blob: 1f36aca44394eaf49a8edc0ce78d6db371288cc8 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101struct scsi_host_cmd_pool {
James Bottomley5b7f1682008-01-20 09:28:24 -0600102 struct kmem_cache *cmd_slab;
103 struct kmem_cache *sense_slab;
104 unsigned int users;
105 char *cmd_name;
106 char *sense_name;
107 unsigned int slab_flags;
108 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109};
110
111static struct scsi_host_cmd_pool scsi_cmd_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600112 .cmd_name = "scsi_cmd_cache",
113 .sense_name = "scsi_sense_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 .slab_flags = SLAB_HWCACHE_ALIGN,
115};
116
117static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600118 .cmd_name = "scsi_cmd_cache(DMA)",
119 .sense_name = "scsi_sense_cache(DMA)",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
121 .gfp_mask = __GFP_DMA,
122};
123
Arjan van de Ven0b950672006-01-11 13:16:10 +0100124static DEFINE_MUTEX(host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Rob Landleyeb448202007-11-03 13:30:39 -0500126/**
Christoph Hellwig7c283342014-02-20 14:21:00 -0800127 * scsi_host_free_command - internal function to release a command
128 * @shost: host to free the command for
James Bottomleye507e302008-03-13 11:16:33 -0500129 * @cmd: command to release
130 *
131 * the command must previously have been allocated by
Christoph Hellwig7c283342014-02-20 14:21:00 -0800132 * scsi_host_alloc_command.
James Bottomleye507e302008-03-13 11:16:33 -0500133 */
134static void
Christoph Hellwig7c283342014-02-20 14:21:00 -0800135scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
James Bottomleye507e302008-03-13 11:16:33 -0500136{
Christoph Hellwig7c283342014-02-20 14:21:00 -0800137 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
138
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400139 if (cmd->prot_sdb)
140 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
James Bottomleye507e302008-03-13 11:16:33 -0500141 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
142 kmem_cache_free(pool->cmd_slab, cmd);
143}
144
145/**
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400146 * scsi_host_alloc_command - internal function to allocate command
147 * @shost: SCSI host whose pool to allocate from
148 * @gfp_mask: mask for the allocation
149 *
150 * Returns a fully allocated command with sense buffer and protection
151 * data buffer (where applicable) or NULL on failure
152 */
153static struct scsi_cmnd *
154scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
155{
Christoph Hellwig7c283342014-02-20 14:21:00 -0800156 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400157 struct scsi_cmnd *cmd;
158
Christoph Hellwig7c283342014-02-20 14:21:00 -0800159 cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400160 if (!cmd)
Christoph Hellwig7c283342014-02-20 14:21:00 -0800161 goto fail;
162
163 cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
164 gfp_mask | pool->gfp_mask);
165 if (!cmd->sense_buffer)
166 goto fail_free_cmd;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400167
168 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
169 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
Christoph Hellwig7c283342014-02-20 14:21:00 -0800170 if (!cmd->prot_sdb)
171 goto fail_free_sense;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400172 }
173
174 return cmd;
Christoph Hellwig7c283342014-02-20 14:21:00 -0800175
176fail_free_sense:
177 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
178fail_free_cmd:
179 kmem_cache_free(pool->cmd_slab, cmd);
180fail:
181 return NULL;
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400182}
183
184/**
Rob Landleyeb448202007-11-03 13:30:39 -0500185 * __scsi_get_command - Allocate a struct scsi_cmnd
186 * @shost: host to transmit command
187 * @gfp_mask: allocation mask
188 *
189 * Description: allocate a struct scsi_cmd from host's slab, recycling from the
190 * host's free_list if necessary.
191 */
Christoph Hellwigf1bea552014-04-15 12:26:54 +0200192static struct scsi_cmnd *
193__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400195 struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
Hugh Dickins164fc5d2008-04-06 23:56:57 +0100196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 if (unlikely(!cmd)) {
198 unsigned long flags;
199
200 spin_lock_irqsave(&shost->free_list_lock, flags);
201 if (likely(!list_empty(&shost->free_list))) {
202 cmd = list_entry(shost->free_list.next,
203 struct scsi_cmnd, list);
204 list_del_init(&cmd->list);
205 }
206 spin_unlock_irqrestore(&shost->free_list_lock, flags);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900207
208 if (cmd) {
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400209 void *buf, *prot;
210
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900211 buf = cmd->sense_buffer;
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400212 prot = cmd->prot_sdb;
213
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900214 memset(cmd, 0, sizeof(*cmd));
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400215
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900216 cmd->sense_buffer = buf;
Martin K. Petersenb4c25542009-09-18 17:33:01 -0400217 cmd->prot_sdb = prot;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900218 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 }
220
221 return cmd;
222}
223
Rob Landleyeb448202007-11-03 13:30:39 -0500224/**
225 * scsi_get_command - Allocate and setup a scsi command block
226 * @dev: parent scsi device
227 * @gfp_mask: allocator flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 *
229 * Returns: The allocated scsi command structure.
230 */
Al Viroc53033f2005-10-21 03:22:08 -0400231struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232{
Christoph Hellwig04796332014-02-20 14:20:55 -0800233 struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
234 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Christoph Hellwig04796332014-02-20 14:20:55 -0800236 if (unlikely(cmd == NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 return NULL;
238
Christoph Hellwig04796332014-02-20 14:20:55 -0800239 cmd->device = dev;
240 INIT_LIST_HEAD(&cmd->list);
241 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
242 spin_lock_irqsave(&dev->list_lock, flags);
243 list_add_tail(&cmd->list, &dev->cmd_list);
244 spin_unlock_irqrestore(&dev->list_lock, flags);
245 cmd->jiffies_at_alloc = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 return cmd;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900247}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
Rob Landleyeb448202007-11-03 13:30:39 -0500249/**
250 * __scsi_put_command - Free a struct scsi_cmnd
251 * @shost: dev->host
252 * @cmd: Command to free
Rob Landleyeb448202007-11-03 13:30:39 -0500253 */
Christoph Hellwigf1bea552014-04-15 12:26:54 +0200254static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900255{
256 unsigned long flags;
257
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900258 if (unlikely(list_empty(&shost->free_list))) {
Christoph Hellwig44b93b52014-02-20 14:20:53 -0800259 spin_lock_irqsave(&shost->free_list_lock, flags);
260 if (list_empty(&shost->free_list)) {
261 list_add(&cmd->list, &shost->free_list);
262 cmd = NULL;
263 }
264 spin_unlock_irqrestore(&shost->free_list_lock, flags);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900265 }
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900266
James Bottomleye507e302008-03-13 11:16:33 -0500267 if (likely(cmd != NULL))
Christoph Hellwig7c283342014-02-20 14:21:00 -0800268 scsi_host_free_command(shost, cmd);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900269}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900270
Rob Landleyeb448202007-11-03 13:30:39 -0500271/**
272 * scsi_put_command - Free a scsi command block
273 * @cmd: command block to free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 *
275 * Returns: Nothing.
276 *
277 * Notes: The command must not belong to any lists.
278 */
279void scsi_put_command(struct scsi_cmnd *cmd)
280{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 unsigned long flags;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900282
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 /* serious error if the command hasn't come from a device list */
284 spin_lock_irqsave(&cmd->device->list_lock, flags);
285 BUG_ON(list_empty(&cmd->list));
286 list_del_init(&cmd->list);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900287 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
Bart Van Asschefcc95a72014-06-02 11:50:52 +0200289 BUG_ON(delayed_work_pending(&cmd->abort_work));
Hannes Reineckee494f6a2013-11-11 13:44:54 +0100290
Christoph Hellwig04796332014-02-20 14:20:55 -0800291 __scsi_put_command(cmd->device->host, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800294static struct scsi_host_cmd_pool *
295scsi_find_host_cmd_pool(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296{
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800297 if (shost->hostt->cmd_size)
298 return shost->hostt->cmd_pool;
299 if (shost->unchecked_isa_dma)
300 return &scsi_cmd_dma_pool;
301 return &scsi_cmd_pool;
302}
303
304static void
305scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
306{
307 kfree(pool->sense_name);
308 kfree(pool->cmd_name);
309 kfree(pool);
310}
311
312static struct scsi_host_cmd_pool *
313scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
314{
315 struct scsi_host_template *hostt = shost->hostt;
316 struct scsi_host_cmd_pool *pool;
317
318 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
319 if (!pool)
320 return NULL;
321
James Bottomley884ffee2014-07-26 12:21:26 -0400322 pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name);
323 pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->proc_name);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800324 if (!pool->cmd_name || !pool->sense_name) {
325 scsi_free_host_cmd_pool(pool);
326 return NULL;
327 }
328
329 pool->slab_flags = SLAB_HWCACHE_ALIGN;
330 if (shost->unchecked_isa_dma) {
331 pool->slab_flags |= SLAB_CACHE_DMA;
332 pool->gfp_mask = __GFP_DMA;
333 }
Juergen Grossf6105c02014-08-04 13:30:02 +0200334
335 if (hostt->cmd_size)
336 hostt->cmd_pool = pool;
337
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800338 return pool;
339}
340
341static struct scsi_host_cmd_pool *
342scsi_get_host_cmd_pool(struct Scsi_Host *shost)
343{
344 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500345 struct scsi_host_cmd_pool *retval = NULL, *pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800346 size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
347
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 /*
349 * Select a command slab for this host and create it if not
Rob Landleyeb448202007-11-03 13:30:39 -0500350 * yet existent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 */
Arjan van de Ven0b950672006-01-11 13:16:10 +0100352 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800353 pool = scsi_find_host_cmd_pool(shost);
354 if (!pool) {
355 pool = scsi_alloc_host_cmd_pool(shost);
356 if (!pool)
357 goto out;
358 }
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 if (!pool->users) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800361 pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
James Bottomley5b7f1682008-01-20 09:28:24 -0600362 pool->slab_flags, NULL);
363 if (!pool->cmd_slab)
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800364 goto out_free_pool;
James Bottomley5b7f1682008-01-20 09:28:24 -0600365
366 pool->sense_slab = kmem_cache_create(pool->sense_name,
367 SCSI_SENSE_BUFFERSIZE, 0,
368 pool->slab_flags, NULL);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800369 if (!pool->sense_slab)
370 goto out_free_slab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 }
372
373 pool->users++;
James Bottomley1c353f72008-03-13 11:19:36 -0500374 retval = pool;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800375out:
Arjan van de Ven0b950672006-01-11 13:16:10 +0100376 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500377 return retval;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800378
379out_free_slab:
380 kmem_cache_destroy(pool->cmd_slab);
381out_free_pool:
Juergen Grossf6105c02014-08-04 13:30:02 +0200382 if (hostt->cmd_size) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800383 scsi_free_host_cmd_pool(pool);
Juergen Grossf6105c02014-08-04 13:30:02 +0200384 hostt->cmd_pool = NULL;
385 }
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800386 goto out;
James Bottomley1c353f72008-03-13 11:19:36 -0500387}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800389static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
James Bottomley1c353f72008-03-13 11:19:36 -0500390{
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800391 struct scsi_host_template *hostt = shost->hostt;
James Bottomley1c353f72008-03-13 11:19:36 -0500392 struct scsi_host_cmd_pool *pool;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900393
FUJITA Tomonori166a7282008-01-08 07:59:05 +0900394 mutex_lock(&host_cmd_pool_mutex);
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800395 pool = scsi_find_host_cmd_pool(shost);
396
James Bottomley1c353f72008-03-13 11:19:36 -0500397 /*
398 * This may happen if a driver has a mismatched get and put
399 * of the command pool; the driver should be implicated in
400 * the stack trace
401 */
402 BUG_ON(pool->users == 0);
403
James Bottomley5b7f1682008-01-20 09:28:24 -0600404 if (!--pool->users) {
405 kmem_cache_destroy(pool->cmd_slab);
406 kmem_cache_destroy(pool->sense_slab);
Juergen Grossf6105c02014-08-04 13:30:02 +0200407 if (hostt->cmd_size) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800408 scsi_free_host_cmd_pool(pool);
Juergen Grossf6105c02014-08-04 13:30:02 +0200409 hostt->cmd_pool = NULL;
410 }
James Bottomley5b7f1682008-01-20 09:28:24 -0600411 }
Arjan van de Ven0b950672006-01-11 13:16:10 +0100412 mutex_unlock(&host_cmd_pool_mutex);
James Bottomley1c353f72008-03-13 11:19:36 -0500413}
414
415/**
James Bottomley1c353f72008-03-13 11:19:36 -0500416 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
417 * @shost: host to allocate the freelist for.
418 *
419 * Description: The command freelist protects against system-wide out of memory
420 * deadlock by preallocating one SCSI command structure for each host, so the
421 * system can always write to a swap file on a device associated with that host.
422 *
423 * Returns: Nothing.
424 */
425int scsi_setup_command_freelist(struct Scsi_Host *shost)
426{
James Bottomley1c353f72008-03-13 11:19:36 -0500427 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800428 struct scsi_cmnd *cmd;
James Bottomley1c353f72008-03-13 11:19:36 -0500429
430 spin_lock_init(&shost->free_list_lock);
431 INIT_LIST_HEAD(&shost->free_list);
432
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800433 shost->cmd_pool = scsi_get_host_cmd_pool(shost);
James Bottomley1c353f72008-03-13 11:19:36 -0500434 if (!shost->cmd_pool)
435 return -ENOMEM;
436
437 /*
438 * Get one backup command for this host.
439 */
Martin K. Petersen7027ad72008-07-17 17:08:48 -0400440 cmd = scsi_host_alloc_command(shost, gfp_mask);
James Bottomley1c353f72008-03-13 11:19:36 -0500441 if (!cmd) {
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800442 scsi_put_host_cmd_pool(shost);
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400443 shost->cmd_pool = NULL;
James Bottomley1c353f72008-03-13 11:19:36 -0500444 return -ENOMEM;
445 }
446 list_add(&cmd->list, &shost->free_list);
447 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448}
449
Rob Landleyeb448202007-11-03 13:30:39 -0500450/**
451 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
452 * @shost: host whose freelist is going to be destroyed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 */
454void scsi_destroy_command_freelist(struct Scsi_Host *shost)
455{
Alan D. Brunelle61d74162008-04-29 16:12:51 -0400456 /*
457 * If cmd_pool is NULL the free list was not initialized, so
458 * do not attempt to release resources.
459 */
460 if (!shost->cmd_pool)
461 return;
462
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 while (!list_empty(&shost->free_list)) {
464 struct scsi_cmnd *cmd;
465
466 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
467 list_del_init(&cmd->list);
Christoph Hellwig7c283342014-02-20 14:21:00 -0800468 scsi_host_free_command(shost, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 }
James Bottomley1c353f72008-03-13 11:19:36 -0500470 shost->cmd_pool = NULL;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800471 scsi_put_host_cmd_pool(shost);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900472}
473
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474#ifdef CONFIG_SCSI_LOGGING
475void scsi_log_send(struct scsi_cmnd *cmd)
476{
477 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
479 /*
480 * If ML QUEUE log level is greater than or equal to:
481 *
482 * 1: nothing (match completion)
483 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200484 * 2: log opcode + command of all commands + cmd address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200486 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 *
Hannes Reineckea4a6afb2015-01-08 07:43:49 +0100488 * 4: same as 3
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 */
490 if (unlikely(scsi_logging_level)) {
491 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
492 SCSI_LOG_MLQUEUE_BITS);
493 if (level > 1) {
Hannes Reineckec11c0042014-10-24 14:27:01 +0200494 scmd_printk(KERN_INFO, cmd,
495 "Send: scmd 0x%p\n", cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 scsi_print_command(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 }
498 }
499}
500
501void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
502{
503 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
505 /*
506 * If ML COMPLETE log level is greater than or equal to:
507 *
508 * 1: log disposition, result, opcode + command, and conditionally
509 * sense data for failures or non SUCCESS dispositions.
510 *
511 * 2: same as 1 but for all command completions.
512 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200513 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 *
515 * 4: same as 3 plus dump extra junk
516 */
517 if (unlikely(scsi_logging_level)) {
518 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
519 SCSI_LOG_MLCOMPLETE_BITS);
520 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
521 (level > 1)) {
Hannes Reinecke026f8da2015-01-08 07:43:47 +0100522 scsi_print_result(cmd, "Done", disposition);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500524 if (status_byte(cmd->result) & CHECK_CONDITION)
Hannes Reinecked811b842014-10-24 14:26:45 +0200525 scsi_print_sense(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500526 if (level > 3)
527 scmd_printk(KERN_INFO, cmd,
528 "scsi host busy %d failed %d\n",
Christoph Hellwig74665012014-01-22 15:29:29 +0100529 atomic_read(&cmd->device->host->host_busy),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500530 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 }
532 }
533}
534#endif
535
Rob Landleyeb448202007-11-03 13:30:39 -0500536/**
537 * scsi_cmd_get_serial - Assign a serial number to a command
538 * @host: the scsi host
539 * @cmd: command to assign serial number to
540 *
541 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 * and debugging purposes. Protected by the Host_Lock of host.
543 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500544void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545{
546 cmd->serial_number = host->cmd_serial_number++;
547 if (cmd->serial_number == 0)
548 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549}
Jeff Garzikf2812332010-11-16 02:10:29 -0500550EXPORT_SYMBOL(scsi_cmd_get_serial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
Rob Landleyeb448202007-11-03 13:30:39 -0500552/**
Rob Landleyeb448202007-11-03 13:30:39 -0500553 * scsi_finish_command - cleanup and pass command back to upper layer
554 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 *
Rob Landleyeb448202007-11-03 13:30:39 -0500556 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 * request, waking processes that are waiting on results,
558 * etc.
559 */
560void scsi_finish_command(struct scsi_cmnd *cmd)
561{
562 struct scsi_device *sdev = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500563 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800565 struct scsi_driver *drv;
566 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 scsi_device_unbusy(sdev);
569
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100570 /*
571 * Clear the flags that say that the device/target/host is no longer
572 * capable of accepting new commands.
573 */
574 if (atomic_read(&shost->host_blocked))
575 atomic_set(&shost->host_blocked, 0);
576 if (atomic_read(&starget->target_blocked))
577 atomic_set(&starget->target_blocked, 0);
578 if (atomic_read(&sdev->device_blocked))
579 atomic_set(&sdev->device_blocked, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581 /*
582 * If we have valid sense information, then some kind of recovery
583 * must have taken place. Make a note of this.
584 */
585 if (SCSI_SENSE_VALID(cmd))
586 cmd->result |= (DRIVER_SENSE << 24);
587
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400588 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
589 "Notifying upper driver of completion "
590 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200592 good_bytes = scsi_bufflen(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800593 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
James Bottomley427e59f2008-03-08 18:24:17 -0600594 int old_good_bytes = good_bytes;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800595 drv = scsi_cmd_to_driver(cmd);
596 if (drv->done)
597 good_bytes = drv->done(cmd);
James Bottomley427e59f2008-03-08 18:24:17 -0600598 /*
599 * USB may not give sense identifying bad sector and
600 * simply return a residue instead, so subtract off the
601 * residue if drv->done() error processing indicates no
602 * change to the completion length.
603 */
604 if (good_bytes == old_good_bytes)
605 good_bytes -= scsi_get_resid(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800606 }
607 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
Rob Landleyeb448202007-11-03 13:30:39 -0500610/**
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100611 * scsi_change_queue_depth - change a device's queue depth
Rob Landleyeb448202007-11-03 13:30:39 -0500612 * @sdev: SCSI Device in question
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100613 * @depth: number of commands allowed to be queued to the driver
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 *
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100615 * Sets the device queue depth and returns the new value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 */
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100617int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618{
Christoph Hellwig64d513a2015-10-08 09:28:04 +0100619 if (depth > 0) {
620 sdev->queue_depth = depth;
621 wmb();
Mike Christie885ace92008-07-11 19:50:32 -0500622 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100624 return sdev->queue_depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625}
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100626EXPORT_SYMBOL(scsi_change_queue_depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Rob Landleyeb448202007-11-03 13:30:39 -0500628/**
629 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
630 * @sdev: SCSI Device in question
631 * @depth: Current number of outstanding SCSI commands on this device,
632 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 *
Rob Landleyeb448202007-11-03 13:30:39 -0500634 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 * specific SCSI device to determine if and when there is a
636 * need to adjust the queue depth on the device.
637 *
Rob Landleyeb448202007-11-03 13:30:39 -0500638 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 * -1 - Drop back to untagged operation using host->cmd_per_lun
640 * as the untagged command depth
641 *
642 * Lock Status: None held on entry
643 *
644 * Notes: Low level drivers may call this at any time and we will do
645 * "The Right Thing." We are interrupt context safe.
646 */
647int scsi_track_queue_full(struct scsi_device *sdev, int depth)
648{
Vasu Dev4a840672009-10-22 15:46:33 -0700649
650 /*
651 * Don't let QUEUE_FULLs on the same
652 * jiffies count, they could all be from
653 * same event.
654 */
655 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 return 0;
657
Vasu Dev4a840672009-10-22 15:46:33 -0700658 sdev->last_queue_full_time = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 if (sdev->last_queue_full_depth != depth) {
660 sdev->last_queue_full_count = 1;
661 sdev->last_queue_full_depth = depth;
662 } else {
663 sdev->last_queue_full_count++;
664 }
665
666 if (sdev->last_queue_full_count <= 10)
667 return 0;
Christoph Hellwig609aa222014-10-30 11:54:58 +0100668
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100669 return scsi_change_queue_depth(sdev, depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670}
671EXPORT_SYMBOL(scsi_track_queue_full);
672
673/**
Matthew Wilcox881a2562008-12-31 13:12:46 -0500674 * scsi_vpd_inquiry - Request a device provide us with a VPD page
675 * @sdev: The device to ask
676 * @buffer: Where to put the result
677 * @page: Which Vital Product Data to return
678 * @len: The length of the buffer
679 *
680 * This is an internal helper function. You probably want to use
681 * scsi_get_vpd_page instead.
682 *
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100683 * Returns size of the vpd page on success or a negative error number.
Matthew Wilcox881a2562008-12-31 13:12:46 -0500684 */
685static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
686 u8 page, unsigned len)
687{
688 int result;
689 unsigned char cmd[16];
690
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100691 if (len < 4)
692 return -EINVAL;
693
Matthew Wilcox881a2562008-12-31 13:12:46 -0500694 cmd[0] = INQUIRY;
695 cmd[1] = 1; /* EVPD */
696 cmd[2] = page;
697 cmd[3] = len >> 8;
698 cmd[4] = len & 0xff;
699 cmd[5] = 0; /* Control byte */
700
701 /*
702 * I'm not convinced we need to try quite this hard to get VPD, but
703 * all the existing users tried this hard.
704 */
705 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
James Bottomley95a36392009-08-11 10:59:09 -0500706 len, NULL, 30 * HZ, 3, NULL);
Matthew Wilcox881a2562008-12-31 13:12:46 -0500707 if (result)
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100708 return -EIO;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500709
710 /* Sanity check that we got the page back that we asked for */
711 if (buffer[1] != page)
712 return -EIO;
713
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100714 return get_unaligned_be16(&buffer[2]) + 4;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500715}
716
717/**
718 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
719 * @sdev: The device to ask
720 * @page: Which Vital Product Data to return
Randy Dunlap786f8ba2010-02-28 17:32:45 -0800721 * @buf: where to store the VPD
722 * @buf_len: number of bytes in the VPD buffer area
Matthew Wilcox881a2562008-12-31 13:12:46 -0500723 *
724 * SCSI devices may optionally supply Vital Product Data. Each 'page'
725 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
726 * If the device supports this VPD page, this routine returns a pointer
727 * to a buffer containing the data from that page. The caller is
728 * responsible for calling kfree() on this pointer when it is no longer
729 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
730 */
James Bottomleye3deec02009-11-03 12:33:07 -0600731int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
732 int buf_len)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500733{
734 int i, result;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500735
Martin K. Petersen75625232013-07-30 22:58:34 -0400736 if (sdev->skip_vpd_pages)
737 goto fail;
738
Matthew Wilcox881a2562008-12-31 13:12:46 -0500739 /* Ask for all the pages supported by this device */
James Bottomleye3deec02009-11-03 12:33:07 -0600740 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100741 if (result < 4)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500742 goto fail;
743
744 /* If the user actually wanted this page, we can skip the rest */
745 if (page == 0)
Martin K. Petersen16d3ea22010-09-10 01:20:27 -0400746 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500747
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100748 for (i = 4; i < min(result, buf_len); i++)
749 if (buf[i] == page)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500750 goto found;
James Bottomleye3deec02009-11-03 12:33:07 -0600751
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100752 if (i < result && i >= buf_len)
James Bottomleye3deec02009-11-03 12:33:07 -0600753 /* ran off the end of the buffer, give us benefit of doubt */
754 goto found;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500755 /* The device claims it doesn't support the requested page */
756 goto fail;
757
758 found:
James Bottomleye3deec02009-11-03 12:33:07 -0600759 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100760 if (result < 0)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500761 goto fail;
762
James Bottomleye3deec02009-11-03 12:33:07 -0600763 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500764
765 fail:
James Bottomleye3deec02009-11-03 12:33:07 -0600766 return -EINVAL;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500767}
768EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
769
770/**
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100771 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
772 * @sdev: The device to ask
773 *
774 * Attach the 'Device Identification' VPD page (0x83) and the
775 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
776 * structure. This information can be used to identify the device
777 * uniquely.
778 */
779void scsi_attach_vpd(struct scsi_device *sdev)
780{
781 int result, i;
782 int vpd_len = SCSI_VPD_PG_LEN;
783 int pg80_supported = 0;
784 int pg83_supported = 0;
Hannes Reinecke09e2b0b2015-11-09 13:24:28 +0100785 unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL;
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100786
Hannes Reinecke5ddfe082016-04-01 08:57:36 +0200787 if (!scsi_device_supports_vpd(sdev))
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100788 return;
Hannes Reinecke5ddfe082016-04-01 08:57:36 +0200789
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100790retry_pg0:
791 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
792 if (!vpd_buf)
793 return;
794
795 /* Ask for all the pages supported by this device */
796 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
797 if (result < 0) {
798 kfree(vpd_buf);
799 return;
800 }
801 if (result > vpd_len) {
802 vpd_len = result;
803 kfree(vpd_buf);
804 goto retry_pg0;
805 }
806
807 for (i = 4; i < result; i++) {
808 if (vpd_buf[i] == 0x80)
809 pg80_supported = 1;
810 if (vpd_buf[i] == 0x83)
811 pg83_supported = 1;
812 }
813 kfree(vpd_buf);
814 vpd_len = SCSI_VPD_PG_LEN;
815
816 if (pg80_supported) {
817retry_pg80:
818 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
819 if (!vpd_buf)
820 return;
821
822 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
823 if (result < 0) {
824 kfree(vpd_buf);
825 return;
826 }
827 if (result > vpd_len) {
828 vpd_len = result;
829 kfree(vpd_buf);
830 goto retry_pg80;
831 }
Hannes Reinecke09e2b0b2015-11-09 13:24:28 +0100832 mutex_lock(&sdev->inquiry_mutex);
833 orig_vpd_buf = sdev->vpd_pg80;
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100834 sdev->vpd_pg80_len = result;
Hannes Reinecke09e2b0b2015-11-09 13:24:28 +0100835 rcu_assign_pointer(sdev->vpd_pg80, vpd_buf);
836 mutex_unlock(&sdev->inquiry_mutex);
837 synchronize_rcu();
838 if (orig_vpd_buf) {
839 kfree(orig_vpd_buf);
840 orig_vpd_buf = NULL;
841 }
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100842 vpd_len = SCSI_VPD_PG_LEN;
843 }
844
845 if (pg83_supported) {
846retry_pg83:
847 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
848 if (!vpd_buf)
849 return;
850
851 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
852 if (result < 0) {
853 kfree(vpd_buf);
854 return;
855 }
856 if (result > vpd_len) {
857 vpd_len = result;
858 kfree(vpd_buf);
859 goto retry_pg83;
860 }
Hannes Reinecke09e2b0b2015-11-09 13:24:28 +0100861 mutex_lock(&sdev->inquiry_mutex);
862 orig_vpd_buf = sdev->vpd_pg83;
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100863 sdev->vpd_pg83_len = result;
Hannes Reinecke09e2b0b2015-11-09 13:24:28 +0100864 rcu_assign_pointer(sdev->vpd_pg83, vpd_buf);
865 mutex_unlock(&sdev->inquiry_mutex);
866 synchronize_rcu();
867 if (orig_vpd_buf)
868 kfree(orig_vpd_buf);
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100869 }
870}
871
872/**
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400873 * scsi_report_opcode - Find out if a given command opcode is supported
874 * @sdev: scsi device to query
875 * @buffer: scratch buffer (must be at least 20 bytes long)
876 * @len: length of buffer
877 * @opcode: opcode for command to look up
878 *
879 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400880 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
881 * unsupported and 1 if the device claims to support the command.
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400882 */
883int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
884 unsigned int len, unsigned char opcode)
885{
886 unsigned char cmd[16];
887 struct scsi_sense_hdr sshdr;
888 int result;
889
890 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400891 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400892
893 memset(cmd, 0, 16);
894 cmd[0] = MAINTENANCE_IN;
895 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
896 cmd[2] = 1; /* One command format */
897 cmd[3] = opcode;
898 put_unaligned_be32(len, &cmd[6]);
899 memset(buffer, 0, len);
900
901 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
902 &sshdr, 30 * HZ, 3, NULL);
903
904 if (result && scsi_sense_valid(&sshdr) &&
905 sshdr.sense_key == ILLEGAL_REQUEST &&
906 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400907 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400908
909 if ((buffer[1] & 3) == 3) /* Command supported */
910 return 1;
911
912 return 0;
913}
914EXPORT_SYMBOL(scsi_report_opcode);
915
916/**
Rob Landleyeb448202007-11-03 13:30:39 -0500917 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 * @sdev: device to get a reference to
919 *
Rob Landleyeb448202007-11-03 13:30:39 -0500920 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 * of the underlying LLDD module. You must hold host_lock of the
922 * parent Scsi_Host or already have a reference when calling this.
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100923 *
924 * This will fail if a device is deleted or cancelled, or when the LLD module
925 * is in the process of being unloaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 */
927int scsi_device_get(struct scsi_device *sdev)
928{
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100929 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
930 goto fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 if (!get_device(&sdev->sdev_gendev))
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100932 goto fail;
933 if (!try_module_get(sdev->host->hostt->module))
934 goto fail_put_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 return 0;
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100936
937fail_put_device:
938 put_device(&sdev->sdev_gendev);
939fail:
940 return -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941}
942EXPORT_SYMBOL(scsi_device_get);
943
944/**
945 * scsi_device_put - release a reference to a scsi_device
946 * @sdev: device to release a reference on.
947 *
Rob Landleyeb448202007-11-03 13:30:39 -0500948 * Description: Release a reference to the scsi_device and decrements the use
949 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 * user vanishes.
951 */
952void scsi_device_put(struct scsi_device *sdev)
953{
Rusty Russelldc4515e2015-01-23 13:22:47 +1030954 module_put(sdev->host->hostt->module);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 put_device(&sdev->sdev_gendev);
956}
957EXPORT_SYMBOL(scsi_device_put);
958
Rob Landleyeb448202007-11-03 13:30:39 -0500959/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
961 struct scsi_device *prev)
962{
963 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
964 struct scsi_device *next = NULL;
965 unsigned long flags;
966
967 spin_lock_irqsave(shost->host_lock, flags);
968 while (list->next != &shost->__devices) {
969 next = list_entry(list->next, struct scsi_device, siblings);
970 /* skip devices that we can't get a reference to */
971 if (!scsi_device_get(next))
972 break;
973 next = NULL;
974 list = list->next;
975 }
976 spin_unlock_irqrestore(shost->host_lock, flags);
977
978 if (prev)
979 scsi_device_put(prev);
980 return next;
981}
982EXPORT_SYMBOL(__scsi_iterate_devices);
983
984/**
985 * starget_for_each_device - helper to walk all devices of a target
986 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -0500987 * @data: Opaque passed to each function call.
988 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800990 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 * a reference that must be released by scsi_host_put when breaking
992 * out of the loop.
993 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800994void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 void (*fn)(struct scsi_device *, void *))
996{
997 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
998 struct scsi_device *sdev;
999
1000 shost_for_each_device(sdev, shost) {
1001 if ((sdev->channel == starget->channel) &&
1002 (sdev->id == starget->id))
1003 fn(sdev, data);
1004 }
1005}
1006EXPORT_SYMBOL(starget_for_each_device);
1007
1008/**
Randy Dunlap14f501a2008-02-03 15:06:36 -08001009 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001010 * @starget: target whose devices we want to iterate over.
Randy Dunlap14f501a2008-02-03 15:06:36 -08001011 * @data: parameter for callback @fn()
1012 * @fn: callback function that is invoked for each device
Maciej W. Rozycki522939d2007-12-10 15:49:31 -08001013 *
1014 * This traverses over each device of @starget. It does _not_
1015 * take a reference on the scsi_device, so the whole loop must be
1016 * protected by shost->host_lock.
1017 *
1018 * Note: The only reason why drivers would want to use this is because
1019 * they need to access the device list in irq context. Otherwise you
1020 * really want to use starget_for_each_device instead.
1021 **/
1022void __starget_for_each_device(struct scsi_target *starget, void *data,
1023 void (*fn)(struct scsi_device *, void *))
1024{
1025 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1026 struct scsi_device *sdev;
1027
1028 __shost_for_each_device(sdev, shost) {
1029 if ((sdev->channel == starget->channel) &&
1030 (sdev->id == starget->id))
1031 fn(sdev, data);
1032 }
1033}
1034EXPORT_SYMBOL(__starget_for_each_device);
1035
1036/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1038 * @starget: SCSI target pointer
1039 * @lun: SCSI Logical Unit Number
1040 *
Rob Landleyeb448202007-11-03 13:30:39 -05001041 * Description: Looks up the scsi_device with the specified @lun for a given
1042 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 * reference. You must hold the host's host_lock over this call and
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001044 * any access to the returned scsi_device. A scsi_device in state
1045 * SDEV_DEL is skipped.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -08001047 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001048 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 * really want to use scsi_device_lookup_by_target instead.
1050 **/
1051struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001052 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053{
1054 struct scsi_device *sdev;
1055
1056 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
Hannes Reinecke32aeef62009-01-13 16:50:37 +01001057 if (sdev->sdev_state == SDEV_DEL)
1058 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 if (sdev->lun ==lun)
1060 return sdev;
1061 }
1062
1063 return NULL;
1064}
1065EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1066
1067/**
1068 * scsi_device_lookup_by_target - find a device given the target
1069 * @starget: SCSI target pointer
1070 * @lun: SCSI Logical Unit Number
1071 *
Bartlomiej Zolnierkiewicz477e6082009-04-27 20:54:22 +02001072 * Description: Looks up the scsi_device with the specified @lun for a given
1073 * @starget. The returned scsi_device has an additional reference that
Rob Landleyeb448202007-11-03 13:30:39 -05001074 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 **/
1076struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001077 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078{
1079 struct scsi_device *sdev;
1080 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1081 unsigned long flags;
1082
1083 spin_lock_irqsave(shost->host_lock, flags);
1084 sdev = __scsi_device_lookup_by_target(starget, lun);
1085 if (sdev && scsi_device_get(sdev))
1086 sdev = NULL;
1087 spin_unlock_irqrestore(shost->host_lock, flags);
1088
1089 return sdev;
1090}
1091EXPORT_SYMBOL(scsi_device_lookup_by_target);
1092
1093/**
Rob Landleyeb448202007-11-03 13:30:39 -05001094 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 * @shost: SCSI host pointer
1096 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -05001097 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 * @lun: SCSI Logical Unit Number
1099 *
Rob Landleyeb448202007-11-03 13:30:39 -05001100 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1101 * for a given host. The returned scsi_device does not have an additional
1102 * reference. You must hold the host's host_lock over this call and any access
1103 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 *
1105 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001106 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 * really want to use scsi_device_lookup instead.
1108 **/
1109struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001110 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111{
1112 struct scsi_device *sdev;
1113
1114 list_for_each_entry(sdev, &shost->__devices, siblings) {
1115 if (sdev->channel == channel && sdev->id == id &&
1116 sdev->lun ==lun)
1117 return sdev;
1118 }
1119
1120 return NULL;
1121}
1122EXPORT_SYMBOL(__scsi_device_lookup);
1123
1124/**
1125 * scsi_device_lookup - find a device given the host
1126 * @shost: SCSI host pointer
1127 * @channel: SCSI channel (zero if only one channel)
1128 * @id: SCSI target number (physical unit number)
1129 * @lun: SCSI Logical Unit Number
1130 *
Rob Landleyeb448202007-11-03 13:30:39 -05001131 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1132 * for a given host. The returned scsi_device has an additional reference that
1133 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 **/
1135struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +02001136 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137{
1138 struct scsi_device *sdev;
1139 unsigned long flags;
1140
1141 spin_lock_irqsave(shost->host_lock, flags);
1142 sdev = __scsi_device_lookup(shost, channel, id, lun);
1143 if (sdev && scsi_device_get(sdev))
1144 sdev = NULL;
1145 spin_unlock_irqrestore(shost->host_lock, flags);
1146
1147 return sdev;
1148}
1149EXPORT_SYMBOL(scsi_device_lookup);
1150
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151MODULE_DESCRIPTION("SCSI core");
1152MODULE_LICENSE("GPL");
1153
1154module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1155MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1156
Christoph Hellwig24c20f12014-09-30 16:43:46 +02001157#ifdef CONFIG_SCSI_MQ_DEFAULT
1158bool scsi_use_blk_mq = true;
1159#else
Christoph Hellwigd2852032014-01-17 12:06:53 +01001160bool scsi_use_blk_mq = false;
Christoph Hellwig24c20f12014-09-30 16:43:46 +02001161#endif
Christoph Hellwigd2852032014-01-17 12:06:53 +01001162module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
Christoph Hellwig9aa9cc42016-07-13 13:19:05 +09001163EXPORT_SYMBOL_GPL(scsi_use_blk_mq);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001164
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165static int __init init_scsi(void)
1166{
Jens Axboe9bf09c22006-09-30 20:31:11 +02001167 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168
1169 error = scsi_init_queue();
1170 if (error)
1171 return error;
1172 error = scsi_init_procfs();
1173 if (error)
1174 goto cleanup_queue;
1175 error = scsi_init_devinfo();
1176 if (error)
1177 goto cleanup_procfs;
1178 error = scsi_init_hosts();
1179 if (error)
1180 goto cleanup_devlist;
1181 error = scsi_init_sysctl();
1182 if (error)
1183 goto cleanup_hosts;
1184 error = scsi_sysfs_register();
1185 if (error)
1186 goto cleanup_sysctl;
1187
James Smart84314fd2006-08-18 17:30:09 -04001188 scsi_netlink_init();
1189
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1191 return 0;
1192
1193cleanup_sysctl:
1194 scsi_exit_sysctl();
1195cleanup_hosts:
1196 scsi_exit_hosts();
1197cleanup_devlist:
1198 scsi_exit_devinfo();
1199cleanup_procfs:
1200 scsi_exit_procfs();
1201cleanup_queue:
1202 scsi_exit_queue();
1203 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1204 -error);
1205 return error;
1206}
1207
1208static void __exit exit_scsi(void)
1209{
James Smart84314fd2006-08-18 17:30:09 -04001210 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 scsi_sysfs_unregister();
1212 scsi_exit_sysctl();
1213 scsi_exit_hosts();
1214 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 scsi_exit_procfs();
1216 scsi_exit_queue();
Dan Williamsa4683482012-07-09 19:33:30 -07001217 async_unregister_domain(&scsi_sd_probe_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218}
1219
1220subsys_initcall(init_scsi);
1221module_exit(exit_scsi);