2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
12 * Bug correction thanks go to :
13 * Rik Faith <faith@cs.unc.edu>
14 * Tommy Thorn <tthorn>
15 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
24 * Added request_module("scsi_hostadapter") for kerneld:
25 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
26 * Bjorn Ekwall <bj0rn@blox.se>
29 * Major improvements to the timeout, abort, and reset processing,
30 * as well as performance modifications for large queue depths by
31 * Leonard N. Zubkoff <lnz@dandelion.com>
33 * Converted cli() code to spinlocks, Ingo Molnar
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
37 * out_of_space hacks, D. Gilbert (dpg) 990608
40 #include <linux/module.h>
41 #include <linux/moduleparam.h>
42 #include <linux/kernel.h>
43 #include <linux/timer.h>
44 #include <linux/string.h>
45 #include <linux/slab.h>
46 #include <linux/blkdev.h>
47 #include <linux/delay.h>
48 #include <linux/init.h>
49 #include <linux/completion.h>
50 #include <linux/unistd.h>
51 #include <linux/spinlock.h>
52 #include <linux/kmod.h>
53 #include <linux/interrupt.h>
54 #include <linux/notifier.h>
55 #include <linux/cpu.h>
56 #include <linux/mutex.h>
57 #include <linux/async.h>
58 #include <asm/unaligned.h>
60 #include <scsi/scsi.h>
61 #include <scsi/scsi_cmnd.h>
62 #include <scsi/scsi_dbg.h>
63 #include <scsi/scsi_device.h>
64 #include <scsi/scsi_driver.h>
65 #include <scsi/scsi_eh.h>
66 #include <scsi/scsi_host.h>
67 #include <scsi/scsi_tcq.h>
69 #include "scsi_priv.h"
70 #include "scsi_logging.h"
72 #define CREATE_TRACE_POINTS
73 #include <trace/events/scsi.h>
76 * Definitions and constants.
80 * Note - the initial logging level can be set here to log events at boot time.
81 * After the system is up, you may enable logging via the /proc interface.
83 unsigned int scsi_logging_level
;
84 #if defined(CONFIG_SCSI_LOGGING)
85 EXPORT_SYMBOL(scsi_logging_level
);
88 /* sd, scsi core and power management need to coordinate flushing async actions */
89 ASYNC_DOMAIN(scsi_sd_probe_domain
);
90 EXPORT_SYMBOL(scsi_sd_probe_domain
);
93 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
94 * asynchronous system resume operations. It is marked 'exclusive' to avoid
95 * being included in the async_synchronize_full() that is invoked by
98 ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain
);
99 EXPORT_SYMBOL(scsi_sd_pm_domain
);
102 * scsi_put_command - Free a scsi command block
103 * @cmd: command block to free
107 * Notes: The command must not belong to any lists.
109 void scsi_put_command(struct scsi_cmnd
*cmd
)
113 /* serious error if the command hasn't come from a device list */
114 spin_lock_irqsave(&cmd
->device
->list_lock
, flags
);
115 BUG_ON(list_empty(&cmd
->list
));
116 list_del_init(&cmd
->list
);
117 spin_unlock_irqrestore(&cmd
->device
->list_lock
, flags
);
119 BUG_ON(delayed_work_pending(&cmd
->abort_work
));
122 #ifdef CONFIG_SCSI_LOGGING
123 void scsi_log_send(struct scsi_cmnd
*cmd
)
128 * If ML QUEUE log level is greater than or equal to:
130 * 1: nothing (match completion)
132 * 2: log opcode + command of all commands + cmd address
138 if (unlikely(scsi_logging_level
)) {
139 level
= SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT
,
140 SCSI_LOG_MLQUEUE_BITS
);
142 scmd_printk(KERN_INFO
, cmd
,
143 "Send: scmd 0x%p\n", cmd
);
144 scsi_print_command(cmd
);
149 void scsi_log_completion(struct scsi_cmnd
*cmd
, int disposition
)
154 * If ML COMPLETE log level is greater than or equal to:
156 * 1: log disposition, result, opcode + command, and conditionally
157 * sense data for failures or non SUCCESS dispositions.
159 * 2: same as 1 but for all command completions.
163 * 4: same as 3 plus dump extra junk
165 if (unlikely(scsi_logging_level
)) {
166 level
= SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT
,
167 SCSI_LOG_MLCOMPLETE_BITS
);
168 if (((level
> 0) && (cmd
->result
|| disposition
!= SUCCESS
)) ||
170 scsi_print_result(cmd
, "Done", disposition
);
171 scsi_print_command(cmd
);
172 if (status_byte(cmd
->result
) & CHECK_CONDITION
)
173 scsi_print_sense(cmd
);
175 scmd_printk(KERN_INFO
, cmd
,
176 "scsi host busy %d failed %d\n",
177 atomic_read(&cmd
->device
->host
->host_busy
),
178 cmd
->device
->host
->host_failed
);
185 * scsi_cmd_get_serial - Assign a serial number to a command
186 * @host: the scsi host
187 * @cmd: command to assign serial number to
189 * Description: a serial number identifies a request for error recovery
190 * and debugging purposes. Protected by the Host_Lock of host.
192 void scsi_cmd_get_serial(struct Scsi_Host
*host
, struct scsi_cmnd
*cmd
)
194 cmd
->serial_number
= host
->cmd_serial_number
++;
195 if (cmd
->serial_number
== 0)
196 cmd
->serial_number
= host
->cmd_serial_number
++;
198 EXPORT_SYMBOL(scsi_cmd_get_serial
);
201 * scsi_finish_command - cleanup and pass command back to upper layer
204 * Description: Pass command off to upper layer for finishing of I/O
205 * request, waking processes that are waiting on results,
208 void scsi_finish_command(struct scsi_cmnd
*cmd
)
210 struct scsi_device
*sdev
= cmd
->device
;
211 struct scsi_target
*starget
= scsi_target(sdev
);
212 struct Scsi_Host
*shost
= sdev
->host
;
213 struct scsi_driver
*drv
;
214 unsigned int good_bytes
;
216 scsi_device_unbusy(sdev
);
219 * Clear the flags that say that the device/target/host is no longer
220 * capable of accepting new commands.
222 if (atomic_read(&shost
->host_blocked
))
223 atomic_set(&shost
->host_blocked
, 0);
224 if (atomic_read(&starget
->target_blocked
))
225 atomic_set(&starget
->target_blocked
, 0);
226 if (atomic_read(&sdev
->device_blocked
))
227 atomic_set(&sdev
->device_blocked
, 0);
230 * If we have valid sense information, then some kind of recovery
231 * must have taken place. Make a note of this.
233 if (SCSI_SENSE_VALID(cmd
))
234 cmd
->result
|= (DRIVER_SENSE
<< 24);
236 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO
, sdev
,
237 "Notifying upper driver of completion "
238 "(result %x)\n", cmd
->result
));
240 good_bytes
= scsi_bufflen(cmd
);
241 if (!blk_rq_is_passthrough(cmd
->request
)) {
242 int old_good_bytes
= good_bytes
;
243 drv
= scsi_cmd_to_driver(cmd
);
245 good_bytes
= drv
->done(cmd
);
247 * USB may not give sense identifying bad sector and
248 * simply return a residue instead, so subtract off the
249 * residue if drv->done() error processing indicates no
250 * change to the completion length.
252 if (good_bytes
== old_good_bytes
)
253 good_bytes
-= scsi_get_resid(cmd
);
255 scsi_io_completion(cmd
, good_bytes
);
259 * scsi_change_queue_depth - change a device's queue depth
260 * @sdev: SCSI Device in question
261 * @depth: number of commands allowed to be queued to the driver
263 * Sets the device queue depth and returns the new value.
265 int scsi_change_queue_depth(struct scsi_device
*sdev
, int depth
)
268 sdev
->queue_depth
= depth
;
272 if (sdev
->request_queue
)
273 blk_set_queue_depth(sdev
->request_queue
, depth
);
275 return sdev
->queue_depth
;
277 EXPORT_SYMBOL(scsi_change_queue_depth
);
280 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
281 * @sdev: SCSI Device in question
282 * @depth: Current number of outstanding SCSI commands on this device,
283 * not counting the one returned as QUEUE_FULL.
285 * Description: This function will track successive QUEUE_FULL events on a
286 * specific SCSI device to determine if and when there is a
287 * need to adjust the queue depth on the device.
289 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
290 * -1 - Drop back to untagged operation using host->cmd_per_lun
291 * as the untagged command depth
293 * Lock Status: None held on entry
295 * Notes: Low level drivers may call this at any time and we will do
296 * "The Right Thing." We are interrupt context safe.
298 int scsi_track_queue_full(struct scsi_device
*sdev
, int depth
)
302 * Don't let QUEUE_FULLs on the same
303 * jiffies count, they could all be from
306 if ((jiffies
>> 4) == (sdev
->last_queue_full_time
>> 4))
309 sdev
->last_queue_full_time
= jiffies
;
310 if (sdev
->last_queue_full_depth
!= depth
) {
311 sdev
->last_queue_full_count
= 1;
312 sdev
->last_queue_full_depth
= depth
;
314 sdev
->last_queue_full_count
++;
317 if (sdev
->last_queue_full_count
<= 10)
320 return scsi_change_queue_depth(sdev
, depth
);
322 EXPORT_SYMBOL(scsi_track_queue_full
);
325 * scsi_vpd_inquiry - Request a device provide us with a VPD page
326 * @sdev: The device to ask
327 * @buffer: Where to put the result
328 * @page: Which Vital Product Data to return
329 * @len: The length of the buffer
331 * This is an internal helper function. You probably want to use
332 * scsi_get_vpd_page instead.
334 * Returns size of the vpd page on success or a negative error number.
336 static int scsi_vpd_inquiry(struct scsi_device
*sdev
, unsigned char *buffer
,
337 u8 page
, unsigned len
)
340 unsigned char cmd
[16];
346 cmd
[1] = 1; /* EVPD */
350 cmd
[5] = 0; /* Control byte */
353 * I'm not convinced we need to try quite this hard to get VPD, but
354 * all the existing users tried this hard.
356 result
= scsi_execute_req(sdev
, cmd
, DMA_FROM_DEVICE
, buffer
,
357 len
, NULL
, 30 * HZ
, 3, NULL
);
361 /* Sanity check that we got the page back that we asked for */
362 if (buffer
[1] != page
)
365 return get_unaligned_be16(&buffer
[2]) + 4;
369 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
370 * @sdev: The device to ask
371 * @page: Which Vital Product Data to return
372 * @buf: where to store the VPD
373 * @buf_len: number of bytes in the VPD buffer area
375 * SCSI devices may optionally supply Vital Product Data. Each 'page'
376 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
377 * If the device supports this VPD page, this routine returns a pointer
378 * to a buffer containing the data from that page. The caller is
379 * responsible for calling kfree() on this pointer when it is no longer
380 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
382 int scsi_get_vpd_page(struct scsi_device
*sdev
, u8 page
, unsigned char *buf
,
387 if (sdev
->skip_vpd_pages
)
390 /* Ask for all the pages supported by this device */
391 result
= scsi_vpd_inquiry(sdev
, buf
, 0, buf_len
);
395 /* If the user actually wanted this page, we can skip the rest */
399 for (i
= 4; i
< min(result
, buf_len
); i
++)
403 if (i
< result
&& i
>= buf_len
)
404 /* ran off the end of the buffer, give us benefit of doubt */
406 /* The device claims it doesn't support the requested page */
410 result
= scsi_vpd_inquiry(sdev
, buf
, page
, buf_len
);
419 EXPORT_SYMBOL_GPL(scsi_get_vpd_page
);
422 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
423 * @sdev: The device to ask
425 * Attach the 'Device Identification' VPD page (0x83) and the
426 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
427 * structure. This information can be used to identify the device
430 void scsi_attach_vpd(struct scsi_device
*sdev
)
433 int vpd_len
= SCSI_VPD_PG_LEN
;
434 int pg80_supported
= 0;
435 int pg83_supported
= 0;
436 unsigned char __rcu
*vpd_buf
, *orig_vpd_buf
= NULL
;
438 if (!scsi_device_supports_vpd(sdev
))
442 vpd_buf
= kmalloc(vpd_len
, GFP_KERNEL
);
446 /* Ask for all the pages supported by this device */
447 result
= scsi_vpd_inquiry(sdev
, vpd_buf
, 0, vpd_len
);
452 if (result
> vpd_len
) {
458 for (i
= 4; i
< result
; i
++) {
459 if (vpd_buf
[i
] == 0x80)
461 if (vpd_buf
[i
] == 0x83)
465 vpd_len
= SCSI_VPD_PG_LEN
;
467 if (pg80_supported
) {
469 vpd_buf
= kmalloc(vpd_len
, GFP_KERNEL
);
473 result
= scsi_vpd_inquiry(sdev
, vpd_buf
, 0x80, vpd_len
);
478 if (result
> vpd_len
) {
483 mutex_lock(&sdev
->inquiry_mutex
);
484 orig_vpd_buf
= sdev
->vpd_pg80
;
485 sdev
->vpd_pg80_len
= result
;
486 rcu_assign_pointer(sdev
->vpd_pg80
, vpd_buf
);
487 mutex_unlock(&sdev
->inquiry_mutex
);
493 vpd_len
= SCSI_VPD_PG_LEN
;
496 if (pg83_supported
) {
498 vpd_buf
= kmalloc(vpd_len
, GFP_KERNEL
);
502 result
= scsi_vpd_inquiry(sdev
, vpd_buf
, 0x83, vpd_len
);
507 if (result
> vpd_len
) {
512 mutex_lock(&sdev
->inquiry_mutex
);
513 orig_vpd_buf
= sdev
->vpd_pg83
;
514 sdev
->vpd_pg83_len
= result
;
515 rcu_assign_pointer(sdev
->vpd_pg83
, vpd_buf
);
516 mutex_unlock(&sdev
->inquiry_mutex
);
524 * scsi_report_opcode - Find out if a given command opcode is supported
525 * @sdev: scsi device to query
526 * @buffer: scratch buffer (must be at least 20 bytes long)
527 * @len: length of buffer
528 * @opcode: opcode for command to look up
530 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
531 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
532 * unsupported and 1 if the device claims to support the command.
534 int scsi_report_opcode(struct scsi_device
*sdev
, unsigned char *buffer
,
535 unsigned int len
, unsigned char opcode
)
537 unsigned char cmd
[16];
538 struct scsi_sense_hdr sshdr
;
541 if (sdev
->no_report_opcodes
|| sdev
->scsi_level
< SCSI_SPC_3
)
545 cmd
[0] = MAINTENANCE_IN
;
546 cmd
[1] = MI_REPORT_SUPPORTED_OPERATION_CODES
;
547 cmd
[2] = 1; /* One command format */
549 put_unaligned_be32(len
, &cmd
[6]);
550 memset(buffer
, 0, len
);
552 result
= scsi_execute_req(sdev
, cmd
, DMA_FROM_DEVICE
, buffer
, len
,
553 &sshdr
, 30 * HZ
, 3, NULL
);
555 if (result
&& scsi_sense_valid(&sshdr
) &&
556 sshdr
.sense_key
== ILLEGAL_REQUEST
&&
557 (sshdr
.asc
== 0x20 || sshdr
.asc
== 0x24) && sshdr
.ascq
== 0x00)
560 if ((buffer
[1] & 3) == 3) /* Command supported */
565 EXPORT_SYMBOL(scsi_report_opcode
);
568 * scsi_device_get - get an additional reference to a scsi_device
569 * @sdev: device to get a reference to
571 * Description: Gets a reference to the scsi_device and increments the use count
572 * of the underlying LLDD module. You must hold host_lock of the
573 * parent Scsi_Host or already have a reference when calling this.
575 * This will fail if a device is deleted or cancelled, or when the LLD module
576 * is in the process of being unloaded.
578 int scsi_device_get(struct scsi_device
*sdev
)
580 if (sdev
->sdev_state
== SDEV_DEL
|| sdev
->sdev_state
== SDEV_CANCEL
)
582 if (!get_device(&sdev
->sdev_gendev
))
584 if (!try_module_get(sdev
->host
->hostt
->module
))
585 goto fail_put_device
;
589 put_device(&sdev
->sdev_gendev
);
593 EXPORT_SYMBOL(scsi_device_get
);
596 * scsi_device_put - release a reference to a scsi_device
597 * @sdev: device to release a reference on.
599 * Description: Release a reference to the scsi_device and decrements the use
600 * count of the underlying LLDD module. The device is freed once the last
603 void scsi_device_put(struct scsi_device
*sdev
)
605 module_put(sdev
->host
->hostt
->module
);
606 put_device(&sdev
->sdev_gendev
);
608 EXPORT_SYMBOL(scsi_device_put
);
610 /* helper for shost_for_each_device, see that for documentation */
611 struct scsi_device
*__scsi_iterate_devices(struct Scsi_Host
*shost
,
612 struct scsi_device
*prev
)
614 struct list_head
*list
= (prev
? &prev
->siblings
: &shost
->__devices
);
615 struct scsi_device
*next
= NULL
;
618 spin_lock_irqsave(shost
->host_lock
, flags
);
619 while (list
->next
!= &shost
->__devices
) {
620 next
= list_entry(list
->next
, struct scsi_device
, siblings
);
621 /* skip devices that we can't get a reference to */
622 if (!scsi_device_get(next
))
627 spin_unlock_irqrestore(shost
->host_lock
, flags
);
630 scsi_device_put(prev
);
633 EXPORT_SYMBOL(__scsi_iterate_devices
);
636 * starget_for_each_device - helper to walk all devices of a target
637 * @starget: target whose devices we want to iterate over.
638 * @data: Opaque passed to each function call.
639 * @fn: Function to call on each device
641 * This traverses over each device of @starget. The devices have
642 * a reference that must be released by scsi_host_put when breaking
645 void starget_for_each_device(struct scsi_target
*starget
, void *data
,
646 void (*fn
)(struct scsi_device
*, void *))
648 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
649 struct scsi_device
*sdev
;
651 shost_for_each_device(sdev
, shost
) {
652 if ((sdev
->channel
== starget
->channel
) &&
653 (sdev
->id
== starget
->id
))
657 EXPORT_SYMBOL(starget_for_each_device
);
660 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
661 * @starget: target whose devices we want to iterate over.
662 * @data: parameter for callback @fn()
663 * @fn: callback function that is invoked for each device
665 * This traverses over each device of @starget. It does _not_
666 * take a reference on the scsi_device, so the whole loop must be
667 * protected by shost->host_lock.
669 * Note: The only reason why drivers would want to use this is because
670 * they need to access the device list in irq context. Otherwise you
671 * really want to use starget_for_each_device instead.
673 void __starget_for_each_device(struct scsi_target
*starget
, void *data
,
674 void (*fn
)(struct scsi_device
*, void *))
676 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
677 struct scsi_device
*sdev
;
679 __shost_for_each_device(sdev
, shost
) {
680 if ((sdev
->channel
== starget
->channel
) &&
681 (sdev
->id
== starget
->id
))
685 EXPORT_SYMBOL(__starget_for_each_device
);
688 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
689 * @starget: SCSI target pointer
690 * @lun: SCSI Logical Unit Number
692 * Description: Looks up the scsi_device with the specified @lun for a given
693 * @starget. The returned scsi_device does not have an additional
694 * reference. You must hold the host's host_lock over this call and
695 * any access to the returned scsi_device. A scsi_device in state
696 * SDEV_DEL is skipped.
698 * Note: The only reason why drivers should use this is because
699 * they need to access the device list in irq context. Otherwise you
700 * really want to use scsi_device_lookup_by_target instead.
702 struct scsi_device
*__scsi_device_lookup_by_target(struct scsi_target
*starget
,
705 struct scsi_device
*sdev
;
707 list_for_each_entry(sdev
, &starget
->devices
, same_target_siblings
) {
708 if (sdev
->sdev_state
== SDEV_DEL
)
716 EXPORT_SYMBOL(__scsi_device_lookup_by_target
);
719 * scsi_device_lookup_by_target - find a device given the target
720 * @starget: SCSI target pointer
721 * @lun: SCSI Logical Unit Number
723 * Description: Looks up the scsi_device with the specified @lun for a given
724 * @starget. The returned scsi_device has an additional reference that
725 * needs to be released with scsi_device_put once you're done with it.
727 struct scsi_device
*scsi_device_lookup_by_target(struct scsi_target
*starget
,
730 struct scsi_device
*sdev
;
731 struct Scsi_Host
*shost
= dev_to_shost(starget
->dev
.parent
);
734 spin_lock_irqsave(shost
->host_lock
, flags
);
735 sdev
= __scsi_device_lookup_by_target(starget
, lun
);
736 if (sdev
&& scsi_device_get(sdev
))
738 spin_unlock_irqrestore(shost
->host_lock
, flags
);
742 EXPORT_SYMBOL(scsi_device_lookup_by_target
);
745 * __scsi_device_lookup - find a device given the host (UNLOCKED)
746 * @shost: SCSI host pointer
747 * @channel: SCSI channel (zero if only one channel)
748 * @id: SCSI target number (physical unit number)
749 * @lun: SCSI Logical Unit Number
751 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
752 * for a given host. The returned scsi_device does not have an additional
753 * reference. You must hold the host's host_lock over this call and any access
754 * to the returned scsi_device.
756 * Note: The only reason why drivers would want to use this is because
757 * they need to access the device list in irq context. Otherwise you
758 * really want to use scsi_device_lookup instead.
760 struct scsi_device
*__scsi_device_lookup(struct Scsi_Host
*shost
,
761 uint channel
, uint id
, u64 lun
)
763 struct scsi_device
*sdev
;
765 list_for_each_entry(sdev
, &shost
->__devices
, siblings
) {
766 if (sdev
->channel
== channel
&& sdev
->id
== id
&&
773 EXPORT_SYMBOL(__scsi_device_lookup
);
776 * scsi_device_lookup - find a device given the host
777 * @shost: SCSI host pointer
778 * @channel: SCSI channel (zero if only one channel)
779 * @id: SCSI target number (physical unit number)
780 * @lun: SCSI Logical Unit Number
782 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
783 * for a given host. The returned scsi_device has an additional reference that
784 * needs to be released with scsi_device_put once you're done with it.
786 struct scsi_device
*scsi_device_lookup(struct Scsi_Host
*shost
,
787 uint channel
, uint id
, u64 lun
)
789 struct scsi_device
*sdev
;
792 spin_lock_irqsave(shost
->host_lock
, flags
);
793 sdev
= __scsi_device_lookup(shost
, channel
, id
, lun
);
794 if (sdev
&& scsi_device_get(sdev
))
796 spin_unlock_irqrestore(shost
->host_lock
, flags
);
800 EXPORT_SYMBOL(scsi_device_lookup
);
802 MODULE_DESCRIPTION("SCSI core");
803 MODULE_LICENSE("GPL");
805 module_param(scsi_logging_level
, int, S_IRUGO
|S_IWUSR
);
806 MODULE_PARM_DESC(scsi_logging_level
, "a bit mask of logging levels");
808 #ifdef CONFIG_SCSI_MQ_DEFAULT
809 bool scsi_use_blk_mq
= true;
811 bool scsi_use_blk_mq
= false;
813 module_param_named(use_blk_mq
, scsi_use_blk_mq
, bool, S_IWUSR
| S_IRUGO
);
815 static int __init
init_scsi(void)
819 error
= scsi_init_queue();
822 error
= scsi_init_procfs();
825 error
= scsi_init_devinfo();
828 error
= scsi_init_hosts();
830 goto cleanup_devlist
;
831 error
= scsi_init_sysctl();
834 error
= scsi_sysfs_register();
840 printk(KERN_NOTICE
"SCSI subsystem initialized\n");
853 printk(KERN_ERR
"SCSI subsystem failed to initialize, error = %d\n",
858 static void __exit
exit_scsi(void)
861 scsi_sysfs_unregister();
867 async_unregister_domain(&scsi_sd_probe_domain
);
870 subsys_initcall(init_scsi
);
871 module_exit(exit_scsi
);