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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#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>
Arjan van de Ven0b950672006-01-11 13:16:10 +010056#include <linux/mutex.h>
Dan Williams2955b472012-07-09 19:33:25 -070057#include <linux/async.h>
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -040058#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#include <scsi/scsi.h>
61#include <scsi/scsi_cmnd.h>
62#include <scsi/scsi_dbg.h>
63#include <scsi/scsi_device.h>
Linus Torvalds7b3d9542008-01-06 10:17:12 -080064#include <scsi/scsi_driver.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#include <scsi/scsi_eh.h>
66#include <scsi/scsi_host.h>
67#include <scsi/scsi_tcq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69#include "scsi_priv.h"
70#include "scsi_logging.h"
71
Kei Tokunagabf816232010-04-01 20:41:40 +090072#define CREATE_TRACE_POINTS
73#include <trace/events/scsi.h>
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075/*
76 * Definitions and constants.
77 */
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 * 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
James Bottomleyea80dad2012-06-06 14:54:13 +090088/* sd, scsi core and power management need to coordinate flushing async actions */
Dan Williams2955b472012-07-09 19:33:25 -070089ASYNC_DOMAIN(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070090EXPORT_SYMBOL(scsi_sd_probe_domain);
Dan Williamsa7a20d12012-03-22 17:05:11 -070091
Dan Williams3c31b522014-04-10 15:30:35 -070092/*
93 * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
94 * asynchronous system resume operations. It is marked 'exclusive' to avoid
95 * being included in the async_synchronize_full() that is invoked by
96 * dpm_resume()
97 */
98ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
99EXPORT_SYMBOL(scsi_sd_pm_domain);
100
Rob Landleyeb448202007-11-03 13:30:39 -0500101/**
102 * scsi_put_command - Free a scsi command block
103 * @cmd: command block to free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 *
105 * Returns: Nothing.
106 *
107 * Notes: The command must not belong to any lists.
108 */
109void scsi_put_command(struct scsi_cmnd *cmd)
110{
Bart Van Assche2dd6fb52017-06-02 14:21:58 -0700111 scsi_del_cmd_from_list(cmd);
Bart Van Asschefcc95a72014-06-02 11:50:52 +0200112 BUG_ON(delayed_work_pending(&cmd->abort_work));
FUJITA Tomonoride25deb2008-01-16 13:32:17 +0900113}
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115#ifdef CONFIG_SCSI_LOGGING
116void scsi_log_send(struct scsi_cmnd *cmd)
117{
118 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120 /*
121 * If ML QUEUE log level is greater than or equal to:
122 *
123 * 1: nothing (match completion)
124 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200125 * 2: log opcode + command of all commands + cmd address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200127 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 *
Hannes Reineckea4a6afb2015-01-08 07:43:49 +0100129 * 4: same as 3
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 */
131 if (unlikely(scsi_logging_level)) {
132 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
133 SCSI_LOG_MLQUEUE_BITS);
134 if (level > 1) {
Hannes Reineckec11c0042014-10-24 14:27:01 +0200135 scmd_printk(KERN_INFO, cmd,
136 "Send: scmd 0x%p\n", cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 scsi_print_command(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 }
139 }
140}
141
142void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
143{
144 unsigned int level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146 /*
147 * If ML COMPLETE log level is greater than or equal to:
148 *
149 * 1: log disposition, result, opcode + command, and conditionally
150 * sense data for failures or non SUCCESS dispositions.
151 *
152 * 2: same as 1 but for all command completions.
153 *
Hannes Reineckec11c0042014-10-24 14:27:01 +0200154 * 3: same as 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 *
156 * 4: same as 3 plus dump extra junk
157 */
158 if (unlikely(scsi_logging_level)) {
159 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
160 SCSI_LOG_MLCOMPLETE_BITS);
161 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
162 (level > 1)) {
Hannes Reinecke026f8da2015-01-08 07:43:47 +0100163 scsi_print_result(cmd, "Done", disposition);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 scsi_print_command(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500165 if (status_byte(cmd->result) & CHECK_CONDITION)
Hannes Reinecked811b842014-10-24 14:26:45 +0200166 scsi_print_sense(cmd);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500167 if (level > 3)
168 scmd_printk(KERN_INFO, cmd,
169 "scsi host busy %d failed %d\n",
Christoph Hellwig74665012014-01-22 15:29:29 +0100170 atomic_read(&cmd->device->host->host_busy),
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500171 cmd->device->host->host_failed);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 }
173 }
174}
175#endif
176
Rob Landleyeb448202007-11-03 13:30:39 -0500177/**
178 * scsi_cmd_get_serial - Assign a serial number to a command
179 * @host: the scsi host
180 * @cmd: command to assign serial number to
181 *
182 * Description: a serial number identifies a request for error recovery
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 * and debugging purposes. Protected by the Host_Lock of host.
184 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500185void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
187 cmd->serial_number = host->cmd_serial_number++;
188 if (cmd->serial_number == 0)
189 cmd->serial_number = host->cmd_serial_number++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
Jeff Garzikf2812332010-11-16 02:10:29 -0500191EXPORT_SYMBOL(scsi_cmd_get_serial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Rob Landleyeb448202007-11-03 13:30:39 -0500193/**
Rob Landleyeb448202007-11-03 13:30:39 -0500194 * scsi_finish_command - cleanup and pass command back to upper layer
195 * @cmd: the command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 *
Rob Landleyeb448202007-11-03 13:30:39 -0500197 * Description: Pass command off to upper layer for finishing of I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 * request, waking processes that are waiting on results,
199 * etc.
200 */
201void scsi_finish_command(struct scsi_cmnd *cmd)
202{
203 struct scsi_device *sdev = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500204 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 struct Scsi_Host *shost = sdev->host;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800206 struct scsi_driver *drv;
207 unsigned int good_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 scsi_device_unbusy(sdev);
210
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100211 /*
212 * Clear the flags that say that the device/target/host is no longer
213 * capable of accepting new commands.
214 */
215 if (atomic_read(&shost->host_blocked))
216 atomic_set(&shost->host_blocked, 0);
217 if (atomic_read(&starget->target_blocked))
218 atomic_set(&starget->target_blocked, 0);
219 if (atomic_read(&sdev->device_blocked))
220 atomic_set(&sdev->device_blocked, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 /*
223 * If we have valid sense information, then some kind of recovery
224 * must have taken place. Make a note of this.
225 */
226 if (SCSI_SENSE_VALID(cmd))
227 cmd->result |= (DRIVER_SENSE << 24);
228
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400229 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
230 "Notifying upper driver of completion "
231 "(result %x)\n", cmd->result));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
FUJITA Tomonorif18573a2008-04-11 12:56:52 +0200233 good_bytes = scsi_bufflen(cmd);
Christoph Hellwig57292b52017-01-31 16:57:29 +0100234 if (!blk_rq_is_passthrough(cmd->request)) {
James Bottomley427e59f2008-03-08 18:24:17 -0600235 int old_good_bytes = good_bytes;
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800236 drv = scsi_cmd_to_driver(cmd);
237 if (drv->done)
238 good_bytes = drv->done(cmd);
James Bottomley427e59f2008-03-08 18:24:17 -0600239 /*
240 * USB may not give sense identifying bad sector and
241 * simply return a residue instead, so subtract off the
242 * residue if drv->done() error processing indicates no
243 * change to the completion length.
244 */
245 if (good_bytes == old_good_bytes)
246 good_bytes -= scsi_get_resid(cmd);
Linus Torvalds7b3d9542008-01-06 10:17:12 -0800247 }
248 scsi_io_completion(cmd, good_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
Rob Landleyeb448202007-11-03 13:30:39 -0500251/**
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100252 * scsi_change_queue_depth - change a device's queue depth
Rob Landleyeb448202007-11-03 13:30:39 -0500253 * @sdev: SCSI Device in question
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100254 * @depth: number of commands allowed to be queued to the driver
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 *
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100256 * Sets the device queue depth and returns the new value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 */
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100258int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
Christoph Hellwig64d513ac2015-10-08 09:28:04 +0100260 if (depth > 0) {
261 sdev->queue_depth = depth;
262 wmb();
Mike Christie885ace92008-07-11 19:50:32 -0500263 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Jens Axboed278d4a2016-03-30 10:21:08 -0600265 if (sdev->request_queue)
266 blk_set_queue_depth(sdev->request_queue, depth);
267
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100268 return sdev->queue_depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269}
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100270EXPORT_SYMBOL(scsi_change_queue_depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
Rob Landleyeb448202007-11-03 13:30:39 -0500272/**
273 * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
274 * @sdev: SCSI Device in question
275 * @depth: Current number of outstanding SCSI commands on this device,
276 * not counting the one returned as QUEUE_FULL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 *
Rob Landleyeb448202007-11-03 13:30:39 -0500278 * Description: This function will track successive QUEUE_FULL events on a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 * specific SCSI device to determine if and when there is a
280 * need to adjust the queue depth on the device.
281 *
Rob Landleyeb448202007-11-03 13:30:39 -0500282 * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 * -1 - Drop back to untagged operation using host->cmd_per_lun
284 * as the untagged command depth
285 *
286 * Lock Status: None held on entry
287 *
288 * Notes: Low level drivers may call this at any time and we will do
289 * "The Right Thing." We are interrupt context safe.
290 */
291int scsi_track_queue_full(struct scsi_device *sdev, int depth)
292{
Vasu Dev4a840672009-10-22 15:46:33 -0700293
294 /*
295 * Don't let QUEUE_FULLs on the same
296 * jiffies count, they could all be from
297 * same event.
298 */
299 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 return 0;
301
Vasu Dev4a840672009-10-22 15:46:33 -0700302 sdev->last_queue_full_time = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 if (sdev->last_queue_full_depth != depth) {
304 sdev->last_queue_full_count = 1;
305 sdev->last_queue_full_depth = depth;
306 } else {
307 sdev->last_queue_full_count++;
308 }
309
310 if (sdev->last_queue_full_count <= 10)
311 return 0;
Christoph Hellwig609aa222014-10-30 11:54:58 +0100312
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100313 return scsi_change_queue_depth(sdev, depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314}
315EXPORT_SYMBOL(scsi_track_queue_full);
316
317/**
Matthew Wilcox881a2562008-12-31 13:12:46 -0500318 * scsi_vpd_inquiry - Request a device provide us with a VPD page
319 * @sdev: The device to ask
320 * @buffer: Where to put the result
321 * @page: Which Vital Product Data to return
322 * @len: The length of the buffer
323 *
324 * This is an internal helper function. You probably want to use
325 * scsi_get_vpd_page instead.
326 *
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100327 * Returns size of the vpd page on success or a negative error number.
Matthew Wilcox881a2562008-12-31 13:12:46 -0500328 */
329static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
330 u8 page, unsigned len)
331{
332 int result;
333 unsigned char cmd[16];
334
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100335 if (len < 4)
336 return -EINVAL;
337
Matthew Wilcox881a2562008-12-31 13:12:46 -0500338 cmd[0] = INQUIRY;
339 cmd[1] = 1; /* EVPD */
340 cmd[2] = page;
341 cmd[3] = len >> 8;
342 cmd[4] = len & 0xff;
343 cmd[5] = 0; /* Control byte */
344
345 /*
346 * I'm not convinced we need to try quite this hard to get VPD, but
347 * all the existing users tried this hard.
348 */
349 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
James Bottomley95a36392009-08-11 10:59:09 -0500350 len, NULL, 30 * HZ, 3, NULL);
Matthew Wilcox881a2562008-12-31 13:12:46 -0500351 if (result)
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100352 return -EIO;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500353
354 /* Sanity check that we got the page back that we asked for */
355 if (buffer[1] != page)
356 return -EIO;
357
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100358 return get_unaligned_be16(&buffer[2]) + 4;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500359}
360
361/**
362 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device
363 * @sdev: The device to ask
364 * @page: Which Vital Product Data to return
Randy Dunlap786f8ba2010-02-28 17:32:45 -0800365 * @buf: where to store the VPD
366 * @buf_len: number of bytes in the VPD buffer area
Matthew Wilcox881a2562008-12-31 13:12:46 -0500367 *
368 * SCSI devices may optionally supply Vital Product Data. Each 'page'
369 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
370 * If the device supports this VPD page, this routine returns a pointer
371 * to a buffer containing the data from that page. The caller is
372 * responsible for calling kfree() on this pointer when it is no longer
373 * needed. If we cannot retrieve the VPD page this routine returns %NULL.
374 */
James Bottomleye3deec02009-11-03 12:33:07 -0600375int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
376 int buf_len)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500377{
378 int i, result;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500379
Martin K. Petersen7562523e2013-07-30 22:58:34 -0400380 if (sdev->skip_vpd_pages)
381 goto fail;
382
Matthew Wilcox881a2562008-12-31 13:12:46 -0500383 /* Ask for all the pages supported by this device */
James Bottomleye3deec02009-11-03 12:33:07 -0600384 result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100385 if (result < 4)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500386 goto fail;
387
388 /* If the user actually wanted this page, we can skip the rest */
389 if (page == 0)
Martin K. Petersen16d3ea22010-09-10 01:20:27 -0400390 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500391
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100392 for (i = 4; i < min(result, buf_len); i++)
393 if (buf[i] == page)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500394 goto found;
James Bottomleye3deec02009-11-03 12:33:07 -0600395
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100396 if (i < result && i >= buf_len)
James Bottomleye3deec02009-11-03 12:33:07 -0600397 /* ran off the end of the buffer, give us benefit of doubt */
398 goto found;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500399 /* The device claims it doesn't support the requested page */
400 goto fail;
401
402 found:
James Bottomleye3deec02009-11-03 12:33:07 -0600403 result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
Hannes Reineckebc8945d2014-03-15 09:51:48 +0100404 if (result < 0)
Matthew Wilcox881a2562008-12-31 13:12:46 -0500405 goto fail;
406
James Bottomleye3deec02009-11-03 12:33:07 -0600407 return 0;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500408
409 fail:
James Bottomleye3deec02009-11-03 12:33:07 -0600410 return -EINVAL;
Matthew Wilcox881a2562008-12-31 13:12:46 -0500411}
412EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
413
414/**
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700415 * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
416 * @sdev: The device to ask
417 * @page: Which Vital Product Data to return
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700418 *
419 * Returns %NULL upon failure.
420 */
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700421static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700422{
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700423 struct scsi_vpd *vpd_buf;
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700424 int vpd_len = SCSI_VPD_PG_LEN, result;
425
426retry_pg:
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700427 vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL);
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700428 if (!vpd_buf)
429 return NULL;
430
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700431 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len);
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700432 if (result < 0) {
433 kfree(vpd_buf);
434 return NULL;
435 }
436 if (result > vpd_len) {
437 vpd_len = result;
438 kfree(vpd_buf);
439 goto retry_pg;
440 }
441
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700442 vpd_buf->len = result;
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700443
444 return vpd_buf;
445}
446
447static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700448 struct scsi_vpd __rcu **sdev_vpd_buf)
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700449{
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700450 struct scsi_vpd *vpd_buf;
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700451
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700452 vpd_buf = scsi_get_vpd_buf(sdev, page);
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700453 if (!vpd_buf)
454 return;
455
456 mutex_lock(&sdev->inquiry_mutex);
457 rcu_swap_protected(*sdev_vpd_buf, vpd_buf,
458 lockdep_is_held(&sdev->inquiry_mutex));
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700459 mutex_unlock(&sdev->inquiry_mutex);
460
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700461 if (vpd_buf)
462 kfree_rcu(vpd_buf, rcu);
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700463}
464
465/**
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100466 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
467 * @sdev: The device to ask
468 *
469 * Attach the 'Device Identification' VPD page (0x83) and the
470 * 'Unit Serial Number' VPD page (0x80) to a SCSI device
471 * structure. This information can be used to identify the device
472 * uniquely.
473 */
474void scsi_attach_vpd(struct scsi_device *sdev)
475{
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700476 int i;
477 struct scsi_vpd *vpd_buf;
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100478
Hannes Reinecke5ddfe082016-04-01 08:57:36 +0200479 if (!scsi_device_supports_vpd(sdev))
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100480 return;
Hannes Reinecke5ddfe082016-04-01 08:57:36 +0200481
Bart Van Assche1e3f7202017-08-29 08:50:12 -0700482 /* Ask for all the pages supported by this device */
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700483 vpd_buf = scsi_get_vpd_buf(sdev, 0);
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100484 if (!vpd_buf)
485 return;
486
Bart Van Asscheccf1e002017-08-29 08:50:13 -0700487 for (i = 4; i < vpd_buf->len; i++) {
488 if (vpd_buf->data[i] == 0x80)
489 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
490 if (vpd_buf->data[i] == 0x83)
491 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100492 }
493 kfree(vpd_buf);
Hannes Reineckeb3ae8782014-03-15 09:51:49 +0100494}
495
496/**
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400497 * scsi_report_opcode - Find out if a given command opcode is supported
498 * @sdev: scsi device to query
499 * @buffer: scratch buffer (must be at least 20 bytes long)
500 * @len: length of buffer
501 * @opcode: opcode for command to look up
502 *
503 * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400504 * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
505 * unsupported and 1 if the device claims to support the command.
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400506 */
507int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
508 unsigned int len, unsigned char opcode)
509{
510 unsigned char cmd[16];
511 struct scsi_sense_hdr sshdr;
512 int result;
513
514 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400515 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400516
517 memset(cmd, 0, 16);
518 cmd[0] = MAINTENANCE_IN;
519 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
520 cmd[2] = 1; /* One command format */
521 cmd[3] = opcode;
522 put_unaligned_be32(len, &cmd[6]);
523 memset(buffer, 0, len);
524
525 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
526 &sshdr, 30 * HZ, 3, NULL);
527
528 if (result && scsi_sense_valid(&sshdr) &&
529 sshdr.sense_key == ILLEGAL_REQUEST &&
530 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
Martin K. Petersen66c28f92013-06-06 22:15:55 -0400531 return -EINVAL;
Martin K. Petersen3c6bdae2012-09-18 12:19:30 -0400532
533 if ((buffer[1] & 3) == 3) /* Command supported */
534 return 1;
535
536 return 0;
537}
538EXPORT_SYMBOL(scsi_report_opcode);
539
540/**
Rob Landleyeb448202007-11-03 13:30:39 -0500541 * scsi_device_get - get an additional reference to a scsi_device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 * @sdev: device to get a reference to
543 *
Rob Landleyeb448202007-11-03 13:30:39 -0500544 * Description: Gets a reference to the scsi_device and increments the use count
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 * of the underlying LLDD module. You must hold host_lock of the
546 * parent Scsi_Host or already have a reference when calling this.
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100547 *
548 * This will fail if a device is deleted or cancelled, or when the LLD module
549 * is in the process of being unloaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 */
551int scsi_device_get(struct scsi_device *sdev)
552{
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100553 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
554 goto fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 if (!get_device(&sdev->sdev_gendev))
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100556 goto fail;
557 if (!try_module_get(sdev->host->hostt->module))
558 goto fail_put_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 return 0;
Christoph Hellwigcff549e2015-02-02 14:01:26 +0100560
561fail_put_device:
562 put_device(&sdev->sdev_gendev);
563fail:
564 return -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565}
566EXPORT_SYMBOL(scsi_device_get);
567
568/**
569 * scsi_device_put - release a reference to a scsi_device
570 * @sdev: device to release a reference on.
571 *
Rob Landleyeb448202007-11-03 13:30:39 -0500572 * Description: Release a reference to the scsi_device and decrements the use
573 * count of the underlying LLDD module. The device is freed once the last
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 * user vanishes.
575 */
576void scsi_device_put(struct scsi_device *sdev)
577{
Rusty Russelldc4515e2015-01-23 13:22:47 +1030578 module_put(sdev->host->hostt->module);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 put_device(&sdev->sdev_gendev);
580}
581EXPORT_SYMBOL(scsi_device_put);
582
Rob Landleyeb448202007-11-03 13:30:39 -0500583/* helper for shost_for_each_device, see that for documentation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
585 struct scsi_device *prev)
586{
587 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
588 struct scsi_device *next = NULL;
589 unsigned long flags;
590
591 spin_lock_irqsave(shost->host_lock, flags);
592 while (list->next != &shost->__devices) {
593 next = list_entry(list->next, struct scsi_device, siblings);
594 /* skip devices that we can't get a reference to */
595 if (!scsi_device_get(next))
596 break;
597 next = NULL;
598 list = list->next;
599 }
600 spin_unlock_irqrestore(shost->host_lock, flags);
601
602 if (prev)
603 scsi_device_put(prev);
604 return next;
605}
606EXPORT_SYMBOL(__scsi_iterate_devices);
607
608/**
609 * starget_for_each_device - helper to walk all devices of a target
610 * @starget: target whose devices we want to iterate over.
Rob Landleyeb448202007-11-03 13:30:39 -0500611 * @data: Opaque passed to each function call.
612 * @fn: Function to call on each device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 *
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800614 * This traverses over each device of @starget. The devices have
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 * a reference that must be released by scsi_host_put when breaking
616 * out of the loop.
617 */
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800618void starget_for_each_device(struct scsi_target *starget, void *data,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 void (*fn)(struct scsi_device *, void *))
620{
621 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
622 struct scsi_device *sdev;
623
624 shost_for_each_device(sdev, shost) {
625 if ((sdev->channel == starget->channel) &&
626 (sdev->id == starget->id))
627 fn(sdev, data);
628 }
629}
630EXPORT_SYMBOL(starget_for_each_device);
631
632/**
Randy Dunlap14f501a2008-02-03 15:06:36 -0800633 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800634 * @starget: target whose devices we want to iterate over.
Randy Dunlap14f501a2008-02-03 15:06:36 -0800635 * @data: parameter for callback @fn()
636 * @fn: callback function that is invoked for each device
Maciej W. Rozycki522939d2007-12-10 15:49:31 -0800637 *
638 * This traverses over each device of @starget. It does _not_
639 * take a reference on the scsi_device, so the whole loop must be
640 * protected by shost->host_lock.
641 *
642 * Note: The only reason why drivers would want to use this is because
643 * they need to access the device list in irq context. Otherwise you
644 * really want to use starget_for_each_device instead.
645 **/
646void __starget_for_each_device(struct scsi_target *starget, void *data,
647 void (*fn)(struct scsi_device *, void *))
648{
649 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
650 struct scsi_device *sdev;
651
652 __shost_for_each_device(sdev, shost) {
653 if ((sdev->channel == starget->channel) &&
654 (sdev->id == starget->id))
655 fn(sdev, data);
656 }
657}
658EXPORT_SYMBOL(__starget_for_each_device);
659
660/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
662 * @starget: SCSI target pointer
663 * @lun: SCSI Logical Unit Number
664 *
Rob Landleyeb448202007-11-03 13:30:39 -0500665 * Description: Looks up the scsi_device with the specified @lun for a given
666 * @starget. The returned scsi_device does not have an additional
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 * reference. You must hold the host's host_lock over this call and
Hannes Reinecke32aeef62009-01-13 16:50:37 +0100668 * any access to the returned scsi_device. A scsi_device in state
669 * SDEV_DEL is skipped.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -0800671 * Note: The only reason why drivers should use this is because
Rob Landleyeb448202007-11-03 13:30:39 -0500672 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 * really want to use scsi_device_lookup_by_target instead.
674 **/
675struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +0200676 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677{
678 struct scsi_device *sdev;
679
680 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
Hannes Reinecke32aeef62009-01-13 16:50:37 +0100681 if (sdev->sdev_state == SDEV_DEL)
682 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 if (sdev->lun ==lun)
684 return sdev;
685 }
686
687 return NULL;
688}
689EXPORT_SYMBOL(__scsi_device_lookup_by_target);
690
691/**
692 * scsi_device_lookup_by_target - find a device given the target
693 * @starget: SCSI target pointer
694 * @lun: SCSI Logical Unit Number
695 *
Bartlomiej Zolnierkiewicz477e6082009-04-27 20:54:22 +0200696 * Description: Looks up the scsi_device with the specified @lun for a given
697 * @starget. The returned scsi_device has an additional reference that
Rob Landleyeb448202007-11-03 13:30:39 -0500698 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 **/
700struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +0200701 u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702{
703 struct scsi_device *sdev;
704 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
705 unsigned long flags;
706
707 spin_lock_irqsave(shost->host_lock, flags);
708 sdev = __scsi_device_lookup_by_target(starget, lun);
709 if (sdev && scsi_device_get(sdev))
710 sdev = NULL;
711 spin_unlock_irqrestore(shost->host_lock, flags);
712
713 return sdev;
714}
715EXPORT_SYMBOL(scsi_device_lookup_by_target);
716
717/**
Rob Landleyeb448202007-11-03 13:30:39 -0500718 * __scsi_device_lookup - find a device given the host (UNLOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 * @shost: SCSI host pointer
720 * @channel: SCSI channel (zero if only one channel)
Rob Landleyeb448202007-11-03 13:30:39 -0500721 * @id: SCSI target number (physical unit number)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 * @lun: SCSI Logical Unit Number
723 *
Rob Landleyeb448202007-11-03 13:30:39 -0500724 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
725 * for a given host. The returned scsi_device does not have an additional
726 * reference. You must hold the host's host_lock over this call and any access
727 * to the returned scsi_device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 *
729 * Note: The only reason why drivers would want to use this is because
Rob Landleyeb448202007-11-03 13:30:39 -0500730 * they need to access the device list in irq context. Otherwise you
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 * really want to use scsi_device_lookup instead.
732 **/
733struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +0200734 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735{
736 struct scsi_device *sdev;
737
738 list_for_each_entry(sdev, &shost->__devices, siblings) {
Zhou Zhengping4ff7adc2017-04-28 17:43:04 +0800739 if (sdev->sdev_state == SDEV_DEL)
740 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 if (sdev->channel == channel && sdev->id == id &&
742 sdev->lun ==lun)
743 return sdev;
744 }
745
746 return NULL;
747}
748EXPORT_SYMBOL(__scsi_device_lookup);
749
750/**
751 * scsi_device_lookup - find a device given the host
752 * @shost: SCSI host pointer
753 * @channel: SCSI channel (zero if only one channel)
754 * @id: SCSI target number (physical unit number)
755 * @lun: SCSI Logical Unit Number
756 *
Rob Landleyeb448202007-11-03 13:30:39 -0500757 * Description: Looks up the scsi_device with the specified @channel, @id, @lun
758 * for a given host. The returned scsi_device has an additional reference that
759 * needs to be released with scsi_device_put once you're done with it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 **/
761struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
Hannes Reinecke9cb78c12014-06-25 15:27:36 +0200762 uint channel, uint id, u64 lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763{
764 struct scsi_device *sdev;
765 unsigned long flags;
766
767 spin_lock_irqsave(shost->host_lock, flags);
768 sdev = __scsi_device_lookup(shost, channel, id, lun);
769 if (sdev && scsi_device_get(sdev))
770 sdev = NULL;
771 spin_unlock_irqrestore(shost->host_lock, flags);
772
773 return sdev;
774}
775EXPORT_SYMBOL(scsi_device_lookup);
776
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777MODULE_DESCRIPTION("SCSI core");
778MODULE_LICENSE("GPL");
779
780module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
781MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
782
Christoph Hellwigcbe7dfa2017-08-13 19:44:22 +0200783#ifdef CONFIG_SCSI_MQ_DEFAULT
Christoph Hellwig24c20f12014-09-30 16:43:46 +0200784bool scsi_use_blk_mq = true;
Christoph Hellwigcbe7dfa2017-08-13 19:44:22 +0200785#else
786bool scsi_use_blk_mq = false;
787#endif
Christoph Hellwigd2852032014-01-17 12:06:53 +0100788module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790static int __init init_scsi(void)
791{
Jens Axboe9bf09c232006-09-30 20:31:11 +0200792 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
794 error = scsi_init_queue();
795 if (error)
796 return error;
797 error = scsi_init_procfs();
798 if (error)
799 goto cleanup_queue;
800 error = scsi_init_devinfo();
801 if (error)
802 goto cleanup_procfs;
803 error = scsi_init_hosts();
804 if (error)
805 goto cleanup_devlist;
806 error = scsi_init_sysctl();
807 if (error)
808 goto cleanup_hosts;
809 error = scsi_sysfs_register();
810 if (error)
811 goto cleanup_sysctl;
812
James Smart84314fd2006-08-18 17:30:09 -0400813 scsi_netlink_init();
814
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 printk(KERN_NOTICE "SCSI subsystem initialized\n");
816 return 0;
817
818cleanup_sysctl:
819 scsi_exit_sysctl();
820cleanup_hosts:
821 scsi_exit_hosts();
822cleanup_devlist:
823 scsi_exit_devinfo();
824cleanup_procfs:
825 scsi_exit_procfs();
826cleanup_queue:
827 scsi_exit_queue();
828 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
829 -error);
830 return error;
831}
832
833static void __exit exit_scsi(void)
834{
James Smart84314fd2006-08-18 17:30:09 -0400835 scsi_netlink_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 scsi_sysfs_unregister();
837 scsi_exit_sysctl();
838 scsi_exit_hosts();
839 scsi_exit_devinfo();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 scsi_exit_procfs();
841 scsi_exit_queue();
Dan Williamsa4683482012-07-09 19:33:30 -0700842 async_unregister_domain(&scsi_sd_probe_domain);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843}
844
845subsys_initcall(init_scsi);
846module_exit(exit_scsi);