1 /* 2 * hosts.c Copyright (C) 1992 Drew Eckhardt 3 * Copyright (C) 1993, 1994, 1995 Eric Youngdale 4 * Copyright (C) 2002-2003 Christoph Hellwig 5 * 6 * mid to lowlevel SCSI driver interface 7 * Initial versions: Drew Eckhardt 8 * Subsequent revisions: Eric Youngdale 9 * 10 * <drew@colorado.edu> 11 * 12 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli 13 * Added QLOGIC QLA1280 SCSI controller kernel host support. 14 * August 4, 1999 Fred Lewis, Intel DuPont 15 * 16 * Updated to reflect the new initialization scheme for the higher 17 * level of scsi drivers (sd/sr/st) 18 * September 17, 2000 Torben Mathiasen <tmm@image.dk> 19 * 20 * Restructured scsi_host lists and associated functions. 21 * September 04, 2002 Mike Anderson (andmike@us.ibm.com) 22 */ 23 24 #include <linux/module.h> 25 #include <linux/blkdev.h> 26 #include <linux/kernel.h> 27 #include <linux/slab.h> 28 #include <linux/kthread.h> 29 #include <linux/string.h> 30 #include <linux/mm.h> 31 #include <linux/init.h> 32 #include <linux/completion.h> 33 #include <linux/transport_class.h> 34 #include <linux/platform_device.h> 35 #include <linux/pm_runtime.h> 36 #include <linux/idr.h> 37 #include <scsi/scsi_device.h> 38 #include <scsi/scsi_host.h> 39 #include <scsi/scsi_transport.h> 40 41 #include "scsi_priv.h" 42 #include "scsi_logging.h" 43 44 45 static DEFINE_IDA(host_index_ida); 46 47 48 static void scsi_host_cls_release(struct device *dev) 49 { 50 put_device(&class_to_shost(dev)->shost_gendev); 51 } 52 53 static struct class shost_class = { 54 .name = "scsi_host", 55 .dev_release = scsi_host_cls_release, 56 }; 57 58 /** 59 * scsi_host_set_state - Take the given host through the host state model. 60 * @shost: scsi host to change the state of. 61 * @state: state to change to. 62 * 63 * Returns zero if unsuccessful or an error if the requested 64 * transition is illegal. 65 **/ 66 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) 67 { 68 enum scsi_host_state oldstate = shost->shost_state; 69 70 if (state == oldstate) 71 return 0; 72 73 switch (state) { 74 case SHOST_CREATED: 75 /* There are no legal states that come back to 76 * created. This is the manually initialised start 77 * state */ 78 goto illegal; 79 80 case SHOST_RUNNING: 81 switch (oldstate) { 82 case SHOST_CREATED: 83 case SHOST_RECOVERY: 84 break; 85 default: 86 goto illegal; 87 } 88 break; 89 90 case SHOST_RECOVERY: 91 switch (oldstate) { 92 case SHOST_RUNNING: 93 break; 94 default: 95 goto illegal; 96 } 97 break; 98 99 case SHOST_CANCEL: 100 switch (oldstate) { 101 case SHOST_CREATED: 102 case SHOST_RUNNING: 103 case SHOST_CANCEL_RECOVERY: 104 break; 105 default: 106 goto illegal; 107 } 108 break; 109 110 case SHOST_DEL: 111 switch (oldstate) { 112 case SHOST_CANCEL: 113 case SHOST_DEL_RECOVERY: 114 break; 115 default: 116 goto illegal; 117 } 118 break; 119 120 case SHOST_CANCEL_RECOVERY: 121 switch (oldstate) { 122 case SHOST_CANCEL: 123 case SHOST_RECOVERY: 124 break; 125 default: 126 goto illegal; 127 } 128 break; 129 130 case SHOST_DEL_RECOVERY: 131 switch (oldstate) { 132 case SHOST_CANCEL_RECOVERY: 133 break; 134 default: 135 goto illegal; 136 } 137 break; 138 } 139 shost->shost_state = state; 140 return 0; 141 142 illegal: 143 SCSI_LOG_ERROR_RECOVERY(1, 144 shost_printk(KERN_ERR, shost, 145 "Illegal host state transition" 146 "%s->%s\n", 147 scsi_host_state_name(oldstate), 148 scsi_host_state_name(state))); 149 return -EINVAL; 150 } 151 EXPORT_SYMBOL(scsi_host_set_state); 152 153 /** 154 * scsi_remove_host - remove a scsi host 155 * @shost: a pointer to a scsi host to remove 156 **/ 157 void scsi_remove_host(struct Scsi_Host *shost) 158 { 159 unsigned long flags; 160 161 mutex_lock(&shost->scan_mutex); 162 spin_lock_irqsave(shost->host_lock, flags); 163 if (scsi_host_set_state(shost, SHOST_CANCEL)) 164 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { 165 spin_unlock_irqrestore(shost->host_lock, flags); 166 mutex_unlock(&shost->scan_mutex); 167 return; 168 } 169 spin_unlock_irqrestore(shost->host_lock, flags); 170 171 scsi_autopm_get_host(shost); 172 flush_workqueue(shost->tmf_work_q); 173 scsi_forget_host(shost); 174 mutex_unlock(&shost->scan_mutex); 175 scsi_proc_host_rm(shost); 176 177 spin_lock_irqsave(shost->host_lock, flags); 178 if (scsi_host_set_state(shost, SHOST_DEL)) 179 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); 180 spin_unlock_irqrestore(shost->host_lock, flags); 181 182 transport_unregister_device(&shost->shost_gendev); 183 device_unregister(&shost->shost_dev); 184 device_del(&shost->shost_gendev); 185 } 186 EXPORT_SYMBOL(scsi_remove_host); 187 188 /** 189 * scsi_add_host_with_dma - add a scsi host with dma device 190 * @shost: scsi host pointer to add 191 * @dev: a struct device of type scsi class 192 * @dma_dev: dma device for the host 193 * 194 * Note: You rarely need to worry about this unless you're in a 195 * virtualised host environments, so use the simpler scsi_add_host() 196 * function instead. 197 * 198 * Return value: 199 * 0 on success / != 0 for error 200 **/ 201 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, 202 struct device *dma_dev) 203 { 204 struct scsi_host_template *sht = shost->hostt; 205 int error = -EINVAL; 206 207 shost_printk(KERN_INFO, shost, "%s\n", 208 sht->info ? sht->info(shost) : sht->name); 209 210 if (!shost->can_queue) { 211 shost_printk(KERN_ERR, shost, 212 "can_queue = 0 no longer supported\n"); 213 goto fail; 214 } 215 216 if (shost_use_blk_mq(shost)) { 217 error = scsi_mq_setup_tags(shost); 218 if (error) 219 goto fail; 220 } else { 221 shost->bqt = blk_init_tags(shost->can_queue, 222 shost->hostt->tag_alloc_policy); 223 if (!shost->bqt) { 224 error = -ENOMEM; 225 goto fail; 226 } 227 } 228 229 /* 230 * Note that we allocate the freelist even for the MQ case for now, 231 * as we need a command set aside for scsi_reset_provider. Having 232 * the full host freelist and one command available for that is a 233 * little heavy-handed, but avoids introducing a special allocator 234 * just for this. Eventually the structure of scsi_reset_provider 235 * will need a major overhaul. 236 */ 237 error = scsi_setup_command_freelist(shost); 238 if (error) 239 goto out_destroy_tags; 240 241 242 if (!shost->shost_gendev.parent) 243 shost->shost_gendev.parent = dev ? dev : &platform_bus; 244 if (!dma_dev) 245 dma_dev = shost->shost_gendev.parent; 246 247 shost->dma_dev = dma_dev; 248 249 /* 250 * Increase usage count temporarily here so that calling 251 * scsi_autopm_put_host() will trigger runtime idle if there is 252 * nothing else preventing suspending the device. 253 */ 254 pm_runtime_get_noresume(&shost->shost_gendev); 255 pm_runtime_set_active(&shost->shost_gendev); 256 pm_runtime_enable(&shost->shost_gendev); 257 device_enable_async_suspend(&shost->shost_gendev); 258 259 error = device_add(&shost->shost_gendev); 260 if (error) 261 goto out_destroy_freelist; 262 263 scsi_host_set_state(shost, SHOST_RUNNING); 264 get_device(shost->shost_gendev.parent); 265 266 device_enable_async_suspend(&shost->shost_dev); 267 268 error = device_add(&shost->shost_dev); 269 if (error) 270 goto out_del_gendev; 271 272 get_device(&shost->shost_gendev); 273 274 if (shost->transportt->host_size) { 275 shost->shost_data = kzalloc(shost->transportt->host_size, 276 GFP_KERNEL); 277 if (shost->shost_data == NULL) { 278 error = -ENOMEM; 279 goto out_del_dev; 280 } 281 } 282 283 if (shost->transportt->create_work_queue) { 284 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 285 "scsi_wq_%d", shost->host_no); 286 shost->work_q = create_singlethread_workqueue( 287 shost->work_q_name); 288 if (!shost->work_q) { 289 error = -EINVAL; 290 goto out_free_shost_data; 291 } 292 } 293 294 error = scsi_sysfs_add_host(shost); 295 if (error) 296 goto out_destroy_host; 297 298 scsi_proc_host_add(shost); 299 scsi_autopm_put_host(shost); 300 return error; 301 302 out_destroy_host: 303 if (shost->work_q) 304 destroy_workqueue(shost->work_q); 305 out_free_shost_data: 306 kfree(shost->shost_data); 307 out_del_dev: 308 device_del(&shost->shost_dev); 309 out_del_gendev: 310 device_del(&shost->shost_gendev); 311 out_destroy_freelist: 312 device_disable_async_suspend(&shost->shost_gendev); 313 pm_runtime_disable(&shost->shost_gendev); 314 pm_runtime_set_suspended(&shost->shost_gendev); 315 pm_runtime_put_noidle(&shost->shost_gendev); 316 scsi_destroy_command_freelist(shost); 317 out_destroy_tags: 318 if (shost_use_blk_mq(shost)) 319 scsi_mq_destroy_tags(shost); 320 fail: 321 return error; 322 } 323 EXPORT_SYMBOL(scsi_add_host_with_dma); 324 325 static void scsi_host_dev_release(struct device *dev) 326 { 327 struct Scsi_Host *shost = dev_to_shost(dev); 328 struct device *parent = dev->parent; 329 struct request_queue *q; 330 void *queuedata; 331 332 scsi_proc_hostdir_rm(shost->hostt); 333 334 if (shost->tmf_work_q) 335 destroy_workqueue(shost->tmf_work_q); 336 if (shost->ehandler) 337 kthread_stop(shost->ehandler); 338 if (shost->work_q) 339 destroy_workqueue(shost->work_q); 340 q = shost->uspace_req_q; 341 if (q) { 342 queuedata = q->queuedata; 343 blk_cleanup_queue(q); 344 kfree(queuedata); 345 } 346 347 if (shost->shost_state == SHOST_CREATED) { 348 /* 349 * Free the shost_dev device name here if scsi_host_alloc() 350 * and scsi_host_put() have been called but neither 351 * scsi_host_add() nor scsi_host_remove() has been called. 352 * This avoids that the memory allocated for the shost_dev 353 * name is leaked. 354 */ 355 kfree(dev_name(&shost->shost_dev)); 356 } 357 358 scsi_destroy_command_freelist(shost); 359 if (shost_use_blk_mq(shost)) { 360 if (shost->tag_set.tags) 361 scsi_mq_destroy_tags(shost); 362 } else { 363 if (shost->bqt) 364 blk_free_tags(shost->bqt); 365 } 366 367 kfree(shost->shost_data); 368 369 ida_simple_remove(&host_index_ida, shost->host_no); 370 371 if (parent) 372 put_device(parent); 373 kfree(shost); 374 } 375 376 static int shost_eh_deadline = -1; 377 378 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); 379 MODULE_PARM_DESC(eh_deadline, 380 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); 381 382 static struct device_type scsi_host_type = { 383 .name = "scsi_host", 384 .release = scsi_host_dev_release, 385 }; 386 387 /** 388 * scsi_host_alloc - register a scsi host adapter instance. 389 * @sht: pointer to scsi host template 390 * @privsize: extra bytes to allocate for driver 391 * 392 * Note: 393 * Allocate a new Scsi_Host and perform basic initialization. 394 * The host is not published to the scsi midlayer until scsi_add_host 395 * is called. 396 * 397 * Return value: 398 * Pointer to a new Scsi_Host 399 **/ 400 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 401 { 402 struct Scsi_Host *shost; 403 gfp_t gfp_mask = GFP_KERNEL; 404 int index; 405 406 if (sht->unchecked_isa_dma && privsize) 407 gfp_mask |= __GFP_DMA; 408 409 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 410 if (!shost) 411 return NULL; 412 413 shost->host_lock = &shost->default_lock; 414 spin_lock_init(shost->host_lock); 415 shost->shost_state = SHOST_CREATED; 416 INIT_LIST_HEAD(&shost->__devices); 417 INIT_LIST_HEAD(&shost->__targets); 418 INIT_LIST_HEAD(&shost->eh_cmd_q); 419 INIT_LIST_HEAD(&shost->starved_list); 420 init_waitqueue_head(&shost->host_wait); 421 mutex_init(&shost->scan_mutex); 422 423 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); 424 if (index < 0) 425 goto fail_kfree; 426 shost->host_no = index; 427 428 shost->dma_channel = 0xff; 429 430 /* These three are default values which can be overridden */ 431 shost->max_channel = 0; 432 shost->max_id = 8; 433 shost->max_lun = 8; 434 435 /* Give each shost a default transportt */ 436 shost->transportt = &blank_transport_template; 437 438 /* 439 * All drivers right now should be able to handle 12 byte 440 * commands. Every so often there are requests for 16 byte 441 * commands, but individual low-level drivers need to certify that 442 * they actually do something sensible with such commands. 443 */ 444 shost->max_cmd_len = 12; 445 shost->hostt = sht; 446 shost->this_id = sht->this_id; 447 shost->can_queue = sht->can_queue; 448 shost->sg_tablesize = sht->sg_tablesize; 449 shost->sg_prot_tablesize = sht->sg_prot_tablesize; 450 shost->cmd_per_lun = sht->cmd_per_lun; 451 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 452 shost->use_clustering = sht->use_clustering; 453 shost->no_write_same = sht->no_write_same; 454 455 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) 456 shost->eh_deadline = -1; 457 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { 458 shost_printk(KERN_WARNING, shost, 459 "eh_deadline %u too large, setting to %u\n", 460 shost_eh_deadline, INT_MAX / HZ); 461 shost->eh_deadline = INT_MAX; 462 } else 463 shost->eh_deadline = shost_eh_deadline * HZ; 464 465 if (sht->supported_mode == MODE_UNKNOWN) 466 /* means we didn't set it ... default to INITIATOR */ 467 shost->active_mode = MODE_INITIATOR; 468 else 469 shost->active_mode = sht->supported_mode; 470 471 if (sht->max_host_blocked) 472 shost->max_host_blocked = sht->max_host_blocked; 473 else 474 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 475 476 /* 477 * If the driver imposes no hard sector transfer limit, start at 478 * machine infinity initially. 479 */ 480 if (sht->max_sectors) 481 shost->max_sectors = sht->max_sectors; 482 else 483 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 484 485 /* 486 * assume a 4GB boundary, if not set 487 */ 488 if (sht->dma_boundary) 489 shost->dma_boundary = sht->dma_boundary; 490 else 491 shost->dma_boundary = 0xffffffff; 492 493 shost->use_blk_mq = scsi_use_blk_mq; 494 495 device_initialize(&shost->shost_gendev); 496 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 497 shost->shost_gendev.bus = &scsi_bus_type; 498 shost->shost_gendev.type = &scsi_host_type; 499 500 device_initialize(&shost->shost_dev); 501 shost->shost_dev.parent = &shost->shost_gendev; 502 shost->shost_dev.class = &shost_class; 503 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 504 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 505 506 shost->ehandler = kthread_run(scsi_error_handler, shost, 507 "scsi_eh_%d", shost->host_no); 508 if (IS_ERR(shost->ehandler)) { 509 shost_printk(KERN_WARNING, shost, 510 "error handler thread failed to spawn, error = %ld\n", 511 PTR_ERR(shost->ehandler)); 512 goto fail_index_remove; 513 } 514 515 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", 516 WQ_UNBOUND | WQ_MEM_RECLAIM, 517 1, shost->host_no); 518 if (!shost->tmf_work_q) { 519 shost_printk(KERN_WARNING, shost, 520 "failed to create tmf workq\n"); 521 goto fail_kthread; 522 } 523 scsi_proc_hostdir_add(shost->hostt); 524 return shost; 525 526 fail_kthread: 527 kthread_stop(shost->ehandler); 528 fail_index_remove: 529 ida_simple_remove(&host_index_ida, shost->host_no); 530 fail_kfree: 531 kfree(shost); 532 return NULL; 533 } 534 EXPORT_SYMBOL(scsi_host_alloc); 535 536 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 537 { 538 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 539 540 if (!sht->detect) { 541 printk(KERN_WARNING "scsi_register() called on new-style " 542 "template for driver %s\n", sht->name); 543 dump_stack(); 544 } 545 546 if (shost) 547 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 548 return shost; 549 } 550 EXPORT_SYMBOL(scsi_register); 551 552 void scsi_unregister(struct Scsi_Host *shost) 553 { 554 list_del(&shost->sht_legacy_list); 555 scsi_host_put(shost); 556 } 557 EXPORT_SYMBOL(scsi_unregister); 558 559 static int __scsi_host_match(struct device *dev, const void *data) 560 { 561 struct Scsi_Host *p; 562 const unsigned short *hostnum = data; 563 564 p = class_to_shost(dev); 565 return p->host_no == *hostnum; 566 } 567 568 /** 569 * scsi_host_lookup - get a reference to a Scsi_Host by host no 570 * @hostnum: host number to locate 571 * 572 * Return value: 573 * A pointer to located Scsi_Host or NULL. 574 * 575 * The caller must do a scsi_host_put() to drop the reference 576 * that scsi_host_get() took. The put_device() below dropped 577 * the reference from class_find_device(). 578 **/ 579 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 580 { 581 struct device *cdev; 582 struct Scsi_Host *shost = NULL; 583 584 cdev = class_find_device(&shost_class, NULL, &hostnum, 585 __scsi_host_match); 586 if (cdev) { 587 shost = scsi_host_get(class_to_shost(cdev)); 588 put_device(cdev); 589 } 590 return shost; 591 } 592 EXPORT_SYMBOL(scsi_host_lookup); 593 594 /** 595 * scsi_host_get - inc a Scsi_Host ref count 596 * @shost: Pointer to Scsi_Host to inc. 597 **/ 598 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 599 { 600 if ((shost->shost_state == SHOST_DEL) || 601 !get_device(&shost->shost_gendev)) 602 return NULL; 603 return shost; 604 } 605 EXPORT_SYMBOL(scsi_host_get); 606 607 /** 608 * scsi_host_put - dec a Scsi_Host ref count 609 * @shost: Pointer to Scsi_Host to dec. 610 **/ 611 void scsi_host_put(struct Scsi_Host *shost) 612 { 613 put_device(&shost->shost_gendev); 614 } 615 EXPORT_SYMBOL(scsi_host_put); 616 617 int scsi_init_hosts(void) 618 { 619 return class_register(&shost_class); 620 } 621 622 void scsi_exit_hosts(void) 623 { 624 class_unregister(&shost_class); 625 ida_destroy(&host_index_ida); 626 } 627 628 int scsi_is_host_device(const struct device *dev) 629 { 630 return dev->type == &scsi_host_type; 631 } 632 EXPORT_SYMBOL(scsi_is_host_device); 633 634 /** 635 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 636 * @shost: Pointer to Scsi_Host. 637 * @work: Work to queue for execution. 638 * 639 * Return value: 640 * 1 - work queued for execution 641 * 0 - work is already queued 642 * -EINVAL - work queue doesn't exist 643 **/ 644 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 645 { 646 if (unlikely(!shost->work_q)) { 647 shost_printk(KERN_ERR, shost, 648 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 649 "when no workqueue created.\n", shost->hostt->name); 650 dump_stack(); 651 652 return -EINVAL; 653 } 654 655 return queue_work(shost->work_q, work); 656 } 657 EXPORT_SYMBOL_GPL(scsi_queue_work); 658 659 /** 660 * scsi_flush_work - Flush a Scsi_Host's workqueue. 661 * @shost: Pointer to Scsi_Host. 662 **/ 663 void scsi_flush_work(struct Scsi_Host *shost) 664 { 665 if (!shost->work_q) { 666 shost_printk(KERN_ERR, shost, 667 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 668 "when no workqueue created.\n", shost->hostt->name); 669 dump_stack(); 670 return; 671 } 672 673 flush_workqueue(shost->work_q); 674 } 675 EXPORT_SYMBOL_GPL(scsi_flush_work); 676