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1da177e4 LT |
1 | /* |
2 | * scsi.c Copyright (C) 1992 Drew Eckhardt | |
3 | * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale | |
4 | * Copyright (C) 2002, 2003 Christoph Hellwig | |
5 | * | |
6 | * generic mid-level SCSI driver | |
7 | * Initial versions: Drew Eckhardt | |
8 | * Subsequent revisions: Eric Youngdale | |
9 | * | |
10 | * <drew@colorado.edu> | |
11 | * | |
12 | * Bug correction thanks go to : | |
13 | * Rik Faith <faith@cs.unc.edu> | |
14 | * Tommy Thorn <tthorn> | |
15 | * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de> | |
16 | * | |
17 | * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to | |
18 | * add scatter-gather, multiple outstanding request, and other | |
19 | * enhancements. | |
20 | * | |
21 | * Native multichannel, wide scsi, /proc/scsi and hot plugging | |
22 | * support added by Michael Neuffer <mike@i-connect.net> | |
23 | * | |
24 | * Added request_module("scsi_hostadapter") for kerneld: | |
25 | * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) | |
26 | * Bjorn Ekwall <bj0rn@blox.se> | |
27 | * (changed to kmod) | |
28 | * | |
29 | * Major improvements to the timeout, abort, and reset processing, | |
30 | * as well as performance modifications for large queue depths by | |
31 | * Leonard N. Zubkoff <lnz@dandelion.com> | |
32 | * | |
33 | * Converted cli() code to spinlocks, Ingo Molnar | |
34 | * | |
35 | * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli | |
36 | * | |
37 | * out_of_space hacks, D. Gilbert (dpg) 990608 | |
38 | */ | |
39 | ||
40 | #include <linux/module.h> | |
41 | #include <linux/moduleparam.h> | |
42 | #include <linux/kernel.h> | |
1da177e4 LT |
43 | #include <linux/timer.h> |
44 | #include <linux/string.h> | |
45 | #include <linux/slab.h> | |
46 | #include <linux/blkdev.h> | |
47 | #include <linux/delay.h> | |
48 | #include <linux/init.h> | |
49 | #include <linux/completion.h> | |
1da177e4 LT |
50 | #include <linux/unistd.h> |
51 | #include <linux/spinlock.h> | |
52 | #include <linux/kmod.h> | |
53 | #include <linux/interrupt.h> | |
54 | #include <linux/notifier.h> | |
55 | #include <linux/cpu.h> | |
0b950672 | 56 | #include <linux/mutex.h> |
1da177e4 LT |
57 | |
58 | #include <scsi/scsi.h> | |
59 | #include <scsi/scsi_cmnd.h> | |
60 | #include <scsi/scsi_dbg.h> | |
61 | #include <scsi/scsi_device.h> | |
7b3d9545 | 62 | #include <scsi/scsi_driver.h> |
1da177e4 LT |
63 | #include <scsi/scsi_eh.h> |
64 | #include <scsi/scsi_host.h> | |
65 | #include <scsi/scsi_tcq.h> | |
1da177e4 LT |
66 | |
67 | #include "scsi_priv.h" | |
68 | #include "scsi_logging.h" | |
69 | ||
52c1da39 | 70 | static void scsi_done(struct scsi_cmnd *cmd); |
1da177e4 LT |
71 | |
72 | /* | |
73 | * Definitions and constants. | |
74 | */ | |
75 | ||
76 | #define MIN_RESET_DELAY (2*HZ) | |
77 | ||
78 | /* Do not call reset on error if we just did a reset within 15 sec. */ | |
79 | #define MIN_RESET_PERIOD (15*HZ) | |
80 | ||
1da177e4 LT |
81 | /* |
82 | * Note - the initial logging level can be set here to log events at boot time. | |
83 | * After the system is up, you may enable logging via the /proc interface. | |
84 | */ | |
85 | unsigned int scsi_logging_level; | |
86 | #if defined(CONFIG_SCSI_LOGGING) | |
87 | EXPORT_SYMBOL(scsi_logging_level); | |
88 | #endif | |
89 | ||
8a1cdc9c MW |
90 | /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. |
91 | * You may not alter any existing entry (although adding new ones is | |
92 | * encouraged once assigned by ANSI/INCITS T10 | |
93 | */ | |
4ff36718 | 94 | static const char *const scsi_device_types[] = { |
8a1cdc9c MW |
95 | "Direct-Access ", |
96 | "Sequential-Access", | |
1da177e4 LT |
97 | "Printer ", |
98 | "Processor ", | |
99 | "WORM ", | |
8a1cdc9c | 100 | "CD-ROM ", |
1da177e4 | 101 | "Scanner ", |
8a1cdc9c MW |
102 | "Optical Device ", |
103 | "Medium Changer ", | |
1da177e4 | 104 | "Communications ", |
4ff36718 MW |
105 | "ASC IT8 ", |
106 | "ASC IT8 ", | |
1da177e4 LT |
107 | "RAID ", |
108 | "Enclosure ", | |
8a1cdc9c | 109 | "Direct-Access-RBC", |
4ff36718 MW |
110 | "Optical card ", |
111 | "Bridge controller", | |
112 | "Object storage ", | |
113 | "Automation/Drive ", | |
1da177e4 | 114 | }; |
4ff36718 | 115 | |
eb44820c RL |
116 | /** |
117 | * scsi_device_type - Return 17 char string indicating device type. | |
118 | * @type: type number to look up | |
119 | */ | |
120 | ||
4ff36718 MW |
121 | const char * scsi_device_type(unsigned type) |
122 | { | |
123 | if (type == 0x1e) | |
124 | return "Well-known LUN "; | |
125 | if (type == 0x1f) | |
126 | return "No Device "; | |
80c6e3c0 | 127 | if (type >= ARRAY_SIZE(scsi_device_types)) |
4ff36718 MW |
128 | return "Unknown "; |
129 | return scsi_device_types[type]; | |
130 | } | |
131 | ||
132 | EXPORT_SYMBOL(scsi_device_type); | |
1da177e4 | 133 | |
1da177e4 | 134 | struct scsi_host_cmd_pool { |
5b7f1680 JB |
135 | struct kmem_cache *cmd_slab; |
136 | struct kmem_cache *sense_slab; | |
137 | unsigned int users; | |
138 | char *cmd_name; | |
139 | char *sense_name; | |
140 | unsigned int slab_flags; | |
141 | gfp_t gfp_mask; | |
1da177e4 LT |
142 | }; |
143 | ||
144 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
5b7f1680 JB |
145 | .cmd_name = "scsi_cmd_cache", |
146 | .sense_name = "scsi_sense_cache", | |
1da177e4 LT |
147 | .slab_flags = SLAB_HWCACHE_ALIGN, |
148 | }; | |
149 | ||
150 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
5b7f1680 JB |
151 | .cmd_name = "scsi_cmd_cache(DMA)", |
152 | .sense_name = "scsi_sense_cache(DMA)", | |
1da177e4 LT |
153 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, |
154 | .gfp_mask = __GFP_DMA, | |
155 | }; | |
156 | ||
0b950672 | 157 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 158 | |
e507e30b JB |
159 | /** |
160 | * scsi_pool_alloc_command - internal function to get a fully allocated command | |
161 | * @pool: slab pool to allocate the command from | |
162 | * @gfp_mask: mask for the allocation | |
163 | * | |
164 | * Returns a fully allocated command (with the allied sense buffer) or | |
165 | * NULL on failure | |
166 | */ | |
167 | static struct scsi_cmnd * | |
168 | scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask) | |
169 | { | |
170 | struct scsi_cmnd *cmd; | |
171 | ||
172 | cmd = kmem_cache_alloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); | |
173 | if (!cmd) | |
174 | return NULL; | |
175 | ||
176 | memset(cmd, 0, sizeof(*cmd)); | |
177 | ||
178 | cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, | |
179 | gfp_mask | pool->gfp_mask); | |
180 | if (!cmd->sense_buffer) { | |
181 | kmem_cache_free(pool->cmd_slab, cmd); | |
182 | return NULL; | |
183 | } | |
184 | ||
185 | return cmd; | |
186 | } | |
187 | ||
188 | /** | |
189 | * scsi_pool_free_command - internal function to release a command | |
190 | * @pool: slab pool to allocate the command from | |
191 | * @cmd: command to release | |
192 | * | |
193 | * the command must previously have been allocated by | |
194 | * scsi_pool_alloc_command. | |
195 | */ | |
196 | static void | |
197 | scsi_pool_free_command(struct scsi_host_cmd_pool *pool, | |
198 | struct scsi_cmnd *cmd) | |
199 | { | |
7027ad72 MP |
200 | if (cmd->prot_sdb) |
201 | kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); | |
202 | ||
e507e30b JB |
203 | kmem_cache_free(pool->sense_slab, cmd->sense_buffer); |
204 | kmem_cache_free(pool->cmd_slab, cmd); | |
205 | } | |
206 | ||
7027ad72 MP |
207 | /** |
208 | * scsi_host_alloc_command - internal function to allocate command | |
209 | * @shost: SCSI host whose pool to allocate from | |
210 | * @gfp_mask: mask for the allocation | |
211 | * | |
212 | * Returns a fully allocated command with sense buffer and protection | |
213 | * data buffer (where applicable) or NULL on failure | |
214 | */ | |
215 | static struct scsi_cmnd * | |
216 | scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) | |
217 | { | |
218 | struct scsi_cmnd *cmd; | |
219 | ||
220 | cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask); | |
221 | if (!cmd) | |
222 | return NULL; | |
223 | ||
224 | if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { | |
225 | cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); | |
226 | ||
227 | if (!cmd->prot_sdb) { | |
228 | scsi_pool_free_command(shost->cmd_pool, cmd); | |
229 | return NULL; | |
230 | } | |
231 | } | |
232 | ||
233 | return cmd; | |
234 | } | |
235 | ||
eb44820c RL |
236 | /** |
237 | * __scsi_get_command - Allocate a struct scsi_cmnd | |
238 | * @shost: host to transmit command | |
239 | * @gfp_mask: allocation mask | |
240 | * | |
241 | * Description: allocate a struct scsi_cmd from host's slab, recycling from the | |
242 | * host's free_list if necessary. | |
243 | */ | |
b58d9154 | 244 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 LT |
245 | { |
246 | struct scsi_cmnd *cmd; | |
de25deb1 | 247 | unsigned char *buf; |
1da177e4 | 248 | |
7027ad72 | 249 | cmd = scsi_host_alloc_command(shost, gfp_mask); |
164fc5dc | 250 | |
1da177e4 LT |
251 | if (unlikely(!cmd)) { |
252 | unsigned long flags; | |
253 | ||
254 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
255 | if (likely(!list_empty(&shost->free_list))) { | |
256 | cmd = list_entry(shost->free_list.next, | |
257 | struct scsi_cmnd, list); | |
258 | list_del_init(&cmd->list); | |
259 | } | |
260 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
de25deb1 FT |
261 | |
262 | if (cmd) { | |
263 | buf = cmd->sense_buffer; | |
264 | memset(cmd, 0, sizeof(*cmd)); | |
265 | cmd->sense_buffer = buf; | |
266 | } | |
1da177e4 LT |
267 | } |
268 | ||
269 | return cmd; | |
270 | } | |
b58d9154 | 271 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 | 272 | |
eb44820c RL |
273 | /** |
274 | * scsi_get_command - Allocate and setup a scsi command block | |
275 | * @dev: parent scsi device | |
276 | * @gfp_mask: allocator flags | |
1da177e4 LT |
277 | * |
278 | * Returns: The allocated scsi command structure. | |
279 | */ | |
c53033f6 | 280 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
281 | { |
282 | struct scsi_cmnd *cmd; | |
283 | ||
284 | /* Bail if we can't get a reference to the device */ | |
285 | if (!get_device(&dev->sdev_gendev)) | |
286 | return NULL; | |
287 | ||
288 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
289 | ||
290 | if (likely(cmd != NULL)) { | |
291 | unsigned long flags; | |
292 | ||
1da177e4 | 293 | cmd->device = dev; |
1da177e4 LT |
294 | INIT_LIST_HEAD(&cmd->list); |
295 | spin_lock_irqsave(&dev->list_lock, flags); | |
296 | list_add_tail(&cmd->list, &dev->cmd_list); | |
297 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 298 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
299 | } else |
300 | put_device(&dev->sdev_gendev); | |
301 | ||
302 | return cmd; | |
b58d9154 | 303 | } |
1da177e4 LT |
304 | EXPORT_SYMBOL(scsi_get_command); |
305 | ||
eb44820c RL |
306 | /** |
307 | * __scsi_put_command - Free a struct scsi_cmnd | |
308 | * @shost: dev->host | |
309 | * @cmd: Command to free | |
310 | * @dev: parent scsi device | |
311 | */ | |
b58d9154 FT |
312 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
313 | struct device *dev) | |
314 | { | |
315 | unsigned long flags; | |
316 | ||
317 | /* changing locks here, don't need to restore the irq state */ | |
318 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
319 | if (unlikely(list_empty(&shost->free_list))) { | |
320 | list_add(&cmd->list, &shost->free_list); | |
321 | cmd = NULL; | |
322 | } | |
323 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
324 | ||
e507e30b JB |
325 | if (likely(cmd != NULL)) |
326 | scsi_pool_free_command(shost->cmd_pool, cmd); | |
b58d9154 FT |
327 | |
328 | put_device(dev); | |
329 | } | |
330 | EXPORT_SYMBOL(__scsi_put_command); | |
331 | ||
eb44820c RL |
332 | /** |
333 | * scsi_put_command - Free a scsi command block | |
334 | * @cmd: command block to free | |
1da177e4 LT |
335 | * |
336 | * Returns: Nothing. | |
337 | * | |
338 | * Notes: The command must not belong to any lists. | |
339 | */ | |
340 | void scsi_put_command(struct scsi_cmnd *cmd) | |
341 | { | |
342 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 343 | unsigned long flags; |
b58d9154 | 344 | |
1da177e4 LT |
345 | /* serious error if the command hasn't come from a device list */ |
346 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
347 | BUG_ON(list_empty(&cmd->list)); | |
348 | list_del_init(&cmd->list); | |
b58d9154 | 349 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 350 | |
b58d9154 | 351 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
352 | } |
353 | EXPORT_SYMBOL(scsi_put_command); | |
354 | ||
1c353f7d | 355 | static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask) |
1da177e4 | 356 | { |
1c353f7d | 357 | struct scsi_host_cmd_pool *retval = NULL, *pool; |
1da177e4 LT |
358 | /* |
359 | * Select a command slab for this host and create it if not | |
eb44820c | 360 | * yet existent. |
1da177e4 | 361 | */ |
0b950672 | 362 | mutex_lock(&host_cmd_pool_mutex); |
1c353f7d JB |
363 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
364 | &scsi_cmd_pool; | |
1da177e4 | 365 | if (!pool->users) { |
5b7f1680 JB |
366 | pool->cmd_slab = kmem_cache_create(pool->cmd_name, |
367 | sizeof(struct scsi_cmnd), 0, | |
368 | pool->slab_flags, NULL); | |
369 | if (!pool->cmd_slab) | |
370 | goto fail; | |
371 | ||
372 | pool->sense_slab = kmem_cache_create(pool->sense_name, | |
373 | SCSI_SENSE_BUFFERSIZE, 0, | |
374 | pool->slab_flags, NULL); | |
375 | if (!pool->sense_slab) { | |
376 | kmem_cache_destroy(pool->cmd_slab); | |
1da177e4 | 377 | goto fail; |
5b7f1680 | 378 | } |
1da177e4 LT |
379 | } |
380 | ||
381 | pool->users++; | |
1c353f7d JB |
382 | retval = pool; |
383 | fail: | |
0b950672 | 384 | mutex_unlock(&host_cmd_pool_mutex); |
1c353f7d JB |
385 | return retval; |
386 | } | |
387 | ||
388 | static void scsi_put_host_cmd_pool(gfp_t gfp_mask) | |
389 | { | |
390 | struct scsi_host_cmd_pool *pool; | |
1da177e4 | 391 | |
1c353f7d JB |
392 | mutex_lock(&host_cmd_pool_mutex); |
393 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : | |
394 | &scsi_cmd_pool; | |
1da177e4 | 395 | /* |
1c353f7d JB |
396 | * This may happen if a driver has a mismatched get and put |
397 | * of the command pool; the driver should be implicated in | |
398 | * the stack trace | |
1da177e4 | 399 | */ |
1c353f7d | 400 | BUG_ON(pool->users == 0); |
de25deb1 | 401 | |
5b7f1680 JB |
402 | if (!--pool->users) { |
403 | kmem_cache_destroy(pool->cmd_slab); | |
404 | kmem_cache_destroy(pool->sense_slab); | |
405 | } | |
0b950672 | 406 | mutex_unlock(&host_cmd_pool_mutex); |
1c353f7d JB |
407 | } |
408 | ||
409 | /** | |
410 | * scsi_allocate_command - get a fully allocated SCSI command | |
411 | * @gfp_mask: allocation mask | |
412 | * | |
413 | * This function is for use outside of the normal host based pools. | |
414 | * It allocates the relevant command and takes an additional reference | |
415 | * on the pool it used. This function *must* be paired with | |
416 | * scsi_free_command which also has the identical mask, otherwise the | |
417 | * free pool counts will eventually go wrong and you'll trigger a bug. | |
418 | * | |
419 | * This function should *only* be used by drivers that need a static | |
420 | * command allocation at start of day for internal functions. | |
421 | */ | |
422 | struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask) | |
423 | { | |
424 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); | |
425 | ||
426 | if (!pool) | |
427 | return NULL; | |
428 | ||
429 | return scsi_pool_alloc_command(pool, gfp_mask); | |
430 | } | |
431 | EXPORT_SYMBOL(scsi_allocate_command); | |
432 | ||
433 | /** | |
434 | * scsi_free_command - free a command allocated by scsi_allocate_command | |
435 | * @gfp_mask: mask used in the original allocation | |
436 | * @cmd: command to free | |
437 | * | |
438 | * Note: using the original allocation mask is vital because that's | |
439 | * what determines which command pool we use to free the command. Any | |
440 | * mismatch will cause the system to BUG eventually. | |
441 | */ | |
442 | void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd) | |
443 | { | |
444 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); | |
445 | ||
446 | /* | |
447 | * this could trigger if the mask to scsi_allocate_command | |
448 | * doesn't match this mask. Otherwise we're guaranteed that this | |
449 | * succeeds because scsi_allocate_command must have taken a reference | |
450 | * on the pool | |
451 | */ | |
452 | BUG_ON(!pool); | |
453 | ||
454 | scsi_pool_free_command(pool, cmd); | |
455 | /* | |
456 | * scsi_put_host_cmd_pool is called twice; once to release the | |
457 | * reference we took above, and once to release the reference | |
458 | * originally taken by scsi_allocate_command | |
459 | */ | |
460 | scsi_put_host_cmd_pool(gfp_mask); | |
461 | scsi_put_host_cmd_pool(gfp_mask); | |
462 | } | |
463 | EXPORT_SYMBOL(scsi_free_command); | |
464 | ||
465 | /** | |
466 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. | |
467 | * @shost: host to allocate the freelist for. | |
468 | * | |
469 | * Description: The command freelist protects against system-wide out of memory | |
470 | * deadlock by preallocating one SCSI command structure for each host, so the | |
471 | * system can always write to a swap file on a device associated with that host. | |
472 | * | |
473 | * Returns: Nothing. | |
474 | */ | |
475 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
476 | { | |
477 | struct scsi_cmnd *cmd; | |
478 | const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; | |
479 | ||
480 | spin_lock_init(&shost->free_list_lock); | |
481 | INIT_LIST_HEAD(&shost->free_list); | |
482 | ||
483 | shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask); | |
484 | ||
485 | if (!shost->cmd_pool) | |
486 | return -ENOMEM; | |
487 | ||
488 | /* | |
489 | * Get one backup command for this host. | |
490 | */ | |
7027ad72 | 491 | cmd = scsi_host_alloc_command(shost, gfp_mask); |
1c353f7d JB |
492 | if (!cmd) { |
493 | scsi_put_host_cmd_pool(gfp_mask); | |
61d7416a | 494 | shost->cmd_pool = NULL; |
1c353f7d JB |
495 | return -ENOMEM; |
496 | } | |
497 | list_add(&cmd->list, &shost->free_list); | |
498 | return 0; | |
1da177e4 LT |
499 | } |
500 | ||
eb44820c RL |
501 | /** |
502 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. | |
503 | * @shost: host whose freelist is going to be destroyed | |
1da177e4 LT |
504 | */ |
505 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
506 | { | |
61d7416a AB |
507 | /* |
508 | * If cmd_pool is NULL the free list was not initialized, so | |
509 | * do not attempt to release resources. | |
510 | */ | |
511 | if (!shost->cmd_pool) | |
512 | return; | |
513 | ||
1da177e4 LT |
514 | while (!list_empty(&shost->free_list)) { |
515 | struct scsi_cmnd *cmd; | |
516 | ||
517 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
518 | list_del_init(&cmd->list); | |
e507e30b | 519 | scsi_pool_free_command(shost->cmd_pool, cmd); |
1da177e4 | 520 | } |
1c353f7d JB |
521 | shost->cmd_pool = NULL; |
522 | scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL); | |
de25deb1 FT |
523 | } |
524 | ||
1da177e4 LT |
525 | #ifdef CONFIG_SCSI_LOGGING |
526 | void scsi_log_send(struct scsi_cmnd *cmd) | |
527 | { | |
528 | unsigned int level; | |
1da177e4 LT |
529 | |
530 | /* | |
531 | * If ML QUEUE log level is greater than or equal to: | |
532 | * | |
533 | * 1: nothing (match completion) | |
534 | * | |
535 | * 2: log opcode + command of all commands | |
536 | * | |
537 | * 3: same as 2 plus dump cmd address | |
538 | * | |
539 | * 4: same as 3 plus dump extra junk | |
540 | */ | |
541 | if (unlikely(scsi_logging_level)) { | |
542 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
543 | SCSI_LOG_MLQUEUE_BITS); | |
544 | if (level > 1) { | |
a4d04a4c | 545 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
546 | if (level > 2) |
547 | printk("0x%p ", cmd); | |
a4d04a4c | 548 | printk("\n"); |
1da177e4 LT |
549 | scsi_print_command(cmd); |
550 | if (level > 3) { | |
551 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
7b3d9545 | 552 | " queuecommand 0x%p\n", |
a73e45b3 | 553 | scsi_sglist(cmd), scsi_bufflen(cmd), |
a4d04a4c | 554 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
555 | |
556 | } | |
557 | } | |
558 | } | |
559 | } | |
560 | ||
561 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
562 | { | |
563 | unsigned int level; | |
1da177e4 LT |
564 | |
565 | /* | |
566 | * If ML COMPLETE log level is greater than or equal to: | |
567 | * | |
568 | * 1: log disposition, result, opcode + command, and conditionally | |
569 | * sense data for failures or non SUCCESS dispositions. | |
570 | * | |
571 | * 2: same as 1 but for all command completions. | |
572 | * | |
573 | * 3: same as 2 plus dump cmd address | |
574 | * | |
575 | * 4: same as 3 plus dump extra junk | |
576 | */ | |
577 | if (unlikely(scsi_logging_level)) { | |
578 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
579 | SCSI_LOG_MLCOMPLETE_BITS); | |
580 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
581 | (level > 1)) { | |
a4d04a4c | 582 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
583 | if (level > 2) |
584 | printk("0x%p ", cmd); | |
585 | /* | |
586 | * Dump truncated values, so we usually fit within | |
587 | * 80 chars. | |
588 | */ | |
589 | switch (disposition) { | |
590 | case SUCCESS: | |
a4d04a4c | 591 | printk("SUCCESS\n"); |
1da177e4 LT |
592 | break; |
593 | case NEEDS_RETRY: | |
a4d04a4c | 594 | printk("RETRY\n"); |
1da177e4 LT |
595 | break; |
596 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 597 | printk("MLQUEUE\n"); |
1da177e4 LT |
598 | break; |
599 | case FAILED: | |
a4d04a4c | 600 | printk("FAILED\n"); |
1da177e4 LT |
601 | break; |
602 | case TIMEOUT_ERROR: | |
603 | /* | |
604 | * If called via scsi_times_out. | |
605 | */ | |
a4d04a4c | 606 | printk("TIMEOUT\n"); |
1da177e4 LT |
607 | break; |
608 | default: | |
a4d04a4c | 609 | printk("UNKNOWN\n"); |
1da177e4 | 610 | } |
a4d04a4c | 611 | scsi_print_result(cmd); |
1da177e4 | 612 | scsi_print_command(cmd); |
a4d04a4c | 613 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 614 | scsi_print_sense("", cmd); |
a4d04a4c MP |
615 | if (level > 3) |
616 | scmd_printk(KERN_INFO, cmd, | |
617 | "scsi host busy %d failed %d\n", | |
618 | cmd->device->host->host_busy, | |
619 | cmd->device->host->host_failed); | |
1da177e4 LT |
620 | } |
621 | } | |
622 | } | |
623 | #endif | |
624 | ||
eb44820c RL |
625 | /** |
626 | * scsi_cmd_get_serial - Assign a serial number to a command | |
627 | * @host: the scsi host | |
628 | * @cmd: command to assign serial number to | |
629 | * | |
630 | * Description: a serial number identifies a request for error recovery | |
1da177e4 LT |
631 | * and debugging purposes. Protected by the Host_Lock of host. |
632 | */ | |
633 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
634 | { | |
635 | cmd->serial_number = host->cmd_serial_number++; | |
636 | if (cmd->serial_number == 0) | |
637 | cmd->serial_number = host->cmd_serial_number++; | |
1da177e4 LT |
638 | } |
639 | ||
eb44820c RL |
640 | /** |
641 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
642 | * @cmd: command block we are dispatching. | |
1da177e4 | 643 | * |
eb44820c RL |
644 | * Return: nonzero return request was rejected and device's queue needs to be |
645 | * plugged. | |
1da177e4 LT |
646 | */ |
647 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
648 | { | |
649 | struct Scsi_Host *host = cmd->device->host; | |
650 | unsigned long flags = 0; | |
651 | unsigned long timeout; | |
652 | int rtn = 0; | |
653 | ||
242f9dcb JA |
654 | /* |
655 | * We will use a queued command if possible, otherwise we will | |
656 | * emulate the queuing and calling of completion function ourselves. | |
657 | */ | |
658 | atomic_inc(&cmd->device->iorequest_cnt); | |
659 | ||
1da177e4 LT |
660 | /* check if the device is still usable */ |
661 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
662 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
663 | * returns an immediate error upwards, and signals | |
664 | * that the device is no longer present */ | |
665 | cmd->result = DID_NO_CONNECT << 16; | |
242f9dcb | 666 | scsi_done(cmd); |
1da177e4 LT |
667 | /* return 0 (because the command has been processed) */ |
668 | goto out; | |
669 | } | |
670 | ||
671 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
672 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
673 | /* | |
674 | * in SDEV_BLOCK, the command is just put back on the device | |
675 | * queue. The suspend state has already blocked the queue so | |
676 | * future requests should not occur until the device | |
677 | * transitions out of the suspend state. | |
678 | */ | |
242f9dcb | 679 | |
1da177e4 LT |
680 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
681 | ||
682 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
683 | ||
684 | /* | |
685 | * NOTE: rtn is still zero here because we don't need the | |
686 | * queue to be plugged on return (it's already stopped) | |
687 | */ | |
688 | goto out; | |
689 | } | |
690 | ||
691 | /* | |
692 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
693 | */ | |
4d7db04a JB |
694 | if (cmd->device->scsi_level <= SCSI_2 && |
695 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
696 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
697 | (cmd->device->lun << 5 & 0xe0); | |
698 | } | |
699 | ||
700 | /* | |
701 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
702 | * we can avoid the drive not being ready. | |
703 | */ | |
704 | timeout = host->last_reset + MIN_RESET_DELAY; | |
705 | ||
706 | if (host->resetting && time_before(jiffies, timeout)) { | |
707 | int ticks_remaining = timeout - jiffies; | |
708 | /* | |
709 | * NOTE: This may be executed from within an interrupt | |
710 | * handler! This is bad, but for now, it'll do. The irq | |
711 | * level of the interrupt handler has been masked out by the | |
712 | * platform dependent interrupt handling code already, so the | |
713 | * sti() here will not cause another call to the SCSI host's | |
714 | * interrupt handler (assuming there is one irq-level per | |
715 | * host). | |
716 | */ | |
717 | while (--ticks_remaining >= 0) | |
718 | mdelay(1 + 999 / HZ); | |
719 | host->resetting = 0; | |
720 | } | |
721 | ||
1da177e4 LT |
722 | scsi_log_send(cmd); |
723 | ||
1da177e4 LT |
724 | /* |
725 | * Before we queue this command, check if the command | |
726 | * length exceeds what the host adapter can handle. | |
727 | */ | |
db4742dd | 728 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { |
1da177e4 | 729 | SCSI_LOG_MLQUEUE(3, |
db4742dd BH |
730 | printk("queuecommand : command too long. " |
731 | "cdb_size=%d host->max_cmd_len=%d\n", | |
732 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1da177e4 LT |
733 | cmd->result = (DID_ABORT << 16); |
734 | ||
735 | scsi_done(cmd); | |
736 | goto out; | |
737 | } | |
738 | ||
739 | spin_lock_irqsave(host->host_lock, flags); | |
242f9dcb JA |
740 | /* |
741 | * AK: unlikely race here: for some reason the timer could | |
742 | * expire before the serial number is set up below. | |
743 | * | |
744 | * TODO: kill serial or move to blk layer | |
745 | */ | |
1da177e4 LT |
746 | scsi_cmd_get_serial(host, cmd); |
747 | ||
d2c9d9ea | 748 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
749 | cmd->result = (DID_NO_CONNECT << 16); |
750 | scsi_done(cmd); | |
751 | } else { | |
752 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
753 | } | |
754 | spin_unlock_irqrestore(host->host_lock, flags); | |
755 | if (rtn) { | |
242f9dcb JA |
756 | scsi_queue_insert(cmd, (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? |
757 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
1da177e4 LT |
758 | SCSI_LOG_MLQUEUE(3, |
759 | printk("queuecommand : request rejected\n")); | |
760 | } | |
761 | ||
762 | out: | |
763 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
764 | return rtn; | |
765 | } | |
766 | ||
1da177e4 LT |
767 | /** |
768 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
769 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
770 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
771 | * | |
eb44820c RL |
772 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
773 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
774 | * enqueues the command to the done queue for further processing. | |
1da177e4 LT |
775 | * |
776 | * This is the producer of the done queue who enqueues at the tail. | |
777 | * | |
778 | * This function is interrupt context safe. | |
779 | */ | |
52c1da39 | 780 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 | 781 | { |
242f9dcb | 782 | blk_complete_request(cmd->request); |
1da177e4 LT |
783 | } |
784 | ||
7b3d9545 LT |
785 | /* Move this to a header if it becomes more generally useful */ |
786 | static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) | |
787 | { | |
788 | return *(struct scsi_driver **)cmd->request->rq_disk->private_data; | |
789 | } | |
790 | ||
eb44820c RL |
791 | /** |
792 | * scsi_finish_command - cleanup and pass command back to upper layer | |
793 | * @cmd: the command | |
1da177e4 | 794 | * |
eb44820c | 795 | * Description: Pass command off to upper layer for finishing of I/O |
1da177e4 LT |
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_Host *shost = sdev->host; | |
7b3d9545 LT |
803 | struct scsi_driver *drv; |
804 | unsigned int good_bytes; | |
1da177e4 LT |
805 | |
806 | scsi_device_unbusy(sdev); | |
807 | ||
808 | /* | |
809 | * Clear the flags which say that the device/host is no longer | |
810 | * capable of accepting new commands. These are set in scsi_queue.c | |
811 | * for both the queue full condition on a device, and for a | |
812 | * host full condition on the host. | |
813 | * | |
814 | * XXX(hch): What about locking? | |
815 | */ | |
816 | shost->host_blocked = 0; | |
817 | sdev->device_blocked = 0; | |
818 | ||
819 | /* | |
820 | * If we have valid sense information, then some kind of recovery | |
821 | * must have taken place. Make a note of this. | |
822 | */ | |
823 | if (SCSI_SENSE_VALID(cmd)) | |
824 | cmd->result |= (DRIVER_SENSE << 24); | |
825 | ||
3bf743e7 JG |
826 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
827 | "Notifying upper driver of completion " | |
828 | "(result %x)\n", cmd->result)); | |
1da177e4 | 829 | |
f18573ab | 830 | good_bytes = scsi_bufflen(cmd); |
7b3d9545 | 831 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { |
427e59f0 | 832 | int old_good_bytes = good_bytes; |
7b3d9545 LT |
833 | drv = scsi_cmd_to_driver(cmd); |
834 | if (drv->done) | |
835 | good_bytes = drv->done(cmd); | |
427e59f0 JB |
836 | /* |
837 | * USB may not give sense identifying bad sector and | |
838 | * simply return a residue instead, so subtract off the | |
839 | * residue if drv->done() error processing indicates no | |
840 | * change to the completion length. | |
841 | */ | |
842 | if (good_bytes == old_good_bytes) | |
843 | good_bytes -= scsi_get_resid(cmd); | |
7b3d9545 LT |
844 | } |
845 | scsi_io_completion(cmd, good_bytes); | |
1da177e4 LT |
846 | } |
847 | EXPORT_SYMBOL(scsi_finish_command); | |
848 | ||
eb44820c RL |
849 | /** |
850 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth | |
851 | * @sdev: SCSI Device in question | |
852 | * @tagged: Do we use tagged queueing (non-0) or do we treat | |
853 | * this device as an untagged device (0) | |
854 | * @tags: Number of tags allowed if tagged queueing enabled, | |
855 | * or number of commands the low level driver can | |
856 | * queue up in non-tagged mode (as per cmd_per_lun). | |
1da177e4 LT |
857 | * |
858 | * Returns: Nothing | |
859 | * | |
860 | * Lock Status: None held on entry | |
861 | * | |
862 | * Notes: Low level drivers may call this at any time and we will do | |
863 | * the right thing depending on whether or not the device is | |
864 | * currently active and whether or not it even has the | |
865 | * command blocks built yet. | |
866 | */ | |
867 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
868 | { | |
869 | unsigned long flags; | |
870 | ||
871 | /* | |
872 | * refuse to set tagged depth to an unworkable size | |
873 | */ | |
874 | if (tags <= 0) | |
875 | return; | |
876 | ||
877 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
878 | ||
885ace9e MC |
879 | /* |
880 | * Check to see if the queue is managed by the block layer. | |
881 | * If it is, and we fail to adjust the depth, exit. | |
882 | * | |
883 | * Do not resize the tag map if it is a host wide share bqt, | |
884 | * because the size should be the hosts's can_queue. If there | |
885 | * is more IO than the LLD's can_queue (so there are not enuogh | |
886 | * tags) request_fn's host queue ready check will handle it. | |
887 | */ | |
888 | if (!sdev->host->bqt) { | |
889 | if (blk_queue_tagged(sdev->request_queue) && | |
890 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
891 | goto out; | |
892 | } | |
1da177e4 LT |
893 | |
894 | sdev->queue_depth = tags; | |
895 | switch (tagged) { | |
896 | case MSG_ORDERED_TAG: | |
897 | sdev->ordered_tags = 1; | |
898 | sdev->simple_tags = 1; | |
899 | break; | |
900 | case MSG_SIMPLE_TAG: | |
901 | sdev->ordered_tags = 0; | |
902 | sdev->simple_tags = 1; | |
903 | break; | |
904 | default: | |
9ccfc756 JB |
905 | sdev_printk(KERN_WARNING, sdev, |
906 | "scsi_adjust_queue_depth, bad queue type, " | |
907 | "disabled\n"); | |
1da177e4 LT |
908 | case 0: |
909 | sdev->ordered_tags = sdev->simple_tags = 0; | |
910 | sdev->queue_depth = tags; | |
911 | break; | |
912 | } | |
913 | out: | |
914 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
915 | } | |
916 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
917 | ||
eb44820c RL |
918 | /** |
919 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth | |
920 | * @sdev: SCSI Device in question | |
921 | * @depth: Current number of outstanding SCSI commands on this device, | |
922 | * not counting the one returned as QUEUE_FULL. | |
1da177e4 | 923 | * |
eb44820c | 924 | * Description: This function will track successive QUEUE_FULL events on a |
1da177e4 LT |
925 | * specific SCSI device to determine if and when there is a |
926 | * need to adjust the queue depth on the device. | |
927 | * | |
eb44820c | 928 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
1da177e4 LT |
929 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
930 | * as the untagged command depth | |
931 | * | |
932 | * Lock Status: None held on entry | |
933 | * | |
934 | * Notes: Low level drivers may call this at any time and we will do | |
935 | * "The Right Thing." We are interrupt context safe. | |
936 | */ | |
937 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
938 | { | |
939 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
940 | return 0; | |
941 | ||
942 | sdev->last_queue_full_time = (jiffies >> 4); | |
943 | if (sdev->last_queue_full_depth != depth) { | |
944 | sdev->last_queue_full_count = 1; | |
945 | sdev->last_queue_full_depth = depth; | |
946 | } else { | |
947 | sdev->last_queue_full_count++; | |
948 | } | |
949 | ||
950 | if (sdev->last_queue_full_count <= 10) | |
951 | return 0; | |
952 | if (sdev->last_queue_full_depth < 8) { | |
953 | /* Drop back to untagged */ | |
954 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
955 | return -1; | |
956 | } | |
957 | ||
958 | if (sdev->ordered_tags) | |
959 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
960 | else | |
961 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
962 | return depth; | |
963 | } | |
964 | EXPORT_SYMBOL(scsi_track_queue_full); | |
965 | ||
966 | /** | |
eb44820c | 967 | * scsi_device_get - get an additional reference to a scsi_device |
1da177e4 LT |
968 | * @sdev: device to get a reference to |
969 | * | |
eb44820c | 970 | * Description: Gets a reference to the scsi_device and increments the use count |
1da177e4 LT |
971 | * of the underlying LLDD module. You must hold host_lock of the |
972 | * parent Scsi_Host or already have a reference when calling this. | |
973 | */ | |
974 | int scsi_device_get(struct scsi_device *sdev) | |
975 | { | |
85b6c720 | 976 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
977 | return -ENXIO; |
978 | if (!get_device(&sdev->sdev_gendev)) | |
979 | return -ENXIO; | |
85b6c720 JB |
980 | /* We can fail this if we're doing SCSI operations |
981 | * from module exit (like cache flush) */ | |
982 | try_module_get(sdev->host->hostt->module); | |
983 | ||
1da177e4 LT |
984 | return 0; |
985 | } | |
986 | EXPORT_SYMBOL(scsi_device_get); | |
987 | ||
988 | /** | |
989 | * scsi_device_put - release a reference to a scsi_device | |
990 | * @sdev: device to release a reference on. | |
991 | * | |
eb44820c RL |
992 | * Description: Release a reference to the scsi_device and decrements the use |
993 | * count of the underlying LLDD module. The device is freed once the last | |
1da177e4 LT |
994 | * user vanishes. |
995 | */ | |
996 | void scsi_device_put(struct scsi_device *sdev) | |
997 | { | |
504fb37a | 998 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
999 | struct module *module = sdev->host->hostt->module; |
1000 | ||
85b6c720 JB |
1001 | /* The module refcount will be zero if scsi_device_get() |
1002 | * was called from a module removal routine */ | |
f479ab87 JB |
1003 | if (module && module_refcount(module) != 0) |
1004 | module_put(module); | |
a506b44b | 1005 | #endif |
1da177e4 LT |
1006 | put_device(&sdev->sdev_gendev); |
1007 | } | |
1008 | EXPORT_SYMBOL(scsi_device_put); | |
1009 | ||
eb44820c | 1010 | /* helper for shost_for_each_device, see that for documentation */ |
1da177e4 LT |
1011 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
1012 | struct scsi_device *prev) | |
1013 | { | |
1014 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
1015 | struct scsi_device *next = NULL; | |
1016 | unsigned long flags; | |
1017 | ||
1018 | spin_lock_irqsave(shost->host_lock, flags); | |
1019 | while (list->next != &shost->__devices) { | |
1020 | next = list_entry(list->next, struct scsi_device, siblings); | |
1021 | /* skip devices that we can't get a reference to */ | |
1022 | if (!scsi_device_get(next)) | |
1023 | break; | |
1024 | next = NULL; | |
1025 | list = list->next; | |
1026 | } | |
1027 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1028 | ||
1029 | if (prev) | |
1030 | scsi_device_put(prev); | |
1031 | return next; | |
1032 | } | |
1033 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
1034 | ||
1035 | /** | |
1036 | * starget_for_each_device - helper to walk all devices of a target | |
1037 | * @starget: target whose devices we want to iterate over. | |
eb44820c RL |
1038 | * @data: Opaque passed to each function call. |
1039 | * @fn: Function to call on each device | |
1da177e4 | 1040 | * |
522939d4 | 1041 | * This traverses over each device of @starget. The devices have |
1da177e4 LT |
1042 | * a reference that must be released by scsi_host_put when breaking |
1043 | * out of the loop. | |
1044 | */ | |
522939d4 | 1045 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1da177e4 LT |
1046 | void (*fn)(struct scsi_device *, void *)) |
1047 | { | |
1048 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1049 | struct scsi_device *sdev; | |
1050 | ||
1051 | shost_for_each_device(sdev, shost) { | |
1052 | if ((sdev->channel == starget->channel) && | |
1053 | (sdev->id == starget->id)) | |
1054 | fn(sdev, data); | |
1055 | } | |
1056 | } | |
1057 | EXPORT_SYMBOL(starget_for_each_device); | |
1058 | ||
522939d4 | 1059 | /** |
14f501a4 | 1060 | * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
522939d4 | 1061 | * @starget: target whose devices we want to iterate over. |
14f501a4 RD |
1062 | * @data: parameter for callback @fn() |
1063 | * @fn: callback function that is invoked for each device | |
522939d4 MR |
1064 | * |
1065 | * This traverses over each device of @starget. It does _not_ | |
1066 | * take a reference on the scsi_device, so the whole loop must be | |
1067 | * protected by shost->host_lock. | |
1068 | * | |
1069 | * Note: The only reason why drivers would want to use this is because | |
1070 | * they need to access the device list in irq context. Otherwise you | |
1071 | * really want to use starget_for_each_device instead. | |
1072 | **/ | |
1073 | void __starget_for_each_device(struct scsi_target *starget, void *data, | |
1074 | void (*fn)(struct scsi_device *, void *)) | |
1075 | { | |
1076 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1077 | struct scsi_device *sdev; | |
1078 | ||
1079 | __shost_for_each_device(sdev, shost) { | |
1080 | if ((sdev->channel == starget->channel) && | |
1081 | (sdev->id == starget->id)) | |
1082 | fn(sdev, data); | |
1083 | } | |
1084 | } | |
1085 | EXPORT_SYMBOL(__starget_for_each_device); | |
1086 | ||
1da177e4 LT |
1087 | /** |
1088 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
1089 | * @starget: SCSI target pointer | |
1090 | * @lun: SCSI Logical Unit Number | |
1091 | * | |
eb44820c RL |
1092 | * Description: Looks up the scsi_device with the specified @lun for a given |
1093 | * @starget. The returned scsi_device does not have an additional | |
1da177e4 LT |
1094 | * reference. You must hold the host's host_lock over this call and |
1095 | * any access to the returned scsi_device. | |
1096 | * | |
dc8875e1 | 1097 | * Note: The only reason why drivers should use this is because |
eb44820c | 1098 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1099 | * really want to use scsi_device_lookup_by_target instead. |
1100 | **/ | |
1101 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
1102 | uint lun) | |
1103 | { | |
1104 | struct scsi_device *sdev; | |
1105 | ||
1106 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
1107 | if (sdev->lun ==lun) | |
1108 | return sdev; | |
1109 | } | |
1110 | ||
1111 | return NULL; | |
1112 | } | |
1113 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
1114 | ||
1115 | /** | |
1116 | * scsi_device_lookup_by_target - find a device given the target | |
1117 | * @starget: SCSI target pointer | |
1118 | * @lun: SCSI Logical Unit Number | |
1119 | * | |
eb44820c RL |
1120 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1121 | * for a given host. The returned scsi_device has an additional reference that | |
1122 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1123 | **/ |
1124 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
1125 | uint lun) | |
1126 | { | |
1127 | struct scsi_device *sdev; | |
1128 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1129 | unsigned long flags; | |
1130 | ||
1131 | spin_lock_irqsave(shost->host_lock, flags); | |
1132 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
1133 | if (sdev && scsi_device_get(sdev)) | |
1134 | sdev = NULL; | |
1135 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1136 | ||
1137 | return sdev; | |
1138 | } | |
1139 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1140 | ||
1141 | /** | |
eb44820c | 1142 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1da177e4 LT |
1143 | * @shost: SCSI host pointer |
1144 | * @channel: SCSI channel (zero if only one channel) | |
eb44820c | 1145 | * @id: SCSI target number (physical unit number) |
1da177e4 LT |
1146 | * @lun: SCSI Logical Unit Number |
1147 | * | |
eb44820c RL |
1148 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1149 | * for a given host. The returned scsi_device does not have an additional | |
1150 | * reference. You must hold the host's host_lock over this call and any access | |
1151 | * to the returned scsi_device. | |
1da177e4 LT |
1152 | * |
1153 | * Note: The only reason why drivers would want to use this is because | |
eb44820c | 1154 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1155 | * really want to use scsi_device_lookup instead. |
1156 | **/ | |
1157 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1158 | uint channel, uint id, uint lun) | |
1159 | { | |
1160 | struct scsi_device *sdev; | |
1161 | ||
1162 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1163 | if (sdev->channel == channel && sdev->id == id && | |
1164 | sdev->lun ==lun) | |
1165 | return sdev; | |
1166 | } | |
1167 | ||
1168 | return NULL; | |
1169 | } | |
1170 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1171 | ||
1172 | /** | |
1173 | * scsi_device_lookup - find a device given the host | |
1174 | * @shost: SCSI host pointer | |
1175 | * @channel: SCSI channel (zero if only one channel) | |
1176 | * @id: SCSI target number (physical unit number) | |
1177 | * @lun: SCSI Logical Unit Number | |
1178 | * | |
eb44820c RL |
1179 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1180 | * for a given host. The returned scsi_device has an additional reference that | |
1181 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1182 | **/ |
1183 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1184 | uint channel, uint id, uint lun) | |
1185 | { | |
1186 | struct scsi_device *sdev; | |
1187 | unsigned long flags; | |
1188 | ||
1189 | spin_lock_irqsave(shost->host_lock, flags); | |
1190 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1191 | if (sdev && scsi_device_get(sdev)) | |
1192 | sdev = NULL; | |
1193 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1194 | ||
1195 | return sdev; | |
1196 | } | |
1197 | EXPORT_SYMBOL(scsi_device_lookup); | |
1198 | ||
1da177e4 LT |
1199 | MODULE_DESCRIPTION("SCSI core"); |
1200 | MODULE_LICENSE("GPL"); | |
1201 | ||
1202 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1203 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1204 | ||
1205 | static int __init init_scsi(void) | |
1206 | { | |
9bf09c23 | 1207 | int error; |
1da177e4 LT |
1208 | |
1209 | error = scsi_init_queue(); | |
1210 | if (error) | |
1211 | return error; | |
1212 | error = scsi_init_procfs(); | |
1213 | if (error) | |
1214 | goto cleanup_queue; | |
1215 | error = scsi_init_devinfo(); | |
1216 | if (error) | |
1217 | goto cleanup_procfs; | |
1218 | error = scsi_init_hosts(); | |
1219 | if (error) | |
1220 | goto cleanup_devlist; | |
1221 | error = scsi_init_sysctl(); | |
1222 | if (error) | |
1223 | goto cleanup_hosts; | |
1224 | error = scsi_sysfs_register(); | |
1225 | if (error) | |
1226 | goto cleanup_sysctl; | |
1227 | ||
84314fd4 JS |
1228 | scsi_netlink_init(); |
1229 | ||
1da177e4 LT |
1230 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1231 | return 0; | |
1232 | ||
1233 | cleanup_sysctl: | |
1234 | scsi_exit_sysctl(); | |
1235 | cleanup_hosts: | |
1236 | scsi_exit_hosts(); | |
1237 | cleanup_devlist: | |
1238 | scsi_exit_devinfo(); | |
1239 | cleanup_procfs: | |
1240 | scsi_exit_procfs(); | |
1241 | cleanup_queue: | |
1242 | scsi_exit_queue(); | |
1243 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1244 | -error); | |
1245 | return error; | |
1246 | } | |
1247 | ||
1248 | static void __exit exit_scsi(void) | |
1249 | { | |
84314fd4 | 1250 | scsi_netlink_exit(); |
1da177e4 LT |
1251 | scsi_sysfs_unregister(); |
1252 | scsi_exit_sysctl(); | |
1253 | scsi_exit_hosts(); | |
1254 | scsi_exit_devinfo(); | |
1da177e4 LT |
1255 | scsi_exit_procfs(); |
1256 | scsi_exit_queue(); | |
1da177e4 LT |
1257 | } |
1258 | ||
1259 | subsys_initcall(init_scsi); | |
1260 | module_exit(exit_scsi); |