drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_SLEEPON_START_TAG  (void *) 1
  43 #define DASD_SLEEPON_END_TAG    (void *) 2
  44
  45 /*
  46  * SECTION: exported variables of dasd.c
  47  */
  48 debug_info_t *dasd_debug_area;
  49 static struct dentry *dasd_debugfs_root_entry;
  50 struct dasd_discipline *dasd_diag_discipline_pointer;
  51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  52
  53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  55                    " Copyright 2000 IBM Corporation");
  56 MODULE_SUPPORTED_DEVICE("dasd");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int  dasd_alloc_queue(struct dasd_block *);
  63 static void dasd_setup_queue(struct dasd_block *);
  64 static void dasd_free_queue(struct dasd_block *);
  65 static void dasd_flush_request_queue(struct dasd_block *);
  66 static int dasd_flush_block_queue(struct dasd_block *);
  67 static void dasd_device_tasklet(struct dasd_device *);
  68 static void dasd_block_tasklet(struct dasd_block *);
  69 static void do_kick_device(struct work_struct *);
  70 static void do_restore_device(struct work_struct *);
  71 static void do_reload_device(struct work_struct *);
  72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  73 static void dasd_device_timeout(unsigned long);
  74 static void dasd_block_timeout(unsigned long);
  75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  77 static void dasd_profile_exit(struct dasd_profile *);
  78
  79 /*
  80  * SECTION: Operations on the device structure.
  81  */
  82 static wait_queue_head_t dasd_init_waitq;
  83 static wait_queue_head_t dasd_flush_wq;
  84 static wait_queue_head_t generic_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         if (device->state == device->target)
 538                 wake_up(&dasd_init_waitq);
 539
 540         /* let user-space know that the device status changed */
 541         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 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
 645 /*
 646  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 647  */
 648
 649 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 650
 651 #ifdef CONFIG_DASD_PROFILE
 652 struct dasd_profile_info dasd_global_profile_data;
 653 static struct dentry *dasd_global_profile_dentry;
 654 static struct dentry *dasd_debugfs_global_entry;
 655
 656 /*
 657  * Add profiling information for cqr before execution.
 658  */
 659 static void dasd_profile_start(struct dasd_block *block,
 660                                struct dasd_ccw_req *cqr,
 661                                struct request *req)
 662 {
 663         struct list_head *l;
 664         unsigned int counter;
 665         struct dasd_device *device;
 666
 667         /* count the length of the chanq for statistics */
 668         counter = 0;
 669         if (dasd_global_profile_level || block->profile.data)
 670                 list_for_each(l, &block->ccw_queue)
 671                         if (++counter >= 31)
 672                                 break;
 673
 674         if (dasd_global_profile_level) {
 675                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 676                 if (rq_data_dir(req) == READ)
 677                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 678         }
 679
 680         spin_lock(&block->profile.lock);
 681         if (block->profile.data)
 682                 block->profile.data->dasd_io_nr_req[counter]++;
 683                 if (rq_data_dir(req) == READ)
 684                         block->profile.data->dasd_read_nr_req[counter]++;
 685         spin_unlock(&block->profile.lock);
 686
 687         /*
 688          * We count the request for the start device, even though it may run on
 689          * some other device due to error recovery. This way we make sure that
 690          * we count each request only once.
 691          */
 692         device = cqr->startdev;
 693         if (device->profile.data) {
 694                 counter = 1; /* request is not yet queued on the start device */
 695                 list_for_each(l, &device->ccw_queue)
 696                         if (++counter >= 31)
 697                                 break;
 698         }
 699         spin_lock(&device->profile.lock);
 700         if (device->profile.data) {
 701                 device->profile.data->dasd_io_nr_req[counter]++;
 702                 if (rq_data_dir(req) == READ)
 703                         device->profile.data->dasd_read_nr_req[counter]++;
 704         }
 705         spin_unlock(&device->profile.lock);
 706 }
 707
 708 /*
 709  * Add profiling information for cqr after execution.
 710  */
 711
 712 #define dasd_profile_counter(value, index)                         \
 713 {                                                                  \
 714         for (index = 0; index < 31 && value >> (2+index); index++) \
 715                 ;                                                  \
 716 }
 717
 718 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 719                                       int is_alias,
 720                                       int is_tpm,
 721                                       int is_read,
 722                                       long sectors,
 723                                       int sectors_ind,
 724                                       int tottime_ind,
 725                                       int tottimeps_ind,
 726                                       int strtime_ind,
 727                                       int irqtime_ind,
 728                                       int irqtimeps_ind,
 729                                       int endtime_ind)
 730 {
 731         /* in case of an overflow, reset the whole profile */
 732         if (data->dasd_io_reqs == UINT_MAX) {
 733                         memset(data, 0, sizeof(*data));
 734                         getnstimeofday(&data->starttod);
 735         }
 736         data->dasd_io_reqs++;
 737         data->dasd_io_sects += sectors;
 738         if (is_alias)
 739                 data->dasd_io_alias++;
 740         if (is_tpm)
 741                 data->dasd_io_tpm++;
 742
 743         data->dasd_io_secs[sectors_ind]++;
 744         data->dasd_io_times[tottime_ind]++;
 745         data->dasd_io_timps[tottimeps_ind]++;
 746         data->dasd_io_time1[strtime_ind]++;
 747         data->dasd_io_time2[irqtime_ind]++;
 748         data->dasd_io_time2ps[irqtimeps_ind]++;
 749         data->dasd_io_time3[endtime_ind]++;
 750
 751         if (is_read) {
 752                 data->dasd_read_reqs++;
 753                 data->dasd_read_sects += sectors;
 754                 if (is_alias)
 755                         data->dasd_read_alias++;
 756                 if (is_tpm)
 757                         data->dasd_read_tpm++;
 758                 data->dasd_read_secs[sectors_ind]++;
 759                 data->dasd_read_times[tottime_ind]++;
 760                 data->dasd_read_time1[strtime_ind]++;
 761                 data->dasd_read_time2[irqtime_ind]++;
 762                 data->dasd_read_time3[endtime_ind]++;
 763         }
 764 }
 765
 766 static void dasd_profile_end(struct dasd_block *block,
 767                              struct dasd_ccw_req *cqr,
 768                              struct request *req)
 769 {
 770         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 771         long tottimeps, sectors;
 772         struct dasd_device *device;
 773         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 774         int irqtime_ind, irqtimeps_ind, endtime_ind;
 775
 776         device = cqr->startdev;
 777         if (!(dasd_global_profile_level ||
 778               block->profile.data ||
 779               device->profile.data))
 780                 return;
 781
 782         sectors = blk_rq_sectors(req);
 783         if (!cqr->buildclk || !cqr->startclk ||
 784             !cqr->stopclk || !cqr->endclk ||
 785             !sectors)
 786                 return;
 787
 788         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 789         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 790         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 791         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 792         tottimeps = tottime / sectors;
 793
 794         dasd_profile_counter(sectors, sectors_ind);
 795         dasd_profile_counter(tottime, tottime_ind);
 796         dasd_profile_counter(tottimeps, tottimeps_ind);
 797         dasd_profile_counter(strtime, strtime_ind);
 798         dasd_profile_counter(irqtime, irqtime_ind);
 799         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 800         dasd_profile_counter(endtime, endtime_ind);
 801
 802         if (dasd_global_profile_level) {
 803                 dasd_profile_end_add_data(&dasd_global_profile_data,
 804                                           cqr->startdev != block->base,
 805                                           cqr->cpmode == 1,
 806                                           rq_data_dir(req) == READ,
 807                                           sectors, sectors_ind, tottime_ind,
 808                                           tottimeps_ind, strtime_ind,
 809                                           irqtime_ind, irqtimeps_ind,
 810                                           endtime_ind);
 811         }
 812
 813         spin_lock(&block->profile.lock);
 814         if (block->profile.data)
 815                 dasd_profile_end_add_data(block->profile.data,
 816                                           cqr->startdev != block->base,
 817                                           cqr->cpmode == 1,
 818                                           rq_data_dir(req) == READ,
 819                                           sectors, sectors_ind, tottime_ind,
 820                                           tottimeps_ind, strtime_ind,
 821                                           irqtime_ind, irqtimeps_ind,
 822                                           endtime_ind);
 823         spin_unlock(&block->profile.lock);
 824
 825         spin_lock(&device->profile.lock);
 826         if (device->profile.data)
 827                 dasd_profile_end_add_data(device->profile.data,
 828                                           cqr->startdev != block->base,
 829                                           cqr->cpmode == 1,
 830                                           rq_data_dir(req) == READ,
 831                                           sectors, sectors_ind, tottime_ind,
 832                                           tottimeps_ind, strtime_ind,
 833                                           irqtime_ind, irqtimeps_ind,
 834                                           endtime_ind);
 835         spin_unlock(&device->profile.lock);
 836 }
 837
 838 void dasd_profile_reset(struct dasd_profile *profile)
 839 {
 840         struct dasd_profile_info *data;
 841
 842         spin_lock_bh(&profile->lock);
 843         data = profile->data;
 844         if (!data) {
 845                 spin_unlock_bh(&profile->lock);
 846                 return;
 847         }
 848         memset(data, 0, sizeof(*data));
 849         getnstimeofday(&data->starttod);
 850         spin_unlock_bh(&profile->lock);
 851 }
 852
 853 void dasd_global_profile_reset(void)
 854 {
 855         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 856         getnstimeofday(&dasd_global_profile_data.starttod);
 857 }
 858
 859 int dasd_profile_on(struct dasd_profile *profile)
 860 {
 861         struct dasd_profile_info *data;
 862
 863         data = kzalloc(sizeof(*data), GFP_KERNEL);
 864         if (!data)
 865                 return -ENOMEM;
 866         spin_lock_bh(&profile->lock);
 867         if (profile->data) {
 868                 spin_unlock_bh(&profile->lock);
 869                 kfree(data);
 870                 return 0;
 871         }
 872         getnstimeofday(&data->starttod);
 873         profile->data = data;
 874         spin_unlock_bh(&profile->lock);
 875         return 0;
 876 }
 877
 878 void dasd_profile_off(struct dasd_profile *profile)
 879 {
 880         spin_lock_bh(&profile->lock);
 881         kfree(profile->data);
 882         profile->data = NULL;
 883         spin_unlock_bh(&profile->lock);
 884 }
 885
 886 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 887 {
 888         char *buffer;
 889
 890         buffer = vmalloc(user_len + 1);
 891         if (buffer == NULL)
 892                 return ERR_PTR(-ENOMEM);
 893         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 894                 vfree(buffer);
 895                 return ERR_PTR(-EFAULT);
 896         }
 897         /* got the string, now strip linefeed. */
 898         if (buffer[user_len - 1] == '\n')
 899                 buffer[user_len - 1] = 0;
 900         else
 901                 buffer[user_len] = 0;
 902         return buffer;
 903 }
 904
 905 static ssize_t dasd_stats_write(struct file *file,
 906                                 const char __user *user_buf,
 907                                 size_t user_len, loff_t *pos)
 908 {
 909         char *buffer, *str;
 910         int rc;
 911         struct seq_file *m = (struct seq_file *)file->private_data;
 912         struct dasd_profile *prof = m->private;
 913
 914         if (user_len > 65536)
 915                 user_len = 65536;
 916         buffer = dasd_get_user_string(user_buf, user_len);
 917         if (IS_ERR(buffer))
 918                 return PTR_ERR(buffer);
 919
 920         str = skip_spaces(buffer);
 921         rc = user_len;
 922         if (strncmp(str, "reset", 5) == 0) {
 923                 dasd_profile_reset(prof);
 924         } else if (strncmp(str, "on", 2) == 0) {
 925                 rc = dasd_profile_on(prof);
 926                 if (!rc)
 927                         rc = user_len;
 928         } else if (strncmp(str, "off", 3) == 0) {
 929                 dasd_profile_off(prof);
 930         } else
 931                 rc = -EINVAL;
 932         vfree(buffer);
 933         return rc;
 934 }
 935
 936 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 937 {
 938         int i;
 939
 940         for (i = 0; i < 32; i++)
 941                 seq_printf(m, "%u ", array[i]);
 942         seq_putc(m, '\n');
 943 }
 944
 945 static void dasd_stats_seq_print(struct seq_file *m,
 946                                  struct dasd_profile_info *data)
 947 {
 948         seq_printf(m, "start_time %ld.%09ld\n",
 949                    data->starttod.tv_sec, data->starttod.tv_nsec);
 950         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 951         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 952         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 953         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 954         seq_printf(m, "histogram_sectors ");
 955         dasd_stats_array(m, data->dasd_io_secs);
 956         seq_printf(m, "histogram_io_times ");
 957         dasd_stats_array(m, data->dasd_io_times);
 958         seq_printf(m, "histogram_io_times_weighted ");
 959         dasd_stats_array(m, data->dasd_io_timps);
 960         seq_printf(m, "histogram_time_build_to_ssch ");
 961         dasd_stats_array(m, data->dasd_io_time1);
 962         seq_printf(m, "histogram_time_ssch_to_irq ");
 963         dasd_stats_array(m, data->dasd_io_time2);
 964         seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
 965         dasd_stats_array(m, data->dasd_io_time2ps);
 966         seq_printf(m, "histogram_time_irq_to_end ");
 967         dasd_stats_array(m, data->dasd_io_time3);
 968         seq_printf(m, "histogram_ccw_queue_length ");
 969         dasd_stats_array(m, data->dasd_io_nr_req);
 970         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 971         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 972         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 973         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 974         seq_printf(m, "histogram_read_sectors ");
 975         dasd_stats_array(m, data->dasd_read_secs);
 976         seq_printf(m, "histogram_read_times ");
 977         dasd_stats_array(m, data->dasd_read_times);
 978         seq_printf(m, "histogram_read_time_build_to_ssch ");
 979         dasd_stats_array(m, data->dasd_read_time1);
 980         seq_printf(m, "histogram_read_time_ssch_to_irq ");
 981         dasd_stats_array(m, data->dasd_read_time2);
 982         seq_printf(m, "histogram_read_time_irq_to_end ");
 983         dasd_stats_array(m, data->dasd_read_time3);
 984         seq_printf(m, "histogram_read_ccw_queue_length ");
 985         dasd_stats_array(m, data->dasd_read_nr_req);
 986 }
 987
 988 static int dasd_stats_show(struct seq_file *m, void *v)
 989 {
 990         struct dasd_profile *profile;
 991         struct dasd_profile_info *data;
 992
 993         profile = m->private;
 994         spin_lock_bh(&profile->lock);
 995         data = profile->data;
 996         if (!data) {
 997                 spin_unlock_bh(&profile->lock);
 998                 seq_printf(m, "disabled\n");
 999                 return 0;
1000         }
1001         dasd_stats_seq_print(m, data);
1002         spin_unlock_bh(&profile->lock);
1003         return 0;
1004 }
1005
1006 static int dasd_stats_open(struct inode *inode, struct file *file)
1007 {
1008         struct dasd_profile *profile = inode->i_private;
1009         return single_open(file, dasd_stats_show, profile);
1010 }
1011
1012 static const struct file_operations dasd_stats_raw_fops = {
1013         .owner          = THIS_MODULE,
1014         .open           = dasd_stats_open,
1015         .read           = seq_read,
1016         .llseek         = seq_lseek,
1017         .release        = single_release,
1018         .write          = dasd_stats_write,
1019 };
1020
1021 static ssize_t dasd_stats_global_write(struct file *file,
1022                                        const char __user *user_buf,
1023                                        size_t user_len, loff_t *pos)
1024 {
1025         char *buffer, *str;
1026         ssize_t rc;
1027
1028         if (user_len > 65536)
1029                 user_len = 65536;
1030         buffer = dasd_get_user_string(user_buf, user_len);
1031         if (IS_ERR(buffer))
1032                 return PTR_ERR(buffer);
1033         str = skip_spaces(buffer);
1034         rc = user_len;
1035         if (strncmp(str, "reset", 5) == 0) {
1036                 dasd_global_profile_reset();
1037         } else if (strncmp(str, "on", 2) == 0) {
1038                 dasd_global_profile_reset();
1039                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1040         } else if (strncmp(str, "off", 3) == 0) {
1041                 dasd_global_profile_level = DASD_PROFILE_OFF;
1042         } else
1043                 rc = -EINVAL;
1044         vfree(buffer);
1045         return rc;
1046 }
1047
1048 static int dasd_stats_global_show(struct seq_file *m, void *v)
1049 {
1050         if (!dasd_global_profile_level) {
1051                 seq_printf(m, "disabled\n");
1052                 return 0;
1053         }
1054         dasd_stats_seq_print(m, &dasd_global_profile_data);
1055         return 0;
1056 }
1057
1058 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1059 {
1060         return single_open(file, dasd_stats_global_show, NULL);
1061 }
1062
1063 static const struct file_operations dasd_stats_global_fops = {
1064         .owner          = THIS_MODULE,
1065         .open           = dasd_stats_global_open,
1066         .read           = seq_read,
1067         .llseek         = seq_lseek,
1068         .release        = single_release,
1069         .write          = dasd_stats_global_write,
1070 };
1071
1072 static void dasd_profile_init(struct dasd_profile *profile,
1073                               struct dentry *base_dentry)
1074 {
1075         umode_t mode;
1076         struct dentry *pde;
1077
1078         if (!base_dentry)
1079                 return;
1080         profile->dentry = NULL;
1081         profile->data = NULL;
1082         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1083         pde = debugfs_create_file("statistics", mode, base_dentry,
1084                                   profile, &dasd_stats_raw_fops);
1085         if (pde && !IS_ERR(pde))
1086                 profile->dentry = pde;
1087         return;
1088 }
1089
1090 static void dasd_profile_exit(struct dasd_profile *profile)
1091 {
1092         dasd_profile_off(profile);
1093         if (profile->dentry) {
1094                 debugfs_remove(profile->dentry);
1095                 profile->dentry = NULL;
1096         }
1097 }
1098
1099 static void dasd_statistics_removeroot(void)
1100 {
1101         dasd_global_profile_level = DASD_PROFILE_OFF;
1102         if (dasd_global_profile_dentry) {
1103                 debugfs_remove(dasd_global_profile_dentry);
1104                 dasd_global_profile_dentry = NULL;
1105         }
1106         if (dasd_debugfs_global_entry)
1107                 debugfs_remove(dasd_debugfs_global_entry);
1108         if (dasd_debugfs_root_entry)
1109                 debugfs_remove(dasd_debugfs_root_entry);
1110 }
1111
1112 static void dasd_statistics_createroot(void)
1113 {
1114         umode_t mode;
1115         struct dentry *pde;
1116
1117         dasd_debugfs_root_entry = NULL;
1118         dasd_debugfs_global_entry = NULL;
1119         dasd_global_profile_dentry = NULL;
1120         pde = debugfs_create_dir("dasd", NULL);
1121         if (!pde || IS_ERR(pde))
1122                 goto error;
1123         dasd_debugfs_root_entry = pde;
1124         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1125         if (!pde || IS_ERR(pde))
1126                 goto error;
1127         dasd_debugfs_global_entry = pde;
1128
1129         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1130         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1131                                   NULL, &dasd_stats_global_fops);
1132         if (!pde || IS_ERR(pde))
1133                 goto error;
1134         dasd_global_profile_dentry = pde;
1135         return;
1136
1137 error:
1138         DBF_EVENT(DBF_ERR, "%s",
1139                   "Creation of the dasd debugfs interface failed");
1140         dasd_statistics_removeroot();
1141         return;
1142 }
1143
1144 #else
1145 #define dasd_profile_start(block, cqr, req) do {} while (0)
1146 #define dasd_profile_end(block, cqr, req) do {} while (0)
1147
1148 static void dasd_statistics_createroot(void)
1149 {
1150         return;
1151 }
1152
1153 static void dasd_statistics_removeroot(void)
1154 {
1155         return;
1156 }
1157
1158 int dasd_stats_generic_show(struct seq_file *m, void *v)
1159 {
1160         seq_printf(m, "Statistics are not activated in this kernel\n");
1161         return 0;
1162 }
1163
1164 static void dasd_profile_init(struct dasd_profile *profile,
1165                               struct dentry *base_dentry)
1166 {
1167         return;
1168 }
1169
1170 static void dasd_profile_exit(struct dasd_profile *profile)
1171 {
1172         return;
1173 }
1174
1175 int dasd_profile_on(struct dasd_profile *profile)
1176 {
1177         return 0;
1178 }
1179
1180 #endif                          /* CONFIG_DASD_PROFILE */
1181
1182 /*
1183  * Allocate memory for a channel program with 'cplength' channel
1184  * command words and 'datasize' additional space. There are two
1185  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1186  * memory and 2) dasd_smalloc_request uses the static ccw memory
1187  * that gets allocated for each device.
1188  */
1189 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1190                                           int datasize,
1191                                           struct dasd_device *device)
1192 {
1193         struct dasd_ccw_req *cqr;
1194
1195         /* Sanity checks */
1196         BUG_ON(datasize > PAGE_SIZE ||
1197              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1198
1199         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1200         if (cqr == NULL)
1201                 return ERR_PTR(-ENOMEM);
1202         cqr->cpaddr = NULL;
1203         if (cplength > 0) {
1204                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1205                                       GFP_ATOMIC | GFP_DMA);
1206                 if (cqr->cpaddr == NULL) {
1207                         kfree(cqr);
1208                         return ERR_PTR(-ENOMEM);
1209                 }
1210         }
1211         cqr->data = NULL;
1212         if (datasize > 0) {
1213                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1214                 if (cqr->data == NULL) {
1215                         kfree(cqr->cpaddr);
1216                         kfree(cqr);
1217                         return ERR_PTR(-ENOMEM);
1218                 }
1219         }
1220         cqr->magic =  magic;
1221         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1222         dasd_get_device(device);
1223         return cqr;
1224 }
1225
1226 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1227                                           int datasize,
1228                                           struct dasd_device *device)
1229 {
1230         unsigned long flags;
1231         struct dasd_ccw_req *cqr;
1232         char *data;
1233         int size;
1234
1235         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1236         if (cplength > 0)
1237                 size += cplength * sizeof(struct ccw1);
1238         if (datasize > 0)
1239                 size += datasize;
1240         spin_lock_irqsave(&device->mem_lock, flags);
1241         cqr = (struct dasd_ccw_req *)
1242                 dasd_alloc_chunk(&device->ccw_chunks, size);
1243         spin_unlock_irqrestore(&device->mem_lock, flags);
1244         if (cqr == NULL)
1245                 return ERR_PTR(-ENOMEM);
1246         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1247         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1248         cqr->cpaddr = NULL;
1249         if (cplength > 0) {
1250                 cqr->cpaddr = (struct ccw1 *) data;
1251                 data += cplength*sizeof(struct ccw1);
1252                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1253         }
1254         cqr->data = NULL;
1255         if (datasize > 0) {
1256                 cqr->data = data;
1257                 memset(cqr->data, 0, datasize);
1258         }
1259         cqr->magic = magic;
1260         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1261         dasd_get_device(device);
1262         return cqr;
1263 }
1264
1265 /*
1266  * Free memory of a channel program. This function needs to free all the
1267  * idal lists that might have been created by dasd_set_cda and the
1268  * struct dasd_ccw_req itself.
1269  */
1270 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1271 {
1272 #ifdef CONFIG_64BIT
1273         struct ccw1 *ccw;
1274
1275         /* Clear any idals used for the request. */
1276         ccw = cqr->cpaddr;
1277         do {
1278                 clear_normalized_cda(ccw);
1279         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1280 #endif
1281         kfree(cqr->cpaddr);
1282         kfree(cqr->data);
1283         kfree(cqr);
1284         dasd_put_device(device);
1285 }
1286
1287 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1288 {
1289         unsigned long flags;
1290
1291         spin_lock_irqsave(&device->mem_lock, flags);
1292         dasd_free_chunk(&device->ccw_chunks, cqr);
1293         spin_unlock_irqrestore(&device->mem_lock, flags);
1294         dasd_put_device(device);
1295 }
1296
1297 /*
1298  * Check discipline magic in cqr.
1299  */
1300 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1301 {
1302         struct dasd_device *device;
1303
1304         if (cqr == NULL)
1305                 return -EINVAL;
1306         device = cqr->startdev;
1307         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1308                 DBF_DEV_EVENT(DBF_WARNING, device,
1309                             " dasd_ccw_req 0x%08x magic doesn't match"
1310                             " discipline 0x%08x",
1311                             cqr->magic,
1312                             *(unsigned int *) device->discipline->name);
1313                 return -EINVAL;
1314         }
1315         return 0;
1316 }
1317
1318 /*
1319  * Terminate the current i/o and set the request to clear_pending.
1320  * Timer keeps device runnig.
1321  * ccw_device_clear can fail if the i/o subsystem
1322  * is in a bad mood.
1323  */
1324 int dasd_term_IO(struct dasd_ccw_req *cqr)
1325 {
1326         struct dasd_device *device;
1327         int retries, rc;
1328         char errorstring[ERRORLENGTH];
1329
1330         /* Check the cqr */
1331         rc = dasd_check_cqr(cqr);
1332         if (rc)
1333                 return rc;
1334         retries = 0;
1335         device = (struct dasd_device *) cqr->startdev;
1336         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1337                 rc = ccw_device_clear(device->cdev, (long) cqr);
1338                 switch (rc) {
1339                 case 0: /* termination successful */
1340                         cqr->status = DASD_CQR_CLEAR_PENDING;
1341                         cqr->stopclk = get_clock();
1342                         cqr->starttime = 0;
1343                         DBF_DEV_EVENT(DBF_DEBUG, device,
1344                                       "terminate cqr %p successful",
1345                                       cqr);
1346                         break;
1347                 case -ENODEV:
1348                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1349                                       "device gone, retry");
1350                         break;
1351                 case -EIO:
1352                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1353                                       "I/O error, retry");
1354                         break;
1355                 case -EINVAL:
1356                 case -EBUSY:
1357                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1358                                       "device busy, retry later");
1359                         break;
1360                 default:
1361                         /* internal error 10 - unknown rc*/
1362                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1363                         dev_err(&device->cdev->dev, "An error occurred in the "
1364                                 "DASD device driver, reason=%s\n", errorstring);
1365                         BUG();
1366                         break;
1367                 }
1368                 retries++;
1369         }
1370         dasd_schedule_device_bh(device);
1371         return rc;
1372 }
1373
1374 /*
1375  * Start the i/o. This start_IO can fail if the channel is really busy.
1376  * In that case set up a timer to start the request later.
1377  */
1378 int dasd_start_IO(struct dasd_ccw_req *cqr)
1379 {
1380         struct dasd_device *device;
1381         int rc;
1382         char errorstring[ERRORLENGTH];
1383
1384         /* Check the cqr */
1385         rc = dasd_check_cqr(cqr);
1386         if (rc) {
1387                 cqr->intrc = rc;
1388                 return rc;
1389         }
1390         device = (struct dasd_device *) cqr->startdev;
1391         if (((cqr->block &&
1392               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1393              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1394             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1395                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1396                               "because of stolen lock", cqr);
1397                 cqr->status = DASD_CQR_ERROR;
1398                 cqr->intrc = -EPERM;
1399                 return -EPERM;
1400         }
1401         if (cqr->retries < 0) {
1402                 /* internal error 14 - start_IO run out of retries */
1403                 sprintf(errorstring, "14 %p", cqr);
1404                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1405                         "device driver, reason=%s\n", errorstring);
1406                 cqr->status = DASD_CQR_ERROR;
1407                 return -EIO;
1408         }
1409         cqr->startclk = get_clock();
1410         cqr->starttime = jiffies;
1411         cqr->retries--;
1412         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1413                 cqr->lpm &= device->path_data.opm;
1414                 if (!cqr->lpm)
1415                         cqr->lpm = device->path_data.opm;
1416         }
1417         if (cqr->cpmode == 1) {
1418                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1419                                          (long) cqr, cqr->lpm);
1420         } else {
1421                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1422                                       (long) cqr, cqr->lpm, 0);
1423         }
1424         switch (rc) {
1425         case 0:
1426                 cqr->status = DASD_CQR_IN_IO;
1427                 break;
1428         case -EBUSY:
1429                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1430                               "start_IO: device busy, retry later");
1431                 break;
1432         case -ETIMEDOUT:
1433                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1434                               "start_IO: request timeout, retry later");
1435                 break;
1436         case -EACCES:
1437                 /* -EACCES indicates that the request used only a subset of the
1438                  * available paths and all these paths are gone. If the lpm of
1439                  * this request was only a subset of the opm (e.g. the ppm) then
1440                  * we just do a retry with all available paths.
1441                  * If we already use the full opm, something is amiss, and we
1442                  * need a full path verification.
1443                  */
1444                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1445                         DBF_DEV_EVENT(DBF_WARNING, device,
1446                                       "start_IO: selected paths gone (%x)",
1447                                       cqr->lpm);
1448                 } else if (cqr->lpm != device->path_data.opm) {
1449                         cqr->lpm = device->path_data.opm;
1450                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1451                                       "start_IO: selected paths gone,"
1452                                       " retry on all paths");
1453                 } else {
1454                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1455                                       "start_IO: all paths in opm gone,"
1456                                       " do path verification");
1457                         dasd_generic_last_path_gone(device);
1458                         device->path_data.opm = 0;
1459                         device->path_data.ppm = 0;
1460                         device->path_data.npm = 0;
1461                         device->path_data.tbvpm =
1462                                 ccw_device_get_path_mask(device->cdev);
1463                 }
1464                 break;
1465         case -ENODEV:
1466                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1467                               "start_IO: -ENODEV device gone, retry");
1468                 break;
1469         case -EIO:
1470                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1471                               "start_IO: -EIO device gone, retry");
1472                 break;
1473         case -EINVAL:
1474                 /* most likely caused in power management context */
1475                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1476                               "start_IO: -EINVAL device currently "
1477                               "not accessible");
1478                 break;
1479         default:
1480                 /* internal error 11 - unknown rc */
1481                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1482                 dev_err(&device->cdev->dev,
1483                         "An error occurred in the DASD device driver, "
1484                         "reason=%s\n", errorstring);
1485                 BUG();
1486                 break;
1487         }
1488         cqr->intrc = rc;
1489         return rc;
1490 }
1491
1492 /*
1493  * Timeout function for dasd devices. This is used for different purposes
1494  *  1) missing interrupt handler for normal operation
1495  *  2) delayed start of request where start_IO failed with -EBUSY
1496  *  3) timeout for missing state change interrupts
1497  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1498  * DASD_CQR_QUEUED for 2) and 3).
1499  */
1500 static void dasd_device_timeout(unsigned long ptr)
1501 {
1502         unsigned long flags;
1503         struct dasd_device *device;
1504
1505         device = (struct dasd_device *) ptr;
1506         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1507         /* re-activate request queue */
1508         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1509         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1510         dasd_schedule_device_bh(device);
1511 }
1512
1513 /*
1514  * Setup timeout for a device in jiffies.
1515  */
1516 void dasd_device_set_timer(struct dasd_device *device, int expires)
1517 {
1518         if (expires == 0)
1519                 del_timer(&device->timer);
1520         else
1521                 mod_timer(&device->timer, jiffies + expires);
1522 }
1523
1524 /*
1525  * Clear timeout for a device.
1526  */
1527 void dasd_device_clear_timer(struct dasd_device *device)
1528 {
1529         del_timer(&device->timer);
1530 }
1531
1532 static void dasd_handle_killed_request(struct ccw_device *cdev,
1533                                        unsigned long intparm)
1534 {
1535         struct dasd_ccw_req *cqr;
1536         struct dasd_device *device;
1537
1538         if (!intparm)
1539                 return;
1540         cqr = (struct dasd_ccw_req *) intparm;
1541         if (cqr->status != DASD_CQR_IN_IO) {
1542                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1543                                 "invalid status in handle_killed_request: "
1544                                 "%02x", cqr->status);
1545                 return;
1546         }
1547
1548         device = dasd_device_from_cdev_locked(cdev);
1549         if (IS_ERR(device)) {
1550                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1551                                 "unable to get device from cdev");
1552                 return;
1553         }
1554
1555         if (!cqr->startdev ||
1556             device != cqr->startdev ||
1557             strncmp(cqr->startdev->discipline->ebcname,
1558                     (char *) &cqr->magic, 4)) {
1559                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1560                                 "invalid device in request");
1561                 dasd_put_device(device);
1562                 return;
1563         }
1564
1565         /* Schedule request to be retried. */
1566         cqr->status = DASD_CQR_QUEUED;
1567
1568         dasd_device_clear_timer(device);
1569         dasd_schedule_device_bh(device);
1570         dasd_put_device(device);
1571 }
1572
1573 void dasd_generic_handle_state_change(struct dasd_device *device)
1574 {
1575         /* First of all start sense subsystem status request. */
1576         dasd_eer_snss(device);
1577
1578         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1579         dasd_schedule_device_bh(device);
1580         if (device->block)
1581                 dasd_schedule_block_bh(device->block);
1582 }
1583
1584 /*
1585  * Interrupt handler for "normal" ssch-io based dasd devices.
1586  */
1587 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1588                       struct irb *irb)
1589 {
1590         struct dasd_ccw_req *cqr, *next;
1591         struct dasd_device *device;
1592         unsigned long long now;
1593         int expires;
1594
1595         if (IS_ERR(irb)) {
1596                 switch (PTR_ERR(irb)) {
1597                 case -EIO:
1598                         break;
1599                 case -ETIMEDOUT:
1600                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1601                                         "request timed out\n", __func__);
1602                         break;
1603                 default:
1604                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1605                                         "unknown error %ld\n", __func__,
1606                                         PTR_ERR(irb));
1607                 }
1608                 dasd_handle_killed_request(cdev, intparm);
1609                 return;
1610         }
1611
1612         now = get_clock();
1613         cqr = (struct dasd_ccw_req *) intparm;
1614         /* check for conditions that should be handled immediately */
1615         if (!cqr ||
1616             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1617               scsw_cstat(&irb->scsw) == 0)) {
1618                 if (cqr)
1619                         memcpy(&cqr->irb, irb, sizeof(*irb));
1620                 device = dasd_device_from_cdev_locked(cdev);
1621                 if (IS_ERR(device))
1622                         return;
1623                 /* ignore unsolicited interrupts for DIAG discipline */
1624                 if (device->discipline == dasd_diag_discipline_pointer) {
1625                         dasd_put_device(device);
1626                         return;
1627                 }
1628                 device->discipline->dump_sense_dbf(device, irb, "int");
1629                 if (device->features & DASD_FEATURE_ERPLOG)
1630                         device->discipline->dump_sense(device, cqr, irb);
1631                 device->discipline->check_for_device_change(device, cqr, irb);
1632                 dasd_put_device(device);
1633         }
1634         if (!cqr)
1635                 return;
1636
1637         device = (struct dasd_device *) cqr->startdev;
1638         if (!device ||
1639             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1640                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1641                                 "invalid device in request");
1642                 return;
1643         }
1644
1645         /* Check for clear pending */
1646         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1647             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1648                 cqr->status = DASD_CQR_CLEARED;
1649                 dasd_device_clear_timer(device);
1650                 wake_up(&dasd_flush_wq);
1651                 dasd_schedule_device_bh(device);
1652                 return;
1653         }
1654
1655         /* check status - the request might have been killed by dyn detach */
1656         if (cqr->status != DASD_CQR_IN_IO) {
1657                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1658                               "status %02x", dev_name(&cdev->dev), cqr->status);
1659                 return;
1660         }
1661
1662         next = NULL;
1663         expires = 0;
1664         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1665             scsw_cstat(&irb->scsw) == 0) {
1666                 /* request was completed successfully */
1667                 cqr->status = DASD_CQR_SUCCESS;
1668                 cqr->stopclk = now;
1669                 /* Start first request on queue if possible -> fast_io. */
1670                 if (cqr->devlist.next != &device->ccw_queue) {
1671                         next = list_entry(cqr->devlist.next,
1672                                           struct dasd_ccw_req, devlist);
1673                 }
1674         } else {  /* error */
1675                 /*
1676                  * If we don't want complex ERP for this request, then just
1677                  * reset this and retry it in the fastpath
1678                  */
1679                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1680                     cqr->retries > 0) {
1681                         if (cqr->lpm == device->path_data.opm)
1682                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1683                                               "default ERP in fastpath "
1684                                               "(%i retries left)",
1685                                               cqr->retries);
1686                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1687                                 cqr->lpm = device->path_data.opm;
1688                         cqr->status = DASD_CQR_QUEUED;
1689                         next = cqr;
1690                 } else
1691                         cqr->status = DASD_CQR_ERROR;
1692         }
1693         if (next && (next->status == DASD_CQR_QUEUED) &&
1694             (!device->stopped)) {
1695                 if (device->discipline->start_IO(next) == 0)
1696                         expires = next->expires;
1697         }
1698         if (expires != 0)
1699                 dasd_device_set_timer(device, expires);
1700         else
1701                 dasd_device_clear_timer(device);
1702         dasd_schedule_device_bh(device);
1703 }
1704
1705 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1706 {
1707         struct dasd_device *device;
1708
1709         device = dasd_device_from_cdev_locked(cdev);
1710
1711         if (IS_ERR(device))
1712                 goto out;
1713         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1714            device->state != device->target ||
1715            !device->discipline->check_for_device_change){
1716                 dasd_put_device(device);
1717                 goto out;
1718         }
1719         if (device->discipline->dump_sense_dbf)
1720                 device->discipline->dump_sense_dbf(device, irb, "uc");
1721         device->discipline->check_for_device_change(device, NULL, irb);
1722         dasd_put_device(device);
1723 out:
1724         return UC_TODO_RETRY;
1725 }
1726 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1727
1728 /*
1729  * If we have an error on a dasd_block layer request then we cancel
1730  * and return all further requests from the same dasd_block as well.
1731  */
1732 static void __dasd_device_recovery(struct dasd_device *device,
1733                                    struct dasd_ccw_req *ref_cqr)
1734 {
1735         struct list_head *l, *n;
1736         struct dasd_ccw_req *cqr;
1737
1738         /*
1739          * only requeue request that came from the dasd_block layer
1740          */
1741         if (!ref_cqr->block)
1742                 return;
1743
1744         list_for_each_safe(l, n, &device->ccw_queue) {
1745                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1746                 if (cqr->status == DASD_CQR_QUEUED &&
1747                     ref_cqr->block == cqr->block) {
1748                         cqr->status = DASD_CQR_CLEARED;
1749                 }
1750         }
1751 };
1752
1753 /*
1754  * Remove those ccw requests from the queue that need to be returned
1755  * to the upper layer.
1756  */
1757 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1758                                             struct list_head *final_queue)
1759 {
1760         struct list_head *l, *n;
1761         struct dasd_ccw_req *cqr;
1762
1763         /* Process request with final status. */
1764         list_for_each_safe(l, n, &device->ccw_queue) {
1765                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1766
1767                 /* Stop list processing at the first non-final request. */
1768                 if (cqr->status == DASD_CQR_QUEUED ||
1769                     cqr->status == DASD_CQR_IN_IO ||
1770                     cqr->status == DASD_CQR_CLEAR_PENDING)
1771                         break;
1772                 if (cqr->status == DASD_CQR_ERROR) {
1773                         __dasd_device_recovery(device, cqr);
1774                 }
1775                 /* Rechain finished requests to final queue */
1776                 list_move_tail(&cqr->devlist, final_queue);
1777         }
1778 }
1779
1780 /*
1781  * the cqrs from the final queue are returned to the upper layer
1782  * by setting a dasd_block state and calling the callback function
1783  */
1784 static void __dasd_device_process_final_queue(struct dasd_device *device,
1785                                               struct list_head *final_queue)
1786 {
1787         struct list_head *l, *n;
1788         struct dasd_ccw_req *cqr;
1789         struct dasd_block *block;
1790         void (*callback)(struct dasd_ccw_req *, void *data);
1791         void *callback_data;
1792         char errorstring[ERRORLENGTH];
1793
1794         list_for_each_safe(l, n, final_queue) {
1795                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1796                 list_del_init(&cqr->devlist);
1797                 block = cqr->block;
1798                 callback = cqr->callback;
1799                 callback_data = cqr->callback_data;
1800                 if (block)
1801                         spin_lock_bh(&block->queue_lock);
1802                 switch (cqr->status) {
1803                 case DASD_CQR_SUCCESS:
1804                         cqr->status = DASD_CQR_DONE;
1805                         break;
1806                 case DASD_CQR_ERROR:
1807                         cqr->status = DASD_CQR_NEED_ERP;
1808                         break;
1809                 case DASD_CQR_CLEARED:
1810                         cqr->status = DASD_CQR_TERMINATED;
1811                         break;
1812                 default:
1813                         /* internal error 12 - wrong cqr status*/
1814                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1815                         dev_err(&device->cdev->dev,
1816                                 "An error occurred in the DASD device driver, "
1817                                 "reason=%s\n", errorstring);
1818                         BUG();
1819                 }
1820                 if (cqr->callback != NULL)
1821                         (callback)(cqr, callback_data);
1822                 if (block)
1823                         spin_unlock_bh(&block->queue_lock);
1824         }
1825 }
1826
1827 /*
1828  * Take a look at the first request on the ccw queue and check
1829  * if it reached its expire time. If so, terminate the IO.
1830  */
1831 static void __dasd_device_check_expire(struct dasd_device *device)
1832 {
1833         struct dasd_ccw_req *cqr;
1834
1835         if (list_empty(&device->ccw_queue))
1836                 return;
1837         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1838         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1839             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1840                 if (device->discipline->term_IO(cqr) != 0) {
1841                         /* Hmpf, try again in 5 sec */
1842                         dev_err(&device->cdev->dev,
1843                                 "cqr %p timed out (%lus) but cannot be "
1844                                 "ended, retrying in 5 s\n",
1845                                 cqr, (cqr->expires/HZ));
1846                         cqr->expires += 5*HZ;
1847                         dasd_device_set_timer(device, 5*HZ);
1848                 } else {
1849                         dev_err(&device->cdev->dev,
1850                                 "cqr %p timed out (%lus), %i retries "
1851                                 "remaining\n", cqr, (cqr->expires/HZ),
1852                                 cqr->retries);
1853                 }
1854         }
1855 }
1856
1857 /*
1858  * Take a look at the first request on the ccw queue and check
1859  * if it needs to be started.
1860  */
1861 static void __dasd_device_start_head(struct dasd_device *device)
1862 {
1863         struct dasd_ccw_req *cqr;
1864         int rc;
1865
1866         if (list_empty(&device->ccw_queue))
1867                 return;
1868         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1869         if (cqr->status != DASD_CQR_QUEUED)
1870                 return;
1871         /* when device is stopped, return request to previous layer
1872          * exception: only the disconnect or unresumed bits are set and the
1873          * cqr is a path verification request
1874          */
1875         if (device->stopped &&
1876             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1877               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1878                 cqr->intrc = -EAGAIN;
1879                 cqr->status = DASD_CQR_CLEARED;
1880                 dasd_schedule_device_bh(device);
1881                 return;
1882         }
1883
1884         rc = device->discipline->start_IO(cqr);
1885         if (rc == 0)
1886                 dasd_device_set_timer(device, cqr->expires);
1887         else if (rc == -EACCES) {
1888                 dasd_schedule_device_bh(device);
1889         } else
1890                 /* Hmpf, try again in 1/2 sec */
1891                 dasd_device_set_timer(device, 50);
1892 }
1893
1894 static void __dasd_device_check_path_events(struct dasd_device *device)
1895 {
1896         int rc;
1897
1898         if (device->path_data.tbvpm) {
1899                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1900                                         DASD_UNRESUMED_PM))
1901                         return;
1902                 rc = device->discipline->verify_path(
1903                         device, device->path_data.tbvpm);
1904                 if (rc)
1905                         dasd_device_set_timer(device, 50);
1906                 else
1907                         device->path_data.tbvpm = 0;
1908         }
1909 };
1910
1911 /*
1912  * Go through all request on the dasd_device request queue,
1913  * terminate them on the cdev if necessary, and return them to the
1914  * submitting layer via callback.
1915  * Note:
1916  * Make sure that all 'submitting layers' still exist when
1917  * this function is called!. In other words, when 'device' is a base
1918  * device then all block layer requests must have been removed before
1919  * via dasd_flush_block_queue.
1920  */
1921 int dasd_flush_device_queue(struct dasd_device *device)
1922 {
1923         struct dasd_ccw_req *cqr, *n;
1924         int rc;
1925         struct list_head flush_queue;
1926
1927         INIT_LIST_HEAD(&flush_queue);
1928         spin_lock_irq(get_ccwdev_lock(device->cdev));
1929         rc = 0;
1930         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1931                 /* Check status and move request to flush_queue */
1932                 switch (cqr->status) {
1933                 case DASD_CQR_IN_IO:
1934                         rc = device->discipline->term_IO(cqr);
1935                         if (rc) {
1936                                 /* unable to terminate requeust */
1937                                 dev_err(&device->cdev->dev,
1938                                         "Flushing the DASD request queue "
1939                                         "failed for request %p\n", cqr);
1940                                 /* stop flush processing */
1941                                 goto finished;
1942                         }
1943                         break;
1944                 case DASD_CQR_QUEUED:
1945                         cqr->stopclk = get_clock();
1946                         cqr->status = DASD_CQR_CLEARED;
1947                         break;
1948                 default: /* no need to modify the others */
1949                         break;
1950                 }
1951                 list_move_tail(&cqr->devlist, &flush_queue);
1952         }
1953 finished:
1954         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1955         /*
1956          * After this point all requests must be in state CLEAR_PENDING,
1957          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1958          * one of the others.
1959          */
1960         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1961                 wait_event(dasd_flush_wq,
1962                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1963         /*
1964          * Now set each request back to TERMINATED, DONE or NEED_ERP
1965          * and call the callback function of flushed requests
1966          */
1967         __dasd_device_process_final_queue(device, &flush_queue);
1968         return rc;
1969 }
1970
1971 /*
1972  * Acquire the device lock and process queues for the device.
1973  */
1974 static void dasd_device_tasklet(struct dasd_device *device)
1975 {
1976         struct list_head final_queue;
1977
1978         atomic_set (&device->tasklet_scheduled, 0);
1979         INIT_LIST_HEAD(&final_queue);
1980         spin_lock_irq(get_ccwdev_lock(device->cdev));
1981         /* Check expire time of first request on the ccw queue. */
1982         __dasd_device_check_expire(device);
1983         /* find final requests on ccw queue */
1984         __dasd_device_process_ccw_queue(device, &final_queue);
1985         __dasd_device_check_path_events(device);
1986         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1987         /* Now call the callback function of requests with final status */
1988         __dasd_device_process_final_queue(device, &final_queue);
1989         spin_lock_irq(get_ccwdev_lock(device->cdev));
1990         /* Now check if the head of the ccw queue needs to be started. */
1991         __dasd_device_start_head(device);
1992         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1993         dasd_put_device(device);
1994 }
1995
1996 /*
1997  * Schedules a call to dasd_tasklet over the device tasklet.
1998  */
1999 void dasd_schedule_device_bh(struct dasd_device *device)
2000 {
2001         /* Protect against rescheduling. */
2002         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2003                 return;
2004         dasd_get_device(device);
2005         tasklet_hi_schedule(&device->tasklet);
2006 }
2007
2008 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2009 {
2010         device->stopped |= bits;
2011 }
2012 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2013
2014 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2015 {
2016         device->stopped &= ~bits;
2017         if (!device->stopped)
2018                 wake_up(&generic_waitq);
2019 }
2020 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2021
2022 /*
2023  * Queue a request to the head of the device ccw_queue.
2024  * Start the I/O if possible.
2025  */
2026 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2027 {
2028         struct dasd_device *device;
2029         unsigned long flags;
2030
2031         device = cqr->startdev;
2032         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2033         cqr->status = DASD_CQR_QUEUED;
2034         list_add(&cqr->devlist, &device->ccw_queue);
2035         /* let the bh start the request to keep them in order */
2036         dasd_schedule_device_bh(device);
2037         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2038 }
2039
2040 /*
2041  * Queue a request to the tail of the device ccw_queue.
2042  * Start the I/O if possible.
2043  */
2044 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2045 {
2046         struct dasd_device *device;
2047         unsigned long flags;
2048
2049         device = cqr->startdev;
2050         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2051         cqr->status = DASD_CQR_QUEUED;
2052         list_add_tail(&cqr->devlist, &device->ccw_queue);
2053         /* let the bh start the request to keep them in order */
2054         dasd_schedule_device_bh(device);
2055         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2056 }
2057
2058 /*
2059  * Wakeup helper for the 'sleep_on' functions.
2060  */
2061 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2062 {
2063         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2064         cqr->callback_data = DASD_SLEEPON_END_TAG;
2065         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2066         wake_up(&generic_waitq);
2067 }
2068 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2069
2070 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2071 {
2072         struct dasd_device *device;
2073         int rc;
2074
2075         device = cqr->startdev;
2076         spin_lock_irq(get_ccwdev_lock(device->cdev));
2077         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2078         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2079         return rc;
2080 }
2081
2082 /*
2083  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2084  */
2085 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2086 {
2087         struct dasd_device *device;
2088         dasd_erp_fn_t erp_fn;
2089
2090         if (cqr->status == DASD_CQR_FILLED)
2091                 return 0;
2092         device = cqr->startdev;
2093         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2094                 if (cqr->status == DASD_CQR_TERMINATED) {
2095                         device->discipline->handle_terminated_request(cqr);
2096                         return 1;
2097                 }
2098                 if (cqr->status == DASD_CQR_NEED_ERP) {
2099                         erp_fn = device->discipline->erp_action(cqr);
2100                         erp_fn(cqr);
2101                         return 1;
2102                 }
2103                 if (cqr->status == DASD_CQR_FAILED)
2104                         dasd_log_sense(cqr, &cqr->irb);
2105                 if (cqr->refers) {
2106                         __dasd_process_erp(device, cqr);
2107                         return 1;
2108                 }
2109         }
2110         return 0;
2111 }
2112
2113 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2114 {
2115         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2116                 if (cqr->refers) /* erp is not done yet */
2117                         return 1;
2118                 return ((cqr->status != DASD_CQR_DONE) &&
2119                         (cqr->status != DASD_CQR_FAILED));
2120         } else
2121                 return (cqr->status == DASD_CQR_FILLED);
2122 }
2123
2124 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2125 {
2126         struct dasd_device *device;
2127         int rc;
2128         struct list_head ccw_queue;
2129         struct dasd_ccw_req *cqr;
2130
2131         INIT_LIST_HEAD(&ccw_queue);
2132         maincqr->status = DASD_CQR_FILLED;
2133         device = maincqr->startdev;
2134         list_add(&maincqr->blocklist, &ccw_queue);
2135         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2136              cqr = list_first_entry(&ccw_queue,
2137                                     struct dasd_ccw_req, blocklist)) {
2138
2139                 if (__dasd_sleep_on_erp(cqr))
2140                         continue;
2141                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2142                         continue;
2143                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2144                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2145                         cqr->status = DASD_CQR_FAILED;
2146                         cqr->intrc = -EPERM;
2147                         continue;
2148                 }
2149                 /* Non-temporary stop condition will trigger fail fast */
2150                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2151                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2152                     (!dasd_eer_enabled(device))) {
2153                         cqr->status = DASD_CQR_FAILED;
2154                         continue;
2155                 }
2156                 /* Don't try to start requests if device is stopped */
2157                 if (interruptible) {
2158                         rc = wait_event_interruptible(
2159                                 generic_waitq, !(device->stopped));
2160                         if (rc == -ERESTARTSYS) {
2161                                 cqr->status = DASD_CQR_FAILED;
2162                                 maincqr->intrc = rc;
2163                                 continue;
2164                         }
2165                 } else
2166                         wait_event(generic_waitq, !(device->stopped));
2167
2168                 if (!cqr->callback)
2169                         cqr->callback = dasd_wakeup_cb;
2170
2171                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2172                 dasd_add_request_tail(cqr);
2173                 if (interruptible) {
2174                         rc = wait_event_interruptible(
2175                                 generic_waitq, _wait_for_wakeup(cqr));
2176                         if (rc == -ERESTARTSYS) {
2177                                 dasd_cancel_req(cqr);
2178                                 /* wait (non-interruptible) for final status */
2179                                 wait_event(generic_waitq,
2180                                            _wait_for_wakeup(cqr));
2181                                 cqr->status = DASD_CQR_FAILED;
2182                                 maincqr->intrc = rc;
2183                                 continue;
2184                         }
2185                 } else
2186                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2187         }
2188
2189         maincqr->endclk = get_clock();
2190         if ((maincqr->status != DASD_CQR_DONE) &&
2191             (maincqr->intrc != -ERESTARTSYS))
2192                 dasd_log_sense(maincqr, &maincqr->irb);
2193         if (maincqr->status == DASD_CQR_DONE)
2194                 rc = 0;
2195         else if (maincqr->intrc)
2196                 rc = maincqr->intrc;
2197         else
2198                 rc = -EIO;
2199         return rc;
2200 }
2201
2202 /*
2203  * Queue a request to the tail of the device ccw_queue and wait for
2204  * it's completion.
2205  */
2206 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2207 {
2208         return _dasd_sleep_on(cqr, 0);
2209 }
2210
2211 /*
2212  * Queue a request to the tail of the device ccw_queue and wait
2213  * interruptible for it's completion.
2214  */
2215 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2216 {
2217         return _dasd_sleep_on(cqr, 1);
2218 }
2219
2220 /*
2221  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2222  * for eckd devices) the currently running request has to be terminated
2223  * and be put back to status queued, before the special request is added
2224  * to the head of the queue. Then the special request is waited on normally.
2225  */
2226 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2227 {
2228         struct dasd_ccw_req *cqr;
2229         int rc;
2230
2231         if (list_empty(&device->ccw_queue))
2232                 return 0;
2233         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2234         rc = device->discipline->term_IO(cqr);
2235         if (!rc)
2236                 /*
2237                  * CQR terminated because a more important request is pending.
2238                  * Undo decreasing of retry counter because this is
2239                  * not an error case.
2240                  */
2241                 cqr->retries++;
2242         return rc;
2243 }
2244
2245 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2246 {
2247         struct dasd_device *device;
2248         int rc;
2249
2250         device = cqr->startdev;
2251         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2252             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2253                 cqr->status = DASD_CQR_FAILED;
2254                 cqr->intrc = -EPERM;
2255                 return -EIO;
2256         }
2257         spin_lock_irq(get_ccwdev_lock(device->cdev));
2258         rc = _dasd_term_running_cqr(device);
2259         if (rc) {
2260                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2261                 return rc;
2262         }
2263         cqr->callback = dasd_wakeup_cb;
2264         cqr->callback_data = DASD_SLEEPON_START_TAG;
2265         cqr->status = DASD_CQR_QUEUED;
2266         /*
2267          * add new request as second
2268          * first the terminated cqr needs to be finished
2269          */
2270         list_add(&cqr->devlist, device->ccw_queue.next);
2271
2272         /* let the bh start the request to keep them in order */
2273         dasd_schedule_device_bh(device);
2274
2275         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2276
2277         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2278
2279         if (cqr->status == DASD_CQR_DONE)
2280                 rc = 0;
2281         else if (cqr->intrc)
2282                 rc = cqr->intrc;
2283         else
2284                 rc = -EIO;
2285         return rc;
2286 }
2287
2288 /*
2289  * Cancels a request that was started with dasd_sleep_on_req.
2290  * This is useful to timeout requests. The request will be
2291  * terminated if it is currently in i/o.
2292  * Returns 1 if the request has been terminated.
2293  *         0 if there was no need to terminate the request (not started yet)
2294  *         negative error code if termination failed
2295  * Cancellation of a request is an asynchronous operation! The calling
2296  * function has to wait until the request is properly returned via callback.
2297  */
2298 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2299 {
2300         struct dasd_device *device = cqr->startdev;
2301         unsigned long flags;
2302         int rc;
2303
2304         rc = 0;
2305         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2306         switch (cqr->status) {
2307         case DASD_CQR_QUEUED:
2308                 /* request was not started - just set to cleared */
2309                 cqr->status = DASD_CQR_CLEARED;
2310                 break;
2311         case DASD_CQR_IN_IO:
2312                 /* request in IO - terminate IO and release again */
2313                 rc = device->discipline->term_IO(cqr);
2314                 if (rc) {
2315                         dev_err(&device->cdev->dev,
2316                                 "Cancelling request %p failed with rc=%d\n",
2317                                 cqr, rc);
2318                 } else {
2319                         cqr->stopclk = get_clock();
2320                 }
2321                 break;
2322         default: /* already finished or clear pending - do nothing */
2323                 break;
2324         }
2325         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2326         dasd_schedule_device_bh(device);
2327         return rc;
2328 }
2329
2330
2331 /*
2332  * SECTION: Operations of the dasd_block layer.
2333  */
2334
2335 /*
2336  * Timeout function for dasd_block. This is used when the block layer
2337  * is waiting for something that may not come reliably, (e.g. a state
2338  * change interrupt)
2339  */
2340 static void dasd_block_timeout(unsigned long ptr)
2341 {
2342         unsigned long flags;
2343         struct dasd_block *block;
2344
2345         block = (struct dasd_block *) ptr;
2346         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2347         /* re-activate request queue */
2348         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2349         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2350         dasd_schedule_block_bh(block);
2351 }
2352
2353 /*
2354  * Setup timeout for a dasd_block in jiffies.
2355  */
2356 void dasd_block_set_timer(struct dasd_block *block, int expires)
2357 {
2358         if (expires == 0)
2359                 del_timer(&block->timer);
2360         else
2361                 mod_timer(&block->timer, jiffies + expires);
2362 }
2363
2364 /*
2365  * Clear timeout for a dasd_block.
2366  */
2367 void dasd_block_clear_timer(struct dasd_block *block)
2368 {
2369         del_timer(&block->timer);
2370 }
2371
2372 /*
2373  * Process finished error recovery ccw.
2374  */
2375 static void __dasd_process_erp(struct dasd_device *device,
2376                                struct dasd_ccw_req *cqr)
2377 {
2378         dasd_erp_fn_t erp_fn;
2379
2380         if (cqr->status == DASD_CQR_DONE)
2381                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2382         else
2383                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2384         erp_fn = device->discipline->erp_postaction(cqr);
2385         erp_fn(cqr);
2386 }
2387
2388 /*
2389  * Fetch requests from the block device queue.
2390  */
2391 static void __dasd_process_request_queue(struct dasd_block *block)
2392 {
2393         struct request_queue *queue;
2394         struct request *req;
2395         struct dasd_ccw_req *cqr;
2396         struct dasd_device *basedev;
2397         unsigned long flags;
2398         queue = block->request_queue;
2399         basedev = block->base;
2400         /* No queue ? Then there is nothing to do. */
2401         if (queue == NULL)
2402                 return;
2403
2404         /*
2405          * We requeue request from the block device queue to the ccw
2406          * queue only in two states. In state DASD_STATE_READY the
2407          * partition detection is done and we need to requeue requests
2408          * for that. State DASD_STATE_ONLINE is normal block device
2409          * operation.
2410          */
2411         if (basedev->state < DASD_STATE_READY) {
2412                 while ((req = blk_fetch_request(block->request_queue)))
2413                         __blk_end_request_all(req, -EIO);
2414                 return;
2415         }
2416         /* Now we try to fetch requests from the request queue */
2417         while ((req = blk_peek_request(queue))) {
2418                 if (basedev->features & DASD_FEATURE_READONLY &&
2419                     rq_data_dir(req) == WRITE) {
2420                         DBF_DEV_EVENT(DBF_ERR, basedev,
2421                                       "Rejecting write request %p",
2422                                       req);
2423                         blk_start_request(req);
2424                         __blk_end_request_all(req, -EIO);
2425                         continue;
2426                 }
2427                 cqr = basedev->discipline->build_cp(basedev, block, req);
2428                 if (IS_ERR(cqr)) {
2429                         if (PTR_ERR(cqr) == -EBUSY)
2430                                 break;  /* normal end condition */
2431                         if (PTR_ERR(cqr) == -ENOMEM)
2432                                 break;  /* terminate request queue loop */
2433                         if (PTR_ERR(cqr) == -EAGAIN) {
2434                                 /*
2435                                  * The current request cannot be build right
2436                                  * now, we have to try later. If this request
2437                                  * is the head-of-queue we stop the device
2438                                  * for 1/2 second.
2439                                  */
2440                                 if (!list_empty(&block->ccw_queue))
2441                                         break;
2442                                 spin_lock_irqsave(
2443                                         get_ccwdev_lock(basedev->cdev), flags);
2444                                 dasd_device_set_stop_bits(basedev,
2445                                                           DASD_STOPPED_PENDING);
2446                                 spin_unlock_irqrestore(
2447                                         get_ccwdev_lock(basedev->cdev), flags);
2448                                 dasd_block_set_timer(block, HZ/2);
2449                                 break;
2450                         }
2451                         DBF_DEV_EVENT(DBF_ERR, basedev,
2452                                       "CCW creation failed (rc=%ld) "
2453                                       "on request %p",
2454                                       PTR_ERR(cqr), req);
2455                         blk_start_request(req);
2456                         __blk_end_request_all(req, -EIO);
2457                         continue;
2458                 }
2459                 /*
2460                  *  Note: callback is set to dasd_return_cqr_cb in
2461                  * __dasd_block_start_head to cover erp requests as well
2462                  */
2463                 cqr->callback_data = (void *) req;
2464                 cqr->status = DASD_CQR_FILLED;
2465                 blk_start_request(req);
2466                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2467                 dasd_profile_start(block, cqr, req);
2468         }
2469 }
2470
2471 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2472 {
2473         struct request *req;
2474         int status;
2475         int error = 0;
2476
2477         req = (struct request *) cqr->callback_data;
2478         dasd_profile_end(cqr->block, cqr, req);
2479         status = cqr->block->base->discipline->free_cp(cqr, req);
2480         if (status <= 0)
2481                 error = status ? status : -EIO;
2482         __blk_end_request_all(req, error);
2483 }
2484
2485 /*
2486  * Process ccw request queue.
2487  */
2488 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2489                                            struct list_head *final_queue)
2490 {
2491         struct list_head *l, *n;
2492         struct dasd_ccw_req *cqr;
2493         dasd_erp_fn_t erp_fn;
2494         unsigned long flags;
2495         struct dasd_device *base = block->base;
2496
2497 restart:
2498         /* Process request with final status. */
2499         list_for_each_safe(l, n, &block->ccw_queue) {
2500                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2501                 if (cqr->status != DASD_CQR_DONE &&
2502                     cqr->status != DASD_CQR_FAILED &&
2503                     cqr->status != DASD_CQR_NEED_ERP &&
2504                     cqr->status != DASD_CQR_TERMINATED)
2505                         continue;
2506
2507                 if (cqr->status == DASD_CQR_TERMINATED) {
2508                         base->discipline->handle_terminated_request(cqr);
2509                         goto restart;
2510                 }
2511
2512                 /*  Process requests that may be recovered */
2513                 if (cqr->status == DASD_CQR_NEED_ERP) {
2514                         erp_fn = base->discipline->erp_action(cqr);
2515                         if (IS_ERR(erp_fn(cqr)))
2516                                 continue;
2517                         goto restart;
2518                 }
2519
2520                 /* log sense for fatal error */
2521                 if (cqr->status == DASD_CQR_FAILED) {
2522                         dasd_log_sense(cqr, &cqr->irb);
2523                 }
2524
2525                 /* First of all call extended error reporting. */
2526                 if (dasd_eer_enabled(base) &&
2527                     cqr->status == DASD_CQR_FAILED) {
2528                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2529
2530                         /* restart request  */
2531                         cqr->status = DASD_CQR_FILLED;
2532                         cqr->retries = 255;
2533                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2534                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2535                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2536                                                flags);
2537                         goto restart;
2538                 }
2539
2540                 /* Process finished ERP request. */
2541                 if (cqr->refers) {
2542                         __dasd_process_erp(base, cqr);
2543                         goto restart;
2544                 }
2545
2546                 /* Rechain finished requests to final queue */
2547                 cqr->endclk = get_clock();
2548                 list_move_tail(&cqr->blocklist, final_queue);
2549         }
2550 }
2551
2552 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2553 {
2554         dasd_schedule_block_bh(cqr->block);
2555 }
2556
2557 static void __dasd_block_start_head(struct dasd_block *block)
2558 {
2559         struct dasd_ccw_req *cqr;
2560
2561         if (list_empty(&block->ccw_queue))
2562                 return;
2563         /* We allways begin with the first requests on the queue, as some
2564          * of previously started requests have to be enqueued on a
2565          * dasd_device again for error recovery.
2566          */
2567         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2568                 if (cqr->status != DASD_CQR_FILLED)
2569                         continue;
2570                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2571                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2572                         cqr->status = DASD_CQR_FAILED;
2573                         cqr->intrc = -EPERM;
2574                         dasd_schedule_block_bh(block);
2575                         continue;
2576                 }
2577                 /* Non-temporary stop condition will trigger fail fast */
2578                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2579                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2580                     (!dasd_eer_enabled(block->base))) {
2581                         cqr->status = DASD_CQR_FAILED;
2582                         dasd_schedule_block_bh(block);
2583                         continue;
2584                 }
2585                 /* Don't try to start requests if device is stopped */
2586                 if (block->base->stopped)
2587                         return;
2588
2589                 /* just a fail safe check, should not happen */
2590                 if (!cqr->startdev)
2591                         cqr->startdev = block->base;
2592
2593                 /* make sure that the requests we submit find their way back */
2594                 cqr->callback = dasd_return_cqr_cb;
2595
2596                 dasd_add_request_tail(cqr);
2597         }
2598 }
2599
2600 /*
2601  * Central dasd_block layer routine. Takes requests from the generic
2602  * block layer request queue, creates ccw requests, enqueues them on
2603  * a dasd_device and processes ccw requests that have been returned.
2604  */
2605 static void dasd_block_tasklet(struct dasd_block *block)
2606 {
2607         struct list_head final_queue;
2608         struct list_head *l, *n;
2609         struct dasd_ccw_req *cqr;
2610
2611         atomic_set(&block->tasklet_scheduled, 0);
2612         INIT_LIST_HEAD(&final_queue);
2613         spin_lock(&block->queue_lock);
2614         /* Finish off requests on ccw queue */
2615         __dasd_process_block_ccw_queue(block, &final_queue);
2616         spin_unlock(&block->queue_lock);
2617         /* Now call the callback function of requests with final status */
2618         spin_lock_irq(&block->request_queue_lock);
2619         list_for_each_safe(l, n, &final_queue) {
2620                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2621                 list_del_init(&cqr->blocklist);
2622                 __dasd_cleanup_cqr(cqr);
2623         }
2624         spin_lock(&block->queue_lock);
2625         /* Get new request from the block device request queue */
2626         __dasd_process_request_queue(block);
2627         /* Now check if the head of the ccw queue needs to be started. */
2628         __dasd_block_start_head(block);
2629         spin_unlock(&block->queue_lock);
2630         spin_unlock_irq(&block->request_queue_lock);
2631         dasd_put_device(block->base);
2632 }
2633
2634 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2635 {
2636         wake_up(&dasd_flush_wq);
2637 }
2638
2639 /*
2640  * Go through all request on the dasd_block request queue, cancel them
2641  * on the respective dasd_device, and return them to the generic
2642  * block layer.
2643  */
2644 static int dasd_flush_block_queue(struct dasd_block *block)
2645 {
2646         struct dasd_ccw_req *cqr, *n;
2647         int rc, i;
2648         struct list_head flush_queue;
2649
2650         INIT_LIST_HEAD(&flush_queue);
2651         spin_lock_bh(&block->queue_lock);
2652         rc = 0;
2653 restart:
2654         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2655                 /* if this request currently owned by a dasd_device cancel it */
2656                 if (cqr->status >= DASD_CQR_QUEUED)
2657                         rc = dasd_cancel_req(cqr);
2658                 if (rc < 0)
2659                         break;
2660                 /* Rechain request (including erp chain) so it won't be
2661                  * touched by the dasd_block_tasklet anymore.
2662                  * Replace the callback so we notice when the request
2663                  * is returned from the dasd_device layer.
2664                  */
2665                 cqr->callback = _dasd_wake_block_flush_cb;
2666                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2667                         list_move_tail(&cqr->blocklist, &flush_queue);
2668                 if (i > 1)
2669                         /* moved more than one request - need to restart */
2670                         goto restart;
2671         }
2672         spin_unlock_bh(&block->queue_lock);
2673         /* Now call the callback function of flushed requests */
2674 restart_cb:
2675         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2676                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2677                 /* Process finished ERP request. */
2678                 if (cqr->refers) {
2679                         spin_lock_bh(&block->queue_lock);
2680                         __dasd_process_erp(block->base, cqr);
2681                         spin_unlock_bh(&block->queue_lock);
2682                         /* restart list_for_xx loop since dasd_process_erp
2683                          * might remove multiple elements */
2684                         goto restart_cb;
2685                 }
2686                 /* call the callback function */
2687                 spin_lock_irq(&block->request_queue_lock);
2688                 cqr->endclk = get_clock();
2689                 list_del_init(&cqr->blocklist);
2690                 __dasd_cleanup_cqr(cqr);
2691                 spin_unlock_irq(&block->request_queue_lock);
2692         }
2693         return rc;
2694 }
2695
2696 /*
2697  * Schedules a call to dasd_tasklet over the device tasklet.
2698  */
2699 void dasd_schedule_block_bh(struct dasd_block *block)
2700 {
2701         /* Protect against rescheduling. */
2702         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2703                 return;
2704         /* life cycle of block is bound to it's base device */
2705         dasd_get_device(block->base);
2706         tasklet_hi_schedule(&block->tasklet);
2707 }
2708
2709
2710 /*
2711  * SECTION: external block device operations
2712  * (request queue handling, open, release, etc.)
2713  */
2714
2715 /*
2716  * Dasd request queue function. Called from ll_rw_blk.c
2717  */
2718 static void do_dasd_request(struct request_queue *queue)
2719 {
2720         struct dasd_block *block;
2721
2722         block = queue->queuedata;
2723         spin_lock(&block->queue_lock);
2724         /* Get new request from the block device request queue */
2725         __dasd_process_request_queue(block);
2726         /* Now check if the head of the ccw queue needs to be started. */
2727         __dasd_block_start_head(block);
2728         spin_unlock(&block->queue_lock);
2729 }
2730
2731 /*
2732  * Allocate and initialize request queue and default I/O scheduler.
2733  */
2734 static int dasd_alloc_queue(struct dasd_block *block)
2735 {
2736         int rc;
2737
2738         block->request_queue = blk_init_queue(do_dasd_request,
2739                                                &block->request_queue_lock);
2740         if (block->request_queue == NULL)
2741                 return -ENOMEM;
2742
2743         block->request_queue->queuedata = block;
2744
2745         elevator_exit(block->request_queue->elevator);
2746         block->request_queue->elevator = NULL;
2747         rc = elevator_init(block->request_queue, "deadline");
2748         if (rc) {
2749                 blk_cleanup_queue(block->request_queue);
2750                 return rc;
2751         }
2752         return 0;
2753 }
2754
2755 /*
2756  * Allocate and initialize request queue.
2757  */
2758 static void dasd_setup_queue(struct dasd_block *block)
2759 {
2760         int max;
2761
2762         if (block->base->features & DASD_FEATURE_USERAW) {
2763                 /*
2764                  * the max_blocks value for raw_track access is 256
2765                  * it is higher than the native ECKD value because we
2766                  * only need one ccw per track
2767                  * so the max_hw_sectors are
2768                  * 2048 x 512B = 1024kB = 16 tracks
2769                  */
2770                 max = 2048;
2771         } else {
2772                 max = block->base->discipline->max_blocks << block->s2b_shift;
2773         }
2774         blk_queue_logical_block_size(block->request_queue,
2775                                      block->bp_block);
2776         blk_queue_max_hw_sectors(block->request_queue, max);
2777         blk_queue_max_segments(block->request_queue, -1L);
2778         /* with page sized segments we can translate each segement into
2779          * one idaw/tidaw
2780          */
2781         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
2782         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
2783 }
2784
2785 /*
2786  * Deactivate and free request queue.
2787  */
2788 static void dasd_free_queue(struct dasd_block *block)
2789 {
2790         if (block->request_queue) {
2791                 blk_cleanup_queue(block->request_queue);
2792                 block->request_queue = NULL;
2793         }
2794 }
2795
2796 /*
2797  * Flush request on the request queue.
2798  */
2799 static void dasd_flush_request_queue(struct dasd_block *block)
2800 {
2801         struct request *req;
2802
2803         if (!block->request_queue)
2804                 return;
2805
2806         spin_lock_irq(&block->request_queue_lock);
2807         while ((req = blk_fetch_request(block->request_queue)))
2808                 __blk_end_request_all(req, -EIO);
2809         spin_unlock_irq(&block->request_queue_lock);
2810 }
2811
2812 static int dasd_open(struct block_device *bdev, fmode_t mode)
2813 {
2814         struct dasd_device *base;
2815         int rc;
2816
2817         base = dasd_device_from_gendisk(bdev->bd_disk);
2818         if (!base)
2819                 return -ENODEV;
2820
2821         atomic_inc(&base->block->open_count);
2822         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
2823                 rc = -ENODEV;
2824                 goto unlock;
2825         }
2826
2827         if (!try_module_get(base->discipline->owner)) {
2828                 rc = -EINVAL;
2829                 goto unlock;
2830         }
2831
2832         if (dasd_probeonly) {
2833                 dev_info(&base->cdev->dev,
2834                          "Accessing the DASD failed because it is in "
2835                          "probeonly mode\n");
2836                 rc = -EPERM;
2837                 goto out;
2838         }
2839
2840         if (base->state <= DASD_STATE_BASIC) {
2841                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
2842                               " Cannot open unrecognized device");
2843                 rc = -ENODEV;
2844                 goto out;
2845         }
2846
2847         if ((mode & FMODE_WRITE) &&
2848             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
2849              (base->features & DASD_FEATURE_READONLY))) {
2850                 rc = -EROFS;
2851                 goto out;
2852         }
2853
2854         dasd_put_device(base);
2855         return 0;
2856
2857 out:
2858         module_put(base->discipline->owner);
2859 unlock:
2860         atomic_dec(&base->block->open_count);
2861         dasd_put_device(base);
2862         return rc;
2863 }
2864
2865 static int dasd_release(struct gendisk *disk, fmode_t mode)
2866 {
2867         struct dasd_device *base;
2868
2869         base = dasd_device_from_gendisk(disk);
2870         if (!base)
2871                 return -ENODEV;
2872
2873         atomic_dec(&base->block->open_count);
2874         module_put(base->discipline->owner);
2875         dasd_put_device(base);
2876         return 0;
2877 }
2878
2879 /*
2880  * Return disk geometry.
2881  */
2882 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2883 {
2884         struct dasd_device *base;
2885
2886         base = dasd_device_from_gendisk(bdev->bd_disk);
2887         if (!base)
2888                 return -ENODEV;
2889
2890         if (!base->discipline ||
2891             !base->discipline->fill_geometry) {
2892                 dasd_put_device(base);
2893                 return -EINVAL;
2894         }
2895         base->discipline->fill_geometry(base->block, geo);
2896         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
2897         dasd_put_device(base);
2898         return 0;
2899 }
2900
2901 const struct block_device_operations
2902 dasd_device_operations = {
2903         .owner          = THIS_MODULE,
2904         .open           = dasd_open,
2905         .release        = dasd_release,
2906         .ioctl          = dasd_ioctl,
2907         .compat_ioctl   = dasd_ioctl,
2908         .getgeo         = dasd_getgeo,
2909 };
2910
2911 /*******************************************************************************
2912  * end of block device operations
2913  */
2914
2915 static void
2916 dasd_exit(void)
2917 {
2918 #ifdef CONFIG_PROC_FS
2919         dasd_proc_exit();
2920 #endif
2921         dasd_eer_exit();
2922         if (dasd_page_cache != NULL) {
2923                 kmem_cache_destroy(dasd_page_cache);
2924                 dasd_page_cache = NULL;
2925         }
2926         dasd_gendisk_exit();
2927         dasd_devmap_exit();
2928         if (dasd_debug_area != NULL) {
2929                 debug_unregister(dasd_debug_area);
2930                 dasd_debug_area = NULL;
2931         }
2932         dasd_statistics_removeroot();
2933 }
2934
2935 /*
2936  * SECTION: common functions for ccw_driver use
2937  */
2938
2939 /*
2940  * Is the device read-only?
2941  * Note that this function does not report the setting of the
2942  * readonly device attribute, but how it is configured in z/VM.
2943  */
2944 int dasd_device_is_ro(struct dasd_device *device)
2945 {
2946         struct ccw_dev_id dev_id;
2947         struct diag210 diag_data;
2948         int rc;
2949
2950         if (!MACHINE_IS_VM)
2951                 return 0;
2952         ccw_device_get_id(device->cdev, &dev_id);
2953         memset(&diag_data, 0, sizeof(diag_data));
2954         diag_data.vrdcdvno = dev_id.devno;
2955         diag_data.vrdclen = sizeof(diag_data);
2956         rc = diag210(&diag_data);
2957         if (rc == 0 || rc == 2) {
2958                 return diag_data.vrdcvfla & 0x80;
2959         } else {
2960                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
2961                           dev_id.devno, rc);
2962                 return 0;
2963         }
2964 }
2965 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
2966
2967 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
2968 {
2969         struct ccw_device *cdev = data;
2970         int ret;
2971
2972         ret = ccw_device_set_online(cdev);
2973         if (ret)
2974                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
2975                            dev_name(&cdev->dev), ret);
2976 }
2977
2978 /*
2979  * Initial attempt at a probe function. this can be simplified once
2980  * the other detection code is gone.
2981  */
2982 int dasd_generic_probe(struct ccw_device *cdev,
2983                        struct dasd_discipline *discipline)
2984 {
2985         int ret;
2986
2987         ret = dasd_add_sysfs_files(cdev);
2988         if (ret) {
2989                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
2990                                 "dasd_generic_probe: could not add "
2991                                 "sysfs entries");
2992                 return ret;
2993         }
2994         cdev->handler = &dasd_int_handler;
2995
2996         /*
2997          * Automatically online either all dasd devices (dasd_autodetect)
2998          * or all devices specified with dasd= parameters during
2999          * initial probe.
3000          */
3001         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3002             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3003                 async_schedule(dasd_generic_auto_online, cdev);
3004         return 0;
3005 }
3006
3007 /*
3008  * This will one day be called from a global not_oper handler.
3009  * It is also used by driver_unregister during module unload.
3010  */
3011 void dasd_generic_remove(struct ccw_device *cdev)
3012 {
3013         struct dasd_device *device;
3014         struct dasd_block *block;
3015
3016         cdev->handler = NULL;
3017
3018         dasd_remove_sysfs_files(cdev);
3019         device = dasd_device_from_cdev(cdev);
3020         if (IS_ERR(device))
3021                 return;
3022         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3023                 /* Already doing offline processing */
3024                 dasd_put_device(device);
3025                 return;
3026         }
3027         /*
3028          * This device is removed unconditionally. Set offline
3029          * flag to prevent dasd_open from opening it while it is
3030          * no quite down yet.
3031          */
3032         dasd_set_target_state(device, DASD_STATE_NEW);
3033         /* dasd_delete_device destroys the device reference. */
3034         block = device->block;
3035         dasd_delete_device(device);
3036         /*
3037          * life cycle of block is bound to device, so delete it after
3038          * device was safely removed
3039          */
3040         if (block)
3041                 dasd_free_block(block);
3042 }
3043
3044 /*
3045  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3046  * the device is detected for the first time and is supposed to be used
3047  * or the user has started activation through sysfs.
3048  */
3049 int dasd_generic_set_online(struct ccw_device *cdev,
3050                             struct dasd_discipline *base_discipline)
3051 {
3052         struct dasd_discipline *discipline;
3053         struct dasd_device *device;
3054         int rc;
3055
3056         /* first online clears initial online feature flag */
3057         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3058         device = dasd_create_device(cdev);
3059         if (IS_ERR(device))
3060                 return PTR_ERR(device);
3061
3062         discipline = base_discipline;
3063         if (device->features & DASD_FEATURE_USEDIAG) {
3064                 if (!dasd_diag_discipline_pointer) {
3065                         pr_warning("%s Setting the DASD online failed because "
3066                                    "of missing DIAG discipline\n",
3067                                    dev_name(&cdev->dev));
3068                         dasd_delete_device(device);
3069                         return -ENODEV;
3070                 }
3071                 discipline = dasd_diag_discipline_pointer;
3072         }
3073         if (!try_module_get(base_discipline->owner)) {
3074                 dasd_delete_device(device);
3075                 return -EINVAL;
3076         }
3077         if (!try_module_get(discipline->owner)) {
3078                 module_put(base_discipline->owner);
3079                 dasd_delete_device(device);
3080                 return -EINVAL;
3081         }
3082         device->base_discipline = base_discipline;
3083         device->discipline = discipline;
3084
3085         /* check_device will allocate block device if necessary */
3086         rc = discipline->check_device(device);
3087         if (rc) {
3088                 pr_warning("%s Setting the DASD online with discipline %s "
3089                            "failed with rc=%i\n",
3090                            dev_name(&cdev->dev), discipline->name, rc);
3091                 module_put(discipline->owner);
3092                 module_put(base_discipline->owner);
3093                 dasd_delete_device(device);
3094                 return rc;
3095         }
3096
3097         dasd_set_target_state(device, DASD_STATE_ONLINE);
3098         if (device->state <= DASD_STATE_KNOWN) {
3099                 pr_warning("%s Setting the DASD online failed because of a "
3100                            "missing discipline\n", dev_name(&cdev->dev));
3101                 rc = -ENODEV;
3102                 dasd_set_target_state(device, DASD_STATE_NEW);
3103                 if (device->block)
3104                         dasd_free_block(device->block);
3105                 dasd_delete_device(device);
3106         } else
3107                 pr_debug("dasd_generic device %s found\n",
3108                                 dev_name(&cdev->dev));
3109
3110         wait_event(dasd_init_waitq, _wait_for_device(device));
3111
3112         dasd_put_device(device);
3113         return rc;
3114 }
3115
3116 int dasd_generic_set_offline(struct ccw_device *cdev)
3117 {
3118         struct dasd_device *device;
3119         struct dasd_block *block;
3120         int max_count, open_count;
3121
3122         device = dasd_device_from_cdev(cdev);
3123         if (IS_ERR(device))
3124                 return PTR_ERR(device);
3125         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3126                 /* Already doing offline processing */
3127                 dasd_put_device(device);
3128                 return 0;
3129         }
3130         /*
3131          * We must make sure that this device is currently not in use.
3132          * The open_count is increased for every opener, that includes
3133          * the blkdev_get in dasd_scan_partitions. We are only interested
3134          * in the other openers.
3135          */
3136         if (device->block) {
3137                 max_count = device->block->bdev ? 0 : -1;
3138                 open_count = atomic_read(&device->block->open_count);
3139                 if (open_count > max_count) {
3140                         if (open_count > 0)
3141                                 pr_warning("%s: The DASD cannot be set offline "
3142                                            "with open count %i\n",
3143                                            dev_name(&cdev->dev), open_count);
3144                         else
3145                                 pr_warning("%s: The DASD cannot be set offline "
3146                                            "while it is in use\n",
3147                                            dev_name(&cdev->dev));
3148                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3149                         dasd_put_device(device);
3150                         return -EBUSY;
3151                 }
3152         }
3153         dasd_set_target_state(device, DASD_STATE_NEW);
3154         /* dasd_delete_device destroys the device reference. */
3155         block = device->block;
3156         dasd_delete_device(device);
3157         /*
3158          * life cycle of block is bound to device, so delete it after
3159          * device was safely removed
3160          */
3161         if (block)
3162                 dasd_free_block(block);
3163         return 0;
3164 }
3165
3166 int dasd_generic_last_path_gone(struct dasd_device *device)
3167 {
3168         struct dasd_ccw_req *cqr;
3169
3170         dev_warn(&device->cdev->dev, "No operational channel path is left "
3171                  "for the device\n");
3172         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3173         /* First of all call extended error reporting. */
3174         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3175
3176         if (device->state < DASD_STATE_BASIC)
3177                 return 0;
3178         /* Device is active. We want to keep it. */
3179         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3180                 if ((cqr->status == DASD_CQR_IN_IO) ||
3181                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3182                         cqr->status = DASD_CQR_QUEUED;
3183                         cqr->retries++;
3184                 }
3185         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3186         dasd_device_clear_timer(device);
3187         dasd_schedule_device_bh(device);
3188         return 1;
3189 }
3190 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3191
3192 int dasd_generic_path_operational(struct dasd_device *device)
3193 {
3194         dev_info(&device->cdev->dev, "A channel path to the device has become "
3195                  "operational\n");
3196         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3197         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3198         if (device->stopped & DASD_UNRESUMED_PM) {
3199                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3200                 dasd_restore_device(device);
3201                 return 1;
3202         }
3203         dasd_schedule_device_bh(device);
3204         if (device->block)
3205                 dasd_schedule_block_bh(device->block);
3206         return 1;
3207 }
3208 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3209
3210 int dasd_generic_notify(struct ccw_device *cdev, int event)
3211 {
3212         struct dasd_device *device;
3213         int ret;
3214
3215         device = dasd_device_from_cdev_locked(cdev);
3216         if (IS_ERR(device))
3217                 return 0;
3218         ret = 0;
3219         switch (event) {
3220         case CIO_GONE:
3221         case CIO_BOXED:
3222         case CIO_NO_PATH:
3223                 device->path_data.opm = 0;
3224                 device->path_data.ppm = 0;
3225                 device->path_data.npm = 0;
3226                 ret = dasd_generic_last_path_gone(device);
3227                 break;
3228         case CIO_OPER:
3229                 ret = 1;
3230                 if (device->path_data.opm)
3231                         ret = dasd_generic_path_operational(device);
3232                 break;
3233         }
3234         dasd_put_device(device);
3235         return ret;
3236 }
3237
3238 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3239 {
3240         int chp;
3241         __u8 oldopm, eventlpm;
3242         struct dasd_device *device;
3243
3244         device = dasd_device_from_cdev_locked(cdev);
3245         if (IS_ERR(device))
3246                 return;
3247         for (chp = 0; chp < 8; chp++) {
3248                 eventlpm = 0x80 >> chp;
3249                 if (path_event[chp] & PE_PATH_GONE) {
3250                         oldopm = device->path_data.opm;
3251                         device->path_data.opm &= ~eventlpm;
3252                         device->path_data.ppm &= ~eventlpm;
3253                         device->path_data.npm &= ~eventlpm;
3254                         if (oldopm && !device->path_data.opm)
3255                                 dasd_generic_last_path_gone(device);
3256                 }
3257                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3258                         device->path_data.opm &= ~eventlpm;
3259                         device->path_data.ppm &= ~eventlpm;
3260                         device->path_data.npm &= ~eventlpm;
3261                         device->path_data.tbvpm |= eventlpm;
3262                         dasd_schedule_device_bh(device);
3263                 }
3264         }
3265         dasd_put_device(device);
3266 }
3267 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3268
3269 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3270 {
3271         if (!device->path_data.opm && lpm) {
3272                 device->path_data.opm = lpm;
3273                 dasd_generic_path_operational(device);
3274         } else
3275                 device->path_data.opm |= lpm;
3276         return 0;
3277 }
3278 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3279
3280
3281 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3282 {
3283         struct dasd_ccw_req *cqr, *n;
3284         int rc;
3285         struct list_head freeze_queue;
3286         struct dasd_device *device = dasd_device_from_cdev(cdev);
3287
3288         if (IS_ERR(device))
3289                 return PTR_ERR(device);
3290
3291         /* mark device as suspended */
3292         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3293
3294         if (device->discipline->freeze)
3295                 rc = device->discipline->freeze(device);
3296
3297         /* disallow new I/O  */
3298         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3299         /* clear active requests */
3300         INIT_LIST_HEAD(&freeze_queue);
3301         spin_lock_irq(get_ccwdev_lock(cdev));
3302         rc = 0;
3303         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3304                 /* Check status and move request to flush_queue */
3305                 if (cqr->status == DASD_CQR_IN_IO) {
3306                         rc = device->discipline->term_IO(cqr);
3307                         if (rc) {
3308                                 /* unable to terminate requeust */
3309                                 dev_err(&device->cdev->dev,
3310                                         "Unable to terminate request %p "
3311                                         "on suspend\n", cqr);
3312                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3313                                 dasd_put_device(device);
3314                                 return rc;
3315                         }
3316                 }
3317                 list_move_tail(&cqr->devlist, &freeze_queue);
3318         }
3319
3320         spin_unlock_irq(get_ccwdev_lock(cdev));
3321
3322         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3323                 wait_event(dasd_flush_wq,
3324                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3325                 if (cqr->status == DASD_CQR_CLEARED)
3326                         cqr->status = DASD_CQR_QUEUED;
3327         }
3328         /* move freeze_queue to start of the ccw_queue */
3329         spin_lock_irq(get_ccwdev_lock(cdev));
3330         list_splice_tail(&freeze_queue, &device->ccw_queue);
3331         spin_unlock_irq(get_ccwdev_lock(cdev));
3332
3333         dasd_put_device(device);
3334         return rc;
3335 }
3336 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3337
3338 int dasd_generic_restore_device(struct ccw_device *cdev)
3339 {
3340         struct dasd_device *device = dasd_device_from_cdev(cdev);
3341         int rc = 0;
3342
3343         if (IS_ERR(device))
3344                 return PTR_ERR(device);
3345
3346         /* allow new IO again */
3347         dasd_device_remove_stop_bits(device,
3348                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3349
3350         dasd_schedule_device_bh(device);
3351
3352         /*
3353          * call discipline restore function
3354          * if device is stopped do nothing e.g. for disconnected devices
3355          */
3356         if (device->discipline->restore && !(device->stopped))
3357                 rc = device->discipline->restore(device);
3358         if (rc || device->stopped)
3359                 /*
3360                  * if the resume failed for the DASD we put it in
3361                  * an UNRESUMED stop state
3362                  */
3363                 device->stopped |= DASD_UNRESUMED_PM;
3364
3365         if (device->block)
3366                 dasd_schedule_block_bh(device->block);
3367
3368         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3369         dasd_put_device(device);
3370         return 0;
3371 }
3372 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3373
3374 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3375                                                    void *rdc_buffer,
3376                                                    int rdc_buffer_size,
3377                                                    int magic)
3378 {
3379         struct dasd_ccw_req *cqr;
3380         struct ccw1 *ccw;
3381         unsigned long *idaw;
3382
3383         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3384
3385         if (IS_ERR(cqr)) {
3386                 /* internal error 13 - Allocating the RDC request failed*/
3387                 dev_err(&device->cdev->dev,
3388                          "An error occurred in the DASD device driver, "
3389                          "reason=%s\n", "13");
3390                 return cqr;
3391         }
3392
3393         ccw = cqr->cpaddr;
3394         ccw->cmd_code = CCW_CMD_RDC;
3395         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3396                 idaw = (unsigned long *) (cqr->data);
3397                 ccw->cda = (__u32)(addr_t) idaw;
3398                 ccw->flags = CCW_FLAG_IDA;
3399                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3400         } else {
3401                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3402                 ccw->flags = 0;
3403         }
3404
3405         ccw->count = rdc_buffer_size;
3406         cqr->startdev = device;
3407         cqr->memdev = device;
3408         cqr->expires = 10*HZ;
3409         cqr->retries = 256;
3410         cqr->buildclk = get_clock();
3411         cqr->status = DASD_CQR_FILLED;
3412         return cqr;
3413 }
3414
3415
3416 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3417                                 void *rdc_buffer, int rdc_buffer_size)
3418 {
3419         int ret;
3420         struct dasd_ccw_req *cqr;
3421
3422         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3423                                      magic);
3424         if (IS_ERR(cqr))
3425                 return PTR_ERR(cqr);
3426
3427         ret = dasd_sleep_on(cqr);
3428         dasd_sfree_request(cqr, cqr->memdev);
3429         return ret;
3430 }
3431 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3432
3433 /*
3434  *   In command mode and transport mode we need to look for sense
3435  *   data in different places. The sense data itself is allways
3436  *   an array of 32 bytes, so we can unify the sense data access
3437  *   for both modes.
3438  */
3439 char *dasd_get_sense(struct irb *irb)
3440 {
3441         struct tsb *tsb = NULL;
3442         char *sense = NULL;
3443
3444         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3445                 if (irb->scsw.tm.tcw)
3446                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3447                                           irb->scsw.tm.tcw);
3448                 if (tsb && tsb->length == 64 && tsb->flags)
3449                         switch (tsb->flags & 0x07) {
3450                         case 1: /* tsa_iostat */
3451                                 sense = tsb->tsa.iostat.sense;
3452                                 break;
3453                         case 2: /* tsa_ddpc */
3454                                 sense = tsb->tsa.ddpc.sense;
3455                                 break;
3456                         default:
3457                                 /* currently we don't use interrogate data */
3458                                 break;
3459                         }
3460         } else if (irb->esw.esw0.erw.cons) {
3461                 sense = irb->ecw;
3462         }
3463         return sense;
3464 }
3465 EXPORT_SYMBOL_GPL(dasd_get_sense);
3466
3467 static int __init dasd_init(void)
3468 {
3469         int rc;
3470
3471         init_waitqueue_head(&dasd_init_waitq);
3472         init_waitqueue_head(&dasd_flush_wq);
3473         init_waitqueue_head(&generic_waitq);
3474
3475         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3476         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3477         if (dasd_debug_area == NULL) {
3478                 rc = -ENOMEM;
3479                 goto failed;
3480         }
3481         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3482         debug_set_level(dasd_debug_area, DBF_WARNING);
3483
3484         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3485
3486         dasd_diag_discipline_pointer = NULL;
3487
3488         dasd_statistics_createroot();
3489
3490         rc = dasd_devmap_init();
3491         if (rc)
3492                 goto failed;
3493         rc = dasd_gendisk_init();
3494         if (rc)
3495                 goto failed;
3496         rc = dasd_parse();
3497         if (rc)
3498                 goto failed;
3499         rc = dasd_eer_init();
3500         if (rc)
3501                 goto failed;
3502 #ifdef CONFIG_PROC_FS
3503         rc = dasd_proc_init();
3504         if (rc)
3505                 goto failed;
3506 #endif
3507
3508         return 0;
3509 failed:
3510         pr_info("The DASD device driver could not be initialized\n");
3511         dasd_exit();
3512         return rc;
3513 }
3514
3515 module_init(dasd_init);
3516 module_exit(dasd_exit);
3517
3518 EXPORT_SYMBOL(dasd_debug_area);
3519 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
3520
3521 EXPORT_SYMBOL(dasd_add_request_head);
3522 EXPORT_SYMBOL(dasd_add_request_tail);
3523 EXPORT_SYMBOL(dasd_cancel_req);
3524 EXPORT_SYMBOL(dasd_device_clear_timer);
3525 EXPORT_SYMBOL(dasd_block_clear_timer);
3526 EXPORT_SYMBOL(dasd_enable_device);
3527 EXPORT_SYMBOL(dasd_int_handler);
3528 EXPORT_SYMBOL(dasd_kfree_request);
3529 EXPORT_SYMBOL(dasd_kick_device);
3530 EXPORT_SYMBOL(dasd_kmalloc_request);
3531 EXPORT_SYMBOL(dasd_schedule_device_bh);
3532 EXPORT_SYMBOL(dasd_schedule_block_bh);
3533 EXPORT_SYMBOL(dasd_set_target_state);
3534 EXPORT_SYMBOL(dasd_device_set_timer);
3535 EXPORT_SYMBOL(dasd_block_set_timer);
3536 EXPORT_SYMBOL(dasd_sfree_request);
3537 EXPORT_SYMBOL(dasd_sleep_on);
3538 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
3539 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
3540 EXPORT_SYMBOL(dasd_smalloc_request);
3541 EXPORT_SYMBOL(dasd_start_IO);
3542 EXPORT_SYMBOL(dasd_term_IO);
3543
3544 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3545 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3546 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3547 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3548 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3549 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
3550 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
3551 EXPORT_SYMBOL_GPL(dasd_alloc_block);
3552 EXPORT_SYMBOL_GPL(dasd_free_block);