]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * scsi.c Copyright (C) 1992 Drew Eckhardt | |
3 | * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale | |
4 | * Copyright (C) 2002, 2003 Christoph Hellwig | |
5 | * | |
6 | * generic mid-level SCSI driver | |
7 | * Initial versions: Drew Eckhardt | |
8 | * Subsequent revisions: Eric Youngdale | |
9 | * | |
10 | * <drew@colorado.edu> | |
11 | * | |
12 | * Bug correction thanks go to : | |
13 | * Rik Faith <faith@cs.unc.edu> | |
14 | * Tommy Thorn <tthorn> | |
15 | * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de> | |
16 | * | |
17 | * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to | |
18 | * add scatter-gather, multiple outstanding request, and other | |
19 | * enhancements. | |
20 | * | |
21 | * Native multichannel, wide scsi, /proc/scsi and hot plugging | |
22 | * support added by Michael Neuffer <mike@i-connect.net> | |
23 | * | |
24 | * Added request_module("scsi_hostadapter") for kerneld: | |
25 | * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) | |
26 | * Bjorn Ekwall <bj0rn@blox.se> | |
27 | * (changed to kmod) | |
28 | * | |
29 | * Major improvements to the timeout, abort, and reset processing, | |
30 | * as well as performance modifications for large queue depths by | |
31 | * Leonard N. Zubkoff <lnz@dandelion.com> | |
32 | * | |
33 | * Converted cli() code to spinlocks, Ingo Molnar | |
34 | * | |
35 | * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli | |
36 | * | |
37 | * out_of_space hacks, D. Gilbert (dpg) 990608 | |
38 | */ | |
39 | ||
40 | #include <linux/module.h> | |
41 | #include <linux/moduleparam.h> | |
42 | #include <linux/kernel.h> | |
1da177e4 LT |
43 | #include <linux/timer.h> |
44 | #include <linux/string.h> | |
45 | #include <linux/slab.h> | |
46 | #include <linux/blkdev.h> | |
47 | #include <linux/delay.h> | |
48 | #include <linux/init.h> | |
49 | #include <linux/completion.h> | |
1da177e4 LT |
50 | #include <linux/unistd.h> |
51 | #include <linux/spinlock.h> | |
52 | #include <linux/kmod.h> | |
53 | #include <linux/interrupt.h> | |
54 | #include <linux/notifier.h> | |
55 | #include <linux/cpu.h> | |
0b950672 | 56 | #include <linux/mutex.h> |
1da177e4 LT |
57 | |
58 | #include <scsi/scsi.h> | |
59 | #include <scsi/scsi_cmnd.h> | |
60 | #include <scsi/scsi_dbg.h> | |
61 | #include <scsi/scsi_device.h> | |
7b3d9545 | 62 | #include <scsi/scsi_driver.h> |
1da177e4 LT |
63 | #include <scsi/scsi_eh.h> |
64 | #include <scsi/scsi_host.h> | |
65 | #include <scsi/scsi_tcq.h> | |
1da177e4 LT |
66 | |
67 | #include "scsi_priv.h" | |
68 | #include "scsi_logging.h" | |
69 | ||
52c1da39 | 70 | static void scsi_done(struct scsi_cmnd *cmd); |
1da177e4 LT |
71 | |
72 | /* | |
73 | * Definitions and constants. | |
74 | */ | |
75 | ||
76 | #define MIN_RESET_DELAY (2*HZ) | |
77 | ||
78 | /* Do not call reset on error if we just did a reset within 15 sec. */ | |
79 | #define MIN_RESET_PERIOD (15*HZ) | |
80 | ||
81 | /* | |
82 | * Macro to determine the size of SCSI command. This macro takes vendor | |
83 | * unique commands into account. SCSI commands in groups 6 and 7 are | |
84 | * vendor unique and we will depend upon the command length being | |
85 | * supplied correctly in cmd_len. | |
86 | */ | |
87 | #define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \ | |
88 | COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len) | |
89 | ||
90 | /* | |
91 | * Note - the initial logging level can be set here to log events at boot time. | |
92 | * After the system is up, you may enable logging via the /proc interface. | |
93 | */ | |
94 | unsigned int scsi_logging_level; | |
95 | #if defined(CONFIG_SCSI_LOGGING) | |
96 | EXPORT_SYMBOL(scsi_logging_level); | |
97 | #endif | |
98 | ||
8a1cdc9c MW |
99 | /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. |
100 | * You may not alter any existing entry (although adding new ones is | |
101 | * encouraged once assigned by ANSI/INCITS T10 | |
102 | */ | |
4ff36718 | 103 | static const char *const scsi_device_types[] = { |
8a1cdc9c MW |
104 | "Direct-Access ", |
105 | "Sequential-Access", | |
1da177e4 LT |
106 | "Printer ", |
107 | "Processor ", | |
108 | "WORM ", | |
8a1cdc9c | 109 | "CD-ROM ", |
1da177e4 | 110 | "Scanner ", |
8a1cdc9c MW |
111 | "Optical Device ", |
112 | "Medium Changer ", | |
1da177e4 | 113 | "Communications ", |
4ff36718 MW |
114 | "ASC IT8 ", |
115 | "ASC IT8 ", | |
1da177e4 LT |
116 | "RAID ", |
117 | "Enclosure ", | |
8a1cdc9c | 118 | "Direct-Access-RBC", |
4ff36718 MW |
119 | "Optical card ", |
120 | "Bridge controller", | |
121 | "Object storage ", | |
122 | "Automation/Drive ", | |
1da177e4 | 123 | }; |
4ff36718 | 124 | |
eb44820c RL |
125 | /** |
126 | * scsi_device_type - Return 17 char string indicating device type. | |
127 | * @type: type number to look up | |
128 | */ | |
129 | ||
4ff36718 MW |
130 | const char * scsi_device_type(unsigned type) |
131 | { | |
132 | if (type == 0x1e) | |
133 | return "Well-known LUN "; | |
134 | if (type == 0x1f) | |
135 | return "No Device "; | |
80c6e3c0 | 136 | if (type >= ARRAY_SIZE(scsi_device_types)) |
4ff36718 MW |
137 | return "Unknown "; |
138 | return scsi_device_types[type]; | |
139 | } | |
140 | ||
141 | EXPORT_SYMBOL(scsi_device_type); | |
1da177e4 | 142 | |
1da177e4 | 143 | struct scsi_host_cmd_pool { |
e18b890b | 144 | struct kmem_cache *slab; |
1da177e4 LT |
145 | unsigned int users; |
146 | char *name; | |
147 | unsigned int slab_flags; | |
c53033f6 | 148 | gfp_t gfp_mask; |
1da177e4 LT |
149 | }; |
150 | ||
151 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
152 | .name = "scsi_cmd_cache", | |
153 | .slab_flags = SLAB_HWCACHE_ALIGN, | |
154 | }; | |
155 | ||
156 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
157 | .name = "scsi_cmd_cache(DMA)", | |
158 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, | |
159 | .gfp_mask = __GFP_DMA, | |
160 | }; | |
161 | ||
0b950672 | 162 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 163 | |
de25deb1 FT |
164 | static struct kmem_cache *sense_buffer_slab; |
165 | static int sense_buffer_slab_users; | |
166 | ||
eb44820c RL |
167 | /** |
168 | * __scsi_get_command - Allocate a struct scsi_cmnd | |
169 | * @shost: host to transmit command | |
170 | * @gfp_mask: allocation mask | |
171 | * | |
172 | * Description: allocate a struct scsi_cmd from host's slab, recycling from the | |
173 | * host's free_list if necessary. | |
174 | */ | |
b58d9154 | 175 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 LT |
176 | { |
177 | struct scsi_cmnd *cmd; | |
de25deb1 | 178 | unsigned char *buf; |
1da177e4 LT |
179 | |
180 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
181 | gfp_mask | shost->cmd_pool->gfp_mask); | |
182 | ||
183 | if (unlikely(!cmd)) { | |
184 | unsigned long flags; | |
185 | ||
186 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
187 | if (likely(!list_empty(&shost->free_list))) { | |
188 | cmd = list_entry(shost->free_list.next, | |
189 | struct scsi_cmnd, list); | |
190 | list_del_init(&cmd->list); | |
191 | } | |
192 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
de25deb1 FT |
193 | |
194 | if (cmd) { | |
195 | buf = cmd->sense_buffer; | |
196 | memset(cmd, 0, sizeof(*cmd)); | |
197 | cmd->sense_buffer = buf; | |
198 | } | |
199 | } else { | |
200 | buf = kmem_cache_alloc(sense_buffer_slab, __GFP_DMA|gfp_mask); | |
201 | if (likely(buf)) { | |
202 | memset(cmd, 0, sizeof(*cmd)); | |
203 | cmd->sense_buffer = buf; | |
204 | } else { | |
205 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
206 | cmd = NULL; | |
207 | } | |
1da177e4 LT |
208 | } |
209 | ||
210 | return cmd; | |
211 | } | |
b58d9154 | 212 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 | 213 | |
eb44820c RL |
214 | /** |
215 | * scsi_get_command - Allocate and setup a scsi command block | |
216 | * @dev: parent scsi device | |
217 | * @gfp_mask: allocator flags | |
1da177e4 LT |
218 | * |
219 | * Returns: The allocated scsi command structure. | |
220 | */ | |
c53033f6 | 221 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
222 | { |
223 | struct scsi_cmnd *cmd; | |
224 | ||
225 | /* Bail if we can't get a reference to the device */ | |
226 | if (!get_device(&dev->sdev_gendev)) | |
227 | return NULL; | |
228 | ||
229 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
230 | ||
231 | if (likely(cmd != NULL)) { | |
232 | unsigned long flags; | |
233 | ||
1da177e4 | 234 | cmd->device = dev; |
1da177e4 LT |
235 | init_timer(&cmd->eh_timeout); |
236 | INIT_LIST_HEAD(&cmd->list); | |
237 | spin_lock_irqsave(&dev->list_lock, flags); | |
238 | list_add_tail(&cmd->list, &dev->cmd_list); | |
239 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 240 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
241 | } else |
242 | put_device(&dev->sdev_gendev); | |
243 | ||
244 | return cmd; | |
b58d9154 | 245 | } |
1da177e4 LT |
246 | EXPORT_SYMBOL(scsi_get_command); |
247 | ||
eb44820c RL |
248 | /** |
249 | * __scsi_put_command - Free a struct scsi_cmnd | |
250 | * @shost: dev->host | |
251 | * @cmd: Command to free | |
252 | * @dev: parent scsi device | |
253 | */ | |
b58d9154 FT |
254 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
255 | struct device *dev) | |
256 | { | |
257 | unsigned long flags; | |
258 | ||
259 | /* changing locks here, don't need to restore the irq state */ | |
260 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
261 | if (unlikely(list_empty(&shost->free_list))) { | |
262 | list_add(&cmd->list, &shost->free_list); | |
263 | cmd = NULL; | |
264 | } | |
265 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
266 | ||
de25deb1 FT |
267 | if (likely(cmd != NULL)) { |
268 | kmem_cache_free(sense_buffer_slab, cmd->sense_buffer); | |
b58d9154 | 269 | kmem_cache_free(shost->cmd_pool->slab, cmd); |
de25deb1 | 270 | } |
b58d9154 FT |
271 | |
272 | put_device(dev); | |
273 | } | |
274 | EXPORT_SYMBOL(__scsi_put_command); | |
275 | ||
eb44820c RL |
276 | /** |
277 | * scsi_put_command - Free a scsi command block | |
278 | * @cmd: command block to free | |
1da177e4 LT |
279 | * |
280 | * Returns: Nothing. | |
281 | * | |
282 | * Notes: The command must not belong to any lists. | |
283 | */ | |
284 | void scsi_put_command(struct scsi_cmnd *cmd) | |
285 | { | |
286 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 287 | unsigned long flags; |
b58d9154 | 288 | |
1da177e4 LT |
289 | /* serious error if the command hasn't come from a device list */ |
290 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
291 | BUG_ON(list_empty(&cmd->list)); | |
292 | list_del_init(&cmd->list); | |
b58d9154 | 293 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 294 | |
b58d9154 | 295 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
296 | } |
297 | EXPORT_SYMBOL(scsi_put_command); | |
298 | ||
eb44820c RL |
299 | /** |
300 | * scsi_setup_command_freelist - Setup the command freelist for a scsi host. | |
301 | * @shost: host to allocate the freelist for. | |
1da177e4 | 302 | * |
eb44820c RL |
303 | * Description: The command freelist protects against system-wide out of memory |
304 | * deadlock by preallocating one SCSI command structure for each host, so the | |
305 | * system can always write to a swap file on a device associated with that host. | |
1da177e4 LT |
306 | * |
307 | * Returns: Nothing. | |
308 | */ | |
309 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
310 | { | |
311 | struct scsi_host_cmd_pool *pool; | |
312 | struct scsi_cmnd *cmd; | |
de25deb1 | 313 | unsigned char *sense_buffer; |
1da177e4 LT |
314 | |
315 | spin_lock_init(&shost->free_list_lock); | |
316 | INIT_LIST_HEAD(&shost->free_list); | |
317 | ||
318 | /* | |
319 | * Select a command slab for this host and create it if not | |
eb44820c | 320 | * yet existent. |
1da177e4 | 321 | */ |
0b950672 | 322 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
323 | pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool); |
324 | if (!pool->users) { | |
325 | pool->slab = kmem_cache_create(pool->name, | |
326 | sizeof(struct scsi_cmnd), 0, | |
20c2df83 | 327 | pool->slab_flags, NULL); |
1da177e4 LT |
328 | if (!pool->slab) |
329 | goto fail; | |
330 | } | |
331 | ||
332 | pool->users++; | |
333 | shost->cmd_pool = pool; | |
0b950672 | 334 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
335 | |
336 | /* | |
337 | * Get one backup command for this host. | |
338 | */ | |
339 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
340 | GFP_KERNEL | shost->cmd_pool->gfp_mask); | |
341 | if (!cmd) | |
342 | goto fail2; | |
de25deb1 FT |
343 | |
344 | sense_buffer = kmem_cache_alloc(sense_buffer_slab, | |
345 | GFP_KERNEL | __GFP_DMA); | |
346 | if (!sense_buffer) | |
347 | goto destroy_backup; | |
348 | ||
349 | cmd->sense_buffer = sense_buffer; | |
166a7287 | 350 | list_add(&cmd->list, &shost->free_list); |
1da177e4 LT |
351 | return 0; |
352 | ||
de25deb1 FT |
353 | destroy_backup: |
354 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
1da177e4 | 355 | fail2: |
166a7287 | 356 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
357 | if (!--pool->users) |
358 | kmem_cache_destroy(pool->slab); | |
1da177e4 | 359 | fail: |
0b950672 | 360 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 | 361 | return -ENOMEM; |
1da177e4 LT |
362 | } |
363 | ||
eb44820c RL |
364 | /** |
365 | * scsi_destroy_command_freelist - Release the command freelist for a scsi host. | |
366 | * @shost: host whose freelist is going to be destroyed | |
1da177e4 LT |
367 | */ |
368 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
369 | { | |
370 | while (!list_empty(&shost->free_list)) { | |
371 | struct scsi_cmnd *cmd; | |
372 | ||
373 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
374 | list_del_init(&cmd->list); | |
de25deb1 | 375 | kmem_cache_free(sense_buffer_slab, cmd->sense_buffer); |
1da177e4 LT |
376 | kmem_cache_free(shost->cmd_pool->slab, cmd); |
377 | } | |
378 | ||
0b950672 | 379 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
380 | if (!--shost->cmd_pool->users) |
381 | kmem_cache_destroy(shost->cmd_pool->slab); | |
0b950672 | 382 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
383 | } |
384 | ||
de25deb1 FT |
385 | int scsi_setup_command_sense_buffer(struct Scsi_Host *shost) |
386 | { | |
387 | mutex_lock(&host_cmd_pool_mutex); | |
388 | if (!sense_buffer_slab_users) { | |
389 | sense_buffer_slab = kmem_cache_create("scsi_sense_buffer", | |
390 | SCSI_SENSE_BUFFERSIZE, | |
391 | 0, SLAB_CACHE_DMA, NULL); | |
392 | if (!sense_buffer_slab) { | |
393 | mutex_unlock(&host_cmd_pool_mutex); | |
394 | return -ENOMEM; | |
395 | } | |
396 | } | |
397 | sense_buffer_slab_users++; | |
398 | mutex_unlock(&host_cmd_pool_mutex); | |
399 | ||
400 | return 0; | |
401 | } | |
402 | ||
403 | void scsi_destroy_command_sense_buffer(struct Scsi_Host *shost) | |
404 | { | |
405 | mutex_lock(&host_cmd_pool_mutex); | |
406 | if (!--sense_buffer_slab_users) | |
407 | kmem_cache_destroy(sense_buffer_slab); | |
408 | mutex_unlock(&host_cmd_pool_mutex); | |
409 | } | |
410 | ||
1da177e4 LT |
411 | #ifdef CONFIG_SCSI_LOGGING |
412 | void scsi_log_send(struct scsi_cmnd *cmd) | |
413 | { | |
414 | unsigned int level; | |
1da177e4 LT |
415 | |
416 | /* | |
417 | * If ML QUEUE log level is greater than or equal to: | |
418 | * | |
419 | * 1: nothing (match completion) | |
420 | * | |
421 | * 2: log opcode + command of all commands | |
422 | * | |
423 | * 3: same as 2 plus dump cmd address | |
424 | * | |
425 | * 4: same as 3 plus dump extra junk | |
426 | */ | |
427 | if (unlikely(scsi_logging_level)) { | |
428 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
429 | SCSI_LOG_MLQUEUE_BITS); | |
430 | if (level > 1) { | |
a4d04a4c | 431 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
432 | if (level > 2) |
433 | printk("0x%p ", cmd); | |
a4d04a4c | 434 | printk("\n"); |
1da177e4 LT |
435 | scsi_print_command(cmd); |
436 | if (level > 3) { | |
437 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
7b3d9545 | 438 | " queuecommand 0x%p\n", |
a73e45b3 | 439 | scsi_sglist(cmd), scsi_bufflen(cmd), |
a4d04a4c | 440 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
441 | |
442 | } | |
443 | } | |
444 | } | |
445 | } | |
446 | ||
447 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
448 | { | |
449 | unsigned int level; | |
1da177e4 LT |
450 | |
451 | /* | |
452 | * If ML COMPLETE log level is greater than or equal to: | |
453 | * | |
454 | * 1: log disposition, result, opcode + command, and conditionally | |
455 | * sense data for failures or non SUCCESS dispositions. | |
456 | * | |
457 | * 2: same as 1 but for all command completions. | |
458 | * | |
459 | * 3: same as 2 plus dump cmd address | |
460 | * | |
461 | * 4: same as 3 plus dump extra junk | |
462 | */ | |
463 | if (unlikely(scsi_logging_level)) { | |
464 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
465 | SCSI_LOG_MLCOMPLETE_BITS); | |
466 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
467 | (level > 1)) { | |
a4d04a4c | 468 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
469 | if (level > 2) |
470 | printk("0x%p ", cmd); | |
471 | /* | |
472 | * Dump truncated values, so we usually fit within | |
473 | * 80 chars. | |
474 | */ | |
475 | switch (disposition) { | |
476 | case SUCCESS: | |
a4d04a4c | 477 | printk("SUCCESS\n"); |
1da177e4 LT |
478 | break; |
479 | case NEEDS_RETRY: | |
a4d04a4c | 480 | printk("RETRY\n"); |
1da177e4 LT |
481 | break; |
482 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 483 | printk("MLQUEUE\n"); |
1da177e4 LT |
484 | break; |
485 | case FAILED: | |
a4d04a4c | 486 | printk("FAILED\n"); |
1da177e4 LT |
487 | break; |
488 | case TIMEOUT_ERROR: | |
489 | /* | |
490 | * If called via scsi_times_out. | |
491 | */ | |
a4d04a4c | 492 | printk("TIMEOUT\n"); |
1da177e4 LT |
493 | break; |
494 | default: | |
a4d04a4c | 495 | printk("UNKNOWN\n"); |
1da177e4 | 496 | } |
a4d04a4c | 497 | scsi_print_result(cmd); |
1da177e4 | 498 | scsi_print_command(cmd); |
a4d04a4c | 499 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 500 | scsi_print_sense("", cmd); |
a4d04a4c MP |
501 | if (level > 3) |
502 | scmd_printk(KERN_INFO, cmd, | |
503 | "scsi host busy %d failed %d\n", | |
504 | cmd->device->host->host_busy, | |
505 | cmd->device->host->host_failed); | |
1da177e4 LT |
506 | } |
507 | } | |
508 | } | |
509 | #endif | |
510 | ||
eb44820c RL |
511 | /** |
512 | * scsi_cmd_get_serial - Assign a serial number to a command | |
513 | * @host: the scsi host | |
514 | * @cmd: command to assign serial number to | |
515 | * | |
516 | * Description: a serial number identifies a request for error recovery | |
1da177e4 LT |
517 | * and debugging purposes. Protected by the Host_Lock of host. |
518 | */ | |
519 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
520 | { | |
521 | cmd->serial_number = host->cmd_serial_number++; | |
522 | if (cmd->serial_number == 0) | |
523 | cmd->serial_number = host->cmd_serial_number++; | |
1da177e4 LT |
524 | } |
525 | ||
eb44820c RL |
526 | /** |
527 | * scsi_dispatch_command - Dispatch a command to the low-level driver. | |
528 | * @cmd: command block we are dispatching. | |
1da177e4 | 529 | * |
eb44820c RL |
530 | * Return: nonzero return request was rejected and device's queue needs to be |
531 | * plugged. | |
1da177e4 LT |
532 | */ |
533 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
534 | { | |
535 | struct Scsi_Host *host = cmd->device->host; | |
536 | unsigned long flags = 0; | |
537 | unsigned long timeout; | |
538 | int rtn = 0; | |
539 | ||
540 | /* check if the device is still usable */ | |
541 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
542 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
543 | * returns an immediate error upwards, and signals | |
544 | * that the device is no longer present */ | |
545 | cmd->result = DID_NO_CONNECT << 16; | |
546 | atomic_inc(&cmd->device->iorequest_cnt); | |
69b52893 | 547 | __scsi_done(cmd); |
1da177e4 LT |
548 | /* return 0 (because the command has been processed) */ |
549 | goto out; | |
550 | } | |
551 | ||
552 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
553 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
554 | /* | |
555 | * in SDEV_BLOCK, the command is just put back on the device | |
556 | * queue. The suspend state has already blocked the queue so | |
557 | * future requests should not occur until the device | |
558 | * transitions out of the suspend state. | |
559 | */ | |
560 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
561 | ||
562 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
563 | ||
564 | /* | |
565 | * NOTE: rtn is still zero here because we don't need the | |
566 | * queue to be plugged on return (it's already stopped) | |
567 | */ | |
568 | goto out; | |
569 | } | |
570 | ||
571 | /* | |
572 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
573 | */ | |
4d7db04a JB |
574 | if (cmd->device->scsi_level <= SCSI_2 && |
575 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
576 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
577 | (cmd->device->lun << 5 & 0xe0); | |
578 | } | |
579 | ||
580 | /* | |
581 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
582 | * we can avoid the drive not being ready. | |
583 | */ | |
584 | timeout = host->last_reset + MIN_RESET_DELAY; | |
585 | ||
586 | if (host->resetting && time_before(jiffies, timeout)) { | |
587 | int ticks_remaining = timeout - jiffies; | |
588 | /* | |
589 | * NOTE: This may be executed from within an interrupt | |
590 | * handler! This is bad, but for now, it'll do. The irq | |
591 | * level of the interrupt handler has been masked out by the | |
592 | * platform dependent interrupt handling code already, so the | |
593 | * sti() here will not cause another call to the SCSI host's | |
594 | * interrupt handler (assuming there is one irq-level per | |
595 | * host). | |
596 | */ | |
597 | while (--ticks_remaining >= 0) | |
598 | mdelay(1 + 999 / HZ); | |
599 | host->resetting = 0; | |
600 | } | |
601 | ||
602 | /* | |
603 | * AK: unlikely race here: for some reason the timer could | |
604 | * expire before the serial number is set up below. | |
605 | */ | |
606 | scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out); | |
607 | ||
608 | scsi_log_send(cmd); | |
609 | ||
610 | /* | |
611 | * We will use a queued command if possible, otherwise we will | |
612 | * emulate the queuing and calling of completion function ourselves. | |
613 | */ | |
1da177e4 LT |
614 | atomic_inc(&cmd->device->iorequest_cnt); |
615 | ||
616 | /* | |
617 | * Before we queue this command, check if the command | |
618 | * length exceeds what the host adapter can handle. | |
619 | */ | |
620 | if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) { | |
621 | SCSI_LOG_MLQUEUE(3, | |
622 | printk("queuecommand : command too long.\n")); | |
623 | cmd->result = (DID_ABORT << 16); | |
624 | ||
625 | scsi_done(cmd); | |
626 | goto out; | |
627 | } | |
628 | ||
629 | spin_lock_irqsave(host->host_lock, flags); | |
630 | scsi_cmd_get_serial(host, cmd); | |
631 | ||
d2c9d9ea | 632 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
633 | cmd->result = (DID_NO_CONNECT << 16); |
634 | scsi_done(cmd); | |
635 | } else { | |
636 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
637 | } | |
638 | spin_unlock_irqrestore(host->host_lock, flags); | |
639 | if (rtn) { | |
d8c37e7b TH |
640 | if (scsi_delete_timer(cmd)) { |
641 | atomic_inc(&cmd->device->iodone_cnt); | |
642 | scsi_queue_insert(cmd, | |
643 | (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? | |
644 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
645 | } | |
1da177e4 LT |
646 | SCSI_LOG_MLQUEUE(3, |
647 | printk("queuecommand : request rejected\n")); | |
648 | } | |
649 | ||
650 | out: | |
651 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
652 | return rtn; | |
653 | } | |
654 | ||
89f48c4d LT |
655 | /** |
656 | * scsi_req_abort_cmd -- Request command recovery for the specified command | |
eb44820c | 657 | * @cmd: pointer to the SCSI command of interest |
89f48c4d LT |
658 | * |
659 | * This function requests that SCSI Core start recovery for the | |
660 | * command by deleting the timer and adding the command to the eh | |
661 | * queue. It can be called by either LLDDs or SCSI Core. LLDDs who | |
662 | * implement their own error recovery MAY ignore the timeout event if | |
663 | * they generated scsi_req_abort_cmd. | |
664 | */ | |
665 | void scsi_req_abort_cmd(struct scsi_cmnd *cmd) | |
666 | { | |
667 | if (!scsi_delete_timer(cmd)) | |
668 | return; | |
669 | scsi_times_out(cmd); | |
670 | } | |
671 | EXPORT_SYMBOL(scsi_req_abort_cmd); | |
672 | ||
1da177e4 LT |
673 | /** |
674 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
675 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
676 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
677 | * | |
eb44820c RL |
678 | * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
679 | * which regains ownership of the SCSI command (de facto) from a LLDD, and | |
680 | * enqueues the command to the done queue for further processing. | |
1da177e4 LT |
681 | * |
682 | * This is the producer of the done queue who enqueues at the tail. | |
683 | * | |
684 | * This function is interrupt context safe. | |
685 | */ | |
52c1da39 | 686 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 LT |
687 | { |
688 | /* | |
eb44820c | 689 | * We don't have to worry about this one timing out anymore. |
1da177e4 LT |
690 | * If we are unable to remove the timer, then the command |
691 | * has already timed out. In which case, we have no choice but to | |
692 | * let the timeout function run, as we have no idea where in fact | |
693 | * that function could really be. It might be on another processor, | |
694 | * etc, etc. | |
695 | */ | |
696 | if (!scsi_delete_timer(cmd)) | |
697 | return; | |
698 | __scsi_done(cmd); | |
699 | } | |
700 | ||
701 | /* Private entry to scsi_done() to complete a command when the timer | |
702 | * isn't running --- used by scsi_times_out */ | |
703 | void __scsi_done(struct scsi_cmnd *cmd) | |
704 | { | |
1aea6434 | 705 | struct request *rq = cmd->request; |
1da177e4 LT |
706 | |
707 | /* | |
708 | * Set the serial numbers back to zero | |
709 | */ | |
710 | cmd->serial_number = 0; | |
1da177e4 LT |
711 | |
712 | atomic_inc(&cmd->device->iodone_cnt); | |
713 | if (cmd->result) | |
714 | atomic_inc(&cmd->device->ioerr_cnt); | |
715 | ||
1aea6434 JA |
716 | BUG_ON(!rq); |
717 | ||
1da177e4 | 718 | /* |
1aea6434 JA |
719 | * The uptodate/nbytes values don't matter, as we allow partial |
720 | * completes and thus will check this in the softirq callback | |
1da177e4 | 721 | */ |
1aea6434 JA |
722 | rq->completion_data = cmd; |
723 | blk_complete_request(rq); | |
1da177e4 LT |
724 | } |
725 | ||
7b3d9545 LT |
726 | /* Move this to a header if it becomes more generally useful */ |
727 | static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) | |
728 | { | |
729 | return *(struct scsi_driver **)cmd->request->rq_disk->private_data; | |
730 | } | |
731 | ||
eb44820c RL |
732 | /** |
733 | * scsi_finish_command - cleanup and pass command back to upper layer | |
734 | * @cmd: the command | |
1da177e4 | 735 | * |
eb44820c | 736 | * Description: Pass command off to upper layer for finishing of I/O |
1da177e4 LT |
737 | * request, waking processes that are waiting on results, |
738 | * etc. | |
739 | */ | |
740 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
741 | { | |
742 | struct scsi_device *sdev = cmd->device; | |
743 | struct Scsi_Host *shost = sdev->host; | |
7b3d9545 LT |
744 | struct scsi_driver *drv; |
745 | unsigned int good_bytes; | |
1da177e4 LT |
746 | |
747 | scsi_device_unbusy(sdev); | |
748 | ||
749 | /* | |
750 | * Clear the flags which say that the device/host is no longer | |
751 | * capable of accepting new commands. These are set in scsi_queue.c | |
752 | * for both the queue full condition on a device, and for a | |
753 | * host full condition on the host. | |
754 | * | |
755 | * XXX(hch): What about locking? | |
756 | */ | |
757 | shost->host_blocked = 0; | |
758 | sdev->device_blocked = 0; | |
759 | ||
760 | /* | |
761 | * If we have valid sense information, then some kind of recovery | |
762 | * must have taken place. Make a note of this. | |
763 | */ | |
764 | if (SCSI_SENSE_VALID(cmd)) | |
765 | cmd->result |= (DRIVER_SENSE << 24); | |
766 | ||
3bf743e7 JG |
767 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
768 | "Notifying upper driver of completion " | |
769 | "(result %x)\n", cmd->result)); | |
1da177e4 | 770 | |
7b3d9545 LT |
771 | good_bytes = cmd->request_bufflen; |
772 | if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { | |
773 | drv = scsi_cmd_to_driver(cmd); | |
774 | if (drv->done) | |
775 | good_bytes = drv->done(cmd); | |
776 | } | |
777 | scsi_io_completion(cmd, good_bytes); | |
1da177e4 LT |
778 | } |
779 | EXPORT_SYMBOL(scsi_finish_command); | |
780 | ||
eb44820c RL |
781 | /** |
782 | * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth | |
783 | * @sdev: SCSI Device in question | |
784 | * @tagged: Do we use tagged queueing (non-0) or do we treat | |
785 | * this device as an untagged device (0) | |
786 | * @tags: Number of tags allowed if tagged queueing enabled, | |
787 | * or number of commands the low level driver can | |
788 | * queue up in non-tagged mode (as per cmd_per_lun). | |
1da177e4 LT |
789 | * |
790 | * Returns: Nothing | |
791 | * | |
792 | * Lock Status: None held on entry | |
793 | * | |
794 | * Notes: Low level drivers may call this at any time and we will do | |
795 | * the right thing depending on whether or not the device is | |
796 | * currently active and whether or not it even has the | |
797 | * command blocks built yet. | |
798 | */ | |
799 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
800 | { | |
801 | unsigned long flags; | |
802 | ||
803 | /* | |
804 | * refuse to set tagged depth to an unworkable size | |
805 | */ | |
806 | if (tags <= 0) | |
807 | return; | |
808 | ||
809 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
810 | ||
eb44820c RL |
811 | /* Check to see if the queue is managed by the block layer. |
812 | * If it is, and we fail to adjust the depth, exit. */ | |
1da177e4 LT |
813 | if (blk_queue_tagged(sdev->request_queue) && |
814 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
815 | goto out; | |
816 | ||
817 | sdev->queue_depth = tags; | |
818 | switch (tagged) { | |
819 | case MSG_ORDERED_TAG: | |
820 | sdev->ordered_tags = 1; | |
821 | sdev->simple_tags = 1; | |
822 | break; | |
823 | case MSG_SIMPLE_TAG: | |
824 | sdev->ordered_tags = 0; | |
825 | sdev->simple_tags = 1; | |
826 | break; | |
827 | default: | |
9ccfc756 JB |
828 | sdev_printk(KERN_WARNING, sdev, |
829 | "scsi_adjust_queue_depth, bad queue type, " | |
830 | "disabled\n"); | |
1da177e4 LT |
831 | case 0: |
832 | sdev->ordered_tags = sdev->simple_tags = 0; | |
833 | sdev->queue_depth = tags; | |
834 | break; | |
835 | } | |
836 | out: | |
837 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
838 | } | |
839 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
840 | ||
eb44820c RL |
841 | /** |
842 | * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth | |
843 | * @sdev: SCSI Device in question | |
844 | * @depth: Current number of outstanding SCSI commands on this device, | |
845 | * not counting the one returned as QUEUE_FULL. | |
1da177e4 | 846 | * |
eb44820c | 847 | * Description: This function will track successive QUEUE_FULL events on a |
1da177e4 LT |
848 | * specific SCSI device to determine if and when there is a |
849 | * need to adjust the queue depth on the device. | |
850 | * | |
eb44820c | 851 | * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
1da177e4 LT |
852 | * -1 - Drop back to untagged operation using host->cmd_per_lun |
853 | * as the untagged command depth | |
854 | * | |
855 | * Lock Status: None held on entry | |
856 | * | |
857 | * Notes: Low level drivers may call this at any time and we will do | |
858 | * "The Right Thing." We are interrupt context safe. | |
859 | */ | |
860 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
861 | { | |
862 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
863 | return 0; | |
864 | ||
865 | sdev->last_queue_full_time = (jiffies >> 4); | |
866 | if (sdev->last_queue_full_depth != depth) { | |
867 | sdev->last_queue_full_count = 1; | |
868 | sdev->last_queue_full_depth = depth; | |
869 | } else { | |
870 | sdev->last_queue_full_count++; | |
871 | } | |
872 | ||
873 | if (sdev->last_queue_full_count <= 10) | |
874 | return 0; | |
875 | if (sdev->last_queue_full_depth < 8) { | |
876 | /* Drop back to untagged */ | |
877 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
878 | return -1; | |
879 | } | |
880 | ||
881 | if (sdev->ordered_tags) | |
882 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
883 | else | |
884 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
885 | return depth; | |
886 | } | |
887 | EXPORT_SYMBOL(scsi_track_queue_full); | |
888 | ||
889 | /** | |
eb44820c | 890 | * scsi_device_get - get an additional reference to a scsi_device |
1da177e4 LT |
891 | * @sdev: device to get a reference to |
892 | * | |
eb44820c | 893 | * Description: Gets a reference to the scsi_device and increments the use count |
1da177e4 LT |
894 | * of the underlying LLDD module. You must hold host_lock of the |
895 | * parent Scsi_Host or already have a reference when calling this. | |
896 | */ | |
897 | int scsi_device_get(struct scsi_device *sdev) | |
898 | { | |
85b6c720 | 899 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
900 | return -ENXIO; |
901 | if (!get_device(&sdev->sdev_gendev)) | |
902 | return -ENXIO; | |
85b6c720 JB |
903 | /* We can fail this if we're doing SCSI operations |
904 | * from module exit (like cache flush) */ | |
905 | try_module_get(sdev->host->hostt->module); | |
906 | ||
1da177e4 LT |
907 | return 0; |
908 | } | |
909 | EXPORT_SYMBOL(scsi_device_get); | |
910 | ||
911 | /** | |
912 | * scsi_device_put - release a reference to a scsi_device | |
913 | * @sdev: device to release a reference on. | |
914 | * | |
eb44820c RL |
915 | * Description: Release a reference to the scsi_device and decrements the use |
916 | * count of the underlying LLDD module. The device is freed once the last | |
1da177e4 LT |
917 | * user vanishes. |
918 | */ | |
919 | void scsi_device_put(struct scsi_device *sdev) | |
920 | { | |
504fb37a | 921 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
922 | struct module *module = sdev->host->hostt->module; |
923 | ||
85b6c720 JB |
924 | /* The module refcount will be zero if scsi_device_get() |
925 | * was called from a module removal routine */ | |
f479ab87 JB |
926 | if (module && module_refcount(module) != 0) |
927 | module_put(module); | |
a506b44b | 928 | #endif |
1da177e4 LT |
929 | put_device(&sdev->sdev_gendev); |
930 | } | |
931 | EXPORT_SYMBOL(scsi_device_put); | |
932 | ||
eb44820c | 933 | /* helper for shost_for_each_device, see that for documentation */ |
1da177e4 LT |
934 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
935 | struct scsi_device *prev) | |
936 | { | |
937 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
938 | struct scsi_device *next = NULL; | |
939 | unsigned long flags; | |
940 | ||
941 | spin_lock_irqsave(shost->host_lock, flags); | |
942 | while (list->next != &shost->__devices) { | |
943 | next = list_entry(list->next, struct scsi_device, siblings); | |
944 | /* skip devices that we can't get a reference to */ | |
945 | if (!scsi_device_get(next)) | |
946 | break; | |
947 | next = NULL; | |
948 | list = list->next; | |
949 | } | |
950 | spin_unlock_irqrestore(shost->host_lock, flags); | |
951 | ||
952 | if (prev) | |
953 | scsi_device_put(prev); | |
954 | return next; | |
955 | } | |
956 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
957 | ||
958 | /** | |
959 | * starget_for_each_device - helper to walk all devices of a target | |
960 | * @starget: target whose devices we want to iterate over. | |
eb44820c RL |
961 | * @data: Opaque passed to each function call. |
962 | * @fn: Function to call on each device | |
1da177e4 | 963 | * |
522939d4 | 964 | * This traverses over each device of @starget. The devices have |
1da177e4 LT |
965 | * a reference that must be released by scsi_host_put when breaking |
966 | * out of the loop. | |
967 | */ | |
522939d4 | 968 | void starget_for_each_device(struct scsi_target *starget, void *data, |
1da177e4 LT |
969 | void (*fn)(struct scsi_device *, void *)) |
970 | { | |
971 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
972 | struct scsi_device *sdev; | |
973 | ||
974 | shost_for_each_device(sdev, shost) { | |
975 | if ((sdev->channel == starget->channel) && | |
976 | (sdev->id == starget->id)) | |
977 | fn(sdev, data); | |
978 | } | |
979 | } | |
980 | EXPORT_SYMBOL(starget_for_each_device); | |
981 | ||
522939d4 MR |
982 | /** |
983 | * __starget_for_each_device - helper to walk all devices of a target | |
984 | * (UNLOCKED) | |
985 | * @starget: target whose devices we want to iterate over. | |
986 | * | |
987 | * This traverses over each device of @starget. It does _not_ | |
988 | * take a reference on the scsi_device, so the whole loop must be | |
989 | * protected by shost->host_lock. | |
990 | * | |
991 | * Note: The only reason why drivers would want to use this is because | |
992 | * they need to access the device list in irq context. Otherwise you | |
993 | * really want to use starget_for_each_device instead. | |
994 | **/ | |
995 | void __starget_for_each_device(struct scsi_target *starget, void *data, | |
996 | void (*fn)(struct scsi_device *, void *)) | |
997 | { | |
998 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
999 | struct scsi_device *sdev; | |
1000 | ||
1001 | __shost_for_each_device(sdev, shost) { | |
1002 | if ((sdev->channel == starget->channel) && | |
1003 | (sdev->id == starget->id)) | |
1004 | fn(sdev, data); | |
1005 | } | |
1006 | } | |
1007 | EXPORT_SYMBOL(__starget_for_each_device); | |
1008 | ||
1da177e4 LT |
1009 | /** |
1010 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
1011 | * @starget: SCSI target pointer | |
1012 | * @lun: SCSI Logical Unit Number | |
1013 | * | |
eb44820c RL |
1014 | * Description: Looks up the scsi_device with the specified @lun for a given |
1015 | * @starget. The returned scsi_device does not have an additional | |
1da177e4 LT |
1016 | * reference. You must hold the host's host_lock over this call and |
1017 | * any access to the returned scsi_device. | |
1018 | * | |
dc8875e1 | 1019 | * Note: The only reason why drivers should use this is because |
eb44820c | 1020 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1021 | * really want to use scsi_device_lookup_by_target instead. |
1022 | **/ | |
1023 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
1024 | uint lun) | |
1025 | { | |
1026 | struct scsi_device *sdev; | |
1027 | ||
1028 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
1029 | if (sdev->lun ==lun) | |
1030 | return sdev; | |
1031 | } | |
1032 | ||
1033 | return NULL; | |
1034 | } | |
1035 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
1036 | ||
1037 | /** | |
1038 | * scsi_device_lookup_by_target - find a device given the target | |
1039 | * @starget: SCSI target pointer | |
1040 | * @lun: SCSI Logical Unit Number | |
1041 | * | |
eb44820c RL |
1042 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1043 | * for a given host. The returned scsi_device has an additional reference that | |
1044 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1045 | **/ |
1046 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
1047 | uint lun) | |
1048 | { | |
1049 | struct scsi_device *sdev; | |
1050 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
1051 | unsigned long flags; | |
1052 | ||
1053 | spin_lock_irqsave(shost->host_lock, flags); | |
1054 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
1055 | if (sdev && scsi_device_get(sdev)) | |
1056 | sdev = NULL; | |
1057 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1058 | ||
1059 | return sdev; | |
1060 | } | |
1061 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
1062 | ||
1063 | /** | |
eb44820c | 1064 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
1da177e4 LT |
1065 | * @shost: SCSI host pointer |
1066 | * @channel: SCSI channel (zero if only one channel) | |
eb44820c | 1067 | * @id: SCSI target number (physical unit number) |
1da177e4 LT |
1068 | * @lun: SCSI Logical Unit Number |
1069 | * | |
eb44820c RL |
1070 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1071 | * for a given host. The returned scsi_device does not have an additional | |
1072 | * reference. You must hold the host's host_lock over this call and any access | |
1073 | * to the returned scsi_device. | |
1da177e4 LT |
1074 | * |
1075 | * Note: The only reason why drivers would want to use this is because | |
eb44820c | 1076 | * they need to access the device list in irq context. Otherwise you |
1da177e4 LT |
1077 | * really want to use scsi_device_lookup instead. |
1078 | **/ | |
1079 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
1080 | uint channel, uint id, uint lun) | |
1081 | { | |
1082 | struct scsi_device *sdev; | |
1083 | ||
1084 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
1085 | if (sdev->channel == channel && sdev->id == id && | |
1086 | sdev->lun ==lun) | |
1087 | return sdev; | |
1088 | } | |
1089 | ||
1090 | return NULL; | |
1091 | } | |
1092 | EXPORT_SYMBOL(__scsi_device_lookup); | |
1093 | ||
1094 | /** | |
1095 | * scsi_device_lookup - find a device given the host | |
1096 | * @shost: SCSI host pointer | |
1097 | * @channel: SCSI channel (zero if only one channel) | |
1098 | * @id: SCSI target number (physical unit number) | |
1099 | * @lun: SCSI Logical Unit Number | |
1100 | * | |
eb44820c RL |
1101 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
1102 | * for a given host. The returned scsi_device has an additional reference that | |
1103 | * needs to be released with scsi_device_put once you're done with it. | |
1da177e4 LT |
1104 | **/ |
1105 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1106 | uint channel, uint id, uint lun) | |
1107 | { | |
1108 | struct scsi_device *sdev; | |
1109 | unsigned long flags; | |
1110 | ||
1111 | spin_lock_irqsave(shost->host_lock, flags); | |
1112 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1113 | if (sdev && scsi_device_get(sdev)) | |
1114 | sdev = NULL; | |
1115 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1116 | ||
1117 | return sdev; | |
1118 | } | |
1119 | EXPORT_SYMBOL(scsi_device_lookup); | |
1120 | ||
1da177e4 LT |
1121 | MODULE_DESCRIPTION("SCSI core"); |
1122 | MODULE_LICENSE("GPL"); | |
1123 | ||
1124 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1125 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1126 | ||
1127 | static int __init init_scsi(void) | |
1128 | { | |
9bf09c23 | 1129 | int error; |
1da177e4 LT |
1130 | |
1131 | error = scsi_init_queue(); | |
1132 | if (error) | |
1133 | return error; | |
1134 | error = scsi_init_procfs(); | |
1135 | if (error) | |
1136 | goto cleanup_queue; | |
1137 | error = scsi_init_devinfo(); | |
1138 | if (error) | |
1139 | goto cleanup_procfs; | |
1140 | error = scsi_init_hosts(); | |
1141 | if (error) | |
1142 | goto cleanup_devlist; | |
1143 | error = scsi_init_sysctl(); | |
1144 | if (error) | |
1145 | goto cleanup_hosts; | |
1146 | error = scsi_sysfs_register(); | |
1147 | if (error) | |
1148 | goto cleanup_sysctl; | |
1149 | ||
84314fd4 JS |
1150 | scsi_netlink_init(); |
1151 | ||
1da177e4 LT |
1152 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1153 | return 0; | |
1154 | ||
1155 | cleanup_sysctl: | |
1156 | scsi_exit_sysctl(); | |
1157 | cleanup_hosts: | |
1158 | scsi_exit_hosts(); | |
1159 | cleanup_devlist: | |
1160 | scsi_exit_devinfo(); | |
1161 | cleanup_procfs: | |
1162 | scsi_exit_procfs(); | |
1163 | cleanup_queue: | |
1164 | scsi_exit_queue(); | |
1165 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1166 | -error); | |
1167 | return error; | |
1168 | } | |
1169 | ||
1170 | static void __exit exit_scsi(void) | |
1171 | { | |
84314fd4 | 1172 | scsi_netlink_exit(); |
1da177e4 LT |
1173 | scsi_sysfs_unregister(); |
1174 | scsi_exit_sysctl(); | |
1175 | scsi_exit_hosts(); | |
1176 | scsi_exit_devinfo(); | |
1da177e4 LT |
1177 | scsi_exit_procfs(); |
1178 | scsi_exit_queue(); | |
1da177e4 LT |
1179 | } |
1180 | ||
1181 | subsys_initcall(init_scsi); | |
1182 | module_exit(exit_scsi); |