drivers/s390/block/dasd.c

   1 /*
   2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   3  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   4  *                  Carsten Otte <Cotte@de.ibm.com>
   5  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  * Bugreports.to..: <Linux390@de.ibm.com>
   7  * Copyright IBM Corp. 1999, 2009
   8  */
   9
  10 #define KMSG_COMPONENT "dasd"
  11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13 #include <linux/kmod.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ctype.h>
  17 #include <linux/major.h>
  18 #include <linux/slab.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/async.h>
  21 #include <linux/mutex.h>
  22 #include <linux/debugfs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/vmalloc.h>
  25
  26 #include <asm/ccwdev.h>
  27 #include <asm/ebcdic.h>
  28 #include <asm/idals.h>
  29 #include <asm/itcw.h>
  30 #include <asm/diag.h>
  31
  32 /* This is ugly... */
  33 #define PRINTK_HEADER "dasd:"
  34
  35 #include "dasd_int.h"
  36 /*
  37  * SECTION: Constant definitions to be used within this file
  38  */
  39 #define DASD_CHANQ_MAX_SIZE 4
  40
  41 #define DASD_DIAG_MOD           "dasd_diag_mod"
  42
  43 /*
  44  * SECTION: exported variables of dasd.c
  45  */
  46 debug_info_t *dasd_debug_area;
  47 EXPORT_SYMBOL(dasd_debug_area);
  48 static struct dentry *dasd_debugfs_root_entry;
  49 struct dasd_discipline *dasd_diag_discipline_pointer;
  50 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  52
  53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  55                    " Copyright IBM Corp. 2000");
  56 MODULE_SUPPORTED_DEVICE("dasd");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int  dasd_alloc_queue(struct dasd_block *);
  63 static void dasd_setup_queue(struct dasd_block *);
  64 static void dasd_free_queue(struct dasd_block *);
  65 static int dasd_flush_block_queue(struct dasd_block *);
  66 static void dasd_device_tasklet(struct dasd_device *);
  67 static void dasd_block_tasklet(struct dasd_block *);
  68 static void do_kick_device(struct work_struct *);
  69 static void do_restore_device(struct work_struct *);
  70 static void do_reload_device(struct work_struct *);
  71 static void do_requeue_requests(struct work_struct *);
  72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  73 static void dasd_device_timeout(unsigned long);
  74 static void dasd_block_timeout(unsigned long);
  75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  77 static void dasd_profile_exit(struct dasd_profile *);
  78 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  79 static void dasd_hosts_exit(struct dasd_device *);
  80
  81 /*
  82  * SECTION: Operations on the device structure.
  83  */
  84 static wait_queue_head_t dasd_init_waitq;
  85 static wait_queue_head_t dasd_flush_wq;
  86 static wait_queue_head_t generic_waitq;
  87 static wait_queue_head_t shutdown_waitq;
  88
  89 /*
  90  * Allocate memory for a new device structure.
  91  */
  92 struct dasd_device *dasd_alloc_device(void)
  93 {
  94         struct dasd_device *device;
  95
  96         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  97         if (!device)
  98                 return ERR_PTR(-ENOMEM);
  99
 100         /* Get two pages for normal block device operations. */
 101         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 102         if (!device->ccw_mem) {
 103                 kfree(device);
 104                 return ERR_PTR(-ENOMEM);
 105         }
 106         /* Get one page for error recovery. */
 107         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 108         if (!device->erp_mem) {
 109                 free_pages((unsigned long) device->ccw_mem, 1);
 110                 kfree(device);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 115         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 116         spin_lock_init(&device->mem_lock);
 117         atomic_set(&device->tasklet_scheduled, 0);
 118         tasklet_init(&device->tasklet,
 119                      (void (*)(unsigned long)) dasd_device_tasklet,
 120                      (unsigned long) device);
 121         INIT_LIST_HEAD(&device->ccw_queue);
 122         init_timer(&device->timer);
 123         device->timer.function = dasd_device_timeout;
 124         device->timer.data = (unsigned long) device;
 125         INIT_WORK(&device->kick_work, do_kick_device);
 126         INIT_WORK(&device->restore_device, do_restore_device);
 127         INIT_WORK(&device->reload_device, do_reload_device);
 128         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 129         device->state = DASD_STATE_NEW;
 130         device->target = DASD_STATE_NEW;
 131         mutex_init(&device->state_mutex);
 132         spin_lock_init(&device->profile.lock);
 133         return device;
 134 }
 135
 136 /*
 137  * Free memory of a device structure.
 138  */
 139 void dasd_free_device(struct dasd_device *device)
 140 {
 141         kfree(device->private);
 142         free_page((unsigned long) device->erp_mem);
 143         free_pages((unsigned long) device->ccw_mem, 1);
 144         kfree(device);
 145 }
 146
 147 /*
 148  * Allocate memory for a new device structure.
 149  */
 150 struct dasd_block *dasd_alloc_block(void)
 151 {
 152         struct dasd_block *block;
 153
 154         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 155         if (!block)
 156                 return ERR_PTR(-ENOMEM);
 157         /* open_count = 0 means device online but not in use */
 158         atomic_set(&block->open_count, -1);
 159
 160         atomic_set(&block->tasklet_scheduled, 0);
 161         tasklet_init(&block->tasklet,
 162                      (void (*)(unsigned long)) dasd_block_tasklet,
 163                      (unsigned long) block);
 164         INIT_LIST_HEAD(&block->ccw_queue);
 165         spin_lock_init(&block->queue_lock);
 166         init_timer(&block->timer);
 167         block->timer.function = dasd_block_timeout;
 168         block->timer.data = (unsigned long) block;
 169         spin_lock_init(&block->profile.lock);
 170
 171         return block;
 172 }
 173 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 174
 175 /*
 176  * Free memory of a device structure.
 177  */
 178 void dasd_free_block(struct dasd_block *block)
 179 {
 180         kfree(block);
 181 }
 182 EXPORT_SYMBOL_GPL(dasd_free_block);
 183
 184 /*
 185  * Make a new device known to the system.
 186  */
 187 static int dasd_state_new_to_known(struct dasd_device *device)
 188 {
 189         int rc;
 190
 191         /*
 192          * As long as the device is not in state DASD_STATE_NEW we want to
 193          * keep the reference count > 0.
 194          */
 195         dasd_get_device(device);
 196
 197         if (device->block) {
 198                 rc = dasd_alloc_queue(device->block);
 199                 if (rc) {
 200                         dasd_put_device(device);
 201                         return rc;
 202                 }
 203         }
 204         device->state = DASD_STATE_KNOWN;
 205         return 0;
 206 }
 207
 208 /*
 209  * Let the system forget about a device.
 210  */
 211 static int dasd_state_known_to_new(struct dasd_device *device)
 212 {
 213         /* Disable extended error reporting for this device. */
 214         dasd_eer_disable(device);
 215         device->state = DASD_STATE_NEW;
 216
 217         if (device->block)
 218                 dasd_free_queue(device->block);
 219
 220         /* Give up reference we took in dasd_state_new_to_known. */
 221         dasd_put_device(device);
 222         return 0;
 223 }
 224
 225 static struct dentry *dasd_debugfs_setup(const char *name,
 226                                          struct dentry *base_dentry)
 227 {
 228         struct dentry *pde;
 229
 230         if (!base_dentry)
 231                 return NULL;
 232         pde = debugfs_create_dir(name, base_dentry);
 233         if (!pde || IS_ERR(pde))
 234                 return NULL;
 235         return pde;
 236 }
 237
 238 /*
 239  * Request the irq line for the device.
 240  */
 241 static int dasd_state_known_to_basic(struct dasd_device *device)
 242 {
 243         struct dasd_block *block = device->block;
 244         int rc = 0;
 245
 246         /* Allocate and register gendisk structure. */
 247         if (block) {
 248                 rc = dasd_gendisk_alloc(block);
 249                 if (rc)
 250                         return rc;
 251                 block->debugfs_dentry =
 252                         dasd_debugfs_setup(block->gdp->disk_name,
 253                                            dasd_debugfs_root_entry);
 254                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 255                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 256                         dasd_profile_on(&device->block->profile);
 257         }
 258         device->debugfs_dentry =
 259                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 260                                    dasd_debugfs_root_entry);
 261         dasd_profile_init(&device->profile, device->debugfs_dentry);
 262         dasd_hosts_init(device->debugfs_dentry, device);
 263
 264         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 265         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 266                                             8 * sizeof(long));
 267         debug_register_view(device->debug_area, &debug_sprintf_view);
 268         debug_set_level(device->debug_area, DBF_WARNING);
 269         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 270
 271         device->state = DASD_STATE_BASIC;
 272
 273         return rc;
 274 }
 275
 276 /*
 277  * Release the irq line for the device. Terminate any running i/o.
 278  */
 279 static int dasd_state_basic_to_known(struct dasd_device *device)
 280 {
 281         int rc;
 282
 283         if (device->discipline->basic_to_known) {
 284                 rc = device->discipline->basic_to_known(device);
 285                 if (rc)
 286                         return rc;
 287         }
 288
 289         if (device->block) {
 290                 dasd_profile_exit(&device->block->profile);
 291                 debugfs_remove(device->block->debugfs_dentry);
 292                 dasd_gendisk_free(device->block);
 293                 dasd_block_clear_timer(device->block);
 294         }
 295         rc = dasd_flush_device_queue(device);
 296         if (rc)
 297                 return rc;
 298         dasd_device_clear_timer(device);
 299         dasd_profile_exit(&device->profile);
 300         dasd_hosts_exit(device);
 301         debugfs_remove(device->debugfs_dentry);
 302         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 303         if (device->debug_area != NULL) {
 304                 debug_unregister(device->debug_area);
 305                 device->debug_area = NULL;
 306         }
 307         device->state = DASD_STATE_KNOWN;
 308         return 0;
 309 }
 310
 311 /*
 312  * Do the initial analysis. The do_analysis function may return
 313  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 314  * until the discipline decides to continue the startup sequence
 315  * by calling the function dasd_change_state. The eckd disciplines
 316  * uses this to start a ccw that detects the format. The completion
 317  * interrupt for this detection ccw uses the kernel event daemon to
 318  * trigger the call to dasd_change_state. All this is done in the
 319  * discipline code, see dasd_eckd.c.
 320  * After the analysis ccw is done (do_analysis returned 0) the block
 321  * device is setup.
 322  * In case the analysis returns an error, the device setup is stopped
 323  * (a fake disk was already added to allow formatting).
 324  */
 325 static int dasd_state_basic_to_ready(struct dasd_device *device)
 326 {
 327         int rc;
 328         struct dasd_block *block;
 329         struct gendisk *disk;
 330
 331         rc = 0;
 332         block = device->block;
 333         /* make disk known with correct capacity */
 334         if (block) {
 335                 if (block->base->discipline->do_analysis != NULL)
 336                         rc = block->base->discipline->do_analysis(block);
 337                 if (rc) {
 338                         if (rc != -EAGAIN) {
 339                                 device->state = DASD_STATE_UNFMT;
 340                                 disk = device->block->gdp;
 341                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 342                                                KOBJ_CHANGE);
 343                                 goto out;
 344                         }
 345                         return rc;
 346                 }
 347                 dasd_setup_queue(block);
 348                 set_capacity(block->gdp,
 349                              block->blocks << block->s2b_shift);
 350                 device->state = DASD_STATE_READY;
 351                 rc = dasd_scan_partitions(block);
 352                 if (rc) {
 353                         device->state = DASD_STATE_BASIC;
 354                         return rc;
 355                 }
 356         } else {
 357                 device->state = DASD_STATE_READY;
 358         }
 359 out:
 360         if (device->discipline->basic_to_ready)
 361                 rc = device->discipline->basic_to_ready(device);
 362         return rc;
 363 }
 364
 365 static inline
 366 int _wait_for_empty_queues(struct dasd_device *device)
 367 {
 368         if (device->block)
 369                 return list_empty(&device->ccw_queue) &&
 370                         list_empty(&device->block->ccw_queue);
 371         else
 372                 return list_empty(&device->ccw_queue);
 373 }
 374
 375 /*
 376  * Remove device from block device layer. Destroy dirty buffers.
 377  * Forget format information. Check if the target level is basic
 378  * and if it is create fake disk for formatting.
 379  */
 380 static int dasd_state_ready_to_basic(struct dasd_device *device)
 381 {
 382         int rc;
 383
 384         device->state = DASD_STATE_BASIC;
 385         if (device->block) {
 386                 struct dasd_block *block = device->block;
 387                 rc = dasd_flush_block_queue(block);
 388                 if (rc) {
 389                         device->state = DASD_STATE_READY;
 390                         return rc;
 391                 }
 392                 dasd_destroy_partitions(block);
 393                 block->blocks = 0;
 394                 block->bp_block = 0;
 395                 block->s2b_shift = 0;
 396         }
 397         return 0;
 398 }
 399
 400 /*
 401  * Back to basic.
 402  */
 403 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 404 {
 405         device->state = DASD_STATE_BASIC;
 406         return 0;
 407 }
 408
 409 /*
 410  * Make the device online and schedule the bottom half to start
 411  * the requeueing of requests from the linux request queue to the
 412  * ccw queue.
 413  */
 414 static int
 415 dasd_state_ready_to_online(struct dasd_device * device)
 416 {
 417         struct gendisk *disk;
 418         struct disk_part_iter piter;
 419         struct hd_struct *part;
 420
 421         device->state = DASD_STATE_ONLINE;
 422         if (device->block) {
 423                 dasd_schedule_block_bh(device->block);
 424                 if ((device->features & DASD_FEATURE_USERAW)) {
 425                         disk = device->block->gdp;
 426                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 427                         return 0;
 428                 }
 429                 disk = device->block->bdev->bd_disk;
 430                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 431                 while ((part = disk_part_iter_next(&piter)))
 432                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 433                 disk_part_iter_exit(&piter);
 434         }
 435         return 0;
 436 }
 437
 438 /*
 439  * Stop the requeueing of requests again.
 440  */
 441 static int dasd_state_online_to_ready(struct dasd_device *device)
 442 {
 443         int rc;
 444         struct gendisk *disk;
 445         struct disk_part_iter piter;
 446         struct hd_struct *part;
 447
 448         if (device->discipline->online_to_ready) {
 449                 rc = device->discipline->online_to_ready(device);
 450                 if (rc)
 451                         return rc;
 452         }
 453
 454         device->state = DASD_STATE_READY;
 455         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 456                 disk = device->block->bdev->bd_disk;
 457                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 458                 while ((part = disk_part_iter_next(&piter)))
 459                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 460                 disk_part_iter_exit(&piter);
 461         }
 462         return 0;
 463 }
 464
 465 /*
 466  * Device startup state changes.
 467  */
 468 static int dasd_increase_state(struct dasd_device *device)
 469 {
 470         int rc;
 471
 472         rc = 0;
 473         if (device->state == DASD_STATE_NEW &&
 474             device->target >= DASD_STATE_KNOWN)
 475                 rc = dasd_state_new_to_known(device);
 476
 477         if (!rc &&
 478             device->state == DASD_STATE_KNOWN &&
 479             device->target >= DASD_STATE_BASIC)
 480                 rc = dasd_state_known_to_basic(device);
 481
 482         if (!rc &&
 483             device->state == DASD_STATE_BASIC &&
 484             device->target >= DASD_STATE_READY)
 485                 rc = dasd_state_basic_to_ready(device);
 486
 487         if (!rc &&
 488             device->state == DASD_STATE_UNFMT &&
 489             device->target > DASD_STATE_UNFMT)
 490                 rc = -EPERM;
 491
 492         if (!rc &&
 493             device->state == DASD_STATE_READY &&
 494             device->target >= DASD_STATE_ONLINE)
 495                 rc = dasd_state_ready_to_online(device);
 496
 497         return rc;
 498 }
 499
 500 /*
 501  * Device shutdown state changes.
 502  */
 503 static int dasd_decrease_state(struct dasd_device *device)
 504 {
 505         int rc;
 506
 507         rc = 0;
 508         if (device->state == DASD_STATE_ONLINE &&
 509             device->target <= DASD_STATE_READY)
 510                 rc = dasd_state_online_to_ready(device);
 511
 512         if (!rc &&
 513             device->state == DASD_STATE_READY &&
 514             device->target <= DASD_STATE_BASIC)
 515                 rc = dasd_state_ready_to_basic(device);
 516
 517         if (!rc &&
 518             device->state == DASD_STATE_UNFMT &&
 519             device->target <= DASD_STATE_BASIC)
 520                 rc = dasd_state_unfmt_to_basic(device);
 521
 522         if (!rc &&
 523             device->state == DASD_STATE_BASIC &&
 524             device->target <= DASD_STATE_KNOWN)
 525                 rc = dasd_state_basic_to_known(device);
 526
 527         if (!rc &&
 528             device->state == DASD_STATE_KNOWN &&
 529             device->target <= DASD_STATE_NEW)
 530                 rc = dasd_state_known_to_new(device);
 531
 532         return rc;
 533 }
 534
 535 /*
 536  * This is the main startup/shutdown routine.
 537  */
 538 static void dasd_change_state(struct dasd_device *device)
 539 {
 540         int rc;
 541
 542         if (device->state == device->target)
 543                 /* Already where we want to go today... */
 544                 return;
 545         if (device->state < device->target)
 546                 rc = dasd_increase_state(device);
 547         else
 548                 rc = dasd_decrease_state(device);
 549         if (rc == -EAGAIN)
 550                 return;
 551         if (rc)
 552                 device->target = device->state;
 553
 554         /* let user-space know that the device status changed */
 555         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 556
 557         if (device->state == device->target)
 558                 wake_up(&dasd_init_waitq);
 559 }
 560
 561 /*
 562  * Kick starter for devices that did not complete the startup/shutdown
 563  * procedure or were sleeping because of a pending state.
 564  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 565  * event daemon.
 566  */
 567 static void do_kick_device(struct work_struct *work)
 568 {
 569         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 570         mutex_lock(&device->state_mutex);
 571         dasd_change_state(device);
 572         mutex_unlock(&device->state_mutex);
 573         dasd_schedule_device_bh(device);
 574         dasd_put_device(device);
 575 }
 576
 577 void dasd_kick_device(struct dasd_device *device)
 578 {
 579         dasd_get_device(device);
 580         /* queue call to dasd_kick_device to the kernel event daemon. */
 581         if (!schedule_work(&device->kick_work))
 582                 dasd_put_device(device);
 583 }
 584 EXPORT_SYMBOL(dasd_kick_device);
 585
 586 /*
 587  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 588  * event daemon.
 589  */
 590 static void do_reload_device(struct work_struct *work)
 591 {
 592         struct dasd_device *device = container_of(work, struct dasd_device,
 593                                                   reload_device);
 594         device->discipline->reload(device);
 595         dasd_put_device(device);
 596 }
 597
 598 void dasd_reload_device(struct dasd_device *device)
 599 {
 600         dasd_get_device(device);
 601         /* queue call to dasd_reload_device to the kernel event daemon. */
 602         if (!schedule_work(&device->reload_device))
 603                 dasd_put_device(device);
 604 }
 605 EXPORT_SYMBOL(dasd_reload_device);
 606
 607 /*
 608  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 609  * event daemon.
 610  */
 611 static void do_restore_device(struct work_struct *work)
 612 {
 613         struct dasd_device *device = container_of(work, struct dasd_device,
 614                                                   restore_device);
 615         device->cdev->drv->restore(device->cdev);
 616         dasd_put_device(device);
 617 }
 618
 619 void dasd_restore_device(struct dasd_device *device)
 620 {
 621         dasd_get_device(device);
 622         /* queue call to dasd_restore_device to the kernel event daemon. */
 623         if (!schedule_work(&device->restore_device))
 624                 dasd_put_device(device);
 625 }
 626
 627 /*
 628  * Set the target state for a device and starts the state change.
 629  */
 630 void dasd_set_target_state(struct dasd_device *device, int target)
 631 {
 632         dasd_get_device(device);
 633         mutex_lock(&device->state_mutex);
 634         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 635         if (dasd_probeonly && target > DASD_STATE_READY)
 636                 target = DASD_STATE_READY;
 637         if (device->target != target) {
 638                 if (device->state == target)
 639                         wake_up(&dasd_init_waitq);
 640                 device->target = target;
 641         }
 642         if (device->state != device->target)
 643                 dasd_change_state(device);
 644         mutex_unlock(&device->state_mutex);
 645         dasd_put_device(device);
 646 }
 647 EXPORT_SYMBOL(dasd_set_target_state);
 648
 649 /*
 650  * Enable devices with device numbers in [from..to].
 651  */
 652 static inline int _wait_for_device(struct dasd_device *device)
 653 {
 654         return (device->state == device->target);
 655 }
 656
 657 void dasd_enable_device(struct dasd_device *device)
 658 {
 659         dasd_set_target_state(device, DASD_STATE_ONLINE);
 660         if (device->state <= DASD_STATE_KNOWN)
 661                 /* No discipline for device found. */
 662                 dasd_set_target_state(device, DASD_STATE_NEW);
 663         /* Now wait for the devices to come up. */
 664         wait_event(dasd_init_waitq, _wait_for_device(device));
 665
 666         dasd_reload_device(device);
 667         if (device->discipline->kick_validate)
 668                 device->discipline->kick_validate(device);
 669 }
 670 EXPORT_SYMBOL(dasd_enable_device);
 671
 672 /*
 673  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 674  */
 675
 676 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 677
 678 #ifdef CONFIG_DASD_PROFILE
 679 struct dasd_profile dasd_global_profile = {
 680         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 681 };
 682 static struct dentry *dasd_debugfs_global_entry;
 683
 684 /*
 685  * Add profiling information for cqr before execution.
 686  */
 687 static void dasd_profile_start(struct dasd_block *block,
 688                                struct dasd_ccw_req *cqr,
 689                                struct request *req)
 690 {
 691         struct list_head *l;
 692         unsigned int counter;
 693         struct dasd_device *device;
 694
 695         /* count the length of the chanq for statistics */
 696         counter = 0;
 697         if (dasd_global_profile_level || block->profile.data)
 698                 list_for_each(l, &block->ccw_queue)
 699                         if (++counter >= 31)
 700                                 break;
 701
 702         spin_lock(&dasd_global_profile.lock);
 703         if (dasd_global_profile.data) {
 704                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 705                 if (rq_data_dir(req) == READ)
 706                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 707         }
 708         spin_unlock(&dasd_global_profile.lock);
 709
 710         spin_lock(&block->profile.lock);
 711         if (block->profile.data) {
 712                 block->profile.data->dasd_io_nr_req[counter]++;
 713                 if (rq_data_dir(req) == READ)
 714                         block->profile.data->dasd_read_nr_req[counter]++;
 715         }
 716         spin_unlock(&block->profile.lock);
 717
 718         /*
 719          * We count the request for the start device, even though it may run on
 720          * some other device due to error recovery. This way we make sure that
 721          * we count each request only once.
 722          */
 723         device = cqr->startdev;
 724         if (device->profile.data) {
 725                 counter = 1; /* request is not yet queued on the start device */
 726                 list_for_each(l, &device->ccw_queue)
 727                         if (++counter >= 31)
 728                                 break;
 729         }
 730         spin_lock(&device->profile.lock);
 731         if (device->profile.data) {
 732                 device->profile.data->dasd_io_nr_req[counter]++;
 733                 if (rq_data_dir(req) == READ)
 734                         device->profile.data->dasd_read_nr_req[counter]++;
 735         }
 736         spin_unlock(&device->profile.lock);
 737 }
 738
 739 /*
 740  * Add profiling information for cqr after execution.
 741  */
 742
 743 #define dasd_profile_counter(value, index)                         \
 744 {                                                                  \
 745         for (index = 0; index < 31 && value >> (2+index); index++) \
 746                 ;                                                  \
 747 }
 748
 749 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 750                                       int is_alias,
 751                                       int is_tpm,
 752                                       int is_read,
 753                                       long sectors,
 754                                       int sectors_ind,
 755                                       int tottime_ind,
 756                                       int tottimeps_ind,
 757                                       int strtime_ind,
 758                                       int irqtime_ind,
 759                                       int irqtimeps_ind,
 760                                       int endtime_ind)
 761 {
 762         /* in case of an overflow, reset the whole profile */
 763         if (data->dasd_io_reqs == UINT_MAX) {
 764                         memset(data, 0, sizeof(*data));
 765                         getnstimeofday(&data->starttod);
 766         }
 767         data->dasd_io_reqs++;
 768         data->dasd_io_sects += sectors;
 769         if (is_alias)
 770                 data->dasd_io_alias++;
 771         if (is_tpm)
 772                 data->dasd_io_tpm++;
 773
 774         data->dasd_io_secs[sectors_ind]++;
 775         data->dasd_io_times[tottime_ind]++;
 776         data->dasd_io_timps[tottimeps_ind]++;
 777         data->dasd_io_time1[strtime_ind]++;
 778         data->dasd_io_time2[irqtime_ind]++;
 779         data->dasd_io_time2ps[irqtimeps_ind]++;
 780         data->dasd_io_time3[endtime_ind]++;
 781
 782         if (is_read) {
 783                 data->dasd_read_reqs++;
 784                 data->dasd_read_sects += sectors;
 785                 if (is_alias)
 786                         data->dasd_read_alias++;
 787                 if (is_tpm)
 788                         data->dasd_read_tpm++;
 789                 data->dasd_read_secs[sectors_ind]++;
 790                 data->dasd_read_times[tottime_ind]++;
 791                 data->dasd_read_time1[strtime_ind]++;
 792                 data->dasd_read_time2[irqtime_ind]++;
 793                 data->dasd_read_time3[endtime_ind]++;
 794         }
 795 }
 796
 797 static void dasd_profile_end(struct dasd_block *block,
 798                              struct dasd_ccw_req *cqr,
 799                              struct request *req)
 800 {
 801         unsigned long strtime, irqtime, endtime, tottime;
 802         unsigned long tottimeps, sectors;
 803         struct dasd_device *device;
 804         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 805         int irqtime_ind, irqtimeps_ind, endtime_ind;
 806         struct dasd_profile_info *data;
 807
 808         device = cqr->startdev;
 809         if (!(dasd_global_profile_level ||
 810               block->profile.data ||
 811               device->profile.data))
 812                 return;
 813
 814         sectors = blk_rq_sectors(req);
 815         if (!cqr->buildclk || !cqr->startclk ||
 816             !cqr->stopclk || !cqr->endclk ||
 817             !sectors)
 818                 return;
 819
 820         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 821         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 822         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 823         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 824         tottimeps = tottime / sectors;
 825
 826         dasd_profile_counter(sectors, sectors_ind);
 827         dasd_profile_counter(tottime, tottime_ind);
 828         dasd_profile_counter(tottimeps, tottimeps_ind);
 829         dasd_profile_counter(strtime, strtime_ind);
 830         dasd_profile_counter(irqtime, irqtime_ind);
 831         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 832         dasd_profile_counter(endtime, endtime_ind);
 833
 834         spin_lock(&dasd_global_profile.lock);
 835         if (dasd_global_profile.data) {
 836                 data = dasd_global_profile.data;
 837                 data->dasd_sum_times += tottime;
 838                 data->dasd_sum_time_str += strtime;
 839                 data->dasd_sum_time_irq += irqtime;
 840                 data->dasd_sum_time_end += endtime;
 841                 dasd_profile_end_add_data(dasd_global_profile.data,
 842                                           cqr->startdev != block->base,
 843                                           cqr->cpmode == 1,
 844                                           rq_data_dir(req) == READ,
 845                                           sectors, sectors_ind, tottime_ind,
 846                                           tottimeps_ind, strtime_ind,
 847                                           irqtime_ind, irqtimeps_ind,
 848                                           endtime_ind);
 849         }
 850         spin_unlock(&dasd_global_profile.lock);
 851
 852         spin_lock(&block->profile.lock);
 853         if (block->profile.data) {
 854                 data = block->profile.data;
 855                 data->dasd_sum_times += tottime;
 856                 data->dasd_sum_time_str += strtime;
 857                 data->dasd_sum_time_irq += irqtime;
 858                 data->dasd_sum_time_end += endtime;
 859                 dasd_profile_end_add_data(block->profile.data,
 860                                           cqr->startdev != block->base,
 861                                           cqr->cpmode == 1,
 862                                           rq_data_dir(req) == READ,
 863                                           sectors, sectors_ind, tottime_ind,
 864                                           tottimeps_ind, strtime_ind,
 865                                           irqtime_ind, irqtimeps_ind,
 866                                           endtime_ind);
 867         }
 868         spin_unlock(&block->profile.lock);
 869
 870         spin_lock(&device->profile.lock);
 871         if (device->profile.data) {
 872                 data = device->profile.data;
 873                 data->dasd_sum_times += tottime;
 874                 data->dasd_sum_time_str += strtime;
 875                 data->dasd_sum_time_irq += irqtime;
 876                 data->dasd_sum_time_end += endtime;
 877                 dasd_profile_end_add_data(device->profile.data,
 878                                           cqr->startdev != block->base,
 879                                           cqr->cpmode == 1,
 880                                           rq_data_dir(req) == READ,
 881                                           sectors, sectors_ind, tottime_ind,
 882                                           tottimeps_ind, strtime_ind,
 883                                           irqtime_ind, irqtimeps_ind,
 884                                           endtime_ind);
 885         }
 886         spin_unlock(&device->profile.lock);
 887 }
 888
 889 void dasd_profile_reset(struct dasd_profile *profile)
 890 {
 891         struct dasd_profile_info *data;
 892
 893         spin_lock_bh(&profile->lock);
 894         data = profile->data;
 895         if (!data) {
 896                 spin_unlock_bh(&profile->lock);
 897                 return;
 898         }
 899         memset(data, 0, sizeof(*data));
 900         getnstimeofday(&data->starttod);
 901         spin_unlock_bh(&profile->lock);
 902 }
 903
 904 int dasd_profile_on(struct dasd_profile *profile)
 905 {
 906         struct dasd_profile_info *data;
 907
 908         data = kzalloc(sizeof(*data), GFP_KERNEL);
 909         if (!data)
 910                 return -ENOMEM;
 911         spin_lock_bh(&profile->lock);
 912         if (profile->data) {
 913                 spin_unlock_bh(&profile->lock);
 914                 kfree(data);
 915                 return 0;
 916         }
 917         getnstimeofday(&data->starttod);
 918         profile->data = data;
 919         spin_unlock_bh(&profile->lock);
 920         return 0;
 921 }
 922
 923 void dasd_profile_off(struct dasd_profile *profile)
 924 {
 925         spin_lock_bh(&profile->lock);
 926         kfree(profile->data);
 927         profile->data = NULL;
 928         spin_unlock_bh(&profile->lock);
 929 }
 930
 931 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 932 {
 933         char *buffer;
 934
 935         buffer = vmalloc(user_len + 1);
 936         if (buffer == NULL)
 937                 return ERR_PTR(-ENOMEM);
 938         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 939                 vfree(buffer);
 940                 return ERR_PTR(-EFAULT);
 941         }
 942         /* got the string, now strip linefeed. */
 943         if (buffer[user_len - 1] == '\n')
 944                 buffer[user_len - 1] = 0;
 945         else
 946                 buffer[user_len] = 0;
 947         return buffer;
 948 }
 949
 950 static ssize_t dasd_stats_write(struct file *file,
 951                                 const char __user *user_buf,
 952                                 size_t user_len, loff_t *pos)
 953 {
 954         char *buffer, *str;
 955         int rc;
 956         struct seq_file *m = (struct seq_file *)file->private_data;
 957         struct dasd_profile *prof = m->private;
 958
 959         if (user_len > 65536)
 960                 user_len = 65536;
 961         buffer = dasd_get_user_string(user_buf, user_len);
 962         if (IS_ERR(buffer))
 963                 return PTR_ERR(buffer);
 964
 965         str = skip_spaces(buffer);
 966         rc = user_len;
 967         if (strncmp(str, "reset", 5) == 0) {
 968                 dasd_profile_reset(prof);
 969         } else if (strncmp(str, "on", 2) == 0) {
 970                 rc = dasd_profile_on(prof);
 971                 if (rc)
 972                         goto out;
 973                 rc = user_len;
 974                 if (prof == &dasd_global_profile) {
 975                         dasd_profile_reset(prof);
 976                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 977                 }
 978         } else if (strncmp(str, "off", 3) == 0) {
 979                 if (prof == &dasd_global_profile)
 980                         dasd_global_profile_level = DASD_PROFILE_OFF;
 981                 dasd_profile_off(prof);
 982         } else
 983                 rc = -EINVAL;
 984 out:
 985         vfree(buffer);
 986         return rc;
 987 }
 988
 989 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 990 {
 991         int i;
 992
 993         for (i = 0; i < 32; i++)
 994                 seq_printf(m, "%u ", array[i]);
 995         seq_putc(m, '\n');
 996 }
 997
 998 static void dasd_stats_seq_print(struct seq_file *m,
 999                                  struct dasd_profile_info *data)
1000 {
1001         seq_printf(m, "start_time %ld.%09ld\n",
1002                    data->starttod.tv_sec, data->starttod.tv_nsec);
1003         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1004         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1005         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1006         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1007         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1008                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1009         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1010                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1011         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1012                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1013         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1014                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1015         seq_puts(m, "histogram_sectors ");
1016         dasd_stats_array(m, data->dasd_io_secs);
1017         seq_puts(m, "histogram_io_times ");
1018         dasd_stats_array(m, data->dasd_io_times);
1019         seq_puts(m, "histogram_io_times_weighted ");
1020         dasd_stats_array(m, data->dasd_io_timps);
1021         seq_puts(m, "histogram_time_build_to_ssch ");
1022         dasd_stats_array(m, data->dasd_io_time1);
1023         seq_puts(m, "histogram_time_ssch_to_irq ");
1024         dasd_stats_array(m, data->dasd_io_time2);
1025         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1026         dasd_stats_array(m, data->dasd_io_time2ps);
1027         seq_puts(m, "histogram_time_irq_to_end ");
1028         dasd_stats_array(m, data->dasd_io_time3);
1029         seq_puts(m, "histogram_ccw_queue_length ");
1030         dasd_stats_array(m, data->dasd_io_nr_req);
1031         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1032         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1033         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1034         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1035         seq_puts(m, "histogram_read_sectors ");
1036         dasd_stats_array(m, data->dasd_read_secs);
1037         seq_puts(m, "histogram_read_times ");
1038         dasd_stats_array(m, data->dasd_read_times);
1039         seq_puts(m, "histogram_read_time_build_to_ssch ");
1040         dasd_stats_array(m, data->dasd_read_time1);
1041         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1042         dasd_stats_array(m, data->dasd_read_time2);
1043         seq_puts(m, "histogram_read_time_irq_to_end ");
1044         dasd_stats_array(m, data->dasd_read_time3);
1045         seq_puts(m, "histogram_read_ccw_queue_length ");
1046         dasd_stats_array(m, data->dasd_read_nr_req);
1047 }
1048
1049 static int dasd_stats_show(struct seq_file *m, void *v)
1050 {
1051         struct dasd_profile *profile;
1052         struct dasd_profile_info *data;
1053
1054         profile = m->private;
1055         spin_lock_bh(&profile->lock);
1056         data = profile->data;
1057         if (!data) {
1058                 spin_unlock_bh(&profile->lock);
1059                 seq_puts(m, "disabled\n");
1060                 return 0;
1061         }
1062         dasd_stats_seq_print(m, data);
1063         spin_unlock_bh(&profile->lock);
1064         return 0;
1065 }
1066
1067 static int dasd_stats_open(struct inode *inode, struct file *file)
1068 {
1069         struct dasd_profile *profile = inode->i_private;
1070         return single_open(file, dasd_stats_show, profile);
1071 }
1072
1073 static const struct file_operations dasd_stats_raw_fops = {
1074         .owner          = THIS_MODULE,
1075         .open           = dasd_stats_open,
1076         .read           = seq_read,
1077         .llseek         = seq_lseek,
1078         .release        = single_release,
1079         .write          = dasd_stats_write,
1080 };
1081
1082 static void dasd_profile_init(struct dasd_profile *profile,
1083                               struct dentry *base_dentry)
1084 {
1085         umode_t mode;
1086         struct dentry *pde;
1087
1088         if (!base_dentry)
1089                 return;
1090         profile->dentry = NULL;
1091         profile->data = NULL;
1092         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1093         pde = debugfs_create_file("statistics", mode, base_dentry,
1094                                   profile, &dasd_stats_raw_fops);
1095         if (pde && !IS_ERR(pde))
1096                 profile->dentry = pde;
1097         return;
1098 }
1099
1100 static void dasd_profile_exit(struct dasd_profile *profile)
1101 {
1102         dasd_profile_off(profile);
1103         debugfs_remove(profile->dentry);
1104         profile->dentry = NULL;
1105 }
1106
1107 static void dasd_statistics_removeroot(void)
1108 {
1109         dasd_global_profile_level = DASD_PROFILE_OFF;
1110         dasd_profile_exit(&dasd_global_profile);
1111         debugfs_remove(dasd_debugfs_global_entry);
1112         debugfs_remove(dasd_debugfs_root_entry);
1113 }
1114
1115 static void dasd_statistics_createroot(void)
1116 {
1117         struct dentry *pde;
1118
1119         dasd_debugfs_root_entry = NULL;
1120         pde = debugfs_create_dir("dasd", NULL);
1121         if (!pde || IS_ERR(pde))
1122                 goto error;
1123         dasd_debugfs_root_entry = pde;
1124         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1125         if (!pde || IS_ERR(pde))
1126                 goto error;
1127         dasd_debugfs_global_entry = pde;
1128         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1129         return;
1130
1131 error:
1132         DBF_EVENT(DBF_ERR, "%s",
1133                   "Creation of the dasd debugfs interface failed");
1134         dasd_statistics_removeroot();
1135         return;
1136 }
1137
1138 #else
1139 #define dasd_profile_start(block, cqr, req) do {} while (0)
1140 #define dasd_profile_end(block, cqr, req) do {} while (0)
1141
1142 static void dasd_statistics_createroot(void)
1143 {
1144         return;
1145 }
1146
1147 static void dasd_statistics_removeroot(void)
1148 {
1149         return;
1150 }
1151
1152 int dasd_stats_generic_show(struct seq_file *m, void *v)
1153 {
1154         seq_puts(m, "Statistics are not activated in this kernel\n");
1155         return 0;
1156 }
1157
1158 static void dasd_profile_init(struct dasd_profile *profile,
1159                               struct dentry *base_dentry)
1160 {
1161         return;
1162 }
1163
1164 static void dasd_profile_exit(struct dasd_profile *profile)
1165 {
1166         return;
1167 }
1168
1169 int dasd_profile_on(struct dasd_profile *profile)
1170 {
1171         return 0;
1172 }
1173
1174 #endif                          /* CONFIG_DASD_PROFILE */
1175
1176 static int dasd_hosts_show(struct seq_file *m, void *v)
1177 {
1178         struct dasd_device *device;
1179         int rc = -EOPNOTSUPP;
1180
1181         device = m->private;
1182         dasd_get_device(device);
1183
1184         if (device->discipline->hosts_print)
1185                 rc = device->discipline->hosts_print(device, m);
1186
1187         dasd_put_device(device);
1188         return rc;
1189 }
1190
1191 static int dasd_hosts_open(struct inode *inode, struct file *file)
1192 {
1193         struct dasd_device *device = inode->i_private;
1194
1195         return single_open(file, dasd_hosts_show, device);
1196 }
1197
1198 static const struct file_operations dasd_hosts_fops = {
1199         .owner          = THIS_MODULE,
1200         .open           = dasd_hosts_open,
1201         .read           = seq_read,
1202         .llseek         = seq_lseek,
1203         .release        = single_release,
1204 };
1205
1206 static void dasd_hosts_exit(struct dasd_device *device)
1207 {
1208         debugfs_remove(device->hosts_dentry);
1209         device->hosts_dentry = NULL;
1210 }
1211
1212 static void dasd_hosts_init(struct dentry *base_dentry,
1213                             struct dasd_device *device)
1214 {
1215         struct dentry *pde;
1216         umode_t mode;
1217
1218         if (!base_dentry)
1219                 return;
1220
1221         mode = S_IRUSR | S_IFREG;
1222         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1223                                   device, &dasd_hosts_fops);
1224         if (pde && !IS_ERR(pde))
1225                 device->hosts_dentry = pde;
1226 }
1227
1228 /*
1229  * Allocate memory for a channel program with 'cplength' channel
1230  * command words and 'datasize' additional space. There are two
1231  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1232  * memory and 2) dasd_smalloc_request uses the static ccw memory
1233  * that gets allocated for each device.
1234  */
1235 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1236                                           int datasize,
1237                                           struct dasd_device *device)
1238 {
1239         struct dasd_ccw_req *cqr;
1240
1241         /* Sanity checks */
1242         BUG_ON(datasize > PAGE_SIZE ||
1243              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1244
1245         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1246         if (cqr == NULL)
1247                 return ERR_PTR(-ENOMEM);
1248         cqr->cpaddr = NULL;
1249         if (cplength > 0) {
1250                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1251                                       GFP_ATOMIC | GFP_DMA);
1252                 if (cqr->cpaddr == NULL) {
1253                         kfree(cqr);
1254                         return ERR_PTR(-ENOMEM);
1255                 }
1256         }
1257         cqr->data = NULL;
1258         if (datasize > 0) {
1259                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1260                 if (cqr->data == NULL) {
1261                         kfree(cqr->cpaddr);
1262                         kfree(cqr);
1263                         return ERR_PTR(-ENOMEM);
1264                 }
1265         }
1266         cqr->magic =  magic;
1267         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1268         dasd_get_device(device);
1269         return cqr;
1270 }
1271 EXPORT_SYMBOL(dasd_kmalloc_request);
1272
1273 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1274                                           int datasize,
1275                                           struct dasd_device *device)
1276 {
1277         unsigned long flags;
1278         struct dasd_ccw_req *cqr;
1279         char *data;
1280         int size;
1281
1282         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1283         if (cplength > 0)
1284                 size += cplength * sizeof(struct ccw1);
1285         if (datasize > 0)
1286                 size += datasize;
1287         spin_lock_irqsave(&device->mem_lock, flags);
1288         cqr = (struct dasd_ccw_req *)
1289                 dasd_alloc_chunk(&device->ccw_chunks, size);
1290         spin_unlock_irqrestore(&device->mem_lock, flags);
1291         if (cqr == NULL)
1292                 return ERR_PTR(-ENOMEM);
1293         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1294         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1295         cqr->cpaddr = NULL;
1296         if (cplength > 0) {
1297                 cqr->cpaddr = (struct ccw1 *) data;
1298                 data += cplength*sizeof(struct ccw1);
1299                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1300         }
1301         cqr->data = NULL;
1302         if (datasize > 0) {
1303                 cqr->data = data;
1304                 memset(cqr->data, 0, datasize);
1305         }
1306         cqr->magic = magic;
1307         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1308         dasd_get_device(device);
1309         return cqr;
1310 }
1311 EXPORT_SYMBOL(dasd_smalloc_request);
1312
1313 /*
1314  * Free memory of a channel program. This function needs to free all the
1315  * idal lists that might have been created by dasd_set_cda and the
1316  * struct dasd_ccw_req itself.
1317  */
1318 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1319 {
1320         struct ccw1 *ccw;
1321
1322         /* Clear any idals used for the request. */
1323         ccw = cqr->cpaddr;
1324         do {
1325                 clear_normalized_cda(ccw);
1326         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1327         kfree(cqr->cpaddr);
1328         kfree(cqr->data);
1329         kfree(cqr);
1330         dasd_put_device(device);
1331 }
1332 EXPORT_SYMBOL(dasd_kfree_request);
1333
1334 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1335 {
1336         unsigned long flags;
1337
1338         spin_lock_irqsave(&device->mem_lock, flags);
1339         dasd_free_chunk(&device->ccw_chunks, cqr);
1340         spin_unlock_irqrestore(&device->mem_lock, flags);
1341         dasd_put_device(device);
1342 }
1343 EXPORT_SYMBOL(dasd_sfree_request);
1344
1345 /*
1346  * Check discipline magic in cqr.
1347  */
1348 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1349 {
1350         struct dasd_device *device;
1351
1352         if (cqr == NULL)
1353                 return -EINVAL;
1354         device = cqr->startdev;
1355         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1356                 DBF_DEV_EVENT(DBF_WARNING, device,
1357                             " dasd_ccw_req 0x%08x magic doesn't match"
1358                             " discipline 0x%08x",
1359                             cqr->magic,
1360                             *(unsigned int *) device->discipline->name);
1361                 return -EINVAL;
1362         }
1363         return 0;
1364 }
1365
1366 /*
1367  * Terminate the current i/o and set the request to clear_pending.
1368  * Timer keeps device runnig.
1369  * ccw_device_clear can fail if the i/o subsystem
1370  * is in a bad mood.
1371  */
1372 int dasd_term_IO(struct dasd_ccw_req *cqr)
1373 {
1374         struct dasd_device *device;
1375         int retries, rc;
1376         char errorstring[ERRORLENGTH];
1377
1378         /* Check the cqr */
1379         rc = dasd_check_cqr(cqr);
1380         if (rc)
1381                 return rc;
1382         retries = 0;
1383         device = (struct dasd_device *) cqr->startdev;
1384         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1385                 rc = ccw_device_clear(device->cdev, (long) cqr);
1386                 switch (rc) {
1387                 case 0: /* termination successful */
1388                         cqr->status = DASD_CQR_CLEAR_PENDING;
1389                         cqr->stopclk = get_tod_clock();
1390                         cqr->starttime = 0;
1391                         DBF_DEV_EVENT(DBF_DEBUG, device,
1392                                       "terminate cqr %p successful",
1393                                       cqr);
1394                         break;
1395                 case -ENODEV:
1396                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1397                                       "device gone, retry");
1398                         break;
1399                 case -EIO:
1400                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1401                                       "I/O error, retry");
1402                         break;
1403                 case -EINVAL:
1404                         /*
1405                          * device not valid so no I/O could be running
1406                          * handle CQR as termination successful
1407                          */
1408                         cqr->status = DASD_CQR_CLEARED;
1409                         cqr->stopclk = get_tod_clock();
1410                         cqr->starttime = 0;
1411                         /* no retries for invalid devices */
1412                         cqr->retries = -1;
1413                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1414                                       "EINVAL, handle as terminated");
1415                         /* fake rc to success */
1416                         rc = 0;
1417                         break;
1418                 case -EBUSY:
1419                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1420                                       "device busy, retry later");
1421                         break;
1422                 default:
1423                         /* internal error 10 - unknown rc*/
1424                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1425                         dev_err(&device->cdev->dev, "An error occurred in the "
1426                                 "DASD device driver, reason=%s\n", errorstring);
1427                         BUG();
1428                         break;
1429                 }
1430                 retries++;
1431         }
1432         dasd_schedule_device_bh(device);
1433         return rc;
1434 }
1435 EXPORT_SYMBOL(dasd_term_IO);
1436
1437 /*
1438  * Start the i/o. This start_IO can fail if the channel is really busy.
1439  * In that case set up a timer to start the request later.
1440  */
1441 int dasd_start_IO(struct dasd_ccw_req *cqr)
1442 {
1443         struct dasd_device *device;
1444         int rc;
1445         char errorstring[ERRORLENGTH];
1446
1447         /* Check the cqr */
1448         rc = dasd_check_cqr(cqr);
1449         if (rc) {
1450                 cqr->intrc = rc;
1451                 return rc;
1452         }
1453         device = (struct dasd_device *) cqr->startdev;
1454         if (((cqr->block &&
1455               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1456              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1457             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1458                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1459                               "because of stolen lock", cqr);
1460                 cqr->status = DASD_CQR_ERROR;
1461                 cqr->intrc = -EPERM;
1462                 return -EPERM;
1463         }
1464         if (cqr->retries < 0) {
1465                 /* internal error 14 - start_IO run out of retries */
1466                 sprintf(errorstring, "14 %p", cqr);
1467                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1468                         "device driver, reason=%s\n", errorstring);
1469                 cqr->status = DASD_CQR_ERROR;
1470                 return -EIO;
1471         }
1472         cqr->startclk = get_tod_clock();
1473         cqr->starttime = jiffies;
1474         cqr->retries--;
1475         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1476                 cqr->lpm &= dasd_path_get_opm(device);
1477                 if (!cqr->lpm)
1478                         cqr->lpm = dasd_path_get_opm(device);
1479         }
1480         if (cqr->cpmode == 1) {
1481                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1482                                          (long) cqr, cqr->lpm);
1483         } else {
1484                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1485                                       (long) cqr, cqr->lpm, 0);
1486         }
1487         switch (rc) {
1488         case 0:
1489                 cqr->status = DASD_CQR_IN_IO;
1490                 break;
1491         case -EBUSY:
1492                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1493                               "start_IO: device busy, retry later");
1494                 break;
1495         case -ETIMEDOUT:
1496                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1497                               "start_IO: request timeout, retry later");
1498                 break;
1499         case -EACCES:
1500                 /* -EACCES indicates that the request used only a subset of the
1501                  * available paths and all these paths are gone. If the lpm of
1502                  * this request was only a subset of the opm (e.g. the ppm) then
1503                  * we just do a retry with all available paths.
1504                  * If we already use the full opm, something is amiss, and we
1505                  * need a full path verification.
1506                  */
1507                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1508                         DBF_DEV_EVENT(DBF_WARNING, device,
1509                                       "start_IO: selected paths gone (%x)",
1510                                       cqr->lpm);
1511                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1512                         cqr->lpm = dasd_path_get_opm(device);
1513                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1514                                       "start_IO: selected paths gone,"
1515                                       " retry on all paths");
1516                 } else {
1517                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1518                                       "start_IO: all paths in opm gone,"
1519                                       " do path verification");
1520                         dasd_generic_last_path_gone(device);
1521                         dasd_path_no_path(device);
1522                         dasd_path_set_tbvpm(device,
1523                                           ccw_device_get_path_mask(
1524                                                   device->cdev));
1525                 }
1526                 break;
1527         case -ENODEV:
1528                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1529                               "start_IO: -ENODEV device gone, retry");
1530                 break;
1531         case -EIO:
1532                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1533                               "start_IO: -EIO device gone, retry");
1534                 break;
1535         case -EINVAL:
1536                 /* most likely caused in power management context */
1537                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1538                               "start_IO: -EINVAL device currently "
1539                               "not accessible");
1540                 break;
1541         default:
1542                 /* internal error 11 - unknown rc */
1543                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1544                 dev_err(&device->cdev->dev,
1545                         "An error occurred in the DASD device driver, "
1546                         "reason=%s\n", errorstring);
1547                 BUG();
1548                 break;
1549         }
1550         cqr->intrc = rc;
1551         return rc;
1552 }
1553 EXPORT_SYMBOL(dasd_start_IO);
1554
1555 /*
1556  * Timeout function for dasd devices. This is used for different purposes
1557  *  1) missing interrupt handler for normal operation
1558  *  2) delayed start of request where start_IO failed with -EBUSY
1559  *  3) timeout for missing state change interrupts
1560  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1561  * DASD_CQR_QUEUED for 2) and 3).
1562  */
1563 static void dasd_device_timeout(unsigned long ptr)
1564 {
1565         unsigned long flags;
1566         struct dasd_device *device;
1567
1568         device = (struct dasd_device *) ptr;
1569         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1570         /* re-activate request queue */
1571         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1572         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1573         dasd_schedule_device_bh(device);
1574 }
1575
1576 /*
1577  * Setup timeout for a device in jiffies.
1578  */
1579 void dasd_device_set_timer(struct dasd_device *device, int expires)
1580 {
1581         if (expires == 0)
1582                 del_timer(&device->timer);
1583         else
1584                 mod_timer(&device->timer, jiffies + expires);
1585 }
1586 EXPORT_SYMBOL(dasd_device_set_timer);
1587
1588 /*
1589  * Clear timeout for a device.
1590  */
1591 void dasd_device_clear_timer(struct dasd_device *device)
1592 {
1593         del_timer(&device->timer);
1594 }
1595 EXPORT_SYMBOL(dasd_device_clear_timer);
1596
1597 static void dasd_handle_killed_request(struct ccw_device *cdev,
1598                                        unsigned long intparm)
1599 {
1600         struct dasd_ccw_req *cqr;
1601         struct dasd_device *device;
1602
1603         if (!intparm)
1604                 return;
1605         cqr = (struct dasd_ccw_req *) intparm;
1606         if (cqr->status != DASD_CQR_IN_IO) {
1607                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1608                                 "invalid status in handle_killed_request: "
1609                                 "%02x", cqr->status);
1610                 return;
1611         }
1612
1613         device = dasd_device_from_cdev_locked(cdev);
1614         if (IS_ERR(device)) {
1615                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1616                                 "unable to get device from cdev");
1617                 return;
1618         }
1619
1620         if (!cqr->startdev ||
1621             device != cqr->startdev ||
1622             strncmp(cqr->startdev->discipline->ebcname,
1623                     (char *) &cqr->magic, 4)) {
1624                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1625                                 "invalid device in request");
1626                 dasd_put_device(device);
1627                 return;
1628         }
1629
1630         /* Schedule request to be retried. */
1631         cqr->status = DASD_CQR_QUEUED;
1632
1633         dasd_device_clear_timer(device);
1634         dasd_schedule_device_bh(device);
1635         dasd_put_device(device);
1636 }
1637
1638 void dasd_generic_handle_state_change(struct dasd_device *device)
1639 {
1640         /* First of all start sense subsystem status request. */
1641         dasd_eer_snss(device);
1642
1643         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1644         dasd_schedule_device_bh(device);
1645         if (device->block) {
1646                 dasd_schedule_block_bh(device->block);
1647                 if (device->block->request_queue)
1648                         blk_mq_run_hw_queues(device->block->request_queue,
1649                                              true);
1650         }
1651 }
1652 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1653
1654 static int dasd_check_hpf_error(struct irb *irb)
1655 {
1656         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1657             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1658              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1659 }
1660
1661 /*
1662  * Interrupt handler for "normal" ssch-io based dasd devices.
1663  */
1664 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1665                       struct irb *irb)
1666 {
1667         struct dasd_ccw_req *cqr, *next;
1668         struct dasd_device *device;
1669         unsigned long now;
1670         int nrf_suppressed = 0;
1671         int fp_suppressed = 0;
1672         u8 *sense = NULL;
1673         int expires;
1674
1675         cqr = (struct dasd_ccw_req *) intparm;
1676         if (IS_ERR(irb)) {
1677                 switch (PTR_ERR(irb)) {
1678                 case -EIO:
1679                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1680                                 device = cqr->startdev;
1681                                 cqr->status = DASD_CQR_CLEARED;
1682                                 dasd_device_clear_timer(device);
1683                                 wake_up(&dasd_flush_wq);
1684                                 dasd_schedule_device_bh(device);
1685                                 return;
1686                         }
1687                         break;
1688                 case -ETIMEDOUT:
1689                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1690                                         "request timed out\n", __func__);
1691                         break;
1692                 default:
1693                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1694                                         "unknown error %ld\n", __func__,
1695                                         PTR_ERR(irb));
1696                 }
1697                 dasd_handle_killed_request(cdev, intparm);
1698                 return;
1699         }
1700
1701         now = get_tod_clock();
1702         /* check for conditions that should be handled immediately */
1703         if (!cqr ||
1704             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1705               scsw_cstat(&irb->scsw) == 0)) {
1706                 if (cqr)
1707                         memcpy(&cqr->irb, irb, sizeof(*irb));
1708                 device = dasd_device_from_cdev_locked(cdev);
1709                 if (IS_ERR(device))
1710                         return;
1711                 /* ignore unsolicited interrupts for DIAG discipline */
1712                 if (device->discipline == dasd_diag_discipline_pointer) {
1713                         dasd_put_device(device);
1714                         return;
1715                 }
1716
1717                 /*
1718                  * In some cases 'File Protected' or 'No Record Found' errors
1719                  * might be expected and debug log messages for the
1720                  * corresponding interrupts shouldn't be written then.
1721                  * Check if either of the according suppress bits is set.
1722                  */
1723                 sense = dasd_get_sense(irb);
1724                 if (sense) {
1725                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1726                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1727                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1728                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1729                 }
1730                 if (!(fp_suppressed || nrf_suppressed))
1731                         device->discipline->dump_sense_dbf(device, irb, "int");
1732
1733                 if (device->features & DASD_FEATURE_ERPLOG)
1734                         device->discipline->dump_sense(device, cqr, irb);
1735                 device->discipline->check_for_device_change(device, cqr, irb);
1736                 dasd_put_device(device);
1737         }
1738
1739         /* check for for attention message */
1740         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1741                 device = dasd_device_from_cdev_locked(cdev);
1742                 if (!IS_ERR(device)) {
1743                         device->discipline->check_attention(device,
1744                                                             irb->esw.esw1.lpum);
1745                         dasd_put_device(device);
1746                 }
1747         }
1748
1749         if (!cqr)
1750                 return;
1751
1752         device = (struct dasd_device *) cqr->startdev;
1753         if (!device ||
1754             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1755                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1756                                 "invalid device in request");
1757                 return;
1758         }
1759
1760         /* Check for clear pending */
1761         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1762             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1763                 cqr->status = DASD_CQR_CLEARED;
1764                 dasd_device_clear_timer(device);
1765                 wake_up(&dasd_flush_wq);
1766                 dasd_schedule_device_bh(device);
1767                 return;
1768         }
1769
1770         /* check status - the request might have been killed by dyn detach */
1771         if (cqr->status != DASD_CQR_IN_IO) {
1772                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1773                               "status %02x", dev_name(&cdev->dev), cqr->status);
1774                 return;
1775         }
1776
1777         next = NULL;
1778         expires = 0;
1779         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1780             scsw_cstat(&irb->scsw) == 0) {
1781                 /* request was completed successfully */
1782                 cqr->status = DASD_CQR_SUCCESS;
1783                 cqr->stopclk = now;
1784                 /* Start first request on queue if possible -> fast_io. */
1785                 if (cqr->devlist.next != &device->ccw_queue) {
1786                         next = list_entry(cqr->devlist.next,
1787                                           struct dasd_ccw_req, devlist);
1788                 }
1789         } else {  /* error */
1790                 /* check for HPF error
1791                  * call discipline function to requeue all requests
1792                  * and disable HPF accordingly
1793                  */
1794                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1795                     device->discipline->handle_hpf_error)
1796                         device->discipline->handle_hpf_error(device, irb);
1797                 /*
1798                  * If we don't want complex ERP for this request, then just
1799                  * reset this and retry it in the fastpath
1800                  */
1801                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1802                     cqr->retries > 0) {
1803                         if (cqr->lpm == dasd_path_get_opm(device))
1804                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1805                                               "default ERP in fastpath "
1806                                               "(%i retries left)",
1807                                               cqr->retries);
1808                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1809                                 cqr->lpm = dasd_path_get_opm(device);
1810                         cqr->status = DASD_CQR_QUEUED;
1811                         next = cqr;
1812                 } else
1813                         cqr->status = DASD_CQR_ERROR;
1814         }
1815         if (next && (next->status == DASD_CQR_QUEUED) &&
1816             (!device->stopped)) {
1817                 if (device->discipline->start_IO(next) == 0)
1818                         expires = next->expires;
1819         }
1820         if (expires != 0)
1821                 dasd_device_set_timer(device, expires);
1822         else
1823                 dasd_device_clear_timer(device);
1824         dasd_schedule_device_bh(device);
1825 }
1826 EXPORT_SYMBOL(dasd_int_handler);
1827
1828 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1829 {
1830         struct dasd_device *device;
1831
1832         device = dasd_device_from_cdev_locked(cdev);
1833
1834         if (IS_ERR(device))
1835                 goto out;
1836         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1837            device->state != device->target ||
1838            !device->discipline->check_for_device_change){
1839                 dasd_put_device(device);
1840                 goto out;
1841         }
1842         if (device->discipline->dump_sense_dbf)
1843                 device->discipline->dump_sense_dbf(device, irb, "uc");
1844         device->discipline->check_for_device_change(device, NULL, irb);
1845         dasd_put_device(device);
1846 out:
1847         return UC_TODO_RETRY;
1848 }
1849 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1850
1851 /*
1852  * If we have an error on a dasd_block layer request then we cancel
1853  * and return all further requests from the same dasd_block as well.
1854  */
1855 static void __dasd_device_recovery(struct dasd_device *device,
1856                                    struct dasd_ccw_req *ref_cqr)
1857 {
1858         struct list_head *l, *n;
1859         struct dasd_ccw_req *cqr;
1860
1861         /*
1862          * only requeue request that came from the dasd_block layer
1863          */
1864         if (!ref_cqr->block)
1865                 return;
1866
1867         list_for_each_safe(l, n, &device->ccw_queue) {
1868                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1869                 if (cqr->status == DASD_CQR_QUEUED &&
1870                     ref_cqr->block == cqr->block) {
1871                         cqr->status = DASD_CQR_CLEARED;
1872                 }
1873         }
1874 };
1875
1876 /*
1877  * Remove those ccw requests from the queue that need to be returned
1878  * to the upper layer.
1879  */
1880 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1881                                             struct list_head *final_queue)
1882 {
1883         struct list_head *l, *n;
1884         struct dasd_ccw_req *cqr;
1885
1886         /* Process request with final status. */
1887         list_for_each_safe(l, n, &device->ccw_queue) {
1888                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1889
1890                 /* Skip any non-final request. */
1891                 if (cqr->status == DASD_CQR_QUEUED ||
1892                     cqr->status == DASD_CQR_IN_IO ||
1893                     cqr->status == DASD_CQR_CLEAR_PENDING)
1894                         continue;
1895                 if (cqr->status == DASD_CQR_ERROR) {
1896                         __dasd_device_recovery(device, cqr);
1897                 }
1898                 /* Rechain finished requests to final queue */
1899                 list_move_tail(&cqr->devlist, final_queue);
1900         }
1901 }
1902
1903 /*
1904  * the cqrs from the final queue are returned to the upper layer
1905  * by setting a dasd_block state and calling the callback function
1906  */
1907 static void __dasd_device_process_final_queue(struct dasd_device *device,
1908                                               struct list_head *final_queue)
1909 {
1910         struct list_head *l, *n;
1911         struct dasd_ccw_req *cqr;
1912         struct dasd_block *block;
1913         void (*callback)(struct dasd_ccw_req *, void *data);
1914         void *callback_data;
1915         char errorstring[ERRORLENGTH];
1916
1917         list_for_each_safe(l, n, final_queue) {
1918                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1919                 list_del_init(&cqr->devlist);
1920                 block = cqr->block;
1921                 callback = cqr->callback;
1922                 callback_data = cqr->callback_data;
1923                 if (block)
1924                         spin_lock_bh(&block->queue_lock);
1925                 switch (cqr->status) {
1926                 case DASD_CQR_SUCCESS:
1927                         cqr->status = DASD_CQR_DONE;
1928                         break;
1929                 case DASD_CQR_ERROR:
1930                         cqr->status = DASD_CQR_NEED_ERP;
1931                         break;
1932                 case DASD_CQR_CLEARED:
1933                         cqr->status = DASD_CQR_TERMINATED;
1934                         break;
1935                 default:
1936                         /* internal error 12 - wrong cqr status*/
1937                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1938                         dev_err(&device->cdev->dev,
1939                                 "An error occurred in the DASD device driver, "
1940                                 "reason=%s\n", errorstring);
1941                         BUG();
1942                 }
1943                 if (cqr->callback != NULL)
1944                         (callback)(cqr, callback_data);
1945                 if (block)
1946                         spin_unlock_bh(&block->queue_lock);
1947         }
1948 }
1949
1950 /*
1951  * Take a look at the first request on the ccw queue and check
1952  * if it reached its expire time. If so, terminate the IO.
1953  */
1954 static void __dasd_device_check_expire(struct dasd_device *device)
1955 {
1956         struct dasd_ccw_req *cqr;
1957
1958         if (list_empty(&device->ccw_queue))
1959                 return;
1960         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1961         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1962             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1963                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1964                         /*
1965                          * IO in safe offline processing should not
1966                          * run out of retries
1967                          */
1968                         cqr->retries++;
1969                 }
1970                 if (device->discipline->term_IO(cqr) != 0) {
1971                         /* Hmpf, try again in 5 sec */
1972                         dev_err(&device->cdev->dev,
1973                                 "cqr %p timed out (%lus) but cannot be "
1974                                 "ended, retrying in 5 s\n",
1975                                 cqr, (cqr->expires/HZ));
1976                         cqr->expires += 5*HZ;
1977                         dasd_device_set_timer(device, 5*HZ);
1978                 } else {
1979                         dev_err(&device->cdev->dev,
1980                                 "cqr %p timed out (%lus), %i retries "
1981                                 "remaining\n", cqr, (cqr->expires/HZ),
1982                                 cqr->retries);
1983                 }
1984         }
1985 }
1986
1987 /*
1988  * return 1 when device is not eligible for IO
1989  */
1990 static int __dasd_device_is_unusable(struct dasd_device *device,
1991                                      struct dasd_ccw_req *cqr)
1992 {
1993         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1994
1995         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1996             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1997                 /*
1998                  * dasd is being set offline
1999                  * but it is no safe offline where we have to allow I/O
2000                  */
2001                 return 1;
2002         }
2003         if (device->stopped) {
2004                 if (device->stopped & mask) {
2005                         /* stopped and CQR will not change that. */
2006                         return 1;
2007                 }
2008                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2009                         /* CQR is not able to change device to
2010                          * operational. */
2011                         return 1;
2012                 }
2013                 /* CQR required to get device operational. */
2014         }
2015         return 0;
2016 }
2017
2018 /*
2019  * Take a look at the first request on the ccw queue and check
2020  * if it needs to be started.
2021  */
2022 static void __dasd_device_start_head(struct dasd_device *device)
2023 {
2024         struct dasd_ccw_req *cqr;
2025         int rc;
2026
2027         if (list_empty(&device->ccw_queue))
2028                 return;
2029         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2030         if (cqr->status != DASD_CQR_QUEUED)
2031                 return;
2032         /* if device is not usable return request to upper layer */
2033         if (__dasd_device_is_unusable(device, cqr)) {
2034                 cqr->intrc = -EAGAIN;
2035                 cqr->status = DASD_CQR_CLEARED;
2036                 dasd_schedule_device_bh(device);
2037                 return;
2038         }
2039
2040         rc = device->discipline->start_IO(cqr);
2041         if (rc == 0)
2042                 dasd_device_set_timer(device, cqr->expires);
2043         else if (rc == -EACCES) {
2044                 dasd_schedule_device_bh(device);
2045         } else
2046                 /* Hmpf, try again in 1/2 sec */
2047                 dasd_device_set_timer(device, 50);
2048 }
2049
2050 static void __dasd_device_check_path_events(struct dasd_device *device)
2051 {
2052         int rc;
2053
2054         if (!dasd_path_get_tbvpm(device))
2055                 return;
2056
2057         if (device->stopped &
2058             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2059                 return;
2060         rc = device->discipline->verify_path(device,
2061                                              dasd_path_get_tbvpm(device));
2062         if (rc)
2063                 dasd_device_set_timer(device, 50);
2064         else
2065                 dasd_path_clear_all_verify(device);
2066 };
2067
2068 /*
2069  * Go through all request on the dasd_device request queue,
2070  * terminate them on the cdev if necessary, and return them to the
2071  * submitting layer via callback.
2072  * Note:
2073  * Make sure that all 'submitting layers' still exist when
2074  * this function is called!. In other words, when 'device' is a base
2075  * device then all block layer requests must have been removed before
2076  * via dasd_flush_block_queue.
2077  */
2078 int dasd_flush_device_queue(struct dasd_device *device)
2079 {
2080         struct dasd_ccw_req *cqr, *n;
2081         int rc;
2082         struct list_head flush_queue;
2083
2084         INIT_LIST_HEAD(&flush_queue);
2085         spin_lock_irq(get_ccwdev_lock(device->cdev));
2086         rc = 0;
2087         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2088                 /* Check status and move request to flush_queue */
2089                 switch (cqr->status) {
2090                 case DASD_CQR_IN_IO:
2091                         rc = device->discipline->term_IO(cqr);
2092                         if (rc) {
2093                                 /* unable to terminate requeust */
2094                                 dev_err(&device->cdev->dev,
2095                                         "Flushing the DASD request queue "
2096                                         "failed for request %p\n", cqr);
2097                                 /* stop flush processing */
2098                                 goto finished;
2099                         }
2100                         break;
2101                 case DASD_CQR_QUEUED:
2102                         cqr->stopclk = get_tod_clock();
2103                         cqr->status = DASD_CQR_CLEARED;
2104                         break;
2105                 default: /* no need to modify the others */
2106                         break;
2107                 }
2108                 list_move_tail(&cqr->devlist, &flush_queue);
2109         }
2110 finished:
2111         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2112         /*
2113          * After this point all requests must be in state CLEAR_PENDING,
2114          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2115          * one of the others.
2116          */
2117         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2118                 wait_event(dasd_flush_wq,
2119                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2120         /*
2121          * Now set each request back to TERMINATED, DONE or NEED_ERP
2122          * and call the callback function of flushed requests
2123          */
2124         __dasd_device_process_final_queue(device, &flush_queue);
2125         return rc;
2126 }
2127 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2128
2129 /*
2130  * Acquire the device lock and process queues for the device.
2131  */
2132 static void dasd_device_tasklet(struct dasd_device *device)
2133 {
2134         struct list_head final_queue;
2135
2136         atomic_set (&device->tasklet_scheduled, 0);
2137         INIT_LIST_HEAD(&final_queue);
2138         spin_lock_irq(get_ccwdev_lock(device->cdev));
2139         /* Check expire time of first request on the ccw queue. */
2140         __dasd_device_check_expire(device);
2141         /* find final requests on ccw queue */
2142         __dasd_device_process_ccw_queue(device, &final_queue);
2143         __dasd_device_check_path_events(device);
2144         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2145         /* Now call the callback function of requests with final status */
2146         __dasd_device_process_final_queue(device, &final_queue);
2147         spin_lock_irq(get_ccwdev_lock(device->cdev));
2148         /* Now check if the head of the ccw queue needs to be started. */
2149         __dasd_device_start_head(device);
2150         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2151         if (waitqueue_active(&shutdown_waitq))
2152                 wake_up(&shutdown_waitq);
2153         dasd_put_device(device);
2154 }
2155
2156 /*
2157  * Schedules a call to dasd_tasklet over the device tasklet.
2158  */
2159 void dasd_schedule_device_bh(struct dasd_device *device)
2160 {
2161         /* Protect against rescheduling. */
2162         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2163                 return;
2164         dasd_get_device(device);
2165         tasklet_hi_schedule(&device->tasklet);
2166 }
2167 EXPORT_SYMBOL(dasd_schedule_device_bh);
2168
2169 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2170 {
2171         device->stopped |= bits;
2172 }
2173 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2174
2175 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2176 {
2177         device->stopped &= ~bits;
2178         if (!device->stopped)
2179                 wake_up(&generic_waitq);
2180 }
2181 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2182
2183 /*
2184  * Queue a request to the head of the device ccw_queue.
2185  * Start the I/O if possible.
2186  */
2187 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2188 {
2189         struct dasd_device *device;
2190         unsigned long flags;
2191
2192         device = cqr->startdev;
2193         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2194         cqr->status = DASD_CQR_QUEUED;
2195         list_add(&cqr->devlist, &device->ccw_queue);
2196         /* let the bh start the request to keep them in order */
2197         dasd_schedule_device_bh(device);
2198         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2199 }
2200 EXPORT_SYMBOL(dasd_add_request_head);
2201
2202 /*
2203  * Queue a request to the tail of the device ccw_queue.
2204  * Start the I/O if possible.
2205  */
2206 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2207 {
2208         struct dasd_device *device;
2209         unsigned long flags;
2210
2211         device = cqr->startdev;
2212         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2213         cqr->status = DASD_CQR_QUEUED;
2214         list_add_tail(&cqr->devlist, &device->ccw_queue);
2215         /* let the bh start the request to keep them in order */
2216         dasd_schedule_device_bh(device);
2217         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2218 }
2219 EXPORT_SYMBOL(dasd_add_request_tail);
2220
2221 /*
2222  * Wakeup helper for the 'sleep_on' functions.
2223  */
2224 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2225 {
2226         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2227         cqr->callback_data = DASD_SLEEPON_END_TAG;
2228         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2229         wake_up(&generic_waitq);
2230 }
2231 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2232
2233 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2234 {
2235         struct dasd_device *device;
2236         int rc;
2237
2238         device = cqr->startdev;
2239         spin_lock_irq(get_ccwdev_lock(device->cdev));
2240         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2241         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2242         return rc;
2243 }
2244
2245 /*
2246  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2247  */
2248 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2249 {
2250         struct dasd_device *device;
2251         dasd_erp_fn_t erp_fn;
2252
2253         if (cqr->status == DASD_CQR_FILLED)
2254                 return 0;
2255         device = cqr->startdev;
2256         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2257                 if (cqr->status == DASD_CQR_TERMINATED) {
2258                         device->discipline->handle_terminated_request(cqr);
2259                         return 1;
2260                 }
2261                 if (cqr->status == DASD_CQR_NEED_ERP) {
2262                         erp_fn = device->discipline->erp_action(cqr);
2263                         erp_fn(cqr);
2264                         return 1;
2265                 }
2266                 if (cqr->status == DASD_CQR_FAILED)
2267                         dasd_log_sense(cqr, &cqr->irb);
2268                 if (cqr->refers) {
2269                         __dasd_process_erp(device, cqr);
2270                         return 1;
2271                 }
2272         }
2273         return 0;
2274 }
2275
2276 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2277 {
2278         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2279                 if (cqr->refers) /* erp is not done yet */
2280                         return 1;
2281                 return ((cqr->status != DASD_CQR_DONE) &&
2282                         (cqr->status != DASD_CQR_FAILED));
2283         } else
2284                 return (cqr->status == DASD_CQR_FILLED);
2285 }
2286
2287 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2288 {
2289         struct dasd_device *device;
2290         int rc;
2291         struct list_head ccw_queue;
2292         struct dasd_ccw_req *cqr;
2293
2294         INIT_LIST_HEAD(&ccw_queue);
2295         maincqr->status = DASD_CQR_FILLED;
2296         device = maincqr->startdev;
2297         list_add(&maincqr->blocklist, &ccw_queue);
2298         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2299              cqr = list_first_entry(&ccw_queue,
2300                                     struct dasd_ccw_req, blocklist)) {
2301
2302                 if (__dasd_sleep_on_erp(cqr))
2303                         continue;
2304                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2305                         continue;
2306                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2307                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2308                         cqr->status = DASD_CQR_FAILED;
2309                         cqr->intrc = -EPERM;
2310                         continue;
2311                 }
2312                 /* Non-temporary stop condition will trigger fail fast */
2313                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2314                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2315                     (!dasd_eer_enabled(device))) {
2316                         cqr->status = DASD_CQR_FAILED;
2317                         cqr->intrc = -ENOLINK;
2318                         continue;
2319                 }
2320                 /*
2321                  * Don't try to start requests if device is in
2322                  * offline processing, it might wait forever
2323                  */
2324                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2325                         cqr->status = DASD_CQR_FAILED;
2326                         cqr->intrc = -ENODEV;
2327                         continue;
2328                 }
2329                 /*
2330                  * Don't try to start requests if device is stopped
2331                  * except path verification requests
2332                  */
2333                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2334                         if (interruptible) {
2335                                 rc = wait_event_interruptible(
2336                                         generic_waitq, !(device->stopped));
2337                                 if (rc == -ERESTARTSYS) {
2338                                         cqr->status = DASD_CQR_FAILED;
2339                                         maincqr->intrc = rc;
2340                                         continue;
2341                                 }
2342                         } else
2343                                 wait_event(generic_waitq, !(device->stopped));
2344                 }
2345                 if (!cqr->callback)
2346                         cqr->callback = dasd_wakeup_cb;
2347
2348                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2349                 dasd_add_request_tail(cqr);
2350                 if (interruptible) {
2351                         rc = wait_event_interruptible(
2352                                 generic_waitq, _wait_for_wakeup(cqr));
2353                         if (rc == -ERESTARTSYS) {
2354                                 dasd_cancel_req(cqr);
2355                                 /* wait (non-interruptible) for final status */
2356                                 wait_event(generic_waitq,
2357                                            _wait_for_wakeup(cqr));
2358                                 cqr->status = DASD_CQR_FAILED;
2359                                 maincqr->intrc = rc;
2360                                 continue;
2361                         }
2362                 } else
2363                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2364         }
2365
2366         maincqr->endclk = get_tod_clock();
2367         if ((maincqr->status != DASD_CQR_DONE) &&
2368             (maincqr->intrc != -ERESTARTSYS))
2369                 dasd_log_sense(maincqr, &maincqr->irb);
2370         if (maincqr->status == DASD_CQR_DONE)
2371                 rc = 0;
2372         else if (maincqr->intrc)
2373                 rc = maincqr->intrc;
2374         else
2375                 rc = -EIO;
2376         return rc;
2377 }
2378
2379 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2380 {
2381         struct dasd_ccw_req *cqr;
2382
2383         list_for_each_entry(cqr, ccw_queue, blocklist) {
2384                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2385                         return 0;
2386         }
2387
2388         return 1;
2389 }
2390
2391 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2392 {
2393         struct dasd_device *device;
2394         struct dasd_ccw_req *cqr, *n;
2395         u8 *sense = NULL;
2396         int rc;
2397
2398 retry:
2399         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2400                 device = cqr->startdev;
2401                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2402                         continue;
2403
2404                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2405                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2406                         cqr->status = DASD_CQR_FAILED;
2407                         cqr->intrc = -EPERM;
2408                         continue;
2409                 }
2410                 /*Non-temporary stop condition will trigger fail fast*/
2411                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2412                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2413                     !dasd_eer_enabled(device)) {
2414                         cqr->status = DASD_CQR_FAILED;
2415                         cqr->intrc = -EAGAIN;
2416                         continue;
2417                 }
2418
2419                 /*Don't try to start requests if device is stopped*/
2420                 if (interruptible) {
2421                         rc = wait_event_interruptible(
2422                                 generic_waitq, !device->stopped);
2423                         if (rc == -ERESTARTSYS) {
2424                                 cqr->status = DASD_CQR_FAILED;
2425                                 cqr->intrc = rc;
2426                                 continue;
2427                         }
2428                 } else
2429                         wait_event(generic_waitq, !(device->stopped));
2430
2431                 if (!cqr->callback)
2432                         cqr->callback = dasd_wakeup_cb;
2433                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2434                 dasd_add_request_tail(cqr);
2435         }
2436
2437         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2438
2439         rc = 0;
2440         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2441                 /*
2442                  * In some cases the 'File Protected' or 'Incorrect Length'
2443                  * error might be expected and error recovery would be
2444                  * unnecessary in these cases.  Check if the according suppress
2445                  * bit is set.
2446                  */
2447                 sense = dasd_get_sense(&cqr->irb);
2448                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2449                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2450                         continue;
2451                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2452                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2453                         continue;
2454
2455                 /*
2456                  * for alias devices simplify error recovery and
2457                  * return to upper layer
2458                  * do not skip ERP requests
2459                  */
2460                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2461                     (cqr->status == DASD_CQR_TERMINATED ||
2462                      cqr->status == DASD_CQR_NEED_ERP))
2463                         return -EAGAIN;
2464
2465                 /* normal recovery for basedev IO */
2466                 if (__dasd_sleep_on_erp(cqr))
2467                         /* handle erp first */
2468                         goto retry;
2469         }
2470
2471         return 0;
2472 }
2473
2474 /*
2475  * Queue a request to the tail of the device ccw_queue and wait for
2476  * it's completion.
2477  */
2478 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2479 {
2480         return _dasd_sleep_on(cqr, 0);
2481 }
2482 EXPORT_SYMBOL(dasd_sleep_on);
2483
2484 /*
2485  * Start requests from a ccw_queue and wait for their completion.
2486  */
2487 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2488 {
2489         return _dasd_sleep_on_queue(ccw_queue, 0);
2490 }
2491 EXPORT_SYMBOL(dasd_sleep_on_queue);
2492
2493 /*
2494  * Queue a request to the tail of the device ccw_queue and wait
2495  * interruptible for it's completion.
2496  */
2497 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2498 {
2499         return _dasd_sleep_on(cqr, 1);
2500 }
2501 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2502
2503 /*
2504  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2505  * for eckd devices) the currently running request has to be terminated
2506  * and be put back to status queued, before the special request is added
2507  * to the head of the queue. Then the special request is waited on normally.
2508  */
2509 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2510 {
2511         struct dasd_ccw_req *cqr;
2512         int rc;
2513
2514         if (list_empty(&device->ccw_queue))
2515                 return 0;
2516         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2517         rc = device->discipline->term_IO(cqr);
2518         if (!rc)
2519                 /*
2520                  * CQR terminated because a more important request is pending.
2521                  * Undo decreasing of retry counter because this is
2522                  * not an error case.
2523                  */
2524                 cqr->retries++;
2525         return rc;
2526 }
2527
2528 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2529 {
2530         struct dasd_device *device;
2531         int rc;
2532
2533         device = cqr->startdev;
2534         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2535             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2536                 cqr->status = DASD_CQR_FAILED;
2537                 cqr->intrc = -EPERM;
2538                 return -EIO;
2539         }
2540         spin_lock_irq(get_ccwdev_lock(device->cdev));
2541         rc = _dasd_term_running_cqr(device);
2542         if (rc) {
2543                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2544                 return rc;
2545         }
2546         cqr->callback = dasd_wakeup_cb;
2547         cqr->callback_data = DASD_SLEEPON_START_TAG;
2548         cqr->status = DASD_CQR_QUEUED;
2549         /*
2550          * add new request as second
2551          * first the terminated cqr needs to be finished
2552          */
2553         list_add(&cqr->devlist, device->ccw_queue.next);
2554
2555         /* let the bh start the request to keep them in order */
2556         dasd_schedule_device_bh(device);
2557
2558         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2559
2560         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2561
2562         if (cqr->status == DASD_CQR_DONE)
2563                 rc = 0;
2564         else if (cqr->intrc)
2565                 rc = cqr->intrc;
2566         else
2567                 rc = -EIO;
2568
2569         /* kick tasklets */
2570         dasd_schedule_device_bh(device);
2571         if (device->block)
2572                 dasd_schedule_block_bh(device->block);
2573
2574         return rc;
2575 }
2576 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2577
2578 /*
2579  * Cancels a request that was started with dasd_sleep_on_req.
2580  * This is useful to timeout requests. The request will be
2581  * terminated if it is currently in i/o.
2582  * Returns 0 if request termination was successful
2583  *         negative error code if termination failed
2584  * Cancellation of a request is an asynchronous operation! The calling
2585  * function has to wait until the request is properly returned via callback.
2586  */
2587 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2588 {
2589         struct dasd_device *device = cqr->startdev;
2590         unsigned long flags;
2591         int rc;
2592
2593         rc = 0;
2594         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2595         switch (cqr->status) {
2596         case DASD_CQR_QUEUED:
2597                 /* request was not started - just set to cleared */
2598                 cqr->status = DASD_CQR_CLEARED;
2599                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2600                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2601                 break;
2602         case DASD_CQR_IN_IO:
2603                 /* request in IO - terminate IO and release again */
2604                 rc = device->discipline->term_IO(cqr);
2605                 if (rc) {
2606                         dev_err(&device->cdev->dev,
2607                                 "Cancelling request %p failed with rc=%d\n",
2608                                 cqr, rc);
2609                 } else {
2610                         cqr->stopclk = get_tod_clock();
2611                 }
2612                 break;
2613         default: /* already finished or clear pending - do nothing */
2614                 break;
2615         }
2616         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2617         dasd_schedule_device_bh(device);
2618         return rc;
2619 }
2620 EXPORT_SYMBOL(dasd_cancel_req);
2621
2622 /*
2623  * SECTION: Operations of the dasd_block layer.
2624  */
2625
2626 /*
2627  * Timeout function for dasd_block. This is used when the block layer
2628  * is waiting for something that may not come reliably, (e.g. a state
2629  * change interrupt)
2630  */
2631 static void dasd_block_timeout(unsigned long ptr)
2632 {
2633         unsigned long flags;
2634         struct dasd_block *block;
2635
2636         block = (struct dasd_block *) ptr;
2637         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2638         /* re-activate request queue */
2639         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2640         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2641         dasd_schedule_block_bh(block);
2642         blk_mq_run_hw_queues(block->request_queue, true);
2643 }
2644
2645 /*
2646  * Setup timeout for a dasd_block in jiffies.
2647  */
2648 void dasd_block_set_timer(struct dasd_block *block, int expires)
2649 {
2650         if (expires == 0)
2651                 del_timer(&block->timer);
2652         else
2653                 mod_timer(&block->timer, jiffies + expires);
2654 }
2655 EXPORT_SYMBOL(dasd_block_set_timer);
2656
2657 /*
2658  * Clear timeout for a dasd_block.
2659  */
2660 void dasd_block_clear_timer(struct dasd_block *block)
2661 {
2662         del_timer(&block->timer);
2663 }
2664 EXPORT_SYMBOL(dasd_block_clear_timer);
2665
2666 /*
2667  * Process finished error recovery ccw.
2668  */
2669 static void __dasd_process_erp(struct dasd_device *device,
2670                                struct dasd_ccw_req *cqr)
2671 {
2672         dasd_erp_fn_t erp_fn;
2673
2674         if (cqr->status == DASD_CQR_DONE)
2675                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2676         else
2677                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2678         erp_fn = device->discipline->erp_postaction(cqr);
2679         erp_fn(cqr);
2680 }
2681
2682 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2683 {
2684         struct request *req;
2685         blk_status_t error = BLK_STS_OK;
2686         int status;
2687
2688         req = (struct request *) cqr->callback_data;
2689         dasd_profile_end(cqr->block, cqr, req);
2690
2691         status = cqr->block->base->discipline->free_cp(cqr, req);
2692         if (status < 0)
2693                 error = errno_to_blk_status(status);
2694         else if (status == 0) {
2695                 switch (cqr->intrc) {
2696                 case -EPERM:
2697                         error = BLK_STS_NEXUS;
2698                         break;
2699                 case -ENOLINK:
2700                         error = BLK_STS_TRANSPORT;
2701                         break;
2702                 case -ETIMEDOUT:
2703                         error = BLK_STS_TIMEOUT;
2704                         break;
2705                 default:
2706                         error = BLK_STS_IOERR;
2707                         break;
2708                 }
2709         }
2710
2711         /*
2712          * We need to take care for ETIMEDOUT errors here since the
2713          * complete callback does not get called in this case.
2714          * Take care of all errors here and avoid additional code to
2715          * transfer the error value to the complete callback.
2716          */
2717         if (error) {
2718                 blk_mq_end_request(req, error);
2719                 blk_mq_run_hw_queues(req->q, true);
2720         } else {
2721                 blk_mq_complete_request(req);
2722         }
2723 }
2724
2725 /*
2726  * Process ccw request queue.
2727  */
2728 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2729                                            struct list_head *final_queue)
2730 {
2731         struct list_head *l, *n;
2732         struct dasd_ccw_req *cqr;
2733         dasd_erp_fn_t erp_fn;
2734         unsigned long flags;
2735         struct dasd_device *base = block->base;
2736
2737 restart:
2738         /* Process request with final status. */
2739         list_for_each_safe(l, n, &block->ccw_queue) {
2740                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2741                 if (cqr->status != DASD_CQR_DONE &&
2742                     cqr->status != DASD_CQR_FAILED &&
2743                     cqr->status != DASD_CQR_NEED_ERP &&
2744                     cqr->status != DASD_CQR_TERMINATED)
2745                         continue;
2746
2747                 if (cqr->status == DASD_CQR_TERMINATED) {
2748                         base->discipline->handle_terminated_request(cqr);
2749                         goto restart;
2750                 }
2751
2752                 /*  Process requests that may be recovered */
2753                 if (cqr->status == DASD_CQR_NEED_ERP) {
2754                         erp_fn = base->discipline->erp_action(cqr);
2755                         if (IS_ERR(erp_fn(cqr)))
2756                                 continue;
2757                         goto restart;
2758                 }
2759
2760                 /* log sense for fatal error */
2761                 if (cqr->status == DASD_CQR_FAILED) {
2762                         dasd_log_sense(cqr, &cqr->irb);
2763                 }
2764
2765                 /* First of all call extended error reporting. */
2766                 if (dasd_eer_enabled(base) &&
2767                     cqr->status == DASD_CQR_FAILED) {
2768                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2769
2770                         /* restart request  */
2771                         cqr->status = DASD_CQR_FILLED;
2772                         cqr->retries = 255;
2773                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2774                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2775                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2776                                                flags);
2777                         goto restart;
2778                 }
2779
2780                 /* Process finished ERP request. */
2781                 if (cqr->refers) {
2782                         __dasd_process_erp(base, cqr);
2783                         goto restart;
2784                 }
2785
2786                 /* Rechain finished requests to final queue */
2787                 cqr->endclk = get_tod_clock();
2788                 list_move_tail(&cqr->blocklist, final_queue);
2789         }
2790 }
2791
2792 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2793 {
2794         dasd_schedule_block_bh(cqr->block);
2795 }
2796
2797 static void __dasd_block_start_head(struct dasd_block *block)
2798 {
2799         struct dasd_ccw_req *cqr;
2800
2801         if (list_empty(&block->ccw_queue))
2802                 return;
2803         /* We allways begin with the first requests on the queue, as some
2804          * of previously started requests have to be enqueued on a
2805          * dasd_device again for error recovery.
2806          */
2807         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2808                 if (cqr->status != DASD_CQR_FILLED)
2809                         continue;
2810                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2811                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2812                         cqr->status = DASD_CQR_FAILED;
2813                         cqr->intrc = -EPERM;
2814                         dasd_schedule_block_bh(block);
2815                         continue;
2816                 }
2817                 /* Non-temporary stop condition will trigger fail fast */
2818                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2819                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2820                     (!dasd_eer_enabled(block->base))) {
2821                         cqr->status = DASD_CQR_FAILED;
2822                         cqr->intrc = -ENOLINK;
2823                         dasd_schedule_block_bh(block);
2824                         continue;
2825                 }
2826                 /* Don't try to start requests if device is stopped */
2827                 if (block->base->stopped)
2828                         return;
2829
2830                 /* just a fail safe check, should not happen */
2831                 if (!cqr->startdev)
2832                         cqr->startdev = block->base;
2833
2834                 /* make sure that the requests we submit find their way back */
2835                 cqr->callback = dasd_return_cqr_cb;
2836
2837                 dasd_add_request_tail(cqr);
2838         }
2839 }
2840
2841 /*
2842  * Central dasd_block layer routine. Takes requests from the generic
2843  * block layer request queue, creates ccw requests, enqueues them on
2844  * a dasd_device and processes ccw requests that have been returned.
2845  */
2846 static void dasd_block_tasklet(struct dasd_block *block)
2847 {
2848         struct list_head final_queue;
2849         struct list_head *l, *n;
2850         struct dasd_ccw_req *cqr;
2851         struct dasd_queue *dq;
2852
2853         atomic_set(&block->tasklet_scheduled, 0);
2854         INIT_LIST_HEAD(&final_queue);
2855         spin_lock_irq(&block->queue_lock);
2856         /* Finish off requests on ccw queue */
2857         __dasd_process_block_ccw_queue(block, &final_queue);
2858         spin_unlock_irq(&block->queue_lock);
2859
2860         /* Now call the callback function of requests with final status */
2861         list_for_each_safe(l, n, &final_queue) {
2862                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2863                 dq = cqr->dq;
2864                 spin_lock_irq(&dq->lock);
2865                 list_del_init(&cqr->blocklist);
2866                 __dasd_cleanup_cqr(cqr);
2867                 spin_unlock_irq(&dq->lock);
2868         }
2869
2870         spin_lock_irq(&block->queue_lock);
2871         /* Now check if the head of the ccw queue needs to be started. */
2872         __dasd_block_start_head(block);
2873         spin_unlock_irq(&block->queue_lock);
2874
2875         if (waitqueue_active(&shutdown_waitq))
2876                 wake_up(&shutdown_waitq);
2877         dasd_put_device(block->base);
2878 }
2879
2880 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2881 {
2882         wake_up(&dasd_flush_wq);
2883 }
2884
2885 /*
2886  * Requeue a request back to the block request queue
2887  * only works for block requests
2888  */
2889 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2890 {
2891         struct dasd_block *block = cqr->block;
2892         struct request *req;
2893
2894         if (!block)
2895                 return -EINVAL;
2896         spin_lock_irq(&cqr->dq->lock);
2897         req = (struct request *) cqr->callback_data;
2898         blk_mq_requeue_request(req, false);
2899         spin_unlock_irq(&cqr->dq->lock);
2900
2901         return 0;
2902 }
2903
2904 /*
2905  * Go through all request on the dasd_block request queue, cancel them
2906  * on the respective dasd_device, and return them to the generic
2907  * block layer.
2908  */
2909 static int dasd_flush_block_queue(struct dasd_block *block)
2910 {
2911         struct dasd_ccw_req *cqr, *n;
2912         int rc, i;
2913         struct list_head flush_queue;
2914         unsigned long flags;
2915
2916         INIT_LIST_HEAD(&flush_queue);
2917         spin_lock_bh(&block->queue_lock);
2918         rc = 0;
2919 restart:
2920         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2921                 /* if this request currently owned by a dasd_device cancel it */
2922                 if (cqr->status >= DASD_CQR_QUEUED)
2923                         rc = dasd_cancel_req(cqr);
2924                 if (rc < 0)
2925                         break;
2926                 /* Rechain request (including erp chain) so it won't be
2927                  * touched by the dasd_block_tasklet anymore.
2928                  * Replace the callback so we notice when the request
2929                  * is returned from the dasd_device layer.
2930                  */
2931                 cqr->callback = _dasd_wake_block_flush_cb;
2932                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2933                         list_move_tail(&cqr->blocklist, &flush_queue);
2934                 if (i > 1)
2935                         /* moved more than one request - need to restart */
2936                         goto restart;
2937         }
2938         spin_unlock_bh(&block->queue_lock);
2939         /* Now call the callback function of flushed requests */
2940 restart_cb:
2941         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2942                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2943                 /* Process finished ERP request. */
2944                 if (cqr->refers) {
2945                         spin_lock_bh(&block->queue_lock);
2946                         __dasd_process_erp(block->base, cqr);
2947                         spin_unlock_bh(&block->queue_lock);
2948                         /* restart list_for_xx loop since dasd_process_erp
2949                          * might remove multiple elements */
2950                         goto restart_cb;
2951                 }
2952                 /* call the callback function */
2953                 spin_lock_irqsave(&cqr->dq->lock, flags);
2954                 cqr->endclk = get_tod_clock();
2955                 list_del_init(&cqr->blocklist);
2956                 __dasd_cleanup_cqr(cqr);
2957                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
2958         }
2959         return rc;
2960 }
2961
2962 /*
2963  * Schedules a call to dasd_tasklet over the device tasklet.
2964  */
2965 void dasd_schedule_block_bh(struct dasd_block *block)
2966 {
2967         /* Protect against rescheduling. */
2968         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2969                 return;
2970         /* life cycle of block is bound to it's base device */
2971         dasd_get_device(block->base);
2972         tasklet_hi_schedule(&block->tasklet);
2973 }
2974 EXPORT_SYMBOL(dasd_schedule_block_bh);
2975
2976
2977 /*
2978  * SECTION: external block device operations
2979  * (request queue handling, open, release, etc.)
2980  */
2981
2982 /*
2983  * Dasd request queue function. Called from ll_rw_blk.c
2984  */
2985 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
2986                                     const struct blk_mq_queue_data *qd)
2987 {
2988         struct dasd_block *block = hctx->queue->queuedata;
2989         struct dasd_queue *dq = hctx->driver_data;
2990         struct request *req = qd->rq;
2991         struct dasd_device *basedev;
2992         struct dasd_ccw_req *cqr;
2993         blk_status_t rc = BLK_STS_OK;
2994
2995         basedev = block->base;
2996         spin_lock_irq(&dq->lock);
2997         if (basedev->state < DASD_STATE_READY) {
2998                 DBF_DEV_EVENT(DBF_ERR, basedev,
2999                               "device not ready for request %p", req);
3000                 rc = BLK_STS_IOERR;
3001                 goto out;
3002         }
3003
3004         /*
3005          * if device is stopped do not fetch new requests
3006          * except failfast is active which will let requests fail
3007          * immediately in __dasd_block_start_head()
3008          */
3009         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3010                 DBF_DEV_EVENT(DBF_ERR, basedev,
3011                               "device stopped request %p", req);
3012                 rc = BLK_STS_RESOURCE;
3013                 goto out;
3014         }
3015
3016         if (basedev->features & DASD_FEATURE_READONLY &&
3017             rq_data_dir(req) == WRITE) {
3018                 DBF_DEV_EVENT(DBF_ERR, basedev,
3019                               "Rejecting write request %p", req);
3020                 rc = BLK_STS_IOERR;
3021                 goto out;
3022         }
3023
3024         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3025             (basedev->features & DASD_FEATURE_FAILFAST ||
3026              blk_noretry_request(req))) {
3027                 DBF_DEV_EVENT(DBF_ERR, basedev,
3028                               "Rejecting failfast request %p", req);
3029                 rc = BLK_STS_IOERR;
3030                 goto out;
3031         }
3032
3033         cqr = basedev->discipline->build_cp(basedev, block, req);
3034         if (IS_ERR(cqr)) {
3035                 if (PTR_ERR(cqr) == -EBUSY ||
3036                     PTR_ERR(cqr) == -ENOMEM ||
3037                     PTR_ERR(cqr) == -EAGAIN) {
3038                         rc = BLK_STS_RESOURCE;
3039                         goto out;
3040                 }
3041                 DBF_DEV_EVENT(DBF_ERR, basedev,
3042                               "CCW creation failed (rc=%ld) on request %p",
3043                               PTR_ERR(cqr), req);
3044                 rc = BLK_STS_IOERR;
3045                 goto out;
3046         }
3047         /*
3048          *  Note: callback is set to dasd_return_cqr_cb in
3049          * __dasd_block_start_head to cover erp requests as well
3050          */
3051         cqr->callback_data = req;
3052         cqr->status = DASD_CQR_FILLED;
3053         cqr->dq = dq;
3054         req->completion_data = cqr;
3055         blk_mq_start_request(req);
3056         spin_lock(&block->queue_lock);
3057         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3058         INIT_LIST_HEAD(&cqr->devlist);
3059         dasd_profile_start(block, cqr, req);
3060         dasd_schedule_block_bh(block);
3061         spin_unlock(&block->queue_lock);
3062
3063 out:
3064         spin_unlock_irq(&dq->lock);
3065         return rc;
3066 }
3067
3068 /*
3069  * Block timeout callback, called from the block layer
3070  *
3071  * Return values:
3072  * BLK_EH_RESET_TIMER if the request should be left running
3073  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3074  *                    by the driver.
3075  */
3076 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3077 {
3078         struct dasd_ccw_req *cqr = req->completion_data;
3079         struct dasd_block *block = req->q->queuedata;
3080         struct dasd_device *device;
3081         unsigned long flags;
3082         int rc = 0;
3083
3084         if (!cqr)
3085                 return BLK_EH_NOT_HANDLED;
3086
3087         spin_lock_irqsave(&cqr->dq->lock, flags);
3088         device = cqr->startdev ? cqr->startdev : block->base;
3089         if (!device->blk_timeout) {
3090                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3091                 return BLK_EH_RESET_TIMER;
3092         }
3093         DBF_DEV_EVENT(DBF_WARNING, device,
3094                       " dasd_times_out cqr %p status %x",
3095                       cqr, cqr->status);
3096
3097         spin_lock(&block->queue_lock);
3098         spin_lock(get_ccwdev_lock(device->cdev));
3099         cqr->retries = -1;
3100         cqr->intrc = -ETIMEDOUT;
3101         if (cqr->status >= DASD_CQR_QUEUED) {
3102                 spin_unlock(get_ccwdev_lock(device->cdev));
3103                 rc = dasd_cancel_req(cqr);
3104         } else if (cqr->status == DASD_CQR_FILLED ||
3105                    cqr->status == DASD_CQR_NEED_ERP) {
3106                 cqr->status = DASD_CQR_TERMINATED;
3107                 spin_unlock(get_ccwdev_lock(device->cdev));
3108         } else if (cqr->status == DASD_CQR_IN_ERP) {
3109                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3110
3111                 list_for_each_entry_safe(searchcqr, nextcqr,
3112                                          &block->ccw_queue, blocklist) {
3113                         tmpcqr = searchcqr;
3114                         while (tmpcqr->refers)
3115                                 tmpcqr = tmpcqr->refers;
3116                         if (tmpcqr != cqr)
3117                                 continue;
3118                         /* searchcqr is an ERP request for cqr */
3119                         searchcqr->retries = -1;
3120                         searchcqr->intrc = -ETIMEDOUT;
3121                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3122                                 spin_unlock(get_ccwdev_lock(device->cdev));
3123                                 rc = dasd_cancel_req(searchcqr);
3124                                 spin_lock(get_ccwdev_lock(device->cdev));
3125                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3126                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3127                                 searchcqr->status = DASD_CQR_TERMINATED;
3128                                 rc = 0;
3129                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3130                                 /*
3131                                  * Shouldn't happen; most recent ERP
3132                                  * request is at the front of queue
3133                                  */
3134                                 continue;
3135                         }
3136                         break;
3137                 }
3138                 spin_unlock(get_ccwdev_lock(device->cdev));
3139         }
3140         dasd_schedule_block_bh(block);
3141         spin_unlock(&block->queue_lock);
3142         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3143
3144         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3145 }
3146
3147 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3148                           unsigned int idx)
3149 {
3150         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3151
3152         if (!dq)
3153                 return -ENOMEM;
3154
3155         spin_lock_init(&dq->lock);
3156         hctx->driver_data = dq;
3157
3158         return 0;
3159 }
3160
3161 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3162 {
3163         kfree(hctx->driver_data);
3164         hctx->driver_data = NULL;
3165 }
3166
3167 static void dasd_request_done(struct request *req)
3168 {
3169         blk_mq_end_request(req, 0);
3170         blk_mq_run_hw_queues(req->q, true);
3171 }
3172
3173 static struct blk_mq_ops dasd_mq_ops = {
3174         .queue_rq = do_dasd_request,
3175         .complete = dasd_request_done,
3176         .timeout = dasd_times_out,
3177         .init_hctx = dasd_init_hctx,
3178         .exit_hctx = dasd_exit_hctx,
3179 };
3180
3181 /*
3182  * Allocate and initialize request queue and default I/O scheduler.
3183  */
3184 static int dasd_alloc_queue(struct dasd_block *block)
3185 {
3186         int rc;
3187
3188         block->tag_set.ops = &dasd_mq_ops;
3189         block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
3190         block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
3191         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3192
3193         rc = blk_mq_alloc_tag_set(&block->tag_set);
3194         if (rc)
3195                 return rc;
3196
3197         block->request_queue = blk_mq_init_queue(&block->tag_set);
3198         if (IS_ERR(block->request_queue))
3199                 return PTR_ERR(block->request_queue);
3200
3201         block->request_queue->queuedata = block;
3202
3203         return 0;
3204 }
3205
3206 /*
3207  * Allocate and initialize request queue.
3208  */
3209 static void dasd_setup_queue(struct dasd_block *block)
3210 {
3211         unsigned int logical_block_size = block->bp_block;
3212         struct request_queue *q = block->request_queue;
3213         unsigned int max_bytes, max_discard_sectors;
3214         int max;
3215
3216         if (block->base->features & DASD_FEATURE_USERAW) {
3217                 /*
3218                  * the max_blocks value for raw_track access is 256
3219                  * it is higher than the native ECKD value because we
3220                  * only need one ccw per track
3221                  * so the max_hw_sectors are
3222                  * 2048 x 512B = 1024kB = 16 tracks
3223                  */
3224                 max = 2048;
3225         } else {
3226                 max = block->base->discipline->max_blocks << block->s2b_shift;
3227         }
3228         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
3229         q->limits.max_dev_sectors = max;
3230         blk_queue_logical_block_size(q, logical_block_size);
3231         blk_queue_max_hw_sectors(q, max);
3232         blk_queue_max_segments(q, USHRT_MAX);
3233         /* with page sized segments we can translate each segement into
3234          * one idaw/tidaw
3235          */
3236         blk_queue_max_segment_size(q, PAGE_SIZE);
3237         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
3238
3239         /* Only activate blocklayer discard support for devices that support it */
3240         if (block->base->features & DASD_FEATURE_DISCARD) {
3241                 q->limits.discard_granularity = logical_block_size;
3242                 q->limits.discard_alignment = PAGE_SIZE;
3243
3244                 /* Calculate max_discard_sectors and make it PAGE aligned */
3245                 max_bytes = USHRT_MAX * logical_block_size;
3246                 max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
3247                 max_discard_sectors = max_bytes / logical_block_size;
3248
3249                 blk_queue_max_discard_sectors(q, max_discard_sectors);
3250                 blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
3251                 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
3252         }
3253 }
3254
3255 /*
3256  * Deactivate and free request queue.
3257  */
3258 static void dasd_free_queue(struct dasd_block *block)
3259 {
3260         if (block->request_queue) {
3261                 blk_cleanup_queue(block->request_queue);
3262                 blk_mq_free_tag_set(&block->tag_set);
3263                 block->request_queue = NULL;
3264         }
3265 }
3266
3267 static int dasd_open(struct block_device *bdev, fmode_t mode)
3268 {
3269         struct dasd_device *base;
3270         int rc;
3271
3272         base = dasd_device_from_gendisk(bdev->bd_disk);
3273         if (!base)
3274                 return -ENODEV;
3275
3276         atomic_inc(&base->block->open_count);
3277         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3278                 rc = -ENODEV;
3279                 goto unlock;
3280         }
3281
3282         if (!try_module_get(base->discipline->owner)) {
3283                 rc = -EINVAL;
3284                 goto unlock;
3285         }
3286
3287         if (dasd_probeonly) {
3288                 dev_info(&base->cdev->dev,
3289                          "Accessing the DASD failed because it is in "
3290                          "probeonly mode\n");
3291                 rc = -EPERM;
3292                 goto out;
3293         }
3294
3295         if (base->state <= DASD_STATE_BASIC) {
3296                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3297                               " Cannot open unrecognized device");
3298                 rc = -ENODEV;
3299                 goto out;
3300         }
3301
3302         if ((mode & FMODE_WRITE) &&
3303             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3304              (base->features & DASD_FEATURE_READONLY))) {
3305                 rc = -EROFS;
3306                 goto out;
3307         }
3308
3309         dasd_put_device(base);
3310         return 0;
3311
3312 out:
3313         module_put(base->discipline->owner);
3314 unlock:
3315         atomic_dec(&base->block->open_count);
3316         dasd_put_device(base);
3317         return rc;
3318 }
3319
3320 static void dasd_release(struct gendisk *disk, fmode_t mode)
3321 {
3322         struct dasd_device *base = dasd_device_from_gendisk(disk);
3323         if (base) {
3324                 atomic_dec(&base->block->open_count);
3325                 module_put(base->discipline->owner);
3326                 dasd_put_device(base);
3327         }
3328 }
3329
3330 /*
3331  * Return disk geometry.
3332  */
3333 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3334 {
3335         struct dasd_device *base;
3336
3337         base = dasd_device_from_gendisk(bdev->bd_disk);
3338         if (!base)
3339                 return -ENODEV;
3340
3341         if (!base->discipline ||
3342             !base->discipline->fill_geometry) {
3343                 dasd_put_device(base);
3344                 return -EINVAL;
3345         }
3346         base->discipline->fill_geometry(base->block, geo);
3347         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3348         dasd_put_device(base);
3349         return 0;
3350 }
3351
3352 const struct block_device_operations
3353 dasd_device_operations = {
3354         .owner          = THIS_MODULE,
3355         .open           = dasd_open,
3356         .release        = dasd_release,
3357         .ioctl          = dasd_ioctl,
3358         .compat_ioctl   = dasd_ioctl,
3359         .getgeo         = dasd_getgeo,
3360 };
3361
3362 /*******************************************************************************
3363  * end of block device operations
3364  */
3365
3366 static void
3367 dasd_exit(void)
3368 {
3369 #ifdef CONFIG_PROC_FS
3370         dasd_proc_exit();
3371 #endif
3372         dasd_eer_exit();
3373         if (dasd_page_cache != NULL) {
3374                 kmem_cache_destroy(dasd_page_cache);
3375                 dasd_page_cache = NULL;
3376         }
3377         dasd_gendisk_exit();
3378         dasd_devmap_exit();
3379         if (dasd_debug_area != NULL) {
3380                 debug_unregister(dasd_debug_area);
3381                 dasd_debug_area = NULL;
3382         }
3383         dasd_statistics_removeroot();
3384 }
3385
3386 /*
3387  * SECTION: common functions for ccw_driver use
3388  */
3389
3390 /*
3391  * Is the device read-only?
3392  * Note that this function does not report the setting of the
3393  * readonly device attribute, but how it is configured in z/VM.
3394  */
3395 int dasd_device_is_ro(struct dasd_device *device)
3396 {
3397         struct ccw_dev_id dev_id;
3398         struct diag210 diag_data;
3399         int rc;
3400
3401         if (!MACHINE_IS_VM)
3402                 return 0;
3403         ccw_device_get_id(device->cdev, &dev_id);
3404         memset(&diag_data, 0, sizeof(diag_data));
3405         diag_data.vrdcdvno = dev_id.devno;
3406         diag_data.vrdclen = sizeof(diag_data);
3407         rc = diag210(&diag_data);
3408         if (rc == 0 || rc == 2) {
3409                 return diag_data.vrdcvfla & 0x80;
3410         } else {
3411                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3412                           dev_id.devno, rc);
3413                 return 0;
3414         }
3415 }
3416 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3417
3418 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3419 {
3420         struct ccw_device *cdev = data;
3421         int ret;
3422
3423         ret = ccw_device_set_online(cdev);
3424         if (ret)
3425                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3426                         dev_name(&cdev->dev), ret);
3427 }
3428
3429 /*
3430  * Initial attempt at a probe function. this can be simplified once
3431  * the other detection code is gone.
3432  */
3433 int dasd_generic_probe(struct ccw_device *cdev,
3434                        struct dasd_discipline *discipline)
3435 {
3436         int ret;
3437
3438         ret = dasd_add_sysfs_files(cdev);
3439         if (ret) {
3440                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3441                                 "dasd_generic_probe: could not add "
3442                                 "sysfs entries");
3443                 return ret;
3444         }
3445         cdev->handler = &dasd_int_handler;
3446
3447         /*
3448          * Automatically online either all dasd devices (dasd_autodetect)
3449          * or all devices specified with dasd= parameters during
3450          * initial probe.
3451          */
3452         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3453             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3454                 async_schedule(dasd_generic_auto_online, cdev);
3455         return 0;
3456 }
3457 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3458
3459 void dasd_generic_free_discipline(struct dasd_device *device)
3460 {
3461         /* Forget the discipline information. */
3462         if (device->discipline) {
3463                 if (device->discipline->uncheck_device)
3464                         device->discipline->uncheck_device(device);
3465                 module_put(device->discipline->owner);
3466                 device->discipline = NULL;
3467         }
3468         if (device->base_discipline) {
3469                 module_put(device->base_discipline->owner);
3470                 device->base_discipline = NULL;
3471         }
3472 }
3473 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3474
3475 /*
3476  * This will one day be called from a global not_oper handler.
3477  * It is also used by driver_unregister during module unload.
3478  */
3479 void dasd_generic_remove(struct ccw_device *cdev)
3480 {
3481         struct dasd_device *device;
3482         struct dasd_block *block;
3483
3484         cdev->handler = NULL;
3485
3486         device = dasd_device_from_cdev(cdev);
3487         if (IS_ERR(device)) {
3488                 dasd_remove_sysfs_files(cdev);
3489                 return;
3490         }
3491         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3492             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3493                 /* Already doing offline processing */
3494                 dasd_put_device(device);
3495                 dasd_remove_sysfs_files(cdev);
3496                 return;
3497         }
3498         /*
3499          * This device is removed unconditionally. Set offline
3500          * flag to prevent dasd_open from opening it while it is
3501          * no quite down yet.
3502          */
3503         dasd_set_target_state(device, DASD_STATE_NEW);
3504         /* dasd_delete_device destroys the device reference. */
3505         block = device->block;
3506         dasd_delete_device(device);
3507         /*
3508          * life cycle of block is bound to device, so delete it after
3509          * device was safely removed
3510          */
3511         if (block)
3512                 dasd_free_block(block);
3513
3514         dasd_remove_sysfs_files(cdev);
3515 }
3516 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3517
3518 /*
3519  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3520  * the device is detected for the first time and is supposed to be used
3521  * or the user has started activation through sysfs.
3522  */
3523 int dasd_generic_set_online(struct ccw_device *cdev,
3524                             struct dasd_discipline *base_discipline)
3525 {
3526         struct dasd_discipline *discipline;
3527         struct dasd_device *device;
3528         int rc;
3529
3530         /* first online clears initial online feature flag */
3531         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3532         device = dasd_create_device(cdev);
3533         if (IS_ERR(device))
3534                 return PTR_ERR(device);
3535
3536         discipline = base_discipline;
3537         if (device->features & DASD_FEATURE_USEDIAG) {
3538                 if (!dasd_diag_discipline_pointer) {
3539                         /* Try to load the required module. */
3540                         rc = request_module(DASD_DIAG_MOD);
3541                         if (rc) {
3542                                 pr_warn("%s Setting the DASD online failed "
3543                                         "because the required module %s "
3544                                         "could not be loaded (rc=%d)\n",
3545                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3546                                         rc);
3547                                 dasd_delete_device(device);
3548                                 return -ENODEV;
3549                         }
3550                 }
3551                 /* Module init could have failed, so check again here after
3552                  * request_module(). */
3553                 if (!dasd_diag_discipline_pointer) {
3554                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3555                                 dev_name(&cdev->dev));
3556                         dasd_delete_device(device);
3557                         return -ENODEV;
3558                 }
3559                 discipline = dasd_diag_discipline_pointer;
3560         }
3561         if (!try_module_get(base_discipline->owner)) {
3562                 dasd_delete_device(device);
3563                 return -EINVAL;
3564         }
3565         if (!try_module_get(discipline->owner)) {
3566                 module_put(base_discipline->owner);
3567                 dasd_delete_device(device);
3568                 return -EINVAL;
3569         }
3570         device->base_discipline = base_discipline;
3571         device->discipline = discipline;
3572
3573         /* check_device will allocate block device if necessary */
3574         rc = discipline->check_device(device);
3575         if (rc) {
3576                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3577                         dev_name(&cdev->dev), discipline->name, rc);
3578                 module_put(discipline->owner);
3579                 module_put(base_discipline->owner);
3580                 dasd_delete_device(device);
3581                 return rc;
3582         }
3583
3584         dasd_set_target_state(device, DASD_STATE_ONLINE);
3585         if (device->state <= DASD_STATE_KNOWN) {
3586                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3587                         dev_name(&cdev->dev));
3588                 rc = -ENODEV;
3589                 dasd_set_target_state(device, DASD_STATE_NEW);
3590                 if (device->block)
3591                         dasd_free_block(device->block);
3592                 dasd_delete_device(device);
3593         } else
3594                 pr_debug("dasd_generic device %s found\n",
3595                                 dev_name(&cdev->dev));
3596
3597         wait_event(dasd_init_waitq, _wait_for_device(device));
3598
3599         dasd_put_device(device);
3600         return rc;
3601 }
3602 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3603
3604 int dasd_generic_set_offline(struct ccw_device *cdev)
3605 {
3606         struct dasd_device *device;
3607         struct dasd_block *block;
3608         int max_count, open_count, rc;
3609         unsigned long flags;
3610
3611         rc = 0;
3612         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3613         device = dasd_device_from_cdev_locked(cdev);
3614         if (IS_ERR(device)) {
3615                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3616                 return PTR_ERR(device);
3617         }
3618
3619         /*
3620          * We must make sure that this device is currently not in use.
3621          * The open_count is increased for every opener, that includes
3622          * the blkdev_get in dasd_scan_partitions. We are only interested
3623          * in the other openers.
3624          */
3625         if (device->block) {
3626                 max_count = device->block->bdev ? 0 : -1;
3627                 open_count = atomic_read(&device->block->open_count);
3628                 if (open_count > max_count) {
3629                         if (open_count > 0)
3630                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3631                                         dev_name(&cdev->dev), open_count);
3632                         else
3633                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3634                                         dev_name(&cdev->dev));
3635                         rc = -EBUSY;
3636                         goto out_err;
3637                 }
3638         }
3639
3640         /*
3641          * Test if the offline processing is already running and exit if so.
3642          * If a safe offline is being processed this could only be a normal
3643          * offline that should be able to overtake the safe offline and
3644          * cancel any I/O we do not want to wait for any longer
3645          */
3646         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3647                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3648                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3649                                   &device->flags);
3650                 } else {
3651                         rc = -EBUSY;
3652                         goto out_err;
3653                 }
3654         }
3655         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3656
3657         /*
3658          * if safe_offline is called set safe_offline_running flag and
3659          * clear safe_offline so that a call to normal offline
3660          * can overrun safe_offline processing
3661          */
3662         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3663             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3664                 /* need to unlock here to wait for outstanding I/O */
3665                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3666                 /*
3667                  * If we want to set the device safe offline all IO operations
3668                  * should be finished before continuing the offline process
3669                  * so sync bdev first and then wait for our queues to become
3670                  * empty
3671                  */
3672                 if (device->block) {
3673                         rc = fsync_bdev(device->block->bdev);
3674                         if (rc != 0)
3675                                 goto interrupted;
3676                 }
3677                 dasd_schedule_device_bh(device);
3678                 rc = wait_event_interruptible(shutdown_waitq,
3679                                               _wait_for_empty_queues(device));
3680                 if (rc != 0)
3681                         goto interrupted;
3682
3683                 /*
3684                  * check if a normal offline process overtook the offline
3685                  * processing in this case simply do nothing beside returning
3686                  * that we got interrupted
3687                  * otherwise mark safe offline as not running any longer and
3688                  * continue with normal offline
3689                  */
3690                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3691                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3692                         rc = -ERESTARTSYS;
3693                         goto out_err;
3694                 }
3695                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3696         }
3697         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3698
3699         dasd_set_target_state(device, DASD_STATE_NEW);
3700         /* dasd_delete_device destroys the device reference. */
3701         block = device->block;
3702         dasd_delete_device(device);
3703         /*
3704          * life cycle of block is bound to device, so delete it after
3705          * device was safely removed
3706          */
3707         if (block)
3708                 dasd_free_block(block);
3709
3710         return 0;
3711
3712 interrupted:
3713         /* interrupted by signal */
3714         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3715         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3716         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3717 out_err:
3718         dasd_put_device(device);
3719         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3720         return rc;
3721 }
3722 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3723
3724 int dasd_generic_last_path_gone(struct dasd_device *device)
3725 {
3726         struct dasd_ccw_req *cqr;
3727
3728         dev_warn(&device->cdev->dev, "No operational channel path is left "
3729                  "for the device\n");
3730         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3731         /* First of all call extended error reporting. */
3732         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3733
3734         if (device->state < DASD_STATE_BASIC)
3735                 return 0;
3736         /* Device is active. We want to keep it. */
3737         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3738                 if ((cqr->status == DASD_CQR_IN_IO) ||
3739                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3740                         cqr->status = DASD_CQR_QUEUED;
3741                         cqr->retries++;
3742                 }
3743         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3744         dasd_device_clear_timer(device);
3745         dasd_schedule_device_bh(device);
3746         return 1;
3747 }
3748 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3749
3750 int dasd_generic_path_operational(struct dasd_device *device)
3751 {
3752         dev_info(&device->cdev->dev, "A channel path to the device has become "
3753                  "operational\n");
3754         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3755         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3756         if (device->stopped & DASD_UNRESUMED_PM) {
3757                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3758                 dasd_restore_device(device);
3759                 return 1;
3760         }
3761         dasd_schedule_device_bh(device);
3762         if (device->block) {
3763                 dasd_schedule_block_bh(device->block);
3764                 if (device->block->request_queue)
3765                         blk_mq_run_hw_queues(device->block->request_queue,
3766                                              true);
3767                 }
3768
3769         if (!device->stopped)
3770                 wake_up(&generic_waitq);
3771
3772         return 1;
3773 }
3774 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3775
3776 int dasd_generic_notify(struct ccw_device *cdev, int event)
3777 {
3778         struct dasd_device *device;
3779         int ret;
3780
3781         device = dasd_device_from_cdev_locked(cdev);
3782         if (IS_ERR(device))
3783                 return 0;
3784         ret = 0;
3785         switch (event) {
3786         case CIO_GONE:
3787         case CIO_BOXED:
3788         case CIO_NO_PATH:
3789                 dasd_path_no_path(device);
3790                 ret = dasd_generic_last_path_gone(device);
3791                 break;
3792         case CIO_OPER:
3793                 ret = 1;
3794                 if (dasd_path_get_opm(device))
3795                         ret = dasd_generic_path_operational(device);
3796                 break;
3797         }
3798         dasd_put_device(device);
3799         return ret;
3800 }
3801 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3802
3803 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3804 {
3805         struct dasd_device *device;
3806         int chp, oldopm, hpfpm, ifccpm;
3807
3808         device = dasd_device_from_cdev_locked(cdev);
3809         if (IS_ERR(device))
3810                 return;
3811
3812         oldopm = dasd_path_get_opm(device);
3813         for (chp = 0; chp < 8; chp++) {
3814                 if (path_event[chp] & PE_PATH_GONE) {
3815                         dasd_path_notoper(device, chp);
3816                 }
3817                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3818                         dasd_path_available(device, chp);
3819                         dasd_schedule_device_bh(device);
3820                 }
3821                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3822                         if (!dasd_path_is_operational(device, chp) &&
3823                             !dasd_path_need_verify(device, chp)) {
3824                                 /*
3825                                  * we can not establish a pathgroup on an
3826                                  * unavailable path, so trigger a path
3827                                  * verification first
3828                                  */
3829                         dasd_path_available(device, chp);
3830                         dasd_schedule_device_bh(device);
3831                         }
3832                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3833                                       "Pathgroup re-established\n");
3834                         if (device->discipline->kick_validate)
3835                                 device->discipline->kick_validate(device);
3836                 }
3837         }
3838         hpfpm = dasd_path_get_hpfpm(device);
3839         ifccpm = dasd_path_get_ifccpm(device);
3840         if (!dasd_path_get_opm(device) && hpfpm) {
3841                 /*
3842                  * device has no operational paths but at least one path is
3843                  * disabled due to HPF errors
3844                  * disable HPF at all and use the path(s) again
3845                  */
3846                 if (device->discipline->disable_hpf)
3847                         device->discipline->disable_hpf(device);
3848                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3849                 dasd_path_set_tbvpm(device, hpfpm);
3850                 dasd_schedule_device_bh(device);
3851                 dasd_schedule_requeue(device);
3852         } else if (!dasd_path_get_opm(device) && ifccpm) {
3853                 /*
3854                  * device has no operational paths but at least one path is
3855                  * disabled due to IFCC errors
3856                  * trigger path verification on paths with IFCC errors
3857                  */
3858                 dasd_path_set_tbvpm(device, ifccpm);
3859                 dasd_schedule_device_bh(device);
3860         }
3861         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3862                 dev_warn(&device->cdev->dev,
3863                          "No verified channel paths remain for the device\n");
3864                 DBF_DEV_EVENT(DBF_WARNING, device,
3865                               "%s", "last verified path gone");
3866                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3867                 dasd_device_set_stop_bits(device,
3868                                           DASD_STOPPED_DC_WAIT);
3869         }
3870         dasd_put_device(device);
3871 }
3872 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3873
3874 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3875 {
3876         if (!dasd_path_get_opm(device) && lpm) {
3877                 dasd_path_set_opm(device, lpm);
3878                 dasd_generic_path_operational(device);
3879         } else
3880                 dasd_path_add_opm(device, lpm);
3881         return 0;
3882 }
3883 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3884
3885 /*
3886  * clear active requests and requeue them to block layer if possible
3887  */
3888 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3889 {
3890         struct list_head requeue_queue;
3891         struct dasd_ccw_req *cqr, *n;
3892         struct dasd_ccw_req *refers;
3893         int rc;
3894
3895         INIT_LIST_HEAD(&requeue_queue);
3896         spin_lock_irq(get_ccwdev_lock(device->cdev));
3897         rc = 0;
3898         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3899                 /* Check status and move request to flush_queue */
3900                 if (cqr->status == DASD_CQR_IN_IO) {
3901                         rc = device->discipline->term_IO(cqr);
3902                         if (rc) {
3903                                 /* unable to terminate requeust */
3904                                 dev_err(&device->cdev->dev,
3905                                         "Unable to terminate request %p "
3906                                         "on suspend\n", cqr);
3907                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3908                                 dasd_put_device(device);
3909                                 return rc;
3910                         }
3911                 }
3912                 list_move_tail(&cqr->devlist, &requeue_queue);
3913         }
3914         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3915
3916         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3917                 wait_event(dasd_flush_wq,
3918                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3919
3920                 /* mark sleepon requests as ended */
3921                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
3922                         cqr->callback_data = DASD_SLEEPON_END_TAG;
3923
3924                 /* remove requests from device and block queue */
3925                 list_del_init(&cqr->devlist);
3926                 while (cqr->refers != NULL) {
3927                         refers = cqr->refers;
3928                         /* remove the request from the block queue */
3929                         list_del(&cqr->blocklist);
3930                         /* free the finished erp request */
3931                         dasd_free_erp_request(cqr, cqr->memdev);
3932                         cqr = refers;
3933                 }
3934
3935                 /*
3936                  * requeue requests to blocklayer will only work
3937                  * for block device requests
3938                  */
3939                 if (_dasd_requeue_request(cqr))
3940                         continue;
3941
3942                 if (cqr->block)
3943                         list_del_init(&cqr->blocklist);
3944                 cqr->block->base->discipline->free_cp(
3945                         cqr, (struct request *) cqr->callback_data);
3946         }
3947
3948         /*
3949          * if requests remain then they are internal request
3950          * and go back to the device queue
3951          */
3952         if (!list_empty(&requeue_queue)) {
3953                 /* move freeze_queue to start of the ccw_queue */
3954                 spin_lock_irq(get_ccwdev_lock(device->cdev));
3955                 list_splice_tail(&requeue_queue, &device->ccw_queue);
3956                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3957         }
3958         /* wake up generic waitqueue for eventually ended sleepon requests */
3959         wake_up(&generic_waitq);
3960         return rc;
3961 }
3962
3963 static void do_requeue_requests(struct work_struct *work)
3964 {
3965         struct dasd_device *device = container_of(work, struct dasd_device,
3966                                                   requeue_requests);
3967         dasd_generic_requeue_all_requests(device);
3968         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3969         if (device->block)
3970                 dasd_schedule_block_bh(device->block);
3971         dasd_put_device(device);
3972 }
3973
3974 void dasd_schedule_requeue(struct dasd_device *device)
3975 {
3976         dasd_get_device(device);
3977         /* queue call to dasd_reload_device to the kernel event daemon. */
3978         if (!schedule_work(&device->requeue_requests))
3979                 dasd_put_device(device);
3980 }
3981 EXPORT_SYMBOL(dasd_schedule_requeue);
3982
3983 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3984 {
3985         struct dasd_device *device = dasd_device_from_cdev(cdev);
3986
3987         if (IS_ERR(device))
3988                 return PTR_ERR(device);
3989
3990         /* mark device as suspended */
3991         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3992
3993         if (device->discipline->freeze)
3994                 device->discipline->freeze(device);
3995
3996         /* disallow new I/O  */
3997         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3998
3999         return dasd_generic_requeue_all_requests(device);
4000 }
4001 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
4002
4003 int dasd_generic_restore_device(struct ccw_device *cdev)
4004 {
4005         struct dasd_device *device = dasd_device_from_cdev(cdev);
4006         int rc = 0;
4007
4008         if (IS_ERR(device))
4009                 return PTR_ERR(device);
4010
4011         /* allow new IO again */
4012         dasd_device_remove_stop_bits(device,
4013                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4014
4015         dasd_schedule_device_bh(device);
4016
4017         /*
4018          * call discipline restore function
4019          * if device is stopped do nothing e.g. for disconnected devices
4020          */
4021         if (device->discipline->restore && !(device->stopped))
4022                 rc = device->discipline->restore(device);
4023         if (rc || device->stopped)
4024                 /*
4025                  * if the resume failed for the DASD we put it in
4026                  * an UNRESUMED stop state
4027                  */
4028                 device->stopped |= DASD_UNRESUMED_PM;
4029
4030         if (device->block) {
4031                 dasd_schedule_block_bh(device->block);
4032                 if (device->block->request_queue)
4033                         blk_mq_run_hw_queues(device->block->request_queue,
4034                                              true);
4035         }
4036
4037         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4038         dasd_put_device(device);
4039         return 0;
4040 }
4041 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4042
4043 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4044                                                    void *rdc_buffer,
4045                                                    int rdc_buffer_size,
4046                                                    int magic)
4047 {
4048         struct dasd_ccw_req *cqr;
4049         struct ccw1 *ccw;
4050         unsigned long *idaw;
4051
4052         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
4053
4054         if (IS_ERR(cqr)) {
4055                 /* internal error 13 - Allocating the RDC request failed*/
4056                 dev_err(&device->cdev->dev,
4057                          "An error occurred in the DASD device driver, "
4058                          "reason=%s\n", "13");
4059                 return cqr;
4060         }
4061
4062         ccw = cqr->cpaddr;
4063         ccw->cmd_code = CCW_CMD_RDC;
4064         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
4065                 idaw = (unsigned long *) (cqr->data);
4066                 ccw->cda = (__u32)(addr_t) idaw;
4067                 ccw->flags = CCW_FLAG_IDA;
4068                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
4069         } else {
4070                 ccw->cda = (__u32)(addr_t) rdc_buffer;
4071                 ccw->flags = 0;
4072         }
4073
4074         ccw->count = rdc_buffer_size;
4075         cqr->startdev = device;
4076         cqr->memdev = device;
4077         cqr->expires = 10*HZ;
4078         cqr->retries = 256;
4079         cqr->buildclk = get_tod_clock();
4080         cqr->status = DASD_CQR_FILLED;
4081         return cqr;
4082 }
4083
4084
4085 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4086                                 void *rdc_buffer, int rdc_buffer_size)
4087 {
4088         int ret;
4089         struct dasd_ccw_req *cqr;
4090
4091         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
4092                                      magic);
4093         if (IS_ERR(cqr))
4094                 return PTR_ERR(cqr);
4095
4096         ret = dasd_sleep_on(cqr);
4097         dasd_sfree_request(cqr, cqr->memdev);
4098         return ret;
4099 }
4100 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4101
4102 /*
4103  *   In command mode and transport mode we need to look for sense
4104  *   data in different places. The sense data itself is allways
4105  *   an array of 32 bytes, so we can unify the sense data access
4106  *   for both modes.
4107  */
4108 char *dasd_get_sense(struct irb *irb)
4109 {
4110         struct tsb *tsb = NULL;
4111         char *sense = NULL;
4112
4113         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4114                 if (irb->scsw.tm.tcw)
4115                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4116                                           irb->scsw.tm.tcw);
4117                 if (tsb && tsb->length == 64 && tsb->flags)
4118                         switch (tsb->flags & 0x07) {
4119                         case 1: /* tsa_iostat */
4120                                 sense = tsb->tsa.iostat.sense;
4121                                 break;
4122                         case 2: /* tsa_ddpc */
4123                                 sense = tsb->tsa.ddpc.sense;
4124                                 break;
4125                         default:
4126                                 /* currently we don't use interrogate data */
4127                                 break;
4128                         }
4129         } else if (irb->esw.esw0.erw.cons) {
4130                 sense = irb->ecw;
4131         }
4132         return sense;
4133 }
4134 EXPORT_SYMBOL_GPL(dasd_get_sense);
4135
4136 void dasd_generic_shutdown(struct ccw_device *cdev)
4137 {
4138         struct dasd_device *device;
4139
4140         device = dasd_device_from_cdev(cdev);
4141         if (IS_ERR(device))
4142                 return;
4143
4144         if (device->block)
4145                 dasd_schedule_block_bh(device->block);
4146
4147         dasd_schedule_device_bh(device);
4148
4149         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4150 }
4151 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4152
4153 static int __init dasd_init(void)
4154 {
4155         int rc;
4156
4157         init_waitqueue_head(&dasd_init_waitq);
4158         init_waitqueue_head(&dasd_flush_wq);
4159         init_waitqueue_head(&generic_waitq);
4160         init_waitqueue_head(&shutdown_waitq);
4161
4162         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4163         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4164         if (dasd_debug_area == NULL) {
4165                 rc = -ENOMEM;
4166                 goto failed;
4167         }
4168         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4169         debug_set_level(dasd_debug_area, DBF_WARNING);
4170
4171         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4172
4173         dasd_diag_discipline_pointer = NULL;
4174
4175         dasd_statistics_createroot();
4176
4177         rc = dasd_devmap_init();
4178         if (rc)
4179                 goto failed;
4180         rc = dasd_gendisk_init();
4181         if (rc)
4182                 goto failed;
4183         rc = dasd_parse();
4184         if (rc)
4185                 goto failed;
4186         rc = dasd_eer_init();
4187         if (rc)
4188                 goto failed;
4189 #ifdef CONFIG_PROC_FS
4190         rc = dasd_proc_init();
4191         if (rc)
4192                 goto failed;
4193 #endif
4194
4195         return 0;
4196 failed:
4197         pr_info("The DASD device driver could not be initialized\n");
4198         dasd_exit();
4199         return rc;
4200 }
4201
4202 module_init(dasd_init);
4203 module_exit(dasd_exit);