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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/*
2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
5 *
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
12 * Bug correction thanks go to :
13 * Rik Faith <faith@cs.unc.edu>
14 * Tommy Thorn <tthorn>
15 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
16 *
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
19 * enhancements.
20 *
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
23 *
24 * Added request_module("scsi_hostadapter") for kerneld:
25 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
26 * Bjorn Ekwall <bj0rn@blox.se>
27 * (changed to kmod)
28 *
29 * Major improvements to the timeout, abort, and reset processing,
30 * as well as performance modifications for large queue depths by
31 * Leonard N. Zubkoff <lnz@dandelion.com>
32 *
33 * Converted cli() code to spinlocks, Ingo Molnar
34 *
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
36 *
37 * out_of_space hacks, D. Gilbert (dpg) 990608
38 */
39
40#include <linux/module.h>
41#include <linux/moduleparam.h>
42#include <linux/kernel.h>
43#include <linux/timer.h>
44#include <linux/string.h>
45#include <linux/slab.h>
46#include <linux/blkdev.h>
47#include <linux/delay.h>
48#include <linux/init.h>
49#include <linux/completion.h>
50#include <linux/unistd.h>
51#include <linux/spinlock.h>
52#include <linux/kmod.h>
53#include <linux/interrupt.h>
54#include <linux/notifier.h>
55#include <linux/cpu.h>
56#include <linux/mutex.h>
57#include <linux/async.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
75static void scsi_done(struct scsi_cmnd *cmd);
76
77/*
78 * Definitions and constants.
79 */
80
81/*
82 * Note - the initial logging level can be set here to log events at boot time.
83 * After the system is up, you may enable logging via the /proc interface.
84 */
85unsigned int scsi_logging_level;
86#if defined(CONFIG_SCSI_LOGGING)
87EXPORT_SYMBOL(scsi_logging_level);
88#endif
89
90/* sd, scsi core and power management need to coordinate flushing async actions */
91ASYNC_DOMAIN(scsi_sd_probe_domain);
92EXPORT_SYMBOL(scsi_sd_probe_domain);
93
94/*
95 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
96 * asynchronous system resume operations. It is marked 'exclusive' to avoid
97 * being included in the async_synchronize_full() that is invoked by
98 * dpm_resume()
99 */
100ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
101EXPORT_SYMBOL(scsi_sd_pm_domain);
102
103/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
104 * You may not alter any existing entry (although adding new ones is
105 * encouraged once assigned by ANSI/INCITS T10
106 */
107static const char *const scsi_device_types[] = {
108 "Direct-Access ",
109 "Sequential-Access",
110 "Printer ",
111 "Processor ",
112 "WORM ",
113 "CD-ROM ",
114 "Scanner ",
115 "Optical Device ",
116 "Medium Changer ",
117 "Communications ",
118 "ASC IT8 ",
119 "ASC IT8 ",
120 "RAID ",
121 "Enclosure ",
122 "Direct-Access-RBC",
123 "Optical card ",
124 "Bridge controller",
125 "Object storage ",
126 "Automation/Drive ",
127};
128
129/**
130 * scsi_device_type - Return 17 char string indicating device type.
131 * @type: type number to look up
132 */
133
134const char * scsi_device_type(unsigned type)
135{
136 if (type == 0x1e)
137 return "Well-known LUN ";
138 if (type == 0x1f)
139 return "No Device ";
140 if (type >= ARRAY_SIZE(scsi_device_types))
141 return "Unknown ";
142 return scsi_device_types[type];
143}
144
145EXPORT_SYMBOL(scsi_device_type);
146
147struct scsi_host_cmd_pool {
148 struct kmem_cache *cmd_slab;
149 struct kmem_cache *sense_slab;
150 unsigned int users;
151 char *cmd_name;
152 char *sense_name;
153 unsigned int slab_flags;
154 gfp_t gfp_mask;
155};
156
157static struct scsi_host_cmd_pool scsi_cmd_pool = {
158 .cmd_name = "scsi_cmd_cache",
159 .sense_name = "scsi_sense_cache",
160 .slab_flags = SLAB_HWCACHE_ALIGN,
161};
162
163static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
164 .cmd_name = "scsi_cmd_cache(DMA)",
165 .sense_name = "scsi_sense_cache(DMA)",
166 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
167 .gfp_mask = __GFP_DMA,
168};
169
170static DEFINE_MUTEX(host_cmd_pool_mutex);
171
172/**
173 * scsi_host_free_command - internal function to release a command
174 * @shost: host to free the command for
175 * @cmd: command to release
176 *
177 * the command must previously have been allocated by
178 * scsi_host_alloc_command.
179 */
180static void
181scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
182{
183 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
184
185 if (cmd->prot_sdb)
186 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
187 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
188 kmem_cache_free(pool->cmd_slab, cmd);
189}
190
191/**
192 * scsi_host_alloc_command - internal function to allocate command
193 * @shost: SCSI host whose pool to allocate from
194 * @gfp_mask: mask for the allocation
195 *
196 * Returns a fully allocated command with sense buffer and protection
197 * data buffer (where applicable) or NULL on failure
198 */
199static struct scsi_cmnd *
200scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
201{
202 struct scsi_host_cmd_pool *pool = shost->cmd_pool;
203 struct scsi_cmnd *cmd;
204
205 cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
206 if (!cmd)
207 goto fail;
208
209 cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
210 gfp_mask | pool->gfp_mask);
211 if (!cmd->sense_buffer)
212 goto fail_free_cmd;
213
214 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
215 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
216 if (!cmd->prot_sdb)
217 goto fail_free_sense;
218 }
219
220 return cmd;
221
222fail_free_sense:
223 kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
224fail_free_cmd:
225 kmem_cache_free(pool->cmd_slab, cmd);
226fail:
227 return NULL;
228}
229
230/**
231 * __scsi_get_command - Allocate a struct scsi_cmnd
232 * @shost: host to transmit command
233 * @gfp_mask: allocation mask
234 *
235 * Description: allocate a struct scsi_cmd from host's slab, recycling from the
236 * host's free_list if necessary.
237 */
238struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
239{
240 struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
241
242 if (unlikely(!cmd)) {
243 unsigned long flags;
244
245 spin_lock_irqsave(&shost->free_list_lock, flags);
246 if (likely(!list_empty(&shost->free_list))) {
247 cmd = list_entry(shost->free_list.next,
248 struct scsi_cmnd, list);
249 list_del_init(&cmd->list);
250 }
251 spin_unlock_irqrestore(&shost->free_list_lock, flags);
252
253 if (cmd) {
254 void *buf, *prot;
255
256 buf = cmd->sense_buffer;
257 prot = cmd->prot_sdb;
258
259 memset(cmd, 0, sizeof(*cmd));
260
261 cmd->sense_buffer = buf;
262 cmd->prot_sdb = prot;
263 }
264 }
265
266 return cmd;
267}
268EXPORT_SYMBOL_GPL(__scsi_get_command);
269
270/**
271 * scsi_get_command - Allocate and setup a scsi command block
272 * @dev: parent scsi device
273 * @gfp_mask: allocator flags
274 *
275 * Returns: The allocated scsi command structure.
276 */
277struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
278{
279 struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
280 unsigned long flags;
281
282 if (unlikely(cmd == NULL))
283 return NULL;
284
285 cmd->device = dev;
286 INIT_LIST_HEAD(&cmd->list);
287 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
288 spin_lock_irqsave(&dev->list_lock, flags);
289 list_add_tail(&cmd->list, &dev->cmd_list);
290 spin_unlock_irqrestore(&dev->list_lock, flags);
291 cmd->jiffies_at_alloc = jiffies;
292 return cmd;
293}
294EXPORT_SYMBOL(scsi_get_command);
295
296/**
297 * __scsi_put_command - Free a struct scsi_cmnd
298 * @shost: dev->host
299 * @cmd: Command to free
300 */
301void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
302{
303 unsigned long flags;
304
305 if (unlikely(list_empty(&shost->free_list))) {
306 spin_lock_irqsave(&shost->free_list_lock, flags);
307 if (list_empty(&shost->free_list)) {
308 list_add(&cmd->list, &shost->free_list);
309 cmd = NULL;
310 }
311 spin_unlock_irqrestore(&shost->free_list_lock, flags);
312 }
313
314 if (likely(cmd != NULL))
315 scsi_host_free_command(shost, cmd);
316}
317EXPORT_SYMBOL(__scsi_put_command);
318
319/**
320 * scsi_put_command - Free a scsi command block
321 * @cmd: command block to free
322 *
323 * Returns: Nothing.
324 *
325 * Notes: The command must not belong to any lists.
326 */
327void scsi_put_command(struct scsi_cmnd *cmd)
328{
329 unsigned long flags;
330
331 /* serious error if the command hasn't come from a device list */
332 spin_lock_irqsave(&cmd->device->list_lock, flags);
333 BUG_ON(list_empty(&cmd->list));
334 list_del_init(&cmd->list);
335 spin_unlock_irqrestore(&cmd->device->list_lock, flags);
336
337 cancel_delayed_work(&cmd->abort_work);
338
339 __scsi_put_command(cmd->device->host, cmd);
340}
341EXPORT_SYMBOL(scsi_put_command);
342
343static struct scsi_host_cmd_pool *
344scsi_find_host_cmd_pool(struct Scsi_Host *shost)
345{
346 if (shost->hostt->cmd_size)
347 return shost->hostt->cmd_pool;
348 if (shost->unchecked_isa_dma)
349 return &scsi_cmd_dma_pool;
350 return &scsi_cmd_pool;
351}
352
353static void
354scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
355{
356 kfree(pool->sense_name);
357 kfree(pool->cmd_name);
358 kfree(pool);
359}
360
361static struct scsi_host_cmd_pool *
362scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
363{
364 struct scsi_host_template *hostt = shost->hostt;
365 struct scsi_host_cmd_pool *pool;
366
367 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
368 if (!pool)
369 return NULL;
370
371 pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
372 pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->name);
373 if (!pool->cmd_name || !pool->sense_name) {
374 scsi_free_host_cmd_pool(pool);
375 return NULL;
376 }
377
378 pool->slab_flags = SLAB_HWCACHE_ALIGN;
379 if (shost->unchecked_isa_dma) {
380 pool->slab_flags |= SLAB_CACHE_DMA;
381 pool->gfp_mask = __GFP_DMA;
382 }
383 return pool;
384}
385
386static struct scsi_host_cmd_pool *
387scsi_get_host_cmd_pool(struct Scsi_Host *shost)
388{
389 struct scsi_host_template *hostt = shost->hostt;
390 struct scsi_host_cmd_pool *retval = NULL, *pool;
391 size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
392
393 /*
394 * Select a command slab for this host and create it if not
395 * yet existent.
396 */
397 mutex_lock(&host_cmd_pool_mutex);
398 pool = scsi_find_host_cmd_pool(shost);
399 if (!pool) {
400 pool = scsi_alloc_host_cmd_pool(shost);
401 if (!pool)
402 goto out;
403 }
404
405 if (!pool->users) {
406 pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
407 pool->slab_flags, NULL);
408 if (!pool->cmd_slab)
409 goto out_free_pool;
410
411 pool->sense_slab = kmem_cache_create(pool->sense_name,
412 SCSI_SENSE_BUFFERSIZE, 0,
413 pool->slab_flags, NULL);
414 if (!pool->sense_slab)
415 goto out_free_slab;
416 }
417
418 pool->users++;
419 retval = pool;
420out:
421 mutex_unlock(&host_cmd_pool_mutex);
422 return retval;
423
424out_free_slab:
425 kmem_cache_destroy(pool->cmd_slab);
426out_free_pool:
427 if (hostt->cmd_size)
428 scsi_free_host_cmd_pool(pool);
429 goto out;
430}
431
432static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
433{
434 struct scsi_host_template *hostt = shost->hostt;
435 struct scsi_host_cmd_pool *pool;
436
437 mutex_lock(&host_cmd_pool_mutex);
438 pool = scsi_find_host_cmd_pool(shost);
439
440 /*
441 * This may happen if a driver has a mismatched get and put
442 * of the command pool; the driver should be implicated in
443 * the stack trace
444 */
445 BUG_ON(pool->users == 0);
446
447 if (!--pool->users) {
448 kmem_cache_destroy(pool->cmd_slab);
449 kmem_cache_destroy(pool->sense_slab);
450 if (hostt->cmd_size)
451 scsi_free_host_cmd_pool(pool);
452 }
453 mutex_unlock(&host_cmd_pool_mutex);
454}
455
456/**
457 * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
458 * @shost: host to allocate the freelist for.
459 *
460 * Description: The command freelist protects against system-wide out of memory
461 * deadlock by preallocating one SCSI command structure for each host, so the
462 * system can always write to a swap file on a device associated with that host.
463 *
464 * Returns: Nothing.
465 */
466int scsi_setup_command_freelist(struct Scsi_Host *shost)
467{
468 const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
469 struct scsi_cmnd *cmd;
470
471 spin_lock_init(&shost->free_list_lock);
472 INIT_LIST_HEAD(&shost->free_list);
473
474 shost->cmd_pool = scsi_get_host_cmd_pool(shost);
475 if (!shost->cmd_pool)
476 return -ENOMEM;
477
478 /*
479 * Get one backup command for this host.
480 */
481 cmd = scsi_host_alloc_command(shost, gfp_mask);
482 if (!cmd) {
483 scsi_put_host_cmd_pool(shost);
484 shost->cmd_pool = NULL;
485 return -ENOMEM;
486 }
487 list_add(&cmd->list, &shost->free_list);
488 return 0;
489}
490
491/**
492 * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
493 * @shost: host whose freelist is going to be destroyed
494 */
495void scsi_destroy_command_freelist(struct Scsi_Host *shost)
496{
497 /*
498 * If cmd_pool is NULL the free list was not initialized, so
499 * do not attempt to release resources.
500 */
501 if (!shost->cmd_pool)
502 return;
503
504 while (!list_empty(&shost->free_list)) {
505 struct scsi_cmnd *cmd;
506
507 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
508 list_del_init(&cmd->list);
509 scsi_host_free_command(shost, cmd);
510 }
511 shost->cmd_pool = NULL;
512 scsi_put_host_cmd_pool(shost);
513}
514
515#ifdef CONFIG_SCSI_LOGGING
516void scsi_log_send(struct scsi_cmnd *cmd)
517{
518 unsigned int level;
519
520 /*
521 * If ML QUEUE log level is greater than or equal to:
522 *
523 * 1: nothing (match completion)
524 *
525 * 2: log opcode + command of all commands
526 *
527 * 3: same as 2 plus dump cmd address
528 *
529 * 4: same as 3 plus dump extra junk
530 */
531 if (unlikely(scsi_logging_level)) {
532 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
533 SCSI_LOG_MLQUEUE_BITS);
534 if (level > 1) {
535 scmd_printk(KERN_INFO, cmd, "Send: ");
536 if (level > 2)
537 printk("0x%p ", cmd);
538 printk("\n");
539 scsi_print_command(cmd);
540 if (level > 3) {
541 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
542 " queuecommand 0x%p\n",
543 scsi_sglist(cmd), scsi_bufflen(cmd),
544 cmd->device->host->hostt->queuecommand);
545
546 }
547 }
548 }
549}
550
551void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
552{
553 unsigned int level;
554
555 /*
556 * If ML COMPLETE log level is greater than or equal to:
557 *
558 * 1: log disposition, result, opcode + command, and conditionally
559 * sense data for failures or non SUCCESS dispositions.
560 *
561 * 2: same as 1 but for all command completions.
562 *
563 * 3: same as 2 plus dump cmd address
564 *
565 * 4: same as 3 plus dump extra junk
566 */
567 if (unlikely(scsi_logging_level)) {
568 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
569 SCSI_LOG_MLCOMPLETE_BITS);
570 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
571 (level > 1)) {
572 scmd_printk(KERN_INFO, cmd, "Done: ");
573 if (level > 2)
574 printk("0x%p ", cmd);
575 /*
576 * Dump truncated values, so we usually fit within
577 * 80 chars.
578 */
579 switch (disposition) {
580 case SUCCESS:
581 printk("SUCCESS\n");
582 break;
583 case NEEDS_RETRY:
584 printk("RETRY\n");
585 break;
586 case ADD_TO_MLQUEUE:
587 printk("MLQUEUE\n");
588 break;
589 case FAILED:
590 printk("FAILED\n");
591 break;
592 case TIMEOUT_ERROR:
593 /*
594 * If called via scsi_times_out.
595 */
596 printk("TIMEOUT\n");
597 break;
598 default:
599 printk("UNKNOWN\n");
600 }
601 scsi_print_result(cmd);
602 scsi_print_command(cmd);
603 if (status_byte(cmd->result) & CHECK_CONDITION)
604 scsi_print_sense("", cmd);
605 if (level > 3)
606 scmd_printk(KERN_INFO, cmd,
607 "scsi host busy %d failed %d\n",
608 cmd->device->host->host_busy,
609 cmd->device->host->host_failed);
610 }
611 }
612}
613#endif
614
615/**
616 * scsi_cmd_get_serial - Assign a serial number to a command
617 * @host: the scsi host
618 * @cmd: command to assign serial number to
619 *
620 * Description: a serial number identifies a request for error recovery
621 * and debugging purposes. Protected by the Host_Lock of host.
622 */
623void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
624{
625 cmd->serial_number = host->cmd_serial_number++;
626 if (cmd->serial_number == 0)
627 cmd->serial_number = host->cmd_serial_number++;
628}
629EXPORT_SYMBOL(scsi_cmd_get_serial);
630
631/**
632 * scsi_dispatch_command - Dispatch a command to the low-level driver.
633 * @cmd: command block we are dispatching.
634 *
635 * Return: nonzero return request was rejected and device's queue needs to be
636 * plugged.
637 */
638int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
639{
640 struct Scsi_Host *host = cmd->device->host;
641 int rtn = 0;
642
643 atomic_inc(&cmd->device->iorequest_cnt);
644
645 /* check if the device is still usable */
646 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
647 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
648 * returns an immediate error upwards, and signals
649 * that the device is no longer present */
650 cmd->result = DID_NO_CONNECT << 16;
651 scsi_done(cmd);
652 /* return 0 (because the command has been processed) */
653 goto out;
654 }
655
656 /* Check to see if the scsi lld made this device blocked. */
657 if (unlikely(scsi_device_blocked(cmd->device))) {
658 /*
659 * in blocked state, the command is just put back on
660 * the device queue. The suspend state has already
661 * blocked the queue so future requests should not
662 * occur until the device transitions out of the
663 * suspend state.
664 */
665
666 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
667
668 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
669
670 /*
671 * NOTE: rtn is still zero here because we don't need the
672 * queue to be plugged on return (it's already stopped)
673 */
674 goto out;
675 }
676
677 /*
678 * If SCSI-2 or lower, store the LUN value in cmnd.
679 */
680 if (cmd->device->scsi_level <= SCSI_2 &&
681 cmd->device->scsi_level != SCSI_UNKNOWN) {
682 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
683 (cmd->device->lun << 5 & 0xe0);
684 }
685
686 scsi_log_send(cmd);
687
688 /*
689 * Before we queue this command, check if the command
690 * length exceeds what the host adapter can handle.
691 */
692 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
693 SCSI_LOG_MLQUEUE(3,
694 printk("queuecommand : command too long. "
695 "cdb_size=%d host->max_cmd_len=%d\n",
696 cmd->cmd_len, cmd->device->host->max_cmd_len));
697 cmd->result = (DID_ABORT << 16);
698
699 scsi_done(cmd);
700 goto out;
701 }
702
703 if (unlikely(host->shost_state == SHOST_DEL)) {
704 cmd->result = (DID_NO_CONNECT << 16);
705 scsi_done(cmd);
706 } else {
707 trace_scsi_dispatch_cmd_start(cmd);
708 cmd->scsi_done = scsi_done;
709 rtn = host->hostt->queuecommand(host, cmd);
710 }
711
712 if (rtn) {
713 trace_scsi_dispatch_cmd_error(cmd, rtn);
714 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
715 rtn != SCSI_MLQUEUE_TARGET_BUSY)
716 rtn = SCSI_MLQUEUE_HOST_BUSY;
717
718 scsi_queue_insert(cmd, rtn);
719
720 SCSI_LOG_MLQUEUE(3,
721 printk("queuecommand : request rejected\n"));
722 }
723
724 out:
725 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
726 return rtn;
727}
728
729/**
730 * scsi_done - Invoke completion on finished SCSI command.
731 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
732 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
733 *
734 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
735 * which regains ownership of the SCSI command (de facto) from a LLDD, and
736 * calls blk_complete_request() for further processing.
737 *
738 * This function is interrupt context safe.
739 */
740static void scsi_done(struct scsi_cmnd *cmd)
741{
742 trace_scsi_dispatch_cmd_done(cmd);
743 blk_complete_request(cmd->request);
744}
745
746/**
747 * scsi_finish_command - cleanup and pass command back to upper layer
748 * @cmd: the command
749 *
750 * Description: Pass command off to upper layer for finishing of I/O
751 * request, waking processes that are waiting on results,
752 * etc.
753 */
754void scsi_finish_command(struct scsi_cmnd *cmd)
755{
756 struct scsi_device *sdev = cmd->device;
757 struct scsi_target *starget = scsi_target(sdev);
758 struct Scsi_Host *shost = sdev->host;
759 struct scsi_driver *drv;
760 unsigned int good_bytes;
761
762 scsi_device_unbusy(sdev);
763
764 /*
765 * Clear the flags which say that the device/host is no longer
766 * capable of accepting new commands. These are set in scsi_queue.c
767 * for both the queue full condition on a device, and for a
768 * host full condition on the host.
769 *
770 * XXX(hch): What about locking?
771 */
772 shost->host_blocked = 0;
773 starget->target_blocked = 0;
774 sdev->device_blocked = 0;
775
776 /*
777 * If we have valid sense information, then some kind of recovery
778 * must have taken place. Make a note of this.
779 */
780 if (SCSI_SENSE_VALID(cmd))
781 cmd->result |= (DRIVER_SENSE << 24);
782
783 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
784 "Notifying upper driver of completion "
785 "(result %x)\n", cmd->result));
786
787 good_bytes = scsi_bufflen(cmd);
788 if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
789 int old_good_bytes = good_bytes;
790 drv = scsi_cmd_to_driver(cmd);
791 if (drv->done)
792 good_bytes = drv->done(cmd);
793 /*
794 * USB may not give sense identifying bad sector and
795 * simply return a residue instead, so subtract off the
796 * residue if drv->done() error processing indicates no
797 * change to the completion length.
798 */
799 if (good_bytes == old_good_bytes)
800 good_bytes -= scsi_get_resid(cmd);
801 }
802 scsi_io_completion(cmd, good_bytes);
803}
804EXPORT_SYMBOL(scsi_finish_command);
805
806/**
807 * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
808 * @sdev: SCSI Device in question
809 * @tagged: Do we use tagged queueing (non-0) or do we treat
810 * this device as an untagged device (0)
811 * @tags: Number of tags allowed if tagged queueing enabled,
812 * or number of commands the low level driver can
813 * queue up in non-tagged mode (as per cmd_per_lun).
814 *
815 * Returns: Nothing
816 *
817 * Lock Status: None held on entry
818 *
819 * Notes: Low level drivers may call this at any time and we will do
820 * the right thing depending on whether or not the device is
821 * currently active and whether or not it even has the
822 * command blocks built yet.
823 */
824void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
825{
826 unsigned long flags;
827
828 /*
829 * refuse to set tagged depth to an unworkable size
830 */
831 if (tags <= 0)
832 return;
833
834 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
835
836 /*
837 * Check to see if the queue is managed by the block layer.
838 * If it is, and we fail to adjust the depth, exit.
839 *
840 * Do not resize the tag map if it is a host wide share bqt,
841 * because the size should be the hosts's can_queue. If there
842 * is more IO than the LLD's can_queue (so there are not enuogh
843 * tags) request_fn's host queue ready check will handle it.
844 */
845 if (!sdev->host->bqt) {
846 if (blk_queue_tagged(sdev->request_queue) &&
847 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
848 goto out;
849 }
850
851 sdev->queue_depth = tags;
852 switch (tagged) {
853 case MSG_ORDERED_TAG:
854 sdev->ordered_tags = 1;
855 sdev->simple_tags = 1;
856 break;
857 case MSG_SIMPLE_TAG:
858 sdev->ordered_tags = 0;
859 sdev->simple_tags = 1;
860 break;
861 default:
862 sdev_printk(KERN_WARNING, sdev,
863 "scsi_adjust_queue_depth, bad queue type, "
864 "disabled\n");
865 case 0:
866 sdev->ordered_tags = sdev->simple_tags = 0;
867 sdev->queue_depth = tags;
868 break;
869 }
870 out:
871 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
872}
873EXPORT_SYMBOL(scsi_adjust_queue_depth);
874
875/**
876 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
877 * @sdev: SCSI Device in question
878 * @depth: Current number of outstanding SCSI commands on this device,
879 * not counting the one returned as QUEUE_FULL.
880 *
881 * Description: This function will track successive QUEUE_FULL events on a
882 * specific SCSI device to determine if and when there is a
883 * need to adjust the queue depth on the device.
884 *
885 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
886 * -1 - Drop back to untagged operation using host->cmd_per_lun
887 * as the untagged command depth
888 *
889 * Lock Status: None held on entry
890 *
891 * Notes: Low level drivers may call this at any time and we will do
892 * "The Right Thing." We are interrupt context safe.
893 */
894int scsi_track_queue_full(struct scsi_device *sdev, int depth)
895{
896
897 /*
898 * Don't let QUEUE_FULLs on the same
899 * jiffies count, they could all be from
900 * same event.
901 */
902 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
903 return 0;
904
905 sdev->last_queue_full_time = jiffies;
906 if (sdev->last_queue_full_depth != depth) {
907 sdev->last_queue_full_count = 1;
908 sdev->last_queue_full_depth = depth;
909 } else {
910 sdev->last_queue_full_count++;
911 }
912
913 if (sdev->last_queue_full_count <= 10)
914 return 0;
915 if (sdev->last_queue_full_depth < 8) {
916 /* Drop back to untagged */
917 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
918 return -1;
919 }
920
921 if (sdev->ordered_tags)
922 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
923 else
924 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
925 return depth;
926}
927EXPORT_SYMBOL(scsi_track_queue_full);
928
929/**
930 * scsi_vpd_inquiry - Request a device provide us with a VPD page
931 * @sdev: The device to ask
932 * @buffer: Where to put the result
933 * @page: Which Vital Product Data to return
934 * @len: The length of the buffer
935 *
936 * This is an internal helper function. You probably want to use
937 * scsi_get_vpd_page instead.
938 *
939 * Returns size of the vpd page on success or a negative error number.
940 */
941static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
942 u8 page, unsigned len)
943{
944 int result;
945 unsigned char cmd[16];
946
947 if (len < 4)
948 return -EINVAL;
949
950 cmd[0] = INQUIRY;
951 cmd[1] = 1; /* EVPD */
952 cmd[2] = page;
953 cmd[3] = len >> 8;
954 cmd[4] = len & 0xff;
955 cmd[5] = 0; /* Control byte */
956
957 /*
958 * I'm not convinced we need to try quite this hard to get VPD, but
959 * all the existing users tried this hard.
960 */
961 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
962 len, NULL, 30 * HZ, 3, NULL);
963 if (result)
964 return -EIO;
965
966 /* Sanity check that we got the page back that we asked for */
967 if (buffer[1] != page)
968 return -EIO;
969
970 return get_unaligned_be16(&buffer[2]) + 4;
971}
972
973/**
974 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
975 * @sdev: The device to ask
976 * @page: Which Vital Product Data to return
977 * @buf: where to store the VPD
978 * @buf_len: number of bytes in the VPD buffer area
979 *
980 * SCSI devices may optionally supply Vital Product Data. Each 'page'
981 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
982 * If the device supports this VPD page, this routine returns a pointer
983 * to a buffer containing the data from that page. The caller is
984 * responsible for calling kfree() on this pointer when it is no longer
985 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
986 */
987int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
988 int buf_len)
989{
990 int i, result;
991
992 if (sdev->skip_vpd_pages)
993 goto fail;
994
995 /* Ask for all the pages supported by this device */
996 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
997 if (result < 4)
998 goto fail;
999
1000 /* If the user actually wanted this page, we can skip the rest */
1001 if (page == 0)
1002 return 0;
1003
1004 for (i = 4; i < min(result, buf_len); i++)
1005 if (buf[i] == page)
1006 goto found;
1007
1008 if (i < result && i >= buf_len)
1009 /* ran off the end of the buffer, give us benefit of doubt */
1010 goto found;
1011 /* The device claims it doesn't support the requested page */
1012 goto fail;
1013
1014 found:
1015 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
1016 if (result < 0)
1017 goto fail;
1018
1019 return 0;
1020
1021 fail:
1022 return -EINVAL;
1023}
1024EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
1025
1026/**
1027 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
1028 * @sdev: The device to ask
1029 *
1030 * Attach the 'Device Identification' VPD page (0x83) and the
1031 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
1032 * structure. This information can be used to identify the device
1033 * uniquely.
1034 */
1035void scsi_attach_vpd(struct scsi_device *sdev)
1036{
1037 int result, i;
1038 int vpd_len = SCSI_VPD_PG_LEN;
1039 int pg80_supported = 0;
1040 int pg83_supported = 0;
1041 unsigned char *vpd_buf;
1042
1043 if (sdev->skip_vpd_pages)
1044 return;
1045retry_pg0:
1046 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1047 if (!vpd_buf)
1048 return;
1049
1050 /* Ask for all the pages supported by this device */
1051 result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
1052 if (result < 0) {
1053 kfree(vpd_buf);
1054 return;
1055 }
1056 if (result > vpd_len) {
1057 vpd_len = result;
1058 kfree(vpd_buf);
1059 goto retry_pg0;
1060 }
1061
1062 for (i = 4; i < result; i++) {
1063 if (vpd_buf[i] == 0x80)
1064 pg80_supported = 1;
1065 if (vpd_buf[i] == 0x83)
1066 pg83_supported = 1;
1067 }
1068 kfree(vpd_buf);
1069 vpd_len = SCSI_VPD_PG_LEN;
1070
1071 if (pg80_supported) {
1072retry_pg80:
1073 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1074 if (!vpd_buf)
1075 return;
1076
1077 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
1078 if (result < 0) {
1079 kfree(vpd_buf);
1080 return;
1081 }
1082 if (result > vpd_len) {
1083 vpd_len = result;
1084 kfree(vpd_buf);
1085 goto retry_pg80;
1086 }
1087 sdev->vpd_pg80_len = result;
1088 sdev->vpd_pg80 = vpd_buf;
1089 vpd_len = SCSI_VPD_PG_LEN;
1090 }
1091
1092 if (pg83_supported) {
1093retry_pg83:
1094 vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
1095 if (!vpd_buf)
1096 return;
1097
1098 result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
1099 if (result < 0) {
1100 kfree(vpd_buf);
1101 return;
1102 }
1103 if (result > vpd_len) {
1104 vpd_len = result;
1105 kfree(vpd_buf);
1106 goto retry_pg83;
1107 }
1108 sdev->vpd_pg83_len = result;
1109 sdev->vpd_pg83 = vpd_buf;
1110 }
1111}
1112
1113/**
1114 * scsi_report_opcode - Find out if a given command opcode is supported
1115 * @sdev: scsi device to query
1116 * @buffer: scratch buffer (must be at least 20 bytes long)
1117 * @len: length of buffer
1118 * @opcode: opcode for command to look up
1119 *
1120 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
1121 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
1122 * unsupported and 1 if the device claims to support the command.
1123 */
1124int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
1125 unsigned int len, unsigned char opcode)
1126{
1127 unsigned char cmd[16];
1128 struct scsi_sense_hdr sshdr;
1129 int result;
1130
1131 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
1132 return -EINVAL;
1133
1134 memset(cmd, 0, 16);
1135 cmd[0] = MAINTENANCE_IN;
1136 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
1137 cmd[2] = 1; /* One command format */
1138 cmd[3] = opcode;
1139 put_unaligned_be32(len, &cmd[6]);
1140 memset(buffer, 0, len);
1141
1142 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
1143 &sshdr, 30 * HZ, 3, NULL);
1144
1145 if (result && scsi_sense_valid(&sshdr) &&
1146 sshdr.sense_key == ILLEGAL_REQUEST &&
1147 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
1148 return -EINVAL;
1149
1150 if ((buffer[1] & 3) == 3) /* Command supported */
1151 return 1;
1152
1153 return 0;
1154}
1155EXPORT_SYMBOL(scsi_report_opcode);
1156
1157/**
1158 * scsi_device_get - get an additional reference to a scsi_device
1159 * @sdev: device to get a reference to
1160 *
1161 * Description: Gets a reference to the scsi_device and increments the use count
1162 * of the underlying LLDD module. You must hold host_lock of the
1163 * parent Scsi_Host or already have a reference when calling this.
1164 */
1165int scsi_device_get(struct scsi_device *sdev)
1166{
1167 if (sdev->sdev_state == SDEV_DEL)
1168 return -ENXIO;
1169 if (!get_device(&sdev->sdev_gendev))
1170 return -ENXIO;
1171 /* We can fail this if we're doing SCSI operations
1172 * from module exit (like cache flush) */
1173 try_module_get(sdev->host->hostt->module);
1174
1175 return 0;
1176}
1177EXPORT_SYMBOL(scsi_device_get);
1178
1179/**
1180 * scsi_device_put - release a reference to a scsi_device
1181 * @sdev: device to release a reference on.
1182 *
1183 * Description: Release a reference to the scsi_device and decrements the use
1184 * count of the underlying LLDD module. The device is freed once the last
1185 * user vanishes.
1186 */
1187void scsi_device_put(struct scsi_device *sdev)
1188{
1189#ifdef CONFIG_MODULE_UNLOAD
1190 struct module *module = sdev->host->hostt->module;
1191
1192 /* The module refcount will be zero if scsi_device_get()
1193 * was called from a module removal routine */
1194 if (module && module_refcount(module) != 0)
1195 module_put(module);
1196#endif
1197 put_device(&sdev->sdev_gendev);
1198}
1199EXPORT_SYMBOL(scsi_device_put);
1200
1201/* helper for shost_for_each_device, see that for documentation */
1202struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
1203 struct scsi_device *prev)
1204{
1205 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
1206 struct scsi_device *next = NULL;
1207 unsigned long flags;
1208
1209 spin_lock_irqsave(shost->host_lock, flags);
1210 while (list->next != &shost->__devices) {
1211 next = list_entry(list->next, struct scsi_device, siblings);
1212 /* skip devices that we can't get a reference to */
1213 if (!scsi_device_get(next))
1214 break;
1215 next = NULL;
1216 list = list->next;
1217 }
1218 spin_unlock_irqrestore(shost->host_lock, flags);
1219
1220 if (prev)
1221 scsi_device_put(prev);
1222 return next;
1223}
1224EXPORT_SYMBOL(__scsi_iterate_devices);
1225
1226/**
1227 * starget_for_each_device - helper to walk all devices of a target
1228 * @starget: target whose devices we want to iterate over.
1229 * @data: Opaque passed to each function call.
1230 * @fn: Function to call on each device
1231 *
1232 * This traverses over each device of @starget. The devices have
1233 * a reference that must be released by scsi_host_put when breaking
1234 * out of the loop.
1235 */
1236void starget_for_each_device(struct scsi_target *starget, void *data,
1237 void (*fn)(struct scsi_device *, void *))
1238{
1239 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1240 struct scsi_device *sdev;
1241
1242 shost_for_each_device(sdev, shost) {
1243 if ((sdev->channel == starget->channel) &&
1244 (sdev->id == starget->id))
1245 fn(sdev, data);
1246 }
1247}
1248EXPORT_SYMBOL(starget_for_each_device);
1249
1250/**
1251 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
1252 * @starget: target whose devices we want to iterate over.
1253 * @data: parameter for callback @fn()
1254 * @fn: callback function that is invoked for each device
1255 *
1256 * This traverses over each device of @starget. It does _not_
1257 * take a reference on the scsi_device, so the whole loop must be
1258 * protected by shost->host_lock.
1259 *
1260 * Note: The only reason why drivers would want to use this is because
1261 * they need to access the device list in irq context. Otherwise you
1262 * really want to use starget_for_each_device instead.
1263 **/
1264void __starget_for_each_device(struct scsi_target *starget, void *data,
1265 void (*fn)(struct scsi_device *, void *))
1266{
1267 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1268 struct scsi_device *sdev;
1269
1270 __shost_for_each_device(sdev, shost) {
1271 if ((sdev->channel == starget->channel) &&
1272 (sdev->id == starget->id))
1273 fn(sdev, data);
1274 }
1275}
1276EXPORT_SYMBOL(__starget_for_each_device);
1277
1278/**
1279 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
1280 * @starget: SCSI target pointer
1281 * @lun: SCSI Logical Unit Number
1282 *
1283 * Description: Looks up the scsi_device with the specified @lun for a given
1284 * @starget. The returned scsi_device does not have an additional
1285 * reference. You must hold the host's host_lock over this call and
1286 * any access to the returned scsi_device. A scsi_device in state
1287 * SDEV_DEL is skipped.
1288 *
1289 * Note: The only reason why drivers should use this is because
1290 * they need to access the device list in irq context. Otherwise you
1291 * really want to use scsi_device_lookup_by_target instead.
1292 **/
1293struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
1294 uint lun)
1295{
1296 struct scsi_device *sdev;
1297
1298 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
1299 if (sdev->sdev_state == SDEV_DEL)
1300 continue;
1301 if (sdev->lun ==lun)
1302 return sdev;
1303 }
1304
1305 return NULL;
1306}
1307EXPORT_SYMBOL(__scsi_device_lookup_by_target);
1308
1309/**
1310 * scsi_device_lookup_by_target - find a device given the target
1311 * @starget: SCSI target pointer
1312 * @lun: SCSI Logical Unit Number
1313 *
1314 * Description: Looks up the scsi_device with the specified @lun for a given
1315 * @starget. The returned scsi_device has an additional reference that
1316 * needs to be released with scsi_device_put once you're done with it.
1317 **/
1318struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
1319 uint lun)
1320{
1321 struct scsi_device *sdev;
1322 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1323 unsigned long flags;
1324
1325 spin_lock_irqsave(shost->host_lock, flags);
1326 sdev = __scsi_device_lookup_by_target(starget, lun);
1327 if (sdev && scsi_device_get(sdev))
1328 sdev = NULL;
1329 spin_unlock_irqrestore(shost->host_lock, flags);
1330
1331 return sdev;
1332}
1333EXPORT_SYMBOL(scsi_device_lookup_by_target);
1334
1335/**
1336 * __scsi_device_lookup - find a device given the host (UNLOCKED)
1337 * @shost: SCSI host pointer
1338 * @channel: SCSI channel (zero if only one channel)
1339 * @id: SCSI target number (physical unit number)
1340 * @lun: SCSI Logical Unit Number
1341 *
1342 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1343 * for a given host. The returned scsi_device does not have an additional
1344 * reference. You must hold the host's host_lock over this call and any access
1345 * to the returned scsi_device.
1346 *
1347 * Note: The only reason why drivers would want to use this is because
1348 * they need to access the device list in irq context. Otherwise you
1349 * really want to use scsi_device_lookup instead.
1350 **/
1351struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
1352 uint channel, uint id, uint lun)
1353{
1354 struct scsi_device *sdev;
1355
1356 list_for_each_entry(sdev, &shost->__devices, siblings) {
1357 if (sdev->channel == channel && sdev->id == id &&
1358 sdev->lun ==lun)
1359 return sdev;
1360 }
1361
1362 return NULL;
1363}
1364EXPORT_SYMBOL(__scsi_device_lookup);
1365
1366/**
1367 * scsi_device_lookup - find a device given the host
1368 * @shost: SCSI host pointer
1369 * @channel: SCSI channel (zero if only one channel)
1370 * @id: SCSI target number (physical unit number)
1371 * @lun: SCSI Logical Unit Number
1372 *
1373 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
1374 * for a given host. The returned scsi_device has an additional reference that
1375 * needs to be released with scsi_device_put once you're done with it.
1376 **/
1377struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1378 uint channel, uint id, uint lun)
1379{
1380 struct scsi_device *sdev;
1381 unsigned long flags;
1382
1383 spin_lock_irqsave(shost->host_lock, flags);
1384 sdev = __scsi_device_lookup(shost, channel, id, lun);
1385 if (sdev && scsi_device_get(sdev))
1386 sdev = NULL;
1387 spin_unlock_irqrestore(shost->host_lock, flags);
1388
1389 return sdev;
1390}
1391EXPORT_SYMBOL(scsi_device_lookup);
1392
1393MODULE_DESCRIPTION("SCSI core");
1394MODULE_LICENSE("GPL");
1395
1396module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1397MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1398
1399static int __init init_scsi(void)
1400{
1401 int error;
1402
1403 error = scsi_init_queue();
1404 if (error)
1405 return error;
1406 error = scsi_init_procfs();
1407 if (error)
1408 goto cleanup_queue;
1409 error = scsi_init_devinfo();
1410 if (error)
1411 goto cleanup_procfs;
1412 error = scsi_init_hosts();
1413 if (error)
1414 goto cleanup_devlist;
1415 error = scsi_init_sysctl();
1416 if (error)
1417 goto cleanup_hosts;
1418 error = scsi_sysfs_register();
1419 if (error)
1420 goto cleanup_sysctl;
1421
1422 scsi_netlink_init();
1423
1424 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1425 return 0;
1426
1427cleanup_sysctl:
1428 scsi_exit_sysctl();
1429cleanup_hosts:
1430 scsi_exit_hosts();
1431cleanup_devlist:
1432 scsi_exit_devinfo();
1433cleanup_procfs:
1434 scsi_exit_procfs();
1435cleanup_queue:
1436 scsi_exit_queue();
1437 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1438 -error);
1439 return error;
1440}
1441
1442static void __exit exit_scsi(void)
1443{
1444 scsi_netlink_exit();
1445 scsi_sysfs_unregister();
1446 scsi_exit_sysctl();
1447 scsi_exit_hosts();
1448 scsi_exit_devinfo();
1449 scsi_exit_procfs();
1450 scsi_exit_queue();
1451 async_unregister_domain(&scsi_sd_probe_domain);
1452}
1453
1454subsys_initcall(init_scsi);
1455module_exit(exit_scsi);