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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 { |
5b7f1680 JB |
144 | 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; | |
1da177e4 LT |
151 | }; |
152 | ||
153 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
5b7f1680 JB |
154 | .cmd_name = "scsi_cmd_cache", |
155 | .sense_name = "scsi_sense_cache", | |
1da177e4 LT |
156 | .slab_flags = SLAB_HWCACHE_ALIGN, |
157 | }; | |
158 | ||
159 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
5b7f1680 JB |
160 | .cmd_name = "scsi_cmd_cache(DMA)", |
161 | .sense_name = "scsi_sense_cache(DMA)", | |
1da177e4 LT |
162 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, |
163 | .gfp_mask = __GFP_DMA, | |
164 | }; | |
165 | ||
0b950672 | 166 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 167 | |
eb44820c RL |
168 | /** |
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 | */ | |
b58d9154 | 176 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 LT |
177 | { |
178 | struct scsi_cmnd *cmd; | |
de25deb1 | 179 | unsigned char *buf; |
1da177e4 | 180 | |
5b7f1680 JB |
181 | cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab, |
182 | gfp_mask | shost->cmd_pool->gfp_mask); | |
1da177e4 | 183 | |
164fc5dc HD |
184 | if (likely(cmd)) { |
185 | buf = kmem_cache_alloc(shost->cmd_pool->sense_slab, | |
186 | gfp_mask | shost->cmd_pool->gfp_mask); | |
187 | if (likely(buf)) { | |
188 | memset(cmd, 0, sizeof(*cmd)); | |
189 | cmd->sense_buffer = buf; | |
190 | } else { | |
191 | kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); | |
192 | cmd = NULL; | |
193 | } | |
194 | } | |
195 | ||
1da177e4 LT |
196 | if (unlikely(!cmd)) { |
197 | unsigned long flags; | |
198 | ||
199 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
200 | if (likely(!list_empty(&shost->free_list))) { | |
201 | cmd = list_entry(shost->free_list.next, | |
202 | struct scsi_cmnd, list); | |
203 | list_del_init(&cmd->list); | |
204 | } | |
205 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
de25deb1 FT |
206 | |
207 | if (cmd) { | |
208 | buf = cmd->sense_buffer; | |
209 | memset(cmd, 0, sizeof(*cmd)); | |
210 | cmd->sense_buffer = buf; | |
211 | } | |
1da177e4 LT |
212 | } |
213 | ||
214 | return cmd; | |
215 | } | |
b58d9154 | 216 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 | 217 | |
eb44820c RL |
218 | /** |
219 | * scsi_get_command - Allocate and setup a scsi command block | |
220 | * @dev: parent scsi device | |
221 | * @gfp_mask: allocator flags | |
1da177e4 LT |
222 | * |
223 | * Returns: The allocated scsi command structure. | |
224 | */ | |
c53033f6 | 225 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
226 | { |
227 | struct scsi_cmnd *cmd; | |
228 | ||
229 | /* Bail if we can't get a reference to the device */ | |
230 | if (!get_device(&dev->sdev_gendev)) | |
231 | return NULL; | |
232 | ||
233 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
234 | ||
235 | if (likely(cmd != NULL)) { | |
236 | unsigned long flags; | |
237 | ||
1da177e4 | 238 | cmd->device = dev; |
1da177e4 LT |
239 | init_timer(&cmd->eh_timeout); |
240 | INIT_LIST_HEAD(&cmd->list); | |
241 | spin_lock_irqsave(&dev->list_lock, flags); | |
242 | list_add_tail(&cmd->list, &dev->cmd_list); | |
243 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 244 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
245 | } else |
246 | put_device(&dev->sdev_gendev); | |
247 | ||
248 | return cmd; | |
b58d9154 | 249 | } |
1da177e4 LT |
250 | EXPORT_SYMBOL(scsi_get_command); |
251 | ||
eb44820c RL |
252 | /** |
253 | * __scsi_put_command - Free a struct scsi_cmnd | |
254 | * @shost: dev->host | |
255 | * @cmd: Command to free | |
256 | * @dev: parent scsi device | |
257 | */ | |
b58d9154 FT |
258 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
259 | struct device *dev) | |
260 | { | |
261 | unsigned long flags; | |
262 | ||
263 | /* changing locks here, don't need to restore the irq state */ | |
264 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
265 | if (unlikely(list_empty(&shost->free_list))) { | |
266 | list_add(&cmd->list, &shost->free_list); | |
267 | cmd = NULL; | |
268 | } | |
269 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
270 | ||
de25deb1 | 271 | if (likely(cmd != NULL)) { |
5b7f1680 JB |
272 | kmem_cache_free(shost->cmd_pool->sense_slab, |
273 | cmd->sense_buffer); | |
274 | kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); | |
de25deb1 | 275 | } |
b58d9154 FT |
276 | |
277 | put_device(dev); | |
278 | } | |
279 | EXPORT_SYMBOL(__scsi_put_command); | |
280 | ||
eb44820c RL |
281 | /** |
282 | * scsi_put_command - Free a scsi command block | |
283 | * @cmd: command block to free | |
1da177e4 LT |
284 | * |
285 | * Returns: Nothing. | |
286 | * | |
287 | * Notes: The command must not belong to any lists. | |
288 | */ | |
289 | void scsi_put_command(struct scsi_cmnd *cmd) | |
290 | { | |
291 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 292 | unsigned long flags; |
b58d9154 | 293 | |
1da177e4 LT |
294 | /* serious error if the command hasn't come from a device list */ |
295 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
296 | BUG_ON(list_empty(&cmd->list)); | |
297 | list_del_init(&cmd->list); | |
b58d9154 | 298 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 299 | |
b58d9154 | 300 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
301 | } |
302 | EXPORT_SYMBOL(scsi_put_command); | |
303 | ||
eb44820c RL |
304 | /** |
305 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. | |
306 | * @shost: host to allocate the freelist for. | |
1da177e4 | 307 | * |
eb44820c RL |
308 | * Description: The command freelist protects against system-wide out of memory |
309 | * deadlock by preallocating one SCSI command structure for each host, so the | |
310 | * system can always write to a swap file on a device associated with that host. | |
1da177e4 LT |
311 | * |
312 | * Returns: Nothing. | |
313 | */ | |
314 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
315 | { | |
316 | struct scsi_host_cmd_pool *pool; | |
317 | struct scsi_cmnd *cmd; | |
318 | ||
319 | spin_lock_init(&shost->free_list_lock); | |
320 | INIT_LIST_HEAD(&shost->free_list); | |
321 | ||
322 | /* | |
323 | * Select a command slab for this host and create it if not | |
eb44820c | 324 | * yet existent. |
1da177e4 | 325 | */ |
0b950672 | 326 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
327 | pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool); |
328 | if (!pool->users) { | |
5b7f1680 JB |
329 | pool->cmd_slab = kmem_cache_create(pool->cmd_name, |
330 | sizeof(struct scsi_cmnd), 0, | |
331 | pool->slab_flags, NULL); | |
332 | if (!pool->cmd_slab) | |
333 | goto fail; | |
334 | ||
335 | pool->sense_slab = kmem_cache_create(pool->sense_name, | |
336 | SCSI_SENSE_BUFFERSIZE, 0, | |
337 | pool->slab_flags, NULL); | |
338 | if (!pool->sense_slab) { | |
339 | kmem_cache_destroy(pool->cmd_slab); | |
1da177e4 | 340 | goto fail; |
5b7f1680 | 341 | } |
1da177e4 LT |
342 | } |
343 | ||
344 | pool->users++; | |
345 | shost->cmd_pool = pool; | |
0b950672 | 346 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
347 | |
348 | /* | |
349 | * Get one backup command for this host. | |
350 | */ | |
5b7f1680 JB |
351 | cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab, |
352 | GFP_KERNEL | shost->cmd_pool->gfp_mask); | |
1da177e4 LT |
353 | if (!cmd) |
354 | goto fail2; | |
de25deb1 | 355 | |
5b7f1680 JB |
356 | cmd->sense_buffer = kmem_cache_alloc(shost->cmd_pool->sense_slab, |
357 | GFP_KERNEL | | |
358 | shost->cmd_pool->gfp_mask); | |
359 | if (!cmd->sense_buffer) | |
360 | goto fail2; | |
de25deb1 | 361 | |
166a7287 | 362 | list_add(&cmd->list, &shost->free_list); |
1da177e4 LT |
363 | return 0; |
364 | ||
365 | fail2: | |
5b7f1680 JB |
366 | if (cmd) |
367 | kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); | |
166a7287 | 368 | mutex_lock(&host_cmd_pool_mutex); |
5b7f1680 JB |
369 | if (!--pool->users) { |
370 | kmem_cache_destroy(pool->cmd_slab); | |
371 | kmem_cache_destroy(pool->sense_slab); | |
372 | } | |
1da177e4 | 373 | fail: |
0b950672 | 374 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 | 375 | return -ENOMEM; |
1da177e4 LT |
376 | } |
377 | ||
eb44820c RL |
378 | /** |
379 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. | |
380 | * @shost: host whose freelist is going to be destroyed | |
1da177e4 LT |
381 | */ |
382 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
383 | { | |
384 | while (!list_empty(&shost->free_list)) { | |
385 | struct scsi_cmnd *cmd; | |
386 | ||
387 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
388 | list_del_init(&cmd->list); | |
5b7f1680 JB |
389 | kmem_cache_free(shost->cmd_pool->sense_slab, |
390 | cmd->sense_buffer); | |
391 | kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); | |
1da177e4 LT |
392 | } |
393 | ||
0b950672 | 394 | mutex_lock(&host_cmd_pool_mutex); |
5b7f1680 JB |
395 | if (!--shost->cmd_pool->users) { |
396 | kmem_cache_destroy(shost->cmd_pool->cmd_slab); | |
397 | kmem_cache_destroy(shost->cmd_pool->sense_slab); | |
de25deb1 | 398 | } |
de25deb1 FT |
399 | mutex_unlock(&host_cmd_pool_mutex); |
400 | } | |
401 | ||
1da177e4 LT |
402 | #ifdef CONFIG_SCSI_LOGGING |
403 | void scsi_log_send(struct scsi_cmnd *cmd) | |
404 | { | |
405 | unsigned int level; | |
1da177e4 LT |
406 | |
407 | /* | |
408 | * If ML QUEUE log level is greater than or equal to: | |
409 | * | |
410 | * 1: nothing (match completion) | |
411 | * | |
412 | * 2: log opcode + command of all commands | |
413 | * | |
414 | * 3: same as 2 plus dump cmd address | |
415 | * | |
416 | * 4: same as 3 plus dump extra junk | |
417 | */ | |
418 | if (unlikely(scsi_logging_level)) { | |
419 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
420 | SCSI_LOG_MLQUEUE_BITS); | |
421 | if (level > 1) { | |
a4d04a4c | 422 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
423 | if (level > 2) |
424 | printk("0x%p ", cmd); | |
a4d04a4c | 425 | printk("\n"); |
1da177e4 LT |
426 | scsi_print_command(cmd); |
427 | if (level > 3) { | |
428 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
7b3d9545 | 429 | " queuecommand 0x%p\n", |
a73e45b3 | 430 | scsi_sglist(cmd), scsi_bufflen(cmd), |
a4d04a4c | 431 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
432 | |
433 | } | |
434 | } | |
435 | } | |
436 | } | |
437 | ||
438 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
439 | { | |
440 | unsigned int level; | |
1da177e4 LT |
441 | |
442 | /* | |
443 | * If ML COMPLETE log level is greater than or equal to: | |
444 | * | |
445 | * 1: log disposition, result, opcode + command, and conditionally | |
446 | * sense data for failures or non SUCCESS dispositions. | |
447 | * | |
448 | * 2: same as 1 but for all command completions. | |
449 | * | |
450 | * 3: same as 2 plus dump cmd address | |
451 | * | |
452 | * 4: same as 3 plus dump extra junk | |
453 | */ | |
454 | if (unlikely(scsi_logging_level)) { | |
455 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
456 | SCSI_LOG_MLCOMPLETE_BITS); | |
457 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
458 | (level > 1)) { | |
a4d04a4c | 459 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
460 | if (level > 2) |
461 | printk("0x%p ", cmd); | |
462 | /* | |
463 | * Dump truncated values, so we usually fit within | |
464 | * 80 chars. | |
465 | */ | |
466 | switch (disposition) { | |
467 | case SUCCESS: | |
a4d04a4c | 468 | printk("SUCCESS\n"); |
1da177e4 LT |
469 | break; |
470 | case NEEDS_RETRY: | |
a4d04a4c | 471 | printk("RETRY\n"); |
1da177e4 LT |
472 | break; |
473 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 474 | printk("MLQUEUE\n"); |
1da177e4 LT |
475 | break; |
476 | case FAILED: | |
a4d04a4c | 477 | printk("FAILED\n"); |
1da177e4 LT |
478 | break; |
479 | case TIMEOUT_ERROR: | |
480 | /* | |
481 | * If called via scsi_times_out. | |
482 | */ | |
a4d04a4c | 483 | printk("TIMEOUT\n"); |
1da177e4 LT |
484 | break; |
485 | default: | |
a4d04a4c | 486 | printk("UNKNOWN\n"); |
1da177e4 | 487 | } |
a4d04a4c | 488 | scsi_print_result(cmd); |
1da177e4 | 489 | scsi_print_command(cmd); |
a4d04a4c | 490 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 491 | scsi_print_sense("", cmd); |
a4d04a4c MP |
492 | if (level > 3) |
493 | scmd_printk(KERN_INFO, cmd, | |
494 | "scsi host busy %d failed %d\n", | |
495 | cmd->device->host->host_busy, | |
496 | cmd->device->host->host_failed); | |
1da177e4 LT |
497 | } |
498 | } | |
499 | } | |
500 | #endif | |
501 | ||
eb44820c RL |
502 | /** |
503 | * scsi_cmd_get_serial - Assign a serial number to a command | |
504 | * @host: the scsi host | |
505 | * @cmd: command to assign serial number to | |
506 | * | |
507 | * Description: a serial number identifies a request for error recovery | |
1da177e4 LT |
508 | * and debugging purposes. Protected by the Host_Lock of host. |
509 | */ | |
510 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
511 | { | |
512 | cmd->serial_number = host->cmd_serial_number++; | |
513 | if (cmd->serial_number == 0) | |
514 | cmd->serial_number = host->cmd_serial_number++; | |
1da177e4 LT |
515 | } |
516 | ||
eb44820c RL |
517 | /** |
518 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
519 | * @cmd: command block we are dispatching. | |
1da177e4 | 520 | * |
eb44820c RL |
521 | * Return: nonzero return request was rejected and device's queue needs to be |
522 | * plugged. | |
1da177e4 LT |
523 | */ |
524 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
525 | { | |
526 | struct Scsi_Host *host = cmd->device->host; | |
527 | unsigned long flags = 0; | |
528 | unsigned long timeout; | |
529 | int rtn = 0; | |
530 | ||
531 | /* check if the device is still usable */ | |
532 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
533 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
534 | * returns an immediate error upwards, and signals | |
535 | * that the device is no longer present */ | |
536 | cmd->result = DID_NO_CONNECT << 16; | |
537 | atomic_inc(&cmd->device->iorequest_cnt); | |
69b52893 | 538 | __scsi_done(cmd); |
1da177e4 LT |
539 | /* return 0 (because the command has been processed) */ |
540 | goto out; | |
541 | } | |
542 | ||
543 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
544 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
545 | /* | |
546 | * in SDEV_BLOCK, the command is just put back on the device | |
547 | * queue. The suspend state has already blocked the queue so | |
548 | * future requests should not occur until the device | |
549 | * transitions out of the suspend state. | |
550 | */ | |
551 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
552 | ||
553 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
554 | ||
555 | /* | |
556 | * NOTE: rtn is still zero here because we don't need the | |
557 | * queue to be plugged on return (it's already stopped) | |
558 | */ | |
559 | goto out; | |
560 | } | |
561 | ||
562 | /* | |
563 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
564 | */ | |
4d7db04a JB |
565 | if (cmd->device->scsi_level <= SCSI_2 && |
566 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
567 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
568 | (cmd->device->lun << 5 & 0xe0); | |
569 | } | |
570 | ||
571 | /* | |
572 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
573 | * we can avoid the drive not being ready. | |
574 | */ | |
575 | timeout = host->last_reset + MIN_RESET_DELAY; | |
576 | ||
577 | if (host->resetting && time_before(jiffies, timeout)) { | |
578 | int ticks_remaining = timeout - jiffies; | |
579 | /* | |
580 | * NOTE: This may be executed from within an interrupt | |
581 | * handler! This is bad, but for now, it'll do. The irq | |
582 | * level of the interrupt handler has been masked out by the | |
583 | * platform dependent interrupt handling code already, so the | |
584 | * sti() here will not cause another call to the SCSI host's | |
585 | * interrupt handler (assuming there is one irq-level per | |
586 | * host). | |
587 | */ | |
588 | while (--ticks_remaining >= 0) | |
589 | mdelay(1 + 999 / HZ); | |
590 | host->resetting = 0; | |
591 | } | |
592 | ||
593 | /* | |
594 | * AK: unlikely race here: for some reason the timer could | |
595 | * expire before the serial number is set up below. | |
596 | */ | |
597 | scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out); | |
598 | ||
599 | scsi_log_send(cmd); | |
600 | ||
601 | /* | |
602 | * We will use a queued command if possible, otherwise we will | |
603 | * emulate the queuing and calling of completion function ourselves. | |
604 | */ | |
1da177e4 LT |
605 | atomic_inc(&cmd->device->iorequest_cnt); |
606 | ||
607 | /* | |
608 | * Before we queue this command, check if the command | |
609 | * length exceeds what the host adapter can handle. | |
610 | */ | |
611 | if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) { | |
612 | SCSI_LOG_MLQUEUE(3, | |
613 | printk("queuecommand : command too long.\n")); | |
614 | cmd->result = (DID_ABORT << 16); | |
615 | ||
616 | scsi_done(cmd); | |
617 | goto out; | |
618 | } | |
619 | ||
620 | spin_lock_irqsave(host->host_lock, flags); | |
621 | scsi_cmd_get_serial(host, cmd); | |
622 | ||
d2c9d9ea | 623 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
624 | cmd->result = (DID_NO_CONNECT << 16); |
625 | scsi_done(cmd); | |
626 | } else { | |
627 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
628 | } | |
629 | spin_unlock_irqrestore(host->host_lock, flags); | |
630 | if (rtn) { | |
d8c37e7b TH |
631 | if (scsi_delete_timer(cmd)) { |
632 | atomic_inc(&cmd->device->iodone_cnt); | |
633 | scsi_queue_insert(cmd, | |
634 | (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? | |
635 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
636 | } | |
1da177e4 LT |
637 | SCSI_LOG_MLQUEUE(3, |
638 | printk("queuecommand : request rejected\n")); | |
639 | } | |
640 | ||
641 | out: | |
642 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
643 | return rtn; | |
644 | } | |
645 | ||
89f48c4d LT |
646 | /** |
647 | * scsi_req_abort_cmd -- Request command recovery for the specified command | |
eb44820c | 648 | * @cmd: pointer to the SCSI command of interest |
89f48c4d LT |
649 | * |
650 | * This function requests that SCSI Core start recovery for the | |
651 | * command by deleting the timer and adding the command to the eh | |
652 | * queue. It can be called by either LLDDs or SCSI Core. LLDDs who | |
653 | * implement their own error recovery MAY ignore the timeout event if | |
654 | * they generated scsi_req_abort_cmd. | |
655 | */ | |
656 | void scsi_req_abort_cmd(struct scsi_cmnd *cmd) | |
657 | { | |
658 | if (!scsi_delete_timer(cmd)) | |
659 | return; | |
660 | scsi_times_out(cmd); | |
661 | } | |
662 | EXPORT_SYMBOL(scsi_req_abort_cmd); | |
663 | ||
1da177e4 LT |
664 | /** |
665 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
666 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
667 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
668 | * | |
eb44820c RL |
669 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
670 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
671 | * enqueues the command to the done queue for further processing. | |
1da177e4 LT |
672 | * |
673 | * This is the producer of the done queue who enqueues at the tail. | |
674 | * | |
675 | * This function is interrupt context safe. | |
676 | */ | |
52c1da39 | 677 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 LT |
678 | { |
679 | /* | |
eb44820c | 680 | * We don't have to worry about this one timing out anymore. |
1da177e4 LT |
681 | * If we are unable to remove the timer, then the command |
682 | * has already timed out. In which case, we have no choice but to | |
683 | * let the timeout function run, as we have no idea where in fact | |
684 | * that function could really be. It might be on another processor, | |
685 | * etc, etc. | |
686 | */ | |
687 | if (!scsi_delete_timer(cmd)) | |
688 | return; | |
689 | __scsi_done(cmd); | |
690 | } | |
691 | ||
692 | /* Private entry to scsi_done() to complete a command when the timer | |
693 | * isn't running --- used by scsi_times_out */ | |
694 | void __scsi_done(struct scsi_cmnd *cmd) | |
695 | { | |
1aea6434 | 696 | struct request *rq = cmd->request; |
1da177e4 LT |
697 | |
698 | /* | |
699 | * Set the serial numbers back to zero | |
700 | */ | |
701 | cmd->serial_number = 0; | |
1da177e4 LT |
702 | |
703 | atomic_inc(&cmd->device->iodone_cnt); | |
704 | if (cmd->result) | |
705 | atomic_inc(&cmd->device->ioerr_cnt); | |
706 | ||
1aea6434 JA |
707 | BUG_ON(!rq); |
708 | ||
1da177e4 | 709 | /* |
1aea6434 JA |
710 | * The uptodate/nbytes values don't matter, as we allow partial |
711 | * completes and thus will check this in the softirq callback | |
1da177e4 | 712 | */ |
1aea6434 JA |
713 | rq->completion_data = cmd; |
714 | blk_complete_request(rq); | |
1da177e4 LT |
715 | } |
716 | ||
7b3d9545 LT |
717 | /* Move this to a header if it becomes more generally useful */ |
718 | static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) | |
719 | { | |
720 | return *(struct scsi_driver **)cmd->request->rq_disk->private_data; | |
721 | } | |
722 | ||
eb44820c RL |
723 | /** |
724 | * scsi_finish_command - cleanup and pass command back to upper layer | |
725 | * @cmd: the command | |
1da177e4 | 726 | * |
eb44820c | 727 | * Description: Pass command off to upper layer for finishing of I/O |
1da177e4 LT |
728 | * request, waking processes that are waiting on results, |
729 | * etc. | |
730 | */ | |
731 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
732 | { | |
733 | struct scsi_device *sdev = cmd->device; | |
734 | struct Scsi_Host *shost = sdev->host; | |
7b3d9545 LT |
735 | struct scsi_driver *drv; |
736 | unsigned int good_bytes; | |
1da177e4 LT |
737 | |
738 | scsi_device_unbusy(sdev); | |
739 | ||
740 | /* | |
741 | * Clear the flags which say that the device/host is no longer | |
742 | * capable of accepting new commands. These are set in scsi_queue.c | |
743 | * for both the queue full condition on a device, and for a | |
744 | * host full condition on the host. | |
745 | * | |
746 | * XXX(hch): What about locking? | |
747 | */ | |
748 | shost->host_blocked = 0; | |
749 | sdev->device_blocked = 0; | |
750 | ||
751 | /* | |
752 | * If we have valid sense information, then some kind of recovery | |
753 | * must have taken place. Make a note of this. | |
754 | */ | |
755 | if (SCSI_SENSE_VALID(cmd)) | |
756 | cmd->result |= (DRIVER_SENSE << 24); | |
757 | ||
3bf743e7 JG |
758 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
759 | "Notifying upper driver of completion " | |
760 | "(result %x)\n", cmd->result)); | |
1da177e4 | 761 | |
e97a294e | 762 | good_bytes = scsi_bufflen(cmd) + cmd->request->extra_len; |
7b3d9545 LT |
763 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { |
764 | drv = scsi_cmd_to_driver(cmd); | |
765 | if (drv->done) | |
766 | good_bytes = drv->done(cmd); | |
767 | } | |
768 | scsi_io_completion(cmd, good_bytes); | |
1da177e4 LT |
769 | } |
770 | EXPORT_SYMBOL(scsi_finish_command); | |
771 | ||
eb44820c RL |
772 | /** |
773 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth | |
774 | * @sdev: SCSI Device in question | |
775 | * @tagged: Do we use tagged queueing (non-0) or do we treat | |
776 | * this device as an untagged device (0) | |
777 | * @tags: Number of tags allowed if tagged queueing enabled, | |
778 | * or number of commands the low level driver can | |
779 | * queue up in non-tagged mode (as per cmd_per_lun). | |
1da177e4 LT |
780 | * |
781 | * Returns: Nothing | |
782 | * | |
783 | * Lock Status: None held on entry | |
784 | * | |
785 | * Notes: Low level drivers may call this at any time and we will do | |
786 | * the right thing depending on whether or not the device is | |
787 | * currently active and whether or not it even has the | |
788 | * command blocks built yet. | |
789 | */ | |
790 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
791 | { | |
792 | unsigned long flags; | |
793 | ||
794 | /* | |
795 | * refuse to set tagged depth to an unworkable size | |
796 | */ | |
797 | if (tags <= 0) | |
798 | return; | |
799 | ||
800 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
801 | ||
eb44820c RL |
802 | /* Check to see if the queue is managed by the block layer. |
803 | * If it is, and we fail to adjust the depth, exit. */ | |
1da177e4 LT |
804 | if (blk_queue_tagged(sdev->request_queue) && |
805 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
806 | goto out; | |
807 | ||
808 | sdev->queue_depth = tags; | |
809 | switch (tagged) { | |
810 | case MSG_ORDERED_TAG: | |
811 | sdev->ordered_tags = 1; | |
812 | sdev->simple_tags = 1; | |
813 | break; | |
814 | case MSG_SIMPLE_TAG: | |
815 | sdev->ordered_tags = 0; | |
816 | sdev->simple_tags = 1; | |
817 | break; | |
818 | default: | |
9ccfc756 JB |
819 | sdev_printk(KERN_WARNING, sdev, |
820 | "scsi_adjust_queue_depth, bad queue type, " | |
821 | "disabled\n"); | |
1da177e4 LT |
822 | case 0: |
823 | sdev->ordered_tags = sdev->simple_tags = 0; | |
824 | sdev->queue_depth = tags; | |
825 | break; | |
826 | } | |
827 | out: | |
828 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
829 | } | |
830 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
831 | ||
eb44820c RL |
832 | /** |
833 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth | |
834 | * @sdev: SCSI Device in question | |
835 | * @depth: Current number of outstanding SCSI commands on this device, | |
836 | * not counting the one returned as QUEUE_FULL. | |
1da177e4 | 837 | * |
eb44820c | 838 | * Description: This function will track successive QUEUE_FULL events on a |
1da177e4 LT |
839 | * specific SCSI device to determine if and when there is a |
840 | * need to adjust the queue depth on the device. | |
841 | * | |
eb44820c | 842 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
1da177e4 LT |
843 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
844 | * as the untagged command depth | |
845 | * | |
846 | * Lock Status: None held on entry | |
847 | * | |
848 | * Notes: Low level drivers may call this at any time and we will do | |
849 | * "The Right Thing." We are interrupt context safe. | |
850 | */ | |
851 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
852 | { | |
853 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
854 | return 0; | |
855 | ||
856 | sdev->last_queue_full_time = (jiffies >> 4); | |
857 | if (sdev->last_queue_full_depth != depth) { | |
858 | sdev->last_queue_full_count = 1; | |
859 | sdev->last_queue_full_depth = depth; | |
860 | } else { | |
861 | sdev->last_queue_full_count++; | |
862 | } | |
863 | ||
864 | if (sdev->last_queue_full_count <= 10) | |
865 | return 0; | |
866 | if (sdev->last_queue_full_depth < 8) { | |
867 | /* Drop back to untagged */ | |
868 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
869 | return -1; | |
870 | } | |
871 | ||
872 | if (sdev->ordered_tags) | |
873 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
874 | else | |
875 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
876 | return depth; | |
877 | } | |
878 | EXPORT_SYMBOL(scsi_track_queue_full); | |
879 | ||
880 | /** | |
eb44820c | 881 | * scsi_device_get - get an additional reference to a scsi_device |
1da177e4 LT |
882 | * @sdev: device to get a reference to |
883 | * | |
eb44820c | 884 | * Description: Gets a reference to the scsi_device and increments the use count |
1da177e4 LT |
885 | * of the underlying LLDD module. You must hold host_lock of the |
886 | * parent Scsi_Host or already have a reference when calling this. | |
887 | */ | |
888 | int scsi_device_get(struct scsi_device *sdev) | |
889 | { | |
85b6c720 | 890 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
891 | return -ENXIO; |
892 | if (!get_device(&sdev->sdev_gendev)) | |
893 | return -ENXIO; | |
85b6c720 JB |
894 | /* We can fail this if we're doing SCSI operations |
895 | * from module exit (like cache flush) */ | |
896 | try_module_get(sdev->host->hostt->module); | |
897 | ||
1da177e4 LT |
898 | return 0; |
899 | } | |
900 | EXPORT_SYMBOL(scsi_device_get); | |
901 | ||
902 | /** | |
903 | * scsi_device_put - release a reference to a scsi_device | |
904 | * @sdev: device to release a reference on. | |
905 | * | |
eb44820c RL |
906 | * Description: Release a reference to the scsi_device and decrements the use |
907 | * count of the underlying LLDD module. The device is freed once the last | |
1da177e4 LT |
908 | * user vanishes. |
909 | */ | |
910 | void scsi_device_put(struct scsi_device *sdev) | |
911 | { | |
504fb37a | 912 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
913 | struct module *module = sdev->host->hostt->module; |
914 | ||
85b6c720 JB |
915 | /* The module refcount will be zero if scsi_device_get() |
916 | * was called from a module removal routine */ | |
f479ab87 JB |
917 | if (module && module_refcount(module) != 0) |
918 | module_put(module); | |
a506b44b | 919 | #endif |
1da177e4 LT |
920 | put_device(&sdev->sdev_gendev); |
921 | } | |
922 | EXPORT_SYMBOL(scsi_device_put); | |
923 | ||
eb44820c | 924 | /* helper for shost_for_each_device, see that for documentation */ |
1da177e4 LT |
925 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
926 | struct scsi_device *prev) | |
927 | { | |
928 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
929 | struct scsi_device *next = NULL; | |
930 | unsigned long flags; | |
931 | ||
932 | spin_lock_irqsave(shost->host_lock, flags); | |
933 | while (list->next != &shost->__devices) { | |
934 | next = list_entry(list->next, struct scsi_device, siblings); | |
935 | /* skip devices that we can't get a reference to */ | |
936 | if (!scsi_device_get(next)) | |
937 | break; | |
938 | next = NULL; | |
939 | list = list->next; | |
940 | } | |
941 | spin_unlock_irqrestore(shost->host_lock, flags); | |
942 | ||
943 | if (prev) | |
944 | scsi_device_put(prev); | |
945 | return next; | |
946 | } | |
947 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
948 | ||
949 | /** | |
950 | * starget_for_each_device - helper to walk all devices of a target | |
951 | * @starget: target whose devices we want to iterate over. | |
eb44820c RL |
952 | * @data: Opaque passed to each function call. |
953 | * @fn: Function to call on each device | |
1da177e4 | 954 | * |
522939d4 | 955 | * This traverses over each device of @starget. The devices have |
1da177e4 LT |
956 | * a reference that must be released by scsi_host_put when breaking |
957 | * out of the loop. | |
958 | */ | |
522939d4 | 959 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1da177e4 LT |
960 | void (*fn)(struct scsi_device *, void *)) |
961 | { | |
962 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
963 | struct scsi_device *sdev; | |
964 | ||
965 | shost_for_each_device(sdev, shost) { | |
966 | if ((sdev->channel == starget->channel) && | |
967 | (sdev->id == starget->id)) | |
968 | fn(sdev, data); | |
969 | } | |
970 | } | |
971 | EXPORT_SYMBOL(starget_for_each_device); | |
972 | ||
522939d4 | 973 | /** |
14f501a4 | 974 | * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
522939d4 | 975 | * @starget: target whose devices we want to iterate over. |
14f501a4 RD |
976 | * @data: parameter for callback @fn() |
977 | * @fn: callback function that is invoked for each device | |
522939d4 MR |
978 | * |
979 | * This traverses over each device of @starget. It does _not_ | |
980 | * take a reference on the scsi_device, so the whole loop must be | |
981 | * protected by shost->host_lock. | |
982 | * | |
983 | * Note: The only reason why drivers would want to use this is because | |
984 | * they need to access the device list in irq context. Otherwise you | |
985 | * really want to use starget_for_each_device instead. | |
986 | **/ | |
987 | void __starget_for_each_device(struct scsi_target *starget, void *data, | |
988 | void (*fn)(struct scsi_device *, void *)) | |
989 | { | |
990 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
991 | struct scsi_device *sdev; | |
992 | ||
993 | __shost_for_each_device(sdev, shost) { | |
994 | if ((sdev->channel == starget->channel) && | |
995 | (sdev->id == starget->id)) | |
996 | fn(sdev, data); | |
997 | } | |
998 | } | |
999 | EXPORT_SYMBOL(__starget_for_each_device); | |
1000 | ||
1da177e4 LT |
1001 | /** |
1002 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
1003 | * @starget: SCSI target pointer | |
1004 | * @lun: SCSI Logical Unit Number | |
1005 | * | |
eb44820c RL |
1006 | * Description: Looks up the scsi_device with the specified @lun for a given |
1007 | * @starget. The returned scsi_device does not have an additional | |
1da177e4 LT |
1008 | * reference. You must hold the host's host_lock over this call and |
1009 | * any access to the returned scsi_device. | |
1010 | * | |
dc8875e1 | 1011 | * Note: The only reason why drivers should use this is because |
eb44820c | 1012 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1013 | * really want to use scsi_device_lookup_by_target instead. |
1014 | **/ | |
1015 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
1016 | uint lun) | |
1017 | { | |
1018 | struct scsi_device *sdev; | |
1019 | ||
1020 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
1021 | if (sdev->lun ==lun) | |
1022 | return sdev; | |
1023 | } | |
1024 | ||
1025 | return NULL; | |
1026 | } | |
1027 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
1028 | ||
1029 | /** | |
1030 | * scsi_device_lookup_by_target - find a device given the target | |
1031 | * @starget: SCSI target pointer | |
1032 | * @lun: SCSI Logical Unit Number | |
1033 | * | |
eb44820c RL |
1034 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1035 | * for a given host. The returned scsi_device has an additional reference that | |
1036 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1037 | **/ |
1038 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
1039 | uint lun) | |
1040 | { | |
1041 | struct scsi_device *sdev; | |
1042 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1043 | unsigned long flags; | |
1044 | ||
1045 | spin_lock_irqsave(shost->host_lock, flags); | |
1046 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
1047 | if (sdev && scsi_device_get(sdev)) | |
1048 | sdev = NULL; | |
1049 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1050 | ||
1051 | return sdev; | |
1052 | } | |
1053 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1054 | ||
1055 | /** | |
eb44820c | 1056 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1da177e4 LT |
1057 | * @shost: SCSI host pointer |
1058 | * @channel: SCSI channel (zero if only one channel) | |
eb44820c | 1059 | * @id: SCSI target number (physical unit number) |
1da177e4 LT |
1060 | * @lun: SCSI Logical Unit Number |
1061 | * | |
eb44820c RL |
1062 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1063 | * for a given host. The returned scsi_device does not have an additional | |
1064 | * reference. You must hold the host's host_lock over this call and any access | |
1065 | * to the returned scsi_device. | |
1da177e4 LT |
1066 | * |
1067 | * Note: The only reason why drivers would want to use this is because | |
eb44820c | 1068 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1069 | * really want to use scsi_device_lookup instead. |
1070 | **/ | |
1071 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1072 | uint channel, uint id, uint lun) | |
1073 | { | |
1074 | struct scsi_device *sdev; | |
1075 | ||
1076 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1077 | if (sdev->channel == channel && sdev->id == id && | |
1078 | sdev->lun ==lun) | |
1079 | return sdev; | |
1080 | } | |
1081 | ||
1082 | return NULL; | |
1083 | } | |
1084 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1085 | ||
1086 | /** | |
1087 | * scsi_device_lookup - find a device given the host | |
1088 | * @shost: SCSI host pointer | |
1089 | * @channel: SCSI channel (zero if only one channel) | |
1090 | * @id: SCSI target number (physical unit number) | |
1091 | * @lun: SCSI Logical Unit Number | |
1092 | * | |
eb44820c RL |
1093 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1094 | * for a given host. The returned scsi_device has an additional reference that | |
1095 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1096 | **/ |
1097 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1098 | uint channel, uint id, uint lun) | |
1099 | { | |
1100 | struct scsi_device *sdev; | |
1101 | unsigned long flags; | |
1102 | ||
1103 | spin_lock_irqsave(shost->host_lock, flags); | |
1104 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1105 | if (sdev && scsi_device_get(sdev)) | |
1106 | sdev = NULL; | |
1107 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1108 | ||
1109 | return sdev; | |
1110 | } | |
1111 | EXPORT_SYMBOL(scsi_device_lookup); | |
1112 | ||
1da177e4 LT |
1113 | MODULE_DESCRIPTION("SCSI core"); |
1114 | MODULE_LICENSE("GPL"); | |
1115 | ||
1116 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1117 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1118 | ||
1119 | static int __init init_scsi(void) | |
1120 | { | |
9bf09c23 | 1121 | int error; |
1da177e4 LT |
1122 | |
1123 | error = scsi_init_queue(); | |
1124 | if (error) | |
1125 | return error; | |
1126 | error = scsi_init_procfs(); | |
1127 | if (error) | |
1128 | goto cleanup_queue; | |
1129 | error = scsi_init_devinfo(); | |
1130 | if (error) | |
1131 | goto cleanup_procfs; | |
1132 | error = scsi_init_hosts(); | |
1133 | if (error) | |
1134 | goto cleanup_devlist; | |
1135 | error = scsi_init_sysctl(); | |
1136 | if (error) | |
1137 | goto cleanup_hosts; | |
1138 | error = scsi_sysfs_register(); | |
1139 | if (error) | |
1140 | goto cleanup_sysctl; | |
1141 | ||
84314fd4 JS |
1142 | scsi_netlink_init(); |
1143 | ||
1da177e4 LT |
1144 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1145 | return 0; | |
1146 | ||
1147 | cleanup_sysctl: | |
1148 | scsi_exit_sysctl(); | |
1149 | cleanup_hosts: | |
1150 | scsi_exit_hosts(); | |
1151 | cleanup_devlist: | |
1152 | scsi_exit_devinfo(); | |
1153 | cleanup_procfs: | |
1154 | scsi_exit_procfs(); | |
1155 | cleanup_queue: | |
1156 | scsi_exit_queue(); | |
1157 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1158 | -error); | |
1159 | return error; | |
1160 | } | |
1161 | ||
1162 | static void __exit exit_scsi(void) | |
1163 | { | |
84314fd4 | 1164 | scsi_netlink_exit(); |
1da177e4 LT |
1165 | scsi_sysfs_unregister(); |
1166 | scsi_exit_sysctl(); | |
1167 | scsi_exit_hosts(); | |
1168 | scsi_exit_devinfo(); | |
1da177e4 LT |
1169 | scsi_exit_procfs(); |
1170 | scsi_exit_queue(); | |
1da177e4 LT |
1171 | } |
1172 | ||
1173 | subsys_initcall(init_scsi); | |
1174 | module_exit(exit_scsi); |