blob: 321f854947b422871afcc7415826e5db54669142 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
5 *
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
12 * Bug correction thanks go to :
13 * Rik Faith <faith@cs.unc.edu>
14 * Tommy Thorn <tthorn>
15 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
16 *
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
19 * enhancements.
20 *
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
23 *
24 * Added request_module("scsi_hostadapter") for kerneld:
25 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
26 * Bjorn Ekwall <bj0rn@blox.se>
27 * (changed to kmod)
28 *
29 * Major improvements to the timeout, abort, and reset processing,
30 * as well as performance modifications for large queue depths by
31 * Leonard N. Zubkoff <lnz@dandelion.com>
32 *
33 * Converted cli() code to spinlocks, Ingo Molnar
34 *
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
36 *
37 * out_of_space hacks, D. Gilbert (dpg) 990608
38 */
39
40#include <linux/module.h>
41#include <linux/moduleparam.h>
42#include <linux/kernel.h>
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
Adrian Bunk52c1da32005-06-23 22:05:33 -070075static void scsi_done(struct scsi_cmnd *cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/*
78 * Definitions and constants.
79 */
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 * 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
James Bottomleyea80dad2012-06-06 14:54:13 +090090/* sd, scsi core and power management need to coordinate flushing async actions */
Dan Williams2955b472012-07-09 19:33:25 -070091ASYNC_DOMAIN(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070092EXPORT_SYMBOL(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070093
Dan Williams3c31b522014-04-10 15:30:35 -070094/*
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
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600103/* 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 */
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600107static const char *const scsi_device_types[] = {
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600108 "Direct-Access ",
109 "Sequential-Access",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 "Printer ",
111 "Processor ",
112 "WORM ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600113 "CD-ROM ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 "Scanner ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600115 "Optical Device ",
116 "Medium Changer ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 "Communications ",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600118 "ASC IT8 ",
119 "ASC IT8 ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 "RAID ",
121 "Enclosure ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600122 "Direct-Access-RBC",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600123 "Optical card ",
124 "Bridge controller",
125 "Object storage ",
126 "Automation/Drive ",
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
368 pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
369 pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->name);
370 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 }
380 return pool;
381}
382
383static struct scsi_host_cmd_pool *
384scsi_get_host_cmd_pool(struct Scsi_Host *shost)
385{
386 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500387 struct scsi_host_cmd_pool *retval = NULL, *pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800388 size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 /*
391 * Select a command slab for this host and create it if not
Rob Landleyeb448202007-11-03 13:30:39 -0500392 * yet existent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 */
Arjan van de Ven0b950672006-01-11 13:16:10 +0100394 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800395 pool = scsi_find_host_cmd_pool(shost);
396 if (!pool) {
397 pool = scsi_alloc_host_cmd_pool(shost);
398 if (!pool)
399 goto out;
400 }
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 if (!pool->users) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800403 pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
James Bottomley5b7f1682008-01-20 09:28:24 -0600404 pool->slab_flags, NULL);
405 if (!pool->cmd_slab)
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800406 goto out_free_pool;
James Bottomley5b7f1682008-01-20 09:28:24 -0600407
408 pool->sense_slab = kmem_cache_create(pool->sense_name,
409 SCSI_SENSE_BUFFERSIZE, 0,
410 pool->slab_flags, NULL);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800411 if (!pool->sense_slab)
412 goto out_free_slab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 }
414
415 pool->users++;
James Bottomley1c353f72008-03-13 11:19:36 -0500416 retval = pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800417out:
Arjan van de Ven0b950672006-01-11 13:16:10 +0100418 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500419 return retval;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800420
421out_free_slab:
422 kmem_cache_destroy(pool->cmd_slab);
423out_free_pool:
424 if (hostt->cmd_size)
425 scsi_free_host_cmd_pool(pool);
426 goto out;
James Bottomley1c353f72008-03-13 11:19:36 -0500427}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800429static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
James Bottomley1c353f72008-03-13 11:19:36 -0500430{
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800431 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500432 struct scsi_host_cmd_pool *pool;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900433
FUJITA Tomonori166a7282008-01-08 07:59:05 +0900434 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800435 pool = scsi_find_host_cmd_pool(shost);
436
James Bottomley1c353f72008-03-13 11:19:36 -0500437 /*
438 * This may happen if a driver has a mismatched get and put
439 * of the command pool; the driver should be implicated in
440 * the stack trace
441 */
442 BUG_ON(pool->users == 0);
443
James Bottomley5b7f1682008-01-20 09:28:24 -0600444 if (!--pool->users) {
445 kmem_cache_destroy(pool->cmd_slab);
446 kmem_cache_destroy(pool->sense_slab);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800447 if (hostt->cmd_size)
448 scsi_free_host_cmd_pool(pool);
James Bottomley5b7f1682008-01-20 09:28:24 -0600449 }
Arjan van de Ven0b950672006-01-11 13:16:10 +0100450 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500451}
452
453/**
James Bottomley1c353f72008-03-13 11:19:36 -0500454 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
455 * @shost: host to allocate the freelist for.
456 *
457 * Description: The command freelist protects against system-wide out of memory
458 * deadlock by preallocating one SCSI command structure for each host, so the
459 * system can always write to a swap file on a device associated with that host.
460 *
461 * Returns: Nothing.
462 */
463int scsi_setup_command_freelist(struct Scsi_Host *shost)
464{
James Bottomley1c353f72008-03-13 11:19:36 -0500465 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800466 struct scsi_cmnd *cmd;
James Bottomley1c353f72008-03-13 11:19:36 -0500467
468 spin_lock_init(&shost->free_list_lock);
469 INIT_LIST_HEAD(&shost->free_list);
470
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800471 shost->cmd_pool = scsi_get_host_cmd_pool(shost);
James Bottomley1c353f72008-03-13 11:19:36 -0500472 if (!shost->cmd_pool)
473 return -ENOMEM;
474
475 /*
476 * Get one backup command for this host.
477 */
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400478 cmd = scsi_host_alloc_command(shost, gfp_mask);
James Bottomley1c353f72008-03-13 11:19:36 -0500479 if (!cmd) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800480 scsi_put_host_cmd_pool(shost);
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400481 shost->cmd_pool = NULL;
James Bottomley1c353f72008-03-13 11:19:36 -0500482 return -ENOMEM;
483 }
484 list_add(&cmd->list, &shost->free_list);
485 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486}
487
Rob Landleyeb448202007-11-03 13:30:39 -0500488/**
489 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
490 * @shost: host whose freelist is going to be destroyed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 */
492void scsi_destroy_command_freelist(struct Scsi_Host *shost)
493{
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400494 /*
495 * If cmd_pool is NULL the free list was not initialized, so
496 * do not attempt to release resources.
497 */
498 if (!shost->cmd_pool)
499 return;
500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 while (!list_empty(&shost->free_list)) {
502 struct scsi_cmnd *cmd;
503
504 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
505 list_del_init(&cmd->list);
Christoph Hellwig7c283342014-02-20 14:21:00 -0800506 scsi_host_free_command(shost, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 }
James Bottomley1c353f72008-03-13 11:19:36 -0500508 shost->cmd_pool = NULL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800509 scsi_put_host_cmd_pool(shost);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900510}
511
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512#ifdef CONFIG_SCSI_LOGGING
513void scsi_log_send(struct scsi_cmnd *cmd)
514{
515 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 /*
518 * If ML QUEUE log level is greater than or equal to:
519 *
520 * 1: nothing (match completion)
521 *
522 * 2: log opcode + command of all commands
523 *
524 * 3: same as 2 plus dump cmd address
525 *
526 * 4: same as 3 plus dump extra junk
527 */
528 if (unlikely(scsi_logging_level)) {
529 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
530 SCSI_LOG_MLQUEUE_BITS);
531 if (level > 1) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500532 scmd_printk(KERN_INFO, cmd, "Send: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 if (level > 2)
534 printk("0x%p ", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500535 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 scsi_print_command(cmd);
537 if (level > 3) {
538 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800539 " queuecommand 0x%p\n",
Boaz Harrosha73e45b2007-07-04 21:26:01 +0300540 scsi_sglist(cmd), scsi_bufflen(cmd),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500541 cmd->device->host->hostt->queuecommand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542
543 }
544 }
545 }
546}
547
548void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
549{
550 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
552 /*
553 * If ML COMPLETE log level is greater than or equal to:
554 *
555 * 1: log disposition, result, opcode + command, and conditionally
556 * sense data for failures or non SUCCESS dispositions.
557 *
558 * 2: same as 1 but for all command completions.
559 *
560 * 3: same as 2 plus dump cmd address
561 *
562 * 4: same as 3 plus dump extra junk
563 */
564 if (unlikely(scsi_logging_level)) {
565 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
566 SCSI_LOG_MLCOMPLETE_BITS);
567 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
568 (level > 1)) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500569 scmd_printk(KERN_INFO, cmd, "Done: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 if (level > 2)
571 printk("0x%p ", cmd);
572 /*
573 * Dump truncated values, so we usually fit within
574 * 80 chars.
575 */
576 switch (disposition) {
577 case SUCCESS:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500578 printk("SUCCESS\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 break;
580 case NEEDS_RETRY:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500581 printk("RETRY\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 break;
583 case ADD_TO_MLQUEUE:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500584 printk("MLQUEUE\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 break;
586 case FAILED:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500587 printk("FAILED\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 break;
589 case TIMEOUT_ERROR:
590 /*
591 * If called via scsi_times_out.
592 */
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500593 printk("TIMEOUT\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 break;
595 default:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500596 printk("UNKNOWN\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 }
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500598 scsi_print_result(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500600 if (status_byte(cmd->result) & CHECK_CONDITION)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 scsi_print_sense("", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500602 if (level > 3)
603 scmd_printk(KERN_INFO, cmd,
604 "scsi host busy %d failed %d\n",
605 cmd->device->host->host_busy,
606 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 }
608 }
609}
610#endif
611
Rob Landleyeb448202007-11-03 13:30:39 -0500612/**
613 * scsi_cmd_get_serial - Assign a serial number to a command
614 * @host: the scsi host
615 * @cmd: command to assign serial number to
616 *
617 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 * and debugging purposes. Protected by the Host_Lock of host.
619 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500620void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
622 cmd->serial_number = host->cmd_serial_number++;
623 if (cmd->serial_number == 0)
624 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625}
Jeff Garzikf2812332010-11-16 02:10:29 -0500626EXPORT_SYMBOL(scsi_cmd_get_serial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Rob Landleyeb448202007-11-03 13:30:39 -0500628/**
629 * scsi_dispatch_command - Dispatch a command to the low-level driver.
630 * @cmd: command block we are dispatching.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 *
Rob Landleyeb448202007-11-03 13:30:39 -0500632 * Return: nonzero return request was rejected and device's queue needs to be
633 * plugged.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 */
635int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
636{
637 struct Scsi_Host *host = cmd->device->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 int rtn = 0;
639
Jens Axboe242f9dc2008-09-14 05:55:09 -0700640 atomic_inc(&cmd->device->iorequest_cnt);
641
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 /* check if the device is still usable */
643 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
644 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
645 * returns an immediate error upwards, and signals
646 * that the device is no longer present */
647 cmd->result = DID_NO_CONNECT << 16;
Jens Axboe242f9dc2008-09-14 05:55:09 -0700648 scsi_done(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 /* return 0 (because the command has been processed) */
650 goto out;
651 }
652
James Bottomley0f1d87a2008-08-22 16:43:59 -0500653 /* Check to see if the scsi lld made this device blocked. */
654 if (unlikely(scsi_device_blocked(cmd->device))) {
Hannes Reinecke91921e02014-06-25 16:39:59 +0200655 /*
James Bottomley0f1d87a2008-08-22 16:43:59 -0500656 * in blocked state, the command is just put back on
657 * the device queue. The suspend state has already
658 * blocked the queue so future requests should not
659 * occur until the device transitions out of the
660 * suspend state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 */
Jens Axboe242f9dc2008-09-14 05:55:09 -0700662
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
664
Hannes Reinecke91921e02014-06-25 16:39:59 +0200665 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
666 "queuecommand : device blocked\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
668 /*
669 * NOTE: rtn is still zero here because we don't need the
670 * queue to be plugged on return (it's already stopped)
671 */
672 goto out;
673 }
674
Hannes Reinecke91921e02014-06-25 16:39:59 +0200675 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 * If SCSI-2 or lower, store the LUN value in cmnd.
677 */
James Bottomley4d7db042006-03-31 20:07:45 -0600678 if (cmd->device->scsi_level <= SCSI_2 &&
679 cmd->device->scsi_level != SCSI_UNKNOWN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
681 (cmd->device->lun << 5 & 0xe0);
682 }
683
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 scsi_log_send(cmd);
685
686 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 * Before we queue this command, check if the command
688 * length exceeds what the host adapter can handle.
689 */
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300690 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
Hannes Reinecke91921e02014-06-25 16:39:59 +0200691 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
692 "queuecommand : command too long. "
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300693 "cdb_size=%d host->max_cmd_len=%d\n",
694 cmd->cmd_len, cmd->device->host->max_cmd_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 cmd->result = (DID_ABORT << 16);
696
697 scsi_done(cmd);
698 goto out;
699 }
700
Mike Andersond2c9d9e2005-06-16 11:13:42 -0700701 if (unlikely(host->shost_state == SHOST_DEL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 cmd->result = (DID_NO_CONNECT << 16);
703 scsi_done(cmd);
704 } else {
Kei Tokunagabf816232010-04-01 20:41:40 +0900705 trace_scsi_dispatch_cmd_start(cmd);
Jeff Garzikf2812332010-11-16 02:10:29 -0500706 cmd->scsi_done = scsi_done;
707 rtn = host->hostt->queuecommand(host, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
Jeff Garzikf2812332010-11-16 02:10:29 -0500709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 if (rtn) {
Kei Tokunagabf816232010-04-01 20:41:40 +0900711 trace_scsi_dispatch_cmd_error(cmd, rtn);
Mike Christief0c0a372008-08-17 15:24:38 -0500712 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
713 rtn != SCSI_MLQUEUE_TARGET_BUSY)
714 rtn = SCSI_MLQUEUE_HOST_BUSY;
715
Hannes Reinecke91921e02014-06-25 16:39:59 +0200716 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
717 "queuecommand : request rejected\n"));
Mike Christief0c0a372008-08-17 15:24:38 -0500718
Hannes Reinecke91921e02014-06-25 16:39:59 +0200719 scsi_queue_insert(cmd, rtn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 }
721
722 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 return rtn;
724}
725
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726/**
Hannes Reinecke6ad55502013-11-11 13:44:57 +0100727 * scsi_done - Invoke completion on finished SCSI command.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
729 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
730 *
Rob Landleyeb448202007-11-03 13:30:39 -0500731 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
732 * which regains ownership of the SCSI command (de facto) from a LLDD, and
Hannes Reinecke6ad55502013-11-11 13:44:57 +0100733 * calls blk_complete_request() for further processing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 *
735 * This function is interrupt context safe.
736 */
Adrian Bunk52c1da32005-06-23 22:05:33 -0700737static void scsi_done(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738{
Kei Tokunagabf816232010-04-01 20:41:40 +0900739 trace_scsi_dispatch_cmd_done(cmd);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700740 blk_complete_request(cmd->request);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741}
742
Rob Landleyeb448202007-11-03 13:30:39 -0500743/**
744 * scsi_finish_command - cleanup and pass command back to upper layer
745 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 *
Rob Landleyeb448202007-11-03 13:30:39 -0500747 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 * request, waking processes that are waiting on results,
749 * etc.
750 */
751void scsi_finish_command(struct scsi_cmnd *cmd)
752{
753 struct scsi_device *sdev = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500754 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800756 struct scsi_driver *drv;
757 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
759 scsi_device_unbusy(sdev);
760
761 /*
762 * Clear the flags which say that the device/host is no longer
763 * capable of accepting new commands. These are set in scsi_queue.c
764 * for both the queue full condition on a device, and for a
765 * host full condition on the host.
766 *
767 * XXX(hch): What about locking?
768 */
769 shost->host_blocked = 0;
Mike Christief0c0a372008-08-17 15:24:38 -0500770 starget->target_blocked = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 sdev->device_blocked = 0;
772
773 /*
774 * If we have valid sense information, then some kind of recovery
775 * must have taken place. Make a note of this.
776 */
777 if (SCSI_SENSE_VALID(cmd))
778 cmd->result |= (DRIVER_SENSE << 24);
779
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400780 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
781 "Notifying upper driver of completion "
782 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200784 good_bytes = scsi_bufflen(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800785 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
James Bottomley427e59f2008-03-08 18:24:17 -0600786 int old_good_bytes = good_bytes;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800787 drv = scsi_cmd_to_driver(cmd);
788 if (drv->done)
789 good_bytes = drv->done(cmd);
James Bottomley427e59f2008-03-08 18:24:17 -0600790 /*
791 * USB may not give sense identifying bad sector and
792 * simply return a residue instead, so subtract off the
793 * residue if drv->done() error processing indicates no
794 * change to the completion length.
795 */
796 if (good_bytes == old_good_bytes)
797 good_bytes -= scsi_get_resid(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800798 }
799 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
Rob Landleyeb448202007-11-03 13:30:39 -0500802/**
803 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
804 * @sdev: SCSI Device in question
805 * @tagged: Do we use tagged queueing (non-0) or do we treat
806 * this device as an untagged device (0)
807 * @tags: Number of tags allowed if tagged queueing enabled,
808 * or number of commands the low level driver can
809 * queue up in non-tagged mode (as per cmd_per_lun).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 *
811 * Returns: Nothing
812 *
813 * Lock Status: None held on entry
814 *
815 * Notes: Low level drivers may call this at any time and we will do
816 * the right thing depending on whether or not the device is
817 * currently active and whether or not it even has the
818 * command blocks built yet.
819 */
820void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
821{
822 unsigned long flags;
823
824 /*
825 * refuse to set tagged depth to an unworkable size
826 */
827 if (tags <= 0)
828 return;
829
830 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
831
Mike Christie885ace92008-07-11 19:50:32 -0500832 /*
833 * Check to see if the queue is managed by the block layer.
834 * If it is, and we fail to adjust the depth, exit.
835 *
836 * Do not resize the tag map if it is a host wide share bqt,
837 * because the size should be the hosts's can_queue. If there
838 * is more IO than the LLD's can_queue (so there are not enuogh
839 * tags) request_fn's host queue ready check will handle it.
840 */
841 if (!sdev->host->bqt) {
842 if (blk_queue_tagged(sdev->request_queue) &&
843 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
844 goto out;
845 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
847 sdev->queue_depth = tags;
848 switch (tagged) {
Douglas Gilbertcb23f912014-07-07 18:00:35 +0200849 case 0:
850 sdev->ordered_tags = 0;
851 sdev->simple_tags = 0;
852 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 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:
Douglas Gilbertcb23f912014-07-07 18:00:35 +0200862 sdev->ordered_tags = 0;
863 sdev->simple_tags = 0;
James Bottomley9ccfc752005-10-02 11:45:08 -0500864 sdev_printk(KERN_WARNING, sdev,
865 "scsi_adjust_queue_depth, bad queue type, "
866 "disabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 }
868 out:
869 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
870}
871EXPORT_SYMBOL(scsi_adjust_queue_depth);
872
Rob Landleyeb448202007-11-03 13:30:39 -0500873/**
874 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
875 * @sdev: SCSI Device in question
876 * @depth: Current number of outstanding SCSI commands on this device,
877 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 *
Rob Landleyeb448202007-11-03 13:30:39 -0500879 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 * specific SCSI device to determine if and when there is a
881 * need to adjust the queue depth on the device.
882 *
Rob Landleyeb448202007-11-03 13:30:39 -0500883 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 * -1 - Drop back to untagged operation using host->cmd_per_lun
885 * as the untagged command depth
886 *
887 * Lock Status: None held on entry
888 *
889 * Notes: Low level drivers may call this at any time and we will do
890 * "The Right Thing." We are interrupt context safe.
891 */
892int scsi_track_queue_full(struct scsi_device *sdev, int depth)
893{
Vasu Dev4a840672009-10-22 15:46:33 -0700894
895 /*
896 * Don't let QUEUE_FULLs on the same
897 * jiffies count, they could all be from
898 * same event.
899 */
900 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return 0;
902
Vasu Dev4a840672009-10-22 15:46:33 -0700903 sdev->last_queue_full_time = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 if (sdev->last_queue_full_depth != depth) {
905 sdev->last_queue_full_count = 1;
906 sdev->last_queue_full_depth = depth;
907 } else {
908 sdev->last_queue_full_count++;
909 }
910
911 if (sdev->last_queue_full_count <= 10)
912 return 0;
913 if (sdev->last_queue_full_depth < 8) {
914 /* Drop back to untagged */
915 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
916 return -1;
917 }
918
919 if (sdev->ordered_tags)
920 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
921 else
922 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
923 return depth;
924}
925EXPORT_SYMBOL(scsi_track_queue_full);
926
927/**
Matthew Wilcox881a2562008-12-31 13:12:46 -0500928 * scsi_vpd_inquiry - Request a device provide us with a VPD page
929 * @sdev: The device to ask
930 * @buffer: Where to put the result
931 * @page: Which Vital Product Data to return
932 * @len: The length of the buffer
933 *
934 * This is an internal helper function. You probably want to use
935 * scsi_get_vpd_page instead.
936 *
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100937 * Returns size of the vpd page on success or a negative error number.
Matthew Wilcox881a2562008-12-31 13:12:46 -0500938 */
939static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
940 u8 page, unsigned len)
941{
942 int result;
943 unsigned char cmd[16];
944
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100945 if (len < 4)
946 return -EINVAL;
947
Matthew Wilcox881a2562008-12-31 13:12:46 -0500948 cmd[0] = INQUIRY;
949 cmd[1] = 1; /* EVPD */
950 cmd[2] = page;
951 cmd[3] = len >> 8;
952 cmd[4] = len & 0xff;
953 cmd[5] = 0; /* Control byte */
954
955 /*
956 * I'm not convinced we need to try quite this hard to get VPD, but
957 * all the existing users tried this hard.
958 */
959 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
James Bottomley95a36392009-08-11 10:59:09 -0500960 len, NULL, 30 * HZ, 3, NULL);
Matthew Wilcox881a2562008-12-31 13:12:46 -0500961 if (result)
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100962 return -EIO;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500963
964 /* Sanity check that we got the page back that we asked for */
965 if (buffer[1] != page)
966 return -EIO;
967
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100968 return get_unaligned_be16(&buffer[2]) + 4;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500969}
970
971/**
972 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
973 * @sdev: The device to ask
974 * @page: Which Vital Product Data to return
Randy Dunlap786f8ba2010-02-28 17:32:45 -0800975 * @buf: where to store the VPD
976 * @buf_len: number of bytes in the VPD buffer area
Matthew Wilcox881a2562008-12-31 13:12:46 -0500977 *
978 * SCSI devices may optionally supply Vital Product Data. Each 'page'
979 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
980 * If the device supports this VPD page, this routine returns a pointer
981 * to a buffer containing the data from that page. The caller is
982 * responsible for calling kfree() on this pointer when it is no longer
983 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
984 */
James Bottomleye3deec02009-11-03 12:33:07 -0600985int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
986 int buf_len)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500987{
988 int i, result;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500989
Martin K. Petersen75625232013-07-30 22:58:34 -0400990 if (sdev->skip_vpd_pages)
991 goto fail;
992
Matthew Wilcox881a2562008-12-31 13:12:46 -0500993 /* Ask for all the pages supported by this device */
James Bottomleye3deec02009-11-03 12:33:07 -0600994 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100995 if (result < 4)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500996 goto fail;
997
998 /* If the user actually wanted this page, we can skip the rest */
999 if (page == 0)
Martin K. Petersen16d3ea22010-09-10 01:20:27 -04001000 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -05001001
Hannes Reineckebc8945d2014-03-15 09:51:48 +01001002 for (i = 4; i < min(result, buf_len); i++)
1003 if (buf[i] == page)
Matthew Wilcox881a2562008-12-31 13:12:46 -05001004 goto found;
James Bottomleye3deec02009-11-03 12:33:07 -06001005
Hannes Reineckebc8945d2014-03-15 09:51:48 +01001006 if (i < result && i >= buf_len)
James Bottomleye3deec02009-11-03 12:33:07 -06001007 /* ran off the end of the buffer, give us benefit of doubt */
1008 goto found;
Matthew Wilcox881a2562008-12-31 13:12:46 -05001009 /* The device claims it doesn't support the requested page */
1010 goto fail;
1011
1012 found:
James Bottomleye3deec02009-11-03 12:33:07 -06001013 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +01001014 if (result < 0)
Matthew Wilcox881a2562008-12-31 13:12:46 -05001015 goto fail;
1016
James Bottomleye3deec02009-11-03 12:33:07 -06001017 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -05001018
1019 fail:
James Bottomleye3deec02009-11-03 12:33:07 -06001020 return -EINVAL;
Matthew Wilcox881a2562008-12-31 13:12:46 -05001021}
1022EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
1023
1024/**
Hannes Reineckeb3ae8782014-03-15 09:51:49 +01001025 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
1026 * @sdev: The device to ask
1027 *
1028 * Attach the 'Device Identification' VPD page (0x83) and the
1029 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
1030 * structure. This information can be used to identify the device
1031 * uniquely.
1032 */
1033void scsi_attach_vpd(struct scsi_device *sdev)
1034{
1035 int result, i;
1036 int vpd_len = SCSI_VPD_PG_LEN;
1037 int pg80_supported = 0;
1038 int pg83_supported = 0;
1039 unsigned char *vpd_buf;
1040
1041 if (sdev->skip_vpd_pages)
1042 return;
1043retry_pg0:
1044 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1045 if (!vpd_buf)
1046 return;
1047
1048 /* Ask for all the pages supported by this device */
1049 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
1050 if (result < 0) {
1051 kfree(vpd_buf);
1052 return;
1053 }
1054 if (result > vpd_len) {
1055 vpd_len = result;
1056 kfree(vpd_buf);
1057 goto retry_pg0;
1058 }
1059
1060 for (i = 4; i < result; i++) {
1061 if (vpd_buf[i] == 0x80)
1062 pg80_supported = 1;
1063 if (vpd_buf[i] == 0x83)
1064 pg83_supported = 1;
1065 }
1066 kfree(vpd_buf);
1067 vpd_len = SCSI_VPD_PG_LEN;
1068
1069 if (pg80_supported) {
1070retry_pg80:
1071 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1072 if (!vpd_buf)
1073 return;
1074
1075 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
1076 if (result < 0) {
1077 kfree(vpd_buf);
1078 return;
1079 }
1080 if (result > vpd_len) {
1081 vpd_len = result;
1082 kfree(vpd_buf);
1083 goto retry_pg80;
1084 }
1085 sdev->vpd_pg80_len = result;
1086 sdev->vpd_pg80 = vpd_buf;
1087 vpd_len = SCSI_VPD_PG_LEN;
1088 }
1089
1090 if (pg83_supported) {
1091retry_pg83:
1092 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1093 if (!vpd_buf)
1094 return;
1095
1096 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
1097 if (result < 0) {
1098 kfree(vpd_buf);
1099 return;
1100 }
1101 if (result > vpd_len) {
1102 vpd_len = result;
1103 kfree(vpd_buf);
1104 goto retry_pg83;
1105 }
1106 sdev->vpd_pg83_len = result;
1107 sdev->vpd_pg83 = vpd_buf;
1108 }
1109}
1110
1111/**
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001112 * scsi_report_opcode - Find out if a given command opcode is supported
1113 * @sdev: scsi device to query
1114 * @buffer: scratch buffer (must be at least 20 bytes long)
1115 * @len: length of buffer
1116 * @opcode: opcode for command to look up
1117 *
1118 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001119 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
1120 * unsupported and 1 if the device claims to support the command.
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001121 */
1122int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
1123 unsigned int len, unsigned char opcode)
1124{
1125 unsigned char cmd[16];
1126 struct scsi_sense_hdr sshdr;
1127 int result;
1128
1129 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001130 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001131
1132 memset(cmd, 0, 16);
1133 cmd[0] = MAINTENANCE_IN;
1134 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
1135 cmd[2] = 1; /* One command format */
1136 cmd[3] = opcode;
1137 put_unaligned_be32(len, &cmd[6]);
1138 memset(buffer, 0, len);
1139
1140 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
1141 &sshdr, 30 * HZ, 3, NULL);
1142
1143 if (result && scsi_sense_valid(&sshdr) &&
1144 sshdr.sense_key == ILLEGAL_REQUEST &&
1145 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
Martin K. Petersen66c28f92013-06-06 22:15:55 -04001146 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -04001147
1148 if ((buffer[1] & 3) == 3) /* Command supported */
1149 return 1;
1150
1151 return 0;
1152}
1153EXPORT_SYMBOL(scsi_report_opcode);
1154
1155/**
Rob Landleyeb448202007-11-03 13:30:39 -05001156 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157 * @sdev: device to get a reference to
1158 *
Rob Landleyeb448202007-11-03 13:30:39 -05001159 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 * of the underlying LLDD module. You must hold host_lock of the
1161 * parent Scsi_Host or already have a reference when calling this.
1162 */
1163int scsi_device_get(struct scsi_device *sdev)
1164{
James Bottomley85b6c722006-08-31 18:15:22 -04001165 if (sdev->sdev_state == SDEV_DEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 return -ENXIO;
1167 if (!get_device(&sdev->sdev_gendev))
1168 return -ENXIO;
James Bottomley85b6c722006-08-31 18:15:22 -04001169 /* We can fail this if we're doing SCSI operations
1170 * from module exit (like cache flush) */
1171 try_module_get(sdev->host->hostt->module);
1172
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 return 0;
1174}
1175EXPORT_SYMBOL(scsi_device_get);
1176
1177/**
1178 * scsi_device_put - release a reference to a scsi_device
1179 * @sdev: device to release a reference on.
1180 *
Rob Landleyeb448202007-11-03 13:30:39 -05001181 * Description: Release a reference to the scsi_device and decrements the use
1182 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 * user vanishes.
1184 */
1185void scsi_device_put(struct scsi_device *sdev)
1186{
Ingo Molnar504fb372006-11-09 10:09:35 +01001187#ifdef CONFIG_MODULE_UNLOAD
James Bottomleyf479ab82006-09-06 09:00:29 -05001188 struct module *module = sdev->host->hostt->module;
1189
James Bottomley85b6c722006-08-31 18:15:22 -04001190 /* The module refcount will be zero if scsi_device_get()
1191 * was called from a module removal routine */
James Bottomleyf479ab82006-09-06 09:00:29 -05001192 if (module && module_refcount(module) != 0)
1193 module_put(module);
Daniel Walkera506b442006-09-09 09:31:03 -07001194#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 put_device(&sdev->sdev_gendev);
1196}
1197EXPORT_SYMBOL(scsi_device_put);
1198
Rob Landleyeb448202007-11-03 13:30:39 -05001199/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1201 struct scsi_device *prev)
1202{
1203 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1204 struct scsi_device *next = NULL;
1205 unsigned long flags;
1206
1207 spin_lock_irqsave(shost->host_lock, flags);
1208 while (list->next != &shost->__devices) {
1209 next = list_entry(list->next, struct scsi_device, siblings);
1210 /* skip devices that we can't get a reference to */
1211 if (!scsi_device_get(next))
1212 break;
1213 next = NULL;
1214 list = list->next;
1215 }
1216 spin_unlock_irqrestore(shost->host_lock, flags);
1217
1218 if (prev)
1219 scsi_device_put(prev);
1220 return next;
1221}
1222EXPORT_SYMBOL(__scsi_iterate_devices);
1223
1224/**
1225 * starget_for_each_device - helper to walk all devices of a target
1226 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -05001227 * @data: Opaque passed to each function call.
1228 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001230 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 * a reference that must be released by scsi_host_put when breaking
1232 * out of the loop.
1233 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001234void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 void (*fn)(struct scsi_device *, void *))
1236{
1237 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1238 struct scsi_device *sdev;
1239
1240 shost_for_each_device(sdev, shost) {
1241 if ((sdev->channel == starget->channel) &&
1242 (sdev->id == starget->id))
1243 fn(sdev, data);
1244 }
1245}
1246EXPORT_SYMBOL(starget_for_each_device);
1247
1248/**
Randy Dunlap14f501a2008-02-03 15:06:36 -08001249 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001250 * @starget: target whose devices we want to iterate over.
Randy Dunlap14f501a2008-02-03 15:06:36 -08001251 * @data: parameter for callback @fn()
1252 * @fn: callback function that is invoked for each device
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001253 *
1254 * This traverses over each device of @starget. It does _not_
1255 * take a reference on the scsi_device, so the whole loop must be
1256 * protected by shost->host_lock.
1257 *
1258 * Note: The only reason why drivers would want to use this is because
1259 * they need to access the device list in irq context. Otherwise you
1260 * really want to use starget_for_each_device instead.
1261 **/
1262void __starget_for_each_device(struct scsi_target *starget, void *data,
1263 void (*fn)(struct scsi_device *, void *))
1264{
1265 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1266 struct scsi_device *sdev;
1267
1268 __shost_for_each_device(sdev, shost) {
1269 if ((sdev->channel == starget->channel) &&
1270 (sdev->id == starget->id))
1271 fn(sdev, data);
1272 }
1273}
1274EXPORT_SYMBOL(__starget_for_each_device);
1275
1276/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1278 * @starget: SCSI target pointer
1279 * @lun: SCSI Logical Unit Number
1280 *
Rob Landleyeb448202007-11-03 13:30:39 -05001281 * Description: Looks up the scsi_device with the specified @lun for a given
1282 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 * reference. You must hold the host's host_lock over this call and
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001284 * any access to the returned scsi_device. A scsi_device in state
1285 * SDEV_DEL is skipped.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -08001287 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001288 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 * really want to use scsi_device_lookup_by_target instead.
1290 **/
1291struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001292 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293{
1294 struct scsi_device *sdev;
1295
1296 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001297 if (sdev->sdev_state == SDEV_DEL)
1298 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 if (sdev->lun ==lun)
1300 return sdev;
1301 }
1302
1303 return NULL;
1304}
1305EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1306
1307/**
1308 * scsi_device_lookup_by_target - find a device given the target
1309 * @starget: SCSI target pointer
1310 * @lun: SCSI Logical Unit Number
1311 *
Bartlomiej Zolnierkiewicz477e6082009-04-27 20:54:22 +02001312 * Description: Looks up the scsi_device with the specified @lun for a given
1313 * @starget. The returned scsi_device has an additional reference that
Rob Landleyeb448202007-11-03 13:30:39 -05001314 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 **/
1316struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001317 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318{
1319 struct scsi_device *sdev;
1320 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1321 unsigned long flags;
1322
1323 spin_lock_irqsave(shost->host_lock, flags);
1324 sdev = __scsi_device_lookup_by_target(starget, lun);
1325 if (sdev && scsi_device_get(sdev))
1326 sdev = NULL;
1327 spin_unlock_irqrestore(shost->host_lock, flags);
1328
1329 return sdev;
1330}
1331EXPORT_SYMBOL(scsi_device_lookup_by_target);
1332
1333/**
Rob Landleyeb448202007-11-03 13:30:39 -05001334 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 * @shost: SCSI host pointer
1336 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -05001337 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 * @lun: SCSI Logical Unit Number
1339 *
Rob Landleyeb448202007-11-03 13:30:39 -05001340 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1341 * for a given host. The returned scsi_device does not have an additional
1342 * reference. You must hold the host's host_lock over this call and any access
1343 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 *
1345 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001346 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 * really want to use scsi_device_lookup instead.
1348 **/
1349struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001350 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351{
1352 struct scsi_device *sdev;
1353
1354 list_for_each_entry(sdev, &shost->__devices, siblings) {
1355 if (sdev->channel == channel && sdev->id == id &&
1356 sdev->lun ==lun)
1357 return sdev;
1358 }
1359
1360 return NULL;
1361}
1362EXPORT_SYMBOL(__scsi_device_lookup);
1363
1364/**
1365 * scsi_device_lookup - find a device given the host
1366 * @shost: SCSI host pointer
1367 * @channel: SCSI channel (zero if only one channel)
1368 * @id: SCSI target number (physical unit number)
1369 * @lun: SCSI Logical Unit Number
1370 *
Rob Landleyeb448202007-11-03 13:30:39 -05001371 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1372 * for a given host. The returned scsi_device has an additional reference that
1373 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 **/
1375struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001376 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377{
1378 struct scsi_device *sdev;
1379 unsigned long flags;
1380
1381 spin_lock_irqsave(shost->host_lock, flags);
1382 sdev = __scsi_device_lookup(shost, channel, id, lun);
1383 if (sdev && scsi_device_get(sdev))
1384 sdev = NULL;
1385 spin_unlock_irqrestore(shost->host_lock, flags);
1386
1387 return sdev;
1388}
1389EXPORT_SYMBOL(scsi_device_lookup);
1390
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391MODULE_DESCRIPTION("SCSI core");
1392MODULE_LICENSE("GPL");
1393
1394module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1395MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1396
1397static int __init init_scsi(void)
1398{
Jens Axboe9bf09c22006-09-30 20:31:11 +02001399 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400
1401 error = scsi_init_queue();
1402 if (error)
1403 return error;
1404 error = scsi_init_procfs();
1405 if (error)
1406 goto cleanup_queue;
1407 error = scsi_init_devinfo();
1408 if (error)
1409 goto cleanup_procfs;
1410 error = scsi_init_hosts();
1411 if (error)
1412 goto cleanup_devlist;
1413 error = scsi_init_sysctl();
1414 if (error)
1415 goto cleanup_hosts;
1416 error = scsi_sysfs_register();
1417 if (error)
1418 goto cleanup_sysctl;
1419
James Smart84314fd2006-08-18 17:30:09 -04001420 scsi_netlink_init();
1421
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1423 return 0;
1424
1425cleanup_sysctl:
1426 scsi_exit_sysctl();
1427cleanup_hosts:
1428 scsi_exit_hosts();
1429cleanup_devlist:
1430 scsi_exit_devinfo();
1431cleanup_procfs:
1432 scsi_exit_procfs();
1433cleanup_queue:
1434 scsi_exit_queue();
1435 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1436 -error);
1437 return error;
1438}
1439
1440static void __exit exit_scsi(void)
1441{
James Smart84314fd2006-08-18 17:30:09 -04001442 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 scsi_sysfs_unregister();
1444 scsi_exit_sysctl();
1445 scsi_exit_hosts();
1446 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 scsi_exit_procfs();
1448 scsi_exit_queue();
Dan Williamsa4683482012-07-09 19:33:30 -07001449 async_unregister_domain(&scsi_sd_probe_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450}
1451
1452subsys_initcall(init_scsi);
1453module_exit(exit_scsi);