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 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 atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* host_no for next new host */ 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 printk(KERN_INFO "scsi%d : %s\n", shost->host_no, 208 sht->info ? sht->info(shost) : sht->name); 209 210 if (!shost->can_queue) { 211 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", 212 sht->name); 213 goto fail; 214 } 215 216 error = scsi_setup_command_freelist(shost); 217 if (error) 218 goto fail; 219 220 if (!shost->shost_gendev.parent) 221 shost->shost_gendev.parent = dev ? dev : &platform_bus; 222 if (!dma_dev) 223 dma_dev = shost->shost_gendev.parent; 224 225 shost->dma_dev = dma_dev; 226 227 error = device_add(&shost->shost_gendev); 228 if (error) 229 goto out; 230 231 pm_runtime_set_active(&shost->shost_gendev); 232 pm_runtime_enable(&shost->shost_gendev); 233 device_enable_async_suspend(&shost->shost_gendev); 234 235 scsi_host_set_state(shost, SHOST_RUNNING); 236 get_device(shost->shost_gendev.parent); 237 238 device_enable_async_suspend(&shost->shost_dev); 239 240 error = device_add(&shost->shost_dev); 241 if (error) 242 goto out_del_gendev; 243 244 get_device(&shost->shost_gendev); 245 246 if (shost->transportt->host_size) { 247 shost->shost_data = kzalloc(shost->transportt->host_size, 248 GFP_KERNEL); 249 if (shost->shost_data == NULL) { 250 error = -ENOMEM; 251 goto out_del_dev; 252 } 253 } 254 255 if (shost->transportt->create_work_queue) { 256 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 257 "scsi_wq_%d", shost->host_no); 258 shost->work_q = create_singlethread_workqueue( 259 shost->work_q_name); 260 if (!shost->work_q) { 261 error = -EINVAL; 262 goto out_free_shost_data; 263 } 264 } 265 266 error = scsi_sysfs_add_host(shost); 267 if (error) 268 goto out_destroy_host; 269 270 scsi_proc_host_add(shost); 271 return error; 272 273 out_destroy_host: 274 if (shost->work_q) 275 destroy_workqueue(shost->work_q); 276 out_free_shost_data: 277 kfree(shost->shost_data); 278 out_del_dev: 279 device_del(&shost->shost_dev); 280 out_del_gendev: 281 device_del(&shost->shost_gendev); 282 out: 283 scsi_destroy_command_freelist(shost); 284 fail: 285 return error; 286 } 287 EXPORT_SYMBOL(scsi_add_host_with_dma); 288 289 static void scsi_host_dev_release(struct device *dev) 290 { 291 struct Scsi_Host *shost = dev_to_shost(dev); 292 struct device *parent = dev->parent; 293 struct request_queue *q; 294 void *queuedata; 295 296 scsi_proc_hostdir_rm(shost->hostt); 297 298 if (shost->tmf_work_q) 299 destroy_workqueue(shost->tmf_work_q); 300 if (shost->ehandler) 301 kthread_stop(shost->ehandler); 302 if (shost->work_q) 303 destroy_workqueue(shost->work_q); 304 q = shost->uspace_req_q; 305 if (q) { 306 queuedata = q->queuedata; 307 blk_cleanup_queue(q); 308 kfree(queuedata); 309 } 310 311 scsi_destroy_command_freelist(shost); 312 if (shost->bqt) 313 blk_free_tags(shost->bqt); 314 315 kfree(shost->shost_data); 316 317 if (parent) 318 put_device(parent); 319 kfree(shost); 320 } 321 322 static int shost_eh_deadline = -1; 323 324 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); 325 MODULE_PARM_DESC(eh_deadline, 326 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); 327 328 static struct device_type scsi_host_type = { 329 .name = "scsi_host", 330 .release = scsi_host_dev_release, 331 }; 332 333 /** 334 * scsi_host_alloc - register a scsi host adapter instance. 335 * @sht: pointer to scsi host template 336 * @privsize: extra bytes to allocate for driver 337 * 338 * Note: 339 * Allocate a new Scsi_Host and perform basic initialization. 340 * The host is not published to the scsi midlayer until scsi_add_host 341 * is called. 342 * 343 * Return value: 344 * Pointer to a new Scsi_Host 345 **/ 346 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 347 { 348 struct Scsi_Host *shost; 349 gfp_t gfp_mask = GFP_KERNEL; 350 351 if (sht->unchecked_isa_dma && privsize) 352 gfp_mask |= __GFP_DMA; 353 354 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 355 if (!shost) 356 return NULL; 357 358 shost->host_lock = &shost->default_lock; 359 spin_lock_init(shost->host_lock); 360 shost->shost_state = SHOST_CREATED; 361 INIT_LIST_HEAD(&shost->__devices); 362 INIT_LIST_HEAD(&shost->__targets); 363 INIT_LIST_HEAD(&shost->eh_cmd_q); 364 INIT_LIST_HEAD(&shost->starved_list); 365 init_waitqueue_head(&shost->host_wait); 366 mutex_init(&shost->scan_mutex); 367 368 /* 369 * subtract one because we increment first then return, but we need to 370 * know what the next host number was before increment 371 */ 372 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; 373 shost->dma_channel = 0xff; 374 375 /* These three are default values which can be overridden */ 376 shost->max_channel = 0; 377 shost->max_id = 8; 378 shost->max_lun = 8; 379 380 /* Give each shost a default transportt */ 381 shost->transportt = &blank_transport_template; 382 383 /* 384 * All drivers right now should be able to handle 12 byte 385 * commands. Every so often there are requests for 16 byte 386 * commands, but individual low-level drivers need to certify that 387 * they actually do something sensible with such commands. 388 */ 389 shost->max_cmd_len = 12; 390 shost->hostt = sht; 391 shost->this_id = sht->this_id; 392 shost->can_queue = sht->can_queue; 393 shost->sg_tablesize = sht->sg_tablesize; 394 shost->sg_prot_tablesize = sht->sg_prot_tablesize; 395 shost->cmd_per_lun = sht->cmd_per_lun; 396 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 397 shost->use_clustering = sht->use_clustering; 398 shost->ordered_tag = sht->ordered_tag; 399 shost->no_write_same = sht->no_write_same; 400 401 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) 402 shost->eh_deadline = -1; 403 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { 404 shost_printk(KERN_WARNING, shost, 405 "eh_deadline %u too large, setting to %u\n", 406 shost_eh_deadline, INT_MAX / HZ); 407 shost->eh_deadline = INT_MAX; 408 } else 409 shost->eh_deadline = shost_eh_deadline * HZ; 410 411 if (sht->supported_mode == MODE_UNKNOWN) 412 /* means we didn't set it ... default to INITIATOR */ 413 shost->active_mode = MODE_INITIATOR; 414 else 415 shost->active_mode = sht->supported_mode; 416 417 if (sht->max_host_blocked) 418 shost->max_host_blocked = sht->max_host_blocked; 419 else 420 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 421 422 /* 423 * If the driver imposes no hard sector transfer limit, start at 424 * machine infinity initially. 425 */ 426 if (sht->max_sectors) 427 shost->max_sectors = sht->max_sectors; 428 else 429 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 430 431 /* 432 * assume a 4GB boundary, if not set 433 */ 434 if (sht->dma_boundary) 435 shost->dma_boundary = sht->dma_boundary; 436 else 437 shost->dma_boundary = 0xffffffff; 438 439 device_initialize(&shost->shost_gendev); 440 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 441 shost->shost_gendev.bus = &scsi_bus_type; 442 shost->shost_gendev.type = &scsi_host_type; 443 444 device_initialize(&shost->shost_dev); 445 shost->shost_dev.parent = &shost->shost_gendev; 446 shost->shost_dev.class = &shost_class; 447 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 448 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 449 450 shost->ehandler = kthread_run(scsi_error_handler, shost, 451 "scsi_eh_%d", shost->host_no); 452 if (IS_ERR(shost->ehandler)) { 453 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n", 454 shost->host_no, PTR_ERR(shost->ehandler)); 455 goto fail_kfree; 456 } 457 458 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", 459 WQ_UNBOUND | WQ_MEM_RECLAIM, 460 1, shost->host_no); 461 if (!shost->tmf_work_q) { 462 printk(KERN_WARNING "scsi%d: failed to create tmf workq\n", 463 shost->host_no); 464 goto fail_kthread; 465 } 466 scsi_proc_hostdir_add(shost->hostt); 467 return shost; 468 469 fail_kthread: 470 kthread_stop(shost->ehandler); 471 fail_kfree: 472 kfree(shost); 473 return NULL; 474 } 475 EXPORT_SYMBOL(scsi_host_alloc); 476 477 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 478 { 479 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 480 481 if (!sht->detect) { 482 printk(KERN_WARNING "scsi_register() called on new-style " 483 "template for driver %s\n", sht->name); 484 dump_stack(); 485 } 486 487 if (shost) 488 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 489 return shost; 490 } 491 EXPORT_SYMBOL(scsi_register); 492 493 void scsi_unregister(struct Scsi_Host *shost) 494 { 495 list_del(&shost->sht_legacy_list); 496 scsi_host_put(shost); 497 } 498 EXPORT_SYMBOL(scsi_unregister); 499 500 static int __scsi_host_match(struct device *dev, const void *data) 501 { 502 struct Scsi_Host *p; 503 const unsigned short *hostnum = data; 504 505 p = class_to_shost(dev); 506 return p->host_no == *hostnum; 507 } 508 509 /** 510 * scsi_host_lookup - get a reference to a Scsi_Host by host no 511 * @hostnum: host number to locate 512 * 513 * Return value: 514 * A pointer to located Scsi_Host or NULL. 515 * 516 * The caller must do a scsi_host_put() to drop the reference 517 * that scsi_host_get() took. The put_device() below dropped 518 * the reference from class_find_device(). 519 **/ 520 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 521 { 522 struct device *cdev; 523 struct Scsi_Host *shost = NULL; 524 525 cdev = class_find_device(&shost_class, NULL, &hostnum, 526 __scsi_host_match); 527 if (cdev) { 528 shost = scsi_host_get(class_to_shost(cdev)); 529 put_device(cdev); 530 } 531 return shost; 532 } 533 EXPORT_SYMBOL(scsi_host_lookup); 534 535 /** 536 * scsi_host_get - inc a Scsi_Host ref count 537 * @shost: Pointer to Scsi_Host to inc. 538 **/ 539 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 540 { 541 if ((shost->shost_state == SHOST_DEL) || 542 !get_device(&shost->shost_gendev)) 543 return NULL; 544 return shost; 545 } 546 EXPORT_SYMBOL(scsi_host_get); 547 548 /** 549 * scsi_host_put - dec a Scsi_Host ref count 550 * @shost: Pointer to Scsi_Host to dec. 551 **/ 552 void scsi_host_put(struct Scsi_Host *shost) 553 { 554 put_device(&shost->shost_gendev); 555 } 556 EXPORT_SYMBOL(scsi_host_put); 557 558 int scsi_init_hosts(void) 559 { 560 return class_register(&shost_class); 561 } 562 563 void scsi_exit_hosts(void) 564 { 565 class_unregister(&shost_class); 566 } 567 568 int scsi_is_host_device(const struct device *dev) 569 { 570 return dev->type == &scsi_host_type; 571 } 572 EXPORT_SYMBOL(scsi_is_host_device); 573 574 /** 575 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 576 * @shost: Pointer to Scsi_Host. 577 * @work: Work to queue for execution. 578 * 579 * Return value: 580 * 1 - work queued for execution 581 * 0 - work is already queued 582 * -EINVAL - work queue doesn't exist 583 **/ 584 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 585 { 586 if (unlikely(!shost->work_q)) { 587 printk(KERN_ERR 588 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 589 "when no workqueue created.\n", shost->hostt->name); 590 dump_stack(); 591 592 return -EINVAL; 593 } 594 595 return queue_work(shost->work_q, work); 596 } 597 EXPORT_SYMBOL_GPL(scsi_queue_work); 598 599 /** 600 * scsi_flush_work - Flush a Scsi_Host's workqueue. 601 * @shost: Pointer to Scsi_Host. 602 **/ 603 void scsi_flush_work(struct Scsi_Host *shost) 604 { 605 if (!shost->work_q) { 606 printk(KERN_ERR 607 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 608 "when no workqueue created.\n", shost->hostt->name); 609 dump_stack(); 610 return; 611 } 612 613 flush_workqueue(shost->work_q); 614 } 615 EXPORT_SYMBOL_GPL(scsi_flush_work); 616