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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
5 *
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
12 * Bug correction thanks go to :
13 * Rik Faith <faith@cs.unc.edu>
14 * Tommy Thorn <tthorn>
15 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
16 *
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
19 * enhancements.
20 *
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
23 *
24 * Added request_module("scsi_hostadapter") for kerneld:
25 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
26 * Bjorn Ekwall <bj0rn@blox.se>
27 * (changed to kmod)
28 *
29 * Major improvements to the timeout, abort, and reset processing,
30 * as well as performance modifications for large queue depths by
31 * Leonard N. Zubkoff <lnz@dandelion.com>
32 *
33 * Converted cli() code to spinlocks, Ingo Molnar
34 *
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
36 *
37 * out_of_space hacks, D. Gilbert (dpg) 990608
38 */
39
40#include <linux/module.h>
41#include <linux/moduleparam.h>
42#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <linux/timer.h>
44#include <linux/string.h>
45#include <linux/slab.h>
46#include <linux/blkdev.h>
47#include <linux/delay.h>
48#include <linux/init.h>
49#include <linux/completion.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/unistd.h>
51#include <linux/spinlock.h>
52#include <linux/kmod.h>
53#include <linux/interrupt.h>
54#include <linux/notifier.h>
55#include <linux/cpu.h>
Arjan van de Ven0b950672006-01-11 13:16:10 +010056#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58#include <scsi/scsi.h>
59#include <scsi/scsi_cmnd.h>
60#include <scsi/scsi_dbg.h>
61#include <scsi/scsi_device.h>
Linus Torvalds7b3d9542008-01-06 10:17:12 -080062#include <scsi/scsi_driver.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#include <scsi/scsi_eh.h>
64#include <scsi/scsi_host.h>
65#include <scsi/scsi_tcq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67#include "scsi_priv.h"
68#include "scsi_logging.h"
69
Adrian Bunk52c1da32005-06-23 22:05:33 -070070static void scsi_done(struct scsi_cmnd *cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72/*
73 * Definitions and constants.
74 */
75
76#define MIN_RESET_DELAY (2*HZ)
77
78/* Do not call reset on error if we just did a reset within 15 sec. */
79#define MIN_RESET_PERIOD (15*HZ)
80
81/*
82 * Macro to determine the size of SCSI command. This macro takes vendor
83 * unique commands into account. SCSI commands in groups 6 and 7 are
84 * vendor unique and we will depend upon the command length being
85 * supplied correctly in cmd_len.
86 */
87#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
88 COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
89
90/*
91 * Note - the initial logging level can be set here to log events at boot time.
92 * After the system is up, you may enable logging via the /proc interface.
93 */
94unsigned int scsi_logging_level;
95#if defined(CONFIG_SCSI_LOGGING)
96EXPORT_SYMBOL(scsi_logging_level);
97#endif
98
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -060099/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
100 * You may not alter any existing entry (although adding new ones is
101 * encouraged once assigned by ANSI/INCITS T10
102 */
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600103static const char *const scsi_device_types[] = {
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600104 "Direct-Access ",
105 "Sequential-Access",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 "Printer ",
107 "Processor ",
108 "WORM ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600109 "CD-ROM ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 "Scanner ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600111 "Optical Device ",
112 "Medium Changer ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 "Communications ",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600114 "ASC IT8 ",
115 "ASC IT8 ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 "RAID ",
117 "Enclosure ",
Matthew Wilcox8a1cdc92006-09-24 20:22:52 -0600118 "Direct-Access-RBC",
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600119 "Optical card ",
120 "Bridge controller",
121 "Object storage ",
122 "Automation/Drive ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123};
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600124
Rob Landleyeb448202007-11-03 13:30:39 -0500125/**
126 * scsi_device_type - Return 17 char string indicating device type.
127 * @type: type number to look up
128 */
129
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600130const char * scsi_device_type(unsigned type)
131{
132 if (type == 0x1e)
133 return "Well-known LUN ";
134 if (type == 0x1f)
135 return "No Device ";
Eric Sesterhenn80c6e3c2006-09-26 13:22:13 +0200136 if (type >= ARRAY_SIZE(scsi_device_types))
Matthew Wilcox4ff36712006-07-04 12:15:20 -0600137 return "Unknown ";
138 return scsi_device_types[type];
139}
140
141EXPORT_SYMBOL(scsi_device_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143struct scsi_host_cmd_pool {
James Bottomley5b7f1682008-01-20 09:28:24 -0600144 struct kmem_cache *cmd_slab;
145 struct kmem_cache *sense_slab;
146 unsigned int users;
147 char *cmd_name;
148 char *sense_name;
149 unsigned int slab_flags;
150 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151};
152
153static struct scsi_host_cmd_pool scsi_cmd_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600154 .cmd_name = "scsi_cmd_cache",
155 .sense_name = "scsi_sense_cache",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 .slab_flags = SLAB_HWCACHE_ALIGN,
157};
158
159static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
James Bottomley5b7f1682008-01-20 09:28:24 -0600160 .cmd_name = "scsi_cmd_cache(DMA)",
161 .sense_name = "scsi_sense_cache(DMA)",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
163 .gfp_mask = __GFP_DMA,
164};
165
Arjan van de Ven0b950672006-01-11 13:16:10 +0100166static DEFINE_MUTEX(host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Rob Landleyeb448202007-11-03 13:30:39 -0500168/**
169 * __scsi_get_command - Allocate a struct scsi_cmnd
170 * @shost: host to transmit command
171 * @gfp_mask: allocation mask
172 *
173 * Description: allocate a struct scsi_cmd from host's slab, recycling from the
174 * host's free_list if necessary.
175 */
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900176struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
178 struct scsi_cmnd *cmd;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900179 unsigned char *buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
James Bottomley5b7f1682008-01-20 09:28:24 -0600181 cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab,
182 gfp_mask | shost->cmd_pool->gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 if (unlikely(!cmd)) {
185 unsigned long flags;
186
187 spin_lock_irqsave(&shost->free_list_lock, flags);
188 if (likely(!list_empty(&shost->free_list))) {
189 cmd = list_entry(shost->free_list.next,
190 struct scsi_cmnd, list);
191 list_del_init(&cmd->list);
192 }
193 spin_unlock_irqrestore(&shost->free_list_lock, flags);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900194
195 if (cmd) {
196 buf = cmd->sense_buffer;
197 memset(cmd, 0, sizeof(*cmd));
198 cmd->sense_buffer = buf;
199 }
200 } else {
James Bottomley5b7f1682008-01-20 09:28:24 -0600201 buf = kmem_cache_alloc(shost->cmd_pool->sense_slab,
202 gfp_mask | shost->cmd_pool->gfp_mask);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900203 if (likely(buf)) {
204 memset(cmd, 0, sizeof(*cmd));
205 cmd->sense_buffer = buf;
206 } else {
James Bottomley5b7f1682008-01-20 09:28:24 -0600207 kmem_cache_free(shost->cmd_pool->cmd_slab, cmd);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900208 cmd = NULL;
209 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 }
211
212 return cmd;
213}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900214EXPORT_SYMBOL_GPL(__scsi_get_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Rob Landleyeb448202007-11-03 13:30:39 -0500216/**
217 * scsi_get_command - Allocate and setup a scsi command block
218 * @dev: parent scsi device
219 * @gfp_mask: allocator flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 *
221 * Returns: The allocated scsi command structure.
222 */
Al Viroc53033f2005-10-21 03:22:08 -0400223struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
225 struct scsi_cmnd *cmd;
226
227 /* Bail if we can't get a reference to the device */
228 if (!get_device(&dev->sdev_gendev))
229 return NULL;
230
231 cmd = __scsi_get_command(dev->host, gfp_mask);
232
233 if (likely(cmd != NULL)) {
234 unsigned long flags;
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 cmd->device = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 init_timer(&cmd->eh_timeout);
238 INIT_LIST_HEAD(&cmd->list);
239 spin_lock_irqsave(&dev->list_lock, flags);
240 list_add_tail(&cmd->list, &dev->cmd_list);
241 spin_unlock_irqrestore(&dev->list_lock, flags);
Matthew Dobson79e448b2005-11-21 21:32:29 -0800242 cmd->jiffies_at_alloc = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 } else
244 put_device(&dev->sdev_gendev);
245
246 return cmd;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900247}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248EXPORT_SYMBOL(scsi_get_command);
249
Rob Landleyeb448202007-11-03 13:30:39 -0500250/**
251 * __scsi_put_command - Free a struct scsi_cmnd
252 * @shost: dev->host
253 * @cmd: Command to free
254 * @dev: parent scsi device
255 */
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900256void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
257 struct device *dev)
258{
259 unsigned long flags;
260
261 /* changing locks here, don't need to restore the irq state */
262 spin_lock_irqsave(&shost->free_list_lock, flags);
263 if (unlikely(list_empty(&shost->free_list))) {
264 list_add(&cmd->list, &shost->free_list);
265 cmd = NULL;
266 }
267 spin_unlock_irqrestore(&shost->free_list_lock, flags);
268
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900269 if (likely(cmd != NULL)) {
James Bottomley5b7f1682008-01-20 09:28:24 -0600270 kmem_cache_free(shost->cmd_pool->sense_slab,
271 cmd->sense_buffer);
272 kmem_cache_free(shost->cmd_pool->cmd_slab, cmd);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900273 }
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900274
275 put_device(dev);
276}
277EXPORT_SYMBOL(__scsi_put_command);
278
Rob Landleyeb448202007-11-03 13:30:39 -0500279/**
280 * scsi_put_command - Free a scsi command block
281 * @cmd: command block to free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 *
283 * Returns: Nothing.
284 *
285 * Notes: The command must not belong to any lists.
286 */
287void scsi_put_command(struct scsi_cmnd *cmd)
288{
289 struct scsi_device *sdev = cmd->device;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 unsigned long flags;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900291
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 /* serious error if the command hasn't come from a device list */
293 spin_lock_irqsave(&cmd->device->list_lock, flags);
294 BUG_ON(list_empty(&cmd->list));
295 list_del_init(&cmd->list);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900296 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900298 __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299}
300EXPORT_SYMBOL(scsi_put_command);
301
Rob Landleyeb448202007-11-03 13:30:39 -0500302/**
303 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
304 * @shost: host to allocate the freelist for.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 *
Rob Landleyeb448202007-11-03 13:30:39 -0500306 * Description: The command freelist protects against system-wide out of memory
307 * deadlock by preallocating one SCSI command structure for each host, so the
308 * system can always write to a swap file on a device associated with that host.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 *
310 * Returns: Nothing.
311 */
312int scsi_setup_command_freelist(struct Scsi_Host *shost)
313{
314 struct scsi_host_cmd_pool *pool;
315 struct scsi_cmnd *cmd;
316
317 spin_lock_init(&shost->free_list_lock);
318 INIT_LIST_HEAD(&shost->free_list);
319
320 /*
321 * Select a command slab for this host and create it if not
Rob Landleyeb448202007-11-03 13:30:39 -0500322 * yet existent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 */
Arjan van de Ven0b950672006-01-11 13:16:10 +0100324 mutex_lock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool);
326 if (!pool->users) {
James Bottomley5b7f1682008-01-20 09:28:24 -0600327 pool->cmd_slab = kmem_cache_create(pool->cmd_name,
328 sizeof(struct scsi_cmnd), 0,
329 pool->slab_flags, NULL);
330 if (!pool->cmd_slab)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 goto fail;
James Bottomley5b7f1682008-01-20 09:28:24 -0600332
333 pool->sense_slab = kmem_cache_create(pool->sense_name,
334 SCSI_SENSE_BUFFERSIZE, 0,
335 pool->slab_flags, NULL);
336 if (!pool->sense_slab) {
337 kmem_cache_destroy(pool->cmd_slab);
338 goto fail;
339 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 }
341
342 pool->users++;
343 shost->cmd_pool = pool;
Arjan van de Ven0b950672006-01-11 13:16:10 +0100344 mutex_unlock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /*
347 * Get one backup command for this host.
348 */
James Bottomley5b7f1682008-01-20 09:28:24 -0600349 cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab,
350 GFP_KERNEL | shost->cmd_pool->gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 if (!cmd)
352 goto fail2;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900353
James Bottomley5b7f1682008-01-20 09:28:24 -0600354 cmd->sense_buffer = kmem_cache_alloc(shost->cmd_pool->sense_slab,
355 GFP_KERNEL |
356 shost->cmd_pool->gfp_mask);
357 if (!cmd->sense_buffer)
358 goto fail2;
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900359
FUJITA Tomonori166a7282008-01-08 07:59:05 +0900360 list_add(&cmd->list, &shost->free_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 return 0;
362
363 fail2:
James Bottomley5b7f1682008-01-20 09:28:24 -0600364 if (cmd)
365 kmem_cache_free(shost->cmd_pool->cmd_slab, cmd);
FUJITA Tomonori166a7282008-01-08 07:59:05 +0900366 mutex_lock(&host_cmd_pool_mutex);
James Bottomley5b7f1682008-01-20 09:28:24 -0600367 if (!--pool->users) {
368 kmem_cache_destroy(pool->cmd_slab);
369 kmem_cache_destroy(pool->sense_slab);
370 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 fail:
Arjan van de Ven0b950672006-01-11 13:16:10 +0100372 mutex_unlock(&host_cmd_pool_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374}
375
Rob Landleyeb448202007-11-03 13:30:39 -0500376/**
377 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
378 * @shost: host whose freelist is going to be destroyed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 */
380void scsi_destroy_command_freelist(struct Scsi_Host *shost)
381{
382 while (!list_empty(&shost->free_list)) {
383 struct scsi_cmnd *cmd;
384
385 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
386 list_del_init(&cmd->list);
James Bottomley5b7f1682008-01-20 09:28:24 -0600387 kmem_cache_free(shost->cmd_pool->sense_slab,
388 cmd->sense_buffer);
389 kmem_cache_free(shost->cmd_pool->cmd_slab, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 }
391
Arjan van de Ven0b950672006-01-11 13:16:10 +0100392 mutex_lock(&host_cmd_pool_mutex);
James Bottomley5b7f1682008-01-20 09:28:24 -0600393 if (!--shost->cmd_pool->users) {
394 kmem_cache_destroy(shost->cmd_pool->cmd_slab);
395 kmem_cache_destroy(shost->cmd_pool->sense_slab);
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900396 }
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900397 mutex_unlock(&host_cmd_pool_mutex);
398}
399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400#ifdef CONFIG_SCSI_LOGGING
401void scsi_log_send(struct scsi_cmnd *cmd)
402{
403 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
405 /*
406 * If ML QUEUE log level is greater than or equal to:
407 *
408 * 1: nothing (match completion)
409 *
410 * 2: log opcode + command of all commands
411 *
412 * 3: same as 2 plus dump cmd address
413 *
414 * 4: same as 3 plus dump extra junk
415 */
416 if (unlikely(scsi_logging_level)) {
417 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
418 SCSI_LOG_MLQUEUE_BITS);
419 if (level > 1) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500420 scmd_printk(KERN_INFO, cmd, "Send: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 if (level > 2)
422 printk("0x%p ", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500423 printk("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 scsi_print_command(cmd);
425 if (level > 3) {
426 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800427 " queuecommand 0x%p\n",
Boaz Harrosha73e45b2007-07-04 21:26:01 +0300428 scsi_sglist(cmd), scsi_bufflen(cmd),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500429 cmd->device->host->hostt->queuecommand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
431 }
432 }
433 }
434}
435
436void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
437{
438 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440 /*
441 * If ML COMPLETE log level is greater than or equal to:
442 *
443 * 1: log disposition, result, opcode + command, and conditionally
444 * sense data for failures or non SUCCESS dispositions.
445 *
446 * 2: same as 1 but for all command completions.
447 *
448 * 3: same as 2 plus dump cmd address
449 *
450 * 4: same as 3 plus dump extra junk
451 */
452 if (unlikely(scsi_logging_level)) {
453 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
454 SCSI_LOG_MLCOMPLETE_BITS);
455 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
456 (level > 1)) {
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500457 scmd_printk(KERN_INFO, cmd, "Done: ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 if (level > 2)
459 printk("0x%p ", cmd);
460 /*
461 * Dump truncated values, so we usually fit within
462 * 80 chars.
463 */
464 switch (disposition) {
465 case SUCCESS:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500466 printk("SUCCESS\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 break;
468 case NEEDS_RETRY:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500469 printk("RETRY\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 break;
471 case ADD_TO_MLQUEUE:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500472 printk("MLQUEUE\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 break;
474 case FAILED:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500475 printk("FAILED\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 break;
477 case TIMEOUT_ERROR:
478 /*
479 * If called via scsi_times_out.
480 */
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500481 printk("TIMEOUT\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 break;
483 default:
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500484 printk("UNKNOWN\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 }
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500486 scsi_print_result(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500488 if (status_byte(cmd->result) & CHECK_CONDITION)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 scsi_print_sense("", cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500490 if (level > 3)
491 scmd_printk(KERN_INFO, cmd,
492 "scsi host busy %d failed %d\n",
493 cmd->device->host->host_busy,
494 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 }
496 }
497}
498#endif
499
Rob Landleyeb448202007-11-03 13:30:39 -0500500/**
501 * scsi_cmd_get_serial - Assign a serial number to a command
502 * @host: the scsi host
503 * @cmd: command to assign serial number to
504 *
505 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 * and debugging purposes. Protected by the Host_Lock of host.
507 */
508static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
509{
510 cmd->serial_number = host->cmd_serial_number++;
511 if (cmd->serial_number == 0)
512 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513}
514
Rob Landleyeb448202007-11-03 13:30:39 -0500515/**
516 * scsi_dispatch_command - Dispatch a command to the low-level driver.
517 * @cmd: command block we are dispatching.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 *
Rob Landleyeb448202007-11-03 13:30:39 -0500519 * Return: nonzero return request was rejected and device's queue needs to be
520 * plugged.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 */
522int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
523{
524 struct Scsi_Host *host = cmd->device->host;
525 unsigned long flags = 0;
526 unsigned long timeout;
527 int rtn = 0;
528
529 /* check if the device is still usable */
530 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
531 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
532 * returns an immediate error upwards, and signals
533 * that the device is no longer present */
534 cmd->result = DID_NO_CONNECT << 16;
535 atomic_inc(&cmd->device->iorequest_cnt);
Mike Christie69b52892005-05-01 14:47:15 -0500536 __scsi_done(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 /* return 0 (because the command has been processed) */
538 goto out;
539 }
540
541 /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */
542 if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) {
543 /*
544 * in SDEV_BLOCK, the command is just put back on the device
545 * queue. The suspend state has already blocked the queue so
546 * future requests should not occur until the device
547 * transitions out of the suspend state.
548 */
549 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
550
551 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
552
553 /*
554 * NOTE: rtn is still zero here because we don't need the
555 * queue to be plugged on return (it's already stopped)
556 */
557 goto out;
558 }
559
560 /*
561 * If SCSI-2 or lower, store the LUN value in cmnd.
562 */
James Bottomley4d7db042006-03-31 20:07:45 -0600563 if (cmd->device->scsi_level <= SCSI_2 &&
564 cmd->device->scsi_level != SCSI_UNKNOWN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
566 (cmd->device->lun << 5 & 0xe0);
567 }
568
569 /*
570 * We will wait MIN_RESET_DELAY clock ticks after the last reset so
571 * we can avoid the drive not being ready.
572 */
573 timeout = host->last_reset + MIN_RESET_DELAY;
574
575 if (host->resetting && time_before(jiffies, timeout)) {
576 int ticks_remaining = timeout - jiffies;
577 /*
578 * NOTE: This may be executed from within an interrupt
579 * handler! This is bad, but for now, it'll do. The irq
580 * level of the interrupt handler has been masked out by the
581 * platform dependent interrupt handling code already, so the
582 * sti() here will not cause another call to the SCSI host's
583 * interrupt handler (assuming there is one irq-level per
584 * host).
585 */
586 while (--ticks_remaining >= 0)
587 mdelay(1 + 999 / HZ);
588 host->resetting = 0;
589 }
590
591 /*
592 * AK: unlikely race here: for some reason the timer could
593 * expire before the serial number is set up below.
594 */
595 scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);
596
597 scsi_log_send(cmd);
598
599 /*
600 * We will use a queued command if possible, otherwise we will
601 * emulate the queuing and calling of completion function ourselves.
602 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 atomic_inc(&cmd->device->iorequest_cnt);
604
605 /*
606 * Before we queue this command, check if the command
607 * length exceeds what the host adapter can handle.
608 */
609 if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
610 SCSI_LOG_MLQUEUE(3,
611 printk("queuecommand : command too long.\n"));
612 cmd->result = (DID_ABORT << 16);
613
614 scsi_done(cmd);
615 goto out;
616 }
617
618 spin_lock_irqsave(host->host_lock, flags);
619 scsi_cmd_get_serial(host, cmd);
620
Mike Andersond2c9d9e2005-06-16 11:13:42 -0700621 if (unlikely(host->shost_state == SHOST_DEL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 cmd->result = (DID_NO_CONNECT << 16);
623 scsi_done(cmd);
624 } else {
625 rtn = host->hostt->queuecommand(cmd, scsi_done);
626 }
627 spin_unlock_irqrestore(host->host_lock, flags);
628 if (rtn) {
Tejun Heo d8c37e72005-05-14 00:46:08 +0900629 if (scsi_delete_timer(cmd)) {
630 atomic_inc(&cmd->device->iodone_cnt);
631 scsi_queue_insert(cmd,
632 (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ?
633 rtn : SCSI_MLQUEUE_HOST_BUSY);
634 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 SCSI_LOG_MLQUEUE(3,
636 printk("queuecommand : request rejected\n"));
637 }
638
639 out:
640 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
641 return rtn;
642}
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644/**
Luben Tuikov89f48c42006-05-15 20:57:18 +0900645 * scsi_req_abort_cmd -- Request command recovery for the specified command
Rob Landleyeb448202007-11-03 13:30:39 -0500646 * @cmd: pointer to the SCSI command of interest
Luben Tuikov89f48c42006-05-15 20:57:18 +0900647 *
648 * This function requests that SCSI Core start recovery for the
649 * command by deleting the timer and adding the command to the eh
650 * queue. It can be called by either LLDDs or SCSI Core. LLDDs who
651 * implement their own error recovery MAY ignore the timeout event if
652 * they generated scsi_req_abort_cmd.
653 */
654void scsi_req_abort_cmd(struct scsi_cmnd *cmd)
655{
656 if (!scsi_delete_timer(cmd))
657 return;
658 scsi_times_out(cmd);
659}
660EXPORT_SYMBOL(scsi_req_abort_cmd);
661
662/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 * scsi_done - Enqueue the finished SCSI command into the done queue.
664 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
665 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
666 *
Rob Landleyeb448202007-11-03 13:30:39 -0500667 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
668 * which regains ownership of the SCSI command (de facto) from a LLDD, and
669 * enqueues the command to the done queue for further processing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 *
671 * This is the producer of the done queue who enqueues at the tail.
672 *
673 * This function is interrupt context safe.
674 */
Adrian Bunk52c1da32005-06-23 22:05:33 -0700675static void scsi_done(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676{
677 /*
Rob Landleyeb448202007-11-03 13:30:39 -0500678 * We don't have to worry about this one timing out anymore.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 * If we are unable to remove the timer, then the command
680 * has already timed out. In which case, we have no choice but to
681 * let the timeout function run, as we have no idea where in fact
682 * that function could really be. It might be on another processor,
683 * etc, etc.
684 */
685 if (!scsi_delete_timer(cmd))
686 return;
687 __scsi_done(cmd);
688}
689
690/* Private entry to scsi_done() to complete a command when the timer
691 * isn't running --- used by scsi_times_out */
692void __scsi_done(struct scsi_cmnd *cmd)
693{
Jens Axboe1aea6432006-01-09 16:03:03 +0100694 struct request *rq = cmd->request;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 /*
697 * Set the serial numbers back to zero
698 */
699 cmd->serial_number = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700
701 atomic_inc(&cmd->device->iodone_cnt);
702 if (cmd->result)
703 atomic_inc(&cmd->device->ioerr_cnt);
704
Jens Axboe1aea6432006-01-09 16:03:03 +0100705 BUG_ON(!rq);
706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 /*
Jens Axboe1aea6432006-01-09 16:03:03 +0100708 * The uptodate/nbytes values don't matter, as we allow partial
709 * completes and thus will check this in the softirq callback
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 */
Jens Axboe1aea6432006-01-09 16:03:03 +0100711 rq->completion_data = cmd;
712 blk_complete_request(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713}
714
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800715/* Move this to a header if it becomes more generally useful */
716static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
717{
718 return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
719}
720
Rob Landleyeb448202007-11-03 13:30:39 -0500721/**
722 * scsi_finish_command - cleanup and pass command back to upper layer
723 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 *
Rob Landleyeb448202007-11-03 13:30:39 -0500725 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 * request, waking processes that are waiting on results,
727 * etc.
728 */
729void scsi_finish_command(struct scsi_cmnd *cmd)
730{
731 struct scsi_device *sdev = cmd->device;
732 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800733 struct scsi_driver *drv;
734 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735
736 scsi_device_unbusy(sdev);
737
738 /*
739 * Clear the flags which say that the device/host is no longer
740 * capable of accepting new commands. These are set in scsi_queue.c
741 * for both the queue full condition on a device, and for a
742 * host full condition on the host.
743 *
744 * XXX(hch): What about locking?
745 */
746 shost->host_blocked = 0;
747 sdev->device_blocked = 0;
748
749 /*
750 * If we have valid sense information, then some kind of recovery
751 * must have taken place. Make a note of this.
752 */
753 if (SCSI_SENSE_VALID(cmd))
754 cmd->result |= (DRIVER_SENSE << 24);
755
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400756 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
757 "Notifying upper driver of completion "
758 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200760 good_bytes = scsi_bufflen(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800761 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
762 drv = scsi_cmd_to_driver(cmd);
763 if (drv->done)
764 good_bytes = drv->done(cmd);
765 }
766 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767}
768EXPORT_SYMBOL(scsi_finish_command);
769
Rob Landleyeb448202007-11-03 13:30:39 -0500770/**
771 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
772 * @sdev: SCSI Device in question
773 * @tagged: Do we use tagged queueing (non-0) or do we treat
774 * this device as an untagged device (0)
775 * @tags: Number of tags allowed if tagged queueing enabled,
776 * or number of commands the low level driver can
777 * queue up in non-tagged mode (as per cmd_per_lun).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 *
779 * Returns: Nothing
780 *
781 * Lock Status: None held on entry
782 *
783 * Notes: Low level drivers may call this at any time and we will do
784 * the right thing depending on whether or not the device is
785 * currently active and whether or not it even has the
786 * command blocks built yet.
787 */
788void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
789{
790 unsigned long flags;
791
792 /*
793 * refuse to set tagged depth to an unworkable size
794 */
795 if (tags <= 0)
796 return;
797
798 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
799
Rob Landleyeb448202007-11-03 13:30:39 -0500800 /* Check to see if the queue is managed by the block layer.
801 * If it is, and we fail to adjust the depth, exit. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 if (blk_queue_tagged(sdev->request_queue) &&
803 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
804 goto out;
805
806 sdev->queue_depth = tags;
807 switch (tagged) {
808 case MSG_ORDERED_TAG:
809 sdev->ordered_tags = 1;
810 sdev->simple_tags = 1;
811 break;
812 case MSG_SIMPLE_TAG:
813 sdev->ordered_tags = 0;
814 sdev->simple_tags = 1;
815 break;
816 default:
James Bottomley9ccfc752005-10-02 11:45:08 -0500817 sdev_printk(KERN_WARNING, sdev,
818 "scsi_adjust_queue_depth, bad queue type, "
819 "disabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 case 0:
821 sdev->ordered_tags = sdev->simple_tags = 0;
822 sdev->queue_depth = tags;
823 break;
824 }
825 out:
826 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
827}
828EXPORT_SYMBOL(scsi_adjust_queue_depth);
829
Rob Landleyeb448202007-11-03 13:30:39 -0500830/**
831 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
832 * @sdev: SCSI Device in question
833 * @depth: Current number of outstanding SCSI commands on this device,
834 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 *
Rob Landleyeb448202007-11-03 13:30:39 -0500836 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 * specific SCSI device to determine if and when there is a
838 * need to adjust the queue depth on the device.
839 *
Rob Landleyeb448202007-11-03 13:30:39 -0500840 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 * -1 - Drop back to untagged operation using host->cmd_per_lun
842 * as the untagged command depth
843 *
844 * Lock Status: None held on entry
845 *
846 * Notes: Low level drivers may call this at any time and we will do
847 * "The Right Thing." We are interrupt context safe.
848 */
849int scsi_track_queue_full(struct scsi_device *sdev, int depth)
850{
851 if ((jiffies >> 4) == sdev->last_queue_full_time)
852 return 0;
853
854 sdev->last_queue_full_time = (jiffies >> 4);
855 if (sdev->last_queue_full_depth != depth) {
856 sdev->last_queue_full_count = 1;
857 sdev->last_queue_full_depth = depth;
858 } else {
859 sdev->last_queue_full_count++;
860 }
861
862 if (sdev->last_queue_full_count <= 10)
863 return 0;
864 if (sdev->last_queue_full_depth < 8) {
865 /* Drop back to untagged */
866 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
867 return -1;
868 }
869
870 if (sdev->ordered_tags)
871 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
872 else
873 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
874 return depth;
875}
876EXPORT_SYMBOL(scsi_track_queue_full);
877
878/**
Rob Landleyeb448202007-11-03 13:30:39 -0500879 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 * @sdev: device to get a reference to
881 *
Rob Landleyeb448202007-11-03 13:30:39 -0500882 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 * of the underlying LLDD module. You must hold host_lock of the
884 * parent Scsi_Host or already have a reference when calling this.
885 */
886int scsi_device_get(struct scsi_device *sdev)
887{
James Bottomley85b6c722006-08-31 18:15:22 -0400888 if (sdev->sdev_state == SDEV_DEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 return -ENXIO;
890 if (!get_device(&sdev->sdev_gendev))
891 return -ENXIO;
James Bottomley85b6c722006-08-31 18:15:22 -0400892 /* We can fail this if we're doing SCSI operations
893 * from module exit (like cache flush) */
894 try_module_get(sdev->host->hostt->module);
895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 return 0;
897}
898EXPORT_SYMBOL(scsi_device_get);
899
900/**
901 * scsi_device_put - release a reference to a scsi_device
902 * @sdev: device to release a reference on.
903 *
Rob Landleyeb448202007-11-03 13:30:39 -0500904 * Description: Release a reference to the scsi_device and decrements the use
905 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 * user vanishes.
907 */
908void scsi_device_put(struct scsi_device *sdev)
909{
Ingo Molnar504fb372006-11-09 10:09:35 +0100910#ifdef CONFIG_MODULE_UNLOAD
James Bottomleyf479ab82006-09-06 09:00:29 -0500911 struct module *module = sdev->host->hostt->module;
912
James Bottomley85b6c722006-08-31 18:15:22 -0400913 /* The module refcount will be zero if scsi_device_get()
914 * was called from a module removal routine */
James Bottomleyf479ab82006-09-06 09:00:29 -0500915 if (module && module_refcount(module) != 0)
916 module_put(module);
Daniel Walkera506b442006-09-09 09:31:03 -0700917#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 put_device(&sdev->sdev_gendev);
919}
920EXPORT_SYMBOL(scsi_device_put);
921
Rob Landleyeb448202007-11-03 13:30:39 -0500922/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
924 struct scsi_device *prev)
925{
926 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
927 struct scsi_device *next = NULL;
928 unsigned long flags;
929
930 spin_lock_irqsave(shost->host_lock, flags);
931 while (list->next != &shost->__devices) {
932 next = list_entry(list->next, struct scsi_device, siblings);
933 /* skip devices that we can't get a reference to */
934 if (!scsi_device_get(next))
935 break;
936 next = NULL;
937 list = list->next;
938 }
939 spin_unlock_irqrestore(shost->host_lock, flags);
940
941 if (prev)
942 scsi_device_put(prev);
943 return next;
944}
945EXPORT_SYMBOL(__scsi_iterate_devices);
946
947/**
948 * starget_for_each_device - helper to walk all devices of a target
949 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -0500950 * @data: Opaque passed to each function call.
951 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800953 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 * a reference that must be released by scsi_host_put when breaking
955 * out of the loop.
956 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800957void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 void (*fn)(struct scsi_device *, void *))
959{
960 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
961 struct scsi_device *sdev;
962
963 shost_for_each_device(sdev, shost) {
964 if ((sdev->channel == starget->channel) &&
965 (sdev->id == starget->id))
966 fn(sdev, data);
967 }
968}
969EXPORT_SYMBOL(starget_for_each_device);
970
971/**
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800972 * __starget_for_each_device - helper to walk all devices of a target
973 * (UNLOCKED)
974 * @starget: target whose devices we want to iterate over.
975 *
976 * This traverses over each device of @starget. It does _not_
977 * take a reference on the scsi_device, so the whole loop must be
978 * protected by shost->host_lock.
979 *
980 * Note: The only reason why drivers would want to use this is because
981 * they need to access the device list in irq context. Otherwise you
982 * really want to use starget_for_each_device instead.
983 **/
984void __starget_for_each_device(struct scsi_target *starget, void *data,
985 void (*fn)(struct scsi_device *, void *))
986{
987 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
988 struct scsi_device *sdev;
989
990 __shost_for_each_device(sdev, shost) {
991 if ((sdev->channel == starget->channel) &&
992 (sdev->id == starget->id))
993 fn(sdev, data);
994 }
995}
996EXPORT_SYMBOL(__starget_for_each_device);
997
998/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1000 * @starget: SCSI target pointer
1001 * @lun: SCSI Logical Unit Number
1002 *
Rob Landleyeb448202007-11-03 13:30:39 -05001003 * Description: Looks up the scsi_device with the specified @lun for a given
1004 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 * reference. You must hold the host's host_lock over this call and
1006 * any access to the returned scsi_device.
1007 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -08001008 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001009 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 * really want to use scsi_device_lookup_by_target instead.
1011 **/
1012struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
1013 uint lun)
1014{
1015 struct scsi_device *sdev;
1016
1017 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
1018 if (sdev->lun ==lun)
1019 return sdev;
1020 }
1021
1022 return NULL;
1023}
1024EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1025
1026/**
1027 * scsi_device_lookup_by_target - find a device given the target
1028 * @starget: SCSI target pointer
1029 * @lun: SCSI Logical Unit Number
1030 *
Rob Landleyeb448202007-11-03 13:30:39 -05001031 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1032 * for a given host. The returned scsi_device has an additional reference that
1033 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 **/
1035struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
1036 uint lun)
1037{
1038 struct scsi_device *sdev;
1039 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1040 unsigned long flags;
1041
1042 spin_lock_irqsave(shost->host_lock, flags);
1043 sdev = __scsi_device_lookup_by_target(starget, lun);
1044 if (sdev && scsi_device_get(sdev))
1045 sdev = NULL;
1046 spin_unlock_irqrestore(shost->host_lock, flags);
1047
1048 return sdev;
1049}
1050EXPORT_SYMBOL(scsi_device_lookup_by_target);
1051
1052/**
Rob Landleyeb448202007-11-03 13:30:39 -05001053 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 * @shost: SCSI host pointer
1055 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -05001056 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 * @lun: SCSI Logical Unit Number
1058 *
Rob Landleyeb448202007-11-03 13:30:39 -05001059 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1060 * for a given host. The returned scsi_device does not have an additional
1061 * reference. You must hold the host's host_lock over this call and any access
1062 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 *
1064 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -05001065 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 * really want to use scsi_device_lookup instead.
1067 **/
1068struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
1069 uint channel, uint id, uint lun)
1070{
1071 struct scsi_device *sdev;
1072
1073 list_for_each_entry(sdev, &shost->__devices, siblings) {
1074 if (sdev->channel == channel && sdev->id == id &&
1075 sdev->lun ==lun)
1076 return sdev;
1077 }
1078
1079 return NULL;
1080}
1081EXPORT_SYMBOL(__scsi_device_lookup);
1082
1083/**
1084 * scsi_device_lookup - find a device given the host
1085 * @shost: SCSI host pointer
1086 * @channel: SCSI channel (zero if only one channel)
1087 * @id: SCSI target number (physical unit number)
1088 * @lun: SCSI Logical Unit Number
1089 *
Rob Landleyeb448202007-11-03 13:30:39 -05001090 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1091 * for a given host. The returned scsi_device has an additional reference that
1092 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 **/
1094struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1095 uint channel, uint id, uint lun)
1096{
1097 struct scsi_device *sdev;
1098 unsigned long flags;
1099
1100 spin_lock_irqsave(shost->host_lock, flags);
1101 sdev = __scsi_device_lookup(shost, channel, id, lun);
1102 if (sdev && scsi_device_get(sdev))
1103 sdev = NULL;
1104 spin_unlock_irqrestore(shost->host_lock, flags);
1105
1106 return sdev;
1107}
1108EXPORT_SYMBOL(scsi_device_lookup);
1109
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110MODULE_DESCRIPTION("SCSI core");
1111MODULE_LICENSE("GPL");
1112
1113module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1114MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1115
1116static int __init init_scsi(void)
1117{
Jens Axboe9bf09c22006-09-30 20:31:11 +02001118 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119
1120 error = scsi_init_queue();
1121 if (error)
1122 return error;
1123 error = scsi_init_procfs();
1124 if (error)
1125 goto cleanup_queue;
1126 error = scsi_init_devinfo();
1127 if (error)
1128 goto cleanup_procfs;
1129 error = scsi_init_hosts();
1130 if (error)
1131 goto cleanup_devlist;
1132 error = scsi_init_sysctl();
1133 if (error)
1134 goto cleanup_hosts;
1135 error = scsi_sysfs_register();
1136 if (error)
1137 goto cleanup_sysctl;
1138
James Smart84314fd2006-08-18 17:30:09 -04001139 scsi_netlink_init();
1140
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1142 return 0;
1143
1144cleanup_sysctl:
1145 scsi_exit_sysctl();
1146cleanup_hosts:
1147 scsi_exit_hosts();
1148cleanup_devlist:
1149 scsi_exit_devinfo();
1150cleanup_procfs:
1151 scsi_exit_procfs();
1152cleanup_queue:
1153 scsi_exit_queue();
1154 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1155 -error);
1156 return error;
1157}
1158
1159static void __exit exit_scsi(void)
1160{
James Smart84314fd2006-08-18 17:30:09 -04001161 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 scsi_sysfs_unregister();
1163 scsi_exit_sysctl();
1164 scsi_exit_hosts();
1165 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 scsi_exit_procfs();
1167 scsi_exit_queue();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168}
1169
1170subsys_initcall(init_scsi);
1171module_exit(exit_scsi);