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/kthread.h> 28 #include <linux/string.h> 29 #include <linux/mm.h> 30 #include <linux/init.h> 31 #include <linux/completion.h> 32 #include <linux/transport_class.h> 33 #include <linux/platform_device.h> 34 35 #include <scsi/scsi_device.h> 36 #include <scsi/scsi_host.h> 37 #include <scsi/scsi_transport.h> 38 39 #include "scsi_priv.h" 40 #include "scsi_logging.h" 41 42 43 static int scsi_host_next_hn; /* host_no for next new host */ 44 45 46 static void scsi_host_cls_release(struct device *dev) 47 { 48 put_device(&class_to_shost(dev)->shost_gendev); 49 } 50 51 static struct class shost_class = { 52 .name = "scsi_host", 53 .dev_release = scsi_host_cls_release, 54 }; 55 56 /** 57 * scsi_host_set_state - Take the given host through the host state model. 58 * @shost: scsi host to change the state of. 59 * @state: state to change to. 60 * 61 * Returns zero if unsuccessful or an error if the requested 62 * transition is illegal. 63 **/ 64 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) 65 { 66 enum scsi_host_state oldstate = shost->shost_state; 67 68 if (state == oldstate) 69 return 0; 70 71 switch (state) { 72 case SHOST_CREATED: 73 /* There are no legal states that come back to 74 * created. This is the manually initialised start 75 * state */ 76 goto illegal; 77 78 case SHOST_RUNNING: 79 switch (oldstate) { 80 case SHOST_CREATED: 81 case SHOST_RECOVERY: 82 break; 83 default: 84 goto illegal; 85 } 86 break; 87 88 case SHOST_RECOVERY: 89 switch (oldstate) { 90 case SHOST_RUNNING: 91 break; 92 default: 93 goto illegal; 94 } 95 break; 96 97 case SHOST_CANCEL: 98 switch (oldstate) { 99 case SHOST_CREATED: 100 case SHOST_RUNNING: 101 case SHOST_CANCEL_RECOVERY: 102 break; 103 default: 104 goto illegal; 105 } 106 break; 107 108 case SHOST_DEL: 109 switch (oldstate) { 110 case SHOST_CANCEL: 111 case SHOST_DEL_RECOVERY: 112 break; 113 default: 114 goto illegal; 115 } 116 break; 117 118 case SHOST_CANCEL_RECOVERY: 119 switch (oldstate) { 120 case SHOST_CANCEL: 121 case SHOST_RECOVERY: 122 break; 123 default: 124 goto illegal; 125 } 126 break; 127 128 case SHOST_DEL_RECOVERY: 129 switch (oldstate) { 130 case SHOST_CANCEL_RECOVERY: 131 break; 132 default: 133 goto illegal; 134 } 135 break; 136 } 137 shost->shost_state = state; 138 return 0; 139 140 illegal: 141 SCSI_LOG_ERROR_RECOVERY(1, 142 shost_printk(KERN_ERR, shost, 143 "Illegal host state transition" 144 "%s->%s\n", 145 scsi_host_state_name(oldstate), 146 scsi_host_state_name(state))); 147 return -EINVAL; 148 } 149 EXPORT_SYMBOL(scsi_host_set_state); 150 151 /** 152 * scsi_remove_host - remove a scsi host 153 * @shost: a pointer to a scsi host to remove 154 **/ 155 void scsi_remove_host(struct Scsi_Host *shost) 156 { 157 unsigned long flags; 158 mutex_lock(&shost->scan_mutex); 159 spin_lock_irqsave(shost->host_lock, flags); 160 if (scsi_host_set_state(shost, SHOST_CANCEL)) 161 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { 162 spin_unlock_irqrestore(shost->host_lock, flags); 163 mutex_unlock(&shost->scan_mutex); 164 return; 165 } 166 spin_unlock_irqrestore(shost->host_lock, flags); 167 mutex_unlock(&shost->scan_mutex); 168 scsi_forget_host(shost); 169 scsi_proc_host_rm(shost); 170 171 spin_lock_irqsave(shost->host_lock, flags); 172 if (scsi_host_set_state(shost, SHOST_DEL)) 173 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); 174 spin_unlock_irqrestore(shost->host_lock, flags); 175 176 transport_unregister_device(&shost->shost_gendev); 177 device_unregister(&shost->shost_dev); 178 device_del(&shost->shost_gendev); 179 scsi_proc_hostdir_rm(shost->hostt); 180 } 181 EXPORT_SYMBOL(scsi_remove_host); 182 183 /** 184 * scsi_add_host - add a scsi host 185 * @shost: scsi host pointer to add 186 * @dev: a struct device of type scsi class 187 * 188 * Return value: 189 * 0 on success / != 0 for error 190 **/ 191 int scsi_add_host(struct Scsi_Host *shost, struct device *dev) 192 { 193 struct scsi_host_template *sht = shost->hostt; 194 int error = -EINVAL; 195 196 printk(KERN_INFO "scsi%d : %s\n", shost->host_no, 197 sht->info ? sht->info(shost) : sht->name); 198 199 if (!shost->can_queue) { 200 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", 201 sht->name); 202 goto fail; 203 } 204 205 error = scsi_setup_command_freelist(shost); 206 if (error) 207 goto fail; 208 209 if (!shost->shost_gendev.parent) 210 shost->shost_gendev.parent = dev ? dev : &platform_bus; 211 212 error = device_add(&shost->shost_gendev); 213 if (error) 214 goto out; 215 216 scsi_host_set_state(shost, SHOST_RUNNING); 217 get_device(shost->shost_gendev.parent); 218 219 error = device_add(&shost->shost_dev); 220 if (error) 221 goto out_del_gendev; 222 223 get_device(&shost->shost_gendev); 224 225 if (shost->transportt->host_size) { 226 shost->shost_data = kzalloc(shost->transportt->host_size, 227 GFP_KERNEL); 228 if (shost->shost_data == NULL) { 229 error = -ENOMEM; 230 goto out_del_dev; 231 } 232 } 233 234 if (shost->transportt->create_work_queue) { 235 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 236 "scsi_wq_%d", shost->host_no); 237 shost->work_q = create_singlethread_workqueue( 238 shost->work_q_name); 239 if (!shost->work_q) { 240 error = -EINVAL; 241 goto out_free_shost_data; 242 } 243 } 244 245 error = scsi_sysfs_add_host(shost); 246 if (error) 247 goto out_destroy_host; 248 249 scsi_proc_host_add(shost); 250 return error; 251 252 out_destroy_host: 253 if (shost->work_q) 254 destroy_workqueue(shost->work_q); 255 out_free_shost_data: 256 kfree(shost->shost_data); 257 out_del_dev: 258 device_del(&shost->shost_dev); 259 out_del_gendev: 260 device_del(&shost->shost_gendev); 261 out: 262 scsi_destroy_command_freelist(shost); 263 fail: 264 return error; 265 } 266 EXPORT_SYMBOL(scsi_add_host); 267 268 static void scsi_host_dev_release(struct device *dev) 269 { 270 struct Scsi_Host *shost = dev_to_shost(dev); 271 struct device *parent = dev->parent; 272 273 if (shost->ehandler) 274 kthread_stop(shost->ehandler); 275 if (shost->work_q) 276 destroy_workqueue(shost->work_q); 277 if (shost->uspace_req_q) { 278 kfree(shost->uspace_req_q->queuedata); 279 scsi_free_queue(shost->uspace_req_q); 280 } 281 282 scsi_destroy_command_freelist(shost); 283 if (shost->bqt) 284 blk_free_tags(shost->bqt); 285 286 kfree(shost->shost_data); 287 288 if (parent) 289 put_device(parent); 290 kfree(shost); 291 } 292 293 static struct device_type scsi_host_type = { 294 .name = "scsi_host", 295 .release = scsi_host_dev_release, 296 }; 297 298 /** 299 * scsi_host_alloc - register a scsi host adapter instance. 300 * @sht: pointer to scsi host template 301 * @privsize: extra bytes to allocate for driver 302 * 303 * Note: 304 * Allocate a new Scsi_Host and perform basic initialization. 305 * The host is not published to the scsi midlayer until scsi_add_host 306 * is called. 307 * 308 * Return value: 309 * Pointer to a new Scsi_Host 310 **/ 311 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 312 { 313 struct Scsi_Host *shost; 314 gfp_t gfp_mask = GFP_KERNEL; 315 int rval; 316 317 if (sht->unchecked_isa_dma && privsize) 318 gfp_mask |= __GFP_DMA; 319 320 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 321 if (!shost) 322 return NULL; 323 324 shost->host_lock = &shost->default_lock; 325 spin_lock_init(shost->host_lock); 326 shost->shost_state = SHOST_CREATED; 327 INIT_LIST_HEAD(&shost->__devices); 328 INIT_LIST_HEAD(&shost->__targets); 329 INIT_LIST_HEAD(&shost->eh_cmd_q); 330 INIT_LIST_HEAD(&shost->starved_list); 331 init_waitqueue_head(&shost->host_wait); 332 333 mutex_init(&shost->scan_mutex); 334 335 shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ 336 shost->dma_channel = 0xff; 337 338 /* These three are default values which can be overridden */ 339 shost->max_channel = 0; 340 shost->max_id = 8; 341 shost->max_lun = 8; 342 343 /* Give each shost a default transportt */ 344 shost->transportt = &blank_transport_template; 345 346 /* 347 * All drivers right now should be able to handle 12 byte 348 * commands. Every so often there are requests for 16 byte 349 * commands, but individual low-level drivers need to certify that 350 * they actually do something sensible with such commands. 351 */ 352 shost->max_cmd_len = 12; 353 shost->hostt = sht; 354 shost->this_id = sht->this_id; 355 shost->can_queue = sht->can_queue; 356 shost->sg_tablesize = sht->sg_tablesize; 357 shost->cmd_per_lun = sht->cmd_per_lun; 358 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 359 shost->use_clustering = sht->use_clustering; 360 shost->ordered_tag = sht->ordered_tag; 361 362 if (sht->supported_mode == MODE_UNKNOWN) 363 /* means we didn't set it ... default to INITIATOR */ 364 shost->active_mode = MODE_INITIATOR; 365 else 366 shost->active_mode = sht->supported_mode; 367 368 if (sht->max_host_blocked) 369 shost->max_host_blocked = sht->max_host_blocked; 370 else 371 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 372 373 /* 374 * If the driver imposes no hard sector transfer limit, start at 375 * machine infinity initially. 376 */ 377 if (sht->max_sectors) 378 shost->max_sectors = sht->max_sectors; 379 else 380 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 381 382 /* 383 * assume a 4GB boundary, if not set 384 */ 385 if (sht->dma_boundary) 386 shost->dma_boundary = sht->dma_boundary; 387 else 388 shost->dma_boundary = 0xffffffff; 389 390 device_initialize(&shost->shost_gendev); 391 snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", 392 shost->host_no); 393 #ifndef CONFIG_SYSFS_DEPRECATED 394 shost->shost_gendev.bus = &scsi_bus_type; 395 #endif 396 shost->shost_gendev.type = &scsi_host_type; 397 398 device_initialize(&shost->shost_dev); 399 shost->shost_dev.parent = &shost->shost_gendev; 400 shost->shost_dev.class = &shost_class; 401 snprintf(shost->shost_dev.bus_id, BUS_ID_SIZE, "host%d", 402 shost->host_no); 403 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 404 405 shost->ehandler = kthread_run(scsi_error_handler, shost, 406 "scsi_eh_%d", shost->host_no); 407 if (IS_ERR(shost->ehandler)) { 408 rval = PTR_ERR(shost->ehandler); 409 goto fail_kfree; 410 } 411 412 scsi_proc_hostdir_add(shost->hostt); 413 return shost; 414 415 fail_kfree: 416 kfree(shost); 417 return NULL; 418 } 419 EXPORT_SYMBOL(scsi_host_alloc); 420 421 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 422 { 423 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 424 425 if (!sht->detect) { 426 printk(KERN_WARNING "scsi_register() called on new-style " 427 "template for driver %s\n", sht->name); 428 dump_stack(); 429 } 430 431 if (shost) 432 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 433 return shost; 434 } 435 EXPORT_SYMBOL(scsi_register); 436 437 void scsi_unregister(struct Scsi_Host *shost) 438 { 439 list_del(&shost->sht_legacy_list); 440 scsi_host_put(shost); 441 } 442 EXPORT_SYMBOL(scsi_unregister); 443 444 static int __scsi_host_match(struct device *dev, void *data) 445 { 446 struct Scsi_Host *p; 447 unsigned short *hostnum = (unsigned short *)data; 448 449 p = class_to_shost(dev); 450 return p->host_no == *hostnum; 451 } 452 453 /** 454 * scsi_host_lookup - get a reference to a Scsi_Host by host no 455 * @hostnum: host number to locate 456 * 457 * Return value: 458 * A pointer to located Scsi_Host or NULL. 459 * 460 * The caller must do a scsi_host_put() to drop the reference 461 * that scsi_host_get() took. The put_device() below dropped 462 * the reference from class_find_device(). 463 **/ 464 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 465 { 466 struct device *cdev; 467 struct Scsi_Host *shost = ERR_PTR(-ENXIO); 468 469 cdev = class_find_device(&shost_class, NULL, &hostnum, 470 __scsi_host_match); 471 if (cdev) { 472 shost = scsi_host_get(class_to_shost(cdev)); 473 put_device(cdev); 474 } 475 return shost; 476 } 477 EXPORT_SYMBOL(scsi_host_lookup); 478 479 /** 480 * scsi_host_get - inc a Scsi_Host ref count 481 * @shost: Pointer to Scsi_Host to inc. 482 **/ 483 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 484 { 485 if ((shost->shost_state == SHOST_DEL) || 486 !get_device(&shost->shost_gendev)) 487 return NULL; 488 return shost; 489 } 490 EXPORT_SYMBOL(scsi_host_get); 491 492 /** 493 * scsi_host_put - dec a Scsi_Host ref count 494 * @shost: Pointer to Scsi_Host to dec. 495 **/ 496 void scsi_host_put(struct Scsi_Host *shost) 497 { 498 put_device(&shost->shost_gendev); 499 } 500 EXPORT_SYMBOL(scsi_host_put); 501 502 int scsi_init_hosts(void) 503 { 504 return class_register(&shost_class); 505 } 506 507 void scsi_exit_hosts(void) 508 { 509 class_unregister(&shost_class); 510 } 511 512 int scsi_is_host_device(const struct device *dev) 513 { 514 return dev->type == &scsi_host_type; 515 } 516 EXPORT_SYMBOL(scsi_is_host_device); 517 518 /** 519 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 520 * @shost: Pointer to Scsi_Host. 521 * @work: Work to queue for execution. 522 * 523 * Return value: 524 * 1 - work queued for execution 525 * 0 - work is already queued 526 * -EINVAL - work queue doesn't exist 527 **/ 528 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 529 { 530 if (unlikely(!shost->work_q)) { 531 printk(KERN_ERR 532 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 533 "when no workqueue created.\n", shost->hostt->name); 534 dump_stack(); 535 536 return -EINVAL; 537 } 538 539 return queue_work(shost->work_q, work); 540 } 541 EXPORT_SYMBOL_GPL(scsi_queue_work); 542 543 /** 544 * scsi_flush_work - Flush a Scsi_Host's workqueue. 545 * @shost: Pointer to Scsi_Host. 546 **/ 547 void scsi_flush_work(struct Scsi_Host *shost) 548 { 549 if (!shost->work_q) { 550 printk(KERN_ERR 551 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 552 "when no workqueue created.\n", shost->hostt->name); 553 dump_stack(); 554 return; 555 } 556 557 flush_workqueue(shost->work_q); 558 } 559 EXPORT_SYMBOL_GPL(scsi_flush_work); 560