drivers/s390/block/dasd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_DIAG_MOD           "dasd_diag_mod"
  43
  44 static unsigned int queue_depth = 32;
  45 static unsigned int nr_hw_queues = 4;
  46
  47 module_param(queue_depth, uint, 0444);
  48 MODULE_PARM_DESC(queue_depth, "Default queue depth for new DASD devices");
  49
  50 module_param(nr_hw_queues, uint, 0444);
  51 MODULE_PARM_DESC(nr_hw_queues, "Default number of hardware queues for new DASD devices");
  52
  53 /*
  54  * SECTION: exported variables of dasd.c
  55  */
  56 debug_info_t *dasd_debug_area;
  57 EXPORT_SYMBOL(dasd_debug_area);
  58 static struct dentry *dasd_debugfs_root_entry;
  59 struct dasd_discipline *dasd_diag_discipline_pointer;
  60 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  61 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  62
  63 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  64 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  65                    " Copyright IBM Corp. 2000");
  66 MODULE_SUPPORTED_DEVICE("dasd");
  67 MODULE_LICENSE("GPL");
  68
  69 /*
  70  * SECTION: prototypes for static functions of dasd.c
  71  */
  72 static int  dasd_alloc_queue(struct dasd_block *);
  73 static void dasd_setup_queue(struct dasd_block *);
  74 static void dasd_free_queue(struct dasd_block *);
  75 static int dasd_flush_block_queue(struct dasd_block *);
  76 static void dasd_device_tasklet(unsigned long);
  77 static void dasd_block_tasklet(unsigned long);
  78 static void do_kick_device(struct work_struct *);
  79 static void do_restore_device(struct work_struct *);
  80 static void do_reload_device(struct work_struct *);
  81 static void do_requeue_requests(struct work_struct *);
  82 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  83 static void dasd_device_timeout(struct timer_list *);
  84 static void dasd_block_timeout(struct timer_list *);
  85 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  86 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  87 static void dasd_profile_exit(struct dasd_profile *);
  88 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  89 static void dasd_hosts_exit(struct dasd_device *);
  90
  91 /*
  92  * SECTION: Operations on the device structure.
  93  */
  94 static wait_queue_head_t dasd_init_waitq;
  95 static wait_queue_head_t dasd_flush_wq;
  96 static wait_queue_head_t generic_waitq;
  97 static wait_queue_head_t shutdown_waitq;
  98
  99 /*
 100  * Allocate memory for a new device structure.
 101  */
 102 struct dasd_device *dasd_alloc_device(void)
 103 {
 104         struct dasd_device *device;
 105
 106         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
 107         if (!device)
 108                 return ERR_PTR(-ENOMEM);
 109
 110         /* Get two pages for normal block device operations. */
 111         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 112         if (!device->ccw_mem) {
 113                 kfree(device);
 114                 return ERR_PTR(-ENOMEM);
 115         }
 116         /* Get one page for error recovery. */
 117         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 118         if (!device->erp_mem) {
 119                 free_pages((unsigned long) device->ccw_mem, 1);
 120                 kfree(device);
 121                 return ERR_PTR(-ENOMEM);
 122         }
 123
 124         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 125         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 126         spin_lock_init(&device->mem_lock);
 127         atomic_set(&device->tasklet_scheduled, 0);
 128         tasklet_init(&device->tasklet, dasd_device_tasklet,
 129                      (unsigned long) device);
 130         INIT_LIST_HEAD(&device->ccw_queue);
 131         timer_setup(&device->timer, dasd_device_timeout, 0);
 132         INIT_WORK(&device->kick_work, do_kick_device);
 133         INIT_WORK(&device->restore_device, do_restore_device);
 134         INIT_WORK(&device->reload_device, do_reload_device);
 135         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 136         device->state = DASD_STATE_NEW;
 137         device->target = DASD_STATE_NEW;
 138         mutex_init(&device->state_mutex);
 139         spin_lock_init(&device->profile.lock);
 140         return device;
 141 }
 142
 143 /*
 144  * Free memory of a device structure.
 145  */
 146 void dasd_free_device(struct dasd_device *device)
 147 {
 148         kfree(device->private);
 149         free_page((unsigned long) device->erp_mem);
 150         free_pages((unsigned long) device->ccw_mem, 1);
 151         kfree(device);
 152 }
 153
 154 /*
 155  * Allocate memory for a new device structure.
 156  */
 157 struct dasd_block *dasd_alloc_block(void)
 158 {
 159         struct dasd_block *block;
 160
 161         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 162         if (!block)
 163                 return ERR_PTR(-ENOMEM);
 164         /* open_count = 0 means device online but not in use */
 165         atomic_set(&block->open_count, -1);
 166
 167         atomic_set(&block->tasklet_scheduled, 0);
 168         tasklet_init(&block->tasklet, dasd_block_tasklet,
 169                      (unsigned long) block);
 170         INIT_LIST_HEAD(&block->ccw_queue);
 171         spin_lock_init(&block->queue_lock);
 172         timer_setup(&block->timer, dasd_block_timeout, 0);
 173         spin_lock_init(&block->profile.lock);
 174
 175         return block;
 176 }
 177 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 178
 179 /*
 180  * Free memory of a device structure.
 181  */
 182 void dasd_free_block(struct dasd_block *block)
 183 {
 184         kfree(block);
 185 }
 186 EXPORT_SYMBOL_GPL(dasd_free_block);
 187
 188 /*
 189  * Make a new device known to the system.
 190  */
 191 static int dasd_state_new_to_known(struct dasd_device *device)
 192 {
 193         int rc;
 194
 195         /*
 196          * As long as the device is not in state DASD_STATE_NEW we want to
 197          * keep the reference count > 0.
 198          */
 199         dasd_get_device(device);
 200
 201         if (device->block) {
 202                 rc = dasd_alloc_queue(device->block);
 203                 if (rc) {
 204                         dasd_put_device(device);
 205                         return rc;
 206                 }
 207         }
 208         device->state = DASD_STATE_KNOWN;
 209         return 0;
 210 }
 211
 212 /*
 213  * Let the system forget about a device.
 214  */
 215 static int dasd_state_known_to_new(struct dasd_device *device)
 216 {
 217         /* Disable extended error reporting for this device. */
 218         dasd_eer_disable(device);
 219         device->state = DASD_STATE_NEW;
 220
 221         if (device->block)
 222                 dasd_free_queue(device->block);
 223
 224         /* Give up reference we took in dasd_state_new_to_known. */
 225         dasd_put_device(device);
 226         return 0;
 227 }
 228
 229 static struct dentry *dasd_debugfs_setup(const char *name,
 230                                          struct dentry *base_dentry)
 231 {
 232         struct dentry *pde;
 233
 234         if (!base_dentry)
 235                 return NULL;
 236         pde = debugfs_create_dir(name, base_dentry);
 237         if (!pde || IS_ERR(pde))
 238                 return NULL;
 239         return pde;
 240 }
 241
 242 /*
 243  * Request the irq line for the device.
 244  */
 245 static int dasd_state_known_to_basic(struct dasd_device *device)
 246 {
 247         struct dasd_block *block = device->block;
 248         int rc = 0;
 249
 250         /* Allocate and register gendisk structure. */
 251         if (block) {
 252                 rc = dasd_gendisk_alloc(block);
 253                 if (rc)
 254                         return rc;
 255                 block->debugfs_dentry =
 256                         dasd_debugfs_setup(block->gdp->disk_name,
 257                                            dasd_debugfs_root_entry);
 258                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 259                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 260                         dasd_profile_on(&device->block->profile);
 261         }
 262         device->debugfs_dentry =
 263                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 264                                    dasd_debugfs_root_entry);
 265         dasd_profile_init(&device->profile, device->debugfs_dentry);
 266         dasd_hosts_init(device->debugfs_dentry, device);
 267
 268         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 269         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 270                                             8 * sizeof(long));
 271         debug_register_view(device->debug_area, &debug_sprintf_view);
 272         debug_set_level(device->debug_area, DBF_WARNING);
 273         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 274
 275         device->state = DASD_STATE_BASIC;
 276
 277         return rc;
 278 }
 279
 280 /*
 281  * Release the irq line for the device. Terminate any running i/o.
 282  */
 283 static int dasd_state_basic_to_known(struct dasd_device *device)
 284 {
 285         int rc;
 286
 287         if (device->discipline->basic_to_known) {
 288                 rc = device->discipline->basic_to_known(device);
 289                 if (rc)
 290                         return rc;
 291         }
 292
 293         if (device->block) {
 294                 dasd_profile_exit(&device->block->profile);
 295                 debugfs_remove(device->block->debugfs_dentry);
 296                 dasd_gendisk_free(device->block);
 297                 dasd_block_clear_timer(device->block);
 298         }
 299         rc = dasd_flush_device_queue(device);
 300         if (rc)
 301                 return rc;
 302         dasd_device_clear_timer(device);
 303         dasd_profile_exit(&device->profile);
 304         dasd_hosts_exit(device);
 305         debugfs_remove(device->debugfs_dentry);
 306         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 307         if (device->debug_area != NULL) {
 308                 debug_unregister(device->debug_area);
 309                 device->debug_area = NULL;
 310         }
 311         device->state = DASD_STATE_KNOWN;
 312         return 0;
 313 }
 314
 315 /*
 316  * Do the initial analysis. The do_analysis function may return
 317  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 318  * until the discipline decides to continue the startup sequence
 319  * by calling the function dasd_change_state. The eckd disciplines
 320  * uses this to start a ccw that detects the format. The completion
 321  * interrupt for this detection ccw uses the kernel event daemon to
 322  * trigger the call to dasd_change_state. All this is done in the
 323  * discipline code, see dasd_eckd.c.
 324  * After the analysis ccw is done (do_analysis returned 0) the block
 325  * device is setup.
 326  * In case the analysis returns an error, the device setup is stopped
 327  * (a fake disk was already added to allow formatting).
 328  */
 329 static int dasd_state_basic_to_ready(struct dasd_device *device)
 330 {
 331         int rc;
 332         struct dasd_block *block;
 333         struct gendisk *disk;
 334
 335         rc = 0;
 336         block = device->block;
 337         /* make disk known with correct capacity */
 338         if (block) {
 339                 if (block->base->discipline->do_analysis != NULL)
 340                         rc = block->base->discipline->do_analysis(block);
 341                 if (rc) {
 342                         if (rc != -EAGAIN) {
 343                                 device->state = DASD_STATE_UNFMT;
 344                                 disk = device->block->gdp;
 345                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 346                                                KOBJ_CHANGE);
 347                                 goto out;
 348                         }
 349                         return rc;
 350                 }
 351                 dasd_setup_queue(block);
 352                 set_capacity(block->gdp,
 353                              block->blocks << block->s2b_shift);
 354                 device->state = DASD_STATE_READY;
 355                 rc = dasd_scan_partitions(block);
 356                 if (rc) {
 357                         device->state = DASD_STATE_BASIC;
 358                         return rc;
 359                 }
 360         } else {
 361                 device->state = DASD_STATE_READY;
 362         }
 363 out:
 364         if (device->discipline->basic_to_ready)
 365                 rc = device->discipline->basic_to_ready(device);
 366         return rc;
 367 }
 368
 369 static inline
 370 int _wait_for_empty_queues(struct dasd_device *device)
 371 {
 372         if (device->block)
 373                 return list_empty(&device->ccw_queue) &&
 374                         list_empty(&device->block->ccw_queue);
 375         else
 376                 return list_empty(&device->ccw_queue);
 377 }
 378
 379 /*
 380  * Remove device from block device layer. Destroy dirty buffers.
 381  * Forget format information. Check if the target level is basic
 382  * and if it is create fake disk for formatting.
 383  */
 384 static int dasd_state_ready_to_basic(struct dasd_device *device)
 385 {
 386         int rc;
 387
 388         device->state = DASD_STATE_BASIC;
 389         if (device->block) {
 390                 struct dasd_block *block = device->block;
 391                 rc = dasd_flush_block_queue(block);
 392                 if (rc) {
 393                         device->state = DASD_STATE_READY;
 394                         return rc;
 395                 }
 396                 dasd_destroy_partitions(block);
 397                 block->blocks = 0;
 398                 block->bp_block = 0;
 399                 block->s2b_shift = 0;
 400         }
 401         return 0;
 402 }
 403
 404 /*
 405  * Back to basic.
 406  */
 407 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 408 {
 409         device->state = DASD_STATE_BASIC;
 410         return 0;
 411 }
 412
 413 /*
 414  * Make the device online and schedule the bottom half to start
 415  * the requeueing of requests from the linux request queue to the
 416  * ccw queue.
 417  */
 418 static int
 419 dasd_state_ready_to_online(struct dasd_device * device)
 420 {
 421         struct gendisk *disk;
 422         struct disk_part_iter piter;
 423         struct hd_struct *part;
 424
 425         device->state = DASD_STATE_ONLINE;
 426         if (device->block) {
 427                 dasd_schedule_block_bh(device->block);
 428                 if ((device->features & DASD_FEATURE_USERAW)) {
 429                         disk = device->block->gdp;
 430                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 431                         return 0;
 432                 }
 433                 disk = device->block->bdev->bd_disk;
 434                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 435                 while ((part = disk_part_iter_next(&piter)))
 436                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 437                 disk_part_iter_exit(&piter);
 438         }
 439         return 0;
 440 }
 441
 442 /*
 443  * Stop the requeueing of requests again.
 444  */
 445 static int dasd_state_online_to_ready(struct dasd_device *device)
 446 {
 447         int rc;
 448         struct gendisk *disk;
 449         struct disk_part_iter piter;
 450         struct hd_struct *part;
 451
 452         if (device->discipline->online_to_ready) {
 453                 rc = device->discipline->online_to_ready(device);
 454                 if (rc)
 455                         return rc;
 456         }
 457
 458         device->state = DASD_STATE_READY;
 459         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 460                 disk = device->block->bdev->bd_disk;
 461                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 462                 while ((part = disk_part_iter_next(&piter)))
 463                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 464                 disk_part_iter_exit(&piter);
 465         }
 466         return 0;
 467 }
 468
 469 /*
 470  * Device startup state changes.
 471  */
 472 static int dasd_increase_state(struct dasd_device *device)
 473 {
 474         int rc;
 475
 476         rc = 0;
 477         if (device->state == DASD_STATE_NEW &&
 478             device->target >= DASD_STATE_KNOWN)
 479                 rc = dasd_state_new_to_known(device);
 480
 481         if (!rc &&
 482             device->state == DASD_STATE_KNOWN &&
 483             device->target >= DASD_STATE_BASIC)
 484                 rc = dasd_state_known_to_basic(device);
 485
 486         if (!rc &&
 487             device->state == DASD_STATE_BASIC &&
 488             device->target >= DASD_STATE_READY)
 489                 rc = dasd_state_basic_to_ready(device);
 490
 491         if (!rc &&
 492             device->state == DASD_STATE_UNFMT &&
 493             device->target > DASD_STATE_UNFMT)
 494                 rc = -EPERM;
 495
 496         if (!rc &&
 497             device->state == DASD_STATE_READY &&
 498             device->target >= DASD_STATE_ONLINE)
 499                 rc = dasd_state_ready_to_online(device);
 500
 501         return rc;
 502 }
 503
 504 /*
 505  * Device shutdown state changes.
 506  */
 507 static int dasd_decrease_state(struct dasd_device *device)
 508 {
 509         int rc;
 510
 511         rc = 0;
 512         if (device->state == DASD_STATE_ONLINE &&
 513             device->target <= DASD_STATE_READY)
 514                 rc = dasd_state_online_to_ready(device);
 515
 516         if (!rc &&
 517             device->state == DASD_STATE_READY &&
 518             device->target <= DASD_STATE_BASIC)
 519                 rc = dasd_state_ready_to_basic(device);
 520
 521         if (!rc &&
 522             device->state == DASD_STATE_UNFMT &&
 523             device->target <= DASD_STATE_BASIC)
 524                 rc = dasd_state_unfmt_to_basic(device);
 525
 526         if (!rc &&
 527             device->state == DASD_STATE_BASIC &&
 528             device->target <= DASD_STATE_KNOWN)
 529                 rc = dasd_state_basic_to_known(device);
 530
 531         if (!rc &&
 532             device->state == DASD_STATE_KNOWN &&
 533             device->target <= DASD_STATE_NEW)
 534                 rc = dasd_state_known_to_new(device);
 535
 536         return rc;
 537 }
 538
 539 /*
 540  * This is the main startup/shutdown routine.
 541  */
 542 static void dasd_change_state(struct dasd_device *device)
 543 {
 544         int rc;
 545
 546         if (device->state == device->target)
 547                 /* Already where we want to go today... */
 548                 return;
 549         if (device->state < device->target)
 550                 rc = dasd_increase_state(device);
 551         else
 552                 rc = dasd_decrease_state(device);
 553         if (rc == -EAGAIN)
 554                 return;
 555         if (rc)
 556                 device->target = device->state;
 557
 558         /* let user-space know that the device status changed */
 559         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 560
 561         if (device->state == device->target)
 562                 wake_up(&dasd_init_waitq);
 563 }
 564
 565 /*
 566  * Kick starter for devices that did not complete the startup/shutdown
 567  * procedure or were sleeping because of a pending state.
 568  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 569  * event daemon.
 570  */
 571 static void do_kick_device(struct work_struct *work)
 572 {
 573         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 574         mutex_lock(&device->state_mutex);
 575         dasd_change_state(device);
 576         mutex_unlock(&device->state_mutex);
 577         dasd_schedule_device_bh(device);
 578         dasd_put_device(device);
 579 }
 580
 581 void dasd_kick_device(struct dasd_device *device)
 582 {
 583         dasd_get_device(device);
 584         /* queue call to dasd_kick_device to the kernel event daemon. */
 585         if (!schedule_work(&device->kick_work))
 586                 dasd_put_device(device);
 587 }
 588 EXPORT_SYMBOL(dasd_kick_device);
 589
 590 /*
 591  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 592  * event daemon.
 593  */
 594 static void do_reload_device(struct work_struct *work)
 595 {
 596         struct dasd_device *device = container_of(work, struct dasd_device,
 597                                                   reload_device);
 598         device->discipline->reload(device);
 599         dasd_put_device(device);
 600 }
 601
 602 void dasd_reload_device(struct dasd_device *device)
 603 {
 604         dasd_get_device(device);
 605         /* queue call to dasd_reload_device to the kernel event daemon. */
 606         if (!schedule_work(&device->reload_device))
 607                 dasd_put_device(device);
 608 }
 609 EXPORT_SYMBOL(dasd_reload_device);
 610
 611 /*
 612  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 613  * event daemon.
 614  */
 615 static void do_restore_device(struct work_struct *work)
 616 {
 617         struct dasd_device *device = container_of(work, struct dasd_device,
 618                                                   restore_device);
 619         device->cdev->drv->restore(device->cdev);
 620         dasd_put_device(device);
 621 }
 622
 623 void dasd_restore_device(struct dasd_device *device)
 624 {
 625         dasd_get_device(device);
 626         /* queue call to dasd_restore_device to the kernel event daemon. */
 627         if (!schedule_work(&device->restore_device))
 628                 dasd_put_device(device);
 629 }
 630
 631 /*
 632  * Set the target state for a device and starts the state change.
 633  */
 634 void dasd_set_target_state(struct dasd_device *device, int target)
 635 {
 636         dasd_get_device(device);
 637         mutex_lock(&device->state_mutex);
 638         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 639         if (dasd_probeonly && target > DASD_STATE_READY)
 640                 target = DASD_STATE_READY;
 641         if (device->target != target) {
 642                 if (device->state == target)
 643                         wake_up(&dasd_init_waitq);
 644                 device->target = target;
 645         }
 646         if (device->state != device->target)
 647                 dasd_change_state(device);
 648         mutex_unlock(&device->state_mutex);
 649         dasd_put_device(device);
 650 }
 651 EXPORT_SYMBOL(dasd_set_target_state);
 652
 653 /*
 654  * Enable devices with device numbers in [from..to].
 655  */
 656 static inline int _wait_for_device(struct dasd_device *device)
 657 {
 658         return (device->state == device->target);
 659 }
 660
 661 void dasd_enable_device(struct dasd_device *device)
 662 {
 663         dasd_set_target_state(device, DASD_STATE_ONLINE);
 664         if (device->state <= DASD_STATE_KNOWN)
 665                 /* No discipline for device found. */
 666                 dasd_set_target_state(device, DASD_STATE_NEW);
 667         /* Now wait for the devices to come up. */
 668         wait_event(dasd_init_waitq, _wait_for_device(device));
 669
 670         dasd_reload_device(device);
 671         if (device->discipline->kick_validate)
 672                 device->discipline->kick_validate(device);
 673 }
 674 EXPORT_SYMBOL(dasd_enable_device);
 675
 676 /*
 677  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 678  */
 679
 680 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 681
 682 #ifdef CONFIG_DASD_PROFILE
 683 struct dasd_profile dasd_global_profile = {
 684         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 685 };
 686 static struct dentry *dasd_debugfs_global_entry;
 687
 688 /*
 689  * Add profiling information for cqr before execution.
 690  */
 691 static void dasd_profile_start(struct dasd_block *block,
 692                                struct dasd_ccw_req *cqr,
 693                                struct request *req)
 694 {
 695         struct list_head *l;
 696         unsigned int counter;
 697         struct dasd_device *device;
 698
 699         /* count the length of the chanq for statistics */
 700         counter = 0;
 701         if (dasd_global_profile_level || block->profile.data)
 702                 list_for_each(l, &block->ccw_queue)
 703                         if (++counter >= 31)
 704                                 break;
 705
 706         spin_lock(&dasd_global_profile.lock);
 707         if (dasd_global_profile.data) {
 708                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 709                 if (rq_data_dir(req) == READ)
 710                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 711         }
 712         spin_unlock(&dasd_global_profile.lock);
 713
 714         spin_lock(&block->profile.lock);
 715         if (block->profile.data) {
 716                 block->profile.data->dasd_io_nr_req[counter]++;
 717                 if (rq_data_dir(req) == READ)
 718                         block->profile.data->dasd_read_nr_req[counter]++;
 719         }
 720         spin_unlock(&block->profile.lock);
 721
 722         /*
 723          * We count the request for the start device, even though it may run on
 724          * some other device due to error recovery. This way we make sure that
 725          * we count each request only once.
 726          */
 727         device = cqr->startdev;
 728         if (device->profile.data) {
 729                 counter = 1; /* request is not yet queued on the start device */
 730                 list_for_each(l, &device->ccw_queue)
 731                         if (++counter >= 31)
 732                                 break;
 733         }
 734         spin_lock(&device->profile.lock);
 735         if (device->profile.data) {
 736                 device->profile.data->dasd_io_nr_req[counter]++;
 737                 if (rq_data_dir(req) == READ)
 738                         device->profile.data->dasd_read_nr_req[counter]++;
 739         }
 740         spin_unlock(&device->profile.lock);
 741 }
 742
 743 /*
 744  * Add profiling information for cqr after execution.
 745  */
 746
 747 #define dasd_profile_counter(value, index)                         \
 748 {                                                                  \
 749         for (index = 0; index < 31 && value >> (2+index); index++) \
 750                 ;                                                  \
 751 }
 752
 753 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 754                                       int is_alias,
 755                                       int is_tpm,
 756                                       int is_read,
 757                                       long sectors,
 758                                       int sectors_ind,
 759                                       int tottime_ind,
 760                                       int tottimeps_ind,
 761                                       int strtime_ind,
 762                                       int irqtime_ind,
 763                                       int irqtimeps_ind,
 764                                       int endtime_ind)
 765 {
 766         /* in case of an overflow, reset the whole profile */
 767         if (data->dasd_io_reqs == UINT_MAX) {
 768                         memset(data, 0, sizeof(*data));
 769                         ktime_get_real_ts64(&data->starttod);
 770         }
 771         data->dasd_io_reqs++;
 772         data->dasd_io_sects += sectors;
 773         if (is_alias)
 774                 data->dasd_io_alias++;
 775         if (is_tpm)
 776                 data->dasd_io_tpm++;
 777
 778         data->dasd_io_secs[sectors_ind]++;
 779         data->dasd_io_times[tottime_ind]++;
 780         data->dasd_io_timps[tottimeps_ind]++;
 781         data->dasd_io_time1[strtime_ind]++;
 782         data->dasd_io_time2[irqtime_ind]++;
 783         data->dasd_io_time2ps[irqtimeps_ind]++;
 784         data->dasd_io_time3[endtime_ind]++;
 785
 786         if (is_read) {
 787                 data->dasd_read_reqs++;
 788                 data->dasd_read_sects += sectors;
 789                 if (is_alias)
 790                         data->dasd_read_alias++;
 791                 if (is_tpm)
 792                         data->dasd_read_tpm++;
 793                 data->dasd_read_secs[sectors_ind]++;
 794                 data->dasd_read_times[tottime_ind]++;
 795                 data->dasd_read_time1[strtime_ind]++;
 796                 data->dasd_read_time2[irqtime_ind]++;
 797                 data->dasd_read_time3[endtime_ind]++;
 798         }
 799 }
 800
 801 static void dasd_profile_end(struct dasd_block *block,
 802                              struct dasd_ccw_req *cqr,
 803                              struct request *req)
 804 {
 805         unsigned long strtime, irqtime, endtime, tottime;
 806         unsigned long tottimeps, sectors;
 807         struct dasd_device *device;
 808         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 809         int irqtime_ind, irqtimeps_ind, endtime_ind;
 810         struct dasd_profile_info *data;
 811
 812         device = cqr->startdev;
 813         if (!(dasd_global_profile_level ||
 814               block->profile.data ||
 815               device->profile.data))
 816                 return;
 817
 818         sectors = blk_rq_sectors(req);
 819         if (!cqr->buildclk || !cqr->startclk ||
 820             !cqr->stopclk || !cqr->endclk ||
 821             !sectors)
 822                 return;
 823
 824         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 825         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 826         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 827         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 828         tottimeps = tottime / sectors;
 829
 830         dasd_profile_counter(sectors, sectors_ind);
 831         dasd_profile_counter(tottime, tottime_ind);
 832         dasd_profile_counter(tottimeps, tottimeps_ind);
 833         dasd_profile_counter(strtime, strtime_ind);
 834         dasd_profile_counter(irqtime, irqtime_ind);
 835         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 836         dasd_profile_counter(endtime, endtime_ind);
 837
 838         spin_lock(&dasd_global_profile.lock);
 839         if (dasd_global_profile.data) {
 840                 data = dasd_global_profile.data;
 841                 data->dasd_sum_times += tottime;
 842                 data->dasd_sum_time_str += strtime;
 843                 data->dasd_sum_time_irq += irqtime;
 844                 data->dasd_sum_time_end += endtime;
 845                 dasd_profile_end_add_data(dasd_global_profile.data,
 846                                           cqr->startdev != block->base,
 847                                           cqr->cpmode == 1,
 848                                           rq_data_dir(req) == READ,
 849                                           sectors, sectors_ind, tottime_ind,
 850                                           tottimeps_ind, strtime_ind,
 851                                           irqtime_ind, irqtimeps_ind,
 852                                           endtime_ind);
 853         }
 854         spin_unlock(&dasd_global_profile.lock);
 855
 856         spin_lock(&block->profile.lock);
 857         if (block->profile.data) {
 858                 data = block->profile.data;
 859                 data->dasd_sum_times += tottime;
 860                 data->dasd_sum_time_str += strtime;
 861                 data->dasd_sum_time_irq += irqtime;
 862                 data->dasd_sum_time_end += endtime;
 863                 dasd_profile_end_add_data(block->profile.data,
 864                                           cqr->startdev != block->base,
 865                                           cqr->cpmode == 1,
 866                                           rq_data_dir(req) == READ,
 867                                           sectors, sectors_ind, tottime_ind,
 868                                           tottimeps_ind, strtime_ind,
 869                                           irqtime_ind, irqtimeps_ind,
 870                                           endtime_ind);
 871         }
 872         spin_unlock(&block->profile.lock);
 873
 874         spin_lock(&device->profile.lock);
 875         if (device->profile.data) {
 876                 data = device->profile.data;
 877                 data->dasd_sum_times += tottime;
 878                 data->dasd_sum_time_str += strtime;
 879                 data->dasd_sum_time_irq += irqtime;
 880                 data->dasd_sum_time_end += endtime;
 881                 dasd_profile_end_add_data(device->profile.data,
 882                                           cqr->startdev != block->base,
 883                                           cqr->cpmode == 1,
 884                                           rq_data_dir(req) == READ,
 885                                           sectors, sectors_ind, tottime_ind,
 886                                           tottimeps_ind, strtime_ind,
 887                                           irqtime_ind, irqtimeps_ind,
 888                                           endtime_ind);
 889         }
 890         spin_unlock(&device->profile.lock);
 891 }
 892
 893 void dasd_profile_reset(struct dasd_profile *profile)
 894 {
 895         struct dasd_profile_info *data;
 896
 897         spin_lock_bh(&profile->lock);
 898         data = profile->data;
 899         if (!data) {
 900                 spin_unlock_bh(&profile->lock);
 901                 return;
 902         }
 903         memset(data, 0, sizeof(*data));
 904         ktime_get_real_ts64(&data->starttod);
 905         spin_unlock_bh(&profile->lock);
 906 }
 907
 908 int dasd_profile_on(struct dasd_profile *profile)
 909 {
 910         struct dasd_profile_info *data;
 911
 912         data = kzalloc(sizeof(*data), GFP_KERNEL);
 913         if (!data)
 914                 return -ENOMEM;
 915         spin_lock_bh(&profile->lock);
 916         if (profile->data) {
 917                 spin_unlock_bh(&profile->lock);
 918                 kfree(data);
 919                 return 0;
 920         }
 921         ktime_get_real_ts64(&data->starttod);
 922         profile->data = data;
 923         spin_unlock_bh(&profile->lock);
 924         return 0;
 925 }
 926
 927 void dasd_profile_off(struct dasd_profile *profile)
 928 {
 929         spin_lock_bh(&profile->lock);
 930         kfree(profile->data);
 931         profile->data = NULL;
 932         spin_unlock_bh(&profile->lock);
 933 }
 934
 935 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 936 {
 937         char *buffer;
 938
 939         buffer = vmalloc(user_len + 1);
 940         if (buffer == NULL)
 941                 return ERR_PTR(-ENOMEM);
 942         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 943                 vfree(buffer);
 944                 return ERR_PTR(-EFAULT);
 945         }
 946         /* got the string, now strip linefeed. */
 947         if (buffer[user_len - 1] == '\n')
 948                 buffer[user_len - 1] = 0;
 949         else
 950                 buffer[user_len] = 0;
 951         return buffer;
 952 }
 953
 954 static ssize_t dasd_stats_write(struct file *file,
 955                                 const char __user *user_buf,
 956                                 size_t user_len, loff_t *pos)
 957 {
 958         char *buffer, *str;
 959         int rc;
 960         struct seq_file *m = (struct seq_file *)file->private_data;
 961         struct dasd_profile *prof = m->private;
 962
 963         if (user_len > 65536)
 964                 user_len = 65536;
 965         buffer = dasd_get_user_string(user_buf, user_len);
 966         if (IS_ERR(buffer))
 967                 return PTR_ERR(buffer);
 968
 969         str = skip_spaces(buffer);
 970         rc = user_len;
 971         if (strncmp(str, "reset", 5) == 0) {
 972                 dasd_profile_reset(prof);
 973         } else if (strncmp(str, "on", 2) == 0) {
 974                 rc = dasd_profile_on(prof);
 975                 if (rc)
 976                         goto out;
 977                 rc = user_len;
 978                 if (prof == &dasd_global_profile) {
 979                         dasd_profile_reset(prof);
 980                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 981                 }
 982         } else if (strncmp(str, "off", 3) == 0) {
 983                 if (prof == &dasd_global_profile)
 984                         dasd_global_profile_level = DASD_PROFILE_OFF;
 985                 dasd_profile_off(prof);
 986         } else
 987                 rc = -EINVAL;
 988 out:
 989         vfree(buffer);
 990         return rc;
 991 }
 992
 993 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 994 {
 995         int i;
 996
 997         for (i = 0; i < 32; i++)
 998                 seq_printf(m, "%u ", array[i]);
 999         seq_putc(m, '\n');
1000 }
1001
1002 static void dasd_stats_seq_print(struct seq_file *m,
1003                                  struct dasd_profile_info *data)
1004 {
1005         seq_printf(m, "start_time %lld.%09ld\n",
1006                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1007         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1008         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1009         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1010         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1011         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1012                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1013         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1014                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1015         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1016                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1017         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1018                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1019         seq_puts(m, "histogram_sectors ");
1020         dasd_stats_array(m, data->dasd_io_secs);
1021         seq_puts(m, "histogram_io_times ");
1022         dasd_stats_array(m, data->dasd_io_times);
1023         seq_puts(m, "histogram_io_times_weighted ");
1024         dasd_stats_array(m, data->dasd_io_timps);
1025         seq_puts(m, "histogram_time_build_to_ssch ");
1026         dasd_stats_array(m, data->dasd_io_time1);
1027         seq_puts(m, "histogram_time_ssch_to_irq ");
1028         dasd_stats_array(m, data->dasd_io_time2);
1029         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1030         dasd_stats_array(m, data->dasd_io_time2ps);
1031         seq_puts(m, "histogram_time_irq_to_end ");
1032         dasd_stats_array(m, data->dasd_io_time3);
1033         seq_puts(m, "histogram_ccw_queue_length ");
1034         dasd_stats_array(m, data->dasd_io_nr_req);
1035         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1036         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1037         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1038         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1039         seq_puts(m, "histogram_read_sectors ");
1040         dasd_stats_array(m, data->dasd_read_secs);
1041         seq_puts(m, "histogram_read_times ");
1042         dasd_stats_array(m, data->dasd_read_times);
1043         seq_puts(m, "histogram_read_time_build_to_ssch ");
1044         dasd_stats_array(m, data->dasd_read_time1);
1045         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1046         dasd_stats_array(m, data->dasd_read_time2);
1047         seq_puts(m, "histogram_read_time_irq_to_end ");
1048         dasd_stats_array(m, data->dasd_read_time3);
1049         seq_puts(m, "histogram_read_ccw_queue_length ");
1050         dasd_stats_array(m, data->dasd_read_nr_req);
1051 }
1052
1053 static int dasd_stats_show(struct seq_file *m, void *v)
1054 {
1055         struct dasd_profile *profile;
1056         struct dasd_profile_info *data;
1057
1058         profile = m->private;
1059         spin_lock_bh(&profile->lock);
1060         data = profile->data;
1061         if (!data) {
1062                 spin_unlock_bh(&profile->lock);
1063                 seq_puts(m, "disabled\n");
1064                 return 0;
1065         }
1066         dasd_stats_seq_print(m, data);
1067         spin_unlock_bh(&profile->lock);
1068         return 0;
1069 }
1070
1071 static int dasd_stats_open(struct inode *inode, struct file *file)
1072 {
1073         struct dasd_profile *profile = inode->i_private;
1074         return single_open(file, dasd_stats_show, profile);
1075 }
1076
1077 static const struct file_operations dasd_stats_raw_fops = {
1078         .owner          = THIS_MODULE,
1079         .open           = dasd_stats_open,
1080         .read           = seq_read,
1081         .llseek         = seq_lseek,
1082         .release        = single_release,
1083         .write          = dasd_stats_write,
1084 };
1085
1086 static void dasd_profile_init(struct dasd_profile *profile,
1087                               struct dentry *base_dentry)
1088 {
1089         umode_t mode;
1090         struct dentry *pde;
1091
1092         if (!base_dentry)
1093                 return;
1094         profile->dentry = NULL;
1095         profile->data = NULL;
1096         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1097         pde = debugfs_create_file("statistics", mode, base_dentry,
1098                                   profile, &dasd_stats_raw_fops);
1099         if (pde && !IS_ERR(pde))
1100                 profile->dentry = pde;
1101         return;
1102 }
1103
1104 static void dasd_profile_exit(struct dasd_profile *profile)
1105 {
1106         dasd_profile_off(profile);
1107         debugfs_remove(profile->dentry);
1108         profile->dentry = NULL;
1109 }
1110
1111 static void dasd_statistics_removeroot(void)
1112 {
1113         dasd_global_profile_level = DASD_PROFILE_OFF;
1114         dasd_profile_exit(&dasd_global_profile);
1115         debugfs_remove(dasd_debugfs_global_entry);
1116         debugfs_remove(dasd_debugfs_root_entry);
1117 }
1118
1119 static void dasd_statistics_createroot(void)
1120 {
1121         struct dentry *pde;
1122
1123         dasd_debugfs_root_entry = NULL;
1124         pde = debugfs_create_dir("dasd", NULL);
1125         if (!pde || IS_ERR(pde))
1126                 goto error;
1127         dasd_debugfs_root_entry = pde;
1128         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1129         if (!pde || IS_ERR(pde))
1130                 goto error;
1131         dasd_debugfs_global_entry = pde;
1132         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1133         return;
1134
1135 error:
1136         DBF_EVENT(DBF_ERR, "%s",
1137                   "Creation of the dasd debugfs interface failed");
1138         dasd_statistics_removeroot();
1139         return;
1140 }
1141
1142 #else
1143 #define dasd_profile_start(block, cqr, req) do {} while (0)
1144 #define dasd_profile_end(block, cqr, req) do {} while (0)
1145
1146 static void dasd_statistics_createroot(void)
1147 {
1148         return;
1149 }
1150
1151 static void dasd_statistics_removeroot(void)
1152 {
1153         return;
1154 }
1155
1156 int dasd_stats_generic_show(struct seq_file *m, void *v)
1157 {
1158         seq_puts(m, "Statistics are not activated in this kernel\n");
1159         return 0;
1160 }
1161
1162 static void dasd_profile_init(struct dasd_profile *profile,
1163                               struct dentry *base_dentry)
1164 {
1165         return;
1166 }
1167
1168 static void dasd_profile_exit(struct dasd_profile *profile)
1169 {
1170         return;
1171 }
1172
1173 int dasd_profile_on(struct dasd_profile *profile)
1174 {
1175         return 0;
1176 }
1177
1178 #endif                          /* CONFIG_DASD_PROFILE */
1179
1180 static int dasd_hosts_show(struct seq_file *m, void *v)
1181 {
1182         struct dasd_device *device;
1183         int rc = -EOPNOTSUPP;
1184
1185         device = m->private;
1186         dasd_get_device(device);
1187
1188         if (device->discipline->hosts_print)
1189                 rc = device->discipline->hosts_print(device, m);
1190
1191         dasd_put_device(device);
1192         return rc;
1193 }
1194
1195 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1196
1197 static void dasd_hosts_exit(struct dasd_device *device)
1198 {
1199         debugfs_remove(device->hosts_dentry);
1200         device->hosts_dentry = NULL;
1201 }
1202
1203 static void dasd_hosts_init(struct dentry *base_dentry,
1204                             struct dasd_device *device)
1205 {
1206         struct dentry *pde;
1207         umode_t mode;
1208
1209         if (!base_dentry)
1210                 return;
1211
1212         mode = S_IRUSR | S_IFREG;
1213         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1214                                   device, &dasd_hosts_fops);
1215         if (pde && !IS_ERR(pde))
1216                 device->hosts_dentry = pde;
1217 }
1218
1219 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1220                                           struct dasd_device *device,
1221                                           struct dasd_ccw_req *cqr)
1222 {
1223         unsigned long flags;
1224         char *data, *chunk;
1225         int size = 0;
1226
1227         if (cplength > 0)
1228                 size += cplength * sizeof(struct ccw1);
1229         if (datasize > 0)
1230                 size += datasize;
1231         if (!cqr)
1232                 size += (sizeof(*cqr) + 7L) & -8L;
1233
1234         spin_lock_irqsave(&device->mem_lock, flags);
1235         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1236         spin_unlock_irqrestore(&device->mem_lock, flags);
1237         if (!chunk)
1238                 return ERR_PTR(-ENOMEM);
1239         if (!cqr) {
1240                 cqr = (void *) data;
1241                 data += (sizeof(*cqr) + 7L) & -8L;
1242         }
1243         memset(cqr, 0, sizeof(*cqr));
1244         cqr->mem_chunk = chunk;
1245         if (cplength > 0) {
1246                 cqr->cpaddr = data;
1247                 data += cplength * sizeof(struct ccw1);
1248                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1249         }
1250         if (datasize > 0) {
1251                 cqr->data = data;
1252                 memset(cqr->data, 0, datasize);
1253         }
1254         cqr->magic = magic;
1255         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1256         dasd_get_device(device);
1257         return cqr;
1258 }
1259 EXPORT_SYMBOL(dasd_smalloc_request);
1260
1261 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1262 {
1263         unsigned long flags;
1264
1265         spin_lock_irqsave(&device->mem_lock, flags);
1266         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1267         spin_unlock_irqrestore(&device->mem_lock, flags);
1268         dasd_put_device(device);
1269 }
1270 EXPORT_SYMBOL(dasd_sfree_request);
1271
1272 /*
1273  * Check discipline magic in cqr.
1274  */
1275 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1276 {
1277         struct dasd_device *device;
1278
1279         if (cqr == NULL)
1280                 return -EINVAL;
1281         device = cqr->startdev;
1282         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1283                 DBF_DEV_EVENT(DBF_WARNING, device,
1284                             " dasd_ccw_req 0x%08x magic doesn't match"
1285                             " discipline 0x%08x",
1286                             cqr->magic,
1287                             *(unsigned int *) device->discipline->name);
1288                 return -EINVAL;
1289         }
1290         return 0;
1291 }
1292
1293 /*
1294  * Terminate the current i/o and set the request to clear_pending.
1295  * Timer keeps device runnig.
1296  * ccw_device_clear can fail if the i/o subsystem
1297  * is in a bad mood.
1298  */
1299 int dasd_term_IO(struct dasd_ccw_req *cqr)
1300 {
1301         struct dasd_device *device;
1302         int retries, rc;
1303         char errorstring[ERRORLENGTH];
1304
1305         /* Check the cqr */
1306         rc = dasd_check_cqr(cqr);
1307         if (rc)
1308                 return rc;
1309         retries = 0;
1310         device = (struct dasd_device *) cqr->startdev;
1311         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1312                 rc = ccw_device_clear(device->cdev, (long) cqr);
1313                 switch (rc) {
1314                 case 0: /* termination successful */
1315                         cqr->status = DASD_CQR_CLEAR_PENDING;
1316                         cqr->stopclk = get_tod_clock();
1317                         cqr->starttime = 0;
1318                         DBF_DEV_EVENT(DBF_DEBUG, device,
1319                                       "terminate cqr %p successful",
1320                                       cqr);
1321                         break;
1322                 case -ENODEV:
1323                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1324                                       "device gone, retry");
1325                         break;
1326                 case -EINVAL:
1327                         /*
1328                          * device not valid so no I/O could be running
1329                          * handle CQR as termination successful
1330                          */
1331                         cqr->status = DASD_CQR_CLEARED;
1332                         cqr->stopclk = get_tod_clock();
1333                         cqr->starttime = 0;
1334                         /* no retries for invalid devices */
1335                         cqr->retries = -1;
1336                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1337                                       "EINVAL, handle as terminated");
1338                         /* fake rc to success */
1339                         rc = 0;
1340                         break;
1341                 default:
1342                         /* internal error 10 - unknown rc*/
1343                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1344                         dev_err(&device->cdev->dev, "An error occurred in the "
1345                                 "DASD device driver, reason=%s\n", errorstring);
1346                         BUG();
1347                         break;
1348                 }
1349                 retries++;
1350         }
1351         dasd_schedule_device_bh(device);
1352         return rc;
1353 }
1354 EXPORT_SYMBOL(dasd_term_IO);
1355
1356 /*
1357  * Start the i/o. This start_IO can fail if the channel is really busy.
1358  * In that case set up a timer to start the request later.
1359  */
1360 int dasd_start_IO(struct dasd_ccw_req *cqr)
1361 {
1362         struct dasd_device *device;
1363         int rc;
1364         char errorstring[ERRORLENGTH];
1365
1366         /* Check the cqr */
1367         rc = dasd_check_cqr(cqr);
1368         if (rc) {
1369                 cqr->intrc = rc;
1370                 return rc;
1371         }
1372         device = (struct dasd_device *) cqr->startdev;
1373         if (((cqr->block &&
1374               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1375              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1376             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1377                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1378                               "because of stolen lock", cqr);
1379                 cqr->status = DASD_CQR_ERROR;
1380                 cqr->intrc = -EPERM;
1381                 return -EPERM;
1382         }
1383         if (cqr->retries < 0) {
1384                 /* internal error 14 - start_IO run out of retries */
1385                 sprintf(errorstring, "14 %p", cqr);
1386                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1387                         "device driver, reason=%s\n", errorstring);
1388                 cqr->status = DASD_CQR_ERROR;
1389                 return -EIO;
1390         }
1391         cqr->startclk = get_tod_clock();
1392         cqr->starttime = jiffies;
1393         cqr->retries--;
1394         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1395                 cqr->lpm &= dasd_path_get_opm(device);
1396                 if (!cqr->lpm)
1397                         cqr->lpm = dasd_path_get_opm(device);
1398         }
1399         if (cqr->cpmode == 1) {
1400                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1401                                          (long) cqr, cqr->lpm);
1402         } else {
1403                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1404                                       (long) cqr, cqr->lpm, 0);
1405         }
1406         switch (rc) {
1407         case 0:
1408                 cqr->status = DASD_CQR_IN_IO;
1409                 break;
1410         case -EBUSY:
1411                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1412                               "start_IO: device busy, retry later");
1413                 break;
1414         case -EACCES:
1415                 /* -EACCES indicates that the request used only a subset of the
1416                  * available paths and all these paths are gone. If the lpm of
1417                  * this request was only a subset of the opm (e.g. the ppm) then
1418                  * we just do a retry with all available paths.
1419                  * If we already use the full opm, something is amiss, and we
1420                  * need a full path verification.
1421                  */
1422                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1423                         DBF_DEV_EVENT(DBF_WARNING, device,
1424                                       "start_IO: selected paths gone (%x)",
1425                                       cqr->lpm);
1426                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1427                         cqr->lpm = dasd_path_get_opm(device);
1428                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1429                                       "start_IO: selected paths gone,"
1430                                       " retry on all paths");
1431                 } else {
1432                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1433                                       "start_IO: all paths in opm gone,"
1434                                       " do path verification");
1435                         dasd_generic_last_path_gone(device);
1436                         dasd_path_no_path(device);
1437                         dasd_path_set_tbvpm(device,
1438                                           ccw_device_get_path_mask(
1439                                                   device->cdev));
1440                 }
1441                 break;
1442         case -ENODEV:
1443                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1444                               "start_IO: -ENODEV device gone, retry");
1445                 break;
1446         case -EIO:
1447                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1448                               "start_IO: -EIO device gone, retry");
1449                 break;
1450         case -EINVAL:
1451                 /* most likely caused in power management context */
1452                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1453                               "start_IO: -EINVAL device currently "
1454                               "not accessible");
1455                 break;
1456         default:
1457                 /* internal error 11 - unknown rc */
1458                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1459                 dev_err(&device->cdev->dev,
1460                         "An error occurred in the DASD device driver, "
1461                         "reason=%s\n", errorstring);
1462                 BUG();
1463                 break;
1464         }
1465         cqr->intrc = rc;
1466         return rc;
1467 }
1468 EXPORT_SYMBOL(dasd_start_IO);
1469
1470 /*
1471  * Timeout function for dasd devices. This is used for different purposes
1472  *  1) missing interrupt handler for normal operation
1473  *  2) delayed start of request where start_IO failed with -EBUSY
1474  *  3) timeout for missing state change interrupts
1475  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1476  * DASD_CQR_QUEUED for 2) and 3).
1477  */
1478 static void dasd_device_timeout(struct timer_list *t)
1479 {
1480         unsigned long flags;
1481         struct dasd_device *device;
1482
1483         device = from_timer(device, t, timer);
1484         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1485         /* re-activate request queue */
1486         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1487         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1488         dasd_schedule_device_bh(device);
1489 }
1490
1491 /*
1492  * Setup timeout for a device in jiffies.
1493  */
1494 void dasd_device_set_timer(struct dasd_device *device, int expires)
1495 {
1496         if (expires == 0)
1497                 del_timer(&device->timer);
1498         else
1499                 mod_timer(&device->timer, jiffies + expires);
1500 }
1501 EXPORT_SYMBOL(dasd_device_set_timer);
1502
1503 /*
1504  * Clear timeout for a device.
1505  */
1506 void dasd_device_clear_timer(struct dasd_device *device)
1507 {
1508         del_timer(&device->timer);
1509 }
1510 EXPORT_SYMBOL(dasd_device_clear_timer);
1511
1512 static void dasd_handle_killed_request(struct ccw_device *cdev,
1513                                        unsigned long intparm)
1514 {
1515         struct dasd_ccw_req *cqr;
1516         struct dasd_device *device;
1517
1518         if (!intparm)
1519                 return;
1520         cqr = (struct dasd_ccw_req *) intparm;
1521         if (cqr->status != DASD_CQR_IN_IO) {
1522                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1523                                 "invalid status in handle_killed_request: "
1524                                 "%02x", cqr->status);
1525                 return;
1526         }
1527
1528         device = dasd_device_from_cdev_locked(cdev);
1529         if (IS_ERR(device)) {
1530                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1531                                 "unable to get device from cdev");
1532                 return;
1533         }
1534
1535         if (!cqr->startdev ||
1536             device != cqr->startdev ||
1537             strncmp(cqr->startdev->discipline->ebcname,
1538                     (char *) &cqr->magic, 4)) {
1539                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1540                                 "invalid device in request");
1541                 dasd_put_device(device);
1542                 return;
1543         }
1544
1545         /* Schedule request to be retried. */
1546         cqr->status = DASD_CQR_QUEUED;
1547
1548         dasd_device_clear_timer(device);
1549         dasd_schedule_device_bh(device);
1550         dasd_put_device(device);
1551 }
1552
1553 void dasd_generic_handle_state_change(struct dasd_device *device)
1554 {
1555         /* First of all start sense subsystem status request. */
1556         dasd_eer_snss(device);
1557
1558         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1559         dasd_schedule_device_bh(device);
1560         if (device->block) {
1561                 dasd_schedule_block_bh(device->block);
1562                 if (device->block->request_queue)
1563                         blk_mq_run_hw_queues(device->block->request_queue,
1564                                              true);
1565         }
1566 }
1567 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1568
1569 static int dasd_check_hpf_error(struct irb *irb)
1570 {
1571         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1572             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1573              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1574 }
1575
1576 /*
1577  * Interrupt handler for "normal" ssch-io based dasd devices.
1578  */
1579 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1580                       struct irb *irb)
1581 {
1582         struct dasd_ccw_req *cqr, *next;
1583         struct dasd_device *device;
1584         unsigned long now;
1585         int nrf_suppressed = 0;
1586         int fp_suppressed = 0;
1587         u8 *sense = NULL;
1588         int expires;
1589
1590         cqr = (struct dasd_ccw_req *) intparm;
1591         if (IS_ERR(irb)) {
1592                 switch (PTR_ERR(irb)) {
1593                 case -EIO:
1594                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1595                                 device = cqr->startdev;
1596                                 cqr->status = DASD_CQR_CLEARED;
1597                                 dasd_device_clear_timer(device);
1598                                 wake_up(&dasd_flush_wq);
1599                                 dasd_schedule_device_bh(device);
1600                                 return;
1601                         }
1602                         break;
1603                 case -ETIMEDOUT:
1604                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1605                                         "request timed out\n", __func__);
1606                         break;
1607                 default:
1608                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1609                                         "unknown error %ld\n", __func__,
1610                                         PTR_ERR(irb));
1611                 }
1612                 dasd_handle_killed_request(cdev, intparm);
1613                 return;
1614         }
1615
1616         now = get_tod_clock();
1617         /* check for conditions that should be handled immediately */
1618         if (!cqr ||
1619             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1620               scsw_cstat(&irb->scsw) == 0)) {
1621                 if (cqr)
1622                         memcpy(&cqr->irb, irb, sizeof(*irb));
1623                 device = dasd_device_from_cdev_locked(cdev);
1624                 if (IS_ERR(device))
1625                         return;
1626                 /* ignore unsolicited interrupts for DIAG discipline */
1627                 if (device->discipline == dasd_diag_discipline_pointer) {
1628                         dasd_put_device(device);
1629                         return;
1630                 }
1631
1632                 /*
1633                  * In some cases 'File Protected' or 'No Record Found' errors
1634                  * might be expected and debug log messages for the
1635                  * corresponding interrupts shouldn't be written then.
1636                  * Check if either of the according suppress bits is set.
1637                  */
1638                 sense = dasd_get_sense(irb);
1639                 if (sense) {
1640                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1641                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1642                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1643                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1644                 }
1645                 if (!(fp_suppressed || nrf_suppressed))
1646                         device->discipline->dump_sense_dbf(device, irb, "int");
1647
1648                 if (device->features & DASD_FEATURE_ERPLOG)
1649                         device->discipline->dump_sense(device, cqr, irb);
1650                 device->discipline->check_for_device_change(device, cqr, irb);
1651                 dasd_put_device(device);
1652         }
1653
1654         /* check for for attention message */
1655         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1656                 device = dasd_device_from_cdev_locked(cdev);
1657                 if (!IS_ERR(device)) {
1658                         device->discipline->check_attention(device,
1659                                                             irb->esw.esw1.lpum);
1660                         dasd_put_device(device);
1661                 }
1662         }
1663
1664         if (!cqr)
1665                 return;
1666
1667         device = (struct dasd_device *) cqr->startdev;
1668         if (!device ||
1669             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1670                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1671                                 "invalid device in request");
1672                 return;
1673         }
1674
1675         /* Check for clear pending */
1676         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1677             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1678                 cqr->status = DASD_CQR_CLEARED;
1679                 dasd_device_clear_timer(device);
1680                 wake_up(&dasd_flush_wq);
1681                 dasd_schedule_device_bh(device);
1682                 return;
1683         }
1684
1685         /* check status - the request might have been killed by dyn detach */
1686         if (cqr->status != DASD_CQR_IN_IO) {
1687                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1688                               "status %02x", dev_name(&cdev->dev), cqr->status);
1689                 return;
1690         }
1691
1692         next = NULL;
1693         expires = 0;
1694         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1695             scsw_cstat(&irb->scsw) == 0) {
1696                 /* request was completed successfully */
1697                 cqr->status = DASD_CQR_SUCCESS;
1698                 cqr->stopclk = now;
1699                 /* Start first request on queue if possible -> fast_io. */
1700                 if (cqr->devlist.next != &device->ccw_queue) {
1701                         next = list_entry(cqr->devlist.next,
1702                                           struct dasd_ccw_req, devlist);
1703                 }
1704         } else {  /* error */
1705                 /* check for HPF error
1706                  * call discipline function to requeue all requests
1707                  * and disable HPF accordingly
1708                  */
1709                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1710                     device->discipline->handle_hpf_error)
1711                         device->discipline->handle_hpf_error(device, irb);
1712                 /*
1713                  * If we don't want complex ERP for this request, then just
1714                  * reset this and retry it in the fastpath
1715                  */
1716                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1717                     cqr->retries > 0) {
1718                         if (cqr->lpm == dasd_path_get_opm(device))
1719                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1720                                               "default ERP in fastpath "
1721                                               "(%i retries left)",
1722                                               cqr->retries);
1723                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1724                                 cqr->lpm = dasd_path_get_opm(device);
1725                         cqr->status = DASD_CQR_QUEUED;
1726                         next = cqr;
1727                 } else
1728                         cqr->status = DASD_CQR_ERROR;
1729         }
1730         if (next && (next->status == DASD_CQR_QUEUED) &&
1731             (!device->stopped)) {
1732                 if (device->discipline->start_IO(next) == 0)
1733                         expires = next->expires;
1734         }
1735         if (expires != 0)
1736                 dasd_device_set_timer(device, expires);
1737         else
1738                 dasd_device_clear_timer(device);
1739         dasd_schedule_device_bh(device);
1740 }
1741 EXPORT_SYMBOL(dasd_int_handler);
1742
1743 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1744 {
1745         struct dasd_device *device;
1746
1747         device = dasd_device_from_cdev_locked(cdev);
1748
1749         if (IS_ERR(device))
1750                 goto out;
1751         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1752            device->state != device->target ||
1753            !device->discipline->check_for_device_change){
1754                 dasd_put_device(device);
1755                 goto out;
1756         }
1757         if (device->discipline->dump_sense_dbf)
1758                 device->discipline->dump_sense_dbf(device, irb, "uc");
1759         device->discipline->check_for_device_change(device, NULL, irb);
1760         dasd_put_device(device);
1761 out:
1762         return UC_TODO_RETRY;
1763 }
1764 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1765
1766 /*
1767  * If we have an error on a dasd_block layer request then we cancel
1768  * and return all further requests from the same dasd_block as well.
1769  */
1770 static void __dasd_device_recovery(struct dasd_device *device,
1771                                    struct dasd_ccw_req *ref_cqr)
1772 {
1773         struct list_head *l, *n;
1774         struct dasd_ccw_req *cqr;
1775
1776         /*
1777          * only requeue request that came from the dasd_block layer
1778          */
1779         if (!ref_cqr->block)
1780                 return;
1781
1782         list_for_each_safe(l, n, &device->ccw_queue) {
1783                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1784                 if (cqr->status == DASD_CQR_QUEUED &&
1785                     ref_cqr->block == cqr->block) {
1786                         cqr->status = DASD_CQR_CLEARED;
1787                 }
1788         }
1789 };
1790
1791 /*
1792  * Remove those ccw requests from the queue that need to be returned
1793  * to the upper layer.
1794  */
1795 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1796                                             struct list_head *final_queue)
1797 {
1798         struct list_head *l, *n;
1799         struct dasd_ccw_req *cqr;
1800
1801         /* Process request with final status. */
1802         list_for_each_safe(l, n, &device->ccw_queue) {
1803                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1804
1805                 /* Skip any non-final request. */
1806                 if (cqr->status == DASD_CQR_QUEUED ||
1807                     cqr->status == DASD_CQR_IN_IO ||
1808                     cqr->status == DASD_CQR_CLEAR_PENDING)
1809                         continue;
1810                 if (cqr->status == DASD_CQR_ERROR) {
1811                         __dasd_device_recovery(device, cqr);
1812                 }
1813                 /* Rechain finished requests to final queue */
1814                 list_move_tail(&cqr->devlist, final_queue);
1815         }
1816 }
1817
1818 static void __dasd_process_cqr(struct dasd_device *device,
1819                                struct dasd_ccw_req *cqr)
1820 {
1821         char errorstring[ERRORLENGTH];
1822
1823         switch (cqr->status) {
1824         case DASD_CQR_SUCCESS:
1825                 cqr->status = DASD_CQR_DONE;
1826                 break;
1827         case DASD_CQR_ERROR:
1828                 cqr->status = DASD_CQR_NEED_ERP;
1829                 break;
1830         case DASD_CQR_CLEARED:
1831                 cqr->status = DASD_CQR_TERMINATED;
1832                 break;
1833         default:
1834                 /* internal error 12 - wrong cqr status*/
1835                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1836                 dev_err(&device->cdev->dev,
1837                         "An error occurred in the DASD device driver, "
1838                         "reason=%s\n", errorstring);
1839                 BUG();
1840         }
1841         if (cqr->callback)
1842                 cqr->callback(cqr, cqr->callback_data);
1843 }
1844
1845 /*
1846  * the cqrs from the final queue are returned to the upper layer
1847  * by setting a dasd_block state and calling the callback function
1848  */
1849 static void __dasd_device_process_final_queue(struct dasd_device *device,
1850                                               struct list_head *final_queue)
1851 {
1852         struct list_head *l, *n;
1853         struct dasd_ccw_req *cqr;
1854         struct dasd_block *block;
1855
1856         list_for_each_safe(l, n, final_queue) {
1857                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1858                 list_del_init(&cqr->devlist);
1859                 block = cqr->block;
1860                 if (!block) {
1861                         __dasd_process_cqr(device, cqr);
1862                 } else {
1863                         spin_lock_bh(&block->queue_lock);
1864                         __dasd_process_cqr(device, cqr);
1865                         spin_unlock_bh(&block->queue_lock);
1866                 }
1867         }
1868 }
1869
1870 /*
1871  * Take a look at the first request on the ccw queue and check
1872  * if it reached its expire time. If so, terminate the IO.
1873  */
1874 static void __dasd_device_check_expire(struct dasd_device *device)
1875 {
1876         struct dasd_ccw_req *cqr;
1877
1878         if (list_empty(&device->ccw_queue))
1879                 return;
1880         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1881         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1882             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1883                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1884                         /*
1885                          * IO in safe offline processing should not
1886                          * run out of retries
1887                          */
1888                         cqr->retries++;
1889                 }
1890                 if (device->discipline->term_IO(cqr) != 0) {
1891                         /* Hmpf, try again in 5 sec */
1892                         dev_err(&device->cdev->dev,
1893                                 "cqr %p timed out (%lus) but cannot be "
1894                                 "ended, retrying in 5 s\n",
1895                                 cqr, (cqr->expires/HZ));
1896                         cqr->expires += 5*HZ;
1897                         dasd_device_set_timer(device, 5*HZ);
1898                 } else {
1899                         dev_err(&device->cdev->dev,
1900                                 "cqr %p timed out (%lus), %i retries "
1901                                 "remaining\n", cqr, (cqr->expires/HZ),
1902                                 cqr->retries);
1903                 }
1904         }
1905 }
1906
1907 /*
1908  * return 1 when device is not eligible for IO
1909  */
1910 static int __dasd_device_is_unusable(struct dasd_device *device,
1911                                      struct dasd_ccw_req *cqr)
1912 {
1913         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1914
1915         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1916             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1917                 /*
1918                  * dasd is being set offline
1919                  * but it is no safe offline where we have to allow I/O
1920                  */
1921                 return 1;
1922         }
1923         if (device->stopped) {
1924                 if (device->stopped & mask) {
1925                         /* stopped and CQR will not change that. */
1926                         return 1;
1927                 }
1928                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1929                         /* CQR is not able to change device to
1930                          * operational. */
1931                         return 1;
1932                 }
1933                 /* CQR required to get device operational. */
1934         }
1935         return 0;
1936 }
1937
1938 /*
1939  * Take a look at the first request on the ccw queue and check
1940  * if it needs to be started.
1941  */
1942 static void __dasd_device_start_head(struct dasd_device *device)
1943 {
1944         struct dasd_ccw_req *cqr;
1945         int rc;
1946
1947         if (list_empty(&device->ccw_queue))
1948                 return;
1949         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1950         if (cqr->status != DASD_CQR_QUEUED)
1951                 return;
1952         /* if device is not usable return request to upper layer */
1953         if (__dasd_device_is_unusable(device, cqr)) {
1954                 cqr->intrc = -EAGAIN;
1955                 cqr->status = DASD_CQR_CLEARED;
1956                 dasd_schedule_device_bh(device);
1957                 return;
1958         }
1959
1960         rc = device->discipline->start_IO(cqr);
1961         if (rc == 0)
1962                 dasd_device_set_timer(device, cqr->expires);
1963         else if (rc == -EACCES) {
1964                 dasd_schedule_device_bh(device);
1965         } else
1966                 /* Hmpf, try again in 1/2 sec */
1967                 dasd_device_set_timer(device, 50);
1968 }
1969
1970 static void __dasd_device_check_path_events(struct dasd_device *device)
1971 {
1972         int rc;
1973
1974         if (!dasd_path_get_tbvpm(device))
1975                 return;
1976
1977         if (device->stopped &
1978             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1979                 return;
1980         rc = device->discipline->verify_path(device,
1981                                              dasd_path_get_tbvpm(device));
1982         if (rc)
1983                 dasd_device_set_timer(device, 50);
1984         else
1985                 dasd_path_clear_all_verify(device);
1986 };
1987
1988 /*
1989  * Go through all request on the dasd_device request queue,
1990  * terminate them on the cdev if necessary, and return them to the
1991  * submitting layer via callback.
1992  * Note:
1993  * Make sure that all 'submitting layers' still exist when
1994  * this function is called!. In other words, when 'device' is a base
1995  * device then all block layer requests must have been removed before
1996  * via dasd_flush_block_queue.
1997  */
1998 int dasd_flush_device_queue(struct dasd_device *device)
1999 {
2000         struct dasd_ccw_req *cqr, *n;
2001         int rc;
2002         struct list_head flush_queue;
2003
2004         INIT_LIST_HEAD(&flush_queue);
2005         spin_lock_irq(get_ccwdev_lock(device->cdev));
2006         rc = 0;
2007         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2008                 /* Check status and move request to flush_queue */
2009                 switch (cqr->status) {
2010                 case DASD_CQR_IN_IO:
2011                         rc = device->discipline->term_IO(cqr);
2012                         if (rc) {
2013                                 /* unable to terminate requeust */
2014                                 dev_err(&device->cdev->dev,
2015                                         "Flushing the DASD request queue "
2016                                         "failed for request %p\n", cqr);
2017                                 /* stop flush processing */
2018                                 goto finished;
2019                         }
2020                         break;
2021                 case DASD_CQR_QUEUED:
2022                         cqr->stopclk = get_tod_clock();
2023                         cqr->status = DASD_CQR_CLEARED;
2024                         break;
2025                 default: /* no need to modify the others */
2026                         break;
2027                 }
2028                 list_move_tail(&cqr->devlist, &flush_queue);
2029         }
2030 finished:
2031         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2032         /*
2033          * After this point all requests must be in state CLEAR_PENDING,
2034          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2035          * one of the others.
2036          */
2037         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2038                 wait_event(dasd_flush_wq,
2039                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2040         /*
2041          * Now set each request back to TERMINATED, DONE or NEED_ERP
2042          * and call the callback function of flushed requests
2043          */
2044         __dasd_device_process_final_queue(device, &flush_queue);
2045         return rc;
2046 }
2047 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2048
2049 /*
2050  * Acquire the device lock and process queues for the device.
2051  */
2052 static void dasd_device_tasklet(unsigned long data)
2053 {
2054         struct dasd_device *device = (struct dasd_device *) data;
2055         struct list_head final_queue;
2056
2057         atomic_set (&device->tasklet_scheduled, 0);
2058         INIT_LIST_HEAD(&final_queue);
2059         spin_lock_irq(get_ccwdev_lock(device->cdev));
2060         /* Check expire time of first request on the ccw queue. */
2061         __dasd_device_check_expire(device);
2062         /* find final requests on ccw queue */
2063         __dasd_device_process_ccw_queue(device, &final_queue);
2064         __dasd_device_check_path_events(device);
2065         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2066         /* Now call the callback function of requests with final status */
2067         __dasd_device_process_final_queue(device, &final_queue);
2068         spin_lock_irq(get_ccwdev_lock(device->cdev));
2069         /* Now check if the head of the ccw queue needs to be started. */
2070         __dasd_device_start_head(device);
2071         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2072         if (waitqueue_active(&shutdown_waitq))
2073                 wake_up(&shutdown_waitq);
2074         dasd_put_device(device);
2075 }
2076
2077 /*
2078  * Schedules a call to dasd_tasklet over the device tasklet.
2079  */
2080 void dasd_schedule_device_bh(struct dasd_device *device)
2081 {
2082         /* Protect against rescheduling. */
2083         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2084                 return;
2085         dasd_get_device(device);
2086         tasklet_hi_schedule(&device->tasklet);
2087 }
2088 EXPORT_SYMBOL(dasd_schedule_device_bh);
2089
2090 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2091 {
2092         device->stopped |= bits;
2093 }
2094 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2095
2096 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2097 {
2098         device->stopped &= ~bits;
2099         if (!device->stopped)
2100                 wake_up(&generic_waitq);
2101 }
2102 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2103
2104 /*
2105  * Queue a request to the head of the device ccw_queue.
2106  * Start the I/O if possible.
2107  */
2108 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2109 {
2110         struct dasd_device *device;
2111         unsigned long flags;
2112
2113         device = cqr->startdev;
2114         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2115         cqr->status = DASD_CQR_QUEUED;
2116         list_add(&cqr->devlist, &device->ccw_queue);
2117         /* let the bh start the request to keep them in order */
2118         dasd_schedule_device_bh(device);
2119         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2120 }
2121 EXPORT_SYMBOL(dasd_add_request_head);
2122
2123 /*
2124  * Queue a request to the tail of the device ccw_queue.
2125  * Start the I/O if possible.
2126  */
2127 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2128 {
2129         struct dasd_device *device;
2130         unsigned long flags;
2131
2132         device = cqr->startdev;
2133         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2134         cqr->status = DASD_CQR_QUEUED;
2135         list_add_tail(&cqr->devlist, &device->ccw_queue);
2136         /* let the bh start the request to keep them in order */
2137         dasd_schedule_device_bh(device);
2138         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2139 }
2140 EXPORT_SYMBOL(dasd_add_request_tail);
2141
2142 /*
2143  * Wakeup helper for the 'sleep_on' functions.
2144  */
2145 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2146 {
2147         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2148         cqr->callback_data = DASD_SLEEPON_END_TAG;
2149         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2150         wake_up(&generic_waitq);
2151 }
2152 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2153
2154 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2155 {
2156         struct dasd_device *device;
2157         int rc;
2158
2159         device = cqr->startdev;
2160         spin_lock_irq(get_ccwdev_lock(device->cdev));
2161         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2162         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2163         return rc;
2164 }
2165
2166 /*
2167  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2168  */
2169 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2170 {
2171         struct dasd_device *device;
2172         dasd_erp_fn_t erp_fn;
2173
2174         if (cqr->status == DASD_CQR_FILLED)
2175                 return 0;
2176         device = cqr->startdev;
2177         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2178                 if (cqr->status == DASD_CQR_TERMINATED) {
2179                         device->discipline->handle_terminated_request(cqr);
2180                         return 1;
2181                 }
2182                 if (cqr->status == DASD_CQR_NEED_ERP) {
2183                         erp_fn = device->discipline->erp_action(cqr);
2184                         erp_fn(cqr);
2185                         return 1;
2186                 }
2187                 if (cqr->status == DASD_CQR_FAILED)
2188                         dasd_log_sense(cqr, &cqr->irb);
2189                 if (cqr->refers) {
2190                         __dasd_process_erp(device, cqr);
2191                         return 1;
2192                 }
2193         }
2194         return 0;
2195 }
2196
2197 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2198 {
2199         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2200                 if (cqr->refers) /* erp is not done yet */
2201                         return 1;
2202                 return ((cqr->status != DASD_CQR_DONE) &&
2203                         (cqr->status != DASD_CQR_FAILED));
2204         } else
2205                 return (cqr->status == DASD_CQR_FILLED);
2206 }
2207
2208 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2209 {
2210         struct dasd_device *device;
2211         int rc;
2212         struct list_head ccw_queue;
2213         struct dasd_ccw_req *cqr;
2214
2215         INIT_LIST_HEAD(&ccw_queue);
2216         maincqr->status = DASD_CQR_FILLED;
2217         device = maincqr->startdev;
2218         list_add(&maincqr->blocklist, &ccw_queue);
2219         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2220              cqr = list_first_entry(&ccw_queue,
2221                                     struct dasd_ccw_req, blocklist)) {
2222
2223                 if (__dasd_sleep_on_erp(cqr))
2224                         continue;
2225                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2226                         continue;
2227                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2228                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2229                         cqr->status = DASD_CQR_FAILED;
2230                         cqr->intrc = -EPERM;
2231                         continue;
2232                 }
2233                 /* Non-temporary stop condition will trigger fail fast */
2234                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2235                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2236                     (!dasd_eer_enabled(device))) {
2237                         cqr->status = DASD_CQR_FAILED;
2238                         cqr->intrc = -ENOLINK;
2239                         continue;
2240                 }
2241                 /*
2242                  * Don't try to start requests if device is in
2243                  * offline processing, it might wait forever
2244                  */
2245                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2246                         cqr->status = DASD_CQR_FAILED;
2247                         cqr->intrc = -ENODEV;
2248                         continue;
2249                 }
2250                 /*
2251                  * Don't try to start requests if device is stopped
2252                  * except path verification requests
2253                  */
2254                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2255                         if (interruptible) {
2256                                 rc = wait_event_interruptible(
2257                                         generic_waitq, !(device->stopped));
2258                                 if (rc == -ERESTARTSYS) {
2259                                         cqr->status = DASD_CQR_FAILED;
2260                                         maincqr->intrc = rc;
2261                                         continue;
2262                                 }
2263                         } else
2264                                 wait_event(generic_waitq, !(device->stopped));
2265                 }
2266                 if (!cqr->callback)
2267                         cqr->callback = dasd_wakeup_cb;
2268
2269                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2270                 dasd_add_request_tail(cqr);
2271                 if (interruptible) {
2272                         rc = wait_event_interruptible(
2273                                 generic_waitq, _wait_for_wakeup(cqr));
2274                         if (rc == -ERESTARTSYS) {
2275                                 dasd_cancel_req(cqr);
2276                                 /* wait (non-interruptible) for final status */
2277                                 wait_event(generic_waitq,
2278                                            _wait_for_wakeup(cqr));
2279                                 cqr->status = DASD_CQR_FAILED;
2280                                 maincqr->intrc = rc;
2281                                 continue;
2282                         }
2283                 } else
2284                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2285         }
2286
2287         maincqr->endclk = get_tod_clock();
2288         if ((maincqr->status != DASD_CQR_DONE) &&
2289             (maincqr->intrc != -ERESTARTSYS))
2290                 dasd_log_sense(maincqr, &maincqr->irb);
2291         if (maincqr->status == DASD_CQR_DONE)
2292                 rc = 0;
2293         else if (maincqr->intrc)
2294                 rc = maincqr->intrc;
2295         else
2296                 rc = -EIO;
2297         return rc;
2298 }
2299
2300 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2301 {
2302         struct dasd_ccw_req *cqr;
2303
2304         list_for_each_entry(cqr, ccw_queue, blocklist) {
2305                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2306                         return 0;
2307         }
2308
2309         return 1;
2310 }
2311
2312 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2313 {
2314         struct dasd_device *device;
2315         struct dasd_ccw_req *cqr, *n;
2316         u8 *sense = NULL;
2317         int rc;
2318
2319 retry:
2320         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2321                 device = cqr->startdev;
2322                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2323                         continue;
2324
2325                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2326                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2327                         cqr->status = DASD_CQR_FAILED;
2328                         cqr->intrc = -EPERM;
2329                         continue;
2330                 }
2331                 /*Non-temporary stop condition will trigger fail fast*/
2332                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2333                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2334                     !dasd_eer_enabled(device)) {
2335                         cqr->status = DASD_CQR_FAILED;
2336                         cqr->intrc = -EAGAIN;
2337                         continue;
2338                 }
2339
2340                 /*Don't try to start requests if device is stopped*/
2341                 if (interruptible) {
2342                         rc = wait_event_interruptible(
2343                                 generic_waitq, !device->stopped);
2344                         if (rc == -ERESTARTSYS) {
2345                                 cqr->status = DASD_CQR_FAILED;
2346                                 cqr->intrc = rc;
2347                                 continue;
2348                         }
2349                 } else
2350                         wait_event(generic_waitq, !(device->stopped));
2351
2352                 if (!cqr->callback)
2353                         cqr->callback = dasd_wakeup_cb;
2354                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2355                 dasd_add_request_tail(cqr);
2356         }
2357
2358         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2359
2360         rc = 0;
2361         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2362                 /*
2363                  * In some cases the 'File Protected' or 'Incorrect Length'
2364                  * error might be expected and error recovery would be
2365                  * unnecessary in these cases.  Check if the according suppress
2366                  * bit is set.
2367                  */
2368                 sense = dasd_get_sense(&cqr->irb);
2369                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2370                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2371                         continue;
2372                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2373                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2374                         continue;
2375
2376                 /*
2377                  * for alias devices simplify error recovery and
2378                  * return to upper layer
2379                  * do not skip ERP requests
2380                  */
2381                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2382                     (cqr->status == DASD_CQR_TERMINATED ||
2383                      cqr->status == DASD_CQR_NEED_ERP))
2384                         return -EAGAIN;
2385
2386                 /* normal recovery for basedev IO */
2387                 if (__dasd_sleep_on_erp(cqr))
2388                         /* handle erp first */
2389                         goto retry;
2390         }
2391
2392         return 0;
2393 }
2394
2395 /*
2396  * Queue a request to the tail of the device ccw_queue and wait for
2397  * it's completion.
2398  */
2399 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2400 {
2401         return _dasd_sleep_on(cqr, 0);
2402 }
2403 EXPORT_SYMBOL(dasd_sleep_on);
2404
2405 /*
2406  * Start requests from a ccw_queue and wait for their completion.
2407  */
2408 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2409 {
2410         return _dasd_sleep_on_queue(ccw_queue, 0);
2411 }
2412 EXPORT_SYMBOL(dasd_sleep_on_queue);
2413
2414 /*
2415  * Queue a request to the tail of the device ccw_queue and wait
2416  * interruptible for it's completion.
2417  */
2418 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2419 {
2420         return _dasd_sleep_on(cqr, 1);
2421 }
2422 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2423
2424 /*
2425  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2426  * for eckd devices) the currently running request has to be terminated
2427  * and be put back to status queued, before the special request is added
2428  * to the head of the queue. Then the special request is waited on normally.
2429  */
2430 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2431 {
2432         struct dasd_ccw_req *cqr;
2433         int rc;
2434
2435         if (list_empty(&device->ccw_queue))
2436                 return 0;
2437         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2438         rc = device->discipline->term_IO(cqr);
2439         if (!rc)
2440                 /*
2441                  * CQR terminated because a more important request is pending.
2442                  * Undo decreasing of retry counter because this is
2443                  * not an error case.
2444                  */
2445                 cqr->retries++;
2446         return rc;
2447 }
2448
2449 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2450 {
2451         struct dasd_device *device;
2452         int rc;
2453
2454         device = cqr->startdev;
2455         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2456             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2457                 cqr->status = DASD_CQR_FAILED;
2458                 cqr->intrc = -EPERM;
2459                 return -EIO;
2460         }
2461         spin_lock_irq(get_ccwdev_lock(device->cdev));
2462         rc = _dasd_term_running_cqr(device);
2463         if (rc) {
2464                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2465                 return rc;
2466         }
2467         cqr->callback = dasd_wakeup_cb;
2468         cqr->callback_data = DASD_SLEEPON_START_TAG;
2469         cqr->status = DASD_CQR_QUEUED;
2470         /*
2471          * add new request as second
2472          * first the terminated cqr needs to be finished
2473          */
2474         list_add(&cqr->devlist, device->ccw_queue.next);
2475
2476         /* let the bh start the request to keep them in order */
2477         dasd_schedule_device_bh(device);
2478
2479         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2480
2481         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2482
2483         if (cqr->status == DASD_CQR_DONE)
2484                 rc = 0;
2485         else if (cqr->intrc)
2486                 rc = cqr->intrc;
2487         else
2488                 rc = -EIO;
2489
2490         /* kick tasklets */
2491         dasd_schedule_device_bh(device);
2492         if (device->block)
2493                 dasd_schedule_block_bh(device->block);
2494
2495         return rc;
2496 }
2497 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2498
2499 /*
2500  * Cancels a request that was started with dasd_sleep_on_req.
2501  * This is useful to timeout requests. The request will be
2502  * terminated if it is currently in i/o.
2503  * Returns 0 if request termination was successful
2504  *         negative error code if termination failed
2505  * Cancellation of a request is an asynchronous operation! The calling
2506  * function has to wait until the request is properly returned via callback.
2507  */
2508 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2509 {
2510         struct dasd_device *device = cqr->startdev;
2511         int rc = 0;
2512
2513         switch (cqr->status) {
2514         case DASD_CQR_QUEUED:
2515                 /* request was not started - just set to cleared */
2516                 cqr->status = DASD_CQR_CLEARED;
2517                 break;
2518         case DASD_CQR_IN_IO:
2519                 /* request in IO - terminate IO and release again */
2520                 rc = device->discipline->term_IO(cqr);
2521                 if (rc) {
2522                         dev_err(&device->cdev->dev,
2523                                 "Cancelling request %p failed with rc=%d\n",
2524                                 cqr, rc);
2525                 } else {
2526                         cqr->stopclk = get_tod_clock();
2527                 }
2528                 break;
2529         default: /* already finished or clear pending - do nothing */
2530                 break;
2531         }
2532         dasd_schedule_device_bh(device);
2533         return rc;
2534 }
2535
2536 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2537 {
2538         struct dasd_device *device = cqr->startdev;
2539         unsigned long flags;
2540         int rc;
2541
2542         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2543         rc = __dasd_cancel_req(cqr);
2544         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2545         return rc;
2546 }
2547
2548 /*
2549  * SECTION: Operations of the dasd_block layer.
2550  */
2551
2552 /*
2553  * Timeout function for dasd_block. This is used when the block layer
2554  * is waiting for something that may not come reliably, (e.g. a state
2555  * change interrupt)
2556  */
2557 static void dasd_block_timeout(struct timer_list *t)
2558 {
2559         unsigned long flags;
2560         struct dasd_block *block;
2561
2562         block = from_timer(block, t, timer);
2563         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2564         /* re-activate request queue */
2565         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2566         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2567         dasd_schedule_block_bh(block);
2568         blk_mq_run_hw_queues(block->request_queue, true);
2569 }
2570
2571 /*
2572  * Setup timeout for a dasd_block in jiffies.
2573  */
2574 void dasd_block_set_timer(struct dasd_block *block, int expires)
2575 {
2576         if (expires == 0)
2577                 del_timer(&block->timer);
2578         else
2579                 mod_timer(&block->timer, jiffies + expires);
2580 }
2581 EXPORT_SYMBOL(dasd_block_set_timer);
2582
2583 /*
2584  * Clear timeout for a dasd_block.
2585  */
2586 void dasd_block_clear_timer(struct dasd_block *block)
2587 {
2588         del_timer(&block->timer);
2589 }
2590 EXPORT_SYMBOL(dasd_block_clear_timer);
2591
2592 /*
2593  * Process finished error recovery ccw.
2594  */
2595 static void __dasd_process_erp(struct dasd_device *device,
2596                                struct dasd_ccw_req *cqr)
2597 {
2598         dasd_erp_fn_t erp_fn;
2599
2600         if (cqr->status == DASD_CQR_DONE)
2601                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2602         else
2603                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2604         erp_fn = device->discipline->erp_postaction(cqr);
2605         erp_fn(cqr);
2606 }
2607
2608 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2609 {
2610         struct request *req;
2611         blk_status_t error = BLK_STS_OK;
2612         int status;
2613
2614         req = (struct request *) cqr->callback_data;
2615         dasd_profile_end(cqr->block, cqr, req);
2616
2617         status = cqr->block->base->discipline->free_cp(cqr, req);
2618         if (status < 0)
2619                 error = errno_to_blk_status(status);
2620         else if (status == 0) {
2621                 switch (cqr->intrc) {
2622                 case -EPERM:
2623                         error = BLK_STS_NEXUS;
2624                         break;
2625                 case -ENOLINK:
2626                         error = BLK_STS_TRANSPORT;
2627                         break;
2628                 case -ETIMEDOUT:
2629                         error = BLK_STS_TIMEOUT;
2630                         break;
2631                 default:
2632                         error = BLK_STS_IOERR;
2633                         break;
2634                 }
2635         }
2636
2637         /*
2638          * We need to take care for ETIMEDOUT errors here since the
2639          * complete callback does not get called in this case.
2640          * Take care of all errors here and avoid additional code to
2641          * transfer the error value to the complete callback.
2642          */
2643         if (error) {
2644                 blk_mq_end_request(req, error);
2645                 blk_mq_run_hw_queues(req->q, true);
2646         } else {
2647                 blk_mq_complete_request(req);
2648         }
2649 }
2650
2651 /*
2652  * Process ccw request queue.
2653  */
2654 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2655                                            struct list_head *final_queue)
2656 {
2657         struct list_head *l, *n;
2658         struct dasd_ccw_req *cqr;
2659         dasd_erp_fn_t erp_fn;
2660         unsigned long flags;
2661         struct dasd_device *base = block->base;
2662
2663 restart:
2664         /* Process request with final status. */
2665         list_for_each_safe(l, n, &block->ccw_queue) {
2666                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2667                 if (cqr->status != DASD_CQR_DONE &&
2668                     cqr->status != DASD_CQR_FAILED &&
2669                     cqr->status != DASD_CQR_NEED_ERP &&
2670                     cqr->status != DASD_CQR_TERMINATED)
2671                         continue;
2672
2673                 if (cqr->status == DASD_CQR_TERMINATED) {
2674                         base->discipline->handle_terminated_request(cqr);
2675                         goto restart;
2676                 }
2677
2678                 /*  Process requests that may be recovered */
2679                 if (cqr->status == DASD_CQR_NEED_ERP) {
2680                         erp_fn = base->discipline->erp_action(cqr);
2681                         if (IS_ERR(erp_fn(cqr)))
2682                                 continue;
2683                         goto restart;
2684                 }
2685
2686                 /* log sense for fatal error */
2687                 if (cqr->status == DASD_CQR_FAILED) {
2688                         dasd_log_sense(cqr, &cqr->irb);
2689                 }
2690
2691                 /* First of all call extended error reporting. */
2692                 if (dasd_eer_enabled(base) &&
2693                     cqr->status == DASD_CQR_FAILED) {
2694                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2695
2696                         /* restart request  */
2697                         cqr->status = DASD_CQR_FILLED;
2698                         cqr->retries = 255;
2699                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2700                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2701                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2702                                                flags);
2703                         goto restart;
2704                 }
2705
2706                 /* Process finished ERP request. */
2707                 if (cqr->refers) {
2708                         __dasd_process_erp(base, cqr);
2709                         goto restart;
2710                 }
2711
2712                 /* Rechain finished requests to final queue */
2713                 cqr->endclk = get_tod_clock();
2714                 list_move_tail(&cqr->blocklist, final_queue);
2715         }
2716 }
2717
2718 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2719 {
2720         dasd_schedule_block_bh(cqr->block);
2721 }
2722
2723 static void __dasd_block_start_head(struct dasd_block *block)
2724 {
2725         struct dasd_ccw_req *cqr;
2726
2727         if (list_empty(&block->ccw_queue))
2728                 return;
2729         /* We allways begin with the first requests on the queue, as some
2730          * of previously started requests have to be enqueued on a
2731          * dasd_device again for error recovery.
2732          */
2733         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2734                 if (cqr->status != DASD_CQR_FILLED)
2735                         continue;
2736                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2737                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2738                         cqr->status = DASD_CQR_FAILED;
2739                         cqr->intrc = -EPERM;
2740                         dasd_schedule_block_bh(block);
2741                         continue;
2742                 }
2743                 /* Non-temporary stop condition will trigger fail fast */
2744                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2745                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2746                     (!dasd_eer_enabled(block->base))) {
2747                         cqr->status = DASD_CQR_FAILED;
2748                         cqr->intrc = -ENOLINK;
2749                         dasd_schedule_block_bh(block);
2750                         continue;
2751                 }
2752                 /* Don't try to start requests if device is stopped */
2753                 if (block->base->stopped)
2754                         return;
2755
2756                 /* just a fail safe check, should not happen */
2757                 if (!cqr->startdev)
2758                         cqr->startdev = block->base;
2759
2760                 /* make sure that the requests we submit find their way back */
2761                 cqr->callback = dasd_return_cqr_cb;
2762
2763                 dasd_add_request_tail(cqr);
2764         }
2765 }
2766
2767 /*
2768  * Central dasd_block layer routine. Takes requests from the generic
2769  * block layer request queue, creates ccw requests, enqueues them on
2770  * a dasd_device and processes ccw requests that have been returned.
2771  */
2772 static void dasd_block_tasklet(unsigned long data)
2773 {
2774         struct dasd_block *block = (struct dasd_block *) data;
2775         struct list_head final_queue;
2776         struct list_head *l, *n;
2777         struct dasd_ccw_req *cqr;
2778         struct dasd_queue *dq;
2779
2780         atomic_set(&block->tasklet_scheduled, 0);
2781         INIT_LIST_HEAD(&final_queue);
2782         spin_lock_irq(&block->queue_lock);
2783         /* Finish off requests on ccw queue */
2784         __dasd_process_block_ccw_queue(block, &final_queue);
2785         spin_unlock_irq(&block->queue_lock);
2786
2787         /* Now call the callback function of requests with final status */
2788         list_for_each_safe(l, n, &final_queue) {
2789                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2790                 dq = cqr->dq;
2791                 spin_lock_irq(&dq->lock);
2792                 list_del_init(&cqr->blocklist);
2793                 __dasd_cleanup_cqr(cqr);
2794                 spin_unlock_irq(&dq->lock);
2795         }
2796
2797         spin_lock_irq(&block->queue_lock);
2798         /* Now check if the head of the ccw queue needs to be started. */
2799         __dasd_block_start_head(block);
2800         spin_unlock_irq(&block->queue_lock);
2801
2802         if (waitqueue_active(&shutdown_waitq))
2803                 wake_up(&shutdown_waitq);
2804         dasd_put_device(block->base);
2805 }
2806
2807 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2808 {
2809         wake_up(&dasd_flush_wq);
2810 }
2811
2812 /*
2813  * Requeue a request back to the block request queue
2814  * only works for block requests
2815  */
2816 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2817 {
2818         struct dasd_block *block = cqr->block;
2819         struct request *req;
2820
2821         if (!block)
2822                 return -EINVAL;
2823         spin_lock_irq(&cqr->dq->lock);
2824         req = (struct request *) cqr->callback_data;
2825         blk_mq_requeue_request(req, false);
2826         spin_unlock_irq(&cqr->dq->lock);
2827
2828         return 0;
2829 }
2830
2831 /*
2832  * Go through all request on the dasd_block request queue, cancel them
2833  * on the respective dasd_device, and return them to the generic
2834  * block layer.
2835  */
2836 static int dasd_flush_block_queue(struct dasd_block *block)
2837 {
2838         struct dasd_ccw_req *cqr, *n;
2839         int rc, i;
2840         struct list_head flush_queue;
2841         unsigned long flags;
2842
2843         INIT_LIST_HEAD(&flush_queue);
2844         spin_lock_bh(&block->queue_lock);
2845         rc = 0;
2846 restart:
2847         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2848                 /* if this request currently owned by a dasd_device cancel it */
2849                 if (cqr->status >= DASD_CQR_QUEUED)
2850                         rc = dasd_cancel_req(cqr);
2851                 if (rc < 0)
2852                         break;
2853                 /* Rechain request (including erp chain) so it won't be
2854                  * touched by the dasd_block_tasklet anymore.
2855                  * Replace the callback so we notice when the request
2856                  * is returned from the dasd_device layer.
2857                  */
2858                 cqr->callback = _dasd_wake_block_flush_cb;
2859                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2860                         list_move_tail(&cqr->blocklist, &flush_queue);
2861                 if (i > 1)
2862                         /* moved more than one request - need to restart */
2863                         goto restart;
2864         }
2865         spin_unlock_bh(&block->queue_lock);
2866         /* Now call the callback function of flushed requests */
2867 restart_cb:
2868         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2869                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2870                 /* Process finished ERP request. */
2871                 if (cqr->refers) {
2872                         spin_lock_bh(&block->queue_lock);
2873                         __dasd_process_erp(block->base, cqr);
2874                         spin_unlock_bh(&block->queue_lock);
2875                         /* restart list_for_xx loop since dasd_process_erp
2876                          * might remove multiple elements */
2877                         goto restart_cb;
2878                 }
2879                 /* call the callback function */
2880                 spin_lock_irqsave(&cqr->dq->lock, flags);
2881                 cqr->endclk = get_tod_clock();
2882                 list_del_init(&cqr->blocklist);
2883                 __dasd_cleanup_cqr(cqr);
2884                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
2885         }
2886         return rc;
2887 }
2888
2889 /*
2890  * Schedules a call to dasd_tasklet over the device tasklet.
2891  */
2892 void dasd_schedule_block_bh(struct dasd_block *block)
2893 {
2894         /* Protect against rescheduling. */
2895         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2896                 return;
2897         /* life cycle of block is bound to it's base device */
2898         dasd_get_device(block->base);
2899         tasklet_hi_schedule(&block->tasklet);
2900 }
2901 EXPORT_SYMBOL(dasd_schedule_block_bh);
2902
2903
2904 /*
2905  * SECTION: external block device operations
2906  * (request queue handling, open, release, etc.)
2907  */
2908
2909 /*
2910  * Dasd request queue function. Called from ll_rw_blk.c
2911  */
2912 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
2913                                     const struct blk_mq_queue_data *qd)
2914 {
2915         struct dasd_block *block = hctx->queue->queuedata;
2916         struct dasd_queue *dq = hctx->driver_data;
2917         struct request *req = qd->rq;
2918         struct dasd_device *basedev;
2919         struct dasd_ccw_req *cqr;
2920         blk_status_t rc = BLK_STS_OK;
2921
2922         basedev = block->base;
2923         spin_lock_irq(&dq->lock);
2924         if (basedev->state < DASD_STATE_READY) {
2925                 DBF_DEV_EVENT(DBF_ERR, basedev,
2926                               "device not ready for request %p", req);
2927                 rc = BLK_STS_IOERR;
2928                 goto out;
2929         }
2930
2931         /*
2932          * if device is stopped do not fetch new requests
2933          * except failfast is active which will let requests fail
2934          * immediately in __dasd_block_start_head()
2935          */
2936         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
2937                 DBF_DEV_EVENT(DBF_ERR, basedev,
2938                               "device stopped request %p", req);
2939                 rc = BLK_STS_RESOURCE;
2940                 goto out;
2941         }
2942
2943         if (basedev->features & DASD_FEATURE_READONLY &&
2944             rq_data_dir(req) == WRITE) {
2945                 DBF_DEV_EVENT(DBF_ERR, basedev,
2946                               "Rejecting write request %p", req);
2947                 rc = BLK_STS_IOERR;
2948                 goto out;
2949         }
2950
2951         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
2952             (basedev->features & DASD_FEATURE_FAILFAST ||
2953              blk_noretry_request(req))) {
2954                 DBF_DEV_EVENT(DBF_ERR, basedev,
2955                               "Rejecting failfast request %p", req);
2956                 rc = BLK_STS_IOERR;
2957                 goto out;
2958         }
2959
2960         cqr = basedev->discipline->build_cp(basedev, block, req);
2961         if (IS_ERR(cqr)) {
2962                 if (PTR_ERR(cqr) == -EBUSY ||
2963                     PTR_ERR(cqr) == -ENOMEM ||
2964                     PTR_ERR(cqr) == -EAGAIN) {
2965                         rc = BLK_STS_RESOURCE;
2966                         goto out;
2967                 }
2968                 DBF_DEV_EVENT(DBF_ERR, basedev,
2969                               "CCW creation failed (rc=%ld) on request %p",
2970                               PTR_ERR(cqr), req);
2971                 rc = BLK_STS_IOERR;
2972                 goto out;
2973         }
2974         /*
2975          *  Note: callback is set to dasd_return_cqr_cb in
2976          * __dasd_block_start_head to cover erp requests as well
2977          */
2978         cqr->callback_data = req;
2979         cqr->status = DASD_CQR_FILLED;
2980         cqr->dq = dq;
2981
2982         blk_mq_start_request(req);
2983         spin_lock(&block->queue_lock);
2984         list_add_tail(&cqr->blocklist, &block->ccw_queue);
2985         INIT_LIST_HEAD(&cqr->devlist);
2986         dasd_profile_start(block, cqr, req);
2987         dasd_schedule_block_bh(block);
2988         spin_unlock(&block->queue_lock);
2989
2990 out:
2991         spin_unlock_irq(&dq->lock);
2992         return rc;
2993 }
2994
2995 /*
2996  * Block timeout callback, called from the block layer
2997  *
2998  * Return values:
2999  * BLK_EH_RESET_TIMER if the request should be left running
3000  * BLK_EH_DONE if the request is handled or terminated
3001  *                    by the driver.
3002  */
3003 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3004 {
3005         struct dasd_block *block = req->q->queuedata;
3006         struct dasd_device *device;
3007         struct dasd_ccw_req *cqr;
3008         unsigned long flags;
3009         int rc = 0;
3010
3011         cqr = blk_mq_rq_to_pdu(req);
3012         if (!cqr)
3013                 return BLK_EH_DONE;
3014
3015         spin_lock_irqsave(&cqr->dq->lock, flags);
3016         device = cqr->startdev ? cqr->startdev : block->base;
3017         if (!device->blk_timeout) {
3018                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3019                 return BLK_EH_RESET_TIMER;
3020         }
3021         DBF_DEV_EVENT(DBF_WARNING, device,
3022                       " dasd_times_out cqr %p status %x",
3023                       cqr, cqr->status);
3024
3025         spin_lock(&block->queue_lock);
3026         spin_lock(get_ccwdev_lock(device->cdev));
3027         cqr->retries = -1;
3028         cqr->intrc = -ETIMEDOUT;
3029         if (cqr->status >= DASD_CQR_QUEUED) {
3030                 rc = __dasd_cancel_req(cqr);
3031         } else if (cqr->status == DASD_CQR_FILLED ||
3032                    cqr->status == DASD_CQR_NEED_ERP) {
3033                 cqr->status = DASD_CQR_TERMINATED;
3034         } else if (cqr->status == DASD_CQR_IN_ERP) {
3035                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3036
3037                 list_for_each_entry_safe(searchcqr, nextcqr,
3038                                          &block->ccw_queue, blocklist) {
3039                         tmpcqr = searchcqr;
3040                         while (tmpcqr->refers)
3041                                 tmpcqr = tmpcqr->refers;
3042                         if (tmpcqr != cqr)
3043                                 continue;
3044                         /* searchcqr is an ERP request for cqr */
3045                         searchcqr->retries = -1;
3046                         searchcqr->intrc = -ETIMEDOUT;
3047                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3048                                 rc = __dasd_cancel_req(searchcqr);
3049                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3050                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3051                                 searchcqr->status = DASD_CQR_TERMINATED;
3052                                 rc = 0;
3053                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3054                                 /*
3055                                  * Shouldn't happen; most recent ERP
3056                                  * request is at the front of queue
3057                                  */
3058                                 continue;
3059                         }
3060                         break;
3061                 }
3062         }
3063         spin_unlock(get_ccwdev_lock(device->cdev));
3064         dasd_schedule_block_bh(block);
3065         spin_unlock(&block->queue_lock);
3066         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3067
3068         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3069 }
3070
3071 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3072                           unsigned int idx)
3073 {
3074         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3075
3076         if (!dq)
3077                 return -ENOMEM;
3078
3079         spin_lock_init(&dq->lock);
3080         hctx->driver_data = dq;
3081
3082         return 0;
3083 }
3084
3085 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3086 {
3087         kfree(hctx->driver_data);
3088         hctx->driver_data = NULL;
3089 }
3090
3091 static void dasd_request_done(struct request *req)
3092 {
3093         blk_mq_end_request(req, 0);
3094         blk_mq_run_hw_queues(req->q, true);
3095 }
3096
3097 static struct blk_mq_ops dasd_mq_ops = {
3098         .queue_rq = do_dasd_request,
3099         .complete = dasd_request_done,
3100         .timeout = dasd_times_out,
3101         .init_hctx = dasd_init_hctx,
3102         .exit_hctx = dasd_exit_hctx,
3103 };
3104
3105 /*
3106  * Allocate and initialize request queue and default I/O scheduler.
3107  */
3108 static int dasd_alloc_queue(struct dasd_block *block)
3109 {
3110         int rc;
3111
3112         block->tag_set.ops = &dasd_mq_ops;
3113         block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3114         block->tag_set.nr_hw_queues = nr_hw_queues;
3115         block->tag_set.queue_depth = queue_depth;
3116         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3117         block->tag_set.numa_node = NUMA_NO_NODE;
3118
3119         rc = blk_mq_alloc_tag_set(&block->tag_set);
3120         if (rc)
3121                 return rc;
3122
3123         block->request_queue = blk_mq_init_queue(&block->tag_set);
3124         if (IS_ERR(block->request_queue))
3125                 return PTR_ERR(block->request_queue);
3126
3127         block->request_queue->queuedata = block;
3128
3129         return 0;
3130 }
3131
3132 /*
3133  * Allocate and initialize request queue.
3134  */
3135 static void dasd_setup_queue(struct dasd_block *block)
3136 {
3137         unsigned int logical_block_size = block->bp_block;
3138         struct request_queue *q = block->request_queue;
3139         unsigned int max_bytes, max_discard_sectors;
3140         int max;
3141
3142         if (block->base->features & DASD_FEATURE_USERAW) {
3143                 /*
3144                  * the max_blocks value for raw_track access is 256
3145                  * it is higher than the native ECKD value because we
3146                  * only need one ccw per track
3147                  * so the max_hw_sectors are
3148                  * 2048 x 512B = 1024kB = 16 tracks
3149                  */
3150                 max = 2048;
3151         } else {
3152                 max = block->base->discipline->max_blocks << block->s2b_shift;
3153         }
3154         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
3155         q->limits.max_dev_sectors = max;
3156         blk_queue_logical_block_size(q, logical_block_size);
3157         blk_queue_max_hw_sectors(q, max);
3158         blk_queue_max_segments(q, USHRT_MAX);
3159         /* with page sized segments we can translate each segement into
3160          * one idaw/tidaw
3161          */
3162         blk_queue_max_segment_size(q, PAGE_SIZE);
3163         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
3164
3165         /* Only activate blocklayer discard support for devices that support it */
3166         if (block->base->features & DASD_FEATURE_DISCARD) {
3167                 q->limits.discard_granularity = logical_block_size;
3168                 q->limits.discard_alignment = PAGE_SIZE;
3169
3170                 /* Calculate max_discard_sectors and make it PAGE aligned */
3171                 max_bytes = USHRT_MAX * logical_block_size;
3172                 max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
3173                 max_discard_sectors = max_bytes / logical_block_size;
3174
3175                 blk_queue_max_discard_sectors(q, max_discard_sectors);
3176                 blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
3177                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
3178         }
3179 }
3180
3181 /*
3182  * Deactivate and free request queue.
3183  */
3184 static void dasd_free_queue(struct dasd_block *block)
3185 {
3186         if (block->request_queue) {
3187                 blk_cleanup_queue(block->request_queue);
3188                 blk_mq_free_tag_set(&block->tag_set);
3189                 block->request_queue = NULL;
3190         }
3191 }
3192
3193 static int dasd_open(struct block_device *bdev, fmode_t mode)
3194 {
3195         struct dasd_device *base;
3196         int rc;
3197
3198         base = dasd_device_from_gendisk(bdev->bd_disk);
3199         if (!base)
3200                 return -ENODEV;
3201
3202         atomic_inc(&base->block->open_count);
3203         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3204                 rc = -ENODEV;
3205                 goto unlock;
3206         }
3207
3208         if (!try_module_get(base->discipline->owner)) {
3209                 rc = -EINVAL;
3210                 goto unlock;
3211         }
3212
3213         if (dasd_probeonly) {
3214                 dev_info(&base->cdev->dev,
3215                          "Accessing the DASD failed because it is in "
3216                          "probeonly mode\n");
3217                 rc = -EPERM;
3218                 goto out;
3219         }
3220
3221         if (base->state <= DASD_STATE_BASIC) {
3222                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3223                               " Cannot open unrecognized device");
3224                 rc = -ENODEV;
3225                 goto out;
3226         }
3227
3228         if ((mode & FMODE_WRITE) &&
3229             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3230              (base->features & DASD_FEATURE_READONLY))) {
3231                 rc = -EROFS;
3232                 goto out;
3233         }
3234
3235         dasd_put_device(base);
3236         return 0;
3237
3238 out:
3239         module_put(base->discipline->owner);
3240 unlock:
3241         atomic_dec(&base->block->open_count);
3242         dasd_put_device(base);
3243         return rc;
3244 }
3245
3246 static void dasd_release(struct gendisk *disk, fmode_t mode)
3247 {
3248         struct dasd_device *base = dasd_device_from_gendisk(disk);
3249         if (base) {
3250                 atomic_dec(&base->block->open_count);
3251                 module_put(base->discipline->owner);
3252                 dasd_put_device(base);
3253         }
3254 }
3255
3256 /*
3257  * Return disk geometry.
3258  */
3259 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3260 {
3261         struct dasd_device *base;
3262
3263         base = dasd_device_from_gendisk(bdev->bd_disk);
3264         if (!base)
3265                 return -ENODEV;
3266
3267         if (!base->discipline ||
3268             !base->discipline->fill_geometry) {
3269                 dasd_put_device(base);
3270                 return -EINVAL;
3271         }
3272         base->discipline->fill_geometry(base->block, geo);
3273         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3274         dasd_put_device(base);
3275         return 0;
3276 }
3277
3278 const struct block_device_operations
3279 dasd_device_operations = {
3280         .owner          = THIS_MODULE,
3281         .open           = dasd_open,
3282         .release        = dasd_release,
3283         .ioctl          = dasd_ioctl,
3284         .compat_ioctl   = dasd_ioctl,
3285         .getgeo         = dasd_getgeo,
3286 };
3287
3288 /*******************************************************************************
3289  * end of block device operations
3290  */
3291
3292 static void
3293 dasd_exit(void)
3294 {
3295 #ifdef CONFIG_PROC_FS
3296         dasd_proc_exit();
3297 #endif
3298         dasd_eer_exit();
3299         kmem_cache_destroy(dasd_page_cache);
3300         dasd_page_cache = NULL;
3301         dasd_gendisk_exit();
3302         dasd_devmap_exit();
3303         if (dasd_debug_area != NULL) {
3304                 debug_unregister(dasd_debug_area);
3305                 dasd_debug_area = NULL;
3306         }
3307         dasd_statistics_removeroot();
3308 }
3309
3310 /*
3311  * SECTION: common functions for ccw_driver use
3312  */
3313
3314 /*
3315  * Is the device read-only?
3316  * Note that this function does not report the setting of the
3317  * readonly device attribute, but how it is configured in z/VM.
3318  */
3319 int dasd_device_is_ro(struct dasd_device *device)
3320 {
3321         struct ccw_dev_id dev_id;
3322         struct diag210 diag_data;
3323         int rc;
3324
3325         if (!MACHINE_IS_VM)
3326                 return 0;
3327         ccw_device_get_id(device->cdev, &dev_id);
3328         memset(&diag_data, 0, sizeof(diag_data));
3329         diag_data.vrdcdvno = dev_id.devno;
3330         diag_data.vrdclen = sizeof(diag_data);
3331         rc = diag210(&diag_data);
3332         if (rc == 0 || rc == 2) {
3333                 return diag_data.vrdcvfla & 0x80;
3334         } else {
3335                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3336                           dev_id.devno, rc);
3337                 return 0;
3338         }
3339 }
3340 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3341
3342 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3343 {
3344         struct ccw_device *cdev = data;
3345         int ret;
3346
3347         ret = ccw_device_set_online(cdev);
3348         if (ret)
3349                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3350                         dev_name(&cdev->dev), ret);
3351 }
3352
3353 /*
3354  * Initial attempt at a probe function. this can be simplified once
3355  * the other detection code is gone.
3356  */
3357 int dasd_generic_probe(struct ccw_device *cdev,
3358                        struct dasd_discipline *discipline)
3359 {
3360         int ret;
3361
3362         ret = dasd_add_sysfs_files(cdev);
3363         if (ret) {
3364                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3365                                 "dasd_generic_probe: could not add "
3366                                 "sysfs entries");
3367                 return ret;
3368         }
3369         cdev->handler = &dasd_int_handler;
3370
3371         /*
3372          * Automatically online either all dasd devices (dasd_autodetect)
3373          * or all devices specified with dasd= parameters during
3374          * initial probe.
3375          */
3376         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3377             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3378                 async_schedule(dasd_generic_auto_online, cdev);
3379         return 0;
3380 }
3381 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3382
3383 void dasd_generic_free_discipline(struct dasd_device *device)
3384 {
3385         /* Forget the discipline information. */
3386         if (device->discipline) {
3387                 if (device->discipline->uncheck_device)
3388                         device->discipline->uncheck_device(device);
3389                 module_put(device->discipline->owner);
3390                 device->discipline = NULL;
3391         }
3392         if (device->base_discipline) {
3393                 module_put(device->base_discipline->owner);
3394                 device->base_discipline = NULL;
3395         }
3396 }
3397 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3398
3399 /*
3400  * This will one day be called from a global not_oper handler.
3401  * It is also used by driver_unregister during module unload.
3402  */
3403 void dasd_generic_remove(struct ccw_device *cdev)
3404 {
3405         struct dasd_device *device;
3406         struct dasd_block *block;
3407
3408         cdev->handler = NULL;
3409
3410         device = dasd_device_from_cdev(cdev);
3411         if (IS_ERR(device)) {
3412                 dasd_remove_sysfs_files(cdev);
3413                 return;
3414         }
3415         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3416             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3417                 /* Already doing offline processing */
3418                 dasd_put_device(device);
3419                 dasd_remove_sysfs_files(cdev);
3420                 return;
3421         }
3422         /*
3423          * This device is removed unconditionally. Set offline
3424          * flag to prevent dasd_open from opening it while it is
3425          * no quite down yet.
3426          */
3427         dasd_set_target_state(device, DASD_STATE_NEW);
3428         /* dasd_delete_device destroys the device reference. */
3429         block = device->block;
3430         dasd_delete_device(device);
3431         /*
3432          * life cycle of block is bound to device, so delete it after
3433          * device was safely removed
3434          */
3435         if (block)
3436                 dasd_free_block(block);
3437
3438         dasd_remove_sysfs_files(cdev);
3439 }
3440 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3441
3442 /*
3443  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3444  * the device is detected for the first time and is supposed to be used
3445  * or the user has started activation through sysfs.
3446  */
3447 int dasd_generic_set_online(struct ccw_device *cdev,
3448                             struct dasd_discipline *base_discipline)
3449 {
3450         struct dasd_discipline *discipline;
3451         struct dasd_device *device;
3452         int rc;
3453
3454         /* first online clears initial online feature flag */
3455         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3456         device = dasd_create_device(cdev);
3457         if (IS_ERR(device))
3458                 return PTR_ERR(device);
3459
3460         discipline = base_discipline;
3461         if (device->features & DASD_FEATURE_USEDIAG) {
3462                 if (!dasd_diag_discipline_pointer) {
3463                         /* Try to load the required module. */
3464                         rc = request_module(DASD_DIAG_MOD);
3465                         if (rc) {
3466                                 pr_warn("%s Setting the DASD online failed "
3467                                         "because the required module %s "
3468                                         "could not be loaded (rc=%d)\n",
3469                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3470                                         rc);
3471                                 dasd_delete_device(device);
3472                                 return -ENODEV;
3473                         }
3474                 }
3475                 /* Module init could have failed, so check again here after
3476                  * request_module(). */
3477                 if (!dasd_diag_discipline_pointer) {
3478                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3479                                 dev_name(&cdev->dev));
3480                         dasd_delete_device(device);
3481                         return -ENODEV;
3482                 }
3483                 discipline = dasd_diag_discipline_pointer;
3484         }
3485         if (!try_module_get(base_discipline->owner)) {
3486                 dasd_delete_device(device);
3487                 return -EINVAL;
3488         }
3489         if (!try_module_get(discipline->owner)) {
3490                 module_put(base_discipline->owner);
3491                 dasd_delete_device(device);
3492                 return -EINVAL;
3493         }
3494         device->base_discipline = base_discipline;
3495         device->discipline = discipline;
3496
3497         /* check_device will allocate block device if necessary */
3498         rc = discipline->check_device(device);
3499         if (rc) {
3500                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3501                         dev_name(&cdev->dev), discipline->name, rc);
3502                 module_put(discipline->owner);
3503                 module_put(base_discipline->owner);
3504                 dasd_delete_device(device);
3505                 return rc;
3506         }
3507
3508         dasd_set_target_state(device, DASD_STATE_ONLINE);
3509         if (device->state <= DASD_STATE_KNOWN) {
3510                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3511                         dev_name(&cdev->dev));
3512                 rc = -ENODEV;
3513                 dasd_set_target_state(device, DASD_STATE_NEW);
3514                 if (device->block)
3515                         dasd_free_block(device->block);
3516                 dasd_delete_device(device);
3517         } else
3518                 pr_debug("dasd_generic device %s found\n",
3519                                 dev_name(&cdev->dev));
3520
3521         wait_event(dasd_init_waitq, _wait_for_device(device));
3522
3523         dasd_put_device(device);
3524         return rc;
3525 }
3526 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3527
3528 int dasd_generic_set_offline(struct ccw_device *cdev)
3529 {
3530         struct dasd_device *device;
3531         struct dasd_block *block;
3532         int max_count, open_count, rc;
3533         unsigned long flags;
3534
3535         rc = 0;
3536         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3537         device = dasd_device_from_cdev_locked(cdev);
3538         if (IS_ERR(device)) {
3539                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3540                 return PTR_ERR(device);
3541         }
3542
3543         /*
3544          * We must make sure that this device is currently not in use.
3545          * The open_count is increased for every opener, that includes
3546          * the blkdev_get in dasd_scan_partitions. We are only interested
3547          * in the other openers.
3548          */
3549         if (device->block) {
3550                 max_count = device->block->bdev ? 0 : -1;
3551                 open_count = atomic_read(&device->block->open_count);
3552                 if (open_count > max_count) {
3553                         if (open_count > 0)
3554                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3555                                         dev_name(&cdev->dev), open_count);
3556                         else
3557                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3558                                         dev_name(&cdev->dev));
3559                         rc = -EBUSY;
3560                         goto out_err;
3561                 }
3562         }
3563
3564         /*
3565          * Test if the offline processing is already running and exit if so.
3566          * If a safe offline is being processed this could only be a normal
3567          * offline that should be able to overtake the safe offline and
3568          * cancel any I/O we do not want to wait for any longer
3569          */
3570         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3571                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3572                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3573                                   &device->flags);
3574                 } else {
3575                         rc = -EBUSY;
3576                         goto out_err;
3577                 }
3578         }
3579         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3580
3581         /*
3582          * if safe_offline is called set safe_offline_running flag and
3583          * clear safe_offline so that a call to normal offline
3584          * can overrun safe_offline processing
3585          */
3586         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3587             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3588                 /* need to unlock here to wait for outstanding I/O */
3589                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3590                 /*
3591                  * If we want to set the device safe offline all IO operations
3592                  * should be finished before continuing the offline process
3593                  * so sync bdev first and then wait for our queues to become
3594                  * empty
3595                  */
3596                 if (device->block) {
3597                         rc = fsync_bdev(device->block->bdev);
3598                         if (rc != 0)
3599                                 goto interrupted;
3600                 }
3601                 dasd_schedule_device_bh(device);
3602                 rc = wait_event_interruptible(shutdown_waitq,
3603                                               _wait_for_empty_queues(device));
3604                 if (rc != 0)
3605                         goto interrupted;
3606
3607                 /*
3608                  * check if a normal offline process overtook the offline
3609                  * processing in this case simply do nothing beside returning
3610                  * that we got interrupted
3611                  * otherwise mark safe offline as not running any longer and
3612                  * continue with normal offline
3613                  */
3614                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3615                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3616                         rc = -ERESTARTSYS;
3617                         goto out_err;
3618                 }
3619                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3620         }
3621         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3622
3623         dasd_set_target_state(device, DASD_STATE_NEW);
3624         /* dasd_delete_device destroys the device reference. */
3625         block = device->block;
3626         dasd_delete_device(device);
3627         /*
3628          * life cycle of block is bound to device, so delete it after
3629          * device was safely removed
3630          */
3631         if (block)
3632                 dasd_free_block(block);
3633
3634         return 0;
3635
3636 interrupted:
3637         /* interrupted by signal */
3638         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3639         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3640         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3641 out_err:
3642         dasd_put_device(device);
3643         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3644         return rc;
3645 }
3646 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3647
3648 int dasd_generic_last_path_gone(struct dasd_device *device)
3649 {
3650         struct dasd_ccw_req *cqr;
3651
3652         dev_warn(&device->cdev->dev, "No operational channel path is left "
3653                  "for the device\n");
3654         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3655         /* First of all call extended error reporting. */
3656         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3657
3658         if (device->state < DASD_STATE_BASIC)
3659                 return 0;
3660         /* Device is active. We want to keep it. */
3661         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3662                 if ((cqr->status == DASD_CQR_IN_IO) ||
3663                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3664                         cqr->status = DASD_CQR_QUEUED;
3665                         cqr->retries++;
3666                 }
3667         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3668         dasd_device_clear_timer(device);
3669         dasd_schedule_device_bh(device);
3670         return 1;
3671 }
3672 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3673
3674 int dasd_generic_path_operational(struct dasd_device *device)
3675 {
3676         dev_info(&device->cdev->dev, "A channel path to the device has become "
3677                  "operational\n");
3678         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3679         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3680         if (device->stopped & DASD_UNRESUMED_PM) {
3681                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3682                 dasd_restore_device(device);
3683                 return 1;
3684         }
3685         dasd_schedule_device_bh(device);
3686         if (device->block) {
3687                 dasd_schedule_block_bh(device->block);
3688                 if (device->block->request_queue)
3689                         blk_mq_run_hw_queues(device->block->request_queue,
3690                                              true);
3691                 }
3692
3693         if (!device->stopped)
3694                 wake_up(&generic_waitq);
3695
3696         return 1;
3697 }
3698 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3699
3700 int dasd_generic_notify(struct ccw_device *cdev, int event)
3701 {
3702         struct dasd_device *device;
3703         int ret;
3704
3705         device = dasd_device_from_cdev_locked(cdev);
3706         if (IS_ERR(device))
3707                 return 0;
3708         ret = 0;
3709         switch (event) {
3710         case CIO_GONE:
3711         case CIO_BOXED:
3712         case CIO_NO_PATH:
3713                 dasd_path_no_path(device);
3714                 ret = dasd_generic_last_path_gone(device);
3715                 break;
3716         case CIO_OPER:
3717                 ret = 1;
3718                 if (dasd_path_get_opm(device))
3719                         ret = dasd_generic_path_operational(device);
3720                 break;
3721         }
3722         dasd_put_device(device);
3723         return ret;
3724 }
3725 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3726
3727 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3728 {
3729         struct dasd_device *device;
3730         int chp, oldopm, hpfpm, ifccpm;
3731
3732         device = dasd_device_from_cdev_locked(cdev);
3733         if (IS_ERR(device))
3734                 return;
3735
3736         oldopm = dasd_path_get_opm(device);
3737         for (chp = 0; chp < 8; chp++) {
3738                 if (path_event[chp] & PE_PATH_GONE) {
3739                         dasd_path_notoper(device, chp);
3740                 }
3741                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3742                         dasd_path_available(device, chp);
3743                         dasd_schedule_device_bh(device);
3744                 }
3745                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3746                         if (!dasd_path_is_operational(device, chp) &&
3747                             !dasd_path_need_verify(device, chp)) {
3748                                 /*
3749                                  * we can not establish a pathgroup on an
3750                                  * unavailable path, so trigger a path
3751                                  * verification first
3752                                  */
3753                         dasd_path_available(device, chp);
3754                         dasd_schedule_device_bh(device);
3755                         }
3756                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3757                                       "Pathgroup re-established\n");
3758                         if (device->discipline->kick_validate)
3759                                 device->discipline->kick_validate(device);
3760                 }
3761         }
3762         hpfpm = dasd_path_get_hpfpm(device);
3763         ifccpm = dasd_path_get_ifccpm(device);
3764         if (!dasd_path_get_opm(device) && hpfpm) {
3765                 /*
3766                  * device has no operational paths but at least one path is
3767                  * disabled due to HPF errors
3768                  * disable HPF at all and use the path(s) again
3769                  */
3770                 if (device->discipline->disable_hpf)
3771                         device->discipline->disable_hpf(device);
3772                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3773                 dasd_path_set_tbvpm(device, hpfpm);
3774                 dasd_schedule_device_bh(device);
3775                 dasd_schedule_requeue(device);
3776         } else if (!dasd_path_get_opm(device) && ifccpm) {
3777                 /*
3778                  * device has no operational paths but at least one path is
3779                  * disabled due to IFCC errors
3780                  * trigger path verification on paths with IFCC errors
3781                  */
3782                 dasd_path_set_tbvpm(device, ifccpm);
3783                 dasd_schedule_device_bh(device);
3784         }
3785         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3786                 dev_warn(&device->cdev->dev,
3787                          "No verified channel paths remain for the device\n");
3788                 DBF_DEV_EVENT(DBF_WARNING, device,
3789                               "%s", "last verified path gone");
3790                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3791                 dasd_device_set_stop_bits(device,
3792                                           DASD_STOPPED_DC_WAIT);
3793         }
3794         dasd_put_device(device);
3795 }
3796 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3797
3798 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3799 {
3800         if (!dasd_path_get_opm(device) && lpm) {
3801                 dasd_path_set_opm(device, lpm);
3802                 dasd_generic_path_operational(device);
3803         } else
3804                 dasd_path_add_opm(device, lpm);
3805         return 0;
3806 }
3807 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3808
3809 /*
3810  * clear active requests and requeue them to block layer if possible
3811  */
3812 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3813 {
3814         struct list_head requeue_queue;
3815         struct dasd_ccw_req *cqr, *n;
3816         struct dasd_ccw_req *refers;
3817         int rc;
3818
3819         INIT_LIST_HEAD(&requeue_queue);
3820         spin_lock_irq(get_ccwdev_lock(device->cdev));
3821         rc = 0;
3822         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3823                 /* Check status and move request to flush_queue */
3824                 if (cqr->status == DASD_CQR_IN_IO) {
3825                         rc = device->discipline->term_IO(cqr);
3826                         if (rc) {
3827                                 /* unable to terminate requeust */
3828                                 dev_err(&device->cdev->dev,
3829                                         "Unable to terminate request %p "
3830                                         "on suspend\n", cqr);
3831                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3832                                 dasd_put_device(device);
3833                                 return rc;
3834                         }
3835                 }
3836                 list_move_tail(&cqr->devlist, &requeue_queue);
3837         }
3838         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3839
3840         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3841                 wait_event(dasd_flush_wq,
3842                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3843
3844                 /*
3845                  * requeue requests to blocklayer will only work
3846                  * for block device requests
3847                  */
3848                 if (_dasd_requeue_request(cqr))
3849                         continue;
3850
3851                 /* remove requests from device and block queue */
3852                 list_del_init(&cqr->devlist);
3853                 while (cqr->refers != NULL) {
3854                         refers = cqr->refers;
3855                         /* remove the request from the block queue */
3856                         list_del(&cqr->blocklist);
3857                         /* free the finished erp request */
3858                         dasd_free_erp_request(cqr, cqr->memdev);
3859                         cqr = refers;
3860                 }
3861
3862                 /*
3863                  * _dasd_requeue_request already checked for a valid
3864                  * blockdevice, no need to check again
3865                  * all erp requests (cqr->refers) have a cqr->block
3866                  * pointer copy from the original cqr
3867                  */
3868                 list_del_init(&cqr->blocklist);
3869                 cqr->block->base->discipline->free_cp(
3870                         cqr, (struct request *) cqr->callback_data);
3871         }
3872
3873         /*
3874          * if requests remain then they are internal request
3875          * and go back to the device queue
3876          */
3877         if (!list_empty(&requeue_queue)) {
3878                 /* move freeze_queue to start of the ccw_queue */
3879                 spin_lock_irq(get_ccwdev_lock(device->cdev));
3880                 list_splice_tail(&requeue_queue, &device->ccw_queue);
3881                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3882         }
3883         dasd_schedule_device_bh(device);
3884         return rc;
3885 }
3886
3887 static void do_requeue_requests(struct work_struct *work)
3888 {
3889         struct dasd_device *device = container_of(work, struct dasd_device,
3890                                                   requeue_requests);
3891         dasd_generic_requeue_all_requests(device);
3892         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3893         if (device->block)
3894                 dasd_schedule_block_bh(device->block);
3895         dasd_put_device(device);
3896 }
3897
3898 void dasd_schedule_requeue(struct dasd_device *device)
3899 {
3900         dasd_get_device(device);
3901         /* queue call to dasd_reload_device to the kernel event daemon. */
3902         if (!schedule_work(&device->requeue_requests))
3903                 dasd_put_device(device);
3904 }
3905 EXPORT_SYMBOL(dasd_schedule_requeue);
3906
3907 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3908 {
3909         struct dasd_device *device = dasd_device_from_cdev(cdev);
3910
3911         if (IS_ERR(device))
3912                 return PTR_ERR(device);
3913
3914         /* mark device as suspended */
3915         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3916
3917         if (device->discipline->freeze)
3918                 device->discipline->freeze(device);
3919
3920         /* disallow new I/O  */
3921         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3922
3923         return dasd_generic_requeue_all_requests(device);
3924 }
3925 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3926
3927 int dasd_generic_restore_device(struct ccw_device *cdev)
3928 {
3929         struct dasd_device *device = dasd_device_from_cdev(cdev);
3930         int rc = 0;
3931
3932         if (IS_ERR(device))
3933                 return PTR_ERR(device);
3934
3935         /* allow new IO again */
3936         dasd_device_remove_stop_bits(device,
3937                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3938
3939         dasd_schedule_device_bh(device);
3940
3941         /*
3942          * call discipline restore function
3943          * if device is stopped do nothing e.g. for disconnected devices
3944          */
3945         if (device->discipline->restore && !(device->stopped))
3946                 rc = device->discipline->restore(device);
3947         if (rc || device->stopped)
3948                 /*
3949                  * if the resume failed for the DASD we put it in
3950                  * an UNRESUMED stop state
3951                  */
3952                 device->stopped |= DASD_UNRESUMED_PM;
3953
3954         if (device->block) {
3955                 dasd_schedule_block_bh(device->block);
3956                 if (device->block->request_queue)
3957                         blk_mq_run_hw_queues(device->block->request_queue,
3958                                              true);
3959         }
3960
3961         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3962         dasd_put_device(device);
3963         return 0;
3964 }
3965 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3966
3967 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3968                                                    void *rdc_buffer,
3969                                                    int rdc_buffer_size,
3970                                                    int magic)
3971 {
3972         struct dasd_ccw_req *cqr;
3973         struct ccw1 *ccw;
3974         unsigned long *idaw;
3975
3976         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
3977                                    NULL);
3978
3979         if (IS_ERR(cqr)) {
3980                 /* internal error 13 - Allocating the RDC request failed*/
3981                 dev_err(&device->cdev->dev,
3982                          "An error occurred in the DASD device driver, "
3983                          "reason=%s\n", "13");
3984                 return cqr;
3985         }
3986
3987         ccw = cqr->cpaddr;
3988         ccw->cmd_code = CCW_CMD_RDC;
3989         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3990                 idaw = (unsigned long *) (cqr->data);
3991                 ccw->cda = (__u32)(addr_t) idaw;
3992                 ccw->flags = CCW_FLAG_IDA;
3993                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3994         } else {
3995                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3996                 ccw->flags = 0;
3997         }
3998
3999         ccw->count = rdc_buffer_size;
4000         cqr->startdev = device;
4001         cqr->memdev = device;
4002         cqr->expires = 10*HZ;
4003         cqr->retries = 256;
4004         cqr->buildclk = get_tod_clock();
4005         cqr->status = DASD_CQR_FILLED;
4006         return cqr;
4007 }
4008
4009
4010 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4011                                 void *rdc_buffer, int rdc_buffer_size)
4012 {
4013         int ret;
4014         struct dasd_ccw_req *cqr;
4015
4016         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
4017                                      magic);
4018         if (IS_ERR(cqr))
4019                 return PTR_ERR(cqr);
4020
4021         ret = dasd_sleep_on(cqr);
4022         dasd_sfree_request(cqr, cqr->memdev);
4023         return ret;
4024 }
4025 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4026
4027 /*
4028  *   In command mode and transport mode we need to look for sense
4029  *   data in different places. The sense data itself is allways
4030  *   an array of 32 bytes, so we can unify the sense data access
4031  *   for both modes.
4032  */
4033 char *dasd_get_sense(struct irb *irb)
4034 {
4035         struct tsb *tsb = NULL;
4036         char *sense = NULL;
4037
4038         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4039                 if (irb->scsw.tm.tcw)
4040                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4041                                           irb->scsw.tm.tcw);
4042                 if (tsb && tsb->length == 64 && tsb->flags)
4043                         switch (tsb->flags & 0x07) {
4044                         case 1: /* tsa_iostat */
4045                                 sense = tsb->tsa.iostat.sense;
4046                                 break;
4047                         case 2: /* tsa_ddpc */
4048                                 sense = tsb->tsa.ddpc.sense;
4049                                 break;
4050                         default:
4051                                 /* currently we don't use interrogate data */
4052                                 break;
4053                         }
4054         } else if (irb->esw.esw0.erw.cons) {
4055                 sense = irb->ecw;
4056         }
4057         return sense;
4058 }
4059 EXPORT_SYMBOL_GPL(dasd_get_sense);
4060
4061 void dasd_generic_shutdown(struct ccw_device *cdev)
4062 {
4063         struct dasd_device *device;
4064
4065         device = dasd_device_from_cdev(cdev);
4066         if (IS_ERR(device))
4067                 return;
4068
4069         if (device->block)
4070                 dasd_schedule_block_bh(device->block);
4071
4072         dasd_schedule_device_bh(device);
4073
4074         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4075 }
4076 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4077
4078 static int __init dasd_init(void)
4079 {
4080         int rc;
4081
4082         init_waitqueue_head(&dasd_init_waitq);
4083         init_waitqueue_head(&dasd_flush_wq);
4084         init_waitqueue_head(&generic_waitq);
4085         init_waitqueue_head(&shutdown_waitq);
4086
4087         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4088         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4089         if (dasd_debug_area == NULL) {
4090                 rc = -ENOMEM;
4091                 goto failed;
4092         }
4093         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4094         debug_set_level(dasd_debug_area, DBF_WARNING);
4095
4096         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4097
4098         dasd_diag_discipline_pointer = NULL;
4099
4100         dasd_statistics_createroot();
4101
4102         rc = dasd_devmap_init();
4103         if (rc)
4104                 goto failed;
4105         rc = dasd_gendisk_init();
4106         if (rc)
4107                 goto failed;
4108         rc = dasd_parse();
4109         if (rc)
4110                 goto failed;
4111         rc = dasd_eer_init();
4112         if (rc)
4113                 goto failed;
4114 #ifdef CONFIG_PROC_FS
4115         rc = dasd_proc_init();
4116         if (rc)
4117                 goto failed;
4118 #endif
4119
4120         return 0;
4121 failed:
4122         pr_info("The DASD device driver could not be initialized\n");
4123         dasd_exit();
4124         return rc;
4125 }
4126
4127 module_init(dasd_init);
4128 module_exit(dasd_exit);