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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> | |
62 | #include <scsi/scsi_eh.h> | |
63 | #include <scsi/scsi_host.h> | |
64 | #include <scsi/scsi_tcq.h> | |
1da177e4 LT |
65 | |
66 | #include "scsi_priv.h" | |
67 | #include "scsi_logging.h" | |
68 | ||
52c1da39 | 69 | static void scsi_done(struct scsi_cmnd *cmd); |
1da177e4 LT |
70 | |
71 | /* | |
72 | * Definitions and constants. | |
73 | */ | |
74 | ||
75 | #define MIN_RESET_DELAY (2*HZ) | |
76 | ||
77 | /* Do not call reset on error if we just did a reset within 15 sec. */ | |
78 | #define MIN_RESET_PERIOD (15*HZ) | |
79 | ||
80 | /* | |
81 | * Macro to determine the size of SCSI command. This macro takes vendor | |
82 | * unique commands into account. SCSI commands in groups 6 and 7 are | |
83 | * vendor unique and we will depend upon the command length being | |
84 | * supplied correctly in cmd_len. | |
85 | */ | |
86 | #define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \ | |
87 | COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len) | |
88 | ||
89 | /* | |
90 | * Note - the initial logging level can be set here to log events at boot time. | |
91 | * After the system is up, you may enable logging via the /proc interface. | |
92 | */ | |
93 | unsigned int scsi_logging_level; | |
94 | #if defined(CONFIG_SCSI_LOGGING) | |
95 | EXPORT_SYMBOL(scsi_logging_level); | |
96 | #endif | |
97 | ||
8a1cdc9c MW |
98 | /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. |
99 | * You may not alter any existing entry (although adding new ones is | |
100 | * encouraged once assigned by ANSI/INCITS T10 | |
101 | */ | |
4ff36718 | 102 | static const char *const scsi_device_types[] = { |
8a1cdc9c MW |
103 | "Direct-Access ", |
104 | "Sequential-Access", | |
1da177e4 LT |
105 | "Printer ", |
106 | "Processor ", | |
107 | "WORM ", | |
8a1cdc9c | 108 | "CD-ROM ", |
1da177e4 | 109 | "Scanner ", |
8a1cdc9c MW |
110 | "Optical Device ", |
111 | "Medium Changer ", | |
1da177e4 | 112 | "Communications ", |
4ff36718 MW |
113 | "ASC IT8 ", |
114 | "ASC IT8 ", | |
1da177e4 LT |
115 | "RAID ", |
116 | "Enclosure ", | |
8a1cdc9c | 117 | "Direct-Access-RBC", |
4ff36718 MW |
118 | "Optical card ", |
119 | "Bridge controller", | |
120 | "Object storage ", | |
121 | "Automation/Drive ", | |
1da177e4 | 122 | }; |
4ff36718 MW |
123 | |
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 { |
e18b890b | 138 | struct kmem_cache *slab; |
1da177e4 LT |
139 | unsigned int users; |
140 | char *name; | |
141 | unsigned int slab_flags; | |
c53033f6 | 142 | gfp_t gfp_mask; |
1da177e4 LT |
143 | }; |
144 | ||
145 | static struct scsi_host_cmd_pool scsi_cmd_pool = { | |
146 | .name = "scsi_cmd_cache", | |
147 | .slab_flags = SLAB_HWCACHE_ALIGN, | |
148 | }; | |
149 | ||
150 | static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { | |
151 | .name = "scsi_cmd_cache(DMA)", | |
152 | .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, | |
153 | .gfp_mask = __GFP_DMA, | |
154 | }; | |
155 | ||
0b950672 | 156 | static DEFINE_MUTEX(host_cmd_pool_mutex); |
1da177e4 | 157 | |
b58d9154 | 158 | struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
1da177e4 LT |
159 | { |
160 | struct scsi_cmnd *cmd; | |
161 | ||
162 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
163 | gfp_mask | shost->cmd_pool->gfp_mask); | |
164 | ||
165 | if (unlikely(!cmd)) { | |
166 | unsigned long flags; | |
167 | ||
168 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
169 | if (likely(!list_empty(&shost->free_list))) { | |
170 | cmd = list_entry(shost->free_list.next, | |
171 | struct scsi_cmnd, list); | |
172 | list_del_init(&cmd->list); | |
173 | } | |
174 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
175 | } | |
176 | ||
177 | return cmd; | |
178 | } | |
b58d9154 | 179 | EXPORT_SYMBOL_GPL(__scsi_get_command); |
1da177e4 LT |
180 | |
181 | /* | |
182 | * Function: scsi_get_command() | |
183 | * | |
184 | * Purpose: Allocate and setup a scsi command block | |
185 | * | |
186 | * Arguments: dev - parent scsi device | |
187 | * gfp_mask- allocator flags | |
188 | * | |
189 | * Returns: The allocated scsi command structure. | |
190 | */ | |
c53033f6 | 191 | struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
1da177e4 LT |
192 | { |
193 | struct scsi_cmnd *cmd; | |
194 | ||
195 | /* Bail if we can't get a reference to the device */ | |
196 | if (!get_device(&dev->sdev_gendev)) | |
197 | return NULL; | |
198 | ||
199 | cmd = __scsi_get_command(dev->host, gfp_mask); | |
200 | ||
201 | if (likely(cmd != NULL)) { | |
202 | unsigned long flags; | |
203 | ||
204 | memset(cmd, 0, sizeof(*cmd)); | |
205 | cmd->device = dev; | |
1da177e4 LT |
206 | init_timer(&cmd->eh_timeout); |
207 | INIT_LIST_HEAD(&cmd->list); | |
208 | spin_lock_irqsave(&dev->list_lock, flags); | |
209 | list_add_tail(&cmd->list, &dev->cmd_list); | |
210 | spin_unlock_irqrestore(&dev->list_lock, flags); | |
79e448bf | 211 | cmd->jiffies_at_alloc = jiffies; |
1da177e4 LT |
212 | } else |
213 | put_device(&dev->sdev_gendev); | |
214 | ||
215 | return cmd; | |
b58d9154 | 216 | } |
1da177e4 LT |
217 | EXPORT_SYMBOL(scsi_get_command); |
218 | ||
b58d9154 FT |
219 | void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, |
220 | struct device *dev) | |
221 | { | |
222 | unsigned long flags; | |
223 | ||
224 | /* changing locks here, don't need to restore the irq state */ | |
225 | spin_lock_irqsave(&shost->free_list_lock, flags); | |
226 | if (unlikely(list_empty(&shost->free_list))) { | |
227 | list_add(&cmd->list, &shost->free_list); | |
228 | cmd = NULL; | |
229 | } | |
230 | spin_unlock_irqrestore(&shost->free_list_lock, flags); | |
231 | ||
232 | if (likely(cmd != NULL)) | |
233 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
234 | ||
235 | put_device(dev); | |
236 | } | |
237 | EXPORT_SYMBOL(__scsi_put_command); | |
238 | ||
1da177e4 LT |
239 | /* |
240 | * Function: scsi_put_command() | |
241 | * | |
242 | * Purpose: Free a scsi command block | |
243 | * | |
244 | * Arguments: cmd - command block to free | |
245 | * | |
246 | * Returns: Nothing. | |
247 | * | |
248 | * Notes: The command must not belong to any lists. | |
249 | */ | |
250 | void scsi_put_command(struct scsi_cmnd *cmd) | |
251 | { | |
252 | struct scsi_device *sdev = cmd->device; | |
1da177e4 | 253 | unsigned long flags; |
b58d9154 | 254 | |
1da177e4 LT |
255 | /* serious error if the command hasn't come from a device list */ |
256 | spin_lock_irqsave(&cmd->device->list_lock, flags); | |
257 | BUG_ON(list_empty(&cmd->list)); | |
258 | list_del_init(&cmd->list); | |
b58d9154 | 259 | spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
1da177e4 | 260 | |
b58d9154 | 261 | __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev); |
1da177e4 LT |
262 | } |
263 | EXPORT_SYMBOL(scsi_put_command); | |
264 | ||
265 | /* | |
266 | * Function: scsi_setup_command_freelist() | |
267 | * | |
268 | * Purpose: Setup the command freelist for a scsi host. | |
269 | * | |
270 | * Arguments: shost - host to allocate the freelist for. | |
271 | * | |
272 | * Returns: Nothing. | |
273 | */ | |
274 | int scsi_setup_command_freelist(struct Scsi_Host *shost) | |
275 | { | |
276 | struct scsi_host_cmd_pool *pool; | |
277 | struct scsi_cmnd *cmd; | |
278 | ||
279 | spin_lock_init(&shost->free_list_lock); | |
280 | INIT_LIST_HEAD(&shost->free_list); | |
281 | ||
282 | /* | |
283 | * Select a command slab for this host and create it if not | |
284 | * yet existant. | |
285 | */ | |
0b950672 | 286 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
287 | pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool); |
288 | if (!pool->users) { | |
289 | pool->slab = kmem_cache_create(pool->name, | |
290 | sizeof(struct scsi_cmnd), 0, | |
291 | pool->slab_flags, NULL, NULL); | |
292 | if (!pool->slab) | |
293 | goto fail; | |
294 | } | |
295 | ||
296 | pool->users++; | |
297 | shost->cmd_pool = pool; | |
0b950672 | 298 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
299 | |
300 | /* | |
301 | * Get one backup command for this host. | |
302 | */ | |
303 | cmd = kmem_cache_alloc(shost->cmd_pool->slab, | |
304 | GFP_KERNEL | shost->cmd_pool->gfp_mask); | |
305 | if (!cmd) | |
306 | goto fail2; | |
307 | list_add(&cmd->list, &shost->free_list); | |
308 | return 0; | |
309 | ||
310 | fail2: | |
311 | if (!--pool->users) | |
312 | kmem_cache_destroy(pool->slab); | |
313 | return -ENOMEM; | |
314 | fail: | |
0b950672 | 315 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
316 | return -ENOMEM; |
317 | ||
318 | } | |
319 | ||
320 | /* | |
321 | * Function: scsi_destroy_command_freelist() | |
322 | * | |
323 | * Purpose: Release the command freelist for a scsi host. | |
324 | * | |
325 | * Arguments: shost - host that's freelist is going to be destroyed | |
326 | */ | |
327 | void scsi_destroy_command_freelist(struct Scsi_Host *shost) | |
328 | { | |
329 | while (!list_empty(&shost->free_list)) { | |
330 | struct scsi_cmnd *cmd; | |
331 | ||
332 | cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); | |
333 | list_del_init(&cmd->list); | |
334 | kmem_cache_free(shost->cmd_pool->slab, cmd); | |
335 | } | |
336 | ||
0b950672 | 337 | mutex_lock(&host_cmd_pool_mutex); |
1da177e4 LT |
338 | if (!--shost->cmd_pool->users) |
339 | kmem_cache_destroy(shost->cmd_pool->slab); | |
0b950672 | 340 | mutex_unlock(&host_cmd_pool_mutex); |
1da177e4 LT |
341 | } |
342 | ||
343 | #ifdef CONFIG_SCSI_LOGGING | |
344 | void scsi_log_send(struct scsi_cmnd *cmd) | |
345 | { | |
346 | unsigned int level; | |
1da177e4 LT |
347 | |
348 | /* | |
349 | * If ML QUEUE log level is greater than or equal to: | |
350 | * | |
351 | * 1: nothing (match completion) | |
352 | * | |
353 | * 2: log opcode + command of all commands | |
354 | * | |
355 | * 3: same as 2 plus dump cmd address | |
356 | * | |
357 | * 4: same as 3 plus dump extra junk | |
358 | */ | |
359 | if (unlikely(scsi_logging_level)) { | |
360 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, | |
361 | SCSI_LOG_MLQUEUE_BITS); | |
362 | if (level > 1) { | |
a4d04a4c | 363 | scmd_printk(KERN_INFO, cmd, "Send: "); |
1da177e4 LT |
364 | if (level > 2) |
365 | printk("0x%p ", cmd); | |
a4d04a4c | 366 | printk("\n"); |
1da177e4 LT |
367 | scsi_print_command(cmd); |
368 | if (level > 3) { | |
369 | printk(KERN_INFO "buffer = 0x%p, bufflen = %d," | |
370 | " done = 0x%p, queuecommand 0x%p\n", | |
631c228c | 371 | cmd->request_buffer, cmd->request_bufflen, |
1da177e4 | 372 | cmd->done, |
a4d04a4c | 373 | cmd->device->host->hostt->queuecommand); |
1da177e4 LT |
374 | |
375 | } | |
376 | } | |
377 | } | |
378 | } | |
379 | ||
380 | void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) | |
381 | { | |
382 | unsigned int level; | |
1da177e4 LT |
383 | |
384 | /* | |
385 | * If ML COMPLETE log level is greater than or equal to: | |
386 | * | |
387 | * 1: log disposition, result, opcode + command, and conditionally | |
388 | * sense data for failures or non SUCCESS dispositions. | |
389 | * | |
390 | * 2: same as 1 but for all command completions. | |
391 | * | |
392 | * 3: same as 2 plus dump cmd address | |
393 | * | |
394 | * 4: same as 3 plus dump extra junk | |
395 | */ | |
396 | if (unlikely(scsi_logging_level)) { | |
397 | level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, | |
398 | SCSI_LOG_MLCOMPLETE_BITS); | |
399 | if (((level > 0) && (cmd->result || disposition != SUCCESS)) || | |
400 | (level > 1)) { | |
a4d04a4c | 401 | scmd_printk(KERN_INFO, cmd, "Done: "); |
1da177e4 LT |
402 | if (level > 2) |
403 | printk("0x%p ", cmd); | |
404 | /* | |
405 | * Dump truncated values, so we usually fit within | |
406 | * 80 chars. | |
407 | */ | |
408 | switch (disposition) { | |
409 | case SUCCESS: | |
a4d04a4c | 410 | printk("SUCCESS\n"); |
1da177e4 LT |
411 | break; |
412 | case NEEDS_RETRY: | |
a4d04a4c | 413 | printk("RETRY\n"); |
1da177e4 LT |
414 | break; |
415 | case ADD_TO_MLQUEUE: | |
a4d04a4c | 416 | printk("MLQUEUE\n"); |
1da177e4 LT |
417 | break; |
418 | case FAILED: | |
a4d04a4c | 419 | printk("FAILED\n"); |
1da177e4 LT |
420 | break; |
421 | case TIMEOUT_ERROR: | |
422 | /* | |
423 | * If called via scsi_times_out. | |
424 | */ | |
a4d04a4c | 425 | printk("TIMEOUT\n"); |
1da177e4 LT |
426 | break; |
427 | default: | |
a4d04a4c | 428 | printk("UNKNOWN\n"); |
1da177e4 | 429 | } |
a4d04a4c | 430 | scsi_print_result(cmd); |
1da177e4 | 431 | scsi_print_command(cmd); |
a4d04a4c | 432 | if (status_byte(cmd->result) & CHECK_CONDITION) |
1da177e4 | 433 | scsi_print_sense("", cmd); |
a4d04a4c MP |
434 | if (level > 3) |
435 | scmd_printk(KERN_INFO, cmd, | |
436 | "scsi host busy %d failed %d\n", | |
437 | cmd->device->host->host_busy, | |
438 | cmd->device->host->host_failed); | |
1da177e4 LT |
439 | } |
440 | } | |
441 | } | |
442 | #endif | |
443 | ||
444 | /* | |
445 | * Assign a serial number and pid to the request for error recovery | |
446 | * and debugging purposes. Protected by the Host_Lock of host. | |
447 | */ | |
448 | static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) | |
449 | { | |
450 | cmd->serial_number = host->cmd_serial_number++; | |
451 | if (cmd->serial_number == 0) | |
452 | cmd->serial_number = host->cmd_serial_number++; | |
453 | ||
454 | cmd->pid = host->cmd_pid++; | |
455 | if (cmd->pid == 0) | |
456 | cmd->pid = host->cmd_pid++; | |
457 | } | |
458 | ||
459 | /* | |
460 | * Function: scsi_dispatch_command | |
461 | * | |
462 | * Purpose: Dispatch a command to the low-level driver. | |
463 | * | |
464 | * Arguments: cmd - command block we are dispatching. | |
465 | * | |
466 | * Notes: | |
467 | */ | |
468 | int scsi_dispatch_cmd(struct scsi_cmnd *cmd) | |
469 | { | |
470 | struct Scsi_Host *host = cmd->device->host; | |
471 | unsigned long flags = 0; | |
472 | unsigned long timeout; | |
473 | int rtn = 0; | |
474 | ||
475 | /* check if the device is still usable */ | |
476 | if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { | |
477 | /* in SDEV_DEL we error all commands. DID_NO_CONNECT | |
478 | * returns an immediate error upwards, and signals | |
479 | * that the device is no longer present */ | |
480 | cmd->result = DID_NO_CONNECT << 16; | |
481 | atomic_inc(&cmd->device->iorequest_cnt); | |
69b52893 | 482 | __scsi_done(cmd); |
1da177e4 LT |
483 | /* return 0 (because the command has been processed) */ |
484 | goto out; | |
485 | } | |
486 | ||
487 | /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */ | |
488 | if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) { | |
489 | /* | |
490 | * in SDEV_BLOCK, the command is just put back on the device | |
491 | * queue. The suspend state has already blocked the queue so | |
492 | * future requests should not occur until the device | |
493 | * transitions out of the suspend state. | |
494 | */ | |
495 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); | |
496 | ||
497 | SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); | |
498 | ||
499 | /* | |
500 | * NOTE: rtn is still zero here because we don't need the | |
501 | * queue to be plugged on return (it's already stopped) | |
502 | */ | |
503 | goto out; | |
504 | } | |
505 | ||
506 | /* | |
507 | * If SCSI-2 or lower, store the LUN value in cmnd. | |
508 | */ | |
4d7db04a JB |
509 | if (cmd->device->scsi_level <= SCSI_2 && |
510 | cmd->device->scsi_level != SCSI_UNKNOWN) { | |
1da177e4 LT |
511 | cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
512 | (cmd->device->lun << 5 & 0xe0); | |
513 | } | |
514 | ||
515 | /* | |
516 | * We will wait MIN_RESET_DELAY clock ticks after the last reset so | |
517 | * we can avoid the drive not being ready. | |
518 | */ | |
519 | timeout = host->last_reset + MIN_RESET_DELAY; | |
520 | ||
521 | if (host->resetting && time_before(jiffies, timeout)) { | |
522 | int ticks_remaining = timeout - jiffies; | |
523 | /* | |
524 | * NOTE: This may be executed from within an interrupt | |
525 | * handler! This is bad, but for now, it'll do. The irq | |
526 | * level of the interrupt handler has been masked out by the | |
527 | * platform dependent interrupt handling code already, so the | |
528 | * sti() here will not cause another call to the SCSI host's | |
529 | * interrupt handler (assuming there is one irq-level per | |
530 | * host). | |
531 | */ | |
532 | while (--ticks_remaining >= 0) | |
533 | mdelay(1 + 999 / HZ); | |
534 | host->resetting = 0; | |
535 | } | |
536 | ||
537 | /* | |
538 | * AK: unlikely race here: for some reason the timer could | |
539 | * expire before the serial number is set up below. | |
540 | */ | |
541 | scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out); | |
542 | ||
543 | scsi_log_send(cmd); | |
544 | ||
545 | /* | |
546 | * We will use a queued command if possible, otherwise we will | |
547 | * emulate the queuing and calling of completion function ourselves. | |
548 | */ | |
1da177e4 LT |
549 | atomic_inc(&cmd->device->iorequest_cnt); |
550 | ||
551 | /* | |
552 | * Before we queue this command, check if the command | |
553 | * length exceeds what the host adapter can handle. | |
554 | */ | |
555 | if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) { | |
556 | SCSI_LOG_MLQUEUE(3, | |
557 | printk("queuecommand : command too long.\n")); | |
558 | cmd->result = (DID_ABORT << 16); | |
559 | ||
560 | scsi_done(cmd); | |
561 | goto out; | |
562 | } | |
563 | ||
564 | spin_lock_irqsave(host->host_lock, flags); | |
565 | scsi_cmd_get_serial(host, cmd); | |
566 | ||
d2c9d9ea | 567 | if (unlikely(host->shost_state == SHOST_DEL)) { |
1da177e4 LT |
568 | cmd->result = (DID_NO_CONNECT << 16); |
569 | scsi_done(cmd); | |
570 | } else { | |
571 | rtn = host->hostt->queuecommand(cmd, scsi_done); | |
572 | } | |
573 | spin_unlock_irqrestore(host->host_lock, flags); | |
574 | if (rtn) { | |
d8c37e7b TH |
575 | if (scsi_delete_timer(cmd)) { |
576 | atomic_inc(&cmd->device->iodone_cnt); | |
577 | scsi_queue_insert(cmd, | |
578 | (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ? | |
579 | rtn : SCSI_MLQUEUE_HOST_BUSY); | |
580 | } | |
1da177e4 LT |
581 | SCSI_LOG_MLQUEUE(3, |
582 | printk("queuecommand : request rejected\n")); | |
583 | } | |
584 | ||
585 | out: | |
586 | SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); | |
587 | return rtn; | |
588 | } | |
589 | ||
89f48c4d LT |
590 | /** |
591 | * scsi_req_abort_cmd -- Request command recovery for the specified command | |
592 | * cmd: pointer to the SCSI command of interest | |
593 | * | |
594 | * This function requests that SCSI Core start recovery for the | |
595 | * command by deleting the timer and adding the command to the eh | |
596 | * queue. It can be called by either LLDDs or SCSI Core. LLDDs who | |
597 | * implement their own error recovery MAY ignore the timeout event if | |
598 | * they generated scsi_req_abort_cmd. | |
599 | */ | |
600 | void scsi_req_abort_cmd(struct scsi_cmnd *cmd) | |
601 | { | |
602 | if (!scsi_delete_timer(cmd)) | |
603 | return; | |
604 | scsi_times_out(cmd); | |
605 | } | |
606 | EXPORT_SYMBOL(scsi_req_abort_cmd); | |
607 | ||
1da177e4 LT |
608 | /** |
609 | * scsi_done - Enqueue the finished SCSI command into the done queue. | |
610 | * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives | |
611 | * ownership back to SCSI Core -- i.e. the LLDD has finished with it. | |
612 | * | |
613 | * This function is the mid-level's (SCSI Core) interrupt routine, which | |
614 | * regains ownership of the SCSI command (de facto) from a LLDD, and enqueues | |
615 | * the command to the done queue for further processing. | |
616 | * | |
617 | * This is the producer of the done queue who enqueues at the tail. | |
618 | * | |
619 | * This function is interrupt context safe. | |
620 | */ | |
52c1da39 | 621 | static void scsi_done(struct scsi_cmnd *cmd) |
1da177e4 LT |
622 | { |
623 | /* | |
624 | * We don't have to worry about this one timing out any more. | |
625 | * If we are unable to remove the timer, then the command | |
626 | * has already timed out. In which case, we have no choice but to | |
627 | * let the timeout function run, as we have no idea where in fact | |
628 | * that function could really be. It might be on another processor, | |
629 | * etc, etc. | |
630 | */ | |
631 | if (!scsi_delete_timer(cmd)) | |
632 | return; | |
633 | __scsi_done(cmd); | |
634 | } | |
635 | ||
636 | /* Private entry to scsi_done() to complete a command when the timer | |
637 | * isn't running --- used by scsi_times_out */ | |
638 | void __scsi_done(struct scsi_cmnd *cmd) | |
639 | { | |
1aea6434 | 640 | struct request *rq = cmd->request; |
1da177e4 LT |
641 | |
642 | /* | |
643 | * Set the serial numbers back to zero | |
644 | */ | |
645 | cmd->serial_number = 0; | |
1da177e4 LT |
646 | |
647 | atomic_inc(&cmd->device->iodone_cnt); | |
648 | if (cmd->result) | |
649 | atomic_inc(&cmd->device->ioerr_cnt); | |
650 | ||
1aea6434 JA |
651 | BUG_ON(!rq); |
652 | ||
1da177e4 | 653 | /* |
1aea6434 JA |
654 | * The uptodate/nbytes values don't matter, as we allow partial |
655 | * completes and thus will check this in the softirq callback | |
1da177e4 | 656 | */ |
1aea6434 JA |
657 | rq->completion_data = cmd; |
658 | blk_complete_request(rq); | |
1da177e4 LT |
659 | } |
660 | ||
1da177e4 LT |
661 | /* |
662 | * Function: scsi_finish_command | |
663 | * | |
664 | * Purpose: Pass command off to upper layer for finishing of I/O | |
665 | * request, waking processes that are waiting on results, | |
666 | * etc. | |
667 | */ | |
668 | void scsi_finish_command(struct scsi_cmnd *cmd) | |
669 | { | |
670 | struct scsi_device *sdev = cmd->device; | |
671 | struct Scsi_Host *shost = sdev->host; | |
1da177e4 LT |
672 | |
673 | scsi_device_unbusy(sdev); | |
674 | ||
675 | /* | |
676 | * Clear the flags which say that the device/host is no longer | |
677 | * capable of accepting new commands. These are set in scsi_queue.c | |
678 | * for both the queue full condition on a device, and for a | |
679 | * host full condition on the host. | |
680 | * | |
681 | * XXX(hch): What about locking? | |
682 | */ | |
683 | shost->host_blocked = 0; | |
684 | sdev->device_blocked = 0; | |
685 | ||
686 | /* | |
687 | * If we have valid sense information, then some kind of recovery | |
688 | * must have taken place. Make a note of this. | |
689 | */ | |
690 | if (SCSI_SENSE_VALID(cmd)) | |
691 | cmd->result |= (DRIVER_SENSE << 24); | |
692 | ||
3bf743e7 JG |
693 | SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
694 | "Notifying upper driver of completion " | |
695 | "(result %x)\n", cmd->result)); | |
1da177e4 | 696 | |
1da177e4 LT |
697 | cmd->done(cmd); |
698 | } | |
699 | EXPORT_SYMBOL(scsi_finish_command); | |
700 | ||
701 | /* | |
702 | * Function: scsi_adjust_queue_depth() | |
703 | * | |
704 | * Purpose: Allow low level drivers to tell us to change the queue depth | |
705 | * on a specific SCSI device | |
706 | * | |
707 | * Arguments: sdev - SCSI Device in question | |
708 | * tagged - Do we use tagged queueing (non-0) or do we treat | |
709 | * this device as an untagged device (0) | |
710 | * tags - Number of tags allowed if tagged queueing enabled, | |
711 | * or number of commands the low level driver can | |
712 | * queue up in non-tagged mode (as per cmd_per_lun). | |
713 | * | |
714 | * Returns: Nothing | |
715 | * | |
716 | * Lock Status: None held on entry | |
717 | * | |
718 | * Notes: Low level drivers may call this at any time and we will do | |
719 | * the right thing depending on whether or not the device is | |
720 | * currently active and whether or not it even has the | |
721 | * command blocks built yet. | |
722 | */ | |
723 | void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) | |
724 | { | |
725 | unsigned long flags; | |
726 | ||
727 | /* | |
728 | * refuse to set tagged depth to an unworkable size | |
729 | */ | |
730 | if (tags <= 0) | |
731 | return; | |
732 | ||
733 | spin_lock_irqsave(sdev->request_queue->queue_lock, flags); | |
734 | ||
735 | /* Check to see if the queue is managed by the block layer | |
736 | * if it is, and we fail to adjust the depth, exit */ | |
737 | if (blk_queue_tagged(sdev->request_queue) && | |
738 | blk_queue_resize_tags(sdev->request_queue, tags) != 0) | |
739 | goto out; | |
740 | ||
741 | sdev->queue_depth = tags; | |
742 | switch (tagged) { | |
743 | case MSG_ORDERED_TAG: | |
744 | sdev->ordered_tags = 1; | |
745 | sdev->simple_tags = 1; | |
746 | break; | |
747 | case MSG_SIMPLE_TAG: | |
748 | sdev->ordered_tags = 0; | |
749 | sdev->simple_tags = 1; | |
750 | break; | |
751 | default: | |
9ccfc756 JB |
752 | sdev_printk(KERN_WARNING, sdev, |
753 | "scsi_adjust_queue_depth, bad queue type, " | |
754 | "disabled\n"); | |
1da177e4 LT |
755 | case 0: |
756 | sdev->ordered_tags = sdev->simple_tags = 0; | |
757 | sdev->queue_depth = tags; | |
758 | break; | |
759 | } | |
760 | out: | |
761 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); | |
762 | } | |
763 | EXPORT_SYMBOL(scsi_adjust_queue_depth); | |
764 | ||
765 | /* | |
766 | * Function: scsi_track_queue_full() | |
767 | * | |
768 | * Purpose: This function will track successive QUEUE_FULL events on a | |
769 | * specific SCSI device to determine if and when there is a | |
770 | * need to adjust the queue depth on the device. | |
771 | * | |
772 | * Arguments: sdev - SCSI Device in question | |
773 | * depth - Current number of outstanding SCSI commands on | |
774 | * this device, not counting the one returned as | |
775 | * QUEUE_FULL. | |
776 | * | |
777 | * Returns: 0 - No change needed | |
778 | * >0 - Adjust queue depth to this new depth | |
779 | * -1 - Drop back to untagged operation using host->cmd_per_lun | |
780 | * as the untagged command depth | |
781 | * | |
782 | * Lock Status: None held on entry | |
783 | * | |
784 | * Notes: Low level drivers may call this at any time and we will do | |
785 | * "The Right Thing." We are interrupt context safe. | |
786 | */ | |
787 | int scsi_track_queue_full(struct scsi_device *sdev, int depth) | |
788 | { | |
789 | if ((jiffies >> 4) == sdev->last_queue_full_time) | |
790 | return 0; | |
791 | ||
792 | sdev->last_queue_full_time = (jiffies >> 4); | |
793 | if (sdev->last_queue_full_depth != depth) { | |
794 | sdev->last_queue_full_count = 1; | |
795 | sdev->last_queue_full_depth = depth; | |
796 | } else { | |
797 | sdev->last_queue_full_count++; | |
798 | } | |
799 | ||
800 | if (sdev->last_queue_full_count <= 10) | |
801 | return 0; | |
802 | if (sdev->last_queue_full_depth < 8) { | |
803 | /* Drop back to untagged */ | |
804 | scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); | |
805 | return -1; | |
806 | } | |
807 | ||
808 | if (sdev->ordered_tags) | |
809 | scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); | |
810 | else | |
811 | scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); | |
812 | return depth; | |
813 | } | |
814 | EXPORT_SYMBOL(scsi_track_queue_full); | |
815 | ||
816 | /** | |
817 | * scsi_device_get - get an addition reference to a scsi_device | |
818 | * @sdev: device to get a reference to | |
819 | * | |
820 | * Gets a reference to the scsi_device and increments the use count | |
821 | * of the underlying LLDD module. You must hold host_lock of the | |
822 | * parent Scsi_Host or already have a reference when calling this. | |
823 | */ | |
824 | int scsi_device_get(struct scsi_device *sdev) | |
825 | { | |
85b6c720 | 826 | if (sdev->sdev_state == SDEV_DEL) |
1da177e4 LT |
827 | return -ENXIO; |
828 | if (!get_device(&sdev->sdev_gendev)) | |
829 | return -ENXIO; | |
85b6c720 JB |
830 | /* We can fail this if we're doing SCSI operations |
831 | * from module exit (like cache flush) */ | |
832 | try_module_get(sdev->host->hostt->module); | |
833 | ||
1da177e4 LT |
834 | return 0; |
835 | } | |
836 | EXPORT_SYMBOL(scsi_device_get); | |
837 | ||
838 | /** | |
839 | * scsi_device_put - release a reference to a scsi_device | |
840 | * @sdev: device to release a reference on. | |
841 | * | |
842 | * Release a reference to the scsi_device and decrements the use count | |
843 | * of the underlying LLDD module. The device is freed once the last | |
844 | * user vanishes. | |
845 | */ | |
846 | void scsi_device_put(struct scsi_device *sdev) | |
847 | { | |
504fb37a | 848 | #ifdef CONFIG_MODULE_UNLOAD |
f479ab87 JB |
849 | struct module *module = sdev->host->hostt->module; |
850 | ||
85b6c720 JB |
851 | /* The module refcount will be zero if scsi_device_get() |
852 | * was called from a module removal routine */ | |
f479ab87 JB |
853 | if (module && module_refcount(module) != 0) |
854 | module_put(module); | |
a506b44b | 855 | #endif |
1da177e4 LT |
856 | put_device(&sdev->sdev_gendev); |
857 | } | |
858 | EXPORT_SYMBOL(scsi_device_put); | |
859 | ||
860 | /* helper for shost_for_each_device, thus not documented */ | |
861 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, | |
862 | struct scsi_device *prev) | |
863 | { | |
864 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); | |
865 | struct scsi_device *next = NULL; | |
866 | unsigned long flags; | |
867 | ||
868 | spin_lock_irqsave(shost->host_lock, flags); | |
869 | while (list->next != &shost->__devices) { | |
870 | next = list_entry(list->next, struct scsi_device, siblings); | |
871 | /* skip devices that we can't get a reference to */ | |
872 | if (!scsi_device_get(next)) | |
873 | break; | |
874 | next = NULL; | |
875 | list = list->next; | |
876 | } | |
877 | spin_unlock_irqrestore(shost->host_lock, flags); | |
878 | ||
879 | if (prev) | |
880 | scsi_device_put(prev); | |
881 | return next; | |
882 | } | |
883 | EXPORT_SYMBOL(__scsi_iterate_devices); | |
884 | ||
885 | /** | |
886 | * starget_for_each_device - helper to walk all devices of a target | |
887 | * @starget: target whose devices we want to iterate over. | |
888 | * | |
889 | * This traverses over each devices of @shost. The devices have | |
890 | * a reference that must be released by scsi_host_put when breaking | |
891 | * out of the loop. | |
892 | */ | |
893 | void starget_for_each_device(struct scsi_target *starget, void * data, | |
894 | void (*fn)(struct scsi_device *, void *)) | |
895 | { | |
896 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
897 | struct scsi_device *sdev; | |
898 | ||
899 | shost_for_each_device(sdev, shost) { | |
900 | if ((sdev->channel == starget->channel) && | |
901 | (sdev->id == starget->id)) | |
902 | fn(sdev, data); | |
903 | } | |
904 | } | |
905 | EXPORT_SYMBOL(starget_for_each_device); | |
906 | ||
907 | /** | |
908 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) | |
909 | * @starget: SCSI target pointer | |
910 | * @lun: SCSI Logical Unit Number | |
911 | * | |
912 | * Looks up the scsi_device with the specified @lun for a give | |
913 | * @starget. The returned scsi_device does not have an additional | |
914 | * reference. You must hold the host's host_lock over this call and | |
915 | * any access to the returned scsi_device. | |
916 | * | |
917 | * Note: The only reason why drivers would want to use this is because | |
918 | * they're need to access the device list in irq context. Otherwise you | |
919 | * really want to use scsi_device_lookup_by_target instead. | |
920 | **/ | |
921 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, | |
922 | uint lun) | |
923 | { | |
924 | struct scsi_device *sdev; | |
925 | ||
926 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { | |
927 | if (sdev->lun ==lun) | |
928 | return sdev; | |
929 | } | |
930 | ||
931 | return NULL; | |
932 | } | |
933 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); | |
934 | ||
935 | /** | |
936 | * scsi_device_lookup_by_target - find a device given the target | |
937 | * @starget: SCSI target pointer | |
938 | * @lun: SCSI Logical Unit Number | |
939 | * | |
940 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
941 | * give host. The returned scsi_device has an additional reference that | |
942 | * needs to be release with scsi_host_put once you're done with it. | |
943 | **/ | |
944 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, | |
945 | uint lun) | |
946 | { | |
947 | struct scsi_device *sdev; | |
948 | struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); | |
949 | unsigned long flags; | |
950 | ||
951 | spin_lock_irqsave(shost->host_lock, flags); | |
952 | sdev = __scsi_device_lookup_by_target(starget, lun); | |
953 | if (sdev && scsi_device_get(sdev)) | |
954 | sdev = NULL; | |
955 | spin_unlock_irqrestore(shost->host_lock, flags); | |
956 | ||
957 | return sdev; | |
958 | } | |
959 | EXPORT_SYMBOL(scsi_device_lookup_by_target); | |
960 | ||
961 | /** | |
962 | * scsi_device_lookup - find a device given the host (UNLOCKED) | |
963 | * @shost: SCSI host pointer | |
964 | * @channel: SCSI channel (zero if only one channel) | |
965 | * @pun: SCSI target number (physical unit number) | |
966 | * @lun: SCSI Logical Unit Number | |
967 | * | |
968 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
969 | * give host. The returned scsi_device does not have an additional reference. | |
970 | * You must hold the host's host_lock over this call and any access to the | |
971 | * returned scsi_device. | |
972 | * | |
973 | * Note: The only reason why drivers would want to use this is because | |
974 | * they're need to access the device list in irq context. Otherwise you | |
975 | * really want to use scsi_device_lookup instead. | |
976 | **/ | |
977 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, | |
978 | uint channel, uint id, uint lun) | |
979 | { | |
980 | struct scsi_device *sdev; | |
981 | ||
982 | list_for_each_entry(sdev, &shost->__devices, siblings) { | |
983 | if (sdev->channel == channel && sdev->id == id && | |
984 | sdev->lun ==lun) | |
985 | return sdev; | |
986 | } | |
987 | ||
988 | return NULL; | |
989 | } | |
990 | EXPORT_SYMBOL(__scsi_device_lookup); | |
991 | ||
992 | /** | |
993 | * scsi_device_lookup - find a device given the host | |
994 | * @shost: SCSI host pointer | |
995 | * @channel: SCSI channel (zero if only one channel) | |
996 | * @id: SCSI target number (physical unit number) | |
997 | * @lun: SCSI Logical Unit Number | |
998 | * | |
999 | * Looks up the scsi_device with the specified @channel, @id, @lun for a | |
1000 | * give host. The returned scsi_device has an additional reference that | |
1001 | * needs to be release with scsi_host_put once you're done with it. | |
1002 | **/ | |
1003 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, | |
1004 | uint channel, uint id, uint lun) | |
1005 | { | |
1006 | struct scsi_device *sdev; | |
1007 | unsigned long flags; | |
1008 | ||
1009 | spin_lock_irqsave(shost->host_lock, flags); | |
1010 | sdev = __scsi_device_lookup(shost, channel, id, lun); | |
1011 | if (sdev && scsi_device_get(sdev)) | |
1012 | sdev = NULL; | |
1013 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1014 | ||
1015 | return sdev; | |
1016 | } | |
1017 | EXPORT_SYMBOL(scsi_device_lookup); | |
1018 | ||
1da177e4 LT |
1019 | MODULE_DESCRIPTION("SCSI core"); |
1020 | MODULE_LICENSE("GPL"); | |
1021 | ||
1022 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); | |
1023 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); | |
1024 | ||
1025 | static int __init init_scsi(void) | |
1026 | { | |
9bf09c23 | 1027 | int error; |
1da177e4 LT |
1028 | |
1029 | error = scsi_init_queue(); | |
1030 | if (error) | |
1031 | return error; | |
1032 | error = scsi_init_procfs(); | |
1033 | if (error) | |
1034 | goto cleanup_queue; | |
1035 | error = scsi_init_devinfo(); | |
1036 | if (error) | |
1037 | goto cleanup_procfs; | |
1038 | error = scsi_init_hosts(); | |
1039 | if (error) | |
1040 | goto cleanup_devlist; | |
1041 | error = scsi_init_sysctl(); | |
1042 | if (error) | |
1043 | goto cleanup_hosts; | |
1044 | error = scsi_sysfs_register(); | |
1045 | if (error) | |
1046 | goto cleanup_sysctl; | |
1047 | ||
84314fd4 JS |
1048 | scsi_netlink_init(); |
1049 | ||
1da177e4 LT |
1050 | printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
1051 | return 0; | |
1052 | ||
1053 | cleanup_sysctl: | |
1054 | scsi_exit_sysctl(); | |
1055 | cleanup_hosts: | |
1056 | scsi_exit_hosts(); | |
1057 | cleanup_devlist: | |
1058 | scsi_exit_devinfo(); | |
1059 | cleanup_procfs: | |
1060 | scsi_exit_procfs(); | |
1061 | cleanup_queue: | |
1062 | scsi_exit_queue(); | |
1063 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", | |
1064 | -error); | |
1065 | return error; | |
1066 | } | |
1067 | ||
1068 | static void __exit exit_scsi(void) | |
1069 | { | |
84314fd4 | 1070 | scsi_netlink_exit(); |
1da177e4 LT |
1071 | scsi_sysfs_unregister(); |
1072 | scsi_exit_sysctl(); | |
1073 | scsi_exit_hosts(); | |
1074 | scsi_exit_devinfo(); | |
1da177e4 LT |
1075 | scsi_exit_procfs(); |
1076 | scsi_exit_queue(); | |
1da177e4 LT |
1077 | } |
1078 | ||
1079 | subsys_initcall(init_scsi); | |
1080 | module_exit(exit_scsi); |