drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_SLEEPON_START_TAG  (void *) 1
  43 #define DASD_SLEEPON_END_TAG    (void *) 2
  44
  45 /*
  46  * SECTION: exported variables of dasd.c
  47  */
  48 debug_info_t *dasd_debug_area;
  49 static struct dentry *dasd_debugfs_root_entry;
  50 struct dasd_discipline *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 2000 IBM Corporation");
  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
  79 /*
  80  * SECTION: Operations on the device structure.
  81  */
  82 static wait_queue_head_t dasd_init_waitq;
  83 static wait_queue_head_t dasd_flush_wq;
  84 static wait_queue_head_t generic_waitq;
  85 static wait_queue_head_t shutdown_waitq;
  86
  87 /*
  88  * Allocate memory for a new device structure.
  89  */
  90 struct dasd_device *dasd_alloc_device(void)
  91 {
  92         struct dasd_device *device;
  93
  94         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  95         if (!device)
  96                 return ERR_PTR(-ENOMEM);
  97
  98         /* Get two pages for normal block device operations. */
  99         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 100         if (!device->ccw_mem) {
 101                 kfree(device);
 102                 return ERR_PTR(-ENOMEM);
 103         }
 104         /* Get one page for error recovery. */
 105         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 106         if (!device->erp_mem) {
 107                 free_pages((unsigned long) device->ccw_mem, 1);
 108                 kfree(device);
 109                 return ERR_PTR(-ENOMEM);
 110         }
 111
 112         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 113         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 114         spin_lock_init(&device->mem_lock);
 115         atomic_set(&device->tasklet_scheduled, 0);
 116         tasklet_init(&device->tasklet,
 117                      (void (*)(unsigned long)) dasd_device_tasklet,
 118                      (unsigned long) device);
 119         INIT_LIST_HEAD(&device->ccw_queue);
 120         init_timer(&device->timer);
 121         device->timer.function = dasd_device_timeout;
 122         device->timer.data = (unsigned long) device;
 123         INIT_WORK(&device->kick_work, do_kick_device);
 124         INIT_WORK(&device->restore_device, do_restore_device);
 125         INIT_WORK(&device->reload_device, do_reload_device);
 126         device->state = DASD_STATE_NEW;
 127         device->target = DASD_STATE_NEW;
 128         mutex_init(&device->state_mutex);
 129         spin_lock_init(&device->profile.lock);
 130         return device;
 131 }
 132
 133 /*
 134  * Free memory of a device structure.
 135  */
 136 void dasd_free_device(struct dasd_device *device)
 137 {
 138         kfree(device->private);
 139         free_page((unsigned long) device->erp_mem);
 140         free_pages((unsigned long) device->ccw_mem, 1);
 141         kfree(device);
 142 }
 143
 144 /*
 145  * Allocate memory for a new device structure.
 146  */
 147 struct dasd_block *dasd_alloc_block(void)
 148 {
 149         struct dasd_block *block;
 150
 151         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 152         if (!block)
 153                 return ERR_PTR(-ENOMEM);
 154         /* open_count = 0 means device online but not in use */
 155         atomic_set(&block->open_count, -1);
 156
 157         spin_lock_init(&block->request_queue_lock);
 158         atomic_set(&block->tasklet_scheduled, 0);
 159         tasklet_init(&block->tasklet,
 160                      (void (*)(unsigned long)) dasd_block_tasklet,
 161                      (unsigned long) block);
 162         INIT_LIST_HEAD(&block->ccw_queue);
 163         spin_lock_init(&block->queue_lock);
 164         init_timer(&block->timer);
 165         block->timer.function = dasd_block_timeout;
 166         block->timer.data = (unsigned long) block;
 167         spin_lock_init(&block->profile.lock);
 168
 169         return block;
 170 }
 171
 172 /*
 173  * Free memory of a device structure.
 174  */
 175 void dasd_free_block(struct dasd_block *block)
 176 {
 177         kfree(block);
 178 }
 179
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         int rc;
 186
 187         /*
 188          * As long as the device is not in state DASD_STATE_NEW we want to
 189          * keep the reference count > 0.
 190          */
 191         dasd_get_device(device);
 192
 193         if (device->block) {
 194                 rc = dasd_alloc_queue(device->block);
 195                 if (rc) {
 196                         dasd_put_device(device);
 197                         return rc;
 198                 }
 199         }
 200         device->state = DASD_STATE_KNOWN;
 201         return 0;
 202 }
 203
 204 /*
 205  * Let the system forget about a device.
 206  */
 207 static int dasd_state_known_to_new(struct dasd_device *device)
 208 {
 209         /* Disable extended error reporting for this device. */
 210         dasd_eer_disable(device);
 211         /* Forget the discipline information. */
 212         if (device->discipline) {
 213                 if (device->discipline->uncheck_device)
 214                         device->discipline->uncheck_device(device);
 215                 module_put(device->discipline->owner);
 216         }
 217         device->discipline = NULL;
 218         if (device->base_discipline)
 219                 module_put(device->base_discipline->owner);
 220         device->base_discipline = NULL;
 221         device->state = DASD_STATE_NEW;
 222
 223         if (device->block)
 224                 dasd_free_queue(device->block);
 225
 226         /* Give up reference we took in dasd_state_new_to_known. */
 227         dasd_put_device(device);
 228         return 0;
 229 }
 230
 231 static struct dentry *dasd_debugfs_setup(const char *name,
 232                                          struct dentry *base_dentry)
 233 {
 234         struct dentry *pde;
 235
 236         if (!base_dentry)
 237                 return NULL;
 238         pde = debugfs_create_dir(name, base_dentry);
 239         if (!pde || IS_ERR(pde))
 240                 return NULL;
 241         return pde;
 242 }
 243
 244 /*
 245  * Request the irq line for the device.
 246  */
 247 static int dasd_state_known_to_basic(struct dasd_device *device)
 248 {
 249         struct dasd_block *block = device->block;
 250         int rc;
 251
 252         /* Allocate and register gendisk structure. */
 253         if (block) {
 254                 rc = dasd_gendisk_alloc(block);
 255                 if (rc)
 256                         return rc;
 257                 block->debugfs_dentry =
 258                         dasd_debugfs_setup(block->gdp->disk_name,
 259                                            dasd_debugfs_root_entry);
 260                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 261                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 262                         dasd_profile_on(&device->block->profile);
 263         }
 264         device->debugfs_dentry =
 265                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 266                                    dasd_debugfs_root_entry);
 267         dasd_profile_init(&device->profile, device->debugfs_dentry);
 268
 269         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 270         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 271                                             8 * sizeof(long));
 272         debug_register_view(device->debug_area, &debug_sprintf_view);
 273         debug_set_level(device->debug_area, DBF_WARNING);
 274         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 275
 276         device->state = DASD_STATE_BASIC;
 277         return 0;
 278 }
 279
 280 /*
 281  * Release the irq line for the device. Terminate any running i/o.
 282  */
 283 static int dasd_state_basic_to_known(struct dasd_device *device)
 284 {
 285         int rc;
 286         if (device->block) {
 287                 dasd_profile_exit(&device->block->profile);
 288                 if (device->block->debugfs_dentry)
 289                         debugfs_remove(device->block->debugfs_dentry);
 290                 dasd_gendisk_free(device->block);
 291                 dasd_block_clear_timer(device->block);
 292         }
 293         rc = dasd_flush_device_queue(device);
 294         if (rc)
 295                 return rc;
 296         dasd_device_clear_timer(device);
 297         dasd_profile_exit(&device->profile);
 298         if (device->debugfs_dentry)
 299                 debugfs_remove(device->debugfs_dentry);
 300
 301         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 302         if (device->debug_area != NULL) {
 303                 debug_unregister(device->debug_area);
 304                 device->debug_area = NULL;
 305         }
 306         device->state = DASD_STATE_KNOWN;
 307         return 0;
 308 }
 309
 310 /*
 311  * Do the initial analysis. The do_analysis function may return
 312  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 313  * until the discipline decides to continue the startup sequence
 314  * by calling the function dasd_change_state. The eckd disciplines
 315  * uses this to start a ccw that detects the format. The completion
 316  * interrupt for this detection ccw uses the kernel event daemon to
 317  * trigger the call to dasd_change_state. All this is done in the
 318  * discipline code, see dasd_eckd.c.
 319  * After the analysis ccw is done (do_analysis returned 0) the block
 320  * device is setup.
 321  * In case the analysis returns an error, the device setup is stopped
 322  * (a fake disk was already added to allow formatting).
 323  */
 324 static int dasd_state_basic_to_ready(struct dasd_device *device)
 325 {
 326         int rc;
 327         struct dasd_block *block;
 328
 329         rc = 0;
 330         block = device->block;
 331         /* make disk known with correct capacity */
 332         if (block) {
 333                 if (block->base->discipline->do_analysis != NULL)
 334                         rc = block->base->discipline->do_analysis(block);
 335                 if (rc) {
 336                         if (rc != -EAGAIN)
 337                                 device->state = DASD_STATE_UNFMT;
 338                         return rc;
 339                 }
 340                 dasd_setup_queue(block);
 341                 set_capacity(block->gdp,
 342                              block->blocks << block->s2b_shift);
 343                 device->state = DASD_STATE_READY;
 344                 rc = dasd_scan_partitions(block);
 345                 if (rc)
 346                         device->state = DASD_STATE_BASIC;
 347         } else {
 348                 device->state = DASD_STATE_READY;
 349         }
 350         return rc;
 351 }
 352
 353 /*
 354  * Remove device from block device layer. Destroy dirty buffers.
 355  * Forget format information. Check if the target level is basic
 356  * and if it is create fake disk for formatting.
 357  */
 358 static int dasd_state_ready_to_basic(struct dasd_device *device)
 359 {
 360         int rc;
 361
 362         device->state = DASD_STATE_BASIC;
 363         if (device->block) {
 364                 struct dasd_block *block = device->block;
 365                 rc = dasd_flush_block_queue(block);
 366                 if (rc) {
 367                         device->state = DASD_STATE_READY;
 368                         return rc;
 369                 }
 370                 dasd_flush_request_queue(block);
 371                 dasd_destroy_partitions(block);
 372                 block->blocks = 0;
 373                 block->bp_block = 0;
 374                 block->s2b_shift = 0;
 375         }
 376         return 0;
 377 }
 378
 379 /*
 380  * Back to basic.
 381  */
 382 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 383 {
 384         device->state = DASD_STATE_BASIC;
 385         return 0;
 386 }
 387
 388 /*
 389  * Make the device online and schedule the bottom half to start
 390  * the requeueing of requests from the linux request queue to the
 391  * ccw queue.
 392  */
 393 static int
 394 dasd_state_ready_to_online(struct dasd_device * device)
 395 {
 396         int rc;
 397         struct gendisk *disk;
 398         struct disk_part_iter piter;
 399         struct hd_struct *part;
 400
 401         if (device->discipline->ready_to_online) {
 402                 rc = device->discipline->ready_to_online(device);
 403                 if (rc)
 404                         return rc;
 405         }
 406         device->state = DASD_STATE_ONLINE;
 407         if (device->block) {
 408                 dasd_schedule_block_bh(device->block);
 409                 if ((device->features & DASD_FEATURE_USERAW)) {
 410                         disk = device->block->gdp;
 411                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 412                         return 0;
 413                 }
 414                 disk = device->block->bdev->bd_disk;
 415                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 416                 while ((part = disk_part_iter_next(&piter)))
 417                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 418                 disk_part_iter_exit(&piter);
 419         }
 420         return 0;
 421 }
 422
 423 /*
 424  * Stop the requeueing of requests again.
 425  */
 426 static int dasd_state_online_to_ready(struct dasd_device *device)
 427 {
 428         int rc;
 429         struct gendisk *disk;
 430         struct disk_part_iter piter;
 431         struct hd_struct *part;
 432
 433         if (device->discipline->online_to_ready) {
 434                 rc = device->discipline->online_to_ready(device);
 435                 if (rc)
 436                         return rc;
 437         }
 438         device->state = DASD_STATE_READY;
 439         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 440                 disk = device->block->bdev->bd_disk;
 441                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 442                 while ((part = disk_part_iter_next(&piter)))
 443                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 444                 disk_part_iter_exit(&piter);
 445         }
 446         return 0;
 447 }
 448
 449 /*
 450  * Device startup state changes.
 451  */
 452 static int dasd_increase_state(struct dasd_device *device)
 453 {
 454         int rc;
 455
 456         rc = 0;
 457         if (device->state == DASD_STATE_NEW &&
 458             device->target >= DASD_STATE_KNOWN)
 459                 rc = dasd_state_new_to_known(device);
 460
 461         if (!rc &&
 462             device->state == DASD_STATE_KNOWN &&
 463             device->target >= DASD_STATE_BASIC)
 464                 rc = dasd_state_known_to_basic(device);
 465
 466         if (!rc &&
 467             device->state == DASD_STATE_BASIC &&
 468             device->target >= DASD_STATE_READY)
 469                 rc = dasd_state_basic_to_ready(device);
 470
 471         if (!rc &&
 472             device->state == DASD_STATE_UNFMT &&
 473             device->target > DASD_STATE_UNFMT)
 474                 rc = -EPERM;
 475
 476         if (!rc &&
 477             device->state == DASD_STATE_READY &&
 478             device->target >= DASD_STATE_ONLINE)
 479                 rc = dasd_state_ready_to_online(device);
 480
 481         return rc;
 482 }
 483
 484 /*
 485  * Device shutdown state changes.
 486  */
 487 static int dasd_decrease_state(struct dasd_device *device)
 488 {
 489         int rc;
 490
 491         rc = 0;
 492         if (device->state == DASD_STATE_ONLINE &&
 493             device->target <= DASD_STATE_READY)
 494                 rc = dasd_state_online_to_ready(device);
 495
 496         if (!rc &&
 497             device->state == DASD_STATE_READY &&
 498             device->target <= DASD_STATE_BASIC)
 499                 rc = dasd_state_ready_to_basic(device);
 500
 501         if (!rc &&
 502             device->state == DASD_STATE_UNFMT &&
 503             device->target <= DASD_STATE_BASIC)
 504                 rc = dasd_state_unfmt_to_basic(device);
 505
 506         if (!rc &&
 507             device->state == DASD_STATE_BASIC &&
 508             device->target <= DASD_STATE_KNOWN)
 509                 rc = dasd_state_basic_to_known(device);
 510
 511         if (!rc &&
 512             device->state == DASD_STATE_KNOWN &&
 513             device->target <= DASD_STATE_NEW)
 514                 rc = dasd_state_known_to_new(device);
 515
 516         return rc;
 517 }
 518
 519 /*
 520  * This is the main startup/shutdown routine.
 521  */
 522 static void dasd_change_state(struct dasd_device *device)
 523 {
 524         int rc;
 525
 526         if (device->state == device->target)
 527                 /* Already where we want to go today... */
 528                 return;
 529         if (device->state < device->target)
 530                 rc = dasd_increase_state(device);
 531         else
 532                 rc = dasd_decrease_state(device);
 533         if (rc == -EAGAIN)
 534                 return;
 535         if (rc)
 536                 device->target = device->state;
 537
 538         if (device->state == device->target)
 539                 wake_up(&dasd_init_waitq);
 540
 541         /* let user-space know that the device status changed */
 542         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 543 }
 544
 545 /*
 546  * Kick starter for devices that did not complete the startup/shutdown
 547  * procedure or were sleeping because of a pending state.
 548  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 549  * event daemon.
 550  */
 551 static void do_kick_device(struct work_struct *work)
 552 {
 553         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 554         mutex_lock(&device->state_mutex);
 555         dasd_change_state(device);
 556         mutex_unlock(&device->state_mutex);
 557         dasd_schedule_device_bh(device);
 558         dasd_put_device(device);
 559 }
 560
 561 void dasd_kick_device(struct dasd_device *device)
 562 {
 563         dasd_get_device(device);
 564         /* queue call to dasd_kick_device to the kernel event daemon. */
 565         schedule_work(&device->kick_work);
 566 }
 567
 568 /*
 569  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 570  * event daemon.
 571  */
 572 static void do_reload_device(struct work_struct *work)
 573 {
 574         struct dasd_device *device = container_of(work, struct dasd_device,
 575                                                   reload_device);
 576         device->discipline->reload(device);
 577         dasd_put_device(device);
 578 }
 579
 580 void dasd_reload_device(struct dasd_device *device)
 581 {
 582         dasd_get_device(device);
 583         /* queue call to dasd_reload_device to the kernel event daemon. */
 584         schedule_work(&device->reload_device);
 585 }
 586 EXPORT_SYMBOL(dasd_reload_device);
 587
 588 /*
 589  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 590  * event daemon.
 591  */
 592 static void do_restore_device(struct work_struct *work)
 593 {
 594         struct dasd_device *device = container_of(work, struct dasd_device,
 595                                                   restore_device);
 596         device->cdev->drv->restore(device->cdev);
 597         dasd_put_device(device);
 598 }
 599
 600 void dasd_restore_device(struct dasd_device *device)
 601 {
 602         dasd_get_device(device);
 603         /* queue call to dasd_restore_device to the kernel event daemon. */
 604         schedule_work(&device->restore_device);
 605 }
 606
 607 /*
 608  * Set the target state for a device and starts the state change.
 609  */
 610 void dasd_set_target_state(struct dasd_device *device, int target)
 611 {
 612         dasd_get_device(device);
 613         mutex_lock(&device->state_mutex);
 614         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 615         if (dasd_probeonly && target > DASD_STATE_READY)
 616                 target = DASD_STATE_READY;
 617         if (device->target != target) {
 618                 if (device->state == target)
 619                         wake_up(&dasd_init_waitq);
 620                 device->target = target;
 621         }
 622         if (device->state != device->target)
 623                 dasd_change_state(device);
 624         mutex_unlock(&device->state_mutex);
 625         dasd_put_device(device);
 626 }
 627
 628 /*
 629  * Enable devices with device numbers in [from..to].
 630  */
 631 static inline int _wait_for_device(struct dasd_device *device)
 632 {
 633         return (device->state == device->target);
 634 }
 635
 636 void dasd_enable_device(struct dasd_device *device)
 637 {
 638         dasd_set_target_state(device, DASD_STATE_ONLINE);
 639         if (device->state <= DASD_STATE_KNOWN)
 640                 /* No discipline for device found. */
 641                 dasd_set_target_state(device, DASD_STATE_NEW);
 642         /* Now wait for the devices to come up. */
 643         wait_event(dasd_init_waitq, _wait_for_device(device));
 644
 645         dasd_reload_device(device);
 646         if (device->discipline->kick_validate)
 647                 device->discipline->kick_validate(device);
 648 }
 649
 650 /*
 651  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 652  */
 653
 654 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 655
 656 #ifdef CONFIG_DASD_PROFILE
 657 struct dasd_profile_info dasd_global_profile_data;
 658 static struct dentry *dasd_global_profile_dentry;
 659 static struct dentry *dasd_debugfs_global_entry;
 660
 661 /*
 662  * Add profiling information for cqr before execution.
 663  */
 664 static void dasd_profile_start(struct dasd_block *block,
 665                                struct dasd_ccw_req *cqr,
 666                                struct request *req)
 667 {
 668         struct list_head *l;
 669         unsigned int counter;
 670         struct dasd_device *device;
 671
 672         /* count the length of the chanq for statistics */
 673         counter = 0;
 674         if (dasd_global_profile_level || block->profile.data)
 675                 list_for_each(l, &block->ccw_queue)
 676                         if (++counter >= 31)
 677                                 break;
 678
 679         if (dasd_global_profile_level) {
 680                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 681                 if (rq_data_dir(req) == READ)
 682                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 683         }
 684
 685         spin_lock(&block->profile.lock);
 686         if (block->profile.data)
 687                 block->profile.data->dasd_io_nr_req[counter]++;
 688                 if (rq_data_dir(req) == READ)
 689                         block->profile.data->dasd_read_nr_req[counter]++;
 690         spin_unlock(&block->profile.lock);
 691
 692         /*
 693          * We count the request for the start device, even though it may run on
 694          * some other device due to error recovery. This way we make sure that
 695          * we count each request only once.
 696          */
 697         device = cqr->startdev;
 698         if (device->profile.data) {
 699                 counter = 1; /* request is not yet queued on the start device */
 700                 list_for_each(l, &device->ccw_queue)
 701                         if (++counter >= 31)
 702                                 break;
 703         }
 704         spin_lock(&device->profile.lock);
 705         if (device->profile.data) {
 706                 device->profile.data->dasd_io_nr_req[counter]++;
 707                 if (rq_data_dir(req) == READ)
 708                         device->profile.data->dasd_read_nr_req[counter]++;
 709         }
 710         spin_unlock(&device->profile.lock);
 711 }
 712
 713 /*
 714  * Add profiling information for cqr after execution.
 715  */
 716
 717 #define dasd_profile_counter(value, index)                         \
 718 {                                                                  \
 719         for (index = 0; index < 31 && value >> (2+index); index++) \
 720                 ;                                                  \
 721 }
 722
 723 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 724                                       int is_alias,
 725                                       int is_tpm,
 726                                       int is_read,
 727                                       long sectors,
 728                                       int sectors_ind,
 729                                       int tottime_ind,
 730                                       int tottimeps_ind,
 731                                       int strtime_ind,
 732                                       int irqtime_ind,
 733                                       int irqtimeps_ind,
 734                                       int endtime_ind)
 735 {
 736         /* in case of an overflow, reset the whole profile */
 737         if (data->dasd_io_reqs == UINT_MAX) {
 738                         memset(data, 0, sizeof(*data));
 739                         getnstimeofday(&data->starttod);
 740         }
 741         data->dasd_io_reqs++;
 742         data->dasd_io_sects += sectors;
 743         if (is_alias)
 744                 data->dasd_io_alias++;
 745         if (is_tpm)
 746                 data->dasd_io_tpm++;
 747
 748         data->dasd_io_secs[sectors_ind]++;
 749         data->dasd_io_times[tottime_ind]++;
 750         data->dasd_io_timps[tottimeps_ind]++;
 751         data->dasd_io_time1[strtime_ind]++;
 752         data->dasd_io_time2[irqtime_ind]++;
 753         data->dasd_io_time2ps[irqtimeps_ind]++;
 754         data->dasd_io_time3[endtime_ind]++;
 755
 756         if (is_read) {
 757                 data->dasd_read_reqs++;
 758                 data->dasd_read_sects += sectors;
 759                 if (is_alias)
 760                         data->dasd_read_alias++;
 761                 if (is_tpm)
 762                         data->dasd_read_tpm++;
 763                 data->dasd_read_secs[sectors_ind]++;
 764                 data->dasd_read_times[tottime_ind]++;
 765                 data->dasd_read_time1[strtime_ind]++;
 766                 data->dasd_read_time2[irqtime_ind]++;
 767                 data->dasd_read_time3[endtime_ind]++;
 768         }
 769 }
 770
 771 static void dasd_profile_end(struct dasd_block *block,
 772                              struct dasd_ccw_req *cqr,
 773                              struct request *req)
 774 {
 775         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 776         long tottimeps, sectors;
 777         struct dasd_device *device;
 778         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 779         int irqtime_ind, irqtimeps_ind, endtime_ind;
 780
 781         device = cqr->startdev;
 782         if (!(dasd_global_profile_level ||
 783               block->profile.data ||
 784               device->profile.data))
 785                 return;
 786
 787         sectors = blk_rq_sectors(req);
 788         if (!cqr->buildclk || !cqr->startclk ||
 789             !cqr->stopclk || !cqr->endclk ||
 790             !sectors)
 791                 return;
 792
 793         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 794         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 795         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 796         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 797         tottimeps = tottime / sectors;
 798
 799         dasd_profile_counter(sectors, sectors_ind);
 800         dasd_profile_counter(tottime, tottime_ind);
 801         dasd_profile_counter(tottimeps, tottimeps_ind);
 802         dasd_profile_counter(strtime, strtime_ind);
 803         dasd_profile_counter(irqtime, irqtime_ind);
 804         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 805         dasd_profile_counter(endtime, endtime_ind);
 806
 807         if (dasd_global_profile_level) {
 808                 dasd_profile_end_add_data(&dasd_global_profile_data,
 809                                           cqr->startdev != block->base,
 810                                           cqr->cpmode == 1,
 811                                           rq_data_dir(req) == READ,
 812                                           sectors, sectors_ind, tottime_ind,
 813                                           tottimeps_ind, strtime_ind,
 814                                           irqtime_ind, irqtimeps_ind,
 815                                           endtime_ind);
 816         }
 817
 818         spin_lock(&block->profile.lock);
 819         if (block->profile.data)
 820                 dasd_profile_end_add_data(block->profile.data,
 821                                           cqr->startdev != block->base,
 822                                           cqr->cpmode == 1,
 823                                           rq_data_dir(req) == READ,
 824                                           sectors, sectors_ind, tottime_ind,
 825                                           tottimeps_ind, strtime_ind,
 826                                           irqtime_ind, irqtimeps_ind,
 827                                           endtime_ind);
 828         spin_unlock(&block->profile.lock);
 829
 830         spin_lock(&device->profile.lock);
 831         if (device->profile.data)
 832                 dasd_profile_end_add_data(device->profile.data,
 833                                           cqr->startdev != block->base,
 834                                           cqr->cpmode == 1,
 835                                           rq_data_dir(req) == READ,
 836                                           sectors, sectors_ind, tottime_ind,
 837                                           tottimeps_ind, strtime_ind,
 838                                           irqtime_ind, irqtimeps_ind,
 839                                           endtime_ind);
 840         spin_unlock(&device->profile.lock);
 841 }
 842
 843 void dasd_profile_reset(struct dasd_profile *profile)
 844 {
 845         struct dasd_profile_info *data;
 846
 847         spin_lock_bh(&profile->lock);
 848         data = profile->data;
 849         if (!data) {
 850                 spin_unlock_bh(&profile->lock);
 851                 return;
 852         }
 853         memset(data, 0, sizeof(*data));
 854         getnstimeofday(&data->starttod);
 855         spin_unlock_bh(&profile->lock);
 856 }
 857
 858 void dasd_global_profile_reset(void)
 859 {
 860         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 861         getnstimeofday(&dasd_global_profile_data.starttod);
 862 }
 863
 864 int dasd_profile_on(struct dasd_profile *profile)
 865 {
 866         struct dasd_profile_info *data;
 867
 868         data = kzalloc(sizeof(*data), GFP_KERNEL);
 869         if (!data)
 870                 return -ENOMEM;
 871         spin_lock_bh(&profile->lock);
 872         if (profile->data) {
 873                 spin_unlock_bh(&profile->lock);
 874                 kfree(data);
 875                 return 0;
 876         }
 877         getnstimeofday(&data->starttod);
 878         profile->data = data;
 879         spin_unlock_bh(&profile->lock);
 880         return 0;
 881 }
 882
 883 void dasd_profile_off(struct dasd_profile *profile)
 884 {
 885         spin_lock_bh(&profile->lock);
 886         kfree(profile->data);
 887         profile->data = NULL;
 888         spin_unlock_bh(&profile->lock);
 889 }
 890
 891 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 892 {
 893         char *buffer;
 894
 895         buffer = vmalloc(user_len + 1);
 896         if (buffer == NULL)
 897                 return ERR_PTR(-ENOMEM);
 898         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 899                 vfree(buffer);
 900                 return ERR_PTR(-EFAULT);
 901         }
 902         /* got the string, now strip linefeed. */
 903         if (buffer[user_len - 1] == '\n')
 904                 buffer[user_len - 1] = 0;
 905         else
 906                 buffer[user_len] = 0;
 907         return buffer;
 908 }
 909
 910 static ssize_t dasd_stats_write(struct file *file,
 911                                 const char __user *user_buf,
 912                                 size_t user_len, loff_t *pos)
 913 {
 914         char *buffer, *str;
 915         int rc;
 916         struct seq_file *m = (struct seq_file *)file->private_data;
 917         struct dasd_profile *prof = m->private;
 918
 919         if (user_len > 65536)
 920                 user_len = 65536;
 921         buffer = dasd_get_user_string(user_buf, user_len);
 922         if (IS_ERR(buffer))
 923                 return PTR_ERR(buffer);
 924
 925         str = skip_spaces(buffer);
 926         rc = user_len;
 927         if (strncmp(str, "reset", 5) == 0) {
 928                 dasd_profile_reset(prof);
 929         } else if (strncmp(str, "on", 2) == 0) {
 930                 rc = dasd_profile_on(prof);
 931                 if (!rc)
 932                         rc = user_len;
 933         } else if (strncmp(str, "off", 3) == 0) {
 934                 dasd_profile_off(prof);
 935         } else
 936                 rc = -EINVAL;
 937         vfree(buffer);
 938         return rc;
 939 }
 940
 941 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 942 {
 943         int i;
 944
 945         for (i = 0; i < 32; i++)
 946                 seq_printf(m, "%u ", array[i]);
 947         seq_putc(m, '\n');
 948 }
 949
 950 static void dasd_stats_seq_print(struct seq_file *m,
 951                                  struct dasd_profile_info *data)
 952 {
 953         seq_printf(m, "start_time %ld.%09ld\n",
 954                    data->starttod.tv_sec, data->starttod.tv_nsec);
 955         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 956         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 957         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 958         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 959         seq_printf(m, "histogram_sectors ");
 960         dasd_stats_array(m, data->dasd_io_secs);
 961         seq_printf(m, "histogram_io_times ");
 962         dasd_stats_array(m, data->dasd_io_times);
 963         seq_printf(m, "histogram_io_times_weighted ");
 964         dasd_stats_array(m, data->dasd_io_timps);
 965         seq_printf(m, "histogram_time_build_to_ssch ");
 966         dasd_stats_array(m, data->dasd_io_time1);
 967         seq_printf(m, "histogram_time_ssch_to_irq ");
 968         dasd_stats_array(m, data->dasd_io_time2);
 969         seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
 970         dasd_stats_array(m, data->dasd_io_time2ps);
 971         seq_printf(m, "histogram_time_irq_to_end ");
 972         dasd_stats_array(m, data->dasd_io_time3);
 973         seq_printf(m, "histogram_ccw_queue_length ");
 974         dasd_stats_array(m, data->dasd_io_nr_req);
 975         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 976         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 977         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 978         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 979         seq_printf(m, "histogram_read_sectors ");
 980         dasd_stats_array(m, data->dasd_read_secs);
 981         seq_printf(m, "histogram_read_times ");
 982         dasd_stats_array(m, data->dasd_read_times);
 983         seq_printf(m, "histogram_read_time_build_to_ssch ");
 984         dasd_stats_array(m, data->dasd_read_time1);
 985         seq_printf(m, "histogram_read_time_ssch_to_irq ");
 986         dasd_stats_array(m, data->dasd_read_time2);
 987         seq_printf(m, "histogram_read_time_irq_to_end ");
 988         dasd_stats_array(m, data->dasd_read_time3);
 989         seq_printf(m, "histogram_read_ccw_queue_length ");
 990         dasd_stats_array(m, data->dasd_read_nr_req);
 991 }
 992
 993 static int dasd_stats_show(struct seq_file *m, void *v)
 994 {
 995         struct dasd_profile *profile;
 996         struct dasd_profile_info *data;
 997
 998         profile = m->private;
 999         spin_lock_bh(&profile->lock);
1000         data = profile->data;
1001         if (!data) {
1002                 spin_unlock_bh(&profile->lock);
1003                 seq_printf(m, "disabled\n");
1004                 return 0;
1005         }
1006         dasd_stats_seq_print(m, data);
1007         spin_unlock_bh(&profile->lock);
1008         return 0;
1009 }
1010
1011 static int dasd_stats_open(struct inode *inode, struct file *file)
1012 {
1013         struct dasd_profile *profile = inode->i_private;
1014         return single_open(file, dasd_stats_show, profile);
1015 }
1016
1017 static const struct file_operations dasd_stats_raw_fops = {
1018         .owner          = THIS_MODULE,
1019         .open           = dasd_stats_open,
1020         .read           = seq_read,
1021         .llseek         = seq_lseek,
1022         .release        = single_release,
1023         .write          = dasd_stats_write,
1024 };
1025
1026 static ssize_t dasd_stats_global_write(struct file *file,
1027                                        const char __user *user_buf,
1028                                        size_t user_len, loff_t *pos)
1029 {
1030         char *buffer, *str;
1031         ssize_t rc;
1032
1033         if (user_len > 65536)
1034                 user_len = 65536;
1035         buffer = dasd_get_user_string(user_buf, user_len);
1036         if (IS_ERR(buffer))
1037                 return PTR_ERR(buffer);
1038         str = skip_spaces(buffer);
1039         rc = user_len;
1040         if (strncmp(str, "reset", 5) == 0) {
1041                 dasd_global_profile_reset();
1042         } else if (strncmp(str, "on", 2) == 0) {
1043                 dasd_global_profile_reset();
1044                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1045         } else if (strncmp(str, "off", 3) == 0) {
1046                 dasd_global_profile_level = DASD_PROFILE_OFF;
1047         } else
1048                 rc = -EINVAL;
1049         vfree(buffer);
1050         return rc;
1051 }
1052
1053 static int dasd_stats_global_show(struct seq_file *m, void *v)
1054 {
1055         if (!dasd_global_profile_level) {
1056                 seq_printf(m, "disabled\n");
1057                 return 0;
1058         }
1059         dasd_stats_seq_print(m, &dasd_global_profile_data);
1060         return 0;
1061 }
1062
1063 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1064 {
1065         return single_open(file, dasd_stats_global_show, NULL);
1066 }
1067
1068 static const struct file_operations dasd_stats_global_fops = {
1069         .owner          = THIS_MODULE,
1070         .open           = dasd_stats_global_open,
1071         .read           = seq_read,
1072         .llseek         = seq_lseek,
1073         .release        = single_release,
1074         .write          = dasd_stats_global_write,
1075 };
1076
1077 static void dasd_profile_init(struct dasd_profile *profile,
1078                               struct dentry *base_dentry)
1079 {
1080         umode_t mode;
1081         struct dentry *pde;
1082
1083         if (!base_dentry)
1084                 return;
1085         profile->dentry = NULL;
1086         profile->data = NULL;
1087         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1088         pde = debugfs_create_file("statistics", mode, base_dentry,
1089                                   profile, &dasd_stats_raw_fops);
1090         if (pde && !IS_ERR(pde))
1091                 profile->dentry = pde;
1092         return;
1093 }
1094
1095 static void dasd_profile_exit(struct dasd_profile *profile)
1096 {
1097         dasd_profile_off(profile);
1098         if (profile->dentry) {
1099                 debugfs_remove(profile->dentry);
1100                 profile->dentry = NULL;
1101         }
1102 }
1103
1104 static void dasd_statistics_removeroot(void)
1105 {
1106         dasd_global_profile_level = DASD_PROFILE_OFF;
1107         if (dasd_global_profile_dentry) {
1108                 debugfs_remove(dasd_global_profile_dentry);
1109                 dasd_global_profile_dentry = NULL;
1110         }
1111         if (dasd_debugfs_global_entry)
1112                 debugfs_remove(dasd_debugfs_global_entry);
1113         if (dasd_debugfs_root_entry)
1114                 debugfs_remove(dasd_debugfs_root_entry);
1115 }
1116
1117 static void dasd_statistics_createroot(void)
1118 {
1119         umode_t mode;
1120         struct dentry *pde;
1121
1122         dasd_debugfs_root_entry = NULL;
1123         dasd_debugfs_global_entry = NULL;
1124         dasd_global_profile_dentry = NULL;
1125         pde = debugfs_create_dir("dasd", NULL);
1126         if (!pde || IS_ERR(pde))
1127                 goto error;
1128         dasd_debugfs_root_entry = pde;
1129         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1130         if (!pde || IS_ERR(pde))
1131                 goto error;
1132         dasd_debugfs_global_entry = pde;
1133
1134         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1135         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1136                                   NULL, &dasd_stats_global_fops);
1137         if (!pde || IS_ERR(pde))
1138                 goto error;
1139         dasd_global_profile_dentry = pde;
1140         return;
1141
1142 error:
1143         DBF_EVENT(DBF_ERR, "%s",
1144                   "Creation of the dasd debugfs interface failed");
1145         dasd_statistics_removeroot();
1146         return;
1147 }
1148
1149 #else
1150 #define dasd_profile_start(block, cqr, req) do {} while (0)
1151 #define dasd_profile_end(block, cqr, req) do {} while (0)
1152
1153 static void dasd_statistics_createroot(void)
1154 {
1155         return;
1156 }
1157
1158 static void dasd_statistics_removeroot(void)
1159 {
1160         return;
1161 }
1162
1163 int dasd_stats_generic_show(struct seq_file *m, void *v)
1164 {
1165         seq_printf(m, "Statistics are not activated in this kernel\n");
1166         return 0;
1167 }
1168
1169 static void dasd_profile_init(struct dasd_profile *profile,
1170                               struct dentry *base_dentry)
1171 {
1172         return;
1173 }
1174
1175 static void dasd_profile_exit(struct dasd_profile *profile)
1176 {
1177         return;
1178 }
1179
1180 int dasd_profile_on(struct dasd_profile *profile)
1181 {
1182         return 0;
1183 }
1184
1185 #endif                          /* CONFIG_DASD_PROFILE */
1186
1187 /*
1188  * Allocate memory for a channel program with 'cplength' channel
1189  * command words and 'datasize' additional space. There are two
1190  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1191  * memory and 2) dasd_smalloc_request uses the static ccw memory
1192  * that gets allocated for each device.
1193  */
1194 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1195                                           int datasize,
1196                                           struct dasd_device *device)
1197 {
1198         struct dasd_ccw_req *cqr;
1199
1200         /* Sanity checks */
1201         BUG_ON(datasize > PAGE_SIZE ||
1202              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1203
1204         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1205         if (cqr == NULL)
1206                 return ERR_PTR(-ENOMEM);
1207         cqr->cpaddr = NULL;
1208         if (cplength > 0) {
1209                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1210                                       GFP_ATOMIC | GFP_DMA);
1211                 if (cqr->cpaddr == NULL) {
1212                         kfree(cqr);
1213                         return ERR_PTR(-ENOMEM);
1214                 }
1215         }
1216         cqr->data = NULL;
1217         if (datasize > 0) {
1218                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1219                 if (cqr->data == NULL) {
1220                         kfree(cqr->cpaddr);
1221                         kfree(cqr);
1222                         return ERR_PTR(-ENOMEM);
1223                 }
1224         }
1225         cqr->magic =  magic;
1226         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1227         dasd_get_device(device);
1228         return cqr;
1229 }
1230
1231 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1232                                           int datasize,
1233                                           struct dasd_device *device)
1234 {
1235         unsigned long flags;
1236         struct dasd_ccw_req *cqr;
1237         char *data;
1238         int size;
1239
1240         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1241         if (cplength > 0)
1242                 size += cplength * sizeof(struct ccw1);
1243         if (datasize > 0)
1244                 size += datasize;
1245         spin_lock_irqsave(&device->mem_lock, flags);
1246         cqr = (struct dasd_ccw_req *)
1247                 dasd_alloc_chunk(&device->ccw_chunks, size);
1248         spin_unlock_irqrestore(&device->mem_lock, flags);
1249         if (cqr == NULL)
1250                 return ERR_PTR(-ENOMEM);
1251         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1252         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1253         cqr->cpaddr = NULL;
1254         if (cplength > 0) {
1255                 cqr->cpaddr = (struct ccw1 *) data;
1256                 data += cplength*sizeof(struct ccw1);
1257                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1258         }
1259         cqr->data = NULL;
1260         if (datasize > 0) {
1261                 cqr->data = data;
1262                 memset(cqr->data, 0, datasize);
1263         }
1264         cqr->magic = magic;
1265         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1266         dasd_get_device(device);
1267         return cqr;
1268 }
1269
1270 /*
1271  * Free memory of a channel program. This function needs to free all the
1272  * idal lists that might have been created by dasd_set_cda and the
1273  * struct dasd_ccw_req itself.
1274  */
1275 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1276 {
1277 #ifdef CONFIG_64BIT
1278         struct ccw1 *ccw;
1279
1280         /* Clear any idals used for the request. */
1281         ccw = cqr->cpaddr;
1282         do {
1283                 clear_normalized_cda(ccw);
1284         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1285 #endif
1286         kfree(cqr->cpaddr);
1287         kfree(cqr->data);
1288         kfree(cqr);
1289         dasd_put_device(device);
1290 }
1291
1292 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1293 {
1294         unsigned long flags;
1295
1296         spin_lock_irqsave(&device->mem_lock, flags);
1297         dasd_free_chunk(&device->ccw_chunks, cqr);
1298         spin_unlock_irqrestore(&device->mem_lock, flags);
1299         dasd_put_device(device);
1300 }
1301
1302 /*
1303  * Check discipline magic in cqr.
1304  */
1305 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1306 {
1307         struct dasd_device *device;
1308
1309         if (cqr == NULL)
1310                 return -EINVAL;
1311         device = cqr->startdev;
1312         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1313                 DBF_DEV_EVENT(DBF_WARNING, device,
1314                             " dasd_ccw_req 0x%08x magic doesn't match"
1315                             " discipline 0x%08x",
1316                             cqr->magic,
1317                             *(unsigned int *) device->discipline->name);
1318                 return -EINVAL;
1319         }
1320         return 0;
1321 }
1322
1323 /*
1324  * Terminate the current i/o and set the request to clear_pending.
1325  * Timer keeps device runnig.
1326  * ccw_device_clear can fail if the i/o subsystem
1327  * is in a bad mood.
1328  */
1329 int dasd_term_IO(struct dasd_ccw_req *cqr)
1330 {
1331         struct dasd_device *device;
1332         int retries, rc;
1333         char errorstring[ERRORLENGTH];
1334
1335         /* Check the cqr */
1336         rc = dasd_check_cqr(cqr);
1337         if (rc)
1338                 return rc;
1339         retries = 0;
1340         device = (struct dasd_device *) cqr->startdev;
1341         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1342                 rc = ccw_device_clear(device->cdev, (long) cqr);
1343                 switch (rc) {
1344                 case 0: /* termination successful */
1345                         cqr->status = DASD_CQR_CLEAR_PENDING;
1346                         cqr->stopclk = get_clock();
1347                         cqr->starttime = 0;
1348                         DBF_DEV_EVENT(DBF_DEBUG, device,
1349                                       "terminate cqr %p successful",
1350                                       cqr);
1351                         break;
1352                 case -ENODEV:
1353                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1354                                       "device gone, retry");
1355                         break;
1356                 case -EIO:
1357                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1358                                       "I/O error, retry");
1359                         break;
1360                 case -EINVAL:
1361                 case -EBUSY:
1362                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1363                                       "device busy, retry later");
1364                         break;
1365                 default:
1366                         /* internal error 10 - unknown rc*/
1367                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1368                         dev_err(&device->cdev->dev, "An error occurred in the "
1369                                 "DASD device driver, reason=%s\n", errorstring);
1370                         BUG();
1371                         break;
1372                 }
1373                 retries++;
1374         }
1375         dasd_schedule_device_bh(device);
1376         return rc;
1377 }
1378
1379 /*
1380  * Start the i/o. This start_IO can fail if the channel is really busy.
1381  * In that case set up a timer to start the request later.
1382  */
1383 int dasd_start_IO(struct dasd_ccw_req *cqr)
1384 {
1385         struct dasd_device *device;
1386         int rc;
1387         char errorstring[ERRORLENGTH];
1388
1389         /* Check the cqr */
1390         rc = dasd_check_cqr(cqr);
1391         if (rc) {
1392                 cqr->intrc = rc;
1393                 return rc;
1394         }
1395         device = (struct dasd_device *) cqr->startdev;
1396         if (((cqr->block &&
1397               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1398              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1399             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1400                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1401                               "because of stolen lock", cqr);
1402                 cqr->status = DASD_CQR_ERROR;
1403                 cqr->intrc = -EPERM;
1404                 return -EPERM;
1405         }
1406         if (cqr->retries < 0) {
1407                 /* internal error 14 - start_IO run out of retries */
1408                 sprintf(errorstring, "14 %p", cqr);
1409                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1410                         "device driver, reason=%s\n", errorstring);
1411                 cqr->status = DASD_CQR_ERROR;
1412                 return -EIO;
1413         }
1414         cqr->startclk = get_clock();
1415         cqr->starttime = jiffies;
1416         cqr->retries--;
1417         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1418                 cqr->lpm &= device->path_data.opm;
1419                 if (!cqr->lpm)
1420                         cqr->lpm = device->path_data.opm;
1421         }
1422         if (cqr->cpmode == 1) {
1423                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1424                                          (long) cqr, cqr->lpm);
1425         } else {
1426                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1427                                       (long) cqr, cqr->lpm, 0);
1428         }
1429         switch (rc) {
1430         case 0:
1431                 cqr->status = DASD_CQR_IN_IO;
1432                 break;
1433         case -EBUSY:
1434                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1435                               "start_IO: device busy, retry later");
1436                 break;
1437         case -ETIMEDOUT:
1438                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1439                               "start_IO: request timeout, retry later");
1440                 break;
1441         case -EACCES:
1442                 /* -EACCES indicates that the request used only a subset of the
1443                  * available paths and all these paths are gone. If the lpm of
1444                  * this request was only a subset of the opm (e.g. the ppm) then
1445                  * we just do a retry with all available paths.
1446                  * If we already use the full opm, something is amiss, and we
1447                  * need a full path verification.
1448                  */
1449                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1450                         DBF_DEV_EVENT(DBF_WARNING, device,
1451                                       "start_IO: selected paths gone (%x)",
1452                                       cqr->lpm);
1453                 } else if (cqr->lpm != device->path_data.opm) {
1454                         cqr->lpm = device->path_data.opm;
1455                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1456                                       "start_IO: selected paths gone,"
1457                                       " retry on all paths");
1458                 } else {
1459                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1460                                       "start_IO: all paths in opm gone,"
1461                                       " do path verification");
1462                         dasd_generic_last_path_gone(device);
1463                         device->path_data.opm = 0;
1464                         device->path_data.ppm = 0;
1465                         device->path_data.npm = 0;
1466                         device->path_data.tbvpm =
1467                                 ccw_device_get_path_mask(device->cdev);
1468                 }
1469                 break;
1470         case -ENODEV:
1471                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1472                               "start_IO: -ENODEV device gone, retry");
1473                 break;
1474         case -EIO:
1475                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1476                               "start_IO: -EIO device gone, retry");
1477                 break;
1478         case -EINVAL:
1479                 /* most likely caused in power management context */
1480                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1481                               "start_IO: -EINVAL device currently "
1482                               "not accessible");
1483                 break;
1484         default:
1485                 /* internal error 11 - unknown rc */
1486                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1487                 dev_err(&device->cdev->dev,
1488                         "An error occurred in the DASD device driver, "
1489                         "reason=%s\n", errorstring);
1490                 BUG();
1491                 break;
1492         }
1493         cqr->intrc = rc;
1494         return rc;
1495 }
1496
1497 /*
1498  * Timeout function for dasd devices. This is used for different purposes
1499  *  1) missing interrupt handler for normal operation
1500  *  2) delayed start of request where start_IO failed with -EBUSY
1501  *  3) timeout for missing state change interrupts
1502  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1503  * DASD_CQR_QUEUED for 2) and 3).
1504  */
1505 static void dasd_device_timeout(unsigned long ptr)
1506 {
1507         unsigned long flags;
1508         struct dasd_device *device;
1509
1510         device = (struct dasd_device *) ptr;
1511         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1512         /* re-activate request queue */
1513         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1514         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1515         dasd_schedule_device_bh(device);
1516 }
1517
1518 /*
1519  * Setup timeout for a device in jiffies.
1520  */
1521 void dasd_device_set_timer(struct dasd_device *device, int expires)
1522 {
1523         if (expires == 0)
1524                 del_timer(&device->timer);
1525         else
1526                 mod_timer(&device->timer, jiffies + expires);
1527 }
1528
1529 /*
1530  * Clear timeout for a device.
1531  */
1532 void dasd_device_clear_timer(struct dasd_device *device)
1533 {
1534         del_timer(&device->timer);
1535 }
1536
1537 static void dasd_handle_killed_request(struct ccw_device *cdev,
1538                                        unsigned long intparm)
1539 {
1540         struct dasd_ccw_req *cqr;
1541         struct dasd_device *device;
1542
1543         if (!intparm)
1544                 return;
1545         cqr = (struct dasd_ccw_req *) intparm;
1546         if (cqr->status != DASD_CQR_IN_IO) {
1547                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1548                                 "invalid status in handle_killed_request: "
1549                                 "%02x", cqr->status);
1550                 return;
1551         }
1552
1553         device = dasd_device_from_cdev_locked(cdev);
1554         if (IS_ERR(device)) {
1555                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1556                                 "unable to get device from cdev");
1557                 return;
1558         }
1559
1560         if (!cqr->startdev ||
1561             device != cqr->startdev ||
1562             strncmp(cqr->startdev->discipline->ebcname,
1563                     (char *) &cqr->magic, 4)) {
1564                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1565                                 "invalid device in request");
1566                 dasd_put_device(device);
1567                 return;
1568         }
1569
1570         /* Schedule request to be retried. */
1571         cqr->status = DASD_CQR_QUEUED;
1572
1573         dasd_device_clear_timer(device);
1574         dasd_schedule_device_bh(device);
1575         dasd_put_device(device);
1576 }
1577
1578 void dasd_generic_handle_state_change(struct dasd_device *device)
1579 {
1580         /* First of all start sense subsystem status request. */
1581         dasd_eer_snss(device);
1582
1583         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1584         dasd_schedule_device_bh(device);
1585         if (device->block)
1586                 dasd_schedule_block_bh(device->block);
1587 }
1588
1589 /*
1590  * Interrupt handler for "normal" ssch-io based dasd devices.
1591  */
1592 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1593                       struct irb *irb)
1594 {
1595         struct dasd_ccw_req *cqr, *next;
1596         struct dasd_device *device;
1597         unsigned long long now;
1598         int expires;
1599
1600         if (IS_ERR(irb)) {
1601                 switch (PTR_ERR(irb)) {
1602                 case -EIO:
1603                         break;
1604                 case -ETIMEDOUT:
1605                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1606                                         "request timed out\n", __func__);
1607                         break;
1608                 default:
1609                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1610                                         "unknown error %ld\n", __func__,
1611                                         PTR_ERR(irb));
1612                 }
1613                 dasd_handle_killed_request(cdev, intparm);
1614                 return;
1615         }
1616
1617         now = get_clock();
1618         cqr = (struct dasd_ccw_req *) intparm;
1619         /* check for conditions that should be handled immediately */
1620         if (!cqr ||
1621             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1622               scsw_cstat(&irb->scsw) == 0)) {
1623                 if (cqr)
1624                         memcpy(&cqr->irb, irb, sizeof(*irb));
1625                 device = dasd_device_from_cdev_locked(cdev);
1626                 if (IS_ERR(device))
1627                         return;
1628                 /* ignore unsolicited interrupts for DIAG discipline */
1629                 if (device->discipline == dasd_diag_discipline_pointer) {
1630                         dasd_put_device(device);
1631                         return;
1632                 }
1633                 device->discipline->dump_sense_dbf(device, irb, "int");
1634                 if (device->features & DASD_FEATURE_ERPLOG)
1635                         device->discipline->dump_sense(device, cqr, irb);
1636                 device->discipline->check_for_device_change(device, cqr, irb);
1637                 dasd_put_device(device);
1638         }
1639         if (!cqr)
1640                 return;
1641
1642         device = (struct dasd_device *) cqr->startdev;
1643         if (!device ||
1644             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1645                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1646                                 "invalid device in request");
1647                 return;
1648         }
1649
1650         /* Check for clear pending */
1651         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1652             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1653                 cqr->status = DASD_CQR_CLEARED;
1654                 dasd_device_clear_timer(device);
1655                 wake_up(&dasd_flush_wq);
1656                 dasd_schedule_device_bh(device);
1657                 return;
1658         }
1659
1660         /* check status - the request might have been killed by dyn detach */
1661         if (cqr->status != DASD_CQR_IN_IO) {
1662                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1663                               "status %02x", dev_name(&cdev->dev), cqr->status);
1664                 return;
1665         }
1666
1667         next = NULL;
1668         expires = 0;
1669         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1670             scsw_cstat(&irb->scsw) == 0) {
1671                 /* request was completed successfully */
1672                 cqr->status = DASD_CQR_SUCCESS;
1673                 cqr->stopclk = now;
1674                 /* Start first request on queue if possible -> fast_io. */
1675                 if (cqr->devlist.next != &device->ccw_queue) {
1676                         next = list_entry(cqr->devlist.next,
1677                                           struct dasd_ccw_req, devlist);
1678                 }
1679         } else {  /* error */
1680                 /*
1681                  * If we don't want complex ERP for this request, then just
1682                  * reset this and retry it in the fastpath
1683                  */
1684                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1685                     cqr->retries > 0) {
1686                         if (cqr->lpm == device->path_data.opm)
1687                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1688                                               "default ERP in fastpath "
1689                                               "(%i retries left)",
1690                                               cqr->retries);
1691                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1692                                 cqr->lpm = device->path_data.opm;
1693                         cqr->status = DASD_CQR_QUEUED;
1694                         next = cqr;
1695                 } else
1696                         cqr->status = DASD_CQR_ERROR;
1697         }
1698         if (next && (next->status == DASD_CQR_QUEUED) &&
1699             (!device->stopped)) {
1700                 if (device->discipline->start_IO(next) == 0)
1701                         expires = next->expires;
1702         }
1703         if (expires != 0)
1704                 dasd_device_set_timer(device, expires);
1705         else
1706                 dasd_device_clear_timer(device);
1707         dasd_schedule_device_bh(device);
1708 }
1709
1710 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1711 {
1712         struct dasd_device *device;
1713
1714         device = dasd_device_from_cdev_locked(cdev);
1715
1716         if (IS_ERR(device))
1717                 goto out;
1718         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1719            device->state != device->target ||
1720            !device->discipline->check_for_device_change){
1721                 dasd_put_device(device);
1722                 goto out;
1723         }
1724         if (device->discipline->dump_sense_dbf)
1725                 device->discipline->dump_sense_dbf(device, irb, "uc");
1726         device->discipline->check_for_device_change(device, NULL, irb);
1727         dasd_put_device(device);
1728 out:
1729         return UC_TODO_RETRY;
1730 }
1731 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1732
1733 /*
1734  * If we have an error on a dasd_block layer request then we cancel
1735  * and return all further requests from the same dasd_block as well.
1736  */
1737 static void __dasd_device_recovery(struct dasd_device *device,
1738                                    struct dasd_ccw_req *ref_cqr)
1739 {
1740         struct list_head *l, *n;
1741         struct dasd_ccw_req *cqr;
1742
1743         /*
1744          * only requeue request that came from the dasd_block layer
1745          */
1746         if (!ref_cqr->block)
1747                 return;
1748
1749         list_for_each_safe(l, n, &device->ccw_queue) {
1750                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1751                 if (cqr->status == DASD_CQR_QUEUED &&
1752                     ref_cqr->block == cqr->block) {
1753                         cqr->status = DASD_CQR_CLEARED;
1754                 }
1755         }
1756 };
1757
1758 /*
1759  * Remove those ccw requests from the queue that need to be returned
1760  * to the upper layer.
1761  */
1762 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1763                                             struct list_head *final_queue)
1764 {
1765         struct list_head *l, *n;
1766         struct dasd_ccw_req *cqr;
1767
1768         /* Process request with final status. */
1769         list_for_each_safe(l, n, &device->ccw_queue) {
1770                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1771
1772                 /* Stop list processing at the first non-final request. */
1773                 if (cqr->status == DASD_CQR_QUEUED ||
1774                     cqr->status == DASD_CQR_IN_IO ||
1775                     cqr->status == DASD_CQR_CLEAR_PENDING)
1776                         break;
1777                 if (cqr->status == DASD_CQR_ERROR) {
1778                         __dasd_device_recovery(device, cqr);
1779                 }
1780                 /* Rechain finished requests to final queue */
1781                 list_move_tail(&cqr->devlist, final_queue);
1782         }
1783 }
1784
1785 /*
1786  * the cqrs from the final queue are returned to the upper layer
1787  * by setting a dasd_block state and calling the callback function
1788  */
1789 static void __dasd_device_process_final_queue(struct dasd_device *device,
1790                                               struct list_head *final_queue)
1791 {
1792         struct list_head *l, *n;
1793         struct dasd_ccw_req *cqr;
1794         struct dasd_block *block;
1795         void (*callback)(struct dasd_ccw_req *, void *data);
1796         void *callback_data;
1797         char errorstring[ERRORLENGTH];
1798
1799         list_for_each_safe(l, n, final_queue) {
1800                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1801                 list_del_init(&cqr->devlist);
1802                 block = cqr->block;
1803                 callback = cqr->callback;
1804                 callback_data = cqr->callback_data;
1805                 if (block)
1806                         spin_lock_bh(&block->queue_lock);
1807                 switch (cqr->status) {
1808                 case DASD_CQR_SUCCESS:
1809                         cqr->status = DASD_CQR_DONE;
1810                         break;
1811                 case DASD_CQR_ERROR:
1812                         cqr->status = DASD_CQR_NEED_ERP;
1813                         break;
1814                 case DASD_CQR_CLEARED:
1815                         cqr->status = DASD_CQR_TERMINATED;
1816                         break;
1817                 default:
1818                         /* internal error 12 - wrong cqr status*/
1819                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1820                         dev_err(&device->cdev->dev,
1821                                 "An error occurred in the DASD device driver, "
1822                                 "reason=%s\n", errorstring);
1823                         BUG();
1824                 }
1825                 if (cqr->callback != NULL)
1826                         (callback)(cqr, callback_data);
1827                 if (block)
1828                         spin_unlock_bh(&block->queue_lock);
1829         }
1830 }
1831
1832 /*
1833  * Take a look at the first request on the ccw queue and check
1834  * if it reached its expire time. If so, terminate the IO.
1835  */
1836 static void __dasd_device_check_expire(struct dasd_device *device)
1837 {
1838         struct dasd_ccw_req *cqr;
1839
1840         if (list_empty(&device->ccw_queue))
1841                 return;
1842         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1843         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1844             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1845                 if (device->discipline->term_IO(cqr) != 0) {
1846                         /* Hmpf, try again in 5 sec */
1847                         dev_err(&device->cdev->dev,
1848                                 "cqr %p timed out (%lus) but cannot be "
1849                                 "ended, retrying in 5 s\n",
1850                                 cqr, (cqr->expires/HZ));
1851                         cqr->expires += 5*HZ;
1852                         dasd_device_set_timer(device, 5*HZ);
1853                 } else {
1854                         dev_err(&device->cdev->dev,
1855                                 "cqr %p timed out (%lus), %i retries "
1856                                 "remaining\n", cqr, (cqr->expires/HZ),
1857                                 cqr->retries);
1858                 }
1859         }
1860 }
1861
1862 /*
1863  * Take a look at the first request on the ccw queue and check
1864  * if it needs to be started.
1865  */
1866 static void __dasd_device_start_head(struct dasd_device *device)
1867 {
1868         struct dasd_ccw_req *cqr;
1869         int rc;
1870
1871         if (list_empty(&device->ccw_queue))
1872                 return;
1873         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1874         if (cqr->status != DASD_CQR_QUEUED)
1875                 return;
1876         /* when device is stopped, return request to previous layer
1877          * exception: only the disconnect or unresumed bits are set and the
1878          * cqr is a path verification request
1879          */
1880         if (device->stopped &&
1881             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1882               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1883                 cqr->intrc = -EAGAIN;
1884                 cqr->status = DASD_CQR_CLEARED;
1885                 dasd_schedule_device_bh(device);
1886                 return;
1887         }
1888
1889         rc = device->discipline->start_IO(cqr);
1890         if (rc == 0)
1891                 dasd_device_set_timer(device, cqr->expires);
1892         else if (rc == -EACCES) {
1893                 dasd_schedule_device_bh(device);
1894         } else
1895                 /* Hmpf, try again in 1/2 sec */
1896                 dasd_device_set_timer(device, 50);
1897 }
1898
1899 static void __dasd_device_check_path_events(struct dasd_device *device)
1900 {
1901         int rc;
1902
1903         if (device->path_data.tbvpm) {
1904                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1905                                         DASD_UNRESUMED_PM))
1906                         return;
1907                 rc = device->discipline->verify_path(
1908                         device, device->path_data.tbvpm);
1909                 if (rc)
1910                         dasd_device_set_timer(device, 50);
1911                 else
1912                         device->path_data.tbvpm = 0;
1913         }
1914 };
1915
1916 /*
1917  * Go through all request on the dasd_device request queue,
1918  * terminate them on the cdev if necessary, and return them to the
1919  * submitting layer via callback.
1920  * Note:
1921  * Make sure that all 'submitting layers' still exist when
1922  * this function is called!. In other words, when 'device' is a base
1923  * device then all block layer requests must have been removed before
1924  * via dasd_flush_block_queue.
1925  */
1926 int dasd_flush_device_queue(struct dasd_device *device)
1927 {
1928         struct dasd_ccw_req *cqr, *n;
1929         int rc;
1930         struct list_head flush_queue;
1931
1932         INIT_LIST_HEAD(&flush_queue);
1933         spin_lock_irq(get_ccwdev_lock(device->cdev));
1934         rc = 0;
1935         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1936                 /* Check status and move request to flush_queue */
1937                 switch (cqr->status) {
1938                 case DASD_CQR_IN_IO:
1939                         rc = device->discipline->term_IO(cqr);
1940                         if (rc) {
1941                                 /* unable to terminate requeust */
1942                                 dev_err(&device->cdev->dev,
1943                                         "Flushing the DASD request queue "
1944                                         "failed for request %p\n", cqr);
1945                                 /* stop flush processing */
1946                                 goto finished;
1947                         }
1948                         break;
1949                 case DASD_CQR_QUEUED:
1950                         cqr->stopclk = get_clock();
1951                         cqr->status = DASD_CQR_CLEARED;
1952                         break;
1953                 default: /* no need to modify the others */
1954                         break;
1955                 }
1956                 list_move_tail(&cqr->devlist, &flush_queue);
1957         }
1958 finished:
1959         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1960         /*
1961          * After this point all requests must be in state CLEAR_PENDING,
1962          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1963          * one of the others.
1964          */
1965         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1966                 wait_event(dasd_flush_wq,
1967                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1968         /*
1969          * Now set each request back to TERMINATED, DONE or NEED_ERP
1970          * and call the callback function of flushed requests
1971          */
1972         __dasd_device_process_final_queue(device, &flush_queue);
1973         return rc;
1974 }
1975
1976 /*
1977  * Acquire the device lock and process queues for the device.
1978  */
1979 static void dasd_device_tasklet(struct dasd_device *device)
1980 {
1981         struct list_head final_queue;
1982
1983         atomic_set (&device->tasklet_scheduled, 0);
1984         INIT_LIST_HEAD(&final_queue);
1985         spin_lock_irq(get_ccwdev_lock(device->cdev));
1986         /* Check expire time of first request on the ccw queue. */
1987         __dasd_device_check_expire(device);
1988         /* find final requests on ccw queue */
1989         __dasd_device_process_ccw_queue(device, &final_queue);
1990         __dasd_device_check_path_events(device);
1991         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1992         /* Now call the callback function of requests with final status */
1993         __dasd_device_process_final_queue(device, &final_queue);
1994         spin_lock_irq(get_ccwdev_lock(device->cdev));
1995         /* Now check if the head of the ccw queue needs to be started. */
1996         __dasd_device_start_head(device);
1997         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1998         if (waitqueue_active(&shutdown_waitq))
1999                 wake_up(&shutdown_waitq);
2000         dasd_put_device(device);
2001 }
2002
2003 /*
2004  * Schedules a call to dasd_tasklet over the device tasklet.
2005  */
2006 void dasd_schedule_device_bh(struct dasd_device *device)
2007 {
2008         /* Protect against rescheduling. */
2009         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2010                 return;
2011         dasd_get_device(device);
2012         tasklet_hi_schedule(&device->tasklet);
2013 }
2014
2015 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2016 {
2017         device->stopped |= bits;
2018 }
2019 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2020
2021 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2022 {
2023         device->stopped &= ~bits;
2024         if (!device->stopped)
2025                 wake_up(&generic_waitq);
2026 }
2027 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2028
2029 /*
2030  * Queue a request to the head of the device ccw_queue.
2031  * Start the I/O if possible.
2032  */
2033 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2034 {
2035         struct dasd_device *device;
2036         unsigned long flags;
2037
2038         device = cqr->startdev;
2039         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2040         cqr->status = DASD_CQR_QUEUED;
2041         list_add(&cqr->devlist, &device->ccw_queue);
2042         /* let the bh start the request to keep them in order */
2043         dasd_schedule_device_bh(device);
2044         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2045 }
2046
2047 /*
2048  * Queue a request to the tail of the device ccw_queue.
2049  * Start the I/O if possible.
2050  */
2051 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2052 {
2053         struct dasd_device *device;
2054         unsigned long flags;
2055
2056         device = cqr->startdev;
2057         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2058         cqr->status = DASD_CQR_QUEUED;
2059         list_add_tail(&cqr->devlist, &device->ccw_queue);
2060         /* let the bh start the request to keep them in order */
2061         dasd_schedule_device_bh(device);
2062         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2063 }
2064
2065 /*
2066  * Wakeup helper for the 'sleep_on' functions.
2067  */
2068 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2069 {
2070         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2071         cqr->callback_data = DASD_SLEEPON_END_TAG;
2072         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2073         wake_up(&generic_waitq);
2074 }
2075 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2076
2077 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2078 {
2079         struct dasd_device *device;
2080         int rc;
2081
2082         device = cqr->startdev;
2083         spin_lock_irq(get_ccwdev_lock(device->cdev));
2084         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2085         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2086         return rc;
2087 }
2088
2089 /*
2090  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2091  */
2092 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2093 {
2094         struct dasd_device *device;
2095         dasd_erp_fn_t erp_fn;
2096
2097         if (cqr->status == DASD_CQR_FILLED)
2098                 return 0;
2099         device = cqr->startdev;
2100         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2101                 if (cqr->status == DASD_CQR_TERMINATED) {
2102                         device->discipline->handle_terminated_request(cqr);
2103                         return 1;
2104                 }
2105                 if (cqr->status == DASD_CQR_NEED_ERP) {
2106                         erp_fn = device->discipline->erp_action(cqr);
2107                         erp_fn(cqr);
2108                         return 1;
2109                 }
2110                 if (cqr->status == DASD_CQR_FAILED)
2111                         dasd_log_sense(cqr, &cqr->irb);
2112                 if (cqr->refers) {
2113                         __dasd_process_erp(device, cqr);
2114                         return 1;
2115                 }
2116         }
2117         return 0;
2118 }
2119
2120 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2121 {
2122         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2123                 if (cqr->refers) /* erp is not done yet */
2124                         return 1;
2125                 return ((cqr->status != DASD_CQR_DONE) &&
2126                         (cqr->status != DASD_CQR_FAILED));
2127         } else
2128                 return (cqr->status == DASD_CQR_FILLED);
2129 }
2130
2131 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2132 {
2133         struct dasd_device *device;
2134         int rc;
2135         struct list_head ccw_queue;
2136         struct dasd_ccw_req *cqr;
2137
2138         INIT_LIST_HEAD(&ccw_queue);
2139         maincqr->status = DASD_CQR_FILLED;
2140         device = maincqr->startdev;
2141         list_add(&maincqr->blocklist, &ccw_queue);
2142         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2143              cqr = list_first_entry(&ccw_queue,
2144                                     struct dasd_ccw_req, blocklist)) {
2145
2146                 if (__dasd_sleep_on_erp(cqr))
2147                         continue;
2148                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2149                         continue;
2150                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2151                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2152                         cqr->status = DASD_CQR_FAILED;
2153                         cqr->intrc = -EPERM;
2154                         continue;
2155                 }
2156                 /* Non-temporary stop condition will trigger fail fast */
2157                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2158                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2159                     (!dasd_eer_enabled(device))) {
2160                         cqr->status = DASD_CQR_FAILED;
2161                         continue;
2162                 }
2163                 /* Don't try to start requests if device is stopped */
2164                 if (interruptible) {
2165                         rc = wait_event_interruptible(
2166                                 generic_waitq, !(device->stopped));
2167                         if (rc == -ERESTARTSYS) {
2168                                 cqr->status = DASD_CQR_FAILED;
2169                                 maincqr->intrc = rc;
2170                                 continue;
2171                         }
2172                 } else
2173                         wait_event(generic_waitq, !(device->stopped));
2174
2175                 if (!cqr->callback)
2176                         cqr->callback = dasd_wakeup_cb;
2177
2178                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2179                 dasd_add_request_tail(cqr);
2180                 if (interruptible) {
2181                         rc = wait_event_interruptible(
2182                                 generic_waitq, _wait_for_wakeup(cqr));
2183                         if (rc == -ERESTARTSYS) {
2184                                 dasd_cancel_req(cqr);
2185                                 /* wait (non-interruptible) for final status */
2186                                 wait_event(generic_waitq,
2187                                            _wait_for_wakeup(cqr));
2188                                 cqr->status = DASD_CQR_FAILED;
2189                                 maincqr->intrc = rc;
2190                                 continue;
2191                         }
2192                 } else
2193                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2194         }
2195
2196         maincqr->endclk = get_clock();
2197         if ((maincqr->status != DASD_CQR_DONE) &&
2198             (maincqr->intrc != -ERESTARTSYS))
2199                 dasd_log_sense(maincqr, &maincqr->irb);
2200         if (maincqr->status == DASD_CQR_DONE)
2201                 rc = 0;
2202         else if (maincqr->intrc)
2203                 rc = maincqr->intrc;
2204         else
2205                 rc = -EIO;
2206         return rc;
2207 }
2208
2209 /*
2210  * Queue a request to the tail of the device ccw_queue and wait for
2211  * it's completion.
2212  */
2213 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2214 {
2215         return _dasd_sleep_on(cqr, 0);
2216 }
2217
2218 /*
2219  * Queue a request to the tail of the device ccw_queue and wait
2220  * interruptible for it's completion.
2221  */
2222 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2223 {
2224         return _dasd_sleep_on(cqr, 1);
2225 }
2226
2227 /*
2228  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2229  * for eckd devices) the currently running request has to be terminated
2230  * and be put back to status queued, before the special request is added
2231  * to the head of the queue. Then the special request is waited on normally.
2232  */
2233 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2234 {
2235         struct dasd_ccw_req *cqr;
2236         int rc;
2237
2238         if (list_empty(&device->ccw_queue))
2239                 return 0;
2240         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2241         rc = device->discipline->term_IO(cqr);
2242         if (!rc)
2243                 /*
2244                  * CQR terminated because a more important request is pending.
2245                  * Undo decreasing of retry counter because this is
2246                  * not an error case.
2247                  */
2248                 cqr->retries++;
2249         return rc;
2250 }
2251
2252 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2253 {
2254         struct dasd_device *device;
2255         int rc;
2256
2257         device = cqr->startdev;
2258         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2259             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2260                 cqr->status = DASD_CQR_FAILED;
2261                 cqr->intrc = -EPERM;
2262                 return -EIO;
2263         }
2264         spin_lock_irq(get_ccwdev_lock(device->cdev));
2265         rc = _dasd_term_running_cqr(device);
2266         if (rc) {
2267                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2268                 return rc;
2269         }
2270         cqr->callback = dasd_wakeup_cb;
2271         cqr->callback_data = DASD_SLEEPON_START_TAG;
2272         cqr->status = DASD_CQR_QUEUED;
2273         /*
2274          * add new request as second
2275          * first the terminated cqr needs to be finished
2276          */
2277         list_add(&cqr->devlist, device->ccw_queue.next);
2278
2279         /* let the bh start the request to keep them in order */
2280         dasd_schedule_device_bh(device);
2281
2282         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2283
2284         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2285
2286         if (cqr->status == DASD_CQR_DONE)
2287                 rc = 0;
2288         else if (cqr->intrc)
2289                 rc = cqr->intrc;
2290         else
2291                 rc = -EIO;
2292         return rc;
2293 }
2294
2295 /*
2296  * Cancels a request that was started with dasd_sleep_on_req.
2297  * This is useful to timeout requests. The request will be
2298  * terminated if it is currently in i/o.
2299  * Returns 1 if the request has been terminated.
2300  *         0 if there was no need to terminate the request (not started yet)
2301  *         negative error code if termination failed
2302  * Cancellation of a request is an asynchronous operation! The calling
2303  * function has to wait until the request is properly returned via callback.
2304  */
2305 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2306 {
2307         struct dasd_device *device = cqr->startdev;
2308         unsigned long flags;
2309         int rc;
2310
2311         rc = 0;
2312         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2313         switch (cqr->status) {
2314         case DASD_CQR_QUEUED:
2315                 /* request was not started - just set to cleared */
2316                 cqr->status = DASD_CQR_CLEARED;
2317                 break;
2318         case DASD_CQR_IN_IO:
2319                 /* request in IO - terminate IO and release again */
2320                 rc = device->discipline->term_IO(cqr);
2321                 if (rc) {
2322                         dev_err(&device->cdev->dev,
2323                                 "Cancelling request %p failed with rc=%d\n",
2324                                 cqr, rc);
2325                 } else {
2326                         cqr->stopclk = get_clock();
2327                 }
2328                 break;
2329         default: /* already finished or clear pending - do nothing */
2330                 break;
2331         }
2332         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2333         dasd_schedule_device_bh(device);
2334         return rc;
2335 }
2336
2337
2338 /*
2339  * SECTION: Operations of the dasd_block layer.
2340  */
2341
2342 /*
2343  * Timeout function for dasd_block. This is used when the block layer
2344  * is waiting for something that may not come reliably, (e.g. a state
2345  * change interrupt)
2346  */
2347 static void dasd_block_timeout(unsigned long ptr)
2348 {
2349         unsigned long flags;
2350         struct dasd_block *block;
2351
2352         block = (struct dasd_block *) ptr;
2353         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2354         /* re-activate request queue */
2355         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2356         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2357         dasd_schedule_block_bh(block);
2358 }
2359
2360 /*
2361  * Setup timeout for a dasd_block in jiffies.
2362  */
2363 void dasd_block_set_timer(struct dasd_block *block, int expires)
2364 {
2365         if (expires == 0)
2366                 del_timer(&block->timer);
2367         else
2368                 mod_timer(&block->timer, jiffies + expires);
2369 }
2370
2371 /*
2372  * Clear timeout for a dasd_block.
2373  */
2374 void dasd_block_clear_timer(struct dasd_block *block)
2375 {
2376         del_timer(&block->timer);
2377 }
2378
2379 /*
2380  * Process finished error recovery ccw.
2381  */
2382 static void __dasd_process_erp(struct dasd_device *device,
2383                                struct dasd_ccw_req *cqr)
2384 {
2385         dasd_erp_fn_t erp_fn;
2386
2387         if (cqr->status == DASD_CQR_DONE)
2388                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2389         else
2390                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2391         erp_fn = device->discipline->erp_postaction(cqr);
2392         erp_fn(cqr);
2393 }
2394
2395 /*
2396  * Fetch requests from the block device queue.
2397  */
2398 static void __dasd_process_request_queue(struct dasd_block *block)
2399 {
2400         struct request_queue *queue;
2401         struct request *req;
2402         struct dasd_ccw_req *cqr;
2403         struct dasd_device *basedev;
2404         unsigned long flags;
2405         queue = block->request_queue;
2406         basedev = block->base;
2407         /* No queue ? Then there is nothing to do. */
2408         if (queue == NULL)
2409                 return;
2410
2411         /*
2412          * We requeue request from the block device queue to the ccw
2413          * queue only in two states. In state DASD_STATE_READY the
2414          * partition detection is done and we need to requeue requests
2415          * for that. State DASD_STATE_ONLINE is normal block device
2416          * operation.
2417          */
2418         if (basedev->state < DASD_STATE_READY) {
2419                 while ((req = blk_fetch_request(block->request_queue)))
2420                         __blk_end_request_all(req, -EIO);
2421                 return;
2422         }
2423         /* Now we try to fetch requests from the request queue */
2424         while ((req = blk_peek_request(queue))) {
2425                 if (basedev->features & DASD_FEATURE_READONLY &&
2426                     rq_data_dir(req) == WRITE) {
2427                         DBF_DEV_EVENT(DBF_ERR, basedev,
2428                                       "Rejecting write request %p",
2429                                       req);
2430                         blk_start_request(req);
2431                         __blk_end_request_all(req, -EIO);
2432                         continue;
2433                 }
2434                 cqr = basedev->discipline->build_cp(basedev, block, req);
2435                 if (IS_ERR(cqr)) {
2436                         if (PTR_ERR(cqr) == -EBUSY)
2437                                 break;  /* normal end condition */
2438                         if (PTR_ERR(cqr) == -ENOMEM)
2439                                 break;  /* terminate request queue loop */
2440                         if (PTR_ERR(cqr) == -EAGAIN) {
2441                                 /*
2442                                  * The current request cannot be build right
2443                                  * now, we have to try later. If this request
2444                                  * is the head-of-queue we stop the device
2445                                  * for 1/2 second.
2446                                  */
2447                                 if (!list_empty(&block->ccw_queue))
2448                                         break;
2449                                 spin_lock_irqsave(
2450                                         get_ccwdev_lock(basedev->cdev), flags);
2451                                 dasd_device_set_stop_bits(basedev,
2452                                                           DASD_STOPPED_PENDING);
2453                                 spin_unlock_irqrestore(
2454                                         get_ccwdev_lock(basedev->cdev), flags);
2455                                 dasd_block_set_timer(block, HZ/2);
2456                                 break;
2457                         }
2458                         DBF_DEV_EVENT(DBF_ERR, basedev,
2459                                       "CCW creation failed (rc=%ld) "
2460                                       "on request %p",
2461                                       PTR_ERR(cqr), req);
2462                         blk_start_request(req);
2463                         __blk_end_request_all(req, -EIO);
2464                         continue;
2465                 }
2466                 /*
2467                  *  Note: callback is set to dasd_return_cqr_cb in
2468                  * __dasd_block_start_head to cover erp requests as well
2469                  */
2470                 cqr->callback_data = (void *) req;
2471                 cqr->status = DASD_CQR_FILLED;
2472                 blk_start_request(req);
2473                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2474                 dasd_profile_start(block, cqr, req);
2475         }
2476 }
2477
2478 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2479 {
2480         struct request *req;
2481         int status;
2482         int error = 0;
2483
2484         req = (struct request *) cqr->callback_data;
2485         dasd_profile_end(cqr->block, cqr, req);
2486         status = cqr->block->base->discipline->free_cp(cqr, req);
2487         if (status <= 0)
2488                 error = status ? status : -EIO;
2489         __blk_end_request_all(req, error);
2490 }
2491
2492 /*
2493  * Process ccw request queue.
2494  */
2495 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2496                                            struct list_head *final_queue)
2497 {
2498         struct list_head *l, *n;
2499         struct dasd_ccw_req *cqr;
2500         dasd_erp_fn_t erp_fn;
2501         unsigned long flags;
2502         struct dasd_device *base = block->base;
2503
2504 restart:
2505         /* Process request with final status. */
2506         list_for_each_safe(l, n, &block->ccw_queue) {
2507                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2508                 if (cqr->status != DASD_CQR_DONE &&
2509                     cqr->status != DASD_CQR_FAILED &&
2510                     cqr->status != DASD_CQR_NEED_ERP &&
2511                     cqr->status != DASD_CQR_TERMINATED)
2512                         continue;
2513
2514                 if (cqr->status == DASD_CQR_TERMINATED) {
2515                         base->discipline->handle_terminated_request(cqr);
2516                         goto restart;
2517                 }
2518
2519                 /*  Process requests that may be recovered */
2520                 if (cqr->status == DASD_CQR_NEED_ERP) {
2521                         erp_fn = base->discipline->erp_action(cqr);
2522                         if (IS_ERR(erp_fn(cqr)))
2523                                 continue;
2524                         goto restart;
2525                 }
2526
2527                 /* log sense for fatal error */
2528                 if (cqr->status == DASD_CQR_FAILED) {
2529                         dasd_log_sense(cqr, &cqr->irb);
2530                 }
2531
2532                 /* First of all call extended error reporting. */
2533                 if (dasd_eer_enabled(base) &&
2534                     cqr->status == DASD_CQR_FAILED) {
2535                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2536
2537                         /* restart request  */
2538                         cqr->status = DASD_CQR_FILLED;
2539                         cqr->retries = 255;
2540                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2541                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2542                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2543                                                flags);
2544                         goto restart;
2545                 }
2546
2547                 /* Process finished ERP request. */
2548                 if (cqr->refers) {
2549                         __dasd_process_erp(base, cqr);
2550                         goto restart;
2551                 }
2552
2553                 /* Rechain finished requests to final queue */
2554                 cqr->endclk = get_clock();
2555                 list_move_tail(&cqr->blocklist, final_queue);
2556         }
2557 }
2558
2559 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2560 {
2561         dasd_schedule_block_bh(cqr->block);
2562 }
2563
2564 static void __dasd_block_start_head(struct dasd_block *block)
2565 {
2566         struct dasd_ccw_req *cqr;
2567
2568         if (list_empty(&block->ccw_queue))
2569                 return;
2570         /* We allways begin with the first requests on the queue, as some
2571          * of previously started requests have to be enqueued on a
2572          * dasd_device again for error recovery.
2573          */
2574         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2575                 if (cqr->status != DASD_CQR_FILLED)
2576                         continue;
2577                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2578                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2579                         cqr->status = DASD_CQR_FAILED;
2580                         cqr->intrc = -EPERM;
2581                         dasd_schedule_block_bh(block);
2582                         continue;
2583                 }
2584                 /* Non-temporary stop condition will trigger fail fast */
2585                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2586                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2587                     (!dasd_eer_enabled(block->base))) {
2588                         cqr->status = DASD_CQR_FAILED;
2589                         dasd_schedule_block_bh(block);
2590                         continue;
2591                 }
2592                 /* Don't try to start requests if device is stopped */
2593                 if (block->base->stopped)
2594                         return;
2595
2596                 /* just a fail safe check, should not happen */
2597                 if (!cqr->startdev)
2598                         cqr->startdev = block->base;
2599
2600                 /* make sure that the requests we submit find their way back */
2601                 cqr->callback = dasd_return_cqr_cb;
2602
2603                 dasd_add_request_tail(cqr);
2604         }
2605 }
2606
2607 /*
2608  * Central dasd_block layer routine. Takes requests from the generic
2609  * block layer request queue, creates ccw requests, enqueues them on
2610  * a dasd_device and processes ccw requests that have been returned.
2611  */
2612 static void dasd_block_tasklet(struct dasd_block *block)
2613 {
2614         struct list_head final_queue;
2615         struct list_head *l, *n;
2616         struct dasd_ccw_req *cqr;
2617
2618         atomic_set(&block->tasklet_scheduled, 0);
2619         INIT_LIST_HEAD(&final_queue);
2620         spin_lock(&block->queue_lock);
2621         /* Finish off requests on ccw queue */
2622         __dasd_process_block_ccw_queue(block, &final_queue);
2623         spin_unlock(&block->queue_lock);
2624         /* Now call the callback function of requests with final status */
2625         spin_lock_irq(&block->request_queue_lock);
2626         list_for_each_safe(l, n, &final_queue) {
2627                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2628                 list_del_init(&cqr->blocklist);
2629                 __dasd_cleanup_cqr(cqr);
2630         }
2631         spin_lock(&block->queue_lock);
2632         /* Get new request from the block device request queue */
2633         __dasd_process_request_queue(block);
2634         /* Now check if the head of the ccw queue needs to be started. */
2635         __dasd_block_start_head(block);
2636         spin_unlock(&block->queue_lock);
2637         spin_unlock_irq(&block->request_queue_lock);
2638         if (waitqueue_active(&shutdown_waitq))
2639                 wake_up(&shutdown_waitq);
2640         dasd_put_device(block->base);
2641 }
2642
2643 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2644 {
2645         wake_up(&dasd_flush_wq);
2646 }
2647
2648 /*
2649  * Go through all request on the dasd_block request queue, cancel them
2650  * on the respective dasd_device, and return them to the generic
2651  * block layer.
2652  */
2653 static int dasd_flush_block_queue(struct dasd_block *block)
2654 {
2655         struct dasd_ccw_req *cqr, *n;
2656         int rc, i;
2657         struct list_head flush_queue;
2658
2659         INIT_LIST_HEAD(&flush_queue);
2660         spin_lock_bh(&block->queue_lock);
2661         rc = 0;
2662 restart:
2663         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2664                 /* if this request currently owned by a dasd_device cancel it */
2665                 if (cqr->status >= DASD_CQR_QUEUED)
2666                         rc = dasd_cancel_req(cqr);
2667                 if (rc < 0)
2668                         break;
2669                 /* Rechain request (including erp chain) so it won't be
2670                  * touched by the dasd_block_tasklet anymore.
2671                  * Replace the callback so we notice when the request
2672                  * is returned from the dasd_device layer.
2673                  */
2674                 cqr->callback = _dasd_wake_block_flush_cb;
2675                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2676                         list_move_tail(&cqr->blocklist, &flush_queue);
2677                 if (i > 1)
2678                         /* moved more than one request - need to restart */
2679                         goto restart;
2680         }
2681         spin_unlock_bh(&block->queue_lock);
2682         /* Now call the callback function of flushed requests */
2683 restart_cb:
2684         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2685                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2686                 /* Process finished ERP request. */
2687                 if (cqr->refers) {
2688                         spin_lock_bh(&block->queue_lock);
2689                         __dasd_process_erp(block->base, cqr);
2690                         spin_unlock_bh(&block->queue_lock);
2691                         /* restart list_for_xx loop since dasd_process_erp
2692                          * might remove multiple elements */
2693                         goto restart_cb;
2694                 }
2695                 /* call the callback function */
2696                 spin_lock_irq(&block->request_queue_lock);
2697                 cqr->endclk = get_clock();
2698                 list_del_init(&cqr->blocklist);
2699                 __dasd_cleanup_cqr(cqr);
2700                 spin_unlock_irq(&block->request_queue_lock);
2701         }
2702         return rc;
2703 }
2704
2705 /*
2706  * Schedules a call to dasd_tasklet over the device tasklet.
2707  */
2708 void dasd_schedule_block_bh(struct dasd_block *block)
2709 {
2710         /* Protect against rescheduling. */
2711         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2712                 return;
2713         /* life cycle of block is bound to it's base device */
2714         dasd_get_device(block->base);
2715         tasklet_hi_schedule(&block->tasklet);
2716 }
2717
2718
2719 /*
2720  * SECTION: external block device operations
2721  * (request queue handling, open, release, etc.)
2722  */
2723
2724 /*
2725  * Dasd request queue function. Called from ll_rw_blk.c
2726  */
2727 static void do_dasd_request(struct request_queue *queue)
2728 {
2729         struct dasd_block *block;
2730
2731         block = queue->queuedata;
2732         spin_lock(&block->queue_lock);
2733         /* Get new request from the block device request queue */
2734         __dasd_process_request_queue(block);
2735         /* Now check if the head of the ccw queue needs to be started. */
2736         __dasd_block_start_head(block);
2737         spin_unlock(&block->queue_lock);
2738 }
2739
2740 /*
2741  * Allocate and initialize request queue and default I/O scheduler.
2742  */
2743 static int dasd_alloc_queue(struct dasd_block *block)
2744 {
2745         int rc;
2746
2747         block->request_queue = blk_init_queue(do_dasd_request,
2748                                                &block->request_queue_lock);
2749         if (block->request_queue == NULL)
2750                 return -ENOMEM;
2751
2752         block->request_queue->queuedata = block;
2753
2754         elevator_exit(block->request_queue->elevator);
2755         block->request_queue->elevator = NULL;
2756         rc = elevator_init(block->request_queue, "deadline");
2757         if (rc) {
2758                 blk_cleanup_queue(block->request_queue);
2759                 return rc;
2760         }
2761         return 0;
2762 }
2763
2764 /*
2765  * Allocate and initialize request queue.
2766  */
2767 static void dasd_setup_queue(struct dasd_block *block)
2768 {
2769         int max;
2770
2771         if (block->base->features & DASD_FEATURE_USERAW) {
2772                 /*
2773                  * the max_blocks value for raw_track access is 256
2774                  * it is higher than the native ECKD value because we
2775                  * only need one ccw per track
2776                  * so the max_hw_sectors are
2777                  * 2048 x 512B = 1024kB = 16 tracks
2778                  */
2779                 max = 2048;
2780         } else {
2781                 max = block->base->discipline->max_blocks << block->s2b_shift;
2782         }
2783         blk_queue_logical_block_size(block->request_queue,
2784                                      block->bp_block);
2785         blk_queue_max_hw_sectors(block->request_queue, max);
2786         blk_queue_max_segments(block->request_queue, -1L);
2787         /* with page sized segments we can translate each segement into
2788          * one idaw/tidaw
2789          */
2790         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
2791         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
2792 }
2793
2794 /*
2795  * Deactivate and free request queue.
2796  */
2797 static void dasd_free_queue(struct dasd_block *block)
2798 {
2799         if (block->request_queue) {
2800                 blk_cleanup_queue(block->request_queue);
2801                 block->request_queue = NULL;
2802         }
2803 }
2804
2805 /*
2806  * Flush request on the request queue.
2807  */
2808 static void dasd_flush_request_queue(struct dasd_block *block)
2809 {
2810         struct request *req;
2811
2812         if (!block->request_queue)
2813                 return;
2814
2815         spin_lock_irq(&block->request_queue_lock);
2816         while ((req = blk_fetch_request(block->request_queue)))
2817                 __blk_end_request_all(req, -EIO);
2818         spin_unlock_irq(&block->request_queue_lock);
2819 }
2820
2821 static int dasd_open(struct block_device *bdev, fmode_t mode)
2822 {
2823         struct dasd_device *base;
2824         int rc;
2825
2826         base = dasd_device_from_gendisk(bdev->bd_disk);
2827         if (!base)
2828                 return -ENODEV;
2829
2830         atomic_inc(&base->block->open_count);
2831         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
2832                 rc = -ENODEV;
2833                 goto unlock;
2834         }
2835
2836         if (!try_module_get(base->discipline->owner)) {
2837                 rc = -EINVAL;
2838                 goto unlock;
2839         }
2840
2841         if (dasd_probeonly) {
2842                 dev_info(&base->cdev->dev,
2843                          "Accessing the DASD failed because it is in "
2844                          "probeonly mode\n");
2845                 rc = -EPERM;
2846                 goto out;
2847         }
2848
2849         if (base->state <= DASD_STATE_BASIC) {
2850                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
2851                               " Cannot open unrecognized device");
2852                 rc = -ENODEV;
2853                 goto out;
2854         }
2855
2856         if ((mode & FMODE_WRITE) &&
2857             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
2858              (base->features & DASD_FEATURE_READONLY))) {
2859                 rc = -EROFS;
2860                 goto out;
2861         }
2862
2863         dasd_put_device(base);
2864         return 0;
2865
2866 out:
2867         module_put(base->discipline->owner);
2868 unlock:
2869         atomic_dec(&base->block->open_count);
2870         dasd_put_device(base);
2871         return rc;
2872 }
2873
2874 static int dasd_release(struct gendisk *disk, fmode_t mode)
2875 {
2876         struct dasd_device *base;
2877
2878         base = dasd_device_from_gendisk(disk);
2879         if (!base)
2880                 return -ENODEV;
2881
2882         atomic_dec(&base->block->open_count);
2883         module_put(base->discipline->owner);
2884         dasd_put_device(base);
2885         return 0;
2886 }
2887
2888 /*
2889  * Return disk geometry.
2890  */
2891 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2892 {
2893         struct dasd_device *base;
2894
2895         base = dasd_device_from_gendisk(bdev->bd_disk);
2896         if (!base)
2897                 return -ENODEV;
2898
2899         if (!base->discipline ||
2900             !base->discipline->fill_geometry) {
2901                 dasd_put_device(base);
2902                 return -EINVAL;
2903         }
2904         base->discipline->fill_geometry(base->block, geo);
2905         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
2906         dasd_put_device(base);
2907         return 0;
2908 }
2909
2910 const struct block_device_operations
2911 dasd_device_operations = {
2912         .owner          = THIS_MODULE,
2913         .open           = dasd_open,
2914         .release        = dasd_release,
2915         .ioctl          = dasd_ioctl,
2916         .compat_ioctl   = dasd_ioctl,
2917         .getgeo         = dasd_getgeo,
2918 };
2919
2920 /*******************************************************************************
2921  * end of block device operations
2922  */
2923
2924 static void
2925 dasd_exit(void)
2926 {
2927 #ifdef CONFIG_PROC_FS
2928         dasd_proc_exit();
2929 #endif
2930         dasd_eer_exit();
2931         if (dasd_page_cache != NULL) {
2932                 kmem_cache_destroy(dasd_page_cache);
2933                 dasd_page_cache = NULL;
2934         }
2935         dasd_gendisk_exit();
2936         dasd_devmap_exit();
2937         if (dasd_debug_area != NULL) {
2938                 debug_unregister(dasd_debug_area);
2939                 dasd_debug_area = NULL;
2940         }
2941         dasd_statistics_removeroot();
2942 }
2943
2944 /*
2945  * SECTION: common functions for ccw_driver use
2946  */
2947
2948 /*
2949  * Is the device read-only?
2950  * Note that this function does not report the setting of the
2951  * readonly device attribute, but how it is configured in z/VM.
2952  */
2953 int dasd_device_is_ro(struct dasd_device *device)
2954 {
2955         struct ccw_dev_id dev_id;
2956         struct diag210 diag_data;
2957         int rc;
2958
2959         if (!MACHINE_IS_VM)
2960                 return 0;
2961         ccw_device_get_id(device->cdev, &dev_id);
2962         memset(&diag_data, 0, sizeof(diag_data));
2963         diag_data.vrdcdvno = dev_id.devno;
2964         diag_data.vrdclen = sizeof(diag_data);
2965         rc = diag210(&diag_data);
2966         if (rc == 0 || rc == 2) {
2967                 return diag_data.vrdcvfla & 0x80;
2968         } else {
2969                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
2970                           dev_id.devno, rc);
2971                 return 0;
2972         }
2973 }
2974 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
2975
2976 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
2977 {
2978         struct ccw_device *cdev = data;
2979         int ret;
2980
2981         ret = ccw_device_set_online(cdev);
2982         if (ret)
2983                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
2984                            dev_name(&cdev->dev), ret);
2985 }
2986
2987 /*
2988  * Initial attempt at a probe function. this can be simplified once
2989  * the other detection code is gone.
2990  */
2991 int dasd_generic_probe(struct ccw_device *cdev,
2992                        struct dasd_discipline *discipline)
2993 {
2994         int ret;
2995
2996         ret = dasd_add_sysfs_files(cdev);
2997         if (ret) {
2998                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
2999                                 "dasd_generic_probe: could not add "
3000                                 "sysfs entries");
3001                 return ret;
3002         }
3003         cdev->handler = &dasd_int_handler;
3004
3005         /*
3006          * Automatically online either all dasd devices (dasd_autodetect)
3007          * or all devices specified with dasd= parameters during
3008          * initial probe.
3009          */
3010         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3011             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3012                 async_schedule(dasd_generic_auto_online, cdev);
3013         return 0;
3014 }
3015
3016 /*
3017  * This will one day be called from a global not_oper handler.
3018  * It is also used by driver_unregister during module unload.
3019  */
3020 void dasd_generic_remove(struct ccw_device *cdev)
3021 {
3022         struct dasd_device *device;
3023         struct dasd_block *block;
3024
3025         cdev->handler = NULL;
3026
3027         dasd_remove_sysfs_files(cdev);
3028         device = dasd_device_from_cdev(cdev);
3029         if (IS_ERR(device))
3030                 return;
3031         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3032                 /* Already doing offline processing */
3033                 dasd_put_device(device);
3034                 return;
3035         }
3036         /*
3037          * This device is removed unconditionally. Set offline
3038          * flag to prevent dasd_open from opening it while it is
3039          * no quite down yet.
3040          */
3041         dasd_set_target_state(device, DASD_STATE_NEW);
3042         /* dasd_delete_device destroys the device reference. */
3043         block = device->block;
3044         dasd_delete_device(device);
3045         /*
3046          * life cycle of block is bound to device, so delete it after
3047          * device was safely removed
3048          */
3049         if (block)
3050                 dasd_free_block(block);
3051 }
3052
3053 /*
3054  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3055  * the device is detected for the first time and is supposed to be used
3056  * or the user has started activation through sysfs.
3057  */
3058 int dasd_generic_set_online(struct ccw_device *cdev,
3059                             struct dasd_discipline *base_discipline)
3060 {
3061         struct dasd_discipline *discipline;
3062         struct dasd_device *device;
3063         int rc;
3064
3065         /* first online clears initial online feature flag */
3066         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3067         device = dasd_create_device(cdev);
3068         if (IS_ERR(device))
3069                 return PTR_ERR(device);
3070
3071         discipline = base_discipline;
3072         if (device->features & DASD_FEATURE_USEDIAG) {
3073                 if (!dasd_diag_discipline_pointer) {
3074                         pr_warning("%s Setting the DASD online failed because "
3075                                    "of missing DIAG discipline\n",
3076                                    dev_name(&cdev->dev));
3077                         dasd_delete_device(device);
3078                         return -ENODEV;
3079                 }
3080                 discipline = dasd_diag_discipline_pointer;
3081         }
3082         if (!try_module_get(base_discipline->owner)) {
3083                 dasd_delete_device(device);
3084                 return -EINVAL;
3085         }
3086         if (!try_module_get(discipline->owner)) {
3087                 module_put(base_discipline->owner);
3088                 dasd_delete_device(device);
3089                 return -EINVAL;
3090         }
3091         device->base_discipline = base_discipline;
3092         device->discipline = discipline;
3093
3094         /* check_device will allocate block device if necessary */
3095         rc = discipline->check_device(device);
3096         if (rc) {
3097                 pr_warning("%s Setting the DASD online with discipline %s "
3098                            "failed with rc=%i\n",
3099                            dev_name(&cdev->dev), discipline->name, rc);
3100                 module_put(discipline->owner);
3101                 module_put(base_discipline->owner);
3102                 dasd_delete_device(device);
3103                 return rc;
3104         }
3105
3106         dasd_set_target_state(device, DASD_STATE_ONLINE);
3107         if (device->state <= DASD_STATE_KNOWN) {
3108                 pr_warning("%s Setting the DASD online failed because of a "
3109                            "missing discipline\n", dev_name(&cdev->dev));
3110                 rc = -ENODEV;
3111                 dasd_set_target_state(device, DASD_STATE_NEW);
3112                 if (device->block)
3113                         dasd_free_block(device->block);
3114                 dasd_delete_device(device);
3115         } else
3116                 pr_debug("dasd_generic device %s found\n",
3117                                 dev_name(&cdev->dev));
3118
3119         wait_event(dasd_init_waitq, _wait_for_device(device));
3120
3121         dasd_put_device(device);
3122         return rc;
3123 }
3124
3125 int dasd_generic_set_offline(struct ccw_device *cdev)
3126 {
3127         struct dasd_device *device;
3128         struct dasd_block *block;
3129         int max_count, open_count;
3130
3131         device = dasd_device_from_cdev(cdev);
3132         if (IS_ERR(device))
3133                 return PTR_ERR(device);
3134         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3135                 /* Already doing offline processing */
3136                 dasd_put_device(device);
3137                 return 0;
3138         }
3139         /*
3140          * We must make sure that this device is currently not in use.
3141          * The open_count is increased for every opener, that includes
3142          * the blkdev_get in dasd_scan_partitions. We are only interested
3143          * in the other openers.
3144          */
3145         if (device->block) {
3146                 max_count = device->block->bdev ? 0 : -1;
3147                 open_count = atomic_read(&device->block->open_count);
3148                 if (open_count > max_count) {
3149                         if (open_count > 0)
3150                                 pr_warning("%s: The DASD cannot be set offline "
3151                                            "with open count %i\n",
3152                                            dev_name(&cdev->dev), open_count);
3153                         else
3154                                 pr_warning("%s: The DASD cannot be set offline "
3155                                            "while it is in use\n",
3156                                            dev_name(&cdev->dev));
3157                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3158                         dasd_put_device(device);
3159                         return -EBUSY;
3160                 }
3161         }
3162         dasd_set_target_state(device, DASD_STATE_NEW);
3163         /* dasd_delete_device destroys the device reference. */
3164         block = device->block;
3165         dasd_delete_device(device);
3166         /*
3167          * life cycle of block is bound to device, so delete it after
3168          * device was safely removed
3169          */
3170         if (block)
3171                 dasd_free_block(block);
3172         return 0;
3173 }
3174
3175 int dasd_generic_last_path_gone(struct dasd_device *device)
3176 {
3177         struct dasd_ccw_req *cqr;
3178
3179         dev_warn(&device->cdev->dev, "No operational channel path is left "
3180                  "for the device\n");
3181         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3182         /* First of all call extended error reporting. */
3183         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3184
3185         if (device->state < DASD_STATE_BASIC)
3186                 return 0;
3187         /* Device is active. We want to keep it. */
3188         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3189                 if ((cqr->status == DASD_CQR_IN_IO) ||
3190                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3191                         cqr->status = DASD_CQR_QUEUED;
3192                         cqr->retries++;
3193                 }
3194         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3195         dasd_device_clear_timer(device);
3196         dasd_schedule_device_bh(device);
3197         return 1;
3198 }
3199 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3200
3201 int dasd_generic_path_operational(struct dasd_device *device)
3202 {
3203         dev_info(&device->cdev->dev, "A channel path to the device has become "
3204                  "operational\n");
3205         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3206         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3207         if (device->stopped & DASD_UNRESUMED_PM) {
3208                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3209                 dasd_restore_device(device);
3210                 return 1;
3211         }
3212         dasd_schedule_device_bh(device);
3213         if (device->block)
3214                 dasd_schedule_block_bh(device->block);
3215         return 1;
3216 }
3217 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3218
3219 int dasd_generic_notify(struct ccw_device *cdev, int event)
3220 {
3221         struct dasd_device *device;
3222         int ret;
3223
3224         device = dasd_device_from_cdev_locked(cdev);
3225         if (IS_ERR(device))
3226                 return 0;
3227         ret = 0;
3228         switch (event) {
3229         case CIO_GONE:
3230         case CIO_BOXED:
3231         case CIO_NO_PATH:
3232                 device->path_data.opm = 0;
3233                 device->path_data.ppm = 0;
3234                 device->path_data.npm = 0;
3235                 ret = dasd_generic_last_path_gone(device);
3236                 break;
3237         case CIO_OPER:
3238                 ret = 1;
3239                 if (device->path_data.opm)
3240                         ret = dasd_generic_path_operational(device);
3241                 break;
3242         }
3243         dasd_put_device(device);
3244         return ret;
3245 }
3246
3247 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3248 {
3249         int chp;
3250         __u8 oldopm, eventlpm;
3251         struct dasd_device *device;
3252
3253         device = dasd_device_from_cdev_locked(cdev);
3254         if (IS_ERR(device))
3255                 return;
3256         for (chp = 0; chp < 8; chp++) {
3257                 eventlpm = 0x80 >> chp;
3258                 if (path_event[chp] & PE_PATH_GONE) {
3259                         oldopm = device->path_data.opm;
3260                         device->path_data.opm &= ~eventlpm;
3261                         device->path_data.ppm &= ~eventlpm;
3262                         device->path_data.npm &= ~eventlpm;
3263                         if (oldopm && !device->path_data.opm)
3264                                 dasd_generic_last_path_gone(device);
3265                 }
3266                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3267                         device->path_data.opm &= ~eventlpm;
3268                         device->path_data.ppm &= ~eventlpm;
3269                         device->path_data.npm &= ~eventlpm;
3270                         device->path_data.tbvpm |= eventlpm;
3271                         dasd_schedule_device_bh(device);
3272                 }
3273                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3274                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3275                                       "Pathgroup re-established\n");
3276                         if (device->discipline->kick_validate)
3277                                 device->discipline->kick_validate(device);
3278                 }
3279         }
3280         dasd_put_device(device);
3281 }
3282 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3283
3284 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3285 {
3286         if (!device->path_data.opm && lpm) {
3287                 device->path_data.opm = lpm;
3288                 dasd_generic_path_operational(device);
3289         } else
3290                 device->path_data.opm |= lpm;
3291         return 0;
3292 }
3293 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3294
3295
3296 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3297 {
3298         struct dasd_ccw_req *cqr, *n;
3299         int rc;
3300         struct list_head freeze_queue;
3301         struct dasd_device *device = dasd_device_from_cdev(cdev);
3302
3303         if (IS_ERR(device))
3304                 return PTR_ERR(device);
3305
3306         /* mark device as suspended */
3307         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3308
3309         if (device->discipline->freeze)
3310                 rc = device->discipline->freeze(device);
3311
3312         /* disallow new I/O  */
3313         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3314         /* clear active requests */
3315         INIT_LIST_HEAD(&freeze_queue);
3316         spin_lock_irq(get_ccwdev_lock(cdev));
3317         rc = 0;
3318         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3319                 /* Check status and move request to flush_queue */
3320                 if (cqr->status == DASD_CQR_IN_IO) {
3321                         rc = device->discipline->term_IO(cqr);
3322                         if (rc) {
3323                                 /* unable to terminate requeust */
3324                                 dev_err(&device->cdev->dev,
3325                                         "Unable to terminate request %p "
3326                                         "on suspend\n", cqr);
3327                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3328                                 dasd_put_device(device);
3329                                 return rc;
3330                         }
3331                 }
3332                 list_move_tail(&cqr->devlist, &freeze_queue);
3333         }
3334
3335         spin_unlock_irq(get_ccwdev_lock(cdev));
3336
3337         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3338                 wait_event(dasd_flush_wq,
3339                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3340                 if (cqr->status == DASD_CQR_CLEARED)
3341                         cqr->status = DASD_CQR_QUEUED;
3342         }
3343         /* move freeze_queue to start of the ccw_queue */
3344         spin_lock_irq(get_ccwdev_lock(cdev));
3345         list_splice_tail(&freeze_queue, &device->ccw_queue);
3346         spin_unlock_irq(get_ccwdev_lock(cdev));
3347
3348         dasd_put_device(device);
3349         return rc;
3350 }
3351 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3352
3353 int dasd_generic_restore_device(struct ccw_device *cdev)
3354 {
3355         struct dasd_device *device = dasd_device_from_cdev(cdev);
3356         int rc = 0;
3357
3358         if (IS_ERR(device))
3359                 return PTR_ERR(device);
3360
3361         /* allow new IO again */
3362         dasd_device_remove_stop_bits(device,
3363                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3364
3365         dasd_schedule_device_bh(device);
3366
3367         /*
3368          * call discipline restore function
3369          * if device is stopped do nothing e.g. for disconnected devices
3370          */
3371         if (device->discipline->restore && !(device->stopped))
3372                 rc = device->discipline->restore(device);
3373         if (rc || device->stopped)
3374                 /*
3375                  * if the resume failed for the DASD we put it in
3376                  * an UNRESUMED stop state
3377                  */
3378                 device->stopped |= DASD_UNRESUMED_PM;
3379
3380         if (device->block)
3381                 dasd_schedule_block_bh(device->block);
3382
3383         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3384         dasd_put_device(device);
3385         return 0;
3386 }
3387 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3388
3389 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3390                                                    void *rdc_buffer,
3391                                                    int rdc_buffer_size,
3392                                                    int magic)
3393 {
3394         struct dasd_ccw_req *cqr;
3395         struct ccw1 *ccw;
3396         unsigned long *idaw;
3397
3398         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3399
3400         if (IS_ERR(cqr)) {
3401                 /* internal error 13 - Allocating the RDC request failed*/
3402                 dev_err(&device->cdev->dev,
3403                          "An error occurred in the DASD device driver, "
3404                          "reason=%s\n", "13");
3405                 return cqr;
3406         }
3407
3408         ccw = cqr->cpaddr;
3409         ccw->cmd_code = CCW_CMD_RDC;
3410         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3411                 idaw = (unsigned long *) (cqr->data);
3412                 ccw->cda = (__u32)(addr_t) idaw;
3413                 ccw->flags = CCW_FLAG_IDA;
3414                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3415         } else {
3416                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3417                 ccw->flags = 0;
3418         }
3419
3420         ccw->count = rdc_buffer_size;
3421         cqr->startdev = device;
3422         cqr->memdev = device;
3423         cqr->expires = 10*HZ;
3424         cqr->retries = 256;
3425         cqr->buildclk = get_clock();
3426         cqr->status = DASD_CQR_FILLED;
3427         return cqr;
3428 }
3429
3430
3431 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3432                                 void *rdc_buffer, int rdc_buffer_size)
3433 {
3434         int ret;
3435         struct dasd_ccw_req *cqr;
3436
3437         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3438                                      magic);
3439         if (IS_ERR(cqr))
3440                 return PTR_ERR(cqr);
3441
3442         ret = dasd_sleep_on(cqr);
3443         dasd_sfree_request(cqr, cqr->memdev);
3444         return ret;
3445 }
3446 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3447
3448 /*
3449  *   In command mode and transport mode we need to look for sense
3450  *   data in different places. The sense data itself is allways
3451  *   an array of 32 bytes, so we can unify the sense data access
3452  *   for both modes.
3453  */
3454 char *dasd_get_sense(struct irb *irb)
3455 {
3456         struct tsb *tsb = NULL;
3457         char *sense = NULL;
3458
3459         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3460                 if (irb->scsw.tm.tcw)
3461                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3462                                           irb->scsw.tm.tcw);
3463                 if (tsb && tsb->length == 64 && tsb->flags)
3464                         switch (tsb->flags & 0x07) {
3465                         case 1: /* tsa_iostat */
3466                                 sense = tsb->tsa.iostat.sense;
3467                                 break;
3468                         case 2: /* tsa_ddpc */
3469                                 sense = tsb->tsa.ddpc.sense;
3470                                 break;
3471                         default:
3472                                 /* currently we don't use interrogate data */
3473                                 break;
3474                         }
3475         } else if (irb->esw.esw0.erw.cons) {
3476                 sense = irb->ecw;
3477         }
3478         return sense;
3479 }
3480 EXPORT_SYMBOL_GPL(dasd_get_sense);
3481
3482 static inline int _wait_for_empty_queues(struct dasd_device *device)
3483 {
3484         if (device->block)
3485                 return list_empty(&device->ccw_queue) &&
3486                         list_empty(&device->block->ccw_queue);
3487         else
3488                 return list_empty(&device->ccw_queue);
3489 }
3490
3491 void dasd_generic_shutdown(struct ccw_device *cdev)
3492 {
3493         struct dasd_device *device;
3494
3495         device = dasd_device_from_cdev(cdev);
3496         if (IS_ERR(device))
3497                 return;
3498
3499         if (device->block)
3500                 dasd_schedule_block_bh(device->block);
3501
3502         dasd_schedule_device_bh(device);
3503
3504         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3505 }
3506 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3507
3508 static int __init dasd_init(void)
3509 {
3510         int rc;
3511
3512         init_waitqueue_head(&dasd_init_waitq);
3513         init_waitqueue_head(&dasd_flush_wq);
3514         init_waitqueue_head(&generic_waitq);
3515         init_waitqueue_head(&shutdown_waitq);
3516
3517         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3518         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3519         if (dasd_debug_area == NULL) {
3520                 rc = -ENOMEM;
3521                 goto failed;
3522         }
3523         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3524         debug_set_level(dasd_debug_area, DBF_WARNING);
3525
3526         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3527
3528         dasd_diag_discipline_pointer = NULL;
3529
3530         dasd_statistics_createroot();
3531
3532         rc = dasd_devmap_init();
3533         if (rc)
3534                 goto failed;
3535         rc = dasd_gendisk_init();
3536         if (rc)
3537                 goto failed;
3538         rc = dasd_parse();
3539         if (rc)
3540                 goto failed;
3541         rc = dasd_eer_init();
3542         if (rc)
3543                 goto failed;
3544 #ifdef CONFIG_PROC_FS
3545         rc = dasd_proc_init();
3546         if (rc)
3547                 goto failed;
3548 #endif
3549
3550         return 0;
3551 failed:
3552         pr_info("The DASD device driver could not be initialized\n");
3553         dasd_exit();
3554         return rc;
3555 }
3556
3557 module_init(dasd_init);
3558 module_exit(dasd_exit);
3559
3560 EXPORT_SYMBOL(dasd_debug_area);
3561 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
3562
3563 EXPORT_SYMBOL(dasd_add_request_head);
3564 EXPORT_SYMBOL(dasd_add_request_tail);
3565 EXPORT_SYMBOL(dasd_cancel_req);
3566 EXPORT_SYMBOL(dasd_device_clear_timer);
3567 EXPORT_SYMBOL(dasd_block_clear_timer);
3568 EXPORT_SYMBOL(dasd_enable_device);
3569 EXPORT_SYMBOL(dasd_int_handler);
3570 EXPORT_SYMBOL(dasd_kfree_request);
3571 EXPORT_SYMBOL(dasd_kick_device);
3572 EXPORT_SYMBOL(dasd_kmalloc_request);
3573 EXPORT_SYMBOL(dasd_schedule_device_bh);
3574 EXPORT_SYMBOL(dasd_schedule_block_bh);
3575 EXPORT_SYMBOL(dasd_set_target_state);
3576 EXPORT_SYMBOL(dasd_device_set_timer);
3577 EXPORT_SYMBOL(dasd_block_set_timer);
3578 EXPORT_SYMBOL(dasd_sfree_request);
3579 EXPORT_SYMBOL(dasd_sleep_on);
3580 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
3581 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
3582 EXPORT_SYMBOL(dasd_smalloc_request);
3583 EXPORT_SYMBOL(dasd_start_IO);
3584 EXPORT_SYMBOL(dasd_term_IO);
3585
3586 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3587 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3588 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3589 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3590 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3591 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
3592 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
3593 EXPORT_SYMBOL_GPL(dasd_alloc_block);
3594 EXPORT_SYMBOL_GPL(dasd_free_block);