1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * scsi.c Copyright (C) 1992 Drew Eckhardt 4 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale 5 * Copyright (C) 2002, 2003 Christoph Hellwig 6 * 7 * generic mid-level SCSI driver 8 * Initial versions: Drew Eckhardt 9 * Subsequent revisions: Eric Youngdale 10 * 11 * <drew@colorado.edu> 12 * 13 * Bug correction thanks go to : 14 * Rik Faith <faith@cs.unc.edu> 15 * Tommy Thorn <tthorn> 16 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de> 17 * 18 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to 19 * add scatter-gather, multiple outstanding request, and other 20 * enhancements. 21 * 22 * Native multichannel, wide scsi, /proc/scsi and hot plugging 23 * support added by Michael Neuffer <mike@i-connect.net> 24 * 25 * Added request_module("scsi_hostadapter") for kerneld: 26 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) 27 * Bjorn Ekwall <bj0rn@blox.se> 28 * (changed to kmod) 29 * 30 * Major improvements to the timeout, abort, and reset processing, 31 * as well as performance modifications for large queue depths by 32 * Leonard N. Zubkoff <lnz@dandelion.com> 33 * 34 * Converted cli() code to spinlocks, Ingo Molnar 35 * 36 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli 37 * 38 * out_of_space hacks, D. Gilbert (dpg) 990608 39 */ 40 41 #include <linux/module.h> 42 #include <linux/moduleparam.h> 43 #include <linux/kernel.h> 44 #include <linux/timer.h> 45 #include <linux/string.h> 46 #include <linux/slab.h> 47 #include <linux/blkdev.h> 48 #include <linux/delay.h> 49 #include <linux/init.h> 50 #include <linux/completion.h> 51 #include <linux/unistd.h> 52 #include <linux/spinlock.h> 53 #include <linux/kmod.h> 54 #include <linux/interrupt.h> 55 #include <linux/notifier.h> 56 #include <linux/cpu.h> 57 #include <linux/mutex.h> 58 #include <linux/unaligned.h> 59 60 #include <scsi/scsi.h> 61 #include <scsi/scsi_cmnd.h> 62 #include <scsi/scsi_dbg.h> 63 #include <scsi/scsi_device.h> 64 #include <scsi/scsi_driver.h> 65 #include <scsi/scsi_eh.h> 66 #include <scsi/scsi_host.h> 67 #include <scsi/scsi_tcq.h> 68 69 #include "scsi_priv.h" 70 #include "scsi_logging.h" 71 72 #define CREATE_TRACE_POINTS 73 #include <trace/events/scsi.h> 74 75 /* 76 * Definitions and constants. 77 */ 78 79 /* 80 * Note - the initial logging level can be set here to log events at boot time. 81 * After the system is up, you may enable logging via the /proc interface. 82 */ 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(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 */ 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(&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 */ 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(sdev->request_queue, depth); 228 229 sbitmap_resize(&sdev->budget_map, 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: 246 * * 0 - No change needed 247 * * >0 - Adjust queue depth to this new depth, 248 * * -1 - Drop back to untagged operation using host->cmd_per_lun as the 249 * untagged command depth 250 * 251 * Lock Status: None held on entry 252 * 253 * Notes: Low level drivers may call this at any time and we will do 254 * "The Right Thing." We are interrupt context safe. 255 */ 256 int scsi_track_queue_full(struct scsi_device *sdev, int depth) 257 { 258 259 /* 260 * Don't let QUEUE_FULLs on the same 261 * jiffies count, they could all be from 262 * same event. 263 */ 264 if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) 265 return 0; 266 267 sdev->last_queue_full_time = jiffies; 268 if (sdev->last_queue_full_depth != depth) { 269 sdev->last_queue_full_count = 1; 270 sdev->last_queue_full_depth = depth; 271 } else { 272 sdev->last_queue_full_count++; 273 } 274 275 if (sdev->last_queue_full_count <= 10) 276 return 0; 277 278 return scsi_change_queue_depth(sdev, depth); 279 } 280 EXPORT_SYMBOL(scsi_track_queue_full); 281 282 /** 283 * scsi_vpd_inquiry - Request a device provide us with a VPD page 284 * @sdev: The device to ask 285 * @buffer: Where to put the result 286 * @page: Which Vital Product Data to return 287 * @len: The length of the buffer 288 * 289 * This is an internal helper function. You probably want to use 290 * scsi_get_vpd_page instead. 291 * 292 * Returns size of the vpd page on success or a negative error number. 293 */ 294 static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, 295 u8 page, unsigned len) 296 { 297 int result; 298 unsigned char cmd[16]; 299 300 if (len < 4) 301 return -EINVAL; 302 303 cmd[0] = INQUIRY; 304 cmd[1] = 1; /* EVPD */ 305 cmd[2] = page; 306 cmd[3] = len >> 8; 307 cmd[4] = len & 0xff; 308 cmd[5] = 0; /* Control byte */ 309 310 /* 311 * I'm not convinced we need to try quite this hard to get VPD, but 312 * all the existing users tried this hard. 313 */ 314 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len, 315 30 * HZ, 3, NULL); 316 if (result) 317 return -EIO; 318 319 /* 320 * Sanity check that we got the page back that we asked for and that 321 * the page size is not 0. 322 */ 323 if (buffer[1] != page) 324 return -EIO; 325 326 result = get_unaligned_be16(&buffer[2]); 327 if (!result) 328 return -EIO; 329 330 return result + 4; 331 } 332 333 enum scsi_vpd_parameters { 334 SCSI_VPD_HEADER_SIZE = 4, 335 SCSI_VPD_LIST_SIZE = 36, 336 }; 337 338 static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page) 339 { 340 unsigned char vpd[SCSI_VPD_LIST_SIZE] __aligned(4); 341 int result; 342 343 if (sdev->no_vpd_size) 344 return SCSI_DEFAULT_VPD_LEN; 345 346 /* 347 * Fetch the supported pages VPD and validate that the requested page 348 * number is present. 349 */ 350 if (page != 0) { 351 result = scsi_vpd_inquiry(sdev, vpd, 0, sizeof(vpd)); 352 if (result < SCSI_VPD_HEADER_SIZE) 353 return 0; 354 355 if (result > sizeof(vpd)) { 356 dev_warn_once(&sdev->sdev_gendev, 357 "%s: long VPD page 0 length: %d bytes\n", 358 __func__, result); 359 result = sizeof(vpd); 360 } 361 362 result -= SCSI_VPD_HEADER_SIZE; 363 if (!memchr(&vpd[SCSI_VPD_HEADER_SIZE], page, result)) 364 return 0; 365 } 366 /* 367 * Fetch the VPD page header to find out how big the page 368 * is. This is done to prevent problems on legacy devices 369 * which can not handle allocation lengths as large as 370 * potentially requested by the caller. 371 */ 372 result = scsi_vpd_inquiry(sdev, vpd, page, SCSI_VPD_HEADER_SIZE); 373 if (result < 0) 374 return 0; 375 376 if (result < SCSI_VPD_HEADER_SIZE) { 377 dev_warn_once(&sdev->sdev_gendev, 378 "%s: short VPD page 0x%02x length: %d bytes\n", 379 __func__, page, result); 380 return 0; 381 } 382 383 return result; 384 } 385 386 /** 387 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device 388 * @sdev: The device to ask 389 * @page: Which Vital Product Data to return 390 * @buf: where to store the VPD 391 * @buf_len: number of bytes in the VPD buffer area 392 * 393 * SCSI devices may optionally supply Vital Product Data. Each 'page' 394 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). 395 * If the device supports this VPD page, this routine fills @buf 396 * with the data from that page and return 0. If the VPD page is not 397 * supported or its content cannot be retrieved, -EINVAL is returned. 398 */ 399 int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, 400 int buf_len) 401 { 402 int result, vpd_len; 403 404 if (!scsi_device_supports_vpd(sdev)) 405 return -EINVAL; 406 407 vpd_len = scsi_get_vpd_size(sdev, page); 408 if (vpd_len <= 0) 409 return -EINVAL; 410 411 vpd_len = min(vpd_len, buf_len); 412 413 /* 414 * Fetch the actual page. Since the appropriate size was reported 415 * by the device it is now safe to ask for something bigger. 416 */ 417 memset(buf, 0, buf_len); 418 result = scsi_vpd_inquiry(sdev, buf, page, vpd_len); 419 if (result < 0) 420 return -EINVAL; 421 else if (result > vpd_len) 422 dev_warn_once(&sdev->sdev_gendev, 423 "%s: VPD page 0x%02x result %d > %d bytes\n", 424 __func__, page, result, vpd_len); 425 426 return 0; 427 } 428 EXPORT_SYMBOL_GPL(scsi_get_vpd_page); 429 430 /** 431 * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device 432 * @sdev: The device to ask 433 * @page: Which Vital Product Data to return 434 * 435 * Returns %NULL upon failure. 436 */ 437 static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page) 438 { 439 struct scsi_vpd *vpd_buf; 440 int vpd_len, result; 441 442 vpd_len = scsi_get_vpd_size(sdev, page); 443 if (vpd_len <= 0) 444 return NULL; 445 446 retry_pg: 447 /* 448 * Fetch the actual page. Since the appropriate size was reported 449 * by the device it is now safe to ask for something bigger. 450 */ 451 vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL); 452 if (!vpd_buf) 453 return NULL; 454 455 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len); 456 if (result < 0) { 457 kfree(vpd_buf); 458 return NULL; 459 } 460 if (result > vpd_len) { 461 dev_warn_once(&sdev->sdev_gendev, 462 "%s: VPD page 0x%02x result %d > %d bytes\n", 463 __func__, page, result, vpd_len); 464 vpd_len = result; 465 kfree(vpd_buf); 466 goto retry_pg; 467 } 468 469 vpd_buf->len = result; 470 471 return vpd_buf; 472 } 473 474 static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page, 475 struct scsi_vpd __rcu **sdev_vpd_buf) 476 { 477 struct scsi_vpd *vpd_buf; 478 479 vpd_buf = scsi_get_vpd_buf(sdev, page); 480 if (!vpd_buf) 481 return; 482 483 mutex_lock(&sdev->inquiry_mutex); 484 vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf, 485 lockdep_is_held(&sdev->inquiry_mutex)); 486 mutex_unlock(&sdev->inquiry_mutex); 487 488 if (vpd_buf) 489 kfree_rcu(vpd_buf, rcu); 490 } 491 492 /** 493 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure 494 * @sdev: The device to ask 495 * 496 * Attach the 'Device Identification' VPD page (0x83) and the 497 * 'Unit Serial Number' VPD page (0x80) to a SCSI device 498 * structure. This information can be used to identify the device 499 * uniquely. 500 */ 501 void scsi_attach_vpd(struct scsi_device *sdev) 502 { 503 int i; 504 struct scsi_vpd *vpd_buf; 505 506 if (!scsi_device_supports_vpd(sdev)) 507 return; 508 509 /* Ask for all the pages supported by this device */ 510 vpd_buf = scsi_get_vpd_buf(sdev, 0); 511 if (!vpd_buf) 512 return; 513 514 for (i = 4; i < vpd_buf->len; i++) { 515 switch (vpd_buf->data[i]) { 516 case 0x0: 517 scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0); 518 break; 519 case 0x80: 520 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80); 521 break; 522 case 0x83: 523 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83); 524 break; 525 case 0x89: 526 scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89); 527 break; 528 case 0xb0: 529 scsi_update_vpd_page(sdev, 0xb0, &sdev->vpd_pgb0); 530 break; 531 case 0xb1: 532 scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1); 533 break; 534 case 0xb2: 535 scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2); 536 break; 537 case 0xb7: 538 scsi_update_vpd_page(sdev, 0xb7, &sdev->vpd_pgb7); 539 break; 540 default: 541 break; 542 } 543 } 544 kfree(vpd_buf); 545 } 546 547 /** 548 * scsi_report_opcode - Find out if a given command is supported 549 * @sdev: scsi device to query 550 * @buffer: scratch buffer (must be at least 20 bytes long) 551 * @len: length of buffer 552 * @opcode: opcode for the command to look up 553 * @sa: service action for the command to look up 554 * 555 * Uses the REPORT SUPPORTED OPERATION CODES to check support for the 556 * command identified with @opcode and @sa. If the command does not 557 * have a service action, @sa must be 0. Returns -EINVAL if RSOC fails, 558 * 0 if the command is not supported and 1 if the device claims to 559 * support the command. 560 */ 561 int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, 562 unsigned int len, unsigned char opcode, 563 unsigned short sa) 564 { 565 unsigned char cmd[16]; 566 struct scsi_sense_hdr sshdr; 567 int result, request_len; 568 const struct scsi_exec_args exec_args = { 569 .sshdr = &sshdr, 570 }; 571 572 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) 573 return -EINVAL; 574 575 /* RSOC header + size of command we are asking about */ 576 request_len = 4 + COMMAND_SIZE(opcode); 577 if (request_len > len) { 578 dev_warn_once(&sdev->sdev_gendev, 579 "%s: len %u bytes, opcode 0x%02x needs %u\n", 580 __func__, len, opcode, request_len); 581 return -EINVAL; 582 } 583 584 memset(cmd, 0, 16); 585 cmd[0] = MAINTENANCE_IN; 586 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; 587 if (!sa) { 588 cmd[2] = 1; /* One command format */ 589 cmd[3] = opcode; 590 } else { 591 cmd[2] = 3; /* One command format with service action */ 592 cmd[3] = opcode; 593 put_unaligned_be16(sa, &cmd[4]); 594 } 595 put_unaligned_be32(request_len, &cmd[6]); 596 memset(buffer, 0, len); 597 598 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, 599 request_len, 30 * HZ, 3, &exec_args); 600 if (result < 0) 601 return result; 602 if (result && scsi_sense_valid(&sshdr) && 603 sshdr.sense_key == ILLEGAL_REQUEST && 604 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) 605 return -EINVAL; 606 607 if ((buffer[1] & 3) == 3) /* Command supported */ 608 return 1; 609 610 return 0; 611 } 612 EXPORT_SYMBOL(scsi_report_opcode); 613 614 #define SCSI_CDL_CHECK_BUF_LEN 64 615 616 static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa, 617 unsigned char *buf) 618 { 619 int ret; 620 u8 cdlp; 621 622 /* Check operation code */ 623 ret = scsi_report_opcode(sdev, buf, SCSI_CDL_CHECK_BUF_LEN, opcode, sa); 624 if (ret <= 0) 625 return false; 626 627 if ((buf[1] & 0x03) != 0x03) 628 return false; 629 630 /* 631 * See SPC-6, One_command parameter data format for 632 * REPORT SUPPORTED OPERATION CODES. We have the following cases 633 * depending on rwcdlp (buf[0] & 0x01) value: 634 * - rwcdlp == 0: then cdlp indicates support for the A mode page when 635 * it is equal to 1 and for the B mode page when it is 636 * equal to 2. 637 * - rwcdlp == 1: then cdlp indicates support for the T2A mode page 638 * when it is equal to 1 and for the T2B mode page when 639 * it is equal to 2. 640 * Overall, to detect support for command duration limits, we only need 641 * to check that cdlp is 1 or 2. 642 */ 643 cdlp = (buf[1] & 0x18) >> 3; 644 645 return cdlp == 0x01 || cdlp == 0x02; 646 } 647 648 /** 649 * scsi_cdl_check - Check if a SCSI device supports Command Duration Limits 650 * @sdev: The device to check 651 */ 652 void scsi_cdl_check(struct scsi_device *sdev) 653 { 654 bool cdl_supported; 655 unsigned char *buf; 656 657 /* 658 * Support for CDL was defined in SPC-5. Ignore devices reporting an 659 * lower SPC version. This also avoids problems with old drives choking 660 * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a 661 * service action specified, as done in scsi_cdl_check_cmd(). 662 */ 663 if (sdev->scsi_level < SCSI_SPC_5) { 664 sdev->cdl_supported = 0; 665 return; 666 } 667 668 buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL); 669 if (!buf) { 670 sdev->cdl_supported = 0; 671 return; 672 } 673 674 /* Check support for READ_16, WRITE_16, READ_32 and WRITE_32 commands */ 675 cdl_supported = 676 scsi_cdl_check_cmd(sdev, READ_16, 0, buf) || 677 scsi_cdl_check_cmd(sdev, WRITE_16, 0, buf) || 678 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, READ_32, buf) || 679 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, WRITE_32, buf); 680 if (cdl_supported) { 681 /* 682 * We have CDL support: force the use of READ16/WRITE16. 683 * READ32 and WRITE32 will be used for devices that support 684 * the T10_PI_TYPE2_PROTECTION protection type. 685 */ 686 sdev->use_16_for_rw = 1; 687 sdev->use_10_for_rw = 0; 688 689 sdev->cdl_supported = 1; 690 691 /* 692 * If the device supports CDL, make sure that the current drive 693 * feature status is consistent with the user controlled 694 * cdl_enable state. 695 */ 696 scsi_cdl_enable(sdev, sdev->cdl_enable); 697 } else { 698 sdev->cdl_supported = 0; 699 } 700 701 kfree(buf); 702 } 703 704 /** 705 * scsi_cdl_enable - Enable or disable a SCSI device supports for Command 706 * Duration Limits 707 * @sdev: The target device 708 * @enable: the target state 709 */ 710 int scsi_cdl_enable(struct scsi_device *sdev, bool enable) 711 { 712 char buf[64]; 713 int ret; 714 715 if (!sdev->cdl_supported) 716 return -EOPNOTSUPP; 717 718 /* 719 * For ATA devices, CDL needs to be enabled with a SET FEATURES command. 720 */ 721 if (sdev->is_ata) { 722 struct scsi_mode_data data; 723 struct scsi_sense_hdr sshdr; 724 char *buf_data; 725 int len; 726 727 ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf), 728 5 * HZ, 3, &data, NULL); 729 if (ret) 730 return -EINVAL; 731 732 /* Enable or disable CDL using the ATA feature page */ 733 len = min_t(size_t, sizeof(buf), 734 data.length - data.header_length - 735 data.block_descriptor_length); 736 buf_data = buf + data.header_length + 737 data.block_descriptor_length; 738 739 /* 740 * If we want to enable CDL and CDL is already enabled on the 741 * device, do nothing. This avoids needlessly resetting the CDL 742 * statistics on the device as that is implied by the CDL enable 743 * action. Similar to this, there is no need to do anything if 744 * we want to disable CDL and CDL is already disabled. 745 */ 746 if (enable) { 747 if ((buf_data[4] & 0x03) == 0x02) 748 goto out; 749 buf_data[4] &= ~0x03; 750 buf_data[4] |= 0x02; 751 } else { 752 if ((buf_data[4] & 0x03) == 0x00) 753 goto out; 754 buf_data[4] &= ~0x03; 755 } 756 757 ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3, 758 &data, &sshdr); 759 if (ret) { 760 if (ret > 0 && scsi_sense_valid(&sshdr)) 761 scsi_print_sense_hdr(sdev, 762 dev_name(&sdev->sdev_gendev), &sshdr); 763 return ret; 764 } 765 } 766 767 out: 768 sdev->cdl_enable = enable; 769 770 return 0; 771 } 772 773 /** 774 * scsi_device_get - get an additional reference to a scsi_device 775 * @sdev: device to get a reference to 776 * 777 * Description: Gets a reference to the scsi_device and increments the use count 778 * of the underlying LLDD module. You must hold host_lock of the 779 * parent Scsi_Host or already have a reference when calling this. 780 * 781 * This will fail if a device is deleted or cancelled, or when the LLD module 782 * is in the process of being unloaded. 783 */ 784 int scsi_device_get(struct scsi_device *sdev) 785 { 786 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) 787 goto fail; 788 if (!try_module_get(sdev->host->hostt->module)) 789 goto fail; 790 if (!get_device(&sdev->sdev_gendev)) 791 goto fail_put_module; 792 return 0; 793 794 fail_put_module: 795 module_put(sdev->host->hostt->module); 796 fail: 797 return -ENXIO; 798 } 799 EXPORT_SYMBOL(scsi_device_get); 800 801 /** 802 * scsi_device_put - release a reference to a scsi_device 803 * @sdev: device to release a reference on. 804 * 805 * Description: Release a reference to the scsi_device and decrements the use 806 * count of the underlying LLDD module. The device is freed once the last 807 * user vanishes. 808 */ 809 void scsi_device_put(struct scsi_device *sdev) 810 { 811 struct module *mod = sdev->host->hostt->module; 812 813 put_device(&sdev->sdev_gendev); 814 module_put(mod); 815 } 816 EXPORT_SYMBOL(scsi_device_put); 817 818 /* helper for shost_for_each_device, see that for documentation */ 819 struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, 820 struct scsi_device *prev) 821 { 822 struct list_head *list = (prev ? &prev->siblings : &shost->__devices); 823 struct scsi_device *next = NULL; 824 unsigned long flags; 825 826 spin_lock_irqsave(shost->host_lock, flags); 827 while (list->next != &shost->__devices) { 828 next = list_entry(list->next, struct scsi_device, siblings); 829 /* skip devices that we can't get a reference to */ 830 if (!scsi_device_get(next)) 831 break; 832 next = NULL; 833 list = list->next; 834 } 835 spin_unlock_irqrestore(shost->host_lock, flags); 836 837 if (prev) 838 scsi_device_put(prev); 839 return next; 840 } 841 EXPORT_SYMBOL(__scsi_iterate_devices); 842 843 /** 844 * starget_for_each_device - helper to walk all devices of a target 845 * @starget: target whose devices we want to iterate over. 846 * @data: Opaque passed to each function call. 847 * @fn: Function to call on each device 848 * 849 * This traverses over each device of @starget. The devices have 850 * a reference that must be released by scsi_host_put when breaking 851 * out of the loop. 852 */ 853 void starget_for_each_device(struct scsi_target *starget, void *data, 854 void (*fn)(struct scsi_device *, void *)) 855 { 856 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 857 struct scsi_device *sdev; 858 859 shost_for_each_device(sdev, shost) { 860 if ((sdev->channel == starget->channel) && 861 (sdev->id == starget->id)) 862 fn(sdev, data); 863 } 864 } 865 EXPORT_SYMBOL(starget_for_each_device); 866 867 /** 868 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) 869 * @starget: target whose devices we want to iterate over. 870 * @data: parameter for callback @fn() 871 * @fn: callback function that is invoked for each device 872 * 873 * This traverses over each device of @starget. It does _not_ 874 * take a reference on the scsi_device, so the whole loop must be 875 * protected by shost->host_lock. 876 * 877 * Note: The only reason why drivers would want to use this is because 878 * they need to access the device list in irq context. Otherwise you 879 * really want to use starget_for_each_device instead. 880 **/ 881 void __starget_for_each_device(struct scsi_target *starget, void *data, 882 void (*fn)(struct scsi_device *, void *)) 883 { 884 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 885 struct scsi_device *sdev; 886 887 __shost_for_each_device(sdev, shost) { 888 if ((sdev->channel == starget->channel) && 889 (sdev->id == starget->id)) 890 fn(sdev, data); 891 } 892 } 893 EXPORT_SYMBOL(__starget_for_each_device); 894 895 /** 896 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) 897 * @starget: SCSI target pointer 898 * @lun: SCSI Logical Unit Number 899 * 900 * Description: Looks up the scsi_device with the specified @lun for a given 901 * @starget. The returned scsi_device does not have an additional 902 * reference. You must hold the host's host_lock over this call and 903 * any access to the returned scsi_device. A scsi_device in state 904 * SDEV_DEL is skipped. 905 * 906 * Note: The only reason why drivers should use this is because 907 * they need to access the device list in irq context. Otherwise you 908 * really want to use scsi_device_lookup_by_target instead. 909 **/ 910 struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, 911 u64 lun) 912 { 913 struct scsi_device *sdev; 914 915 list_for_each_entry(sdev, &starget->devices, same_target_siblings) { 916 if (sdev->sdev_state == SDEV_DEL) 917 continue; 918 if (sdev->lun ==lun) 919 return sdev; 920 } 921 922 return NULL; 923 } 924 EXPORT_SYMBOL(__scsi_device_lookup_by_target); 925 926 /** 927 * scsi_device_lookup_by_target - find a device given the target 928 * @starget: SCSI target pointer 929 * @lun: SCSI Logical Unit Number 930 * 931 * Description: Looks up the scsi_device with the specified @lun for a given 932 * @starget. The returned scsi_device has an additional reference that 933 * needs to be released with scsi_device_put once you're done with it. 934 **/ 935 struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, 936 u64 lun) 937 { 938 struct scsi_device *sdev; 939 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 940 unsigned long flags; 941 942 spin_lock_irqsave(shost->host_lock, flags); 943 sdev = __scsi_device_lookup_by_target(starget, lun); 944 if (sdev && scsi_device_get(sdev)) 945 sdev = NULL; 946 spin_unlock_irqrestore(shost->host_lock, flags); 947 948 return sdev; 949 } 950 EXPORT_SYMBOL(scsi_device_lookup_by_target); 951 952 /** 953 * __scsi_device_lookup - find a device given the host (UNLOCKED) 954 * @shost: SCSI host pointer 955 * @channel: SCSI channel (zero if only one channel) 956 * @id: SCSI target number (physical unit number) 957 * @lun: SCSI Logical Unit Number 958 * 959 * Description: Looks up the scsi_device with the specified @channel, @id, @lun 960 * for a given host. The returned scsi_device does not have an additional 961 * reference. You must hold the host's host_lock over this call and any access 962 * to the returned scsi_device. 963 * 964 * Note: The only reason why drivers would want to use this is because 965 * they need to access the device list in irq context. Otherwise you 966 * really want to use scsi_device_lookup instead. 967 **/ 968 struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, 969 uint channel, uint id, u64 lun) 970 { 971 struct scsi_device *sdev; 972 973 list_for_each_entry(sdev, &shost->__devices, siblings) { 974 if (sdev->sdev_state == SDEV_DEL) 975 continue; 976 if (sdev->channel == channel && sdev->id == id && 977 sdev->lun ==lun) 978 return sdev; 979 } 980 981 return NULL; 982 } 983 EXPORT_SYMBOL(__scsi_device_lookup); 984 985 /** 986 * scsi_device_lookup - find a device given the host 987 * @shost: SCSI host pointer 988 * @channel: SCSI channel (zero if only one channel) 989 * @id: SCSI target number (physical unit number) 990 * @lun: SCSI Logical Unit Number 991 * 992 * Description: Looks up the scsi_device with the specified @channel, @id, @lun 993 * for a given host. The returned scsi_device has an additional reference that 994 * needs to be released with scsi_device_put once you're done with it. 995 **/ 996 struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, 997 uint channel, uint id, u64 lun) 998 { 999 struct scsi_device *sdev; 1000 unsigned long flags; 1001 1002 spin_lock_irqsave(shost->host_lock, flags); 1003 sdev = __scsi_device_lookup(shost, channel, id, lun); 1004 if (sdev && scsi_device_get(sdev)) 1005 sdev = NULL; 1006 spin_unlock_irqrestore(shost->host_lock, flags); 1007 1008 return sdev; 1009 } 1010 EXPORT_SYMBOL(scsi_device_lookup); 1011 1012 MODULE_DESCRIPTION("SCSI core"); 1013 MODULE_LICENSE("GPL"); 1014 1015 module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); 1016 MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); 1017 1018 static int __init init_scsi(void) 1019 { 1020 int error; 1021 1022 error = scsi_init_procfs(); 1023 if (error) 1024 goto cleanup_queue; 1025 error = scsi_init_devinfo(); 1026 if (error) 1027 goto cleanup_procfs; 1028 error = scsi_init_hosts(); 1029 if (error) 1030 goto cleanup_devlist; 1031 error = scsi_init_sysctl(); 1032 if (error) 1033 goto cleanup_hosts; 1034 error = scsi_sysfs_register(); 1035 if (error) 1036 goto cleanup_sysctl; 1037 1038 scsi_netlink_init(); 1039 1040 printk(KERN_NOTICE "SCSI subsystem initialized\n"); 1041 return 0; 1042 1043 cleanup_sysctl: 1044 scsi_exit_sysctl(); 1045 cleanup_hosts: 1046 scsi_exit_hosts(); 1047 cleanup_devlist: 1048 scsi_exit_devinfo(); 1049 cleanup_procfs: 1050 scsi_exit_procfs(); 1051 cleanup_queue: 1052 scsi_exit_queue(); 1053 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", 1054 -error); 1055 return error; 1056 } 1057 1058 static void __exit exit_scsi(void) 1059 { 1060 scsi_netlink_exit(); 1061 scsi_sysfs_unregister(); 1062 scsi_exit_sysctl(); 1063 scsi_exit_hosts(); 1064 scsi_exit_devinfo(); 1065 scsi_exit_procfs(); 1066 scsi_exit_queue(); 1067 } 1068 1069 subsys_initcall(init_scsi); 1070 module_exit(exit_scsi); 1071