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 36 #include <scsi/scsi_device.h> 37 #include <scsi/scsi_host.h> 38 #include <scsi/scsi_transport.h> 39 40 #include "scsi_priv.h" 41 #include "scsi_logging.h" 42 43 44 static atomic_t scsi_host_next_hn; /* host_no for next new host */ 45 46 47 static void scsi_host_cls_release(struct device *dev) 48 { 49 put_device(&class_to_shost(dev)->shost_gendev); 50 } 51 52 static struct class shost_class = { 53 .name = "scsi_host", 54 .dev_release = scsi_host_cls_release, 55 }; 56 57 /** 58 * scsi_host_set_state - Take the given host through the host state model. 59 * @shost: scsi host to change the state of. 60 * @state: state to change to. 61 * 62 * Returns zero if unsuccessful or an error if the requested 63 * transition is illegal. 64 **/ 65 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) 66 { 67 enum scsi_host_state oldstate = shost->shost_state; 68 69 if (state == oldstate) 70 return 0; 71 72 switch (state) { 73 case SHOST_CREATED: 74 /* There are no legal states that come back to 75 * created. This is the manually initialised start 76 * state */ 77 goto illegal; 78 79 case SHOST_RUNNING: 80 switch (oldstate) { 81 case SHOST_CREATED: 82 case SHOST_RECOVERY: 83 break; 84 default: 85 goto illegal; 86 } 87 break; 88 89 case SHOST_RECOVERY: 90 switch (oldstate) { 91 case SHOST_RUNNING: 92 break; 93 default: 94 goto illegal; 95 } 96 break; 97 98 case SHOST_CANCEL: 99 switch (oldstate) { 100 case SHOST_CREATED: 101 case SHOST_RUNNING: 102 case SHOST_CANCEL_RECOVERY: 103 break; 104 default: 105 goto illegal; 106 } 107 break; 108 109 case SHOST_DEL: 110 switch (oldstate) { 111 case SHOST_CANCEL: 112 case SHOST_DEL_RECOVERY: 113 break; 114 default: 115 goto illegal; 116 } 117 break; 118 119 case SHOST_CANCEL_RECOVERY: 120 switch (oldstate) { 121 case SHOST_CANCEL: 122 case SHOST_RECOVERY: 123 break; 124 default: 125 goto illegal; 126 } 127 break; 128 129 case SHOST_DEL_RECOVERY: 130 switch (oldstate) { 131 case SHOST_CANCEL_RECOVERY: 132 break; 133 default: 134 goto illegal; 135 } 136 break; 137 } 138 shost->shost_state = state; 139 return 0; 140 141 illegal: 142 SCSI_LOG_ERROR_RECOVERY(1, 143 shost_printk(KERN_ERR, shost, 144 "Illegal host state transition" 145 "%s->%s\n", 146 scsi_host_state_name(oldstate), 147 scsi_host_state_name(state))); 148 return -EINVAL; 149 } 150 EXPORT_SYMBOL(scsi_host_set_state); 151 152 /** 153 * scsi_remove_host - remove a scsi host 154 * @shost: a pointer to a scsi host to remove 155 **/ 156 void scsi_remove_host(struct Scsi_Host *shost) 157 { 158 unsigned long flags; 159 mutex_lock(&shost->scan_mutex); 160 spin_lock_irqsave(shost->host_lock, flags); 161 if (scsi_host_set_state(shost, SHOST_CANCEL)) 162 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { 163 spin_unlock_irqrestore(shost->host_lock, flags); 164 mutex_unlock(&shost->scan_mutex); 165 return; 166 } 167 spin_unlock_irqrestore(shost->host_lock, flags); 168 scsi_forget_host(shost); 169 mutex_unlock(&shost->scan_mutex); 170 scsi_proc_host_rm(shost); 171 172 spin_lock_irqsave(shost->host_lock, flags); 173 if (scsi_host_set_state(shost, SHOST_DEL)) 174 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); 175 spin_unlock_irqrestore(shost->host_lock, flags); 176 177 transport_unregister_device(&shost->shost_gendev); 178 device_unregister(&shost->shost_dev); 179 device_del(&shost->shost_gendev); 180 } 181 EXPORT_SYMBOL(scsi_remove_host); 182 183 /** 184 * scsi_add_host_with_dma - add a scsi host with dma device 185 * @shost: scsi host pointer to add 186 * @dev: a struct device of type scsi class 187 * @dma_dev: dma device for the host 188 * 189 * Note: You rarely need to worry about this unless you're in a 190 * virtualised host environments, so use the simpler scsi_add_host() 191 * function instead. 192 * 193 * Return value: 194 * 0 on success / != 0 for error 195 **/ 196 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, 197 struct device *dma_dev) 198 { 199 struct scsi_host_template *sht = shost->hostt; 200 int error = -EINVAL; 201 202 printk(KERN_INFO "scsi%d : %s\n", shost->host_no, 203 sht->info ? sht->info(shost) : sht->name); 204 205 if (!shost->can_queue) { 206 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", 207 sht->name); 208 goto fail; 209 } 210 211 error = scsi_setup_command_freelist(shost); 212 if (error) 213 goto fail; 214 215 if (!shost->shost_gendev.parent) 216 shost->shost_gendev.parent = dev ? dev : &platform_bus; 217 shost->dma_dev = dma_dev; 218 219 device_enable_async_suspend(&shost->shost_gendev); 220 221 error = device_add(&shost->shost_gendev); 222 if (error) 223 goto out; 224 225 scsi_host_set_state(shost, SHOST_RUNNING); 226 get_device(shost->shost_gendev.parent); 227 228 device_enable_async_suspend(&shost->shost_dev); 229 230 error = device_add(&shost->shost_dev); 231 if (error) 232 goto out_del_gendev; 233 234 get_device(&shost->shost_gendev); 235 236 if (shost->transportt->host_size) { 237 shost->shost_data = kzalloc(shost->transportt->host_size, 238 GFP_KERNEL); 239 if (shost->shost_data == NULL) { 240 error = -ENOMEM; 241 goto out_del_dev; 242 } 243 } 244 245 if (shost->transportt->create_work_queue) { 246 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 247 "scsi_wq_%d", shost->host_no); 248 shost->work_q = create_singlethread_workqueue( 249 shost->work_q_name); 250 if (!shost->work_q) { 251 error = -EINVAL; 252 goto out_free_shost_data; 253 } 254 } 255 256 error = scsi_sysfs_add_host(shost); 257 if (error) 258 goto out_destroy_host; 259 260 scsi_proc_host_add(shost); 261 return error; 262 263 out_destroy_host: 264 if (shost->work_q) 265 destroy_workqueue(shost->work_q); 266 out_free_shost_data: 267 kfree(shost->shost_data); 268 out_del_dev: 269 device_del(&shost->shost_dev); 270 out_del_gendev: 271 device_del(&shost->shost_gendev); 272 out: 273 scsi_destroy_command_freelist(shost); 274 fail: 275 return error; 276 } 277 EXPORT_SYMBOL(scsi_add_host_with_dma); 278 279 static void scsi_host_dev_release(struct device *dev) 280 { 281 struct Scsi_Host *shost = dev_to_shost(dev); 282 struct device *parent = dev->parent; 283 284 scsi_proc_hostdir_rm(shost->hostt); 285 286 if (shost->ehandler) 287 kthread_stop(shost->ehandler); 288 if (shost->work_q) 289 destroy_workqueue(shost->work_q); 290 if (shost->uspace_req_q) { 291 kfree(shost->uspace_req_q->queuedata); 292 scsi_free_queue(shost->uspace_req_q); 293 } 294 295 scsi_destroy_command_freelist(shost); 296 if (shost->bqt) 297 blk_free_tags(shost->bqt); 298 299 kfree(shost->shost_data); 300 301 if (parent) 302 put_device(parent); 303 kfree(shost); 304 } 305 306 static struct device_type scsi_host_type = { 307 .name = "scsi_host", 308 .release = scsi_host_dev_release, 309 }; 310 311 /** 312 * scsi_host_alloc - register a scsi host adapter instance. 313 * @sht: pointer to scsi host template 314 * @privsize: extra bytes to allocate for driver 315 * 316 * Note: 317 * Allocate a new Scsi_Host and perform basic initialization. 318 * The host is not published to the scsi midlayer until scsi_add_host 319 * is called. 320 * 321 * Return value: 322 * Pointer to a new Scsi_Host 323 **/ 324 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 325 { 326 struct Scsi_Host *shost; 327 gfp_t gfp_mask = GFP_KERNEL; 328 int rval; 329 330 if (sht->unchecked_isa_dma && privsize) 331 gfp_mask |= __GFP_DMA; 332 333 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 334 if (!shost) 335 return NULL; 336 337 shost->host_lock = &shost->default_lock; 338 spin_lock_init(shost->host_lock); 339 shost->shost_state = SHOST_CREATED; 340 INIT_LIST_HEAD(&shost->__devices); 341 INIT_LIST_HEAD(&shost->__targets); 342 INIT_LIST_HEAD(&shost->eh_cmd_q); 343 INIT_LIST_HEAD(&shost->starved_list); 344 init_waitqueue_head(&shost->host_wait); 345 346 mutex_init(&shost->scan_mutex); 347 348 /* 349 * subtract one because we increment first then return, but we need to 350 * know what the next host number was before increment 351 */ 352 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; 353 shost->dma_channel = 0xff; 354 355 /* These three are default values which can be overridden */ 356 shost->max_channel = 0; 357 shost->max_id = 8; 358 shost->max_lun = 8; 359 360 /* Give each shost a default transportt */ 361 shost->transportt = &blank_transport_template; 362 363 /* 364 * All drivers right now should be able to handle 12 byte 365 * commands. Every so often there are requests for 16 byte 366 * commands, but individual low-level drivers need to certify that 367 * they actually do something sensible with such commands. 368 */ 369 shost->max_cmd_len = 12; 370 shost->hostt = sht; 371 shost->this_id = sht->this_id; 372 shost->can_queue = sht->can_queue; 373 shost->sg_tablesize = sht->sg_tablesize; 374 shost->cmd_per_lun = sht->cmd_per_lun; 375 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 376 shost->use_clustering = sht->use_clustering; 377 shost->ordered_tag = sht->ordered_tag; 378 379 if (sht->supported_mode == MODE_UNKNOWN) 380 /* means we didn't set it ... default to INITIATOR */ 381 shost->active_mode = MODE_INITIATOR; 382 else 383 shost->active_mode = sht->supported_mode; 384 385 if (sht->max_host_blocked) 386 shost->max_host_blocked = sht->max_host_blocked; 387 else 388 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 389 390 /* 391 * If the driver imposes no hard sector transfer limit, start at 392 * machine infinity initially. 393 */ 394 if (sht->max_sectors) 395 shost->max_sectors = sht->max_sectors; 396 else 397 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 398 399 /* 400 * assume a 4GB boundary, if not set 401 */ 402 if (sht->dma_boundary) 403 shost->dma_boundary = sht->dma_boundary; 404 else 405 shost->dma_boundary = 0xffffffff; 406 407 device_initialize(&shost->shost_gendev); 408 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 409 #ifndef CONFIG_SYSFS_DEPRECATED 410 shost->shost_gendev.bus = &scsi_bus_type; 411 #endif 412 shost->shost_gendev.type = &scsi_host_type; 413 414 device_initialize(&shost->shost_dev); 415 shost->shost_dev.parent = &shost->shost_gendev; 416 shost->shost_dev.class = &shost_class; 417 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 418 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 419 420 shost->ehandler = kthread_run(scsi_error_handler, shost, 421 "scsi_eh_%d", shost->host_no); 422 if (IS_ERR(shost->ehandler)) { 423 rval = PTR_ERR(shost->ehandler); 424 goto fail_kfree; 425 } 426 427 scsi_proc_hostdir_add(shost->hostt); 428 return shost; 429 430 fail_kfree: 431 kfree(shost); 432 return NULL; 433 } 434 EXPORT_SYMBOL(scsi_host_alloc); 435 436 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 437 { 438 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 439 440 if (!sht->detect) { 441 printk(KERN_WARNING "scsi_register() called on new-style " 442 "template for driver %s\n", sht->name); 443 dump_stack(); 444 } 445 446 if (shost) 447 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 448 return shost; 449 } 450 EXPORT_SYMBOL(scsi_register); 451 452 void scsi_unregister(struct Scsi_Host *shost) 453 { 454 list_del(&shost->sht_legacy_list); 455 scsi_host_put(shost); 456 } 457 EXPORT_SYMBOL(scsi_unregister); 458 459 static int __scsi_host_match(struct device *dev, void *data) 460 { 461 struct Scsi_Host *p; 462 unsigned short *hostnum = (unsigned short *)data; 463 464 p = class_to_shost(dev); 465 return p->host_no == *hostnum; 466 } 467 468 /** 469 * scsi_host_lookup - get a reference to a Scsi_Host by host no 470 * @hostnum: host number to locate 471 * 472 * Return value: 473 * A pointer to located Scsi_Host or NULL. 474 * 475 * The caller must do a scsi_host_put() to drop the reference 476 * that scsi_host_get() took. The put_device() below dropped 477 * the reference from class_find_device(). 478 **/ 479 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 480 { 481 struct device *cdev; 482 struct Scsi_Host *shost = NULL; 483 484 cdev = class_find_device(&shost_class, NULL, &hostnum, 485 __scsi_host_match); 486 if (cdev) { 487 shost = scsi_host_get(class_to_shost(cdev)); 488 put_device(cdev); 489 } 490 return shost; 491 } 492 EXPORT_SYMBOL(scsi_host_lookup); 493 494 /** 495 * scsi_host_get - inc a Scsi_Host ref count 496 * @shost: Pointer to Scsi_Host to inc. 497 **/ 498 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 499 { 500 if ((shost->shost_state == SHOST_DEL) || 501 !get_device(&shost->shost_gendev)) 502 return NULL; 503 return shost; 504 } 505 EXPORT_SYMBOL(scsi_host_get); 506 507 /** 508 * scsi_host_put - dec a Scsi_Host ref count 509 * @shost: Pointer to Scsi_Host to dec. 510 **/ 511 void scsi_host_put(struct Scsi_Host *shost) 512 { 513 put_device(&shost->shost_gendev); 514 } 515 EXPORT_SYMBOL(scsi_host_put); 516 517 int scsi_init_hosts(void) 518 { 519 return class_register(&shost_class); 520 } 521 522 void scsi_exit_hosts(void) 523 { 524 class_unregister(&shost_class); 525 } 526 527 int scsi_is_host_device(const struct device *dev) 528 { 529 return dev->type == &scsi_host_type; 530 } 531 EXPORT_SYMBOL(scsi_is_host_device); 532 533 /** 534 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 535 * @shost: Pointer to Scsi_Host. 536 * @work: Work to queue for execution. 537 * 538 * Return value: 539 * 1 - work queued for execution 540 * 0 - work is already queued 541 * -EINVAL - work queue doesn't exist 542 **/ 543 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 544 { 545 if (unlikely(!shost->work_q)) { 546 printk(KERN_ERR 547 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 548 "when no workqueue created.\n", shost->hostt->name); 549 dump_stack(); 550 551 return -EINVAL; 552 } 553 554 return queue_work(shost->work_q, work); 555 } 556 EXPORT_SYMBOL_GPL(scsi_queue_work); 557 558 /** 559 * scsi_flush_work - Flush a Scsi_Host's workqueue. 560 * @shost: Pointer to Scsi_Host. 561 **/ 562 void scsi_flush_work(struct Scsi_Host *shost) 563 { 564 if (!shost->work_q) { 565 printk(KERN_ERR 566 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 567 "when no workqueue created.\n", shost->hostt->name); 568 dump_stack(); 569 return; 570 } 571 572 flush_workqueue(shost->work_q); 573 } 574 EXPORT_SYMBOL_GPL(scsi_flush_work); 575