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1da177e4 LT |
1 | /* |
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> | |
1da177e4 LT |
43 | #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> | |
1da177e4 LT |
50 | #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> | |
0b950672 | 56 | #include <linux/mutex.h> |
1da177e4 LT |
57 | |
58 | #include <scsi/scsi.h> | |
59 | #include <scsi/scsi_cmnd.h> | |
60 | #include <scsi/scsi_dbg.h> | |
61 | #include <scsi/scsi_device.h> | |
7b3d9545 | 62 | #include <scsi/scsi_driver.h> |
1da177e4 LT |
63 | #include <scsi/scsi_eh.h> |
64 | #include <scsi/scsi_host.h> | |
65 | #include <scsi/scsi_tcq.h> | |
1da177e4 LT |
66 | |
67 | #include "scsi_priv.h" | |
68 | #include "scsi_logging.h" | |
69 | ||
52c1da39 | 70 | static void scsi_done(struct scsi_cmnd *cmd); |
1da177e4 LT |
71 | |
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 | */ | |
94 | unsigned int scsi_logging_level; | |
95 | #if defined(CONFIG_SCSI_LOGGING) | |
96 | EXPORT_SYMBOL(scsi_logging_level); | |
97 | #endif | |
98 | ||
8a1cdc9c MW |
99 | /* 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 | */ | |
4ff36718 | 103 | static const char *const scsi_device_types[] = { |
8a1cdc9c MW |
104 | "Direct-Access ", |
105 | "Sequential-Access", | |
1da177e4 LT |
106 | "Printer ", |
107 | "Processor ", | |
108 | "WORM ", | |
8a1cdc9c | 109 | "CD-ROM ", |
1da177e4 | 110 | "Scanner ", |
8a1cdc9c MW |
111 | "Optical Device ", |
112 | "Medium Changer ", | |
1da177e4 | 113 | "Communications ", |
4ff36718 MW |
114 | "ASC IT8 ", |
115 | "ASC IT8 ", | |
1da177e4 LT |
116 | "RAID ", |
117 | "Enclosure ", | |
8a1cdc9c | 118 | "Direct-Access-RBC", |
4ff36718 MW |
119 | "Optical card ", |
120 | "Bridge controller", | |
121 | "Object storage ", | |
122 | "Automation/Drive ", | |
1da177e4 | 123 | }; |
4ff36718 | 124 | |
eb44820c RL |
125 | /** |
126 | * scsi_device_type - Return 17 char string indicating device type. | |
127 | * @type: type number to look up | |
128 | */ | |
129 | ||
4ff36718 MW |
130 | const char * scsi_device_type(unsigned type) |
131 | { | |
132 | if (type == 0x1e) | |
133 | return "Well-known LUN "; | |
134 | if (type == 0x1f) | |
135 | return "No Device "; | |
80c6e3c0 | 136 | if (type >= ARRAY_SIZE(scsi_device_types)) |
4ff36718 MW |
137 | return "Unknown "; |
138 | return scsi_device_types[type]; | |
139 | } | |
140 | ||
141 | EXPORT_SYMBOL(scsi_device_type); | |
1da177e4 | 142 | |
1da177e4 | 143 | struct scsi_host_cmd_pool { |
e18b890b | 144 | struct kmem_cache *slab; |
1da177e4 LT |
145 | unsigned int users; |
146 | char *name; | |
147 | unsigned int slab_flags; | |
c53033f6 | 148 | gfp_t gfp_mask; |
1da177e4 LT |
149 | }; |
150 | ||
151 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
152 | .name = "scsi_cmd_cache", | |
153 | .slab_flags = SLAB_HWCACHE_ALIGN, | |
154 | }; | |
155 | ||
156 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
157 | .name = "scsi_cmd_cache(DMA)", | |
158 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, | |
159 | .gfp_mask = __GFP_DMA, | |
160 | }; | |
161 | ||
0b950672 | 162 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 163 | |
eb44820c RL |
164 | /** |
165 | * __scsi_get_command - Allocate a struct scsi_cmnd | |
166 | * @shost: host to transmit command | |
167 | * @gfp_mask: allocation mask | |
168 | * | |
169 | * Description: allocate a struct scsi_cmd from host's slab, recycling from the | |
170 | * host's free_list if necessary. | |
171 | */ | |
b58d9154 | 172 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 LT |
173 | { |
174 | struct scsi_cmnd *cmd; | |
175 | ||
176 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
177 | gfp_mask | shost->cmd_pool->gfp_mask); | |
178 | ||
179 | if (unlikely(!cmd)) { | |
180 | unsigned long flags; | |
181 | ||
182 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
183 | if (likely(!list_empty(&shost->free_list))) { | |
184 | cmd = list_entry(shost->free_list.next, | |
185 | struct scsi_cmnd, list); | |
186 | list_del_init(&cmd->list); | |
187 | } | |
188 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
189 | } | |
190 | ||
191 | return cmd; | |
192 | } | |
b58d9154 | 193 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 | 194 | |
eb44820c RL |
195 | /** |
196 | * scsi_get_command - Allocate and setup a scsi command block | |
197 | * @dev: parent scsi device | |
198 | * @gfp_mask: allocator flags | |
1da177e4 LT |
199 | * |
200 | * Returns: The allocated scsi command structure. | |
201 | */ | |
c53033f6 | 202 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
203 | { |
204 | struct scsi_cmnd *cmd; | |
205 | ||
206 | /* Bail if we can't get a reference to the device */ | |
207 | if (!get_device(&dev->sdev_gendev)) | |
208 | return NULL; | |
209 | ||
210 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
211 | ||
212 | if (likely(cmd != NULL)) { | |
213 | unsigned long flags; | |
214 | ||
215 | memset(cmd, 0, sizeof(*cmd)); | |
216 | cmd->device = dev; | |
1da177e4 LT |
217 | init_timer(&cmd->eh_timeout); |
218 | INIT_LIST_HEAD(&cmd->list); | |
219 | spin_lock_irqsave(&dev->list_lock, flags); | |
220 | list_add_tail(&cmd->list, &dev->cmd_list); | |
221 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 222 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
223 | } else |
224 | put_device(&dev->sdev_gendev); | |
225 | ||
226 | return cmd; | |
b58d9154 | 227 | } |
1da177e4 LT |
228 | EXPORT_SYMBOL(scsi_get_command); |
229 | ||
eb44820c RL |
230 | /** |
231 | * __scsi_put_command - Free a struct scsi_cmnd | |
232 | * @shost: dev->host | |
233 | * @cmd: Command to free | |
234 | * @dev: parent scsi device | |
235 | */ | |
b58d9154 FT |
236 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
237 | struct device *dev) | |
238 | { | |
239 | unsigned long flags; | |
240 | ||
241 | /* changing locks here, don't need to restore the irq state */ | |
242 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
243 | if (unlikely(list_empty(&shost->free_list))) { | |
244 | list_add(&cmd->list, &shost->free_list); | |
245 | cmd = NULL; | |
246 | } | |
247 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
248 | ||
249 | if (likely(cmd != NULL)) | |
250 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
251 | ||
252 | put_device(dev); | |
253 | } | |
254 | EXPORT_SYMBOL(__scsi_put_command); | |
255 | ||
eb44820c RL |
256 | /** |
257 | * scsi_put_command - Free a scsi command block | |
258 | * @cmd: command block to free | |
1da177e4 LT |
259 | * |
260 | * Returns: Nothing. | |
261 | * | |
262 | * Notes: The command must not belong to any lists. | |
263 | */ | |
264 | void scsi_put_command(struct scsi_cmnd *cmd) | |
265 | { | |
266 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 267 | unsigned long flags; |
b58d9154 | 268 | |
1da177e4 LT |
269 | /* serious error if the command hasn't come from a device list */ |
270 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
271 | BUG_ON(list_empty(&cmd->list)); | |
272 | list_del_init(&cmd->list); | |
b58d9154 | 273 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 274 | |
b58d9154 | 275 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
276 | } |
277 | EXPORT_SYMBOL(scsi_put_command); | |
278 | ||
eb44820c RL |
279 | /** |
280 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. | |
281 | * @shost: host to allocate the freelist for. | |
1da177e4 | 282 | * |
eb44820c RL |
283 | * Description: The command freelist protects against system-wide out of memory |
284 | * deadlock by preallocating one SCSI command structure for each host, so the | |
285 | * system can always write to a swap file on a device associated with that host. | |
1da177e4 LT |
286 | * |
287 | * Returns: Nothing. | |
288 | */ | |
289 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
290 | { | |
291 | struct scsi_host_cmd_pool *pool; | |
292 | struct scsi_cmnd *cmd; | |
293 | ||
294 | spin_lock_init(&shost->free_list_lock); | |
295 | INIT_LIST_HEAD(&shost->free_list); | |
296 | ||
297 | /* | |
298 | * Select a command slab for this host and create it if not | |
eb44820c | 299 | * yet existent. |
1da177e4 | 300 | */ |
0b950672 | 301 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
302 | pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool); |
303 | if (!pool->users) { | |
304 | pool->slab = kmem_cache_create(pool->name, | |
305 | sizeof(struct scsi_cmnd), 0, | |
20c2df83 | 306 | pool->slab_flags, NULL); |
1da177e4 LT |
307 | if (!pool->slab) |
308 | goto fail; | |
309 | } | |
310 | ||
311 | pool->users++; | |
312 | shost->cmd_pool = pool; | |
0b950672 | 313 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
314 | |
315 | /* | |
316 | * Get one backup command for this host. | |
317 | */ | |
318 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
319 | GFP_KERNEL | shost->cmd_pool->gfp_mask); | |
320 | if (!cmd) | |
321 | goto fail2; | |
166a7287 | 322 | list_add(&cmd->list, &shost->free_list); |
1da177e4 LT |
323 | return 0; |
324 | ||
325 | fail2: | |
166a7287 | 326 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
327 | if (!--pool->users) |
328 | kmem_cache_destroy(pool->slab); | |
1da177e4 | 329 | fail: |
0b950672 | 330 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 | 331 | return -ENOMEM; |
1da177e4 LT |
332 | } |
333 | ||
eb44820c RL |
334 | /** |
335 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. | |
336 | * @shost: host whose freelist is going to be destroyed | |
1da177e4 LT |
337 | */ |
338 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
339 | { | |
340 | while (!list_empty(&shost->free_list)) { | |
341 | struct scsi_cmnd *cmd; | |
342 | ||
343 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
344 | list_del_init(&cmd->list); | |
345 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
346 | } | |
347 | ||
0b950672 | 348 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
349 | if (!--shost->cmd_pool->users) |
350 | kmem_cache_destroy(shost->cmd_pool->slab); | |
0b950672 | 351 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
352 | } |
353 | ||
354 | #ifdef CONFIG_SCSI_LOGGING | |
355 | void scsi_log_send(struct scsi_cmnd *cmd) | |
356 | { | |
357 | unsigned int level; | |
1da177e4 LT |
358 | |
359 | /* | |
360 | * If ML QUEUE log level is greater than or equal to: | |
361 | * | |
362 | * 1: nothing (match completion) | |
363 | * | |
364 | * 2: log opcode + command of all commands | |
365 | * | |
366 | * 3: same as 2 plus dump cmd address | |
367 | * | |
368 | * 4: same as 3 plus dump extra junk | |
369 | */ | |
370 | if (unlikely(scsi_logging_level)) { | |
371 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
372 | SCSI_LOG_MLQUEUE_BITS); | |
373 | if (level > 1) { | |
a4d04a4c | 374 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
375 | if (level > 2) |
376 | printk("0x%p ", cmd); | |
a4d04a4c | 377 | printk("\n"); |
1da177e4 LT |
378 | scsi_print_command(cmd); |
379 | if (level > 3) { | |
380 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
7b3d9545 | 381 | " queuecommand 0x%p\n", |
a73e45b3 | 382 | scsi_sglist(cmd), scsi_bufflen(cmd), |
a4d04a4c | 383 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
384 | |
385 | } | |
386 | } | |
387 | } | |
388 | } | |
389 | ||
390 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
391 | { | |
392 | unsigned int level; | |
1da177e4 LT |
393 | |
394 | /* | |
395 | * If ML COMPLETE log level is greater than or equal to: | |
396 | * | |
397 | * 1: log disposition, result, opcode + command, and conditionally | |
398 | * sense data for failures or non SUCCESS dispositions. | |
399 | * | |
400 | * 2: same as 1 but for all command completions. | |
401 | * | |
402 | * 3: same as 2 plus dump cmd address | |
403 | * | |
404 | * 4: same as 3 plus dump extra junk | |
405 | */ | |
406 | if (unlikely(scsi_logging_level)) { | |
407 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
408 | SCSI_LOG_MLCOMPLETE_BITS); | |
409 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
410 | (level > 1)) { | |
a4d04a4c | 411 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
412 | if (level > 2) |
413 | printk("0x%p ", cmd); | |
414 | /* | |
415 | * Dump truncated values, so we usually fit within | |
416 | * 80 chars. | |
417 | */ | |
418 | switch (disposition) { | |
419 | case SUCCESS: | |
a4d04a4c | 420 | printk("SUCCESS\n"); |
1da177e4 LT |
421 | break; |
422 | case NEEDS_RETRY: | |
a4d04a4c | 423 | printk("RETRY\n"); |
1da177e4 LT |
424 | break; |
425 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 426 | printk("MLQUEUE\n"); |
1da177e4 LT |
427 | break; |
428 | case FAILED: | |
a4d04a4c | 429 | printk("FAILED\n"); |
1da177e4 LT |
430 | break; |
431 | case TIMEOUT_ERROR: | |
432 | /* | |
433 | * If called via scsi_times_out. | |
434 | */ | |
a4d04a4c | 435 | printk("TIMEOUT\n"); |
1da177e4 LT |
436 | break; |
437 | default: | |
a4d04a4c | 438 | printk("UNKNOWN\n"); |
1da177e4 | 439 | } |
a4d04a4c | 440 | scsi_print_result(cmd); |
1da177e4 | 441 | scsi_print_command(cmd); |
a4d04a4c | 442 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 443 | scsi_print_sense("", cmd); |
a4d04a4c MP |
444 | if (level > 3) |
445 | scmd_printk(KERN_INFO, cmd, | |
446 | "scsi host busy %d failed %d\n", | |
447 | cmd->device->host->host_busy, | |
448 | cmd->device->host->host_failed); | |
1da177e4 LT |
449 | } |
450 | } | |
451 | } | |
452 | #endif | |
453 | ||
eb44820c RL |
454 | /** |
455 | * scsi_cmd_get_serial - Assign a serial number to a command | |
456 | * @host: the scsi host | |
457 | * @cmd: command to assign serial number to | |
458 | * | |
459 | * Description: a serial number identifies a request for error recovery | |
1da177e4 LT |
460 | * and debugging purposes. Protected by the Host_Lock of host. |
461 | */ | |
462 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
463 | { | |
464 | cmd->serial_number = host->cmd_serial_number++; | |
465 | if (cmd->serial_number == 0) | |
466 | cmd->serial_number = host->cmd_serial_number++; | |
1da177e4 LT |
467 | } |
468 | ||
eb44820c RL |
469 | /** |
470 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
471 | * @cmd: command block we are dispatching. | |
1da177e4 | 472 | * |
eb44820c RL |
473 | * Return: nonzero return request was rejected and device's queue needs to be |
474 | * plugged. | |
1da177e4 LT |
475 | */ |
476 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
477 | { | |
478 | struct Scsi_Host *host = cmd->device->host; | |
479 | unsigned long flags = 0; | |
480 | unsigned long timeout; | |
481 | int rtn = 0; | |
482 | ||
483 | /* check if the device is still usable */ | |
484 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
485 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
486 | * returns an immediate error upwards, and signals | |
487 | * that the device is no longer present */ | |
488 | cmd->result = DID_NO_CONNECT << 16; | |
489 | atomic_inc(&cmd->device->iorequest_cnt); | |
69b52893 | 490 | __scsi_done(cmd); |
1da177e4 LT |
491 | /* return 0 (because the command has been processed) */ |
492 | goto out; | |
493 | } | |
494 | ||
495 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
496 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
497 | /* | |
498 | * in SDEV_BLOCK, the command is just put back on the device | |
499 | * queue. The suspend state has already blocked the queue so | |
500 | * future requests should not occur until the device | |
501 | * transitions out of the suspend state. | |
502 | */ | |
503 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
504 | ||
505 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
506 | ||
507 | /* | |
508 | * NOTE: rtn is still zero here because we don't need the | |
509 | * queue to be plugged on return (it's already stopped) | |
510 | */ | |
511 | goto out; | |
512 | } | |
513 | ||
514 | /* | |
515 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
516 | */ | |
4d7db04a JB |
517 | if (cmd->device->scsi_level <= SCSI_2 && |
518 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
519 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
520 | (cmd->device->lun << 5 & 0xe0); | |
521 | } | |
522 | ||
523 | /* | |
524 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
525 | * we can avoid the drive not being ready. | |
526 | */ | |
527 | timeout = host->last_reset + MIN_RESET_DELAY; | |
528 | ||
529 | if (host->resetting && time_before(jiffies, timeout)) { | |
530 | int ticks_remaining = timeout - jiffies; | |
531 | /* | |
532 | * NOTE: This may be executed from within an interrupt | |
533 | * handler! This is bad, but for now, it'll do. The irq | |
534 | * level of the interrupt handler has been masked out by the | |
535 | * platform dependent interrupt handling code already, so the | |
536 | * sti() here will not cause another call to the SCSI host's | |
537 | * interrupt handler (assuming there is one irq-level per | |
538 | * host). | |
539 | */ | |
540 | while (--ticks_remaining >= 0) | |
541 | mdelay(1 + 999 / HZ); | |
542 | host->resetting = 0; | |
543 | } | |
544 | ||
545 | /* | |
546 | * AK: unlikely race here: for some reason the timer could | |
547 | * expire before the serial number is set up below. | |
548 | */ | |
549 | scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out); | |
550 | ||
551 | scsi_log_send(cmd); | |
552 | ||
553 | /* | |
554 | * We will use a queued command if possible, otherwise we will | |
555 | * emulate the queuing and calling of completion function ourselves. | |
556 | */ | |
1da177e4 LT |
557 | atomic_inc(&cmd->device->iorequest_cnt); |
558 | ||
559 | /* | |
560 | * Before we queue this command, check if the command | |
561 | * length exceeds what the host adapter can handle. | |
562 | */ | |
563 | if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) { | |
564 | SCSI_LOG_MLQUEUE(3, | |
565 | printk("queuecommand : command too long.\n")); | |
566 | cmd->result = (DID_ABORT << 16); | |
567 | ||
568 | scsi_done(cmd); | |
569 | goto out; | |
570 | } | |
571 | ||
572 | spin_lock_irqsave(host->host_lock, flags); | |
573 | scsi_cmd_get_serial(host, cmd); | |
574 | ||
d2c9d9ea | 575 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
576 | cmd->result = (DID_NO_CONNECT << 16); |
577 | scsi_done(cmd); | |
578 | } else { | |
579 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
580 | } | |
581 | spin_unlock_irqrestore(host->host_lock, flags); | |
582 | if (rtn) { | |
d8c37e7b TH |
583 | if (scsi_delete_timer(cmd)) { |
584 | atomic_inc(&cmd->device->iodone_cnt); | |
585 | scsi_queue_insert(cmd, | |
586 | (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? | |
587 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
588 | } | |
1da177e4 LT |
589 | SCSI_LOG_MLQUEUE(3, |
590 | printk("queuecommand : request rejected\n")); | |
591 | } | |
592 | ||
593 | out: | |
594 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
595 | return rtn; | |
596 | } | |
597 | ||
89f48c4d LT |
598 | /** |
599 | * scsi_req_abort_cmd -- Request command recovery for the specified command | |
eb44820c | 600 | * @cmd: pointer to the SCSI command of interest |
89f48c4d LT |
601 | * |
602 | * This function requests that SCSI Core start recovery for the | |
603 | * command by deleting the timer and adding the command to the eh | |
604 | * queue. It can be called by either LLDDs or SCSI Core. LLDDs who | |
605 | * implement their own error recovery MAY ignore the timeout event if | |
606 | * they generated scsi_req_abort_cmd. | |
607 | */ | |
608 | void scsi_req_abort_cmd(struct scsi_cmnd *cmd) | |
609 | { | |
610 | if (!scsi_delete_timer(cmd)) | |
611 | return; | |
612 | scsi_times_out(cmd); | |
613 | } | |
614 | EXPORT_SYMBOL(scsi_req_abort_cmd); | |
615 | ||
1da177e4 LT |
616 | /** |
617 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
618 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
619 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
620 | * | |
eb44820c RL |
621 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
622 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
623 | * enqueues the command to the done queue for further processing. | |
1da177e4 LT |
624 | * |
625 | * This is the producer of the done queue who enqueues at the tail. | |
626 | * | |
627 | * This function is interrupt context safe. | |
628 | */ | |
52c1da39 | 629 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 LT |
630 | { |
631 | /* | |
eb44820c | 632 | * We don't have to worry about this one timing out anymore. |
1da177e4 LT |
633 | * If we are unable to remove the timer, then the command |
634 | * has already timed out. In which case, we have no choice but to | |
635 | * let the timeout function run, as we have no idea where in fact | |
636 | * that function could really be. It might be on another processor, | |
637 | * etc, etc. | |
638 | */ | |
639 | if (!scsi_delete_timer(cmd)) | |
640 | return; | |
641 | __scsi_done(cmd); | |
642 | } | |
643 | ||
644 | /* Private entry to scsi_done() to complete a command when the timer | |
645 | * isn't running --- used by scsi_times_out */ | |
646 | void __scsi_done(struct scsi_cmnd *cmd) | |
647 | { | |
1aea6434 | 648 | struct request *rq = cmd->request; |
1da177e4 LT |
649 | |
650 | /* | |
651 | * Set the serial numbers back to zero | |
652 | */ | |
653 | cmd->serial_number = 0; | |
1da177e4 LT |
654 | |
655 | atomic_inc(&cmd->device->iodone_cnt); | |
656 | if (cmd->result) | |
657 | atomic_inc(&cmd->device->ioerr_cnt); | |
658 | ||
1aea6434 JA |
659 | BUG_ON(!rq); |
660 | ||
1da177e4 | 661 | /* |
1aea6434 JA |
662 | * The uptodate/nbytes values don't matter, as we allow partial |
663 | * completes and thus will check this in the softirq callback | |
1da177e4 | 664 | */ |
1aea6434 JA |
665 | rq->completion_data = cmd; |
666 | blk_complete_request(rq); | |
1da177e4 LT |
667 | } |
668 | ||
7b3d9545 LT |
669 | /* Move this to a header if it becomes more generally useful */ |
670 | static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) | |
671 | { | |
672 | return *(struct scsi_driver **)cmd->request->rq_disk->private_data; | |
673 | } | |
674 | ||
eb44820c RL |
675 | /** |
676 | * scsi_finish_command - cleanup and pass command back to upper layer | |
677 | * @cmd: the command | |
1da177e4 | 678 | * |
eb44820c | 679 | * Description: Pass command off to upper layer for finishing of I/O |
1da177e4 LT |
680 | * request, waking processes that are waiting on results, |
681 | * etc. | |
682 | */ | |
683 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
684 | { | |
685 | struct scsi_device *sdev = cmd->device; | |
686 | struct Scsi_Host *shost = sdev->host; | |
7b3d9545 LT |
687 | struct scsi_driver *drv; |
688 | unsigned int good_bytes; | |
1da177e4 LT |
689 | |
690 | scsi_device_unbusy(sdev); | |
691 | ||
692 | /* | |
693 | * Clear the flags which say that the device/host is no longer | |
694 | * capable of accepting new commands. These are set in scsi_queue.c | |
695 | * for both the queue full condition on a device, and for a | |
696 | * host full condition on the host. | |
697 | * | |
698 | * XXX(hch): What about locking? | |
699 | */ | |
700 | shost->host_blocked = 0; | |
701 | sdev->device_blocked = 0; | |
702 | ||
703 | /* | |
704 | * If we have valid sense information, then some kind of recovery | |
705 | * must have taken place. Make a note of this. | |
706 | */ | |
707 | if (SCSI_SENSE_VALID(cmd)) | |
708 | cmd->result |= (DRIVER_SENSE << 24); | |
709 | ||
3bf743e7 JG |
710 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
711 | "Notifying upper driver of completion " | |
712 | "(result %x)\n", cmd->result)); | |
1da177e4 | 713 | |
7b3d9545 LT |
714 | good_bytes = cmd->request_bufflen; |
715 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { | |
716 | drv = scsi_cmd_to_driver(cmd); | |
717 | if (drv->done) | |
718 | good_bytes = drv->done(cmd); | |
719 | } | |
720 | scsi_io_completion(cmd, good_bytes); | |
1da177e4 LT |
721 | } |
722 | EXPORT_SYMBOL(scsi_finish_command); | |
723 | ||
eb44820c RL |
724 | /** |
725 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth | |
726 | * @sdev: SCSI Device in question | |
727 | * @tagged: Do we use tagged queueing (non-0) or do we treat | |
728 | * this device as an untagged device (0) | |
729 | * @tags: Number of tags allowed if tagged queueing enabled, | |
730 | * or number of commands the low level driver can | |
731 | * queue up in non-tagged mode (as per cmd_per_lun). | |
1da177e4 LT |
732 | * |
733 | * Returns: Nothing | |
734 | * | |
735 | * Lock Status: None held on entry | |
736 | * | |
737 | * Notes: Low level drivers may call this at any time and we will do | |
738 | * the right thing depending on whether or not the device is | |
739 | * currently active and whether or not it even has the | |
740 | * command blocks built yet. | |
741 | */ | |
742 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
743 | { | |
744 | unsigned long flags; | |
745 | ||
746 | /* | |
747 | * refuse to set tagged depth to an unworkable size | |
748 | */ | |
749 | if (tags <= 0) | |
750 | return; | |
751 | ||
752 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
753 | ||
eb44820c RL |
754 | /* Check to see if the queue is managed by the block layer. |
755 | * If it is, and we fail to adjust the depth, exit. */ | |
1da177e4 LT |
756 | if (blk_queue_tagged(sdev->request_queue) && |
757 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
758 | goto out; | |
759 | ||
760 | sdev->queue_depth = tags; | |
761 | switch (tagged) { | |
762 | case MSG_ORDERED_TAG: | |
763 | sdev->ordered_tags = 1; | |
764 | sdev->simple_tags = 1; | |
765 | break; | |
766 | case MSG_SIMPLE_TAG: | |
767 | sdev->ordered_tags = 0; | |
768 | sdev->simple_tags = 1; | |
769 | break; | |
770 | default: | |
9ccfc756 JB |
771 | sdev_printk(KERN_WARNING, sdev, |
772 | "scsi_adjust_queue_depth, bad queue type, " | |
773 | "disabled\n"); | |
1da177e4 LT |
774 | case 0: |
775 | sdev->ordered_tags = sdev->simple_tags = 0; | |
776 | sdev->queue_depth = tags; | |
777 | break; | |
778 | } | |
779 | out: | |
780 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
781 | } | |
782 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
783 | ||
eb44820c RL |
784 | /** |
785 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth | |
786 | * @sdev: SCSI Device in question | |
787 | * @depth: Current number of outstanding SCSI commands on this device, | |
788 | * not counting the one returned as QUEUE_FULL. | |
1da177e4 | 789 | * |
eb44820c | 790 | * Description: This function will track successive QUEUE_FULL events on a |
1da177e4 LT |
791 | * specific SCSI device to determine if and when there is a |
792 | * need to adjust the queue depth on the device. | |
793 | * | |
eb44820c | 794 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
1da177e4 LT |
795 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
796 | * as the untagged command depth | |
797 | * | |
798 | * Lock Status: None held on entry | |
799 | * | |
800 | * Notes: Low level drivers may call this at any time and we will do | |
801 | * "The Right Thing." We are interrupt context safe. | |
802 | */ | |
803 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
804 | { | |
805 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
806 | return 0; | |
807 | ||
808 | sdev->last_queue_full_time = (jiffies >> 4); | |
809 | if (sdev->last_queue_full_depth != depth) { | |
810 | sdev->last_queue_full_count = 1; | |
811 | sdev->last_queue_full_depth = depth; | |
812 | } else { | |
813 | sdev->last_queue_full_count++; | |
814 | } | |
815 | ||
816 | if (sdev->last_queue_full_count <= 10) | |
817 | return 0; | |
818 | if (sdev->last_queue_full_depth < 8) { | |
819 | /* Drop back to untagged */ | |
820 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
821 | return -1; | |
822 | } | |
823 | ||
824 | if (sdev->ordered_tags) | |
825 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
826 | else | |
827 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
828 | return depth; | |
829 | } | |
830 | EXPORT_SYMBOL(scsi_track_queue_full); | |
831 | ||
832 | /** | |
eb44820c | 833 | * scsi_device_get - get an additional reference to a scsi_device |
1da177e4 LT |
834 | * @sdev: device to get a reference to |
835 | * | |
eb44820c | 836 | * Description: Gets a reference to the scsi_device and increments the use count |
1da177e4 LT |
837 | * of the underlying LLDD module. You must hold host_lock of the |
838 | * parent Scsi_Host or already have a reference when calling this. | |
839 | */ | |
840 | int scsi_device_get(struct scsi_device *sdev) | |
841 | { | |
85b6c720 | 842 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
843 | return -ENXIO; |
844 | if (!get_device(&sdev->sdev_gendev)) | |
845 | return -ENXIO; | |
85b6c720 JB |
846 | /* We can fail this if we're doing SCSI operations |
847 | * from module exit (like cache flush) */ | |
848 | try_module_get(sdev->host->hostt->module); | |
849 | ||
1da177e4 LT |
850 | return 0; |
851 | } | |
852 | EXPORT_SYMBOL(scsi_device_get); | |
853 | ||
854 | /** | |
855 | * scsi_device_put - release a reference to a scsi_device | |
856 | * @sdev: device to release a reference on. | |
857 | * | |
eb44820c RL |
858 | * Description: Release a reference to the scsi_device and decrements the use |
859 | * count of the underlying LLDD module. The device is freed once the last | |
1da177e4 LT |
860 | * user vanishes. |
861 | */ | |
862 | void scsi_device_put(struct scsi_device *sdev) | |
863 | { | |
504fb37a | 864 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
865 | struct module *module = sdev->host->hostt->module; |
866 | ||
85b6c720 JB |
867 | /* The module refcount will be zero if scsi_device_get() |
868 | * was called from a module removal routine */ | |
f479ab87 JB |
869 | if (module && module_refcount(module) != 0) |
870 | module_put(module); | |
a506b44b | 871 | #endif |
1da177e4 LT |
872 | put_device(&sdev->sdev_gendev); |
873 | } | |
874 | EXPORT_SYMBOL(scsi_device_put); | |
875 | ||
eb44820c | 876 | /* helper for shost_for_each_device, see that for documentation */ |
1da177e4 LT |
877 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
878 | struct scsi_device *prev) | |
879 | { | |
880 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
881 | struct scsi_device *next = NULL; | |
882 | unsigned long flags; | |
883 | ||
884 | spin_lock_irqsave(shost->host_lock, flags); | |
885 | while (list->next != &shost->__devices) { | |
886 | next = list_entry(list->next, struct scsi_device, siblings); | |
887 | /* skip devices that we can't get a reference to */ | |
888 | if (!scsi_device_get(next)) | |
889 | break; | |
890 | next = NULL; | |
891 | list = list->next; | |
892 | } | |
893 | spin_unlock_irqrestore(shost->host_lock, flags); | |
894 | ||
895 | if (prev) | |
896 | scsi_device_put(prev); | |
897 | return next; | |
898 | } | |
899 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
900 | ||
901 | /** | |
902 | * starget_for_each_device - helper to walk all devices of a target | |
903 | * @starget: target whose devices we want to iterate over. | |
eb44820c RL |
904 | * @data: Opaque passed to each function call. |
905 | * @fn: Function to call on each device | |
1da177e4 | 906 | * |
522939d4 | 907 | * This traverses over each device of @starget. The devices have |
1da177e4 LT |
908 | * a reference that must be released by scsi_host_put when breaking |
909 | * out of the loop. | |
910 | */ | |
522939d4 | 911 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1da177e4 LT |
912 | void (*fn)(struct scsi_device *, void *)) |
913 | { | |
914 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
915 | struct scsi_device *sdev; | |
916 | ||
917 | shost_for_each_device(sdev, shost) { | |
918 | if ((sdev->channel == starget->channel) && | |
919 | (sdev->id == starget->id)) | |
920 | fn(sdev, data); | |
921 | } | |
922 | } | |
923 | EXPORT_SYMBOL(starget_for_each_device); | |
924 | ||
522939d4 MR |
925 | /** |
926 | * __starget_for_each_device - helper to walk all devices of a target | |
927 | * (UNLOCKED) | |
928 | * @starget: target whose devices we want to iterate over. | |
929 | * | |
930 | * This traverses over each device of @starget. It does _not_ | |
931 | * take a reference on the scsi_device, so the whole loop must be | |
932 | * protected by shost->host_lock. | |
933 | * | |
934 | * Note: The only reason why drivers would want to use this is because | |
935 | * they need to access the device list in irq context. Otherwise you | |
936 | * really want to use starget_for_each_device instead. | |
937 | **/ | |
938 | void __starget_for_each_device(struct scsi_target *starget, void *data, | |
939 | void (*fn)(struct scsi_device *, void *)) | |
940 | { | |
941 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
942 | struct scsi_device *sdev; | |
943 | ||
944 | __shost_for_each_device(sdev, shost) { | |
945 | if ((sdev->channel == starget->channel) && | |
946 | (sdev->id == starget->id)) | |
947 | fn(sdev, data); | |
948 | } | |
949 | } | |
950 | EXPORT_SYMBOL(__starget_for_each_device); | |
951 | ||
1da177e4 LT |
952 | /** |
953 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
954 | * @starget: SCSI target pointer | |
955 | * @lun: SCSI Logical Unit Number | |
956 | * | |
eb44820c RL |
957 | * Description: Looks up the scsi_device with the specified @lun for a given |
958 | * @starget. The returned scsi_device does not have an additional | |
1da177e4 LT |
959 | * reference. You must hold the host's host_lock over this call and |
960 | * any access to the returned scsi_device. | |
961 | * | |
dc8875e1 | 962 | * Note: The only reason why drivers should use this is because |
eb44820c | 963 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
964 | * really want to use scsi_device_lookup_by_target instead. |
965 | **/ | |
966 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
967 | uint lun) | |
968 | { | |
969 | struct scsi_device *sdev; | |
970 | ||
971 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
972 | if (sdev->lun ==lun) | |
973 | return sdev; | |
974 | } | |
975 | ||
976 | return NULL; | |
977 | } | |
978 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
979 | ||
980 | /** | |
981 | * scsi_device_lookup_by_target - find a device given the target | |
982 | * @starget: SCSI target pointer | |
983 | * @lun: SCSI Logical Unit Number | |
984 | * | |
eb44820c RL |
985 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
986 | * for a given host. The returned scsi_device has an additional reference that | |
987 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
988 | **/ |
989 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
990 | uint lun) | |
991 | { | |
992 | struct scsi_device *sdev; | |
993 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
994 | unsigned long flags; | |
995 | ||
996 | spin_lock_irqsave(shost->host_lock, flags); | |
997 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
998 | if (sdev && scsi_device_get(sdev)) | |
999 | sdev = NULL; | |
1000 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1001 | ||
1002 | return sdev; | |
1003 | } | |
1004 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1005 | ||
1006 | /** | |
eb44820c | 1007 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1da177e4 LT |
1008 | * @shost: SCSI host pointer |
1009 | * @channel: SCSI channel (zero if only one channel) | |
eb44820c | 1010 | * @id: SCSI target number (physical unit number) |
1da177e4 LT |
1011 | * @lun: SCSI Logical Unit Number |
1012 | * | |
eb44820c RL |
1013 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1014 | * for a given host. The returned scsi_device does not have an additional | |
1015 | * reference. You must hold the host's host_lock over this call and any access | |
1016 | * to the returned scsi_device. | |
1da177e4 LT |
1017 | * |
1018 | * Note: The only reason why drivers would want to use this is because | |
eb44820c | 1019 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1020 | * really want to use scsi_device_lookup instead. |
1021 | **/ | |
1022 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1023 | uint channel, uint id, uint lun) | |
1024 | { | |
1025 | struct scsi_device *sdev; | |
1026 | ||
1027 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1028 | if (sdev->channel == channel && sdev->id == id && | |
1029 | sdev->lun ==lun) | |
1030 | return sdev; | |
1031 | } | |
1032 | ||
1033 | return NULL; | |
1034 | } | |
1035 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1036 | ||
1037 | /** | |
1038 | * scsi_device_lookup - find a device given the host | |
1039 | * @shost: SCSI host pointer | |
1040 | * @channel: SCSI channel (zero if only one channel) | |
1041 | * @id: SCSI target number (physical unit number) | |
1042 | * @lun: SCSI Logical Unit Number | |
1043 | * | |
eb44820c RL |
1044 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1045 | * for a given host. The returned scsi_device has an additional reference that | |
1046 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1047 | **/ |
1048 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1049 | uint channel, uint id, uint lun) | |
1050 | { | |
1051 | struct scsi_device *sdev; | |
1052 | unsigned long flags; | |
1053 | ||
1054 | spin_lock_irqsave(shost->host_lock, flags); | |
1055 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1056 | if (sdev && scsi_device_get(sdev)) | |
1057 | sdev = NULL; | |
1058 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1059 | ||
1060 | return sdev; | |
1061 | } | |
1062 | EXPORT_SYMBOL(scsi_device_lookup); | |
1063 | ||
1da177e4 LT |
1064 | MODULE_DESCRIPTION("SCSI core"); |
1065 | MODULE_LICENSE("GPL"); | |
1066 | ||
1067 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1068 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1069 | ||
1070 | static int __init init_scsi(void) | |
1071 | { | |
9bf09c23 | 1072 | int error; |
1da177e4 LT |
1073 | |
1074 | error = scsi_init_queue(); | |
1075 | if (error) | |
1076 | return error; | |
1077 | error = scsi_init_procfs(); | |
1078 | if (error) | |
1079 | goto cleanup_queue; | |
1080 | error = scsi_init_devinfo(); | |
1081 | if (error) | |
1082 | goto cleanup_procfs; | |
1083 | error = scsi_init_hosts(); | |
1084 | if (error) | |
1085 | goto cleanup_devlist; | |
1086 | error = scsi_init_sysctl(); | |
1087 | if (error) | |
1088 | goto cleanup_hosts; | |
1089 | error = scsi_sysfs_register(); | |
1090 | if (error) | |
1091 | goto cleanup_sysctl; | |
1092 | ||
84314fd4 JS |
1093 | scsi_netlink_init(); |
1094 | ||
1da177e4 LT |
1095 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1096 | return 0; | |
1097 | ||
1098 | cleanup_sysctl: | |
1099 | scsi_exit_sysctl(); | |
1100 | cleanup_hosts: | |
1101 | scsi_exit_hosts(); | |
1102 | cleanup_devlist: | |
1103 | scsi_exit_devinfo(); | |
1104 | cleanup_procfs: | |
1105 | scsi_exit_procfs(); | |
1106 | cleanup_queue: | |
1107 | scsi_exit_queue(); | |
1108 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1109 | -error); | |
1110 | return error; | |
1111 | } | |
1112 | ||
1113 | static void __exit exit_scsi(void) | |
1114 | { | |
84314fd4 | 1115 | scsi_netlink_exit(); |
1da177e4 LT |
1116 | scsi_sysfs_unregister(); |
1117 | scsi_exit_sysctl(); | |
1118 | scsi_exit_hosts(); | |
1119 | scsi_exit_devinfo(); | |
1da177e4 LT |
1120 | scsi_exit_procfs(); |
1121 | scsi_exit_queue(); | |
1da177e4 LT |
1122 | } |
1123 | ||
1124 | subsys_initcall(init_scsi); | |
1125 | module_exit(exit_scsi); |