drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 /*
  42  * SECTION: exported variables of dasd.c
  43  */
  44 debug_info_t *dasd_debug_area;
  45 EXPORT_SYMBOL(dasd_debug_area);
  46 static struct dentry *dasd_debugfs_root_entry;
  47 struct dasd_discipline *dasd_diag_discipline_pointer;
  48 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  49 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  50
  51 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  52 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  53                    " Copyright IBM Corp. 2000");
  54 MODULE_SUPPORTED_DEVICE("dasd");
  55 MODULE_LICENSE("GPL");
  56
  57 /*
  58  * SECTION: prototypes for static functions of dasd.c
  59  */
  60 static int  dasd_alloc_queue(struct dasd_block *);
  61 static void dasd_setup_queue(struct dasd_block *);
  62 static void dasd_free_queue(struct dasd_block *);
  63 static void dasd_flush_request_queue(struct dasd_block *);
  64 static int dasd_flush_block_queue(struct dasd_block *);
  65 static void dasd_device_tasklet(struct dasd_device *);
  66 static void dasd_block_tasklet(struct dasd_block *);
  67 static void do_kick_device(struct work_struct *);
  68 static void do_restore_device(struct work_struct *);
  69 static void do_reload_device(struct work_struct *);
  70 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  71 static void dasd_device_timeout(unsigned long);
  72 static void dasd_block_timeout(unsigned long);
  73 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  74 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  75 static void dasd_profile_exit(struct dasd_profile *);
  76
  77 /*
  78  * SECTION: Operations on the device structure.
  79  */
  80 static wait_queue_head_t dasd_init_waitq;
  81 static wait_queue_head_t dasd_flush_wq;
  82 static wait_queue_head_t generic_waitq;
  83 static wait_queue_head_t shutdown_waitq;
  84
  85 /*
  86  * Allocate memory for a new device structure.
  87  */
  88 struct dasd_device *dasd_alloc_device(void)
  89 {
  90         struct dasd_device *device;
  91
  92         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  93         if (!device)
  94                 return ERR_PTR(-ENOMEM);
  95
  96         /* Get two pages for normal block device operations. */
  97         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  98         if (!device->ccw_mem) {
  99                 kfree(device);
 100                 return ERR_PTR(-ENOMEM);
 101         }
 102         /* Get one page for error recovery. */
 103         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 104         if (!device->erp_mem) {
 105                 free_pages((unsigned long) device->ccw_mem, 1);
 106                 kfree(device);
 107                 return ERR_PTR(-ENOMEM);
 108         }
 109
 110         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 111         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 112         spin_lock_init(&device->mem_lock);
 113         atomic_set(&device->tasklet_scheduled, 0);
 114         tasklet_init(&device->tasklet,
 115                      (void (*)(unsigned long)) dasd_device_tasklet,
 116                      (unsigned long) device);
 117         INIT_LIST_HEAD(&device->ccw_queue);
 118         init_timer(&device->timer);
 119         device->timer.function = dasd_device_timeout;
 120         device->timer.data = (unsigned long) device;
 121         INIT_WORK(&device->kick_work, do_kick_device);
 122         INIT_WORK(&device->restore_device, do_restore_device);
 123         INIT_WORK(&device->reload_device, do_reload_device);
 124         device->state = DASD_STATE_NEW;
 125         device->target = DASD_STATE_NEW;
 126         mutex_init(&device->state_mutex);
 127         spin_lock_init(&device->profile.lock);
 128         return device;
 129 }
 130
 131 /*
 132  * Free memory of a device structure.
 133  */
 134 void dasd_free_device(struct dasd_device *device)
 135 {
 136         kfree(device->private);
 137         free_page((unsigned long) device->erp_mem);
 138         free_pages((unsigned long) device->ccw_mem, 1);
 139         kfree(device);
 140 }
 141
 142 /*
 143  * Allocate memory for a new device structure.
 144  */
 145 struct dasd_block *dasd_alloc_block(void)
 146 {
 147         struct dasd_block *block;
 148
 149         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 150         if (!block)
 151                 return ERR_PTR(-ENOMEM);
 152         /* open_count = 0 means device online but not in use */
 153         atomic_set(&block->open_count, -1);
 154
 155         spin_lock_init(&block->request_queue_lock);
 156         atomic_set(&block->tasklet_scheduled, 0);
 157         tasklet_init(&block->tasklet,
 158                      (void (*)(unsigned long)) dasd_block_tasklet,
 159                      (unsigned long) block);
 160         INIT_LIST_HEAD(&block->ccw_queue);
 161         spin_lock_init(&block->queue_lock);
 162         init_timer(&block->timer);
 163         block->timer.function = dasd_block_timeout;
 164         block->timer.data = (unsigned long) block;
 165         spin_lock_init(&block->profile.lock);
 166
 167         return block;
 168 }
 169 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 170
 171 /*
 172  * Free memory of a device structure.
 173  */
 174 void dasd_free_block(struct dasd_block *block)
 175 {
 176         kfree(block);
 177 }
 178 EXPORT_SYMBOL_GPL(dasd_free_block);
 179
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         int rc;
 186
 187         /*
 188          * As long as the device is not in state DASD_STATE_NEW we want to
 189          * keep the reference count > 0.
 190          */
 191         dasd_get_device(device);
 192
 193         if (device->block) {
 194                 rc = dasd_alloc_queue(device->block);
 195                 if (rc) {
 196                         dasd_put_device(device);
 197                         return rc;
 198                 }
 199         }
 200         device->state = DASD_STATE_KNOWN;
 201         return 0;
 202 }
 203
 204 /*
 205  * Let the system forget about a device.
 206  */
 207 static int dasd_state_known_to_new(struct dasd_device *device)
 208 {
 209         /* Disable extended error reporting for this device. */
 210         dasd_eer_disable(device);
 211         /* Forget the discipline information. */
 212         if (device->discipline) {
 213                 if (device->discipline->uncheck_device)
 214                         device->discipline->uncheck_device(device);
 215                 module_put(device->discipline->owner);
 216         }
 217         device->discipline = NULL;
 218         if (device->base_discipline)
 219                 module_put(device->base_discipline->owner);
 220         device->base_discipline = NULL;
 221         device->state = DASD_STATE_NEW;
 222
 223         if (device->block)
 224                 dasd_free_queue(device->block);
 225
 226         /* Give up reference we took in dasd_state_new_to_known. */
 227         dasd_put_device(device);
 228         return 0;
 229 }
 230
 231 static struct dentry *dasd_debugfs_setup(const char *name,
 232                                          struct dentry *base_dentry)
 233 {
 234         struct dentry *pde;
 235
 236         if (!base_dentry)
 237                 return NULL;
 238         pde = debugfs_create_dir(name, base_dentry);
 239         if (!pde || IS_ERR(pde))
 240                 return NULL;
 241         return pde;
 242 }
 243
 244 /*
 245  * Request the irq line for the device.
 246  */
 247 static int dasd_state_known_to_basic(struct dasd_device *device)
 248 {
 249         struct dasd_block *block = device->block;
 250         int rc = 0;
 251
 252         /* Allocate and register gendisk structure. */
 253         if (block) {
 254                 rc = dasd_gendisk_alloc(block);
 255                 if (rc)
 256                         return rc;
 257                 block->debugfs_dentry =
 258                         dasd_debugfs_setup(block->gdp->disk_name,
 259                                            dasd_debugfs_root_entry);
 260                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 261                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 262                         dasd_profile_on(&device->block->profile);
 263         }
 264         device->debugfs_dentry =
 265                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 266                                    dasd_debugfs_root_entry);
 267         dasd_profile_init(&device->profile, device->debugfs_dentry);
 268
 269         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 270         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 271                                             8 * sizeof(long));
 272         debug_register_view(device->debug_area, &debug_sprintf_view);
 273         debug_set_level(device->debug_area, DBF_WARNING);
 274         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 275
 276         device->state = DASD_STATE_BASIC;
 277
 278         return rc;
 279 }
 280
 281 /*
 282  * Release the irq line for the device. Terminate any running i/o.
 283  */
 284 static int dasd_state_basic_to_known(struct dasd_device *device)
 285 {
 286         int rc;
 287
 288         if (device->discipline->basic_to_known) {
 289                 rc = device->discipline->basic_to_known(device);
 290                 if (rc)
 291                         return rc;
 292         }
 293
 294         if (device->block) {
 295                 dasd_profile_exit(&device->block->profile);
 296                 debugfs_remove(device->block->debugfs_dentry);
 297                 dasd_gendisk_free(device->block);
 298                 dasd_block_clear_timer(device->block);
 299         }
 300         rc = dasd_flush_device_queue(device);
 301         if (rc)
 302                 return rc;
 303         dasd_device_clear_timer(device);
 304         dasd_profile_exit(&device->profile);
 305         debugfs_remove(device->debugfs_dentry);
 306         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 307         if (device->debug_area != NULL) {
 308                 debug_unregister(device->debug_area);
 309                 device->debug_area = NULL;
 310         }
 311         device->state = DASD_STATE_KNOWN;
 312         return 0;
 313 }
 314
 315 /*
 316  * Do the initial analysis. The do_analysis function may return
 317  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 318  * until the discipline decides to continue the startup sequence
 319  * by calling the function dasd_change_state. The eckd disciplines
 320  * uses this to start a ccw that detects the format. The completion
 321  * interrupt for this detection ccw uses the kernel event daemon to
 322  * trigger the call to dasd_change_state. All this is done in the
 323  * discipline code, see dasd_eckd.c.
 324  * After the analysis ccw is done (do_analysis returned 0) the block
 325  * device is setup.
 326  * In case the analysis returns an error, the device setup is stopped
 327  * (a fake disk was already added to allow formatting).
 328  */
 329 static int dasd_state_basic_to_ready(struct dasd_device *device)
 330 {
 331         int rc;
 332         struct dasd_block *block;
 333
 334         rc = 0;
 335         block = device->block;
 336         /* make disk known with correct capacity */
 337         if (block) {
 338                 if (block->base->discipline->do_analysis != NULL)
 339                         rc = block->base->discipline->do_analysis(block);
 340                 if (rc) {
 341                         if (rc != -EAGAIN) {
 342                                 device->state = DASD_STATE_UNFMT;
 343                                 goto out;
 344                         }
 345                         return rc;
 346                 }
 347                 dasd_setup_queue(block);
 348                 set_capacity(block->gdp,
 349                              block->blocks << block->s2b_shift);
 350                 device->state = DASD_STATE_READY;
 351                 rc = dasd_scan_partitions(block);
 352                 if (rc) {
 353                         device->state = DASD_STATE_BASIC;
 354                         return rc;
 355                 }
 356         } else {
 357                 device->state = DASD_STATE_READY;
 358         }
 359 out:
 360         if (device->discipline->basic_to_ready)
 361                 rc = device->discipline->basic_to_ready(device);
 362         return rc;
 363 }
 364
 365 static inline
 366 int _wait_for_empty_queues(struct dasd_device *device)
 367 {
 368         if (device->block)
 369                 return list_empty(&device->ccw_queue) &&
 370                         list_empty(&device->block->ccw_queue);
 371         else
 372                 return list_empty(&device->ccw_queue);
 373 }
 374
 375 /*
 376  * Remove device from block device layer. Destroy dirty buffers.
 377  * Forget format information. Check if the target level is basic
 378  * and if it is create fake disk for formatting.
 379  */
 380 static int dasd_state_ready_to_basic(struct dasd_device *device)
 381 {
 382         int rc;
 383
 384         device->state = DASD_STATE_BASIC;
 385         if (device->block) {
 386                 struct dasd_block *block = device->block;
 387                 rc = dasd_flush_block_queue(block);
 388                 if (rc) {
 389                         device->state = DASD_STATE_READY;
 390                         return rc;
 391                 }
 392                 dasd_flush_request_queue(block);
 393                 dasd_destroy_partitions(block);
 394                 block->blocks = 0;
 395                 block->bp_block = 0;
 396                 block->s2b_shift = 0;
 397         }
 398         return 0;
 399 }
 400
 401 /*
 402  * Back to basic.
 403  */
 404 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 405 {
 406         device->state = DASD_STATE_BASIC;
 407         return 0;
 408 }
 409
 410 /*
 411  * Make the device online and schedule the bottom half to start
 412  * the requeueing of requests from the linux request queue to the
 413  * ccw queue.
 414  */
 415 static int
 416 dasd_state_ready_to_online(struct dasd_device * device)
 417 {
 418         struct gendisk *disk;
 419         struct disk_part_iter piter;
 420         struct hd_struct *part;
 421
 422         device->state = DASD_STATE_ONLINE;
 423         if (device->block) {
 424                 dasd_schedule_block_bh(device->block);
 425                 if ((device->features & DASD_FEATURE_USERAW)) {
 426                         disk = device->block->gdp;
 427                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 428                         return 0;
 429                 }
 430                 disk = device->block->bdev->bd_disk;
 431                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 432                 while ((part = disk_part_iter_next(&piter)))
 433                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 434                 disk_part_iter_exit(&piter);
 435         }
 436         return 0;
 437 }
 438
 439 /*
 440  * Stop the requeueing of requests again.
 441  */
 442 static int dasd_state_online_to_ready(struct dasd_device *device)
 443 {
 444         int rc;
 445         struct gendisk *disk;
 446         struct disk_part_iter piter;
 447         struct hd_struct *part;
 448
 449         if (device->discipline->online_to_ready) {
 450                 rc = device->discipline->online_to_ready(device);
 451                 if (rc)
 452                         return rc;
 453         }
 454
 455         device->state = DASD_STATE_READY;
 456         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 457                 disk = device->block->bdev->bd_disk;
 458                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 459                 while ((part = disk_part_iter_next(&piter)))
 460                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 461                 disk_part_iter_exit(&piter);
 462         }
 463         return 0;
 464 }
 465
 466 /*
 467  * Device startup state changes.
 468  */
 469 static int dasd_increase_state(struct dasd_device *device)
 470 {
 471         int rc;
 472
 473         rc = 0;
 474         if (device->state == DASD_STATE_NEW &&
 475             device->target >= DASD_STATE_KNOWN)
 476                 rc = dasd_state_new_to_known(device);
 477
 478         if (!rc &&
 479             device->state == DASD_STATE_KNOWN &&
 480             device->target >= DASD_STATE_BASIC)
 481                 rc = dasd_state_known_to_basic(device);
 482
 483         if (!rc &&
 484             device->state == DASD_STATE_BASIC &&
 485             device->target >= DASD_STATE_READY)
 486                 rc = dasd_state_basic_to_ready(device);
 487
 488         if (!rc &&
 489             device->state == DASD_STATE_UNFMT &&
 490             device->target > DASD_STATE_UNFMT)
 491                 rc = -EPERM;
 492
 493         if (!rc &&
 494             device->state == DASD_STATE_READY &&
 495             device->target >= DASD_STATE_ONLINE)
 496                 rc = dasd_state_ready_to_online(device);
 497
 498         return rc;
 499 }
 500
 501 /*
 502  * Device shutdown state changes.
 503  */
 504 static int dasd_decrease_state(struct dasd_device *device)
 505 {
 506         int rc;
 507
 508         rc = 0;
 509         if (device->state == DASD_STATE_ONLINE &&
 510             device->target <= DASD_STATE_READY)
 511                 rc = dasd_state_online_to_ready(device);
 512
 513         if (!rc &&
 514             device->state == DASD_STATE_READY &&
 515             device->target <= DASD_STATE_BASIC)
 516                 rc = dasd_state_ready_to_basic(device);
 517
 518         if (!rc &&
 519             device->state == DASD_STATE_UNFMT &&
 520             device->target <= DASD_STATE_BASIC)
 521                 rc = dasd_state_unfmt_to_basic(device);
 522
 523         if (!rc &&
 524             device->state == DASD_STATE_BASIC &&
 525             device->target <= DASD_STATE_KNOWN)
 526                 rc = dasd_state_basic_to_known(device);
 527
 528         if (!rc &&
 529             device->state == DASD_STATE_KNOWN &&
 530             device->target <= DASD_STATE_NEW)
 531                 rc = dasd_state_known_to_new(device);
 532
 533         return rc;
 534 }
 535
 536 /*
 537  * This is the main startup/shutdown routine.
 538  */
 539 static void dasd_change_state(struct dasd_device *device)
 540 {
 541         int rc;
 542
 543         if (device->state == device->target)
 544                 /* Already where we want to go today... */
 545                 return;
 546         if (device->state < device->target)
 547                 rc = dasd_increase_state(device);
 548         else
 549                 rc = dasd_decrease_state(device);
 550         if (rc == -EAGAIN)
 551                 return;
 552         if (rc)
 553                 device->target = device->state;
 554
 555         /* let user-space know that the device status changed */
 556         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 557
 558         if (device->state == device->target)
 559                 wake_up(&dasd_init_waitq);
 560 }
 561
 562 /*
 563  * Kick starter for devices that did not complete the startup/shutdown
 564  * procedure or were sleeping because of a pending state.
 565  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 566  * event daemon.
 567  */
 568 static void do_kick_device(struct work_struct *work)
 569 {
 570         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 571         mutex_lock(&device->state_mutex);
 572         dasd_change_state(device);
 573         mutex_unlock(&device->state_mutex);
 574         dasd_schedule_device_bh(device);
 575         dasd_put_device(device);
 576 }
 577
 578 void dasd_kick_device(struct dasd_device *device)
 579 {
 580         dasd_get_device(device);
 581         /* queue call to dasd_kick_device to the kernel event daemon. */
 582         schedule_work(&device->kick_work);
 583 }
 584 EXPORT_SYMBOL(dasd_kick_device);
 585
 586 /*
 587  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 588  * event daemon.
 589  */
 590 static void do_reload_device(struct work_struct *work)
 591 {
 592         struct dasd_device *device = container_of(work, struct dasd_device,
 593                                                   reload_device);
 594         device->discipline->reload(device);
 595         dasd_put_device(device);
 596 }
 597
 598 void dasd_reload_device(struct dasd_device *device)
 599 {
 600         dasd_get_device(device);
 601         /* queue call to dasd_reload_device to the kernel event daemon. */
 602         schedule_work(&device->reload_device);
 603 }
 604 EXPORT_SYMBOL(dasd_reload_device);
 605
 606 /*
 607  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 608  * event daemon.
 609  */
 610 static void do_restore_device(struct work_struct *work)
 611 {
 612         struct dasd_device *device = container_of(work, struct dasd_device,
 613                                                   restore_device);
 614         device->cdev->drv->restore(device->cdev);
 615         dasd_put_device(device);
 616 }
 617
 618 void dasd_restore_device(struct dasd_device *device)
 619 {
 620         dasd_get_device(device);
 621         /* queue call to dasd_restore_device to the kernel event daemon. */
 622         schedule_work(&device->restore_device);
 623 }
 624
 625 /*
 626  * Set the target state for a device and starts the state change.
 627  */
 628 void dasd_set_target_state(struct dasd_device *device, int target)
 629 {
 630         dasd_get_device(device);
 631         mutex_lock(&device->state_mutex);
 632         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 633         if (dasd_probeonly && target > DASD_STATE_READY)
 634                 target = DASD_STATE_READY;
 635         if (device->target != target) {
 636                 if (device->state == target)
 637                         wake_up(&dasd_init_waitq);
 638                 device->target = target;
 639         }
 640         if (device->state != device->target)
 641                 dasd_change_state(device);
 642         mutex_unlock(&device->state_mutex);
 643         dasd_put_device(device);
 644 }
 645 EXPORT_SYMBOL(dasd_set_target_state);
 646
 647 /*
 648  * Enable devices with device numbers in [from..to].
 649  */
 650 static inline int _wait_for_device(struct dasd_device *device)
 651 {
 652         return (device->state == device->target);
 653 }
 654
 655 void dasd_enable_device(struct dasd_device *device)
 656 {
 657         dasd_set_target_state(device, DASD_STATE_ONLINE);
 658         if (device->state <= DASD_STATE_KNOWN)
 659                 /* No discipline for device found. */
 660                 dasd_set_target_state(device, DASD_STATE_NEW);
 661         /* Now wait for the devices to come up. */
 662         wait_event(dasd_init_waitq, _wait_for_device(device));
 663
 664         dasd_reload_device(device);
 665         if (device->discipline->kick_validate)
 666                 device->discipline->kick_validate(device);
 667 }
 668 EXPORT_SYMBOL(dasd_enable_device);
 669
 670 /*
 671  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 672  */
 673
 674 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 675
 676 #ifdef CONFIG_DASD_PROFILE
 677 struct dasd_profile_info dasd_global_profile_data;
 678 static struct dentry *dasd_global_profile_dentry;
 679 static struct dentry *dasd_debugfs_global_entry;
 680
 681 /*
 682  * Add profiling information for cqr before execution.
 683  */
 684 static void dasd_profile_start(struct dasd_block *block,
 685                                struct dasd_ccw_req *cqr,
 686                                struct request *req)
 687 {
 688         struct list_head *l;
 689         unsigned int counter;
 690         struct dasd_device *device;
 691
 692         /* count the length of the chanq for statistics */
 693         counter = 0;
 694         if (dasd_global_profile_level || block->profile.data)
 695                 list_for_each(l, &block->ccw_queue)
 696                         if (++counter >= 31)
 697                                 break;
 698
 699         if (dasd_global_profile_level) {
 700                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 701                 if (rq_data_dir(req) == READ)
 702                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 703         }
 704
 705         spin_lock(&block->profile.lock);
 706         if (block->profile.data) {
 707                 block->profile.data->dasd_io_nr_req[counter]++;
 708                 if (rq_data_dir(req) == READ)
 709                         block->profile.data->dasd_read_nr_req[counter]++;
 710         }
 711         spin_unlock(&block->profile.lock);
 712
 713         /*
 714          * We count the request for the start device, even though it may run on
 715          * some other device due to error recovery. This way we make sure that
 716          * we count each request only once.
 717          */
 718         device = cqr->startdev;
 719         if (device->profile.data) {
 720                 counter = 1; /* request is not yet queued on the start device */
 721                 list_for_each(l, &device->ccw_queue)
 722                         if (++counter >= 31)
 723                                 break;
 724         }
 725         spin_lock(&device->profile.lock);
 726         if (device->profile.data) {
 727                 device->profile.data->dasd_io_nr_req[counter]++;
 728                 if (rq_data_dir(req) == READ)
 729                         device->profile.data->dasd_read_nr_req[counter]++;
 730         }
 731         spin_unlock(&device->profile.lock);
 732 }
 733
 734 /*
 735  * Add profiling information for cqr after execution.
 736  */
 737
 738 #define dasd_profile_counter(value, index)                         \
 739 {                                                                  \
 740         for (index = 0; index < 31 && value >> (2+index); index++) \
 741                 ;                                                  \
 742 }
 743
 744 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 745                                       int is_alias,
 746                                       int is_tpm,
 747                                       int is_read,
 748                                       long sectors,
 749                                       int sectors_ind,
 750                                       int tottime_ind,
 751                                       int tottimeps_ind,
 752                                       int strtime_ind,
 753                                       int irqtime_ind,
 754                                       int irqtimeps_ind,
 755                                       int endtime_ind)
 756 {
 757         /* in case of an overflow, reset the whole profile */
 758         if (data->dasd_io_reqs == UINT_MAX) {
 759                         memset(data, 0, sizeof(*data));
 760                         getnstimeofday(&data->starttod);
 761         }
 762         data->dasd_io_reqs++;
 763         data->dasd_io_sects += sectors;
 764         if (is_alias)
 765                 data->dasd_io_alias++;
 766         if (is_tpm)
 767                 data->dasd_io_tpm++;
 768
 769         data->dasd_io_secs[sectors_ind]++;
 770         data->dasd_io_times[tottime_ind]++;
 771         data->dasd_io_timps[tottimeps_ind]++;
 772         data->dasd_io_time1[strtime_ind]++;
 773         data->dasd_io_time2[irqtime_ind]++;
 774         data->dasd_io_time2ps[irqtimeps_ind]++;
 775         data->dasd_io_time3[endtime_ind]++;
 776
 777         if (is_read) {
 778                 data->dasd_read_reqs++;
 779                 data->dasd_read_sects += sectors;
 780                 if (is_alias)
 781                         data->dasd_read_alias++;
 782                 if (is_tpm)
 783                         data->dasd_read_tpm++;
 784                 data->dasd_read_secs[sectors_ind]++;
 785                 data->dasd_read_times[tottime_ind]++;
 786                 data->dasd_read_time1[strtime_ind]++;
 787                 data->dasd_read_time2[irqtime_ind]++;
 788                 data->dasd_read_time3[endtime_ind]++;
 789         }
 790 }
 791
 792 static void dasd_profile_end(struct dasd_block *block,
 793                              struct dasd_ccw_req *cqr,
 794                              struct request *req)
 795 {
 796         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 797         long tottimeps, sectors;
 798         struct dasd_device *device;
 799         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 800         int irqtime_ind, irqtimeps_ind, endtime_ind;
 801
 802         device = cqr->startdev;
 803         if (!(dasd_global_profile_level ||
 804               block->profile.data ||
 805               device->profile.data))
 806                 return;
 807
 808         sectors = blk_rq_sectors(req);
 809         if (!cqr->buildclk || !cqr->startclk ||
 810             !cqr->stopclk || !cqr->endclk ||
 811             !sectors)
 812                 return;
 813
 814         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 815         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 816         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 817         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 818         tottimeps = tottime / sectors;
 819
 820         dasd_profile_counter(sectors, sectors_ind);
 821         dasd_profile_counter(tottime, tottime_ind);
 822         dasd_profile_counter(tottimeps, tottimeps_ind);
 823         dasd_profile_counter(strtime, strtime_ind);
 824         dasd_profile_counter(irqtime, irqtime_ind);
 825         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 826         dasd_profile_counter(endtime, endtime_ind);
 827
 828         if (dasd_global_profile_level) {
 829                 dasd_profile_end_add_data(&dasd_global_profile_data,
 830                                           cqr->startdev != block->base,
 831                                           cqr->cpmode == 1,
 832                                           rq_data_dir(req) == READ,
 833                                           sectors, sectors_ind, tottime_ind,
 834                                           tottimeps_ind, strtime_ind,
 835                                           irqtime_ind, irqtimeps_ind,
 836                                           endtime_ind);
 837         }
 838
 839         spin_lock(&block->profile.lock);
 840         if (block->profile.data)
 841                 dasd_profile_end_add_data(block->profile.data,
 842                                           cqr->startdev != block->base,
 843                                           cqr->cpmode == 1,
 844                                           rq_data_dir(req) == READ,
 845                                           sectors, sectors_ind, tottime_ind,
 846                                           tottimeps_ind, strtime_ind,
 847                                           irqtime_ind, irqtimeps_ind,
 848                                           endtime_ind);
 849         spin_unlock(&block->profile.lock);
 850
 851         spin_lock(&device->profile.lock);
 852         if (device->profile.data)
 853                 dasd_profile_end_add_data(device->profile.data,
 854                                           cqr->startdev != block->base,
 855                                           cqr->cpmode == 1,
 856                                           rq_data_dir(req) == READ,
 857                                           sectors, sectors_ind, tottime_ind,
 858                                           tottimeps_ind, strtime_ind,
 859                                           irqtime_ind, irqtimeps_ind,
 860                                           endtime_ind);
 861         spin_unlock(&device->profile.lock);
 862 }
 863
 864 void dasd_profile_reset(struct dasd_profile *profile)
 865 {
 866         struct dasd_profile_info *data;
 867
 868         spin_lock_bh(&profile->lock);
 869         data = profile->data;
 870         if (!data) {
 871                 spin_unlock_bh(&profile->lock);
 872                 return;
 873         }
 874         memset(data, 0, sizeof(*data));
 875         getnstimeofday(&data->starttod);
 876         spin_unlock_bh(&profile->lock);
 877 }
 878
 879 void dasd_global_profile_reset(void)
 880 {
 881         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 882         getnstimeofday(&dasd_global_profile_data.starttod);
 883 }
 884
 885 int dasd_profile_on(struct dasd_profile *profile)
 886 {
 887         struct dasd_profile_info *data;
 888
 889         data = kzalloc(sizeof(*data), GFP_KERNEL);
 890         if (!data)
 891                 return -ENOMEM;
 892         spin_lock_bh(&profile->lock);
 893         if (profile->data) {
 894                 spin_unlock_bh(&profile->lock);
 895                 kfree(data);
 896                 return 0;
 897         }
 898         getnstimeofday(&data->starttod);
 899         profile->data = data;
 900         spin_unlock_bh(&profile->lock);
 901         return 0;
 902 }
 903
 904 void dasd_profile_off(struct dasd_profile *profile)
 905 {
 906         spin_lock_bh(&profile->lock);
 907         kfree(profile->data);
 908         profile->data = NULL;
 909         spin_unlock_bh(&profile->lock);
 910 }
 911
 912 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 913 {
 914         char *buffer;
 915
 916         buffer = vmalloc(user_len + 1);
 917         if (buffer == NULL)
 918                 return ERR_PTR(-ENOMEM);
 919         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 920                 vfree(buffer);
 921                 return ERR_PTR(-EFAULT);
 922         }
 923         /* got the string, now strip linefeed. */
 924         if (buffer[user_len - 1] == '\n')
 925                 buffer[user_len - 1] = 0;
 926         else
 927                 buffer[user_len] = 0;
 928         return buffer;
 929 }
 930
 931 static ssize_t dasd_stats_write(struct file *file,
 932                                 const char __user *user_buf,
 933                                 size_t user_len, loff_t *pos)
 934 {
 935         char *buffer, *str;
 936         int rc;
 937         struct seq_file *m = (struct seq_file *)file->private_data;
 938         struct dasd_profile *prof = m->private;
 939
 940         if (user_len > 65536)
 941                 user_len = 65536;
 942         buffer = dasd_get_user_string(user_buf, user_len);
 943         if (IS_ERR(buffer))
 944                 return PTR_ERR(buffer);
 945
 946         str = skip_spaces(buffer);
 947         rc = user_len;
 948         if (strncmp(str, "reset", 5) == 0) {
 949                 dasd_profile_reset(prof);
 950         } else if (strncmp(str, "on", 2) == 0) {
 951                 rc = dasd_profile_on(prof);
 952                 if (!rc)
 953                         rc = user_len;
 954         } else if (strncmp(str, "off", 3) == 0) {
 955                 dasd_profile_off(prof);
 956         } else
 957                 rc = -EINVAL;
 958         vfree(buffer);
 959         return rc;
 960 }
 961
 962 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 963 {
 964         int i;
 965
 966         for (i = 0; i < 32; i++)
 967                 seq_printf(m, "%u ", array[i]);
 968         seq_putc(m, '\n');
 969 }
 970
 971 static void dasd_stats_seq_print(struct seq_file *m,
 972                                  struct dasd_profile_info *data)
 973 {
 974         seq_printf(m, "start_time %ld.%09ld\n",
 975                    data->starttod.tv_sec, data->starttod.tv_nsec);
 976         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 977         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 978         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 979         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 980         seq_puts(m, "histogram_sectors ");
 981         dasd_stats_array(m, data->dasd_io_secs);
 982         seq_puts(m, "histogram_io_times ");
 983         dasd_stats_array(m, data->dasd_io_times);
 984         seq_puts(m, "histogram_io_times_weighted ");
 985         dasd_stats_array(m, data->dasd_io_timps);
 986         seq_puts(m, "histogram_time_build_to_ssch ");
 987         dasd_stats_array(m, data->dasd_io_time1);
 988         seq_puts(m, "histogram_time_ssch_to_irq ");
 989         dasd_stats_array(m, data->dasd_io_time2);
 990         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
 991         dasd_stats_array(m, data->dasd_io_time2ps);
 992         seq_puts(m, "histogram_time_irq_to_end ");
 993         dasd_stats_array(m, data->dasd_io_time3);
 994         seq_puts(m, "histogram_ccw_queue_length ");
 995         dasd_stats_array(m, data->dasd_io_nr_req);
 996         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 997         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 998         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 999         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1000         seq_puts(m, "histogram_read_sectors ");
1001         dasd_stats_array(m, data->dasd_read_secs);
1002         seq_puts(m, "histogram_read_times ");
1003         dasd_stats_array(m, data->dasd_read_times);
1004         seq_puts(m, "histogram_read_time_build_to_ssch ");
1005         dasd_stats_array(m, data->dasd_read_time1);
1006         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1007         dasd_stats_array(m, data->dasd_read_time2);
1008         seq_puts(m, "histogram_read_time_irq_to_end ");
1009         dasd_stats_array(m, data->dasd_read_time3);
1010         seq_puts(m, "histogram_read_ccw_queue_length ");
1011         dasd_stats_array(m, data->dasd_read_nr_req);
1012 }
1013
1014 static int dasd_stats_show(struct seq_file *m, void *v)
1015 {
1016         struct dasd_profile *profile;
1017         struct dasd_profile_info *data;
1018
1019         profile = m->private;
1020         spin_lock_bh(&profile->lock);
1021         data = profile->data;
1022         if (!data) {
1023                 spin_unlock_bh(&profile->lock);
1024                 seq_puts(m, "disabled\n");
1025                 return 0;
1026         }
1027         dasd_stats_seq_print(m, data);
1028         spin_unlock_bh(&profile->lock);
1029         return 0;
1030 }
1031
1032 static int dasd_stats_open(struct inode *inode, struct file *file)
1033 {
1034         struct dasd_profile *profile = inode->i_private;
1035         return single_open(file, dasd_stats_show, profile);
1036 }
1037
1038 static const struct file_operations dasd_stats_raw_fops = {
1039         .owner          = THIS_MODULE,
1040         .open           = dasd_stats_open,
1041         .read           = seq_read,
1042         .llseek         = seq_lseek,
1043         .release        = single_release,
1044         .write          = dasd_stats_write,
1045 };
1046
1047 static ssize_t dasd_stats_global_write(struct file *file,
1048                                        const char __user *user_buf,
1049                                        size_t user_len, loff_t *pos)
1050 {
1051         char *buffer, *str;
1052         ssize_t rc;
1053
1054         if (user_len > 65536)
1055                 user_len = 65536;
1056         buffer = dasd_get_user_string(user_buf, user_len);
1057         if (IS_ERR(buffer))
1058                 return PTR_ERR(buffer);
1059         str = skip_spaces(buffer);
1060         rc = user_len;
1061         if (strncmp(str, "reset", 5) == 0) {
1062                 dasd_global_profile_reset();
1063         } else if (strncmp(str, "on", 2) == 0) {
1064                 dasd_global_profile_reset();
1065                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1066         } else if (strncmp(str, "off", 3) == 0) {
1067                 dasd_global_profile_level = DASD_PROFILE_OFF;
1068         } else
1069                 rc = -EINVAL;
1070         vfree(buffer);
1071         return rc;
1072 }
1073
1074 static int dasd_stats_global_show(struct seq_file *m, void *v)
1075 {
1076         if (!dasd_global_profile_level) {
1077                 seq_puts(m, "disabled\n");
1078                 return 0;
1079         }
1080         dasd_stats_seq_print(m, &dasd_global_profile_data);
1081         return 0;
1082 }
1083
1084 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1085 {
1086         return single_open(file, dasd_stats_global_show, NULL);
1087 }
1088
1089 static const struct file_operations dasd_stats_global_fops = {
1090         .owner          = THIS_MODULE,
1091         .open           = dasd_stats_global_open,
1092         .read           = seq_read,
1093         .llseek         = seq_lseek,
1094         .release        = single_release,
1095         .write          = dasd_stats_global_write,
1096 };
1097
1098 static void dasd_profile_init(struct dasd_profile *profile,
1099                               struct dentry *base_dentry)
1100 {
1101         umode_t mode;
1102         struct dentry *pde;
1103
1104         if (!base_dentry)
1105                 return;
1106         profile->dentry = NULL;
1107         profile->data = NULL;
1108         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1109         pde = debugfs_create_file("statistics", mode, base_dentry,
1110                                   profile, &dasd_stats_raw_fops);
1111         if (pde && !IS_ERR(pde))
1112                 profile->dentry = pde;
1113         return;
1114 }
1115
1116 static void dasd_profile_exit(struct dasd_profile *profile)
1117 {
1118         dasd_profile_off(profile);
1119         debugfs_remove(profile->dentry);
1120         profile->dentry = NULL;
1121 }
1122
1123 static void dasd_statistics_removeroot(void)
1124 {
1125         dasd_global_profile_level = DASD_PROFILE_OFF;
1126         debugfs_remove(dasd_global_profile_dentry);
1127         dasd_global_profile_dentry = NULL;
1128         debugfs_remove(dasd_debugfs_global_entry);
1129         debugfs_remove(dasd_debugfs_root_entry);
1130 }
1131
1132 static void dasd_statistics_createroot(void)
1133 {
1134         umode_t mode;
1135         struct dentry *pde;
1136
1137         dasd_debugfs_root_entry = NULL;
1138         dasd_debugfs_global_entry = NULL;
1139         dasd_global_profile_dentry = NULL;
1140         pde = debugfs_create_dir("dasd", NULL);
1141         if (!pde || IS_ERR(pde))
1142                 goto error;
1143         dasd_debugfs_root_entry = pde;
1144         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1145         if (!pde || IS_ERR(pde))
1146                 goto error;
1147         dasd_debugfs_global_entry = pde;
1148
1149         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1150         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1151                                   NULL, &dasd_stats_global_fops);
1152         if (!pde || IS_ERR(pde))
1153                 goto error;
1154         dasd_global_profile_dentry = pde;
1155         return;
1156
1157 error:
1158         DBF_EVENT(DBF_ERR, "%s",
1159                   "Creation of the dasd debugfs interface failed");
1160         dasd_statistics_removeroot();
1161         return;
1162 }
1163
1164 #else
1165 #define dasd_profile_start(block, cqr, req) do {} while (0)
1166 #define dasd_profile_end(block, cqr, req) do {} while (0)
1167
1168 static void dasd_statistics_createroot(void)
1169 {
1170         return;
1171 }
1172
1173 static void dasd_statistics_removeroot(void)
1174 {
1175         return;
1176 }
1177
1178 int dasd_stats_generic_show(struct seq_file *m, void *v)
1179 {
1180         seq_puts(m, "Statistics are not activated in this kernel\n");
1181         return 0;
1182 }
1183
1184 static void dasd_profile_init(struct dasd_profile *profile,
1185                               struct dentry *base_dentry)
1186 {
1187         return;
1188 }
1189
1190 static void dasd_profile_exit(struct dasd_profile *profile)
1191 {
1192         return;
1193 }
1194
1195 int dasd_profile_on(struct dasd_profile *profile)
1196 {
1197         return 0;
1198 }
1199
1200 #endif                          /* CONFIG_DASD_PROFILE */
1201
1202 /*
1203  * Allocate memory for a channel program with 'cplength' channel
1204  * command words and 'datasize' additional space. There are two
1205  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1206  * memory and 2) dasd_smalloc_request uses the static ccw memory
1207  * that gets allocated for each device.
1208  */
1209 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1210                                           int datasize,
1211                                           struct dasd_device *device)
1212 {
1213         struct dasd_ccw_req *cqr;
1214
1215         /* Sanity checks */
1216         BUG_ON(datasize > PAGE_SIZE ||
1217              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1218
1219         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1220         if (cqr == NULL)
1221                 return ERR_PTR(-ENOMEM);
1222         cqr->cpaddr = NULL;
1223         if (cplength > 0) {
1224                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1225                                       GFP_ATOMIC | GFP_DMA);
1226                 if (cqr->cpaddr == NULL) {
1227                         kfree(cqr);
1228                         return ERR_PTR(-ENOMEM);
1229                 }
1230         }
1231         cqr->data = NULL;
1232         if (datasize > 0) {
1233                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1234                 if (cqr->data == NULL) {
1235                         kfree(cqr->cpaddr);
1236                         kfree(cqr);
1237                         return ERR_PTR(-ENOMEM);
1238                 }
1239         }
1240         cqr->magic =  magic;
1241         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1242         dasd_get_device(device);
1243         return cqr;
1244 }
1245 EXPORT_SYMBOL(dasd_kmalloc_request);
1246
1247 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1248                                           int datasize,
1249                                           struct dasd_device *device)
1250 {
1251         unsigned long flags;
1252         struct dasd_ccw_req *cqr;
1253         char *data;
1254         int size;
1255
1256         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1257         if (cplength > 0)
1258                 size += cplength * sizeof(struct ccw1);
1259         if (datasize > 0)
1260                 size += datasize;
1261         spin_lock_irqsave(&device->mem_lock, flags);
1262         cqr = (struct dasd_ccw_req *)
1263                 dasd_alloc_chunk(&device->ccw_chunks, size);
1264         spin_unlock_irqrestore(&device->mem_lock, flags);
1265         if (cqr == NULL)
1266                 return ERR_PTR(-ENOMEM);
1267         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1268         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1269         cqr->cpaddr = NULL;
1270         if (cplength > 0) {
1271                 cqr->cpaddr = (struct ccw1 *) data;
1272                 data += cplength*sizeof(struct ccw1);
1273                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1274         }
1275         cqr->data = NULL;
1276         if (datasize > 0) {
1277                 cqr->data = data;
1278                 memset(cqr->data, 0, datasize);
1279         }
1280         cqr->magic = magic;
1281         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1282         dasd_get_device(device);
1283         return cqr;
1284 }
1285 EXPORT_SYMBOL(dasd_smalloc_request);
1286
1287 /*
1288  * Free memory of a channel program. This function needs to free all the
1289  * idal lists that might have been created by dasd_set_cda and the
1290  * struct dasd_ccw_req itself.
1291  */
1292 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1293 {
1294 #ifdef CONFIG_64BIT
1295         struct ccw1 *ccw;
1296
1297         /* Clear any idals used for the request. */
1298         ccw = cqr->cpaddr;
1299         do {
1300                 clear_normalized_cda(ccw);
1301         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1302 #endif
1303         kfree(cqr->cpaddr);
1304         kfree(cqr->data);
1305         kfree(cqr);
1306         dasd_put_device(device);
1307 }
1308 EXPORT_SYMBOL(dasd_kfree_request);
1309
1310 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1311 {
1312         unsigned long flags;
1313
1314         spin_lock_irqsave(&device->mem_lock, flags);
1315         dasd_free_chunk(&device->ccw_chunks, cqr);
1316         spin_unlock_irqrestore(&device->mem_lock, flags);
1317         dasd_put_device(device);
1318 }
1319 EXPORT_SYMBOL(dasd_sfree_request);
1320
1321 /*
1322  * Check discipline magic in cqr.
1323  */
1324 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1325 {
1326         struct dasd_device *device;
1327
1328         if (cqr == NULL)
1329                 return -EINVAL;
1330         device = cqr->startdev;
1331         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1332                 DBF_DEV_EVENT(DBF_WARNING, device,
1333                             " dasd_ccw_req 0x%08x magic doesn't match"
1334                             " discipline 0x%08x",
1335                             cqr->magic,
1336                             *(unsigned int *) device->discipline->name);
1337                 return -EINVAL;
1338         }
1339         return 0;
1340 }
1341
1342 /*
1343  * Terminate the current i/o and set the request to clear_pending.
1344  * Timer keeps device runnig.
1345  * ccw_device_clear can fail if the i/o subsystem
1346  * is in a bad mood.
1347  */
1348 int dasd_term_IO(struct dasd_ccw_req *cqr)
1349 {
1350         struct dasd_device *device;
1351         int retries, rc;
1352         char errorstring[ERRORLENGTH];
1353
1354         /* Check the cqr */
1355         rc = dasd_check_cqr(cqr);
1356         if (rc)
1357                 return rc;
1358         retries = 0;
1359         device = (struct dasd_device *) cqr->startdev;
1360         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1361                 rc = ccw_device_clear(device->cdev, (long) cqr);
1362                 switch (rc) {
1363                 case 0: /* termination successful */
1364                         cqr->status = DASD_CQR_CLEAR_PENDING;
1365                         cqr->stopclk = get_tod_clock();
1366                         cqr->starttime = 0;
1367                         DBF_DEV_EVENT(DBF_DEBUG, device,
1368                                       "terminate cqr %p successful",
1369                                       cqr);
1370                         break;
1371                 case -ENODEV:
1372                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1373                                       "device gone, retry");
1374                         break;
1375                 case -EIO:
1376                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1377                                       "I/O error, retry");
1378                         break;
1379                 case -EINVAL:
1380                 case -EBUSY:
1381                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1382                                       "device busy, retry later");
1383                         break;
1384                 default:
1385                         /* internal error 10 - unknown rc*/
1386                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1387                         dev_err(&device->cdev->dev, "An error occurred in the "
1388                                 "DASD device driver, reason=%s\n", errorstring);
1389                         BUG();
1390                         break;
1391                 }
1392                 retries++;
1393         }
1394         dasd_schedule_device_bh(device);
1395         return rc;
1396 }
1397 EXPORT_SYMBOL(dasd_term_IO);
1398
1399 /*
1400  * Start the i/o. This start_IO can fail if the channel is really busy.
1401  * In that case set up a timer to start the request later.
1402  */
1403 int dasd_start_IO(struct dasd_ccw_req *cqr)
1404 {
1405         struct dasd_device *device;
1406         int rc;
1407         char errorstring[ERRORLENGTH];
1408
1409         /* Check the cqr */
1410         rc = dasd_check_cqr(cqr);
1411         if (rc) {
1412                 cqr->intrc = rc;
1413                 return rc;
1414         }
1415         device = (struct dasd_device *) cqr->startdev;
1416         if (((cqr->block &&
1417               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1418              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1419             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1420                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1421                               "because of stolen lock", cqr);
1422                 cqr->status = DASD_CQR_ERROR;
1423                 cqr->intrc = -EPERM;
1424                 return -EPERM;
1425         }
1426         if (cqr->retries < 0) {
1427                 /* internal error 14 - start_IO run out of retries */
1428                 sprintf(errorstring, "14 %p", cqr);
1429                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1430                         "device driver, reason=%s\n", errorstring);
1431                 cqr->status = DASD_CQR_ERROR;
1432                 return -EIO;
1433         }
1434         cqr->startclk = get_tod_clock();
1435         cqr->starttime = jiffies;
1436         cqr->retries--;
1437         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1438                 cqr->lpm &= device->path_data.opm;
1439                 if (!cqr->lpm)
1440                         cqr->lpm = device->path_data.opm;
1441         }
1442         if (cqr->cpmode == 1) {
1443                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1444                                          (long) cqr, cqr->lpm);
1445         } else {
1446                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1447                                       (long) cqr, cqr->lpm, 0);
1448         }
1449         switch (rc) {
1450         case 0:
1451                 cqr->status = DASD_CQR_IN_IO;
1452                 break;
1453         case -EBUSY:
1454                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1455                               "start_IO: device busy, retry later");
1456                 break;
1457         case -ETIMEDOUT:
1458                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1459                               "start_IO: request timeout, retry later");
1460                 break;
1461         case -EACCES:
1462                 /* -EACCES indicates that the request used only a subset of the
1463                  * available paths and all these paths are gone. If the lpm of
1464                  * this request was only a subset of the opm (e.g. the ppm) then
1465                  * we just do a retry with all available paths.
1466                  * If we already use the full opm, something is amiss, and we
1467                  * need a full path verification.
1468                  */
1469                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1470                         DBF_DEV_EVENT(DBF_WARNING, device,
1471                                       "start_IO: selected paths gone (%x)",
1472                                       cqr->lpm);
1473                 } else if (cqr->lpm != device->path_data.opm) {
1474                         cqr->lpm = device->path_data.opm;
1475                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1476                                       "start_IO: selected paths gone,"
1477                                       " retry on all paths");
1478                 } else {
1479                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1480                                       "start_IO: all paths in opm gone,"
1481                                       " do path verification");
1482                         dasd_generic_last_path_gone(device);
1483                         device->path_data.opm = 0;
1484                         device->path_data.ppm = 0;
1485                         device->path_data.npm = 0;
1486                         device->path_data.tbvpm =
1487                                 ccw_device_get_path_mask(device->cdev);
1488                 }
1489                 break;
1490         case -ENODEV:
1491                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1492                               "start_IO: -ENODEV device gone, retry");
1493                 break;
1494         case -EIO:
1495                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1496                               "start_IO: -EIO device gone, retry");
1497                 break;
1498         case -EINVAL:
1499                 /* most likely caused in power management context */
1500                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1501                               "start_IO: -EINVAL device currently "
1502                               "not accessible");
1503                 break;
1504         default:
1505                 /* internal error 11 - unknown rc */
1506                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1507                 dev_err(&device->cdev->dev,
1508                         "An error occurred in the DASD device driver, "
1509                         "reason=%s\n", errorstring);
1510                 BUG();
1511                 break;
1512         }
1513         cqr->intrc = rc;
1514         return rc;
1515 }
1516 EXPORT_SYMBOL(dasd_start_IO);
1517
1518 /*
1519  * Timeout function for dasd devices. This is used for different purposes
1520  *  1) missing interrupt handler for normal operation
1521  *  2) delayed start of request where start_IO failed with -EBUSY
1522  *  3) timeout for missing state change interrupts
1523  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1524  * DASD_CQR_QUEUED for 2) and 3).
1525  */
1526 static void dasd_device_timeout(unsigned long ptr)
1527 {
1528         unsigned long flags;
1529         struct dasd_device *device;
1530
1531         device = (struct dasd_device *) ptr;
1532         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1533         /* re-activate request queue */
1534         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1535         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1536         dasd_schedule_device_bh(device);
1537 }
1538
1539 /*
1540  * Setup timeout for a device in jiffies.
1541  */
1542 void dasd_device_set_timer(struct dasd_device *device, int expires)
1543 {
1544         if (expires == 0)
1545                 del_timer(&device->timer);
1546         else
1547                 mod_timer(&device->timer, jiffies + expires);
1548 }
1549 EXPORT_SYMBOL(dasd_device_set_timer);
1550
1551 /*
1552  * Clear timeout for a device.
1553  */
1554 void dasd_device_clear_timer(struct dasd_device *device)
1555 {
1556         del_timer(&device->timer);
1557 }
1558 EXPORT_SYMBOL(dasd_device_clear_timer);
1559
1560 static void dasd_handle_killed_request(struct ccw_device *cdev,
1561                                        unsigned long intparm)
1562 {
1563         struct dasd_ccw_req *cqr;
1564         struct dasd_device *device;
1565
1566         if (!intparm)
1567                 return;
1568         cqr = (struct dasd_ccw_req *) intparm;
1569         if (cqr->status != DASD_CQR_IN_IO) {
1570                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1571                                 "invalid status in handle_killed_request: "
1572                                 "%02x", cqr->status);
1573                 return;
1574         }
1575
1576         device = dasd_device_from_cdev_locked(cdev);
1577         if (IS_ERR(device)) {
1578                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1579                                 "unable to get device from cdev");
1580                 return;
1581         }
1582
1583         if (!cqr->startdev ||
1584             device != cqr->startdev ||
1585             strncmp(cqr->startdev->discipline->ebcname,
1586                     (char *) &cqr->magic, 4)) {
1587                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1588                                 "invalid device in request");
1589                 dasd_put_device(device);
1590                 return;
1591         }
1592
1593         /* Schedule request to be retried. */
1594         cqr->status = DASD_CQR_QUEUED;
1595
1596         dasd_device_clear_timer(device);
1597         dasd_schedule_device_bh(device);
1598         dasd_put_device(device);
1599 }
1600
1601 void dasd_generic_handle_state_change(struct dasd_device *device)
1602 {
1603         /* First of all start sense subsystem status request. */
1604         dasd_eer_snss(device);
1605
1606         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1607         dasd_schedule_device_bh(device);
1608         if (device->block)
1609                 dasd_schedule_block_bh(device->block);
1610 }
1611 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1612
1613 /*
1614  * Interrupt handler for "normal" ssch-io based dasd devices.
1615  */
1616 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1617                       struct irb *irb)
1618 {
1619         struct dasd_ccw_req *cqr, *next;
1620         struct dasd_device *device;
1621         unsigned long long now;
1622         int expires;
1623
1624         if (IS_ERR(irb)) {
1625                 switch (PTR_ERR(irb)) {
1626                 case -EIO:
1627                         break;
1628                 case -ETIMEDOUT:
1629                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1630                                         "request timed out\n", __func__);
1631                         break;
1632                 default:
1633                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1634                                         "unknown error %ld\n", __func__,
1635                                         PTR_ERR(irb));
1636                 }
1637                 dasd_handle_killed_request(cdev, intparm);
1638                 return;
1639         }
1640
1641         now = get_tod_clock();
1642         cqr = (struct dasd_ccw_req *) intparm;
1643         /* check for conditions that should be handled immediately */
1644         if (!cqr ||
1645             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1646               scsw_cstat(&irb->scsw) == 0)) {
1647                 if (cqr)
1648                         memcpy(&cqr->irb, irb, sizeof(*irb));
1649                 device = dasd_device_from_cdev_locked(cdev);
1650                 if (IS_ERR(device))
1651                         return;
1652                 /* ignore unsolicited interrupts for DIAG discipline */
1653                 if (device->discipline == dasd_diag_discipline_pointer) {
1654                         dasd_put_device(device);
1655                         return;
1656                 }
1657                 device->discipline->dump_sense_dbf(device, irb, "int");
1658                 if (device->features & DASD_FEATURE_ERPLOG)
1659                         device->discipline->dump_sense(device, cqr, irb);
1660                 device->discipline->check_for_device_change(device, cqr, irb);
1661                 dasd_put_device(device);
1662         }
1663         if (!cqr)
1664                 return;
1665
1666         device = (struct dasd_device *) cqr->startdev;
1667         if (!device ||
1668             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1669                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1670                                 "invalid device in request");
1671                 return;
1672         }
1673
1674         /* Check for clear pending */
1675         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1676             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1677                 cqr->status = DASD_CQR_CLEARED;
1678                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
1679                         cqr->callback_data = DASD_SLEEPON_END_TAG;
1680                 dasd_device_clear_timer(device);
1681                 wake_up(&dasd_flush_wq);
1682                 wake_up(&generic_waitq);
1683                 dasd_schedule_device_bh(device);
1684                 return;
1685         }
1686
1687         /* check status - the request might have been killed by dyn detach */
1688         if (cqr->status != DASD_CQR_IN_IO) {
1689                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1690                               "status %02x", dev_name(&cdev->dev), cqr->status);
1691                 return;
1692         }
1693
1694         next = NULL;
1695         expires = 0;
1696         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1697             scsw_cstat(&irb->scsw) == 0) {
1698                 /* request was completed successfully */
1699                 cqr->status = DASD_CQR_SUCCESS;
1700                 cqr->stopclk = now;
1701                 /* Start first request on queue if possible -> fast_io. */
1702                 if (cqr->devlist.next != &device->ccw_queue) {
1703                         next = list_entry(cqr->devlist.next,
1704                                           struct dasd_ccw_req, devlist);
1705                 }
1706         } else {  /* error */
1707                 /*
1708                  * If we don't want complex ERP for this request, then just
1709                  * reset this and retry it in the fastpath
1710                  */
1711                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1712                     cqr->retries > 0) {
1713                         if (cqr->lpm == device->path_data.opm)
1714                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1715                                               "default ERP in fastpath "
1716                                               "(%i retries left)",
1717                                               cqr->retries);
1718                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1719                                 cqr->lpm = device->path_data.opm;
1720                         cqr->status = DASD_CQR_QUEUED;
1721                         next = cqr;
1722                 } else
1723                         cqr->status = DASD_CQR_ERROR;
1724         }
1725         if (next && (next->status == DASD_CQR_QUEUED) &&
1726             (!device->stopped)) {
1727                 if (device->discipline->start_IO(next) == 0)
1728                         expires = next->expires;
1729         }
1730         if (expires != 0)
1731                 dasd_device_set_timer(device, expires);
1732         else
1733                 dasd_device_clear_timer(device);
1734         dasd_schedule_device_bh(device);
1735 }
1736 EXPORT_SYMBOL(dasd_int_handler);
1737
1738 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1739 {
1740         struct dasd_device *device;
1741
1742         device = dasd_device_from_cdev_locked(cdev);
1743
1744         if (IS_ERR(device))
1745                 goto out;
1746         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1747            device->state != device->target ||
1748            !device->discipline->check_for_device_change){
1749                 dasd_put_device(device);
1750                 goto out;
1751         }
1752         if (device->discipline->dump_sense_dbf)
1753                 device->discipline->dump_sense_dbf(device, irb, "uc");
1754         device->discipline->check_for_device_change(device, NULL, irb);
1755         dasd_put_device(device);
1756 out:
1757         return UC_TODO_RETRY;
1758 }
1759 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1760
1761 /*
1762  * If we have an error on a dasd_block layer request then we cancel
1763  * and return all further requests from the same dasd_block as well.
1764  */
1765 static void __dasd_device_recovery(struct dasd_device *device,
1766                                    struct dasd_ccw_req *ref_cqr)
1767 {
1768         struct list_head *l, *n;
1769         struct dasd_ccw_req *cqr;
1770
1771         /*
1772          * only requeue request that came from the dasd_block layer
1773          */
1774         if (!ref_cqr->block)
1775                 return;
1776
1777         list_for_each_safe(l, n, &device->ccw_queue) {
1778                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1779                 if (cqr->status == DASD_CQR_QUEUED &&
1780                     ref_cqr->block == cqr->block) {
1781                         cqr->status = DASD_CQR_CLEARED;
1782                 }
1783         }
1784 };
1785
1786 /*
1787  * Remove those ccw requests from the queue that need to be returned
1788  * to the upper layer.
1789  */
1790 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1791                                             struct list_head *final_queue)
1792 {
1793         struct list_head *l, *n;
1794         struct dasd_ccw_req *cqr;
1795
1796         /* Process request with final status. */
1797         list_for_each_safe(l, n, &device->ccw_queue) {
1798                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1799
1800                 /* Skip any non-final request. */
1801                 if (cqr->status == DASD_CQR_QUEUED ||
1802                     cqr->status == DASD_CQR_IN_IO ||
1803                     cqr->status == DASD_CQR_CLEAR_PENDING)
1804                         continue;
1805                 if (cqr->status == DASD_CQR_ERROR) {
1806                         __dasd_device_recovery(device, cqr);
1807                 }
1808                 /* Rechain finished requests to final queue */
1809                 list_move_tail(&cqr->devlist, final_queue);
1810         }
1811 }
1812
1813 /*
1814  * the cqrs from the final queue are returned to the upper layer
1815  * by setting a dasd_block state and calling the callback function
1816  */
1817 static void __dasd_device_process_final_queue(struct dasd_device *device,
1818                                               struct list_head *final_queue)
1819 {
1820         struct list_head *l, *n;
1821         struct dasd_ccw_req *cqr;
1822         struct dasd_block *block;
1823         void (*callback)(struct dasd_ccw_req *, void *data);
1824         void *callback_data;
1825         char errorstring[ERRORLENGTH];
1826
1827         list_for_each_safe(l, n, final_queue) {
1828                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1829                 list_del_init(&cqr->devlist);
1830                 block = cqr->block;
1831                 callback = cqr->callback;
1832                 callback_data = cqr->callback_data;
1833                 if (block)
1834                         spin_lock_bh(&block->queue_lock);
1835                 switch (cqr->status) {
1836                 case DASD_CQR_SUCCESS:
1837                         cqr->status = DASD_CQR_DONE;
1838                         break;
1839                 case DASD_CQR_ERROR:
1840                         cqr->status = DASD_CQR_NEED_ERP;
1841                         break;
1842                 case DASD_CQR_CLEARED:
1843                         cqr->status = DASD_CQR_TERMINATED;
1844                         break;
1845                 default:
1846                         /* internal error 12 - wrong cqr status*/
1847                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1848                         dev_err(&device->cdev->dev,
1849                                 "An error occurred in the DASD device driver, "
1850                                 "reason=%s\n", errorstring);
1851                         BUG();
1852                 }
1853                 if (cqr->callback != NULL)
1854                         (callback)(cqr, callback_data);
1855                 if (block)
1856                         spin_unlock_bh(&block->queue_lock);
1857         }
1858 }
1859
1860 /*
1861  * Take a look at the first request on the ccw queue and check
1862  * if it reached its expire time. If so, terminate the IO.
1863  */
1864 static void __dasd_device_check_expire(struct dasd_device *device)
1865 {
1866         struct dasd_ccw_req *cqr;
1867
1868         if (list_empty(&device->ccw_queue))
1869                 return;
1870         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1871         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1872             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1873                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1874                         /*
1875                          * IO in safe offline processing should not
1876                          * run out of retries
1877                          */
1878                         cqr->retries++;
1879                 }
1880                 if (device->discipline->term_IO(cqr) != 0) {
1881                         /* Hmpf, try again in 5 sec */
1882                         dev_err(&device->cdev->dev,
1883                                 "cqr %p timed out (%lus) but cannot be "
1884                                 "ended, retrying in 5 s\n",
1885                                 cqr, (cqr->expires/HZ));
1886                         cqr->expires += 5*HZ;
1887                         dasd_device_set_timer(device, 5*HZ);
1888                 } else {
1889                         dev_err(&device->cdev->dev,
1890                                 "cqr %p timed out (%lus), %i retries "
1891                                 "remaining\n", cqr, (cqr->expires/HZ),
1892                                 cqr->retries);
1893                 }
1894         }
1895 }
1896
1897 /*
1898  * Take a look at the first request on the ccw queue and check
1899  * if it needs to be started.
1900  */
1901 static void __dasd_device_start_head(struct dasd_device *device)
1902 {
1903         struct dasd_ccw_req *cqr;
1904         int rc;
1905
1906         if (list_empty(&device->ccw_queue))
1907                 return;
1908         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1909         if (cqr->status != DASD_CQR_QUEUED)
1910                 return;
1911         /* when device is stopped, return request to previous layer
1912          * exception: only the disconnect or unresumed bits are set and the
1913          * cqr is a path verification request
1914          */
1915         if (device->stopped &&
1916             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1917               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1918                 cqr->intrc = -EAGAIN;
1919                 cqr->status = DASD_CQR_CLEARED;
1920                 dasd_schedule_device_bh(device);
1921                 return;
1922         }
1923
1924         rc = device->discipline->start_IO(cqr);
1925         if (rc == 0)
1926                 dasd_device_set_timer(device, cqr->expires);
1927         else if (rc == -EACCES) {
1928                 dasd_schedule_device_bh(device);
1929         } else
1930                 /* Hmpf, try again in 1/2 sec */
1931                 dasd_device_set_timer(device, 50);
1932 }
1933
1934 static void __dasd_device_check_path_events(struct dasd_device *device)
1935 {
1936         int rc;
1937
1938         if (device->path_data.tbvpm) {
1939                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1940                                         DASD_UNRESUMED_PM))
1941                         return;
1942                 rc = device->discipline->verify_path(
1943                         device, device->path_data.tbvpm);
1944                 if (rc)
1945                         dasd_device_set_timer(device, 50);
1946                 else
1947                         device->path_data.tbvpm = 0;
1948         }
1949 };
1950
1951 /*
1952  * Go through all request on the dasd_device request queue,
1953  * terminate them on the cdev if necessary, and return them to the
1954  * submitting layer via callback.
1955  * Note:
1956  * Make sure that all 'submitting layers' still exist when
1957  * this function is called!. In other words, when 'device' is a base
1958  * device then all block layer requests must have been removed before
1959  * via dasd_flush_block_queue.
1960  */
1961 int dasd_flush_device_queue(struct dasd_device *device)
1962 {
1963         struct dasd_ccw_req *cqr, *n;
1964         int rc;
1965         struct list_head flush_queue;
1966
1967         INIT_LIST_HEAD(&flush_queue);
1968         spin_lock_irq(get_ccwdev_lock(device->cdev));
1969         rc = 0;
1970         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1971                 /* Check status and move request to flush_queue */
1972                 switch (cqr->status) {
1973                 case DASD_CQR_IN_IO:
1974                         rc = device->discipline->term_IO(cqr);
1975                         if (rc) {
1976                                 /* unable to terminate requeust */
1977                                 dev_err(&device->cdev->dev,
1978                                         "Flushing the DASD request queue "
1979                                         "failed for request %p\n", cqr);
1980                                 /* stop flush processing */
1981                                 goto finished;
1982                         }
1983                         break;
1984                 case DASD_CQR_QUEUED:
1985                         cqr->stopclk = get_tod_clock();
1986                         cqr->status = DASD_CQR_CLEARED;
1987                         break;
1988                 default: /* no need to modify the others */
1989                         break;
1990                 }
1991                 list_move_tail(&cqr->devlist, &flush_queue);
1992         }
1993 finished:
1994         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1995         /*
1996          * After this point all requests must be in state CLEAR_PENDING,
1997          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1998          * one of the others.
1999          */
2000         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2001                 wait_event(dasd_flush_wq,
2002                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2003         /*
2004          * Now set each request back to TERMINATED, DONE or NEED_ERP
2005          * and call the callback function of flushed requests
2006          */
2007         __dasd_device_process_final_queue(device, &flush_queue);
2008         return rc;
2009 }
2010 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2011
2012 /*
2013  * Acquire the device lock and process queues for the device.
2014  */
2015 static void dasd_device_tasklet(struct dasd_device *device)
2016 {
2017         struct list_head final_queue;
2018
2019         atomic_set (&device->tasklet_scheduled, 0);
2020         INIT_LIST_HEAD(&final_queue);
2021         spin_lock_irq(get_ccwdev_lock(device->cdev));
2022         /* Check expire time of first request on the ccw queue. */
2023         __dasd_device_check_expire(device);
2024         /* find final requests on ccw queue */
2025         __dasd_device_process_ccw_queue(device, &final_queue);
2026         __dasd_device_check_path_events(device);
2027         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2028         /* Now call the callback function of requests with final status */
2029         __dasd_device_process_final_queue(device, &final_queue);
2030         spin_lock_irq(get_ccwdev_lock(device->cdev));
2031         /* Now check if the head of the ccw queue needs to be started. */
2032         __dasd_device_start_head(device);
2033         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2034         if (waitqueue_active(&shutdown_waitq))
2035                 wake_up(&shutdown_waitq);
2036         dasd_put_device(device);
2037 }
2038
2039 /*
2040  * Schedules a call to dasd_tasklet over the device tasklet.
2041  */
2042 void dasd_schedule_device_bh(struct dasd_device *device)
2043 {
2044         /* Protect against rescheduling. */
2045         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2046                 return;
2047         dasd_get_device(device);
2048         tasklet_hi_schedule(&device->tasklet);
2049 }
2050 EXPORT_SYMBOL(dasd_schedule_device_bh);
2051
2052 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2053 {
2054         device->stopped |= bits;
2055 }
2056 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2057
2058 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2059 {
2060         device->stopped &= ~bits;
2061         if (!device->stopped)
2062                 wake_up(&generic_waitq);
2063 }
2064 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2065
2066 /*
2067  * Queue a request to the head of the device ccw_queue.
2068  * Start the I/O if possible.
2069  */
2070 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2071 {
2072         struct dasd_device *device;
2073         unsigned long flags;
2074
2075         device = cqr->startdev;
2076         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2077         cqr->status = DASD_CQR_QUEUED;
2078         list_add(&cqr->devlist, &device->ccw_queue);
2079         /* let the bh start the request to keep them in order */
2080         dasd_schedule_device_bh(device);
2081         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2082 }
2083 EXPORT_SYMBOL(dasd_add_request_head);
2084
2085 /*
2086  * Queue a request to the tail of the device ccw_queue.
2087  * Start the I/O if possible.
2088  */
2089 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2090 {
2091         struct dasd_device *device;
2092         unsigned long flags;
2093
2094         device = cqr->startdev;
2095         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2096         cqr->status = DASD_CQR_QUEUED;
2097         list_add_tail(&cqr->devlist, &device->ccw_queue);
2098         /* let the bh start the request to keep them in order */
2099         dasd_schedule_device_bh(device);
2100         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2101 }
2102 EXPORT_SYMBOL(dasd_add_request_tail);
2103
2104 /*
2105  * Wakeup helper for the 'sleep_on' functions.
2106  */
2107 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2108 {
2109         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2110         cqr->callback_data = DASD_SLEEPON_END_TAG;
2111         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2112         wake_up(&generic_waitq);
2113 }
2114 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2115
2116 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2117 {
2118         struct dasd_device *device;
2119         int rc;
2120
2121         device = cqr->startdev;
2122         spin_lock_irq(get_ccwdev_lock(device->cdev));
2123         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2124         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2125         return rc;
2126 }
2127
2128 /*
2129  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2130  */
2131 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2132 {
2133         struct dasd_device *device;
2134         dasd_erp_fn_t erp_fn;
2135
2136         if (cqr->status == DASD_CQR_FILLED)
2137                 return 0;
2138         device = cqr->startdev;
2139         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2140                 if (cqr->status == DASD_CQR_TERMINATED) {
2141                         device->discipline->handle_terminated_request(cqr);
2142                         return 1;
2143                 }
2144                 if (cqr->status == DASD_CQR_NEED_ERP) {
2145                         erp_fn = device->discipline->erp_action(cqr);
2146                         erp_fn(cqr);
2147                         return 1;
2148                 }
2149                 if (cqr->status == DASD_CQR_FAILED)
2150                         dasd_log_sense(cqr, &cqr->irb);
2151                 if (cqr->refers) {
2152                         __dasd_process_erp(device, cqr);
2153                         return 1;
2154                 }
2155         }
2156         return 0;
2157 }
2158
2159 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2160 {
2161         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2162                 if (cqr->refers) /* erp is not done yet */
2163                         return 1;
2164                 return ((cqr->status != DASD_CQR_DONE) &&
2165                         (cqr->status != DASD_CQR_FAILED));
2166         } else
2167                 return (cqr->status == DASD_CQR_FILLED);
2168 }
2169
2170 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2171 {
2172         struct dasd_device *device;
2173         int rc;
2174         struct list_head ccw_queue;
2175         struct dasd_ccw_req *cqr;
2176
2177         INIT_LIST_HEAD(&ccw_queue);
2178         maincqr->status = DASD_CQR_FILLED;
2179         device = maincqr->startdev;
2180         list_add(&maincqr->blocklist, &ccw_queue);
2181         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2182              cqr = list_first_entry(&ccw_queue,
2183                                     struct dasd_ccw_req, blocklist)) {
2184
2185                 if (__dasd_sleep_on_erp(cqr))
2186                         continue;
2187                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2188                         continue;
2189                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2190                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2191                         cqr->status = DASD_CQR_FAILED;
2192                         cqr->intrc = -EPERM;
2193                         continue;
2194                 }
2195                 /* Non-temporary stop condition will trigger fail fast */
2196                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2197                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2198                     (!dasd_eer_enabled(device))) {
2199                         cqr->status = DASD_CQR_FAILED;
2200                         cqr->intrc = -ENOLINK;
2201                         continue;
2202                 }
2203                 /* Don't try to start requests if device is stopped */
2204                 if (interruptible) {
2205                         rc = wait_event_interruptible(
2206                                 generic_waitq, !(device->stopped));
2207                         if (rc == -ERESTARTSYS) {
2208                                 cqr->status = DASD_CQR_FAILED;
2209                                 maincqr->intrc = rc;
2210                                 continue;
2211                         }
2212                 } else
2213                         wait_event(generic_waitq, !(device->stopped));
2214
2215                 if (!cqr->callback)
2216                         cqr->callback = dasd_wakeup_cb;
2217
2218                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2219                 dasd_add_request_tail(cqr);
2220                 if (interruptible) {
2221                         rc = wait_event_interruptible(
2222                                 generic_waitq, _wait_for_wakeup(cqr));
2223                         if (rc == -ERESTARTSYS) {
2224                                 dasd_cancel_req(cqr);
2225                                 /* wait (non-interruptible) for final status */
2226                                 wait_event(generic_waitq,
2227                                            _wait_for_wakeup(cqr));
2228                                 cqr->status = DASD_CQR_FAILED;
2229                                 maincqr->intrc = rc;
2230                                 continue;
2231                         }
2232                 } else
2233                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2234         }
2235
2236         maincqr->endclk = get_tod_clock();
2237         if ((maincqr->status != DASD_CQR_DONE) &&
2238             (maincqr->intrc != -ERESTARTSYS))
2239                 dasd_log_sense(maincqr, &maincqr->irb);
2240         if (maincqr->status == DASD_CQR_DONE)
2241                 rc = 0;
2242         else if (maincqr->intrc)
2243                 rc = maincqr->intrc;
2244         else
2245                 rc = -EIO;
2246         return rc;
2247 }
2248
2249 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2250 {
2251         struct dasd_ccw_req *cqr;
2252
2253         list_for_each_entry(cqr, ccw_queue, blocklist) {
2254                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2255                         return 0;
2256         }
2257
2258         return 1;
2259 }
2260
2261 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2262 {
2263         struct dasd_device *device;
2264         int rc;
2265         struct dasd_ccw_req *cqr, *n;
2266
2267 retry:
2268         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2269                 device = cqr->startdev;
2270                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2271                         continue;
2272
2273                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2274                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2275                         cqr->status = DASD_CQR_FAILED;
2276                         cqr->intrc = -EPERM;
2277                         continue;
2278                 }
2279                 /*Non-temporary stop condition will trigger fail fast*/
2280                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2281                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2282                     !dasd_eer_enabled(device)) {
2283                         cqr->status = DASD_CQR_FAILED;
2284                         cqr->intrc = -EAGAIN;
2285                         continue;
2286                 }
2287
2288                 /*Don't try to start requests if device is stopped*/
2289                 if (interruptible) {
2290                         rc = wait_event_interruptible(
2291                                 generic_waitq, !device->stopped);
2292                         if (rc == -ERESTARTSYS) {
2293                                 cqr->status = DASD_CQR_FAILED;
2294                                 cqr->intrc = rc;
2295                                 continue;
2296                         }
2297                 } else
2298                         wait_event(generic_waitq, !(device->stopped));
2299
2300                 if (!cqr->callback)
2301                         cqr->callback = dasd_wakeup_cb;
2302                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2303                 dasd_add_request_tail(cqr);
2304         }
2305
2306         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2307
2308         rc = 0;
2309         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2310                 /*
2311                  * for alias devices simplify error recovery and
2312                  * return to upper layer
2313                  */
2314                 if (cqr->startdev != cqr->basedev &&
2315                     (cqr->status == DASD_CQR_TERMINATED ||
2316                      cqr->status == DASD_CQR_NEED_ERP))
2317                         return -EAGAIN;
2318                 else {
2319                         /* normal recovery for basedev IO */
2320                         if (__dasd_sleep_on_erp(cqr)) {
2321                                 if (!cqr->status == DASD_CQR_TERMINATED &&
2322                                     !cqr->status == DASD_CQR_NEED_ERP)
2323                                         break;
2324                                 rc = 1;
2325                         }
2326                 }
2327         }
2328         if (rc)
2329                 goto retry;
2330
2331         return 0;
2332 }
2333
2334 /*
2335  * Queue a request to the tail of the device ccw_queue and wait for
2336  * it's completion.
2337  */
2338 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2339 {
2340         return _dasd_sleep_on(cqr, 0);
2341 }
2342 EXPORT_SYMBOL(dasd_sleep_on);
2343
2344 /*
2345  * Start requests from a ccw_queue and wait for their completion.
2346  */
2347 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2348 {
2349         return _dasd_sleep_on_queue(ccw_queue, 0);
2350 }
2351 EXPORT_SYMBOL(dasd_sleep_on_queue);
2352
2353 /*
2354  * Queue a request to the tail of the device ccw_queue and wait
2355  * interruptible for it's completion.
2356  */
2357 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2358 {
2359         return _dasd_sleep_on(cqr, 1);
2360 }
2361 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2362
2363 /*
2364  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2365  * for eckd devices) the currently running request has to be terminated
2366  * and be put back to status queued, before the special request is added
2367  * to the head of the queue. Then the special request is waited on normally.
2368  */
2369 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2370 {
2371         struct dasd_ccw_req *cqr;
2372         int rc;
2373
2374         if (list_empty(&device->ccw_queue))
2375                 return 0;
2376         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2377         rc = device->discipline->term_IO(cqr);
2378         if (!rc)
2379                 /*
2380                  * CQR terminated because a more important request is pending.
2381                  * Undo decreasing of retry counter because this is
2382                  * not an error case.
2383                  */
2384                 cqr->retries++;
2385         return rc;
2386 }
2387
2388 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2389 {
2390         struct dasd_device *device;
2391         int rc;
2392
2393         device = cqr->startdev;
2394         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2395             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2396                 cqr->status = DASD_CQR_FAILED;
2397                 cqr->intrc = -EPERM;
2398                 return -EIO;
2399         }
2400         spin_lock_irq(get_ccwdev_lock(device->cdev));
2401         rc = _dasd_term_running_cqr(device);
2402         if (rc) {
2403                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2404                 return rc;
2405         }
2406         cqr->callback = dasd_wakeup_cb;
2407         cqr->callback_data = DASD_SLEEPON_START_TAG;
2408         cqr->status = DASD_CQR_QUEUED;
2409         /*
2410          * add new request as second
2411          * first the terminated cqr needs to be finished
2412          */
2413         list_add(&cqr->devlist, device->ccw_queue.next);
2414
2415         /* let the bh start the request to keep them in order */
2416         dasd_schedule_device_bh(device);
2417
2418         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2419
2420         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2421
2422         if (cqr->status == DASD_CQR_DONE)
2423                 rc = 0;
2424         else if (cqr->intrc)
2425                 rc = cqr->intrc;
2426         else
2427                 rc = -EIO;
2428
2429         /* kick tasklets */
2430         dasd_schedule_device_bh(device);
2431         if (device->block)
2432                 dasd_schedule_block_bh(device->block);
2433
2434         return rc;
2435 }
2436 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2437
2438 /*
2439  * Cancels a request that was started with dasd_sleep_on_req.
2440  * This is useful to timeout requests. The request will be
2441  * terminated if it is currently in i/o.
2442  * Returns 0 if request termination was successful
2443  *         negative error code if termination failed
2444  * Cancellation of a request is an asynchronous operation! The calling
2445  * function has to wait until the request is properly returned via callback.
2446  */
2447 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2448 {
2449         struct dasd_device *device = cqr->startdev;
2450         unsigned long flags;
2451         int rc;
2452
2453         rc = 0;
2454         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2455         switch (cqr->status) {
2456         case DASD_CQR_QUEUED:
2457                 /* request was not started - just set to cleared */
2458                 cqr->status = DASD_CQR_CLEARED;
2459                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2460                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2461                 break;
2462         case DASD_CQR_IN_IO:
2463                 /* request in IO - terminate IO and release again */
2464                 rc = device->discipline->term_IO(cqr);
2465                 if (rc) {
2466                         dev_err(&device->cdev->dev,
2467                                 "Cancelling request %p failed with rc=%d\n",
2468                                 cqr, rc);
2469                 } else {
2470                         cqr->stopclk = get_tod_clock();
2471                 }
2472                 break;
2473         default: /* already finished or clear pending - do nothing */
2474                 break;
2475         }
2476         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2477         dasd_schedule_device_bh(device);
2478         return rc;
2479 }
2480 EXPORT_SYMBOL(dasd_cancel_req);
2481
2482 /*
2483  * SECTION: Operations of the dasd_block layer.
2484  */
2485
2486 /*
2487  * Timeout function for dasd_block. This is used when the block layer
2488  * is waiting for something that may not come reliably, (e.g. a state
2489  * change interrupt)
2490  */
2491 static void dasd_block_timeout(unsigned long ptr)
2492 {
2493         unsigned long flags;
2494         struct dasd_block *block;
2495
2496         block = (struct dasd_block *) ptr;
2497         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2498         /* re-activate request queue */
2499         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2500         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2501         dasd_schedule_block_bh(block);
2502 }
2503
2504 /*
2505  * Setup timeout for a dasd_block in jiffies.
2506  */
2507 void dasd_block_set_timer(struct dasd_block *block, int expires)
2508 {
2509         if (expires == 0)
2510                 del_timer(&block->timer);
2511         else
2512                 mod_timer(&block->timer, jiffies + expires);
2513 }
2514 EXPORT_SYMBOL(dasd_block_set_timer);
2515
2516 /*
2517  * Clear timeout for a dasd_block.
2518  */
2519 void dasd_block_clear_timer(struct dasd_block *block)
2520 {
2521         del_timer(&block->timer);
2522 }
2523 EXPORT_SYMBOL(dasd_block_clear_timer);
2524
2525 /*
2526  * Process finished error recovery ccw.
2527  */
2528 static void __dasd_process_erp(struct dasd_device *device,
2529                                struct dasd_ccw_req *cqr)
2530 {
2531         dasd_erp_fn_t erp_fn;
2532
2533         if (cqr->status == DASD_CQR_DONE)
2534                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2535         else
2536                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2537         erp_fn = device->discipline->erp_postaction(cqr);
2538         erp_fn(cqr);
2539 }
2540
2541 /*
2542  * Fetch requests from the block device queue.
2543  */
2544 static void __dasd_process_request_queue(struct dasd_block *block)
2545 {
2546         struct request_queue *queue;
2547         struct request *req;
2548         struct dasd_ccw_req *cqr;
2549         struct dasd_device *basedev;
2550         unsigned long flags;
2551         queue = block->request_queue;
2552         basedev = block->base;
2553         /* No queue ? Then there is nothing to do. */
2554         if (queue == NULL)
2555                 return;
2556
2557         /*
2558          * We requeue request from the block device queue to the ccw
2559          * queue only in two states. In state DASD_STATE_READY the
2560          * partition detection is done and we need to requeue requests
2561          * for that. State DASD_STATE_ONLINE is normal block device
2562          * operation.
2563          */
2564         if (basedev->state < DASD_STATE_READY) {
2565                 while ((req = blk_fetch_request(block->request_queue)))
2566                         __blk_end_request_all(req, -EIO);
2567                 return;
2568         }
2569         /* Now we try to fetch requests from the request queue */
2570         while ((req = blk_peek_request(queue))) {
2571                 if (basedev->features & DASD_FEATURE_READONLY &&
2572                     rq_data_dir(req) == WRITE) {
2573                         DBF_DEV_EVENT(DBF_ERR, basedev,
2574                                       "Rejecting write request %p",
2575                                       req);
2576                         blk_start_request(req);
2577                         __blk_end_request_all(req, -EIO);
2578                         continue;
2579                 }
2580                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2581                     (basedev->features & DASD_FEATURE_FAILFAST ||
2582                      blk_noretry_request(req))) {
2583                         DBF_DEV_EVENT(DBF_ERR, basedev,
2584                                       "Rejecting failfast request %p",
2585                                       req);
2586                         blk_start_request(req);
2587                         __blk_end_request_all(req, -ETIMEDOUT);
2588                         continue;
2589                 }
2590                 cqr = basedev->discipline->build_cp(basedev, block, req);
2591                 if (IS_ERR(cqr)) {
2592                         if (PTR_ERR(cqr) == -EBUSY)
2593                                 break;  /* normal end condition */
2594                         if (PTR_ERR(cqr) == -ENOMEM)
2595                                 break;  /* terminate request queue loop */
2596                         if (PTR_ERR(cqr) == -EAGAIN) {
2597                                 /*
2598                                  * The current request cannot be build right
2599                                  * now, we have to try later. If this request
2600                                  * is the head-of-queue we stop the device
2601                                  * for 1/2 second.
2602                                  */
2603                                 if (!list_empty(&block->ccw_queue))
2604                                         break;
2605                                 spin_lock_irqsave(
2606                                         get_ccwdev_lock(basedev->cdev), flags);
2607                                 dasd_device_set_stop_bits(basedev,
2608                                                           DASD_STOPPED_PENDING);
2609                                 spin_unlock_irqrestore(
2610                                         get_ccwdev_lock(basedev->cdev), flags);
2611                                 dasd_block_set_timer(block, HZ/2);
2612                                 break;
2613                         }
2614                         DBF_DEV_EVENT(DBF_ERR, basedev,
2615                                       "CCW creation failed (rc=%ld) "
2616                                       "on request %p",
2617                                       PTR_ERR(cqr), req);
2618                         blk_start_request(req);
2619                         __blk_end_request_all(req, -EIO);
2620                         continue;
2621                 }
2622                 /*
2623                  *  Note: callback is set to dasd_return_cqr_cb in
2624                  * __dasd_block_start_head to cover erp requests as well
2625                  */
2626                 cqr->callback_data = (void *) req;
2627                 cqr->status = DASD_CQR_FILLED;
2628                 req->completion_data = cqr;
2629                 blk_start_request(req);
2630                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2631                 INIT_LIST_HEAD(&cqr->devlist);
2632                 dasd_profile_start(block, cqr, req);
2633         }
2634 }
2635
2636 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2637 {
2638         struct request *req;
2639         int status;
2640         int error = 0;
2641
2642         req = (struct request *) cqr->callback_data;
2643         dasd_profile_end(cqr->block, cqr, req);
2644         status = cqr->block->base->discipline->free_cp(cqr, req);
2645         if (status < 0)
2646                 error = status;
2647         else if (status == 0) {
2648                 if (cqr->intrc == -EPERM)
2649                         error = -EBADE;
2650                 else if (cqr->intrc == -ENOLINK ||
2651                          cqr->intrc == -ETIMEDOUT)
2652                         error = cqr->intrc;
2653                 else
2654                         error = -EIO;
2655         }
2656         __blk_end_request_all(req, error);
2657 }
2658
2659 /*
2660  * Process ccw request queue.
2661  */
2662 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2663                                            struct list_head *final_queue)
2664 {
2665         struct list_head *l, *n;
2666         struct dasd_ccw_req *cqr;
2667         dasd_erp_fn_t erp_fn;
2668         unsigned long flags;
2669         struct dasd_device *base = block->base;
2670
2671 restart:
2672         /* Process request with final status. */
2673         list_for_each_safe(l, n, &block->ccw_queue) {
2674                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2675                 if (cqr->status != DASD_CQR_DONE &&
2676                     cqr->status != DASD_CQR_FAILED &&
2677                     cqr->status != DASD_CQR_NEED_ERP &&
2678                     cqr->status != DASD_CQR_TERMINATED)
2679                         continue;
2680
2681                 if (cqr->status == DASD_CQR_TERMINATED) {
2682                         base->discipline->handle_terminated_request(cqr);
2683                         goto restart;
2684                 }
2685
2686                 /*  Process requests that may be recovered */
2687                 if (cqr->status == DASD_CQR_NEED_ERP) {
2688                         erp_fn = base->discipline->erp_action(cqr);
2689                         if (IS_ERR(erp_fn(cqr)))
2690                                 continue;
2691                         goto restart;
2692                 }
2693
2694                 /* log sense for fatal error */
2695                 if (cqr->status == DASD_CQR_FAILED) {
2696                         dasd_log_sense(cqr, &cqr->irb);
2697                 }
2698
2699                 /* First of all call extended error reporting. */
2700                 if (dasd_eer_enabled(base) &&
2701                     cqr->status == DASD_CQR_FAILED) {
2702                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2703
2704                         /* restart request  */
2705                         cqr->status = DASD_CQR_FILLED;
2706                         cqr->retries = 255;
2707                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2708                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2709                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2710                                                flags);
2711                         goto restart;
2712                 }
2713
2714                 /* Process finished ERP request. */
2715                 if (cqr->refers) {
2716                         __dasd_process_erp(base, cqr);
2717                         goto restart;
2718                 }
2719
2720                 /* Rechain finished requests to final queue */
2721                 cqr->endclk = get_tod_clock();
2722                 list_move_tail(&cqr->blocklist, final_queue);
2723         }
2724 }
2725
2726 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2727 {
2728         dasd_schedule_block_bh(cqr->block);
2729 }
2730
2731 static void __dasd_block_start_head(struct dasd_block *block)
2732 {
2733         struct dasd_ccw_req *cqr;
2734
2735         if (list_empty(&block->ccw_queue))
2736                 return;
2737         /* We allways begin with the first requests on the queue, as some
2738          * of previously started requests have to be enqueued on a
2739          * dasd_device again for error recovery.
2740          */
2741         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2742                 if (cqr->status != DASD_CQR_FILLED)
2743                         continue;
2744                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2745                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2746                         cqr->status = DASD_CQR_FAILED;
2747                         cqr->intrc = -EPERM;
2748                         dasd_schedule_block_bh(block);
2749                         continue;
2750                 }
2751                 /* Non-temporary stop condition will trigger fail fast */
2752                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2753                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2754                     (!dasd_eer_enabled(block->base))) {
2755                         cqr->status = DASD_CQR_FAILED;
2756                         cqr->intrc = -ENOLINK;
2757                         dasd_schedule_block_bh(block);
2758                         continue;
2759                 }
2760                 /* Don't try to start requests if device is stopped */
2761                 if (block->base->stopped)
2762                         return;
2763
2764                 /* just a fail safe check, should not happen */
2765                 if (!cqr->startdev)
2766                         cqr->startdev = block->base;
2767
2768                 /* make sure that the requests we submit find their way back */
2769                 cqr->callback = dasd_return_cqr_cb;
2770
2771                 dasd_add_request_tail(cqr);
2772         }
2773 }
2774
2775 /*
2776  * Central dasd_block layer routine. Takes requests from the generic
2777  * block layer request queue, creates ccw requests, enqueues them on
2778  * a dasd_device and processes ccw requests that have been returned.
2779  */
2780 static void dasd_block_tasklet(struct dasd_block *block)
2781 {
2782         struct list_head final_queue;
2783         struct list_head *l, *n;
2784         struct dasd_ccw_req *cqr;
2785
2786         atomic_set(&block->tasklet_scheduled, 0);
2787         INIT_LIST_HEAD(&final_queue);
2788         spin_lock(&block->queue_lock);
2789         /* Finish off requests on ccw queue */
2790         __dasd_process_block_ccw_queue(block, &final_queue);
2791         spin_unlock(&block->queue_lock);
2792         /* Now call the callback function of requests with final status */
2793         spin_lock_irq(&block->request_queue_lock);
2794         list_for_each_safe(l, n, &final_queue) {
2795                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2796                 list_del_init(&cqr->blocklist);
2797                 __dasd_cleanup_cqr(cqr);
2798         }
2799         spin_lock(&block->queue_lock);
2800         /* Get new request from the block device request queue */
2801         __dasd_process_request_queue(block);
2802         /* Now check if the head of the ccw queue needs to be started. */
2803         __dasd_block_start_head(block);
2804         spin_unlock(&block->queue_lock);
2805         spin_unlock_irq(&block->request_queue_lock);
2806         if (waitqueue_active(&shutdown_waitq))
2807                 wake_up(&shutdown_waitq);
2808         dasd_put_device(block->base);
2809 }
2810
2811 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2812 {
2813         wake_up(&dasd_flush_wq);
2814 }
2815
2816 /*
2817  * Requeue a request back to the block request queue
2818  * only works for block requests
2819  */
2820 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2821 {
2822         struct dasd_block *block = cqr->block;
2823         struct request *req;
2824         unsigned long flags;
2825
2826         if (!block)
2827                 return -EINVAL;
2828         spin_lock_irqsave(&block->queue_lock, flags);
2829         req = (struct request *) cqr->callback_data;
2830         blk_requeue_request(block->request_queue, req);
2831         spin_unlock_irqrestore(&block->queue_lock, flags);
2832
2833         return 0;
2834 }
2835
2836 /*
2837  * Go through all request on the dasd_block request queue, cancel them
2838  * on the respective dasd_device, and return them to the generic
2839  * block layer.
2840  */
2841 static int dasd_flush_block_queue(struct dasd_block *block)
2842 {
2843         struct dasd_ccw_req *cqr, *n;
2844         int rc, i;
2845         struct list_head flush_queue;
2846
2847         INIT_LIST_HEAD(&flush_queue);
2848         spin_lock_bh(&block->queue_lock);
2849         rc = 0;
2850 restart:
2851         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2852                 /* if this request currently owned by a dasd_device cancel it */
2853                 if (cqr->status >= DASD_CQR_QUEUED)
2854                         rc = dasd_cancel_req(cqr);
2855                 if (rc < 0)
2856                         break;
2857                 /* Rechain request (including erp chain) so it won't be
2858                  * touched by the dasd_block_tasklet anymore.
2859                  * Replace the callback so we notice when the request
2860                  * is returned from the dasd_device layer.
2861                  */
2862                 cqr->callback = _dasd_wake_block_flush_cb;
2863                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2864                         list_move_tail(&cqr->blocklist, &flush_queue);
2865                 if (i > 1)
2866                         /* moved more than one request - need to restart */
2867                         goto restart;
2868         }
2869         spin_unlock_bh(&block->queue_lock);
2870         /* Now call the callback function of flushed requests */
2871 restart_cb:
2872         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2873                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2874                 /* Process finished ERP request. */
2875                 if (cqr->refers) {
2876                         spin_lock_bh(&block->queue_lock);
2877                         __dasd_process_erp(block->base, cqr);
2878                         spin_unlock_bh(&block->queue_lock);
2879                         /* restart list_for_xx loop since dasd_process_erp
2880                          * might remove multiple elements */
2881                         goto restart_cb;
2882                 }
2883                 /* call the callback function */
2884                 spin_lock_irq(&block->request_queue_lock);
2885                 cqr->endclk = get_tod_clock();
2886                 list_del_init(&cqr->blocklist);
2887                 __dasd_cleanup_cqr(cqr);
2888                 spin_unlock_irq(&block->request_queue_lock);
2889         }
2890         return rc;
2891 }
2892
2893 /*
2894  * Schedules a call to dasd_tasklet over the device tasklet.
2895  */
2896 void dasd_schedule_block_bh(struct dasd_block *block)
2897 {
2898         /* Protect against rescheduling. */
2899         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2900                 return;
2901         /* life cycle of block is bound to it's base device */
2902         dasd_get_device(block->base);
2903         tasklet_hi_schedule(&block->tasklet);
2904 }
2905 EXPORT_SYMBOL(dasd_schedule_block_bh);
2906
2907
2908 /*
2909  * SECTION: external block device operations
2910  * (request queue handling, open, release, etc.)
2911  */
2912
2913 /*
2914  * Dasd request queue function. Called from ll_rw_blk.c
2915  */
2916 static void do_dasd_request(struct request_queue *queue)
2917 {
2918         struct dasd_block *block;
2919
2920         block = queue->queuedata;
2921         spin_lock(&block->queue_lock);
2922         /* Get new request from the block device request queue */
2923         __dasd_process_request_queue(block);
2924         /* Now check if the head of the ccw queue needs to be started. */
2925         __dasd_block_start_head(block);
2926         spin_unlock(&block->queue_lock);
2927 }
2928
2929 /*
2930  * Block timeout callback, called from the block layer
2931  *
2932  * request_queue lock is held on entry.
2933  *
2934  * Return values:
2935  * BLK_EH_RESET_TIMER if the request should be left running
2936  * BLK_EH_NOT_HANDLED if the request is handled or terminated
2937  *                    by the driver.
2938  */
2939 enum blk_eh_timer_return dasd_times_out(struct request *req)
2940 {
2941         struct dasd_ccw_req *cqr = req->completion_data;
2942         struct dasd_block *block = req->q->queuedata;
2943         struct dasd_device *device;
2944         int rc = 0;
2945
2946         if (!cqr)
2947                 return BLK_EH_NOT_HANDLED;
2948
2949         device = cqr->startdev ? cqr->startdev : block->base;
2950         if (!device->blk_timeout)
2951                 return BLK_EH_RESET_TIMER;
2952         DBF_DEV_EVENT(DBF_WARNING, device,
2953                       " dasd_times_out cqr %p status %x",
2954                       cqr, cqr->status);
2955
2956         spin_lock(&block->queue_lock);
2957         spin_lock(get_ccwdev_lock(device->cdev));
2958         cqr->retries = -1;
2959         cqr->intrc = -ETIMEDOUT;
2960         if (cqr->status >= DASD_CQR_QUEUED) {
2961                 spin_unlock(get_ccwdev_lock(device->cdev));
2962                 rc = dasd_cancel_req(cqr);
2963         } else if (cqr->status == DASD_CQR_FILLED ||
2964                    cqr->status == DASD_CQR_NEED_ERP) {
2965                 cqr->status = DASD_CQR_TERMINATED;
2966                 spin_unlock(get_ccwdev_lock(device->cdev));
2967         } else if (cqr->status == DASD_CQR_IN_ERP) {
2968                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
2969
2970                 list_for_each_entry_safe(searchcqr, nextcqr,
2971                                          &block->ccw_queue, blocklist) {
2972                         tmpcqr = searchcqr;
2973                         while (tmpcqr->refers)
2974                                 tmpcqr = tmpcqr->refers;
2975                         if (tmpcqr != cqr)
2976                                 continue;
2977                         /* searchcqr is an ERP request for cqr */
2978                         searchcqr->retries = -1;
2979                         searchcqr->intrc = -ETIMEDOUT;
2980                         if (searchcqr->status >= DASD_CQR_QUEUED) {
2981                                 spin_unlock(get_ccwdev_lock(device->cdev));
2982                                 rc = dasd_cancel_req(searchcqr);
2983                                 spin_lock(get_ccwdev_lock(device->cdev));
2984                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
2985                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
2986                                 searchcqr->status = DASD_CQR_TERMINATED;
2987                                 rc = 0;
2988                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
2989                                 /*
2990                                  * Shouldn't happen; most recent ERP
2991                                  * request is at the front of queue
2992                                  */
2993                                 continue;
2994                         }
2995                         break;
2996                 }
2997                 spin_unlock(get_ccwdev_lock(device->cdev));
2998         }
2999         dasd_schedule_block_bh(block);
3000         spin_unlock(&block->queue_lock);
3001
3002         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3003 }
3004
3005 /*
3006  * Allocate and initialize request queue and default I/O scheduler.
3007  */
3008 static int dasd_alloc_queue(struct dasd_block *block)
3009 {
3010         int rc;
3011
3012         block->request_queue = blk_init_queue(do_dasd_request,
3013                                                &block->request_queue_lock);
3014         if (block->request_queue == NULL)
3015                 return -ENOMEM;
3016
3017         block->request_queue->queuedata = block;
3018
3019         elevator_exit(block->request_queue->elevator);
3020         block->request_queue->elevator = NULL;
3021         mutex_lock(&block->request_queue->sysfs_lock);
3022         rc = elevator_init(block->request_queue, "deadline");
3023         if (rc)
3024                 blk_cleanup_queue(block->request_queue);
3025         mutex_unlock(&block->request_queue->sysfs_lock);
3026         return rc;
3027 }
3028
3029 /*
3030  * Allocate and initialize request queue.
3031  */
3032 static void dasd_setup_queue(struct dasd_block *block)
3033 {
3034         int max;
3035
3036         if (block->base->features & DASD_FEATURE_USERAW) {
3037                 /*
3038                  * the max_blocks value for raw_track access is 256
3039                  * it is higher than the native ECKD value because we
3040                  * only need one ccw per track
3041                  * so the max_hw_sectors are
3042                  * 2048 x 512B = 1024kB = 16 tracks
3043                  */
3044                 max = 2048;
3045         } else {
3046                 max = block->base->discipline->max_blocks << block->s2b_shift;
3047         }
3048         blk_queue_logical_block_size(block->request_queue,
3049                                      block->bp_block);
3050         blk_queue_max_hw_sectors(block->request_queue, max);
3051         blk_queue_max_segments(block->request_queue, -1L);
3052         /* with page sized segments we can translate each segement into
3053          * one idaw/tidaw
3054          */
3055         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3056         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3057 }
3058
3059 /*
3060  * Deactivate and free request queue.
3061  */
3062 static void dasd_free_queue(struct dasd_block *block)
3063 {
3064         if (block->request_queue) {
3065                 blk_cleanup_queue(block->request_queue);
3066                 block->request_queue = NULL;
3067         }
3068 }
3069
3070 /*
3071  * Flush request on the request queue.
3072  */
3073 static void dasd_flush_request_queue(struct dasd_block *block)
3074 {
3075         struct request *req;
3076
3077         if (!block->request_queue)
3078                 return;
3079
3080         spin_lock_irq(&block->request_queue_lock);
3081         while ((req = blk_fetch_request(block->request_queue)))
3082                 __blk_end_request_all(req, -EIO);
3083         spin_unlock_irq(&block->request_queue_lock);
3084 }
3085
3086 static int dasd_open(struct block_device *bdev, fmode_t mode)
3087 {
3088         struct dasd_device *base;
3089         int rc;
3090
3091         base = dasd_device_from_gendisk(bdev->bd_disk);
3092         if (!base)
3093                 return -ENODEV;
3094
3095         atomic_inc(&base->block->open_count);
3096         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3097                 rc = -ENODEV;
3098                 goto unlock;
3099         }
3100
3101         if (!try_module_get(base->discipline->owner)) {
3102                 rc = -EINVAL;
3103                 goto unlock;
3104         }
3105
3106         if (dasd_probeonly) {
3107                 dev_info(&base->cdev->dev,
3108                          "Accessing the DASD failed because it is in "
3109                          "probeonly mode\n");
3110                 rc = -EPERM;
3111                 goto out;
3112         }
3113
3114         if (base->state <= DASD_STATE_BASIC) {
3115                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3116                               " Cannot open unrecognized device");
3117                 rc = -ENODEV;
3118                 goto out;
3119         }
3120
3121         if ((mode & FMODE_WRITE) &&
3122             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3123              (base->features & DASD_FEATURE_READONLY))) {
3124                 rc = -EROFS;
3125                 goto out;
3126         }
3127
3128         dasd_put_device(base);
3129         return 0;
3130
3131 out:
3132         module_put(base->discipline->owner);
3133 unlock:
3134         atomic_dec(&base->block->open_count);
3135         dasd_put_device(base);
3136         return rc;
3137 }
3138
3139 static void dasd_release(struct gendisk *disk, fmode_t mode)
3140 {
3141         struct dasd_device *base = dasd_device_from_gendisk(disk);
3142         if (base) {
3143                 atomic_dec(&base->block->open_count);
3144                 module_put(base->discipline->owner);
3145                 dasd_put_device(base);
3146         }
3147 }
3148
3149 /*
3150  * Return disk geometry.
3151  */
3152 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3153 {
3154         struct dasd_device *base;
3155
3156         base = dasd_device_from_gendisk(bdev->bd_disk);
3157         if (!base)
3158                 return -ENODEV;
3159
3160         if (!base->discipline ||
3161             !base->discipline->fill_geometry) {
3162                 dasd_put_device(base);
3163                 return -EINVAL;
3164         }
3165         base->discipline->fill_geometry(base->block, geo);
3166         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3167         dasd_put_device(base);
3168         return 0;
3169 }
3170
3171 const struct block_device_operations
3172 dasd_device_operations = {
3173         .owner          = THIS_MODULE,
3174         .open           = dasd_open,
3175         .release        = dasd_release,
3176         .ioctl          = dasd_ioctl,
3177         .compat_ioctl   = dasd_ioctl,
3178         .getgeo         = dasd_getgeo,
3179 };
3180
3181 /*******************************************************************************
3182  * end of block device operations
3183  */
3184
3185 static void
3186 dasd_exit(void)
3187 {
3188 #ifdef CONFIG_PROC_FS
3189         dasd_proc_exit();
3190 #endif
3191         dasd_eer_exit();
3192         if (dasd_page_cache != NULL) {
3193                 kmem_cache_destroy(dasd_page_cache);
3194                 dasd_page_cache = NULL;
3195         }
3196         dasd_gendisk_exit();
3197         dasd_devmap_exit();
3198         if (dasd_debug_area != NULL) {
3199                 debug_unregister(dasd_debug_area);
3200                 dasd_debug_area = NULL;
3201         }
3202         dasd_statistics_removeroot();
3203 }
3204
3205 /*
3206  * SECTION: common functions for ccw_driver use
3207  */
3208
3209 /*
3210  * Is the device read-only?
3211  * Note that this function does not report the setting of the
3212  * readonly device attribute, but how it is configured in z/VM.
3213  */
3214 int dasd_device_is_ro(struct dasd_device *device)
3215 {
3216         struct ccw_dev_id dev_id;
3217         struct diag210 diag_data;
3218         int rc;
3219
3220         if (!MACHINE_IS_VM)
3221                 return 0;
3222         ccw_device_get_id(device->cdev, &dev_id);
3223         memset(&diag_data, 0, sizeof(diag_data));
3224         diag_data.vrdcdvno = dev_id.devno;
3225         diag_data.vrdclen = sizeof(diag_data);
3226         rc = diag210(&diag_data);
3227         if (rc == 0 || rc == 2) {
3228                 return diag_data.vrdcvfla & 0x80;
3229         } else {
3230                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3231                           dev_id.devno, rc);
3232                 return 0;
3233         }
3234 }
3235 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3236
3237 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3238 {
3239         struct ccw_device *cdev = data;
3240         int ret;
3241
3242         ret = ccw_device_set_online(cdev);
3243         if (ret)
3244                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3245                         dev_name(&cdev->dev), ret);
3246 }
3247
3248 /*
3249  * Initial attempt at a probe function. this can be simplified once
3250  * the other detection code is gone.
3251  */
3252 int dasd_generic_probe(struct ccw_device *cdev,
3253                        struct dasd_discipline *discipline)
3254 {
3255         int ret;
3256
3257         ret = dasd_add_sysfs_files(cdev);
3258         if (ret) {
3259                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3260                                 "dasd_generic_probe: could not add "
3261                                 "sysfs entries");
3262                 return ret;
3263         }
3264         cdev->handler = &dasd_int_handler;
3265
3266         /*
3267          * Automatically online either all dasd devices (dasd_autodetect)
3268          * or all devices specified with dasd= parameters during
3269          * initial probe.
3270          */
3271         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3272             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3273                 async_schedule(dasd_generic_auto_online, cdev);
3274         return 0;
3275 }
3276 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3277
3278 /*
3279  * This will one day be called from a global not_oper handler.
3280  * It is also used by driver_unregister during module unload.
3281  */
3282 void dasd_generic_remove(struct ccw_device *cdev)
3283 {
3284         struct dasd_device *device;
3285         struct dasd_block *block;
3286
3287         cdev->handler = NULL;
3288
3289         device = dasd_device_from_cdev(cdev);
3290         if (IS_ERR(device)) {
3291                 dasd_remove_sysfs_files(cdev);
3292                 return;
3293         }
3294         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3295             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3296                 /* Already doing offline processing */
3297                 dasd_put_device(device);
3298                 dasd_remove_sysfs_files(cdev);
3299                 return;
3300         }
3301         /*
3302          * This device is removed unconditionally. Set offline
3303          * flag to prevent dasd_open from opening it while it is
3304          * no quite down yet.
3305          */
3306         dasd_set_target_state(device, DASD_STATE_NEW);
3307         /* dasd_delete_device destroys the device reference. */
3308         block = device->block;
3309         dasd_delete_device(device);
3310         /*
3311          * life cycle of block is bound to device, so delete it after
3312          * device was safely removed
3313          */
3314         if (block)
3315                 dasd_free_block(block);
3316
3317         dasd_remove_sysfs_files(cdev);
3318 }
3319 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3320
3321 /*
3322  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3323  * the device is detected for the first time and is supposed to be used
3324  * or the user has started activation through sysfs.
3325  */
3326 int dasd_generic_set_online(struct ccw_device *cdev,
3327                             struct dasd_discipline *base_discipline)
3328 {
3329         struct dasd_discipline *discipline;
3330         struct dasd_device *device;
3331         int rc;
3332
3333         /* first online clears initial online feature flag */
3334         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3335         device = dasd_create_device(cdev);
3336         if (IS_ERR(device))
3337                 return PTR_ERR(device);
3338
3339         discipline = base_discipline;
3340         if (device->features & DASD_FEATURE_USEDIAG) {
3341                 if (!dasd_diag_discipline_pointer) {
3342                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3343                                 dev_name(&cdev->dev));
3344                         dasd_delete_device(device);
3345                         return -ENODEV;
3346                 }
3347                 discipline = dasd_diag_discipline_pointer;
3348         }
3349         if (!try_module_get(base_discipline->owner)) {
3350                 dasd_delete_device(device);
3351                 return -EINVAL;
3352         }
3353         if (!try_module_get(discipline->owner)) {
3354                 module_put(base_discipline->owner);
3355                 dasd_delete_device(device);
3356                 return -EINVAL;
3357         }
3358         device->base_discipline = base_discipline;
3359         device->discipline = discipline;
3360
3361         /* check_device will allocate block device if necessary */
3362         rc = discipline->check_device(device);
3363         if (rc) {
3364                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3365                         dev_name(&cdev->dev), discipline->name, rc);
3366                 module_put(discipline->owner);
3367                 module_put(base_discipline->owner);
3368                 dasd_delete_device(device);
3369                 return rc;
3370         }
3371
3372         dasd_set_target_state(device, DASD_STATE_ONLINE);
3373         if (device->state <= DASD_STATE_KNOWN) {
3374                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3375                         dev_name(&cdev->dev));
3376                 rc = -ENODEV;
3377                 dasd_set_target_state(device, DASD_STATE_NEW);
3378                 if (device->block)
3379                         dasd_free_block(device->block);
3380                 dasd_delete_device(device);
3381         } else
3382                 pr_debug("dasd_generic device %s found\n",
3383                                 dev_name(&cdev->dev));
3384
3385         wait_event(dasd_init_waitq, _wait_for_device(device));
3386
3387         dasd_put_device(device);
3388         return rc;
3389 }
3390 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3391
3392 int dasd_generic_set_offline(struct ccw_device *cdev)
3393 {
3394         struct dasd_device *device;
3395         struct dasd_block *block;
3396         int max_count, open_count, rc;
3397
3398         rc = 0;
3399         device = dasd_device_from_cdev(cdev);
3400         if (IS_ERR(device))
3401                 return PTR_ERR(device);
3402
3403         /*
3404          * We must make sure that this device is currently not in use.
3405          * The open_count is increased for every opener, that includes
3406          * the blkdev_get in dasd_scan_partitions. We are only interested
3407          * in the other openers.
3408          */
3409         if (device->block) {
3410                 max_count = device->block->bdev ? 0 : -1;
3411                 open_count = atomic_read(&device->block->open_count);
3412                 if (open_count > max_count) {
3413                         if (open_count > 0)
3414                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3415                                         dev_name(&cdev->dev), open_count);
3416                         else
3417                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3418                                         dev_name(&cdev->dev));
3419                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3420                         dasd_put_device(device);
3421                         return -EBUSY;
3422                 }
3423         }
3424
3425         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3426                 /*
3427                  * safe offline already running
3428                  * could only be called by normal offline so safe_offline flag
3429                  * needs to be removed to run normal offline and kill all I/O
3430                  */
3431                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3432                         /* Already doing normal offline processing */
3433                         dasd_put_device(device);
3434                         return -EBUSY;
3435                 } else
3436                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3437
3438         } else
3439                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3440                         /* Already doing offline processing */
3441                         dasd_put_device(device);
3442                         return -EBUSY;
3443                 }
3444
3445         /*
3446          * if safe_offline called set safe_offline_running flag and
3447          * clear safe_offline so that a call to normal offline
3448          * can overrun safe_offline processing
3449          */
3450         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3451             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3452                 /*
3453                  * If we want to set the device safe offline all IO operations
3454                  * should be finished before continuing the offline process
3455                  * so sync bdev first and then wait for our queues to become
3456                  * empty
3457                  */
3458                 /* sync blockdev and partitions */
3459                 rc = fsync_bdev(device->block->bdev);
3460                 if (rc != 0)
3461                         goto interrupted;
3462
3463                 /* schedule device tasklet and wait for completion */
3464                 dasd_schedule_device_bh(device);
3465                 rc = wait_event_interruptible(shutdown_waitq,
3466                                               _wait_for_empty_queues(device));
3467                 if (rc != 0)
3468                         goto interrupted;
3469         }
3470
3471         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3472         dasd_set_target_state(device, DASD_STATE_NEW);
3473         /* dasd_delete_device destroys the device reference. */
3474         block = device->block;
3475         dasd_delete_device(device);
3476         /*
3477          * life cycle of block is bound to device, so delete it after
3478          * device was safely removed
3479          */
3480         if (block)
3481                 dasd_free_block(block);
3482         return 0;
3483
3484 interrupted:
3485         /* interrupted by signal */
3486         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3487         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3488         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3489         dasd_put_device(device);
3490         return rc;
3491 }
3492 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3493
3494 int dasd_generic_last_path_gone(struct dasd_device *device)
3495 {
3496         struct dasd_ccw_req *cqr;
3497
3498         dev_warn(&device->cdev->dev, "No operational channel path is left "
3499                  "for the device\n");
3500         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3501         /* First of all call extended error reporting. */
3502         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3503
3504         if (device->state < DASD_STATE_BASIC)
3505                 return 0;
3506         /* Device is active. We want to keep it. */
3507         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3508                 if ((cqr->status == DASD_CQR_IN_IO) ||
3509                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3510                         cqr->status = DASD_CQR_QUEUED;
3511                         cqr->retries++;
3512                 }
3513         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3514         dasd_device_clear_timer(device);
3515         dasd_schedule_device_bh(device);
3516         return 1;
3517 }
3518 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3519
3520 int dasd_generic_path_operational(struct dasd_device *device)
3521 {
3522         dev_info(&device->cdev->dev, "A channel path to the device has become "
3523                  "operational\n");
3524         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3525         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3526         if (device->stopped & DASD_UNRESUMED_PM) {
3527                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3528                 dasd_restore_device(device);
3529                 return 1;
3530         }
3531         dasd_schedule_device_bh(device);
3532         if (device->block)
3533                 dasd_schedule_block_bh(device->block);
3534
3535         if (!device->stopped)
3536                 wake_up(&generic_waitq);
3537
3538         return 1;
3539 }
3540 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3541
3542 int dasd_generic_notify(struct ccw_device *cdev, int event)
3543 {
3544         struct dasd_device *device;
3545         int ret;
3546
3547         device = dasd_device_from_cdev_locked(cdev);
3548         if (IS_ERR(device))
3549                 return 0;
3550         ret = 0;
3551         switch (event) {
3552         case CIO_GONE:
3553         case CIO_BOXED:
3554         case CIO_NO_PATH:
3555                 device->path_data.opm = 0;
3556                 device->path_data.ppm = 0;
3557                 device->path_data.npm = 0;
3558                 ret = dasd_generic_last_path_gone(device);
3559                 break;
3560         case CIO_OPER:
3561                 ret = 1;
3562                 if (device->path_data.opm)
3563                         ret = dasd_generic_path_operational(device);
3564                 break;
3565         }
3566         dasd_put_device(device);
3567         return ret;
3568 }
3569 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3570
3571 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3572 {
3573         int chp;
3574         __u8 oldopm, eventlpm;
3575         struct dasd_device *device;
3576
3577         device = dasd_device_from_cdev_locked(cdev);
3578         if (IS_ERR(device))
3579                 return;
3580         for (chp = 0; chp < 8; chp++) {
3581                 eventlpm = 0x80 >> chp;
3582                 if (path_event[chp] & PE_PATH_GONE) {
3583                         oldopm = device->path_data.opm;
3584                         device->path_data.opm &= ~eventlpm;
3585                         device->path_data.ppm &= ~eventlpm;
3586                         device->path_data.npm &= ~eventlpm;
3587                         if (oldopm && !device->path_data.opm) {
3588                                 dev_warn(&device->cdev->dev,
3589                                          "No verified channel paths remain "
3590                                          "for the device\n");
3591                                 DBF_DEV_EVENT(DBF_WARNING, device,
3592                                               "%s", "last verified path gone");
3593                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3594                                 dasd_device_set_stop_bits(device,
3595                                                           DASD_STOPPED_DC_WAIT);
3596                         }
3597                 }
3598                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3599                         device->path_data.opm &= ~eventlpm;
3600                         device->path_data.ppm &= ~eventlpm;
3601                         device->path_data.npm &= ~eventlpm;
3602                         device->path_data.tbvpm |= eventlpm;
3603                         dasd_schedule_device_bh(device);
3604                 }
3605                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3606                         if (!(device->path_data.opm & eventlpm) &&
3607                             !(device->path_data.tbvpm & eventlpm)) {
3608                                 /*
3609                                  * we can not establish a pathgroup on an
3610                                  * unavailable path, so trigger a path
3611                                  * verification first
3612                                  */
3613                                 device->path_data.tbvpm |= eventlpm;
3614                                 dasd_schedule_device_bh(device);
3615                         }
3616                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3617                                       "Pathgroup re-established\n");
3618                         if (device->discipline->kick_validate)
3619                                 device->discipline->kick_validate(device);
3620                 }
3621         }
3622         dasd_put_device(device);
3623 }
3624 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3625
3626 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3627 {
3628         if (!device->path_data.opm && lpm) {
3629                 device->path_data.opm = lpm;
3630                 dasd_generic_path_operational(device);
3631         } else
3632                 device->path_data.opm |= lpm;
3633         return 0;
3634 }
3635 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3636
3637
3638 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3639 {
3640         struct dasd_device *device = dasd_device_from_cdev(cdev);
3641         struct list_head freeze_queue;
3642         struct dasd_ccw_req *cqr, *n;
3643         struct dasd_ccw_req *refers;
3644         int rc;
3645
3646         if (IS_ERR(device))
3647                 return PTR_ERR(device);
3648
3649         /* mark device as suspended */
3650         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3651
3652         if (device->discipline->freeze)
3653                 rc = device->discipline->freeze(device);
3654
3655         /* disallow new I/O  */
3656         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3657
3658         /* clear active requests and requeue them to block layer if possible */
3659         INIT_LIST_HEAD(&freeze_queue);
3660         spin_lock_irq(get_ccwdev_lock(cdev));
3661         rc = 0;
3662         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3663                 /* Check status and move request to flush_queue */
3664                 if (cqr->status == DASD_CQR_IN_IO) {
3665                         rc = device->discipline->term_IO(cqr);
3666                         if (rc) {
3667                                 /* unable to terminate requeust */
3668                                 dev_err(&device->cdev->dev,
3669                                         "Unable to terminate request %p "
3670                                         "on suspend\n", cqr);
3671                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3672                                 dasd_put_device(device);
3673                                 return rc;
3674                         }
3675                 }
3676                 list_move_tail(&cqr->devlist, &freeze_queue);
3677         }
3678         spin_unlock_irq(get_ccwdev_lock(cdev));
3679
3680         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3681                 wait_event(dasd_flush_wq,
3682                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3683                 if (cqr->status == DASD_CQR_CLEARED)
3684                         cqr->status = DASD_CQR_QUEUED;
3685
3686                 /* requeue requests to blocklayer will only work for
3687                    block device requests */
3688                 if (_dasd_requeue_request(cqr))
3689                         continue;
3690
3691                 /* remove requests from device and block queue */
3692                 list_del_init(&cqr->devlist);
3693                 while (cqr->refers != NULL) {
3694                         refers = cqr->refers;
3695                         /* remove the request from the block queue */
3696                         list_del(&cqr->blocklist);
3697                         /* free the finished erp request */
3698                         dasd_free_erp_request(cqr, cqr->memdev);
3699                         cqr = refers;
3700                 }
3701                 if (cqr->block)
3702                         list_del_init(&cqr->blocklist);
3703                 cqr->block->base->discipline->free_cp(
3704                         cqr, (struct request *) cqr->callback_data);
3705         }
3706
3707         /*
3708          * if requests remain then they are internal request
3709          * and go back to the device queue
3710          */
3711         if (!list_empty(&freeze_queue)) {
3712                 /* move freeze_queue to start of the ccw_queue */
3713                 spin_lock_irq(get_ccwdev_lock(cdev));
3714                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3715                 spin_unlock_irq(get_ccwdev_lock(cdev));
3716         }
3717         dasd_put_device(device);
3718         return rc;
3719 }
3720 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3721
3722 int dasd_generic_restore_device(struct ccw_device *cdev)
3723 {
3724         struct dasd_device *device = dasd_device_from_cdev(cdev);
3725         int rc = 0;
3726
3727         if (IS_ERR(device))
3728                 return PTR_ERR(device);
3729
3730         /* allow new IO again */
3731         dasd_device_remove_stop_bits(device,
3732                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3733
3734         dasd_schedule_device_bh(device);
3735
3736         /*
3737          * call discipline restore function
3738          * if device is stopped do nothing e.g. for disconnected devices
3739          */
3740         if (device->discipline->restore && !(device->stopped))
3741                 rc = device->discipline->restore(device);
3742         if (rc || device->stopped)
3743                 /*
3744                  * if the resume failed for the DASD we put it in
3745                  * an UNRESUMED stop state
3746                  */
3747                 device->stopped |= DASD_UNRESUMED_PM;
3748
3749         if (device->block)
3750                 dasd_schedule_block_bh(device->block);
3751
3752         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3753         dasd_put_device(device);
3754         return 0;
3755 }
3756 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3757
3758 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3759                                                    void *rdc_buffer,
3760                                                    int rdc_buffer_size,
3761                                                    int magic)
3762 {
3763         struct dasd_ccw_req *cqr;
3764         struct ccw1 *ccw;
3765         unsigned long *idaw;
3766
3767         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3768
3769         if (IS_ERR(cqr)) {
3770                 /* internal error 13 - Allocating the RDC request failed*/
3771                 dev_err(&device->cdev->dev,
3772                          "An error occurred in the DASD device driver, "
3773                          "reason=%s\n", "13");
3774                 return cqr;
3775         }
3776
3777         ccw = cqr->cpaddr;
3778         ccw->cmd_code = CCW_CMD_RDC;
3779         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3780                 idaw = (unsigned long *) (cqr->data);
3781                 ccw->cda = (__u32)(addr_t) idaw;
3782                 ccw->flags = CCW_FLAG_IDA;
3783                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3784         } else {
3785                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3786                 ccw->flags = 0;
3787         }
3788
3789         ccw->count = rdc_buffer_size;
3790         cqr->startdev = device;
3791         cqr->memdev = device;
3792         cqr->expires = 10*HZ;
3793         cqr->retries = 256;
3794         cqr->buildclk = get_tod_clock();
3795         cqr->status = DASD_CQR_FILLED;
3796         return cqr;
3797 }
3798
3799
3800 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3801                                 void *rdc_buffer, int rdc_buffer_size)
3802 {
3803         int ret;
3804         struct dasd_ccw_req *cqr;
3805
3806         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3807                                      magic);
3808         if (IS_ERR(cqr))
3809                 return PTR_ERR(cqr);
3810
3811         ret = dasd_sleep_on(cqr);
3812         dasd_sfree_request(cqr, cqr->memdev);
3813         return ret;
3814 }
3815 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3816
3817 /*
3818  *   In command mode and transport mode we need to look for sense
3819  *   data in different places. The sense data itself is allways
3820  *   an array of 32 bytes, so we can unify the sense data access
3821  *   for both modes.
3822  */
3823 char *dasd_get_sense(struct irb *irb)
3824 {
3825         struct tsb *tsb = NULL;
3826         char *sense = NULL;
3827
3828         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3829                 if (irb->scsw.tm.tcw)
3830                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3831                                           irb->scsw.tm.tcw);
3832                 if (tsb && tsb->length == 64 && tsb->flags)
3833                         switch (tsb->flags & 0x07) {
3834                         case 1: /* tsa_iostat */
3835                                 sense = tsb->tsa.iostat.sense;
3836                                 break;
3837                         case 2: /* tsa_ddpc */
3838                                 sense = tsb->tsa.ddpc.sense;
3839                                 break;
3840                         default:
3841                                 /* currently we don't use interrogate data */
3842                                 break;
3843                         }
3844         } else if (irb->esw.esw0.erw.cons) {
3845                 sense = irb->ecw;
3846         }
3847         return sense;
3848 }
3849 EXPORT_SYMBOL_GPL(dasd_get_sense);
3850
3851 void dasd_generic_shutdown(struct ccw_device *cdev)
3852 {
3853         struct dasd_device *device;
3854
3855         device = dasd_device_from_cdev(cdev);
3856         if (IS_ERR(device))
3857                 return;
3858
3859         if (device->block)
3860                 dasd_schedule_block_bh(device->block);
3861
3862         dasd_schedule_device_bh(device);
3863
3864         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3865 }
3866 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3867
3868 static int __init dasd_init(void)
3869 {
3870         int rc;
3871
3872         init_waitqueue_head(&dasd_init_waitq);
3873         init_waitqueue_head(&dasd_flush_wq);
3874         init_waitqueue_head(&generic_waitq);
3875         init_waitqueue_head(&shutdown_waitq);
3876
3877         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3878         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3879         if (dasd_debug_area == NULL) {
3880                 rc = -ENOMEM;
3881                 goto failed;
3882         }
3883         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3884         debug_set_level(dasd_debug_area, DBF_WARNING);
3885
3886         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3887
3888         dasd_diag_discipline_pointer = NULL;
3889
3890         dasd_statistics_createroot();
3891
3892         rc = dasd_devmap_init();
3893         if (rc)
3894                 goto failed;
3895         rc = dasd_gendisk_init();
3896         if (rc)
3897                 goto failed;
3898         rc = dasd_parse();
3899         if (rc)
3900                 goto failed;
3901         rc = dasd_eer_init();
3902         if (rc)
3903                 goto failed;
3904 #ifdef CONFIG_PROC_FS
3905         rc = dasd_proc_init();
3906         if (rc)
3907                 goto failed;
3908 #endif
3909
3910         return 0;
3911 failed:
3912         pr_info("The DASD device driver could not be initialized\n");
3913         dasd_exit();
3914         return rc;
3915 }
3916
3917 module_init(dasd_init);
3918 module_exit(dasd_exit);