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 scsi_forget_host(shost); 173 mutex_unlock(&shost->scan_mutex); 174 scsi_proc_host_rm(shost); 175 176 spin_lock_irqsave(shost->host_lock, flags); 177 if (scsi_host_set_state(shost, SHOST_DEL)) 178 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); 179 spin_unlock_irqrestore(shost->host_lock, flags); 180 181 transport_unregister_device(&shost->shost_gendev); 182 device_unregister(&shost->shost_dev); 183 device_del(&shost->shost_gendev); 184 } 185 EXPORT_SYMBOL(scsi_remove_host); 186 187 /** 188 * scsi_add_host_with_dma - add a scsi host with dma device 189 * @shost: scsi host pointer to add 190 * @dev: a struct device of type scsi class 191 * @dma_dev: dma device for the host 192 * 193 * Note: You rarely need to worry about this unless you're in a 194 * virtualised host environments, so use the simpler scsi_add_host() 195 * function instead. 196 * 197 * Return value: 198 * 0 on success / != 0 for error 199 **/ 200 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, 201 struct device *dma_dev) 202 { 203 struct scsi_host_template *sht = shost->hostt; 204 int error = -EINVAL; 205 206 printk(KERN_INFO "scsi%d : %s\n", shost->host_no, 207 sht->info ? sht->info(shost) : sht->name); 208 209 if (!shost->can_queue) { 210 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", 211 sht->name); 212 goto fail; 213 } 214 215 error = scsi_setup_command_freelist(shost); 216 if (error) 217 goto fail; 218 219 if (!shost->shost_gendev.parent) 220 shost->shost_gendev.parent = dev ? dev : &platform_bus; 221 if (!dma_dev) 222 dma_dev = shost->shost_gendev.parent; 223 224 shost->dma_dev = dma_dev; 225 226 error = device_add(&shost->shost_gendev); 227 if (error) 228 goto out; 229 230 pm_runtime_set_active(&shost->shost_gendev); 231 pm_runtime_enable(&shost->shost_gendev); 232 device_enable_async_suspend(&shost->shost_gendev); 233 234 scsi_host_set_state(shost, SHOST_RUNNING); 235 get_device(shost->shost_gendev.parent); 236 237 device_enable_async_suspend(&shost->shost_dev); 238 239 error = device_add(&shost->shost_dev); 240 if (error) 241 goto out_del_gendev; 242 243 get_device(&shost->shost_gendev); 244 245 if (shost->transportt->host_size) { 246 shost->shost_data = kzalloc(shost->transportt->host_size, 247 GFP_KERNEL); 248 if (shost->shost_data == NULL) { 249 error = -ENOMEM; 250 goto out_del_dev; 251 } 252 } 253 254 if (shost->transportt->create_work_queue) { 255 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 256 "scsi_wq_%d", shost->host_no); 257 shost->work_q = create_singlethread_workqueue( 258 shost->work_q_name); 259 if (!shost->work_q) { 260 error = -EINVAL; 261 goto out_free_shost_data; 262 } 263 } 264 265 error = scsi_sysfs_add_host(shost); 266 if (error) 267 goto out_destroy_host; 268 269 scsi_proc_host_add(shost); 270 return error; 271 272 out_destroy_host: 273 if (shost->work_q) 274 destroy_workqueue(shost->work_q); 275 out_free_shost_data: 276 kfree(shost->shost_data); 277 out_del_dev: 278 device_del(&shost->shost_dev); 279 out_del_gendev: 280 device_del(&shost->shost_gendev); 281 out: 282 scsi_destroy_command_freelist(shost); 283 fail: 284 return error; 285 } 286 EXPORT_SYMBOL(scsi_add_host_with_dma); 287 288 static void scsi_host_dev_release(struct device *dev) 289 { 290 struct Scsi_Host *shost = dev_to_shost(dev); 291 struct device *parent = dev->parent; 292 struct request_queue *q; 293 void *queuedata; 294 295 scsi_proc_hostdir_rm(shost->hostt); 296 297 if (shost->ehandler) 298 kthread_stop(shost->ehandler); 299 if (shost->work_q) 300 destroy_workqueue(shost->work_q); 301 q = shost->uspace_req_q; 302 if (q) { 303 queuedata = q->queuedata; 304 blk_cleanup_queue(q); 305 kfree(queuedata); 306 } 307 308 scsi_destroy_command_freelist(shost); 309 if (shost->bqt) 310 blk_free_tags(shost->bqt); 311 312 kfree(shost->shost_data); 313 314 if (parent) 315 put_device(parent); 316 kfree(shost); 317 } 318 319 static struct device_type scsi_host_type = { 320 .name = "scsi_host", 321 .release = scsi_host_dev_release, 322 }; 323 324 /** 325 * scsi_host_alloc - register a scsi host adapter instance. 326 * @sht: pointer to scsi host template 327 * @privsize: extra bytes to allocate for driver 328 * 329 * Note: 330 * Allocate a new Scsi_Host and perform basic initialization. 331 * The host is not published to the scsi midlayer until scsi_add_host 332 * is called. 333 * 334 * Return value: 335 * Pointer to a new Scsi_Host 336 **/ 337 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 338 { 339 struct Scsi_Host *shost; 340 gfp_t gfp_mask = GFP_KERNEL; 341 342 if (sht->unchecked_isa_dma && privsize) 343 gfp_mask |= __GFP_DMA; 344 345 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 346 if (!shost) 347 return NULL; 348 349 shost->host_lock = &shost->default_lock; 350 spin_lock_init(shost->host_lock); 351 shost->shost_state = SHOST_CREATED; 352 INIT_LIST_HEAD(&shost->__devices); 353 INIT_LIST_HEAD(&shost->__targets); 354 INIT_LIST_HEAD(&shost->eh_cmd_q); 355 INIT_LIST_HEAD(&shost->starved_list); 356 init_waitqueue_head(&shost->host_wait); 357 358 mutex_init(&shost->scan_mutex); 359 360 /* 361 * subtract one because we increment first then return, but we need to 362 * know what the next host number was before increment 363 */ 364 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; 365 shost->dma_channel = 0xff; 366 367 /* These three are default values which can be overridden */ 368 shost->max_channel = 0; 369 shost->max_id = 8; 370 shost->max_lun = 8; 371 372 /* Give each shost a default transportt */ 373 shost->transportt = &blank_transport_template; 374 375 /* 376 * All drivers right now should be able to handle 12 byte 377 * commands. Every so often there are requests for 16 byte 378 * commands, but individual low-level drivers need to certify that 379 * they actually do something sensible with such commands. 380 */ 381 shost->max_cmd_len = 12; 382 shost->hostt = sht; 383 shost->this_id = sht->this_id; 384 shost->can_queue = sht->can_queue; 385 shost->sg_tablesize = sht->sg_tablesize; 386 shost->sg_prot_tablesize = sht->sg_prot_tablesize; 387 shost->cmd_per_lun = sht->cmd_per_lun; 388 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 389 shost->use_clustering = sht->use_clustering; 390 shost->ordered_tag = sht->ordered_tag; 391 392 if (sht->supported_mode == MODE_UNKNOWN) 393 /* means we didn't set it ... default to INITIATOR */ 394 shost->active_mode = MODE_INITIATOR; 395 else 396 shost->active_mode = sht->supported_mode; 397 398 if (sht->max_host_blocked) 399 shost->max_host_blocked = sht->max_host_blocked; 400 else 401 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 402 403 /* 404 * If the driver imposes no hard sector transfer limit, start at 405 * machine infinity initially. 406 */ 407 if (sht->max_sectors) 408 shost->max_sectors = sht->max_sectors; 409 else 410 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 411 412 /* 413 * assume a 4GB boundary, if not set 414 */ 415 if (sht->dma_boundary) 416 shost->dma_boundary = sht->dma_boundary; 417 else 418 shost->dma_boundary = 0xffffffff; 419 420 device_initialize(&shost->shost_gendev); 421 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 422 shost->shost_gendev.bus = &scsi_bus_type; 423 shost->shost_gendev.type = &scsi_host_type; 424 425 device_initialize(&shost->shost_dev); 426 shost->shost_dev.parent = &shost->shost_gendev; 427 shost->shost_dev.class = &shost_class; 428 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 429 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 430 431 shost->ehandler = kthread_run(scsi_error_handler, shost, 432 "scsi_eh_%d", shost->host_no); 433 if (IS_ERR(shost->ehandler)) { 434 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n", 435 shost->host_no, PTR_ERR(shost->ehandler)); 436 goto fail_kfree; 437 } 438 439 scsi_proc_hostdir_add(shost->hostt); 440 return shost; 441 442 fail_kfree: 443 kfree(shost); 444 return NULL; 445 } 446 EXPORT_SYMBOL(scsi_host_alloc); 447 448 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 449 { 450 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 451 452 if (!sht->detect) { 453 printk(KERN_WARNING "scsi_register() called on new-style " 454 "template for driver %s\n", sht->name); 455 dump_stack(); 456 } 457 458 if (shost) 459 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 460 return shost; 461 } 462 EXPORT_SYMBOL(scsi_register); 463 464 void scsi_unregister(struct Scsi_Host *shost) 465 { 466 list_del(&shost->sht_legacy_list); 467 scsi_host_put(shost); 468 } 469 EXPORT_SYMBOL(scsi_unregister); 470 471 static int __scsi_host_match(struct device *dev, const void *data) 472 { 473 struct Scsi_Host *p; 474 const unsigned short *hostnum = data; 475 476 p = class_to_shost(dev); 477 return p->host_no == *hostnum; 478 } 479 480 /** 481 * scsi_host_lookup - get a reference to a Scsi_Host by host no 482 * @hostnum: host number to locate 483 * 484 * Return value: 485 * A pointer to located Scsi_Host or NULL. 486 * 487 * The caller must do a scsi_host_put() to drop the reference 488 * that scsi_host_get() took. The put_device() below dropped 489 * the reference from class_find_device(). 490 **/ 491 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 492 { 493 struct device *cdev; 494 struct Scsi_Host *shost = NULL; 495 496 cdev = class_find_device(&shost_class, NULL, &hostnum, 497 __scsi_host_match); 498 if (cdev) { 499 shost = scsi_host_get(class_to_shost(cdev)); 500 put_device(cdev); 501 } 502 return shost; 503 } 504 EXPORT_SYMBOL(scsi_host_lookup); 505 506 /** 507 * scsi_host_get - inc a Scsi_Host ref count 508 * @shost: Pointer to Scsi_Host to inc. 509 **/ 510 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 511 { 512 if ((shost->shost_state == SHOST_DEL) || 513 !get_device(&shost->shost_gendev)) 514 return NULL; 515 return shost; 516 } 517 EXPORT_SYMBOL(scsi_host_get); 518 519 /** 520 * scsi_host_put - dec a Scsi_Host ref count 521 * @shost: Pointer to Scsi_Host to dec. 522 **/ 523 void scsi_host_put(struct Scsi_Host *shost) 524 { 525 put_device(&shost->shost_gendev); 526 } 527 EXPORT_SYMBOL(scsi_host_put); 528 529 int scsi_init_hosts(void) 530 { 531 return class_register(&shost_class); 532 } 533 534 void scsi_exit_hosts(void) 535 { 536 class_unregister(&shost_class); 537 } 538 539 int scsi_is_host_device(const struct device *dev) 540 { 541 return dev->type == &scsi_host_type; 542 } 543 EXPORT_SYMBOL(scsi_is_host_device); 544 545 /** 546 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 547 * @shost: Pointer to Scsi_Host. 548 * @work: Work to queue for execution. 549 * 550 * Return value: 551 * 1 - work queued for execution 552 * 0 - work is already queued 553 * -EINVAL - work queue doesn't exist 554 **/ 555 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 556 { 557 if (unlikely(!shost->work_q)) { 558 printk(KERN_ERR 559 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 560 "when no workqueue created.\n", shost->hostt->name); 561 dump_stack(); 562 563 return -EINVAL; 564 } 565 566 return queue_work(shost->work_q, work); 567 } 568 EXPORT_SYMBOL_GPL(scsi_queue_work); 569 570 /** 571 * scsi_flush_work - Flush a Scsi_Host's workqueue. 572 * @shost: Pointer to Scsi_Host. 573 **/ 574 void scsi_flush_work(struct Scsi_Host *shost) 575 { 576 if (!shost->work_q) { 577 printk(KERN_ERR 578 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 579 "when no workqueue created.\n", shost->hostt->name); 580 dump_stack(); 581 return; 582 } 583 584 flush_workqueue(shost->work_q); 585 } 586 EXPORT_SYMBOL_GPL(scsi_flush_work); 587