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 | */ |
83 | unsigned int scsi_logging_level; |
84 | #if defined(CONFIG_SCSI_LOGGING) |
85 | EXPORT_SYMBOL(scsi_logging_level); |
86 | #endif |
87 | |
88 | #ifdef CONFIG_SCSI_LOGGING |
89 | void 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 | |
115 | void 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(status: 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(shost: 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 | */ |
158 | void 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(v: &shost->host_blocked)) |
173 | atomic_set(v: &shost->host_blocked, i: 0); |
174 | if (atomic_read(v: &starget->target_blocked)) |
175 | atomic_set(v: &starget->target_blocked, i: 0); |
176 | if (atomic_read(v: &sdev->device_blocked)) |
177 | atomic_set(v: &sdev->device_blocked, i: 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(rq: scsi_cmd_to_rq(scmd: 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 | */ |
205 | int 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 | */ |
217 | int 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(q: sdev->request_queue, depth); |
228 | |
229 | sbitmap_resize(sb: &sdev->budget_map, depth: sdev->queue_depth); |
230 | |
231 | return sdev->queue_depth; |
232 | } |
233 | EXPORT_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 | */ |
254 | int 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 | } |
278 | EXPORT_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 | */ |
292 | static 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, opf: REQ_OP_DRV_IN, buffer, bufflen: len, |
313 | timeout: 30 * HZ, retries: 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(p: &buffer[2]); |
325 | if (!result) |
326 | return -EIO; |
327 | |
328 | return result + 4; |
329 | } |
330 | |
331 | static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page) |
332 | { |
333 | unsigned char [SCSI_VPD_HEADER_SIZE] __aligned(4); |
334 | int result; |
335 | |
336 | if (sdev->no_vpd_size) |
337 | return SCSI_DEFAULT_VPD_LEN; |
338 | |
339 | /* |
340 | * Fetch the VPD page header to find out how big the page |
341 | * is. This is done to prevent problems on legacy devices |
342 | * which can not handle allocation lengths as large as |
343 | * potentially requested by the caller. |
344 | */ |
345 | result = scsi_vpd_inquiry(sdev, buffer: vpd_header, page, len: sizeof(vpd_header)); |
346 | if (result < 0) |
347 | return 0; |
348 | |
349 | if (result < SCSI_VPD_HEADER_SIZE) { |
350 | dev_warn_once(&sdev->sdev_gendev, |
351 | "%s: short VPD page 0x%02x length: %d bytes\n" , |
352 | __func__, page, result); |
353 | return 0; |
354 | } |
355 | |
356 | return result; |
357 | } |
358 | |
359 | /** |
360 | * scsi_get_vpd_page - Get Vital Product Data from a SCSI device |
361 | * @sdev: The device to ask |
362 | * @page: Which Vital Product Data to return |
363 | * @buf: where to store the VPD |
364 | * @buf_len: number of bytes in the VPD buffer area |
365 | * |
366 | * SCSI devices may optionally supply Vital Product Data. Each 'page' |
367 | * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). |
368 | * If the device supports this VPD page, this routine fills @buf |
369 | * with the data from that page and return 0. If the VPD page is not |
370 | * supported or its content cannot be retrieved, -EINVAL is returned. |
371 | */ |
372 | int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, |
373 | int buf_len) |
374 | { |
375 | int result, vpd_len; |
376 | |
377 | if (!scsi_device_supports_vpd(sdev)) |
378 | return -EINVAL; |
379 | |
380 | vpd_len = scsi_get_vpd_size(sdev, page); |
381 | if (vpd_len <= 0) |
382 | return -EINVAL; |
383 | |
384 | vpd_len = min(vpd_len, buf_len); |
385 | |
386 | /* |
387 | * Fetch the actual page. Since the appropriate size was reported |
388 | * by the device it is now safe to ask for something bigger. |
389 | */ |
390 | memset(buf, 0, buf_len); |
391 | result = scsi_vpd_inquiry(sdev, buffer: buf, page, len: vpd_len); |
392 | if (result < 0) |
393 | return -EINVAL; |
394 | else if (result > vpd_len) |
395 | dev_warn_once(&sdev->sdev_gendev, |
396 | "%s: VPD page 0x%02x result %d > %d bytes\n" , |
397 | __func__, page, result, vpd_len); |
398 | |
399 | return 0; |
400 | } |
401 | EXPORT_SYMBOL_GPL(scsi_get_vpd_page); |
402 | |
403 | /** |
404 | * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device |
405 | * @sdev: The device to ask |
406 | * @page: Which Vital Product Data to return |
407 | * |
408 | * Returns %NULL upon failure. |
409 | */ |
410 | static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page) |
411 | { |
412 | struct scsi_vpd *vpd_buf; |
413 | int vpd_len, result; |
414 | |
415 | vpd_len = scsi_get_vpd_size(sdev, page); |
416 | if (vpd_len <= 0) |
417 | return NULL; |
418 | |
419 | retry_pg: |
420 | /* |
421 | * Fetch the actual page. Since the appropriate size was reported |
422 | * by the device it is now safe to ask for something bigger. |
423 | */ |
424 | vpd_buf = kmalloc(size: sizeof(*vpd_buf) + vpd_len, GFP_KERNEL); |
425 | if (!vpd_buf) |
426 | return NULL; |
427 | |
428 | result = scsi_vpd_inquiry(sdev, buffer: vpd_buf->data, page, len: vpd_len); |
429 | if (result < 0) { |
430 | kfree(objp: vpd_buf); |
431 | return NULL; |
432 | } |
433 | if (result > vpd_len) { |
434 | dev_warn_once(&sdev->sdev_gendev, |
435 | "%s: VPD page 0x%02x result %d > %d bytes\n" , |
436 | __func__, page, result, vpd_len); |
437 | vpd_len = result; |
438 | kfree(objp: vpd_buf); |
439 | goto retry_pg; |
440 | } |
441 | |
442 | vpd_buf->len = result; |
443 | |
444 | return vpd_buf; |
445 | } |
446 | |
447 | static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page, |
448 | struct scsi_vpd __rcu **sdev_vpd_buf) |
449 | { |
450 | struct scsi_vpd *vpd_buf; |
451 | |
452 | vpd_buf = scsi_get_vpd_buf(sdev, page); |
453 | if (!vpd_buf) |
454 | return; |
455 | |
456 | mutex_lock(&sdev->inquiry_mutex); |
457 | vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf, |
458 | lockdep_is_held(&sdev->inquiry_mutex)); |
459 | mutex_unlock(lock: &sdev->inquiry_mutex); |
460 | |
461 | if (vpd_buf) |
462 | kfree_rcu(vpd_buf, rcu); |
463 | } |
464 | |
465 | /** |
466 | * 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 | */ |
474 | void scsi_attach_vpd(struct scsi_device *sdev) |
475 | { |
476 | int i; |
477 | struct scsi_vpd *vpd_buf; |
478 | |
479 | if (!scsi_device_supports_vpd(sdev)) |
480 | return; |
481 | |
482 | /* Ask for all the pages supported by this device */ |
483 | vpd_buf = scsi_get_vpd_buf(sdev, page: 0); |
484 | if (!vpd_buf) |
485 | return; |
486 | |
487 | for (i = 4; i < vpd_buf->len; i++) { |
488 | if (vpd_buf->data[i] == 0x0) |
489 | scsi_update_vpd_page(sdev, page: 0x0, sdev_vpd_buf: &sdev->vpd_pg0); |
490 | if (vpd_buf->data[i] == 0x80) |
491 | scsi_update_vpd_page(sdev, page: 0x80, sdev_vpd_buf: &sdev->vpd_pg80); |
492 | if (vpd_buf->data[i] == 0x83) |
493 | scsi_update_vpd_page(sdev, page: 0x83, sdev_vpd_buf: &sdev->vpd_pg83); |
494 | if (vpd_buf->data[i] == 0x89) |
495 | scsi_update_vpd_page(sdev, page: 0x89, sdev_vpd_buf: &sdev->vpd_pg89); |
496 | if (vpd_buf->data[i] == 0xb0) |
497 | scsi_update_vpd_page(sdev, page: 0xb0, sdev_vpd_buf: &sdev->vpd_pgb0); |
498 | if (vpd_buf->data[i] == 0xb1) |
499 | scsi_update_vpd_page(sdev, page: 0xb1, sdev_vpd_buf: &sdev->vpd_pgb1); |
500 | if (vpd_buf->data[i] == 0xb2) |
501 | scsi_update_vpd_page(sdev, page: 0xb2, sdev_vpd_buf: &sdev->vpd_pgb2); |
502 | } |
503 | kfree(objp: vpd_buf); |
504 | } |
505 | |
506 | /** |
507 | * scsi_report_opcode - Find out if a given command is supported |
508 | * @sdev: scsi device to query |
509 | * @buffer: scratch buffer (must be at least 20 bytes long) |
510 | * @len: length of buffer |
511 | * @opcode: opcode for the command to look up |
512 | * @sa: service action for the command to look up |
513 | * |
514 | * Uses the REPORT SUPPORTED OPERATION CODES to check support for the |
515 | * command identified with @opcode and @sa. If the command does not |
516 | * have a service action, @sa must be 0. Returns -EINVAL if RSOC fails, |
517 | * 0 if the command is not supported and 1 if the device claims to |
518 | * support the command. |
519 | */ |
520 | int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, |
521 | unsigned int len, unsigned char opcode, |
522 | unsigned short sa) |
523 | { |
524 | unsigned char cmd[16]; |
525 | struct scsi_sense_hdr sshdr; |
526 | int result, request_len; |
527 | const struct scsi_exec_args exec_args = { |
528 | .sshdr = &sshdr, |
529 | }; |
530 | |
531 | if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) |
532 | return -EINVAL; |
533 | |
534 | /* RSOC header + size of command we are asking about */ |
535 | request_len = 4 + COMMAND_SIZE(opcode); |
536 | if (request_len > len) { |
537 | dev_warn_once(&sdev->sdev_gendev, |
538 | "%s: len %u bytes, opcode 0x%02x needs %u\n" , |
539 | __func__, len, opcode, request_len); |
540 | return -EINVAL; |
541 | } |
542 | |
543 | memset(cmd, 0, 16); |
544 | cmd[0] = MAINTENANCE_IN; |
545 | cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; |
546 | if (!sa) { |
547 | cmd[2] = 1; /* One command format */ |
548 | cmd[3] = opcode; |
549 | } else { |
550 | cmd[2] = 3; /* One command format with service action */ |
551 | cmd[3] = opcode; |
552 | put_unaligned_be16(val: sa, p: &cmd[4]); |
553 | } |
554 | put_unaligned_be32(val: request_len, p: &cmd[6]); |
555 | memset(buffer, 0, len); |
556 | |
557 | result = scsi_execute_cmd(sdev, cmd, opf: REQ_OP_DRV_IN, buffer, |
558 | bufflen: request_len, timeout: 30 * HZ, retries: 3, args: &exec_args); |
559 | if (result < 0) |
560 | return result; |
561 | if (result && scsi_sense_valid(sshdr: &sshdr) && |
562 | sshdr.sense_key == ILLEGAL_REQUEST && |
563 | (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) |
564 | return -EINVAL; |
565 | |
566 | if ((buffer[1] & 3) == 3) /* Command supported */ |
567 | return 1; |
568 | |
569 | return 0; |
570 | } |
571 | EXPORT_SYMBOL(scsi_report_opcode); |
572 | |
573 | #define SCSI_CDL_CHECK_BUF_LEN 64 |
574 | |
575 | static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa, |
576 | unsigned char *buf) |
577 | { |
578 | int ret; |
579 | u8 cdlp; |
580 | |
581 | /* Check operation code */ |
582 | ret = scsi_report_opcode(sdev, buf, SCSI_CDL_CHECK_BUF_LEN, opcode, sa); |
583 | if (ret <= 0) |
584 | return false; |
585 | |
586 | if ((buf[1] & 0x03) != 0x03) |
587 | return false; |
588 | |
589 | /* |
590 | * See SPC-6, One_command parameter data format for |
591 | * REPORT SUPPORTED OPERATION CODES. We have the following cases |
592 | * depending on rwcdlp (buf[0] & 0x01) value: |
593 | * - rwcdlp == 0: then cdlp indicates support for the A mode page when |
594 | * it is equal to 1 and for the B mode page when it is |
595 | * equal to 2. |
596 | * - rwcdlp == 1: then cdlp indicates support for the T2A mode page |
597 | * when it is equal to 1 and for the T2B mode page when |
598 | * it is equal to 2. |
599 | * Overall, to detect support for command duration limits, we only need |
600 | * to check that cdlp is 1 or 2. |
601 | */ |
602 | cdlp = (buf[1] & 0x18) >> 3; |
603 | |
604 | return cdlp == 0x01 || cdlp == 0x02; |
605 | } |
606 | |
607 | /** |
608 | * scsi_cdl_check - Check if a SCSI device supports Command Duration Limits |
609 | * @sdev: The device to check |
610 | */ |
611 | void scsi_cdl_check(struct scsi_device *sdev) |
612 | { |
613 | bool cdl_supported; |
614 | unsigned char *buf; |
615 | |
616 | /* |
617 | * Support for CDL was defined in SPC-5. Ignore devices reporting an |
618 | * lower SPC version. This also avoids problems with old drives choking |
619 | * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a |
620 | * service action specified, as done in scsi_cdl_check_cmd(). |
621 | */ |
622 | if (sdev->scsi_level < SCSI_SPC_5) { |
623 | sdev->cdl_supported = 0; |
624 | return; |
625 | } |
626 | |
627 | buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL); |
628 | if (!buf) { |
629 | sdev->cdl_supported = 0; |
630 | return; |
631 | } |
632 | |
633 | /* Check support for READ_16, WRITE_16, READ_32 and WRITE_32 commands */ |
634 | cdl_supported = |
635 | scsi_cdl_check_cmd(sdev, READ_16, sa: 0, buf) || |
636 | scsi_cdl_check_cmd(sdev, WRITE_16, sa: 0, buf) || |
637 | scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, READ_32, buf) || |
638 | scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, WRITE_32, buf); |
639 | if (cdl_supported) { |
640 | /* |
641 | * We have CDL support: force the use of READ16/WRITE16. |
642 | * READ32 and WRITE32 will be used for devices that support |
643 | * the T10_PI_TYPE2_PROTECTION protection type. |
644 | */ |
645 | sdev->use_16_for_rw = 1; |
646 | sdev->use_10_for_rw = 0; |
647 | |
648 | sdev->cdl_supported = 1; |
649 | } else { |
650 | sdev->cdl_supported = 0; |
651 | } |
652 | |
653 | kfree(objp: buf); |
654 | } |
655 | |
656 | /** |
657 | * scsi_cdl_enable - Enable or disable a SCSI device supports for Command |
658 | * Duration Limits |
659 | * @sdev: The target device |
660 | * @enable: the target state |
661 | */ |
662 | int scsi_cdl_enable(struct scsi_device *sdev, bool enable) |
663 | { |
664 | struct scsi_mode_data data; |
665 | struct scsi_sense_hdr sshdr; |
666 | struct scsi_vpd *vpd; |
667 | bool is_ata = false; |
668 | char buf[64]; |
669 | int ret; |
670 | |
671 | if (!sdev->cdl_supported) |
672 | return -EOPNOTSUPP; |
673 | |
674 | rcu_read_lock(); |
675 | vpd = rcu_dereference(sdev->vpd_pg89); |
676 | if (vpd) |
677 | is_ata = true; |
678 | rcu_read_unlock(); |
679 | |
680 | /* |
681 | * For ATA devices, CDL needs to be enabled with a SET FEATURES command. |
682 | */ |
683 | if (is_ata) { |
684 | char *buf_data; |
685 | int len; |
686 | |
687 | ret = scsi_mode_sense(sdev, dbd: 0x08, modepage: 0x0a, subpage: 0xf2, buffer: buf, len: sizeof(buf), |
688 | timeout: 5 * HZ, retries: 3, data: &data, NULL); |
689 | if (ret) |
690 | return -EINVAL; |
691 | |
692 | /* Enable CDL using the ATA feature page */ |
693 | len = min_t(size_t, sizeof(buf), |
694 | data.length - data.header_length - |
695 | data.block_descriptor_length); |
696 | buf_data = buf + data.header_length + |
697 | data.block_descriptor_length; |
698 | if (enable) |
699 | buf_data[4] = 0x02; |
700 | else |
701 | buf_data[4] = 0; |
702 | |
703 | ret = scsi_mode_select(sdev, pf: 1, sp: 0, buffer: buf_data, len, timeout: 5 * HZ, retries: 3, |
704 | data: &data, &sshdr); |
705 | if (ret) { |
706 | if (ret > 0 && scsi_sense_valid(sshdr: &sshdr)) |
707 | scsi_print_sense_hdr(sdev, |
708 | dev_name(dev: &sdev->sdev_gendev), &sshdr); |
709 | return ret; |
710 | } |
711 | } |
712 | |
713 | sdev->cdl_enable = enable; |
714 | |
715 | return 0; |
716 | } |
717 | |
718 | /** |
719 | * scsi_device_get - get an additional reference to a scsi_device |
720 | * @sdev: device to get a reference to |
721 | * |
722 | * Description: Gets a reference to the scsi_device and increments the use count |
723 | * of the underlying LLDD module. You must hold host_lock of the |
724 | * parent Scsi_Host or already have a reference when calling this. |
725 | * |
726 | * This will fail if a device is deleted or cancelled, or when the LLD module |
727 | * is in the process of being unloaded. |
728 | */ |
729 | int scsi_device_get(struct scsi_device *sdev) |
730 | { |
731 | if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) |
732 | goto fail; |
733 | if (!try_module_get(module: sdev->host->hostt->module)) |
734 | goto fail; |
735 | if (!get_device(dev: &sdev->sdev_gendev)) |
736 | goto fail_put_module; |
737 | return 0; |
738 | |
739 | fail_put_module: |
740 | module_put(module: sdev->host->hostt->module); |
741 | fail: |
742 | return -ENXIO; |
743 | } |
744 | EXPORT_SYMBOL(scsi_device_get); |
745 | |
746 | /** |
747 | * scsi_device_put - release a reference to a scsi_device |
748 | * @sdev: device to release a reference on. |
749 | * |
750 | * Description: Release a reference to the scsi_device and decrements the use |
751 | * count of the underlying LLDD module. The device is freed once the last |
752 | * user vanishes. |
753 | */ |
754 | void scsi_device_put(struct scsi_device *sdev) |
755 | { |
756 | struct module *mod = sdev->host->hostt->module; |
757 | |
758 | put_device(dev: &sdev->sdev_gendev); |
759 | module_put(module: mod); |
760 | } |
761 | EXPORT_SYMBOL(scsi_device_put); |
762 | |
763 | /* helper for shost_for_each_device, see that for documentation */ |
764 | struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
765 | struct scsi_device *prev) |
766 | { |
767 | struct list_head *list = (prev ? &prev->siblings : &shost->__devices); |
768 | struct scsi_device *next = NULL; |
769 | unsigned long flags; |
770 | |
771 | spin_lock_irqsave(shost->host_lock, flags); |
772 | while (list->next != &shost->__devices) { |
773 | next = list_entry(list->next, struct scsi_device, siblings); |
774 | /* skip devices that we can't get a reference to */ |
775 | if (!scsi_device_get(next)) |
776 | break; |
777 | next = NULL; |
778 | list = list->next; |
779 | } |
780 | spin_unlock_irqrestore(lock: shost->host_lock, flags); |
781 | |
782 | if (prev) |
783 | scsi_device_put(prev); |
784 | return next; |
785 | } |
786 | EXPORT_SYMBOL(__scsi_iterate_devices); |
787 | |
788 | /** |
789 | * starget_for_each_device - helper to walk all devices of a target |
790 | * @starget: target whose devices we want to iterate over. |
791 | * @data: Opaque passed to each function call. |
792 | * @fn: Function to call on each device |
793 | * |
794 | * This traverses over each device of @starget. The devices have |
795 | * a reference that must be released by scsi_host_put when breaking |
796 | * out of the loop. |
797 | */ |
798 | void starget_for_each_device(struct scsi_target *starget, void *data, |
799 | void (*fn)(struct scsi_device *, void *)) |
800 | { |
801 | struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent); |
802 | struct scsi_device *sdev; |
803 | |
804 | shost_for_each_device(sdev, shost) { |
805 | if ((sdev->channel == starget->channel) && |
806 | (sdev->id == starget->id)) |
807 | fn(sdev, data); |
808 | } |
809 | } |
810 | EXPORT_SYMBOL(starget_for_each_device); |
811 | |
812 | /** |
813 | * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
814 | * @starget: target whose devices we want to iterate over. |
815 | * @data: parameter for callback @fn() |
816 | * @fn: callback function that is invoked for each device |
817 | * |
818 | * This traverses over each device of @starget. It does _not_ |
819 | * take a reference on the scsi_device, so the whole loop must be |
820 | * protected by shost->host_lock. |
821 | * |
822 | * Note: The only reason why drivers would want to use this is because |
823 | * they need to access the device list in irq context. Otherwise you |
824 | * really want to use starget_for_each_device instead. |
825 | **/ |
826 | void __starget_for_each_device(struct scsi_target *starget, void *data, |
827 | void (*fn)(struct scsi_device *, void *)) |
828 | { |
829 | struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent); |
830 | struct scsi_device *sdev; |
831 | |
832 | __shost_for_each_device(sdev, shost) { |
833 | if ((sdev->channel == starget->channel) && |
834 | (sdev->id == starget->id)) |
835 | fn(sdev, data); |
836 | } |
837 | } |
838 | EXPORT_SYMBOL(__starget_for_each_device); |
839 | |
840 | /** |
841 | * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) |
842 | * @starget: SCSI target pointer |
843 | * @lun: SCSI Logical Unit Number |
844 | * |
845 | * Description: Looks up the scsi_device with the specified @lun for a given |
846 | * @starget. The returned scsi_device does not have an additional |
847 | * reference. You must hold the host's host_lock over this call and |
848 | * any access to the returned scsi_device. A scsi_device in state |
849 | * SDEV_DEL is skipped. |
850 | * |
851 | * Note: The only reason why drivers should use this is because |
852 | * they need to access the device list in irq context. Otherwise you |
853 | * really want to use scsi_device_lookup_by_target instead. |
854 | **/ |
855 | struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, |
856 | u64 lun) |
857 | { |
858 | struct scsi_device *sdev; |
859 | |
860 | list_for_each_entry(sdev, &starget->devices, same_target_siblings) { |
861 | if (sdev->sdev_state == SDEV_DEL) |
862 | continue; |
863 | if (sdev->lun ==lun) |
864 | return sdev; |
865 | } |
866 | |
867 | return NULL; |
868 | } |
869 | EXPORT_SYMBOL(__scsi_device_lookup_by_target); |
870 | |
871 | /** |
872 | * scsi_device_lookup_by_target - find a device given the target |
873 | * @starget: SCSI target pointer |
874 | * @lun: SCSI Logical Unit Number |
875 | * |
876 | * Description: Looks up the scsi_device with the specified @lun for a given |
877 | * @starget. The returned scsi_device has an additional reference that |
878 | * needs to be released with scsi_device_put once you're done with it. |
879 | **/ |
880 | struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, |
881 | u64 lun) |
882 | { |
883 | struct scsi_device *sdev; |
884 | struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent); |
885 | unsigned long flags; |
886 | |
887 | spin_lock_irqsave(shost->host_lock, flags); |
888 | sdev = __scsi_device_lookup_by_target(starget, lun); |
889 | if (sdev && scsi_device_get(sdev)) |
890 | sdev = NULL; |
891 | spin_unlock_irqrestore(lock: shost->host_lock, flags); |
892 | |
893 | return sdev; |
894 | } |
895 | EXPORT_SYMBOL(scsi_device_lookup_by_target); |
896 | |
897 | /** |
898 | * __scsi_device_lookup - find a device given the host (UNLOCKED) |
899 | * @shost: SCSI host pointer |
900 | * @channel: SCSI channel (zero if only one channel) |
901 | * @id: SCSI target number (physical unit number) |
902 | * @lun: SCSI Logical Unit Number |
903 | * |
904 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
905 | * for a given host. The returned scsi_device does not have an additional |
906 | * reference. You must hold the host's host_lock over this call and any access |
907 | * to the returned scsi_device. |
908 | * |
909 | * Note: The only reason why drivers would want to use this is because |
910 | * they need to access the device list in irq context. Otherwise you |
911 | * really want to use scsi_device_lookup instead. |
912 | **/ |
913 | struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, |
914 | uint channel, uint id, u64 lun) |
915 | { |
916 | struct scsi_device *sdev; |
917 | |
918 | list_for_each_entry(sdev, &shost->__devices, siblings) { |
919 | if (sdev->sdev_state == SDEV_DEL) |
920 | continue; |
921 | if (sdev->channel == channel && sdev->id == id && |
922 | sdev->lun ==lun) |
923 | return sdev; |
924 | } |
925 | |
926 | return NULL; |
927 | } |
928 | EXPORT_SYMBOL(__scsi_device_lookup); |
929 | |
930 | /** |
931 | * scsi_device_lookup - find a device given the host |
932 | * @shost: SCSI host pointer |
933 | * @channel: SCSI channel (zero if only one channel) |
934 | * @id: SCSI target number (physical unit number) |
935 | * @lun: SCSI Logical Unit Number |
936 | * |
937 | * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
938 | * for a given host. The returned scsi_device has an additional reference that |
939 | * needs to be released with scsi_device_put once you're done with it. |
940 | **/ |
941 | struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, |
942 | uint channel, uint id, u64 lun) |
943 | { |
944 | struct scsi_device *sdev; |
945 | unsigned long flags; |
946 | |
947 | spin_lock_irqsave(shost->host_lock, flags); |
948 | sdev = __scsi_device_lookup(shost, channel, id, lun); |
949 | if (sdev && scsi_device_get(sdev)) |
950 | sdev = NULL; |
951 | spin_unlock_irqrestore(lock: shost->host_lock, flags); |
952 | |
953 | return sdev; |
954 | } |
955 | EXPORT_SYMBOL(scsi_device_lookup); |
956 | |
957 | MODULE_DESCRIPTION("SCSI core" ); |
958 | MODULE_LICENSE("GPL" ); |
959 | |
960 | module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); |
961 | MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels" ); |
962 | |
963 | static int __init init_scsi(void) |
964 | { |
965 | int error; |
966 | |
967 | error = scsi_init_procfs(); |
968 | if (error) |
969 | goto cleanup_queue; |
970 | error = scsi_init_devinfo(); |
971 | if (error) |
972 | goto cleanup_procfs; |
973 | error = scsi_init_hosts(); |
974 | if (error) |
975 | goto cleanup_devlist; |
976 | error = scsi_init_sysctl(); |
977 | if (error) |
978 | goto cleanup_hosts; |
979 | error = scsi_sysfs_register(); |
980 | if (error) |
981 | goto cleanup_sysctl; |
982 | |
983 | scsi_netlink_init(); |
984 | |
985 | printk(KERN_NOTICE "SCSI subsystem initialized\n" ); |
986 | return 0; |
987 | |
988 | cleanup_sysctl: |
989 | scsi_exit_sysctl(); |
990 | cleanup_hosts: |
991 | scsi_exit_hosts(); |
992 | cleanup_devlist: |
993 | scsi_exit_devinfo(); |
994 | cleanup_procfs: |
995 | scsi_exit_procfs(); |
996 | cleanup_queue: |
997 | scsi_exit_queue(); |
998 | printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n" , |
999 | -error); |
1000 | return error; |
1001 | } |
1002 | |
1003 | static void __exit exit_scsi(void) |
1004 | { |
1005 | scsi_netlink_exit(); |
1006 | scsi_sysfs_unregister(); |
1007 | scsi_exit_sysctl(); |
1008 | scsi_exit_hosts(); |
1009 | scsi_exit_devinfo(); |
1010 | scsi_exit_procfs(); |
1011 | scsi_exit_queue(); |
1012 | } |
1013 | |
1014 | subsys_initcall(init_scsi); |
1015 | module_exit(exit_scsi); |
1016 | |