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 45static atomic_t scsi_host_next_hn; /* host_no for next new host */ 46 47 48static void scsi_host_cls_release(struct device *dev) 49{ 50 put_device(&class_to_shost(dev)->shost_gendev); 51} 52 53static 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 **/ 66int 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} 151EXPORT_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 **/ 157void 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} 185EXPORT_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 **/ 200int 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 shost->dma_dev = dma_dev; 222 223 error = device_add(&shost->shost_gendev); 224 if (error) 225 goto out; 226 227 pm_runtime_set_active(&shost->shost_gendev); 228 pm_runtime_enable(&shost->shost_gendev); 229 device_enable_async_suspend(&shost->shost_gendev); 230 231 scsi_host_set_state(shost, SHOST_RUNNING); 232 get_device(shost->shost_gendev.parent); 233 234 device_enable_async_suspend(&shost->shost_dev); 235 236 error = device_add(&shost->shost_dev); 237 if (error) 238 goto out_del_gendev; 239 240 get_device(&shost->shost_gendev); 241 242 if (shost->transportt->host_size) { 243 shost->shost_data = kzalloc(shost->transportt->host_size, 244 GFP_KERNEL); 245 if (shost->shost_data == NULL) { 246 error = -ENOMEM; 247 goto out_del_dev; 248 } 249 } 250 251 if (shost->transportt->create_work_queue) { 252 snprintf(shost->work_q_name, sizeof(shost->work_q_name), 253 "scsi_wq_%d", shost->host_no); 254 shost->work_q = create_singlethread_workqueue( 255 shost->work_q_name); 256 if (!shost->work_q) { 257 error = -EINVAL; 258 goto out_free_shost_data; 259 } 260 } 261 262 error = scsi_sysfs_add_host(shost); 263 if (error) 264 goto out_destroy_host; 265 266 scsi_proc_host_add(shost); 267 return error; 268 269 out_destroy_host: 270 if (shost->work_q) 271 destroy_workqueue(shost->work_q); 272 out_free_shost_data: 273 kfree(shost->shost_data); 274 out_del_dev: 275 device_del(&shost->shost_dev); 276 out_del_gendev: 277 device_del(&shost->shost_gendev); 278 out: 279 scsi_destroy_command_freelist(shost); 280 fail: 281 return error; 282} 283EXPORT_SYMBOL(scsi_add_host_with_dma); 284 285static void scsi_host_dev_release(struct device *dev) 286{ 287 struct Scsi_Host *shost = dev_to_shost(dev); 288 struct device *parent = dev->parent; 289 290 scsi_proc_hostdir_rm(shost->hostt); 291 292 if (shost->ehandler) 293 kthread_stop(shost->ehandler); 294 if (shost->work_q) 295 destroy_workqueue(shost->work_q); 296 if (shost->uspace_req_q) { 297 kfree(shost->uspace_req_q->queuedata); 298 scsi_free_queue(shost->uspace_req_q); 299 } 300 301 scsi_destroy_command_freelist(shost); 302 if (shost->bqt) 303 blk_free_tags(shost->bqt); 304 305 kfree(shost->shost_data); 306 307 if (parent) 308 put_device(parent); 309 kfree(shost); 310} 311 312static struct device_type scsi_host_type = { 313 .name = "scsi_host", 314 .release = scsi_host_dev_release, 315}; 316 317/** 318 * scsi_host_alloc - register a scsi host adapter instance. 319 * @sht: pointer to scsi host template 320 * @privsize: extra bytes to allocate for driver 321 * 322 * Note: 323 * Allocate a new Scsi_Host and perform basic initialization. 324 * The host is not published to the scsi midlayer until scsi_add_host 325 * is called. 326 * 327 * Return value: 328 * Pointer to a new Scsi_Host 329 **/ 330struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 331{ 332 struct Scsi_Host *shost; 333 gfp_t gfp_mask = GFP_KERNEL; 334 335 if (sht->unchecked_isa_dma && privsize) 336 gfp_mask |= __GFP_DMA; 337 338 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); 339 if (!shost) 340 return NULL; 341 342 shost->host_lock = &shost->default_lock; 343 spin_lock_init(shost->host_lock); 344 shost->shost_state = SHOST_CREATED; 345 INIT_LIST_HEAD(&shost->__devices); 346 INIT_LIST_HEAD(&shost->__targets); 347 INIT_LIST_HEAD(&shost->eh_cmd_q); 348 INIT_LIST_HEAD(&shost->starved_list); 349 init_waitqueue_head(&shost->host_wait); 350 351 mutex_init(&shost->scan_mutex); 352 353 /* 354 * subtract one because we increment first then return, but we need to 355 * know what the next host number was before increment 356 */ 357 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; 358 shost->dma_channel = 0xff; 359 360 /* These three are default values which can be overridden */ 361 shost->max_channel = 0; 362 shost->max_id = 8; 363 shost->max_lun = 8; 364 365 /* Give each shost a default transportt */ 366 shost->transportt = &blank_transport_template; 367 368 /* 369 * All drivers right now should be able to handle 12 byte 370 * commands. Every so often there are requests for 16 byte 371 * commands, but individual low-level drivers need to certify that 372 * they actually do something sensible with such commands. 373 */ 374 shost->max_cmd_len = 12; 375 shost->hostt = sht; 376 shost->this_id = sht->this_id; 377 shost->can_queue = sht->can_queue; 378 shost->sg_tablesize = sht->sg_tablesize; 379 shost->cmd_per_lun = sht->cmd_per_lun; 380 shost->unchecked_isa_dma = sht->unchecked_isa_dma; 381 shost->use_clustering = sht->use_clustering; 382 shost->ordered_tag = sht->ordered_tag; 383 384 if (sht->supported_mode == MODE_UNKNOWN) 385 /* means we didn't set it ... default to INITIATOR */ 386 shost->active_mode = MODE_INITIATOR; 387 else 388 shost->active_mode = sht->supported_mode; 389 390 if (sht->max_host_blocked) 391 shost->max_host_blocked = sht->max_host_blocked; 392 else 393 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; 394 395 /* 396 * If the driver imposes no hard sector transfer limit, start at 397 * machine infinity initially. 398 */ 399 if (sht->max_sectors) 400 shost->max_sectors = sht->max_sectors; 401 else 402 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; 403 404 /* 405 * assume a 4GB boundary, if not set 406 */ 407 if (sht->dma_boundary) 408 shost->dma_boundary = sht->dma_boundary; 409 else 410 shost->dma_boundary = 0xffffffff; 411 412 device_initialize(&shost->shost_gendev); 413 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); 414#ifndef CONFIG_SYSFS_DEPRECATED 415 shost->shost_gendev.bus = &scsi_bus_type; 416#endif 417 shost->shost_gendev.type = &scsi_host_type; 418 419 device_initialize(&shost->shost_dev); 420 shost->shost_dev.parent = &shost->shost_gendev; 421 shost->shost_dev.class = &shost_class; 422 dev_set_name(&shost->shost_dev, "host%d", shost->host_no); 423 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; 424 425 shost->ehandler = kthread_run(scsi_error_handler, shost, 426 "scsi_eh_%d", shost->host_no); 427 if (IS_ERR(shost->ehandler)) { 428 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n", 429 shost->host_no, PTR_ERR(shost->ehandler)); 430 goto fail_kfree; 431 } 432 433 scsi_proc_hostdir_add(shost->hostt); 434 return shost; 435 436 fail_kfree: 437 kfree(shost); 438 return NULL; 439} 440EXPORT_SYMBOL(scsi_host_alloc); 441 442struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) 443{ 444 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); 445 446 if (!sht->detect) { 447 printk(KERN_WARNING "scsi_register() called on new-style " 448 "template for driver %s\n", sht->name); 449 dump_stack(); 450 } 451 452 if (shost) 453 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); 454 return shost; 455} 456EXPORT_SYMBOL(scsi_register); 457 458void scsi_unregister(struct Scsi_Host *shost) 459{ 460 list_del(&shost->sht_legacy_list); 461 scsi_host_put(shost); 462} 463EXPORT_SYMBOL(scsi_unregister); 464 465static int __scsi_host_match(struct device *dev, void *data) 466{ 467 struct Scsi_Host *p; 468 unsigned short *hostnum = (unsigned short *)data; 469 470 p = class_to_shost(dev); 471 return p->host_no == *hostnum; 472} 473 474/** 475 * scsi_host_lookup - get a reference to a Scsi_Host by host no 476 * @hostnum: host number to locate 477 * 478 * Return value: 479 * A pointer to located Scsi_Host or NULL. 480 * 481 * The caller must do a scsi_host_put() to drop the reference 482 * that scsi_host_get() took. The put_device() below dropped 483 * the reference from class_find_device(). 484 **/ 485struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) 486{ 487 struct device *cdev; 488 struct Scsi_Host *shost = NULL; 489 490 cdev = class_find_device(&shost_class, NULL, &hostnum, 491 __scsi_host_match); 492 if (cdev) { 493 shost = scsi_host_get(class_to_shost(cdev)); 494 put_device(cdev); 495 } 496 return shost; 497} 498EXPORT_SYMBOL(scsi_host_lookup); 499 500/** 501 * scsi_host_get - inc a Scsi_Host ref count 502 * @shost: Pointer to Scsi_Host to inc. 503 **/ 504struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) 505{ 506 if ((shost->shost_state == SHOST_DEL) || 507 !get_device(&shost->shost_gendev)) 508 return NULL; 509 return shost; 510} 511EXPORT_SYMBOL(scsi_host_get); 512 513/** 514 * scsi_host_put - dec a Scsi_Host ref count 515 * @shost: Pointer to Scsi_Host to dec. 516 **/ 517void scsi_host_put(struct Scsi_Host *shost) 518{ 519 put_device(&shost->shost_gendev); 520} 521EXPORT_SYMBOL(scsi_host_put); 522 523int scsi_init_hosts(void) 524{ 525 return class_register(&shost_class); 526} 527 528void scsi_exit_hosts(void) 529{ 530 class_unregister(&shost_class); 531} 532 533int scsi_is_host_device(const struct device *dev) 534{ 535 return dev->type == &scsi_host_type; 536} 537EXPORT_SYMBOL(scsi_is_host_device); 538 539/** 540 * scsi_queue_work - Queue work to the Scsi_Host workqueue. 541 * @shost: Pointer to Scsi_Host. 542 * @work: Work to queue for execution. 543 * 544 * Return value: 545 * 1 - work queued for execution 546 * 0 - work is already queued 547 * -EINVAL - work queue doesn't exist 548 **/ 549int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) 550{ 551 if (unlikely(!shost->work_q)) { 552 printk(KERN_ERR 553 "ERROR: Scsi host '%s' attempted to queue scsi-work, " 554 "when no workqueue created.\n", shost->hostt->name); 555 dump_stack(); 556 557 return -EINVAL; 558 } 559 560 return queue_work(shost->work_q, work); 561} 562EXPORT_SYMBOL_GPL(scsi_queue_work); 563 564/** 565 * scsi_flush_work - Flush a Scsi_Host's workqueue. 566 * @shost: Pointer to Scsi_Host. 567 **/ 568void scsi_flush_work(struct Scsi_Host *shost) 569{ 570 if (!shost->work_q) { 571 printk(KERN_ERR 572 "ERROR: Scsi host '%s' attempted to flush scsi-work, " 573 "when no workqueue created.\n", shost->hostt->name); 574 dump_stack(); 575 return; 576 } 577 578 flush_workqueue(shost->work_q); 579} 580EXPORT_SYMBOL_GPL(scsi_flush_work); 581