drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 #define DASD_DIAG_MOD           "dasd_diag_mod"
  42
  43 /*
  44  * SECTION: exported variables of dasd.c
  45  */
  46 debug_info_t *dasd_debug_area;
  47 EXPORT_SYMBOL(dasd_debug_area);
  48 static struct dentry *dasd_debugfs_root_entry;
  49 struct dasd_discipline *dasd_diag_discipline_pointer;
  50 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  52
  53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  55                    " Copyright IBM Corp. 2000");
  56 MODULE_SUPPORTED_DEVICE("dasd");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int  dasd_alloc_queue(struct dasd_block *);
  63 static void dasd_setup_queue(struct dasd_block *);
  64 static void dasd_free_queue(struct dasd_block *);
  65 static void dasd_flush_request_queue(struct dasd_block *);
  66 static int dasd_flush_block_queue(struct dasd_block *);
  67 static void dasd_device_tasklet(struct dasd_device *);
  68 static void dasd_block_tasklet(struct dasd_block *);
  69 static void do_kick_device(struct work_struct *);
  70 static void do_restore_device(struct work_struct *);
  71 static void do_reload_device(struct work_struct *);
  72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  73 static void dasd_device_timeout(unsigned long);
  74 static void dasd_block_timeout(unsigned long);
  75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  77 static void dasd_profile_exit(struct dasd_profile *);
  78 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  79 static void dasd_hosts_exit(struct dasd_device *);
  80
  81 /*
  82  * SECTION: Operations on the device structure.
  83  */
  84 static wait_queue_head_t dasd_init_waitq;
  85 static wait_queue_head_t dasd_flush_wq;
  86 static wait_queue_head_t generic_waitq;
  87 static wait_queue_head_t shutdown_waitq;
  88
  89 /*
  90  * Allocate memory for a new device structure.
  91  */
  92 struct dasd_device *dasd_alloc_device(void)
  93 {
  94         struct dasd_device *device;
  95
  96         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  97         if (!device)
  98                 return ERR_PTR(-ENOMEM);
  99
 100         /* Get two pages for normal block device operations. */
 101         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 102         if (!device->ccw_mem) {
 103                 kfree(device);
 104                 return ERR_PTR(-ENOMEM);
 105         }
 106         /* Get one page for error recovery. */
 107         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 108         if (!device->erp_mem) {
 109                 free_pages((unsigned long) device->ccw_mem, 1);
 110                 kfree(device);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 115         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 116         spin_lock_init(&device->mem_lock);
 117         atomic_set(&device->tasklet_scheduled, 0);
 118         tasklet_init(&device->tasklet,
 119                      (void (*)(unsigned long)) dasd_device_tasklet,
 120                      (unsigned long) device);
 121         INIT_LIST_HEAD(&device->ccw_queue);
 122         init_timer(&device->timer);
 123         device->timer.function = dasd_device_timeout;
 124         device->timer.data = (unsigned long) device;
 125         INIT_WORK(&device->kick_work, do_kick_device);
 126         INIT_WORK(&device->restore_device, do_restore_device);
 127         INIT_WORK(&device->reload_device, do_reload_device);
 128         device->state = DASD_STATE_NEW;
 129         device->target = DASD_STATE_NEW;
 130         mutex_init(&device->state_mutex);
 131         spin_lock_init(&device->profile.lock);
 132         return device;
 133 }
 134
 135 /*
 136  * Free memory of a device structure.
 137  */
 138 void dasd_free_device(struct dasd_device *device)
 139 {
 140         kfree(device->private);
 141         free_page((unsigned long) device->erp_mem);
 142         free_pages((unsigned long) device->ccw_mem, 1);
 143         kfree(device);
 144 }
 145
 146 /*
 147  * Allocate memory for a new device structure.
 148  */
 149 struct dasd_block *dasd_alloc_block(void)
 150 {
 151         struct dasd_block *block;
 152
 153         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 154         if (!block)
 155                 return ERR_PTR(-ENOMEM);
 156         /* open_count = 0 means device online but not in use */
 157         atomic_set(&block->open_count, -1);
 158
 159         spin_lock_init(&block->request_queue_lock);
 160         atomic_set(&block->tasklet_scheduled, 0);
 161         tasklet_init(&block->tasklet,
 162                      (void (*)(unsigned long)) dasd_block_tasklet,
 163                      (unsigned long) block);
 164         INIT_LIST_HEAD(&block->ccw_queue);
 165         spin_lock_init(&block->queue_lock);
 166         init_timer(&block->timer);
 167         block->timer.function = dasd_block_timeout;
 168         block->timer.data = (unsigned long) block;
 169         spin_lock_init(&block->profile.lock);
 170
 171         return block;
 172 }
 173 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 174
 175 /*
 176  * Free memory of a device structure.
 177  */
 178 void dasd_free_block(struct dasd_block *block)
 179 {
 180         kfree(block);
 181 }
 182 EXPORT_SYMBOL_GPL(dasd_free_block);
 183
 184 /*
 185  * Make a new device known to the system.
 186  */
 187 static int dasd_state_new_to_known(struct dasd_device *device)
 188 {
 189         int rc;
 190
 191         /*
 192          * As long as the device is not in state DASD_STATE_NEW we want to
 193          * keep the reference count > 0.
 194          */
 195         dasd_get_device(device);
 196
 197         if (device->block) {
 198                 rc = dasd_alloc_queue(device->block);
 199                 if (rc) {
 200                         dasd_put_device(device);
 201                         return rc;
 202                 }
 203         }
 204         device->state = DASD_STATE_KNOWN;
 205         return 0;
 206 }
 207
 208 /*
 209  * Let the system forget about a device.
 210  */
 211 static int dasd_state_known_to_new(struct dasd_device *device)
 212 {
 213         /* Disable extended error reporting for this device. */
 214         dasd_eer_disable(device);
 215         /* Forget the discipline information. */
 216         if (device->discipline) {
 217                 if (device->discipline->uncheck_device)
 218                         device->discipline->uncheck_device(device);
 219                 module_put(device->discipline->owner);
 220         }
 221         device->discipline = NULL;
 222         if (device->base_discipline)
 223                 module_put(device->base_discipline->owner);
 224         device->base_discipline = NULL;
 225         device->state = DASD_STATE_NEW;
 226
 227         if (device->block)
 228                 dasd_free_queue(device->block);
 229
 230         /* Give up reference we took in dasd_state_new_to_known. */
 231         dasd_put_device(device);
 232         return 0;
 233 }
 234
 235 static struct dentry *dasd_debugfs_setup(const char *name,
 236                                          struct dentry *base_dentry)
 237 {
 238         struct dentry *pde;
 239
 240         if (!base_dentry)
 241                 return NULL;
 242         pde = debugfs_create_dir(name, base_dentry);
 243         if (!pde || IS_ERR(pde))
 244                 return NULL;
 245         return pde;
 246 }
 247
 248 /*
 249  * Request the irq line for the device.
 250  */
 251 static int dasd_state_known_to_basic(struct dasd_device *device)
 252 {
 253         struct dasd_block *block = device->block;
 254         int rc = 0;
 255
 256         /* Allocate and register gendisk structure. */
 257         if (block) {
 258                 rc = dasd_gendisk_alloc(block);
 259                 if (rc)
 260                         return rc;
 261                 block->debugfs_dentry =
 262                         dasd_debugfs_setup(block->gdp->disk_name,
 263                                            dasd_debugfs_root_entry);
 264                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 265                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 266                         dasd_profile_on(&device->block->profile);
 267         }
 268         device->debugfs_dentry =
 269                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 270                                    dasd_debugfs_root_entry);
 271         dasd_profile_init(&device->profile, device->debugfs_dentry);
 272         dasd_hosts_init(device->debugfs_dentry, device);
 273
 274         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 275         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 276                                             8 * sizeof(long));
 277         debug_register_view(device->debug_area, &debug_sprintf_view);
 278         debug_set_level(device->debug_area, DBF_WARNING);
 279         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 280
 281         device->state = DASD_STATE_BASIC;
 282
 283         return rc;
 284 }
 285
 286 /*
 287  * Release the irq line for the device. Terminate any running i/o.
 288  */
 289 static int dasd_state_basic_to_known(struct dasd_device *device)
 290 {
 291         int rc;
 292
 293         if (device->discipline->basic_to_known) {
 294                 rc = device->discipline->basic_to_known(device);
 295                 if (rc)
 296                         return rc;
 297         }
 298
 299         if (device->block) {
 300                 dasd_profile_exit(&device->block->profile);
 301                 debugfs_remove(device->block->debugfs_dentry);
 302                 dasd_gendisk_free(device->block);
 303                 dasd_block_clear_timer(device->block);
 304         }
 305         rc = dasd_flush_device_queue(device);
 306         if (rc)
 307                 return rc;
 308         dasd_device_clear_timer(device);
 309         dasd_profile_exit(&device->profile);
 310         dasd_hosts_exit(device);
 311         debugfs_remove(device->debugfs_dentry);
 312         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 313         if (device->debug_area != NULL) {
 314                 debug_unregister(device->debug_area);
 315                 device->debug_area = NULL;
 316         }
 317         device->state = DASD_STATE_KNOWN;
 318         return 0;
 319 }
 320
 321 /*
 322  * Do the initial analysis. The do_analysis function may return
 323  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 324  * until the discipline decides to continue the startup sequence
 325  * by calling the function dasd_change_state. The eckd disciplines
 326  * uses this to start a ccw that detects the format. The completion
 327  * interrupt for this detection ccw uses the kernel event daemon to
 328  * trigger the call to dasd_change_state. All this is done in the
 329  * discipline code, see dasd_eckd.c.
 330  * After the analysis ccw is done (do_analysis returned 0) the block
 331  * device is setup.
 332  * In case the analysis returns an error, the device setup is stopped
 333  * (a fake disk was already added to allow formatting).
 334  */
 335 static int dasd_state_basic_to_ready(struct dasd_device *device)
 336 {
 337         int rc;
 338         struct dasd_block *block;
 339
 340         rc = 0;
 341         block = device->block;
 342         /* make disk known with correct capacity */
 343         if (block) {
 344                 if (block->base->discipline->do_analysis != NULL)
 345                         rc = block->base->discipline->do_analysis(block);
 346                 if (rc) {
 347                         if (rc != -EAGAIN) {
 348                                 device->state = DASD_STATE_UNFMT;
 349                                 goto out;
 350                         }
 351                         return rc;
 352                 }
 353                 dasd_setup_queue(block);
 354                 set_capacity(block->gdp,
 355                              block->blocks << block->s2b_shift);
 356                 device->state = DASD_STATE_READY;
 357                 rc = dasd_scan_partitions(block);
 358                 if (rc) {
 359                         device->state = DASD_STATE_BASIC;
 360                         return rc;
 361                 }
 362         } else {
 363                 device->state = DASD_STATE_READY;
 364         }
 365 out:
 366         if (device->discipline->basic_to_ready)
 367                 rc = device->discipline->basic_to_ready(device);
 368         return rc;
 369 }
 370
 371 static inline
 372 int _wait_for_empty_queues(struct dasd_device *device)
 373 {
 374         if (device->block)
 375                 return list_empty(&device->ccw_queue) &&
 376                         list_empty(&device->block->ccw_queue);
 377         else
 378                 return list_empty(&device->ccw_queue);
 379 }
 380
 381 /*
 382  * Remove device from block device layer. Destroy dirty buffers.
 383  * Forget format information. Check if the target level is basic
 384  * and if it is create fake disk for formatting.
 385  */
 386 static int dasd_state_ready_to_basic(struct dasd_device *device)
 387 {
 388         int rc;
 389
 390         device->state = DASD_STATE_BASIC;
 391         if (device->block) {
 392                 struct dasd_block *block = device->block;
 393                 rc = dasd_flush_block_queue(block);
 394                 if (rc) {
 395                         device->state = DASD_STATE_READY;
 396                         return rc;
 397                 }
 398                 dasd_flush_request_queue(block);
 399                 dasd_destroy_partitions(block);
 400                 block->blocks = 0;
 401                 block->bp_block = 0;
 402                 block->s2b_shift = 0;
 403         }
 404         return 0;
 405 }
 406
 407 /*
 408  * Back to basic.
 409  */
 410 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 411 {
 412         device->state = DASD_STATE_BASIC;
 413         return 0;
 414 }
 415
 416 /*
 417  * Make the device online and schedule the bottom half to start
 418  * the requeueing of requests from the linux request queue to the
 419  * ccw queue.
 420  */
 421 static int
 422 dasd_state_ready_to_online(struct dasd_device * device)
 423 {
 424         struct gendisk *disk;
 425         struct disk_part_iter piter;
 426         struct hd_struct *part;
 427
 428         device->state = DASD_STATE_ONLINE;
 429         if (device->block) {
 430                 dasd_schedule_block_bh(device->block);
 431                 if ((device->features & DASD_FEATURE_USERAW)) {
 432                         disk = device->block->gdp;
 433                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 434                         return 0;
 435                 }
 436                 disk = device->block->bdev->bd_disk;
 437                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 438                 while ((part = disk_part_iter_next(&piter)))
 439                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 440                 disk_part_iter_exit(&piter);
 441         }
 442         return 0;
 443 }
 444
 445 /*
 446  * Stop the requeueing of requests again.
 447  */
 448 static int dasd_state_online_to_ready(struct dasd_device *device)
 449 {
 450         int rc;
 451         struct gendisk *disk;
 452         struct disk_part_iter piter;
 453         struct hd_struct *part;
 454
 455         if (device->discipline->online_to_ready) {
 456                 rc = device->discipline->online_to_ready(device);
 457                 if (rc)
 458                         return rc;
 459         }
 460
 461         device->state = DASD_STATE_READY;
 462         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 463                 disk = device->block->bdev->bd_disk;
 464                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 465                 while ((part = disk_part_iter_next(&piter)))
 466                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 467                 disk_part_iter_exit(&piter);
 468         }
 469         return 0;
 470 }
 471
 472 /*
 473  * Device startup state changes.
 474  */
 475 static int dasd_increase_state(struct dasd_device *device)
 476 {
 477         int rc;
 478
 479         rc = 0;
 480         if (device->state == DASD_STATE_NEW &&
 481             device->target >= DASD_STATE_KNOWN)
 482                 rc = dasd_state_new_to_known(device);
 483
 484         if (!rc &&
 485             device->state == DASD_STATE_KNOWN &&
 486             device->target >= DASD_STATE_BASIC)
 487                 rc = dasd_state_known_to_basic(device);
 488
 489         if (!rc &&
 490             device->state == DASD_STATE_BASIC &&
 491             device->target >= DASD_STATE_READY)
 492                 rc = dasd_state_basic_to_ready(device);
 493
 494         if (!rc &&
 495             device->state == DASD_STATE_UNFMT &&
 496             device->target > DASD_STATE_UNFMT)
 497                 rc = -EPERM;
 498
 499         if (!rc &&
 500             device->state == DASD_STATE_READY &&
 501             device->target >= DASD_STATE_ONLINE)
 502                 rc = dasd_state_ready_to_online(device);
 503
 504         return rc;
 505 }
 506
 507 /*
 508  * Device shutdown state changes.
 509  */
 510 static int dasd_decrease_state(struct dasd_device *device)
 511 {
 512         int rc;
 513
 514         rc = 0;
 515         if (device->state == DASD_STATE_ONLINE &&
 516             device->target <= DASD_STATE_READY)
 517                 rc = dasd_state_online_to_ready(device);
 518
 519         if (!rc &&
 520             device->state == DASD_STATE_READY &&
 521             device->target <= DASD_STATE_BASIC)
 522                 rc = dasd_state_ready_to_basic(device);
 523
 524         if (!rc &&
 525             device->state == DASD_STATE_UNFMT &&
 526             device->target <= DASD_STATE_BASIC)
 527                 rc = dasd_state_unfmt_to_basic(device);
 528
 529         if (!rc &&
 530             device->state == DASD_STATE_BASIC &&
 531             device->target <= DASD_STATE_KNOWN)
 532                 rc = dasd_state_basic_to_known(device);
 533
 534         if (!rc &&
 535             device->state == DASD_STATE_KNOWN &&
 536             device->target <= DASD_STATE_NEW)
 537                 rc = dasd_state_known_to_new(device);
 538
 539         return rc;
 540 }
 541
 542 /*
 543  * This is the main startup/shutdown routine.
 544  */
 545 static void dasd_change_state(struct dasd_device *device)
 546 {
 547         int rc;
 548
 549         if (device->state == device->target)
 550                 /* Already where we want to go today... */
 551                 return;
 552         if (device->state < device->target)
 553                 rc = dasd_increase_state(device);
 554         else
 555                 rc = dasd_decrease_state(device);
 556         if (rc == -EAGAIN)
 557                 return;
 558         if (rc)
 559                 device->target = device->state;
 560
 561         /* let user-space know that the device status changed */
 562         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 563
 564         if (device->state == device->target)
 565                 wake_up(&dasd_init_waitq);
 566 }
 567
 568 /*
 569  * Kick starter for devices that did not complete the startup/shutdown
 570  * procedure or were sleeping because of a pending state.
 571  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 572  * event daemon.
 573  */
 574 static void do_kick_device(struct work_struct *work)
 575 {
 576         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 577         mutex_lock(&device->state_mutex);
 578         dasd_change_state(device);
 579         mutex_unlock(&device->state_mutex);
 580         dasd_schedule_device_bh(device);
 581         dasd_put_device(device);
 582 }
 583
 584 void dasd_kick_device(struct dasd_device *device)
 585 {
 586         dasd_get_device(device);
 587         /* queue call to dasd_kick_device to the kernel event daemon. */
 588         if (!schedule_work(&device->kick_work))
 589                 dasd_put_device(device);
 590 }
 591 EXPORT_SYMBOL(dasd_kick_device);
 592
 593 /*
 594  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 595  * event daemon.
 596  */
 597 static void do_reload_device(struct work_struct *work)
 598 {
 599         struct dasd_device *device = container_of(work, struct dasd_device,
 600                                                   reload_device);
 601         device->discipline->reload(device);
 602         dasd_put_device(device);
 603 }
 604
 605 void dasd_reload_device(struct dasd_device *device)
 606 {
 607         dasd_get_device(device);
 608         /* queue call to dasd_reload_device to the kernel event daemon. */
 609         if (!schedule_work(&device->reload_device))
 610                 dasd_put_device(device);
 611 }
 612 EXPORT_SYMBOL(dasd_reload_device);
 613
 614 /*
 615  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 616  * event daemon.
 617  */
 618 static void do_restore_device(struct work_struct *work)
 619 {
 620         struct dasd_device *device = container_of(work, struct dasd_device,
 621                                                   restore_device);
 622         device->cdev->drv->restore(device->cdev);
 623         dasd_put_device(device);
 624 }
 625
 626 void dasd_restore_device(struct dasd_device *device)
 627 {
 628         dasd_get_device(device);
 629         /* queue call to dasd_restore_device to the kernel event daemon. */
 630         if (!schedule_work(&device->restore_device))
 631                 dasd_put_device(device);
 632 }
 633
 634 /*
 635  * Set the target state for a device and starts the state change.
 636  */
 637 void dasd_set_target_state(struct dasd_device *device, int target)
 638 {
 639         dasd_get_device(device);
 640         mutex_lock(&device->state_mutex);
 641         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 642         if (dasd_probeonly && target > DASD_STATE_READY)
 643                 target = DASD_STATE_READY;
 644         if (device->target != target) {
 645                 if (device->state == target)
 646                         wake_up(&dasd_init_waitq);
 647                 device->target = target;
 648         }
 649         if (device->state != device->target)
 650                 dasd_change_state(device);
 651         mutex_unlock(&device->state_mutex);
 652         dasd_put_device(device);
 653 }
 654 EXPORT_SYMBOL(dasd_set_target_state);
 655
 656 /*
 657  * Enable devices with device numbers in [from..to].
 658  */
 659 static inline int _wait_for_device(struct dasd_device *device)
 660 {
 661         return (device->state == device->target);
 662 }
 663
 664 void dasd_enable_device(struct dasd_device *device)
 665 {
 666         dasd_set_target_state(device, DASD_STATE_ONLINE);
 667         if (device->state <= DASD_STATE_KNOWN)
 668                 /* No discipline for device found. */
 669                 dasd_set_target_state(device, DASD_STATE_NEW);
 670         /* Now wait for the devices to come up. */
 671         wait_event(dasd_init_waitq, _wait_for_device(device));
 672
 673         dasd_reload_device(device);
 674         if (device->discipline->kick_validate)
 675                 device->discipline->kick_validate(device);
 676 }
 677 EXPORT_SYMBOL(dasd_enable_device);
 678
 679 /*
 680  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 681  */
 682
 683 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 684
 685 #ifdef CONFIG_DASD_PROFILE
 686 struct dasd_profile dasd_global_profile = {
 687         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 688 };
 689 static struct dentry *dasd_debugfs_global_entry;
 690
 691 /*
 692  * Add profiling information for cqr before execution.
 693  */
 694 static void dasd_profile_start(struct dasd_block *block,
 695                                struct dasd_ccw_req *cqr,
 696                                struct request *req)
 697 {
 698         struct list_head *l;
 699         unsigned int counter;
 700         struct dasd_device *device;
 701
 702         /* count the length of the chanq for statistics */
 703         counter = 0;
 704         if (dasd_global_profile_level || block->profile.data)
 705                 list_for_each(l, &block->ccw_queue)
 706                         if (++counter >= 31)
 707                                 break;
 708
 709         spin_lock(&dasd_global_profile.lock);
 710         if (dasd_global_profile.data) {
 711                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 712                 if (rq_data_dir(req) == READ)
 713                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 714         }
 715         spin_unlock(&dasd_global_profile.lock);
 716
 717         spin_lock(&block->profile.lock);
 718         if (block->profile.data) {
 719                 block->profile.data->dasd_io_nr_req[counter]++;
 720                 if (rq_data_dir(req) == READ)
 721                         block->profile.data->dasd_read_nr_req[counter]++;
 722         }
 723         spin_unlock(&block->profile.lock);
 724
 725         /*
 726          * We count the request for the start device, even though it may run on
 727          * some other device due to error recovery. This way we make sure that
 728          * we count each request only once.
 729          */
 730         device = cqr->startdev;
 731         if (device->profile.data) {
 732                 counter = 1; /* request is not yet queued on the start device */
 733                 list_for_each(l, &device->ccw_queue)
 734                         if (++counter >= 31)
 735                                 break;
 736         }
 737         spin_lock(&device->profile.lock);
 738         if (device->profile.data) {
 739                 device->profile.data->dasd_io_nr_req[counter]++;
 740                 if (rq_data_dir(req) == READ)
 741                         device->profile.data->dasd_read_nr_req[counter]++;
 742         }
 743         spin_unlock(&device->profile.lock);
 744 }
 745
 746 /*
 747  * Add profiling information for cqr after execution.
 748  */
 749
 750 #define dasd_profile_counter(value, index)                         \
 751 {                                                                  \
 752         for (index = 0; index < 31 && value >> (2+index); index++) \
 753                 ;                                                  \
 754 }
 755
 756 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 757                                       int is_alias,
 758                                       int is_tpm,
 759                                       int is_read,
 760                                       long sectors,
 761                                       int sectors_ind,
 762                                       int tottime_ind,
 763                                       int tottimeps_ind,
 764                                       int strtime_ind,
 765                                       int irqtime_ind,
 766                                       int irqtimeps_ind,
 767                                       int endtime_ind)
 768 {
 769         /* in case of an overflow, reset the whole profile */
 770         if (data->dasd_io_reqs == UINT_MAX) {
 771                         memset(data, 0, sizeof(*data));
 772                         getnstimeofday(&data->starttod);
 773         }
 774         data->dasd_io_reqs++;
 775         data->dasd_io_sects += sectors;
 776         if (is_alias)
 777                 data->dasd_io_alias++;
 778         if (is_tpm)
 779                 data->dasd_io_tpm++;
 780
 781         data->dasd_io_secs[sectors_ind]++;
 782         data->dasd_io_times[tottime_ind]++;
 783         data->dasd_io_timps[tottimeps_ind]++;
 784         data->dasd_io_time1[strtime_ind]++;
 785         data->dasd_io_time2[irqtime_ind]++;
 786         data->dasd_io_time2ps[irqtimeps_ind]++;
 787         data->dasd_io_time3[endtime_ind]++;
 788
 789         if (is_read) {
 790                 data->dasd_read_reqs++;
 791                 data->dasd_read_sects += sectors;
 792                 if (is_alias)
 793                         data->dasd_read_alias++;
 794                 if (is_tpm)
 795                         data->dasd_read_tpm++;
 796                 data->dasd_read_secs[sectors_ind]++;
 797                 data->dasd_read_times[tottime_ind]++;
 798                 data->dasd_read_time1[strtime_ind]++;
 799                 data->dasd_read_time2[irqtime_ind]++;
 800                 data->dasd_read_time3[endtime_ind]++;
 801         }
 802 }
 803
 804 static void dasd_profile_end(struct dasd_block *block,
 805                              struct dasd_ccw_req *cqr,
 806                              struct request *req)
 807 {
 808         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 809         long tottimeps, sectors;
 810         struct dasd_device *device;
 811         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 812         int irqtime_ind, irqtimeps_ind, endtime_ind;
 813
 814         device = cqr->startdev;
 815         if (!(dasd_global_profile_level ||
 816               block->profile.data ||
 817               device->profile.data))
 818                 return;
 819
 820         sectors = blk_rq_sectors(req);
 821         if (!cqr->buildclk || !cqr->startclk ||
 822             !cqr->stopclk || !cqr->endclk ||
 823             !sectors)
 824                 return;
 825
 826         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 827         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 828         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 829         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 830         tottimeps = tottime / sectors;
 831
 832         dasd_profile_counter(sectors, sectors_ind);
 833         dasd_profile_counter(tottime, tottime_ind);
 834         dasd_profile_counter(tottimeps, tottimeps_ind);
 835         dasd_profile_counter(strtime, strtime_ind);
 836         dasd_profile_counter(irqtime, irqtime_ind);
 837         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 838         dasd_profile_counter(endtime, endtime_ind);
 839
 840         spin_lock(&dasd_global_profile.lock);
 841         if (dasd_global_profile.data) {
 842                 dasd_profile_end_add_data(dasd_global_profile.data,
 843                                           cqr->startdev != block->base,
 844                                           cqr->cpmode == 1,
 845                                           rq_data_dir(req) == READ,
 846                                           sectors, sectors_ind, tottime_ind,
 847                                           tottimeps_ind, strtime_ind,
 848                                           irqtime_ind, irqtimeps_ind,
 849                                           endtime_ind);
 850         }
 851         spin_unlock(&dasd_global_profile.lock);
 852
 853         spin_lock(&block->profile.lock);
 854         if (block->profile.data)
 855                 dasd_profile_end_add_data(block->profile.data,
 856                                           cqr->startdev != block->base,
 857                                           cqr->cpmode == 1,
 858                                           rq_data_dir(req) == READ,
 859                                           sectors, sectors_ind, tottime_ind,
 860                                           tottimeps_ind, strtime_ind,
 861                                           irqtime_ind, irqtimeps_ind,
 862                                           endtime_ind);
 863         spin_unlock(&block->profile.lock);
 864
 865         spin_lock(&device->profile.lock);
 866         if (device->profile.data)
 867                 dasd_profile_end_add_data(device->profile.data,
 868                                           cqr->startdev != block->base,
 869                                           cqr->cpmode == 1,
 870                                           rq_data_dir(req) == READ,
 871                                           sectors, sectors_ind, tottime_ind,
 872                                           tottimeps_ind, strtime_ind,
 873                                           irqtime_ind, irqtimeps_ind,
 874                                           endtime_ind);
 875         spin_unlock(&device->profile.lock);
 876 }
 877
 878 void dasd_profile_reset(struct dasd_profile *profile)
 879 {
 880         struct dasd_profile_info *data;
 881
 882         spin_lock_bh(&profile->lock);
 883         data = profile->data;
 884         if (!data) {
 885                 spin_unlock_bh(&profile->lock);
 886                 return;
 887         }
 888         memset(data, 0, sizeof(*data));
 889         getnstimeofday(&data->starttod);
 890         spin_unlock_bh(&profile->lock);
 891 }
 892
 893 int dasd_profile_on(struct dasd_profile *profile)
 894 {
 895         struct dasd_profile_info *data;
 896
 897         data = kzalloc(sizeof(*data), GFP_KERNEL);
 898         if (!data)
 899                 return -ENOMEM;
 900         spin_lock_bh(&profile->lock);
 901         if (profile->data) {
 902                 spin_unlock_bh(&profile->lock);
 903                 kfree(data);
 904                 return 0;
 905         }
 906         getnstimeofday(&data->starttod);
 907         profile->data = data;
 908         spin_unlock_bh(&profile->lock);
 909         return 0;
 910 }
 911
 912 void dasd_profile_off(struct dasd_profile *profile)
 913 {
 914         spin_lock_bh(&profile->lock);
 915         kfree(profile->data);
 916         profile->data = NULL;
 917         spin_unlock_bh(&profile->lock);
 918 }
 919
 920 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 921 {
 922         char *buffer;
 923
 924         buffer = vmalloc(user_len + 1);
 925         if (buffer == NULL)
 926                 return ERR_PTR(-ENOMEM);
 927         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 928                 vfree(buffer);
 929                 return ERR_PTR(-EFAULT);
 930         }
 931         /* got the string, now strip linefeed. */
 932         if (buffer[user_len - 1] == '\n')
 933                 buffer[user_len - 1] = 0;
 934         else
 935                 buffer[user_len] = 0;
 936         return buffer;
 937 }
 938
 939 static ssize_t dasd_stats_write(struct file *file,
 940                                 const char __user *user_buf,
 941                                 size_t user_len, loff_t *pos)
 942 {
 943         char *buffer, *str;
 944         int rc;
 945         struct seq_file *m = (struct seq_file *)file->private_data;
 946         struct dasd_profile *prof = m->private;
 947
 948         if (user_len > 65536)
 949                 user_len = 65536;
 950         buffer = dasd_get_user_string(user_buf, user_len);
 951         if (IS_ERR(buffer))
 952                 return PTR_ERR(buffer);
 953
 954         str = skip_spaces(buffer);
 955         rc = user_len;
 956         if (strncmp(str, "reset", 5) == 0) {
 957                 dasd_profile_reset(prof);
 958         } else if (strncmp(str, "on", 2) == 0) {
 959                 rc = dasd_profile_on(prof);
 960                 if (rc)
 961                         goto out;
 962                 rc = user_len;
 963                 if (prof == &dasd_global_profile) {
 964                         dasd_profile_reset(prof);
 965                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 966                 }
 967         } else if (strncmp(str, "off", 3) == 0) {
 968                 if (prof == &dasd_global_profile)
 969                         dasd_global_profile_level = DASD_PROFILE_OFF;
 970                 dasd_profile_off(prof);
 971         } else
 972                 rc = -EINVAL;
 973 out:
 974         vfree(buffer);
 975         return rc;
 976 }
 977
 978 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 979 {
 980         int i;
 981
 982         for (i = 0; i < 32; i++)
 983                 seq_printf(m, "%u ", array[i]);
 984         seq_putc(m, '\n');
 985 }
 986
 987 static void dasd_stats_seq_print(struct seq_file *m,
 988                                  struct dasd_profile_info *data)
 989 {
 990         seq_printf(m, "start_time %ld.%09ld\n",
 991                    data->starttod.tv_sec, data->starttod.tv_nsec);
 992         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 993         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 994         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 995         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 996         seq_puts(m, "histogram_sectors ");
 997         dasd_stats_array(m, data->dasd_io_secs);
 998         seq_puts(m, "histogram_io_times ");
 999         dasd_stats_array(m, data->dasd_io_times);
1000         seq_puts(m, "histogram_io_times_weighted ");
1001         dasd_stats_array(m, data->dasd_io_timps);
1002         seq_puts(m, "histogram_time_build_to_ssch ");
1003         dasd_stats_array(m, data->dasd_io_time1);
1004         seq_puts(m, "histogram_time_ssch_to_irq ");
1005         dasd_stats_array(m, data->dasd_io_time2);
1006         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1007         dasd_stats_array(m, data->dasd_io_time2ps);
1008         seq_puts(m, "histogram_time_irq_to_end ");
1009         dasd_stats_array(m, data->dasd_io_time3);
1010         seq_puts(m, "histogram_ccw_queue_length ");
1011         dasd_stats_array(m, data->dasd_io_nr_req);
1012         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1013         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1014         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1015         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1016         seq_puts(m, "histogram_read_sectors ");
1017         dasd_stats_array(m, data->dasd_read_secs);
1018         seq_puts(m, "histogram_read_times ");
1019         dasd_stats_array(m, data->dasd_read_times);
1020         seq_puts(m, "histogram_read_time_build_to_ssch ");
1021         dasd_stats_array(m, data->dasd_read_time1);
1022         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1023         dasd_stats_array(m, data->dasd_read_time2);
1024         seq_puts(m, "histogram_read_time_irq_to_end ");
1025         dasd_stats_array(m, data->dasd_read_time3);
1026         seq_puts(m, "histogram_read_ccw_queue_length ");
1027         dasd_stats_array(m, data->dasd_read_nr_req);
1028 }
1029
1030 static int dasd_stats_show(struct seq_file *m, void *v)
1031 {
1032         struct dasd_profile *profile;
1033         struct dasd_profile_info *data;
1034
1035         profile = m->private;
1036         spin_lock_bh(&profile->lock);
1037         data = profile->data;
1038         if (!data) {
1039                 spin_unlock_bh(&profile->lock);
1040                 seq_puts(m, "disabled\n");
1041                 return 0;
1042         }
1043         dasd_stats_seq_print(m, data);
1044         spin_unlock_bh(&profile->lock);
1045         return 0;
1046 }
1047
1048 static int dasd_stats_open(struct inode *inode, struct file *file)
1049 {
1050         struct dasd_profile *profile = inode->i_private;
1051         return single_open(file, dasd_stats_show, profile);
1052 }
1053
1054 static const struct file_operations dasd_stats_raw_fops = {
1055         .owner          = THIS_MODULE,
1056         .open           = dasd_stats_open,
1057         .read           = seq_read,
1058         .llseek         = seq_lseek,
1059         .release        = single_release,
1060         .write          = dasd_stats_write,
1061 };
1062
1063 static void dasd_profile_init(struct dasd_profile *profile,
1064                               struct dentry *base_dentry)
1065 {
1066         umode_t mode;
1067         struct dentry *pde;
1068
1069         if (!base_dentry)
1070                 return;
1071         profile->dentry = NULL;
1072         profile->data = NULL;
1073         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1074         pde = debugfs_create_file("statistics", mode, base_dentry,
1075                                   profile, &dasd_stats_raw_fops);
1076         if (pde && !IS_ERR(pde))
1077                 profile->dentry = pde;
1078         return;
1079 }
1080
1081 static void dasd_profile_exit(struct dasd_profile *profile)
1082 {
1083         dasd_profile_off(profile);
1084         debugfs_remove(profile->dentry);
1085         profile->dentry = NULL;
1086 }
1087
1088 static void dasd_statistics_removeroot(void)
1089 {
1090         dasd_global_profile_level = DASD_PROFILE_OFF;
1091         dasd_profile_exit(&dasd_global_profile);
1092         debugfs_remove(dasd_debugfs_global_entry);
1093         debugfs_remove(dasd_debugfs_root_entry);
1094 }
1095
1096 static void dasd_statistics_createroot(void)
1097 {
1098         struct dentry *pde;
1099
1100         dasd_debugfs_root_entry = NULL;
1101         pde = debugfs_create_dir("dasd", NULL);
1102         if (!pde || IS_ERR(pde))
1103                 goto error;
1104         dasd_debugfs_root_entry = pde;
1105         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1106         if (!pde || IS_ERR(pde))
1107                 goto error;
1108         dasd_debugfs_global_entry = pde;
1109         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1110         return;
1111
1112 error:
1113         DBF_EVENT(DBF_ERR, "%s",
1114                   "Creation of the dasd debugfs interface failed");
1115         dasd_statistics_removeroot();
1116         return;
1117 }
1118
1119 #else
1120 #define dasd_profile_start(block, cqr, req) do {} while (0)
1121 #define dasd_profile_end(block, cqr, req) do {} while (0)
1122
1123 static void dasd_statistics_createroot(void)
1124 {
1125         return;
1126 }
1127
1128 static void dasd_statistics_removeroot(void)
1129 {
1130         return;
1131 }
1132
1133 int dasd_stats_generic_show(struct seq_file *m, void *v)
1134 {
1135         seq_puts(m, "Statistics are not activated in this kernel\n");
1136         return 0;
1137 }
1138
1139 static void dasd_profile_init(struct dasd_profile *profile,
1140                               struct dentry *base_dentry)
1141 {
1142         return;
1143 }
1144
1145 static void dasd_profile_exit(struct dasd_profile *profile)
1146 {
1147         return;
1148 }
1149
1150 int dasd_profile_on(struct dasd_profile *profile)
1151 {
1152         return 0;
1153 }
1154
1155 #endif                          /* CONFIG_DASD_PROFILE */
1156
1157 static int dasd_hosts_show(struct seq_file *m, void *v)
1158 {
1159         struct dasd_device *device;
1160         int rc = -EOPNOTSUPP;
1161
1162         device = m->private;
1163         dasd_get_device(device);
1164
1165         if (device->discipline->hosts_print)
1166                 rc = device->discipline->hosts_print(device, m);
1167
1168         dasd_put_device(device);
1169         return rc;
1170 }
1171
1172 static int dasd_hosts_open(struct inode *inode, struct file *file)
1173 {
1174         struct dasd_device *device = inode->i_private;
1175
1176         return single_open(file, dasd_hosts_show, device);
1177 }
1178
1179 static const struct file_operations dasd_hosts_fops = {
1180         .owner          = THIS_MODULE,
1181         .open           = dasd_hosts_open,
1182         .read           = seq_read,
1183         .llseek         = seq_lseek,
1184         .release        = single_release,
1185 };
1186
1187 static void dasd_hosts_exit(struct dasd_device *device)
1188 {
1189         debugfs_remove(device->hosts_dentry);
1190         device->hosts_dentry = NULL;
1191 }
1192
1193 static void dasd_hosts_init(struct dentry *base_dentry,
1194                             struct dasd_device *device)
1195 {
1196         struct dentry *pde;
1197         umode_t mode;
1198
1199         if (!base_dentry)
1200                 return;
1201
1202         mode = S_IRUSR | S_IFREG;
1203         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1204                                   device, &dasd_hosts_fops);
1205         if (pde && !IS_ERR(pde))
1206                 device->hosts_dentry = pde;
1207 }
1208
1209 /*
1210  * Allocate memory for a channel program with 'cplength' channel
1211  * command words and 'datasize' additional space. There are two
1212  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1213  * memory and 2) dasd_smalloc_request uses the static ccw memory
1214  * that gets allocated for each device.
1215  */
1216 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1217                                           int datasize,
1218                                           struct dasd_device *device)
1219 {
1220         struct dasd_ccw_req *cqr;
1221
1222         /* Sanity checks */
1223         BUG_ON(datasize > PAGE_SIZE ||
1224              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1225
1226         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1227         if (cqr == NULL)
1228                 return ERR_PTR(-ENOMEM);
1229         cqr->cpaddr = NULL;
1230         if (cplength > 0) {
1231                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1232                                       GFP_ATOMIC | GFP_DMA);
1233                 if (cqr->cpaddr == NULL) {
1234                         kfree(cqr);
1235                         return ERR_PTR(-ENOMEM);
1236                 }
1237         }
1238         cqr->data = NULL;
1239         if (datasize > 0) {
1240                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1241                 if (cqr->data == NULL) {
1242                         kfree(cqr->cpaddr);
1243                         kfree(cqr);
1244                         return ERR_PTR(-ENOMEM);
1245                 }
1246         }
1247         cqr->magic =  magic;
1248         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1249         dasd_get_device(device);
1250         return cqr;
1251 }
1252 EXPORT_SYMBOL(dasd_kmalloc_request);
1253
1254 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1255                                           int datasize,
1256                                           struct dasd_device *device)
1257 {
1258         unsigned long flags;
1259         struct dasd_ccw_req *cqr;
1260         char *data;
1261         int size;
1262
1263         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1264         if (cplength > 0)
1265                 size += cplength * sizeof(struct ccw1);
1266         if (datasize > 0)
1267                 size += datasize;
1268         spin_lock_irqsave(&device->mem_lock, flags);
1269         cqr = (struct dasd_ccw_req *)
1270                 dasd_alloc_chunk(&device->ccw_chunks, size);
1271         spin_unlock_irqrestore(&device->mem_lock, flags);
1272         if (cqr == NULL)
1273                 return ERR_PTR(-ENOMEM);
1274         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1275         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1276         cqr->cpaddr = NULL;
1277         if (cplength > 0) {
1278                 cqr->cpaddr = (struct ccw1 *) data;
1279                 data += cplength*sizeof(struct ccw1);
1280                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1281         }
1282         cqr->data = NULL;
1283         if (datasize > 0) {
1284                 cqr->data = data;
1285                 memset(cqr->data, 0, datasize);
1286         }
1287         cqr->magic = magic;
1288         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1289         dasd_get_device(device);
1290         return cqr;
1291 }
1292 EXPORT_SYMBOL(dasd_smalloc_request);
1293
1294 /*
1295  * Free memory of a channel program. This function needs to free all the
1296  * idal lists that might have been created by dasd_set_cda and the
1297  * struct dasd_ccw_req itself.
1298  */
1299 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1300 {
1301         struct ccw1 *ccw;
1302
1303         /* Clear any idals used for the request. */
1304         ccw = cqr->cpaddr;
1305         do {
1306                 clear_normalized_cda(ccw);
1307         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1308         kfree(cqr->cpaddr);
1309         kfree(cqr->data);
1310         kfree(cqr);
1311         dasd_put_device(device);
1312 }
1313 EXPORT_SYMBOL(dasd_kfree_request);
1314
1315 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1316 {
1317         unsigned long flags;
1318
1319         spin_lock_irqsave(&device->mem_lock, flags);
1320         dasd_free_chunk(&device->ccw_chunks, cqr);
1321         spin_unlock_irqrestore(&device->mem_lock, flags);
1322         dasd_put_device(device);
1323 }
1324 EXPORT_SYMBOL(dasd_sfree_request);
1325
1326 /*
1327  * Check discipline magic in cqr.
1328  */
1329 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1330 {
1331         struct dasd_device *device;
1332
1333         if (cqr == NULL)
1334                 return -EINVAL;
1335         device = cqr->startdev;
1336         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1337                 DBF_DEV_EVENT(DBF_WARNING, device,
1338                             " dasd_ccw_req 0x%08x magic doesn't match"
1339                             " discipline 0x%08x",
1340                             cqr->magic,
1341                             *(unsigned int *) device->discipline->name);
1342                 return -EINVAL;
1343         }
1344         return 0;
1345 }
1346
1347 /*
1348  * Terminate the current i/o and set the request to clear_pending.
1349  * Timer keeps device runnig.
1350  * ccw_device_clear can fail if the i/o subsystem
1351  * is in a bad mood.
1352  */
1353 int dasd_term_IO(struct dasd_ccw_req *cqr)
1354 {
1355         struct dasd_device *device;
1356         int retries, rc;
1357         char errorstring[ERRORLENGTH];
1358
1359         /* Check the cqr */
1360         rc = dasd_check_cqr(cqr);
1361         if (rc)
1362                 return rc;
1363         retries = 0;
1364         device = (struct dasd_device *) cqr->startdev;
1365         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1366                 rc = ccw_device_clear(device->cdev, (long) cqr);
1367                 switch (rc) {
1368                 case 0: /* termination successful */
1369                         cqr->status = DASD_CQR_CLEAR_PENDING;
1370                         cqr->stopclk = get_tod_clock();
1371                         cqr->starttime = 0;
1372                         DBF_DEV_EVENT(DBF_DEBUG, device,
1373                                       "terminate cqr %p successful",
1374                                       cqr);
1375                         break;
1376                 case -ENODEV:
1377                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1378                                       "device gone, retry");
1379                         break;
1380                 case -EIO:
1381                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1382                                       "I/O error, retry");
1383                         break;
1384                 case -EINVAL:
1385                         /*
1386                          * device not valid so no I/O could be running
1387                          * handle CQR as termination successful
1388                          */
1389                         cqr->status = DASD_CQR_CLEARED;
1390                         cqr->stopclk = get_tod_clock();
1391                         cqr->starttime = 0;
1392                         /* no retries for invalid devices */
1393                         cqr->retries = -1;
1394                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1395                                       "EINVAL, handle as terminated");
1396                         /* fake rc to success */
1397                         rc = 0;
1398                         break;
1399                 case -EBUSY:
1400                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1401                                       "device busy, retry later");
1402                         break;
1403                 default:
1404                         /* internal error 10 - unknown rc*/
1405                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1406                         dev_err(&device->cdev->dev, "An error occurred in the "
1407                                 "DASD device driver, reason=%s\n", errorstring);
1408                         BUG();
1409                         break;
1410                 }
1411                 retries++;
1412         }
1413         dasd_schedule_device_bh(device);
1414         return rc;
1415 }
1416 EXPORT_SYMBOL(dasd_term_IO);
1417
1418 /*
1419  * Start the i/o. This start_IO can fail if the channel is really busy.
1420  * In that case set up a timer to start the request later.
1421  */
1422 int dasd_start_IO(struct dasd_ccw_req *cqr)
1423 {
1424         struct dasd_device *device;
1425         int rc;
1426         char errorstring[ERRORLENGTH];
1427
1428         /* Check the cqr */
1429         rc = dasd_check_cqr(cqr);
1430         if (rc) {
1431                 cqr->intrc = rc;
1432                 return rc;
1433         }
1434         device = (struct dasd_device *) cqr->startdev;
1435         if (((cqr->block &&
1436               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1437              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1438             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1439                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1440                               "because of stolen lock", cqr);
1441                 cqr->status = DASD_CQR_ERROR;
1442                 cqr->intrc = -EPERM;
1443                 return -EPERM;
1444         }
1445         if (cqr->retries < 0) {
1446                 /* internal error 14 - start_IO run out of retries */
1447                 sprintf(errorstring, "14 %p", cqr);
1448                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1449                         "device driver, reason=%s\n", errorstring);
1450                 cqr->status = DASD_CQR_ERROR;
1451                 return -EIO;
1452         }
1453         cqr->startclk = get_tod_clock();
1454         cqr->starttime = jiffies;
1455         cqr->retries--;
1456         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1457                 cqr->lpm &= device->path_data.opm;
1458                 if (!cqr->lpm)
1459                         cqr->lpm = device->path_data.opm;
1460         }
1461         if (cqr->cpmode == 1) {
1462                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1463                                          (long) cqr, cqr->lpm);
1464         } else {
1465                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1466                                       (long) cqr, cqr->lpm, 0);
1467         }
1468         switch (rc) {
1469         case 0:
1470                 cqr->status = DASD_CQR_IN_IO;
1471                 break;
1472         case -EBUSY:
1473                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1474                               "start_IO: device busy, retry later");
1475                 break;
1476         case -ETIMEDOUT:
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: request timeout, retry later");
1479                 break;
1480         case -EACCES:
1481                 /* -EACCES indicates that the request used only a subset of the
1482                  * available paths and all these paths are gone. If the lpm of
1483                  * this request was only a subset of the opm (e.g. the ppm) then
1484                  * we just do a retry with all available paths.
1485                  * If we already use the full opm, something is amiss, and we
1486                  * need a full path verification.
1487                  */
1488                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1489                         DBF_DEV_EVENT(DBF_WARNING, device,
1490                                       "start_IO: selected paths gone (%x)",
1491                                       cqr->lpm);
1492                 } else if (cqr->lpm != device->path_data.opm) {
1493                         cqr->lpm = device->path_data.opm;
1494                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1495                                       "start_IO: selected paths gone,"
1496                                       " retry on all paths");
1497                 } else {
1498                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1499                                       "start_IO: all paths in opm gone,"
1500                                       " do path verification");
1501                         dasd_generic_last_path_gone(device);
1502                         device->path_data.opm = 0;
1503                         device->path_data.ppm = 0;
1504                         device->path_data.npm = 0;
1505                         device->path_data.tbvpm =
1506                                 ccw_device_get_path_mask(device->cdev);
1507                 }
1508                 break;
1509         case -ENODEV:
1510                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1511                               "start_IO: -ENODEV device gone, retry");
1512                 break;
1513         case -EIO:
1514                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1515                               "start_IO: -EIO device gone, retry");
1516                 break;
1517         case -EINVAL:
1518                 /* most likely caused in power management context */
1519                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1520                               "start_IO: -EINVAL device currently "
1521                               "not accessible");
1522                 break;
1523         default:
1524                 /* internal error 11 - unknown rc */
1525                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1526                 dev_err(&device->cdev->dev,
1527                         "An error occurred in the DASD device driver, "
1528                         "reason=%s\n", errorstring);
1529                 BUG();
1530                 break;
1531         }
1532         cqr->intrc = rc;
1533         return rc;
1534 }
1535 EXPORT_SYMBOL(dasd_start_IO);
1536
1537 /*
1538  * Timeout function for dasd devices. This is used for different purposes
1539  *  1) missing interrupt handler for normal operation
1540  *  2) delayed start of request where start_IO failed with -EBUSY
1541  *  3) timeout for missing state change interrupts
1542  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1543  * DASD_CQR_QUEUED for 2) and 3).
1544  */
1545 static void dasd_device_timeout(unsigned long ptr)
1546 {
1547         unsigned long flags;
1548         struct dasd_device *device;
1549
1550         device = (struct dasd_device *) ptr;
1551         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1552         /* re-activate request queue */
1553         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1554         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1555         dasd_schedule_device_bh(device);
1556 }
1557
1558 /*
1559  * Setup timeout for a device in jiffies.
1560  */
1561 void dasd_device_set_timer(struct dasd_device *device, int expires)
1562 {
1563         if (expires == 0)
1564                 del_timer(&device->timer);
1565         else
1566                 mod_timer(&device->timer, jiffies + expires);
1567 }
1568 EXPORT_SYMBOL(dasd_device_set_timer);
1569
1570 /*
1571  * Clear timeout for a device.
1572  */
1573 void dasd_device_clear_timer(struct dasd_device *device)
1574 {
1575         del_timer(&device->timer);
1576 }
1577 EXPORT_SYMBOL(dasd_device_clear_timer);
1578
1579 static void dasd_handle_killed_request(struct ccw_device *cdev,
1580                                        unsigned long intparm)
1581 {
1582         struct dasd_ccw_req *cqr;
1583         struct dasd_device *device;
1584
1585         if (!intparm)
1586                 return;
1587         cqr = (struct dasd_ccw_req *) intparm;
1588         if (cqr->status != DASD_CQR_IN_IO) {
1589                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1590                                 "invalid status in handle_killed_request: "
1591                                 "%02x", cqr->status);
1592                 return;
1593         }
1594
1595         device = dasd_device_from_cdev_locked(cdev);
1596         if (IS_ERR(device)) {
1597                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1598                                 "unable to get device from cdev");
1599                 return;
1600         }
1601
1602         if (!cqr->startdev ||
1603             device != cqr->startdev ||
1604             strncmp(cqr->startdev->discipline->ebcname,
1605                     (char *) &cqr->magic, 4)) {
1606                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1607                                 "invalid device in request");
1608                 dasd_put_device(device);
1609                 return;
1610         }
1611
1612         /* Schedule request to be retried. */
1613         cqr->status = DASD_CQR_QUEUED;
1614
1615         dasd_device_clear_timer(device);
1616         dasd_schedule_device_bh(device);
1617         dasd_put_device(device);
1618 }
1619
1620 void dasd_generic_handle_state_change(struct dasd_device *device)
1621 {
1622         /* First of all start sense subsystem status request. */
1623         dasd_eer_snss(device);
1624
1625         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1626         dasd_schedule_device_bh(device);
1627         if (device->block)
1628                 dasd_schedule_block_bh(device->block);
1629 }
1630 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1631
1632 /*
1633  * Interrupt handler for "normal" ssch-io based dasd devices.
1634  */
1635 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1636                       struct irb *irb)
1637 {
1638         struct dasd_ccw_req *cqr, *next;
1639         struct dasd_device *device;
1640         unsigned long long now;
1641         int nrf_suppressed = 0;
1642         int fp_suppressed = 0;
1643         u8 *sense = NULL;
1644         int expires;
1645
1646         cqr = (struct dasd_ccw_req *) intparm;
1647         if (IS_ERR(irb)) {
1648                 switch (PTR_ERR(irb)) {
1649                 case -EIO:
1650                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1651                                 device = (struct dasd_device *) cqr->startdev;
1652                                 cqr->status = DASD_CQR_CLEARED;
1653                                 dasd_device_clear_timer(device);
1654                                 wake_up(&dasd_flush_wq);
1655                                 dasd_schedule_device_bh(device);
1656                                 return;
1657                         }
1658                         break;
1659                 case -ETIMEDOUT:
1660                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1661                                         "request timed out\n", __func__);
1662                         break;
1663                 default:
1664                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1665                                         "unknown error %ld\n", __func__,
1666                                         PTR_ERR(irb));
1667                 }
1668                 dasd_handle_killed_request(cdev, intparm);
1669                 return;
1670         }
1671
1672         now = get_tod_clock();
1673         /* check for conditions that should be handled immediately */
1674         if (!cqr ||
1675             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1676               scsw_cstat(&irb->scsw) == 0)) {
1677                 if (cqr)
1678                         memcpy(&cqr->irb, irb, sizeof(*irb));
1679                 device = dasd_device_from_cdev_locked(cdev);
1680                 if (IS_ERR(device))
1681                         return;
1682                 /* ignore unsolicited interrupts for DIAG discipline */
1683                 if (device->discipline == dasd_diag_discipline_pointer) {
1684                         dasd_put_device(device);
1685                         return;
1686                 }
1687
1688                 /*
1689                  * In some cases 'File Protected' or 'No Record Found' errors
1690                  * might be expected and debug log messages for the
1691                  * corresponding interrupts shouldn't be written then.
1692                  * Check if either of the according suppress bits is set.
1693                  */
1694                 sense = dasd_get_sense(irb);
1695                 if (sense) {
1696                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1697                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1698                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1699                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1700                 }
1701                 if (!(fp_suppressed || nrf_suppressed))
1702                         device->discipline->dump_sense_dbf(device, irb, "int");
1703
1704                 if (device->features & DASD_FEATURE_ERPLOG)
1705                         device->discipline->dump_sense(device, cqr, irb);
1706                 device->discipline->check_for_device_change(device, cqr, irb);
1707                 dasd_put_device(device);
1708         }
1709
1710         /* check for for attention message */
1711         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1712                 device = dasd_device_from_cdev_locked(cdev);
1713                 device->discipline->check_attention(device, irb->esw.esw1.lpum);
1714                 dasd_put_device(device);
1715         }
1716
1717         if (!cqr)
1718                 return;
1719
1720         device = (struct dasd_device *) cqr->startdev;
1721         if (!device ||
1722             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1723                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1724                                 "invalid device in request");
1725                 return;
1726         }
1727
1728         /* Check for clear pending */
1729         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1730             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1731                 cqr->status = DASD_CQR_CLEARED;
1732                 dasd_device_clear_timer(device);
1733                 wake_up(&dasd_flush_wq);
1734                 dasd_schedule_device_bh(device);
1735                 return;
1736         }
1737
1738         /* check status - the request might have been killed by dyn detach */
1739         if (cqr->status != DASD_CQR_IN_IO) {
1740                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1741                               "status %02x", dev_name(&cdev->dev), cqr->status);
1742                 return;
1743         }
1744
1745         next = NULL;
1746         expires = 0;
1747         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1748             scsw_cstat(&irb->scsw) == 0) {
1749                 /* request was completed successfully */
1750                 cqr->status = DASD_CQR_SUCCESS;
1751                 cqr->stopclk = now;
1752                 /* Start first request on queue if possible -> fast_io. */
1753                 if (cqr->devlist.next != &device->ccw_queue) {
1754                         next = list_entry(cqr->devlist.next,
1755                                           struct dasd_ccw_req, devlist);
1756                 }
1757         } else {  /* error */
1758                 /*
1759                  * If we don't want complex ERP for this request, then just
1760                  * reset this and retry it in the fastpath
1761                  */
1762                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1763                     cqr->retries > 0) {
1764                         if (cqr->lpm == device->path_data.opm)
1765                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1766                                               "default ERP in fastpath "
1767                                               "(%i retries left)",
1768                                               cqr->retries);
1769                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1770                                 cqr->lpm = device->path_data.opm;
1771                         cqr->status = DASD_CQR_QUEUED;
1772                         next = cqr;
1773                 } else
1774                         cqr->status = DASD_CQR_ERROR;
1775         }
1776         if (next && (next->status == DASD_CQR_QUEUED) &&
1777             (!device->stopped)) {
1778                 if (device->discipline->start_IO(next) == 0)
1779                         expires = next->expires;
1780         }
1781         if (expires != 0)
1782                 dasd_device_set_timer(device, expires);
1783         else
1784                 dasd_device_clear_timer(device);
1785         dasd_schedule_device_bh(device);
1786 }
1787 EXPORT_SYMBOL(dasd_int_handler);
1788
1789 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1790 {
1791         struct dasd_device *device;
1792
1793         device = dasd_device_from_cdev_locked(cdev);
1794
1795         if (IS_ERR(device))
1796                 goto out;
1797         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1798            device->state != device->target ||
1799            !device->discipline->check_for_device_change){
1800                 dasd_put_device(device);
1801                 goto out;
1802         }
1803         if (device->discipline->dump_sense_dbf)
1804                 device->discipline->dump_sense_dbf(device, irb, "uc");
1805         device->discipline->check_for_device_change(device, NULL, irb);
1806         dasd_put_device(device);
1807 out:
1808         return UC_TODO_RETRY;
1809 }
1810 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1811
1812 /*
1813  * If we have an error on a dasd_block layer request then we cancel
1814  * and return all further requests from the same dasd_block as well.
1815  */
1816 static void __dasd_device_recovery(struct dasd_device *device,
1817                                    struct dasd_ccw_req *ref_cqr)
1818 {
1819         struct list_head *l, *n;
1820         struct dasd_ccw_req *cqr;
1821
1822         /*
1823          * only requeue request that came from the dasd_block layer
1824          */
1825         if (!ref_cqr->block)
1826                 return;
1827
1828         list_for_each_safe(l, n, &device->ccw_queue) {
1829                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1830                 if (cqr->status == DASD_CQR_QUEUED &&
1831                     ref_cqr->block == cqr->block) {
1832                         cqr->status = DASD_CQR_CLEARED;
1833                 }
1834         }
1835 };
1836
1837 /*
1838  * Remove those ccw requests from the queue that need to be returned
1839  * to the upper layer.
1840  */
1841 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1842                                             struct list_head *final_queue)
1843 {
1844         struct list_head *l, *n;
1845         struct dasd_ccw_req *cqr;
1846
1847         /* Process request with final status. */
1848         list_for_each_safe(l, n, &device->ccw_queue) {
1849                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1850
1851                 /* Skip any non-final request. */
1852                 if (cqr->status == DASD_CQR_QUEUED ||
1853                     cqr->status == DASD_CQR_IN_IO ||
1854                     cqr->status == DASD_CQR_CLEAR_PENDING)
1855                         continue;
1856                 if (cqr->status == DASD_CQR_ERROR) {
1857                         __dasd_device_recovery(device, cqr);
1858                 }
1859                 /* Rechain finished requests to final queue */
1860                 list_move_tail(&cqr->devlist, final_queue);
1861         }
1862 }
1863
1864 /*
1865  * the cqrs from the final queue are returned to the upper layer
1866  * by setting a dasd_block state and calling the callback function
1867  */
1868 static void __dasd_device_process_final_queue(struct dasd_device *device,
1869                                               struct list_head *final_queue)
1870 {
1871         struct list_head *l, *n;
1872         struct dasd_ccw_req *cqr;
1873         struct dasd_block *block;
1874         void (*callback)(struct dasd_ccw_req *, void *data);
1875         void *callback_data;
1876         char errorstring[ERRORLENGTH];
1877
1878         list_for_each_safe(l, n, final_queue) {
1879                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1880                 list_del_init(&cqr->devlist);
1881                 block = cqr->block;
1882                 callback = cqr->callback;
1883                 callback_data = cqr->callback_data;
1884                 if (block)
1885                         spin_lock_bh(&block->queue_lock);
1886                 switch (cqr->status) {
1887                 case DASD_CQR_SUCCESS:
1888                         cqr->status = DASD_CQR_DONE;
1889                         break;
1890                 case DASD_CQR_ERROR:
1891                         cqr->status = DASD_CQR_NEED_ERP;
1892                         break;
1893                 case DASD_CQR_CLEARED:
1894                         cqr->status = DASD_CQR_TERMINATED;
1895                         break;
1896                 default:
1897                         /* internal error 12 - wrong cqr status*/
1898                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1899                         dev_err(&device->cdev->dev,
1900                                 "An error occurred in the DASD device driver, "
1901                                 "reason=%s\n", errorstring);
1902                         BUG();
1903                 }
1904                 if (cqr->callback != NULL)
1905                         (callback)(cqr, callback_data);
1906                 if (block)
1907                         spin_unlock_bh(&block->queue_lock);
1908         }
1909 }
1910
1911 /*
1912  * Take a look at the first request on the ccw queue and check
1913  * if it reached its expire time. If so, terminate the IO.
1914  */
1915 static void __dasd_device_check_expire(struct dasd_device *device)
1916 {
1917         struct dasd_ccw_req *cqr;
1918
1919         if (list_empty(&device->ccw_queue))
1920                 return;
1921         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1922         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1923             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1924                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1925                         /*
1926                          * IO in safe offline processing should not
1927                          * run out of retries
1928                          */
1929                         cqr->retries++;
1930                 }
1931                 if (device->discipline->term_IO(cqr) != 0) {
1932                         /* Hmpf, try again in 5 sec */
1933                         dev_err(&device->cdev->dev,
1934                                 "cqr %p timed out (%lus) but cannot be "
1935                                 "ended, retrying in 5 s\n",
1936                                 cqr, (cqr->expires/HZ));
1937                         cqr->expires += 5*HZ;
1938                         dasd_device_set_timer(device, 5*HZ);
1939                 } else {
1940                         dev_err(&device->cdev->dev,
1941                                 "cqr %p timed out (%lus), %i retries "
1942                                 "remaining\n", cqr, (cqr->expires/HZ),
1943                                 cqr->retries);
1944                 }
1945         }
1946 }
1947
1948 /*
1949  * return 1 when device is not eligible for IO
1950  */
1951 static int __dasd_device_is_unusable(struct dasd_device *device,
1952                                      struct dasd_ccw_req *cqr)
1953 {
1954         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1955
1956         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1957                 /* dasd is being set offline. */
1958                 return 1;
1959         }
1960         if (device->stopped) {
1961                 if (device->stopped & mask) {
1962                         /* stopped and CQR will not change that. */
1963                         return 1;
1964                 }
1965                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1966                         /* CQR is not able to change device to
1967                          * operational. */
1968                         return 1;
1969                 }
1970                 /* CQR required to get device operational. */
1971         }
1972         return 0;
1973 }
1974
1975 /*
1976  * Take a look at the first request on the ccw queue and check
1977  * if it needs to be started.
1978  */
1979 static void __dasd_device_start_head(struct dasd_device *device)
1980 {
1981         struct dasd_ccw_req *cqr;
1982         int rc;
1983
1984         if (list_empty(&device->ccw_queue))
1985                 return;
1986         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1987         if (cqr->status != DASD_CQR_QUEUED)
1988                 return;
1989         /* if device is not usable return request to upper layer */
1990         if (__dasd_device_is_unusable(device, cqr)) {
1991                 cqr->intrc = -EAGAIN;
1992                 cqr->status = DASD_CQR_CLEARED;
1993                 dasd_schedule_device_bh(device);
1994                 return;
1995         }
1996
1997         rc = device->discipline->start_IO(cqr);
1998         if (rc == 0)
1999                 dasd_device_set_timer(device, cqr->expires);
2000         else if (rc == -EACCES) {
2001                 dasd_schedule_device_bh(device);
2002         } else
2003                 /* Hmpf, try again in 1/2 sec */
2004                 dasd_device_set_timer(device, 50);
2005 }
2006
2007 static void __dasd_device_check_path_events(struct dasd_device *device)
2008 {
2009         int rc;
2010
2011         if (device->path_data.tbvpm) {
2012                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
2013                                         DASD_UNRESUMED_PM))
2014                         return;
2015                 rc = device->discipline->verify_path(
2016                         device, device->path_data.tbvpm);
2017                 if (rc)
2018                         dasd_device_set_timer(device, 50);
2019                 else
2020                         device->path_data.tbvpm = 0;
2021         }
2022 };
2023
2024 /*
2025  * Go through all request on the dasd_device request queue,
2026  * terminate them on the cdev if necessary, and return them to the
2027  * submitting layer via callback.
2028  * Note:
2029  * Make sure that all 'submitting layers' still exist when
2030  * this function is called!. In other words, when 'device' is a base
2031  * device then all block layer requests must have been removed before
2032  * via dasd_flush_block_queue.
2033  */
2034 int dasd_flush_device_queue(struct dasd_device *device)
2035 {
2036         struct dasd_ccw_req *cqr, *n;
2037         int rc;
2038         struct list_head flush_queue;
2039
2040         INIT_LIST_HEAD(&flush_queue);
2041         spin_lock_irq(get_ccwdev_lock(device->cdev));
2042         rc = 0;
2043         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2044                 /* Check status and move request to flush_queue */
2045                 switch (cqr->status) {
2046                 case DASD_CQR_IN_IO:
2047                         rc = device->discipline->term_IO(cqr);
2048                         if (rc) {
2049                                 /* unable to terminate requeust */
2050                                 dev_err(&device->cdev->dev,
2051                                         "Flushing the DASD request queue "
2052                                         "failed for request %p\n", cqr);
2053                                 /* stop flush processing */
2054                                 goto finished;
2055                         }
2056                         break;
2057                 case DASD_CQR_QUEUED:
2058                         cqr->stopclk = get_tod_clock();
2059                         cqr->status = DASD_CQR_CLEARED;
2060                         break;
2061                 default: /* no need to modify the others */
2062                         break;
2063                 }
2064                 list_move_tail(&cqr->devlist, &flush_queue);
2065         }
2066 finished:
2067         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2068         /*
2069          * After this point all requests must be in state CLEAR_PENDING,
2070          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2071          * one of the others.
2072          */
2073         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2074                 wait_event(dasd_flush_wq,
2075                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2076         /*
2077          * Now set each request back to TERMINATED, DONE or NEED_ERP
2078          * and call the callback function of flushed requests
2079          */
2080         __dasd_device_process_final_queue(device, &flush_queue);
2081         return rc;
2082 }
2083 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2084
2085 /*
2086  * Acquire the device lock and process queues for the device.
2087  */
2088 static void dasd_device_tasklet(struct dasd_device *device)
2089 {
2090         struct list_head final_queue;
2091
2092         atomic_set (&device->tasklet_scheduled, 0);
2093         INIT_LIST_HEAD(&final_queue);
2094         spin_lock_irq(get_ccwdev_lock(device->cdev));
2095         /* Check expire time of first request on the ccw queue. */
2096         __dasd_device_check_expire(device);
2097         /* find final requests on ccw queue */
2098         __dasd_device_process_ccw_queue(device, &final_queue);
2099         __dasd_device_check_path_events(device);
2100         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2101         /* Now call the callback function of requests with final status */
2102         __dasd_device_process_final_queue(device, &final_queue);
2103         spin_lock_irq(get_ccwdev_lock(device->cdev));
2104         /* Now check if the head of the ccw queue needs to be started. */
2105         __dasd_device_start_head(device);
2106         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2107         if (waitqueue_active(&shutdown_waitq))
2108                 wake_up(&shutdown_waitq);
2109         dasd_put_device(device);
2110 }
2111
2112 /*
2113  * Schedules a call to dasd_tasklet over the device tasklet.
2114  */
2115 void dasd_schedule_device_bh(struct dasd_device *device)
2116 {
2117         /* Protect against rescheduling. */
2118         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2119                 return;
2120         dasd_get_device(device);
2121         tasklet_hi_schedule(&device->tasklet);
2122 }
2123 EXPORT_SYMBOL(dasd_schedule_device_bh);
2124
2125 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2126 {
2127         device->stopped |= bits;
2128 }
2129 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2130
2131 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2132 {
2133         device->stopped &= ~bits;
2134         if (!device->stopped)
2135                 wake_up(&generic_waitq);
2136 }
2137 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2138
2139 /*
2140  * Queue a request to the head of the device ccw_queue.
2141  * Start the I/O if possible.
2142  */
2143 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2144 {
2145         struct dasd_device *device;
2146         unsigned long flags;
2147
2148         device = cqr->startdev;
2149         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2150         cqr->status = DASD_CQR_QUEUED;
2151         list_add(&cqr->devlist, &device->ccw_queue);
2152         /* let the bh start the request to keep them in order */
2153         dasd_schedule_device_bh(device);
2154         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2155 }
2156 EXPORT_SYMBOL(dasd_add_request_head);
2157
2158 /*
2159  * Queue a request to the tail of the device ccw_queue.
2160  * Start the I/O if possible.
2161  */
2162 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2163 {
2164         struct dasd_device *device;
2165         unsigned long flags;
2166
2167         device = cqr->startdev;
2168         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2169         cqr->status = DASD_CQR_QUEUED;
2170         list_add_tail(&cqr->devlist, &device->ccw_queue);
2171         /* let the bh start the request to keep them in order */
2172         dasd_schedule_device_bh(device);
2173         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2174 }
2175 EXPORT_SYMBOL(dasd_add_request_tail);
2176
2177 /*
2178  * Wakeup helper for the 'sleep_on' functions.
2179  */
2180 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2181 {
2182         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2183         cqr->callback_data = DASD_SLEEPON_END_TAG;
2184         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2185         wake_up(&generic_waitq);
2186 }
2187 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2188
2189 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2190 {
2191         struct dasd_device *device;
2192         int rc;
2193
2194         device = cqr->startdev;
2195         spin_lock_irq(get_ccwdev_lock(device->cdev));
2196         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2197         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2198         return rc;
2199 }
2200
2201 /*
2202  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2203  */
2204 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2205 {
2206         struct dasd_device *device;
2207         dasd_erp_fn_t erp_fn;
2208
2209         if (cqr->status == DASD_CQR_FILLED)
2210                 return 0;
2211         device = cqr->startdev;
2212         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2213                 if (cqr->status == DASD_CQR_TERMINATED) {
2214                         device->discipline->handle_terminated_request(cqr);
2215                         return 1;
2216                 }
2217                 if (cqr->status == DASD_CQR_NEED_ERP) {
2218                         erp_fn = device->discipline->erp_action(cqr);
2219                         erp_fn(cqr);
2220                         return 1;
2221                 }
2222                 if (cqr->status == DASD_CQR_FAILED)
2223                         dasd_log_sense(cqr, &cqr->irb);
2224                 if (cqr->refers) {
2225                         __dasd_process_erp(device, cqr);
2226                         return 1;
2227                 }
2228         }
2229         return 0;
2230 }
2231
2232 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2233 {
2234         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2235                 if (cqr->refers) /* erp is not done yet */
2236                         return 1;
2237                 return ((cqr->status != DASD_CQR_DONE) &&
2238                         (cqr->status != DASD_CQR_FAILED));
2239         } else
2240                 return (cqr->status == DASD_CQR_FILLED);
2241 }
2242
2243 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2244 {
2245         struct dasd_device *device;
2246         int rc;
2247         struct list_head ccw_queue;
2248         struct dasd_ccw_req *cqr;
2249
2250         INIT_LIST_HEAD(&ccw_queue);
2251         maincqr->status = DASD_CQR_FILLED;
2252         device = maincqr->startdev;
2253         list_add(&maincqr->blocklist, &ccw_queue);
2254         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2255              cqr = list_first_entry(&ccw_queue,
2256                                     struct dasd_ccw_req, blocklist)) {
2257
2258                 if (__dasd_sleep_on_erp(cqr))
2259                         continue;
2260                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2261                         continue;
2262                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2263                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2264                         cqr->status = DASD_CQR_FAILED;
2265                         cqr->intrc = -EPERM;
2266                         continue;
2267                 }
2268                 /* Non-temporary stop condition will trigger fail fast */
2269                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2270                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2271                     (!dasd_eer_enabled(device))) {
2272                         cqr->status = DASD_CQR_FAILED;
2273                         cqr->intrc = -ENOLINK;
2274                         continue;
2275                 }
2276                 /*
2277                  * Don't try to start requests if device is stopped
2278                  * except path verification requests
2279                  */
2280                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2281                         if (interruptible) {
2282                                 rc = wait_event_interruptible(
2283                                         generic_waitq, !(device->stopped));
2284                                 if (rc == -ERESTARTSYS) {
2285                                         cqr->status = DASD_CQR_FAILED;
2286                                         maincqr->intrc = rc;
2287                                         continue;
2288                                 }
2289                         } else
2290                                 wait_event(generic_waitq, !(device->stopped));
2291                 }
2292                 if (!cqr->callback)
2293                         cqr->callback = dasd_wakeup_cb;
2294
2295                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2296                 dasd_add_request_tail(cqr);
2297                 if (interruptible) {
2298                         rc = wait_event_interruptible(
2299                                 generic_waitq, _wait_for_wakeup(cqr));
2300                         if (rc == -ERESTARTSYS) {
2301                                 dasd_cancel_req(cqr);
2302                                 /* wait (non-interruptible) for final status */
2303                                 wait_event(generic_waitq,
2304                                            _wait_for_wakeup(cqr));
2305                                 cqr->status = DASD_CQR_FAILED;
2306                                 maincqr->intrc = rc;
2307                                 continue;
2308                         }
2309                 } else
2310                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2311         }
2312
2313         maincqr->endclk = get_tod_clock();
2314         if ((maincqr->status != DASD_CQR_DONE) &&
2315             (maincqr->intrc != -ERESTARTSYS))
2316                 dasd_log_sense(maincqr, &maincqr->irb);
2317         if (maincqr->status == DASD_CQR_DONE)
2318                 rc = 0;
2319         else if (maincqr->intrc)
2320                 rc = maincqr->intrc;
2321         else
2322                 rc = -EIO;
2323         return rc;
2324 }
2325
2326 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2327 {
2328         struct dasd_ccw_req *cqr;
2329
2330         list_for_each_entry(cqr, ccw_queue, blocklist) {
2331                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2332                         return 0;
2333         }
2334
2335         return 1;
2336 }
2337
2338 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2339 {
2340         struct dasd_device *device;
2341         struct dasd_ccw_req *cqr, *n;
2342         u8 *sense = NULL;
2343         int rc;
2344
2345 retry:
2346         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2347                 device = cqr->startdev;
2348                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2349                         continue;
2350
2351                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2352                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2353                         cqr->status = DASD_CQR_FAILED;
2354                         cqr->intrc = -EPERM;
2355                         continue;
2356                 }
2357                 /*Non-temporary stop condition will trigger fail fast*/
2358                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2359                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2360                     !dasd_eer_enabled(device)) {
2361                         cqr->status = DASD_CQR_FAILED;
2362                         cqr->intrc = -EAGAIN;
2363                         continue;
2364                 }
2365
2366                 /*Don't try to start requests if device is stopped*/
2367                 if (interruptible) {
2368                         rc = wait_event_interruptible(
2369                                 generic_waitq, !device->stopped);
2370                         if (rc == -ERESTARTSYS) {
2371                                 cqr->status = DASD_CQR_FAILED;
2372                                 cqr->intrc = rc;
2373                                 continue;
2374                         }
2375                 } else
2376                         wait_event(generic_waitq, !(device->stopped));
2377
2378                 if (!cqr->callback)
2379                         cqr->callback = dasd_wakeup_cb;
2380                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2381                 dasd_add_request_tail(cqr);
2382         }
2383
2384         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2385
2386         rc = 0;
2387         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2388                 /*
2389                  * In some cases the 'File Protected' or 'Incorrect Length'
2390                  * error might be expected and error recovery would be
2391                  * unnecessary in these cases.  Check if the according suppress
2392                  * bit is set.
2393                  */
2394                 sense = dasd_get_sense(&cqr->irb);
2395                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2396                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2397                         continue;
2398                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2399                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2400                         continue;
2401
2402                 /*
2403                  * for alias devices simplify error recovery and
2404                  * return to upper layer
2405                  * do not skip ERP requests
2406                  */
2407                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2408                     (cqr->status == DASD_CQR_TERMINATED ||
2409                      cqr->status == DASD_CQR_NEED_ERP))
2410                         return -EAGAIN;
2411
2412                 /* normal recovery for basedev IO */
2413                 if (__dasd_sleep_on_erp(cqr))
2414                         /* handle erp first */
2415                         goto retry;
2416         }
2417
2418         return 0;
2419 }
2420
2421 /*
2422  * Queue a request to the tail of the device ccw_queue and wait for
2423  * it's completion.
2424  */
2425 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2426 {
2427         return _dasd_sleep_on(cqr, 0);
2428 }
2429 EXPORT_SYMBOL(dasd_sleep_on);
2430
2431 /*
2432  * Start requests from a ccw_queue and wait for their completion.
2433  */
2434 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2435 {
2436         return _dasd_sleep_on_queue(ccw_queue, 0);
2437 }
2438 EXPORT_SYMBOL(dasd_sleep_on_queue);
2439
2440 /*
2441  * Queue a request to the tail of the device ccw_queue and wait
2442  * interruptible for it's completion.
2443  */
2444 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2445 {
2446         return _dasd_sleep_on(cqr, 1);
2447 }
2448 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2449
2450 /*
2451  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2452  * for eckd devices) the currently running request has to be terminated
2453  * and be put back to status queued, before the special request is added
2454  * to the head of the queue. Then the special request is waited on normally.
2455  */
2456 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2457 {
2458         struct dasd_ccw_req *cqr;
2459         int rc;
2460
2461         if (list_empty(&device->ccw_queue))
2462                 return 0;
2463         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2464         rc = device->discipline->term_IO(cqr);
2465         if (!rc)
2466                 /*
2467                  * CQR terminated because a more important request is pending.
2468                  * Undo decreasing of retry counter because this is
2469                  * not an error case.
2470                  */
2471                 cqr->retries++;
2472         return rc;
2473 }
2474
2475 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2476 {
2477         struct dasd_device *device;
2478         int rc;
2479
2480         device = cqr->startdev;
2481         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2482             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2483                 cqr->status = DASD_CQR_FAILED;
2484                 cqr->intrc = -EPERM;
2485                 return -EIO;
2486         }
2487         spin_lock_irq(get_ccwdev_lock(device->cdev));
2488         rc = _dasd_term_running_cqr(device);
2489         if (rc) {
2490                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2491                 return rc;
2492         }
2493         cqr->callback = dasd_wakeup_cb;
2494         cqr->callback_data = DASD_SLEEPON_START_TAG;
2495         cqr->status = DASD_CQR_QUEUED;
2496         /*
2497          * add new request as second
2498          * first the terminated cqr needs to be finished
2499          */
2500         list_add(&cqr->devlist, device->ccw_queue.next);
2501
2502         /* let the bh start the request to keep them in order */
2503         dasd_schedule_device_bh(device);
2504
2505         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2506
2507         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2508
2509         if (cqr->status == DASD_CQR_DONE)
2510                 rc = 0;
2511         else if (cqr->intrc)
2512                 rc = cqr->intrc;
2513         else
2514                 rc = -EIO;
2515
2516         /* kick tasklets */
2517         dasd_schedule_device_bh(device);
2518         if (device->block)
2519                 dasd_schedule_block_bh(device->block);
2520
2521         return rc;
2522 }
2523 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2524
2525 /*
2526  * Cancels a request that was started with dasd_sleep_on_req.
2527  * This is useful to timeout requests. The request will be
2528  * terminated if it is currently in i/o.
2529  * Returns 0 if request termination was successful
2530  *         negative error code if termination failed
2531  * Cancellation of a request is an asynchronous operation! The calling
2532  * function has to wait until the request is properly returned via callback.
2533  */
2534 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2535 {
2536         struct dasd_device *device = cqr->startdev;
2537         unsigned long flags;
2538         int rc;
2539
2540         rc = 0;
2541         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2542         switch (cqr->status) {
2543         case DASD_CQR_QUEUED:
2544                 /* request was not started - just set to cleared */
2545                 cqr->status = DASD_CQR_CLEARED;
2546                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2547                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2548                 break;
2549         case DASD_CQR_IN_IO:
2550                 /* request in IO - terminate IO and release again */
2551                 rc = device->discipline->term_IO(cqr);
2552                 if (rc) {
2553                         dev_err(&device->cdev->dev,
2554                                 "Cancelling request %p failed with rc=%d\n",
2555                                 cqr, rc);
2556                 } else {
2557                         cqr->stopclk = get_tod_clock();
2558                 }
2559                 break;
2560         default: /* already finished or clear pending - do nothing */
2561                 break;
2562         }
2563         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2564         dasd_schedule_device_bh(device);
2565         return rc;
2566 }
2567 EXPORT_SYMBOL(dasd_cancel_req);
2568
2569 /*
2570  * SECTION: Operations of the dasd_block layer.
2571  */
2572
2573 /*
2574  * Timeout function for dasd_block. This is used when the block layer
2575  * is waiting for something that may not come reliably, (e.g. a state
2576  * change interrupt)
2577  */
2578 static void dasd_block_timeout(unsigned long ptr)
2579 {
2580         unsigned long flags;
2581         struct dasd_block *block;
2582
2583         block = (struct dasd_block *) ptr;
2584         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2585         /* re-activate request queue */
2586         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2587         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2588         dasd_schedule_block_bh(block);
2589 }
2590
2591 /*
2592  * Setup timeout for a dasd_block in jiffies.
2593  */
2594 void dasd_block_set_timer(struct dasd_block *block, int expires)
2595 {
2596         if (expires == 0)
2597                 del_timer(&block->timer);
2598         else
2599                 mod_timer(&block->timer, jiffies + expires);
2600 }
2601 EXPORT_SYMBOL(dasd_block_set_timer);
2602
2603 /*
2604  * Clear timeout for a dasd_block.
2605  */
2606 void dasd_block_clear_timer(struct dasd_block *block)
2607 {
2608         del_timer(&block->timer);
2609 }
2610 EXPORT_SYMBOL(dasd_block_clear_timer);
2611
2612 /*
2613  * Process finished error recovery ccw.
2614  */
2615 static void __dasd_process_erp(struct dasd_device *device,
2616                                struct dasd_ccw_req *cqr)
2617 {
2618         dasd_erp_fn_t erp_fn;
2619
2620         if (cqr->status == DASD_CQR_DONE)
2621                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2622         else
2623                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2624         erp_fn = device->discipline->erp_postaction(cqr);
2625         erp_fn(cqr);
2626 }
2627
2628 /*
2629  * Fetch requests from the block device queue.
2630  */
2631 static void __dasd_process_request_queue(struct dasd_block *block)
2632 {
2633         struct request_queue *queue;
2634         struct request *req;
2635         struct dasd_ccw_req *cqr;
2636         struct dasd_device *basedev;
2637         unsigned long flags;
2638         queue = block->request_queue;
2639         basedev = block->base;
2640         /* No queue ? Then there is nothing to do. */
2641         if (queue == NULL)
2642                 return;
2643
2644         /*
2645          * We requeue request from the block device queue to the ccw
2646          * queue only in two states. In state DASD_STATE_READY the
2647          * partition detection is done and we need to requeue requests
2648          * for that. State DASD_STATE_ONLINE is normal block device
2649          * operation.
2650          */
2651         if (basedev->state < DASD_STATE_READY) {
2652                 while ((req = blk_fetch_request(block->request_queue)))
2653                         __blk_end_request_all(req, -EIO);
2654                 return;
2655         }
2656
2657         /*
2658          * if device is stopped do not fetch new requests
2659          * except failfast is active which will let requests fail
2660          * immediately in __dasd_block_start_head()
2661          */
2662         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST))
2663                 return;
2664
2665         /* Now we try to fetch requests from the request queue */
2666         while ((req = blk_peek_request(queue))) {
2667                 if (basedev->features & DASD_FEATURE_READONLY &&
2668                     rq_data_dir(req) == WRITE) {
2669                         DBF_DEV_EVENT(DBF_ERR, basedev,
2670                                       "Rejecting write request %p",
2671                                       req);
2672                         blk_start_request(req);
2673                         __blk_end_request_all(req, -EIO);
2674                         continue;
2675                 }
2676                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2677                     (basedev->features & DASD_FEATURE_FAILFAST ||
2678                      blk_noretry_request(req))) {
2679                         DBF_DEV_EVENT(DBF_ERR, basedev,
2680                                       "Rejecting failfast request %p",
2681                                       req);
2682                         blk_start_request(req);
2683                         __blk_end_request_all(req, -ETIMEDOUT);
2684                         continue;
2685                 }
2686                 cqr = basedev->discipline->build_cp(basedev, block, req);
2687                 if (IS_ERR(cqr)) {
2688                         if (PTR_ERR(cqr) == -EBUSY)
2689                                 break;  /* normal end condition */
2690                         if (PTR_ERR(cqr) == -ENOMEM)
2691                                 break;  /* terminate request queue loop */
2692                         if (PTR_ERR(cqr) == -EAGAIN) {
2693                                 /*
2694                                  * The current request cannot be build right
2695                                  * now, we have to try later. If this request
2696                                  * is the head-of-queue we stop the device
2697                                  * for 1/2 second.
2698                                  */
2699                                 if (!list_empty(&block->ccw_queue))
2700                                         break;
2701                                 spin_lock_irqsave(
2702                                         get_ccwdev_lock(basedev->cdev), flags);
2703                                 dasd_device_set_stop_bits(basedev,
2704                                                           DASD_STOPPED_PENDING);
2705                                 spin_unlock_irqrestore(
2706                                         get_ccwdev_lock(basedev->cdev), flags);
2707                                 dasd_block_set_timer(block, HZ/2);
2708                                 break;
2709                         }
2710                         DBF_DEV_EVENT(DBF_ERR, basedev,
2711                                       "CCW creation failed (rc=%ld) "
2712                                       "on request %p",
2713                                       PTR_ERR(cqr), req);
2714                         blk_start_request(req);
2715                         __blk_end_request_all(req, -EIO);
2716                         continue;
2717                 }
2718                 /*
2719                  *  Note: callback is set to dasd_return_cqr_cb in
2720                  * __dasd_block_start_head to cover erp requests as well
2721                  */
2722                 cqr->callback_data = (void *) req;
2723                 cqr->status = DASD_CQR_FILLED;
2724                 req->completion_data = cqr;
2725                 blk_start_request(req);
2726                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2727                 INIT_LIST_HEAD(&cqr->devlist);
2728                 dasd_profile_start(block, cqr, req);
2729         }
2730 }
2731
2732 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2733 {
2734         struct request *req;
2735         int status;
2736         int error = 0;
2737
2738         req = (struct request *) cqr->callback_data;
2739         dasd_profile_end(cqr->block, cqr, req);
2740         status = cqr->block->base->discipline->free_cp(cqr, req);
2741         if (status < 0)
2742                 error = status;
2743         else if (status == 0) {
2744                 if (cqr->intrc == -EPERM)
2745                         error = -EBADE;
2746                 else if (cqr->intrc == -ENOLINK ||
2747                          cqr->intrc == -ETIMEDOUT)
2748                         error = cqr->intrc;
2749                 else
2750                         error = -EIO;
2751         }
2752         __blk_end_request_all(req, error);
2753 }
2754
2755 /*
2756  * Process ccw request queue.
2757  */
2758 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2759                                            struct list_head *final_queue)
2760 {
2761         struct list_head *l, *n;
2762         struct dasd_ccw_req *cqr;
2763         dasd_erp_fn_t erp_fn;
2764         unsigned long flags;
2765         struct dasd_device *base = block->base;
2766
2767 restart:
2768         /* Process request with final status. */
2769         list_for_each_safe(l, n, &block->ccw_queue) {
2770                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2771                 if (cqr->status != DASD_CQR_DONE &&
2772                     cqr->status != DASD_CQR_FAILED &&
2773                     cqr->status != DASD_CQR_NEED_ERP &&
2774                     cqr->status != DASD_CQR_TERMINATED)
2775                         continue;
2776
2777                 if (cqr->status == DASD_CQR_TERMINATED) {
2778                         base->discipline->handle_terminated_request(cqr);
2779                         goto restart;
2780                 }
2781
2782                 /*  Process requests that may be recovered */
2783                 if (cqr->status == DASD_CQR_NEED_ERP) {
2784                         erp_fn = base->discipline->erp_action(cqr);
2785                         if (IS_ERR(erp_fn(cqr)))
2786                                 continue;
2787                         goto restart;
2788                 }
2789
2790                 /* log sense for fatal error */
2791                 if (cqr->status == DASD_CQR_FAILED) {
2792                         dasd_log_sense(cqr, &cqr->irb);
2793                 }
2794
2795                 /* First of all call extended error reporting. */
2796                 if (dasd_eer_enabled(base) &&
2797                     cqr->status == DASD_CQR_FAILED) {
2798                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2799
2800                         /* restart request  */
2801                         cqr->status = DASD_CQR_FILLED;
2802                         cqr->retries = 255;
2803                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2804                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2805                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2806                                                flags);
2807                         goto restart;
2808                 }
2809
2810                 /* Process finished ERP request. */
2811                 if (cqr->refers) {
2812                         __dasd_process_erp(base, cqr);
2813                         goto restart;
2814                 }
2815
2816                 /* Rechain finished requests to final queue */
2817                 cqr->endclk = get_tod_clock();
2818                 list_move_tail(&cqr->blocklist, final_queue);
2819         }
2820 }
2821
2822 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2823 {
2824         dasd_schedule_block_bh(cqr->block);
2825 }
2826
2827 static void __dasd_block_start_head(struct dasd_block *block)
2828 {
2829         struct dasd_ccw_req *cqr;
2830
2831         if (list_empty(&block->ccw_queue))
2832                 return;
2833         /* We allways begin with the first requests on the queue, as some
2834          * of previously started requests have to be enqueued on a
2835          * dasd_device again for error recovery.
2836          */
2837         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2838                 if (cqr->status != DASD_CQR_FILLED)
2839                         continue;
2840                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2841                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2842                         cqr->status = DASD_CQR_FAILED;
2843                         cqr->intrc = -EPERM;
2844                         dasd_schedule_block_bh(block);
2845                         continue;
2846                 }
2847                 /* Non-temporary stop condition will trigger fail fast */
2848                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2849                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2850                     (!dasd_eer_enabled(block->base))) {
2851                         cqr->status = DASD_CQR_FAILED;
2852                         cqr->intrc = -ENOLINK;
2853                         dasd_schedule_block_bh(block);
2854                         continue;
2855                 }
2856                 /* Don't try to start requests if device is stopped */
2857                 if (block->base->stopped)
2858                         return;
2859
2860                 /* just a fail safe check, should not happen */
2861                 if (!cqr->startdev)
2862                         cqr->startdev = block->base;
2863
2864                 /* make sure that the requests we submit find their way back */
2865                 cqr->callback = dasd_return_cqr_cb;
2866
2867                 dasd_add_request_tail(cqr);
2868         }
2869 }
2870
2871 /*
2872  * Central dasd_block layer routine. Takes requests from the generic
2873  * block layer request queue, creates ccw requests, enqueues them on
2874  * a dasd_device and processes ccw requests that have been returned.
2875  */
2876 static void dasd_block_tasklet(struct dasd_block *block)
2877 {
2878         struct list_head final_queue;
2879         struct list_head *l, *n;
2880         struct dasd_ccw_req *cqr;
2881
2882         atomic_set(&block->tasklet_scheduled, 0);
2883         INIT_LIST_HEAD(&final_queue);
2884         spin_lock(&block->queue_lock);
2885         /* Finish off requests on ccw queue */
2886         __dasd_process_block_ccw_queue(block, &final_queue);
2887         spin_unlock(&block->queue_lock);
2888         /* Now call the callback function of requests with final status */
2889         spin_lock_irq(&block->request_queue_lock);
2890         list_for_each_safe(l, n, &final_queue) {
2891                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2892                 list_del_init(&cqr->blocklist);
2893                 __dasd_cleanup_cqr(cqr);
2894         }
2895         spin_lock(&block->queue_lock);
2896         /* Get new request from the block device request queue */
2897         __dasd_process_request_queue(block);
2898         /* Now check if the head of the ccw queue needs to be started. */
2899         __dasd_block_start_head(block);
2900         spin_unlock(&block->queue_lock);
2901         spin_unlock_irq(&block->request_queue_lock);
2902         if (waitqueue_active(&shutdown_waitq))
2903                 wake_up(&shutdown_waitq);
2904         dasd_put_device(block->base);
2905 }
2906
2907 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2908 {
2909         wake_up(&dasd_flush_wq);
2910 }
2911
2912 /*
2913  * Requeue a request back to the block request queue
2914  * only works for block requests
2915  */
2916 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2917 {
2918         struct dasd_block *block = cqr->block;
2919         struct request *req;
2920         unsigned long flags;
2921
2922         if (!block)
2923                 return -EINVAL;
2924         spin_lock_irqsave(&block->queue_lock, flags);
2925         req = (struct request *) cqr->callback_data;
2926         blk_requeue_request(block->request_queue, req);
2927         spin_unlock_irqrestore(&block->queue_lock, flags);
2928
2929         return 0;
2930 }
2931
2932 /*
2933  * Go through all request on the dasd_block request queue, cancel them
2934  * on the respective dasd_device, and return them to the generic
2935  * block layer.
2936  */
2937 static int dasd_flush_block_queue(struct dasd_block *block)
2938 {
2939         struct dasd_ccw_req *cqr, *n;
2940         int rc, i;
2941         struct list_head flush_queue;
2942
2943         INIT_LIST_HEAD(&flush_queue);
2944         spin_lock_bh(&block->queue_lock);
2945         rc = 0;
2946 restart:
2947         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2948                 /* if this request currently owned by a dasd_device cancel it */
2949                 if (cqr->status >= DASD_CQR_QUEUED)
2950                         rc = dasd_cancel_req(cqr);
2951                 if (rc < 0)
2952                         break;
2953                 /* Rechain request (including erp chain) so it won't be
2954                  * touched by the dasd_block_tasklet anymore.
2955                  * Replace the callback so we notice when the request
2956                  * is returned from the dasd_device layer.
2957                  */
2958                 cqr->callback = _dasd_wake_block_flush_cb;
2959                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2960                         list_move_tail(&cqr->blocklist, &flush_queue);
2961                 if (i > 1)
2962                         /* moved more than one request - need to restart */
2963                         goto restart;
2964         }
2965         spin_unlock_bh(&block->queue_lock);
2966         /* Now call the callback function of flushed requests */
2967 restart_cb:
2968         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2969                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2970                 /* Process finished ERP request. */
2971                 if (cqr->refers) {
2972                         spin_lock_bh(&block->queue_lock);
2973                         __dasd_process_erp(block->base, cqr);
2974                         spin_unlock_bh(&block->queue_lock);
2975                         /* restart list_for_xx loop since dasd_process_erp
2976                          * might remove multiple elements */
2977                         goto restart_cb;
2978                 }
2979                 /* call the callback function */
2980                 spin_lock_irq(&block->request_queue_lock);
2981                 cqr->endclk = get_tod_clock();
2982                 list_del_init(&cqr->blocklist);
2983                 __dasd_cleanup_cqr(cqr);
2984                 spin_unlock_irq(&block->request_queue_lock);
2985         }
2986         return rc;
2987 }
2988
2989 /*
2990  * Schedules a call to dasd_tasklet over the device tasklet.
2991  */
2992 void dasd_schedule_block_bh(struct dasd_block *block)
2993 {
2994         /* Protect against rescheduling. */
2995         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2996                 return;
2997         /* life cycle of block is bound to it's base device */
2998         dasd_get_device(block->base);
2999         tasklet_hi_schedule(&block->tasklet);
3000 }
3001 EXPORT_SYMBOL(dasd_schedule_block_bh);
3002
3003
3004 /*
3005  * SECTION: external block device operations
3006  * (request queue handling, open, release, etc.)
3007  */
3008
3009 /*
3010  * Dasd request queue function. Called from ll_rw_blk.c
3011  */
3012 static void do_dasd_request(struct request_queue *queue)
3013 {
3014         struct dasd_block *block;
3015
3016         block = queue->queuedata;
3017         spin_lock(&block->queue_lock);
3018         /* Get new request from the block device request queue */
3019         __dasd_process_request_queue(block);
3020         /* Now check if the head of the ccw queue needs to be started. */
3021         __dasd_block_start_head(block);
3022         spin_unlock(&block->queue_lock);
3023 }
3024
3025 /*
3026  * Block timeout callback, called from the block layer
3027  *
3028  * request_queue lock is held on entry.
3029  *
3030  * Return values:
3031  * BLK_EH_RESET_TIMER if the request should be left running
3032  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3033  *                    by the driver.
3034  */
3035 enum blk_eh_timer_return dasd_times_out(struct request *req)
3036 {
3037         struct dasd_ccw_req *cqr = req->completion_data;
3038         struct dasd_block *block = req->q->queuedata;
3039         struct dasd_device *device;
3040         int rc = 0;
3041
3042         if (!cqr)
3043                 return BLK_EH_NOT_HANDLED;
3044
3045         device = cqr->startdev ? cqr->startdev : block->base;
3046         if (!device->blk_timeout)
3047                 return BLK_EH_RESET_TIMER;
3048         DBF_DEV_EVENT(DBF_WARNING, device,
3049                       " dasd_times_out cqr %p status %x",
3050                       cqr, cqr->status);
3051
3052         spin_lock(&block->queue_lock);
3053         spin_lock(get_ccwdev_lock(device->cdev));
3054         cqr->retries = -1;
3055         cqr->intrc = -ETIMEDOUT;
3056         if (cqr->status >= DASD_CQR_QUEUED) {
3057                 spin_unlock(get_ccwdev_lock(device->cdev));
3058                 rc = dasd_cancel_req(cqr);
3059         } else if (cqr->status == DASD_CQR_FILLED ||
3060                    cqr->status == DASD_CQR_NEED_ERP) {
3061                 cqr->status = DASD_CQR_TERMINATED;
3062                 spin_unlock(get_ccwdev_lock(device->cdev));
3063         } else if (cqr->status == DASD_CQR_IN_ERP) {
3064                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3065
3066                 list_for_each_entry_safe(searchcqr, nextcqr,
3067                                          &block->ccw_queue, blocklist) {
3068                         tmpcqr = searchcqr;
3069                         while (tmpcqr->refers)
3070                                 tmpcqr = tmpcqr->refers;
3071                         if (tmpcqr != cqr)
3072                                 continue;
3073                         /* searchcqr is an ERP request for cqr */
3074                         searchcqr->retries = -1;
3075                         searchcqr->intrc = -ETIMEDOUT;
3076                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3077                                 spin_unlock(get_ccwdev_lock(device->cdev));
3078                                 rc = dasd_cancel_req(searchcqr);
3079                                 spin_lock(get_ccwdev_lock(device->cdev));
3080                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3081                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3082                                 searchcqr->status = DASD_CQR_TERMINATED;
3083                                 rc = 0;
3084                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3085                                 /*
3086                                  * Shouldn't happen; most recent ERP
3087                                  * request is at the front of queue
3088                                  */
3089                                 continue;
3090                         }
3091                         break;
3092                 }
3093                 spin_unlock(get_ccwdev_lock(device->cdev));
3094         }
3095         dasd_schedule_block_bh(block);
3096         spin_unlock(&block->queue_lock);
3097
3098         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3099 }
3100
3101 /*
3102  * Allocate and initialize request queue and default I/O scheduler.
3103  */
3104 static int dasd_alloc_queue(struct dasd_block *block)
3105 {
3106         block->request_queue = blk_init_queue(do_dasd_request,
3107                                                &block->request_queue_lock);
3108         if (block->request_queue == NULL)
3109                 return -ENOMEM;
3110
3111         block->request_queue->queuedata = block;
3112
3113         return 0;
3114 }
3115
3116 /*
3117  * Allocate and initialize request queue.
3118  */
3119 static void dasd_setup_queue(struct dasd_block *block)
3120 {
3121         int max;
3122
3123         if (block->base->features & DASD_FEATURE_USERAW) {
3124                 /*
3125                  * the max_blocks value for raw_track access is 256
3126                  * it is higher than the native ECKD value because we
3127                  * only need one ccw per track
3128                  * so the max_hw_sectors are
3129                  * 2048 x 512B = 1024kB = 16 tracks
3130                  */
3131                 max = 2048;
3132         } else {
3133                 max = block->base->discipline->max_blocks << block->s2b_shift;
3134         }
3135         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue);
3136         block->request_queue->limits.max_dev_sectors = max;
3137         blk_queue_logical_block_size(block->request_queue,
3138                                      block->bp_block);
3139         blk_queue_max_hw_sectors(block->request_queue, max);
3140         blk_queue_max_segments(block->request_queue, -1L);
3141         /* with page sized segments we can translate each segement into
3142          * one idaw/tidaw
3143          */
3144         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3145         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3146 }
3147
3148 /*
3149  * Deactivate and free request queue.
3150  */
3151 static void dasd_free_queue(struct dasd_block *block)
3152 {
3153         if (block->request_queue) {
3154                 blk_cleanup_queue(block->request_queue);
3155                 block->request_queue = NULL;
3156         }
3157 }
3158
3159 /*
3160  * Flush request on the request queue.
3161  */
3162 static void dasd_flush_request_queue(struct dasd_block *block)
3163 {
3164         struct request *req;
3165
3166         if (!block->request_queue)
3167                 return;
3168
3169         spin_lock_irq(&block->request_queue_lock);
3170         while ((req = blk_fetch_request(block->request_queue)))
3171                 __blk_end_request_all(req, -EIO);
3172         spin_unlock_irq(&block->request_queue_lock);
3173 }
3174
3175 static int dasd_open(struct block_device *bdev, fmode_t mode)
3176 {
3177         struct dasd_device *base;
3178         int rc;
3179
3180         base = dasd_device_from_gendisk(bdev->bd_disk);
3181         if (!base)
3182                 return -ENODEV;
3183
3184         atomic_inc(&base->block->open_count);
3185         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3186                 rc = -ENODEV;
3187                 goto unlock;
3188         }
3189
3190         if (!try_module_get(base->discipline->owner)) {
3191                 rc = -EINVAL;
3192                 goto unlock;
3193         }
3194
3195         if (dasd_probeonly) {
3196                 dev_info(&base->cdev->dev,
3197                          "Accessing the DASD failed because it is in "
3198                          "probeonly mode\n");
3199                 rc = -EPERM;
3200                 goto out;
3201         }
3202
3203         if (base->state <= DASD_STATE_BASIC) {
3204                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3205                               " Cannot open unrecognized device");
3206                 rc = -ENODEV;
3207                 goto out;
3208         }
3209
3210         if ((mode & FMODE_WRITE) &&
3211             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3212              (base->features & DASD_FEATURE_READONLY))) {
3213                 rc = -EROFS;
3214                 goto out;
3215         }
3216
3217         dasd_put_device(base);
3218         return 0;
3219
3220 out:
3221         module_put(base->discipline->owner);
3222 unlock:
3223         atomic_dec(&base->block->open_count);
3224         dasd_put_device(base);
3225         return rc;
3226 }
3227
3228 static void dasd_release(struct gendisk *disk, fmode_t mode)
3229 {
3230         struct dasd_device *base = dasd_device_from_gendisk(disk);
3231         if (base) {
3232                 atomic_dec(&base->block->open_count);
3233                 module_put(base->discipline->owner);
3234                 dasd_put_device(base);
3235         }
3236 }
3237
3238 /*
3239  * Return disk geometry.
3240  */
3241 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3242 {
3243         struct dasd_device *base;
3244
3245         base = dasd_device_from_gendisk(bdev->bd_disk);
3246         if (!base)
3247                 return -ENODEV;
3248
3249         if (!base->discipline ||
3250             !base->discipline->fill_geometry) {
3251                 dasd_put_device(base);
3252                 return -EINVAL;
3253         }
3254         base->discipline->fill_geometry(base->block, geo);
3255         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3256         dasd_put_device(base);
3257         return 0;
3258 }
3259
3260 const struct block_device_operations
3261 dasd_device_operations = {
3262         .owner          = THIS_MODULE,
3263         .open           = dasd_open,
3264         .release        = dasd_release,
3265         .ioctl          = dasd_ioctl,
3266         .compat_ioctl   = dasd_ioctl,
3267         .getgeo         = dasd_getgeo,
3268 };
3269
3270 /*******************************************************************************
3271  * end of block device operations
3272  */
3273
3274 static void
3275 dasd_exit(void)
3276 {
3277 #ifdef CONFIG_PROC_FS
3278         dasd_proc_exit();
3279 #endif
3280         dasd_eer_exit();
3281         if (dasd_page_cache != NULL) {
3282                 kmem_cache_destroy(dasd_page_cache);
3283                 dasd_page_cache = NULL;
3284         }
3285         dasd_gendisk_exit();
3286         dasd_devmap_exit();
3287         if (dasd_debug_area != NULL) {
3288                 debug_unregister(dasd_debug_area);
3289                 dasd_debug_area = NULL;
3290         }
3291         dasd_statistics_removeroot();
3292 }
3293
3294 /*
3295  * SECTION: common functions for ccw_driver use
3296  */
3297
3298 /*
3299  * Is the device read-only?
3300  * Note that this function does not report the setting of the
3301  * readonly device attribute, but how it is configured in z/VM.
3302  */
3303 int dasd_device_is_ro(struct dasd_device *device)
3304 {
3305         struct ccw_dev_id dev_id;
3306         struct diag210 diag_data;
3307         int rc;
3308
3309         if (!MACHINE_IS_VM)
3310                 return 0;
3311         ccw_device_get_id(device->cdev, &dev_id);
3312         memset(&diag_data, 0, sizeof(diag_data));
3313         diag_data.vrdcdvno = dev_id.devno;
3314         diag_data.vrdclen = sizeof(diag_data);
3315         rc = diag210(&diag_data);
3316         if (rc == 0 || rc == 2) {
3317                 return diag_data.vrdcvfla & 0x80;
3318         } else {
3319                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3320                           dev_id.devno, rc);
3321                 return 0;
3322         }
3323 }
3324 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3325
3326 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3327 {
3328         struct ccw_device *cdev = data;
3329         int ret;
3330
3331         ret = ccw_device_set_online(cdev);
3332         if (ret)
3333                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3334                         dev_name(&cdev->dev), ret);
3335 }
3336
3337 /*
3338  * Initial attempt at a probe function. this can be simplified once
3339  * the other detection code is gone.
3340  */
3341 int dasd_generic_probe(struct ccw_device *cdev,
3342                        struct dasd_discipline *discipline)
3343 {
3344         int ret;
3345
3346         ret = dasd_add_sysfs_files(cdev);
3347         if (ret) {
3348                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3349                                 "dasd_generic_probe: could not add "
3350                                 "sysfs entries");
3351                 return ret;
3352         }
3353         cdev->handler = &dasd_int_handler;
3354
3355         /*
3356          * Automatically online either all dasd devices (dasd_autodetect)
3357          * or all devices specified with dasd= parameters during
3358          * initial probe.
3359          */
3360         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3361             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3362                 async_schedule(dasd_generic_auto_online, cdev);
3363         return 0;
3364 }
3365 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3366
3367 /*
3368  * This will one day be called from a global not_oper handler.
3369  * It is also used by driver_unregister during module unload.
3370  */
3371 void dasd_generic_remove(struct ccw_device *cdev)
3372 {
3373         struct dasd_device *device;
3374         struct dasd_block *block;
3375
3376         cdev->handler = NULL;
3377
3378         device = dasd_device_from_cdev(cdev);
3379         if (IS_ERR(device)) {
3380                 dasd_remove_sysfs_files(cdev);
3381                 return;
3382         }
3383         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3384             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3385                 /* Already doing offline processing */
3386                 dasd_put_device(device);
3387                 dasd_remove_sysfs_files(cdev);
3388                 return;
3389         }
3390         /*
3391          * This device is removed unconditionally. Set offline
3392          * flag to prevent dasd_open from opening it while it is
3393          * no quite down yet.
3394          */
3395         dasd_set_target_state(device, DASD_STATE_NEW);
3396         /* dasd_delete_device destroys the device reference. */
3397         block = device->block;
3398         dasd_delete_device(device);
3399         /*
3400          * life cycle of block is bound to device, so delete it after
3401          * device was safely removed
3402          */
3403         if (block)
3404                 dasd_free_block(block);
3405
3406         dasd_remove_sysfs_files(cdev);
3407 }
3408 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3409
3410 /*
3411  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3412  * the device is detected for the first time and is supposed to be used
3413  * or the user has started activation through sysfs.
3414  */
3415 int dasd_generic_set_online(struct ccw_device *cdev,
3416                             struct dasd_discipline *base_discipline)
3417 {
3418         struct dasd_discipline *discipline;
3419         struct dasd_device *device;
3420         int rc;
3421
3422         /* first online clears initial online feature flag */
3423         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3424         device = dasd_create_device(cdev);
3425         if (IS_ERR(device))
3426                 return PTR_ERR(device);
3427
3428         discipline = base_discipline;
3429         if (device->features & DASD_FEATURE_USEDIAG) {
3430                 if (!dasd_diag_discipline_pointer) {
3431                         /* Try to load the required module. */
3432                         rc = request_module(DASD_DIAG_MOD);
3433                         if (rc) {
3434                                 pr_warn("%s Setting the DASD online failed "
3435                                         "because the required module %s "
3436                                         "could not be loaded (rc=%d)\n",
3437                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3438                                         rc);
3439                                 dasd_delete_device(device);
3440                                 return -ENODEV;
3441                         }
3442                 }
3443                 /* Module init could have failed, so check again here after
3444                  * request_module(). */
3445                 if (!dasd_diag_discipline_pointer) {
3446                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3447                                 dev_name(&cdev->dev));
3448                         dasd_delete_device(device);
3449                         return -ENODEV;
3450                 }
3451                 discipline = dasd_diag_discipline_pointer;
3452         }
3453         if (!try_module_get(base_discipline->owner)) {
3454                 dasd_delete_device(device);
3455                 return -EINVAL;
3456         }
3457         if (!try_module_get(discipline->owner)) {
3458                 module_put(base_discipline->owner);
3459                 dasd_delete_device(device);
3460                 return -EINVAL;
3461         }
3462         device->base_discipline = base_discipline;
3463         device->discipline = discipline;
3464
3465         /* check_device will allocate block device if necessary */
3466         rc = discipline->check_device(device);
3467         if (rc) {
3468                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3469                         dev_name(&cdev->dev), discipline->name, rc);
3470                 module_put(discipline->owner);
3471                 module_put(base_discipline->owner);
3472                 dasd_delete_device(device);
3473                 return rc;
3474         }
3475
3476         dasd_set_target_state(device, DASD_STATE_ONLINE);
3477         if (device->state <= DASD_STATE_KNOWN) {
3478                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3479                         dev_name(&cdev->dev));
3480                 rc = -ENODEV;
3481                 dasd_set_target_state(device, DASD_STATE_NEW);
3482                 if (device->block)
3483                         dasd_free_block(device->block);
3484                 dasd_delete_device(device);
3485         } else
3486                 pr_debug("dasd_generic device %s found\n",
3487                                 dev_name(&cdev->dev));
3488
3489         wait_event(dasd_init_waitq, _wait_for_device(device));
3490
3491         dasd_put_device(device);
3492         return rc;
3493 }
3494 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3495
3496 int dasd_generic_set_offline(struct ccw_device *cdev)
3497 {
3498         struct dasd_device *device;
3499         struct dasd_block *block;
3500         int max_count, open_count, rc;
3501
3502         rc = 0;
3503         device = dasd_device_from_cdev(cdev);
3504         if (IS_ERR(device))
3505                 return PTR_ERR(device);
3506
3507         /*
3508          * We must make sure that this device is currently not in use.
3509          * The open_count is increased for every opener, that includes
3510          * the blkdev_get in dasd_scan_partitions. We are only interested
3511          * in the other openers.
3512          */
3513         if (device->block) {
3514                 max_count = device->block->bdev ? 0 : -1;
3515                 open_count = atomic_read(&device->block->open_count);
3516                 if (open_count > max_count) {
3517                         if (open_count > 0)
3518                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3519                                         dev_name(&cdev->dev), open_count);
3520                         else
3521                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3522                                         dev_name(&cdev->dev));
3523                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3524                         dasd_put_device(device);
3525                         return -EBUSY;
3526                 }
3527         }
3528
3529         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3530                 /*
3531                  * safe offline already running
3532                  * could only be called by normal offline so safe_offline flag
3533                  * needs to be removed to run normal offline and kill all I/O
3534                  */
3535                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3536                         /* Already doing normal offline processing */
3537                         dasd_put_device(device);
3538                         return -EBUSY;
3539                 } else
3540                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3541
3542         } else
3543                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3544                         /* Already doing offline processing */
3545                         dasd_put_device(device);
3546                         return -EBUSY;
3547                 }
3548
3549         /*
3550          * if safe_offline called set safe_offline_running flag and
3551          * clear safe_offline so that a call to normal offline
3552          * can overrun safe_offline processing
3553          */
3554         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3555             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3556                 /*
3557                  * If we want to set the device safe offline all IO operations
3558                  * should be finished before continuing the offline process
3559                  * so sync bdev first and then wait for our queues to become
3560                  * empty
3561                  */
3562                 /* sync blockdev and partitions */
3563                 rc = fsync_bdev(device->block->bdev);
3564                 if (rc != 0)
3565                         goto interrupted;
3566
3567                 /* schedule device tasklet and wait for completion */
3568                 dasd_schedule_device_bh(device);
3569                 rc = wait_event_interruptible(shutdown_waitq,
3570                                               _wait_for_empty_queues(device));
3571                 if (rc != 0)
3572                         goto interrupted;
3573         }
3574
3575         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3576         dasd_set_target_state(device, DASD_STATE_NEW);
3577         /* dasd_delete_device destroys the device reference. */
3578         block = device->block;
3579         dasd_delete_device(device);
3580         /*
3581          * life cycle of block is bound to device, so delete it after
3582          * device was safely removed
3583          */
3584         if (block)
3585                 dasd_free_block(block);
3586         return 0;
3587
3588 interrupted:
3589         /* interrupted by signal */
3590         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3591         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3592         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3593         dasd_put_device(device);
3594         return rc;
3595 }
3596 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3597
3598 int dasd_generic_last_path_gone(struct dasd_device *device)
3599 {
3600         struct dasd_ccw_req *cqr;
3601
3602         dev_warn(&device->cdev->dev, "No operational channel path is left "
3603                  "for the device\n");
3604         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3605         /* First of all call extended error reporting. */
3606         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3607
3608         if (device->state < DASD_STATE_BASIC)
3609                 return 0;
3610         /* Device is active. We want to keep it. */
3611         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3612                 if ((cqr->status == DASD_CQR_IN_IO) ||
3613                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3614                         cqr->status = DASD_CQR_QUEUED;
3615                         cqr->retries++;
3616                 }
3617         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3618         dasd_device_clear_timer(device);
3619         dasd_schedule_device_bh(device);
3620         return 1;
3621 }
3622 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3623
3624 int dasd_generic_path_operational(struct dasd_device *device)
3625 {
3626         dev_info(&device->cdev->dev, "A channel path to the device has become "
3627                  "operational\n");
3628         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3629         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3630         if (device->stopped & DASD_UNRESUMED_PM) {
3631                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3632                 dasd_restore_device(device);
3633                 return 1;
3634         }
3635         dasd_schedule_device_bh(device);
3636         if (device->block)
3637                 dasd_schedule_block_bh(device->block);
3638
3639         if (!device->stopped)
3640                 wake_up(&generic_waitq);
3641
3642         return 1;
3643 }
3644 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3645
3646 int dasd_generic_notify(struct ccw_device *cdev, int event)
3647 {
3648         struct dasd_device *device;
3649         int ret;
3650
3651         device = dasd_device_from_cdev_locked(cdev);
3652         if (IS_ERR(device))
3653                 return 0;
3654         ret = 0;
3655         switch (event) {
3656         case CIO_GONE:
3657         case CIO_BOXED:
3658         case CIO_NO_PATH:
3659                 device->path_data.opm = 0;
3660                 device->path_data.ppm = 0;
3661                 device->path_data.npm = 0;
3662                 ret = dasd_generic_last_path_gone(device);
3663                 break;
3664         case CIO_OPER:
3665                 ret = 1;
3666                 if (device->path_data.opm)
3667                         ret = dasd_generic_path_operational(device);
3668                 break;
3669         }
3670         dasd_put_device(device);
3671         return ret;
3672 }
3673 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3674
3675 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3676 {
3677         int chp;
3678         __u8 oldopm, eventlpm;
3679         struct dasd_device *device;
3680
3681         device = dasd_device_from_cdev_locked(cdev);
3682         if (IS_ERR(device))
3683                 return;
3684         for (chp = 0; chp < 8; chp++) {
3685                 eventlpm = 0x80 >> chp;
3686                 if (path_event[chp] & PE_PATH_GONE) {
3687                         oldopm = device->path_data.opm;
3688                         device->path_data.opm &= ~eventlpm;
3689                         device->path_data.ppm &= ~eventlpm;
3690                         device->path_data.npm &= ~eventlpm;
3691                         if (oldopm && !device->path_data.opm) {
3692                                 dev_warn(&device->cdev->dev,
3693                                          "No verified channel paths remain "
3694                                          "for the device\n");
3695                                 DBF_DEV_EVENT(DBF_WARNING, device,
3696                                               "%s", "last verified path gone");
3697                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3698                                 dasd_device_set_stop_bits(device,
3699                                                           DASD_STOPPED_DC_WAIT);
3700                         }
3701                 }
3702                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3703                         device->path_data.opm &= ~eventlpm;
3704                         device->path_data.ppm &= ~eventlpm;
3705                         device->path_data.npm &= ~eventlpm;
3706                         device->path_data.tbvpm |= eventlpm;
3707                         dasd_schedule_device_bh(device);
3708                 }
3709                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3710                         if (!(device->path_data.opm & eventlpm) &&
3711                             !(device->path_data.tbvpm & eventlpm)) {
3712                                 /*
3713                                  * we can not establish a pathgroup on an
3714                                  * unavailable path, so trigger a path
3715                                  * verification first
3716                                  */
3717                                 device->path_data.tbvpm |= eventlpm;
3718                                 dasd_schedule_device_bh(device);
3719                         }
3720                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3721                                       "Pathgroup re-established\n");
3722                         if (device->discipline->kick_validate)
3723                                 device->discipline->kick_validate(device);
3724                 }
3725         }
3726         dasd_put_device(device);
3727 }
3728 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3729
3730 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3731 {
3732         if (!device->path_data.opm && lpm) {
3733                 device->path_data.opm = lpm;
3734                 dasd_generic_path_operational(device);
3735         } else
3736                 device->path_data.opm |= lpm;
3737         return 0;
3738 }
3739 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3740
3741
3742 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3743 {
3744         struct dasd_device *device = dasd_device_from_cdev(cdev);
3745         struct list_head freeze_queue;
3746         struct dasd_ccw_req *cqr, *n;
3747         struct dasd_ccw_req *refers;
3748         int rc;
3749
3750         if (IS_ERR(device))
3751                 return PTR_ERR(device);
3752
3753         /* mark device as suspended */
3754         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3755
3756         if (device->discipline->freeze)
3757                 rc = device->discipline->freeze(device);
3758
3759         /* disallow new I/O  */
3760         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3761
3762         /* clear active requests and requeue them to block layer if possible */
3763         INIT_LIST_HEAD(&freeze_queue);
3764         spin_lock_irq(get_ccwdev_lock(cdev));
3765         rc = 0;
3766         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3767                 /* Check status and move request to flush_queue */
3768                 if (cqr->status == DASD_CQR_IN_IO) {
3769                         rc = device->discipline->term_IO(cqr);
3770                         if (rc) {
3771                                 /* unable to terminate requeust */
3772                                 dev_err(&device->cdev->dev,
3773                                         "Unable to terminate request %p "
3774                                         "on suspend\n", cqr);
3775                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3776                                 dasd_put_device(device);
3777                                 return rc;
3778                         }
3779                 }
3780                 list_move_tail(&cqr->devlist, &freeze_queue);
3781         }
3782         spin_unlock_irq(get_ccwdev_lock(cdev));
3783
3784         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3785                 wait_event(dasd_flush_wq,
3786                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3787                 if (cqr->status == DASD_CQR_CLEARED)
3788                         cqr->status = DASD_CQR_QUEUED;
3789
3790                 /* requeue requests to blocklayer will only work for
3791                    block device requests */
3792                 if (_dasd_requeue_request(cqr))
3793                         continue;
3794
3795                 /* remove requests from device and block queue */
3796                 list_del_init(&cqr->devlist);
3797                 while (cqr->refers != NULL) {
3798                         refers = cqr->refers;
3799                         /* remove the request from the block queue */
3800                         list_del(&cqr->blocklist);
3801                         /* free the finished erp request */
3802                         dasd_free_erp_request(cqr, cqr->memdev);
3803                         cqr = refers;
3804                 }
3805                 if (cqr->block)
3806                         list_del_init(&cqr->blocklist);
3807                 cqr->block->base->discipline->free_cp(
3808                         cqr, (struct request *) cqr->callback_data);
3809         }
3810
3811         /*
3812          * if requests remain then they are internal request
3813          * and go back to the device queue
3814          */
3815         if (!list_empty(&freeze_queue)) {
3816                 /* move freeze_queue to start of the ccw_queue */
3817                 spin_lock_irq(get_ccwdev_lock(cdev));
3818                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3819                 spin_unlock_irq(get_ccwdev_lock(cdev));
3820         }
3821         dasd_put_device(device);
3822         return rc;
3823 }
3824 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3825
3826 int dasd_generic_restore_device(struct ccw_device *cdev)
3827 {
3828         struct dasd_device *device = dasd_device_from_cdev(cdev);
3829         int rc = 0;
3830
3831         if (IS_ERR(device))
3832                 return PTR_ERR(device);
3833
3834         /* allow new IO again */
3835         dasd_device_remove_stop_bits(device,
3836                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3837
3838         dasd_schedule_device_bh(device);
3839
3840         /*
3841          * call discipline restore function
3842          * if device is stopped do nothing e.g. for disconnected devices
3843          */
3844         if (device->discipline->restore && !(device->stopped))
3845                 rc = device->discipline->restore(device);
3846         if (rc || device->stopped)
3847                 /*
3848                  * if the resume failed for the DASD we put it in
3849                  * an UNRESUMED stop state
3850                  */
3851                 device->stopped |= DASD_UNRESUMED_PM;
3852
3853         if (device->block)
3854                 dasd_schedule_block_bh(device->block);
3855
3856         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3857         dasd_put_device(device);
3858         return 0;
3859 }
3860 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3861
3862 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3863                                                    void *rdc_buffer,
3864                                                    int rdc_buffer_size,
3865                                                    int magic)
3866 {
3867         struct dasd_ccw_req *cqr;
3868         struct ccw1 *ccw;
3869         unsigned long *idaw;
3870
3871         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3872
3873         if (IS_ERR(cqr)) {
3874                 /* internal error 13 - Allocating the RDC request failed*/
3875                 dev_err(&device->cdev->dev,
3876                          "An error occurred in the DASD device driver, "
3877                          "reason=%s\n", "13");
3878                 return cqr;
3879         }
3880
3881         ccw = cqr->cpaddr;
3882         ccw->cmd_code = CCW_CMD_RDC;
3883         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3884                 idaw = (unsigned long *) (cqr->data);
3885                 ccw->cda = (__u32)(addr_t) idaw;
3886                 ccw->flags = CCW_FLAG_IDA;
3887                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3888         } else {
3889                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3890                 ccw->flags = 0;
3891         }
3892
3893         ccw->count = rdc_buffer_size;
3894         cqr->startdev = device;
3895         cqr->memdev = device;
3896         cqr->expires = 10*HZ;
3897         cqr->retries = 256;
3898         cqr->buildclk = get_tod_clock();
3899         cqr->status = DASD_CQR_FILLED;
3900         return cqr;
3901 }
3902
3903
3904 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3905                                 void *rdc_buffer, int rdc_buffer_size)
3906 {
3907         int ret;
3908         struct dasd_ccw_req *cqr;
3909
3910         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3911                                      magic);
3912         if (IS_ERR(cqr))
3913                 return PTR_ERR(cqr);
3914
3915         ret = dasd_sleep_on(cqr);
3916         dasd_sfree_request(cqr, cqr->memdev);
3917         return ret;
3918 }
3919 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3920
3921 /*
3922  *   In command mode and transport mode we need to look for sense
3923  *   data in different places. The sense data itself is allways
3924  *   an array of 32 bytes, so we can unify the sense data access
3925  *   for both modes.
3926  */
3927 char *dasd_get_sense(struct irb *irb)
3928 {
3929         struct tsb *tsb = NULL;
3930         char *sense = NULL;
3931
3932         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3933                 if (irb->scsw.tm.tcw)
3934                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3935                                           irb->scsw.tm.tcw);
3936                 if (tsb && tsb->length == 64 && tsb->flags)
3937                         switch (tsb->flags & 0x07) {
3938                         case 1: /* tsa_iostat */
3939                                 sense = tsb->tsa.iostat.sense;
3940                                 break;
3941                         case 2: /* tsa_ddpc */
3942                                 sense = tsb->tsa.ddpc.sense;
3943                                 break;
3944                         default:
3945                                 /* currently we don't use interrogate data */
3946                                 break;
3947                         }
3948         } else if (irb->esw.esw0.erw.cons) {
3949                 sense = irb->ecw;
3950         }
3951         return sense;
3952 }
3953 EXPORT_SYMBOL_GPL(dasd_get_sense);
3954
3955 void dasd_generic_shutdown(struct ccw_device *cdev)
3956 {
3957         struct dasd_device *device;
3958
3959         device = dasd_device_from_cdev(cdev);
3960         if (IS_ERR(device))
3961                 return;
3962
3963         if (device->block)
3964                 dasd_schedule_block_bh(device->block);
3965
3966         dasd_schedule_device_bh(device);
3967
3968         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3969 }
3970 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3971
3972 static int __init dasd_init(void)
3973 {
3974         int rc;
3975
3976         init_waitqueue_head(&dasd_init_waitq);
3977         init_waitqueue_head(&dasd_flush_wq);
3978         init_waitqueue_head(&generic_waitq);
3979         init_waitqueue_head(&shutdown_waitq);
3980
3981         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3982         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3983         if (dasd_debug_area == NULL) {
3984                 rc = -ENOMEM;
3985                 goto failed;
3986         }
3987         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3988         debug_set_level(dasd_debug_area, DBF_WARNING);
3989
3990         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3991
3992         dasd_diag_discipline_pointer = NULL;
3993
3994         dasd_statistics_createroot();
3995
3996         rc = dasd_devmap_init();
3997         if (rc)
3998                 goto failed;
3999         rc = dasd_gendisk_init();
4000         if (rc)
4001                 goto failed;
4002         rc = dasd_parse();
4003         if (rc)
4004                 goto failed;
4005         rc = dasd_eer_init();
4006         if (rc)
4007                 goto failed;
4008 #ifdef CONFIG_PROC_FS
4009         rc = dasd_proc_init();
4010         if (rc)
4011                 goto failed;
4012 #endif
4013
4014         return 0;
4015 failed:
4016         pr_info("The DASD device driver could not be initialized\n");
4017         dasd_exit();
4018         return rc;
4019 }
4020
4021 module_init(dasd_init);
4022 module_exit(dasd_exit);