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_driver.h>
36 #include <scsi/scsi_devinfo.h>
37 #include <scsi/scsi_host.h>
38 #include <scsi/scsi_transport.h>
41 #include "scsi_priv.h"
42 #include "scsi_logging.h"
44 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
45 " SCSI scanning, some SCSI devices might not be configured\n"
50 #define SCSI_TIMEOUT (2*HZ)
53 * Prefix values for the SCSI id's (stored in driverfs name field)
55 #define SCSI_UID_SER_NUM 'S'
56 #define SCSI_UID_UNKNOWN 'Z'
59 * Return values of some of the scanning functions.
61 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
62 * includes allocation or general failures preventing IO from being sent.
64 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
67 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
70 #define SCSI_SCAN_NO_RESPONSE 0
71 #define SCSI_SCAN_TARGET_PRESENT 1
72 #define SCSI_SCAN_LUN_PRESENT 2
74 static char *scsi_null_device_strs = "nullnullnullnull";
76 #define MAX_SCSI_LUNS 512
78 #ifdef CONFIG_SCSI_MULTI_LUN
79 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
81 static unsigned int max_scsi_luns = 1;
84 module_param_named(max_luns, max_scsi_luns, int, S_IRUGO|S_IWUSR);
85 MODULE_PARM_DESC(max_luns,
86 "last scsi LUN (should be between 1 and 2^32-1)");
89 * max_scsi_report_luns: the maximum number of LUNS that will be
90 * returned from the REPORT LUNS command. 8 times this value must
91 * be allocated. In theory this could be up to an 8 byte value, but
92 * in practice, the maximum number of LUNs suppored by any device
95 static unsigned int max_scsi_report_luns = 511;
97 module_param_named(max_report_luns, max_scsi_report_luns, int, S_IRUGO|S_IWUSR);
98 MODULE_PARM_DESC(max_report_luns,
99 "REPORT LUNS maximum number of LUNS received (should be"
100 " between 1 and 16384)");
102 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
104 module_param_named(inq_timeout, scsi_inq_timeout, int, S_IRUGO|S_IWUSR);
105 MODULE_PARM_DESC(inq_timeout,
106 "Timeout (in seconds) waiting for devices to answer INQUIRY."
107 " Default is 5. Some non-compliant devices need more.");
110 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
111 * @sreq: used to send the command
112 * @result: area to store the result of the MODE SENSE
115 * Send a vendor specific MODE SENSE (not a MODE SELECT) command using
116 * @sreq to unlock a device, storing the (unused) results into result.
117 * Called for BLIST_KEY devices.
119 static void scsi_unlock_floptical(struct scsi_request *sreq,
120 unsigned char *result)
122 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
124 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
125 scsi_cmd[0] = MODE_SENSE;
129 scsi_cmd[4] = 0x2a; /* size */
131 sreq->sr_cmd_len = 0;
132 sreq->sr_data_direction = DMA_FROM_DEVICE;
133 scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
137 * print_inquiry - printk the inquiry information
138 * @inq_result: printk this SCSI INQUIRY
141 * printk the vendor, model, and other information found in the
142 * INQUIRY data in @inq_result.
145 * Remove this, and replace with a hotplug event that logs any
146 * relevant information.
148 static void print_inquiry(unsigned char *inq_result)
152 printk(KERN_NOTICE " Vendor: ");
153 for (i = 8; i < 16; i++)
154 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
155 printk("%c", inq_result[i]);
160 for (i = 16; i < 32; i++)
161 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
162 printk("%c", inq_result[i]);
167 for (i = 32; i < 36; i++)
168 if (inq_result[i] >= 0x20 && i < inq_result[4] + 5)
169 printk("%c", inq_result[i]);
175 i = inq_result[0] & 0x1f;
177 printk(KERN_NOTICE " Type: %s ",
179 MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] :
181 printk(" ANSI SCSI revision: %02x",
182 inq_result[2] & 0x07);
183 if ((inq_result[2] & 0x07) == 1 && (inq_result[3] & 0x0f) == 1)
190 * scsi_alloc_sdev - allocate and setup a scsi_Device
193 * Allocate, initialize for io, and return a pointer to a scsi_Device.
194 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
195 * adds scsi_Device to the appropriate list.
198 * scsi_Device pointer, or NULL on failure.
200 static struct scsi_device *scsi_alloc_sdev(struct Scsi_Host *shost,
201 uint channel, uint id, uint lun)
203 struct scsi_device *sdev, *device;
206 sdev = kmalloc(sizeof(*sdev) + shost->transportt->size, GFP_ATOMIC);
210 memset(sdev, 0, sizeof(*sdev));
211 sdev->vendor = scsi_null_device_strs;
212 sdev->model = scsi_null_device_strs;
213 sdev->rev = scsi_null_device_strs;
217 sdev->channel = channel;
218 sdev->sdev_state = SDEV_CREATED;
219 INIT_LIST_HEAD(&sdev->siblings);
220 INIT_LIST_HEAD(&sdev->same_target_siblings);
221 INIT_LIST_HEAD(&sdev->cmd_list);
222 INIT_LIST_HEAD(&sdev->starved_entry);
223 spin_lock_init(&sdev->list_lock);
226 /* if the device needs this changing, it may do so in the
227 * slave_configure function */
228 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
231 * Some low level driver could use device->type
236 * Assume that the device will have handshaking problems,
237 * and then fix this field later if it turns out it
242 spin_lock_init(&sdev->sdev_lock);
243 sdev->request_queue = scsi_alloc_queue(sdev);
244 if (!sdev->request_queue)
247 sdev->request_queue->queuedata = sdev;
248 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
250 if (shost->hostt->slave_alloc) {
251 if (shost->hostt->slave_alloc(sdev))
255 if (shost->transportt->setup) {
256 if (shost->transportt->setup(sdev))
257 goto out_cleanup_slave;
260 if (get_device(&sdev->host->shost_gendev)) {
262 device_initialize(&sdev->sdev_gendev);
263 sdev->sdev_gendev.parent = &sdev->host->shost_gendev;
264 sdev->sdev_gendev.bus = &scsi_bus_type;
265 sdev->sdev_gendev.release = scsi_device_dev_release;
266 sprintf(sdev->sdev_gendev.bus_id,"%d:%d:%d:%d",
267 sdev->host->host_no, sdev->channel, sdev->id,
270 class_device_initialize(&sdev->sdev_classdev);
271 sdev->sdev_classdev.dev = &sdev->sdev_gendev;
272 sdev->sdev_classdev.class = &sdev_class;
273 snprintf(sdev->sdev_classdev.class_id, BUS_ID_SIZE,
274 "%d:%d:%d:%d", sdev->host->host_no,
275 sdev->channel, sdev->id, sdev->lun);
277 class_device_initialize(&sdev->transport_classdev);
278 sdev->transport_classdev.dev = &sdev->sdev_gendev;
279 sdev->transport_classdev.class = sdev->host->transportt->class;
280 snprintf(sdev->transport_classdev.class_id, BUS_ID_SIZE,
281 "%d:%d:%d:%d", sdev->host->host_no,
282 sdev->channel, sdev->id, sdev->lun);
284 goto out_cleanup_transport;
287 * If there are any same target siblings, add this to the
290 spin_lock_irqsave(shost->host_lock, flags);
291 list_for_each_entry(device, &shost->__devices, siblings) {
292 if (device->id == sdev->id &&
293 device->channel == sdev->channel) {
294 list_add_tail(&sdev->same_target_siblings,
295 &device->same_target_siblings);
296 sdev->scsi_level = device->scsi_level;
302 * If there wasn't another lun already configured at this
303 * target, then default this device to SCSI_2 until we
306 if (!sdev->scsi_level)
307 sdev->scsi_level = SCSI_2;
309 list_add_tail(&sdev->siblings, &shost->__devices);
310 spin_unlock_irqrestore(shost->host_lock, flags);
313 out_cleanup_transport:
314 if (shost->transportt->cleanup)
315 shost->transportt->cleanup(sdev);
317 if (shost->hostt->slave_destroy)
318 shost->hostt->slave_destroy(sdev);
320 scsi_free_queue(sdev->request_queue);
324 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
329 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
330 * @sreq: used to send the INQUIRY
331 * @inq_result: area to store the INQUIRY result
332 * @bflags: store any bflags found here
335 * Probe the lun associated with @sreq using a standard SCSI INQUIRY;
337 * If the INQUIRY is successful, sreq->sr_result is zero and: the
338 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
339 * are copied to the Scsi_Device at @sreq->sr_device (sdev);
340 * any flags value is stored in *@bflags.
342 static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
345 struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
346 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
347 int possible_inq_resp_len;
352 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY to host %d"
353 " channel %d id %d lun %d\n", sdev->host->host_no,
354 sdev->channel, sdev->id, sdev->lun));
356 memset(scsi_cmd, 0, 6);
357 scsi_cmd[0] = INQUIRY;
358 scsi_cmd[4] = 36; /* issue conservative alloc_length */
359 sreq->sr_cmd_len = 0;
360 sreq->sr_data_direction = DMA_FROM_DEVICE;
362 memset(inq_result, 0, 36);
363 scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result, 36,
364 HZ/2 + HZ*scsi_inq_timeout, 3);
366 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 1st INQUIRY %s with"
367 " code 0x%x\n", sreq->sr_result ?
368 "failed" : "successful", sreq->sr_result));
371 if (sreq->sr_result) {
372 if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) != 0 &&
373 (sreq->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION &&
374 (sreq->sr_sense_buffer[12] == 0x28 ||
375 sreq->sr_sense_buffer[12] == 0x29) &&
376 sreq->sr_sense_buffer[13] == 0) {
377 /* not-ready to ready transition or power-on - good */
378 /* dpg: bogus? INQUIRY never returns UNIT_ATTENTION */
379 /* Supposedly, but many buggy devices do so anyway */
384 * assume no peripheral if any other sort of error
390 * Get any flags for this device.
392 * XXX add a bflags to Scsi_Device, and replace the corresponding
393 * bit fields in Scsi_Device, so bflags need not be passed as an
396 *bflags |= scsi_get_device_flags(sdev, &inq_result[8], &inq_result[16]);
398 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
399 if (BLIST_INQUIRY_36 & *bflags)
400 possible_inq_resp_len = 36;
401 else if (BLIST_INQUIRY_58 & *bflags)
402 possible_inq_resp_len = 58;
403 else if (possible_inq_resp_len > 255)
404 possible_inq_resp_len = 36; /* sanity */
406 if (possible_inq_resp_len > 36) { /* do additional INQUIRY */
407 memset(scsi_cmd, 0, 6);
408 scsi_cmd[0] = INQUIRY;
409 scsi_cmd[4] = (unsigned char) possible_inq_resp_len;
410 sreq->sr_cmd_len = 0;
411 sreq->sr_data_direction = DMA_FROM_DEVICE;
413 * re-zero inq_result just to be safe.
415 memset(inq_result, 0, possible_inq_resp_len);
416 scsi_wait_req(sreq, (void *) scsi_cmd,
418 possible_inq_resp_len, (1+scsi_inq_timeout)*(HZ/2), 3);
419 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: 2nd INQUIRY"
420 " %s with code 0x%x\n", sreq->sr_result ?
421 "failed" : "successful", sreq->sr_result));
422 if (sreq->sr_result) {
423 /* if the longer inquiry has failed, flag the device
424 * as only accepting 36 byte inquiries and retry the
426 printk(KERN_INFO "scsi scan: %d byte inquiry failed"
427 " with code %d. Consider BLIST_INQUIRY_36 for"
428 " this device\n", possible_inq_resp_len,
430 *bflags = BLIST_INQUIRY_36;
435 * The INQUIRY can change, this means the length can change.
437 possible_inq_resp_len = (unsigned char) inq_result[4] + 5;
438 if (BLIST_INQUIRY_58 & *bflags)
439 possible_inq_resp_len = 58;
440 else if (possible_inq_resp_len > 255)
441 possible_inq_resp_len = 36; /* sanity */
444 sdev->inquiry_len = possible_inq_resp_len;
447 * XXX Abort if the response length is less than 36? If less than
448 * 32, the lookup of the device flags (above) could be invalid,
449 * and it would be possible to take an incorrect action - we do
450 * not want to hang because of a short INQUIRY. On the flip side,
451 * if the device is spun down or becoming ready (and so it gives a
452 * short INQUIRY), an abort here prevents any further use of the
453 * device, including spin up.
455 * Related to the above issue:
457 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
458 * and if not ready, sent a START_STOP to start (maybe spin up) and
459 * then send the INQUIRY again, since the INQUIRY can change after
460 * a device is initialized.
462 * Ideally, start a device if explicitly asked to do so. This
463 * assumes that a device is spun up on power on, spun down on
464 * request, and then spun up on request.
468 * The scanning code needs to know the scsi_level, even if no
469 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
470 * non-zero LUNs can be scanned.
472 sdev->scsi_level = inq_result[2] & 0x07;
473 if (sdev->scsi_level >= 2 ||
474 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
481 * scsi_add_lun - allocate and fully initialze a Scsi_Device
482 * @sdevscan: holds information to be stored in the new Scsi_Device
483 * @sdevnew: store the address of the newly allocated Scsi_Device
484 * @inq_result: holds the result of a previous INQUIRY to the LUN
485 * @bflags: black/white list flag
488 * Allocate and initialize a Scsi_Device matching sdevscan. Optionally
489 * set fields based on values in *@bflags. If @sdevnew is not
490 * NULL, store the address of the new Scsi_Device in *@sdevnew (needed
491 * when scanning a particular LUN).
494 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
495 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
497 static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
499 struct scsi_device *sdev_sibling;
500 struct scsi_target *starget;
504 * XXX do not save the inquiry, since it can change underneath us,
505 * save just vendor/model/rev.
507 * Rather than save it and have an ioctl that retrieves the saved
508 * value, have an ioctl that executes the same INQUIRY code used
509 * in scsi_probe_lun, let user level programs doing INQUIRY
510 * scanning run at their own risk, or supply a user level program
511 * that can correctly scan.
513 sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
514 if (sdev->inquiry == NULL) {
515 return SCSI_SCAN_NO_RESPONSE;
518 memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
519 sdev->vendor = (char *) (sdev->inquiry + 8);
520 sdev->model = (char *) (sdev->inquiry + 16);
521 sdev->rev = (char *) (sdev->inquiry + 32);
523 if (*bflags & BLIST_ISROM) {
525 * It would be better to modify sdev->type, and set
526 * sdev->removable, but then the print_inquiry() output
527 * would not show TYPE_ROM; if print_inquiry() is removed
528 * the issue goes away.
530 inq_result[0] = TYPE_ROM;
531 inq_result[1] |= 0x80; /* removable */
534 switch (sdev->type = (inq_result[0] & 0x1f)) {
541 case TYPE_MEDIUM_CHANGER:
551 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
554 print_inquiry(inq_result);
557 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
558 * spec says: The device server is capable of supporting the
559 * specified peripheral device type on this logical unit. However,
560 * the physical device is not currently connected to this logical
563 * The above is vague, as it implies that we could treat 001 and
564 * 011 the same. Stay compatible with previous code, and create a
565 * Scsi_Device for a PQ of 1
567 * Don't set the device offline here; rather let the upper
568 * level drivers eval the PQ to decide whether they should
569 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
572 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
573 sdev->removable = (0x80 & inq_result[1]) >> 7;
574 sdev->lockable = sdev->removable;
575 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
577 if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
578 inq_result[56] & 0x04))
580 if (inq_result[7] & 0x60)
582 if (inq_result[7] & 0x10)
585 sprintf(sdev->devfs_name, "scsi/host%d/bus%d/target%d/lun%d",
586 sdev->host->host_no, sdev->channel,
587 sdev->id, sdev->lun);
590 * End driverfs/devfs code.
593 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
594 !(*bflags & BLIST_NOTQ))
595 sdev->tagged_supported = 1;
597 * Some devices (Texel CD ROM drives) have handshaking problems
598 * when used with the Seagate controllers. borken is initialized
599 * to 1, and then set it to 0 here.
601 if ((*bflags & BLIST_BORKEN) == 0)
605 * Some devices may not want to have a start command automatically
606 * issued when a device is added.
608 if (*bflags & BLIST_NOSTARTONADD)
609 sdev->no_start_on_add = 1;
612 * If we need to allow I/O to only one of the luns attached to
613 * this target id at a time set single_lun, and allocate or modify
616 if (*bflags & BLIST_SINGLELUN) {
617 sdev->single_lun = 1;
618 spin_lock_irqsave(sdev->host->host_lock, flags);
621 * Search for an existing target for this sdev.
623 list_for_each_entry(sdev_sibling, &sdev->same_target_siblings,
624 same_target_siblings) {
625 if (sdev_sibling->sdev_target != NULL) {
626 starget = sdev_sibling->sdev_target;
631 starget = kmalloc(sizeof(*starget), GFP_ATOMIC);
633 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
634 spin_unlock_irqrestore(sdev->host->host_lock,
636 return SCSI_SCAN_NO_RESPONSE;
638 starget->starget_refcnt = 0;
639 starget->starget_sdev_user = NULL;
641 starget->starget_refcnt++;
642 sdev->sdev_target = starget;
643 spin_unlock_irqrestore(sdev->host->host_lock, flags);
646 sdev->use_10_for_rw = 1;
648 if (*bflags & BLIST_MS_SKIP_PAGE_08)
649 sdev->skip_ms_page_8 = 1;
651 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
652 sdev->skip_ms_page_3f = 1;
654 if (*bflags & BLIST_USE_10_BYTE_MS)
655 sdev->use_10_for_ms = 1;
657 /* set the device running here so that slave configure
659 scsi_device_set_state(sdev, SDEV_RUNNING);
661 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
662 sdev->use_192_bytes_for_3f = 1;
664 if(sdev->host->hostt->slave_configure)
665 sdev->host->hostt->slave_configure(sdev);
668 * Ok, the device is now all set up, we can
669 * register it and tell the rest of the kernel
672 scsi_sysfs_add_sdev(sdev);
674 return SCSI_SCAN_LUN_PRESENT;
678 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
679 * @sdevscan: probe the LUN corresponding to this Scsi_Device
680 * @sdevnew: store the value of any new Scsi_Device allocated
681 * @bflagsp: store bflags here if not NULL
684 * Call scsi_probe_lun, if a LUN with an attached device is found,
685 * allocate and set it up by calling scsi_add_lun.
688 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a Scsi_Device
689 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
690 * attached at the LUN
691 * SCSI_SCAN_LUN_PRESENT: a new Scsi_Device was allocated and initialized
693 static int scsi_probe_and_add_lun(struct Scsi_Host *host,
694 uint channel, uint id, uint lun, int *bflagsp,
695 struct scsi_device **sdevp, int rescan)
697 struct scsi_device *sdev;
698 struct scsi_request *sreq;
699 unsigned char *result;
700 int bflags, res = SCSI_SCAN_NO_RESPONSE;
703 * The rescan flag is used as an optimization, the first scan of a
704 * host adapter calls into here with rescan == 0.
707 sdev = scsi_device_lookup(host, channel, id, lun);
709 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
710 "scsi scan: device exists on <%d:%d:%d:%d>\n",
711 host->host_no, channel, id, lun));
715 *bflagsp = scsi_get_device_flags(sdev,
718 /* XXX: bandaid until callers do refcounting */
719 scsi_device_put(sdev);
720 return SCSI_SCAN_LUN_PRESENT;
724 sdev = scsi_alloc_sdev(host, channel, id, lun);
727 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
730 result = kmalloc(256, GFP_ATOMIC |
731 (host->unchecked_isa_dma) ? __GFP_DMA : 0);
735 scsi_probe_lun(sreq, result, &bflags);
737 goto out_free_result;
740 * result contains valid SCSI INQUIRY data.
742 if ((result[0] >> 5) == 3) {
744 * For a Peripheral qualifier 3 (011b), the SCSI
745 * spec says: The device server is not capable of
746 * supporting a physical device on this logical
749 * For disks, this implies that there is no
750 * logical disk configured at sdev->lun, but there
751 * is a target id responding.
753 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
754 "scsi scan: peripheral qualifier of 3,"
755 " no device added\n"));
756 res = SCSI_SCAN_TARGET_PRESENT;
757 goto out_free_result;
760 res = scsi_add_lun(sdev, result, &bflags);
761 if (res == SCSI_SCAN_LUN_PRESENT) {
762 if (bflags & BLIST_KEY) {
764 scsi_unlock_floptical(sreq, result);
773 scsi_release_request(sreq);
775 if (res == SCSI_SCAN_LUN_PRESENT) {
779 if (sdev->host->hostt->slave_destroy)
780 sdev->host->hostt->slave_destroy(sdev);
781 if (sdev->host->transportt->cleanup)
782 sdev->host->transportt->cleanup(sdev);
783 put_device(&sdev->sdev_gendev);
790 * scsi_sequential_lun_scan - sequentially scan a SCSI target
791 * @sdevscan: scan the host, channel, and id of this Scsi_Device
792 * @bflags: black/white list flag for LUN 0
793 * @lun0_res: result of scanning LUN 0
796 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
797 * scanned) to some maximum lun until a LUN is found with no device
798 * attached. Use the bflags to figure out any oddities.
800 * Modifies sdevscan->lun.
802 static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
803 uint id, int bflags, int lun0_res, int scsi_level, int rescan)
805 unsigned int sparse_lun, lun, max_dev_lun;
807 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
808 " host %d channel %d id %d\n", shost->host_no,
811 max_dev_lun = min(max_scsi_luns, shost->max_lun);
813 * If this device is known to support sparse multiple units,
814 * override the other settings, and scan all of them. Normally,
815 * SCSI-3 devices should be scanned via the REPORT LUNS.
817 if (bflags & BLIST_SPARSELUN) {
818 max_dev_lun = shost->max_lun;
824 * If not sparse lun and no device attached at LUN 0 do not scan
827 if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
831 * If less than SCSI_1_CSS, and no special lun scaning, stop
832 * scanning; this matches 2.4 behaviour, but could just be a bug
833 * (to continue scanning a SCSI_1_CSS device).
835 * This test is broken. We might not have any device on lun0 for
836 * a sparselun device, and if that's the case then how would we
837 * know the real scsi_level, eh? It might make sense to just not
838 * scan any SCSI_1 device for non-0 luns, but that check would best
839 * go into scsi_alloc_sdev() and just have it return null when asked
840 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
842 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
843 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
848 * If this device is known to support multiple units, override
849 * the other settings, and scan all of them.
851 if (bflags & BLIST_FORCELUN)
852 max_dev_lun = shost->max_lun;
854 * REGAL CDC-4X: avoid hang after LUN 4
856 if (bflags & BLIST_MAX5LUN)
857 max_dev_lun = min(5U, max_dev_lun);
859 * Do not scan SCSI-2 or lower device past LUN 7, unless
862 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
863 max_dev_lun = min(8U, max_dev_lun);
866 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
867 * until we reach the max, or no LUN is found and we are not
870 for (lun = 1; lun < max_dev_lun; ++lun)
871 if ((scsi_probe_and_add_lun(shost, channel, id, lun,
872 NULL, NULL, rescan) != SCSI_SCAN_LUN_PRESENT) &&
878 * scsilun_to_int: convert a scsi_lun to an int
879 * @scsilun: struct scsi_lun to be converted.
882 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
883 * integer, and return the result. The caller must check for
884 * truncation before using this function.
887 * The struct scsi_lun is assumed to be four levels, with each level
888 * effectively containing a SCSI byte-ordered (big endian) short; the
889 * addressing bits of each level are ignored (the highest two bits).
890 * For a description of the LUN format, post SCSI-3 see the SCSI
891 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
893 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
894 * the integer: 0x0b030a04
896 static int scsilun_to_int(struct scsi_lun *scsilun)
902 for (i = 0; i < sizeof(lun); i += 2)
903 lun = lun | (((scsilun->scsi_lun[i] << 8) |
904 scsilun->scsi_lun[i + 1]) << (i * 8));
909 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
910 * @sdevscan: scan the host, channel, and id of this Scsi_Device
913 * If @sdevscan is for a SCSI-3 or up device, send a REPORT LUN
914 * command, and scan the resulting list of LUNs by calling
915 * scsi_probe_and_add_lun.
917 * Modifies sdevscan->lun.
920 * 0: scan completed (or no memory, so further scanning is futile)
921 * 1: no report lun scan, or not configured
923 static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
927 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
930 unsigned int num_luns;
931 unsigned int retries;
932 struct scsi_lun *lunp, *lun_data;
933 struct scsi_request *sreq;
937 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
938 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
939 * support more than 8 LUNs.
941 if ((bflags & BLIST_NOREPORTLUN) ||
942 sdev->scsi_level < SCSI_2 ||
943 (sdev->scsi_level < SCSI_3 &&
944 (!(bflags & BLIST_REPORTLUN2) || sdev->host->max_lun <= 8)) )
946 if (bflags & BLIST_NOLUN)
949 sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
953 sprintf(devname, "host %d channel %d id %d",
954 sdev->host->host_no, sdev->channel, sdev->id);
957 * Allocate enough to hold the header (the same size as one scsi_lun)
958 * plus the max number of luns we are requesting.
960 * Reallocating and trying again (with the exact amount we need)
961 * would be nice, but then we need to somehow limit the size
962 * allocated based on the available memory and the limits of
963 * kmalloc - we don't want a kmalloc() failure of a huge value to
964 * prevent us from finding any LUNs on this target.
966 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
967 lun_data = kmalloc(length, GFP_ATOMIC |
968 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
970 goto out_release_request;
972 scsi_cmd[0] = REPORT_LUNS;
975 * bytes 1 - 5: reserved, set to zero.
977 memset(&scsi_cmd[1], 0, 5);
980 * bytes 6 - 9: length of the command.
982 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
983 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
984 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
985 scsi_cmd[9] = (unsigned char) length & 0xff;
987 scsi_cmd[10] = 0; /* reserved */
988 scsi_cmd[11] = 0; /* control */
989 sreq->sr_cmd_len = 0;
990 sreq->sr_data_direction = DMA_FROM_DEVICE;
993 * We can get a UNIT ATTENTION, for example a power on/reset, so
994 * retry a few times (like sd.c does for TEST UNIT READY).
995 * Experience shows some combinations of adapter/devices get at
996 * least two power on/resets.
998 * Illegal requests (for devices that do not support REPORT LUNS)
999 * should come through as a check condition, and will not generate
1002 for (retries = 0; retries < 3; retries++) {
1003 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1004 " REPORT LUNS to %s (try %d)\n", devname,
1006 scsi_wait_req(sreq, scsi_cmd, lun_data, length,
1007 SCSI_TIMEOUT + 4*HZ, 3);
1008 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1009 " %s (try %d) result 0x%x\n", sreq->sr_result
1010 ? "failed" : "successful", retries,
1012 if (sreq->sr_result == 0 ||
1013 sreq->sr_sense_buffer[2] != UNIT_ATTENTION)
1017 if (sreq->sr_result) {
1019 * The device probably does not support a REPORT LUN command
1022 scsi_release_request(sreq);
1025 scsi_release_request(sreq);
1028 * Get the length from the first four bytes of lun_data.
1030 data = (u8 *) lun_data->scsi_lun;
1031 length = ((data[0] << 24) | (data[1] << 16) |
1032 (data[2] << 8) | (data[3] << 0));
1034 num_luns = (length / sizeof(struct scsi_lun));
1035 if (num_luns > max_scsi_report_luns) {
1036 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1037 " of %d luns reported, try increasing"
1038 " max_scsi_report_luns.\n", devname,
1039 max_scsi_report_luns, num_luns);
1040 num_luns = max_scsi_report_luns;
1043 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUN scan of"
1044 " host %d channel %d id %d\n", sdev->host->host_no,
1045 sdev->channel, sdev->id));
1048 * Scan the luns in lun_data. The entry at offset 0 is really
1049 * the header, so start at 1 and go up to and including num_luns.
1051 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1052 lun = scsilun_to_int(lunp);
1055 * Check if the unused part of lunp is non-zero, and so
1056 * does not fit in lun.
1058 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1062 * Output an error displaying the LUN in byte order,
1063 * this differs from what linux would print for the
1064 * integer LUN value.
1066 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1067 data = (char *)lunp->scsi_lun;
1068 for (i = 0; i < sizeof(struct scsi_lun); i++)
1069 printk("%02x", data[i]);
1070 printk(" has a LUN larger than currently supported.\n");
1071 } else if (lun == 0) {
1073 * LUN 0 has already been scanned.
1075 } else if (lun > sdev->host->max_lun) {
1076 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1077 " than allowed by the host adapter\n",
1082 res = scsi_probe_and_add_lun(sdev->host, sdev->channel,
1083 sdev->id, lun, NULL, NULL, rescan);
1084 if (res == SCSI_SCAN_NO_RESPONSE) {
1086 * Got some results, but now none, abort.
1088 printk(KERN_ERR "scsi: Unexpected response"
1089 " from %s lun %d while scanning, scan"
1090 " aborted\n", devname, lun);
1099 out_release_request:
1100 scsi_release_request(sreq);
1103 * We are out of memory, don't try scanning any further.
1105 printk(ALLOC_FAILURE_MSG, __FUNCTION__);
1109 struct scsi_device *scsi_add_device(struct Scsi_Host *shost,
1110 uint channel, uint id, uint lun)
1112 struct scsi_device *sdev;
1115 down(&shost->scan_mutex);
1116 res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL, &sdev, 1);
1117 if (res != SCSI_SCAN_LUN_PRESENT)
1118 sdev = ERR_PTR(-ENODEV);
1119 up(&shost->scan_mutex);
1124 void scsi_rescan_device(struct device *dev)
1126 struct scsi_driver *drv;
1131 drv = to_scsi_driver(dev->driver);
1132 if (try_module_get(drv->owner)) {
1135 module_put(drv->owner);
1140 * scsi_scan_target - scan a target id, possibly including all LUNs on the
1142 * @sdevsca: Scsi_Device handle for scanning
1143 * @shost: host to scan
1144 * @channel: channel to scan
1145 * @id: target id to scan
1148 * Scan the target id on @shost, @channel, and @id. Scan at least LUN
1149 * 0, and possibly all LUNs on the target id.
1151 * Use the pre-allocated @sdevscan as a handle for the scanning. This
1152 * function sets sdevscan->host, sdevscan->id and sdevscan->lun; the
1153 * scanning functions modify sdevscan->lun.
1155 * First try a REPORT LUN scan, if that does not scan the target, do a
1156 * sequential scan of LUNs on the target id.
1158 static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
1159 unsigned int id, unsigned int lun, int rescan)
1163 struct scsi_device *sdev;
1165 if (shost->this_id == id)
1167 * Don't scan the host adapter
1171 if (lun != SCAN_WILD_CARD) {
1173 * Scan for a specific host/chan/id/lun.
1175 scsi_probe_and_add_lun(shost, channel, id, lun, NULL, NULL,
1181 * Scan LUN 0, if there is some response, scan further. Ideally, we
1182 * would not configure LUN 0 until all LUNs are scanned.
1184 res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev,
1186 if (res == SCSI_SCAN_LUN_PRESENT) {
1187 if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
1189 * The REPORT LUN did not scan the target,
1190 * do a sequential scan.
1192 scsi_sequential_lun_scan(shost, channel, id, bflags,
1193 res, sdev->scsi_level, rescan);
1194 } else if (res == SCSI_SCAN_TARGET_PRESENT) {
1196 * There's a target here, but lun 0 is offline so we
1197 * can't use the report_lun scan. Fall back to a
1198 * sequential lun scan with a bflags of SPARSELUN and
1199 * a default scsi level of SCSI_2
1201 scsi_sequential_lun_scan(shost, channel, id, BLIST_SPARSELUN,
1202 SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
1206 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1207 unsigned int id, unsigned int lun, int rescan)
1211 if (id == SCAN_WILD_CARD)
1212 for (id = 0; id < shost->max_id; ++id) {
1214 * XXX adapter drivers when possible (FCP, iSCSI)
1215 * could modify max_id to match the current max,
1216 * not the absolute max.
1218 * XXX add a shost id iterator, so for example,
1219 * the FC ID can be the same as a target id
1220 * without a huge overhead of sparse id's.
1222 if (shost->reverse_ordering)
1224 * Scan from high to low id.
1226 order_id = shost->max_id - id - 1;
1229 scsi_scan_target(shost, channel, order_id, lun, rescan);
1232 scsi_scan_target(shost, channel, id, lun, rescan);
1235 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1236 unsigned int id, unsigned int lun, int rescan)
1238 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
1239 __FUNCTION__, shost->host_no, channel, id, lun));
1241 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1242 ((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
1243 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1246 down(&shost->scan_mutex);
1247 if (channel == SCAN_WILD_CARD)
1248 for (channel = 0; channel <= shost->max_channel; channel++)
1249 scsi_scan_channel(shost, channel, id, lun, rescan);
1251 scsi_scan_channel(shost, channel, id, lun, rescan);
1252 up(&shost->scan_mutex);
1258 * scsi_scan_host - scan the given adapter
1259 * @shost: adapter to scan
1261 void scsi_scan_host(struct Scsi_Host *shost)
1263 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1267 void scsi_forget_host(struct Scsi_Host *shost)
1269 struct scsi_device *sdev, *tmp;
1270 unsigned long flags;
1273 * Ok, this look a bit strange. We always look for the first device
1274 * on the list as scsi_remove_device removes them from it - thus we
1275 * also have to release the lock.
1276 * We don't need to get another reference to the device before
1277 * releasing the lock as we already own the reference from
1278 * scsi_register_device that's release in scsi_remove_device. And
1279 * after that we don't look at sdev anymore.
1281 spin_lock_irqsave(shost->host_lock, flags);
1282 list_for_each_entry_safe(sdev, tmp, &shost->__devices, siblings) {
1283 spin_unlock_irqrestore(shost->host_lock, flags);
1284 scsi_remove_device(sdev);
1285 spin_lock_irqsave(shost->host_lock, flags);
1287 spin_unlock_irqrestore(shost->host_lock, flags);
1291 * Function: scsi_get_host_dev()
1293 * Purpose: Create a Scsi_Device that points to the host adapter itself.
1295 * Arguments: SHpnt - Host that needs a Scsi_Device
1297 * Lock status: None assumed.
1299 * Returns: The Scsi_Device or NULL
1302 * Attach a single Scsi_Device to the Scsi_Host - this should
1303 * be made to look like a "pseudo-device" that points to the
1306 * Note - this device is not accessible from any high-level
1307 * drivers (including generics), which is probably not
1308 * optimal. We can add hooks later to attach
1310 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1312 struct scsi_device *sdev;
1314 sdev = scsi_alloc_sdev(shost, 0, shost->this_id, 0);
1322 * Function: scsi_free_host_dev()
1324 * Purpose: Free a scsi_device that points to the host adapter itself.
1326 * Arguments: SHpnt - Host that needs a Scsi_Device
1328 * Lock status: None assumed.
1334 void scsi_free_host_dev(struct scsi_device *sdev)
1336 BUG_ON(sdev->id != sdev->host->this_id);
1338 if (sdev->host->hostt->slave_destroy)
1339 sdev->host->hostt->slave_destroy(sdev);
1340 if (sdev->host->transportt->cleanup)
1341 sdev->host->transportt->cleanup(sdev);
1342 put_device(&sdev->sdev_gendev);