drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 /*
  42  * SECTION: exported variables of dasd.c
  43  */
  44 debug_info_t *dasd_debug_area;
  45 EXPORT_SYMBOL(dasd_debug_area);
  46 static struct dentry *dasd_debugfs_root_entry;
  47 struct dasd_discipline *dasd_diag_discipline_pointer;
  48 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  49 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  50
  51 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  52 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  53                    " Copyright IBM Corp. 2000");
  54 MODULE_SUPPORTED_DEVICE("dasd");
  55 MODULE_LICENSE("GPL");
  56
  57 /*
  58  * SECTION: prototypes for static functions of dasd.c
  59  */
  60 static int  dasd_alloc_queue(struct dasd_block *);
  61 static void dasd_setup_queue(struct dasd_block *);
  62 static void dasd_free_queue(struct dasd_block *);
  63 static void dasd_flush_request_queue(struct dasd_block *);
  64 static int dasd_flush_block_queue(struct dasd_block *);
  65 static void dasd_device_tasklet(struct dasd_device *);
  66 static void dasd_block_tasklet(struct dasd_block *);
  67 static void do_kick_device(struct work_struct *);
  68 static void do_restore_device(struct work_struct *);
  69 static void do_reload_device(struct work_struct *);
  70 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  71 static void dasd_device_timeout(unsigned long);
  72 static void dasd_block_timeout(unsigned long);
  73 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  74 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  75 static void dasd_profile_exit(struct dasd_profile *);
  76
  77 /*
  78  * SECTION: Operations on the device structure.
  79  */
  80 static wait_queue_head_t dasd_init_waitq;
  81 static wait_queue_head_t dasd_flush_wq;
  82 static wait_queue_head_t generic_waitq;
  83 static wait_queue_head_t shutdown_waitq;
  84
  85 /*
  86  * Allocate memory for a new device structure.
  87  */
  88 struct dasd_device *dasd_alloc_device(void)
  89 {
  90         struct dasd_device *device;
  91
  92         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  93         if (!device)
  94                 return ERR_PTR(-ENOMEM);
  95
  96         /* Get two pages for normal block device operations. */
  97         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  98         if (!device->ccw_mem) {
  99                 kfree(device);
 100                 return ERR_PTR(-ENOMEM);
 101         }
 102         /* Get one page for error recovery. */
 103         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 104         if (!device->erp_mem) {
 105                 free_pages((unsigned long) device->ccw_mem, 1);
 106                 kfree(device);
 107                 return ERR_PTR(-ENOMEM);
 108         }
 109
 110         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 111         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 112         spin_lock_init(&device->mem_lock);
 113         atomic_set(&device->tasklet_scheduled, 0);
 114         tasklet_init(&device->tasklet,
 115                      (void (*)(unsigned long)) dasd_device_tasklet,
 116                      (unsigned long) device);
 117         INIT_LIST_HEAD(&device->ccw_queue);
 118         init_timer(&device->timer);
 119         device->timer.function = dasd_device_timeout;
 120         device->timer.data = (unsigned long) device;
 121         INIT_WORK(&device->kick_work, do_kick_device);
 122         INIT_WORK(&device->restore_device, do_restore_device);
 123         INIT_WORK(&device->reload_device, do_reload_device);
 124         device->state = DASD_STATE_NEW;
 125         device->target = DASD_STATE_NEW;
 126         mutex_init(&device->state_mutex);
 127         spin_lock_init(&device->profile.lock);
 128         return device;
 129 }
 130
 131 /*
 132  * Free memory of a device structure.
 133  */
 134 void dasd_free_device(struct dasd_device *device)
 135 {
 136         kfree(device->private);
 137         free_page((unsigned long) device->erp_mem);
 138         free_pages((unsigned long) device->ccw_mem, 1);
 139         kfree(device);
 140 }
 141
 142 /*
 143  * Allocate memory for a new device structure.
 144  */
 145 struct dasd_block *dasd_alloc_block(void)
 146 {
 147         struct dasd_block *block;
 148
 149         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 150         if (!block)
 151                 return ERR_PTR(-ENOMEM);
 152         /* open_count = 0 means device online but not in use */
 153         atomic_set(&block->open_count, -1);
 154
 155         spin_lock_init(&block->request_queue_lock);
 156         atomic_set(&block->tasklet_scheduled, 0);
 157         tasklet_init(&block->tasklet,
 158                      (void (*)(unsigned long)) dasd_block_tasklet,
 159                      (unsigned long) block);
 160         INIT_LIST_HEAD(&block->ccw_queue);
 161         spin_lock_init(&block->queue_lock);
 162         init_timer(&block->timer);
 163         block->timer.function = dasd_block_timeout;
 164         block->timer.data = (unsigned long) block;
 165         spin_lock_init(&block->profile.lock);
 166
 167         return block;
 168 }
 169 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 170
 171 /*
 172  * Free memory of a device structure.
 173  */
 174 void dasd_free_block(struct dasd_block *block)
 175 {
 176         kfree(block);
 177 }
 178 EXPORT_SYMBOL_GPL(dasd_free_block);
 179
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         int rc;
 186
 187         /*
 188          * As long as the device is not in state DASD_STATE_NEW we want to
 189          * keep the reference count > 0.
 190          */
 191         dasd_get_device(device);
 192
 193         if (device->block) {
 194                 rc = dasd_alloc_queue(device->block);
 195                 if (rc) {
 196                         dasd_put_device(device);
 197                         return rc;
 198                 }
 199         }
 200         device->state = DASD_STATE_KNOWN;
 201         return 0;
 202 }
 203
 204 /*
 205  * Let the system forget about a device.
 206  */
 207 static int dasd_state_known_to_new(struct dasd_device *device)
 208 {
 209         /* Disable extended error reporting for this device. */
 210         dasd_eer_disable(device);
 211         /* Forget the discipline information. */
 212         if (device->discipline) {
 213                 if (device->discipline->uncheck_device)
 214                         device->discipline->uncheck_device(device);
 215                 module_put(device->discipline->owner);
 216         }
 217         device->discipline = NULL;
 218         if (device->base_discipline)
 219                 module_put(device->base_discipline->owner);
 220         device->base_discipline = NULL;
 221         device->state = DASD_STATE_NEW;
 222
 223         if (device->block)
 224                 dasd_free_queue(device->block);
 225
 226         /* Give up reference we took in dasd_state_new_to_known. */
 227         dasd_put_device(device);
 228         return 0;
 229 }
 230
 231 static struct dentry *dasd_debugfs_setup(const char *name,
 232                                          struct dentry *base_dentry)
 233 {
 234         struct dentry *pde;
 235
 236         if (!base_dentry)
 237                 return NULL;
 238         pde = debugfs_create_dir(name, base_dentry);
 239         if (!pde || IS_ERR(pde))
 240                 return NULL;
 241         return pde;
 242 }
 243
 244 /*
 245  * Request the irq line for the device.
 246  */
 247 static int dasd_state_known_to_basic(struct dasd_device *device)
 248 {
 249         struct dasd_block *block = device->block;
 250         int rc = 0;
 251
 252         /* Allocate and register gendisk structure. */
 253         if (block) {
 254                 rc = dasd_gendisk_alloc(block);
 255                 if (rc)
 256                         return rc;
 257                 block->debugfs_dentry =
 258                         dasd_debugfs_setup(block->gdp->disk_name,
 259                                            dasd_debugfs_root_entry);
 260                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 261                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 262                         dasd_profile_on(&device->block->profile);
 263         }
 264         device->debugfs_dentry =
 265                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 266                                    dasd_debugfs_root_entry);
 267         dasd_profile_init(&device->profile, device->debugfs_dentry);
 268
 269         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 270         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 271                                             8 * sizeof(long));
 272         debug_register_view(device->debug_area, &debug_sprintf_view);
 273         debug_set_level(device->debug_area, DBF_WARNING);
 274         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 275
 276         device->state = DASD_STATE_BASIC;
 277
 278         return rc;
 279 }
 280
 281 /*
 282  * Release the irq line for the device. Terminate any running i/o.
 283  */
 284 static int dasd_state_basic_to_known(struct dasd_device *device)
 285 {
 286         int rc;
 287
 288         if (device->discipline->basic_to_known) {
 289                 rc = device->discipline->basic_to_known(device);
 290                 if (rc)
 291                         return rc;
 292         }
 293
 294         if (device->block) {
 295                 dasd_profile_exit(&device->block->profile);
 296                 debugfs_remove(device->block->debugfs_dentry);
 297                 dasd_gendisk_free(device->block);
 298                 dasd_block_clear_timer(device->block);
 299         }
 300         rc = dasd_flush_device_queue(device);
 301         if (rc)
 302                 return rc;
 303         dasd_device_clear_timer(device);
 304         dasd_profile_exit(&device->profile);
 305         debugfs_remove(device->debugfs_dentry);
 306         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 307         if (device->debug_area != NULL) {
 308                 debug_unregister(device->debug_area);
 309                 device->debug_area = NULL;
 310         }
 311         device->state = DASD_STATE_KNOWN;
 312         return 0;
 313 }
 314
 315 /*
 316  * Do the initial analysis. The do_analysis function may return
 317  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 318  * until the discipline decides to continue the startup sequence
 319  * by calling the function dasd_change_state. The eckd disciplines
 320  * uses this to start a ccw that detects the format. The completion
 321  * interrupt for this detection ccw uses the kernel event daemon to
 322  * trigger the call to dasd_change_state. All this is done in the
 323  * discipline code, see dasd_eckd.c.
 324  * After the analysis ccw is done (do_analysis returned 0) the block
 325  * device is setup.
 326  * In case the analysis returns an error, the device setup is stopped
 327  * (a fake disk was already added to allow formatting).
 328  */
 329 static int dasd_state_basic_to_ready(struct dasd_device *device)
 330 {
 331         int rc;
 332         struct dasd_block *block;
 333
 334         rc = 0;
 335         block = device->block;
 336         /* make disk known with correct capacity */
 337         if (block) {
 338                 if (block->base->discipline->do_analysis != NULL)
 339                         rc = block->base->discipline->do_analysis(block);
 340                 if (rc) {
 341                         if (rc != -EAGAIN) {
 342                                 device->state = DASD_STATE_UNFMT;
 343                                 goto out;
 344                         }
 345                         return rc;
 346                 }
 347                 dasd_setup_queue(block);
 348                 set_capacity(block->gdp,
 349                              block->blocks << block->s2b_shift);
 350                 device->state = DASD_STATE_READY;
 351                 rc = dasd_scan_partitions(block);
 352                 if (rc) {
 353                         device->state = DASD_STATE_BASIC;
 354                         return rc;
 355                 }
 356         } else {
 357                 device->state = DASD_STATE_READY;
 358         }
 359 out:
 360         if (device->discipline->basic_to_ready)
 361                 rc = device->discipline->basic_to_ready(device);
 362         return rc;
 363 }
 364
 365 static inline
 366 int _wait_for_empty_queues(struct dasd_device *device)
 367 {
 368         if (device->block)
 369                 return list_empty(&device->ccw_queue) &&
 370                         list_empty(&device->block->ccw_queue);
 371         else
 372                 return list_empty(&device->ccw_queue);
 373 }
 374
 375 /*
 376  * Remove device from block device layer. Destroy dirty buffers.
 377  * Forget format information. Check if the target level is basic
 378  * and if it is create fake disk for formatting.
 379  */
 380 static int dasd_state_ready_to_basic(struct dasd_device *device)
 381 {
 382         int rc;
 383
 384         device->state = DASD_STATE_BASIC;
 385         if (device->block) {
 386                 struct dasd_block *block = device->block;
 387                 rc = dasd_flush_block_queue(block);
 388                 if (rc) {
 389                         device->state = DASD_STATE_READY;
 390                         return rc;
 391                 }
 392                 dasd_flush_request_queue(block);
 393                 dasd_destroy_partitions(block);
 394                 block->blocks = 0;
 395                 block->bp_block = 0;
 396                 block->s2b_shift = 0;
 397         }
 398         return 0;
 399 }
 400
 401 /*
 402  * Back to basic.
 403  */
 404 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 405 {
 406         device->state = DASD_STATE_BASIC;
 407         return 0;
 408 }
 409
 410 /*
 411  * Make the device online and schedule the bottom half to start
 412  * the requeueing of requests from the linux request queue to the
 413  * ccw queue.
 414  */
 415 static int
 416 dasd_state_ready_to_online(struct dasd_device * device)
 417 {
 418         struct gendisk *disk;
 419         struct disk_part_iter piter;
 420         struct hd_struct *part;
 421
 422         device->state = DASD_STATE_ONLINE;
 423         if (device->block) {
 424                 dasd_schedule_block_bh(device->block);
 425                 if ((device->features & DASD_FEATURE_USERAW)) {
 426                         disk = device->block->gdp;
 427                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 428                         return 0;
 429                 }
 430                 disk = device->block->bdev->bd_disk;
 431                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 432                 while ((part = disk_part_iter_next(&piter)))
 433                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 434                 disk_part_iter_exit(&piter);
 435         }
 436         return 0;
 437 }
 438
 439 /*
 440  * Stop the requeueing of requests again.
 441  */
 442 static int dasd_state_online_to_ready(struct dasd_device *device)
 443 {
 444         int rc;
 445         struct gendisk *disk;
 446         struct disk_part_iter piter;
 447         struct hd_struct *part;
 448
 449         if (device->discipline->online_to_ready) {
 450                 rc = device->discipline->online_to_ready(device);
 451                 if (rc)
 452                         return rc;
 453         }
 454
 455         device->state = DASD_STATE_READY;
 456         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 457                 disk = device->block->bdev->bd_disk;
 458                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 459                 while ((part = disk_part_iter_next(&piter)))
 460                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 461                 disk_part_iter_exit(&piter);
 462         }
 463         return 0;
 464 }
 465
 466 /*
 467  * Device startup state changes.
 468  */
 469 static int dasd_increase_state(struct dasd_device *device)
 470 {
 471         int rc;
 472
 473         rc = 0;
 474         if (device->state == DASD_STATE_NEW &&
 475             device->target >= DASD_STATE_KNOWN)
 476                 rc = dasd_state_new_to_known(device);
 477
 478         if (!rc &&
 479             device->state == DASD_STATE_KNOWN &&
 480             device->target >= DASD_STATE_BASIC)
 481                 rc = dasd_state_known_to_basic(device);
 482
 483         if (!rc &&
 484             device->state == DASD_STATE_BASIC &&
 485             device->target >= DASD_STATE_READY)
 486                 rc = dasd_state_basic_to_ready(device);
 487
 488         if (!rc &&
 489             device->state == DASD_STATE_UNFMT &&
 490             device->target > DASD_STATE_UNFMT)
 491                 rc = -EPERM;
 492
 493         if (!rc &&
 494             device->state == DASD_STATE_READY &&
 495             device->target >= DASD_STATE_ONLINE)
 496                 rc = dasd_state_ready_to_online(device);
 497
 498         return rc;
 499 }
 500
 501 /*
 502  * Device shutdown state changes.
 503  */
 504 static int dasd_decrease_state(struct dasd_device *device)
 505 {
 506         int rc;
 507
 508         rc = 0;
 509         if (device->state == DASD_STATE_ONLINE &&
 510             device->target <= DASD_STATE_READY)
 511                 rc = dasd_state_online_to_ready(device);
 512
 513         if (!rc &&
 514             device->state == DASD_STATE_READY &&
 515             device->target <= DASD_STATE_BASIC)
 516                 rc = dasd_state_ready_to_basic(device);
 517
 518         if (!rc &&
 519             device->state == DASD_STATE_UNFMT &&
 520             device->target <= DASD_STATE_BASIC)
 521                 rc = dasd_state_unfmt_to_basic(device);
 522
 523         if (!rc &&
 524             device->state == DASD_STATE_BASIC &&
 525             device->target <= DASD_STATE_KNOWN)
 526                 rc = dasd_state_basic_to_known(device);
 527
 528         if (!rc &&
 529             device->state == DASD_STATE_KNOWN &&
 530             device->target <= DASD_STATE_NEW)
 531                 rc = dasd_state_known_to_new(device);
 532
 533         return rc;
 534 }
 535
 536 /*
 537  * This is the main startup/shutdown routine.
 538  */
 539 static void dasd_change_state(struct dasd_device *device)
 540 {
 541         int rc;
 542
 543         if (device->state == device->target)
 544                 /* Already where we want to go today... */
 545                 return;
 546         if (device->state < device->target)
 547                 rc = dasd_increase_state(device);
 548         else
 549                 rc = dasd_decrease_state(device);
 550         if (rc == -EAGAIN)
 551                 return;
 552         if (rc)
 553                 device->target = device->state;
 554
 555         /* let user-space know that the device status changed */
 556         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 557
 558         if (device->state == device->target)
 559                 wake_up(&dasd_init_waitq);
 560 }
 561
 562 /*
 563  * Kick starter for devices that did not complete the startup/shutdown
 564  * procedure or were sleeping because of a pending state.
 565  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 566  * event daemon.
 567  */
 568 static void do_kick_device(struct work_struct *work)
 569 {
 570         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 571         mutex_lock(&device->state_mutex);
 572         dasd_change_state(device);
 573         mutex_unlock(&device->state_mutex);
 574         dasd_schedule_device_bh(device);
 575         dasd_put_device(device);
 576 }
 577
 578 void dasd_kick_device(struct dasd_device *device)
 579 {
 580         dasd_get_device(device);
 581         /* queue call to dasd_kick_device to the kernel event daemon. */
 582         schedule_work(&device->kick_work);
 583 }
 584 EXPORT_SYMBOL(dasd_kick_device);
 585
 586 /*
 587  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 588  * event daemon.
 589  */
 590 static void do_reload_device(struct work_struct *work)
 591 {
 592         struct dasd_device *device = container_of(work, struct dasd_device,
 593                                                   reload_device);
 594         device->discipline->reload(device);
 595         dasd_put_device(device);
 596 }
 597
 598 void dasd_reload_device(struct dasd_device *device)
 599 {
 600         dasd_get_device(device);
 601         /* queue call to dasd_reload_device to the kernel event daemon. */
 602         schedule_work(&device->reload_device);
 603 }
 604 EXPORT_SYMBOL(dasd_reload_device);
 605
 606 /*
 607  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 608  * event daemon.
 609  */
 610 static void do_restore_device(struct work_struct *work)
 611 {
 612         struct dasd_device *device = container_of(work, struct dasd_device,
 613                                                   restore_device);
 614         device->cdev->drv->restore(device->cdev);
 615         dasd_put_device(device);
 616 }
 617
 618 void dasd_restore_device(struct dasd_device *device)
 619 {
 620         dasd_get_device(device);
 621         /* queue call to dasd_restore_device to the kernel event daemon. */
 622         schedule_work(&device->restore_device);
 623 }
 624
 625 /*
 626  * Set the target state for a device and starts the state change.
 627  */
 628 void dasd_set_target_state(struct dasd_device *device, int target)
 629 {
 630         dasd_get_device(device);
 631         mutex_lock(&device->state_mutex);
 632         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 633         if (dasd_probeonly && target > DASD_STATE_READY)
 634                 target = DASD_STATE_READY;
 635         if (device->target != target) {
 636                 if (device->state == target)
 637                         wake_up(&dasd_init_waitq);
 638                 device->target = target;
 639         }
 640         if (device->state != device->target)
 641                 dasd_change_state(device);
 642         mutex_unlock(&device->state_mutex);
 643         dasd_put_device(device);
 644 }
 645 EXPORT_SYMBOL(dasd_set_target_state);
 646
 647 /*
 648  * Enable devices with device numbers in [from..to].
 649  */
 650 static inline int _wait_for_device(struct dasd_device *device)
 651 {
 652         return (device->state == device->target);
 653 }
 654
 655 void dasd_enable_device(struct dasd_device *device)
 656 {
 657         dasd_set_target_state(device, DASD_STATE_ONLINE);
 658         if (device->state <= DASD_STATE_KNOWN)
 659                 /* No discipline for device found. */
 660                 dasd_set_target_state(device, DASD_STATE_NEW);
 661         /* Now wait for the devices to come up. */
 662         wait_event(dasd_init_waitq, _wait_for_device(device));
 663
 664         dasd_reload_device(device);
 665         if (device->discipline->kick_validate)
 666                 device->discipline->kick_validate(device);
 667 }
 668 EXPORT_SYMBOL(dasd_enable_device);
 669
 670 /*
 671  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 672  */
 673
 674 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 675
 676 #ifdef CONFIG_DASD_PROFILE
 677 struct dasd_profile_info dasd_global_profile_data;
 678 static struct dentry *dasd_global_profile_dentry;
 679 static struct dentry *dasd_debugfs_global_entry;
 680
 681 /*
 682  * Add profiling information for cqr before execution.
 683  */
 684 static void dasd_profile_start(struct dasd_block *block,
 685                                struct dasd_ccw_req *cqr,
 686                                struct request *req)
 687 {
 688         struct list_head *l;
 689         unsigned int counter;
 690         struct dasd_device *device;
 691
 692         /* count the length of the chanq for statistics */
 693         counter = 0;
 694         if (dasd_global_profile_level || block->profile.data)
 695                 list_for_each(l, &block->ccw_queue)
 696                         if (++counter >= 31)
 697                                 break;
 698
 699         if (dasd_global_profile_level) {
 700                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 701                 if (rq_data_dir(req) == READ)
 702                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 703         }
 704
 705         spin_lock(&block->profile.lock);
 706         if (block->profile.data) {
 707                 block->profile.data->dasd_io_nr_req[counter]++;
 708                 if (rq_data_dir(req) == READ)
 709                         block->profile.data->dasd_read_nr_req[counter]++;
 710         }
 711         spin_unlock(&block->profile.lock);
 712
 713         /*
 714          * We count the request for the start device, even though it may run on
 715          * some other device due to error recovery. This way we make sure that
 716          * we count each request only once.
 717          */
 718         device = cqr->startdev;
 719         if (device->profile.data) {
 720                 counter = 1; /* request is not yet queued on the start device */
 721                 list_for_each(l, &device->ccw_queue)
 722                         if (++counter >= 31)
 723                                 break;
 724         }
 725         spin_lock(&device->profile.lock);
 726         if (device->profile.data) {
 727                 device->profile.data->dasd_io_nr_req[counter]++;
 728                 if (rq_data_dir(req) == READ)
 729                         device->profile.data->dasd_read_nr_req[counter]++;
 730         }
 731         spin_unlock(&device->profile.lock);
 732 }
 733
 734 /*
 735  * Add profiling information for cqr after execution.
 736  */
 737
 738 #define dasd_profile_counter(value, index)                         \
 739 {                                                                  \
 740         for (index = 0; index < 31 && value >> (2+index); index++) \
 741                 ;                                                  \
 742 }
 743
 744 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 745                                       int is_alias,
 746                                       int is_tpm,
 747                                       int is_read,
 748                                       long sectors,
 749                                       int sectors_ind,
 750                                       int tottime_ind,
 751                                       int tottimeps_ind,
 752                                       int strtime_ind,
 753                                       int irqtime_ind,
 754                                       int irqtimeps_ind,
 755                                       int endtime_ind)
 756 {
 757         /* in case of an overflow, reset the whole profile */
 758         if (data->dasd_io_reqs == UINT_MAX) {
 759                         memset(data, 0, sizeof(*data));
 760                         getnstimeofday(&data->starttod);
 761         }
 762         data->dasd_io_reqs++;
 763         data->dasd_io_sects += sectors;
 764         if (is_alias)
 765                 data->dasd_io_alias++;
 766         if (is_tpm)
 767                 data->dasd_io_tpm++;
 768
 769         data->dasd_io_secs[sectors_ind]++;
 770         data->dasd_io_times[tottime_ind]++;
 771         data->dasd_io_timps[tottimeps_ind]++;
 772         data->dasd_io_time1[strtime_ind]++;
 773         data->dasd_io_time2[irqtime_ind]++;
 774         data->dasd_io_time2ps[irqtimeps_ind]++;
 775         data->dasd_io_time3[endtime_ind]++;
 776
 777         if (is_read) {
 778                 data->dasd_read_reqs++;
 779                 data->dasd_read_sects += sectors;
 780                 if (is_alias)
 781                         data->dasd_read_alias++;
 782                 if (is_tpm)
 783                         data->dasd_read_tpm++;
 784                 data->dasd_read_secs[sectors_ind]++;
 785                 data->dasd_read_times[tottime_ind]++;
 786                 data->dasd_read_time1[strtime_ind]++;
 787                 data->dasd_read_time2[irqtime_ind]++;
 788                 data->dasd_read_time3[endtime_ind]++;
 789         }
 790 }
 791
 792 static void dasd_profile_end(struct dasd_block *block,
 793                              struct dasd_ccw_req *cqr,
 794                              struct request *req)
 795 {
 796         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 797         long tottimeps, sectors;
 798         struct dasd_device *device;
 799         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 800         int irqtime_ind, irqtimeps_ind, endtime_ind;
 801
 802         device = cqr->startdev;
 803         if (!(dasd_global_profile_level ||
 804               block->profile.data ||
 805               device->profile.data))
 806                 return;
 807
 808         sectors = blk_rq_sectors(req);
 809         if (!cqr->buildclk || !cqr->startclk ||
 810             !cqr->stopclk || !cqr->endclk ||
 811             !sectors)
 812                 return;
 813
 814         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 815         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 816         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 817         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 818         tottimeps = tottime / sectors;
 819
 820         dasd_profile_counter(sectors, sectors_ind);
 821         dasd_profile_counter(tottime, tottime_ind);
 822         dasd_profile_counter(tottimeps, tottimeps_ind);
 823         dasd_profile_counter(strtime, strtime_ind);
 824         dasd_profile_counter(irqtime, irqtime_ind);
 825         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 826         dasd_profile_counter(endtime, endtime_ind);
 827
 828         if (dasd_global_profile_level) {
 829                 dasd_profile_end_add_data(&dasd_global_profile_data,
 830                                           cqr->startdev != block->base,
 831                                           cqr->cpmode == 1,
 832                                           rq_data_dir(req) == READ,
 833                                           sectors, sectors_ind, tottime_ind,
 834                                           tottimeps_ind, strtime_ind,
 835                                           irqtime_ind, irqtimeps_ind,
 836                                           endtime_ind);
 837         }
 838
 839         spin_lock(&block->profile.lock);
 840         if (block->profile.data)
 841                 dasd_profile_end_add_data(block->profile.data,
 842                                           cqr->startdev != block->base,
 843                                           cqr->cpmode == 1,
 844                                           rq_data_dir(req) == READ,
 845                                           sectors, sectors_ind, tottime_ind,
 846                                           tottimeps_ind, strtime_ind,
 847                                           irqtime_ind, irqtimeps_ind,
 848                                           endtime_ind);
 849         spin_unlock(&block->profile.lock);
 850
 851         spin_lock(&device->profile.lock);
 852         if (device->profile.data)
 853                 dasd_profile_end_add_data(device->profile.data,
 854                                           cqr->startdev != block->base,
 855                                           cqr->cpmode == 1,
 856                                           rq_data_dir(req) == READ,
 857                                           sectors, sectors_ind, tottime_ind,
 858                                           tottimeps_ind, strtime_ind,
 859                                           irqtime_ind, irqtimeps_ind,
 860                                           endtime_ind);
 861         spin_unlock(&device->profile.lock);
 862 }
 863
 864 void dasd_profile_reset(struct dasd_profile *profile)
 865 {
 866         struct dasd_profile_info *data;
 867
 868         spin_lock_bh(&profile->lock);
 869         data = profile->data;
 870         if (!data) {
 871                 spin_unlock_bh(&profile->lock);
 872                 return;
 873         }
 874         memset(data, 0, sizeof(*data));
 875         getnstimeofday(&data->starttod);
 876         spin_unlock_bh(&profile->lock);
 877 }
 878
 879 void dasd_global_profile_reset(void)
 880 {
 881         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 882         getnstimeofday(&dasd_global_profile_data.starttod);
 883 }
 884
 885 int dasd_profile_on(struct dasd_profile *profile)
 886 {
 887         struct dasd_profile_info *data;
 888
 889         data = kzalloc(sizeof(*data), GFP_KERNEL);
 890         if (!data)
 891                 return -ENOMEM;
 892         spin_lock_bh(&profile->lock);
 893         if (profile->data) {
 894                 spin_unlock_bh(&profile->lock);
 895                 kfree(data);
 896                 return 0;
 897         }
 898         getnstimeofday(&data->starttod);
 899         profile->data = data;
 900         spin_unlock_bh(&profile->lock);
 901         return 0;
 902 }
 903
 904 void dasd_profile_off(struct dasd_profile *profile)
 905 {
 906         spin_lock_bh(&profile->lock);
 907         kfree(profile->data);
 908         profile->data = NULL;
 909         spin_unlock_bh(&profile->lock);
 910 }
 911
 912 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 913 {
 914         char *buffer;
 915
 916         buffer = vmalloc(user_len + 1);
 917         if (buffer == NULL)
 918                 return ERR_PTR(-ENOMEM);
 919         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 920                 vfree(buffer);
 921                 return ERR_PTR(-EFAULT);
 922         }
 923         /* got the string, now strip linefeed. */
 924         if (buffer[user_len - 1] == '\n')
 925                 buffer[user_len - 1] = 0;
 926         else
 927                 buffer[user_len] = 0;
 928         return buffer;
 929 }
 930
 931 static ssize_t dasd_stats_write(struct file *file,
 932                                 const char __user *user_buf,
 933                                 size_t user_len, loff_t *pos)
 934 {
 935         char *buffer, *str;
 936         int rc;
 937         struct seq_file *m = (struct seq_file *)file->private_data;
 938         struct dasd_profile *prof = m->private;
 939
 940         if (user_len > 65536)
 941                 user_len = 65536;
 942         buffer = dasd_get_user_string(user_buf, user_len);
 943         if (IS_ERR(buffer))
 944                 return PTR_ERR(buffer);
 945
 946         str = skip_spaces(buffer);
 947         rc = user_len;
 948         if (strncmp(str, "reset", 5) == 0) {
 949                 dasd_profile_reset(prof);
 950         } else if (strncmp(str, "on", 2) == 0) {
 951                 rc = dasd_profile_on(prof);
 952                 if (!rc)
 953                         rc = user_len;
 954         } else if (strncmp(str, "off", 3) == 0) {
 955                 dasd_profile_off(prof);
 956         } else
 957                 rc = -EINVAL;
 958         vfree(buffer);
 959         return rc;
 960 }
 961
 962 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 963 {
 964         int i;
 965
 966         for (i = 0; i < 32; i++)
 967                 seq_printf(m, "%u ", array[i]);
 968         seq_putc(m, '\n');
 969 }
 970
 971 static void dasd_stats_seq_print(struct seq_file *m,
 972                                  struct dasd_profile_info *data)
 973 {
 974         seq_printf(m, "start_time %ld.%09ld\n",
 975                    data->starttod.tv_sec, data->starttod.tv_nsec);
 976         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 977         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 978         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 979         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 980         seq_puts(m, "histogram_sectors ");
 981         dasd_stats_array(m, data->dasd_io_secs);
 982         seq_puts(m, "histogram_io_times ");
 983         dasd_stats_array(m, data->dasd_io_times);
 984         seq_puts(m, "histogram_io_times_weighted ");
 985         dasd_stats_array(m, data->dasd_io_timps);
 986         seq_puts(m, "histogram_time_build_to_ssch ");
 987         dasd_stats_array(m, data->dasd_io_time1);
 988         seq_puts(m, "histogram_time_ssch_to_irq ");
 989         dasd_stats_array(m, data->dasd_io_time2);
 990         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
 991         dasd_stats_array(m, data->dasd_io_time2ps);
 992         seq_puts(m, "histogram_time_irq_to_end ");
 993         dasd_stats_array(m, data->dasd_io_time3);
 994         seq_puts(m, "histogram_ccw_queue_length ");
 995         dasd_stats_array(m, data->dasd_io_nr_req);
 996         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 997         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 998         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 999         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1000         seq_puts(m, "histogram_read_sectors ");
1001         dasd_stats_array(m, data->dasd_read_secs);
1002         seq_puts(m, "histogram_read_times ");
1003         dasd_stats_array(m, data->dasd_read_times);
1004         seq_puts(m, "histogram_read_time_build_to_ssch ");
1005         dasd_stats_array(m, data->dasd_read_time1);
1006         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1007         dasd_stats_array(m, data->dasd_read_time2);
1008         seq_puts(m, "histogram_read_time_irq_to_end ");
1009         dasd_stats_array(m, data->dasd_read_time3);
1010         seq_puts(m, "histogram_read_ccw_queue_length ");
1011         dasd_stats_array(m, data->dasd_read_nr_req);
1012 }
1013
1014 static int dasd_stats_show(struct seq_file *m, void *v)
1015 {
1016         struct dasd_profile *profile;
1017         struct dasd_profile_info *data;
1018
1019         profile = m->private;
1020         spin_lock_bh(&profile->lock);
1021         data = profile->data;
1022         if (!data) {
1023                 spin_unlock_bh(&profile->lock);
1024                 seq_puts(m, "disabled\n");
1025                 return 0;
1026         }
1027         dasd_stats_seq_print(m, data);
1028         spin_unlock_bh(&profile->lock);
1029         return 0;
1030 }
1031
1032 static int dasd_stats_open(struct inode *inode, struct file *file)
1033 {
1034         struct dasd_profile *profile = inode->i_private;
1035         return single_open(file, dasd_stats_show, profile);
1036 }
1037
1038 static const struct file_operations dasd_stats_raw_fops = {
1039         .owner          = THIS_MODULE,
1040         .open           = dasd_stats_open,
1041         .read           = seq_read,
1042         .llseek         = seq_lseek,
1043         .release        = single_release,
1044         .write          = dasd_stats_write,
1045 };
1046
1047 static ssize_t dasd_stats_global_write(struct file *file,
1048                                        const char __user *user_buf,
1049                                        size_t user_len, loff_t *pos)
1050 {
1051         char *buffer, *str;
1052         ssize_t rc;
1053
1054         if (user_len > 65536)
1055                 user_len = 65536;
1056         buffer = dasd_get_user_string(user_buf, user_len);
1057         if (IS_ERR(buffer))
1058                 return PTR_ERR(buffer);
1059         str = skip_spaces(buffer);
1060         rc = user_len;
1061         if (strncmp(str, "reset", 5) == 0) {
1062                 dasd_global_profile_reset();
1063         } else if (strncmp(str, "on", 2) == 0) {
1064                 dasd_global_profile_reset();
1065                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1066         } else if (strncmp(str, "off", 3) == 0) {
1067                 dasd_global_profile_level = DASD_PROFILE_OFF;
1068         } else
1069                 rc = -EINVAL;
1070         vfree(buffer);
1071         return rc;
1072 }
1073
1074 static int dasd_stats_global_show(struct seq_file *m, void *v)
1075 {
1076         if (!dasd_global_profile_level) {
1077                 seq_puts(m, "disabled\n");
1078                 return 0;
1079         }
1080         dasd_stats_seq_print(m, &dasd_global_profile_data);
1081         return 0;
1082 }
1083
1084 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1085 {
1086         return single_open(file, dasd_stats_global_show, NULL);
1087 }
1088
1089 static const struct file_operations dasd_stats_global_fops = {
1090         .owner          = THIS_MODULE,
1091         .open           = dasd_stats_global_open,
1092         .read           = seq_read,
1093         .llseek         = seq_lseek,
1094         .release        = single_release,
1095         .write          = dasd_stats_global_write,
1096 };
1097
1098 static void dasd_profile_init(struct dasd_profile *profile,
1099                               struct dentry *base_dentry)
1100 {
1101         umode_t mode;
1102         struct dentry *pde;
1103
1104         if (!base_dentry)
1105                 return;
1106         profile->dentry = NULL;
1107         profile->data = NULL;
1108         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1109         pde = debugfs_create_file("statistics", mode, base_dentry,
1110                                   profile, &dasd_stats_raw_fops);
1111         if (pde && !IS_ERR(pde))
1112                 profile->dentry = pde;
1113         return;
1114 }
1115
1116 static void dasd_profile_exit(struct dasd_profile *profile)
1117 {
1118         dasd_profile_off(profile);
1119         debugfs_remove(profile->dentry);
1120         profile->dentry = NULL;
1121 }
1122
1123 static void dasd_statistics_removeroot(void)
1124 {
1125         dasd_global_profile_level = DASD_PROFILE_OFF;
1126         debugfs_remove(dasd_global_profile_dentry);
1127         dasd_global_profile_dentry = NULL;
1128         debugfs_remove(dasd_debugfs_global_entry);
1129         debugfs_remove(dasd_debugfs_root_entry);
1130 }
1131
1132 static void dasd_statistics_createroot(void)
1133 {
1134         umode_t mode;
1135         struct dentry *pde;
1136
1137         dasd_debugfs_root_entry = NULL;
1138         dasd_debugfs_global_entry = NULL;
1139         dasd_global_profile_dentry = NULL;
1140         pde = debugfs_create_dir("dasd", NULL);
1141         if (!pde || IS_ERR(pde))
1142                 goto error;
1143         dasd_debugfs_root_entry = pde;
1144         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1145         if (!pde || IS_ERR(pde))
1146                 goto error;
1147         dasd_debugfs_global_entry = pde;
1148
1149         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1150         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1151                                   NULL, &dasd_stats_global_fops);
1152         if (!pde || IS_ERR(pde))
1153                 goto error;
1154         dasd_global_profile_dentry = pde;
1155         return;
1156
1157 error:
1158         DBF_EVENT(DBF_ERR, "%s",
1159                   "Creation of the dasd debugfs interface failed");
1160         dasd_statistics_removeroot();
1161         return;
1162 }
1163
1164 #else
1165 #define dasd_profile_start(block, cqr, req) do {} while (0)
1166 #define dasd_profile_end(block, cqr, req) do {} while (0)
1167
1168 static void dasd_statistics_createroot(void)
1169 {
1170         return;
1171 }
1172
1173 static void dasd_statistics_removeroot(void)
1174 {
1175         return;
1176 }
1177
1178 int dasd_stats_generic_show(struct seq_file *m, void *v)
1179 {
1180         seq_puts(m, "Statistics are not activated in this kernel\n");
1181         return 0;
1182 }
1183
1184 static void dasd_profile_init(struct dasd_profile *profile,
1185                               struct dentry *base_dentry)
1186 {
1187         return;
1188 }
1189
1190 static void dasd_profile_exit(struct dasd_profile *profile)
1191 {
1192         return;
1193 }
1194
1195 int dasd_profile_on(struct dasd_profile *profile)
1196 {
1197         return 0;
1198 }
1199
1200 #endif                          /* CONFIG_DASD_PROFILE */
1201
1202 /*
1203  * Allocate memory for a channel program with 'cplength' channel
1204  * command words and 'datasize' additional space. There are two
1205  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1206  * memory and 2) dasd_smalloc_request uses the static ccw memory
1207  * that gets allocated for each device.
1208  */
1209 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1210                                           int datasize,
1211                                           struct dasd_device *device)
1212 {
1213         struct dasd_ccw_req *cqr;
1214
1215         /* Sanity checks */
1216         BUG_ON(datasize > PAGE_SIZE ||
1217              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1218
1219         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1220         if (cqr == NULL)
1221                 return ERR_PTR(-ENOMEM);
1222         cqr->cpaddr = NULL;
1223         if (cplength > 0) {
1224                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1225                                       GFP_ATOMIC | GFP_DMA);
1226                 if (cqr->cpaddr == NULL) {
1227                         kfree(cqr);
1228                         return ERR_PTR(-ENOMEM);
1229                 }
1230         }
1231         cqr->data = NULL;
1232         if (datasize > 0) {
1233                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1234                 if (cqr->data == NULL) {
1235                         kfree(cqr->cpaddr);
1236                         kfree(cqr);
1237                         return ERR_PTR(-ENOMEM);
1238                 }
1239         }
1240         cqr->magic =  magic;
1241         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1242         dasd_get_device(device);
1243         return cqr;
1244 }
1245 EXPORT_SYMBOL(dasd_kmalloc_request);
1246
1247 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1248                                           int datasize,
1249                                           struct dasd_device *device)
1250 {
1251         unsigned long flags;
1252         struct dasd_ccw_req *cqr;
1253         char *data;
1254         int size;
1255
1256         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1257         if (cplength > 0)
1258                 size += cplength * sizeof(struct ccw1);
1259         if (datasize > 0)
1260                 size += datasize;
1261         spin_lock_irqsave(&device->mem_lock, flags);
1262         cqr = (struct dasd_ccw_req *)
1263                 dasd_alloc_chunk(&device->ccw_chunks, size);
1264         spin_unlock_irqrestore(&device->mem_lock, flags);
1265         if (cqr == NULL)
1266                 return ERR_PTR(-ENOMEM);
1267         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1268         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1269         cqr->cpaddr = NULL;
1270         if (cplength > 0) {
1271                 cqr->cpaddr = (struct ccw1 *) data;
1272                 data += cplength*sizeof(struct ccw1);
1273                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1274         }
1275         cqr->data = NULL;
1276         if (datasize > 0) {
1277                 cqr->data = data;
1278                 memset(cqr->data, 0, datasize);
1279         }
1280         cqr->magic = magic;
1281         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1282         dasd_get_device(device);
1283         return cqr;
1284 }
1285 EXPORT_SYMBOL(dasd_smalloc_request);
1286
1287 /*
1288  * Free memory of a channel program. This function needs to free all the
1289  * idal lists that might have been created by dasd_set_cda and the
1290  * struct dasd_ccw_req itself.
1291  */
1292 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1293 {
1294 #ifdef CONFIG_64BIT
1295         struct ccw1 *ccw;
1296
1297         /* Clear any idals used for the request. */
1298         ccw = cqr->cpaddr;
1299         do {
1300                 clear_normalized_cda(ccw);
1301         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1302 #endif
1303         kfree(cqr->cpaddr);
1304         kfree(cqr->data);
1305         kfree(cqr);
1306         dasd_put_device(device);
1307 }
1308 EXPORT_SYMBOL(dasd_kfree_request);
1309
1310 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1311 {
1312         unsigned long flags;
1313
1314         spin_lock_irqsave(&device->mem_lock, flags);
1315         dasd_free_chunk(&device->ccw_chunks, cqr);
1316         spin_unlock_irqrestore(&device->mem_lock, flags);
1317         dasd_put_device(device);
1318 }
1319 EXPORT_SYMBOL(dasd_sfree_request);
1320
1321 /*
1322  * Check discipline magic in cqr.
1323  */
1324 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1325 {
1326         struct dasd_device *device;
1327
1328         if (cqr == NULL)
1329                 return -EINVAL;
1330         device = cqr->startdev;
1331         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1332                 DBF_DEV_EVENT(DBF_WARNING, device,
1333                             " dasd_ccw_req 0x%08x magic doesn't match"
1334                             " discipline 0x%08x",
1335                             cqr->magic,
1336                             *(unsigned int *) device->discipline->name);
1337                 return -EINVAL;
1338         }
1339         return 0;
1340 }
1341
1342 /*
1343  * Terminate the current i/o and set the request to clear_pending.
1344  * Timer keeps device runnig.
1345  * ccw_device_clear can fail if the i/o subsystem
1346  * is in a bad mood.
1347  */
1348 int dasd_term_IO(struct dasd_ccw_req *cqr)
1349 {
1350         struct dasd_device *device;
1351         int retries, rc;
1352         char errorstring[ERRORLENGTH];
1353
1354         /* Check the cqr */
1355         rc = dasd_check_cqr(cqr);
1356         if (rc)
1357                 return rc;
1358         retries = 0;
1359         device = (struct dasd_device *) cqr->startdev;
1360         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1361                 rc = ccw_device_clear(device->cdev, (long) cqr);
1362                 switch (rc) {
1363                 case 0: /* termination successful */
1364                         cqr->status = DASD_CQR_CLEAR_PENDING;
1365                         cqr->stopclk = get_tod_clock();
1366                         cqr->starttime = 0;
1367                         DBF_DEV_EVENT(DBF_DEBUG, device,
1368                                       "terminate cqr %p successful",
1369                                       cqr);
1370                         break;
1371                 case -ENODEV:
1372                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1373                                       "device gone, retry");
1374                         break;
1375                 case -EIO:
1376                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1377                                       "I/O error, retry");
1378                         break;
1379                 case -EINVAL:
1380                 case -EBUSY:
1381                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1382                                       "device busy, retry later");
1383                         break;
1384                 default:
1385                         /* internal error 10 - unknown rc*/
1386                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1387                         dev_err(&device->cdev->dev, "An error occurred in the "
1388                                 "DASD device driver, reason=%s\n", errorstring);
1389                         BUG();
1390                         break;
1391                 }
1392                 retries++;
1393         }
1394         dasd_schedule_device_bh(device);
1395         return rc;
1396 }
1397 EXPORT_SYMBOL(dasd_term_IO);
1398
1399 /*
1400  * Start the i/o. This start_IO can fail if the channel is really busy.
1401  * In that case set up a timer to start the request later.
1402  */
1403 int dasd_start_IO(struct dasd_ccw_req *cqr)
1404 {
1405         struct dasd_device *device;
1406         int rc;
1407         char errorstring[ERRORLENGTH];
1408
1409         /* Check the cqr */
1410         rc = dasd_check_cqr(cqr);
1411         if (rc) {
1412                 cqr->intrc = rc;
1413                 return rc;
1414         }
1415         device = (struct dasd_device *) cqr->startdev;
1416         if (((cqr->block &&
1417               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1418              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1419             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1420                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1421                               "because of stolen lock", cqr);
1422                 cqr->status = DASD_CQR_ERROR;
1423                 cqr->intrc = -EPERM;
1424                 return -EPERM;
1425         }
1426         if (cqr->retries < 0) {
1427                 /* internal error 14 - start_IO run out of retries */
1428                 sprintf(errorstring, "14 %p", cqr);
1429                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1430                         "device driver, reason=%s\n", errorstring);
1431                 cqr->status = DASD_CQR_ERROR;
1432                 return -EIO;
1433         }
1434         cqr->startclk = get_tod_clock();
1435         cqr->starttime = jiffies;
1436         cqr->retries--;
1437         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1438                 cqr->lpm &= device->path_data.opm;
1439                 if (!cqr->lpm)
1440                         cqr->lpm = device->path_data.opm;
1441         }
1442         if (cqr->cpmode == 1) {
1443                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1444                                          (long) cqr, cqr->lpm);
1445         } else {
1446                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1447                                       (long) cqr, cqr->lpm, 0);
1448         }
1449         switch (rc) {
1450         case 0:
1451                 cqr->status = DASD_CQR_IN_IO;
1452                 break;
1453         case -EBUSY:
1454                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1455                               "start_IO: device busy, retry later");
1456                 break;
1457         case -ETIMEDOUT:
1458                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1459                               "start_IO: request timeout, retry later");
1460                 break;
1461         case -EACCES:
1462                 /* -EACCES indicates that the request used only a subset of the
1463                  * available paths and all these paths are gone. If the lpm of
1464                  * this request was only a subset of the opm (e.g. the ppm) then
1465                  * we just do a retry with all available paths.
1466                  * If we already use the full opm, something is amiss, and we
1467                  * need a full path verification.
1468                  */
1469                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1470                         DBF_DEV_EVENT(DBF_WARNING, device,
1471                                       "start_IO: selected paths gone (%x)",
1472                                       cqr->lpm);
1473                 } else if (cqr->lpm != device->path_data.opm) {
1474                         cqr->lpm = device->path_data.opm;
1475                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1476                                       "start_IO: selected paths gone,"
1477                                       " retry on all paths");
1478                 } else {
1479                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1480                                       "start_IO: all paths in opm gone,"
1481                                       " do path verification");
1482                         dasd_generic_last_path_gone(device);
1483                         device->path_data.opm = 0;
1484                         device->path_data.ppm = 0;
1485                         device->path_data.npm = 0;
1486                         device->path_data.tbvpm =
1487                                 ccw_device_get_path_mask(device->cdev);
1488                 }
1489                 break;
1490         case -ENODEV:
1491                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1492                               "start_IO: -ENODEV device gone, retry");
1493                 break;
1494         case -EIO:
1495                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1496                               "start_IO: -EIO device gone, retry");
1497                 break;
1498         case -EINVAL:
1499                 /* most likely caused in power management context */
1500                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1501                               "start_IO: -EINVAL device currently "
1502                               "not accessible");
1503                 break;
1504         default:
1505                 /* internal error 11 - unknown rc */
1506                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1507                 dev_err(&device->cdev->dev,
1508                         "An error occurred in the DASD device driver, "
1509                         "reason=%s\n", errorstring);
1510                 BUG();
1511                 break;
1512         }
1513         cqr->intrc = rc;
1514         return rc;
1515 }
1516 EXPORT_SYMBOL(dasd_start_IO);
1517
1518 /*
1519  * Timeout function for dasd devices. This is used for different purposes
1520  *  1) missing interrupt handler for normal operation
1521  *  2) delayed start of request where start_IO failed with -EBUSY
1522  *  3) timeout for missing state change interrupts
1523  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1524  * DASD_CQR_QUEUED for 2) and 3).
1525  */
1526 static void dasd_device_timeout(unsigned long ptr)
1527 {
1528         unsigned long flags;
1529         struct dasd_device *device;
1530
1531         device = (struct dasd_device *) ptr;
1532         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1533         /* re-activate request queue */
1534         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1535         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1536         dasd_schedule_device_bh(device);
1537 }
1538
1539 /*
1540  * Setup timeout for a device in jiffies.
1541  */
1542 void dasd_device_set_timer(struct dasd_device *device, int expires)
1543 {
1544         if (expires == 0)
1545                 del_timer(&device->timer);
1546         else
1547                 mod_timer(&device->timer, jiffies + expires);
1548 }
1549 EXPORT_SYMBOL(dasd_device_set_timer);
1550
1551 /*
1552  * Clear timeout for a device.
1553  */
1554 void dasd_device_clear_timer(struct dasd_device *device)
1555 {
1556         del_timer(&device->timer);
1557 }
1558 EXPORT_SYMBOL(dasd_device_clear_timer);
1559
1560 static void dasd_handle_killed_request(struct ccw_device *cdev,
1561                                        unsigned long intparm)
1562 {
1563         struct dasd_ccw_req *cqr;
1564         struct dasd_device *device;
1565
1566         if (!intparm)
1567                 return;
1568         cqr = (struct dasd_ccw_req *) intparm;
1569         if (cqr->status != DASD_CQR_IN_IO) {
1570                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1571                                 "invalid status in handle_killed_request: "
1572                                 "%02x", cqr->status);
1573                 return;
1574         }
1575
1576         device = dasd_device_from_cdev_locked(cdev);
1577         if (IS_ERR(device)) {
1578                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1579                                 "unable to get device from cdev");
1580                 return;
1581         }
1582
1583         if (!cqr->startdev ||
1584             device != cqr->startdev ||
1585             strncmp(cqr->startdev->discipline->ebcname,
1586                     (char *) &cqr->magic, 4)) {
1587                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1588                                 "invalid device in request");
1589                 dasd_put_device(device);
1590                 return;
1591         }
1592
1593         /* Schedule request to be retried. */
1594         cqr->status = DASD_CQR_QUEUED;
1595
1596         dasd_device_clear_timer(device);
1597         dasd_schedule_device_bh(device);
1598         dasd_put_device(device);
1599 }
1600
1601 void dasd_generic_handle_state_change(struct dasd_device *device)
1602 {
1603         /* First of all start sense subsystem status request. */
1604         dasd_eer_snss(device);
1605
1606         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1607         dasd_schedule_device_bh(device);
1608         if (device->block)
1609                 dasd_schedule_block_bh(device->block);
1610 }
1611 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1612
1613 /*
1614  * Interrupt handler for "normal" ssch-io based dasd devices.
1615  */
1616 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1617                       struct irb *irb)
1618 {
1619         struct dasd_ccw_req *cqr, *next;
1620         struct dasd_device *device;
1621         unsigned long long now;
1622         int expires;
1623
1624         if (IS_ERR(irb)) {
1625                 switch (PTR_ERR(irb)) {
1626                 case -EIO:
1627                         break;
1628                 case -ETIMEDOUT:
1629                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1630                                         "request timed out\n", __func__);
1631                         break;
1632                 default:
1633                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1634                                         "unknown error %ld\n", __func__,
1635                                         PTR_ERR(irb));
1636                 }
1637                 dasd_handle_killed_request(cdev, intparm);
1638                 return;
1639         }
1640
1641         now = get_tod_clock();
1642         cqr = (struct dasd_ccw_req *) intparm;
1643         /* check for conditions that should be handled immediately */
1644         if (!cqr ||
1645             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1646               scsw_cstat(&irb->scsw) == 0)) {
1647                 if (cqr)
1648                         memcpy(&cqr->irb, irb, sizeof(*irb));
1649                 device = dasd_device_from_cdev_locked(cdev);
1650                 if (IS_ERR(device))
1651                         return;
1652                 /* ignore unsolicited interrupts for DIAG discipline */
1653                 if (device->discipline == dasd_diag_discipline_pointer) {
1654                         dasd_put_device(device);
1655                         return;
1656                 }
1657                 device->discipline->dump_sense_dbf(device, irb, "int");
1658                 if (device->features & DASD_FEATURE_ERPLOG)
1659                         device->discipline->dump_sense(device, cqr, irb);
1660                 device->discipline->check_for_device_change(device, cqr, irb);
1661                 dasd_put_device(device);
1662         }
1663
1664         /* check for for attention message */
1665         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1666                 device = dasd_device_from_cdev_locked(cdev);
1667                 device->discipline->check_attention(device, irb->esw.esw1.lpum);
1668                 dasd_put_device(device);
1669         }
1670
1671         if (!cqr)
1672                 return;
1673
1674         device = (struct dasd_device *) cqr->startdev;
1675         if (!device ||
1676             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1677                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1678                                 "invalid device in request");
1679                 return;
1680         }
1681
1682         /* Check for clear pending */
1683         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1684             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1685                 cqr->status = DASD_CQR_CLEARED;
1686                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
1687                         cqr->callback_data = DASD_SLEEPON_END_TAG;
1688                 dasd_device_clear_timer(device);
1689                 wake_up(&dasd_flush_wq);
1690                 wake_up(&generic_waitq);
1691                 dasd_schedule_device_bh(device);
1692                 return;
1693         }
1694
1695         /* check status - the request might have been killed by dyn detach */
1696         if (cqr->status != DASD_CQR_IN_IO) {
1697                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1698                               "status %02x", dev_name(&cdev->dev), cqr->status);
1699                 return;
1700         }
1701
1702         next = NULL;
1703         expires = 0;
1704         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1705             scsw_cstat(&irb->scsw) == 0) {
1706                 /* request was completed successfully */
1707                 cqr->status = DASD_CQR_SUCCESS;
1708                 cqr->stopclk = now;
1709                 /* Start first request on queue if possible -> fast_io. */
1710                 if (cqr->devlist.next != &device->ccw_queue) {
1711                         next = list_entry(cqr->devlist.next,
1712                                           struct dasd_ccw_req, devlist);
1713                 }
1714         } else {  /* error */
1715                 /*
1716                  * If we don't want complex ERP for this request, then just
1717                  * reset this and retry it in the fastpath
1718                  */
1719                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1720                     cqr->retries > 0) {
1721                         if (cqr->lpm == device->path_data.opm)
1722                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1723                                               "default ERP in fastpath "
1724                                               "(%i retries left)",
1725                                               cqr->retries);
1726                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1727                                 cqr->lpm = device->path_data.opm;
1728                         cqr->status = DASD_CQR_QUEUED;
1729                         next = cqr;
1730                 } else
1731                         cqr->status = DASD_CQR_ERROR;
1732         }
1733         if (next && (next->status == DASD_CQR_QUEUED) &&
1734             (!device->stopped)) {
1735                 if (device->discipline->start_IO(next) == 0)
1736                         expires = next->expires;
1737         }
1738         if (expires != 0)
1739                 dasd_device_set_timer(device, expires);
1740         else
1741                 dasd_device_clear_timer(device);
1742         dasd_schedule_device_bh(device);
1743 }
1744 EXPORT_SYMBOL(dasd_int_handler);
1745
1746 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1747 {
1748         struct dasd_device *device;
1749
1750         device = dasd_device_from_cdev_locked(cdev);
1751
1752         if (IS_ERR(device))
1753                 goto out;
1754         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1755            device->state != device->target ||
1756            !device->discipline->check_for_device_change){
1757                 dasd_put_device(device);
1758                 goto out;
1759         }
1760         if (device->discipline->dump_sense_dbf)
1761                 device->discipline->dump_sense_dbf(device, irb, "uc");
1762         device->discipline->check_for_device_change(device, NULL, irb);
1763         dasd_put_device(device);
1764 out:
1765         return UC_TODO_RETRY;
1766 }
1767 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1768
1769 /*
1770  * If we have an error on a dasd_block layer request then we cancel
1771  * and return all further requests from the same dasd_block as well.
1772  */
1773 static void __dasd_device_recovery(struct dasd_device *device,
1774                                    struct dasd_ccw_req *ref_cqr)
1775 {
1776         struct list_head *l, *n;
1777         struct dasd_ccw_req *cqr;
1778
1779         /*
1780          * only requeue request that came from the dasd_block layer
1781          */
1782         if (!ref_cqr->block)
1783                 return;
1784
1785         list_for_each_safe(l, n, &device->ccw_queue) {
1786                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1787                 if (cqr->status == DASD_CQR_QUEUED &&
1788                     ref_cqr->block == cqr->block) {
1789                         cqr->status = DASD_CQR_CLEARED;
1790                 }
1791         }
1792 };
1793
1794 /*
1795  * Remove those ccw requests from the queue that need to be returned
1796  * to the upper layer.
1797  */
1798 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1799                                             struct list_head *final_queue)
1800 {
1801         struct list_head *l, *n;
1802         struct dasd_ccw_req *cqr;
1803
1804         /* Process request with final status. */
1805         list_for_each_safe(l, n, &device->ccw_queue) {
1806                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1807
1808                 /* Skip any non-final request. */
1809                 if (cqr->status == DASD_CQR_QUEUED ||
1810                     cqr->status == DASD_CQR_IN_IO ||
1811                     cqr->status == DASD_CQR_CLEAR_PENDING)
1812                         continue;
1813                 if (cqr->status == DASD_CQR_ERROR) {
1814                         __dasd_device_recovery(device, cqr);
1815                 }
1816                 /* Rechain finished requests to final queue */
1817                 list_move_tail(&cqr->devlist, final_queue);
1818         }
1819 }
1820
1821 /*
1822  * the cqrs from the final queue are returned to the upper layer
1823  * by setting a dasd_block state and calling the callback function
1824  */
1825 static void __dasd_device_process_final_queue(struct dasd_device *device,
1826                                               struct list_head *final_queue)
1827 {
1828         struct list_head *l, *n;
1829         struct dasd_ccw_req *cqr;
1830         struct dasd_block *block;
1831         void (*callback)(struct dasd_ccw_req *, void *data);
1832         void *callback_data;
1833         char errorstring[ERRORLENGTH];
1834
1835         list_for_each_safe(l, n, final_queue) {
1836                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1837                 list_del_init(&cqr->devlist);
1838                 block = cqr->block;
1839                 callback = cqr->callback;
1840                 callback_data = cqr->callback_data;
1841                 if (block)
1842                         spin_lock_bh(&block->queue_lock);
1843                 switch (cqr->status) {
1844                 case DASD_CQR_SUCCESS:
1845                         cqr->status = DASD_CQR_DONE;
1846                         break;
1847                 case DASD_CQR_ERROR:
1848                         cqr->status = DASD_CQR_NEED_ERP;
1849                         break;
1850                 case DASD_CQR_CLEARED:
1851                         cqr->status = DASD_CQR_TERMINATED;
1852                         break;
1853                 default:
1854                         /* internal error 12 - wrong cqr status*/
1855                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1856                         dev_err(&device->cdev->dev,
1857                                 "An error occurred in the DASD device driver, "
1858                                 "reason=%s\n", errorstring);
1859                         BUG();
1860                 }
1861                 if (cqr->callback != NULL)
1862                         (callback)(cqr, callback_data);
1863                 if (block)
1864                         spin_unlock_bh(&block->queue_lock);
1865         }
1866 }
1867
1868 /*
1869  * Take a look at the first request on the ccw queue and check
1870  * if it reached its expire time. If so, terminate the IO.
1871  */
1872 static void __dasd_device_check_expire(struct dasd_device *device)
1873 {
1874         struct dasd_ccw_req *cqr;
1875
1876         if (list_empty(&device->ccw_queue))
1877                 return;
1878         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1879         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1880             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1881                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1882                         /*
1883                          * IO in safe offline processing should not
1884                          * run out of retries
1885                          */
1886                         cqr->retries++;
1887                 }
1888                 if (device->discipline->term_IO(cqr) != 0) {
1889                         /* Hmpf, try again in 5 sec */
1890                         dev_err(&device->cdev->dev,
1891                                 "cqr %p timed out (%lus) but cannot be "
1892                                 "ended, retrying in 5 s\n",
1893                                 cqr, (cqr->expires/HZ));
1894                         cqr->expires += 5*HZ;
1895                         dasd_device_set_timer(device, 5*HZ);
1896                 } else {
1897                         dev_err(&device->cdev->dev,
1898                                 "cqr %p timed out (%lus), %i retries "
1899                                 "remaining\n", cqr, (cqr->expires/HZ),
1900                                 cqr->retries);
1901                 }
1902         }
1903 }
1904
1905 /*
1906  * Take a look at the first request on the ccw queue and check
1907  * if it needs to be started.
1908  */
1909 static void __dasd_device_start_head(struct dasd_device *device)
1910 {
1911         struct dasd_ccw_req *cqr;
1912         int rc;
1913
1914         if (list_empty(&device->ccw_queue))
1915                 return;
1916         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1917         if (cqr->status != DASD_CQR_QUEUED)
1918                 return;
1919         /* when device is stopped, return request to previous layer
1920          * exception: only the disconnect or unresumed bits are set and the
1921          * cqr is a path verification request
1922          */
1923         if (device->stopped &&
1924             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1925               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1926                 cqr->intrc = -EAGAIN;
1927                 cqr->status = DASD_CQR_CLEARED;
1928                 dasd_schedule_device_bh(device);
1929                 return;
1930         }
1931
1932         rc = device->discipline->start_IO(cqr);
1933         if (rc == 0)
1934                 dasd_device_set_timer(device, cqr->expires);
1935         else if (rc == -EACCES) {
1936                 dasd_schedule_device_bh(device);
1937         } else
1938                 /* Hmpf, try again in 1/2 sec */
1939                 dasd_device_set_timer(device, 50);
1940 }
1941
1942 static void __dasd_device_check_path_events(struct dasd_device *device)
1943 {
1944         int rc;
1945
1946         if (device->path_data.tbvpm) {
1947                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1948                                         DASD_UNRESUMED_PM))
1949                         return;
1950                 rc = device->discipline->verify_path(
1951                         device, device->path_data.tbvpm);
1952                 if (rc)
1953                         dasd_device_set_timer(device, 50);
1954                 else
1955                         device->path_data.tbvpm = 0;
1956         }
1957 };
1958
1959 /*
1960  * Go through all request on the dasd_device request queue,
1961  * terminate them on the cdev if necessary, and return them to the
1962  * submitting layer via callback.
1963  * Note:
1964  * Make sure that all 'submitting layers' still exist when
1965  * this function is called!. In other words, when 'device' is a base
1966  * device then all block layer requests must have been removed before
1967  * via dasd_flush_block_queue.
1968  */
1969 int dasd_flush_device_queue(struct dasd_device *device)
1970 {
1971         struct dasd_ccw_req *cqr, *n;
1972         int rc;
1973         struct list_head flush_queue;
1974
1975         INIT_LIST_HEAD(&flush_queue);
1976         spin_lock_irq(get_ccwdev_lock(device->cdev));
1977         rc = 0;
1978         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1979                 /* Check status and move request to flush_queue */
1980                 switch (cqr->status) {
1981                 case DASD_CQR_IN_IO:
1982                         rc = device->discipline->term_IO(cqr);
1983                         if (rc) {
1984                                 /* unable to terminate requeust */
1985                                 dev_err(&device->cdev->dev,
1986                                         "Flushing the DASD request queue "
1987                                         "failed for request %p\n", cqr);
1988                                 /* stop flush processing */
1989                                 goto finished;
1990                         }
1991                         break;
1992                 case DASD_CQR_QUEUED:
1993                         cqr->stopclk = get_tod_clock();
1994                         cqr->status = DASD_CQR_CLEARED;
1995                         break;
1996                 default: /* no need to modify the others */
1997                         break;
1998                 }
1999                 list_move_tail(&cqr->devlist, &flush_queue);
2000         }
2001 finished:
2002         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2003         /*
2004          * After this point all requests must be in state CLEAR_PENDING,
2005          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2006          * one of the others.
2007          */
2008         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2009                 wait_event(dasd_flush_wq,
2010                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2011         /*
2012          * Now set each request back to TERMINATED, DONE or NEED_ERP
2013          * and call the callback function of flushed requests
2014          */
2015         __dasd_device_process_final_queue(device, &flush_queue);
2016         return rc;
2017 }
2018 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2019
2020 /*
2021  * Acquire the device lock and process queues for the device.
2022  */
2023 static void dasd_device_tasklet(struct dasd_device *device)
2024 {
2025         struct list_head final_queue;
2026
2027         atomic_set (&device->tasklet_scheduled, 0);
2028         INIT_LIST_HEAD(&final_queue);
2029         spin_lock_irq(get_ccwdev_lock(device->cdev));
2030         /* Check expire time of first request on the ccw queue. */
2031         __dasd_device_check_expire(device);
2032         /* find final requests on ccw queue */
2033         __dasd_device_process_ccw_queue(device, &final_queue);
2034         __dasd_device_check_path_events(device);
2035         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2036         /* Now call the callback function of requests with final status */
2037         __dasd_device_process_final_queue(device, &final_queue);
2038         spin_lock_irq(get_ccwdev_lock(device->cdev));
2039         /* Now check if the head of the ccw queue needs to be started. */
2040         __dasd_device_start_head(device);
2041         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2042         if (waitqueue_active(&shutdown_waitq))
2043                 wake_up(&shutdown_waitq);
2044         dasd_put_device(device);
2045 }
2046
2047 /*
2048  * Schedules a call to dasd_tasklet over the device tasklet.
2049  */
2050 void dasd_schedule_device_bh(struct dasd_device *device)
2051 {
2052         /* Protect against rescheduling. */
2053         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2054                 return;
2055         dasd_get_device(device);
2056         tasklet_hi_schedule(&device->tasklet);
2057 }
2058 EXPORT_SYMBOL(dasd_schedule_device_bh);
2059
2060 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2061 {
2062         device->stopped |= bits;
2063 }
2064 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2065
2066 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2067 {
2068         device->stopped &= ~bits;
2069         if (!device->stopped)
2070                 wake_up(&generic_waitq);
2071 }
2072 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2073
2074 /*
2075  * Queue a request to the head of the device ccw_queue.
2076  * Start the I/O if possible.
2077  */
2078 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2079 {
2080         struct dasd_device *device;
2081         unsigned long flags;
2082
2083         device = cqr->startdev;
2084         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2085         cqr->status = DASD_CQR_QUEUED;
2086         list_add(&cqr->devlist, &device->ccw_queue);
2087         /* let the bh start the request to keep them in order */
2088         dasd_schedule_device_bh(device);
2089         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2090 }
2091 EXPORT_SYMBOL(dasd_add_request_head);
2092
2093 /*
2094  * Queue a request to the tail of the device ccw_queue.
2095  * Start the I/O if possible.
2096  */
2097 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2098 {
2099         struct dasd_device *device;
2100         unsigned long flags;
2101
2102         device = cqr->startdev;
2103         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2104         cqr->status = DASD_CQR_QUEUED;
2105         list_add_tail(&cqr->devlist, &device->ccw_queue);
2106         /* let the bh start the request to keep them in order */
2107         dasd_schedule_device_bh(device);
2108         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2109 }
2110 EXPORT_SYMBOL(dasd_add_request_tail);
2111
2112 /*
2113  * Wakeup helper for the 'sleep_on' functions.
2114  */
2115 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2116 {
2117         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2118         cqr->callback_data = DASD_SLEEPON_END_TAG;
2119         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2120         wake_up(&generic_waitq);
2121 }
2122 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2123
2124 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2125 {
2126         struct dasd_device *device;
2127         int rc;
2128
2129         device = cqr->startdev;
2130         spin_lock_irq(get_ccwdev_lock(device->cdev));
2131         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2132         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2133         return rc;
2134 }
2135
2136 /*
2137  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2138  */
2139 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2140 {
2141         struct dasd_device *device;
2142         dasd_erp_fn_t erp_fn;
2143
2144         if (cqr->status == DASD_CQR_FILLED)
2145                 return 0;
2146         device = cqr->startdev;
2147         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2148                 if (cqr->status == DASD_CQR_TERMINATED) {
2149                         device->discipline->handle_terminated_request(cqr);
2150                         return 1;
2151                 }
2152                 if (cqr->status == DASD_CQR_NEED_ERP) {
2153                         erp_fn = device->discipline->erp_action(cqr);
2154                         erp_fn(cqr);
2155                         return 1;
2156                 }
2157                 if (cqr->status == DASD_CQR_FAILED)
2158                         dasd_log_sense(cqr, &cqr->irb);
2159                 if (cqr->refers) {
2160                         __dasd_process_erp(device, cqr);
2161                         return 1;
2162                 }
2163         }
2164         return 0;
2165 }
2166
2167 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2168 {
2169         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2170                 if (cqr->refers) /* erp is not done yet */
2171                         return 1;
2172                 return ((cqr->status != DASD_CQR_DONE) &&
2173                         (cqr->status != DASD_CQR_FAILED));
2174         } else
2175                 return (cqr->status == DASD_CQR_FILLED);
2176 }
2177
2178 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2179 {
2180         struct dasd_device *device;
2181         int rc;
2182         struct list_head ccw_queue;
2183         struct dasd_ccw_req *cqr;
2184
2185         INIT_LIST_HEAD(&ccw_queue);
2186         maincqr->status = DASD_CQR_FILLED;
2187         device = maincqr->startdev;
2188         list_add(&maincqr->blocklist, &ccw_queue);
2189         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2190              cqr = list_first_entry(&ccw_queue,
2191                                     struct dasd_ccw_req, blocklist)) {
2192
2193                 if (__dasd_sleep_on_erp(cqr))
2194                         continue;
2195                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2196                         continue;
2197                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2198                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2199                         cqr->status = DASD_CQR_FAILED;
2200                         cqr->intrc = -EPERM;
2201                         continue;
2202                 }
2203                 /* Non-temporary stop condition will trigger fail fast */
2204                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2205                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2206                     (!dasd_eer_enabled(device))) {
2207                         cqr->status = DASD_CQR_FAILED;
2208                         cqr->intrc = -ENOLINK;
2209                         continue;
2210                 }
2211                 /* Don't try to start requests if device is stopped */
2212                 if (interruptible) {
2213                         rc = wait_event_interruptible(
2214                                 generic_waitq, !(device->stopped));
2215                         if (rc == -ERESTARTSYS) {
2216                                 cqr->status = DASD_CQR_FAILED;
2217                                 maincqr->intrc = rc;
2218                                 continue;
2219                         }
2220                 } else
2221                         wait_event(generic_waitq, !(device->stopped));
2222
2223                 if (!cqr->callback)
2224                         cqr->callback = dasd_wakeup_cb;
2225
2226                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2227                 dasd_add_request_tail(cqr);
2228                 if (interruptible) {
2229                         rc = wait_event_interruptible(
2230                                 generic_waitq, _wait_for_wakeup(cqr));
2231                         if (rc == -ERESTARTSYS) {
2232                                 dasd_cancel_req(cqr);
2233                                 /* wait (non-interruptible) for final status */
2234                                 wait_event(generic_waitq,
2235                                            _wait_for_wakeup(cqr));
2236                                 cqr->status = DASD_CQR_FAILED;
2237                                 maincqr->intrc = rc;
2238                                 continue;
2239                         }
2240                 } else
2241                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2242         }
2243
2244         maincqr->endclk = get_tod_clock();
2245         if ((maincqr->status != DASD_CQR_DONE) &&
2246             (maincqr->intrc != -ERESTARTSYS))
2247                 dasd_log_sense(maincqr, &maincqr->irb);
2248         if (maincqr->status == DASD_CQR_DONE)
2249                 rc = 0;
2250         else if (maincqr->intrc)
2251                 rc = maincqr->intrc;
2252         else
2253                 rc = -EIO;
2254         return rc;
2255 }
2256
2257 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2258 {
2259         struct dasd_ccw_req *cqr;
2260
2261         list_for_each_entry(cqr, ccw_queue, blocklist) {
2262                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2263                         return 0;
2264         }
2265
2266         return 1;
2267 }
2268
2269 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2270 {
2271         struct dasd_device *device;
2272         struct dasd_ccw_req *cqr, *n;
2273         int rc;
2274
2275 retry:
2276         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2277                 device = cqr->startdev;
2278                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2279                         continue;
2280
2281                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2282                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2283                         cqr->status = DASD_CQR_FAILED;
2284                         cqr->intrc = -EPERM;
2285                         continue;
2286                 }
2287                 /*Non-temporary stop condition will trigger fail fast*/
2288                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2289                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2290                     !dasd_eer_enabled(device)) {
2291                         cqr->status = DASD_CQR_FAILED;
2292                         cqr->intrc = -EAGAIN;
2293                         continue;
2294                 }
2295
2296                 /*Don't try to start requests if device is stopped*/
2297                 if (interruptible) {
2298                         rc = wait_event_interruptible(
2299                                 generic_waitq, !device->stopped);
2300                         if (rc == -ERESTARTSYS) {
2301                                 cqr->status = DASD_CQR_FAILED;
2302                                 cqr->intrc = rc;
2303                                 continue;
2304                         }
2305                 } else
2306                         wait_event(generic_waitq, !(device->stopped));
2307
2308                 if (!cqr->callback)
2309                         cqr->callback = dasd_wakeup_cb;
2310                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2311                 dasd_add_request_tail(cqr);
2312         }
2313
2314         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2315
2316         rc = 0;
2317         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2318                 /*
2319                  * for alias devices simplify error recovery and
2320                  * return to upper layer
2321                  * do not skip ERP requests
2322                  */
2323                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2324                     (cqr->status == DASD_CQR_TERMINATED ||
2325                      cqr->status == DASD_CQR_NEED_ERP))
2326                         return -EAGAIN;
2327
2328                 /* normal recovery for basedev IO */
2329                 if (__dasd_sleep_on_erp(cqr)) {
2330                         goto retry;
2331                         /* remember that ERP was needed */
2332                         rc = 1;
2333                         /* skip processing for active cqr */
2334                         if (cqr->status != DASD_CQR_TERMINATED &&
2335                             cqr->status != DASD_CQR_NEED_ERP)
2336                                 break;
2337                 }
2338         }
2339
2340         /* start ERP requests in upper loop */
2341         if (rc)
2342                 goto retry;
2343
2344         return 0;
2345 }
2346
2347 /*
2348  * Queue a request to the tail of the device ccw_queue and wait for
2349  * it's completion.
2350  */
2351 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2352 {
2353         return _dasd_sleep_on(cqr, 0);
2354 }
2355 EXPORT_SYMBOL(dasd_sleep_on);
2356
2357 /*
2358  * Start requests from a ccw_queue and wait for their completion.
2359  */
2360 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2361 {
2362         return _dasd_sleep_on_queue(ccw_queue, 0);
2363 }
2364 EXPORT_SYMBOL(dasd_sleep_on_queue);
2365
2366 /*
2367  * Queue a request to the tail of the device ccw_queue and wait
2368  * interruptible for it's completion.
2369  */
2370 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2371 {
2372         return _dasd_sleep_on(cqr, 1);
2373 }
2374 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2375
2376 /*
2377  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2378  * for eckd devices) the currently running request has to be terminated
2379  * and be put back to status queued, before the special request is added
2380  * to the head of the queue. Then the special request is waited on normally.
2381  */
2382 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2383 {
2384         struct dasd_ccw_req *cqr;
2385         int rc;
2386
2387         if (list_empty(&device->ccw_queue))
2388                 return 0;
2389         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2390         rc = device->discipline->term_IO(cqr);
2391         if (!rc)
2392                 /*
2393                  * CQR terminated because a more important request is pending.
2394                  * Undo decreasing of retry counter because this is
2395                  * not an error case.
2396                  */
2397                 cqr->retries++;
2398         return rc;
2399 }
2400
2401 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2402 {
2403         struct dasd_device *device;
2404         int rc;
2405
2406         device = cqr->startdev;
2407         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2408             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2409                 cqr->status = DASD_CQR_FAILED;
2410                 cqr->intrc = -EPERM;
2411                 return -EIO;
2412         }
2413         spin_lock_irq(get_ccwdev_lock(device->cdev));
2414         rc = _dasd_term_running_cqr(device);
2415         if (rc) {
2416                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2417                 return rc;
2418         }
2419         cqr->callback = dasd_wakeup_cb;
2420         cqr->callback_data = DASD_SLEEPON_START_TAG;
2421         cqr->status = DASD_CQR_QUEUED;
2422         /*
2423          * add new request as second
2424          * first the terminated cqr needs to be finished
2425          */
2426         list_add(&cqr->devlist, device->ccw_queue.next);
2427
2428         /* let the bh start the request to keep them in order */
2429         dasd_schedule_device_bh(device);
2430
2431         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2432
2433         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2434
2435         if (cqr->status == DASD_CQR_DONE)
2436                 rc = 0;
2437         else if (cqr->intrc)
2438                 rc = cqr->intrc;
2439         else
2440                 rc = -EIO;
2441
2442         /* kick tasklets */
2443         dasd_schedule_device_bh(device);
2444         if (device->block)
2445                 dasd_schedule_block_bh(device->block);
2446
2447         return rc;
2448 }
2449 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2450
2451 /*
2452  * Cancels a request that was started with dasd_sleep_on_req.
2453  * This is useful to timeout requests. The request will be
2454  * terminated if it is currently in i/o.
2455  * Returns 0 if request termination was successful
2456  *         negative error code if termination failed
2457  * Cancellation of a request is an asynchronous operation! The calling
2458  * function has to wait until the request is properly returned via callback.
2459  */
2460 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2461 {
2462         struct dasd_device *device = cqr->startdev;
2463         unsigned long flags;
2464         int rc;
2465
2466         rc = 0;
2467         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2468         switch (cqr->status) {
2469         case DASD_CQR_QUEUED:
2470                 /* request was not started - just set to cleared */
2471                 cqr->status = DASD_CQR_CLEARED;
2472                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2473                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2474                 break;
2475         case DASD_CQR_IN_IO:
2476                 /* request in IO - terminate IO and release again */
2477                 rc = device->discipline->term_IO(cqr);
2478                 if (rc) {
2479                         dev_err(&device->cdev->dev,
2480                                 "Cancelling request %p failed with rc=%d\n",
2481                                 cqr, rc);
2482                 } else {
2483                         cqr->stopclk = get_tod_clock();
2484                 }
2485                 break;
2486         default: /* already finished or clear pending - do nothing */
2487                 break;
2488         }
2489         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2490         dasd_schedule_device_bh(device);
2491         return rc;
2492 }
2493 EXPORT_SYMBOL(dasd_cancel_req);
2494
2495 /*
2496  * SECTION: Operations of the dasd_block layer.
2497  */
2498
2499 /*
2500  * Timeout function for dasd_block. This is used when the block layer
2501  * is waiting for something that may not come reliably, (e.g. a state
2502  * change interrupt)
2503  */
2504 static void dasd_block_timeout(unsigned long ptr)
2505 {
2506         unsigned long flags;
2507         struct dasd_block *block;
2508
2509         block = (struct dasd_block *) ptr;
2510         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2511         /* re-activate request queue */
2512         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2513         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2514         dasd_schedule_block_bh(block);
2515 }
2516
2517 /*
2518  * Setup timeout for a dasd_block in jiffies.
2519  */
2520 void dasd_block_set_timer(struct dasd_block *block, int expires)
2521 {
2522         if (expires == 0)
2523                 del_timer(&block->timer);
2524         else
2525                 mod_timer(&block->timer, jiffies + expires);
2526 }
2527 EXPORT_SYMBOL(dasd_block_set_timer);
2528
2529 /*
2530  * Clear timeout for a dasd_block.
2531  */
2532 void dasd_block_clear_timer(struct dasd_block *block)
2533 {
2534         del_timer(&block->timer);
2535 }
2536 EXPORT_SYMBOL(dasd_block_clear_timer);
2537
2538 /*
2539  * Process finished error recovery ccw.
2540  */
2541 static void __dasd_process_erp(struct dasd_device *device,
2542                                struct dasd_ccw_req *cqr)
2543 {
2544         dasd_erp_fn_t erp_fn;
2545
2546         if (cqr->status == DASD_CQR_DONE)
2547                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2548         else
2549                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2550         erp_fn = device->discipline->erp_postaction(cqr);
2551         erp_fn(cqr);
2552 }
2553
2554 /*
2555  * Fetch requests from the block device queue.
2556  */
2557 static void __dasd_process_request_queue(struct dasd_block *block)
2558 {
2559         struct request_queue *queue;
2560         struct request *req;
2561         struct dasd_ccw_req *cqr;
2562         struct dasd_device *basedev;
2563         unsigned long flags;
2564         queue = block->request_queue;
2565         basedev = block->base;
2566         /* No queue ? Then there is nothing to do. */
2567         if (queue == NULL)
2568                 return;
2569
2570         /*
2571          * We requeue request from the block device queue to the ccw
2572          * queue only in two states. In state DASD_STATE_READY the
2573          * partition detection is done and we need to requeue requests
2574          * for that. State DASD_STATE_ONLINE is normal block device
2575          * operation.
2576          */
2577         if (basedev->state < DASD_STATE_READY) {
2578                 while ((req = blk_fetch_request(block->request_queue)))
2579                         __blk_end_request_all(req, -EIO);
2580                 return;
2581         }
2582         /* Now we try to fetch requests from the request queue */
2583         while ((req = blk_peek_request(queue))) {
2584                 if (basedev->features & DASD_FEATURE_READONLY &&
2585                     rq_data_dir(req) == WRITE) {
2586                         DBF_DEV_EVENT(DBF_ERR, basedev,
2587                                       "Rejecting write request %p",
2588                                       req);
2589                         blk_start_request(req);
2590                         __blk_end_request_all(req, -EIO);
2591                         continue;
2592                 }
2593                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2594                     (basedev->features & DASD_FEATURE_FAILFAST ||
2595                      blk_noretry_request(req))) {
2596                         DBF_DEV_EVENT(DBF_ERR, basedev,
2597                                       "Rejecting failfast request %p",
2598                                       req);
2599                         blk_start_request(req);
2600                         __blk_end_request_all(req, -ETIMEDOUT);
2601                         continue;
2602                 }
2603                 cqr = basedev->discipline->build_cp(basedev, block, req);
2604                 if (IS_ERR(cqr)) {
2605                         if (PTR_ERR(cqr) == -EBUSY)
2606                                 break;  /* normal end condition */
2607                         if (PTR_ERR(cqr) == -ENOMEM)
2608                                 break;  /* terminate request queue loop */
2609                         if (PTR_ERR(cqr) == -EAGAIN) {
2610                                 /*
2611                                  * The current request cannot be build right
2612                                  * now, we have to try later. If this request
2613                                  * is the head-of-queue we stop the device
2614                                  * for 1/2 second.
2615                                  */
2616                                 if (!list_empty(&block->ccw_queue))
2617                                         break;
2618                                 spin_lock_irqsave(
2619                                         get_ccwdev_lock(basedev->cdev), flags);
2620                                 dasd_device_set_stop_bits(basedev,
2621                                                           DASD_STOPPED_PENDING);
2622                                 spin_unlock_irqrestore(
2623                                         get_ccwdev_lock(basedev->cdev), flags);
2624                                 dasd_block_set_timer(block, HZ/2);
2625                                 break;
2626                         }
2627                         DBF_DEV_EVENT(DBF_ERR, basedev,
2628                                       "CCW creation failed (rc=%ld) "
2629                                       "on request %p",
2630                                       PTR_ERR(cqr), req);
2631                         blk_start_request(req);
2632                         __blk_end_request_all(req, -EIO);
2633                         continue;
2634                 }
2635                 /*
2636                  *  Note: callback is set to dasd_return_cqr_cb in
2637                  * __dasd_block_start_head to cover erp requests as well
2638                  */
2639                 cqr->callback_data = (void *) req;
2640                 cqr->status = DASD_CQR_FILLED;
2641                 req->completion_data = cqr;
2642                 blk_start_request(req);
2643                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2644                 INIT_LIST_HEAD(&cqr->devlist);
2645                 dasd_profile_start(block, cqr, req);
2646         }
2647 }
2648
2649 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2650 {
2651         struct request *req;
2652         int status;
2653         int error = 0;
2654
2655         req = (struct request *) cqr->callback_data;
2656         dasd_profile_end(cqr->block, cqr, req);
2657         status = cqr->block->base->discipline->free_cp(cqr, req);
2658         if (status < 0)
2659                 error = status;
2660         else if (status == 0) {
2661                 if (cqr->intrc == -EPERM)
2662                         error = -EBADE;
2663                 else if (cqr->intrc == -ENOLINK ||
2664                          cqr->intrc == -ETIMEDOUT)
2665                         error = cqr->intrc;
2666                 else
2667                         error = -EIO;
2668         }
2669         __blk_end_request_all(req, error);
2670 }
2671
2672 /*
2673  * Process ccw request queue.
2674  */
2675 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2676                                            struct list_head *final_queue)
2677 {
2678         struct list_head *l, *n;
2679         struct dasd_ccw_req *cqr;
2680         dasd_erp_fn_t erp_fn;
2681         unsigned long flags;
2682         struct dasd_device *base = block->base;
2683
2684 restart:
2685         /* Process request with final status. */
2686         list_for_each_safe(l, n, &block->ccw_queue) {
2687                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2688                 if (cqr->status != DASD_CQR_DONE &&
2689                     cqr->status != DASD_CQR_FAILED &&
2690                     cqr->status != DASD_CQR_NEED_ERP &&
2691                     cqr->status != DASD_CQR_TERMINATED)
2692                         continue;
2693
2694                 if (cqr->status == DASD_CQR_TERMINATED) {
2695                         base->discipline->handle_terminated_request(cqr);
2696                         goto restart;
2697                 }
2698
2699                 /*  Process requests that may be recovered */
2700                 if (cqr->status == DASD_CQR_NEED_ERP) {
2701                         erp_fn = base->discipline->erp_action(cqr);
2702                         if (IS_ERR(erp_fn(cqr)))
2703                                 continue;
2704                         goto restart;
2705                 }
2706
2707                 /* log sense for fatal error */
2708                 if (cqr->status == DASD_CQR_FAILED) {
2709                         dasd_log_sense(cqr, &cqr->irb);
2710                 }
2711
2712                 /* First of all call extended error reporting. */
2713                 if (dasd_eer_enabled(base) &&
2714                     cqr->status == DASD_CQR_FAILED) {
2715                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2716
2717                         /* restart request  */
2718                         cqr->status = DASD_CQR_FILLED;
2719                         cqr->retries = 255;
2720                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2721                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2722                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2723                                                flags);
2724                         goto restart;
2725                 }
2726
2727                 /* Process finished ERP request. */
2728                 if (cqr->refers) {
2729                         __dasd_process_erp(base, cqr);
2730                         goto restart;
2731                 }
2732
2733                 /* Rechain finished requests to final queue */
2734                 cqr->endclk = get_tod_clock();
2735                 list_move_tail(&cqr->blocklist, final_queue);
2736         }
2737 }
2738
2739 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2740 {
2741         dasd_schedule_block_bh(cqr->block);
2742 }
2743
2744 static void __dasd_block_start_head(struct dasd_block *block)
2745 {
2746         struct dasd_ccw_req *cqr;
2747
2748         if (list_empty(&block->ccw_queue))
2749                 return;
2750         /* We allways begin with the first requests on the queue, as some
2751          * of previously started requests have to be enqueued on a
2752          * dasd_device again for error recovery.
2753          */
2754         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2755                 if (cqr->status != DASD_CQR_FILLED)
2756                         continue;
2757                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2758                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2759                         cqr->status = DASD_CQR_FAILED;
2760                         cqr->intrc = -EPERM;
2761                         dasd_schedule_block_bh(block);
2762                         continue;
2763                 }
2764                 /* Non-temporary stop condition will trigger fail fast */
2765                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2766                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2767                     (!dasd_eer_enabled(block->base))) {
2768                         cqr->status = DASD_CQR_FAILED;
2769                         cqr->intrc = -ENOLINK;
2770                         dasd_schedule_block_bh(block);
2771                         continue;
2772                 }
2773                 /* Don't try to start requests if device is stopped */
2774                 if (block->base->stopped)
2775                         return;
2776
2777                 /* just a fail safe check, should not happen */
2778                 if (!cqr->startdev)
2779                         cqr->startdev = block->base;
2780
2781                 /* make sure that the requests we submit find their way back */
2782                 cqr->callback = dasd_return_cqr_cb;
2783
2784                 dasd_add_request_tail(cqr);
2785         }
2786 }
2787
2788 /*
2789  * Central dasd_block layer routine. Takes requests from the generic
2790  * block layer request queue, creates ccw requests, enqueues them on
2791  * a dasd_device and processes ccw requests that have been returned.
2792  */
2793 static void dasd_block_tasklet(struct dasd_block *block)
2794 {
2795         struct list_head final_queue;
2796         struct list_head *l, *n;
2797         struct dasd_ccw_req *cqr;
2798
2799         atomic_set(&block->tasklet_scheduled, 0);
2800         INIT_LIST_HEAD(&final_queue);
2801         spin_lock(&block->queue_lock);
2802         /* Finish off requests on ccw queue */
2803         __dasd_process_block_ccw_queue(block, &final_queue);
2804         spin_unlock(&block->queue_lock);
2805         /* Now call the callback function of requests with final status */
2806         spin_lock_irq(&block->request_queue_lock);
2807         list_for_each_safe(l, n, &final_queue) {
2808                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2809                 list_del_init(&cqr->blocklist);
2810                 __dasd_cleanup_cqr(cqr);
2811         }
2812         spin_lock(&block->queue_lock);
2813         /* Get new request from the block device request queue */
2814         __dasd_process_request_queue(block);
2815         /* Now check if the head of the ccw queue needs to be started. */
2816         __dasd_block_start_head(block);
2817         spin_unlock(&block->queue_lock);
2818         spin_unlock_irq(&block->request_queue_lock);
2819         if (waitqueue_active(&shutdown_waitq))
2820                 wake_up(&shutdown_waitq);
2821         dasd_put_device(block->base);
2822 }
2823
2824 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2825 {
2826         wake_up(&dasd_flush_wq);
2827 }
2828
2829 /*
2830  * Requeue a request back to the block request queue
2831  * only works for block requests
2832  */
2833 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2834 {
2835         struct dasd_block *block = cqr->block;
2836         struct request *req;
2837         unsigned long flags;
2838
2839         if (!block)
2840                 return -EINVAL;
2841         spin_lock_irqsave(&block->queue_lock, flags);
2842         req = (struct request *) cqr->callback_data;
2843         blk_requeue_request(block->request_queue, req);
2844         spin_unlock_irqrestore(&block->queue_lock, flags);
2845
2846         return 0;
2847 }
2848
2849 /*
2850  * Go through all request on the dasd_block request queue, cancel them
2851  * on the respective dasd_device, and return them to the generic
2852  * block layer.
2853  */
2854 static int dasd_flush_block_queue(struct dasd_block *block)
2855 {
2856         struct dasd_ccw_req *cqr, *n;
2857         int rc, i;
2858         struct list_head flush_queue;
2859
2860         INIT_LIST_HEAD(&flush_queue);
2861         spin_lock_bh(&block->queue_lock);
2862         rc = 0;
2863 restart:
2864         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2865                 /* if this request currently owned by a dasd_device cancel it */
2866                 if (cqr->status >= DASD_CQR_QUEUED)
2867                         rc = dasd_cancel_req(cqr);
2868                 if (rc < 0)
2869                         break;
2870                 /* Rechain request (including erp chain) so it won't be
2871                  * touched by the dasd_block_tasklet anymore.
2872                  * Replace the callback so we notice when the request
2873                  * is returned from the dasd_device layer.
2874                  */
2875                 cqr->callback = _dasd_wake_block_flush_cb;
2876                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2877                         list_move_tail(&cqr->blocklist, &flush_queue);
2878                 if (i > 1)
2879                         /* moved more than one request - need to restart */
2880                         goto restart;
2881         }
2882         spin_unlock_bh(&block->queue_lock);
2883         /* Now call the callback function of flushed requests */
2884 restart_cb:
2885         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2886                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2887                 /* Process finished ERP request. */
2888                 if (cqr->refers) {
2889                         spin_lock_bh(&block->queue_lock);
2890                         __dasd_process_erp(block->base, cqr);
2891                         spin_unlock_bh(&block->queue_lock);
2892                         /* restart list_for_xx loop since dasd_process_erp
2893                          * might remove multiple elements */
2894                         goto restart_cb;
2895                 }
2896                 /* call the callback function */
2897                 spin_lock_irq(&block->request_queue_lock);
2898                 cqr->endclk = get_tod_clock();
2899                 list_del_init(&cqr->blocklist);
2900                 __dasd_cleanup_cqr(cqr);
2901                 spin_unlock_irq(&block->request_queue_lock);
2902         }
2903         return rc;
2904 }
2905
2906 /*
2907  * Schedules a call to dasd_tasklet over the device tasklet.
2908  */
2909 void dasd_schedule_block_bh(struct dasd_block *block)
2910 {
2911         /* Protect against rescheduling. */
2912         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2913                 return;
2914         /* life cycle of block is bound to it's base device */
2915         dasd_get_device(block->base);
2916         tasklet_hi_schedule(&block->tasklet);
2917 }
2918 EXPORT_SYMBOL(dasd_schedule_block_bh);
2919
2920
2921 /*
2922  * SECTION: external block device operations
2923  * (request queue handling, open, release, etc.)
2924  */
2925
2926 /*
2927  * Dasd request queue function. Called from ll_rw_blk.c
2928  */
2929 static void do_dasd_request(struct request_queue *queue)
2930 {
2931         struct dasd_block *block;
2932
2933         block = queue->queuedata;
2934         spin_lock(&block->queue_lock);
2935         /* Get new request from the block device request queue */
2936         __dasd_process_request_queue(block);
2937         /* Now check if the head of the ccw queue needs to be started. */
2938         __dasd_block_start_head(block);
2939         spin_unlock(&block->queue_lock);
2940 }
2941
2942 /*
2943  * Block timeout callback, called from the block layer
2944  *
2945  * request_queue lock is held on entry.
2946  *
2947  * Return values:
2948  * BLK_EH_RESET_TIMER if the request should be left running
2949  * BLK_EH_NOT_HANDLED if the request is handled or terminated
2950  *                    by the driver.
2951  */
2952 enum blk_eh_timer_return dasd_times_out(struct request *req)
2953 {
2954         struct dasd_ccw_req *cqr = req->completion_data;
2955         struct dasd_block *block = req->q->queuedata;
2956         struct dasd_device *device;
2957         int rc = 0;
2958
2959         if (!cqr)
2960                 return BLK_EH_NOT_HANDLED;
2961
2962         device = cqr->startdev ? cqr->startdev : block->base;
2963         if (!device->blk_timeout)
2964                 return BLK_EH_RESET_TIMER;
2965         DBF_DEV_EVENT(DBF_WARNING, device,
2966                       " dasd_times_out cqr %p status %x",
2967                       cqr, cqr->status);
2968
2969         spin_lock(&block->queue_lock);
2970         spin_lock(get_ccwdev_lock(device->cdev));
2971         cqr->retries = -1;
2972         cqr->intrc = -ETIMEDOUT;
2973         if (cqr->status >= DASD_CQR_QUEUED) {
2974                 spin_unlock(get_ccwdev_lock(device->cdev));
2975                 rc = dasd_cancel_req(cqr);
2976         } else if (cqr->status == DASD_CQR_FILLED ||
2977                    cqr->status == DASD_CQR_NEED_ERP) {
2978                 cqr->status = DASD_CQR_TERMINATED;
2979                 spin_unlock(get_ccwdev_lock(device->cdev));
2980         } else if (cqr->status == DASD_CQR_IN_ERP) {
2981                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
2982
2983                 list_for_each_entry_safe(searchcqr, nextcqr,
2984                                          &block->ccw_queue, blocklist) {
2985                         tmpcqr = searchcqr;
2986                         while (tmpcqr->refers)
2987                                 tmpcqr = tmpcqr->refers;
2988                         if (tmpcqr != cqr)
2989                                 continue;
2990                         /* searchcqr is an ERP request for cqr */
2991                         searchcqr->retries = -1;
2992                         searchcqr->intrc = -ETIMEDOUT;
2993                         if (searchcqr->status >= DASD_CQR_QUEUED) {
2994                                 spin_unlock(get_ccwdev_lock(device->cdev));
2995                                 rc = dasd_cancel_req(searchcqr);
2996                                 spin_lock(get_ccwdev_lock(device->cdev));
2997                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
2998                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
2999                                 searchcqr->status = DASD_CQR_TERMINATED;
3000                                 rc = 0;
3001                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3002                                 /*
3003                                  * Shouldn't happen; most recent ERP
3004                                  * request is at the front of queue
3005                                  */
3006                                 continue;
3007                         }
3008                         break;
3009                 }
3010                 spin_unlock(get_ccwdev_lock(device->cdev));
3011         }
3012         dasd_schedule_block_bh(block);
3013         spin_unlock(&block->queue_lock);
3014
3015         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3016 }
3017
3018 /*
3019  * Allocate and initialize request queue and default I/O scheduler.
3020  */
3021 static int dasd_alloc_queue(struct dasd_block *block)
3022 {
3023         int rc;
3024
3025         block->request_queue = blk_init_queue(do_dasd_request,
3026                                                &block->request_queue_lock);
3027         if (block->request_queue == NULL)
3028                 return -ENOMEM;
3029
3030         block->request_queue->queuedata = block;
3031
3032         elevator_exit(block->request_queue->elevator);
3033         block->request_queue->elevator = NULL;
3034         mutex_lock(&block->request_queue->sysfs_lock);
3035         rc = elevator_init(block->request_queue, "deadline");
3036         if (rc)
3037                 blk_cleanup_queue(block->request_queue);
3038         mutex_unlock(&block->request_queue->sysfs_lock);
3039         return rc;
3040 }
3041
3042 /*
3043  * Allocate and initialize request queue.
3044  */
3045 static void dasd_setup_queue(struct dasd_block *block)
3046 {
3047         int max;
3048
3049         if (block->base->features & DASD_FEATURE_USERAW) {
3050                 /*
3051                  * the max_blocks value for raw_track access is 256
3052                  * it is higher than the native ECKD value because we
3053                  * only need one ccw per track
3054                  * so the max_hw_sectors are
3055                  * 2048 x 512B = 1024kB = 16 tracks
3056                  */
3057                 max = 2048;
3058         } else {
3059                 max = block->base->discipline->max_blocks << block->s2b_shift;
3060         }
3061         blk_queue_logical_block_size(block->request_queue,
3062                                      block->bp_block);
3063         blk_queue_max_hw_sectors(block->request_queue, max);
3064         blk_queue_max_segments(block->request_queue, -1L);
3065         /* with page sized segments we can translate each segement into
3066          * one idaw/tidaw
3067          */
3068         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3069         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3070 }
3071
3072 /*
3073  * Deactivate and free request queue.
3074  */
3075 static void dasd_free_queue(struct dasd_block *block)
3076 {
3077         if (block->request_queue) {
3078                 blk_cleanup_queue(block->request_queue);
3079                 block->request_queue = NULL;
3080         }
3081 }
3082
3083 /*
3084  * Flush request on the request queue.
3085  */
3086 static void dasd_flush_request_queue(struct dasd_block *block)
3087 {
3088         struct request *req;
3089
3090         if (!block->request_queue)
3091                 return;
3092
3093         spin_lock_irq(&block->request_queue_lock);
3094         while ((req = blk_fetch_request(block->request_queue)))
3095                 __blk_end_request_all(req, -EIO);
3096         spin_unlock_irq(&block->request_queue_lock);
3097 }
3098
3099 static int dasd_open(struct block_device *bdev, fmode_t mode)
3100 {
3101         struct dasd_device *base;
3102         int rc;
3103
3104         base = dasd_device_from_gendisk(bdev->bd_disk);
3105         if (!base)
3106                 return -ENODEV;
3107
3108         atomic_inc(&base->block->open_count);
3109         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3110                 rc = -ENODEV;
3111                 goto unlock;
3112         }
3113
3114         if (!try_module_get(base->discipline->owner)) {
3115                 rc = -EINVAL;
3116                 goto unlock;
3117         }
3118
3119         if (dasd_probeonly) {
3120                 dev_info(&base->cdev->dev,
3121                          "Accessing the DASD failed because it is in "
3122                          "probeonly mode\n");
3123                 rc = -EPERM;
3124                 goto out;
3125         }
3126
3127         if (base->state <= DASD_STATE_BASIC) {
3128                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3129                               " Cannot open unrecognized device");
3130                 rc = -ENODEV;
3131                 goto out;
3132         }
3133
3134         if ((mode & FMODE_WRITE) &&
3135             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3136              (base->features & DASD_FEATURE_READONLY))) {
3137                 rc = -EROFS;
3138                 goto out;
3139         }
3140
3141         dasd_put_device(base);
3142         return 0;
3143
3144 out:
3145         module_put(base->discipline->owner);
3146 unlock:
3147         atomic_dec(&base->block->open_count);
3148         dasd_put_device(base);
3149         return rc;
3150 }
3151
3152 static void dasd_release(struct gendisk *disk, fmode_t mode)
3153 {
3154         struct dasd_device *base = dasd_device_from_gendisk(disk);
3155         if (base) {
3156                 atomic_dec(&base->block->open_count);
3157                 module_put(base->discipline->owner);
3158                 dasd_put_device(base);
3159         }
3160 }
3161
3162 /*
3163  * Return disk geometry.
3164  */
3165 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3166 {
3167         struct dasd_device *base;
3168
3169         base = dasd_device_from_gendisk(bdev->bd_disk);
3170         if (!base)
3171                 return -ENODEV;
3172
3173         if (!base->discipline ||
3174             !base->discipline->fill_geometry) {
3175                 dasd_put_device(base);
3176                 return -EINVAL;
3177         }
3178         base->discipline->fill_geometry(base->block, geo);
3179         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3180         dasd_put_device(base);
3181         return 0;
3182 }
3183
3184 const struct block_device_operations
3185 dasd_device_operations = {
3186         .owner          = THIS_MODULE,
3187         .open           = dasd_open,
3188         .release        = dasd_release,
3189         .ioctl          = dasd_ioctl,
3190         .compat_ioctl   = dasd_ioctl,
3191         .getgeo         = dasd_getgeo,
3192 };
3193
3194 /*******************************************************************************
3195  * end of block device operations
3196  */
3197
3198 static void
3199 dasd_exit(void)
3200 {
3201 #ifdef CONFIG_PROC_FS
3202         dasd_proc_exit();
3203 #endif
3204         dasd_eer_exit();
3205         if (dasd_page_cache != NULL) {
3206                 kmem_cache_destroy(dasd_page_cache);
3207                 dasd_page_cache = NULL;
3208         }
3209         dasd_gendisk_exit();
3210         dasd_devmap_exit();
3211         if (dasd_debug_area != NULL) {
3212                 debug_unregister(dasd_debug_area);
3213                 dasd_debug_area = NULL;
3214         }
3215         dasd_statistics_removeroot();
3216 }
3217
3218 /*
3219  * SECTION: common functions for ccw_driver use
3220  */
3221
3222 /*
3223  * Is the device read-only?
3224  * Note that this function does not report the setting of the
3225  * readonly device attribute, but how it is configured in z/VM.
3226  */
3227 int dasd_device_is_ro(struct dasd_device *device)
3228 {
3229         struct ccw_dev_id dev_id;
3230         struct diag210 diag_data;
3231         int rc;
3232
3233         if (!MACHINE_IS_VM)
3234                 return 0;
3235         ccw_device_get_id(device->cdev, &dev_id);
3236         memset(&diag_data, 0, sizeof(diag_data));
3237         diag_data.vrdcdvno = dev_id.devno;
3238         diag_data.vrdclen = sizeof(diag_data);
3239         rc = diag210(&diag_data);
3240         if (rc == 0 || rc == 2) {
3241                 return diag_data.vrdcvfla & 0x80;
3242         } else {
3243                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3244                           dev_id.devno, rc);
3245                 return 0;
3246         }
3247 }
3248 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3249
3250 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3251 {
3252         struct ccw_device *cdev = data;
3253         int ret;
3254
3255         ret = ccw_device_set_online(cdev);
3256         if (ret)
3257                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3258                         dev_name(&cdev->dev), ret);
3259 }
3260
3261 /*
3262  * Initial attempt at a probe function. this can be simplified once
3263  * the other detection code is gone.
3264  */
3265 int dasd_generic_probe(struct ccw_device *cdev,
3266                        struct dasd_discipline *discipline)
3267 {
3268         int ret;
3269
3270         ret = dasd_add_sysfs_files(cdev);
3271         if (ret) {
3272                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3273                                 "dasd_generic_probe: could not add "
3274                                 "sysfs entries");
3275                 return ret;
3276         }
3277         cdev->handler = &dasd_int_handler;
3278
3279         /*
3280          * Automatically online either all dasd devices (dasd_autodetect)
3281          * or all devices specified with dasd= parameters during
3282          * initial probe.
3283          */
3284         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3285             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3286                 async_schedule(dasd_generic_auto_online, cdev);
3287         return 0;
3288 }
3289 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3290
3291 /*
3292  * This will one day be called from a global not_oper handler.
3293  * It is also used by driver_unregister during module unload.
3294  */
3295 void dasd_generic_remove(struct ccw_device *cdev)
3296 {
3297         struct dasd_device *device;
3298         struct dasd_block *block;
3299
3300         cdev->handler = NULL;
3301
3302         device = dasd_device_from_cdev(cdev);
3303         if (IS_ERR(device)) {
3304                 dasd_remove_sysfs_files(cdev);
3305                 return;
3306         }
3307         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3308             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3309                 /* Already doing offline processing */
3310                 dasd_put_device(device);
3311                 dasd_remove_sysfs_files(cdev);
3312                 return;
3313         }
3314         /*
3315          * This device is removed unconditionally. Set offline
3316          * flag to prevent dasd_open from opening it while it is
3317          * no quite down yet.
3318          */
3319         dasd_set_target_state(device, DASD_STATE_NEW);
3320         /* dasd_delete_device destroys the device reference. */
3321         block = device->block;
3322         dasd_delete_device(device);
3323         /*
3324          * life cycle of block is bound to device, so delete it after
3325          * device was safely removed
3326          */
3327         if (block)
3328                 dasd_free_block(block);
3329
3330         dasd_remove_sysfs_files(cdev);
3331 }
3332 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3333
3334 /*
3335  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3336  * the device is detected for the first time and is supposed to be used
3337  * or the user has started activation through sysfs.
3338  */
3339 int dasd_generic_set_online(struct ccw_device *cdev,
3340                             struct dasd_discipline *base_discipline)
3341 {
3342         struct dasd_discipline *discipline;
3343         struct dasd_device *device;
3344         int rc;
3345
3346         /* first online clears initial online feature flag */
3347         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3348         device = dasd_create_device(cdev);
3349         if (IS_ERR(device))
3350                 return PTR_ERR(device);
3351
3352         discipline = base_discipline;
3353         if (device->features & DASD_FEATURE_USEDIAG) {
3354                 if (!dasd_diag_discipline_pointer) {
3355                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3356                                 dev_name(&cdev->dev));
3357                         dasd_delete_device(device);
3358                         return -ENODEV;
3359                 }
3360                 discipline = dasd_diag_discipline_pointer;
3361         }
3362         if (!try_module_get(base_discipline->owner)) {
3363                 dasd_delete_device(device);
3364                 return -EINVAL;
3365         }
3366         if (!try_module_get(discipline->owner)) {
3367                 module_put(base_discipline->owner);
3368                 dasd_delete_device(device);
3369                 return -EINVAL;
3370         }
3371         device->base_discipline = base_discipline;
3372         device->discipline = discipline;
3373
3374         /* check_device will allocate block device if necessary */
3375         rc = discipline->check_device(device);
3376         if (rc) {
3377                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3378                         dev_name(&cdev->dev), discipline->name, rc);
3379                 module_put(discipline->owner);
3380                 module_put(base_discipline->owner);
3381                 dasd_delete_device(device);
3382                 return rc;
3383         }
3384
3385         dasd_set_target_state(device, DASD_STATE_ONLINE);
3386         if (device->state <= DASD_STATE_KNOWN) {
3387                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3388                         dev_name(&cdev->dev));
3389                 rc = -ENODEV;
3390                 dasd_set_target_state(device, DASD_STATE_NEW);
3391                 if (device->block)
3392                         dasd_free_block(device->block);
3393                 dasd_delete_device(device);
3394         } else
3395                 pr_debug("dasd_generic device %s found\n",
3396                                 dev_name(&cdev->dev));
3397
3398         wait_event(dasd_init_waitq, _wait_for_device(device));
3399
3400         dasd_put_device(device);
3401         return rc;
3402 }
3403 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3404
3405 int dasd_generic_set_offline(struct ccw_device *cdev)
3406 {
3407         struct dasd_device *device;
3408         struct dasd_block *block;
3409         int max_count, open_count, rc;
3410
3411         rc = 0;
3412         device = dasd_device_from_cdev(cdev);
3413         if (IS_ERR(device))
3414                 return PTR_ERR(device);
3415
3416         /*
3417          * We must make sure that this device is currently not in use.
3418          * The open_count is increased for every opener, that includes
3419          * the blkdev_get in dasd_scan_partitions. We are only interested
3420          * in the other openers.
3421          */
3422         if (device->block) {
3423                 max_count = device->block->bdev ? 0 : -1;
3424                 open_count = atomic_read(&device->block->open_count);
3425                 if (open_count > max_count) {
3426                         if (open_count > 0)
3427                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3428                                         dev_name(&cdev->dev), open_count);
3429                         else
3430                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3431                                         dev_name(&cdev->dev));
3432                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3433                         dasd_put_device(device);
3434                         return -EBUSY;
3435                 }
3436         }
3437
3438         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3439                 /*
3440                  * safe offline already running
3441                  * could only be called by normal offline so safe_offline flag
3442                  * needs to be removed to run normal offline and kill all I/O
3443                  */
3444                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3445                         /* Already doing normal offline processing */
3446                         dasd_put_device(device);
3447                         return -EBUSY;
3448                 } else
3449                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3450
3451         } else
3452                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3453                         /* Already doing offline processing */
3454                         dasd_put_device(device);
3455                         return -EBUSY;
3456                 }
3457
3458         /*
3459          * if safe_offline called set safe_offline_running flag and
3460          * clear safe_offline so that a call to normal offline
3461          * can overrun safe_offline processing
3462          */
3463         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3464             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3465                 /*
3466                  * If we want to set the device safe offline all IO operations
3467                  * should be finished before continuing the offline process
3468                  * so sync bdev first and then wait for our queues to become
3469                  * empty
3470                  */
3471                 /* sync blockdev and partitions */
3472                 rc = fsync_bdev(device->block->bdev);
3473                 if (rc != 0)
3474                         goto interrupted;
3475
3476                 /* schedule device tasklet and wait for completion */
3477                 dasd_schedule_device_bh(device);
3478                 rc = wait_event_interruptible(shutdown_waitq,
3479                                               _wait_for_empty_queues(device));
3480                 if (rc != 0)
3481                         goto interrupted;
3482         }
3483
3484         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3485         dasd_set_target_state(device, DASD_STATE_NEW);
3486         /* dasd_delete_device destroys the device reference. */
3487         block = device->block;
3488         dasd_delete_device(device);
3489         /*
3490          * life cycle of block is bound to device, so delete it after
3491          * device was safely removed
3492          */
3493         if (block)
3494                 dasd_free_block(block);
3495         return 0;
3496
3497 interrupted:
3498         /* interrupted by signal */
3499         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3500         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3501         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3502         dasd_put_device(device);
3503         return rc;
3504 }
3505 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3506
3507 int dasd_generic_last_path_gone(struct dasd_device *device)
3508 {
3509         struct dasd_ccw_req *cqr;
3510
3511         dev_warn(&device->cdev->dev, "No operational channel path is left "
3512                  "for the device\n");
3513         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3514         /* First of all call extended error reporting. */
3515         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3516
3517         if (device->state < DASD_STATE_BASIC)
3518                 return 0;
3519         /* Device is active. We want to keep it. */
3520         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3521                 if ((cqr->status == DASD_CQR_IN_IO) ||
3522                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3523                         cqr->status = DASD_CQR_QUEUED;
3524                         cqr->retries++;
3525                 }
3526         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3527         dasd_device_clear_timer(device);
3528         dasd_schedule_device_bh(device);
3529         return 1;
3530 }
3531 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3532
3533 int dasd_generic_path_operational(struct dasd_device *device)
3534 {
3535         dev_info(&device->cdev->dev, "A channel path to the device has become "
3536                  "operational\n");
3537         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3538         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3539         if (device->stopped & DASD_UNRESUMED_PM) {
3540                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3541                 dasd_restore_device(device);
3542                 return 1;
3543         }
3544         dasd_schedule_device_bh(device);
3545         if (device->block)
3546                 dasd_schedule_block_bh(device->block);
3547
3548         if (!device->stopped)
3549                 wake_up(&generic_waitq);
3550
3551         return 1;
3552 }
3553 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3554
3555 int dasd_generic_notify(struct ccw_device *cdev, int event)
3556 {
3557         struct dasd_device *device;
3558         int ret;
3559
3560         device = dasd_device_from_cdev_locked(cdev);
3561         if (IS_ERR(device))
3562                 return 0;
3563         ret = 0;
3564         switch (event) {
3565         case CIO_GONE:
3566         case CIO_BOXED:
3567         case CIO_NO_PATH:
3568                 device->path_data.opm = 0;
3569                 device->path_data.ppm = 0;
3570                 device->path_data.npm = 0;
3571                 ret = dasd_generic_last_path_gone(device);
3572                 break;
3573         case CIO_OPER:
3574                 ret = 1;
3575                 if (device->path_data.opm)
3576                         ret = dasd_generic_path_operational(device);
3577                 break;
3578         }
3579         dasd_put_device(device);
3580         return ret;
3581 }
3582 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3583
3584 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3585 {
3586         int chp;
3587         __u8 oldopm, eventlpm;
3588         struct dasd_device *device;
3589
3590         device = dasd_device_from_cdev_locked(cdev);
3591         if (IS_ERR(device))
3592                 return;
3593         for (chp = 0; chp < 8; chp++) {
3594                 eventlpm = 0x80 >> chp;
3595                 if (path_event[chp] & PE_PATH_GONE) {
3596                         oldopm = device->path_data.opm;
3597                         device->path_data.opm &= ~eventlpm;
3598                         device->path_data.ppm &= ~eventlpm;
3599                         device->path_data.npm &= ~eventlpm;
3600                         if (oldopm && !device->path_data.opm) {
3601                                 dev_warn(&device->cdev->dev,
3602                                          "No verified channel paths remain "
3603                                          "for the device\n");
3604                                 DBF_DEV_EVENT(DBF_WARNING, device,
3605                                               "%s", "last verified path gone");
3606                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3607                                 dasd_device_set_stop_bits(device,
3608                                                           DASD_STOPPED_DC_WAIT);
3609                         }
3610                 }
3611                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3612                         device->path_data.opm &= ~eventlpm;
3613                         device->path_data.ppm &= ~eventlpm;
3614                         device->path_data.npm &= ~eventlpm;
3615                         device->path_data.tbvpm |= eventlpm;
3616                         dasd_schedule_device_bh(device);
3617                 }
3618                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3619                         if (!(device->path_data.opm & eventlpm) &&
3620                             !(device->path_data.tbvpm & eventlpm)) {
3621                                 /*
3622                                  * we can not establish a pathgroup on an
3623                                  * unavailable path, so trigger a path
3624                                  * verification first
3625                                  */
3626                                 device->path_data.tbvpm |= eventlpm;
3627                                 dasd_schedule_device_bh(device);
3628                         }
3629                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3630                                       "Pathgroup re-established\n");
3631                         if (device->discipline->kick_validate)
3632                                 device->discipline->kick_validate(device);
3633                 }
3634         }
3635         dasd_put_device(device);
3636 }
3637 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3638
3639 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3640 {
3641         if (!device->path_data.opm && lpm) {
3642                 device->path_data.opm = lpm;
3643                 dasd_generic_path_operational(device);
3644         } else
3645                 device->path_data.opm |= lpm;
3646         return 0;
3647 }
3648 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3649
3650
3651 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3652 {
3653         struct dasd_device *device = dasd_device_from_cdev(cdev);
3654         struct list_head freeze_queue;
3655         struct dasd_ccw_req *cqr, *n;
3656         struct dasd_ccw_req *refers;
3657         int rc;
3658
3659         if (IS_ERR(device))
3660                 return PTR_ERR(device);
3661
3662         /* mark device as suspended */
3663         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3664
3665         if (device->discipline->freeze)
3666                 rc = device->discipline->freeze(device);
3667
3668         /* disallow new I/O  */
3669         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3670
3671         /* clear active requests and requeue them to block layer if possible */
3672         INIT_LIST_HEAD(&freeze_queue);
3673         spin_lock_irq(get_ccwdev_lock(cdev));
3674         rc = 0;
3675         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3676                 /* Check status and move request to flush_queue */
3677                 if (cqr->status == DASD_CQR_IN_IO) {
3678                         rc = device->discipline->term_IO(cqr);
3679                         if (rc) {
3680                                 /* unable to terminate requeust */
3681                                 dev_err(&device->cdev->dev,
3682                                         "Unable to terminate request %p "
3683                                         "on suspend\n", cqr);
3684                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3685                                 dasd_put_device(device);
3686                                 return rc;
3687                         }
3688                 }
3689                 list_move_tail(&cqr->devlist, &freeze_queue);
3690         }
3691         spin_unlock_irq(get_ccwdev_lock(cdev));
3692
3693         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3694                 wait_event(dasd_flush_wq,
3695                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3696                 if (cqr->status == DASD_CQR_CLEARED)
3697                         cqr->status = DASD_CQR_QUEUED;
3698
3699                 /* requeue requests to blocklayer will only work for
3700                    block device requests */
3701                 if (_dasd_requeue_request(cqr))
3702                         continue;
3703
3704                 /* remove requests from device and block queue */
3705                 list_del_init(&cqr->devlist);
3706                 while (cqr->refers != NULL) {
3707                         refers = cqr->refers;
3708                         /* remove the request from the block queue */
3709                         list_del(&cqr->blocklist);
3710                         /* free the finished erp request */
3711                         dasd_free_erp_request(cqr, cqr->memdev);
3712                         cqr = refers;
3713                 }
3714                 if (cqr->block)
3715                         list_del_init(&cqr->blocklist);
3716                 cqr->block->base->discipline->free_cp(
3717                         cqr, (struct request *) cqr->callback_data);
3718         }
3719
3720         /*
3721          * if requests remain then they are internal request
3722          * and go back to the device queue
3723          */
3724         if (!list_empty(&freeze_queue)) {
3725                 /* move freeze_queue to start of the ccw_queue */
3726                 spin_lock_irq(get_ccwdev_lock(cdev));
3727                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3728                 spin_unlock_irq(get_ccwdev_lock(cdev));
3729         }
3730         dasd_put_device(device);
3731         return rc;
3732 }
3733 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3734
3735 int dasd_generic_restore_device(struct ccw_device *cdev)
3736 {
3737         struct dasd_device *device = dasd_device_from_cdev(cdev);
3738         int rc = 0;
3739
3740         if (IS_ERR(device))
3741                 return PTR_ERR(device);
3742
3743         /* allow new IO again */
3744         dasd_device_remove_stop_bits(device,
3745                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3746
3747         dasd_schedule_device_bh(device);
3748
3749         /*
3750          * call discipline restore function
3751          * if device is stopped do nothing e.g. for disconnected devices
3752          */
3753         if (device->discipline->restore && !(device->stopped))
3754                 rc = device->discipline->restore(device);
3755         if (rc || device->stopped)
3756                 /*
3757                  * if the resume failed for the DASD we put it in
3758                  * an UNRESUMED stop state
3759                  */
3760                 device->stopped |= DASD_UNRESUMED_PM;
3761
3762         if (device->block)
3763                 dasd_schedule_block_bh(device->block);
3764
3765         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3766         dasd_put_device(device);
3767         return 0;
3768 }
3769 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3770
3771 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3772                                                    void *rdc_buffer,
3773                                                    int rdc_buffer_size,
3774                                                    int magic)
3775 {
3776         struct dasd_ccw_req *cqr;
3777         struct ccw1 *ccw;
3778         unsigned long *idaw;
3779
3780         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3781
3782         if (IS_ERR(cqr)) {
3783                 /* internal error 13 - Allocating the RDC request failed*/
3784                 dev_err(&device->cdev->dev,
3785                          "An error occurred in the DASD device driver, "
3786                          "reason=%s\n", "13");
3787                 return cqr;
3788         }
3789
3790         ccw = cqr->cpaddr;
3791         ccw->cmd_code = CCW_CMD_RDC;
3792         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3793                 idaw = (unsigned long *) (cqr->data);
3794                 ccw->cda = (__u32)(addr_t) idaw;
3795                 ccw->flags = CCW_FLAG_IDA;
3796                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3797         } else {
3798                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3799                 ccw->flags = 0;
3800         }
3801
3802         ccw->count = rdc_buffer_size;
3803         cqr->startdev = device;
3804         cqr->memdev = device;
3805         cqr->expires = 10*HZ;
3806         cqr->retries = 256;
3807         cqr->buildclk = get_tod_clock();
3808         cqr->status = DASD_CQR_FILLED;
3809         return cqr;
3810 }
3811
3812
3813 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3814                                 void *rdc_buffer, int rdc_buffer_size)
3815 {
3816         int ret;
3817         struct dasd_ccw_req *cqr;
3818
3819         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3820                                      magic);
3821         if (IS_ERR(cqr))
3822                 return PTR_ERR(cqr);
3823
3824         ret = dasd_sleep_on(cqr);
3825         dasd_sfree_request(cqr, cqr->memdev);
3826         return ret;
3827 }
3828 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3829
3830 /*
3831  *   In command mode and transport mode we need to look for sense
3832  *   data in different places. The sense data itself is allways
3833  *   an array of 32 bytes, so we can unify the sense data access
3834  *   for both modes.
3835  */
3836 char *dasd_get_sense(struct irb *irb)
3837 {
3838         struct tsb *tsb = NULL;
3839         char *sense = NULL;
3840
3841         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3842                 if (irb->scsw.tm.tcw)
3843                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3844                                           irb->scsw.tm.tcw);
3845                 if (tsb && tsb->length == 64 && tsb->flags)
3846                         switch (tsb->flags & 0x07) {
3847                         case 1: /* tsa_iostat */
3848                                 sense = tsb->tsa.iostat.sense;
3849                                 break;
3850                         case 2: /* tsa_ddpc */
3851                                 sense = tsb->tsa.ddpc.sense;
3852                                 break;
3853                         default:
3854                                 /* currently we don't use interrogate data */
3855                                 break;
3856                         }
3857         } else if (irb->esw.esw0.erw.cons) {
3858                 sense = irb->ecw;
3859         }
3860         return sense;
3861 }
3862 EXPORT_SYMBOL_GPL(dasd_get_sense);
3863
3864 void dasd_generic_shutdown(struct ccw_device *cdev)
3865 {
3866         struct dasd_device *device;
3867
3868         device = dasd_device_from_cdev(cdev);
3869         if (IS_ERR(device))
3870                 return;
3871
3872         if (device->block)
3873                 dasd_schedule_block_bh(device->block);
3874
3875         dasd_schedule_device_bh(device);
3876
3877         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3878 }
3879 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3880
3881 static int __init dasd_init(void)
3882 {
3883         int rc;
3884
3885         init_waitqueue_head(&dasd_init_waitq);
3886         init_waitqueue_head(&dasd_flush_wq);
3887         init_waitqueue_head(&generic_waitq);
3888         init_waitqueue_head(&shutdown_waitq);
3889
3890         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3891         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3892         if (dasd_debug_area == NULL) {
3893                 rc = -ENOMEM;
3894                 goto failed;
3895         }
3896         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3897         debug_set_level(dasd_debug_area, DBF_WARNING);
3898
3899         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3900
3901         dasd_diag_discipline_pointer = NULL;
3902
3903         dasd_statistics_createroot();
3904
3905         rc = dasd_devmap_init();
3906         if (rc)
3907                 goto failed;
3908         rc = dasd_gendisk_init();
3909         if (rc)
3910                 goto failed;
3911         rc = dasd_parse();
3912         if (rc)
3913                 goto failed;
3914         rc = dasd_eer_init();
3915         if (rc)
3916                 goto failed;
3917 #ifdef CONFIG_PROC_FS
3918         rc = dasd_proc_init();
3919         if (rc)
3920                 goto failed;
3921 #endif
3922
3923         return 0;
3924 failed:
3925         pr_info("The DASD device driver could not be initialized\n");
3926         dasd_exit();
3927         return rc;
3928 }
3929
3930 module_init(dasd_init);
3931 module_exit(dasd_exit);