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                 counter = 1; /* request is not yet queued on the start device */
 742                 list_for_each(l, &device->ccw_queue)
 743                         if (++counter >= 31)
 744                                 break;
 745         }
 746         spin_lock(&device->profile.lock);
 747         if (device->profile.data) {
 748                 device->profile.data->dasd_io_nr_req[counter]++;
 749                 if (rq_data_dir(req) == READ)
 750                         device->profile.data->dasd_read_nr_req[counter]++;
 751         }
 752         spin_unlock(&device->profile.lock);
 753 }
 754
 755 /*
 756  * Add profiling information for cqr after execution.
 757  */
 758
 759 #define dasd_profile_counter(value, index)                         \
 760 {                                                                  \
 761         for (index = 0; index < 31 && value >> (2+index); index++) \
 762                 ;                                                  \
 763 }
 764
 765 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 766                                       int is_alias,
 767                                       int is_tpm,
 768                                       int is_read,
 769                                       long sectors,
 770                                       int sectors_ind,
 771                                       int tottime_ind,
 772                                       int tottimeps_ind,
 773                                       int strtime_ind,
 774                                       int irqtime_ind,
 775                                       int irqtimeps_ind,
 776                                       int endtime_ind)
 777 {
 778         /* in case of an overflow, reset the whole profile */
 779         if (data->dasd_io_reqs == UINT_MAX) {
 780                         memset(data, 0, sizeof(*data));
 781                         ktime_get_real_ts64(&data->starttod);
 782         }
 783         data->dasd_io_reqs++;
 784         data->dasd_io_sects += sectors;
 785         if (is_alias)
 786                 data->dasd_io_alias++;
 787         if (is_tpm)
 788                 data->dasd_io_tpm++;
 789
 790         data->dasd_io_secs[sectors_ind]++;
 791         data->dasd_io_times[tottime_ind]++;
 792         data->dasd_io_timps[tottimeps_ind]++;
 793         data->dasd_io_time1[strtime_ind]++;
 794         data->dasd_io_time2[irqtime_ind]++;
 795         data->dasd_io_time2ps[irqtimeps_ind]++;
 796         data->dasd_io_time3[endtime_ind]++;
 797
 798         if (is_read) {
 799                 data->dasd_read_reqs++;
 800                 data->dasd_read_sects += sectors;
 801                 if (is_alias)
 802                         data->dasd_read_alias++;
 803                 if (is_tpm)
 804                         data->dasd_read_tpm++;
 805                 data->dasd_read_secs[sectors_ind]++;
 806                 data->dasd_read_times[tottime_ind]++;
 807                 data->dasd_read_time1[strtime_ind]++;
 808                 data->dasd_read_time2[irqtime_ind]++;
 809                 data->dasd_read_time3[endtime_ind]++;
 810         }
 811 }
 812
 813 static void dasd_profile_end(struct dasd_block *block,
 814                              struct dasd_ccw_req *cqr,
 815                              struct request *req)
 816 {
 817         unsigned long strtime, irqtime, endtime, tottime;
 818         unsigned long tottimeps, sectors;
 819         struct dasd_device *device;
 820         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 821         int irqtime_ind, irqtimeps_ind, endtime_ind;
 822         struct dasd_profile_info *data;
 823
 824         device = cqr->startdev;
 825         if (!(dasd_global_profile_level ||
 826               block->profile.data ||
 827               device->profile.data))
 828                 return;
 829
 830         sectors = blk_rq_sectors(req);
 831         if (!cqr->buildclk || !cqr->startclk ||
 832             !cqr->stopclk || !cqr->endclk ||
 833             !sectors)
 834                 return;
 835
 836         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 837         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 838         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 839         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 840         tottimeps = tottime / sectors;
 841
 842         dasd_profile_counter(sectors, sectors_ind);
 843         dasd_profile_counter(tottime, tottime_ind);
 844         dasd_profile_counter(tottimeps, tottimeps_ind);
 845         dasd_profile_counter(strtime, strtime_ind);
 846         dasd_profile_counter(irqtime, irqtime_ind);
 847         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 848         dasd_profile_counter(endtime, endtime_ind);
 849
 850         spin_lock(&dasd_global_profile.lock);
 851         if (dasd_global_profile.data) {
 852                 data = dasd_global_profile.data;
 853                 data->dasd_sum_times += tottime;
 854                 data->dasd_sum_time_str += strtime;
 855                 data->dasd_sum_time_irq += irqtime;
 856                 data->dasd_sum_time_end += endtime;
 857                 dasd_profile_end_add_data(dasd_global_profile.data,
 858                                           cqr->startdev != block->base,
 859                                           cqr->cpmode == 1,
 860                                           rq_data_dir(req) == READ,
 861                                           sectors, sectors_ind, tottime_ind,
 862                                           tottimeps_ind, strtime_ind,
 863                                           irqtime_ind, irqtimeps_ind,
 864                                           endtime_ind);
 865         }
 866         spin_unlock(&dasd_global_profile.lock);
 867
 868         spin_lock(&block->profile.lock);
 869         if (block->profile.data) {
 870                 data = block->profile.data;
 871                 data->dasd_sum_times += tottime;
 872                 data->dasd_sum_time_str += strtime;
 873                 data->dasd_sum_time_irq += irqtime;
 874                 data->dasd_sum_time_end += endtime;
 875                 dasd_profile_end_add_data(block->profile.data,
 876                                           cqr->startdev != block->base,
 877                                           cqr->cpmode == 1,
 878                                           rq_data_dir(req) == READ,
 879                                           sectors, sectors_ind, tottime_ind,
 880                                           tottimeps_ind, strtime_ind,
 881                                           irqtime_ind, irqtimeps_ind,
 882                                           endtime_ind);
 883         }
 884         spin_unlock(&block->profile.lock);
 885
 886         spin_lock(&device->profile.lock);
 887         if (device->profile.data) {
 888                 data = device->profile.data;
 889                 data->dasd_sum_times += tottime;
 890                 data->dasd_sum_time_str += strtime;
 891                 data->dasd_sum_time_irq += irqtime;
 892                 data->dasd_sum_time_end += endtime;
 893                 dasd_profile_end_add_data(device->profile.data,
 894                                           cqr->startdev != block->base,
 895                                           cqr->cpmode == 1,
 896                                           rq_data_dir(req) == READ,
 897                                           sectors, sectors_ind, tottime_ind,
 898                                           tottimeps_ind, strtime_ind,
 899                                           irqtime_ind, irqtimeps_ind,
 900                                           endtime_ind);
 901         }
 902         spin_unlock(&device->profile.lock);
 903 }
 904
 905 void dasd_profile_reset(struct dasd_profile *profile)
 906 {
 907         struct dasd_profile_info *data;
 908
 909         spin_lock_bh(&profile->lock);
 910         data = profile->data;
 911         if (!data) {
 912                 spin_unlock_bh(&profile->lock);
 913                 return;
 914         }
 915         memset(data, 0, sizeof(*data));
 916         ktime_get_real_ts64(&data->starttod);
 917         spin_unlock_bh(&profile->lock);
 918 }
 919
 920 int dasd_profile_on(struct dasd_profile *profile)
 921 {
 922         struct dasd_profile_info *data;
 923
 924         data = kzalloc(sizeof(*data), GFP_KERNEL);
 925         if (!data)
 926                 return -ENOMEM;
 927         spin_lock_bh(&profile->lock);
 928         if (profile->data) {
 929                 spin_unlock_bh(&profile->lock);
 930                 kfree(data);
 931                 return 0;
 932         }
 933         ktime_get_real_ts64(&data->starttod);
 934         profile->data = data;
 935         spin_unlock_bh(&profile->lock);
 936         return 0;
 937 }
 938
 939 void dasd_profile_off(struct dasd_profile *profile)
 940 {
 941         spin_lock_bh(&profile->lock);
 942         kfree(profile->data);
 943         profile->data = NULL;
 944         spin_unlock_bh(&profile->lock);
 945 }
 946
 947 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 948 {
 949         char *buffer;
 950
 951         buffer = vmalloc(user_len + 1);
 952         if (buffer == NULL)
 953                 return ERR_PTR(-ENOMEM);
 954         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 955                 vfree(buffer);
 956                 return ERR_PTR(-EFAULT);
 957         }
 958         /* got the string, now strip linefeed. */
 959         if (buffer[user_len - 1] == '\n')
 960                 buffer[user_len - 1] = 0;
 961         else
 962                 buffer[user_len] = 0;
 963         return buffer;
 964 }
 965
 966 static ssize_t dasd_stats_write(struct file *file,
 967                                 const char __user *user_buf,
 968                                 size_t user_len, loff_t *pos)
 969 {
 970         char *buffer, *str;
 971         int rc;
 972         struct seq_file *m = (struct seq_file *)file->private_data;
 973         struct dasd_profile *prof = m->private;
 974
 975         if (user_len > 65536)
 976                 user_len = 65536;
 977         buffer = dasd_get_user_string(user_buf, user_len);
 978         if (IS_ERR(buffer))
 979                 return PTR_ERR(buffer);
 980
 981         str = skip_spaces(buffer);
 982         rc = user_len;
 983         if (strncmp(str, "reset", 5) == 0) {
 984                 dasd_profile_reset(prof);
 985         } else if (strncmp(str, "on", 2) == 0) {
 986                 rc = dasd_profile_on(prof);
 987                 if (rc)
 988                         goto out;
 989                 rc = user_len;
 990                 if (prof == &dasd_global_profile) {
 991                         dasd_profile_reset(prof);
 992                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 993                 }
 994         } else if (strncmp(str, "off", 3) == 0) {
 995                 if (prof == &dasd_global_profile)
 996                         dasd_global_profile_level = DASD_PROFILE_OFF;
 997                 dasd_profile_off(prof);
 998         } else
 999                 rc = -EINVAL;
1000 out:
1001         vfree(buffer);
1002         return rc;
1003 }
1004
1005 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
1006 {
1007         int i;
1008
1009         for (i = 0; i < 32; i++)
1010                 seq_printf(m, "%u ", array[i]);
1011         seq_putc(m, '\n');
1012 }
1013
1014 static void dasd_stats_seq_print(struct seq_file *m,
1015                                  struct dasd_profile_info *data)
1016 {
1017         seq_printf(m, "start_time %lld.%09ld\n",
1018                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1019         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1020         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1021         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1022         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1023         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1024                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1025         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1026                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1027         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1028                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1029         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1030                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1031         seq_puts(m, "histogram_sectors ");
1032         dasd_stats_array(m, data->dasd_io_secs);
1033         seq_puts(m, "histogram_io_times ");
1034         dasd_stats_array(m, data->dasd_io_times);
1035         seq_puts(m, "histogram_io_times_weighted ");
1036         dasd_stats_array(m, data->dasd_io_timps);
1037         seq_puts(m, "histogram_time_build_to_ssch ");
1038         dasd_stats_array(m, data->dasd_io_time1);
1039         seq_puts(m, "histogram_time_ssch_to_irq ");
1040         dasd_stats_array(m, data->dasd_io_time2);
1041         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1042         dasd_stats_array(m, data->dasd_io_time2ps);
1043         seq_puts(m, "histogram_time_irq_to_end ");
1044         dasd_stats_array(m, data->dasd_io_time3);
1045         seq_puts(m, "histogram_ccw_queue_length ");
1046         dasd_stats_array(m, data->dasd_io_nr_req);
1047         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1048         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1049         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1050         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1051         seq_puts(m, "histogram_read_sectors ");
1052         dasd_stats_array(m, data->dasd_read_secs);
1053         seq_puts(m, "histogram_read_times ");
1054         dasd_stats_array(m, data->dasd_read_times);
1055         seq_puts(m, "histogram_read_time_build_to_ssch ");
1056         dasd_stats_array(m, data->dasd_read_time1);
1057         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1058         dasd_stats_array(m, data->dasd_read_time2);
1059         seq_puts(m, "histogram_read_time_irq_to_end ");
1060         dasd_stats_array(m, data->dasd_read_time3);
1061         seq_puts(m, "histogram_read_ccw_queue_length ");
1062         dasd_stats_array(m, data->dasd_read_nr_req);
1063 }
1064
1065 static int dasd_stats_show(struct seq_file *m, void *v)
1066 {
1067         struct dasd_profile *profile;
1068         struct dasd_profile_info *data;
1069
1070         profile = m->private;
1071         spin_lock_bh(&profile->lock);
1072         data = profile->data;
1073         if (!data) {
1074                 spin_unlock_bh(&profile->lock);
1075                 seq_puts(m, "disabled\n");
1076                 return 0;
1077         }
1078         dasd_stats_seq_print(m, data);
1079         spin_unlock_bh(&profile->lock);
1080         return 0;
1081 }
1082
1083 static int dasd_stats_open(struct inode *inode, struct file *file)
1084 {
1085         struct dasd_profile *profile = inode->i_private;
1086         return single_open(file, dasd_stats_show, profile);
1087 }
1088
1089 static const struct file_operations dasd_stats_raw_fops = {
1090         .owner          = THIS_MODULE,
1091         .open           = dasd_stats_open,
1092         .read           = seq_read,
1093         .llseek         = seq_lseek,
1094         .release        = single_release,
1095         .write          = dasd_stats_write,
1096 };
1097
1098 static void dasd_profile_init(struct dasd_profile *profile,
1099                               struct dentry *base_dentry)
1100 {
1101         umode_t mode;
1102         struct dentry *pde;
1103
1104         if (!base_dentry)
1105                 return;
1106         profile->dentry = NULL;
1107         profile->data = NULL;
1108         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1109         pde = debugfs_create_file("statistics", mode, base_dentry,
1110                                   profile, &dasd_stats_raw_fops);
1111         if (pde && !IS_ERR(pde))
1112                 profile->dentry = pde;
1113         return;
1114 }
1115
1116 static void dasd_profile_exit(struct dasd_profile *profile)
1117 {
1118         dasd_profile_off(profile);
1119         debugfs_remove(profile->dentry);
1120         profile->dentry = NULL;
1121 }
1122
1123 static void dasd_statistics_removeroot(void)
1124 {
1125         dasd_global_profile_level = DASD_PROFILE_OFF;
1126         dasd_profile_exit(&dasd_global_profile);
1127         debugfs_remove(dasd_debugfs_global_entry);
1128         debugfs_remove(dasd_debugfs_root_entry);
1129 }
1130
1131 static void dasd_statistics_createroot(void)
1132 {
1133         struct dentry *pde;
1134
1135         dasd_debugfs_root_entry = NULL;
1136         pde = debugfs_create_dir("dasd", NULL);
1137         if (!pde || IS_ERR(pde))
1138                 goto error;
1139         dasd_debugfs_root_entry = pde;
1140         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1141         if (!pde || IS_ERR(pde))
1142                 goto error;
1143         dasd_debugfs_global_entry = pde;
1144         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1145         return;
1146
1147 error:
1148         DBF_EVENT(DBF_ERR, "%s",
1149                   "Creation of the dasd debugfs interface failed");
1150         dasd_statistics_removeroot();
1151         return;
1152 }
1153
1154 #else
1155 #define dasd_profile_start(block, cqr, req) do {} while (0)
1156 #define dasd_profile_end(block, cqr, req) do {} while (0)
1157
1158 static void dasd_statistics_createroot(void)
1159 {
1160         return;
1161 }
1162
1163 static void dasd_statistics_removeroot(void)
1164 {
1165         return;
1166 }
1167
1168 int dasd_stats_generic_show(struct seq_file *m, void *v)
1169 {
1170         seq_puts(m, "Statistics are not activated in this kernel\n");
1171         return 0;
1172 }
1173
1174 static void dasd_profile_init(struct dasd_profile *profile,
1175                               struct dentry *base_dentry)
1176 {
1177         return;
1178 }
1179
1180 static void dasd_profile_exit(struct dasd_profile *profile)
1181 {
1182         return;
1183 }
1184
1185 int dasd_profile_on(struct dasd_profile *profile)
1186 {
1187         return 0;
1188 }
1189
1190 #endif                          /* CONFIG_DASD_PROFILE */
1191
1192 static int dasd_hosts_show(struct seq_file *m, void *v)
1193 {
1194         struct dasd_device *device;
1195         int rc = -EOPNOTSUPP;
1196
1197         device = m->private;
1198         dasd_get_device(device);
1199
1200         if (device->discipline->hosts_print)
1201                 rc = device->discipline->hosts_print(device, m);
1202
1203         dasd_put_device(device);
1204         return rc;
1205 }
1206
1207 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1208
1209 static void dasd_hosts_exit(struct dasd_device *device)
1210 {
1211         debugfs_remove(device->hosts_dentry);
1212         device->hosts_dentry = NULL;
1213 }
1214
1215 static void dasd_hosts_init(struct dentry *base_dentry,
1216                             struct dasd_device *device)
1217 {
1218         struct dentry *pde;
1219         umode_t mode;
1220
1221         if (!base_dentry)
1222                 return;
1223
1224         mode = S_IRUSR | S_IFREG;
1225         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1226                                   device, &dasd_hosts_fops);
1227         if (pde && !IS_ERR(pde))
1228                 device->hosts_dentry = pde;
1229 }
1230
1231 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1232                                           struct dasd_device *device,
1233                                           struct dasd_ccw_req *cqr)
1234 {
1235         unsigned long flags;
1236         char *data, *chunk;
1237         int size = 0;
1238
1239         if (cplength > 0)
1240                 size += cplength * sizeof(struct ccw1);
1241         if (datasize > 0)
1242                 size += datasize;
1243         if (!cqr)
1244                 size += (sizeof(*cqr) + 7L) & -8L;
1245
1246         spin_lock_irqsave(&device->mem_lock, flags);
1247         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1248         spin_unlock_irqrestore(&device->mem_lock, flags);
1249         if (!chunk)
1250                 return ERR_PTR(-ENOMEM);
1251         if (!cqr) {
1252                 cqr = (void *) data;
1253                 data += (sizeof(*cqr) + 7L) & -8L;
1254         }
1255         memset(cqr, 0, sizeof(*cqr));
1256         cqr->mem_chunk = chunk;
1257         if (cplength > 0) {
1258                 cqr->cpaddr = data;
1259                 data += cplength * sizeof(struct ccw1);
1260                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1261         }
1262         if (datasize > 0) {
1263                 cqr->data = data;
1264                 memset(cqr->data, 0, datasize);
1265         }
1266         cqr->magic = magic;
1267         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1268         dasd_get_device(device);
1269         return cqr;
1270 }
1271 EXPORT_SYMBOL(dasd_smalloc_request);
1272
1273 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1274                                           int datasize,
1275                                           struct dasd_device *device)
1276 {
1277         struct dasd_ccw_req *cqr;
1278         unsigned long flags;
1279         int size, cqr_size;
1280         char *data;
1281
1282         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1283         size = cqr_size;
1284         if (cplength > 0)
1285                 size += cplength * sizeof(struct ccw1);
1286         if (datasize > 0)
1287                 size += datasize;
1288
1289         spin_lock_irqsave(&device->mem_lock, flags);
1290         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1291         spin_unlock_irqrestore(&device->mem_lock, flags);
1292         if (!cqr)
1293                 return ERR_PTR(-ENOMEM);
1294         memset(cqr, 0, sizeof(*cqr));
1295         data = (char *)cqr + cqr_size;
1296         cqr->cpaddr = NULL;
1297         if (cplength > 0) {
1298                 cqr->cpaddr = data;
1299                 data += cplength * sizeof(struct ccw1);
1300                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1301         }
1302         cqr->data = NULL;
1303         if (datasize > 0) {
1304                 cqr->data = data;
1305                 memset(cqr->data, 0, datasize);
1306         }
1307
1308         cqr->magic = magic;
1309         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1310         dasd_get_device(device);
1311
1312         return cqr;
1313 }
1314 EXPORT_SYMBOL(dasd_fmalloc_request);
1315
1316 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1317 {
1318         unsigned long flags;
1319
1320         spin_lock_irqsave(&device->mem_lock, flags);
1321         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1322         spin_unlock_irqrestore(&device->mem_lock, flags);
1323         dasd_put_device(device);
1324 }
1325 EXPORT_SYMBOL(dasd_sfree_request);
1326
1327 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1328 {
1329         unsigned long flags;
1330
1331         spin_lock_irqsave(&device->mem_lock, flags);
1332         dasd_free_chunk(&device->ese_chunks, cqr);
1333         spin_unlock_irqrestore(&device->mem_lock, flags);
1334         dasd_put_device(device);
1335 }
1336 EXPORT_SYMBOL(dasd_ffree_request);
1337
1338 /*
1339  * Check discipline magic in cqr.
1340  */
1341 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1342 {
1343         struct dasd_device *device;
1344
1345         if (cqr == NULL)
1346                 return -EINVAL;
1347         device = cqr->startdev;
1348         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1349                 DBF_DEV_EVENT(DBF_WARNING, device,
1350                             " dasd_ccw_req 0x%08x magic doesn't match"
1351                             " discipline 0x%08x",
1352                             cqr->magic,
1353                             *(unsigned int *) device->discipline->name);
1354                 return -EINVAL;
1355         }
1356         return 0;
1357 }
1358
1359 /*
1360  * Terminate the current i/o and set the request to clear_pending.
1361  * Timer keeps device runnig.
1362  * ccw_device_clear can fail if the i/o subsystem
1363  * is in a bad mood.
1364  */
1365 int dasd_term_IO(struct dasd_ccw_req *cqr)
1366 {
1367         struct dasd_device *device;
1368         int retries, rc;
1369         char errorstring[ERRORLENGTH];
1370
1371         /* Check the cqr */
1372         rc = dasd_check_cqr(cqr);
1373         if (rc)
1374                 return rc;
1375         retries = 0;
1376         device = (struct dasd_device *) cqr->startdev;
1377         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1378                 rc = ccw_device_clear(device->cdev, (long) cqr);
1379                 switch (rc) {
1380                 case 0: /* termination successful */
1381                         cqr->status = DASD_CQR_CLEAR_PENDING;
1382                         cqr->stopclk = get_tod_clock();
1383                         cqr->starttime = 0;
1384                         DBF_DEV_EVENT(DBF_DEBUG, device,
1385                                       "terminate cqr %p successful",
1386                                       cqr);
1387                         break;
1388                 case -ENODEV:
1389                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1390                                       "device gone, retry");
1391                         break;
1392                 case -EINVAL:
1393                         /*
1394                          * device not valid so no I/O could be running
1395                          * handle CQR as termination successful
1396                          */
1397                         cqr->status = DASD_CQR_CLEARED;
1398                         cqr->stopclk = get_tod_clock();
1399                         cqr->starttime = 0;
1400                         /* no retries for invalid devices */
1401                         cqr->retries = -1;
1402                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1403                                       "EINVAL, handle as terminated");
1404                         /* fake rc to success */
1405                         rc = 0;
1406                         break;
1407                 default:
1408                         /* internal error 10 - unknown rc*/
1409                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1410                         dev_err(&device->cdev->dev, "An error occurred in the "
1411                                 "DASD device driver, reason=%s\n", errorstring);
1412                         BUG();
1413                         break;
1414                 }
1415                 retries++;
1416         }
1417         dasd_schedule_device_bh(device);
1418         return rc;
1419 }
1420 EXPORT_SYMBOL(dasd_term_IO);
1421
1422 /*
1423  * Start the i/o. This start_IO can fail if the channel is really busy.
1424  * In that case set up a timer to start the request later.
1425  */
1426 int dasd_start_IO(struct dasd_ccw_req *cqr)
1427 {
1428         struct dasd_device *device;
1429         int rc;
1430         char errorstring[ERRORLENGTH];
1431
1432         /* Check the cqr */
1433         rc = dasd_check_cqr(cqr);
1434         if (rc) {
1435                 cqr->intrc = rc;
1436                 return rc;
1437         }
1438         device = (struct dasd_device *) cqr->startdev;
1439         if (((cqr->block &&
1440               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1441              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1442             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1443                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1444                               "because of stolen lock", cqr);
1445                 cqr->status = DASD_CQR_ERROR;
1446                 cqr->intrc = -EPERM;
1447                 return -EPERM;
1448         }
1449         if (cqr->retries < 0) {
1450                 /* internal error 14 - start_IO run out of retries */
1451                 sprintf(errorstring, "14 %p", cqr);
1452                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1453                         "device driver, reason=%s\n", errorstring);
1454                 cqr->status = DASD_CQR_ERROR;
1455                 return -EIO;
1456         }
1457         cqr->startclk = get_tod_clock();
1458         cqr->starttime = jiffies;
1459         cqr->retries--;
1460         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1461                 cqr->lpm &= dasd_path_get_opm(device);
1462                 if (!cqr->lpm)
1463                         cqr->lpm = dasd_path_get_opm(device);
1464         }
1465         if (cqr->cpmode == 1) {
1466                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1467                                          (long) cqr, cqr->lpm);
1468         } else {
1469                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1470                                       (long) cqr, cqr->lpm, 0);
1471         }
1472         switch (rc) {
1473         case 0:
1474                 cqr->status = DASD_CQR_IN_IO;
1475                 break;
1476         case -EBUSY:
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: device busy, retry later");
1479                 break;
1480         case -EACCES:
1481                 /* -EACCES indicates that the request used only a subset of the
1482                  * available paths and all these paths are gone. If the lpm of
1483                  * this request was only a subset of the opm (e.g. the ppm) then
1484                  * we just do a retry with all available paths.
1485                  * If we already use the full opm, something is amiss, and we
1486                  * need a full path verification.
1487                  */
1488                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1489                         DBF_DEV_EVENT(DBF_WARNING, device,
1490                                       "start_IO: selected paths gone (%x)",
1491                                       cqr->lpm);
1492                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1493                         cqr->lpm = dasd_path_get_opm(device);
1494                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1495                                       "start_IO: selected paths gone,"
1496                                       " retry on all paths");
1497                 } else {
1498                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1499                                       "start_IO: all paths in opm gone,"
1500                                       " do path verification");
1501                         dasd_generic_last_path_gone(device);
1502                         dasd_path_no_path(device);
1503                         dasd_path_set_tbvpm(device,
1504                                           ccw_device_get_path_mask(
1505                                                   device->cdev));
1506                 }
1507                 break;
1508         case -ENODEV:
1509                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1510                               "start_IO: -ENODEV device gone, retry");
1511                 break;
1512         case -EIO:
1513                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1514                               "start_IO: -EIO device gone, retry");
1515                 break;
1516         case -EINVAL:
1517                 /* most likely caused in power management context */
1518                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1519                               "start_IO: -EINVAL device currently "
1520                               "not accessible");
1521                 break;
1522         default:
1523                 /* internal error 11 - unknown rc */
1524                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1525                 dev_err(&device->cdev->dev,
1526                         "An error occurred in the DASD device driver, "
1527                         "reason=%s\n", errorstring);
1528                 BUG();
1529                 break;
1530         }
1531         cqr->intrc = rc;
1532         return rc;
1533 }
1534 EXPORT_SYMBOL(dasd_start_IO);
1535
1536 /*
1537  * Timeout function for dasd devices. This is used for different purposes
1538  *  1) missing interrupt handler for normal operation
1539  *  2) delayed start of request where start_IO failed with -EBUSY
1540  *  3) timeout for missing state change interrupts
1541  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1542  * DASD_CQR_QUEUED for 2) and 3).
1543  */
1544 static void dasd_device_timeout(struct timer_list *t)
1545 {
1546         unsigned long flags;
1547         struct dasd_device *device;
1548
1549         device = from_timer(device, t, timer);
1550         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1551         /* re-activate request queue */
1552         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1553         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1554         dasd_schedule_device_bh(device);
1555 }
1556
1557 /*
1558  * Setup timeout for a device in jiffies.
1559  */
1560 void dasd_device_set_timer(struct dasd_device *device, int expires)
1561 {
1562         if (expires == 0)
1563                 del_timer(&device->timer);
1564         else
1565                 mod_timer(&device->timer, jiffies + expires);
1566 }
1567 EXPORT_SYMBOL(dasd_device_set_timer);
1568
1569 /*
1570  * Clear timeout for a device.
1571  */
1572 void dasd_device_clear_timer(struct dasd_device *device)
1573 {
1574         del_timer(&device->timer);
1575 }
1576 EXPORT_SYMBOL(dasd_device_clear_timer);
1577
1578 static void dasd_handle_killed_request(struct ccw_device *cdev,
1579                                        unsigned long intparm)
1580 {
1581         struct dasd_ccw_req *cqr;
1582         struct dasd_device *device;
1583
1584         if (!intparm)
1585                 return;
1586         cqr = (struct dasd_ccw_req *) intparm;
1587         if (cqr->status != DASD_CQR_IN_IO) {
1588                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1589                                 "invalid status in handle_killed_request: "
1590                                 "%02x", cqr->status);
1591                 return;
1592         }
1593
1594         device = dasd_device_from_cdev_locked(cdev);
1595         if (IS_ERR(device)) {
1596                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1597                                 "unable to get device from cdev");
1598                 return;
1599         }
1600
1601         if (!cqr->startdev ||
1602             device != cqr->startdev ||
1603             strncmp(cqr->startdev->discipline->ebcname,
1604                     (char *) &cqr->magic, 4)) {
1605                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1606                                 "invalid device in request");
1607                 dasd_put_device(device);
1608                 return;
1609         }
1610
1611         /* Schedule request to be retried. */
1612         cqr->status = DASD_CQR_QUEUED;
1613
1614         dasd_device_clear_timer(device);
1615         dasd_schedule_device_bh(device);
1616         dasd_put_device(device);
1617 }
1618
1619 void dasd_generic_handle_state_change(struct dasd_device *device)
1620 {
1621         /* First of all start sense subsystem status request. */
1622         dasd_eer_snss(device);
1623
1624         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1625         dasd_schedule_device_bh(device);
1626         if (device->block) {
1627                 dasd_schedule_block_bh(device->block);
1628                 if (device->block->request_queue)
1629                         blk_mq_run_hw_queues(device->block->request_queue,
1630                                              true);
1631         }
1632 }
1633 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1634
1635 static int dasd_check_hpf_error(struct irb *irb)
1636 {
1637         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1638             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1639              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1640 }
1641
1642 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1643 {
1644         struct dasd_device *device = NULL;
1645         u8 *sense = NULL;
1646
1647         if (!block)
1648                 return 0;
1649         device = block->base;
1650         if (!device || !device->discipline->is_ese)
1651                 return 0;
1652         if (!device->discipline->is_ese(device))
1653                 return 0;
1654
1655         sense = dasd_get_sense(irb);
1656         if (!sense)
1657                 return 0;
1658
1659         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1660                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1661                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1662 }
1663
1664 static int dasd_ese_oos_cond(u8 *sense)
1665 {
1666         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1667                 sense[1] & SNS1_PERM_ERR &&
1668                 sense[1] & SNS1_WRITE_INHIBITED &&
1669                 sense[25] == 0x01;
1670 }
1671
1672 /*
1673  * Interrupt handler for "normal" ssch-io based dasd devices.
1674  */
1675 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1676                       struct irb *irb)
1677 {
1678         struct dasd_ccw_req *cqr, *next, *fcqr;
1679         struct dasd_device *device;
1680         unsigned long now;
1681         int nrf_suppressed = 0;
1682         int fp_suppressed = 0;
1683         u8 *sense = NULL;
1684         int expires;
1685
1686         cqr = (struct dasd_ccw_req *) intparm;
1687         if (IS_ERR(irb)) {
1688                 switch (PTR_ERR(irb)) {
1689                 case -EIO:
1690                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1691                                 device = cqr->startdev;
1692                                 cqr->status = DASD_CQR_CLEARED;
1693                                 dasd_device_clear_timer(device);
1694                                 wake_up(&dasd_flush_wq);
1695                                 dasd_schedule_device_bh(device);
1696                                 return;
1697                         }
1698                         break;
1699                 case -ETIMEDOUT:
1700                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1701                                         "request timed out\n", __func__);
1702                         break;
1703                 default:
1704                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1705                                         "unknown error %ld\n", __func__,
1706                                         PTR_ERR(irb));
1707                 }
1708                 dasd_handle_killed_request(cdev, intparm);
1709                 return;
1710         }
1711
1712         now = get_tod_clock();
1713         /* check for conditions that should be handled immediately */
1714         if (!cqr ||
1715             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1716               scsw_cstat(&irb->scsw) == 0)) {
1717                 if (cqr)
1718                         memcpy(&cqr->irb, irb, sizeof(*irb));
1719                 device = dasd_device_from_cdev_locked(cdev);
1720                 if (IS_ERR(device))
1721                         return;
1722                 /* ignore unsolicited interrupts for DIAG discipline */
1723                 if (device->discipline == dasd_diag_discipline_pointer) {
1724                         dasd_put_device(device);
1725                         return;
1726                 }
1727
1728                 /*
1729                  * In some cases 'File Protected' or 'No Record Found' errors
1730                  * might be expected and debug log messages for the
1731                  * corresponding interrupts shouldn't be written then.
1732                  * Check if either of the according suppress bits is set.
1733                  */
1734                 sense = dasd_get_sense(irb);
1735                 if (sense) {
1736                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1737                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1738                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1739                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1740
1741                         /*
1742                          * Extent pool probably out-of-space.
1743                          * Stop device and check exhaust level.
1744                          */
1745                         if (dasd_ese_oos_cond(sense)) {
1746                                 dasd_generic_space_exhaust(device, cqr);
1747                                 device->discipline->ext_pool_exhaust(device, cqr);
1748                                 dasd_put_device(device);
1749                                 return;
1750                         }
1751                 }
1752                 if (!(fp_suppressed || nrf_suppressed))
1753                         device->discipline->dump_sense_dbf(device, irb, "int");
1754
1755                 if (device->features & DASD_FEATURE_ERPLOG)
1756                         device->discipline->dump_sense(device, cqr, irb);
1757                 device->discipline->check_for_device_change(device, cqr, irb);
1758                 dasd_put_device(device);
1759         }
1760
1761         /* check for for attention message */
1762         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1763                 device = dasd_device_from_cdev_locked(cdev);
1764                 if (!IS_ERR(device)) {
1765                         device->discipline->check_attention(device,
1766                                                             irb->esw.esw1.lpum);
1767                         dasd_put_device(device);
1768                 }
1769         }
1770
1771         if (!cqr)
1772                 return;
1773
1774         device = (struct dasd_device *) cqr->startdev;
1775         if (!device ||
1776             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1777                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1778                                 "invalid device in request");
1779                 return;
1780         }
1781
1782         if (dasd_ese_needs_format(cqr->block, irb)) {
1783                 if (rq_data_dir((struct request *)cqr->callback_data) == READ) {
1784                         device->discipline->ese_read(cqr, irb);
1785                         cqr->status = DASD_CQR_SUCCESS;
1786                         cqr->stopclk = now;
1787                         dasd_device_clear_timer(device);
1788                         dasd_schedule_device_bh(device);
1789                         return;
1790                 }
1791                 fcqr = device->discipline->ese_format(device, cqr, irb);
1792                 if (IS_ERR(fcqr)) {
1793                         if (PTR_ERR(fcqr) == -EINVAL) {
1794                                 cqr->status = DASD_CQR_ERROR;
1795                                 return;
1796                         }
1797                         /*
1798                          * If we can't format now, let the request go
1799                          * one extra round. Maybe we can format later.
1800                          */
1801                         cqr->status = DASD_CQR_QUEUED;
1802                         dasd_schedule_device_bh(device);
1803                         return;
1804                 } else {
1805                         fcqr->status = DASD_CQR_QUEUED;
1806                         cqr->status = DASD_CQR_QUEUED;
1807                         list_add(&fcqr->devlist, &device->ccw_queue);
1808                         dasd_schedule_device_bh(device);
1809                         return;
1810                 }
1811         }
1812
1813         /* Check for clear pending */
1814         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1815             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1816                 cqr->status = DASD_CQR_CLEARED;
1817                 dasd_device_clear_timer(device);
1818                 wake_up(&dasd_flush_wq);
1819                 dasd_schedule_device_bh(device);
1820                 return;
1821         }
1822
1823         /* check status - the request might have been killed by dyn detach */
1824         if (cqr->status != DASD_CQR_IN_IO) {
1825                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1826                               "status %02x", dev_name(&cdev->dev), cqr->status);
1827                 return;
1828         }
1829
1830         next = NULL;
1831         expires = 0;
1832         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1833             scsw_cstat(&irb->scsw) == 0) {
1834                 /* request was completed successfully */
1835                 cqr->status = DASD_CQR_SUCCESS;
1836                 cqr->stopclk = now;
1837                 /* Start first request on queue if possible -> fast_io. */
1838                 if (cqr->devlist.next != &device->ccw_queue) {
1839                         next = list_entry(cqr->devlist.next,
1840                                           struct dasd_ccw_req, devlist);
1841                 }
1842         } else {  /* error */
1843                 /* check for HPF error
1844                  * call discipline function to requeue all requests
1845                  * and disable HPF accordingly
1846                  */
1847                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1848                     device->discipline->handle_hpf_error)
1849                         device->discipline->handle_hpf_error(device, irb);
1850                 /*
1851                  * If we don't want complex ERP for this request, then just
1852                  * reset this and retry it in the fastpath
1853                  */
1854                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1855                     cqr->retries > 0) {
1856                         if (cqr->lpm == dasd_path_get_opm(device))
1857                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1858                                               "default ERP in fastpath "
1859                                               "(%i retries left)",
1860                                               cqr->retries);
1861                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1862                                 cqr->lpm = dasd_path_get_opm(device);
1863                         cqr->status = DASD_CQR_QUEUED;
1864                         next = cqr;
1865                 } else
1866                         cqr->status = DASD_CQR_ERROR;
1867         }
1868         if (next && (next->status == DASD_CQR_QUEUED) &&
1869             (!device->stopped)) {
1870                 if (device->discipline->start_IO(next) == 0)
1871                         expires = next->expires;
1872         }
1873         if (expires != 0)
1874                 dasd_device_set_timer(device, expires);
1875         else
1876                 dasd_device_clear_timer(device);
1877         dasd_schedule_device_bh(device);
1878 }
1879 EXPORT_SYMBOL(dasd_int_handler);
1880
1881 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1882 {
1883         struct dasd_device *device;
1884
1885         device = dasd_device_from_cdev_locked(cdev);
1886
1887         if (IS_ERR(device))
1888                 goto out;
1889         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1890            device->state != device->target ||
1891            !device->discipline->check_for_device_change){
1892                 dasd_put_device(device);
1893                 goto out;
1894         }
1895         if (device->discipline->dump_sense_dbf)
1896                 device->discipline->dump_sense_dbf(device, irb, "uc");
1897         device->discipline->check_for_device_change(device, NULL, irb);
1898         dasd_put_device(device);
1899 out:
1900         return UC_TODO_RETRY;
1901 }
1902 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1903
1904 /*
1905  * If we have an error on a dasd_block layer request then we cancel
1906  * and return all further requests from the same dasd_block as well.
1907  */
1908 static void __dasd_device_recovery(struct dasd_device *device,
1909                                    struct dasd_ccw_req *ref_cqr)
1910 {
1911         struct list_head *l, *n;
1912         struct dasd_ccw_req *cqr;
1913
1914         /*
1915          * only requeue request that came from the dasd_block layer
1916          */
1917         if (!ref_cqr->block)
1918                 return;
1919
1920         list_for_each_safe(l, n, &device->ccw_queue) {
1921                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1922                 if (cqr->status == DASD_CQR_QUEUED &&
1923                     ref_cqr->block == cqr->block) {
1924                         cqr->status = DASD_CQR_CLEARED;
1925                 }
1926         }
1927 };
1928
1929 /*
1930  * Remove those ccw requests from the queue that need to be returned
1931  * to the upper layer.
1932  */
1933 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1934                                             struct list_head *final_queue)
1935 {
1936         struct list_head *l, *n;
1937         struct dasd_ccw_req *cqr;
1938
1939         /* Process request with final status. */
1940         list_for_each_safe(l, n, &device->ccw_queue) {
1941                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1942
1943                 /* Skip any non-final request. */
1944                 if (cqr->status == DASD_CQR_QUEUED ||
1945                     cqr->status == DASD_CQR_IN_IO ||
1946                     cqr->status == DASD_CQR_CLEAR_PENDING)
1947                         continue;
1948                 if (cqr->status == DASD_CQR_ERROR) {
1949                         __dasd_device_recovery(device, cqr);
1950                 }
1951                 /* Rechain finished requests to final queue */
1952                 list_move_tail(&cqr->devlist, final_queue);
1953         }
1954 }
1955
1956 static void __dasd_process_cqr(struct dasd_device *device,
1957                                struct dasd_ccw_req *cqr)
1958 {
1959         char errorstring[ERRORLENGTH];
1960
1961         switch (cqr->status) {
1962         case DASD_CQR_SUCCESS:
1963                 cqr->status = DASD_CQR_DONE;
1964                 break;
1965         case DASD_CQR_ERROR:
1966                 cqr->status = DASD_CQR_NEED_ERP;
1967                 break;
1968         case DASD_CQR_CLEARED:
1969                 cqr->status = DASD_CQR_TERMINATED;
1970                 break;
1971         default:
1972                 /* internal error 12 - wrong cqr status*/
1973                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1974                 dev_err(&device->cdev->dev,
1975                         "An error occurred in the DASD device driver, "
1976                         "reason=%s\n", errorstring);
1977                 BUG();
1978         }
1979         if (cqr->callback)
1980                 cqr->callback(cqr, cqr->callback_data);
1981 }
1982
1983 /*
1984  * the cqrs from the final queue are returned to the upper layer
1985  * by setting a dasd_block state and calling the callback function
1986  */
1987 static void __dasd_device_process_final_queue(struct dasd_device *device,
1988                                               struct list_head *final_queue)
1989 {
1990         struct list_head *l, *n;
1991         struct dasd_ccw_req *cqr;
1992         struct dasd_block *block;
1993
1994         list_for_each_safe(l, n, final_queue) {
1995                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1996                 list_del_init(&cqr->devlist);
1997                 block = cqr->block;
1998                 if (!block) {
1999                         __dasd_process_cqr(device, cqr);
2000                 } else {
2001                         spin_lock_bh(&block->queue_lock);
2002                         __dasd_process_cqr(device, cqr);
2003                         spin_unlock_bh(&block->queue_lock);
2004                 }
2005         }
2006 }
2007
2008 /*
2009  * Take a look at the first request on the ccw queue and check
2010  * if it reached its expire time. If so, terminate the IO.
2011  */
2012 static void __dasd_device_check_expire(struct dasd_device *device)
2013 {
2014         struct dasd_ccw_req *cqr;
2015
2016         if (list_empty(&device->ccw_queue))
2017                 return;
2018         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2019         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
2020             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
2021                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2022                         /*
2023                          * IO in safe offline processing should not
2024                          * run out of retries
2025                          */
2026                         cqr->retries++;
2027                 }
2028                 if (device->discipline->term_IO(cqr) != 0) {
2029                         /* Hmpf, try again in 5 sec */
2030                         dev_err(&device->cdev->dev,
2031                                 "cqr %p timed out (%lus) but cannot be "
2032                                 "ended, retrying in 5 s\n",
2033                                 cqr, (cqr->expires/HZ));
2034                         cqr->expires += 5*HZ;
2035                         dasd_device_set_timer(device, 5*HZ);
2036                 } else {
2037                         dev_err(&device->cdev->dev,
2038                                 "cqr %p timed out (%lus), %i retries "
2039                                 "remaining\n", cqr, (cqr->expires/HZ),
2040                                 cqr->retries);
2041                 }
2042         }
2043 }
2044
2045 /*
2046  * return 1 when device is not eligible for IO
2047  */
2048 static int __dasd_device_is_unusable(struct dasd_device *device,
2049                                      struct dasd_ccw_req *cqr)
2050 {
2051         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM | DASD_STOPPED_NOSPC);
2052
2053         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2054             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2055                 /*
2056                  * dasd is being set offline
2057                  * but it is no safe offline where we have to allow I/O
2058                  */
2059                 return 1;
2060         }
2061         if (device->stopped) {
2062                 if (device->stopped & mask) {
2063                         /* stopped and CQR will not change that. */
2064                         return 1;
2065                 }
2066                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2067                         /* CQR is not able to change device to
2068                          * operational. */
2069                         return 1;
2070                 }
2071                 /* CQR required to get device operational. */
2072         }
2073         return 0;
2074 }
2075
2076 /*
2077  * Take a look at the first request on the ccw queue and check
2078  * if it needs to be started.
2079  */
2080 static void __dasd_device_start_head(struct dasd_device *device)
2081 {
2082         struct dasd_ccw_req *cqr;
2083         int rc;
2084
2085         if (list_empty(&device->ccw_queue))
2086                 return;
2087         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2088         if (cqr->status != DASD_CQR_QUEUED)
2089                 return;
2090         /* if device is not usable return request to upper layer */
2091         if (__dasd_device_is_unusable(device, cqr)) {
2092                 cqr->intrc = -EAGAIN;
2093                 cqr->status = DASD_CQR_CLEARED;
2094                 dasd_schedule_device_bh(device);
2095                 return;
2096         }
2097
2098         rc = device->discipline->start_IO(cqr);
2099         if (rc == 0)
2100                 dasd_device_set_timer(device, cqr->expires);
2101         else if (rc == -EACCES) {
2102                 dasd_schedule_device_bh(device);
2103         } else
2104                 /* Hmpf, try again in 1/2 sec */
2105                 dasd_device_set_timer(device, 50);
2106 }
2107
2108 static void __dasd_device_check_path_events(struct dasd_device *device)
2109 {
2110         int rc;
2111
2112         if (!dasd_path_get_tbvpm(device))
2113                 return;
2114
2115         if (device->stopped &
2116             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2117                 return;
2118         rc = device->discipline->verify_path(device,
2119                                              dasd_path_get_tbvpm(device));
2120         if (rc)
2121                 dasd_device_set_timer(device, 50);
2122         else
2123                 dasd_path_clear_all_verify(device);
2124 };
2125
2126 /*
2127  * Go through all request on the dasd_device request queue,
2128  * terminate them on the cdev if necessary, and return them to the
2129  * submitting layer via callback.
2130  * Note:
2131  * Make sure that all 'submitting layers' still exist when
2132  * this function is called!. In other words, when 'device' is a base
2133  * device then all block layer requests must have been removed before
2134  * via dasd_flush_block_queue.
2135  */
2136 int dasd_flush_device_queue(struct dasd_device *device)
2137 {
2138         struct dasd_ccw_req *cqr, *n;
2139         int rc;
2140         struct list_head flush_queue;
2141
2142         INIT_LIST_HEAD(&flush_queue);
2143         spin_lock_irq(get_ccwdev_lock(device->cdev));
2144         rc = 0;
2145         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2146                 /* Check status and move request to flush_queue */
2147                 switch (cqr->status) {
2148                 case DASD_CQR_IN_IO:
2149                         rc = device->discipline->term_IO(cqr);
2150                         if (rc) {
2151                                 /* unable to terminate requeust */
2152                                 dev_err(&device->cdev->dev,
2153                                         "Flushing the DASD request queue "
2154                                         "failed for request %p\n", cqr);
2155                                 /* stop flush processing */
2156                                 goto finished;
2157                         }
2158                         break;
2159                 case DASD_CQR_QUEUED:
2160                         cqr->stopclk = get_tod_clock();
2161                         cqr->status = DASD_CQR_CLEARED;
2162                         break;
2163                 default: /* no need to modify the others */
2164                         break;
2165                 }
2166                 list_move_tail(&cqr->devlist, &flush_queue);
2167         }
2168 finished:
2169         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2170         /*
2171          * After this point all requests must be in state CLEAR_PENDING,
2172          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2173          * one of the others.
2174          */
2175         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2176                 wait_event(dasd_flush_wq,
2177                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2178         /*
2179          * Now set each request back to TERMINATED, DONE or NEED_ERP
2180          * and call the callback function of flushed requests
2181          */
2182         __dasd_device_process_final_queue(device, &flush_queue);
2183         return rc;
2184 }
2185 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2186
2187 /*
2188  * Acquire the device lock and process queues for the device.
2189  */
2190 static void dasd_device_tasklet(unsigned long data)
2191 {
2192         struct dasd_device *device = (struct dasd_device *) data;
2193         struct list_head final_queue;
2194
2195         atomic_set (&device->tasklet_scheduled, 0);
2196         INIT_LIST_HEAD(&final_queue);
2197         spin_lock_irq(get_ccwdev_lock(device->cdev));
2198         /* Check expire time of first request on the ccw queue. */
2199         __dasd_device_check_expire(device);
2200         /* find final requests on ccw queue */
2201         __dasd_device_process_ccw_queue(device, &final_queue);
2202         __dasd_device_check_path_events(device);
2203         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2204         /* Now call the callback function of requests with final status */
2205         __dasd_device_process_final_queue(device, &final_queue);
2206         spin_lock_irq(get_ccwdev_lock(device->cdev));
2207         /* Now check if the head of the ccw queue needs to be started. */
2208         __dasd_device_start_head(device);
2209         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2210         if (waitqueue_active(&shutdown_waitq))
2211                 wake_up(&shutdown_waitq);
2212         dasd_put_device(device);
2213 }
2214
2215 /*
2216  * Schedules a call to dasd_tasklet over the device tasklet.
2217  */
2218 void dasd_schedule_device_bh(struct dasd_device *device)
2219 {
2220         /* Protect against rescheduling. */
2221         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2222                 return;
2223         dasd_get_device(device);
2224         tasklet_hi_schedule(&device->tasklet);
2225 }
2226 EXPORT_SYMBOL(dasd_schedule_device_bh);
2227
2228 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2229 {
2230         device->stopped |= bits;
2231 }
2232 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2233
2234 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2235 {
2236         device->stopped &= ~bits;
2237         if (!device->stopped)
2238                 wake_up(&generic_waitq);
2239 }
2240 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2241
2242 /*
2243  * Queue a request to the head of the device ccw_queue.
2244  * Start the I/O if possible.
2245  */
2246 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2247 {
2248         struct dasd_device *device;
2249         unsigned long flags;
2250
2251         device = cqr->startdev;
2252         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2253         cqr->status = DASD_CQR_QUEUED;
2254         list_add(&cqr->devlist, &device->ccw_queue);
2255         /* let the bh start the request to keep them in order */
2256         dasd_schedule_device_bh(device);
2257         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2258 }
2259 EXPORT_SYMBOL(dasd_add_request_head);
2260
2261 /*
2262  * Queue a request to the tail of the device ccw_queue.
2263  * Start the I/O if possible.
2264  */
2265 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2266 {
2267         struct dasd_device *device;
2268         unsigned long flags;
2269
2270         device = cqr->startdev;
2271         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2272         cqr->status = DASD_CQR_QUEUED;
2273         list_add_tail(&cqr->devlist, &device->ccw_queue);
2274         /* let the bh start the request to keep them in order */
2275         dasd_schedule_device_bh(device);
2276         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2277 }
2278 EXPORT_SYMBOL(dasd_add_request_tail);
2279
2280 /*
2281  * Wakeup helper for the 'sleep_on' functions.
2282  */
2283 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2284 {
2285         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2286         cqr->callback_data = DASD_SLEEPON_END_TAG;
2287         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2288         wake_up(&generic_waitq);
2289 }
2290 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2291
2292 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2293 {
2294         struct dasd_device *device;
2295         int rc;
2296
2297         device = cqr->startdev;
2298         spin_lock_irq(get_ccwdev_lock(device->cdev));
2299         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2300         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2301         return rc;
2302 }
2303
2304 /*
2305  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2306  */
2307 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2308 {
2309         struct dasd_device *device;
2310         dasd_erp_fn_t erp_fn;
2311
2312         if (cqr->status == DASD_CQR_FILLED)
2313                 return 0;
2314         device = cqr->startdev;
2315         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2316                 if (cqr->status == DASD_CQR_TERMINATED) {
2317                         device->discipline->handle_terminated_request(cqr);
2318                         return 1;
2319                 }
2320                 if (cqr->status == DASD_CQR_NEED_ERP) {
2321                         erp_fn = device->discipline->erp_action(cqr);
2322                         erp_fn(cqr);
2323                         return 1;
2324                 }
2325                 if (cqr->status == DASD_CQR_FAILED)
2326                         dasd_log_sense(cqr, &cqr->irb);
2327                 if (cqr->refers) {
2328                         __dasd_process_erp(device, cqr);
2329                         return 1;
2330                 }
2331         }
2332         return 0;
2333 }
2334
2335 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2336 {
2337         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2338                 if (cqr->refers) /* erp is not done yet */
2339                         return 1;
2340                 return ((cqr->status != DASD_CQR_DONE) &&
2341                         (cqr->status != DASD_CQR_FAILED));
2342         } else
2343                 return (cqr->status == DASD_CQR_FILLED);
2344 }
2345
2346 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2347 {
2348         struct dasd_device *device;
2349         int rc;
2350         struct list_head ccw_queue;
2351         struct dasd_ccw_req *cqr;
2352
2353         INIT_LIST_HEAD(&ccw_queue);
2354         maincqr->status = DASD_CQR_FILLED;
2355         device = maincqr->startdev;
2356         list_add(&maincqr->blocklist, &ccw_queue);
2357         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2358              cqr = list_first_entry(&ccw_queue,
2359                                     struct dasd_ccw_req, blocklist)) {
2360
2361                 if (__dasd_sleep_on_erp(cqr))
2362                         continue;
2363                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2364                         continue;
2365                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2366                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2367                         cqr->status = DASD_CQR_FAILED;
2368                         cqr->intrc = -EPERM;
2369                         continue;
2370                 }
2371                 /* Non-temporary stop condition will trigger fail fast */
2372                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2373                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2374                     (!dasd_eer_enabled(device))) {
2375                         cqr->status = DASD_CQR_FAILED;
2376                         cqr->intrc = -ENOLINK;
2377                         continue;
2378                 }
2379                 /*
2380                  * Don't try to start requests if device is in
2381                  * offline processing, it might wait forever
2382                  */
2383                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2384                         cqr->status = DASD_CQR_FAILED;
2385                         cqr->intrc = -ENODEV;
2386                         continue;
2387                 }
2388                 /*
2389                  * Don't try to start requests if device is stopped
2390                  * except path verification requests
2391                  */
2392                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2393                         if (interruptible) {
2394                                 rc = wait_event_interruptible(
2395                                         generic_waitq, !(device->stopped));
2396                                 if (rc == -ERESTARTSYS) {
2397                                         cqr->status = DASD_CQR_FAILED;
2398                                         maincqr->intrc = rc;
2399                                         continue;
2400                                 }
2401                         } else
2402                                 wait_event(generic_waitq, !(device->stopped));
2403                 }
2404                 if (!cqr->callback)
2405                         cqr->callback = dasd_wakeup_cb;
2406
2407                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2408                 dasd_add_request_tail(cqr);
2409                 if (interruptible) {
2410                         rc = wait_event_interruptible(
2411                                 generic_waitq, _wait_for_wakeup(cqr));
2412                         if (rc == -ERESTARTSYS) {
2413                                 dasd_cancel_req(cqr);
2414                                 /* wait (non-interruptible) for final status */
2415                                 wait_event(generic_waitq,
2416                                            _wait_for_wakeup(cqr));
2417                                 cqr->status = DASD_CQR_FAILED;
2418                                 maincqr->intrc = rc;
2419                                 continue;
2420                         }
2421                 } else
2422                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2423         }
2424
2425         maincqr->endclk = get_tod_clock();
2426         if ((maincqr->status != DASD_CQR_DONE) &&
2427             (maincqr->intrc != -ERESTARTSYS))
2428                 dasd_log_sense(maincqr, &maincqr->irb);
2429         if (maincqr->status == DASD_CQR_DONE)
2430                 rc = 0;
2431         else if (maincqr->intrc)
2432                 rc = maincqr->intrc;
2433         else
2434                 rc = -EIO;
2435         return rc;
2436 }
2437
2438 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2439 {
2440         struct dasd_ccw_req *cqr;
2441
2442         list_for_each_entry(cqr, ccw_queue, blocklist) {
2443                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2444                         return 0;
2445         }
2446
2447         return 1;
2448 }
2449
2450 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2451 {
2452         struct dasd_device *device;
2453         struct dasd_ccw_req *cqr, *n;
2454         u8 *sense = NULL;
2455         int rc;
2456
2457 retry:
2458         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2459                 device = cqr->startdev;
2460                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2461                         continue;
2462
2463                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2464                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2465                         cqr->status = DASD_CQR_FAILED;
2466                         cqr->intrc = -EPERM;
2467                         continue;
2468                 }
2469                 /*Non-temporary stop condition will trigger fail fast*/
2470                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2471                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2472                     !dasd_eer_enabled(device)) {
2473                         cqr->status = DASD_CQR_FAILED;
2474                         cqr->intrc = -EAGAIN;
2475                         continue;
2476                 }
2477
2478                 /*Don't try to start requests if device is stopped*/
2479                 if (interruptible) {
2480                         rc = wait_event_interruptible(
2481                                 generic_waitq, !device->stopped);
2482                         if (rc == -ERESTARTSYS) {
2483                                 cqr->status = DASD_CQR_FAILED;
2484                                 cqr->intrc = rc;
2485                                 continue;
2486                         }
2487                 } else
2488                         wait_event(generic_waitq, !(device->stopped));
2489
2490                 if (!cqr->callback)
2491                         cqr->callback = dasd_wakeup_cb;
2492                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2493                 dasd_add_request_tail(cqr);
2494         }
2495
2496         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2497
2498         rc = 0;
2499         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2500                 /*
2501                  * In some cases the 'File Protected' or 'Incorrect Length'
2502                  * error might be expected and error recovery would be
2503                  * unnecessary in these cases.  Check if the according suppress
2504                  * bit is set.
2505                  */
2506                 sense = dasd_get_sense(&cqr->irb);
2507                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2508                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2509                         continue;
2510                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2511                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2512                         continue;
2513
2514                 /*
2515                  * for alias devices simplify error recovery and
2516                  * return to upper layer
2517                  * do not skip ERP requests
2518                  */
2519                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2520                     (cqr->status == DASD_CQR_TERMINATED ||
2521                      cqr->status == DASD_CQR_NEED_ERP))
2522                         return -EAGAIN;
2523
2524                 /* normal recovery for basedev IO */
2525                 if (__dasd_sleep_on_erp(cqr))
2526                         /* handle erp first */
2527                         goto retry;
2528         }
2529
2530         return 0;
2531 }
2532
2533 /*
2534  * Queue a request to the tail of the device ccw_queue and wait for
2535  * it's completion.
2536  */
2537 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2538 {
2539         return _dasd_sleep_on(cqr, 0);
2540 }
2541 EXPORT_SYMBOL(dasd_sleep_on);
2542
2543 /*
2544  * Start requests from a ccw_queue and wait for their completion.
2545  */
2546 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2547 {
2548         return _dasd_sleep_on_queue(ccw_queue, 0);
2549 }
2550 EXPORT_SYMBOL(dasd_sleep_on_queue);
2551
2552 /*
2553  * Start requests from a ccw_queue and wait interruptible for their completion.
2554  */
2555 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2556 {
2557         return _dasd_sleep_on_queue(ccw_queue, 1);
2558 }
2559 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2560
2561 /*
2562  * Queue a request to the tail of the device ccw_queue and wait
2563  * interruptible for it's completion.
2564  */
2565 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2566 {
2567         return _dasd_sleep_on(cqr, 1);
2568 }
2569 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2570
2571 /*
2572  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2573  * for eckd devices) the currently running request has to be terminated
2574  * and be put back to status queued, before the special request is added
2575  * to the head of the queue. Then the special request is waited on normally.
2576  */
2577 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2578 {
2579         struct dasd_ccw_req *cqr;
2580         int rc;
2581
2582         if (list_empty(&device->ccw_queue))
2583                 return 0;
2584         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2585         rc = device->discipline->term_IO(cqr);
2586         if (!rc)
2587                 /*
2588                  * CQR terminated because a more important request is pending.
2589                  * Undo decreasing of retry counter because this is
2590                  * not an error case.
2591                  */
2592                 cqr->retries++;
2593         return rc;
2594 }
2595
2596 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2597 {
2598         struct dasd_device *device;
2599         int rc;
2600
2601         device = cqr->startdev;
2602         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2603             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2604                 cqr->status = DASD_CQR_FAILED;
2605                 cqr->intrc = -EPERM;
2606                 return -EIO;
2607         }
2608         spin_lock_irq(get_ccwdev_lock(device->cdev));
2609         rc = _dasd_term_running_cqr(device);
2610         if (rc) {
2611                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2612                 return rc;
2613         }
2614         cqr->callback = dasd_wakeup_cb;
2615         cqr->callback_data = DASD_SLEEPON_START_TAG;
2616         cqr->status = DASD_CQR_QUEUED;
2617         /*
2618          * add new request as second
2619          * first the terminated cqr needs to be finished
2620          */
2621         list_add(&cqr->devlist, device->ccw_queue.next);
2622
2623         /* let the bh start the request to keep them in order */
2624         dasd_schedule_device_bh(device);
2625
2626         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2627
2628         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2629
2630         if (cqr->status == DASD_CQR_DONE)
2631                 rc = 0;
2632         else if (cqr->intrc)
2633                 rc = cqr->intrc;
2634         else
2635                 rc = -EIO;
2636
2637         /* kick tasklets */
2638         dasd_schedule_device_bh(device);
2639         if (device->block)
2640                 dasd_schedule_block_bh(device->block);
2641
2642         return rc;
2643 }
2644 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2645
2646 /*
2647  * Cancels a request that was started with dasd_sleep_on_req.
2648  * This is useful to timeout requests. The request will be
2649  * terminated if it is currently in i/o.
2650  * Returns 0 if request termination was successful
2651  *         negative error code if termination failed
2652  * Cancellation of a request is an asynchronous operation! The calling
2653  * function has to wait until the request is properly returned via callback.
2654  */
2655 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2656 {
2657         struct dasd_device *device = cqr->startdev;
2658         int rc = 0;
2659
2660         switch (cqr->status) {
2661         case DASD_CQR_QUEUED:
2662                 /* request was not started - just set to cleared */
2663                 cqr->status = DASD_CQR_CLEARED;
2664                 break;
2665         case DASD_CQR_IN_IO:
2666                 /* request in IO - terminate IO and release again */
2667                 rc = device->discipline->term_IO(cqr);
2668                 if (rc) {
2669                         dev_err(&device->cdev->dev,
2670                                 "Cancelling request %p failed with rc=%d\n",
2671                                 cqr, rc);
2672                 } else {
2673                         cqr->stopclk = get_tod_clock();
2674                 }
2675                 break;
2676         default: /* already finished or clear pending - do nothing */
2677                 break;
2678         }
2679         dasd_schedule_device_bh(device);
2680         return rc;
2681 }
2682
2683 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2684 {
2685         struct dasd_device *device = cqr->startdev;
2686         unsigned long flags;
2687         int rc;
2688
2689         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2690         rc = __dasd_cancel_req(cqr);
2691         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2692         return rc;
2693 }
2694
2695 /*
2696  * SECTION: Operations of the dasd_block layer.
2697  */
2698
2699 /*
2700  * Timeout function for dasd_block. This is used when the block layer
2701  * is waiting for something that may not come reliably, (e.g. a state
2702  * change interrupt)
2703  */
2704 static void dasd_block_timeout(struct timer_list *t)
2705 {
2706         unsigned long flags;
2707         struct dasd_block *block;
2708
2709         block = from_timer(block, t, timer);
2710         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2711         /* re-activate request queue */
2712         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2713         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2714         dasd_schedule_block_bh(block);
2715         blk_mq_run_hw_queues(block->request_queue, true);
2716 }
2717
2718 /*
2719  * Setup timeout for a dasd_block in jiffies.
2720  */
2721 void dasd_block_set_timer(struct dasd_block *block, int expires)
2722 {
2723         if (expires == 0)
2724                 del_timer(&block->timer);
2725         else
2726                 mod_timer(&block->timer, jiffies + expires);
2727 }
2728 EXPORT_SYMBOL(dasd_block_set_timer);
2729
2730 /*
2731  * Clear timeout for a dasd_block.
2732  */
2733 void dasd_block_clear_timer(struct dasd_block *block)
2734 {
2735         del_timer(&block->timer);
2736 }
2737 EXPORT_SYMBOL(dasd_block_clear_timer);
2738
2739 /*
2740  * Process finished error recovery ccw.
2741  */
2742 static void __dasd_process_erp(struct dasd_device *device,
2743                                struct dasd_ccw_req *cqr)
2744 {
2745         dasd_erp_fn_t erp_fn;
2746
2747         if (cqr->status == DASD_CQR_DONE)
2748                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2749         else
2750                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2751         erp_fn = device->discipline->erp_postaction(cqr);
2752         erp_fn(cqr);
2753 }
2754
2755 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2756 {
2757         struct request *req;
2758         blk_status_t error = BLK_STS_OK;
2759         unsigned int proc_bytes;
2760         int status;
2761
2762         req = (struct request *) cqr->callback_data;
2763         dasd_profile_end(cqr->block, cqr, req);
2764
2765         proc_bytes = cqr->proc_bytes;
2766         status = cqr->block->base->discipline->free_cp(cqr, req);
2767         if (status < 0)
2768                 error = errno_to_blk_status(status);
2769         else if (status == 0) {
2770                 switch (cqr->intrc) {
2771                 case -EPERM:
2772                         error = BLK_STS_NEXUS;
2773                         break;
2774                 case -ENOLINK:
2775                         error = BLK_STS_TRANSPORT;
2776                         break;
2777                 case -ETIMEDOUT:
2778                         error = BLK_STS_TIMEOUT;
2779                         break;
2780                 default:
2781                         error = BLK_STS_IOERR;
2782                         break;
2783                 }
2784         }
2785
2786         /*
2787          * We need to take care for ETIMEDOUT errors here since the
2788          * complete callback does not get called in this case.
2789          * Take care of all errors here and avoid additional code to
2790          * transfer the error value to the complete callback.
2791          */
2792         if (error) {
2793                 blk_mq_end_request(req, error);
2794                 blk_mq_run_hw_queues(req->q, true);
2795         } else {
2796                 /*
2797                  * Partial completed requests can happen with ESE devices.
2798                  * During read we might have gotten a NRF error and have to
2799                  * complete a request partially.
2800                  */
2801                 if (proc_bytes) {
2802                         blk_update_request(req, BLK_STS_OK,
2803                                            blk_rq_bytes(req) - proc_bytes);
2804                         blk_mq_requeue_request(req, true);
2805                 } else if (likely(!blk_should_fake_timeout(req->q))) {
2806                         blk_mq_complete_request(req);
2807                 }
2808         }
2809 }
2810
2811 /*
2812  * Process ccw request queue.
2813  */
2814 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2815                                            struct list_head *final_queue)
2816 {
2817         struct list_head *l, *n;
2818         struct dasd_ccw_req *cqr;
2819         dasd_erp_fn_t erp_fn;
2820         unsigned long flags;
2821         struct dasd_device *base = block->base;
2822
2823 restart:
2824         /* Process request with final status. */
2825         list_for_each_safe(l, n, &block->ccw_queue) {
2826                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2827                 if (cqr->status != DASD_CQR_DONE &&
2828                     cqr->status != DASD_CQR_FAILED &&
2829                     cqr->status != DASD_CQR_NEED_ERP &&
2830                     cqr->status != DASD_CQR_TERMINATED)
2831                         continue;
2832
2833                 if (cqr->status == DASD_CQR_TERMINATED) {
2834                         base->discipline->handle_terminated_request(cqr);
2835                         goto restart;
2836                 }
2837
2838                 /*  Process requests that may be recovered */
2839                 if (cqr->status == DASD_CQR_NEED_ERP) {
2840                         erp_fn = base->discipline->erp_action(cqr);
2841                         if (IS_ERR(erp_fn(cqr)))
2842                                 continue;
2843                         goto restart;
2844                 }
2845
2846                 /* log sense for fatal error */
2847                 if (cqr->status == DASD_CQR_FAILED) {
2848                         dasd_log_sense(cqr, &cqr->irb);
2849                 }
2850
2851                 /* First of all call extended error reporting. */
2852                 if (dasd_eer_enabled(base) &&
2853                     cqr->status == DASD_CQR_FAILED) {
2854                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2855
2856                         /* restart request  */
2857                         cqr->status = DASD_CQR_FILLED;
2858                         cqr->retries = 255;
2859                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2860                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2861                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2862                                                flags);
2863                         goto restart;
2864                 }
2865
2866                 /* Process finished ERP request. */
2867                 if (cqr->refers) {
2868                         __dasd_process_erp(base, cqr);
2869                         goto restart;
2870                 }
2871
2872                 /* Rechain finished requests to final queue */
2873                 cqr->endclk = get_tod_clock();
2874                 list_move_tail(&cqr->blocklist, final_queue);
2875         }
2876 }
2877
2878 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2879 {
2880         dasd_schedule_block_bh(cqr->block);
2881 }
2882
2883 static void __dasd_block_start_head(struct dasd_block *block)
2884 {
2885         struct dasd_ccw_req *cqr;
2886
2887         if (list_empty(&block->ccw_queue))
2888                 return;
2889         /* We allways begin with the first requests on the queue, as some
2890          * of previously started requests have to be enqueued on a
2891          * dasd_device again for error recovery.
2892          */
2893         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2894                 if (cqr->status != DASD_CQR_FILLED)
2895                         continue;
2896                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2897                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2898                         cqr->status = DASD_CQR_FAILED;
2899                         cqr->intrc = -EPERM;
2900                         dasd_schedule_block_bh(block);
2901                         continue;
2902                 }
2903                 /* Non-temporary stop condition will trigger fail fast */
2904                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2905                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2906                     (!dasd_eer_enabled(block->base))) {
2907                         cqr->status = DASD_CQR_FAILED;
2908                         cqr->intrc = -ENOLINK;
2909                         dasd_schedule_block_bh(block);
2910                         continue;
2911                 }
2912                 /* Don't try to start requests if device is stopped */
2913                 if (block->base->stopped)
2914                         return;
2915
2916                 /* just a fail safe check, should not happen */
2917                 if (!cqr->startdev)
2918                         cqr->startdev = block->base;
2919
2920                 /* make sure that the requests we submit find their way back */
2921                 cqr->callback = dasd_return_cqr_cb;
2922
2923                 dasd_add_request_tail(cqr);
2924         }
2925 }
2926
2927 /*
2928  * Central dasd_block layer routine. Takes requests from the generic
2929  * block layer request queue, creates ccw requests, enqueues them on
2930  * a dasd_device and processes ccw requests that have been returned.
2931  */
2932 static void dasd_block_tasklet(unsigned long data)
2933 {
2934         struct dasd_block *block = (struct dasd_block *) data;
2935         struct list_head final_queue;
2936         struct list_head *l, *n;
2937         struct dasd_ccw_req *cqr;
2938         struct dasd_queue *dq;
2939
2940         atomic_set(&block->tasklet_scheduled, 0);
2941         INIT_LIST_HEAD(&final_queue);
2942         spin_lock_irq(&block->queue_lock);
2943         /* Finish off requests on ccw queue */
2944         __dasd_process_block_ccw_queue(block, &final_queue);
2945         spin_unlock_irq(&block->queue_lock);
2946
2947         /* Now call the callback function of requests with final status */
2948         list_for_each_safe(l, n, &final_queue) {
2949                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2950                 dq = cqr->dq;
2951                 spin_lock_irq(&dq->lock);
2952                 list_del_init(&cqr->blocklist);
2953                 __dasd_cleanup_cqr(cqr);
2954                 spin_unlock_irq(&dq->lock);
2955         }
2956
2957         spin_lock_irq(&block->queue_lock);
2958         /* Now check if the head of the ccw queue needs to be started. */
2959         __dasd_block_start_head(block);
2960         spin_unlock_irq(&block->queue_lock);
2961
2962         if (waitqueue_active(&shutdown_waitq))
2963                 wake_up(&shutdown_waitq);
2964         dasd_put_device(block->base);
2965 }
2966
2967 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2968 {
2969         wake_up(&dasd_flush_wq);
2970 }
2971
2972 /*
2973  * Requeue a request back to the block request queue
2974  * only works for block requests
2975  */
2976 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2977 {
2978         struct dasd_block *block = cqr->block;
2979         struct request *req;
2980
2981         if (!block)
2982                 return -EINVAL;
2983         /*
2984          * If the request is an ERP request there is nothing to requeue.
2985          * This will be done with the remaining original request.
2986          */
2987         if (cqr->refers)
2988                 return 0;
2989         spin_lock_irq(&cqr->dq->lock);
2990         req = (struct request *) cqr->callback_data;
2991         blk_mq_requeue_request(req, false);
2992         spin_unlock_irq(&cqr->dq->lock);
2993
2994         return 0;
2995 }
2996
2997 /*
2998  * Go through all request on the dasd_block request queue, cancel them
2999  * on the respective dasd_device, and return them to the generic
3000  * block layer.
3001  */
3002 static int dasd_flush_block_queue(struct dasd_block *block)
3003 {
3004         struct dasd_ccw_req *cqr, *n;
3005         int rc, i;
3006         struct list_head flush_queue;
3007         unsigned long flags;
3008
3009         INIT_LIST_HEAD(&flush_queue);
3010         spin_lock_bh(&block->queue_lock);
3011         rc = 0;
3012 restart:
3013         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
3014                 /* if this request currently owned by a dasd_device cancel it */
3015                 if (cqr->status >= DASD_CQR_QUEUED)
3016                         rc = dasd_cancel_req(cqr);
3017                 if (rc < 0)
3018                         break;
3019                 /* Rechain request (including erp chain) so it won't be
3020                  * touched by the dasd_block_tasklet anymore.
3021                  * Replace the callback so we notice when the request
3022                  * is returned from the dasd_device layer.
3023                  */
3024                 cqr->callback = _dasd_wake_block_flush_cb;
3025                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
3026                         list_move_tail(&cqr->blocklist, &flush_queue);
3027                 if (i > 1)
3028                         /* moved more than one request - need to restart */
3029                         goto restart;
3030         }
3031         spin_unlock_bh(&block->queue_lock);
3032         /* Now call the callback function of flushed requests */
3033 restart_cb:
3034         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3035                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3036                 /* Process finished ERP request. */
3037                 if (cqr->refers) {
3038                         spin_lock_bh(&block->queue_lock);
3039                         __dasd_process_erp(block->base, cqr);
3040                         spin_unlock_bh(&block->queue_lock);
3041                         /* restart list_for_xx loop since dasd_process_erp
3042                          * might remove multiple elements */
3043                         goto restart_cb;
3044                 }
3045                 /* call the callback function */
3046                 spin_lock_irqsave(&cqr->dq->lock, flags);
3047                 cqr->endclk = get_tod_clock();
3048                 list_del_init(&cqr->blocklist);
3049                 __dasd_cleanup_cqr(cqr);
3050                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3051         }
3052         return rc;
3053 }
3054
3055 /*
3056  * Schedules a call to dasd_tasklet over the device tasklet.
3057  */
3058 void dasd_schedule_block_bh(struct dasd_block *block)
3059 {
3060         /* Protect against rescheduling. */
3061         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3062                 return;
3063         /* life cycle of block is bound to it's base device */
3064         dasd_get_device(block->base);
3065         tasklet_hi_schedule(&block->tasklet);
3066 }
3067 EXPORT_SYMBOL(dasd_schedule_block_bh);
3068
3069
3070 /*
3071  * SECTION: external block device operations
3072  * (request queue handling, open, release, etc.)
3073  */
3074
3075 /*
3076  * Dasd request queue function. Called from ll_rw_blk.c
3077  */
3078 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3079                                     const struct blk_mq_queue_data *qd)
3080 {
3081         struct dasd_block *block = hctx->queue->queuedata;
3082         struct dasd_queue *dq = hctx->driver_data;
3083         struct request *req = qd->rq;
3084         struct dasd_device *basedev;
3085         struct dasd_ccw_req *cqr;
3086         blk_status_t rc = BLK_STS_OK;
3087
3088         basedev = block->base;
3089         spin_lock_irq(&dq->lock);
3090         if (basedev->state < DASD_STATE_READY) {
3091                 DBF_DEV_EVENT(DBF_ERR, basedev,
3092                               "device not ready for request %p", req);
3093                 rc = BLK_STS_IOERR;
3094                 goto out;
3095         }
3096
3097         /*
3098          * if device is stopped do not fetch new requests
3099          * except failfast is active which will let requests fail
3100          * immediately in __dasd_block_start_head()
3101          */
3102         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3103                 DBF_DEV_EVENT(DBF_ERR, basedev,
3104                               "device stopped request %p", req);
3105                 rc = BLK_STS_RESOURCE;
3106                 goto out;
3107         }
3108
3109         if (basedev->features & DASD_FEATURE_READONLY &&
3110             rq_data_dir(req) == WRITE) {
3111                 DBF_DEV_EVENT(DBF_ERR, basedev,
3112                               "Rejecting write request %p", req);
3113                 rc = BLK_STS_IOERR;
3114                 goto out;
3115         }
3116
3117         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3118             (basedev->features & DASD_FEATURE_FAILFAST ||
3119              blk_noretry_request(req))) {
3120                 DBF_DEV_EVENT(DBF_ERR, basedev,
3121                               "Rejecting failfast request %p", req);
3122                 rc = BLK_STS_IOERR;
3123                 goto out;
3124         }
3125
3126         cqr = basedev->discipline->build_cp(basedev, block, req);
3127         if (IS_ERR(cqr)) {
3128                 if (PTR_ERR(cqr) == -EBUSY ||
3129                     PTR_ERR(cqr) == -ENOMEM ||
3130                     PTR_ERR(cqr) == -EAGAIN) {
3131                         rc = BLK_STS_RESOURCE;
3132                         goto out;
3133                 }
3134                 DBF_DEV_EVENT(DBF_ERR, basedev,
3135                               "CCW creation failed (rc=%ld) on request %p",
3136                               PTR_ERR(cqr), req);
3137                 rc = BLK_STS_IOERR;
3138                 goto out;
3139         }
3140         /*
3141          *  Note: callback is set to dasd_return_cqr_cb in
3142          * __dasd_block_start_head to cover erp requests as well
3143          */
3144         cqr->callback_data = req;
3145         cqr->status = DASD_CQR_FILLED;
3146         cqr->dq = dq;
3147
3148         blk_mq_start_request(req);
3149         spin_lock(&block->queue_lock);
3150         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3151         INIT_LIST_HEAD(&cqr->devlist);
3152         dasd_profile_start(block, cqr, req);
3153         dasd_schedule_block_bh(block);
3154         spin_unlock(&block->queue_lock);
3155
3156 out:
3157         spin_unlock_irq(&dq->lock);
3158         return rc;
3159 }
3160
3161 /*
3162  * Block timeout callback, called from the block layer
3163  *
3164  * Return values:
3165  * BLK_EH_RESET_TIMER if the request should be left running
3166  * BLK_EH_DONE if the request is handled or terminated
3167  *                    by the driver.
3168  */
3169 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3170 {
3171         struct dasd_block *block = req->q->queuedata;
3172         struct dasd_device *device;
3173         struct dasd_ccw_req *cqr;
3174         unsigned long flags;
3175         int rc = 0;
3176
3177         cqr = blk_mq_rq_to_pdu(req);
3178         if (!cqr)
3179                 return BLK_EH_DONE;
3180
3181         spin_lock_irqsave(&cqr->dq->lock, flags);
3182         device = cqr->startdev ? cqr->startdev : block->base;
3183         if (!device->blk_timeout) {
3184                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3185                 return BLK_EH_RESET_TIMER;
3186         }
3187         DBF_DEV_EVENT(DBF_WARNING, device,
3188                       " dasd_times_out cqr %p status %x",
3189                       cqr, cqr->status);
3190
3191         spin_lock(&block->queue_lock);
3192         spin_lock(get_ccwdev_lock(device->cdev));
3193         cqr->retries = -1;
3194         cqr->intrc = -ETIMEDOUT;
3195         if (cqr->status >= DASD_CQR_QUEUED) {
3196                 rc = __dasd_cancel_req(cqr);
3197         } else if (cqr->status == DASD_CQR_FILLED ||
3198                    cqr->status == DASD_CQR_NEED_ERP) {
3199                 cqr->status = DASD_CQR_TERMINATED;
3200         } else if (cqr->status == DASD_CQR_IN_ERP) {
3201                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3202
3203                 list_for_each_entry_safe(searchcqr, nextcqr,
3204                                          &block->ccw_queue, blocklist) {
3205                         tmpcqr = searchcqr;
3206                         while (tmpcqr->refers)
3207                                 tmpcqr = tmpcqr->refers;
3208                         if (tmpcqr != cqr)
3209                                 continue;
3210                         /* searchcqr is an ERP request for cqr */
3211                         searchcqr->retries = -1;
3212                         searchcqr->intrc = -ETIMEDOUT;
3213                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3214                                 rc = __dasd_cancel_req(searchcqr);
3215                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3216                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3217                                 searchcqr->status = DASD_CQR_TERMINATED;
3218                                 rc = 0;
3219                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3220                                 /*
3221                                  * Shouldn't happen; most recent ERP
3222                                  * request is at the front of queue
3223                                  */
3224                                 continue;
3225                         }
3226                         break;
3227                 }
3228         }
3229         spin_unlock(get_ccwdev_lock(device->cdev));
3230         dasd_schedule_block_bh(block);
3231         spin_unlock(&block->queue_lock);
3232         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3233
3234         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3235 }
3236
3237 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3238                           unsigned int idx)
3239 {
3240         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3241
3242         if (!dq)
3243                 return -ENOMEM;
3244
3245         spin_lock_init(&dq->lock);
3246         hctx->driver_data = dq;
3247
3248         return 0;
3249 }
3250
3251 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3252 {
3253         kfree(hctx->driver_data);
3254         hctx->driver_data = NULL;
3255 }
3256
3257 static void dasd_request_done(struct request *req)
3258 {
3259         blk_mq_end_request(req, 0);
3260         blk_mq_run_hw_queues(req->q, true);
3261 }
3262
3263 static struct blk_mq_ops dasd_mq_ops = {
3264         .queue_rq = do_dasd_request,
3265         .complete = dasd_request_done,
3266         .timeout = dasd_times_out,
3267         .init_hctx = dasd_init_hctx,
3268         .exit_hctx = dasd_exit_hctx,
3269 };
3270
3271 /*
3272  * Allocate and initialize request queue and default I/O scheduler.
3273  */
3274 static int dasd_alloc_queue(struct dasd_block *block)
3275 {
3276         int rc;
3277
3278         block->tag_set.ops = &dasd_mq_ops;
3279         block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3280         block->tag_set.nr_hw_queues = nr_hw_queues;
3281         block->tag_set.queue_depth = queue_depth;
3282         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3283         block->tag_set.numa_node = NUMA_NO_NODE;
3284
3285         rc = blk_mq_alloc_tag_set(&block->tag_set);
3286         if (rc)
3287                 return rc;
3288
3289         block->request_queue = blk_mq_init_queue(&block->tag_set);
3290         if (IS_ERR(block->request_queue))
3291                 return PTR_ERR(block->request_queue);
3292
3293         block->request_queue->queuedata = block;
3294
3295         return 0;
3296 }
3297
3298 /*
3299  * Deactivate and free request queue.
3300  */
3301 static void dasd_free_queue(struct dasd_block *block)
3302 {
3303         if (block->request_queue) {
3304                 blk_cleanup_queue(block->request_queue);
3305                 blk_mq_free_tag_set(&block->tag_set);
3306                 block->request_queue = NULL;
3307         }
3308 }
3309
3310 static int dasd_open(struct block_device *bdev, fmode_t mode)
3311 {
3312         struct dasd_device *base;
3313         int rc;
3314
3315         base = dasd_device_from_gendisk(bdev->bd_disk);
3316         if (!base)
3317                 return -ENODEV;
3318
3319         atomic_inc(&base->block->open_count);
3320         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3321                 rc = -ENODEV;
3322                 goto unlock;
3323         }
3324
3325         if (!try_module_get(base->discipline->owner)) {
3326                 rc = -EINVAL;
3327                 goto unlock;
3328         }
3329
3330         if (dasd_probeonly) {
3331                 dev_info(&base->cdev->dev,
3332                          "Accessing the DASD failed because it is in "
3333                          "probeonly mode\n");
3334                 rc = -EPERM;
3335                 goto out;
3336         }
3337
3338         if (base->state <= DASD_STATE_BASIC) {
3339                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3340                               " Cannot open unrecognized device");
3341                 rc = -ENODEV;
3342                 goto out;
3343         }
3344
3345         if ((mode & FMODE_WRITE) &&
3346             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3347              (base->features & DASD_FEATURE_READONLY))) {
3348                 rc = -EROFS;
3349                 goto out;
3350         }
3351
3352         dasd_put_device(base);
3353         return 0;
3354
3355 out:
3356         module_put(base->discipline->owner);
3357 unlock:
3358         atomic_dec(&base->block->open_count);
3359         dasd_put_device(base);
3360         return rc;
3361 }
3362
3363 static void dasd_release(struct gendisk *disk, fmode_t mode)
3364 {
3365         struct dasd_device *base = dasd_device_from_gendisk(disk);
3366         if (base) {
3367                 atomic_dec(&base->block->open_count);
3368                 module_put(base->discipline->owner);
3369                 dasd_put_device(base);
3370         }
3371 }
3372
3373 /*
3374  * Return disk geometry.
3375  */
3376 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3377 {
3378         struct dasd_device *base;
3379
3380         base = dasd_device_from_gendisk(bdev->bd_disk);
3381         if (!base)
3382                 return -ENODEV;
3383
3384         if (!base->discipline ||
3385             !base->discipline->fill_geometry) {
3386                 dasd_put_device(base);
3387                 return -EINVAL;
3388         }
3389         base->discipline->fill_geometry(base->block, geo);
3390         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3391         dasd_put_device(base);
3392         return 0;
3393 }
3394
3395 const struct block_device_operations
3396 dasd_device_operations = {
3397         .owner          = THIS_MODULE,
3398         .open           = dasd_open,
3399         .release        = dasd_release,
3400         .ioctl          = dasd_ioctl,
3401         .compat_ioctl   = dasd_ioctl,
3402         .getgeo         = dasd_getgeo,
3403 };
3404
3405 /*******************************************************************************
3406  * end of block device operations
3407  */
3408
3409 static void
3410 dasd_exit(void)
3411 {
3412 #ifdef CONFIG_PROC_FS
3413         dasd_proc_exit();
3414 #endif
3415         dasd_eer_exit();
3416         kmem_cache_destroy(dasd_page_cache);
3417         dasd_page_cache = NULL;
3418         dasd_gendisk_exit();
3419         dasd_devmap_exit();
3420         if (dasd_debug_area != NULL) {
3421                 debug_unregister(dasd_debug_area);
3422                 dasd_debug_area = NULL;
3423         }
3424         dasd_statistics_removeroot();
3425 }
3426
3427 /*
3428  * SECTION: common functions for ccw_driver use
3429  */
3430
3431 /*
3432  * Is the device read-only?
3433  * Note that this function does not report the setting of the
3434  * readonly device attribute, but how it is configured in z/VM.
3435  */
3436 int dasd_device_is_ro(struct dasd_device *device)
3437 {
3438         struct ccw_dev_id dev_id;
3439         struct diag210 diag_data;
3440         int rc;
3441
3442         if (!MACHINE_IS_VM)
3443                 return 0;
3444         ccw_device_get_id(device->cdev, &dev_id);
3445         memset(&diag_data, 0, sizeof(diag_data));
3446         diag_data.vrdcdvno = dev_id.devno;
3447         diag_data.vrdclen = sizeof(diag_data);
3448         rc = diag210(&diag_data);
3449         if (rc == 0 || rc == 2) {
3450                 return diag_data.vrdcvfla & 0x80;
3451         } else {
3452                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3453                           dev_id.devno, rc);
3454                 return 0;
3455         }
3456 }
3457 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3458
3459 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3460 {
3461         struct ccw_device *cdev = data;
3462         int ret;
3463
3464         ret = ccw_device_set_online(cdev);
3465         if (ret)
3466                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3467                         dev_name(&cdev->dev), ret);
3468 }
3469
3470 /*
3471  * Initial attempt at a probe function. this can be simplified once
3472  * the other detection code is gone.
3473  */
3474 int dasd_generic_probe(struct ccw_device *cdev,
3475                        struct dasd_discipline *discipline)
3476 {
3477         int ret;
3478
3479         ret = dasd_add_sysfs_files(cdev);
3480         if (ret) {
3481                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3482                                 "dasd_generic_probe: could not add "
3483                                 "sysfs entries");
3484                 return ret;
3485         }
3486         cdev->handler = &dasd_int_handler;
3487
3488         /*
3489          * Automatically online either all dasd devices (dasd_autodetect)
3490          * or all devices specified with dasd= parameters during
3491          * initial probe.
3492          */
3493         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3494             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3495                 async_schedule(dasd_generic_auto_online, cdev);
3496         return 0;
3497 }
3498 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3499
3500 void dasd_generic_free_discipline(struct dasd_device *device)
3501 {
3502         /* Forget the discipline information. */
3503         if (device->discipline) {
3504                 if (device->discipline->uncheck_device)
3505                         device->discipline->uncheck_device(device);
3506                 module_put(device->discipline->owner);
3507                 device->discipline = NULL;
3508         }
3509         if (device->base_discipline) {
3510                 module_put(device->base_discipline->owner);
3511                 device->base_discipline = NULL;
3512         }
3513 }
3514 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3515
3516 /*
3517  * This will one day be called from a global not_oper handler.
3518  * It is also used by driver_unregister during module unload.
3519  */
3520 void dasd_generic_remove(struct ccw_device *cdev)
3521 {
3522         struct dasd_device *device;
3523         struct dasd_block *block;
3524
3525         cdev->handler = NULL;
3526
3527         device = dasd_device_from_cdev(cdev);
3528         if (IS_ERR(device)) {
3529                 dasd_remove_sysfs_files(cdev);
3530                 return;
3531         }
3532         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3533             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3534                 /* Already doing offline processing */
3535                 dasd_put_device(device);
3536                 dasd_remove_sysfs_files(cdev);
3537                 return;
3538         }
3539         /*
3540          * This device is removed unconditionally. Set offline
3541          * flag to prevent dasd_open from opening it while it is
3542          * no quite down yet.
3543          */
3544         dasd_set_target_state(device, DASD_STATE_NEW);
3545         /* dasd_delete_device destroys the device reference. */
3546         block = device->block;
3547         dasd_delete_device(device);
3548         /*
3549          * life cycle of block is bound to device, so delete it after
3550          * device was safely removed
3551          */
3552         if (block)
3553                 dasd_free_block(block);
3554
3555         dasd_remove_sysfs_files(cdev);
3556 }
3557 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3558
3559 /*
3560  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3561  * the device is detected for the first time and is supposed to be used
3562  * or the user has started activation through sysfs.
3563  */
3564 int dasd_generic_set_online(struct ccw_device *cdev,
3565                             struct dasd_discipline *base_discipline)
3566 {
3567         struct dasd_discipline *discipline;
3568         struct dasd_device *device;
3569         int rc;
3570
3571         /* first online clears initial online feature flag */
3572         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3573         device = dasd_create_device(cdev);
3574         if (IS_ERR(device))
3575                 return PTR_ERR(device);
3576
3577         discipline = base_discipline;
3578         if (device->features & DASD_FEATURE_USEDIAG) {
3579                 if (!dasd_diag_discipline_pointer) {
3580                         /* Try to load the required module. */
3581                         rc = request_module(DASD_DIAG_MOD);
3582                         if (rc) {
3583                                 pr_warn("%s Setting the DASD online failed "
3584                                         "because the required module %s "
3585                                         "could not be loaded (rc=%d)\n",
3586                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3587                                         rc);
3588                                 dasd_delete_device(device);
3589                                 return -ENODEV;
3590                         }
3591                 }
3592                 /* Module init could have failed, so check again here after
3593                  * request_module(). */
3594                 if (!dasd_diag_discipline_pointer) {
3595                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3596                                 dev_name(&cdev->dev));
3597                         dasd_delete_device(device);
3598                         return -ENODEV;
3599                 }
3600                 discipline = dasd_diag_discipline_pointer;
3601         }
3602         if (!try_module_get(base_discipline->owner)) {
3603                 dasd_delete_device(device);
3604                 return -EINVAL;
3605         }
3606         if (!try_module_get(discipline->owner)) {
3607                 module_put(base_discipline->owner);
3608                 dasd_delete_device(device);
3609                 return -EINVAL;
3610         }
3611         device->base_discipline = base_discipline;
3612         device->discipline = discipline;
3613
3614         /* check_device will allocate block device if necessary */
3615         rc = discipline->check_device(device);
3616         if (rc) {
3617                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3618                         dev_name(&cdev->dev), discipline->name, rc);
3619                 module_put(discipline->owner);
3620                 module_put(base_discipline->owner);
3621                 dasd_delete_device(device);
3622                 return rc;
3623         }
3624
3625         dasd_set_target_state(device, DASD_STATE_ONLINE);
3626         if (device->state <= DASD_STATE_KNOWN) {
3627                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3628                         dev_name(&cdev->dev));
3629                 rc = -ENODEV;
3630                 dasd_set_target_state(device, DASD_STATE_NEW);
3631                 if (device->block)
3632                         dasd_free_block(device->block);
3633                 dasd_delete_device(device);
3634         } else
3635                 pr_debug("dasd_generic device %s found\n",
3636                                 dev_name(&cdev->dev));
3637
3638         wait_event(dasd_init_waitq, _wait_for_device(device));
3639
3640         dasd_put_device(device);
3641         return rc;
3642 }
3643 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3644
3645 int dasd_generic_set_offline(struct ccw_device *cdev)
3646 {
3647         struct dasd_device *device;
3648         struct dasd_block *block;
3649         int max_count, open_count, rc;
3650         unsigned long flags;
3651
3652         rc = 0;
3653         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3654         device = dasd_device_from_cdev_locked(cdev);
3655         if (IS_ERR(device)) {
3656                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3657                 return PTR_ERR(device);
3658         }
3659
3660         /*
3661          * We must make sure that this device is currently not in use.
3662          * The open_count is increased for every opener, that includes
3663          * the blkdev_get in dasd_scan_partitions. We are only interested
3664          * in the other openers.
3665          */
3666         if (device->block) {
3667                 max_count = device->block->bdev ? 0 : -1;
3668                 open_count = atomic_read(&device->block->open_count);
3669                 if (open_count > max_count) {
3670                         if (open_count > 0)
3671                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3672                                         dev_name(&cdev->dev), open_count);
3673                         else
3674                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3675                                         dev_name(&cdev->dev));
3676                         rc = -EBUSY;
3677                         goto out_err;
3678                 }
3679         }
3680
3681         /*
3682          * Test if the offline processing is already running and exit if so.
3683          * If a safe offline is being processed this could only be a normal
3684          * offline that should be able to overtake the safe offline and
3685          * cancel any I/O we do not want to wait for any longer
3686          */
3687         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3688                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3689                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3690                                   &device->flags);
3691                 } else {
3692                         rc = -EBUSY;
3693                         goto out_err;
3694                 }
3695         }
3696         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3697
3698         /*
3699          * if safe_offline is called set safe_offline_running flag and
3700          * clear safe_offline so that a call to normal offline
3701          * can overrun safe_offline processing
3702          */
3703         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3704             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3705                 /* need to unlock here to wait for outstanding I/O */
3706                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3707                 /*
3708                  * If we want to set the device safe offline all IO operations
3709                  * should be finished before continuing the offline process
3710                  * so sync bdev first and then wait for our queues to become
3711                  * empty
3712                  */
3713                 if (device->block) {
3714                         rc = fsync_bdev(device->block->bdev);
3715                         if (rc != 0)
3716                                 goto interrupted;
3717                 }
3718                 dasd_schedule_device_bh(device);
3719                 rc = wait_event_interruptible(shutdown_waitq,
3720                                               _wait_for_empty_queues(device));
3721                 if (rc != 0)
3722                         goto interrupted;
3723
3724                 /*
3725                  * check if a normal offline process overtook the offline
3726                  * processing in this case simply do nothing beside returning
3727                  * that we got interrupted
3728                  * otherwise mark safe offline as not running any longer and
3729                  * continue with normal offline
3730                  */
3731                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3732                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3733                         rc = -ERESTARTSYS;
3734                         goto out_err;
3735                 }
3736                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3737         }
3738         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3739
3740         dasd_set_target_state(device, DASD_STATE_NEW);
3741         /* dasd_delete_device destroys the device reference. */
3742         block = device->block;
3743         dasd_delete_device(device);
3744         /*
3745          * life cycle of block is bound to device, so delete it after
3746          * device was safely removed
3747          */
3748         if (block)
3749                 dasd_free_block(block);
3750
3751         return 0;
3752
3753 interrupted:
3754         /* interrupted by signal */
3755         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3756         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3757         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3758 out_err:
3759         dasd_put_device(device);
3760         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3761         return rc;
3762 }
3763 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3764
3765 int dasd_generic_last_path_gone(struct dasd_device *device)
3766 {
3767         struct dasd_ccw_req *cqr;
3768
3769         dev_warn(&device->cdev->dev, "No operational channel path is left "
3770                  "for the device\n");
3771         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3772         /* First of all call extended error reporting. */
3773         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3774
3775         if (device->state < DASD_STATE_BASIC)
3776                 return 0;
3777         /* Device is active. We want to keep it. */
3778         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3779                 if ((cqr->status == DASD_CQR_IN_IO) ||
3780                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3781                         cqr->status = DASD_CQR_QUEUED;
3782                         cqr->retries++;
3783                 }
3784         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3785         dasd_device_clear_timer(device);
3786         dasd_schedule_device_bh(device);
3787         return 1;
3788 }
3789 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3790
3791 int dasd_generic_path_operational(struct dasd_device *device)
3792 {
3793         dev_info(&device->cdev->dev, "A channel path to the device has become "
3794                  "operational\n");
3795         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3796         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3797         if (device->stopped & DASD_UNRESUMED_PM) {
3798                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3799                 dasd_restore_device(device);
3800                 return 1;
3801         }
3802         dasd_schedule_device_bh(device);
3803         if (device->block) {
3804                 dasd_schedule_block_bh(device->block);
3805                 if (device->block->request_queue)
3806                         blk_mq_run_hw_queues(device->block->request_queue,
3807                                              true);
3808                 }
3809
3810         if (!device->stopped)
3811                 wake_up(&generic_waitq);
3812
3813         return 1;
3814 }
3815 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3816
3817 int dasd_generic_notify(struct ccw_device *cdev, int event)
3818 {
3819         struct dasd_device *device;
3820         int ret;
3821
3822         device = dasd_device_from_cdev_locked(cdev);
3823         if (IS_ERR(device))
3824                 return 0;
3825         ret = 0;
3826         switch (event) {
3827         case CIO_GONE:
3828         case CIO_BOXED:
3829         case CIO_NO_PATH:
3830                 dasd_path_no_path(device);
3831                 ret = dasd_generic_last_path_gone(device);
3832                 break;
3833         case CIO_OPER:
3834                 ret = 1;
3835                 if (dasd_path_get_opm(device))
3836                         ret = dasd_generic_path_operational(device);
3837                 break;
3838         }
3839         dasd_put_device(device);
3840         return ret;
3841 }
3842 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3843
3844 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3845 {
3846         struct dasd_device *device;
3847         int chp, oldopm, hpfpm, ifccpm;
3848
3849         device = dasd_device_from_cdev_locked(cdev);
3850         if (IS_ERR(device))
3851                 return;
3852
3853         oldopm = dasd_path_get_opm(device);
3854         for (chp = 0; chp < 8; chp++) {
3855                 if (path_event[chp] & PE_PATH_GONE) {
3856                         dasd_path_notoper(device, chp);
3857                 }
3858                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3859                         dasd_path_available(device, chp);
3860                         dasd_schedule_device_bh(device);
3861                 }
3862                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3863                         if (!dasd_path_is_operational(device, chp) &&
3864                             !dasd_path_need_verify(device, chp)) {
3865                                 /*
3866                                  * we can not establish a pathgroup on an
3867                                  * unavailable path, so trigger a path
3868                                  * verification first
3869                                  */
3870                         dasd_path_available(device, chp);
3871                         dasd_schedule_device_bh(device);
3872                         }
3873                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3874                                       "Pathgroup re-established\n");
3875                         if (device->discipline->kick_validate)
3876                                 device->discipline->kick_validate(device);
3877                 }
3878         }
3879         hpfpm = dasd_path_get_hpfpm(device);
3880         ifccpm = dasd_path_get_ifccpm(device);
3881         if (!dasd_path_get_opm(device) && hpfpm) {
3882                 /*
3883                  * device has no operational paths but at least one path is
3884                  * disabled due to HPF errors
3885                  * disable HPF at all and use the path(s) again
3886                  */
3887                 if (device->discipline->disable_hpf)
3888                         device->discipline->disable_hpf(device);
3889                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3890                 dasd_path_set_tbvpm(device, hpfpm);
3891                 dasd_schedule_device_bh(device);
3892                 dasd_schedule_requeue(device);
3893         } else if (!dasd_path_get_opm(device) && ifccpm) {
3894                 /*
3895                  * device has no operational paths but at least one path is
3896                  * disabled due to IFCC errors
3897                  * trigger path verification on paths with IFCC errors
3898                  */
3899                 dasd_path_set_tbvpm(device, ifccpm);
3900                 dasd_schedule_device_bh(device);
3901         }
3902         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3903                 dev_warn(&device->cdev->dev,
3904                          "No verified channel paths remain for the device\n");
3905                 DBF_DEV_EVENT(DBF_WARNING, device,
3906                               "%s", "last verified path gone");
3907                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3908                 dasd_device_set_stop_bits(device,
3909                                           DASD_STOPPED_DC_WAIT);
3910         }
3911         dasd_put_device(device);
3912 }
3913 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3914
3915 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3916 {
3917         if (!dasd_path_get_opm(device) && lpm) {
3918                 dasd_path_set_opm(device, lpm);
3919                 dasd_generic_path_operational(device);
3920         } else
3921                 dasd_path_add_opm(device, lpm);
3922         return 0;
3923 }
3924 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3925
3926 void dasd_generic_space_exhaust(struct dasd_device *device,
3927                                 struct dasd_ccw_req *cqr)
3928 {
3929         dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3930
3931         if (device->state < DASD_STATE_BASIC)
3932                 return;
3933
3934         if (cqr->status == DASD_CQR_IN_IO ||
3935             cqr->status == DASD_CQR_CLEAR_PENDING) {
3936                 cqr->status = DASD_CQR_QUEUED;
3937                 cqr->retries++;
3938         }
3939         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3940         dasd_device_clear_timer(device);
3941         dasd_schedule_device_bh(device);
3942 }
3943 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3944
3945 void dasd_generic_space_avail(struct dasd_device *device)
3946 {
3947         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3948         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3949
3950         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3951         dasd_schedule_device_bh(device);
3952
3953         if (device->block) {
3954                 dasd_schedule_block_bh(device->block);
3955                 if (device->block->request_queue)
3956                         blk_mq_run_hw_queues(device->block->request_queue, true);
3957         }
3958         if (!device->stopped)
3959                 wake_up(&generic_waitq);
3960 }
3961 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3962
3963 /*
3964  * clear active requests and requeue them to block layer if possible
3965  */
3966 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3967 {
3968         struct list_head requeue_queue;
3969         struct dasd_ccw_req *cqr, *n;
3970         struct dasd_ccw_req *refers;
3971         int rc;
3972
3973         INIT_LIST_HEAD(&requeue_queue);
3974         spin_lock_irq(get_ccwdev_lock(device->cdev));
3975         rc = 0;
3976         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3977                 /* Check status and move request to flush_queue */
3978                 if (cqr->status == DASD_CQR_IN_IO) {
3979                         rc = device->discipline->term_IO(cqr);
3980                         if (rc) {
3981                                 /* unable to terminate requeust */
3982                                 dev_err(&device->cdev->dev,
3983                                         "Unable to terminate request %p "
3984                                         "on suspend\n", cqr);
3985                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3986                                 dasd_put_device(device);
3987                                 return rc;
3988                         }
3989                 }
3990                 list_move_tail(&cqr->devlist, &requeue_queue);
3991         }
3992         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3993
3994         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3995                 wait_event(dasd_flush_wq,
3996                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3997
3998                 /*
3999                  * requeue requests to blocklayer will only work
4000                  * for block device requests
4001                  */
4002                 if (_dasd_requeue_request(cqr))
4003                         continue;
4004
4005                 /* remove requests from device and block queue */
4006                 list_del_init(&cqr->devlist);
4007                 while (cqr->refers != NULL) {
4008                         refers = cqr->refers;
4009                         /* remove the request from the block queue */
4010                         list_del(&cqr->blocklist);
4011                         /* free the finished erp request */
4012                         dasd_free_erp_request(cqr, cqr->memdev);
4013                         cqr = refers;
4014                 }
4015
4016                 /*
4017                  * _dasd_requeue_request already checked for a valid
4018                  * blockdevice, no need to check again
4019                  * all erp requests (cqr->refers) have a cqr->block
4020                  * pointer copy from the original cqr
4021                  */
4022                 list_del_init(&cqr->blocklist);
4023                 cqr->block->base->discipline->free_cp(
4024                         cqr, (struct request *) cqr->callback_data);
4025         }
4026
4027         /*
4028          * if requests remain then they are internal request
4029          * and go back to the device queue
4030          */
4031         if (!list_empty(&requeue_queue)) {
4032                 /* move freeze_queue to start of the ccw_queue */
4033                 spin_lock_irq(get_ccwdev_lock(device->cdev));
4034                 list_splice_tail(&requeue_queue, &device->ccw_queue);
4035                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
4036         }
4037         dasd_schedule_device_bh(device);
4038         return rc;
4039 }
4040
4041 static void do_requeue_requests(struct work_struct *work)
4042 {
4043         struct dasd_device *device = container_of(work, struct dasd_device,
4044                                                   requeue_requests);
4045         dasd_generic_requeue_all_requests(device);
4046         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
4047         if (device->block)
4048                 dasd_schedule_block_bh(device->block);
4049         dasd_put_device(device);
4050 }
4051
4052 void dasd_schedule_requeue(struct dasd_device *device)
4053 {
4054         dasd_get_device(device);
4055         /* queue call to dasd_reload_device to the kernel event daemon. */
4056         if (!schedule_work(&device->requeue_requests))
4057                 dasd_put_device(device);
4058 }
4059 EXPORT_SYMBOL(dasd_schedule_requeue);
4060
4061 int dasd_generic_pm_freeze(struct ccw_device *cdev)
4062 {
4063         struct dasd_device *device = dasd_device_from_cdev(cdev);
4064
4065         if (IS_ERR(device))
4066                 return PTR_ERR(device);
4067
4068         /* mark device as suspended */
4069         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
4070
4071         if (device->discipline->freeze)
4072                 device->discipline->freeze(device);
4073
4074         /* disallow new I/O  */
4075         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
4076
4077         return dasd_generic_requeue_all_requests(device);
4078 }
4079 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
4080
4081 int dasd_generic_restore_device(struct ccw_device *cdev)
4082 {
4083         struct dasd_device *device = dasd_device_from_cdev(cdev);
4084         int rc = 0;
4085
4086         if (IS_ERR(device))
4087                 return PTR_ERR(device);
4088
4089         /* allow new IO again */
4090         dasd_device_remove_stop_bits(device,
4091                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4092
4093         dasd_schedule_device_bh(device);
4094
4095         /*
4096          * call discipline restore function
4097          * if device is stopped do nothing e.g. for disconnected devices
4098          */
4099         if (device->discipline->restore && !(device->stopped))
4100                 rc = device->discipline->restore(device);
4101         if (rc || device->stopped)
4102                 /*
4103                  * if the resume failed for the DASD we put it in
4104                  * an UNRESUMED stop state
4105                  */
4106                 device->stopped |= DASD_UNRESUMED_PM;
4107
4108         if (device->block) {
4109                 dasd_schedule_block_bh(device->block);
4110                 if (device->block->request_queue)
4111                         blk_mq_run_hw_queues(device->block->request_queue,
4112                                              true);
4113         }
4114
4115         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4116         dasd_put_device(device);
4117         return 0;
4118 }
4119 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4120
4121 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4122                                                    int rdc_buffer_size,
4123                                                    int magic)
4124 {
4125         struct dasd_ccw_req *cqr;
4126         struct ccw1 *ccw;
4127
4128         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
4129                                    NULL);
4130
4131         if (IS_ERR(cqr)) {
4132                 /* internal error 13 - Allocating the RDC request failed*/
4133                 dev_err(&device->cdev->dev,
4134                          "An error occurred in the DASD device driver, "
4135                          "reason=%s\n", "13");
4136                 return cqr;
4137         }
4138
4139         ccw = cqr->cpaddr;
4140         ccw->cmd_code = CCW_CMD_RDC;
4141         ccw->cda = (__u32)(addr_t) cqr->data;
4142         ccw->flags = 0;
4143         ccw->count = rdc_buffer_size;
4144         cqr->startdev = device;
4145         cqr->memdev = device;
4146         cqr->expires = 10*HZ;
4147         cqr->retries = 256;
4148         cqr->buildclk = get_tod_clock();
4149         cqr->status = DASD_CQR_FILLED;
4150         return cqr;
4151 }
4152
4153
4154 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4155                                 void *rdc_buffer, int rdc_buffer_size)
4156 {
4157         int ret;
4158         struct dasd_ccw_req *cqr;
4159
4160         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4161         if (IS_ERR(cqr))
4162                 return PTR_ERR(cqr);
4163
4164         ret = dasd_sleep_on(cqr);
4165         if (ret == 0)
4166                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4167         dasd_sfree_request(cqr, cqr->memdev);
4168         return ret;
4169 }
4170 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4171
4172 /*
4173  *   In command mode and transport mode we need to look for sense
4174  *   data in different places. The sense data itself is allways
4175  *   an array of 32 bytes, so we can unify the sense data access
4176  *   for both modes.
4177  */
4178 char *dasd_get_sense(struct irb *irb)
4179 {
4180         struct tsb *tsb = NULL;
4181         char *sense = NULL;
4182
4183         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4184                 if (irb->scsw.tm.tcw)
4185                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4186                                           irb->scsw.tm.tcw);
4187                 if (tsb && tsb->length == 64 && tsb->flags)
4188                         switch (tsb->flags & 0x07) {
4189                         case 1: /* tsa_iostat */
4190                                 sense = tsb->tsa.iostat.sense;
4191                                 break;
4192                         case 2: /* tsa_ddpc */
4193                                 sense = tsb->tsa.ddpc.sense;
4194                                 break;
4195                         default:
4196                                 /* currently we don't use interrogate data */
4197                                 break;
4198                         }
4199         } else if (irb->esw.esw0.erw.cons) {
4200                 sense = irb->ecw;
4201         }
4202         return sense;
4203 }
4204 EXPORT_SYMBOL_GPL(dasd_get_sense);
4205
4206 void dasd_generic_shutdown(struct ccw_device *cdev)
4207 {
4208         struct dasd_device *device;
4209
4210         device = dasd_device_from_cdev(cdev);
4211         if (IS_ERR(device))
4212                 return;
4213
4214         if (device->block)
4215                 dasd_schedule_block_bh(device->block);
4216
4217         dasd_schedule_device_bh(device);
4218
4219         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4220 }
4221 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4222
4223 static int __init dasd_init(void)
4224 {
4225         int rc;
4226
4227         init_waitqueue_head(&dasd_init_waitq);
4228         init_waitqueue_head(&dasd_flush_wq);
4229         init_waitqueue_head(&generic_waitq);
4230         init_waitqueue_head(&shutdown_waitq);
4231
4232         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4233         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4234         if (dasd_debug_area == NULL) {
4235                 rc = -ENOMEM;
4236                 goto failed;
4237         }
4238         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4239         debug_set_level(dasd_debug_area, DBF_WARNING);
4240
4241         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4242
4243         dasd_diag_discipline_pointer = NULL;
4244
4245         dasd_statistics_createroot();
4246
4247         rc = dasd_devmap_init();
4248         if (rc)
4249                 goto failed;
4250         rc = dasd_gendisk_init();
4251         if (rc)
4252                 goto failed;
4253         rc = dasd_parse();
4254         if (rc)
4255                 goto failed;
4256         rc = dasd_eer_init();
4257         if (rc)
4258                 goto failed;
4259 #ifdef CONFIG_PROC_FS
4260         rc = dasd_proc_init();
4261         if (rc)
4262                 goto failed;
4263 #endif
4264
4265         return 0;
4266 failed:
4267         pr_info("The DASD device driver could not be initialized\n");
4268         dasd_exit();
4269         return rc;
4270 }
4271
4272 module_init(dasd_init);
4273 module_exit(dasd_exit);