blob: 73994e2ac2cb73e3636042945511735bbb17a13f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
5 *
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
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>
16 *
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
19 * enhancements.
20 *
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
23 *
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>
27 * (changed to kmod)
28 *
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>
32 *
33 * Converted cli() code to spinlocks, Ingo Molnar
34 *
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
36 *
37 * out_of_space hacks, D. Gilbert (dpg) 990608
38 */
39
40#include <linux/module.h>
41#include <linux/moduleparam.h>
42#include <linux/kernel.h>
43#include <linux/sched.h>
44#include <linux/timer.h>
45#include <linux/string.h>
46#include <linux/slab.h>
47#include <linux/blkdev.h>
48#include <linux/delay.h>
49#include <linux/init.h>
50#include <linux/completion.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <linux/unistd.h>
52#include <linux/spinlock.h>
53#include <linux/kmod.h>
54#include <linux/interrupt.h>
55#include <linux/notifier.h>
56#include <linux/cpu.h>
Arjan van de Ven0b950672006-01-11 13:16:10 +010057#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#include <scsi/scsi.h>
60#include <scsi/scsi_cmnd.h>
61#include <scsi/scsi_dbg.h>
62#include <scsi/scsi_device.h>
63#include <scsi/scsi_eh.h>
64#include <scsi/scsi_host.h>
65#include <scsi/scsi_tcq.h>
66#include <scsi/scsi_request.h>
67
68#include "scsi_priv.h"
69#include "scsi_logging.h"
70
Adrian Bunk52c1da32005-06-23 22:05:33 -070071static void scsi_done(struct scsi_cmnd *cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73/*
74 * Definitions and constants.
75 */
76
77#define MIN_RESET_DELAY (2*HZ)
78
79/* Do not call reset on error if we just did a reset within 15 sec. */
80#define MIN_RESET_PERIOD (15*HZ)
81
82/*
83 * Macro to determine the size of SCSI command. This macro takes vendor
84 * unique commands into account. SCSI commands in groups 6 and 7 are
85 * vendor unique and we will depend upon the command length being
86 * supplied correctly in cmd_len.
87 */
88#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
89 COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
90
91/*
92 * Note - the initial logging level can be set here to log events at boot time.
93 * After the system is up, you may enable logging via the /proc interface.
94 */
95unsigned int scsi_logging_level;
96#if defined(CONFIG_SCSI_LOGGING)
97EXPORT_SYMBOL(scsi_logging_level);
98#endif
99
100const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] = {
101 "Direct-Access ",
102 "Sequential-Access",
103 "Printer ",
104 "Processor ",
105 "WORM ",
106 "CD-ROM ",
107 "Scanner ",
108 "Optical Device ",
109 "Medium Changer ",
110 "Communications ",
111 "Unknown ",
112 "Unknown ",
113 "RAID ",
114 "Enclosure ",
James Bottomley7f602c52005-05-21 10:24:37 -0500115 "Direct-Access-RBC",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116};
117EXPORT_SYMBOL(scsi_device_types);
118
119/*
120 * Function: scsi_allocate_request
121 *
122 * Purpose: Allocate a request descriptor.
123 *
124 * Arguments: device - device for which we want a request
125 * gfp_mask - allocation flags passed to kmalloc
126 *
127 * Lock status: No locks assumed to be held. This function is SMP-safe.
128 *
129 * Returns: Pointer to request block.
130 */
131struct scsi_request *scsi_allocate_request(struct scsi_device *sdev,
Al Viroc53033f2005-10-21 03:22:08 -0400132 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133{
134 const int offset = ALIGN(sizeof(struct scsi_request), 4);
135 const int size = offset + sizeof(struct request);
136 struct scsi_request *sreq;
137
Jes Sorensen24669f752006-01-16 10:31:18 -0500138 sreq = kzalloc(size, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 if (likely(sreq != NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 sreq->sr_request = (struct request *)(((char *)sreq) + offset);
141 sreq->sr_device = sdev;
142 sreq->sr_host = sdev->host;
143 sreq->sr_magic = SCSI_REQ_MAGIC;
144 sreq->sr_data_direction = DMA_BIDIRECTIONAL;
145 }
146
147 return sreq;
148}
149EXPORT_SYMBOL(scsi_allocate_request);
150
151void __scsi_release_request(struct scsi_request *sreq)
152{
153 struct request *req = sreq->sr_request;
154
155 /* unlikely because the tag was usually ended earlier by the
156 * mid-layer. However, for layering reasons ULD's don't end
157 * the tag of commands they generate. */
158 if (unlikely(blk_rq_tagged(req))) {
159 unsigned long flags;
160 struct request_queue *q = req->q;
161
162 spin_lock_irqsave(q->queue_lock, flags);
163 blk_queue_end_tag(q, req);
164 spin_unlock_irqrestore(q->queue_lock, flags);
165 }
166
167
168 if (likely(sreq->sr_command != NULL)) {
169 struct scsi_cmnd *cmd = sreq->sr_command;
170
171 sreq->sr_command = NULL;
172 scsi_next_command(cmd);
173 }
174}
175
176/*
177 * Function: scsi_release_request
178 *
179 * Purpose: Release a request descriptor.
180 *
181 * Arguments: sreq - request to release
182 *
183 * Lock status: No locks assumed to be held. This function is SMP-safe.
184 */
185void scsi_release_request(struct scsi_request *sreq)
186{
187 __scsi_release_request(sreq);
188 kfree(sreq);
189}
190EXPORT_SYMBOL(scsi_release_request);
191
192struct scsi_host_cmd_pool {
193 kmem_cache_t *slab;
194 unsigned int users;
195 char *name;
196 unsigned int slab_flags;
Al Viroc53033f2005-10-21 03:22:08 -0400197 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198};
199
200static struct scsi_host_cmd_pool scsi_cmd_pool = {
201 .name = "scsi_cmd_cache",
202 .slab_flags = SLAB_HWCACHE_ALIGN,
203};
204
205static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
206 .name = "scsi_cmd_cache(DMA)",
207 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
208 .gfp_mask = __GFP_DMA,
209};
210
Arjan van de Ven0b950672006-01-11 13:16:10 +0100211static DEFINE_MUTEX(host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
213static struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost,
Al Viroc53033f2005-10-21 03:22:08 -0400214 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
216 struct scsi_cmnd *cmd;
217
218 cmd = kmem_cache_alloc(shost->cmd_pool->slab,
219 gfp_mask | shost->cmd_pool->gfp_mask);
220
221 if (unlikely(!cmd)) {
222 unsigned long flags;
223
224 spin_lock_irqsave(&shost->free_list_lock, flags);
225 if (likely(!list_empty(&shost->free_list))) {
226 cmd = list_entry(shost->free_list.next,
227 struct scsi_cmnd, list);
228 list_del_init(&cmd->list);
229 }
230 spin_unlock_irqrestore(&shost->free_list_lock, flags);
231 }
232
233 return cmd;
234}
235
236/*
237 * Function: scsi_get_command()
238 *
239 * Purpose: Allocate and setup a scsi command block
240 *
241 * Arguments: dev - parent scsi device
242 * gfp_mask- allocator flags
243 *
244 * Returns: The allocated scsi command structure.
245 */
Al Viroc53033f2005-10-21 03:22:08 -0400246struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
248 struct scsi_cmnd *cmd;
249
250 /* Bail if we can't get a reference to the device */
251 if (!get_device(&dev->sdev_gendev))
252 return NULL;
253
254 cmd = __scsi_get_command(dev->host, gfp_mask);
255
256 if (likely(cmd != NULL)) {
257 unsigned long flags;
258
259 memset(cmd, 0, sizeof(*cmd));
260 cmd->device = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 init_timer(&cmd->eh_timeout);
262 INIT_LIST_HEAD(&cmd->list);
263 spin_lock_irqsave(&dev->list_lock, flags);
264 list_add_tail(&cmd->list, &dev->cmd_list);
265 spin_unlock_irqrestore(&dev->list_lock, flags);
Matthew Dobson79e448b2005-11-21 21:32:29 -0800266 cmd->jiffies_at_alloc = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 } else
268 put_device(&dev->sdev_gendev);
269
270 return cmd;
271}
272EXPORT_SYMBOL(scsi_get_command);
273
274/*
275 * Function: scsi_put_command()
276 *
277 * Purpose: Free a scsi command block
278 *
279 * Arguments: cmd - command block to free
280 *
281 * Returns: Nothing.
282 *
283 * Notes: The command must not belong to any lists.
284 */
285void scsi_put_command(struct scsi_cmnd *cmd)
286{
287 struct scsi_device *sdev = cmd->device;
288 struct Scsi_Host *shost = sdev->host;
289 unsigned long flags;
290
291 /* serious error if the command hasn't come from a device list */
292 spin_lock_irqsave(&cmd->device->list_lock, flags);
293 BUG_ON(list_empty(&cmd->list));
294 list_del_init(&cmd->list);
295 spin_unlock(&cmd->device->list_lock);
296 /* changing locks here, don't need to restore the irq state */
297 spin_lock(&shost->free_list_lock);
298 if (unlikely(list_empty(&shost->free_list))) {
299 list_add(&cmd->list, &shost->free_list);
300 cmd = NULL;
301 }
302 spin_unlock_irqrestore(&shost->free_list_lock, flags);
303
304 if (likely(cmd != NULL))
305 kmem_cache_free(shost->cmd_pool->slab, cmd);
306
307 put_device(&sdev->sdev_gendev);
308}
309EXPORT_SYMBOL(scsi_put_command);
310
311/*
312 * Function: scsi_setup_command_freelist()
313 *
314 * Purpose: Setup the command freelist for a scsi host.
315 *
316 * Arguments: shost - host to allocate the freelist for.
317 *
318 * Returns: Nothing.
319 */
320int scsi_setup_command_freelist(struct Scsi_Host *shost)
321{
322 struct scsi_host_cmd_pool *pool;
323 struct scsi_cmnd *cmd;
324
325 spin_lock_init(&shost->free_list_lock);
326 INIT_LIST_HEAD(&shost->free_list);
327
328 /*
329 * Select a command slab for this host and create it if not
330 * yet existant.
331 */
Arjan van de Ven0b950672006-01-11 13:16:10 +0100332 mutex_lock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool);
334 if (!pool->users) {
335 pool->slab = kmem_cache_create(pool->name,
336 sizeof(struct scsi_cmnd), 0,
337 pool->slab_flags, NULL, NULL);
338 if (!pool->slab)
339 goto fail;
340 }
341
342 pool->users++;
343 shost->cmd_pool = pool;
Arjan van de Ven0b950672006-01-11 13:16:10 +0100344 mutex_unlock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /*
347 * Get one backup command for this host.
348 */
349 cmd = kmem_cache_alloc(shost->cmd_pool->slab,
350 GFP_KERNEL | shost->cmd_pool->gfp_mask);
351 if (!cmd)
352 goto fail2;
353 list_add(&cmd->list, &shost->free_list);
354 return 0;
355
356 fail2:
357 if (!--pool->users)
358 kmem_cache_destroy(pool->slab);
359 return -ENOMEM;
360 fail:
Arjan van de Ven0b950672006-01-11 13:16:10 +0100361 mutex_unlock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 return -ENOMEM;
363
364}
365
366/*
367 * Function: scsi_destroy_command_freelist()
368 *
369 * Purpose: Release the command freelist for a scsi host.
370 *
371 * Arguments: shost - host that's freelist is going to be destroyed
372 */
373void scsi_destroy_command_freelist(struct Scsi_Host *shost)
374{
375 while (!list_empty(&shost->free_list)) {
376 struct scsi_cmnd *cmd;
377
378 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
379 list_del_init(&cmd->list);
380 kmem_cache_free(shost->cmd_pool->slab, cmd);
381 }
382
Arjan van de Ven0b950672006-01-11 13:16:10 +0100383 mutex_lock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 if (!--shost->cmd_pool->users)
385 kmem_cache_destroy(shost->cmd_pool->slab);
Arjan van de Ven0b950672006-01-11 13:16:10 +0100386 mutex_unlock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387}
388
389#ifdef CONFIG_SCSI_LOGGING
390void scsi_log_send(struct scsi_cmnd *cmd)
391{
392 unsigned int level;
393 struct scsi_device *sdev;
394
395 /*
396 * If ML QUEUE log level is greater than or equal to:
397 *
398 * 1: nothing (match completion)
399 *
400 * 2: log opcode + command of all commands
401 *
402 * 3: same as 2 plus dump cmd address
403 *
404 * 4: same as 3 plus dump extra junk
405 */
406 if (unlikely(scsi_logging_level)) {
407 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
408 SCSI_LOG_MLQUEUE_BITS);
409 if (level > 1) {
410 sdev = cmd->device;
James Bottomley9ccfc752005-10-02 11:45:08 -0500411 sdev_printk(KERN_INFO, sdev, "send ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 if (level > 2)
413 printk("0x%p ", cmd);
414 /*
415 * spaces to match disposition and cmd->result
416 * output in scsi_log_completion.
417 */
418 printk(" ");
419 scsi_print_command(cmd);
420 if (level > 3) {
421 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
422 " done = 0x%p, queuecommand 0x%p\n",
423 cmd->buffer, cmd->bufflen,
424 cmd->done,
425 sdev->host->hostt->queuecommand);
426
427 }
428 }
429 }
430}
431
432void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
433{
434 unsigned int level;
435 struct scsi_device *sdev;
436
437 /*
438 * If ML COMPLETE log level is greater than or equal to:
439 *
440 * 1: log disposition, result, opcode + command, and conditionally
441 * sense data for failures or non SUCCESS dispositions.
442 *
443 * 2: same as 1 but for all command completions.
444 *
445 * 3: same as 2 plus dump cmd address
446 *
447 * 4: same as 3 plus dump extra junk
448 */
449 if (unlikely(scsi_logging_level)) {
450 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
451 SCSI_LOG_MLCOMPLETE_BITS);
452 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
453 (level > 1)) {
454 sdev = cmd->device;
James Bottomley9ccfc752005-10-02 11:45:08 -0500455 sdev_printk(KERN_INFO, sdev, "done ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 if (level > 2)
457 printk("0x%p ", cmd);
458 /*
459 * Dump truncated values, so we usually fit within
460 * 80 chars.
461 */
462 switch (disposition) {
463 case SUCCESS:
464 printk("SUCCESS");
465 break;
466 case NEEDS_RETRY:
467 printk("RETRY ");
468 break;
469 case ADD_TO_MLQUEUE:
470 printk("MLQUEUE");
471 break;
472 case FAILED:
473 printk("FAILED ");
474 break;
475 case TIMEOUT_ERROR:
476 /*
477 * If called via scsi_times_out.
478 */
479 printk("TIMEOUT");
480 break;
481 default:
482 printk("UNKNOWN");
483 }
484 printk(" %8x ", cmd->result);
485 scsi_print_command(cmd);
486 if (status_byte(cmd->result) & CHECK_CONDITION) {
487 /*
db9dff32005-04-03 14:53:59 -0500488 * XXX The scsi_print_sense formatting/prefix
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 * doesn't match this function.
490 */
491 scsi_print_sense("", cmd);
492 }
493 if (level > 3) {
494 printk(KERN_INFO "scsi host busy %d failed %d\n",
495 sdev->host->host_busy,
496 sdev->host->host_failed);
497 }
498 }
499 }
500}
501#endif
502
503/*
504 * Assign a serial number and pid to the request for error recovery
505 * and debugging purposes. Protected by the Host_Lock of host.
506 */
507static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
508{
509 cmd->serial_number = host->cmd_serial_number++;
510 if (cmd->serial_number == 0)
511 cmd->serial_number = host->cmd_serial_number++;
512
513 cmd->pid = host->cmd_pid++;
514 if (cmd->pid == 0)
515 cmd->pid = host->cmd_pid++;
516}
517
518/*
519 * Function: scsi_dispatch_command
520 *
521 * Purpose: Dispatch a command to the low-level driver.
522 *
523 * Arguments: cmd - command block we are dispatching.
524 *
525 * Notes:
526 */
527int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
528{
529 struct Scsi_Host *host = cmd->device->host;
530 unsigned long flags = 0;
531 unsigned long timeout;
532 int rtn = 0;
533
534 /* check if the device is still usable */
535 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
536 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
537 * returns an immediate error upwards, and signals
538 * that the device is no longer present */
539 cmd->result = DID_NO_CONNECT << 16;
540 atomic_inc(&cmd->device->iorequest_cnt);
Mike Christie69b52892005-05-01 14:47:15 -0500541 __scsi_done(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 /* return 0 (because the command has been processed) */
543 goto out;
544 }
545
546 /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */
547 if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) {
548 /*
549 * in SDEV_BLOCK, the command is just put back on the device
550 * queue. The suspend state has already blocked the queue so
551 * future requests should not occur until the device
552 * transitions out of the suspend state.
553 */
554 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
555
556 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
557
558 /*
559 * NOTE: rtn is still zero here because we don't need the
560 * queue to be plugged on return (it's already stopped)
561 */
562 goto out;
563 }
564
565 /*
566 * If SCSI-2 or lower, store the LUN value in cmnd.
567 */
James Bottomley4d7db042006-03-31 20:07:45 -0600568 if (cmd->device->scsi_level <= SCSI_2 &&
569 cmd->device->scsi_level != SCSI_UNKNOWN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
571 (cmd->device->lun << 5 & 0xe0);
572 }
573
574 /*
575 * We will wait MIN_RESET_DELAY clock ticks after the last reset so
576 * we can avoid the drive not being ready.
577 */
578 timeout = host->last_reset + MIN_RESET_DELAY;
579
580 if (host->resetting && time_before(jiffies, timeout)) {
581 int ticks_remaining = timeout - jiffies;
582 /*
583 * NOTE: This may be executed from within an interrupt
584 * handler! This is bad, but for now, it'll do. The irq
585 * level of the interrupt handler has been masked out by the
586 * platform dependent interrupt handling code already, so the
587 * sti() here will not cause another call to the SCSI host's
588 * interrupt handler (assuming there is one irq-level per
589 * host).
590 */
591 while (--ticks_remaining >= 0)
592 mdelay(1 + 999 / HZ);
593 host->resetting = 0;
594 }
595
596 /*
597 * AK: unlikely race here: for some reason the timer could
598 * expire before the serial number is set up below.
599 */
600 scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);
601
602 scsi_log_send(cmd);
603
604 /*
605 * We will use a queued command if possible, otherwise we will
606 * emulate the queuing and calling of completion function ourselves.
607 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 atomic_inc(&cmd->device->iorequest_cnt);
609
610 /*
611 * Before we queue this command, check if the command
612 * length exceeds what the host adapter can handle.
613 */
614 if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
615 SCSI_LOG_MLQUEUE(3,
616 printk("queuecommand : command too long.\n"));
617 cmd->result = (DID_ABORT << 16);
618
619 scsi_done(cmd);
620 goto out;
621 }
622
623 spin_lock_irqsave(host->host_lock, flags);
624 scsi_cmd_get_serial(host, cmd);
625
Mike Andersond2c9d9e2005-06-16 11:13:42 -0700626 if (unlikely(host->shost_state == SHOST_DEL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 cmd->result = (DID_NO_CONNECT << 16);
628 scsi_done(cmd);
629 } else {
630 rtn = host->hostt->queuecommand(cmd, scsi_done);
631 }
632 spin_unlock_irqrestore(host->host_lock, flags);
633 if (rtn) {
Tejun Heo d8c37e72005-05-14 00:46:08 +0900634 if (scsi_delete_timer(cmd)) {
635 atomic_inc(&cmd->device->iodone_cnt);
636 scsi_queue_insert(cmd,
637 (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ?
638 rtn : SCSI_MLQUEUE_HOST_BUSY);
639 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 SCSI_LOG_MLQUEUE(3,
641 printk("queuecommand : request rejected\n"));
642 }
643
644 out:
645 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
646 return rtn;
647}
648
649/*
650 * Function: scsi_init_cmd_from_req
651 *
652 * Purpose: Queue a SCSI command
653 * Purpose: Initialize a struct scsi_cmnd from a struct scsi_request
654 *
655 * Arguments: cmd - command descriptor.
656 * sreq - Request from the queue.
657 *
658 * Lock status: None needed.
659 *
660 * Returns: Nothing.
661 *
662 * Notes: Mainly transfer data from the request structure to the
663 * command structure. The request structure is allocated
664 * using the normal memory allocator, and requests can pile
665 * up to more or less any depth. The command structure represents
666 * a consumable resource, as these are allocated into a pool
667 * when the SCSI subsystem initializes. The preallocation is
668 * required so that in low-memory situations a disk I/O request
669 * won't cause the memory manager to try and write out a page.
670 * The request structure is generally used by ioctls and character
671 * devices.
672 */
673void scsi_init_cmd_from_req(struct scsi_cmnd *cmd, struct scsi_request *sreq)
674{
675 sreq->sr_command = cmd;
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 cmd->cmd_len = sreq->sr_cmd_len;
678 cmd->use_sg = sreq->sr_use_sg;
679
680 cmd->request = sreq->sr_request;
681 memcpy(cmd->data_cmnd, sreq->sr_cmnd, sizeof(cmd->data_cmnd));
682 cmd->serial_number = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 cmd->bufflen = sreq->sr_bufflen;
684 cmd->buffer = sreq->sr_buffer;
685 cmd->retries = 0;
686 cmd->allowed = sreq->sr_allowed;
687 cmd->done = sreq->sr_done;
688 cmd->timeout_per_command = sreq->sr_timeout_per_command;
689 cmd->sc_data_direction = sreq->sr_data_direction;
690 cmd->sglist_len = sreq->sr_sglist_len;
691 cmd->underflow = sreq->sr_underflow;
692 cmd->sc_request = sreq;
693 memcpy(cmd->cmnd, sreq->sr_cmnd, sizeof(sreq->sr_cmnd));
694
695 /*
696 * Zero the sense buffer. Some host adapters automatically request
697 * sense on error. 0 is not a valid sense code.
698 */
699 memset(cmd->sense_buffer, 0, sizeof(sreq->sr_sense_buffer));
700 cmd->request_buffer = sreq->sr_buffer;
701 cmd->request_bufflen = sreq->sr_bufflen;
702 cmd->old_use_sg = cmd->use_sg;
703 if (cmd->cmd_len == 0)
704 cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
705 cmd->old_cmd_len = cmd->cmd_len;
706 cmd->sc_old_data_direction = cmd->sc_data_direction;
707 cmd->old_underflow = cmd->underflow;
708
709 /*
710 * Start the timer ticking.
711 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 cmd->result = 0;
713
714 SCSI_LOG_MLQUEUE(3, printk("Leaving scsi_init_cmd_from_req()\n"));
715}
716
717/*
718 * Per-CPU I/O completion queue.
719 */
720static DEFINE_PER_CPU(struct list_head, scsi_done_q);
721
722/**
723 * scsi_done - Enqueue the finished SCSI command into the done queue.
724 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
725 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
726 *
727 * This function is the mid-level's (SCSI Core) interrupt routine, which
728 * regains ownership of the SCSI command (de facto) from a LLDD, and enqueues
729 * the command to the done queue for further processing.
730 *
731 * This is the producer of the done queue who enqueues at the tail.
732 *
733 * This function is interrupt context safe.
734 */
Adrian Bunk52c1da32005-06-23 22:05:33 -0700735static void scsi_done(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736{
737 /*
738 * We don't have to worry about this one timing out any more.
739 * If we are unable to remove the timer, then the command
740 * has already timed out. In which case, we have no choice but to
741 * let the timeout function run, as we have no idea where in fact
742 * that function could really be. It might be on another processor,
743 * etc, etc.
744 */
745 if (!scsi_delete_timer(cmd))
746 return;
747 __scsi_done(cmd);
748}
749
750/* Private entry to scsi_done() to complete a command when the timer
751 * isn't running --- used by scsi_times_out */
752void __scsi_done(struct scsi_cmnd *cmd)
753{
Jens Axboe1aea6432006-01-09 16:03:03 +0100754 struct request *rq = cmd->request;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756 /*
757 * Set the serial numbers back to zero
758 */
759 cmd->serial_number = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761 atomic_inc(&cmd->device->iodone_cnt);
762 if (cmd->result)
763 atomic_inc(&cmd->device->ioerr_cnt);
764
Jens Axboe1aea6432006-01-09 16:03:03 +0100765 BUG_ON(!rq);
766
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 /*
Jens Axboe1aea6432006-01-09 16:03:03 +0100768 * The uptodate/nbytes values don't matter, as we allow partial
769 * completes and thus will check this in the softirq callback
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 */
Jens Axboe1aea6432006-01-09 16:03:03 +0100771 rq->completion_data = cmd;
772 blk_complete_request(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773}
774
775/*
776 * Function: scsi_retry_command
777 *
778 * Purpose: Send a command back to the low level to be retried.
779 *
780 * Notes: This command is always executed in the context of the
781 * bottom half handler, or the error handler thread. Low
782 * level drivers should not become re-entrant as a result of
783 * this.
784 */
Jens Axboe1aea6432006-01-09 16:03:03 +0100785int scsi_retry_command(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786{
787 /*
788 * Restore the SCSI command state.
789 */
790 scsi_setup_cmd_retry(cmd);
791
792 /*
793 * Zero the sense information from the last time we tried
794 * this command.
795 */
796 memset(cmd->sense_buffer, 0, sizeof(cmd->sense_buffer));
797
798 return scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
799}
800
801/*
802 * Function: scsi_finish_command
803 *
804 * Purpose: Pass command off to upper layer for finishing of I/O
805 * request, waking processes that are waiting on results,
806 * etc.
807 */
808void scsi_finish_command(struct scsi_cmnd *cmd)
809{
810 struct scsi_device *sdev = cmd->device;
811 struct Scsi_Host *shost = sdev->host;
812 struct scsi_request *sreq;
813
814 scsi_device_unbusy(sdev);
815
816 /*
817 * Clear the flags which say that the device/host is no longer
818 * capable of accepting new commands. These are set in scsi_queue.c
819 * for both the queue full condition on a device, and for a
820 * host full condition on the host.
821 *
822 * XXX(hch): What about locking?
823 */
824 shost->host_blocked = 0;
825 sdev->device_blocked = 0;
826
827 /*
828 * If we have valid sense information, then some kind of recovery
829 * must have taken place. Make a note of this.
830 */
831 if (SCSI_SENSE_VALID(cmd))
832 cmd->result |= (DRIVER_SENSE << 24);
833
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400834 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
835 "Notifying upper driver of completion "
836 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 /*
839 * We can get here with use_sg=0, causing a panic in the upper level
840 */
841 cmd->use_sg = cmd->old_use_sg;
842
843 /*
844 * If there is an associated request structure, copy the data over
845 * before we call the completion function.
846 */
847 sreq = cmd->sc_request;
848 if (sreq) {
849 sreq->sr_result = sreq->sr_command->result;
850 if (sreq->sr_result) {
851 memcpy(sreq->sr_sense_buffer,
852 sreq->sr_command->sense_buffer,
853 sizeof(sreq->sr_sense_buffer));
854 }
855 }
856
857 cmd->done(cmd);
858}
859EXPORT_SYMBOL(scsi_finish_command);
860
861/*
862 * Function: scsi_adjust_queue_depth()
863 *
864 * Purpose: Allow low level drivers to tell us to change the queue depth
865 * on a specific SCSI device
866 *
867 * Arguments: sdev - SCSI Device in question
868 * tagged - Do we use tagged queueing (non-0) or do we treat
869 * this device as an untagged device (0)
870 * tags - Number of tags allowed if tagged queueing enabled,
871 * or number of commands the low level driver can
872 * queue up in non-tagged mode (as per cmd_per_lun).
873 *
874 * Returns: Nothing
875 *
876 * Lock Status: None held on entry
877 *
878 * Notes: Low level drivers may call this at any time and we will do
879 * the right thing depending on whether or not the device is
880 * currently active and whether or not it even has the
881 * command blocks built yet.
882 */
883void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
884{
885 unsigned long flags;
886
887 /*
888 * refuse to set tagged depth to an unworkable size
889 */
890 if (tags <= 0)
891 return;
892
893 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
894
895 /* Check to see if the queue is managed by the block layer
896 * if it is, and we fail to adjust the depth, exit */
897 if (blk_queue_tagged(sdev->request_queue) &&
898 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
899 goto out;
900
901 sdev->queue_depth = tags;
902 switch (tagged) {
903 case MSG_ORDERED_TAG:
904 sdev->ordered_tags = 1;
905 sdev->simple_tags = 1;
906 break;
907 case MSG_SIMPLE_TAG:
908 sdev->ordered_tags = 0;
909 sdev->simple_tags = 1;
910 break;
911 default:
James Bottomley9ccfc752005-10-02 11:45:08 -0500912 sdev_printk(KERN_WARNING, sdev,
913 "scsi_adjust_queue_depth, bad queue type, "
914 "disabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 case 0:
916 sdev->ordered_tags = sdev->simple_tags = 0;
917 sdev->queue_depth = tags;
918 break;
919 }
920 out:
921 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
922}
923EXPORT_SYMBOL(scsi_adjust_queue_depth);
924
925/*
926 * Function: scsi_track_queue_full()
927 *
928 * Purpose: This function will track successive QUEUE_FULL events on a
929 * specific SCSI device to determine if and when there is a
930 * need to adjust the queue depth on the device.
931 *
932 * Arguments: sdev - SCSI Device in question
933 * depth - Current number of outstanding SCSI commands on
934 * this device, not counting the one returned as
935 * QUEUE_FULL.
936 *
937 * Returns: 0 - No change needed
938 * >0 - Adjust queue depth to this new depth
939 * -1 - Drop back to untagged operation using host->cmd_per_lun
940 * as the untagged command depth
941 *
942 * Lock Status: None held on entry
943 *
944 * Notes: Low level drivers may call this at any time and we will do
945 * "The Right Thing." We are interrupt context safe.
946 */
947int scsi_track_queue_full(struct scsi_device *sdev, int depth)
948{
949 if ((jiffies >> 4) == sdev->last_queue_full_time)
950 return 0;
951
952 sdev->last_queue_full_time = (jiffies >> 4);
953 if (sdev->last_queue_full_depth != depth) {
954 sdev->last_queue_full_count = 1;
955 sdev->last_queue_full_depth = depth;
956 } else {
957 sdev->last_queue_full_count++;
958 }
959
960 if (sdev->last_queue_full_count <= 10)
961 return 0;
962 if (sdev->last_queue_full_depth < 8) {
963 /* Drop back to untagged */
964 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
965 return -1;
966 }
967
968 if (sdev->ordered_tags)
969 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
970 else
971 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
972 return depth;
973}
974EXPORT_SYMBOL(scsi_track_queue_full);
975
976/**
977 * scsi_device_get - get an addition reference to a scsi_device
978 * @sdev: device to get a reference to
979 *
980 * Gets a reference to the scsi_device and increments the use count
981 * of the underlying LLDD module. You must hold host_lock of the
982 * parent Scsi_Host or already have a reference when calling this.
983 */
984int scsi_device_get(struct scsi_device *sdev)
985{
986 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
987 return -ENXIO;
988 if (!get_device(&sdev->sdev_gendev))
989 return -ENXIO;
990 if (!try_module_get(sdev->host->hostt->module)) {
991 put_device(&sdev->sdev_gendev);
992 return -ENXIO;
993 }
994 return 0;
995}
996EXPORT_SYMBOL(scsi_device_get);
997
998/**
999 * scsi_device_put - release a reference to a scsi_device
1000 * @sdev: device to release a reference on.
1001 *
1002 * Release a reference to the scsi_device and decrements the use count
1003 * of the underlying LLDD module. The device is freed once the last
1004 * user vanishes.
1005 */
1006void scsi_device_put(struct scsi_device *sdev)
1007{
1008 module_put(sdev->host->hostt->module);
1009 put_device(&sdev->sdev_gendev);
1010}
1011EXPORT_SYMBOL(scsi_device_put);
1012
1013/* helper for shost_for_each_device, thus not documented */
1014struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1015 struct scsi_device *prev)
1016{
1017 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1018 struct scsi_device *next = NULL;
1019 unsigned long flags;
1020
1021 spin_lock_irqsave(shost->host_lock, flags);
1022 while (list->next != &shost->__devices) {
1023 next = list_entry(list->next, struct scsi_device, siblings);
1024 /* skip devices that we can't get a reference to */
1025 if (!scsi_device_get(next))
1026 break;
1027 next = NULL;
1028 list = list->next;
1029 }
1030 spin_unlock_irqrestore(shost->host_lock, flags);
1031
1032 if (prev)
1033 scsi_device_put(prev);
1034 return next;
1035}
1036EXPORT_SYMBOL(__scsi_iterate_devices);
1037
1038/**
1039 * starget_for_each_device - helper to walk all devices of a target
1040 * @starget: target whose devices we want to iterate over.
1041 *
1042 * This traverses over each devices of @shost. The devices have
1043 * a reference that must be released by scsi_host_put when breaking
1044 * out of the loop.
1045 */
1046void starget_for_each_device(struct scsi_target *starget, void * data,
1047 void (*fn)(struct scsi_device *, void *))
1048{
1049 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1050 struct scsi_device *sdev;
1051
1052 shost_for_each_device(sdev, shost) {
1053 if ((sdev->channel == starget->channel) &&
1054 (sdev->id == starget->id))
1055 fn(sdev, data);
1056 }
1057}
1058EXPORT_SYMBOL(starget_for_each_device);
1059
1060/**
1061 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1062 * @starget: SCSI target pointer
1063 * @lun: SCSI Logical Unit Number
1064 *
1065 * Looks up the scsi_device with the specified @lun for a give
1066 * @starget. The returned scsi_device does not have an additional
1067 * reference. You must hold the host's host_lock over this call and
1068 * any access to the returned scsi_device.
1069 *
1070 * Note: The only reason why drivers would want to use this is because
1071 * they're need to access the device list in irq context. Otherwise you
1072 * really want to use scsi_device_lookup_by_target instead.
1073 **/
1074struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
1075 uint lun)
1076{
1077 struct scsi_device *sdev;
1078
1079 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
1080 if (sdev->lun ==lun)
1081 return sdev;
1082 }
1083
1084 return NULL;
1085}
1086EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1087
1088/**
1089 * scsi_device_lookup_by_target - find a device given the target
1090 * @starget: SCSI target pointer
1091 * @lun: SCSI Logical Unit Number
1092 *
1093 * Looks up the scsi_device with the specified @channel, @id, @lun for a
1094 * give host. The returned scsi_device has an additional reference that
1095 * needs to be release with scsi_host_put once you're done with it.
1096 **/
1097struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
1098 uint lun)
1099{
1100 struct scsi_device *sdev;
1101 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1102 unsigned long flags;
1103
1104 spin_lock_irqsave(shost->host_lock, flags);
1105 sdev = __scsi_device_lookup_by_target(starget, lun);
1106 if (sdev && scsi_device_get(sdev))
1107 sdev = NULL;
1108 spin_unlock_irqrestore(shost->host_lock, flags);
1109
1110 return sdev;
1111}
1112EXPORT_SYMBOL(scsi_device_lookup_by_target);
1113
1114/**
1115 * scsi_device_lookup - find a device given the host (UNLOCKED)
1116 * @shost: SCSI host pointer
1117 * @channel: SCSI channel (zero if only one channel)
1118 * @pun: SCSI target number (physical unit number)
1119 * @lun: SCSI Logical Unit Number
1120 *
1121 * Looks up the scsi_device with the specified @channel, @id, @lun for a
1122 * give host. The returned scsi_device does not have an additional reference.
1123 * You must hold the host's host_lock over this call and any access to the
1124 * returned scsi_device.
1125 *
1126 * Note: The only reason why drivers would want to use this is because
1127 * they're need to access the device list in irq context. Otherwise you
1128 * really want to use scsi_device_lookup instead.
1129 **/
1130struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
1131 uint channel, uint id, uint lun)
1132{
1133 struct scsi_device *sdev;
1134
1135 list_for_each_entry(sdev, &shost->__devices, siblings) {
1136 if (sdev->channel == channel && sdev->id == id &&
1137 sdev->lun ==lun)
1138 return sdev;
1139 }
1140
1141 return NULL;
1142}
1143EXPORT_SYMBOL(__scsi_device_lookup);
1144
1145/**
1146 * scsi_device_lookup - find a device given the host
1147 * @shost: SCSI host pointer
1148 * @channel: SCSI channel (zero if only one channel)
1149 * @id: SCSI target number (physical unit number)
1150 * @lun: SCSI Logical Unit Number
1151 *
1152 * Looks up the scsi_device with the specified @channel, @id, @lun for a
1153 * give host. The returned scsi_device has an additional reference that
1154 * needs to be release with scsi_host_put once you're done with it.
1155 **/
1156struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1157 uint channel, uint id, uint lun)
1158{
1159 struct scsi_device *sdev;
1160 unsigned long flags;
1161
1162 spin_lock_irqsave(shost->host_lock, flags);
1163 sdev = __scsi_device_lookup(shost, channel, id, lun);
1164 if (sdev && scsi_device_get(sdev))
1165 sdev = NULL;
1166 spin_unlock_irqrestore(shost->host_lock, flags);
1167
1168 return sdev;
1169}
1170EXPORT_SYMBOL(scsi_device_lookup);
1171
1172/**
1173 * scsi_device_cancel - cancel outstanding IO to this device
1174 * @sdev: Pointer to struct scsi_device
1175 * @recovery: Boolean instructing function to recover device or not.
1176 *
1177 **/
1178int scsi_device_cancel(struct scsi_device *sdev, int recovery)
1179{
1180 struct scsi_cmnd *scmd;
1181 LIST_HEAD(active_list);
1182 struct list_head *lh, *lh_sf;
1183 unsigned long flags;
1184
1185 scsi_device_set_state(sdev, SDEV_CANCEL);
1186
1187 spin_lock_irqsave(&sdev->list_lock, flags);
1188 list_for_each_entry(scmd, &sdev->cmd_list, list) {
1189 if (scmd->request && scmd->request->rq_status != RQ_INACTIVE) {
1190 /*
1191 * If we are unable to remove the timer, it means
1192 * that the command has already timed out or
1193 * finished.
1194 */
1195 if (!scsi_delete_timer(scmd))
1196 continue;
1197 list_add_tail(&scmd->eh_entry, &active_list);
1198 }
1199 }
1200 spin_unlock_irqrestore(&sdev->list_lock, flags);
1201
1202 if (!list_empty(&active_list)) {
1203 list_for_each_safe(lh, lh_sf, &active_list) {
1204 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
1205 list_del_init(lh);
James Bottomley939647e2005-09-18 15:05:20 -05001206 if (recovery &&
1207 !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 scmd->result = (DID_ABORT << 16);
1209 scsi_finish_command(scmd);
1210 }
1211 }
1212 }
1213
1214 return 0;
1215}
1216EXPORT_SYMBOL(scsi_device_cancel);
1217
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218MODULE_DESCRIPTION("SCSI core");
1219MODULE_LICENSE("GPL");
1220
1221module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1222MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1223
1224static int __init init_scsi(void)
1225{
1226 int error, i;
1227
1228 error = scsi_init_queue();
1229 if (error)
1230 return error;
1231 error = scsi_init_procfs();
1232 if (error)
1233 goto cleanup_queue;
1234 error = scsi_init_devinfo();
1235 if (error)
1236 goto cleanup_procfs;
1237 error = scsi_init_hosts();
1238 if (error)
1239 goto cleanup_devlist;
1240 error = scsi_init_sysctl();
1241 if (error)
1242 goto cleanup_hosts;
1243 error = scsi_sysfs_register();
1244 if (error)
1245 goto cleanup_sysctl;
1246
KAMEZAWA Hiroyuki530bba62006-03-28 14:50:58 -08001247 for_each_possible_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 INIT_LIST_HEAD(&per_cpu(scsi_done_q, i));
1249
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1251 return 0;
1252
1253cleanup_sysctl:
1254 scsi_exit_sysctl();
1255cleanup_hosts:
1256 scsi_exit_hosts();
1257cleanup_devlist:
1258 scsi_exit_devinfo();
1259cleanup_procfs:
1260 scsi_exit_procfs();
1261cleanup_queue:
1262 scsi_exit_queue();
1263 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1264 -error);
1265 return error;
1266}
1267
1268static void __exit exit_scsi(void)
1269{
1270 scsi_sysfs_unregister();
1271 scsi_exit_sysctl();
1272 scsi_exit_hosts();
1273 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 scsi_exit_procfs();
1275 scsi_exit_queue();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276}
1277
1278subsys_initcall(init_scsi);
1279module_exit(exit_scsi);