Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * scsi.c Copyright (C) 1992 Drew Eckhardt
4 : * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
5 : * Copyright (C) 2002, 2003 Christoph Hellwig
6 : *
7 : * generic mid-level SCSI driver
8 : * Initial versions: Drew Eckhardt
9 : * Subsequent revisions: Eric Youngdale
10 : *
11 : * <drew@colorado.edu>
12 : *
13 : * Bug correction thanks go to :
14 : * Rik Faith <faith@cs.unc.edu>
15 : * Tommy Thorn <tthorn>
16 : * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
17 : *
18 : * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
19 : * add scatter-gather, multiple outstanding request, and other
20 : * enhancements.
21 : *
22 : * Native multichannel, wide scsi, /proc/scsi and hot plugging
23 : * support added by Michael Neuffer <mike@i-connect.net>
24 : *
25 : * Added request_module("scsi_hostadapter") for kerneld:
26 : * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
27 : * Bjorn Ekwall <bj0rn@blox.se>
28 : * (changed to kmod)
29 : *
30 : * Major improvements to the timeout, abort, and reset processing,
31 : * as well as performance modifications for large queue depths by
32 : * Leonard N. Zubkoff <lnz@dandelion.com>
33 : *
34 : * Converted cli() code to spinlocks, Ingo Molnar
35 : *
36 : * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
37 : *
38 : * out_of_space hacks, D. Gilbert (dpg) 990608
39 : */
40 :
41 : #include <linux/module.h>
42 : #include <linux/moduleparam.h>
43 : #include <linux/kernel.h>
44 : #include <linux/timer.h>
45 : #include <linux/string.h>
46 : #include <linux/slab.h>
47 : #include <linux/blkdev.h>
48 : #include <linux/delay.h>
49 : #include <linux/init.h>
50 : #include <linux/completion.h>
51 : #include <linux/unistd.h>
52 : #include <linux/spinlock.h>
53 : #include <linux/kmod.h>
54 : #include <linux/interrupt.h>
55 : #include <linux/notifier.h>
56 : #include <linux/cpu.h>
57 : #include <linux/mutex.h>
58 : #include <linux/async.h>
59 : #include <asm/unaligned.h>
60 :
61 : #include <scsi/scsi.h>
62 : #include <scsi/scsi_cmnd.h>
63 : #include <scsi/scsi_dbg.h>
64 : #include <scsi/scsi_device.h>
65 : #include <scsi/scsi_driver.h>
66 : #include <scsi/scsi_eh.h>
67 : #include <scsi/scsi_host.h>
68 : #include <scsi/scsi_tcq.h>
69 :
70 : #include "scsi_priv.h"
71 : #include "scsi_logging.h"
72 :
73 : #define CREATE_TRACE_POINTS
74 : #include <trace/events/scsi.h>
75 :
76 : /*
77 : * Definitions and constants.
78 : */
79 :
80 : /*
81 : * Note - the initial logging level can be set here to log events at boot time.
82 : * After the system is up, you may enable logging via the /proc interface.
83 : */
84 : unsigned int scsi_logging_level;
85 : #if defined(CONFIG_SCSI_LOGGING)
86 : EXPORT_SYMBOL(scsi_logging_level);
87 : #endif
88 :
89 : /*
90 : * Domain for asynchronous system resume operations. It is marked 'exclusive'
91 : * to avoid being included in the async_synchronize_full() that is invoked by
92 : * dpm_resume().
93 : */
94 : ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
95 : EXPORT_SYMBOL(scsi_sd_pm_domain);
96 :
97 : #ifdef CONFIG_SCSI_LOGGING
98 : void scsi_log_send(struct scsi_cmnd *cmd)
99 : {
100 : unsigned int level;
101 :
102 : /*
103 : * If ML QUEUE log level is greater than or equal to:
104 : *
105 : * 1: nothing (match completion)
106 : *
107 : * 2: log opcode + command of all commands + cmd address
108 : *
109 : * 3: same as 2
110 : *
111 : * 4: same as 3
112 : */
113 : if (unlikely(scsi_logging_level)) {
114 : level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
115 : SCSI_LOG_MLQUEUE_BITS);
116 : if (level > 1) {
117 : scmd_printk(KERN_INFO, cmd,
118 : "Send: scmd 0x%p\n", cmd);
119 : scsi_print_command(cmd);
120 : }
121 : }
122 : }
123 :
124 : void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
125 : {
126 : unsigned int level;
127 :
128 : /*
129 : * If ML COMPLETE log level is greater than or equal to:
130 : *
131 : * 1: log disposition, result, opcode + command, and conditionally
132 : * sense data for failures or non SUCCESS dispositions.
133 : *
134 : * 2: same as 1 but for all command completions.
135 : *
136 : * 3: same as 2
137 : *
138 : * 4: same as 3 plus dump extra junk
139 : */
140 : if (unlikely(scsi_logging_level)) {
141 : level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
142 : SCSI_LOG_MLCOMPLETE_BITS);
143 : if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
144 : (level > 1)) {
145 : scsi_print_result(cmd, "Done", disposition);
146 : scsi_print_command(cmd);
147 : if (status_byte(cmd->result) == CHECK_CONDITION)
148 : scsi_print_sense(cmd);
149 : if (level > 3)
150 : scmd_printk(KERN_INFO, cmd,
151 : "scsi host busy %d failed %d\n",
152 : scsi_host_busy(cmd->device->host),
153 : cmd->device->host->host_failed);
154 : }
155 : }
156 : }
157 : #endif
158 :
159 : /**
160 : * scsi_finish_command - cleanup and pass command back to upper layer
161 : * @cmd: the command
162 : *
163 : * Description: Pass command off to upper layer for finishing of I/O
164 : * request, waking processes that are waiting on results,
165 : * etc.
166 : */
167 0 : void scsi_finish_command(struct scsi_cmnd *cmd)
168 : {
169 0 : struct scsi_device *sdev = cmd->device;
170 0 : struct scsi_target *starget = scsi_target(sdev);
171 0 : struct Scsi_Host *shost = sdev->host;
172 0 : struct scsi_driver *drv;
173 0 : unsigned int good_bytes;
174 :
175 0 : scsi_device_unbusy(sdev, cmd);
176 :
177 : /*
178 : * Clear the flags that say that the device/target/host is no longer
179 : * capable of accepting new commands.
180 : */
181 0 : if (atomic_read(&shost->host_blocked))
182 0 : atomic_set(&shost->host_blocked, 0);
183 0 : if (atomic_read(&starget->target_blocked))
184 0 : atomic_set(&starget->target_blocked, 0);
185 0 : if (atomic_read(&sdev->device_blocked))
186 0 : atomic_set(&sdev->device_blocked, 0);
187 :
188 : /*
189 : * If we have valid sense information, then some kind of recovery
190 : * must have taken place. Make a note of this.
191 : */
192 0 : if (SCSI_SENSE_VALID(cmd))
193 0 : cmd->result |= (DRIVER_SENSE << 24);
194 :
195 0 : SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
196 : "Notifying upper driver of completion "
197 0 : "(result %x)\n", cmd->result));
198 :
199 0 : good_bytes = scsi_bufflen(cmd);
200 0 : if (!blk_rq_is_passthrough(cmd->request)) {
201 0 : int old_good_bytes = good_bytes;
202 0 : drv = scsi_cmd_to_driver(cmd);
203 0 : if (drv->done)
204 0 : good_bytes = drv->done(cmd);
205 : /*
206 : * USB may not give sense identifying bad sector and
207 : * simply return a residue instead, so subtract off the
208 : * residue if drv->done() error processing indicates no
209 : * change to the completion length.
210 : */
211 0 : if (good_bytes == old_good_bytes)
212 0 : good_bytes -= scsi_get_resid(cmd);
213 : }
214 0 : scsi_io_completion(cmd, good_bytes);
215 0 : }
216 :
217 : /**
218 : * scsi_change_queue_depth - change a device's queue depth
219 : * @sdev: SCSI Device in question
220 : * @depth: number of commands allowed to be queued to the driver
221 : *
222 : * Sets the device queue depth and returns the new value.
223 : */
224 0 : int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
225 : {
226 0 : if (depth > 0) {
227 0 : sdev->queue_depth = depth;
228 0 : wmb();
229 : }
230 :
231 0 : if (sdev->request_queue)
232 0 : blk_set_queue_depth(sdev->request_queue, depth);
233 :
234 0 : return sdev->queue_depth;
235 : }
236 : EXPORT_SYMBOL(scsi_change_queue_depth);
237 :
238 : /**
239 : * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
240 : * @sdev: SCSI Device in question
241 : * @depth: Current number of outstanding SCSI commands on this device,
242 : * not counting the one returned as QUEUE_FULL.
243 : *
244 : * Description: This function will track successive QUEUE_FULL events on a
245 : * specific SCSI device to determine if and when there is a
246 : * need to adjust the queue depth on the device.
247 : *
248 : * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
249 : * -1 - Drop back to untagged operation using host->cmd_per_lun
250 : * as the untagged command depth
251 : *
252 : * Lock Status: None held on entry
253 : *
254 : * Notes: Low level drivers may call this at any time and we will do
255 : * "The Right Thing." We are interrupt context safe.
256 : */
257 0 : int scsi_track_queue_full(struct scsi_device *sdev, int depth)
258 : {
259 :
260 : /*
261 : * Don't let QUEUE_FULLs on the same
262 : * jiffies count, they could all be from
263 : * same event.
264 : */
265 0 : if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
266 : return 0;
267 :
268 0 : sdev->last_queue_full_time = jiffies;
269 0 : if (sdev->last_queue_full_depth != depth) {
270 0 : sdev->last_queue_full_count = 1;
271 0 : sdev->last_queue_full_depth = depth;
272 : } else {
273 0 : sdev->last_queue_full_count++;
274 : }
275 :
276 0 : if (sdev->last_queue_full_count <= 10)
277 : return 0;
278 :
279 0 : return scsi_change_queue_depth(sdev, depth);
280 : }
281 : EXPORT_SYMBOL(scsi_track_queue_full);
282 :
283 : /**
284 : * scsi_vpd_inquiry - Request a device provide us with a VPD page
285 : * @sdev: The device to ask
286 : * @buffer: Where to put the result
287 : * @page: Which Vital Product Data to return
288 : * @len: The length of the buffer
289 : *
290 : * This is an internal helper function. You probably want to use
291 : * scsi_get_vpd_page instead.
292 : *
293 : * Returns size of the vpd page on success or a negative error number.
294 : */
295 0 : static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
296 : u8 page, unsigned len)
297 : {
298 0 : int result;
299 0 : unsigned char cmd[16];
300 :
301 0 : if (len < 4)
302 : return -EINVAL;
303 :
304 0 : cmd[0] = INQUIRY;
305 0 : cmd[1] = 1; /* EVPD */
306 0 : cmd[2] = page;
307 0 : cmd[3] = len >> 8;
308 0 : cmd[4] = len & 0xff;
309 0 : cmd[5] = 0; /* Control byte */
310 :
311 : /*
312 : * I'm not convinced we need to try quite this hard to get VPD, but
313 : * all the existing users tried this hard.
314 : */
315 0 : result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
316 : len, NULL, 30 * HZ, 3, NULL);
317 0 : if (result)
318 : return -EIO;
319 :
320 : /* Sanity check that we got the page back that we asked for */
321 0 : if (buffer[1] != page)
322 : return -EIO;
323 :
324 0 : return get_unaligned_be16(&buffer[2]) + 4;
325 : }
326 :
327 : /**
328 : * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
329 : * @sdev: The device to ask
330 : * @page: Which Vital Product Data to return
331 : * @buf: where to store the VPD
332 : * @buf_len: number of bytes in the VPD buffer area
333 : *
334 : * SCSI devices may optionally supply Vital Product Data. Each 'page'
335 : * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
336 : * If the device supports this VPD page, this routine returns a pointer
337 : * to a buffer containing the data from that page. The caller is
338 : * responsible for calling kfree() on this pointer when it is no longer
339 : * needed. If we cannot retrieve the VPD page this routine returns %NULL.
340 : */
341 0 : int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
342 : int buf_len)
343 : {
344 0 : int i, result;
345 :
346 0 : if (sdev->skip_vpd_pages)
347 0 : goto fail;
348 :
349 : /* Ask for all the pages supported by this device */
350 0 : result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
351 0 : if (result < 4)
352 0 : goto fail;
353 :
354 : /* If the user actually wanted this page, we can skip the rest */
355 0 : if (page == 0)
356 : return 0;
357 :
358 0 : for (i = 4; i < min(result, buf_len); i++)
359 0 : if (buf[i] == page)
360 0 : goto found;
361 :
362 0 : if (i < result && i >= buf_len)
363 : /* ran off the end of the buffer, give us benefit of doubt */
364 0 : goto found;
365 : /* The device claims it doesn't support the requested page */
366 0 : goto fail;
367 :
368 0 : found:
369 0 : result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
370 0 : if (result < 0)
371 0 : goto fail;
372 :
373 : return 0;
374 :
375 : fail:
376 : return -EINVAL;
377 : }
378 : EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
379 :
380 : /**
381 : * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
382 : * @sdev: The device to ask
383 : * @page: Which Vital Product Data to return
384 : *
385 : * Returns %NULL upon failure.
386 : */
387 0 : static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
388 : {
389 0 : struct scsi_vpd *vpd_buf;
390 0 : int vpd_len = SCSI_VPD_PG_LEN, result;
391 :
392 0 : retry_pg:
393 0 : vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL);
394 0 : if (!vpd_buf)
395 : return NULL;
396 :
397 0 : result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len);
398 0 : if (result < 0) {
399 0 : kfree(vpd_buf);
400 0 : return NULL;
401 : }
402 0 : if (result > vpd_len) {
403 0 : vpd_len = result;
404 0 : kfree(vpd_buf);
405 0 : goto retry_pg;
406 : }
407 :
408 0 : vpd_buf->len = result;
409 :
410 0 : return vpd_buf;
411 : }
412 :
413 0 : static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
414 : struct scsi_vpd __rcu **sdev_vpd_buf)
415 : {
416 0 : struct scsi_vpd *vpd_buf;
417 :
418 0 : vpd_buf = scsi_get_vpd_buf(sdev, page);
419 0 : if (!vpd_buf)
420 : return;
421 :
422 0 : mutex_lock(&sdev->inquiry_mutex);
423 0 : vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf,
424 : lockdep_is_held(&sdev->inquiry_mutex));
425 0 : mutex_unlock(&sdev->inquiry_mutex);
426 :
427 0 : if (vpd_buf)
428 0 : kfree_rcu(vpd_buf, rcu);
429 : }
430 :
431 : /**
432 : * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
433 : * @sdev: The device to ask
434 : *
435 : * Attach the 'Device Identification' VPD page (0x83) and the
436 : * 'Unit Serial Number' VPD page (0x80) to a SCSI device
437 : * structure. This information can be used to identify the device
438 : * uniquely.
439 : */
440 0 : void scsi_attach_vpd(struct scsi_device *sdev)
441 : {
442 0 : int i;
443 0 : struct scsi_vpd *vpd_buf;
444 :
445 0 : if (!scsi_device_supports_vpd(sdev))
446 : return;
447 :
448 : /* Ask for all the pages supported by this device */
449 0 : vpd_buf = scsi_get_vpd_buf(sdev, 0);
450 0 : if (!vpd_buf)
451 : return;
452 :
453 0 : for (i = 4; i < vpd_buf->len; i++) {
454 0 : if (vpd_buf->data[i] == 0x0)
455 0 : scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0);
456 0 : if (vpd_buf->data[i] == 0x80)
457 0 : scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
458 0 : if (vpd_buf->data[i] == 0x83)
459 0 : scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
460 0 : if (vpd_buf->data[i] == 0x89)
461 0 : scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89);
462 : }
463 0 : kfree(vpd_buf);
464 : }
465 :
466 : /**
467 : * scsi_report_opcode - Find out if a given command opcode is supported
468 : * @sdev: scsi device to query
469 : * @buffer: scratch buffer (must be at least 20 bytes long)
470 : * @len: length of buffer
471 : * @opcode: opcode for command to look up
472 : *
473 : * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
474 : * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
475 : * unsupported and 1 if the device claims to support the command.
476 : */
477 0 : int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
478 : unsigned int len, unsigned char opcode)
479 : {
480 0 : unsigned char cmd[16];
481 0 : struct scsi_sense_hdr sshdr;
482 0 : int result;
483 :
484 0 : if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
485 : return -EINVAL;
486 :
487 0 : memset(cmd, 0, 16);
488 0 : cmd[0] = MAINTENANCE_IN;
489 0 : cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
490 0 : cmd[2] = 1; /* One command format */
491 0 : cmd[3] = opcode;
492 0 : put_unaligned_be32(len, &cmd[6]);
493 0 : memset(buffer, 0, len);
494 :
495 0 : result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
496 : &sshdr, 30 * HZ, 3, NULL);
497 :
498 0 : if (result && scsi_sense_valid(&sshdr) &&
499 0 : sshdr.sense_key == ILLEGAL_REQUEST &&
500 0 : (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
501 : return -EINVAL;
502 :
503 0 : if ((buffer[1] & 3) == 3) /* Command supported */
504 0 : return 1;
505 :
506 : return 0;
507 : }
508 : EXPORT_SYMBOL(scsi_report_opcode);
509 :
510 : /**
511 : * scsi_device_get - get an additional reference to a scsi_device
512 : * @sdev: device to get a reference to
513 : *
514 : * Description: Gets a reference to the scsi_device and increments the use count
515 : * of the underlying LLDD module. You must hold host_lock of the
516 : * parent Scsi_Host or already have a reference when calling this.
517 : *
518 : * This will fail if a device is deleted or cancelled, or when the LLD module
519 : * is in the process of being unloaded.
520 : */
521 0 : int scsi_device_get(struct scsi_device *sdev)
522 : {
523 0 : if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
524 0 : goto fail;
525 0 : if (!get_device(&sdev->sdev_gendev))
526 0 : goto fail;
527 0 : if (!try_module_get(sdev->host->hostt->module))
528 : goto fail_put_device;
529 : return 0;
530 :
531 : fail_put_device:
532 : put_device(&sdev->sdev_gendev);
533 : fail:
534 : return -ENXIO;
535 : }
536 : EXPORT_SYMBOL(scsi_device_get);
537 :
538 : /**
539 : * scsi_device_put - release a reference to a scsi_device
540 : * @sdev: device to release a reference on.
541 : *
542 : * Description: Release a reference to the scsi_device and decrements the use
543 : * count of the underlying LLDD module. The device is freed once the last
544 : * user vanishes.
545 : */
546 0 : void scsi_device_put(struct scsi_device *sdev)
547 : {
548 0 : module_put(sdev->host->hostt->module);
549 0 : put_device(&sdev->sdev_gendev);
550 0 : }
551 : EXPORT_SYMBOL(scsi_device_put);
552 :
553 : /* helper for shost_for_each_device, see that for documentation */
554 0 : struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
555 : struct scsi_device *prev)
556 : {
557 0 : struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
558 0 : struct scsi_device *next = NULL;
559 0 : unsigned long flags;
560 :
561 0 : spin_lock_irqsave(shost->host_lock, flags);
562 0 : while (list->next != &shost->__devices) {
563 0 : next = list_entry(list->next, struct scsi_device, siblings);
564 : /* skip devices that we can't get a reference to */
565 0 : if (!scsi_device_get(next))
566 : break;
567 0 : next = NULL;
568 0 : list = list->next;
569 : }
570 0 : spin_unlock_irqrestore(shost->host_lock, flags);
571 :
572 0 : if (prev)
573 0 : scsi_device_put(prev);
574 0 : return next;
575 : }
576 : EXPORT_SYMBOL(__scsi_iterate_devices);
577 :
578 : /**
579 : * starget_for_each_device - helper to walk all devices of a target
580 : * @starget: target whose devices we want to iterate over.
581 : * @data: Opaque passed to each function call.
582 : * @fn: Function to call on each device
583 : *
584 : * This traverses over each device of @starget. The devices have
585 : * a reference that must be released by scsi_host_put when breaking
586 : * out of the loop.
587 : */
588 0 : void starget_for_each_device(struct scsi_target *starget, void *data,
589 : void (*fn)(struct scsi_device *, void *))
590 : {
591 0 : struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
592 0 : struct scsi_device *sdev;
593 :
594 0 : shost_for_each_device(sdev, shost) {
595 0 : if ((sdev->channel == starget->channel) &&
596 0 : (sdev->id == starget->id))
597 0 : fn(sdev, data);
598 : }
599 0 : }
600 : EXPORT_SYMBOL(starget_for_each_device);
601 :
602 : /**
603 : * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
604 : * @starget: target whose devices we want to iterate over.
605 : * @data: parameter for callback @fn()
606 : * @fn: callback function that is invoked for each device
607 : *
608 : * This traverses over each device of @starget. It does _not_
609 : * take a reference on the scsi_device, so the whole loop must be
610 : * protected by shost->host_lock.
611 : *
612 : * Note: The only reason why drivers would want to use this is because
613 : * they need to access the device list in irq context. Otherwise you
614 : * really want to use starget_for_each_device instead.
615 : **/
616 0 : void __starget_for_each_device(struct scsi_target *starget, void *data,
617 : void (*fn)(struct scsi_device *, void *))
618 : {
619 0 : struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
620 0 : struct scsi_device *sdev;
621 :
622 0 : __shost_for_each_device(sdev, shost) {
623 0 : if ((sdev->channel == starget->channel) &&
624 0 : (sdev->id == starget->id))
625 0 : fn(sdev, data);
626 : }
627 0 : }
628 : EXPORT_SYMBOL(__starget_for_each_device);
629 :
630 : /**
631 : * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
632 : * @starget: SCSI target pointer
633 : * @lun: SCSI Logical Unit Number
634 : *
635 : * Description: Looks up the scsi_device with the specified @lun for a given
636 : * @starget. The returned scsi_device does not have an additional
637 : * reference. You must hold the host's host_lock over this call and
638 : * any access to the returned scsi_device. A scsi_device in state
639 : * SDEV_DEL is skipped.
640 : *
641 : * Note: The only reason why drivers should use this is because
642 : * they need to access the device list in irq context. Otherwise you
643 : * really want to use scsi_device_lookup_by_target instead.
644 : **/
645 0 : struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
646 : u64 lun)
647 : {
648 0 : struct scsi_device *sdev;
649 :
650 0 : list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
651 0 : if (sdev->sdev_state == SDEV_DEL)
652 0 : continue;
653 0 : if (sdev->lun ==lun)
654 0 : return sdev;
655 : }
656 :
657 : return NULL;
658 : }
659 : EXPORT_SYMBOL(__scsi_device_lookup_by_target);
660 :
661 : /**
662 : * scsi_device_lookup_by_target - find a device given the target
663 : * @starget: SCSI target pointer
664 : * @lun: SCSI Logical Unit Number
665 : *
666 : * Description: Looks up the scsi_device with the specified @lun for a given
667 : * @starget. The returned scsi_device has an additional reference that
668 : * needs to be released with scsi_device_put once you're done with it.
669 : **/
670 0 : struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
671 : u64 lun)
672 : {
673 0 : struct scsi_device *sdev;
674 0 : struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
675 0 : unsigned long flags;
676 :
677 0 : spin_lock_irqsave(shost->host_lock, flags);
678 0 : sdev = __scsi_device_lookup_by_target(starget, lun);
679 0 : if (sdev && scsi_device_get(sdev))
680 0 : sdev = NULL;
681 0 : spin_unlock_irqrestore(shost->host_lock, flags);
682 :
683 0 : return sdev;
684 : }
685 : EXPORT_SYMBOL(scsi_device_lookup_by_target);
686 :
687 : /**
688 : * __scsi_device_lookup - find a device given the host (UNLOCKED)
689 : * @shost: SCSI host pointer
690 : * @channel: SCSI channel (zero if only one channel)
691 : * @id: SCSI target number (physical unit number)
692 : * @lun: SCSI Logical Unit Number
693 : *
694 : * Description: Looks up the scsi_device with the specified @channel, @id, @lun
695 : * for a given host. The returned scsi_device does not have an additional
696 : * reference. You must hold the host's host_lock over this call and any access
697 : * to the returned scsi_device.
698 : *
699 : * Note: The only reason why drivers would want to use this is because
700 : * they need to access the device list in irq context. Otherwise you
701 : * really want to use scsi_device_lookup instead.
702 : **/
703 0 : struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
704 : uint channel, uint id, u64 lun)
705 : {
706 0 : struct scsi_device *sdev;
707 :
708 0 : list_for_each_entry(sdev, &shost->__devices, siblings) {
709 0 : if (sdev->sdev_state == SDEV_DEL)
710 0 : continue;
711 0 : if (sdev->channel == channel && sdev->id == id &&
712 0 : sdev->lun ==lun)
713 0 : return sdev;
714 : }
715 :
716 : return NULL;
717 : }
718 : EXPORT_SYMBOL(__scsi_device_lookup);
719 :
720 : /**
721 : * scsi_device_lookup - find a device given the host
722 : * @shost: SCSI host pointer
723 : * @channel: SCSI channel (zero if only one channel)
724 : * @id: SCSI target number (physical unit number)
725 : * @lun: SCSI Logical Unit Number
726 : *
727 : * Description: Looks up the scsi_device with the specified @channel, @id, @lun
728 : * for a given host. The returned scsi_device has an additional reference that
729 : * needs to be released with scsi_device_put once you're done with it.
730 : **/
731 0 : struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
732 : uint channel, uint id, u64 lun)
733 : {
734 0 : struct scsi_device *sdev;
735 0 : unsigned long flags;
736 :
737 0 : spin_lock_irqsave(shost->host_lock, flags);
738 0 : sdev = __scsi_device_lookup(shost, channel, id, lun);
739 0 : if (sdev && scsi_device_get(sdev))
740 0 : sdev = NULL;
741 0 : spin_unlock_irqrestore(shost->host_lock, flags);
742 :
743 0 : return sdev;
744 : }
745 : EXPORT_SYMBOL(scsi_device_lookup);
746 :
747 : MODULE_DESCRIPTION("SCSI core");
748 : MODULE_LICENSE("GPL");
749 :
750 : module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
751 : MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
752 :
753 1 : static int __init init_scsi(void)
754 : {
755 1 : int error;
756 :
757 1 : error = scsi_init_procfs();
758 1 : if (error)
759 : goto cleanup_queue;
760 1 : error = scsi_init_devinfo();
761 1 : if (error)
762 0 : goto cleanup_procfs;
763 1 : error = scsi_init_hosts();
764 1 : if (error)
765 0 : goto cleanup_devlist;
766 1 : error = scsi_init_sysctl();
767 1 : if (error)
768 0 : goto cleanup_hosts;
769 1 : error = scsi_sysfs_register();
770 1 : if (error)
771 0 : goto cleanup_sysctl;
772 :
773 1 : scsi_netlink_init();
774 :
775 1 : printk(KERN_NOTICE "SCSI subsystem initialized\n");
776 1 : return 0;
777 :
778 0 : cleanup_sysctl:
779 0 : scsi_exit_sysctl();
780 0 : cleanup_hosts:
781 0 : scsi_exit_hosts();
782 0 : cleanup_devlist:
783 0 : scsi_exit_devinfo();
784 0 : cleanup_procfs:
785 0 : scsi_exit_procfs();
786 0 : cleanup_queue:
787 0 : scsi_exit_queue();
788 0 : printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
789 : -error);
790 0 : return error;
791 : }
792 :
793 0 : static void __exit exit_scsi(void)
794 : {
795 0 : scsi_netlink_exit();
796 0 : scsi_sysfs_unregister();
797 0 : scsi_exit_sysctl();
798 0 : scsi_exit_hosts();
799 0 : scsi_exit_devinfo();
800 0 : scsi_exit_procfs();
801 0 : scsi_exit_queue();
802 0 : }
803 :
804 : subsys_initcall(init_scsi);
805 : module_exit(exit_scsi);
|
