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                 if (!IS_ERR(device)) {
1708                         device->discipline->check_attention(device,
1709                                                             irb->esw.esw1.lpum);
1710                         dasd_put_device(device);
1711                 }
1712         }
1713
1714         if (!cqr)
1715                 return;
1716
1717         device = (struct dasd_device *) cqr->startdev;
1718         if (!device ||
1719             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1720                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1721                                 "invalid device in request");
1722                 return;
1723         }
1724
1725         /* Check for clear pending */
1726         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1727             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1728                 cqr->status = DASD_CQR_CLEARED;
1729                 dasd_device_clear_timer(device);
1730                 wake_up(&dasd_flush_wq);
1731                 dasd_schedule_device_bh(device);
1732                 return;
1733         }
1734
1735         /* check status - the request might have been killed by dyn detach */
1736         if (cqr->status != DASD_CQR_IN_IO) {
1737                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1738                               "status %02x", dev_name(&cdev->dev), cqr->status);
1739                 return;
1740         }
1741
1742         next = NULL;
1743         expires = 0;
1744         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1745             scsw_cstat(&irb->scsw) == 0) {
1746                 /* request was completed successfully */
1747                 cqr->status = DASD_CQR_SUCCESS;
1748                 cqr->stopclk = now;
1749                 /* Start first request on queue if possible -> fast_io. */
1750                 if (cqr->devlist.next != &device->ccw_queue) {
1751                         next = list_entry(cqr->devlist.next,
1752                                           struct dasd_ccw_req, devlist);
1753                 }
1754         } else {  /* error */
1755                 /*
1756                  * If we don't want complex ERP for this request, then just
1757                  * reset this and retry it in the fastpath
1758                  */
1759                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1760                     cqr->retries > 0) {
1761                         if (cqr->lpm == device->path_data.opm)
1762                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1763                                               "default ERP in fastpath "
1764                                               "(%i retries left)",
1765                                               cqr->retries);
1766                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1767                                 cqr->lpm = device->path_data.opm;
1768                         cqr->status = DASD_CQR_QUEUED;
1769                         next = cqr;
1770                 } else
1771                         cqr->status = DASD_CQR_ERROR;
1772         }
1773         if (next && (next->status == DASD_CQR_QUEUED) &&
1774             (!device->stopped)) {
1775                 if (device->discipline->start_IO(next) == 0)
1776                         expires = next->expires;
1777         }
1778         if (expires != 0)
1779                 dasd_device_set_timer(device, expires);
1780         else
1781                 dasd_device_clear_timer(device);
1782         dasd_schedule_device_bh(device);
1783 }
1784 EXPORT_SYMBOL(dasd_int_handler);
1785
1786 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1787 {
1788         struct dasd_device *device;
1789
1790         device = dasd_device_from_cdev_locked(cdev);
1791
1792         if (IS_ERR(device))
1793                 goto out;
1794         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1795            device->state != device->target ||
1796            !device->discipline->check_for_device_change){
1797                 dasd_put_device(device);
1798                 goto out;
1799         }
1800         if (device->discipline->dump_sense_dbf)
1801                 device->discipline->dump_sense_dbf(device, irb, "uc");
1802         device->discipline->check_for_device_change(device, NULL, irb);
1803         dasd_put_device(device);
1804 out:
1805         return UC_TODO_RETRY;
1806 }
1807 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1808
1809 /*
1810  * If we have an error on a dasd_block layer request then we cancel
1811  * and return all further requests from the same dasd_block as well.
1812  */
1813 static void __dasd_device_recovery(struct dasd_device *device,
1814                                    struct dasd_ccw_req *ref_cqr)
1815 {
1816         struct list_head *l, *n;
1817         struct dasd_ccw_req *cqr;
1818
1819         /*
1820          * only requeue request that came from the dasd_block layer
1821          */
1822         if (!ref_cqr->block)
1823                 return;
1824
1825         list_for_each_safe(l, n, &device->ccw_queue) {
1826                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1827                 if (cqr->status == DASD_CQR_QUEUED &&
1828                     ref_cqr->block == cqr->block) {
1829                         cqr->status = DASD_CQR_CLEARED;
1830                 }
1831         }
1832 };
1833
1834 /*
1835  * Remove those ccw requests from the queue that need to be returned
1836  * to the upper layer.
1837  */
1838 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1839                                             struct list_head *final_queue)
1840 {
1841         struct list_head *l, *n;
1842         struct dasd_ccw_req *cqr;
1843
1844         /* Process request with final status. */
1845         list_for_each_safe(l, n, &device->ccw_queue) {
1846                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1847
1848                 /* Skip any non-final request. */
1849                 if (cqr->status == DASD_CQR_QUEUED ||
1850                     cqr->status == DASD_CQR_IN_IO ||
1851                     cqr->status == DASD_CQR_CLEAR_PENDING)
1852                         continue;
1853                 if (cqr->status == DASD_CQR_ERROR) {
1854                         __dasd_device_recovery(device, cqr);
1855                 }
1856                 /* Rechain finished requests to final queue */
1857                 list_move_tail(&cqr->devlist, final_queue);
1858         }
1859 }
1860
1861 /*
1862  * the cqrs from the final queue are returned to the upper layer
1863  * by setting a dasd_block state and calling the callback function
1864  */
1865 static void __dasd_device_process_final_queue(struct dasd_device *device,
1866                                               struct list_head *final_queue)
1867 {
1868         struct list_head *l, *n;
1869         struct dasd_ccw_req *cqr;
1870         struct dasd_block *block;
1871         void (*callback)(struct dasd_ccw_req *, void *data);
1872         void *callback_data;
1873         char errorstring[ERRORLENGTH];
1874
1875         list_for_each_safe(l, n, final_queue) {
1876                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1877                 list_del_init(&cqr->devlist);
1878                 block = cqr->block;
1879                 callback = cqr->callback;
1880                 callback_data = cqr->callback_data;
1881                 if (block)
1882                         spin_lock_bh(&block->queue_lock);
1883                 switch (cqr->status) {
1884                 case DASD_CQR_SUCCESS:
1885                         cqr->status = DASD_CQR_DONE;
1886                         break;
1887                 case DASD_CQR_ERROR:
1888                         cqr->status = DASD_CQR_NEED_ERP;
1889                         break;
1890                 case DASD_CQR_CLEARED:
1891                         cqr->status = DASD_CQR_TERMINATED;
1892                         break;
1893                 default:
1894                         /* internal error 12 - wrong cqr status*/
1895                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1896                         dev_err(&device->cdev->dev,
1897                                 "An error occurred in the DASD device driver, "
1898                                 "reason=%s\n", errorstring);
1899                         BUG();
1900                 }
1901                 if (cqr->callback != NULL)
1902                         (callback)(cqr, callback_data);
1903                 if (block)
1904                         spin_unlock_bh(&block->queue_lock);
1905         }
1906 }
1907
1908 /*
1909  * Take a look at the first request on the ccw queue and check
1910  * if it reached its expire time. If so, terminate the IO.
1911  */
1912 static void __dasd_device_check_expire(struct dasd_device *device)
1913 {
1914         struct dasd_ccw_req *cqr;
1915
1916         if (list_empty(&device->ccw_queue))
1917                 return;
1918         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1919         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1920             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1921                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1922                         /*
1923                          * IO in safe offline processing should not
1924                          * run out of retries
1925                          */
1926                         cqr->retries++;
1927                 }
1928                 if (device->discipline->term_IO(cqr) != 0) {
1929                         /* Hmpf, try again in 5 sec */
1930                         dev_err(&device->cdev->dev,
1931                                 "cqr %p timed out (%lus) but cannot be "
1932                                 "ended, retrying in 5 s\n",
1933                                 cqr, (cqr->expires/HZ));
1934                         cqr->expires += 5*HZ;
1935                         dasd_device_set_timer(device, 5*HZ);
1936                 } else {
1937                         dev_err(&device->cdev->dev,
1938                                 "cqr %p timed out (%lus), %i retries "
1939                                 "remaining\n", cqr, (cqr->expires/HZ),
1940                                 cqr->retries);
1941                 }
1942         }
1943 }
1944
1945 /*
1946  * return 1 when device is not eligible for IO
1947  */
1948 static int __dasd_device_is_unusable(struct dasd_device *device,
1949                                      struct dasd_ccw_req *cqr)
1950 {
1951         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1952
1953         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1954             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1955                 /*
1956                  * dasd is being set offline
1957                  * but it is no safe offline where we have to allow I/O
1958                  */
1959                 return 1;
1960         }
1961         if (device->stopped) {
1962                 if (device->stopped & mask) {
1963                         /* stopped and CQR will not change that. */
1964                         return 1;
1965                 }
1966                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1967                         /* CQR is not able to change device to
1968                          * operational. */
1969                         return 1;
1970                 }
1971                 /* CQR required to get device operational. */
1972         }
1973         return 0;
1974 }
1975
1976 /*
1977  * Take a look at the first request on the ccw queue and check
1978  * if it needs to be started.
1979  */
1980 static void __dasd_device_start_head(struct dasd_device *device)
1981 {
1982         struct dasd_ccw_req *cqr;
1983         int rc;
1984
1985         if (list_empty(&device->ccw_queue))
1986                 return;
1987         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1988         if (cqr->status != DASD_CQR_QUEUED)
1989                 return;
1990         /* if device is not usable return request to upper layer */
1991         if (__dasd_device_is_unusable(device, cqr)) {
1992                 cqr->intrc = -EAGAIN;
1993                 cqr->status = DASD_CQR_CLEARED;
1994                 dasd_schedule_device_bh(device);
1995                 return;
1996         }
1997
1998         rc = device->discipline->start_IO(cqr);
1999         if (rc == 0)
2000                 dasd_device_set_timer(device, cqr->expires);
2001         else if (rc == -EACCES) {
2002                 dasd_schedule_device_bh(device);
2003         } else
2004                 /* Hmpf, try again in 1/2 sec */
2005                 dasd_device_set_timer(device, 50);
2006 }
2007
2008 static void __dasd_device_check_path_events(struct dasd_device *device)
2009 {
2010         int rc;
2011
2012         if (device->path_data.tbvpm) {
2013                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
2014                                         DASD_UNRESUMED_PM))
2015                         return;
2016                 rc = device->discipline->verify_path(
2017                         device, device->path_data.tbvpm);
2018                 if (rc)
2019                         dasd_device_set_timer(device, 50);
2020                 else
2021                         device->path_data.tbvpm = 0;
2022         }
2023 };
2024
2025 /*
2026  * Go through all request on the dasd_device request queue,
2027  * terminate them on the cdev if necessary, and return them to the
2028  * submitting layer via callback.
2029  * Note:
2030  * Make sure that all 'submitting layers' still exist when
2031  * this function is called!. In other words, when 'device' is a base
2032  * device then all block layer requests must have been removed before
2033  * via dasd_flush_block_queue.
2034  */
2035 int dasd_flush_device_queue(struct dasd_device *device)
2036 {
2037         struct dasd_ccw_req *cqr, *n;
2038         int rc;
2039         struct list_head flush_queue;
2040
2041         INIT_LIST_HEAD(&flush_queue);
2042         spin_lock_irq(get_ccwdev_lock(device->cdev));
2043         rc = 0;
2044         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2045                 /* Check status and move request to flush_queue */
2046                 switch (cqr->status) {
2047                 case DASD_CQR_IN_IO:
2048                         rc = device->discipline->term_IO(cqr);
2049                         if (rc) {
2050                                 /* unable to terminate requeust */
2051                                 dev_err(&device->cdev->dev,
2052                                         "Flushing the DASD request queue "
2053                                         "failed for request %p\n", cqr);
2054                                 /* stop flush processing */
2055                                 goto finished;
2056                         }
2057                         break;
2058                 case DASD_CQR_QUEUED:
2059                         cqr->stopclk = get_tod_clock();
2060                         cqr->status = DASD_CQR_CLEARED;
2061                         break;
2062                 default: /* no need to modify the others */
2063                         break;
2064                 }
2065                 list_move_tail(&cqr->devlist, &flush_queue);
2066         }
2067 finished:
2068         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2069         /*
2070          * After this point all requests must be in state CLEAR_PENDING,
2071          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2072          * one of the others.
2073          */
2074         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2075                 wait_event(dasd_flush_wq,
2076                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2077         /*
2078          * Now set each request back to TERMINATED, DONE or NEED_ERP
2079          * and call the callback function of flushed requests
2080          */
2081         __dasd_device_process_final_queue(device, &flush_queue);
2082         return rc;
2083 }
2084 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2085
2086 /*
2087  * Acquire the device lock and process queues for the device.
2088  */
2089 static void dasd_device_tasklet(struct dasd_device *device)
2090 {
2091         struct list_head final_queue;
2092
2093         atomic_set (&device->tasklet_scheduled, 0);
2094         INIT_LIST_HEAD(&final_queue);
2095         spin_lock_irq(get_ccwdev_lock(device->cdev));
2096         /* Check expire time of first request on the ccw queue. */
2097         __dasd_device_check_expire(device);
2098         /* find final requests on ccw queue */
2099         __dasd_device_process_ccw_queue(device, &final_queue);
2100         __dasd_device_check_path_events(device);
2101         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2102         /* Now call the callback function of requests with final status */
2103         __dasd_device_process_final_queue(device, &final_queue);
2104         spin_lock_irq(get_ccwdev_lock(device->cdev));
2105         /* Now check if the head of the ccw queue needs to be started. */
2106         __dasd_device_start_head(device);
2107         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2108         if (waitqueue_active(&shutdown_waitq))
2109                 wake_up(&shutdown_waitq);
2110         dasd_put_device(device);
2111 }
2112
2113 /*
2114  * Schedules a call to dasd_tasklet over the device tasklet.
2115  */
2116 void dasd_schedule_device_bh(struct dasd_device *device)
2117 {
2118         /* Protect against rescheduling. */
2119         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2120                 return;
2121         dasd_get_device(device);
2122         tasklet_hi_schedule(&device->tasklet);
2123 }
2124 EXPORT_SYMBOL(dasd_schedule_device_bh);
2125
2126 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2127 {
2128         device->stopped |= bits;
2129 }
2130 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2131
2132 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2133 {
2134         device->stopped &= ~bits;
2135         if (!device->stopped)
2136                 wake_up(&generic_waitq);
2137 }
2138 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2139
2140 /*
2141  * Queue a request to the head of the device ccw_queue.
2142  * Start the I/O if possible.
2143  */
2144 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2145 {
2146         struct dasd_device *device;
2147         unsigned long flags;
2148
2149         device = cqr->startdev;
2150         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2151         cqr->status = DASD_CQR_QUEUED;
2152         list_add(&cqr->devlist, &device->ccw_queue);
2153         /* let the bh start the request to keep them in order */
2154         dasd_schedule_device_bh(device);
2155         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2156 }
2157 EXPORT_SYMBOL(dasd_add_request_head);
2158
2159 /*
2160  * Queue a request to the tail of the device ccw_queue.
2161  * Start the I/O if possible.
2162  */
2163 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2164 {
2165         struct dasd_device *device;
2166         unsigned long flags;
2167
2168         device = cqr->startdev;
2169         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2170         cqr->status = DASD_CQR_QUEUED;
2171         list_add_tail(&cqr->devlist, &device->ccw_queue);
2172         /* let the bh start the request to keep them in order */
2173         dasd_schedule_device_bh(device);
2174         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2175 }
2176 EXPORT_SYMBOL(dasd_add_request_tail);
2177
2178 /*
2179  * Wakeup helper for the 'sleep_on' functions.
2180  */
2181 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2182 {
2183         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2184         cqr->callback_data = DASD_SLEEPON_END_TAG;
2185         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2186         wake_up(&generic_waitq);
2187 }
2188 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2189
2190 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2191 {
2192         struct dasd_device *device;
2193         int rc;
2194
2195         device = cqr->startdev;
2196         spin_lock_irq(get_ccwdev_lock(device->cdev));
2197         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2198         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2199         return rc;
2200 }
2201
2202 /*
2203  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2204  */
2205 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2206 {
2207         struct dasd_device *device;
2208         dasd_erp_fn_t erp_fn;
2209
2210         if (cqr->status == DASD_CQR_FILLED)
2211                 return 0;
2212         device = cqr->startdev;
2213         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2214                 if (cqr->status == DASD_CQR_TERMINATED) {
2215                         device->discipline->handle_terminated_request(cqr);
2216                         return 1;
2217                 }
2218                 if (cqr->status == DASD_CQR_NEED_ERP) {
2219                         erp_fn = device->discipline->erp_action(cqr);
2220                         erp_fn(cqr);
2221                         return 1;
2222                 }
2223                 if (cqr->status == DASD_CQR_FAILED)
2224                         dasd_log_sense(cqr, &cqr->irb);
2225                 if (cqr->refers) {
2226                         __dasd_process_erp(device, cqr);
2227                         return 1;
2228                 }
2229         }
2230         return 0;
2231 }
2232
2233 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2234 {
2235         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2236                 if (cqr->refers) /* erp is not done yet */
2237                         return 1;
2238                 return ((cqr->status != DASD_CQR_DONE) &&
2239                         (cqr->status != DASD_CQR_FAILED));
2240         } else
2241                 return (cqr->status == DASD_CQR_FILLED);
2242 }
2243
2244 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2245 {
2246         struct dasd_device *device;
2247         int rc;
2248         struct list_head ccw_queue;
2249         struct dasd_ccw_req *cqr;
2250
2251         INIT_LIST_HEAD(&ccw_queue);
2252         maincqr->status = DASD_CQR_FILLED;
2253         device = maincqr->startdev;
2254         list_add(&maincqr->blocklist, &ccw_queue);
2255         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2256              cqr = list_first_entry(&ccw_queue,
2257                                     struct dasd_ccw_req, blocklist)) {
2258
2259                 if (__dasd_sleep_on_erp(cqr))
2260                         continue;
2261                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2262                         continue;
2263                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2264                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2265                         cqr->status = DASD_CQR_FAILED;
2266                         cqr->intrc = -EPERM;
2267                         continue;
2268                 }
2269                 /* Non-temporary stop condition will trigger fail fast */
2270                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2271                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2272                     (!dasd_eer_enabled(device))) {
2273                         cqr->status = DASD_CQR_FAILED;
2274                         cqr->intrc = -ENOLINK;
2275                         continue;
2276                 }
2277                 /*
2278                  * Don't try to start requests if device is in
2279                  * offline processing, it might wait forever
2280                  */
2281                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2282                         cqr->status = DASD_CQR_FAILED;
2283                         cqr->intrc = -ENODEV;
2284                         continue;
2285                 }
2286                 /*
2287                  * Don't try to start requests if device is stopped
2288                  * except path verification requests
2289                  */
2290                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2291                         if (interruptible) {
2292                                 rc = wait_event_interruptible(
2293                                         generic_waitq, !(device->stopped));
2294                                 if (rc == -ERESTARTSYS) {
2295                                         cqr->status = DASD_CQR_FAILED;
2296                                         maincqr->intrc = rc;
2297                                         continue;
2298                                 }
2299                         } else
2300                                 wait_event(generic_waitq, !(device->stopped));
2301                 }
2302                 if (!cqr->callback)
2303                         cqr->callback = dasd_wakeup_cb;
2304
2305                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2306                 dasd_add_request_tail(cqr);
2307                 if (interruptible) {
2308                         rc = wait_event_interruptible(
2309                                 generic_waitq, _wait_for_wakeup(cqr));
2310                         if (rc == -ERESTARTSYS) {
2311                                 dasd_cancel_req(cqr);
2312                                 /* wait (non-interruptible) for final status */
2313                                 wait_event(generic_waitq,
2314                                            _wait_for_wakeup(cqr));
2315                                 cqr->status = DASD_CQR_FAILED;
2316                                 maincqr->intrc = rc;
2317                                 continue;
2318                         }
2319                 } else
2320                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2321         }
2322
2323         maincqr->endclk = get_tod_clock();
2324         if ((maincqr->status != DASD_CQR_DONE) &&
2325             (maincqr->intrc != -ERESTARTSYS))
2326                 dasd_log_sense(maincqr, &maincqr->irb);
2327         if (maincqr->status == DASD_CQR_DONE)
2328                 rc = 0;
2329         else if (maincqr->intrc)
2330                 rc = maincqr->intrc;
2331         else
2332                 rc = -EIO;
2333         return rc;
2334 }
2335
2336 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2337 {
2338         struct dasd_ccw_req *cqr;
2339
2340         list_for_each_entry(cqr, ccw_queue, blocklist) {
2341                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2342                         return 0;
2343         }
2344
2345         return 1;
2346 }
2347
2348 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2349 {
2350         struct dasd_device *device;
2351         struct dasd_ccw_req *cqr, *n;
2352         u8 *sense = NULL;
2353         int rc;
2354
2355 retry:
2356         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2357                 device = cqr->startdev;
2358                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2359                         continue;
2360
2361                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2362                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2363                         cqr->status = DASD_CQR_FAILED;
2364                         cqr->intrc = -EPERM;
2365                         continue;
2366                 }
2367                 /*Non-temporary stop condition will trigger fail fast*/
2368                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2369                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2370                     !dasd_eer_enabled(device)) {
2371                         cqr->status = DASD_CQR_FAILED;
2372                         cqr->intrc = -EAGAIN;
2373                         continue;
2374                 }
2375
2376                 /*Don't try to start requests if device is stopped*/
2377                 if (interruptible) {
2378                         rc = wait_event_interruptible(
2379                                 generic_waitq, !device->stopped);
2380                         if (rc == -ERESTARTSYS) {
2381                                 cqr->status = DASD_CQR_FAILED;
2382                                 cqr->intrc = rc;
2383                                 continue;
2384                         }
2385                 } else
2386                         wait_event(generic_waitq, !(device->stopped));
2387
2388                 if (!cqr->callback)
2389                         cqr->callback = dasd_wakeup_cb;
2390                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2391                 dasd_add_request_tail(cqr);
2392         }
2393
2394         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2395
2396         rc = 0;
2397         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2398                 /*
2399                  * In some cases the 'File Protected' or 'Incorrect Length'
2400                  * error might be expected and error recovery would be
2401                  * unnecessary in these cases.  Check if the according suppress
2402                  * bit is set.
2403                  */
2404                 sense = dasd_get_sense(&cqr->irb);
2405                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2406                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2407                         continue;
2408                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2409                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2410                         continue;
2411
2412                 /*
2413                  * for alias devices simplify error recovery and
2414                  * return to upper layer
2415                  * do not skip ERP requests
2416                  */
2417                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2418                     (cqr->status == DASD_CQR_TERMINATED ||
2419                      cqr->status == DASD_CQR_NEED_ERP))
2420                         return -EAGAIN;
2421
2422                 /* normal recovery for basedev IO */
2423                 if (__dasd_sleep_on_erp(cqr))
2424                         /* handle erp first */
2425                         goto retry;
2426         }
2427
2428         return 0;
2429 }
2430
2431 /*
2432  * Queue a request to the tail of the device ccw_queue and wait for
2433  * it's completion.
2434  */
2435 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2436 {
2437         return _dasd_sleep_on(cqr, 0);
2438 }
2439 EXPORT_SYMBOL(dasd_sleep_on);
2440
2441 /*
2442  * Start requests from a ccw_queue and wait for their completion.
2443  */
2444 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2445 {
2446         return _dasd_sleep_on_queue(ccw_queue, 0);
2447 }
2448 EXPORT_SYMBOL(dasd_sleep_on_queue);
2449
2450 /*
2451  * Queue a request to the tail of the device ccw_queue and wait
2452  * interruptible for it's completion.
2453  */
2454 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2455 {
2456         return _dasd_sleep_on(cqr, 1);
2457 }
2458 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2459
2460 /*
2461  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2462  * for eckd devices) the currently running request has to be terminated
2463  * and be put back to status queued, before the special request is added
2464  * to the head of the queue. Then the special request is waited on normally.
2465  */
2466 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2467 {
2468         struct dasd_ccw_req *cqr;
2469         int rc;
2470
2471         if (list_empty(&device->ccw_queue))
2472                 return 0;
2473         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2474         rc = device->discipline->term_IO(cqr);
2475         if (!rc)
2476                 /*
2477                  * CQR terminated because a more important request is pending.
2478                  * Undo decreasing of retry counter because this is
2479                  * not an error case.
2480                  */
2481                 cqr->retries++;
2482         return rc;
2483 }
2484
2485 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2486 {
2487         struct dasd_device *device;
2488         int rc;
2489
2490         device = cqr->startdev;
2491         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2492             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2493                 cqr->status = DASD_CQR_FAILED;
2494                 cqr->intrc = -EPERM;
2495                 return -EIO;
2496         }
2497         spin_lock_irq(get_ccwdev_lock(device->cdev));
2498         rc = _dasd_term_running_cqr(device);
2499         if (rc) {
2500                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2501                 return rc;
2502         }
2503         cqr->callback = dasd_wakeup_cb;
2504         cqr->callback_data = DASD_SLEEPON_START_TAG;
2505         cqr->status = DASD_CQR_QUEUED;
2506         /*
2507          * add new request as second
2508          * first the terminated cqr needs to be finished
2509          */
2510         list_add(&cqr->devlist, device->ccw_queue.next);
2511
2512         /* let the bh start the request to keep them in order */
2513         dasd_schedule_device_bh(device);
2514
2515         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2516
2517         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2518
2519         if (cqr->status == DASD_CQR_DONE)
2520                 rc = 0;
2521         else if (cqr->intrc)
2522                 rc = cqr->intrc;
2523         else
2524                 rc = -EIO;
2525
2526         /* kick tasklets */
2527         dasd_schedule_device_bh(device);
2528         if (device->block)
2529                 dasd_schedule_block_bh(device->block);
2530
2531         return rc;
2532 }
2533 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2534
2535 /*
2536  * Cancels a request that was started with dasd_sleep_on_req.
2537  * This is useful to timeout requests. The request will be
2538  * terminated if it is currently in i/o.
2539  * Returns 0 if request termination was successful
2540  *         negative error code if termination failed
2541  * Cancellation of a request is an asynchronous operation! The calling
2542  * function has to wait until the request is properly returned via callback.
2543  */
2544 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2545 {
2546         struct dasd_device *device = cqr->startdev;
2547         unsigned long flags;
2548         int rc;
2549
2550         rc = 0;
2551         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2552         switch (cqr->status) {
2553         case DASD_CQR_QUEUED:
2554                 /* request was not started - just set to cleared */
2555                 cqr->status = DASD_CQR_CLEARED;
2556                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2557                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2558                 break;
2559         case DASD_CQR_IN_IO:
2560                 /* request in IO - terminate IO and release again */
2561                 rc = device->discipline->term_IO(cqr);
2562                 if (rc) {
2563                         dev_err(&device->cdev->dev,
2564                                 "Cancelling request %p failed with rc=%d\n",
2565                                 cqr, rc);
2566                 } else {
2567                         cqr->stopclk = get_tod_clock();
2568                 }
2569                 break;
2570         default: /* already finished or clear pending - do nothing */
2571                 break;
2572         }
2573         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2574         dasd_schedule_device_bh(device);
2575         return rc;
2576 }
2577 EXPORT_SYMBOL(dasd_cancel_req);
2578
2579 /*
2580  * SECTION: Operations of the dasd_block layer.
2581  */
2582
2583 /*
2584  * Timeout function for dasd_block. This is used when the block layer
2585  * is waiting for something that may not come reliably, (e.g. a state
2586  * change interrupt)
2587  */
2588 static void dasd_block_timeout(unsigned long ptr)
2589 {
2590         unsigned long flags;
2591         struct dasd_block *block;
2592
2593         block = (struct dasd_block *) ptr;
2594         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2595         /* re-activate request queue */
2596         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2597         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2598         dasd_schedule_block_bh(block);
2599 }
2600
2601 /*
2602  * Setup timeout for a dasd_block in jiffies.
2603  */
2604 void dasd_block_set_timer(struct dasd_block *block, int expires)
2605 {
2606         if (expires == 0)
2607                 del_timer(&block->timer);
2608         else
2609                 mod_timer(&block->timer, jiffies + expires);
2610 }
2611 EXPORT_SYMBOL(dasd_block_set_timer);
2612
2613 /*
2614  * Clear timeout for a dasd_block.
2615  */
2616 void dasd_block_clear_timer(struct dasd_block *block)
2617 {
2618         del_timer(&block->timer);
2619 }
2620 EXPORT_SYMBOL(dasd_block_clear_timer);
2621
2622 /*
2623  * Process finished error recovery ccw.
2624  */
2625 static void __dasd_process_erp(struct dasd_device *device,
2626                                struct dasd_ccw_req *cqr)
2627 {
2628         dasd_erp_fn_t erp_fn;
2629
2630         if (cqr->status == DASD_CQR_DONE)
2631                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2632         else
2633                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2634         erp_fn = device->discipline->erp_postaction(cqr);
2635         erp_fn(cqr);
2636 }
2637
2638 /*
2639  * Fetch requests from the block device queue.
2640  */
2641 static void __dasd_process_request_queue(struct dasd_block *block)
2642 {
2643         struct request_queue *queue;
2644         struct request *req;
2645         struct dasd_ccw_req *cqr;
2646         struct dasd_device *basedev;
2647         unsigned long flags;
2648         queue = block->request_queue;
2649         basedev = block->base;
2650         /* No queue ? Then there is nothing to do. */
2651         if (queue == NULL)
2652                 return;
2653
2654         /*
2655          * We requeue request from the block device queue to the ccw
2656          * queue only in two states. In state DASD_STATE_READY the
2657          * partition detection is done and we need to requeue requests
2658          * for that. State DASD_STATE_ONLINE is normal block device
2659          * operation.
2660          */
2661         if (basedev->state < DASD_STATE_READY) {
2662                 while ((req = blk_fetch_request(block->request_queue)))
2663                         __blk_end_request_all(req, -EIO);
2664                 return;
2665         }
2666
2667         /*
2668          * if device is stopped do not fetch new requests
2669          * except failfast is active which will let requests fail
2670          * immediately in __dasd_block_start_head()
2671          */
2672         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST))
2673                 return;
2674
2675         /* Now we try to fetch requests from the request queue */
2676         while ((req = blk_peek_request(queue))) {
2677                 if (basedev->features & DASD_FEATURE_READONLY &&
2678                     rq_data_dir(req) == WRITE) {
2679                         DBF_DEV_EVENT(DBF_ERR, basedev,
2680                                       "Rejecting write request %p",
2681                                       req);
2682                         blk_start_request(req);
2683                         __blk_end_request_all(req, -EIO);
2684                         continue;
2685                 }
2686                 if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2687                     (basedev->features & DASD_FEATURE_FAILFAST ||
2688                      blk_noretry_request(req))) {
2689                         DBF_DEV_EVENT(DBF_ERR, basedev,
2690                                       "Rejecting failfast request %p",
2691                                       req);
2692                         blk_start_request(req);
2693                         __blk_end_request_all(req, -ETIMEDOUT);
2694                         continue;
2695                 }
2696                 cqr = basedev->discipline->build_cp(basedev, block, req);
2697                 if (IS_ERR(cqr)) {
2698                         if (PTR_ERR(cqr) == -EBUSY)
2699                                 break;  /* normal end condition */
2700                         if (PTR_ERR(cqr) == -ENOMEM)
2701                                 break;  /* terminate request queue loop */
2702                         if (PTR_ERR(cqr) == -EAGAIN) {
2703                                 /*
2704                                  * The current request cannot be build right
2705                                  * now, we have to try later. If this request
2706                                  * is the head-of-queue we stop the device
2707                                  * for 1/2 second.
2708                                  */
2709                                 if (!list_empty(&block->ccw_queue))
2710                                         break;
2711                                 spin_lock_irqsave(
2712                                         get_ccwdev_lock(basedev->cdev), flags);
2713                                 dasd_device_set_stop_bits(basedev,
2714                                                           DASD_STOPPED_PENDING);
2715                                 spin_unlock_irqrestore(
2716                                         get_ccwdev_lock(basedev->cdev), flags);
2717                                 dasd_block_set_timer(block, HZ/2);
2718                                 break;
2719                         }
2720                         DBF_DEV_EVENT(DBF_ERR, basedev,
2721                                       "CCW creation failed (rc=%ld) "
2722                                       "on request %p",
2723                                       PTR_ERR(cqr), req);
2724                         blk_start_request(req);
2725                         __blk_end_request_all(req, -EIO);
2726                         continue;
2727                 }
2728                 /*
2729                  *  Note: callback is set to dasd_return_cqr_cb in
2730                  * __dasd_block_start_head to cover erp requests as well
2731                  */
2732                 cqr->callback_data = (void *) req;
2733                 cqr->status = DASD_CQR_FILLED;
2734                 req->completion_data = cqr;
2735                 blk_start_request(req);
2736                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2737                 INIT_LIST_HEAD(&cqr->devlist);
2738                 dasd_profile_start(block, cqr, req);
2739         }
2740 }
2741
2742 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2743 {
2744         struct request *req;
2745         int status;
2746         int error = 0;
2747
2748         req = (struct request *) cqr->callback_data;
2749         dasd_profile_end(cqr->block, cqr, req);
2750         status = cqr->block->base->discipline->free_cp(cqr, req);
2751         if (status < 0)
2752                 error = status;
2753         else if (status == 0) {
2754                 if (cqr->intrc == -EPERM)
2755                         error = -EBADE;
2756                 else if (cqr->intrc == -ENOLINK ||
2757                          cqr->intrc == -ETIMEDOUT)
2758                         error = cqr->intrc;
2759                 else
2760                         error = -EIO;
2761         }
2762         __blk_end_request_all(req, error);
2763 }
2764
2765 /*
2766  * Process ccw request queue.
2767  */
2768 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2769                                            struct list_head *final_queue)
2770 {
2771         struct list_head *l, *n;
2772         struct dasd_ccw_req *cqr;
2773         dasd_erp_fn_t erp_fn;
2774         unsigned long flags;
2775         struct dasd_device *base = block->base;
2776
2777 restart:
2778         /* Process request with final status. */
2779         list_for_each_safe(l, n, &block->ccw_queue) {
2780                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2781                 if (cqr->status != DASD_CQR_DONE &&
2782                     cqr->status != DASD_CQR_FAILED &&
2783                     cqr->status != DASD_CQR_NEED_ERP &&
2784                     cqr->status != DASD_CQR_TERMINATED)
2785                         continue;
2786
2787                 if (cqr->status == DASD_CQR_TERMINATED) {
2788                         base->discipline->handle_terminated_request(cqr);
2789                         goto restart;
2790                 }
2791
2792                 /*  Process requests that may be recovered */
2793                 if (cqr->status == DASD_CQR_NEED_ERP) {
2794                         erp_fn = base->discipline->erp_action(cqr);
2795                         if (IS_ERR(erp_fn(cqr)))
2796                                 continue;
2797                         goto restart;
2798                 }
2799
2800                 /* log sense for fatal error */
2801                 if (cqr->status == DASD_CQR_FAILED) {
2802                         dasd_log_sense(cqr, &cqr->irb);
2803                 }
2804
2805                 /* First of all call extended error reporting. */
2806                 if (dasd_eer_enabled(base) &&
2807                     cqr->status == DASD_CQR_FAILED) {
2808                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2809
2810                         /* restart request  */
2811                         cqr->status = DASD_CQR_FILLED;
2812                         cqr->retries = 255;
2813                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2814                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2815                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2816                                                flags);
2817                         goto restart;
2818                 }
2819
2820                 /* Process finished ERP request. */
2821                 if (cqr->refers) {
2822                         __dasd_process_erp(base, cqr);
2823                         goto restart;
2824                 }
2825
2826                 /* Rechain finished requests to final queue */
2827                 cqr->endclk = get_tod_clock();
2828                 list_move_tail(&cqr->blocklist, final_queue);
2829         }
2830 }
2831
2832 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2833 {
2834         dasd_schedule_block_bh(cqr->block);
2835 }
2836
2837 static void __dasd_block_start_head(struct dasd_block *block)
2838 {
2839         struct dasd_ccw_req *cqr;
2840
2841         if (list_empty(&block->ccw_queue))
2842                 return;
2843         /* We allways begin with the first requests on the queue, as some
2844          * of previously started requests have to be enqueued on a
2845          * dasd_device again for error recovery.
2846          */
2847         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2848                 if (cqr->status != DASD_CQR_FILLED)
2849                         continue;
2850                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2851                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2852                         cqr->status = DASD_CQR_FAILED;
2853                         cqr->intrc = -EPERM;
2854                         dasd_schedule_block_bh(block);
2855                         continue;
2856                 }
2857                 /* Non-temporary stop condition will trigger fail fast */
2858                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2859                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2860                     (!dasd_eer_enabled(block->base))) {
2861                         cqr->status = DASD_CQR_FAILED;
2862                         cqr->intrc = -ENOLINK;
2863                         dasd_schedule_block_bh(block);
2864                         continue;
2865                 }
2866                 /* Don't try to start requests if device is stopped */
2867                 if (block->base->stopped)
2868                         return;
2869
2870                 /* just a fail safe check, should not happen */
2871                 if (!cqr->startdev)
2872                         cqr->startdev = block->base;
2873
2874                 /* make sure that the requests we submit find their way back */
2875                 cqr->callback = dasd_return_cqr_cb;
2876
2877                 dasd_add_request_tail(cqr);
2878         }
2879 }
2880
2881 /*
2882  * Central dasd_block layer routine. Takes requests from the generic
2883  * block layer request queue, creates ccw requests, enqueues them on
2884  * a dasd_device and processes ccw requests that have been returned.
2885  */
2886 static void dasd_block_tasklet(struct dasd_block *block)
2887 {
2888         struct list_head final_queue;
2889         struct list_head *l, *n;
2890         struct dasd_ccw_req *cqr;
2891
2892         atomic_set(&block->tasklet_scheduled, 0);
2893         INIT_LIST_HEAD(&final_queue);
2894         spin_lock(&block->queue_lock);
2895         /* Finish off requests on ccw queue */
2896         __dasd_process_block_ccw_queue(block, &final_queue);
2897         spin_unlock(&block->queue_lock);
2898         /* Now call the callback function of requests with final status */
2899         spin_lock_irq(&block->request_queue_lock);
2900         list_for_each_safe(l, n, &final_queue) {
2901                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2902                 list_del_init(&cqr->blocklist);
2903                 __dasd_cleanup_cqr(cqr);
2904         }
2905         spin_lock(&block->queue_lock);
2906         /* Get new request from the block device request queue */
2907         __dasd_process_request_queue(block);
2908         /* Now check if the head of the ccw queue needs to be started. */
2909         __dasd_block_start_head(block);
2910         spin_unlock(&block->queue_lock);
2911         spin_unlock_irq(&block->request_queue_lock);
2912         if (waitqueue_active(&shutdown_waitq))
2913                 wake_up(&shutdown_waitq);
2914         dasd_put_device(block->base);
2915 }
2916
2917 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2918 {
2919         wake_up(&dasd_flush_wq);
2920 }
2921
2922 /*
2923  * Requeue a request back to the block request queue
2924  * only works for block requests
2925  */
2926 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2927 {
2928         struct dasd_block *block = cqr->block;
2929         struct request *req;
2930         unsigned long flags;
2931
2932         if (!block)
2933                 return -EINVAL;
2934         spin_lock_irqsave(&block->queue_lock, flags);
2935         req = (struct request *) cqr->callback_data;
2936         blk_requeue_request(block->request_queue, req);
2937         spin_unlock_irqrestore(&block->queue_lock, flags);
2938
2939         return 0;
2940 }
2941
2942 /*
2943  * Go through all request on the dasd_block request queue, cancel them
2944  * on the respective dasd_device, and return them to the generic
2945  * block layer.
2946  */
2947 static int dasd_flush_block_queue(struct dasd_block *block)
2948 {
2949         struct dasd_ccw_req *cqr, *n;
2950         int rc, i;
2951         struct list_head flush_queue;
2952
2953         INIT_LIST_HEAD(&flush_queue);
2954         spin_lock_bh(&block->queue_lock);
2955         rc = 0;
2956 restart:
2957         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2958                 /* if this request currently owned by a dasd_device cancel it */
2959                 if (cqr->status >= DASD_CQR_QUEUED)
2960                         rc = dasd_cancel_req(cqr);
2961                 if (rc < 0)
2962                         break;
2963                 /* Rechain request (including erp chain) so it won't be
2964                  * touched by the dasd_block_tasklet anymore.
2965                  * Replace the callback so we notice when the request
2966                  * is returned from the dasd_device layer.
2967                  */
2968                 cqr->callback = _dasd_wake_block_flush_cb;
2969                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2970                         list_move_tail(&cqr->blocklist, &flush_queue);
2971                 if (i > 1)
2972                         /* moved more than one request - need to restart */
2973                         goto restart;
2974         }
2975         spin_unlock_bh(&block->queue_lock);
2976         /* Now call the callback function of flushed requests */
2977 restart_cb:
2978         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2979                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2980                 /* Process finished ERP request. */
2981                 if (cqr->refers) {
2982                         spin_lock_bh(&block->queue_lock);
2983                         __dasd_process_erp(block->base, cqr);
2984                         spin_unlock_bh(&block->queue_lock);
2985                         /* restart list_for_xx loop since dasd_process_erp
2986                          * might remove multiple elements */
2987                         goto restart_cb;
2988                 }
2989                 /* call the callback function */
2990                 spin_lock_irq(&block->request_queue_lock);
2991                 cqr->endclk = get_tod_clock();
2992                 list_del_init(&cqr->blocklist);
2993                 __dasd_cleanup_cqr(cqr);
2994                 spin_unlock_irq(&block->request_queue_lock);
2995         }
2996         return rc;
2997 }
2998
2999 /*
3000  * Schedules a call to dasd_tasklet over the device tasklet.
3001  */
3002 void dasd_schedule_block_bh(struct dasd_block *block)
3003 {
3004         /* Protect against rescheduling. */
3005         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3006                 return;
3007         /* life cycle of block is bound to it's base device */
3008         dasd_get_device(block->base);
3009         tasklet_hi_schedule(&block->tasklet);
3010 }
3011 EXPORT_SYMBOL(dasd_schedule_block_bh);
3012
3013
3014 /*
3015  * SECTION: external block device operations
3016  * (request queue handling, open, release, etc.)
3017  */
3018
3019 /*
3020  * Dasd request queue function. Called from ll_rw_blk.c
3021  */
3022 static void do_dasd_request(struct request_queue *queue)
3023 {
3024         struct dasd_block *block;
3025
3026         block = queue->queuedata;
3027         spin_lock(&block->queue_lock);
3028         /* Get new request from the block device request queue */
3029         __dasd_process_request_queue(block);
3030         /* Now check if the head of the ccw queue needs to be started. */
3031         __dasd_block_start_head(block);
3032         spin_unlock(&block->queue_lock);
3033 }
3034
3035 /*
3036  * Block timeout callback, called from the block layer
3037  *
3038  * request_queue lock is held on entry.
3039  *
3040  * Return values:
3041  * BLK_EH_RESET_TIMER if the request should be left running
3042  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3043  *                    by the driver.
3044  */
3045 enum blk_eh_timer_return dasd_times_out(struct request *req)
3046 {
3047         struct dasd_ccw_req *cqr = req->completion_data;
3048         struct dasd_block *block = req->q->queuedata;
3049         struct dasd_device *device;
3050         int rc = 0;
3051
3052         if (!cqr)
3053                 return BLK_EH_NOT_HANDLED;
3054
3055         device = cqr->startdev ? cqr->startdev : block->base;
3056         if (!device->blk_timeout)
3057                 return BLK_EH_RESET_TIMER;
3058         DBF_DEV_EVENT(DBF_WARNING, device,
3059                       " dasd_times_out cqr %p status %x",
3060                       cqr, cqr->status);
3061
3062         spin_lock(&block->queue_lock);
3063         spin_lock(get_ccwdev_lock(device->cdev));
3064         cqr->retries = -1;
3065         cqr->intrc = -ETIMEDOUT;
3066         if (cqr->status >= DASD_CQR_QUEUED) {
3067                 spin_unlock(get_ccwdev_lock(device->cdev));
3068                 rc = dasd_cancel_req(cqr);
3069         } else if (cqr->status == DASD_CQR_FILLED ||
3070                    cqr->status == DASD_CQR_NEED_ERP) {
3071                 cqr->status = DASD_CQR_TERMINATED;
3072                 spin_unlock(get_ccwdev_lock(device->cdev));
3073         } else if (cqr->status == DASD_CQR_IN_ERP) {
3074                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3075
3076                 list_for_each_entry_safe(searchcqr, nextcqr,
3077                                          &block->ccw_queue, blocklist) {
3078                         tmpcqr = searchcqr;
3079                         while (tmpcqr->refers)
3080                                 tmpcqr = tmpcqr->refers;
3081                         if (tmpcqr != cqr)
3082                                 continue;
3083                         /* searchcqr is an ERP request for cqr */
3084                         searchcqr->retries = -1;
3085                         searchcqr->intrc = -ETIMEDOUT;
3086                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3087                                 spin_unlock(get_ccwdev_lock(device->cdev));
3088                                 rc = dasd_cancel_req(searchcqr);
3089                                 spin_lock(get_ccwdev_lock(device->cdev));
3090                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3091                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3092                                 searchcqr->status = DASD_CQR_TERMINATED;
3093                                 rc = 0;
3094                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3095                                 /*
3096                                  * Shouldn't happen; most recent ERP
3097                                  * request is at the front of queue
3098                                  */
3099                                 continue;
3100                         }
3101                         break;
3102                 }
3103                 spin_unlock(get_ccwdev_lock(device->cdev));
3104         }
3105         dasd_schedule_block_bh(block);
3106         spin_unlock(&block->queue_lock);
3107
3108         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3109 }
3110
3111 /*
3112  * Allocate and initialize request queue and default I/O scheduler.
3113  */
3114 static int dasd_alloc_queue(struct dasd_block *block)
3115 {
3116         block->request_queue = blk_init_queue(do_dasd_request,
3117                                                &block->request_queue_lock);
3118         if (block->request_queue == NULL)
3119                 return -ENOMEM;
3120
3121         block->request_queue->queuedata = block;
3122
3123         return 0;
3124 }
3125
3126 /*
3127  * Allocate and initialize request queue.
3128  */
3129 static void dasd_setup_queue(struct dasd_block *block)
3130 {
3131         int max;
3132
3133         if (block->base->features & DASD_FEATURE_USERAW) {
3134                 /*
3135                  * the max_blocks value for raw_track access is 256
3136                  * it is higher than the native ECKD value because we
3137                  * only need one ccw per track
3138                  * so the max_hw_sectors are
3139                  * 2048 x 512B = 1024kB = 16 tracks
3140                  */
3141                 max = 2048;
3142         } else {
3143                 max = block->base->discipline->max_blocks << block->s2b_shift;
3144         }
3145         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue);
3146         block->request_queue->limits.max_dev_sectors = max;
3147         blk_queue_logical_block_size(block->request_queue,
3148                                      block->bp_block);
3149         blk_queue_max_hw_sectors(block->request_queue, max);
3150         blk_queue_max_segments(block->request_queue, -1L);
3151         /* with page sized segments we can translate each segement into
3152          * one idaw/tidaw
3153          */
3154         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
3155         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
3156 }
3157
3158 /*
3159  * Deactivate and free request queue.
3160  */
3161 static void dasd_free_queue(struct dasd_block *block)
3162 {
3163         if (block->request_queue) {
3164                 blk_cleanup_queue(block->request_queue);
3165                 block->request_queue = NULL;
3166         }
3167 }
3168
3169 /*
3170  * Flush request on the request queue.
3171  */
3172 static void dasd_flush_request_queue(struct dasd_block *block)
3173 {
3174         struct request *req;
3175
3176         if (!block->request_queue)
3177                 return;
3178
3179         spin_lock_irq(&block->request_queue_lock);
3180         while ((req = blk_fetch_request(block->request_queue)))
3181                 __blk_end_request_all(req, -EIO);
3182         spin_unlock_irq(&block->request_queue_lock);
3183 }
3184
3185 static int dasd_open(struct block_device *bdev, fmode_t mode)
3186 {
3187         struct dasd_device *base;
3188         int rc;
3189
3190         base = dasd_device_from_gendisk(bdev->bd_disk);
3191         if (!base)
3192                 return -ENODEV;
3193
3194         atomic_inc(&base->block->open_count);
3195         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3196                 rc = -ENODEV;
3197                 goto unlock;
3198         }
3199
3200         if (!try_module_get(base->discipline->owner)) {
3201                 rc = -EINVAL;
3202                 goto unlock;
3203         }
3204
3205         if (dasd_probeonly) {
3206                 dev_info(&base->cdev->dev,
3207                          "Accessing the DASD failed because it is in "
3208                          "probeonly mode\n");
3209                 rc = -EPERM;
3210                 goto out;
3211         }
3212
3213         if (base->state <= DASD_STATE_BASIC) {
3214                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3215                               " Cannot open unrecognized device");
3216                 rc = -ENODEV;
3217                 goto out;
3218         }
3219
3220         if ((mode & FMODE_WRITE) &&
3221             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3222              (base->features & DASD_FEATURE_READONLY))) {
3223                 rc = -EROFS;
3224                 goto out;
3225         }
3226
3227         dasd_put_device(base);
3228         return 0;
3229
3230 out:
3231         module_put(base->discipline->owner);
3232 unlock:
3233         atomic_dec(&base->block->open_count);
3234         dasd_put_device(base);
3235         return rc;
3236 }
3237
3238 static void dasd_release(struct gendisk *disk, fmode_t mode)
3239 {
3240         struct dasd_device *base = dasd_device_from_gendisk(disk);
3241         if (base) {
3242                 atomic_dec(&base->block->open_count);
3243                 module_put(base->discipline->owner);
3244                 dasd_put_device(base);
3245         }
3246 }
3247
3248 /*
3249  * Return disk geometry.
3250  */
3251 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3252 {
3253         struct dasd_device *base;
3254
3255         base = dasd_device_from_gendisk(bdev->bd_disk);
3256         if (!base)
3257                 return -ENODEV;
3258
3259         if (!base->discipline ||
3260             !base->discipline->fill_geometry) {
3261                 dasd_put_device(base);
3262                 return -EINVAL;
3263         }
3264         base->discipline->fill_geometry(base->block, geo);
3265         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3266         dasd_put_device(base);
3267         return 0;
3268 }
3269
3270 const struct block_device_operations
3271 dasd_device_operations = {
3272         .owner          = THIS_MODULE,
3273         .open           = dasd_open,
3274         .release        = dasd_release,
3275         .ioctl          = dasd_ioctl,
3276         .compat_ioctl   = dasd_ioctl,
3277         .getgeo         = dasd_getgeo,
3278 };
3279
3280 /*******************************************************************************
3281  * end of block device operations
3282  */
3283
3284 static void
3285 dasd_exit(void)
3286 {
3287 #ifdef CONFIG_PROC_FS
3288         dasd_proc_exit();
3289 #endif
3290         dasd_eer_exit();
3291         if (dasd_page_cache != NULL) {
3292                 kmem_cache_destroy(dasd_page_cache);
3293                 dasd_page_cache = NULL;
3294         }
3295         dasd_gendisk_exit();
3296         dasd_devmap_exit();
3297         if (dasd_debug_area != NULL) {
3298                 debug_unregister(dasd_debug_area);
3299                 dasd_debug_area = NULL;
3300         }
3301         dasd_statistics_removeroot();
3302 }
3303
3304 /*
3305  * SECTION: common functions for ccw_driver use
3306  */
3307
3308 /*
3309  * Is the device read-only?
3310  * Note that this function does not report the setting of the
3311  * readonly device attribute, but how it is configured in z/VM.
3312  */
3313 int dasd_device_is_ro(struct dasd_device *device)
3314 {
3315         struct ccw_dev_id dev_id;
3316         struct diag210 diag_data;
3317         int rc;
3318
3319         if (!MACHINE_IS_VM)
3320                 return 0;
3321         ccw_device_get_id(device->cdev, &dev_id);
3322         memset(&diag_data, 0, sizeof(diag_data));
3323         diag_data.vrdcdvno = dev_id.devno;
3324         diag_data.vrdclen = sizeof(diag_data);
3325         rc = diag210(&diag_data);
3326         if (rc == 0 || rc == 2) {
3327                 return diag_data.vrdcvfla & 0x80;
3328         } else {
3329                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3330                           dev_id.devno, rc);
3331                 return 0;
3332         }
3333 }
3334 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3335
3336 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3337 {
3338         struct ccw_device *cdev = data;
3339         int ret;
3340
3341         ret = ccw_device_set_online(cdev);
3342         if (ret)
3343                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3344                         dev_name(&cdev->dev), ret);
3345 }
3346
3347 /*
3348  * Initial attempt at a probe function. this can be simplified once
3349  * the other detection code is gone.
3350  */
3351 int dasd_generic_probe(struct ccw_device *cdev,
3352                        struct dasd_discipline *discipline)
3353 {
3354         int ret;
3355
3356         ret = dasd_add_sysfs_files(cdev);
3357         if (ret) {
3358                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3359                                 "dasd_generic_probe: could not add "
3360                                 "sysfs entries");
3361                 return ret;
3362         }
3363         cdev->handler = &dasd_int_handler;
3364
3365         /*
3366          * Automatically online either all dasd devices (dasd_autodetect)
3367          * or all devices specified with dasd= parameters during
3368          * initial probe.
3369          */
3370         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3371             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3372                 async_schedule(dasd_generic_auto_online, cdev);
3373         return 0;
3374 }
3375 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3376
3377 void dasd_generic_free_discipline(struct dasd_device *device)
3378 {
3379         /* Forget the discipline information. */
3380         if (device->discipline) {
3381                 if (device->discipline->uncheck_device)
3382                         device->discipline->uncheck_device(device);
3383                 module_put(device->discipline->owner);
3384                 device->discipline = NULL;
3385         }
3386         if (device->base_discipline) {
3387                 module_put(device->base_discipline->owner);
3388                 device->base_discipline = NULL;
3389         }
3390 }
3391 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3392
3393 /*
3394  * This will one day be called from a global not_oper handler.
3395  * It is also used by driver_unregister during module unload.
3396  */
3397 void dasd_generic_remove(struct ccw_device *cdev)
3398 {
3399         struct dasd_device *device;
3400         struct dasd_block *block;
3401
3402         device = dasd_device_from_cdev(cdev);
3403         if (IS_ERR(device)) {
3404                 dasd_remove_sysfs_files(cdev);
3405                 return;
3406         }
3407         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3408             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3409                 /* Already doing offline processing */
3410                 dasd_put_device(device);
3411                 dasd_remove_sysfs_files(cdev);
3412                 return;
3413         }
3414         /*
3415          * This device is removed unconditionally. Set offline
3416          * flag to prevent dasd_open from opening it while it is
3417          * no quite down yet.
3418          */
3419         dasd_set_target_state(device, DASD_STATE_NEW);
3420         cdev->handler = NULL;
3421         /* dasd_delete_device destroys the device reference. */
3422         block = device->block;
3423         dasd_delete_device(device);
3424         /*
3425          * life cycle of block is bound to device, so delete it after
3426          * device was safely removed
3427          */
3428         if (block)
3429                 dasd_free_block(block);
3430
3431         dasd_remove_sysfs_files(cdev);
3432 }
3433 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3434
3435 /*
3436  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3437  * the device is detected for the first time and is supposed to be used
3438  * or the user has started activation through sysfs.
3439  */
3440 int dasd_generic_set_online(struct ccw_device *cdev,
3441                             struct dasd_discipline *base_discipline)
3442 {
3443         struct dasd_discipline *discipline;
3444         struct dasd_device *device;
3445         int rc;
3446
3447         /* first online clears initial online feature flag */
3448         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3449         device = dasd_create_device(cdev);
3450         if (IS_ERR(device))
3451                 return PTR_ERR(device);
3452
3453         discipline = base_discipline;
3454         if (device->features & DASD_FEATURE_USEDIAG) {
3455                 if (!dasd_diag_discipline_pointer) {
3456                         /* Try to load the required module. */
3457                         rc = request_module(DASD_DIAG_MOD);
3458                         if (rc) {
3459                                 pr_warn("%s Setting the DASD online failed "
3460                                         "because the required module %s "
3461                                         "could not be loaded (rc=%d)\n",
3462                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3463                                         rc);
3464                                 dasd_delete_device(device);
3465                                 return -ENODEV;
3466                         }
3467                 }
3468                 /* Module init could have failed, so check again here after
3469                  * request_module(). */
3470                 if (!dasd_diag_discipline_pointer) {
3471                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3472                                 dev_name(&cdev->dev));
3473                         dasd_delete_device(device);
3474                         return -ENODEV;
3475                 }
3476                 discipline = dasd_diag_discipline_pointer;
3477         }
3478         if (!try_module_get(base_discipline->owner)) {
3479                 dasd_delete_device(device);
3480                 return -EINVAL;
3481         }
3482         if (!try_module_get(discipline->owner)) {
3483                 module_put(base_discipline->owner);
3484                 dasd_delete_device(device);
3485                 return -EINVAL;
3486         }
3487         device->base_discipline = base_discipline;
3488         device->discipline = discipline;
3489
3490         /* check_device will allocate block device if necessary */
3491         rc = discipline->check_device(device);
3492         if (rc) {
3493                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3494                         dev_name(&cdev->dev), discipline->name, rc);
3495                 module_put(discipline->owner);
3496                 module_put(base_discipline->owner);
3497                 dasd_delete_device(device);
3498                 return rc;
3499         }
3500
3501         dasd_set_target_state(device, DASD_STATE_ONLINE);
3502         if (device->state <= DASD_STATE_KNOWN) {
3503                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3504                         dev_name(&cdev->dev));
3505                 rc = -ENODEV;
3506                 dasd_set_target_state(device, DASD_STATE_NEW);
3507                 if (device->block)
3508                         dasd_free_block(device->block);
3509                 dasd_delete_device(device);
3510         } else
3511                 pr_debug("dasd_generic device %s found\n",
3512                                 dev_name(&cdev->dev));
3513
3514         wait_event(dasd_init_waitq, _wait_for_device(device));
3515
3516         dasd_put_device(device);
3517         return rc;
3518 }
3519 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3520
3521 int dasd_generic_set_offline(struct ccw_device *cdev)
3522 {
3523         struct dasd_device *device;
3524         struct dasd_block *block;
3525         int max_count, open_count, rc;
3526
3527         rc = 0;
3528         device = dasd_device_from_cdev(cdev);
3529         if (IS_ERR(device))
3530                 return PTR_ERR(device);
3531
3532         /*
3533          * We must make sure that this device is currently not in use.
3534          * The open_count is increased for every opener, that includes
3535          * the blkdev_get in dasd_scan_partitions. We are only interested
3536          * in the other openers.
3537          */
3538         if (device->block) {
3539                 max_count = device->block->bdev ? 0 : -1;
3540                 open_count = atomic_read(&device->block->open_count);
3541                 if (open_count > max_count) {
3542                         if (open_count > 0)
3543                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3544                                         dev_name(&cdev->dev), open_count);
3545                         else
3546                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3547                                         dev_name(&cdev->dev));
3548                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3549                         dasd_put_device(device);
3550                         return -EBUSY;
3551                 }
3552         }
3553
3554         if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3555                 /*
3556                  * safe offline already running
3557                  * could only be called by normal offline so safe_offline flag
3558                  * needs to be removed to run normal offline and kill all I/O
3559                  */
3560                 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3561                         /* Already doing normal offline processing */
3562                         dasd_put_device(device);
3563                         return -EBUSY;
3564                 } else
3565                         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3566
3567         } else
3568                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3569                         /* Already doing offline processing */
3570                         dasd_put_device(device);
3571                         return -EBUSY;
3572                 }
3573
3574         /*
3575          * if safe_offline called set safe_offline_running flag and
3576          * clear safe_offline so that a call to normal offline
3577          * can overrun safe_offline processing
3578          */
3579         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3580             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3581                 /*
3582                  * If we want to set the device safe offline all IO operations
3583                  * should be finished before continuing the offline process
3584                  * so sync bdev first and then wait for our queues to become
3585                  * empty
3586                  */
3587                 /* sync blockdev and partitions */
3588                 rc = fsync_bdev(device->block->bdev);
3589                 if (rc != 0)
3590                         goto interrupted;
3591
3592                 /* schedule device tasklet and wait for completion */
3593                 dasd_schedule_device_bh(device);
3594                 rc = wait_event_interruptible(shutdown_waitq,
3595                                               _wait_for_empty_queues(device));
3596                 if (rc != 0)
3597                         goto interrupted;
3598         }
3599
3600         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3601         dasd_set_target_state(device, DASD_STATE_NEW);
3602         /* dasd_delete_device destroys the device reference. */
3603         block = device->block;
3604         dasd_delete_device(device);
3605         /*
3606          * life cycle of block is bound to device, so delete it after
3607          * device was safely removed
3608          */
3609         if (block)
3610                 dasd_free_block(block);
3611         return 0;
3612
3613 interrupted:
3614         /* interrupted by signal */
3615         clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
3616         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3617         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3618         dasd_put_device(device);
3619         return rc;
3620 }
3621 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3622
3623 int dasd_generic_last_path_gone(struct dasd_device *device)
3624 {
3625         struct dasd_ccw_req *cqr;
3626
3627         dev_warn(&device->cdev->dev, "No operational channel path is left "
3628                  "for the device\n");
3629         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3630         /* First of all call extended error reporting. */
3631         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3632
3633         if (device->state < DASD_STATE_BASIC)
3634                 return 0;
3635         /* Device is active. We want to keep it. */
3636         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3637                 if ((cqr->status == DASD_CQR_IN_IO) ||
3638                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3639                         cqr->status = DASD_CQR_QUEUED;
3640                         cqr->retries++;
3641                 }
3642         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3643         dasd_device_clear_timer(device);
3644         dasd_schedule_device_bh(device);
3645         return 1;
3646 }
3647 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3648
3649 int dasd_generic_path_operational(struct dasd_device *device)
3650 {
3651         dev_info(&device->cdev->dev, "A channel path to the device has become "
3652                  "operational\n");
3653         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3654         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3655         if (device->stopped & DASD_UNRESUMED_PM) {
3656                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3657                 dasd_restore_device(device);
3658                 return 1;
3659         }
3660         dasd_schedule_device_bh(device);
3661         if (device->block)
3662                 dasd_schedule_block_bh(device->block);
3663
3664         if (!device->stopped)
3665                 wake_up(&generic_waitq);
3666
3667         return 1;
3668 }
3669 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3670
3671 int dasd_generic_notify(struct ccw_device *cdev, int event)
3672 {
3673         struct dasd_device *device;
3674         int ret;
3675
3676         device = dasd_device_from_cdev_locked(cdev);
3677         if (IS_ERR(device))
3678                 return 0;
3679         ret = 0;
3680         switch (event) {
3681         case CIO_GONE:
3682         case CIO_BOXED:
3683         case CIO_NO_PATH:
3684                 device->path_data.opm = 0;
3685                 device->path_data.ppm = 0;
3686                 device->path_data.npm = 0;
3687                 ret = dasd_generic_last_path_gone(device);
3688                 break;
3689         case CIO_OPER:
3690                 ret = 1;
3691                 if (device->path_data.opm)
3692                         ret = dasd_generic_path_operational(device);
3693                 break;
3694         }
3695         dasd_put_device(device);
3696         return ret;
3697 }
3698 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3699
3700 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3701 {
3702         int chp;
3703         __u8 oldopm, eventlpm;
3704         struct dasd_device *device;
3705
3706         device = dasd_device_from_cdev_locked(cdev);
3707         if (IS_ERR(device))
3708                 return;
3709         for (chp = 0; chp < 8; chp++) {
3710                 eventlpm = 0x80 >> chp;
3711                 if (path_event[chp] & PE_PATH_GONE) {
3712                         oldopm = device->path_data.opm;
3713                         device->path_data.opm &= ~eventlpm;
3714                         device->path_data.ppm &= ~eventlpm;
3715                         device->path_data.npm &= ~eventlpm;
3716                         if (oldopm && !device->path_data.opm) {
3717                                 dev_warn(&device->cdev->dev,
3718                                          "No verified channel paths remain "
3719                                          "for the device\n");
3720                                 DBF_DEV_EVENT(DBF_WARNING, device,
3721                                               "%s", "last verified path gone");
3722                                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3723                                 dasd_device_set_stop_bits(device,
3724                                                           DASD_STOPPED_DC_WAIT);
3725                         }
3726                 }
3727                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3728                         device->path_data.opm &= ~eventlpm;
3729                         device->path_data.ppm &= ~eventlpm;
3730                         device->path_data.npm &= ~eventlpm;
3731                         device->path_data.tbvpm |= eventlpm;
3732                         dasd_schedule_device_bh(device);
3733                 }
3734                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3735                         if (!(device->path_data.opm & eventlpm) &&
3736                             !(device->path_data.tbvpm & eventlpm)) {
3737                                 /*
3738                                  * we can not establish a pathgroup on an
3739                                  * unavailable path, so trigger a path
3740                                  * verification first
3741                                  */
3742                                 device->path_data.tbvpm |= eventlpm;
3743                                 dasd_schedule_device_bh(device);
3744                         }
3745                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3746                                       "Pathgroup re-established\n");
3747                         if (device->discipline->kick_validate)
3748                                 device->discipline->kick_validate(device);
3749                 }
3750         }
3751         dasd_put_device(device);
3752 }
3753 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3754
3755 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3756 {
3757         if (!device->path_data.opm && lpm) {
3758                 device->path_data.opm = lpm;
3759                 dasd_generic_path_operational(device);
3760         } else
3761                 device->path_data.opm |= lpm;
3762         return 0;
3763 }
3764 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3765
3766
3767 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3768 {
3769         struct dasd_device *device = dasd_device_from_cdev(cdev);
3770         struct list_head freeze_queue;
3771         struct dasd_ccw_req *cqr, *n;
3772         struct dasd_ccw_req *refers;
3773         int rc;
3774
3775         if (IS_ERR(device))
3776                 return PTR_ERR(device);
3777
3778         /* mark device as suspended */
3779         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3780
3781         if (device->discipline->freeze)
3782                 rc = device->discipline->freeze(device);
3783
3784         /* disallow new I/O  */
3785         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3786
3787         /* clear active requests and requeue them to block layer if possible */
3788         INIT_LIST_HEAD(&freeze_queue);
3789         spin_lock_irq(get_ccwdev_lock(cdev));
3790         rc = 0;
3791         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3792                 /* Check status and move request to flush_queue */
3793                 if (cqr->status == DASD_CQR_IN_IO) {
3794                         rc = device->discipline->term_IO(cqr);
3795                         if (rc) {
3796                                 /* unable to terminate requeust */
3797                                 dev_err(&device->cdev->dev,
3798                                         "Unable to terminate request %p "
3799                                         "on suspend\n", cqr);
3800                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3801                                 dasd_put_device(device);
3802                                 return rc;
3803                         }
3804                 }
3805                 list_move_tail(&cqr->devlist, &freeze_queue);
3806         }
3807         spin_unlock_irq(get_ccwdev_lock(cdev));
3808
3809         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3810                 wait_event(dasd_flush_wq,
3811                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3812                 if (cqr->status == DASD_CQR_CLEARED)
3813                         cqr->status = DASD_CQR_QUEUED;
3814
3815                 /* requeue requests to blocklayer will only work for
3816                    block device requests */
3817                 if (_dasd_requeue_request(cqr))
3818                         continue;
3819
3820                 /* remove requests from device and block queue */
3821                 list_del_init(&cqr->devlist);
3822                 while (cqr->refers != NULL) {
3823                         refers = cqr->refers;
3824                         /* remove the request from the block queue */
3825                         list_del(&cqr->blocklist);
3826                         /* free the finished erp request */
3827                         dasd_free_erp_request(cqr, cqr->memdev);
3828                         cqr = refers;
3829                 }
3830                 if (cqr->block)
3831                         list_del_init(&cqr->blocklist);
3832                 cqr->block->base->discipline->free_cp(
3833                         cqr, (struct request *) cqr->callback_data);
3834         }
3835
3836         /*
3837          * if requests remain then they are internal request
3838          * and go back to the device queue
3839          */
3840         if (!list_empty(&freeze_queue)) {
3841                 /* move freeze_queue to start of the ccw_queue */
3842                 spin_lock_irq(get_ccwdev_lock(cdev));
3843                 list_splice_tail(&freeze_queue, &device->ccw_queue);
3844                 spin_unlock_irq(get_ccwdev_lock(cdev));
3845         }
3846         dasd_put_device(device);
3847         return rc;
3848 }
3849 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3850
3851 int dasd_generic_restore_device(struct ccw_device *cdev)
3852 {
3853         struct dasd_device *device = dasd_device_from_cdev(cdev);
3854         int rc = 0;
3855
3856         if (IS_ERR(device))
3857                 return PTR_ERR(device);
3858
3859         /* allow new IO again */
3860         dasd_device_remove_stop_bits(device,
3861                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3862
3863         dasd_schedule_device_bh(device);
3864
3865         /*
3866          * call discipline restore function
3867          * if device is stopped do nothing e.g. for disconnected devices
3868          */
3869         if (device->discipline->restore && !(device->stopped))
3870                 rc = device->discipline->restore(device);
3871         if (rc || device->stopped)
3872                 /*
3873                  * if the resume failed for the DASD we put it in
3874                  * an UNRESUMED stop state
3875                  */
3876                 device->stopped |= DASD_UNRESUMED_PM;
3877
3878         if (device->block)
3879                 dasd_schedule_block_bh(device->block);
3880
3881         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3882         dasd_put_device(device);
3883         return 0;
3884 }
3885 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3886
3887 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3888                                                    void *rdc_buffer,
3889                                                    int rdc_buffer_size,
3890                                                    int magic)
3891 {
3892         struct dasd_ccw_req *cqr;
3893         struct ccw1 *ccw;
3894         unsigned long *idaw;
3895
3896         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3897
3898         if (IS_ERR(cqr)) {
3899                 /* internal error 13 - Allocating the RDC request failed*/
3900                 dev_err(&device->cdev->dev,
3901                          "An error occurred in the DASD device driver, "
3902                          "reason=%s\n", "13");
3903                 return cqr;
3904         }
3905
3906         ccw = cqr->cpaddr;
3907         ccw->cmd_code = CCW_CMD_RDC;
3908         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3909                 idaw = (unsigned long *) (cqr->data);
3910                 ccw->cda = (__u32)(addr_t) idaw;
3911                 ccw->flags = CCW_FLAG_IDA;
3912                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3913         } else {
3914                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3915                 ccw->flags = 0;
3916         }
3917
3918         ccw->count = rdc_buffer_size;
3919         cqr->startdev = device;
3920         cqr->memdev = device;
3921         cqr->expires = 10*HZ;
3922         cqr->retries = 256;
3923         cqr->buildclk = get_tod_clock();
3924         cqr->status = DASD_CQR_FILLED;
3925         return cqr;
3926 }
3927
3928
3929 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3930                                 void *rdc_buffer, int rdc_buffer_size)
3931 {
3932         int ret;
3933         struct dasd_ccw_req *cqr;
3934
3935         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3936                                      magic);
3937         if (IS_ERR(cqr))
3938                 return PTR_ERR(cqr);
3939
3940         ret = dasd_sleep_on(cqr);
3941         dasd_sfree_request(cqr, cqr->memdev);
3942         return ret;
3943 }
3944 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3945
3946 /*
3947  *   In command mode and transport mode we need to look for sense
3948  *   data in different places. The sense data itself is allways
3949  *   an array of 32 bytes, so we can unify the sense data access
3950  *   for both modes.
3951  */
3952 char *dasd_get_sense(struct irb *irb)
3953 {
3954         struct tsb *tsb = NULL;
3955         char *sense = NULL;
3956
3957         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3958                 if (irb->scsw.tm.tcw)
3959                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3960                                           irb->scsw.tm.tcw);
3961                 if (tsb && tsb->length == 64 && tsb->flags)
3962                         switch (tsb->flags & 0x07) {
3963                         case 1: /* tsa_iostat */
3964                                 sense = tsb->tsa.iostat.sense;
3965                                 break;
3966                         case 2: /* tsa_ddpc */
3967                                 sense = tsb->tsa.ddpc.sense;
3968                                 break;
3969                         default:
3970                                 /* currently we don't use interrogate data */
3971                                 break;
3972                         }
3973         } else if (irb->esw.esw0.erw.cons) {
3974                 sense = irb->ecw;
3975         }
3976         return sense;
3977 }
3978 EXPORT_SYMBOL_GPL(dasd_get_sense);
3979
3980 void dasd_generic_shutdown(struct ccw_device *cdev)
3981 {
3982         struct dasd_device *device;
3983
3984         device = dasd_device_from_cdev(cdev);
3985         if (IS_ERR(device))
3986                 return;
3987
3988         if (device->block)
3989                 dasd_schedule_block_bh(device->block);
3990
3991         dasd_schedule_device_bh(device);
3992
3993         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
3994 }
3995 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
3996
3997 static int __init dasd_init(void)
3998 {
3999         int rc;
4000
4001         init_waitqueue_head(&dasd_init_waitq);
4002         init_waitqueue_head(&dasd_flush_wq);
4003         init_waitqueue_head(&generic_waitq);
4004         init_waitqueue_head(&shutdown_waitq);
4005
4006         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4007         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4008         if (dasd_debug_area == NULL) {
4009                 rc = -ENOMEM;
4010                 goto failed;
4011         }
4012         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4013         debug_set_level(dasd_debug_area, DBF_WARNING);
4014
4015         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4016
4017         dasd_diag_discipline_pointer = NULL;
4018
4019         dasd_statistics_createroot();
4020
4021         rc = dasd_devmap_init();
4022         if (rc)
4023                 goto failed;
4024         rc = dasd_gendisk_init();
4025         if (rc)
4026                 goto failed;
4027         rc = dasd_parse();
4028         if (rc)
4029                 goto failed;
4030         rc = dasd_eer_init();
4031         if (rc)
4032                 goto failed;
4033 #ifdef CONFIG_PROC_FS
4034         rc = dasd_proc_init();
4035         if (rc)
4036                 goto failed;
4037 #endif
4038
4039         return 0;
4040 failed:
4041         pr_info("The DASD device driver could not be initialized\n");
4042         dasd_exit();
4043         return rc;
4044 }
4045
4046 module_init(dasd_init);
4047 module_exit(dasd_exit);