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 EXPORT_SYMBOL(dasd_debug_area);
  46 static struct dentry *dasd_debugfs_root_entry;
  47 struct dasd_discipline *dasd_diag_discipline_pointer;
  48 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  49 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  50
  51 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  52 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  53                    " Copyright IBM Corp. 2000");
  54 MODULE_SUPPORTED_DEVICE("dasd");
  55 MODULE_LICENSE("GPL");
  56
  57 /*
  58  * SECTION: prototypes for static functions of dasd.c
  59  */
  60 static int  dasd_alloc_queue(struct dasd_block *);
  61 static void dasd_setup_queue(struct dasd_block *);
  62 static void dasd_free_queue(struct dasd_block *);
  63 static void dasd_flush_request_queue(struct dasd_block *);
  64 static int dasd_flush_block_queue(struct dasd_block *);
  65 static void dasd_device_tasklet(struct dasd_device *);
  66 static void dasd_block_tasklet(struct dasd_block *);
  67 static void do_kick_device(struct work_struct *);
  68 static void do_restore_device(struct work_struct *);
  69 static void do_reload_device(struct work_struct *);
  70 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  71 static void dasd_device_timeout(unsigned long);
  72 static void dasd_block_timeout(unsigned long);
  73 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  74 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  75 static void dasd_profile_exit(struct dasd_profile *);
  76
  77 /*
  78  * SECTION: Operations on the device structure.
  79  */
  80 static wait_queue_head_t dasd_init_waitq;
  81 static wait_queue_head_t dasd_flush_wq;
  82 static wait_queue_head_t generic_waitq;
  83 static wait_queue_head_t shutdown_waitq;
  84
  85 /*
  86  * Allocate memory for a new device structure.
  87  */
  88 struct dasd_device *dasd_alloc_device(void)
  89 {
  90         struct dasd_device *device;
  91
  92         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  93         if (!device)
  94                 return ERR_PTR(-ENOMEM);
  95
  96         /* Get two pages for normal block device operations. */
  97         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  98         if (!device->ccw_mem) {
  99                 kfree(device);
 100                 return ERR_PTR(-ENOMEM);
 101         }
 102         /* Get one page for error recovery. */
 103         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 104         if (!device->erp_mem) {
 105                 free_pages((unsigned long) device->ccw_mem, 1);
 106                 kfree(device);
 107                 return ERR_PTR(-ENOMEM);
 108         }
 109
 110         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 111         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 112         spin_lock_init(&device->mem_lock);
 113         atomic_set(&device->tasklet_scheduled, 0);
 114         tasklet_init(&device->tasklet,
 115                      (void (*)(unsigned long)) dasd_device_tasklet,
 116                      (unsigned long) device);
 117         INIT_LIST_HEAD(&device->ccw_queue);
 118         init_timer(&device->timer);
 119         device->timer.function = dasd_device_timeout;
 120         device->timer.data = (unsigned long) device;
 121         INIT_WORK(&device->kick_work, do_kick_device);
 122         INIT_WORK(&device->restore_device, do_restore_device);
 123         INIT_WORK(&device->reload_device, do_reload_device);
 124         device->state = DASD_STATE_NEW;
 125         device->target = DASD_STATE_NEW;
 126         mutex_init(&device->state_mutex);
 127         spin_lock_init(&device->profile.lock);
 128         return device;
 129 }
 130
 131 /*
 132  * Free memory of a device structure.
 133  */
 134 void dasd_free_device(struct dasd_device *device)
 135 {
 136         kfree(device->private);
 137         free_page((unsigned long) device->erp_mem);
 138         free_pages((unsigned long) device->ccw_mem, 1);
 139         kfree(device);
 140 }
 141
 142 /*
 143  * Allocate memory for a new device structure.
 144  */
 145 struct dasd_block *dasd_alloc_block(void)
 146 {
 147         struct dasd_block *block;
 148
 149         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 150         if (!block)
 151                 return ERR_PTR(-ENOMEM);
 152         /* open_count = 0 means device online but not in use */
 153         atomic_set(&block->open_count, -1);
 154
 155         spin_lock_init(&block->request_queue_lock);
 156         atomic_set(&block->tasklet_scheduled, 0);
 157         tasklet_init(&block->tasklet,
 158                      (void (*)(unsigned long)) dasd_block_tasklet,
 159                      (unsigned long) block);
 160         INIT_LIST_HEAD(&block->ccw_queue);
 161         spin_lock_init(&block->queue_lock);
 162         init_timer(&block->timer);
 163         block->timer.function = dasd_block_timeout;
 164         block->timer.data = (unsigned long) block;
 165         spin_lock_init(&block->profile.lock);
 166
 167         return block;
 168 }
 169 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 170
 171 /*
 172  * Free memory of a device structure.
 173  */
 174 void dasd_free_block(struct dasd_block *block)
 175 {
 176         kfree(block);
 177 }
 178 EXPORT_SYMBOL_GPL(dasd_free_block);
 179
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         int rc;
 186
 187         /*
 188          * As long as the device is not in state DASD_STATE_NEW we want to
 189          * keep the reference count > 0.
 190          */
 191         dasd_get_device(device);
 192
 193         if (device->block) {
 194                 rc = dasd_alloc_queue(device->block);
 195                 if (rc) {
 196                         dasd_put_device(device);
 197                         return rc;
 198                 }
 199         }
 200         device->state = DASD_STATE_KNOWN;
 201         return 0;
 202 }
 203
 204 /*
 205  * Let the system forget about a device.
 206  */
 207 static int dasd_state_known_to_new(struct dasd_device *device)
 208 {
 209         /* Disable extended error reporting for this device. */
 210         dasd_eer_disable(device);
 211         /* Forget the discipline information. */
 212         if (device->discipline) {
 213                 if (device->discipline->uncheck_device)
 214                         device->discipline->uncheck_device(device);
 215                 module_put(device->discipline->owner);
 216         }
 217         device->discipline = NULL;
 218         if (device->base_discipline)
 219                 module_put(device->base_discipline->owner);
 220         device->base_discipline = NULL;
 221         device->state = DASD_STATE_NEW;
 222
 223         if (device->block)
 224                 dasd_free_queue(device->block);
 225
 226         /* Give up reference we took in dasd_state_new_to_known. */
 227         dasd_put_device(device);
 228         return 0;
 229 }
 230
 231 static struct dentry *dasd_debugfs_setup(const char *name,
 232                                          struct dentry *base_dentry)
 233 {
 234         struct dentry *pde;
 235
 236         if (!base_dentry)
 237                 return NULL;
 238         pde = debugfs_create_dir(name, base_dentry);
 239         if (!pde || IS_ERR(pde))
 240                 return NULL;
 241         return pde;
 242 }
 243
 244 /*
 245  * Request the irq line for the device.
 246  */
 247 static int dasd_state_known_to_basic(struct dasd_device *device)
 248 {
 249         struct dasd_block *block = device->block;
 250         int rc = 0;
 251
 252         /* Allocate and register gendisk structure. */
 253         if (block) {
 254                 rc = dasd_gendisk_alloc(block);
 255                 if (rc)
 256                         return rc;
 257                 block->debugfs_dentry =
 258                         dasd_debugfs_setup(block->gdp->disk_name,
 259                                            dasd_debugfs_root_entry);
 260                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 261                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 262                         dasd_profile_on(&device->block->profile);
 263         }
 264         device->debugfs_dentry =
 265                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 266                                    dasd_debugfs_root_entry);
 267         dasd_profile_init(&device->profile, device->debugfs_dentry);
 268
 269         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 270         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 271                                             8 * sizeof(long));
 272         debug_register_view(device->debug_area, &debug_sprintf_view);
 273         debug_set_level(device->debug_area, DBF_WARNING);
 274         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 275
 276         device->state = DASD_STATE_BASIC;
 277
 278         return rc;
 279 }
 280
 281 /*
 282  * Release the irq line for the device. Terminate any running i/o.
 283  */
 284 static int dasd_state_basic_to_known(struct dasd_device *device)
 285 {
 286         int rc;
 287
 288         if (device->discipline->basic_to_known) {
 289                 rc = device->discipline->basic_to_known(device);
 290                 if (rc)
 291                         return rc;
 292         }
 293
 294         if (device->block) {
 295                 dasd_profile_exit(&device->block->profile);
 296                 debugfs_remove(device->block->debugfs_dentry);
 297                 dasd_gendisk_free(device->block);
 298                 dasd_block_clear_timer(device->block);
 299         }
 300         rc = dasd_flush_device_queue(device);
 301         if (rc)
 302                 return rc;
 303         dasd_device_clear_timer(device);
 304         dasd_profile_exit(&device->profile);
 305         debugfs_remove(device->debugfs_dentry);
 306         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 307         if (device->debug_area != NULL) {
 308                 debug_unregister(device->debug_area);
 309                 device->debug_area = NULL;
 310         }
 311         device->state = DASD_STATE_KNOWN;
 312         return 0;
 313 }
 314
 315 /*
 316  * Do the initial analysis. The do_analysis function may return
 317  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 318  * until the discipline decides to continue the startup sequence
 319  * by calling the function dasd_change_state. The eckd disciplines
 320  * uses this to start a ccw that detects the format. The completion
 321  * interrupt for this detection ccw uses the kernel event daemon to
 322  * trigger the call to dasd_change_state. All this is done in the
 323  * discipline code, see dasd_eckd.c.
 324  * After the analysis ccw is done (do_analysis returned 0) the block
 325  * device is setup.
 326  * In case the analysis returns an error, the device setup is stopped
 327  * (a fake disk was already added to allow formatting).
 328  */
 329 static int dasd_state_basic_to_ready(struct dasd_device *device)
 330 {
 331         int rc;
 332         struct dasd_block *block;
 333
 334         rc = 0;
 335         block = device->block;
 336         /* make disk known with correct capacity */
 337         if (block) {
 338                 if (block->base->discipline->do_analysis != NULL)
 339                         rc = block->base->discipline->do_analysis(block);
 340                 if (rc) {
 341                         if (rc != -EAGAIN) {
 342                                 device->state = DASD_STATE_UNFMT;
 343                                 goto out;
 344                         }
 345                         return rc;
 346                 }
 347                 dasd_setup_queue(block);
 348                 set_capacity(block->gdp,
 349                              block->blocks << block->s2b_shift);
 350                 device->state = DASD_STATE_READY;
 351                 rc = dasd_scan_partitions(block);
 352                 if (rc) {
 353                         device->state = DASD_STATE_BASIC;
 354                         return rc;
 355                 }
 356         } else {
 357                 device->state = DASD_STATE_READY;
 358         }
 359 out:
 360         if (device->discipline->basic_to_ready)
 361                 rc = device->discipline->basic_to_ready(device);
 362         return rc;
 363 }
 364
 365 static inline
 366 int _wait_for_empty_queues(struct dasd_device *device)
 367 {
 368         if (device->block)
 369                 return list_empty(&device->ccw_queue) &&
 370                         list_empty(&device->block->ccw_queue);
 371         else
 372                 return list_empty(&device->ccw_queue);
 373 }
 374
 375 /*
 376  * Remove device from block device layer. Destroy dirty buffers.
 377  * Forget format information. Check if the target level is basic
 378  * and if it is create fake disk for formatting.
 379  */
 380 static int dasd_state_ready_to_basic(struct dasd_device *device)
 381 {
 382         int rc;
 383
 384         device->state = DASD_STATE_BASIC;
 385         if (device->block) {
 386                 struct dasd_block *block = device->block;
 387                 rc = dasd_flush_block_queue(block);
 388                 if (rc) {
 389                         device->state = DASD_STATE_READY;
 390                         return rc;
 391                 }
 392                 dasd_flush_request_queue(block);
 393                 dasd_destroy_partitions(block);
 394                 block->blocks = 0;
 395                 block->bp_block = 0;
 396                 block->s2b_shift = 0;
 397         }
 398         return 0;
 399 }
 400
 401 /*
 402  * Back to basic.
 403  */
 404 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 405 {
 406         device->state = DASD_STATE_BASIC;
 407         return 0;
 408 }
 409
 410 /*
 411  * Make the device online and schedule the bottom half to start
 412  * the requeueing of requests from the linux request queue to the
 413  * ccw queue.
 414  */
 415 static int
 416 dasd_state_ready_to_online(struct dasd_device * device)
 417 {
 418         struct gendisk *disk;
 419         struct disk_part_iter piter;
 420         struct hd_struct *part;
 421
 422         device->state = DASD_STATE_ONLINE;
 423         if (device->block) {
 424                 dasd_schedule_block_bh(device->block);
 425                 if ((device->features & DASD_FEATURE_USERAW)) {
 426                         disk = device->block->gdp;
 427                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 428                         return 0;
 429                 }
 430                 disk = device->block->bdev->bd_disk;
 431                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 432                 while ((part = disk_part_iter_next(&piter)))
 433                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 434                 disk_part_iter_exit(&piter);
 435         }
 436         return 0;
 437 }
 438
 439 /*
 440  * Stop the requeueing of requests again.
 441  */
 442 static int dasd_state_online_to_ready(struct dasd_device *device)
 443 {
 444         int rc;
 445         struct gendisk *disk;
 446         struct disk_part_iter piter;
 447         struct hd_struct *part;
 448
 449         if (device->discipline->online_to_ready) {
 450                 rc = device->discipline->online_to_ready(device);
 451                 if (rc)
 452                         return rc;
 453         }
 454
 455         device->state = DASD_STATE_READY;
 456         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 457                 disk = device->block->bdev->bd_disk;
 458                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 459                 while ((part = disk_part_iter_next(&piter)))
 460                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 461                 disk_part_iter_exit(&piter);
 462         }
 463         return 0;
 464 }
 465
 466 /*
 467  * Device startup state changes.
 468  */
 469 static int dasd_increase_state(struct dasd_device *device)
 470 {
 471         int rc;
 472
 473         rc = 0;
 474         if (device->state == DASD_STATE_NEW &&
 475             device->target >= DASD_STATE_KNOWN)
 476                 rc = dasd_state_new_to_known(device);
 477
 478         if (!rc &&
 479             device->state == DASD_STATE_KNOWN &&
 480             device->target >= DASD_STATE_BASIC)
 481                 rc = dasd_state_known_to_basic(device);
 482
 483         if (!rc &&
 484             device->state == DASD_STATE_BASIC &&
 485             device->target >= DASD_STATE_READY)
 486                 rc = dasd_state_basic_to_ready(device);
 487
 488         if (!rc &&
 489             device->state == DASD_STATE_UNFMT &&
 490             device->target > DASD_STATE_UNFMT)
 491                 rc = -EPERM;
 492
 493         if (!rc &&
 494             device->state == DASD_STATE_READY &&
 495             device->target >= DASD_STATE_ONLINE)
 496                 rc = dasd_state_ready_to_online(device);
 497
 498         return rc;
 499 }
 500
 501 /*
 502  * Device shutdown state changes.
 503  */
 504 static int dasd_decrease_state(struct dasd_device *device)
 505 {
 506         int rc;
 507
 508         rc = 0;
 509         if (device->state == DASD_STATE_ONLINE &&
 510             device->target <= DASD_STATE_READY)
 511                 rc = dasd_state_online_to_ready(device);
 512
 513         if (!rc &&
 514             device->state == DASD_STATE_READY &&
 515             device->target <= DASD_STATE_BASIC)
 516                 rc = dasd_state_ready_to_basic(device);
 517
 518         if (!rc &&
 519             device->state == DASD_STATE_UNFMT &&
 520             device->target <= DASD_STATE_BASIC)
 521                 rc = dasd_state_unfmt_to_basic(device);
 522
 523         if (!rc &&
 524             device->state == DASD_STATE_BASIC &&
 525             device->target <= DASD_STATE_KNOWN)
 526                 rc = dasd_state_basic_to_known(device);
 527
 528         if (!rc &&
 529             device->state == DASD_STATE_KNOWN &&
 530             device->target <= DASD_STATE_NEW)
 531                 rc = dasd_state_known_to_new(device);
 532
 533         return rc;
 534 }
 535
 536 /*
 537  * This is the main startup/shutdown routine.
 538  */
 539 static void dasd_change_state(struct dasd_device *device)
 540 {
 541         int rc;
 542
 543         if (device->state == device->target)
 544                 /* Already where we want to go today... */
 545                 return;
 546         if (device->state < device->target)
 547                 rc = dasd_increase_state(device);
 548         else
 549                 rc = dasd_decrease_state(device);
 550         if (rc == -EAGAIN)
 551                 return;
 552         if (rc)
 553                 device->target = device->state;
 554
 555         /* let user-space know that the device status changed */
 556         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 557
 558         if (device->state == device->target)
 559                 wake_up(&dasd_init_waitq);
 560 }
 561
 562 /*
 563  * Kick starter for devices that did not complete the startup/shutdown
 564  * procedure or were sleeping because of a pending state.
 565  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 566  * event daemon.
 567  */
 568 static void do_kick_device(struct work_struct *work)
 569 {
 570         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 571         mutex_lock(&device->state_mutex);
 572         dasd_change_state(device);
 573         mutex_unlock(&device->state_mutex);
 574         dasd_schedule_device_bh(device);
 575         dasd_put_device(device);
 576 }
 577
 578 void dasd_kick_device(struct dasd_device *device)
 579 {
 580         dasd_get_device(device);
 581         /* queue call to dasd_kick_device to the kernel event daemon. */
 582         schedule_work(&device->kick_work);
 583 }
 584 EXPORT_SYMBOL(dasd_kick_device);
 585
 586 /*
 587  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 588  * event daemon.
 589  */
 590 static void do_reload_device(struct work_struct *work)
 591 {
 592         struct dasd_device *device = container_of(work, struct dasd_device,
 593                                                   reload_device);
 594         device->discipline->reload(device);
 595         dasd_put_device(device);
 596 }
 597
 598 void dasd_reload_device(struct dasd_device *device)
 599 {
 600         dasd_get_device(device);
 601         /* queue call to dasd_reload_device to the kernel event daemon. */
 602         schedule_work(&device->reload_device);
 603 }
 604 EXPORT_SYMBOL(dasd_reload_device);
 605
 606 /*
 607  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 608  * event daemon.
 609  */
 610 static void do_restore_device(struct work_struct *work)
 611 {
 612         struct dasd_device *device = container_of(work, struct dasd_device,
 613                                                   restore_device);
 614         device->cdev->drv->restore(device->cdev);
 615         dasd_put_device(device);
 616 }
 617
 618 void dasd_restore_device(struct dasd_device *device)
 619 {
 620         dasd_get_device(device);
 621         /* queue call to dasd_restore_device to the kernel event daemon. */
 622         schedule_work(&device->restore_device);
 623 }
 624
 625 /*
 626  * Set the target state for a device and starts the state change.
 627  */
 628 void dasd_set_target_state(struct dasd_device *device, int target)
 629 {
 630         dasd_get_device(device);
 631         mutex_lock(&device->state_mutex);
 632         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 633         if (dasd_probeonly && target > DASD_STATE_READY)
 634                 target = DASD_STATE_READY;
 635         if (device->target != target) {
 636                 if (device->state == target)
 637                         wake_up(&dasd_init_waitq);
 638                 device->target = target;
 639         }
 640         if (device->state != device->target)
 641                 dasd_change_state(device);
 642         mutex_unlock(&device->state_mutex);
 643         dasd_put_device(device);
 644 }
 645 EXPORT_SYMBOL(dasd_set_target_state);
 646
 647 /*
 648  * Enable devices with device numbers in [from..to].
 649  */
 650 static inline int _wait_for_device(struct dasd_device *device)
 651 {
 652         return (device->state == device->target);
 653 }
 654
 655 void dasd_enable_device(struct dasd_device *device)
 656 {
 657         dasd_set_target_state(device, DASD_STATE_ONLINE);
 658         if (device->state <= DASD_STATE_KNOWN)
 659                 /* No discipline for device found. */
 660                 dasd_set_target_state(device, DASD_STATE_NEW);
 661         /* Now wait for the devices to come up. */
 662         wait_event(dasd_init_waitq, _wait_for_device(device));
 663
 664         dasd_reload_device(device);
 665         if (device->discipline->kick_validate)
 666                 device->discipline->kick_validate(device);
 667 }
 668 EXPORT_SYMBOL(dasd_enable_device);
 669
 670 /*
 671  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 672  */
 673
 674 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 675
 676 #ifdef CONFIG_DASD_PROFILE
 677 struct dasd_profile dasd_global_profile = {
 678         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 679 };
 680 static struct dentry *dasd_debugfs_global_entry;
 681
 682 /*
 683  * Add profiling information for cqr before execution.
 684  */
 685 static void dasd_profile_start(struct dasd_block *block,
 686                                struct dasd_ccw_req *cqr,
 687                                struct request *req)
 688 {
 689         struct list_head *l;
 690         unsigned int counter;
 691         struct dasd_device *device;
 692
 693         /* count the length of the chanq for statistics */
 694         counter = 0;
 695         if (dasd_global_profile_level || block->profile.data)
 696                 list_for_each(l, &block->ccw_queue)
 697                         if (++counter >= 31)
 698                                 break;
 699
 700         spin_lock(&dasd_global_profile.lock);
 701         if (dasd_global_profile.data) {
 702                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 703                 if (rq_data_dir(req) == READ)
 704                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 705         }
 706         spin_unlock(&dasd_global_profile.lock);
 707
 708         spin_lock(&block->profile.lock);
 709         if (block->profile.data) {
 710                 block->profile.data->dasd_io_nr_req[counter]++;
 711                 if (rq_data_dir(req) == READ)
 712                         block->profile.data->dasd_read_nr_req[counter]++;
 713         }
 714         spin_unlock(&block->profile.lock);
 715
 716         /*
 717          * We count the request for the start device, even though it may run on
 718          * some other device due to error recovery. This way we make sure that
 719          * we count each request only once.
 720          */
 721         device = cqr->startdev;
 722         if (device->profile.data) {
 723                 counter = 1; /* request is not yet queued on the start device */
 724                 list_for_each(l, &device->ccw_queue)
 725                         if (++counter >= 31)
 726                                 break;
 727         }
 728         spin_lock(&device->profile.lock);
 729         if (device->profile.data) {
 730                 device->profile.data->dasd_io_nr_req[counter]++;
 731                 if (rq_data_dir(req) == READ)
 732                         device->profile.data->dasd_read_nr_req[counter]++;
 733         }
 734         spin_unlock(&device->profile.lock);
 735 }
 736
 737 /*
 738  * Add profiling information for cqr after execution.
 739  */
 740
 741 #define dasd_profile_counter(value, index)                         \
 742 {                                                                  \
 743         for (index = 0; index < 31 && value >> (2+index); index++) \
 744                 ;                                                  \
 745 }
 746
 747 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 748                                       int is_alias,
 749                                       int is_tpm,
 750                                       int is_read,
 751                                       long sectors,
 752                                       int sectors_ind,
 753                                       int tottime_ind,
 754                                       int tottimeps_ind,
 755                                       int strtime_ind,
 756                                       int irqtime_ind,
 757                                       int irqtimeps_ind,
 758                                       int endtime_ind)
 759 {
 760         /* in case of an overflow, reset the whole profile */
 761         if (data->dasd_io_reqs == UINT_MAX) {
 762                         memset(data, 0, sizeof(*data));
 763                         getnstimeofday(&data->starttod);
 764         }
 765         data->dasd_io_reqs++;
 766         data->dasd_io_sects += sectors;
 767         if (is_alias)
 768                 data->dasd_io_alias++;
 769         if (is_tpm)
 770                 data->dasd_io_tpm++;
 771
 772         data->dasd_io_secs[sectors_ind]++;
 773         data->dasd_io_times[tottime_ind]++;
 774         data->dasd_io_timps[tottimeps_ind]++;
 775         data->dasd_io_time1[strtime_ind]++;
 776         data->dasd_io_time2[irqtime_ind]++;
 777         data->dasd_io_time2ps[irqtimeps_ind]++;
 778         data->dasd_io_time3[endtime_ind]++;
 779
 780         if (is_read) {
 781                 data->dasd_read_reqs++;
 782                 data->dasd_read_sects += sectors;
 783                 if (is_alias)
 784                         data->dasd_read_alias++;
 785                 if (is_tpm)
 786                         data->dasd_read_tpm++;
 787                 data->dasd_read_secs[sectors_ind]++;
 788                 data->dasd_read_times[tottime_ind]++;
 789                 data->dasd_read_time1[strtime_ind]++;
 790                 data->dasd_read_time2[irqtime_ind]++;
 791                 data->dasd_read_time3[endtime_ind]++;
 792         }
 793 }
 794
 795 static void dasd_profile_end(struct dasd_block *block,
 796                              struct dasd_ccw_req *cqr,
 797                              struct request *req)
 798 {
 799         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 800         long tottimeps, sectors;
 801         struct dasd_device *device;
 802         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 803         int irqtime_ind, irqtimeps_ind, endtime_ind;
 804
 805         device = cqr->startdev;
 806         if (!(dasd_global_profile_level ||
 807               block->profile.data ||
 808               device->profile.data))
 809                 return;
 810
 811         sectors = blk_rq_sectors(req);
 812         if (!cqr->buildclk || !cqr->startclk ||
 813             !cqr->stopclk || !cqr->endclk ||
 814             !sectors)
 815                 return;
 816
 817         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 818         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 819         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 820         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 821         tottimeps = tottime / sectors;
 822
 823         dasd_profile_counter(sectors, sectors_ind);
 824         dasd_profile_counter(tottime, tottime_ind);
 825         dasd_profile_counter(tottimeps, tottimeps_ind);
 826         dasd_profile_counter(strtime, strtime_ind);
 827         dasd_profile_counter(irqtime, irqtime_ind);
 828         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 829         dasd_profile_counter(endtime, endtime_ind);
 830
 831         spin_lock(&dasd_global_profile.lock);
 832         if (dasd_global_profile.data) {
 833                 dasd_profile_end_add_data(dasd_global_profile.data,
 834                                           cqr->startdev != block->base,
 835                                           cqr->cpmode == 1,
 836                                           rq_data_dir(req) == READ,
 837                                           sectors, sectors_ind, tottime_ind,
 838                                           tottimeps_ind, strtime_ind,
 839                                           irqtime_ind, irqtimeps_ind,
 840                                           endtime_ind);
 841         }
 842         spin_unlock(&dasd_global_profile.lock);
 843
 844         spin_lock(&block->profile.lock);
 845         if (block->profile.data)
 846                 dasd_profile_end_add_data(block->profile.data,
 847                                           cqr->startdev != block->base,
 848                                           cqr->cpmode == 1,
 849                                           rq_data_dir(req) == READ,
 850                                           sectors, sectors_ind, tottime_ind,
 851                                           tottimeps_ind, strtime_ind,
 852                                           irqtime_ind, irqtimeps_ind,
 853                                           endtime_ind);
 854         spin_unlock(&block->profile.lock);
 855
 856         spin_lock(&device->profile.lock);
 857         if (device->profile.data)
 858                 dasd_profile_end_add_data(device->profile.data,
 859                                           cqr->startdev != block->base,
 860                                           cqr->cpmode == 1,
 861                                           rq_data_dir(req) == READ,
 862                                           sectors, sectors_ind, tottime_ind,
 863                                           tottimeps_ind, strtime_ind,
 864                                           irqtime_ind, irqtimeps_ind,
 865                                           endtime_ind);
 866         spin_unlock(&device->profile.lock);
 867 }
 868
 869 void dasd_profile_reset(struct dasd_profile *profile)
 870 {
 871         struct dasd_profile_info *data;
 872
 873         spin_lock_bh(&profile->lock);
 874         data = profile->data;
 875         if (!data) {
 876                 spin_unlock_bh(&profile->lock);
 877                 return;
 878         }
 879         memset(data, 0, sizeof(*data));
 880         getnstimeofday(&data->starttod);
 881         spin_unlock_bh(&profile->lock);
 882 }
 883
 884 int dasd_profile_on(struct dasd_profile *profile)
 885 {
 886         struct dasd_profile_info *data;
 887
 888         data = kzalloc(sizeof(*data), GFP_KERNEL);
 889         if (!data)
 890                 return -ENOMEM;
 891         spin_lock_bh(&profile->lock);
 892         if (profile->data) {
 893                 spin_unlock_bh(&profile->lock);
 894                 kfree(data);
 895                 return 0;
 896         }
 897         getnstimeofday(&data->starttod);
 898         profile->data = data;
 899         spin_unlock_bh(&profile->lock);
 900         return 0;
 901 }
 902
 903 void dasd_profile_off(struct dasd_profile *profile)
 904 {
 905         spin_lock_bh(&profile->lock);
 906         kfree(profile->data);
 907         profile->data = NULL;
 908         spin_unlock_bh(&profile->lock);
 909 }
 910
 911 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 912 {
 913         char *buffer;
 914
 915         buffer = vmalloc(user_len + 1);
 916         if (buffer == NULL)
 917                 return ERR_PTR(-ENOMEM);
 918         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 919                 vfree(buffer);
 920                 return ERR_PTR(-EFAULT);
 921         }
 922         /* got the string, now strip linefeed. */
 923         if (buffer[user_len - 1] == '\n')
 924                 buffer[user_len - 1] = 0;
 925         else
 926                 buffer[user_len] = 0;
 927         return buffer;
 928 }
 929
 930 static ssize_t dasd_stats_write(struct file *file,
 931                                 const char __user *user_buf,
 932                                 size_t user_len, loff_t *pos)
 933 {
 934         char *buffer, *str;
 935         int rc;
 936         struct seq_file *m = (struct seq_file *)file->private_data;
 937         struct dasd_profile *prof = m->private;
 938
 939         if (user_len > 65536)
 940                 user_len = 65536;
 941         buffer = dasd_get_user_string(user_buf, user_len);
 942         if (IS_ERR(buffer))
 943                 return PTR_ERR(buffer);
 944
 945         str = skip_spaces(buffer);
 946         rc = user_len;
 947         if (strncmp(str, "reset", 5) == 0) {
 948                 dasd_profile_reset(prof);
 949         } else if (strncmp(str, "on", 2) == 0) {
 950                 rc = dasd_profile_on(prof);
 951                 if (rc)
 952                         goto out;
 953                 rc = user_len;
 954                 if (prof == &dasd_global_profile) {
 955                         dasd_profile_reset(prof);
 956                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 957                 }
 958         } else if (strncmp(str, "off", 3) == 0) {
 959                 if (prof == &dasd_global_profile)
 960                         dasd_global_profile_level = DASD_PROFILE_OFF;
 961                 dasd_profile_off(prof);
 962         } else
 963                 rc = -EINVAL;
 964 out:
 965         vfree(buffer);
 966         return rc;
 967 }
 968
 969 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 970 {
 971         int i;
 972
 973         for (i = 0; i < 32; i++)
 974                 seq_printf(m, "%u ", array[i]);
 975         seq_putc(m, '\n');
 976 }
 977
 978 static void dasd_stats_seq_print(struct seq_file *m,
 979                                  struct dasd_profile_info *data)
 980 {
 981         seq_printf(m, "start_time %ld.%09ld\n",
 982                    data->starttod.tv_sec, data->starttod.tv_nsec);
 983         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 984         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 985         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 986         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 987         seq_puts(m, "histogram_sectors ");
 988         dasd_stats_array(m, data->dasd_io_secs);
 989         seq_puts(m, "histogram_io_times ");
 990         dasd_stats_array(m, data->dasd_io_times);
 991         seq_puts(m, "histogram_io_times_weighted ");
 992         dasd_stats_array(m, data->dasd_io_timps);
 993         seq_puts(m, "histogram_time_build_to_ssch ");
 994         dasd_stats_array(m, data->dasd_io_time1);
 995         seq_puts(m, "histogram_time_ssch_to_irq ");
 996         dasd_stats_array(m, data->dasd_io_time2);
 997         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
 998         dasd_stats_array(m, data->dasd_io_time2ps);
 999         seq_puts(m, "histogram_time_irq_to_end ");
1000         dasd_stats_array(m, data->dasd_io_time3);
1001         seq_puts(m, "histogram_ccw_queue_length ");
1002         dasd_stats_array(m, data->dasd_io_nr_req);
1003         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1004         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1005         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1006         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1007         seq_puts(m, "histogram_read_sectors ");
1008         dasd_stats_array(m, data->dasd_read_secs);
1009         seq_puts(m, "histogram_read_times ");
1010         dasd_stats_array(m, data->dasd_read_times);
1011         seq_puts(m, "histogram_read_time_build_to_ssch ");
1012         dasd_stats_array(m, data->dasd_read_time1);
1013         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1014         dasd_stats_array(m, data->dasd_read_time2);
1015         seq_puts(m, "histogram_read_time_irq_to_end ");
1016         dasd_stats_array(m, data->dasd_read_time3);
1017         seq_puts(m, "histogram_read_ccw_queue_length ");
1018         dasd_stats_array(m, data->dasd_read_nr_req);
1019 }
1020
1021 static int dasd_stats_show(struct seq_file *m, void *v)
1022 {
1023         struct dasd_profile *profile;
1024         struct dasd_profile_info *data;
1025
1026         profile = m->private;
1027         spin_lock_bh(&profile->lock);
1028         data = profile->data;
1029         if (!data) {
1030                 spin_unlock_bh(&profile->lock);
1031                 seq_puts(m, "disabled\n");
1032                 return 0;
1033         }
1034         dasd_stats_seq_print(m, data);
1035         spin_unlock_bh(&profile->lock);
1036         return 0;
1037 }
1038
1039 static int dasd_stats_open(struct inode *inode, struct file *file)
1040 {
1041         struct dasd_profile *profile = inode->i_private;
1042         return single_open(file, dasd_stats_show, profile);
1043 }
1044
1045 static const struct file_operations dasd_stats_raw_fops = {
1046         .owner          = THIS_MODULE,
1047         .open           = dasd_stats_open,
1048         .read           = seq_read,
1049         .llseek         = seq_lseek,
1050         .release        = single_release,
1051         .write          = dasd_stats_write,
1052 };
1053
1054 static void dasd_profile_init(struct dasd_profile *profile,
1055                               struct dentry *base_dentry)
1056 {
1057         umode_t mode;
1058         struct dentry *pde;
1059
1060         if (!base_dentry)
1061                 return;
1062         profile->dentry = NULL;
1063         profile->data = NULL;
1064         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1065         pde = debugfs_create_file("statistics", mode, base_dentry,
1066                                   profile, &dasd_stats_raw_fops);
1067         if (pde && !IS_ERR(pde))
1068                 profile->dentry = pde;
1069         return;
1070 }
1071
1072 static void dasd_profile_exit(struct dasd_profile *profile)
1073 {
1074         dasd_profile_off(profile);
1075         debugfs_remove(profile->dentry);
1076         profile->dentry = NULL;
1077 }
1078
1079 static void dasd_statistics_removeroot(void)
1080 {
1081         dasd_global_profile_level = DASD_PROFILE_OFF;
1082         dasd_profile_exit(&dasd_global_profile);
1083         debugfs_remove(dasd_debugfs_global_entry);
1084         debugfs_remove(dasd_debugfs_root_entry);
1085 }
1086
1087 static void dasd_statistics_createroot(void)
1088 {
1089         struct dentry *pde;
1090
1091         dasd_debugfs_root_entry = NULL;
1092         pde = debugfs_create_dir("dasd", NULL);
1093         if (!pde || IS_ERR(pde))
1094                 goto error;
1095         dasd_debugfs_root_entry = pde;
1096         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1097         if (!pde || IS_ERR(pde))
1098                 goto error;
1099         dasd_debugfs_global_entry = pde;
1100         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1101         return;
1102
1103 error:
1104         DBF_EVENT(DBF_ERR, "%s",
1105                   "Creation of the dasd debugfs interface failed");
1106         dasd_statistics_removeroot();
1107         return;
1108 }
1109
1110 #else
1111 #define dasd_profile_start(block, cqr, req) do {} while (0)
1112 #define dasd_profile_end(block, cqr, req) do {} while (0)
1113
1114 static void dasd_statistics_createroot(void)
1115 {
1116         return;
1117 }
1118
1119 static void dasd_statistics_removeroot(void)
1120 {
1121         return;
1122 }
1123
1124 int dasd_stats_generic_show(struct seq_file *m, void *v)
1125 {
1126         seq_puts(m, "Statistics are not activated in this kernel\n");
1127         return 0;
1128 }
1129
1130 static void dasd_profile_init(struct dasd_profile *profile,
1131                               struct dentry *base_dentry)
1132 {
1133         return;
1134 }
1135
1136 static void dasd_profile_exit(struct dasd_profile *profile)
1137 {
1138         return;
1139 }
1140
1141 int dasd_profile_on(struct dasd_profile *profile)
1142 {
1143         return 0;
1144 }
1145
1146 #endif                          /* CONFIG_DASD_PROFILE */
1147
1148 /*
1149  * Allocate memory for a channel program with 'cplength' channel
1150  * command words and 'datasize' additional space. There are two
1151  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1152  * memory and 2) dasd_smalloc_request uses the static ccw memory
1153  * that gets allocated for each device.
1154  */
1155 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1156                                           int datasize,
1157                                           struct dasd_device *device)
1158 {
1159         struct dasd_ccw_req *cqr;
1160
1161         /* Sanity checks */
1162         BUG_ON(datasize > PAGE_SIZE ||
1163              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1164
1165         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1166         if (cqr == NULL)
1167                 return ERR_PTR(-ENOMEM);
1168         cqr->cpaddr = NULL;
1169         if (cplength > 0) {
1170                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1171                                       GFP_ATOMIC | GFP_DMA);
1172                 if (cqr->cpaddr == NULL) {
1173                         kfree(cqr);
1174                         return ERR_PTR(-ENOMEM);
1175                 }
1176         }
1177         cqr->data = NULL;
1178         if (datasize > 0) {
1179                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1180                 if (cqr->data == NULL) {
1181                         kfree(cqr->cpaddr);
1182                         kfree(cqr);
1183                         return ERR_PTR(-ENOMEM);
1184                 }
1185         }
1186         cqr->magic =  magic;
1187         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1188         dasd_get_device(device);
1189         return cqr;
1190 }
1191 EXPORT_SYMBOL(dasd_kmalloc_request);
1192
1193 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1194                                           int datasize,
1195                                           struct dasd_device *device)
1196 {
1197         unsigned long flags;
1198         struct dasd_ccw_req *cqr;
1199         char *data;
1200         int size;
1201
1202         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1203         if (cplength > 0)
1204                 size += cplength * sizeof(struct ccw1);
1205         if (datasize > 0)
1206                 size += datasize;
1207         spin_lock_irqsave(&device->mem_lock, flags);
1208         cqr = (struct dasd_ccw_req *)
1209                 dasd_alloc_chunk(&device->ccw_chunks, size);
1210         spin_unlock_irqrestore(&device->mem_lock, flags);
1211         if (cqr == NULL)
1212                 return ERR_PTR(-ENOMEM);
1213         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1214         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1215         cqr->cpaddr = NULL;
1216         if (cplength > 0) {
1217                 cqr->cpaddr = (struct ccw1 *) data;
1218                 data += cplength*sizeof(struct ccw1);
1219                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1220         }
1221         cqr->data = NULL;
1222         if (datasize > 0) {
1223                 cqr->data = data;
1224                 memset(cqr->data, 0, datasize);
1225         }
1226         cqr->magic = magic;
1227         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1228         dasd_get_device(device);
1229         return cqr;
1230 }
1231 EXPORT_SYMBOL(dasd_smalloc_request);
1232
1233 /*
1234  * Free memory of a channel program. This function needs to free all the
1235  * idal lists that might have been created by dasd_set_cda and the
1236  * struct dasd_ccw_req itself.
1237  */
1238 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1239 {
1240 #ifdef CONFIG_64BIT
1241         struct ccw1 *ccw;
1242
1243         /* Clear any idals used for the request. */
1244         ccw = cqr->cpaddr;
1245         do {
1246                 clear_normalized_cda(ccw);
1247         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1248 #endif
1249         kfree(cqr->cpaddr);
1250         kfree(cqr->data);
1251         kfree(cqr);
1252         dasd_put_device(device);
1253 }
1254 EXPORT_SYMBOL(dasd_kfree_request);
1255
1256 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1257 {
1258         unsigned long flags;
1259
1260         spin_lock_irqsave(&device->mem_lock, flags);
1261         dasd_free_chunk(&device->ccw_chunks, cqr);
1262         spin_unlock_irqrestore(&device->mem_lock, flags);
1263         dasd_put_device(device);
1264 }
1265 EXPORT_SYMBOL(dasd_sfree_request);
1266
1267 /*
1268  * Check discipline magic in cqr.
1269  */
1270 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1271 {
1272         struct dasd_device *device;
1273
1274         if (cqr == NULL)
1275                 return -EINVAL;
1276         device = cqr->startdev;
1277         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1278                 DBF_DEV_EVENT(DBF_WARNING, device,
1279                             " dasd_ccw_req 0x%08x magic doesn't match"
1280                             " discipline 0x%08x",
1281                             cqr->magic,
1282                             *(unsigned int *) device->discipline->name);
1283                 return -EINVAL;
1284         }
1285         return 0;
1286 }
1287
1288 /*
1289  * Terminate the current i/o and set the request to clear_pending.
1290  * Timer keeps device runnig.
1291  * ccw_device_clear can fail if the i/o subsystem
1292  * is in a bad mood.
1293  */
1294 int dasd_term_IO(struct dasd_ccw_req *cqr)
1295 {
1296         struct dasd_device *device;
1297         int retries, rc;
1298         char errorstring[ERRORLENGTH];
1299
1300         /* Check the cqr */
1301         rc = dasd_check_cqr(cqr);
1302         if (rc)
1303                 return rc;
1304         retries = 0;
1305         device = (struct dasd_device *) cqr->startdev;
1306         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1307                 rc = ccw_device_clear(device->cdev, (long) cqr);
1308                 switch (rc) {
1309                 case 0: /* termination successful */
1310                         cqr->status = DASD_CQR_CLEAR_PENDING;
1311                         cqr->stopclk = get_tod_clock();
1312                         cqr->starttime = 0;
1313                         DBF_DEV_EVENT(DBF_DEBUG, device,
1314                                       "terminate cqr %p successful",
1315                                       cqr);
1316                         break;
1317                 case -ENODEV:
1318                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1319                                       "device gone, retry");
1320                         break;
1321                 case -EIO:
1322                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1323                                       "I/O error, retry");
1324                         break;
1325                 case -EINVAL:
1326                         /*
1327                          * device not valid so no I/O could be running
1328                          * handle CQR as termination successful
1329                          */
1330                         cqr->status = DASD_CQR_CLEARED;
1331                         cqr->stopclk = get_tod_clock();
1332                         cqr->starttime = 0;
1333                         /* no retries for invalid devices */
1334                         cqr->retries = -1;
1335                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1336                                       "EINVAL, handle as terminated");
1337                         /* fake rc to success */
1338                         rc = 0;
1339                         break;
1340                 case -EBUSY:
1341                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1342                                       "device busy, retry later");
1343                         break;
1344                 default:
1345                         /* internal error 10 - unknown rc*/
1346                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1347                         dev_err(&device->cdev->dev, "An error occurred in the "
1348                                 "DASD device driver, reason=%s\n", errorstring);
1349                         BUG();
1350                         break;
1351                 }
1352                 retries++;
1353         }
1354         dasd_schedule_device_bh(device);
1355         return rc;
1356 }
1357 EXPORT_SYMBOL(dasd_term_IO);
1358
1359 /*
1360  * Start the i/o. This start_IO can fail if the channel is really busy.
1361  * In that case set up a timer to start the request later.
1362  */
1363 int dasd_start_IO(struct dasd_ccw_req *cqr)
1364 {
1365         struct dasd_device *device;
1366         int rc;
1367         char errorstring[ERRORLENGTH];
1368
1369         /* Check the cqr */
1370         rc = dasd_check_cqr(cqr);
1371         if (rc) {
1372                 cqr->intrc = rc;
1373                 return rc;
1374         }
1375         device = (struct dasd_device *) cqr->startdev;
1376         if (((cqr->block &&
1377               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1378              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1379             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1380                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1381                               "because of stolen lock", cqr);
1382                 cqr->status = DASD_CQR_ERROR;
1383                 cqr->intrc = -EPERM;
1384                 return -EPERM;
1385         }
1386         if (cqr->retries < 0) {
1387                 /* internal error 14 - start_IO run out of retries */
1388                 sprintf(errorstring, "14 %p", cqr);
1389                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1390                         "device driver, reason=%s\n", errorstring);
1391                 cqr->status = DASD_CQR_ERROR;
1392                 return -EIO;
1393         }
1394         cqr->startclk = get_tod_clock();
1395         cqr->starttime = jiffies;
1396         cqr->retries--;
1397         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1398                 cqr->lpm &= device->path_data.opm;
1399                 if (!cqr->lpm)
1400                         cqr->lpm = device->path_data.opm;
1401         }
1402         if (cqr->cpmode == 1) {
1403                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1404                                          (long) cqr, cqr->lpm);
1405         } else {
1406                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1407                                       (long) cqr, cqr->lpm, 0);
1408         }
1409         switch (rc) {
1410         case 0:
1411                 cqr->status = DASD_CQR_IN_IO;
1412                 break;
1413         case -EBUSY:
1414                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1415                               "start_IO: device busy, retry later");
1416                 break;
1417         case -ETIMEDOUT:
1418                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1419                               "start_IO: request timeout, retry later");
1420                 break;
1421         case -EACCES:
1422                 /* -EACCES indicates that the request used only a subset of the
1423                  * available paths and all these paths are gone. If the lpm of
1424                  * this request was only a subset of the opm (e.g. the ppm) then
1425                  * we just do a retry with all available paths.
1426                  * If we already use the full opm, something is amiss, and we
1427                  * need a full path verification.
1428                  */
1429                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1430                         DBF_DEV_EVENT(DBF_WARNING, device,
1431                                       "start_IO: selected paths gone (%x)",
1432                                       cqr->lpm);
1433                 } else if (cqr->lpm != device->path_data.opm) {
1434                         cqr->lpm = device->path_data.opm;
1435                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1436                                       "start_IO: selected paths gone,"
1437                                       " retry on all paths");
1438                 } else {
1439                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1440                                       "start_IO: all paths in opm gone,"
1441                                       " do path verification");
1442                         dasd_generic_last_path_gone(device);
1443                         device->path_data.opm = 0;
1444                         device->path_data.ppm = 0;
1445                         device->path_data.npm = 0;
1446                         device->path_data.tbvpm =
1447                                 ccw_device_get_path_mask(device->cdev);
1448                 }
1449                 break;
1450         case -ENODEV:
1451                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1452                               "start_IO: -ENODEV device gone, retry");
1453                 break;
1454         case -EIO:
1455                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1456                               "start_IO: -EIO device gone, retry");
1457                 break;
1458         case -EINVAL:
1459                 /* most likely caused in power management context */
1460                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1461                               "start_IO: -EINVAL device currently "
1462                               "not accessible");
1463                 break;
1464         default:
1465                 /* internal error 11 - unknown rc */
1466                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1467                 dev_err(&device->cdev->dev,
1468                         "An error occurred in the DASD device driver, "
1469                         "reason=%s\n", errorstring);
1470                 BUG();
1471                 break;
1472         }
1473         cqr->intrc = rc;
1474         return rc;
1475 }
1476 EXPORT_SYMBOL(dasd_start_IO);
1477
1478 /*
1479  * Timeout function for dasd devices. This is used for different purposes
1480  *  1) missing interrupt handler for normal operation
1481  *  2) delayed start of request where start_IO failed with -EBUSY
1482  *  3) timeout for missing state change interrupts
1483  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1484  * DASD_CQR_QUEUED for 2) and 3).
1485  */
1486 static void dasd_device_timeout(unsigned long ptr)
1487 {
1488         unsigned long flags;
1489         struct dasd_device *device;
1490
1491         device = (struct dasd_device *) ptr;
1492         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1493         /* re-activate request queue */
1494         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1495         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1496         dasd_schedule_device_bh(device);
1497 }
1498
1499 /*
1500  * Setup timeout for a device in jiffies.
1501  */
1502 void dasd_device_set_timer(struct dasd_device *device, int expires)
1503 {
1504         if (expires == 0)
1505                 del_timer(&device->timer);
1506         else
1507                 mod_timer(&device->timer, jiffies + expires);
1508 }
1509 EXPORT_SYMBOL(dasd_device_set_timer);
1510
1511 /*
1512  * Clear timeout for a device.
1513  */
1514 void dasd_device_clear_timer(struct dasd_device *device)
1515 {
1516         del_timer(&device->timer);
1517 }
1518 EXPORT_SYMBOL(dasd_device_clear_timer);
1519
1520 static void dasd_handle_killed_request(struct ccw_device *cdev,
1521                                        unsigned long intparm)
1522 {
1523         struct dasd_ccw_req *cqr;
1524         struct dasd_device *device;
1525
1526         if (!intparm)
1527                 return;
1528         cqr = (struct dasd_ccw_req *) intparm;
1529         if (cqr->status != DASD_CQR_IN_IO) {
1530                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1531                                 "invalid status in handle_killed_request: "
1532                                 "%02x", cqr->status);
1533                 return;
1534         }
1535
1536         device = dasd_device_from_cdev_locked(cdev);
1537         if (IS_ERR(device)) {
1538                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1539                                 "unable to get device from cdev");
1540                 return;
1541         }
1542
1543         if (!cqr->startdev ||
1544             device != cqr->startdev ||
1545             strncmp(cqr->startdev->discipline->ebcname,
1546                     (char *) &cqr->magic, 4)) {
1547                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1548                                 "invalid device in request");
1549                 dasd_put_device(device);
1550                 return;
1551         }
1552
1553         /* Schedule request to be retried. */
1554         cqr->status = DASD_CQR_QUEUED;
1555
1556         dasd_device_clear_timer(device);
1557         dasd_schedule_device_bh(device);
1558         dasd_put_device(device);
1559 }
1560
1561 void dasd_generic_handle_state_change(struct dasd_device *device)
1562 {
1563         /* First of all start sense subsystem status request. */
1564         dasd_eer_snss(device);
1565
1566         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1567         dasd_schedule_device_bh(device);
1568         if (device->block)
1569                 dasd_schedule_block_bh(device->block);
1570 }
1571 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1572
1573 /*
1574  * Interrupt handler for "normal" ssch-io based dasd devices.
1575  */
1576 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1577                       struct irb *irb)
1578 {
1579         struct dasd_ccw_req *cqr, *next;
1580         struct dasd_device *device;
1581         unsigned long long now;
1582         int expires;
1583
1584         if (IS_ERR(irb)) {
1585                 switch (PTR_ERR(irb)) {
1586                 case -EIO:
1587                         break;
1588                 case -ETIMEDOUT:
1589                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1590                                         "request timed out\n", __func__);
1591                         break;
1592                 default:
1593                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1594                                         "unknown error %ld\n", __func__,
1595                                         PTR_ERR(irb));
1596                 }
1597                 dasd_handle_killed_request(cdev, intparm);
1598                 return;
1599         }
1600
1601         now = get_tod_clock();
1602         cqr = (struct dasd_ccw_req *) intparm;
1603         /* check for conditions that should be handled immediately */
1604         if (!cqr ||
1605             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1606               scsw_cstat(&irb->scsw) == 0)) {
1607                 if (cqr)
1608                         memcpy(&cqr->irb, irb, sizeof(*irb));
1609                 device = dasd_device_from_cdev_locked(cdev);
1610                 if (IS_ERR(device))
1611                         return;
1612                 /* ignore unsolicited interrupts for DIAG discipline */
1613                 if (device->discipline == dasd_diag_discipline_pointer) {
1614                         dasd_put_device(device);
1615                         return;
1616                 }
1617                 device->discipline->dump_sense_dbf(device, irb, "int");
1618                 if (device->features & DASD_FEATURE_ERPLOG)
1619                         device->discipline->dump_sense(device, cqr, irb);
1620                 device->discipline->check_for_device_change(device, cqr, irb);
1621                 dasd_put_device(device);
1622         }
1623
1624         /* check for for attention message */
1625         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1626                 device = dasd_device_from_cdev_locked(cdev);
1627                 device->discipline->check_attention(device, irb->esw.esw1.lpum);
1628                 dasd_put_device(device);
1629         }
1630
1631         if (!cqr)
1632                 return;
1633
1634         device = (struct dasd_device *) cqr->startdev;
1635         if (!device ||
1636             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1637                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1638                                 "invalid device in request");
1639                 return;
1640         }
1641
1642         /* Check for clear pending */
1643         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1644             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1645                 cqr->status = DASD_CQR_CLEARED;
1646                 dasd_device_clear_timer(device);
1647                 wake_up(&dasd_flush_wq);
1648                 dasd_schedule_device_bh(device);
1649                 return;
1650         }
1651
1652         /* check status - the request might have been killed by dyn detach */
1653         if (cqr->status != DASD_CQR_IN_IO) {
1654                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1655                               "status %02x", dev_name(&cdev->dev), cqr->status);
1656                 return;
1657         }
1658
1659         next = NULL;
1660         expires = 0;
1661         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1662             scsw_cstat(&irb->scsw) == 0) {
1663                 /* request was completed successfully */
1664                 cqr->status = DASD_CQR_SUCCESS;
1665                 cqr->stopclk = now;
1666                 /* Start first request on queue if possible -> fast_io. */
1667                 if (cqr->devlist.next != &device->ccw_queue) {
1668                         next = list_entry(cqr->devlist.next,
1669                                           struct dasd_ccw_req, devlist);
1670                 }
1671         } else {  /* error */
1672                 /*
1673                  * If we don't want complex ERP for this request, then just
1674                  * reset this and retry it in the fastpath
1675                  */
1676                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1677                     cqr->retries > 0) {
1678                         if (cqr->lpm == device->path_data.opm)
1679                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1680                                               "default ERP in fastpath "
1681                                               "(%i retries left)",
1682                                               cqr->retries);
1683                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1684                                 cqr->lpm = device->path_data.opm;
1685                         cqr->status = DASD_CQR_QUEUED;
1686                         next = cqr;
1687                 } else
1688                         cqr->status = DASD_CQR_ERROR;
1689         }
1690         if (next && (next->status == DASD_CQR_QUEUED) &&
1691             (!device->stopped)) {
1692                 if (device->discipline->start_IO(next) == 0)
1693                         expires = next->expires;
1694         }
1695         if (expires != 0)
1696                 dasd_device_set_timer(device, expires);
1697         else
1698                 dasd_device_clear_timer(device);
1699         dasd_schedule_device_bh(device);
1700 }
1701 EXPORT_SYMBOL(dasd_int_handler);
1702
1703 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1704 {
1705         struct dasd_device *device;
1706
1707         device = dasd_device_from_cdev_locked(cdev);
1708
1709         if (IS_ERR(device))
1710                 goto out;
1711         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1712            device->state != device->target ||
1713            !device->discipline->check_for_device_change){
1714                 dasd_put_device(device);
1715                 goto out;
1716         }
1717         if (device->discipline->dump_sense_dbf)
1718                 device->discipline->dump_sense_dbf(device, irb, "uc");
1719         device->discipline->check_for_device_change(device, NULL, irb);
1720         dasd_put_device(device);
1721 out:
1722         return UC_TODO_RETRY;
1723 }
1724 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1725
1726 /*
1727  * If we have an error on a dasd_block layer request then we cancel
1728  * and return all further requests from the same dasd_block as well.
1729  */
1730 static void __dasd_device_recovery(struct dasd_device *device,
1731                                    struct dasd_ccw_req *ref_cqr)
1732 {
1733         struct list_head *l, *n;
1734         struct dasd_ccw_req *cqr;
1735
1736         /*
1737          * only requeue request that came from the dasd_block layer
1738          */
1739         if (!ref_cqr->block)
1740                 return;
1741
1742         list_for_each_safe(l, n, &device->ccw_queue) {
1743                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1744                 if (cqr->status == DASD_CQR_QUEUED &&
1745                     ref_cqr->block == cqr->block) {
1746                         cqr->status = DASD_CQR_CLEARED;
1747                 }
1748         }
1749 };
1750
1751 /*
1752  * Remove those ccw requests from the queue that need to be returned
1753  * to the upper layer.
1754  */
1755 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1756                                             struct list_head *final_queue)
1757 {
1758         struct list_head *l, *n;
1759         struct dasd_ccw_req *cqr;
1760
1761         /* Process request with final status. */
1762         list_for_each_safe(l, n, &device->ccw_queue) {
1763                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1764
1765                 /* Skip any non-final request. */
1766                 if (cqr->status == DASD_CQR_QUEUED ||
1767                     cqr->status == DASD_CQR_IN_IO ||
1768                     cqr->status == DASD_CQR_CLEAR_PENDING)
1769                         continue;
1770                 if (cqr->status == DASD_CQR_ERROR) {
1771                         __dasd_device_recovery(device, cqr);
1772                 }
1773                 /* Rechain finished requests to final queue */
1774                 list_move_tail(&cqr->devlist, final_queue);
1775         }
1776 }
1777
1778 /*
1779  * the cqrs from the final queue are returned to the upper layer
1780  * by setting a dasd_block state and calling the callback function
1781  */
1782 static void __dasd_device_process_final_queue(struct dasd_device *device,
1783                                               struct list_head *final_queue)
1784 {
1785         struct list_head *l, *n;
1786         struct dasd_ccw_req *cqr;
1787         struct dasd_block *block;
1788         void (*callback)(struct dasd_ccw_req *, void *data);
1789         void *callback_data;
1790         char errorstring[ERRORLENGTH];
1791
1792         list_for_each_safe(l, n, final_queue) {
1793                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1794                 list_del_init(&cqr->devlist);
1795                 block = cqr->block;
1796                 callback = cqr->callback;
1797                 callback_data = cqr->callback_data;
1798                 if (block)
1799                         spin_lock_bh(&block->queue_lock);
1800                 switch (cqr->status) {
1801                 case DASD_CQR_SUCCESS:
1802                         cqr->status = DASD_CQR_DONE;
1803                         break;
1804                 case DASD_CQR_ERROR:
1805                         cqr->status = DASD_CQR_NEED_ERP;
1806                         break;
1807                 case DASD_CQR_CLEARED:
1808                         cqr->status = DASD_CQR_TERMINATED;
1809                         break;
1810                 default:
1811                         /* internal error 12 - wrong cqr status*/
1812                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1813                         dev_err(&device->cdev->dev,
1814                                 "An error occurred in the DASD device driver, "
1815                                 "reason=%s\n", errorstring);
1816                         BUG();
1817                 }
1818                 if (cqr->callback != NULL)
1819                         (callback)(cqr, callback_data);
1820                 if (block)
1821                         spin_unlock_bh(&block->queue_lock);
1822         }
1823 }
1824
1825 /*
1826  * Take a look at the first request on the ccw queue and check
1827  * if it reached its expire time. If so, terminate the IO.
1828  */
1829 static void __dasd_device_check_expire(struct dasd_device *device)
1830 {
1831         struct dasd_ccw_req *cqr;
1832
1833         if (list_empty(&device->ccw_queue))
1834                 return;
1835         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1836         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1837             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1838                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1839                         /*
1840                          * IO in safe offline processing should not
1841                          * run out of retries
1842                          */
1843                         cqr->retries++;
1844                 }
1845                 if (device->discipline->term_IO(cqr) != 0) {
1846                         /* Hmpf, try again in 5 sec */
1847                         dev_err(&device->cdev->dev,
1848                                 "cqr %p timed out (%lus) but cannot be "
1849                                 "ended, retrying in 5 s\n",
1850                                 cqr, (cqr->expires/HZ));
1851                         cqr->expires += 5*HZ;
1852                         dasd_device_set_timer(device, 5*HZ);
1853                 } else {
1854                         dev_err(&device->cdev->dev,
1855                                 "cqr %p timed out (%lus), %i retries "
1856                                 "remaining\n", cqr, (cqr->expires/HZ),
1857                                 cqr->retries);
1858                 }
1859         }
1860 }
1861
1862 /*
1863  * Take a look at the first request on the ccw queue and check
1864  * if it needs to be started.
1865  */
1866 static void __dasd_device_start_head(struct dasd_device *device)
1867 {
1868         struct dasd_ccw_req *cqr;
1869         int rc;
1870
1871         if (list_empty(&device->ccw_queue))
1872                 return;
1873         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1874         if (cqr->status != DASD_CQR_QUEUED)
1875                 return;
1876         /* when device is stopped, return request to previous layer
1877          * exception: only the disconnect or unresumed bits are set and the
1878          * cqr is a path verification request
1879          */
1880         if (device->stopped &&
1881             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1882               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1883                 cqr->intrc = -EAGAIN;
1884                 cqr->status = DASD_CQR_CLEARED;
1885                 dasd_schedule_device_bh(device);
1886                 return;
1887         }
1888
1889         rc = device->discipline->start_IO(cqr);
1890         if (rc == 0)
1891                 dasd_device_set_timer(device, cqr->expires);
1892         else if (rc == -EACCES) {
1893                 dasd_schedule_device_bh(device);
1894         } else
1895                 /* Hmpf, try again in 1/2 sec */
1896                 dasd_device_set_timer(device, 50);
1897 }
1898
1899 static void __dasd_device_check_path_events(struct dasd_device *device)
1900 {
1901         int rc;
1902
1903         if (device->path_data.tbvpm) {
1904                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1905                                         DASD_UNRESUMED_PM))
1906                         return;
1907                 rc = device->discipline->verify_path(
1908                         device, device->path_data.tbvpm);
1909                 if (rc)
1910                         dasd_device_set_timer(device, 50);
1911                 else
1912                         device->path_data.tbvpm = 0;
1913         }
1914 };
1915
1916 /*
1917  * Go through all request on the dasd_device request queue,
1918  * terminate them on the cdev if necessary, and return them to the
1919  * submitting layer via callback.
1920  * Note:
1921  * Make sure that all 'submitting layers' still exist when
1922  * this function is called!. In other words, when 'device' is a base
1923  * device then all block layer requests must have been removed before
1924  * via dasd_flush_block_queue.
1925  */
1926 int dasd_flush_device_queue(struct dasd_device *device)
1927 {
1928         struct dasd_ccw_req *cqr, *n;
1929         int rc;
1930         struct list_head flush_queue;
1931
1932         INIT_LIST_HEAD(&flush_queue);
1933         spin_lock_irq(get_ccwdev_lock(device->cdev));
1934         rc = 0;
1935         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1936                 /* Check status and move request to flush_queue */
1937                 switch (cqr->status) {
1938                 case DASD_CQR_IN_IO:
1939                         rc = device->discipline->term_IO(cqr);
1940                         if (rc) {
1941                                 /* unable to terminate requeust */
1942                                 dev_err(&device->cdev->dev,
1943                                         "Flushing the DASD request queue "
1944                                         "failed for request %p\n", cqr);
1945                                 /* stop flush processing */
1946                                 goto finished;
1947                         }
1948                         break;
1949                 case DASD_CQR_QUEUED:
1950                         cqr->stopclk = get_tod_clock();
1951                         cqr->status = DASD_CQR_CLEARED;
1952                         break;
1953                 default: /* no need to modify the others */
1954                         break;
1955                 }
1956                 list_move_tail(&cqr->devlist, &flush_queue);
1957         }
1958 finished:
1959         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1960         /*
1961          * After this point all requests must be in state CLEAR_PENDING,
1962          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1963          * one of the others.
1964          */
1965         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1966                 wait_event(dasd_flush_wq,
1967                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1968         /*
1969          * Now set each request back to TERMINATED, DONE or NEED_ERP
1970          * and call the callback function of flushed requests
1971          */
1972         __dasd_device_process_final_queue(device, &flush_queue);
1973         return rc;
1974 }
1975 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
1976
1977 /*
1978  * Acquire the device lock and process queues for the device.
1979  */
1980 static void dasd_device_tasklet(struct dasd_device *device)
1981 {
1982         struct list_head final_queue;
1983
1984         atomic_set (&device->tasklet_scheduled, 0);
1985         INIT_LIST_HEAD(&final_queue);
1986         spin_lock_irq(get_ccwdev_lock(device->cdev));
1987         /* Check expire time of first request on the ccw queue. */
1988         __dasd_device_check_expire(device);
1989         /* find final requests on ccw queue */
1990         __dasd_device_process_ccw_queue(device, &final_queue);
1991         __dasd_device_check_path_events(device);
1992         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1993         /* Now call the callback function of requests with final status */
1994         __dasd_device_process_final_queue(device, &final_queue);
1995         spin_lock_irq(get_ccwdev_lock(device->cdev));
1996         /* Now check if the head of the ccw queue needs to be started. */
1997         __dasd_device_start_head(device);
1998         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1999         if (waitqueue_active(&shutdown_waitq))
2000                 wake_up(&shutdown_waitq);
2001         dasd_put_device(device);
2002 }
2003
2004 /*
2005  * Schedules a call to dasd_tasklet over the device tasklet.
2006  */
2007 void dasd_schedule_device_bh(struct dasd_device *device)
2008 {
2009         /* Protect against rescheduling. */
2010         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2011                 return;
2012         dasd_get_device(device);
2013         tasklet_hi_schedule(&device->tasklet);
2014 }
2015 EXPORT_SYMBOL(dasd_schedule_device_bh);
2016
2017 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2018 {
2019         device->stopped |= bits;
2020 }
2021 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2022
2023 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2024 {
2025         device->stopped &= ~bits;
2026         if (!device->stopped)
2027                 wake_up(&generic_waitq);
2028 }
2029 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2030
2031 /*
2032  * Queue a request to the head of the device ccw_queue.
2033  * Start the I/O if possible.
2034  */
2035 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2036 {
2037         struct dasd_device *device;
2038         unsigned long flags;
2039
2040         device = cqr->startdev;
2041         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2042         cqr->status = DASD_CQR_QUEUED;
2043         list_add(&cqr->devlist, &device->ccw_queue);
2044         /* let the bh start the request to keep them in order */
2045         dasd_schedule_device_bh(device);
2046         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2047 }
2048 EXPORT_SYMBOL(dasd_add_request_head);
2049
2050 /*
2051  * Queue a request to the tail of the device ccw_queue.
2052  * Start the I/O if possible.
2053  */
2054 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2055 {
2056         struct dasd_device *device;
2057         unsigned long flags;
2058
2059         device = cqr->startdev;
2060         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2061         cqr->status = DASD_CQR_QUEUED;
2062         list_add_tail(&cqr->devlist, &device->ccw_queue);
2063         /* let the bh start the request to keep them in order */
2064         dasd_schedule_device_bh(device);
2065         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2066 }
2067 EXPORT_SYMBOL(dasd_add_request_tail);
2068
2069 /*
2070  * Wakeup helper for the 'sleep_on' functions.
2071  */
2072 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2073 {
2074         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2075         cqr->callback_data = DASD_SLEEPON_END_TAG;
2076         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2077         wake_up(&generic_waitq);
2078 }
2079 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2080
2081 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2082 {
2083         struct dasd_device *device;
2084         int rc;
2085
2086         device = cqr->startdev;
2087         spin_lock_irq(get_ccwdev_lock(device->cdev));
2088         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2089         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2090         return rc;
2091 }
2092
2093 /*
2094  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2095  */
2096 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2097 {
2098         struct dasd_device *device;
2099         dasd_erp_fn_t erp_fn;
2100
2101         if (cqr->status == DASD_CQR_FILLED)
2102                 return 0;
2103         device = cqr->startdev;
2104         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2105                 if (cqr->status == DASD_CQR_TERMINATED) {
2106                         device->discipline->handle_terminated_request(cqr);
2107                         return 1;
2108                 }
2109                 if (cqr->status == DASD_CQR_NEED_ERP) {
2110                         erp_fn = device->discipline->erp_action(cqr);
2111                         erp_fn(cqr);
2112                         return 1;
2113                 }
2114                 if (cqr->status == DASD_CQR_FAILED)
2115                         dasd_log_sense(cqr, &cqr->irb);
2116                 if (cqr->refers) {
2117                         __dasd_process_erp(device, cqr);
2118                         return 1;
2119                 }
2120         }
2121         return 0;
2122 }
2123
2124 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2125 {
2126         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2127                 if (cqr->refers) /* erp is not done yet */
2128                         return 1;
2129                 return ((cqr->status != DASD_CQR_DONE) &&
2130                         (cqr->status != DASD_CQR_FAILED));
2131         } else
2132                 return (cqr->status == DASD_CQR_FILLED);
2133 }
2134
2135 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2136 {
2137         struct dasd_device *device;
2138         int rc;
2139         struct list_head ccw_queue;
2140         struct dasd_ccw_req *cqr;
2141
2142         INIT_LIST_HEAD(&ccw_queue);
2143         maincqr->status = DASD_CQR_FILLED;
2144         device = maincqr->startdev;
2145         list_add(&maincqr->blocklist, &ccw_queue);
2146         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2147              cqr = list_first_entry(&ccw_queue,
2148                                     struct dasd_ccw_req, blocklist)) {
2149
2150                 if (__dasd_sleep_on_erp(cqr))
2151                         continue;
2152                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2153                         continue;
2154                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2155                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2156                         cqr->status = DASD_CQR_FAILED;
2157                         cqr->intrc = -EPERM;
2158                         continue;
2159                 }
2160                 /* Non-temporary stop condition will trigger fail fast */
2161                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2162                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2163                     (!dasd_eer_enabled(device))) {
2164                         cqr->status = DASD_CQR_FAILED;
2165                         cqr->intrc = -ENOLINK;
2166                         continue;
2167                 }
2168                 /* Don't try to start requests if device is stopped */
2169                 if (interruptible) {
2170                         rc = wait_event_interruptible(
2171                                 generic_waitq, !(device->stopped));
2172                         if (rc == -ERESTARTSYS) {
2173                                 cqr->status = DASD_CQR_FAILED;
2174                                 maincqr->intrc = rc;
2175                                 continue;
2176                         }
2177                 } else
2178                         wait_event(generic_waitq, !(device->stopped));
2179
2180                 if (!cqr->callback)
2181                         cqr->callback = dasd_wakeup_cb;
2182
2183                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2184                 dasd_add_request_tail(cqr);
2185                 if (interruptible) {
2186                         rc = wait_event_interruptible(
2187                                 generic_waitq, _wait_for_wakeup(cqr));
2188                         if (rc == -ERESTARTSYS) {
2189                                 dasd_cancel_req(cqr);
2190                                 /* wait (non-interruptible) for final status */
2191                                 wait_event(generic_waitq,
2192                                            _wait_for_wakeup(cqr));
2193                                 cqr->status = DASD_CQR_FAILED;
2194                                 maincqr->intrc = rc;
2195                                 continue;
2196                         }
2197                 } else
2198                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2199         }
2200
2201         maincqr->endclk = get_tod_clock();
2202         if ((maincqr->status != DASD_CQR_DONE) &&
2203             (maincqr->intrc != -ERESTARTSYS))
2204                 dasd_log_sense(maincqr, &maincqr->irb);
2205         if (maincqr->status == DASD_CQR_DONE)
2206                 rc = 0;
2207         else if (maincqr->intrc)
2208                 rc = maincqr->intrc;
2209         else
2210                 rc = -EIO;
2211         return rc;
2212 }
2213
2214 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2215 {
2216         struct dasd_ccw_req *cqr;
2217
2218         list_for_each_entry(cqr, ccw_queue, blocklist) {
2219                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2220                         return 0;
2221         }
2222
2223         return 1;
2224 }
2225
2226 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2227 {
2228         struct dasd_device *device;
2229         struct dasd_ccw_req *cqr, *n;
2230         int rc;
2231
2232 retry:
2233         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2234                 device = cqr->startdev;
2235                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2236                         continue;
2237
2238                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2239                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2240                         cqr->status = DASD_CQR_FAILED;
2241                         cqr->intrc = -EPERM;
2242                         continue;
2243                 }
2244                 /*Non-temporary stop condition will trigger fail fast*/
2245                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2246                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2247                     !dasd_eer_enabled(device)) {
2248                         cqr->status = DASD_CQR_FAILED;
2249                         cqr->intrc = -EAGAIN;
2250                         continue;
2251                 }
2252
2253                 /*Don't try to start requests if device is stopped*/
2254                 if (interruptible) {
2255                         rc = wait_event_interruptible(
2256                                 generic_waitq, !device->stopped);
2257                         if (rc == -ERESTARTSYS) {
2258                                 cqr->status = DASD_CQR_FAILED;
2259                                 cqr->intrc = rc;
2260                                 continue;
2261                         }
2262                 } else
2263                         wait_event(generic_waitq, !(device->stopped));
2264
2265                 if (!cqr->callback)
2266                         cqr->callback = dasd_wakeup_cb;
2267                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2268                 dasd_add_request_tail(cqr);
2269         }
2270
2271         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2272
2273         rc = 0;
2274         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2275                 /*
2276                  * for alias devices simplify error recovery and
2277                  * return to upper layer
2278                  * do not skip ERP requests
2279                  */
2280                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2281                     (cqr->status == DASD_CQR_TERMINATED ||
2282                      cqr->status == DASD_CQR_NEED_ERP))
2283                         return -EAGAIN;
2284
2285                 /* normal recovery for basedev IO */
2286                 if (__dasd_sleep_on_erp(cqr))
2287                         /* handle erp first */
2288                         goto retry;
2289         }
2290
2291         return 0;
2292 }
2293
2294 /*
2295  * Queue a request to the tail of the device ccw_queue and wait for
2296  * it's completion.
2297  */
2298 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2299 {
2300         return _dasd_sleep_on(cqr, 0);
2301 }
2302 EXPORT_SYMBOL(dasd_sleep_on);
2303
2304 /*
2305  * Start requests from a ccw_queue and wait for their completion.
2306  */
2307 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2308 {
2309         return _dasd_sleep_on_queue(ccw_queue, 0);
2310 }
2311 EXPORT_SYMBOL(dasd_sleep_on_queue);
2312
2313 /*
2314  * Queue a request to the tail of the device ccw_queue and wait
2315  * interruptible for it's completion.
2316  */
2317 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2318 {
2319         return _dasd_sleep_on(cqr, 1);
2320 }
2321 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2322
2323 /*
2324  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2325  * for eckd devices) the currently running request has to be terminated
2326  * and be put back to status queued, before the special request is added
2327  * to the head of the queue. Then the special request is waited on normally.
2328  */
2329 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2330 {
2331         struct dasd_ccw_req *cqr;
2332         int rc;
2333
2334         if (list_empty(&device->ccw_queue))
2335                 return 0;
2336         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2337         rc = device->discipline->term_IO(cqr);
2338         if (!rc)
2339                 /*
2340                  * CQR terminated because a more important request is pending.
2341                  * Undo decreasing of retry counter because this is
2342                  * not an error case.
2343                  */
2344                 cqr->retries++;
2345         return rc;
2346 }
2347
2348 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2349 {
2350         struct dasd_device *device;
2351         int rc;
2352
2353         device = cqr->startdev;
2354         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2355             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2356                 cqr->status = DASD_CQR_FAILED;
2357                 cqr->intrc = -EPERM;
2358                 return -EIO;
2359         }
2360         spin_lock_irq(get_ccwdev_lock(device->cdev));
2361         rc = _dasd_term_running_cqr(device);
2362         if (rc) {
2363                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2364                 return rc;
2365         }
2366         cqr->callback = dasd_wakeup_cb;
2367         cqr->callback_data = DASD_SLEEPON_START_TAG;
2368         cqr->status = DASD_CQR_QUEUED;
2369         /*
2370          * add new request as second
2371          * first the terminated cqr needs to be finished
2372          */
2373         list_add(&cqr->devlist, device->ccw_queue.next);
2374
2375         /* let the bh start the request to keep them in order */
2376         dasd_schedule_device_bh(device);
2377
2378         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2379
2380         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2381
2382         if (cqr->status == DASD_CQR_DONE)
2383                 rc = 0;
2384         else if (cqr->intrc)
2385                 rc = cqr->intrc;
2386         else
2387                 rc = -EIO;
2388
2389         /* kick tasklets */
2390         dasd_schedule_device_bh(device);
2391         if (device->block)
2392                 dasd_schedule_block_bh(device->block);
2393
2394         return rc;
2395 }
2396 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2397
2398 /*
2399  * Cancels a request that was started with dasd_sleep_on_req.
2400  * This is useful to timeout requests. The request will be
2401  * terminated if it is currently in i/o.
2402  * Returns 0 if request termination was successful
2403  *         negative error code if termination failed
2404  * Cancellation of a request is an asynchronous operation! The calling
2405  * function has to wait until the request is properly returned via callback.
2406  */
2407 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2408 {
2409         struct dasd_device *device = cqr->startdev;
2410         unsigned long flags;
2411         int rc;
2412
2413         rc = 0;
2414         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2415         switch (cqr->status) {
2416         case DASD_CQR_QUEUED:
2417                 /* request was not started - just set to cleared */
2418                 cqr->status = DASD_CQR_CLEARED;
2419                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2420                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2421                 break;
2422         case DASD_CQR_IN_IO:
2423                 /* request in IO - terminate IO and release again */
2424                 rc = device->discipline->term_IO(cqr);
2425                 if (rc) {
2426                         dev_err(&device->cdev->dev,
2427                                 "Cancelling request %p failed with rc=%d\n",
2428                                 cqr, rc);
2429                 } else {
2430                         cqr->stopclk = get_tod_clock();
2431                 }
2432                 break;
2433         default: /* already finished or clear pending - do nothing */
2434                 break;
2435         }
2436         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2437         dasd_schedule_device_bh(device);
2438         return rc;
2439 }
2440 EXPORT_SYMBOL(dasd_cancel_req);
2441
2442 /*
2443  * SECTION: Operations of the dasd_block layer.
2444  */
2445
2446 /*
2447  * Timeout function for dasd_block. This is used when the block layer
2448  * is waiting for something that may not come reliably, (e.g. a state
2449  * change interrupt)
2450  */
2451 static void dasd_block_timeout(unsigned long ptr)
2452 {
2453         unsigned long flags;
2454         struct dasd_block *block;
2455
2456         block = (struct dasd_block *) ptr;
2457         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2458         /* re-activate request queue */
2459         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2460         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2461         dasd_schedule_block_bh(block);
2462 }
2463
2464 /*
2465  * Setup timeout for a dasd_block in jiffies.
2466  */
2467 void dasd_block_set_timer(struct dasd_block *block, int expires)
2468 {
2469         if (expires == 0)
2470                 del_timer(&block->timer);
2471         else
2472                 mod_timer(&block->timer, jiffies + expires);
2473 }
2474 EXPORT_SYMBOL(dasd_block_set_timer);
2475
2476 /*
2477  * Clear timeout for a dasd_block.
2478  */
2479 void dasd_block_clear_timer(struct dasd_block *block)
2480 {
2481         del_timer(&block->timer);
2482 }
2483 EXPORT_SYMBOL(dasd_block_clear_timer);
2484
2485 /*
2486  * Process finished error recovery ccw.
2487  */
2488 static void __dasd_process_erp(struct dasd_device *device,
2489                                struct dasd_ccw_req *cqr)
2490 {
2491         dasd_erp_fn_t erp_fn;
2492
2493         if (cqr->status == DASD_CQR_DONE)
2494                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2495         else
2496                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2497         erp_fn = device->discipline->erp_postaction(cqr);
2498         erp_fn(cqr);
2499 }
2500
2501 /*
2502  * Fetch requests from the block device queue.
2503  */
2504 static void __dasd_process_request_queue(struct dasd_block *block)
2505 {
2506         struct request_queue *queue;
2507         struct request *req;
2508         struct dasd_ccw_req *cqr;
2509         struct dasd_device *basedev;
2510         unsigned long flags;
2511         queue = block->request_queue;
2512         basedev = block->base;
2513         /* No queue ? Then there is nothing to do. */
2514         if (queue == NULL)
2515                 return;
2516
2517         /*
2518          * We requeue request from the block device queue to the ccw
2519          * queue only in two states. In state DASD_STATE_READY the
2520          * partition detection is done and we need to requeue requests
2521          * for that. State DASD_STATE_ONLINE is normal block device
2522          * operation.
2523          */
2524         if (basedev->state < DASD_STATE_READY) {
2525                 while ((req = blk_fetch_request(block->request_queue)))
2526                         __blk_end_request_all(req, -EIO);
2527                 return;
2528         }
2529         /* Now we try to fetch requests from the request queue */
2530         while ((req = blk_peek_request(queue))) {
2531                 if (basedev->features & DASD_FEATURE_READONLY &&
2532                     rq_data_dir(req) == WRITE) {
2533                         DBF_DEV_EVENT(DBF_ERR, basedev,
2534                                       "Rejecting write request %p",
2535                                       req);
2536                         blk_start_request(req);
2537                         __blk_end_request_all(req, -EIO);
2538                         continue;
2539                 }
2540                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2541                     (basedev->features & DASD_FEATURE_FAILFAST ||
2542                      blk_noretry_request(req))) {
2543                         DBF_DEV_EVENT(DBF_ERR, basedev,
2544                                       "Rejecting failfast request %p",
2545                                       req);
2546                         blk_start_request(req);
2547                         __blk_end_request_all(req, -ETIMEDOUT);
2548                         continue;
2549                 }
2550                 cqr = basedev->discipline->build_cp(basedev, block, req);
2551                 if (IS_ERR(cqr)) {
2552                         if (PTR_ERR(cqr) == -EBUSY)
2553                                 break;  /* normal end condition */
2554                         if (PTR_ERR(cqr) == -ENOMEM)
2555                                 break;  /* terminate request queue loop */
2556                         if (PTR_ERR(cqr) == -EAGAIN) {
2557                                 /*
2558                                  * The current request cannot be build right
2559                                  * now, we have to try later. If this request
2560                                  * is the head-of-queue we stop the device
2561                                  * for 1/2 second.
2562                                  */
2563                                 if (!list_empty(&block->ccw_queue))
2564                                         break;
2565                                 spin_lock_irqsave(
2566                                         get_ccwdev_lock(basedev->cdev), flags);
2567                                 dasd_device_set_stop_bits(basedev,
2568                                                           DASD_STOPPED_PENDING);
2569                                 spin_unlock_irqrestore(
2570                                         get_ccwdev_lock(basedev->cdev), flags);
2571                                 dasd_block_set_timer(block, HZ/2);
2572                                 break;
2573                         }
2574                         DBF_DEV_EVENT(DBF_ERR, basedev,
2575                                       "CCW creation failed (rc=%ld) "
2576                                       "on request %p",
2577                                       PTR_ERR(cqr), req);
2578                         blk_start_request(req);
2579                         __blk_end_request_all(req, -EIO);
2580                         continue;
2581                 }
2582                 /*
2583                  *  Note: callback is set to dasd_return_cqr_cb in
2584                  * __dasd_block_start_head to cover erp requests as well
2585                  */
2586                 cqr->callback_data = (void *) req;
2587                 cqr->status = DASD_CQR_FILLED;
2588                 req->completion_data = cqr;
2589                 blk_start_request(req);
2590                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2591                 INIT_LIST_HEAD(&cqr->devlist);
2592                 dasd_profile_start(block, cqr, req);
2593         }
2594 }
2595
2596 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2597 {
2598         struct request *req;
2599         int status;
2600         int error = 0;
2601
2602         req = (struct request *) cqr->callback_data;
2603         dasd_profile_end(cqr->block, cqr, req);
2604         status = cqr->block->base->discipline->free_cp(cqr, req);
2605         if (status < 0)
2606                 error = status;
2607         else if (status == 0) {
2608                 if (cqr->intrc == -EPERM)
2609                         error = -EBADE;
2610                 else if (cqr->intrc == -ENOLINK ||
2611                          cqr->intrc == -ETIMEDOUT)
2612                         error = cqr->intrc;
2613                 else
2614                         error = -EIO;
2615         }
2616         __blk_end_request_all(req, error);
2617 }
2618
2619 /*
2620  * Process ccw request queue.
2621  */
2622 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2623                                            struct list_head *final_queue)
2624 {
2625         struct list_head *l, *n;
2626         struct dasd_ccw_req *cqr;
2627         dasd_erp_fn_t erp_fn;
2628         unsigned long flags;
2629         struct dasd_device *base = block->base;
2630
2631 restart:
2632         /* Process request with final status. */
2633         list_for_each_safe(l, n, &block->ccw_queue) {
2634                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2635                 if (cqr->status != DASD_CQR_DONE &&
2636                     cqr->status != DASD_CQR_FAILED &&
2637                     cqr->status != DASD_CQR_NEED_ERP &&
2638                     cqr->status != DASD_CQR_TERMINATED)
2639                         continue;
2640
2641                 if (cqr->status == DASD_CQR_TERMINATED) {
2642                         base->discipline->handle_terminated_request(cqr);
2643                         goto restart;
2644                 }
2645
2646                 /*  Process requests that may be recovered */
2647                 if (cqr->status == DASD_CQR_NEED_ERP) {
2648                         erp_fn = base->discipline->erp_action(cqr);
2649                         if (IS_ERR(erp_fn(cqr)))
2650                                 continue;
2651                         goto restart;
2652                 }
2653
2654                 /* log sense for fatal error */
2655                 if (cqr->status == DASD_CQR_FAILED) {
2656                         dasd_log_sense(cqr, &cqr->irb);
2657                 }
2658
2659                 /* First of all call extended error reporting. */
2660                 if (dasd_eer_enabled(base) &&
2661                     cqr->status == DASD_CQR_FAILED) {
2662                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2663
2664                         /* restart request  */
2665                         cqr->status = DASD_CQR_FILLED;
2666                         cqr->retries = 255;
2667                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2668                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2669                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2670                                                flags);
2671                         goto restart;
2672                 }
2673
2674                 /* Process finished ERP request. */
2675                 if (cqr->refers) {
2676                         __dasd_process_erp(base, cqr);
2677                         goto restart;
2678                 }
2679
2680                 /* Rechain finished requests to final queue */
2681                 cqr->endclk = get_tod_clock();
2682                 list_move_tail(&cqr->blocklist, final_queue);
2683         }
2684 }
2685
2686 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2687 {
2688         dasd_schedule_block_bh(cqr->block);
2689 }
2690
2691 static void __dasd_block_start_head(struct dasd_block *block)
2692 {
2693         struct dasd_ccw_req *cqr;
2694
2695         if (list_empty(&block->ccw_queue))
2696                 return;
2697         /* We allways begin with the first requests on the queue, as some
2698          * of previously started requests have to be enqueued on a
2699          * dasd_device again for error recovery.
2700          */
2701         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2702                 if (cqr->status != DASD_CQR_FILLED)
2703                         continue;
2704                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2705                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2706                         cqr->status = DASD_CQR_FAILED;
2707                         cqr->intrc = -EPERM;
2708                         dasd_schedule_block_bh(block);
2709                         continue;
2710                 }
2711                 /* Non-temporary stop condition will trigger fail fast */
2712                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2713                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2714                     (!dasd_eer_enabled(block->base))) {
2715                         cqr->status = DASD_CQR_FAILED;
2716                         cqr->intrc = -ENOLINK;
2717                         dasd_schedule_block_bh(block);
2718                         continue;
2719                 }
2720                 /* Don't try to start requests if device is stopped */
2721                 if (block->base->stopped)
2722                         return;
2723
2724                 /* just a fail safe check, should not happen */
2725                 if (!cqr->startdev)
2726                         cqr->startdev = block->base;
2727
2728                 /* make sure that the requests we submit find their way back */
2729                 cqr->callback = dasd_return_cqr_cb;
2730
2731                 dasd_add_request_tail(cqr);
2732         }
2733 }
2734
2735 /*
2736  * Central dasd_block layer routine. Takes requests from the generic
2737  * block layer request queue, creates ccw requests, enqueues them on
2738  * a dasd_device and processes ccw requests that have been returned.
2739  */
2740 static void dasd_block_tasklet(struct dasd_block *block)
2741 {
2742         struct list_head final_queue;
2743         struct list_head *l, *n;
2744         struct dasd_ccw_req *cqr;
2745
2746         atomic_set(&block->tasklet_scheduled, 0);
2747         INIT_LIST_HEAD(&final_queue);
2748         spin_lock(&block->queue_lock);
2749         /* Finish off requests on ccw queue */
2750         __dasd_process_block_ccw_queue(block, &final_queue);
2751         spin_unlock(&block->queue_lock);
2752         /* Now call the callback function of requests with final status */
2753         spin_lock_irq(&block->request_queue_lock);
2754         list_for_each_safe(l, n, &final_queue) {
2755                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2756                 list_del_init(&cqr->blocklist);
2757                 __dasd_cleanup_cqr(cqr);
2758         }
2759         spin_lock(&block->queue_lock);
2760         /* Get new request from the block device request queue */
2761         __dasd_process_request_queue(block);
2762         /* Now check if the head of the ccw queue needs to be started. */
2763         __dasd_block_start_head(block);
2764         spin_unlock(&block->queue_lock);
2765         spin_unlock_irq(&block->request_queue_lock);
2766         if (waitqueue_active(&shutdown_waitq))
2767                 wake_up(&shutdown_waitq);
2768         dasd_put_device(block->base);
2769 }
2770
2771 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2772 {
2773         wake_up(&dasd_flush_wq);
2774 }
2775
2776 /*
2777  * Requeue a request back to the block request queue
2778  * only works for block requests
2779  */
2780 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2781 {
2782         struct dasd_block *block = cqr->block;
2783         struct request *req;
2784         unsigned long flags;
2785
2786         if (!block)
2787                 return -EINVAL;
2788         spin_lock_irqsave(&block->queue_lock, flags);
2789         req = (struct request *) cqr->callback_data;
2790         blk_requeue_request(block->request_queue, req);
2791         spin_unlock_irqrestore(&block->queue_lock, flags);
2792
2793         return 0;
2794 }
2795
2796 /*
2797  * Go through all request on the dasd_block request queue, cancel them
2798  * on the respective dasd_device, and return them to the generic
2799  * block layer.
2800  */
2801 static int dasd_flush_block_queue(struct dasd_block *block)
2802 {
2803         struct dasd_ccw_req *cqr, *n;
2804         int rc, i;
2805         struct list_head flush_queue;
2806
2807         INIT_LIST_HEAD(&flush_queue);
2808         spin_lock_bh(&block->queue_lock);
2809         rc = 0;
2810 restart:
2811         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2812                 /* if this request currently owned by a dasd_device cancel it */
2813                 if (cqr->status >= DASD_CQR_QUEUED)
2814                         rc = dasd_cancel_req(cqr);
2815                 if (rc < 0)
2816                         break;
2817                 /* Rechain request (including erp chain) so it won't be
2818                  * touched by the dasd_block_tasklet anymore.
2819                  * Replace the callback so we notice when the request
2820                  * is returned from the dasd_device layer.
2821                  */
2822                 cqr->callback = _dasd_wake_block_flush_cb;
2823                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2824                         list_move_tail(&cqr->blocklist, &flush_queue);
2825                 if (i > 1)
2826                         /* moved more than one request - need to restart */
2827                         goto restart;
2828         }
2829         spin_unlock_bh(&block->queue_lock);
2830         /* Now call the callback function of flushed requests */
2831 restart_cb:
2832         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2833                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2834                 /* Process finished ERP request. */
2835                 if (cqr->refers) {
2836                         spin_lock_bh(&block->queue_lock);
2837                         __dasd_process_erp(block->base, cqr);
2838                         spin_unlock_bh(&block->queue_lock);
2839                         /* restart list_for_xx loop since dasd_process_erp
2840                          * might remove multiple elements */
2841                         goto restart_cb;
2842                 }
2843                 /* call the callback function */
2844                 spin_lock_irq(&block->request_queue_lock);
2845                 cqr->endclk = get_tod_clock();
2846                 list_del_init(&cqr->blocklist);
2847                 __dasd_cleanup_cqr(cqr);
2848                 spin_unlock_irq(&block->request_queue_lock);
2849         }
2850         return rc;
2851 }
2852
2853 /*
2854  * Schedules a call to dasd_tasklet over the device tasklet.
2855  */
2856 void dasd_schedule_block_bh(struct dasd_block *block)
2857 {
2858         /* Protect against rescheduling. */
2859         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2860                 return;
2861         /* life cycle of block is bound to it's base device */
2862         dasd_get_device(block->base);
2863         tasklet_hi_schedule(&block->tasklet);
2864 }
2865 EXPORT_SYMBOL(dasd_schedule_block_bh);
2866
2867
2868 /*
2869  * SECTION: external block device operations
2870  * (request queue handling, open, release, etc.)
2871  */
2872
2873 /*
2874  * Dasd request queue function. Called from ll_rw_blk.c
2875  */
2876 static void do_dasd_request(struct request_queue *queue)
2877 {
2878         struct dasd_block *block;
2879
2880         block = queue->queuedata;
2881         spin_lock(&block->queue_lock);
2882         /* Get new request from the block device request queue */
2883         __dasd_process_request_queue(block);
2884         /* Now check if the head of the ccw queue needs to be started. */
2885         __dasd_block_start_head(block);
2886         spin_unlock(&block->queue_lock);
2887 }
2888
2889 /*
2890  * Block timeout callback, called from the block layer
2891  *
2892  * request_queue lock is held on entry.
2893  *
2894  * Return values:
2895  * BLK_EH_RESET_TIMER if the request should be left running
2896  * BLK_EH_NOT_HANDLED if the request is handled or terminated
2897  *                    by the driver.
2898  */
2899 enum blk_eh_timer_return dasd_times_out(struct request *req)
2900 {
2901         struct dasd_ccw_req *cqr = req->completion_data;
2902         struct dasd_block *block = req->q->queuedata;
2903         struct dasd_device *device;
2904         int rc = 0;
2905
2906         if (!cqr)
2907                 return BLK_EH_NOT_HANDLED;
2908
2909         device = cqr->startdev ? cqr->startdev : block->base;
2910         if (!device->blk_timeout)
2911                 return BLK_EH_RESET_TIMER;
2912         DBF_DEV_EVENT(DBF_WARNING, device,
2913                       " dasd_times_out cqr %p status %x",
2914                       cqr, cqr->status);
2915
2916         spin_lock(&block->queue_lock);
2917         spin_lock(get_ccwdev_lock(device->cdev));
2918         cqr->retries = -1;
2919         cqr->intrc = -ETIMEDOUT;
2920         if (cqr->status >= DASD_CQR_QUEUED) {
2921                 spin_unlock(get_ccwdev_lock(device->cdev));
2922                 rc = dasd_cancel_req(cqr);
2923         } else if (cqr->status == DASD_CQR_FILLED ||
2924                    cqr->status == DASD_CQR_NEED_ERP) {
2925                 cqr->status = DASD_CQR_TERMINATED;
2926                 spin_unlock(get_ccwdev_lock(device->cdev));
2927         } else if (cqr->status == DASD_CQR_IN_ERP) {
2928                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
2929
2930                 list_for_each_entry_safe(searchcqr, nextcqr,
2931                                          &block->ccw_queue, blocklist) {
2932                         tmpcqr = searchcqr;
2933                         while (tmpcqr->refers)
2934                                 tmpcqr = tmpcqr->refers;
2935                         if (tmpcqr != cqr)
2936                                 continue;
2937                         /* searchcqr is an ERP request for cqr */
2938                         searchcqr->retries = -1;
2939                         searchcqr->intrc = -ETIMEDOUT;
2940                         if (searchcqr->status >= DASD_CQR_QUEUED) {
2941                                 spin_unlock(get_ccwdev_lock(device->cdev));
2942                                 rc = dasd_cancel_req(searchcqr);
2943                                 spin_lock(get_ccwdev_lock(device->cdev));
2944                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
2945                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
2946                                 searchcqr->status = DASD_CQR_TERMINATED;
2947                                 rc = 0;
2948                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
2949                                 /*
2950                                  * Shouldn't happen; most recent ERP
2951                                  * request is at the front of queue
2952                                  */
2953                                 continue;
2954                         }
2955                         break;
2956                 }
2957                 spin_unlock(get_ccwdev_lock(device->cdev));
2958         }
2959         dasd_schedule_block_bh(block);
2960         spin_unlock(&block->queue_lock);
2961
2962         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
2963 }
2964
2965 /*
2966  * Allocate and initialize request queue and default I/O scheduler.
2967  */
2968 static int dasd_alloc_queue(struct dasd_block *block)
2969 {
2970         int rc;
2971
2972         block->request_queue = blk_init_queue(do_dasd_request,
2973                                                &block->request_queue_lock);
2974         if (block->request_queue == NULL)
2975                 return -ENOMEM;
2976
2977         block->request_queue->queuedata = block;
2978
2979         elevator_exit(block->request_queue->elevator);
2980         block->request_queue->elevator = NULL;
2981         mutex_lock(&block->request_queue->sysfs_lock);
2982         rc = elevator_init(block->request_queue, "deadline");
2983         if (rc)
2984                 blk_cleanup_queue(block->request_queue);
2985         mutex_unlock(&block->request_queue->sysfs_lock);
2986         return rc;
2987 }
2988
2989 /*
2990  * Allocate and initialize request queue.
2991  */
2992 static void dasd_setup_queue(struct dasd_block *block)
2993 {
2994         int max;
2995
2996         if (block->base->features & DASD_FEATURE_USERAW) {
2997                 /*
2998                  * the max_blocks value for raw_track access is 256
2999                  * it is higher than the native ECKD value because we
3000                  * only need one ccw per track
3001                  * so the max_hw_sectors are
3002                  * 2048 x 512B = 1024kB = 16 tracks
3003                  */
3004                 max = 2048;
3005         } else {
3006                 max = block->base->discipline->max_blocks << block->s2b_shift;
3007         }
3008         blk_queue_logical_block_size(block->request_queue,
3009                                      block->bp_block);
3010         blk_queue_max_hw_sectors(block->request_queue, max);
3011         blk_queue_max_segments(block->request_queue, -1L);
3012         /* with page sized segments we can translate each segement into
3013          * one idaw/tidaw
3014          */
3015         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3016         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3017 }
3018
3019 /*
3020  * Deactivate and free request queue.
3021  */
3022 static void dasd_free_queue(struct dasd_block *block)
3023 {
3024         if (block->request_queue) {
3025                 blk_cleanup_queue(block->request_queue);
3026                 block->request_queue = NULL;
3027         }
3028 }
3029
3030 /*
3031  * Flush request on the request queue.
3032  */
3033 static void dasd_flush_request_queue(struct dasd_block *block)
3034 {
3035         struct request *req;
3036
3037         if (!block->request_queue)
3038                 return;
3039
3040         spin_lock_irq(&block->request_queue_lock);
3041         while ((req = blk_fetch_request(block->request_queue)))
3042                 __blk_end_request_all(req, -EIO);
3043         spin_unlock_irq(&block->request_queue_lock);
3044 }
3045
3046 static int dasd_open(struct block_device *bdev, fmode_t mode)
3047 {
3048         struct dasd_device *base;
3049         int rc;
3050
3051         base = dasd_device_from_gendisk(bdev->bd_disk);
3052         if (!base)
3053                 return -ENODEV;
3054
3055         atomic_inc(&base->block->open_count);
3056         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3057                 rc = -ENODEV;
3058                 goto unlock;
3059         }
3060
3061         if (!try_module_get(base->discipline->owner)) {
3062                 rc = -EINVAL;
3063                 goto unlock;
3064         }
3065
3066         if (dasd_probeonly) {
3067                 dev_info(&base->cdev->dev,
3068                          "Accessing the DASD failed because it is in "
3069                          "probeonly mode\n");
3070                 rc = -EPERM;
3071                 goto out;
3072         }
3073
3074         if (base->state <= DASD_STATE_BASIC) {
3075                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3076                               " Cannot open unrecognized device");
3077                 rc = -ENODEV;
3078                 goto out;
3079         }
3080
3081         if ((mode & FMODE_WRITE) &&
3082             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3083              (base->features & DASD_FEATURE_READONLY))) {
3084                 rc = -EROFS;
3085                 goto out;
3086         }
3087
3088         dasd_put_device(base);
3089         return 0;
3090
3091 out:
3092         module_put(base->discipline->owner);
3093 unlock:
3094         atomic_dec(&base->block->open_count);
3095         dasd_put_device(base);
3096         return rc;
3097 }
3098
3099 static void dasd_release(struct gendisk *disk, fmode_t mode)
3100 {
3101         struct dasd_device *base = dasd_device_from_gendisk(disk);
3102         if (base) {
3103                 atomic_dec(&base->block->open_count);
3104                 module_put(base->discipline->owner);
3105                 dasd_put_device(base);
3106         }
3107 }
3108
3109 /*
3110  * Return disk geometry.
3111  */
3112 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3113 {
3114         struct dasd_device *base;
3115
3116         base = dasd_device_from_gendisk(bdev->bd_disk);
3117         if (!base)
3118                 return -ENODEV;
3119
3120         if (!base->discipline ||
3121             !base->discipline->fill_geometry) {
3122                 dasd_put_device(base);
3123                 return -EINVAL;
3124         }
3125         base->discipline->fill_geometry(base->block, geo);
3126         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3127         dasd_put_device(base);
3128         return 0;
3129 }
3130
3131 const struct block_device_operations
3132 dasd_device_operations = {
3133         .owner          = THIS_MODULE,
3134         .open           = dasd_open,
3135         .release        = dasd_release,
3136         .ioctl          = dasd_ioctl,
3137         .compat_ioctl   = dasd_ioctl,
3138         .getgeo         = dasd_getgeo,
3139 };
3140
3141 /*******************************************************************************
3142  * end of block device operations
3143  */
3144
3145 static void
3146 dasd_exit(void)
3147 {
3148 #ifdef CONFIG_PROC_FS
3149         dasd_proc_exit();
3150 #endif
3151         dasd_eer_exit();
3152         if (dasd_page_cache != NULL) {
3153                 kmem_cache_destroy(dasd_page_cache);
3154                 dasd_page_cache = NULL;
3155         }
3156         dasd_gendisk_exit();
3157         dasd_devmap_exit();
3158         if (dasd_debug_area != NULL) {
3159                 debug_unregister(dasd_debug_area);
3160                 dasd_debug_area = NULL;
3161         }
3162         dasd_statistics_removeroot();
3163 }
3164
3165 /*
3166  * SECTION: common functions for ccw_driver use
3167  */
3168
3169 /*
3170  * Is the device read-only?
3171  * Note that this function does not report the setting of the
3172  * readonly device attribute, but how it is configured in z/VM.
3173  */
3174 int dasd_device_is_ro(struct dasd_device *device)
3175 {
3176         struct ccw_dev_id dev_id;
3177         struct diag210 diag_data;
3178         int rc;
3179
3180         if (!MACHINE_IS_VM)
3181                 return 0;
3182         ccw_device_get_id(device->cdev, &dev_id);
3183         memset(&diag_data, 0, sizeof(diag_data));
3184         diag_data.vrdcdvno = dev_id.devno;
3185         diag_data.vrdclen = sizeof(diag_data);
3186         rc = diag210(&diag_data);
3187         if (rc == 0 || rc == 2) {
3188                 return diag_data.vrdcvfla & 0x80;
3189         } else {
3190                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3191                           dev_id.devno, rc);
3192                 return 0;
3193         }
3194 }
3195 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3196
3197 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3198 {
3199         struct ccw_device *cdev = data;
3200         int ret;
3201
3202         ret = ccw_device_set_online(cdev);
3203         if (ret)
3204                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3205                         dev_name(&cdev->dev), ret);
3206 }
3207
3208 /*
3209  * Initial attempt at a probe function. this can be simplified once
3210  * the other detection code is gone.
3211  */
3212 int dasd_generic_probe(struct ccw_device *cdev,
3213                        struct dasd_discipline *discipline)
3214 {
3215         int ret;
3216
3217         ret = dasd_add_sysfs_files(cdev);
3218         if (ret) {
3219                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3220                                 "dasd_generic_probe: could not add "
3221                                 "sysfs entries");
3222                 return ret;
3223         }
3224         cdev->handler = &dasd_int_handler;
3225
3226         /*
3227          * Automatically online either all dasd devices (dasd_autodetect)
3228          * or all devices specified with dasd= parameters during
3229          * initial probe.
3230          */
3231         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3232             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3233                 async_schedule(dasd_generic_auto_online, cdev);
3234         return 0;
3235 }
3236 EXPORT_SYMBOL_GPL(dasd_generic_probe);
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 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3280
3281 /*
3282  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3283  * the device is detected for the first time and is supposed to be used
3284  * or the user has started activation through sysfs.
3285  */
3286 int dasd_generic_set_online(struct ccw_device *cdev,
3287                             struct dasd_discipline *base_discipline)
3288 {
3289         struct dasd_discipline *discipline;
3290         struct dasd_device *device;
3291         int rc;
3292
3293         /* first online clears initial online feature flag */
3294         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3295         device = dasd_create_device(cdev);
3296         if (IS_ERR(device))
3297                 return PTR_ERR(device);
3298
3299         discipline = base_discipline;
3300         if (device->features & DASD_FEATURE_USEDIAG) {
3301                 if (!dasd_diag_discipline_pointer) {
3302                         pr_warn("%s Setting the DASD online failed because 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_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3325                         dev_name(&cdev->dev), discipline->name, rc);
3326                 module_put(discipline->owner);
3327                 module_put(base_discipline->owner);
3328                 dasd_delete_device(device);
3329                 return rc;
3330         }
3331
3332         dasd_set_target_state(device, DASD_STATE_ONLINE);
3333         if (device->state <= DASD_STATE_KNOWN) {
3334                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3335                         dev_name(&cdev->dev));
3336                 rc = -ENODEV;
3337                 dasd_set_target_state(device, DASD_STATE_NEW);
3338                 if (device->block)
3339                         dasd_free_block(device->block);
3340                 dasd_delete_device(device);
3341         } else
3342                 pr_debug("dasd_generic device %s found\n",
3343                                 dev_name(&cdev->dev));
3344
3345         wait_event(dasd_init_waitq, _wait_for_device(device));
3346
3347         dasd_put_device(device);
3348         return rc;
3349 }
3350 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
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_warn("%s: The DASD cannot be set offline with open count %i\n",
3375                                         dev_name(&cdev->dev), open_count);
3376                         else
3377                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3378                                         dev_name(&cdev->dev));
3379                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3380                         dasd_put_device(device);
3381                         return -EBUSY;
3382                 }
3383         }
3384
3385         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3386                 /*
3387                  * safe offline already running
3388                  * could only be called by normal offline so safe_offline flag
3389                  * needs to be removed to run normal offline and kill all I/O
3390                  */
3391                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3392                         /* Already doing normal offline processing */
3393                         dasd_put_device(device);
3394                         return -EBUSY;
3395                 } else
3396                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3397
3398         } else
3399                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3400                         /* Already doing offline processing */
3401                         dasd_put_device(device);
3402                         return -EBUSY;
3403                 }
3404
3405         /*
3406          * if safe_offline called set safe_offline_running flag and
3407          * clear safe_offline so that a call to normal offline
3408          * can overrun safe_offline processing
3409          */
3410         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3411             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3412                 /*
3413                  * If we want to set the device safe offline all IO operations
3414                  * should be finished before continuing the offline process
3415                  * so sync bdev first and then wait for our queues to become
3416                  * empty
3417                  */
3418                 /* sync blockdev and partitions */
3419                 rc = fsync_bdev(device->block->bdev);
3420                 if (rc != 0)
3421                         goto interrupted;
3422
3423                 /* schedule device tasklet and wait for completion */
3424                 dasd_schedule_device_bh(device);
3425                 rc = wait_event_interruptible(shutdown_waitq,
3426                                               _wait_for_empty_queues(device));
3427                 if (rc != 0)
3428                         goto interrupted;
3429         }
3430
3431         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3432         dasd_set_target_state(device, DASD_STATE_NEW);
3433         /* dasd_delete_device destroys the device reference. */
3434         block = device->block;
3435         dasd_delete_device(device);
3436         /*
3437          * life cycle of block is bound to device, so delete it after
3438          * device was safely removed
3439          */
3440         if (block)
3441                 dasd_free_block(block);
3442         return 0;
3443
3444 interrupted:
3445         /* interrupted by signal */
3446         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3447         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3448         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3449         dasd_put_device(device);
3450         return rc;
3451 }
3452 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3453
3454 int dasd_generic_last_path_gone(struct dasd_device *device)
3455 {
3456         struct dasd_ccw_req *cqr;
3457
3458         dev_warn(&device->cdev->dev, "No operational channel path is left "
3459                  "for the device\n");
3460         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3461         /* First of all call extended error reporting. */
3462         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3463
3464         if (device->state < DASD_STATE_BASIC)
3465                 return 0;
3466         /* Device is active. We want to keep it. */
3467         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3468                 if ((cqr->status == DASD_CQR_IN_IO) ||
3469                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3470                         cqr->status = DASD_CQR_QUEUED;
3471                         cqr->retries++;
3472                 }
3473         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3474         dasd_device_clear_timer(device);
3475         dasd_schedule_device_bh(device);
3476         return 1;
3477 }
3478 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3479
3480 int dasd_generic_path_operational(struct dasd_device *device)
3481 {
3482         dev_info(&device->cdev->dev, "A channel path to the device has become "
3483                  "operational\n");
3484         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3485         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3486         if (device->stopped & DASD_UNRESUMED_PM) {
3487                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3488                 dasd_restore_device(device);
3489                 return 1;
3490         }
3491         dasd_schedule_device_bh(device);
3492         if (device->block)
3493                 dasd_schedule_block_bh(device->block);
3494
3495         if (!device->stopped)
3496                 wake_up(&generic_waitq);
3497
3498         return 1;
3499 }
3500 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3501
3502 int dasd_generic_notify(struct ccw_device *cdev, int event)
3503 {
3504         struct dasd_device *device;
3505         int ret;
3506
3507         device = dasd_device_from_cdev_locked(cdev);
3508         if (IS_ERR(device))
3509                 return 0;
3510         ret = 0;
3511         switch (event) {
3512         case CIO_GONE:
3513         case CIO_BOXED:
3514         case CIO_NO_PATH:
3515                 device->path_data.opm = 0;
3516                 device->path_data.ppm = 0;
3517                 device->path_data.npm = 0;
3518                 ret = dasd_generic_last_path_gone(device);
3519                 break;
3520         case CIO_OPER:
3521                 ret = 1;
3522                 if (device->path_data.opm)
3523                         ret = dasd_generic_path_operational(device);
3524                 break;
3525         }
3526         dasd_put_device(device);
3527         return ret;
3528 }
3529 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3530
3531 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3532 {
3533         int chp;
3534         __u8 oldopm, eventlpm;
3535         struct dasd_device *device;
3536
3537         device = dasd_device_from_cdev_locked(cdev);
3538         if (IS_ERR(device))
3539                 return;
3540         for (chp = 0; chp < 8; chp++) {
3541                 eventlpm = 0x80 >> chp;
3542                 if (path_event[chp] & PE_PATH_GONE) {
3543                         oldopm = device->path_data.opm;
3544                         device->path_data.opm &= ~eventlpm;
3545                         device->path_data.ppm &= ~eventlpm;
3546                         device->path_data.npm &= ~eventlpm;
3547                         if (oldopm && !device->path_data.opm) {
3548                                 dev_warn(&device->cdev->dev,
3549                                          "No verified channel paths remain "
3550                                          "for the device\n");
3551                                 DBF_DEV_EVENT(DBF_WARNING, device,
3552                                               "%s", "last verified path gone");
3553                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3554                                 dasd_device_set_stop_bits(device,
3555                                                           DASD_STOPPED_DC_WAIT);
3556                         }
3557                 }
3558                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3559                         device->path_data.opm &= ~eventlpm;
3560                         device->path_data.ppm &= ~eventlpm;
3561                         device->path_data.npm &= ~eventlpm;
3562                         device->path_data.tbvpm |= eventlpm;
3563                         dasd_schedule_device_bh(device);
3564                 }
3565                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3566                         if (!(device->path_data.opm & eventlpm) &&
3567                             !(device->path_data.tbvpm & eventlpm)) {
3568                                 /*
3569                                  * we can not establish a pathgroup on an
3570                                  * unavailable path, so trigger a path
3571                                  * verification first
3572                                  */
3573                                 device->path_data.tbvpm |= eventlpm;
3574                                 dasd_schedule_device_bh(device);
3575                         }
3576                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3577                                       "Pathgroup re-established\n");
3578                         if (device->discipline->kick_validate)
3579                                 device->discipline->kick_validate(device);
3580                 }
3581         }
3582         dasd_put_device(device);
3583 }
3584 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3585
3586 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3587 {
3588         if (!device->path_data.opm && lpm) {
3589                 device->path_data.opm = lpm;
3590                 dasd_generic_path_operational(device);
3591         } else
3592                 device->path_data.opm |= lpm;
3593         return 0;
3594 }
3595 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3596
3597
3598 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3599 {
3600         struct dasd_device *device = dasd_device_from_cdev(cdev);
3601         struct list_head freeze_queue;
3602         struct dasd_ccw_req *cqr, *n;
3603         struct dasd_ccw_req *refers;
3604         int rc;
3605
3606         if (IS_ERR(device))
3607                 return PTR_ERR(device);
3608
3609         /* mark device as suspended */
3610         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3611
3612         if (device->discipline->freeze)
3613                 rc = device->discipline->freeze(device);
3614
3615         /* disallow new I/O  */
3616         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3617
3618         /* clear active requests and requeue them to block layer if possible */
3619         INIT_LIST_HEAD(&freeze_queue);
3620         spin_lock_irq(get_ccwdev_lock(cdev));
3621         rc = 0;
3622         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3623                 /* Check status and move request to flush_queue */
3624                 if (cqr->status == DASD_CQR_IN_IO) {
3625                         rc = device->discipline->term_IO(cqr);
3626                         if (rc) {
3627                                 /* unable to terminate requeust */
3628                                 dev_err(&device->cdev->dev,
3629                                         "Unable to terminate request %p "
3630                                         "on suspend\n", cqr);
3631                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3632                                 dasd_put_device(device);
3633                                 return rc;
3634                         }
3635                 }
3636                 list_move_tail(&cqr->devlist, &freeze_queue);
3637         }
3638         spin_unlock_irq(get_ccwdev_lock(cdev));
3639
3640         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3641                 wait_event(dasd_flush_wq,
3642                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3643                 if (cqr->status == DASD_CQR_CLEARED)
3644                         cqr->status = DASD_CQR_QUEUED;
3645
3646                 /* requeue requests to blocklayer will only work for
3647                    block device requests */
3648                 if (_dasd_requeue_request(cqr))
3649                         continue;
3650
3651                 /* remove requests from device and block queue */
3652                 list_del_init(&cqr->devlist);
3653                 while (cqr->refers != NULL) {
3654                         refers = cqr->refers;
3655                         /* remove the request from the block queue */
3656                         list_del(&cqr->blocklist);
3657                         /* free the finished erp request */
3658                         dasd_free_erp_request(cqr, cqr->memdev);
3659                         cqr = refers;
3660                 }
3661                 if (cqr->block)
3662                         list_del_init(&cqr->blocklist);
3663                 cqr->block->base->discipline->free_cp(
3664                         cqr, (struct request *) cqr->callback_data);
3665         }
3666
3667         /*
3668          * if requests remain then they are internal request
3669          * and go back to the device queue
3670          */
3671         if (!list_empty(&freeze_queue)) {
3672                 /* move freeze_queue to start of the ccw_queue */
3673                 spin_lock_irq(get_ccwdev_lock(cdev));
3674                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3675                 spin_unlock_irq(get_ccwdev_lock(cdev));
3676         }
3677         dasd_put_device(device);
3678         return rc;
3679 }
3680 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3681
3682 int dasd_generic_restore_device(struct ccw_device *cdev)
3683 {
3684         struct dasd_device *device = dasd_device_from_cdev(cdev);
3685         int rc = 0;
3686
3687         if (IS_ERR(device))
3688                 return PTR_ERR(device);
3689
3690         /* allow new IO again */
3691         dasd_device_remove_stop_bits(device,
3692                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3693
3694         dasd_schedule_device_bh(device);
3695
3696         /*
3697          * call discipline restore function
3698          * if device is stopped do nothing e.g. for disconnected devices
3699          */
3700         if (device->discipline->restore && !(device->stopped))
3701                 rc = device->discipline->restore(device);
3702         if (rc || device->stopped)
3703                 /*
3704                  * if the resume failed for the DASD we put it in
3705                  * an UNRESUMED stop state
3706                  */
3707                 device->stopped |= DASD_UNRESUMED_PM;
3708
3709         if (device->block)
3710                 dasd_schedule_block_bh(device->block);
3711
3712         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3713         dasd_put_device(device);
3714         return 0;
3715 }
3716 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3717
3718 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3719                                                    void *rdc_buffer,
3720                                                    int rdc_buffer_size,
3721                                                    int magic)
3722 {
3723         struct dasd_ccw_req *cqr;
3724         struct ccw1 *ccw;
3725         unsigned long *idaw;
3726
3727         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3728
3729         if (IS_ERR(cqr)) {
3730                 /* internal error 13 - Allocating the RDC request failed*/
3731                 dev_err(&device->cdev->dev,
3732                          "An error occurred in the DASD device driver, "
3733                          "reason=%s\n", "13");
3734                 return cqr;
3735         }
3736
3737         ccw = cqr->cpaddr;
3738         ccw->cmd_code = CCW_CMD_RDC;
3739         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3740                 idaw = (unsigned long *) (cqr->data);
3741                 ccw->cda = (__u32)(addr_t) idaw;
3742                 ccw->flags = CCW_FLAG_IDA;
3743                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3744         } else {
3745                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3746                 ccw->flags = 0;
3747         }
3748
3749         ccw->count = rdc_buffer_size;
3750         cqr->startdev = device;
3751         cqr->memdev = device;
3752         cqr->expires = 10*HZ;
3753         cqr->retries = 256;
3754         cqr->buildclk = get_tod_clock();
3755         cqr->status = DASD_CQR_FILLED;
3756         return cqr;
3757 }
3758
3759
3760 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3761                                 void *rdc_buffer, int rdc_buffer_size)
3762 {
3763         int ret;
3764         struct dasd_ccw_req *cqr;
3765
3766         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3767                                      magic);
3768         if (IS_ERR(cqr))
3769                 return PTR_ERR(cqr);
3770
3771         ret = dasd_sleep_on(cqr);
3772         dasd_sfree_request(cqr, cqr->memdev);
3773         return ret;
3774 }
3775 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3776
3777 /*
3778  *   In command mode and transport mode we need to look for sense
3779  *   data in different places. The sense data itself is allways
3780  *   an array of 32 bytes, so we can unify the sense data access
3781  *   for both modes.
3782  */
3783 char *dasd_get_sense(struct irb *irb)
3784 {
3785         struct tsb *tsb = NULL;
3786         char *sense = NULL;
3787
3788         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3789                 if (irb->scsw.tm.tcw)
3790                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3791                                           irb->scsw.tm.tcw);
3792                 if (tsb && tsb->length == 64 && tsb->flags)
3793                         switch (tsb->flags & 0x07) {
3794                         case 1: /* tsa_iostat */
3795                                 sense = tsb->tsa.iostat.sense;
3796                                 break;
3797                         case 2: /* tsa_ddpc */
3798                                 sense = tsb->tsa.ddpc.sense;
3799                                 break;
3800                         default:
3801                                 /* currently we don't use interrogate data */
3802                                 break;
3803                         }
3804         } else if (irb->esw.esw0.erw.cons) {
3805                 sense = irb->ecw;
3806         }
3807         return sense;
3808 }
3809 EXPORT_SYMBOL_GPL(dasd_get_sense);
3810
3811 void dasd_generic_shutdown(struct ccw_device *cdev)
3812 {
3813         struct dasd_device *device;
3814
3815         device = dasd_device_from_cdev(cdev);
3816         if (IS_ERR(device))
3817                 return;
3818
3819         if (device->block)
3820                 dasd_schedule_block_bh(device->block);
3821
3822         dasd_schedule_device_bh(device);
3823
3824         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3825 }
3826 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3827
3828 static int __init dasd_init(void)
3829 {
3830         int rc;
3831
3832         init_waitqueue_head(&dasd_init_waitq);
3833         init_waitqueue_head(&dasd_flush_wq);
3834         init_waitqueue_head(&generic_waitq);
3835         init_waitqueue_head(&shutdown_waitq);
3836
3837         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3838         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3839         if (dasd_debug_area == NULL) {
3840                 rc = -ENOMEM;
3841                 goto failed;
3842         }
3843         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3844         debug_set_level(dasd_debug_area, DBF_WARNING);
3845
3846         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3847
3848         dasd_diag_discipline_pointer = NULL;
3849
3850         dasd_statistics_createroot();
3851
3852         rc = dasd_devmap_init();
3853         if (rc)
3854                 goto failed;
3855         rc = dasd_gendisk_init();
3856         if (rc)
3857                 goto failed;
3858         rc = dasd_parse();
3859         if (rc)
3860                 goto failed;
3861         rc = dasd_eer_init();
3862         if (rc)
3863                 goto failed;
3864 #ifdef CONFIG_PROC_FS
3865         rc = dasd_proc_init();
3866         if (rc)
3867                 goto failed;
3868 #endif
3869
3870         return 0;
3871 failed:
3872         pr_info("The DASD device driver could not be initialized\n");
3873         dasd_exit();
3874         return rc;
3875 }
3876
3877 module_init(dasd_init);
3878 module_exit(dasd_exit);