4 * Copyright (C) 2000 Eric Youngdale,
5 * Copyright (C) 2002 Patrick Mansfield
7 * The general scanning/probing algorithm is as follows, exceptions are
8 * made to it depending on device specific flags, compilation options, and
9 * global variable (boot or module load time) settings.
11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
12 * device attached, a scsi_device is allocated and setup for it.
14 * For every id of every channel on the given host:
16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
17 * device or storage attached to LUN 0):
19 * If LUN 0 has a device attached, allocate and setup a
22 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
23 * all of the LUNs returned by the REPORT LUN; else,
24 * sequentially scan LUNs up until some maximum is reached,
25 * or a LUN is seen that cannot have a device attached to it.
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/init.h>
31 #include <linux/blkdev.h>
32 #include <linux/delay.h>
33 #include <linux/kthread.h>
34 #include <linux/spinlock.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_cmnd.h>
38 #include <scsi/scsi_device.h>
39 #include <scsi/scsi_driver.h>
40 #include <scsi/scsi_devinfo.h>
41 #include <scsi/scsi_host.h>
42 #include <scsi/scsi_transport.h>
43 #include <scsi/scsi_eh.h>
45 #include "scsi_priv.h"
46 #include "scsi_logging.h"
48 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
49 " SCSI scanning, some SCSI devices might not be configured\n"
54 #define SCSI_TIMEOUT (2*HZ)
57 * Prefix values for the SCSI id's (stored in sysfs name field)
59 #define SCSI_UID_SER_NUM 'S'
60 #define SCSI_UID_UNKNOWN 'Z'
63 * Return values of some of the scanning functions.
65 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
66 * includes allocation or general failures preventing IO from being sent.
68 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
71 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
74 #define SCSI_SCAN_NO_RESPONSE 0
75 #define SCSI_SCAN_TARGET_PRESENT 1
76 #define SCSI_SCAN_LUN_PRESENT 2
78 static const char *scsi_null_device_strs = "nullnullnullnull";
80 #define MAX_SCSI_LUNS 512
82 #ifdef CONFIG_SCSI_MULTI_LUN
83 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
85 static unsigned int max_scsi_luns = 1;
88 module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR);
89 MODULE_PARM_DESC(max_luns,
90 "last scsi LUN (should be between 1 and 2^32-1)");
92 #ifdef CONFIG_SCSI_SCAN_ASYNC
93 #define SCSI_SCAN_TYPE_DEFAULT "async"
95 #define SCSI_SCAN_TYPE_DEFAULT "sync"
98 static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
100 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
101 MODULE_PARM_DESC(scan, "sync, async or none");
104 * max_scsi_report_luns: the maximum number of LUNS that will be
105 * returned from the REPORT LUNS command. 8 times this value must
106 * be allocated. In theory this could be up to an 8 byte value, but
107 * in practice, the maximum number of LUNs suppored by any device
110 static unsigned int max_scsi_report_luns = 511;
112 module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
113 MODULE_PARM_DESC(max_report_luns,
114 "REPORT LUNS maximum number of LUNS received (should be"
115 " between 1 and 16384)");
117 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
119 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
120 MODULE_PARM_DESC(inq_timeout,
121 "Timeout (in seconds) waiting for devices to answer INQUIRY."
122 " Default is 5. Some non-compliant devices need more.");
124 /* This lock protects only this list */
125 static DEFINE_SPINLOCK(async_scan_lock);
126 static LIST_HEAD(scanning_hosts);
128 struct async_scan_data {
129 struct list_head list;
130 struct Scsi_Host *shost;
131 struct completion prev_finished;
135 * scsi_complete_async_scans - Wait for asynchronous scans to complete
137 * When this function returns, any host which started scanning before
138 * this function was called will have finished its scan. Hosts which
139 * started scanning after this function was called may or may not have
142 int scsi_complete_async_scans(void)
144 struct async_scan_data *data;
147 if (list_empty(&scanning_hosts))
149 /* If we can't get memory immediately, that's OK. Just
150 * sleep a little. Even if we never get memory, the async
151 * scans will finish eventually.
153 data = kmalloc(sizeof(*data), GFP_KERNEL);
159 init_completion(&data->prev_finished);
161 spin_lock(&async_scan_lock);
162 /* Check that there's still somebody else on the list */
163 if (list_empty(&scanning_hosts))
165 list_add_tail(&data->list, &scanning_hosts);
166 spin_unlock(&async_scan_lock);
168 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
169 wait_for_completion(&data->prev_finished);
171 spin_lock(&async_scan_lock);
172 list_del(&data->list);
173 if (!list_empty(&scanning_hosts)) {
174 struct async_scan_data *next = list_entry(scanning_hosts.next,
175 struct async_scan_data, list);
176 complete(&next->prev_finished);
179 spin_unlock(&async_scan_lock);
185 /* Only exported for the benefit of scsi_wait_scan */
186 EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
190 * For async scanning we need to wait for all the scans to complete before
191 * trying to mount the root fs. Otherwise non-modular drivers may not be ready
194 late_initcall(scsi_complete_async_scans);
198 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
199 * @sdev: scsi device to send command to
200 * @result: area to store the result of the MODE SENSE
203 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
204 * Called for BLIST_KEY devices.
206 static void scsi_unlock_floptical(struct scsi_device *sdev,
207 unsigned char *result)
209 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
211 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
212 scsi_cmd[0] = MODE_SENSE;
216 scsi_cmd[4] = 0x2a; /* size */
218 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
219 SCSI_TIMEOUT, 3, NULL);
223 * scsi_alloc_sdev - allocate and setup a scsi_Device
224 * @starget: which target to allocate a &scsi_device for
226 * @hostdata: usually NULL and set by ->slave_alloc instead
229 * Allocate, initialize for io, and return a pointer to a scsi_Device.
230 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
231 * adds scsi_Device to the appropriate list.
234 * scsi_Device pointer, or NULL on failure.
236 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
237 unsigned int lun, void *hostdata)
239 struct scsi_device *sdev;
240 int display_failure_msg = 1, ret;
241 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
242 extern void scsi_evt_thread(struct work_struct *work);
244 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
249 sdev->vendor = scsi_null_device_strs;
250 sdev->model = scsi_null_device_strs;
251 sdev->rev = scsi_null_device_strs;
253 sdev->id = starget->id;
255 sdev->channel = starget->channel;
256 sdev->sdev_state = SDEV_CREATED;
257 INIT_LIST_HEAD(&sdev->siblings);
258 INIT_LIST_HEAD(&sdev->same_target_siblings);
259 INIT_LIST_HEAD(&sdev->cmd_list);
260 INIT_LIST_HEAD(&sdev->starved_entry);
261 INIT_LIST_HEAD(&sdev->event_list);
262 spin_lock_init(&sdev->list_lock);
263 INIT_WORK(&sdev->event_work, scsi_evt_thread);
265 sdev->sdev_gendev.parent = get_device(&starget->dev);
266 sdev->sdev_target = starget;
268 /* usually NULL and set by ->slave_alloc instead */
269 sdev->hostdata = hostdata;
271 /* if the device needs this changing, it may do so in the
272 * slave_configure function */
273 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
276 * Some low level driver could use device->type
281 * Assume that the device will have handshaking problems,
282 * and then fix this field later if it turns out it
287 sdev->request_queue = scsi_alloc_queue(sdev);
288 if (!sdev->request_queue) {
289 /* release fn is set up in scsi_sysfs_device_initialise, so
290 * have to free and put manually here */
291 put_device(&starget->dev);
296 sdev->request_queue->queuedata = sdev;
297 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
299 scsi_sysfs_device_initialize(sdev);
301 if (shost->hostt->slave_alloc) {
302 ret = shost->hostt->slave_alloc(sdev);
305 * if LLDD reports slave not present, don't clutter
306 * console with alloc failure messages
309 display_failure_msg = 0;
310 goto out_device_destroy;
317 transport_destroy_device(&sdev->sdev_gendev);
318 put_device(&sdev->sdev_gendev);
320 if (display_failure_msg)
321 printk(ALLOC_FAILURE_MSG, __func__);
325 static void scsi_target_destroy(struct scsi_target *starget)
327 struct device *dev = &starget->dev;
328 struct Scsi_Host *shost = dev_to_shost(dev->parent);
331 transport_destroy_device(dev);
332 spin_lock_irqsave(shost->host_lock, flags);
333 if (shost->hostt->target_destroy)
334 shost->hostt->target_destroy(starget);
335 list_del_init(&starget->siblings);
336 spin_unlock_irqrestore(shost->host_lock, flags);
340 static void scsi_target_dev_release(struct device *dev)
342 struct device *parent = dev->parent;
343 struct scsi_target *starget = to_scsi_target(dev);
349 static struct device_type scsi_target_type = {
350 .name = "scsi_target",
351 .release = scsi_target_dev_release,
354 int scsi_is_target_device(const struct device *dev)
356 return dev->type == &scsi_target_type;
358 EXPORT_SYMBOL(scsi_is_target_device);
360 static struct scsi_target *__scsi_find_target(struct device *parent,
361 int channel, uint id)
363 struct scsi_target *starget, *found_starget = NULL;
364 struct Scsi_Host *shost = dev_to_shost(parent);
366 * Search for an existing target for this sdev.
368 list_for_each_entry(starget, &shost->__targets, siblings) {
369 if (starget->id == id &&
370 starget->channel == channel) {
371 found_starget = starget;
376 get_device(&found_starget->dev);
378 return found_starget;
382 * scsi_alloc_target - allocate a new or find an existing target
383 * @parent: parent of the target (need not be a scsi host)
384 * @channel: target channel number (zero if no channels)
385 * @id: target id number
387 * Return an existing target if one exists, provided it hasn't already
388 * gone into STARGET_DEL state, otherwise allocate a new target.
390 * The target is returned with an incremented reference, so the caller
391 * is responsible for both reaping and doing a last put
393 static struct scsi_target *scsi_alloc_target(struct device *parent,
394 int channel, uint id)
396 struct Scsi_Host *shost = dev_to_shost(parent);
397 struct device *dev = NULL;
399 const int size = sizeof(struct scsi_target)
400 + shost->transportt->target_size;
401 struct scsi_target *starget;
402 struct scsi_target *found_target;
405 starget = kzalloc(size, GFP_KERNEL);
407 printk(KERN_ERR "%s: allocation failure\n", __func__);
411 device_initialize(dev);
412 starget->reap_ref = 1;
413 dev->parent = get_device(parent);
414 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
415 #ifndef CONFIG_SYSFS_DEPRECATED
416 dev->bus = &scsi_bus_type;
418 dev->type = &scsi_target_type;
420 starget->channel = channel;
421 starget->can_queue = 0;
422 INIT_LIST_HEAD(&starget->siblings);
423 INIT_LIST_HEAD(&starget->devices);
424 starget->state = STARGET_CREATED;
425 starget->scsi_level = SCSI_2;
427 spin_lock_irqsave(shost->host_lock, flags);
429 found_target = __scsi_find_target(parent, channel, id);
433 list_add_tail(&starget->siblings, &shost->__targets);
434 spin_unlock_irqrestore(shost->host_lock, flags);
435 /* allocate and add */
436 transport_setup_device(dev);
437 if (shost->hostt->target_alloc) {
438 error = shost->hostt->target_alloc(starget);
441 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
442 /* don't want scsi_target_reap to do the final
443 * put because it will be under the host lock */
444 scsi_target_destroy(starget);
453 found_target->reap_ref++;
454 spin_unlock_irqrestore(shost->host_lock, flags);
455 if (found_target->state != STARGET_DEL) {
460 /* Unfortunately, we found a dying target; need to
461 * wait until it's dead before we can get a new one */
462 put_device(&found_target->dev);
463 flush_scheduled_work();
467 static void scsi_target_reap_usercontext(struct work_struct *work)
469 struct scsi_target *starget =
470 container_of(work, struct scsi_target, ew.work);
472 transport_remove_device(&starget->dev);
473 device_del(&starget->dev);
474 scsi_target_destroy(starget);
478 * scsi_target_reap - check to see if target is in use and destroy if not
479 * @starget: target to be checked
481 * This is used after removing a LUN or doing a last put of the target
482 * it checks atomically that nothing is using the target and removes
485 void scsi_target_reap(struct scsi_target *starget)
487 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
489 enum scsi_target_state state;
492 spin_lock_irqsave(shost->host_lock, flags);
493 state = starget->state;
494 empty = --starget->reap_ref == 0 &&
495 list_empty(&starget->devices) ? 1 : 0;
496 spin_unlock_irqrestore(shost->host_lock, flags);
501 BUG_ON(state == STARGET_DEL);
502 starget->state = STARGET_DEL;
503 if (state == STARGET_CREATED)
504 scsi_target_destroy(starget);
506 execute_in_process_context(scsi_target_reap_usercontext,
511 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string
512 * @s: INQUIRY result string to sanitize
513 * @len: length of the string
516 * The SCSI spec says that INQUIRY vendor, product, and revision
517 * strings must consist entirely of graphic ASCII characters,
518 * padded on the right with spaces. Since not all devices obey
519 * this rule, we will replace non-graphic or non-ASCII characters
520 * with spaces. Exception: a NUL character is interpreted as a
521 * string terminator, so all the following characters are set to
524 static void sanitize_inquiry_string(unsigned char *s, int len)
528 for (; len > 0; (--len, ++s)) {
531 if (terminated || *s < 0x20 || *s > 0x7e)
537 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
538 * @sdev: scsi_device to probe
539 * @inq_result: area to store the INQUIRY result
540 * @result_len: len of inq_result
541 * @bflags: store any bflags found here
544 * Probe the lun associated with @req using a standard SCSI INQUIRY;
546 * If the INQUIRY is successful, zero is returned and the
547 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
548 * are copied to the scsi_device any flags value is stored in *@bflags.
550 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
551 int result_len, int *bflags)
553 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
554 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
555 int response_len = 0;
556 int pass, count, result;
557 struct scsi_sense_hdr sshdr;
561 /* Perform up to 3 passes. The first pass uses a conservative
562 * transfer length of 36 unless sdev->inquiry_len specifies a
563 * different value. */
564 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
565 try_inquiry_len = first_inquiry_len;
569 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
570 "scsi scan: INQUIRY pass %d length %d\n",
571 pass, try_inquiry_len));
573 /* Each pass gets up to three chances to ignore Unit Attention */
574 for (count = 0; count < 3; ++count) {
577 memset(scsi_cmd, 0, 6);
578 scsi_cmd[0] = INQUIRY;
579 scsi_cmd[4] = (unsigned char) try_inquiry_len;
581 memset(inq_result, 0, try_inquiry_len);
583 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
584 inq_result, try_inquiry_len, &sshdr,
585 HZ / 2 + HZ * scsi_inq_timeout, 3,
588 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
590 result ? "failed" : "successful", result));
594 * not-ready to ready transition [asc/ascq=0x28/0x0]
595 * or power-on, reset [asc/ascq=0x29/0x0], continue.
596 * INQUIRY should not yield UNIT_ATTENTION
597 * but many buggy devices do so anyway.
599 if ((driver_byte(result) & DRIVER_SENSE) &&
600 scsi_sense_valid(&sshdr)) {
601 if ((sshdr.sense_key == UNIT_ATTENTION) &&
602 ((sshdr.asc == 0x28) ||
603 (sshdr.asc == 0x29)) &&
609 * if nothing was transferred, we try
610 * again. It's a workaround for some USB
613 if (resid == try_inquiry_len)
620 sanitize_inquiry_string(&inq_result[8], 8);
621 sanitize_inquiry_string(&inq_result[16], 16);
622 sanitize_inquiry_string(&inq_result[32], 4);
624 response_len = inq_result[4] + 5;
625 if (response_len > 255)
626 response_len = first_inquiry_len; /* sanity */
629 * Get any flags for this device.
631 * XXX add a bflags to scsi_device, and replace the
632 * corresponding bit fields in scsi_device, so bflags
633 * need not be passed as an argument.
635 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
638 /* When the first pass succeeds we gain information about
639 * what larger transfer lengths might work. */
641 if (BLIST_INQUIRY_36 & *bflags)
642 next_inquiry_len = 36;
643 else if (BLIST_INQUIRY_58 & *bflags)
644 next_inquiry_len = 58;
645 else if (sdev->inquiry_len)
646 next_inquiry_len = sdev->inquiry_len;
648 next_inquiry_len = response_len;
650 /* If more data is available perform the second pass */
651 if (next_inquiry_len > try_inquiry_len) {
652 try_inquiry_len = next_inquiry_len;
658 } else if (pass == 2) {
659 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
660 "Consider BLIST_INQUIRY_36 for this device\n",
663 /* If this pass failed, the third pass goes back and transfers
664 * the same amount as we successfully got in the first pass. */
665 try_inquiry_len = first_inquiry_len;
670 /* If the last transfer attempt got an error, assume the
671 * peripheral doesn't exist or is dead. */
675 /* Don't report any more data than the device says is valid */
676 sdev->inquiry_len = min(try_inquiry_len, response_len);
679 * XXX Abort if the response length is less than 36? If less than
680 * 32, the lookup of the device flags (above) could be invalid,
681 * and it would be possible to take an incorrect action - we do
682 * not want to hang because of a short INQUIRY. On the flip side,
683 * if the device is spun down or becoming ready (and so it gives a
684 * short INQUIRY), an abort here prevents any further use of the
685 * device, including spin up.
687 * On the whole, the best approach seems to be to assume the first
688 * 36 bytes are valid no matter what the device says. That's
689 * better than copying < 36 bytes to the inquiry-result buffer
690 * and displaying garbage for the Vendor, Product, or Revision
693 if (sdev->inquiry_len < 36) {
694 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
695 " using 36\n", sdev->inquiry_len);
696 sdev->inquiry_len = 36;
700 * Related to the above issue:
702 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
703 * and if not ready, sent a START_STOP to start (maybe spin up) and
704 * then send the INQUIRY again, since the INQUIRY can change after
705 * a device is initialized.
707 * Ideally, start a device if explicitly asked to do so. This
708 * assumes that a device is spun up on power on, spun down on
709 * request, and then spun up on request.
713 * The scanning code needs to know the scsi_level, even if no
714 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
715 * non-zero LUNs can be scanned.
717 sdev->scsi_level = inq_result[2] & 0x07;
718 if (sdev->scsi_level >= 2 ||
719 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
721 sdev->sdev_target->scsi_level = sdev->scsi_level;
727 * scsi_add_lun - allocate and fully initialze a scsi_device
728 * @sdev: holds information to be stored in the new scsi_device
729 * @inq_result: holds the result of a previous INQUIRY to the LUN
730 * @bflags: black/white list flag
731 * @async: 1 if this device is being scanned asynchronously
734 * Initialize the scsi_device @sdev. Optionally set fields based
735 * on values in *@bflags.
738 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
739 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
741 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
742 int *bflags, int async)
747 * XXX do not save the inquiry, since it can change underneath us,
748 * save just vendor/model/rev.
750 * Rather than save it and have an ioctl that retrieves the saved
751 * value, have an ioctl that executes the same INQUIRY code used
752 * in scsi_probe_lun, let user level programs doing INQUIRY
753 * scanning run at their own risk, or supply a user level program
754 * that can correctly scan.
758 * Copy at least 36 bytes of INQUIRY data, so that we don't
759 * dereference unallocated memory when accessing the Vendor,
760 * Product, and Revision strings. Badly behaved devices may set
761 * the INQUIRY Additional Length byte to a small value, indicating
762 * these strings are invalid, but often they contain plausible data
763 * nonetheless. It doesn't matter if the device sent < 36 bytes
764 * total, since scsi_probe_lun() initializes inq_result with 0s.
766 sdev->inquiry = kmemdup(inq_result,
767 max_t(size_t, sdev->inquiry_len, 36),
769 if (sdev->inquiry == NULL)
770 return SCSI_SCAN_NO_RESPONSE;
772 sdev->vendor = (char *) (sdev->inquiry + 8);
773 sdev->model = (char *) (sdev->inquiry + 16);
774 sdev->rev = (char *) (sdev->inquiry + 32);
776 if (*bflags & BLIST_ISROM) {
777 sdev->type = TYPE_ROM;
780 sdev->type = (inq_result[0] & 0x1f);
781 sdev->removable = (inq_result[1] & 0x80) >> 7;
784 switch (sdev->type) {
792 case TYPE_MEDIUM_CHANGER:
803 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
806 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
807 /* RBC and MMC devices can return SCSI-3 compliance and yet
808 * still not support REPORT LUNS, so make them act as
809 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
810 * specifically set */
811 if ((*bflags & BLIST_REPORTLUN2) == 0)
812 *bflags |= BLIST_NOREPORTLUN;
816 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
817 * spec says: The device server is capable of supporting the
818 * specified peripheral device type on this logical unit. However,
819 * the physical device is not currently connected to this logical
822 * The above is vague, as it implies that we could treat 001 and
823 * 011 the same. Stay compatible with previous code, and create a
824 * scsi_device for a PQ of 1
826 * Don't set the device offline here; rather let the upper
827 * level drivers eval the PQ to decide whether they should
828 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
831 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
832 sdev->lockable = sdev->removable;
833 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
835 if (sdev->scsi_level >= SCSI_3 ||
836 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
838 if (inq_result[7] & 0x60)
840 if (inq_result[7] & 0x10)
843 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
844 "ANSI: %d%s\n", scsi_device_type(sdev->type),
845 sdev->vendor, sdev->model, sdev->rev,
846 sdev->inq_periph_qual, inq_result[2] & 0x07,
847 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
849 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
850 !(*bflags & BLIST_NOTQ))
851 sdev->tagged_supported = 1;
854 * Some devices (Texel CD ROM drives) have handshaking problems
855 * when used with the Seagate controllers. borken is initialized
856 * to 1, and then set it to 0 here.
858 if ((*bflags & BLIST_BORKEN) == 0)
861 if (*bflags & BLIST_NO_ULD_ATTACH)
862 sdev->no_uld_attach = 1;
865 * Apparently some really broken devices (contrary to the SCSI
866 * standards) need to be selected without asserting ATN
868 if (*bflags & BLIST_SELECT_NO_ATN)
869 sdev->select_no_atn = 1;
872 * Maximum 512 sector transfer length
873 * broken RA4x00 Compaq Disk Array
875 if (*bflags & BLIST_MAX_512)
876 blk_queue_max_sectors(sdev->request_queue, 512);
879 * Some devices may not want to have a start command automatically
880 * issued when a device is added.
882 if (*bflags & BLIST_NOSTARTONADD)
883 sdev->no_start_on_add = 1;
885 if (*bflags & BLIST_SINGLELUN)
886 scsi_target(sdev)->single_lun = 1;
888 sdev->use_10_for_rw = 1;
890 if (*bflags & BLIST_MS_SKIP_PAGE_08)
891 sdev->skip_ms_page_8 = 1;
893 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
894 sdev->skip_ms_page_3f = 1;
896 if (*bflags & BLIST_USE_10_BYTE_MS)
897 sdev->use_10_for_ms = 1;
899 /* set the device running here so that slave configure
901 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
903 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
906 sdev_printk(KERN_ERR, sdev,
907 "in wrong state %s to complete scan\n",
908 scsi_device_state_name(sdev->sdev_state));
909 return SCSI_SCAN_NO_RESPONSE;
913 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
914 sdev->use_192_bytes_for_3f = 1;
916 if (*bflags & BLIST_NOT_LOCKABLE)
919 if (*bflags & BLIST_RETRY_HWERROR)
920 sdev->retry_hwerror = 1;
922 transport_configure_device(&sdev->sdev_gendev);
924 if (sdev->host->hostt->slave_configure) {
925 ret = sdev->host->hostt->slave_configure(sdev);
928 * if LLDD reports slave not present, don't clutter
929 * console with alloc failure messages
932 sdev_printk(KERN_ERR, sdev,
933 "failed to configure device\n");
935 return SCSI_SCAN_NO_RESPONSE;
940 * Ok, the device is now all set up, we can
941 * register it and tell the rest of the kernel
944 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
945 return SCSI_SCAN_NO_RESPONSE;
947 return SCSI_SCAN_LUN_PRESENT;
950 static inline void scsi_destroy_sdev(struct scsi_device *sdev)
952 scsi_device_set_state(sdev, SDEV_DEL);
953 if (sdev->host->hostt->slave_destroy)
954 sdev->host->hostt->slave_destroy(sdev);
955 transport_destroy_device(&sdev->sdev_gendev);
956 put_device(&sdev->sdev_gendev);
959 #ifdef CONFIG_SCSI_LOGGING
961 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
962 * @buf: Output buffer with at least end-first+1 bytes of space
963 * @inq: Inquiry buffer (input)
964 * @first: Offset of string into inq
965 * @end: Index after last character in inq
967 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
968 unsigned first, unsigned end)
970 unsigned term = 0, idx;
972 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
973 if (inq[idx+first] > ' ') {
974 buf[idx] = inq[idx+first];
986 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
987 * @starget: pointer to target device structure
988 * @lun: LUN of target device
989 * @bflagsp: store bflags here if not NULL
990 * @sdevp: probe the LUN corresponding to this scsi_device
991 * @rescan: if nonzero skip some code only needed on first scan
992 * @hostdata: passed to scsi_alloc_sdev()
995 * Call scsi_probe_lun, if a LUN with an attached device is found,
996 * allocate and set it up by calling scsi_add_lun.
999 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1000 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1001 * attached at the LUN
1002 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1004 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1005 uint lun, int *bflagsp,
1006 struct scsi_device **sdevp, int rescan,
1009 struct scsi_device *sdev;
1010 unsigned char *result;
1011 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1012 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1015 * The rescan flag is used as an optimization, the first scan of a
1016 * host adapter calls into here with rescan == 0.
1018 sdev = scsi_device_lookup_by_target(starget, lun);
1020 if (rescan || !scsi_device_created(sdev)) {
1021 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1022 "scsi scan: device exists on %s\n",
1023 dev_name(&sdev->sdev_gendev)));
1027 scsi_device_put(sdev);
1030 *bflagsp = scsi_get_device_flags(sdev,
1033 return SCSI_SCAN_LUN_PRESENT;
1035 scsi_device_put(sdev);
1037 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1041 result = kmalloc(result_len, GFP_ATOMIC |
1042 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1046 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1047 goto out_free_result;
1052 * result contains valid SCSI INQUIRY data.
1054 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
1056 * For a Peripheral qualifier 3 (011b), the SCSI
1057 * spec says: The device server is not capable of
1058 * supporting a physical device on this logical
1061 * For disks, this implies that there is no
1062 * logical disk configured at sdev->lun, but there
1063 * is a target id responding.
1065 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1066 " peripheral qualifier of 3, device not"
1069 SCSI_LOG_SCAN_BUS(1, {
1070 unsigned char vend[9];
1071 unsigned char mod[17];
1073 sdev_printk(KERN_INFO, sdev,
1074 "scsi scan: consider passing scsi_mod."
1075 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1076 scsi_inq_str(vend, result, 8, 16),
1077 scsi_inq_str(mod, result, 16, 32));
1082 res = SCSI_SCAN_TARGET_PRESENT;
1083 goto out_free_result;
1087 * Some targets may set slight variations of PQ and PDT to signal
1088 * that no LUN is present, so don't add sdev in these cases.
1089 * Two specific examples are:
1090 * 1) NetApp targets: return PQ=1, PDT=0x1f
1091 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1092 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1095 * 1) SCSI SPC-3, pp. 145-146
1096 * PQ=1: "A peripheral device having the specified peripheral
1097 * device type is not connected to this logical unit. However, the
1098 * device server is capable of supporting the specified peripheral
1099 * device type on this logical unit."
1100 * PDT=0x1f: "Unknown or no device type"
1101 * 2) USB UFI 1.0, p. 20
1102 * PDT=00h Direct-access device (floppy)
1103 * PDT=1Fh none (no FDD connected to the requested logical unit)
1105 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1106 (result[0] & 0x1f) == 0x1f &&
1107 !scsi_is_wlun(lun)) {
1108 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1109 "scsi scan: peripheral device type"
1110 " of 31, no device added\n"));
1111 res = SCSI_SCAN_TARGET_PRESENT;
1112 goto out_free_result;
1115 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1116 if (res == SCSI_SCAN_LUN_PRESENT) {
1117 if (bflags & BLIST_KEY) {
1119 scsi_unlock_floptical(sdev, result);
1126 if (res == SCSI_SCAN_LUN_PRESENT) {
1128 if (scsi_device_get(sdev) == 0) {
1131 __scsi_remove_device(sdev);
1132 res = SCSI_SCAN_NO_RESPONSE;
1136 scsi_destroy_sdev(sdev);
1142 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1143 * @starget: pointer to target structure to scan
1144 * @bflags: black/white list flag for LUN 0
1145 * @scsi_level: Which version of the standard does this device adhere to
1146 * @rescan: passed to scsi_probe_add_lun()
1149 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1150 * scanned) to some maximum lun until a LUN is found with no device
1151 * attached. Use the bflags to figure out any oddities.
1153 * Modifies sdevscan->lun.
1155 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1156 int bflags, int scsi_level, int rescan)
1158 unsigned int sparse_lun, lun, max_dev_lun;
1159 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1161 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
1162 "%s\n", dev_name(&starget->dev)));
1164 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1166 * If this device is known to support sparse multiple units,
1167 * override the other settings, and scan all of them. Normally,
1168 * SCSI-3 devices should be scanned via the REPORT LUNS.
1170 if (bflags & BLIST_SPARSELUN) {
1171 max_dev_lun = shost->max_lun;
1177 * If less than SCSI_1_CSS, and no special lun scaning, stop
1178 * scanning; this matches 2.4 behaviour, but could just be a bug
1179 * (to continue scanning a SCSI_1_CSS device).
1181 * This test is broken. We might not have any device on lun0 for
1182 * a sparselun device, and if that's the case then how would we
1183 * know the real scsi_level, eh? It might make sense to just not
1184 * scan any SCSI_1 device for non-0 luns, but that check would best
1185 * go into scsi_alloc_sdev() and just have it return null when asked
1186 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1188 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1189 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1194 * If this device is known to support multiple units, override
1195 * the other settings, and scan all of them.
1197 if (bflags & BLIST_FORCELUN)
1198 max_dev_lun = shost->max_lun;
1200 * REGAL CDC-4X: avoid hang after LUN 4
1202 if (bflags & BLIST_MAX5LUN)
1203 max_dev_lun = min(5U, max_dev_lun);
1205 * Do not scan SCSI-2 or lower device past LUN 7, unless
1208 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1209 max_dev_lun = min(8U, max_dev_lun);
1212 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1213 * until we reach the max, or no LUN is found and we are not
1216 for (lun = 1; lun < max_dev_lun; ++lun)
1217 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1218 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1224 * scsilun_to_int: convert a scsi_lun to an int
1225 * @scsilun: struct scsi_lun to be converted.
1228 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1229 * integer, and return the result. The caller must check for
1230 * truncation before using this function.
1233 * The struct scsi_lun is assumed to be four levels, with each level
1234 * effectively containing a SCSI byte-ordered (big endian) short; the
1235 * addressing bits of each level are ignored (the highest two bits).
1236 * For a description of the LUN format, post SCSI-3 see the SCSI
1237 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1239 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1240 * the integer: 0x0b030a04
1242 int scsilun_to_int(struct scsi_lun *scsilun)
1248 for (i = 0; i < sizeof(lun); i += 2)
1249 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1250 scsilun->scsi_lun[i + 1]) << (i * 8));
1253 EXPORT_SYMBOL(scsilun_to_int);
1256 * int_to_scsilun: reverts an int into a scsi_lun
1257 * @lun: integer to be reverted
1258 * @scsilun: struct scsi_lun to be set.
1261 * Reverts the functionality of the scsilun_to_int, which packed
1262 * an 8-byte lun value into an int. This routine unpacks the int
1263 * back into the lun value.
1264 * Note: the scsilun_to_int() routine does not truly handle all
1265 * 8bytes of the lun value. This functions restores only as much
1266 * as was set by the routine.
1269 * Given an integer : 0x0b030a04, this function returns a
1270 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1273 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1277 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1279 for (i = 0; i < sizeof(lun); i += 2) {
1280 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1281 scsilun->scsi_lun[i+1] = lun & 0xFF;
1285 EXPORT_SYMBOL(int_to_scsilun);
1288 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1289 * @starget: which target
1290 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1291 * @rescan: nonzero if we can skip code only needed on first scan
1294 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1295 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1297 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1298 * LUNs even if it's older than SCSI-3.
1299 * If BLIST_NOREPORTLUN is set, return 1 always.
1300 * If BLIST_NOLUN is set, return 0 always.
1303 * 0: scan completed (or no memory, so further scanning is futile)
1304 * 1: could not scan with REPORT LUN
1306 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1310 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1311 unsigned int length;
1313 unsigned int num_luns;
1314 unsigned int retries;
1316 struct scsi_lun *lunp, *lun_data;
1318 struct scsi_sense_hdr sshdr;
1319 struct scsi_device *sdev;
1320 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1324 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1325 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1326 * support more than 8 LUNs.
1328 if (bflags & BLIST_NOREPORTLUN)
1330 if (starget->scsi_level < SCSI_2 &&
1331 starget->scsi_level != SCSI_UNKNOWN)
1333 if (starget->scsi_level < SCSI_3 &&
1334 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1336 if (bflags & BLIST_NOLUN)
1339 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1340 sdev = scsi_alloc_sdev(starget, 0, NULL);
1343 if (scsi_device_get(sdev))
1347 sprintf(devname, "host %d channel %d id %d",
1348 shost->host_no, sdev->channel, sdev->id);
1351 * Allocate enough to hold the header (the same size as one scsi_lun)
1352 * plus the max number of luns we are requesting.
1354 * Reallocating and trying again (with the exact amount we need)
1355 * would be nice, but then we need to somehow limit the size
1356 * allocated based on the available memory and the limits of
1357 * kmalloc - we don't want a kmalloc() failure of a huge value to
1358 * prevent us from finding any LUNs on this target.
1360 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1361 lun_data = kmalloc(length, GFP_ATOMIC |
1362 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1364 printk(ALLOC_FAILURE_MSG, __func__);
1368 scsi_cmd[0] = REPORT_LUNS;
1371 * bytes 1 - 5: reserved, set to zero.
1373 memset(&scsi_cmd[1], 0, 5);
1376 * bytes 6 - 9: length of the command.
1378 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1379 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1380 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1381 scsi_cmd[9] = (unsigned char) length & 0xff;
1383 scsi_cmd[10] = 0; /* reserved */
1384 scsi_cmd[11] = 0; /* control */
1387 * We can get a UNIT ATTENTION, for example a power on/reset, so
1388 * retry a few times (like sd.c does for TEST UNIT READY).
1389 * Experience shows some combinations of adapter/devices get at
1390 * least two power on/resets.
1392 * Illegal requests (for devices that do not support REPORT LUNS)
1393 * should come through as a check condition, and will not generate
1396 for (retries = 0; retries < 3; retries++) {
1397 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1398 " REPORT LUNS to %s (try %d)\n", devname,
1401 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1402 lun_data, length, &sshdr,
1403 SCSI_TIMEOUT + 4 * HZ, 3, NULL);
1405 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1406 " %s (try %d) result 0x%x\n", result
1407 ? "failed" : "successful", retries, result));
1410 else if (scsi_sense_valid(&sshdr)) {
1411 if (sshdr.sense_key != UNIT_ATTENTION)
1418 * The device probably does not support a REPORT LUN command
1425 * Get the length from the first four bytes of lun_data.
1427 data = (u8 *) lun_data->scsi_lun;
1428 length = ((data[0] << 24) | (data[1] << 16) |
1429 (data[2] << 8) | (data[3] << 0));
1431 num_luns = (length / sizeof(struct scsi_lun));
1432 if (num_luns > max_scsi_report_luns) {
1433 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1434 " of %d luns reported, try increasing"
1435 " max_scsi_report_luns.\n", devname,
1436 max_scsi_report_luns, num_luns);
1437 num_luns = max_scsi_report_luns;
1440 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1441 "scsi scan: REPORT LUN scan\n"));
1444 * Scan the luns in lun_data. The entry at offset 0 is really
1445 * the header, so start at 1 and go up to and including num_luns.
1447 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1448 lun = scsilun_to_int(lunp);
1451 * Check if the unused part of lunp is non-zero, and so
1452 * does not fit in lun.
1454 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1458 * Output an error displaying the LUN in byte order,
1459 * this differs from what linux would print for the
1460 * integer LUN value.
1462 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1463 data = (char *)lunp->scsi_lun;
1464 for (i = 0; i < sizeof(struct scsi_lun); i++)
1465 printk("%02x", data[i]);
1466 printk(" has a LUN larger than currently supported.\n");
1467 } else if (lun > sdev->host->max_lun) {
1468 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1469 " than allowed by the host adapter\n",
1474 res = scsi_probe_and_add_lun(starget,
1475 lun, NULL, NULL, rescan, NULL);
1476 if (res == SCSI_SCAN_NO_RESPONSE) {
1478 * Got some results, but now none, abort.
1480 sdev_printk(KERN_ERR, sdev,
1481 "Unexpected response"
1482 " from lun %d while scanning, scan"
1492 scsi_device_put(sdev);
1493 if (scsi_device_created(sdev))
1495 * the sdev we used didn't appear in the report luns scan
1497 scsi_destroy_sdev(sdev);
1501 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1502 uint id, uint lun, void *hostdata)
1504 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1505 struct device *parent = &shost->shost_gendev;
1506 struct scsi_target *starget;
1508 if (strncmp(scsi_scan_type, "none", 4) == 0)
1509 return ERR_PTR(-ENODEV);
1511 starget = scsi_alloc_target(parent, channel, id);
1513 return ERR_PTR(-ENOMEM);
1515 mutex_lock(&shost->scan_mutex);
1516 if (!shost->async_scan)
1517 scsi_complete_async_scans();
1519 if (scsi_host_scan_allowed(shost))
1520 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1521 mutex_unlock(&shost->scan_mutex);
1522 scsi_target_reap(starget);
1523 put_device(&starget->dev);
1527 EXPORT_SYMBOL(__scsi_add_device);
1529 int scsi_add_device(struct Scsi_Host *host, uint channel,
1530 uint target, uint lun)
1532 struct scsi_device *sdev =
1533 __scsi_add_device(host, channel, target, lun, NULL);
1535 return PTR_ERR(sdev);
1537 scsi_device_put(sdev);
1540 EXPORT_SYMBOL(scsi_add_device);
1542 void scsi_rescan_device(struct device *dev)
1544 struct scsi_driver *drv;
1549 drv = to_scsi_driver(dev->driver);
1550 if (try_module_get(drv->owner)) {
1553 module_put(drv->owner);
1556 EXPORT_SYMBOL(scsi_rescan_device);
1558 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1559 unsigned int id, unsigned int lun, int rescan)
1561 struct Scsi_Host *shost = dev_to_shost(parent);
1564 struct scsi_target *starget;
1566 if (shost->this_id == id)
1568 * Don't scan the host adapter
1572 starget = scsi_alloc_target(parent, channel, id);
1576 if (lun != SCAN_WILD_CARD) {
1578 * Scan for a specific host/chan/id/lun.
1580 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1585 * Scan LUN 0, if there is some response, scan further. Ideally, we
1586 * would not configure LUN 0 until all LUNs are scanned.
1588 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1589 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1590 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1592 * The REPORT LUN did not scan the target,
1593 * do a sequential scan.
1595 scsi_sequential_lun_scan(starget, bflags,
1596 starget->scsi_level, rescan);
1600 /* now determine if the target has any children at all
1601 * and if not, nuke it */
1602 scsi_target_reap(starget);
1604 put_device(&starget->dev);
1608 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1609 * @parent: host to scan
1610 * @channel: channel to scan
1611 * @id: target id to scan
1612 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1613 * @rescan: passed to LUN scanning routines
1616 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1617 * and possibly all LUNs on the target id.
1619 * First try a REPORT LUN scan, if that does not scan the target, do a
1620 * sequential scan of LUNs on the target id.
1622 void scsi_scan_target(struct device *parent, unsigned int channel,
1623 unsigned int id, unsigned int lun, int rescan)
1625 struct Scsi_Host *shost = dev_to_shost(parent);
1627 if (strncmp(scsi_scan_type, "none", 4) == 0)
1630 mutex_lock(&shost->scan_mutex);
1631 if (!shost->async_scan)
1632 scsi_complete_async_scans();
1634 if (scsi_host_scan_allowed(shost))
1635 __scsi_scan_target(parent, channel, id, lun, rescan);
1636 mutex_unlock(&shost->scan_mutex);
1638 EXPORT_SYMBOL(scsi_scan_target);
1640 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1641 unsigned int id, unsigned int lun, int rescan)
1645 if (id == SCAN_WILD_CARD)
1646 for (id = 0; id < shost->max_id; ++id) {
1648 * XXX adapter drivers when possible (FCP, iSCSI)
1649 * could modify max_id to match the current max,
1650 * not the absolute max.
1652 * XXX add a shost id iterator, so for example,
1653 * the FC ID can be the same as a target id
1654 * without a huge overhead of sparse id's.
1656 if (shost->reverse_ordering)
1658 * Scan from high to low id.
1660 order_id = shost->max_id - id - 1;
1663 __scsi_scan_target(&shost->shost_gendev, channel,
1664 order_id, lun, rescan);
1667 __scsi_scan_target(&shost->shost_gendev, channel,
1671 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1672 unsigned int id, unsigned int lun, int rescan)
1674 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1676 __func__, channel, id, lun));
1678 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1679 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1680 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1683 mutex_lock(&shost->scan_mutex);
1684 if (!shost->async_scan)
1685 scsi_complete_async_scans();
1687 if (scsi_host_scan_allowed(shost)) {
1688 if (channel == SCAN_WILD_CARD)
1689 for (channel = 0; channel <= shost->max_channel;
1691 scsi_scan_channel(shost, channel, id, lun,
1694 scsi_scan_channel(shost, channel, id, lun, rescan);
1696 mutex_unlock(&shost->scan_mutex);
1701 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1703 struct scsi_device *sdev;
1704 shost_for_each_device(sdev, shost) {
1705 if (!scsi_host_scan_allowed(shost) ||
1706 scsi_sysfs_add_sdev(sdev) != 0)
1707 scsi_destroy_sdev(sdev);
1712 * scsi_prep_async_scan - prepare for an async scan
1713 * @shost: the host which will be scanned
1714 * Returns: a cookie to be passed to scsi_finish_async_scan()
1716 * Tells the midlayer this host is going to do an asynchronous scan.
1717 * It reserves the host's position in the scanning list and ensures
1718 * that other asynchronous scans started after this one won't affect the
1719 * ordering of the discovered devices.
1721 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1723 struct async_scan_data *data;
1724 unsigned long flags;
1726 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1729 if (shost->async_scan) {
1730 printk("%s called twice for host %d", __func__,
1736 data = kmalloc(sizeof(*data), GFP_KERNEL);
1739 data->shost = scsi_host_get(shost);
1742 init_completion(&data->prev_finished);
1744 mutex_lock(&shost->scan_mutex);
1745 spin_lock_irqsave(shost->host_lock, flags);
1746 shost->async_scan = 1;
1747 spin_unlock_irqrestore(shost->host_lock, flags);
1748 mutex_unlock(&shost->scan_mutex);
1750 spin_lock(&async_scan_lock);
1751 if (list_empty(&scanning_hosts))
1752 complete(&data->prev_finished);
1753 list_add_tail(&data->list, &scanning_hosts);
1754 spin_unlock(&async_scan_lock);
1764 * scsi_finish_async_scan - asynchronous scan has finished
1765 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1767 * All the devices currently attached to this host have been found.
1768 * This function announces all the devices it has found to the rest
1771 static void scsi_finish_async_scan(struct async_scan_data *data)
1773 struct Scsi_Host *shost;
1774 unsigned long flags;
1779 shost = data->shost;
1781 mutex_lock(&shost->scan_mutex);
1783 if (!shost->async_scan) {
1784 printk("%s called twice for host %d", __func__,
1787 mutex_unlock(&shost->scan_mutex);
1791 wait_for_completion(&data->prev_finished);
1793 scsi_sysfs_add_devices(shost);
1795 spin_lock_irqsave(shost->host_lock, flags);
1796 shost->async_scan = 0;
1797 spin_unlock_irqrestore(shost->host_lock, flags);
1799 mutex_unlock(&shost->scan_mutex);
1801 spin_lock(&async_scan_lock);
1802 list_del(&data->list);
1803 if (!list_empty(&scanning_hosts)) {
1804 struct async_scan_data *next = list_entry(scanning_hosts.next,
1805 struct async_scan_data, list);
1806 complete(&next->prev_finished);
1808 spin_unlock(&async_scan_lock);
1810 scsi_host_put(shost);
1814 static void do_scsi_scan_host(struct Scsi_Host *shost)
1816 if (shost->hostt->scan_finished) {
1817 unsigned long start = jiffies;
1818 if (shost->hostt->scan_start)
1819 shost->hostt->scan_start(shost);
1821 while (!shost->hostt->scan_finished(shost, jiffies - start))
1824 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1829 static int do_scan_async(void *_data)
1831 struct async_scan_data *data = _data;
1832 do_scsi_scan_host(data->shost);
1833 scsi_finish_async_scan(data);
1838 * scsi_scan_host - scan the given adapter
1839 * @shost: adapter to scan
1841 void scsi_scan_host(struct Scsi_Host *shost)
1843 struct task_struct *p;
1844 struct async_scan_data *data;
1846 if (strncmp(scsi_scan_type, "none", 4) == 0)
1849 data = scsi_prep_async_scan(shost);
1851 do_scsi_scan_host(shost);
1855 p = kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no);
1857 do_scan_async(data);
1859 EXPORT_SYMBOL(scsi_scan_host);
1861 void scsi_forget_host(struct Scsi_Host *shost)
1863 struct scsi_device *sdev;
1864 unsigned long flags;
1867 spin_lock_irqsave(shost->host_lock, flags);
1868 list_for_each_entry(sdev, &shost->__devices, siblings) {
1869 if (sdev->sdev_state == SDEV_DEL)
1871 spin_unlock_irqrestore(shost->host_lock, flags);
1872 __scsi_remove_device(sdev);
1875 spin_unlock_irqrestore(shost->host_lock, flags);
1879 * Function: scsi_get_host_dev()
1881 * Purpose: Create a scsi_device that points to the host adapter itself.
1883 * Arguments: SHpnt - Host that needs a scsi_device
1885 * Lock status: None assumed.
1887 * Returns: The scsi_device or NULL
1890 * Attach a single scsi_device to the Scsi_Host - this should
1891 * be made to look like a "pseudo-device" that points to the
1894 * Note - this device is not accessible from any high-level
1895 * drivers (including generics), which is probably not
1896 * optimal. We can add hooks later to attach
1898 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1900 struct scsi_device *sdev = NULL;
1901 struct scsi_target *starget;
1903 mutex_lock(&shost->scan_mutex);
1904 if (!scsi_host_scan_allowed(shost))
1906 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1910 sdev = scsi_alloc_sdev(starget, 0, NULL);
1912 sdev->sdev_gendev.parent = get_device(&starget->dev);
1915 scsi_target_reap(starget);
1916 put_device(&starget->dev);
1918 mutex_unlock(&shost->scan_mutex);
1921 EXPORT_SYMBOL(scsi_get_host_dev);
1924 * Function: scsi_free_host_dev()
1926 * Purpose: Free a scsi_device that points to the host adapter itself.
1928 * Arguments: SHpnt - Host that needs a scsi_device
1930 * Lock status: None assumed.
1936 void scsi_free_host_dev(struct scsi_device *sdev)
1938 BUG_ON(sdev->id != sdev->host->this_id);
1940 scsi_destroy_sdev(sdev);
1942 EXPORT_SYMBOL(scsi_free_host_dev);