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/buffer_head.h>
  21 #include <linux/hdreg.h>
  22 #include <linux/async.h>
  23 #include <linux/mutex.h>
  24
  25 #include <asm/ccwdev.h>
  26 #include <asm/ebcdic.h>
  27 #include <asm/idals.h>
  28 #include <asm/itcw.h>
  29 #include <asm/diag.h>
  30
  31 /* This is ugly... */
  32 #define PRINTK_HEADER "dasd:"
  33
  34 #include "dasd_int.h"
  35 /*
  36  * SECTION: Constant definitions to be used within this file
  37  */
  38 #define DASD_CHANQ_MAX_SIZE 4
  39
  40 #define DASD_SLEEPON_START_TAG  (void *) 1
  41 #define DASD_SLEEPON_END_TAG    (void *) 2
  42
  43 /*
  44  * SECTION: exported variables of dasd.c
  45  */
  46 debug_info_t *dasd_debug_area;
  47 struct dasd_discipline *dasd_diag_discipline_pointer;
  48 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  49
  50 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  51 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  52                    " Copyright 2000 IBM Corporation");
  53 MODULE_SUPPORTED_DEVICE("dasd");
  54 MODULE_LICENSE("GPL");
  55
  56 /*
  57  * SECTION: prototypes for static functions of dasd.c
  58  */
  59 static int  dasd_alloc_queue(struct dasd_block *);
  60 static void dasd_setup_queue(struct dasd_block *);
  61 static void dasd_free_queue(struct dasd_block *);
  62 static void dasd_flush_request_queue(struct dasd_block *);
  63 static int dasd_flush_block_queue(struct dasd_block *);
  64 static void dasd_device_tasklet(struct dasd_device *);
  65 static void dasd_block_tasklet(struct dasd_block *);
  66 static void do_kick_device(struct work_struct *);
  67 static void do_restore_device(struct work_struct *);
  68 static void do_reload_device(struct work_struct *);
  69 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  70 static void dasd_device_timeout(unsigned long);
  71 static void dasd_block_timeout(unsigned long);
  72 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  73
  74 /*
  75  * SECTION: Operations on the device structure.
  76  */
  77 static wait_queue_head_t dasd_init_waitq;
  78 static wait_queue_head_t dasd_flush_wq;
  79 static wait_queue_head_t generic_waitq;
  80
  81 /*
  82  * Allocate memory for a new device structure.
  83  */
  84 struct dasd_device *dasd_alloc_device(void)
  85 {
  86         struct dasd_device *device;
  87
  88         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  89         if (!device)
  90                 return ERR_PTR(-ENOMEM);
  91
  92         /* Get two pages for normal block device operations. */
  93         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  94         if (!device->ccw_mem) {
  95                 kfree(device);
  96                 return ERR_PTR(-ENOMEM);
  97         }
  98         /* Get one page for error recovery. */
  99         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 100         if (!device->erp_mem) {
 101                 free_pages((unsigned long) device->ccw_mem, 1);
 102                 kfree(device);
 103                 return ERR_PTR(-ENOMEM);
 104         }
 105
 106         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 107         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 108         spin_lock_init(&device->mem_lock);
 109         atomic_set(&device->tasklet_scheduled, 0);
 110         tasklet_init(&device->tasklet,
 111                      (void (*)(unsigned long)) dasd_device_tasklet,
 112                      (unsigned long) device);
 113         INIT_LIST_HEAD(&device->ccw_queue);
 114         init_timer(&device->timer);
 115         device->timer.function = dasd_device_timeout;
 116         device->timer.data = (unsigned long) device;
 117         INIT_WORK(&device->kick_work, do_kick_device);
 118         INIT_WORK(&device->restore_device, do_restore_device);
 119         INIT_WORK(&device->reload_device, do_reload_device);
 120         device->state = DASD_STATE_NEW;
 121         device->target = DASD_STATE_NEW;
 122         mutex_init(&device->state_mutex);
 123
 124         return device;
 125 }
 126
 127 /*
 128  * Free memory of a device structure.
 129  */
 130 void dasd_free_device(struct dasd_device *device)
 131 {
 132         kfree(device->private);
 133         free_page((unsigned long) device->erp_mem);
 134         free_pages((unsigned long) device->ccw_mem, 1);
 135         kfree(device);
 136 }
 137
 138 /*
 139  * Allocate memory for a new device structure.
 140  */
 141 struct dasd_block *dasd_alloc_block(void)
 142 {
 143         struct dasd_block *block;
 144
 145         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 146         if (!block)
 147                 return ERR_PTR(-ENOMEM);
 148         /* open_count = 0 means device online but not in use */
 149         atomic_set(&block->open_count, -1);
 150
 151         spin_lock_init(&block->request_queue_lock);
 152         atomic_set(&block->tasklet_scheduled, 0);
 153         tasklet_init(&block->tasklet,
 154                      (void (*)(unsigned long)) dasd_block_tasklet,
 155                      (unsigned long) block);
 156         INIT_LIST_HEAD(&block->ccw_queue);
 157         spin_lock_init(&block->queue_lock);
 158         init_timer(&block->timer);
 159         block->timer.function = dasd_block_timeout;
 160         block->timer.data = (unsigned long) block;
 161
 162         return block;
 163 }
 164
 165 /*
 166  * Free memory of a device structure.
 167  */
 168 void dasd_free_block(struct dasd_block *block)
 169 {
 170         kfree(block);
 171 }
 172
 173 /*
 174  * Make a new device known to the system.
 175  */
 176 static int dasd_state_new_to_known(struct dasd_device *device)
 177 {
 178         int rc;
 179
 180         /*
 181          * As long as the device is not in state DASD_STATE_NEW we want to
 182          * keep the reference count > 0.
 183          */
 184         dasd_get_device(device);
 185
 186         if (device->block) {
 187                 rc = dasd_alloc_queue(device->block);
 188                 if (rc) {
 189                         dasd_put_device(device);
 190                         return rc;
 191                 }
 192         }
 193         device->state = DASD_STATE_KNOWN;
 194         return 0;
 195 }
 196
 197 /*
 198  * Let the system forget about a device.
 199  */
 200 static int dasd_state_known_to_new(struct dasd_device *device)
 201 {
 202         /* Disable extended error reporting for this device. */
 203         dasd_eer_disable(device);
 204         /* Forget the discipline information. */
 205         if (device->discipline) {
 206                 if (device->discipline->uncheck_device)
 207                         device->discipline->uncheck_device(device);
 208                 module_put(device->discipline->owner);
 209         }
 210         device->discipline = NULL;
 211         if (device->base_discipline)
 212                 module_put(device->base_discipline->owner);
 213         device->base_discipline = NULL;
 214         device->state = DASD_STATE_NEW;
 215
 216         if (device->block)
 217                 dasd_free_queue(device->block);
 218
 219         /* Give up reference we took in dasd_state_new_to_known. */
 220         dasd_put_device(device);
 221         return 0;
 222 }
 223
 224 /*
 225  * Request the irq line for the device.
 226  */
 227 static int dasd_state_known_to_basic(struct dasd_device *device)
 228 {
 229         int rc;
 230
 231         /* Allocate and register gendisk structure. */
 232         if (device->block) {
 233                 rc = dasd_gendisk_alloc(device->block);
 234                 if (rc)
 235                         return rc;
 236         }
 237         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 238         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 239                                             8 * sizeof(long));
 240         debug_register_view(device->debug_area, &debug_sprintf_view);
 241         debug_set_level(device->debug_area, DBF_WARNING);
 242         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 243
 244         device->state = DASD_STATE_BASIC;
 245         return 0;
 246 }
 247
 248 /*
 249  * Release the irq line for the device. Terminate any running i/o.
 250  */
 251 static int dasd_state_basic_to_known(struct dasd_device *device)
 252 {
 253         int rc;
 254         if (device->block) {
 255                 dasd_gendisk_free(device->block);
 256                 dasd_block_clear_timer(device->block);
 257         }
 258         rc = dasd_flush_device_queue(device);
 259         if (rc)
 260                 return rc;
 261         dasd_device_clear_timer(device);
 262
 263         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 264         if (device->debug_area != NULL) {
 265                 debug_unregister(device->debug_area);
 266                 device->debug_area = NULL;
 267         }
 268         device->state = DASD_STATE_KNOWN;
 269         return 0;
 270 }
 271
 272 /*
 273  * Do the initial analysis. The do_analysis function may return
 274  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 275  * until the discipline decides to continue the startup sequence
 276  * by calling the function dasd_change_state. The eckd disciplines
 277  * uses this to start a ccw that detects the format. The completion
 278  * interrupt for this detection ccw uses the kernel event daemon to
 279  * trigger the call to dasd_change_state. All this is done in the
 280  * discipline code, see dasd_eckd.c.
 281  * After the analysis ccw is done (do_analysis returned 0) the block
 282  * device is setup.
 283  * In case the analysis returns an error, the device setup is stopped
 284  * (a fake disk was already added to allow formatting).
 285  */
 286 static int dasd_state_basic_to_ready(struct dasd_device *device)
 287 {
 288         int rc;
 289         struct dasd_block *block;
 290
 291         rc = 0;
 292         block = device->block;
 293         /* make disk known with correct capacity */
 294         if (block) {
 295                 if (block->base->discipline->do_analysis != NULL)
 296                         rc = block->base->discipline->do_analysis(block);
 297                 if (rc) {
 298                         if (rc != -EAGAIN)
 299                                 device->state = DASD_STATE_UNFMT;
 300                         return rc;
 301                 }
 302                 dasd_setup_queue(block);
 303                 set_capacity(block->gdp,
 304                              block->blocks << block->s2b_shift);
 305                 device->state = DASD_STATE_READY;
 306                 rc = dasd_scan_partitions(block);
 307                 if (rc)
 308                         device->state = DASD_STATE_BASIC;
 309         } else {
 310                 device->state = DASD_STATE_READY;
 311         }
 312         return rc;
 313 }
 314
 315 /*
 316  * Remove device from block device layer. Destroy dirty buffers.
 317  * Forget format information. Check if the target level is basic
 318  * and if it is create fake disk for formatting.
 319  */
 320 static int dasd_state_ready_to_basic(struct dasd_device *device)
 321 {
 322         int rc;
 323
 324         device->state = DASD_STATE_BASIC;
 325         if (device->block) {
 326                 struct dasd_block *block = device->block;
 327                 rc = dasd_flush_block_queue(block);
 328                 if (rc) {
 329                         device->state = DASD_STATE_READY;
 330                         return rc;
 331                 }
 332                 dasd_flush_request_queue(block);
 333                 dasd_destroy_partitions(block);
 334                 block->blocks = 0;
 335                 block->bp_block = 0;
 336                 block->s2b_shift = 0;
 337         }
 338         return 0;
 339 }
 340
 341 /*
 342  * Back to basic.
 343  */
 344 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 345 {
 346         device->state = DASD_STATE_BASIC;
 347         return 0;
 348 }
 349
 350 /*
 351  * Make the device online and schedule the bottom half to start
 352  * the requeueing of requests from the linux request queue to the
 353  * ccw queue.
 354  */
 355 static int
 356 dasd_state_ready_to_online(struct dasd_device * device)
 357 {
 358         int rc;
 359         struct gendisk *disk;
 360         struct disk_part_iter piter;
 361         struct hd_struct *part;
 362
 363         if (device->discipline->ready_to_online) {
 364                 rc = device->discipline->ready_to_online(device);
 365                 if (rc)
 366                         return rc;
 367         }
 368         device->state = DASD_STATE_ONLINE;
 369         if (device->block) {
 370                 dasd_schedule_block_bh(device->block);
 371                 disk = device->block->bdev->bd_disk;
 372                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 373                 while ((part = disk_part_iter_next(&piter)))
 374                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 375                 disk_part_iter_exit(&piter);
 376         }
 377         return 0;
 378 }
 379
 380 /*
 381  * Stop the requeueing of requests again.
 382  */
 383 static int dasd_state_online_to_ready(struct dasd_device *device)
 384 {
 385         int rc;
 386         struct gendisk *disk;
 387         struct disk_part_iter piter;
 388         struct hd_struct *part;
 389
 390         if (device->discipline->online_to_ready) {
 391                 rc = device->discipline->online_to_ready(device);
 392                 if (rc)
 393                         return rc;
 394         }
 395         device->state = DASD_STATE_READY;
 396         if (device->block) {
 397                 disk = device->block->bdev->bd_disk;
 398                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 399                 while ((part = disk_part_iter_next(&piter)))
 400                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 401                 disk_part_iter_exit(&piter);
 402         }
 403         return 0;
 404 }
 405
 406 /*
 407  * Device startup state changes.
 408  */
 409 static int dasd_increase_state(struct dasd_device *device)
 410 {
 411         int rc;
 412
 413         rc = 0;
 414         if (device->state == DASD_STATE_NEW &&
 415             device->target >= DASD_STATE_KNOWN)
 416                 rc = dasd_state_new_to_known(device);
 417
 418         if (!rc &&
 419             device->state == DASD_STATE_KNOWN &&
 420             device->target >= DASD_STATE_BASIC)
 421                 rc = dasd_state_known_to_basic(device);
 422
 423         if (!rc &&
 424             device->state == DASD_STATE_BASIC &&
 425             device->target >= DASD_STATE_READY)
 426                 rc = dasd_state_basic_to_ready(device);
 427
 428         if (!rc &&
 429             device->state == DASD_STATE_UNFMT &&
 430             device->target > DASD_STATE_UNFMT)
 431                 rc = -EPERM;
 432
 433         if (!rc &&
 434             device->state == DASD_STATE_READY &&
 435             device->target >= DASD_STATE_ONLINE)
 436                 rc = dasd_state_ready_to_online(device);
 437
 438         return rc;
 439 }
 440
 441 /*
 442  * Device shutdown state changes.
 443  */
 444 static int dasd_decrease_state(struct dasd_device *device)
 445 {
 446         int rc;
 447
 448         rc = 0;
 449         if (device->state == DASD_STATE_ONLINE &&
 450             device->target <= DASD_STATE_READY)
 451                 rc = dasd_state_online_to_ready(device);
 452
 453         if (!rc &&
 454             device->state == DASD_STATE_READY &&
 455             device->target <= DASD_STATE_BASIC)
 456                 rc = dasd_state_ready_to_basic(device);
 457
 458         if (!rc &&
 459             device->state == DASD_STATE_UNFMT &&
 460             device->target <= DASD_STATE_BASIC)
 461                 rc = dasd_state_unfmt_to_basic(device);
 462
 463         if (!rc &&
 464             device->state == DASD_STATE_BASIC &&
 465             device->target <= DASD_STATE_KNOWN)
 466                 rc = dasd_state_basic_to_known(device);
 467
 468         if (!rc &&
 469             device->state == DASD_STATE_KNOWN &&
 470             device->target <= DASD_STATE_NEW)
 471                 rc = dasd_state_known_to_new(device);
 472
 473         return rc;
 474 }
 475
 476 /*
 477  * This is the main startup/shutdown routine.
 478  */
 479 static void dasd_change_state(struct dasd_device *device)
 480 {
 481         int rc;
 482
 483         if (device->state == device->target)
 484                 /* Already where we want to go today... */
 485                 return;
 486         if (device->state < device->target)
 487                 rc = dasd_increase_state(device);
 488         else
 489                 rc = dasd_decrease_state(device);
 490         if (rc == -EAGAIN)
 491                 return;
 492         if (rc)
 493                 device->target = device->state;
 494
 495         if (device->state == device->target)
 496                 wake_up(&dasd_init_waitq);
 497
 498         /* let user-space know that the device status changed */
 499         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 500 }
 501
 502 /*
 503  * Kick starter for devices that did not complete the startup/shutdown
 504  * procedure or were sleeping because of a pending state.
 505  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 506  * event daemon.
 507  */
 508 static void do_kick_device(struct work_struct *work)
 509 {
 510         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 511         mutex_lock(&device->state_mutex);
 512         dasd_change_state(device);
 513         mutex_unlock(&device->state_mutex);
 514         dasd_schedule_device_bh(device);
 515         dasd_put_device(device);
 516 }
 517
 518 void dasd_kick_device(struct dasd_device *device)
 519 {
 520         dasd_get_device(device);
 521         /* queue call to dasd_kick_device to the kernel event daemon. */
 522         schedule_work(&device->kick_work);
 523 }
 524
 525 /*
 526  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 527  * event daemon.
 528  */
 529 static void do_reload_device(struct work_struct *work)
 530 {
 531         struct dasd_device *device = container_of(work, struct dasd_device,
 532                                                   reload_device);
 533         device->discipline->reload(device);
 534         dasd_put_device(device);
 535 }
 536
 537 void dasd_reload_device(struct dasd_device *device)
 538 {
 539         dasd_get_device(device);
 540         /* queue call to dasd_reload_device to the kernel event daemon. */
 541         schedule_work(&device->reload_device);
 542 }
 543 EXPORT_SYMBOL(dasd_reload_device);
 544
 545 /*
 546  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 547  * event daemon.
 548  */
 549 static void do_restore_device(struct work_struct *work)
 550 {
 551         struct dasd_device *device = container_of(work, struct dasd_device,
 552                                                   restore_device);
 553         device->cdev->drv->restore(device->cdev);
 554         dasd_put_device(device);
 555 }
 556
 557 void dasd_restore_device(struct dasd_device *device)
 558 {
 559         dasd_get_device(device);
 560         /* queue call to dasd_restore_device to the kernel event daemon. */
 561         schedule_work(&device->restore_device);
 562 }
 563
 564 /*
 565  * Set the target state for a device and starts the state change.
 566  */
 567 void dasd_set_target_state(struct dasd_device *device, int target)
 568 {
 569         dasd_get_device(device);
 570         mutex_lock(&device->state_mutex);
 571         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 572         if (dasd_probeonly && target > DASD_STATE_READY)
 573                 target = DASD_STATE_READY;
 574         if (device->target != target) {
 575                 if (device->state == target)
 576                         wake_up(&dasd_init_waitq);
 577                 device->target = target;
 578         }
 579         if (device->state != device->target)
 580                 dasd_change_state(device);
 581         mutex_unlock(&device->state_mutex);
 582         dasd_put_device(device);
 583 }
 584
 585 /*
 586  * Enable devices with device numbers in [from..to].
 587  */
 588 static inline int _wait_for_device(struct dasd_device *device)
 589 {
 590         return (device->state == device->target);
 591 }
 592
 593 void dasd_enable_device(struct dasd_device *device)
 594 {
 595         dasd_set_target_state(device, DASD_STATE_ONLINE);
 596         if (device->state <= DASD_STATE_KNOWN)
 597                 /* No discipline for device found. */
 598                 dasd_set_target_state(device, DASD_STATE_NEW);
 599         /* Now wait for the devices to come up. */
 600         wait_event(dasd_init_waitq, _wait_for_device(device));
 601 }
 602
 603 /*
 604  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 605  */
 606 #ifdef CONFIG_DASD_PROFILE
 607
 608 struct dasd_profile_info_t dasd_global_profile;
 609 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
 610
 611 /*
 612  * Increments counter in global and local profiling structures.
 613  */
 614 #define dasd_profile_counter(value, counter, block) \
 615 { \
 616         int index; \
 617         for (index = 0; index < 31 && value >> (2+index); index++); \
 618         dasd_global_profile.counter[index]++; \
 619         block->profile.counter[index]++; \
 620 }
 621
 622 /*
 623  * Add profiling information for cqr before execution.
 624  */
 625 static void dasd_profile_start(struct dasd_block *block,
 626                                struct dasd_ccw_req *cqr,
 627                                struct request *req)
 628 {
 629         struct list_head *l;
 630         unsigned int counter;
 631
 632         if (dasd_profile_level != DASD_PROFILE_ON)
 633                 return;
 634
 635         /* count the length of the chanq for statistics */
 636         counter = 0;
 637         list_for_each(l, &block->ccw_queue)
 638                 if (++counter >= 31)
 639                         break;
 640         dasd_global_profile.dasd_io_nr_req[counter]++;
 641         block->profile.dasd_io_nr_req[counter]++;
 642 }
 643
 644 /*
 645  * Add profiling information for cqr after execution.
 646  */
 647 static void dasd_profile_end(struct dasd_block *block,
 648                              struct dasd_ccw_req *cqr,
 649                              struct request *req)
 650 {
 651         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 652         long tottimeps, sectors;
 653
 654         if (dasd_profile_level != DASD_PROFILE_ON)
 655                 return;
 656
 657         sectors = blk_rq_sectors(req);
 658         if (!cqr->buildclk || !cqr->startclk ||
 659             !cqr->stopclk || !cqr->endclk ||
 660             !sectors)
 661                 return;
 662
 663         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 664         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 665         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 666         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 667         tottimeps = tottime / sectors;
 668
 669         if (!dasd_global_profile.dasd_io_reqs)
 670                 memset(&dasd_global_profile, 0,
 671                        sizeof(struct dasd_profile_info_t));
 672         dasd_global_profile.dasd_io_reqs++;
 673         dasd_global_profile.dasd_io_sects += sectors;
 674
 675         if (!block->profile.dasd_io_reqs)
 676                 memset(&block->profile, 0,
 677                        sizeof(struct dasd_profile_info_t));
 678         block->profile.dasd_io_reqs++;
 679         block->profile.dasd_io_sects += sectors;
 680
 681         dasd_profile_counter(sectors, dasd_io_secs, block);
 682         dasd_profile_counter(tottime, dasd_io_times, block);
 683         dasd_profile_counter(tottimeps, dasd_io_timps, block);
 684         dasd_profile_counter(strtime, dasd_io_time1, block);
 685         dasd_profile_counter(irqtime, dasd_io_time2, block);
 686         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, block);
 687         dasd_profile_counter(endtime, dasd_io_time3, block);
 688 }
 689 #else
 690 #define dasd_profile_start(block, cqr, req) do {} while (0)
 691 #define dasd_profile_end(block, cqr, req) do {} while (0)
 692 #endif                          /* CONFIG_DASD_PROFILE */
 693
 694 /*
 695  * Allocate memory for a channel program with 'cplength' channel
 696  * command words and 'datasize' additional space. There are two
 697  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 698  * memory and 2) dasd_smalloc_request uses the static ccw memory
 699  * that gets allocated for each device.
 700  */
 701 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
 702                                           int datasize,
 703                                           struct dasd_device *device)
 704 {
 705         struct dasd_ccw_req *cqr;
 706
 707         /* Sanity checks */
 708         BUG_ON(datasize > PAGE_SIZE ||
 709              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 710
 711         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
 712         if (cqr == NULL)
 713                 return ERR_PTR(-ENOMEM);
 714         cqr->cpaddr = NULL;
 715         if (cplength > 0) {
 716                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 717                                       GFP_ATOMIC | GFP_DMA);
 718                 if (cqr->cpaddr == NULL) {
 719                         kfree(cqr);
 720                         return ERR_PTR(-ENOMEM);
 721                 }
 722         }
 723         cqr->data = NULL;
 724         if (datasize > 0) {
 725                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
 726                 if (cqr->data == NULL) {
 727                         kfree(cqr->cpaddr);
 728                         kfree(cqr);
 729                         return ERR_PTR(-ENOMEM);
 730                 }
 731         }
 732         cqr->magic =  magic;
 733         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 734         dasd_get_device(device);
 735         return cqr;
 736 }
 737
 738 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
 739                                           int datasize,
 740                                           struct dasd_device *device)
 741 {
 742         unsigned long flags;
 743         struct dasd_ccw_req *cqr;
 744         char *data;
 745         int size;
 746
 747         /* Sanity checks */
 748         BUG_ON(datasize > PAGE_SIZE ||
 749              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 750
 751         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
 752         if (cplength > 0)
 753                 size += cplength * sizeof(struct ccw1);
 754         if (datasize > 0)
 755                 size += datasize;
 756         spin_lock_irqsave(&device->mem_lock, flags);
 757         cqr = (struct dasd_ccw_req *)
 758                 dasd_alloc_chunk(&device->ccw_chunks, size);
 759         spin_unlock_irqrestore(&device->mem_lock, flags);
 760         if (cqr == NULL)
 761                 return ERR_PTR(-ENOMEM);
 762         memset(cqr, 0, sizeof(struct dasd_ccw_req));
 763         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
 764         cqr->cpaddr = NULL;
 765         if (cplength > 0) {
 766                 cqr->cpaddr = (struct ccw1 *) data;
 767                 data += cplength*sizeof(struct ccw1);
 768                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
 769         }
 770         cqr->data = NULL;
 771         if (datasize > 0) {
 772                 cqr->data = data;
 773                 memset(cqr->data, 0, datasize);
 774         }
 775         cqr->magic = magic;
 776         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 777         dasd_get_device(device);
 778         return cqr;
 779 }
 780
 781 /*
 782  * Free memory of a channel program. This function needs to free all the
 783  * idal lists that might have been created by dasd_set_cda and the
 784  * struct dasd_ccw_req itself.
 785  */
 786 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
 787 {
 788 #ifdef CONFIG_64BIT
 789         struct ccw1 *ccw;
 790
 791         /* Clear any idals used for the request. */
 792         ccw = cqr->cpaddr;
 793         do {
 794                 clear_normalized_cda(ccw);
 795         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
 796 #endif
 797         kfree(cqr->cpaddr);
 798         kfree(cqr->data);
 799         kfree(cqr);
 800         dasd_put_device(device);
 801 }
 802
 803 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
 804 {
 805         unsigned long flags;
 806
 807         spin_lock_irqsave(&device->mem_lock, flags);
 808         dasd_free_chunk(&device->ccw_chunks, cqr);
 809         spin_unlock_irqrestore(&device->mem_lock, flags);
 810         dasd_put_device(device);
 811 }
 812
 813 /*
 814  * Check discipline magic in cqr.
 815  */
 816 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
 817 {
 818         struct dasd_device *device;
 819
 820         if (cqr == NULL)
 821                 return -EINVAL;
 822         device = cqr->startdev;
 823         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
 824                 DBF_DEV_EVENT(DBF_WARNING, device,
 825                             " dasd_ccw_req 0x%08x magic doesn't match"
 826                             " discipline 0x%08x",
 827                             cqr->magic,
 828                             *(unsigned int *) device->discipline->name);
 829                 return -EINVAL;
 830         }
 831         return 0;
 832 }
 833
 834 /*
 835  * Terminate the current i/o and set the request to clear_pending.
 836  * Timer keeps device runnig.
 837  * ccw_device_clear can fail if the i/o subsystem
 838  * is in a bad mood.
 839  */
 840 int dasd_term_IO(struct dasd_ccw_req *cqr)
 841 {
 842         struct dasd_device *device;
 843         int retries, rc;
 844         char errorstring[ERRORLENGTH];
 845
 846         /* Check the cqr */
 847         rc = dasd_check_cqr(cqr);
 848         if (rc)
 849                 return rc;
 850         retries = 0;
 851         device = (struct dasd_device *) cqr->startdev;
 852         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
 853                 rc = ccw_device_clear(device->cdev, (long) cqr);
 854                 switch (rc) {
 855                 case 0: /* termination successful */
 856                         cqr->retries--;
 857                         cqr->status = DASD_CQR_CLEAR_PENDING;
 858                         cqr->stopclk = get_clock();
 859                         cqr->starttime = 0;
 860                         DBF_DEV_EVENT(DBF_DEBUG, device,
 861                                       "terminate cqr %p successful",
 862                                       cqr);
 863                         break;
 864                 case -ENODEV:
 865                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 866                                       "device gone, retry");
 867                         break;
 868                 case -EIO:
 869                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 870                                       "I/O error, retry");
 871                         break;
 872                 case -EINVAL:
 873                 case -EBUSY:
 874                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
 875                                       "device busy, retry later");
 876                         break;
 877                 default:
 878                         /* internal error 10 - unknown rc*/
 879                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
 880                         dev_err(&device->cdev->dev, "An error occurred in the "
 881                                 "DASD device driver, reason=%s\n", errorstring);
 882                         BUG();
 883                         break;
 884                 }
 885                 retries++;
 886         }
 887         dasd_schedule_device_bh(device);
 888         return rc;
 889 }
 890
 891 /*
 892  * Start the i/o. This start_IO can fail if the channel is really busy.
 893  * In that case set up a timer to start the request later.
 894  */
 895 int dasd_start_IO(struct dasd_ccw_req *cqr)
 896 {
 897         struct dasd_device *device;
 898         int rc;
 899         char errorstring[ERRORLENGTH];
 900
 901         /* Check the cqr */
 902         rc = dasd_check_cqr(cqr);
 903         if (rc) {
 904                 cqr->intrc = rc;
 905                 return rc;
 906         }
 907         device = (struct dasd_device *) cqr->startdev;
 908         if (cqr->retries < 0) {
 909                 /* internal error 14 - start_IO run out of retries */
 910                 sprintf(errorstring, "14 %p", cqr);
 911                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
 912                         "device driver, reason=%s\n", errorstring);
 913                 cqr->status = DASD_CQR_ERROR;
 914                 return -EIO;
 915         }
 916         cqr->startclk = get_clock();
 917         cqr->starttime = jiffies;
 918         cqr->retries--;
 919         if (cqr->cpmode == 1) {
 920                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
 921                                          (long) cqr, cqr->lpm);
 922         } else {
 923                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
 924                                       (long) cqr, cqr->lpm, 0);
 925         }
 926         switch (rc) {
 927         case 0:
 928                 cqr->status = DASD_CQR_IN_IO;
 929                 break;
 930         case -EBUSY:
 931                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 932                               "start_IO: device busy, retry later");
 933                 break;
 934         case -ETIMEDOUT:
 935                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 936                               "start_IO: request timeout, retry later");
 937                 break;
 938         case -EACCES:
 939                 /* -EACCES indicates that the request used only a
 940                  * subset of the available pathes and all these
 941                  * pathes are gone.
 942                  * Do a retry with all available pathes.
 943                  */
 944                 cqr->lpm = LPM_ANYPATH;
 945                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 946                               "start_IO: selected pathes gone,"
 947                               " retry on all pathes");
 948                 break;
 949         case -ENODEV:
 950                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 951                               "start_IO: -ENODEV device gone, retry");
 952                 break;
 953         case -EIO:
 954                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 955                               "start_IO: -EIO device gone, retry");
 956                 break;
 957         case -EINVAL:
 958                 /* most likely caused in power management context */
 959                 DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
 960                               "start_IO: -EINVAL device currently "
 961                               "not accessible");
 962                 break;
 963         default:
 964                 /* internal error 11 - unknown rc */
 965                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
 966                 dev_err(&device->cdev->dev,
 967                         "An error occurred in the DASD device driver, "
 968                         "reason=%s\n", errorstring);
 969                 BUG();
 970                 break;
 971         }
 972         cqr->intrc = rc;
 973         return rc;
 974 }
 975
 976 /*
 977  * Timeout function for dasd devices. This is used for different purposes
 978  *  1) missing interrupt handler for normal operation
 979  *  2) delayed start of request where start_IO failed with -EBUSY
 980  *  3) timeout for missing state change interrupts
 981  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 982  * DASD_CQR_QUEUED for 2) and 3).
 983  */
 984 static void dasd_device_timeout(unsigned long ptr)
 985 {
 986         unsigned long flags;
 987         struct dasd_device *device;
 988
 989         device = (struct dasd_device *) ptr;
 990         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 991         /* re-activate request queue */
 992         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
 993         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 994         dasd_schedule_device_bh(device);
 995 }
 996
 997 /*
 998  * Setup timeout for a device in jiffies.
 999  */
1000 void dasd_device_set_timer(struct dasd_device *device, int expires)
1001 {
1002         if (expires == 0)
1003                 del_timer(&device->timer);
1004         else
1005                 mod_timer(&device->timer, jiffies + expires);
1006 }
1007
1008 /*
1009  * Clear timeout for a device.
1010  */
1011 void dasd_device_clear_timer(struct dasd_device *device)
1012 {
1013         del_timer(&device->timer);
1014 }
1015
1016 static void dasd_handle_killed_request(struct ccw_device *cdev,
1017                                        unsigned long intparm)
1018 {
1019         struct dasd_ccw_req *cqr;
1020         struct dasd_device *device;
1021
1022         if (!intparm)
1023                 return;
1024         cqr = (struct dasd_ccw_req *) intparm;
1025         if (cqr->status != DASD_CQR_IN_IO) {
1026                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1027                                 "invalid status in handle_killed_request: "
1028                                 "%02x", cqr->status);
1029                 return;
1030         }
1031
1032         device = dasd_device_from_cdev_locked(cdev);
1033         if (IS_ERR(device)) {
1034                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1035                                 "unable to get device from cdev");
1036                 return;
1037         }
1038
1039         if (!cqr->startdev ||
1040             device != cqr->startdev ||
1041             strncmp(cqr->startdev->discipline->ebcname,
1042                     (char *) &cqr->magic, 4)) {
1043                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1044                                 "invalid device in request");
1045                 dasd_put_device(device);
1046                 return;
1047         }
1048
1049         /* Schedule request to be retried. */
1050         cqr->status = DASD_CQR_QUEUED;
1051
1052         dasd_device_clear_timer(device);
1053         dasd_schedule_device_bh(device);
1054         dasd_put_device(device);
1055 }
1056
1057 void dasd_generic_handle_state_change(struct dasd_device *device)
1058 {
1059         /* First of all start sense subsystem status request. */
1060         dasd_eer_snss(device);
1061
1062         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1063         dasd_schedule_device_bh(device);
1064         if (device->block)
1065                 dasd_schedule_block_bh(device->block);
1066 }
1067
1068 /*
1069  * Interrupt handler for "normal" ssch-io based dasd devices.
1070  */
1071 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1072                       struct irb *irb)
1073 {
1074         struct dasd_ccw_req *cqr, *next;
1075         struct dasd_device *device;
1076         unsigned long long now;
1077         int expires;
1078
1079         if (IS_ERR(irb)) {
1080                 switch (PTR_ERR(irb)) {
1081                 case -EIO:
1082                         break;
1083                 case -ETIMEDOUT:
1084                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1085                                         "request timed out\n", __func__);
1086                         break;
1087                 default:
1088                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1089                                         "unknown error %ld\n", __func__,
1090                                         PTR_ERR(irb));
1091                 }
1092                 dasd_handle_killed_request(cdev, intparm);
1093                 return;
1094         }
1095
1096         now = get_clock();
1097
1098         /* check for unsolicited interrupts */
1099         cqr = (struct dasd_ccw_req *) intparm;
1100         if (!cqr || ((scsw_cc(&irb->scsw) == 1) &&
1101                      (scsw_fctl(&irb->scsw) & SCSW_FCTL_START_FUNC) &&
1102                      (scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))) {
1103                 if (cqr && cqr->status == DASD_CQR_IN_IO)
1104                         cqr->status = DASD_CQR_QUEUED;
1105                 device = dasd_device_from_cdev_locked(cdev);
1106                 if (!IS_ERR(device)) {
1107                         dasd_device_clear_timer(device);
1108                         device->discipline->handle_unsolicited_interrupt(device,
1109                                                                          irb);
1110                         dasd_put_device(device);
1111                 }
1112                 return;
1113         }
1114
1115         device = (struct dasd_device *) cqr->startdev;
1116         if (!device ||
1117             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1118                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1119                                 "invalid device in request");
1120                 return;
1121         }
1122
1123         /* Check for clear pending */
1124         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1125             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1126                 cqr->status = DASD_CQR_CLEARED;
1127                 dasd_device_clear_timer(device);
1128                 wake_up(&dasd_flush_wq);
1129                 dasd_schedule_device_bh(device);
1130                 return;
1131         }
1132
1133         /* check status - the request might have been killed by dyn detach */
1134         if (cqr->status != DASD_CQR_IN_IO) {
1135                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1136                               "status %02x", dev_name(&cdev->dev), cqr->status);
1137                 return;
1138         }
1139
1140         next = NULL;
1141         expires = 0;
1142         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1143             scsw_cstat(&irb->scsw) == 0) {
1144                 /* request was completed successfully */
1145                 cqr->status = DASD_CQR_SUCCESS;
1146                 cqr->stopclk = now;
1147                 /* Start first request on queue if possible -> fast_io. */
1148                 if (cqr->devlist.next != &device->ccw_queue) {
1149                         next = list_entry(cqr->devlist.next,
1150                                           struct dasd_ccw_req, devlist);
1151                 }
1152         } else {  /* error */
1153                 memcpy(&cqr->irb, irb, sizeof(struct irb));
1154                 /* log sense for every failed I/O to s390 debugfeature */
1155                 dasd_log_sense_dbf(cqr, irb);
1156                 if (device->features & DASD_FEATURE_ERPLOG) {
1157                         dasd_log_sense(cqr, irb);
1158                 }
1159
1160                 /*
1161                  * If we don't want complex ERP for this request, then just
1162                  * reset this and retry it in the fastpath
1163                  */
1164                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1165                     cqr->retries > 0) {
1166                         if (cqr->lpm == LPM_ANYPATH)
1167                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1168                                               "default ERP in fastpath "
1169                                               "(%i retries left)",
1170                                               cqr->retries);
1171                         cqr->lpm    = LPM_ANYPATH;
1172                         cqr->status = DASD_CQR_QUEUED;
1173                         next = cqr;
1174                 } else
1175                         cqr->status = DASD_CQR_ERROR;
1176         }
1177         if (next && (next->status == DASD_CQR_QUEUED) &&
1178             (!device->stopped)) {
1179                 if (device->discipline->start_IO(next) == 0)
1180                         expires = next->expires;
1181         }
1182         if (expires != 0)
1183                 dasd_device_set_timer(device, expires);
1184         else
1185                 dasd_device_clear_timer(device);
1186         dasd_schedule_device_bh(device);
1187 }
1188
1189 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1190 {
1191         struct dasd_device *device;
1192
1193         device = dasd_device_from_cdev_locked(cdev);
1194
1195         if (IS_ERR(device))
1196                 goto out;
1197         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1198            device->state != device->target ||
1199            !device->discipline->handle_unsolicited_interrupt){
1200                 dasd_put_device(device);
1201                 goto out;
1202         }
1203
1204         dasd_device_clear_timer(device);
1205         device->discipline->handle_unsolicited_interrupt(device, irb);
1206         dasd_put_device(device);
1207 out:
1208         return UC_TODO_RETRY;
1209 }
1210 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1211
1212 /*
1213  * If we have an error on a dasd_block layer request then we cancel
1214  * and return all further requests from the same dasd_block as well.
1215  */
1216 static void __dasd_device_recovery(struct dasd_device *device,
1217                                    struct dasd_ccw_req *ref_cqr)
1218 {
1219         struct list_head *l, *n;
1220         struct dasd_ccw_req *cqr;
1221
1222         /*
1223          * only requeue request that came from the dasd_block layer
1224          */
1225         if (!ref_cqr->block)
1226                 return;
1227
1228         list_for_each_safe(l, n, &device->ccw_queue) {
1229                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1230                 if (cqr->status == DASD_CQR_QUEUED &&
1231                     ref_cqr->block == cqr->block) {
1232                         cqr->status = DASD_CQR_CLEARED;
1233                 }
1234         }
1235 };
1236
1237 /*
1238  * Remove those ccw requests from the queue that need to be returned
1239  * to the upper layer.
1240  */
1241 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1242                                             struct list_head *final_queue)
1243 {
1244         struct list_head *l, *n;
1245         struct dasd_ccw_req *cqr;
1246
1247         /* Process request with final status. */
1248         list_for_each_safe(l, n, &device->ccw_queue) {
1249                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1250
1251                 /* Stop list processing at the first non-final request. */
1252                 if (cqr->status == DASD_CQR_QUEUED ||
1253                     cqr->status == DASD_CQR_IN_IO ||
1254                     cqr->status == DASD_CQR_CLEAR_PENDING)
1255                         break;
1256                 if (cqr->status == DASD_CQR_ERROR) {
1257                         __dasd_device_recovery(device, cqr);
1258                 }
1259                 /* Rechain finished requests to final queue */
1260                 list_move_tail(&cqr->devlist, final_queue);
1261         }
1262 }
1263
1264 /*
1265  * the cqrs from the final queue are returned to the upper layer
1266  * by setting a dasd_block state and calling the callback function
1267  */
1268 static void __dasd_device_process_final_queue(struct dasd_device *device,
1269                                               struct list_head *final_queue)
1270 {
1271         struct list_head *l, *n;
1272         struct dasd_ccw_req *cqr;
1273         struct dasd_block *block;
1274         void (*callback)(struct dasd_ccw_req *, void *data);
1275         void *callback_data;
1276         char errorstring[ERRORLENGTH];
1277
1278         list_for_each_safe(l, n, final_queue) {
1279                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1280                 list_del_init(&cqr->devlist);
1281                 block = cqr->block;
1282                 callback = cqr->callback;
1283                 callback_data = cqr->callback_data;
1284                 if (block)
1285                         spin_lock_bh(&block->queue_lock);
1286                 switch (cqr->status) {
1287                 case DASD_CQR_SUCCESS:
1288                         cqr->status = DASD_CQR_DONE;
1289                         break;
1290                 case DASD_CQR_ERROR:
1291                         cqr->status = DASD_CQR_NEED_ERP;
1292                         break;
1293                 case DASD_CQR_CLEARED:
1294                         cqr->status = DASD_CQR_TERMINATED;
1295                         break;
1296                 default:
1297                         /* internal error 12 - wrong cqr status*/
1298                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1299                         dev_err(&device->cdev->dev,
1300                                 "An error occurred in the DASD device driver, "
1301                                 "reason=%s\n", errorstring);
1302                         BUG();
1303                 }
1304                 if (cqr->callback != NULL)
1305                         (callback)(cqr, callback_data);
1306                 if (block)
1307                         spin_unlock_bh(&block->queue_lock);
1308         }
1309 }
1310
1311 /*
1312  * Take a look at the first request on the ccw queue and check
1313  * if it reached its expire time. If so, terminate the IO.
1314  */
1315 static void __dasd_device_check_expire(struct dasd_device *device)
1316 {
1317         struct dasd_ccw_req *cqr;
1318
1319         if (list_empty(&device->ccw_queue))
1320                 return;
1321         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1322         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1323             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1324                 if (device->discipline->term_IO(cqr) != 0) {
1325                         /* Hmpf, try again in 5 sec */
1326                         dev_err(&device->cdev->dev,
1327                                 "cqr %p timed out (%is) but cannot be "
1328                                 "ended, retrying in 5 s\n",
1329                                 cqr, (cqr->expires/HZ));
1330                         cqr->expires += 5*HZ;
1331                         dasd_device_set_timer(device, 5*HZ);
1332                 } else {
1333                         dev_err(&device->cdev->dev,
1334                                 "cqr %p timed out (%is), %i retries "
1335                                 "remaining\n", cqr, (cqr->expires/HZ),
1336                                 cqr->retries);
1337                 }
1338         }
1339 }
1340
1341 /*
1342  * Take a look at the first request on the ccw queue and check
1343  * if it needs to be started.
1344  */
1345 static void __dasd_device_start_head(struct dasd_device *device)
1346 {
1347         struct dasd_ccw_req *cqr;
1348         int rc;
1349
1350         if (list_empty(&device->ccw_queue))
1351                 return;
1352         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1353         if (cqr->status != DASD_CQR_QUEUED)
1354                 return;
1355         /* when device is stopped, return request to previous layer */
1356         if (device->stopped) {
1357                 cqr->status = DASD_CQR_CLEARED;
1358                 dasd_schedule_device_bh(device);
1359                 return;
1360         }
1361
1362         rc = device->discipline->start_IO(cqr);
1363         if (rc == 0)
1364                 dasd_device_set_timer(device, cqr->expires);
1365         else if (rc == -EACCES) {
1366                 dasd_schedule_device_bh(device);
1367         } else
1368                 /* Hmpf, try again in 1/2 sec */
1369                 dasd_device_set_timer(device, 50);
1370 }
1371
1372 /*
1373  * Go through all request on the dasd_device request queue,
1374  * terminate them on the cdev if necessary, and return them to the
1375  * submitting layer via callback.
1376  * Note:
1377  * Make sure that all 'submitting layers' still exist when
1378  * this function is called!. In other words, when 'device' is a base
1379  * device then all block layer requests must have been removed before
1380  * via dasd_flush_block_queue.
1381  */
1382 int dasd_flush_device_queue(struct dasd_device *device)
1383 {
1384         struct dasd_ccw_req *cqr, *n;
1385         int rc;
1386         struct list_head flush_queue;
1387
1388         INIT_LIST_HEAD(&flush_queue);
1389         spin_lock_irq(get_ccwdev_lock(device->cdev));
1390         rc = 0;
1391         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1392                 /* Check status and move request to flush_queue */
1393                 switch (cqr->status) {
1394                 case DASD_CQR_IN_IO:
1395                         rc = device->discipline->term_IO(cqr);
1396                         if (rc) {
1397                                 /* unable to terminate requeust */
1398                                 dev_err(&device->cdev->dev,
1399                                         "Flushing the DASD request queue "
1400                                         "failed for request %p\n", cqr);
1401                                 /* stop flush processing */
1402                                 goto finished;
1403                         }
1404                         break;
1405                 case DASD_CQR_QUEUED:
1406                         cqr->stopclk = get_clock();
1407                         cqr->status = DASD_CQR_CLEARED;
1408                         break;
1409                 default: /* no need to modify the others */
1410                         break;
1411                 }
1412                 list_move_tail(&cqr->devlist, &flush_queue);
1413         }
1414 finished:
1415         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1416         /*
1417          * After this point all requests must be in state CLEAR_PENDING,
1418          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1419          * one of the others.
1420          */
1421         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1422                 wait_event(dasd_flush_wq,
1423                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1424         /*
1425          * Now set each request back to TERMINATED, DONE or NEED_ERP
1426          * and call the callback function of flushed requests
1427          */
1428         __dasd_device_process_final_queue(device, &flush_queue);
1429         return rc;
1430 }
1431
1432 /*
1433  * Acquire the device lock and process queues for the device.
1434  */
1435 static void dasd_device_tasklet(struct dasd_device *device)
1436 {
1437         struct list_head final_queue;
1438
1439         atomic_set (&device->tasklet_scheduled, 0);
1440         INIT_LIST_HEAD(&final_queue);
1441         spin_lock_irq(get_ccwdev_lock(device->cdev));
1442         /* Check expire time of first request on the ccw queue. */
1443         __dasd_device_check_expire(device);
1444         /* find final requests on ccw queue */
1445         __dasd_device_process_ccw_queue(device, &final_queue);
1446         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1447         /* Now call the callback function of requests with final status */
1448         __dasd_device_process_final_queue(device, &final_queue);
1449         spin_lock_irq(get_ccwdev_lock(device->cdev));
1450         /* Now check if the head of the ccw queue needs to be started. */
1451         __dasd_device_start_head(device);
1452         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1453         dasd_put_device(device);
1454 }
1455
1456 /*
1457  * Schedules a call to dasd_tasklet over the device tasklet.
1458  */
1459 void dasd_schedule_device_bh(struct dasd_device *device)
1460 {
1461         /* Protect against rescheduling. */
1462         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1463                 return;
1464         dasd_get_device(device);
1465         tasklet_hi_schedule(&device->tasklet);
1466 }
1467
1468 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
1469 {
1470         device->stopped |= bits;
1471 }
1472 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
1473
1474 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
1475 {
1476         device->stopped &= ~bits;
1477         if (!device->stopped)
1478                 wake_up(&generic_waitq);
1479 }
1480 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
1481
1482 /*
1483  * Queue a request to the head of the device ccw_queue.
1484  * Start the I/O if possible.
1485  */
1486 void dasd_add_request_head(struct dasd_ccw_req *cqr)
1487 {
1488         struct dasd_device *device;
1489         unsigned long flags;
1490
1491         device = cqr->startdev;
1492         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1493         cqr->status = DASD_CQR_QUEUED;
1494         list_add(&cqr->devlist, &device->ccw_queue);
1495         /* let the bh start the request to keep them in order */
1496         dasd_schedule_device_bh(device);
1497         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1498 }
1499
1500 /*
1501  * Queue a request to the tail of the device ccw_queue.
1502  * Start the I/O if possible.
1503  */
1504 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
1505 {
1506         struct dasd_device *device;
1507         unsigned long flags;
1508
1509         device = cqr->startdev;
1510         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1511         cqr->status = DASD_CQR_QUEUED;
1512         list_add_tail(&cqr->devlist, &device->ccw_queue);
1513         /* let the bh start the request to keep them in order */
1514         dasd_schedule_device_bh(device);
1515         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1516 }
1517
1518 /*
1519  * Wakeup helper for the 'sleep_on' functions.
1520  */
1521 static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1522 {
1523         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
1524         cqr->callback_data = DASD_SLEEPON_END_TAG;
1525         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
1526         wake_up(&generic_waitq);
1527 }
1528
1529 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
1530 {
1531         struct dasd_device *device;
1532         int rc;
1533
1534         device = cqr->startdev;
1535         spin_lock_irq(get_ccwdev_lock(device->cdev));
1536         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
1537         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1538         return rc;
1539 }
1540
1541 /*
1542  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
1543  */
1544 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
1545 {
1546         struct dasd_device *device;
1547         dasd_erp_fn_t erp_fn;
1548
1549         if (cqr->status == DASD_CQR_FILLED)
1550                 return 0;
1551         device = cqr->startdev;
1552         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
1553                 if (cqr->status == DASD_CQR_TERMINATED) {
1554                         device->discipline->handle_terminated_request(cqr);
1555                         return 1;
1556                 }
1557                 if (cqr->status == DASD_CQR_NEED_ERP) {
1558                         erp_fn = device->discipline->erp_action(cqr);
1559                         erp_fn(cqr);
1560                         return 1;
1561                 }
1562                 if (cqr->status == DASD_CQR_FAILED)
1563                         dasd_log_sense(cqr, &cqr->irb);
1564                 if (cqr->refers) {
1565                         __dasd_process_erp(device, cqr);
1566                         return 1;
1567                 }
1568         }
1569         return 0;
1570 }
1571
1572 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
1573 {
1574         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
1575                 if (cqr->refers) /* erp is not done yet */
1576                         return 1;
1577                 return ((cqr->status != DASD_CQR_DONE) &&
1578                         (cqr->status != DASD_CQR_FAILED));
1579         } else
1580                 return (cqr->status == DASD_CQR_FILLED);
1581 }
1582
1583 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
1584 {
1585         struct dasd_device *device;
1586         int rc;
1587         struct list_head ccw_queue;
1588         struct dasd_ccw_req *cqr;
1589
1590         INIT_LIST_HEAD(&ccw_queue);
1591         maincqr->status = DASD_CQR_FILLED;
1592         device = maincqr->startdev;
1593         list_add(&maincqr->blocklist, &ccw_queue);
1594         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
1595              cqr = list_first_entry(&ccw_queue,
1596                                     struct dasd_ccw_req, blocklist)) {
1597
1598                 if (__dasd_sleep_on_erp(cqr))
1599                         continue;
1600                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
1601                         continue;
1602
1603                 /* Non-temporary stop condition will trigger fail fast */
1604                 if (device->stopped & ~DASD_STOPPED_PENDING &&
1605                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1606                     (!dasd_eer_enabled(device))) {
1607                         cqr->status = DASD_CQR_FAILED;
1608                         continue;
1609                 }
1610
1611                 /* Don't try to start requests if device is stopped */
1612                 if (interruptible) {
1613                         rc = wait_event_interruptible(
1614                                 generic_waitq, !(device->stopped));
1615                         if (rc == -ERESTARTSYS) {
1616                                 cqr->status = DASD_CQR_FAILED;
1617                                 maincqr->intrc = rc;
1618                                 continue;
1619                         }
1620                 } else
1621                         wait_event(generic_waitq, !(device->stopped));
1622
1623                 cqr->callback = dasd_wakeup_cb;
1624                 cqr->callback_data = DASD_SLEEPON_START_TAG;
1625                 dasd_add_request_tail(cqr);
1626                 if (interruptible) {
1627                         rc = wait_event_interruptible(
1628                                 generic_waitq, _wait_for_wakeup(cqr));
1629                         if (rc == -ERESTARTSYS) {
1630                                 dasd_cancel_req(cqr);
1631                                 /* wait (non-interruptible) for final status */
1632                                 wait_event(generic_waitq,
1633                                            _wait_for_wakeup(cqr));
1634                                 cqr->status = DASD_CQR_FAILED;
1635                                 maincqr->intrc = rc;
1636                                 continue;
1637                         }
1638                 } else
1639                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
1640         }
1641
1642         maincqr->endclk = get_clock();
1643         if ((maincqr->status != DASD_CQR_DONE) &&
1644             (maincqr->intrc != -ERESTARTSYS))
1645                 dasd_log_sense(maincqr, &maincqr->irb);
1646         if (maincqr->status == DASD_CQR_DONE)
1647                 rc = 0;
1648         else if (maincqr->intrc)
1649                 rc = maincqr->intrc;
1650         else
1651                 rc = -EIO;
1652         return rc;
1653 }
1654
1655 /*
1656  * Queue a request to the tail of the device ccw_queue and wait for
1657  * it's completion.
1658  */
1659 int dasd_sleep_on(struct dasd_ccw_req *cqr)
1660 {
1661         return _dasd_sleep_on(cqr, 0);
1662 }
1663
1664 /*
1665  * Queue a request to the tail of the device ccw_queue and wait
1666  * interruptible for it's completion.
1667  */
1668 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
1669 {
1670         return _dasd_sleep_on(cqr, 1);
1671 }
1672
1673 /*
1674  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1675  * for eckd devices) the currently running request has to be terminated
1676  * and be put back to status queued, before the special request is added
1677  * to the head of the queue. Then the special request is waited on normally.
1678  */
1679 static inline int _dasd_term_running_cqr(struct dasd_device *device)
1680 {
1681         struct dasd_ccw_req *cqr;
1682
1683         if (list_empty(&device->ccw_queue))
1684                 return 0;
1685         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1686         return device->discipline->term_IO(cqr);
1687 }
1688
1689 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
1690 {
1691         struct dasd_device *device;
1692         int rc;
1693
1694         device = cqr->startdev;
1695         spin_lock_irq(get_ccwdev_lock(device->cdev));
1696         rc = _dasd_term_running_cqr(device);
1697         if (rc) {
1698                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1699                 return rc;
1700         }
1701
1702         cqr->callback = dasd_wakeup_cb;
1703         cqr->callback_data = DASD_SLEEPON_START_TAG;
1704         cqr->status = DASD_CQR_QUEUED;
1705         list_add(&cqr->devlist, &device->ccw_queue);
1706
1707         /* let the bh start the request to keep them in order */
1708         dasd_schedule_device_bh(device);
1709
1710         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1711
1712         wait_event(generic_waitq, _wait_for_wakeup(cqr));
1713
1714         if (cqr->status == DASD_CQR_DONE)
1715                 rc = 0;
1716         else if (cqr->intrc)
1717                 rc = cqr->intrc;
1718         else
1719                 rc = -EIO;
1720         return rc;
1721 }
1722
1723 /*
1724  * Cancels a request that was started with dasd_sleep_on_req.
1725  * This is useful to timeout requests. The request will be
1726  * terminated if it is currently in i/o.
1727  * Returns 1 if the request has been terminated.
1728  *         0 if there was no need to terminate the request (not started yet)
1729  *         negative error code if termination failed
1730  * Cancellation of a request is an asynchronous operation! The calling
1731  * function has to wait until the request is properly returned via callback.
1732  */
1733 int dasd_cancel_req(struct dasd_ccw_req *cqr)
1734 {
1735         struct dasd_device *device = cqr->startdev;
1736         unsigned long flags;
1737         int rc;
1738
1739         rc = 0;
1740         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1741         switch (cqr->status) {
1742         case DASD_CQR_QUEUED:
1743                 /* request was not started - just set to cleared */
1744                 cqr->status = DASD_CQR_CLEARED;
1745                 break;
1746         case DASD_CQR_IN_IO:
1747                 /* request in IO - terminate IO and release again */
1748                 rc = device->discipline->term_IO(cqr);
1749                 if (rc) {
1750                         dev_err(&device->cdev->dev,
1751                                 "Cancelling request %p failed with rc=%d\n",
1752                                 cqr, rc);
1753                 } else {
1754                         cqr->stopclk = get_clock();
1755                 }
1756                 break;
1757         default: /* already finished or clear pending - do nothing */
1758                 break;
1759         }
1760         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1761         dasd_schedule_device_bh(device);
1762         return rc;
1763 }
1764
1765
1766 /*
1767  * SECTION: Operations of the dasd_block layer.
1768  */
1769
1770 /*
1771  * Timeout function for dasd_block. This is used when the block layer
1772  * is waiting for something that may not come reliably, (e.g. a state
1773  * change interrupt)
1774  */
1775 static void dasd_block_timeout(unsigned long ptr)
1776 {
1777         unsigned long flags;
1778         struct dasd_block *block;
1779
1780         block = (struct dasd_block *) ptr;
1781         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
1782         /* re-activate request queue */
1783         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
1784         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
1785         dasd_schedule_block_bh(block);
1786 }
1787
1788 /*
1789  * Setup timeout for a dasd_block in jiffies.
1790  */
1791 void dasd_block_set_timer(struct dasd_block *block, int expires)
1792 {
1793         if (expires == 0)
1794                 del_timer(&block->timer);
1795         else
1796                 mod_timer(&block->timer, jiffies + expires);
1797 }
1798
1799 /*
1800  * Clear timeout for a dasd_block.
1801  */
1802 void dasd_block_clear_timer(struct dasd_block *block)
1803 {
1804         del_timer(&block->timer);
1805 }
1806
1807 /*
1808  * Process finished error recovery ccw.
1809  */
1810 static void __dasd_process_erp(struct dasd_device *device,
1811                                struct dasd_ccw_req *cqr)
1812 {
1813         dasd_erp_fn_t erp_fn;
1814
1815         if (cqr->status == DASD_CQR_DONE)
1816                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1817         else
1818                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
1819         erp_fn = device->discipline->erp_postaction(cqr);
1820         erp_fn(cqr);
1821 }
1822
1823 /*
1824  * Fetch requests from the block device queue.
1825  */
1826 static void __dasd_process_request_queue(struct dasd_block *block)
1827 {
1828         struct request_queue *queue;
1829         struct request *req;
1830         struct dasd_ccw_req *cqr;
1831         struct dasd_device *basedev;
1832         unsigned long flags;
1833         queue = block->request_queue;
1834         basedev = block->base;
1835         /* No queue ? Then there is nothing to do. */
1836         if (queue == NULL)
1837                 return;
1838
1839         /*
1840          * We requeue request from the block device queue to the ccw
1841          * queue only in two states. In state DASD_STATE_READY the
1842          * partition detection is done and we need to requeue requests
1843          * for that. State DASD_STATE_ONLINE is normal block device
1844          * operation.
1845          */
1846         if (basedev->state < DASD_STATE_READY) {
1847                 while ((req = blk_fetch_request(block->request_queue)))
1848                         __blk_end_request_all(req, -EIO);
1849                 return;
1850         }
1851         /* Now we try to fetch requests from the request queue */
1852         while (!blk_queue_plugged(queue) && (req = blk_peek_request(queue))) {
1853                 if (basedev->features & DASD_FEATURE_READONLY &&
1854                     rq_data_dir(req) == WRITE) {
1855                         DBF_DEV_EVENT(DBF_ERR, basedev,
1856                                       "Rejecting write request %p",
1857                                       req);
1858                         blk_start_request(req);
1859                         __blk_end_request_all(req, -EIO);
1860                         continue;
1861                 }
1862                 cqr = basedev->discipline->build_cp(basedev, block, req);
1863                 if (IS_ERR(cqr)) {
1864                         if (PTR_ERR(cqr) == -EBUSY)
1865                                 break;  /* normal end condition */
1866                         if (PTR_ERR(cqr) == -ENOMEM)
1867                                 break;  /* terminate request queue loop */
1868                         if (PTR_ERR(cqr) == -EAGAIN) {
1869                                 /*
1870                                  * The current request cannot be build right
1871                                  * now, we have to try later. If this request
1872                                  * is the head-of-queue we stop the device
1873                                  * for 1/2 second.
1874                                  */
1875                                 if (!list_empty(&block->ccw_queue))
1876                                         break;
1877                                 spin_lock_irqsave(
1878                                         get_ccwdev_lock(basedev->cdev), flags);
1879                                 dasd_device_set_stop_bits(basedev,
1880                                                           DASD_STOPPED_PENDING);
1881                                 spin_unlock_irqrestore(
1882                                         get_ccwdev_lock(basedev->cdev), flags);
1883                                 dasd_block_set_timer(block, HZ/2);
1884                                 break;
1885                         }
1886                         DBF_DEV_EVENT(DBF_ERR, basedev,
1887                                       "CCW creation failed (rc=%ld) "
1888                                       "on request %p",
1889                                       PTR_ERR(cqr), req);
1890                         blk_start_request(req);
1891                         __blk_end_request_all(req, -EIO);
1892                         continue;
1893                 }
1894                 /*
1895                  *  Note: callback is set to dasd_return_cqr_cb in
1896                  * __dasd_block_start_head to cover erp requests as well
1897                  */
1898                 cqr->callback_data = (void *) req;
1899                 cqr->status = DASD_CQR_FILLED;
1900                 blk_start_request(req);
1901                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
1902                 dasd_profile_start(block, cqr, req);
1903         }
1904 }
1905
1906 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
1907 {
1908         struct request *req;
1909         int status;
1910         int error = 0;
1911
1912         req = (struct request *) cqr->callback_data;
1913         dasd_profile_end(cqr->block, cqr, req);
1914         status = cqr->block->base->discipline->free_cp(cqr, req);
1915         if (status <= 0)
1916                 error = status ? status : -EIO;
1917         __blk_end_request_all(req, error);
1918 }
1919
1920 /*
1921  * Process ccw request queue.
1922  */
1923 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
1924                                            struct list_head *final_queue)
1925 {
1926         struct list_head *l, *n;
1927         struct dasd_ccw_req *cqr;
1928         dasd_erp_fn_t erp_fn;
1929         unsigned long flags;
1930         struct dasd_device *base = block->base;
1931
1932 restart:
1933         /* Process request with final status. */
1934         list_for_each_safe(l, n, &block->ccw_queue) {
1935                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
1936                 if (cqr->status != DASD_CQR_DONE &&
1937                     cqr->status != DASD_CQR_FAILED &&
1938                     cqr->status != DASD_CQR_NEED_ERP &&
1939                     cqr->status != DASD_CQR_TERMINATED)
1940                         continue;
1941
1942                 if (cqr->status == DASD_CQR_TERMINATED) {
1943                         base->discipline->handle_terminated_request(cqr);
1944                         goto restart;
1945                 }
1946
1947                 /*  Process requests that may be recovered */
1948                 if (cqr->status == DASD_CQR_NEED_ERP) {
1949                         erp_fn = base->discipline->erp_action(cqr);
1950                         if (IS_ERR(erp_fn(cqr)))
1951                                 continue;
1952                         goto restart;
1953                 }
1954
1955                 /* log sense for fatal error */
1956                 if (cqr->status == DASD_CQR_FAILED) {
1957                         dasd_log_sense(cqr, &cqr->irb);
1958                 }
1959
1960                 /* First of all call extended error reporting. */
1961                 if (dasd_eer_enabled(base) &&
1962                     cqr->status == DASD_CQR_FAILED) {
1963                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
1964
1965                         /* restart request  */
1966                         cqr->status = DASD_CQR_FILLED;
1967                         cqr->retries = 255;
1968                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
1969                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
1970                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
1971                                                flags);
1972                         goto restart;
1973                 }
1974
1975                 /* Process finished ERP request. */
1976                 if (cqr->refers) {
1977                         __dasd_process_erp(base, cqr);
1978                         goto restart;
1979                 }
1980
1981                 /* Rechain finished requests to final queue */
1982                 cqr->endclk = get_clock();
1983                 list_move_tail(&cqr->blocklist, final_queue);
1984         }
1985 }
1986
1987 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
1988 {
1989         dasd_schedule_block_bh(cqr->block);
1990 }
1991
1992 static void __dasd_block_start_head(struct dasd_block *block)
1993 {
1994         struct dasd_ccw_req *cqr;
1995
1996         if (list_empty(&block->ccw_queue))
1997                 return;
1998         /* We allways begin with the first requests on the queue, as some
1999          * of previously started requests have to be enqueued on a
2000          * dasd_device again for error recovery.
2001          */
2002         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2003                 if (cqr->status != DASD_CQR_FILLED)
2004                         continue;
2005                 /* Non-temporary stop condition will trigger fail fast */
2006                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2007                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2008                     (!dasd_eer_enabled(block->base))) {
2009                         cqr->status = DASD_CQR_FAILED;
2010                         dasd_schedule_block_bh(block);
2011                         continue;
2012                 }
2013                 /* Don't try to start requests if device is stopped */
2014                 if (block->base->stopped)
2015                         return;
2016
2017                 /* just a fail safe check, should not happen */
2018                 if (!cqr->startdev)
2019                         cqr->startdev = block->base;
2020
2021                 /* make sure that the requests we submit find their way back */
2022                 cqr->callback = dasd_return_cqr_cb;
2023
2024                 dasd_add_request_tail(cqr);
2025         }
2026 }
2027
2028 /*
2029  * Central dasd_block layer routine. Takes requests from the generic
2030  * block layer request queue, creates ccw requests, enqueues them on
2031  * a dasd_device and processes ccw requests that have been returned.
2032  */
2033 static void dasd_block_tasklet(struct dasd_block *block)
2034 {
2035         struct list_head final_queue;
2036         struct list_head *l, *n;
2037         struct dasd_ccw_req *cqr;
2038
2039         atomic_set(&block->tasklet_scheduled, 0);
2040         INIT_LIST_HEAD(&final_queue);
2041         spin_lock(&block->queue_lock);
2042         /* Finish off requests on ccw queue */
2043         __dasd_process_block_ccw_queue(block, &final_queue);
2044         spin_unlock(&block->queue_lock);
2045         /* Now call the callback function of requests with final status */
2046         spin_lock_irq(&block->request_queue_lock);
2047         list_for_each_safe(l, n, &final_queue) {
2048                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2049                 list_del_init(&cqr->blocklist);
2050                 __dasd_cleanup_cqr(cqr);
2051         }
2052         spin_lock(&block->queue_lock);
2053         /* Get new request from the block device request queue */
2054         __dasd_process_request_queue(block);
2055         /* Now check if the head of the ccw queue needs to be started. */
2056         __dasd_block_start_head(block);
2057         spin_unlock(&block->queue_lock);
2058         spin_unlock_irq(&block->request_queue_lock);
2059         dasd_put_device(block->base);
2060 }
2061
2062 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2063 {
2064         wake_up(&dasd_flush_wq);
2065 }
2066
2067 /*
2068  * Go through all request on the dasd_block request queue, cancel them
2069  * on the respective dasd_device, and return them to the generic
2070  * block layer.
2071  */
2072 static int dasd_flush_block_queue(struct dasd_block *block)
2073 {
2074         struct dasd_ccw_req *cqr, *n;
2075         int rc, i;
2076         struct list_head flush_queue;
2077
2078         INIT_LIST_HEAD(&flush_queue);
2079         spin_lock_bh(&block->queue_lock);
2080         rc = 0;
2081 restart:
2082         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2083                 /* if this request currently owned by a dasd_device cancel it */
2084                 if (cqr->status >= DASD_CQR_QUEUED)
2085                         rc = dasd_cancel_req(cqr);
2086                 if (rc < 0)
2087                         break;
2088                 /* Rechain request (including erp chain) so it won't be
2089                  * touched by the dasd_block_tasklet anymore.
2090                  * Replace the callback so we notice when the request
2091                  * is returned from the dasd_device layer.
2092                  */
2093                 cqr->callback = _dasd_wake_block_flush_cb;
2094                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2095                         list_move_tail(&cqr->blocklist, &flush_queue);
2096                 if (i > 1)
2097                         /* moved more than one request - need to restart */
2098                         goto restart;
2099         }
2100         spin_unlock_bh(&block->queue_lock);
2101         /* Now call the callback function of flushed requests */
2102 restart_cb:
2103         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2104                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2105                 /* Process finished ERP request. */
2106                 if (cqr->refers) {
2107                         spin_lock_bh(&block->queue_lock);
2108                         __dasd_process_erp(block->base, cqr);
2109                         spin_unlock_bh(&block->queue_lock);
2110                         /* restart list_for_xx loop since dasd_process_erp
2111                          * might remove multiple elements */
2112                         goto restart_cb;
2113                 }
2114                 /* call the callback function */
2115                 spin_lock_irq(&block->request_queue_lock);
2116                 cqr->endclk = get_clock();
2117                 list_del_init(&cqr->blocklist);
2118                 __dasd_cleanup_cqr(cqr);
2119                 spin_unlock_irq(&block->request_queue_lock);
2120         }
2121         return rc;
2122 }
2123
2124 /*
2125  * Schedules a call to dasd_tasklet over the device tasklet.
2126  */
2127 void dasd_schedule_block_bh(struct dasd_block *block)
2128 {
2129         /* Protect against rescheduling. */
2130         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2131                 return;
2132         /* life cycle of block is bound to it's base device */
2133         dasd_get_device(block->base);
2134         tasklet_hi_schedule(&block->tasklet);
2135 }
2136
2137
2138 /*
2139  * SECTION: external block device operations
2140  * (request queue handling, open, release, etc.)
2141  */
2142
2143 /*
2144  * Dasd request queue function. Called from ll_rw_blk.c
2145  */
2146 static void do_dasd_request(struct request_queue *queue)
2147 {
2148         struct dasd_block *block;
2149
2150         block = queue->queuedata;
2151         spin_lock(&block->queue_lock);
2152         /* Get new request from the block device request queue */
2153         __dasd_process_request_queue(block);
2154         /* Now check if the head of the ccw queue needs to be started. */
2155         __dasd_block_start_head(block);
2156         spin_unlock(&block->queue_lock);
2157 }
2158
2159 /*
2160  * Allocate and initialize request queue and default I/O scheduler.
2161  */
2162 static int dasd_alloc_queue(struct dasd_block *block)
2163 {
2164         int rc;
2165
2166         block->request_queue = blk_init_queue(do_dasd_request,
2167                                                &block->request_queue_lock);
2168         if (block->request_queue == NULL)
2169                 return -ENOMEM;
2170
2171         block->request_queue->queuedata = block;
2172
2173         elevator_exit(block->request_queue->elevator);
2174         block->request_queue->elevator = NULL;
2175         rc = elevator_init(block->request_queue, "deadline");
2176         if (rc) {
2177                 blk_cleanup_queue(block->request_queue);
2178                 return rc;
2179         }
2180         return 0;
2181 }
2182
2183 /*
2184  * Allocate and initialize request queue.
2185  */
2186 static void dasd_setup_queue(struct dasd_block *block)
2187 {
2188         int max;
2189
2190         blk_queue_logical_block_size(block->request_queue, block->bp_block);
2191         max = block->base->discipline->max_blocks << block->s2b_shift;
2192         blk_queue_max_hw_sectors(block->request_queue, max);
2193         blk_queue_max_segments(block->request_queue, -1L);
2194         /* with page sized segments we can translate each segement into
2195          * one idaw/tidaw
2196          */
2197         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
2198         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
2199         blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN, NULL);
2200 }
2201
2202 /*
2203  * Deactivate and free request queue.
2204  */
2205 static void dasd_free_queue(struct dasd_block *block)
2206 {
2207         if (block->request_queue) {
2208                 blk_cleanup_queue(block->request_queue);
2209                 block->request_queue = NULL;
2210         }
2211 }
2212
2213 /*
2214  * Flush request on the request queue.
2215  */
2216 static void dasd_flush_request_queue(struct dasd_block *block)
2217 {
2218         struct request *req;
2219
2220         if (!block->request_queue)
2221                 return;
2222
2223         spin_lock_irq(&block->request_queue_lock);
2224         while ((req = blk_fetch_request(block->request_queue)))
2225                 __blk_end_request_all(req, -EIO);
2226         spin_unlock_irq(&block->request_queue_lock);
2227 }
2228
2229 static int dasd_open(struct block_device *bdev, fmode_t mode)
2230 {
2231         struct dasd_block *block = bdev->bd_disk->private_data;
2232         struct dasd_device *base;
2233         int rc;
2234
2235         if (!block)
2236                 return -ENODEV;
2237
2238         base = block->base;
2239         atomic_inc(&block->open_count);
2240         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
2241                 rc = -ENODEV;
2242                 goto unlock;
2243         }
2244
2245         if (!try_module_get(base->discipline->owner)) {
2246                 rc = -EINVAL;
2247                 goto unlock;
2248         }
2249
2250         if (dasd_probeonly) {
2251                 dev_info(&base->cdev->dev,
2252                          "Accessing the DASD failed because it is in "
2253                          "probeonly mode\n");
2254                 rc = -EPERM;
2255                 goto out;
2256         }
2257
2258         if (base->state <= DASD_STATE_BASIC) {
2259                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
2260                               " Cannot open unrecognized device");
2261                 rc = -ENODEV;
2262                 goto out;
2263         }
2264
2265         if ((mode & FMODE_WRITE) &&
2266             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
2267              (base->features & DASD_FEATURE_READONLY))) {
2268                 rc = -EROFS;
2269                 goto out;
2270         }
2271
2272         return 0;
2273
2274 out:
2275         module_put(base->discipline->owner);
2276 unlock:
2277         atomic_dec(&block->open_count);
2278         return rc;
2279 }
2280
2281 static int dasd_release(struct gendisk *disk, fmode_t mode)
2282 {
2283         struct dasd_block *block = disk->private_data;
2284
2285         atomic_dec(&block->open_count);
2286         module_put(block->base->discipline->owner);
2287         return 0;
2288 }
2289
2290 /*
2291  * Return disk geometry.
2292  */
2293 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2294 {
2295         struct dasd_block *block;
2296         struct dasd_device *base;
2297
2298         block = bdev->bd_disk->private_data;
2299         if (!block)
2300                 return -ENODEV;
2301         base = block->base;
2302
2303         if (!base->discipline ||
2304             !base->discipline->fill_geometry)
2305                 return -EINVAL;
2306
2307         base->discipline->fill_geometry(block, geo);
2308         geo->start = get_start_sect(bdev) >> block->s2b_shift;
2309         return 0;
2310 }
2311
2312 const struct block_device_operations
2313 dasd_device_operations = {
2314         .owner          = THIS_MODULE,
2315         .open           = dasd_open,
2316         .release        = dasd_release,
2317         .ioctl          = dasd_ioctl,
2318         .compat_ioctl   = dasd_ioctl,
2319         .getgeo         = dasd_getgeo,
2320 };
2321
2322 /*******************************************************************************
2323  * end of block device operations
2324  */
2325
2326 static void
2327 dasd_exit(void)
2328 {
2329 #ifdef CONFIG_PROC_FS
2330         dasd_proc_exit();
2331 #endif
2332         dasd_eer_exit();
2333         if (dasd_page_cache != NULL) {
2334                 kmem_cache_destroy(dasd_page_cache);
2335                 dasd_page_cache = NULL;
2336         }
2337         dasd_gendisk_exit();
2338         dasd_devmap_exit();
2339         if (dasd_debug_area != NULL) {
2340                 debug_unregister(dasd_debug_area);
2341                 dasd_debug_area = NULL;
2342         }
2343 }
2344
2345 /*
2346  * SECTION: common functions for ccw_driver use
2347  */
2348
2349 /*
2350  * Is the device read-only?
2351  * Note that this function does not report the setting of the
2352  * readonly device attribute, but how it is configured in z/VM.
2353  */
2354 int dasd_device_is_ro(struct dasd_device *device)
2355 {
2356         struct ccw_dev_id dev_id;
2357         struct diag210 diag_data;
2358         int rc;
2359
2360         if (!MACHINE_IS_VM)
2361                 return 0;
2362         ccw_device_get_id(device->cdev, &dev_id);
2363         memset(&diag_data, 0, sizeof(diag_data));
2364         diag_data.vrdcdvno = dev_id.devno;
2365         diag_data.vrdclen = sizeof(diag_data);
2366         rc = diag210(&diag_data);
2367         if (rc == 0 || rc == 2) {
2368                 return diag_data.vrdcvfla & 0x80;
2369         } else {
2370                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
2371                           dev_id.devno, rc);
2372                 return 0;
2373         }
2374 }
2375 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
2376
2377 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
2378 {
2379         struct ccw_device *cdev = data;
2380         int ret;
2381
2382         ret = ccw_device_set_online(cdev);
2383         if (ret)
2384                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
2385                            dev_name(&cdev->dev), ret);
2386 }
2387
2388 /*
2389  * Initial attempt at a probe function. this can be simplified once
2390  * the other detection code is gone.
2391  */
2392 int dasd_generic_probe(struct ccw_device *cdev,
2393                        struct dasd_discipline *discipline)
2394 {
2395         int ret;
2396
2397         ret = dasd_add_sysfs_files(cdev);
2398         if (ret) {
2399                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
2400                                 "dasd_generic_probe: could not add "
2401                                 "sysfs entries");
2402                 return ret;
2403         }
2404         cdev->handler = &dasd_int_handler;
2405
2406         /*
2407          * Automatically online either all dasd devices (dasd_autodetect)
2408          * or all devices specified with dasd= parameters during
2409          * initial probe.
2410          */
2411         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
2412             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
2413                 async_schedule(dasd_generic_auto_online, cdev);
2414         return 0;
2415 }
2416
2417 /*
2418  * This will one day be called from a global not_oper handler.
2419  * It is also used by driver_unregister during module unload.
2420  */
2421 void dasd_generic_remove(struct ccw_device *cdev)
2422 {
2423         struct dasd_device *device;
2424         struct dasd_block *block;
2425
2426         cdev->handler = NULL;
2427
2428         dasd_remove_sysfs_files(cdev);
2429         device = dasd_device_from_cdev(cdev);
2430         if (IS_ERR(device))
2431                 return;
2432         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2433                 /* Already doing offline processing */
2434                 dasd_put_device(device);
2435                 return;
2436         }
2437         /*
2438          * This device is removed unconditionally. Set offline
2439          * flag to prevent dasd_open from opening it while it is
2440          * no quite down yet.
2441          */
2442         dasd_set_target_state(device, DASD_STATE_NEW);
2443         /* dasd_delete_device destroys the device reference. */
2444         block = device->block;
2445         device->block = NULL;
2446         dasd_delete_device(device);
2447         /*
2448          * life cycle of block is bound to device, so delete it after
2449          * device was safely removed
2450          */
2451         if (block)
2452                 dasd_free_block(block);
2453 }
2454
2455 /*
2456  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
2457  * the device is detected for the first time and is supposed to be used
2458  * or the user has started activation through sysfs.
2459  */
2460 int dasd_generic_set_online(struct ccw_device *cdev,
2461                             struct dasd_discipline *base_discipline)
2462 {
2463         struct dasd_discipline *discipline;
2464         struct dasd_device *device;
2465         int rc;
2466
2467         /* first online clears initial online feature flag */
2468         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
2469         device = dasd_create_device(cdev);
2470         if (IS_ERR(device))
2471                 return PTR_ERR(device);
2472
2473         discipline = base_discipline;
2474         if (device->features & DASD_FEATURE_USEDIAG) {
2475                 if (!dasd_diag_discipline_pointer) {
2476                         pr_warning("%s Setting the DASD online failed because "
2477                                    "of missing DIAG discipline\n",
2478                                    dev_name(&cdev->dev));
2479                         dasd_delete_device(device);
2480                         return -ENODEV;
2481                 }
2482                 discipline = dasd_diag_discipline_pointer;
2483         }
2484         if (!try_module_get(base_discipline->owner)) {
2485                 dasd_delete_device(device);
2486                 return -EINVAL;
2487         }
2488         if (!try_module_get(discipline->owner)) {
2489                 module_put(base_discipline->owner);
2490                 dasd_delete_device(device);
2491                 return -EINVAL;
2492         }
2493         device->base_discipline = base_discipline;
2494         device->discipline = discipline;
2495
2496         /* check_device will allocate block device if necessary */
2497         rc = discipline->check_device(device);
2498         if (rc) {
2499                 pr_warning("%s Setting the DASD online with discipline %s "
2500                            "failed with rc=%i\n",
2501                            dev_name(&cdev->dev), discipline->name, rc);
2502                 module_put(discipline->owner);
2503                 module_put(base_discipline->owner);
2504                 dasd_delete_device(device);
2505                 return rc;
2506         }
2507
2508         dasd_set_target_state(device, DASD_STATE_ONLINE);
2509         if (device->state <= DASD_STATE_KNOWN) {
2510                 pr_warning("%s Setting the DASD online failed because of a "
2511                            "missing discipline\n", dev_name(&cdev->dev));
2512                 rc = -ENODEV;
2513                 dasd_set_target_state(device, DASD_STATE_NEW);
2514                 if (device->block)
2515                         dasd_free_block(device->block);
2516                 dasd_delete_device(device);
2517         } else
2518                 pr_debug("dasd_generic device %s found\n",
2519                                 dev_name(&cdev->dev));
2520
2521         wait_event(dasd_init_waitq, _wait_for_device(device));
2522
2523         dasd_put_device(device);
2524         return rc;
2525 }
2526
2527 int dasd_generic_set_offline(struct ccw_device *cdev)
2528 {
2529         struct dasd_device *device;
2530         struct dasd_block *block;
2531         int max_count, open_count;
2532
2533         device = dasd_device_from_cdev(cdev);
2534         if (IS_ERR(device))
2535                 return PTR_ERR(device);
2536         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2537                 /* Already doing offline processing */
2538                 dasd_put_device(device);
2539                 return 0;
2540         }
2541         /*
2542          * We must make sure that this device is currently not in use.
2543          * The open_count is increased for every opener, that includes
2544          * the blkdev_get in dasd_scan_partitions. We are only interested
2545          * in the other openers.
2546          */
2547         if (device->block) {
2548                 max_count = device->block->bdev ? 0 : -1;
2549                 open_count = atomic_read(&device->block->open_count);
2550                 if (open_count > max_count) {
2551                         if (open_count > 0)
2552                                 pr_warning("%s: The DASD cannot be set offline "
2553                                            "with open count %i\n",
2554                                            dev_name(&cdev->dev), open_count);
2555                         else
2556                                 pr_warning("%s: The DASD cannot be set offline "
2557                                            "while it is in use\n",
2558                                            dev_name(&cdev->dev));
2559                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2560                         dasd_put_device(device);
2561                         return -EBUSY;
2562                 }
2563         }
2564         dasd_set_target_state(device, DASD_STATE_NEW);
2565         /* dasd_delete_device destroys the device reference. */
2566         block = device->block;
2567         device->block = NULL;
2568         dasd_delete_device(device);
2569         /*
2570          * life cycle of block is bound to device, so delete it after
2571          * device was safely removed
2572          */
2573         if (block)
2574                 dasd_free_block(block);
2575         return 0;
2576 }
2577
2578 int dasd_generic_notify(struct ccw_device *cdev, int event)
2579 {
2580         struct dasd_device *device;
2581         struct dasd_ccw_req *cqr;
2582         int ret;
2583
2584         device = dasd_device_from_cdev_locked(cdev);
2585         if (IS_ERR(device))
2586                 return 0;
2587         ret = 0;
2588         switch (event) {
2589         case CIO_GONE:
2590         case CIO_BOXED:
2591         case CIO_NO_PATH:
2592                 /* First of all call extended error reporting. */
2593                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2594
2595                 if (device->state < DASD_STATE_BASIC)
2596                         break;
2597                 /* Device is active. We want to keep it. */
2598                 list_for_each_entry(cqr, &device->ccw_queue, devlist)
2599                         if (cqr->status == DASD_CQR_IN_IO) {
2600                                 cqr->status = DASD_CQR_QUEUED;
2601                                 cqr->retries++;
2602                         }
2603                 dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
2604                 dasd_device_clear_timer(device);
2605                 dasd_schedule_device_bh(device);
2606                 ret = 1;
2607                 break;
2608         case CIO_OPER:
2609                 /* FIXME: add a sanity check. */
2610                 dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
2611                 if (device->stopped & DASD_UNRESUMED_PM) {
2612                         dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
2613                         dasd_restore_device(device);
2614                         ret = 1;
2615                         break;
2616                 }
2617                 dasd_schedule_device_bh(device);
2618                 if (device->block)
2619                         dasd_schedule_block_bh(device->block);
2620                 ret = 1;
2621                 break;
2622         }
2623         dasd_put_device(device);
2624         return ret;
2625 }
2626
2627 int dasd_generic_pm_freeze(struct ccw_device *cdev)
2628 {
2629         struct dasd_ccw_req *cqr, *n;
2630         int rc;
2631         struct list_head freeze_queue;
2632         struct dasd_device *device = dasd_device_from_cdev(cdev);
2633
2634         if (IS_ERR(device))
2635                 return PTR_ERR(device);
2636         /* disallow new I/O  */
2637         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
2638         /* clear active requests */
2639         INIT_LIST_HEAD(&freeze_queue);
2640         spin_lock_irq(get_ccwdev_lock(cdev));
2641         rc = 0;
2642         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2643                 /* Check status and move request to flush_queue */
2644                 if (cqr->status == DASD_CQR_IN_IO) {
2645                         rc = device->discipline->term_IO(cqr);
2646                         if (rc) {
2647                                 /* unable to terminate requeust */
2648                                 dev_err(&device->cdev->dev,
2649                                         "Unable to terminate request %p "
2650                                         "on suspend\n", cqr);
2651                                 spin_unlock_irq(get_ccwdev_lock(cdev));
2652                                 dasd_put_device(device);
2653                                 return rc;
2654                         }
2655                 }
2656                 list_move_tail(&cqr->devlist, &freeze_queue);
2657         }
2658
2659         spin_unlock_irq(get_ccwdev_lock(cdev));
2660
2661         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
2662                 wait_event(dasd_flush_wq,
2663                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2664                 if (cqr->status == DASD_CQR_CLEARED)
2665                         cqr->status = DASD_CQR_QUEUED;
2666         }
2667         /* move freeze_queue to start of the ccw_queue */
2668         spin_lock_irq(get_ccwdev_lock(cdev));
2669         list_splice_tail(&freeze_queue, &device->ccw_queue);
2670         spin_unlock_irq(get_ccwdev_lock(cdev));
2671
2672         if (device->discipline->freeze)
2673                 rc = device->discipline->freeze(device);
2674
2675         dasd_put_device(device);
2676         return rc;
2677 }
2678 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
2679
2680 int dasd_generic_restore_device(struct ccw_device *cdev)
2681 {
2682         struct dasd_device *device = dasd_device_from_cdev(cdev);
2683         int rc = 0;
2684
2685         if (IS_ERR(device))
2686                 return PTR_ERR(device);
2687
2688         /* allow new IO again */
2689         dasd_device_remove_stop_bits(device,
2690                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
2691
2692         dasd_schedule_device_bh(device);
2693
2694         /*
2695          * call discipline restore function
2696          * if device is stopped do nothing e.g. for disconnected devices
2697          */
2698         if (device->discipline->restore && !(device->stopped))
2699                 rc = device->discipline->restore(device);
2700         if (rc || device->stopped)
2701                 /*
2702                  * if the resume failed for the DASD we put it in
2703                  * an UNRESUMED stop state
2704                  */
2705                 device->stopped |= DASD_UNRESUMED_PM;
2706
2707         if (device->block)
2708                 dasd_schedule_block_bh(device->block);
2709
2710         dasd_put_device(device);
2711         return 0;
2712 }
2713 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
2714
2715 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
2716                                                    void *rdc_buffer,
2717                                                    int rdc_buffer_size,
2718                                                    int magic)
2719 {
2720         struct dasd_ccw_req *cqr;
2721         struct ccw1 *ccw;
2722         unsigned long *idaw;
2723
2724         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
2725
2726         if (IS_ERR(cqr)) {
2727                 /* internal error 13 - Allocating the RDC request failed*/
2728                 dev_err(&device->cdev->dev,
2729                          "An error occurred in the DASD device driver, "
2730                          "reason=%s\n", "13");
2731                 return cqr;
2732         }
2733
2734         ccw = cqr->cpaddr;
2735         ccw->cmd_code = CCW_CMD_RDC;
2736         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
2737                 idaw = (unsigned long *) (cqr->data);
2738                 ccw->cda = (__u32)(addr_t) idaw;
2739                 ccw->flags = CCW_FLAG_IDA;
2740                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
2741         } else {
2742                 ccw->cda = (__u32)(addr_t) rdc_buffer;
2743                 ccw->flags = 0;
2744         }
2745
2746         ccw->count = rdc_buffer_size;
2747         cqr->startdev = device;
2748         cqr->memdev = device;
2749         cqr->expires = 10*HZ;
2750         cqr->retries = 256;
2751         cqr->buildclk = get_clock();
2752         cqr->status = DASD_CQR_FILLED;
2753         return cqr;
2754 }
2755
2756
2757 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
2758                                 void *rdc_buffer, int rdc_buffer_size)
2759 {
2760         int ret;
2761         struct dasd_ccw_req *cqr;
2762
2763         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
2764                                      magic);
2765         if (IS_ERR(cqr))
2766                 return PTR_ERR(cqr);
2767
2768         ret = dasd_sleep_on(cqr);
2769         dasd_sfree_request(cqr, cqr->memdev);
2770         return ret;
2771 }
2772 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
2773
2774 /*
2775  *   In command mode and transport mode we need to look for sense
2776  *   data in different places. The sense data itself is allways
2777  *   an array of 32 bytes, so we can unify the sense data access
2778  *   for both modes.
2779  */
2780 char *dasd_get_sense(struct irb *irb)
2781 {
2782         struct tsb *tsb = NULL;
2783         char *sense = NULL;
2784
2785         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
2786                 if (irb->scsw.tm.tcw)
2787                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
2788                                           irb->scsw.tm.tcw);
2789                 if (tsb && tsb->length == 64 && tsb->flags)
2790                         switch (tsb->flags & 0x07) {
2791                         case 1: /* tsa_iostat */
2792                                 sense = tsb->tsa.iostat.sense;
2793                                 break;
2794                         case 2: /* tsa_ddpc */
2795                                 sense = tsb->tsa.ddpc.sense;
2796                                 break;
2797                         default:
2798                                 /* currently we don't use interrogate data */
2799                                 break;
2800                         }
2801         } else if (irb->esw.esw0.erw.cons) {
2802                 sense = irb->ecw;
2803         }
2804         return sense;
2805 }
2806 EXPORT_SYMBOL_GPL(dasd_get_sense);
2807
2808 static int __init dasd_init(void)
2809 {
2810         int rc;
2811
2812         init_waitqueue_head(&dasd_init_waitq);
2813         init_waitqueue_head(&dasd_flush_wq);
2814         init_waitqueue_head(&generic_waitq);
2815
2816         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2817         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
2818         if (dasd_debug_area == NULL) {
2819                 rc = -ENOMEM;
2820                 goto failed;
2821         }
2822         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2823         debug_set_level(dasd_debug_area, DBF_WARNING);
2824
2825         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2826
2827         dasd_diag_discipline_pointer = NULL;
2828
2829         rc = dasd_devmap_init();
2830         if (rc)
2831                 goto failed;
2832         rc = dasd_gendisk_init();
2833         if (rc)
2834                 goto failed;
2835         rc = dasd_parse();
2836         if (rc)
2837                 goto failed;
2838         rc = dasd_eer_init();
2839         if (rc)
2840                 goto failed;
2841 #ifdef CONFIG_PROC_FS
2842         rc = dasd_proc_init();
2843         if (rc)
2844                 goto failed;
2845 #endif
2846
2847         return 0;
2848 failed:
2849         pr_info("The DASD device driver could not be initialized\n");
2850         dasd_exit();
2851         return rc;
2852 }
2853
2854 module_init(dasd_init);
2855 module_exit(dasd_exit);
2856
2857 EXPORT_SYMBOL(dasd_debug_area);
2858 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2859
2860 EXPORT_SYMBOL(dasd_add_request_head);
2861 EXPORT_SYMBOL(dasd_add_request_tail);
2862 EXPORT_SYMBOL(dasd_cancel_req);
2863 EXPORT_SYMBOL(dasd_device_clear_timer);
2864 EXPORT_SYMBOL(dasd_block_clear_timer);
2865 EXPORT_SYMBOL(dasd_enable_device);
2866 EXPORT_SYMBOL(dasd_int_handler);
2867 EXPORT_SYMBOL(dasd_kfree_request);
2868 EXPORT_SYMBOL(dasd_kick_device);
2869 EXPORT_SYMBOL(dasd_kmalloc_request);
2870 EXPORT_SYMBOL(dasd_schedule_device_bh);
2871 EXPORT_SYMBOL(dasd_schedule_block_bh);
2872 EXPORT_SYMBOL(dasd_set_target_state);
2873 EXPORT_SYMBOL(dasd_device_set_timer);
2874 EXPORT_SYMBOL(dasd_block_set_timer);
2875 EXPORT_SYMBOL(dasd_sfree_request);
2876 EXPORT_SYMBOL(dasd_sleep_on);
2877 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2878 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2879 EXPORT_SYMBOL(dasd_smalloc_request);
2880 EXPORT_SYMBOL(dasd_start_IO);
2881 EXPORT_SYMBOL(dasd_term_IO);
2882
2883 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2884 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2885 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2886 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2887 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2888 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
2889 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2890 EXPORT_SYMBOL_GPL(dasd_alloc_block);
2891 EXPORT_SYMBOL_GPL(dasd_free_block);