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 static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page) 332 { 333 unsigned char vpd_header[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, vpd_header, page, 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, buf, page, 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(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL); 425 if (!vpd_buf) 426 return NULL; 427 428 result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len); 429 if (result < 0) { 430 kfree(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(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(&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, 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, 0x0, &sdev->vpd_pg0); 490 if (vpd_buf->data[i] == 0x80) 491 scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80); 492 if (vpd_buf->data[i] == 0x83) 493 scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83); 494 if (vpd_buf->data[i] == 0x89) 495 scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89); 496 if (vpd_buf->data[i] == 0xb0) 497 scsi_update_vpd_page(sdev, 0xb0, &sdev->vpd_pgb0); 498 if (vpd_buf->data[i] == 0xb1) 499 scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1); 500 if (vpd_buf->data[i] == 0xb2) 501 scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2); 502 } 503 kfree(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(sa, &cmd[4]); 553 } 554 put_unaligned_be32(request_len, &cmd[6]); 555 memset(buffer, 0, len); 556 557 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, 558 request_len, 30 * HZ, 3, &exec_args); 559 if (result < 0) 560 return result; 561 if (result && scsi_sense_valid(&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, 0, buf) || 636 scsi_cdl_check_cmd(sdev, WRITE_16, 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(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, 0x08, 0x0a, 0xf2, buf, sizeof(buf), 688 5 * HZ, 3, &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, 1, 0, buf_data, len, 5 * HZ, 3, 704 &data, &sshdr); 705 if (ret) { 706 if (scsi_sense_valid(&sshdr)) 707 scsi_print_sense_hdr(sdev, 708 dev_name(&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(sdev->host->hostt->module)) 734 goto fail; 735 if (!get_device(&sdev->sdev_gendev)) 736 goto fail_put_module; 737 return 0; 738 739 fail_put_module: 740 module_put(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(&sdev->sdev_gendev); 759 module_put(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(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(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(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(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(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(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