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(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: 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, REQ_OP_DRV_IN, buffer, len, 313 30 * HZ, 3, NULL); 314 if (result) 315 return -EIO; 316 317 /* 318 * Sanity check that we got the page back that we asked for and that 319 * the page size is not 0. 320 */ 321 if (buffer[1] != page) 322 return -EIO; 323 324 result = get_unaligned_be16(&buffer[2]); 325 if (!result) 326 return -EIO; 327 328 return result + 4; 329 } 330 331 enum scsi_vpd_parameters { 332 SCSI_VPD_HEADER_SIZE = 4, 333 SCSI_VPD_LIST_SIZE = 36, 334 }; 335 336 static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page) 337 { 338 unsigned char vpd[SCSI_VPD_LIST_SIZE] __aligned(4); 339 int result; 340 341 if (sdev->no_vpd_size) 342 return SCSI_DEFAULT_VPD_LEN; 343 344 /* 345 * Fetch the supported pages VPD and validate that the requested page 346 * number is present. 347 */ 348 if (page != 0) { 349 result = scsi_vpd_inquiry(sdev, vpd, 0, sizeof(vpd)); 350 if (result < SCSI_VPD_HEADER_SIZE) 351 return 0; 352 353 if (result > sizeof(vpd)) { 354 dev_warn_once(&sdev->sdev_gendev, 355 "%s: long VPD page 0 length: %d bytes\n", 356 __func__, result); 357 result = sizeof(vpd); 358 } 359 360 result -= SCSI_VPD_HEADER_SIZE; 361 if (!memchr(&vpd[SCSI_VPD_HEADER_SIZE], page, result)) 362 return 0; 363 } 364 /* 365 * Fetch the VPD page header to find out how big the page 366 * is. This is done to prevent problems on legacy devices 367 * which can not handle allocation lengths as large as 368 * potentially requested by the caller. 369 */ 370 result = scsi_vpd_inquiry(sdev, vpd, page, SCSI_VPD_HEADER_SIZE); 371 if (result < 0) 372 return 0; 373 374 if (result < SCSI_VPD_HEADER_SIZE) { 375 dev_warn_once(&sdev->sdev_gendev, 376 "%s: short VPD page 0x%02x length: %d bytes\n", 377 __func__, page, result); 378 return 0; 379 } 380 381 return result; 382 } 383 384 /** 385 * scsi_get_vpd_page - Get Vital Product Data from a SCSI device 386 * @sdev: The device to ask 387 * @page: Which Vital Product Data to return 388 * @buf: where to store the VPD 389 * @buf_len: number of bytes in the VPD buffer area 390 * 391 * SCSI devices may optionally supply Vital Product Data. Each 'page' 392 * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). 393 * If the device supports this VPD page, this routine fills @buf 394 * with the data from that page and return 0. If the VPD page is not 395 * supported or its content cannot be retrieved, -EINVAL is returned. 396 */ 397 int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, 398 int buf_len) 399 { 400 int result, vpd_len; 401 402 if (!scsi_device_supports_vpd(sdev)) 403 return -EINVAL; 404 405 vpd_len = scsi_get_vpd_size(sdev, page); 406 if (vpd_len <= 0) 407 return -EINVAL; 408 409 vpd_len = min(vpd_len, buf_len); 410 411 /* 412 * Fetch the actual page. Since the appropriate size was reported 413 * by the device it is now safe to ask for something bigger. 414 */ 415 memset(buf, 0, buf_len); 416 result = scsi_vpd_inquiry(sdev, buf, page, vpd_len); 417 if (result < 0) 418 return -EINVAL; 419 else if (result > vpd_len) 420 dev_warn_once(&sdev->sdev_gendev, 421 "%s: VPD page 0x%02x result %d > %d bytes\n", 422 __func__, page, result, vpd_len); 423 424 return 0; 425 } 426 EXPORT_SYMBOL_GPL(scsi_get_vpd_page); 427 428 /** 429 * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device 430 * @sdev: The device to ask 431 * @page: Which Vital Product Data to return 432 * 433 * Returns %NULL upon failure. 434 */ 435 static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page) 436 { 437 struct scsi_vpd *vpd_buf; 438 int vpd_len, result; 439 440 vpd_len = scsi_get_vpd_size(sdev, page); 441 if (vpd_len <= 0) 442 return NULL; 443 444 retry_pg: 445 /* 446 * Fetch the actual page. Since the appropriate size was reported 447 * by the device it is now safe to ask for something bigger. 448 */ 449 vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL); 450 if (!vpd_buf) 451 return NULL; 452 453 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len); 454 if (result < 0) { 455 kfree(vpd_buf); 456 return NULL; 457 } 458 if (result > vpd_len) { 459 dev_warn_once(&sdev->sdev_gendev, 460 "%s: VPD page 0x%02x result %d > %d bytes\n", 461 __func__, page, result, vpd_len); 462 vpd_len = result; 463 kfree(vpd_buf); 464 goto retry_pg; 465 } 466 467 vpd_buf->len = result; 468 469 return vpd_buf; 470 } 471 472 static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page, 473 struct scsi_vpd __rcu **sdev_vpd_buf) 474 { 475 struct scsi_vpd *vpd_buf; 476 477 vpd_buf = scsi_get_vpd_buf(sdev, page); 478 if (!vpd_buf) 479 return; 480 481 mutex_lock(&sdev->inquiry_mutex); 482 vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf, 483 lockdep_is_held(&sdev->inquiry_mutex)); 484 mutex_unlock(&sdev->inquiry_mutex); 485 486 if (vpd_buf) 487 kfree_rcu(vpd_buf, rcu); 488 } 489 490 /** 491 * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure 492 * @sdev: The device to ask 493 * 494 * Attach the 'Device Identification' VPD page (0x83) and the 495 * 'Unit Serial Number' VPD page (0x80) to a SCSI device 496 * structure. This information can be used to identify the device 497 * uniquely. 498 */ 499 void scsi_attach_vpd(struct scsi_device *sdev) 500 { 501 int i; 502 struct scsi_vpd *vpd_buf; 503 504 if (!scsi_device_supports_vpd(sdev)) 505 return; 506 507 /* Ask for all the pages supported by this device */ 508 vpd_buf = scsi_get_vpd_buf(sdev, 0); 509 if (!vpd_buf) 510 return; 511 512 for (i = 4; i < vpd_buf->len; i++) { 513 if (vpd_buf->data[i] == 0x0) 514 scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0); 515 if (vpd_buf->data[i] == 0x80) 516 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80); 517 if (vpd_buf->data[i] == 0x83) 518 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83); 519 if (vpd_buf->data[i] == 0x89) 520 scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89); 521 if (vpd_buf->data[i] == 0xb0) 522 scsi_update_vpd_page(sdev, 0xb0, &sdev->vpd_pgb0); 523 if (vpd_buf->data[i] == 0xb1) 524 scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1); 525 if (vpd_buf->data[i] == 0xb2) 526 scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2); 527 } 528 kfree(vpd_buf); 529 } 530 531 /** 532 * scsi_report_opcode - Find out if a given command is supported 533 * @sdev: scsi device to query 534 * @buffer: scratch buffer (must be at least 20 bytes long) 535 * @len: length of buffer 536 * @opcode: opcode for the command to look up 537 * @sa: service action for the command to look up 538 * 539 * Uses the REPORT SUPPORTED OPERATION CODES to check support for the 540 * command identified with @opcode and @sa. If the command does not 541 * have a service action, @sa must be 0. Returns -EINVAL if RSOC fails, 542 * 0 if the command is not supported and 1 if the device claims to 543 * support the command. 544 */ 545 int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, 546 unsigned int len, unsigned char opcode, 547 unsigned short sa) 548 { 549 unsigned char cmd[16]; 550 struct scsi_sense_hdr sshdr; 551 int result, request_len; 552 const struct scsi_exec_args exec_args = { 553 .sshdr = &sshdr, 554 }; 555 556 if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) 557 return -EINVAL; 558 559 /* RSOC header + size of command we are asking about */ 560 request_len = 4 + COMMAND_SIZE(opcode); 561 if (request_len > len) { 562 dev_warn_once(&sdev->sdev_gendev, 563 "%s: len %u bytes, opcode 0x%02x needs %u\n", 564 __func__, len, opcode, request_len); 565 return -EINVAL; 566 } 567 568 memset(cmd, 0, 16); 569 cmd[0] = MAINTENANCE_IN; 570 cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; 571 if (!sa) { 572 cmd[2] = 1; /* One command format */ 573 cmd[3] = opcode; 574 } else { 575 cmd[2] = 3; /* One command format with service action */ 576 cmd[3] = opcode; 577 put_unaligned_be16(sa, &cmd[4]); 578 } 579 put_unaligned_be32(request_len, &cmd[6]); 580 memset(buffer, 0, len); 581 582 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, 583 request_len, 30 * HZ, 3, &exec_args); 584 if (result < 0) 585 return result; 586 if (result && scsi_sense_valid(&sshdr) && 587 sshdr.sense_key == ILLEGAL_REQUEST && 588 (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) 589 return -EINVAL; 590 591 if ((buffer[1] & 3) == 3) /* Command supported */ 592 return 1; 593 594 return 0; 595 } 596 EXPORT_SYMBOL(scsi_report_opcode); 597 598 #define SCSI_CDL_CHECK_BUF_LEN 64 599 600 static bool scsi_cdl_check_cmd(struct scsi_device *sdev, u8 opcode, u16 sa, 601 unsigned char *buf) 602 { 603 int ret; 604 u8 cdlp; 605 606 /* Check operation code */ 607 ret = scsi_report_opcode(sdev, buf, SCSI_CDL_CHECK_BUF_LEN, opcode, sa); 608 if (ret <= 0) 609 return false; 610 611 if ((buf[1] & 0x03) != 0x03) 612 return false; 613 614 /* 615 * See SPC-6, One_command parameter data format for 616 * REPORT SUPPORTED OPERATION CODES. We have the following cases 617 * depending on rwcdlp (buf[0] & 0x01) value: 618 * - rwcdlp == 0: then cdlp indicates support for the A mode page when 619 * it is equal to 1 and for the B mode page when it is 620 * equal to 2. 621 * - rwcdlp == 1: then cdlp indicates support for the T2A mode page 622 * when it is equal to 1 and for the T2B mode page when 623 * it is equal to 2. 624 * Overall, to detect support for command duration limits, we only need 625 * to check that cdlp is 1 or 2. 626 */ 627 cdlp = (buf[1] & 0x18) >> 3; 628 629 return cdlp == 0x01 || cdlp == 0x02; 630 } 631 632 /** 633 * scsi_cdl_check - Check if a SCSI device supports Command Duration Limits 634 * @sdev: The device to check 635 */ 636 void scsi_cdl_check(struct scsi_device *sdev) 637 { 638 bool cdl_supported; 639 unsigned char *buf; 640 641 /* 642 * Support for CDL was defined in SPC-5. Ignore devices reporting an 643 * lower SPC version. This also avoids problems with old drives choking 644 * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a 645 * service action specified, as done in scsi_cdl_check_cmd(). 646 */ 647 if (sdev->scsi_level < SCSI_SPC_5) { 648 sdev->cdl_supported = 0; 649 return; 650 } 651 652 buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL); 653 if (!buf) { 654 sdev->cdl_supported = 0; 655 return; 656 } 657 658 /* Check support for READ_16, WRITE_16, READ_32 and WRITE_32 commands */ 659 cdl_supported = 660 scsi_cdl_check_cmd(sdev, READ_16, 0, buf) || 661 scsi_cdl_check_cmd(sdev, WRITE_16, 0, buf) || 662 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, READ_32, buf) || 663 scsi_cdl_check_cmd(sdev, VARIABLE_LENGTH_CMD, WRITE_32, buf); 664 if (cdl_supported) { 665 /* 666 * We have CDL support: force the use of READ16/WRITE16. 667 * READ32 and WRITE32 will be used for devices that support 668 * the T10_PI_TYPE2_PROTECTION protection type. 669 */ 670 sdev->use_16_for_rw = 1; 671 sdev->use_10_for_rw = 0; 672 673 sdev->cdl_supported = 1; 674 675 /* 676 * If the device supports CDL, make sure that the current drive 677 * feature status is consistent with the user controlled 678 * cdl_enable state. 679 */ 680 scsi_cdl_enable(sdev, sdev->cdl_enable); 681 } else { 682 sdev->cdl_supported = 0; 683 } 684 685 kfree(buf); 686 } 687 688 /** 689 * scsi_cdl_enable - Enable or disable a SCSI device supports for Command 690 * Duration Limits 691 * @sdev: The target device 692 * @enable: the target state 693 */ 694 int scsi_cdl_enable(struct scsi_device *sdev, bool enable) 695 { 696 struct scsi_mode_data data; 697 struct scsi_sense_hdr sshdr; 698 struct scsi_vpd *vpd; 699 bool is_ata = false; 700 char buf[64]; 701 int ret; 702 703 if (!sdev->cdl_supported) 704 return -EOPNOTSUPP; 705 706 rcu_read_lock(); 707 vpd = rcu_dereference(sdev->vpd_pg89); 708 if (vpd) 709 is_ata = true; 710 rcu_read_unlock(); 711 712 /* 713 * For ATA devices, CDL needs to be enabled with a SET FEATURES command. 714 */ 715 if (is_ata) { 716 char *buf_data; 717 int len; 718 719 ret = scsi_mode_sense(sdev, 0x08, 0x0a, 0xf2, buf, sizeof(buf), 720 5 * HZ, 3, &data, NULL); 721 if (ret) 722 return -EINVAL; 723 724 /* Enable CDL using the ATA feature page */ 725 len = min_t(size_t, sizeof(buf), 726 data.length - data.header_length - 727 data.block_descriptor_length); 728 buf_data = buf + data.header_length + 729 data.block_descriptor_length; 730 if (enable) 731 buf_data[4] = 0x02; 732 else 733 buf_data[4] = 0; 734 735 ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3, 736 &data, &sshdr); 737 if (ret) { 738 if (scsi_sense_valid(&sshdr)) 739 scsi_print_sense_hdr(sdev, 740 dev_name(&sdev->sdev_gendev), &sshdr); 741 return ret; 742 } 743 } 744 745 sdev->cdl_enable = enable; 746 747 return 0; 748 } 749 750 /** 751 * scsi_device_get - get an additional reference to a scsi_device 752 * @sdev: device to get a reference to 753 * 754 * Description: Gets a reference to the scsi_device and increments the use count 755 * of the underlying LLDD module. You must hold host_lock of the 756 * parent Scsi_Host or already have a reference when calling this. 757 * 758 * This will fail if a device is deleted or cancelled, or when the LLD module 759 * is in the process of being unloaded. 760 */ 761 int scsi_device_get(struct scsi_device *sdev) 762 { 763 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) 764 goto fail; 765 if (!try_module_get(sdev->host->hostt->module)) 766 goto fail; 767 if (!get_device(&sdev->sdev_gendev)) 768 goto fail_put_module; 769 return 0; 770 771 fail_put_module: 772 module_put(sdev->host->hostt->module); 773 fail: 774 return -ENXIO; 775 } 776 EXPORT_SYMBOL(scsi_device_get); 777 778 /** 779 * scsi_device_put - release a reference to a scsi_device 780 * @sdev: device to release a reference on. 781 * 782 * Description: Release a reference to the scsi_device and decrements the use 783 * count of the underlying LLDD module. The device is freed once the last 784 * user vanishes. 785 */ 786 void scsi_device_put(struct scsi_device *sdev) 787 { 788 struct module *mod = sdev->host->hostt->module; 789 790 put_device(&sdev->sdev_gendev); 791 module_put(mod); 792 } 793 EXPORT_SYMBOL(scsi_device_put); 794 795 /* helper for shost_for_each_device, see that for documentation */ 796 struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, 797 struct scsi_device *prev) 798 { 799 struct list_head *list = (prev ? &prev->siblings : &shost->__devices); 800 struct scsi_device *next = NULL; 801 unsigned long flags; 802 803 spin_lock_irqsave(shost->host_lock, flags); 804 while (list->next != &shost->__devices) { 805 next = list_entry(list->next, struct scsi_device, siblings); 806 /* skip devices that we can't get a reference to */ 807 if (!scsi_device_get(next)) 808 break; 809 next = NULL; 810 list = list->next; 811 } 812 spin_unlock_irqrestore(shost->host_lock, flags); 813 814 if (prev) 815 scsi_device_put(prev); 816 return next; 817 } 818 EXPORT_SYMBOL(__scsi_iterate_devices); 819 820 /** 821 * starget_for_each_device - helper to walk all devices of a target 822 * @starget: target whose devices we want to iterate over. 823 * @data: Opaque passed to each function call. 824 * @fn: Function to call on each device 825 * 826 * This traverses over each device of @starget. The devices have 827 * a reference that must be released by scsi_host_put when breaking 828 * out of the loop. 829 */ 830 void starget_for_each_device(struct scsi_target *starget, void *data, 831 void (*fn)(struct scsi_device *, void *)) 832 { 833 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 834 struct scsi_device *sdev; 835 836 shost_for_each_device(sdev, shost) { 837 if ((sdev->channel == starget->channel) && 838 (sdev->id == starget->id)) 839 fn(sdev, data); 840 } 841 } 842 EXPORT_SYMBOL(starget_for_each_device); 843 844 /** 845 * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) 846 * @starget: target whose devices we want to iterate over. 847 * @data: parameter for callback @fn() 848 * @fn: callback function that is invoked for each device 849 * 850 * This traverses over each device of @starget. It does _not_ 851 * take a reference on the scsi_device, so the whole loop must be 852 * protected by shost->host_lock. 853 * 854 * Note: The only reason why drivers would want to use this is because 855 * they need to access the device list in irq context. Otherwise you 856 * really want to use starget_for_each_device instead. 857 **/ 858 void __starget_for_each_device(struct scsi_target *starget, void *data, 859 void (*fn)(struct scsi_device *, void *)) 860 { 861 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 862 struct scsi_device *sdev; 863 864 __shost_for_each_device(sdev, shost) { 865 if ((sdev->channel == starget->channel) && 866 (sdev->id == starget->id)) 867 fn(sdev, data); 868 } 869 } 870 EXPORT_SYMBOL(__starget_for_each_device); 871 872 /** 873 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) 874 * @starget: SCSI target pointer 875 * @lun: SCSI Logical Unit Number 876 * 877 * Description: Looks up the scsi_device with the specified @lun for a given 878 * @starget. The returned scsi_device does not have an additional 879 * reference. You must hold the host's host_lock over this call and 880 * any access to the returned scsi_device. A scsi_device in state 881 * SDEV_DEL is skipped. 882 * 883 * Note: The only reason why drivers should use this is because 884 * they need to access the device list in irq context. Otherwise you 885 * really want to use scsi_device_lookup_by_target instead. 886 **/ 887 struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, 888 u64 lun) 889 { 890 struct scsi_device *sdev; 891 892 list_for_each_entry(sdev, &starget->devices, same_target_siblings) { 893 if (sdev->sdev_state == SDEV_DEL) 894 continue; 895 if (sdev->lun ==lun) 896 return sdev; 897 } 898 899 return NULL; 900 } 901 EXPORT_SYMBOL(__scsi_device_lookup_by_target); 902 903 /** 904 * scsi_device_lookup_by_target - find a device given the target 905 * @starget: SCSI target pointer 906 * @lun: SCSI Logical Unit Number 907 * 908 * Description: Looks up the scsi_device with the specified @lun for a given 909 * @starget. The returned scsi_device has an additional reference that 910 * needs to be released with scsi_device_put once you're done with it. 911 **/ 912 struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, 913 u64 lun) 914 { 915 struct scsi_device *sdev; 916 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 917 unsigned long flags; 918 919 spin_lock_irqsave(shost->host_lock, flags); 920 sdev = __scsi_device_lookup_by_target(starget, lun); 921 if (sdev && scsi_device_get(sdev)) 922 sdev = NULL; 923 spin_unlock_irqrestore(shost->host_lock, flags); 924 925 return sdev; 926 } 927 EXPORT_SYMBOL(scsi_device_lookup_by_target); 928 929 /** 930 * __scsi_device_lookup - find a device given the host (UNLOCKED) 931 * @shost: SCSI host pointer 932 * @channel: SCSI channel (zero if only one channel) 933 * @id: SCSI target number (physical unit number) 934 * @lun: SCSI Logical Unit Number 935 * 936 * Description: Looks up the scsi_device with the specified @channel, @id, @lun 937 * for a given host. The returned scsi_device does not have an additional 938 * reference. You must hold the host's host_lock over this call and any access 939 * to the returned scsi_device. 940 * 941 * Note: The only reason why drivers would want to use this is because 942 * they need to access the device list in irq context. Otherwise you 943 * really want to use scsi_device_lookup instead. 944 **/ 945 struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, 946 uint channel, uint id, u64 lun) 947 { 948 struct scsi_device *sdev; 949 950 list_for_each_entry(sdev, &shost->__devices, siblings) { 951 if (sdev->sdev_state == SDEV_DEL) 952 continue; 953 if (sdev->channel == channel && sdev->id == id && 954 sdev->lun ==lun) 955 return sdev; 956 } 957 958 return NULL; 959 } 960 EXPORT_SYMBOL(__scsi_device_lookup); 961 962 /** 963 * scsi_device_lookup - find a device given the host 964 * @shost: SCSI host pointer 965 * @channel: SCSI channel (zero if only one channel) 966 * @id: SCSI target number (physical unit number) 967 * @lun: SCSI Logical Unit Number 968 * 969 * Description: Looks up the scsi_device with the specified @channel, @id, @lun 970 * for a given host. The returned scsi_device has an additional reference that 971 * needs to be released with scsi_device_put once you're done with it. 972 **/ 973 struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, 974 uint channel, uint id, u64 lun) 975 { 976 struct scsi_device *sdev; 977 unsigned long flags; 978 979 spin_lock_irqsave(shost->host_lock, flags); 980 sdev = __scsi_device_lookup(shost, channel, id, lun); 981 if (sdev && scsi_device_get(sdev)) 982 sdev = NULL; 983 spin_unlock_irqrestore(shost->host_lock, flags); 984 985 return sdev; 986 } 987 EXPORT_SYMBOL(scsi_device_lookup); 988 989 MODULE_DESCRIPTION("SCSI core"); 990 MODULE_LICENSE("GPL"); 991 992 module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); 993 MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); 994 995 static int __init init_scsi(void) 996 { 997 int error; 998 999 error = scsi_init_procfs(); 1000 if (error) 1001 goto cleanup_queue; 1002 error = scsi_init_devinfo(); 1003 if (error) 1004 goto cleanup_procfs; 1005 error = scsi_init_hosts(); 1006 if (error) 1007 goto cleanup_devlist; 1008 error = scsi_init_sysctl(); 1009 if (error) 1010 goto cleanup_hosts; 1011 error = scsi_sysfs_register(); 1012 if (error) 1013 goto cleanup_sysctl; 1014 1015 scsi_netlink_init(); 1016 1017 printk(KERN_NOTICE "SCSI subsystem initialized\n"); 1018 return 0; 1019 1020 cleanup_sysctl: 1021 scsi_exit_sysctl(); 1022 cleanup_hosts: 1023 scsi_exit_hosts(); 1024 cleanup_devlist: 1025 scsi_exit_devinfo(); 1026 cleanup_procfs: 1027 scsi_exit_procfs(); 1028 cleanup_queue: 1029 scsi_exit_queue(); 1030 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", 1031 -error); 1032 return error; 1033 } 1034 1035 static void __exit exit_scsi(void) 1036 { 1037 scsi_netlink_exit(); 1038 scsi_sysfs_unregister(); 1039 scsi_exit_sysctl(); 1040 scsi_exit_hosts(); 1041 scsi_exit_devinfo(); 1042 scsi_exit_procfs(); 1043 scsi_exit_queue(); 1044 } 1045 1046 subsys_initcall(init_scsi); 1047 module_exit(exit_scsi); 1048