blob: e02885451425dbd4af6272ce53d1b2b54f809a43 [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
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 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200530 * 2: log opcode + command of all commands + cmd address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200532 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 *
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) {
Hannes Reineckec11c0042014-10-24 14:27:01 +0200540 scmd_printk(KERN_INFO, cmd,
541 "Send: scmd 0x%p\n", cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 scsi_print_command(cmd);
543 if (level > 3) {
544 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800545 " queuecommand 0x%p\n",
Boaz Harrosha73e45b2007-07-04 21:26:01 +0300546 scsi_sglist(cmd), scsi_bufflen(cmd),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500547 cmd->device->host->hostt->queuecommand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549 }
550 }
551 }
552}
553
554void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
555{
556 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557
558 /*
559 * If ML COMPLETE log level is greater than or equal to:
560 *
561 * 1: log disposition, result, opcode + command, and conditionally
562 * sense data for failures or non SUCCESS dispositions.
563 *
564 * 2: same as 1 but for all command completions.
565 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200566 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 *
568 * 4: same as 3 plus dump extra junk
569 */
570 if (unlikely(scsi_logging_level)) {
571 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
572 SCSI_LOG_MLCOMPLETE_BITS);
573 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
574 (level > 1)) {
Hannes Reineckec11c0042014-10-24 14:27:01 +0200575 scsi_print_result(cmd, "Done: ", disposition);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500577 if (status_byte(cmd->result) & CHECK_CONDITION)
Hannes Reinecked811b842014-10-24 14:26:45 +0200578 scsi_print_sense(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500579 if (level > 3)
580 scmd_printk(KERN_INFO, cmd,
581 "scsi host busy %d failed %d\n",
Christoph Hellwig74665012014-01-22 15:29:29 +0100582 atomic_read(&cmd->device->host->host_busy),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500583 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 }
585 }
586}
587#endif
588
Rob Landleyeb448202007-11-03 13:30:39 -0500589/**
590 * scsi_cmd_get_serial - Assign a serial number to a command
591 * @host: the scsi host
592 * @cmd: command to assign serial number to
593 *
594 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 * and debugging purposes. Protected by the Host_Lock of host.
596 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500597void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598{
599 cmd->serial_number = host->cmd_serial_number++;
600 if (cmd->serial_number == 0)
601 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
Jeff Garzikf2812332010-11-16 02:10:29 -0500603EXPORT_SYMBOL(scsi_cmd_get_serial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Rob Landleyeb448202007-11-03 13:30:39 -0500605/**
Rob Landleyeb448202007-11-03 13:30:39 -0500606 * scsi_finish_command - cleanup and pass command back to upper layer
607 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 *
Rob Landleyeb448202007-11-03 13:30:39 -0500609 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 * request, waking processes that are waiting on results,
611 * etc.
612 */
613void scsi_finish_command(struct scsi_cmnd *cmd)
614{
615 struct scsi_device *sdev = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500616 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800618 struct scsi_driver *drv;
619 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
621 scsi_device_unbusy(sdev);
622
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100623 /*
624 * Clear the flags that say that the device/target/host is no longer
625 * capable of accepting new commands.
626 */
627 if (atomic_read(&shost->host_blocked))
628 atomic_set(&shost->host_blocked, 0);
629 if (atomic_read(&starget->target_blocked))
630 atomic_set(&starget->target_blocked, 0);
631 if (atomic_read(&sdev->device_blocked))
632 atomic_set(&sdev->device_blocked, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
634 /*
635 * If we have valid sense information, then some kind of recovery
636 * must have taken place. Make a note of this.
637 */
638 if (SCSI_SENSE_VALID(cmd))
639 cmd->result |= (DRIVER_SENSE << 24);
640
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400641 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
642 "Notifying upper driver of completion "
643 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200645 good_bytes = scsi_bufflen(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800646 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
James Bottomley427e59f2008-03-08 18:24:17 -0600647 int old_good_bytes = good_bytes;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800648 drv = scsi_cmd_to_driver(cmd);
649 if (drv->done)
650 good_bytes = drv->done(cmd);
James Bottomley427e59f2008-03-08 18:24:17 -0600651 /*
652 * USB may not give sense identifying bad sector and
653 * simply return a residue instead, so subtract off the
654 * residue if drv->done() error processing indicates no
655 * change to the completion length.
656 */
657 if (good_bytes == old_good_bytes)
658 good_bytes -= scsi_get_resid(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800659 }
660 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
Rob Landleyeb448202007-11-03 13:30:39 -0500663/**
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100664 * scsi_change_queue_depth - change a device's queue depth
Rob Landleyeb448202007-11-03 13:30:39 -0500665 * @sdev: SCSI Device in question
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100666 * @depth: number of commands allowed to be queued to the driver
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 *
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100668 * Sets the device queue depth and returns the new value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 */
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100670int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671{
672 unsigned long flags;
673
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100674 if (depth <= 0)
675 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
678
Mike Christie885ace92008-07-11 19:50:32 -0500679 /*
680 * Check to see if the queue is managed by the block layer.
681 * If it is, and we fail to adjust the depth, exit.
682 *
683 * Do not resize the tag map if it is a host wide share bqt,
684 * because the size should be the hosts's can_queue. If there
685 * is more IO than the LLD's can_queue (so there are not enuogh
686 * tags) request_fn's host queue ready check will handle it.
687 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100688 if (!shost_use_blk_mq(sdev->host) && !sdev->host->bqt) {
Mike Christie885ace92008-07-11 19:50:32 -0500689 if (blk_queue_tagged(sdev->request_queue) &&
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100690 blk_queue_resize_tags(sdev->request_queue, depth) != 0)
691 goto out_unlock;
Mike Christie885ace92008-07-11 19:50:32 -0500692 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100694 sdev->queue_depth = depth;
695out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100697out:
698 return sdev->queue_depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699}
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100700EXPORT_SYMBOL(scsi_change_queue_depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
Rob Landleyeb448202007-11-03 13:30:39 -0500702/**
703 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
704 * @sdev: SCSI Device in question
705 * @depth: Current number of outstanding SCSI commands on this device,
706 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 *
Rob Landleyeb448202007-11-03 13:30:39 -0500708 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 * specific SCSI device to determine if and when there is a
710 * need to adjust the queue depth on the device.
711 *
Rob Landleyeb448202007-11-03 13:30:39 -0500712 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 * -1 - Drop back to untagged operation using host->cmd_per_lun
714 * as the untagged command depth
715 *
716 * Lock Status: None held on entry
717 *
718 * Notes: Low level drivers may call this at any time and we will do
719 * "The Right Thing." We are interrupt context safe.
720 */
721int scsi_track_queue_full(struct scsi_device *sdev, int depth)
722{
Vasu Dev4a840672009-10-22 15:46:33 -0700723
724 /*
725 * Don't let QUEUE_FULLs on the same
726 * jiffies count, they could all be from
727 * same event.
728 */
729 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 return 0;
731
Vasu Dev4a840672009-10-22 15:46:33 -0700732 sdev->last_queue_full_time = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 if (sdev->last_queue_full_depth != depth) {
734 sdev->last_queue_full_count = 1;
735 sdev->last_queue_full_depth = depth;
736 } else {
737 sdev->last_queue_full_count++;
738 }
739
740 if (sdev->last_queue_full_count <= 10)
741 return 0;
Christoph Hellwig609aa222014-10-30 11:54:58 +0100742
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100743 return scsi_change_queue_depth(sdev, depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744}
745EXPORT_SYMBOL(scsi_track_queue_full);
746
747/**
Matthew Wilcox881a2562008-12-31 13:12:46 -0500748 * scsi_vpd_inquiry - Request a device provide us with a VPD page
749 * @sdev: The device to ask
750 * @buffer: Where to put the result
751 * @page: Which Vital Product Data to return
752 * @len: The length of the buffer
753 *
754 * This is an internal helper function. You probably want to use
755 * scsi_get_vpd_page instead.
756 *
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100757 * Returns size of the vpd page on success or a negative error number.
Matthew Wilcox881a2562008-12-31 13:12:46 -0500758 */
759static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
760 u8 page, unsigned len)
761{
762 int result;
763 unsigned char cmd[16];
764
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100765 if (len < 4)
766 return -EINVAL;
767
Matthew Wilcox881a2562008-12-31 13:12:46 -0500768 cmd[0] = INQUIRY;
769 cmd[1] = 1; /* EVPD */
770 cmd[2] = page;
771 cmd[3] = len >> 8;
772 cmd[4] = len & 0xff;
773 cmd[5] = 0; /* Control byte */
774
775 /*
776 * I'm not convinced we need to try quite this hard to get VPD, but
777 * all the existing users tried this hard.
778 */
779 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
James Bottomley95a36392009-08-11 10:59:09 -0500780 len, NULL, 30 * HZ, 3, NULL);
Matthew Wilcox881a2562008-12-31 13:12:46 -0500781 if (result)
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100782 return -EIO;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500783
784 /* Sanity check that we got the page back that we asked for */
785 if (buffer[1] != page)
786 return -EIO;
787
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100788 return get_unaligned_be16(&buffer[2]) + 4;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500789}
790
791/**
792 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
793 * @sdev: The device to ask
794 * @page: Which Vital Product Data to return
Randy Dunlap786f8ba2010-02-28 17:32:45 -0800795 * @buf: where to store the VPD
796 * @buf_len: number of bytes in the VPD buffer area
Matthew Wilcox881a2562008-12-31 13:12:46 -0500797 *
798 * SCSI devices may optionally supply Vital Product Data. Each 'page'
799 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
800 * If the device supports this VPD page, this routine returns a pointer
801 * to a buffer containing the data from that page. The caller is
802 * responsible for calling kfree() on this pointer when it is no longer
803 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
804 */
James Bottomleye3deec02009-11-03 12:33:07 -0600805int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
806 int buf_len)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500807{
808 int i, result;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500809
Martin K. Petersen75625232013-07-30 22:58:34 -0400810 if (sdev->skip_vpd_pages)
811 goto fail;
812
Matthew Wilcox881a2562008-12-31 13:12:46 -0500813 /* Ask for all the pages supported by this device */
James Bottomleye3deec02009-11-03 12:33:07 -0600814 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100815 if (result < 4)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500816 goto fail;
817
818 /* If the user actually wanted this page, we can skip the rest */
819 if (page == 0)
Martin K. Petersen16d3ea22010-09-10 01:20:27 -0400820 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500821
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100822 for (i = 4; i < min(result, buf_len); i++)
823 if (buf[i] == page)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500824 goto found;
James Bottomleye3deec02009-11-03 12:33:07 -0600825
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100826 if (i < result && i >= buf_len)
James Bottomleye3deec02009-11-03 12:33:07 -0600827 /* ran off the end of the buffer, give us benefit of doubt */
828 goto found;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500829 /* The device claims it doesn't support the requested page */
830 goto fail;
831
832 found:
James Bottomleye3deec02009-11-03 12:33:07 -0600833 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100834 if (result < 0)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500835 goto fail;
836
James Bottomleye3deec02009-11-03 12:33:07 -0600837 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500838
839 fail:
James Bottomleye3deec02009-11-03 12:33:07 -0600840 return -EINVAL;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500841}
842EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
843
844/**
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100845 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
846 * @sdev: The device to ask
847 *
848 * Attach the 'Device Identification' VPD page (0x83) and the
849 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
850 * structure. This information can be used to identify the device
851 * uniquely.
852 */
853void scsi_attach_vpd(struct scsi_device *sdev)
854{
855 int result, i;
856 int vpd_len = SCSI_VPD_PG_LEN;
857 int pg80_supported = 0;
858 int pg83_supported = 0;
859 unsigned char *vpd_buf;
860
861 if (sdev->skip_vpd_pages)
862 return;
863retry_pg0:
864 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
865 if (!vpd_buf)
866 return;
867
868 /* Ask for all the pages supported by this device */
869 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
870 if (result < 0) {
871 kfree(vpd_buf);
872 return;
873 }
874 if (result > vpd_len) {
875 vpd_len = result;
876 kfree(vpd_buf);
877 goto retry_pg0;
878 }
879
880 for (i = 4; i < result; i++) {
881 if (vpd_buf[i] == 0x80)
882 pg80_supported = 1;
883 if (vpd_buf[i] == 0x83)
884 pg83_supported = 1;
885 }
886 kfree(vpd_buf);
887 vpd_len = SCSI_VPD_PG_LEN;
888
889 if (pg80_supported) {
890retry_pg80:
891 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
892 if (!vpd_buf)
893 return;
894
895 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
896 if (result < 0) {
897 kfree(vpd_buf);
898 return;
899 }
900 if (result > vpd_len) {
901 vpd_len = result;
902 kfree(vpd_buf);
903 goto retry_pg80;
904 }
905 sdev->vpd_pg80_len = result;
906 sdev->vpd_pg80 = vpd_buf;
907 vpd_len = SCSI_VPD_PG_LEN;
908 }
909
910 if (pg83_supported) {
911retry_pg83:
912 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
913 if (!vpd_buf)
914 return;
915
916 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
917 if (result < 0) {
918 kfree(vpd_buf);
919 return;
920 }
921 if (result > vpd_len) {
922 vpd_len = result;
923 kfree(vpd_buf);
924 goto retry_pg83;
925 }
926 sdev->vpd_pg83_len = result;
927 sdev->vpd_pg83 = vpd_buf;
928 }
929}
930
931/**
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400932 * scsi_report_opcode - Find out if a given command opcode is supported
933 * @sdev: scsi device to query
934 * @buffer: scratch buffer (must be at least 20 bytes long)
935 * @len: length of buffer
936 * @opcode: opcode for command to look up
937 *
938 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400939 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
940 * unsupported and 1 if the device claims to support the command.
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400941 */
942int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
943 unsigned int len, unsigned char opcode)
944{
945 unsigned char cmd[16];
946 struct scsi_sense_hdr sshdr;
947 int result;
948
949 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400950 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400951
952 memset(cmd, 0, 16);
953 cmd[0] = MAINTENANCE_IN;
954 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
955 cmd[2] = 1; /* One command format */
956 cmd[3] = opcode;
957 put_unaligned_be32(len, &cmd[6]);
958 memset(buffer, 0, len);
959
960 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
961 &sshdr, 30 * HZ, 3, NULL);
962
963 if (result && scsi_sense_valid(&sshdr) &&
964 sshdr.sense_key == ILLEGAL_REQUEST &&
965 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400966 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400967
968 if ((buffer[1] & 3) == 3) /* Command supported */
969 return 1;
970
971 return 0;
972}
973EXPORT_SYMBOL(scsi_report_opcode);
974
975/**
Rob Landleyeb448202007-11-03 13:30:39 -0500976 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 * @sdev: device to get a reference to
978 *
Rob Landleyeb448202007-11-03 13:30:39 -0500979 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 * of the underlying LLDD module. You must hold host_lock of the
981 * parent Scsi_Host or already have a reference when calling this.
982 */
983int scsi_device_get(struct scsi_device *sdev)
984{
James Bottomley85b6c722006-08-31 18:15:22 -0400985 if (sdev->sdev_state == SDEV_DEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 return -ENXIO;
987 if (!get_device(&sdev->sdev_gendev))
988 return -ENXIO;
James Bottomley85b6c722006-08-31 18:15:22 -0400989 /* We can fail this if we're doing SCSI operations
990 * from module exit (like cache flush) */
991 try_module_get(sdev->host->hostt->module);
992
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 return 0;
994}
995EXPORT_SYMBOL(scsi_device_get);
996
997/**
998 * scsi_device_put - release a reference to a scsi_device
999 * @sdev: device to release a reference on.
1000 *
Rob Landleyeb448202007-11-03 13:30:39 -05001001 * Description: Release a reference to the scsi_device and decrements the use
1002 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 * user vanishes.
1004 */
1005void scsi_device_put(struct scsi_device *sdev)
1006{
Ingo Molnar504fb372006-11-09 10:09:35 +01001007#ifdef CONFIG_MODULE_UNLOAD
James Bottomleyf479ab82006-09-06 09:00:29 -05001008 struct module *module = sdev->host->hostt->module;
1009
James Bottomley85b6c722006-08-31 18:15:22 -04001010 /* The module refcount will be zero if scsi_device_get()
1011 * was called from a module removal routine */
James Bottomleyf479ab82006-09-06 09:00:29 -05001012 if (module && module_refcount(module) != 0)
1013 module_put(module);
Daniel Walkera506b442006-09-09 09:31:03 -07001014#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 put_device(&sdev->sdev_gendev);
1016}
1017EXPORT_SYMBOL(scsi_device_put);
1018
Rob Landleyeb448202007-11-03 13:30:39 -05001019/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1021 struct scsi_device *prev)
1022{
1023 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1024 struct scsi_device *next = NULL;
1025 unsigned long flags;
1026
1027 spin_lock_irqsave(shost->host_lock, flags);
1028 while (list->next != &shost->__devices) {
1029 next = list_entry(list->next, struct scsi_device, siblings);
1030 /* skip devices that we can't get a reference to */
1031 if (!scsi_device_get(next))
1032 break;
1033 next = NULL;
1034 list = list->next;
1035 }
1036 spin_unlock_irqrestore(shost->host_lock, flags);
1037
1038 if (prev)
1039 scsi_device_put(prev);
1040 return next;
1041}
1042EXPORT_SYMBOL(__scsi_iterate_devices);
1043
1044/**
1045 * starget_for_each_device - helper to walk all devices of a target
1046 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -05001047 * @data: Opaque passed to each function call.
1048 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001050 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 * a reference that must be released by scsi_host_put when breaking
1052 * out of the loop.
1053 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001054void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 void (*fn)(struct scsi_device *, void *))
1056{
1057 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1058 struct scsi_device *sdev;
1059
1060 shost_for_each_device(sdev, shost) {
1061 if ((sdev->channel == starget->channel) &&
1062 (sdev->id == starget->id))
1063 fn(sdev, data);
1064 }
1065}
1066EXPORT_SYMBOL(starget_for_each_device);
1067
1068/**
Randy Dunlap14f501a2008-02-03 15:06:36 -08001069 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001070 * @starget: target whose devices we want to iterate over.
Randy Dunlap14f501a2008-02-03 15:06:36 -08001071 * @data: parameter for callback @fn()
1072 * @fn: callback function that is invoked for each device
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001073 *
1074 * This traverses over each device of @starget. It does _not_
1075 * take a reference on the scsi_device, so the whole loop must be
1076 * protected by shost->host_lock.
1077 *
1078 * Note: The only reason why drivers would want to use this is because
1079 * they need to access the device list in irq context. Otherwise you
1080 * really want to use starget_for_each_device instead.
1081 **/
1082void __starget_for_each_device(struct scsi_target *starget, void *data,
1083 void (*fn)(struct scsi_device *, void *))
1084{
1085 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1086 struct scsi_device *sdev;
1087
1088 __shost_for_each_device(sdev, shost) {
1089 if ((sdev->channel == starget->channel) &&
1090 (sdev->id == starget->id))
1091 fn(sdev, data);
1092 }
1093}
1094EXPORT_SYMBOL(__starget_for_each_device);
1095
1096/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1098 * @starget: SCSI target pointer
1099 * @lun: SCSI Logical Unit Number
1100 *
Rob Landleyeb448202007-11-03 13:30:39 -05001101 * Description: Looks up the scsi_device with the specified @lun for a given
1102 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 * reference. You must hold the host's host_lock over this call and
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001104 * any access to the returned scsi_device. A scsi_device in state
1105 * SDEV_DEL is skipped.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -08001107 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001108 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 * really want to use scsi_device_lookup_by_target instead.
1110 **/
1111struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001112 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113{
1114 struct scsi_device *sdev;
1115
1116 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001117 if (sdev->sdev_state == SDEV_DEL)
1118 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 if (sdev->lun ==lun)
1120 return sdev;
1121 }
1122
1123 return NULL;
1124}
1125EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1126
1127/**
1128 * scsi_device_lookup_by_target - find a device given the target
1129 * @starget: SCSI target pointer
1130 * @lun: SCSI Logical Unit Number
1131 *
Bartlomiej Zolnierkiewicz477e6082009-04-27 20:54:22 +02001132 * Description: Looks up the scsi_device with the specified @lun for a given
1133 * @starget. The returned scsi_device has an additional reference that
Rob Landleyeb448202007-11-03 13:30:39 -05001134 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 **/
1136struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001137 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138{
1139 struct scsi_device *sdev;
1140 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1141 unsigned long flags;
1142
1143 spin_lock_irqsave(shost->host_lock, flags);
1144 sdev = __scsi_device_lookup_by_target(starget, lun);
1145 if (sdev && scsi_device_get(sdev))
1146 sdev = NULL;
1147 spin_unlock_irqrestore(shost->host_lock, flags);
1148
1149 return sdev;
1150}
1151EXPORT_SYMBOL(scsi_device_lookup_by_target);
1152
1153/**
Rob Landleyeb448202007-11-03 13:30:39 -05001154 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 * @shost: SCSI host pointer
1156 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -05001157 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 * @lun: SCSI Logical Unit Number
1159 *
Rob Landleyeb448202007-11-03 13:30:39 -05001160 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1161 * for a given host. The returned scsi_device does not have an additional
1162 * reference. You must hold the host's host_lock over this call and any access
1163 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 *
1165 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001166 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 * really want to use scsi_device_lookup instead.
1168 **/
1169struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001170 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171{
1172 struct scsi_device *sdev;
1173
1174 list_for_each_entry(sdev, &shost->__devices, siblings) {
1175 if (sdev->channel == channel && sdev->id == id &&
1176 sdev->lun ==lun)
1177 return sdev;
1178 }
1179
1180 return NULL;
1181}
1182EXPORT_SYMBOL(__scsi_device_lookup);
1183
1184/**
1185 * scsi_device_lookup - find a device given the host
1186 * @shost: SCSI host pointer
1187 * @channel: SCSI channel (zero if only one channel)
1188 * @id: SCSI target number (physical unit number)
1189 * @lun: SCSI Logical Unit Number
1190 *
Rob Landleyeb448202007-11-03 13:30:39 -05001191 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1192 * for a given host. The returned scsi_device has an additional reference that
1193 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 **/
1195struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001196 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197{
1198 struct scsi_device *sdev;
1199 unsigned long flags;
1200
1201 spin_lock_irqsave(shost->host_lock, flags);
1202 sdev = __scsi_device_lookup(shost, channel, id, lun);
1203 if (sdev && scsi_device_get(sdev))
1204 sdev = NULL;
1205 spin_unlock_irqrestore(shost->host_lock, flags);
1206
1207 return sdev;
1208}
1209EXPORT_SYMBOL(scsi_device_lookup);
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211MODULE_DESCRIPTION("SCSI core");
1212MODULE_LICENSE("GPL");
1213
1214module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1215MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1216
Christoph Hellwig24c20f12014-09-30 16:43:46 +02001217#ifdef CONFIG_SCSI_MQ_DEFAULT
1218bool scsi_use_blk_mq = true;
1219#else
Christoph Hellwigd2852032014-01-17 12:06:53 +01001220bool scsi_use_blk_mq = false;
Christoph Hellwig24c20f12014-09-30 16:43:46 +02001221#endif
Christoph Hellwigd2852032014-01-17 12:06:53 +01001222module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
1223
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224static int __init init_scsi(void)
1225{
Jens Axboe9bf09c22006-09-30 20:31:11 +02001226 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
1228 error = scsi_init_queue();
1229 if (error)
1230 return error;
1231 error = scsi_init_procfs();
1232 if (error)
1233 goto cleanup_queue;
1234 error = scsi_init_devinfo();
1235 if (error)
1236 goto cleanup_procfs;
1237 error = scsi_init_hosts();
1238 if (error)
1239 goto cleanup_devlist;
1240 error = scsi_init_sysctl();
1241 if (error)
1242 goto cleanup_hosts;
1243 error = scsi_sysfs_register();
1244 if (error)
1245 goto cleanup_sysctl;
1246
James Smart84314fd2006-08-18 17:30:09 -04001247 scsi_netlink_init();
1248
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1250 return 0;
1251
1252cleanup_sysctl:
1253 scsi_exit_sysctl();
1254cleanup_hosts:
1255 scsi_exit_hosts();
1256cleanup_devlist:
1257 scsi_exit_devinfo();
1258cleanup_procfs:
1259 scsi_exit_procfs();
1260cleanup_queue:
1261 scsi_exit_queue();
1262 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1263 -error);
1264 return error;
1265}
1266
1267static void __exit exit_scsi(void)
1268{
James Smart84314fd2006-08-18 17:30:09 -04001269 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 scsi_sysfs_unregister();
1271 scsi_exit_sysctl();
1272 scsi_exit_hosts();
1273 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 scsi_exit_procfs();
1275 scsi_exit_queue();
Dan Williamsa4683482012-07-09 19:33:30 -07001276 async_unregister_domain(&scsi_sd_probe_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277}
1278
1279subsys_initcall(init_scsi);
1280module_exit(exit_scsi);