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 atomic_t 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 scsi_forget_host(shost); 168 mutex_unlock(&shost->scan_mutex); 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 } 180 EXPORT_SYMBOL(scsi_remove_host); 181 182 /** 183 * scsi_add_host_with_dma - add a scsi host with dma device 184 * @shost: scsi host pointer to add 185 * @dev: a struct device of type scsi class 186 * @dma_dev: dma device for the host 187 * 188 * Note: You rarely need to worry about this unless you're in a 189 * virtualised host environments, so use the simpler scsi_add_host() 190 * function instead. 191 * 192 * Return value: 193 * 0 on success / != 0 for error 194 **/ 195 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, 196 struct device *dma_dev) 197 { 198 struct scsi_host_template *sht = shost->hostt; 199 int error = -EINVAL; 200 201 printk(KERN_INFO "scsi%d : %s\n", shost->host_no, 202 sht->info ? sht->info(shost) : sht->name); 203 204 if (!shost->can_queue) { 205 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", 206 sht->name); 207 goto fail; 208 } 209 210 error = scsi_setup_command_freelist(shost); 211 if (error) 212 goto fail; 213 214 if (!shost->shost_gendev.parent) 215 shost->shost_gendev.parent = dev ? dev : &platform_bus; 216 shost->dma_dev = dma_dev; 217 218 error = device_add(&shost->shost_gendev); 219 if (error) 220 goto out; 221 222 scsi_host_set_state(shost, SHOST_RUNNING); 223 get_device(shost->shost_gendev.parent); 224 225 error = device_add(&shost->shost_dev); 226 if (error) 227 goto out_del_gendev; 228 229 get_device(&shost->shost_gendev); 230 231 if (shost->transportt->host_size) { 232 shost->shost_data = kzalloc(shost->transportt->host_size, 233 GFP_KERNEL); 234 if (shost->shost_data == NULL) { 235 error = -ENOMEM; 236 goto out_del_dev; 237 } 238 } 239 240 if (shost->transportt->create_work_queue) { 241 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 242 "scsi_wq_%d", shost->host_no); 243 shost->work_q = create_singlethread_workqueue( 244 shost->work_q_name); 245 if (!shost->work_q) { 246 error = -EINVAL; 247 goto out_free_shost_data; 248 } 249 } 250 251 error = scsi_sysfs_add_host(shost); 252 if (error) 253 goto out_destroy_host; 254 255 scsi_proc_host_add(shost); 256 return error; 257 258 out_destroy_host: 259 if (shost->work_q) 260 destroy_workqueue(shost->work_q); 261 out_free_shost_data: 262 kfree(shost->shost_data); 263 out_del_dev: 264 device_del(&shost->shost_dev); 265 out_del_gendev: 266 device_del(&shost->shost_gendev); 267 out: 268 scsi_destroy_command_freelist(shost); 269 fail: 270 return error; 271 } 272 EXPORT_SYMBOL(scsi_add_host_with_dma); 273 274 static void scsi_host_dev_release(struct device *dev) 275 { 276 struct Scsi_Host *shost = dev_to_shost(dev); 277 struct device *parent = dev->parent; 278 279 scsi_proc_hostdir_rm(shost->hostt); 280 281 if (shost->ehandler) 282 kthread_stop(shost->ehandler); 283 if (shost->work_q) 284 destroy_workqueue(shost->work_q); 285 if (shost->uspace_req_q) { 286 kfree(shost->uspace_req_q->queuedata); 287 scsi_free_queue(shost->uspace_req_q); 288 } 289 290 scsi_destroy_command_freelist(shost); 291 if (shost->bqt) 292 blk_free_tags(shost->bqt); 293 294 kfree(shost->shost_data); 295 296 if (parent) 297 put_device(parent); 298 kfree(shost); 299 } 300 301 static struct device_type scsi_host_type = { 302 .name = "scsi_host", 303 .release = scsi_host_dev_release, 304 }; 305 306 /** 307 * scsi_host_alloc - register a scsi host adapter instance. 308 * @sht: pointer to scsi host template 309 * @privsize: extra bytes to allocate for driver 310 * 311 * Note: 312 * Allocate a new Scsi_Host and perform basic initialization. 313 * The host is not published to the scsi midlayer until scsi_add_host 314 * is called. 315 * 316 * Return value: 317 * Pointer to a new Scsi_Host 318 **/ 319 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 320 { 321 struct Scsi_Host *shost; 322 gfp_t gfp_mask = GFP_KERNEL; 323 int rval; 324 325 if (sht->unchecked_isa_dma && privsize) 326 gfp_mask |= __GFP_DMA; 327 328 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 329 if (!shost) 330 return NULL; 331 332 shost->host_lock = &shost->default_lock; 333 spin_lock_init(shost->host_lock); 334 shost->shost_state = SHOST_CREATED; 335 INIT_LIST_HEAD(&shost->__devices); 336 INIT_LIST_HEAD(&shost->__targets); 337 INIT_LIST_HEAD(&shost->eh_cmd_q); 338 INIT_LIST_HEAD(&shost->starved_list); 339 init_waitqueue_head(&shost->host_wait); 340 341 mutex_init(&shost->scan_mutex); 342 343 /* 344 * subtract one because we increment first then return, but we need to 345 * know what the next host number was before increment 346 */ 347 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; 348 shost->dma_channel = 0xff; 349 350 /* These three are default values which can be overridden */ 351 shost->max_channel = 0; 352 shost->max_id = 8; 353 shost->max_lun = 8; 354 355 /* Give each shost a default transportt */ 356 shost->transportt = &blank_transport_template; 357 358 /* 359 * All drivers right now should be able to handle 12 byte 360 * commands. Every so often there are requests for 16 byte 361 * commands, but individual low-level drivers need to certify that 362 * they actually do something sensible with such commands. 363 */ 364 shost->max_cmd_len = 12; 365 shost->hostt = sht; 366 shost->this_id = sht->this_id; 367 shost->can_queue = sht->can_queue; 368 shost->sg_tablesize = sht->sg_tablesize; 369 shost->cmd_per_lun = sht->cmd_per_lun; 370 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 371 shost->use_clustering = sht->use_clustering; 372 shost->ordered_tag = sht->ordered_tag; 373 374 if (sht->supported_mode == MODE_UNKNOWN) 375 /* means we didn't set it ... default to INITIATOR */ 376 shost->active_mode = MODE_INITIATOR; 377 else 378 shost->active_mode = sht->supported_mode; 379 380 if (sht->max_host_blocked) 381 shost->max_host_blocked = sht->max_host_blocked; 382 else 383 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 384 385 /* 386 * If the driver imposes no hard sector transfer limit, start at 387 * machine infinity initially. 388 */ 389 if (sht->max_sectors) 390 shost->max_sectors = sht->max_sectors; 391 else 392 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 393 394 /* 395 * assume a 4GB boundary, if not set 396 */ 397 if (sht->dma_boundary) 398 shost->dma_boundary = sht->dma_boundary; 399 else 400 shost->dma_boundary = 0xffffffff; 401 402 device_initialize(&shost->shost_gendev); 403 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 404 #ifndef CONFIG_SYSFS_DEPRECATED 405 shost->shost_gendev.bus = &scsi_bus_type; 406 #endif 407 shost->shost_gendev.type = &scsi_host_type; 408 409 device_initialize(&shost->shost_dev); 410 shost->shost_dev.parent = &shost->shost_gendev; 411 shost->shost_dev.class = &shost_class; 412 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 413 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 414 415 shost->ehandler = kthread_run(scsi_error_handler, shost, 416 "scsi_eh_%d", shost->host_no); 417 if (IS_ERR(shost->ehandler)) { 418 rval = PTR_ERR(shost->ehandler); 419 goto fail_kfree; 420 } 421 422 scsi_proc_hostdir_add(shost->hostt); 423 return shost; 424 425 fail_kfree: 426 kfree(shost); 427 return NULL; 428 } 429 EXPORT_SYMBOL(scsi_host_alloc); 430 431 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 432 { 433 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 434 435 if (!sht->detect) { 436 printk(KERN_WARNING "scsi_register() called on new-style " 437 "template for driver %s\n", sht->name); 438 dump_stack(); 439 } 440 441 if (shost) 442 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 443 return shost; 444 } 445 EXPORT_SYMBOL(scsi_register); 446 447 void scsi_unregister(struct Scsi_Host *shost) 448 { 449 list_del(&shost->sht_legacy_list); 450 scsi_host_put(shost); 451 } 452 EXPORT_SYMBOL(scsi_unregister); 453 454 static int __scsi_host_match(struct device *dev, void *data) 455 { 456 struct Scsi_Host *p; 457 unsigned short *hostnum = (unsigned short *)data; 458 459 p = class_to_shost(dev); 460 return p->host_no == *hostnum; 461 } 462 463 /** 464 * scsi_host_lookup - get a reference to a Scsi_Host by host no 465 * @hostnum: host number to locate 466 * 467 * Return value: 468 * A pointer to located Scsi_Host or NULL. 469 * 470 * The caller must do a scsi_host_put() to drop the reference 471 * that scsi_host_get() took. The put_device() below dropped 472 * the reference from class_find_device(). 473 **/ 474 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 475 { 476 struct device *cdev; 477 struct Scsi_Host *shost = NULL; 478 479 cdev = class_find_device(&shost_class, NULL, &hostnum, 480 __scsi_host_match); 481 if (cdev) { 482 shost = scsi_host_get(class_to_shost(cdev)); 483 put_device(cdev); 484 } 485 return shost; 486 } 487 EXPORT_SYMBOL(scsi_host_lookup); 488 489 /** 490 * scsi_host_get - inc a Scsi_Host ref count 491 * @shost: Pointer to Scsi_Host to inc. 492 **/ 493 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 494 { 495 if ((shost->shost_state == SHOST_DEL) || 496 !get_device(&shost->shost_gendev)) 497 return NULL; 498 return shost; 499 } 500 EXPORT_SYMBOL(scsi_host_get); 501 502 /** 503 * scsi_host_put - dec a Scsi_Host ref count 504 * @shost: Pointer to Scsi_Host to dec. 505 **/ 506 void scsi_host_put(struct Scsi_Host *shost) 507 { 508 put_device(&shost->shost_gendev); 509 } 510 EXPORT_SYMBOL(scsi_host_put); 511 512 int scsi_init_hosts(void) 513 { 514 return class_register(&shost_class); 515 } 516 517 void scsi_exit_hosts(void) 518 { 519 class_unregister(&shost_class); 520 } 521 522 int scsi_is_host_device(const struct device *dev) 523 { 524 return dev->type == &scsi_host_type; 525 } 526 EXPORT_SYMBOL(scsi_is_host_device); 527 528 /** 529 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 530 * @shost: Pointer to Scsi_Host. 531 * @work: Work to queue for execution. 532 * 533 * Return value: 534 * 1 - work queued for execution 535 * 0 - work is already queued 536 * -EINVAL - work queue doesn't exist 537 **/ 538 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 539 { 540 if (unlikely(!shost->work_q)) { 541 printk(KERN_ERR 542 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 543 "when no workqueue created.\n", shost->hostt->name); 544 dump_stack(); 545 546 return -EINVAL; 547 } 548 549 return queue_work(shost->work_q, work); 550 } 551 EXPORT_SYMBOL_GPL(scsi_queue_work); 552 553 /** 554 * scsi_flush_work - Flush a Scsi_Host's workqueue. 555 * @shost: Pointer to Scsi_Host. 556 **/ 557 void scsi_flush_work(struct Scsi_Host *shost) 558 { 559 if (!shost->work_q) { 560 printk(KERN_ERR 561 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 562 "when no workqueue created.\n", shost->hostt->name); 563 dump_stack(); 564 return; 565 } 566 567 flush_workqueue(shost->work_q); 568 } 569 EXPORT_SYMBOL_GPL(scsi_flush_work); 570