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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 | ||
bf816235 KT |
70 | #define CREATE_TRACE_POINTS |
71 | #include <trace/events/scsi.h> | |
72 | ||
52c1da39 | 73 | static void scsi_done(struct scsi_cmnd *cmd); |
1da177e4 LT |
74 | |
75 | /* | |
76 | * Definitions and constants. | |
77 | */ | |
78 | ||
79 | #define MIN_RESET_DELAY (2*HZ) | |
80 | ||
81 | /* Do not call reset on error if we just did a reset within 15 sec. */ | |
82 | #define MIN_RESET_PERIOD (15*HZ) | |
83 | ||
1da177e4 LT |
84 | /* |
85 | * Note - the initial logging level can be set here to log events at boot time. | |
86 | * After the system is up, you may enable logging via the /proc interface. | |
87 | */ | |
88 | unsigned int scsi_logging_level; | |
89 | #if defined(CONFIG_SCSI_LOGGING) | |
90 | EXPORT_SYMBOL(scsi_logging_level); | |
91 | #endif | |
92 | ||
8a1cdc9c MW |
93 | /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. |
94 | * You may not alter any existing entry (although adding new ones is | |
95 | * encouraged once assigned by ANSI/INCITS T10 | |
96 | */ | |
4ff36718 | 97 | static const char *const scsi_device_types[] = { |
8a1cdc9c MW |
98 | "Direct-Access ", |
99 | "Sequential-Access", | |
1da177e4 LT |
100 | "Printer ", |
101 | "Processor ", | |
102 | "WORM ", | |
8a1cdc9c | 103 | "CD-ROM ", |
1da177e4 | 104 | "Scanner ", |
8a1cdc9c MW |
105 | "Optical Device ", |
106 | "Medium Changer ", | |
1da177e4 | 107 | "Communications ", |
4ff36718 MW |
108 | "ASC IT8 ", |
109 | "ASC IT8 ", | |
1da177e4 LT |
110 | "RAID ", |
111 | "Enclosure ", | |
8a1cdc9c | 112 | "Direct-Access-RBC", |
4ff36718 MW |
113 | "Optical card ", |
114 | "Bridge controller", | |
115 | "Object storage ", | |
116 | "Automation/Drive ", | |
1da177e4 | 117 | }; |
4ff36718 | 118 | |
eb44820c RL |
119 | /** |
120 | * scsi_device_type - Return 17 char string indicating device type. | |
121 | * @type: type number to look up | |
122 | */ | |
123 | ||
4ff36718 MW |
124 | const char * scsi_device_type(unsigned type) |
125 | { | |
126 | if (type == 0x1e) | |
127 | return "Well-known LUN "; | |
128 | if (type == 0x1f) | |
129 | return "No Device "; | |
80c6e3c0 | 130 | if (type >= ARRAY_SIZE(scsi_device_types)) |
4ff36718 MW |
131 | return "Unknown "; |
132 | return scsi_device_types[type]; | |
133 | } | |
134 | ||
135 | EXPORT_SYMBOL(scsi_device_type); | |
1da177e4 | 136 | |
1da177e4 | 137 | struct scsi_host_cmd_pool { |
5b7f1680 JB |
138 | struct kmem_cache *cmd_slab; |
139 | struct kmem_cache *sense_slab; | |
140 | unsigned int users; | |
141 | char *cmd_name; | |
142 | char *sense_name; | |
143 | unsigned int slab_flags; | |
144 | gfp_t gfp_mask; | |
1da177e4 LT |
145 | }; |
146 | ||
147 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
5b7f1680 JB |
148 | .cmd_name = "scsi_cmd_cache", |
149 | .sense_name = "scsi_sense_cache", | |
1da177e4 LT |
150 | .slab_flags = SLAB_HWCACHE_ALIGN, |
151 | }; | |
152 | ||
153 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
5b7f1680 JB |
154 | .cmd_name = "scsi_cmd_cache(DMA)", |
155 | .sense_name = "scsi_sense_cache(DMA)", | |
1da177e4 LT |
156 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, |
157 | .gfp_mask = __GFP_DMA, | |
158 | }; | |
159 | ||
0b950672 | 160 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 161 | |
e507e30b JB |
162 | /** |
163 | * scsi_pool_alloc_command - internal function to get a fully allocated command | |
164 | * @pool: slab pool to allocate the command from | |
165 | * @gfp_mask: mask for the allocation | |
166 | * | |
167 | * Returns a fully allocated command (with the allied sense buffer) or | |
168 | * NULL on failure | |
169 | */ | |
170 | static struct scsi_cmnd * | |
171 | scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask) | |
172 | { | |
173 | struct scsi_cmnd *cmd; | |
174 | ||
ebef264b | 175 | cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); |
e507e30b JB |
176 | if (!cmd) |
177 | return NULL; | |
178 | ||
e507e30b JB |
179 | cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, |
180 | gfp_mask | pool->gfp_mask); | |
181 | if (!cmd->sense_buffer) { | |
182 | kmem_cache_free(pool->cmd_slab, cmd); | |
183 | return NULL; | |
184 | } | |
185 | ||
186 | return cmd; | |
187 | } | |
188 | ||
189 | /** | |
190 | * scsi_pool_free_command - internal function to release a command | |
191 | * @pool: slab pool to allocate the command from | |
192 | * @cmd: command to release | |
193 | * | |
194 | * the command must previously have been allocated by | |
195 | * scsi_pool_alloc_command. | |
196 | */ | |
197 | static void | |
198 | scsi_pool_free_command(struct scsi_host_cmd_pool *pool, | |
199 | struct scsi_cmnd *cmd) | |
200 | { | |
7027ad72 MP |
201 | if (cmd->prot_sdb) |
202 | kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); | |
203 | ||
e507e30b JB |
204 | kmem_cache_free(pool->sense_slab, cmd->sense_buffer); |
205 | kmem_cache_free(pool->cmd_slab, cmd); | |
206 | } | |
207 | ||
7027ad72 MP |
208 | /** |
209 | * scsi_host_alloc_command - internal function to allocate command | |
210 | * @shost: SCSI host whose pool to allocate from | |
211 | * @gfp_mask: mask for the allocation | |
212 | * | |
213 | * Returns a fully allocated command with sense buffer and protection | |
214 | * data buffer (where applicable) or NULL on failure | |
215 | */ | |
216 | static struct scsi_cmnd * | |
217 | scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) | |
218 | { | |
219 | struct scsi_cmnd *cmd; | |
220 | ||
221 | cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask); | |
222 | if (!cmd) | |
223 | return NULL; | |
224 | ||
225 | if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { | |
226 | cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); | |
227 | ||
228 | if (!cmd->prot_sdb) { | |
229 | scsi_pool_free_command(shost->cmd_pool, cmd); | |
230 | return NULL; | |
231 | } | |
232 | } | |
233 | ||
234 | return cmd; | |
235 | } | |
236 | ||
eb44820c RL |
237 | /** |
238 | * __scsi_get_command - Allocate a struct scsi_cmnd | |
239 | * @shost: host to transmit command | |
240 | * @gfp_mask: allocation mask | |
241 | * | |
242 | * Description: allocate a struct scsi_cmd from host's slab, recycling from the | |
243 | * host's free_list if necessary. | |
244 | */ | |
b58d9154 | 245 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 | 246 | { |
b4c2554d | 247 | struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask); |
164fc5dc | 248 | |
1da177e4 LT |
249 | if (unlikely(!cmd)) { |
250 | unsigned long flags; | |
251 | ||
252 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
253 | if (likely(!list_empty(&shost->free_list))) { | |
254 | cmd = list_entry(shost->free_list.next, | |
255 | struct scsi_cmnd, list); | |
256 | list_del_init(&cmd->list); | |
257 | } | |
258 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
de25deb1 FT |
259 | |
260 | if (cmd) { | |
b4c2554d MP |
261 | void *buf, *prot; |
262 | ||
de25deb1 | 263 | buf = cmd->sense_buffer; |
b4c2554d MP |
264 | prot = cmd->prot_sdb; |
265 | ||
de25deb1 | 266 | memset(cmd, 0, sizeof(*cmd)); |
b4c2554d | 267 | |
de25deb1 | 268 | cmd->sense_buffer = buf; |
b4c2554d | 269 | cmd->prot_sdb = prot; |
de25deb1 | 270 | } |
1da177e4 LT |
271 | } |
272 | ||
273 | return cmd; | |
274 | } | |
b58d9154 | 275 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 | 276 | |
eb44820c RL |
277 | /** |
278 | * scsi_get_command - Allocate and setup a scsi command block | |
279 | * @dev: parent scsi device | |
280 | * @gfp_mask: allocator flags | |
1da177e4 LT |
281 | * |
282 | * Returns: The allocated scsi command structure. | |
283 | */ | |
c53033f6 | 284 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
285 | { |
286 | struct scsi_cmnd *cmd; | |
287 | ||
288 | /* Bail if we can't get a reference to the device */ | |
289 | if (!get_device(&dev->sdev_gendev)) | |
290 | return NULL; | |
291 | ||
292 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
293 | ||
294 | if (likely(cmd != NULL)) { | |
295 | unsigned long flags; | |
296 | ||
1da177e4 | 297 | cmd->device = dev; |
1da177e4 LT |
298 | INIT_LIST_HEAD(&cmd->list); |
299 | spin_lock_irqsave(&dev->list_lock, flags); | |
300 | list_add_tail(&cmd->list, &dev->cmd_list); | |
301 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 302 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
303 | } else |
304 | put_device(&dev->sdev_gendev); | |
305 | ||
306 | return cmd; | |
b58d9154 | 307 | } |
1da177e4 LT |
308 | EXPORT_SYMBOL(scsi_get_command); |
309 | ||
eb44820c RL |
310 | /** |
311 | * __scsi_put_command - Free a struct scsi_cmnd | |
312 | * @shost: dev->host | |
313 | * @cmd: Command to free | |
314 | * @dev: parent scsi device | |
315 | */ | |
b58d9154 FT |
316 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
317 | struct device *dev) | |
318 | { | |
319 | unsigned long flags; | |
320 | ||
321 | /* changing locks here, don't need to restore the irq state */ | |
322 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
323 | if (unlikely(list_empty(&shost->free_list))) { | |
324 | list_add(&cmd->list, &shost->free_list); | |
325 | cmd = NULL; | |
326 | } | |
327 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
328 | ||
e507e30b JB |
329 | if (likely(cmd != NULL)) |
330 | scsi_pool_free_command(shost->cmd_pool, cmd); | |
b58d9154 FT |
331 | |
332 | put_device(dev); | |
333 | } | |
334 | EXPORT_SYMBOL(__scsi_put_command); | |
335 | ||
eb44820c RL |
336 | /** |
337 | * scsi_put_command - Free a scsi command block | |
338 | * @cmd: command block to free | |
1da177e4 LT |
339 | * |
340 | * Returns: Nothing. | |
341 | * | |
342 | * Notes: The command must not belong to any lists. | |
343 | */ | |
344 | void scsi_put_command(struct scsi_cmnd *cmd) | |
345 | { | |
346 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 347 | unsigned long flags; |
b58d9154 | 348 | |
1da177e4 LT |
349 | /* serious error if the command hasn't come from a device list */ |
350 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
351 | BUG_ON(list_empty(&cmd->list)); | |
352 | list_del_init(&cmd->list); | |
b58d9154 | 353 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 354 | |
b58d9154 | 355 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
356 | } |
357 | EXPORT_SYMBOL(scsi_put_command); | |
358 | ||
1c353f7d | 359 | static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask) |
1da177e4 | 360 | { |
1c353f7d | 361 | struct scsi_host_cmd_pool *retval = NULL, *pool; |
1da177e4 LT |
362 | /* |
363 | * Select a command slab for this host and create it if not | |
eb44820c | 364 | * yet existent. |
1da177e4 | 365 | */ |
0b950672 | 366 | mutex_lock(&host_cmd_pool_mutex); |
1c353f7d JB |
367 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
368 | &scsi_cmd_pool; | |
1da177e4 | 369 | if (!pool->users) { |
5b7f1680 JB |
370 | pool->cmd_slab = kmem_cache_create(pool->cmd_name, |
371 | sizeof(struct scsi_cmnd), 0, | |
372 | pool->slab_flags, NULL); | |
373 | if (!pool->cmd_slab) | |
374 | goto fail; | |
375 | ||
376 | pool->sense_slab = kmem_cache_create(pool->sense_name, | |
377 | SCSI_SENSE_BUFFERSIZE, 0, | |
378 | pool->slab_flags, NULL); | |
379 | if (!pool->sense_slab) { | |
380 | kmem_cache_destroy(pool->cmd_slab); | |
1da177e4 | 381 | goto fail; |
5b7f1680 | 382 | } |
1da177e4 LT |
383 | } |
384 | ||
385 | pool->users++; | |
1c353f7d JB |
386 | retval = pool; |
387 | fail: | |
0b950672 | 388 | mutex_unlock(&host_cmd_pool_mutex); |
1c353f7d JB |
389 | return retval; |
390 | } | |
391 | ||
392 | static void scsi_put_host_cmd_pool(gfp_t gfp_mask) | |
393 | { | |
394 | struct scsi_host_cmd_pool *pool; | |
1da177e4 | 395 | |
1c353f7d JB |
396 | mutex_lock(&host_cmd_pool_mutex); |
397 | pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : | |
398 | &scsi_cmd_pool; | |
1da177e4 | 399 | /* |
1c353f7d JB |
400 | * This may happen if a driver has a mismatched get and put |
401 | * of the command pool; the driver should be implicated in | |
402 | * the stack trace | |
1da177e4 | 403 | */ |
1c353f7d | 404 | BUG_ON(pool->users == 0); |
de25deb1 | 405 | |
5b7f1680 JB |
406 | if (!--pool->users) { |
407 | kmem_cache_destroy(pool->cmd_slab); | |
408 | kmem_cache_destroy(pool->sense_slab); | |
409 | } | |
0b950672 | 410 | mutex_unlock(&host_cmd_pool_mutex); |
1c353f7d JB |
411 | } |
412 | ||
413 | /** | |
414 | * scsi_allocate_command - get a fully allocated SCSI command | |
415 | * @gfp_mask: allocation mask | |
416 | * | |
417 | * This function is for use outside of the normal host based pools. | |
418 | * It allocates the relevant command and takes an additional reference | |
419 | * on the pool it used. This function *must* be paired with | |
420 | * scsi_free_command which also has the identical mask, otherwise the | |
421 | * free pool counts will eventually go wrong and you'll trigger a bug. | |
422 | * | |
423 | * This function should *only* be used by drivers that need a static | |
424 | * command allocation at start of day for internal functions. | |
425 | */ | |
426 | struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask) | |
427 | { | |
428 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); | |
429 | ||
430 | if (!pool) | |
431 | return NULL; | |
432 | ||
433 | return scsi_pool_alloc_command(pool, gfp_mask); | |
434 | } | |
435 | EXPORT_SYMBOL(scsi_allocate_command); | |
436 | ||
437 | /** | |
438 | * scsi_free_command - free a command allocated by scsi_allocate_command | |
439 | * @gfp_mask: mask used in the original allocation | |
440 | * @cmd: command to free | |
441 | * | |
442 | * Note: using the original allocation mask is vital because that's | |
443 | * what determines which command pool we use to free the command. Any | |
444 | * mismatch will cause the system to BUG eventually. | |
445 | */ | |
446 | void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd) | |
447 | { | |
448 | struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); | |
449 | ||
450 | /* | |
451 | * this could trigger if the mask to scsi_allocate_command | |
452 | * doesn't match this mask. Otherwise we're guaranteed that this | |
453 | * succeeds because scsi_allocate_command must have taken a reference | |
454 | * on the pool | |
455 | */ | |
456 | BUG_ON(!pool); | |
457 | ||
458 | scsi_pool_free_command(pool, cmd); | |
459 | /* | |
460 | * scsi_put_host_cmd_pool is called twice; once to release the | |
461 | * reference we took above, and once to release the reference | |
462 | * originally taken by scsi_allocate_command | |
463 | */ | |
464 | scsi_put_host_cmd_pool(gfp_mask); | |
465 | scsi_put_host_cmd_pool(gfp_mask); | |
466 | } | |
467 | EXPORT_SYMBOL(scsi_free_command); | |
468 | ||
469 | /** | |
470 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. | |
471 | * @shost: host to allocate the freelist for. | |
472 | * | |
473 | * Description: The command freelist protects against system-wide out of memory | |
474 | * deadlock by preallocating one SCSI command structure for each host, so the | |
475 | * system can always write to a swap file on a device associated with that host. | |
476 | * | |
477 | * Returns: Nothing. | |
478 | */ | |
479 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
480 | { | |
481 | struct scsi_cmnd *cmd; | |
482 | const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; | |
483 | ||
484 | spin_lock_init(&shost->free_list_lock); | |
485 | INIT_LIST_HEAD(&shost->free_list); | |
486 | ||
487 | shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask); | |
488 | ||
489 | if (!shost->cmd_pool) | |
490 | return -ENOMEM; | |
491 | ||
492 | /* | |
493 | * Get one backup command for this host. | |
494 | */ | |
7027ad72 | 495 | cmd = scsi_host_alloc_command(shost, gfp_mask); |
1c353f7d JB |
496 | if (!cmd) { |
497 | scsi_put_host_cmd_pool(gfp_mask); | |
61d7416a | 498 | shost->cmd_pool = NULL; |
1c353f7d JB |
499 | return -ENOMEM; |
500 | } | |
501 | list_add(&cmd->list, &shost->free_list); | |
502 | return 0; | |
1da177e4 LT |
503 | } |
504 | ||
eb44820c RL |
505 | /** |
506 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. | |
507 | * @shost: host whose freelist is going to be destroyed | |
1da177e4 LT |
508 | */ |
509 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
510 | { | |
61d7416a AB |
511 | /* |
512 | * If cmd_pool is NULL the free list was not initialized, so | |
513 | * do not attempt to release resources. | |
514 | */ | |
515 | if (!shost->cmd_pool) | |
516 | return; | |
517 | ||
1da177e4 LT |
518 | while (!list_empty(&shost->free_list)) { |
519 | struct scsi_cmnd *cmd; | |
520 | ||
521 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
522 | list_del_init(&cmd->list); | |
e507e30b | 523 | scsi_pool_free_command(shost->cmd_pool, cmd); |
1da177e4 | 524 | } |
1c353f7d JB |
525 | shost->cmd_pool = NULL; |
526 | scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL); | |
de25deb1 FT |
527 | } |
528 | ||
1da177e4 LT |
529 | #ifdef CONFIG_SCSI_LOGGING |
530 | void scsi_log_send(struct scsi_cmnd *cmd) | |
531 | { | |
532 | unsigned int level; | |
1da177e4 LT |
533 | |
534 | /* | |
535 | * If ML QUEUE log level is greater than or equal to: | |
536 | * | |
537 | * 1: nothing (match completion) | |
538 | * | |
539 | * 2: log opcode + command of all commands | |
540 | * | |
541 | * 3: same as 2 plus dump cmd address | |
542 | * | |
543 | * 4: same as 3 plus dump extra junk | |
544 | */ | |
545 | if (unlikely(scsi_logging_level)) { | |
546 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
547 | SCSI_LOG_MLQUEUE_BITS); | |
548 | if (level > 1) { | |
a4d04a4c | 549 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
550 | if (level > 2) |
551 | printk("0x%p ", cmd); | |
a4d04a4c | 552 | printk("\n"); |
1da177e4 LT |
553 | scsi_print_command(cmd); |
554 | if (level > 3) { | |
555 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
7b3d9545 | 556 | " queuecommand 0x%p\n", |
a73e45b3 | 557 | scsi_sglist(cmd), scsi_bufflen(cmd), |
a4d04a4c | 558 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
559 | |
560 | } | |
561 | } | |
562 | } | |
563 | } | |
564 | ||
565 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
566 | { | |
567 | unsigned int level; | |
1da177e4 LT |
568 | |
569 | /* | |
570 | * If ML COMPLETE log level is greater than or equal to: | |
571 | * | |
572 | * 1: log disposition, result, opcode + command, and conditionally | |
573 | * sense data for failures or non SUCCESS dispositions. | |
574 | * | |
575 | * 2: same as 1 but for all command completions. | |
576 | * | |
577 | * 3: same as 2 plus dump cmd address | |
578 | * | |
579 | * 4: same as 3 plus dump extra junk | |
580 | */ | |
581 | if (unlikely(scsi_logging_level)) { | |
582 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
583 | SCSI_LOG_MLCOMPLETE_BITS); | |
584 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
585 | (level > 1)) { | |
a4d04a4c | 586 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
587 | if (level > 2) |
588 | printk("0x%p ", cmd); | |
589 | /* | |
590 | * Dump truncated values, so we usually fit within | |
591 | * 80 chars. | |
592 | */ | |
593 | switch (disposition) { | |
594 | case SUCCESS: | |
a4d04a4c | 595 | printk("SUCCESS\n"); |
1da177e4 LT |
596 | break; |
597 | case NEEDS_RETRY: | |
a4d04a4c | 598 | printk("RETRY\n"); |
1da177e4 LT |
599 | break; |
600 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 601 | printk("MLQUEUE\n"); |
1da177e4 LT |
602 | break; |
603 | case FAILED: | |
a4d04a4c | 604 | printk("FAILED\n"); |
1da177e4 LT |
605 | break; |
606 | case TIMEOUT_ERROR: | |
607 | /* | |
608 | * If called via scsi_times_out. | |
609 | */ | |
a4d04a4c | 610 | printk("TIMEOUT\n"); |
1da177e4 LT |
611 | break; |
612 | default: | |
a4d04a4c | 613 | printk("UNKNOWN\n"); |
1da177e4 | 614 | } |
a4d04a4c | 615 | scsi_print_result(cmd); |
1da177e4 | 616 | scsi_print_command(cmd); |
a4d04a4c | 617 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 618 | scsi_print_sense("", cmd); |
a4d04a4c MP |
619 | if (level > 3) |
620 | scmd_printk(KERN_INFO, cmd, | |
621 | "scsi host busy %d failed %d\n", | |
622 | cmd->device->host->host_busy, | |
623 | cmd->device->host->host_failed); | |
1da177e4 LT |
624 | } |
625 | } | |
626 | } | |
627 | #endif | |
628 | ||
eb44820c RL |
629 | /** |
630 | * scsi_cmd_get_serial - Assign a serial number to a command | |
631 | * @host: the scsi host | |
632 | * @cmd: command to assign serial number to | |
633 | * | |
634 | * Description: a serial number identifies a request for error recovery | |
1da177e4 LT |
635 | * and debugging purposes. Protected by the Host_Lock of host. |
636 | */ | |
637 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
638 | { | |
639 | cmd->serial_number = host->cmd_serial_number++; | |
640 | if (cmd->serial_number == 0) | |
641 | cmd->serial_number = host->cmd_serial_number++; | |
1da177e4 LT |
642 | } |
643 | ||
eb44820c RL |
644 | /** |
645 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
646 | * @cmd: command block we are dispatching. | |
1da177e4 | 647 | * |
eb44820c RL |
648 | * Return: nonzero return request was rejected and device's queue needs to be |
649 | * plugged. | |
1da177e4 LT |
650 | */ |
651 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
652 | { | |
653 | struct Scsi_Host *host = cmd->device->host; | |
654 | unsigned long flags = 0; | |
655 | unsigned long timeout; | |
656 | int rtn = 0; | |
657 | ||
242f9dcb JA |
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 | ||
0f1d87a2 JB |
671 | /* Check to see if the scsi lld made this device blocked. */ |
672 | if (unlikely(scsi_device_blocked(cmd->device))) { | |
1da177e4 | 673 | /* |
0f1d87a2 JB |
674 | * in blocked state, the command is just put back on |
675 | * the device queue. The suspend state has already | |
676 | * blocked the queue so future requests should not | |
677 | * occur until the device transitions out of the | |
678 | * suspend state. | |
1da177e4 | 679 | */ |
242f9dcb | 680 | |
1da177e4 LT |
681 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
682 | ||
683 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
684 | ||
685 | /* | |
686 | * NOTE: rtn is still zero here because we don't need the | |
687 | * queue to be plugged on return (it's already stopped) | |
688 | */ | |
689 | goto out; | |
690 | } | |
691 | ||
692 | /* | |
693 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
694 | */ | |
4d7db04a JB |
695 | if (cmd->device->scsi_level <= SCSI_2 && |
696 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
697 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
698 | (cmd->device->lun << 5 & 0xe0); | |
699 | } | |
700 | ||
701 | /* | |
702 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
703 | * we can avoid the drive not being ready. | |
704 | */ | |
705 | timeout = host->last_reset + MIN_RESET_DELAY; | |
706 | ||
707 | if (host->resetting && time_before(jiffies, timeout)) { | |
708 | int ticks_remaining = timeout - jiffies; | |
709 | /* | |
710 | * NOTE: This may be executed from within an interrupt | |
711 | * handler! This is bad, but for now, it'll do. The irq | |
712 | * level of the interrupt handler has been masked out by the | |
713 | * platform dependent interrupt handling code already, so the | |
714 | * sti() here will not cause another call to the SCSI host's | |
715 | * interrupt handler (assuming there is one irq-level per | |
716 | * host). | |
717 | */ | |
718 | while (--ticks_remaining >= 0) | |
719 | mdelay(1 + 999 / HZ); | |
720 | host->resetting = 0; | |
721 | } | |
722 | ||
1da177e4 LT |
723 | scsi_log_send(cmd); |
724 | ||
1da177e4 LT |
725 | /* |
726 | * Before we queue this command, check if the command | |
727 | * length exceeds what the host adapter can handle. | |
728 | */ | |
db4742dd | 729 | if (cmd->cmd_len > cmd->device->host->max_cmd_len) { |
1da177e4 | 730 | SCSI_LOG_MLQUEUE(3, |
db4742dd BH |
731 | printk("queuecommand : command too long. " |
732 | "cdb_size=%d host->max_cmd_len=%d\n", | |
733 | cmd->cmd_len, cmd->device->host->max_cmd_len)); | |
1da177e4 LT |
734 | cmd->result = (DID_ABORT << 16); |
735 | ||
736 | scsi_done(cmd); | |
737 | goto out; | |
738 | } | |
739 | ||
740 | spin_lock_irqsave(host->host_lock, flags); | |
242f9dcb JA |
741 | /* |
742 | * AK: unlikely race here: for some reason the timer could | |
743 | * expire before the serial number is set up below. | |
744 | * | |
745 | * TODO: kill serial or move to blk layer | |
746 | */ | |
1da177e4 LT |
747 | scsi_cmd_get_serial(host, cmd); |
748 | ||
d2c9d9ea | 749 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
750 | cmd->result = (DID_NO_CONNECT << 16); |
751 | scsi_done(cmd); | |
752 | } else { | |
bf816235 | 753 | trace_scsi_dispatch_cmd_start(cmd); |
1da177e4 LT |
754 | rtn = host->hostt->queuecommand(cmd, scsi_done); |
755 | } | |
756 | spin_unlock_irqrestore(host->host_lock, flags); | |
757 | if (rtn) { | |
bf816235 | 758 | trace_scsi_dispatch_cmd_error(cmd, rtn); |
f0c0a376 MC |
759 | if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && |
760 | rtn != SCSI_MLQUEUE_TARGET_BUSY) | |
761 | rtn = SCSI_MLQUEUE_HOST_BUSY; | |
762 | ||
763 | scsi_queue_insert(cmd, rtn); | |
764 | ||
1da177e4 LT |
765 | SCSI_LOG_MLQUEUE(3, |
766 | printk("queuecommand : request rejected\n")); | |
767 | } | |
768 | ||
769 | out: | |
770 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
771 | return rtn; | |
772 | } | |
773 | ||
1da177e4 LT |
774 | /** |
775 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
776 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
777 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
778 | * | |
eb44820c RL |
779 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
780 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
781 | * enqueues the command to the done queue for further processing. | |
1da177e4 LT |
782 | * |
783 | * This is the producer of the done queue who enqueues at the tail. | |
784 | * | |
785 | * This function is interrupt context safe. | |
786 | */ | |
52c1da39 | 787 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 | 788 | { |
bf816235 | 789 | trace_scsi_dispatch_cmd_done(cmd); |
242f9dcb | 790 | blk_complete_request(cmd->request); |
1da177e4 LT |
791 | } |
792 | ||
7b3d9545 LT |
793 | /* Move this to a header if it becomes more generally useful */ |
794 | static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) | |
795 | { | |
796 | return *(struct scsi_driver **)cmd->request->rq_disk->private_data; | |
797 | } | |
798 | ||
eb44820c RL |
799 | /** |
800 | * scsi_finish_command - cleanup and pass command back to upper layer | |
801 | * @cmd: the command | |
1da177e4 | 802 | * |
eb44820c | 803 | * Description: Pass command off to upper layer for finishing of I/O |
1da177e4 LT |
804 | * request, waking processes that are waiting on results, |
805 | * etc. | |
806 | */ | |
807 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
808 | { | |
809 | struct scsi_device *sdev = cmd->device; | |
f0c0a376 | 810 | struct scsi_target *starget = scsi_target(sdev); |
1da177e4 | 811 | struct Scsi_Host *shost = sdev->host; |
7b3d9545 LT |
812 | struct scsi_driver *drv; |
813 | unsigned int good_bytes; | |
1da177e4 LT |
814 | |
815 | scsi_device_unbusy(sdev); | |
816 | ||
817 | /* | |
818 | * Clear the flags which say that the device/host is no longer | |
819 | * capable of accepting new commands. These are set in scsi_queue.c | |
820 | * for both the queue full condition on a device, and for a | |
821 | * host full condition on the host. | |
822 | * | |
823 | * XXX(hch): What about locking? | |
824 | */ | |
825 | shost->host_blocked = 0; | |
f0c0a376 | 826 | starget->target_blocked = 0; |
1da177e4 LT |
827 | sdev->device_blocked = 0; |
828 | ||
829 | /* | |
830 | * If we have valid sense information, then some kind of recovery | |
831 | * must have taken place. Make a note of this. | |
832 | */ | |
833 | if (SCSI_SENSE_VALID(cmd)) | |
834 | cmd->result |= (DRIVER_SENSE << 24); | |
835 | ||
3bf743e7 JG |
836 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
837 | "Notifying upper driver of completion " | |
838 | "(result %x)\n", cmd->result)); | |
1da177e4 | 839 | |
f18573ab | 840 | good_bytes = scsi_bufflen(cmd); |
7b3d9545 | 841 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { |
427e59f0 | 842 | int old_good_bytes = good_bytes; |
7b3d9545 LT |
843 | drv = scsi_cmd_to_driver(cmd); |
844 | if (drv->done) | |
845 | good_bytes = drv->done(cmd); | |
427e59f0 JB |
846 | /* |
847 | * USB may not give sense identifying bad sector and | |
848 | * simply return a residue instead, so subtract off the | |
849 | * residue if drv->done() error processing indicates no | |
850 | * change to the completion length. | |
851 | */ | |
852 | if (good_bytes == old_good_bytes) | |
853 | good_bytes -= scsi_get_resid(cmd); | |
7b3d9545 LT |
854 | } |
855 | scsi_io_completion(cmd, good_bytes); | |
1da177e4 LT |
856 | } |
857 | EXPORT_SYMBOL(scsi_finish_command); | |
858 | ||
eb44820c RL |
859 | /** |
860 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth | |
861 | * @sdev: SCSI Device in question | |
862 | * @tagged: Do we use tagged queueing (non-0) or do we treat | |
863 | * this device as an untagged device (0) | |
864 | * @tags: Number of tags allowed if tagged queueing enabled, | |
865 | * or number of commands the low level driver can | |
866 | * queue up in non-tagged mode (as per cmd_per_lun). | |
1da177e4 LT |
867 | * |
868 | * Returns: Nothing | |
869 | * | |
870 | * Lock Status: None held on entry | |
871 | * | |
872 | * Notes: Low level drivers may call this at any time and we will do | |
873 | * the right thing depending on whether or not the device is | |
874 | * currently active and whether or not it even has the | |
875 | * command blocks built yet. | |
876 | */ | |
877 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
878 | { | |
879 | unsigned long flags; | |
880 | ||
881 | /* | |
882 | * refuse to set tagged depth to an unworkable size | |
883 | */ | |
884 | if (tags <= 0) | |
885 | return; | |
886 | ||
887 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
888 | ||
885ace9e MC |
889 | /* |
890 | * Check to see if the queue is managed by the block layer. | |
891 | * If it is, and we fail to adjust the depth, exit. | |
892 | * | |
893 | * Do not resize the tag map if it is a host wide share bqt, | |
894 | * because the size should be the hosts's can_queue. If there | |
895 | * is more IO than the LLD's can_queue (so there are not enuogh | |
896 | * tags) request_fn's host queue ready check will handle it. | |
897 | */ | |
898 | if (!sdev->host->bqt) { | |
899 | if (blk_queue_tagged(sdev->request_queue) && | |
900 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
901 | goto out; | |
902 | } | |
1da177e4 LT |
903 | |
904 | sdev->queue_depth = tags; | |
905 | switch (tagged) { | |
906 | case MSG_ORDERED_TAG: | |
907 | sdev->ordered_tags = 1; | |
908 | sdev->simple_tags = 1; | |
909 | break; | |
910 | case MSG_SIMPLE_TAG: | |
911 | sdev->ordered_tags = 0; | |
912 | sdev->simple_tags = 1; | |
913 | break; | |
914 | default: | |
9ccfc756 JB |
915 | sdev_printk(KERN_WARNING, sdev, |
916 | "scsi_adjust_queue_depth, bad queue type, " | |
917 | "disabled\n"); | |
1da177e4 LT |
918 | case 0: |
919 | sdev->ordered_tags = sdev->simple_tags = 0; | |
920 | sdev->queue_depth = tags; | |
921 | break; | |
922 | } | |
923 | out: | |
924 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
925 | } | |
926 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
927 | ||
eb44820c RL |
928 | /** |
929 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth | |
930 | * @sdev: SCSI Device in question | |
931 | * @depth: Current number of outstanding SCSI commands on this device, | |
932 | * not counting the one returned as QUEUE_FULL. | |
1da177e4 | 933 | * |
eb44820c | 934 | * Description: This function will track successive QUEUE_FULL events on a |
1da177e4 LT |
935 | * specific SCSI device to determine if and when there is a |
936 | * need to adjust the queue depth on the device. | |
937 | * | |
eb44820c | 938 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
1da177e4 LT |
939 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
940 | * as the untagged command depth | |
941 | * | |
942 | * Lock Status: None held on entry | |
943 | * | |
944 | * Notes: Low level drivers may call this at any time and we will do | |
945 | * "The Right Thing." We are interrupt context safe. | |
946 | */ | |
947 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
948 | { | |
4a84067d VD |
949 | |
950 | /* | |
951 | * Don't let QUEUE_FULLs on the same | |
952 | * jiffies count, they could all be from | |
953 | * same event. | |
954 | */ | |
955 | if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) | |
1da177e4 LT |
956 | return 0; |
957 | ||
4a84067d | 958 | sdev->last_queue_full_time = jiffies; |
1da177e4 LT |
959 | if (sdev->last_queue_full_depth != depth) { |
960 | sdev->last_queue_full_count = 1; | |
961 | sdev->last_queue_full_depth = depth; | |
962 | } else { | |
963 | sdev->last_queue_full_count++; | |
964 | } | |
965 | ||
966 | if (sdev->last_queue_full_count <= 10) | |
967 | return 0; | |
968 | if (sdev->last_queue_full_depth < 8) { | |
969 | /* Drop back to untagged */ | |
970 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
971 | return -1; | |
972 | } | |
973 | ||
974 | if (sdev->ordered_tags) | |
975 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
976 | else | |
977 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
978 | return depth; | |
979 | } | |
980 | EXPORT_SYMBOL(scsi_track_queue_full); | |
981 | ||
881a256d MW |
982 | /** |
983 | * scsi_vpd_inquiry - Request a device provide us with a VPD page | |
984 | * @sdev: The device to ask | |
985 | * @buffer: Where to put the result | |
986 | * @page: Which Vital Product Data to return | |
987 | * @len: The length of the buffer | |
988 | * | |
989 | * This is an internal helper function. You probably want to use | |
990 | * scsi_get_vpd_page instead. | |
991 | * | |
992 | * Returns 0 on success or a negative error number. | |
993 | */ | |
994 | static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, | |
995 | u8 page, unsigned len) | |
996 | { | |
997 | int result; | |
998 | unsigned char cmd[16]; | |
999 | ||
1000 | cmd[0] = INQUIRY; | |
1001 | cmd[1] = 1; /* EVPD */ | |
1002 | cmd[2] = page; | |
1003 | cmd[3] = len >> 8; | |
1004 | cmd[4] = len & 0xff; | |
1005 | cmd[5] = 0; /* Control byte */ | |
1006 | ||
1007 | /* | |
1008 | * I'm not convinced we need to try quite this hard to get VPD, but | |
1009 | * all the existing users tried this hard. | |
1010 | */ | |
1011 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, | |
95a3639e | 1012 | len, NULL, 30 * HZ, 3, NULL); |
881a256d MW |
1013 | if (result) |
1014 | return result; | |
1015 | ||
1016 | /* Sanity check that we got the page back that we asked for */ | |
1017 | if (buffer[1] != page) | |
1018 | return -EIO; | |
1019 | ||
1020 | return 0; | |
1021 | } | |
1022 | ||
1023 | /** | |
1024 | * scsi_get_vpd_page - Get Vital Product Data from a SCSI device | |
1025 | * @sdev: The device to ask | |
1026 | * @page: Which Vital Product Data to return | |
786f8ba2 RD |
1027 | * @buf: where to store the VPD |
1028 | * @buf_len: number of bytes in the VPD buffer area | |
881a256d MW |
1029 | * |
1030 | * SCSI devices may optionally supply Vital Product Data. Each 'page' | |
1031 | * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). | |
1032 | * If the device supports this VPD page, this routine returns a pointer | |
1033 | * to a buffer containing the data from that page. The caller is | |
1034 | * responsible for calling kfree() on this pointer when it is no longer | |
1035 | * needed. If we cannot retrieve the VPD page this routine returns %NULL. | |
1036 | */ | |
e3deec09 JB |
1037 | int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, |
1038 | int buf_len) | |
881a256d MW |
1039 | { |
1040 | int i, result; | |
881a256d MW |
1041 | |
1042 | /* Ask for all the pages supported by this device */ | |
e3deec09 | 1043 | result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); |
881a256d MW |
1044 | if (result) |
1045 | goto fail; | |
1046 | ||
1047 | /* If the user actually wanted this page, we can skip the rest */ | |
1048 | if (page == 0) | |
e3deec09 | 1049 | return -EINVAL; |
881a256d | 1050 | |
e3deec09 | 1051 | for (i = 0; i < min((int)buf[3], buf_len - 4); i++) |
881a256d MW |
1052 | if (buf[i + 4] == page) |
1053 | goto found; | |
e3deec09 JB |
1054 | |
1055 | if (i < buf[3] && i > buf_len) | |
1056 | /* ran off the end of the buffer, give us benefit of doubt */ | |
1057 | goto found; | |
881a256d MW |
1058 | /* The device claims it doesn't support the requested page */ |
1059 | goto fail; | |
1060 | ||
1061 | found: | |
e3deec09 | 1062 | result = scsi_vpd_inquiry(sdev, buf, page, buf_len); |
881a256d MW |
1063 | if (result) |
1064 | goto fail; | |
1065 | ||
e3deec09 | 1066 | return 0; |
881a256d MW |
1067 | |
1068 | fail: | |
e3deec09 | 1069 | return -EINVAL; |
881a256d MW |
1070 | } |
1071 | EXPORT_SYMBOL_GPL(scsi_get_vpd_page); | |
1072 | ||
1da177e4 | 1073 | /** |
eb44820c | 1074 | * scsi_device_get - get an additional reference to a scsi_device |
1da177e4 LT |
1075 | * @sdev: device to get a reference to |
1076 | * | |
eb44820c | 1077 | * Description: Gets a reference to the scsi_device and increments the use count |
1da177e4 LT |
1078 | * of the underlying LLDD module. You must hold host_lock of the |
1079 | * parent Scsi_Host or already have a reference when calling this. | |
1080 | */ | |
1081 | int scsi_device_get(struct scsi_device *sdev) | |
1082 | { | |
85b6c720 | 1083 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
1084 | return -ENXIO; |
1085 | if (!get_device(&sdev->sdev_gendev)) | |
1086 | return -ENXIO; | |
85b6c720 JB |
1087 | /* We can fail this if we're doing SCSI operations |
1088 | * from module exit (like cache flush) */ | |
1089 | try_module_get(sdev->host->hostt->module); | |
1090 | ||
1da177e4 LT |
1091 | return 0; |
1092 | } | |
1093 | EXPORT_SYMBOL(scsi_device_get); | |
1094 | ||
1095 | /** | |
1096 | * scsi_device_put - release a reference to a scsi_device | |
1097 | * @sdev: device to release a reference on. | |
1098 | * | |
eb44820c RL |
1099 | * Description: Release a reference to the scsi_device and decrements the use |
1100 | * count of the underlying LLDD module. The device is freed once the last | |
1da177e4 LT |
1101 | * user vanishes. |
1102 | */ | |
1103 | void scsi_device_put(struct scsi_device *sdev) | |
1104 | { | |
504fb37a | 1105 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
1106 | struct module *module = sdev->host->hostt->module; |
1107 | ||
85b6c720 JB |
1108 | /* The module refcount will be zero if scsi_device_get() |
1109 | * was called from a module removal routine */ | |
f479ab87 JB |
1110 | if (module && module_refcount(module) != 0) |
1111 | module_put(module); | |
a506b44b | 1112 | #endif |
1da177e4 LT |
1113 | put_device(&sdev->sdev_gendev); |
1114 | } | |
1115 | EXPORT_SYMBOL(scsi_device_put); | |
1116 | ||
eb44820c | 1117 | /* helper for shost_for_each_device, see that for documentation */ |
1da177e4 LT |
1118 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
1119 | struct scsi_device *prev) | |
1120 | { | |
1121 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
1122 | struct scsi_device *next = NULL; | |
1123 | unsigned long flags; | |
1124 | ||
1125 | spin_lock_irqsave(shost->host_lock, flags); | |
1126 | while (list->next != &shost->__devices) { | |
1127 | next = list_entry(list->next, struct scsi_device, siblings); | |
1128 | /* skip devices that we can't get a reference to */ | |
1129 | if (!scsi_device_get(next)) | |
1130 | break; | |
1131 | next = NULL; | |
1132 | list = list->next; | |
1133 | } | |
1134 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1135 | ||
1136 | if (prev) | |
1137 | scsi_device_put(prev); | |
1138 | return next; | |
1139 | } | |
1140 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
1141 | ||
1142 | /** | |
1143 | * starget_for_each_device - helper to walk all devices of a target | |
1144 | * @starget: target whose devices we want to iterate over. | |
eb44820c RL |
1145 | * @data: Opaque passed to each function call. |
1146 | * @fn: Function to call on each device | |
1da177e4 | 1147 | * |
522939d4 | 1148 | * This traverses over each device of @starget. The devices have |
1da177e4 LT |
1149 | * a reference that must be released by scsi_host_put when breaking |
1150 | * out of the loop. | |
1151 | */ | |
522939d4 | 1152 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1da177e4 LT |
1153 | void (*fn)(struct scsi_device *, void *)) |
1154 | { | |
1155 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1156 | struct scsi_device *sdev; | |
1157 | ||
1158 | shost_for_each_device(sdev, shost) { | |
1159 | if ((sdev->channel == starget->channel) && | |
1160 | (sdev->id == starget->id)) | |
1161 | fn(sdev, data); | |
1162 | } | |
1163 | } | |
1164 | EXPORT_SYMBOL(starget_for_each_device); | |
1165 | ||
522939d4 | 1166 | /** |
14f501a4 | 1167 | * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
522939d4 | 1168 | * @starget: target whose devices we want to iterate over. |
14f501a4 RD |
1169 | * @data: parameter for callback @fn() |
1170 | * @fn: callback function that is invoked for each device | |
522939d4 MR |
1171 | * |
1172 | * This traverses over each device of @starget. It does _not_ | |
1173 | * take a reference on the scsi_device, so the whole loop must be | |
1174 | * protected by shost->host_lock. | |
1175 | * | |
1176 | * Note: The only reason why drivers would want to use this is because | |
1177 | * they need to access the device list in irq context. Otherwise you | |
1178 | * really want to use starget_for_each_device instead. | |
1179 | **/ | |
1180 | void __starget_for_each_device(struct scsi_target *starget, void *data, | |
1181 | void (*fn)(struct scsi_device *, void *)) | |
1182 | { | |
1183 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1184 | struct scsi_device *sdev; | |
1185 | ||
1186 | __shost_for_each_device(sdev, shost) { | |
1187 | if ((sdev->channel == starget->channel) && | |
1188 | (sdev->id == starget->id)) | |
1189 | fn(sdev, data); | |
1190 | } | |
1191 | } | |
1192 | EXPORT_SYMBOL(__starget_for_each_device); | |
1193 | ||
1da177e4 LT |
1194 | /** |
1195 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
1196 | * @starget: SCSI target pointer | |
1197 | * @lun: SCSI Logical Unit Number | |
1198 | * | |
eb44820c RL |
1199 | * Description: Looks up the scsi_device with the specified @lun for a given |
1200 | * @starget. The returned scsi_device does not have an additional | |
1da177e4 | 1201 | * reference. You must hold the host's host_lock over this call and |
32aeef60 HR |
1202 | * any access to the returned scsi_device. A scsi_device in state |
1203 | * SDEV_DEL is skipped. | |
1da177e4 | 1204 | * |
dc8875e1 | 1205 | * Note: The only reason why drivers should use this is because |
eb44820c | 1206 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1207 | * really want to use scsi_device_lookup_by_target instead. |
1208 | **/ | |
1209 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
1210 | uint lun) | |
1211 | { | |
1212 | struct scsi_device *sdev; | |
1213 | ||
1214 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
32aeef60 HR |
1215 | if (sdev->sdev_state == SDEV_DEL) |
1216 | continue; | |
1da177e4 LT |
1217 | if (sdev->lun ==lun) |
1218 | return sdev; | |
1219 | } | |
1220 | ||
1221 | return NULL; | |
1222 | } | |
1223 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
1224 | ||
1225 | /** | |
1226 | * scsi_device_lookup_by_target - find a device given the target | |
1227 | * @starget: SCSI target pointer | |
1228 | * @lun: SCSI Logical Unit Number | |
1229 | * | |
477e608c BZ |
1230 | * Description: Looks up the scsi_device with the specified @lun for a given |
1231 | * @starget. The returned scsi_device has an additional reference that | |
eb44820c | 1232 | * needs to be released with scsi_device_put once you're done with it. |
1da177e4 LT |
1233 | **/ |
1234 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
1235 | uint lun) | |
1236 | { | |
1237 | struct scsi_device *sdev; | |
1238 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1239 | unsigned long flags; | |
1240 | ||
1241 | spin_lock_irqsave(shost->host_lock, flags); | |
1242 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
1243 | if (sdev && scsi_device_get(sdev)) | |
1244 | sdev = NULL; | |
1245 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1246 | ||
1247 | return sdev; | |
1248 | } | |
1249 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1250 | ||
1251 | /** | |
eb44820c | 1252 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1da177e4 LT |
1253 | * @shost: SCSI host pointer |
1254 | * @channel: SCSI channel (zero if only one channel) | |
eb44820c | 1255 | * @id: SCSI target number (physical unit number) |
1da177e4 LT |
1256 | * @lun: SCSI Logical Unit Number |
1257 | * | |
eb44820c RL |
1258 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1259 | * for a given host. The returned scsi_device does not have an additional | |
1260 | * reference. You must hold the host's host_lock over this call and any access | |
1261 | * to the returned scsi_device. | |
1da177e4 LT |
1262 | * |
1263 | * Note: The only reason why drivers would want to use this is because | |
eb44820c | 1264 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1265 | * really want to use scsi_device_lookup instead. |
1266 | **/ | |
1267 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1268 | uint channel, uint id, uint lun) | |
1269 | { | |
1270 | struct scsi_device *sdev; | |
1271 | ||
1272 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1273 | if (sdev->channel == channel && sdev->id == id && | |
1274 | sdev->lun ==lun) | |
1275 | return sdev; | |
1276 | } | |
1277 | ||
1278 | return NULL; | |
1279 | } | |
1280 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1281 | ||
1282 | /** | |
1283 | * scsi_device_lookup - find a device given the host | |
1284 | * @shost: SCSI host pointer | |
1285 | * @channel: SCSI channel (zero if only one channel) | |
1286 | * @id: SCSI target number (physical unit number) | |
1287 | * @lun: SCSI Logical Unit Number | |
1288 | * | |
eb44820c RL |
1289 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1290 | * for a given host. The returned scsi_device has an additional reference that | |
1291 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1292 | **/ |
1293 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1294 | uint channel, uint id, uint lun) | |
1295 | { | |
1296 | struct scsi_device *sdev; | |
1297 | unsigned long flags; | |
1298 | ||
1299 | spin_lock_irqsave(shost->host_lock, flags); | |
1300 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1301 | if (sdev && scsi_device_get(sdev)) | |
1302 | sdev = NULL; | |
1303 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1304 | ||
1305 | return sdev; | |
1306 | } | |
1307 | EXPORT_SYMBOL(scsi_device_lookup); | |
1308 | ||
1da177e4 LT |
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 | { | |
9bf09c23 | 1317 | int error; |
1da177e4 LT |
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 | ||
84314fd4 JS |
1338 | scsi_netlink_init(); |
1339 | ||
1da177e4 LT |
1340 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1341 | return 0; | |
1342 | ||
1343 | cleanup_sysctl: | |
1344 | scsi_exit_sysctl(); | |
1345 | cleanup_hosts: | |
1346 | scsi_exit_hosts(); | |
1347 | cleanup_devlist: | |
1348 | scsi_exit_devinfo(); | |
1349 | cleanup_procfs: | |
1350 | scsi_exit_procfs(); | |
1351 | cleanup_queue: | |
1352 | scsi_exit_queue(); | |
1353 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1354 | -error); | |
1355 | return error; | |
1356 | } | |
1357 | ||
1358 | static void __exit exit_scsi(void) | |
1359 | { | |
84314fd4 | 1360 | scsi_netlink_exit(); |
1da177e4 LT |
1361 | scsi_sysfs_unregister(); |
1362 | scsi_exit_sysctl(); | |
1363 | scsi_exit_hosts(); | |
1364 | scsi_exit_devinfo(); | |
1da177e4 LT |
1365 | scsi_exit_procfs(); |
1366 | scsi_exit_queue(); | |
1da177e4 LT |
1367 | } |
1368 | ||
1369 | subsys_initcall(init_scsi); | |
1370 | module_exit(exit_scsi); |