drivers/s390/block/dasd.c

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