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 /*
  42  * SECTION: exported variables of dasd.c
  43  */
  44 debug_info_t *dasd_debug_area;
  45 static struct dentry *dasd_debugfs_root_entry;
  46 struct dasd_discipline *dasd_diag_discipline_pointer;
  47 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  48
  49 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  50 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  51                    " Copyright IBM Corp. 2000");
  52 MODULE_SUPPORTED_DEVICE("dasd");
  53 MODULE_LICENSE("GPL");
  54
  55 /*
  56  * SECTION: prototypes for static functions of dasd.c
  57  */
  58 static int  dasd_alloc_queue(struct dasd_block *);
  59 static void dasd_setup_queue(struct dasd_block *);
  60 static void dasd_free_queue(struct dasd_block *);
  61 static void dasd_flush_request_queue(struct dasd_block *);
  62 static int dasd_flush_block_queue(struct dasd_block *);
  63 static void dasd_device_tasklet(struct dasd_device *);
  64 static void dasd_block_tasklet(struct dasd_block *);
  65 static void do_kick_device(struct work_struct *);
  66 static void do_restore_device(struct work_struct *);
  67 static void do_reload_device(struct work_struct *);
  68 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  69 static void dasd_device_timeout(unsigned long);
  70 static void dasd_block_timeout(unsigned long);
  71 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  72 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  73 static void dasd_profile_exit(struct dasd_profile *);
  74
  75 /*
  76  * SECTION: Operations on the device structure.
  77  */
  78 static wait_queue_head_t dasd_init_waitq;
  79 static wait_queue_head_t dasd_flush_wq;
  80 static wait_queue_head_t generic_waitq;
  81 static wait_queue_head_t shutdown_waitq;
  82
  83 /*
  84  * Allocate memory for a new device structure.
  85  */
  86 struct dasd_device *dasd_alloc_device(void)
  87 {
  88         struct dasd_device *device;
  89
  90         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  91         if (!device)
  92                 return ERR_PTR(-ENOMEM);
  93
  94         /* Get two pages for normal block device operations. */
  95         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  96         if (!device->ccw_mem) {
  97                 kfree(device);
  98                 return ERR_PTR(-ENOMEM);
  99         }
 100         /* Get one page for error recovery. */
 101         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 102         if (!device->erp_mem) {
 103                 free_pages((unsigned long) device->ccw_mem, 1);
 104                 kfree(device);
 105                 return ERR_PTR(-ENOMEM);
 106         }
 107
 108         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 109         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 110         spin_lock_init(&device->mem_lock);
 111         atomic_set(&device->tasklet_scheduled, 0);
 112         tasklet_init(&device->tasklet,
 113                      (void (*)(unsigned long)) dasd_device_tasklet,
 114                      (unsigned long) device);
 115         INIT_LIST_HEAD(&device->ccw_queue);
 116         init_timer(&device->timer);
 117         device->timer.function = dasd_device_timeout;
 118         device->timer.data = (unsigned long) device;
 119         INIT_WORK(&device->kick_work, do_kick_device);
 120         INIT_WORK(&device->restore_device, do_restore_device);
 121         INIT_WORK(&device->reload_device, do_reload_device);
 122         device->state = DASD_STATE_NEW;
 123         device->target = DASD_STATE_NEW;
 124         mutex_init(&device->state_mutex);
 125         spin_lock_init(&device->profile.lock);
 126         return device;
 127 }
 128
 129 /*
 130  * Free memory of a device structure.
 131  */
 132 void dasd_free_device(struct dasd_device *device)
 133 {
 134         kfree(device->private);
 135         free_page((unsigned long) device->erp_mem);
 136         free_pages((unsigned long) device->ccw_mem, 1);
 137         kfree(device);
 138 }
 139
 140 /*
 141  * Allocate memory for a new device structure.
 142  */
 143 struct dasd_block *dasd_alloc_block(void)
 144 {
 145         struct dasd_block *block;
 146
 147         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 148         if (!block)
 149                 return ERR_PTR(-ENOMEM);
 150         /* open_count = 0 means device online but not in use */
 151         atomic_set(&block->open_count, -1);
 152
 153         spin_lock_init(&block->request_queue_lock);
 154         atomic_set(&block->tasklet_scheduled, 0);
 155         tasklet_init(&block->tasklet,
 156                      (void (*)(unsigned long)) dasd_block_tasklet,
 157                      (unsigned long) block);
 158         INIT_LIST_HEAD(&block->ccw_queue);
 159         spin_lock_init(&block->queue_lock);
 160         init_timer(&block->timer);
 161         block->timer.function = dasd_block_timeout;
 162         block->timer.data = (unsigned long) block;
 163         spin_lock_init(&block->profile.lock);
 164
 165         return block;
 166 }
 167
 168 /*
 169  * Free memory of a device structure.
 170  */
 171 void dasd_free_block(struct dasd_block *block)
 172 {
 173         kfree(block);
 174 }
 175
 176 /*
 177  * Make a new device known to the system.
 178  */
 179 static int dasd_state_new_to_known(struct dasd_device *device)
 180 {
 181         int rc;
 182
 183         /*
 184          * As long as the device is not in state DASD_STATE_NEW we want to
 185          * keep the reference count > 0.
 186          */
 187         dasd_get_device(device);
 188
 189         if (device->block) {
 190                 rc = dasd_alloc_queue(device->block);
 191                 if (rc) {
 192                         dasd_put_device(device);
 193                         return rc;
 194                 }
 195         }
 196         device->state = DASD_STATE_KNOWN;
 197         return 0;
 198 }
 199
 200 /*
 201  * Let the system forget about a device.
 202  */
 203 static int dasd_state_known_to_new(struct dasd_device *device)
 204 {
 205         /* Disable extended error reporting for this device. */
 206         dasd_eer_disable(device);
 207         /* Forget the discipline information. */
 208         if (device->discipline) {
 209                 if (device->discipline->uncheck_device)
 210                         device->discipline->uncheck_device(device);
 211                 module_put(device->discipline->owner);
 212         }
 213         device->discipline = NULL;
 214         if (device->base_discipline)
 215                 module_put(device->base_discipline->owner);
 216         device->base_discipline = NULL;
 217         device->state = DASD_STATE_NEW;
 218
 219         if (device->block)
 220                 dasd_free_queue(device->block);
 221
 222         /* Give up reference we took in dasd_state_new_to_known. */
 223         dasd_put_device(device);
 224         return 0;
 225 }
 226
 227 static struct dentry *dasd_debugfs_setup(const char *name,
 228                                          struct dentry *base_dentry)
 229 {
 230         struct dentry *pde;
 231
 232         if (!base_dentry)
 233                 return NULL;
 234         pde = debugfs_create_dir(name, base_dentry);
 235         if (!pde || IS_ERR(pde))
 236                 return NULL;
 237         return pde;
 238 }
 239
 240 /*
 241  * Request the irq line for the device.
 242  */
 243 static int dasd_state_known_to_basic(struct dasd_device *device)
 244 {
 245         struct dasd_block *block = device->block;
 246         int rc = 0;
 247
 248         /* Allocate and register gendisk structure. */
 249         if (block) {
 250                 rc = dasd_gendisk_alloc(block);
 251                 if (rc)
 252                         return rc;
 253                 block->debugfs_dentry =
 254                         dasd_debugfs_setup(block->gdp->disk_name,
 255                                            dasd_debugfs_root_entry);
 256                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 257                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 258                         dasd_profile_on(&device->block->profile);
 259         }
 260         device->debugfs_dentry =
 261                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 262                                    dasd_debugfs_root_entry);
 263         dasd_profile_init(&device->profile, device->debugfs_dentry);
 264
 265         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 266         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 267                                             8 * sizeof(long));
 268         debug_register_view(device->debug_area, &debug_sprintf_view);
 269         debug_set_level(device->debug_area, DBF_WARNING);
 270         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 271
 272         device->state = DASD_STATE_BASIC;
 273
 274         return rc;
 275 }
 276
 277 /*
 278  * Release the irq line for the device. Terminate any running i/o.
 279  */
 280 static int dasd_state_basic_to_known(struct dasd_device *device)
 281 {
 282         int rc;
 283
 284         if (device->block) {
 285                 dasd_profile_exit(&device->block->profile);
 286                 if (device->block->debugfs_dentry)
 287                         debugfs_remove(device->block->debugfs_dentry);
 288                 dasd_gendisk_free(device->block);
 289                 dasd_block_clear_timer(device->block);
 290         }
 291         rc = dasd_flush_device_queue(device);
 292         if (rc)
 293                 return rc;
 294         dasd_device_clear_timer(device);
 295         dasd_profile_exit(&device->profile);
 296         if (device->debugfs_dentry)
 297                 debugfs_remove(device->debugfs_dentry);
 298
 299         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 300         if (device->debug_area != NULL) {
 301                 debug_unregister(device->debug_area);
 302                 device->debug_area = NULL;
 303         }
 304         device->state = DASD_STATE_KNOWN;
 305         return 0;
 306 }
 307
 308 /*
 309  * Do the initial analysis. The do_analysis function may return
 310  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 311  * until the discipline decides to continue the startup sequence
 312  * by calling the function dasd_change_state. The eckd disciplines
 313  * uses this to start a ccw that detects the format. The completion
 314  * interrupt for this detection ccw uses the kernel event daemon to
 315  * trigger the call to dasd_change_state. All this is done in the
 316  * discipline code, see dasd_eckd.c.
 317  * After the analysis ccw is done (do_analysis returned 0) the block
 318  * device is setup.
 319  * In case the analysis returns an error, the device setup is stopped
 320  * (a fake disk was already added to allow formatting).
 321  */
 322 static int dasd_state_basic_to_ready(struct dasd_device *device)
 323 {
 324         int rc;
 325         struct dasd_block *block;
 326
 327         rc = 0;
 328         block = device->block;
 329         /* make disk known with correct capacity */
 330         if (block) {
 331                 if (block->base->discipline->do_analysis != NULL)
 332                         rc = block->base->discipline->do_analysis(block);
 333                 if (rc) {
 334                         if (rc != -EAGAIN) {
 335                                 device->state = DASD_STATE_UNFMT;
 336                                 goto out;
 337                         }
 338                         return rc;
 339                 }
 340                 dasd_setup_queue(block);
 341                 set_capacity(block->gdp,
 342                              block->blocks << block->s2b_shift);
 343                 device->state = DASD_STATE_READY;
 344                 rc = dasd_scan_partitions(block);
 345                 if (rc) {
 346                         device->state = DASD_STATE_BASIC;
 347                         return rc;
 348                 }
 349         } else {
 350                 device->state = DASD_STATE_READY;
 351         }
 352 out:
 353         if (device->discipline->basic_to_ready)
 354                 rc = device->discipline->basic_to_ready(device);
 355         return rc;
 356 }
 357
 358 static inline
 359 int _wait_for_empty_queues(struct dasd_device *device)
 360 {
 361         if (device->block)
 362                 return list_empty(&device->ccw_queue) &&
 363                         list_empty(&device->block->ccw_queue);
 364         else
 365                 return list_empty(&device->ccw_queue);
 366 }
 367
 368 /*
 369  * Remove device from block device layer. Destroy dirty buffers.
 370  * Forget format information. Check if the target level is basic
 371  * and if it is create fake disk for formatting.
 372  */
 373 static int dasd_state_ready_to_basic(struct dasd_device *device)
 374 {
 375         int rc;
 376
 377         if (device->discipline->ready_to_basic) {
 378                 rc = device->discipline->ready_to_basic(device);
 379                 if (rc)
 380                         return rc;
 381         }
 382         device->state = DASD_STATE_BASIC;
 383         if (device->block) {
 384                 struct dasd_block *block = device->block;
 385                 rc = dasd_flush_block_queue(block);
 386                 if (rc) {
 387                         device->state = DASD_STATE_READY;
 388                         return rc;
 389                 }
 390                 dasd_flush_request_queue(block);
 391                 dasd_destroy_partitions(block);
 392                 block->blocks = 0;
 393                 block->bp_block = 0;
 394                 block->s2b_shift = 0;
 395         }
 396         return 0;
 397 }
 398
 399 /*
 400  * Back to basic.
 401  */
 402 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 403 {
 404         device->state = DASD_STATE_BASIC;
 405         return 0;
 406 }
 407
 408 /*
 409  * Make the device online and schedule the bottom half to start
 410  * the requeueing of requests from the linux request queue to the
 411  * ccw queue.
 412  */
 413 static int
 414 dasd_state_ready_to_online(struct dasd_device * device)
 415 {
 416         struct gendisk *disk;
 417         struct disk_part_iter piter;
 418         struct hd_struct *part;
 419
 420         device->state = DASD_STATE_ONLINE;
 421         if (device->block) {
 422                 dasd_schedule_block_bh(device->block);
 423                 if ((device->features & DASD_FEATURE_USERAW)) {
 424                         disk = device->block->gdp;
 425                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 426                         return 0;
 427                 }
 428                 disk = device->block->bdev->bd_disk;
 429                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 430                 while ((part = disk_part_iter_next(&piter)))
 431                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 432                 disk_part_iter_exit(&piter);
 433         }
 434         return 0;
 435 }
 436
 437 /*
 438  * Stop the requeueing of requests again.
 439  */
 440 static int dasd_state_online_to_ready(struct dasd_device *device)
 441 {
 442         int rc;
 443         struct gendisk *disk;
 444         struct disk_part_iter piter;
 445         struct hd_struct *part;
 446
 447         if (device->discipline->online_to_ready) {
 448                 rc = device->discipline->online_to_ready(device);
 449                 if (rc)
 450                         return rc;
 451         }
 452
 453         device->state = DASD_STATE_READY;
 454         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 455                 disk = device->block->bdev->bd_disk;
 456                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 457                 while ((part = disk_part_iter_next(&piter)))
 458                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 459                 disk_part_iter_exit(&piter);
 460         }
 461         return 0;
 462 }
 463
 464 /*
 465  * Device startup state changes.
 466  */
 467 static int dasd_increase_state(struct dasd_device *device)
 468 {
 469         int rc;
 470
 471         rc = 0;
 472         if (device->state == DASD_STATE_NEW &&
 473             device->target >= DASD_STATE_KNOWN)
 474                 rc = dasd_state_new_to_known(device);
 475
 476         if (!rc &&
 477             device->state == DASD_STATE_KNOWN &&
 478             device->target >= DASD_STATE_BASIC)
 479                 rc = dasd_state_known_to_basic(device);
 480
 481         if (!rc &&
 482             device->state == DASD_STATE_BASIC &&
 483             device->target >= DASD_STATE_READY)
 484                 rc = dasd_state_basic_to_ready(device);
 485
 486         if (!rc &&
 487             device->state == DASD_STATE_UNFMT &&
 488             device->target > DASD_STATE_UNFMT)
 489                 rc = -EPERM;
 490
 491         if (!rc &&
 492             device->state == DASD_STATE_READY &&
 493             device->target >= DASD_STATE_ONLINE)
 494                 rc = dasd_state_ready_to_online(device);
 495
 496         return rc;
 497 }
 498
 499 /*
 500  * Device shutdown state changes.
 501  */
 502 static int dasd_decrease_state(struct dasd_device *device)
 503 {
 504         int rc;
 505
 506         rc = 0;
 507         if (device->state == DASD_STATE_ONLINE &&
 508             device->target <= DASD_STATE_READY)
 509                 rc = dasd_state_online_to_ready(device);
 510
 511         if (!rc &&
 512             device->state == DASD_STATE_READY &&
 513             device->target <= DASD_STATE_BASIC)
 514                 rc = dasd_state_ready_to_basic(device);
 515
 516         if (!rc &&
 517             device->state == DASD_STATE_UNFMT &&
 518             device->target <= DASD_STATE_BASIC)
 519                 rc = dasd_state_unfmt_to_basic(device);
 520
 521         if (!rc &&
 522             device->state == DASD_STATE_BASIC &&
 523             device->target <= DASD_STATE_KNOWN)
 524                 rc = dasd_state_basic_to_known(device);
 525
 526         if (!rc &&
 527             device->state == DASD_STATE_KNOWN &&
 528             device->target <= DASD_STATE_NEW)
 529                 rc = dasd_state_known_to_new(device);
 530
 531         return rc;
 532 }
 533
 534 /*
 535  * This is the main startup/shutdown routine.
 536  */
 537 static void dasd_change_state(struct dasd_device *device)
 538 {
 539         int rc;
 540
 541         if (device->state == device->target)
 542                 /* Already where we want to go today... */
 543                 return;
 544         if (device->state < device->target)
 545                 rc = dasd_increase_state(device);
 546         else
 547                 rc = dasd_decrease_state(device);
 548         if (rc == -EAGAIN)
 549                 return;
 550         if (rc)
 551                 device->target = device->state;
 552
 553         /* let user-space know that the device status changed */
 554         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 555
 556         if (device->state == device->target)
 557                 wake_up(&dasd_init_waitq);
 558 }
 559
 560 /*
 561  * Kick starter for devices that did not complete the startup/shutdown
 562  * procedure or were sleeping because of a pending state.
 563  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 564  * event daemon.
 565  */
 566 static void do_kick_device(struct work_struct *work)
 567 {
 568         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 569         mutex_lock(&device->state_mutex);
 570         dasd_change_state(device);
 571         mutex_unlock(&device->state_mutex);
 572         dasd_schedule_device_bh(device);
 573         dasd_put_device(device);
 574 }
 575
 576 void dasd_kick_device(struct dasd_device *device)
 577 {
 578         dasd_get_device(device);
 579         /* queue call to dasd_kick_device to the kernel event daemon. */
 580         schedule_work(&device->kick_work);
 581 }
 582
 583 /*
 584  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 585  * event daemon.
 586  */
 587 static void do_reload_device(struct work_struct *work)
 588 {
 589         struct dasd_device *device = container_of(work, struct dasd_device,
 590                                                   reload_device);
 591         device->discipline->reload(device);
 592         dasd_put_device(device);
 593 }
 594
 595 void dasd_reload_device(struct dasd_device *device)
 596 {
 597         dasd_get_device(device);
 598         /* queue call to dasd_reload_device to the kernel event daemon. */
 599         schedule_work(&device->reload_device);
 600 }
 601 EXPORT_SYMBOL(dasd_reload_device);
 602
 603 /*
 604  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 605  * event daemon.
 606  */
 607 static void do_restore_device(struct work_struct *work)
 608 {
 609         struct dasd_device *device = container_of(work, struct dasd_device,
 610                                                   restore_device);
 611         device->cdev->drv->restore(device->cdev);
 612         dasd_put_device(device);
 613 }
 614
 615 void dasd_restore_device(struct dasd_device *device)
 616 {
 617         dasd_get_device(device);
 618         /* queue call to dasd_restore_device to the kernel event daemon. */
 619         schedule_work(&device->restore_device);
 620 }
 621
 622 /*
 623  * Set the target state for a device and starts the state change.
 624  */
 625 void dasd_set_target_state(struct dasd_device *device, int target)
 626 {
 627         dasd_get_device(device);
 628         mutex_lock(&device->state_mutex);
 629         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 630         if (dasd_probeonly && target > DASD_STATE_READY)
 631                 target = DASD_STATE_READY;
 632         if (device->target != target) {
 633                 if (device->state == target)
 634                         wake_up(&dasd_init_waitq);
 635                 device->target = target;
 636         }
 637         if (device->state != device->target)
 638                 dasd_change_state(device);
 639         mutex_unlock(&device->state_mutex);
 640         dasd_put_device(device);
 641 }
 642
 643 /*
 644  * Enable devices with device numbers in [from..to].
 645  */
 646 static inline int _wait_for_device(struct dasd_device *device)
 647 {
 648         return (device->state == device->target);
 649 }
 650
 651 void dasd_enable_device(struct dasd_device *device)
 652 {
 653         dasd_set_target_state(device, DASD_STATE_ONLINE);
 654         if (device->state <= DASD_STATE_KNOWN)
 655                 /* No discipline for device found. */
 656                 dasd_set_target_state(device, DASD_STATE_NEW);
 657         /* Now wait for the devices to come up. */
 658         wait_event(dasd_init_waitq, _wait_for_device(device));
 659
 660         dasd_reload_device(device);
 661         if (device->discipline->kick_validate)
 662                 device->discipline->kick_validate(device);
 663 }
 664
 665 /*
 666  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 667  */
 668
 669 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 670
 671 #ifdef CONFIG_DASD_PROFILE
 672 struct dasd_profile_info dasd_global_profile_data;
 673 static struct dentry *dasd_global_profile_dentry;
 674 static struct dentry *dasd_debugfs_global_entry;
 675
 676 /*
 677  * Add profiling information for cqr before execution.
 678  */
 679 static void dasd_profile_start(struct dasd_block *block,
 680                                struct dasd_ccw_req *cqr,
 681                                struct request *req)
 682 {
 683         struct list_head *l;
 684         unsigned int counter;
 685         struct dasd_device *device;
 686
 687         /* count the length of the chanq for statistics */
 688         counter = 0;
 689         if (dasd_global_profile_level || block->profile.data)
 690                 list_for_each(l, &block->ccw_queue)
 691                         if (++counter >= 31)
 692                                 break;
 693
 694         if (dasd_global_profile_level) {
 695                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 696                 if (rq_data_dir(req) == READ)
 697                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 698         }
 699
 700         spin_lock(&block->profile.lock);
 701         if (block->profile.data) {
 702                 block->profile.data->dasd_io_nr_req[counter]++;
 703                 if (rq_data_dir(req) == READ)
 704                         block->profile.data->dasd_read_nr_req[counter]++;
 705         }
 706         spin_unlock(&block->profile.lock);
 707
 708         /*
 709          * We count the request for the start device, even though it may run on
 710          * some other device due to error recovery. This way we make sure that
 711          * we count each request only once.
 712          */
 713         device = cqr->startdev;
 714         if (device->profile.data) {
 715                 counter = 1; /* request is not yet queued on the start device */
 716                 list_for_each(l, &device->ccw_queue)
 717                         if (++counter >= 31)
 718                                 break;
 719         }
 720         spin_lock(&device->profile.lock);
 721         if (device->profile.data) {
 722                 device->profile.data->dasd_io_nr_req[counter]++;
 723                 if (rq_data_dir(req) == READ)
 724                         device->profile.data->dasd_read_nr_req[counter]++;
 725         }
 726         spin_unlock(&device->profile.lock);
 727 }
 728
 729 /*
 730  * Add profiling information for cqr after execution.
 731  */
 732
 733 #define dasd_profile_counter(value, index)                         \
 734 {                                                                  \
 735         for (index = 0; index < 31 && value >> (2+index); index++) \
 736                 ;                                                  \
 737 }
 738
 739 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 740                                       int is_alias,
 741                                       int is_tpm,
 742                                       int is_read,
 743                                       long sectors,
 744                                       int sectors_ind,
 745                                       int tottime_ind,
 746                                       int tottimeps_ind,
 747                                       int strtime_ind,
 748                                       int irqtime_ind,
 749                                       int irqtimeps_ind,
 750                                       int endtime_ind)
 751 {
 752         /* in case of an overflow, reset the whole profile */
 753         if (data->dasd_io_reqs == UINT_MAX) {
 754                         memset(data, 0, sizeof(*data));
 755                         getnstimeofday(&data->starttod);
 756         }
 757         data->dasd_io_reqs++;
 758         data->dasd_io_sects += sectors;
 759         if (is_alias)
 760                 data->dasd_io_alias++;
 761         if (is_tpm)
 762                 data->dasd_io_tpm++;
 763
 764         data->dasd_io_secs[sectors_ind]++;
 765         data->dasd_io_times[tottime_ind]++;
 766         data->dasd_io_timps[tottimeps_ind]++;
 767         data->dasd_io_time1[strtime_ind]++;
 768         data->dasd_io_time2[irqtime_ind]++;
 769         data->dasd_io_time2ps[irqtimeps_ind]++;
 770         data->dasd_io_time3[endtime_ind]++;
 771
 772         if (is_read) {
 773                 data->dasd_read_reqs++;
 774                 data->dasd_read_sects += sectors;
 775                 if (is_alias)
 776                         data->dasd_read_alias++;
 777                 if (is_tpm)
 778                         data->dasd_read_tpm++;
 779                 data->dasd_read_secs[sectors_ind]++;
 780                 data->dasd_read_times[tottime_ind]++;
 781                 data->dasd_read_time1[strtime_ind]++;
 782                 data->dasd_read_time2[irqtime_ind]++;
 783                 data->dasd_read_time3[endtime_ind]++;
 784         }
 785 }
 786
 787 static void dasd_profile_end(struct dasd_block *block,
 788                              struct dasd_ccw_req *cqr,
 789                              struct request *req)
 790 {
 791         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 792         long tottimeps, sectors;
 793         struct dasd_device *device;
 794         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 795         int irqtime_ind, irqtimeps_ind, endtime_ind;
 796
 797         device = cqr->startdev;
 798         if (!(dasd_global_profile_level ||
 799               block->profile.data ||
 800               device->profile.data))
 801                 return;
 802
 803         sectors = blk_rq_sectors(req);
 804         if (!cqr->buildclk || !cqr->startclk ||
 805             !cqr->stopclk || !cqr->endclk ||
 806             !sectors)
 807                 return;
 808
 809         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 810         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 811         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 812         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 813         tottimeps = tottime / sectors;
 814
 815         dasd_profile_counter(sectors, sectors_ind);
 816         dasd_profile_counter(tottime, tottime_ind);
 817         dasd_profile_counter(tottimeps, tottimeps_ind);
 818         dasd_profile_counter(strtime, strtime_ind);
 819         dasd_profile_counter(irqtime, irqtime_ind);
 820         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 821         dasd_profile_counter(endtime, endtime_ind);
 822
 823         if (dasd_global_profile_level) {
 824                 dasd_profile_end_add_data(&dasd_global_profile_data,
 825                                           cqr->startdev != block->base,
 826                                           cqr->cpmode == 1,
 827                                           rq_data_dir(req) == READ,
 828                                           sectors, sectors_ind, tottime_ind,
 829                                           tottimeps_ind, strtime_ind,
 830                                           irqtime_ind, irqtimeps_ind,
 831                                           endtime_ind);
 832         }
 833
 834         spin_lock(&block->profile.lock);
 835         if (block->profile.data)
 836                 dasd_profile_end_add_data(block->profile.data,
 837                                           cqr->startdev != block->base,
 838                                           cqr->cpmode == 1,
 839                                           rq_data_dir(req) == READ,
 840                                           sectors, sectors_ind, tottime_ind,
 841                                           tottimeps_ind, strtime_ind,
 842                                           irqtime_ind, irqtimeps_ind,
 843                                           endtime_ind);
 844         spin_unlock(&block->profile.lock);
 845
 846         spin_lock(&device->profile.lock);
 847         if (device->profile.data)
 848                 dasd_profile_end_add_data(device->profile.data,
 849                                           cqr->startdev != block->base,
 850                                           cqr->cpmode == 1,
 851                                           rq_data_dir(req) == READ,
 852                                           sectors, sectors_ind, tottime_ind,
 853                                           tottimeps_ind, strtime_ind,
 854                                           irqtime_ind, irqtimeps_ind,
 855                                           endtime_ind);
 856         spin_unlock(&device->profile.lock);
 857 }
 858
 859 void dasd_profile_reset(struct dasd_profile *profile)
 860 {
 861         struct dasd_profile_info *data;
 862
 863         spin_lock_bh(&profile->lock);
 864         data = profile->data;
 865         if (!data) {
 866                 spin_unlock_bh(&profile->lock);
 867                 return;
 868         }
 869         memset(data, 0, sizeof(*data));
 870         getnstimeofday(&data->starttod);
 871         spin_unlock_bh(&profile->lock);
 872 }
 873
 874 void dasd_global_profile_reset(void)
 875 {
 876         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 877         getnstimeofday(&dasd_global_profile_data.starttod);
 878 }
 879
 880 int dasd_profile_on(struct dasd_profile *profile)
 881 {
 882         struct dasd_profile_info *data;
 883
 884         data = kzalloc(sizeof(*data), GFP_KERNEL);
 885         if (!data)
 886                 return -ENOMEM;
 887         spin_lock_bh(&profile->lock);
 888         if (profile->data) {
 889                 spin_unlock_bh(&profile->lock);
 890                 kfree(data);
 891                 return 0;
 892         }
 893         getnstimeofday(&data->starttod);
 894         profile->data = data;
 895         spin_unlock_bh(&profile->lock);
 896         return 0;
 897 }
 898
 899 void dasd_profile_off(struct dasd_profile *profile)
 900 {
 901         spin_lock_bh(&profile->lock);
 902         kfree(profile->data);
 903         profile->data = NULL;
 904         spin_unlock_bh(&profile->lock);
 905 }
 906
 907 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 908 {
 909         char *buffer;
 910
 911         buffer = vmalloc(user_len + 1);
 912         if (buffer == NULL)
 913                 return ERR_PTR(-ENOMEM);
 914         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 915                 vfree(buffer);
 916                 return ERR_PTR(-EFAULT);
 917         }
 918         /* got the string, now strip linefeed. */
 919         if (buffer[user_len - 1] == '\n')
 920                 buffer[user_len - 1] = 0;
 921         else
 922                 buffer[user_len] = 0;
 923         return buffer;
 924 }
 925
 926 static ssize_t dasd_stats_write(struct file *file,
 927                                 const char __user *user_buf,
 928                                 size_t user_len, loff_t *pos)
 929 {
 930         char *buffer, *str;
 931         int rc;
 932         struct seq_file *m = (struct seq_file *)file->private_data;
 933         struct dasd_profile *prof = m->private;
 934
 935         if (user_len > 65536)
 936                 user_len = 65536;
 937         buffer = dasd_get_user_string(user_buf, user_len);
 938         if (IS_ERR(buffer))
 939                 return PTR_ERR(buffer);
 940
 941         str = skip_spaces(buffer);
 942         rc = user_len;
 943         if (strncmp(str, "reset", 5) == 0) {
 944                 dasd_profile_reset(prof);
 945         } else if (strncmp(str, "on", 2) == 0) {
 946                 rc = dasd_profile_on(prof);
 947                 if (!rc)
 948                         rc = user_len;
 949         } else if (strncmp(str, "off", 3) == 0) {
 950                 dasd_profile_off(prof);
 951         } else
 952                 rc = -EINVAL;
 953         vfree(buffer);
 954         return rc;
 955 }
 956
 957 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 958 {
 959         int i;
 960
 961         for (i = 0; i < 32; i++)
 962                 seq_printf(m, "%u ", array[i]);
 963         seq_putc(m, '\n');
 964 }
 965
 966 static void dasd_stats_seq_print(struct seq_file *m,
 967                                  struct dasd_profile_info *data)
 968 {
 969         seq_printf(m, "start_time %ld.%09ld\n",
 970                    data->starttod.tv_sec, data->starttod.tv_nsec);
 971         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 972         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 973         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 974         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 975         seq_printf(m, "histogram_sectors ");
 976         dasd_stats_array(m, data->dasd_io_secs);
 977         seq_printf(m, "histogram_io_times ");
 978         dasd_stats_array(m, data->dasd_io_times);
 979         seq_printf(m, "histogram_io_times_weighted ");
 980         dasd_stats_array(m, data->dasd_io_timps);
 981         seq_printf(m, "histogram_time_build_to_ssch ");
 982         dasd_stats_array(m, data->dasd_io_time1);
 983         seq_printf(m, "histogram_time_ssch_to_irq ");
 984         dasd_stats_array(m, data->dasd_io_time2);
 985         seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
 986         dasd_stats_array(m, data->dasd_io_time2ps);
 987         seq_printf(m, "histogram_time_irq_to_end ");
 988         dasd_stats_array(m, data->dasd_io_time3);
 989         seq_printf(m, "histogram_ccw_queue_length ");
 990         dasd_stats_array(m, data->dasd_io_nr_req);
 991         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 992         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 993         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 994         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 995         seq_printf(m, "histogram_read_sectors ");
 996         dasd_stats_array(m, data->dasd_read_secs);
 997         seq_printf(m, "histogram_read_times ");
 998         dasd_stats_array(m, data->dasd_read_times);
 999         seq_printf(m, "histogram_read_time_build_to_ssch ");
1000         dasd_stats_array(m, data->dasd_read_time1);
1001         seq_printf(m, "histogram_read_time_ssch_to_irq ");
1002         dasd_stats_array(m, data->dasd_read_time2);
1003         seq_printf(m, "histogram_read_time_irq_to_end ");
1004         dasd_stats_array(m, data->dasd_read_time3);
1005         seq_printf(m, "histogram_read_ccw_queue_length ");
1006         dasd_stats_array(m, data->dasd_read_nr_req);
1007 }
1008
1009 static int dasd_stats_show(struct seq_file *m, void *v)
1010 {
1011         struct dasd_profile *profile;
1012         struct dasd_profile_info *data;
1013
1014         profile = m->private;
1015         spin_lock_bh(&profile->lock);
1016         data = profile->data;
1017         if (!data) {
1018                 spin_unlock_bh(&profile->lock);
1019                 seq_printf(m, "disabled\n");
1020                 return 0;
1021         }
1022         dasd_stats_seq_print(m, data);
1023         spin_unlock_bh(&profile->lock);
1024         return 0;
1025 }
1026
1027 static int dasd_stats_open(struct inode *inode, struct file *file)
1028 {
1029         struct dasd_profile *profile = inode->i_private;
1030         return single_open(file, dasd_stats_show, profile);
1031 }
1032
1033 static const struct file_operations dasd_stats_raw_fops = {
1034         .owner          = THIS_MODULE,
1035         .open           = dasd_stats_open,
1036         .read           = seq_read,
1037         .llseek         = seq_lseek,
1038         .release        = single_release,
1039         .write          = dasd_stats_write,
1040 };
1041
1042 static ssize_t dasd_stats_global_write(struct file *file,
1043                                        const char __user *user_buf,
1044                                        size_t user_len, loff_t *pos)
1045 {
1046         char *buffer, *str;
1047         ssize_t rc;
1048
1049         if (user_len > 65536)
1050                 user_len = 65536;
1051         buffer = dasd_get_user_string(user_buf, user_len);
1052         if (IS_ERR(buffer))
1053                 return PTR_ERR(buffer);
1054         str = skip_spaces(buffer);
1055         rc = user_len;
1056         if (strncmp(str, "reset", 5) == 0) {
1057                 dasd_global_profile_reset();
1058         } else if (strncmp(str, "on", 2) == 0) {
1059                 dasd_global_profile_reset();
1060                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1061         } else if (strncmp(str, "off", 3) == 0) {
1062                 dasd_global_profile_level = DASD_PROFILE_OFF;
1063         } else
1064                 rc = -EINVAL;
1065         vfree(buffer);
1066         return rc;
1067 }
1068
1069 static int dasd_stats_global_show(struct seq_file *m, void *v)
1070 {
1071         if (!dasd_global_profile_level) {
1072                 seq_printf(m, "disabled\n");
1073                 return 0;
1074         }
1075         dasd_stats_seq_print(m, &dasd_global_profile_data);
1076         return 0;
1077 }
1078
1079 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1080 {
1081         return single_open(file, dasd_stats_global_show, NULL);
1082 }
1083
1084 static const struct file_operations dasd_stats_global_fops = {
1085         .owner          = THIS_MODULE,
1086         .open           = dasd_stats_global_open,
1087         .read           = seq_read,
1088         .llseek         = seq_lseek,
1089         .release        = single_release,
1090         .write          = dasd_stats_global_write,
1091 };
1092
1093 static void dasd_profile_init(struct dasd_profile *profile,
1094                               struct dentry *base_dentry)
1095 {
1096         umode_t mode;
1097         struct dentry *pde;
1098
1099         if (!base_dentry)
1100                 return;
1101         profile->dentry = NULL;
1102         profile->data = NULL;
1103         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1104         pde = debugfs_create_file("statistics", mode, base_dentry,
1105                                   profile, &dasd_stats_raw_fops);
1106         if (pde && !IS_ERR(pde))
1107                 profile->dentry = pde;
1108         return;
1109 }
1110
1111 static void dasd_profile_exit(struct dasd_profile *profile)
1112 {
1113         dasd_profile_off(profile);
1114         if (profile->dentry) {
1115                 debugfs_remove(profile->dentry);
1116                 profile->dentry = NULL;
1117         }
1118 }
1119
1120 static void dasd_statistics_removeroot(void)
1121 {
1122         dasd_global_profile_level = DASD_PROFILE_OFF;
1123         if (dasd_global_profile_dentry) {
1124                 debugfs_remove(dasd_global_profile_dentry);
1125                 dasd_global_profile_dentry = NULL;
1126         }
1127         if (dasd_debugfs_global_entry)
1128                 debugfs_remove(dasd_debugfs_global_entry);
1129         if (dasd_debugfs_root_entry)
1130                 debugfs_remove(dasd_debugfs_root_entry);
1131 }
1132
1133 static void dasd_statistics_createroot(void)
1134 {
1135         umode_t mode;
1136         struct dentry *pde;
1137
1138         dasd_debugfs_root_entry = NULL;
1139         dasd_debugfs_global_entry = NULL;
1140         dasd_global_profile_dentry = NULL;
1141         pde = debugfs_create_dir("dasd", NULL);
1142         if (!pde || IS_ERR(pde))
1143                 goto error;
1144         dasd_debugfs_root_entry = pde;
1145         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1146         if (!pde || IS_ERR(pde))
1147                 goto error;
1148         dasd_debugfs_global_entry = pde;
1149
1150         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1151         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1152                                   NULL, &dasd_stats_global_fops);
1153         if (!pde || IS_ERR(pde))
1154                 goto error;
1155         dasd_global_profile_dentry = pde;
1156         return;
1157
1158 error:
1159         DBF_EVENT(DBF_ERR, "%s",
1160                   "Creation of the dasd debugfs interface failed");
1161         dasd_statistics_removeroot();
1162         return;
1163 }
1164
1165 #else
1166 #define dasd_profile_start(block, cqr, req) do {} while (0)
1167 #define dasd_profile_end(block, cqr, req) do {} while (0)
1168
1169 static void dasd_statistics_createroot(void)
1170 {
1171         return;
1172 }
1173
1174 static void dasd_statistics_removeroot(void)
1175 {
1176         return;
1177 }
1178
1179 int dasd_stats_generic_show(struct seq_file *m, void *v)
1180 {
1181         seq_printf(m, "Statistics are not activated in this kernel\n");
1182         return 0;
1183 }
1184
1185 static void dasd_profile_init(struct dasd_profile *profile,
1186                               struct dentry *base_dentry)
1187 {
1188         return;
1189 }
1190
1191 static void dasd_profile_exit(struct dasd_profile *profile)
1192 {
1193         return;
1194 }
1195
1196 int dasd_profile_on(struct dasd_profile *profile)
1197 {
1198         return 0;
1199 }
1200
1201 #endif                          /* CONFIG_DASD_PROFILE */
1202
1203 /*
1204  * Allocate memory for a channel program with 'cplength' channel
1205  * command words and 'datasize' additional space. There are two
1206  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1207  * memory and 2) dasd_smalloc_request uses the static ccw memory
1208  * that gets allocated for each device.
1209  */
1210 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1211                                           int datasize,
1212                                           struct dasd_device *device)
1213 {
1214         struct dasd_ccw_req *cqr;
1215
1216         /* Sanity checks */
1217         BUG_ON(datasize > PAGE_SIZE ||
1218              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1219
1220         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1221         if (cqr == NULL)
1222                 return ERR_PTR(-ENOMEM);
1223         cqr->cpaddr = NULL;
1224         if (cplength > 0) {
1225                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1226                                       GFP_ATOMIC | GFP_DMA);
1227                 if (cqr->cpaddr == NULL) {
1228                         kfree(cqr);
1229                         return ERR_PTR(-ENOMEM);
1230                 }
1231         }
1232         cqr->data = NULL;
1233         if (datasize > 0) {
1234                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1235                 if (cqr->data == NULL) {
1236                         kfree(cqr->cpaddr);
1237                         kfree(cqr);
1238                         return ERR_PTR(-ENOMEM);
1239                 }
1240         }
1241         cqr->magic =  magic;
1242         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1243         dasd_get_device(device);
1244         return cqr;
1245 }
1246
1247 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1248                                           int datasize,
1249                                           struct dasd_device *device)
1250 {
1251         unsigned long flags;
1252         struct dasd_ccw_req *cqr;
1253         char *data;
1254         int size;
1255
1256         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1257         if (cplength > 0)
1258                 size += cplength * sizeof(struct ccw1);
1259         if (datasize > 0)
1260                 size += datasize;
1261         spin_lock_irqsave(&device->mem_lock, flags);
1262         cqr = (struct dasd_ccw_req *)
1263                 dasd_alloc_chunk(&device->ccw_chunks, size);
1264         spin_unlock_irqrestore(&device->mem_lock, flags);
1265         if (cqr == NULL)
1266                 return ERR_PTR(-ENOMEM);
1267         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1268         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1269         cqr->cpaddr = NULL;
1270         if (cplength > 0) {
1271                 cqr->cpaddr = (struct ccw1 *) data;
1272                 data += cplength*sizeof(struct ccw1);
1273                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1274         }
1275         cqr->data = NULL;
1276         if (datasize > 0) {
1277                 cqr->data = data;
1278                 memset(cqr->data, 0, datasize);
1279         }
1280         cqr->magic = magic;
1281         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1282         dasd_get_device(device);
1283         return cqr;
1284 }
1285
1286 /*
1287  * Free memory of a channel program. This function needs to free all the
1288  * idal lists that might have been created by dasd_set_cda and the
1289  * struct dasd_ccw_req itself.
1290  */
1291 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1292 {
1293 #ifdef CONFIG_64BIT
1294         struct ccw1 *ccw;
1295
1296         /* Clear any idals used for the request. */
1297         ccw = cqr->cpaddr;
1298         do {
1299                 clear_normalized_cda(ccw);
1300         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1301 #endif
1302         kfree(cqr->cpaddr);
1303         kfree(cqr->data);
1304         kfree(cqr);
1305         dasd_put_device(device);
1306 }
1307
1308 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1309 {
1310         unsigned long flags;
1311
1312         spin_lock_irqsave(&device->mem_lock, flags);
1313         dasd_free_chunk(&device->ccw_chunks, cqr);
1314         spin_unlock_irqrestore(&device->mem_lock, flags);
1315         dasd_put_device(device);
1316 }
1317
1318 /*
1319  * Check discipline magic in cqr.
1320  */
1321 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1322 {
1323         struct dasd_device *device;
1324
1325         if (cqr == NULL)
1326                 return -EINVAL;
1327         device = cqr->startdev;
1328         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1329                 DBF_DEV_EVENT(DBF_WARNING, device,
1330                             " dasd_ccw_req 0x%08x magic doesn't match"
1331                             " discipline 0x%08x",
1332                             cqr->magic,
1333                             *(unsigned int *) device->discipline->name);
1334                 return -EINVAL;
1335         }
1336         return 0;
1337 }
1338
1339 /*
1340  * Terminate the current i/o and set the request to clear_pending.
1341  * Timer keeps device runnig.
1342  * ccw_device_clear can fail if the i/o subsystem
1343  * is in a bad mood.
1344  */
1345 int dasd_term_IO(struct dasd_ccw_req *cqr)
1346 {
1347         struct dasd_device *device;
1348         int retries, rc;
1349         char errorstring[ERRORLENGTH];
1350
1351         /* Check the cqr */
1352         rc = dasd_check_cqr(cqr);
1353         if (rc)
1354                 return rc;
1355         retries = 0;
1356         device = (struct dasd_device *) cqr->startdev;
1357         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1358                 rc = ccw_device_clear(device->cdev, (long) cqr);
1359                 switch (rc) {
1360                 case 0: /* termination successful */
1361                         cqr->status = DASD_CQR_CLEAR_PENDING;
1362                         cqr->stopclk = get_tod_clock();
1363                         cqr->starttime = 0;
1364                         DBF_DEV_EVENT(DBF_DEBUG, device,
1365                                       "terminate cqr %p successful",
1366                                       cqr);
1367                         break;
1368                 case -ENODEV:
1369                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1370                                       "device gone, retry");
1371                         break;
1372                 case -EIO:
1373                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1374                                       "I/O error, retry");
1375                         break;
1376                 case -EINVAL:
1377                 case -EBUSY:
1378                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1379                                       "device busy, retry later");
1380                         break;
1381                 default:
1382                         /* internal error 10 - unknown rc*/
1383                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1384                         dev_err(&device->cdev->dev, "An error occurred in the "
1385                                 "DASD device driver, reason=%s\n", errorstring);
1386                         BUG();
1387                         break;
1388                 }
1389                 retries++;
1390         }
1391         dasd_schedule_device_bh(device);
1392         return rc;
1393 }
1394
1395 /*
1396  * Start the i/o. This start_IO can fail if the channel is really busy.
1397  * In that case set up a timer to start the request later.
1398  */
1399 int dasd_start_IO(struct dasd_ccw_req *cqr)
1400 {
1401         struct dasd_device *device;
1402         int rc;
1403         char errorstring[ERRORLENGTH];
1404
1405         /* Check the cqr */
1406         rc = dasd_check_cqr(cqr);
1407         if (rc) {
1408                 cqr->intrc = rc;
1409                 return rc;
1410         }
1411         device = (struct dasd_device *) cqr->startdev;
1412         if (((cqr->block &&
1413               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1414              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1415             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1416                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1417                               "because of stolen lock", cqr);
1418                 cqr->status = DASD_CQR_ERROR;
1419                 cqr->intrc = -EPERM;
1420                 return -EPERM;
1421         }
1422         if (cqr->retries < 0) {
1423                 /* internal error 14 - start_IO run out of retries */
1424                 sprintf(errorstring, "14 %p", cqr);
1425                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1426                         "device driver, reason=%s\n", errorstring);
1427                 cqr->status = DASD_CQR_ERROR;
1428                 return -EIO;
1429         }
1430         cqr->startclk = get_tod_clock();
1431         cqr->starttime = jiffies;
1432         cqr->retries--;
1433         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1434                 cqr->lpm &= device->path_data.opm;
1435                 if (!cqr->lpm)
1436                         cqr->lpm = device->path_data.opm;
1437         }
1438         if (cqr->cpmode == 1) {
1439                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1440                                          (long) cqr, cqr->lpm);
1441         } else {
1442                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1443                                       (long) cqr, cqr->lpm, 0);
1444         }
1445         switch (rc) {
1446         case 0:
1447                 cqr->status = DASD_CQR_IN_IO;
1448                 break;
1449         case -EBUSY:
1450                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1451                               "start_IO: device busy, retry later");
1452                 break;
1453         case -ETIMEDOUT:
1454                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1455                               "start_IO: request timeout, retry later");
1456                 break;
1457         case -EACCES:
1458                 /* -EACCES indicates that the request used only a subset of the
1459                  * available paths and all these paths are gone. If the lpm of
1460                  * this request was only a subset of the opm (e.g. the ppm) then
1461                  * we just do a retry with all available paths.
1462                  * If we already use the full opm, something is amiss, and we
1463                  * need a full path verification.
1464                  */
1465                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1466                         DBF_DEV_EVENT(DBF_WARNING, device,
1467                                       "start_IO: selected paths gone (%x)",
1468                                       cqr->lpm);
1469                 } else if (cqr->lpm != device->path_data.opm) {
1470                         cqr->lpm = device->path_data.opm;
1471                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1472                                       "start_IO: selected paths gone,"
1473                                       " retry on all paths");
1474                 } else {
1475                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1476                                       "start_IO: all paths in opm gone,"
1477                                       " do path verification");
1478                         dasd_generic_last_path_gone(device);
1479                         device->path_data.opm = 0;
1480                         device->path_data.ppm = 0;
1481                         device->path_data.npm = 0;
1482                         device->path_data.tbvpm =
1483                                 ccw_device_get_path_mask(device->cdev);
1484                 }
1485                 break;
1486         case -ENODEV:
1487                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1488                               "start_IO: -ENODEV device gone, retry");
1489                 break;
1490         case -EIO:
1491                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1492                               "start_IO: -EIO device gone, retry");
1493                 break;
1494         case -EINVAL:
1495                 /* most likely caused in power management context */
1496                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1497                               "start_IO: -EINVAL device currently "
1498                               "not accessible");
1499                 break;
1500         default:
1501                 /* internal error 11 - unknown rc */
1502                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1503                 dev_err(&device->cdev->dev,
1504                         "An error occurred in the DASD device driver, "
1505                         "reason=%s\n", errorstring);
1506                 BUG();
1507                 break;
1508         }
1509         cqr->intrc = rc;
1510         return rc;
1511 }
1512
1513 /*
1514  * Timeout function for dasd devices. This is used for different purposes
1515  *  1) missing interrupt handler for normal operation
1516  *  2) delayed start of request where start_IO failed with -EBUSY
1517  *  3) timeout for missing state change interrupts
1518  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1519  * DASD_CQR_QUEUED for 2) and 3).
1520  */
1521 static void dasd_device_timeout(unsigned long ptr)
1522 {
1523         unsigned long flags;
1524         struct dasd_device *device;
1525
1526         device = (struct dasd_device *) ptr;
1527         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1528         /* re-activate request queue */
1529         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1530         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1531         dasd_schedule_device_bh(device);
1532 }
1533
1534 /*
1535  * Setup timeout for a device in jiffies.
1536  */
1537 void dasd_device_set_timer(struct dasd_device *device, int expires)
1538 {
1539         if (expires == 0)
1540                 del_timer(&device->timer);
1541         else
1542                 mod_timer(&device->timer, jiffies + expires);
1543 }
1544
1545 /*
1546  * Clear timeout for a device.
1547  */
1548 void dasd_device_clear_timer(struct dasd_device *device)
1549 {
1550         del_timer(&device->timer);
1551 }
1552
1553 static void dasd_handle_killed_request(struct ccw_device *cdev,
1554                                        unsigned long intparm)
1555 {
1556         struct dasd_ccw_req *cqr;
1557         struct dasd_device *device;
1558
1559         if (!intparm)
1560                 return;
1561         cqr = (struct dasd_ccw_req *) intparm;
1562         if (cqr->status != DASD_CQR_IN_IO) {
1563                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1564                                 "invalid status in handle_killed_request: "
1565                                 "%02x", cqr->status);
1566                 return;
1567         }
1568
1569         device = dasd_device_from_cdev_locked(cdev);
1570         if (IS_ERR(device)) {
1571                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1572                                 "unable to get device from cdev");
1573                 return;
1574         }
1575
1576         if (!cqr->startdev ||
1577             device != cqr->startdev ||
1578             strncmp(cqr->startdev->discipline->ebcname,
1579                     (char *) &cqr->magic, 4)) {
1580                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1581                                 "invalid device in request");
1582                 dasd_put_device(device);
1583                 return;
1584         }
1585
1586         /* Schedule request to be retried. */
1587         cqr->status = DASD_CQR_QUEUED;
1588
1589         dasd_device_clear_timer(device);
1590         dasd_schedule_device_bh(device);
1591         dasd_put_device(device);
1592 }
1593
1594 void dasd_generic_handle_state_change(struct dasd_device *device)
1595 {
1596         /* First of all start sense subsystem status request. */
1597         dasd_eer_snss(device);
1598
1599         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1600         dasd_schedule_device_bh(device);
1601         if (device->block)
1602                 dasd_schedule_block_bh(device->block);
1603 }
1604
1605 /*
1606  * Interrupt handler for "normal" ssch-io based dasd devices.
1607  */
1608 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1609                       struct irb *irb)
1610 {
1611         struct dasd_ccw_req *cqr, *next;
1612         struct dasd_device *device;
1613         unsigned long long now;
1614         int expires;
1615
1616         if (IS_ERR(irb)) {
1617                 switch (PTR_ERR(irb)) {
1618                 case -EIO:
1619                         break;
1620                 case -ETIMEDOUT:
1621                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1622                                         "request timed out\n", __func__);
1623                         break;
1624                 default:
1625                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1626                                         "unknown error %ld\n", __func__,
1627                                         PTR_ERR(irb));
1628                 }
1629                 dasd_handle_killed_request(cdev, intparm);
1630                 return;
1631         }
1632
1633         now = get_tod_clock();
1634         cqr = (struct dasd_ccw_req *) intparm;
1635         /* check for conditions that should be handled immediately */
1636         if (!cqr ||
1637             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1638               scsw_cstat(&irb->scsw) == 0)) {
1639                 if (cqr)
1640                         memcpy(&cqr->irb, irb, sizeof(*irb));
1641                 device = dasd_device_from_cdev_locked(cdev);
1642                 if (IS_ERR(device))
1643                         return;
1644                 /* ignore unsolicited interrupts for DIAG discipline */
1645                 if (device->discipline == dasd_diag_discipline_pointer) {
1646                         dasd_put_device(device);
1647                         return;
1648                 }
1649                 device->discipline->dump_sense_dbf(device, irb, "int");
1650                 if (device->features & DASD_FEATURE_ERPLOG)
1651                         device->discipline->dump_sense(device, cqr, irb);
1652                 device->discipline->check_for_device_change(device, cqr, irb);
1653                 dasd_put_device(device);
1654         }
1655         if (!cqr)
1656                 return;
1657
1658         device = (struct dasd_device *) cqr->startdev;
1659         if (!device ||
1660             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1661                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1662                                 "invalid device in request");
1663                 return;
1664         }
1665
1666         /* Check for clear pending */
1667         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1668             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1669                 cqr->status = DASD_CQR_CLEARED;
1670                 dasd_device_clear_timer(device);
1671                 wake_up(&dasd_flush_wq);
1672                 dasd_schedule_device_bh(device);
1673                 return;
1674         }
1675
1676         /* check status - the request might have been killed by dyn detach */
1677         if (cqr->status != DASD_CQR_IN_IO) {
1678                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1679                               "status %02x", dev_name(&cdev->dev), cqr->status);
1680                 return;
1681         }
1682
1683         next = NULL;
1684         expires = 0;
1685         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1686             scsw_cstat(&irb->scsw) == 0) {
1687                 /* request was completed successfully */
1688                 cqr->status = DASD_CQR_SUCCESS;
1689                 cqr->stopclk = now;
1690                 /* Start first request on queue if possible -> fast_io. */
1691                 if (cqr->devlist.next != &device->ccw_queue) {
1692                         next = list_entry(cqr->devlist.next,
1693                                           struct dasd_ccw_req, devlist);
1694                 }
1695         } else {  /* error */
1696                 /*
1697                  * If we don't want complex ERP for this request, then just
1698                  * reset this and retry it in the fastpath
1699                  */
1700                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1701                     cqr->retries > 0) {
1702                         if (cqr->lpm == device->path_data.opm)
1703                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1704                                               "default ERP in fastpath "
1705                                               "(%i retries left)",
1706                                               cqr->retries);
1707                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1708                                 cqr->lpm = device->path_data.opm;
1709                         cqr->status = DASD_CQR_QUEUED;
1710                         next = cqr;
1711                 } else
1712                         cqr->status = DASD_CQR_ERROR;
1713         }
1714         if (next && (next->status == DASD_CQR_QUEUED) &&
1715             (!device->stopped)) {
1716                 if (device->discipline->start_IO(next) == 0)
1717                         expires = next->expires;
1718         }
1719         if (expires != 0)
1720                 dasd_device_set_timer(device, expires);
1721         else
1722                 dasd_device_clear_timer(device);
1723         dasd_schedule_device_bh(device);
1724 }
1725
1726 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1727 {
1728         struct dasd_device *device;
1729
1730         device = dasd_device_from_cdev_locked(cdev);
1731
1732         if (IS_ERR(device))
1733                 goto out;
1734         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1735            device->state != device->target ||
1736            !device->discipline->check_for_device_change){
1737                 dasd_put_device(device);
1738                 goto out;
1739         }
1740         if (device->discipline->dump_sense_dbf)
1741                 device->discipline->dump_sense_dbf(device, irb, "uc");
1742         device->discipline->check_for_device_change(device, NULL, irb);
1743         dasd_put_device(device);
1744 out:
1745         return UC_TODO_RETRY;
1746 }
1747 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1748
1749 /*
1750  * If we have an error on a dasd_block layer request then we cancel
1751  * and return all further requests from the same dasd_block as well.
1752  */
1753 static void __dasd_device_recovery(struct dasd_device *device,
1754                                    struct dasd_ccw_req *ref_cqr)
1755 {
1756         struct list_head *l, *n;
1757         struct dasd_ccw_req *cqr;
1758
1759         /*
1760          * only requeue request that came from the dasd_block layer
1761          */
1762         if (!ref_cqr->block)
1763                 return;
1764
1765         list_for_each_safe(l, n, &device->ccw_queue) {
1766                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1767                 if (cqr->status == DASD_CQR_QUEUED &&
1768                     ref_cqr->block == cqr->block) {
1769                         cqr->status = DASD_CQR_CLEARED;
1770                 }
1771         }
1772 };
1773
1774 /*
1775  * Remove those ccw requests from the queue that need to be returned
1776  * to the upper layer.
1777  */
1778 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1779                                             struct list_head *final_queue)
1780 {
1781         struct list_head *l, *n;
1782         struct dasd_ccw_req *cqr;
1783
1784         /* Process request with final status. */
1785         list_for_each_safe(l, n, &device->ccw_queue) {
1786                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1787
1788                 /* Skip any non-final request. */
1789                 if (cqr->status == DASD_CQR_QUEUED ||
1790                     cqr->status == DASD_CQR_IN_IO ||
1791                     cqr->status == DASD_CQR_CLEAR_PENDING)
1792                         continue;
1793                 if (cqr->status == DASD_CQR_ERROR) {
1794                         __dasd_device_recovery(device, cqr);
1795                 }
1796                 /* Rechain finished requests to final queue */
1797                 list_move_tail(&cqr->devlist, final_queue);
1798         }
1799 }
1800
1801 /*
1802  * the cqrs from the final queue are returned to the upper layer
1803  * by setting a dasd_block state and calling the callback function
1804  */
1805 static void __dasd_device_process_final_queue(struct dasd_device *device,
1806                                               struct list_head *final_queue)
1807 {
1808         struct list_head *l, *n;
1809         struct dasd_ccw_req *cqr;
1810         struct dasd_block *block;
1811         void (*callback)(struct dasd_ccw_req *, void *data);
1812         void *callback_data;
1813         char errorstring[ERRORLENGTH];
1814
1815         list_for_each_safe(l, n, final_queue) {
1816                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1817                 list_del_init(&cqr->devlist);
1818                 block = cqr->block;
1819                 callback = cqr->callback;
1820                 callback_data = cqr->callback_data;
1821                 if (block)
1822                         spin_lock_bh(&block->queue_lock);
1823                 switch (cqr->status) {
1824                 case DASD_CQR_SUCCESS:
1825                         cqr->status = DASD_CQR_DONE;
1826                         break;
1827                 case DASD_CQR_ERROR:
1828                         cqr->status = DASD_CQR_NEED_ERP;
1829                         break;
1830                 case DASD_CQR_CLEARED:
1831                         cqr->status = DASD_CQR_TERMINATED;
1832                         break;
1833                 default:
1834                         /* internal error 12 - wrong cqr status*/
1835                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1836                         dev_err(&device->cdev->dev,
1837                                 "An error occurred in the DASD device driver, "
1838                                 "reason=%s\n", errorstring);
1839                         BUG();
1840                 }
1841                 if (cqr->callback != NULL)
1842                         (callback)(cqr, callback_data);
1843                 if (block)
1844                         spin_unlock_bh(&block->queue_lock);
1845         }
1846 }
1847
1848 /*
1849  * Take a look at the first request on the ccw queue and check
1850  * if it reached its expire time. If so, terminate the IO.
1851  */
1852 static void __dasd_device_check_expire(struct dasd_device *device)
1853 {
1854         struct dasd_ccw_req *cqr;
1855
1856         if (list_empty(&device->ccw_queue))
1857                 return;
1858         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1859         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1860             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1861                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1862                         /*
1863                          * IO in safe offline processing should not
1864                          * run out of retries
1865                          */
1866                         cqr->retries++;
1867                 }
1868                 if (device->discipline->term_IO(cqr) != 0) {
1869                         /* Hmpf, try again in 5 sec */
1870                         dev_err(&device->cdev->dev,
1871                                 "cqr %p timed out (%lus) but cannot be "
1872                                 "ended, retrying in 5 s\n",
1873                                 cqr, (cqr->expires/HZ));
1874                         cqr->expires += 5*HZ;
1875                         dasd_device_set_timer(device, 5*HZ);
1876                 } else {
1877                         dev_err(&device->cdev->dev,
1878                                 "cqr %p timed out (%lus), %i retries "
1879                                 "remaining\n", cqr, (cqr->expires/HZ),
1880                                 cqr->retries);
1881                 }
1882         }
1883 }
1884
1885 /*
1886  * Take a look at the first request on the ccw queue and check
1887  * if it needs to be started.
1888  */
1889 static void __dasd_device_start_head(struct dasd_device *device)
1890 {
1891         struct dasd_ccw_req *cqr;
1892         int rc;
1893
1894         if (list_empty(&device->ccw_queue))
1895                 return;
1896         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1897         if (cqr->status != DASD_CQR_QUEUED)
1898                 return;
1899         /* when device is stopped, return request to previous layer
1900          * exception: only the disconnect or unresumed bits are set and the
1901          * cqr is a path verification request
1902          */
1903         if (device->stopped &&
1904             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1905               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1906                 cqr->intrc = -EAGAIN;
1907                 cqr->status = DASD_CQR_CLEARED;
1908                 dasd_schedule_device_bh(device);
1909                 return;
1910         }
1911
1912         rc = device->discipline->start_IO(cqr);
1913         if (rc == 0)
1914                 dasd_device_set_timer(device, cqr->expires);
1915         else if (rc == -EACCES) {
1916                 dasd_schedule_device_bh(device);
1917         } else
1918                 /* Hmpf, try again in 1/2 sec */
1919                 dasd_device_set_timer(device, 50);
1920 }
1921
1922 static void __dasd_device_check_path_events(struct dasd_device *device)
1923 {
1924         int rc;
1925
1926         if (device->path_data.tbvpm) {
1927                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1928                                         DASD_UNRESUMED_PM))
1929                         return;
1930                 rc = device->discipline->verify_path(
1931                         device, device->path_data.tbvpm);
1932                 if (rc)
1933                         dasd_device_set_timer(device, 50);
1934                 else
1935                         device->path_data.tbvpm = 0;
1936         }
1937 };
1938
1939 /*
1940  * Go through all request on the dasd_device request queue,
1941  * terminate them on the cdev if necessary, and return them to the
1942  * submitting layer via callback.
1943  * Note:
1944  * Make sure that all 'submitting layers' still exist when
1945  * this function is called!. In other words, when 'device' is a base
1946  * device then all block layer requests must have been removed before
1947  * via dasd_flush_block_queue.
1948  */
1949 int dasd_flush_device_queue(struct dasd_device *device)
1950 {
1951         struct dasd_ccw_req *cqr, *n;
1952         int rc;
1953         struct list_head flush_queue;
1954
1955         INIT_LIST_HEAD(&flush_queue);
1956         spin_lock_irq(get_ccwdev_lock(device->cdev));
1957         rc = 0;
1958         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1959                 /* Check status and move request to flush_queue */
1960                 switch (cqr->status) {
1961                 case DASD_CQR_IN_IO:
1962                         rc = device->discipline->term_IO(cqr);
1963                         if (rc) {
1964                                 /* unable to terminate requeust */
1965                                 dev_err(&device->cdev->dev,
1966                                         "Flushing the DASD request queue "
1967                                         "failed for request %p\n", cqr);
1968                                 /* stop flush processing */
1969                                 goto finished;
1970                         }
1971                         break;
1972                 case DASD_CQR_QUEUED:
1973                         cqr->stopclk = get_tod_clock();
1974                         cqr->status = DASD_CQR_CLEARED;
1975                         break;
1976                 default: /* no need to modify the others */
1977                         break;
1978                 }
1979                 list_move_tail(&cqr->devlist, &flush_queue);
1980         }
1981 finished:
1982         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1983         /*
1984          * After this point all requests must be in state CLEAR_PENDING,
1985          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1986          * one of the others.
1987          */
1988         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1989                 wait_event(dasd_flush_wq,
1990                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1991         /*
1992          * Now set each request back to TERMINATED, DONE or NEED_ERP
1993          * and call the callback function of flushed requests
1994          */
1995         __dasd_device_process_final_queue(device, &flush_queue);
1996         return rc;
1997 }
1998
1999 /*
2000  * Acquire the device lock and process queues for the device.
2001  */
2002 static void dasd_device_tasklet(struct dasd_device *device)
2003 {
2004         struct list_head final_queue;
2005
2006         atomic_set (&device->tasklet_scheduled, 0);
2007         INIT_LIST_HEAD(&final_queue);
2008         spin_lock_irq(get_ccwdev_lock(device->cdev));
2009         /* Check expire time of first request on the ccw queue. */
2010         __dasd_device_check_expire(device);
2011         /* find final requests on ccw queue */
2012         __dasd_device_process_ccw_queue(device, &final_queue);
2013         __dasd_device_check_path_events(device);
2014         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2015         /* Now call the callback function of requests with final status */
2016         __dasd_device_process_final_queue(device, &final_queue);
2017         spin_lock_irq(get_ccwdev_lock(device->cdev));
2018         /* Now check if the head of the ccw queue needs to be started. */
2019         __dasd_device_start_head(device);
2020         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2021         if (waitqueue_active(&shutdown_waitq))
2022                 wake_up(&shutdown_waitq);
2023         dasd_put_device(device);
2024 }
2025
2026 /*
2027  * Schedules a call to dasd_tasklet over the device tasklet.
2028  */
2029 void dasd_schedule_device_bh(struct dasd_device *device)
2030 {
2031         /* Protect against rescheduling. */
2032         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2033                 return;
2034         dasd_get_device(device);
2035         tasklet_hi_schedule(&device->tasklet);
2036 }
2037
2038 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2039 {
2040         device->stopped |= bits;
2041 }
2042 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2043
2044 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2045 {
2046         device->stopped &= ~bits;
2047         if (!device->stopped)
2048                 wake_up(&generic_waitq);
2049 }
2050 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2051
2052 /*
2053  * Queue a request to the head of the device ccw_queue.
2054  * Start the I/O if possible.
2055  */
2056 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2057 {
2058         struct dasd_device *device;
2059         unsigned long flags;
2060
2061         device = cqr->startdev;
2062         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2063         cqr->status = DASD_CQR_QUEUED;
2064         list_add(&cqr->devlist, &device->ccw_queue);
2065         /* let the bh start the request to keep them in order */
2066         dasd_schedule_device_bh(device);
2067         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2068 }
2069
2070 /*
2071  * Queue a request to the tail of the device ccw_queue.
2072  * Start the I/O if possible.
2073  */
2074 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2075 {
2076         struct dasd_device *device;
2077         unsigned long flags;
2078
2079         device = cqr->startdev;
2080         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2081         cqr->status = DASD_CQR_QUEUED;
2082         list_add_tail(&cqr->devlist, &device->ccw_queue);
2083         /* let the bh start the request to keep them in order */
2084         dasd_schedule_device_bh(device);
2085         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2086 }
2087
2088 /*
2089  * Wakeup helper for the 'sleep_on' functions.
2090  */
2091 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2092 {
2093         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2094         cqr->callback_data = DASD_SLEEPON_END_TAG;
2095         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2096         wake_up(&generic_waitq);
2097 }
2098 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2099
2100 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2101 {
2102         struct dasd_device *device;
2103         int rc;
2104
2105         device = cqr->startdev;
2106         spin_lock_irq(get_ccwdev_lock(device->cdev));
2107         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2108         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2109         return rc;
2110 }
2111
2112 /*
2113  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2114  */
2115 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2116 {
2117         struct dasd_device *device;
2118         dasd_erp_fn_t erp_fn;
2119
2120         if (cqr->status == DASD_CQR_FILLED)
2121                 return 0;
2122         device = cqr->startdev;
2123         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2124                 if (cqr->status == DASD_CQR_TERMINATED) {
2125                         device->discipline->handle_terminated_request(cqr);
2126                         return 1;
2127                 }
2128                 if (cqr->status == DASD_CQR_NEED_ERP) {
2129                         erp_fn = device->discipline->erp_action(cqr);
2130                         erp_fn(cqr);
2131                         return 1;
2132                 }
2133                 if (cqr->status == DASD_CQR_FAILED)
2134                         dasd_log_sense(cqr, &cqr->irb);
2135                 if (cqr->refers) {
2136                         __dasd_process_erp(device, cqr);
2137                         return 1;
2138                 }
2139         }
2140         return 0;
2141 }
2142
2143 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2144 {
2145         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2146                 if (cqr->refers) /* erp is not done yet */
2147                         return 1;
2148                 return ((cqr->status != DASD_CQR_DONE) &&
2149                         (cqr->status != DASD_CQR_FAILED));
2150         } else
2151                 return (cqr->status == DASD_CQR_FILLED);
2152 }
2153
2154 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2155 {
2156         struct dasd_device *device;
2157         int rc;
2158         struct list_head ccw_queue;
2159         struct dasd_ccw_req *cqr;
2160
2161         INIT_LIST_HEAD(&ccw_queue);
2162         maincqr->status = DASD_CQR_FILLED;
2163         device = maincqr->startdev;
2164         list_add(&maincqr->blocklist, &ccw_queue);
2165         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2166              cqr = list_first_entry(&ccw_queue,
2167                                     struct dasd_ccw_req, blocklist)) {
2168
2169                 if (__dasd_sleep_on_erp(cqr))
2170                         continue;
2171                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2172                         continue;
2173                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2174                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2175                         cqr->status = DASD_CQR_FAILED;
2176                         cqr->intrc = -EPERM;
2177                         continue;
2178                 }
2179                 /* Non-temporary stop condition will trigger fail fast */
2180                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2181                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2182                     (!dasd_eer_enabled(device))) {
2183                         cqr->status = DASD_CQR_FAILED;
2184                         cqr->intrc = -ENOLINK;
2185                         continue;
2186                 }
2187                 /* Don't try to start requests if device is stopped */
2188                 if (interruptible) {
2189                         rc = wait_event_interruptible(
2190                                 generic_waitq, !(device->stopped));
2191                         if (rc == -ERESTARTSYS) {
2192                                 cqr->status = DASD_CQR_FAILED;
2193                                 maincqr->intrc = rc;
2194                                 continue;
2195                         }
2196                 } else
2197                         wait_event(generic_waitq, !(device->stopped));
2198
2199                 if (!cqr->callback)
2200                         cqr->callback = dasd_wakeup_cb;
2201
2202                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2203                 dasd_add_request_tail(cqr);
2204                 if (interruptible) {
2205                         rc = wait_event_interruptible(
2206                                 generic_waitq, _wait_for_wakeup(cqr));
2207                         if (rc == -ERESTARTSYS) {
2208                                 dasd_cancel_req(cqr);
2209                                 /* wait (non-interruptible) for final status */
2210                                 wait_event(generic_waitq,
2211                                            _wait_for_wakeup(cqr));
2212                                 cqr->status = DASD_CQR_FAILED;
2213                                 maincqr->intrc = rc;
2214                                 continue;
2215                         }
2216                 } else
2217                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2218         }
2219
2220         maincqr->endclk = get_tod_clock();
2221         if ((maincqr->status != DASD_CQR_DONE) &&
2222             (maincqr->intrc != -ERESTARTSYS))
2223                 dasd_log_sense(maincqr, &maincqr->irb);
2224         if (maincqr->status == DASD_CQR_DONE)
2225                 rc = 0;
2226         else if (maincqr->intrc)
2227                 rc = maincqr->intrc;
2228         else
2229                 rc = -EIO;
2230         return rc;
2231 }
2232
2233 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2234 {
2235         struct dasd_ccw_req *cqr;
2236
2237         list_for_each_entry(cqr, ccw_queue, blocklist) {
2238                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2239                         return 0;
2240         }
2241
2242         return 1;
2243 }
2244
2245 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2246 {
2247         struct dasd_device *device;
2248         int rc;
2249         struct dasd_ccw_req *cqr, *n;
2250
2251 retry:
2252         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2253                 device = cqr->startdev;
2254                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2255                         continue;
2256
2257                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2258                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2259                         cqr->status = DASD_CQR_FAILED;
2260                         cqr->intrc = -EPERM;
2261                         continue;
2262                 }
2263                 /*Non-temporary stop condition will trigger fail fast*/
2264                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2265                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2266                     !dasd_eer_enabled(device)) {
2267                         cqr->status = DASD_CQR_FAILED;
2268                         cqr->intrc = -EAGAIN;
2269                         continue;
2270                 }
2271
2272                 /*Don't try to start requests if device is stopped*/
2273                 if (interruptible) {
2274                         rc = wait_event_interruptible(
2275                                 generic_waitq, !device->stopped);
2276                         if (rc == -ERESTARTSYS) {
2277                                 cqr->status = DASD_CQR_FAILED;
2278                                 cqr->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                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2287                 dasd_add_request_tail(cqr);
2288         }
2289
2290         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2291
2292         rc = 0;
2293         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2294                 if (__dasd_sleep_on_erp(cqr))
2295                         rc = 1;
2296         }
2297         if (rc)
2298                 goto retry;
2299
2300
2301         return 0;
2302 }
2303
2304 /*
2305  * Queue a request to the tail of the device ccw_queue and wait for
2306  * it's completion.
2307  */
2308 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2309 {
2310         return _dasd_sleep_on(cqr, 0);
2311 }
2312
2313 /*
2314  * Start requests from a ccw_queue and wait for their completion.
2315  */
2316 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2317 {
2318         return _dasd_sleep_on_queue(ccw_queue, 0);
2319 }
2320 EXPORT_SYMBOL(dasd_sleep_on_queue);
2321
2322 /*
2323  * Queue a request to the tail of the device ccw_queue and wait
2324  * interruptible for it's completion.
2325  */
2326 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2327 {
2328         return _dasd_sleep_on(cqr, 1);
2329 }
2330
2331 /*
2332  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2333  * for eckd devices) the currently running request has to be terminated
2334  * and be put back to status queued, before the special request is added
2335  * to the head of the queue. Then the special request is waited on normally.
2336  */
2337 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2338 {
2339         struct dasd_ccw_req *cqr;
2340         int rc;
2341
2342         if (list_empty(&device->ccw_queue))
2343                 return 0;
2344         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2345         rc = device->discipline->term_IO(cqr);
2346         if (!rc)
2347                 /*
2348                  * CQR terminated because a more important request is pending.
2349                  * Undo decreasing of retry counter because this is
2350                  * not an error case.
2351                  */
2352                 cqr->retries++;
2353         return rc;
2354 }
2355
2356 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2357 {
2358         struct dasd_device *device;
2359         int rc;
2360
2361         device = cqr->startdev;
2362         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2363             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2364                 cqr->status = DASD_CQR_FAILED;
2365                 cqr->intrc = -EPERM;
2366                 return -EIO;
2367         }
2368         spin_lock_irq(get_ccwdev_lock(device->cdev));
2369         rc = _dasd_term_running_cqr(device);
2370         if (rc) {
2371                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2372                 return rc;
2373         }
2374         cqr->callback = dasd_wakeup_cb;
2375         cqr->callback_data = DASD_SLEEPON_START_TAG;
2376         cqr->status = DASD_CQR_QUEUED;
2377         /*
2378          * add new request as second
2379          * first the terminated cqr needs to be finished
2380          */
2381         list_add(&cqr->devlist, device->ccw_queue.next);
2382
2383         /* let the bh start the request to keep them in order */
2384         dasd_schedule_device_bh(device);
2385
2386         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2387
2388         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2389
2390         if (cqr->status == DASD_CQR_DONE)
2391                 rc = 0;
2392         else if (cqr->intrc)
2393                 rc = cqr->intrc;
2394         else
2395                 rc = -EIO;
2396
2397         /* kick tasklets */
2398         dasd_schedule_device_bh(device);
2399         if (device->block)
2400                 dasd_schedule_block_bh(device->block);
2401
2402         return rc;
2403 }
2404
2405 /*
2406  * Cancels a request that was started with dasd_sleep_on_req.
2407  * This is useful to timeout requests. The request will be
2408  * terminated if it is currently in i/o.
2409  * Returns 0 if request termination was successful
2410  *         negative error code if termination failed
2411  * Cancellation of a request is an asynchronous operation! The calling
2412  * function has to wait until the request is properly returned via callback.
2413  */
2414 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2415 {
2416         struct dasd_device *device = cqr->startdev;
2417         unsigned long flags;
2418         int rc;
2419
2420         rc = 0;
2421         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2422         switch (cqr->status) {
2423         case DASD_CQR_QUEUED:
2424                 /* request was not started - just set to cleared */
2425                 cqr->status = DASD_CQR_CLEARED;
2426                 break;
2427         case DASD_CQR_IN_IO:
2428                 /* request in IO - terminate IO and release again */
2429                 rc = device->discipline->term_IO(cqr);
2430                 if (rc) {
2431                         dev_err(&device->cdev->dev,
2432                                 "Cancelling request %p failed with rc=%d\n",
2433                                 cqr, rc);
2434                 } else {
2435                         cqr->stopclk = get_tod_clock();
2436                 }
2437                 break;
2438         default: /* already finished or clear pending - do nothing */
2439                 break;
2440         }
2441         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2442         dasd_schedule_device_bh(device);
2443         return rc;
2444 }
2445
2446 /*
2447  * SECTION: Operations of the dasd_block layer.
2448  */
2449
2450 /*
2451  * Timeout function for dasd_block. This is used when the block layer
2452  * is waiting for something that may not come reliably, (e.g. a state
2453  * change interrupt)
2454  */
2455 static void dasd_block_timeout(unsigned long ptr)
2456 {
2457         unsigned long flags;
2458         struct dasd_block *block;
2459
2460         block = (struct dasd_block *) ptr;
2461         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2462         /* re-activate request queue */
2463         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2464         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2465         dasd_schedule_block_bh(block);
2466 }
2467
2468 /*
2469  * Setup timeout for a dasd_block in jiffies.
2470  */
2471 void dasd_block_set_timer(struct dasd_block *block, int expires)
2472 {
2473         if (expires == 0)
2474                 del_timer(&block->timer);
2475         else
2476                 mod_timer(&block->timer, jiffies + expires);
2477 }
2478
2479 /*
2480  * Clear timeout for a dasd_block.
2481  */
2482 void dasd_block_clear_timer(struct dasd_block *block)
2483 {
2484         del_timer(&block->timer);
2485 }
2486
2487 /*
2488  * Process finished error recovery ccw.
2489  */
2490 static void __dasd_process_erp(struct dasd_device *device,
2491                                struct dasd_ccw_req *cqr)
2492 {
2493         dasd_erp_fn_t erp_fn;
2494
2495         if (cqr->status == DASD_CQR_DONE)
2496                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2497         else
2498                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2499         erp_fn = device->discipline->erp_postaction(cqr);
2500         erp_fn(cqr);
2501 }
2502
2503 /*
2504  * Fetch requests from the block device queue.
2505  */
2506 static void __dasd_process_request_queue(struct dasd_block *block)
2507 {
2508         struct request_queue *queue;
2509         struct request *req;
2510         struct dasd_ccw_req *cqr;
2511         struct dasd_device *basedev;
2512         unsigned long flags;
2513         queue = block->request_queue;
2514         basedev = block->base;
2515         /* No queue ? Then there is nothing to do. */
2516         if (queue == NULL)
2517                 return;
2518
2519         /*
2520          * We requeue request from the block device queue to the ccw
2521          * queue only in two states. In state DASD_STATE_READY the
2522          * partition detection is done and we need to requeue requests
2523          * for that. State DASD_STATE_ONLINE is normal block device
2524          * operation.
2525          */
2526         if (basedev->state < DASD_STATE_READY) {
2527                 while ((req = blk_fetch_request(block->request_queue)))
2528                         __blk_end_request_all(req, -EIO);
2529                 return;
2530         }
2531         /* Now we try to fetch requests from the request queue */
2532         while ((req = blk_peek_request(queue))) {
2533                 if (basedev->features & DASD_FEATURE_READONLY &&
2534                     rq_data_dir(req) == WRITE) {
2535                         DBF_DEV_EVENT(DBF_ERR, basedev,
2536                                       "Rejecting write request %p",
2537                                       req);
2538                         blk_start_request(req);
2539                         __blk_end_request_all(req, -EIO);
2540                         continue;
2541                 }
2542                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2543                     (basedev->features & DASD_FEATURE_FAILFAST ||
2544                      blk_noretry_request(req))) {
2545                         DBF_DEV_EVENT(DBF_ERR, basedev,
2546                                       "Rejecting failfast request %p",
2547                                       req);
2548                         blk_start_request(req);
2549                         __blk_end_request_all(req, -ETIMEDOUT);
2550                         continue;
2551                 }
2552                 cqr = basedev->discipline->build_cp(basedev, block, req);
2553                 if (IS_ERR(cqr)) {
2554                         if (PTR_ERR(cqr) == -EBUSY)
2555                                 break;  /* normal end condition */
2556                         if (PTR_ERR(cqr) == -ENOMEM)
2557                                 break;  /* terminate request queue loop */
2558                         if (PTR_ERR(cqr) == -EAGAIN) {
2559                                 /*
2560                                  * The current request cannot be build right
2561                                  * now, we have to try later. If this request
2562                                  * is the head-of-queue we stop the device
2563                                  * for 1/2 second.
2564                                  */
2565                                 if (!list_empty(&block->ccw_queue))
2566                                         break;
2567                                 spin_lock_irqsave(
2568                                         get_ccwdev_lock(basedev->cdev), flags);
2569                                 dasd_device_set_stop_bits(basedev,
2570                                                           DASD_STOPPED_PENDING);
2571                                 spin_unlock_irqrestore(
2572                                         get_ccwdev_lock(basedev->cdev), flags);
2573                                 dasd_block_set_timer(block, HZ/2);
2574                                 break;
2575                         }
2576                         DBF_DEV_EVENT(DBF_ERR, basedev,
2577                                       "CCW creation failed (rc=%ld) "
2578                                       "on request %p",
2579                                       PTR_ERR(cqr), req);
2580                         blk_start_request(req);
2581                         __blk_end_request_all(req, -EIO);
2582                         continue;
2583                 }
2584                 /*
2585                  *  Note: callback is set to dasd_return_cqr_cb in
2586                  * __dasd_block_start_head to cover erp requests as well
2587                  */
2588                 cqr->callback_data = (void *) req;
2589                 cqr->status = DASD_CQR_FILLED;
2590                 req->completion_data = cqr;
2591                 blk_start_request(req);
2592                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2593                 INIT_LIST_HEAD(&cqr->devlist);
2594                 dasd_profile_start(block, cqr, req);
2595         }
2596 }
2597
2598 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2599 {
2600         struct request *req;
2601         int status;
2602         int error = 0;
2603
2604         req = (struct request *) cqr->callback_data;
2605         dasd_profile_end(cqr->block, cqr, req);
2606         status = cqr->block->base->discipline->free_cp(cqr, req);
2607         if (status < 0)
2608                 error = status;
2609         else if (status == 0) {
2610                 if (cqr->intrc == -EPERM)
2611                         error = -EBADE;
2612                 else if (cqr->intrc == -ENOLINK ||
2613                          cqr->intrc == -ETIMEDOUT)
2614                         error = cqr->intrc;
2615                 else
2616                         error = -EIO;
2617         }
2618         __blk_end_request_all(req, error);
2619 }
2620
2621 /*
2622  * Process ccw request queue.
2623  */
2624 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2625                                            struct list_head *final_queue)
2626 {
2627         struct list_head *l, *n;
2628         struct dasd_ccw_req *cqr;
2629         dasd_erp_fn_t erp_fn;
2630         unsigned long flags;
2631         struct dasd_device *base = block->base;
2632
2633 restart:
2634         /* Process request with final status. */
2635         list_for_each_safe(l, n, &block->ccw_queue) {
2636                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2637                 if (cqr->status != DASD_CQR_DONE &&
2638                     cqr->status != DASD_CQR_FAILED &&
2639                     cqr->status != DASD_CQR_NEED_ERP &&
2640                     cqr->status != DASD_CQR_TERMINATED)
2641                         continue;
2642
2643                 if (cqr->status == DASD_CQR_TERMINATED) {
2644                         base->discipline->handle_terminated_request(cqr);
2645                         goto restart;
2646                 }
2647
2648                 /*  Process requests that may be recovered */
2649                 if (cqr->status == DASD_CQR_NEED_ERP) {
2650                         erp_fn = base->discipline->erp_action(cqr);
2651                         if (IS_ERR(erp_fn(cqr)))
2652                                 continue;
2653                         goto restart;
2654                 }
2655
2656                 /* log sense for fatal error */
2657                 if (cqr->status == DASD_CQR_FAILED) {
2658                         dasd_log_sense(cqr, &cqr->irb);
2659                 }
2660
2661                 /* First of all call extended error reporting. */
2662                 if (dasd_eer_enabled(base) &&
2663                     cqr->status == DASD_CQR_FAILED) {
2664                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2665
2666                         /* restart request  */
2667                         cqr->status = DASD_CQR_FILLED;
2668                         cqr->retries = 255;
2669                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2670                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2671                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2672                                                flags);
2673                         goto restart;
2674                 }
2675
2676                 /* Process finished ERP request. */
2677                 if (cqr->refers) {
2678                         __dasd_process_erp(base, cqr);
2679                         goto restart;
2680                 }
2681
2682                 /* Rechain finished requests to final queue */
2683                 cqr->endclk = get_tod_clock();
2684                 list_move_tail(&cqr->blocklist, final_queue);
2685         }
2686 }
2687
2688 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2689 {
2690         dasd_schedule_block_bh(cqr->block);
2691 }
2692
2693 static void __dasd_block_start_head(struct dasd_block *block)
2694 {
2695         struct dasd_ccw_req *cqr;
2696
2697         if (list_empty(&block->ccw_queue))
2698                 return;
2699         /* We allways begin with the first requests on the queue, as some
2700          * of previously started requests have to be enqueued on a
2701          * dasd_device again for error recovery.
2702          */
2703         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2704                 if (cqr->status != DASD_CQR_FILLED)
2705                         continue;
2706                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2707                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2708                         cqr->status = DASD_CQR_FAILED;
2709                         cqr->intrc = -EPERM;
2710                         dasd_schedule_block_bh(block);
2711                         continue;
2712                 }
2713                 /* Non-temporary stop condition will trigger fail fast */
2714                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2715                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2716                     (!dasd_eer_enabled(block->base))) {
2717                         cqr->status = DASD_CQR_FAILED;
2718                         cqr->intrc = -ENOLINK;
2719                         dasd_schedule_block_bh(block);
2720                         continue;
2721                 }
2722                 /* Don't try to start requests if device is stopped */
2723                 if (block->base->stopped)
2724                         return;
2725
2726                 /* just a fail safe check, should not happen */
2727                 if (!cqr->startdev)
2728                         cqr->startdev = block->base;
2729
2730                 /* make sure that the requests we submit find their way back */
2731                 cqr->callback = dasd_return_cqr_cb;
2732
2733                 dasd_add_request_tail(cqr);
2734         }
2735 }
2736
2737 /*
2738  * Central dasd_block layer routine. Takes requests from the generic
2739  * block layer request queue, creates ccw requests, enqueues them on
2740  * a dasd_device and processes ccw requests that have been returned.
2741  */
2742 static void dasd_block_tasklet(struct dasd_block *block)
2743 {
2744         struct list_head final_queue;
2745         struct list_head *l, *n;
2746         struct dasd_ccw_req *cqr;
2747
2748         atomic_set(&block->tasklet_scheduled, 0);
2749         INIT_LIST_HEAD(&final_queue);
2750         spin_lock(&block->queue_lock);
2751         /* Finish off requests on ccw queue */
2752         __dasd_process_block_ccw_queue(block, &final_queue);
2753         spin_unlock(&block->queue_lock);
2754         /* Now call the callback function of requests with final status */
2755         spin_lock_irq(&block->request_queue_lock);
2756         list_for_each_safe(l, n, &final_queue) {
2757                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2758                 list_del_init(&cqr->blocklist);
2759                 __dasd_cleanup_cqr(cqr);
2760         }
2761         spin_lock(&block->queue_lock);
2762         /* Get new request from the block device request queue */
2763         __dasd_process_request_queue(block);
2764         /* Now check if the head of the ccw queue needs to be started. */
2765         __dasd_block_start_head(block);
2766         spin_unlock(&block->queue_lock);
2767         spin_unlock_irq(&block->request_queue_lock);
2768         if (waitqueue_active(&shutdown_waitq))
2769                 wake_up(&shutdown_waitq);
2770         dasd_put_device(block->base);
2771 }
2772
2773 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2774 {
2775         wake_up(&dasd_flush_wq);
2776 }
2777
2778 /*
2779  * Requeue a request back to the block request queue
2780  * only works for block requests
2781  */
2782 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2783 {
2784         struct dasd_block *block = cqr->block;
2785         struct request *req;
2786         unsigned long flags;
2787
2788         if (!block)
2789                 return -EINVAL;
2790         spin_lock_irqsave(&block->queue_lock, flags);
2791         req = (struct request *) cqr->callback_data;
2792         blk_requeue_request(block->request_queue, req);
2793         spin_unlock_irqrestore(&block->queue_lock, flags);
2794
2795         return 0;
2796 }
2797
2798 /*
2799  * Go through all request on the dasd_block request queue, cancel them
2800  * on the respective dasd_device, and return them to the generic
2801  * block layer.
2802  */
2803 static int dasd_flush_block_queue(struct dasd_block *block)
2804 {
2805         struct dasd_ccw_req *cqr, *n;
2806         int rc, i;
2807         struct list_head flush_queue;
2808
2809         INIT_LIST_HEAD(&flush_queue);
2810         spin_lock_bh(&block->queue_lock);
2811         rc = 0;
2812 restart:
2813         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2814                 /* if this request currently owned by a dasd_device cancel it */
2815                 if (cqr->status >= DASD_CQR_QUEUED)
2816                         rc = dasd_cancel_req(cqr);
2817                 if (rc < 0)
2818                         break;
2819                 /* Rechain request (including erp chain) so it won't be
2820                  * touched by the dasd_block_tasklet anymore.
2821                  * Replace the callback so we notice when the request
2822                  * is returned from the dasd_device layer.
2823                  */
2824                 cqr->callback = _dasd_wake_block_flush_cb;
2825                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2826                         list_move_tail(&cqr->blocklist, &flush_queue);
2827                 if (i > 1)
2828                         /* moved more than one request - need to restart */
2829                         goto restart;
2830         }
2831         spin_unlock_bh(&block->queue_lock);
2832         /* Now call the callback function of flushed requests */
2833 restart_cb:
2834         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2835                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2836                 /* Process finished ERP request. */
2837                 if (cqr->refers) {
2838                         spin_lock_bh(&block->queue_lock);
2839                         __dasd_process_erp(block->base, cqr);
2840                         spin_unlock_bh(&block->queue_lock);
2841                         /* restart list_for_xx loop since dasd_process_erp
2842                          * might remove multiple elements */
2843                         goto restart_cb;
2844                 }
2845                 /* call the callback function */
2846                 spin_lock_irq(&block->request_queue_lock);
2847                 cqr->endclk = get_tod_clock();
2848                 list_del_init(&cqr->blocklist);
2849                 __dasd_cleanup_cqr(cqr);
2850                 spin_unlock_irq(&block->request_queue_lock);
2851         }
2852         return rc;
2853 }
2854
2855 /*
2856  * Schedules a call to dasd_tasklet over the device tasklet.
2857  */
2858 void dasd_schedule_block_bh(struct dasd_block *block)
2859 {
2860         /* Protect against rescheduling. */
2861         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2862                 return;
2863         /* life cycle of block is bound to it's base device */
2864         dasd_get_device(block->base);
2865         tasklet_hi_schedule(&block->tasklet);
2866 }
2867
2868
2869 /*
2870  * SECTION: external block device operations
2871  * (request queue handling, open, release, etc.)
2872  */
2873
2874 /*
2875  * Dasd request queue function. Called from ll_rw_blk.c
2876  */
2877 static void do_dasd_request(struct request_queue *queue)
2878 {
2879         struct dasd_block *block;
2880
2881         block = queue->queuedata;
2882         spin_lock(&block->queue_lock);
2883         /* Get new request from the block device request queue */
2884         __dasd_process_request_queue(block);
2885         /* Now check if the head of the ccw queue needs to be started. */
2886         __dasd_block_start_head(block);
2887         spin_unlock(&block->queue_lock);
2888 }
2889
2890 /*
2891  * Block timeout callback, called from the block layer
2892  *
2893  * request_queue lock is held on entry.
2894  *
2895  * Return values:
2896  * BLK_EH_RESET_TIMER if the request should be left running
2897  * BLK_EH_NOT_HANDLED if the request is handled or terminated
2898  *                    by the driver.
2899  */
2900 enum blk_eh_timer_return dasd_times_out(struct request *req)
2901 {
2902         struct dasd_ccw_req *cqr = req->completion_data;
2903         struct dasd_block *block = req->q->queuedata;
2904         struct dasd_device *device;
2905         int rc = 0;
2906
2907         if (!cqr)
2908                 return BLK_EH_NOT_HANDLED;
2909
2910         device = cqr->startdev ? cqr->startdev : block->base;
2911         if (!device->blk_timeout)
2912                 return BLK_EH_RESET_TIMER;
2913         DBF_DEV_EVENT(DBF_WARNING, device,
2914                       " dasd_times_out cqr %p status %x",
2915                       cqr, cqr->status);
2916
2917         spin_lock(&block->queue_lock);
2918         spin_lock(get_ccwdev_lock(device->cdev));
2919         cqr->retries = -1;
2920         cqr->intrc = -ETIMEDOUT;
2921         if (cqr->status >= DASD_CQR_QUEUED) {
2922                 spin_unlock(get_ccwdev_lock(device->cdev));
2923                 rc = dasd_cancel_req(cqr);
2924         } else if (cqr->status == DASD_CQR_FILLED ||
2925                    cqr->status == DASD_CQR_NEED_ERP) {
2926                 cqr->status = DASD_CQR_TERMINATED;
2927                 spin_unlock(get_ccwdev_lock(device->cdev));
2928         } else if (cqr->status == DASD_CQR_IN_ERP) {
2929                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
2930
2931                 list_for_each_entry_safe(searchcqr, nextcqr,
2932                                          &block->ccw_queue, blocklist) {
2933                         tmpcqr = searchcqr;
2934                         while (tmpcqr->refers)
2935                                 tmpcqr = tmpcqr->refers;
2936                         if (tmpcqr != cqr)
2937                                 continue;
2938                         /* searchcqr is an ERP request for cqr */
2939                         searchcqr->retries = -1;
2940                         searchcqr->intrc = -ETIMEDOUT;
2941                         if (searchcqr->status >= DASD_CQR_QUEUED) {
2942                                 spin_unlock(get_ccwdev_lock(device->cdev));
2943                                 rc = dasd_cancel_req(searchcqr);
2944                                 spin_lock(get_ccwdev_lock(device->cdev));
2945                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
2946                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
2947                                 searchcqr->status = DASD_CQR_TERMINATED;
2948                                 rc = 0;
2949                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
2950                                 /*
2951                                  * Shouldn't happen; most recent ERP
2952                                  * request is at the front of queue
2953                                  */
2954                                 continue;
2955                         }
2956                         break;
2957                 }
2958                 spin_unlock(get_ccwdev_lock(device->cdev));
2959         }
2960         dasd_schedule_block_bh(block);
2961         spin_unlock(&block->queue_lock);
2962
2963         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
2964 }
2965
2966 /*
2967  * Allocate and initialize request queue and default I/O scheduler.
2968  */
2969 static int dasd_alloc_queue(struct dasd_block *block)
2970 {
2971         int rc;
2972
2973         block->request_queue = blk_init_queue(do_dasd_request,
2974                                                &block->request_queue_lock);
2975         if (block->request_queue == NULL)
2976                 return -ENOMEM;
2977
2978         block->request_queue->queuedata = block;
2979
2980         elevator_exit(block->request_queue->elevator);
2981         block->request_queue->elevator = NULL;
2982         mutex_lock(&block->request_queue->sysfs_lock);
2983         rc = elevator_init(block->request_queue, "deadline");
2984         if (rc)
2985                 blk_cleanup_queue(block->request_queue);
2986         mutex_unlock(&block->request_queue->sysfs_lock);
2987         return rc;
2988 }
2989
2990 /*
2991  * Allocate and initialize request queue.
2992  */
2993 static void dasd_setup_queue(struct dasd_block *block)
2994 {
2995         int max;
2996
2997         if (block->base->features & DASD_FEATURE_USERAW) {
2998                 /*
2999                  * the max_blocks value for raw_track access is 256
3000                  * it is higher than the native ECKD value because we
3001                  * only need one ccw per track
3002                  * so the max_hw_sectors are
3003                  * 2048 x 512B = 1024kB = 16 tracks
3004                  */
3005                 max = 2048;
3006         } else {
3007                 max = block->base->discipline->max_blocks << block->s2b_shift;
3008         }
3009         blk_queue_logical_block_size(block->request_queue,
3010                                      block->bp_block);
3011         blk_queue_max_hw_sectors(block->request_queue, max);
3012         blk_queue_max_segments(block->request_queue, -1L);
3013         /* with page sized segments we can translate each segement into
3014          * one idaw/tidaw
3015          */
3016         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3017         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3018 }
3019
3020 /*
3021  * Deactivate and free request queue.
3022  */
3023 static void dasd_free_queue(struct dasd_block *block)
3024 {
3025         if (block->request_queue) {
3026                 blk_cleanup_queue(block->request_queue);
3027                 block->request_queue = NULL;
3028         }
3029 }
3030
3031 /*
3032  * Flush request on the request queue.
3033  */
3034 static void dasd_flush_request_queue(struct dasd_block *block)
3035 {
3036         struct request *req;
3037
3038         if (!block->request_queue)
3039                 return;
3040
3041         spin_lock_irq(&block->request_queue_lock);
3042         while ((req = blk_fetch_request(block->request_queue)))
3043                 __blk_end_request_all(req, -EIO);
3044         spin_unlock_irq(&block->request_queue_lock);
3045 }
3046
3047 static int dasd_open(struct block_device *bdev, fmode_t mode)
3048 {
3049         struct dasd_device *base;
3050         int rc;
3051
3052         base = dasd_device_from_gendisk(bdev->bd_disk);
3053         if (!base)
3054                 return -ENODEV;
3055
3056         atomic_inc(&base->block->open_count);
3057         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3058                 rc = -ENODEV;
3059                 goto unlock;
3060         }
3061
3062         if (!try_module_get(base->discipline->owner)) {
3063                 rc = -EINVAL;
3064                 goto unlock;
3065         }
3066
3067         if (dasd_probeonly) {
3068                 dev_info(&base->cdev->dev,
3069                          "Accessing the DASD failed because it is in "
3070                          "probeonly mode\n");
3071                 rc = -EPERM;
3072                 goto out;
3073         }
3074
3075         if (base->state <= DASD_STATE_BASIC) {
3076                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3077                               " Cannot open unrecognized device");
3078                 rc = -ENODEV;
3079                 goto out;
3080         }
3081
3082         if ((mode & FMODE_WRITE) &&
3083             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3084              (base->features & DASD_FEATURE_READONLY))) {
3085                 rc = -EROFS;
3086                 goto out;
3087         }
3088
3089         dasd_put_device(base);
3090         return 0;
3091
3092 out:
3093         module_put(base->discipline->owner);
3094 unlock:
3095         atomic_dec(&base->block->open_count);
3096         dasd_put_device(base);
3097         return rc;
3098 }
3099
3100 static void dasd_release(struct gendisk *disk, fmode_t mode)
3101 {
3102         struct dasd_device *base = dasd_device_from_gendisk(disk);
3103         if (base) {
3104                 atomic_dec(&base->block->open_count);
3105                 module_put(base->discipline->owner);
3106                 dasd_put_device(base);
3107         }
3108 }
3109
3110 /*
3111  * Return disk geometry.
3112  */
3113 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3114 {
3115         struct dasd_device *base;
3116
3117         base = dasd_device_from_gendisk(bdev->bd_disk);
3118         if (!base)
3119                 return -ENODEV;
3120
3121         if (!base->discipline ||
3122             !base->discipline->fill_geometry) {
3123                 dasd_put_device(base);
3124                 return -EINVAL;
3125         }
3126         base->discipline->fill_geometry(base->block, geo);
3127         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3128         dasd_put_device(base);
3129         return 0;
3130 }
3131
3132 const struct block_device_operations
3133 dasd_device_operations = {
3134         .owner          = THIS_MODULE,
3135         .open           = dasd_open,
3136         .release        = dasd_release,
3137         .ioctl          = dasd_ioctl,
3138         .compat_ioctl   = dasd_ioctl,
3139         .getgeo         = dasd_getgeo,
3140 };
3141
3142 /*******************************************************************************
3143  * end of block device operations
3144  */
3145
3146 static void
3147 dasd_exit(void)
3148 {
3149 #ifdef CONFIG_PROC_FS
3150         dasd_proc_exit();
3151 #endif
3152         dasd_eer_exit();
3153         if (dasd_page_cache != NULL) {
3154                 kmem_cache_destroy(dasd_page_cache);
3155                 dasd_page_cache = NULL;
3156         }
3157         dasd_gendisk_exit();
3158         dasd_devmap_exit();
3159         if (dasd_debug_area != NULL) {
3160                 debug_unregister(dasd_debug_area);
3161                 dasd_debug_area = NULL;
3162         }
3163         dasd_statistics_removeroot();
3164 }
3165
3166 /*
3167  * SECTION: common functions for ccw_driver use
3168  */
3169
3170 /*
3171  * Is the device read-only?
3172  * Note that this function does not report the setting of the
3173  * readonly device attribute, but how it is configured in z/VM.
3174  */
3175 int dasd_device_is_ro(struct dasd_device *device)
3176 {
3177         struct ccw_dev_id dev_id;
3178         struct diag210 diag_data;
3179         int rc;
3180
3181         if (!MACHINE_IS_VM)
3182                 return 0;
3183         ccw_device_get_id(device->cdev, &dev_id);
3184         memset(&diag_data, 0, sizeof(diag_data));
3185         diag_data.vrdcdvno = dev_id.devno;
3186         diag_data.vrdclen = sizeof(diag_data);
3187         rc = diag210(&diag_data);
3188         if (rc == 0 || rc == 2) {
3189                 return diag_data.vrdcvfla & 0x80;
3190         } else {
3191                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3192                           dev_id.devno, rc);
3193                 return 0;
3194         }
3195 }
3196 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3197
3198 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3199 {
3200         struct ccw_device *cdev = data;
3201         int ret;
3202
3203         ret = ccw_device_set_online(cdev);
3204         if (ret)
3205                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
3206                            dev_name(&cdev->dev), ret);
3207 }
3208
3209 /*
3210  * Initial attempt at a probe function. this can be simplified once
3211  * the other detection code is gone.
3212  */
3213 int dasd_generic_probe(struct ccw_device *cdev,
3214                        struct dasd_discipline *discipline)
3215 {
3216         int ret;
3217
3218         ret = dasd_add_sysfs_files(cdev);
3219         if (ret) {
3220                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3221                                 "dasd_generic_probe: could not add "
3222                                 "sysfs entries");
3223                 return ret;
3224         }
3225         cdev->handler = &dasd_int_handler;
3226
3227         /*
3228          * Automatically online either all dasd devices (dasd_autodetect)
3229          * or all devices specified with dasd= parameters during
3230          * initial probe.
3231          */
3232         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3233             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3234                 async_schedule(dasd_generic_auto_online, cdev);
3235         return 0;
3236 }
3237
3238 /*
3239  * This will one day be called from a global not_oper handler.
3240  * It is also used by driver_unregister during module unload.
3241  */
3242 void dasd_generic_remove(struct ccw_device *cdev)
3243 {
3244         struct dasd_device *device;
3245         struct dasd_block *block;
3246
3247         cdev->handler = NULL;
3248
3249         device = dasd_device_from_cdev(cdev);
3250         if (IS_ERR(device)) {
3251                 dasd_remove_sysfs_files(cdev);
3252                 return;
3253         }
3254         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3255             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3256                 /* Already doing offline processing */
3257                 dasd_put_device(device);
3258                 dasd_remove_sysfs_files(cdev);
3259                 return;
3260         }
3261         /*
3262          * This device is removed unconditionally. Set offline
3263          * flag to prevent dasd_open from opening it while it is
3264          * no quite down yet.
3265          */
3266         dasd_set_target_state(device, DASD_STATE_NEW);
3267         /* dasd_delete_device destroys the device reference. */
3268         block = device->block;
3269         dasd_delete_device(device);
3270         /*
3271          * life cycle of block is bound to device, so delete it after
3272          * device was safely removed
3273          */
3274         if (block)
3275                 dasd_free_block(block);
3276
3277         dasd_remove_sysfs_files(cdev);
3278 }
3279
3280 /*
3281  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3282  * the device is detected for the first time and is supposed to be used
3283  * or the user has started activation through sysfs.
3284  */
3285 int dasd_generic_set_online(struct ccw_device *cdev,
3286                             struct dasd_discipline *base_discipline)
3287 {
3288         struct dasd_discipline *discipline;
3289         struct dasd_device *device;
3290         int rc;
3291
3292         /* first online clears initial online feature flag */
3293         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3294         device = dasd_create_device(cdev);
3295         if (IS_ERR(device))
3296                 return PTR_ERR(device);
3297
3298         discipline = base_discipline;
3299         if (device->features & DASD_FEATURE_USEDIAG) {
3300                 if (!dasd_diag_discipline_pointer) {
3301                         pr_warning("%s Setting the DASD online failed because "
3302                                    "of missing DIAG discipline\n",
3303                                    dev_name(&cdev->dev));
3304                         dasd_delete_device(device);
3305                         return -ENODEV;
3306                 }
3307                 discipline = dasd_diag_discipline_pointer;
3308         }
3309         if (!try_module_get(base_discipline->owner)) {
3310                 dasd_delete_device(device);
3311                 return -EINVAL;
3312         }
3313         if (!try_module_get(discipline->owner)) {
3314                 module_put(base_discipline->owner);
3315                 dasd_delete_device(device);
3316                 return -EINVAL;
3317         }
3318         device->base_discipline = base_discipline;
3319         device->discipline = discipline;
3320
3321         /* check_device will allocate block device if necessary */
3322         rc = discipline->check_device(device);
3323         if (rc) {
3324                 pr_warning("%s Setting the DASD online with discipline %s "
3325                            "failed with rc=%i\n",
3326                            dev_name(&cdev->dev), discipline->name, rc);
3327                 module_put(discipline->owner);
3328                 module_put(base_discipline->owner);
3329                 dasd_delete_device(device);
3330                 return rc;
3331         }
3332
3333         dasd_set_target_state(device, DASD_STATE_ONLINE);
3334         if (device->state <= DASD_STATE_KNOWN) {
3335                 pr_warning("%s Setting the DASD online failed because of a "
3336                            "missing discipline\n", dev_name(&cdev->dev));
3337                 rc = -ENODEV;
3338                 dasd_set_target_state(device, DASD_STATE_NEW);
3339                 if (device->block)
3340                         dasd_free_block(device->block);
3341                 dasd_delete_device(device);
3342         } else
3343                 pr_debug("dasd_generic device %s found\n",
3344                                 dev_name(&cdev->dev));
3345
3346         wait_event(dasd_init_waitq, _wait_for_device(device));
3347
3348         dasd_put_device(device);
3349         return rc;
3350 }
3351
3352 int dasd_generic_set_offline(struct ccw_device *cdev)
3353 {
3354         struct dasd_device *device;
3355         struct dasd_block *block;
3356         int max_count, open_count, rc;
3357
3358         rc = 0;
3359         device = dasd_device_from_cdev(cdev);
3360         if (IS_ERR(device))
3361                 return PTR_ERR(device);
3362
3363         /*
3364          * We must make sure that this device is currently not in use.
3365          * The open_count is increased for every opener, that includes
3366          * the blkdev_get in dasd_scan_partitions. We are only interested
3367          * in the other openers.
3368          */
3369         if (device->block) {
3370                 max_count = device->block->bdev ? 0 : -1;
3371                 open_count = atomic_read(&device->block->open_count);
3372                 if (open_count > max_count) {
3373                         if (open_count > 0)
3374                                 pr_warning("%s: The DASD cannot be set offline "
3375                                            "with open count %i\n",
3376                                            dev_name(&cdev->dev), open_count);
3377                         else
3378                                 pr_warning("%s: The DASD cannot be set offline "
3379                                            "while it is in use\n",
3380                                            dev_name(&cdev->dev));
3381                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3382                         dasd_put_device(device);
3383                         return -EBUSY;
3384                 }
3385         }
3386
3387         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3388                 /*
3389                  * safe offline allready running
3390                  * could only be called by normal offline so safe_offline flag
3391                  * needs to be removed to run normal offline and kill all I/O
3392                  */
3393                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3394                         /* Already doing normal offline processing */
3395                         dasd_put_device(device);
3396                         return -EBUSY;
3397                 } else
3398                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3399
3400         } else
3401                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3402                         /* Already doing offline processing */
3403                         dasd_put_device(device);
3404                         return -EBUSY;
3405                 }
3406
3407         /*
3408          * if safe_offline called set safe_offline_running flag and
3409          * clear safe_offline so that a call to normal offline
3410          * can overrun safe_offline processing
3411          */
3412         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3413             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3414                 /*
3415                  * If we want to set the device safe offline all IO operations
3416                  * should be finished before continuing the offline process
3417                  * so sync bdev first and then wait for our queues to become
3418                  * empty
3419                  */
3420                 /* sync blockdev and partitions */
3421                 rc = fsync_bdev(device->block->bdev);
3422                 if (rc != 0)
3423                         goto interrupted;
3424
3425                 /* schedule device tasklet and wait for completion */
3426                 dasd_schedule_device_bh(device);
3427                 rc = wait_event_interruptible(shutdown_waitq,
3428                                               _wait_for_empty_queues(device));
3429                 if (rc != 0)
3430                         goto interrupted;
3431         }
3432
3433         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3434         dasd_set_target_state(device, DASD_STATE_NEW);
3435         /* dasd_delete_device destroys the device reference. */
3436         block = device->block;
3437         dasd_delete_device(device);
3438         /*
3439          * life cycle of block is bound to device, so delete it after
3440          * device was safely removed
3441          */
3442         if (block)
3443                 dasd_free_block(block);
3444         return 0;
3445
3446 interrupted:
3447         /* interrupted by signal */
3448         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3449         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3450         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3451         dasd_put_device(device);
3452         return rc;
3453 }
3454
3455 int dasd_generic_last_path_gone(struct dasd_device *device)
3456 {
3457         struct dasd_ccw_req *cqr;
3458
3459         dev_warn(&device->cdev->dev, "No operational channel path is left "
3460                  "for the device\n");
3461         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3462         /* First of all call extended error reporting. */
3463         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3464
3465         if (device->state < DASD_STATE_BASIC)
3466                 return 0;
3467         /* Device is active. We want to keep it. */
3468         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3469                 if ((cqr->status == DASD_CQR_IN_IO) ||
3470                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3471                         cqr->status = DASD_CQR_QUEUED;
3472                         cqr->retries++;
3473                 }
3474         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3475         dasd_device_clear_timer(device);
3476         dasd_schedule_device_bh(device);
3477         return 1;
3478 }
3479 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3480
3481 int dasd_generic_path_operational(struct dasd_device *device)
3482 {
3483         dev_info(&device->cdev->dev, "A channel path to the device has become "
3484                  "operational\n");
3485         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3486         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3487         if (device->stopped & DASD_UNRESUMED_PM) {
3488                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3489                 dasd_restore_device(device);
3490                 return 1;
3491         }
3492         dasd_schedule_device_bh(device);
3493         if (device->block)
3494                 dasd_schedule_block_bh(device->block);
3495         return 1;
3496 }
3497 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3498
3499 int dasd_generic_notify(struct ccw_device *cdev, int event)
3500 {
3501         struct dasd_device *device;
3502         int ret;
3503
3504         device = dasd_device_from_cdev_locked(cdev);
3505         if (IS_ERR(device))
3506                 return 0;
3507         ret = 0;
3508         switch (event) {
3509         case CIO_GONE:
3510         case CIO_BOXED:
3511         case CIO_NO_PATH:
3512                 device->path_data.opm = 0;
3513                 device->path_data.ppm = 0;
3514                 device->path_data.npm = 0;
3515                 ret = dasd_generic_last_path_gone(device);
3516                 break;
3517         case CIO_OPER:
3518                 ret = 1;
3519                 if (device->path_data.opm)
3520                         ret = dasd_generic_path_operational(device);
3521                 break;
3522         }
3523         dasd_put_device(device);
3524         return ret;
3525 }
3526
3527 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3528 {
3529         int chp;
3530         __u8 oldopm, eventlpm;
3531         struct dasd_device *device;
3532
3533         device = dasd_device_from_cdev_locked(cdev);
3534         if (IS_ERR(device))
3535                 return;
3536         for (chp = 0; chp < 8; chp++) {
3537                 eventlpm = 0x80 >> chp;
3538                 if (path_event[chp] & PE_PATH_GONE) {
3539                         oldopm = device->path_data.opm;
3540                         device->path_data.opm &= ~eventlpm;
3541                         device->path_data.ppm &= ~eventlpm;
3542                         device->path_data.npm &= ~eventlpm;
3543                         if (oldopm && !device->path_data.opm) {
3544                                 dev_warn(&device->cdev->dev,
3545                                          "No verified channel paths remain "
3546                                          "for the device\n");
3547                                 DBF_DEV_EVENT(DBF_WARNING, device,
3548                                               "%s", "last verified path gone");
3549                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3550                                 dasd_device_set_stop_bits(device,
3551                                                           DASD_STOPPED_DC_WAIT);
3552                         }
3553                 }
3554                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3555                         device->path_data.opm &= ~eventlpm;
3556                         device->path_data.ppm &= ~eventlpm;
3557                         device->path_data.npm &= ~eventlpm;
3558                         device->path_data.tbvpm |= eventlpm;
3559                         dasd_schedule_device_bh(device);
3560                 }
3561                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3562                         if (!(device->path_data.opm & eventlpm) &&
3563                             !(device->path_data.tbvpm & eventlpm)) {
3564                                 /*
3565                                  * we can not establish a pathgroup on an
3566                                  * unavailable path, so trigger a path
3567                                  * verification first
3568                                  */
3569                                 device->path_data.tbvpm |= eventlpm;
3570                                 dasd_schedule_device_bh(device);
3571                         }
3572                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3573                                       "Pathgroup re-established\n");
3574                         if (device->discipline->kick_validate)
3575                                 device->discipline->kick_validate(device);
3576                 }
3577         }
3578         dasd_put_device(device);
3579 }
3580 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3581
3582 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3583 {
3584         if (!device->path_data.opm && lpm) {
3585                 device->path_data.opm = lpm;
3586                 dasd_generic_path_operational(device);
3587         } else
3588                 device->path_data.opm |= lpm;
3589         return 0;
3590 }
3591 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3592
3593
3594 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3595 {
3596         struct dasd_device *device = dasd_device_from_cdev(cdev);
3597         struct list_head freeze_queue;
3598         struct dasd_ccw_req *cqr, *n;
3599         struct dasd_ccw_req *refers;
3600         int rc;
3601
3602         if (IS_ERR(device))
3603                 return PTR_ERR(device);
3604
3605         /* mark device as suspended */
3606         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3607
3608         if (device->discipline->freeze)
3609                 rc = device->discipline->freeze(device);
3610
3611         /* disallow new I/O  */
3612         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3613
3614         /* clear active requests and requeue them to block layer if possible */
3615         INIT_LIST_HEAD(&freeze_queue);
3616         spin_lock_irq(get_ccwdev_lock(cdev));
3617         rc = 0;
3618         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3619                 /* Check status and move request to flush_queue */
3620                 if (cqr->status == DASD_CQR_IN_IO) {
3621                         rc = device->discipline->term_IO(cqr);
3622                         if (rc) {
3623                                 /* unable to terminate requeust */
3624                                 dev_err(&device->cdev->dev,
3625                                         "Unable to terminate request %p "
3626                                         "on suspend\n", cqr);
3627                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3628                                 dasd_put_device(device);
3629                                 return rc;
3630                         }
3631                 }
3632                 list_move_tail(&cqr->devlist, &freeze_queue);
3633         }
3634         spin_unlock_irq(get_ccwdev_lock(cdev));
3635
3636         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3637                 wait_event(dasd_flush_wq,
3638                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3639                 if (cqr->status == DASD_CQR_CLEARED)
3640                         cqr->status = DASD_CQR_QUEUED;
3641
3642                 /* requeue requests to blocklayer will only work for
3643                    block device requests */
3644                 if (_dasd_requeue_request(cqr))
3645                         continue;
3646
3647                 /* remove requests from device and block queue */
3648                 list_del_init(&cqr->devlist);
3649                 while (cqr->refers != NULL) {
3650                         refers = cqr->refers;
3651                         /* remove the request from the block queue */
3652                         list_del(&cqr->blocklist);
3653                         /* free the finished erp request */
3654                         dasd_free_erp_request(cqr, cqr->memdev);
3655                         cqr = refers;
3656                 }
3657                 if (cqr->block)
3658                         list_del_init(&cqr->blocklist);
3659                 cqr->block->base->discipline->free_cp(
3660                         cqr, (struct request *) cqr->callback_data);
3661         }
3662
3663         /*
3664          * if requests remain then they are internal request
3665          * and go back to the device queue
3666          */
3667         if (!list_empty(&freeze_queue)) {
3668                 /* move freeze_queue to start of the ccw_queue */
3669                 spin_lock_irq(get_ccwdev_lock(cdev));
3670                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3671                 spin_unlock_irq(get_ccwdev_lock(cdev));
3672         }
3673         dasd_put_device(device);
3674         return rc;
3675 }
3676 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3677
3678 int dasd_generic_restore_device(struct ccw_device *cdev)
3679 {
3680         struct dasd_device *device = dasd_device_from_cdev(cdev);
3681         int rc = 0;
3682
3683         if (IS_ERR(device))
3684                 return PTR_ERR(device);
3685
3686         /* allow new IO again */
3687         dasd_device_remove_stop_bits(device,
3688                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3689
3690         dasd_schedule_device_bh(device);
3691
3692         /*
3693          * call discipline restore function
3694          * if device is stopped do nothing e.g. for disconnected devices
3695          */
3696         if (device->discipline->restore && !(device->stopped))
3697                 rc = device->discipline->restore(device);
3698         if (rc || device->stopped)
3699                 /*
3700                  * if the resume failed for the DASD we put it in
3701                  * an UNRESUMED stop state
3702                  */
3703                 device->stopped |= DASD_UNRESUMED_PM;
3704
3705         if (device->block)
3706                 dasd_schedule_block_bh(device->block);
3707
3708         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3709         dasd_put_device(device);
3710         return 0;
3711 }
3712 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3713
3714 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3715                                                    void *rdc_buffer,
3716                                                    int rdc_buffer_size,
3717                                                    int magic)
3718 {
3719         struct dasd_ccw_req *cqr;
3720         struct ccw1 *ccw;
3721         unsigned long *idaw;
3722
3723         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3724
3725         if (IS_ERR(cqr)) {
3726                 /* internal error 13 - Allocating the RDC request failed*/
3727                 dev_err(&device->cdev->dev,
3728                          "An error occurred in the DASD device driver, "
3729                          "reason=%s\n", "13");
3730                 return cqr;
3731         }
3732
3733         ccw = cqr->cpaddr;
3734         ccw->cmd_code = CCW_CMD_RDC;
3735         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3736                 idaw = (unsigned long *) (cqr->data);
3737                 ccw->cda = (__u32)(addr_t) idaw;
3738                 ccw->flags = CCW_FLAG_IDA;
3739                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3740         } else {
3741                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3742                 ccw->flags = 0;
3743         }
3744
3745         ccw->count = rdc_buffer_size;
3746         cqr->startdev = device;
3747         cqr->memdev = device;
3748         cqr->expires = 10*HZ;
3749         cqr->retries = 256;
3750         cqr->buildclk = get_tod_clock();
3751         cqr->status = DASD_CQR_FILLED;
3752         return cqr;
3753 }
3754
3755
3756 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3757                                 void *rdc_buffer, int rdc_buffer_size)
3758 {
3759         int ret;
3760         struct dasd_ccw_req *cqr;
3761
3762         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3763                                      magic);
3764         if (IS_ERR(cqr))
3765                 return PTR_ERR(cqr);
3766
3767         ret = dasd_sleep_on(cqr);
3768         dasd_sfree_request(cqr, cqr->memdev);
3769         return ret;
3770 }
3771 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3772
3773 /*
3774  *   In command mode and transport mode we need to look for sense
3775  *   data in different places. The sense data itself is allways
3776  *   an array of 32 bytes, so we can unify the sense data access
3777  *   for both modes.
3778  */
3779 char *dasd_get_sense(struct irb *irb)
3780 {
3781         struct tsb *tsb = NULL;
3782         char *sense = NULL;
3783
3784         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3785                 if (irb->scsw.tm.tcw)
3786                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3787                                           irb->scsw.tm.tcw);
3788                 if (tsb && tsb->length == 64 && tsb->flags)
3789                         switch (tsb->flags & 0x07) {
3790                         case 1: /* tsa_iostat */
3791                                 sense = tsb->tsa.iostat.sense;
3792                                 break;
3793                         case 2: /* tsa_ddpc */
3794                                 sense = tsb->tsa.ddpc.sense;
3795                                 break;
3796                         default:
3797                                 /* currently we don't use interrogate data */
3798                                 break;
3799                         }
3800         } else if (irb->esw.esw0.erw.cons) {
3801                 sense = irb->ecw;
3802         }
3803         return sense;
3804 }
3805 EXPORT_SYMBOL_GPL(dasd_get_sense);
3806
3807 void dasd_generic_shutdown(struct ccw_device *cdev)
3808 {
3809         struct dasd_device *device;
3810
3811         device = dasd_device_from_cdev(cdev);
3812         if (IS_ERR(device))
3813                 return;
3814
3815         if (device->block)
3816                 dasd_schedule_block_bh(device->block);
3817
3818         dasd_schedule_device_bh(device);
3819
3820         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3821 }
3822 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3823
3824 static int __init dasd_init(void)
3825 {
3826         int rc;
3827
3828         init_waitqueue_head(&dasd_init_waitq);
3829         init_waitqueue_head(&dasd_flush_wq);
3830         init_waitqueue_head(&generic_waitq);
3831         init_waitqueue_head(&shutdown_waitq);
3832
3833         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3834         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3835         if (dasd_debug_area == NULL) {
3836                 rc = -ENOMEM;
3837                 goto failed;
3838         }
3839         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3840         debug_set_level(dasd_debug_area, DBF_WARNING);
3841
3842         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3843
3844         dasd_diag_discipline_pointer = NULL;
3845
3846         dasd_statistics_createroot();
3847
3848         rc = dasd_devmap_init();
3849         if (rc)
3850                 goto failed;
3851         rc = dasd_gendisk_init();
3852         if (rc)
3853                 goto failed;
3854         rc = dasd_parse();
3855         if (rc)
3856                 goto failed;
3857         rc = dasd_eer_init();
3858         if (rc)
3859                 goto failed;
3860 #ifdef CONFIG_PROC_FS
3861         rc = dasd_proc_init();
3862         if (rc)
3863                 goto failed;
3864 #endif
3865
3866         return 0;
3867 failed:
3868         pr_info("The DASD device driver could not be initialized\n");
3869         dasd_exit();
3870         return rc;
3871 }
3872
3873 module_init(dasd_init);
3874 module_exit(dasd_exit);
3875
3876 EXPORT_SYMBOL(dasd_debug_area);
3877 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
3878
3879 EXPORT_SYMBOL(dasd_add_request_head);
3880 EXPORT_SYMBOL(dasd_add_request_tail);
3881 EXPORT_SYMBOL(dasd_cancel_req);
3882 EXPORT_SYMBOL(dasd_device_clear_timer);
3883 EXPORT_SYMBOL(dasd_block_clear_timer);
3884 EXPORT_SYMBOL(dasd_enable_device);
3885 EXPORT_SYMBOL(dasd_int_handler);
3886 EXPORT_SYMBOL(dasd_kfree_request);
3887 EXPORT_SYMBOL(dasd_kick_device);
3888 EXPORT_SYMBOL(dasd_kmalloc_request);
3889 EXPORT_SYMBOL(dasd_schedule_device_bh);
3890 EXPORT_SYMBOL(dasd_schedule_block_bh);
3891 EXPORT_SYMBOL(dasd_set_target_state);
3892 EXPORT_SYMBOL(dasd_device_set_timer);
3893 EXPORT_SYMBOL(dasd_block_set_timer);
3894 EXPORT_SYMBOL(dasd_sfree_request);
3895 EXPORT_SYMBOL(dasd_sleep_on);
3896 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
3897 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
3898 EXPORT_SYMBOL(dasd_smalloc_request);
3899 EXPORT_SYMBOL(dasd_start_IO);
3900 EXPORT_SYMBOL(dasd_term_IO);
3901
3902 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3903 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3904 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3905 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3906 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3907 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
3908 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
3909 EXPORT_SYMBOL_GPL(dasd_alloc_block);
3910 EXPORT_SYMBOL_GPL(dasd_free_block);