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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> |
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> |
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> |
56 | #include <linux/mutex.h> |
57 | #include <linux/async.h> |
58 | #include <asm/unaligned.h> |
59 | |
60 | #include <scsi/scsi.h> |
61 | #include <scsi/scsi_cmnd.h> |
62 | #include <scsi/scsi_dbg.h> |
63 | #include <scsi/scsi_device.h> |
64 | #include <scsi/scsi_driver.h> |
65 | #include <scsi/scsi_eh.h> |
66 | #include <scsi/scsi_host.h> |
67 | #include <scsi/scsi_tcq.h> |
68 | |
69 | #include "scsi_priv.h" |
70 | #include "scsi_logging.h" |
71 | |
72 | #define CREATE_TRACE_POINTS |
73 | #include <trace/events/scsi.h> |
74 | |
75 | static void scsi_done(struct scsi_cmnd *cmd); |
76 | |
77 | /* |
78 | * Definitions and constants. |
79 | */ |
80 | |
81 | #define MIN_RESET_DELAY (2*HZ) |
82 | |
83 | /* Do not call reset on error if we just did a reset within 15 sec. */ |
84 | #define MIN_RESET_PERIOD (15*HZ) |
85 | |
86 | /* |
87 | * Note - the initial logging level can be set here to log events at boot time. |
88 | * After the system is up, you may enable logging via the /proc interface. |
89 | */ |
90 | unsigned int scsi_logging_level; |
91 | #if defined(CONFIG_SCSI_LOGGING) |
92 | EXPORT_SYMBOL(scsi_logging_level); |
93 | #endif |
94 | |
95 | /* sd, scsi core and power management need to coordinate flushing async actions */ |
96 | ASYNC_DOMAIN(scsi_sd_probe_domain); |
97 | EXPORT_SYMBOL(scsi_sd_probe_domain); |
98 | |
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 | */ |
103 | static const char *const scsi_device_types[] = { |
104 | "Direct-Access ", |
105 | "Sequential-Access", |
106 | "Printer ", |
107 | "Processor ", |
108 | "WORM ", |
109 | "CD-ROM ", |
110 | "Scanner ", |
111 | "Optical Device ", |
112 | "Medium Changer ", |
113 | "Communications ", |
114 | "ASC IT8 ", |
115 | "ASC IT8 ", |
116 | "RAID ", |
117 | "Enclosure ", |
118 | "Direct-Access-RBC", |
119 | "Optical card ", |
120 | "Bridge controller", |
121 | "Object storage ", |
122 | "Automation/Drive ", |
123 | }; |
124 | |
125 | /** |
126 | * scsi_device_type - Return 17 char string indicating device type. |
127 | * @type: type number to look up |
128 | */ |
129 | |
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 "; |
136 | if (type >= ARRAY_SIZE(scsi_device_types)) |
137 | return "Unknown "; |
138 | return scsi_device_types[type]; |
139 | } |
140 | |
141 | EXPORT_SYMBOL(scsi_device_type); |
142 | |
143 | struct scsi_host_cmd_pool { |
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; |
151 | }; |
152 | |
153 | static struct scsi_host_cmd_pool scsi_cmd_pool = { |
154 | .cmd_name = "scsi_cmd_cache", |
155 | .sense_name = "scsi_sense_cache", |
156 | .slab_flags = SLAB_HWCACHE_ALIGN, |
157 | }; |
158 | |
159 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { |
160 | .cmd_name = "scsi_cmd_cache(DMA)", |
161 | .sense_name = "scsi_sense_cache(DMA)", |
162 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, |
163 | .gfp_mask = __GFP_DMA, |
164 | }; |
165 | |
166 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
167 | |
168 | /** |
169 | * scsi_pool_alloc_command - internal function to get a fully allocated command |
170 | * @pool: slab pool to allocate the command from |
171 | * @gfp_mask: mask for the allocation |
172 | * |
173 | * Returns a fully allocated command (with the allied sense buffer) or |
174 | * NULL on failure |
175 | */ |
176 | static struct scsi_cmnd * |
177 | scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask) |
178 | { |
179 | struct scsi_cmnd *cmd; |
180 | |
181 | cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); |
182 | if (!cmd) |
183 | return NULL; |
184 | |
185 | cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, |
186 | gfp_mask | pool->gfp_mask); |
187 | if (!cmd->sense_buffer) { |
188 | kmem_cache_free(pool->cmd_slab, cmd); |
189 | return NULL; |
190 | } |
191 | |
192 | return cmd; |
193 | } |
194 | |
195 | /** |
196 | * scsi_pool_free_command - internal function to release a command |
197 | * @pool: slab pool to allocate the command from |
198 | * @cmd: command to release |
199 | * |
200 | * the command must previously have been allocated by |
201 | * scsi_pool_alloc_command. |
202 | */ |
203 | static void |
204 | scsi_pool_free_command(struct scsi_host_cmd_pool *pool, |
205 | struct scsi_cmnd *cmd) |
206 | { |
207 | if (cmd->prot_sdb) |
208 | kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); |
209 | |
210 | kmem_cache_free(pool->sense_slab, cmd->sense_buffer); |
211 | kmem_cache_free(pool->cmd_slab, cmd); |
212 | } |
213 | |
214 | /** |
215 | * scsi_host_alloc_command - internal function to allocate command |
216 | * @shost: SCSI host whose pool to allocate from |
217 | * @gfp_mask: mask for the allocation |
218 | * |
219 | * Returns a fully allocated command with sense buffer and protection |
220 | * data buffer (where applicable) or NULL on failure |
221 | */ |
222 | static struct scsi_cmnd * |
223 | scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
224 | { |
225 | struct scsi_cmnd *cmd; |
226 | |
227 | cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask); |
228 | if (!cmd) |
229 | return NULL; |
230 | |
231 | if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { |
232 | cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); |
233 | |
234 | if (!cmd->prot_sdb) { |
235 | scsi_pool_free_command(shost->cmd_pool, cmd); |
236 | return NULL; |
237 | } |
238 | } |
239 | |
240 | return cmd; |
241 | } |
242 | |
243 | /** |
244 | * __scsi_get_command - Allocate a struct scsi_cmnd |
245 | * @shost: host to transmit command |
246 | * @gfp_mask: allocation mask |
247 | * |
248 | * Description: allocate a struct scsi_cmd from host's slab, recycling from the |
249 | * host's free_list if necessary. |
250 | */ |
251 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
252 | { |
253 | struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask); |
254 | |
255 | if (unlikely(!cmd)) { |
256 | unsigned long flags; |
257 | |
258 | spin_lock_irqsave(&shost->free_list_lock, flags); |
259 | if (likely(!list_empty(&shost->free_list))) { |
260 | cmd = list_entry(shost->free_list.next, |
261 | struct scsi_cmnd, list); |
262 | list_del_init(&cmd->list); |
263 | } |
264 | spin_unlock_irqrestore(&shost->free_list_lock, flags); |
265 | |
266 | if (cmd) { |
267 | void *buf, *prot; |
268 | |
269 | buf = cmd->sense_buffer; |
270 | prot = cmd->prot_sdb; |
271 | |
272 | memset(cmd, 0, sizeof(*cmd)); |
273 | |
274 | cmd->sense_buffer = buf; |
275 | cmd->prot_sdb = prot; |
276 | } |
277 | } |
278 | |
279 | return cmd; |
280 | } |
281 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
282 | |
283 | /** |
284 | * scsi_get_command - Allocate and setup a scsi command block |
285 | * @dev: parent scsi device |
286 | * @gfp_mask: allocator flags |
287 | * |
288 | * Returns: The allocated scsi command structure. |
289 | */ |
290 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
291 | { |
292 | struct scsi_cmnd *cmd; |
293 | |
294 | /* Bail if we can't get a reference to the device */ |
295 | if (!get_device(&dev->sdev_gendev)) |
296 | return NULL; |
297 | |
298 | cmd = __scsi_get_command(dev->host, gfp_mask); |
299 | |
300 | if (likely(cmd != NULL)) { |
301 | unsigned long flags; |
302 | |
303 | cmd->device = dev; |
304 | INIT_LIST_HEAD(&cmd->list); |
305 | spin_lock_irqsave(&dev->list_lock, flags); |
306 | list_add_tail(&cmd->list, &dev->cmd_list); |
307 | spin_unlock_irqrestore(&dev->list_lock, flags); |
308 | cmd->jiffies_at_alloc = jiffies; |
309 | } else |
310 | put_device(&dev->sdev_gendev); |
311 | |
312 | return cmd; |
313 | } |
314 | EXPORT_SYMBOL(scsi_get_command); |
315 | |
316 | /** |
317 | * __scsi_put_command - Free a struct scsi_cmnd |
318 | * @shost: dev->host |
319 | * @cmd: Command to free |
320 | * @dev: parent scsi device |
321 | */ |
322 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
323 | struct device *dev) |
324 | { |
325 | unsigned long flags; |
326 | |
327 | /* changing locks here, don't need to restore the irq state */ |
328 | spin_lock_irqsave(&shost->free_list_lock, flags); |
329 | if (unlikely(list_empty(&shost->free_list))) { |
330 | list_add(&cmd->list, &shost->free_list); |
331 | cmd = NULL; |
332 | } |
333 | spin_unlock_irqrestore(&shost->free_list_lock, flags); |
334 | |
335 | if (likely(cmd != NULL)) |
336 | scsi_pool_free_command(shost->cmd_pool, cmd); |
337 | |
338 | put_device(dev); |
339 | } |
340 | EXPORT_SYMBOL(__scsi_put_command); |
341 | |
342 | /** |
343 | * scsi_put_command - Free a scsi command block |
344 | * @cmd: command block to free |
345 | * |
346 | * Returns: Nothing. |
347 | * |
348 | * Notes: The command must not belong to any lists. |
349 | */ |
350 | void scsi_put_command(struct scsi_cmnd *cmd) |
351 | { |
352 | struct scsi_device *sdev = cmd->device; |
353 | unsigned long flags; |
354 | |
355 | /* serious error if the command hasn't come from a device list */ |
356 | spin_lock_irqsave(&cmd->device->list_lock, flags); |
357 | BUG_ON(list_empty(&cmd->list)); |
358 | list_del_init(&cmd->list); |
359 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
360 | |
361 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
362 | } |
363 | EXPORT_SYMBOL(scsi_put_command); |
364 | |
365 | static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask) |
366 | { |
367 | struct scsi_host_cmd_pool *retval = NULL, *pool; |
368 | /* |
369 | * Select a command slab for this host and create it if not |
370 | * yet existent. |
371 | */ |
372 | mutex_lock(&host_cmd_pool_mutex); |
373 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
374 | &scsi_cmd_pool; |
375 | if (!pool->users) { |
376 | pool->cmd_slab = kmem_cache_create(pool->cmd_name, |
377 | sizeof(struct scsi_cmnd), 0, |
378 | pool->slab_flags, NULL); |
379 | if (!pool->cmd_slab) |
380 | goto fail; |
381 | |
382 | pool->sense_slab = kmem_cache_create(pool->sense_name, |
383 | SCSI_SENSE_BUFFERSIZE, 0, |
384 | pool->slab_flags, NULL); |
385 | if (!pool->sense_slab) { |
386 | kmem_cache_destroy(pool->cmd_slab); |
387 | goto fail; |
388 | } |
389 | } |
390 | |
391 | pool->users++; |
392 | retval = pool; |
393 | fail: |
394 | mutex_unlock(&host_cmd_pool_mutex); |
395 | return retval; |
396 | } |
397 | |
398 | static void scsi_put_host_cmd_pool(gfp_t gfp_mask) |
399 | { |
400 | struct scsi_host_cmd_pool *pool; |
401 | |
402 | mutex_lock(&host_cmd_pool_mutex); |
403 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
404 | &scsi_cmd_pool; |
405 | /* |
406 | * This may happen if a driver has a mismatched get and put |
407 | * of the command pool; the driver should be implicated in |
408 | * the stack trace |
409 | */ |
410 | BUG_ON(pool->users == 0); |
411 | |
412 | if (!--pool->users) { |
413 | kmem_cache_destroy(pool->cmd_slab); |
414 | kmem_cache_destroy(pool->sense_slab); |
415 | } |
416 | mutex_unlock(&host_cmd_pool_mutex); |
417 | } |
418 | |
419 | /** |
420 | * scsi_allocate_command - get a fully allocated SCSI command |
421 | * @gfp_mask: allocation mask |
422 | * |
423 | * This function is for use outside of the normal host based pools. |
424 | * It allocates the relevant command and takes an additional reference |
425 | * on the pool it used. This function *must* be paired with |
426 | * scsi_free_command which also has the identical mask, otherwise the |
427 | * free pool counts will eventually go wrong and you'll trigger a bug. |
428 | * |
429 | * This function should *only* be used by drivers that need a static |
430 | * command allocation at start of day for internal functions. |
431 | */ |
432 | struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask) |
433 | { |
434 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); |
435 | |
436 | if (!pool) |
437 | return NULL; |
438 | |
439 | return scsi_pool_alloc_command(pool, gfp_mask); |
440 | } |
441 | EXPORT_SYMBOL(scsi_allocate_command); |
442 | |
443 | /** |
444 | * scsi_free_command - free a command allocated by scsi_allocate_command |
445 | * @gfp_mask: mask used in the original allocation |
446 | * @cmd: command to free |
447 | * |
448 | * Note: using the original allocation mask is vital because that's |
449 | * what determines which command pool we use to free the command. Any |
450 | * mismatch will cause the system to BUG eventually. |
451 | */ |
452 | void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd) |
453 | { |
454 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); |
455 | |
456 | /* |
457 | * this could trigger if the mask to scsi_allocate_command |
458 | * doesn't match this mask. Otherwise we're guaranteed that this |
459 | * succeeds because scsi_allocate_command must have taken a reference |
460 | * on the pool |
461 | */ |
462 | BUG_ON(!pool); |
463 | |
464 | scsi_pool_free_command(pool, cmd); |
465 | /* |
466 | * scsi_put_host_cmd_pool is called twice; once to release the |
467 | * reference we took above, and once to release the reference |
468 | * originally taken by scsi_allocate_command |
469 | */ |
470 | scsi_put_host_cmd_pool(gfp_mask); |
471 | scsi_put_host_cmd_pool(gfp_mask); |
472 | } |
473 | EXPORT_SYMBOL(scsi_free_command); |
474 | |
475 | /** |
476 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. |
477 | * @shost: host to allocate the freelist for. |
478 | * |
479 | * Description: The command freelist protects against system-wide out of memory |
480 | * deadlock by preallocating one SCSI command structure for each host, so the |
481 | * system can always write to a swap file on a device associated with that host. |
482 | * |
483 | * Returns: Nothing. |
484 | */ |
485 | int scsi_setup_command_freelist(struct Scsi_Host *shost) |
486 | { |
487 | struct scsi_cmnd *cmd; |
488 | const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; |
489 | |
490 | spin_lock_init(&shost->free_list_lock); |
491 | INIT_LIST_HEAD(&shost->free_list); |
492 | |
493 | shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask); |
494 | |
495 | if (!shost->cmd_pool) |
496 | return -ENOMEM; |
497 | |
498 | /* |
499 | * Get one backup command for this host. |
500 | */ |
501 | cmd = scsi_host_alloc_command(shost, gfp_mask); |
502 | if (!cmd) { |
503 | scsi_put_host_cmd_pool(gfp_mask); |
504 | shost->cmd_pool = NULL; |
505 | return -ENOMEM; |
506 | } |
507 | list_add(&cmd->list, &shost->free_list); |
508 | return 0; |
509 | } |
510 | |
511 | /** |
512 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. |
513 | * @shost: host whose freelist is going to be destroyed |
514 | */ |
515 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) |
516 | { |
517 | /* |
518 | * If cmd_pool is NULL the free list was not initialized, so |
519 | * do not attempt to release resources. |
520 | */ |
521 | if (!shost->cmd_pool) |
522 | return; |
523 | |
524 | while (!list_empty(&shost->free_list)) { |
525 | struct scsi_cmnd *cmd; |
526 | |
527 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); |
528 | list_del_init(&cmd->list); |
529 | scsi_pool_free_command(shost->cmd_pool, cmd); |
530 | } |
531 | shost->cmd_pool = NULL; |
532 | scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL); |
533 | } |
534 | |
535 | #ifdef CONFIG_SCSI_LOGGING |
536 | void scsi_log_send(struct scsi_cmnd *cmd) |
537 | { |
538 | unsigned int level; |
539 | |
540 | /* |
541 | * If ML QUEUE log level is greater than or equal to: |
542 | * |
543 | * 1: nothing (match completion) |
544 | * |
545 | * 2: log opcode + command of all commands |
546 | * |
547 | * 3: same as 2 plus dump cmd address |
548 | * |
549 | * 4: same as 3 plus dump extra junk |
550 | */ |
551 | if (unlikely(scsi_logging_level)) { |
552 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, |
553 | SCSI_LOG_MLQUEUE_BITS); |
554 | if (level > 1) { |
555 | scmd_printk(KERN_INFO, cmd, "Send: "); |
556 | if (level > 2) |
557 | printk("0x%p ", cmd); |
558 | printk("\n"); |
559 | scsi_print_command(cmd); |
560 | if (level > 3) { |
561 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," |
562 | " queuecommand 0x%p\n", |
563 | scsi_sglist(cmd), scsi_bufflen(cmd), |
564 | cmd->device->host->hostt->queuecommand); |
565 | |
566 | } |
567 | } |
568 | } |
569 | } |
570 | |
571 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) |
572 | { |
573 | unsigned int level; |
574 | |
575 | /* |
576 | * If ML COMPLETE log level is greater than or equal to: |
577 | * |
578 | * 1: log disposition, result, opcode + command, and conditionally |
579 | * sense data for failures or non SUCCESS dispositions. |
580 | * |
581 | * 2: same as 1 but for all command completions. |
582 | * |
583 | * 3: same as 2 plus dump cmd address |
584 | * |
585 | * 4: same as 3 plus dump extra junk |
586 | */ |
587 | if (unlikely(scsi_logging_level)) { |
588 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, |
589 | SCSI_LOG_MLCOMPLETE_BITS); |
590 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || |
591 | (level > 1)) { |
592 | scmd_printk(KERN_INFO, cmd, "Done: "); |
593 | if (level > 2) |
594 | printk("0x%p ", cmd); |
595 | /* |
596 | * Dump truncated values, so we usually fit within |
597 | * 80 chars. |
598 | */ |
599 | switch (disposition) { |
600 | case SUCCESS: |
601 | printk("SUCCESS\n"); |
602 | break; |
603 | case NEEDS_RETRY: |
604 | printk("RETRY\n"); |
605 | break; |
606 | case ADD_TO_MLQUEUE: |
607 | printk("MLQUEUE\n"); |
608 | break; |
609 | case FAILED: |
610 | printk("FAILED\n"); |
611 | break; |
612 | case TIMEOUT_ERROR: |
613 | /* |
614 | * If called via scsi_times_out. |
615 | */ |
616 | printk("TIMEOUT\n"); |
617 | break; |
618 | default: |
619 | printk("UNKNOWN\n"); |
620 | } |
621 | scsi_print_result(cmd); |
622 | scsi_print_command(cmd); |
623 | if (status_byte(cmd->result) & CHECK_CONDITION) |
624 | scsi_print_sense("", cmd); |
625 | if (level > 3) |
626 | scmd_printk(KERN_INFO, cmd, |
627 | "scsi host busy %d failed %d\n", |
628 | cmd->device->host->host_busy, |
629 | cmd->device->host->host_failed); |
630 | } |
631 | } |
632 | } |
633 | #endif |
634 | |
635 | /** |
636 | * scsi_cmd_get_serial - Assign a serial number to a command |
637 | * @host: the scsi host |
638 | * @cmd: command to assign serial number to |
639 | * |
640 | * Description: a serial number identifies a request for error recovery |
641 | * and debugging purposes. Protected by the Host_Lock of host. |
642 | */ |
643 | void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) |
644 | { |
645 | cmd->serial_number = host->cmd_serial_number++; |
646 | if (cmd->serial_number == 0) |
647 | cmd->serial_number = host->cmd_serial_number++; |
648 | } |
649 | EXPORT_SYMBOL(scsi_cmd_get_serial); |
650 | |
651 | /** |
652 | * scsi_dispatch_command - Dispatch a command to the low-level driver. |
653 | * @cmd: command block we are dispatching. |
654 | * |
655 | * Return: nonzero return request was rejected and device's queue needs to be |
656 | * plugged. |
657 | */ |
658 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) |
659 | { |
660 | struct Scsi_Host *host = cmd->device->host; |
661 | unsigned long timeout; |
662 | int rtn = 0; |
663 | |
664 | atomic_inc(&cmd->device->iorequest_cnt); |
665 | |
666 | /* check if the device is still usable */ |
667 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { |
668 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT |
669 | * returns an immediate error upwards, and signals |
670 | * that the device is no longer present */ |
671 | cmd->result = DID_NO_CONNECT << 16; |
672 | scsi_done(cmd); |
673 | /* return 0 (because the command has been processed) */ |
674 | goto out; |
675 | } |
676 | |
677 | /* Check to see if the scsi lld made this device blocked. */ |
678 | if (unlikely(scsi_device_blocked(cmd->device))) { |
679 | /* |
680 | * in blocked state, the command is just put back on |
681 | * the device queue. The suspend state has already |
682 | * blocked the queue so future requests should not |
683 | * occur until the device transitions out of the |
684 | * suspend state. |
685 | */ |
686 | |
687 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
688 | |
689 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); |
690 | |
691 | /* |
692 | * NOTE: rtn is still zero here because we don't need the |
693 | * queue to be plugged on return (it's already stopped) |
694 | */ |
695 | goto out; |
696 | } |
697 | |
698 | /* |
699 | * If SCSI-2 or lower, store the LUN value in cmnd. |
700 | */ |
701 | if (cmd->device->scsi_level <= SCSI_2 && |
702 | cmd->device->scsi_level != SCSI_UNKNOWN) { |
703 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
704 | (cmd->device->lun << 5 & 0xe0); |
705 | } |
706 | |
707 | /* |
708 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so |
709 | * we can avoid the drive not being ready. |
710 | */ |
711 | timeout = host->last_reset + MIN_RESET_DELAY; |
712 | |
713 | if (host->resetting && time_before(jiffies, timeout)) { |
714 | int ticks_remaining = timeout - jiffies; |
715 | /* |
716 | * NOTE: This may be executed from within an interrupt |
717 | * handler! This is bad, but for now, it'll do. The irq |
718 | * level of the interrupt handler has been masked out by the |
719 | * platform dependent interrupt handling code already, so the |
720 | * sti() here will not cause another call to the SCSI host's |
721 | * interrupt handler (assuming there is one irq-level per |
722 | * host). |
723 | */ |
724 | while (--ticks_remaining >= 0) |
725 | mdelay(1 + 999 / HZ); |
726 | host->resetting = 0; |
727 | } |
728 | |
729 | scsi_log_send(cmd); |
730 | |
731 | /* |
732 | * Before we queue this command, check if the command |
733 | * length exceeds what the host adapter can handle. |
734 | */ |
735 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { |
736 | SCSI_LOG_MLQUEUE(3, |
737 | printk("queuecommand : command too long. " |
738 | "cdb_size=%d host->max_cmd_len=%d\n", |
739 | cmd->cmd_len, cmd->device->host->max_cmd_len)); |
740 | cmd->result = (DID_ABORT << 16); |
741 | |
742 | scsi_done(cmd); |
743 | goto out; |
744 | } |
745 | |
746 | if (unlikely(host->shost_state == SHOST_DEL)) { |
747 | cmd->result = (DID_NO_CONNECT << 16); |
748 | scsi_done(cmd); |
749 | } else { |
750 | trace_scsi_dispatch_cmd_start(cmd); |
751 | cmd->scsi_done = scsi_done; |
752 | rtn = host->hostt->queuecommand(host, cmd); |
753 | } |
754 | |
755 | if (rtn) { |
756 | trace_scsi_dispatch_cmd_error(cmd, rtn); |
757 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && |
758 | rtn != SCSI_MLQUEUE_TARGET_BUSY) |
759 | rtn = SCSI_MLQUEUE_HOST_BUSY; |
760 | |
761 | scsi_queue_insert(cmd, rtn); |
762 | |
763 | SCSI_LOG_MLQUEUE(3, |
764 | printk("queuecommand : request rejected\n")); |
765 | } |
766 | |
767 | out: |
768 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); |
769 | return rtn; |
770 | } |
771 | |
772 | /** |
773 | * scsi_done - Enqueue the finished SCSI command into the done queue. |
774 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives |
775 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. |
776 | * |
777 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
778 | * which regains ownership of the SCSI command (de facto) from a LLDD, and |
779 | * enqueues the command to the done queue for further processing. |
780 | * |
781 | * This is the producer of the done queue who enqueues at the tail. |
782 | * |
783 | * This function is interrupt context safe. |
784 | */ |
785 | static void scsi_done(struct scsi_cmnd *cmd) |
786 | { |
787 | trace_scsi_dispatch_cmd_done(cmd); |
788 | blk_complete_request(cmd->request); |
789 | } |
790 | |
791 | /** |
792 | * scsi_finish_command - cleanup and pass command back to upper layer |
793 | * @cmd: the command |
794 | * |
795 | * Description: Pass command off to upper layer for finishing of I/O |
796 | * request, waking processes that are waiting on results, |
797 | * etc. |
798 | */ |
799 | void scsi_finish_command(struct scsi_cmnd *cmd) |
800 | { |
801 | struct scsi_device *sdev = cmd->device; |
802 | struct scsi_target *starget = scsi_target(sdev); |
803 | struct Scsi_Host *shost = sdev->host; |
804 | struct scsi_driver *drv; |
805 | unsigned int good_bytes; |
806 | |
807 | scsi_device_unbusy(sdev); |
808 | |
809 | /* |
810 | * Clear the flags which say that the device/host is no longer |
811 | * capable of accepting new commands. These are set in scsi_queue.c |
812 | * for both the queue full condition on a device, and for a |
813 | * host full condition on the host. |
814 | * |
815 | * XXX(hch): What about locking? |
816 | */ |
817 | shost->host_blocked = 0; |
818 | starget->target_blocked = 0; |
819 | sdev->device_blocked = 0; |
820 | |
821 | /* |
822 | * If we have valid sense information, then some kind of recovery |
823 | * must have taken place. Make a note of this. |
824 | */ |
825 | if (SCSI_SENSE_VALID(cmd)) |
826 | cmd->result |= (DRIVER_SENSE << 24); |
827 | |
828 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
829 | "Notifying upper driver of completion " |
830 | "(result %x)\n", cmd->result)); |
831 | |
832 | good_bytes = scsi_bufflen(cmd); |
833 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { |
834 | int old_good_bytes = good_bytes; |
835 | drv = scsi_cmd_to_driver(cmd); |
836 | if (drv->done) |
837 | good_bytes = drv->done(cmd); |
838 | /* |
839 | * USB may not give sense identifying bad sector and |
840 | * simply return a residue instead, so subtract off the |
841 | * residue if drv->done() error processing indicates no |
842 | * change to the completion length. |
843 | */ |
844 | if (good_bytes == old_good_bytes) |
845 | good_bytes -= scsi_get_resid(cmd); |
846 | } |
847 | scsi_io_completion(cmd, good_bytes); |
848 | } |
849 | EXPORT_SYMBOL(scsi_finish_command); |
850 | |
851 | /** |
852 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth |
853 | * @sdev: SCSI Device in question |
854 | * @tagged: Do we use tagged queueing (non-0) or do we treat |
855 | * this device as an untagged device (0) |
856 | * @tags: Number of tags allowed if tagged queueing enabled, |
857 | * or number of commands the low level driver can |
858 | * queue up in non-tagged mode (as per cmd_per_lun). |
859 | * |
860 | * Returns: Nothing |
861 | * |
862 | * Lock Status: None held on entry |
863 | * |
864 | * Notes: Low level drivers may call this at any time and we will do |
865 | * the right thing depending on whether or not the device is |
866 | * currently active and whether or not it even has the |
867 | * command blocks built yet. |
868 | */ |
869 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) |
870 | { |
871 | unsigned long flags; |
872 | |
873 | /* |
874 | * refuse to set tagged depth to an unworkable size |
875 | */ |
876 | if (tags <= 0) |
877 | return; |
878 | |
879 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); |
880 | |
881 | /* |
882 | * Check to see if the queue is managed by the block layer. |
883 | * If it is, and we fail to adjust the depth, exit. |
884 | * |
885 | * Do not resize the tag map if it is a host wide share bqt, |
886 | * because the size should be the hosts's can_queue. If there |
887 | * is more IO than the LLD's can_queue (so there are not enuogh |
888 | * tags) request_fn's host queue ready check will handle it. |
889 | */ |
890 | if (!sdev->host->bqt) { |
891 | if (blk_queue_tagged(sdev->request_queue) && |
892 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) |
893 | goto out; |
894 | } |
895 | |
896 | sdev->queue_depth = tags; |
897 | switch (tagged) { |
898 | case MSG_ORDERED_TAG: |
899 | sdev->ordered_tags = 1; |
900 | sdev->simple_tags = 1; |
901 | break; |
902 | case MSG_SIMPLE_TAG: |
903 | sdev->ordered_tags = 0; |
904 | sdev->simple_tags = 1; |
905 | break; |
906 | default: |
907 | sdev_printk(KERN_WARNING, sdev, |
908 | "scsi_adjust_queue_depth, bad queue type, " |
909 | "disabled\n"); |
910 | case 0: |
911 | sdev->ordered_tags = sdev->simple_tags = 0; |
912 | sdev->queue_depth = tags; |
913 | break; |
914 | } |
915 | out: |
916 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
917 | } |
918 | EXPORT_SYMBOL(scsi_adjust_queue_depth); |
919 | |
920 | /** |
921 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth |
922 | * @sdev: SCSI Device in question |
923 | * @depth: Current number of outstanding SCSI commands on this device, |
924 | * not counting the one returned as QUEUE_FULL. |
925 | * |
926 | * Description: This function will track successive QUEUE_FULL events on a |
927 | * specific SCSI device to determine if and when there is a |
928 | * need to adjust the queue depth on the device. |
929 | * |
930 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
931 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
932 | * as the untagged command depth |
933 | * |
934 | * Lock Status: None held on entry |
935 | * |
936 | * Notes: Low level drivers may call this at any time and we will do |
937 | * "The Right Thing." We are interrupt context safe. |
938 | */ |
939 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) |
940 | { |
941 | |
942 | /* |
943 | * Don't let QUEUE_FULLs on the same |
944 | * jiffies count, they could all be from |
945 | * same event. |
946 | */ |
947 | if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) |
948 | return 0; |
949 | |
950 | sdev->last_queue_full_time = jiffies; |
951 | if (sdev->last_queue_full_depth != depth) { |
952 | sdev->last_queue_full_count = 1; |
953 | sdev->last_queue_full_depth = depth; |
954 | } else { |
955 | sdev->last_queue_full_count++; |
956 | } |
957 | |
958 | if (sdev->last_queue_full_count <= 10) |
959 | return 0; |
960 | if (sdev->last_queue_full_depth < 8) { |
961 | /* Drop back to untagged */ |
962 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); |
963 | return -1; |
964 | } |
965 | |
966 | if (sdev->ordered_tags) |
967 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); |
968 | else |
969 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); |
970 | return depth; |
971 | } |
972 | EXPORT_SYMBOL(scsi_track_queue_full); |
973 | |
974 | /** |
975 | * scsi_vpd_inquiry - Request a device provide us with a VPD page |
976 | * @sdev: The device to ask |
977 | * @buffer: Where to put the result |
978 | * @page: Which Vital Product Data to return |
979 | * @len: The length of the buffer |
980 | * |
981 | * This is an internal helper function. You probably want to use |
982 | * scsi_get_vpd_page instead. |
983 | * |
984 | * Returns 0 on success or a negative error number. |
985 | */ |
986 | static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, |
987 | u8 page, unsigned len) |
988 | { |
989 | int result; |
990 | unsigned char cmd[16]; |
991 | |
992 | cmd[0] = INQUIRY; |
993 | cmd[1] = 1; /* EVPD */ |
994 | cmd[2] = page; |
995 | cmd[3] = len >> 8; |
996 | cmd[4] = len & 0xff; |
997 | cmd[5] = 0; /* Control byte */ |
998 | |
999 | /* |
1000 | * I'm not convinced we need to try quite this hard to get VPD, but |
1001 | * all the existing users tried this hard. |
1002 | */ |
1003 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, |
1004 | len, NULL, 30 * HZ, 3, NULL); |
1005 | if (result) |
1006 | return result; |
1007 | |
1008 | /* Sanity check that we got the page back that we asked for */ |
1009 | if (buffer[1] != page) |
1010 | return -EIO; |
1011 | |
1012 | return 0; |
1013 | } |
1014 | |
1015 | /** |
1016 | * scsi_get_vpd_page - Get Vital Product Data from a SCSI device |
1017 | * @sdev: The device to ask |
1018 | * @page: Which Vital Product Data to return |
1019 | * @buf: where to store the VPD |
1020 | * @buf_len: number of bytes in the VPD buffer area |
1021 | * |
1022 | * SCSI devices may optionally supply Vital Product Data. Each 'page' |
1023 | * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). |
1024 | * If the device supports this VPD page, this routine returns a pointer |
1025 | * to a buffer containing the data from that page. The caller is |
1026 | * responsible for calling kfree() on this pointer when it is no longer |
1027 | * needed. If we cannot retrieve the VPD page this routine returns %NULL. |
1028 | */ |
1029 | int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, |
1030 | int buf_len) |
1031 | { |
1032 | int i, result; |
1033 | |
1034 | /* Ask for all the pages supported by this device */ |
1035 | result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); |
1036 | if (result) |
1037 | goto fail; |
1038 | |
1039 | /* If the user actually wanted this page, we can skip the rest */ |
1040 | if (page == 0) |
1041 | return 0; |
1042 | |
1043 | for (i = 0; i < min((int)buf[3], buf_len - 4); i++) |
1044 | if (buf[i + 4] == page) |
1045 | goto found; |
1046 | |
1047 | if (i < buf[3] && i >= buf_len - 4) |
1048 | /* ran off the end of the buffer, give us benefit of doubt */ |
1049 | goto found; |
1050 | /* The device claims it doesn't support the requested page */ |
1051 | goto fail; |
1052 | |
1053 | found: |
1054 | result = scsi_vpd_inquiry(sdev, buf, page, buf_len); |
1055 | if (result) |
1056 | goto fail; |
1057 | |
1058 | return 0; |
1059 | |
1060 | fail: |
1061 | return -EINVAL; |
1062 | } |
1063 | EXPORT_SYMBOL_GPL(scsi_get_vpd_page); |
1064 | |
1065 | /** |
1066 | * scsi_report_opcode - Find out if a given command opcode is supported |
1067 | * @sdev: scsi device to query |
1068 | * @buffer: scratch buffer (must be at least 20 bytes long) |
1069 | * @len: length of buffer |
1070 | * @opcode: opcode for command to look up |
1071 | * |
1072 | * Uses the REPORT SUPPORTED OPERATION CODES to look up the given |
1073 | * opcode. Returns 0 if RSOC fails or if the command opcode is |
1074 | * unsupported. Returns 1 if the device claims to support the command. |
1075 | */ |
1076 | int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, |
1077 | unsigned int len, unsigned char opcode) |
1078 | { |
1079 | unsigned char cmd[16]; |
1080 | struct scsi_sense_hdr sshdr; |
1081 | int result; |
1082 | |
1083 | if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) |
1084 | return 0; |
1085 | |
1086 | memset(cmd, 0, 16); |
1087 | cmd[0] = MAINTENANCE_IN; |
1088 | cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; |
1089 | cmd[2] = 1; /* One command format */ |
1090 | cmd[3] = opcode; |
1091 | put_unaligned_be32(len, &cmd[6]); |
1092 | memset(buffer, 0, len); |
1093 | |
1094 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
1095 | &sshdr, 30 * HZ, 3, NULL); |
1096 | |
1097 | if (result && scsi_sense_valid(&sshdr) && |
1098 | sshdr.sense_key == ILLEGAL_REQUEST && |
1099 | (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) |
1100 | return 0; |
1101 | |
1102 | if ((buffer[1] & 3) == 3) /* Command supported */ |
1103 | return 1; |
1104 | |
1105 | return 0; |
1106 | } |
1107 | EXPORT_SYMBOL(scsi_report_opcode); |
1108 | |
1109 | /** |
1110 | * scsi_device_get - get an additional reference to a scsi_device |
1111 | * @sdev: device to get a reference to |
1112 | * |
1113 | * Description: Gets a reference to the scsi_device and increments the use count |
1114 | * of the underlying LLDD module. You must hold host_lock of the |
1115 | * parent Scsi_Host or already have a reference when calling this. |
1116 | */ |
1117 | int scsi_device_get(struct scsi_device *sdev) |
1118 | { |
1119 | if (sdev->sdev_state == SDEV_DEL) |
1120 | return -ENXIO; |
1121 | if (!get_device(&sdev->sdev_gendev)) |
1122 | return -ENXIO; |
1123 | /* We can fail this if we're doing SCSI operations |
1124 | * from module exit (like cache flush) */ |
1125 | try_module_get(sdev->host->hostt->module); |
1126 | |
1127 | return 0; |
1128 | } |
1129 | EXPORT_SYMBOL(scsi_device_get); |
1130 | |
1131 | /** |
1132 | * scsi_device_put - release a reference to a scsi_device |
1133 | * @sdev: device to release a reference on. |
1134 | * |
1135 | * Description: Release a reference to the scsi_device and decrements the use |
1136 | * count of the underlying LLDD module. The device is freed once the last |
1137 | * user vanishes. |
1138 | */ |
1139 | void scsi_device_put(struct scsi_device *sdev) |
1140 | { |
1141 | #ifdef CONFIG_MODULE_UNLOAD |
1142 | struct module *module = sdev->host->hostt->module; |
1143 | |
1144 | /* The module refcount will be zero if scsi_device_get() |
1145 | * was called from a module removal routine */ |
1146 | if (module && module_refcount(module) != 0) |
1147 | module_put(module); |
1148 | #endif |
1149 | put_device(&sdev->sdev_gendev); |
1150 | } |
1151 | EXPORT_SYMBOL(scsi_device_put); |
1152 | |
1153 | /* helper for shost_for_each_device, see that for documentation */ |
1154 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
1155 | struct scsi_device *prev) |
1156 | { |
1157 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); |
1158 | struct scsi_device *next = NULL; |
1159 | unsigned long flags; |
1160 | |
1161 | spin_lock_irqsave(shost->host_lock, flags); |
1162 | while (list->next != &shost->__devices) { |
1163 | next = list_entry(list->next, struct scsi_device, siblings); |
1164 | /* skip devices that we can't get a reference to */ |
1165 | if (!scsi_device_get(next)) |
1166 | break; |
1167 | next = NULL; |
1168 | list = list->next; |
1169 | } |
1170 | spin_unlock_irqrestore(shost->host_lock, flags); |
1171 | |
1172 | if (prev) |
1173 | scsi_device_put(prev); |
1174 | return next; |
1175 | } |
1176 | EXPORT_SYMBOL(__scsi_iterate_devices); |
1177 | |
1178 | /** |
1179 | * starget_for_each_device - helper to walk all devices of a target |
1180 | * @starget: target whose devices we want to iterate over. |
1181 | * @data: Opaque passed to each function call. |
1182 | * @fn: Function to call on each device |
1183 | * |
1184 | * This traverses over each device of @starget. The devices have |
1185 | * a reference that must be released by scsi_host_put when breaking |
1186 | * out of the loop. |
1187 | */ |
1188 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1189 | void (*fn)(struct scsi_device *, void *)) |
1190 | { |
1191 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
1192 | struct scsi_device *sdev; |
1193 | |
1194 | shost_for_each_device(sdev, shost) { |
1195 | if ((sdev->channel == starget->channel) && |
1196 | (sdev->id == starget->id)) |
1197 | fn(sdev, data); |
1198 | } |
1199 | } |
1200 | EXPORT_SYMBOL(starget_for_each_device); |
1201 | |
1202 | /** |
1203 | * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
1204 | * @starget: target whose devices we want to iterate over. |
1205 | * @data: parameter for callback @fn() |
1206 | * @fn: callback function that is invoked for each device |
1207 | * |
1208 | * This traverses over each device of @starget. It does _not_ |
1209 | * take a reference on the scsi_device, so the whole loop must be |
1210 | * protected by shost->host_lock. |
1211 | * |
1212 | * Note: The only reason why drivers would want to use this is because |
1213 | * they need to access the device list in irq context. Otherwise you |
1214 | * really want to use starget_for_each_device instead. |
1215 | **/ |
1216 | void __starget_for_each_device(struct scsi_target *starget, void *data, |
1217 | void (*fn)(struct scsi_device *, void *)) |
1218 | { |
1219 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
1220 | struct scsi_device *sdev; |
1221 | |
1222 | __shost_for_each_device(sdev, shost) { |
1223 | if ((sdev->channel == starget->channel) && |
1224 | (sdev->id == starget->id)) |
1225 | fn(sdev, data); |
1226 | } |
1227 | } |
1228 | EXPORT_SYMBOL(__starget_for_each_device); |
1229 | |
1230 | /** |
1231 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) |
1232 | * @starget: SCSI target pointer |
1233 | * @lun: SCSI Logical Unit Number |
1234 | * |
1235 | * Description: Looks up the scsi_device with the specified @lun for a given |
1236 | * @starget. The returned scsi_device does not have an additional |
1237 | * reference. You must hold the host's host_lock over this call and |
1238 | * any access to the returned scsi_device. A scsi_device in state |
1239 | * SDEV_DEL is skipped. |
1240 | * |
1241 | * Note: The only reason why drivers should use this is because |
1242 | * they need to access the device list in irq context. Otherwise you |
1243 | * really want to use scsi_device_lookup_by_target instead. |
1244 | **/ |
1245 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, |
1246 | uint lun) |
1247 | { |
1248 | struct scsi_device *sdev; |
1249 | |
1250 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { |
1251 | if (sdev->sdev_state == SDEV_DEL) |
1252 | continue; |
1253 | if (sdev->lun ==lun) |
1254 | return sdev; |
1255 | } |
1256 | |
1257 | return NULL; |
1258 | } |
1259 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); |
1260 | |
1261 | /** |
1262 | * scsi_device_lookup_by_target - find a device given the target |
1263 | * @starget: SCSI target pointer |
1264 | * @lun: SCSI Logical Unit Number |
1265 | * |
1266 | * Description: Looks up the scsi_device with the specified @lun for a given |
1267 | * @starget. The returned scsi_device has an additional reference that |
1268 | * needs to be released with scsi_device_put once you're done with it. |
1269 | **/ |
1270 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, |
1271 | uint lun) |
1272 | { |
1273 | struct scsi_device *sdev; |
1274 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
1275 | unsigned long flags; |
1276 | |
1277 | spin_lock_irqsave(shost->host_lock, flags); |
1278 | sdev = __scsi_device_lookup_by_target(starget, lun); |
1279 | if (sdev && scsi_device_get(sdev)) |
1280 | sdev = NULL; |
1281 | spin_unlock_irqrestore(shost->host_lock, flags); |
1282 | |
1283 | return sdev; |
1284 | } |
1285 | EXPORT_SYMBOL(scsi_device_lookup_by_target); |
1286 | |
1287 | /** |
1288 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1289 | * @shost: SCSI host pointer |
1290 | * @channel: SCSI channel (zero if only one channel) |
1291 | * @id: SCSI target number (physical unit number) |
1292 | * @lun: SCSI Logical Unit Number |
1293 | * |
1294 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1295 | * for a given host. The returned scsi_device does not have an additional |
1296 | * reference. You must hold the host's host_lock over this call and any access |
1297 | * to the returned scsi_device. |
1298 | * |
1299 | * Note: The only reason why drivers would want to use this is because |
1300 | * they need to access the device list in irq context. Otherwise you |
1301 | * really want to use scsi_device_lookup instead. |
1302 | **/ |
1303 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, |
1304 | uint channel, uint id, uint lun) |
1305 | { |
1306 | struct scsi_device *sdev; |
1307 | |
1308 | list_for_each_entry(sdev, &shost->__devices, siblings) { |
1309 | if (sdev->channel == channel && sdev->id == id && |
1310 | sdev->lun ==lun) |
1311 | return sdev; |
1312 | } |
1313 | |
1314 | return NULL; |
1315 | } |
1316 | EXPORT_SYMBOL(__scsi_device_lookup); |
1317 | |
1318 | /** |
1319 | * scsi_device_lookup - find a device given the host |
1320 | * @shost: SCSI host pointer |
1321 | * @channel: SCSI channel (zero if only one channel) |
1322 | * @id: SCSI target number (physical unit number) |
1323 | * @lun: SCSI Logical Unit Number |
1324 | * |
1325 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1326 | * for a given host. The returned scsi_device has an additional reference that |
1327 | * needs to be released with scsi_device_put once you're done with it. |
1328 | **/ |
1329 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, |
1330 | uint channel, uint id, uint lun) |
1331 | { |
1332 | struct scsi_device *sdev; |
1333 | unsigned long flags; |
1334 | |
1335 | spin_lock_irqsave(shost->host_lock, flags); |
1336 | sdev = __scsi_device_lookup(shost, channel, id, lun); |
1337 | if (sdev && scsi_device_get(sdev)) |
1338 | sdev = NULL; |
1339 | spin_unlock_irqrestore(shost->host_lock, flags); |
1340 | |
1341 | return sdev; |
1342 | } |
1343 | EXPORT_SYMBOL(scsi_device_lookup); |
1344 | |
1345 | MODULE_DESCRIPTION("SCSI core"); |
1346 | MODULE_LICENSE("GPL"); |
1347 | |
1348 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); |
1349 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); |
1350 | |
1351 | static int __init init_scsi(void) |
1352 | { |
1353 | int error; |
1354 | |
1355 | error = scsi_init_queue(); |
1356 | if (error) |
1357 | return error; |
1358 | error = scsi_init_procfs(); |
1359 | if (error) |
1360 | goto cleanup_queue; |
1361 | error = scsi_init_devinfo(); |
1362 | if (error) |
1363 | goto cleanup_procfs; |
1364 | error = scsi_init_hosts(); |
1365 | if (error) |
1366 | goto cleanup_devlist; |
1367 | error = scsi_init_sysctl(); |
1368 | if (error) |
1369 | goto cleanup_hosts; |
1370 | error = scsi_sysfs_register(); |
1371 | if (error) |
1372 | goto cleanup_sysctl; |
1373 | |
1374 | scsi_netlink_init(); |
1375 | |
1376 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1377 | return 0; |
1378 | |
1379 | cleanup_sysctl: |
1380 | scsi_exit_sysctl(); |
1381 | cleanup_hosts: |
1382 | scsi_exit_hosts(); |
1383 | cleanup_devlist: |
1384 | scsi_exit_devinfo(); |
1385 | cleanup_procfs: |
1386 | scsi_exit_procfs(); |
1387 | cleanup_queue: |
1388 | scsi_exit_queue(); |
1389 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", |
1390 | -error); |
1391 | return error; |
1392 | } |
1393 | |
1394 | static void __exit exit_scsi(void) |
1395 | { |
1396 | scsi_netlink_exit(); |
1397 | scsi_sysfs_unregister(); |
1398 | scsi_exit_sysctl(); |
1399 | scsi_exit_hosts(); |
1400 | scsi_exit_devinfo(); |
1401 | scsi_exit_procfs(); |
1402 | scsi_exit_queue(); |
1403 | async_unregister_domain(&scsi_sd_probe_domain); |
1404 | } |
1405 | |
1406 | subsys_initcall(init_scsi); |
1407 | module_exit(exit_scsi); |
1408 |
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v2.6.34-rc5
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