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