhead of sparse id's.
1230 if (shost->reverse_ordering)
1232 * Scan from high to low id.
1234 order_id = shost->max_id - id - 1;
1237 scsi_scan_target(shost, channel, order_id, lun, rescan);
1240 scsi_scan_target(shost, channel, id, lun, rescan);
1243 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1244 unsigned int id, unsigned int lun, int rescan)
1246 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
1247 __FUNCTION__, shost->host_no, channel, id, lun));
1249 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1250 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1251 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1254 down(&shost->scan_mutex);
1255 if (channel == SCAN_WILD_CARD)
1256 for (channel = 0; channel <= shost->max_channel; channel++)
1257 scsi_scan_channel(shost, channel, id, lun, rescan);
1259 scsi_scan_channel(shost, channel, id, lun, rescan);
1260 up(&shost->scan_mutex);
1266 * scsi_scan_host - scan the given adapter
1267 * @shost: adapter to scan
1269 void scsi_scan_host(struct Scsi_Host *shost)
1271 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1275 void scsi_forget_host(struct Scsi_Host *shost)
1277 struct scsi_device *sdev, *tmp;
1278 unsigned long flags;
1281 * Ok, this look a bit strange. We always look for the first device
1282 * on the list as scsi_remove_device removes them from it - thus we
1283 * also have to release the lock.
1284 * We don't need to get another reference to the device before
1285 * releasing the lock as we already own the reference from
1286 * scsi_register_device that's release in scsi_remove_device. And
1287 * after that we don't look at sdev anymore.
1289 spin_lock_irqsave(shost->host_lock, flags);
1290 list_for_each_entry_safe(sdev, tmp, &shost->__devices, siblings) {
1291 spin_unlock_irqrestore(shost->host_lock, flags);
1292 scsi_remove_device(sdev);
1293 spin_lock_irqsave(shost->host_lock, flags);
1295 spin_unlock_irqrestore(shost->host_lock, flags);
1299 * Function: scsi_get_host_dev()
1301 * Purpose: Create a Scsi_Device that points to the host adapter itself.
1303 * Arguments: SHpnt - Host that needs a Scsi_Device
1305 * Lock status: None assumed.
1307 * Returns: The Scsi_Device or NULL
1310 * Attach a single Scsi_Device to the Scsi_Host - this should
1311 * be made to look like a "pseudo-device" that points to the
1314 * Note - this device is not accessible from any high-level
1315 * drivers (including generics), which is probably not
1316 * optimal. We can add hooks later to attach
1318 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1320 struct scsi_device *sdev;
1322 sdev = scsi_alloc_sdev(shost, 0, shost->this_id, 0, NULL);
1330 * Function: scsi_free_host_dev()
1332 * Purpose: Free a scsi_device that points to the host adapter itself.
1334 * Arguments: SHpnt - Host that needs a Scsi_Device
1336 * Lock status: None assumed.
1342 void scsi_free_host_dev(struct scsi_device *sdev)
1344 BUG_ON(sdev->id != sdev->host->this_id);
1346 if (sdev->host->hostt->slave_destroy)
1347 sdev->host->hostt->slave_destroy(sdev);
1348 if (sdev->host->transportt->cleanup)
1349 sdev->host->transportt->cleanup(sdev);
1350 put_device(&sdev->sdev_gendev);