drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kernel_stat.h>
  15 #include <linux/kmod.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/ctype.h>
  19 #include <linux/major.h>
  20 #include <linux/slab.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/hdreg.h>
  23 #include <linux/async.h>
  24 #include <linux/mutex.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/vmalloc.h>
  28
  29 #include <asm/ccwdev.h>
  30 #include <asm/ebcdic.h>
  31 #include <asm/idals.h>
  32 #include <asm/itcw.h>
  33 #include <asm/diag.h>
  34
  35 /* This is ugly... */
  36 #define PRINTK_HEADER "dasd:"
  37
  38 #include "dasd_int.h"
  39 /*
  40  * SECTION: Constant definitions to be used within this file
  41  */
  42 #define DASD_CHANQ_MAX_SIZE 4
  43
  44 #define DASD_SLEEPON_START_TAG  (void *) 1
  45 #define DASD_SLEEPON_END_TAG    (void *) 2
  46
  47 /*
  48  * SECTION: exported variables of dasd.c
  49  */
  50 debug_info_t *dasd_debug_area;
  51 static struct dentry *dasd_debugfs_root_entry;
  52 struct dasd_discipline *dasd_diag_discipline_pointer;
  53 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  54
  55 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  56 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  57                    " Copyright 2000 IBM Corporation");
  58 MODULE_SUPPORTED_DEVICE("dasd");
  59 MODULE_LICENSE("GPL");
  60
  61 /*
  62  * SECTION: prototypes for static functions of dasd.c
  63  */
  64 static int  dasd_alloc_queue(struct dasd_block *);
  65 static void dasd_setup_queue(struct dasd_block *);
  66 static void dasd_free_queue(struct dasd_block *);
  67 static void dasd_flush_request_queue(struct dasd_block *);
  68 static int dasd_flush_block_queue(struct dasd_block *);
  69 static void dasd_device_tasklet(struct dasd_device *);
  70 static void dasd_block_tasklet(struct dasd_block *);
  71 static void do_kick_device(struct work_struct *);
  72 static void do_restore_device(struct work_struct *);
  73 static void do_reload_device(struct work_struct *);
  74 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  75 static void dasd_device_timeout(unsigned long);
  76 static void dasd_block_timeout(unsigned long);
  77 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  78 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  79 static void dasd_profile_exit(struct dasd_profile *);
  80
  81 /*
  82  * SECTION: Operations on the device structure.
  83  */
  84 static wait_queue_head_t dasd_init_waitq;
  85 static wait_queue_head_t dasd_flush_wq;
  86 static wait_queue_head_t generic_waitq;
  87
  88 /*
  89  * Allocate memory for a new device structure.
  90  */
  91 struct dasd_device *dasd_alloc_device(void)
  92 {
  93         struct dasd_device *device;
  94
  95         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  96         if (!device)
  97                 return ERR_PTR(-ENOMEM);
  98
  99         /* Get two pages for normal block device operations. */
 100         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 101         if (!device->ccw_mem) {
 102                 kfree(device);
 103                 return ERR_PTR(-ENOMEM);
 104         }
 105         /* Get one page for error recovery. */
 106         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 107         if (!device->erp_mem) {
 108                 free_pages((unsigned long) device->ccw_mem, 1);
 109                 kfree(device);
 110                 return ERR_PTR(-ENOMEM);
 111         }
 112
 113         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 114         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 115         spin_lock_init(&device->mem_lock);
 116         atomic_set(&device->tasklet_scheduled, 0);
 117         tasklet_init(&device->tasklet,
 118                      (void (*)(unsigned long)) dasd_device_tasklet,
 119                      (unsigned long) device);
 120         INIT_LIST_HEAD(&device->ccw_queue);
 121         init_timer(&device->timer);
 122         device->timer.function = dasd_device_timeout;
 123         device->timer.data = (unsigned long) device;
 124         INIT_WORK(&device->kick_work, do_kick_device);
 125         INIT_WORK(&device->restore_device, do_restore_device);
 126         INIT_WORK(&device->reload_device, do_reload_device);
 127         device->state = DASD_STATE_NEW;
 128         device->target = DASD_STATE_NEW;
 129         mutex_init(&device->state_mutex);
 130         spin_lock_init(&device->profile.lock);
 131         return device;
 132 }
 133
 134 /*
 135  * Free memory of a device structure.
 136  */
 137 void dasd_free_device(struct dasd_device *device)
 138 {
 139         kfree(device->private);
 140         free_page((unsigned long) device->erp_mem);
 141         free_pages((unsigned long) device->ccw_mem, 1);
 142         kfree(device);
 143 }
 144
 145 /*
 146  * Allocate memory for a new device structure.
 147  */
 148 struct dasd_block *dasd_alloc_block(void)
 149 {
 150         struct dasd_block *block;
 151
 152         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 153         if (!block)
 154                 return ERR_PTR(-ENOMEM);
 155         /* open_count = 0 means device online but not in use */
 156         atomic_set(&block->open_count, -1);
 157
 158         spin_lock_init(&block->request_queue_lock);
 159         atomic_set(&block->tasklet_scheduled, 0);
 160         tasklet_init(&block->tasklet,
 161                      (void (*)(unsigned long)) dasd_block_tasklet,
 162                      (unsigned long) block);
 163         INIT_LIST_HEAD(&block->ccw_queue);
 164         spin_lock_init(&block->queue_lock);
 165         init_timer(&block->timer);
 166         block->timer.function = dasd_block_timeout;
 167         block->timer.data = (unsigned long) block;
 168         spin_lock_init(&block->profile.lock);
 169
 170         return block;
 171 }
 172
 173 /*
 174  * Free memory of a device structure.
 175  */
 176 void dasd_free_block(struct dasd_block *block)
 177 {
 178         kfree(block);
 179 }
 180
 181 /*
 182  * Make a new device known to the system.
 183  */
 184 static int dasd_state_new_to_known(struct dasd_device *device)
 185 {
 186         int rc;
 187
 188         /*
 189          * As long as the device is not in state DASD_STATE_NEW we want to
 190          * keep the reference count > 0.
 191          */
 192         dasd_get_device(device);
 193
 194         if (device->block) {
 195                 rc = dasd_alloc_queue(device->block);
 196                 if (rc) {
 197                         dasd_put_device(device);
 198                         return rc;
 199                 }
 200         }
 201         device->state = DASD_STATE_KNOWN;
 202         return 0;
 203 }
 204
 205 /*
 206  * Let the system forget about a device.
 207  */
 208 static int dasd_state_known_to_new(struct dasd_device *device)
 209 {
 210         /* Disable extended error reporting for this device. */
 211         dasd_eer_disable(device);
 212         /* Forget the discipline information. */
 213         if (device->discipline) {
 214                 if (device->discipline->uncheck_device)
 215                         device->discipline->uncheck_device(device);
 216                 module_put(device->discipline->owner);
 217         }
 218         device->discipline = NULL;
 219         if (device->base_discipline)
 220                 module_put(device->base_discipline->owner);
 221         device->base_discipline = NULL;
 222         device->state = DASD_STATE_NEW;
 223
 224         if (device->block)
 225                 dasd_free_queue(device->block);
 226
 227         /* Give up reference we took in dasd_state_new_to_known. */
 228         dasd_put_device(device);
 229         return 0;
 230 }
 231
 232 static struct dentry *dasd_debugfs_setup(const char *name,
 233                                          struct dentry *base_dentry)
 234 {
 235         struct dentry *pde;
 236
 237         if (!base_dentry)
 238                 return NULL;
 239         pde = debugfs_create_dir(name, base_dentry);
 240         if (!pde || IS_ERR(pde))
 241                 return NULL;
 242         return pde;
 243 }
 244
 245 /*
 246  * Request the irq line for the device.
 247  */
 248 static int dasd_state_known_to_basic(struct dasd_device *device)
 249 {
 250         struct dasd_block *block = device->block;
 251         int rc;
 252
 253         /* Allocate and register gendisk structure. */
 254         if (block) {
 255                 rc = dasd_gendisk_alloc(block);
 256                 if (rc)
 257                         return rc;
 258                 block->debugfs_dentry =
 259                         dasd_debugfs_setup(block->gdp->disk_name,
 260                                            dasd_debugfs_root_entry);
 261                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 262                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 263                         dasd_profile_on(&device->block->profile);
 264         }
 265         device->debugfs_dentry =
 266                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 267                                    dasd_debugfs_root_entry);
 268         dasd_profile_init(&device->profile, device->debugfs_dentry);
 269
 270         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 271         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 272                                             8 * sizeof(long));
 273         debug_register_view(device->debug_area, &debug_sprintf_view);
 274         debug_set_level(device->debug_area, DBF_WARNING);
 275         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 276
 277         device->state = DASD_STATE_BASIC;
 278         return 0;
 279 }
 280
 281 /*
 282  * Release the irq line for the device. Terminate any running i/o.
 283  */
 284 static int dasd_state_basic_to_known(struct dasd_device *device)
 285 {
 286         int rc;
 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                         return rc;
 340                 }
 341                 dasd_setup_queue(block);
 342                 set_capacity(block->gdp,
 343                              block->blocks << block->s2b_shift);
 344                 device->state = DASD_STATE_READY;
 345                 rc = dasd_scan_partitions(block);
 346                 if (rc)
 347                         device->state = DASD_STATE_BASIC;
 348         } else {
 349                 device->state = DASD_STATE_READY;
 350         }
 351         return rc;
 352 }
 353
 354 /*
 355  * Remove device from block device layer. Destroy dirty buffers.
 356  * Forget format information. Check if the target level is basic
 357  * and if it is create fake disk for formatting.
 358  */
 359 static int dasd_state_ready_to_basic(struct dasd_device *device)
 360 {
 361         int rc;
 362
 363         device->state = DASD_STATE_BASIC;
 364         if (device->block) {
 365                 struct dasd_block *block = device->block;
 366                 rc = dasd_flush_block_queue(block);
 367                 if (rc) {
 368                         device->state = DASD_STATE_READY;
 369                         return rc;
 370                 }
 371                 dasd_flush_request_queue(block);
 372                 dasd_destroy_partitions(block);
 373                 block->blocks = 0;
 374                 block->bp_block = 0;
 375                 block->s2b_shift = 0;
 376         }
 377         return 0;
 378 }
 379
 380 /*
 381  * Back to basic.
 382  */
 383 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 384 {
 385         device->state = DASD_STATE_BASIC;
 386         return 0;
 387 }
 388
 389 /*
 390  * Make the device online and schedule the bottom half to start
 391  * the requeueing of requests from the linux request queue to the
 392  * ccw queue.
 393  */
 394 static int
 395 dasd_state_ready_to_online(struct dasd_device * device)
 396 {
 397         int rc;
 398         struct gendisk *disk;
 399         struct disk_part_iter piter;
 400         struct hd_struct *part;
 401
 402         if (device->discipline->ready_to_online) {
 403                 rc = device->discipline->ready_to_online(device);
 404                 if (rc)
 405                         return rc;
 406         }
 407         device->state = DASD_STATE_ONLINE;
 408         if (device->block) {
 409                 dasd_schedule_block_bh(device->block);
 410                 if ((device->features & DASD_FEATURE_USERAW)) {
 411                         disk = device->block->gdp;
 412                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 413                         return 0;
 414                 }
 415                 disk = device->block->bdev->bd_disk;
 416                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 417                 while ((part = disk_part_iter_next(&piter)))
 418                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 419                 disk_part_iter_exit(&piter);
 420         }
 421         return 0;
 422 }
 423
 424 /*
 425  * Stop the requeueing of requests again.
 426  */
 427 static int dasd_state_online_to_ready(struct dasd_device *device)
 428 {
 429         int rc;
 430         struct gendisk *disk;
 431         struct disk_part_iter piter;
 432         struct hd_struct *part;
 433
 434         if (device->discipline->online_to_ready) {
 435                 rc = device->discipline->online_to_ready(device);
 436                 if (rc)
 437                         return rc;
 438         }
 439         device->state = DASD_STATE_READY;
 440         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 441                 disk = device->block->bdev->bd_disk;
 442                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 443                 while ((part = disk_part_iter_next(&piter)))
 444                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 445                 disk_part_iter_exit(&piter);
 446         }
 447         return 0;
 448 }
 449
 450 /*
 451  * Device startup state changes.
 452  */
 453 static int dasd_increase_state(struct dasd_device *device)
 454 {
 455         int rc;
 456
 457         rc = 0;
 458         if (device->state == DASD_STATE_NEW &&
 459             device->target >= DASD_STATE_KNOWN)
 460                 rc = dasd_state_new_to_known(device);
 461
 462         if (!rc &&
 463             device->state == DASD_STATE_KNOWN &&
 464             device->target >= DASD_STATE_BASIC)
 465                 rc = dasd_state_known_to_basic(device);
 466
 467         if (!rc &&
 468             device->state == DASD_STATE_BASIC &&
 469             device->target >= DASD_STATE_READY)
 470                 rc = dasd_state_basic_to_ready(device);
 471
 472         if (!rc &&
 473             device->state == DASD_STATE_UNFMT &&
 474             device->target > DASD_STATE_UNFMT)
 475                 rc = -EPERM;
 476
 477         if (!rc &&
 478             device->state == DASD_STATE_READY &&
 479             device->target >= DASD_STATE_ONLINE)
 480                 rc = dasd_state_ready_to_online(device);
 481
 482         return rc;
 483 }
 484
 485 /*
 486  * Device shutdown state changes.
 487  */
 488 static int dasd_decrease_state(struct dasd_device *device)
 489 {
 490         int rc;
 491
 492         rc = 0;
 493         if (device->state == DASD_STATE_ONLINE &&
 494             device->target <= DASD_STATE_READY)
 495                 rc = dasd_state_online_to_ready(device);
 496
 497         if (!rc &&
 498             device->state == DASD_STATE_READY &&
 499             device->target <= DASD_STATE_BASIC)
 500                 rc = dasd_state_ready_to_basic(device);
 501
 502         if (!rc &&
 503             device->state == DASD_STATE_UNFMT &&
 504             device->target <= DASD_STATE_BASIC)
 505                 rc = dasd_state_unfmt_to_basic(device);
 506
 507         if (!rc &&
 508             device->state == DASD_STATE_BASIC &&
 509             device->target <= DASD_STATE_KNOWN)
 510                 rc = dasd_state_basic_to_known(device);
 511
 512         if (!rc &&
 513             device->state == DASD_STATE_KNOWN &&
 514             device->target <= DASD_STATE_NEW)
 515                 rc = dasd_state_known_to_new(device);
 516
 517         return rc;
 518 }
 519
 520 /*
 521  * This is the main startup/shutdown routine.
 522  */
 523 static void dasd_change_state(struct dasd_device *device)
 524 {
 525         int rc;
 526
 527         if (device->state == device->target)
 528                 /* Already where we want to go today... */
 529                 return;
 530         if (device->state < device->target)
 531                 rc = dasd_increase_state(device);
 532         else
 533                 rc = dasd_decrease_state(device);
 534         if (rc == -EAGAIN)
 535                 return;
 536         if (rc)
 537                 device->target = device->state;
 538
 539         if (device->state == device->target)
 540                 wake_up(&dasd_init_waitq);
 541
 542         /* let user-space know that the device status changed */
 543         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 544 }
 545
 546 /*
 547  * Kick starter for devices that did not complete the startup/shutdown
 548  * procedure or were sleeping because of a pending state.
 549  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 550  * event daemon.
 551  */
 552 static void do_kick_device(struct work_struct *work)
 553 {
 554         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 555         mutex_lock(&device->state_mutex);
 556         dasd_change_state(device);
 557         mutex_unlock(&device->state_mutex);
 558         dasd_schedule_device_bh(device);
 559         dasd_put_device(device);
 560 }
 561
 562 void dasd_kick_device(struct dasd_device *device)
 563 {
 564         dasd_get_device(device);
 565         /* queue call to dasd_kick_device to the kernel event daemon. */
 566         schedule_work(&device->kick_work);
 567 }
 568
 569 /*
 570  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 571  * event daemon.
 572  */
 573 static void do_reload_device(struct work_struct *work)
 574 {
 575         struct dasd_device *device = container_of(work, struct dasd_device,
 576                                                   reload_device);
 577         device->discipline->reload(device);
 578         dasd_put_device(device);
 579 }
 580
 581 void dasd_reload_device(struct dasd_device *device)
 582 {
 583         dasd_get_device(device);
 584         /* queue call to dasd_reload_device to the kernel event daemon. */
 585         schedule_work(&device->reload_device);
 586 }
 587 EXPORT_SYMBOL(dasd_reload_device);
 588
 589 /*
 590  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 591  * event daemon.
 592  */
 593 static void do_restore_device(struct work_struct *work)
 594 {
 595         struct dasd_device *device = container_of(work, struct dasd_device,
 596                                                   restore_device);
 597         device->cdev->drv->restore(device->cdev);
 598         dasd_put_device(device);
 599 }
 600
 601 void dasd_restore_device(struct dasd_device *device)
 602 {
 603         dasd_get_device(device);
 604         /* queue call to dasd_restore_device to the kernel event daemon. */
 605         schedule_work(&device->restore_device);
 606 }
 607
 608 /*
 609  * Set the target state for a device and starts the state change.
 610  */
 611 void dasd_set_target_state(struct dasd_device *device, int target)
 612 {
 613         dasd_get_device(device);
 614         mutex_lock(&device->state_mutex);
 615         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 616         if (dasd_probeonly && target > DASD_STATE_READY)
 617                 target = DASD_STATE_READY;
 618         if (device->target != target) {
 619                 if (device->state == target)
 620                         wake_up(&dasd_init_waitq);
 621                 device->target = target;
 622         }
 623         if (device->state != device->target)
 624                 dasd_change_state(device);
 625         mutex_unlock(&device->state_mutex);
 626         dasd_put_device(device);
 627 }
 628
 629 /*
 630  * Enable devices with device numbers in [from..to].
 631  */
 632 static inline int _wait_for_device(struct dasd_device *device)
 633 {
 634         return (device->state == device->target);
 635 }
 636
 637 void dasd_enable_device(struct dasd_device *device)
 638 {
 639         dasd_set_target_state(device, DASD_STATE_ONLINE);
 640         if (device->state <= DASD_STATE_KNOWN)
 641                 /* No discipline for device found. */
 642                 dasd_set_target_state(device, DASD_STATE_NEW);
 643         /* Now wait for the devices to come up. */
 644         wait_event(dasd_init_waitq, _wait_for_device(device));
 645 }
 646
 647 /*
 648  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 649  */
 650
 651 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 652
 653 #ifdef CONFIG_DASD_PROFILE
 654 struct dasd_profile_info dasd_global_profile_data;
 655 static struct dentry *dasd_global_profile_dentry;
 656 static struct dentry *dasd_debugfs_global_entry;
 657
 658 /*
 659  * Add profiling information for cqr before execution.
 660  */
 661 static void dasd_profile_start(struct dasd_block *block,
 662                                struct dasd_ccw_req *cqr,
 663                                struct request *req)
 664 {
 665         struct list_head *l;
 666         unsigned int counter;
 667         struct dasd_device *device;
 668
 669         /* count the length of the chanq for statistics */
 670         counter = 0;
 671         if (dasd_global_profile_level || block->profile.data)
 672                 list_for_each(l, &block->ccw_queue)
 673                         if (++counter >= 31)
 674                                 break;
 675
 676         if (dasd_global_profile_level) {
 677                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 678                 if (rq_data_dir(req) == READ)
 679                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 680         }
 681
 682         spin_lock(&block->profile.lock);
 683         if (block->profile.data)
 684                 block->profile.data->dasd_io_nr_req[counter]++;
 685                 if (rq_data_dir(req) == READ)
 686                         block->profile.data->dasd_read_nr_req[counter]++;
 687         spin_unlock(&block->profile.lock);
 688
 689         /*
 690          * We count the request for the start device, even though it may run on
 691          * some other device due to error recovery. This way we make sure that
 692          * we count each request only once.
 693          */
 694         device = cqr->startdev;
 695         if (device->profile.data) {
 696                 counter = 1; /* request is not yet queued on the start device */
 697                 list_for_each(l, &device->ccw_queue)
 698                         if (++counter >= 31)
 699                                 break;
 700         }
 701         spin_lock(&device->profile.lock);
 702         if (device->profile.data) {
 703                 device->profile.data->dasd_io_nr_req[counter]++;
 704                 if (rq_data_dir(req) == READ)
 705                         device->profile.data->dasd_read_nr_req[counter]++;
 706         }
 707         spin_unlock(&device->profile.lock);
 708 }
 709
 710 /*
 711  * Add profiling information for cqr after execution.
 712  */
 713
 714 #define dasd_profile_counter(value, index)                         \
 715 {                                                                  \
 716         for (index = 0; index < 31 && value >> (2+index); index++) \
 717                 ;                                                  \
 718 }
 719
 720 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 721                                       int is_alias,
 722                                       int is_tpm,
 723                                       int is_read,
 724                                       long sectors,
 725                                       int sectors_ind,
 726                                       int tottime_ind,
 727                                       int tottimeps_ind,
 728                                       int strtime_ind,
 729                                       int irqtime_ind,
 730                                       int irqtimeps_ind,
 731                                       int endtime_ind)
 732 {
 733         /* in case of an overflow, reset the whole profile */
 734         if (data->dasd_io_reqs == UINT_MAX) {
 735                         memset(data, 0, sizeof(*data));
 736                         getnstimeofday(&data->starttod);
 737         }
 738         data->dasd_io_reqs++;
 739         data->dasd_io_sects += sectors;
 740         if (is_alias)
 741                 data->dasd_io_alias++;
 742         if (is_tpm)
 743                 data->dasd_io_tpm++;
 744
 745         data->dasd_io_secs[sectors_ind]++;
 746         data->dasd_io_times[tottime_ind]++;
 747         data->dasd_io_timps[tottimeps_ind]++;
 748         data->dasd_io_time1[strtime_ind]++;
 749         data->dasd_io_time2[irqtime_ind]++;
 750         data->dasd_io_time2ps[irqtimeps_ind]++;
 751         data->dasd_io_time3[endtime_ind]++;
 752
 753         if (is_read) {
 754                 data->dasd_read_reqs++;
 755                 data->dasd_read_sects += sectors;
 756                 if (is_alias)
 757                         data->dasd_read_alias++;
 758                 if (is_tpm)
 759                         data->dasd_read_tpm++;
 760                 data->dasd_read_secs[sectors_ind]++;
 761                 data->dasd_read_times[tottime_ind]++;
 762                 data->dasd_read_time1[strtime_ind]++;
 763                 data->dasd_read_time2[irqtime_ind]++;
 764                 data->dasd_read_time3[endtime_ind]++;
 765         }
 766 }
 767
 768 static void dasd_profile_end(struct dasd_block *block,
 769                              struct dasd_ccw_req *cqr,
 770                              struct request *req)
 771 {
 772         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 773         long tottimeps, sectors;
 774         struct dasd_device *device;
 775         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 776         int irqtime_ind, irqtimeps_ind, endtime_ind;
 777
 778         device = cqr->startdev;
 779         if (!(dasd_global_profile_level ||
 780               block->profile.data ||
 781               device->profile.data))
 782                 return;
 783
 784         sectors = blk_rq_sectors(req);
 785         if (!cqr->buildclk || !cqr->startclk ||
 786             !cqr->stopclk || !cqr->endclk ||
 787             !sectors)
 788                 return;
 789
 790         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 791         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 792         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 793         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 794         tottimeps = tottime / sectors;
 795
 796         dasd_profile_counter(sectors, sectors_ind);
 797         dasd_profile_counter(tottime, tottime_ind);
 798         dasd_profile_counter(tottimeps, tottimeps_ind);
 799         dasd_profile_counter(strtime, strtime_ind);
 800         dasd_profile_counter(irqtime, irqtime_ind);
 801         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 802         dasd_profile_counter(endtime, endtime_ind);
 803
 804         if (dasd_global_profile_level) {
 805                 dasd_profile_end_add_data(&dasd_global_profile_data,
 806                                           cqr->startdev != block->base,
 807                                           cqr->cpmode == 1,
 808                                           rq_data_dir(req) == READ,
 809                                           sectors, sectors_ind, tottime_ind,
 810                                           tottimeps_ind, strtime_ind,
 811                                           irqtime_ind, irqtimeps_ind,
 812                                           endtime_ind);
 813         }
 814
 815         spin_lock(&block->profile.lock);
 816         if (block->profile.data)
 817                 dasd_profile_end_add_data(block->profile.data,
 818                                           cqr->startdev != block->base,
 819                                           cqr->cpmode == 1,
 820                                           rq_data_dir(req) == READ,
 821                                           sectors, sectors_ind, tottime_ind,
 822                                           tottimeps_ind, strtime_ind,
 823                                           irqtime_ind, irqtimeps_ind,
 824                                           endtime_ind);
 825         spin_unlock(&block->profile.lock);
 826
 827         spin_lock(&device->profile.lock);
 828         if (device->profile.data)
 829                 dasd_profile_end_add_data(device->profile.data,
 830                                           cqr->startdev != block->base,
 831                                           cqr->cpmode == 1,
 832                                           rq_data_dir(req) == READ,
 833                                           sectors, sectors_ind, tottime_ind,
 834                                           tottimeps_ind, strtime_ind,
 835                                           irqtime_ind, irqtimeps_ind,
 836                                           endtime_ind);
 837         spin_unlock(&device->profile.lock);
 838 }
 839
 840 void dasd_profile_reset(struct dasd_profile *profile)
 841 {
 842         struct dasd_profile_info *data;
 843
 844         spin_lock_bh(&profile->lock);
 845         data = profile->data;
 846         if (!data) {
 847                 spin_unlock_bh(&profile->lock);
 848                 return;
 849         }
 850         memset(data, 0, sizeof(*data));
 851         getnstimeofday(&data->starttod);
 852         spin_unlock_bh(&profile->lock);
 853 }
 854
 855 void dasd_global_profile_reset(void)
 856 {
 857         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 858         getnstimeofday(&dasd_global_profile_data.starttod);
 859 }
 860
 861 int dasd_profile_on(struct dasd_profile *profile)
 862 {
 863         struct dasd_profile_info *data;
 864
 865         data = kzalloc(sizeof(*data), GFP_KERNEL);
 866         if (!data)
 867                 return -ENOMEM;
 868         spin_lock_bh(&profile->lock);
 869         if (profile->data) {
 870                 spin_unlock_bh(&profile->lock);
 871                 kfree(data);
 872                 return 0;
 873         }
 874         getnstimeofday(&data->starttod);
 875         profile->data = data;
 876         spin_unlock_bh(&profile->lock);
 877         return 0;
 878 }
 879
 880 void dasd_profile_off(struct dasd_profile *profile)
 881 {
 882         spin_lock_bh(&profile->lock);
 883         kfree(profile->data);
 884         profile->data = NULL;
 885         spin_unlock_bh(&profile->lock);
 886 }
 887
 888 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 889 {
 890         char *buffer;
 891
 892         buffer = vmalloc(user_len + 1);
 893         if (buffer == NULL)
 894                 return ERR_PTR(-ENOMEM);
 895         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 896                 vfree(buffer);
 897                 return ERR_PTR(-EFAULT);
 898         }
 899         /* got the string, now strip linefeed. */
 900         if (buffer[user_len - 1] == '\n')
 901                 buffer[user_len - 1] = 0;
 902         else
 903                 buffer[user_len] = 0;
 904         return buffer;
 905 }
 906
 907 static ssize_t dasd_stats_write(struct file *file,
 908                                 const char __user *user_buf,
 909                                 size_t user_len, loff_t *pos)
 910 {
 911         char *buffer, *str;
 912         int rc;
 913         struct seq_file *m = (struct seq_file *)file->private_data;
 914         struct dasd_profile *prof = m->private;
 915
 916         if (user_len > 65536)
 917                 user_len = 65536;
 918         buffer = dasd_get_user_string(user_buf, user_len);
 919         if (IS_ERR(buffer))
 920                 return PTR_ERR(buffer);
 921
 922         str = skip_spaces(buffer);
 923         rc = user_len;
 924         if (strncmp(str, "reset", 5) == 0) {
 925                 dasd_profile_reset(prof);
 926         } else if (strncmp(str, "on", 2) == 0) {
 927                 rc = dasd_profile_on(prof);
 928                 if (!rc)
 929                         rc = user_len;
 930         } else if (strncmp(str, "off", 3) == 0) {
 931                 dasd_profile_off(prof);
 932         } else
 933                 rc = -EINVAL;
 934         vfree(buffer);
 935         return rc;
 936 }
 937
 938 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 939 {
 940         int i;
 941
 942         for (i = 0; i < 32; i++)
 943                 seq_printf(m, "%u ", array[i]);
 944         seq_putc(m, '\n');
 945 }
 946
 947 static void dasd_stats_seq_print(struct seq_file *m,
 948                                  struct dasd_profile_info *data)
 949 {
 950         seq_printf(m, "start_time %ld.%09ld\n",
 951                    data->starttod.tv_sec, data->starttod.tv_nsec);
 952         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 953         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 954         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 955         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 956         seq_printf(m, "histogram_sectors ");
 957         dasd_stats_array(m, data->dasd_io_secs);
 958         seq_printf(m, "histogram_io_times ");
 959         dasd_stats_array(m, data->dasd_io_times);
 960         seq_printf(m, "histogram_io_times_weighted ");
 961         dasd_stats_array(m, data->dasd_io_timps);
 962         seq_printf(m, "histogram_time_build_to_ssch ");
 963         dasd_stats_array(m, data->dasd_io_time1);
 964         seq_printf(m, "histogram_time_ssch_to_irq ");
 965         dasd_stats_array(m, data->dasd_io_time2);
 966         seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
 967         dasd_stats_array(m, data->dasd_io_time2ps);
 968         seq_printf(m, "histogram_time_irq_to_end ");
 969         dasd_stats_array(m, data->dasd_io_time3);
 970         seq_printf(m, "histogram_ccw_queue_length ");
 971         dasd_stats_array(m, data->dasd_io_nr_req);
 972         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 973         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 974         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 975         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 976         seq_printf(m, "histogram_read_sectors ");
 977         dasd_stats_array(m, data->dasd_read_secs);
 978         seq_printf(m, "histogram_read_times ");
 979         dasd_stats_array(m, data->dasd_read_times);
 980         seq_printf(m, "histogram_read_time_build_to_ssch ");
 981         dasd_stats_array(m, data->dasd_read_time1);
 982         seq_printf(m, "histogram_read_time_ssch_to_irq ");
 983         dasd_stats_array(m, data->dasd_read_time2);
 984         seq_printf(m, "histogram_read_time_irq_to_end ");
 985         dasd_stats_array(m, data->dasd_read_time3);
 986         seq_printf(m, "histogram_read_ccw_queue_length ");
 987         dasd_stats_array(m, data->dasd_read_nr_req);
 988 }
 989
 990 static int dasd_stats_show(struct seq_file *m, void *v)
 991 {
 992         struct dasd_profile *profile;
 993         struct dasd_profile_info *data;
 994
 995         profile = m->private;
 996         spin_lock_bh(&profile->lock);
 997         data = profile->data;
 998         if (!data) {
 999                 spin_unlock_bh(&profile->lock);
1000                 seq_printf(m, "disabled\n");
1001                 return 0;
1002         }
1003         dasd_stats_seq_print(m, data);
1004         spin_unlock_bh(&profile->lock);
1005         return 0;
1006 }
1007
1008 static int dasd_stats_open(struct inode *inode, struct file *file)
1009 {
1010         struct dasd_profile *profile = inode->i_private;
1011         return single_open(file, dasd_stats_show, profile);
1012 }
1013
1014 static const struct file_operations dasd_stats_raw_fops = {
1015         .owner          = THIS_MODULE,
1016         .open           = dasd_stats_open,
1017         .read           = seq_read,
1018         .llseek         = seq_lseek,
1019         .release        = single_release,
1020         .write          = dasd_stats_write,
1021 };
1022
1023 static ssize_t dasd_stats_global_write(struct file *file,
1024                                        const char __user *user_buf,
1025                                        size_t user_len, loff_t *pos)
1026 {
1027         char *buffer, *str;
1028         ssize_t rc;
1029
1030         if (user_len > 65536)
1031                 user_len = 65536;
1032         buffer = dasd_get_user_string(user_buf, user_len);
1033         if (IS_ERR(buffer))
1034                 return PTR_ERR(buffer);
1035         str = skip_spaces(buffer);
1036         rc = user_len;
1037         if (strncmp(str, "reset", 5) == 0) {
1038                 dasd_global_profile_reset();
1039         } else if (strncmp(str, "on", 2) == 0) {
1040                 dasd_global_profile_reset();
1041                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1042         } else if (strncmp(str, "off", 3) == 0) {
1043                 dasd_global_profile_level = DASD_PROFILE_OFF;
1044         } else
1045                 rc = -EINVAL;
1046         vfree(buffer);
1047         return rc;
1048 }
1049
1050 static int dasd_stats_global_show(struct seq_file *m, void *v)
1051 {
1052         if (!dasd_global_profile_level) {
1053                 seq_printf(m, "disabled\n");
1054                 return 0;
1055         }
1056         dasd_stats_seq_print(m, &dasd_global_profile_data);
1057         return 0;
1058 }
1059
1060 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1061 {
1062         return single_open(file, dasd_stats_global_show, NULL);
1063 }
1064
1065 static const struct file_operations dasd_stats_global_fops = {
1066         .owner          = THIS_MODULE,
1067         .open           = dasd_stats_global_open,
1068         .read           = seq_read,
1069         .llseek         = seq_lseek,
1070         .release        = single_release,
1071         .write          = dasd_stats_global_write,
1072 };
1073
1074 static void dasd_profile_init(struct dasd_profile *profile,
1075                               struct dentry *base_dentry)
1076 {
1077         mode_t mode;
1078         struct dentry *pde;
1079
1080         if (!base_dentry)
1081                 return;
1082         profile->dentry = NULL;
1083         profile->data = NULL;
1084         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1085         pde = debugfs_create_file("statistics", mode, base_dentry,
1086                                   profile, &dasd_stats_raw_fops);
1087         if (pde && !IS_ERR(pde))
1088                 profile->dentry = pde;
1089         return;
1090 }
1091
1092 static void dasd_profile_exit(struct dasd_profile *profile)
1093 {
1094         dasd_profile_off(profile);
1095         if (profile->dentry) {
1096                 debugfs_remove(profile->dentry);
1097                 profile->dentry = NULL;
1098         }
1099 }
1100
1101 static void dasd_statistics_removeroot(void)
1102 {
1103         dasd_global_profile_level = DASD_PROFILE_OFF;
1104         if (dasd_global_profile_dentry) {
1105                 debugfs_remove(dasd_global_profile_dentry);
1106                 dasd_global_profile_dentry = NULL;
1107         }
1108         if (dasd_debugfs_global_entry)
1109                 debugfs_remove(dasd_debugfs_global_entry);
1110         if (dasd_debugfs_root_entry)
1111                 debugfs_remove(dasd_debugfs_root_entry);
1112 }
1113
1114 static void dasd_statistics_createroot(void)
1115 {
1116         mode_t mode;
1117         struct dentry *pde;
1118
1119         dasd_debugfs_root_entry = NULL;
1120         dasd_debugfs_global_entry = NULL;
1121         dasd_global_profile_dentry = NULL;
1122         pde = debugfs_create_dir("dasd", NULL);
1123         if (!pde || IS_ERR(pde))
1124                 goto error;
1125         dasd_debugfs_root_entry = pde;
1126         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1127         if (!pde || IS_ERR(pde))
1128                 goto error;
1129         dasd_debugfs_global_entry = pde;
1130
1131         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1132         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1133                                   NULL, &dasd_stats_global_fops);
1134         if (!pde || IS_ERR(pde))
1135                 goto error;
1136         dasd_global_profile_dentry = pde;
1137         return;
1138
1139 error:
1140         DBF_EVENT(DBF_ERR, "%s",
1141                   "Creation of the dasd debugfs interface failed");
1142         dasd_statistics_removeroot();
1143         return;
1144 }
1145
1146 #else
1147 #define dasd_profile_start(block, cqr, req) do {} while (0)
1148 #define dasd_profile_end(block, cqr, req) do {} while (0)
1149
1150 static void dasd_statistics_createroot(void)
1151 {
1152         return;
1153 }
1154
1155 static void dasd_statistics_removeroot(void)
1156 {
1157         return;
1158 }
1159
1160 int dasd_stats_generic_show(struct seq_file *m, void *v)
1161 {
1162         seq_printf(m, "Statistics are not activated in this kernel\n");
1163         return 0;
1164 }
1165
1166 static void dasd_profile_init(struct dasd_profile *profile,
1167                               struct dentry *base_dentry)
1168 {
1169         return;
1170 }
1171
1172 static void dasd_profile_exit(struct dasd_profile *profile)
1173 {
1174         return;
1175 }
1176
1177 int dasd_profile_on(struct dasd_profile *profile)
1178 {
1179         return 0;
1180 }
1181
1182 #endif                          /* CONFIG_DASD_PROFILE */
1183
1184 /*
1185  * Allocate memory for a channel program with 'cplength' channel
1186  * command words and 'datasize' additional space. There are two
1187  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1188  * memory and 2) dasd_smalloc_request uses the static ccw memory
1189  * that gets allocated for each device.
1190  */
1191 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1192                                           int datasize,
1193                                           struct dasd_device *device)
1194 {
1195         struct dasd_ccw_req *cqr;
1196
1197         /* Sanity checks */
1198         BUG_ON(datasize > PAGE_SIZE ||
1199              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1200
1201         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1202         if (cqr == NULL)
1203                 return ERR_PTR(-ENOMEM);
1204         cqr->cpaddr = NULL;
1205         if (cplength > 0) {
1206                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1207                                       GFP_ATOMIC | GFP_DMA);
1208                 if (cqr->cpaddr == NULL) {
1209                         kfree(cqr);
1210                         return ERR_PTR(-ENOMEM);
1211                 }
1212         }
1213         cqr->data = NULL;
1214         if (datasize > 0) {
1215                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1216                 if (cqr->data == NULL) {
1217                         kfree(cqr->cpaddr);
1218                         kfree(cqr);
1219                         return ERR_PTR(-ENOMEM);
1220                 }
1221         }
1222         cqr->magic =  magic;
1223         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1224         dasd_get_device(device);
1225         return cqr;
1226 }
1227
1228 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1229                                           int datasize,
1230                                           struct dasd_device *device)
1231 {
1232         unsigned long flags;
1233         struct dasd_ccw_req *cqr;
1234         char *data;
1235         int size;
1236
1237         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1238         if (cplength > 0)
1239                 size += cplength * sizeof(struct ccw1);
1240         if (datasize > 0)
1241                 size += datasize;
1242         spin_lock_irqsave(&device->mem_lock, flags);
1243         cqr = (struct dasd_ccw_req *)
1244                 dasd_alloc_chunk(&device->ccw_chunks, size);
1245         spin_unlock_irqrestore(&device->mem_lock, flags);
1246         if (cqr == NULL)
1247                 return ERR_PTR(-ENOMEM);
1248         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1249         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1250         cqr->cpaddr = NULL;
1251         if (cplength > 0) {
1252                 cqr->cpaddr = (struct ccw1 *) data;
1253                 data += cplength*sizeof(struct ccw1);
1254                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1255         }
1256         cqr->data = NULL;
1257         if (datasize > 0) {
1258                 cqr->data = data;
1259                 memset(cqr->data, 0, datasize);
1260         }
1261         cqr->magic = magic;
1262         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1263         dasd_get_device(device);
1264         return cqr;
1265 }
1266
1267 /*
1268  * Free memory of a channel program. This function needs to free all the
1269  * idal lists that might have been created by dasd_set_cda and the
1270  * struct dasd_ccw_req itself.
1271  */
1272 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1273 {
1274 #ifdef CONFIG_64BIT
1275         struct ccw1 *ccw;
1276
1277         /* Clear any idals used for the request. */
1278         ccw = cqr->cpaddr;
1279         do {
1280                 clear_normalized_cda(ccw);
1281         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1282 #endif
1283         kfree(cqr->cpaddr);
1284         kfree(cqr->data);
1285         kfree(cqr);
1286         dasd_put_device(device);
1287 }
1288
1289 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1290 {
1291         unsigned long flags;
1292
1293         spin_lock_irqsave(&device->mem_lock, flags);
1294         dasd_free_chunk(&device->ccw_chunks, cqr);
1295         spin_unlock_irqrestore(&device->mem_lock, flags);
1296         dasd_put_device(device);
1297 }
1298
1299 /*
1300  * Check discipline magic in cqr.
1301  */
1302 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1303 {
1304         struct dasd_device *device;
1305
1306         if (cqr == NULL)
1307                 return -EINVAL;
1308         device = cqr->startdev;
1309         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1310                 DBF_DEV_EVENT(DBF_WARNING, device,
1311                             " dasd_ccw_req 0x%08x magic doesn't match"
1312                             " discipline 0x%08x",
1313                             cqr->magic,
1314                             *(unsigned int *) device->discipline->name);
1315                 return -EINVAL;
1316         }
1317         return 0;
1318 }
1319
1320 /*
1321  * Terminate the current i/o and set the request to clear_pending.
1322  * Timer keeps device runnig.
1323  * ccw_device_clear can fail if the i/o subsystem
1324  * is in a bad mood.
1325  */
1326 int dasd_term_IO(struct dasd_ccw_req *cqr)
1327 {
1328         struct dasd_device *device;
1329         int retries, rc;
1330         char errorstring[ERRORLENGTH];
1331
1332         /* Check the cqr */
1333         rc = dasd_check_cqr(cqr);
1334         if (rc)
1335                 return rc;
1336         retries = 0;
1337         device = (struct dasd_device *) cqr->startdev;
1338         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1339                 rc = ccw_device_clear(device->cdev, (long) cqr);
1340                 switch (rc) {
1341                 case 0: /* termination successful */
1342                         cqr->status = DASD_CQR_CLEAR_PENDING;
1343                         cqr->stopclk = get_clock();
1344                         cqr->starttime = 0;
1345                         DBF_DEV_EVENT(DBF_DEBUG, device,
1346                                       "terminate cqr %p successful",
1347                                       cqr);
1348                         break;
1349                 case -ENODEV:
1350                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1351                                       "device gone, retry");
1352                         break;
1353                 case -EIO:
1354                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1355                                       "I/O error, retry");
1356                         break;
1357                 case -EINVAL:
1358                 case -EBUSY:
1359                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1360                                       "device busy, retry later");
1361                         break;
1362                 default:
1363                         /* internal error 10 - unknown rc*/
1364                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1365                         dev_err(&device->cdev->dev, "An error occurred in the "
1366                                 "DASD device driver, reason=%s\n", errorstring);
1367                         BUG();
1368                         break;
1369                 }
1370                 retries++;
1371         }
1372         dasd_schedule_device_bh(device);
1373         return rc;
1374 }
1375
1376 /*
1377  * Start the i/o. This start_IO can fail if the channel is really busy.
1378  * In that case set up a timer to start the request later.
1379  */
1380 int dasd_start_IO(struct dasd_ccw_req *cqr)
1381 {
1382         struct dasd_device *device;
1383         int rc;
1384         char errorstring[ERRORLENGTH];
1385
1386         /* Check the cqr */
1387         rc = dasd_check_cqr(cqr);
1388         if (rc) {
1389                 cqr->intrc = rc;
1390                 return rc;
1391         }
1392         device = (struct dasd_device *) cqr->startdev;
1393         if (((cqr->block &&
1394               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1395              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1396             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1397                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1398                               "because of stolen lock", cqr);
1399                 cqr->status = DASD_CQR_ERROR;
1400                 cqr->intrc = -EPERM;
1401                 return -EPERM;
1402         }
1403         if (cqr->retries < 0) {
1404                 /* internal error 14 - start_IO run out of retries */
1405                 sprintf(errorstring, "14 %p", cqr);
1406                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1407                         "device driver, reason=%s\n", errorstring);
1408                 cqr->status = DASD_CQR_ERROR;
1409                 return -EIO;
1410         }
1411         cqr->startclk = get_clock();
1412         cqr->starttime = jiffies;
1413         cqr->retries--;
1414         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1415                 cqr->lpm &= device->path_data.opm;
1416                 if (!cqr->lpm)
1417                         cqr->lpm = device->path_data.opm;
1418         }
1419         if (cqr->cpmode == 1) {
1420                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1421                                          (long) cqr, cqr->lpm);
1422         } else {
1423                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1424                                       (long) cqr, cqr->lpm, 0);
1425         }
1426         switch (rc) {
1427         case 0:
1428                 cqr->status = DASD_CQR_IN_IO;
1429                 break;
1430         case -EBUSY:
1431                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1432                               "start_IO: device busy, retry later");
1433                 break;
1434         case -ETIMEDOUT:
1435                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1436                               "start_IO: request timeout, retry later");
1437                 break;
1438         case -EACCES:
1439                 /* -EACCES indicates that the request used only a subset of the
1440                  * available paths and all these paths are gone. If the lpm of
1441                  * this request was only a subset of the opm (e.g. the ppm) then
1442                  * we just do a retry with all available paths.
1443                  * If we already use the full opm, something is amiss, and we
1444                  * need a full path verification.
1445                  */
1446                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1447                         DBF_DEV_EVENT(DBF_WARNING, device,
1448                                       "start_IO: selected paths gone (%x)",
1449                                       cqr->lpm);
1450                 } else if (cqr->lpm != device->path_data.opm) {
1451                         cqr->lpm = device->path_data.opm;
1452                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1453                                       "start_IO: selected paths gone,"
1454                                       " retry on all paths");
1455                 } else {
1456                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1457                                       "start_IO: all paths in opm gone,"
1458                                       " do path verification");
1459                         dasd_generic_last_path_gone(device);
1460                         device->path_data.opm = 0;
1461                         device->path_data.ppm = 0;
1462                         device->path_data.npm = 0;
1463                         device->path_data.tbvpm =
1464                                 ccw_device_get_path_mask(device->cdev);
1465                 }
1466                 break;
1467         case -ENODEV:
1468                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1469                               "start_IO: -ENODEV device gone, retry");
1470                 break;
1471         case -EIO:
1472                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1473                               "start_IO: -EIO device gone, retry");
1474                 break;
1475         case -EINVAL:
1476                 /* most likely caused in power management context */
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: -EINVAL device currently "
1479                               "not accessible");
1480                 break;
1481         default:
1482                 /* internal error 11 - unknown rc */
1483                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1484                 dev_err(&device->cdev->dev,
1485                         "An error occurred in the DASD device driver, "
1486                         "reason=%s\n", errorstring);
1487                 BUG();
1488                 break;
1489         }
1490         cqr->intrc = rc;
1491         return rc;
1492 }
1493
1494 /*
1495  * Timeout function for dasd devices. This is used for different purposes
1496  *  1) missing interrupt handler for normal operation
1497  *  2) delayed start of request where start_IO failed with -EBUSY
1498  *  3) timeout for missing state change interrupts
1499  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1500  * DASD_CQR_QUEUED for 2) and 3).
1501  */
1502 static void dasd_device_timeout(unsigned long ptr)
1503 {
1504         unsigned long flags;
1505         struct dasd_device *device;
1506
1507         device = (struct dasd_device *) ptr;
1508         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1509         /* re-activate request queue */
1510         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1511         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1512         dasd_schedule_device_bh(device);
1513 }
1514
1515 /*
1516  * Setup timeout for a device in jiffies.
1517  */
1518 void dasd_device_set_timer(struct dasd_device *device, int expires)
1519 {
1520         if (expires == 0)
1521                 del_timer(&device->timer);
1522         else
1523                 mod_timer(&device->timer, jiffies + expires);
1524 }
1525
1526 /*
1527  * Clear timeout for a device.
1528  */
1529 void dasd_device_clear_timer(struct dasd_device *device)
1530 {
1531         del_timer(&device->timer);
1532 }
1533
1534 static void dasd_handle_killed_request(struct ccw_device *cdev,
1535                                        unsigned long intparm)
1536 {
1537         struct dasd_ccw_req *cqr;
1538         struct dasd_device *device;
1539
1540         if (!intparm)
1541                 return;
1542         cqr = (struct dasd_ccw_req *) intparm;
1543         if (cqr->status != DASD_CQR_IN_IO) {
1544                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1545                                 "invalid status in handle_killed_request: "
1546                                 "%02x", cqr->status);
1547                 return;
1548         }
1549
1550         device = dasd_device_from_cdev_locked(cdev);
1551         if (IS_ERR(device)) {
1552                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1553                                 "unable to get device from cdev");
1554                 return;
1555         }
1556
1557         if (!cqr->startdev ||
1558             device != cqr->startdev ||
1559             strncmp(cqr->startdev->discipline->ebcname,
1560                     (char *) &cqr->magic, 4)) {
1561                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1562                                 "invalid device in request");
1563                 dasd_put_device(device);
1564                 return;
1565         }
1566
1567         /* Schedule request to be retried. */
1568         cqr->status = DASD_CQR_QUEUED;
1569
1570         dasd_device_clear_timer(device);
1571         dasd_schedule_device_bh(device);
1572         dasd_put_device(device);
1573 }
1574
1575 void dasd_generic_handle_state_change(struct dasd_device *device)
1576 {
1577         /* First of all start sense subsystem status request. */
1578         dasd_eer_snss(device);
1579
1580         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1581         dasd_schedule_device_bh(device);
1582         if (device->block)
1583                 dasd_schedule_block_bh(device->block);
1584 }
1585
1586 /*
1587  * Interrupt handler for "normal" ssch-io based dasd devices.
1588  */
1589 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1590                       struct irb *irb)
1591 {
1592         struct dasd_ccw_req *cqr, *next;
1593         struct dasd_device *device;
1594         unsigned long long now;
1595         int expires;
1596
1597         kstat_cpu(smp_processor_id()).irqs[IOINT_DAS]++;
1598         if (IS_ERR(irb)) {
1599                 switch (PTR_ERR(irb)) {
1600                 case -EIO:
1601                         break;
1602                 case -ETIMEDOUT:
1603                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1604                                         "request timed out\n", __func__);
1605                         break;
1606                 default:
1607                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1608                                         "unknown error %ld\n", __func__,
1609                                         PTR_ERR(irb));
1610                 }
1611                 dasd_handle_killed_request(cdev, intparm);
1612                 return;
1613         }
1614
1615         now = get_clock();
1616         cqr = (struct dasd_ccw_req *) intparm;
1617         /* check for conditions that should be handled immediately */
1618         if (!cqr ||
1619             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1620               scsw_cstat(&irb->scsw) == 0)) {
1621                 if (cqr)
1622                         memcpy(&cqr->irb, irb, sizeof(*irb));
1623                 device = dasd_device_from_cdev_locked(cdev);
1624                 if (IS_ERR(device))
1625                         return;
1626                 /* ignore unsolicited interrupts for DIAG discipline */
1627                 if (device->discipline == dasd_diag_discipline_pointer) {
1628                         dasd_put_device(device);
1629                         return;
1630                 }
1631                 device->discipline->dump_sense_dbf(device, irb, "int");
1632                 if (device->features & DASD_FEATURE_ERPLOG)
1633                         device->discipline->dump_sense(device, cqr, irb);
1634                 device->discipline->check_for_device_change(device, cqr, irb);
1635                 dasd_put_device(device);
1636         }
1637         if (!cqr)
1638                 return;
1639
1640         device = (struct dasd_device *) cqr->startdev;
1641         if (!device ||
1642             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1643                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1644                                 "invalid device in request");
1645                 return;
1646         }
1647
1648         /* Check for clear pending */
1649         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1650             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1651                 cqr->status = DASD_CQR_CLEARED;
1652                 dasd_device_clear_timer(device);
1653                 wake_up(&dasd_flush_wq);
1654                 dasd_schedule_device_bh(device);
1655                 return;
1656         }
1657
1658         /* check status - the request might have been killed by dyn detach */
1659         if (cqr->status != DASD_CQR_IN_IO) {
1660                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1661                               "status %02x", dev_name(&cdev->dev), cqr->status);
1662                 return;
1663         }
1664
1665         next = NULL;
1666         expires = 0;
1667         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1668             scsw_cstat(&irb->scsw) == 0) {
1669                 /* request was completed successfully */
1670                 cqr->status = DASD_CQR_SUCCESS;
1671                 cqr->stopclk = now;
1672                 /* Start first request on queue if possible -> fast_io. */
1673                 if (cqr->devlist.next != &device->ccw_queue) {
1674                         next = list_entry(cqr->devlist.next,
1675                                           struct dasd_ccw_req, devlist);
1676                 }
1677         } else {  /* error */
1678                 /*
1679                  * If we don't want complex ERP for this request, then just
1680                  * reset this and retry it in the fastpath
1681                  */
1682                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1683                     cqr->retries > 0) {
1684                         if (cqr->lpm == device->path_data.opm)
1685                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1686                                               "default ERP in fastpath "
1687                                               "(%i retries left)",
1688                                               cqr->retries);
1689                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1690                                 cqr->lpm = device->path_data.opm;
1691                         cqr->status = DASD_CQR_QUEUED;
1692                         next = cqr;
1693                 } else
1694                         cqr->status = DASD_CQR_ERROR;
1695         }
1696         if (next && (next->status == DASD_CQR_QUEUED) &&
1697             (!device->stopped)) {
1698                 if (device->discipline->start_IO(next) == 0)
1699                         expires = next->expires;
1700         }
1701         if (expires != 0)
1702                 dasd_device_set_timer(device, expires);
1703         else
1704                 dasd_device_clear_timer(device);
1705         dasd_schedule_device_bh(device);
1706 }
1707
1708 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1709 {
1710         struct dasd_device *device;
1711
1712         device = dasd_device_from_cdev_locked(cdev);
1713
1714         if (IS_ERR(device))
1715                 goto out;
1716         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1717            device->state != device->target ||
1718            !device->discipline->check_for_device_change){
1719                 dasd_put_device(device);
1720                 goto out;
1721         }
1722         if (device->discipline->dump_sense_dbf)
1723                 device->discipline->dump_sense_dbf(device, irb, "uc");
1724         device->discipline->check_for_device_change(device, NULL, irb);
1725         dasd_put_device(device);
1726 out:
1727         return UC_TODO_RETRY;
1728 }
1729 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1730
1731 /*
1732  * If we have an error on a dasd_block layer request then we cancel
1733  * and return all further requests from the same dasd_block as well.
1734  */
1735 static void __dasd_device_recovery(struct dasd_device *device,
1736                                    struct dasd_ccw_req *ref_cqr)
1737 {
1738         struct list_head *l, *n;
1739         struct dasd_ccw_req *cqr;
1740
1741         /*
1742          * only requeue request that came from the dasd_block layer
1743          */
1744         if (!ref_cqr->block)
1745                 return;
1746
1747         list_for_each_safe(l, n, &device->ccw_queue) {
1748                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1749                 if (cqr->status == DASD_CQR_QUEUED &&
1750                     ref_cqr->block == cqr->block) {
1751                         cqr->status = DASD_CQR_CLEARED;
1752                 }
1753         }
1754 };
1755
1756 /*
1757  * Remove those ccw requests from the queue that need to be returned
1758  * to the upper layer.
1759  */
1760 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1761                                             struct list_head *final_queue)
1762 {
1763         struct list_head *l, *n;
1764         struct dasd_ccw_req *cqr;
1765
1766         /* Process request with final status. */
1767         list_for_each_safe(l, n, &device->ccw_queue) {
1768                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1769
1770                 /* Stop list processing at the first non-final request. */
1771                 if (cqr->status == DASD_CQR_QUEUED ||
1772                     cqr->status == DASD_CQR_IN_IO ||
1773                     cqr->status == DASD_CQR_CLEAR_PENDING)
1774                         break;
1775                 if (cqr->status == DASD_CQR_ERROR) {
1776                         __dasd_device_recovery(device, cqr);
1777                 }
1778                 /* Rechain finished requests to final queue */
1779                 list_move_tail(&cqr->devlist, final_queue);
1780         }
1781 }
1782
1783 /*
1784  * the cqrs from the final queue are returned to the upper layer
1785  * by setting a dasd_block state and calling the callback function
1786  */
1787 static void __dasd_device_process_final_queue(struct dasd_device *device,
1788                                               struct list_head *final_queue)
1789 {
1790         struct list_head *l, *n;
1791         struct dasd_ccw_req *cqr;
1792         struct dasd_block *block;
1793         void (*callback)(struct dasd_ccw_req *, void *data);
1794         void *callback_data;
1795         char errorstring[ERRORLENGTH];
1796
1797         list_for_each_safe(l, n, final_queue) {
1798                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1799                 list_del_init(&cqr->devlist);
1800                 block = cqr->block;
1801                 callback = cqr->callback;
1802                 callback_data = cqr->callback_data;
1803                 if (block)
1804                         spin_lock_bh(&block->queue_lock);
1805                 switch (cqr->status) {
1806                 case DASD_CQR_SUCCESS:
1807                         cqr->status = DASD_CQR_DONE;
1808                         break;
1809                 case DASD_CQR_ERROR:
1810                         cqr->status = DASD_CQR_NEED_ERP;
1811                         break;
1812                 case DASD_CQR_CLEARED:
1813                         cqr->status = DASD_CQR_TERMINATED;
1814                         break;
1815                 default:
1816                         /* internal error 12 - wrong cqr status*/
1817                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1818                         dev_err(&device->cdev->dev,
1819                                 "An error occurred in the DASD device driver, "
1820                                 "reason=%s\n", errorstring);
1821                         BUG();
1822                 }
1823                 if (cqr->callback != NULL)
1824                         (callback)(cqr, callback_data);
1825                 if (block)
1826                         spin_unlock_bh(&block->queue_lock);
1827         }
1828 }
1829
1830 /*
1831  * Take a look at the first request on the ccw queue and check
1832  * if it reached its expire time. If so, terminate the IO.
1833  */
1834 static void __dasd_device_check_expire(struct dasd_device *device)
1835 {
1836         struct dasd_ccw_req *cqr;
1837
1838         if (list_empty(&device->ccw_queue))
1839                 return;
1840         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1841         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1842             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1843                 if (device->discipline->term_IO(cqr) != 0) {
1844                         /* Hmpf, try again in 5 sec */
1845                         dev_err(&device->cdev->dev,
1846                                 "cqr %p timed out (%lus) but cannot be "
1847                                 "ended, retrying in 5 s\n",
1848                                 cqr, (cqr->expires/HZ));
1849                         cqr->expires += 5*HZ;
1850                         dasd_device_set_timer(device, 5*HZ);
1851                 } else {
1852                         dev_err(&device->cdev->dev,
1853                                 "cqr %p timed out (%lus), %i retries "
1854                                 "remaining\n", cqr, (cqr->expires/HZ),
1855                                 cqr->retries);
1856                 }
1857         }
1858 }
1859
1860 /*
1861  * Take a look at the first request on the ccw queue and check
1862  * if it needs to be started.
1863  */
1864 static void __dasd_device_start_head(struct dasd_device *device)
1865 {
1866         struct dasd_ccw_req *cqr;
1867         int rc;
1868
1869         if (list_empty(&device->ccw_queue))
1870                 return;
1871         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1872         if (cqr->status != DASD_CQR_QUEUED)
1873                 return;
1874         /* when device is stopped, return request to previous layer
1875          * exception: only the disconnect or unresumed bits are set and the
1876          * cqr is a path verification request
1877          */
1878         if (device->stopped &&
1879             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1880               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1881                 cqr->intrc = -EAGAIN;
1882                 cqr->status = DASD_CQR_CLEARED;
1883                 dasd_schedule_device_bh(device);
1884                 return;
1885         }
1886
1887         rc = device->discipline->start_IO(cqr);
1888         if (rc == 0)
1889                 dasd_device_set_timer(device, cqr->expires);
1890         else if (rc == -EACCES) {
1891                 dasd_schedule_device_bh(device);
1892         } else
1893                 /* Hmpf, try again in 1/2 sec */
1894                 dasd_device_set_timer(device, 50);
1895 }
1896
1897 static void __dasd_device_check_path_events(struct dasd_device *device)
1898 {
1899         int rc;
1900
1901         if (device->path_data.tbvpm) {
1902                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1903                                         DASD_UNRESUMED_PM))
1904                         return;
1905                 rc = device->discipline->verify_path(
1906                         device, device->path_data.tbvpm);
1907                 if (rc)
1908                         dasd_device_set_timer(device, 50);
1909                 else
1910                         device->path_data.tbvpm = 0;
1911         }
1912 };
1913
1914 /*
1915  * Go through all request on the dasd_device request queue,
1916  * terminate them on the cdev if necessary, and return them to the
1917  * submitting layer via callback.
1918  * Note:
1919  * Make sure that all 'submitting layers' still exist when
1920  * this function is called!. In other words, when 'device' is a base
1921  * device then all block layer requests must have been removed before
1922  * via dasd_flush_block_queue.
1923  */
1924 int dasd_flush_device_queue(struct dasd_device *device)
1925 {
1926         struct dasd_ccw_req *cqr, *n;
1927         int rc;
1928         struct list_head flush_queue;
1929
1930         INIT_LIST_HEAD(&flush_queue);
1931         spin_lock_irq(get_ccwdev_lock(device->cdev));
1932         rc = 0;
1933         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1934                 /* Check status and move request to flush_queue */
1935                 switch (cqr->status) {
1936                 case DASD_CQR_IN_IO:
1937                         rc = device->discipline->term_IO(cqr);
1938                         if (rc) {
1939                                 /* unable to terminate requeust */
1940                                 dev_err(&device->cdev->dev,
1941                                         "Flushing the DASD request queue "
1942                                         "failed for request %p\n", cqr);
1943                                 /* stop flush processing */
1944                                 goto finished;
1945                         }
1946                         break;
1947                 case DASD_CQR_QUEUED:
1948                         cqr->stopclk = get_clock();
1949                         cqr->status = DASD_CQR_CLEARED;
1950                         break;
1951                 default: /* no need to modify the others */
1952                         break;
1953                 }
1954                 list_move_tail(&cqr->devlist, &flush_queue);
1955         }
1956 finished:
1957         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1958         /*
1959          * After this point all requests must be in state CLEAR_PENDING,
1960          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1961          * one of the others.
1962          */
1963         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1964                 wait_event(dasd_flush_wq,
1965                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1966         /*
1967          * Now set each request back to TERMINATED, DONE or NEED_ERP
1968          * and call the callback function of flushed requests
1969          */
1970         __dasd_device_process_final_queue(device, &flush_queue);
1971         return rc;
1972 }
1973
1974 /*
1975  * Acquire the device lock and process queues for the device.
1976  */
1977 static void dasd_device_tasklet(struct dasd_device *device)
1978 {
1979         struct list_head final_queue;
1980
1981         atomic_set (&device->tasklet_scheduled, 0);
1982         INIT_LIST_HEAD(&final_queue);
1983         spin_lock_irq(get_ccwdev_lock(device->cdev));
1984         /* Check expire time of first request on the ccw queue. */
1985         __dasd_device_check_expire(device);
1986         /* find final requests on ccw queue */
1987         __dasd_device_process_ccw_queue(device, &final_queue);
1988         __dasd_device_check_path_events(device);
1989         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1990         /* Now call the callback function of requests with final status */
1991         __dasd_device_process_final_queue(device, &final_queue);
1992         spin_lock_irq(get_ccwdev_lock(device->cdev));
1993         /* Now check if the head of the ccw queue needs to be started. */
1994         __dasd_device_start_head(device);
1995         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1996         dasd_put_device(device);
1997 }
1998
1999 /*
2000  * Schedules a call to dasd_tasklet over the device tasklet.
2001  */
2002 void dasd_schedule_device_bh(struct dasd_device *device)
2003 {
2004         /* Protect against rescheduling. */
2005         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2006                 return;
2007         dasd_get_device(device);
2008         tasklet_hi_schedule(&device->tasklet);
2009 }
2010
2011 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2012 {
2013         device->stopped |= bits;
2014 }
2015 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2016
2017 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2018 {
2019         device->stopped &= ~bits;
2020         if (!device->stopped)
2021                 wake_up(&generic_waitq);
2022 }
2023 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2024
2025 /*
2026  * Queue a request to the head of the device ccw_queue.
2027  * Start the I/O if possible.
2028  */
2029 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2030 {
2031         struct dasd_device *device;
2032         unsigned long flags;
2033
2034         device = cqr->startdev;
2035         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2036         cqr->status = DASD_CQR_QUEUED;
2037         list_add(&cqr->devlist, &device->ccw_queue);
2038         /* let the bh start the request to keep them in order */
2039         dasd_schedule_device_bh(device);
2040         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2041 }
2042
2043 /*
2044  * Queue a request to the tail of the device ccw_queue.
2045  * Start the I/O if possible.
2046  */
2047 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2048 {
2049         struct dasd_device *device;
2050         unsigned long flags;
2051
2052         device = cqr->startdev;
2053         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2054         cqr->status = DASD_CQR_QUEUED;
2055         list_add_tail(&cqr->devlist, &device->ccw_queue);
2056         /* let the bh start the request to keep them in order */
2057         dasd_schedule_device_bh(device);
2058         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2059 }
2060
2061 /*
2062  * Wakeup helper for the 'sleep_on' functions.
2063  */
2064 static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2065 {
2066         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2067         cqr->callback_data = DASD_SLEEPON_END_TAG;
2068         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2069         wake_up(&generic_waitq);
2070 }
2071
2072 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2073 {
2074         struct dasd_device *device;
2075         int rc;
2076
2077         device = cqr->startdev;
2078         spin_lock_irq(get_ccwdev_lock(device->cdev));
2079         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2080         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2081         return rc;
2082 }
2083
2084 /*
2085  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2086  */
2087 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2088 {
2089         struct dasd_device *device;
2090         dasd_erp_fn_t erp_fn;
2091
2092         if (cqr->status == DASD_CQR_FILLED)
2093                 return 0;
2094         device = cqr->startdev;
2095         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2096                 if (cqr->status == DASD_CQR_TERMINATED) {
2097                         device->discipline->handle_terminated_request(cqr);
2098                         return 1;
2099                 }
2100                 if (cqr->status == DASD_CQR_NEED_ERP) {
2101                         erp_fn = device->discipline->erp_action(cqr);
2102                         erp_fn(cqr);
2103                         return 1;
2104                 }
2105                 if (cqr->status == DASD_CQR_FAILED)
2106                         dasd_log_sense(cqr, &cqr->irb);
2107                 if (cqr->refers) {
2108                         __dasd_process_erp(device, cqr);
2109                         return 1;
2110                 }
2111         }
2112         return 0;
2113 }
2114
2115 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2116 {
2117         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2118                 if (cqr->refers) /* erp is not done yet */
2119                         return 1;
2120                 return ((cqr->status != DASD_CQR_DONE) &&
2121                         (cqr->status != DASD_CQR_FAILED));
2122         } else
2123                 return (cqr->status == DASD_CQR_FILLED);
2124 }
2125
2126 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2127 {
2128         struct dasd_device *device;
2129         int rc;
2130         struct list_head ccw_queue;
2131         struct dasd_ccw_req *cqr;
2132
2133         INIT_LIST_HEAD(&ccw_queue);
2134         maincqr->status = DASD_CQR_FILLED;
2135         device = maincqr->startdev;
2136         list_add(&maincqr->blocklist, &ccw_queue);
2137         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2138              cqr = list_first_entry(&ccw_queue,
2139                                     struct dasd_ccw_req, blocklist)) {
2140
2141                 if (__dasd_sleep_on_erp(cqr))
2142                         continue;
2143                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2144                         continue;
2145                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2146                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2147                         cqr->status = DASD_CQR_FAILED;
2148                         cqr->intrc = -EPERM;
2149                         continue;
2150                 }
2151                 /* Non-temporary stop condition will trigger fail fast */
2152                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2153                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2154                     (!dasd_eer_enabled(device))) {
2155                         cqr->status = DASD_CQR_FAILED;
2156                         continue;
2157                 }
2158                 /* Don't try to start requests if device is stopped */
2159                 if (interruptible) {
2160                         rc = wait_event_interruptible(
2161                                 generic_waitq, !(device->stopped));
2162                         if (rc == -ERESTARTSYS) {
2163                                 cqr->status = DASD_CQR_FAILED;
2164                                 maincqr->intrc = rc;
2165                                 continue;
2166                         }
2167                 } else
2168                         wait_event(generic_waitq, !(device->stopped));
2169
2170                 cqr->callback = dasd_wakeup_cb;
2171                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2172                 dasd_add_request_tail(cqr);
2173                 if (interruptible) {
2174                         rc = wait_event_interruptible(
2175                                 generic_waitq, _wait_for_wakeup(cqr));
2176                         if (rc == -ERESTARTSYS) {
2177                                 dasd_cancel_req(cqr);
2178                                 /* wait (non-interruptible) for final status */
2179                                 wait_event(generic_waitq,
2180                                            _wait_for_wakeup(cqr));
2181                                 cqr->status = DASD_CQR_FAILED;
2182                                 maincqr->intrc = rc;
2183                                 continue;
2184                         }
2185                 } else
2186                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2187         }
2188
2189         maincqr->endclk = get_clock();
2190         if ((maincqr->status != DASD_CQR_DONE) &&
2191             (maincqr->intrc != -ERESTARTSYS))
2192                 dasd_log_sense(maincqr, &maincqr->irb);
2193         if (maincqr->status == DASD_CQR_DONE)
2194                 rc = 0;
2195         else if (maincqr->intrc)
2196                 rc = maincqr->intrc;
2197         else
2198                 rc = -EIO;
2199         return rc;
2200 }
2201
2202 /*
2203  * Queue a request to the tail of the device ccw_queue and wait for
2204  * it's completion.
2205  */
2206 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2207 {
2208         return _dasd_sleep_on(cqr, 0);
2209 }
2210
2211 /*
2212  * Queue a request to the tail of the device ccw_queue and wait
2213  * interruptible for it's completion.
2214  */
2215 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2216 {
2217         return _dasd_sleep_on(cqr, 1);
2218 }
2219
2220 /*
2221  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2222  * for eckd devices) the currently running request has to be terminated
2223  * and be put back to status queued, before the special request is added
2224  * to the head of the queue. Then the special request is waited on normally.
2225  */
2226 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2227 {
2228         struct dasd_ccw_req *cqr;
2229         int rc;
2230
2231         if (list_empty(&device->ccw_queue))
2232                 return 0;
2233         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2234         rc = device->discipline->term_IO(cqr);
2235         if (!rc)
2236                 /*
2237                  * CQR terminated because a more important request is pending.
2238                  * Undo decreasing of retry counter because this is
2239                  * not an error case.
2240                  */
2241                 cqr->retries++;
2242         return rc;
2243 }
2244
2245 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2246 {
2247         struct dasd_device *device;
2248         int rc;
2249
2250         device = cqr->startdev;
2251         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2252             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2253                 cqr->status = DASD_CQR_FAILED;
2254                 cqr->intrc = -EPERM;
2255                 return -EIO;
2256         }
2257         spin_lock_irq(get_ccwdev_lock(device->cdev));
2258         rc = _dasd_term_running_cqr(device);
2259         if (rc) {
2260                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2261                 return rc;
2262         }
2263         cqr->callback = dasd_wakeup_cb;
2264         cqr->callback_data = DASD_SLEEPON_START_TAG;
2265         cqr->status = DASD_CQR_QUEUED;
2266         list_add(&cqr->devlist, &device->ccw_queue);
2267
2268         /* let the bh start the request to keep them in order */
2269         dasd_schedule_device_bh(device);
2270
2271         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2272
2273         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2274
2275         if (cqr->status == DASD_CQR_DONE)
2276                 rc = 0;
2277         else if (cqr->intrc)
2278                 rc = cqr->intrc;
2279         else
2280                 rc = -EIO;
2281         return rc;
2282 }
2283
2284 /*
2285  * Cancels a request that was started with dasd_sleep_on_req.
2286  * This is useful to timeout requests. The request will be
2287  * terminated if it is currently in i/o.
2288  * Returns 1 if the request has been terminated.
2289  *         0 if there was no need to terminate the request (not started yet)
2290  *         negative error code if termination failed
2291  * Cancellation of a request is an asynchronous operation! The calling
2292  * function has to wait until the request is properly returned via callback.
2293  */
2294 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2295 {
2296         struct dasd_device *device = cqr->startdev;
2297         unsigned long flags;
2298         int rc;
2299
2300         rc = 0;
2301         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2302         switch (cqr->status) {
2303         case DASD_CQR_QUEUED:
2304                 /* request was not started - just set to cleared */
2305                 cqr->status = DASD_CQR_CLEARED;
2306                 break;
2307         case DASD_CQR_IN_IO:
2308                 /* request in IO - terminate IO and release again */
2309                 rc = device->discipline->term_IO(cqr);
2310                 if (rc) {
2311                         dev_err(&device->cdev->dev,
2312                                 "Cancelling request %p failed with rc=%d\n",
2313                                 cqr, rc);
2314                 } else {
2315                         cqr->stopclk = get_clock();
2316                 }
2317                 break;
2318         default: /* already finished or clear pending - do nothing */
2319                 break;
2320         }
2321         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2322         dasd_schedule_device_bh(device);
2323         return rc;
2324 }
2325
2326
2327 /*
2328  * SECTION: Operations of the dasd_block layer.
2329  */
2330
2331 /*
2332  * Timeout function for dasd_block. This is used when the block layer
2333  * is waiting for something that may not come reliably, (e.g. a state
2334  * change interrupt)
2335  */
2336 static void dasd_block_timeout(unsigned long ptr)
2337 {
2338         unsigned long flags;
2339         struct dasd_block *block;
2340
2341         block = (struct dasd_block *) ptr;
2342         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2343         /* re-activate request queue */
2344         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2345         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2346         dasd_schedule_block_bh(block);
2347 }
2348
2349 /*
2350  * Setup timeout for a dasd_block in jiffies.
2351  */
2352 void dasd_block_set_timer(struct dasd_block *block, int expires)
2353 {
2354         if (expires == 0)
2355                 del_timer(&block->timer);
2356         else
2357                 mod_timer(&block->timer, jiffies + expires);
2358 }
2359
2360 /*
2361  * Clear timeout for a dasd_block.
2362  */
2363 void dasd_block_clear_timer(struct dasd_block *block)
2364 {
2365         del_timer(&block->timer);
2366 }
2367
2368 /*
2369  * Process finished error recovery ccw.
2370  */
2371 static void __dasd_process_erp(struct dasd_device *device,
2372                                struct dasd_ccw_req *cqr)
2373 {
2374         dasd_erp_fn_t erp_fn;
2375
2376         if (cqr->status == DASD_CQR_DONE)
2377                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2378         else
2379                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2380         erp_fn = device->discipline->erp_postaction(cqr);
2381         erp_fn(cqr);
2382 }
2383
2384 /*
2385  * Fetch requests from the block device queue.
2386  */
2387 static void __dasd_process_request_queue(struct dasd_block *block)
2388 {
2389         struct request_queue *queue;
2390         struct request *req;
2391         struct dasd_ccw_req *cqr;
2392         struct dasd_device *basedev;
2393         unsigned long flags;
2394         queue = block->request_queue;
2395         basedev = block->base;
2396         /* No queue ? Then there is nothing to do. */
2397         if (queue == NULL)
2398                 return;
2399
2400         /*
2401          * We requeue request from the block device queue to the ccw
2402          * queue only in two states. In state DASD_STATE_READY the
2403          * partition detection is done and we need to requeue requests
2404          * for that. State DASD_STATE_ONLINE is normal block device
2405          * operation.
2406          */
2407         if (basedev->state < DASD_STATE_READY) {
2408                 while ((req = blk_fetch_request(block->request_queue)))
2409                         __blk_end_request_all(req, -EIO);
2410                 return;
2411         }
2412         /* Now we try to fetch requests from the request queue */
2413         while ((req = blk_peek_request(queue))) {
2414                 if (basedev->features & DASD_FEATURE_READONLY &&
2415                     rq_data_dir(req) == WRITE) {
2416                         DBF_DEV_EVENT(DBF_ERR, basedev,
2417                                       "Rejecting write request %p",
2418                                       req);
2419                         blk_start_request(req);
2420                         __blk_end_request_all(req, -EIO);
2421                         continue;
2422                 }
2423                 cqr = basedev->discipline->build_cp(basedev, block, req);
2424                 if (IS_ERR(cqr)) {
2425                         if (PTR_ERR(cqr) == -EBUSY)
2426                                 break;  /* normal end condition */
2427                         if (PTR_ERR(cqr) == -ENOMEM)
2428                                 break;  /* terminate request queue loop */
2429                         if (PTR_ERR(cqr) == -EAGAIN) {
2430                                 /*
2431                                  * The current request cannot be build right
2432                                  * now, we have to try later. If this request
2433                                  * is the head-of-queue we stop the device
2434                                  * for 1/2 second.
2435                                  */
2436                                 if (!list_empty(&block->ccw_queue))
2437                                         break;
2438                                 spin_lock_irqsave(
2439                                         get_ccwdev_lock(basedev->cdev), flags);
2440                                 dasd_device_set_stop_bits(basedev,
2441                                                           DASD_STOPPED_PENDING);
2442                                 spin_unlock_irqrestore(
2443                                         get_ccwdev_lock(basedev->cdev), flags);
2444                                 dasd_block_set_timer(block, HZ/2);
2445                                 break;
2446                         }
2447                         DBF_DEV_EVENT(DBF_ERR, basedev,
2448                                       "CCW creation failed (rc=%ld) "
2449                                       "on request %p",
2450                                       PTR_ERR(cqr), req);
2451                         blk_start_request(req);
2452                         __blk_end_request_all(req, -EIO);
2453                         continue;
2454                 }
2455                 /*
2456                  *  Note: callback is set to dasd_return_cqr_cb in
2457                  * __dasd_block_start_head to cover erp requests as well
2458                  */
2459                 cqr->callback_data = (void *) req;
2460                 cqr->status = DASD_CQR_FILLED;
2461                 blk_start_request(req);
2462                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2463                 dasd_profile_start(block, cqr, req);
2464         }
2465 }
2466
2467 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2468 {
2469         struct request *req;
2470         int status;
2471         int error = 0;
2472
2473         req = (struct request *) cqr->callback_data;
2474         dasd_profile_end(cqr->block, cqr, req);
2475         status = cqr->block->base->discipline->free_cp(cqr, req);
2476         if (status <= 0)
2477                 error = status ? status : -EIO;
2478         __blk_end_request_all(req, error);
2479 }
2480
2481 /*
2482  * Process ccw request queue.
2483  */
2484 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2485                                            struct list_head *final_queue)
2486 {
2487         struct list_head *l, *n;
2488         struct dasd_ccw_req *cqr;
2489         dasd_erp_fn_t erp_fn;
2490         unsigned long flags;
2491         struct dasd_device *base = block->base;
2492
2493 restart:
2494         /* Process request with final status. */
2495         list_for_each_safe(l, n, &block->ccw_queue) {
2496                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2497                 if (cqr->status != DASD_CQR_DONE &&
2498                     cqr->status != DASD_CQR_FAILED &&
2499                     cqr->status != DASD_CQR_NEED_ERP &&
2500                     cqr->status != DASD_CQR_TERMINATED)
2501                         continue;
2502
2503                 if (cqr->status == DASD_CQR_TERMINATED) {
2504                         base->discipline->handle_terminated_request(cqr);
2505                         goto restart;
2506                 }
2507
2508                 /*  Process requests that may be recovered */
2509                 if (cqr->status == DASD_CQR_NEED_ERP) {
2510                         erp_fn = base->discipline->erp_action(cqr);
2511                         if (IS_ERR(erp_fn(cqr)))
2512                                 continue;
2513                         goto restart;
2514                 }
2515
2516                 /* log sense for fatal error */
2517                 if (cqr->status == DASD_CQR_FAILED) {
2518                         dasd_log_sense(cqr, &cqr->irb);
2519                 }
2520
2521                 /* First of all call extended error reporting. */
2522                 if (dasd_eer_enabled(base) &&
2523                     cqr->status == DASD_CQR_FAILED) {
2524                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2525
2526                         /* restart request  */
2527                         cqr->status = DASD_CQR_FILLED;
2528                         cqr->retries = 255;
2529                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2530                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2531                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2532                                                flags);
2533                         goto restart;
2534                 }
2535
2536                 /* Process finished ERP request. */
2537                 if (cqr->refers) {
2538                         __dasd_process_erp(base, cqr);
2539                         goto restart;
2540                 }
2541
2542                 /* Rechain finished requests to final queue */
2543                 cqr->endclk = get_clock();
2544                 list_move_tail(&cqr->blocklist, final_queue);
2545         }
2546 }
2547
2548 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2549 {
2550         dasd_schedule_block_bh(cqr->block);
2551 }
2552
2553 static void __dasd_block_start_head(struct dasd_block *block)
2554 {
2555         struct dasd_ccw_req *cqr;
2556
2557         if (list_empty(&block->ccw_queue))
2558                 return;
2559         /* We allways begin with the first requests on the queue, as some
2560          * of previously started requests have to be enqueued on a
2561          * dasd_device again for error recovery.
2562          */
2563         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2564                 if (cqr->status != DASD_CQR_FILLED)
2565                         continue;
2566                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2567                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2568                         cqr->status = DASD_CQR_FAILED;
2569                         cqr->intrc = -EPERM;
2570                         dasd_schedule_block_bh(block);
2571                         continue;
2572                 }
2573                 /* Non-temporary stop condition will trigger fail fast */
2574                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2575                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2576                     (!dasd_eer_enabled(block->base))) {
2577                         cqr->status = DASD_CQR_FAILED;
2578                         dasd_schedule_block_bh(block);
2579                         continue;
2580                 }
2581                 /* Don't try to start requests if device is stopped */
2582                 if (block->base->stopped)
2583                         return;
2584
2585                 /* just a fail safe check, should not happen */
2586                 if (!cqr->startdev)
2587                         cqr->startdev = block->base;
2588
2589                 /* make sure that the requests we submit find their way back */
2590                 cqr->callback = dasd_return_cqr_cb;
2591
2592                 dasd_add_request_tail(cqr);
2593         }
2594 }
2595
2596 /*
2597  * Central dasd_block layer routine. Takes requests from the generic
2598  * block layer request queue, creates ccw requests, enqueues them on
2599  * a dasd_device and processes ccw requests that have been returned.
2600  */
2601 static void dasd_block_tasklet(struct dasd_block *block)
2602 {
2603         struct list_head final_queue;
2604         struct list_head *l, *n;
2605         struct dasd_ccw_req *cqr;
2606
2607         atomic_set(&block->tasklet_scheduled, 0);
2608         INIT_LIST_HEAD(&final_queue);
2609         spin_lock(&block->queue_lock);
2610         /* Finish off requests on ccw queue */
2611         __dasd_process_block_ccw_queue(block, &final_queue);
2612         spin_unlock(&block->queue_lock);
2613         /* Now call the callback function of requests with final status */
2614         spin_lock_irq(&block->request_queue_lock);
2615         list_for_each_safe(l, n, &final_queue) {
2616                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2617                 list_del_init(&cqr->blocklist);
2618                 __dasd_cleanup_cqr(cqr);
2619         }
2620         spin_lock(&block->queue_lock);
2621         /* Get new request from the block device request queue */
2622         __dasd_process_request_queue(block);
2623         /* Now check if the head of the ccw queue needs to be started. */
2624         __dasd_block_start_head(block);
2625         spin_unlock(&block->queue_lock);
2626         spin_unlock_irq(&block->request_queue_lock);
2627         dasd_put_device(block->base);
2628 }
2629
2630 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2631 {
2632         wake_up(&dasd_flush_wq);
2633 }
2634
2635 /*
2636  * Go through all request on the dasd_block request queue, cancel them
2637  * on the respective dasd_device, and return them to the generic
2638  * block layer.
2639  */
2640 static int dasd_flush_block_queue(struct dasd_block *block)
2641 {
2642         struct dasd_ccw_req *cqr, *n;
2643         int rc, i;
2644         struct list_head flush_queue;
2645
2646         INIT_LIST_HEAD(&flush_queue);
2647         spin_lock_bh(&block->queue_lock);
2648         rc = 0;
2649 restart:
2650         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2651                 /* if this request currently owned by a dasd_device cancel it */
2652                 if (cqr->status >= DASD_CQR_QUEUED)
2653                         rc = dasd_cancel_req(cqr);
2654                 if (rc < 0)
2655                         break;
2656                 /* Rechain request (including erp chain) so it won't be
2657                  * touched by the dasd_block_tasklet anymore.
2658                  * Replace the callback so we notice when the request
2659                  * is returned from the dasd_device layer.
2660                  */
2661                 cqr->callback = _dasd_wake_block_flush_cb;
2662                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2663                         list_move_tail(&cqr->blocklist, &flush_queue);
2664                 if (i > 1)
2665                         /* moved more than one request - need to restart */
2666                         goto restart;
2667         }
2668         spin_unlock_bh(&block->queue_lock);
2669         /* Now call the callback function of flushed requests */
2670 restart_cb:
2671         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2672                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2673                 /* Process finished ERP request. */
2674                 if (cqr->refers) {
2675                         spin_lock_bh(&block->queue_lock);
2676                         __dasd_process_erp(block->base, cqr);
2677                         spin_unlock_bh(&block->queue_lock);
2678                         /* restart list_for_xx loop since dasd_process_erp
2679                          * might remove multiple elements */
2680                         goto restart_cb;
2681                 }
2682                 /* call the callback function */
2683                 spin_lock_irq(&block->request_queue_lock);
2684                 cqr->endclk = get_clock();
2685                 list_del_init(&cqr->blocklist);
2686                 __dasd_cleanup_cqr(cqr);
2687                 spin_unlock_irq(&block->request_queue_lock);
2688         }
2689         return rc;
2690 }
2691
2692 /*
2693  * Schedules a call to dasd_tasklet over the device tasklet.
2694  */
2695 void dasd_schedule_block_bh(struct dasd_block *block)
2696 {
2697         /* Protect against rescheduling. */
2698         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2699                 return;
2700         /* life cycle of block is bound to it's base device */
2701         dasd_get_device(block->base);
2702         tasklet_hi_schedule(&block->tasklet);
2703 }
2704
2705
2706 /*
2707  * SECTION: external block device operations
2708  * (request queue handling, open, release, etc.)
2709  */
2710
2711 /*
2712  * Dasd request queue function. Called from ll_rw_blk.c
2713  */
2714 static void do_dasd_request(struct request_queue *queue)
2715 {
2716         struct dasd_block *block;
2717
2718         block = queue->queuedata;
2719         spin_lock(&block->queue_lock);
2720         /* Get new request from the block device request queue */
2721         __dasd_process_request_queue(block);
2722         /* Now check if the head of the ccw queue needs to be started. */
2723         __dasd_block_start_head(block);
2724         spin_unlock(&block->queue_lock);
2725 }
2726
2727 /*
2728  * Allocate and initialize request queue and default I/O scheduler.
2729  */
2730 static int dasd_alloc_queue(struct dasd_block *block)
2731 {
2732         int rc;
2733
2734         block->request_queue = blk_init_queue(do_dasd_request,
2735                                                &block->request_queue_lock);
2736         if (block->request_queue == NULL)
2737                 return -ENOMEM;
2738
2739         block->request_queue->queuedata = block;
2740
2741         elevator_exit(block->request_queue->elevator);
2742         block->request_queue->elevator = NULL;
2743         rc = elevator_init(block->request_queue, "deadline");
2744         if (rc) {
2745                 blk_cleanup_queue(block->request_queue);
2746                 return rc;
2747         }
2748         return 0;
2749 }
2750
2751 /*
2752  * Allocate and initialize request queue.
2753  */
2754 static void dasd_setup_queue(struct dasd_block *block)
2755 {
2756         int max;
2757
2758         if (block->base->features & DASD_FEATURE_USERAW) {
2759                 /*
2760                  * the max_blocks value for raw_track access is 256
2761                  * it is higher than the native ECKD value because we
2762                  * only need one ccw per track
2763                  * so the max_hw_sectors are
2764                  * 2048 x 512B = 1024kB = 16 tracks
2765                  */
2766                 max = 2048;
2767         } else {
2768                 max = block->base->discipline->max_blocks << block->s2b_shift;
2769         }
2770         blk_queue_logical_block_size(block->request_queue,
2771                                      block->bp_block);
2772         blk_queue_max_hw_sectors(block->request_queue, max);
2773         blk_queue_max_segments(block->request_queue, -1L);
2774         /* with page sized segments we can translate each segement into
2775          * one idaw/tidaw
2776          */
2777         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
2778         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
2779 }
2780
2781 /*
2782  * Deactivate and free request queue.
2783  */
2784 static void dasd_free_queue(struct dasd_block *block)
2785 {
2786         if (block->request_queue) {
2787                 blk_cleanup_queue(block->request_queue);
2788                 block->request_queue = NULL;
2789         }
2790 }
2791
2792 /*
2793  * Flush request on the request queue.
2794  */
2795 static void dasd_flush_request_queue(struct dasd_block *block)
2796 {
2797         struct request *req;
2798
2799         if (!block->request_queue)
2800                 return;
2801
2802         spin_lock_irq(&block->request_queue_lock);
2803         while ((req = blk_fetch_request(block->request_queue)))
2804                 __blk_end_request_all(req, -EIO);
2805         spin_unlock_irq(&block->request_queue_lock);
2806 }
2807
2808 static int dasd_open(struct block_device *bdev, fmode_t mode)
2809 {
2810         struct dasd_device *base;
2811         int rc;
2812
2813         base = dasd_device_from_gendisk(bdev->bd_disk);
2814         if (!base)
2815                 return -ENODEV;
2816
2817         atomic_inc(&base->block->open_count);
2818         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
2819                 rc = -ENODEV;
2820                 goto unlock;
2821         }
2822
2823         if (!try_module_get(base->discipline->owner)) {
2824                 rc = -EINVAL;
2825                 goto unlock;
2826         }
2827
2828         if (dasd_probeonly) {
2829                 dev_info(&base->cdev->dev,
2830                          "Accessing the DASD failed because it is in "
2831                          "probeonly mode\n");
2832                 rc = -EPERM;
2833                 goto out;
2834         }
2835
2836         if (base->state <= DASD_STATE_BASIC) {
2837                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
2838                               " Cannot open unrecognized device");
2839                 rc = -ENODEV;
2840                 goto out;
2841         }
2842
2843         if ((mode & FMODE_WRITE) &&
2844             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
2845              (base->features & DASD_FEATURE_READONLY))) {
2846                 rc = -EROFS;
2847                 goto out;
2848         }
2849
2850         dasd_put_device(base);
2851         return 0;
2852
2853 out:
2854         module_put(base->discipline->owner);
2855 unlock:
2856         atomic_dec(&base->block->open_count);
2857         dasd_put_device(base);
2858         return rc;
2859 }
2860
2861 static int dasd_release(struct gendisk *disk, fmode_t mode)
2862 {
2863         struct dasd_device *base;
2864
2865         base = dasd_device_from_gendisk(disk);
2866         if (!base)
2867                 return -ENODEV;
2868
2869         atomic_dec(&base->block->open_count);
2870         module_put(base->discipline->owner);
2871         dasd_put_device(base);
2872         return 0;
2873 }
2874
2875 /*
2876  * Return disk geometry.
2877  */
2878 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2879 {
2880         struct dasd_device *base;
2881
2882         base = dasd_device_from_gendisk(bdev->bd_disk);
2883         if (!base)
2884                 return -ENODEV;
2885
2886         if (!base->discipline ||
2887             !base->discipline->fill_geometry) {
2888                 dasd_put_device(base);
2889                 return -EINVAL;
2890         }
2891         base->discipline->fill_geometry(base->block, geo);
2892         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
2893         dasd_put_device(base);
2894         return 0;
2895 }
2896
2897 const struct block_device_operations
2898 dasd_device_operations = {
2899         .owner          = THIS_MODULE,
2900         .open           = dasd_open,
2901         .release        = dasd_release,
2902         .ioctl          = dasd_ioctl,
2903         .compat_ioctl   = dasd_ioctl,
2904         .getgeo         = dasd_getgeo,
2905 };
2906
2907 /*******************************************************************************
2908  * end of block device operations
2909  */
2910
2911 static void
2912 dasd_exit(void)
2913 {
2914 #ifdef CONFIG_PROC_FS
2915         dasd_proc_exit();
2916 #endif
2917         dasd_eer_exit();
2918         if (dasd_page_cache != NULL) {
2919                 kmem_cache_destroy(dasd_page_cache);
2920                 dasd_page_cache = NULL;
2921         }
2922         dasd_gendisk_exit();
2923         dasd_devmap_exit();
2924         if (dasd_debug_area != NULL) {
2925                 debug_unregister(dasd_debug_area);
2926                 dasd_debug_area = NULL;
2927         }
2928         dasd_statistics_removeroot();
2929 }
2930
2931 /*
2932  * SECTION: common functions for ccw_driver use
2933  */
2934
2935 /*
2936  * Is the device read-only?
2937  * Note that this function does not report the setting of the
2938  * readonly device attribute, but how it is configured in z/VM.
2939  */
2940 int dasd_device_is_ro(struct dasd_device *device)
2941 {
2942         struct ccw_dev_id dev_id;
2943         struct diag210 diag_data;
2944         int rc;
2945
2946         if (!MACHINE_IS_VM)
2947                 return 0;
2948         ccw_device_get_id(device->cdev, &dev_id);
2949         memset(&diag_data, 0, sizeof(diag_data));
2950         diag_data.vrdcdvno = dev_id.devno;
2951         diag_data.vrdclen = sizeof(diag_data);
2952         rc = diag210(&diag_data);
2953         if (rc == 0 || rc == 2) {
2954                 return diag_data.vrdcvfla & 0x80;
2955         } else {
2956                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
2957                           dev_id.devno, rc);
2958                 return 0;
2959         }
2960 }
2961 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
2962
2963 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
2964 {
2965         struct ccw_device *cdev = data;
2966         int ret;
2967
2968         ret = ccw_device_set_online(cdev);
2969         if (ret)
2970                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
2971                            dev_name(&cdev->dev), ret);
2972 }
2973
2974 /*
2975  * Initial attempt at a probe function. this can be simplified once
2976  * the other detection code is gone.
2977  */
2978 int dasd_generic_probe(struct ccw_device *cdev,
2979                        struct dasd_discipline *discipline)
2980 {
2981         int ret;
2982
2983         ret = dasd_add_sysfs_files(cdev);
2984         if (ret) {
2985                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
2986                                 "dasd_generic_probe: could not add "
2987                                 "sysfs entries");
2988                 return ret;
2989         }
2990         cdev->handler = &dasd_int_handler;
2991
2992         /*
2993          * Automatically online either all dasd devices (dasd_autodetect)
2994          * or all devices specified with dasd= parameters during
2995          * initial probe.
2996          */
2997         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
2998             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
2999                 async_schedule(dasd_generic_auto_online, cdev);
3000         return 0;
3001 }
3002
3003 /*
3004  * This will one day be called from a global not_oper handler.
3005  * It is also used by driver_unregister during module unload.
3006  */
3007 void dasd_generic_remove(struct ccw_device *cdev)
3008 {
3009         struct dasd_device *device;
3010         struct dasd_block *block;
3011
3012         cdev->handler = NULL;
3013
3014         dasd_remove_sysfs_files(cdev);
3015         device = dasd_device_from_cdev(cdev);
3016         if (IS_ERR(device))
3017                 return;
3018         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3019                 /* Already doing offline processing */
3020                 dasd_put_device(device);
3021                 return;
3022         }
3023         /*
3024          * This device is removed unconditionally. Set offline
3025          * flag to prevent dasd_open from opening it while it is
3026          * no quite down yet.
3027          */
3028         dasd_set_target_state(device, DASD_STATE_NEW);
3029         /* dasd_delete_device destroys the device reference. */
3030         block = device->block;
3031         dasd_delete_device(device);
3032         /*
3033          * life cycle of block is bound to device, so delete it after
3034          * device was safely removed
3035          */
3036         if (block)
3037                 dasd_free_block(block);
3038 }
3039
3040 /*
3041  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3042  * the device is detected for the first time and is supposed to be used
3043  * or the user has started activation through sysfs.
3044  */
3045 int dasd_generic_set_online(struct ccw_device *cdev,
3046                             struct dasd_discipline *base_discipline)
3047 {
3048         struct dasd_discipline *discipline;
3049         struct dasd_device *device;
3050         int rc;
3051
3052         /* first online clears initial online feature flag */
3053         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3054         device = dasd_create_device(cdev);
3055         if (IS_ERR(device))
3056                 return PTR_ERR(device);
3057
3058         discipline = base_discipline;
3059         if (device->features & DASD_FEATURE_USEDIAG) {
3060                 if (!dasd_diag_discipline_pointer) {
3061                         pr_warning("%s Setting the DASD online failed because "
3062                                    "of missing DIAG discipline\n",
3063                                    dev_name(&cdev->dev));
3064                         dasd_delete_device(device);
3065                         return -ENODEV;
3066                 }
3067                 discipline = dasd_diag_discipline_pointer;
3068         }
3069         if (!try_module_get(base_discipline->owner)) {
3070                 dasd_delete_device(device);
3071                 return -EINVAL;
3072         }
3073         if (!try_module_get(discipline->owner)) {
3074                 module_put(base_discipline->owner);
3075                 dasd_delete_device(device);
3076                 return -EINVAL;
3077         }
3078         device->base_discipline = base_discipline;
3079         device->discipline = discipline;
3080
3081         /* check_device will allocate block device if necessary */
3082         rc = discipline->check_device(device);
3083         if (rc) {
3084                 pr_warning("%s Setting the DASD online with discipline %s "
3085                            "failed with rc=%i\n",
3086                            dev_name(&cdev->dev), discipline->name, rc);
3087                 module_put(discipline->owner);
3088                 module_put(base_discipline->owner);
3089                 dasd_delete_device(device);
3090                 return rc;
3091         }
3092
3093         dasd_set_target_state(device, DASD_STATE_ONLINE);
3094         if (device->state <= DASD_STATE_KNOWN) {
3095                 pr_warning("%s Setting the DASD online failed because of a "
3096                            "missing discipline\n", dev_name(&cdev->dev));
3097                 rc = -ENODEV;
3098                 dasd_set_target_state(device, DASD_STATE_NEW);
3099                 if (device->block)
3100                         dasd_free_block(device->block);
3101                 dasd_delete_device(device);
3102         } else
3103                 pr_debug("dasd_generic device %s found\n",
3104                                 dev_name(&cdev->dev));
3105
3106         wait_event(dasd_init_waitq, _wait_for_device(device));
3107
3108         dasd_put_device(device);
3109         return rc;
3110 }
3111
3112 int dasd_generic_set_offline(struct ccw_device *cdev)
3113 {
3114         struct dasd_device *device;
3115         struct dasd_block *block;
3116         int max_count, open_count;
3117
3118         device = dasd_device_from_cdev(cdev);
3119         if (IS_ERR(device))
3120                 return PTR_ERR(device);
3121         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3122                 /* Already doing offline processing */
3123                 dasd_put_device(device);
3124                 return 0;
3125         }
3126         /*
3127          * We must make sure that this device is currently not in use.
3128          * The open_count is increased for every opener, that includes
3129          * the blkdev_get in dasd_scan_partitions. We are only interested
3130          * in the other openers.
3131          */
3132         if (device->block) {
3133                 max_count = device->block->bdev ? 0 : -1;
3134                 open_count = atomic_read(&device->block->open_count);
3135                 if (open_count > max_count) {
3136                         if (open_count > 0)
3137                                 pr_warning("%s: The DASD cannot be set offline "
3138                                            "with open count %i\n",
3139                                            dev_name(&cdev->dev), open_count);
3140                         else
3141                                 pr_warning("%s: The DASD cannot be set offline "
3142                                            "while it is in use\n",
3143                                            dev_name(&cdev->dev));
3144                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3145                         dasd_put_device(device);
3146                         return -EBUSY;
3147                 }
3148         }
3149         dasd_set_target_state(device, DASD_STATE_NEW);
3150         /* dasd_delete_device destroys the device reference. */
3151         block = device->block;
3152         dasd_delete_device(device);
3153         /*
3154          * life cycle of block is bound to device, so delete it after
3155          * device was safely removed
3156          */
3157         if (block)
3158                 dasd_free_block(block);
3159         return 0;
3160 }
3161
3162 int dasd_generic_last_path_gone(struct dasd_device *device)
3163 {
3164         struct dasd_ccw_req *cqr;
3165
3166         dev_warn(&device->cdev->dev, "No operational channel path is left "
3167                  "for the device\n");
3168         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3169         /* First of all call extended error reporting. */
3170         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3171
3172         if (device->state < DASD_STATE_BASIC)
3173                 return 0;
3174         /* Device is active. We want to keep it. */
3175         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3176                 if ((cqr->status == DASD_CQR_IN_IO) ||
3177                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3178                         cqr->status = DASD_CQR_QUEUED;
3179                         cqr->retries++;
3180                 }
3181         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3182         dasd_device_clear_timer(device);
3183         dasd_schedule_device_bh(device);
3184         return 1;
3185 }
3186 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3187
3188 int dasd_generic_path_operational(struct dasd_device *device)
3189 {
3190         dev_info(&device->cdev->dev, "A channel path to the device has become "
3191                  "operational\n");
3192         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3193         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3194         if (device->stopped & DASD_UNRESUMED_PM) {
3195                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3196                 dasd_restore_device(device);
3197                 return 1;
3198         }
3199         dasd_schedule_device_bh(device);
3200         if (device->block)
3201                 dasd_schedule_block_bh(device->block);
3202         return 1;
3203 }
3204 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3205
3206 int dasd_generic_notify(struct ccw_device *cdev, int event)
3207 {
3208         struct dasd_device *device;
3209         int ret;
3210
3211         device = dasd_device_from_cdev_locked(cdev);
3212         if (IS_ERR(device))
3213                 return 0;
3214         ret = 0;
3215         switch (event) {
3216         case CIO_GONE:
3217         case CIO_BOXED:
3218         case CIO_NO_PATH:
3219                 device->path_data.opm = 0;
3220                 device->path_data.ppm = 0;
3221                 device->path_data.npm = 0;
3222                 ret = dasd_generic_last_path_gone(device);
3223                 break;
3224         case CIO_OPER:
3225                 ret = 1;
3226                 if (device->path_data.opm)
3227                         ret = dasd_generic_path_operational(device);
3228                 break;
3229         }
3230         dasd_put_device(device);
3231         return ret;
3232 }
3233
3234 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3235 {
3236         int chp;
3237         __u8 oldopm, eventlpm;
3238         struct dasd_device *device;
3239
3240         device = dasd_device_from_cdev_locked(cdev);
3241         if (IS_ERR(device))
3242                 return;
3243         for (chp = 0; chp < 8; chp++) {
3244                 eventlpm = 0x80 >> chp;
3245                 if (path_event[chp] & PE_PATH_GONE) {
3246                         oldopm = device->path_data.opm;
3247                         device->path_data.opm &= ~eventlpm;
3248                         device->path_data.ppm &= ~eventlpm;
3249                         device->path_data.npm &= ~eventlpm;
3250                         if (oldopm && !device->path_data.opm)
3251                                 dasd_generic_last_path_gone(device);
3252                 }
3253                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3254                         device->path_data.opm &= ~eventlpm;
3255                         device->path_data.ppm &= ~eventlpm;
3256                         device->path_data.npm &= ~eventlpm;
3257                         device->path_data.tbvpm |= eventlpm;
3258                         dasd_schedule_device_bh(device);
3259                 }
3260         }
3261         dasd_put_device(device);
3262 }
3263 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3264
3265 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3266 {
3267         if (!device->path_data.opm && lpm) {
3268                 device->path_data.opm = lpm;
3269                 dasd_generic_path_operational(device);
3270         } else
3271                 device->path_data.opm |= lpm;
3272         return 0;
3273 }
3274 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3275
3276
3277 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3278 {
3279         struct dasd_ccw_req *cqr, *n;
3280         int rc;
3281         struct list_head freeze_queue;
3282         struct dasd_device *device = dasd_device_from_cdev(cdev);
3283
3284         if (IS_ERR(device))
3285                 return PTR_ERR(device);
3286
3287         if (device->discipline->freeze)
3288                 rc = device->discipline->freeze(device);
3289
3290         /* disallow new I/O  */
3291         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3292         /* clear active requests */
3293         INIT_LIST_HEAD(&freeze_queue);
3294         spin_lock_irq(get_ccwdev_lock(cdev));
3295         rc = 0;
3296         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3297                 /* Check status and move request to flush_queue */
3298                 if (cqr->status == DASD_CQR_IN_IO) {
3299                         rc = device->discipline->term_IO(cqr);
3300                         if (rc) {
3301                                 /* unable to terminate requeust */
3302                                 dev_err(&device->cdev->dev,
3303                                         "Unable to terminate request %p "
3304                                         "on suspend\n", cqr);
3305                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3306                                 dasd_put_device(device);
3307                                 return rc;
3308                         }
3309                 }
3310                 list_move_tail(&cqr->devlist, &freeze_queue);
3311         }
3312
3313         spin_unlock_irq(get_ccwdev_lock(cdev));
3314
3315         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3316                 wait_event(dasd_flush_wq,
3317                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3318                 if (cqr->status == DASD_CQR_CLEARED)
3319                         cqr->status = DASD_CQR_QUEUED;
3320         }
3321         /* move freeze_queue to start of the ccw_queue */
3322         spin_lock_irq(get_ccwdev_lock(cdev));
3323         list_splice_tail(&freeze_queue, &device->ccw_queue);
3324         spin_unlock_irq(get_ccwdev_lock(cdev));
3325
3326         dasd_put_device(device);
3327         return rc;
3328 }
3329 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3330
3331 int dasd_generic_restore_device(struct ccw_device *cdev)
3332 {
3333         struct dasd_device *device = dasd_device_from_cdev(cdev);
3334         int rc = 0;
3335
3336         if (IS_ERR(device))
3337                 return PTR_ERR(device);
3338
3339         /* allow new IO again */
3340         dasd_device_remove_stop_bits(device,
3341                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3342
3343         dasd_schedule_device_bh(device);
3344
3345         /*
3346          * call discipline restore function
3347          * if device is stopped do nothing e.g. for disconnected devices
3348          */
3349         if (device->discipline->restore && !(device->stopped))
3350                 rc = device->discipline->restore(device);
3351         if (rc || device->stopped)
3352                 /*
3353                  * if the resume failed for the DASD we put it in
3354                  * an UNRESUMED stop state
3355                  */
3356                 device->stopped |= DASD_UNRESUMED_PM;
3357
3358         if (device->block)
3359                 dasd_schedule_block_bh(device->block);
3360
3361         dasd_put_device(device);
3362         return 0;
3363 }
3364 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3365
3366 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3367                                                    void *rdc_buffer,
3368                                                    int rdc_buffer_size,
3369                                                    int magic)
3370 {
3371         struct dasd_ccw_req *cqr;
3372         struct ccw1 *ccw;
3373         unsigned long *idaw;
3374
3375         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3376
3377         if (IS_ERR(cqr)) {
3378                 /* internal error 13 - Allocating the RDC request failed*/
3379                 dev_err(&device->cdev->dev,
3380                          "An error occurred in the DASD device driver, "
3381                          "reason=%s\n", "13");
3382                 return cqr;
3383         }
3384
3385         ccw = cqr->cpaddr;
3386         ccw->cmd_code = CCW_CMD_RDC;
3387         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3388                 idaw = (unsigned long *) (cqr->data);
3389                 ccw->cda = (__u32)(addr_t) idaw;
3390                 ccw->flags = CCW_FLAG_IDA;
3391                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3392         } else {
3393                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3394                 ccw->flags = 0;
3395         }
3396
3397         ccw->count = rdc_buffer_size;
3398         cqr->startdev = device;
3399         cqr->memdev = device;
3400         cqr->expires = 10*HZ;
3401         cqr->retries = 256;
3402         cqr->buildclk = get_clock();
3403         cqr->status = DASD_CQR_FILLED;
3404         return cqr;
3405 }
3406
3407
3408 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3409                                 void *rdc_buffer, int rdc_buffer_size)
3410 {
3411         int ret;
3412         struct dasd_ccw_req *cqr;
3413
3414         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3415                                      magic);
3416         if (IS_ERR(cqr))
3417                 return PTR_ERR(cqr);
3418
3419         ret = dasd_sleep_on(cqr);
3420         dasd_sfree_request(cqr, cqr->memdev);
3421         return ret;
3422 }
3423 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3424
3425 /*
3426  *   In command mode and transport mode we need to look for sense
3427  *   data in different places. The sense data itself is allways
3428  *   an array of 32 bytes, so we can unify the sense data access
3429  *   for both modes.
3430  */
3431 char *dasd_get_sense(struct irb *irb)
3432 {
3433         struct tsb *tsb = NULL;
3434         char *sense = NULL;
3435
3436         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3437                 if (irb->scsw.tm.tcw)
3438                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3439                                           irb->scsw.tm.tcw);
3440                 if (tsb && tsb->length == 64 && tsb->flags)
3441                         switch (tsb->flags & 0x07) {
3442                         case 1: /* tsa_iostat */
3443                                 sense = tsb->tsa.iostat.sense;
3444                                 break;
3445                         case 2: /* tsa_ddpc */
3446                                 sense = tsb->tsa.ddpc.sense;
3447                                 break;
3448                         default:
3449                                 /* currently we don't use interrogate data */
3450                                 break;
3451                         }
3452         } else if (irb->esw.esw0.erw.cons) {
3453                 sense = irb->ecw;
3454         }
3455         return sense;
3456 }
3457 EXPORT_SYMBOL_GPL(dasd_get_sense);
3458
3459 static int __init dasd_init(void)
3460 {
3461         int rc;
3462
3463         init_waitqueue_head(&dasd_init_waitq);
3464         init_waitqueue_head(&dasd_flush_wq);
3465         init_waitqueue_head(&generic_waitq);
3466
3467         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3468         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3469         if (dasd_debug_area == NULL) {
3470                 rc = -ENOMEM;
3471                 goto failed;
3472         }
3473         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3474         debug_set_level(dasd_debug_area, DBF_WARNING);
3475
3476         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3477
3478         dasd_diag_discipline_pointer = NULL;
3479
3480         dasd_statistics_createroot();
3481
3482         rc = dasd_devmap_init();
3483         if (rc)
3484                 goto failed;
3485         rc = dasd_gendisk_init();
3486         if (rc)
3487                 goto failed;
3488         rc = dasd_parse();
3489         if (rc)
3490                 goto failed;
3491         rc = dasd_eer_init();
3492         if (rc)
3493                 goto failed;
3494 #ifdef CONFIG_PROC_FS
3495         rc = dasd_proc_init();
3496         if (rc)
3497                 goto failed;
3498 #endif
3499
3500         return 0;
3501 failed:
3502         pr_info("The DASD device driver could not be initialized\n");
3503         dasd_exit();
3504         return rc;
3505 }
3506
3507 module_init(dasd_init);
3508 module_exit(dasd_exit);
3509
3510 EXPORT_SYMBOL(dasd_debug_area);
3511 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
3512
3513 EXPORT_SYMBOL(dasd_add_request_head);
3514 EXPORT_SYMBOL(dasd_add_request_tail);
3515 EXPORT_SYMBOL(dasd_cancel_req);
3516 EXPORT_SYMBOL(dasd_device_clear_timer);
3517 EXPORT_SYMBOL(dasd_block_clear_timer);
3518 EXPORT_SYMBOL(dasd_enable_device);
3519 EXPORT_SYMBOL(dasd_int_handler);
3520 EXPORT_SYMBOL(dasd_kfree_request);
3521 EXPORT_SYMBOL(dasd_kick_device);
3522 EXPORT_SYMBOL(dasd_kmalloc_request);
3523 EXPORT_SYMBOL(dasd_schedule_device_bh);
3524 EXPORT_SYMBOL(dasd_schedule_block_bh);
3525 EXPORT_SYMBOL(dasd_set_target_state);
3526 EXPORT_SYMBOL(dasd_device_set_timer);
3527 EXPORT_SYMBOL(dasd_block_set_timer);
3528 EXPORT_SYMBOL(dasd_sfree_request);
3529 EXPORT_SYMBOL(dasd_sleep_on);
3530 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
3531 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
3532 EXPORT_SYMBOL(dasd_smalloc_request);
3533 EXPORT_SYMBOL(dasd_start_IO);
3534 EXPORT_SYMBOL(dasd_term_IO);
3535
3536 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3537 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3538 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3539 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3540 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3541 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
3542 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
3543 EXPORT_SYMBOL_GPL(dasd_alloc_block);
3544 EXPORT_SYMBOL_GPL(dasd_free_block);