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