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1/*
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/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
58#include <scsi/scsi.h>
59#include <scsi/scsi_cmnd.h>
60#include <scsi/scsi_dbg.h>
61#include <scsi/scsi_device.h>
62#include <scsi/scsi_driver.h>
63#include <scsi/scsi_eh.h>
64#include <scsi/scsi_host.h>
65#include <scsi/scsi_tcq.h>
66
67#include "scsi_priv.h"
68#include "scsi_logging.h"
69
70#define CREATE_TRACE_POINTS
71#include <trace/events/scsi.h>
72
73static void scsi_done(struct scsi_cmnd *cmd);
74
75/*
76 * Definitions and constants.
77 */
78
79#define MIN_RESET_DELAY (2*HZ)
80
81/* Do not call reset on error if we just did a reset within 15 sec. */
82#define MIN_RESET_PERIOD (15*HZ)
83
84/*
85 * Note - the initial logging level can be set here to log events at boot time.
86 * After the system is up, you may enable logging via the /proc interface.
87 */
88unsigned int scsi_logging_level;
89#if defined(CONFIG_SCSI_LOGGING)
90EXPORT_SYMBOL(scsi_logging_level);
91#endif
92
93/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
94 * You may not alter any existing entry (although adding new ones is
95 * encouraged once assigned by ANSI/INCITS T10
96 */
97static const char *const scsi_device_types[] = {
98 "Direct-Access ",
99 "Sequential-Access",
100 "Printer ",
101 "Processor ",
102 "WORM ",
103 "CD-ROM ",
104 "Scanner ",
105 "Optical Device ",
106 "Medium Changer ",
107 "Communications ",
108 "ASC IT8 ",
109 "ASC IT8 ",
110 "RAID ",
111 "Enclosure ",
112 "Direct-Access-RBC",
113 "Optical card ",
114 "Bridge controller",
115 "Object storage ",
116 "Automation/Drive ",
117};
118
119/**
120 * scsi_device_type - Return 17 char string indicating device type.
121 * @type: type number to look up
122 */
123
124const char * scsi_device_type(unsigned type)
125{
126 if (type == 0x1e)
127 return "Well-known LUN ";
128 if (type == 0x1f)
129 return "No Device ";
130 if (type >= ARRAY_SIZE(scsi_device_types))
131 return "Unknown ";
132 return scsi_device_types[type];
133}
134
135EXPORT_SYMBOL(scsi_device_type);
136
137struct scsi_host_cmd_pool {
138 struct kmem_cache *cmd_slab;
139 struct kmem_cache *sense_slab;
140 unsigned int users;
141 char *cmd_name;
142 char *sense_name;
143 unsigned int slab_flags;
144 gfp_t gfp_mask;
145};
146
147static struct scsi_host_cmd_pool scsi_cmd_pool = {
148 .cmd_name = "scsi_cmd_cache",
149 .sense_name = "scsi_sense_cache",
150 .slab_flags = SLAB_HWCACHE_ALIGN,
151};
152
153static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
154 .cmd_name = "scsi_cmd_cache(DMA)",
155 .sense_name = "scsi_sense_cache(DMA)",
156 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
157 .gfp_mask = __GFP_DMA,
158};
159
160static DEFINE_MUTEX(host_cmd_pool_mutex);
161
162/**
163 * scsi_pool_alloc_command - internal function to get a fully allocated command
164 * @pool: slab pool to allocate the command from
165 * @gfp_mask: mask for the allocation
166 *
167 * Returns a fully allocated command (with the allied sense buffer) or
168 * NULL on failure
169 */
170static struct scsi_cmnd *
171scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask)
172{
173 struct scsi_cmnd *cmd;
174
175 cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
176 if (!cmd)
177 return NULL;
178
179 cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
180 gfp_mask | pool->gfp_mask);
181 if (!cmd->sense_buffer) {
182 kmem_cache_free(pool->cmd_slab, cmd);
183 return NULL;
184 }
185
186 return cmd;
187}
188
189/**
190 * scsi_pool_free_command - internal function to release a command
191 * @pool: slab pool to allocate the command from
192 * @cmd: command to release
193 *
194 * the command must previously have been allocated by
195 * scsi_pool_alloc_command.
196 */
197static void
198scsi_pool_free_command(struct scsi_host_cmd_pool *pool,
199 struct scsi_cmnd *cmd)
200{
201 if (cmd->prot_sdb)
202 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
203
204 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
205 kmem_cache_free(pool->cmd_slab, cmd);
206}
207
208/**
209 * scsi_host_alloc_command - internal function to allocate command
210 * @shost: SCSI host whose pool to allocate from
211 * @gfp_mask: mask for the allocation
212 *
213 * Returns a fully allocated command with sense buffer and protection
214 * data buffer (where applicable) or NULL on failure
215 */
216static struct scsi_cmnd *
217scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
218{
219 struct scsi_cmnd *cmd;
220
221 cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
222 if (!cmd)
223 return NULL;
224
225 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
226 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
227
228 if (!cmd->prot_sdb) {
229 scsi_pool_free_command(shost->cmd_pool, cmd);
230 return NULL;
231 }
232 }
233
234 return cmd;
235}
236
237/**
238 * __scsi_get_command - Allocate a struct scsi_cmnd
239 * @shost: host to transmit command
240 * @gfp_mask: allocation mask
241 *
242 * Description: allocate a struct scsi_cmd from host's slab, recycling from the
243 * host's free_list if necessary.
244 */
245struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
246{
247 struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
248
249 if (unlikely(!cmd)) {
250 unsigned long flags;
251
252 spin_lock_irqsave(&shost->free_list_lock, flags);
253 if (likely(!list_empty(&shost->free_list))) {
254 cmd = list_entry(shost->free_list.next,
255 struct scsi_cmnd, list);
256 list_del_init(&cmd->list);
257 }
258 spin_unlock_irqrestore(&shost->free_list_lock, flags);
259
260 if (cmd) {
261 void *buf, *prot;
262
263 buf = cmd->sense_buffer;
264 prot = cmd->prot_sdb;
265
266 memset(cmd, 0, sizeof(*cmd));
267
268 cmd->sense_buffer = buf;
269 cmd->prot_sdb = prot;
270 }
271 }
272
273 return cmd;
274}
275EXPORT_SYMBOL_GPL(__scsi_get_command);
276
277/**
278 * scsi_get_command - Allocate and setup a scsi command block
279 * @dev: parent scsi device
280 * @gfp_mask: allocator flags
281 *
282 * Returns: The allocated scsi command structure.
283 */
284struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
285{
286 struct scsi_cmnd *cmd;
287
288 /* Bail if we can't get a reference to the device */
289 if (!get_device(&dev->sdev_gendev))
290 return NULL;
291
292 cmd = __scsi_get_command(dev->host, gfp_mask);
293
294 if (likely(cmd != NULL)) {
295 unsigned long flags;
296
297 cmd->device = dev;
298 INIT_LIST_HEAD(&cmd->list);
299 spin_lock_irqsave(&dev->list_lock, flags);
300 list_add_tail(&cmd->list, &dev->cmd_list);
301 spin_unlock_irqrestore(&dev->list_lock, flags);
302 cmd->jiffies_at_alloc = jiffies;
303 } else
304 put_device(&dev->sdev_gendev);
305
306 return cmd;
307}
308EXPORT_SYMBOL(scsi_get_command);
309
310/**
311 * __scsi_put_command - Free a struct scsi_cmnd
312 * @shost: dev->host
313 * @cmd: Command to free
314 * @dev: parent scsi device
315 */
316void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
317 struct device *dev)
318{
319 unsigned long flags;
320
321 /* changing locks here, don't need to restore the irq state */
322 spin_lock_irqsave(&shost->free_list_lock, flags);
323 if (unlikely(list_empty(&shost->free_list))) {
324 list_add(&cmd->list, &shost->free_list);
325 cmd = NULL;
326 }
327 spin_unlock_irqrestore(&shost->free_list_lock, flags);
328
329 if (likely(cmd != NULL))
330 scsi_pool_free_command(shost->cmd_pool, cmd);
331
332 put_device(dev);
333}
334EXPORT_SYMBOL(__scsi_put_command);
335
336/**
337 * scsi_put_command - Free a scsi command block
338 * @cmd: command block to free
339 *
340 * Returns: Nothing.
341 *
342 * Notes: The command must not belong to any lists.
343 */
344void scsi_put_command(struct scsi_cmnd *cmd)
345{
346 struct scsi_device *sdev = cmd->device;
347 unsigned long flags;
348
349 /* serious error if the command hasn't come from a device list */
350 spin_lock_irqsave(&cmd->device->list_lock, flags);
351 BUG_ON(list_empty(&cmd->list));
352 list_del_init(&cmd->list);
353 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
354
355 __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev);
356}
357EXPORT_SYMBOL(scsi_put_command);
358
359static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask)
360{
361 struct scsi_host_cmd_pool *retval = NULL, *pool;
362 /*
363 * Select a command slab for this host and create it if not
364 * yet existent.
365 */
366 mutex_lock(&host_cmd_pool_mutex);
367 pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
368 &scsi_cmd_pool;
369 if (!pool->users) {
370 pool->cmd_slab = kmem_cache_create(pool->cmd_name,
371 sizeof(struct scsi_cmnd), 0,
372 pool->slab_flags, NULL);
373 if (!pool->cmd_slab)
374 goto fail;
375
376 pool->sense_slab = kmem_cache_create(pool->sense_name,
377 SCSI_SENSE_BUFFERSIZE, 0,
378 pool->slab_flags, NULL);
379 if (!pool->sense_slab) {
380 kmem_cache_destroy(pool->cmd_slab);
381 goto fail;
382 }
383 }
384
385 pool->users++;
386 retval = pool;
387 fail:
388 mutex_unlock(&host_cmd_pool_mutex);
389 return retval;
390}
391
392static void scsi_put_host_cmd_pool(gfp_t gfp_mask)
393{
394 struct scsi_host_cmd_pool *pool;
395
396 mutex_lock(&host_cmd_pool_mutex);
397 pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
398 &scsi_cmd_pool;
399 /*
400 * This may happen if a driver has a mismatched get and put
401 * of the command pool; the driver should be implicated in
402 * the stack trace
403 */
404 BUG_ON(pool->users == 0);
405
406 if (!--pool->users) {
407 kmem_cache_destroy(pool->cmd_slab);
408 kmem_cache_destroy(pool->sense_slab);
409 }
410 mutex_unlock(&host_cmd_pool_mutex);
411}
412
413/**
414 * scsi_allocate_command - get a fully allocated SCSI command
415 * @gfp_mask: allocation mask
416 *
417 * This function is for use outside of the normal host based pools.
418 * It allocates the relevant command and takes an additional reference
419 * on the pool it used. This function *must* be paired with
420 * scsi_free_command which also has the identical mask, otherwise the
421 * free pool counts will eventually go wrong and you'll trigger a bug.
422 *
423 * This function should *only* be used by drivers that need a static
424 * command allocation at start of day for internal functions.
425 */
426struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask)
427{
428 struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
429
430 if (!pool)
431 return NULL;
432
433 return scsi_pool_alloc_command(pool, gfp_mask);
434}
435EXPORT_SYMBOL(scsi_allocate_command);
436
437/**
438 * scsi_free_command - free a command allocated by scsi_allocate_command
439 * @gfp_mask: mask used in the original allocation
440 * @cmd: command to free
441 *
442 * Note: using the original allocation mask is vital because that's
443 * what determines which command pool we use to free the command. Any
444 * mismatch will cause the system to BUG eventually.
445 */
446void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd)
447{
448 struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
449
450 /*
451 * this could trigger if the mask to scsi_allocate_command
452 * doesn't match this mask. Otherwise we're guaranteed that this
453 * succeeds because scsi_allocate_command must have taken a reference
454 * on the pool
455 */
456 BUG_ON(!pool);
457
458 scsi_pool_free_command(pool, cmd);
459 /*
460 * scsi_put_host_cmd_pool is called twice; once to release the
461 * reference we took above, and once to release the reference
462 * originally taken by scsi_allocate_command
463 */
464 scsi_put_host_cmd_pool(gfp_mask);
465 scsi_put_host_cmd_pool(gfp_mask);
466}
467EXPORT_SYMBOL(scsi_free_command);
468
469/**
470 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
471 * @shost: host to allocate the freelist for.
472 *
473 * Description: The command freelist protects against system-wide out of memory
474 * deadlock by preallocating one SCSI command structure for each host, so the
475 * system can always write to a swap file on a device associated with that host.
476 *
477 * Returns: Nothing.
478 */
479int scsi_setup_command_freelist(struct Scsi_Host *shost)
480{
481 struct scsi_cmnd *cmd;
482 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
483
484 spin_lock_init(&shost->free_list_lock);
485 INIT_LIST_HEAD(&shost->free_list);
486
487 shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask);
488
489 if (!shost->cmd_pool)
490 return -ENOMEM;
491
492 /*
493 * Get one backup command for this host.
494 */
495 cmd = scsi_host_alloc_command(shost, gfp_mask);
496 if (!cmd) {
497 scsi_put_host_cmd_pool(gfp_mask);
498 shost->cmd_pool = NULL;
499 return -ENOMEM;
500 }
501 list_add(&cmd->list, &shost->free_list);
502 return 0;
503}
504
505/**
506 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
507 * @shost: host whose freelist is going to be destroyed
508 */
509void scsi_destroy_command_freelist(struct Scsi_Host *shost)
510{
511 /*
512 * If cmd_pool is NULL the free list was not initialized, so
513 * do not attempt to release resources.
514 */
515 if (!shost->cmd_pool)
516 return;
517
518 while (!list_empty(&shost->free_list)) {
519 struct scsi_cmnd *cmd;
520
521 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
522 list_del_init(&cmd->list);
523 scsi_pool_free_command(shost->cmd_pool, cmd);
524 }
525 shost->cmd_pool = NULL;
526 scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL);
527}
528
529#ifdef CONFIG_SCSI_LOGGING
530void scsi_log_send(struct scsi_cmnd *cmd)
531{
532 unsigned int level;
533
534 /*
535 * If ML QUEUE log level is greater than or equal to:
536 *
537 * 1: nothing (match completion)
538 *
539 * 2: log opcode + command of all commands
540 *
541 * 3: same as 2 plus dump cmd address
542 *
543 * 4: same as 3 plus dump extra junk
544 */
545 if (unlikely(scsi_logging_level)) {
546 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
547 SCSI_LOG_MLQUEUE_BITS);
548 if (level > 1) {
549 scmd_printk(KERN_INFO, cmd, "Send: ");
550 if (level > 2)
551 printk("0x%p ", cmd);
552 printk("\n");
553 scsi_print_command(cmd);
554 if (level > 3) {
555 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
556 " queuecommand 0x%p\n",
557 scsi_sglist(cmd), scsi_bufflen(cmd),
558 cmd->device->host->hostt->queuecommand);
559
560 }
561 }
562 }
563}
564
565void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
566{
567 unsigned int level;
568
569 /*
570 * If ML COMPLETE log level is greater than or equal to:
571 *
572 * 1: log disposition, result, opcode + command, and conditionally
573 * sense data for failures or non SUCCESS dispositions.
574 *
575 * 2: same as 1 but for all command completions.
576 *
577 * 3: same as 2 plus dump cmd address
578 *
579 * 4: same as 3 plus dump extra junk
580 */
581 if (unlikely(scsi_logging_level)) {
582 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
583 SCSI_LOG_MLCOMPLETE_BITS);
584 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
585 (level > 1)) {
586 scmd_printk(KERN_INFO, cmd, "Done: ");
587 if (level > 2)
588 printk("0x%p ", cmd);
589 /*
590 * Dump truncated values, so we usually fit within
591 * 80 chars.
592 */
593 switch (disposition) {
594 case SUCCESS:
595 printk("SUCCESS\n");
596 break;
597 case NEEDS_RETRY:
598 printk("RETRY\n");
599 break;
600 case ADD_TO_MLQUEUE:
601 printk("MLQUEUE\n");
602 break;
603 case FAILED:
604 printk("FAILED\n");
605 break;
606 case TIMEOUT_ERROR:
607 /*
608 * If called via scsi_times_out.
609 */
610 printk("TIMEOUT\n");
611 break;
612 default:
613 printk("UNKNOWN\n");
614 }
615 scsi_print_result(cmd);
616 scsi_print_command(cmd);
617 if (status_byte(cmd->result) & CHECK_CONDITION)
618 scsi_print_sense("", cmd);
619 if (level > 3)
620 scmd_printk(KERN_INFO, cmd,
621 "scsi host busy %d failed %d\n",
622 cmd->device->host->host_busy,
623 cmd->device->host->host_failed);
624 }
625 }
626}
627#endif
628
629/**
630 * scsi_cmd_get_serial - Assign a serial number to a command
631 * @host: the scsi host
632 * @cmd: command to assign serial number to
633 *
634 * Description: a serial number identifies a request for error recovery
635 * and debugging purposes. Protected by the Host_Lock of host.
636 */
637void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
638{
639 cmd->serial_number = host->cmd_serial_number++;
640 if (cmd->serial_number == 0)
641 cmd->serial_number = host->cmd_serial_number++;
642}
643EXPORT_SYMBOL(scsi_cmd_get_serial);
644
645/**
646 * scsi_dispatch_command - Dispatch a command to the low-level driver.
647 * @cmd: command block we are dispatching.
648 *
649 * Return: nonzero return request was rejected and device's queue needs to be
650 * plugged.
651 */
652int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
653{
654 struct Scsi_Host *host = cmd->device->host;
655 unsigned long timeout;
656 int rtn = 0;
657
658 atomic_inc(&cmd->device->iorequest_cnt);
659
660 /* check if the device is still usable */
661 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
662 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
663 * returns an immediate error upwards, and signals
664 * that the device is no longer present */
665 cmd->result = DID_NO_CONNECT << 16;
666 scsi_done(cmd);
667 /* return 0 (because the command has been processed) */
668 goto out;
669 }
670
671 /* Check to see if the scsi lld made this device blocked. */
672 if (unlikely(scsi_device_blocked(cmd->device))) {
673 /*
674 * in blocked state, the command is just put back on
675 * the device queue. The suspend state has already
676 * blocked the queue so future requests should not
677 * occur until the device transitions out of the
678 * suspend state.
679 */
680
681 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
682
683 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
684
685 /*
686 * NOTE: rtn is still zero here because we don't need the
687 * queue to be plugged on return (it's already stopped)
688 */
689 goto out;
690 }
691
692 /*
693 * If SCSI-2 or lower, store the LUN value in cmnd.
694 */
695 if (cmd->device->scsi_level <= SCSI_2 &&
696 cmd->device->scsi_level != SCSI_UNKNOWN) {
697 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
698 (cmd->device->lun << 5 & 0xe0);
699 }
700
701 /*
702 * We will wait MIN_RESET_DELAY clock ticks after the last reset so
703 * we can avoid the drive not being ready.
704 */
705 timeout = host->last_reset + MIN_RESET_DELAY;
706
707 if (host->resetting && time_before(jiffies, timeout)) {
708 int ticks_remaining = timeout - jiffies;
709 /*
710 * NOTE: This may be executed from within an interrupt
711 * handler! This is bad, but for now, it'll do. The irq
712 * level of the interrupt handler has been masked out by the
713 * platform dependent interrupt handling code already, so the
714 * sti() here will not cause another call to the SCSI host's
715 * interrupt handler (assuming there is one irq-level per
716 * host).
717 */
718 while (--ticks_remaining >= 0)
719 mdelay(1 + 999 / HZ);
720 host->resetting = 0;
721 }
722
723 scsi_log_send(cmd);
724
725 /*
726 * Before we queue this command, check if the command
727 * length exceeds what the host adapter can handle.
728 */
729 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
730 SCSI_LOG_MLQUEUE(3,
731 printk("queuecommand : command too long. "
732 "cdb_size=%d host->max_cmd_len=%d\n",
733 cmd->cmd_len, cmd->device->host->max_cmd_len));
734 cmd->result = (DID_ABORT << 16);
735
736 scsi_done(cmd);
737 goto out;
738 }
739
740 if (unlikely(host->shost_state == SHOST_DEL)) {
741 cmd->result = (DID_NO_CONNECT << 16);
742 scsi_done(cmd);
743 } else {
744 trace_scsi_dispatch_cmd_start(cmd);
745 cmd->scsi_done = scsi_done;
746 rtn = host->hostt->queuecommand(host, cmd);
747 }
748
749 if (rtn) {
750 trace_scsi_dispatch_cmd_error(cmd, rtn);
751 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
752 rtn != SCSI_MLQUEUE_TARGET_BUSY)
753 rtn = SCSI_MLQUEUE_HOST_BUSY;
754
755 scsi_queue_insert(cmd, rtn);
756
757 SCSI_LOG_MLQUEUE(3,
758 printk("queuecommand : request rejected\n"));
759 }
760
761 out:
762 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
763 return rtn;
764}
765
766/**
767 * scsi_done - Enqueue the finished SCSI command into the done queue.
768 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
769 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
770 *
771 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
772 * which regains ownership of the SCSI command (de facto) from a LLDD, and
773 * enqueues the command to the done queue for further processing.
774 *
775 * This is the producer of the done queue who enqueues at the tail.
776 *
777 * This function is interrupt context safe.
778 */
779static void scsi_done(struct scsi_cmnd *cmd)
780{
781 trace_scsi_dispatch_cmd_done(cmd);
782 blk_complete_request(cmd->request);
783}
784
785/* Move this to a header if it becomes more generally useful */
786static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
787{
788 return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
789}
790
791/**
792 * scsi_finish_command - cleanup and pass command back to upper layer
793 * @cmd: the command
794 *
795 * Description: Pass command off to upper layer for finishing of I/O
796 * request, waking processes that are waiting on results,
797 * etc.
798 */
799void scsi_finish_command(struct scsi_cmnd *cmd)
800{
801 struct scsi_device *sdev = cmd->device;
802 struct scsi_target *starget = scsi_target(sdev);
803 struct Scsi_Host *shost = sdev->host;
804 struct scsi_driver *drv;
805 unsigned int good_bytes;
806
807 scsi_device_unbusy(sdev);
808
809 /*
810 * Clear the flags which say that the device/host is no longer
811 * capable of accepting new commands. These are set in scsi_queue.c
812 * for both the queue full condition on a device, and for a
813 * host full condition on the host.
814 *
815 * XXX(hch): What about locking?
816 */
817 shost->host_blocked = 0;
818 starget->target_blocked = 0;
819 sdev->device_blocked = 0;
820
821 /*
822 * If we have valid sense information, then some kind of recovery
823 * must have taken place. Make a note of this.
824 */
825 if (SCSI_SENSE_VALID(cmd))
826 cmd->result |= (DRIVER_SENSE << 24);
827
828 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
829 "Notifying upper driver of completion "
830 "(result %x)\n", cmd->result));
831
832 good_bytes = scsi_bufflen(cmd);
833 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
834 int old_good_bytes = good_bytes;
835 drv = scsi_cmd_to_driver(cmd);
836 if (drv->done)
837 good_bytes = drv->done(cmd);
838 /*
839 * USB may not give sense identifying bad sector and
840 * simply return a residue instead, so subtract off the
841 * residue if drv->done() error processing indicates no
842 * change to the completion length.
843 */
844 if (good_bytes == old_good_bytes)
845 good_bytes -= scsi_get_resid(cmd);
846 }
847 scsi_io_completion(cmd, good_bytes);
848}
849EXPORT_SYMBOL(scsi_finish_command);
850
851/**
852 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
853 * @sdev: SCSI Device in question
854 * @tagged: Do we use tagged queueing (non-0) or do we treat
855 * this device as an untagged device (0)
856 * @tags: Number of tags allowed if tagged queueing enabled,
857 * or number of commands the low level driver can
858 * queue up in non-tagged mode (as per cmd_per_lun).
859 *
860 * Returns: Nothing
861 *
862 * Lock Status: None held on entry
863 *
864 * Notes: Low level drivers may call this at any time and we will do
865 * the right thing depending on whether or not the device is
866 * currently active and whether or not it even has the
867 * command blocks built yet.
868 */
869void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
870{
871 unsigned long flags;
872
873 /*
874 * refuse to set tagged depth to an unworkable size
875 */
876 if (tags <= 0)
877 return;
878
879 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
880
881 /*
882 * Check to see if the queue is managed by the block layer.
883 * If it is, and we fail to adjust the depth, exit.
884 *
885 * Do not resize the tag map if it is a host wide share bqt,
886 * because the size should be the hosts's can_queue. If there
887 * is more IO than the LLD's can_queue (so there are not enuogh
888 * tags) request_fn's host queue ready check will handle it.
889 */
890 if (!sdev->host->bqt) {
891 if (blk_queue_tagged(sdev->request_queue) &&
892 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
893 goto out;
894 }
895
896 sdev->queue_depth = tags;
897 switch (tagged) {
898 case MSG_ORDERED_TAG:
899 sdev->ordered_tags = 1;
900 sdev->simple_tags = 1;
901 break;
902 case MSG_SIMPLE_TAG:
903 sdev->ordered_tags = 0;
904 sdev->simple_tags = 1;
905 break;
906 default:
907 sdev_printk(KERN_WARNING, sdev,
908 "scsi_adjust_queue_depth, bad queue type, "
909 "disabled\n");
910 case 0:
911 sdev->ordered_tags = sdev->simple_tags = 0;
912 sdev->queue_depth = tags;
913 break;
914 }
915 out:
916 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
917}
918EXPORT_SYMBOL(scsi_adjust_queue_depth);
919
920/**
921 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
922 * @sdev: SCSI Device in question
923 * @depth: Current number of outstanding SCSI commands on this device,
924 * not counting the one returned as QUEUE_FULL.
925 *
926 * Description: This function will track successive QUEUE_FULL events on a
927 * specific SCSI device to determine if and when there is a
928 * need to adjust the queue depth on the device.
929 *
930 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
931 * -1 - Drop back to untagged operation using host->cmd_per_lun
932 * as the untagged command depth
933 *
934 * Lock Status: None held on entry
935 *
936 * Notes: Low level drivers may call this at any time and we will do
937 * "The Right Thing." We are interrupt context safe.
938 */
939int scsi_track_queue_full(struct scsi_device *sdev, int depth)
940{
941
942 /*
943 * Don't let QUEUE_FULLs on the same
944 * jiffies count, they could all be from
945 * same event.
946 */
947 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
948 return 0;
949
950 sdev->last_queue_full_time = jiffies;
951 if (sdev->last_queue_full_depth != depth) {
952 sdev->last_queue_full_count = 1;
953 sdev->last_queue_full_depth = depth;
954 } else {
955 sdev->last_queue_full_count++;
956 }
957
958 if (sdev->last_queue_full_count <= 10)
959 return 0;
960 if (sdev->last_queue_full_depth < 8) {
961 /* Drop back to untagged */
962 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
963 return -1;
964 }
965
966 if (sdev->ordered_tags)
967 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
968 else
969 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
970 return depth;
971}
972EXPORT_SYMBOL(scsi_track_queue_full);
973
974/**
975 * scsi_vpd_inquiry - Request a device provide us with a VPD page
976 * @sdev: The device to ask
977 * @buffer: Where to put the result
978 * @page: Which Vital Product Data to return
979 * @len: The length of the buffer
980 *
981 * This is an internal helper function. You probably want to use
982 * scsi_get_vpd_page instead.
983 *
984 * Returns 0 on success or a negative error number.
985 */
986static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
987 u8 page, unsigned len)
988{
989 int result;
990 unsigned char cmd[16];
991
992 cmd[0] = INQUIRY;
993 cmd[1] = 1; /* EVPD */
994 cmd[2] = page;
995 cmd[3] = len >> 8;
996 cmd[4] = len & 0xff;
997 cmd[5] = 0; /* Control byte */
998
999 /*
1000 * I'm not convinced we need to try quite this hard to get VPD, but
1001 * all the existing users tried this hard.
1002 */
1003 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
1004 len, NULL, 30 * HZ, 3, NULL);
1005 if (result)
1006 return result;
1007
1008 /* Sanity check that we got the page back that we asked for */
1009 if (buffer[1] != page)
1010 return -EIO;
1011
1012 return 0;
1013}
1014
1015/**
1016 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
1017 * @sdev: The device to ask
1018 * @page: Which Vital Product Data to return
1019 * @buf: where to store the VPD
1020 * @buf_len: number of bytes in the VPD buffer area
1021 *
1022 * SCSI devices may optionally supply Vital Product Data. Each 'page'
1023 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
1024 * If the device supports this VPD page, this routine returns a pointer
1025 * to a buffer containing the data from that page. The caller is
1026 * responsible for calling kfree() on this pointer when it is no longer
1027 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
1028 */
1029int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
1030 int buf_len)
1031{
1032 int i, result;
1033
1034 /* Ask for all the pages supported by this device */
1035 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
1036 if (result)
1037 goto fail;
1038
1039 /* If the user actually wanted this page, we can skip the rest */
1040 if (page == 0)
1041 return 0;
1042
1043 for (i = 0; i < min((int)buf[3], buf_len - 4); i++)
1044 if (buf[i + 4] == page)
1045 goto found;
1046
1047 if (i < buf[3] && i >= buf_len - 4)
1048 /* ran off the end of the buffer, give us benefit of doubt */
1049 goto found;
1050 /* The device claims it doesn't support the requested page */
1051 goto fail;
1052
1053 found:
1054 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
1055 if (result)
1056 goto fail;
1057
1058 return 0;
1059
1060 fail:
1061 return -EINVAL;
1062}
1063EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
1064
1065/**
1066 * scsi_device_get - get an additional reference to a scsi_device
1067 * @sdev: device to get a reference to
1068 *
1069 * Description: Gets a reference to the scsi_device and increments the use count
1070 * of the underlying LLDD module. You must hold host_lock of the
1071 * parent Scsi_Host or already have a reference when calling this.
1072 */
1073int scsi_device_get(struct scsi_device *sdev)
1074{
1075 if (sdev->sdev_state == SDEV_DEL)
1076 return -ENXIO;
1077 if (!get_device(&sdev->sdev_gendev))
1078 return -ENXIO;
1079 /* We can fail this if we're doing SCSI operations
1080 * from module exit (like cache flush) */
1081 try_module_get(sdev->host->hostt->module);
1082
1083 return 0;
1084}
1085EXPORT_SYMBOL(scsi_device_get);
1086
1087/**
1088 * scsi_device_put - release a reference to a scsi_device
1089 * @sdev: device to release a reference on.
1090 *
1091 * Description: Release a reference to the scsi_device and decrements the use
1092 * count of the underlying LLDD module. The device is freed once the last
1093 * user vanishes.
1094 */
1095void scsi_device_put(struct scsi_device *sdev)
1096{
1097#ifdef CONFIG_MODULE_UNLOAD
1098 struct module *module = sdev->host->hostt->module;
1099
1100 /* The module refcount will be zero if scsi_device_get()
1101 * was called from a module removal routine */
1102 if (module && module_refcount(module) != 0)
1103 module_put(module);
1104#endif
1105 put_device(&sdev->sdev_gendev);
1106}
1107EXPORT_SYMBOL(scsi_device_put);
1108
1109/* helper for shost_for_each_device, see that for documentation */
1110struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1111 struct scsi_device *prev)
1112{
1113 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1114 struct scsi_device *next = NULL;
1115 unsigned long flags;
1116
1117 spin_lock_irqsave(shost->host_lock, flags);
1118 while (list->next != &shost->__devices) {
1119 next = list_entry(list->next, struct scsi_device, siblings);
1120 /* skip devices that we can't get a reference to */
1121 if (!scsi_device_get(next))
1122 break;
1123 next = NULL;
1124 list = list->next;
1125 }
1126 spin_unlock_irqrestore(shost->host_lock, flags);
1127
1128 if (prev)
1129 scsi_device_put(prev);
1130 return next;
1131}
1132EXPORT_SYMBOL(__scsi_iterate_devices);
1133
1134/**
1135 * starget_for_each_device - helper to walk all devices of a target
1136 * @starget: target whose devices we want to iterate over.
1137 * @data: Opaque passed to each function call.
1138 * @fn: Function to call on each device
1139 *
1140 * This traverses over each device of @starget. The devices have
1141 * a reference that must be released by scsi_host_put when breaking
1142 * out of the loop.
1143 */
1144void starget_for_each_device(struct scsi_target *starget, void *data,
1145 void (*fn)(struct scsi_device *, void *))
1146{
1147 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1148 struct scsi_device *sdev;
1149
1150 shost_for_each_device(sdev, shost) {
1151 if ((sdev->channel == starget->channel) &&
1152 (sdev->id == starget->id))
1153 fn(sdev, data);
1154 }
1155}
1156EXPORT_SYMBOL(starget_for_each_device);
1157
1158/**
1159 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
1160 * @starget: target whose devices we want to iterate over.
1161 * @data: parameter for callback @fn()
1162 * @fn: callback function that is invoked for each device
1163 *
1164 * This traverses over each device of @starget. It does _not_
1165 * take a reference on the scsi_device, so the whole loop must be
1166 * protected by shost->host_lock.
1167 *
1168 * Note: The only reason why drivers would want to use this is because
1169 * they need to access the device list in irq context. Otherwise you
1170 * really want to use starget_for_each_device instead.
1171 **/
1172void __starget_for_each_device(struct scsi_target *starget, void *data,
1173 void (*fn)(struct scsi_device *, void *))
1174{
1175 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1176 struct scsi_device *sdev;
1177
1178 __shost_for_each_device(sdev, shost) {
1179 if ((sdev->channel == starget->channel) &&
1180 (sdev->id == starget->id))
1181 fn(sdev, data);
1182 }
1183}
1184EXPORT_SYMBOL(__starget_for_each_device);
1185
1186/**
1187 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1188 * @starget: SCSI target pointer
1189 * @lun: SCSI Logical Unit Number
1190 *
1191 * Description: Looks up the scsi_device with the specified @lun for a given
1192 * @starget. The returned scsi_device does not have an additional
1193 * reference. You must hold the host's host_lock over this call and
1194 * any access to the returned scsi_device. A scsi_device in state
1195 * SDEV_DEL is skipped.
1196 *
1197 * Note: The only reason why drivers should use this is because
1198 * they need to access the device list in irq context. Otherwise you
1199 * really want to use scsi_device_lookup_by_target instead.
1200 **/
1201struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
1202 uint lun)
1203{
1204 struct scsi_device *sdev;
1205
1206 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
1207 if (sdev->sdev_state == SDEV_DEL)
1208 continue;
1209 if (sdev->lun ==lun)
1210 return sdev;
1211 }
1212
1213 return NULL;
1214}
1215EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1216
1217/**
1218 * scsi_device_lookup_by_target - find a device given the target
1219 * @starget: SCSI target pointer
1220 * @lun: SCSI Logical Unit Number
1221 *
1222 * Description: Looks up the scsi_device with the specified @lun for a given
1223 * @starget. The returned scsi_device has an additional reference that
1224 * needs to be released with scsi_device_put once you're done with it.
1225 **/
1226struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
1227 uint lun)
1228{
1229 struct scsi_device *sdev;
1230 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1231 unsigned long flags;
1232
1233 spin_lock_irqsave(shost->host_lock, flags);
1234 sdev = __scsi_device_lookup_by_target(starget, lun);
1235 if (sdev && scsi_device_get(sdev))
1236 sdev = NULL;
1237 spin_unlock_irqrestore(shost->host_lock, flags);
1238
1239 return sdev;
1240}
1241EXPORT_SYMBOL(scsi_device_lookup_by_target);
1242
1243/**
1244 * __scsi_device_lookup - find a device given the host (UNLOCKED)
1245 * @shost: SCSI host pointer
1246 * @channel: SCSI channel (zero if only one channel)
1247 * @id: SCSI target number (physical unit number)
1248 * @lun: SCSI Logical Unit Number
1249 *
1250 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1251 * for a given host. The returned scsi_device does not have an additional
1252 * reference. You must hold the host's host_lock over this call and any access
1253 * to the returned scsi_device.
1254 *
1255 * Note: The only reason why drivers would want to use this is because
1256 * they need to access the device list in irq context. Otherwise you
1257 * really want to use scsi_device_lookup instead.
1258 **/
1259struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
1260 uint channel, uint id, uint lun)
1261{
1262 struct scsi_device *sdev;
1263
1264 list_for_each_entry(sdev, &shost->__devices, siblings) {
1265 if (sdev->channel == channel && sdev->id == id &&
1266 sdev->lun ==lun)
1267 return sdev;
1268 }
1269
1270 return NULL;
1271}
1272EXPORT_SYMBOL(__scsi_device_lookup);
1273
1274/**
1275 * scsi_device_lookup - find a device given the host
1276 * @shost: SCSI host pointer
1277 * @channel: SCSI channel (zero if only one channel)
1278 * @id: SCSI target number (physical unit number)
1279 * @lun: SCSI Logical Unit Number
1280 *
1281 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1282 * for a given host. The returned scsi_device has an additional reference that
1283 * needs to be released with scsi_device_put once you're done with it.
1284 **/
1285struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1286 uint channel, uint id, uint lun)
1287{
1288 struct scsi_device *sdev;
1289 unsigned long flags;
1290
1291 spin_lock_irqsave(shost->host_lock, flags);
1292 sdev = __scsi_device_lookup(shost, channel, id, lun);
1293 if (sdev && scsi_device_get(sdev))
1294 sdev = NULL;
1295 spin_unlock_irqrestore(shost->host_lock, flags);
1296
1297 return sdev;
1298}
1299EXPORT_SYMBOL(scsi_device_lookup);
1300
1301MODULE_DESCRIPTION("SCSI core");
1302MODULE_LICENSE("GPL");
1303
1304module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1305MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1306
1307static int __init init_scsi(void)
1308{
1309 int error;
1310
1311 error = scsi_init_queue();
1312 if (error)
1313 return error;
1314 error = scsi_init_procfs();
1315 if (error)
1316 goto cleanup_queue;
1317 error = scsi_init_devinfo();
1318 if (error)
1319 goto cleanup_procfs;
1320 error = scsi_init_hosts();
1321 if (error)
1322 goto cleanup_devlist;
1323 error = scsi_init_sysctl();
1324 if (error)
1325 goto cleanup_hosts;
1326 error = scsi_sysfs_register();
1327 if (error)
1328 goto cleanup_sysctl;
1329
1330 scsi_netlink_init();
1331
1332 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1333 return 0;
1334
1335cleanup_sysctl:
1336 scsi_exit_sysctl();
1337cleanup_hosts:
1338 scsi_exit_hosts();
1339cleanup_devlist:
1340 scsi_exit_devinfo();
1341cleanup_procfs:
1342 scsi_exit_procfs();
1343cleanup_queue:
1344 scsi_exit_queue();
1345 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1346 -error);
1347 return error;
1348}
1349
1350static void __exit exit_scsi(void)
1351{
1352 scsi_netlink_exit();
1353 scsi_sysfs_unregister();
1354 scsi_exit_sysctl();
1355 scsi_exit_hosts();
1356 scsi_exit_devinfo();
1357 scsi_exit_procfs();
1358 scsi_exit_queue();
1359}
1360
1361subsys_initcall(init_scsi);
1362module_exit(exit_scsi);
1/*
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/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>
59
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>
68
69#include "scsi_priv.h"
70#include "scsi_logging.h"
71
72#define CREATE_TRACE_POINTS
73#include <trace/events/scsi.h>
74
75static void scsi_done(struct scsi_cmnd *cmd);
76
77/*
78 * Definitions and constants.
79 */
80
81/*
82 * Note - the initial logging level can be set here to log events at boot time.
83 * After the system is up, you may enable logging via the /proc interface.
84 */
85unsigned int scsi_logging_level;
86#if defined(CONFIG_SCSI_LOGGING)
87EXPORT_SYMBOL(scsi_logging_level);
88#endif
89
90/* sd, scsi core and power management need to coordinate flushing async actions */
91ASYNC_DOMAIN(scsi_sd_probe_domain);
92EXPORT_SYMBOL(scsi_sd_probe_domain);
93
94/*
95 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
96 * asynchronous system resume operations. It is marked 'exclusive' to avoid
97 * being included in the async_synchronize_full() that is invoked by
98 * dpm_resume()
99 */
100ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
101EXPORT_SYMBOL(scsi_sd_pm_domain);
102
103/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
104 * You may not alter any existing entry (although adding new ones is
105 * encouraged once assigned by ANSI/INCITS T10
106 */
107static const char *const scsi_device_types[] = {
108 "Direct-Access ",
109 "Sequential-Access",
110 "Printer ",
111 "Processor ",
112 "WORM ",
113 "CD-ROM ",
114 "Scanner ",
115 "Optical Device ",
116 "Medium Changer ",
117 "Communications ",
118 "ASC IT8 ",
119 "ASC IT8 ",
120 "RAID ",
121 "Enclosure ",
122 "Direct-Access-RBC",
123 "Optical card ",
124 "Bridge controller",
125 "Object storage ",
126 "Automation/Drive ",
127};
128
129/**
130 * scsi_device_type - Return 17 char string indicating device type.
131 * @type: type number to look up
132 */
133
134const char * scsi_device_type(unsigned type)
135{
136 if (type == 0x1e)
137 return "Well-known LUN ";
138 if (type == 0x1f)
139 return "No Device ";
140 if (type >= ARRAY_SIZE(scsi_device_types))
141 return "Unknown ";
142 return scsi_device_types[type];
143}
144
145EXPORT_SYMBOL(scsi_device_type);
146
147struct scsi_host_cmd_pool {
148 struct kmem_cache *cmd_slab;
149 struct kmem_cache *sense_slab;
150 unsigned int users;
151 char *cmd_name;
152 char *sense_name;
153 unsigned int slab_flags;
154 gfp_t gfp_mask;
155};
156
157static struct scsi_host_cmd_pool scsi_cmd_pool = {
158 .cmd_name = "scsi_cmd_cache",
159 .sense_name = "scsi_sense_cache",
160 .slab_flags = SLAB_HWCACHE_ALIGN,
161};
162
163static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
164 .cmd_name = "scsi_cmd_cache(DMA)",
165 .sense_name = "scsi_sense_cache(DMA)",
166 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
167 .gfp_mask = __GFP_DMA,
168};
169
170static DEFINE_MUTEX(host_cmd_pool_mutex);
171
172/**
173 * scsi_host_free_command - internal function to release a command
174 * @shost: host to free the command for
175 * @cmd: command to release
176 *
177 * the command must previously have been allocated by
178 * scsi_host_alloc_command.
179 */
180static void
181scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
182{
183 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
184
185 if (cmd->prot_sdb)
186 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
187 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
188 kmem_cache_free(pool->cmd_slab, cmd);
189}
190
191/**
192 * scsi_host_alloc_command - internal function to allocate command
193 * @shost: SCSI host whose pool to allocate from
194 * @gfp_mask: mask for the allocation
195 *
196 * Returns a fully allocated command with sense buffer and protection
197 * data buffer (where applicable) or NULL on failure
198 */
199static struct scsi_cmnd *
200scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
201{
202 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
203 struct scsi_cmnd *cmd;
204
205 cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
206 if (!cmd)
207 goto fail;
208
209 cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
210 gfp_mask | pool->gfp_mask);
211 if (!cmd->sense_buffer)
212 goto fail_free_cmd;
213
214 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
215 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
216 if (!cmd->prot_sdb)
217 goto fail_free_sense;
218 }
219
220 return cmd;
221
222fail_free_sense:
223 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
224fail_free_cmd:
225 kmem_cache_free(pool->cmd_slab, cmd);
226fail:
227 return NULL;
228}
229
230/**
231 * __scsi_get_command - Allocate a struct scsi_cmnd
232 * @shost: host to transmit command
233 * @gfp_mask: allocation mask
234 *
235 * Description: allocate a struct scsi_cmd from host's slab, recycling from the
236 * host's free_list if necessary.
237 */
238struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
239{
240 struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
241
242 if (unlikely(!cmd)) {
243 unsigned long flags;
244
245 spin_lock_irqsave(&shost->free_list_lock, flags);
246 if (likely(!list_empty(&shost->free_list))) {
247 cmd = list_entry(shost->free_list.next,
248 struct scsi_cmnd, list);
249 list_del_init(&cmd->list);
250 }
251 spin_unlock_irqrestore(&shost->free_list_lock, flags);
252
253 if (cmd) {
254 void *buf, *prot;
255
256 buf = cmd->sense_buffer;
257 prot = cmd->prot_sdb;
258
259 memset(cmd, 0, sizeof(*cmd));
260
261 cmd->sense_buffer = buf;
262 cmd->prot_sdb = prot;
263 }
264 }
265
266 return cmd;
267}
268EXPORT_SYMBOL_GPL(__scsi_get_command);
269
270/**
271 * scsi_get_command - Allocate and setup a scsi command block
272 * @dev: parent scsi device
273 * @gfp_mask: allocator flags
274 *
275 * Returns: The allocated scsi command structure.
276 */
277struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
278{
279 struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
280 unsigned long flags;
281
282 if (unlikely(cmd == NULL))
283 return NULL;
284
285 cmd->device = dev;
286 INIT_LIST_HEAD(&cmd->list);
287 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
288 spin_lock_irqsave(&dev->list_lock, flags);
289 list_add_tail(&cmd->list, &dev->cmd_list);
290 spin_unlock_irqrestore(&dev->list_lock, flags);
291 cmd->jiffies_at_alloc = jiffies;
292 return cmd;
293}
294EXPORT_SYMBOL(scsi_get_command);
295
296/**
297 * __scsi_put_command - Free a struct scsi_cmnd
298 * @shost: dev->host
299 * @cmd: Command to free
300 */
301void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
302{
303 unsigned long flags;
304
305 if (unlikely(list_empty(&shost->free_list))) {
306 spin_lock_irqsave(&shost->free_list_lock, flags);
307 if (list_empty(&shost->free_list)) {
308 list_add(&cmd->list, &shost->free_list);
309 cmd = NULL;
310 }
311 spin_unlock_irqrestore(&shost->free_list_lock, flags);
312 }
313
314 if (likely(cmd != NULL))
315 scsi_host_free_command(shost, cmd);
316}
317EXPORT_SYMBOL(__scsi_put_command);
318
319/**
320 * scsi_put_command - Free a scsi command block
321 * @cmd: command block to free
322 *
323 * Returns: Nothing.
324 *
325 * Notes: The command must not belong to any lists.
326 */
327void scsi_put_command(struct scsi_cmnd *cmd)
328{
329 unsigned long flags;
330
331 /* serious error if the command hasn't come from a device list */
332 spin_lock_irqsave(&cmd->device->list_lock, flags);
333 BUG_ON(list_empty(&cmd->list));
334 list_del_init(&cmd->list);
335 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
336
337 cancel_delayed_work(&cmd->abort_work);
338
339 __scsi_put_command(cmd->device->host, cmd);
340}
341EXPORT_SYMBOL(scsi_put_command);
342
343static struct scsi_host_cmd_pool *
344scsi_find_host_cmd_pool(struct Scsi_Host *shost)
345{
346 if (shost->hostt->cmd_size)
347 return shost->hostt->cmd_pool;
348 if (shost->unchecked_isa_dma)
349 return &scsi_cmd_dma_pool;
350 return &scsi_cmd_pool;
351}
352
353static void
354scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
355{
356 kfree(pool->sense_name);
357 kfree(pool->cmd_name);
358 kfree(pool);
359}
360
361static struct scsi_host_cmd_pool *
362scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
363{
364 struct scsi_host_template *hostt = shost->hostt;
365 struct scsi_host_cmd_pool *pool;
366
367 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
368 if (!pool)
369 return NULL;
370
371 pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
372 pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->name);
373 if (!pool->cmd_name || !pool->sense_name) {
374 scsi_free_host_cmd_pool(pool);
375 return NULL;
376 }
377
378 pool->slab_flags = SLAB_HWCACHE_ALIGN;
379 if (shost->unchecked_isa_dma) {
380 pool->slab_flags |= SLAB_CACHE_DMA;
381 pool->gfp_mask = __GFP_DMA;
382 }
383 return pool;
384}
385
386static struct scsi_host_cmd_pool *
387scsi_get_host_cmd_pool(struct Scsi_Host *shost)
388{
389 struct scsi_host_template *hostt = shost->hostt;
390 struct scsi_host_cmd_pool *retval = NULL, *pool;
391 size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
392
393 /*
394 * Select a command slab for this host and create it if not
395 * yet existent.
396 */
397 mutex_lock(&host_cmd_pool_mutex);
398 pool = scsi_find_host_cmd_pool(shost);
399 if (!pool) {
400 pool = scsi_alloc_host_cmd_pool(shost);
401 if (!pool)
402 goto out;
403 }
404
405 if (!pool->users) {
406 pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
407 pool->slab_flags, NULL);
408 if (!pool->cmd_slab)
409 goto out_free_pool;
410
411 pool->sense_slab = kmem_cache_create(pool->sense_name,
412 SCSI_SENSE_BUFFERSIZE, 0,
413 pool->slab_flags, NULL);
414 if (!pool->sense_slab)
415 goto out_free_slab;
416 }
417
418 pool->users++;
419 retval = pool;
420out:
421 mutex_unlock(&host_cmd_pool_mutex);
422 return retval;
423
424out_free_slab:
425 kmem_cache_destroy(pool->cmd_slab);
426out_free_pool:
427 if (hostt->cmd_size)
428 scsi_free_host_cmd_pool(pool);
429 goto out;
430}
431
432static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
433{
434 struct scsi_host_template *hostt = shost->hostt;
435 struct scsi_host_cmd_pool *pool;
436
437 mutex_lock(&host_cmd_pool_mutex);
438 pool = scsi_find_host_cmd_pool(shost);
439
440 /*
441 * This may happen if a driver has a mismatched get and put
442 * of the command pool; the driver should be implicated in
443 * the stack trace
444 */
445 BUG_ON(pool->users == 0);
446
447 if (!--pool->users) {
448 kmem_cache_destroy(pool->cmd_slab);
449 kmem_cache_destroy(pool->sense_slab);
450 if (hostt->cmd_size)
451 scsi_free_host_cmd_pool(pool);
452 }
453 mutex_unlock(&host_cmd_pool_mutex);
454}
455
456/**
457 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
458 * @shost: host to allocate the freelist for.
459 *
460 * Description: The command freelist protects against system-wide out of memory
461 * deadlock by preallocating one SCSI command structure for each host, so the
462 * system can always write to a swap file on a device associated with that host.
463 *
464 * Returns: Nothing.
465 */
466int scsi_setup_command_freelist(struct Scsi_Host *shost)
467{
468 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
469 struct scsi_cmnd *cmd;
470
471 spin_lock_init(&shost->free_list_lock);
472 INIT_LIST_HEAD(&shost->free_list);
473
474 shost->cmd_pool = scsi_get_host_cmd_pool(shost);
475 if (!shost->cmd_pool)
476 return -ENOMEM;
477
478 /*
479 * Get one backup command for this host.
480 */
481 cmd = scsi_host_alloc_command(shost, gfp_mask);
482 if (!cmd) {
483 scsi_put_host_cmd_pool(shost);
484 shost->cmd_pool = NULL;
485 return -ENOMEM;
486 }
487 list_add(&cmd->list, &shost->free_list);
488 return 0;
489}
490
491/**
492 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
493 * @shost: host whose freelist is going to be destroyed
494 */
495void scsi_destroy_command_freelist(struct Scsi_Host *shost)
496{
497 /*
498 * If cmd_pool is NULL the free list was not initialized, so
499 * do not attempt to release resources.
500 */
501 if (!shost->cmd_pool)
502 return;
503
504 while (!list_empty(&shost->free_list)) {
505 struct scsi_cmnd *cmd;
506
507 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
508 list_del_init(&cmd->list);
509 scsi_host_free_command(shost, cmd);
510 }
511 shost->cmd_pool = NULL;
512 scsi_put_host_cmd_pool(shost);
513}
514
515#ifdef CONFIG_SCSI_LOGGING
516void scsi_log_send(struct scsi_cmnd *cmd)
517{
518 unsigned int level;
519
520 /*
521 * If ML QUEUE log level is greater than or equal to:
522 *
523 * 1: nothing (match completion)
524 *
525 * 2: log opcode + command of all commands
526 *
527 * 3: same as 2 plus dump cmd address
528 *
529 * 4: same as 3 plus dump extra junk
530 */
531 if (unlikely(scsi_logging_level)) {
532 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
533 SCSI_LOG_MLQUEUE_BITS);
534 if (level > 1) {
535 scmd_printk(KERN_INFO, cmd, "Send: ");
536 if (level > 2)
537 printk("0x%p ", cmd);
538 printk("\n");
539 scsi_print_command(cmd);
540 if (level > 3) {
541 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
542 " queuecommand 0x%p\n",
543 scsi_sglist(cmd), scsi_bufflen(cmd),
544 cmd->device->host->hostt->queuecommand);
545
546 }
547 }
548 }
549}
550
551void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
552{
553 unsigned int level;
554
555 /*
556 * If ML COMPLETE log level is greater than or equal to:
557 *
558 * 1: log disposition, result, opcode + command, and conditionally
559 * sense data for failures or non SUCCESS dispositions.
560 *
561 * 2: same as 1 but for all command completions.
562 *
563 * 3: same as 2 plus dump cmd address
564 *
565 * 4: same as 3 plus dump extra junk
566 */
567 if (unlikely(scsi_logging_level)) {
568 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
569 SCSI_LOG_MLCOMPLETE_BITS);
570 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
571 (level > 1)) {
572 scmd_printk(KERN_INFO, cmd, "Done: ");
573 if (level > 2)
574 printk("0x%p ", cmd);
575 /*
576 * Dump truncated values, so we usually fit within
577 * 80 chars.
578 */
579 switch (disposition) {
580 case SUCCESS:
581 printk("SUCCESS\n");
582 break;
583 case NEEDS_RETRY:
584 printk("RETRY\n");
585 break;
586 case ADD_TO_MLQUEUE:
587 printk("MLQUEUE\n");
588 break;
589 case FAILED:
590 printk("FAILED\n");
591 break;
592 case TIMEOUT_ERROR:
593 /*
594 * If called via scsi_times_out.
595 */
596 printk("TIMEOUT\n");
597 break;
598 default:
599 printk("UNKNOWN\n");
600 }
601 scsi_print_result(cmd);
602 scsi_print_command(cmd);
603 if (status_byte(cmd->result) & CHECK_CONDITION)
604 scsi_print_sense("", cmd);
605 if (level > 3)
606 scmd_printk(KERN_INFO, cmd,
607 "scsi host busy %d failed %d\n",
608 cmd->device->host->host_busy,
609 cmd->device->host->host_failed);
610 }
611 }
612}
613#endif
614
615/**
616 * scsi_cmd_get_serial - Assign a serial number to a command
617 * @host: the scsi host
618 * @cmd: command to assign serial number to
619 *
620 * Description: a serial number identifies a request for error recovery
621 * and debugging purposes. Protected by the Host_Lock of host.
622 */
623void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
624{
625 cmd->serial_number = host->cmd_serial_number++;
626 if (cmd->serial_number == 0)
627 cmd->serial_number = host->cmd_serial_number++;
628}
629EXPORT_SYMBOL(scsi_cmd_get_serial);
630
631/**
632 * scsi_dispatch_command - Dispatch a command to the low-level driver.
633 * @cmd: command block we are dispatching.
634 *
635 * Return: nonzero return request was rejected and device's queue needs to be
636 * plugged.
637 */
638int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
639{
640 struct Scsi_Host *host = cmd->device->host;
641 int rtn = 0;
642
643 atomic_inc(&cmd->device->iorequest_cnt);
644
645 /* check if the device is still usable */
646 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
647 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
648 * returns an immediate error upwards, and signals
649 * that the device is no longer present */
650 cmd->result = DID_NO_CONNECT << 16;
651 scsi_done(cmd);
652 /* return 0 (because the command has been processed) */
653 goto out;
654 }
655
656 /* Check to see if the scsi lld made this device blocked. */
657 if (unlikely(scsi_device_blocked(cmd->device))) {
658 /*
659 * in blocked state, the command is just put back on
660 * the device queue. The suspend state has already
661 * blocked the queue so future requests should not
662 * occur until the device transitions out of the
663 * suspend state.
664 */
665
666 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
667
668 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
669
670 /*
671 * NOTE: rtn is still zero here because we don't need the
672 * queue to be plugged on return (it's already stopped)
673 */
674 goto out;
675 }
676
677 /*
678 * If SCSI-2 or lower, store the LUN value in cmnd.
679 */
680 if (cmd->device->scsi_level <= SCSI_2 &&
681 cmd->device->scsi_level != SCSI_UNKNOWN) {
682 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
683 (cmd->device->lun << 5 & 0xe0);
684 }
685
686 scsi_log_send(cmd);
687
688 /*
689 * Before we queue this command, check if the command
690 * length exceeds what the host adapter can handle.
691 */
692 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
693 SCSI_LOG_MLQUEUE(3,
694 printk("queuecommand : command too long. "
695 "cdb_size=%d host->max_cmd_len=%d\n",
696 cmd->cmd_len, cmd->device->host->max_cmd_len));
697 cmd->result = (DID_ABORT << 16);
698
699 scsi_done(cmd);
700 goto out;
701 }
702
703 if (unlikely(host->shost_state == SHOST_DEL)) {
704 cmd->result = (DID_NO_CONNECT << 16);
705 scsi_done(cmd);
706 } else {
707 trace_scsi_dispatch_cmd_start(cmd);
708 cmd->scsi_done = scsi_done;
709 rtn = host->hostt->queuecommand(host, cmd);
710 }
711
712 if (rtn) {
713 trace_scsi_dispatch_cmd_error(cmd, rtn);
714 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
715 rtn != SCSI_MLQUEUE_TARGET_BUSY)
716 rtn = SCSI_MLQUEUE_HOST_BUSY;
717
718 scsi_queue_insert(cmd, rtn);
719
720 SCSI_LOG_MLQUEUE(3,
721 printk("queuecommand : request rejected\n"));
722 }
723
724 out:
725 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
726 return rtn;
727}
728
729/**
730 * scsi_done - Invoke completion on finished SCSI command.
731 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
732 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
733 *
734 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
735 * which regains ownership of the SCSI command (de facto) from a LLDD, and
736 * calls blk_complete_request() for further processing.
737 *
738 * This function is interrupt context safe.
739 */
740static void scsi_done(struct scsi_cmnd *cmd)
741{
742 trace_scsi_dispatch_cmd_done(cmd);
743 blk_complete_request(cmd->request);
744}
745
746/**
747 * scsi_finish_command - cleanup and pass command back to upper layer
748 * @cmd: the command
749 *
750 * Description: Pass command off to upper layer for finishing of I/O
751 * request, waking processes that are waiting on results,
752 * etc.
753 */
754void scsi_finish_command(struct scsi_cmnd *cmd)
755{
756 struct scsi_device *sdev = cmd->device;
757 struct scsi_target *starget = scsi_target(sdev);
758 struct Scsi_Host *shost = sdev->host;
759 struct scsi_driver *drv;
760 unsigned int good_bytes;
761
762 scsi_device_unbusy(sdev);
763
764 /*
765 * Clear the flags which say that the device/host is no longer
766 * capable of accepting new commands. These are set in scsi_queue.c
767 * for both the queue full condition on a device, and for a
768 * host full condition on the host.
769 *
770 * XXX(hch): What about locking?
771 */
772 shost->host_blocked = 0;
773 starget->target_blocked = 0;
774 sdev->device_blocked = 0;
775
776 /*
777 * If we have valid sense information, then some kind of recovery
778 * must have taken place. Make a note of this.
779 */
780 if (SCSI_SENSE_VALID(cmd))
781 cmd->result |= (DRIVER_SENSE << 24);
782
783 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
784 "Notifying upper driver of completion "
785 "(result %x)\n", cmd->result));
786
787 good_bytes = scsi_bufflen(cmd);
788 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
789 int old_good_bytes = good_bytes;
790 drv = scsi_cmd_to_driver(cmd);
791 if (drv->done)
792 good_bytes = drv->done(cmd);
793 /*
794 * USB may not give sense identifying bad sector and
795 * simply return a residue instead, so subtract off the
796 * residue if drv->done() error processing indicates no
797 * change to the completion length.
798 */
799 if (good_bytes == old_good_bytes)
800 good_bytes -= scsi_get_resid(cmd);
801 }
802 scsi_io_completion(cmd, good_bytes);
803}
804EXPORT_SYMBOL(scsi_finish_command);
805
806/**
807 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
808 * @sdev: SCSI Device in question
809 * @tagged: Do we use tagged queueing (non-0) or do we treat
810 * this device as an untagged device (0)
811 * @tags: Number of tags allowed if tagged queueing enabled,
812 * or number of commands the low level driver can
813 * queue up in non-tagged mode (as per cmd_per_lun).
814 *
815 * Returns: Nothing
816 *
817 * Lock Status: None held on entry
818 *
819 * Notes: Low level drivers may call this at any time and we will do
820 * the right thing depending on whether or not the device is
821 * currently active and whether or not it even has the
822 * command blocks built yet.
823 */
824void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
825{
826 unsigned long flags;
827
828 /*
829 * refuse to set tagged depth to an unworkable size
830 */
831 if (tags <= 0)
832 return;
833
834 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
835
836 /*
837 * Check to see if the queue is managed by the block layer.
838 * If it is, and we fail to adjust the depth, exit.
839 *
840 * Do not resize the tag map if it is a host wide share bqt,
841 * because the size should be the hosts's can_queue. If there
842 * is more IO than the LLD's can_queue (so there are not enuogh
843 * tags) request_fn's host queue ready check will handle it.
844 */
845 if (!sdev->host->bqt) {
846 if (blk_queue_tagged(sdev->request_queue) &&
847 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
848 goto out;
849 }
850
851 sdev->queue_depth = tags;
852 switch (tagged) {
853 case MSG_ORDERED_TAG:
854 sdev->ordered_tags = 1;
855 sdev->simple_tags = 1;
856 break;
857 case MSG_SIMPLE_TAG:
858 sdev->ordered_tags = 0;
859 sdev->simple_tags = 1;
860 break;
861 default:
862 sdev_printk(KERN_WARNING, sdev,
863 "scsi_adjust_queue_depth, bad queue type, "
864 "disabled\n");
865 case 0:
866 sdev->ordered_tags = sdev->simple_tags = 0;
867 sdev->queue_depth = tags;
868 break;
869 }
870 out:
871 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
872}
873EXPORT_SYMBOL(scsi_adjust_queue_depth);
874
875/**
876 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
877 * @sdev: SCSI Device in question
878 * @depth: Current number of outstanding SCSI commands on this device,
879 * not counting the one returned as QUEUE_FULL.
880 *
881 * Description: This function will track successive QUEUE_FULL events on a
882 * specific SCSI device to determine if and when there is a
883 * need to adjust the queue depth on the device.
884 *
885 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
886 * -1 - Drop back to untagged operation using host->cmd_per_lun
887 * as the untagged command depth
888 *
889 * Lock Status: None held on entry
890 *
891 * Notes: Low level drivers may call this at any time and we will do
892 * "The Right Thing." We are interrupt context safe.
893 */
894int scsi_track_queue_full(struct scsi_device *sdev, int depth)
895{
896
897 /*
898 * Don't let QUEUE_FULLs on the same
899 * jiffies count, they could all be from
900 * same event.
901 */
902 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
903 return 0;
904
905 sdev->last_queue_full_time = jiffies;
906 if (sdev->last_queue_full_depth != depth) {
907 sdev->last_queue_full_count = 1;
908 sdev->last_queue_full_depth = depth;
909 } else {
910 sdev->last_queue_full_count++;
911 }
912
913 if (sdev->last_queue_full_count <= 10)
914 return 0;
915 if (sdev->last_queue_full_depth < 8) {
916 /* Drop back to untagged */
917 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
918 return -1;
919 }
920
921 if (sdev->ordered_tags)
922 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
923 else
924 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
925 return depth;
926}
927EXPORT_SYMBOL(scsi_track_queue_full);
928
929/**
930 * scsi_vpd_inquiry - Request a device provide us with a VPD page
931 * @sdev: The device to ask
932 * @buffer: Where to put the result
933 * @page: Which Vital Product Data to return
934 * @len: The length of the buffer
935 *
936 * This is an internal helper function. You probably want to use
937 * scsi_get_vpd_page instead.
938 *
939 * Returns size of the vpd page on success or a negative error number.
940 */
941static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
942 u8 page, unsigned len)
943{
944 int result;
945 unsigned char cmd[16];
946
947 if (len < 4)
948 return -EINVAL;
949
950 cmd[0] = INQUIRY;
951 cmd[1] = 1; /* EVPD */
952 cmd[2] = page;
953 cmd[3] = len >> 8;
954 cmd[4] = len & 0xff;
955 cmd[5] = 0; /* Control byte */
956
957 /*
958 * I'm not convinced we need to try quite this hard to get VPD, but
959 * all the existing users tried this hard.
960 */
961 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
962 len, NULL, 30 * HZ, 3, NULL);
963 if (result)
964 return -EIO;
965
966 /* Sanity check that we got the page back that we asked for */
967 if (buffer[1] != page)
968 return -EIO;
969
970 return get_unaligned_be16(&buffer[2]) + 4;
971}
972
973/**
974 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
975 * @sdev: The device to ask
976 * @page: Which Vital Product Data to return
977 * @buf: where to store the VPD
978 * @buf_len: number of bytes in the VPD buffer area
979 *
980 * SCSI devices may optionally supply Vital Product Data. Each 'page'
981 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
982 * If the device supports this VPD page, this routine returns a pointer
983 * to a buffer containing the data from that page. The caller is
984 * responsible for calling kfree() on this pointer when it is no longer
985 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
986 */
987int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
988 int buf_len)
989{
990 int i, result;
991
992 if (sdev->skip_vpd_pages)
993 goto fail;
994
995 /* Ask for all the pages supported by this device */
996 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
997 if (result < 4)
998 goto fail;
999
1000 /* If the user actually wanted this page, we can skip the rest */
1001 if (page == 0)
1002 return 0;
1003
1004 for (i = 4; i < min(result, buf_len); i++)
1005 if (buf[i] == page)
1006 goto found;
1007
1008 if (i < result && i >= buf_len)
1009 /* ran off the end of the buffer, give us benefit of doubt */
1010 goto found;
1011 /* The device claims it doesn't support the requested page */
1012 goto fail;
1013
1014 found:
1015 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
1016 if (result < 0)
1017 goto fail;
1018
1019 return 0;
1020
1021 fail:
1022 return -EINVAL;
1023}
1024EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
1025
1026/**
1027 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
1028 * @sdev: The device to ask
1029 *
1030 * Attach the 'Device Identification' VPD page (0x83) and the
1031 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
1032 * structure. This information can be used to identify the device
1033 * uniquely.
1034 */
1035void scsi_attach_vpd(struct scsi_device *sdev)
1036{
1037 int result, i;
1038 int vpd_len = SCSI_VPD_PG_LEN;
1039 int pg80_supported = 0;
1040 int pg83_supported = 0;
1041 unsigned char *vpd_buf;
1042
1043 if (sdev->skip_vpd_pages)
1044 return;
1045retry_pg0:
1046 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1047 if (!vpd_buf)
1048 return;
1049
1050 /* Ask for all the pages supported by this device */
1051 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
1052 if (result < 0) {
1053 kfree(vpd_buf);
1054 return;
1055 }
1056 if (result > vpd_len) {
1057 vpd_len = result;
1058 kfree(vpd_buf);
1059 goto retry_pg0;
1060 }
1061
1062 for (i = 4; i < result; i++) {
1063 if (vpd_buf[i] == 0x80)
1064 pg80_supported = 1;
1065 if (vpd_buf[i] == 0x83)
1066 pg83_supported = 1;
1067 }
1068 kfree(vpd_buf);
1069 vpd_len = SCSI_VPD_PG_LEN;
1070
1071 if (pg80_supported) {
1072retry_pg80:
1073 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1074 if (!vpd_buf)
1075 return;
1076
1077 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
1078 if (result < 0) {
1079 kfree(vpd_buf);
1080 return;
1081 }
1082 if (result > vpd_len) {
1083 vpd_len = result;
1084 kfree(vpd_buf);
1085 goto retry_pg80;
1086 }
1087 sdev->vpd_pg80_len = result;
1088 sdev->vpd_pg80 = vpd_buf;
1089 vpd_len = SCSI_VPD_PG_LEN;
1090 }
1091
1092 if (pg83_supported) {
1093retry_pg83:
1094 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1095 if (!vpd_buf)
1096 return;
1097
1098 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
1099 if (result < 0) {
1100 kfree(vpd_buf);
1101 return;
1102 }
1103 if (result > vpd_len) {
1104 vpd_len = result;
1105 kfree(vpd_buf);
1106 goto retry_pg83;
1107 }
1108 sdev->vpd_pg83_len = result;
1109 sdev->vpd_pg83 = vpd_buf;
1110 }
1111}
1112
1113/**
1114 * scsi_report_opcode - Find out if a given command opcode is supported
1115 * @sdev: scsi device to query
1116 * @buffer: scratch buffer (must be at least 20 bytes long)
1117 * @len: length of buffer
1118 * @opcode: opcode for command to look up
1119 *
1120 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
1121 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
1122 * unsupported and 1 if the device claims to support the command.
1123 */
1124int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
1125 unsigned int len, unsigned char opcode)
1126{
1127 unsigned char cmd[16];
1128 struct scsi_sense_hdr sshdr;
1129 int result;
1130
1131 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
1132 return -EINVAL;
1133
1134 memset(cmd, 0, 16);
1135 cmd[0] = MAINTENANCE_IN;
1136 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
1137 cmd[2] = 1; /* One command format */
1138 cmd[3] = opcode;
1139 put_unaligned_be32(len, &cmd[6]);
1140 memset(buffer, 0, len);
1141
1142 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
1143 &sshdr, 30 * HZ, 3, NULL);
1144
1145 if (result && scsi_sense_valid(&sshdr) &&
1146 sshdr.sense_key == ILLEGAL_REQUEST &&
1147 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
1148 return -EINVAL;
1149
1150 if ((buffer[1] & 3) == 3) /* Command supported */
1151 return 1;
1152
1153 return 0;
1154}
1155EXPORT_SYMBOL(scsi_report_opcode);
1156
1157/**
1158 * scsi_device_get - get an additional reference to a scsi_device
1159 * @sdev: device to get a reference to
1160 *
1161 * Description: Gets a reference to the scsi_device and increments the use count
1162 * of the underlying LLDD module. You must hold host_lock of the
1163 * parent Scsi_Host or already have a reference when calling this.
1164 */
1165int scsi_device_get(struct scsi_device *sdev)
1166{
1167 if (sdev->sdev_state == SDEV_DEL)
1168 return -ENXIO;
1169 if (!get_device(&sdev->sdev_gendev))
1170 return -ENXIO;
1171 /* We can fail this if we're doing SCSI operations
1172 * from module exit (like cache flush) */
1173 try_module_get(sdev->host->hostt->module);
1174
1175 return 0;
1176}
1177EXPORT_SYMBOL(scsi_device_get);
1178
1179/**
1180 * scsi_device_put - release a reference to a scsi_device
1181 * @sdev: device to release a reference on.
1182 *
1183 * Description: Release a reference to the scsi_device and decrements the use
1184 * count of the underlying LLDD module. The device is freed once the last
1185 * user vanishes.
1186 */
1187void scsi_device_put(struct scsi_device *sdev)
1188{
1189#ifdef CONFIG_MODULE_UNLOAD
1190 struct module *module = sdev->host->hostt->module;
1191
1192 /* The module refcount will be zero if scsi_device_get()
1193 * was called from a module removal routine */
1194 if (module && module_refcount(module) != 0)
1195 module_put(module);
1196#endif
1197 put_device(&sdev->sdev_gendev);
1198}
1199EXPORT_SYMBOL(scsi_device_put);
1200
1201/* helper for shost_for_each_device, see that for documentation */
1202struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1203 struct scsi_device *prev)
1204{
1205 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1206 struct scsi_device *next = NULL;
1207 unsigned long flags;
1208
1209 spin_lock_irqsave(shost->host_lock, flags);
1210 while (list->next != &shost->__devices) {
1211 next = list_entry(list->next, struct scsi_device, siblings);
1212 /* skip devices that we can't get a reference to */
1213 if (!scsi_device_get(next))
1214 break;
1215 next = NULL;
1216 list = list->next;
1217 }
1218 spin_unlock_irqrestore(shost->host_lock, flags);
1219
1220 if (prev)
1221 scsi_device_put(prev);
1222 return next;
1223}
1224EXPORT_SYMBOL(__scsi_iterate_devices);
1225
1226/**
1227 * starget_for_each_device - helper to walk all devices of a target
1228 * @starget: target whose devices we want to iterate over.
1229 * @data: Opaque passed to each function call.
1230 * @fn: Function to call on each device
1231 *
1232 * This traverses over each device of @starget. The devices have
1233 * a reference that must be released by scsi_host_put when breaking
1234 * out of the loop.
1235 */
1236void starget_for_each_device(struct scsi_target *starget, void *data,
1237 void (*fn)(struct scsi_device *, void *))
1238{
1239 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1240 struct scsi_device *sdev;
1241
1242 shost_for_each_device(sdev, shost) {
1243 if ((sdev->channel == starget->channel) &&
1244 (sdev->id == starget->id))
1245 fn(sdev, data);
1246 }
1247}
1248EXPORT_SYMBOL(starget_for_each_device);
1249
1250/**
1251 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
1252 * @starget: target whose devices we want to iterate over.
1253 * @data: parameter for callback @fn()
1254 * @fn: callback function that is invoked for each device
1255 *
1256 * This traverses over each device of @starget. It does _not_
1257 * take a reference on the scsi_device, so the whole loop must be
1258 * protected by shost->host_lock.
1259 *
1260 * Note: The only reason why drivers would want to use this is because
1261 * they need to access the device list in irq context. Otherwise you
1262 * really want to use starget_for_each_device instead.
1263 **/
1264void __starget_for_each_device(struct scsi_target *starget, void *data,
1265 void (*fn)(struct scsi_device *, void *))
1266{
1267 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1268 struct scsi_device *sdev;
1269
1270 __shost_for_each_device(sdev, shost) {
1271 if ((sdev->channel == starget->channel) &&
1272 (sdev->id == starget->id))
1273 fn(sdev, data);
1274 }
1275}
1276EXPORT_SYMBOL(__starget_for_each_device);
1277
1278/**
1279 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1280 * @starget: SCSI target pointer
1281 * @lun: SCSI Logical Unit Number
1282 *
1283 * Description: Looks up the scsi_device with the specified @lun for a given
1284 * @starget. The returned scsi_device does not have an additional
1285 * reference. You must hold the host's host_lock over this call and
1286 * any access to the returned scsi_device. A scsi_device in state
1287 * SDEV_DEL is skipped.
1288 *
1289 * Note: The only reason why drivers should use this is because
1290 * they need to access the device list in irq context. Otherwise you
1291 * really want to use scsi_device_lookup_by_target instead.
1292 **/
1293struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
1294 uint lun)
1295{
1296 struct scsi_device *sdev;
1297
1298 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
1299 if (sdev->sdev_state == SDEV_DEL)
1300 continue;
1301 if (sdev->lun ==lun)
1302 return sdev;
1303 }
1304
1305 return NULL;
1306}
1307EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1308
1309/**
1310 * scsi_device_lookup_by_target - find a device given the target
1311 * @starget: SCSI target pointer
1312 * @lun: SCSI Logical Unit Number
1313 *
1314 * Description: Looks up the scsi_device with the specified @lun for a given
1315 * @starget. The returned scsi_device has an additional reference that
1316 * needs to be released with scsi_device_put once you're done with it.
1317 **/
1318struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
1319 uint lun)
1320{
1321 struct scsi_device *sdev;
1322 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1323 unsigned long flags;
1324
1325 spin_lock_irqsave(shost->host_lock, flags);
1326 sdev = __scsi_device_lookup_by_target(starget, lun);
1327 if (sdev && scsi_device_get(sdev))
1328 sdev = NULL;
1329 spin_unlock_irqrestore(shost->host_lock, flags);
1330
1331 return sdev;
1332}
1333EXPORT_SYMBOL(scsi_device_lookup_by_target);
1334
1335/**
1336 * __scsi_device_lookup - find a device given the host (UNLOCKED)
1337 * @shost: SCSI host pointer
1338 * @channel: SCSI channel (zero if only one channel)
1339 * @id: SCSI target number (physical unit number)
1340 * @lun: SCSI Logical Unit Number
1341 *
1342 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1343 * for a given host. The returned scsi_device does not have an additional
1344 * reference. You must hold the host's host_lock over this call and any access
1345 * to the returned scsi_device.
1346 *
1347 * Note: The only reason why drivers would want to use this is because
1348 * they need to access the device list in irq context. Otherwise you
1349 * really want to use scsi_device_lookup instead.
1350 **/
1351struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
1352 uint channel, uint id, uint lun)
1353{
1354 struct scsi_device *sdev;
1355
1356 list_for_each_entry(sdev, &shost->__devices, siblings) {
1357 if (sdev->channel == channel && sdev->id == id &&
1358 sdev->lun ==lun)
1359 return sdev;
1360 }
1361
1362 return NULL;
1363}
1364EXPORT_SYMBOL(__scsi_device_lookup);
1365
1366/**
1367 * scsi_device_lookup - find a device given the host
1368 * @shost: SCSI host pointer
1369 * @channel: SCSI channel (zero if only one channel)
1370 * @id: SCSI target number (physical unit number)
1371 * @lun: SCSI Logical Unit Number
1372 *
1373 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1374 * for a given host. The returned scsi_device has an additional reference that
1375 * needs to be released with scsi_device_put once you're done with it.
1376 **/
1377struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1378 uint channel, uint id, uint lun)
1379{
1380 struct scsi_device *sdev;
1381 unsigned long flags;
1382
1383 spin_lock_irqsave(shost->host_lock, flags);
1384 sdev = __scsi_device_lookup(shost, channel, id, lun);
1385 if (sdev && scsi_device_get(sdev))
1386 sdev = NULL;
1387 spin_unlock_irqrestore(shost->host_lock, flags);
1388
1389 return sdev;
1390}
1391EXPORT_SYMBOL(scsi_device_lookup);
1392
1393MODULE_DESCRIPTION("SCSI core");
1394MODULE_LICENSE("GPL");
1395
1396module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1397MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1398
1399static int __init init_scsi(void)
1400{
1401 int error;
1402
1403 error = scsi_init_queue();
1404 if (error)
1405 return error;
1406 error = scsi_init_procfs();
1407 if (error)
1408 goto cleanup_queue;
1409 error = scsi_init_devinfo();
1410 if (error)
1411 goto cleanup_procfs;
1412 error = scsi_init_hosts();
1413 if (error)
1414 goto cleanup_devlist;
1415 error = scsi_init_sysctl();
1416 if (error)
1417 goto cleanup_hosts;
1418 error = scsi_sysfs_register();
1419 if (error)
1420 goto cleanup_sysctl;
1421
1422 scsi_netlink_init();
1423
1424 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1425 return 0;
1426
1427cleanup_sysctl:
1428 scsi_exit_sysctl();
1429cleanup_hosts:
1430 scsi_exit_hosts();
1431cleanup_devlist:
1432 scsi_exit_devinfo();
1433cleanup_procfs:
1434 scsi_exit_procfs();
1435cleanup_queue:
1436 scsi_exit_queue();
1437 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1438 -error);
1439 return error;
1440}
1441
1442static void __exit exit_scsi(void)
1443{
1444 scsi_netlink_exit();
1445 scsi_sysfs_unregister();
1446 scsi_exit_sysctl();
1447 scsi_exit_hosts();
1448 scsi_exit_devinfo();
1449 scsi_exit_procfs();
1450 scsi_exit_queue();
1451 async_unregister_domain(&scsi_sd_probe_domain);
1452}
1453
1454subsys_initcall(init_scsi);
1455module_exit(exit_scsi);