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 error = scsi_init_sense_cache(shost); 217 if (error) 218 goto fail; 219 220 if (shost_use_blk_mq(shost)) { 221 error = scsi_mq_setup_tags(shost); 222 if (error) 223 goto fail; 224 } else { 225 shost->bqt = blk_init_tags(shost->can_queue, 226 shost->hostt->tag_alloc_policy); 227 if (!shost->bqt) { 228 error = -ENOMEM; 229 goto fail; 230 } 231 } 232 233 if (!shost->shost_gendev.parent) 234 shost->shost_gendev.parent = dev ? dev : &platform_bus; 235 if (!dma_dev) 236 dma_dev = shost->shost_gendev.parent; 237 238 shost->dma_dev = dma_dev; 239 240 /* 241 * Increase usage count temporarily here so that calling 242 * scsi_autopm_put_host() will trigger runtime idle if there is 243 * nothing else preventing suspending the device. 244 */ 245 pm_runtime_get_noresume(&shost->shost_gendev); 246 pm_runtime_set_active(&shost->shost_gendev); 247 pm_runtime_enable(&shost->shost_gendev); 248 device_enable_async_suspend(&shost->shost_gendev); 249 250 error = device_add(&shost->shost_gendev); 251 if (error) 252 goto out_disable_runtime_pm; 253 254 scsi_host_set_state(shost, SHOST_RUNNING); 255 get_device(shost->shost_gendev.parent); 256 257 device_enable_async_suspend(&shost->shost_dev); 258 259 error = device_add(&shost->shost_dev); 260 if (error) 261 goto out_del_gendev; 262 263 get_device(&shost->shost_gendev); 264 265 if (shost->transportt->host_size) { 266 shost->shost_data = kzalloc(shost->transportt->host_size, 267 GFP_KERNEL); 268 if (shost->shost_data == NULL) { 269 error = -ENOMEM; 270 goto out_del_dev; 271 } 272 } 273 274 if (shost->transportt->create_work_queue) { 275 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 276 "scsi_wq_%d", shost->host_no); 277 shost->work_q = create_singlethread_workqueue( 278 shost->work_q_name); 279 if (!shost->work_q) { 280 error = -EINVAL; 281 goto out_free_shost_data; 282 } 283 } 284 285 error = scsi_sysfs_add_host(shost); 286 if (error) 287 goto out_destroy_host; 288 289 scsi_proc_host_add(shost); 290 scsi_autopm_put_host(shost); 291 return error; 292 293 out_destroy_host: 294 if (shost->work_q) 295 destroy_workqueue(shost->work_q); 296 out_free_shost_data: 297 kfree(shost->shost_data); 298 out_del_dev: 299 device_del(&shost->shost_dev); 300 out_del_gendev: 301 device_del(&shost->shost_gendev); 302 out_disable_runtime_pm: 303 device_disable_async_suspend(&shost->shost_gendev); 304 pm_runtime_disable(&shost->shost_gendev); 305 pm_runtime_set_suspended(&shost->shost_gendev); 306 pm_runtime_put_noidle(&shost->shost_gendev); 307 if (shost_use_blk_mq(shost)) 308 scsi_mq_destroy_tags(shost); 309 fail: 310 return error; 311 } 312 EXPORT_SYMBOL(scsi_add_host_with_dma); 313 314 static void scsi_host_dev_release(struct device *dev) 315 { 316 struct Scsi_Host *shost = dev_to_shost(dev); 317 struct device *parent = dev->parent; 318 319 scsi_proc_hostdir_rm(shost->hostt); 320 321 /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */ 322 rcu_barrier(); 323 324 if (shost->tmf_work_q) 325 destroy_workqueue(shost->tmf_work_q); 326 if (shost->ehandler) 327 kthread_stop(shost->ehandler); 328 if (shost->work_q) 329 destroy_workqueue(shost->work_q); 330 331 if (shost->shost_state == SHOST_CREATED) { 332 /* 333 * Free the shost_dev device name here if scsi_host_alloc() 334 * and scsi_host_put() have been called but neither 335 * scsi_host_add() nor scsi_host_remove() has been called. 336 * This avoids that the memory allocated for the shost_dev 337 * name is leaked. 338 */ 339 kfree(dev_name(&shost->shost_dev)); 340 } 341 342 if (shost_use_blk_mq(shost)) { 343 if (shost->tag_set.tags) 344 scsi_mq_destroy_tags(shost); 345 } else { 346 if (shost->bqt) 347 blk_free_tags(shost->bqt); 348 } 349 350 kfree(shost->shost_data); 351 352 ida_simple_remove(&host_index_ida, shost->host_no); 353 354 if (parent) 355 put_device(parent); 356 kfree(shost); 357 } 358 359 static int shost_eh_deadline = -1; 360 361 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); 362 MODULE_PARM_DESC(eh_deadline, 363 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); 364 365 static struct device_type scsi_host_type = { 366 .name = "scsi_host", 367 .release = scsi_host_dev_release, 368 }; 369 370 /** 371 * scsi_host_alloc - register a scsi host adapter instance. 372 * @sht: pointer to scsi host template 373 * @privsize: extra bytes to allocate for driver 374 * 375 * Note: 376 * Allocate a new Scsi_Host and perform basic initialization. 377 * The host is not published to the scsi midlayer until scsi_add_host 378 * is called. 379 * 380 * Return value: 381 * Pointer to a new Scsi_Host 382 **/ 383 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 384 { 385 struct Scsi_Host *shost; 386 gfp_t gfp_mask = GFP_KERNEL; 387 int index; 388 389 if (sht->unchecked_isa_dma && privsize) 390 gfp_mask |= __GFP_DMA; 391 392 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 393 if (!shost) 394 return NULL; 395 396 shost->host_lock = &shost->default_lock; 397 spin_lock_init(shost->host_lock); 398 shost->shost_state = SHOST_CREATED; 399 INIT_LIST_HEAD(&shost->__devices); 400 INIT_LIST_HEAD(&shost->__targets); 401 INIT_LIST_HEAD(&shost->eh_cmd_q); 402 INIT_LIST_HEAD(&shost->starved_list); 403 init_waitqueue_head(&shost->host_wait); 404 mutex_init(&shost->scan_mutex); 405 406 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); 407 if (index < 0) 408 goto fail_kfree; 409 shost->host_no = index; 410 411 shost->dma_channel = 0xff; 412 413 /* These three are default values which can be overridden */ 414 shost->max_channel = 0; 415 shost->max_id = 8; 416 shost->max_lun = 8; 417 418 /* Give each shost a default transportt */ 419 shost->transportt = &blank_transport_template; 420 421 /* 422 * All drivers right now should be able to handle 12 byte 423 * commands. Every so often there are requests for 16 byte 424 * commands, but individual low-level drivers need to certify that 425 * they actually do something sensible with such commands. 426 */ 427 shost->max_cmd_len = 12; 428 shost->hostt = sht; 429 shost->this_id = sht->this_id; 430 shost->can_queue = sht->can_queue; 431 shost->sg_tablesize = sht->sg_tablesize; 432 shost->sg_prot_tablesize = sht->sg_prot_tablesize; 433 shost->cmd_per_lun = sht->cmd_per_lun; 434 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 435 shost->use_clustering = sht->use_clustering; 436 shost->no_write_same = sht->no_write_same; 437 438 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) 439 shost->eh_deadline = -1; 440 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { 441 shost_printk(KERN_WARNING, shost, 442 "eh_deadline %u too large, setting to %u\n", 443 shost_eh_deadline, INT_MAX / HZ); 444 shost->eh_deadline = INT_MAX; 445 } else 446 shost->eh_deadline = shost_eh_deadline * HZ; 447 448 if (sht->supported_mode == MODE_UNKNOWN) 449 /* means we didn't set it ... default to INITIATOR */ 450 shost->active_mode = MODE_INITIATOR; 451 else 452 shost->active_mode = sht->supported_mode; 453 454 if (sht->max_host_blocked) 455 shost->max_host_blocked = sht->max_host_blocked; 456 else 457 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 458 459 /* 460 * If the driver imposes no hard sector transfer limit, start at 461 * machine infinity initially. 462 */ 463 if (sht->max_sectors) 464 shost->max_sectors = sht->max_sectors; 465 else 466 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 467 468 /* 469 * assume a 4GB boundary, if not set 470 */ 471 if (sht->dma_boundary) 472 shost->dma_boundary = sht->dma_boundary; 473 else 474 shost->dma_boundary = 0xffffffff; 475 476 shost->use_blk_mq = scsi_use_blk_mq; 477 478 device_initialize(&shost->shost_gendev); 479 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 480 shost->shost_gendev.bus = &scsi_bus_type; 481 shost->shost_gendev.type = &scsi_host_type; 482 483 device_initialize(&shost->shost_dev); 484 shost->shost_dev.parent = &shost->shost_gendev; 485 shost->shost_dev.class = &shost_class; 486 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 487 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 488 489 shost->ehandler = kthread_run(scsi_error_handler, shost, 490 "scsi_eh_%d", shost->host_no); 491 if (IS_ERR(shost->ehandler)) { 492 shost_printk(KERN_WARNING, shost, 493 "error handler thread failed to spawn, error = %ld\n", 494 PTR_ERR(shost->ehandler)); 495 goto fail_index_remove; 496 } 497 498 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", 499 WQ_UNBOUND | WQ_MEM_RECLAIM, 500 1, shost->host_no); 501 if (!shost->tmf_work_q) { 502 shost_printk(KERN_WARNING, shost, 503 "failed to create tmf workq\n"); 504 goto fail_kthread; 505 } 506 scsi_proc_hostdir_add(shost->hostt); 507 return shost; 508 509 fail_kthread: 510 kthread_stop(shost->ehandler); 511 fail_index_remove: 512 ida_simple_remove(&host_index_ida, shost->host_no); 513 fail_kfree: 514 kfree(shost); 515 return NULL; 516 } 517 EXPORT_SYMBOL(scsi_host_alloc); 518 519 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 520 { 521 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 522 523 if (!sht->detect) { 524 printk(KERN_WARNING "scsi_register() called on new-style " 525 "template for driver %s\n", sht->name); 526 dump_stack(); 527 } 528 529 if (shost) 530 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 531 return shost; 532 } 533 EXPORT_SYMBOL(scsi_register); 534 535 void scsi_unregister(struct Scsi_Host *shost) 536 { 537 list_del(&shost->sht_legacy_list); 538 scsi_host_put(shost); 539 } 540 EXPORT_SYMBOL(scsi_unregister); 541 542 static int __scsi_host_match(struct device *dev, const void *data) 543 { 544 struct Scsi_Host *p; 545 const unsigned short *hostnum = data; 546 547 p = class_to_shost(dev); 548 return p->host_no == *hostnum; 549 } 550 551 /** 552 * scsi_host_lookup - get a reference to a Scsi_Host by host no 553 * @hostnum: host number to locate 554 * 555 * Return value: 556 * A pointer to located Scsi_Host or NULL. 557 * 558 * The caller must do a scsi_host_put() to drop the reference 559 * that scsi_host_get() took. The put_device() below dropped 560 * the reference from class_find_device(). 561 **/ 562 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 563 { 564 struct device *cdev; 565 struct Scsi_Host *shost = NULL; 566 567 cdev = class_find_device(&shost_class, NULL, &hostnum, 568 __scsi_host_match); 569 if (cdev) { 570 shost = scsi_host_get(class_to_shost(cdev)); 571 put_device(cdev); 572 } 573 return shost; 574 } 575 EXPORT_SYMBOL(scsi_host_lookup); 576 577 /** 578 * scsi_host_get - inc a Scsi_Host ref count 579 * @shost: Pointer to Scsi_Host to inc. 580 **/ 581 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 582 { 583 if ((shost->shost_state == SHOST_DEL) || 584 !get_device(&shost->shost_gendev)) 585 return NULL; 586 return shost; 587 } 588 EXPORT_SYMBOL(scsi_host_get); 589 590 /** 591 * scsi_host_put - dec a Scsi_Host ref count 592 * @shost: Pointer to Scsi_Host to dec. 593 **/ 594 void scsi_host_put(struct Scsi_Host *shost) 595 { 596 put_device(&shost->shost_gendev); 597 } 598 EXPORT_SYMBOL(scsi_host_put); 599 600 int scsi_init_hosts(void) 601 { 602 return class_register(&shost_class); 603 } 604 605 void scsi_exit_hosts(void) 606 { 607 class_unregister(&shost_class); 608 ida_destroy(&host_index_ida); 609 } 610 611 int scsi_is_host_device(const struct device *dev) 612 { 613 return dev->type == &scsi_host_type; 614 } 615 EXPORT_SYMBOL(scsi_is_host_device); 616 617 /** 618 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 619 * @shost: Pointer to Scsi_Host. 620 * @work: Work to queue for execution. 621 * 622 * Return value: 623 * 1 - work queued for execution 624 * 0 - work is already queued 625 * -EINVAL - work queue doesn't exist 626 **/ 627 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 628 { 629 if (unlikely(!shost->work_q)) { 630 shost_printk(KERN_ERR, shost, 631 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 632 "when no workqueue created.\n", shost->hostt->name); 633 dump_stack(); 634 635 return -EINVAL; 636 } 637 638 return queue_work(shost->work_q, work); 639 } 640 EXPORT_SYMBOL_GPL(scsi_queue_work); 641 642 /** 643 * scsi_flush_work - Flush a Scsi_Host's workqueue. 644 * @shost: Pointer to Scsi_Host. 645 **/ 646 void scsi_flush_work(struct Scsi_Host *shost) 647 { 648 if (!shost->work_q) { 649 shost_printk(KERN_ERR, shost, 650 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 651 "when no workqueue created.\n", shost->hostt->name); 652 dump_stack(); 653 return; 654 } 655 656 flush_workqueue(shost->work_q); 657 } 658 EXPORT_SYMBOL_GPL(scsi_flush_work); 659