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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/unaligned.h>
59
60#include <scsi/scsi.h>
61#include <scsi/scsi_cmnd.h>
62#include <scsi/scsi_dbg.h>
63#include <scsi/scsi_device.h>
64#include <scsi/scsi_driver.h>
65#include <scsi/scsi_eh.h>
66#include <scsi/scsi_host.h>
67#include <scsi/scsi_tcq.h>
68
69#include "scsi_priv.h"
70#include "scsi_logging.h"
71
72#define CREATE_TRACE_POINTS
73#include <trace/events/scsi.h>
74
75/*
76 * Definitions and constants.
77 */
78
79/*
80 * Note - the initial logging level can be set here to log events at boot time.
81 * After the system is up, you may enable logging via the /proc interface.
82 */
83unsigned int scsi_logging_level;
84#if defined(CONFIG_SCSI_LOGGING)
85EXPORT_SYMBOL(scsi_logging_level);
86#endif
87
88#ifdef CONFIG_SCSI_LOGGING
89void scsi_log_send(struct scsi_cmnd *cmd)
90{
91 unsigned int level;
92
93 /*
94 * If ML QUEUE log level is greater than or equal to:
95 *
96 * 1: nothing (match completion)
97 *
98 * 2: log opcode + command of all commands + cmd address
99 *
100 * 3: same as 2
101 *
102 * 4: same as 3
103 */
104 if (unlikely(scsi_logging_level)) {
105 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
106 SCSI_LOG_MLQUEUE_BITS);
107 if (level > 1) {
108 scmd_printk(KERN_INFO, cmd,
109 "Send: scmd 0x%p\n", cmd);
110 scsi_print_command(cmd);
111 }
112 }
113}
114
115void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
116{
117 unsigned int level;
118
119 /*
120 * If ML COMPLETE log level is greater than or equal to:
121 *
122 * 1: log disposition, result, opcode + command, and conditionally
123 * sense data for failures or non SUCCESS dispositions.
124 *
125 * 2: same as 1 but for all command completions.
126 *
127 * 3: same as 2
128 *
129 * 4: same as 3 plus dump extra junk
130 */
131 if (unlikely(scsi_logging_level)) {
132 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
133 SCSI_LOG_MLCOMPLETE_BITS);
134 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
135 (level > 1)) {
136 scsi_print_result(cmd, "Done", disposition);
137 scsi_print_command(cmd);
138 if (scsi_status_is_check_condition(cmd->result))
139 scsi_print_sense(cmd);
140 if (level > 3)
141 scmd_printk(KERN_INFO, cmd,
142 "scsi host busy %d failed %d\n",
143 scsi_host_busy(cmd->device->host),
144 cmd->device->host->host_failed);
145 }
146 }
147}
148#endif
149
150/**
151 * scsi_finish_command - cleanup and pass command back to upper layer
152 * @cmd: the command
153 *
154 * Description: Pass command off to upper layer for finishing of I/O
155 * request, waking processes that are waiting on results,
156 * etc.
157 */
158void scsi_finish_command(struct scsi_cmnd *cmd)
159{
160 struct scsi_device *sdev = cmd->device;
161 struct scsi_target *starget = scsi_target(sdev);
162 struct Scsi_Host *shost = sdev->host;
163 struct scsi_driver *drv;
164 unsigned int good_bytes;
165
166 scsi_device_unbusy(sdev, cmd);
167
168 /*
169 * Clear the flags that say that the device/target/host is no longer
170 * capable of accepting new commands.
171 */
172 if (atomic_read(&shost->host_blocked))
173 atomic_set(&shost->host_blocked, 0);
174 if (atomic_read(&starget->target_blocked))
175 atomic_set(&starget->target_blocked, 0);
176 if (atomic_read(&sdev->device_blocked))
177 atomic_set(&sdev->device_blocked, 0);
178
179 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
180 "Notifying upper driver of completion "
181 "(result %x)\n", cmd->result));
182
183 good_bytes = scsi_bufflen(cmd);
184 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) {
185 int old_good_bytes = good_bytes;
186 drv = scsi_cmd_to_driver(cmd);
187 if (drv->done)
188 good_bytes = drv->done(cmd);
189 /*
190 * USB may not give sense identifying bad sector and
191 * simply return a residue instead, so subtract off the
192 * residue if drv->done() error processing indicates no
193 * change to the completion length.
194 */
195 if (good_bytes == old_good_bytes)
196 good_bytes -= scsi_get_resid(cmd);
197 }
198 scsi_io_completion(cmd, good_bytes);
199}
200
201
202/*
203 * 4096 is big enough for saturating fast SCSI LUNs.
204 */
205int scsi_device_max_queue_depth(struct scsi_device *sdev)
206{
207 return min_t(int, sdev->host->can_queue, 4096);
208}
209
210/**
211 * scsi_change_queue_depth - change a device's queue depth
212 * @sdev: SCSI Device in question
213 * @depth: number of commands allowed to be queued to the driver
214 *
215 * Sets the device queue depth and returns the new value.
216 */
217int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
218{
219 depth = min_t(int, depth, scsi_device_max_queue_depth(sdev));
220
221 if (depth > 0) {
222 sdev->queue_depth = depth;
223 wmb();
224 }
225
226 if (sdev->request_queue)
227 blk_set_queue_depth(sdev->request_queue, depth);
228
229 sbitmap_resize(&sdev->budget_map, sdev->queue_depth);
230
231 return sdev->queue_depth;
232}
233EXPORT_SYMBOL(scsi_change_queue_depth);
234
235/**
236 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
237 * @sdev: SCSI Device in question
238 * @depth: Current number of outstanding SCSI commands on this device,
239 * not counting the one returned as QUEUE_FULL.
240 *
241 * Description: This function will track successive QUEUE_FULL events on a
242 * specific SCSI device to determine if and when there is a
243 * need to adjust the queue depth on the device.
244 *
245 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
246 * -1 - Drop back to untagged operation using host->cmd_per_lun
247 * as the untagged command depth
248 *
249 * Lock Status: None held on entry
250 *
251 * Notes: Low level drivers may call this at any time and we will do
252 * "The Right Thing." We are interrupt context safe.
253 */
254int scsi_track_queue_full(struct scsi_device *sdev, int depth)
255{
256
257 /*
258 * Don't let QUEUE_FULLs on the same
259 * jiffies count, they could all be from
260 * same event.
261 */
262 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
263 return 0;
264
265 sdev->last_queue_full_time = jiffies;
266 if (sdev->last_queue_full_depth != depth) {
267 sdev->last_queue_full_count = 1;
268 sdev->last_queue_full_depth = depth;
269 } else {
270 sdev->last_queue_full_count++;
271 }
272
273 if (sdev->last_queue_full_count <= 10)
274 return 0;
275
276 return scsi_change_queue_depth(sdev, depth);
277}
278EXPORT_SYMBOL(scsi_track_queue_full);
279
280/**
281 * scsi_vpd_inquiry - Request a device provide us with a VPD page
282 * @sdev: The device to ask
283 * @buffer: Where to put the result
284 * @page: Which Vital Product Data to return
285 * @len: The length of the buffer
286 *
287 * This is an internal helper function. You probably want to use
288 * scsi_get_vpd_page instead.
289 *
290 * Returns size of the vpd page on success or a negative error number.
291 */
292static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
293 u8 page, unsigned len)
294{
295 int result;
296 unsigned char cmd[16];
297
298 if (len < 4)
299 return -EINVAL;
300
301 cmd[0] = INQUIRY;
302 cmd[1] = 1; /* EVPD */
303 cmd[2] = page;
304 cmd[3] = len >> 8;
305 cmd[4] = len & 0xff;
306 cmd[5] = 0; /* Control byte */
307
308 /*
309 * I'm not convinced we need to try quite this hard to get VPD, but
310 * all the existing users tried this hard.
311 */
312 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len,
313 30 * HZ, 3, NULL);
314 if (result)
315 return -EIO;
316
317 /*
318 * Sanity check that we got the page back that we asked for and that
319 * the page size is not 0.
320 */
321 if (buffer[1] != page)
322 return -EIO;
323
324 result = get_unaligned_be16(&buffer[2]);
325 if (!result)
326 return -EIO;
327
328 return result + 4;
329}
330
331enum scsi_vpd_parameters {
332 SCSI_VPD_HEADER_SIZE = 4,
333 SCSI_VPD_LIST_SIZE = 36,
334};
335
336static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
337{
338 unsigned char vpd[SCSI_VPD_LIST_SIZE] __aligned(4);
339 int result;
340
341 if (sdev->no_vpd_size)
342 return SCSI_DEFAULT_VPD_LEN;
343
344 /*
345 * Fetch the supported pages VPD and validate that the requested page
346 * number is present.
347 */
348 if (page != 0) {
349 result = scsi_vpd_inquiry(sdev, vpd, 0, sizeof(vpd));
350 if (result < SCSI_VPD_HEADER_SIZE)
351 return 0;
352
353 if (result > sizeof(vpd)) {
354 dev_warn_once(&sdev->sdev_gendev,
355 "%s: long VPD page 0 length: %d bytes\n",
356 __func__, result);
357 result = sizeof(vpd);
358 }
359
360 result -= SCSI_VPD_HEADER_SIZE;
361 if (!memchr(&vpd[SCSI_VPD_HEADER_SIZE], page, result))
362 return 0;
363 }
364 /*
365 * Fetch the VPD page header to find out how big the page
366 * is. This is done to prevent problems on legacy devices
367 * which can not handle allocation lengths as large as
368 * potentially requested by the caller.
369 */
370 result = scsi_vpd_inquiry(sdev, vpd, page, SCSI_VPD_HEADER_SIZE);
371 if (result < 0)
372 return 0;
373
374 if (result < SCSI_VPD_HEADER_SIZE) {
375 dev_warn_once(&sdev->sdev_gendev,
376 "%s: short VPD page 0x%02x length: %d bytes\n",
377 __func__, page, result);
378 return 0;
379 }
380
381 return result;
382}
383
384/**
385 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
386 * @sdev: The device to ask
387 * @page: Which Vital Product Data to return
388 * @buf: where to store the VPD
389 * @buf_len: number of bytes in the VPD buffer area
390 *
391 * SCSI devices may optionally supply Vital Product Data. Each 'page'
392 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
393 * If the device supports this VPD page, this routine fills @buf
394 * with the data from that page and return 0. If the VPD page is not
395 * supported or its content cannot be retrieved, -EINVAL is returned.
396 */
397int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
398 int buf_len)
399{
400 int result, vpd_len;
401
402 if (!scsi_device_supports_vpd(sdev))
403 return -EINVAL;
404
405 vpd_len = scsi_get_vpd_size(sdev, page);
406 if (vpd_len <= 0)
407 return -EINVAL;
408
409 vpd_len = min(vpd_len, buf_len);
410
411 /*
412 * Fetch the actual page. Since the appropriate size was reported
413 * by the device it is now safe to ask for something bigger.
414 */
415 memset(buf, 0, buf_len);
416 result = scsi_vpd_inquiry(sdev, buf, page, vpd_len);
417 if (result < 0)
418 return -EINVAL;
419 else if (result > vpd_len)
420 dev_warn_once(&sdev->sdev_gendev,
421 "%s: VPD page 0x%02x result %d > %d bytes\n",
422 __func__, page, result, vpd_len);
423
424 return 0;
425}
426EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
427
428/**
429 * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
430 * @sdev: The device to ask
431 * @page: Which Vital Product Data to return
432 *
433 * Returns %NULL upon failure.
434 */
435static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
436{
437 struct scsi_vpd *vpd_buf;
438 int vpd_len, result;
439
440 vpd_len = scsi_get_vpd_size(sdev, page);
441 if (vpd_len <= 0)
442 return NULL;
443
444retry_pg:
445 /*
446 * Fetch the actual page. Since the appropriate size was reported
447 * by the device it is now safe to ask for something bigger.
448 */
449 vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL);
450 if (!vpd_buf)
451 return NULL;
452
453 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len);
454 if (result < 0) {
455 kfree(vpd_buf);
456 return NULL;
457 }
458 if (result > vpd_len) {
459 dev_warn_once(&sdev->sdev_gendev,
460 "%s: VPD page 0x%02x result %d > %d bytes\n",
461 __func__, page, result, vpd_len);
462 vpd_len = result;
463 kfree(vpd_buf);
464 goto retry_pg;
465 }
466
467 vpd_buf->len = result;
468
469 return vpd_buf;
470}
471
472static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
473 struct scsi_vpd __rcu **sdev_vpd_buf)
474{
475 struct scsi_vpd *vpd_buf;
476
477 vpd_buf = scsi_get_vpd_buf(sdev, page);
478 if (!vpd_buf)
479 return;
480
481 mutex_lock(&sdev->inquiry_mutex);
482 vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf,
483 lockdep_is_held(&sdev->inquiry_mutex));
484 mutex_unlock(&sdev->inquiry_mutex);
485
486 if (vpd_buf)
487 kfree_rcu(vpd_buf, rcu);
488}
489
490/**
491 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
492 * @sdev: The device to ask
493 *
494 * Attach the 'Device Identification' VPD page (0x83) and the
495 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
496 * structure. This information can be used to identify the device
497 * uniquely.
498 */
499void scsi_attach_vpd(struct scsi_device *sdev)
500{
501 int i;
502 struct scsi_vpd *vpd_buf;
503
504 if (!scsi_device_supports_vpd(sdev))
505 return;
506
507 /* Ask for all the pages supported by this device */
508 vpd_buf = scsi_get_vpd_buf(sdev, 0);
509 if (!vpd_buf)
510 return;
511
512 for (i = 4; i < vpd_buf->len; i++) {
513 if (vpd_buf->data[i] == 0x0)
514 scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0);
515 if (vpd_buf->data[i] == 0x80)
516 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
517 if (vpd_buf->data[i] == 0x83)
518 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
519 if (vpd_buf->data[i] == 0x89)
520 scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89);
521 if (vpd_buf->data[i] == 0xb0)
522 scsi_update_vpd_page(sdev, 0xb0, &sdev->vpd_pgb0);
523 if (vpd_buf->data[i] == 0xb1)
524 scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1);
525 if (vpd_buf->data[i] == 0xb2)
526 scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2);
527 if (vpd_buf->data[i] == 0xb7)
528 scsi_update_vpd_page(sdev, 0xb7, &sdev->vpd_pgb7);
529 }
530 kfree(vpd_buf);
531}
532
533/**
534 * scsi_report_opcode - Find out if a given command is supported
535 * @sdev: scsi device to query
536 * @buffer: scratch buffer (must be at least 20 bytes long)
537 * @len: length of buffer
538 * @opcode: opcode for the command to look up
539 * @sa: service action for the command to look up
540 *
541 * Uses the REPORT SUPPORTED OPERATION CODES to check support for the
542 * command identified with @opcode and @sa. If the command does not
543 * have a service action, @sa must be 0. Returns -EINVAL if RSOC fails,
544 * 0 if the command is not supported and 1 if the device claims to
545 * support the command.
546 */
547int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
548 unsigned int len, unsigned char opcode,
549 unsigned short sa)
550{
551 unsigned char cmd[16];
552 struct scsi_sense_hdr sshdr;
553 int result, request_len;
554 const struct scsi_exec_args exec_args = {
555 .sshdr = &sshdr,
556 };
557
558 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
559 return -EINVAL;
560
561 /* RSOC header + size of command we are asking about */
562 request_len = 4 + COMMAND_SIZE(opcode);
563 if (request_len > len) {
564 dev_warn_once(&sdev->sdev_gendev,
565 "%s: len %u bytes, opcode 0x%02x needs %u\n",
566 __func__, len, opcode, request_len);
567 return -EINVAL;
568 }
569
570 memset(cmd, 0, 16);
571 cmd[0] = MAINTENANCE_IN;
572 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
573 if (!sa) {
574 cmd[2] = 1; /* One command format */
575 cmd[3] = opcode;
576 } else {
577 cmd[2] = 3; /* One command format with service action */
578 cmd[3] = opcode;
579 put_unaligned_be16(sa, &cmd[4]);
580 }
581 put_unaligned_be32(request_len, &cmd[6]);
582 memset(buffer, 0, len);
583
584 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer,
585 request_len, 30 * HZ, 3, &exec_args);
586 if (result < 0)
587 return result;
588 if (result && scsi_sense_valid(&sshdr) &&
589 sshdr.sense_key == ILLEGAL_REQUEST &&
590 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
591 return -EINVAL;
592
593 if ((buffer[1] & 3) == 3) /* Command supported */
594 return 1;
595
596 return 0;
597}
598EXPORT_SYMBOL(scsi_report_opcode);
599
600#define SCSI_CDL_CHECK_BUF_LEN 64
601
602static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa,
603 unsigned char *buf)
604{
605 int ret;
606 u8 cdlp;
607
608 /* Check operation code */
609 ret = scsi_report_opcode(sdev, buf, SCSI_CDL_CHECK_BUF_LEN, opcode, sa);
610 if (ret <= 0)
611 return false;
612
613 if ((buf[1] & 0x03) != 0x03)
614 return false;
615
616 /*
617 * See SPC-6, One_command parameter data format for
618 * REPORT SUPPORTED OPERATION CODES. We have the following cases
619 * depending on rwcdlp (buf[0] & 0x01) value:
620 * - rwcdlp == 0: then cdlp indicates support for the A mode page when
621 * it is equal to 1 and for the B mode page when it is
622 * equal to 2.
623 * - rwcdlp == 1: then cdlp indicates support for the T2A mode page
624 * when it is equal to 1 and for the T2B mode page when
625 * it is equal to 2.
626 * Overall, to detect support for command duration limits, we only need
627 * to check that cdlp is 1 or 2.
628 */
629 cdlp = (buf[1] & 0x18) >> 3;
630
631 return cdlp == 0x01 || cdlp == 0x02;
632}
633
634/**
635 * scsi_cdl_check - Check if a SCSI device supports Command Duration Limits
636 * @sdev: The device to check
637 */
638void scsi_cdl_check(struct scsi_device *sdev)
639{
640 bool cdl_supported;
641 unsigned char *buf;
642
643 /*
644 * Support for CDL was defined in SPC-5. Ignore devices reporting an
645 * lower SPC version. This also avoids problems with old drives choking
646 * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a
647 * service action specified, as done in scsi_cdl_check_cmd().
648 */
649 if (sdev->scsi_level < SCSI_SPC_5) {
650 sdev->cdl_supported = 0;
651 return;
652 }
653
654 buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL);
655 if (!buf) {
656 sdev->cdl_supported = 0;
657 return;
658 }
659
660 /* Check support for READ_16, WRITE_16, READ_32 and WRITE_32 commands */
661 cdl_supported =
662 scsi_cdl_check_cmd(sdev, READ_16, 0, buf) ||
663 scsi_cdl_check_cmd(sdev, WRITE_16, 0, buf) ||
664 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, READ_32, buf) ||
665 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, WRITE_32, buf);
666 if (cdl_supported) {
667 /*
668 * We have CDL support: force the use of READ16/WRITE16.
669 * READ32 and WRITE32 will be used for devices that support
670 * the T10_PI_TYPE2_PROTECTION protection type.
671 */
672 sdev->use_16_for_rw = 1;
673 sdev->use_10_for_rw = 0;
674
675 sdev->cdl_supported = 1;
676
677 /*
678 * If the device supports CDL, make sure that the current drive
679 * feature status is consistent with the user controlled
680 * cdl_enable state.
681 */
682 scsi_cdl_enable(sdev, sdev->cdl_enable);
683 } else {
684 sdev->cdl_supported = 0;
685 }
686
687 kfree(buf);
688}
689
690/**
691 * scsi_cdl_enable - Enable or disable a SCSI device supports for Command
692 * Duration Limits
693 * @sdev: The target device
694 * @enable: the target state
695 */
696int scsi_cdl_enable(struct scsi_device *sdev, bool enable)
697{
698 struct scsi_mode_data data;
699 struct scsi_sense_hdr sshdr;
700 struct scsi_vpd *vpd;
701 bool is_ata = false;
702 char buf[64];
703 int ret;
704
705 if (!sdev->cdl_supported)
706 return -EOPNOTSUPP;
707
708 rcu_read_lock();
709 vpd = rcu_dereference(sdev->vpd_pg89);
710 if (vpd)
711 is_ata = true;
712 rcu_read_unlock();
713
714 /*
715 * For ATA devices, CDL needs to be enabled with a SET FEATURES command.
716 */
717 if (is_ata) {
718 char *buf_data;
719 int len;
720
721 ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf),
722 5 * HZ, 3, &data, NULL);
723 if (ret)
724 return -EINVAL;
725
726 /* Enable CDL using the ATA feature page */
727 len = min_t(size_t, sizeof(buf),
728 data.length - data.header_length -
729 data.block_descriptor_length);
730 buf_data = buf + data.header_length +
731 data.block_descriptor_length;
732 if (enable)
733 buf_data[4] = 0x02;
734 else
735 buf_data[4] = 0;
736
737 ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3,
738 &data, &sshdr);
739 if (ret) {
740 if (ret > 0 && scsi_sense_valid(&sshdr))
741 scsi_print_sense_hdr(sdev,
742 dev_name(&sdev->sdev_gendev), &sshdr);
743 return ret;
744 }
745 }
746
747 sdev->cdl_enable = enable;
748
749 return 0;
750}
751
752/**
753 * scsi_device_get - get an additional reference to a scsi_device
754 * @sdev: device to get a reference to
755 *
756 * Description: Gets a reference to the scsi_device and increments the use count
757 * of the underlying LLDD module. You must hold host_lock of the
758 * parent Scsi_Host or already have a reference when calling this.
759 *
760 * This will fail if a device is deleted or cancelled, or when the LLD module
761 * is in the process of being unloaded.
762 */
763int scsi_device_get(struct scsi_device *sdev)
764{
765 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
766 goto fail;
767 if (!try_module_get(sdev->host->hostt->module))
768 goto fail;
769 if (!get_device(&sdev->sdev_gendev))
770 goto fail_put_module;
771 return 0;
772
773fail_put_module:
774 module_put(sdev->host->hostt->module);
775fail:
776 return -ENXIO;
777}
778EXPORT_SYMBOL(scsi_device_get);
779
780/**
781 * scsi_device_put - release a reference to a scsi_device
782 * @sdev: device to release a reference on.
783 *
784 * Description: Release a reference to the scsi_device and decrements the use
785 * count of the underlying LLDD module. The device is freed once the last
786 * user vanishes.
787 */
788void scsi_device_put(struct scsi_device *sdev)
789{
790 struct module *mod = sdev->host->hostt->module;
791
792 put_device(&sdev->sdev_gendev);
793 module_put(mod);
794}
795EXPORT_SYMBOL(scsi_device_put);
796
797/* helper for shost_for_each_device, see that for documentation */
798struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
799 struct scsi_device *prev)
800{
801 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
802 struct scsi_device *next = NULL;
803 unsigned long flags;
804
805 spin_lock_irqsave(shost->host_lock, flags);
806 while (list->next != &shost->__devices) {
807 next = list_entry(list->next, struct scsi_device, siblings);
808 /* skip devices that we can't get a reference to */
809 if (!scsi_device_get(next))
810 break;
811 next = NULL;
812 list = list->next;
813 }
814 spin_unlock_irqrestore(shost->host_lock, flags);
815
816 if (prev)
817 scsi_device_put(prev);
818 return next;
819}
820EXPORT_SYMBOL(__scsi_iterate_devices);
821
822/**
823 * starget_for_each_device - helper to walk all devices of a target
824 * @starget: target whose devices we want to iterate over.
825 * @data: Opaque passed to each function call.
826 * @fn: Function to call on each device
827 *
828 * This traverses over each device of @starget. The devices have
829 * a reference that must be released by scsi_host_put when breaking
830 * out of the loop.
831 */
832void starget_for_each_device(struct scsi_target *starget, void *data,
833 void (*fn)(struct scsi_device *, void *))
834{
835 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
836 struct scsi_device *sdev;
837
838 shost_for_each_device(sdev, shost) {
839 if ((sdev->channel == starget->channel) &&
840 (sdev->id == starget->id))
841 fn(sdev, data);
842 }
843}
844EXPORT_SYMBOL(starget_for_each_device);
845
846/**
847 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
848 * @starget: target whose devices we want to iterate over.
849 * @data: parameter for callback @fn()
850 * @fn: callback function that is invoked for each device
851 *
852 * This traverses over each device of @starget. It does _not_
853 * take a reference on the scsi_device, so the whole loop must be
854 * protected by shost->host_lock.
855 *
856 * Note: The only reason why drivers would want to use this is because
857 * they need to access the device list in irq context. Otherwise you
858 * really want to use starget_for_each_device instead.
859 **/
860void __starget_for_each_device(struct scsi_target *starget, void *data,
861 void (*fn)(struct scsi_device *, void *))
862{
863 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
864 struct scsi_device *sdev;
865
866 __shost_for_each_device(sdev, shost) {
867 if ((sdev->channel == starget->channel) &&
868 (sdev->id == starget->id))
869 fn(sdev, data);
870 }
871}
872EXPORT_SYMBOL(__starget_for_each_device);
873
874/**
875 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
876 * @starget: SCSI target pointer
877 * @lun: SCSI Logical Unit Number
878 *
879 * Description: Looks up the scsi_device with the specified @lun for a given
880 * @starget. The returned scsi_device does not have an additional
881 * reference. You must hold the host's host_lock over this call and
882 * any access to the returned scsi_device. A scsi_device in state
883 * SDEV_DEL is skipped.
884 *
885 * Note: The only reason why drivers should use this is because
886 * they need to access the device list in irq context. Otherwise you
887 * really want to use scsi_device_lookup_by_target instead.
888 **/
889struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
890 u64 lun)
891{
892 struct scsi_device *sdev;
893
894 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
895 if (sdev->sdev_state == SDEV_DEL)
896 continue;
897 if (sdev->lun ==lun)
898 return sdev;
899 }
900
901 return NULL;
902}
903EXPORT_SYMBOL(__scsi_device_lookup_by_target);
904
905/**
906 * scsi_device_lookup_by_target - find a device given the target
907 * @starget: SCSI target pointer
908 * @lun: SCSI Logical Unit Number
909 *
910 * Description: Looks up the scsi_device with the specified @lun for a given
911 * @starget. The returned scsi_device has an additional reference that
912 * needs to be released with scsi_device_put once you're done with it.
913 **/
914struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
915 u64 lun)
916{
917 struct scsi_device *sdev;
918 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
919 unsigned long flags;
920
921 spin_lock_irqsave(shost->host_lock, flags);
922 sdev = __scsi_device_lookup_by_target(starget, lun);
923 if (sdev && scsi_device_get(sdev))
924 sdev = NULL;
925 spin_unlock_irqrestore(shost->host_lock, flags);
926
927 return sdev;
928}
929EXPORT_SYMBOL(scsi_device_lookup_by_target);
930
931/**
932 * __scsi_device_lookup - find a device given the host (UNLOCKED)
933 * @shost: SCSI host pointer
934 * @channel: SCSI channel (zero if only one channel)
935 * @id: SCSI target number (physical unit number)
936 * @lun: SCSI Logical Unit Number
937 *
938 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
939 * for a given host. The returned scsi_device does not have an additional
940 * reference. You must hold the host's host_lock over this call and any access
941 * to the returned scsi_device.
942 *
943 * Note: The only reason why drivers would want to use this is because
944 * they need to access the device list in irq context. Otherwise you
945 * really want to use scsi_device_lookup instead.
946 **/
947struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
948 uint channel, uint id, u64 lun)
949{
950 struct scsi_device *sdev;
951
952 list_for_each_entry(sdev, &shost->__devices, siblings) {
953 if (sdev->sdev_state == SDEV_DEL)
954 continue;
955 if (sdev->channel == channel && sdev->id == id &&
956 sdev->lun ==lun)
957 return sdev;
958 }
959
960 return NULL;
961}
962EXPORT_SYMBOL(__scsi_device_lookup);
963
964/**
965 * scsi_device_lookup - find a device given the host
966 * @shost: SCSI host pointer
967 * @channel: SCSI channel (zero if only one channel)
968 * @id: SCSI target number (physical unit number)
969 * @lun: SCSI Logical Unit Number
970 *
971 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
972 * for a given host. The returned scsi_device has an additional reference that
973 * needs to be released with scsi_device_put once you're done with it.
974 **/
975struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
976 uint channel, uint id, u64 lun)
977{
978 struct scsi_device *sdev;
979 unsigned long flags;
980
981 spin_lock_irqsave(shost->host_lock, flags);
982 sdev = __scsi_device_lookup(shost, channel, id, lun);
983 if (sdev && scsi_device_get(sdev))
984 sdev = NULL;
985 spin_unlock_irqrestore(shost->host_lock, flags);
986
987 return sdev;
988}
989EXPORT_SYMBOL(scsi_device_lookup);
990
991MODULE_DESCRIPTION("SCSI core");
992MODULE_LICENSE("GPL");
993
994module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
995MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
996
997static int __init init_scsi(void)
998{
999 int error;
1000
1001 error = scsi_init_procfs();
1002 if (error)
1003 goto cleanup_queue;
1004 error = scsi_init_devinfo();
1005 if (error)
1006 goto cleanup_procfs;
1007 error = scsi_init_hosts();
1008 if (error)
1009 goto cleanup_devlist;
1010 error = scsi_init_sysctl();
1011 if (error)
1012 goto cleanup_hosts;
1013 error = scsi_sysfs_register();
1014 if (error)
1015 goto cleanup_sysctl;
1016
1017 scsi_netlink_init();
1018
1019 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1020 return 0;
1021
1022cleanup_sysctl:
1023 scsi_exit_sysctl();
1024cleanup_hosts:
1025 scsi_exit_hosts();
1026cleanup_devlist:
1027 scsi_exit_devinfo();
1028cleanup_procfs:
1029 scsi_exit_procfs();
1030cleanup_queue:
1031 scsi_exit_queue();
1032 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1033 -error);
1034 return error;
1035}
1036
1037static void __exit exit_scsi(void)
1038{
1039 scsi_netlink_exit();
1040 scsi_sysfs_unregister();
1041 scsi_exit_sysctl();
1042 scsi_exit_hosts();
1043 scsi_exit_devinfo();
1044 scsi_exit_procfs();
1045 scsi_exit_queue();
1046}
1047
1048subsys_initcall(init_scsi);
1049module_exit(exit_scsi);
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 */
84unsigned int scsi_logging_level;
85#if defined(CONFIG_SCSI_LOGGING)
86EXPORT_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 */
94ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
95EXPORT_SYMBOL(scsi_sd_pm_domain);
96
97#ifdef CONFIG_SCSI_LOGGING
98void 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
124void 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 */
167void scsi_finish_command(struct scsi_cmnd *cmd)
168{
169 struct scsi_device *sdev = cmd->device;
170 struct scsi_target *starget = scsi_target(sdev);
171 struct Scsi_Host *shost = sdev->host;
172 struct scsi_driver *drv;
173 unsigned int good_bytes;
174
175 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 if (atomic_read(&shost->host_blocked))
182 atomic_set(&shost->host_blocked, 0);
183 if (atomic_read(&starget->target_blocked))
184 atomic_set(&starget->target_blocked, 0);
185 if (atomic_read(&sdev->device_blocked))
186 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 if (SCSI_SENSE_VALID(cmd))
193 cmd->result |= (DRIVER_SENSE << 24);
194
195 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
196 "Notifying upper driver of completion "
197 "(result %x)\n", cmd->result));
198
199 good_bytes = scsi_bufflen(cmd);
200 if (!blk_rq_is_passthrough(cmd->request)) {
201 int old_good_bytes = good_bytes;
202 drv = scsi_cmd_to_driver(cmd);
203 if (drv->done)
204 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 if (good_bytes == old_good_bytes)
212 good_bytes -= scsi_get_resid(cmd);
213 }
214 scsi_io_completion(cmd, good_bytes);
215}
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 */
224int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
225{
226 if (depth > 0) {
227 sdev->queue_depth = depth;
228 wmb();
229 }
230
231 if (sdev->request_queue)
232 blk_set_queue_depth(sdev->request_queue, depth);
233
234 return sdev->queue_depth;
235}
236EXPORT_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 */
257int 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 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
266 return 0;
267
268 sdev->last_queue_full_time = jiffies;
269 if (sdev->last_queue_full_depth != depth) {
270 sdev->last_queue_full_count = 1;
271 sdev->last_queue_full_depth = depth;
272 } else {
273 sdev->last_queue_full_count++;
274 }
275
276 if (sdev->last_queue_full_count <= 10)
277 return 0;
278
279 return scsi_change_queue_depth(sdev, depth);
280}
281EXPORT_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 */
295static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
296 u8 page, unsigned len)
297{
298 int result;
299 unsigned char cmd[16];
300
301 if (len < 4)
302 return -EINVAL;
303
304 cmd[0] = INQUIRY;
305 cmd[1] = 1; /* EVPD */
306 cmd[2] = page;
307 cmd[3] = len >> 8;
308 cmd[4] = len & 0xff;
309 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 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
316 len, NULL, 30 * HZ, 3, NULL);
317 if (result)
318 return -EIO;
319
320 /* Sanity check that we got the page back that we asked for */
321 if (buffer[1] != page)
322 return -EIO;
323
324 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 */
341int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
342 int buf_len)
343{
344 int i, result;
345
346 if (sdev->skip_vpd_pages)
347 goto fail;
348
349 /* Ask for all the pages supported by this device */
350 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
351 if (result < 4)
352 goto fail;
353
354 /* If the user actually wanted this page, we can skip the rest */
355 if (page == 0)
356 return 0;
357
358 for (i = 4; i < min(result, buf_len); i++)
359 if (buf[i] == page)
360 goto found;
361
362 if (i < result && i >= buf_len)
363 /* ran off the end of the buffer, give us benefit of doubt */
364 goto found;
365 /* The device claims it doesn't support the requested page */
366 goto fail;
367
368 found:
369 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
370 if (result < 0)
371 goto fail;
372
373 return 0;
374
375 fail:
376 return -EINVAL;
377}
378EXPORT_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 */
387static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
388{
389 struct scsi_vpd *vpd_buf;
390 int vpd_len = SCSI_VPD_PG_LEN, result;
391
392retry_pg:
393 vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL);
394 if (!vpd_buf)
395 return NULL;
396
397 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len);
398 if (result < 0) {
399 kfree(vpd_buf);
400 return NULL;
401 }
402 if (result > vpd_len) {
403 vpd_len = result;
404 kfree(vpd_buf);
405 goto retry_pg;
406 }
407
408 vpd_buf->len = result;
409
410 return vpd_buf;
411}
412
413static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
414 struct scsi_vpd __rcu **sdev_vpd_buf)
415{
416 struct scsi_vpd *vpd_buf;
417
418 vpd_buf = scsi_get_vpd_buf(sdev, page);
419 if (!vpd_buf)
420 return;
421
422 mutex_lock(&sdev->inquiry_mutex);
423 vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf,
424 lockdep_is_held(&sdev->inquiry_mutex));
425 mutex_unlock(&sdev->inquiry_mutex);
426
427 if (vpd_buf)
428 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 */
440void scsi_attach_vpd(struct scsi_device *sdev)
441{
442 int i;
443 struct scsi_vpd *vpd_buf;
444
445 if (!scsi_device_supports_vpd(sdev))
446 return;
447
448 /* Ask for all the pages supported by this device */
449 vpd_buf = scsi_get_vpd_buf(sdev, 0);
450 if (!vpd_buf)
451 return;
452
453 for (i = 4; i < vpd_buf->len; i++) {
454 if (vpd_buf->data[i] == 0x0)
455 scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0);
456 if (vpd_buf->data[i] == 0x80)
457 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
458 if (vpd_buf->data[i] == 0x83)
459 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
460 if (vpd_buf->data[i] == 0x89)
461 scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89);
462 }
463 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 */
477int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
478 unsigned int len, unsigned char opcode)
479{
480 unsigned char cmd[16];
481 struct scsi_sense_hdr sshdr;
482 int result;
483
484 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
485 return -EINVAL;
486
487 memset(cmd, 0, 16);
488 cmd[0] = MAINTENANCE_IN;
489 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
490 cmd[2] = 1; /* One command format */
491 cmd[3] = opcode;
492 put_unaligned_be32(len, &cmd[6]);
493 memset(buffer, 0, len);
494
495 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
496 &sshdr, 30 * HZ, 3, NULL);
497
498 if (result && scsi_sense_valid(&sshdr) &&
499 sshdr.sense_key == ILLEGAL_REQUEST &&
500 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
501 return -EINVAL;
502
503 if ((buffer[1] & 3) == 3) /* Command supported */
504 return 1;
505
506 return 0;
507}
508EXPORT_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 */
521int scsi_device_get(struct scsi_device *sdev)
522{
523 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
524 goto fail;
525 if (!get_device(&sdev->sdev_gendev))
526 goto fail;
527 if (!try_module_get(sdev->host->hostt->module))
528 goto fail_put_device;
529 return 0;
530
531fail_put_device:
532 put_device(&sdev->sdev_gendev);
533fail:
534 return -ENXIO;
535}
536EXPORT_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 */
546void scsi_device_put(struct scsi_device *sdev)
547{
548 module_put(sdev->host->hostt->module);
549 put_device(&sdev->sdev_gendev);
550}
551EXPORT_SYMBOL(scsi_device_put);
552
553/* helper for shost_for_each_device, see that for documentation */
554struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
555 struct scsi_device *prev)
556{
557 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
558 struct scsi_device *next = NULL;
559 unsigned long flags;
560
561 spin_lock_irqsave(shost->host_lock, flags);
562 while (list->next != &shost->__devices) {
563 next = list_entry(list->next, struct scsi_device, siblings);
564 /* skip devices that we can't get a reference to */
565 if (!scsi_device_get(next))
566 break;
567 next = NULL;
568 list = list->next;
569 }
570 spin_unlock_irqrestore(shost->host_lock, flags);
571
572 if (prev)
573 scsi_device_put(prev);
574 return next;
575}
576EXPORT_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 */
588void starget_for_each_device(struct scsi_target *starget, void *data,
589 void (*fn)(struct scsi_device *, void *))
590{
591 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
592 struct scsi_device *sdev;
593
594 shost_for_each_device(sdev, shost) {
595 if ((sdev->channel == starget->channel) &&
596 (sdev->id == starget->id))
597 fn(sdev, data);
598 }
599}
600EXPORT_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 **/
616void __starget_for_each_device(struct scsi_target *starget, void *data,
617 void (*fn)(struct scsi_device *, void *))
618{
619 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
620 struct scsi_device *sdev;
621
622 __shost_for_each_device(sdev, shost) {
623 if ((sdev->channel == starget->channel) &&
624 (sdev->id == starget->id))
625 fn(sdev, data);
626 }
627}
628EXPORT_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 **/
645struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
646 u64 lun)
647{
648 struct scsi_device *sdev;
649
650 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
651 if (sdev->sdev_state == SDEV_DEL)
652 continue;
653 if (sdev->lun ==lun)
654 return sdev;
655 }
656
657 return NULL;
658}
659EXPORT_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 **/
670struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
671 u64 lun)
672{
673 struct scsi_device *sdev;
674 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
675 unsigned long flags;
676
677 spin_lock_irqsave(shost->host_lock, flags);
678 sdev = __scsi_device_lookup_by_target(starget, lun);
679 if (sdev && scsi_device_get(sdev))
680 sdev = NULL;
681 spin_unlock_irqrestore(shost->host_lock, flags);
682
683 return sdev;
684}
685EXPORT_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 **/
703struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
704 uint channel, uint id, u64 lun)
705{
706 struct scsi_device *sdev;
707
708 list_for_each_entry(sdev, &shost->__devices, siblings) {
709 if (sdev->sdev_state == SDEV_DEL)
710 continue;
711 if (sdev->channel == channel && sdev->id == id &&
712 sdev->lun ==lun)
713 return sdev;
714 }
715
716 return NULL;
717}
718EXPORT_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 **/
731struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
732 uint channel, uint id, u64 lun)
733{
734 struct scsi_device *sdev;
735 unsigned long flags;
736
737 spin_lock_irqsave(shost->host_lock, flags);
738 sdev = __scsi_device_lookup(shost, channel, id, lun);
739 if (sdev && scsi_device_get(sdev))
740 sdev = NULL;
741 spin_unlock_irqrestore(shost->host_lock, flags);
742
743 return sdev;
744}
745EXPORT_SYMBOL(scsi_device_lookup);
746
747MODULE_DESCRIPTION("SCSI core");
748MODULE_LICENSE("GPL");
749
750module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
751MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
752
753static int __init init_scsi(void)
754{
755 int error;
756
757 error = scsi_init_procfs();
758 if (error)
759 goto cleanup_queue;
760 error = scsi_init_devinfo();
761 if (error)
762 goto cleanup_procfs;
763 error = scsi_init_hosts();
764 if (error)
765 goto cleanup_devlist;
766 error = scsi_init_sysctl();
767 if (error)
768 goto cleanup_hosts;
769 error = scsi_sysfs_register();
770 if (error)
771 goto cleanup_sysctl;
772
773 scsi_netlink_init();
774
775 printk(KERN_NOTICE "SCSI subsystem initialized\n");
776 return 0;
777
778cleanup_sysctl:
779 scsi_exit_sysctl();
780cleanup_hosts:
781 scsi_exit_hosts();
782cleanup_devlist:
783 scsi_exit_devinfo();
784cleanup_procfs:
785 scsi_exit_procfs();
786cleanup_queue:
787 scsi_exit_queue();
788 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
789 -error);
790 return error;
791}
792
793static void __exit exit_scsi(void)
794{
795 scsi_netlink_exit();
796 scsi_sysfs_unregister();
797 scsi_exit_sysctl();
798 scsi_exit_hosts();
799 scsi_exit_devinfo();
800 scsi_exit_procfs();
801 scsi_exit_queue();
802}
803
804subsys_initcall(init_scsi);
805module_exit(exit_scsi);