drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 #define DASD_DIAG_MOD           "dasd_diag_mod"
  42
  43 /*
  44  * SECTION: exported variables of dasd.c
  45  */
  46 debug_info_t *dasd_debug_area;
  47 EXPORT_SYMBOL(dasd_debug_area);
  48 static struct dentry *dasd_debugfs_root_entry;
  49 struct dasd_discipline *dasd_diag_discipline_pointer;
  50 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  52
  53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  55                    " Copyright IBM Corp. 2000");
  56 MODULE_SUPPORTED_DEVICE("dasd");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int  dasd_alloc_queue(struct dasd_block *);
  63 static void dasd_setup_queue(struct dasd_block *);
  64 static void dasd_free_queue(struct dasd_block *);
  65 static void dasd_flush_request_queue(struct dasd_block *);
  66 static int dasd_flush_block_queue(struct dasd_block *);
  67 static void dasd_device_tasklet(struct dasd_device *);
  68 static void dasd_block_tasklet(struct dasd_block *);
  69 static void do_kick_device(struct work_struct *);
  70 static void do_restore_device(struct work_struct *);
  71 static void do_reload_device(struct work_struct *);
  72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  73 static void dasd_device_timeout(unsigned long);
  74 static void dasd_block_timeout(unsigned long);
  75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  77 static void dasd_profile_exit(struct dasd_profile *);
  78 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  79 static void dasd_hosts_exit(struct dasd_device *);
  80
  81 /*
  82  * SECTION: Operations on the device structure.
  83  */
  84 static wait_queue_head_t dasd_init_waitq;
  85 static wait_queue_head_t dasd_flush_wq;
  86 static wait_queue_head_t generic_waitq;
  87 static wait_queue_head_t shutdown_waitq;
  88
  89 /*
  90  * Allocate memory for a new device structure.
  91  */
  92 struct dasd_device *dasd_alloc_device(void)
  93 {
  94         struct dasd_device *device;
  95
  96         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  97         if (!device)
  98                 return ERR_PTR(-ENOMEM);
  99
 100         /* Get two pages for normal block device operations. */
 101         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 102         if (!device->ccw_mem) {
 103                 kfree(device);
 104                 return ERR_PTR(-ENOMEM);
 105         }
 106         /* Get one page for error recovery. */
 107         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 108         if (!device->erp_mem) {
 109                 free_pages((unsigned long) device->ccw_mem, 1);
 110                 kfree(device);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 115         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 116         spin_lock_init(&device->mem_lock);
 117         atomic_set(&device->tasklet_scheduled, 0);
 118         tasklet_init(&device->tasklet,
 119                      (void (*)(unsigned long)) dasd_device_tasklet,
 120                      (unsigned long) device);
 121         INIT_LIST_HEAD(&device->ccw_queue);
 122         init_timer(&device->timer);
 123         device->timer.function = dasd_device_timeout;
 124         device->timer.data = (unsigned long) device;
 125         INIT_WORK(&device->kick_work, do_kick_device);
 126         INIT_WORK(&device->restore_device, do_restore_device);
 127         INIT_WORK(&device->reload_device, do_reload_device);
 128         device->state = DASD_STATE_NEW;
 129         device->target = DASD_STATE_NEW;
 130         mutex_init(&device->state_mutex);
 131         spin_lock_init(&device->profile.lock);
 132         return device;
 133 }
 134
 135 /*
 136  * Free memory of a device structure.
 137  */
 138 void dasd_free_device(struct dasd_device *device)
 139 {
 140         kfree(device->private);
 141         free_page((unsigned long) device->erp_mem);
 142         free_pages((unsigned long) device->ccw_mem, 1);
 143         kfree(device);
 144 }
 145
 146 /*
 147  * Allocate memory for a new device structure.
 148  */
 149 struct dasd_block *dasd_alloc_block(void)
 150 {
 151         struct dasd_block *block;
 152
 153         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 154         if (!block)
 155                 return ERR_PTR(-ENOMEM);
 156         /* open_count = 0 means device online but not in use */
 157         atomic_set(&block->open_count, -1);
 158
 159         spin_lock_init(&block->request_queue_lock);
 160         atomic_set(&block->tasklet_scheduled, 0);
 161         tasklet_init(&block->tasklet,
 162                      (void (*)(unsigned long)) dasd_block_tasklet,
 163                      (unsigned long) block);
 164         INIT_LIST_HEAD(&block->ccw_queue);
 165         spin_lock_init(&block->queue_lock);
 166         init_timer(&block->timer);
 167         block->timer.function = dasd_block_timeout;
 168         block->timer.data = (unsigned long) block;
 169         spin_lock_init(&block->profile.lock);
 170
 171         return block;
 172 }
 173 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 174
 175 /*
 176  * Free memory of a device structure.
 177  */
 178 void dasd_free_block(struct dasd_block *block)
 179 {
 180         kfree(block);
 181 }
 182 EXPORT_SYMBOL_GPL(dasd_free_block);
 183
 184 /*
 185  * Make a new device known to the system.
 186  */
 187 static int dasd_state_new_to_known(struct dasd_device *device)
 188 {
 189         int rc;
 190
 191         /*
 192          * As long as the device is not in state DASD_STATE_NEW we want to
 193          * keep the reference count > 0.
 194          */
 195         dasd_get_device(device);
 196
 197         if (device->block) {
 198                 rc = dasd_alloc_queue(device->block);
 199                 if (rc) {
 200                         dasd_put_device(device);
 201                         return rc;
 202                 }
 203         }
 204         device->state = DASD_STATE_KNOWN;
 205         return 0;
 206 }
 207
 208 /*
 209  * Let the system forget about a device.
 210  */
 211 static int dasd_state_known_to_new(struct dasd_device *device)
 212 {
 213         /* Disable extended error reporting for this device. */
 214         dasd_eer_disable(device);
 215         /* Forget the discipline information. */
 216         if (device->discipline) {
 217                 if (device->discipline->uncheck_device)
 218                         device->discipline->uncheck_device(device);
 219                 module_put(device->discipline->owner);
 220         }
 221         device->discipline = NULL;
 222         if (device->base_discipline)
 223                 module_put(device->base_discipline->owner);
 224         device->base_discipline = NULL;
 225         device->state = DASD_STATE_NEW;
 226
 227         if (device->block)
 228                 dasd_free_queue(device->block);
 229
 230         /* Give up reference we took in dasd_state_new_to_known. */
 231         dasd_put_device(device);
 232         return 0;
 233 }
 234
 235 static struct dentry *dasd_debugfs_setup(const char *name,
 236                                          struct dentry *base_dentry)
 237 {
 238         struct dentry *pde;
 239
 240         if (!base_dentry)
 241                 return NULL;
 242         pde = debugfs_create_dir(name, base_dentry);
 243         if (!pde || IS_ERR(pde))
 244                 return NULL;
 245         return pde;
 246 }
 247
 248 /*
 249  * Request the irq line for the device.
 250  */
 251 static int dasd_state_known_to_basic(struct dasd_device *device)
 252 {
 253         struct dasd_block *block = device->block;
 254         int rc = 0;
 255
 256         /* Allocate and register gendisk structure. */
 257         if (block) {
 258                 rc = dasd_gendisk_alloc(block);
 259                 if (rc)
 260                         return rc;
 261                 block->debugfs_dentry =
 262                         dasd_debugfs_setup(block->gdp->disk_name,
 263                                            dasd_debugfs_root_entry);
 264                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 265                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 266                         dasd_profile_on(&device->block->profile);
 267         }
 268         device->debugfs_dentry =
 269                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 270                                    dasd_debugfs_root_entry);
 271         dasd_profile_init(&device->profile, device->debugfs_dentry);
 272         dasd_hosts_init(device->debugfs_dentry, device);
 273
 274         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 275         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 276                                             8 * sizeof(long));
 277         debug_register_view(device->debug_area, &debug_sprintf_view);
 278         debug_set_level(device->debug_area, DBF_WARNING);
 279         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 280
 281         device->state = DASD_STATE_BASIC;
 282
 283         return rc;
 284 }
 285
 286 /*
 287  * Release the irq line for the device. Terminate any running i/o.
 288  */
 289 static int dasd_state_basic_to_known(struct dasd_device *device)
 290 {
 291         int rc;
 292
 293         if (device->discipline->basic_to_known) {
 294                 rc = device->discipline->basic_to_known(device);
 295                 if (rc)
 296                         return rc;
 297         }
 298
 299         if (device->block) {
 300                 dasd_profile_exit(&device->block->profile);
 301                 debugfs_remove(device->block->debugfs_dentry);
 302                 dasd_gendisk_free(device->block);
 303                 dasd_block_clear_timer(device->block);
 304         }
 305         rc = dasd_flush_device_queue(device);
 306         if (rc)
 307                 return rc;
 308         dasd_device_clear_timer(device);
 309         dasd_profile_exit(&device->profile);
 310         dasd_hosts_exit(device);
 311         debugfs_remove(device->debugfs_dentry);
 312         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 313         if (device->debug_area != NULL) {
 314                 debug_unregister(device->debug_area);
 315                 device->debug_area = NULL;
 316         }
 317         device->state = DASD_STATE_KNOWN;
 318         return 0;
 319 }
 320
 321 /*
 322  * Do the initial analysis. The do_analysis function may return
 323  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 324  * until the discipline decides to continue the startup sequence
 325  * by calling the function dasd_change_state. The eckd disciplines
 326  * uses this to start a ccw that detects the format. The completion
 327  * interrupt for this detection ccw uses the kernel event daemon to
 328  * trigger the call to dasd_change_state. All this is done in the
 329  * discipline code, see dasd_eckd.c.
 330  * After the analysis ccw is done (do_analysis returned 0) the block
 331  * device is setup.
 332  * In case the analysis returns an error, the device setup is stopped
 333  * (a fake disk was already added to allow formatting).
 334  */
 335 static int dasd_state_basic_to_ready(struct dasd_device *device)
 336 {
 337         int rc;
 338         struct dasd_block *block;
 339
 340         rc = 0;
 341         block = device->block;
 342         /* make disk known with correct capacity */
 343         if (block) {
 344                 if (block->base->discipline->do_analysis != NULL)
 345                         rc = block->base->discipline->do_analysis(block);
 346                 if (rc) {
 347                         if (rc != -EAGAIN) {
 348                                 device->state = DASD_STATE_UNFMT;
 349                                 goto out;
 350                         }
 351                         return rc;
 352                 }
 353                 dasd_setup_queue(block);
 354                 set_capacity(block->gdp,
 355                              block->blocks << block->s2b_shift);
 356                 device->state = DASD_STATE_READY;
 357                 rc = dasd_scan_partitions(block);
 358                 if (rc) {
 359                         device->state = DASD_STATE_BASIC;
 360                         return rc;
 361                 }
 362         } else {
 363                 device->state = DASD_STATE_READY;
 364         }
 365 out:
 366         if (device->discipline->basic_to_ready)
 367                 rc = device->discipline->basic_to_ready(device);
 368         return rc;
 369 }
 370
 371 static inline
 372 int _wait_for_empty_queues(struct dasd_device *device)
 373 {
 374         if (device->block)
 375                 return list_empty(&device->ccw_queue) &&
 376                         list_empty(&device->block->ccw_queue);
 377         else
 378                 return list_empty(&device->ccw_queue);
 379 }
 380
 381 /*
 382  * Remove device from block device layer. Destroy dirty buffers.
 383  * Forget format information. Check if the target level is basic
 384  * and if it is create fake disk for formatting.
 385  */
 386 static int dasd_state_ready_to_basic(struct dasd_device *device)
 387 {
 388         int rc;
 389
 390         device->state = DASD_STATE_BASIC;
 391         if (device->block) {
 392                 struct dasd_block *block = device->block;
 393                 rc = dasd_flush_block_queue(block);
 394                 if (rc) {
 395                         device->state = DASD_STATE_READY;
 396                         return rc;
 397                 }
 398                 dasd_flush_request_queue(block);
 399                 dasd_destroy_partitions(block);
 400                 block->blocks = 0;
 401                 block->bp_block = 0;
 402                 block->s2b_shift = 0;
 403         }
 404         return 0;
 405 }
 406
 407 /*
 408  * Back to basic.
 409  */
 410 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 411 {
 412         device->state = DASD_STATE_BASIC;
 413         return 0;
 414 }
 415
 416 /*
 417  * Make the device online and schedule the bottom half to start
 418  * the requeueing of requests from the linux request queue to the
 419  * ccw queue.
 420  */
 421 static int
 422 dasd_state_ready_to_online(struct dasd_device * device)
 423 {
 424         struct gendisk *disk;
 425         struct disk_part_iter piter;
 426         struct hd_struct *part;
 427
 428         device->state = DASD_STATE_ONLINE;
 429         if (device->block) {
 430                 dasd_schedule_block_bh(device->block);
 431                 if ((device->features & DASD_FEATURE_USERAW)) {
 432                         disk = device->block->gdp;
 433                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 434                         return 0;
 435                 }
 436                 disk = device->block->bdev->bd_disk;
 437                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 438                 while ((part = disk_part_iter_next(&piter)))
 439                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 440                 disk_part_iter_exit(&piter);
 441         }
 442         return 0;
 443 }
 444
 445 /*
 446  * Stop the requeueing of requests again.
 447  */
 448 static int dasd_state_online_to_ready(struct dasd_device *device)
 449 {
 450         int rc;
 451         struct gendisk *disk;
 452         struct disk_part_iter piter;
 453         struct hd_struct *part;
 454
 455         if (device->discipline->online_to_ready) {
 456                 rc = device->discipline->online_to_ready(device);
 457                 if (rc)
 458                         return rc;
 459         }
 460
 461         device->state = DASD_STATE_READY;
 462         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 463                 disk = device->block->bdev->bd_disk;
 464                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 465                 while ((part = disk_part_iter_next(&piter)))
 466                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 467                 disk_part_iter_exit(&piter);
 468         }
 469         return 0;
 470 }
 471
 472 /*
 473  * Device startup state changes.
 474  */
 475 static int dasd_increase_state(struct dasd_device *device)
 476 {
 477         int rc;
 478
 479         rc = 0;
 480         if (device->state == DASD_STATE_NEW &&
 481             device->target >= DASD_STATE_KNOWN)
 482                 rc = dasd_state_new_to_known(device);
 483
 484         if (!rc &&
 485             device->state == DASD_STATE_KNOWN &&
 486             device->target >= DASD_STATE_BASIC)
 487                 rc = dasd_state_known_to_basic(device);
 488
 489         if (!rc &&
 490             device->state == DASD_STATE_BASIC &&
 491             device->target >= DASD_STATE_READY)
 492                 rc = dasd_state_basic_to_ready(device);
 493
 494         if (!rc &&
 495             device->state == DASD_STATE_UNFMT &&
 496             device->target > DASD_STATE_UNFMT)
 497                 rc = -EPERM;
 498
 499         if (!rc &&
 500             device->state == DASD_STATE_READY &&
 501             device->target >= DASD_STATE_ONLINE)
 502                 rc = dasd_state_ready_to_online(device);
 503
 504         return rc;
 505 }
 506
 507 /*
 508  * Device shutdown state changes.
 509  */
 510 static int dasd_decrease_state(struct dasd_device *device)
 511 {
 512         int rc;
 513
 514         rc = 0;
 515         if (device->state == DASD_STATE_ONLINE &&
 516             device->target <= DASD_STATE_READY)
 517                 rc = dasd_state_online_to_ready(device);
 518
 519         if (!rc &&
 520             device->state == DASD_STATE_READY &&
 521             device->target <= DASD_STATE_BASIC)
 522                 rc = dasd_state_ready_to_basic(device);
 523
 524         if (!rc &&
 525             device->state == DASD_STATE_UNFMT &&
 526             device->target <= DASD_STATE_BASIC)
 527                 rc = dasd_state_unfmt_to_basic(device);
 528
 529         if (!rc &&
 530             device->state == DASD_STATE_BASIC &&
 531             device->target <= DASD_STATE_KNOWN)
 532                 rc = dasd_state_basic_to_known(device);
 533
 534         if (!rc &&
 535             device->state == DASD_STATE_KNOWN &&
 536             device->target <= DASD_STATE_NEW)
 537                 rc = dasd_state_known_to_new(device);
 538
 539         return rc;
 540 }
 541
 542 /*
 543  * This is the main startup/shutdown routine.
 544  */
 545 static void dasd_change_state(struct dasd_device *device)
 546 {
 547         int rc;
 548
 549         if (device->state == device->target)
 550                 /* Already where we want to go today... */
 551                 return;
 552         if (device->state < device->target)
 553                 rc = dasd_increase_state(device);
 554         else
 555                 rc = dasd_decrease_state(device);
 556         if (rc == -EAGAIN)
 557                 return;
 558         if (rc)
 559                 device->target = device->state;
 560
 561         /* let user-space know that the device status changed */
 562         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 563
 564         if (device->state == device->target)
 565                 wake_up(&dasd_init_waitq);
 566 }
 567
 568 /*
 569  * Kick starter for devices that did not complete the startup/shutdown
 570  * procedure or were sleeping because of a pending state.
 571  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 572  * event daemon.
 573  */
 574 static void do_kick_device(struct work_struct *work)
 575 {
 576         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 577         mutex_lock(&device->state_mutex);
 578         dasd_change_state(device);
 579         mutex_unlock(&device->state_mutex);
 580         dasd_schedule_device_bh(device);
 581         dasd_put_device(device);
 582 }
 583
 584 void dasd_kick_device(struct dasd_device *device)
 585 {
 586         dasd_get_device(device);
 587         /* queue call to dasd_kick_device to the kernel event daemon. */
 588         if (!schedule_work(&device->kick_work))
 589                 dasd_put_device(device);
 590 }
 591 EXPORT_SYMBOL(dasd_kick_device);
 592
 593 /*
 594  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 595  * event daemon.
 596  */
 597 static void do_reload_device(struct work_struct *work)
 598 {
 599         struct dasd_device *device = container_of(work, struct dasd_device,
 600                                                   reload_device);
 601         device->discipline->reload(device);
 602         dasd_put_device(device);
 603 }
 604
 605 void dasd_reload_device(struct dasd_device *device)
 606 {
 607         dasd_get_device(device);
 608         /* queue call to dasd_reload_device to the kernel event daemon. */
 609         if (!schedule_work(&device->reload_device))
 610                 dasd_put_device(device);
 611 }
 612 EXPORT_SYMBOL(dasd_reload_device);
 613
 614 /*
 615  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 616  * event daemon.
 617  */
 618 static void do_restore_device(struct work_struct *work)
 619 {
 620         struct dasd_device *device = container_of(work, struct dasd_device,
 621                                                   restore_device);
 622         device->cdev->drv->restore(device->cdev);
 623         dasd_put_device(device);
 624 }
 625
 626 void dasd_restore_device(struct dasd_device *device)
 627 {
 628         dasd_get_device(device);
 629         /* queue call to dasd_restore_device to the kernel event daemon. */
 630         if (!schedule_work(&device->restore_device))
 631                 dasd_put_device(device);
 632 }
 633
 634 /*
 635  * Set the target state for a device and starts the state change.
 636  */
 637 void dasd_set_target_state(struct dasd_device *device, int target)
 638 {
 639         dasd_get_device(device);
 640         mutex_lock(&device->state_mutex);
 641         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 642         if (dasd_probeonly && target > DASD_STATE_READY)
 643                 target = DASD_STATE_READY;
 644         if (device->target != target) {
 645                 if (device->state == target)
 646                         wake_up(&dasd_init_waitq);
 647                 device->target = target;
 648         }
 649         if (device->state != device->target)
 650                 dasd_change_state(device);
 651         mutex_unlock(&device->state_mutex);
 652         dasd_put_device(device);
 653 }
 654 EXPORT_SYMBOL(dasd_set_target_state);
 655
 656 /*
 657  * Enable devices with device numbers in [from..to].
 658  */
 659 static inline int _wait_for_device(struct dasd_device *device)
 660 {
 661         return (device->state == device->target);
 662 }
 663
 664 void dasd_enable_device(struct dasd_device *device)
 665 {
 666         dasd_set_target_state(device, DASD_STATE_ONLINE);
 667         if (device->state <= DASD_STATE_KNOWN)
 668                 /* No discipline for device found. */
 669                 dasd_set_target_state(device, DASD_STATE_NEW);
 670         /* Now wait for the devices to come up. */
 671         wait_event(dasd_init_waitq, _wait_for_device(device));
 672
 673         dasd_reload_device(device);
 674         if (device->discipline->kick_validate)
 675                 device->discipline->kick_validate(device);
 676 }
 677 EXPORT_SYMBOL(dasd_enable_device);
 678
 679 /*
 680  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 681  */
 682
 683 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 684
 685 #ifdef CONFIG_DASD_PROFILE
 686 struct dasd_profile dasd_global_profile = {
 687         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 688 };
 689 static struct dentry *dasd_debugfs_global_entry;
 690
 691 /*
 692  * Add profiling information for cqr before execution.
 693  */
 694 static void dasd_profile_start(struct dasd_block *block,
 695                                struct dasd_ccw_req *cqr,
 696                                struct request *req)
 697 {
 698         struct list_head *l;
 699         unsigned int counter;
 700         struct dasd_device *device;
 701
 702         /* count the length of the chanq for statistics */
 703         counter = 0;
 704         if (dasd_global_profile_level || block->profile.data)
 705                 list_for_each(l, &block->ccw_queue)
 706                         if (++counter >= 31)
 707                                 break;
 708
 709         spin_lock(&dasd_global_profile.lock);
 710         if (dasd_global_profile.data) {
 711                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 712                 if (rq_data_dir(req) == READ)
 713                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 714         }
 715         spin_unlock(&dasd_global_profile.lock);
 716
 717         spin_lock(&block->profile.lock);
 718         if (block->profile.data) {
 719                 block->profile.data->dasd_io_nr_req[counter]++;
 720                 if (rq_data_dir(req) == READ)
 721                         block->profile.data->dasd_read_nr_req[counter]++;
 722         }
 723         spin_unlock(&block->profile.lock);
 724
 725         /*
 726          * We count the request for the start device, even though it may run on
 727          * some other device due to error recovery. This way we make sure that
 728          * we count each request only once.
 729          */
 730         device = cqr->startdev;
 731         if (device->profile.data) {
 732                 counter = 1; /* request is not yet queued on the start device */
 733                 list_for_each(l, &device->ccw_queue)
 734                         if (++counter >= 31)
 735                                 break;
 736         }
 737         spin_lock(&device->profile.lock);
 738         if (device->profile.data) {
 739                 device->profile.data->dasd_io_nr_req[counter]++;
 740                 if (rq_data_dir(req) == READ)
 741                         device->profile.data->dasd_read_nr_req[counter]++;
 742         }
 743         spin_unlock(&device->profile.lock);
 744 }
 745
 746 /*
 747  * Add profiling information for cqr after execution.
 748  */
 749
 750 #define dasd_profile_counter(value, index)                         \
 751 {                                                                  \
 752         for (index = 0; index < 31 && value >> (2+index); index++) \
 753                 ;                                                  \
 754 }
 755
 756 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 757                                       int is_alias,
 758                                       int is_tpm,
 759                                       int is_read,
 760                                       long sectors,
 761                                       int sectors_ind,
 762                                       int tottime_ind,
 763                                       int tottimeps_ind,
 764                                       int strtime_ind,
 765                                       int irqtime_ind,
 766                                       int irqtimeps_ind,
 767                                       int endtime_ind)
 768 {
 769         /* in case of an overflow, reset the whole profile */
 770         if (data->dasd_io_reqs == UINT_MAX) {
 771                         memset(data, 0, sizeof(*data));
 772                         getnstimeofday(&data->starttod);
 773         }
 774         data->dasd_io_reqs++;
 775         data->dasd_io_sects += sectors;
 776         if (is_alias)
 777                 data->dasd_io_alias++;
 778         if (is_tpm)
 779                 data->dasd_io_tpm++;
 780
 781         data->dasd_io_secs[sectors_ind]++;
 782         data->dasd_io_times[tottime_ind]++;
 783         data->dasd_io_timps[tottimeps_ind]++;
 784         data->dasd_io_time1[strtime_ind]++;
 785         data->dasd_io_time2[irqtime_ind]++;
 786         data->dasd_io_time2ps[irqtimeps_ind]++;
 787         data->dasd_io_time3[endtime_ind]++;
 788
 789         if (is_read) {
 790                 data->dasd_read_reqs++;
 791                 data->dasd_read_sects += sectors;
 792                 if (is_alias)
 793                         data->dasd_read_alias++;
 794                 if (is_tpm)
 795                         data->dasd_read_tpm++;
 796                 data->dasd_read_secs[sectors_ind]++;
 797                 data->dasd_read_times[tottime_ind]++;
 798                 data->dasd_read_time1[strtime_ind]++;
 799                 data->dasd_read_time2[irqtime_ind]++;
 800                 data->dasd_read_time3[endtime_ind]++;
 801         }
 802 }
 803
 804 static void dasd_profile_end(struct dasd_block *block,
 805                              struct dasd_ccw_req *cqr,
 806                              struct request *req)
 807 {
 808         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 809         long tottimeps, sectors;
 810         struct dasd_device *device;
 811         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 812         int irqtime_ind, irqtimeps_ind, endtime_ind;
 813
 814         device = cqr->startdev;
 815         if (!(dasd_global_profile_level ||
 816               block->profile.data ||
 817               device->profile.data))
 818                 return;
 819
 820         sectors = blk_rq_sectors(req);
 821         if (!cqr->buildclk || !cqr->startclk ||
 822             !cqr->stopclk || !cqr->endclk ||
 823             !sectors)
 824                 return;
 825
 826         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 827         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 828         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 829         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 830         tottimeps = tottime / sectors;
 831
 832         dasd_profile_counter(sectors, sectors_ind);
 833         dasd_profile_counter(tottime, tottime_ind);
 834         dasd_profile_counter(tottimeps, tottimeps_ind);
 835         dasd_profile_counter(strtime, strtime_ind);
 836         dasd_profile_counter(irqtime, irqtime_ind);
 837         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 838         dasd_profile_counter(endtime, endtime_ind);
 839
 840         spin_lock(&dasd_global_profile.lock);
 841         if (dasd_global_profile.data) {
 842                 dasd_profile_end_add_data(dasd_global_profile.data,
 843                                           cqr->startdev != block->base,
 844                                           cqr->cpmode == 1,
 845                                           rq_data_dir(req) == READ,
 846                                           sectors, sectors_ind, tottime_ind,
 847                                           tottimeps_ind, strtime_ind,
 848                                           irqtime_ind, irqtimeps_ind,
 849                                           endtime_ind);
 850         }
 851         spin_unlock(&dasd_global_profile.lock);
 852
 853         spin_lock(&block->profile.lock);
 854         if (block->profile.data)
 855                 dasd_profile_end_add_data(block->profile.data,
 856                                           cqr->startdev != block->base,
 857                                           cqr->cpmode == 1,
 858                                           rq_data_dir(req) == READ,
 859                                           sectors, sectors_ind, tottime_ind,
 860                                           tottimeps_ind, strtime_ind,
 861                                           irqtime_ind, irqtimeps_ind,
 862                                           endtime_ind);
 863         spin_unlock(&block->profile.lock);
 864
 865         spin_lock(&device->profile.lock);
 866         if (device->profile.data)
 867                 dasd_profile_end_add_data(device->profile.data,
 868                                           cqr->startdev != block->base,
 869                                           cqr->cpmode == 1,
 870                                           rq_data_dir(req) == READ,
 871                                           sectors, sectors_ind, tottime_ind,
 872                                           tottimeps_ind, strtime_ind,
 873                                           irqtime_ind, irqtimeps_ind,
 874                                           endtime_ind);
 875         spin_unlock(&device->profile.lock);
 876 }
 877
 878 void dasd_profile_reset(struct dasd_profile *profile)
 879 {
 880         struct dasd_profile_info *data;
 881
 882         spin_lock_bh(&profile->lock);
 883         data = profile->data;
 884         if (!data) {
 885                 spin_unlock_bh(&profile->lock);
 886                 return;
 887         }
 888         memset(data, 0, sizeof(*data));
 889         getnstimeofday(&data->starttod);
 890         spin_unlock_bh(&profile->lock);
 891 }
 892
 893 int dasd_profile_on(struct dasd_profile *profile)
 894 {
 895         struct dasd_profile_info *data;
 896
 897         data = kzalloc(sizeof(*data), GFP_KERNEL);
 898         if (!data)
 899                 return -ENOMEM;
 900         spin_lock_bh(&profile->lock);
 901         if (profile->data) {
 902                 spin_unlock_bh(&profile->lock);
 903                 kfree(data);
 904                 return 0;
 905         }
 906         getnstimeofday(&data->starttod);
 907         profile->data = data;
 908         spin_unlock_bh(&profile->lock);
 909         return 0;
 910 }
 911
 912 void dasd_profile_off(struct dasd_profile *profile)
 913 {
 914         spin_lock_bh(&profile->lock);
 915         kfree(profile->data);
 916         profile->data = NULL;
 917         spin_unlock_bh(&profile->lock);
 918 }
 919
 920 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 921 {
 922         char *buffer;
 923
 924         buffer = vmalloc(user_len + 1);
 925         if (buffer == NULL)
 926                 return ERR_PTR(-ENOMEM);
 927         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 928                 vfree(buffer);
 929                 return ERR_PTR(-EFAULT);
 930         }
 931         /* got the string, now strip linefeed. */
 932         if (buffer[user_len - 1] == '\n')
 933                 buffer[user_len - 1] = 0;
 934         else
 935                 buffer[user_len] = 0;
 936         return buffer;
 937 }
 938
 939 static ssize_t dasd_stats_write(struct file *file,
 940                                 const char __user *user_buf,
 941                                 size_t user_len, loff_t *pos)
 942 {
 943         char *buffer, *str;
 944         int rc;
 945         struct seq_file *m = (struct seq_file *)file->private_data;
 946         struct dasd_profile *prof = m->private;
 947
 948         if (user_len > 65536)
 949                 user_len = 65536;
 950         buffer = dasd_get_user_string(user_buf, user_len);
 951         if (IS_ERR(buffer))
 952                 return PTR_ERR(buffer);
 953
 954         str = skip_spaces(buffer);
 955         rc = user_len;
 956         if (strncmp(str, "reset", 5) == 0) {
 957                 dasd_profile_reset(prof);
 958         } else if (strncmp(str, "on", 2) == 0) {
 959                 rc = dasd_profile_on(prof);
 960                 if (rc)
 961                         goto out;
 962                 rc = user_len;
 963                 if (prof == &dasd_global_profile) {
 964                         dasd_profile_reset(prof);
 965                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 966                 }
 967         } else if (strncmp(str, "off", 3) == 0) {
 968                 if (prof == &dasd_global_profile)
 969                         dasd_global_profile_level = DASD_PROFILE_OFF;
 970                 dasd_profile_off(prof);
 971         } else
 972                 rc = -EINVAL;
 973 out:
 974         vfree(buffer);
 975         return rc;
 976 }
 977
 978 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 979 {
 980         int i;
 981
 982         for (i = 0; i < 32; i++)
 983                 seq_printf(m, "%u ", array[i]);
 984         seq_putc(m, '\n');
 985 }
 986
 987 static void dasd_stats_seq_print(struct seq_file *m,
 988                                  struct dasd_profile_info *data)
 989 {
 990         seq_printf(m, "start_time %ld.%09ld\n",
 991                    data->starttod.tv_sec, data->starttod.tv_nsec);
 992         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 993         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 994         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 995         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 996         seq_puts(m, "histogram_sectors ");
 997         dasd_stats_array(m, data->dasd_io_secs);
 998         seq_puts(m, "histogram_io_times ");
 999         dasd_stats_array(m, data->dasd_io_times);
1000         seq_puts(m, "histogram_io_times_weighted ");
1001         dasd_stats_array(m, data->dasd_io_timps);
1002         seq_puts(m, "histogram_time_build_to_ssch ");
1003         dasd_stats_array(m, data->dasd_io_time1);
1004         seq_puts(m, "histogram_time_ssch_to_irq ");
1005         dasd_stats_array(m, data->dasd_io_time2);
1006         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1007         dasd_stats_array(m, data->dasd_io_time2ps);
1008         seq_puts(m, "histogram_time_irq_to_end ");
1009         dasd_stats_array(m, data->dasd_io_time3);
1010         seq_puts(m, "histogram_ccw_queue_length ");
1011         dasd_stats_array(m, data->dasd_io_nr_req);
1012         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1013         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1014         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1015         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1016         seq_puts(m, "histogram_read_sectors ");
1017         dasd_stats_array(m, data->dasd_read_secs);
1018         seq_puts(m, "histogram_read_times ");
1019         dasd_stats_array(m, data->dasd_read_times);
1020         seq_puts(m, "histogram_read_time_build_to_ssch ");
1021         dasd_stats_array(m, data->dasd_read_time1);
1022         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1023         dasd_stats_array(m, data->dasd_read_time2);
1024         seq_puts(m, "histogram_read_time_irq_to_end ");
1025         dasd_stats_array(m, data->dasd_read_time3);
1026         seq_puts(m, "histogram_read_ccw_queue_length ");
1027         dasd_stats_array(m, data->dasd_read_nr_req);
1028 }
1029
1030 static int dasd_stats_show(struct seq_file *m, void *v)
1031 {
1032         struct dasd_profile *profile;
1033         struct dasd_profile_info *data;
1034
1035         profile = m->private;
1036         spin_lock_bh(&profile->lock);
1037         data = profile->data;
1038         if (!data) {
1039                 spin_unlock_bh(&profile->lock);
1040                 seq_puts(m, "disabled\n");
1041                 return 0;
1042         }
1043         dasd_stats_seq_print(m, data);
1044         spin_unlock_bh(&profile->lock);
1045         return 0;
1046 }
1047
1048 static int dasd_stats_open(struct inode *inode, struct file *file)
1049 {
1050         struct dasd_profile *profile = inode->i_private;
1051         return single_open(file, dasd_stats_show, profile);
1052 }
1053
1054 static const struct file_operations dasd_stats_raw_fops = {
1055         .owner          = THIS_MODULE,
1056         .open           = dasd_stats_open,
1057         .read           = seq_read,
1058         .llseek         = seq_lseek,
1059         .release        = single_release,
1060         .write          = dasd_stats_write,
1061 };
1062
1063 static void dasd_profile_init(struct dasd_profile *profile,
1064                               struct dentry *base_dentry)
1065 {
1066         umode_t mode;
1067         struct dentry *pde;
1068
1069         if (!base_dentry)
1070                 return;
1071         profile->dentry = NULL;
1072         profile->data = NULL;
1073         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1074         pde = debugfs_create_file("statistics", mode, base_dentry,
1075                                   profile, &dasd_stats_raw_fops);
1076         if (pde && !IS_ERR(pde))
1077                 profile->dentry = pde;
1078         return;
1079 }
1080
1081 static void dasd_profile_exit(struct dasd_profile *profile)
1082 {
1083         dasd_profile_off(profile);
1084         debugfs_remove(profile->dentry);
1085         profile->dentry = NULL;
1086 }
1087
1088 static void dasd_statistics_removeroot(void)
1089 {
1090         dasd_global_profile_level = DASD_PROFILE_OFF;
1091         dasd_profile_exit(&dasd_global_profile);
1092         debugfs_remove(dasd_debugfs_global_entry);
1093         debugfs_remove(dasd_debugfs_root_entry);
1094 }
1095
1096 static void dasd_statistics_createroot(void)
1097 {
1098         struct dentry *pde;
1099
1100         dasd_debugfs_root_entry = NULL;
1101         pde = debugfs_create_dir("dasd", NULL);
1102         if (!pde || IS_ERR(pde))
1103                 goto error;
1104         dasd_debugfs_root_entry = pde;
1105         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1106         if (!pde || IS_ERR(pde))
1107                 goto error;
1108         dasd_debugfs_global_entry = pde;
1109         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1110         return;
1111
1112 error:
1113         DBF_EVENT(DBF_ERR, "%s",
1114                   "Creation of the dasd debugfs interface failed");
1115         dasd_statistics_removeroot();
1116         return;
1117 }
1118
1119 #else
1120 #define dasd_profile_start(block, cqr, req) do {} while (0)
1121 #define dasd_profile_end(block, cqr, req) do {} while (0)
1122
1123 static void dasd_statistics_createroot(void)
1124 {
1125         return;
1126 }
1127
1128 static void dasd_statistics_removeroot(void)
1129 {
1130         return;
1131 }
1132
1133 int dasd_stats_generic_show(struct seq_file *m, void *v)
1134 {
1135         seq_puts(m, "Statistics are not activated in this kernel\n");
1136         return 0;
1137 }
1138
1139 static void dasd_profile_init(struct dasd_profile *profile,
1140                               struct dentry *base_dentry)
1141 {
1142         return;
1143 }
1144
1145 static void dasd_profile_exit(struct dasd_profile *profile)
1146 {
1147         return;
1148 }
1149
1150 int dasd_profile_on(struct dasd_profile *profile)
1151 {
1152         return 0;
1153 }
1154
1155 #endif                          /* CONFIG_DASD_PROFILE */
1156
1157 static int dasd_hosts_show(struct seq_file *m, void *v)
1158 {
1159         struct dasd_device *device;
1160         int rc = -EOPNOTSUPP;
1161
1162         device = m->private;
1163         dasd_get_device(device);
1164
1165         if (device->discipline->hosts_print)
1166                 rc = device->discipline->hosts_print(device, m);
1167
1168         dasd_put_device(device);
1169         return rc;
1170 }
1171
1172 static int dasd_hosts_open(struct inode *inode, struct file *file)
1173 {
1174         struct dasd_device *device = inode->i_private;
1175
1176         return single_open(file, dasd_hosts_show, device);
1177 }
1178
1179 static const struct file_operations dasd_hosts_fops = {
1180         .owner          = THIS_MODULE,
1181         .open           = dasd_hosts_open,
1182         .read           = seq_read,
1183         .llseek         = seq_lseek,
1184         .release        = single_release,
1185 };
1186
1187 static void dasd_hosts_exit(struct dasd_device *device)
1188 {
1189         debugfs_remove(device->hosts_dentry);
1190         device->hosts_dentry = NULL;
1191 }
1192
1193 static void dasd_hosts_init(struct dentry *base_dentry,
1194                             struct dasd_device *device)
1195 {
1196         struct dentry *pde;
1197         umode_t mode;
1198
1199         if (!base_dentry)
1200                 return;
1201
1202         mode = S_IRUSR | S_IFREG;
1203         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1204                                   device, &dasd_hosts_fops);
1205         if (pde && !IS_ERR(pde))
1206                 device->hosts_dentry = pde;
1207 }
1208
1209 /*
1210  * Allocate memory for a channel program with 'cplength' channel
1211  * command words and 'datasize' additional space. There are two
1212  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1213  * memory and 2) dasd_smalloc_request uses the static ccw memory
1214  * that gets allocated for each device.
1215  */
1216 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1217                                           int datasize,
1218                                           struct dasd_device *device)
1219 {
1220         struct dasd_ccw_req *cqr;
1221
1222         /* Sanity checks */
1223         BUG_ON(datasize > PAGE_SIZE ||
1224              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1225
1226         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1227         if (cqr == NULL)
1228                 return ERR_PTR(-ENOMEM);
1229         cqr->cpaddr = NULL;
1230         if (cplength > 0) {
1231                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1232                                       GFP_ATOMIC | GFP_DMA);
1233                 if (cqr->cpaddr == NULL) {
1234                         kfree(cqr);
1235                         return ERR_PTR(-ENOMEM);
1236                 }
1237         }
1238         cqr->data = NULL;
1239         if (datasize > 0) {
1240                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1241                 if (cqr->data == NULL) {
1242                         kfree(cqr->cpaddr);
1243                         kfree(cqr);
1244                         return ERR_PTR(-ENOMEM);
1245                 }
1246         }
1247         cqr->magic =  magic;
1248         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1249         dasd_get_device(device);
1250         return cqr;
1251 }
1252 EXPORT_SYMBOL(dasd_kmalloc_request);
1253
1254 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1255                                           int datasize,
1256                                           struct dasd_device *device)
1257 {
1258         unsigned long flags;
1259         struct dasd_ccw_req *cqr;
1260         char *data;
1261         int size;
1262
1263         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1264         if (cplength > 0)
1265                 size += cplength * sizeof(struct ccw1);
1266         if (datasize > 0)
1267                 size += datasize;
1268         spin_lock_irqsave(&device->mem_lock, flags);
1269         cqr = (struct dasd_ccw_req *)
1270                 dasd_alloc_chunk(&device->ccw_chunks, size);
1271         spin_unlock_irqrestore(&device->mem_lock, flags);
1272         if (cqr == NULL)
1273                 return ERR_PTR(-ENOMEM);
1274         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1275         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1276         cqr->cpaddr = NULL;
1277         if (cplength > 0) {
1278                 cqr->cpaddr = (struct ccw1 *) data;
1279                 data += cplength*sizeof(struct ccw1);
1280                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1281         }
1282         cqr->data = NULL;
1283         if (datasize > 0) {
1284                 cqr->data = data;
1285                 memset(cqr->data, 0, datasize);
1286         }
1287         cqr->magic = magic;
1288         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1289         dasd_get_device(device);
1290         return cqr;
1291 }
1292 EXPORT_SYMBOL(dasd_smalloc_request);
1293
1294 /*
1295  * Free memory of a channel program. This function needs to free all the
1296  * idal lists that might have been created by dasd_set_cda and the
1297  * struct dasd_ccw_req itself.
1298  */
1299 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1300 {
1301         struct ccw1 *ccw;
1302
1303         /* Clear any idals used for the request. */
1304         ccw = cqr->cpaddr;
1305         do {
1306                 clear_normalized_cda(ccw);
1307         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1308         kfree(cqr->cpaddr);
1309         kfree(cqr->data);
1310         kfree(cqr);
1311         dasd_put_device(device);
1312 }
1313 EXPORT_SYMBOL(dasd_kfree_request);
1314
1315 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1316 {
1317         unsigned long flags;
1318
1319         spin_lock_irqsave(&device->mem_lock, flags);
1320         dasd_free_chunk(&device->ccw_chunks, cqr);
1321         spin_unlock_irqrestore(&device->mem_lock, flags);
1322         dasd_put_device(device);
1323 }
1324 EXPORT_SYMBOL(dasd_sfree_request);
1325
1326 /*
1327  * Check discipline magic in cqr.
1328  */
1329 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1330 {
1331         struct dasd_device *device;
1332
1333         if (cqr == NULL)
1334                 return -EINVAL;
1335         device = cqr->startdev;
1336         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1337                 DBF_DEV_EVENT(DBF_WARNING, device,
1338                             " dasd_ccw_req 0x%08x magic doesn't match"
1339                             " discipline 0x%08x",
1340                             cqr->magic,
1341                             *(unsigned int *) device->discipline->name);
1342                 return -EINVAL;
1343         }
1344         return 0;
1345 }
1346
1347 /*
1348  * Terminate the current i/o and set the request to clear_pending.
1349  * Timer keeps device runnig.
1350  * ccw_device_clear can fail if the i/o subsystem
1351  * is in a bad mood.
1352  */
1353 int dasd_term_IO(struct dasd_ccw_req *cqr)
1354 {
1355         struct dasd_device *device;
1356         int retries, rc;
1357         char errorstring[ERRORLENGTH];
1358
1359         /* Check the cqr */
1360         rc = dasd_check_cqr(cqr);
1361         if (rc)
1362                 return rc;
1363         retries = 0;
1364         device = (struct dasd_device *) cqr->startdev;
1365         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1366                 rc = ccw_device_clear(device->cdev, (long) cqr);
1367                 switch (rc) {
1368                 case 0: /* termination successful */
1369                         cqr->status = DASD_CQR_CLEAR_PENDING;
1370                         cqr->stopclk = get_tod_clock();
1371                         cqr->starttime = 0;
1372                         DBF_DEV_EVENT(DBF_DEBUG, device,
1373                                       "terminate cqr %p successful",
1374                                       cqr);
1375                         break;
1376                 case -ENODEV:
1377                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1378                                       "device gone, retry");
1379                         break;
1380                 case -EIO:
1381                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1382                                       "I/O error, retry");
1383                         break;
1384                 case -EINVAL:
1385                         /*
1386                          * device not valid so no I/O could be running
1387                          * handle CQR as termination successful
1388                          */
1389                         cqr->status = DASD_CQR_CLEARED;
1390                         cqr->stopclk = get_tod_clock();
1391                         cqr->starttime = 0;
1392                         /* no retries for invalid devices */
1393                         cqr->retries = -1;
1394                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1395                                       "EINVAL, handle as terminated");
1396                         /* fake rc to success */
1397                         rc = 0;
1398                         break;
1399                 case -EBUSY:
1400                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1401                                       "device busy, retry later");
1402                         break;
1403                 default:
1404                         /* internal error 10 - unknown rc*/
1405                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1406                         dev_err(&device->cdev->dev, "An error occurred in the "
1407                                 "DASD device driver, reason=%s\n", errorstring);
1408                         BUG();
1409                         break;
1410                 }
1411                 retries++;
1412         }
1413         dasd_schedule_device_bh(device);
1414         return rc;
1415 }
1416 EXPORT_SYMBOL(dasd_term_IO);
1417
1418 /*
1419  * Start the i/o. This start_IO can fail if the channel is really busy.
1420  * In that case set up a timer to start the request later.
1421  */
1422 int dasd_start_IO(struct dasd_ccw_req *cqr)
1423 {
1424         struct dasd_device *device;
1425         int rc;
1426         char errorstring[ERRORLENGTH];
1427
1428         /* Check the cqr */
1429         rc = dasd_check_cqr(cqr);
1430         if (rc) {
1431                 cqr->intrc = rc;
1432                 return rc;
1433         }
1434         device = (struct dasd_device *) cqr->startdev;
1435         if (((cqr->block &&
1436               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1437              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1438             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1439                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1440                               "because of stolen lock", cqr);
1441                 cqr->status = DASD_CQR_ERROR;
1442                 cqr->intrc = -EPERM;
1443                 return -EPERM;
1444         }
1445         if (cqr->retries < 0) {
1446                 /* internal error 14 - start_IO run out of retries */
1447                 sprintf(errorstring, "14 %p", cqr);
1448                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1449                         "device driver, reason=%s\n", errorstring);
1450                 cqr->status = DASD_CQR_ERROR;
1451                 return -EIO;
1452         }
1453         cqr->startclk = get_tod_clock();
1454         cqr->starttime = jiffies;
1455         cqr->retries--;
1456         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1457                 cqr->lpm &= device->path_data.opm;
1458                 if (!cqr->lpm)
1459                         cqr->lpm = device->path_data.opm;
1460         }
1461         if (cqr->cpmode == 1) {
1462                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1463                                          (long) cqr, cqr->lpm);
1464         } else {
1465                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1466                                       (long) cqr, cqr->lpm, 0);
1467         }
1468         switch (rc) {
1469         case 0:
1470                 cqr->status = DASD_CQR_IN_IO;
1471                 break;
1472         case -EBUSY:
1473                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1474                               "start_IO: device busy, retry later");
1475                 break;
1476         case -ETIMEDOUT:
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: request timeout, retry later");
1479                 break;
1480         case -EACCES:
1481                 /* -EACCES indicates that the request used only a subset of the
1482                  * available paths and all these paths are gone. If the lpm of
1483                  * this request was only a subset of the opm (e.g. the ppm) then
1484                  * we just do a retry with all available paths.
1485                  * If we already use the full opm, something is amiss, and we
1486                  * need a full path verification.
1487                  */
1488                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1489                         DBF_DEV_EVENT(DBF_WARNING, device,
1490                                       "start_IO: selected paths gone (%x)",
1491                                       cqr->lpm);
1492                 } else if (cqr->lpm != device->path_data.opm) {
1493                         cqr->lpm = device->path_data.opm;
1494                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1495                                       "start_IO: selected paths gone,"
1496                                       " retry on all paths");
1497                 } else {
1498                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1499                                       "start_IO: all paths in opm gone,"
1500                                       " do path verification");
1501                         dasd_generic_last_path_gone(device);
1502                         device->path_data.opm = 0;
1503                         device->path_data.ppm = 0;
1504                         device->path_data.npm = 0;
1505                         device->path_data.tbvpm =
1506                                 ccw_device_get_path_mask(device->cdev);
1507                 }
1508                 break;
1509         case -ENODEV:
1510                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1511                               "start_IO: -ENODEV device gone, retry");
1512                 break;
1513         case -EIO:
1514                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1515                               "start_IO: -EIO device gone, retry");
1516                 break;
1517         case -EINVAL:
1518                 /* most likely caused in power management context */
1519                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1520                               "start_IO: -EINVAL device currently "
1521                               "not accessible");
1522                 break;
1523         default:
1524                 /* internal error 11 - unknown rc */
1525                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1526                 dev_err(&device->cdev->dev,
1527                         "An error occurred in the DASD device driver, "
1528                         "reason=%s\n", errorstring);
1529                 BUG();
1530                 break;
1531         }
1532         cqr->intrc = rc;
1533         return rc;
1534 }
1535 EXPORT_SYMBOL(dasd_start_IO);
1536
1537 /*
1538  * Timeout function for dasd devices. This is used for different purposes
1539  *  1) missing interrupt handler for normal operation
1540  *  2) delayed start of request where start_IO failed with -EBUSY
1541  *  3) timeout for missing state change interrupts
1542  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1543  * DASD_CQR_QUEUED for 2) and 3).
1544  */
1545 static void dasd_device_timeout(unsigned long ptr)
1546 {
1547         unsigned long flags;
1548         struct dasd_device *device;
1549
1550         device = (struct dasd_device *) ptr;
1551         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1552         /* re-activate request queue */
1553         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1554         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1555         dasd_schedule_device_bh(device);
1556 }
1557
1558 /*
1559  * Setup timeout for a device in jiffies.
1560  */
1561 void dasd_device_set_timer(struct dasd_device *device, int expires)
1562 {
1563         if (expires == 0)
1564                 del_timer(&device->timer);
1565         else
1566                 mod_timer(&device->timer, jiffies + expires);
1567 }
1568 EXPORT_SYMBOL(dasd_device_set_timer);
1569
1570 /*
1571  * Clear timeout for a device.
1572  */
1573 void dasd_device_clear_timer(struct dasd_device *device)
1574 {
1575         del_timer(&device->timer);
1576 }
1577 EXPORT_SYMBOL(dasd_device_clear_timer);
1578
1579 static void dasd_handle_killed_request(struct ccw_device *cdev,
1580                                        unsigned long intparm)
1581 {
1582         struct dasd_ccw_req *cqr;
1583         struct dasd_device *device;
1584
1585         if (!intparm)
1586                 return;
1587         cqr = (struct dasd_ccw_req *) intparm;
1588         if (cqr->status != DASD_CQR_IN_IO) {
1589                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1590                                 "invalid status in handle_killed_request: "
1591                                 "%02x", cqr->status);
1592                 return;
1593         }
1594
1595         device = dasd_device_from_cdev_locked(cdev);
1596         if (IS_ERR(device)) {
1597                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1598                                 "unable to get device from cdev");
1599                 return;
1600         }
1601
1602         if (!cqr->startdev ||
1603             device != cqr->startdev ||
1604             strncmp(cqr->startdev->discipline->ebcname,
1605                     (char *) &cqr->magic, 4)) {
1606                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1607                                 "invalid device in request");
1608                 dasd_put_device(device);
1609                 return;
1610         }
1611
1612         /* Schedule request to be retried. */
1613         cqr->status = DASD_CQR_QUEUED;
1614
1615         dasd_device_clear_timer(device);
1616         dasd_schedule_device_bh(device);
1617         dasd_put_device(device);
1618 }
1619
1620 void dasd_generic_handle_state_change(struct dasd_device *device)
1621 {
1622         /* First of all start sense subsystem status request. */
1623         dasd_eer_snss(device);
1624
1625         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1626         dasd_schedule_device_bh(device);
1627         if (device->block)
1628                 dasd_schedule_block_bh(device->block);
1629 }
1630 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1631
1632 /*
1633  * Interrupt handler for "normal" ssch-io based dasd devices.
1634  */
1635 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1636                       struct irb *irb)
1637 {
1638         struct dasd_ccw_req *cqr, *next;
1639         struct dasd_device *device;
1640         unsigned long long now;
1641         int nrf_suppressed = 0;
1642         int fp_suppressed = 0;
1643         u8 *sense = NULL;
1644         int expires;
1645
1646         if (IS_ERR(irb)) {
1647                 switch (PTR_ERR(irb)) {
1648                 case -EIO:
1649                         break;
1650                 case -ETIMEDOUT:
1651                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1652                                         "request timed out\n", __func__);
1653                         break;
1654                 default:
1655                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1656                                         "unknown error %ld\n", __func__,
1657                                         PTR_ERR(irb));
1658                 }
1659                 dasd_handle_killed_request(cdev, intparm);
1660                 return;
1661         }
1662
1663         now = get_tod_clock();
1664         cqr = (struct dasd_ccw_req *) intparm;
1665         /* check for conditions that should be handled immediately */
1666         if (!cqr ||
1667             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1668               scsw_cstat(&irb->scsw) == 0)) {
1669                 if (cqr)
1670                         memcpy(&cqr->irb, irb, sizeof(*irb));
1671                 device = dasd_device_from_cdev_locked(cdev);
1672                 if (IS_ERR(device))
1673                         return;
1674                 /* ignore unsolicited interrupts for DIAG discipline */
1675                 if (device->discipline == dasd_diag_discipline_pointer) {
1676                         dasd_put_device(device);
1677                         return;
1678                 }
1679
1680                 /*
1681                  * In some cases 'File Protected' or 'No Record Found' errors
1682                  * might be expected and debug log messages for the
1683                  * corresponding interrupts shouldn't be written then.
1684                  * Check if either of the according suppress bits is set.
1685                  */
1686                 sense = dasd_get_sense(irb);
1687                 if (sense) {
1688                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1689                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1690                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1691                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1692                 }
1693                 if (!(fp_suppressed || nrf_suppressed))
1694                         device->discipline->dump_sense_dbf(device, irb, "int");
1695
1696                 if (device->features & DASD_FEATURE_ERPLOG)
1697                         device->discipline->dump_sense(device, cqr, irb);
1698                 device->discipline->check_for_device_change(device, cqr, irb);
1699                 dasd_put_device(device);
1700         }
1701
1702         /* check for for attention message */
1703         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1704                 device = dasd_device_from_cdev_locked(cdev);
1705                 device->discipline->check_attention(device, irb->esw.esw1.lpum);
1706                 dasd_put_device(device);
1707         }
1708
1709         if (!cqr)
1710                 return;
1711
1712         device = (struct dasd_device *) cqr->startdev;
1713         if (!device ||
1714             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1715                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1716                                 "invalid device in request");
1717                 return;
1718         }
1719
1720         /* Check for clear pending */
1721         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1722             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1723                 cqr->status = DASD_CQR_CLEARED;
1724                 dasd_device_clear_timer(device);
1725                 wake_up(&dasd_flush_wq);
1726                 dasd_schedule_device_bh(device);
1727                 return;
1728         }
1729
1730         /* check status - the request might have been killed by dyn detach */
1731         if (cqr->status != DASD_CQR_IN_IO) {
1732                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1733                               "status %02x", dev_name(&cdev->dev), cqr->status);
1734                 return;
1735         }
1736
1737         next = NULL;
1738         expires = 0;
1739         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1740             scsw_cstat(&irb->scsw) == 0) {
1741                 /* request was completed successfully */
1742                 cqr->status = DASD_CQR_SUCCESS;
1743                 cqr->stopclk = now;
1744                 /* Start first request on queue if possible -> fast_io. */
1745                 if (cqr->devlist.next != &device->ccw_queue) {
1746                         next = list_entry(cqr->devlist.next,
1747                                           struct dasd_ccw_req, devlist);
1748                 }
1749         } else {  /* error */
1750                 /*
1751                  * If we don't want complex ERP for this request, then just
1752                  * reset this and retry it in the fastpath
1753                  */
1754                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1755                     cqr->retries > 0) {
1756                         if (cqr->lpm == device->path_data.opm)
1757                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1758                                               "default ERP in fastpath "
1759                                               "(%i retries left)",
1760                                               cqr->retries);
1761                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1762                                 cqr->lpm = device->path_data.opm;
1763                         cqr->status = DASD_CQR_QUEUED;
1764                         next = cqr;
1765                 } else
1766                         cqr->status = DASD_CQR_ERROR;
1767         }
1768         if (next && (next->status == DASD_CQR_QUEUED) &&
1769             (!device->stopped)) {
1770                 if (device->discipline->start_IO(next) == 0)
1771                         expires = next->expires;
1772         }
1773         if (expires != 0)
1774                 dasd_device_set_timer(device, expires);
1775         else
1776                 dasd_device_clear_timer(device);
1777         dasd_schedule_device_bh(device);
1778 }
1779 EXPORT_SYMBOL(dasd_int_handler);
1780
1781 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1782 {
1783         struct dasd_device *device;
1784
1785         device = dasd_device_from_cdev_locked(cdev);
1786
1787         if (IS_ERR(device))
1788                 goto out;
1789         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1790            device->state != device->target ||
1791            !device->discipline->check_for_device_change){
1792                 dasd_put_device(device);
1793                 goto out;
1794         }
1795         if (device->discipline->dump_sense_dbf)
1796                 device->discipline->dump_sense_dbf(device, irb, "uc");
1797         device->discipline->check_for_device_change(device, NULL, irb);
1798         dasd_put_device(device);
1799 out:
1800         return UC_TODO_RETRY;
1801 }
1802 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1803
1804 /*
1805  * If we have an error on a dasd_block layer request then we cancel
1806  * and return all further requests from the same dasd_block as well.
1807  */
1808 static void __dasd_device_recovery(struct dasd_device *device,
1809                                    struct dasd_ccw_req *ref_cqr)
1810 {
1811         struct list_head *l, *n;
1812         struct dasd_ccw_req *cqr;
1813
1814         /*
1815          * only requeue request that came from the dasd_block layer
1816          */
1817         if (!ref_cqr->block)
1818                 return;
1819
1820         list_for_each_safe(l, n, &device->ccw_queue) {
1821                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1822                 if (cqr->status == DASD_CQR_QUEUED &&
1823                     ref_cqr->block == cqr->block) {
1824                         cqr->status = DASD_CQR_CLEARED;
1825                 }
1826         }
1827 };
1828
1829 /*
1830  * Remove those ccw requests from the queue that need to be returned
1831  * to the upper layer.
1832  */
1833 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1834                                             struct list_head *final_queue)
1835 {
1836         struct list_head *l, *n;
1837         struct dasd_ccw_req *cqr;
1838
1839         /* Process request with final status. */
1840         list_for_each_safe(l, n, &device->ccw_queue) {
1841                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1842
1843                 /* Skip any non-final request. */
1844                 if (cqr->status == DASD_CQR_QUEUED ||
1845                     cqr->status == DASD_CQR_IN_IO ||
1846                     cqr->status == DASD_CQR_CLEAR_PENDING)
1847                         continue;
1848                 if (cqr->status == DASD_CQR_ERROR) {
1849                         __dasd_device_recovery(device, cqr);
1850                 }
1851                 /* Rechain finished requests to final queue */
1852                 list_move_tail(&cqr->devlist, final_queue);
1853         }
1854 }
1855
1856 /*
1857  * the cqrs from the final queue are returned to the upper layer
1858  * by setting a dasd_block state and calling the callback function
1859  */
1860 static void __dasd_device_process_final_queue(struct dasd_device *device,
1861                                               struct list_head *final_queue)
1862 {
1863         struct list_head *l, *n;
1864         struct dasd_ccw_req *cqr;
1865         struct dasd_block *block;
1866         void (*callback)(struct dasd_ccw_req *, void *data);
1867         void *callback_data;
1868         char errorstring[ERRORLENGTH];
1869
1870         list_for_each_safe(l, n, final_queue) {
1871                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1872                 list_del_init(&cqr->devlist);
1873                 block = cqr->block;
1874                 callback = cqr->callback;
1875                 callback_data = cqr->callback_data;
1876                 if (block)
1877                         spin_lock_bh(&block->queue_lock);
1878                 switch (cqr->status) {
1879                 case DASD_CQR_SUCCESS:
1880                         cqr->status = DASD_CQR_DONE;
1881                         break;
1882                 case DASD_CQR_ERROR:
1883                         cqr->status = DASD_CQR_NEED_ERP;
1884                         break;
1885                 case DASD_CQR_CLEARED:
1886                         cqr->status = DASD_CQR_TERMINATED;
1887                         break;
1888                 default:
1889                         /* internal error 12 - wrong cqr status*/
1890                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1891                         dev_err(&device->cdev->dev,
1892                                 "An error occurred in the DASD device driver, "
1893                                 "reason=%s\n", errorstring);
1894                         BUG();
1895                 }
1896                 if (cqr->callback != NULL)
1897                         (callback)(cqr, callback_data);
1898                 if (block)
1899                         spin_unlock_bh(&block->queue_lock);
1900         }
1901 }
1902
1903 /*
1904  * Take a look at the first request on the ccw queue and check
1905  * if it reached its expire time. If so, terminate the IO.
1906  */
1907 static void __dasd_device_check_expire(struct dasd_device *device)
1908 {
1909         struct dasd_ccw_req *cqr;
1910
1911         if (list_empty(&device->ccw_queue))
1912                 return;
1913         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1914         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1915             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1916                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1917                         /*
1918                          * IO in safe offline processing should not
1919                          * run out of retries
1920                          */
1921                         cqr->retries++;
1922                 }
1923                 if (device->discipline->term_IO(cqr) != 0) {
1924                         /* Hmpf, try again in 5 sec */
1925                         dev_err(&device->cdev->dev,
1926                                 "cqr %p timed out (%lus) but cannot be "
1927                                 "ended, retrying in 5 s\n",
1928                                 cqr, (cqr->expires/HZ));
1929                         cqr->expires += 5*HZ;
1930                         dasd_device_set_timer(device, 5*HZ);
1931                 } else {
1932                         dev_err(&device->cdev->dev,
1933                                 "cqr %p timed out (%lus), %i retries "
1934                                 "remaining\n", cqr, (cqr->expires/HZ),
1935                                 cqr->retries);
1936                 }
1937         }
1938 }
1939
1940 /*
1941  * return 1 when device is not eligible for IO
1942  */
1943 static int __dasd_device_is_unusable(struct dasd_device *device,
1944                                      struct dasd_ccw_req *cqr)
1945 {
1946         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1947
1948         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1949                 /* dasd is being set offline. */
1950                 return 1;
1951         }
1952         if (device->stopped) {
1953                 if (device->stopped & mask) {
1954                         /* stopped and CQR will not change that. */
1955                         return 1;
1956                 }
1957                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1958                         /* CQR is not able to change device to
1959                          * operational. */
1960                         return 1;
1961                 }
1962                 /* CQR required to get device operational. */
1963         }
1964         return 0;
1965 }
1966
1967 /*
1968  * Take a look at the first request on the ccw queue and check
1969  * if it needs to be started.
1970  */
1971 static void __dasd_device_start_head(struct dasd_device *device)
1972 {
1973         struct dasd_ccw_req *cqr;
1974         int rc;
1975
1976         if (list_empty(&device->ccw_queue))
1977                 return;
1978         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1979         if (cqr->status != DASD_CQR_QUEUED)
1980                 return;
1981         /* if device is not usable return request to upper layer */
1982         if (__dasd_device_is_unusable(device, cqr)) {
1983                 cqr->intrc = -EAGAIN;
1984                 cqr->status = DASD_CQR_CLEARED;
1985                 dasd_schedule_device_bh(device);
1986                 return;
1987         }
1988
1989         rc = device->discipline->start_IO(cqr);
1990         if (rc == 0)
1991                 dasd_device_set_timer(device, cqr->expires);
1992         else if (rc == -EACCES) {
1993                 dasd_schedule_device_bh(device);
1994         } else
1995                 /* Hmpf, try again in 1/2 sec */
1996                 dasd_device_set_timer(device, 50);
1997 }
1998
1999 static void __dasd_device_check_path_events(struct dasd_device *device)
2000 {
2001         int rc;
2002
2003         if (device->path_data.tbvpm) {
2004                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
2005                                         DASD_UNRESUMED_PM))
2006                         return;
2007                 rc = device->discipline->verify_path(
2008                         device, device->path_data.tbvpm);
2009                 if (rc)
2010                         dasd_device_set_timer(device, 50);
2011                 else
2012                         device->path_data.tbvpm = 0;
2013         }
2014 };
2015
2016 /*
2017  * Go through all request on the dasd_device request queue,
2018  * terminate them on the cdev if necessary, and return them to the
2019  * submitting layer via callback.
2020  * Note:
2021  * Make sure that all 'submitting layers' still exist when
2022  * this function is called!. In other words, when 'device' is a base
2023  * device then all block layer requests must have been removed before
2024  * via dasd_flush_block_queue.
2025  */
2026 int dasd_flush_device_queue(struct dasd_device *device)
2027 {
2028         struct dasd_ccw_req *cqr, *n;
2029         int rc;
2030         struct list_head flush_queue;
2031
2032         INIT_LIST_HEAD(&flush_queue);
2033         spin_lock_irq(get_ccwdev_lock(device->cdev));
2034         rc = 0;
2035         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2036                 /* Check status and move request to flush_queue */
2037                 switch (cqr->status) {
2038                 case DASD_CQR_IN_IO:
2039                         rc = device->discipline->term_IO(cqr);
2040                         if (rc) {
2041                                 /* unable to terminate requeust */
2042                                 dev_err(&device->cdev->dev,
2043                                         "Flushing the DASD request queue "
2044                                         "failed for request %p\n", cqr);
2045                                 /* stop flush processing */
2046                                 goto finished;
2047                         }
2048                         break;
2049                 case DASD_CQR_QUEUED:
2050                         cqr->stopclk = get_tod_clock();
2051                         cqr->status = DASD_CQR_CLEARED;
2052                         break;
2053                 default: /* no need to modify the others */
2054                         break;
2055                 }
2056                 list_move_tail(&cqr->devlist, &flush_queue);
2057         }
2058 finished:
2059         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2060         /*
2061          * After this point all requests must be in state CLEAR_PENDING,
2062          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2063          * one of the others.
2064          */
2065         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2066                 wait_event(dasd_flush_wq,
2067                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2068         /*
2069          * Now set each request back to TERMINATED, DONE or NEED_ERP
2070          * and call the callback function of flushed requests
2071          */
2072         __dasd_device_process_final_queue(device, &flush_queue);
2073         return rc;
2074 }
2075 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2076
2077 /*
2078  * Acquire the device lock and process queues for the device.
2079  */
2080 static void dasd_device_tasklet(struct dasd_device *device)
2081 {
2082         struct list_head final_queue;
2083
2084         atomic_set (&device->tasklet_scheduled, 0);
2085         INIT_LIST_HEAD(&final_queue);
2086         spin_lock_irq(get_ccwdev_lock(device->cdev));
2087         /* Check expire time of first request on the ccw queue. */
2088         __dasd_device_check_expire(device);
2089         /* find final requests on ccw queue */
2090         __dasd_device_process_ccw_queue(device, &final_queue);
2091         __dasd_device_check_path_events(device);
2092         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2093         /* Now call the callback function of requests with final status */
2094         __dasd_device_process_final_queue(device, &final_queue);
2095         spin_lock_irq(get_ccwdev_lock(device->cdev));
2096         /* Now check if the head of the ccw queue needs to be started. */
2097         __dasd_device_start_head(device);
2098         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2099         if (waitqueue_active(&shutdown_waitq))
2100                 wake_up(&shutdown_waitq);
2101         dasd_put_device(device);
2102 }
2103
2104 /*
2105  * Schedules a call to dasd_tasklet over the device tasklet.
2106  */
2107 void dasd_schedule_device_bh(struct dasd_device *device)
2108 {
2109         /* Protect against rescheduling. */
2110         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2111                 return;
2112         dasd_get_device(device);
2113         tasklet_hi_schedule(&device->tasklet);
2114 }
2115 EXPORT_SYMBOL(dasd_schedule_device_bh);
2116
2117 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2118 {
2119         device->stopped |= bits;
2120 }
2121 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2122
2123 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2124 {
2125         device->stopped &= ~bits;
2126         if (!device->stopped)
2127                 wake_up(&generic_waitq);
2128 }
2129 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2130
2131 /*
2132  * Queue a request to the head of the device ccw_queue.
2133  * Start the I/O if possible.
2134  */
2135 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2136 {
2137         struct dasd_device *device;
2138         unsigned long flags;
2139
2140         device = cqr->startdev;
2141         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2142         cqr->status = DASD_CQR_QUEUED;
2143         list_add(&cqr->devlist, &device->ccw_queue);
2144         /* let the bh start the request to keep them in order */
2145         dasd_schedule_device_bh(device);
2146         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2147 }
2148 EXPORT_SYMBOL(dasd_add_request_head);
2149
2150 /*
2151  * Queue a request to the tail of the device ccw_queue.
2152  * Start the I/O if possible.
2153  */
2154 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2155 {
2156         struct dasd_device *device;
2157         unsigned long flags;
2158
2159         device = cqr->startdev;
2160         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2161         cqr->status = DASD_CQR_QUEUED;
2162         list_add_tail(&cqr->devlist, &device->ccw_queue);
2163         /* let the bh start the request to keep them in order */
2164         dasd_schedule_device_bh(device);
2165         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2166 }
2167 EXPORT_SYMBOL(dasd_add_request_tail);
2168
2169 /*
2170  * Wakeup helper for the 'sleep_on' functions.
2171  */
2172 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2173 {
2174         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2175         cqr->callback_data = DASD_SLEEPON_END_TAG;
2176         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2177         wake_up(&generic_waitq);
2178 }
2179 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2180
2181 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2182 {
2183         struct dasd_device *device;
2184         int rc;
2185
2186         device = cqr->startdev;
2187         spin_lock_irq(get_ccwdev_lock(device->cdev));
2188         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2189         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2190         return rc;
2191 }
2192
2193 /*
2194  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2195  */
2196 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2197 {
2198         struct dasd_device *device;
2199         dasd_erp_fn_t erp_fn;
2200
2201         if (cqr->status == DASD_CQR_FILLED)
2202                 return 0;
2203         device = cqr->startdev;
2204         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2205                 if (cqr->status == DASD_CQR_TERMINATED) {
2206                         device->discipline->handle_terminated_request(cqr);
2207                         return 1;
2208                 }
2209                 if (cqr->status == DASD_CQR_NEED_ERP) {
2210                         erp_fn = device->discipline->erp_action(cqr);
2211                         erp_fn(cqr);
2212                         return 1;
2213                 }
2214                 if (cqr->status == DASD_CQR_FAILED)
2215                         dasd_log_sense(cqr, &cqr->irb);
2216                 if (cqr->refers) {
2217                         __dasd_process_erp(device, cqr);
2218                         return 1;
2219                 }
2220         }
2221         return 0;
2222 }
2223
2224 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2225 {
2226         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2227                 if (cqr->refers) /* erp is not done yet */
2228                         return 1;
2229                 return ((cqr->status != DASD_CQR_DONE) &&
2230                         (cqr->status != DASD_CQR_FAILED));
2231         } else
2232                 return (cqr->status == DASD_CQR_FILLED);
2233 }
2234
2235 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2236 {
2237         struct dasd_device *device;
2238         int rc;
2239         struct list_head ccw_queue;
2240         struct dasd_ccw_req *cqr;
2241
2242         INIT_LIST_HEAD(&ccw_queue);
2243         maincqr->status = DASD_CQR_FILLED;
2244         device = maincqr->startdev;
2245         list_add(&maincqr->blocklist, &ccw_queue);
2246         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2247              cqr = list_first_entry(&ccw_queue,
2248                                     struct dasd_ccw_req, blocklist)) {
2249
2250                 if (__dasd_sleep_on_erp(cqr))
2251                         continue;
2252                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2253                         continue;
2254                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2255                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2256                         cqr->status = DASD_CQR_FAILED;
2257                         cqr->intrc = -EPERM;
2258                         continue;
2259                 }
2260                 /* Non-temporary stop condition will trigger fail fast */
2261                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2262                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2263                     (!dasd_eer_enabled(device))) {
2264                         cqr->status = DASD_CQR_FAILED;
2265                         cqr->intrc = -ENOLINK;
2266                         continue;
2267                 }
2268                 /*
2269                  * Don't try to start requests if device is stopped
2270                  * except path verification requests
2271                  */
2272                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2273                         if (interruptible) {
2274                                 rc = wait_event_interruptible(
2275                                         generic_waitq, !(device->stopped));
2276                                 if (rc == -ERESTARTSYS) {
2277                                         cqr->status = DASD_CQR_FAILED;
2278                                         maincqr->intrc = rc;
2279                                         continue;
2280                                 }
2281                         } else
2282                                 wait_event(generic_waitq, !(device->stopped));
2283                 }
2284                 if (!cqr->callback)
2285                         cqr->callback = dasd_wakeup_cb;
2286
2287                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2288                 dasd_add_request_tail(cqr);
2289                 if (interruptible) {
2290                         rc = wait_event_interruptible(
2291                                 generic_waitq, _wait_for_wakeup(cqr));
2292                         if (rc == -ERESTARTSYS) {
2293                                 dasd_cancel_req(cqr);
2294                                 /* wait (non-interruptible) for final status */
2295                                 wait_event(generic_waitq,
2296                                            _wait_for_wakeup(cqr));
2297                                 cqr->status = DASD_CQR_FAILED;
2298                                 maincqr->intrc = rc;
2299                                 continue;
2300                         }
2301                 } else
2302                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2303         }
2304
2305         maincqr->endclk = get_tod_clock();
2306         if ((maincqr->status != DASD_CQR_DONE) &&
2307             (maincqr->intrc != -ERESTARTSYS))
2308                 dasd_log_sense(maincqr, &maincqr->irb);
2309         if (maincqr->status == DASD_CQR_DONE)
2310                 rc = 0;
2311         else if (maincqr->intrc)
2312                 rc = maincqr->intrc;
2313         else
2314                 rc = -EIO;
2315         return rc;
2316 }
2317
2318 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2319 {
2320         struct dasd_ccw_req *cqr;
2321
2322         list_for_each_entry(cqr, ccw_queue, blocklist) {
2323                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2324                         return 0;
2325         }
2326
2327         return 1;
2328 }
2329
2330 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2331 {
2332         struct dasd_device *device;
2333         struct dasd_ccw_req *cqr, *n;
2334         u8 *sense = NULL;
2335         int rc;
2336
2337 retry:
2338         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2339                 device = cqr->startdev;
2340                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2341                         continue;
2342
2343                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2344                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2345                         cqr->status = DASD_CQR_FAILED;
2346                         cqr->intrc = -EPERM;
2347                         continue;
2348                 }
2349                 /*Non-temporary stop condition will trigger fail fast*/
2350                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2351                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2352                     !dasd_eer_enabled(device)) {
2353                         cqr->status = DASD_CQR_FAILED;
2354                         cqr->intrc = -EAGAIN;
2355                         continue;
2356                 }
2357
2358                 /*Don't try to start requests if device is stopped*/
2359                 if (interruptible) {
2360                         rc = wait_event_interruptible(
2361                                 generic_waitq, !device->stopped);
2362                         if (rc == -ERESTARTSYS) {
2363                                 cqr->status = DASD_CQR_FAILED;
2364                                 cqr->intrc = rc;
2365                                 continue;
2366                         }
2367                 } else
2368                         wait_event(generic_waitq, !(device->stopped));
2369
2370                 if (!cqr->callback)
2371                         cqr->callback = dasd_wakeup_cb;
2372                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2373                 dasd_add_request_tail(cqr);
2374         }
2375
2376         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2377
2378         rc = 0;
2379         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2380                 /*
2381                  * In some cases the 'File Protected' or 'Incorrect Length'
2382                  * error might be expected and error recovery would be
2383                  * unnecessary in these cases.  Check if the according suppress
2384                  * bit is set.
2385                  */
2386                 sense = dasd_get_sense(&cqr->irb);
2387                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2388                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2389                         continue;
2390                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2391                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2392                         continue;
2393
2394                 /*
2395                  * for alias devices simplify error recovery and
2396                  * return to upper layer
2397                  * do not skip ERP requests
2398                  */
2399                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2400                     (cqr->status == DASD_CQR_TERMINATED ||
2401                      cqr->status == DASD_CQR_NEED_ERP))
2402                         return -EAGAIN;
2403
2404                 /* normal recovery for basedev IO */
2405                 if (__dasd_sleep_on_erp(cqr))
2406                         /* handle erp first */
2407                         goto retry;
2408         }
2409
2410         return 0;
2411 }
2412
2413 /*
2414  * Queue a request to the tail of the device ccw_queue and wait for
2415  * it's completion.
2416  */
2417 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2418 {
2419         return _dasd_sleep_on(cqr, 0);
2420 }
2421 EXPORT_SYMBOL(dasd_sleep_on);
2422
2423 /*
2424  * Start requests from a ccw_queue and wait for their completion.
2425  */
2426 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2427 {
2428         return _dasd_sleep_on_queue(ccw_queue, 0);
2429 }
2430 EXPORT_SYMBOL(dasd_sleep_on_queue);
2431
2432 /*
2433  * Queue a request to the tail of the device ccw_queue and wait
2434  * interruptible for it's completion.
2435  */
2436 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2437 {
2438         return _dasd_sleep_on(cqr, 1);
2439 }
2440 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2441
2442 /*
2443  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2444  * for eckd devices) the currently running request has to be terminated
2445  * and be put back to status queued, before the special request is added
2446  * to the head of the queue. Then the special request is waited on normally.
2447  */
2448 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2449 {
2450         struct dasd_ccw_req *cqr;
2451         int rc;
2452
2453         if (list_empty(&device->ccw_queue))
2454                 return 0;
2455         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2456         rc = device->discipline->term_IO(cqr);
2457         if (!rc)
2458                 /*
2459                  * CQR terminated because a more important request is pending.
2460                  * Undo decreasing of retry counter because this is
2461                  * not an error case.
2462                  */
2463                 cqr->retries++;
2464         return rc;
2465 }
2466
2467 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2468 {
2469         struct dasd_device *device;
2470         int rc;
2471
2472         device = cqr->startdev;
2473         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2474             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2475                 cqr->status = DASD_CQR_FAILED;
2476                 cqr->intrc = -EPERM;
2477                 return -EIO;
2478         }
2479         spin_lock_irq(get_ccwdev_lock(device->cdev));
2480         rc = _dasd_term_running_cqr(device);
2481         if (rc) {
2482                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2483                 return rc;
2484         }
2485         cqr->callback = dasd_wakeup_cb;
2486         cqr->callback_data = DASD_SLEEPON_START_TAG;
2487         cqr->status = DASD_CQR_QUEUED;
2488         /*
2489          * add new request as second
2490          * first the terminated cqr needs to be finished
2491          */
2492         list_add(&cqr->devlist, device->ccw_queue.next);
2493
2494         /* let the bh start the request to keep them in order */
2495         dasd_schedule_device_bh(device);
2496
2497         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2498
2499         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2500
2501         if (cqr->status == DASD_CQR_DONE)
2502                 rc = 0;
2503         else if (cqr->intrc)
2504                 rc = cqr->intrc;
2505         else
2506                 rc = -EIO;
2507
2508         /* kick tasklets */
2509         dasd_schedule_device_bh(device);
2510         if (device->block)
2511                 dasd_schedule_block_bh(device->block);
2512
2513         return rc;
2514 }
2515 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2516
2517 /*
2518  * Cancels a request that was started with dasd_sleep_on_req.
2519  * This is useful to timeout requests. The request will be
2520  * terminated if it is currently in i/o.
2521  * Returns 0 if request termination was successful
2522  *         negative error code if termination failed
2523  * Cancellation of a request is an asynchronous operation! The calling
2524  * function has to wait until the request is properly returned via callback.
2525  */
2526 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2527 {
2528         struct dasd_device *device = cqr->startdev;
2529         unsigned long flags;
2530         int rc;
2531
2532         rc = 0;
2533         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2534         switch (cqr->status) {
2535         case DASD_CQR_QUEUED:
2536                 /* request was not started - just set to cleared */
2537                 cqr->status = DASD_CQR_CLEARED;
2538                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2539                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2540                 break;
2541         case DASD_CQR_IN_IO:
2542                 /* request in IO - terminate IO and release again */
2543                 rc = device->discipline->term_IO(cqr);
2544                 if (rc) {
2545                         dev_err(&device->cdev->dev,
2546                                 "Cancelling request %p failed with rc=%d\n",
2547                                 cqr, rc);
2548                 } else {
2549                         cqr->stopclk = get_tod_clock();
2550                 }
2551                 break;
2552         default: /* already finished or clear pending - do nothing */
2553                 break;
2554         }
2555         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2556         dasd_schedule_device_bh(device);
2557         return rc;
2558 }
2559 EXPORT_SYMBOL(dasd_cancel_req);
2560
2561 /*
2562  * SECTION: Operations of the dasd_block layer.
2563  */
2564
2565 /*
2566  * Timeout function for dasd_block. This is used when the block layer
2567  * is waiting for something that may not come reliably, (e.g. a state
2568  * change interrupt)
2569  */
2570 static void dasd_block_timeout(unsigned long ptr)
2571 {
2572         unsigned long flags;
2573         struct dasd_block *block;
2574
2575         block = (struct dasd_block *) ptr;
2576         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2577         /* re-activate request queue */
2578         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2579         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2580         dasd_schedule_block_bh(block);
2581 }
2582
2583 /*
2584  * Setup timeout for a dasd_block in jiffies.
2585  */
2586 void dasd_block_set_timer(struct dasd_block *block, int expires)
2587 {
2588         if (expires == 0)
2589                 del_timer(&block->timer);
2590         else
2591                 mod_timer(&block->timer, jiffies + expires);
2592 }
2593 EXPORT_SYMBOL(dasd_block_set_timer);
2594
2595 /*
2596  * Clear timeout for a dasd_block.
2597  */
2598 void dasd_block_clear_timer(struct dasd_block *block)
2599 {
2600         del_timer(&block->timer);
2601 }
2602 EXPORT_SYMBOL(dasd_block_clear_timer);
2603
2604 /*
2605  * Process finished error recovery ccw.
2606  */
2607 static void __dasd_process_erp(struct dasd_device *device,
2608                                struct dasd_ccw_req *cqr)
2609 {
2610         dasd_erp_fn_t erp_fn;
2611
2612         if (cqr->status == DASD_CQR_DONE)
2613                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2614         else
2615                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2616         erp_fn = device->discipline->erp_postaction(cqr);
2617         erp_fn(cqr);
2618 }
2619
2620 /*
2621  * Fetch requests from the block device queue.
2622  */
2623 static void __dasd_process_request_queue(struct dasd_block *block)
2624 {
2625         struct request_queue *queue;
2626         struct request *req;
2627         struct dasd_ccw_req *cqr;
2628         struct dasd_device *basedev;
2629         unsigned long flags;
2630         queue = block->request_queue;
2631         basedev = block->base;
2632         /* No queue ? Then there is nothing to do. */
2633         if (queue == NULL)
2634                 return;
2635
2636         /*
2637          * We requeue request from the block device queue to the ccw
2638          * queue only in two states. In state DASD_STATE_READY the
2639          * partition detection is done and we need to requeue requests
2640          * for that. State DASD_STATE_ONLINE is normal block device
2641          * operation.
2642          */
2643         if (basedev->state < DASD_STATE_READY) {
2644                 while ((req = blk_fetch_request(block->request_queue)))
2645                         __blk_end_request_all(req, -EIO);
2646                 return;
2647         }
2648
2649         /*
2650          * if device is stopped do not fetch new requests
2651          * except failfast is active which will let requests fail
2652          * immediately in __dasd_block_start_head()
2653          */
2654         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST))
2655                 return;
2656
2657         /* Now we try to fetch requests from the request queue */
2658         while ((req = blk_peek_request(queue))) {
2659                 if (basedev->features & DASD_FEATURE_READONLY &&
2660                     rq_data_dir(req) == WRITE) {
2661                         DBF_DEV_EVENT(DBF_ERR, basedev,
2662                                       "Rejecting write request %p",
2663                                       req);
2664                         blk_start_request(req);
2665                         __blk_end_request_all(req, -EIO);
2666                         continue;
2667                 }
2668                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2669                     (basedev->features & DASD_FEATURE_FAILFAST ||
2670                      blk_noretry_request(req))) {
2671                         DBF_DEV_EVENT(DBF_ERR, basedev,
2672                                       "Rejecting failfast request %p",
2673                                       req);
2674                         blk_start_request(req);
2675                         __blk_end_request_all(req, -ETIMEDOUT);
2676                         continue;
2677                 }
2678                 cqr = basedev->discipline->build_cp(basedev, block, req);
2679                 if (IS_ERR(cqr)) {
2680                         if (PTR_ERR(cqr) == -EBUSY)
2681                                 break;  /* normal end condition */
2682                         if (PTR_ERR(cqr) == -ENOMEM)
2683                                 break;  /* terminate request queue loop */
2684                         if (PTR_ERR(cqr) == -EAGAIN) {
2685                                 /*
2686                                  * The current request cannot be build right
2687                                  * now, we have to try later. If this request
2688                                  * is the head-of-queue we stop the device
2689                                  * for 1/2 second.
2690                                  */
2691                                 if (!list_empty(&block->ccw_queue))
2692                                         break;
2693                                 spin_lock_irqsave(
2694                                         get_ccwdev_lock(basedev->cdev), flags);
2695                                 dasd_device_set_stop_bits(basedev,
2696                                                           DASD_STOPPED_PENDING);
2697                                 spin_unlock_irqrestore(
2698                                         get_ccwdev_lock(basedev->cdev), flags);
2699                                 dasd_block_set_timer(block, HZ/2);
2700                                 break;
2701                         }
2702                         DBF_DEV_EVENT(DBF_ERR, basedev,
2703                                       "CCW creation failed (rc=%ld) "
2704                                       "on request %p",
2705                                       PTR_ERR(cqr), req);
2706                         blk_start_request(req);
2707                         __blk_end_request_all(req, -EIO);
2708                         continue;
2709                 }
2710                 /*
2711                  *  Note: callback is set to dasd_return_cqr_cb in
2712                  * __dasd_block_start_head to cover erp requests as well
2713                  */
2714                 cqr->callback_data = (void *) req;
2715                 cqr->status = DASD_CQR_FILLED;
2716                 req->completion_data = cqr;
2717                 blk_start_request(req);
2718                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2719                 INIT_LIST_HEAD(&cqr->devlist);
2720                 dasd_profile_start(block, cqr, req);
2721         }
2722 }
2723
2724 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2725 {
2726         struct request *req;
2727         int status;
2728         int error = 0;
2729
2730         req = (struct request *) cqr->callback_data;
2731         dasd_profile_end(cqr->block, cqr, req);
2732         status = cqr->block->base->discipline->free_cp(cqr, req);
2733         if (status < 0)
2734                 error = status;
2735         else if (status == 0) {
2736                 if (cqr->intrc == -EPERM)
2737                         error = -EBADE;
2738                 else if (cqr->intrc == -ENOLINK ||
2739                          cqr->intrc == -ETIMEDOUT)
2740                         error = cqr->intrc;
2741                 else
2742                         error = -EIO;
2743         }
2744         __blk_end_request_all(req, error);
2745 }
2746
2747 /*
2748  * Process ccw request queue.
2749  */
2750 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2751                                            struct list_head *final_queue)
2752 {
2753         struct list_head *l, *n;
2754         struct dasd_ccw_req *cqr;
2755         dasd_erp_fn_t erp_fn;
2756         unsigned long flags;
2757         struct dasd_device *base = block->base;
2758
2759 restart:
2760         /* Process request with final status. */
2761         list_for_each_safe(l, n, &block->ccw_queue) {
2762                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2763                 if (cqr->status != DASD_CQR_DONE &&
2764                     cqr->status != DASD_CQR_FAILED &&
2765                     cqr->status != DASD_CQR_NEED_ERP &&
2766                     cqr->status != DASD_CQR_TERMINATED)
2767                         continue;
2768
2769                 if (cqr->status == DASD_CQR_TERMINATED) {
2770                         base->discipline->handle_terminated_request(cqr);
2771                         goto restart;
2772                 }
2773
2774                 /*  Process requests that may be recovered */
2775                 if (cqr->status == DASD_CQR_NEED_ERP) {
2776                         erp_fn = base->discipline->erp_action(cqr);
2777                         if (IS_ERR(erp_fn(cqr)))
2778                                 continue;
2779                         goto restart;
2780                 }
2781
2782                 /* log sense for fatal error */
2783                 if (cqr->status == DASD_CQR_FAILED) {
2784                         dasd_log_sense(cqr, &cqr->irb);
2785                 }
2786
2787                 /* First of all call extended error reporting. */
2788                 if (dasd_eer_enabled(base) &&
2789                     cqr->status == DASD_CQR_FAILED) {
2790                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2791
2792                         /* restart request  */
2793                         cqr->status = DASD_CQR_FILLED;
2794                         cqr->retries = 255;
2795                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2796                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2797                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2798                                                flags);
2799                         goto restart;
2800                 }
2801
2802                 /* Process finished ERP request. */
2803                 if (cqr->refers) {
2804                         __dasd_process_erp(base, cqr);
2805                         goto restart;
2806                 }
2807
2808                 /* Rechain finished requests to final queue */
2809                 cqr->endclk = get_tod_clock();
2810                 list_move_tail(&cqr->blocklist, final_queue);
2811         }
2812 }
2813
2814 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2815 {
2816         dasd_schedule_block_bh(cqr->block);
2817 }
2818
2819 static void __dasd_block_start_head(struct dasd_block *block)
2820 {
2821         struct dasd_ccw_req *cqr;
2822
2823         if (list_empty(&block->ccw_queue))
2824                 return;
2825         /* We allways begin with the first requests on the queue, as some
2826          * of previously started requests have to be enqueued on a
2827          * dasd_device again for error recovery.
2828          */
2829         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2830                 if (cqr->status != DASD_CQR_FILLED)
2831                         continue;
2832                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2833                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2834                         cqr->status = DASD_CQR_FAILED;
2835                         cqr->intrc = -EPERM;
2836                         dasd_schedule_block_bh(block);
2837                         continue;
2838                 }
2839                 /* Non-temporary stop condition will trigger fail fast */
2840                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2841                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2842                     (!dasd_eer_enabled(block->base))) {
2843                         cqr->status = DASD_CQR_FAILED;
2844                         cqr->intrc = -ENOLINK;
2845                         dasd_schedule_block_bh(block);
2846                         continue;
2847                 }
2848                 /* Don't try to start requests if device is stopped */
2849                 if (block->base->stopped)
2850                         return;
2851
2852                 /* just a fail safe check, should not happen */
2853                 if (!cqr->startdev)
2854                         cqr->startdev = block->base;
2855
2856                 /* make sure that the requests we submit find their way back */
2857                 cqr->callback = dasd_return_cqr_cb;
2858
2859                 dasd_add_request_tail(cqr);
2860         }
2861 }
2862
2863 /*
2864  * Central dasd_block layer routine. Takes requests from the generic
2865  * block layer request queue, creates ccw requests, enqueues them on
2866  * a dasd_device and processes ccw requests that have been returned.
2867  */
2868 static void dasd_block_tasklet(struct dasd_block *block)
2869 {
2870         struct list_head final_queue;
2871         struct list_head *l, *n;
2872         struct dasd_ccw_req *cqr;
2873
2874         atomic_set(&block->tasklet_scheduled, 0);
2875         INIT_LIST_HEAD(&final_queue);
2876         spin_lock(&block->queue_lock);
2877         /* Finish off requests on ccw queue */
2878         __dasd_process_block_ccw_queue(block, &final_queue);
2879         spin_unlock(&block->queue_lock);
2880         /* Now call the callback function of requests with final status */
2881         spin_lock_irq(&block->request_queue_lock);
2882         list_for_each_safe(l, n, &final_queue) {
2883                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2884                 list_del_init(&cqr->blocklist);
2885                 __dasd_cleanup_cqr(cqr);
2886         }
2887         spin_lock(&block->queue_lock);
2888         /* Get new request from the block device request queue */
2889         __dasd_process_request_queue(block);
2890         /* Now check if the head of the ccw queue needs to be started. */
2891         __dasd_block_start_head(block);
2892         spin_unlock(&block->queue_lock);
2893         spin_unlock_irq(&block->request_queue_lock);
2894         if (waitqueue_active(&shutdown_waitq))
2895                 wake_up(&shutdown_waitq);
2896         dasd_put_device(block->base);
2897 }
2898
2899 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2900 {
2901         wake_up(&dasd_flush_wq);
2902 }
2903
2904 /*
2905  * Requeue a request back to the block request queue
2906  * only works for block requests
2907  */
2908 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2909 {
2910         struct dasd_block *block = cqr->block;
2911         struct request *req;
2912         unsigned long flags;
2913
2914         if (!block)
2915                 return -EINVAL;
2916         spin_lock_irqsave(&block->queue_lock, flags);
2917         req = (struct request *) cqr->callback_data;
2918         blk_requeue_request(block->request_queue, req);
2919         spin_unlock_irqrestore(&block->queue_lock, flags);
2920
2921         return 0;
2922 }
2923
2924 /*
2925  * Go through all request on the dasd_block request queue, cancel them
2926  * on the respective dasd_device, and return them to the generic
2927  * block layer.
2928  */
2929 static int dasd_flush_block_queue(struct dasd_block *block)
2930 {
2931         struct dasd_ccw_req *cqr, *n;
2932         int rc, i;
2933         struct list_head flush_queue;
2934
2935         INIT_LIST_HEAD(&flush_queue);
2936         spin_lock_bh(&block->queue_lock);
2937         rc = 0;
2938 restart:
2939         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2940                 /* if this request currently owned by a dasd_device cancel it */
2941                 if (cqr->status >= DASD_CQR_QUEUED)
2942                         rc = dasd_cancel_req(cqr);
2943                 if (rc < 0)
2944                         break;
2945                 /* Rechain request (including erp chain) so it won't be
2946                  * touched by the dasd_block_tasklet anymore.
2947                  * Replace the callback so we notice when the request
2948                  * is returned from the dasd_device layer.
2949                  */
2950                 cqr->callback = _dasd_wake_block_flush_cb;
2951                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2952                         list_move_tail(&cqr->blocklist, &flush_queue);
2953                 if (i > 1)
2954                         /* moved more than one request - need to restart */
2955                         goto restart;
2956         }
2957         spin_unlock_bh(&block->queue_lock);
2958         /* Now call the callback function of flushed requests */
2959 restart_cb:
2960         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2961                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2962                 /* Process finished ERP request. */
2963                 if (cqr->refers) {
2964                         spin_lock_bh(&block->queue_lock);
2965                         __dasd_process_erp(block->base, cqr);
2966                         spin_unlock_bh(&block->queue_lock);
2967                         /* restart list_for_xx loop since dasd_process_erp
2968                          * might remove multiple elements */
2969                         goto restart_cb;
2970                 }
2971                 /* call the callback function */
2972                 spin_lock_irq(&block->request_queue_lock);
2973                 cqr->endclk = get_tod_clock();
2974                 list_del_init(&cqr->blocklist);
2975                 __dasd_cleanup_cqr(cqr);
2976                 spin_unlock_irq(&block->request_queue_lock);
2977         }
2978         return rc;
2979 }
2980
2981 /*
2982  * Schedules a call to dasd_tasklet over the device tasklet.
2983  */
2984 void dasd_schedule_block_bh(struct dasd_block *block)
2985 {
2986         /* Protect against rescheduling. */
2987         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2988                 return;
2989         /* life cycle of block is bound to it's base device */
2990         dasd_get_device(block->base);
2991         tasklet_hi_schedule(&block->tasklet);
2992 }
2993 EXPORT_SYMBOL(dasd_schedule_block_bh);
2994
2995
2996 /*
2997  * SECTION: external block device operations
2998  * (request queue handling, open, release, etc.)
2999  */
3000
3001 /*
3002  * Dasd request queue function. Called from ll_rw_blk.c
3003  */
3004 static void do_dasd_request(struct request_queue *queue)
3005 {
3006         struct dasd_block *block;
3007
3008         block = queue->queuedata;
3009         spin_lock(&block->queue_lock);
3010         /* Get new request from the block device request queue */
3011         __dasd_process_request_queue(block);
3012         /* Now check if the head of the ccw queue needs to be started. */
3013         __dasd_block_start_head(block);
3014         spin_unlock(&block->queue_lock);
3015 }
3016
3017 /*
3018  * Block timeout callback, called from the block layer
3019  *
3020  * request_queue lock is held on entry.
3021  *
3022  * Return values:
3023  * BLK_EH_RESET_TIMER if the request should be left running
3024  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3025  *                    by the driver.
3026  */
3027 enum blk_eh_timer_return dasd_times_out(struct request *req)
3028 {
3029         struct dasd_ccw_req *cqr = req->completion_data;
3030         struct dasd_block *block = req->q->queuedata;
3031         struct dasd_device *device;
3032         int rc = 0;
3033
3034         if (!cqr)
3035                 return BLK_EH_NOT_HANDLED;
3036
3037         device = cqr->startdev ? cqr->startdev : block->base;
3038         if (!device->blk_timeout)
3039                 return BLK_EH_RESET_TIMER;
3040         DBF_DEV_EVENT(DBF_WARNING, device,
3041                       " dasd_times_out cqr %p status %x",
3042                       cqr, cqr->status);
3043
3044         spin_lock(&block->queue_lock);
3045         spin_lock(get_ccwdev_lock(device->cdev));
3046         cqr->retries = -1;
3047         cqr->intrc = -ETIMEDOUT;
3048         if (cqr->status >= DASD_CQR_QUEUED) {
3049                 spin_unlock(get_ccwdev_lock(device->cdev));
3050                 rc = dasd_cancel_req(cqr);
3051         } else if (cqr->status == DASD_CQR_FILLED ||
3052                    cqr->status == DASD_CQR_NEED_ERP) {
3053                 cqr->status = DASD_CQR_TERMINATED;
3054                 spin_unlock(get_ccwdev_lock(device->cdev));
3055         } else if (cqr->status == DASD_CQR_IN_ERP) {
3056                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3057
3058                 list_for_each_entry_safe(searchcqr, nextcqr,
3059                                          &block->ccw_queue, blocklist) {
3060                         tmpcqr = searchcqr;
3061                         while (tmpcqr->refers)
3062                                 tmpcqr = tmpcqr->refers;
3063                         if (tmpcqr != cqr)
3064                                 continue;
3065                         /* searchcqr is an ERP request for cqr */
3066                         searchcqr->retries = -1;
3067                         searchcqr->intrc = -ETIMEDOUT;
3068                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3069                                 spin_unlock(get_ccwdev_lock(device->cdev));
3070                                 rc = dasd_cancel_req(searchcqr);
3071                                 spin_lock(get_ccwdev_lock(device->cdev));
3072                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3073                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3074                                 searchcqr->status = DASD_CQR_TERMINATED;
3075                                 rc = 0;
3076                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3077                                 /*
3078                                  * Shouldn't happen; most recent ERP
3079                                  * request is at the front of queue
3080                                  */
3081                                 continue;
3082                         }
3083                         break;
3084                 }
3085                 spin_unlock(get_ccwdev_lock(device->cdev));
3086         }
3087         dasd_schedule_block_bh(block);
3088         spin_unlock(&block->queue_lock);
3089
3090         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3091 }
3092
3093 /*
3094  * Allocate and initialize request queue and default I/O scheduler.
3095  */
3096 static int dasd_alloc_queue(struct dasd_block *block)
3097 {
3098         block->request_queue = blk_init_queue(do_dasd_request,
3099                                                &block->request_queue_lock);
3100         if (block->request_queue == NULL)
3101                 return -ENOMEM;
3102
3103         block->request_queue->queuedata = block;
3104
3105         return 0;
3106 }
3107
3108 /*
3109  * Allocate and initialize request queue.
3110  */
3111 static void dasd_setup_queue(struct dasd_block *block)
3112 {
3113         int max;
3114
3115         if (block->base->features & DASD_FEATURE_USERAW) {
3116                 /*
3117                  * the max_blocks value for raw_track access is 256
3118                  * it is higher than the native ECKD value because we
3119                  * only need one ccw per track
3120                  * so the max_hw_sectors are
3121                  * 2048 x 512B = 1024kB = 16 tracks
3122                  */
3123                 max = 2048;
3124         } else {
3125                 max = block->base->discipline->max_blocks << block->s2b_shift;
3126         }
3127         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue);
3128         block->request_queue->limits.max_dev_sectors = max;
3129         blk_queue_logical_block_size(block->request_queue,
3130                                      block->bp_block);
3131         blk_queue_max_hw_sectors(block->request_queue, max);
3132         blk_queue_max_segments(block->request_queue, -1L);
3133         /* with page sized segments we can translate each segement into
3134          * one idaw/tidaw
3135          */
3136         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3137         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3138 }
3139
3140 /*
3141  * Deactivate and free request queue.
3142  */
3143 static void dasd_free_queue(struct dasd_block *block)
3144 {
3145         if (block->request_queue) {
3146                 blk_cleanup_queue(block->request_queue);
3147                 block->request_queue = NULL;
3148         }
3149 }
3150
3151 /*
3152  * Flush request on the request queue.
3153  */
3154 static void dasd_flush_request_queue(struct dasd_block *block)
3155 {
3156         struct request *req;
3157
3158         if (!block->request_queue)
3159                 return;
3160
3161         spin_lock_irq(&block->request_queue_lock);
3162         while ((req = blk_fetch_request(block->request_queue)))
3163                 __blk_end_request_all(req, -EIO);
3164         spin_unlock_irq(&block->request_queue_lock);
3165 }
3166
3167 static int dasd_open(struct block_device *bdev, fmode_t mode)
3168 {
3169         struct dasd_device *base;
3170         int rc;
3171
3172         base = dasd_device_from_gendisk(bdev->bd_disk);
3173         if (!base)
3174                 return -ENODEV;
3175
3176         atomic_inc(&base->block->open_count);
3177         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3178                 rc = -ENODEV;
3179                 goto unlock;
3180         }
3181
3182         if (!try_module_get(base->discipline->owner)) {
3183                 rc = -EINVAL;
3184                 goto unlock;
3185         }
3186
3187         if (dasd_probeonly) {
3188                 dev_info(&base->cdev->dev,
3189                          "Accessing the DASD failed because it is in "
3190                          "probeonly mode\n");
3191                 rc = -EPERM;
3192                 goto out;
3193         }
3194
3195         if (base->state <= DASD_STATE_BASIC) {
3196                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3197                               " Cannot open unrecognized device");
3198                 rc = -ENODEV;
3199                 goto out;
3200         }
3201
3202         if ((mode & FMODE_WRITE) &&
3203             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3204              (base->features & DASD_FEATURE_READONLY))) {
3205                 rc = -EROFS;
3206                 goto out;
3207         }
3208
3209         dasd_put_device(base);
3210         return 0;
3211
3212 out:
3213         module_put(base->discipline->owner);
3214 unlock:
3215         atomic_dec(&base->block->open_count);
3216         dasd_put_device(base);
3217         return rc;
3218 }
3219
3220 static void dasd_release(struct gendisk *disk, fmode_t mode)
3221 {
3222         struct dasd_device *base = dasd_device_from_gendisk(disk);
3223         if (base) {
3224                 atomic_dec(&base->block->open_count);
3225                 module_put(base->discipline->owner);
3226                 dasd_put_device(base);
3227         }
3228 }
3229
3230 /*
3231  * Return disk geometry.
3232  */
3233 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3234 {
3235         struct dasd_device *base;
3236
3237         base = dasd_device_from_gendisk(bdev->bd_disk);
3238         if (!base)
3239                 return -ENODEV;
3240
3241         if (!base->discipline ||
3242             !base->discipline->fill_geometry) {
3243                 dasd_put_device(base);
3244                 return -EINVAL;
3245         }
3246         base->discipline->fill_geometry(base->block, geo);
3247         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3248         dasd_put_device(base);
3249         return 0;
3250 }
3251
3252 const struct block_device_operations
3253 dasd_device_operations = {
3254         .owner          = THIS_MODULE,
3255         .open           = dasd_open,
3256         .release        = dasd_release,
3257         .ioctl          = dasd_ioctl,
3258         .compat_ioctl   = dasd_ioctl,
3259         .getgeo         = dasd_getgeo,
3260 };
3261
3262 /*******************************************************************************
3263  * end of block device operations
3264  */
3265
3266 static void
3267 dasd_exit(void)
3268 {
3269 #ifdef CONFIG_PROC_FS
3270         dasd_proc_exit();
3271 #endif
3272         dasd_eer_exit();
3273         if (dasd_page_cache != NULL) {
3274                 kmem_cache_destroy(dasd_page_cache);
3275                 dasd_page_cache = NULL;
3276         }
3277         dasd_gendisk_exit();
3278         dasd_devmap_exit();
3279         if (dasd_debug_area != NULL) {
3280                 debug_unregister(dasd_debug_area);
3281                 dasd_debug_area = NULL;
3282         }
3283         dasd_statistics_removeroot();
3284 }
3285
3286 /*
3287  * SECTION: common functions for ccw_driver use
3288  */
3289
3290 /*
3291  * Is the device read-only?
3292  * Note that this function does not report the setting of the
3293  * readonly device attribute, but how it is configured in z/VM.
3294  */
3295 int dasd_device_is_ro(struct dasd_device *device)
3296 {
3297         struct ccw_dev_id dev_id;
3298         struct diag210 diag_data;
3299         int rc;
3300
3301         if (!MACHINE_IS_VM)
3302                 return 0;
3303         ccw_device_get_id(device->cdev, &dev_id);
3304         memset(&diag_data, 0, sizeof(diag_data));
3305         diag_data.vrdcdvno = dev_id.devno;
3306         diag_data.vrdclen = sizeof(diag_data);
3307         rc = diag210(&diag_data);
3308         if (rc == 0 || rc == 2) {
3309                 return diag_data.vrdcvfla & 0x80;
3310         } else {
3311                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3312                           dev_id.devno, rc);
3313                 return 0;
3314         }
3315 }
3316 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3317
3318 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3319 {
3320         struct ccw_device *cdev = data;
3321         int ret;
3322
3323         ret = ccw_device_set_online(cdev);
3324         if (ret)
3325                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3326                         dev_name(&cdev->dev), ret);
3327 }
3328
3329 /*
3330  * Initial attempt at a probe function. this can be simplified once
3331  * the other detection code is gone.
3332  */
3333 int dasd_generic_probe(struct ccw_device *cdev,
3334                        struct dasd_discipline *discipline)
3335 {
3336         int ret;
3337
3338         ret = dasd_add_sysfs_files(cdev);
3339         if (ret) {
3340                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3341                                 "dasd_generic_probe: could not add "
3342                                 "sysfs entries");
3343                 return ret;
3344         }
3345         cdev->handler = &dasd_int_handler;
3346
3347         /*
3348          * Automatically online either all dasd devices (dasd_autodetect)
3349          * or all devices specified with dasd= parameters during
3350          * initial probe.
3351          */
3352         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3353             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3354                 async_schedule(dasd_generic_auto_online, cdev);
3355         return 0;
3356 }
3357 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3358
3359 /*
3360  * This will one day be called from a global not_oper handler.
3361  * It is also used by driver_unregister during module unload.
3362  */
3363 void dasd_generic_remove(struct ccw_device *cdev)
3364 {
3365         struct dasd_device *device;
3366         struct dasd_block *block;
3367
3368         cdev->handler = NULL;
3369
3370         device = dasd_device_from_cdev(cdev);
3371         if (IS_ERR(device)) {
3372                 dasd_remove_sysfs_files(cdev);
3373                 return;
3374         }
3375         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3376             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3377                 /* Already doing offline processing */
3378                 dasd_put_device(device);
3379                 dasd_remove_sysfs_files(cdev);
3380                 return;
3381         }
3382         /*
3383          * This device is removed unconditionally. Set offline
3384          * flag to prevent dasd_open from opening it while it is
3385          * no quite down yet.
3386          */
3387         dasd_set_target_state(device, DASD_STATE_NEW);
3388         /* dasd_delete_device destroys the device reference. */
3389         block = device->block;
3390         dasd_delete_device(device);
3391         /*
3392          * life cycle of block is bound to device, so delete it after
3393          * device was safely removed
3394          */
3395         if (block)
3396                 dasd_free_block(block);
3397
3398         dasd_remove_sysfs_files(cdev);
3399 }
3400 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3401
3402 /*
3403  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3404  * the device is detected for the first time and is supposed to be used
3405  * or the user has started activation through sysfs.
3406  */
3407 int dasd_generic_set_online(struct ccw_device *cdev,
3408                             struct dasd_discipline *base_discipline)
3409 {
3410         struct dasd_discipline *discipline;
3411         struct dasd_device *device;
3412         int rc;
3413
3414         /* first online clears initial online feature flag */
3415         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3416         device = dasd_create_device(cdev);
3417         if (IS_ERR(device))
3418                 return PTR_ERR(device);
3419
3420         discipline = base_discipline;
3421         if (device->features & DASD_FEATURE_USEDIAG) {
3422                 if (!dasd_diag_discipline_pointer) {
3423                         /* Try to load the required module. */
3424                         rc = request_module(DASD_DIAG_MOD);
3425                         if (rc) {
3426                                 pr_warn("%s Setting the DASD online failed "
3427                                         "because the required module %s "
3428                                         "could not be loaded (rc=%d)\n",
3429                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3430                                         rc);
3431                                 dasd_delete_device(device);
3432                                 return -ENODEV;
3433                         }
3434                 }
3435                 /* Module init could have failed, so check again here after
3436                  * request_module(). */
3437                 if (!dasd_diag_discipline_pointer) {
3438                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3439                                 dev_name(&cdev->dev));
3440                         dasd_delete_device(device);
3441                         return -ENODEV;
3442                 }
3443                 discipline = dasd_diag_discipline_pointer;
3444         }
3445         if (!try_module_get(base_discipline->owner)) {
3446                 dasd_delete_device(device);
3447                 return -EINVAL;
3448         }
3449         if (!try_module_get(discipline->owner)) {
3450                 module_put(base_discipline->owner);
3451                 dasd_delete_device(device);
3452                 return -EINVAL;
3453         }
3454         device->base_discipline = base_discipline;
3455         device->discipline = discipline;
3456
3457         /* check_device will allocate block device if necessary */
3458         rc = discipline->check_device(device);
3459         if (rc) {
3460                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3461                         dev_name(&cdev->dev), discipline->name, rc);
3462                 module_put(discipline->owner);
3463                 module_put(base_discipline->owner);
3464                 dasd_delete_device(device);
3465                 return rc;
3466         }
3467
3468         dasd_set_target_state(device, DASD_STATE_ONLINE);
3469         if (device->state <= DASD_STATE_KNOWN) {
3470                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3471                         dev_name(&cdev->dev));
3472                 rc = -ENODEV;
3473                 dasd_set_target_state(device, DASD_STATE_NEW);
3474                 if (device->block)
3475                         dasd_free_block(device->block);
3476                 dasd_delete_device(device);
3477         } else
3478                 pr_debug("dasd_generic device %s found\n",
3479                                 dev_name(&cdev->dev));
3480
3481         wait_event(dasd_init_waitq, _wait_for_device(device));
3482
3483         dasd_put_device(device);
3484         return rc;
3485 }
3486 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3487
3488 int dasd_generic_set_offline(struct ccw_device *cdev)
3489 {
3490         struct dasd_device *device;
3491         struct dasd_block *block;
3492         int max_count, open_count, rc;
3493
3494         rc = 0;
3495         device = dasd_device_from_cdev(cdev);
3496         if (IS_ERR(device))
3497                 return PTR_ERR(device);
3498
3499         /*
3500          * We must make sure that this device is currently not in use.
3501          * The open_count is increased for every opener, that includes
3502          * the blkdev_get in dasd_scan_partitions. We are only interested
3503          * in the other openers.
3504          */
3505         if (device->block) {
3506                 max_count = device->block->bdev ? 0 : -1;
3507                 open_count = atomic_read(&device->block->open_count);
3508                 if (open_count > max_count) {
3509                         if (open_count > 0)
3510                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3511                                         dev_name(&cdev->dev), open_count);
3512                         else
3513                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3514                                         dev_name(&cdev->dev));
3515                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3516                         dasd_put_device(device);
3517                         return -EBUSY;
3518                 }
3519         }
3520
3521         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3522                 /*
3523                  * safe offline already running
3524                  * could only be called by normal offline so safe_offline flag
3525                  * needs to be removed to run normal offline and kill all I/O
3526                  */
3527                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3528                         /* Already doing normal offline processing */
3529                         dasd_put_device(device);
3530                         return -EBUSY;
3531                 } else
3532                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3533
3534         } else
3535                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3536                         /* Already doing offline processing */
3537                         dasd_put_device(device);
3538                         return -EBUSY;
3539                 }
3540
3541         /*
3542          * if safe_offline called set safe_offline_running flag and
3543          * clear safe_offline so that a call to normal offline
3544          * can overrun safe_offline processing
3545          */
3546         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3547             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3548                 /*
3549                  * If we want to set the device safe offline all IO operations
3550                  * should be finished before continuing the offline process
3551                  * so sync bdev first and then wait for our queues to become
3552                  * empty
3553                  */
3554                 /* sync blockdev and partitions */
3555                 rc = fsync_bdev(device->block->bdev);
3556                 if (rc != 0)
3557                         goto interrupted;
3558
3559                 /* schedule device tasklet and wait for completion */
3560                 dasd_schedule_device_bh(device);
3561                 rc = wait_event_interruptible(shutdown_waitq,
3562                                               _wait_for_empty_queues(device));
3563                 if (rc != 0)
3564                         goto interrupted;
3565         }
3566
3567         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3568         dasd_set_target_state(device, DASD_STATE_NEW);
3569         /* dasd_delete_device destroys the device reference. */
3570         block = device->block;
3571         dasd_delete_device(device);
3572         /*
3573          * life cycle of block is bound to device, so delete it after
3574          * device was safely removed
3575          */
3576         if (block)
3577                 dasd_free_block(block);
3578         return 0;
3579
3580 interrupted:
3581         /* interrupted by signal */
3582         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3583         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3584         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3585         dasd_put_device(device);
3586         return rc;
3587 }
3588 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3589
3590 int dasd_generic_last_path_gone(struct dasd_device *device)
3591 {
3592         struct dasd_ccw_req *cqr;
3593
3594         dev_warn(&device->cdev->dev, "No operational channel path is left "
3595                  "for the device\n");
3596         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3597         /* First of all call extended error reporting. */
3598         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3599
3600         if (device->state < DASD_STATE_BASIC)
3601                 return 0;
3602         /* Device is active. We want to keep it. */
3603         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3604                 if ((cqr->status == DASD_CQR_IN_IO) ||
3605                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3606                         cqr->status = DASD_CQR_QUEUED;
3607                         cqr->retries++;
3608                 }
3609         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3610         dasd_device_clear_timer(device);
3611         dasd_schedule_device_bh(device);
3612         return 1;
3613 }
3614 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3615
3616 int dasd_generic_path_operational(struct dasd_device *device)
3617 {
3618         dev_info(&device->cdev->dev, "A channel path to the device has become "
3619                  "operational\n");
3620         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3621         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3622         if (device->stopped & DASD_UNRESUMED_PM) {
3623                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3624                 dasd_restore_device(device);
3625                 return 1;
3626         }
3627         dasd_schedule_device_bh(device);
3628         if (device->block)
3629                 dasd_schedule_block_bh(device->block);
3630
3631         if (!device->stopped)
3632                 wake_up(&generic_waitq);
3633
3634         return 1;
3635 }
3636 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3637
3638 int dasd_generic_notify(struct ccw_device *cdev, int event)
3639 {
3640         struct dasd_device *device;
3641         int ret;
3642
3643         device = dasd_device_from_cdev_locked(cdev);
3644         if (IS_ERR(device))
3645                 return 0;
3646         ret = 0;
3647         switch (event) {
3648         case CIO_GONE:
3649         case CIO_BOXED:
3650         case CIO_NO_PATH:
3651                 device->path_data.opm = 0;
3652                 device->path_data.ppm = 0;
3653                 device->path_data.npm = 0;
3654                 ret = dasd_generic_last_path_gone(device);
3655                 break;
3656         case CIO_OPER:
3657                 ret = 1;
3658                 if (device->path_data.opm)
3659                         ret = dasd_generic_path_operational(device);
3660                 break;
3661         }
3662         dasd_put_device(device);
3663         return ret;
3664 }
3665 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3666
3667 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3668 {
3669         int chp;
3670         __u8 oldopm, eventlpm;
3671         struct dasd_device *device;
3672
3673         device = dasd_device_from_cdev_locked(cdev);
3674         if (IS_ERR(device))
3675                 return;
3676         for (chp = 0; chp < 8; chp++) {
3677                 eventlpm = 0x80 >> chp;
3678                 if (path_event[chp] & PE_PATH_GONE) {
3679                         oldopm = device->path_data.opm;
3680                         device->path_data.opm &= ~eventlpm;
3681                         device->path_data.ppm &= ~eventlpm;
3682                         device->path_data.npm &= ~eventlpm;
3683                         if (oldopm && !device->path_data.opm) {
3684                                 dev_warn(&device->cdev->dev,
3685                                          "No verified channel paths remain "
3686                                          "for the device\n");
3687                                 DBF_DEV_EVENT(DBF_WARNING, device,
3688                                               "%s", "last verified path gone");
3689                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3690                                 dasd_device_set_stop_bits(device,
3691                                                           DASD_STOPPED_DC_WAIT);
3692                         }
3693                 }
3694                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3695                         device->path_data.opm &= ~eventlpm;
3696                         device->path_data.ppm &= ~eventlpm;
3697                         device->path_data.npm &= ~eventlpm;
3698                         device->path_data.tbvpm |= eventlpm;
3699                         dasd_schedule_device_bh(device);
3700                 }
3701                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3702                         if (!(device->path_data.opm & eventlpm) &&
3703                             !(device->path_data.tbvpm & eventlpm)) {
3704                                 /*
3705                                  * we can not establish a pathgroup on an
3706                                  * unavailable path, so trigger a path
3707                                  * verification first
3708                                  */
3709                                 device->path_data.tbvpm |= eventlpm;
3710                                 dasd_schedule_device_bh(device);
3711                         }
3712                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3713                                       "Pathgroup re-established\n");
3714                         if (device->discipline->kick_validate)
3715                                 device->discipline->kick_validate(device);
3716                 }
3717         }
3718         dasd_put_device(device);
3719 }
3720 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3721
3722 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3723 {
3724         if (!device->path_data.opm && lpm) {
3725                 device->path_data.opm = lpm;
3726                 dasd_generic_path_operational(device);
3727         } else
3728                 device->path_data.opm |= lpm;
3729         return 0;
3730 }
3731 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3732
3733
3734 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3735 {
3736         struct dasd_device *device = dasd_device_from_cdev(cdev);
3737         struct list_head freeze_queue;
3738         struct dasd_ccw_req *cqr, *n;
3739         struct dasd_ccw_req *refers;
3740         int rc;
3741
3742         if (IS_ERR(device))
3743                 return PTR_ERR(device);
3744
3745         /* mark device as suspended */
3746         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3747
3748         if (device->discipline->freeze)
3749                 rc = device->discipline->freeze(device);
3750
3751         /* disallow new I/O  */
3752         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3753
3754         /* clear active requests and requeue them to block layer if possible */
3755         INIT_LIST_HEAD(&freeze_queue);
3756         spin_lock_irq(get_ccwdev_lock(cdev));
3757         rc = 0;
3758         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3759                 /* Check status and move request to flush_queue */
3760                 if (cqr->status == DASD_CQR_IN_IO) {
3761                         rc = device->discipline->term_IO(cqr);
3762                         if (rc) {
3763                                 /* unable to terminate requeust */
3764                                 dev_err(&device->cdev->dev,
3765                                         "Unable to terminate request %p "
3766                                         "on suspend\n", cqr);
3767                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3768                                 dasd_put_device(device);
3769                                 return rc;
3770                         }
3771                 }
3772                 list_move_tail(&cqr->devlist, &freeze_queue);
3773         }
3774         spin_unlock_irq(get_ccwdev_lock(cdev));
3775
3776         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3777                 wait_event(dasd_flush_wq,
3778                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3779                 if (cqr->status == DASD_CQR_CLEARED)
3780                         cqr->status = DASD_CQR_QUEUED;
3781
3782                 /* requeue requests to blocklayer will only work for
3783                    block device requests */
3784                 if (_dasd_requeue_request(cqr))
3785                         continue;
3786
3787                 /* remove requests from device and block queue */
3788                 list_del_init(&cqr->devlist);
3789                 while (cqr->refers != NULL) {
3790                         refers = cqr->refers;
3791                         /* remove the request from the block queue */
3792                         list_del(&cqr->blocklist);
3793                         /* free the finished erp request */
3794                         dasd_free_erp_request(cqr, cqr->memdev);
3795                         cqr = refers;
3796                 }
3797                 if (cqr->block)
3798                         list_del_init(&cqr->blocklist);
3799                 cqr->block->base->discipline->free_cp(
3800                         cqr, (struct request *) cqr->callback_data);
3801         }
3802
3803         /*
3804          * if requests remain then they are internal request
3805          * and go back to the device queue
3806          */
3807         if (!list_empty(&freeze_queue)) {
3808                 /* move freeze_queue to start of the ccw_queue */
3809                 spin_lock_irq(get_ccwdev_lock(cdev));
3810                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3811                 spin_unlock_irq(get_ccwdev_lock(cdev));
3812         }
3813         dasd_put_device(device);
3814         return rc;
3815 }
3816 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3817
3818 int dasd_generic_restore_device(struct ccw_device *cdev)
3819 {
3820         struct dasd_device *device = dasd_device_from_cdev(cdev);
3821         int rc = 0;
3822
3823         if (IS_ERR(device))
3824                 return PTR_ERR(device);
3825
3826         /* allow new IO again */
3827         dasd_device_remove_stop_bits(device,
3828                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3829
3830         dasd_schedule_device_bh(device);
3831
3832         /*
3833          * call discipline restore function
3834          * if device is stopped do nothing e.g. for disconnected devices
3835          */
3836         if (device->discipline->restore && !(device->stopped))
3837                 rc = device->discipline->restore(device);
3838         if (rc || device->stopped)
3839                 /*
3840                  * if the resume failed for the DASD we put it in
3841                  * an UNRESUMED stop state
3842                  */
3843                 device->stopped |= DASD_UNRESUMED_PM;
3844
3845         if (device->block)
3846                 dasd_schedule_block_bh(device->block);
3847
3848         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3849         dasd_put_device(device);
3850         return 0;
3851 }
3852 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3853
3854 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3855                                                    void *rdc_buffer,
3856                                                    int rdc_buffer_size,
3857                                                    int magic)
3858 {
3859         struct dasd_ccw_req *cqr;
3860         struct ccw1 *ccw;
3861         unsigned long *idaw;
3862
3863         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3864
3865         if (IS_ERR(cqr)) {
3866                 /* internal error 13 - Allocating the RDC request failed*/
3867                 dev_err(&device->cdev->dev,
3868                          "An error occurred in the DASD device driver, "
3869                          "reason=%s\n", "13");
3870                 return cqr;
3871         }
3872
3873         ccw = cqr->cpaddr;
3874         ccw->cmd_code = CCW_CMD_RDC;
3875         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3876                 idaw = (unsigned long *) (cqr->data);
3877                 ccw->cda = (__u32)(addr_t) idaw;
3878                 ccw->flags = CCW_FLAG_IDA;
3879                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3880         } else {
3881                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3882                 ccw->flags = 0;
3883         }
3884
3885         ccw->count = rdc_buffer_size;
3886         cqr->startdev = device;
3887         cqr->memdev = device;
3888         cqr->expires = 10*HZ;
3889         cqr->retries = 256;
3890         cqr->buildclk = get_tod_clock();
3891         cqr->status = DASD_CQR_FILLED;
3892         return cqr;
3893 }
3894
3895
3896 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3897                                 void *rdc_buffer, int rdc_buffer_size)
3898 {
3899         int ret;
3900         struct dasd_ccw_req *cqr;
3901
3902         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3903                                      magic);
3904         if (IS_ERR(cqr))
3905                 return PTR_ERR(cqr);
3906
3907         ret = dasd_sleep_on(cqr);
3908         dasd_sfree_request(cqr, cqr->memdev);
3909         return ret;
3910 }
3911 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3912
3913 /*
3914  *   In command mode and transport mode we need to look for sense
3915  *   data in different places. The sense data itself is allways
3916  *   an array of 32 bytes, so we can unify the sense data access
3917  *   for both modes.
3918  */
3919 char *dasd_get_sense(struct irb *irb)
3920 {
3921         struct tsb *tsb = NULL;
3922         char *sense = NULL;
3923
3924         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3925                 if (irb->scsw.tm.tcw)
3926                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3927                                           irb->scsw.tm.tcw);
3928                 if (tsb && tsb->length == 64 && tsb->flags)
3929                         switch (tsb->flags & 0x07) {
3930                         case 1: /* tsa_iostat */
3931                                 sense = tsb->tsa.iostat.sense;
3932                                 break;
3933                         case 2: /* tsa_ddpc */
3934                                 sense = tsb->tsa.ddpc.sense;
3935                                 break;
3936                         default:
3937                                 /* currently we don't use interrogate data */
3938                                 break;
3939                         }
3940         } else if (irb->esw.esw0.erw.cons) {
3941                 sense = irb->ecw;
3942         }
3943         return sense;
3944 }
3945 EXPORT_SYMBOL_GPL(dasd_get_sense);
3946
3947 void dasd_generic_shutdown(struct ccw_device *cdev)
3948 {
3949         struct dasd_device *device;
3950
3951         device = dasd_device_from_cdev(cdev);
3952         if (IS_ERR(device))
3953                 return;
3954
3955         if (device->block)
3956                 dasd_schedule_block_bh(device->block);
3957
3958         dasd_schedule_device_bh(device);
3959
3960         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3961 }
3962 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3963
3964 static int __init dasd_init(void)
3965 {
3966         int rc;
3967
3968         init_waitqueue_head(&dasd_init_waitq);
3969         init_waitqueue_head(&dasd_flush_wq);
3970         init_waitqueue_head(&generic_waitq);
3971         init_waitqueue_head(&shutdown_waitq);
3972
3973         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3974         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3975         if (dasd_debug_area == NULL) {
3976                 rc = -ENOMEM;
3977                 goto failed;
3978         }
3979         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3980         debug_set_level(dasd_debug_area, DBF_WARNING);
3981
3982         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3983
3984         dasd_diag_discipline_pointer = NULL;
3985
3986         dasd_statistics_createroot();
3987
3988         rc = dasd_devmap_init();
3989         if (rc)
3990                 goto failed;
3991         rc = dasd_gendisk_init();
3992         if (rc)
3993                 goto failed;
3994         rc = dasd_parse();
3995         if (rc)
3996                 goto failed;
3997         rc = dasd_eer_init();
3998         if (rc)
3999                 goto failed;
4000 #ifdef CONFIG_PROC_FS
4001         rc = dasd_proc_init();
4002         if (rc)
4003                 goto failed;
4004 #endif
4005
4006         return 0;
4007 failed:
4008         pr_info("The DASD device driver could not be initialized\n");
4009         dasd_exit();
4010         return rc;
4011 }
4012
4013 module_init(dasd_init);
4014 module_exit(dasd_exit);