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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> | |
43 | #include <linux/sched.h> | |
44 | #include <linux/timer.h> | |
45 | #include <linux/string.h> | |
46 | #include <linux/slab.h> | |
47 | #include <linux/blkdev.h> | |
48 | #include <linux/delay.h> | |
49 | #include <linux/init.h> | |
50 | #include <linux/completion.h> | |
51 | #include <linux/devfs_fs_kernel.h> | |
52 | #include <linux/unistd.h> | |
53 | #include <linux/spinlock.h> | |
54 | #include <linux/kmod.h> | |
55 | #include <linux/interrupt.h> | |
56 | #include <linux/notifier.h> | |
57 | #include <linux/cpu.h> | |
58 | ||
59 | #include <scsi/scsi.h> | |
60 | #include <scsi/scsi_cmnd.h> | |
61 | #include <scsi/scsi_dbg.h> | |
62 | #include <scsi/scsi_device.h> | |
63 | #include <scsi/scsi_eh.h> | |
64 | #include <scsi/scsi_host.h> | |
65 | #include <scsi/scsi_tcq.h> | |
66 | #include <scsi/scsi_request.h> | |
67 | ||
68 | #include "scsi_priv.h" | |
69 | #include "scsi_logging.h" | |
70 | ||
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 | ||
99 | const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] = { | |
100 | "Direct-Access ", | |
101 | "Sequential-Access", | |
102 | "Printer ", | |
103 | "Processor ", | |
104 | "WORM ", | |
105 | "CD-ROM ", | |
106 | "Scanner ", | |
107 | "Optical Device ", | |
108 | "Medium Changer ", | |
109 | "Communications ", | |
110 | "Unknown ", | |
111 | "Unknown ", | |
112 | "RAID ", | |
113 | "Enclosure ", | |
114 | }; | |
115 | EXPORT_SYMBOL(scsi_device_types); | |
116 | ||
117 | /* | |
118 | * Function: scsi_allocate_request | |
119 | * | |
120 | * Purpose: Allocate a request descriptor. | |
121 | * | |
122 | * Arguments: device - device for which we want a request | |
123 | * gfp_mask - allocation flags passed to kmalloc | |
124 | * | |
125 | * Lock status: No locks assumed to be held. This function is SMP-safe. | |
126 | * | |
127 | * Returns: Pointer to request block. | |
128 | */ | |
129 | struct scsi_request *scsi_allocate_request(struct scsi_device *sdev, | |
130 | int gfp_mask) | |
131 | { | |
132 | const int offset = ALIGN(sizeof(struct scsi_request), 4); | |
133 | const int size = offset + sizeof(struct request); | |
134 | struct scsi_request *sreq; | |
135 | ||
136 | sreq = kmalloc(size, gfp_mask); | |
137 | if (likely(sreq != NULL)) { | |
138 | memset(sreq, 0, size); | |
139 | sreq->sr_request = (struct request *)(((char *)sreq) + offset); | |
140 | sreq->sr_device = sdev; | |
141 | sreq->sr_host = sdev->host; | |
142 | sreq->sr_magic = SCSI_REQ_MAGIC; | |
143 | sreq->sr_data_direction = DMA_BIDIRECTIONAL; | |
144 | } | |
145 | ||
146 | return sreq; | |
147 | } | |
148 | EXPORT_SYMBOL(scsi_allocate_request); | |
149 | ||
150 | void __scsi_release_request(struct scsi_request *sreq) | |
151 | { | |
152 | struct request *req = sreq->sr_request; | |
153 | ||
154 | /* unlikely because the tag was usually ended earlier by the | |
155 | * mid-layer. However, for layering reasons ULD's don't end | |
156 | * the tag of commands they generate. */ | |
157 | if (unlikely(blk_rq_tagged(req))) { | |
158 | unsigned long flags; | |
159 | struct request_queue *q = req->q; | |
160 | ||
161 | spin_lock_irqsave(q->queue_lock, flags); | |
162 | blk_queue_end_tag(q, req); | |
163 | spin_unlock_irqrestore(q->queue_lock, flags); | |
164 | } | |
165 | ||
166 | ||
167 | if (likely(sreq->sr_command != NULL)) { | |
168 | struct scsi_cmnd *cmd = sreq->sr_command; | |
169 | ||
170 | sreq->sr_command = NULL; | |
171 | scsi_next_command(cmd); | |
172 | } | |
173 | } | |
174 | ||
175 | /* | |
176 | * Function: scsi_release_request | |
177 | * | |
178 | * Purpose: Release a request descriptor. | |
179 | * | |
180 | * Arguments: sreq - request to release | |
181 | * | |
182 | * Lock status: No locks assumed to be held. This function is SMP-safe. | |
183 | */ | |
184 | void scsi_release_request(struct scsi_request *sreq) | |
185 | { | |
186 | __scsi_release_request(sreq); | |
187 | kfree(sreq); | |
188 | } | |
189 | EXPORT_SYMBOL(scsi_release_request); | |
190 | ||
191 | struct scsi_host_cmd_pool { | |
192 | kmem_cache_t *slab; | |
193 | unsigned int users; | |
194 | char *name; | |
195 | unsigned int slab_flags; | |
196 | unsigned int gfp_mask; | |
197 | }; | |
198 | ||
199 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
200 | .name = "scsi_cmd_cache", | |
201 | .slab_flags = SLAB_HWCACHE_ALIGN, | |
202 | }; | |
203 | ||
204 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
205 | .name = "scsi_cmd_cache(DMA)", | |
206 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, | |
207 | .gfp_mask = __GFP_DMA, | |
208 | }; | |
209 | ||
210 | static DECLARE_MUTEX(host_cmd_pool_mutex); | |
211 | ||
212 | static struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, | |
213 | int gfp_mask) | |
214 | { | |
215 | struct scsi_cmnd *cmd; | |
216 | ||
217 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
218 | gfp_mask | shost->cmd_pool->gfp_mask); | |
219 | ||
220 | if (unlikely(!cmd)) { | |
221 | unsigned long flags; | |
222 | ||
223 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
224 | if (likely(!list_empty(&shost->free_list))) { | |
225 | cmd = list_entry(shost->free_list.next, | |
226 | struct scsi_cmnd, list); | |
227 | list_del_init(&cmd->list); | |
228 | } | |
229 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
230 | } | |
231 | ||
232 | return cmd; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Function: scsi_get_command() | |
237 | * | |
238 | * Purpose: Allocate and setup a scsi command block | |
239 | * | |
240 | * Arguments: dev - parent scsi device | |
241 | * gfp_mask- allocator flags | |
242 | * | |
243 | * Returns: The allocated scsi command structure. | |
244 | */ | |
245 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, int gfp_mask) | |
246 | { | |
247 | struct scsi_cmnd *cmd; | |
248 | ||
249 | /* Bail if we can't get a reference to the device */ | |
250 | if (!get_device(&dev->sdev_gendev)) | |
251 | return NULL; | |
252 | ||
253 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
254 | ||
255 | if (likely(cmd != NULL)) { | |
256 | unsigned long flags; | |
257 | ||
258 | memset(cmd, 0, sizeof(*cmd)); | |
259 | cmd->device = dev; | |
260 | cmd->state = SCSI_STATE_UNUSED; | |
261 | cmd->owner = SCSI_OWNER_NOBODY; | |
262 | init_timer(&cmd->eh_timeout); | |
263 | INIT_LIST_HEAD(&cmd->list); | |
264 | spin_lock_irqsave(&dev->list_lock, flags); | |
265 | list_add_tail(&cmd->list, &dev->cmd_list); | |
266 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
267 | } else | |
268 | put_device(&dev->sdev_gendev); | |
269 | ||
270 | return cmd; | |
271 | } | |
272 | EXPORT_SYMBOL(scsi_get_command); | |
273 | ||
274 | /* | |
275 | * Function: scsi_put_command() | |
276 | * | |
277 | * Purpose: Free a scsi command block | |
278 | * | |
279 | * Arguments: cmd - command block to free | |
280 | * | |
281 | * Returns: Nothing. | |
282 | * | |
283 | * Notes: The command must not belong to any lists. | |
284 | */ | |
285 | void scsi_put_command(struct scsi_cmnd *cmd) | |
286 | { | |
287 | struct scsi_device *sdev = cmd->device; | |
288 | struct Scsi_Host *shost = sdev->host; | |
289 | unsigned long flags; | |
290 | ||
291 | /* serious error if the command hasn't come from a device list */ | |
292 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
293 | BUG_ON(list_empty(&cmd->list)); | |
294 | list_del_init(&cmd->list); | |
295 | spin_unlock(&cmd->device->list_lock); | |
296 | /* changing locks here, don't need to restore the irq state */ | |
297 | spin_lock(&shost->free_list_lock); | |
298 | if (unlikely(list_empty(&shost->free_list))) { | |
299 | list_add(&cmd->list, &shost->free_list); | |
300 | cmd = NULL; | |
301 | } | |
302 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
303 | ||
304 | if (likely(cmd != NULL)) | |
305 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
306 | ||
307 | put_device(&sdev->sdev_gendev); | |
308 | } | |
309 | EXPORT_SYMBOL(scsi_put_command); | |
310 | ||
311 | /* | |
312 | * Function: scsi_setup_command_freelist() | |
313 | * | |
314 | * Purpose: Setup the command freelist for a scsi host. | |
315 | * | |
316 | * Arguments: shost - host to allocate the freelist for. | |
317 | * | |
318 | * Returns: Nothing. | |
319 | */ | |
320 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
321 | { | |
322 | struct scsi_host_cmd_pool *pool; | |
323 | struct scsi_cmnd *cmd; | |
324 | ||
325 | spin_lock_init(&shost->free_list_lock); | |
326 | INIT_LIST_HEAD(&shost->free_list); | |
327 | ||
328 | /* | |
329 | * Select a command slab for this host and create it if not | |
330 | * yet existant. | |
331 | */ | |
332 | down(&host_cmd_pool_mutex); | |
333 | pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool); | |
334 | if (!pool->users) { | |
335 | pool->slab = kmem_cache_create(pool->name, | |
336 | sizeof(struct scsi_cmnd), 0, | |
337 | pool->slab_flags, NULL, NULL); | |
338 | if (!pool->slab) | |
339 | goto fail; | |
340 | } | |
341 | ||
342 | pool->users++; | |
343 | shost->cmd_pool = pool; | |
344 | up(&host_cmd_pool_mutex); | |
345 | ||
346 | /* | |
347 | * Get one backup command for this host. | |
348 | */ | |
349 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
350 | GFP_KERNEL | shost->cmd_pool->gfp_mask); | |
351 | if (!cmd) | |
352 | goto fail2; | |
353 | list_add(&cmd->list, &shost->free_list); | |
354 | return 0; | |
355 | ||
356 | fail2: | |
357 | if (!--pool->users) | |
358 | kmem_cache_destroy(pool->slab); | |
359 | return -ENOMEM; | |
360 | fail: | |
361 | up(&host_cmd_pool_mutex); | |
362 | return -ENOMEM; | |
363 | ||
364 | } | |
365 | ||
366 | /* | |
367 | * Function: scsi_destroy_command_freelist() | |
368 | * | |
369 | * Purpose: Release the command freelist for a scsi host. | |
370 | * | |
371 | * Arguments: shost - host that's freelist is going to be destroyed | |
372 | */ | |
373 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
374 | { | |
375 | while (!list_empty(&shost->free_list)) { | |
376 | struct scsi_cmnd *cmd; | |
377 | ||
378 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
379 | list_del_init(&cmd->list); | |
380 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
381 | } | |
382 | ||
383 | down(&host_cmd_pool_mutex); | |
384 | if (!--shost->cmd_pool->users) | |
385 | kmem_cache_destroy(shost->cmd_pool->slab); | |
386 | up(&host_cmd_pool_mutex); | |
387 | } | |
388 | ||
389 | #ifdef CONFIG_SCSI_LOGGING | |
390 | void scsi_log_send(struct scsi_cmnd *cmd) | |
391 | { | |
392 | unsigned int level; | |
393 | struct scsi_device *sdev; | |
394 | ||
395 | /* | |
396 | * If ML QUEUE log level is greater than or equal to: | |
397 | * | |
398 | * 1: nothing (match completion) | |
399 | * | |
400 | * 2: log opcode + command of all commands | |
401 | * | |
402 | * 3: same as 2 plus dump cmd address | |
403 | * | |
404 | * 4: same as 3 plus dump extra junk | |
405 | */ | |
406 | if (unlikely(scsi_logging_level)) { | |
407 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
408 | SCSI_LOG_MLQUEUE_BITS); | |
409 | if (level > 1) { | |
410 | sdev = cmd->device; | |
411 | printk(KERN_INFO "scsi <%d:%d:%d:%d> send ", | |
412 | sdev->host->host_no, sdev->channel, sdev->id, | |
413 | sdev->lun); | |
414 | if (level > 2) | |
415 | printk("0x%p ", cmd); | |
416 | /* | |
417 | * spaces to match disposition and cmd->result | |
418 | * output in scsi_log_completion. | |
419 | */ | |
420 | printk(" "); | |
421 | scsi_print_command(cmd); | |
422 | if (level > 3) { | |
423 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
424 | " done = 0x%p, queuecommand 0x%p\n", | |
425 | cmd->buffer, cmd->bufflen, | |
426 | cmd->done, | |
427 | sdev->host->hostt->queuecommand); | |
428 | ||
429 | } | |
430 | } | |
431 | } | |
432 | } | |
433 | ||
434 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
435 | { | |
436 | unsigned int level; | |
437 | struct scsi_device *sdev; | |
438 | ||
439 | /* | |
440 | * If ML COMPLETE log level is greater than or equal to: | |
441 | * | |
442 | * 1: log disposition, result, opcode + command, and conditionally | |
443 | * sense data for failures or non SUCCESS dispositions. | |
444 | * | |
445 | * 2: same as 1 but for all command completions. | |
446 | * | |
447 | * 3: same as 2 plus dump cmd address | |
448 | * | |
449 | * 4: same as 3 plus dump extra junk | |
450 | */ | |
451 | if (unlikely(scsi_logging_level)) { | |
452 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
453 | SCSI_LOG_MLCOMPLETE_BITS); | |
454 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
455 | (level > 1)) { | |
456 | sdev = cmd->device; | |
457 | printk(KERN_INFO "scsi <%d:%d:%d:%d> done ", | |
458 | sdev->host->host_no, sdev->channel, sdev->id, | |
459 | sdev->lun); | |
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: | |
468 | printk("SUCCESS"); | |
469 | break; | |
470 | case NEEDS_RETRY: | |
471 | printk("RETRY "); | |
472 | break; | |
473 | case ADD_TO_MLQUEUE: | |
474 | printk("MLQUEUE"); | |
475 | break; | |
476 | case FAILED: | |
477 | printk("FAILED "); | |
478 | break; | |
479 | case TIMEOUT_ERROR: | |
480 | /* | |
481 | * If called via scsi_times_out. | |
482 | */ | |
483 | printk("TIMEOUT"); | |
484 | break; | |
485 | default: | |
486 | printk("UNKNOWN"); | |
487 | } | |
488 | printk(" %8x ", cmd->result); | |
489 | scsi_print_command(cmd); | |
490 | if (status_byte(cmd->result) & CHECK_CONDITION) { | |
491 | /* | |
492 | * XXX The print_sense formatting/prefix | |
493 | * doesn't match this function. | |
494 | */ | |
495 | scsi_print_sense("", cmd); | |
496 | } | |
497 | if (level > 3) { | |
498 | printk(KERN_INFO "scsi host busy %d failed %d\n", | |
499 | sdev->host->host_busy, | |
500 | sdev->host->host_failed); | |
501 | } | |
502 | } | |
503 | } | |
504 | } | |
505 | #endif | |
506 | ||
507 | /* | |
508 | * Assign a serial number and pid to the request for error recovery | |
509 | * and debugging purposes. Protected by the Host_Lock of host. | |
510 | */ | |
511 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
512 | { | |
513 | cmd->serial_number = host->cmd_serial_number++; | |
514 | if (cmd->serial_number == 0) | |
515 | cmd->serial_number = host->cmd_serial_number++; | |
516 | ||
517 | cmd->pid = host->cmd_pid++; | |
518 | if (cmd->pid == 0) | |
519 | cmd->pid = host->cmd_pid++; | |
520 | } | |
521 | ||
522 | /* | |
523 | * Function: scsi_dispatch_command | |
524 | * | |
525 | * Purpose: Dispatch a command to the low-level driver. | |
526 | * | |
527 | * Arguments: cmd - command block we are dispatching. | |
528 | * | |
529 | * Notes: | |
530 | */ | |
531 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
532 | { | |
533 | struct Scsi_Host *host = cmd->device->host; | |
534 | unsigned long flags = 0; | |
535 | unsigned long timeout; | |
536 | int rtn = 0; | |
537 | ||
538 | /* check if the device is still usable */ | |
539 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
540 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
541 | * returns an immediate error upwards, and signals | |
542 | * that the device is no longer present */ | |
543 | cmd->result = DID_NO_CONNECT << 16; | |
544 | atomic_inc(&cmd->device->iorequest_cnt); | |
545 | scsi_done(cmd); | |
546 | /* return 0 (because the command has been processed) */ | |
547 | goto out; | |
548 | } | |
549 | ||
550 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
551 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
552 | /* | |
553 | * in SDEV_BLOCK, the command is just put back on the device | |
554 | * queue. The suspend state has already blocked the queue so | |
555 | * future requests should not occur until the device | |
556 | * transitions out of the suspend state. | |
557 | */ | |
558 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
559 | ||
560 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
561 | ||
562 | /* | |
563 | * NOTE: rtn is still zero here because we don't need the | |
564 | * queue to be plugged on return (it's already stopped) | |
565 | */ | |
566 | goto out; | |
567 | } | |
568 | ||
569 | /* | |
570 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
571 | */ | |
572 | if (cmd->device->scsi_level <= SCSI_2) { | |
573 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | | |
574 | (cmd->device->lun << 5 & 0xe0); | |
575 | } | |
576 | ||
577 | /* | |
578 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
579 | * we can avoid the drive not being ready. | |
580 | */ | |
581 | timeout = host->last_reset + MIN_RESET_DELAY; | |
582 | ||
583 | if (host->resetting && time_before(jiffies, timeout)) { | |
584 | int ticks_remaining = timeout - jiffies; | |
585 | /* | |
586 | * NOTE: This may be executed from within an interrupt | |
587 | * handler! This is bad, but for now, it'll do. The irq | |
588 | * level of the interrupt handler has been masked out by the | |
589 | * platform dependent interrupt handling code already, so the | |
590 | * sti() here will not cause another call to the SCSI host's | |
591 | * interrupt handler (assuming there is one irq-level per | |
592 | * host). | |
593 | */ | |
594 | while (--ticks_remaining >= 0) | |
595 | mdelay(1 + 999 / HZ); | |
596 | host->resetting = 0; | |
597 | } | |
598 | ||
599 | /* | |
600 | * AK: unlikely race here: for some reason the timer could | |
601 | * expire before the serial number is set up below. | |
602 | */ | |
603 | scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out); | |
604 | ||
605 | scsi_log_send(cmd); | |
606 | ||
607 | /* | |
608 | * We will use a queued command if possible, otherwise we will | |
609 | * emulate the queuing and calling of completion function ourselves. | |
610 | */ | |
611 | ||
612 | cmd->state = SCSI_STATE_QUEUED; | |
613 | cmd->owner = SCSI_OWNER_LOWLEVEL; | |
614 | ||
615 | atomic_inc(&cmd->device->iorequest_cnt); | |
616 | ||
617 | /* | |
618 | * Before we queue this command, check if the command | |
619 | * length exceeds what the host adapter can handle. | |
620 | */ | |
621 | if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) { | |
622 | SCSI_LOG_MLQUEUE(3, | |
623 | printk("queuecommand : command too long.\n")); | |
624 | cmd->result = (DID_ABORT << 16); | |
625 | ||
626 | scsi_done(cmd); | |
627 | goto out; | |
628 | } | |
629 | ||
630 | spin_lock_irqsave(host->host_lock, flags); | |
631 | scsi_cmd_get_serial(host, cmd); | |
632 | ||
633 | if (unlikely(test_bit(SHOST_CANCEL, &host->shost_state))) { | |
634 | cmd->result = (DID_NO_CONNECT << 16); | |
635 | scsi_done(cmd); | |
636 | } else { | |
637 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
638 | } | |
639 | spin_unlock_irqrestore(host->host_lock, flags); | |
640 | if (rtn) { | |
641 | atomic_inc(&cmd->device->iodone_cnt); | |
642 | scsi_queue_insert(cmd, | |
643 | (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? | |
644 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
645 | SCSI_LOG_MLQUEUE(3, | |
646 | printk("queuecommand : request rejected\n")); | |
647 | } | |
648 | ||
649 | out: | |
650 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
651 | return rtn; | |
652 | } | |
653 | ||
654 | /* | |
655 | * Function: scsi_init_cmd_from_req | |
656 | * | |
657 | * Purpose: Queue a SCSI command | |
658 | * Purpose: Initialize a struct scsi_cmnd from a struct scsi_request | |
659 | * | |
660 | * Arguments: cmd - command descriptor. | |
661 | * sreq - Request from the queue. | |
662 | * | |
663 | * Lock status: None needed. | |
664 | * | |
665 | * Returns: Nothing. | |
666 | * | |
667 | * Notes: Mainly transfer data from the request structure to the | |
668 | * command structure. The request structure is allocated | |
669 | * using the normal memory allocator, and requests can pile | |
670 | * up to more or less any depth. The command structure represents | |
671 | * a consumable resource, as these are allocated into a pool | |
672 | * when the SCSI subsystem initializes. The preallocation is | |
673 | * required so that in low-memory situations a disk I/O request | |
674 | * won't cause the memory manager to try and write out a page. | |
675 | * The request structure is generally used by ioctls and character | |
676 | * devices. | |
677 | */ | |
678 | void scsi_init_cmd_from_req(struct scsi_cmnd *cmd, struct scsi_request *sreq) | |
679 | { | |
680 | sreq->sr_command = cmd; | |
681 | ||
682 | cmd->owner = SCSI_OWNER_MIDLEVEL; | |
683 | cmd->cmd_len = sreq->sr_cmd_len; | |
684 | cmd->use_sg = sreq->sr_use_sg; | |
685 | ||
686 | cmd->request = sreq->sr_request; | |
687 | memcpy(cmd->data_cmnd, sreq->sr_cmnd, sizeof(cmd->data_cmnd)); | |
688 | cmd->serial_number = 0; | |
689 | cmd->serial_number_at_timeout = 0; | |
690 | cmd->bufflen = sreq->sr_bufflen; | |
691 | cmd->buffer = sreq->sr_buffer; | |
692 | cmd->retries = 0; | |
693 | cmd->allowed = sreq->sr_allowed; | |
694 | cmd->done = sreq->sr_done; | |
695 | cmd->timeout_per_command = sreq->sr_timeout_per_command; | |
696 | cmd->sc_data_direction = sreq->sr_data_direction; | |
697 | cmd->sglist_len = sreq->sr_sglist_len; | |
698 | cmd->underflow = sreq->sr_underflow; | |
699 | cmd->sc_request = sreq; | |
700 | memcpy(cmd->cmnd, sreq->sr_cmnd, sizeof(sreq->sr_cmnd)); | |
701 | ||
702 | /* | |
703 | * Zero the sense buffer. Some host adapters automatically request | |
704 | * sense on error. 0 is not a valid sense code. | |
705 | */ | |
706 | memset(cmd->sense_buffer, 0, sizeof(sreq->sr_sense_buffer)); | |
707 | cmd->request_buffer = sreq->sr_buffer; | |
708 | cmd->request_bufflen = sreq->sr_bufflen; | |
709 | cmd->old_use_sg = cmd->use_sg; | |
710 | if (cmd->cmd_len == 0) | |
711 | cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); | |
712 | cmd->old_cmd_len = cmd->cmd_len; | |
713 | cmd->sc_old_data_direction = cmd->sc_data_direction; | |
714 | cmd->old_underflow = cmd->underflow; | |
715 | ||
716 | /* | |
717 | * Start the timer ticking. | |
718 | */ | |
719 | cmd->internal_timeout = NORMAL_TIMEOUT; | |
720 | cmd->abort_reason = 0; | |
721 | cmd->result = 0; | |
722 | ||
723 | SCSI_LOG_MLQUEUE(3, printk("Leaving scsi_init_cmd_from_req()\n")); | |
724 | } | |
725 | ||
726 | /* | |
727 | * Per-CPU I/O completion queue. | |
728 | */ | |
729 | static DEFINE_PER_CPU(struct list_head, scsi_done_q); | |
730 | ||
731 | /** | |
732 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
733 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
734 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
735 | * | |
736 | * This function is the mid-level's (SCSI Core) interrupt routine, which | |
737 | * regains ownership of the SCSI command (de facto) from a LLDD, and enqueues | |
738 | * the command to the done queue for further processing. | |
739 | * | |
740 | * This is the producer of the done queue who enqueues at the tail. | |
741 | * | |
742 | * This function is interrupt context safe. | |
743 | */ | |
744 | void scsi_done(struct scsi_cmnd *cmd) | |
745 | { | |
746 | /* | |
747 | * We don't have to worry about this one timing out any more. | |
748 | * If we are unable to remove the timer, then the command | |
749 | * has already timed out. In which case, we have no choice but to | |
750 | * let the timeout function run, as we have no idea where in fact | |
751 | * that function could really be. It might be on another processor, | |
752 | * etc, etc. | |
753 | */ | |
754 | if (!scsi_delete_timer(cmd)) | |
755 | return; | |
756 | __scsi_done(cmd); | |
757 | } | |
758 | ||
759 | /* Private entry to scsi_done() to complete a command when the timer | |
760 | * isn't running --- used by scsi_times_out */ | |
761 | void __scsi_done(struct scsi_cmnd *cmd) | |
762 | { | |
763 | unsigned long flags; | |
764 | ||
765 | /* | |
766 | * Set the serial numbers back to zero | |
767 | */ | |
768 | cmd->serial_number = 0; | |
769 | cmd->serial_number_at_timeout = 0; | |
770 | cmd->state = SCSI_STATE_BHQUEUE; | |
771 | cmd->owner = SCSI_OWNER_BH_HANDLER; | |
772 | ||
773 | atomic_inc(&cmd->device->iodone_cnt); | |
774 | if (cmd->result) | |
775 | atomic_inc(&cmd->device->ioerr_cnt); | |
776 | ||
777 | /* | |
778 | * Next, enqueue the command into the done queue. | |
779 | * It is a per-CPU queue, so we just disable local interrupts | |
780 | * and need no spinlock. | |
781 | */ | |
782 | local_irq_save(flags); | |
783 | list_add_tail(&cmd->eh_entry, &__get_cpu_var(scsi_done_q)); | |
784 | raise_softirq_irqoff(SCSI_SOFTIRQ); | |
785 | local_irq_restore(flags); | |
786 | } | |
787 | ||
788 | /** | |
789 | * scsi_softirq - Perform post-interrupt processing of finished SCSI commands. | |
790 | * | |
791 | * This is the consumer of the done queue. | |
792 | * | |
793 | * This is called with all interrupts enabled. This should reduce | |
794 | * interrupt latency, stack depth, and reentrancy of the low-level | |
795 | * drivers. | |
796 | */ | |
797 | static void scsi_softirq(struct softirq_action *h) | |
798 | { | |
799 | int disposition; | |
800 | LIST_HEAD(local_q); | |
801 | ||
802 | local_irq_disable(); | |
803 | list_splice_init(&__get_cpu_var(scsi_done_q), &local_q); | |
804 | local_irq_enable(); | |
805 | ||
806 | while (!list_empty(&local_q)) { | |
807 | struct scsi_cmnd *cmd = list_entry(local_q.next, | |
808 | struct scsi_cmnd, eh_entry); | |
809 | list_del_init(&cmd->eh_entry); | |
810 | ||
811 | disposition = scsi_decide_disposition(cmd); | |
812 | scsi_log_completion(cmd, disposition); | |
813 | switch (disposition) { | |
814 | case SUCCESS: | |
815 | scsi_finish_command(cmd); | |
816 | break; | |
817 | case NEEDS_RETRY: | |
818 | scsi_retry_command(cmd); | |
819 | break; | |
820 | case ADD_TO_MLQUEUE: | |
821 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
822 | break; | |
823 | default: | |
824 | if (!scsi_eh_scmd_add(cmd, 0)) | |
825 | scsi_finish_command(cmd); | |
826 | } | |
827 | } | |
828 | } | |
829 | ||
830 | /* | |
831 | * Function: scsi_retry_command | |
832 | * | |
833 | * Purpose: Send a command back to the low level to be retried. | |
834 | * | |
835 | * Notes: This command is always executed in the context of the | |
836 | * bottom half handler, or the error handler thread. Low | |
837 | * level drivers should not become re-entrant as a result of | |
838 | * this. | |
839 | */ | |
840 | int scsi_retry_command(struct scsi_cmnd *cmd) | |
841 | { | |
842 | /* | |
843 | * Restore the SCSI command state. | |
844 | */ | |
845 | scsi_setup_cmd_retry(cmd); | |
846 | ||
847 | /* | |
848 | * Zero the sense information from the last time we tried | |
849 | * this command. | |
850 | */ | |
851 | memset(cmd->sense_buffer, 0, sizeof(cmd->sense_buffer)); | |
852 | ||
853 | return scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); | |
854 | } | |
855 | ||
856 | /* | |
857 | * Function: scsi_finish_command | |
858 | * | |
859 | * Purpose: Pass command off to upper layer for finishing of I/O | |
860 | * request, waking processes that are waiting on results, | |
861 | * etc. | |
862 | */ | |
863 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
864 | { | |
865 | struct scsi_device *sdev = cmd->device; | |
866 | struct Scsi_Host *shost = sdev->host; | |
867 | struct scsi_request *sreq; | |
868 | ||
869 | scsi_device_unbusy(sdev); | |
870 | ||
871 | /* | |
872 | * Clear the flags which say that the device/host is no longer | |
873 | * capable of accepting new commands. These are set in scsi_queue.c | |
874 | * for both the queue full condition on a device, and for a | |
875 | * host full condition on the host. | |
876 | * | |
877 | * XXX(hch): What about locking? | |
878 | */ | |
879 | shost->host_blocked = 0; | |
880 | sdev->device_blocked = 0; | |
881 | ||
882 | /* | |
883 | * If we have valid sense information, then some kind of recovery | |
884 | * must have taken place. Make a note of this. | |
885 | */ | |
886 | if (SCSI_SENSE_VALID(cmd)) | |
887 | cmd->result |= (DRIVER_SENSE << 24); | |
888 | ||
889 | SCSI_LOG_MLCOMPLETE(4, printk("Notifying upper driver of completion " | |
890 | "for device %d %x\n", sdev->id, cmd->result)); | |
891 | ||
892 | cmd->owner = SCSI_OWNER_HIGHLEVEL; | |
893 | cmd->state = SCSI_STATE_FINISHED; | |
894 | ||
895 | /* | |
896 | * We can get here with use_sg=0, causing a panic in the upper level | |
897 | */ | |
898 | cmd->use_sg = cmd->old_use_sg; | |
899 | ||
900 | /* | |
901 | * If there is an associated request structure, copy the data over | |
902 | * before we call the completion function. | |
903 | */ | |
904 | sreq = cmd->sc_request; | |
905 | if (sreq) { | |
906 | sreq->sr_result = sreq->sr_command->result; | |
907 | if (sreq->sr_result) { | |
908 | memcpy(sreq->sr_sense_buffer, | |
909 | sreq->sr_command->sense_buffer, | |
910 | sizeof(sreq->sr_sense_buffer)); | |
911 | } | |
912 | } | |
913 | ||
914 | cmd->done(cmd); | |
915 | } | |
916 | EXPORT_SYMBOL(scsi_finish_command); | |
917 | ||
918 | /* | |
919 | * Function: scsi_adjust_queue_depth() | |
920 | * | |
921 | * Purpose: Allow low level drivers to tell us to change the queue depth | |
922 | * on a specific SCSI device | |
923 | * | |
924 | * Arguments: sdev - SCSI Device in question | |
925 | * tagged - Do we use tagged queueing (non-0) or do we treat | |
926 | * this device as an untagged device (0) | |
927 | * tags - Number of tags allowed if tagged queueing enabled, | |
928 | * or number of commands the low level driver can | |
929 | * queue up in non-tagged mode (as per cmd_per_lun). | |
930 | * | |
931 | * Returns: Nothing | |
932 | * | |
933 | * Lock Status: None held on entry | |
934 | * | |
935 | * Notes: Low level drivers may call this at any time and we will do | |
936 | * the right thing depending on whether or not the device is | |
937 | * currently active and whether or not it even has the | |
938 | * command blocks built yet. | |
939 | */ | |
940 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
941 | { | |
942 | unsigned long flags; | |
943 | ||
944 | /* | |
945 | * refuse to set tagged depth to an unworkable size | |
946 | */ | |
947 | if (tags <= 0) | |
948 | return; | |
949 | ||
950 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
951 | ||
952 | /* Check to see if the queue is managed by the block layer | |
953 | * if it is, and we fail to adjust the depth, exit */ | |
954 | if (blk_queue_tagged(sdev->request_queue) && | |
955 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
956 | goto out; | |
957 | ||
958 | sdev->queue_depth = tags; | |
959 | switch (tagged) { | |
960 | case MSG_ORDERED_TAG: | |
961 | sdev->ordered_tags = 1; | |
962 | sdev->simple_tags = 1; | |
963 | break; | |
964 | case MSG_SIMPLE_TAG: | |
965 | sdev->ordered_tags = 0; | |
966 | sdev->simple_tags = 1; | |
967 | break; | |
968 | default: | |
969 | printk(KERN_WARNING "(scsi%d:%d:%d:%d) " | |
970 | "scsi_adjust_queue_depth, bad queue type, " | |
971 | "disabled\n", sdev->host->host_no, | |
972 | sdev->channel, sdev->id, sdev->lun); | |
973 | case 0: | |
974 | sdev->ordered_tags = sdev->simple_tags = 0; | |
975 | sdev->queue_depth = tags; | |
976 | break; | |
977 | } | |
978 | out: | |
979 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
980 | } | |
981 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
982 | ||
983 | /* | |
984 | * Function: scsi_track_queue_full() | |
985 | * | |
986 | * Purpose: This function will track successive QUEUE_FULL events on a | |
987 | * specific SCSI device to determine if and when there is a | |
988 | * need to adjust the queue depth on the device. | |
989 | * | |
990 | * Arguments: sdev - SCSI Device in question | |
991 | * depth - Current number of outstanding SCSI commands on | |
992 | * this device, not counting the one returned as | |
993 | * QUEUE_FULL. | |
994 | * | |
995 | * Returns: 0 - No change needed | |
996 | * >0 - Adjust queue depth to this new depth | |
997 | * -1 - Drop back to untagged operation using host->cmd_per_lun | |
998 | * as the untagged command depth | |
999 | * | |
1000 | * Lock Status: None held on entry | |
1001 | * | |
1002 | * Notes: Low level drivers may call this at any time and we will do | |
1003 | * "The Right Thing." We are interrupt context safe. | |
1004 | */ | |
1005 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
1006 | { | |
1007 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
1008 | return 0; | |
1009 | ||
1010 | sdev->last_queue_full_time = (jiffies >> 4); | |
1011 | if (sdev->last_queue_full_depth != depth) { | |
1012 | sdev->last_queue_full_count = 1; | |
1013 | sdev->last_queue_full_depth = depth; | |
1014 | } else { | |
1015 | sdev->last_queue_full_count++; | |
1016 | } | |
1017 | ||
1018 | if (sdev->last_queue_full_count <= 10) | |
1019 | return 0; | |
1020 | if (sdev->last_queue_full_depth < 8) { | |
1021 | /* Drop back to untagged */ | |
1022 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
1023 | return -1; | |
1024 | } | |
1025 | ||
1026 | if (sdev->ordered_tags) | |
1027 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
1028 | else | |
1029 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
1030 | return depth; | |
1031 | } | |
1032 | EXPORT_SYMBOL(scsi_track_queue_full); | |
1033 | ||
1034 | /** | |
1035 | * scsi_device_get - get an addition reference to a scsi_device | |
1036 | * @sdev: device to get a reference to | |
1037 | * | |
1038 | * Gets a reference to the scsi_device and increments the use count | |
1039 | * of the underlying LLDD module. You must hold host_lock of the | |
1040 | * parent Scsi_Host or already have a reference when calling this. | |
1041 | */ | |
1042 | int scsi_device_get(struct scsi_device *sdev) | |
1043 | { | |
1044 | if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) | |
1045 | return -ENXIO; | |
1046 | if (!get_device(&sdev->sdev_gendev)) | |
1047 | return -ENXIO; | |
1048 | if (!try_module_get(sdev->host->hostt->module)) { | |
1049 | put_device(&sdev->sdev_gendev); | |
1050 | return -ENXIO; | |
1051 | } | |
1052 | return 0; | |
1053 | } | |
1054 | EXPORT_SYMBOL(scsi_device_get); | |
1055 | ||
1056 | /** | |
1057 | * scsi_device_put - release a reference to a scsi_device | |
1058 | * @sdev: device to release a reference on. | |
1059 | * | |
1060 | * Release a reference to the scsi_device and decrements the use count | |
1061 | * of the underlying LLDD module. The device is freed once the last | |
1062 | * user vanishes. | |
1063 | */ | |
1064 | void scsi_device_put(struct scsi_device *sdev) | |
1065 | { | |
1066 | module_put(sdev->host->hostt->module); | |
1067 | put_device(&sdev->sdev_gendev); | |
1068 | } | |
1069 | EXPORT_SYMBOL(scsi_device_put); | |
1070 | ||
1071 | /* helper for shost_for_each_device, thus not documented */ | |
1072 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, | |
1073 | struct scsi_device *prev) | |
1074 | { | |
1075 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
1076 | struct scsi_device *next = NULL; | |
1077 | unsigned long flags; | |
1078 | ||
1079 | spin_lock_irqsave(shost->host_lock, flags); | |
1080 | while (list->next != &shost->__devices) { | |
1081 | next = list_entry(list->next, struct scsi_device, siblings); | |
1082 | /* skip devices that we can't get a reference to */ | |
1083 | if (!scsi_device_get(next)) | |
1084 | break; | |
1085 | next = NULL; | |
1086 | list = list->next; | |
1087 | } | |
1088 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1089 | ||
1090 | if (prev) | |
1091 | scsi_device_put(prev); | |
1092 | return next; | |
1093 | } | |
1094 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
1095 | ||
1096 | /** | |
1097 | * starget_for_each_device - helper to walk all devices of a target | |
1098 | * @starget: target whose devices we want to iterate over. | |
1099 | * | |
1100 | * This traverses over each devices of @shost. The devices have | |
1101 | * a reference that must be released by scsi_host_put when breaking | |
1102 | * out of the loop. | |
1103 | */ | |
1104 | void starget_for_each_device(struct scsi_target *starget, void * data, | |
1105 | void (*fn)(struct scsi_device *, void *)) | |
1106 | { | |
1107 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1108 | struct scsi_device *sdev; | |
1109 | ||
1110 | shost_for_each_device(sdev, shost) { | |
1111 | if ((sdev->channel == starget->channel) && | |
1112 | (sdev->id == starget->id)) | |
1113 | fn(sdev, data); | |
1114 | } | |
1115 | } | |
1116 | EXPORT_SYMBOL(starget_for_each_device); | |
1117 | ||
1118 | /** | |
1119 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
1120 | * @starget: SCSI target pointer | |
1121 | * @lun: SCSI Logical Unit Number | |
1122 | * | |
1123 | * Looks up the scsi_device with the specified @lun for a give | |
1124 | * @starget. The returned scsi_device does not have an additional | |
1125 | * reference. You must hold the host's host_lock over this call and | |
1126 | * any access to the returned scsi_device. | |
1127 | * | |
1128 | * Note: The only reason why drivers would want to use this is because | |
1129 | * they're need to access the device list in irq context. Otherwise you | |
1130 | * really want to use scsi_device_lookup_by_target instead. | |
1131 | **/ | |
1132 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
1133 | uint lun) | |
1134 | { | |
1135 | struct scsi_device *sdev; | |
1136 | ||
1137 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
1138 | if (sdev->lun ==lun) | |
1139 | return sdev; | |
1140 | } | |
1141 | ||
1142 | return NULL; | |
1143 | } | |
1144 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
1145 | ||
1146 | /** | |
1147 | * scsi_device_lookup_by_target - find a device given the target | |
1148 | * @starget: SCSI target pointer | |
1149 | * @lun: SCSI Logical Unit Number | |
1150 | * | |
1151 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
1152 | * give host. The returned scsi_device has an additional reference that | |
1153 | * needs to be release with scsi_host_put once you're done with it. | |
1154 | **/ | |
1155 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
1156 | uint lun) | |
1157 | { | |
1158 | struct scsi_device *sdev; | |
1159 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1160 | unsigned long flags; | |
1161 | ||
1162 | spin_lock_irqsave(shost->host_lock, flags); | |
1163 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
1164 | if (sdev && scsi_device_get(sdev)) | |
1165 | sdev = NULL; | |
1166 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1167 | ||
1168 | return sdev; | |
1169 | } | |
1170 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1171 | ||
1172 | /** | |
1173 | * scsi_device_lookup - find a device given the host (UNLOCKED) | |
1174 | * @shost: SCSI host pointer | |
1175 | * @channel: SCSI channel (zero if only one channel) | |
1176 | * @pun: SCSI target number (physical unit number) | |
1177 | * @lun: SCSI Logical Unit Number | |
1178 | * | |
1179 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
1180 | * give host. The returned scsi_device does not have an additional reference. | |
1181 | * You must hold the host's host_lock over this call and any access to the | |
1182 | * returned scsi_device. | |
1183 | * | |
1184 | * Note: The only reason why drivers would want to use this is because | |
1185 | * they're need to access the device list in irq context. Otherwise you | |
1186 | * really want to use scsi_device_lookup instead. | |
1187 | **/ | |
1188 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1189 | uint channel, uint id, uint lun) | |
1190 | { | |
1191 | struct scsi_device *sdev; | |
1192 | ||
1193 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1194 | if (sdev->channel == channel && sdev->id == id && | |
1195 | sdev->lun ==lun) | |
1196 | return sdev; | |
1197 | } | |
1198 | ||
1199 | return NULL; | |
1200 | } | |
1201 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1202 | ||
1203 | /** | |
1204 | * scsi_device_lookup - find a device given the host | |
1205 | * @shost: SCSI host pointer | |
1206 | * @channel: SCSI channel (zero if only one channel) | |
1207 | * @id: SCSI target number (physical unit number) | |
1208 | * @lun: SCSI Logical Unit Number | |
1209 | * | |
1210 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
1211 | * give host. The returned scsi_device has an additional reference that | |
1212 | * needs to be release with scsi_host_put once you're done with it. | |
1213 | **/ | |
1214 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1215 | uint channel, uint id, uint lun) | |
1216 | { | |
1217 | struct scsi_device *sdev; | |
1218 | unsigned long flags; | |
1219 | ||
1220 | spin_lock_irqsave(shost->host_lock, flags); | |
1221 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1222 | if (sdev && scsi_device_get(sdev)) | |
1223 | sdev = NULL; | |
1224 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1225 | ||
1226 | return sdev; | |
1227 | } | |
1228 | EXPORT_SYMBOL(scsi_device_lookup); | |
1229 | ||
1230 | /** | |
1231 | * scsi_device_cancel - cancel outstanding IO to this device | |
1232 | * @sdev: Pointer to struct scsi_device | |
1233 | * @recovery: Boolean instructing function to recover device or not. | |
1234 | * | |
1235 | **/ | |
1236 | int scsi_device_cancel(struct scsi_device *sdev, int recovery) | |
1237 | { | |
1238 | struct scsi_cmnd *scmd; | |
1239 | LIST_HEAD(active_list); | |
1240 | struct list_head *lh, *lh_sf; | |
1241 | unsigned long flags; | |
1242 | ||
1243 | scsi_device_set_state(sdev, SDEV_CANCEL); | |
1244 | ||
1245 | spin_lock_irqsave(&sdev->list_lock, flags); | |
1246 | list_for_each_entry(scmd, &sdev->cmd_list, list) { | |
1247 | if (scmd->request && scmd->request->rq_status != RQ_INACTIVE) { | |
1248 | /* | |
1249 | * If we are unable to remove the timer, it means | |
1250 | * that the command has already timed out or | |
1251 | * finished. | |
1252 | */ | |
1253 | if (!scsi_delete_timer(scmd)) | |
1254 | continue; | |
1255 | list_add_tail(&scmd->eh_entry, &active_list); | |
1256 | } | |
1257 | } | |
1258 | spin_unlock_irqrestore(&sdev->list_lock, flags); | |
1259 | ||
1260 | if (!list_empty(&active_list)) { | |
1261 | list_for_each_safe(lh, lh_sf, &active_list) { | |
1262 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | |
1263 | list_del_init(lh); | |
1264 | if (recovery) { | |
1265 | scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD); | |
1266 | } else { | |
1267 | scmd->result = (DID_ABORT << 16); | |
1268 | scsi_finish_command(scmd); | |
1269 | } | |
1270 | } | |
1271 | } | |
1272 | ||
1273 | return 0; | |
1274 | } | |
1275 | EXPORT_SYMBOL(scsi_device_cancel); | |
1276 | ||
1277 | #ifdef CONFIG_HOTPLUG_CPU | |
1278 | static int scsi_cpu_notify(struct notifier_block *self, | |
1279 | unsigned long action, void *hcpu) | |
1280 | { | |
1281 | int cpu = (unsigned long)hcpu; | |
1282 | ||
1283 | switch(action) { | |
1284 | case CPU_DEAD: | |
1285 | /* Drain scsi_done_q. */ | |
1286 | local_irq_disable(); | |
1287 | list_splice_init(&per_cpu(scsi_done_q, cpu), | |
1288 | &__get_cpu_var(scsi_done_q)); | |
1289 | raise_softirq_irqoff(SCSI_SOFTIRQ); | |
1290 | local_irq_enable(); | |
1291 | break; | |
1292 | default: | |
1293 | break; | |
1294 | } | |
1295 | return NOTIFY_OK; | |
1296 | } | |
1297 | ||
1298 | static struct notifier_block __devinitdata scsi_cpu_nb = { | |
1299 | .notifier_call = scsi_cpu_notify, | |
1300 | }; | |
1301 | ||
1302 | #define register_scsi_cpu() register_cpu_notifier(&scsi_cpu_nb) | |
1303 | #define unregister_scsi_cpu() unregister_cpu_notifier(&scsi_cpu_nb) | |
1304 | #else | |
1305 | #define register_scsi_cpu() | |
1306 | #define unregister_scsi_cpu() | |
1307 | #endif /* CONFIG_HOTPLUG_CPU */ | |
1308 | ||
1309 | MODULE_DESCRIPTION("SCSI core"); | |
1310 | MODULE_LICENSE("GPL"); | |
1311 | ||
1312 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1313 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1314 | ||
1315 | static int __init init_scsi(void) | |
1316 | { | |
1317 | int error, i; | |
1318 | ||
1319 | error = scsi_init_queue(); | |
1320 | if (error) | |
1321 | return error; | |
1322 | error = scsi_init_procfs(); | |
1323 | if (error) | |
1324 | goto cleanup_queue; | |
1325 | error = scsi_init_devinfo(); | |
1326 | if (error) | |
1327 | goto cleanup_procfs; | |
1328 | error = scsi_init_hosts(); | |
1329 | if (error) | |
1330 | goto cleanup_devlist; | |
1331 | error = scsi_init_sysctl(); | |
1332 | if (error) | |
1333 | goto cleanup_hosts; | |
1334 | error = scsi_sysfs_register(); | |
1335 | if (error) | |
1336 | goto cleanup_sysctl; | |
1337 | ||
1338 | for (i = 0; i < NR_CPUS; i++) | |
1339 | INIT_LIST_HEAD(&per_cpu(scsi_done_q, i)); | |
1340 | ||
1341 | devfs_mk_dir("scsi"); | |
1342 | open_softirq(SCSI_SOFTIRQ, scsi_softirq, NULL); | |
1343 | register_scsi_cpu(); | |
1344 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); | |
1345 | return 0; | |
1346 | ||
1347 | cleanup_sysctl: | |
1348 | scsi_exit_sysctl(); | |
1349 | cleanup_hosts: | |
1350 | scsi_exit_hosts(); | |
1351 | cleanup_devlist: | |
1352 | scsi_exit_devinfo(); | |
1353 | cleanup_procfs: | |
1354 | scsi_exit_procfs(); | |
1355 | cleanup_queue: | |
1356 | scsi_exit_queue(); | |
1357 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1358 | -error); | |
1359 | return error; | |
1360 | } | |
1361 | ||
1362 | static void __exit exit_scsi(void) | |
1363 | { | |
1364 | scsi_sysfs_unregister(); | |
1365 | scsi_exit_sysctl(); | |
1366 | scsi_exit_hosts(); | |
1367 | scsi_exit_devinfo(); | |
1368 | devfs_remove("scsi"); | |
1369 | scsi_exit_procfs(); | |
1370 | scsi_exit_queue(); | |
1371 | unregister_scsi_cpu(); | |
1372 | } | |
1373 | ||
1374 | subsys_initcall(init_scsi); | |
1375 | module_exit(exit_scsi); |