drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 #define DASD_DIAG_MOD           "dasd_diag_mod"
  42
  43 /*
  44  * SECTION: exported variables of dasd.c
  45  */
  46 debug_info_t *dasd_debug_area;
  47 EXPORT_SYMBOL(dasd_debug_area);
  48 static struct dentry *dasd_debugfs_root_entry;
  49 struct dasd_discipline *dasd_diag_discipline_pointer;
  50 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  52
  53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  55                    " Copyright IBM Corp. 2000");
  56 MODULE_SUPPORTED_DEVICE("dasd");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int  dasd_alloc_queue(struct dasd_block *);
  63 static void dasd_setup_queue(struct dasd_block *);
  64 static void dasd_free_queue(struct dasd_block *);
  65 static void dasd_flush_request_queue(struct dasd_block *);
  66 static int dasd_flush_block_queue(struct dasd_block *);
  67 static void dasd_device_tasklet(struct dasd_device *);
  68 static void dasd_block_tasklet(struct dasd_block *);
  69 static void do_kick_device(struct work_struct *);
  70 static void do_restore_device(struct work_struct *);
  71 static void do_reload_device(struct work_struct *);
  72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  73 static void dasd_device_timeout(unsigned long);
  74 static void dasd_block_timeout(unsigned long);
  75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  77 static void dasd_profile_exit(struct dasd_profile *);
  78 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  79 static void dasd_hosts_exit(struct dasd_device *);
  80
  81 /*
  82  * SECTION: Operations on the device structure.
  83  */
  84 static wait_queue_head_t dasd_init_waitq;
  85 static wait_queue_head_t dasd_flush_wq;
  86 static wait_queue_head_t generic_waitq;
  87 static wait_queue_head_t shutdown_waitq;
  88
  89 /*
  90  * Allocate memory for a new device structure.
  91  */
  92 struct dasd_device *dasd_alloc_device(void)
  93 {
  94         struct dasd_device *device;
  95
  96         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  97         if (!device)
  98                 return ERR_PTR(-ENOMEM);
  99
 100         /* Get two pages for normal block device operations. */
 101         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 102         if (!device->ccw_mem) {
 103                 kfree(device);
 104                 return ERR_PTR(-ENOMEM);
 105         }
 106         /* Get one page for error recovery. */
 107         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 108         if (!device->erp_mem) {
 109                 free_pages((unsigned long) device->ccw_mem, 1);
 110                 kfree(device);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 115         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 116         spin_lock_init(&device->mem_lock);
 117         atomic_set(&device->tasklet_scheduled, 0);
 118         tasklet_init(&device->tasklet,
 119                      (void (*)(unsigned long)) dasd_device_tasklet,
 120                      (unsigned long) device);
 121         INIT_LIST_HEAD(&device->ccw_queue);
 122         init_timer(&device->timer);
 123         device->timer.function = dasd_device_timeout;
 124         device->timer.data = (unsigned long) device;
 125         INIT_WORK(&device->kick_work, do_kick_device);
 126         INIT_WORK(&device->restore_device, do_restore_device);
 127         INIT_WORK(&device->reload_device, do_reload_device);
 128         device->state = DASD_STATE_NEW;
 129         device->target = DASD_STATE_NEW;
 130         mutex_init(&device->state_mutex);
 131         spin_lock_init(&device->profile.lock);
 132         return device;
 133 }
 134
 135 /*
 136  * Free memory of a device structure.
 137  */
 138 void dasd_free_device(struct dasd_device *device)
 139 {
 140         kfree(device->private);
 141         free_page((unsigned long) device->erp_mem);
 142         free_pages((unsigned long) device->ccw_mem, 1);
 143         kfree(device);
 144 }
 145
 146 /*
 147  * Allocate memory for a new device structure.
 148  */
 149 struct dasd_block *dasd_alloc_block(void)
 150 {
 151         struct dasd_block *block;
 152
 153         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 154         if (!block)
 155                 return ERR_PTR(-ENOMEM);
 156         /* open_count = 0 means device online but not in use */
 157         atomic_set(&block->open_count, -1);
 158
 159         spin_lock_init(&block->request_queue_lock);
 160         atomic_set(&block->tasklet_scheduled, 0);
 161         tasklet_init(&block->tasklet,
 162                      (void (*)(unsigned long)) dasd_block_tasklet,
 163                      (unsigned long) block);
 164         INIT_LIST_HEAD(&block->ccw_queue);
 165         spin_lock_init(&block->queue_lock);
 166         init_timer(&block->timer);
 167         block->timer.function = dasd_block_timeout;
 168         block->timer.data = (unsigned long) block;
 169         spin_lock_init(&block->profile.lock);
 170
 171         return block;
 172 }
 173 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 174
 175 /*
 176  * Free memory of a device structure.
 177  */
 178 void dasd_free_block(struct dasd_block *block)
 179 {
 180         kfree(block);
 181 }
 182 EXPORT_SYMBOL_GPL(dasd_free_block);
 183
 184 /*
 185  * Make a new device known to the system.
 186  */
 187 static int dasd_state_new_to_known(struct dasd_device *device)
 188 {
 189         int rc;
 190
 191         /*
 192          * As long as the device is not in state DASD_STATE_NEW we want to
 193          * keep the reference count > 0.
 194          */
 195         dasd_get_device(device);
 196
 197         if (device->block) {
 198                 rc = dasd_alloc_queue(device->block);
 199                 if (rc) {
 200                         dasd_put_device(device);
 201                         return rc;
 202                 }
 203         }
 204         device->state = DASD_STATE_KNOWN;
 205         return 0;
 206 }
 207
 208 /*
 209  * Let the system forget about a device.
 210  */
 211 static int dasd_state_known_to_new(struct dasd_device *device)
 212 {
 213         /* Disable extended error reporting for this device. */
 214         dasd_eer_disable(device);
 215         device->state = DASD_STATE_NEW;
 216
 217         if (device->block)
 218                 dasd_free_queue(device->block);
 219
 220         /* Give up reference we took in dasd_state_new_to_known. */
 221         dasd_put_device(device);
 222         return 0;
 223 }
 224
 225 static struct dentry *dasd_debugfs_setup(const char *name,
 226                                          struct dentry *base_dentry)
 227 {
 228         struct dentry *pde;
 229
 230         if (!base_dentry)
 231                 return NULL;
 232         pde = debugfs_create_dir(name, base_dentry);
 233         if (!pde || IS_ERR(pde))
 234                 return NULL;
 235         return pde;
 236 }
 237
 238 /*
 239  * Request the irq line for the device.
 240  */
 241 static int dasd_state_known_to_basic(struct dasd_device *device)
 242 {
 243         struct dasd_block *block = device->block;
 244         int rc = 0;
 245
 246         /* Allocate and register gendisk structure. */
 247         if (block) {
 248                 rc = dasd_gendisk_alloc(block);
 249                 if (rc)
 250                         return rc;
 251                 block->debugfs_dentry =
 252                         dasd_debugfs_setup(block->gdp->disk_name,
 253                                            dasd_debugfs_root_entry);
 254                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 255                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 256                         dasd_profile_on(&device->block->profile);
 257         }
 258         device->debugfs_dentry =
 259                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 260                                    dasd_debugfs_root_entry);
 261         dasd_profile_init(&device->profile, device->debugfs_dentry);
 262         dasd_hosts_init(device->debugfs_dentry, device);
 263
 264         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 265         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 266                                             8 * sizeof(long));
 267         debug_register_view(device->debug_area, &debug_sprintf_view);
 268         debug_set_level(device->debug_area, DBF_WARNING);
 269         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 270
 271         device->state = DASD_STATE_BASIC;
 272
 273         return rc;
 274 }
 275
 276 /*
 277  * Release the irq line for the device. Terminate any running i/o.
 278  */
 279 static int dasd_state_basic_to_known(struct dasd_device *device)
 280 {
 281         int rc;
 282
 283         if (device->discipline->basic_to_known) {
 284                 rc = device->discipline->basic_to_known(device);
 285                 if (rc)
 286                         return rc;
 287         }
 288
 289         if (device->block) {
 290                 dasd_profile_exit(&device->block->profile);
 291                 debugfs_remove(device->block->debugfs_dentry);
 292                 dasd_gendisk_free(device->block);
 293                 dasd_block_clear_timer(device->block);
 294         }
 295         rc = dasd_flush_device_queue(device);
 296         if (rc)
 297                 return rc;
 298         dasd_device_clear_timer(device);
 299         dasd_profile_exit(&device->profile);
 300         dasd_hosts_exit(device);
 301         debugfs_remove(device->debugfs_dentry);
 302         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 303         if (device->debug_area != NULL) {
 304                 debug_unregister(device->debug_area);
 305                 device->debug_area = NULL;
 306         }
 307         device->state = DASD_STATE_KNOWN;
 308         return 0;
 309 }
 310
 311 /*
 312  * Do the initial analysis. The do_analysis function may return
 313  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 314  * until the discipline decides to continue the startup sequence
 315  * by calling the function dasd_change_state. The eckd disciplines
 316  * uses this to start a ccw that detects the format. The completion
 317  * interrupt for this detection ccw uses the kernel event daemon to
 318  * trigger the call to dasd_change_state. All this is done in the
 319  * discipline code, see dasd_eckd.c.
 320  * After the analysis ccw is done (do_analysis returned 0) the block
 321  * device is setup.
 322  * In case the analysis returns an error, the device setup is stopped
 323  * (a fake disk was already added to allow formatting).
 324  */
 325 static int dasd_state_basic_to_ready(struct dasd_device *device)
 326 {
 327         int rc;
 328         struct dasd_block *block;
 329         struct gendisk *disk;
 330
 331         rc = 0;
 332         block = device->block;
 333         /* make disk known with correct capacity */
 334         if (block) {
 335                 if (block->base->discipline->do_analysis != NULL)
 336                         rc = block->base->discipline->do_analysis(block);
 337                 if (rc) {
 338                         if (rc != -EAGAIN) {
 339                                 device->state = DASD_STATE_UNFMT;
 340                                 disk = device->block->gdp;
 341                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 342                                                KOBJ_CHANGE);
 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         if (!schedule_work(&device->kick_work))
 583                 dasd_put_device(device);
 584 }
 585 EXPORT_SYMBOL(dasd_kick_device);
 586
 587 /*
 588  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 589  * event daemon.
 590  */
 591 static void do_reload_device(struct work_struct *work)
 592 {
 593         struct dasd_device *device = container_of(work, struct dasd_device,
 594                                                   reload_device);
 595         device->discipline->reload(device);
 596         dasd_put_device(device);
 597 }
 598
 599 void dasd_reload_device(struct dasd_device *device)
 600 {
 601         dasd_get_device(device);
 602         /* queue call to dasd_reload_device to the kernel event daemon. */
 603         if (!schedule_work(&device->reload_device))
 604                 dasd_put_device(device);
 605 }
 606 EXPORT_SYMBOL(dasd_reload_device);
 607
 608 /*
 609  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 610  * event daemon.
 611  */
 612 static void do_restore_device(struct work_struct *work)
 613 {
 614         struct dasd_device *device = container_of(work, struct dasd_device,
 615                                                   restore_device);
 616         device->cdev->drv->restore(device->cdev);
 617         dasd_put_device(device);
 618 }
 619
 620 void dasd_restore_device(struct dasd_device *device)
 621 {
 622         dasd_get_device(device);
 623         /* queue call to dasd_restore_device to the kernel event daemon. */
 624         if (!schedule_work(&device->restore_device))
 625                 dasd_put_device(device);
 626 }
 627
 628 /*
 629  * Set the target state for a device and starts the state change.
 630  */
 631 void dasd_set_target_state(struct dasd_device *device, int target)
 632 {
 633         dasd_get_device(device);
 634         mutex_lock(&device->state_mutex);
 635         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 636         if (dasd_probeonly && target > DASD_STATE_READY)
 637                 target = DASD_STATE_READY;
 638         if (device->target != target) {
 639                 if (device->state == target)
 640                         wake_up(&dasd_init_waitq);
 641                 device->target = target;
 642         }
 643         if (device->state != device->target)
 644                 dasd_change_state(device);
 645         mutex_unlock(&device->state_mutex);
 646         dasd_put_device(device);
 647 }
 648 EXPORT_SYMBOL(dasd_set_target_state);
 649
 650 /*
 651  * Enable devices with device numbers in [from..to].
 652  */
 653 static inline int _wait_for_device(struct dasd_device *device)
 654 {
 655         return (device->state == device->target);
 656 }
 657
 658 void dasd_enable_device(struct dasd_device *device)
 659 {
 660         dasd_set_target_state(device, DASD_STATE_ONLINE);
 661         if (device->state <= DASD_STATE_KNOWN)
 662                 /* No discipline for device found. */
 663                 dasd_set_target_state(device, DASD_STATE_NEW);
 664         /* Now wait for the devices to come up. */
 665         wait_event(dasd_init_waitq, _wait_for_device(device));
 666
 667         dasd_reload_device(device);
 668         if (device->discipline->kick_validate)
 669                 device->discipline->kick_validate(device);
 670 }
 671 EXPORT_SYMBOL(dasd_enable_device);
 672
 673 /*
 674  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 675  */
 676
 677 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 678
 679 #ifdef CONFIG_DASD_PROFILE
 680 struct dasd_profile dasd_global_profile = {
 681         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 682 };
 683 static struct dentry *dasd_debugfs_global_entry;
 684
 685 /*
 686  * Add profiling information for cqr before execution.
 687  */
 688 static void dasd_profile_start(struct dasd_block *block,
 689                                struct dasd_ccw_req *cqr,
 690                                struct request *req)
 691 {
 692         struct list_head *l;
 693         unsigned int counter;
 694         struct dasd_device *device;
 695
 696         /* count the length of the chanq for statistics */
 697         counter = 0;
 698         if (dasd_global_profile_level || block->profile.data)
 699                 list_for_each(l, &block->ccw_queue)
 700                         if (++counter >= 31)
 701                                 break;
 702
 703         spin_lock(&dasd_global_profile.lock);
 704         if (dasd_global_profile.data) {
 705                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 706                 if (rq_data_dir(req) == READ)
 707                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 708         }
 709         spin_unlock(&dasd_global_profile.lock);
 710
 711         spin_lock(&block->profile.lock);
 712         if (block->profile.data) {
 713                 block->profile.data->dasd_io_nr_req[counter]++;
 714                 if (rq_data_dir(req) == READ)
 715                         block->profile.data->dasd_read_nr_req[counter]++;
 716         }
 717         spin_unlock(&block->profile.lock);
 718
 719         /*
 720          * We count the request for the start device, even though it may run on
 721          * some other device due to error recovery. This way we make sure that
 722          * we count each request only once.
 723          */
 724         device = cqr->startdev;
 725         if (device->profile.data) {
 726                 counter = 1; /* request is not yet queued on the start device */
 727                 list_for_each(l, &device->ccw_queue)
 728                         if (++counter >= 31)
 729                                 break;
 730         }
 731         spin_lock(&device->profile.lock);
 732         if (device->profile.data) {
 733                 device->profile.data->dasd_io_nr_req[counter]++;
 734                 if (rq_data_dir(req) == READ)
 735                         device->profile.data->dasd_read_nr_req[counter]++;
 736         }
 737         spin_unlock(&device->profile.lock);
 738 }
 739
 740 /*
 741  * Add profiling information for cqr after execution.
 742  */
 743
 744 #define dasd_profile_counter(value, index)                         \
 745 {                                                                  \
 746         for (index = 0; index < 31 && value >> (2+index); index++) \
 747                 ;                                                  \
 748 }
 749
 750 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 751                                       int is_alias,
 752                                       int is_tpm,
 753                                       int is_read,
 754                                       long sectors,
 755                                       int sectors_ind,
 756                                       int tottime_ind,
 757                                       int tottimeps_ind,
 758                                       int strtime_ind,
 759                                       int irqtime_ind,
 760                                       int irqtimeps_ind,
 761                                       int endtime_ind)
 762 {
 763         /* in case of an overflow, reset the whole profile */
 764         if (data->dasd_io_reqs == UINT_MAX) {
 765                         memset(data, 0, sizeof(*data));
 766                         getnstimeofday(&data->starttod);
 767         }
 768         data->dasd_io_reqs++;
 769         data->dasd_io_sects += sectors;
 770         if (is_alias)
 771                 data->dasd_io_alias++;
 772         if (is_tpm)
 773                 data->dasd_io_tpm++;
 774
 775         data->dasd_io_secs[sectors_ind]++;
 776         data->dasd_io_times[tottime_ind]++;
 777         data->dasd_io_timps[tottimeps_ind]++;
 778         data->dasd_io_time1[strtime_ind]++;
 779         data->dasd_io_time2[irqtime_ind]++;
 780         data->dasd_io_time2ps[irqtimeps_ind]++;
 781         data->dasd_io_time3[endtime_ind]++;
 782
 783         if (is_read) {
 784                 data->dasd_read_reqs++;
 785                 data->dasd_read_sects += sectors;
 786                 if (is_alias)
 787                         data->dasd_read_alias++;
 788                 if (is_tpm)
 789                         data->dasd_read_tpm++;
 790                 data->dasd_read_secs[sectors_ind]++;
 791                 data->dasd_read_times[tottime_ind]++;
 792                 data->dasd_read_time1[strtime_ind]++;
 793                 data->dasd_read_time2[irqtime_ind]++;
 794                 data->dasd_read_time3[endtime_ind]++;
 795         }
 796 }
 797
 798 static void dasd_profile_end(struct dasd_block *block,
 799                              struct dasd_ccw_req *cqr,
 800                              struct request *req)
 801 {
 802         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 803         long tottimeps, sectors;
 804         struct dasd_device *device;
 805         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 806         int irqtime_ind, irqtimeps_ind, endtime_ind;
 807
 808         device = cqr->startdev;
 809         if (!(dasd_global_profile_level ||
 810               block->profile.data ||
 811               device->profile.data))
 812                 return;
 813
 814         sectors = blk_rq_sectors(req);
 815         if (!cqr->buildclk || !cqr->startclk ||
 816             !cqr->stopclk || !cqr->endclk ||
 817             !sectors)
 818                 return;
 819
 820         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 821         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 822         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 823         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 824         tottimeps = tottime / sectors;
 825
 826         dasd_profile_counter(sectors, sectors_ind);
 827         dasd_profile_counter(tottime, tottime_ind);
 828         dasd_profile_counter(tottimeps, tottimeps_ind);
 829         dasd_profile_counter(strtime, strtime_ind);
 830         dasd_profile_counter(irqtime, irqtime_ind);
 831         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 832         dasd_profile_counter(endtime, endtime_ind);
 833
 834         spin_lock(&dasd_global_profile.lock);
 835         if (dasd_global_profile.data) {
 836                 dasd_profile_end_add_data(dasd_global_profile.data,
 837                                           cqr->startdev != block->base,
 838                                           cqr->cpmode == 1,
 839                                           rq_data_dir(req) == READ,
 840                                           sectors, sectors_ind, tottime_ind,
 841                                           tottimeps_ind, strtime_ind,
 842                                           irqtime_ind, irqtimeps_ind,
 843                                           endtime_ind);
 844         }
 845         spin_unlock(&dasd_global_profile.lock);
 846
 847         spin_lock(&block->profile.lock);
 848         if (block->profile.data)
 849                 dasd_profile_end_add_data(block->profile.data,
 850                                           cqr->startdev != block->base,
 851                                           cqr->cpmode == 1,
 852                                           rq_data_dir(req) == READ,
 853                                           sectors, sectors_ind, tottime_ind,
 854                                           tottimeps_ind, strtime_ind,
 855                                           irqtime_ind, irqtimeps_ind,
 856                                           endtime_ind);
 857         spin_unlock(&block->profile.lock);
 858
 859         spin_lock(&device->profile.lock);
 860         if (device->profile.data)
 861                 dasd_profile_end_add_data(device->profile.data,
 862                                           cqr->startdev != block->base,
 863                                           cqr->cpmode == 1,
 864                                           rq_data_dir(req) == READ,
 865                                           sectors, sectors_ind, tottime_ind,
 866                                           tottimeps_ind, strtime_ind,
 867                                           irqtime_ind, irqtimeps_ind,
 868                                           endtime_ind);
 869         spin_unlock(&device->profile.lock);
 870 }
 871
 872 void dasd_profile_reset(struct dasd_profile *profile)
 873 {
 874         struct dasd_profile_info *data;
 875
 876         spin_lock_bh(&profile->lock);
 877         data = profile->data;
 878         if (!data) {
 879                 spin_unlock_bh(&profile->lock);
 880                 return;
 881         }
 882         memset(data, 0, sizeof(*data));
 883         getnstimeofday(&data->starttod);
 884         spin_unlock_bh(&profile->lock);
 885 }
 886
 887 int dasd_profile_on(struct dasd_profile *profile)
 888 {
 889         struct dasd_profile_info *data;
 890
 891         data = kzalloc(sizeof(*data), GFP_KERNEL);
 892         if (!data)
 893                 return -ENOMEM;
 894         spin_lock_bh(&profile->lock);
 895         if (profile->data) {
 896                 spin_unlock_bh(&profile->lock);
 897                 kfree(data);
 898                 return 0;
 899         }
 900         getnstimeofday(&data->starttod);
 901         profile->data = data;
 902         spin_unlock_bh(&profile->lock);
 903         return 0;
 904 }
 905
 906 void dasd_profile_off(struct dasd_profile *profile)
 907 {
 908         spin_lock_bh(&profile->lock);
 909         kfree(profile->data);
 910         profile->data = NULL;
 911         spin_unlock_bh(&profile->lock);
 912 }
 913
 914 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 915 {
 916         char *buffer;
 917
 918         buffer = vmalloc(user_len + 1);
 919         if (buffer == NULL)
 920                 return ERR_PTR(-ENOMEM);
 921         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 922                 vfree(buffer);
 923                 return ERR_PTR(-EFAULT);
 924         }
 925         /* got the string, now strip linefeed. */
 926         if (buffer[user_len - 1] == '\n')
 927                 buffer[user_len - 1] = 0;
 928         else
 929                 buffer[user_len] = 0;
 930         return buffer;
 931 }
 932
 933 static ssize_t dasd_stats_write(struct file *file,
 934                                 const char __user *user_buf,
 935                                 size_t user_len, loff_t *pos)
 936 {
 937         char *buffer, *str;
 938         int rc;
 939         struct seq_file *m = (struct seq_file *)file->private_data;
 940         struct dasd_profile *prof = m->private;
 941
 942         if (user_len > 65536)
 943                 user_len = 65536;
 944         buffer = dasd_get_user_string(user_buf, user_len);
 945         if (IS_ERR(buffer))
 946                 return PTR_ERR(buffer);
 947
 948         str = skip_spaces(buffer);
 949         rc = user_len;
 950         if (strncmp(str, "reset", 5) == 0) {
 951                 dasd_profile_reset(prof);
 952         } else if (strncmp(str, "on", 2) == 0) {
 953                 rc = dasd_profile_on(prof);
 954                 if (rc)
 955                         goto out;
 956                 rc = user_len;
 957                 if (prof == &dasd_global_profile) {
 958                         dasd_profile_reset(prof);
 959                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 960                 }
 961         } else if (strncmp(str, "off", 3) == 0) {
 962                 if (prof == &dasd_global_profile)
 963                         dasd_global_profile_level = DASD_PROFILE_OFF;
 964                 dasd_profile_off(prof);
 965         } else
 966                 rc = -EINVAL;
 967 out:
 968         vfree(buffer);
 969         return rc;
 970 }
 971
 972 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 973 {
 974         int i;
 975
 976         for (i = 0; i < 32; i++)
 977                 seq_printf(m, "%u ", array[i]);
 978         seq_putc(m, '\n');
 979 }
 980
 981 static void dasd_stats_seq_print(struct seq_file *m,
 982                                  struct dasd_profile_info *data)
 983 {
 984         seq_printf(m, "start_time %ld.%09ld\n",
 985                    data->starttod.tv_sec, data->starttod.tv_nsec);
 986         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 987         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 988         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 989         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 990         seq_puts(m, "histogram_sectors ");
 991         dasd_stats_array(m, data->dasd_io_secs);
 992         seq_puts(m, "histogram_io_times ");
 993         dasd_stats_array(m, data->dasd_io_times);
 994         seq_puts(m, "histogram_io_times_weighted ");
 995         dasd_stats_array(m, data->dasd_io_timps);
 996         seq_puts(m, "histogram_time_build_to_ssch ");
 997         dasd_stats_array(m, data->dasd_io_time1);
 998         seq_puts(m, "histogram_time_ssch_to_irq ");
 999         dasd_stats_array(m, data->dasd_io_time2);
1000         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1001         dasd_stats_array(m, data->dasd_io_time2ps);
1002         seq_puts(m, "histogram_time_irq_to_end ");
1003         dasd_stats_array(m, data->dasd_io_time3);
1004         seq_puts(m, "histogram_ccw_queue_length ");
1005         dasd_stats_array(m, data->dasd_io_nr_req);
1006         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1007         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1008         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1009         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1010         seq_puts(m, "histogram_read_sectors ");
1011         dasd_stats_array(m, data->dasd_read_secs);
1012         seq_puts(m, "histogram_read_times ");
1013         dasd_stats_array(m, data->dasd_read_times);
1014         seq_puts(m, "histogram_read_time_build_to_ssch ");
1015         dasd_stats_array(m, data->dasd_read_time1);
1016         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1017         dasd_stats_array(m, data->dasd_read_time2);
1018         seq_puts(m, "histogram_read_time_irq_to_end ");
1019         dasd_stats_array(m, data->dasd_read_time3);
1020         seq_puts(m, "histogram_read_ccw_queue_length ");
1021         dasd_stats_array(m, data->dasd_read_nr_req);
1022 }
1023
1024 static int dasd_stats_show(struct seq_file *m, void *v)
1025 {
1026         struct dasd_profile *profile;
1027         struct dasd_profile_info *data;
1028
1029         profile = m->private;
1030         spin_lock_bh(&profile->lock);
1031         data = profile->data;
1032         if (!data) {
1033                 spin_unlock_bh(&profile->lock);
1034                 seq_puts(m, "disabled\n");
1035                 return 0;
1036         }
1037         dasd_stats_seq_print(m, data);
1038         spin_unlock_bh(&profile->lock);
1039         return 0;
1040 }
1041
1042 static int dasd_stats_open(struct inode *inode, struct file *file)
1043 {
1044         struct dasd_profile *profile = inode->i_private;
1045         return single_open(file, dasd_stats_show, profile);
1046 }
1047
1048 static const struct file_operations dasd_stats_raw_fops = {
1049         .owner          = THIS_MODULE,
1050         .open           = dasd_stats_open,
1051         .read           = seq_read,
1052         .llseek         = seq_lseek,
1053         .release        = single_release,
1054         .write          = dasd_stats_write,
1055 };
1056
1057 static void dasd_profile_init(struct dasd_profile *profile,
1058                               struct dentry *base_dentry)
1059 {
1060         umode_t mode;
1061         struct dentry *pde;
1062
1063         if (!base_dentry)
1064                 return;
1065         profile->dentry = NULL;
1066         profile->data = NULL;
1067         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1068         pde = debugfs_create_file("statistics", mode, base_dentry,
1069                                   profile, &dasd_stats_raw_fops);
1070         if (pde && !IS_ERR(pde))
1071                 profile->dentry = pde;
1072         return;
1073 }
1074
1075 static void dasd_profile_exit(struct dasd_profile *profile)
1076 {
1077         dasd_profile_off(profile);
1078         debugfs_remove(profile->dentry);
1079         profile->dentry = NULL;
1080 }
1081
1082 static void dasd_statistics_removeroot(void)
1083 {
1084         dasd_global_profile_level = DASD_PROFILE_OFF;
1085         dasd_profile_exit(&dasd_global_profile);
1086         debugfs_remove(dasd_debugfs_global_entry);
1087         debugfs_remove(dasd_debugfs_root_entry);
1088 }
1089
1090 static void dasd_statistics_createroot(void)
1091 {
1092         struct dentry *pde;
1093
1094         dasd_debugfs_root_entry = NULL;
1095         pde = debugfs_create_dir("dasd", NULL);
1096         if (!pde || IS_ERR(pde))
1097                 goto error;
1098         dasd_debugfs_root_entry = pde;
1099         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1100         if (!pde || IS_ERR(pde))
1101                 goto error;
1102         dasd_debugfs_global_entry = pde;
1103         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1104         return;
1105
1106 error:
1107         DBF_EVENT(DBF_ERR, "%s",
1108                   "Creation of the dasd debugfs interface failed");
1109         dasd_statistics_removeroot();
1110         return;
1111 }
1112
1113 #else
1114 #define dasd_profile_start(block, cqr, req) do {} while (0)
1115 #define dasd_profile_end(block, cqr, req) do {} while (0)
1116
1117 static void dasd_statistics_createroot(void)
1118 {
1119         return;
1120 }
1121
1122 static void dasd_statistics_removeroot(void)
1123 {
1124         return;
1125 }
1126
1127 int dasd_stats_generic_show(struct seq_file *m, void *v)
1128 {
1129         seq_puts(m, "Statistics are not activated in this kernel\n");
1130         return 0;
1131 }
1132
1133 static void dasd_profile_init(struct dasd_profile *profile,
1134                               struct dentry *base_dentry)
1135 {
1136         return;
1137 }
1138
1139 static void dasd_profile_exit(struct dasd_profile *profile)
1140 {
1141         return;
1142 }
1143
1144 int dasd_profile_on(struct dasd_profile *profile)
1145 {
1146         return 0;
1147 }
1148
1149 #endif                          /* CONFIG_DASD_PROFILE */
1150
1151 static int dasd_hosts_show(struct seq_file *m, void *v)
1152 {
1153         struct dasd_device *device;
1154         int rc = -EOPNOTSUPP;
1155
1156         device = m->private;
1157         dasd_get_device(device);
1158
1159         if (device->discipline->hosts_print)
1160                 rc = device->discipline->hosts_print(device, m);
1161
1162         dasd_put_device(device);
1163         return rc;
1164 }
1165
1166 static int dasd_hosts_open(struct inode *inode, struct file *file)
1167 {
1168         struct dasd_device *device = inode->i_private;
1169
1170         return single_open(file, dasd_hosts_show, device);
1171 }
1172
1173 static const struct file_operations dasd_hosts_fops = {
1174         .owner          = THIS_MODULE,
1175         .open           = dasd_hosts_open,
1176         .read           = seq_read,
1177         .llseek         = seq_lseek,
1178         .release        = single_release,
1179 };
1180
1181 static void dasd_hosts_exit(struct dasd_device *device)
1182 {
1183         debugfs_remove(device->hosts_dentry);
1184         device->hosts_dentry = NULL;
1185 }
1186
1187 static void dasd_hosts_init(struct dentry *base_dentry,
1188                             struct dasd_device *device)
1189 {
1190         struct dentry *pde;
1191         umode_t mode;
1192
1193         if (!base_dentry)
1194                 return;
1195
1196         mode = S_IRUSR | S_IFREG;
1197         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1198                                   device, &dasd_hosts_fops);
1199         if (pde && !IS_ERR(pde))
1200                 device->hosts_dentry = pde;
1201 }
1202
1203 /*
1204  * Allocate memory for a channel program with 'cplength' channel
1205  * command words and 'datasize' additional space. There are two
1206  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1207  * memory and 2) dasd_smalloc_request uses the static ccw memory
1208  * that gets allocated for each device.
1209  */
1210 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1211                                           int datasize,
1212                                           struct dasd_device *device)
1213 {
1214         struct dasd_ccw_req *cqr;
1215
1216         /* Sanity checks */
1217         BUG_ON(datasize > PAGE_SIZE ||
1218              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1219
1220         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1221         if (cqr == NULL)
1222                 return ERR_PTR(-ENOMEM);
1223         cqr->cpaddr = NULL;
1224         if (cplength > 0) {
1225                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1226                                       GFP_ATOMIC | GFP_DMA);
1227                 if (cqr->cpaddr == NULL) {
1228                         kfree(cqr);
1229                         return ERR_PTR(-ENOMEM);
1230                 }
1231         }
1232         cqr->data = NULL;
1233         if (datasize > 0) {
1234                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1235                 if (cqr->data == NULL) {
1236                         kfree(cqr->cpaddr);
1237                         kfree(cqr);
1238                         return ERR_PTR(-ENOMEM);
1239                 }
1240         }
1241         cqr->magic =  magic;
1242         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1243         dasd_get_device(device);
1244         return cqr;
1245 }
1246 EXPORT_SYMBOL(dasd_kmalloc_request);
1247
1248 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1249                                           int datasize,
1250                                           struct dasd_device *device)
1251 {
1252         unsigned long flags;
1253         struct dasd_ccw_req *cqr;
1254         char *data;
1255         int size;
1256
1257         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1258         if (cplength > 0)
1259                 size += cplength * sizeof(struct ccw1);
1260         if (datasize > 0)
1261                 size += datasize;
1262         spin_lock_irqsave(&device->mem_lock, flags);
1263         cqr = (struct dasd_ccw_req *)
1264                 dasd_alloc_chunk(&device->ccw_chunks, size);
1265         spin_unlock_irqrestore(&device->mem_lock, flags);
1266         if (cqr == NULL)
1267                 return ERR_PTR(-ENOMEM);
1268         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1269         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1270         cqr->cpaddr = NULL;
1271         if (cplength > 0) {
1272                 cqr->cpaddr = (struct ccw1 *) data;
1273                 data += cplength*sizeof(struct ccw1);
1274                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1275         }
1276         cqr->data = NULL;
1277         if (datasize > 0) {
1278                 cqr->data = data;
1279                 memset(cqr->data, 0, datasize);
1280         }
1281         cqr->magic = magic;
1282         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1283         dasd_get_device(device);
1284         return cqr;
1285 }
1286 EXPORT_SYMBOL(dasd_smalloc_request);
1287
1288 /*
1289  * Free memory of a channel program. This function needs to free all the
1290  * idal lists that might have been created by dasd_set_cda and the
1291  * struct dasd_ccw_req itself.
1292  */
1293 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1294 {
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         kfree(cqr->cpaddr);
1303         kfree(cqr->data);
1304         kfree(cqr);
1305         dasd_put_device(device);
1306 }
1307 EXPORT_SYMBOL(dasd_kfree_request);
1308
1309 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1310 {
1311         unsigned long flags;
1312
1313         spin_lock_irqsave(&device->mem_lock, flags);
1314         dasd_free_chunk(&device->ccw_chunks, cqr);
1315         spin_unlock_irqrestore(&device->mem_lock, flags);
1316         dasd_put_device(device);
1317 }
1318 EXPORT_SYMBOL(dasd_sfree_request);
1319
1320 /*
1321  * Check discipline magic in cqr.
1322  */
1323 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1324 {
1325         struct dasd_device *device;
1326
1327         if (cqr == NULL)
1328                 return -EINVAL;
1329         device = cqr->startdev;
1330         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1331                 DBF_DEV_EVENT(DBF_WARNING, device,
1332                             " dasd_ccw_req 0x%08x magic doesn't match"
1333                             " discipline 0x%08x",
1334                             cqr->magic,
1335                             *(unsigned int *) device->discipline->name);
1336                 return -EINVAL;
1337         }
1338         return 0;
1339 }
1340
1341 /*
1342  * Terminate the current i/o and set the request to clear_pending.
1343  * Timer keeps device runnig.
1344  * ccw_device_clear can fail if the i/o subsystem
1345  * is in a bad mood.
1346  */
1347 int dasd_term_IO(struct dasd_ccw_req *cqr)
1348 {
1349         struct dasd_device *device;
1350         int retries, rc;
1351         char errorstring[ERRORLENGTH];
1352
1353         /* Check the cqr */
1354         rc = dasd_check_cqr(cqr);
1355         if (rc)
1356                 return rc;
1357         retries = 0;
1358         device = (struct dasd_device *) cqr->startdev;
1359         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1360                 rc = ccw_device_clear(device->cdev, (long) cqr);
1361                 switch (rc) {
1362                 case 0: /* termination successful */
1363                         cqr->status = DASD_CQR_CLEAR_PENDING;
1364                         cqr->stopclk = get_tod_clock();
1365                         cqr->starttime = 0;
1366                         DBF_DEV_EVENT(DBF_DEBUG, device,
1367                                       "terminate cqr %p successful",
1368                                       cqr);
1369                         break;
1370                 case -ENODEV:
1371                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1372                                       "device gone, retry");
1373                         break;
1374                 case -EIO:
1375                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1376                                       "I/O error, retry");
1377                         break;
1378                 case -EINVAL:
1379                         /*
1380                          * device not valid so no I/O could be running
1381                          * handle CQR as termination successful
1382                          */
1383                         cqr->status = DASD_CQR_CLEARED;
1384                         cqr->stopclk = get_tod_clock();
1385                         cqr->starttime = 0;
1386                         /* no retries for invalid devices */
1387                         cqr->retries = -1;
1388                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1389                                       "EINVAL, handle as terminated");
1390                         /* fake rc to success */
1391                         rc = 0;
1392                         break;
1393                 case -EBUSY:
1394                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1395                                       "device busy, retry later");
1396                         break;
1397                 default:
1398                         /* internal error 10 - unknown rc*/
1399                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1400                         dev_err(&device->cdev->dev, "An error occurred in the "
1401                                 "DASD device driver, reason=%s\n", errorstring);
1402                         BUG();
1403                         break;
1404                 }
1405                 retries++;
1406         }
1407         dasd_schedule_device_bh(device);
1408         return rc;
1409 }
1410 EXPORT_SYMBOL(dasd_term_IO);
1411
1412 /*
1413  * Start the i/o. This start_IO can fail if the channel is really busy.
1414  * In that case set up a timer to start the request later.
1415  */
1416 int dasd_start_IO(struct dasd_ccw_req *cqr)
1417 {
1418         struct dasd_device *device;
1419         int rc;
1420         char errorstring[ERRORLENGTH];
1421
1422         /* Check the cqr */
1423         rc = dasd_check_cqr(cqr);
1424         if (rc) {
1425                 cqr->intrc = rc;
1426                 return rc;
1427         }
1428         device = (struct dasd_device *) cqr->startdev;
1429         if (((cqr->block &&
1430               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1431              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1432             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1433                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1434                               "because of stolen lock", cqr);
1435                 cqr->status = DASD_CQR_ERROR;
1436                 cqr->intrc = -EPERM;
1437                 return -EPERM;
1438         }
1439         if (cqr->retries < 0) {
1440                 /* internal error 14 - start_IO run out of retries */
1441                 sprintf(errorstring, "14 %p", cqr);
1442                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1443                         "device driver, reason=%s\n", errorstring);
1444                 cqr->status = DASD_CQR_ERROR;
1445                 return -EIO;
1446         }
1447         cqr->startclk = get_tod_clock();
1448         cqr->starttime = jiffies;
1449         cqr->retries--;
1450         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1451                 cqr->lpm &= device->path_data.opm;
1452                 if (!cqr->lpm)
1453                         cqr->lpm = device->path_data.opm;
1454         }
1455         if (cqr->cpmode == 1) {
1456                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1457                                          (long) cqr, cqr->lpm);
1458         } else {
1459                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1460                                       (long) cqr, cqr->lpm, 0);
1461         }
1462         switch (rc) {
1463         case 0:
1464                 cqr->status = DASD_CQR_IN_IO;
1465                 break;
1466         case -EBUSY:
1467                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1468                               "start_IO: device busy, retry later");
1469                 break;
1470         case -ETIMEDOUT:
1471                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1472                               "start_IO: request timeout, retry later");
1473                 break;
1474         case -EACCES:
1475                 /* -EACCES indicates that the request used only a subset of the
1476                  * available paths and all these paths are gone. If the lpm of
1477                  * this request was only a subset of the opm (e.g. the ppm) then
1478                  * we just do a retry with all available paths.
1479                  * If we already use the full opm, something is amiss, and we
1480                  * need a full path verification.
1481                  */
1482                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1483                         DBF_DEV_EVENT(DBF_WARNING, device,
1484                                       "start_IO: selected paths gone (%x)",
1485                                       cqr->lpm);
1486                 } else if (cqr->lpm != device->path_data.opm) {
1487                         cqr->lpm = device->path_data.opm;
1488                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1489                                       "start_IO: selected paths gone,"
1490                                       " retry on all paths");
1491                 } else {
1492                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1493                                       "start_IO: all paths in opm gone,"
1494                                       " do path verification");
1495                         dasd_generic_last_path_gone(device);
1496                         device->path_data.opm = 0;
1497                         device->path_data.ppm = 0;
1498                         device->path_data.npm = 0;
1499                         device->path_data.tbvpm =
1500                                 ccw_device_get_path_mask(device->cdev);
1501                 }
1502                 break;
1503         case -ENODEV:
1504                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1505                               "start_IO: -ENODEV device gone, retry");
1506                 break;
1507         case -EIO:
1508                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1509                               "start_IO: -EIO device gone, retry");
1510                 break;
1511         case -EINVAL:
1512                 /* most likely caused in power management context */
1513                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1514                               "start_IO: -EINVAL device currently "
1515                               "not accessible");
1516                 break;
1517         default:
1518                 /* internal error 11 - unknown rc */
1519                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1520                 dev_err(&device->cdev->dev,
1521                         "An error occurred in the DASD device driver, "
1522                         "reason=%s\n", errorstring);
1523                 BUG();
1524                 break;
1525         }
1526         cqr->intrc = rc;
1527         return rc;
1528 }
1529 EXPORT_SYMBOL(dasd_start_IO);
1530
1531 /*
1532  * Timeout function for dasd devices. This is used for different purposes
1533  *  1) missing interrupt handler for normal operation
1534  *  2) delayed start of request where start_IO failed with -EBUSY
1535  *  3) timeout for missing state change interrupts
1536  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1537  * DASD_CQR_QUEUED for 2) and 3).
1538  */
1539 static void dasd_device_timeout(unsigned long ptr)
1540 {
1541         unsigned long flags;
1542         struct dasd_device *device;
1543
1544         device = (struct dasd_device *) ptr;
1545         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1546         /* re-activate request queue */
1547         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1548         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1549         dasd_schedule_device_bh(device);
1550 }
1551
1552 /*
1553  * Setup timeout for a device in jiffies.
1554  */
1555 void dasd_device_set_timer(struct dasd_device *device, int expires)
1556 {
1557         if (expires == 0)
1558                 del_timer(&device->timer);
1559         else
1560                 mod_timer(&device->timer, jiffies + expires);
1561 }
1562 EXPORT_SYMBOL(dasd_device_set_timer);
1563
1564 /*
1565  * Clear timeout for a device.
1566  */
1567 void dasd_device_clear_timer(struct dasd_device *device)
1568 {
1569         del_timer(&device->timer);
1570 }
1571 EXPORT_SYMBOL(dasd_device_clear_timer);
1572
1573 static void dasd_handle_killed_request(struct ccw_device *cdev,
1574                                        unsigned long intparm)
1575 {
1576         struct dasd_ccw_req *cqr;
1577         struct dasd_device *device;
1578
1579         if (!intparm)
1580                 return;
1581         cqr = (struct dasd_ccw_req *) intparm;
1582         if (cqr->status != DASD_CQR_IN_IO) {
1583                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1584                                 "invalid status in handle_killed_request: "
1585                                 "%02x", cqr->status);
1586                 return;
1587         }
1588
1589         device = dasd_device_from_cdev_locked(cdev);
1590         if (IS_ERR(device)) {
1591                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1592                                 "unable to get device from cdev");
1593                 return;
1594         }
1595
1596         if (!cqr->startdev ||
1597             device != cqr->startdev ||
1598             strncmp(cqr->startdev->discipline->ebcname,
1599                     (char *) &cqr->magic, 4)) {
1600                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1601                                 "invalid device in request");
1602                 dasd_put_device(device);
1603                 return;
1604         }
1605
1606         /* Schedule request to be retried. */
1607         cqr->status = DASD_CQR_QUEUED;
1608
1609         dasd_device_clear_timer(device);
1610         dasd_schedule_device_bh(device);
1611         dasd_put_device(device);
1612 }
1613
1614 void dasd_generic_handle_state_change(struct dasd_device *device)
1615 {
1616         /* First of all start sense subsystem status request. */
1617         dasd_eer_snss(device);
1618
1619         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1620         dasd_schedule_device_bh(device);
1621         if (device->block)
1622                 dasd_schedule_block_bh(device->block);
1623 }
1624 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1625
1626 /*
1627  * Interrupt handler for "normal" ssch-io based dasd devices.
1628  */
1629 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1630                       struct irb *irb)
1631 {
1632         struct dasd_ccw_req *cqr, *next;
1633         struct dasd_device *device;
1634         unsigned long long now;
1635         int nrf_suppressed = 0;
1636         int fp_suppressed = 0;
1637         u8 *sense = NULL;
1638         int expires;
1639
1640         cqr = (struct dasd_ccw_req *) intparm;
1641         if (IS_ERR(irb)) {
1642                 switch (PTR_ERR(irb)) {
1643                 case -EIO:
1644                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1645                                 device = (struct dasd_device *) cqr->startdev;
1646                                 cqr->status = DASD_CQR_CLEARED;
1647                                 dasd_device_clear_timer(device);
1648                                 wake_up(&dasd_flush_wq);
1649                                 dasd_schedule_device_bh(device);
1650                                 return;
1651                         }
1652                         break;
1653                 case -ETIMEDOUT:
1654                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1655                                         "request timed out\n", __func__);
1656                         break;
1657                 default:
1658                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1659                                         "unknown error %ld\n", __func__,
1660                                         PTR_ERR(irb));
1661                 }
1662                 dasd_handle_killed_request(cdev, intparm);
1663                 return;
1664         }
1665
1666         now = get_tod_clock();
1667         /* check for conditions that should be handled immediately */
1668         if (!cqr ||
1669             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1670               scsw_cstat(&irb->scsw) == 0)) {
1671                 if (cqr)
1672                         memcpy(&cqr->irb, irb, sizeof(*irb));
1673                 device = dasd_device_from_cdev_locked(cdev);
1674                 if (IS_ERR(device))
1675                         return;
1676                 /* ignore unsolicited interrupts for DIAG discipline */
1677                 if (device->discipline == dasd_diag_discipline_pointer) {
1678                         dasd_put_device(device);
1679                         return;
1680                 }
1681
1682                 /*
1683                  * In some cases 'File Protected' or 'No Record Found' errors
1684                  * might be expected and debug log messages for the
1685                  * corresponding interrupts shouldn't be written then.
1686                  * Check if either of the according suppress bits is set.
1687                  */
1688                 sense = dasd_get_sense(irb);
1689                 if (sense) {
1690                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1691                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1692                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1693                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1694                 }
1695                 if (!(fp_suppressed || nrf_suppressed))
1696                         device->discipline->dump_sense_dbf(device, irb, "int");
1697
1698                 if (device->features & DASD_FEATURE_ERPLOG)
1699                         device->discipline->dump_sense(device, cqr, irb);
1700                 device->discipline->check_for_device_change(device, cqr, irb);
1701                 dasd_put_device(device);
1702         }
1703
1704         /* check for for attention message */
1705         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1706                 device = dasd_device_from_cdev_locked(cdev);
1707                 device->discipline->check_attention(device, irb->esw.esw1.lpum);
1708                 dasd_put_device(device);
1709         }
1710
1711         if (!cqr)
1712                 return;
1713
1714         device = (struct dasd_device *) cqr->startdev;
1715         if (!device ||
1716             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1717                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1718                                 "invalid device in request");
1719                 return;
1720         }
1721
1722         /* Check for clear pending */
1723         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1724             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1725                 cqr->status = DASD_CQR_CLEARED;
1726                 dasd_device_clear_timer(device);
1727                 wake_up(&dasd_flush_wq);
1728                 dasd_schedule_device_bh(device);
1729                 return;
1730         }
1731
1732         /* check status - the request might have been killed by dyn detach */
1733         if (cqr->status != DASD_CQR_IN_IO) {
1734                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1735                               "status %02x", dev_name(&cdev->dev), cqr->status);
1736                 return;
1737         }
1738
1739         next = NULL;
1740         expires = 0;
1741         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1742             scsw_cstat(&irb->scsw) == 0) {
1743                 /* request was completed successfully */
1744                 cqr->status = DASD_CQR_SUCCESS;
1745                 cqr->stopclk = now;
1746                 /* Start first request on queue if possible -> fast_io. */
1747                 if (cqr->devlist.next != &device->ccw_queue) {
1748                         next = list_entry(cqr->devlist.next,
1749                                           struct dasd_ccw_req, devlist);
1750                 }
1751         } else {  /* error */
1752                 /*
1753                  * If we don't want complex ERP for this request, then just
1754                  * reset this and retry it in the fastpath
1755                  */
1756                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1757                     cqr->retries > 0) {
1758                         if (cqr->lpm == device->path_data.opm)
1759                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1760                                               "default ERP in fastpath "
1761                                               "(%i retries left)",
1762                                               cqr->retries);
1763                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1764                                 cqr->lpm = device->path_data.opm;
1765                         cqr->status = DASD_CQR_QUEUED;
1766                         next = cqr;
1767                 } else
1768                         cqr->status = DASD_CQR_ERROR;
1769         }
1770         if (next && (next->status == DASD_CQR_QUEUED) &&
1771             (!device->stopped)) {
1772                 if (device->discipline->start_IO(next) == 0)
1773                         expires = next->expires;
1774         }
1775         if (expires != 0)
1776                 dasd_device_set_timer(device, expires);
1777         else
1778                 dasd_device_clear_timer(device);
1779         dasd_schedule_device_bh(device);
1780 }
1781 EXPORT_SYMBOL(dasd_int_handler);
1782
1783 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1784 {
1785         struct dasd_device *device;
1786
1787         device = dasd_device_from_cdev_locked(cdev);
1788
1789         if (IS_ERR(device))
1790                 goto out;
1791         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1792            device->state != device->target ||
1793            !device->discipline->check_for_device_change){
1794                 dasd_put_device(device);
1795                 goto out;
1796         }
1797         if (device->discipline->dump_sense_dbf)
1798                 device->discipline->dump_sense_dbf(device, irb, "uc");
1799         device->discipline->check_for_device_change(device, NULL, irb);
1800         dasd_put_device(device);
1801 out:
1802         return UC_TODO_RETRY;
1803 }
1804 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1805
1806 /*
1807  * If we have an error on a dasd_block layer request then we cancel
1808  * and return all further requests from the same dasd_block as well.
1809  */
1810 static void __dasd_device_recovery(struct dasd_device *device,
1811                                    struct dasd_ccw_req *ref_cqr)
1812 {
1813         struct list_head *l, *n;
1814         struct dasd_ccw_req *cqr;
1815
1816         /*
1817          * only requeue request that came from the dasd_block layer
1818          */
1819         if (!ref_cqr->block)
1820                 return;
1821
1822         list_for_each_safe(l, n, &device->ccw_queue) {
1823                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1824                 if (cqr->status == DASD_CQR_QUEUED &&
1825                     ref_cqr->block == cqr->block) {
1826                         cqr->status = DASD_CQR_CLEARED;
1827                 }
1828         }
1829 };
1830
1831 /*
1832  * Remove those ccw requests from the queue that need to be returned
1833  * to the upper layer.
1834  */
1835 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1836                                             struct list_head *final_queue)
1837 {
1838         struct list_head *l, *n;
1839         struct dasd_ccw_req *cqr;
1840
1841         /* Process request with final status. */
1842         list_for_each_safe(l, n, &device->ccw_queue) {
1843                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1844
1845                 /* Skip any non-final request. */
1846                 if (cqr->status == DASD_CQR_QUEUED ||
1847                     cqr->status == DASD_CQR_IN_IO ||
1848                     cqr->status == DASD_CQR_CLEAR_PENDING)
1849                         continue;
1850                 if (cqr->status == DASD_CQR_ERROR) {
1851                         __dasd_device_recovery(device, cqr);
1852                 }
1853                 /* Rechain finished requests to final queue */
1854                 list_move_tail(&cqr->devlist, final_queue);
1855         }
1856 }
1857
1858 /*
1859  * the cqrs from the final queue are returned to the upper layer
1860  * by setting a dasd_block state and calling the callback function
1861  */
1862 static void __dasd_device_process_final_queue(struct dasd_device *device,
1863                                               struct list_head *final_queue)
1864 {
1865         struct list_head *l, *n;
1866         struct dasd_ccw_req *cqr;
1867         struct dasd_block *block;
1868         void (*callback)(struct dasd_ccw_req *, void *data);
1869         void *callback_data;
1870         char errorstring[ERRORLENGTH];
1871
1872         list_for_each_safe(l, n, final_queue) {
1873                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1874                 list_del_init(&cqr->devlist);
1875                 block = cqr->block;
1876                 callback = cqr->callback;
1877                 callback_data = cqr->callback_data;
1878                 if (block)
1879                         spin_lock_bh(&block->queue_lock);
1880                 switch (cqr->status) {
1881                 case DASD_CQR_SUCCESS:
1882                         cqr->status = DASD_CQR_DONE;
1883                         break;
1884                 case DASD_CQR_ERROR:
1885                         cqr->status = DASD_CQR_NEED_ERP;
1886                         break;
1887                 case DASD_CQR_CLEARED:
1888                         cqr->status = DASD_CQR_TERMINATED;
1889                         break;
1890                 default:
1891                         /* internal error 12 - wrong cqr status*/
1892                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1893                         dev_err(&device->cdev->dev,
1894                                 "An error occurred in the DASD device driver, "
1895                                 "reason=%s\n", errorstring);
1896                         BUG();
1897                 }
1898                 if (cqr->callback != NULL)
1899                         (callback)(cqr, callback_data);
1900                 if (block)
1901                         spin_unlock_bh(&block->queue_lock);
1902         }
1903 }
1904
1905 /*
1906  * Take a look at the first request on the ccw queue and check
1907  * if it reached its expire time. If so, terminate the IO.
1908  */
1909 static void __dasd_device_check_expire(struct dasd_device *device)
1910 {
1911         struct dasd_ccw_req *cqr;
1912
1913         if (list_empty(&device->ccw_queue))
1914                 return;
1915         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1916         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1917             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1918                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1919                         /*
1920                          * IO in safe offline processing should not
1921                          * run out of retries
1922                          */
1923                         cqr->retries++;
1924                 }
1925                 if (device->discipline->term_IO(cqr) != 0) {
1926                         /* Hmpf, try again in 5 sec */
1927                         dev_err(&device->cdev->dev,
1928                                 "cqr %p timed out (%lus) but cannot be "
1929                                 "ended, retrying in 5 s\n",
1930                                 cqr, (cqr->expires/HZ));
1931                         cqr->expires += 5*HZ;
1932                         dasd_device_set_timer(device, 5*HZ);
1933                 } else {
1934                         dev_err(&device->cdev->dev,
1935                                 "cqr %p timed out (%lus), %i retries "
1936                                 "remaining\n", cqr, (cqr->expires/HZ),
1937                                 cqr->retries);
1938                 }
1939         }
1940 }
1941
1942 /*
1943  * return 1 when device is not eligible for IO
1944  */
1945 static int __dasd_device_is_unusable(struct dasd_device *device,
1946                                      struct dasd_ccw_req *cqr)
1947 {
1948         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1949
1950         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1951                 /* dasd is being set offline. */
1952                 return 1;
1953         }
1954         if (device->stopped) {
1955                 if (device->stopped & mask) {
1956                         /* stopped and CQR will not change that. */
1957                         return 1;
1958                 }
1959                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1960                         /* CQR is not able to change device to
1961                          * operational. */
1962                         return 1;
1963                 }
1964                 /* CQR required to get device operational. */
1965         }
1966         return 0;
1967 }
1968
1969 /*
1970  * Take a look at the first request on the ccw queue and check
1971  * if it needs to be started.
1972  */
1973 static void __dasd_device_start_head(struct dasd_device *device)
1974 {
1975         struct dasd_ccw_req *cqr;
1976         int rc;
1977
1978         if (list_empty(&device->ccw_queue))
1979                 return;
1980         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1981         if (cqr->status != DASD_CQR_QUEUED)
1982                 return;
1983         /* if device is not usable return request to upper layer */
1984         if (__dasd_device_is_unusable(device, cqr)) {
1985                 cqr->intrc = -EAGAIN;
1986                 cqr->status = DASD_CQR_CLEARED;
1987                 dasd_schedule_device_bh(device);
1988                 return;
1989         }
1990
1991         rc = device->discipline->start_IO(cqr);
1992         if (rc == 0)
1993                 dasd_device_set_timer(device, cqr->expires);
1994         else if (rc == -EACCES) {
1995                 dasd_schedule_device_bh(device);
1996         } else
1997                 /* Hmpf, try again in 1/2 sec */
1998                 dasd_device_set_timer(device, 50);
1999 }
2000
2001 static void __dasd_device_check_path_events(struct dasd_device *device)
2002 {
2003         int rc;
2004
2005         if (device->path_data.tbvpm) {
2006                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
2007                                         DASD_UNRESUMED_PM))
2008                         return;
2009                 rc = device->discipline->verify_path(
2010                         device, device->path_data.tbvpm);
2011                 if (rc)
2012                         dasd_device_set_timer(device, 50);
2013                 else
2014                         device->path_data.tbvpm = 0;
2015         }
2016 };
2017
2018 /*
2019  * Go through all request on the dasd_device request queue,
2020  * terminate them on the cdev if necessary, and return them to the
2021  * submitting layer via callback.
2022  * Note:
2023  * Make sure that all 'submitting layers' still exist when
2024  * this function is called!. In other words, when 'device' is a base
2025  * device then all block layer requests must have been removed before
2026  * via dasd_flush_block_queue.
2027  */
2028 int dasd_flush_device_queue(struct dasd_device *device)
2029 {
2030         struct dasd_ccw_req *cqr, *n;
2031         int rc;
2032         struct list_head flush_queue;
2033
2034         INIT_LIST_HEAD(&flush_queue);
2035         spin_lock_irq(get_ccwdev_lock(device->cdev));
2036         rc = 0;
2037         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2038                 /* Check status and move request to flush_queue */
2039                 switch (cqr->status) {
2040                 case DASD_CQR_IN_IO:
2041                         rc = device->discipline->term_IO(cqr);
2042                         if (rc) {
2043                                 /* unable to terminate requeust */
2044                                 dev_err(&device->cdev->dev,
2045                                         "Flushing the DASD request queue "
2046                                         "failed for request %p\n", cqr);
2047                                 /* stop flush processing */
2048                                 goto finished;
2049                         }
2050                         break;
2051                 case DASD_CQR_QUEUED:
2052                         cqr->stopclk = get_tod_clock();
2053                         cqr->status = DASD_CQR_CLEARED;
2054                         break;
2055                 default: /* no need to modify the others */
2056                         break;
2057                 }
2058                 list_move_tail(&cqr->devlist, &flush_queue);
2059         }
2060 finished:
2061         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2062         /*
2063          * After this point all requests must be in state CLEAR_PENDING,
2064          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2065          * one of the others.
2066          */
2067         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2068                 wait_event(dasd_flush_wq,
2069                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2070         /*
2071          * Now set each request back to TERMINATED, DONE or NEED_ERP
2072          * and call the callback function of flushed requests
2073          */
2074         __dasd_device_process_final_queue(device, &flush_queue);
2075         return rc;
2076 }
2077 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2078
2079 /*
2080  * Acquire the device lock and process queues for the device.
2081  */
2082 static void dasd_device_tasklet(struct dasd_device *device)
2083 {
2084         struct list_head final_queue;
2085
2086         atomic_set (&device->tasklet_scheduled, 0);
2087         INIT_LIST_HEAD(&final_queue);
2088         spin_lock_irq(get_ccwdev_lock(device->cdev));
2089         /* Check expire time of first request on the ccw queue. */
2090         __dasd_device_check_expire(device);
2091         /* find final requests on ccw queue */
2092         __dasd_device_process_ccw_queue(device, &final_queue);
2093         __dasd_device_check_path_events(device);
2094         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2095         /* Now call the callback function of requests with final status */
2096         __dasd_device_process_final_queue(device, &final_queue);
2097         spin_lock_irq(get_ccwdev_lock(device->cdev));
2098         /* Now check if the head of the ccw queue needs to be started. */
2099         __dasd_device_start_head(device);
2100         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2101         if (waitqueue_active(&shutdown_waitq))
2102                 wake_up(&shutdown_waitq);
2103         dasd_put_device(device);
2104 }
2105
2106 /*
2107  * Schedules a call to dasd_tasklet over the device tasklet.
2108  */
2109 void dasd_schedule_device_bh(struct dasd_device *device)
2110 {
2111         /* Protect against rescheduling. */
2112         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2113                 return;
2114         dasd_get_device(device);
2115         tasklet_hi_schedule(&device->tasklet);
2116 }
2117 EXPORT_SYMBOL(dasd_schedule_device_bh);
2118
2119 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2120 {
2121         device->stopped |= bits;
2122 }
2123 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2124
2125 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2126 {
2127         device->stopped &= ~bits;
2128         if (!device->stopped)
2129                 wake_up(&generic_waitq);
2130 }
2131 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2132
2133 /*
2134  * Queue a request to the head of the device ccw_queue.
2135  * Start the I/O if possible.
2136  */
2137 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2138 {
2139         struct dasd_device *device;
2140         unsigned long flags;
2141
2142         device = cqr->startdev;
2143         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2144         cqr->status = DASD_CQR_QUEUED;
2145         list_add(&cqr->devlist, &device->ccw_queue);
2146         /* let the bh start the request to keep them in order */
2147         dasd_schedule_device_bh(device);
2148         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2149 }
2150 EXPORT_SYMBOL(dasd_add_request_head);
2151
2152 /*
2153  * Queue a request to the tail of the device ccw_queue.
2154  * Start the I/O if possible.
2155  */
2156 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2157 {
2158         struct dasd_device *device;
2159         unsigned long flags;
2160
2161         device = cqr->startdev;
2162         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2163         cqr->status = DASD_CQR_QUEUED;
2164         list_add_tail(&cqr->devlist, &device->ccw_queue);
2165         /* let the bh start the request to keep them in order */
2166         dasd_schedule_device_bh(device);
2167         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2168 }
2169 EXPORT_SYMBOL(dasd_add_request_tail);
2170
2171 /*
2172  * Wakeup helper for the 'sleep_on' functions.
2173  */
2174 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2175 {
2176         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2177         cqr->callback_data = DASD_SLEEPON_END_TAG;
2178         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2179         wake_up(&generic_waitq);
2180 }
2181 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2182
2183 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2184 {
2185         struct dasd_device *device;
2186         int rc;
2187
2188         device = cqr->startdev;
2189         spin_lock_irq(get_ccwdev_lock(device->cdev));
2190         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2191         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2192         return rc;
2193 }
2194
2195 /*
2196  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2197  */
2198 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2199 {
2200         struct dasd_device *device;
2201         dasd_erp_fn_t erp_fn;
2202
2203         if (cqr->status == DASD_CQR_FILLED)
2204                 return 0;
2205         device = cqr->startdev;
2206         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2207                 if (cqr->status == DASD_CQR_TERMINATED) {
2208                         device->discipline->handle_terminated_request(cqr);
2209                         return 1;
2210                 }
2211                 if (cqr->status == DASD_CQR_NEED_ERP) {
2212                         erp_fn = device->discipline->erp_action(cqr);
2213                         erp_fn(cqr);
2214                         return 1;
2215                 }
2216                 if (cqr->status == DASD_CQR_FAILED)
2217                         dasd_log_sense(cqr, &cqr->irb);
2218                 if (cqr->refers) {
2219                         __dasd_process_erp(device, cqr);
2220                         return 1;
2221                 }
2222         }
2223         return 0;
2224 }
2225
2226 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2227 {
2228         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2229                 if (cqr->refers) /* erp is not done yet */
2230                         return 1;
2231                 return ((cqr->status != DASD_CQR_DONE) &&
2232                         (cqr->status != DASD_CQR_FAILED));
2233         } else
2234                 return (cqr->status == DASD_CQR_FILLED);
2235 }
2236
2237 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2238 {
2239         struct dasd_device *device;
2240         int rc;
2241         struct list_head ccw_queue;
2242         struct dasd_ccw_req *cqr;
2243
2244         INIT_LIST_HEAD(&ccw_queue);
2245         maincqr->status = DASD_CQR_FILLED;
2246         device = maincqr->startdev;
2247         list_add(&maincqr->blocklist, &ccw_queue);
2248         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2249              cqr = list_first_entry(&ccw_queue,
2250                                     struct dasd_ccw_req, blocklist)) {
2251
2252                 if (__dasd_sleep_on_erp(cqr))
2253                         continue;
2254                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2255                         continue;
2256                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2257                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2258                         cqr->status = DASD_CQR_FAILED;
2259                         cqr->intrc = -EPERM;
2260                         continue;
2261                 }
2262                 /* Non-temporary stop condition will trigger fail fast */
2263                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2264                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2265                     (!dasd_eer_enabled(device))) {
2266                         cqr->status = DASD_CQR_FAILED;
2267                         cqr->intrc = -ENOLINK;
2268                         continue;
2269                 }
2270                 /*
2271                  * Don't try to start requests if device is in
2272                  * offline processing, it might wait forever
2273                  */
2274                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2275                         cqr->status = DASD_CQR_FAILED;
2276                         cqr->intrc = -ENODEV;
2277                         continue;
2278                 }
2279                 /*
2280                  * Don't try to start requests if device is stopped
2281                  * except path verification requests
2282                  */
2283                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2284                         if (interruptible) {
2285                                 rc = wait_event_interruptible(
2286                                         generic_waitq, !(device->stopped));
2287                                 if (rc == -ERESTARTSYS) {
2288                                         cqr->status = DASD_CQR_FAILED;
2289                                         maincqr->intrc = rc;
2290                                         continue;
2291                                 }
2292                         } else
2293                                 wait_event(generic_waitq, !(device->stopped));
2294                 }
2295                 if (!cqr->callback)
2296                         cqr->callback = dasd_wakeup_cb;
2297
2298                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2299                 dasd_add_request_tail(cqr);
2300                 if (interruptible) {
2301                         rc = wait_event_interruptible(
2302                                 generic_waitq, _wait_for_wakeup(cqr));
2303                         if (rc == -ERESTARTSYS) {
2304                                 dasd_cancel_req(cqr);
2305                                 /* wait (non-interruptible) for final status */
2306                                 wait_event(generic_waitq,
2307                                            _wait_for_wakeup(cqr));
2308                                 cqr->status = DASD_CQR_FAILED;
2309                                 maincqr->intrc = rc;
2310                                 continue;
2311                         }
2312                 } else
2313                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2314         }
2315
2316         maincqr->endclk = get_tod_clock();
2317         if ((maincqr->status != DASD_CQR_DONE) &&
2318             (maincqr->intrc != -ERESTARTSYS))
2319                 dasd_log_sense(maincqr, &maincqr->irb);
2320         if (maincqr->status == DASD_CQR_DONE)
2321                 rc = 0;
2322         else if (maincqr->intrc)
2323                 rc = maincqr->intrc;
2324         else
2325                 rc = -EIO;
2326         return rc;
2327 }
2328
2329 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2330 {
2331         struct dasd_ccw_req *cqr;
2332
2333         list_for_each_entry(cqr, ccw_queue, blocklist) {
2334                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2335                         return 0;
2336         }
2337
2338         return 1;
2339 }
2340
2341 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2342 {
2343         struct dasd_device *device;
2344         struct dasd_ccw_req *cqr, *n;
2345         u8 *sense = NULL;
2346         int rc;
2347
2348 retry:
2349         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2350                 device = cqr->startdev;
2351                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2352                         continue;
2353
2354                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2355                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2356                         cqr->status = DASD_CQR_FAILED;
2357                         cqr->intrc = -EPERM;
2358                         continue;
2359                 }
2360                 /*Non-temporary stop condition will trigger fail fast*/
2361                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2362                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2363                     !dasd_eer_enabled(device)) {
2364                         cqr->status = DASD_CQR_FAILED;
2365                         cqr->intrc = -EAGAIN;
2366                         continue;
2367                 }
2368
2369                 /*Don't try to start requests if device is stopped*/
2370                 if (interruptible) {
2371                         rc = wait_event_interruptible(
2372                                 generic_waitq, !device->stopped);
2373                         if (rc == -ERESTARTSYS) {
2374                                 cqr->status = DASD_CQR_FAILED;
2375                                 cqr->intrc = rc;
2376                                 continue;
2377                         }
2378                 } else
2379                         wait_event(generic_waitq, !(device->stopped));
2380
2381                 if (!cqr->callback)
2382                         cqr->callback = dasd_wakeup_cb;
2383                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2384                 dasd_add_request_tail(cqr);
2385         }
2386
2387         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2388
2389         rc = 0;
2390         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2391                 /*
2392                  * In some cases the 'File Protected' or 'Incorrect Length'
2393                  * error might be expected and error recovery would be
2394                  * unnecessary in these cases.  Check if the according suppress
2395                  * bit is set.
2396                  */
2397                 sense = dasd_get_sense(&cqr->irb);
2398                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2399                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2400                         continue;
2401                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2402                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2403                         continue;
2404
2405                 /*
2406                  * for alias devices simplify error recovery and
2407                  * return to upper layer
2408                  * do not skip ERP requests
2409                  */
2410                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2411                     (cqr->status == DASD_CQR_TERMINATED ||
2412                      cqr->status == DASD_CQR_NEED_ERP))
2413                         return -EAGAIN;
2414
2415                 /* normal recovery for basedev IO */
2416                 if (__dasd_sleep_on_erp(cqr))
2417                         /* handle erp first */
2418                         goto retry;
2419         }
2420
2421         return 0;
2422 }
2423
2424 /*
2425  * Queue a request to the tail of the device ccw_queue and wait for
2426  * it's completion.
2427  */
2428 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2429 {
2430         return _dasd_sleep_on(cqr, 0);
2431 }
2432 EXPORT_SYMBOL(dasd_sleep_on);
2433
2434 /*
2435  * Start requests from a ccw_queue and wait for their completion.
2436  */
2437 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2438 {
2439         return _dasd_sleep_on_queue(ccw_queue, 0);
2440 }
2441 EXPORT_SYMBOL(dasd_sleep_on_queue);
2442
2443 /*
2444  * Queue a request to the tail of the device ccw_queue and wait
2445  * interruptible for it's completion.
2446  */
2447 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2448 {
2449         return _dasd_sleep_on(cqr, 1);
2450 }
2451 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2452
2453 /*
2454  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2455  * for eckd devices) the currently running request has to be terminated
2456  * and be put back to status queued, before the special request is added
2457  * to the head of the queue. Then the special request is waited on normally.
2458  */
2459 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2460 {
2461         struct dasd_ccw_req *cqr;
2462         int rc;
2463
2464         if (list_empty(&device->ccw_queue))
2465                 return 0;
2466         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2467         rc = device->discipline->term_IO(cqr);
2468         if (!rc)
2469                 /*
2470                  * CQR terminated because a more important request is pending.
2471                  * Undo decreasing of retry counter because this is
2472                  * not an error case.
2473                  */
2474                 cqr->retries++;
2475         return rc;
2476 }
2477
2478 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2479 {
2480         struct dasd_device *device;
2481         int rc;
2482
2483         device = cqr->startdev;
2484         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2485             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2486                 cqr->status = DASD_CQR_FAILED;
2487                 cqr->intrc = -EPERM;
2488                 return -EIO;
2489         }
2490         spin_lock_irq(get_ccwdev_lock(device->cdev));
2491         rc = _dasd_term_running_cqr(device);
2492         if (rc) {
2493                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2494                 return rc;
2495         }
2496         cqr->callback = dasd_wakeup_cb;
2497         cqr->callback_data = DASD_SLEEPON_START_TAG;
2498         cqr->status = DASD_CQR_QUEUED;
2499         /*
2500          * add new request as second
2501          * first the terminated cqr needs to be finished
2502          */
2503         list_add(&cqr->devlist, device->ccw_queue.next);
2504
2505         /* let the bh start the request to keep them in order */
2506         dasd_schedule_device_bh(device);
2507
2508         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2509
2510         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2511
2512         if (cqr->status == DASD_CQR_DONE)
2513                 rc = 0;
2514         else if (cqr->intrc)
2515                 rc = cqr->intrc;
2516         else
2517                 rc = -EIO;
2518
2519         /* kick tasklets */
2520         dasd_schedule_device_bh(device);
2521         if (device->block)
2522                 dasd_schedule_block_bh(device->block);
2523
2524         return rc;
2525 }
2526 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2527
2528 /*
2529  * Cancels a request that was started with dasd_sleep_on_req.
2530  * This is useful to timeout requests. The request will be
2531  * terminated if it is currently in i/o.
2532  * Returns 0 if request termination was successful
2533  *         negative error code if termination failed
2534  * Cancellation of a request is an asynchronous operation! The calling
2535  * function has to wait until the request is properly returned via callback.
2536  */
2537 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2538 {
2539         struct dasd_device *device = cqr->startdev;
2540         unsigned long flags;
2541         int rc;
2542
2543         rc = 0;
2544         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2545         switch (cqr->status) {
2546         case DASD_CQR_QUEUED:
2547                 /* request was not started - just set to cleared */
2548                 cqr->status = DASD_CQR_CLEARED;
2549                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2550                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2551                 break;
2552         case DASD_CQR_IN_IO:
2553                 /* request in IO - terminate IO and release again */
2554                 rc = device->discipline->term_IO(cqr);
2555                 if (rc) {
2556                         dev_err(&device->cdev->dev,
2557                                 "Cancelling request %p failed with rc=%d\n",
2558                                 cqr, rc);
2559                 } else {
2560                         cqr->stopclk = get_tod_clock();
2561                 }
2562                 break;
2563         default: /* already finished or clear pending - do nothing */
2564                 break;
2565         }
2566         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2567         dasd_schedule_device_bh(device);
2568         return rc;
2569 }
2570 EXPORT_SYMBOL(dasd_cancel_req);
2571
2572 /*
2573  * SECTION: Operations of the dasd_block layer.
2574  */
2575
2576 /*
2577  * Timeout function for dasd_block. This is used when the block layer
2578  * is waiting for something that may not come reliably, (e.g. a state
2579  * change interrupt)
2580  */
2581 static void dasd_block_timeout(unsigned long ptr)
2582 {
2583         unsigned long flags;
2584         struct dasd_block *block;
2585
2586         block = (struct dasd_block *) ptr;
2587         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2588         /* re-activate request queue */
2589         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2590         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2591         dasd_schedule_block_bh(block);
2592 }
2593
2594 /*
2595  * Setup timeout for a dasd_block in jiffies.
2596  */
2597 void dasd_block_set_timer(struct dasd_block *block, int expires)
2598 {
2599         if (expires == 0)
2600                 del_timer(&block->timer);
2601         else
2602                 mod_timer(&block->timer, jiffies + expires);
2603 }
2604 EXPORT_SYMBOL(dasd_block_set_timer);
2605
2606 /*
2607  * Clear timeout for a dasd_block.
2608  */
2609 void dasd_block_clear_timer(struct dasd_block *block)
2610 {
2611         del_timer(&block->timer);
2612 }
2613 EXPORT_SYMBOL(dasd_block_clear_timer);
2614
2615 /*
2616  * Process finished error recovery ccw.
2617  */
2618 static void __dasd_process_erp(struct dasd_device *device,
2619                                struct dasd_ccw_req *cqr)
2620 {
2621         dasd_erp_fn_t erp_fn;
2622
2623         if (cqr->status == DASD_CQR_DONE)
2624                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2625         else
2626                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2627         erp_fn = device->discipline->erp_postaction(cqr);
2628         erp_fn(cqr);
2629 }
2630
2631 /*
2632  * Fetch requests from the block device queue.
2633  */
2634 static void __dasd_process_request_queue(struct dasd_block *block)
2635 {
2636         struct request_queue *queue;
2637         struct request *req;
2638         struct dasd_ccw_req *cqr;
2639         struct dasd_device *basedev;
2640         unsigned long flags;
2641         queue = block->request_queue;
2642         basedev = block->base;
2643         /* No queue ? Then there is nothing to do. */
2644         if (queue == NULL)
2645                 return;
2646
2647         /*
2648          * We requeue request from the block device queue to the ccw
2649          * queue only in two states. In state DASD_STATE_READY the
2650          * partition detection is done and we need to requeue requests
2651          * for that. State DASD_STATE_ONLINE is normal block device
2652          * operation.
2653          */
2654         if (basedev->state < DASD_STATE_READY) {
2655                 while ((req = blk_fetch_request(block->request_queue)))
2656                         __blk_end_request_all(req, -EIO);
2657                 return;
2658         }
2659
2660         /*
2661          * if device is stopped do not fetch new requests
2662          * except failfast is active which will let requests fail
2663          * immediately in __dasd_block_start_head()
2664          */
2665         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST))
2666                 return;
2667
2668         /* Now we try to fetch requests from the request queue */
2669         while ((req = blk_peek_request(queue))) {
2670                 if (basedev->features & DASD_FEATURE_READONLY &&
2671                     rq_data_dir(req) == WRITE) {
2672                         DBF_DEV_EVENT(DBF_ERR, basedev,
2673                                       "Rejecting write request %p",
2674                                       req);
2675                         blk_start_request(req);
2676                         __blk_end_request_all(req, -EIO);
2677                         continue;
2678                 }
2679                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2680                     (basedev->features & DASD_FEATURE_FAILFAST ||
2681                      blk_noretry_request(req))) {
2682                         DBF_DEV_EVENT(DBF_ERR, basedev,
2683                                       "Rejecting failfast request %p",
2684                                       req);
2685                         blk_start_request(req);
2686                         __blk_end_request_all(req, -ETIMEDOUT);
2687                         continue;
2688                 }
2689                 cqr = basedev->discipline->build_cp(basedev, block, req);
2690                 if (IS_ERR(cqr)) {
2691                         if (PTR_ERR(cqr) == -EBUSY)
2692                                 break;  /* normal end condition */
2693                         if (PTR_ERR(cqr) == -ENOMEM)
2694                                 break;  /* terminate request queue loop */
2695                         if (PTR_ERR(cqr) == -EAGAIN) {
2696                                 /*
2697                                  * The current request cannot be build right
2698                                  * now, we have to try later. If this request
2699                                  * is the head-of-queue we stop the device
2700                                  * for 1/2 second.
2701                                  */
2702                                 if (!list_empty(&block->ccw_queue))
2703                                         break;
2704                                 spin_lock_irqsave(
2705                                         get_ccwdev_lock(basedev->cdev), flags);
2706                                 dasd_device_set_stop_bits(basedev,
2707                                                           DASD_STOPPED_PENDING);
2708                                 spin_unlock_irqrestore(
2709                                         get_ccwdev_lock(basedev->cdev), flags);
2710                                 dasd_block_set_timer(block, HZ/2);
2711                                 break;
2712                         }
2713                         DBF_DEV_EVENT(DBF_ERR, basedev,
2714                                       "CCW creation failed (rc=%ld) "
2715                                       "on request %p",
2716                                       PTR_ERR(cqr), req);
2717                         blk_start_request(req);
2718                         __blk_end_request_all(req, -EIO);
2719                         continue;
2720                 }
2721                 /*
2722                  *  Note: callback is set to dasd_return_cqr_cb in
2723                  * __dasd_block_start_head to cover erp requests as well
2724                  */
2725                 cqr->callback_data = (void *) req;
2726                 cqr->status = DASD_CQR_FILLED;
2727                 req->completion_data = cqr;
2728                 blk_start_request(req);
2729                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2730                 INIT_LIST_HEAD(&cqr->devlist);
2731                 dasd_profile_start(block, cqr, req);
2732         }
2733 }
2734
2735 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2736 {
2737         struct request *req;
2738         int status;
2739         int error = 0;
2740
2741         req = (struct request *) cqr->callback_data;
2742         dasd_profile_end(cqr->block, cqr, req);
2743         status = cqr->block->base->discipline->free_cp(cqr, req);
2744         if (status < 0)
2745                 error = status;
2746         else if (status == 0) {
2747                 if (cqr->intrc == -EPERM)
2748                         error = -EBADE;
2749                 else if (cqr->intrc == -ENOLINK ||
2750                          cqr->intrc == -ETIMEDOUT)
2751                         error = cqr->intrc;
2752                 else
2753                         error = -EIO;
2754         }
2755         __blk_end_request_all(req, error);
2756 }
2757
2758 /*
2759  * Process ccw request queue.
2760  */
2761 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2762                                            struct list_head *final_queue)
2763 {
2764         struct list_head *l, *n;
2765         struct dasd_ccw_req *cqr;
2766         dasd_erp_fn_t erp_fn;
2767         unsigned long flags;
2768         struct dasd_device *base = block->base;
2769
2770 restart:
2771         /* Process request with final status. */
2772         list_for_each_safe(l, n, &block->ccw_queue) {
2773                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2774                 if (cqr->status != DASD_CQR_DONE &&
2775                     cqr->status != DASD_CQR_FAILED &&
2776                     cqr->status != DASD_CQR_NEED_ERP &&
2777                     cqr->status != DASD_CQR_TERMINATED)
2778                         continue;
2779
2780                 if (cqr->status == DASD_CQR_TERMINATED) {
2781                         base->discipline->handle_terminated_request(cqr);
2782                         goto restart;
2783                 }
2784
2785                 /*  Process requests that may be recovered */
2786                 if (cqr->status == DASD_CQR_NEED_ERP) {
2787                         erp_fn = base->discipline->erp_action(cqr);
2788                         if (IS_ERR(erp_fn(cqr)))
2789                                 continue;
2790                         goto restart;
2791                 }
2792
2793                 /* log sense for fatal error */
2794                 if (cqr->status == DASD_CQR_FAILED) {
2795                         dasd_log_sense(cqr, &cqr->irb);
2796                 }
2797
2798                 /* First of all call extended error reporting. */
2799                 if (dasd_eer_enabled(base) &&
2800                     cqr->status == DASD_CQR_FAILED) {
2801                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2802
2803                         /* restart request  */
2804                         cqr->status = DASD_CQR_FILLED;
2805                         cqr->retries = 255;
2806                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2807                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2808                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2809                                                flags);
2810                         goto restart;
2811                 }
2812
2813                 /* Process finished ERP request. */
2814                 if (cqr->refers) {
2815                         __dasd_process_erp(base, cqr);
2816                         goto restart;
2817                 }
2818
2819                 /* Rechain finished requests to final queue */
2820                 cqr->endclk = get_tod_clock();
2821                 list_move_tail(&cqr->blocklist, final_queue);
2822         }
2823 }
2824
2825 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2826 {
2827         dasd_schedule_block_bh(cqr->block);
2828 }
2829
2830 static void __dasd_block_start_head(struct dasd_block *block)
2831 {
2832         struct dasd_ccw_req *cqr;
2833
2834         if (list_empty(&block->ccw_queue))
2835                 return;
2836         /* We allways begin with the first requests on the queue, as some
2837          * of previously started requests have to be enqueued on a
2838          * dasd_device again for error recovery.
2839          */
2840         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2841                 if (cqr->status != DASD_CQR_FILLED)
2842                         continue;
2843                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2844                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2845                         cqr->status = DASD_CQR_FAILED;
2846                         cqr->intrc = -EPERM;
2847                         dasd_schedule_block_bh(block);
2848                         continue;
2849                 }
2850                 /* Non-temporary stop condition will trigger fail fast */
2851                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2852                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2853                     (!dasd_eer_enabled(block->base))) {
2854                         cqr->status = DASD_CQR_FAILED;
2855                         cqr->intrc = -ENOLINK;
2856                         dasd_schedule_block_bh(block);
2857                         continue;
2858                 }
2859                 /* Don't try to start requests if device is stopped */
2860                 if (block->base->stopped)
2861                         return;
2862
2863                 /* just a fail safe check, should not happen */
2864                 if (!cqr->startdev)
2865                         cqr->startdev = block->base;
2866
2867                 /* make sure that the requests we submit find their way back */
2868                 cqr->callback = dasd_return_cqr_cb;
2869
2870                 dasd_add_request_tail(cqr);
2871         }
2872 }
2873
2874 /*
2875  * Central dasd_block layer routine. Takes requests from the generic
2876  * block layer request queue, creates ccw requests, enqueues them on
2877  * a dasd_device and processes ccw requests that have been returned.
2878  */
2879 static void dasd_block_tasklet(struct dasd_block *block)
2880 {
2881         struct list_head final_queue;
2882         struct list_head *l, *n;
2883         struct dasd_ccw_req *cqr;
2884
2885         atomic_set(&block->tasklet_scheduled, 0);
2886         INIT_LIST_HEAD(&final_queue);
2887         spin_lock(&block->queue_lock);
2888         /* Finish off requests on ccw queue */
2889         __dasd_process_block_ccw_queue(block, &final_queue);
2890         spin_unlock(&block->queue_lock);
2891         /* Now call the callback function of requests with final status */
2892         spin_lock_irq(&block->request_queue_lock);
2893         list_for_each_safe(l, n, &final_queue) {
2894                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2895                 list_del_init(&cqr->blocklist);
2896                 __dasd_cleanup_cqr(cqr);
2897         }
2898         spin_lock(&block->queue_lock);
2899         /* Get new request from the block device request queue */
2900         __dasd_process_request_queue(block);
2901         /* Now check if the head of the ccw queue needs to be started. */
2902         __dasd_block_start_head(block);
2903         spin_unlock(&block->queue_lock);
2904         spin_unlock_irq(&block->request_queue_lock);
2905         if (waitqueue_active(&shutdown_waitq))
2906                 wake_up(&shutdown_waitq);
2907         dasd_put_device(block->base);
2908 }
2909
2910 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2911 {
2912         wake_up(&dasd_flush_wq);
2913 }
2914
2915 /*
2916  * Requeue a request back to the block request queue
2917  * only works for block requests
2918  */
2919 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2920 {
2921         struct dasd_block *block = cqr->block;
2922         struct request *req;
2923         unsigned long flags;
2924
2925         if (!block)
2926                 return -EINVAL;
2927         spin_lock_irqsave(&block->queue_lock, flags);
2928         req = (struct request *) cqr->callback_data;
2929         blk_requeue_request(block->request_queue, req);
2930         spin_unlock_irqrestore(&block->queue_lock, flags);
2931
2932         return 0;
2933 }
2934
2935 /*
2936  * Go through all request on the dasd_block request queue, cancel them
2937  * on the respective dasd_device, and return them to the generic
2938  * block layer.
2939  */
2940 static int dasd_flush_block_queue(struct dasd_block *block)
2941 {
2942         struct dasd_ccw_req *cqr, *n;
2943         int rc, i;
2944         struct list_head flush_queue;
2945
2946         INIT_LIST_HEAD(&flush_queue);
2947         spin_lock_bh(&block->queue_lock);
2948         rc = 0;
2949 restart:
2950         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2951                 /* if this request currently owned by a dasd_device cancel it */
2952                 if (cqr->status >= DASD_CQR_QUEUED)
2953                         rc = dasd_cancel_req(cqr);
2954                 if (rc < 0)
2955                         break;
2956                 /* Rechain request (including erp chain) so it won't be
2957                  * touched by the dasd_block_tasklet anymore.
2958                  * Replace the callback so we notice when the request
2959                  * is returned from the dasd_device layer.
2960                  */
2961                 cqr->callback = _dasd_wake_block_flush_cb;
2962                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2963                         list_move_tail(&cqr->blocklist, &flush_queue);
2964                 if (i > 1)
2965                         /* moved more than one request - need to restart */
2966                         goto restart;
2967         }
2968         spin_unlock_bh(&block->queue_lock);
2969         /* Now call the callback function of flushed requests */
2970 restart_cb:
2971         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2972                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2973                 /* Process finished ERP request. */
2974                 if (cqr->refers) {
2975                         spin_lock_bh(&block->queue_lock);
2976                         __dasd_process_erp(block->base, cqr);
2977                         spin_unlock_bh(&block->queue_lock);
2978                         /* restart list_for_xx loop since dasd_process_erp
2979                          * might remove multiple elements */
2980                         goto restart_cb;
2981                 }
2982                 /* call the callback function */
2983                 spin_lock_irq(&block->request_queue_lock);
2984                 cqr->endclk = get_tod_clock();
2985                 list_del_init(&cqr->blocklist);
2986                 __dasd_cleanup_cqr(cqr);
2987                 spin_unlock_irq(&block->request_queue_lock);
2988         }
2989         return rc;
2990 }
2991
2992 /*
2993  * Schedules a call to dasd_tasklet over the device tasklet.
2994  */
2995 void dasd_schedule_block_bh(struct dasd_block *block)
2996 {
2997         /* Protect against rescheduling. */
2998         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2999                 return;
3000         /* life cycle of block is bound to it's base device */
3001         dasd_get_device(block->base);
3002         tasklet_hi_schedule(&block->tasklet);
3003 }
3004 EXPORT_SYMBOL(dasd_schedule_block_bh);
3005
3006
3007 /*
3008  * SECTION: external block device operations
3009  * (request queue handling, open, release, etc.)
3010  */
3011
3012 /*
3013  * Dasd request queue function. Called from ll_rw_blk.c
3014  */
3015 static void do_dasd_request(struct request_queue *queue)
3016 {
3017         struct dasd_block *block;
3018
3019         block = queue->queuedata;
3020         spin_lock(&block->queue_lock);
3021         /* Get new request from the block device request queue */
3022         __dasd_process_request_queue(block);
3023         /* Now check if the head of the ccw queue needs to be started. */
3024         __dasd_block_start_head(block);
3025         spin_unlock(&block->queue_lock);
3026 }
3027
3028 /*
3029  * Block timeout callback, called from the block layer
3030  *
3031  * request_queue lock is held on entry.
3032  *
3033  * Return values:
3034  * BLK_EH_RESET_TIMER if the request should be left running
3035  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3036  *                    by the driver.
3037  */
3038 enum blk_eh_timer_return dasd_times_out(struct request *req)
3039 {
3040         struct dasd_ccw_req *cqr = req->completion_data;
3041         struct dasd_block *block = req->q->queuedata;
3042         struct dasd_device *device;
3043         int rc = 0;
3044
3045         if (!cqr)
3046                 return BLK_EH_NOT_HANDLED;
3047
3048         device = cqr->startdev ? cqr->startdev : block->base;
3049         if (!device->blk_timeout)
3050                 return BLK_EH_RESET_TIMER;
3051         DBF_DEV_EVENT(DBF_WARNING, device,
3052                       " dasd_times_out cqr %p status %x",
3053                       cqr, cqr->status);
3054
3055         spin_lock(&block->queue_lock);
3056         spin_lock(get_ccwdev_lock(device->cdev));
3057         cqr->retries = -1;
3058         cqr->intrc = -ETIMEDOUT;
3059         if (cqr->status >= DASD_CQR_QUEUED) {
3060                 spin_unlock(get_ccwdev_lock(device->cdev));
3061                 rc = dasd_cancel_req(cqr);
3062         } else if (cqr->status == DASD_CQR_FILLED ||
3063                    cqr->status == DASD_CQR_NEED_ERP) {
3064                 cqr->status = DASD_CQR_TERMINATED;
3065                 spin_unlock(get_ccwdev_lock(device->cdev));
3066         } else if (cqr->status == DASD_CQR_IN_ERP) {
3067                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3068
3069                 list_for_each_entry_safe(searchcqr, nextcqr,
3070                                          &block->ccw_queue, blocklist) {
3071                         tmpcqr = searchcqr;
3072                         while (tmpcqr->refers)
3073                                 tmpcqr = tmpcqr->refers;
3074                         if (tmpcqr != cqr)
3075                                 continue;
3076                         /* searchcqr is an ERP request for cqr */
3077                         searchcqr->retries = -1;
3078                         searchcqr->intrc = -ETIMEDOUT;
3079                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3080                                 spin_unlock(get_ccwdev_lock(device->cdev));
3081                                 rc = dasd_cancel_req(searchcqr);
3082                                 spin_lock(get_ccwdev_lock(device->cdev));
3083                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3084                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3085                                 searchcqr->status = DASD_CQR_TERMINATED;
3086                                 rc = 0;
3087                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3088                                 /*
3089                                  * Shouldn't happen; most recent ERP
3090                                  * request is at the front of queue
3091                                  */
3092                                 continue;
3093                         }
3094                         break;
3095                 }
3096                 spin_unlock(get_ccwdev_lock(device->cdev));
3097         }
3098         dasd_schedule_block_bh(block);
3099         spin_unlock(&block->queue_lock);
3100
3101         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3102 }
3103
3104 /*
3105  * Allocate and initialize request queue and default I/O scheduler.
3106  */
3107 static int dasd_alloc_queue(struct dasd_block *block)
3108 {
3109         block->request_queue = blk_init_queue(do_dasd_request,
3110                                                &block->request_queue_lock);
3111         if (block->request_queue == NULL)
3112                 return -ENOMEM;
3113
3114         block->request_queue->queuedata = block;
3115
3116         return 0;
3117 }
3118
3119 /*
3120  * Allocate and initialize request queue.
3121  */
3122 static void dasd_setup_queue(struct dasd_block *block)
3123 {
3124         int max;
3125
3126         if (block->base->features & DASD_FEATURE_USERAW) {
3127                 /*
3128                  * the max_blocks value for raw_track access is 256
3129                  * it is higher than the native ECKD value because we
3130                  * only need one ccw per track
3131                  * so the max_hw_sectors are
3132                  * 2048 x 512B = 1024kB = 16 tracks
3133                  */
3134                 max = 2048;
3135         } else {
3136                 max = block->base->discipline->max_blocks << block->s2b_shift;
3137         }
3138         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue);
3139         block->request_queue->limits.max_dev_sectors = max;
3140         blk_queue_logical_block_size(block->request_queue,
3141                                      block->bp_block);
3142         blk_queue_max_hw_sectors(block->request_queue, max);
3143         blk_queue_max_segments(block->request_queue, -1L);
3144         /* with page sized segments we can translate each segement into
3145          * one idaw/tidaw
3146          */
3147         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3148         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3149 }
3150
3151 /*
3152  * Deactivate and free request queue.
3153  */
3154 static void dasd_free_queue(struct dasd_block *block)
3155 {
3156         if (block->request_queue) {
3157                 blk_cleanup_queue(block->request_queue);
3158                 block->request_queue = NULL;
3159         }
3160 }
3161
3162 /*
3163  * Flush request on the request queue.
3164  */
3165 static void dasd_flush_request_queue(struct dasd_block *block)
3166 {
3167         struct request *req;
3168
3169         if (!block->request_queue)
3170                 return;
3171
3172         spin_lock_irq(&block->request_queue_lock);
3173         while ((req = blk_fetch_request(block->request_queue)))
3174                 __blk_end_request_all(req, -EIO);
3175         spin_unlock_irq(&block->request_queue_lock);
3176 }
3177
3178 static int dasd_open(struct block_device *bdev, fmode_t mode)
3179 {
3180         struct dasd_device *base;
3181         int rc;
3182
3183         base = dasd_device_from_gendisk(bdev->bd_disk);
3184         if (!base)
3185                 return -ENODEV;
3186
3187         atomic_inc(&base->block->open_count);
3188         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3189                 rc = -ENODEV;
3190                 goto unlock;
3191         }
3192
3193         if (!try_module_get(base->discipline->owner)) {
3194                 rc = -EINVAL;
3195                 goto unlock;
3196         }
3197
3198         if (dasd_probeonly) {
3199                 dev_info(&base->cdev->dev,
3200                          "Accessing the DASD failed because it is in "
3201                          "probeonly mode\n");
3202                 rc = -EPERM;
3203                 goto out;
3204         }
3205
3206         if (base->state <= DASD_STATE_BASIC) {
3207                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3208                               " Cannot open unrecognized device");
3209                 rc = -ENODEV;
3210                 goto out;
3211         }
3212
3213         if ((mode & FMODE_WRITE) &&
3214             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3215              (base->features & DASD_FEATURE_READONLY))) {
3216                 rc = -EROFS;
3217                 goto out;
3218         }
3219
3220         dasd_put_device(base);
3221         return 0;
3222
3223 out:
3224         module_put(base->discipline->owner);
3225 unlock:
3226         atomic_dec(&base->block->open_count);
3227         dasd_put_device(base);
3228         return rc;
3229 }
3230
3231 static void dasd_release(struct gendisk *disk, fmode_t mode)
3232 {
3233         struct dasd_device *base = dasd_device_from_gendisk(disk);
3234         if (base) {
3235                 atomic_dec(&base->block->open_count);
3236                 module_put(base->discipline->owner);
3237                 dasd_put_device(base);
3238         }
3239 }
3240
3241 /*
3242  * Return disk geometry.
3243  */
3244 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3245 {
3246         struct dasd_device *base;
3247
3248         base = dasd_device_from_gendisk(bdev->bd_disk);
3249         if (!base)
3250                 return -ENODEV;
3251
3252         if (!base->discipline ||
3253             !base->discipline->fill_geometry) {
3254                 dasd_put_device(base);
3255                 return -EINVAL;
3256         }
3257         base->discipline->fill_geometry(base->block, geo);
3258         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3259         dasd_put_device(base);
3260         return 0;
3261 }
3262
3263 const struct block_device_operations
3264 dasd_device_operations = {
3265         .owner          = THIS_MODULE,
3266         .open           = dasd_open,
3267         .release        = dasd_release,
3268         .ioctl          = dasd_ioctl,
3269         .compat_ioctl   = dasd_ioctl,
3270         .getgeo         = dasd_getgeo,
3271 };
3272
3273 /*******************************************************************************
3274  * end of block device operations
3275  */
3276
3277 static void
3278 dasd_exit(void)
3279 {
3280 #ifdef CONFIG_PROC_FS
3281         dasd_proc_exit();
3282 #endif
3283         dasd_eer_exit();
3284         if (dasd_page_cache != NULL) {
3285                 kmem_cache_destroy(dasd_page_cache);
3286                 dasd_page_cache = NULL;
3287         }
3288         dasd_gendisk_exit();
3289         dasd_devmap_exit();
3290         if (dasd_debug_area != NULL) {
3291                 debug_unregister(dasd_debug_area);
3292                 dasd_debug_area = NULL;
3293         }
3294         dasd_statistics_removeroot();
3295 }
3296
3297 /*
3298  * SECTION: common functions for ccw_driver use
3299  */
3300
3301 /*
3302  * Is the device read-only?
3303  * Note that this function does not report the setting of the
3304  * readonly device attribute, but how it is configured in z/VM.
3305  */
3306 int dasd_device_is_ro(struct dasd_device *device)
3307 {
3308         struct ccw_dev_id dev_id;
3309         struct diag210 diag_data;
3310         int rc;
3311
3312         if (!MACHINE_IS_VM)
3313                 return 0;
3314         ccw_device_get_id(device->cdev, &dev_id);
3315         memset(&diag_data, 0, sizeof(diag_data));
3316         diag_data.vrdcdvno = dev_id.devno;
3317         diag_data.vrdclen = sizeof(diag_data);
3318         rc = diag210(&diag_data);
3319         if (rc == 0 || rc == 2) {
3320                 return diag_data.vrdcvfla & 0x80;
3321         } else {
3322                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3323                           dev_id.devno, rc);
3324                 return 0;
3325         }
3326 }
3327 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3328
3329 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3330 {
3331         struct ccw_device *cdev = data;
3332         int ret;
3333
3334         ret = ccw_device_set_online(cdev);
3335         if (ret)
3336                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3337                         dev_name(&cdev->dev), ret);
3338 }
3339
3340 /*
3341  * Initial attempt at a probe function. this can be simplified once
3342  * the other detection code is gone.
3343  */
3344 int dasd_generic_probe(struct ccw_device *cdev,
3345                        struct dasd_discipline *discipline)
3346 {
3347         int ret;
3348
3349         ret = dasd_add_sysfs_files(cdev);
3350         if (ret) {
3351                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3352                                 "dasd_generic_probe: could not add "
3353                                 "sysfs entries");
3354                 return ret;
3355         }
3356         cdev->handler = &dasd_int_handler;
3357
3358         /*
3359          * Automatically online either all dasd devices (dasd_autodetect)
3360          * or all devices specified with dasd= parameters during
3361          * initial probe.
3362          */
3363         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3364             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3365                 async_schedule(dasd_generic_auto_online, cdev);
3366         return 0;
3367 }
3368 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3369
3370 void dasd_generic_free_discipline(struct dasd_device *device)
3371 {
3372         /* Forget the discipline information. */
3373         if (device->discipline) {
3374                 if (device->discipline->uncheck_device)
3375                         device->discipline->uncheck_device(device);
3376                 module_put(device->discipline->owner);
3377                 device->discipline = NULL;
3378         }
3379         if (device->base_discipline) {
3380                 module_put(device->base_discipline->owner);
3381                 device->base_discipline = NULL;
3382         }
3383 }
3384 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3385
3386 /*
3387  * This will one day be called from a global not_oper handler.
3388  * It is also used by driver_unregister during module unload.
3389  */
3390 void dasd_generic_remove(struct ccw_device *cdev)
3391 {
3392         struct dasd_device *device;
3393         struct dasd_block *block;
3394
3395         cdev->handler = NULL;
3396
3397         device = dasd_device_from_cdev(cdev);
3398         if (IS_ERR(device)) {
3399                 dasd_remove_sysfs_files(cdev);
3400                 return;
3401         }
3402         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3403             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3404                 /* Already doing offline processing */
3405                 dasd_put_device(device);
3406                 dasd_remove_sysfs_files(cdev);
3407                 return;
3408         }
3409         /*
3410          * This device is removed unconditionally. Set offline
3411          * flag to prevent dasd_open from opening it while it is
3412          * no quite down yet.
3413          */
3414         dasd_set_target_state(device, DASD_STATE_NEW);
3415         /* dasd_delete_device destroys the device reference. */
3416         block = device->block;
3417         dasd_delete_device(device);
3418         /*
3419          * life cycle of block is bound to device, so delete it after
3420          * device was safely removed
3421          */
3422         if (block)
3423                 dasd_free_block(block);
3424
3425         dasd_remove_sysfs_files(cdev);
3426 }
3427 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3428
3429 /*
3430  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3431  * the device is detected for the first time and is supposed to be used
3432  * or the user has started activation through sysfs.
3433  */
3434 int dasd_generic_set_online(struct ccw_device *cdev,
3435                             struct dasd_discipline *base_discipline)
3436 {
3437         struct dasd_discipline *discipline;
3438         struct dasd_device *device;
3439         int rc;
3440
3441         /* first online clears initial online feature flag */
3442         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3443         device = dasd_create_device(cdev);
3444         if (IS_ERR(device))
3445                 return PTR_ERR(device);
3446
3447         discipline = base_discipline;
3448         if (device->features & DASD_FEATURE_USEDIAG) {
3449                 if (!dasd_diag_discipline_pointer) {
3450                         /* Try to load the required module. */
3451                         rc = request_module(DASD_DIAG_MOD);
3452                         if (rc) {
3453                                 pr_warn("%s Setting the DASD online failed "
3454                                         "because the required module %s "
3455                                         "could not be loaded (rc=%d)\n",
3456                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3457                                         rc);
3458                                 dasd_delete_device(device);
3459                                 return -ENODEV;
3460                         }
3461                 }
3462                 /* Module init could have failed, so check again here after
3463                  * request_module(). */
3464                 if (!dasd_diag_discipline_pointer) {
3465                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3466                                 dev_name(&cdev->dev));
3467                         dasd_delete_device(device);
3468                         return -ENODEV;
3469                 }
3470                 discipline = dasd_diag_discipline_pointer;
3471         }
3472         if (!try_module_get(base_discipline->owner)) {
3473                 dasd_delete_device(device);
3474                 return -EINVAL;
3475         }
3476         if (!try_module_get(discipline->owner)) {
3477                 module_put(base_discipline->owner);
3478                 dasd_delete_device(device);
3479                 return -EINVAL;
3480         }
3481         device->base_discipline = base_discipline;
3482         device->discipline = discipline;
3483
3484         /* check_device will allocate block device if necessary */
3485         rc = discipline->check_device(device);
3486         if (rc) {
3487                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3488                         dev_name(&cdev->dev), discipline->name, rc);
3489                 module_put(discipline->owner);
3490                 module_put(base_discipline->owner);
3491                 dasd_delete_device(device);
3492                 return rc;
3493         }
3494
3495         dasd_set_target_state(device, DASD_STATE_ONLINE);
3496         if (device->state <= DASD_STATE_KNOWN) {
3497                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3498                         dev_name(&cdev->dev));
3499                 rc = -ENODEV;
3500                 dasd_set_target_state(device, DASD_STATE_NEW);
3501                 if (device->block)
3502                         dasd_free_block(device->block);
3503                 dasd_delete_device(device);
3504         } else
3505                 pr_debug("dasd_generic device %s found\n",
3506                                 dev_name(&cdev->dev));
3507
3508         wait_event(dasd_init_waitq, _wait_for_device(device));
3509
3510         dasd_put_device(device);
3511         return rc;
3512 }
3513 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3514
3515 int dasd_generic_set_offline(struct ccw_device *cdev)
3516 {
3517         struct dasd_device *device;
3518         struct dasd_block *block;
3519         int max_count, open_count, rc;
3520
3521         rc = 0;
3522         device = dasd_device_from_cdev(cdev);
3523         if (IS_ERR(device))
3524                 return PTR_ERR(device);
3525
3526         /*
3527          * We must make sure that this device is currently not in use.
3528          * The open_count is increased for every opener, that includes
3529          * the blkdev_get in dasd_scan_partitions. We are only interested
3530          * in the other openers.
3531          */
3532         if (device->block) {
3533                 max_count = device->block->bdev ? 0 : -1;
3534                 open_count = atomic_read(&device->block->open_count);
3535                 if (open_count > max_count) {
3536                         if (open_count > 0)
3537                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3538                                         dev_name(&cdev->dev), open_count);
3539                         else
3540                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3541                                         dev_name(&cdev->dev));
3542                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3543                         dasd_put_device(device);
3544                         return -EBUSY;
3545                 }
3546         }
3547
3548         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3549                 /*
3550                  * safe offline already running
3551                  * could only be called by normal offline so safe_offline flag
3552                  * needs to be removed to run normal offline and kill all I/O
3553                  */
3554                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3555                         /* Already doing normal offline processing */
3556                         dasd_put_device(device);
3557                         return -EBUSY;
3558                 } else
3559                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3560
3561         } else
3562                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3563                         /* Already doing offline processing */
3564                         dasd_put_device(device);
3565                         return -EBUSY;
3566                 }
3567
3568         /*
3569          * if safe_offline called set safe_offline_running flag and
3570          * clear safe_offline so that a call to normal offline
3571          * can overrun safe_offline processing
3572          */
3573         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3574             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3575                 /*
3576                  * If we want to set the device safe offline all IO operations
3577                  * should be finished before continuing the offline process
3578                  * so sync bdev first and then wait for our queues to become
3579                  * empty
3580                  */
3581                 /* sync blockdev and partitions */
3582                 rc = fsync_bdev(device->block->bdev);
3583                 if (rc != 0)
3584                         goto interrupted;
3585
3586                 /* schedule device tasklet and wait for completion */
3587                 dasd_schedule_device_bh(device);
3588                 rc = wait_event_interruptible(shutdown_waitq,
3589                                               _wait_for_empty_queues(device));
3590                 if (rc != 0)
3591                         goto interrupted;
3592         }
3593
3594         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3595         dasd_set_target_state(device, DASD_STATE_NEW);
3596         /* dasd_delete_device destroys the device reference. */
3597         block = device->block;
3598         dasd_delete_device(device);
3599         /*
3600          * life cycle of block is bound to device, so delete it after
3601          * device was safely removed
3602          */
3603         if (block)
3604                 dasd_free_block(block);
3605         return 0;
3606
3607 interrupted:
3608         /* interrupted by signal */
3609         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3610         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3611         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3612         dasd_put_device(device);
3613         return rc;
3614 }
3615 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3616
3617 int dasd_generic_last_path_gone(struct dasd_device *device)
3618 {
3619         struct dasd_ccw_req *cqr;
3620
3621         dev_warn(&device->cdev->dev, "No operational channel path is left "
3622                  "for the device\n");
3623         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3624         /* First of all call extended error reporting. */
3625         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3626
3627         if (device->state < DASD_STATE_BASIC)
3628                 return 0;
3629         /* Device is active. We want to keep it. */
3630         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3631                 if ((cqr->status == DASD_CQR_IN_IO) ||
3632                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3633                         cqr->status = DASD_CQR_QUEUED;
3634                         cqr->retries++;
3635                 }
3636         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3637         dasd_device_clear_timer(device);
3638         dasd_schedule_device_bh(device);
3639         return 1;
3640 }
3641 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3642
3643 int dasd_generic_path_operational(struct dasd_device *device)
3644 {
3645         dev_info(&device->cdev->dev, "A channel path to the device has become "
3646                  "operational\n");
3647         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3648         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3649         if (device->stopped & DASD_UNRESUMED_PM) {
3650                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3651                 dasd_restore_device(device);
3652                 return 1;
3653         }
3654         dasd_schedule_device_bh(device);
3655         if (device->block)
3656                 dasd_schedule_block_bh(device->block);
3657
3658         if (!device->stopped)
3659                 wake_up(&generic_waitq);
3660
3661         return 1;
3662 }
3663 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3664
3665 int dasd_generic_notify(struct ccw_device *cdev, int event)
3666 {
3667         struct dasd_device *device;
3668         int ret;
3669
3670         device = dasd_device_from_cdev_locked(cdev);
3671         if (IS_ERR(device))
3672                 return 0;
3673         ret = 0;
3674         switch (event) {
3675         case CIO_GONE:
3676         case CIO_BOXED:
3677         case CIO_NO_PATH:
3678                 device->path_data.opm = 0;
3679                 device->path_data.ppm = 0;
3680                 device->path_data.npm = 0;
3681                 ret = dasd_generic_last_path_gone(device);
3682                 break;
3683         case CIO_OPER:
3684                 ret = 1;
3685                 if (device->path_data.opm)
3686                         ret = dasd_generic_path_operational(device);
3687                 break;
3688         }
3689         dasd_put_device(device);
3690         return ret;
3691 }
3692 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3693
3694 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3695 {
3696         int chp;
3697         __u8 oldopm, eventlpm;
3698         struct dasd_device *device;
3699
3700         device = dasd_device_from_cdev_locked(cdev);
3701         if (IS_ERR(device))
3702                 return;
3703         for (chp = 0; chp < 8; chp++) {
3704                 eventlpm = 0x80 >> chp;
3705                 if (path_event[chp] & PE_PATH_GONE) {
3706                         oldopm = device->path_data.opm;
3707                         device->path_data.opm &= ~eventlpm;
3708                         device->path_data.ppm &= ~eventlpm;
3709                         device->path_data.npm &= ~eventlpm;
3710                         if (oldopm && !device->path_data.opm) {
3711                                 dev_warn(&device->cdev->dev,
3712                                          "No verified channel paths remain "
3713                                          "for the device\n");
3714                                 DBF_DEV_EVENT(DBF_WARNING, device,
3715                                               "%s", "last verified path gone");
3716                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3717                                 dasd_device_set_stop_bits(device,
3718                                                           DASD_STOPPED_DC_WAIT);
3719                         }
3720                 }
3721                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3722                         device->path_data.opm &= ~eventlpm;
3723                         device->path_data.ppm &= ~eventlpm;
3724                         device->path_data.npm &= ~eventlpm;
3725                         device->path_data.tbvpm |= eventlpm;
3726                         dasd_schedule_device_bh(device);
3727                 }
3728                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3729                         if (!(device->path_data.opm & eventlpm) &&
3730                             !(device->path_data.tbvpm & eventlpm)) {
3731                                 /*
3732                                  * we can not establish a pathgroup on an
3733                                  * unavailable path, so trigger a path
3734                                  * verification first
3735                                  */
3736                                 device->path_data.tbvpm |= eventlpm;
3737                                 dasd_schedule_device_bh(device);
3738                         }
3739                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3740                                       "Pathgroup re-established\n");
3741                         if (device->discipline->kick_validate)
3742                                 device->discipline->kick_validate(device);
3743                 }
3744         }
3745         dasd_put_device(device);
3746 }
3747 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3748
3749 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3750 {
3751         if (!device->path_data.opm && lpm) {
3752                 device->path_data.opm = lpm;
3753                 dasd_generic_path_operational(device);
3754         } else
3755                 device->path_data.opm |= lpm;
3756         return 0;
3757 }
3758 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3759
3760
3761 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3762 {
3763         struct dasd_device *device = dasd_device_from_cdev(cdev);
3764         struct list_head freeze_queue;
3765         struct dasd_ccw_req *cqr, *n;
3766         struct dasd_ccw_req *refers;
3767         int rc;
3768
3769         if (IS_ERR(device))
3770                 return PTR_ERR(device);
3771
3772         /* mark device as suspended */
3773         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3774
3775         if (device->discipline->freeze)
3776                 rc = device->discipline->freeze(device);
3777
3778         /* disallow new I/O  */
3779         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3780
3781         /* clear active requests and requeue them to block layer if possible */
3782         INIT_LIST_HEAD(&freeze_queue);
3783         spin_lock_irq(get_ccwdev_lock(cdev));
3784         rc = 0;
3785         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3786                 /* Check status and move request to flush_queue */
3787                 if (cqr->status == DASD_CQR_IN_IO) {
3788                         rc = device->discipline->term_IO(cqr);
3789                         if (rc) {
3790                                 /* unable to terminate requeust */
3791                                 dev_err(&device->cdev->dev,
3792                                         "Unable to terminate request %p "
3793                                         "on suspend\n", cqr);
3794                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3795                                 dasd_put_device(device);
3796                                 return rc;
3797                         }
3798                 }
3799                 list_move_tail(&cqr->devlist, &freeze_queue);
3800         }
3801         spin_unlock_irq(get_ccwdev_lock(cdev));
3802
3803         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3804                 wait_event(dasd_flush_wq,
3805                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3806                 if (cqr->status == DASD_CQR_CLEARED)
3807                         cqr->status = DASD_CQR_QUEUED;
3808
3809                 /* requeue requests to blocklayer will only work for
3810                    block device requests */
3811                 if (_dasd_requeue_request(cqr))
3812                         continue;
3813
3814                 /* remove requests from device and block queue */
3815                 list_del_init(&cqr->devlist);
3816                 while (cqr->refers != NULL) {
3817                         refers = cqr->refers;
3818                         /* remove the request from the block queue */
3819                         list_del(&cqr->blocklist);
3820                         /* free the finished erp request */
3821                         dasd_free_erp_request(cqr, cqr->memdev);
3822                         cqr = refers;
3823                 }
3824                 if (cqr->block)
3825                         list_del_init(&cqr->blocklist);
3826                 cqr->block->base->discipline->free_cp(
3827                         cqr, (struct request *) cqr->callback_data);
3828         }
3829
3830         /*
3831          * if requests remain then they are internal request
3832          * and go back to the device queue
3833          */
3834         if (!list_empty(&freeze_queue)) {
3835                 /* move freeze_queue to start of the ccw_queue */
3836                 spin_lock_irq(get_ccwdev_lock(cdev));
3837                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3838                 spin_unlock_irq(get_ccwdev_lock(cdev));
3839         }
3840         dasd_put_device(device);
3841         return rc;
3842 }
3843 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3844
3845 int dasd_generic_restore_device(struct ccw_device *cdev)
3846 {
3847         struct dasd_device *device = dasd_device_from_cdev(cdev);
3848         int rc = 0;
3849
3850         if (IS_ERR(device))
3851                 return PTR_ERR(device);
3852
3853         /* allow new IO again */
3854         dasd_device_remove_stop_bits(device,
3855                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3856
3857         dasd_schedule_device_bh(device);
3858
3859         /*
3860          * call discipline restore function
3861          * if device is stopped do nothing e.g. for disconnected devices
3862          */
3863         if (device->discipline->restore && !(device->stopped))
3864                 rc = device->discipline->restore(device);
3865         if (rc || device->stopped)
3866                 /*
3867                  * if the resume failed for the DASD we put it in
3868                  * an UNRESUMED stop state
3869                  */
3870                 device->stopped |= DASD_UNRESUMED_PM;
3871
3872         if (device->block)
3873                 dasd_schedule_block_bh(device->block);
3874
3875         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3876         dasd_put_device(device);
3877         return 0;
3878 }
3879 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3880
3881 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3882                                                    void *rdc_buffer,
3883                                                    int rdc_buffer_size,
3884                                                    int magic)
3885 {
3886         struct dasd_ccw_req *cqr;
3887         struct ccw1 *ccw;
3888         unsigned long *idaw;
3889
3890         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3891
3892         if (IS_ERR(cqr)) {
3893                 /* internal error 13 - Allocating the RDC request failed*/
3894                 dev_err(&device->cdev->dev,
3895                          "An error occurred in the DASD device driver, "
3896                          "reason=%s\n", "13");
3897                 return cqr;
3898         }
3899
3900         ccw = cqr->cpaddr;
3901         ccw->cmd_code = CCW_CMD_RDC;
3902         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3903                 idaw = (unsigned long *) (cqr->data);
3904                 ccw->cda = (__u32)(addr_t) idaw;
3905                 ccw->flags = CCW_FLAG_IDA;
3906                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3907         } else {
3908                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3909                 ccw->flags = 0;
3910         }
3911
3912         ccw->count = rdc_buffer_size;
3913         cqr->startdev = device;
3914         cqr->memdev = device;
3915         cqr->expires = 10*HZ;
3916         cqr->retries = 256;
3917         cqr->buildclk = get_tod_clock();
3918         cqr->status = DASD_CQR_FILLED;
3919         return cqr;
3920 }
3921
3922
3923 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3924                                 void *rdc_buffer, int rdc_buffer_size)
3925 {
3926         int ret;
3927         struct dasd_ccw_req *cqr;
3928
3929         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3930                                      magic);
3931         if (IS_ERR(cqr))
3932                 return PTR_ERR(cqr);
3933
3934         ret = dasd_sleep_on(cqr);
3935         dasd_sfree_request(cqr, cqr->memdev);
3936         return ret;
3937 }
3938 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3939
3940 /*
3941  *   In command mode and transport mode we need to look for sense
3942  *   data in different places. The sense data itself is allways
3943  *   an array of 32 bytes, so we can unify the sense data access
3944  *   for both modes.
3945  */
3946 char *dasd_get_sense(struct irb *irb)
3947 {
3948         struct tsb *tsb = NULL;
3949         char *sense = NULL;
3950
3951         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3952                 if (irb->scsw.tm.tcw)
3953                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3954                                           irb->scsw.tm.tcw);
3955                 if (tsb && tsb->length == 64 && tsb->flags)
3956                         switch (tsb->flags & 0x07) {
3957                         case 1: /* tsa_iostat */
3958                                 sense = tsb->tsa.iostat.sense;
3959                                 break;
3960                         case 2: /* tsa_ddpc */
3961                                 sense = tsb->tsa.ddpc.sense;
3962                                 break;
3963                         default:
3964                                 /* currently we don't use interrogate data */
3965                                 break;
3966                         }
3967         } else if (irb->esw.esw0.erw.cons) {
3968                 sense = irb->ecw;
3969         }
3970         return sense;
3971 }
3972 EXPORT_SYMBOL_GPL(dasd_get_sense);
3973
3974 void dasd_generic_shutdown(struct ccw_device *cdev)
3975 {
3976         struct dasd_device *device;
3977
3978         device = dasd_device_from_cdev(cdev);
3979         if (IS_ERR(device))
3980                 return;
3981
3982         if (device->block)
3983                 dasd_schedule_block_bh(device->block);
3984
3985         dasd_schedule_device_bh(device);
3986
3987         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3988 }
3989 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3990
3991 static int __init dasd_init(void)
3992 {
3993         int rc;
3994
3995         init_waitqueue_head(&dasd_init_waitq);
3996         init_waitqueue_head(&dasd_flush_wq);
3997         init_waitqueue_head(&generic_waitq);
3998         init_waitqueue_head(&shutdown_waitq);
3999
4000         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4001         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4002         if (dasd_debug_area == NULL) {
4003                 rc = -ENOMEM;
4004                 goto failed;
4005         }
4006         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4007         debug_set_level(dasd_debug_area, DBF_WARNING);
4008
4009         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4010
4011         dasd_diag_discipline_pointer = NULL;
4012
4013         dasd_statistics_createroot();
4014
4015         rc = dasd_devmap_init();
4016         if (rc)
4017                 goto failed;
4018         rc = dasd_gendisk_init();
4019         if (rc)
4020                 goto failed;
4021         rc = dasd_parse();
4022         if (rc)
4023                 goto failed;
4024         rc = dasd_eer_init();
4025         if (rc)
4026                 goto failed;
4027 #ifdef CONFIG_PROC_FS
4028         rc = dasd_proc_init();
4029         if (rc)
4030                 goto failed;
4031 #endif
4032
4033         return 0;
4034 failed:
4035         pr_info("The DASD device driver could not be initialized\n");
4036         dasd_exit();
4037         return rc;
4038 }
4039
4040 module_init(dasd_init);
4041 module_exit(dasd_exit);