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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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#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>
Arjan van de Ven0b950672006-01-11 13:16:10 +010056#include <linux/mutex.h>
Dan Williams2955b472012-07-09 19:33:25 -070057#include <linux/async.h>
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -040058#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#include <scsi/scsi.h>
61#include <scsi/scsi_cmnd.h>
62#include <scsi/scsi_dbg.h>
63#include <scsi/scsi_device.h>
Linus Torvalds7b3d9542008-01-06 10:17:12 -080064#include <scsi/scsi_driver.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#include <scsi/scsi_eh.h>
66#include <scsi/scsi_host.h>
67#include <scsi/scsi_tcq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69#include "scsi_priv.h"
70#include "scsi_logging.h"
71
Kei Tokunagabf816232010-04-01 20:41:40 +090072#define CREATE_TRACE_POINTS
73#include <trace/events/scsi.h>
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075/*
76 * Definitions and constants.
77 */
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 * Note - the initial logging level can be set here to log events at boot time.
81 * After the system is up, you may enable logging via the /proc interface.
82 */
83unsigned int scsi_logging_level;
84#if defined(CONFIG_SCSI_LOGGING)
85EXPORT_SYMBOL(scsi_logging_level);
86#endif
87
James Bottomleyea80dad2012-06-06 14:54:13 +090088/* sd, scsi core and power management need to coordinate flushing async actions */
Dan Williams2955b472012-07-09 19:33:25 -070089ASYNC_DOMAIN(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070090EXPORT_SYMBOL(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070091
Dan Williams3c31b522014-04-10 15:30:35 -070092/*
93 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
94 * asynchronous system resume operations. It is marked 'exclusive' to avoid
95 * being included in the async_synchronize_full() that is invoked by
96 * dpm_resume()
97 */
98ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
99EXPORT_SYMBOL(scsi_sd_pm_domain);
100
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600101/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
102 * You may not alter any existing entry (although adding new ones is
103 * encouraged once assigned by ANSI/INCITS T10
104 */
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600105static const char *const scsi_device_types[] = {
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600106 "Direct-Access ",
107 "Sequential-Access",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 "Printer ",
109 "Processor ",
110 "WORM ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600111 "CD-ROM ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 "Scanner ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600113 "Optical Device ",
114 "Medium Changer ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 "Communications ",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600116 "ASC IT8 ",
117 "ASC IT8 ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 "RAID ",
119 "Enclosure ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600120 "Direct-Access-RBC",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600121 "Optical card ",
122 "Bridge controller",
123 "Object storage ",
124 "Automation/Drive ",
Christoph Hellwigc6e4f192014-07-18 16:50:39 +0200125 "Security Manager ",
126 "Direct-Access-ZBC",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127};
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600128
Rob Landleyeb448202007-11-03 13:30:39 -0500129/**
130 * scsi_device_type - Return 17 char string indicating device type.
131 * @type: type number to look up
132 */
133
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600134const char * scsi_device_type(unsigned type)
135{
136 if (type == 0x1e)
137 return "Well-known LUN ";
138 if (type == 0x1f)
139 return "No Device ";
Eric Sesterhenn80c6e3c2006-09-26 13:22:13 +0200140 if (type >= ARRAY_SIZE(scsi_device_types))
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600141 return "Unknown ";
142 return scsi_device_types[type];
143}
144
145EXPORT_SYMBOL(scsi_device_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147struct scsi_host_cmd_pool {
James Bottomley5b7f1682008-01-20 09:28:24 -0600148 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155};
156
157static struct scsi_host_cmd_pool scsi_cmd_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600158 .cmd_name = "scsi_cmd_cache",
159 .sense_name = "scsi_sense_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 .slab_flags = SLAB_HWCACHE_ALIGN,
161};
162
163static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600164 .cmd_name = "scsi_cmd_cache(DMA)",
165 .sense_name = "scsi_sense_cache(DMA)",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
167 .gfp_mask = __GFP_DMA,
168};
169
Arjan van de Ven0b950672006-01-11 13:16:10 +0100170static DEFINE_MUTEX(host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Rob Landleyeb448202007-11-03 13:30:39 -0500172/**
Christoph Hellwig7c283342014-02-20 14:21:00 -0800173 * scsi_host_free_command - internal function to release a command
174 * @shost: host to free the command for
James Bottomleye507e302008-03-13 11:16:33 -0500175 * @cmd: command to release
176 *
177 * the command must previously have been allocated by
Christoph Hellwig7c283342014-02-20 14:21:00 -0800178 * scsi_host_alloc_command.
James Bottomleye507e302008-03-13 11:16:33 -0500179 */
180static void
Christoph Hellwig7c283342014-02-20 14:21:00 -0800181scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
James Bottomleye507e302008-03-13 11:16:33 -0500182{
Christoph Hellwig7c283342014-02-20 14:21:00 -0800183 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
184
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400185 if (cmd->prot_sdb)
186 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
James Bottomleye507e302008-03-13 11:16:33 -0500187 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
188 kmem_cache_free(pool->cmd_slab, cmd);
189}
190
191/**
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400192 * 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{
Christoph Hellwig7c283342014-02-20 14:21:00 -0800202 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400203 struct scsi_cmnd *cmd;
204
Christoph Hellwig7c283342014-02-20 14:21:00 -0800205 cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400206 if (!cmd)
Christoph Hellwig7c283342014-02-20 14:21:00 -0800207 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;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400213
214 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
215 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
Christoph Hellwig7c283342014-02-20 14:21:00 -0800216 if (!cmd->prot_sdb)
217 goto fail_free_sense;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400218 }
219
220 return cmd;
Christoph Hellwig7c283342014-02-20 14:21:00 -0800221
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;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400228}
229
230/**
Rob Landleyeb448202007-11-03 13:30:39 -0500231 * __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 */
Christoph Hellwigf1bea552014-04-15 12:26:54 +0200238static struct scsi_cmnd *
239__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400241 struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
Hugh Dickins164fc5d2008-04-06 23:56:57 +0100242
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 if (unlikely(!cmd)) {
244 unsigned long flags;
245
246 spin_lock_irqsave(&shost->free_list_lock, flags);
247 if (likely(!list_empty(&shost->free_list))) {
248 cmd = list_entry(shost->free_list.next,
249 struct scsi_cmnd, list);
250 list_del_init(&cmd->list);
251 }
252 spin_unlock_irqrestore(&shost->free_list_lock, flags);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900253
254 if (cmd) {
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400255 void *buf, *prot;
256
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900257 buf = cmd->sense_buffer;
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400258 prot = cmd->prot_sdb;
259
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900260 memset(cmd, 0, sizeof(*cmd));
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400261
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900262 cmd->sense_buffer = buf;
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400263 cmd->prot_sdb = prot;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900264 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 }
266
267 return cmd;
268}
269
Rob Landleyeb448202007-11-03 13:30:39 -0500270/**
271 * scsi_get_command - Allocate and setup a scsi command block
272 * @dev: parent scsi device
273 * @gfp_mask: allocator flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 *
275 * Returns: The allocated scsi command structure.
276 */
Al Viroc53033f2005-10-21 03:22:08 -0400277struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278{
Christoph Hellwig04796332014-02-20 14:20:55 -0800279 struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
280 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Christoph Hellwig04796332014-02-20 14:20:55 -0800282 if (unlikely(cmd == NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 return NULL;
284
Christoph Hellwig04796332014-02-20 14:20:55 -0800285 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 return cmd;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900293}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
Rob Landleyeb448202007-11-03 13:30:39 -0500295/**
296 * __scsi_put_command - Free a struct scsi_cmnd
297 * @shost: dev->host
298 * @cmd: Command to free
Rob Landleyeb448202007-11-03 13:30:39 -0500299 */
Christoph Hellwigf1bea552014-04-15 12:26:54 +0200300static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900301{
302 unsigned long flags;
303
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900304 if (unlikely(list_empty(&shost->free_list))) {
Christoph Hellwig44b93b52014-02-20 14:20:53 -0800305 spin_lock_irqsave(&shost->free_list_lock, flags);
306 if (list_empty(&shost->free_list)) {
307 list_add(&cmd->list, &shost->free_list);
308 cmd = NULL;
309 }
310 spin_unlock_irqrestore(&shost->free_list_lock, flags);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900311 }
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900312
James Bottomleye507e302008-03-13 11:16:33 -0500313 if (likely(cmd != NULL))
Christoph Hellwig7c283342014-02-20 14:21:00 -0800314 scsi_host_free_command(shost, cmd);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900315}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900316
Rob Landleyeb448202007-11-03 13:30:39 -0500317/**
318 * scsi_put_command - Free a scsi command block
319 * @cmd: command block to free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 *
321 * Returns: Nothing.
322 *
323 * Notes: The command must not belong to any lists.
324 */
325void scsi_put_command(struct scsi_cmnd *cmd)
326{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 unsigned long flags;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 /* serious error if the command hasn't come from a device list */
330 spin_lock_irqsave(&cmd->device->list_lock, flags);
331 BUG_ON(list_empty(&cmd->list));
332 list_del_init(&cmd->list);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900333 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
Bart Van Asschefcc95a72014-06-02 11:50:52 +0200335 BUG_ON(delayed_work_pending(&cmd->abort_work));
Hannes Reineckee494f6a2013-11-11 13:44:54 +0100336
Christoph Hellwig04796332014-02-20 14:20:55 -0800337 __scsi_put_command(cmd->device->host, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800340static struct scsi_host_cmd_pool *
341scsi_find_host_cmd_pool(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342{
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800343 if (shost->hostt->cmd_size)
344 return shost->hostt->cmd_pool;
345 if (shost->unchecked_isa_dma)
346 return &scsi_cmd_dma_pool;
347 return &scsi_cmd_pool;
348}
349
350static void
351scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
352{
353 kfree(pool->sense_name);
354 kfree(pool->cmd_name);
355 kfree(pool);
356}
357
358static struct scsi_host_cmd_pool *
359scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
360{
361 struct scsi_host_template *hostt = shost->hostt;
362 struct scsi_host_cmd_pool *pool;
363
364 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
365 if (!pool)
366 return NULL;
367
James Bottomley884ffee2014-07-26 12:21:26 -0400368 pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name);
369 pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->proc_name);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800370 if (!pool->cmd_name || !pool->sense_name) {
371 scsi_free_host_cmd_pool(pool);
372 return NULL;
373 }
374
375 pool->slab_flags = SLAB_HWCACHE_ALIGN;
376 if (shost->unchecked_isa_dma) {
377 pool->slab_flags |= SLAB_CACHE_DMA;
378 pool->gfp_mask = __GFP_DMA;
379 }
Juergen Grossf6105c02014-08-04 13:30:02 +0200380
381 if (hostt->cmd_size)
382 hostt->cmd_pool = pool;
383
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800384 return pool;
385}
386
387static struct scsi_host_cmd_pool *
388scsi_get_host_cmd_pool(struct Scsi_Host *shost)
389{
390 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500391 struct scsi_host_cmd_pool *retval = NULL, *pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800392 size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
393
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 /*
395 * Select a command slab for this host and create it if not
Rob Landleyeb448202007-11-03 13:30:39 -0500396 * yet existent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 */
Arjan van de Ven0b950672006-01-11 13:16:10 +0100398 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800399 pool = scsi_find_host_cmd_pool(shost);
400 if (!pool) {
401 pool = scsi_alloc_host_cmd_pool(shost);
402 if (!pool)
403 goto out;
404 }
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 if (!pool->users) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800407 pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
James Bottomley5b7f1682008-01-20 09:28:24 -0600408 pool->slab_flags, NULL);
409 if (!pool->cmd_slab)
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800410 goto out_free_pool;
James Bottomley5b7f1682008-01-20 09:28:24 -0600411
412 pool->sense_slab = kmem_cache_create(pool->sense_name,
413 SCSI_SENSE_BUFFERSIZE, 0,
414 pool->slab_flags, NULL);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800415 if (!pool->sense_slab)
416 goto out_free_slab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 }
418
419 pool->users++;
James Bottomley1c353f72008-03-13 11:19:36 -0500420 retval = pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800421out:
Arjan van de Ven0b950672006-01-11 13:16:10 +0100422 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500423 return retval;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800424
425out_free_slab:
426 kmem_cache_destroy(pool->cmd_slab);
427out_free_pool:
Juergen Grossf6105c02014-08-04 13:30:02 +0200428 if (hostt->cmd_size) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800429 scsi_free_host_cmd_pool(pool);
Juergen Grossf6105c02014-08-04 13:30:02 +0200430 hostt->cmd_pool = NULL;
431 }
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800432 goto out;
James Bottomley1c353f72008-03-13 11:19:36 -0500433}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800435static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
James Bottomley1c353f72008-03-13 11:19:36 -0500436{
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800437 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500438 struct scsi_host_cmd_pool *pool;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900439
FUJITA Tomonori166a7282008-01-08 07:59:05 +0900440 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800441 pool = scsi_find_host_cmd_pool(shost);
442
James Bottomley1c353f72008-03-13 11:19:36 -0500443 /*
444 * This may happen if a driver has a mismatched get and put
445 * of the command pool; the driver should be implicated in
446 * the stack trace
447 */
448 BUG_ON(pool->users == 0);
449
James Bottomley5b7f1682008-01-20 09:28:24 -0600450 if (!--pool->users) {
451 kmem_cache_destroy(pool->cmd_slab);
452 kmem_cache_destroy(pool->sense_slab);
Juergen Grossf6105c02014-08-04 13:30:02 +0200453 if (hostt->cmd_size) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800454 scsi_free_host_cmd_pool(pool);
Juergen Grossf6105c02014-08-04 13:30:02 +0200455 hostt->cmd_pool = NULL;
456 }
James Bottomley5b7f1682008-01-20 09:28:24 -0600457 }
Arjan van de Ven0b950672006-01-11 13:16:10 +0100458 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500459}
460
461/**
James Bottomley1c353f72008-03-13 11:19:36 -0500462 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
463 * @shost: host to allocate the freelist for.
464 *
465 * Description: The command freelist protects against system-wide out of memory
466 * deadlock by preallocating one SCSI command structure for each host, so the
467 * system can always write to a swap file on a device associated with that host.
468 *
469 * Returns: Nothing.
470 */
471int scsi_setup_command_freelist(struct Scsi_Host *shost)
472{
James Bottomley1c353f72008-03-13 11:19:36 -0500473 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800474 struct scsi_cmnd *cmd;
James Bottomley1c353f72008-03-13 11:19:36 -0500475
476 spin_lock_init(&shost->free_list_lock);
477 INIT_LIST_HEAD(&shost->free_list);
478
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800479 shost->cmd_pool = scsi_get_host_cmd_pool(shost);
James Bottomley1c353f72008-03-13 11:19:36 -0500480 if (!shost->cmd_pool)
481 return -ENOMEM;
482
483 /*
484 * Get one backup command for this host.
485 */
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400486 cmd = scsi_host_alloc_command(shost, gfp_mask);
James Bottomley1c353f72008-03-13 11:19:36 -0500487 if (!cmd) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800488 scsi_put_host_cmd_pool(shost);
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400489 shost->cmd_pool = NULL;
James Bottomley1c353f72008-03-13 11:19:36 -0500490 return -ENOMEM;
491 }
492 list_add(&cmd->list, &shost->free_list);
493 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494}
495
Rob Landleyeb448202007-11-03 13:30:39 -0500496/**
497 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
498 * @shost: host whose freelist is going to be destroyed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 */
500void scsi_destroy_command_freelist(struct Scsi_Host *shost)
501{
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400502 /*
503 * If cmd_pool is NULL the free list was not initialized, so
504 * do not attempt to release resources.
505 */
506 if (!shost->cmd_pool)
507 return;
508
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 while (!list_empty(&shost->free_list)) {
510 struct scsi_cmnd *cmd;
511
512 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
513 list_del_init(&cmd->list);
Christoph Hellwig7c283342014-02-20 14:21:00 -0800514 scsi_host_free_command(shost, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 }
James Bottomley1c353f72008-03-13 11:19:36 -0500516 shost->cmd_pool = NULL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800517 scsi_put_host_cmd_pool(shost);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900518}
519
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520#ifdef CONFIG_SCSI_LOGGING
521void scsi_log_send(struct scsi_cmnd *cmd)
522{
523 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
525 /*
526 * If ML QUEUE log level is greater than or equal to:
527 *
528 * 1: nothing (match completion)
529 *
530 * 2: log opcode + command of all commands
531 *
532 * 3: same as 2 plus dump cmd address
533 *
534 * 4: same as 3 plus dump extra junk
535 */
536 if (unlikely(scsi_logging_level)) {
537 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
538 SCSI_LOG_MLQUEUE_BITS);
539 if (level > 1) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500540 scmd_printk(KERN_INFO, cmd, "Send: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 if (level > 2)
542 printk("0x%p ", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500543 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 scsi_print_command(cmd);
545 if (level > 3) {
546 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800547 " queuecommand 0x%p\n",
Boaz Harrosha73e45b2007-07-04 21:26:01 +0300548 scsi_sglist(cmd), scsi_bufflen(cmd),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500549 cmd->device->host->hostt->queuecommand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
551 }
552 }
553 }
554}
555
556void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
557{
558 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 /*
561 * If ML COMPLETE log level is greater than or equal to:
562 *
563 * 1: log disposition, result, opcode + command, and conditionally
564 * sense data for failures or non SUCCESS dispositions.
565 *
566 * 2: same as 1 but for all command completions.
567 *
568 * 3: same as 2 plus dump cmd address
569 *
570 * 4: same as 3 plus dump extra junk
571 */
572 if (unlikely(scsi_logging_level)) {
573 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
574 SCSI_LOG_MLCOMPLETE_BITS);
575 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
576 (level > 1)) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500577 scmd_printk(KERN_INFO, cmd, "Done: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 if (level > 2)
579 printk("0x%p ", cmd);
580 /*
581 * Dump truncated values, so we usually fit within
582 * 80 chars.
583 */
584 switch (disposition) {
585 case SUCCESS:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500586 printk("SUCCESS\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 break;
588 case NEEDS_RETRY:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500589 printk("RETRY\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 break;
591 case ADD_TO_MLQUEUE:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500592 printk("MLQUEUE\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 break;
594 case FAILED:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500595 printk("FAILED\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 break;
597 case TIMEOUT_ERROR:
598 /*
599 * If called via scsi_times_out.
600 */
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500601 printk("TIMEOUT\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 break;
603 default:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500604 printk("UNKNOWN\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 }
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500606 scsi_print_result(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500608 if (status_byte(cmd->result) & CHECK_CONDITION)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 scsi_print_sense("", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500610 if (level > 3)
611 scmd_printk(KERN_INFO, cmd,
612 "scsi host busy %d failed %d\n",
Christoph Hellwig74665012014-01-22 15:29:29 +0100613 atomic_read(&cmd->device->host->host_busy),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500614 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 }
616 }
617}
618#endif
619
Rob Landleyeb448202007-11-03 13:30:39 -0500620/**
621 * scsi_cmd_get_serial - Assign a serial number to a command
622 * @host: the scsi host
623 * @cmd: command to assign serial number to
624 *
625 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 * and debugging purposes. Protected by the Host_Lock of host.
627 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500628void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629{
630 cmd->serial_number = host->cmd_serial_number++;
631 if (cmd->serial_number == 0)
632 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633}
Jeff Garzikf2812332010-11-16 02:10:29 -0500634EXPORT_SYMBOL(scsi_cmd_get_serial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
Rob Landleyeb448202007-11-03 13:30:39 -0500636/**
637 * scsi_dispatch_command - Dispatch a command to the low-level driver.
638 * @cmd: command block we are dispatching.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 *
Rob Landleyeb448202007-11-03 13:30:39 -0500640 * Return: nonzero return request was rejected and device's queue needs to be
641 * plugged.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 */
643int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
644{
645 struct Scsi_Host *host = cmd->device->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 int rtn = 0;
647
Jens Axboe242f9dc2008-09-14 05:55:09 -0700648 atomic_inc(&cmd->device->iorequest_cnt);
649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 /* check if the device is still usable */
651 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
652 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
653 * returns an immediate error upwards, and signals
654 * that the device is no longer present */
655 cmd->result = DID_NO_CONNECT << 16;
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100656 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 }
658
James Bottomley0f1d87a2008-08-22 16:43:59 -0500659 /* Check to see if the scsi lld made this device blocked. */
660 if (unlikely(scsi_device_blocked(cmd->device))) {
Hannes Reinecke91921e02014-06-25 16:39:59 +0200661 /*
James Bottomley0f1d87a2008-08-22 16:43:59 -0500662 * in blocked state, the command is just put back on
663 * the device queue. The suspend state has already
664 * blocked the queue so future requests should not
665 * occur until the device transitions out of the
666 * suspend state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 */
Hannes Reinecke91921e02014-06-25 16:39:59 +0200668 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
669 "queuecommand : device blocked\n"));
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100670 return SCSI_MLQUEUE_DEVICE_BUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 }
672
Hannes Reinecke91921e02014-06-25 16:39:59 +0200673 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 * If SCSI-2 or lower, store the LUN value in cmnd.
675 */
James Bottomley4d7db042006-03-31 20:07:45 -0600676 if (cmd->device->scsi_level <= SCSI_2 &&
677 cmd->device->scsi_level != SCSI_UNKNOWN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
679 (cmd->device->lun << 5 & 0xe0);
680 }
681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 scsi_log_send(cmd);
683
684 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 * Before we queue this command, check if the command
686 * length exceeds what the host adapter can handle.
687 */
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300688 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
Hannes Reinecke91921e02014-06-25 16:39:59 +0200689 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
690 "queuecommand : command too long. "
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300691 "cdb_size=%d host->max_cmd_len=%d\n",
692 cmd->cmd_len, cmd->device->host->max_cmd_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 cmd->result = (DID_ABORT << 16);
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100694 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 }
696
Mike Andersond2c9d9e2005-06-16 11:13:42 -0700697 if (unlikely(host->shost_state == SHOST_DEL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 cmd->result = (DID_NO_CONNECT << 16);
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100699 goto done;
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 }
Jeff Garzikf2812332010-11-16 02:10:29 -0500702
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100703 trace_scsi_dispatch_cmd_start(cmd);
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100704 rtn = host->hostt->queuecommand(host, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 if (rtn) {
Kei Tokunagabf816232010-04-01 20:41:40 +0900706 trace_scsi_dispatch_cmd_error(cmd, rtn);
Mike Christief0c0a372008-08-17 15:24:38 -0500707 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
708 rtn != SCSI_MLQUEUE_TARGET_BUSY)
709 rtn = SCSI_MLQUEUE_HOST_BUSY;
710
Hannes Reinecke91921e02014-06-25 16:39:59 +0200711 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
712 "queuecommand : request rejected\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 return rtn;
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100716 done:
Christoph Hellwig3b5382c2014-05-06 12:25:40 +0200717 cmd->scsi_done(cmd);
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +0100718 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719}
720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721/**
Rob Landleyeb448202007-11-03 13:30:39 -0500722 * scsi_finish_command - cleanup and pass command back to upper layer
723 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 *
Rob Landleyeb448202007-11-03 13:30:39 -0500725 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 * request, waking processes that are waiting on results,
727 * etc.
728 */
729void scsi_finish_command(struct scsi_cmnd *cmd)
730{
731 struct scsi_device *sdev = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500732 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800734 struct scsi_driver *drv;
735 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 scsi_device_unbusy(sdev);
738
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100739 /*
740 * Clear the flags that say that the device/target/host is no longer
741 * capable of accepting new commands.
742 */
743 if (atomic_read(&shost->host_blocked))
744 atomic_set(&shost->host_blocked, 0);
745 if (atomic_read(&starget->target_blocked))
746 atomic_set(&starget->target_blocked, 0);
747 if (atomic_read(&sdev->device_blocked))
748 atomic_set(&sdev->device_blocked, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749
750 /*
751 * If we have valid sense information, then some kind of recovery
752 * must have taken place. Make a note of this.
753 */
754 if (SCSI_SENSE_VALID(cmd))
755 cmd->result |= (DRIVER_SENSE << 24);
756
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400757 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
758 "Notifying upper driver of completion "
759 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200761 good_bytes = scsi_bufflen(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800762 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
James Bottomley427e59f2008-03-08 18:24:17 -0600763 int old_good_bytes = good_bytes;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800764 drv = scsi_cmd_to_driver(cmd);
765 if (drv->done)
766 good_bytes = drv->done(cmd);
James Bottomley427e59f2008-03-08 18:24:17 -0600767 /*
768 * USB may not give sense identifying bad sector and
769 * simply return a residue instead, so subtract off the
770 * residue if drv->done() error processing indicates no
771 * change to the completion length.
772 */
773 if (good_bytes == old_good_bytes)
774 good_bytes -= scsi_get_resid(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800775 }
776 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
Rob Landleyeb448202007-11-03 13:30:39 -0500779/**
780 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
781 * @sdev: SCSI Device in question
782 * @tagged: Do we use tagged queueing (non-0) or do we treat
783 * this device as an untagged device (0)
784 * @tags: Number of tags allowed if tagged queueing enabled,
785 * or number of commands the low level driver can
786 * queue up in non-tagged mode (as per cmd_per_lun).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 *
788 * Returns: Nothing
789 *
790 * Lock Status: None held on entry
791 *
792 * Notes: Low level drivers may call this at any time and we will do
793 * the right thing depending on whether or not the device is
794 * currently active and whether or not it even has the
795 * command blocks built yet.
796 */
797void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
798{
799 unsigned long flags;
800
801 /*
802 * refuse to set tagged depth to an unworkable size
803 */
804 if (tags <= 0)
805 return;
806
807 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
808
Mike Christie885ace92008-07-11 19:50:32 -0500809 /*
810 * Check to see if the queue is managed by the block layer.
811 * If it is, and we fail to adjust the depth, exit.
812 *
813 * Do not resize the tag map if it is a host wide share bqt,
814 * because the size should be the hosts's can_queue. If there
815 * is more IO than the LLD's can_queue (so there are not enuogh
816 * tags) request_fn's host queue ready check will handle it.
817 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100818 if (!shost_use_blk_mq(sdev->host) && !sdev->host->bqt) {
Mike Christie885ace92008-07-11 19:50:32 -0500819 if (blk_queue_tagged(sdev->request_queue) &&
820 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
821 goto out;
822 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823
824 sdev->queue_depth = tags;
825 switch (tagged) {
Douglas Gilbertcb23f912014-07-07 18:00:35 +0200826 case 0:
827 sdev->ordered_tags = 0;
828 sdev->simple_tags = 0;
829 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 case MSG_ORDERED_TAG:
831 sdev->ordered_tags = 1;
832 sdev->simple_tags = 1;
833 break;
834 case MSG_SIMPLE_TAG:
835 sdev->ordered_tags = 0;
836 sdev->simple_tags = 1;
837 break;
838 default:
Douglas Gilbertcb23f912014-07-07 18:00:35 +0200839 sdev->ordered_tags = 0;
840 sdev->simple_tags = 0;
James Bottomley9ccfc752005-10-02 11:45:08 -0500841 sdev_printk(KERN_WARNING, sdev,
842 "scsi_adjust_queue_depth, bad queue type, "
843 "disabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 }
845 out:
846 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
847}
848EXPORT_SYMBOL(scsi_adjust_queue_depth);
849
Rob Landleyeb448202007-11-03 13:30:39 -0500850/**
851 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
852 * @sdev: SCSI Device in question
853 * @depth: Current number of outstanding SCSI commands on this device,
854 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 *
Rob Landleyeb448202007-11-03 13:30:39 -0500856 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 * specific SCSI device to determine if and when there is a
858 * need to adjust the queue depth on the device.
859 *
Rob Landleyeb448202007-11-03 13:30:39 -0500860 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 * -1 - Drop back to untagged operation using host->cmd_per_lun
862 * as the untagged command depth
863 *
864 * Lock Status: None held on entry
865 *
866 * Notes: Low level drivers may call this at any time and we will do
867 * "The Right Thing." We are interrupt context safe.
868 */
869int scsi_track_queue_full(struct scsi_device *sdev, int depth)
870{
Vasu Dev4a840672009-10-22 15:46:33 -0700871
872 /*
873 * Don't let QUEUE_FULLs on the same
874 * jiffies count, they could all be from
875 * same event.
876 */
877 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 return 0;
879
Vasu Dev4a840672009-10-22 15:46:33 -0700880 sdev->last_queue_full_time = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 if (sdev->last_queue_full_depth != depth) {
882 sdev->last_queue_full_count = 1;
883 sdev->last_queue_full_depth = depth;
884 } else {
885 sdev->last_queue_full_count++;
886 }
887
888 if (sdev->last_queue_full_count <= 10)
889 return 0;
890 if (sdev->last_queue_full_depth < 8) {
891 /* Drop back to untagged */
892 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
893 return -1;
894 }
895
896 if (sdev->ordered_tags)
897 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
898 else
899 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
900 return depth;
901}
902EXPORT_SYMBOL(scsi_track_queue_full);
903
904/**
Matthew Wilcox881a2562008-12-31 13:12:46 -0500905 * scsi_vpd_inquiry - Request a device provide us with a VPD page
906 * @sdev: The device to ask
907 * @buffer: Where to put the result
908 * @page: Which Vital Product Data to return
909 * @len: The length of the buffer
910 *
911 * This is an internal helper function. You probably want to use
912 * scsi_get_vpd_page instead.
913 *
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100914 * Returns size of the vpd page on success or a negative error number.
Matthew Wilcox881a2562008-12-31 13:12:46 -0500915 */
916static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
917 u8 page, unsigned len)
918{
919 int result;
920 unsigned char cmd[16];
921
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100922 if (len < 4)
923 return -EINVAL;
924
Matthew Wilcox881a2562008-12-31 13:12:46 -0500925 cmd[0] = INQUIRY;
926 cmd[1] = 1; /* EVPD */
927 cmd[2] = page;
928 cmd[3] = len >> 8;
929 cmd[4] = len & 0xff;
930 cmd[5] = 0; /* Control byte */
931
932 /*
933 * I'm not convinced we need to try quite this hard to get VPD, but
934 * all the existing users tried this hard.
935 */
936 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
James Bottomley95a36392009-08-11 10:59:09 -0500937 len, NULL, 30 * HZ, 3, NULL);
Matthew Wilcox881a2562008-12-31 13:12:46 -0500938 if (result)
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100939 return -EIO;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500940
941 /* Sanity check that we got the page back that we asked for */
942 if (buffer[1] != page)
943 return -EIO;
944
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100945 return get_unaligned_be16(&buffer[2]) + 4;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500946}
947
948/**
949 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
950 * @sdev: The device to ask
951 * @page: Which Vital Product Data to return
Randy Dunlap786f8ba2010-02-28 17:32:45 -0800952 * @buf: where to store the VPD
953 * @buf_len: number of bytes in the VPD buffer area
Matthew Wilcox881a2562008-12-31 13:12:46 -0500954 *
955 * SCSI devices may optionally supply Vital Product Data. Each 'page'
956 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
957 * If the device supports this VPD page, this routine returns a pointer
958 * to a buffer containing the data from that page. The caller is
959 * responsible for calling kfree() on this pointer when it is no longer
960 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
961 */
James Bottomleye3deec02009-11-03 12:33:07 -0600962int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
963 int buf_len)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500964{
965 int i, result;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500966
Martin K. Petersen7562523e2013-07-30 22:58:34 -0400967 if (sdev->skip_vpd_pages)
968 goto fail;
969
Matthew Wilcox881a2562008-12-31 13:12:46 -0500970 /* Ask for all the pages supported by this device */
James Bottomleye3deec02009-11-03 12:33:07 -0600971 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100972 if (result < 4)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500973 goto fail;
974
975 /* If the user actually wanted this page, we can skip the rest */
976 if (page == 0)
Martin K. Petersen16d3ea22010-09-10 01:20:27 -0400977 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500978
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100979 for (i = 4; i < min(result, buf_len); i++)
980 if (buf[i] == page)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500981 goto found;
James Bottomleye3deec02009-11-03 12:33:07 -0600982
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100983 if (i < result && i >= buf_len)
James Bottomleye3deec02009-11-03 12:33:07 -0600984 /* ran off the end of the buffer, give us benefit of doubt */
985 goto found;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500986 /* The device claims it doesn't support the requested page */
987 goto fail;
988
989 found:
James Bottomleye3deec02009-11-03 12:33:07 -0600990 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100991 if (result < 0)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500992 goto fail;
993
James Bottomleye3deec02009-11-03 12:33:07 -0600994 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500995
996 fail:
James Bottomleye3deec02009-11-03 12:33:07 -0600997 return -EINVAL;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500998}
999EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
1000
1001/**
Hannes Reineckeb3ae8782014-03-15 09:51:49 +01001002 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
1003 * @sdev: The device to ask
1004 *
1005 * Attach the 'Device Identification' VPD page (0x83) and the
1006 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
1007 * structure. This information can be used to identify the device
1008 * uniquely.
1009 */
1010void scsi_attach_vpd(struct scsi_device *sdev)
1011{
1012 int result, i;
1013 int vpd_len = SCSI_VPD_PG_LEN;
1014 int pg80_supported = 0;
1015 int pg83_supported = 0;
1016 unsigned char *vpd_buf;
1017
1018 if (sdev->skip_vpd_pages)
1019 return;
1020retry_pg0:
1021 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1022 if (!vpd_buf)
1023 return;
1024
1025 /* Ask for all the pages supported by this device */
1026 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
1027 if (result < 0) {
1028 kfree(vpd_buf);
1029 return;
1030 }
1031 if (result > vpd_len) {
1032 vpd_len = result;
1033 kfree(vpd_buf);
1034 goto retry_pg0;
1035 }
1036
1037 for (i = 4; i < result; i++) {
1038 if (vpd_buf[i] == 0x80)
1039 pg80_supported = 1;
1040 if (vpd_buf[i] == 0x83)
1041 pg83_supported = 1;
1042 }
1043 kfree(vpd_buf);
1044 vpd_len = SCSI_VPD_PG_LEN;
1045
1046 if (pg80_supported) {
1047retry_pg80:
1048 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1049 if (!vpd_buf)
1050 return;
1051
1052 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
1053 if (result < 0) {
1054 kfree(vpd_buf);
1055 return;
1056 }
1057 if (result > vpd_len) {
1058 vpd_len = result;
1059 kfree(vpd_buf);
1060 goto retry_pg80;
1061 }
1062 sdev->vpd_pg80_len = result;
1063 sdev->vpd_pg80 = vpd_buf;
1064 vpd_len = SCSI_VPD_PG_LEN;
1065 }
1066
1067 if (pg83_supported) {
1068retry_pg83:
1069 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1070 if (!vpd_buf)
1071 return;
1072
1073 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
1074 if (result < 0) {
1075 kfree(vpd_buf);
1076 return;
1077 }
1078 if (result > vpd_len) {
1079 vpd_len = result;
1080 kfree(vpd_buf);
1081 goto retry_pg83;
1082 }
1083 sdev->vpd_pg83_len = result;
1084 sdev->vpd_pg83 = vpd_buf;
1085 }
1086}
1087
1088/**
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001089 * scsi_report_opcode - Find out if a given command opcode is supported
1090 * @sdev: scsi device to query
1091 * @buffer: scratch buffer (must be at least 20 bytes long)
1092 * @len: length of buffer
1093 * @opcode: opcode for command to look up
1094 *
1095 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001096 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
1097 * unsupported and 1 if the device claims to support the command.
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001098 */
1099int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
1100 unsigned int len, unsigned char opcode)
1101{
1102 unsigned char cmd[16];
1103 struct scsi_sense_hdr sshdr;
1104 int result;
1105
1106 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001107 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001108
1109 memset(cmd, 0, 16);
1110 cmd[0] = MAINTENANCE_IN;
1111 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
1112 cmd[2] = 1; /* One command format */
1113 cmd[3] = opcode;
1114 put_unaligned_be32(len, &cmd[6]);
1115 memset(buffer, 0, len);
1116
1117 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
1118 &sshdr, 30 * HZ, 3, NULL);
1119
1120 if (result && scsi_sense_valid(&sshdr) &&
1121 sshdr.sense_key == ILLEGAL_REQUEST &&
1122 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001123 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001124
1125 if ((buffer[1] & 3) == 3) /* Command supported */
1126 return 1;
1127
1128 return 0;
1129}
1130EXPORT_SYMBOL(scsi_report_opcode);
1131
1132/**
Rob Landleyeb448202007-11-03 13:30:39 -05001133 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 * @sdev: device to get a reference to
1135 *
Rob Landleyeb448202007-11-03 13:30:39 -05001136 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 * of the underlying LLDD module. You must hold host_lock of the
1138 * parent Scsi_Host or already have a reference when calling this.
1139 */
1140int scsi_device_get(struct scsi_device *sdev)
1141{
James Bottomley85b6c722006-08-31 18:15:22 -04001142 if (sdev->sdev_state == SDEV_DEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 return -ENXIO;
1144 if (!get_device(&sdev->sdev_gendev))
1145 return -ENXIO;
James Bottomley85b6c722006-08-31 18:15:22 -04001146 /* We can fail this if we're doing SCSI operations
1147 * from module exit (like cache flush) */
1148 try_module_get(sdev->host->hostt->module);
1149
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 return 0;
1151}
1152EXPORT_SYMBOL(scsi_device_get);
1153
1154/**
1155 * scsi_device_put - release a reference to a scsi_device
1156 * @sdev: device to release a reference on.
1157 *
Rob Landleyeb448202007-11-03 13:30:39 -05001158 * Description: Release a reference to the scsi_device and decrements the use
1159 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 * user vanishes.
1161 */
1162void scsi_device_put(struct scsi_device *sdev)
1163{
Ingo Molnar504fb372006-11-09 10:09:35 +01001164#ifdef CONFIG_MODULE_UNLOAD
James Bottomleyf479ab82006-09-06 09:00:29 -05001165 struct module *module = sdev->host->hostt->module;
1166
James Bottomley85b6c722006-08-31 18:15:22 -04001167 /* The module refcount will be zero if scsi_device_get()
1168 * was called from a module removal routine */
James Bottomleyf479ab82006-09-06 09:00:29 -05001169 if (module && module_refcount(module) != 0)
1170 module_put(module);
Daniel Walkera506b442006-09-09 09:31:03 -07001171#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 put_device(&sdev->sdev_gendev);
1173}
1174EXPORT_SYMBOL(scsi_device_put);
1175
Rob Landleyeb448202007-11-03 13:30:39 -05001176/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1178 struct scsi_device *prev)
1179{
1180 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1181 struct scsi_device *next = NULL;
1182 unsigned long flags;
1183
1184 spin_lock_irqsave(shost->host_lock, flags);
1185 while (list->next != &shost->__devices) {
1186 next = list_entry(list->next, struct scsi_device, siblings);
1187 /* skip devices that we can't get a reference to */
1188 if (!scsi_device_get(next))
1189 break;
1190 next = NULL;
1191 list = list->next;
1192 }
1193 spin_unlock_irqrestore(shost->host_lock, flags);
1194
1195 if (prev)
1196 scsi_device_put(prev);
1197 return next;
1198}
1199EXPORT_SYMBOL(__scsi_iterate_devices);
1200
1201/**
1202 * starget_for_each_device - helper to walk all devices of a target
1203 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -05001204 * @data: Opaque passed to each function call.
1205 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001207 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 * a reference that must be released by scsi_host_put when breaking
1209 * out of the loop.
1210 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001211void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 void (*fn)(struct scsi_device *, void *))
1213{
1214 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1215 struct scsi_device *sdev;
1216
1217 shost_for_each_device(sdev, shost) {
1218 if ((sdev->channel == starget->channel) &&
1219 (sdev->id == starget->id))
1220 fn(sdev, data);
1221 }
1222}
1223EXPORT_SYMBOL(starget_for_each_device);
1224
1225/**
Randy Dunlap14f501a2008-02-03 15:06:36 -08001226 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001227 * @starget: target whose devices we want to iterate over.
Randy Dunlap14f501a2008-02-03 15:06:36 -08001228 * @data: parameter for callback @fn()
1229 * @fn: callback function that is invoked for each device
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001230 *
1231 * This traverses over each device of @starget. It does _not_
1232 * take a reference on the scsi_device, so the whole loop must be
1233 * protected by shost->host_lock.
1234 *
1235 * Note: The only reason why drivers would want to use this is because
1236 * they need to access the device list in irq context. Otherwise you
1237 * really want to use starget_for_each_device instead.
1238 **/
1239void __starget_for_each_device(struct scsi_target *starget, void *data,
1240 void (*fn)(struct scsi_device *, void *))
1241{
1242 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1243 struct scsi_device *sdev;
1244
1245 __shost_for_each_device(sdev, shost) {
1246 if ((sdev->channel == starget->channel) &&
1247 (sdev->id == starget->id))
1248 fn(sdev, data);
1249 }
1250}
1251EXPORT_SYMBOL(__starget_for_each_device);
1252
1253/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1255 * @starget: SCSI target pointer
1256 * @lun: SCSI Logical Unit Number
1257 *
Rob Landleyeb448202007-11-03 13:30:39 -05001258 * Description: Looks up the scsi_device with the specified @lun for a given
1259 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 * reference. You must hold the host's host_lock over this call and
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001261 * any access to the returned scsi_device. A scsi_device in state
1262 * SDEV_DEL is skipped.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -08001264 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001265 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 * really want to use scsi_device_lookup_by_target instead.
1267 **/
1268struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001269 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270{
1271 struct scsi_device *sdev;
1272
1273 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001274 if (sdev->sdev_state == SDEV_DEL)
1275 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 if (sdev->lun ==lun)
1277 return sdev;
1278 }
1279
1280 return NULL;
1281}
1282EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1283
1284/**
1285 * scsi_device_lookup_by_target - find a device given the target
1286 * @starget: SCSI target pointer
1287 * @lun: SCSI Logical Unit Number
1288 *
Bartlomiej Zolnierkiewicz477e6082009-04-27 20:54:22 +02001289 * Description: Looks up the scsi_device with the specified @lun for a given
1290 * @starget. The returned scsi_device has an additional reference that
Rob Landleyeb448202007-11-03 13:30:39 -05001291 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 **/
1293struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001294 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295{
1296 struct scsi_device *sdev;
1297 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1298 unsigned long flags;
1299
1300 spin_lock_irqsave(shost->host_lock, flags);
1301 sdev = __scsi_device_lookup_by_target(starget, lun);
1302 if (sdev && scsi_device_get(sdev))
1303 sdev = NULL;
1304 spin_unlock_irqrestore(shost->host_lock, flags);
1305
1306 return sdev;
1307}
1308EXPORT_SYMBOL(scsi_device_lookup_by_target);
1309
1310/**
Rob Landleyeb448202007-11-03 13:30:39 -05001311 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 * @shost: SCSI host pointer
1313 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -05001314 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 * @lun: SCSI Logical Unit Number
1316 *
Rob Landleyeb448202007-11-03 13:30:39 -05001317 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1318 * for a given host. The returned scsi_device does not have an additional
1319 * reference. You must hold the host's host_lock over this call and any access
1320 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 *
1322 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001323 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 * really want to use scsi_device_lookup instead.
1325 **/
1326struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001327 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328{
1329 struct scsi_device *sdev;
1330
1331 list_for_each_entry(sdev, &shost->__devices, siblings) {
1332 if (sdev->channel == channel && sdev->id == id &&
1333 sdev->lun ==lun)
1334 return sdev;
1335 }
1336
1337 return NULL;
1338}
1339EXPORT_SYMBOL(__scsi_device_lookup);
1340
1341/**
1342 * scsi_device_lookup - find a device given the host
1343 * @shost: SCSI host pointer
1344 * @channel: SCSI channel (zero if only one channel)
1345 * @id: SCSI target number (physical unit number)
1346 * @lun: SCSI Logical Unit Number
1347 *
Rob Landleyeb448202007-11-03 13:30:39 -05001348 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1349 * for a given host. The returned scsi_device has an additional reference that
1350 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 **/
1352struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001353 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354{
1355 struct scsi_device *sdev;
1356 unsigned long flags;
1357
1358 spin_lock_irqsave(shost->host_lock, flags);
1359 sdev = __scsi_device_lookup(shost, channel, id, lun);
1360 if (sdev && scsi_device_get(sdev))
1361 sdev = NULL;
1362 spin_unlock_irqrestore(shost->host_lock, flags);
1363
1364 return sdev;
1365}
1366EXPORT_SYMBOL(scsi_device_lookup);
1367
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368MODULE_DESCRIPTION("SCSI core");
1369MODULE_LICENSE("GPL");
1370
1371module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1372MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1373
Christoph Hellwigd2852032014-01-17 12:06:53 +01001374bool scsi_use_blk_mq = false;
1375module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
1376
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377static int __init init_scsi(void)
1378{
Jens Axboe9bf09c232006-09-30 20:31:11 +02001379 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380
1381 error = scsi_init_queue();
1382 if (error)
1383 return error;
1384 error = scsi_init_procfs();
1385 if (error)
1386 goto cleanup_queue;
1387 error = scsi_init_devinfo();
1388 if (error)
1389 goto cleanup_procfs;
1390 error = scsi_init_hosts();
1391 if (error)
1392 goto cleanup_devlist;
1393 error = scsi_init_sysctl();
1394 if (error)
1395 goto cleanup_hosts;
1396 error = scsi_sysfs_register();
1397 if (error)
1398 goto cleanup_sysctl;
1399
James Smart84314fd2006-08-18 17:30:09 -04001400 scsi_netlink_init();
1401
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1403 return 0;
1404
1405cleanup_sysctl:
1406 scsi_exit_sysctl();
1407cleanup_hosts:
1408 scsi_exit_hosts();
1409cleanup_devlist:
1410 scsi_exit_devinfo();
1411cleanup_procfs:
1412 scsi_exit_procfs();
1413cleanup_queue:
1414 scsi_exit_queue();
1415 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1416 -error);
1417 return error;
1418}
1419
1420static void __exit exit_scsi(void)
1421{
James Smart84314fd2006-08-18 17:30:09 -04001422 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 scsi_sysfs_unregister();
1424 scsi_exit_sysctl();
1425 scsi_exit_hosts();
1426 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 scsi_exit_procfs();
1428 scsi_exit_queue();
Dan Williamsa4683482012-07-09 19:33:30 -07001429 async_unregister_domain(&scsi_sd_probe_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430}
1431
1432subsys_initcall(init_scsi);
1433module_exit(exit_scsi);