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