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_free_queue(struct dasd_block *);
  74 static int dasd_flush_block_queue(struct dasd_block *);
  75 static void dasd_device_tasklet(unsigned long);
  76 static void dasd_block_tasklet(unsigned long);
  77 static void do_kick_device(struct work_struct *);
  78 static void do_restore_device(struct work_struct *);
  79 static void do_reload_device(struct work_struct *);
  80 static void do_requeue_requests(struct work_struct *);
  81 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  82 static void dasd_device_timeout(struct timer_list *);
  83 static void dasd_block_timeout(struct timer_list *);
  84 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  85 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  86 static void dasd_profile_exit(struct dasd_profile *);
  87 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  88 static void dasd_hosts_exit(struct dasd_device *);
  89
  90 /*
  91  * SECTION: Operations on the device structure.
  92  */
  93 static wait_queue_head_t dasd_init_waitq;
  94 static wait_queue_head_t dasd_flush_wq;
  95 static wait_queue_head_t generic_waitq;
  96 static wait_queue_head_t shutdown_waitq;
  97
  98 /*
  99  * Allocate memory for a new device structure.
 100  */
 101 struct dasd_device *dasd_alloc_device(void)
 102 {
 103         struct dasd_device *device;
 104
 105         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
 106         if (!device)
 107                 return ERR_PTR(-ENOMEM);
 108
 109         /* Get two pages for normal block device operations. */
 110         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 111         if (!device->ccw_mem) {
 112                 kfree(device);
 113                 return ERR_PTR(-ENOMEM);
 114         }
 115         /* Get one page for error recovery. */
 116         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 117         if (!device->erp_mem) {
 118                 free_pages((unsigned long) device->ccw_mem, 1);
 119                 kfree(device);
 120                 return ERR_PTR(-ENOMEM);
 121         }
 122         /* Get two pages for ese format. */
 123         device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 124         if (!device->ese_mem) {
 125                 free_page((unsigned long) device->erp_mem);
 126                 free_pages((unsigned long) device->ccw_mem, 1);
 127                 kfree(device);
 128                 return ERR_PTR(-ENOMEM);
 129         }
 130
 131         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 132         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 133         dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 134         spin_lock_init(&device->mem_lock);
 135         atomic_set(&device->tasklet_scheduled, 0);
 136         tasklet_init(&device->tasklet, dasd_device_tasklet,
 137                      (unsigned long) device);
 138         INIT_LIST_HEAD(&device->ccw_queue);
 139         timer_setup(&device->timer, dasd_device_timeout, 0);
 140         INIT_WORK(&device->kick_work, do_kick_device);
 141         INIT_WORK(&device->restore_device, do_restore_device);
 142         INIT_WORK(&device->reload_device, do_reload_device);
 143         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 144         device->state = DASD_STATE_NEW;
 145         device->target = DASD_STATE_NEW;
 146         mutex_init(&device->state_mutex);
 147         spin_lock_init(&device->profile.lock);
 148         return device;
 149 }
 150
 151 /*
 152  * Free memory of a device structure.
 153  */
 154 void dasd_free_device(struct dasd_device *device)
 155 {
 156         kfree(device->private);
 157         free_pages((unsigned long) device->ese_mem, 1);
 158         free_page((unsigned long) device->erp_mem);
 159         free_pages((unsigned long) device->ccw_mem, 1);
 160         kfree(device);
 161 }
 162
 163 /*
 164  * Allocate memory for a new device structure.
 165  */
 166 struct dasd_block *dasd_alloc_block(void)
 167 {
 168         struct dasd_block *block;
 169
 170         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 171         if (!block)
 172                 return ERR_PTR(-ENOMEM);
 173         /* open_count = 0 means device online but not in use */
 174         atomic_set(&block->open_count, -1);
 175
 176         atomic_set(&block->tasklet_scheduled, 0);
 177         tasklet_init(&block->tasklet, dasd_block_tasklet,
 178                      (unsigned long) block);
 179         INIT_LIST_HEAD(&block->ccw_queue);
 180         spin_lock_init(&block->queue_lock);
 181         INIT_LIST_HEAD(&block->format_list);
 182         spin_lock_init(&block->format_lock);
 183         timer_setup(&block->timer, dasd_block_timeout, 0);
 184         spin_lock_init(&block->profile.lock);
 185
 186         return block;
 187 }
 188 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 189
 190 /*
 191  * Free memory of a device structure.
 192  */
 193 void dasd_free_block(struct dasd_block *block)
 194 {
 195         kfree(block);
 196 }
 197 EXPORT_SYMBOL_GPL(dasd_free_block);
 198
 199 /*
 200  * Make a new device known to the system.
 201  */
 202 static int dasd_state_new_to_known(struct dasd_device *device)
 203 {
 204         int rc;
 205
 206         /*
 207          * As long as the device is not in state DASD_STATE_NEW we want to
 208          * keep the reference count > 0.
 209          */
 210         dasd_get_device(device);
 211
 212         if (device->block) {
 213                 rc = dasd_alloc_queue(device->block);
 214                 if (rc) {
 215                         dasd_put_device(device);
 216                         return rc;
 217                 }
 218         }
 219         device->state = DASD_STATE_KNOWN;
 220         return 0;
 221 }
 222
 223 /*
 224  * Let the system forget about a device.
 225  */
 226 static int dasd_state_known_to_new(struct dasd_device *device)
 227 {
 228         /* Disable extended error reporting for this device. */
 229         dasd_eer_disable(device);
 230         device->state = DASD_STATE_NEW;
 231
 232         if (device->block)
 233                 dasd_free_queue(device->block);
 234
 235         /* Give up reference we took in dasd_state_new_to_known. */
 236         dasd_put_device(device);
 237         return 0;
 238 }
 239
 240 static struct dentry *dasd_debugfs_setup(const char *name,
 241                                          struct dentry *base_dentry)
 242 {
 243         struct dentry *pde;
 244
 245         if (!base_dentry)
 246                 return NULL;
 247         pde = debugfs_create_dir(name, base_dentry);
 248         if (!pde || IS_ERR(pde))
 249                 return NULL;
 250         return pde;
 251 }
 252
 253 /*
 254  * Request the irq line for the device.
 255  */
 256 static int dasd_state_known_to_basic(struct dasd_device *device)
 257 {
 258         struct dasd_block *block = device->block;
 259         int rc = 0;
 260
 261         /* Allocate and register gendisk structure. */
 262         if (block) {
 263                 rc = dasd_gendisk_alloc(block);
 264                 if (rc)
 265                         return rc;
 266                 block->debugfs_dentry =
 267                         dasd_debugfs_setup(block->gdp->disk_name,
 268                                            dasd_debugfs_root_entry);
 269                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 270                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 271                         dasd_profile_on(&device->block->profile);
 272         }
 273         device->debugfs_dentry =
 274                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 275                                    dasd_debugfs_root_entry);
 276         dasd_profile_init(&device->profile, device->debugfs_dentry);
 277         dasd_hosts_init(device->debugfs_dentry, device);
 278
 279         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 280         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 281                                             8 * sizeof(long));
 282         debug_register_view(device->debug_area, &debug_sprintf_view);
 283         debug_set_level(device->debug_area, DBF_WARNING);
 284         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 285
 286         device->state = DASD_STATE_BASIC;
 287
 288         return rc;
 289 }
 290
 291 /*
 292  * Release the irq line for the device. Terminate any running i/o.
 293  */
 294 static int dasd_state_basic_to_known(struct dasd_device *device)
 295 {
 296         int rc;
 297
 298         if (device->discipline->basic_to_known) {
 299                 rc = device->discipline->basic_to_known(device);
 300                 if (rc)
 301                         return rc;
 302         }
 303
 304         if (device->block) {
 305                 dasd_profile_exit(&device->block->profile);
 306                 debugfs_remove(device->block->debugfs_dentry);
 307                 dasd_gendisk_free(device->block);
 308                 dasd_block_clear_timer(device->block);
 309         }
 310         rc = dasd_flush_device_queue(device);
 311         if (rc)
 312                 return rc;
 313         dasd_device_clear_timer(device);
 314         dasd_profile_exit(&device->profile);
 315         dasd_hosts_exit(device);
 316         debugfs_remove(device->debugfs_dentry);
 317         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 318         if (device->debug_area != NULL) {
 319                 debug_unregister(device->debug_area);
 320                 device->debug_area = NULL;
 321         }
 322         device->state = DASD_STATE_KNOWN;
 323         return 0;
 324 }
 325
 326 /*
 327  * Do the initial analysis. The do_analysis function may return
 328  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 329  * until the discipline decides to continue the startup sequence
 330  * by calling the function dasd_change_state. The eckd disciplines
 331  * uses this to start a ccw that detects the format. The completion
 332  * interrupt for this detection ccw uses the kernel event daemon to
 333  * trigger the call to dasd_change_state. All this is done in the
 334  * discipline code, see dasd_eckd.c.
 335  * After the analysis ccw is done (do_analysis returned 0) the block
 336  * device is setup.
 337  * In case the analysis returns an error, the device setup is stopped
 338  * (a fake disk was already added to allow formatting).
 339  */
 340 static int dasd_state_basic_to_ready(struct dasd_device *device)
 341 {
 342         int rc;
 343         struct dasd_block *block;
 344         struct gendisk *disk;
 345
 346         rc = 0;
 347         block = device->block;
 348         /* make disk known with correct capacity */
 349         if (block) {
 350                 if (block->base->discipline->do_analysis != NULL)
 351                         rc = block->base->discipline->do_analysis(block);
 352                 if (rc) {
 353                         if (rc != -EAGAIN) {
 354                                 device->state = DASD_STATE_UNFMT;
 355                                 disk = device->block->gdp;
 356                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 357                                                KOBJ_CHANGE);
 358                                 goto out;
 359                         }
 360                         return rc;
 361                 }
 362                 if (device->discipline->setup_blk_queue)
 363                         device->discipline->setup_blk_queue(block);
 364                 set_capacity(block->gdp,
 365                              block->blocks << block->s2b_shift);
 366                 device->state = DASD_STATE_READY;
 367                 rc = dasd_scan_partitions(block);
 368                 if (rc) {
 369                         device->state = DASD_STATE_BASIC;
 370                         return rc;
 371                 }
 372         } else {
 373                 device->state = DASD_STATE_READY;
 374         }
 375 out:
 376         if (device->discipline->basic_to_ready)
 377                 rc = device->discipline->basic_to_ready(device);
 378         return rc;
 379 }
 380
 381 static inline
 382 int _wait_for_empty_queues(struct dasd_device *device)
 383 {
 384         if (device->block)
 385                 return list_empty(&device->ccw_queue) &&
 386                         list_empty(&device->block->ccw_queue);
 387         else
 388                 return list_empty(&device->ccw_queue);
 389 }
 390
 391 /*
 392  * Remove device from block device layer. Destroy dirty buffers.
 393  * Forget format information. Check if the target level is basic
 394  * and if it is create fake disk for formatting.
 395  */
 396 static int dasd_state_ready_to_basic(struct dasd_device *device)
 397 {
 398         int rc;
 399
 400         device->state = DASD_STATE_BASIC;
 401         if (device->block) {
 402                 struct dasd_block *block = device->block;
 403                 rc = dasd_flush_block_queue(block);
 404                 if (rc) {
 405                         device->state = DASD_STATE_READY;
 406                         return rc;
 407                 }
 408                 dasd_destroy_partitions(block);
 409                 block->blocks = 0;
 410                 block->bp_block = 0;
 411                 block->s2b_shift = 0;
 412         }
 413         return 0;
 414 }
 415
 416 /*
 417  * Back to basic.
 418  */
 419 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 420 {
 421         device->state = DASD_STATE_BASIC;
 422         return 0;
 423 }
 424
 425 /*
 426  * Make the device online and schedule the bottom half to start
 427  * the requeueing of requests from the linux request queue to the
 428  * ccw queue.
 429  */
 430 static int
 431 dasd_state_ready_to_online(struct dasd_device * device)
 432 {
 433         struct gendisk *disk;
 434         struct disk_part_iter piter;
 435         struct hd_struct *part;
 436
 437         device->state = DASD_STATE_ONLINE;
 438         if (device->block) {
 439                 dasd_schedule_block_bh(device->block);
 440                 if ((device->features & DASD_FEATURE_USERAW)) {
 441                         disk = device->block->gdp;
 442                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 443                         return 0;
 444                 }
 445                 disk = device->block->bdev->bd_disk;
 446                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 447                 while ((part = disk_part_iter_next(&piter)))
 448                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 449                 disk_part_iter_exit(&piter);
 450         }
 451         return 0;
 452 }
 453
 454 /*
 455  * Stop the requeueing of requests again.
 456  */
 457 static int dasd_state_online_to_ready(struct dasd_device *device)
 458 {
 459         int rc;
 460         struct gendisk *disk;
 461         struct disk_part_iter piter;
 462         struct hd_struct *part;
 463
 464         if (device->discipline->online_to_ready) {
 465                 rc = device->discipline->online_to_ready(device);
 466                 if (rc)
 467                         return rc;
 468         }
 469
 470         device->state = DASD_STATE_READY;
 471         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 472                 disk = device->block->bdev->bd_disk;
 473                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 474                 while ((part = disk_part_iter_next(&piter)))
 475                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 476                 disk_part_iter_exit(&piter);
 477         }
 478         return 0;
 479 }
 480
 481 /*
 482  * Device startup state changes.
 483  */
 484 static int dasd_increase_state(struct dasd_device *device)
 485 {
 486         int rc;
 487
 488         rc = 0;
 489         if (device->state == DASD_STATE_NEW &&
 490             device->target >= DASD_STATE_KNOWN)
 491                 rc = dasd_state_new_to_known(device);
 492
 493         if (!rc &&
 494             device->state == DASD_STATE_KNOWN &&
 495             device->target >= DASD_STATE_BASIC)
 496                 rc = dasd_state_known_to_basic(device);
 497
 498         if (!rc &&
 499             device->state == DASD_STATE_BASIC &&
 500             device->target >= DASD_STATE_READY)
 501                 rc = dasd_state_basic_to_ready(device);
 502
 503         if (!rc &&
 504             device->state == DASD_STATE_UNFMT &&
 505             device->target > DASD_STATE_UNFMT)
 506                 rc = -EPERM;
 507
 508         if (!rc &&
 509             device->state == DASD_STATE_READY &&
 510             device->target >= DASD_STATE_ONLINE)
 511                 rc = dasd_state_ready_to_online(device);
 512
 513         return rc;
 514 }
 515
 516 /*
 517  * Device shutdown state changes.
 518  */
 519 static int dasd_decrease_state(struct dasd_device *device)
 520 {
 521         int rc;
 522
 523         rc = 0;
 524         if (device->state == DASD_STATE_ONLINE &&
 525             device->target <= DASD_STATE_READY)
 526                 rc = dasd_state_online_to_ready(device);
 527
 528         if (!rc &&
 529             device->state == DASD_STATE_READY &&
 530             device->target <= DASD_STATE_BASIC)
 531                 rc = dasd_state_ready_to_basic(device);
 532
 533         if (!rc &&
 534             device->state == DASD_STATE_UNFMT &&
 535             device->target <= DASD_STATE_BASIC)
 536                 rc = dasd_state_unfmt_to_basic(device);
 537
 538         if (!rc &&
 539             device->state == DASD_STATE_BASIC &&
 540             device->target <= DASD_STATE_KNOWN)
 541                 rc = dasd_state_basic_to_known(device);
 542
 543         if (!rc &&
 544             device->state == DASD_STATE_KNOWN &&
 545             device->target <= DASD_STATE_NEW)
 546                 rc = dasd_state_known_to_new(device);
 547
 548         return rc;
 549 }
 550
 551 /*
 552  * This is the main startup/shutdown routine.
 553  */
 554 static void dasd_change_state(struct dasd_device *device)
 555 {
 556         int rc;
 557
 558         if (device->state == device->target)
 559                 /* Already where we want to go today... */
 560                 return;
 561         if (device->state < device->target)
 562                 rc = dasd_increase_state(device);
 563         else
 564                 rc = dasd_decrease_state(device);
 565         if (rc == -EAGAIN)
 566                 return;
 567         if (rc)
 568                 device->target = device->state;
 569
 570         /* let user-space know that the device status changed */
 571         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 572
 573         if (device->state == device->target)
 574                 wake_up(&dasd_init_waitq);
 575 }
 576
 577 /*
 578  * Kick starter for devices that did not complete the startup/shutdown
 579  * procedure or were sleeping because of a pending state.
 580  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 581  * event daemon.
 582  */
 583 static void do_kick_device(struct work_struct *work)
 584 {
 585         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 586         mutex_lock(&device->state_mutex);
 587         dasd_change_state(device);
 588         mutex_unlock(&device->state_mutex);
 589         dasd_schedule_device_bh(device);
 590         dasd_put_device(device);
 591 }
 592
 593 void dasd_kick_device(struct dasd_device *device)
 594 {
 595         dasd_get_device(device);
 596         /* queue call to dasd_kick_device to the kernel event daemon. */
 597         if (!schedule_work(&device->kick_work))
 598                 dasd_put_device(device);
 599 }
 600 EXPORT_SYMBOL(dasd_kick_device);
 601
 602 /*
 603  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 604  * event daemon.
 605  */
 606 static void do_reload_device(struct work_struct *work)
 607 {
 608         struct dasd_device *device = container_of(work, struct dasd_device,
 609                                                   reload_device);
 610         device->discipline->reload(device);
 611         dasd_put_device(device);
 612 }
 613
 614 void dasd_reload_device(struct dasd_device *device)
 615 {
 616         dasd_get_device(device);
 617         /* queue call to dasd_reload_device to the kernel event daemon. */
 618         if (!schedule_work(&device->reload_device))
 619                 dasd_put_device(device);
 620 }
 621 EXPORT_SYMBOL(dasd_reload_device);
 622
 623 /*
 624  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 625  * event daemon.
 626  */
 627 static void do_restore_device(struct work_struct *work)
 628 {
 629         struct dasd_device *device = container_of(work, struct dasd_device,
 630                                                   restore_device);
 631         device->cdev->drv->restore(device->cdev);
 632         dasd_put_device(device);
 633 }
 634
 635 void dasd_restore_device(struct dasd_device *device)
 636 {
 637         dasd_get_device(device);
 638         /* queue call to dasd_restore_device to the kernel event daemon. */
 639         if (!schedule_work(&device->restore_device))
 640                 dasd_put_device(device);
 641 }
 642
 643 /*
 644  * Set the target state for a device and starts the state change.
 645  */
 646 void dasd_set_target_state(struct dasd_device *device, int target)
 647 {
 648         dasd_get_device(device);
 649         mutex_lock(&device->state_mutex);
 650         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 651         if (dasd_probeonly && target > DASD_STATE_READY)
 652                 target = DASD_STATE_READY;
 653         if (device->target != target) {
 654                 if (device->state == target)
 655                         wake_up(&dasd_init_waitq);
 656                 device->target = target;
 657         }
 658         if (device->state != device->target)
 659                 dasd_change_state(device);
 660         mutex_unlock(&device->state_mutex);
 661         dasd_put_device(device);
 662 }
 663 EXPORT_SYMBOL(dasd_set_target_state);
 664
 665 /*
 666  * Enable devices with device numbers in [from..to].
 667  */
 668 static inline int _wait_for_device(struct dasd_device *device)
 669 {
 670         return (device->state == device->target);
 671 }
 672
 673 void dasd_enable_device(struct dasd_device *device)
 674 {
 675         dasd_set_target_state(device, DASD_STATE_ONLINE);
 676         if (device->state <= DASD_STATE_KNOWN)
 677                 /* No discipline for device found. */
 678                 dasd_set_target_state(device, DASD_STATE_NEW);
 679         /* Now wait for the devices to come up. */
 680         wait_event(dasd_init_waitq, _wait_for_device(device));
 681
 682         dasd_reload_device(device);
 683         if (device->discipline->kick_validate)
 684                 device->discipline->kick_validate(device);
 685 }
 686 EXPORT_SYMBOL(dasd_enable_device);
 687
 688 /*
 689  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 690  */
 691
 692 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 693
 694 #ifdef CONFIG_DASD_PROFILE
 695 struct dasd_profile dasd_global_profile = {
 696         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 697 };
 698 static struct dentry *dasd_debugfs_global_entry;
 699
 700 /*
 701  * Add profiling information for cqr before execution.
 702  */
 703 static void dasd_profile_start(struct dasd_block *block,
 704                                struct dasd_ccw_req *cqr,
 705                                struct request *req)
 706 {
 707         struct list_head *l;
 708         unsigned int counter;
 709         struct dasd_device *device;
 710
 711         /* count the length of the chanq for statistics */
 712         counter = 0;
 713         if (dasd_global_profile_level || block->profile.data)
 714                 list_for_each(l, &block->ccw_queue)
 715                         if (++counter >= 31)
 716                                 break;
 717
 718         spin_lock(&dasd_global_profile.lock);
 719         if (dasd_global_profile.data) {
 720                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 721                 if (rq_data_dir(req) == READ)
 722                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 723         }
 724         spin_unlock(&dasd_global_profile.lock);
 725
 726         spin_lock(&block->profile.lock);
 727         if (block->profile.data) {
 728                 block->profile.data->dasd_io_nr_req[counter]++;
 729                 if (rq_data_dir(req) == READ)
 730                         block->profile.data->dasd_read_nr_req[counter]++;
 731         }
 732         spin_unlock(&block->profile.lock);
 733
 734         /*
 735          * We count the request for the start device, even though it may run on
 736          * some other device due to error recovery. This way we make sure that
 737          * we count each request only once.
 738          */
 739         device = cqr->startdev;
 740         if (!device->profile.data)
 741                 return;
 742
 743         spin_lock(get_ccwdev_lock(device->cdev));
 744         counter = 1; /* request is not yet queued on the start device */
 745         list_for_each(l, &device->ccw_queue)
 746                 if (++counter >= 31)
 747                         break;
 748         spin_unlock(get_ccwdev_lock(device->cdev));
 749
 750         spin_lock(&device->profile.lock);
 751         device->profile.data->dasd_io_nr_req[counter]++;
 752         if (rq_data_dir(req) == READ)
 753                 device->profile.data->dasd_read_nr_req[counter]++;
 754         spin_unlock(&device->profile.lock);
 755 }
 756
 757 /*
 758  * Add profiling information for cqr after execution.
 759  */
 760
 761 #define dasd_profile_counter(value, index)                         \
 762 {                                                                  \
 763         for (index = 0; index < 31 && value >> (2+index); index++) \
 764                 ;                                                  \
 765 }
 766
 767 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 768                                       int is_alias,
 769                                       int is_tpm,
 770                                       int is_read,
 771                                       long sectors,
 772                                       int sectors_ind,
 773                                       int tottime_ind,
 774                                       int tottimeps_ind,
 775                                       int strtime_ind,
 776                                       int irqtime_ind,
 777                                       int irqtimeps_ind,
 778                                       int endtime_ind)
 779 {
 780         /* in case of an overflow, reset the whole profile */
 781         if (data->dasd_io_reqs == UINT_MAX) {
 782                         memset(data, 0, sizeof(*data));
 783                         ktime_get_real_ts64(&data->starttod);
 784         }
 785         data->dasd_io_reqs++;
 786         data->dasd_io_sects += sectors;
 787         if (is_alias)
 788                 data->dasd_io_alias++;
 789         if (is_tpm)
 790                 data->dasd_io_tpm++;
 791
 792         data->dasd_io_secs[sectors_ind]++;
 793         data->dasd_io_times[tottime_ind]++;
 794         data->dasd_io_timps[tottimeps_ind]++;
 795         data->dasd_io_time1[strtime_ind]++;
 796         data->dasd_io_time2[irqtime_ind]++;
 797         data->dasd_io_time2ps[irqtimeps_ind]++;
 798         data->dasd_io_time3[endtime_ind]++;
 799
 800         if (is_read) {
 801                 data->dasd_read_reqs++;
 802                 data->dasd_read_sects += sectors;
 803                 if (is_alias)
 804                         data->dasd_read_alias++;
 805                 if (is_tpm)
 806                         data->dasd_read_tpm++;
 807                 data->dasd_read_secs[sectors_ind]++;
 808                 data->dasd_read_times[tottime_ind]++;
 809                 data->dasd_read_time1[strtime_ind]++;
 810                 data->dasd_read_time2[irqtime_ind]++;
 811                 data->dasd_read_time3[endtime_ind]++;
 812         }
 813 }
 814
 815 static void dasd_profile_end(struct dasd_block *block,
 816                              struct dasd_ccw_req *cqr,
 817                              struct request *req)
 818 {
 819         unsigned long strtime, irqtime, endtime, tottime;
 820         unsigned long tottimeps, sectors;
 821         struct dasd_device *device;
 822         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 823         int irqtime_ind, irqtimeps_ind, endtime_ind;
 824         struct dasd_profile_info *data;
 825
 826         device = cqr->startdev;
 827         if (!(dasd_global_profile_level ||
 828               block->profile.data ||
 829               device->profile.data))
 830                 return;
 831
 832         sectors = blk_rq_sectors(req);
 833         if (!cqr->buildclk || !cqr->startclk ||
 834             !cqr->stopclk || !cqr->endclk ||
 835             !sectors)
 836                 return;
 837
 838         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 839         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 840         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 841         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 842         tottimeps = tottime / sectors;
 843
 844         dasd_profile_counter(sectors, sectors_ind);
 845         dasd_profile_counter(tottime, tottime_ind);
 846         dasd_profile_counter(tottimeps, tottimeps_ind);
 847         dasd_profile_counter(strtime, strtime_ind);
 848         dasd_profile_counter(irqtime, irqtime_ind);
 849         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 850         dasd_profile_counter(endtime, endtime_ind);
 851
 852         spin_lock(&dasd_global_profile.lock);
 853         if (dasd_global_profile.data) {
 854                 data = dasd_global_profile.data;
 855                 data->dasd_sum_times += tottime;
 856                 data->dasd_sum_time_str += strtime;
 857                 data->dasd_sum_time_irq += irqtime;
 858                 data->dasd_sum_time_end += endtime;
 859                 dasd_profile_end_add_data(dasd_global_profile.data,
 860                                           cqr->startdev != block->base,
 861                                           cqr->cpmode == 1,
 862                                           rq_data_dir(req) == READ,
 863                                           sectors, sectors_ind, tottime_ind,
 864                                           tottimeps_ind, strtime_ind,
 865                                           irqtime_ind, irqtimeps_ind,
 866                                           endtime_ind);
 867         }
 868         spin_unlock(&dasd_global_profile.lock);
 869
 870         spin_lock(&block->profile.lock);
 871         if (block->profile.data) {
 872                 data = block->profile.data;
 873                 data->dasd_sum_times += tottime;
 874                 data->dasd_sum_time_str += strtime;
 875                 data->dasd_sum_time_irq += irqtime;
 876                 data->dasd_sum_time_end += endtime;
 877                 dasd_profile_end_add_data(block->profile.data,
 878                                           cqr->startdev != block->base,
 879                                           cqr->cpmode == 1,
 880                                           rq_data_dir(req) == READ,
 881                                           sectors, sectors_ind, tottime_ind,
 882                                           tottimeps_ind, strtime_ind,
 883                                           irqtime_ind, irqtimeps_ind,
 884                                           endtime_ind);
 885         }
 886         spin_unlock(&block->profile.lock);
 887
 888         spin_lock(&device->profile.lock);
 889         if (device->profile.data) {
 890                 data = device->profile.data;
 891                 data->dasd_sum_times += tottime;
 892                 data->dasd_sum_time_str += strtime;
 893                 data->dasd_sum_time_irq += irqtime;
 894                 data->dasd_sum_time_end += endtime;
 895                 dasd_profile_end_add_data(device->profile.data,
 896                                           cqr->startdev != block->base,
 897                                           cqr->cpmode == 1,
 898                                           rq_data_dir(req) == READ,
 899                                           sectors, sectors_ind, tottime_ind,
 900                                           tottimeps_ind, strtime_ind,
 901                                           irqtime_ind, irqtimeps_ind,
 902                                           endtime_ind);
 903         }
 904         spin_unlock(&device->profile.lock);
 905 }
 906
 907 void dasd_profile_reset(struct dasd_profile *profile)
 908 {
 909         struct dasd_profile_info *data;
 910
 911         spin_lock_bh(&profile->lock);
 912         data = profile->data;
 913         if (!data) {
 914                 spin_unlock_bh(&profile->lock);
 915                 return;
 916         }
 917         memset(data, 0, sizeof(*data));
 918         ktime_get_real_ts64(&data->starttod);
 919         spin_unlock_bh(&profile->lock);
 920 }
 921
 922 int dasd_profile_on(struct dasd_profile *profile)
 923 {
 924         struct dasd_profile_info *data;
 925
 926         data = kzalloc(sizeof(*data), GFP_KERNEL);
 927         if (!data)
 928                 return -ENOMEM;
 929         spin_lock_bh(&profile->lock);
 930         if (profile->data) {
 931                 spin_unlock_bh(&profile->lock);
 932                 kfree(data);
 933                 return 0;
 934         }
 935         ktime_get_real_ts64(&data->starttod);
 936         profile->data = data;
 937         spin_unlock_bh(&profile->lock);
 938         return 0;
 939 }
 940
 941 void dasd_profile_off(struct dasd_profile *profile)
 942 {
 943         spin_lock_bh(&profile->lock);
 944         kfree(profile->data);
 945         profile->data = NULL;
 946         spin_unlock_bh(&profile->lock);
 947 }
 948
 949 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 950 {
 951         char *buffer;
 952
 953         buffer = vmalloc(user_len + 1);
 954         if (buffer == NULL)
 955                 return ERR_PTR(-ENOMEM);
 956         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 957                 vfree(buffer);
 958                 return ERR_PTR(-EFAULT);
 959         }
 960         /* got the string, now strip linefeed. */
 961         if (buffer[user_len - 1] == '\n')
 962                 buffer[user_len - 1] = 0;
 963         else
 964                 buffer[user_len] = 0;
 965         return buffer;
 966 }
 967
 968 static ssize_t dasd_stats_write(struct file *file,
 969                                 const char __user *user_buf,
 970                                 size_t user_len, loff_t *pos)
 971 {
 972         char *buffer, *str;
 973         int rc;
 974         struct seq_file *m = (struct seq_file *)file->private_data;
 975         struct dasd_profile *prof = m->private;
 976
 977         if (user_len > 65536)
 978                 user_len = 65536;
 979         buffer = dasd_get_user_string(user_buf, user_len);
 980         if (IS_ERR(buffer))
 981                 return PTR_ERR(buffer);
 982
 983         str = skip_spaces(buffer);
 984         rc = user_len;
 985         if (strncmp(str, "reset", 5) == 0) {
 986                 dasd_profile_reset(prof);
 987         } else if (strncmp(str, "on", 2) == 0) {
 988                 rc = dasd_profile_on(prof);
 989                 if (rc)
 990                         goto out;
 991                 rc = user_len;
 992                 if (prof == &dasd_global_profile) {
 993                         dasd_profile_reset(prof);
 994                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 995                 }
 996         } else if (strncmp(str, "off", 3) == 0) {
 997                 if (prof == &dasd_global_profile)
 998                         dasd_global_profile_level = DASD_PROFILE_OFF;
 999                 dasd_profile_off(prof);
1000         } else
1001                 rc = -EINVAL;
1002 out:
1003         vfree(buffer);
1004         return rc;
1005 }
1006
1007 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
1008 {
1009         int i;
1010
1011         for (i = 0; i < 32; i++)
1012                 seq_printf(m, "%u ", array[i]);
1013         seq_putc(m, '\n');
1014 }
1015
1016 static void dasd_stats_seq_print(struct seq_file *m,
1017                                  struct dasd_profile_info *data)
1018 {
1019         seq_printf(m, "start_time %lld.%09ld\n",
1020                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1021         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1022         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1023         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1024         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1025         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1026                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1027         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1028                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1029         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1030                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1031         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1032                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1033         seq_puts(m, "histogram_sectors ");
1034         dasd_stats_array(m, data->dasd_io_secs);
1035         seq_puts(m, "histogram_io_times ");
1036         dasd_stats_array(m, data->dasd_io_times);
1037         seq_puts(m, "histogram_io_times_weighted ");
1038         dasd_stats_array(m, data->dasd_io_timps);
1039         seq_puts(m, "histogram_time_build_to_ssch ");
1040         dasd_stats_array(m, data->dasd_io_time1);
1041         seq_puts(m, "histogram_time_ssch_to_irq ");
1042         dasd_stats_array(m, data->dasd_io_time2);
1043         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1044         dasd_stats_array(m, data->dasd_io_time2ps);
1045         seq_puts(m, "histogram_time_irq_to_end ");
1046         dasd_stats_array(m, data->dasd_io_time3);
1047         seq_puts(m, "histogram_ccw_queue_length ");
1048         dasd_stats_array(m, data->dasd_io_nr_req);
1049         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1050         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1051         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1052         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1053         seq_puts(m, "histogram_read_sectors ");
1054         dasd_stats_array(m, data->dasd_read_secs);
1055         seq_puts(m, "histogram_read_times ");
1056         dasd_stats_array(m, data->dasd_read_times);
1057         seq_puts(m, "histogram_read_time_build_to_ssch ");
1058         dasd_stats_array(m, data->dasd_read_time1);
1059         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1060         dasd_stats_array(m, data->dasd_read_time2);
1061         seq_puts(m, "histogram_read_time_irq_to_end ");
1062         dasd_stats_array(m, data->dasd_read_time3);
1063         seq_puts(m, "histogram_read_ccw_queue_length ");
1064         dasd_stats_array(m, data->dasd_read_nr_req);
1065 }
1066
1067 static int dasd_stats_show(struct seq_file *m, void *v)
1068 {
1069         struct dasd_profile *profile;
1070         struct dasd_profile_info *data;
1071
1072         profile = m->private;
1073         spin_lock_bh(&profile->lock);
1074         data = profile->data;
1075         if (!data) {
1076                 spin_unlock_bh(&profile->lock);
1077                 seq_puts(m, "disabled\n");
1078                 return 0;
1079         }
1080         dasd_stats_seq_print(m, data);
1081         spin_unlock_bh(&profile->lock);
1082         return 0;
1083 }
1084
1085 static int dasd_stats_open(struct inode *inode, struct file *file)
1086 {
1087         struct dasd_profile *profile = inode->i_private;
1088         return single_open(file, dasd_stats_show, profile);
1089 }
1090
1091 static const struct file_operations dasd_stats_raw_fops = {
1092         .owner          = THIS_MODULE,
1093         .open           = dasd_stats_open,
1094         .read           = seq_read,
1095         .llseek         = seq_lseek,
1096         .release        = single_release,
1097         .write          = dasd_stats_write,
1098 };
1099
1100 static void dasd_profile_init(struct dasd_profile *profile,
1101                               struct dentry *base_dentry)
1102 {
1103         umode_t mode;
1104         struct dentry *pde;
1105
1106         if (!base_dentry)
1107                 return;
1108         profile->dentry = NULL;
1109         profile->data = NULL;
1110         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1111         pde = debugfs_create_file("statistics", mode, base_dentry,
1112                                   profile, &dasd_stats_raw_fops);
1113         if (pde && !IS_ERR(pde))
1114                 profile->dentry = pde;
1115         return;
1116 }
1117
1118 static void dasd_profile_exit(struct dasd_profile *profile)
1119 {
1120         dasd_profile_off(profile);
1121         debugfs_remove(profile->dentry);
1122         profile->dentry = NULL;
1123 }
1124
1125 static void dasd_statistics_removeroot(void)
1126 {
1127         dasd_global_profile_level = DASD_PROFILE_OFF;
1128         dasd_profile_exit(&dasd_global_profile);
1129         debugfs_remove(dasd_debugfs_global_entry);
1130         debugfs_remove(dasd_debugfs_root_entry);
1131 }
1132
1133 static void dasd_statistics_createroot(void)
1134 {
1135         struct dentry *pde;
1136
1137         dasd_debugfs_root_entry = NULL;
1138         pde = debugfs_create_dir("dasd", NULL);
1139         if (!pde || IS_ERR(pde))
1140                 goto error;
1141         dasd_debugfs_root_entry = pde;
1142         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1143         if (!pde || IS_ERR(pde))
1144                 goto error;
1145         dasd_debugfs_global_entry = pde;
1146         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1147         return;
1148
1149 error:
1150         DBF_EVENT(DBF_ERR, "%s",
1151                   "Creation of the dasd debugfs interface failed");
1152         dasd_statistics_removeroot();
1153         return;
1154 }
1155
1156 #else
1157 #define dasd_profile_start(block, cqr, req) do {} while (0)
1158 #define dasd_profile_end(block, cqr, req) do {} while (0)
1159
1160 static void dasd_statistics_createroot(void)
1161 {
1162         return;
1163 }
1164
1165 static void dasd_statistics_removeroot(void)
1166 {
1167         return;
1168 }
1169
1170 int dasd_stats_generic_show(struct seq_file *m, void *v)
1171 {
1172         seq_puts(m, "Statistics are not activated in this kernel\n");
1173         return 0;
1174 }
1175
1176 static void dasd_profile_init(struct dasd_profile *profile,
1177                               struct dentry *base_dentry)
1178 {
1179         return;
1180 }
1181
1182 static void dasd_profile_exit(struct dasd_profile *profile)
1183 {
1184         return;
1185 }
1186
1187 int dasd_profile_on(struct dasd_profile *profile)
1188 {
1189         return 0;
1190 }
1191
1192 #endif                          /* CONFIG_DASD_PROFILE */
1193
1194 static int dasd_hosts_show(struct seq_file *m, void *v)
1195 {
1196         struct dasd_device *device;
1197         int rc = -EOPNOTSUPP;
1198
1199         device = m->private;
1200         dasd_get_device(device);
1201
1202         if (device->discipline->hosts_print)
1203                 rc = device->discipline->hosts_print(device, m);
1204
1205         dasd_put_device(device);
1206         return rc;
1207 }
1208
1209 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1210
1211 static void dasd_hosts_exit(struct dasd_device *device)
1212 {
1213         debugfs_remove(device->hosts_dentry);
1214         device->hosts_dentry = NULL;
1215 }
1216
1217 static void dasd_hosts_init(struct dentry *base_dentry,
1218                             struct dasd_device *device)
1219 {
1220         struct dentry *pde;
1221         umode_t mode;
1222
1223         if (!base_dentry)
1224                 return;
1225
1226         mode = S_IRUSR | S_IFREG;
1227         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1228                                   device, &dasd_hosts_fops);
1229         if (pde && !IS_ERR(pde))
1230                 device->hosts_dentry = pde;
1231 }
1232
1233 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1234                                           struct dasd_device *device,
1235                                           struct dasd_ccw_req *cqr)
1236 {
1237         unsigned long flags;
1238         char *data, *chunk;
1239         int size = 0;
1240
1241         if (cplength > 0)
1242                 size += cplength * sizeof(struct ccw1);
1243         if (datasize > 0)
1244                 size += datasize;
1245         if (!cqr)
1246                 size += (sizeof(*cqr) + 7L) & -8L;
1247
1248         spin_lock_irqsave(&device->mem_lock, flags);
1249         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1250         spin_unlock_irqrestore(&device->mem_lock, flags);
1251         if (!chunk)
1252                 return ERR_PTR(-ENOMEM);
1253         if (!cqr) {
1254                 cqr = (void *) data;
1255                 data += (sizeof(*cqr) + 7L) & -8L;
1256         }
1257         memset(cqr, 0, sizeof(*cqr));
1258         cqr->mem_chunk = chunk;
1259         if (cplength > 0) {
1260                 cqr->cpaddr = data;
1261                 data += cplength * sizeof(struct ccw1);
1262                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1263         }
1264         if (datasize > 0) {
1265                 cqr->data = data;
1266                 memset(cqr->data, 0, datasize);
1267         }
1268         cqr->magic = magic;
1269         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1270         dasd_get_device(device);
1271         return cqr;
1272 }
1273 EXPORT_SYMBOL(dasd_smalloc_request);
1274
1275 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1276                                           int datasize,
1277                                           struct dasd_device *device)
1278 {
1279         struct dasd_ccw_req *cqr;
1280         unsigned long flags;
1281         int size, cqr_size;
1282         char *data;
1283
1284         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1285         size = cqr_size;
1286         if (cplength > 0)
1287                 size += cplength * sizeof(struct ccw1);
1288         if (datasize > 0)
1289                 size += datasize;
1290
1291         spin_lock_irqsave(&device->mem_lock, flags);
1292         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1293         spin_unlock_irqrestore(&device->mem_lock, flags);
1294         if (!cqr)
1295                 return ERR_PTR(-ENOMEM);
1296         memset(cqr, 0, sizeof(*cqr));
1297         data = (char *)cqr + cqr_size;
1298         cqr->cpaddr = NULL;
1299         if (cplength > 0) {
1300                 cqr->cpaddr = data;
1301                 data += cplength * sizeof(struct ccw1);
1302                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1303         }
1304         cqr->data = NULL;
1305         if (datasize > 0) {
1306                 cqr->data = data;
1307                 memset(cqr->data, 0, datasize);
1308         }
1309
1310         cqr->magic = magic;
1311         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1312         dasd_get_device(device);
1313
1314         return cqr;
1315 }
1316 EXPORT_SYMBOL(dasd_fmalloc_request);
1317
1318 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1319 {
1320         unsigned long flags;
1321
1322         spin_lock_irqsave(&device->mem_lock, flags);
1323         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1324         spin_unlock_irqrestore(&device->mem_lock, flags);
1325         dasd_put_device(device);
1326 }
1327 EXPORT_SYMBOL(dasd_sfree_request);
1328
1329 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1330 {
1331         unsigned long flags;
1332
1333         spin_lock_irqsave(&device->mem_lock, flags);
1334         dasd_free_chunk(&device->ese_chunks, cqr);
1335         spin_unlock_irqrestore(&device->mem_lock, flags);
1336         dasd_put_device(device);
1337 }
1338 EXPORT_SYMBOL(dasd_ffree_request);
1339
1340 /*
1341  * Check discipline magic in cqr.
1342  */
1343 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1344 {
1345         struct dasd_device *device;
1346
1347         if (cqr == NULL)
1348                 return -EINVAL;
1349         device = cqr->startdev;
1350         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1351                 DBF_DEV_EVENT(DBF_WARNING, device,
1352                             " dasd_ccw_req 0x%08x magic doesn't match"
1353                             " discipline 0x%08x",
1354                             cqr->magic,
1355                             *(unsigned int *) device->discipline->name);
1356                 return -EINVAL;
1357         }
1358         return 0;
1359 }
1360
1361 /*
1362  * Terminate the current i/o and set the request to clear_pending.
1363  * Timer keeps device runnig.
1364  * ccw_device_clear can fail if the i/o subsystem
1365  * is in a bad mood.
1366  */
1367 int dasd_term_IO(struct dasd_ccw_req *cqr)
1368 {
1369         struct dasd_device *device;
1370         int retries, rc;
1371         char errorstring[ERRORLENGTH];
1372
1373         /* Check the cqr */
1374         rc = dasd_check_cqr(cqr);
1375         if (rc)
1376                 return rc;
1377         retries = 0;
1378         device = (struct dasd_device *) cqr->startdev;
1379         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1380                 rc = ccw_device_clear(device->cdev, (long) cqr);
1381                 switch (rc) {
1382                 case 0: /* termination successful */
1383                         cqr->status = DASD_CQR_CLEAR_PENDING;
1384                         cqr->stopclk = get_tod_clock();
1385                         cqr->starttime = 0;
1386                         DBF_DEV_EVENT(DBF_DEBUG, device,
1387                                       "terminate cqr %p successful",
1388                                       cqr);
1389                         break;
1390                 case -ENODEV:
1391                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1392                                       "device gone, retry");
1393                         break;
1394                 case -EINVAL:
1395                         /*
1396                          * device not valid so no I/O could be running
1397                          * handle CQR as termination successful
1398                          */
1399                         cqr->status = DASD_CQR_CLEARED;
1400                         cqr->stopclk = get_tod_clock();
1401                         cqr->starttime = 0;
1402                         /* no retries for invalid devices */
1403                         cqr->retries = -1;
1404                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1405                                       "EINVAL, handle as terminated");
1406                         /* fake rc to success */
1407                         rc = 0;
1408                         break;
1409                 default:
1410                         /* internal error 10 - unknown rc*/
1411                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1412                         dev_err(&device->cdev->dev, "An error occurred in the "
1413                                 "DASD device driver, reason=%s\n", errorstring);
1414                         BUG();
1415                         break;
1416                 }
1417                 retries++;
1418         }
1419         dasd_schedule_device_bh(device);
1420         return rc;
1421 }
1422 EXPORT_SYMBOL(dasd_term_IO);
1423
1424 /*
1425  * Start the i/o. This start_IO can fail if the channel is really busy.
1426  * In that case set up a timer to start the request later.
1427  */
1428 int dasd_start_IO(struct dasd_ccw_req *cqr)
1429 {
1430         struct dasd_device *device;
1431         int rc;
1432         char errorstring[ERRORLENGTH];
1433
1434         /* Check the cqr */
1435         rc = dasd_check_cqr(cqr);
1436         if (rc) {
1437                 cqr->intrc = rc;
1438                 return rc;
1439         }
1440         device = (struct dasd_device *) cqr->startdev;
1441         if (((cqr->block &&
1442               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1443              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1444             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1445                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1446                               "because of stolen lock", cqr);
1447                 cqr->status = DASD_CQR_ERROR;
1448                 cqr->intrc = -EPERM;
1449                 return -EPERM;
1450         }
1451         if (cqr->retries < 0) {
1452                 /* internal error 14 - start_IO run out of retries */
1453                 sprintf(errorstring, "14 %p", cqr);
1454                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1455                         "device driver, reason=%s\n", errorstring);
1456                 cqr->status = DASD_CQR_ERROR;
1457                 return -EIO;
1458         }
1459         cqr->startclk = get_tod_clock();
1460         cqr->starttime = jiffies;
1461         cqr->retries--;
1462         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1463                 cqr->lpm &= dasd_path_get_opm(device);
1464                 if (!cqr->lpm)
1465                         cqr->lpm = dasd_path_get_opm(device);
1466         }
1467         /*
1468          * remember the amount of formatted tracks to prevent double format on
1469          * ESE devices
1470          */
1471         if (cqr->block)
1472                 cqr->trkcount = atomic_read(&cqr->block->trkcount);
1473
1474         if (cqr->cpmode == 1) {
1475                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1476                                          (long) cqr, cqr->lpm);
1477         } else {
1478                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1479                                       (long) cqr, cqr->lpm, 0);
1480         }
1481         switch (rc) {
1482         case 0:
1483                 cqr->status = DASD_CQR_IN_IO;
1484                 break;
1485         case -EBUSY:
1486                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1487                               "start_IO: device busy, retry later");
1488                 break;
1489         case -EACCES:
1490                 /* -EACCES indicates that the request used only a subset of the
1491                  * available paths and all these paths are gone. If the lpm of
1492                  * this request was only a subset of the opm (e.g. the ppm) then
1493                  * we just do a retry with all available paths.
1494                  * If we already use the full opm, something is amiss, and we
1495                  * need a full path verification.
1496                  */
1497                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1498                         DBF_DEV_EVENT(DBF_WARNING, device,
1499                                       "start_IO: selected paths gone (%x)",
1500                                       cqr->lpm);
1501                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1502                         cqr->lpm = dasd_path_get_opm(device);
1503                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1504                                       "start_IO: selected paths gone,"
1505                                       " retry on all paths");
1506                 } else {
1507                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1508                                       "start_IO: all paths in opm gone,"
1509                                       " do path verification");
1510                         dasd_generic_last_path_gone(device);
1511                         dasd_path_no_path(device);
1512                         dasd_path_set_tbvpm(device,
1513                                           ccw_device_get_path_mask(
1514                                                   device->cdev));
1515                 }
1516                 break;
1517         case -ENODEV:
1518                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1519                               "start_IO: -ENODEV device gone, retry");
1520                 break;
1521         case -EIO:
1522                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1523                               "start_IO: -EIO device gone, retry");
1524                 break;
1525         case -EINVAL:
1526                 /* most likely caused in power management context */
1527                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1528                               "start_IO: -EINVAL device currently "
1529                               "not accessible");
1530                 break;
1531         default:
1532                 /* internal error 11 - unknown rc */
1533                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1534                 dev_err(&device->cdev->dev,
1535                         "An error occurred in the DASD device driver, "
1536                         "reason=%s\n", errorstring);
1537                 BUG();
1538                 break;
1539         }
1540         cqr->intrc = rc;
1541         return rc;
1542 }
1543 EXPORT_SYMBOL(dasd_start_IO);
1544
1545 /*
1546  * Timeout function for dasd devices. This is used for different purposes
1547  *  1) missing interrupt handler for normal operation
1548  *  2) delayed start of request where start_IO failed with -EBUSY
1549  *  3) timeout for missing state change interrupts
1550  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1551  * DASD_CQR_QUEUED for 2) and 3).
1552  */
1553 static void dasd_device_timeout(struct timer_list *t)
1554 {
1555         unsigned long flags;
1556         struct dasd_device *device;
1557
1558         device = from_timer(device, t, timer);
1559         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1560         /* re-activate request queue */
1561         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1562         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1563         dasd_schedule_device_bh(device);
1564 }
1565
1566 /*
1567  * Setup timeout for a device in jiffies.
1568  */
1569 void dasd_device_set_timer(struct dasd_device *device, int expires)
1570 {
1571         if (expires == 0)
1572                 del_timer(&device->timer);
1573         else
1574                 mod_timer(&device->timer, jiffies + expires);
1575 }
1576 EXPORT_SYMBOL(dasd_device_set_timer);
1577
1578 /*
1579  * Clear timeout for a device.
1580  */
1581 void dasd_device_clear_timer(struct dasd_device *device)
1582 {
1583         del_timer(&device->timer);
1584 }
1585 EXPORT_SYMBOL(dasd_device_clear_timer);
1586
1587 static void dasd_handle_killed_request(struct ccw_device *cdev,
1588                                        unsigned long intparm)
1589 {
1590         struct dasd_ccw_req *cqr;
1591         struct dasd_device *device;
1592
1593         if (!intparm)
1594                 return;
1595         cqr = (struct dasd_ccw_req *) intparm;
1596         if (cqr->status != DASD_CQR_IN_IO) {
1597                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1598                                 "invalid status in handle_killed_request: "
1599                                 "%02x", cqr->status);
1600                 return;
1601         }
1602
1603         device = dasd_device_from_cdev_locked(cdev);
1604         if (IS_ERR(device)) {
1605                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1606                                 "unable to get device from cdev");
1607                 return;
1608         }
1609
1610         if (!cqr->startdev ||
1611             device != cqr->startdev ||
1612             strncmp(cqr->startdev->discipline->ebcname,
1613                     (char *) &cqr->magic, 4)) {
1614                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1615                                 "invalid device in request");
1616                 dasd_put_device(device);
1617                 return;
1618         }
1619
1620         /* Schedule request to be retried. */
1621         cqr->status = DASD_CQR_QUEUED;
1622
1623         dasd_device_clear_timer(device);
1624         dasd_schedule_device_bh(device);
1625         dasd_put_device(device);
1626 }
1627
1628 void dasd_generic_handle_state_change(struct dasd_device *device)
1629 {
1630         /* First of all start sense subsystem status request. */
1631         dasd_eer_snss(device);
1632
1633         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1634         dasd_schedule_device_bh(device);
1635         if (device->block) {
1636                 dasd_schedule_block_bh(device->block);
1637                 if (device->block->request_queue)
1638                         blk_mq_run_hw_queues(device->block->request_queue,
1639                                              true);
1640         }
1641 }
1642 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1643
1644 static int dasd_check_hpf_error(struct irb *irb)
1645 {
1646         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1647             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1648              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1649 }
1650
1651 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1652 {
1653         struct dasd_device *device = NULL;
1654         u8 *sense = NULL;
1655
1656         if (!block)
1657                 return 0;
1658         device = block->base;
1659         if (!device || !device->discipline->is_ese)
1660                 return 0;
1661         if (!device->discipline->is_ese(device))
1662                 return 0;
1663
1664         sense = dasd_get_sense(irb);
1665         if (!sense)
1666                 return 0;
1667
1668         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1669                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1670                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1671 }
1672
1673 static int dasd_ese_oos_cond(u8 *sense)
1674 {
1675         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1676                 sense[1] & SNS1_PERM_ERR &&
1677                 sense[1] & SNS1_WRITE_INHIBITED &&
1678                 sense[25] == 0x01;
1679 }
1680
1681 /*
1682  * Interrupt handler for "normal" ssch-io based dasd devices.
1683  */
1684 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1685                       struct irb *irb)
1686 {
1687         struct dasd_ccw_req *cqr, *next, *fcqr;
1688         struct dasd_device *device;
1689         unsigned long now;
1690         int nrf_suppressed = 0;
1691         int fp_suppressed = 0;
1692         struct request *req;
1693         u8 *sense = NULL;
1694         int expires;
1695
1696         cqr = (struct dasd_ccw_req *) intparm;
1697         if (IS_ERR(irb)) {
1698                 switch (PTR_ERR(irb)) {
1699                 case -EIO:
1700                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1701                                 device = cqr->startdev;
1702                                 cqr->status = DASD_CQR_CLEARED;
1703                                 dasd_device_clear_timer(device);
1704                                 wake_up(&dasd_flush_wq);
1705                                 dasd_schedule_device_bh(device);
1706                                 return;
1707                         }
1708                         break;
1709                 case -ETIMEDOUT:
1710                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1711                                         "request timed out\n", __func__);
1712                         break;
1713                 default:
1714                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1715                                         "unknown error %ld\n", __func__,
1716                                         PTR_ERR(irb));
1717                 }
1718                 dasd_handle_killed_request(cdev, intparm);
1719                 return;
1720         }
1721
1722         now = get_tod_clock();
1723         /* check for conditions that should be handled immediately */
1724         if (!cqr ||
1725             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1726               scsw_cstat(&irb->scsw) == 0)) {
1727                 if (cqr)
1728                         memcpy(&cqr->irb, irb, sizeof(*irb));
1729                 device = dasd_device_from_cdev_locked(cdev);
1730                 if (IS_ERR(device))
1731                         return;
1732                 /* ignore unsolicited interrupts for DIAG discipline */
1733                 if (device->discipline == dasd_diag_discipline_pointer) {
1734                         dasd_put_device(device);
1735                         return;
1736                 }
1737
1738                 /*
1739                  * In some cases 'File Protected' or 'No Record Found' errors
1740                  * might be expected and debug log messages for the
1741                  * corresponding interrupts shouldn't be written then.
1742                  * Check if either of the according suppress bits is set.
1743                  */
1744                 sense = dasd_get_sense(irb);
1745                 if (sense) {
1746                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1747                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1748                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1749                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1750
1751                         /*
1752                          * Extent pool probably out-of-space.
1753                          * Stop device and check exhaust level.
1754                          */
1755                         if (dasd_ese_oos_cond(sense)) {
1756                                 dasd_generic_space_exhaust(device, cqr);
1757                                 device->discipline->ext_pool_exhaust(device, cqr);
1758                                 dasd_put_device(device);
1759                                 return;
1760                         }
1761                 }
1762                 if (!(fp_suppressed || nrf_suppressed))
1763                         device->discipline->dump_sense_dbf(device, irb, "int");
1764
1765                 if (device->features & DASD_FEATURE_ERPLOG)
1766                         device->discipline->dump_sense(device, cqr, irb);
1767                 device->discipline->check_for_device_change(device, cqr, irb);
1768                 dasd_put_device(device);
1769         }
1770
1771         /* check for for attention message */
1772         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1773                 device = dasd_device_from_cdev_locked(cdev);
1774                 if (!IS_ERR(device)) {
1775                         device->discipline->check_attention(device,
1776                                                             irb->esw.esw1.lpum);
1777                         dasd_put_device(device);
1778                 }
1779         }
1780
1781         if (!cqr)
1782                 return;
1783
1784         device = (struct dasd_device *) cqr->startdev;
1785         if (!device ||
1786             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1787                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1788                                 "invalid device in request");
1789                 return;
1790         }
1791
1792         if (dasd_ese_needs_format(cqr->block, irb)) {
1793                 req = dasd_get_callback_data(cqr);
1794                 if (!req) {
1795                         cqr->status = DASD_CQR_ERROR;
1796                         return;
1797                 }
1798                 if (rq_data_dir(req) == READ) {
1799                         device->discipline->ese_read(cqr, irb);
1800                         cqr->status = DASD_CQR_SUCCESS;
1801                         cqr->stopclk = now;
1802                         dasd_device_clear_timer(device);
1803                         dasd_schedule_device_bh(device);
1804                         return;
1805                 }
1806                 fcqr = device->discipline->ese_format(device, cqr, irb);
1807                 if (IS_ERR(fcqr)) {
1808                         if (PTR_ERR(fcqr) == -EINVAL) {
1809                                 cqr->status = DASD_CQR_ERROR;
1810                                 return;
1811                         }
1812                         /*
1813                          * If we can't format now, let the request go
1814                          * one extra round. Maybe we can format later.
1815                          */
1816                         cqr->status = DASD_CQR_QUEUED;
1817                         dasd_schedule_device_bh(device);
1818                         return;
1819                 } else {
1820                         fcqr->status = DASD_CQR_QUEUED;
1821                         cqr->status = DASD_CQR_QUEUED;
1822                         list_add(&fcqr->devlist, &device->ccw_queue);
1823                         dasd_schedule_device_bh(device);
1824                         return;
1825                 }
1826         }
1827
1828         /* Check for clear pending */
1829         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1830             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1831                 cqr->status = DASD_CQR_CLEARED;
1832                 dasd_device_clear_timer(device);
1833                 wake_up(&dasd_flush_wq);
1834                 dasd_schedule_device_bh(device);
1835                 return;
1836         }
1837
1838         /* check status - the request might have been killed by dyn detach */
1839         if (cqr->status != DASD_CQR_IN_IO) {
1840                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1841                               "status %02x", dev_name(&cdev->dev), cqr->status);
1842                 return;
1843         }
1844
1845         next = NULL;
1846         expires = 0;
1847         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1848             scsw_cstat(&irb->scsw) == 0) {
1849                 /* request was completed successfully */
1850                 cqr->status = DASD_CQR_SUCCESS;
1851                 cqr->stopclk = now;
1852                 /* Start first request on queue if possible -> fast_io. */
1853                 if (cqr->devlist.next != &device->ccw_queue) {
1854                         next = list_entry(cqr->devlist.next,
1855                                           struct dasd_ccw_req, devlist);
1856                 }
1857         } else {  /* error */
1858                 /* check for HPF error
1859                  * call discipline function to requeue all requests
1860                  * and disable HPF accordingly
1861                  */
1862                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1863                     device->discipline->handle_hpf_error)
1864                         device->discipline->handle_hpf_error(device, irb);
1865                 /*
1866                  * If we don't want complex ERP for this request, then just
1867                  * reset this and retry it in the fastpath
1868                  */
1869                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1870                     cqr->retries > 0) {
1871                         if (cqr->lpm == dasd_path_get_opm(device))
1872                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1873                                               "default ERP in fastpath "
1874                                               "(%i retries left)",
1875                                               cqr->retries);
1876                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1877                                 cqr->lpm = dasd_path_get_opm(device);
1878                         cqr->status = DASD_CQR_QUEUED;
1879                         next = cqr;
1880                 } else
1881                         cqr->status = DASD_CQR_ERROR;
1882         }
1883         if (next && (next->status == DASD_CQR_QUEUED) &&
1884             (!device->stopped)) {
1885                 if (device->discipline->start_IO(next) == 0)
1886                         expires = next->expires;
1887         }
1888         if (expires != 0)
1889                 dasd_device_set_timer(device, expires);
1890         else
1891                 dasd_device_clear_timer(device);
1892         dasd_schedule_device_bh(device);
1893 }
1894 EXPORT_SYMBOL(dasd_int_handler);
1895
1896 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1897 {
1898         struct dasd_device *device;
1899
1900         device = dasd_device_from_cdev_locked(cdev);
1901
1902         if (IS_ERR(device))
1903                 goto out;
1904         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1905            device->state != device->target ||
1906            !device->discipline->check_for_device_change){
1907                 dasd_put_device(device);
1908                 goto out;
1909         }
1910         if (device->discipline->dump_sense_dbf)
1911                 device->discipline->dump_sense_dbf(device, irb, "uc");
1912         device->discipline->check_for_device_change(device, NULL, irb);
1913         dasd_put_device(device);
1914 out:
1915         return UC_TODO_RETRY;
1916 }
1917 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1918
1919 /*
1920  * If we have an error on a dasd_block layer request then we cancel
1921  * and return all further requests from the same dasd_block as well.
1922  */
1923 static void __dasd_device_recovery(struct dasd_device *device,
1924                                    struct dasd_ccw_req *ref_cqr)
1925 {
1926         struct list_head *l, *n;
1927         struct dasd_ccw_req *cqr;
1928
1929         /*
1930          * only requeue request that came from the dasd_block layer
1931          */
1932         if (!ref_cqr->block)
1933                 return;
1934
1935         list_for_each_safe(l, n, &device->ccw_queue) {
1936                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1937                 if (cqr->status == DASD_CQR_QUEUED &&
1938                     ref_cqr->block == cqr->block) {
1939                         cqr->status = DASD_CQR_CLEARED;
1940                 }
1941         }
1942 };
1943
1944 /*
1945  * Remove those ccw requests from the queue that need to be returned
1946  * to the upper layer.
1947  */
1948 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1949                                             struct list_head *final_queue)
1950 {
1951         struct list_head *l, *n;
1952         struct dasd_ccw_req *cqr;
1953
1954         /* Process request with final status. */
1955         list_for_each_safe(l, n, &device->ccw_queue) {
1956                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1957
1958                 /* Skip any non-final request. */
1959                 if (cqr->status == DASD_CQR_QUEUED ||
1960                     cqr->status == DASD_CQR_IN_IO ||
1961                     cqr->status == DASD_CQR_CLEAR_PENDING)
1962                         continue;
1963                 if (cqr->status == DASD_CQR_ERROR) {
1964                         __dasd_device_recovery(device, cqr);
1965                 }
1966                 /* Rechain finished requests to final queue */
1967                 list_move_tail(&cqr->devlist, final_queue);
1968         }
1969 }
1970
1971 static void __dasd_process_cqr(struct dasd_device *device,
1972                                struct dasd_ccw_req *cqr)
1973 {
1974         char errorstring[ERRORLENGTH];
1975
1976         switch (cqr->status) {
1977         case DASD_CQR_SUCCESS:
1978                 cqr->status = DASD_CQR_DONE;
1979                 break;
1980         case DASD_CQR_ERROR:
1981                 cqr->status = DASD_CQR_NEED_ERP;
1982                 break;
1983         case DASD_CQR_CLEARED:
1984                 cqr->status = DASD_CQR_TERMINATED;
1985                 break;
1986         default:
1987                 /* internal error 12 - wrong cqr status*/
1988                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1989                 dev_err(&device->cdev->dev,
1990                         "An error occurred in the DASD device driver, "
1991                         "reason=%s\n", errorstring);
1992                 BUG();
1993         }
1994         if (cqr->callback)
1995                 cqr->callback(cqr, cqr->callback_data);
1996 }
1997
1998 /*
1999  * the cqrs from the final queue are returned to the upper layer
2000  * by setting a dasd_block state and calling the callback function
2001  */
2002 static void __dasd_device_process_final_queue(struct dasd_device *device,
2003                                               struct list_head *final_queue)
2004 {
2005         struct list_head *l, *n;
2006         struct dasd_ccw_req *cqr;
2007         struct dasd_block *block;
2008
2009         list_for_each_safe(l, n, final_queue) {
2010                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
2011                 list_del_init(&cqr->devlist);
2012                 block = cqr->block;
2013                 if (!block) {
2014                         __dasd_process_cqr(device, cqr);
2015                 } else {
2016                         spin_lock_bh(&block->queue_lock);
2017                         __dasd_process_cqr(device, cqr);
2018                         spin_unlock_bh(&block->queue_lock);
2019                 }
2020         }
2021 }
2022
2023 /*
2024  * Take a look at the first request on the ccw queue and check
2025  * if it reached its expire time. If so, terminate the IO.
2026  */
2027 static void __dasd_device_check_expire(struct dasd_device *device)
2028 {
2029         struct dasd_ccw_req *cqr;
2030
2031         if (list_empty(&device->ccw_queue))
2032                 return;
2033         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2034         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
2035             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
2036                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2037                         /*
2038                          * IO in safe offline processing should not
2039                          * run out of retries
2040                          */
2041                         cqr->retries++;
2042                 }
2043                 if (device->discipline->term_IO(cqr) != 0) {
2044                         /* Hmpf, try again in 5 sec */
2045                         dev_err(&device->cdev->dev,
2046                                 "cqr %p timed out (%lus) but cannot be "
2047                                 "ended, retrying in 5 s\n",
2048                                 cqr, (cqr->expires/HZ));
2049                         cqr->expires += 5*HZ;
2050                         dasd_device_set_timer(device, 5*HZ);
2051                 } else {
2052                         dev_err(&device->cdev->dev,
2053                                 "cqr %p timed out (%lus), %i retries "
2054                                 "remaining\n", cqr, (cqr->expires/HZ),
2055                                 cqr->retries);
2056                 }
2057         }
2058 }
2059
2060 /*
2061  * return 1 when device is not eligible for IO
2062  */
2063 static int __dasd_device_is_unusable(struct dasd_device *device,
2064                                      struct dasd_ccw_req *cqr)
2065 {
2066         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM | DASD_STOPPED_NOSPC);
2067
2068         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2069             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2070                 /*
2071                  * dasd is being set offline
2072                  * but it is no safe offline where we have to allow I/O
2073                  */
2074                 return 1;
2075         }
2076         if (device->stopped) {
2077                 if (device->stopped & mask) {
2078                         /* stopped and CQR will not change that. */
2079                         return 1;
2080                 }
2081                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2082                         /* CQR is not able to change device to
2083                          * operational. */
2084                         return 1;
2085                 }
2086                 /* CQR required to get device operational. */
2087         }
2088         return 0;
2089 }
2090
2091 /*
2092  * Take a look at the first request on the ccw queue and check
2093  * if it needs to be started.
2094  */
2095 static void __dasd_device_start_head(struct dasd_device *device)
2096 {
2097         struct dasd_ccw_req *cqr;
2098         int rc;
2099
2100         if (list_empty(&device->ccw_queue))
2101                 return;
2102         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2103         if (cqr->status != DASD_CQR_QUEUED)
2104                 return;
2105         /* if device is not usable return request to upper layer */
2106         if (__dasd_device_is_unusable(device, cqr)) {
2107                 cqr->intrc = -EAGAIN;
2108                 cqr->status = DASD_CQR_CLEARED;
2109                 dasd_schedule_device_bh(device);
2110                 return;
2111         }
2112
2113         rc = device->discipline->start_IO(cqr);
2114         if (rc == 0)
2115                 dasd_device_set_timer(device, cqr->expires);
2116         else if (rc == -EACCES) {
2117                 dasd_schedule_device_bh(device);
2118         } else
2119                 /* Hmpf, try again in 1/2 sec */
2120                 dasd_device_set_timer(device, 50);
2121 }
2122
2123 static void __dasd_device_check_path_events(struct dasd_device *device)
2124 {
2125         int rc;
2126
2127         if (!dasd_path_get_tbvpm(device))
2128                 return;
2129
2130         if (device->stopped &
2131             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2132                 return;
2133         rc = device->discipline->pe_handler(device,
2134                                             dasd_path_get_tbvpm(device));
2135         if (rc)
2136                 dasd_device_set_timer(device, 50);
2137         else
2138                 dasd_path_clear_all_verify(device);
2139 };
2140
2141 /*
2142  * Go through all request on the dasd_device request queue,
2143  * terminate them on the cdev if necessary, and return them to the
2144  * submitting layer via callback.
2145  * Note:
2146  * Make sure that all 'submitting layers' still exist when
2147  * this function is called!. In other words, when 'device' is a base
2148  * device then all block layer requests must have been removed before
2149  * via dasd_flush_block_queue.
2150  */
2151 int dasd_flush_device_queue(struct dasd_device *device)
2152 {
2153         struct dasd_ccw_req *cqr, *n;
2154         int rc;
2155         struct list_head flush_queue;
2156
2157         INIT_LIST_HEAD(&flush_queue);
2158         spin_lock_irq(get_ccwdev_lock(device->cdev));
2159         rc = 0;
2160         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2161                 /* Check status and move request to flush_queue */
2162                 switch (cqr->status) {
2163                 case DASD_CQR_IN_IO:
2164                         rc = device->discipline->term_IO(cqr);
2165                         if (rc) {
2166                                 /* unable to terminate requeust */
2167                                 dev_err(&device->cdev->dev,
2168                                         "Flushing the DASD request queue "
2169                                         "failed for request %p\n", cqr);
2170                                 /* stop flush processing */
2171                                 goto finished;
2172                         }
2173                         break;
2174                 case DASD_CQR_QUEUED:
2175                         cqr->stopclk = get_tod_clock();
2176                         cqr->status = DASD_CQR_CLEARED;
2177                         break;
2178                 default: /* no need to modify the others */
2179                         break;
2180                 }
2181                 list_move_tail(&cqr->devlist, &flush_queue);
2182         }
2183 finished:
2184         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2185         /*
2186          * After this point all requests must be in state CLEAR_PENDING,
2187          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2188          * one of the others.
2189          */
2190         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2191                 wait_event(dasd_flush_wq,
2192                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2193         /*
2194          * Now set each request back to TERMINATED, DONE or NEED_ERP
2195          * and call the callback function of flushed requests
2196          */
2197         __dasd_device_process_final_queue(device, &flush_queue);
2198         return rc;
2199 }
2200 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2201
2202 /*
2203  * Acquire the device lock and process queues for the device.
2204  */
2205 static void dasd_device_tasklet(unsigned long data)
2206 {
2207         struct dasd_device *device = (struct dasd_device *) data;
2208         struct list_head final_queue;
2209
2210         atomic_set (&device->tasklet_scheduled, 0);
2211         INIT_LIST_HEAD(&final_queue);
2212         spin_lock_irq(get_ccwdev_lock(device->cdev));
2213         /* Check expire time of first request on the ccw queue. */
2214         __dasd_device_check_expire(device);
2215         /* find final requests on ccw queue */
2216         __dasd_device_process_ccw_queue(device, &final_queue);
2217         __dasd_device_check_path_events(device);
2218         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2219         /* Now call the callback function of requests with final status */
2220         __dasd_device_process_final_queue(device, &final_queue);
2221         spin_lock_irq(get_ccwdev_lock(device->cdev));
2222         /* Now check if the head of the ccw queue needs to be started. */
2223         __dasd_device_start_head(device);
2224         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2225         if (waitqueue_active(&shutdown_waitq))
2226                 wake_up(&shutdown_waitq);
2227         dasd_put_device(device);
2228 }
2229
2230 /*
2231  * Schedules a call to dasd_tasklet over the device tasklet.
2232  */
2233 void dasd_schedule_device_bh(struct dasd_device *device)
2234 {
2235         /* Protect against rescheduling. */
2236         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2237                 return;
2238         dasd_get_device(device);
2239         tasklet_hi_schedule(&device->tasklet);
2240 }
2241 EXPORT_SYMBOL(dasd_schedule_device_bh);
2242
2243 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2244 {
2245         device->stopped |= bits;
2246 }
2247 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2248
2249 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2250 {
2251         device->stopped &= ~bits;
2252         if (!device->stopped)
2253                 wake_up(&generic_waitq);
2254 }
2255 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2256
2257 /*
2258  * Queue a request to the head of the device ccw_queue.
2259  * Start the I/O if possible.
2260  */
2261 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2262 {
2263         struct dasd_device *device;
2264         unsigned long flags;
2265
2266         device = cqr->startdev;
2267         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2268         cqr->status = DASD_CQR_QUEUED;
2269         list_add(&cqr->devlist, &device->ccw_queue);
2270         /* let the bh start the request to keep them in order */
2271         dasd_schedule_device_bh(device);
2272         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2273 }
2274 EXPORT_SYMBOL(dasd_add_request_head);
2275
2276 /*
2277  * Queue a request to the tail of the device ccw_queue.
2278  * Start the I/O if possible.
2279  */
2280 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2281 {
2282         struct dasd_device *device;
2283         unsigned long flags;
2284
2285         device = cqr->startdev;
2286         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2287         cqr->status = DASD_CQR_QUEUED;
2288         list_add_tail(&cqr->devlist, &device->ccw_queue);
2289         /* let the bh start the request to keep them in order */
2290         dasd_schedule_device_bh(device);
2291         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2292 }
2293 EXPORT_SYMBOL(dasd_add_request_tail);
2294
2295 /*
2296  * Wakeup helper for the 'sleep_on' functions.
2297  */
2298 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2299 {
2300         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2301         cqr->callback_data = DASD_SLEEPON_END_TAG;
2302         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2303         wake_up(&generic_waitq);
2304 }
2305 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2306
2307 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2308 {
2309         struct dasd_device *device;
2310         int rc;
2311
2312         device = cqr->startdev;
2313         spin_lock_irq(get_ccwdev_lock(device->cdev));
2314         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2315         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2316         return rc;
2317 }
2318
2319 /*
2320  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2321  */
2322 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2323 {
2324         struct dasd_device *device;
2325         dasd_erp_fn_t erp_fn;
2326
2327         if (cqr->status == DASD_CQR_FILLED)
2328                 return 0;
2329         device = cqr->startdev;
2330         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2331                 if (cqr->status == DASD_CQR_TERMINATED) {
2332                         device->discipline->handle_terminated_request(cqr);
2333                         return 1;
2334                 }
2335                 if (cqr->status == DASD_CQR_NEED_ERP) {
2336                         erp_fn = device->discipline->erp_action(cqr);
2337                         erp_fn(cqr);
2338                         return 1;
2339                 }
2340                 if (cqr->status == DASD_CQR_FAILED)
2341                         dasd_log_sense(cqr, &cqr->irb);
2342                 if (cqr->refers) {
2343                         __dasd_process_erp(device, cqr);
2344                         return 1;
2345                 }
2346         }
2347         return 0;
2348 }
2349
2350 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2351 {
2352         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2353                 if (cqr->refers) /* erp is not done yet */
2354                         return 1;
2355                 return ((cqr->status != DASD_CQR_DONE) &&
2356                         (cqr->status != DASD_CQR_FAILED));
2357         } else
2358                 return (cqr->status == DASD_CQR_FILLED);
2359 }
2360
2361 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2362 {
2363         struct dasd_device *device;
2364         int rc;
2365         struct list_head ccw_queue;
2366         struct dasd_ccw_req *cqr;
2367
2368         INIT_LIST_HEAD(&ccw_queue);
2369         maincqr->status = DASD_CQR_FILLED;
2370         device = maincqr->startdev;
2371         list_add(&maincqr->blocklist, &ccw_queue);
2372         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2373              cqr = list_first_entry(&ccw_queue,
2374                                     struct dasd_ccw_req, blocklist)) {
2375
2376                 if (__dasd_sleep_on_erp(cqr))
2377                         continue;
2378                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2379                         continue;
2380                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2381                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2382                         cqr->status = DASD_CQR_FAILED;
2383                         cqr->intrc = -EPERM;
2384                         continue;
2385                 }
2386                 /* Non-temporary stop condition will trigger fail fast */
2387                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2388                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2389                     (!dasd_eer_enabled(device))) {
2390                         cqr->status = DASD_CQR_FAILED;
2391                         cqr->intrc = -ENOLINK;
2392                         continue;
2393                 }
2394                 /*
2395                  * Don't try to start requests if device is in
2396                  * offline processing, it might wait forever
2397                  */
2398                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2399                         cqr->status = DASD_CQR_FAILED;
2400                         cqr->intrc = -ENODEV;
2401                         continue;
2402                 }
2403                 /*
2404                  * Don't try to start requests if device is stopped
2405                  * except path verification requests
2406                  */
2407                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2408                         if (interruptible) {
2409                                 rc = wait_event_interruptible(
2410                                         generic_waitq, !(device->stopped));
2411                                 if (rc == -ERESTARTSYS) {
2412                                         cqr->status = DASD_CQR_FAILED;
2413                                         maincqr->intrc = rc;
2414                                         continue;
2415                                 }
2416                         } else
2417                                 wait_event(generic_waitq, !(device->stopped));
2418                 }
2419                 if (!cqr->callback)
2420                         cqr->callback = dasd_wakeup_cb;
2421
2422                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2423                 dasd_add_request_tail(cqr);
2424                 if (interruptible) {
2425                         rc = wait_event_interruptible(
2426                                 generic_waitq, _wait_for_wakeup(cqr));
2427                         if (rc == -ERESTARTSYS) {
2428                                 dasd_cancel_req(cqr);
2429                                 /* wait (non-interruptible) for final status */
2430                                 wait_event(generic_waitq,
2431                                            _wait_for_wakeup(cqr));
2432                                 cqr->status = DASD_CQR_FAILED;
2433                                 maincqr->intrc = rc;
2434                                 continue;
2435                         }
2436                 } else
2437                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2438         }
2439
2440         maincqr->endclk = get_tod_clock();
2441         if ((maincqr->status != DASD_CQR_DONE) &&
2442             (maincqr->intrc != -ERESTARTSYS))
2443                 dasd_log_sense(maincqr, &maincqr->irb);
2444         if (maincqr->status == DASD_CQR_DONE)
2445                 rc = 0;
2446         else if (maincqr->intrc)
2447                 rc = maincqr->intrc;
2448         else
2449                 rc = -EIO;
2450         return rc;
2451 }
2452
2453 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2454 {
2455         struct dasd_ccw_req *cqr;
2456
2457         list_for_each_entry(cqr, ccw_queue, blocklist) {
2458                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2459                         return 0;
2460         }
2461
2462         return 1;
2463 }
2464
2465 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2466 {
2467         struct dasd_device *device;
2468         struct dasd_ccw_req *cqr, *n;
2469         u8 *sense = NULL;
2470         int rc;
2471
2472 retry:
2473         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2474                 device = cqr->startdev;
2475                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2476                         continue;
2477
2478                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2479                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2480                         cqr->status = DASD_CQR_FAILED;
2481                         cqr->intrc = -EPERM;
2482                         continue;
2483                 }
2484                 /*Non-temporary stop condition will trigger fail fast*/
2485                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2486                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2487                     !dasd_eer_enabled(device)) {
2488                         cqr->status = DASD_CQR_FAILED;
2489                         cqr->intrc = -EAGAIN;
2490                         continue;
2491                 }
2492
2493                 /*Don't try to start requests if device is stopped*/
2494                 if (interruptible) {
2495                         rc = wait_event_interruptible(
2496                                 generic_waitq, !device->stopped);
2497                         if (rc == -ERESTARTSYS) {
2498                                 cqr->status = DASD_CQR_FAILED;
2499                                 cqr->intrc = rc;
2500                                 continue;
2501                         }
2502                 } else
2503                         wait_event(generic_waitq, !(device->stopped));
2504
2505                 if (!cqr->callback)
2506                         cqr->callback = dasd_wakeup_cb;
2507                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2508                 dasd_add_request_tail(cqr);
2509         }
2510
2511         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2512
2513         rc = 0;
2514         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2515                 /*
2516                  * In some cases the 'File Protected' or 'Incorrect Length'
2517                  * error might be expected and error recovery would be
2518                  * unnecessary in these cases.  Check if the according suppress
2519                  * bit is set.
2520                  */
2521                 sense = dasd_get_sense(&cqr->irb);
2522                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2523                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2524                         continue;
2525                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2526                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2527                         continue;
2528
2529                 /*
2530                  * for alias devices simplify error recovery and
2531                  * return to upper layer
2532                  * do not skip ERP requests
2533                  */
2534                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2535                     (cqr->status == DASD_CQR_TERMINATED ||
2536                      cqr->status == DASD_CQR_NEED_ERP))
2537                         return -EAGAIN;
2538
2539                 /* normal recovery for basedev IO */
2540                 if (__dasd_sleep_on_erp(cqr))
2541                         /* handle erp first */
2542                         goto retry;
2543         }
2544
2545         return 0;
2546 }
2547
2548 /*
2549  * Queue a request to the tail of the device ccw_queue and wait for
2550  * it's completion.
2551  */
2552 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2553 {
2554         return _dasd_sleep_on(cqr, 0);
2555 }
2556 EXPORT_SYMBOL(dasd_sleep_on);
2557
2558 /*
2559  * Start requests from a ccw_queue and wait for their completion.
2560  */
2561 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2562 {
2563         return _dasd_sleep_on_queue(ccw_queue, 0);
2564 }
2565 EXPORT_SYMBOL(dasd_sleep_on_queue);
2566
2567 /*
2568  * Start requests from a ccw_queue and wait interruptible for their completion.
2569  */
2570 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2571 {
2572         return _dasd_sleep_on_queue(ccw_queue, 1);
2573 }
2574 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2575
2576 /*
2577  * Queue a request to the tail of the device ccw_queue and wait
2578  * interruptible for it's completion.
2579  */
2580 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2581 {
2582         return _dasd_sleep_on(cqr, 1);
2583 }
2584 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2585
2586 /*
2587  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2588  * for eckd devices) the currently running request has to be terminated
2589  * and be put back to status queued, before the special request is added
2590  * to the head of the queue. Then the special request is waited on normally.
2591  */
2592 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2593 {
2594         struct dasd_ccw_req *cqr;
2595         int rc;
2596
2597         if (list_empty(&device->ccw_queue))
2598                 return 0;
2599         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2600         rc = device->discipline->term_IO(cqr);
2601         if (!rc)
2602                 /*
2603                  * CQR terminated because a more important request is pending.
2604                  * Undo decreasing of retry counter because this is
2605                  * not an error case.
2606                  */
2607                 cqr->retries++;
2608         return rc;
2609 }
2610
2611 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2612 {
2613         struct dasd_device *device;
2614         int rc;
2615
2616         device = cqr->startdev;
2617         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2618             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2619                 cqr->status = DASD_CQR_FAILED;
2620                 cqr->intrc = -EPERM;
2621                 return -EIO;
2622         }
2623         spin_lock_irq(get_ccwdev_lock(device->cdev));
2624         rc = _dasd_term_running_cqr(device);
2625         if (rc) {
2626                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2627                 return rc;
2628         }
2629         cqr->callback = dasd_wakeup_cb;
2630         cqr->callback_data = DASD_SLEEPON_START_TAG;
2631         cqr->status = DASD_CQR_QUEUED;
2632         /*
2633          * add new request as second
2634          * first the terminated cqr needs to be finished
2635          */
2636         list_add(&cqr->devlist, device->ccw_queue.next);
2637
2638         /* let the bh start the request to keep them in order */
2639         dasd_schedule_device_bh(device);
2640
2641         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2642
2643         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2644
2645         if (cqr->status == DASD_CQR_DONE)
2646                 rc = 0;
2647         else if (cqr->intrc)
2648                 rc = cqr->intrc;
2649         else
2650                 rc = -EIO;
2651
2652         /* kick tasklets */
2653         dasd_schedule_device_bh(device);
2654         if (device->block)
2655                 dasd_schedule_block_bh(device->block);
2656
2657         return rc;
2658 }
2659 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2660
2661 /*
2662  * Cancels a request that was started with dasd_sleep_on_req.
2663  * This is useful to timeout requests. The request will be
2664  * terminated if it is currently in i/o.
2665  * Returns 0 if request termination was successful
2666  *         negative error code if termination failed
2667  * Cancellation of a request is an asynchronous operation! The calling
2668  * function has to wait until the request is properly returned via callback.
2669  */
2670 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2671 {
2672         struct dasd_device *device = cqr->startdev;
2673         int rc = 0;
2674
2675         switch (cqr->status) {
2676         case DASD_CQR_QUEUED:
2677                 /* request was not started - just set to cleared */
2678                 cqr->status = DASD_CQR_CLEARED;
2679                 break;
2680         case DASD_CQR_IN_IO:
2681                 /* request in IO - terminate IO and release again */
2682                 rc = device->discipline->term_IO(cqr);
2683                 if (rc) {
2684                         dev_err(&device->cdev->dev,
2685                                 "Cancelling request %p failed with rc=%d\n",
2686                                 cqr, rc);
2687                 } else {
2688                         cqr->stopclk = get_tod_clock();
2689                 }
2690                 break;
2691         default: /* already finished or clear pending - do nothing */
2692                 break;
2693         }
2694         dasd_schedule_device_bh(device);
2695         return rc;
2696 }
2697
2698 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2699 {
2700         struct dasd_device *device = cqr->startdev;
2701         unsigned long flags;
2702         int rc;
2703
2704         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2705         rc = __dasd_cancel_req(cqr);
2706         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2707         return rc;
2708 }
2709
2710 /*
2711  * SECTION: Operations of the dasd_block layer.
2712  */
2713
2714 /*
2715  * Timeout function for dasd_block. This is used when the block layer
2716  * is waiting for something that may not come reliably, (e.g. a state
2717  * change interrupt)
2718  */
2719 static void dasd_block_timeout(struct timer_list *t)
2720 {
2721         unsigned long flags;
2722         struct dasd_block *block;
2723
2724         block = from_timer(block, t, timer);
2725         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2726         /* re-activate request queue */
2727         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2728         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2729         dasd_schedule_block_bh(block);
2730         blk_mq_run_hw_queues(block->request_queue, true);
2731 }
2732
2733 /*
2734  * Setup timeout for a dasd_block in jiffies.
2735  */
2736 void dasd_block_set_timer(struct dasd_block *block, int expires)
2737 {
2738         if (expires == 0)
2739                 del_timer(&block->timer);
2740         else
2741                 mod_timer(&block->timer, jiffies + expires);
2742 }
2743 EXPORT_SYMBOL(dasd_block_set_timer);
2744
2745 /*
2746  * Clear timeout for a dasd_block.
2747  */
2748 void dasd_block_clear_timer(struct dasd_block *block)
2749 {
2750         del_timer(&block->timer);
2751 }
2752 EXPORT_SYMBOL(dasd_block_clear_timer);
2753
2754 /*
2755  * Process finished error recovery ccw.
2756  */
2757 static void __dasd_process_erp(struct dasd_device *device,
2758                                struct dasd_ccw_req *cqr)
2759 {
2760         dasd_erp_fn_t erp_fn;
2761
2762         if (cqr->status == DASD_CQR_DONE)
2763                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2764         else
2765                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2766         erp_fn = device->discipline->erp_postaction(cqr);
2767         erp_fn(cqr);
2768 }
2769
2770 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2771 {
2772         struct request *req;
2773         blk_status_t error = BLK_STS_OK;
2774         unsigned int proc_bytes;
2775         int status;
2776
2777         req = (struct request *) cqr->callback_data;
2778         dasd_profile_end(cqr->block, cqr, req);
2779
2780         proc_bytes = cqr->proc_bytes;
2781         status = cqr->block->base->discipline->free_cp(cqr, req);
2782         if (status < 0)
2783                 error = errno_to_blk_status(status);
2784         else if (status == 0) {
2785                 switch (cqr->intrc) {
2786                 case -EPERM:
2787                         error = BLK_STS_NEXUS;
2788                         break;
2789                 case -ENOLINK:
2790                         error = BLK_STS_TRANSPORT;
2791                         break;
2792                 case -ETIMEDOUT:
2793                         error = BLK_STS_TIMEOUT;
2794                         break;
2795                 default:
2796                         error = BLK_STS_IOERR;
2797                         break;
2798                 }
2799         }
2800
2801         /*
2802          * We need to take care for ETIMEDOUT errors here since the
2803          * complete callback does not get called in this case.
2804          * Take care of all errors here and avoid additional code to
2805          * transfer the error value to the complete callback.
2806          */
2807         if (error) {
2808                 blk_mq_end_request(req, error);
2809                 blk_mq_run_hw_queues(req->q, true);
2810         } else {
2811                 /*
2812                  * Partial completed requests can happen with ESE devices.
2813                  * During read we might have gotten a NRF error and have to
2814                  * complete a request partially.
2815                  */
2816                 if (proc_bytes) {
2817                         blk_update_request(req, BLK_STS_OK, proc_bytes);
2818                         blk_mq_requeue_request(req, true);
2819                 } else if (likely(!blk_should_fake_timeout(req->q))) {
2820                         blk_mq_complete_request(req);
2821                 }
2822         }
2823 }
2824
2825 /*
2826  * Process ccw request queue.
2827  */
2828 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2829                                            struct list_head *final_queue)
2830 {
2831         struct list_head *l, *n;
2832         struct dasd_ccw_req *cqr;
2833         dasd_erp_fn_t erp_fn;
2834         unsigned long flags;
2835         struct dasd_device *base = block->base;
2836
2837 restart:
2838         /* Process request with final status. */
2839         list_for_each_safe(l, n, &block->ccw_queue) {
2840                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2841                 if (cqr->status != DASD_CQR_DONE &&
2842                     cqr->status != DASD_CQR_FAILED &&
2843                     cqr->status != DASD_CQR_NEED_ERP &&
2844                     cqr->status != DASD_CQR_TERMINATED)
2845                         continue;
2846
2847                 if (cqr->status == DASD_CQR_TERMINATED) {
2848                         base->discipline->handle_terminated_request(cqr);
2849                         goto restart;
2850                 }
2851
2852                 /*  Process requests that may be recovered */
2853                 if (cqr->status == DASD_CQR_NEED_ERP) {
2854                         erp_fn = base->discipline->erp_action(cqr);
2855                         if (IS_ERR(erp_fn(cqr)))
2856                                 continue;
2857                         goto restart;
2858                 }
2859
2860                 /* log sense for fatal error */
2861                 if (cqr->status == DASD_CQR_FAILED) {
2862                         dasd_log_sense(cqr, &cqr->irb);
2863                 }
2864
2865                 /* First of all call extended error reporting. */
2866                 if (dasd_eer_enabled(base) &&
2867                     cqr->status == DASD_CQR_FAILED) {
2868                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2869
2870                         /* restart request  */
2871                         cqr->status = DASD_CQR_FILLED;
2872                         cqr->retries = 255;
2873                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2874                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2875                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2876                                                flags);
2877                         goto restart;
2878                 }
2879
2880                 /* Process finished ERP request. */
2881                 if (cqr->refers) {
2882                         __dasd_process_erp(base, cqr);
2883                         goto restart;
2884                 }
2885
2886                 /* Rechain finished requests to final queue */
2887                 cqr->endclk = get_tod_clock();
2888                 list_move_tail(&cqr->blocklist, final_queue);
2889         }
2890 }
2891
2892 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2893 {
2894         dasd_schedule_block_bh(cqr->block);
2895 }
2896
2897 static void __dasd_block_start_head(struct dasd_block *block)
2898 {
2899         struct dasd_ccw_req *cqr;
2900
2901         if (list_empty(&block->ccw_queue))
2902                 return;
2903         /* We allways begin with the first requests on the queue, as some
2904          * of previously started requests have to be enqueued on a
2905          * dasd_device again for error recovery.
2906          */
2907         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2908                 if (cqr->status != DASD_CQR_FILLED)
2909                         continue;
2910                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2911                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2912                         cqr->status = DASD_CQR_FAILED;
2913                         cqr->intrc = -EPERM;
2914                         dasd_schedule_block_bh(block);
2915                         continue;
2916                 }
2917                 /* Non-temporary stop condition will trigger fail fast */
2918                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2919                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2920                     (!dasd_eer_enabled(block->base))) {
2921                         cqr->status = DASD_CQR_FAILED;
2922                         cqr->intrc = -ENOLINK;
2923                         dasd_schedule_block_bh(block);
2924                         continue;
2925                 }
2926                 /* Don't try to start requests if device is stopped */
2927                 if (block->base->stopped)
2928                         return;
2929
2930                 /* just a fail safe check, should not happen */
2931                 if (!cqr->startdev)
2932                         cqr->startdev = block->base;
2933
2934                 /* make sure that the requests we submit find their way back */
2935                 cqr->callback = dasd_return_cqr_cb;
2936
2937                 dasd_add_request_tail(cqr);
2938         }
2939 }
2940
2941 /*
2942  * Central dasd_block layer routine. Takes requests from the generic
2943  * block layer request queue, creates ccw requests, enqueues them on
2944  * a dasd_device and processes ccw requests that have been returned.
2945  */
2946 static void dasd_block_tasklet(unsigned long data)
2947 {
2948         struct dasd_block *block = (struct dasd_block *) data;
2949         struct list_head final_queue;
2950         struct list_head *l, *n;
2951         struct dasd_ccw_req *cqr;
2952         struct dasd_queue *dq;
2953
2954         atomic_set(&block->tasklet_scheduled, 0);
2955         INIT_LIST_HEAD(&final_queue);
2956         spin_lock_irq(&block->queue_lock);
2957         /* Finish off requests on ccw queue */
2958         __dasd_process_block_ccw_queue(block, &final_queue);
2959         spin_unlock_irq(&block->queue_lock);
2960
2961         /* Now call the callback function of requests with final status */
2962         list_for_each_safe(l, n, &final_queue) {
2963                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2964                 dq = cqr->dq;
2965                 spin_lock_irq(&dq->lock);
2966                 list_del_init(&cqr->blocklist);
2967                 __dasd_cleanup_cqr(cqr);
2968                 spin_unlock_irq(&dq->lock);
2969         }
2970
2971         spin_lock_irq(&block->queue_lock);
2972         /* Now check if the head of the ccw queue needs to be started. */
2973         __dasd_block_start_head(block);
2974         spin_unlock_irq(&block->queue_lock);
2975
2976         if (waitqueue_active(&shutdown_waitq))
2977                 wake_up(&shutdown_waitq);
2978         dasd_put_device(block->base);
2979 }
2980
2981 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2982 {
2983         wake_up(&dasd_flush_wq);
2984 }
2985
2986 /*
2987  * Requeue a request back to the block request queue
2988  * only works for block requests
2989  */
2990 static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
2991 {
2992         struct request *req;
2993
2994         /*
2995          * If the request is an ERP request there is nothing to requeue.
2996          * This will be done with the remaining original request.
2997          */
2998         if (cqr->refers)
2999                 return;
3000         spin_lock_irq(&cqr->dq->lock);
3001         req = (struct request *) cqr->callback_data;
3002         blk_mq_requeue_request(req, true);
3003         spin_unlock_irq(&cqr->dq->lock);
3004
3005         return;
3006 }
3007
3008 static int _dasd_requests_to_flushqueue(struct dasd_block *block,
3009                                         struct list_head *flush_queue)
3010 {
3011         struct dasd_ccw_req *cqr, *n;
3012         unsigned long flags;
3013         int rc, i;
3014
3015         spin_lock_irqsave(&block->queue_lock, flags);
3016         rc = 0;
3017 restart:
3018         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
3019                 /* if this request currently owned by a dasd_device cancel it */
3020                 if (cqr->status >= DASD_CQR_QUEUED)
3021                         rc = dasd_cancel_req(cqr);
3022                 if (rc < 0)
3023                         break;
3024                 /* Rechain request (including erp chain) so it won't be
3025                  * touched by the dasd_block_tasklet anymore.
3026                  * Replace the callback so we notice when the request
3027                  * is returned from the dasd_device layer.
3028                  */
3029                 cqr->callback = _dasd_wake_block_flush_cb;
3030                 for (i = 0; cqr; cqr = cqr->refers, i++)
3031                         list_move_tail(&cqr->blocklist, flush_queue);
3032                 if (i > 1)
3033                         /* moved more than one request - need to restart */
3034                         goto restart;
3035         }
3036         spin_unlock_irqrestore(&block->queue_lock, flags);
3037
3038         return rc;
3039 }
3040
3041 /*
3042  * Go through all request on the dasd_block request queue, cancel them
3043  * on the respective dasd_device, and return them to the generic
3044  * block layer.
3045  */
3046 static int dasd_flush_block_queue(struct dasd_block *block)
3047 {
3048         struct dasd_ccw_req *cqr, *n;
3049         struct list_head flush_queue;
3050         unsigned long flags;
3051         int rc;
3052
3053         INIT_LIST_HEAD(&flush_queue);
3054         rc = _dasd_requests_to_flushqueue(block, &flush_queue);
3055
3056         /* Now call the callback function of flushed requests */
3057 restart_cb:
3058         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3059                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3060                 /* Process finished ERP request. */
3061                 if (cqr->refers) {
3062                         spin_lock_bh(&block->queue_lock);
3063                         __dasd_process_erp(block->base, cqr);
3064                         spin_unlock_bh(&block->queue_lock);
3065                         /* restart list_for_xx loop since dasd_process_erp
3066                          * might remove multiple elements */
3067                         goto restart_cb;
3068                 }
3069                 /* call the callback function */
3070                 spin_lock_irqsave(&cqr->dq->lock, flags);
3071                 cqr->endclk = get_tod_clock();
3072                 list_del_init(&cqr->blocklist);
3073                 __dasd_cleanup_cqr(cqr);
3074                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3075         }
3076         return rc;
3077 }
3078
3079 /*
3080  * Schedules a call to dasd_tasklet over the device tasklet.
3081  */
3082 void dasd_schedule_block_bh(struct dasd_block *block)
3083 {
3084         /* Protect against rescheduling. */
3085         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3086                 return;
3087         /* life cycle of block is bound to it's base device */
3088         dasd_get_device(block->base);
3089         tasklet_hi_schedule(&block->tasklet);
3090 }
3091 EXPORT_SYMBOL(dasd_schedule_block_bh);
3092
3093
3094 /*
3095  * SECTION: external block device operations
3096  * (request queue handling, open, release, etc.)
3097  */
3098
3099 /*
3100  * Dasd request queue function. Called from ll_rw_blk.c
3101  */
3102 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3103                                     const struct blk_mq_queue_data *qd)
3104 {
3105         struct dasd_block *block = hctx->queue->queuedata;
3106         struct dasd_queue *dq = hctx->driver_data;
3107         struct request *req = qd->rq;
3108         struct dasd_device *basedev;
3109         struct dasd_ccw_req *cqr;
3110         blk_status_t rc = BLK_STS_OK;
3111
3112         basedev = block->base;
3113         spin_lock_irq(&dq->lock);
3114         if (basedev->state < DASD_STATE_READY ||
3115             test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3116                 DBF_DEV_EVENT(DBF_ERR, basedev,
3117                               "device not ready for request %p", req);
3118                 rc = BLK_STS_IOERR;
3119                 goto out;
3120         }
3121
3122         /*
3123          * if device is stopped do not fetch new requests
3124          * except failfast is active which will let requests fail
3125          * immediately in __dasd_block_start_head()
3126          */
3127         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3128                 DBF_DEV_EVENT(DBF_ERR, basedev,
3129                               "device stopped request %p", req);
3130                 rc = BLK_STS_RESOURCE;
3131                 goto out;
3132         }
3133
3134         if (basedev->features & DASD_FEATURE_READONLY &&
3135             rq_data_dir(req) == WRITE) {
3136                 DBF_DEV_EVENT(DBF_ERR, basedev,
3137                               "Rejecting write request %p", req);
3138                 rc = BLK_STS_IOERR;
3139                 goto out;
3140         }
3141
3142         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3143             (basedev->features & DASD_FEATURE_FAILFAST ||
3144              blk_noretry_request(req))) {
3145                 DBF_DEV_EVENT(DBF_ERR, basedev,
3146                               "Rejecting failfast request %p", req);
3147                 rc = BLK_STS_IOERR;
3148                 goto out;
3149         }
3150
3151         cqr = basedev->discipline->build_cp(basedev, block, req);
3152         if (IS_ERR(cqr)) {
3153                 if (PTR_ERR(cqr) == -EBUSY ||
3154                     PTR_ERR(cqr) == -ENOMEM ||
3155                     PTR_ERR(cqr) == -EAGAIN) {
3156                         rc = BLK_STS_RESOURCE;
3157                         goto out;
3158                 }
3159                 DBF_DEV_EVENT(DBF_ERR, basedev,
3160                               "CCW creation failed (rc=%ld) on request %p",
3161                               PTR_ERR(cqr), req);
3162                 rc = BLK_STS_IOERR;
3163                 goto out;
3164         }
3165         /*
3166          *  Note: callback is set to dasd_return_cqr_cb in
3167          * __dasd_block_start_head to cover erp requests as well
3168          */
3169         cqr->callback_data = req;
3170         cqr->status = DASD_CQR_FILLED;
3171         cqr->dq = dq;
3172
3173         blk_mq_start_request(req);
3174         spin_lock(&block->queue_lock);
3175         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3176         INIT_LIST_HEAD(&cqr->devlist);
3177         dasd_profile_start(block, cqr, req);
3178         dasd_schedule_block_bh(block);
3179         spin_unlock(&block->queue_lock);
3180
3181 out:
3182         spin_unlock_irq(&dq->lock);
3183         return rc;
3184 }
3185
3186 /*
3187  * Block timeout callback, called from the block layer
3188  *
3189  * Return values:
3190  * BLK_EH_RESET_TIMER if the request should be left running
3191  * BLK_EH_DONE if the request is handled or terminated
3192  *                    by the driver.
3193  */
3194 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3195 {
3196         struct dasd_block *block = req->q->queuedata;
3197         struct dasd_device *device;
3198         struct dasd_ccw_req *cqr;
3199         unsigned long flags;
3200         int rc = 0;
3201
3202         cqr = blk_mq_rq_to_pdu(req);
3203         if (!cqr)
3204                 return BLK_EH_DONE;
3205
3206         spin_lock_irqsave(&cqr->dq->lock, flags);
3207         device = cqr->startdev ? cqr->startdev : block->base;
3208         if (!device->blk_timeout) {
3209                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3210                 return BLK_EH_RESET_TIMER;
3211         }
3212         DBF_DEV_EVENT(DBF_WARNING, device,
3213                       " dasd_times_out cqr %p status %x",
3214                       cqr, cqr->status);
3215
3216         spin_lock(&block->queue_lock);
3217         spin_lock(get_ccwdev_lock(device->cdev));
3218         cqr->retries = -1;
3219         cqr->intrc = -ETIMEDOUT;
3220         if (cqr->status >= DASD_CQR_QUEUED) {
3221                 rc = __dasd_cancel_req(cqr);
3222         } else if (cqr->status == DASD_CQR_FILLED ||
3223                    cqr->status == DASD_CQR_NEED_ERP) {
3224                 cqr->status = DASD_CQR_TERMINATED;
3225         } else if (cqr->status == DASD_CQR_IN_ERP) {
3226                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3227
3228                 list_for_each_entry_safe(searchcqr, nextcqr,
3229                                          &block->ccw_queue, blocklist) {
3230                         tmpcqr = searchcqr;
3231                         while (tmpcqr->refers)
3232                                 tmpcqr = tmpcqr->refers;
3233                         if (tmpcqr != cqr)
3234                                 continue;
3235                         /* searchcqr is an ERP request for cqr */
3236                         searchcqr->retries = -1;
3237                         searchcqr->intrc = -ETIMEDOUT;
3238                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3239                                 rc = __dasd_cancel_req(searchcqr);
3240                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3241                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3242                                 searchcqr->status = DASD_CQR_TERMINATED;
3243                                 rc = 0;
3244                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3245                                 /*
3246                                  * Shouldn't happen; most recent ERP
3247                                  * request is at the front of queue
3248                                  */
3249                                 continue;
3250                         }
3251                         break;
3252                 }
3253         }
3254         spin_unlock(get_ccwdev_lock(device->cdev));
3255         dasd_schedule_block_bh(block);
3256         spin_unlock(&block->queue_lock);
3257         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3258
3259         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3260 }
3261
3262 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3263                           unsigned int idx)
3264 {
3265         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3266
3267         if (!dq)
3268                 return -ENOMEM;
3269
3270         spin_lock_init(&dq->lock);
3271         hctx->driver_data = dq;
3272
3273         return 0;
3274 }
3275
3276 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3277 {
3278         kfree(hctx->driver_data);
3279         hctx->driver_data = NULL;
3280 }
3281
3282 static void dasd_request_done(struct request *req)
3283 {
3284         blk_mq_end_request(req, 0);
3285         blk_mq_run_hw_queues(req->q, true);
3286 }
3287
3288 static struct blk_mq_ops dasd_mq_ops = {
3289         .queue_rq = do_dasd_request,
3290         .complete = dasd_request_done,
3291         .timeout = dasd_times_out,
3292         .init_hctx = dasd_init_hctx,
3293         .exit_hctx = dasd_exit_hctx,
3294 };
3295
3296 /*
3297  * Allocate and initialize request queue and default I/O scheduler.
3298  */
3299 static int dasd_alloc_queue(struct dasd_block *block)
3300 {
3301         int rc;
3302
3303         block->tag_set.ops = &dasd_mq_ops;
3304         block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3305         block->tag_set.nr_hw_queues = nr_hw_queues;
3306         block->tag_set.queue_depth = queue_depth;
3307         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3308         block->tag_set.numa_node = NUMA_NO_NODE;
3309
3310         rc = blk_mq_alloc_tag_set(&block->tag_set);
3311         if (rc)
3312                 return rc;
3313
3314         block->request_queue = blk_mq_init_queue(&block->tag_set);
3315         if (IS_ERR(block->request_queue))
3316                 return PTR_ERR(block->request_queue);
3317
3318         block->request_queue->queuedata = block;
3319
3320         return 0;
3321 }
3322
3323 /*
3324  * Deactivate and free request queue.
3325  */
3326 static void dasd_free_queue(struct dasd_block *block)
3327 {
3328         if (block->request_queue) {
3329                 blk_cleanup_queue(block->request_queue);
3330                 blk_mq_free_tag_set(&block->tag_set);
3331                 block->request_queue = NULL;
3332         }
3333 }
3334
3335 static int dasd_open(struct block_device *bdev, fmode_t mode)
3336 {
3337         struct dasd_device *base;
3338         int rc;
3339
3340         base = dasd_device_from_gendisk(bdev->bd_disk);
3341         if (!base)
3342                 return -ENODEV;
3343
3344         atomic_inc(&base->block->open_count);
3345         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3346                 rc = -ENODEV;
3347                 goto unlock;
3348         }
3349
3350         if (!try_module_get(base->discipline->owner)) {
3351                 rc = -EINVAL;
3352                 goto unlock;
3353         }
3354
3355         if (dasd_probeonly) {
3356                 dev_info(&base->cdev->dev,
3357                          "Accessing the DASD failed because it is in "
3358                          "probeonly mode\n");
3359                 rc = -EPERM;
3360                 goto out;
3361         }
3362
3363         if (base->state <= DASD_STATE_BASIC) {
3364                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3365                               " Cannot open unrecognized device");
3366                 rc = -ENODEV;
3367                 goto out;
3368         }
3369
3370         if ((mode & FMODE_WRITE) &&
3371             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3372              (base->features & DASD_FEATURE_READONLY))) {
3373                 rc = -EROFS;
3374                 goto out;
3375         }
3376
3377         dasd_put_device(base);
3378         return 0;
3379
3380 out:
3381         module_put(base->discipline->owner);
3382 unlock:
3383         atomic_dec(&base->block->open_count);
3384         dasd_put_device(base);
3385         return rc;
3386 }
3387
3388 static void dasd_release(struct gendisk *disk, fmode_t mode)
3389 {
3390         struct dasd_device *base = dasd_device_from_gendisk(disk);
3391         if (base) {
3392                 atomic_dec(&base->block->open_count);
3393                 module_put(base->discipline->owner);
3394                 dasd_put_device(base);
3395         }
3396 }
3397
3398 /*
3399  * Return disk geometry.
3400  */
3401 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3402 {
3403         struct dasd_device *base;
3404
3405         base = dasd_device_from_gendisk(bdev->bd_disk);
3406         if (!base)
3407                 return -ENODEV;
3408
3409         if (!base->discipline ||
3410             !base->discipline->fill_geometry) {
3411                 dasd_put_device(base);
3412                 return -EINVAL;
3413         }
3414         base->discipline->fill_geometry(base->block, geo);
3415         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3416         dasd_put_device(base);
3417         return 0;
3418 }
3419
3420 const struct block_device_operations
3421 dasd_device_operations = {
3422         .owner          = THIS_MODULE,
3423         .open           = dasd_open,
3424         .release        = dasd_release,
3425         .ioctl          = dasd_ioctl,
3426         .compat_ioctl   = dasd_ioctl,
3427         .getgeo         = dasd_getgeo,
3428 };
3429
3430 /*******************************************************************************
3431  * end of block device operations
3432  */
3433
3434 static void
3435 dasd_exit(void)
3436 {
3437 #ifdef CONFIG_PROC_FS
3438         dasd_proc_exit();
3439 #endif
3440         dasd_eer_exit();
3441         kmem_cache_destroy(dasd_page_cache);
3442         dasd_page_cache = NULL;
3443         dasd_gendisk_exit();
3444         dasd_devmap_exit();
3445         if (dasd_debug_area != NULL) {
3446                 debug_unregister(dasd_debug_area);
3447                 dasd_debug_area = NULL;
3448         }
3449         dasd_statistics_removeroot();
3450 }
3451
3452 /*
3453  * SECTION: common functions for ccw_driver use
3454  */
3455
3456 /*
3457  * Is the device read-only?
3458  * Note that this function does not report the setting of the
3459  * readonly device attribute, but how it is configured in z/VM.
3460  */
3461 int dasd_device_is_ro(struct dasd_device *device)
3462 {
3463         struct ccw_dev_id dev_id;
3464         struct diag210 diag_data;
3465         int rc;
3466
3467         if (!MACHINE_IS_VM)
3468                 return 0;
3469         ccw_device_get_id(device->cdev, &dev_id);
3470         memset(&diag_data, 0, sizeof(diag_data));
3471         diag_data.vrdcdvno = dev_id.devno;
3472         diag_data.vrdclen = sizeof(diag_data);
3473         rc = diag210(&diag_data);
3474         if (rc == 0 || rc == 2) {
3475                 return diag_data.vrdcvfla & 0x80;
3476         } else {
3477                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3478                           dev_id.devno, rc);
3479                 return 0;
3480         }
3481 }
3482 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3483
3484 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3485 {
3486         struct ccw_device *cdev = data;
3487         int ret;
3488
3489         ret = ccw_device_set_online(cdev);
3490         if (ret)
3491                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3492                         dev_name(&cdev->dev), ret);
3493 }
3494
3495 /*
3496  * Initial attempt at a probe function. this can be simplified once
3497  * the other detection code is gone.
3498  */
3499 int dasd_generic_probe(struct ccw_device *cdev,
3500                        struct dasd_discipline *discipline)
3501 {
3502         int ret;
3503
3504         ret = dasd_add_sysfs_files(cdev);
3505         if (ret) {
3506                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3507                                 "dasd_generic_probe: could not add "
3508                                 "sysfs entries");
3509                 return ret;
3510         }
3511         cdev->handler = &dasd_int_handler;
3512
3513         /*
3514          * Automatically online either all dasd devices (dasd_autodetect)
3515          * or all devices specified with dasd= parameters during
3516          * initial probe.
3517          */
3518         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3519             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3520                 async_schedule(dasd_generic_auto_online, cdev);
3521         return 0;
3522 }
3523 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3524
3525 void dasd_generic_free_discipline(struct dasd_device *device)
3526 {
3527         /* Forget the discipline information. */
3528         if (device->discipline) {
3529                 if (device->discipline->uncheck_device)
3530                         device->discipline->uncheck_device(device);
3531                 module_put(device->discipline->owner);
3532                 device->discipline = NULL;
3533         }
3534         if (device->base_discipline) {
3535                 module_put(device->base_discipline->owner);
3536                 device->base_discipline = NULL;
3537         }
3538 }
3539 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3540
3541 /*
3542  * This will one day be called from a global not_oper handler.
3543  * It is also used by driver_unregister during module unload.
3544  */
3545 void dasd_generic_remove(struct ccw_device *cdev)
3546 {
3547         struct dasd_device *device;
3548         struct dasd_block *block;
3549
3550         device = dasd_device_from_cdev(cdev);
3551         if (IS_ERR(device)) {
3552                 dasd_remove_sysfs_files(cdev);
3553                 return;
3554         }
3555         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3556             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3557                 /* Already doing offline processing */
3558                 dasd_put_device(device);
3559                 dasd_remove_sysfs_files(cdev);
3560                 return;
3561         }
3562         /*
3563          * This device is removed unconditionally. Set offline
3564          * flag to prevent dasd_open from opening it while it is
3565          * no quite down yet.
3566          */
3567         dasd_set_target_state(device, DASD_STATE_NEW);
3568         cdev->handler = NULL;
3569         /* dasd_delete_device destroys the device reference. */
3570         block = device->block;
3571         dasd_delete_device(device);
3572         /*
3573          * life cycle of block is bound to device, so delete it after
3574          * device was safely removed
3575          */
3576         if (block)
3577                 dasd_free_block(block);
3578
3579         dasd_remove_sysfs_files(cdev);
3580 }
3581 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3582
3583 /*
3584  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3585  * the device is detected for the first time and is supposed to be used
3586  * or the user has started activation through sysfs.
3587  */
3588 int dasd_generic_set_online(struct ccw_device *cdev,
3589                             struct dasd_discipline *base_discipline)
3590 {
3591         struct dasd_discipline *discipline;
3592         struct dasd_device *device;
3593         int rc;
3594
3595         /* first online clears initial online feature flag */
3596         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3597         device = dasd_create_device(cdev);
3598         if (IS_ERR(device))
3599                 return PTR_ERR(device);
3600
3601         discipline = base_discipline;
3602         if (device->features & DASD_FEATURE_USEDIAG) {
3603                 if (!dasd_diag_discipline_pointer) {
3604                         /* Try to load the required module. */
3605                         rc = request_module(DASD_DIAG_MOD);
3606                         if (rc) {
3607                                 pr_warn("%s Setting the DASD online failed "
3608                                         "because the required module %s "
3609                                         "could not be loaded (rc=%d)\n",
3610                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3611                                         rc);
3612                                 dasd_delete_device(device);
3613                                 return -ENODEV;
3614                         }
3615                 }
3616                 /* Module init could have failed, so check again here after
3617                  * request_module(). */
3618                 if (!dasd_diag_discipline_pointer) {
3619                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3620                                 dev_name(&cdev->dev));
3621                         dasd_delete_device(device);
3622                         return -ENODEV;
3623                 }
3624                 discipline = dasd_diag_discipline_pointer;
3625         }
3626         if (!try_module_get(base_discipline->owner)) {
3627                 dasd_delete_device(device);
3628                 return -EINVAL;
3629         }
3630         if (!try_module_get(discipline->owner)) {
3631                 module_put(base_discipline->owner);
3632                 dasd_delete_device(device);
3633                 return -EINVAL;
3634         }
3635         device->base_discipline = base_discipline;
3636         device->discipline = discipline;
3637
3638         /* check_device will allocate block device if necessary */
3639         rc = discipline->check_device(device);
3640         if (rc) {
3641                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3642                         dev_name(&cdev->dev), discipline->name, rc);
3643                 module_put(discipline->owner);
3644                 module_put(base_discipline->owner);
3645                 dasd_delete_device(device);
3646                 return rc;
3647         }
3648
3649         dasd_set_target_state(device, DASD_STATE_ONLINE);
3650         if (device->state <= DASD_STATE_KNOWN) {
3651                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3652                         dev_name(&cdev->dev));
3653                 rc = -ENODEV;
3654                 dasd_set_target_state(device, DASD_STATE_NEW);
3655                 if (device->block)
3656                         dasd_free_block(device->block);
3657                 dasd_delete_device(device);
3658         } else
3659                 pr_debug("dasd_generic device %s found\n",
3660                                 dev_name(&cdev->dev));
3661
3662         wait_event(dasd_init_waitq, _wait_for_device(device));
3663
3664         dasd_put_device(device);
3665         return rc;
3666 }
3667 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3668
3669 int dasd_generic_set_offline(struct ccw_device *cdev)
3670 {
3671         struct dasd_device *device;
3672         struct dasd_block *block;
3673         int max_count, open_count, rc;
3674         unsigned long flags;
3675
3676         rc = 0;
3677         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3678         device = dasd_device_from_cdev_locked(cdev);
3679         if (IS_ERR(device)) {
3680                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3681                 return PTR_ERR(device);
3682         }
3683
3684         /*
3685          * We must make sure that this device is currently not in use.
3686          * The open_count is increased for every opener, that includes
3687          * the blkdev_get in dasd_scan_partitions. We are only interested
3688          * in the other openers.
3689          */
3690         if (device->block) {
3691                 max_count = device->block->bdev ? 0 : -1;
3692                 open_count = atomic_read(&device->block->open_count);
3693                 if (open_count > max_count) {
3694                         if (open_count > 0)
3695                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3696                                         dev_name(&cdev->dev), open_count);
3697                         else
3698                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3699                                         dev_name(&cdev->dev));
3700                         rc = -EBUSY;
3701                         goto out_err;
3702                 }
3703         }
3704
3705         /*
3706          * Test if the offline processing is already running and exit if so.
3707          * If a safe offline is being processed this could only be a normal
3708          * offline that should be able to overtake the safe offline and
3709          * cancel any I/O we do not want to wait for any longer
3710          */
3711         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3712                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3713                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3714                                   &device->flags);
3715                 } else {
3716                         rc = -EBUSY;
3717                         goto out_err;
3718                 }
3719         }
3720         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3721
3722         /*
3723          * if safe_offline is called set safe_offline_running flag and
3724          * clear safe_offline so that a call to normal offline
3725          * can overrun safe_offline processing
3726          */
3727         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3728             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3729                 /* need to unlock here to wait for outstanding I/O */
3730                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3731                 /*
3732                  * If we want to set the device safe offline all IO operations
3733                  * should be finished before continuing the offline process
3734                  * so sync bdev first and then wait for our queues to become
3735                  * empty
3736                  */
3737                 if (device->block) {
3738                         rc = fsync_bdev(device->block->bdev);
3739                         if (rc != 0)
3740                                 goto interrupted;
3741                 }
3742                 dasd_schedule_device_bh(device);
3743                 rc = wait_event_interruptible(shutdown_waitq,
3744                                               _wait_for_empty_queues(device));
3745                 if (rc != 0)
3746                         goto interrupted;
3747
3748                 /*
3749                  * check if a normal offline process overtook the offline
3750                  * processing in this case simply do nothing beside returning
3751                  * that we got interrupted
3752                  * otherwise mark safe offline as not running any longer and
3753                  * continue with normal offline
3754                  */
3755                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3756                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3757                         rc = -ERESTARTSYS;
3758                         goto out_err;
3759                 }
3760                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3761         }
3762         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3763
3764         dasd_set_target_state(device, DASD_STATE_NEW);
3765         /* dasd_delete_device destroys the device reference. */
3766         block = device->block;
3767         dasd_delete_device(device);
3768         /*
3769          * life cycle of block is bound to device, so delete it after
3770          * device was safely removed
3771          */
3772         if (block)
3773                 dasd_free_block(block);
3774
3775         return 0;
3776
3777 interrupted:
3778         /* interrupted by signal */
3779         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3780         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3781         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3782 out_err:
3783         dasd_put_device(device);
3784         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3785         return rc;
3786 }
3787 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3788
3789 int dasd_generic_last_path_gone(struct dasd_device *device)
3790 {
3791         struct dasd_ccw_req *cqr;
3792
3793         dev_warn(&device->cdev->dev, "No operational channel path is left "
3794                  "for the device\n");
3795         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3796         /* First of all call extended error reporting. */
3797         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3798
3799         if (device->state < DASD_STATE_BASIC)
3800                 return 0;
3801         /* Device is active. We want to keep it. */
3802         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3803                 if ((cqr->status == DASD_CQR_IN_IO) ||
3804                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3805                         cqr->status = DASD_CQR_QUEUED;
3806                         cqr->retries++;
3807                 }
3808         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3809         dasd_device_clear_timer(device);
3810         dasd_schedule_device_bh(device);
3811         return 1;
3812 }
3813 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3814
3815 int dasd_generic_path_operational(struct dasd_device *device)
3816 {
3817         dev_info(&device->cdev->dev, "A channel path to the device has become "
3818                  "operational\n");
3819         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3820         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3821         if (device->stopped & DASD_UNRESUMED_PM) {
3822                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3823                 dasd_restore_device(device);
3824                 return 1;
3825         }
3826         dasd_schedule_device_bh(device);
3827         if (device->block) {
3828                 dasd_schedule_block_bh(device->block);
3829                 if (device->block->request_queue)
3830                         blk_mq_run_hw_queues(device->block->request_queue,
3831                                              true);
3832                 }
3833
3834         if (!device->stopped)
3835                 wake_up(&generic_waitq);
3836
3837         return 1;
3838 }
3839 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3840
3841 int dasd_generic_notify(struct ccw_device *cdev, int event)
3842 {
3843         struct dasd_device *device;
3844         int ret;
3845
3846         device = dasd_device_from_cdev_locked(cdev);
3847         if (IS_ERR(device))
3848                 return 0;
3849         ret = 0;
3850         switch (event) {
3851         case CIO_GONE:
3852         case CIO_BOXED:
3853         case CIO_NO_PATH:
3854                 dasd_path_no_path(device);
3855                 ret = dasd_generic_last_path_gone(device);
3856                 break;
3857         case CIO_OPER:
3858                 ret = 1;
3859                 if (dasd_path_get_opm(device))
3860                         ret = dasd_generic_path_operational(device);
3861                 break;
3862         }
3863         dasd_put_device(device);
3864         return ret;
3865 }
3866 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3867
3868 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3869 {
3870         struct dasd_device *device;
3871         int chp, oldopm, hpfpm, ifccpm;
3872
3873         device = dasd_device_from_cdev_locked(cdev);
3874         if (IS_ERR(device))
3875                 return;
3876
3877         oldopm = dasd_path_get_opm(device);
3878         for (chp = 0; chp < 8; chp++) {
3879                 if (path_event[chp] & PE_PATH_GONE) {
3880                         dasd_path_notoper(device, chp);
3881                 }
3882                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3883                         dasd_path_available(device, chp);
3884                         dasd_schedule_device_bh(device);
3885                 }
3886                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3887                         if (!dasd_path_is_operational(device, chp) &&
3888                             !dasd_path_need_verify(device, chp)) {
3889                                 /*
3890                                  * we can not establish a pathgroup on an
3891                                  * unavailable path, so trigger a path
3892                                  * verification first
3893                                  */
3894                         dasd_path_available(device, chp);
3895                         dasd_schedule_device_bh(device);
3896                         }
3897                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3898                                       "Pathgroup re-established\n");
3899                         if (device->discipline->kick_validate)
3900                                 device->discipline->kick_validate(device);
3901                 }
3902         }
3903         hpfpm = dasd_path_get_hpfpm(device);
3904         ifccpm = dasd_path_get_ifccpm(device);
3905         if (!dasd_path_get_opm(device) && hpfpm) {
3906                 /*
3907                  * device has no operational paths but at least one path is
3908                  * disabled due to HPF errors
3909                  * disable HPF at all and use the path(s) again
3910                  */
3911                 if (device->discipline->disable_hpf)
3912                         device->discipline->disable_hpf(device);
3913                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3914                 dasd_path_set_tbvpm(device, hpfpm);
3915                 dasd_schedule_device_bh(device);
3916                 dasd_schedule_requeue(device);
3917         } else if (!dasd_path_get_opm(device) && ifccpm) {
3918                 /*
3919                  * device has no operational paths but at least one path is
3920                  * disabled due to IFCC errors
3921                  * trigger path verification on paths with IFCC errors
3922                  */
3923                 dasd_path_set_tbvpm(device, ifccpm);
3924                 dasd_schedule_device_bh(device);
3925         }
3926         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3927                 dev_warn(&device->cdev->dev,
3928                          "No verified channel paths remain for the device\n");
3929                 DBF_DEV_EVENT(DBF_WARNING, device,
3930                               "%s", "last verified path gone");
3931                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3932                 dasd_device_set_stop_bits(device,
3933                                           DASD_STOPPED_DC_WAIT);
3934         }
3935         dasd_put_device(device);
3936 }
3937 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3938
3939 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3940 {
3941         if (!dasd_path_get_opm(device) && lpm) {
3942                 dasd_path_set_opm(device, lpm);
3943                 dasd_generic_path_operational(device);
3944         } else
3945                 dasd_path_add_opm(device, lpm);
3946         return 0;
3947 }
3948 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3949
3950 void dasd_generic_space_exhaust(struct dasd_device *device,
3951                                 struct dasd_ccw_req *cqr)
3952 {
3953         dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3954
3955         if (device->state < DASD_STATE_BASIC)
3956                 return;
3957
3958         if (cqr->status == DASD_CQR_IN_IO ||
3959             cqr->status == DASD_CQR_CLEAR_PENDING) {
3960                 cqr->status = DASD_CQR_QUEUED;
3961                 cqr->retries++;
3962         }
3963         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3964         dasd_device_clear_timer(device);
3965         dasd_schedule_device_bh(device);
3966 }
3967 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3968
3969 void dasd_generic_space_avail(struct dasd_device *device)
3970 {
3971         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3972         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3973
3974         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3975         dasd_schedule_device_bh(device);
3976
3977         if (device->block) {
3978                 dasd_schedule_block_bh(device->block);
3979                 if (device->block->request_queue)
3980                         blk_mq_run_hw_queues(device->block->request_queue, true);
3981         }
3982         if (!device->stopped)
3983                 wake_up(&generic_waitq);
3984 }
3985 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3986
3987 /*
3988  * clear active requests and requeue them to block layer if possible
3989  */
3990 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3991 {
3992         struct dasd_block *block = device->block;
3993         struct list_head requeue_queue;
3994         struct dasd_ccw_req *cqr, *n;
3995         int rc;
3996
3997         if (!block)
3998                 return 0;
3999
4000         INIT_LIST_HEAD(&requeue_queue);
4001         rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
4002
4003         /* Now call the callback function of flushed requests */
4004 restart_cb:
4005         list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
4006                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
4007                 /* Process finished ERP request. */
4008                 if (cqr->refers) {
4009                         spin_lock_bh(&block->queue_lock);
4010                         __dasd_process_erp(block->base, cqr);
4011                         spin_unlock_bh(&block->queue_lock);
4012                         /* restart list_for_xx loop since dasd_process_erp
4013                          * might remove multiple elements
4014                          */
4015                         goto restart_cb;
4016                 }
4017                 _dasd_requeue_request(cqr);
4018                 list_del_init(&cqr->blocklist);
4019                 cqr->block->base->discipline->free_cp(
4020                         cqr, (struct request *) cqr->callback_data);
4021         }
4022         dasd_schedule_device_bh(device);
4023         return rc;
4024 }
4025
4026 static void do_requeue_requests(struct work_struct *work)
4027 {
4028         struct dasd_device *device = container_of(work, struct dasd_device,
4029                                                   requeue_requests);
4030         dasd_generic_requeue_all_requests(device);
4031         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
4032         if (device->block)
4033                 dasd_schedule_block_bh(device->block);
4034         dasd_put_device(device);
4035 }
4036
4037 void dasd_schedule_requeue(struct dasd_device *device)
4038 {
4039         dasd_get_device(device);
4040         /* queue call to dasd_reload_device to the kernel event daemon. */
4041         if (!schedule_work(&device->requeue_requests))
4042                 dasd_put_device(device);
4043 }
4044 EXPORT_SYMBOL(dasd_schedule_requeue);
4045
4046 int dasd_generic_pm_freeze(struct ccw_device *cdev)
4047 {
4048         struct dasd_device *device = dasd_device_from_cdev(cdev);
4049
4050         if (IS_ERR(device))
4051                 return PTR_ERR(device);
4052
4053         /* mark device as suspended */
4054         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
4055
4056         if (device->discipline->freeze)
4057                 device->discipline->freeze(device);
4058
4059         /* disallow new I/O  */
4060         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
4061
4062         return dasd_generic_requeue_all_requests(device);
4063 }
4064 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
4065
4066 int dasd_generic_restore_device(struct ccw_device *cdev)
4067 {
4068         struct dasd_device *device = dasd_device_from_cdev(cdev);
4069         int rc = 0;
4070
4071         if (IS_ERR(device))
4072                 return PTR_ERR(device);
4073
4074         /* allow new IO again */
4075         dasd_device_remove_stop_bits(device,
4076                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4077
4078         dasd_schedule_device_bh(device);
4079
4080         /*
4081          * call discipline restore function
4082          * if device is stopped do nothing e.g. for disconnected devices
4083          */
4084         if (device->discipline->restore && !(device->stopped))
4085                 rc = device->discipline->restore(device);
4086         if (rc || device->stopped)
4087                 /*
4088                  * if the resume failed for the DASD we put it in
4089                  * an UNRESUMED stop state
4090                  */
4091                 device->stopped |= DASD_UNRESUMED_PM;
4092
4093         if (device->block) {
4094                 dasd_schedule_block_bh(device->block);
4095                 if (device->block->request_queue)
4096                         blk_mq_run_hw_queues(device->block->request_queue,
4097                                              true);
4098         }
4099
4100         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4101         dasd_put_device(device);
4102         return 0;
4103 }
4104 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4105
4106 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4107                                                    int rdc_buffer_size,
4108                                                    int magic)
4109 {
4110         struct dasd_ccw_req *cqr;
4111         struct ccw1 *ccw;
4112
4113         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
4114                                    NULL);
4115
4116         if (IS_ERR(cqr)) {
4117                 /* internal error 13 - Allocating the RDC request failed*/
4118                 dev_err(&device->cdev->dev,
4119                          "An error occurred in the DASD device driver, "
4120                          "reason=%s\n", "13");
4121                 return cqr;
4122         }
4123
4124         ccw = cqr->cpaddr;
4125         ccw->cmd_code = CCW_CMD_RDC;
4126         ccw->cda = (__u32)(addr_t) cqr->data;
4127         ccw->flags = 0;
4128         ccw->count = rdc_buffer_size;
4129         cqr->startdev = device;
4130         cqr->memdev = device;
4131         cqr->expires = 10*HZ;
4132         cqr->retries = 256;
4133         cqr->buildclk = get_tod_clock();
4134         cqr->status = DASD_CQR_FILLED;
4135         return cqr;
4136 }
4137
4138
4139 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4140                                 void *rdc_buffer, int rdc_buffer_size)
4141 {
4142         int ret;
4143         struct dasd_ccw_req *cqr;
4144
4145         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4146         if (IS_ERR(cqr))
4147                 return PTR_ERR(cqr);
4148
4149         ret = dasd_sleep_on(cqr);
4150         if (ret == 0)
4151                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4152         dasd_sfree_request(cqr, cqr->memdev);
4153         return ret;
4154 }
4155 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4156
4157 /*
4158  *   In command mode and transport mode we need to look for sense
4159  *   data in different places. The sense data itself is allways
4160  *   an array of 32 bytes, so we can unify the sense data access
4161  *   for both modes.
4162  */
4163 char *dasd_get_sense(struct irb *irb)
4164 {
4165         struct tsb *tsb = NULL;
4166         char *sense = NULL;
4167
4168         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4169                 if (irb->scsw.tm.tcw)
4170                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4171                                           irb->scsw.tm.tcw);
4172                 if (tsb && tsb->length == 64 && tsb->flags)
4173                         switch (tsb->flags & 0x07) {
4174                         case 1: /* tsa_iostat */
4175                                 sense = tsb->tsa.iostat.sense;
4176                                 break;
4177                         case 2: /* tsa_ddpc */
4178                                 sense = tsb->tsa.ddpc.sense;
4179                                 break;
4180                         default:
4181                                 /* currently we don't use interrogate data */
4182                                 break;
4183                         }
4184         } else if (irb->esw.esw0.erw.cons) {
4185                 sense = irb->ecw;
4186         }
4187         return sense;
4188 }
4189 EXPORT_SYMBOL_GPL(dasd_get_sense);
4190
4191 void dasd_generic_shutdown(struct ccw_device *cdev)
4192 {
4193         struct dasd_device *device;
4194
4195         device = dasd_device_from_cdev(cdev);
4196         if (IS_ERR(device))
4197                 return;
4198
4199         if (device->block)
4200                 dasd_schedule_block_bh(device->block);
4201
4202         dasd_schedule_device_bh(device);
4203
4204         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4205 }
4206 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4207
4208 static int __init dasd_init(void)
4209 {
4210         int rc;
4211
4212         init_waitqueue_head(&dasd_init_waitq);
4213         init_waitqueue_head(&dasd_flush_wq);
4214         init_waitqueue_head(&generic_waitq);
4215         init_waitqueue_head(&shutdown_waitq);
4216
4217         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4218         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4219         if (dasd_debug_area == NULL) {
4220                 rc = -ENOMEM;
4221                 goto failed;
4222         }
4223         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4224         debug_set_level(dasd_debug_area, DBF_WARNING);
4225
4226         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4227
4228         dasd_diag_discipline_pointer = NULL;
4229
4230         dasd_statistics_createroot();
4231
4232         rc = dasd_devmap_init();
4233         if (rc)
4234                 goto failed;
4235         rc = dasd_gendisk_init();
4236         if (rc)
4237                 goto failed;
4238         rc = dasd_parse();
4239         if (rc)
4240                 goto failed;
4241         rc = dasd_eer_init();
4242         if (rc)
4243                 goto failed;
4244 #ifdef CONFIG_PROC_FS
4245         rc = dasd_proc_init();
4246         if (rc)
4247                 goto failed;
4248 #endif
4249
4250         return 0;
4251 failed:
4252         pr_info("The DASD device driver could not be initialized\n");
4253         dasd_exit();
4254         return rc;
4255 }
4256
4257 module_init(dasd_init);
4258 module_exit(dasd_exit);